FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Maeda, H Song, W DellaPenna, D AF Maeda, H Song, W DellaPenna, D TI Vitamin E functions in Arabidopsis leaves. SO PLANT AND CELL PHYSIOLOGY LA English DT Meeting Abstract CT 47th Annual Meeting of the Japanese-Society-of-Plant-Physiologists CY MAR 19-21, 2006 CL Univ Tsukuba, Tsukuba, JAPAN SP Japanese Soc Plant Physiologists HO Univ Tsukuba C1 Michigan State Univ, Dept Biochem & Mol Biol, E Lansing, MI 48824 USA. Michigan State Univ, DOE Plant Res Lab, E Lansing, MI 48824 USA. Michigan State Univ, Cell & Mol Biol Program, E Lansing, MI 48824 USA. Michigan State Univ, Genet Program, E Lansing, MI 48824 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0032-0781 J9 PLANT CELL PHYSIOL JI Plant Cell Physiol. PY 2006 VL 47 SU S BP S44 EP S44 PG 1 WC Plant Sciences; Cell Biology SC Plant Sciences; Cell Biology GA 027GC UT WOS:000236401400177 ER PT S AU Nieto, M Allain, JP Hassanein, A Titov, V Hendricks, M Gray, T Kaita, R Kugel, H Majeski, R Mansfield, D Spaleta, J Timberlake, J AF Nieto, M. Allain, J. P. Hassanein, A. Titov, V. Hendricks, M. Gray, T. Kaita, R. Kugel, H. Majeski, R. Mansfield, D. Spaleta, J. Timberlake, J. BE HerreraVelazquez, JJE TI Plasma-material interaction studies on lithium and lithiated substrates during compact tokamak operation SO PLASMA AND FUSION SCIENCE SE AIP Conference Proceedings LA English DT Proceedings Paper CT 16th IAEA Technical Meeting on Research Using Small Fusion Devices CY NOV 30-DEC 03, 2005 CL Mexico City, MEXICO SP IAEA, Natl Autonomous Univ Mexico, Mexican Phys Soc, Natl Council Sci & Technol, Latin Amer Phys Ctr, Autonomous Univ State Mexico DE plasma-facing components; lithium; compact tokamaks; thin films; surface characterization ID GRAPHITE; BOMBARDMENT; PERFORMANCE; EROSION; LIMITER; ALPS AB The role of lithium on the modification of recycling regimes in fusion reactors has renewed interest of previous lithium supershot experiments carried out in TFTR [1]. There is a need to understand the interaction between edge plasmas and lithiated plasma-facing components (PFCs), which have the potential of enabling fusion reactors to operate at low-recycling regimes. The Interaction of Materials with Particles and Components Testing (IMPACT) facility at Argonne National Laboratory is currently collaborating with Princeton Plasma Physics Laboratory (PPPL) to conduct lithiated surface studies for the National Spherical Tokamak Experiment (NSTX) and the Current Drive eXperiment - Upgrade (CDX-U). IMPACT has the necessary tools to perform experiments that diagnose the surface dynamics of lithium thin films on metallic and non-metallic substrates, and can be monitored with multiple in-situ techniques (LEISS, AES, QMS and XPS) capturing real-time surface dynamics. Therefore, these techniques are available during He+ and D+ irradiation. Surface sputtering measurements can be performed using a quartz crystal microbalance - dual crystal unit (QCM-DCU) with very high sensitivity. Initial results suggest that lithium intercalation into graphite occurs quite rapidly and only a fraction lithium can be kept on the surface. On metallic substrates this intercalation is absent. Additional results of Li/metal systems show lithium surface self-healing with temperature. It was also found that the presence of lithium seems to inhibit hydrocarbon formation during D+ bombardment of graphite. Experiments in CDX-U have tested the effect of both solid and liquid lithium PFCs on tokamak plasmas, and significant changes in tokamak operation are observed. These include a strong reduction in both recycling and impurity levels in the gas phase, lowered loop voltage during ohmic operation, and an increased electron temperature at the edge. C1 [Nieto, M.; Allain, J. P.; Hassanein, A.; Titov, V.; Hendricks, M.] Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. [Gray, T.; Kaita, R.; Kugel, H.; Majeski, R.; Mansfield, D.; Spaleta, J.; Timberlake, J.] Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Nieto, M (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. OI Nieto-Perez, Martin/0000-0001-6600-9786; Allain, Jean Paul/0000-0003-1348-262X NR 13 TC 1 Z9 1 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0375-8 J9 AIP CONF PROC PY 2006 VL 875 BP 78 EP + PG 2 WC Physics, Fluids & Plasmas; Physics, Multidisciplinary SC Physics GA BFS86 UT WOS:000244439700015 ER PT S AU Soboleva, TK Krasheninnikov, SI Pigarov, AY Rognlein, TD AF Soboleva, T. K. Krasheninnikov, S. I. Pigarov, A. Yu. Rognlein, T. D. BE HerreraVelazquez, JJE TI Investigation of dust particle transport in tokamak edge plasma by means of DUSTT code. SO PLASMA AND FUSION SCIENCE SE AIP Conference Proceedings LA English DT Proceedings Paper CT 11th Latin American Workshop on Plasma Physics CY DEC 05-09, 2006 CL Mexico City, MEXICO SP Natl Autonomous Univ Mexico, Autonomous Univ State Mexico, Mexican Phys Soc, Natl Council Sci & Technol, Latin Amer Phys Ctr, Int Atom Energy Agcy DE tokamak; scrape-off-layer; dust ID FUSION DEVICES AB The dust particles are unavoidably present in all fusion devises. Dust particles can provide important source of impurities in tokamak plasma. D-T fuel accumulation in dusty particles in future thermonuclear devises can present a potentially serious safety problem. We investigated dust particle transport dynamics in tokamaks using ne-My developed 3D code DUSTT and present the results obtained for ITER tokamak. C1 [Soboleva, T. K.] Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Mexico City, DF, Mexico. [Soboleva, T. K.] RRC Kurchatov Inst, Moscow, Russia. [Krasheninnikov, S. I.; Pigarov, A. Yu.] Univ Calif San Diego, San Diego, CA USA. [Rognlein, T. D.] Lawrence Livermore Natl Lab, Livermore, CA USA. RP Soboleva, TK (reprint author), Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Mexico City, DF, Mexico. FU U.S. Department of Energy by UCSD [DE-FG02-04ER54739, DE-FG02-02ER54680]; University California LLNL [W-7405-Eng-48]; Tatiana Soboleva [N-44324-F]; CONACyT [IN-I 155205] FX The work was performed under auspices of the U.S. Department of Energy by UCSD under grant,. Nos.DE-FG02-04ER54739 and DE-FG02-02ER54680 and by University California LLNL under contract No. W-7405-Eng-48.Tatiana Soboleva acknowledges support under grants N-44324-F of CONACyT and IN-I 155205 of DGAPA. UNAM, Mexico. NR 9 TC 0 Z9 0 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 978-0-7354-0375-8 J9 AIP CONF PROC PY 2006 VL 875 BP 381 EP + PG 2 WC Physics, Fluids & Plasmas; Physics, Multidisciplinary SC Physics GA BFS86 UT WOS:000244439700079 ER PT S AU Jusinski, LE Bahuguna, R Das, A Arya, K AF Jusinski, Leonard E. Bahuguna, Ramen Das, Amrita Arya, Karamjeet BE Tuan, V Lakowicz, JR Gryczynski, Z TI Surface Enhanced Raman Spectroscopy (SERS) from a molecule adsorbed on a nanoscale silver particle cluster in a holographic plate - art. no. 609901 SO Plasmonics in Biology and Medicine III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Plasmonics in Biology and Medicine III CY JAN 23-24, 2006 CL San Jose, CA DE enhanced Raman scattering; single molecule detection; nanoparticles; surface plasmon modes ID RHODAMINE 6G MOLECULES; SCATTERING; ELECTRODE; NANOPARTICLES; NANOCRYSTALS; SENSITIVITY; PYRIDINE; SPECTRA AB Surface enhanced Raman spectroscopy has become a viable technique for the detection of single molecules. This highly sensitive technique is due to the very large (up to 14 orders in magnitude) enhancement in the Raman cross section when the molecule is adsorbed on a metal nanoparticle cluster. We report here SERS (Surface Enhanced Raman Spectroscopy) experiments performed by adsorbing analyte molecules on nanoscale silver particle clusters within the gelatin layer of commercially available holographic plates which have been developed and fixed. The Ag particles range in size between 5-30 nanometers (nm). Sample preparation was performed by immersing the prepared holographic plate in an analyte solution for a few minutes. We report here the production of SERS signals from Rhodamine 6G (R6G) molecules of nanomolar concentration. These measurements demonstrate a fast, low cost, reproducible technique of producing SERS substrates in a matter of minutes compared to the conventional procedure of preparing Ag clusters from colloidal solutions. SERS active colloidal solutions require up to a full day to prepare. In addition, the preparations of colloidal aggregates are not consistent in shape, contain additional interfering chemicals, and do not generate consistent SERS enhancement. Colloidal solutions require the addition of KCl or NaCl to increase the ionic strength to allow aggregation and cluster formation. We find no need to add KCl or NaCl to create SERS active clusters in the holographic gelatin matrix. These holographic plates, prepared using simple, conventional procedures, can be stored in an inert environment and preserve SERS activity after several weeks subsequent to preparation. C1 Sandia Natl Labs, Livermore, CA 94550 USA. San Jose State Univ, Dept Phys, San Jose, CA 95192 USA. RP Jusinski, LE (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 28 TC 0 Z9 0 U1 1 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 0-8194-6141-5 J9 P SOC PHOTO-OPT INS PY 2006 VL 6099 BP 9901 EP 9901 AR 609901 DI 10.1117/12.643177 PG 7 WC Engineering, Biomedical; Nanoscience & Nanotechnology SC Engineering; Science & Technology - Other Topics GA BEL27 UT WOS:000237707700001 ER PT S AU Pelton, M Liu, MZ Kim, HY Smith, G Guyot-Sionnest, P Scherer, NF AF Pelton, Matthew Liu, Mingzhao Kim, Hee Y. Smith, Glenna Guyot-Sionnest, Philippe Scherer, Nobert F. BE Stockman, MI TI Optical trapping and alignment of single gold nanorods using plasmon resonances - art. no. 63230E SO Plasmonics: Metallic Nanostructures and their Optical Properties IV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Plasmonics - Metallic Nanostructures and their Optical Properties IV CY AUG 13-16, 2006 CL San Diego, CA SP SPIE DE nanorods; plasmons; optical trapping; nanofabrication; local probes ID BIASED DIFFUSION; CARBON NANOTUBES; NANOPARTICLES; MANIPULATION; SPECTROSCOPY; LUMINESCENCE; MICROSCOPY; PARTICLES; MOLECULES; MECHANISM AB We demonstrate three-dimensional optical trapping and orientation of individual Au nanorods in solution, taking advantage of the longitudinal surface-plasmon resonance to enhance optical forces. Stable trapping is achieved using laser light that is detuned slightly to the long-wavelength side of the resonance; by contrast, light detuned to the short-wavelength side repels rods from the laser focus. Under stable-trapping conditions, the trapping time depends exponentially on laser power, in agreement with a Kramers escape process. Trapped rods have their long axes aligned with the trapping-laser polarization, as evidenced by a suppression of rotational diffusion about the short axis. The ability to trap and orient individual metal nanoparticles may find important application in assembly of functional structures, sorting of nanoparticles according to their shape, and development of novel microscopy techniques. C1 Argonne Natl Lab, Ctr Nanoscale Mat, Argonne, IL 60439 USA. RP Pelton, M (reprint author), Argonne Natl Lab, Ctr Nanoscale Mat, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Pelton, Matthew/H-7482-2013 OI Pelton, Matthew/0000-0002-6370-8765 NR 34 TC 0 Z9 0 U1 0 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 0-8194-6402-3 J9 P SOC PHOTO-OPT INS PY 2006 VL 6323 BP E3230 EP E3230 AR 63230E DI 10.1117/12.680146 PG 9 WC Nanoscience & Nanotechnology; Optics SC Science & Technology - Other Topics; Optics GA BFI24 UT WOS:000241981600002 ER PT J AU Branch, KM Bradbury, JA AF Branch, Kristi M. Bradbury, Judith A. TI Comparison of DOE and army advisory boards: Application of a conceptual framework for evaluating public participation in environmental risk decision making SO POLICY STUDIES JOURNAL LA English DT Article ID CITIZEN PARTICIPATION; STAKEHOLDER PARTICIPATION; COMMUNITY INVOLVEMENT; TRUST; DELIBERATION; MANAGEMENT; DEMOCRACY; POLICY; INSTITUTIONS; PERSPECTIVES AB This article is part of a growing body of literature evaluating public participation approaches and implementation efforts. It compares the characteristics and performance of citizen advisory boards established by the U.S. Department of Energy's Environmental Restoration and Waste Management Program (DOE/EM) and by the U.S. Department of Defense's Army (DoD/Army) as a major part of the public participation programs that were undertaken to help the agencies plan and implement the cleanup of their contaminated installations. We first present the elements of the Acceptability Diamond, an evaluative framework developed by the authors through extensive fieldwork on public-federal agency interactions that identify five objectives of agency-public interactions and public participation programs, and link them to existing literature. We then use the Acceptability Diamond as a basis for comparing the performance of the DOE/EM and DoD/Army advisory boards. In the early 1990s, both DOE and DoD participated in the Federal Facilities Environmental Restoration Dialogue Committee (known as the FFER Dialogue Committee) and were influenced by the Committee's recommendations on public participation. However, the Site Specific Advisory Boards (SSABs) subsequently established by DOE/EM and the Restoration Advisory Boards (RABs) subsequently established by DoD and the Army were governed by significantly different policies and management. We describe some of these key differences and compare the performance of the SSABs and RABs. The article draws on a series of research studies conducted by the authors on the DOE/EM public participation program from its inception in the early 1990s through its transition to accelerated cleanup in 2002 and also on a recently completed study of seven Army RABs. C1 Pacific NW Natl Lab, Battelle Mem Inst, US DOE, Kristi Branch, Seattle, WA 98109 USA. RP Branch, KM (reprint author), Pacific NW Natl Lab, Battelle Mem Inst, US DOE, Kristi Branch, 1100 Dexter Ave N,Suite 400, Seattle, WA 98109 USA. EM kristi.branch@pnl.gov; judith.bradbury@pnl.gov NR 74 TC 13 Z9 13 U1 1 U2 6 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0190-292X J9 POLICY STUD J JI Policy Stud. J. PY 2006 VL 34 IS 4 BP 723 EP 753 DI 10.1111/j.1541-0072.2006.00199.x PG 31 WC Political Science; Public Administration SC Government & Law; Public Administration GA 117IO UT WOS:000242866800014 ER PT J AU Li, WG Jia, QX Wang, HL AF Li, WG Jia, QX Wang, HL TI Facile synthesis of metal nanoparticles using conducting polymer colloids SO POLYMER LA English DT Article DE conducting polymer; metal nanoparticles; synthesis ID CONJUGATED POLYMER; POLYANILINE; NANOCLUSTER; FABRICATION; CATALYSIS; CLUSTERS; FILMS; GOLD AB We report a simple method to synthesize Ag, An, and Pt nanoparticles with a reasonable size dispersity using water-dispersible conducting polymer colloids composed of polyaniline (PANI) and conventional polyelectrolyte. This facile synthesis results in single crystalline metal nanoparticles that are stable in an aqueous solution for at least several weeks. The process involves incrementally adding a metal ion solution to aqueous conducting polymer colloids and does not require reducing agents such as NaBH4. In addition, the complete synthetic and purification procedure is carried out in an aqueous solution; therefore, it is environmentally benign and potentially suitable for large-scale production. We have also demonstrated synthesis of larger nanoparticles and nanosheets by varying the experimental parameters. With the tunable oxidation states of conducting polymers, we expect this synthetic platform can synthesize a wide range of nanostructured metals with specific size, shape and properties. Finally, the nanoparticles embedded in the conducting polymer matrix, the metal-polyaniline nanocomposite itself may be interesting since it represents a type of materials where metallic nanoislands are embedded in a semiconducting matrix. (c) 2005 Elsevier Ltd. All rights reserved. C1 Los Alamos Natl Lab, Div Chem, Phys Chem & Spect Grp, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Wang, HL (reprint author), Los Alamos Natl Lab, Div Chem, Phys Chem & Spect Grp, MSJ-586, Los Alamos, NM 87545 USA. EM hwang@lanl.gov RI Jia, Q. X./C-5194-2008 NR 23 TC 95 Z9 97 U1 5 U2 20 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD JAN PY 2006 VL 47 IS 1 BP 23 EP 26 DI 10.1016/j.polymer.2005.11.032 PG 4 WC Polymer Science SC Polymer Science GA 002NG UT WOS:000234617600005 ER PT J AU Celina, M Clough, RL AF Celina, M Clough, RL TI Remote inhibition of polymer degradation SO POLYMER LA English DT Article DE thermal polymer degradation; material interaction; antioxidants and oxidation inhibition ID THERMAL-OXIDATION; CHEMILUMINESCENCE ANALYSIS; SOLID POLYPROPYLENE AB Polymer degradation has been explored on the basis of synergistic infectious and inhibitive interaction between separate materials. A dual stage chemiluminescence detection system with individually controlled hot stages was applied to probe for interaction effects during polymer degradation in an oxidizing environment. Experimental confirmation was obtained that volatile antioxidants can be transferred over a relatively large distance. The thermal degradation of a polypropylene (PP) sample receiving traces of inhibitive antioxidants from a remote source is delayed. Similarly, volatiles from two stabilized elastomers were also capable of retarding a degradation process remotely. This observation demonstrates inhibitive cross-talk as a novel interactive phenomenon between different polymers and is consequential for understanding general polymer interactions, fundamental degradation processes and long-term aging effects of multiple materials in a single environment. (c) 2005 Elsevier Ltd. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Celina, M (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM mccelin@sandia.gov NR 26 TC 7 Z9 7 U1 1 U2 8 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD JAN PY 2006 VL 47 IS 1 BP 289 EP 292 DI 10.1016/j.polymer.2005.11.041 PG 4 WC Polymer Science SC Polymer Science GA 002NG UT WOS:000234617600039 ER PT S AU Sun, J Yu, KH Russo, PS Pople, J Henry, A Lyles, B McCarley, RS Baker, GR Newkome, GR AF Sun, Jirun Yu, Keunok Han Russo, Paul S. Pople, John Henry, Alyssa Lyles, Bethany McCarley, Robin S. Baker, Gregory R. Newkome, George R. BE Reneker, DH Fong, H TI Some structural observations of self-assembled, fibrillar gels composed of two-directional bolaform arborols SO POLYMERIC NANOFIBERS SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT 226th National Meeting of the American-Chemical-Society CY SEP 07-11, 2003 CL NEW YORK, NY SP Amer Chem Soc ID CASCADE MOLECULES; ORGANIC-SOLVENTS; WATER; BOLAAMPHIPHILES; GELATION; SURFACTANTS; COPOLYMERS; SUBSTRATE; HYDROGELS; GELATORS AB Arborols are dumbbell shaped molecules (bolaform amphiphiles) in which a hydrophobic spacer separates two hydrophilic end groups. They are a valuable model for naturally occurring fibers, such as actin or amyloid. Applications to materials science can be envisioned. On cooling from warm aqueous or methanolic solutions, arborols spontaneously assemble into long fibers. When the solutions are above a certain concentration that depends on the hydrophilic / hydrophobic balance, this leads to thermally reversible gels stabilized by a mechanism that is poorly understood. With the help of wide-angle X-ray scattering, details of the arborol fiber and gel structure were obtained on wet gels. The characteristic dimensions of the fibers vary in a sensible fashion with the molecular specifics. Solvent character appears to affect the average domain length of arborols stacked into fibers. Fluorescently labeled arborols were prepared. The label does not prevent incorporation into the fibrillar structure, rendering fibril bundles visible in wet gels. Bundles are visible in concentrated gels, but not in less concentrated sols. These results are consistent with observations of dried arborols using atomic force microscopy and with previously published freeze-fracture electron microscopy and small-angle X-ray scattering experiments on dried gels. C1 Louisiana State Univ, Dept Chem, Baton Rouge, LA 70803 USA. Louisiana State Univ, Macromol Studies Grp, Baton Rouge, LA 70803 USA. Kunsan Natl Univ, Dept Chem, Kunsan 573360, South Korea. Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. Univ S Florida, Dept Chem, Tampa, FL 33620 USA. Univ Akron, Dept Chem & Polymer Sci, Akron, OH 44325 USA. RP Russo, PS (reprint author), Louisiana State Univ, Dept Chem, Baton Rouge, LA 70803 USA. EM chruss@LSU.edu RI Russo, Paul/G-6473-2012 NR 25 TC 3 Z9 3 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3919-3 J9 ACS SYM SER PY 2006 VL 918 BP 370 EP 383 PG 14 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Polymer Science SC Chemistry; Science & Technology - Other Topics; Polymer Science GA BEM23 UT WOS:000238115600026 ER PT J AU Banerjee, SS Goldberg, S Myasoedov, Y Rappaport, M Zeldov, E Soibel, A de la Cruz, F van der Beek, CJ Konczykowski, M Tamegai, T Vinokur, V AF Banerjee, SS Goldberg, S Myasoedov, Y Rappaport, M Zeldov, E Soibel, A de la Cruz, F van der Beek, CJ Konczykowski, M Tamegai, T Vinokur, V TI Melting of heterogeneous vortex matter: The vortex 'nanoliquid' SO PRAMANA-JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT 10th International Vortex Workshop CY JAN 09-14, 2005 CL Bombay, INDIA DE inhomogeneous vortex solid; BSCCO; melting; columnar defects; magneto-optical imaging; vortex liquid ID HIGH-TEMPERATURE SUPERCONDUCTORS; BOSE-GLASS PHASE; BI2SR2CACU2O8 CRYSTALS; FLAT SUPERCONDUCTORS; COLUMNAR DEFECTS; CURRENT PATTERNS; SINGLE-CRYSTALS; FLUX LINES; LATTICE; YBA2CU3O7-DELTA AB Disorder and porosity are parameters that strongly influence the physical behavior of materials, including their mechanical, electrical, magnetic and optical properties. Vortices in superconductors can provide important insight into the effects of disorder because their size is comparable to characteristic sizes of nanofabricated structures. Here we present experimental evidence for a novel form of vortex matter that consists of interconnected nanodroplets of vortex liquid caged in the pores of a solid vortex structure, like a liquid permeated into a nanoporous solid skeleton. Our nanoporous skeleton is formed by vortices pinned by correlated disorder created by high-energy heavy ion irradiation. By sweeping the applied magnetic field, the number of vortices in the nanodroplets is varied continuously from a few to several hundred. Upon cooling, the caged nanodroplets freeze into ordered nanocrystals through either a first-order or a continuous transition, whereas at high temperatures a uniform liquid phase is formed upon delocalization-induced melting of the solid skeleton. This new vortex nanoliquid displays unique properties and symmetries that are distinct from both solid and liquid phases. C1 Indian Inst Technol, Dept Phys, Kanpur 208016, Uttar Pradesh, India. Weizmann Inst Sci, Dept Condensed Matter Phys, IL-76100 Rehovot, Israel. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Comis Nacl Energia Atom, Inst Balseiro, RA-8400 San Carlos De Bariloche, Rio Negro, Argentina. Comis Nacl Energia Atom, Ctr Atom Bariloche, RA-8400 San Carlos De Bariloche, Rio Negro, Argentina. Ecole Polytech, Solides Irradies Lab, CNRS, UMR 7642, F-91128 Palaiseau, France. Ecole Polytech, CEA, DMS, DRECAM, F-91128 Palaiseau, France. Univ Tokyo, Dept Appl Phys, Bunkyo Ku, Tokyo 1138656, Japan. Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. RP Banerjee, SS (reprint author), Indian Inst Technol, Dept Phys, Kanpur 208016, Uttar Pradesh, India. EM satyajit@iitk.ac.in RI Tamegai, Tsuyoshi /C-6656-2011; Soibel, Alexander/A-1313-2007; Zeldov, Eli/K-1546-2012 OI Zeldov, Eli/0000-0002-8200-4974 NR 57 TC 0 Z9 0 U1 0 U2 1 PU INDIAN ACADEMY SCIENCES PI BANGALORE PA C V RAMAN AVENUE, SADASHIVANAGAR, P B #8005, BANGALORE 560 080, INDIA SN 0304-4289 J9 PRAMANA-J PHYS JI Pramana-J. Phys. PD JAN PY 2006 VL 66 IS 1 SI SI BP 43 EP 54 DI 10.1007/BF02704936 PG 12 WC Physics, Multidisciplinary SC Physics GA 008LN UT WOS:000235042300004 ER PT J AU Jaiswal-Nagar, D Pal, D Eskildsen, MR Canfield, PC Takeya, H Ramakrishnan, S Grover, AK AF Jaiswal-Nagar, D Pal, D Eskildsen, MR Canfield, PC Takeya, H Ramakrishnan, S Grover, AK TI Vortex phase diagram studies in the weakly pinned single crystals of YNi2B2C and LuNi2B2C SO PRAMANA-JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT 10th International Vortex Workshop CY JAN 09-14, 2005 CL Bombay, INDIA DE flux jumps; peak effect; second magnetisation peak; YNi2B2C; LuNi2B2C; vortex phase diagram ID FLUX-LINE-LATTICE; PEAK EFFECT PHENOMENON; UPPER CRITICAL-FIELD; BI2SR2CACU2O8 CRYSTALS; NEUTRON-SCATTERING; SUPERCONDUCTORS; 2H-NBSE2; YBA2CU3O7-DELTA; MAGNETIZATION; AMORPHIZATION AB We present a study of magnetization measurements performed on the single crystals of YNi2B2C and LuNi2B2C. For both the compounds, we find flux jumps in magnetisation values in the respective field regions, where the structural transitions in the flux line lattice symmetry have been reported in these systems via the small angle neutron scattering experiments. The magnetisation hysteresis loops and the AC susceptibility measurements show pronounced peak effect as well as second magnetisation peak anomaly for both YNi2B2C and LuNi2B2C. Based on these results, a vortex phase diagram has been constructed for YNi2B2C for H parallel to c depicting different glassy phases of the vortex matter. C1 Tata Inst Fundamental Res, Dept Condensed Matter Phys & Mat Sci, Bombay 400005, Maharashtra, India. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Natl Inst Mat Sci, Tsukuba, Ibaraki 305003, Japan. RP Jaiswal-Nagar, D (reprint author), Tata Inst Fundamental Res, Dept Condensed Matter Phys & Mat Sci, Homi Bhabha Rd, Bombay 400005, Maharashtra, India. EM shikha@tifr.res.in; grover@tifr.res.in RI Eskildsen, Morten/E-7779-2011; Canfield, Paul/H-2698-2014 NR 50 TC 9 Z9 9 U1 1 U2 3 PU INDIAN ACAD SCIENCES PI BANGALORE PA C V RAMAN AVENUE, SADASHIVANAGAR, P B #8005, BANGALORE 560 080, INDIA SN 0304-4289 EI 0973-7111 J9 PRAMANA-J PHYS JI Pramana-J. Phys. PD JAN PY 2006 VL 66 IS 1 SI SI BP 113 EP 129 DI 10.1007/BF02704941 PG 17 WC Physics, Multidisciplinary SC Physics GA 008LN UT WOS:000235042300009 ER PT J AU Movshovich, R Bianchi, A Capan, C Pagliuso, PG Sarrao, JL AF Movshovich, R Bianchi, A Capan, C Pagliuso, PG Sarrao, JL TI Possible Fulde-Ferrell-Larkin-Ovchinnikov inhomogeneous superconducting state in CeCoIn5 SO PRAMANA-JOURNAL OF PHYSICS LA English DT Article; Proceedings Paper CT 10th International Vortex Workshop CY JAN 09-14, 2005 CL Mumbai, INDIA DE inhomogeneous superconductivity; heavy fermion; Fulde-Ferrell; Larkin-Ovchinnikov ID TYPE-2 SUPERCONDUCTORS; THERMAL-CONDUCTIVITY; PAULI PARAMAGNETISM; MAGNETIC-PROPERTIES; HEAVY-FERMION; UPD2AL3; FIELD AB We present specific heat and thermal conductivity of the heavy fermion superconductor CeCoIn5 in the vicinity of the superconducting critical field H-c2, measured with magnetic field in the plane of this quasi-2D compound and at temperatures down to 50 mK. The superconducting phase diagram and the first order nature of the superconducting phase transition at high fields close to a critical field H-c2 indicate the importance of the Pauli limiting effect in CeCoIn5. In the same range of magnetic field we observe a second specific heat anomaly within the superconducting state, and interpret it as a signature of a Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) inhomogeneous superconducting state. In addition, the thermal conductivity data as a function of field display a kink at a field H-k below the superconducting critical field, which closely coincides with the low temperature anomaly in specific heat tentatively identified with the appearance of the FFLO superconducting state. The enhancement of thermal conductivity within the FFLO state calls for further theoretical investigations of the real space structure of the order parameter (and in particular, the structure of vortices) and of the thermal transport within the inhomogeneous FFLO state. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Hochfeldlabor Dresden Forschungszentrum Rossendor, D-01314 Dresden, Germany. Univ Estadual Campinas, Ins Fis Gleb Wathagin, BR-13083970 Campinas, SP, Brazil. RP Movshovich, R (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM roman@lanl.gov RI Pagliuso, Pascoal/C-9169-2012; Bianchi, Andrea/E-9779-2010 OI Bianchi, Andrea/0000-0001-9340-6971 NR 35 TC 1 Z9 1 U1 1 U2 4 PU INDIAN ACADEMY SCIENCES PI BANGALORE PA C V RAMAN AVENUE, SADASHIVANAGAR, P B #8005, BANGALORE 560 080, INDIA SN 0304-4289 J9 PRAMANA-J PHYS JI Pramana-J. Phys. PD JAN PY 2006 VL 66 IS 1 SI SI BP 227 EP 237 DI 10.1007/BF02704950 PG 11 WC Physics, Multidisciplinary SC Physics GA 008LN UT WOS:000235042300018 ER PT B AU Dragone, A De Geronimo, G Fried, J Kandasamy, A O'Connor, P Siddons, DP Vernon, E Corsi, F AF Dragone, A. De Geronimo, G. Fried, J. Kandasamy, A. O'Connor, P. Siddons, D. P. Vernon, E. Corsi, F. BE Malcovati, P Baschirotto, A TI Pile up rejection and multiple simultaneous events acquisition with the PDD ASIC SO PRIME 2006: 2ND CONFERENCE ON PH.D. RESEARCH IN MICROELECTRONIC AND ELECTRONICS, PROCEEDINGS LA English DT Proceedings Paper CT 2nd Conference on Ph D Research in MicroElectronics and Electronics CY JUN 12-15, 2006 CL Otranto, ITALY AB The Peak Detector Derandomizer ASIC provides threshold discrimination, arbitration, peak and timing detection with analog memorization, sparsification, and muldplexation for 32 input channels of analog pulse data. In this work the ASIC a new version of the ASIC, that can process multiple events occurring at the same time and can provide time-over-threshold measurement for pile up rejection, is presented. C1 [Dragone, A.; De Geronimo, G.; Fried, J.; Kandasamy, A.; O'Connor, P.; Siddons, D. P.; Vernon, E.] Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. [Dragone, A.; Corsi, F.] Elect & Elect Dept Polytech Bari, Bari, Italy. RP Dragone, A (reprint author), Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. OI CORSI, Francesco/0000-0003-2425-2272 FU Brookhaven Science Associates,LLC [DE-AC02- 98CH1-886]; U.S. Department of Energy FX This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-AC02- 98CH1-886 with the U.S. Department of Energy. NR 5 TC 0 Z9 1 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 1-4244-0156-9 PY 2006 BP 381 EP + PG 2 WC Engineering, Electrical & Electronic SC Engineering GA BEZ64 UT WOS:000240385600096 ER PT B AU Martin, E Varner, G Barbero, M Kennedy, J Tajima, H Arai, Y AF Martin, E. Varner, G. Barbero, M. Kennedy, J. Tajima, H. Arai, Y. BE Malcovati, P Baschirotto, A TI Hard X-ray SOI sensor prototype SO PRIME 2006: 2ND CONFERENCE ON PH.D. RESEARCH IN MICROELECTRONIC AND ELECTRONICS, PROCEEDINGS LA English DT Proceedings Paper CT 2nd Conference on Ph D Research in MicroElectronics and Electronics CY JUN 12-15, 2006 CL Otranto, ITALY ID ACTIVE PIXEL SENSORS; DETECTORS; TRACKING; CHIP AB A prototype Silicon On Insulator (SOI) sensor has been developed for the study of polarized hard x-ray emissions. A 4x4 sensor cell and basic circuitry have been designed using a novel SOI process. A prototype board and a user interface have also been developed in order to control and bias the sensor. The SOI sensor has been optimized to work at low voltage and low power. C1 [Martin, E.; Varner, G.; Barbero, M.; Kennedy, J.] Univ Hawaii, Dept Phys & Astron, Honolulu, HI 96822 USA. [Tajima, H.] Stanford Univ, Stanford Linear Accelerator Ctr, Palo Alto, CA USA. [Arai, Y.] KEK, High Energy Accelerator Res Org, Tsukuba, Ibaraki, Japan. RP Martin, E (reprint author), Univ Hawaii, Dept Phys & Astron, Honolulu, HI 96822 USA. EM elenam@phys.hawaii.edu FU Natural Sciences at the University of Hawaii; KEK Detector Technology Development; OKI Electric Industry Co., Ltd. FX The authorsthank the College of Natural Sciences at the University of Hawaii and KEK Detector Technology Development project for their support of this project; and also M. Ohno, K. Tani and J. Ida of OKI Electric Industry Co., Ltd. for their persevering support. NR 13 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 1-4244-0156-9 PY 2006 BP 417 EP + PG 2 WC Engineering, Electrical & Electronic SC Engineering GA BEZ64 UT WOS:000240385600105 ER PT J AU Ionita, A Weitsman, YJ AF Ionita, A Weitsman, YJ TI Randomly reinforced composites: properties, failure and aspects of material design SO PROBABILISTIC ENGINEERING MECHANICS LA English DT Article DE polymeric composites; random reinforcement; size effects; stiffness; failure ID FIBER NETWORKS; THERMOPLASTIC COMPOSITES AB This article concerns several aspects of mechanical properties and tensile failure of randomly reinforced, chopped fiber strand, polymeric composites. Scatter in material properties and their dependence on sample size are investigated by means of an analytical/computational model and compared against the experimental data. Predictions are also provided for deviations from isotropy and homogeneity. Failure is modeled in a manner akin to the methodology employed for laminated composites and predictions are compared against the experimental data. The model is utilized to select combinations of multi-size strands so as to minimize material inhomogeneity. (c) 2005 Elsevier Ltd. All rights reserved. C1 Univ Tennessee, Dept Mech & Aerosp Engn & Engn Sci, Knoxville, TN 37996 USA. RP Weitsman, YJ (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. EM weitsman@utk.edu NR 17 TC 4 Z9 5 U1 1 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0266-8920 J9 PROBABILIST ENG MECH JI Probab. Eng. Eng. Mech. PD JAN PY 2006 VL 21 IS 1 BP 64 EP 72 DI 10.1016/j.probengmech.2005.07.006 PG 9 WC Engineering, Mechanical; Mechanics; Statistics & Probability SC Engineering; Mechanics; Mathematics GA 006NU UT WOS:000234905000007 ER PT B AU Kumar, A Tanner, HG Klimenko, AV Borozdin, K Priedhorsky, WC AF Kumar, A. Tanner, H. G. Klimenko, A. V. Borozdin, K. Priedhorsky, W. C. GP IEEE TI Automated sequential search for weak radiation sources SO PROCEEDINGS OF 2006 MEDITERRANEAN CONFERENCE ON CONTROL AND AUTOMATION, VOLS 1 AND 2 LA English DT Proceedings Paper CT 14th Mediterranean Conference on Control and Automation CY JUN 28-30, 2006 CL Ancona, ITALY AB We demonstrate the principle of a bidirectional interaction between the perception model that describes the environment, and the sensor data collection that shapes the model, through the first automated scheme for sequential nuclear search. The objective is to detect and localize a weak radioactive point source, with consideration to the time spent for the search. Numerical simulations verify that desired false positive and false negative rates can be achieved using the control algorithm developed for deployment on prototype system. The simulation results are also consistent with previous theoretical, discrete simulation of the sequential search strategy that our continuous search control algorithm is based on. C1 [Kumar, A.; Tanner, H. G.] Univ New Mexico, Dept Mech Engn, MSC01 1150, Albuquerque, NM 87131 USA. [Klimenko, A. V.; Borozdin, K.; Priedhorsky, W. C.] Los Alamos Natl Lab, Nonproliferat & Int Secur Div, Los Alamos, NM 87545 USA. RP Kumar, A (reprint author), Univ New Mexico, Dept Mech Engn, MSC01 1150, Albuquerque, NM 87131 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-0-9786720-1-0 PY 2006 BP 245 EP + PG 2 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Robotics SC Automation & Control Systems; Computer Science; Robotics GA BFP78 UT WOS:000243663000043 ER PT B AU Robinett, RD Wilson, DG AF Robinett, Rush D., III Wilson, David G. GP IEEE TI Exergy and irreversible entropy production thermodynamic concepts for control design: Nonlinear systems SO PROCEEDINGS OF 2006 MEDITERRANEAN CONFERENCE ON CONTROL AND AUTOMATION, VOLS 1 AND 2 LA English DT Proceedings Paper CT 14th Mediterranean Conference on Control and Automation CY JUN 28-30, 2006 CL Ancona, ITALY ID STATE-SPACE THEORY; ENERGY CONCEPTS; PASSIVITY; PORTS AB This paper(1) develops a novel control system design methodology that uniquely combines: concepts from thermodynamic exergy and entropy; Hamiltonian systems; Lyapunov's direct method and Lyapunov optimal analysis; electric AC power concepts; and power flow analysis. Relationships are derived between exergy/entropy and Lyapunov optimal functions for Hamiltonian systems. The methodology is demonstrated with two fundamental numerical simulation examples: 1) a Duffing oscillator/Coulomb friction nonlinear model that employs PID regulator control and 2) a van der Pol nonlinear oscillator system. The control system performances and/or appropriately identified terms are partitioned and evaluated based on exergy generation and exergy dissipation terms. This novel nonlinear control methodology results in both necessary and sufficient conditions for stability of nonlinear systems. C1 [Robinett, Rush D., III] Sandia Natl Labs, Energy Infrastruct & Knowledge Syst, POB 5800, Albuquerque, NM 87185 USA. [Wilson, David G.] Sandia Natl Labs, Intelligent Syst & Ronot Ctr, POB 5800, Albuquerque, NM 87185 USA. RP Robinett, RD (reprint author), Sandia Natl Labs, Energy Infrastruct & Knowledge Syst, POB 5800, Albuquerque, NM 87185 USA. EM rdrobin@sandia.gov; dwilso@sandia.gov NR 23 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-0-9786720-1-0 PY 2006 BP 1017 EP + PG 3 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Robotics SC Automation & Control Systems; Computer Science; Robotics GA BFP78 UT WOS:000243663000175 ER PT B AU Lipnikov, K Vassilevski, Y AF Lipnikov, Konstantin Vassilevski, Yuri BE Pebay, PP TI Analysis of Hessian recovery methods for generating adaptive meshes SO PROCEEDINGS OF THE 15TH INTERNATIONAL MESHING ROUNDTABLE LA English DT Proceedings Paper CT 15th International Meshing Roundtable CY SEP 17-20, 2006 CL Birmingham, AL ID POSTERIORI ERROR ESTIMATORS AB We study adaptive meshes which are quasi-uniform in a metric generated by the Hessian of a P-1 finite element function. We consider three most efficient methods for recovering this Hessian, one variational method and two projection methods. We compare these methods for problems with anisotropic singularities to show that all Hessian recovery methods result in acceptable adaptive meshes although the variational method gives a smaller error. C1 [Lipnikov, Konstantin] Los Alamos Natl Lab, Los Alamos, NM 87545 USA. [Vassilevski, Yuri] Inst Numer Math, Los Alamos, NM 87545 USA. RP Lipnikov, K (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EM lipnikov@lanl.gov; vasilevs@dodo.inm.ras.ru RI Vassilevski, Yuri/A-6068-2016 FU RFBR [04-07-90336] FX The work of the second author was supported in part by the RFBR grant 04-07-90336 and the academic programs Computational and informatic issues of the solution of large problems and Modern problems in theoretical mathematics. NR 12 TC 3 Z9 4 U1 0 U2 2 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY BN 3-540-34957-X PY 2006 BP 163 EP + DI 10.1007/978-3-540-34958-7_10 PG 2 WC Mathematics, Applied; Mathematics SC Mathematics GA BFK62 UT WOS:000242498300010 ER PT B AU Carbonera, CD Shepherd, JF AF Carbonera, Carlos D. Shepherd, Jason F. BE Pebay, PP TI A constructive approach to constrained hexahedral mesh generation SO PROCEEDINGS OF THE 15TH INTERNATIONAL MESHING ROUNDTABLE LA English DT Proceedings Paper CT 15th International Meshing Roundtable CY SEP 17-20, 2006 CL Birmingham, AL C1 [Carbonera, Carlos D.] Univ Puerto Rico, Gauss Res Lab, Rio Piedras, PR 00931 USA. [Shepherd, Jason F.] Univ Utah, Scientif Comp & Imaging Inst, Salt Lake City, UT USA. [Shepherd, Jason F.] Sandia Natl Labs, Computat Modeling Sci Dept, Albuquerque, NM USA. RP Carbonera, CD (reprint author), Univ Puerto Rico, Gauss Res Lab, Rio Piedras, PR 00931 USA. EM carbonera@uprr.pr; jfsheph@sci.utah.edu FU US Department of Energy's National Nuclear Security Administration [DE-AC04-94AL85000] FX The authors would like to express appreciation to Scott Mitchell for his review of the paper, and the many additional insights provided. We would also like to thank Cynthia Phillips, M. Gopi, and David Eppstein for their guidance and expertise in graph theory which enabled us to formulate a proof for perfect matching of closed quadrilateral meshes. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the US Department of Energys National Nuclear Security Administration under contract DE-AC04-94AL85000. NR 9 TC 6 Z9 6 U1 0 U2 1 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY BN 3-540-34957-X PY 2006 BP 435 EP + DI 10.1007/978-3-540-34958-7_25 PG 2 WC Mathematics, Applied; Mathematics SC Mathematics GA BFK62 UT WOS:000242498300025 ER PT B AU Staten, ML Kerr, RA Owen, SJ Blacker, TD AF Staten, Matthew L. Kerr, Robert A. Owen, Steven J. Blacker, Ted D. BE Pebay, PP TI Unconstrained paving and plastering: Progress update SO PROCEEDINGS OF THE 15TH INTERNATIONAL MESHING ROUNDTABLE LA English DT Proceedings Paper CT 15th International Meshing Roundtable CY SEP 17-20, 2006 CL Birmingham, AL ID MESH GENERATION AB Unconstrained Paving and Plastering [1] were introduced as new methods of generating all-quadrilateral and all-hexahedral finite element meshes. Their introduction was after preliminary conceptual studies. This paper presents an update on Unconstrained Paving and Plastering after significant implementation and conceptual development. C1 [Staten, Matthew L.; Kerr, Robert A.; Owen, Steven J.; Blacker, Ted D.] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Staten, ML (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. EM mlstate@sandia.gov; rakerr@sandia.gov; sjowen@sandia.gov; tdblack@sandia.gov NR 19 TC 23 Z9 24 U1 0 U2 1 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY BN 3-540-34957-X PY 2006 BP 469 EP + DI 10.1007/978-3-540-34958-7_27 PG 2 WC Mathematics, Applied; Mathematics SC Mathematics GA BFK62 UT WOS:000242498300027 ER PT S AU Robinett, RD Wilson, DG AF Robinett, Rush D., III Wilson, David G. GP IEEE TI Exergy and irreversible entropy production thermodynamic concepts for control system design: Regulators SO Proceedings of the 2006 IEEE International Conference on Control Applications, Vols 1-4 SE IEEE International Conference on Control Applications LA English DT Proceedings Paper CT IEEE International Conference on Control Applications CY OCT 04-06, 2006 CL Munich, GERMANY SP IEEE ID STATE-SPACE THEORY; NONLINEAR-SYSTEMS; ENERGY CONCEPTS; PASSIVITY; PORTS AB This paper develops a novel control system design methodology that uniquely combines: concepts from thermodynamic exergy and entropy; Hamiltonian systems; Lyapunov's direct method and Lyapunov optimal analysis; electric AC power concepts; and power flow analysis. Relationships are derived between exergy/entropy and Lyapunov optimal functions for Hamiltonian systems. The methodology is demonstrated with a couple of fundamental numerical simulation examples: 1) a PID regulator control for a linear mass-spring-damper system and 2) a Duffing oscillator/Coulomb friction nonlinear model that employs PID regulator control. The control system performances are partitioned and evaluated based on exergy generation and exergy dissipation terms. This novel nonlinear control methodology results in both necessary and sufficient conditions for stability of nonlinear systems. C1 Sandia Natl Labs, Energy Infrastructure & Knowledge Syst, Albuquerque, NM 87185 USA. Sandia Natl Labs, Intelligent Syst & Robot Ctr, Albuquerque, NM 87185 USA. RP Robinett, RD (reprint author), Sandia Natl Labs, Energy Infrastructure & Knowledge Syst, POB 5800, Albuquerque, NM 87185 USA. NR 23 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1085-1992 BN 978-0-7803-9795-8 J9 IEEE INTL CONF CONTR PY 2006 BP 1428 EP 1435 PG 8 WC Automation & Control Systems SC Automation & Control Systems GA BFW99 UT WOS:000245233802060 ER PT B AU Stalnaker, JE Diddams, SA Kim, K Hollberg, L Donley, EA Heavner, TP Jefferts, SR Levi, F Parker, TE Bergquist, JC Itano, WM Jensen, MJ Lorini, L Oskay, WH Fortier, TM AF Stalnaker, J. E. Diddams, S. A. Kim, K. Hollberg, L. Donley, E. A. Heavner, T. P. Jefferts, S. R. Levi, F. Parker, T. E. Bergquist, J. C. Itano, W. M. Jensen, M. J. Lorini, L. Oskay, W. H. Fortier, T. M. GP IEEE TI Absolute optical frequency measurements with a fractional frequency uncertainty at 1 X 10(-15) SO PROCEEDINGS OF THE 2006 IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM AND EXPOSITION, VOLS 1 AND 2 LA English DT Proceedings Paper CT IEEE International Frequency Control Symposium and Exposition CY JUN 04-07, 2006 CL Miami, FL SP IEEE ID MODE-LOCKED LASERS; RECENT IMPROVEMENTS; ACCURACY; NIST-F1; GENERATION; STABILITY; LEVEL; NOISE; ION AB We report the technical details specific to our recent measurements of the optical frequency of the mercury single-ion frequency standard in terms of the SI second as realized by the NIST-F1 cesium fountain clock. In these measurements the total fractional uncertainty is approximate to 10(-15), limited by the statistical measurement uncertainty. In this paper we will address the techniques employed for the optical-to-microwave comparison itself, which had an estimated fractional uncertainty of similar to 3 x 10(-16), limited by the stability of the electronics used for the comparison. C1 [Stalnaker, J. E.; Diddams, S. A.; Kim, K.; Hollberg, L.; Donley, E. A.; Heavner, T. P.; Jefferts, S. R.; Levi, F.; Parker, T. E.; Bergquist, J. C.; Itano, W. M.; Jensen, M. J.; Lorini, L.; Oskay, W. H.] Natl Inst Stand & Technol, Time & Frequency Div MS 847, Boulder, CO 80305 USA. [Fortier, T. M.] Los Alamos Natl Lab, Div Phys P23, MS H803, Los Alamos, NM 87545 USA. RP Stalnaker, JE (reprint author), Natl Inst Stand & Technol, Time & Frequency Div MS 847, Boulder, CO 80305 USA. RI Diddams, Scott/L-2819-2013 FU NIST; NASA; LANL FX The authors thank T. Rosenband, D. Hume, D. Wineland,and J. Torgerson for their contributions to this work. This work is a contribution of NIST and is not subject to U.S. Copyright. Funding for this work was provided by NIST, NASA, and LANL. NR 25 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0073-7 PY 2006 BP 462 EP + PG 3 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Materials Science, Multidisciplinary; Optics SC Engineering; Instruments & Instrumentation; Materials Science; Optics GA BFP95 UT WOS:000243684700087 ER PT B AU Beaucage, TR Beenfeldt, EP Speakman, SA Porter, WD Payzant, EA da Cunha, MP AF Beaucage, T. R. Beenfeldt, E. P. Speakman, S. A. Porter, W. D. Payzant, E. A. da Cunha, M. Pereira GP IEEE TI Comparison of high temperature crystal lattice and bulk thermal expansion measurements of LGT single crystal SO PROCEEDINGS OF THE 2006 IEEE INTERNATIONAL FREQUENCY CONTROL SYMPOSIUM AND EXPOSITION, VOLS 1 AND 2 LA English DT Proceedings Paper CT IEEE International Frequency Control Symposium and Exposition CY JUN 04-07, 2006 CL Miami, FL SP IEEE AB Among the langasite family of crystals (LGX), the three most popular materials are langasite (LGS, La3Ga5SiO14), langatate (LGT, La3Ga5.5T0.5O14) and langanite (LGN, La3Ga5.5Nb0.5O14). The LGX crystals have received significant attention for acoustic wave (AW) device applications due to several properties, which include: (1) piezoelectric constants about two and a half times those of quartz, thus allowing the design of larger bandwidth filters; (2) existence of temperature compensated orientations; (3) high density, with potential for reduced vibration and acceleration sensitivity; and (4) possibility of operation at high temperatures, since the LGX crystals do not present phase changes up to their melting point above 1400 degrees C. The LGX crystals' capability to operate at elevated temperatures calls for an investigation on the growth quality and the consistency of these materials' properties at high temperature. One of the fundamental crystal properties is the thermal expansion coefficients in the entire temperature range where the material is operational. This work focuses on the measurement of the LGT thermal expansion coefficients from room temperature (25 degrees C) to 1200 degrees C. Two methods of extracting the thermal expansion coefficients have been used and compared: a.) dual push-rod dilatometry, which provides the bulk expansion; and b.) x-ray powder diffraction, which provides the lattice expansion. Both methods were performed over the entire temperature range and considered multiple samples taken from < 001 > Czochralski grown LGT material. The thermal coefficients of expansion were extracted by approximating each expansion data set to a third order polynomial fit over three temperature ranges reported in this work: 25 degrees C to 400 degrees C, 400 degrees C to 900 degrees C, 900 degrees C to 1200 degrees C. An accuracy of fit better than 35ppm for the bulk expansion and better than 10ppm for the lattice expansion have been obtained with the aforementioned polynomial fitting. The percentage difference between the bulk and the lattice fitted expansion responses over the entire temperature range of 25 degrees C to 1200 degrees C is less than 2% for the three crystalline axes, which indicates the high quality and growth consistency of the LGT crystal measured. C1 [Beaucage, T. R.; Beenfeldt, E. P.; da Cunha, M. Pereira] Univ Maine, Surface Sci & Technol Lab, Dept Elect & Comp Engn, Orono, ME 04469 USA. [Speakman, S. A.; Porter, W. D.; Payzant, E. A.] Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN USA. RP Beaucage, TR (reprint author), Univ Maine, Surface Sci & Technol Lab, Dept Elect & Comp Engn, Orono, ME 04469 USA. EM Timothy_Beaucage@umit.maine.edu; mdacunha@eece.maine.edu RI Payzant, Edward/B-5449-2009 OI Payzant, Edward/0000-0002-3447-2060 FU Army Research Office ARO [DAAD19-03-1-0117]; Assistant Secretary for Energy Efficiency and Renewable Energy; Office of FreedomCAR and Vehicle Technologies, as part of the High Temperature Materials Laboratory User Program; Oak Ridge National Laboratory; U.S. Department of Energy [DE-AC05-00OR22725] FX This research has been funded by the Army Research Office ARO Grant # DAAD19-03-1-0117. The research has also been sponsored by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of FreedomCAR and Vehicle Technologies, as part of the High Temperature Materials Laboratory User Program, Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract number DE-AC05- 00OR22725. NR 20 TC 17 Z9 17 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0073-7 PY 2006 BP 658 EP + DI 10.1109/FREQ.2006.275465 PG 2 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Materials Science, Multidisciplinary; Optics SC Engineering; Instruments & Instrumentation; Materials Science; Optics GA BFP95 UT WOS:000243684700122 ER PT S AU Masanet, E Horvath, A AF Masanet, Eric Horvath, Arpad GP IEEE Computer Society TI Enterprise strategies for reducing the life-cycle energy use and greenhouse gas emissions of personal computers SO PROCEEDINGS OF THE 2006 IEEE INTERNATIONAL SYMPOSIUM ON ELECTRONICS & THE ENVIRONMENT, CONFERENCE RECORD SE IEEE International Symposium on Electronics and the Environment-ISEE LA English DT Proceedings Paper CT 14th IEEE International Symposium on Electronics and the Environment (ISEE)/7th Electronics Recycling Summit CY MAY 08-11, 2006 CL San Francisco, CA SP IEEE Comp Soc, TCEE, Int Assoc Elect Recyclers AB This paper examines the effectiveness of several important enterprise strategies for reducing the life-cycle energy use and greenhouse gas (GHG) emissions of office computers. A modeling framework is presented, which quantifies the annual primary energy use and GHG emissions necessary to maintain and operate an enterprise personal computer (PC) stock. The case of a California-based enterprise with 5,000 desktop PCs is considered as a baseline scenario. The model is applied to estimate technically-achievable reductions in life-cycle energy use and GHG emissions associated with six common enterprise PC management strategies, as compared to the baseline scenario. The total technical potential for primary energy savings is estimated at roughly 60%; the total technical potential for GHG savings is estimated at roughly 35%. C1 [Masanet, Eric] Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. [Horvath, Arpad] Univ Calif Berkeley, Dept Civil & Environm Engn, Berkeley, CA USA. RP Masanet, E (reprint author), Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. EM ermasanet@lbl.gov; horvath@ce.berkeley.edu RI Masanet, Eric /I-5649-2012 FU California Energy Commission, through its Public Interest Energy Research (PIER) Program; University of California Energy Institute, through its California Energy Studies (CES) Grant Program FX This work was funded by the California Energy Commission, through its Public Interest Energy Research (PIER) Program, and the University of California Energy Institute, through its California Energy Studies (CES) Grant Program. NR 18 TC 4 Z9 5 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-2020 BN 1-4244-0351-0 J9 IEEE INT SYMP ELECTR PY 2006 BP 21 EP + DI 10.1109/ISEE.2006.1650025 PG 2 WC Engineering, Environmental; Engineering, Electrical & Electronic SC Engineering GA BEV84 UT WOS:000239657400005 ER PT S AU Brady, T DePaoli, D Solomon, J Wooldridge, T AF Brady, Todd DePaoli, David Solomon, Jack Wooldridge, Tim GP IEEE Computer Society TI ESH & nanotechnology: A joint study by the Chemical Industry Vision2020 and the Semiconductor Research Corporation SO PROCEEDINGS OF THE 2006 IEEE INTERNATIONAL SYMPOSIUM ON ELECTRONICS & THE ENVIRONMENT, CONFERENCE RECORD SE IEEE International Symposium on Electronics and the Environment-ISEE LA English DT Proceedings Paper CT 14th IEEE International Symposium on Electronics and the Environment (ISEE)/7th Electronics Recycling Summit CY MAY 08-11, 2006 CL San Francisco, CA SP IEEE Comp Soc, TCEE, Int Assoc Elect Recyclers DE nanotechnology; environment; health; safety; research needs ID WALL CARBON NANOTUBES; PULMONARY TOXICITY; PARTICLES; ULTRAFINE; RATS AB Nanotechnology is and will be the foundation for exciting new technologies for years to come. Much of nanotechnology's promise is related to the unique properties that materials exhibit on the nanoscale. With such promise come questions concerning the environmental, safety and health (ESH) of the new technologies. As a result, a cross functional team of ESH experts from the chemical and semiconductor industries, with inputs from academic and governmental representatives, reviewed existing ESH and nanotechnology research and developed a list of over 30 research areas where ESH questions were unanswered. From this list, the top five research needs were identified and further explored based on the expertise of the team. C1 [Brady, Todd] Intel Corp, Santa Clara, CA 85248 USA. [DePaoli, David] Oak Ridge Natl Lab, Oak Ridge, TN USA. [Solomon, Jack] Chem Ind Vis 2020, Washington, DC USA. [Wooldridge, Tim] Semicond Res Corp, Durham, NC USA. RP Brady, T (reprint author), Intel Corp, Santa Clara, CA 85248 USA. EM todd.a.brady@intel.com; depaolidw@ornl.gov; Jacksolomon1@Gmail.com; Tim.Wooldridge@src.org NR 13 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1095-2020 BN 1-4244-0351-0 J9 IEEE INT SYMP ELECTR PY 2006 BP 27 EP + DI 10.1109/ISEE.2006.1650026 PG 2 WC Engineering, Environmental; Engineering, Electrical & Electronic SC Engineering GA BEV84 UT WOS:000239657400006 ER PT B AU Phillips, LR Cartes, D Liu, WX Cox, D Davis, T AF Phillips, Laurence R. Cartes, Dave Liu, Wenxin Cox, Daniel Davis, Tom GP IEEE TI Agents and islands: Managing a power system before, during, and after transition to the islanded state SO PROCEEDINGS OF THE 2006 IEEE/SMC INTERNATIONAL CONFERENCE ON SYSTEM OF SYSTEMS ENGINEERING LA English DT Proceedings Paper CT IEEE/SMC International Conference on System of Systems Engineering CY APR 24-26, 2006 CL Los Angeles, CA SP IEEE, SMC DE power system; islanding; agents; agent-based AB This paper presents a fictional scenario describing the effects of a category four hurricane on a metropolitan area, accompanied by a challenge: Describe, and eventually realize, a system able to carry out the necessary power system operations without human participation. We outline the capabilities of an automated system for managing electric power. The overarching task of the automated system is islanding: To separate the metro area's power system from the primary power grid and manage its operation during several hurricane-induced contingencies, with the power system operational throughout. The essential technology needed to support this automation is agents. We address the roles agents play in the transition to the islanded state and in power system operation within the island; features of an appropriate agent substrate; the way the agents are organized; and information exchange among agents, the power system, and human operators. C1 [Phillips, Laurence R.] Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. [Cartes, Dave; Liu, Wenxin] Florida State Univ, Tallahassee, FL 32306 USA. [Cox, Daniel] Univ North Florida, Jacksonville, FL 32224 USA. [Davis, Tom] Harris Corp, Jacksonville, FL USA. RP Phillips, LR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM lrphill@sandia.gov; dave@caps.fsu.edu; wliu@caps.fsu.edu; dcox@unf.edu; tom.davis@harrisgroup.com NR 8 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0187-1 PY 2006 BP 161 EP + PG 2 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Telecommunications SC Automation & Control Systems; Computer Science; Telecommunications GA BFZ13 UT WOS:000245541700028 ER PT B AU Zhu, MX Wu, QS Yang, YF Zhou, JZ AF Zhu, Mengxia Wu, Qishi Yang, Yunfeng Zhou, Jizhong GP IEEE TI A new approach to identify functional modules using random matrix theory SO PROCEEDINGS OF THE 2006 IEEE SYMPOSIUM ON COMPUTATIONAL INTELLIGENCE IN BIOINFORMATICS AND COMPUTATIONAL BIOLOGY LA English DT Proceedings Paper CT IEEE Symposium on Computational Intelligence in Bioinformatics and Computational Biology CY SEP 28-29, 2006 CL Toronto, CANADA DE Random Matrix; microarray; Pearson correlation; eigenvalue; eigenvector; varimax orthogonal rotation AB The advance in high-throughput genomic technologies including microarrays has generated a tremendous amount of gene expression data for the entire genome. Deciphering transcriptional networks that convey information on members of gene clusters and cluster interactions is a crucial analysis task in the post-sequence era. Most of the existing analysis methods for large-scale genome-wide gene expression profiles involve several steps that often require human intervention. We propose a random matrix theory-based approach to analyze the cross correlations of gene expression data in an entirely automatic and objective manner to eliminate the ambiguities and subjectivity inherent to human decisions. The correlations calculated from experimental measurements typically contain both "genuine" and "random" components. In the proposed approach, we remove the "random" component by testing the statistics of the eigenvalues of the correlation matrix against a "null hypothesis" - a truly random correlation matrix obtained from mutually uncorrelated expression data series. Our investigation on the components of deviating eigenvectors using varimax orthogonal rotation reveals distinct functional modules. We apply the proposed approach to the publicly available yeast cycle expression data and produce a transcriptional network that consists of interacting functional modules. The experimental results nicely conform to those obtained in previously published literatures. C1 [Zhu, Mengxia] South Illinois Univ, Dept Comp Sci, Carbondale, IL 62901 USA. [Wu, Qishi] Univ Memphis, Dept Comp Sci, Memphis, TN 38152 USA. [Yang, Yunfeng] Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. [Zhou, Jizhong] Univ Oklahoma, Dept Bot & Microbiol, Norman, OK 73019 USA. RP Zhu, MX (reprint author), South Illinois Univ, Dept Comp Sci, Carbondale, IL 62901 USA. EM mengxia@cs.siu.edu; qishiwu@memphis.edu; yangy@ornl.gov; jzhou@ou.edu RI Yang, Yunfeng/H-9853-2013 OI Yang, Yunfeng/0000-0001-8274-6196 NR 10 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 1-4244-0623-4 PY 2006 BP 117 EP + PG 2 WC Mathematical & Computational Biology SC Mathematical & Computational Biology GA BFW23 UT WOS:000245066100017 ER PT S AU Tang, LX Su, GJ Huang, XH AF Tang, Lixin Su, Gui-jia Huang, Xianghui GP IEEE TI Experimental high performance control of two permanent magnet synchronous machines in an integrated drive for automotive applications SO Proceedings of the 2006 IEEE Workshop on Computers in Power Electronics SE ANNUAL WORKSHOP ON COMPUTERS IN POWER ELECTRONICS LA English DT Proceedings Paper CT 10th IEEE Workshop on Computers in Power Electronics CY JUL 16-19, 2006 CL Rensselaer Polytechn Inst, Troy, NY SP IEEE Power Elect Soc, Powersim Inc, ASTEC Power HO Rensselaer Polytechn Inst DE permanent magnet motors; closed-loop systems ID SPACE AB Closed-loop control of an integrated dual-inverter which is able to drive two permanent magnet motors independently is presented and evaluated experimentally. By utilizing the neutral point of the main traction motor, only two inverter legs are needed for the two-phase auxiliary motor. A modified field oriented control scheme for this integrated inverter was introduced and employed in real-time control. Experimental results show that the inverter is able to control two drives independently. An integrated, component-count-reduced drive is achieved. C1 Oak Ridge Associated Univ, Knoxville, TN 37932 USA. GE Global Res, Niskayuna, NY 12309 USA. RP Tang, LX (reprint author), Oak Ridge Associated Univ, Knoxville, TN 37932 USA. RI Tang, Lixin/B-9242-2009 OI Tang, Lixin/0000-0001-8361-8196 NR 7 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1093-5142 BN 978-0-7803-9724-8 J9 ANN WORKSH COMP POW PY 2006 BP 186 EP 192 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA BFZ39 UT WOS:000245606400030 ER PT B AU Ciatti, SA Wallner, T Ng, H Stockhausen, WF Boyer, B AF Ciatti, Stephen A. Wallner, Thomas Ng, Henry Stockhausen, William F. Boyer, Brad GP ASME TI Study of combustion anomalies of H-2-ICE with external mixture formation SO Proceedings of the 2006 Spring Technical Conference of the ASME Internal Combustion Engine Division LA English DT Proceedings Paper CT Spring Technical Conference of the ASME Internal Combustion Engine Division CY MAY 08-10, 2006 CL Aachen, GERMANY SP ASME, Internal Combust Engine Div, FEV Motorentechnik GmbH AB Although hydrogen is considered one of the most promising future energy carriers, there are several challenges to achieving a "hydrogen economy," including finding a practical, efficient, cost-effective end-use device. Using hydrogen as a fuel for internal combustion engines is seen as a bridging technology toward a large-scale hydrogen infrastructure. To facilitate high-efficiency, high-power-density use of hydrogen with near-zero emissions in an internal combustion engine, detailed analysis of the hydrogen combustion process is necessary. This paper presents thermodynamic results regarding engine performance and emissions behavior during investigations performed on a single-cylinder research engine fueled by pressurized gaseous hydrogen. Avoiding combustion anomalies is one of the necessary steps to further improve the hydrogen engine power output at high-load operation while, at the same time, reducing fuel consumption and emissions during part-load operation. The overall target of the investigations is an improved combustion concept especially designed for hydrogen-engine-powered vehicles. Future activities include performing optical imaging of hydrogen combustion by using an endoscope. We will also investigate supercharged external mixture formation, as well as hydrogen direct-injection operation. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Ciatti, SA (reprint author), Argonne Natl Lab, Argonne, IL 60439 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 0-7918-4206-1 PY 2006 BP 421 EP 427 PG 7 WC Engineering, Mechanical; Transportation Science & Technology SC Engineering; Transportation GA BFO17 UT WOS:000243399700044 ER PT B AU Longman, DE Cole, RL Aggarwal, SK AF Longman, Douglas E. Cole, Roger L. Aggarwal, Suresh K. GP ASME TI In-cylinder injection of oxygen-enriched air to reduce diesel exhaust emissions SO Proceedings of the 2006 Spring Technical Conference of the ASME Internal Combustion Engine Division LA English DT Proceedings Paper CT Spring Technical Conference of the ASME Internal Combustion Engine Division CY MAY 08-10, 2006 CL Aachen, GERMANY SP ASME, Internal Combust Engine Div, FEV Motorentechnik GmbH AB The long time challenge for diesel engine manufacturers has been to reduce both particulate matter (PM) and NOx emissions simultaneously without sacrificing engine performance. One technique for reducing PM has been to inject air or oxygen-enriched air directly into the combustion chamber. Previous studies using the KIVA-3V computational fluid dynamics (CFD) model have shown benefits and the importance of the gas injection's characteristics on the technique's effectiveness in reducing emissions. Using a Caterpillar 3401E single cylinder engine, an experimental investigation has been conducted to demonstrate the effectiveness of an oxygen-enriched air injection system and fuel injection timing retard in reducing the NON and the PM emissions in terms of both the particulate size and concentration. The gaseous emissions were measured using a Pierburg AMA 2000 gaseous emissions bench which included a chemiluminescent analyzer for NOx volumetric measurements, non-dispersive infrared (NDIR) analyzer for CO and CO2 measurements, and a parametric fuel cell for O-2 measurements. PM emissions (i.e., soot particle concentration and size distribution) were measured using a TSI Model 3936 Scanning Mobility Particle Sizer (SMPS). The experimental observations regarding the effects of oxygen-enriched air injection on NOx and PM emissions were in accord with the previously reported results for late-cycle gas injection from a KIVA-3V model. The air injection technique additionally provided a low level of oxygen-enrichment during the compression cycle, with results similar to previous intake air oxygen-enrichment studies. A simultaneous reduction of NOx and particulates was demonstrated when the fuel injection timing characteristics were optimized in conjunction with the oxygen-enriched air injection. The experimental PM emissions were analyzed for number and size distributions and also found to be consistent with previously reported trends. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Longman, DE (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 22 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 0-7918-4206-1 PY 2006 BP 499 EP 506 PG 8 WC Engineering, Mechanical; Transportation Science & Technology SC Engineering; Transportation GA BFO17 UT WOS:000243399700052 ER PT B AU Macal, CM North, MJ AF Macal, Charles M. North, Michael J. GP IEEE TI Tutorial on agent-based modeling and simulation part 2: How to model with agents SO PROCEEDINGS OF THE 2006 WINTER SIMULATION CONFERENCE, VOLS 1-5 LA English DT Proceedings Paper CT 2006 Winter Simulation Conference CY DEC 03-06, 2006 CL Monterey, CA SP IEEE AB Agent-based modeling and simulation (ABMS) is a new approach to modeling systems comprised of interacting autonomous agents. ABMS promises to have far-reaching effects on the way that businesses use computers to support decision-making and researchers use electronic laboratories to do research. Some have gone so far as to contend that ABMS is a new way of doing science. Computational advances make possible a growing number of agent-based applications across many fields. Applications range from modeling agent behavior in the stock market and supply chains, to predicting the spread of epidemics and the threat of bio-warfare, from modeling the growth and decline of ancient civilizations to modeling the complexities of the human immune system, and many more. This tutorial describes the foundations of ABMS, identifies ABMS tool-kits and development methods illustrated through a supply chain example, and provides thoughts on the appropriate contexts for ABMS versus conventional modeling techniques. C1 [Macal, Charles M.; North, Michael J.] Argonne Natl Lab, Decis & Informat Sci Div, Ctr Complex Adapt Agent Syst Simulat, CAS2, Argonne, IL 60439 USA. RP Macal, CM (reprint author), Argonne Natl Lab, Decis & Informat Sci Div, Ctr Complex Adapt Agent Syst Simulat, CAS2, Argonne, IL 60439 USA. FU U.S. Department of Energy [W-31-109-ENG-38] FX The authors thank Averill Law for recent discussions on the relationship between agent modeling and conventional simulation. This work is sponsored by the U.S. Department of Energy under contract W-31-109-ENG-38. NR 30 TC 69 Z9 72 U1 1 U2 28 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0500-8 PY 2006 BP 73 EP 83 DI 10.1109/WSC.2006.323040 PG 11 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA BGE17 UT WOS:000246261200009 ER PT B AU Perumalla, KS AF Perumalla, Kalyan S. GP IEEE TI Parallel and distributed simulation: Traditional techniques and recent advances SO Proceedings of the 2006 Winter Simulation Conference, Vols 1-5 LA English DT Proceedings Paper CT 2006 Winter Simulation Conference CY DEC 03-06, 2006 CL Monterey, CA SP IEEE ID VIRTUAL TIME; SYSTEM; DESIGN AB This tutorial on parallel and distributed simulation systems reviews some of the traditional synchronization techniques and presents some recent advances. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Perumalla, KS (reprint author), Oak Ridge Natl Lab, 1 Bethel Valley Rd, Oak Ridge, TN 37831 USA. OI Perumalla, Kalyan/0000-0002-7458-0832 NR 47 TC 27 Z9 28 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0500-8 PY 2006 BP 84 EP 95 DI 10.1109/WSC.2006.323041 PG 12 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA BGE17 UT WOS:000246261200010 ER PT B AU Dudenhoeffer, DD Permann, MR Manic, M AF Dudenhoeffer, Donald D. Permann, May R. Manic, Milos GP IEEE TI CIMS: A FRAMEWORK FOR INFRASTRUCTURE INTERDEPENDENCY MODELING AND ANALYSIS SO PROCEEDINGS OF THE 2006 WINTER SIMULATION CONFERENCE, VOLS 1-5 LA English DT Proceedings Paper CT 2006 Winter Simulation Conference CY DEC 03-06, 2006 CL Monterey, CA SP IEEE AB Today's society relies greatly upon an array of complex national and international infrastructure networks, such as transportation, utilities, telecommunication, and even financial networks. While modeling and simulation tools have provided insight into the behavior of individual infrastructure networks, a far less understood area is that of the interrelationships among multiple infrastructure networks including the potential cascading effects that may result due to these interdependencies. This paper first describes infrastructure interdependencies, as well as presenting a formalization of interdependency types. Next the paper describes a modeling and simulation framework called CIMS (R) and the work that is being conducted at the Idaho National Laboratory (INL) to model and simulate infrastructure interdependencies and the complex behaviors that can result. C1 [Dudenhoeffer, Donald D.; Permann, May R.] Idaho Natl Lab, POB 1625, Idaho Falls, ID 83415 USA. [Manic, Milos] Univ Idho, Dept Comp Sci, Idaho Falls, ID 83402 USA. RP Dudenhoeffer, DD (reprint author), Idaho Natl Lab, POB 1625, Idaho Falls, ID 83415 USA. FU U. S. Department of Energy [DE-AC07-05ID14517] FX The CIMS (c) software was prepared by Battelle Energy Alliance, LLC under Contract No. DE-AC07-05ID14517 with the U. S. Department of Energy. The United States Government is granted for itself and others acting on its behalf a non-exclusive, paid-up, irrevocable worldwide license in this software to reproduce, prepare derivative works, and perform publicly and display publicly, by or on behalf of the Government. NR 10 TC 46 Z9 48 U1 1 U2 6 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0500-8 PY 2006 BP 478 EP + DI 10.1109/WSC.2006.323119 PG 2 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA BGE17 UT WOS:000246261201004 ER PT B AU Nicol, DM Tsang, R Ammerlahn, H Johnson, M AF Nicol, David M. Tsang, Rose Ammerlahn, Heidi Johnson, Michael GP IEEE TI Detection of nuclear material at border crossings using motion correlation SO PROCEEDINGS OF THE 2006 WINTER SIMULATION CONFERENCE, VOLS 1-5 LA English DT Proceedings Paper CT 2006 Winter Simulation Conference CY DEC 03-06, 2006 CL Monterey, CA SP IEEE AB This paper considers the problem that arises when a vehicle carrying nuclear material is detected approaching a border crossing. As quickly as possible, and with automation we wish to identify which vehicle among all those in the area is likely to be carrying the source. We show that if the border crossing area has technology for tracking the position of vehicles, we can correlate observed movements with observed changes in levels of detected radiation for as the vehicle carrying the material gets closer to the detector, the stronger will be the detected radiation. We use a simulation model that captures the stop-and-go dynamics of a border crossing area to evaluate our ideas, and find a highly successful technique that tracks which vehicles move just when detected radiation changes, coupled with fitting radiation intensity/distance observations to an inverse-square law. This method almost always isolates the sought vehicle just as soon as the minimum number of data observations is obtained. C1 [Nicol, David M.] Univ Illinois, Dept Elect & Comp Engn, 1406 W Green St, Urbana, IL 61801 USA. [Tsang, Rose; Ammerlahn, Heidi; Johnson, Michael] Sandia Natl Labs, Livermore, CA 94551 USA. RP Nicol, DM (reprint author), Univ Illinois, Dept Elect & Comp Engn, 1406 W Green St, Urbana, IL 61801 USA. FU DARPA [N66001-96-C-8530]; NSF [CCR-0209144]; Institute for Security Technology Studies, U.S. Department of Homeland Security [2000-DT-CX-K001]; Science and Technology Directorate FX This research was supported in part by DARPA Contract N66001-96-C-8530, and NSF Grant CCR-0209144. Accordingly, the U.S. Government retains a non-exclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for U.S. Government purposes. In addition, this research program is a part of the Institute for Security Technology Studies, supported under Award number 2000-DT-CX-K001 from the U.S. Department of Homeland Security, Science and Technology Directorate. NR 7 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0500-8 PY 2006 BP 536 EP + DI 10.1109/WSC.2006.323127 PG 3 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA BGE17 UT WOS:000246261201012 ER PT B AU Martinez-Moyano, IJ Rich, EH Conrad, SH Andersen, DF AF Martinez-Moyano, Ignacio J. Rich, Eliot H. Conrad, Stephen H. Andersen, David F. GP IEEE TI Modeling the emergence of insider threat vulnerabilities SO PROCEEDINGS OF THE 2006 WINTER SIMULATION CONFERENCE, VOLS 1-5 LA English DT Proceedings Paper CT 2006 Winter Simulation Conference CY DEC 03-06, 2006 CL Monterey, CA SP IEEE AB In this paper, we present insights generated by modeling the emergence of insider threat vulnerabilities in organizations. In our model, we integrate concepts from social judgment theory, signal detection theory, and the cognitive psychology of memory and belief formation. With this model, we investigate the emergence of vulnerabilities (especially that are insider-driven) in complex systems characterized by high levels of feedback complexity, multiple actors, and the presence of uncertainty in the judgment and decision processes. We use the system dynamics method of computer simulation to investigate the consequences caused by changes to the model's assumptions. We find that the emergence of vulnerability can be an endogenous process and that leverage points to reduce this vulnerability involve improvement in information acquisition, information management, and the training of personnel in judgment and decision-making techniques. C1 [Martinez-Moyano, Ignacio J.] Argonne Natl Lab, Decis & Risk Anal Grp, 9700 S Cass Ave, Argonne, IL 60439 USA. [Rich, Eliot H.] Univ Albany, Sch Business, Albany, NY 12222 USA. [Conrad, Stephen H.] Sandia Natl Labs, Albuquerque, NM USA. [Andersen, David F.] Univ Albany, Rockefeller Coll, Albany, NY 12222 USA. RP Martinez-Moyano, IJ (reprint author), Argonne Natl Lab, Decis & Risk Anal Grp, 9700 S Cass Ave, Argonne, IL 60439 USA. FU U.S. Department of Homeland Security FX This work was supported in part by the U.S. Department of Homeland Security. NR 19 TC 3 Z9 3 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0500-8 PY 2006 BP 562 EP + DI 10.1109/WSC.2006.323130 PG 3 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA BGE17 UT WOS:000246261201015 ER PT B AU Smith, VD Searles, DG Thompson, BM Cranwell, RM AF Smith, V. Devon Searles, Donald G. Thompson, Bruce M. Cranwell, Robert M. GP IEEE TI Sem: Enterprise modeling of JSF global sustainment SO PROCEEDINGS OF THE 2006 WINTER SIMULATION CONFERENCE, VOLS 1-5 LA English DT Proceedings Paper CT 2006 Winter Simulation Conference CY DEC 03-06, 2006 CL Monterey, CA SP IEEE AB The Joint Strike Fighter (JSF) Program is implementing a paradigm shift to a performance-based logistics environment for force sustainment. This approach produces the necessary levels of performance at a significantly reduced cost of ownership. The resulting logistics environment is multi-national, multi-echelon, and multi-service. The magnitude of the change in the support concept requires an enterprise-level model that can instill customer confidence in unproven alternatives to legacy approaches and capture investment/commitment to enable a profitable execution. The Support Enterprise Model (SEM) was developed by Lockheed Martin to provide a consistent/accurate global view for support of strategic decisions during design/implementation of a JSF global sustainment solution. SEM is a discrete event simulation that allows analysts to define operational/support environment, ascertain measures of effectiveness for performance/cost metrics, and characterize sensitivity to changes in Support System architecture, processes, and business approach as well as air vehicle reliability and maintainability characteristics. C1 [Smith, V. Devon; Searles, Donald G.] 101 Acad Blvd,POB 748,MZ 8814, Ft Worth, TX 76101 USA. [Thompson, Bruce M.; Cranwell, Robert M.] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Smith, VD (reprint author), 101 Acad Blvd,POB 748,MZ 8814, Ft Worth, TX 76101 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0500-8 PY 2006 BP 1324 EP + DI 10.1109/WSC.2006.323231 PG 3 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA BGE17 UT WOS:000246261202056 ER PT B AU Ruth, MF Vanderveen, KB Sa, TJ AF Ruth, Mark F. Vanderveen, Keith B. Sa, Timothy J. GP IEEE TI Use of federated object modeling to develop a macro-system model for the US department of energy's hydrogen program SO PROCEEDINGS OF THE 2006 WINTER SIMULATION CONFERENCE, VOLS 1-5 LA English DT Proceedings Paper CT 2006 Winter Simulation Conference CY DEC 03-06, 2006 CL Monterey, CA SP IEEE AB The U.S. Department of Energy (DOE) is working on technology that could change our transportation fuel from gasoline to hydrogen. To assist in that effort, we are developing a macro-system model (MSM) that will link existing or developmental component models together to analyze crosscutting hydrogen issues. The MSM uses a federated simulation framework that extends the High Level Architecture (HLA). In this initial phase, three existing models have been linked to analyze two primary issues. The first issue we will examine will be the combined price of hydrogen production and delivery and the second will be a comparison of energy requirements and air emissions for multiple hydrogen production / delivery pathways (i.e., hydrogen produced from different feedstocks and transported via different means). Future work will involve linking other models to allow us to better analyze transition issues and making the MSM available to the hydrogen analysis community. C1 [Ruth, Mark F.] Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. [Vanderveen, Keith B.; Sa, Timothy J.] Sandia Natl Labs, Livermore, CA 94550 USA. RP Ruth, MF (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. FU Midwest Research Institute [DE-AC36 99GO10337]; U.S. Department of Energy FX This work has been authored by an employee of the Midwest Research Institute under Contract No. DE-AC36 99GO10337 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non exclusive, paidup, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for United States Government purposes. NR 12 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0500-8 PY 2006 BP 1438 EP + DI 10.1109/WSC.2006.323245 PG 3 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA BGE17 UT WOS:000246261203009 ER PT B AU Perumalla, KS AF Perumalla, Kalyan S. GP IEEE TI A systems approach to scalable transportation network modeling SO Proceedings of the 2006 Winter Simulation Conference, Vols 1-5 LA English DT Proceedings Paper CT 2006 Winter Simulation Conference CY DEC 03-06, 2006 CL Monterey, CA SP IEEE ID SIMULATION AB Emerging needs in transportation network modeling and simulation are raising new challenges with respect to scalability of network size and vehicular traffic intensity, speed of simulation for simulation-based optimization, and fidelity of vehicular behavior for accurate capture of event phenomena. Parallel execution is warranted to sustain the required detail, size and speed. However, few parallel simulators exist for such applications, partly due to the challenges underlying their development. Moreover, many simulators are based on time-stepped models, which can be computationally inefficient for the purposes of modeling evacuation traffic. Here an approach is presented to designing a simulator with memory and speed efficiency as the goals from the outset, and, specifically, scalability via parallel execution. The design makes use of discrete event modeling techniques as well as parallel simulation methods. Our simulator, called SCATTER, is being developed, incorporating such design considerations. Preliminary performance results are presented on benchmark road networks, showing scalability to one million vehicles simulated on one processor. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Perumalla, KS (reprint author), Oak Ridge Natl Lab, 1 Bethel Valley Rd, Oak Ridge, TN 37831 USA. OI Perumalla, Kalyan/0000-0002-7458-0832 NR 11 TC 2 Z9 2 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0500-8 PY 2006 BP 1500 EP 1507 DI 10.1109/WSC.2006.322919 PG 8 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA BGE17 UT WOS:000246261203017 ER PT B AU Waupotitsch, R Eidenbenz, S Smith, JP Kroc, L AF Waupotitsch, Roman Eidenbenz, Stephan Smith, James P. Kroc, Lukas GP IEEE TI Multi-scale integrated information and teleconeaunications system (MIITS): First results from a large-scale end-to-end network simulator SO PROCEEDINGS OF THE 2006 WINTER SIMULATION CONFERENCE, VOLS 1-5 LA English DT Proceedings Paper CT 2006 Winter Simulation Conference CY DEC 03-06, 2006 CL Monterey, CA SP IEEE AB Performing realistic simulations of Internet packet traffic on a national or global level is a daunting task from both the modeling and the computational perspective. We present the MITTS (Multi-scale Integrated Information and Telecommunications System) tool that implements a novel approach to network simulation and report first scaling results from a realistic Internet scenario. MITTS' end-to-end approach to network simulation relies on modules for (i) accurate network topology and capacity representation, (ii) realistic communication session generation based on the activities of an agent population that is statistically equivalent to the population in a large metropolitan area, (iii) the actual scalable packet-level network simulation that is based on distributed event-driven technology, and (iv) analysis of large amounts of simulation output data. We present a sample simulation of a Los Angeles network as an intermediate step toward the vision of national-level simulation. C1 [Waupotitsch, Roman] Los Alamos Natl Lab, Decis Applicat Div, Mail Stop K557, Los Alamos, NM 87545 USA. [Eidenbenz, Stephan; Smith, James P.] Los Alamos Natl Lab, Comp Computat Sci, Los Alamos, NM 87545 USA. [Kroc, Lukas] Cornell Univ, Dept Comp Sci, Ithaca, NY 14853 USA. RP Waupotitsch, R (reprint author), Los Alamos Natl Lab, Decis Applicat Div, Mail Stop K557, Los Alamos, NM 87545 USA. NR 15 TC 6 Z9 6 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0500-8 PY 2006 BP 2132 EP + DI 10.1109/WSC.2006.323013 PG 3 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA BGE17 UT WOS:000246261204040 ER PT B AU Castillo, V AF Castillo, Victor GP IEEE TI Parallel simulations of manufacturing processing using simpy, a python-based discrete event simulation tool SO Proceedings of the 2006 Winter Simulation Conference, Vols 1-5 LA English DT Proceedings Paper CT 2006 Winter Simulation Conference CY DEC 03-06, 2006 CL Monterey, CA SP IEEE C1 Lawrence Livermore Natl Lab, Elect Engn Technol Div, Livermore, CA 94550 USA. RP Castillo, V (reprint author), Lawrence Livermore Natl Lab, Elect Engn Technol Div, Livermore, CA 94550 USA. NR 0 TC 2 Z9 2 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0500-8 PY 2006 BP 2294 EP 2294 DI 10.1109/WSC.2006.323064 PG 1 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA BGE17 UT WOS:000246261204070 ER PT B AU Harris, JR Anaya, RM Blackfield, D Chen, YJ Falabella, S Hawkins, S Holmes, C Paul, AC Sampayan, S Sanders, DM Wang, L Watson, JA Caporaso, GJ Krogh, M AF Harris, J. R. Anaya, R. M. Blackfield, D. Chen, Y. -J. Falabella, S. Hawkins, S. Holmes, C. Paul, A. C. Sampayan, S. Sanders, D. M. Wang, L. Watson, J. A. Caporaso, G. J. Krogh, M. GP IEEE TI High-gradient insulators SO PROCEEDINGS OF THE 27TH INTERNATIONAL POWER MODULATOR SYMPOSIUM AND 2006 HIGH VOLTAGE WORKSHOPS LA English DT Proceedings Paper CT 27th International Power Modulator Symposium/2006 High Voltage Workshops CY MAY 14-18, 2006 CL Washington, DC SP IEEE Dielect, Elect Insulat Soc, IEEE Elect Devices Soc, IEEE Nucl & Plasma Sci Soc, DEIS AB High voltage systems operated in vacuum require insulating materials to maintain spacing between conductors held at different potentials. Traditional vacuum insulators consist of a single material, often machined with a 45 degrees angle to suppress surface flashover. However, insulating structures composed of alternating layers of dielectric and metal can also be built, and have been experimentally shown to have higher breakdown voltages than conventional insulators. These "high-gradient insulators" allow closer spacing of components in vacuum, and therefore; have application to a wide range of high-voltage vacuum systems where compact size is important. This paper describes ongoing simulations and experimental work on these structures, as well as the theoretical understanding driving this research. C1 [Harris, J. R.; Anaya, R. M.; Blackfield, D.; Chen, Y. -J.; Falabella, S.; Hawkins, S.; Holmes, C.; Paul, A. C.; Sampayan, S.; Sanders, D. M.; Wang, L.; Watson, J. A.; Caporaso, G. J.; Krogh, M.] Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Harris, JR (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. FU Nuclear Energy Development Project of State Administration of Science, Technology and Industry for National Defence; National Natural Science Foundation of China [11035004]; CAEP [2013A0402018] FX This work was supported in part by the Nuclear Energy Development Project of State Administration of Science, Technology and Industry for National Defence, in part by the National Natural Science Foundation of China under Grant 11035004 and in part by CAEP under Project 2013A0402018. NR 18 TC 1 Z9 5 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0018-8 PY 2006 BP 55 EP + PG 2 WC Engineering, Electrical & Electronic SC Engineering GA BGF53 UT WOS:000246445300013 ER PT B AU Cours, A AF Cours, Alex GP IEEE TI Partial discharge tests and characterization of the advanced photon source linac modulator cables SO PROCEEDINGS OF THE 27TH INTERNATIONAL POWER MODULATOR SYMPOSIUM AND 2006 HIGH VOLTAGE WORKSHOPS LA English DT Proceedings Paper CT 27th International Power Modulator Symposium/2006 High Voltage Workshops CY MAY 14-18, 2006 CL Washington, DC SP IEEE Dielect, Elect Insulat Soc, IEEE Elect Devices Soc, IEEE Nucl & Plasma Sci Soc, DEIS AB The Advanced Photon Source (APS) linac modulators are PFN-type pulsers with switch-mode charging power supplies (PSs). The PS and the PFN are connected to each other by 15 feet of 100-kV x-ray cable, with the PFN end of the cable terminated with a connector that was confirmed partial-discharge (PD)-free up to 38 kV ac (53.5 kV peak). Another end of the cable is terminated with a connector that was designed by the PS manufacturer and cannot easily be replaced with another type of connector, since part of it is located inside the densely packed PS. PD tests of the cables with this type of connector show that the PD inception voltages (PDIVs) in different cables turn out to be located within a wide voltage range: 21 to 27 kV ac that corresponds to 29 to 38 kV peak. In order to evaluate the insulation condition of the modulator cables, detect insulation deterioration, and ensure failure-preventing equipment maintenance, over the last two years the PDIVs of all high-voltage (HV) cables in use in the modulators have been tested about every three and a half months. Before the tests, all cables were removed from the equipment, carefully cleaned, inspected, and regreased. The tests were performed using a 40-kV PD detector. The test results show that: 1) The PDIVs remain almost unchanged in all tested cables. 2) From test to test, the PDIV of any particular cable may slightly oscillate around some average value. This possibly depends on the connector regreasing technique. 3)There is no direct evidence of cable insulation deterioration during more than two years of operation under voltage higher than the PD inception level. C1 [Cours, Alex] Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RP Cours, A (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM cours@aps.anl.gov FU U.S. Department of Energy, Office of Basic Energy Sciences [W-31-109-ENG-38] FX Work supported by U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0018-8 PY 2006 BP 124 EP + PG 2 WC Engineering, Electrical & Electronic SC Engineering GA BGF53 UT WOS:000246445300029 ER PT B AU Glover, SF Zutavern, FJ Reed, KW Swalby, ME Mar, A Horry, ML White, FE Gruner, FR AF Glover, S. F. Zutavern, F. J. Reed, K. W. Swalby, M. E. Mar, A. Horry, M. L. White, F. E. Gruner, F. R. GP IEEE TI Fiber-optic controlled PCSS triggers for high voltage pulsed power switches SO PROCEEDINGS OF THE 27TH INTERNATIONAL POWER MODULATOR SYMPOSIUM AND 2006 HIGH VOLTAGE WORKSHOPS LA English DT Proceedings Paper CT 27th International Power Modulator Symposium/2006 High Voltage Workshops CY MAY 14-18, 2006 CL Washington, DC SP IEEE Dielect, Elect Insulat Soc, IEEE Elect Devices Soc, IEEE Nucl & Plasma Sci Soc, DEIS AB Pulsed power systems are continually being designed to increase performance and flexibility in order to meet new needs. Drivers for fusion, equation of state research and radiography are just a few of the scientific areas driving accelerated pulsed power development. Improved system timing and jitter requirements, along with pulse shaping capabilities through independent timing of individual switches, are placing higher demands upon high voltage (HV) switch performance, triggering system performance and cost. Conventional trigger systems require high voltage trigger cables or line-of-sight optics that complicate design, demand space, require extensive maintenance, and significantly impact system cost. With electrical triggers, large diameter, high voltage transmission line cables must be fed through high field regions. With optical triggers, line-of-sight optics must focus high energy laser beams to the interior of the switches with clean, rigidly-mounted, shock-withstanding optics. This paper reports on progress in the development of fiber optically triggered photoconductive semiconductor switches (PCSS) for triggering high voltage pulsed power switches with improved precision. This technology can eliminate the need for large-diameter trigger cables and line-of-sight optics. It also has the potential of significantly reducing the cost of trigger generation systems. It has the potential to improve the performance of prime power switches, diverters, and diagnostics because of the low-jitter sub-nanosecond rise times. Test results will be presented that demonstrate sub-nanosecond jitter from a PCSS, less than 1.2 nanoseconds of jitter from a commercial trigatron switch triggered by PCSS, and the performance analysis of a 200kV class switch triggered by a PCSS based triggering system. This work is a step toward the creation of a reliable self-contained PCSS-based trigger generator that can be physically located on a high voltage switch, allowing the triggering hardware to float. The only connection to the trigger system will be a low energy optical fiber, thereby eliminating the need for HV cables traversing high potential fields or for line-of-sight-optics. C1 [Glover, S. F.; Zutavern, F. J.; Reed, K. W.; Swalby, M. E.; Mar, A.; Horry, M. L.] Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. [White, F. E.] Ktech Corp Inc, Albuquerque, NM 87123 USA. [Gruner, F. R.] Kinetech LLC, Albuquerque, NM 87123 USA. RP Glover, SF (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. FU Sandia Corporation for the United States Department of Energy [DEAC04-94AL85000] FX Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation for the United States Department of Energy under Contract DEAC04-94AL85000. NR 7 TC 0 Z9 3 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0018-8 PY 2006 BP 192 EP + PG 2 WC Engineering, Electrical & Electronic SC Engineering GA BGF53 UT WOS:000246445300046 ER PT B AU LeChien, KR Gahl, JM AF LeChien, Keith R. Gahl, John M. GP IEEE TI Viable options for reducing impedance in a 2.5 MV multichanneling, multigap, SF6 Gas switch SO PROCEEDINGS OF THE 27TH INTERNATIONAL POWER MODULATOR SYMPOSIUM AND 2006 HIGH VOLTAGE WORKSHOPS LA English DT Proceedings Paper CT 27th International Power Modulator Symposium/2006 High Voltage Workshops CY MAY 14-18, 2006 CL Washington, DC SP IEEE Dielect, Elect Insulat Soc, IEEE Elect Devices Soc, IEEE Nucl & Plasma Sci Soc, DEIS AB An investigation was conducted into factors that effect impedance for a 2.5 MV gas switch. The switch studied was Rimfire, the workhorse gas switch topology for many of Sandia's large accelerators. The geometry of the switch investigated consists of multiple self-break gaps in series with a laser triggered main gap. The switch is situated within a coaxial-like ground return structure. In this geometry there are three avenues that are theoretically possible for reducing switch impedance. They are 1) increasing the number of parallel current sharing channels (multichanneling), 2) decreasing the ratio of radii of the outer to inner conductors, and/or 3) decreasing the length. It was experimentally determined what effects the first two factors have on switch impedance and the results are presented in this work. It was discovered that multichanneling and radii ratio have substantially lesser effects on impedance, when compared to the theoretical effects of a reduction in switch length. This leaves reduction in length as the only remaining significant viable option for reduction of impedance in megavolt multigap switches, which has substantial consequences for the future design of multigap switches. C1 [LeChien, Keith R.] Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. [Gahl, John M.] Univ Missouri, Columbia, MO USA. RP LeChien, KR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. FU [DE-AC04-94AL85000] FX Sandia is a multiprogram laboratory operated by Sandia Corporation, a switch designs. Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. NR 16 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0018-8 PY 2006 BP 197 EP + PG 2 WC Engineering, Electrical & Electronic SC Engineering GA BGF53 UT WOS:000246445300048 ER PT B AU Sullivan, JS Stanley, JR AF Sullivan, J. S. Stanley, J. R. GP IEEE TI 6H-SiC photoconductive switches triggered at below bandgap wavelengths SO PROCEEDINGS OF THE 27TH INTERNATIONAL POWER MODULATOR SYMPOSIUM AND 2006 HIGH VOLTAGE WORKSHOPS LA English DT Proceedings Paper CT 27th International Power Modulator Symposium/2006 High Voltage Workshops CY MAY 14-18, 2006 CL Washington, DC SP IEEE Dielect, Elect Insulat Soc, IEEE Elect Devices Soc, IEEE Nucl & Plasma Sci Soc, DEIS ID DEVICES AB Semi-insulating Silicon Carbide (SiC) is an attractive material to use to construct high voltage, compact, photoconducting semiconductor switches (PCSS) due to its large bandgap, high critical electric field strength, high electron saturation velocity, and high thermal conductivity. The critical field strength of 3 MV/cm of 6H-SiC makes it particularly attractive for compact, high voltage, fast switching applications such as a Dielectric Wall Accelerator (DWA). To realize the benefits of the high bulk electric field strength of SiC and diffuse switch current, carriers must be excited throughout the bulk of the photo switch. Photoconducting switches with opposing electrodes were fabricated on "a" plane, Vanadium compensated, semi-insulating, 6H-SiC substrates. The PCSS devices were switched by optically exciting deep extrinsic levels lying within the 6H-SiC bandgap. The SiC photoswitches were tested up to a bias voltage of 11000 V with a corresponding peak current of 150 A. The 6H-SiC substrates withstood average electric fields up to 27 MV/m. Minimum PCCS dynamic resistances of 2 and 10 Ohms were obtained with 13 mJ optical pulses at 532 and 1064 nm wavelengths, respectively. C1 [Sullivan, J. S.; Stanley, J. R.] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Sullivan, JS (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. FU U.S Department of Energy; University of California; Lawrence Livermore Laboratory [W-7405-Eng-48] FX This work was performed under the auspices of the U.S Department of Energy by the University of California, Lawrence Livermore Laboratory under contract W-7405-Eng-48. NR 4 TC 4 Z9 4 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0018-8 PY 2006 BP 215 EP + PG 2 WC Engineering, Electrical & Electronic SC Engineering GA BGF53 UT WOS:000246445300052 ER PT B AU Sanders, D Sampayan, S Caporaso, G Rhodes, M Watson, J Slenes, K Jacquina, J De La Fuenta, R Thurmond, L AF Sanders, D. Sampayan, S. Caporaso, G. Rhodes, M. Watson, J. Slenes, K. Jacquina, J. De La Fuenta, R. Thurmond, L. GP IEEE TI Development of a low loss, high dielectric strength microwave substrate SO PROCEEDINGS OF THE 27TH INTERNATIONAL POWER MODULATOR SYMPOSIUM AND 2006 HIGH VOLTAGE WORKSHOPS LA English DT Proceedings Paper CT 27th International Power Modulator Symposium/2006 High Voltage Workshops CY MAY 14-18, 2006 CL Washington, DC SP IEEE Dielect, Elect Insulat Soc, IEEE Elect Devices Soc, IEEE Nucl & Plasma Sci Soc, DEIS AB This work describes a comparison of two candidate materials for pulse forming line fabrication with respect to bulk dielectric breakdown, frequency response of relative permittivity, and dielectric loss. One material is a commercially available microwave substrate material that can be procured in sheet form without a high voltage specification, while the other is a newly developed material that also comes in sheet form that can also be cast between the electrodes. C1 [Sanders, D.; Sampayan, S.; Caporaso, G.; Rhodes, M.; Watson, J.] Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Sanders, D (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. FU U.S. Department of Energy by University of California; Lawrence Livermore National Laboratory [W-7405-Eng-48] FX This work was performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0018-8 PY 2006 BP 291 EP + PG 2 WC Engineering, Electrical & Electronic SC Engineering GA BGF53 UT WOS:000246445300072 ER PT B AU Zhang, W Eng, W Pai, C Sandberg, J Tan, Y Tian, Y AF Zhang, W. Eng, W. Pai, C. Sandberg, J. Tan, Y. Tian, Y. GP IEEE TI A simplified model for parameter estimation and circuit analysis of inductive-adder modulator SO PROCEEDINGS OF THE 27TH INTERNATIONAL POWER MODULATOR SYMPOSIUM AND 2006 HIGH VOLTAGE WORKSHOPS LA English DT Proceedings Paper CT 27th International Power Modulator Symposium/2006 High Voltage Workshops CY MAY 14-18, 2006 CL Washington, DC SP IEEE Dielect, Elect Insulat Soc, IEEE Elect Devices Soc, IEEE Nucl & Plasma Sci Soc, DEIS AB In this paper, we propose a simplified model for easy estimation of design parameters and quick analysis of inductive adder modulators. Analytical method is used to deduct the simplified circuit model. This model offers an easy way to understand the behavior of the inductive-adder modulator circuits and provides designers a helpful tool to estimate critical parameters such as pulse rise time, system impedance, number of adder stages, etc. Computer simulations demonstrate that parameter estimation based on simplified circuit model is fairly accurate as compared to original circuit. Furthermore, this approach can be used in the early stages of system development to assist the feasibility study of the project and to aid geometry selection and parameter selection of critical components. C1 [Zhang, W.; Eng, W.; Pai, C.; Sandberg, J.; Tan, Y.; Tian, Y.] Brookhaven Natl Lab, Upton, NY 11973 USA. RP Zhang, W (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. FU U.S. Department of Energy FX Work performed under auspices of U.S. Department of Energy. NR 5 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0018-8 PY 2006 BP 338 EP + PG 2 WC Engineering, Electrical & Electronic SC Engineering GA BGF53 UT WOS:000246445300084 ER PT B AU Dale, GE Kirbie, HC AF Dale, G. E. Kirbie, H. C. GP IEEE TI Power flow management in a diode-directed solid-state Marx modulator SO PROCEEDINGS OF THE 27TH INTERNATIONAL POWER MODULATOR SYMPOSIUM AND 2006 HIGH VOLTAGE WORKSHOPS LA English DT Proceedings Paper CT 27th International Power Modulator Symposium/2006 High Voltage Workshops CY MAY 14-18, 2006 CL Washington, DC SP IEEE Dielect, Elect Insulat Soc, IEEE Elect Devices Soc, IEEE Nucl & Plasma Sci Soc, DEIS AB The increasing capability of solid-state components has resulted in their expanded use in high-power modulators. One concern in using solid-state switches in high-power modulators is the vulnerability of these switches to over-voltage transients. Protecting the switches is one of the many design challenges of solid-state modulators. Diode-directed Marx modulators have an ability to protect solid-state switches from over-voltage transients by routing the transient energy around the switches and returning it to the stage capacitors. The inherent switch protection capability of a diode-directed Marx modulator is described in this paper and experimental results are shown. C1 [Dale, G. E.; Kirbie, H. C.] Los Alamos Natl Lab, POB 1663,Mail Stop J-570, Los Alamos, NM 87544 USA. RP Dale, GE (reprint author), Los Alamos Natl Lab, POB 1663,Mail Stop J-570, Los Alamos, NM 87544 USA. RI Dale, Gregory/A-9419-2009 FU Los Alamos National Laboratory under US DOE [W-7405-ENG-36] FX Work sponsored by Los Alamos National Laboratory under US DOE contract W-7405-ENG-36 NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0018-8 PY 2006 BP 352 EP + PG 2 WC Engineering, Electrical & Electronic SC Engineering GA BGF53 UT WOS:000246445300089 ER PT B AU Sampayan, S Caporaso, G Chen, YJ Guethlein, G Harris, J Hawkins, S Holmes, C Krogh, M Nelson, S Nunnally, W Poole, B Rhodes, M Sanders, D Slenes, K Sullivan, J Wang, L Watson, J AF Sampayan, S. Caporaso, G. Chen, Y-J. Guethlein, G. Harris, J. Hawkins, S. Holmes, C. Krogh, M. Nelson, S. Nunnally, W. Poole, B. Rhodes, M. Sanders, D. Slenes, K. Sullivan, J. Wang, L. Watson, J. GP IEEE TI Development of compact pulsed power for the dielectric wall accelerator (DWA) SO PROCEEDINGS OF THE 27TH INTERNATIONAL POWER MODULATOR SYMPOSIUM AND 2006 HIGH VOLTAGE WORKSHOPS LA English DT Proceedings Paper CT 27th International Power Modulator Symposium/2006 High Voltage Workshops CY MAY 14-18, 2006 CL Washington, DC SP IEEE Dielect, Elect Insulat Soc, IEEE Elect Devices Soc, IEEE Nucl & Plasma Sci Soc, DEIS AB We are developing compact pulsed power systems for various defense missions. Although the system is primarily intended for pulsed radiography, its modularity makes it well suited for compact neutron sources for explosives detection and as an HPM driver for various DOD missions. To date, we have performed extensive research at the component level and are now pursuing the integration of the technology into a single accelerator cell. Cost is <$0.50/volt. As part of this effort, we are also pursuing advanced development of high specific energy dielectrics (> 10J/cm(3)), specialized transmission line designs, HGI insulator technology, multi-gap low jitter (< 1 ns) switches, and high voltage SiC photoconductive switching. We detail the progress of our overall research to date, recent high voltage test results, and the integration concept into a compact accelerator cell. C1 [Sampayan, S.; Caporaso, G.; Chen, Y-J.; Guethlein, G.; Harris, J.; Hawkins, S.; Holmes, C.; Krogh, M.; Nelson, S.; Nunnally, W.; Poole, B.; Rhodes, M.; Sanders, D.; Slenes, K.; Sullivan, J.; Wang, L.; Watson, J.] Lawrence Livermore Natl Lab, Beam Res Program, POB 808,L-645, Livermore, CA 94551 USA. [Nunnally, W.] Univ Missouri, Columbia, MO 65205 USA. [Slenes, K.] Acad Pkway North, Albuquerque, NM 87109 USA. RP Sampayan, S (reprint author), Lawrence Livermore Natl Lab, Beam Res Program, POB 808,L-645, Livermore, CA 94551 USA. FU U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory [W-7405-Eng-48] FX This work was performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48. NR 6 TC 0 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0018-8 PY 2006 BP 411 EP + PG 2 WC Engineering, Electrical & Electronic SC Engineering GA BGF53 UT WOS:000246445300103 ER PT B AU Rhodes, M Sampayan, S Watson, J Caporaso, G AF Rhodes, Mark Sampayan, Steve Watson, Jim Caporaso, George GP IEEE TI Oil-switched planar blumlein pulse generators for dielectric wall accelerators SO Proceedings of the 27th International Power Modulator Symposium and 2006 High Voltage Workshops LA English DT Proceedings Paper CT 27th International Power Modulator Symposium/2006 High Voltage Workshops CY MAY 14-18, 2006 CL Washington, DC SP IEEE Dielect, Elect Insulat Soc, IEEE Elect Devices Soc, IEEE Nucl & Plasma Sci Soc, DEIS AB We are developing oil-switched, planar-Blumlein pulse-generators for use in high-gradient dielectric-wall accelerators (DWA). This technology is applicable to a variety of applications including both proton and electron accelerators. In our designs, simple spark-gap switches are very tightly integrated to the ends of solid-insulated planar-Blumlein pulse forming lines. We can operate the switches with either pressurized gas or liquid (oil). By using oil as the switching medium, we have eliminated the requirement for a pressure interface around the switch. We immerse the entire assembly including the switch region in oil. In gas switches, switch-gap and pressure are the free parameters to set the operating voltage. With oil switches, the adjustment parameters are gap and charging time. We have built a single-stage prototype with Mylar/Oil insulation that generates a 5-ns pulse with < 1-ns risetime. To date, we have achieved an operating gradient of 38 MV/m with a goal of 50 MV/m into a matched load using 50 ns pulse-charge time. We operate the switch in self-break mode. For multi-stage versions, we plan on adding triggers to the switches. We present our experimental design and most recent results. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Rhodes, M (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0018-8 PY 2006 BP 415 EP 418 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BGF53 UT WOS:000246445300104 ER PT B AU Leyh, GE AF Leyh, G. E. GP IEEE TI The Marx modulator development program for the international linear collider SO Proceedings of the 27th International Power Modulator Symposium and 2006 High Voltage Workshops LA English DT Proceedings Paper CT 27th International Power Modulator Symposium/2006 High Voltage Workshops CY MAY 14-18, 2006 CL Washington, DC SP IEEE Dielect, Elect Insulat Soc, IEEE Elect Devices Soc, IEEE Nucl & Plasma Sci Soc, DEIS AB The ILC Marx Modulator Development Program at SLAC is working towards developing a full-scale ILC Marx 'Reference Design' modulator prototype, with the goal of significantly reducing the size and cost of the ILC modulator, while improving overall modulator efficiency and availability. The ILC Reference Design prototype will provide a proof-of-concept model to industry in advance of Phase II SBIR funding, and also allow operation of the new 10MW L-Band Klystron prototypes immediately upon their arrival at SLAC. C1 Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. RP Leyh, GE (reprint author), Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 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 BN 978-1-4244-0018-8 PY 2006 BP 423 EP 426 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BGF53 UT WOS:000246445300106 ER PT B AU Anderson, DE Hicks, J Wezensky, M Baca, D Reass, W AF Anderson, D. E. Hicks, J. Wezensky, M. Baca, D. Reass, W. GP IEEE TI Operational performance of the spallation neutron source high voltage converter modulator and system enhancements SO PROCEEDINGS OF THE 27TH INTERNATIONAL POWER MODULATOR SYMPOSIUM AND 2006 HIGH VOLTAGE WORKSHOPS LA English DT Proceedings Paper CT 27th International Power Modulator Symposium/2006 High Voltage Workshops CY MAY 14-18, 2006 CL Washington, DC SP IEEE Dielect, Elect Insulat Soc, IEEE Elect Devices Soc, IEEE Nucl & Plasma Sci Soc, DEIS AB The first-gene ration high-frequency switching megawatt-class High Voltage Converter Modulators (HVCM) developed by Los Alamos National Laboratory for the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory have been installed and are now operational. Each unit is capable of delivering pulses up to 11 MW peak, 1 MW average power at voltages up to 140 kV to drive klystron(s) rated up to 5 MW. To date, three variations of the basic design have been installed, each optimized to deliver power to a specific klystron load configuration, for a total of fifteen (15) units installed and operational at the SNS. The units have been operated 24/7 to support successful commissioning of the SNS accelerator. Design improvements, with the primary intention of improving system reliability and availability, have been under development since the initial installation of the HVCM units. This paper will examine HVCM reliability operational data of well over 50,000 operational hours, failure modes, and modifications and improvements performed and planned to increase the overall system availability. We will focus on enhancements designed to allow for increased average power operation, as well as discuss development programs underway to provide active component protection. C1 [Anderson, D. E.; Hicks, J.; Wezensky, M.] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. [Baca, D.; Reass, W.] Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Anderson, DE (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 3 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0018-8 PY 2006 BP 427 EP + PG 2 WC Engineering, Electrical & Electronic SC Engineering GA BGF53 UT WOS:000246445300107 ER PT B AU Woodworth, JR Molina, I Nelson, D Maenchen, J Sarkisov, G Blickem, J Starbird, R Wilkins, F De Valde, DV Johnson, DL AF Woodworth, Joseph R. Molina, Isidro Nelson, Dan Maenchen, John Sarkisov, Gennady Blickem, James Starbird, Robert Wilkins, Frank De Valde, David Van Johnson, David L. GP IEEE TI Green-laser-triggered water switching at 1.6 MegaVolts SO PROCEEDINGS OF THE 27TH INTERNATIONAL POWER MODULATOR SYMPOSIUM AND 2006 HIGH VOLTAGE WORKSHOPS LA English DT Proceedings Paper CT 27th International Power Modulator Symposium/2006 High Voltage Workshops CY MAY 14-18, 2006 CL Washington, DC SP IEEE Dielect, Elect Insulat Soc, IEEE Elect Devices Soc, IEEE Nucl & Plasma Sci Soc, DEIS AB Multiple water switches are used in the self-breaking mode in many large pulsed power systems. We are studying laser-triggering of water switches at voltages of up to 1.6 MV to see whether we can lower the command jitter of water switches. We have previously reported studies of 170-kV water switching with command jitters as low as +/- 2 ns. Our experiments are performed on a water switch in the middle of a 1.8-meter long 7.8-Ohm coaxial water line that is directly charged by a 65-kJ Marx generator. The zero-to-peak risetime of the sinusoidal pulse impressed across the water switch is similar to 350 ns. To trigger the switch, we transport a green laser beam (0.4 J, 7-ns pulsewidth) radially inward through the water of the coaxial line to a box inside the inner coax line. There, the laser beam is turned 90 degrees and focused through a hole in one electrode to a breakdown arc in the water between the switch electrodes. Best results, of +/- 8.3 ns jitter and 100 ns delay at 60% of the self-break voltage, have been achieved using an axicon lens to focus the beam to a long narrow chain of point breakdowns between the switch electrodes. C1 [Woodworth, Joseph R.; Molina, Isidro; Nelson, Dan; Maenchen, John] Sandia Natl Labs, POB 5800,MS 1192, Albuquerque, NM 87185 USA. [Sarkisov, Gennady; Blickem, James] Ktech Corp Inc, Albuquerque, NM 87123 USA. [Starbird, Robert; Wilkins, Frank] Bechtel Nevada, Las Vegas, NV 89193 USA. [De Valde, David Van] EG&G Tech Serv, Albuquerque, NM 87119 USA. [Johnson, David L.] L3 Commun Pulse Sci, San Leandro, CA 94577 USA. RP Woodworth, JR (reprint author), Sandia Natl Labs, POB 5800,MS 1192, Albuquerque, NM 87185 USA. FU United States Department of Energy's Department of National Nuclear Security Agency [DE-AC04-94AL85000] FX Sandia is a multiprogram Laboratory operated by Sandia Corporation, a Lockheed Martin company for the United States Department of Energys Department of National Nuclear Security Agency, under contract DE -AC04- 94AL85000. NR 9 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0018-8 PY 2006 BP 435 EP + PG 2 WC Engineering, Electrical & Electronic SC Engineering GA BGF53 UT WOS:000246445300109 ER PT B AU Rust, K Tang, J Plum, M AF Rust, Ken Tang, Johnny Plum, Mike GP IEEE TI SNS* ring extraction kicker system SO PROCEEDINGS OF THE 27TH INTERNATIONAL POWER MODULATOR SYMPOSIUM AND 2006 HIGH VOLTAGE WORKSHOPS LA English DT Proceedings Paper CT 27th International Power Modulator Symposium/2006 High Voltage Workshops CY MAY 14-18, 2006 CL Washington, DC SP IEEE Dielect, Elect Insulat Soc, IEEE Elect Devices Soc, IEEE Nucl & Plasma Sci Soc, DEIS AB The Spallation Neutron Source (SNS) has recently completed the commissioning of its 1.0 GeV proton storage ring, which included the Ring Extraction Kicker System. This extraction system is comprised of fourteen high-voltage Blumlein-configured pulse-forming networks switched by fourteen thyratrons. The system also includes fourteen Blumlein control racks, which provide a high-voltage source, monitoring of interlocks, and signal conditioning to the system control racks. The four-system control racks are for adjusting timing and monitoring of the charge voltages and current pulses at the kicker magnets. The kicker system is then controlled by EPICS, the accelerator's control system. The kickers were designed at Brookhaven National Laboratory [1] (BNL), and built to print by Applied Power Systems, Inc., (APS), of Hicksville, NY. The hardware and software utilized and the commissioning results of the fourteen Blumlein kickers will be presented. C1 [Rust, Ken; Tang, Johnny; Plum, Mike] Oak Ridge Natl Lab, SNS ASD, Oak Ridge, TN 37831 USA. RP Rust, K (reprint author), Oak Ridge Natl Lab, SNS ASD, Oak Ridge, TN 37831 USA. FU U.S. Department of Energy [DE-AC05-00OR22725] FX SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. SNS is a partnership of six national laboratories: Argonne, Brookhaven, Jefferson, Lawrence Berkeley, Los Alamos and Oak Ridge. NR 3 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0018-8 PY 2006 BP 460 EP + PG 2 WC Engineering, Electrical & Electronic SC Engineering GA BGF53 UT WOS:000246445300115 ER PT B AU Bliss, DE Bloomquist, DD Harjes, HC Lehr, JM Long, FW Maenchen, JE McDaniel, DH Mckee, GR Savage, ME Smith, DL Struve, KW Weed, JW Weinbrecht, EA Woodworth, JR Johnson, DL Corley, JP AF Bliss, David E. Bloomquist, Douglas D. Harjes, Henry C. Lehr, Jane M. Long, Finis W. Maenchen, John E. McDaniel, Dillon H. McKee, G. Randall Savage, Mark E. Smith, David L. Struve, Kenneth W. Weed, John W. Weinbrecht, Edward A. Woodworth, Joseph R. Johnson, David L. Corley, John P. GP IEEE TI The ZR final design pulsed power performance expectations SO PROCEEDINGS OF THE 27TH INTERNATIONAL POWER MODULATOR SYMPOSIUM AND 2006 HIGH VOLTAGE WORKSHOPS LA English DT Proceedings Paper CT 27th International Power Modulator Symposium/2006 High Voltage Workshops CY MAY 14-18, 2006 CL Washington, DC SP IEEE Dielect, Elect Insulat Soc, IEEE Elect Devices Soc, IEEE Nucl & Plasma Sci Soc, DEIS C1 [Bliss, David E.; Bloomquist, Douglas D.; Harjes, Henry C.; Lehr, Jane M.; Long, Finis W.; Maenchen, John E.; McDaniel, Dillon H.; McKee, G. Randall; Savage, Mark E.; Smith, David L.; Struve, Kenneth W.; Weed, John W.; Weinbrecht, Edward A.; Woodworth, Joseph R.] Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. [Johnson, David L.] Titan Pulse Sci Div, San Leandro, CA USA. [Corley, John P.] Ktech Corp Inc, Albuquerque, NM USA. RP Bliss, DE (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. FU United States Department of Energy's National Nuclear Security [DE-AC04-94AL85000] FX Sandia is a multi-program aboratory operated by Sandia Corporation, a Lockheed Martin company, for the United States Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0018-8 PY 2006 BP 582 EP 582 PG 1 WC Engineering, Electrical & Electronic SC Engineering GA BGF53 UT WOS:000246445300150 ER PT S AU Krstic, M Siranosian, AA Smyshlyaev, A Bement, M AF Krstic, Miroslav Siranosian, Antranik A. Smyshlyaev, Andrey Bement, Matt GP IEEE TI Backstepping boundary controllers and observers for the slender Timoshenko beam: Part II - Stability and simulations SO PROCEEDINGS OF THE 45TH IEEE CONFERENCE ON DECISION AND CONTROL, VOLS 1-14 SE IEEE Conference on Decision and Control LA English DT Proceedings Paper CT 45th IEEE Conference on Decision and Control CY DEC 13-15, 2006 CL San Diego, CA SP IEEE AB We present the stability analysis and numerical results for our controller and observer designs for the slender Timoshenko beam with Kelvin-Voigt (internal material) damping. Our designs, introduced in a companion ACC '06 paper, use a combination of classical "damping boundary feedback" ideas with backstepping. The main advantage of our techniques over the previous boundary damping results is that they apply to the readily implementable "anti-collocated" architecture, which uses actuation only at the beam's base and sensing only at the beam's tip. C1 [Krstic, Miroslav; Siranosian, Antranik A.; Smyshlyaev, Andrey] Univ Calif San Diego, Dept Mech & Aerosp Engn, San Diego, CA 92103 USA. [Bement, Matt] Engn Sci & Applicat Div, Los Alamos Natl Lab, Los Alamos, NM USA. RP Krstic, M (reprint author), Univ Calif San Diego, Dept Mech & Aerosp Engn, San Diego, CA 92103 USA. EM krstic@ucsd.edu NR 13 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0743-1546 BN 978-1-4244-0170-3 J9 IEEE DECIS CONTR P PY 2006 BP 3941 EP + PG 2 WC Automation & Control Systems; Engineering, Electrical & Electronic; Operations Research & Management Science SC Automation & Control Systems; Engineering; Operations Research & Management Science GA BHD08 UT WOS:000252251601053 ER PT S AU Scholutz, E Lesieutre, BC AF Scholutz, E. Lesieutre, B. C. GP IEEE TI Design of H-infinity observers for singular electromechanical dynamics in power networks using LMIs SO PROCEEDINGS OF THE 45TH IEEE CONFERENCE ON DECISION AND CONTROL, VOLS 1-14 SE IEEE Conference on Decision and Control LA English DT Proceedings Paper CT 45th IEEE Conference on Decision and Control CY DEC 13-15, 2006 CL San Diego, CA SP IEEE ID PARAMETER UNCERTAINTY; STATE DELAY; SYSTEMS; ESTIMATOR; STABILITY AB In this paper we focus on the design of H-infinity observers, using Linear Matrix Inequalities (LMIs), to estimate the dynamic state of a power system over a wide-area by using a limited set of sensors. We confine our attention to the electromechanical (or "swing") dynamics of a power system, but our approach can be extended to also monitor the voltage dynamics in the system. A Differential Algebraic Equation (DAE) model is used to describe the swing models that we consider in this paper. At first, we focus on the design of a singular observer using the mixed design approach for a DAE-swing model in a setting where unknown inputs and noisy measurements are present. A design for a 9-bus power system is discussed. Lastly, we investigate the design of singular H-infinity estimators that are robust to parametric model uncertainties associated with the parameters featured in DAE-swing models (e.g., transmission line impedances, generator inertias, and the damping coefficients of the generator shafts). We illustrate the result of this latter investigation on a 3-bus power system. C1 [Scholutz, E.] ABB Corporate Res, Raleigh, NC 27606 USA. [Lesieutre, B. C.] Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Scholutz, E (reprint author), ABB Corporate Res, Raleigh, NC 27606 USA. EM emst.scholtz@us.abb.com; BCLesieutre@lbl.gov FU AFOSR DoD URI [F49620-01-1-0365] FX This work was supported under the AFOSR DoD URI F49620-01-1-0365: Architectures for Secure and Robust Distributed Infrastructures, and conducted in collaboration with G. C. Verghese (MIT). NR 19 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0743-1546 BN 978-1-4244-0170-3 J9 IEEE DECIS CONTR P PY 2006 BP 4033 EP + PG 2 WC Automation & Control Systems; Engineering, Electrical & Electronic; Operations Research & Management Science SC Automation & Control Systems; Engineering; Operations Research & Management Science GA BHD08 UT WOS:000252251602163 ER PT B AU Chen, KS Hickner, MA AF Chen, Ken S. Hickner, Michael A. GP ASME TI Modeling PEM fuel cell performance using the finite-element method and a fully-coupled implicit solution scheme via Newton's technique SO Proceedings of the 4th International Conference on Fuel Cell Science, Engineering, and Technology, Pts A and B LA English DT Proceedings Paper CT 4th International Conference on Fuel Cell Science, Engineering and Technology CY JUN 19-21, 2006 CL Univ Calif Irvine, Irvine, CA SP Amer Soc Mech Engineers, Nanotechnol Inst, Univ Calif Irvine, Natl Fuel Cell Res Ctr HO Univ Calif Irvine ID POLYMER-ELECTROLYTE; TRANSPORT AB A numerical model that employs the finite-element method and a fully-coupled implicit solution scheme via Newton's technique is presented for simulating the performance of polymer-electrolyte-membrane (PEM) fuel cells. With our model, solved are the multi-dimensional momentum, mass & species, and charge conservation equations that govern, respectively, pressure-gradient driven flows along the gas flow channels (GFCs) and within the gas diffusion layers (GDLs), species transport along GFCs and within GDLs, and proton and water transport within the membrane as well as the Butler-Volmer constitutive equations describing the hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR). For simplicity, the present version of our model considers PEM fuel cell operation as isothermal and water present as vapor, and treats the anode and cathode catalyst layers as respective interfaces at which HOR and ORR take place. With our numerical approach, all governing equations are solved simultaneously and quadratic convergence is ensured due to the use of Newton's method with an analytical Jacobian. To demonstrate the utility of our computational approach,computed predictions of velocity field, contours of hydrodynamic pressure and molar concentrations of-hydrogen, oxygen and water species, and current distribution and polarization (or I-V) curves from a two-dimensional case study of a simplified PEM fuel cell are presented. To help assess the validity of our PEM fuel cell model, measurements of current distribution and polarization curves were performed using a segmented PEM fuel cell, and the resultant experimental data as well as that from the literature are compared with computed predictions. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Chen, KS (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 978-0-7918-4247-8 PY 2006 BP 81 EP 87 PG 7 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA BGQ93 UT WOS:000249884000008 ER PT B AU Berry, DA Shekhawat, D Gardner, TH Salazar, M Haynes, DJ Spivey, JJ AF Berry, David A. Shekhawat, Dushyant Gardner, Todd H. Salazar, Maria Haynes, Daniel J. Spivey, James J. GP ASME TI Support effects for Pt and Rh-based catalysts for partial oxidation of n-tetradecane SO Proceedings of the 4th International Conference on Fuel Cell Science, Engineering, and Technology, Pts A and B LA English DT Proceedings Paper CT 4th International Conference on Fuel Cell Science, Engineering and Technology CY JUN 19-21, 2006 CL Univ Calif Irvine, Irvine, CA SP Amer Soc Mech Engineers, Nanotechnol Inst, Univ Calif Irvine, Natl Fuel Cell Res Ctr HO Univ Calif Irvine DE fuel reforming; logistic fuels; carbon formation; sulfur resistance; oxygen-ion conductivity ID METHANE; GAS AB Catalytic partial oxidation (CPOX) of liquid fuels is an attractive option for producing a hydrogen-rich gas stream for fuel cell applications. However, the high sulfur content along with aromatic compounds present in liquid fuels may deactivate reforming catalysts. Deactivation of these catalysts by carbon deposition and sulfur poisoning is a key technical challenge. The relationship between catalyst supports and deactivation have been studied here for three catalysts (Rh/Ce0.5Zr0.5O2, Pt/Ce0.5Zr0.5O2, and Pt/Al2O3) in a fixed bed catalytic reactor using a mixture of n-tetradecane, 1-methyinaphthalene, and dibenzothiophene to simulate logistic fuels. Carbon production during CPOX reforming was directly related to olefin formation. Olefins, which are known coke precursors, were observed on the Pt catalysts during CPOX of n-tetradecane with no sulfur (particularly from Pt/Al2O3), but not on Rh/Ce0.5Zr0.5O2. For the Rh/Ce0.5Zr0.5O2, yields of H-2 and CO dropped to a stationary level after the introduction of sulfur-containing feed (1000 ppm sulfur) or aromatic-containing feed (5 wt%), however, the catalyst activity was restored after removing the sulfur or aromatics from the feed. For the Pt catalysts, H2 and CO yields dropped continuously over time in the presence of sulfur or aromatics in feed. The superior performance of Rh/Ce0.5Zr0.5O2 can be attributed to the higher oxygen-ion conductivity of the Ce0.5Zr0.5O2 support as well as the activity of the Rh sites. C1 US DOE, Natl Energy Technol Lab, Morgantown, WV 26507 USA. RP Berry, DA (reprint author), US DOE, Natl Energy Technol Lab, 3610 Collins Ferry Rd, Morgantown, WV 26507 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 978-0-7918-4247-8 PY 2006 BP 449 EP 452 PG 4 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA BGQ93 UT WOS:000249884000051 ER PT B AU Nguyen, BN Koeppel, BJ Vetrano, JS Khaleel, MA AF Nguyen, Ba Nghiep Koeppel, Brian J. Vetrano, John S. Khaleel, Mohammad A. GP ASME TI On the nonlinear behavior of a glass-ceramic seal and its application in planar SOFC systems SO Proceedings of the 4th International Conference on Fuel Cell Science, Engineering, and Technology, Pts A and B LA English DT Proceedings Paper CT 4th International Conference on Fuel Cell Science, Engineering and Technology CY JUN 19-21, 2006 CL Univ Calif Irvine, Irvine, CA SP Amer Soc Mech Engineers, Nanotechnol Inst, Univ Calif Irvine, Natl Fuel Cell Res Ctr HO Univ Calif Irvine AB This paper studies the nonlinear behavior of a glassceramic seal used in planar solid oxide fuel cells (SOFCs). To this end, a viscoelastic damage model has been developed that can capture the nonlinear material response due to both progressive damage in the glass-ceramic material and viscous flow of the residual glass in this material. The model has been implemented in the MSC MARC finite element code, and its validation has been carried out using the experimental relaxation test data obtained for this material at 700 degrees C, 750 degrees C, and 800 degrees C. Finally, it has been applied to the simulation of a SOFC stack under thermal cycling conditions. The areas of potential damage have been predicted. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Nguyen, BN (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. NR 8 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 978-0-7918-4247-8 PY 2006 BP 523 EP 528 PG 6 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA BGQ93 UT WOS:000249884000060 ER PT B AU Tucker, D Lawson, L Smith, TP Haynes, C AF Tucker, David Lawson, Larry Smith, Thomas P. Haynes, Comas GP ASME TI Evaluation of cathodic air flow transients in a hybrid system using hardware simulation SO Proceedings of the 4th International Conference on Fuel Cell Science, Engineering, and Technology, Pts A and B LA English DT Proceedings Paper CT 4th International Conference on Fuel Cell Science, Engineering and Technology CY JUN 19-21, 2006 CL Univ Calif Irvine, Irvine, CA SP Amer Soc Mech Engineers, Nanotechnol Inst, Univ Calif Irvine, Natl Fuel Cell Res Ctr HO Univ Calif Irvine AB Effective control of cathode airflow in a direct fired solid oxide fuel cell gas turbine (SOFC/GT) hybrid power system is critical to thermal management of a fuel cell stack. Hybrid fuel cell turbine designs often incorporate the use of a valved hot air bypass in parallel with the cathode flow to divert a portion of the compressor effluent around the fuel cell system. The primary objective of this valve in the early development of hybrid power systems was to facilitate system startup. From a system controls perspective, the hot air bypass offers the means to balance and manipulate the level of airflow supplied to the fuel cell stack at a minimal efficiency penalty. Manipulation of this valve has a significant impact on stack performance and reliability, as well as cathodic exhaust airflow conditions. Since the turbine is directly coupled to the fuel cell subsystem through the cathode airflow, non-linear effects are propagated through the system components in response to any hot air bypass valve change. The effect of cathode flow transients on hybrid system performance has been evaluated though the manipulation of a hot air bypass valve on a hardware-based simulation facility designed and built by the U.S. Department of Energy, National Energy Technology Laboratory (NETL). A brief overview of this experimental facility is provided and has been described in more detail previously. Open loop experiments were conducted using the facility, where a perturbation was made to the hot air bypass flow and turbine speed was allowed to change in response. The impact of the transients to both fuel cell and turbine performance are discussed. C1 US DOE, Natl Energy Technol Lab, Morgantown, WV 26507 USA. RP Tucker, D (reprint author), US DOE, Natl Energy Technol Lab, 3610 Collins Ferry Rd, Morgantown, WV 26507 USA. NR 11 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 978-0-7918-4247-8 PY 2006 BP 585 EP 594 PG 10 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA BGQ93 UT WOS:000249884000067 ER PT B AU Gemmen, RS Johnson, CD AF Gemmen, Randall S. Johnson, Christopher D. GP ASME TI Thermal gradient induced current recirculation on load change in solid oxide fuel cells SO Proceedings of the 4th International Conference on Fuel Cell Science, Engineering, and Technology, Pts A and B LA English DT Proceedings Paper CT 4th International Conference on Fuel Cell Science, Engineering and Technology CY JUN 19-21, 2006 CL Univ Calif Irvine, Irvine, CA SP Amer Soc Mech Engineers, Nanotechnol Inst, Univ Calif Irvine, Natl Fuel Cell Res Ctr HO Univ Calif Irvine ID SOFC; SYSTEM; MODEL AB This paper considers recent model results examining the transient performance of three common solid oxide fuel cell (SOFC) geometries (cross-flow, co-flow, and counter-flow) during load reduction events. Of particular note for large load decrease (e.g., shutdown) is the occurrence of reverse current over significant portions of the cell, starting from the moment of load loss up to the point where equilibrated conditions again provide positive current. This behavior results from the temperature gradients that exist in an SOFC stack. Also reported are test results from an experiment employing two separate button cells coupled together electrically (anode-to-anode and cathode-to-cathode) which are used to confirm the model predictions. The test results confirm the predictions of the model in that temperature gradients are a driver for current circulation within a cell. Also reported are test results of a button cell operated under reverse current to help begin to identify what effects such operation may have on fuel cell performance and durability. C1 US DOE, Natl Energy Technol Lab, Morgantown, WV 26507 USA. RP Gemmen, RS (reprint author), US DOE, Natl Energy Technol Lab, 3610 Collins Ferry Rd, Morgantown, WV 26507 USA. NR 14 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 978-0-7918-4247-8 PY 2006 BP 691 EP 699 PG 9 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA BGQ93 UT WOS:000249884000081 ER PT B AU Krause, TR Ahmed, S Kumar, R AF Krause, T. R. Ahmed, S. Kumar, R. GP ASME TI Distributed reforming of diesel, JP-8, and other heavy hydrocarbon fuels for fuel cell applications: Challenges and issues SO Proceedings of the 4th International Conference on Fuel Cell Science, Engineering, and Technology, Pts A and B LA English DT Proceedings Paper CT 4th International Conference on Fuel Cell Science, Engineering and Technology CY JUN 19-21, 2006 CL Univ Calif Irvine, Irvine, CA SP Amer Soc Mech Engineers, Nanotechnol Inst, Univ Calif Irvine, Natl Fuel Cell Res Ctr HO Univ Calif Irvine ID SELECTIVE ADSORPTION; DEEP DESULFURIZATION; PART I; HYDROGEN; OXIDATION; CATALYSTS; PROCESSOR; GASOLINE; SYSTEMS; PEFC AB Reforming diesel, JP-8 (Jet Propellant 8 - standard U.S. military kerosene-based jet fuel), and other heavy hydrocarbon fuels' is one option being investigated for providing H-2 for distributed mobile and stationary fuel cell systems for military and civilian applications. Unlike natural gas, which is another hydrocarbon fuel being investigated, these fuels are high-boiling-point, multi-component liquids that contain high concentrations of refractory sulfur and aromatic compounds that can negatively impact the efficiency and operating lifetime of the fuel processor. Fuel injection, desulfurization, and carbon deposition are major issues that fuel processor developers must address when designing fuel processors for these fuels. The fuel injection system must prevent direct injection of liquid onto the catalyst surface and poor mixing of the fuel and oxidants (i.e., air and/or steam), both of which can result in excessively high temperatures that can damage or destroy the reforming catalyst. A highly efficient desulfurization process is required that can reduce the sulfur concentration to acceptable levels for both fuel processor and fuel cell catalysts without requiring large amounts of materials or complicated processes, and without generating excessive amounts of disposable waste. Highly active reforming catalysts and the proper choice of operating conditions (i.e., ratio of fuel to oxidant[s], temperature, residence time) are required for effective reforming of aromatic compounds to prevent carbon deposition on the reforming catalyst as well as in the fuel processor downstream of the reformer. In this paper, we will discuss how the chemical and physical properties of these fuels influence the design of the fuel processor focusing on the fuel injection system, the choice of desulftirization process, and the design and operation of the reformer. We will also discuss various approaches and design options for developing highly efficient fuel processors for reforming these fuels for both polymer electrolyte and solid oxide fuel cells. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Krause, TR (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 29 TC 0 Z9 0 U1 2 U2 3 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 978-0-7918-4247-8 PY 2006 BP 787 EP 792 PG 6 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA BGQ93 UT WOS:000249884000091 ER PT B AU Kelly, KJ Pacific, GC Penev, M Vlahinos, A AF Kelly, Kenneth J. Pacific, Gregory C. Penev, Michael Vlahinos, Andreas GP ASME TI Robust design techniques for evaluating fuel cell thermal performance SO Proceedings of the 4th International Conference on Fuel Cell Science, Engineering, and Technology, Pts A and B LA English DT Proceedings Paper CT 4th International Conference on Fuel Cell Science, Engineering and Technology CY JUN 19-21, 2006 CL Univ Calif Irvine, Irvine, CA SP Amer Soc Mech Engineers, Nanotechnol Inst, Univ Calif Irvine, Natl Fuel Cell Res Ctr HO Univ Calif Irvine AB The National Renewable Energy Laboratory (NREL) and Plug Power Inc. have been working together to develop fuel cell modeling processes to rapidly assess critical design parameters and evaluate the effects of variation on performance. This paper describes a methodology for investigating key design parameters affecting the thermal performance of a high temperature, polybenzimidazole (PBI)-based fuel cell stack. Nonuniform temperature distributions within the fuel cell stack may cause degraded performance, induce thermo-mechanical stresses, and be a source of reduced stack durability. The three-dimensional (3-D) model developed for this project includes coupled thermal/flow finite element analysis (FEA) of a multi-cell stack integrated with an electrochemical model to determine internal heat generation rates. Sensitivity and optimization algorithms were used to examine the design and derive the best choice of the design parameters. Initial results showed how classic design-of-experiment (DOE) techniques integrated with the model were used to define a response surface and perform sensitivity studies on heat generation rates, fluid flow, bipolar plate channel geometry, fluid properties, and plate thermal material properties. Probabilistic design methods were used to assess the robustness of the design in response to variations in load conditions. The thermal model was also used to develop an alternative coolant flow-path design that yields improved thermal performance. Results from this analysis were recently incorporated into the latest Plug Power coolant flow-path design. This paper presents an evaluation of the effect of variation on key design parameters such as coolant and gas flow rates and addresses uncertainty in material thermal properties. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Kelly, KJ (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 978-0-7918-4247-8 PY 2006 BP 843 EP 852 PG 10 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA BGQ93 UT WOS:000249884000096 ER PT J AU Bailey, DH Misiurewicz, M AF Bailey, DH Misiurewicz, M TI A strong hot spot theorem SO PROCEEDINGS OF THE AMERICAN MATHEMATICAL SOCIETY LA English DT Article DE normal numbers AB A real number alpha is said to be b-normal if every m-long string of digits appears in the base-b expansion of a with limiting frequency b(-m). We prove that alpha is b-normal if and only if it possesses no base-b "hot spot". In other words, alpha is b-normal if and only if there is no real number y such that smaller and smaller neighborhoods of y are visited by the successive shifts of the base-b expansion of alpha with larger and larger frequencies, relative to the lengths of these neighborhoods. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Indiana Univ Purdue Univ, Dept Math Sci, Indianapolis, IN 46202 USA. RP Bailey, DH (reprint author), Lawrence Berkeley Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM dhbailey@lbl.gov; mmisiure@math.iupui.edu NR 6 TC 8 Z9 8 U1 0 U2 1 PU AMER MATHEMATICAL SOC PI PROVIDENCE PA 201 CHARLES ST, PROVIDENCE, RI 02940-2213 USA SN 0002-9939 J9 P AM MATH SOC JI Proc. Amer. Math. Soc. PY 2006 VL 134 IS 9 BP 2495 EP 2501 DI 10.1090/S0002-9939-06-08551-0 PG 7 WC Mathematics, Applied; Mathematics SC Mathematics GA 042FS UT WOS:000237513900003 ER PT B AU Lee, T Fischer, PF AF Lee, Taehun Fischer, Paul F. GP ASME TI A LATTICE BOLTZMANN EQUATION METHOD WITHOUT PARASITIC CURRENTS AND ITS APPLICATION IN DROPLET COALESCENCE SO PROCEEDINGS OF THE ASME FLUIDS ENGINEERING DIVISION SUMMER CONFERENCE, VOL 1, PTS A AND B LA English DT Proceedings Paper CT 2nd US-European Fluids Engineering Division Summer Meeting CY JUL 17-20, 2006 CL Miami, FL SP ASME, Fluids Engn Div ID NONIDEAL GASES; SIMULATION; FLUIDS; FLOWS; MODEL AB A formulation of the intermolecular force in the nonideal gas lattice Boltzmann equation (LBE) method is examined. Discretization errors in the computation of the intermolecular force cause parasitic currents. The parasitic currents can be eliminated to round-off if the potential form of the intermolecular force is used with compact isotropic discretization. Numerical tests confirm the elimination of the parasitic currents. In order to demonstrate the applicability of the present model, inertial coalescence of droplets at high density ratio is studied. C1 [Lee, Taehun; Fischer, Paul F.] Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Lee, T (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM thlee@ccny.cuny.edu; fischer@mcs.anl.gov OI Lee, Taehun/0000-0001-9965-5637 NR 20 TC 1 Z9 1 U1 0 U2 1 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 978-0-7918-4750-3 PY 2006 BP 675 EP 681 PG 7 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BLH19 UT WOS:000270164100079 ER PT B AU Chen, J Odier, P Rivera, M Ecke, R AF Chen, Jun Odier, Philippe Rivera, Michael Ecke, Robert GP ASME TI MEASUREMENT OF TURBULENT MIXING ALONG SLOPE IN STRATIFIED FLOW SO PROCEEDINGS OF THE ASME FLUIDS ENGINEERING DIVISION SUMMER CONFERENCE, VOL 2 LA English DT Proceedings Paper CT 2nd US-European Fluids Engineering Division Summer Meeting/14th International Conference on Nuclear Engineering CY JUL 17-20, 2006 CL Miami, FL SP Amer Soc Mech Engineers, Fluids Engn Div, Assoc Francaise Mecan Engineers, Assoc Italiana Meccan Teor & Applicata, Verein Deutsch Ingenieure, Inst Mech Engineers, JM Burgers Ctr Fluid Mech ID NORTH-ATLANTIC; ENTRAINMENT; ENVIRONMENTS; ACCURACY; MODELS; FLUID; PIV AB The mixing phenomenon of ocean currents, which have different densities as well as velocities, are important to ocean dynamics and global climate modeling. One example is the outflow of the Greenland-Iceland-Norwegian Seas, where dense Arctic water overflows a ridge and spills downslope in a density-driven plume until it reaches the deep abyss of the Atlantic Ocean. On the way down it mixes with ambient water of different temperature and salinity. This process affects the global thermohaline circulation, which is a significant element in changes of the global climate. Laboratory experiments are conducted to investigate this problem. A turbulent jet is introduced into a water tank along an inclined plate. The density difference between the jet and the tank water produces a stably stratified boundary current. Particle Image Velocimetry (PIV) and Planar Laser Induced Fluorescence (PLIF) are applied to obtain simultaneous measurement of velocity field and density field along the slope at different downstream locations. On-going efforts are also discussed. C1 [Chen, Jun; Odier, Philippe; Rivera, Michael; Ecke, Robert] Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, Los Alamos, NM 87545 USA. RP Chen, J (reprint author), Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, POB 1663, Los Alamos, NM 87545 USA. OI Ecke, Robert/0000-0001-7772-5876 NR 17 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 978-0-7918-4751-0 PY 2006 BP 27 EP 34 PG 8 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BMF57 UT WOS:000272191800004 ER PT B AU Xu, ZL Samulyak, R Glimm, J Li, XL AF Xu, Zhiliang Samulyak, Roman Glimm, James Li, Xiaolin GP ASME TI DISCRETE BUBBLE MODELING OF UNSTEADY CAVITATING FLOW SO PROCEEDINGS OF THE ASME FLUIDS ENGINEERING DIVISION SUMMER CONFERENCE, VOL 2 LA English DT Proceedings Paper CT 2nd US-European Fluids Engineering Division Summer Meeting/14th International Conference on Nuclear Engineering CY JUL 17-20, 2006 CL Miami, FL SP Amer Soc Mech Engineers, Fluids Engn Div, Assoc Francaise Mecan Engineers, Assoc Italiana Meccan Teor & Applicata, Verein Deutsch Ingenieure, Inst Mech Engineers, JM Burgers Ctr Fluid Mech AB A discrete vapor bubble model is developed to simulate the unsteady cavitating flows. The mixed vapor-liquid mixture is modeled as a system of pure phase domains (vapor and liquid) separated by free interfaces. On the phase boundary, a numerical solution for the phase transition is developed for compressible flows. C1 [Xu, Zhiliang; Samulyak, Roman; Glimm, James] Brookhaven Natl Lab, Computat Sci Ctr, Upton, NY 11973 USA. RP Xu, ZL (reprint author), Brookhaven Natl Lab, Computat Sci Ctr, Upton, NY 11973 USA. EM xuzhi@bnl.gov; rosamu@bnl.gov; glimm@ams.sunysb.edu; linli@ams.sunysb.edu RI Xu, Zhiliang/O-1718-2014 NR 12 TC 0 Z9 0 U1 0 U2 3 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 978-0-7918-4751-0 PY 2006 BP 115 EP 120 PG 6 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BMF57 UT WOS:000272191800018 ER PT B AU Wendel, M Felde, D Karnowski, T Riemer, B Ruggles, A AF Wendel, Mark Felde, David Karnowski, Thomas Riemer, Bernard Ruggles, Arthur GP ASME TI EXPERIMENTS AND SIMULATIONS WITH LARGE GAS BUBBLES IN MERCURY TOWARDS ESTABLISHING A GAS LAYER TO MITIGATE CAVITATION DAMAGE SO PROCEEDINGS OF THE ASME FLUIDS ENGINEERING DIVISION SUMMER CONFERENCE, VOL 2 LA English DT Proceedings Paper CT 2nd US-European Fluids Engineering Division Summer Meeting/14th International Conference on Nuclear Engineering CY JUL 17-20, 2006 CL Miami, FL SP Amer Soc Mech Engineers, Fluids Engn Div, Assoc Francaise Mecan Engineers, Assoc Italiana Meccan Teor & Applicata, Verein Deutsch Ingenieure, Inst Mech Engineers, JM Burgers Ctr Fluid Mech AB One option that shows promise for protecting solid surfaces from cavitation damage in liquid metal spallation targets involves introducing an interstitial gas layer between the liquid metal and the containment vessel wall. Several approaches toward establishing such a protective gas layer are being investigated at the Oak Ridge National Laboratory' including large bubble injection and methods that involve stabilization of the layer by surface modifications to enhance gas hold-up on the wall or by inserting a porous media. It has previously been reported that using a gas layer configuration in a test target showed an order-of-magnitude decrease in damage for an in-beam experiment. Video images that were taken of the successful gas/mercury flow configuration have been analyzed and correlated. The results show that the success was obtained under conditions where only 60% of the solid wall was covered with gas. Such a result implies that this mitigation scheme may have much more potential. Additional experiments with gas injection into water are underway. Multi-component flow simulations are also being used to provide direction for these new experiments. These simulations have been used to size the gas layer and position multiple inlet nozzles. C1 [Wendel, Mark; Felde, David; Karnowski, Thomas; Riemer, Bernard] Oak Ridge Natl Lab, Oak Ridge, TN USA. RP Wendel, M (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN USA. OI Riemer, Bernard/0000-0002-6922-3056 NR 9 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 978-0-7918-4751-0 PY 2006 BP 121 EP 126 PG 6 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BMF57 UT WOS:000272191800019 ER PT B AU Bamberger, JA AF Bamberger, Judith Ann GP ASME TI USING ULTRASOUND TO CHARACTERIZE PULP SLURRIES WITH ENTRAINED AIR SO PROCEEDINGS OF THE ASME FLUIDS ENGINEERING DIVISION SUMMER CONFERENCE, VOL 2 LA English DT Proceedings Paper CT 2nd US-European Fluids Engineering Division Summer Meeting/14th International Conference on Nuclear Engineering CY JUL 17-20, 2006 CL Miami, FL SP Amer Soc Mech Engineers, Fluids Engn Div, Assoc Francaise Mecan Engineers, Assoc Italiana Meccan Teor & Applicata, Verein Deutsch Ingenieure, Inst Mech Engineers, JM Burgers Ctr Fluid Mech ID SUSPENSIONS; ATTENUATION; PROPAGATION; MIXTURES; SOUND AB The development of fast and practical methods for inspecting fiber suspensions is of great interest in the paper making industry. For process control and paper quality prediction, several elements of the refining process during paper making must be accurately monitored, including specific fiber properties, weight percent fiber (composition), degree of refining, amount of solids, and entrained air content. The results of previous ultrasonic studies applied to wood pulp provide guidance that ultrasound attenuation is information rich, and it does potentially provide a tool for consistency measurement. Ultrasound has the ability to penetrate dense suspensions such as wood pulp slurries. It is has been shown, in some studies, that ultrasound is sensitive to degree of refining. The effects of entrained air, additives, the origin and treatment of the fibers do however all influence the measured data. A series of measurements were made with hardwood and softwood slurries to evaluate the ability of measuring pulp consistency, solids, and entrained air. The attenuation through the slurry was measured as the ultrasound travels from one transducer through the slurry to the other. The measurements identified the presence of entrained air in the pulp samples. To better understand the effects of air, measurements were made at increasing pressures to show how increased pressure reduced the amount of air observed in the spectrum. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Bamberger, JA (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. EM Judith.Bamberger@pnl.gov NR 7 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 978-0-7918-4751-0 PY 2006 BP 463 EP 465 PG 3 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BMF57 UT WOS:000272191800065 ER PT B AU Duignan, MR Lee, SY AF Duignan, Mark R. Lee, Si Y. GP ASME TI CROSS-FLOW ULTRAFILTRATION SCALING CONSIDERATIONS SO PROCEEDINGS OF THE ASME FLUIDS ENGINEERING DIVISION SUMMER CONFERENCE, VOL 2 LA English DT Proceedings Paper CT 2nd US-European Fluids Engineering Division Summer Meeting/14th International Conference on Nuclear Engineering CY JUL 17-20, 2006 CL Miami, FL SP Amer Soc Mech Engineers, Fluids Engn Div, Assoc Francaise Mecan Engineers, Assoc Italiana Meccan Teor & Applicata, Verein Deutsch Ingenieure, Inst Mech Engineers, JM Burgers Ctr Fluid Mech DE Small-scale; Pilot-scale; Radioactive Waste; Two-Phase Flow AB One legacy of the nuclear age is radioactive waste and it must be stabilized to be stored in a safe manner. An important part of the stabilization process is the separation of radioactive solids from the liquid wastes by cross-flow ultrafiltration. The performance of this technology with the wastes to be treated was unknown and, therefore, had to be obtained. However, before beginning a filter study the question of experimental scale had to be addressed. Of course, carrying out experiments using full-size equipment is always ideal, but rarely practical when dealing with plant size processes. Flow loops that will handle millions of liters of slurries, which are either highly caustic or acidic, with flow rates of 10,000 lpm make full-scale tests prohibitively expensive. Moreover, when the slurries happen to be radioactive such work is also very dangerous. All of these considerations lend themselves to investigations at smaller scales and in many situations can be treated with computational analyses. Unfortunately, as scale is reduced it becomes harder to provide prototypic results and the two and three phase multi-component mixtures challenge accurate computational results. To obtain accurate and representative filter results two smaller scale filters were chosen: 1. Small-scale - would allow the testing with actual radioactive waste samples and compare results with simulated wastes that were not radioactive. For this scale the feed tank held 6 liters of waste and it had a single cross-flow filter tube 0.61 m long. 2. Pilot-scale - would be restricted to use simulated non-radioactive wastes. At this larger scale the feed tank held 120 liters of waste and the filter unit was prototypic to the planned plant facility in pore size (0.1 micron), length (2.29 m), diameter (0.0127 m inside and 0.0159 m outside diameter), and being multi-tubed. The small-scale apparatus is convenient, easy to use, and can test both radioactive and non-radioactive wastes; therefore, there is a larger database than at the pilot scale. In fact, the small-scale data are very useful to compare actual waste to simulated waste filter performance to validate a simulant, but data availability does not mean they accurately represent full-scale performance. Results indicate that small-scale filter fluxes to be significantly higher that those at the pilot scale. In an attempt to study the difference in filter performance at the two scales an experiment was done that used exactly the same simultant which was created at the same time so that issues of composition and aging would not compromise the results. This paper will discuss those experimental results, as well as those from a computational fluid dynamics model to better understand the small-scale limitations. C1 [Duignan, Mark R.; Lee, Si Y.] Savannah River Natl Lab, Aiken, SC 29808 USA. RP Duignan, MR (reprint author), Savannah River Natl Lab, Aiken, SC 29808 USA. EM mark.duignan@srnl.doe.gov NR 15 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 978-0-7918-4751-0 PY 2006 BP 467 EP 477 PG 11 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA BMF57 UT WOS:000272191800066 ER PT B AU Hu, ZY Thundat, T AF Hu, Zhiyu Thundat, Thomas GP ASME TI Nanoscale energy conversion by using nano-catalytic particles SO Proceedings of the ASME Power Conference LA English DT Proceedings Paper CT ASME Power Conference 2006 CY MAY 02-04, 2006 CL Atlanta, GA SP Amer Soc Mech Engineers, Power Div AB Burning or combustion is the most common energy conversion method of which the chemical energy stored is converted to the thermal energy during an oxidation process. Governed by the scaling and thermodynamic laws, there is a minimum size requirement (similar to 1 mm) for having a sustainable reaction. Conventional combustion or burning usually takes place when the reactants' temperature is much higher than the body temperatures of biological beings. All heat engines including both external combustion engines and internal combustion engines were developed using this phenomenon; and reaction processes proceed in macroscale where big machines and large reaction chambers are often employed. As an attempt to mimic nature's method of energy conversion, without external ignition, nano-catalytic particles could be self-heated very rapidly (in seconds) in the present of methanol or ethanol vapor/air mixture flow. Stable and reproducible spontaneous self-ignition and self-supporting combustion have been achieved at room temperature by exposing nanometersized catalytic particles to methanol-air or ethanol-air gas mixtures. Infrared thermography revealed that the thermal gradient near nanoparticles could be more than 100 times higher than what could be achieved in macroscale. The reaction releases heat and produces CO2 and water. Such reactions starting at ambient temperature have reached both high (> 600 degrees C) and low (a few tenths of a degree above room temperature) reaction temperatures. The reaction intensity could be easily controlled by varying the fuel-air mixture. The application of this discovery might lead to the development of a new class of solid state electrical power generators which could convert fuel energy to electricity without any moving parts. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Hu, ZY (reprint author), Oak Ridge Natl Lab, 1 Bethel Valley Rd,POB 2008,MS-6123, Oak Ridge, TN 37831 USA. NR 11 TC 2 Z9 2 U1 0 U2 2 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 978-0-7918-4205-8 PY 2006 BP 545 EP 550 PG 6 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA BGQ92 UT WOS:000249859600062 ER PT B AU Cheng, RK Littlejohn, D Nazeer, WA Smith, KO AF Cheng, R. K. Littlejohn, D. Nazeer, W. A. Smith, K. O. GP ASME TI Laboratory studies of the flow field characteristics of low-swirl injectors for adaptation to fuel-flexible turbines SO Proceedings of the ASME Turbo Expo 2006, Vol 1 LA English DT Proceedings Paper CT 51st ASME Turbo Expo CY MAY 06-11, 2006 CL Barcelona, SPAIN SP Amer Soc Mech Engineers, Int Gas Turbine Inst ID INTENSE ISOTROPIC TURBULENCE; PREMIXED FLAMES; GAS-TURBINES; COMBUSTORS; DYNAMICS; VELOCITY; BOILERS; BURNER AB The low-swirl injector (LSI) is a simple and cost-effective lean premixed combustion method for natural-gas turbines to achieve ultra-low emissions (< 5 ppm NOx and CO) without invoking tight control of mixture stoichiometry, elaborate active tip cooling or costly materials and catalysts. To gain an understanding of how this flame stabilization mechanism remains robust throughout a large range of Reynolds numbers, laboratory experiments were performed to characterize the flowfield of natural gas flames at simulated partial load conditions. Also studied was a flame using simulated landfill gas of 50% natural gas and 50% CO2. Using Particle Image Velocimetry (PIV), the non-reacting and reacting flowfields were measured at five bulk flow velocities. The results show that the LSI flowfield exhibits similarity features. From the velocity data an analytical expression for the flame position as function of the flowfield characteristics and turbulent flame speed have been deduced. It shows that the similarity feature coupled with a linear dependency of the turbulent flame speed with bulk flow velocity enable the flame to remain relatively stationary throughout the load range. This expression can be the basis for an analytical model for designing LSIs that operate on alternate gaseous fuels such as slower burning biomass gases or faster burning coal-based syngases. C1 Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RP Cheng, RK (reprint author), Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. NR 18 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 0-7918-4236-3 PY 2006 BP 649 EP 662 PG 14 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA BFN89 UT WOS:000243377500065 ER PT B AU Ellingson, WA Deemer, CM Sun, JG Koehl, ER AF Ellingson, William A. Deemer, Christopher M. Sun, Jiangang Koehl, Eugene R. GP ASME TI NDE technology for ceramic composites SO Proceedings of the ASME Turbo Expo 2006, Vol 2 LA English DT Proceedings Paper CT 51st ASME Turbo Expo CY MAY 06-11, 2006 CL Barcelona, SPAIN SP Amer Soc Mech Engineers, Int Gas Turbine Inst ID MATRIX COMPOSITES; DAMAGE AB Installation of gas turbine components made of ceramic matrix composite (CIVIC) materials, which have limited test bed data bases, can put test engines at risk. Further, changes in properties of the materials of these components have been shown to occur with exposure. Risks to the engine can be mitigated through the application of proper nondestructive inspection methods. Further, while still under development, proper application of certain nondestructive evaluation (NDE) technologies seem likely to be able to provide data that can be correlated to retained strength or other properties of these composite materials. If sufficient data were available informed decisions could be made regarding reuse, repair or replace with appropriate NDE. Over the past fourteen years, Argonne National Laboratory (ANL), has been developing various NDE methods specifically for CIVIC materials. These NDE technologies include: infrared-based thermal imaging, air-coupled ultrasonic approaches, high spatial resolution x-ray computed tomography and more recently optical coherence tomography and guided plate waves. This paper will review the developments of these NDE technologies and will provide results with collaboration from engine and laboratory materials tests. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Ellingson, WA (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 23 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 0-7918-4237-1 PY 2006 BP 285 EP 293 PG 9 WC Engineering, Mechanical SC Engineering GA BFN90 UT WOS:000243377700029 ER PT B AU Liese, EA Gemmen, RS Smith, TP Haynes, CL AF Liese, Eric A. Gemmen, Randall S. Smith, Thomas P. Haynes, Comas L. GP ASME TI A dynamic bulk SOFC model used in a hybrid turbine controls test facility SO Proceedings of the ASME Turbo Expo 2006, Vol 4 LA English DT Proceedings Paper CT 51st ASME Turbo Expo CY MAY 06-11, 2006 CL Barcelona, SPAIN SP Amer Soc Mech Engineers, Int Gas Turbine Inst ID FUEL-CELL; PERFORMANCE AB The paper will describe the dynamic model of a pressurized Solid Oxide Fuel Cell (SOFC). The model is required to run on a digital controller in real-time so that its predicted thermal output may be used to control the fuel valve of an experimental hybrid system that is being used to investigate control methods for fuel cell / gas turbine hybrid systems. The model presented is a bulk model in order to best guarantee real-time operation. The equations and parameters used in the model are presented. The effects of pressure are partially considered and a V-I and P-I curve are plotted in order to show the general fuel cell model behavior. Also presented are dynamic comparisons to a 1-D model. The integration of the model with the experimental system is shown as well. C1 Natl Energy Technol Lab, Morgantown, WV 26508 USA. RP Liese, EA (reprint author), Natl Energy Technol Lab, 3610 Collins Ferry Rd, Morgantown, WV 26508 USA. NR 9 TC 0 Z9 0 U1 0 U2 2 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 0-7918-4239-8 PY 2006 BP 117 EP 126 PG 10 WC Energy & Fuels; Engineering, Mechanical; Metallurgy & Metallurgical Engineering SC Energy & Fuels; Engineering; Metallurgy & Metallurgical Engineering GA BFN93 UT WOS:000243378600011 ER PT B AU Tucker, D Lawson, L VanOsdol, J Kislear, J Akinbobuyi, A AF Tucker, David Lawson, Larry VanOsdol, John Kislear, Jordan Akinbobuyi, Ayodeji GP ASME TI Examination of ambient pressure effects on hybrid solid oxide fuel cell turbine system operation using hardware simulation SO Proceedings of the ASME Turbo Expo 2006, Vol 4 LA English DT Proceedings Paper CT 51st ASME Turbo Expo CY MAY 06-11, 2006 CL Barcelona, SPAIN SP Amer Soc Mech Engineers, Int Gas Turbine Inst ID SURGE AB The effect of ambient inlet air pressure variations on the compressor performance in a direct fired solid oxide fuel cell gas turbine hybrid power system has been studied using the Hybrid Performance (Hyper) project hardware simulation facility at the U.S. Department of Energy, National Energy Technology Laboratory (NETL). The Hyper facility at NETL makes use of a high speed numerical model which controls a burner and a series of pressure vessels and piping to collectively simulate a direct-fired, high-temperature fuel cell. The hardware simulating the fuel cell is integrated into the system with a modified single shaft turbine driven compressor and a pair of recuperates to provide cathode air preheat from the turbine exhaust. Orifice plates were employed at the compressor inlet of the facility to parametrically vary the inlet pressure. The compressor inlet temperature for all tests conducted was held within a 2 Kelvin range. Variation in inlet pressure was shown to have a significant effect on many hybrid system performance parameters. Some system parameters were shown to have a linear dependency on the inlet pressure, leading to the implementation of correction factors. Similar dependence of compressor discharge pressure and temperature on compressor inlet pressure was predicted by dynamic models based on isentropic compression principles. Transient operation was also impacted by changes in compressor inlet pressure. Startup profiles are shown against the compressor stall line for indication of changes in surge margin. C1 US DOE, Natl Energy Technol Lab, Morgantown, WV 26507 USA. RP Tucker, D (reprint author), US DOE, Natl Energy Technol Lab, 3610 Collins Ferry Rd, Morgantown, WV 26507 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 0-7918-4239-8 PY 2006 BP 449 EP 457 PG 9 WC Energy & Fuels; Engineering, Mechanical; Metallurgy & Metallurgical Engineering SC Energy & Fuels; Engineering; Metallurgy & Metallurgical Engineering GA BFN93 UT WOS:000243378600045 ER PT B AU Pint, BA More, KL Trejo, R Lara-Curzio, E AF Pint, Bruce A. More, Karren L. Trejo, Rosa Lara-Curzio, Edgar GP ASME TI Comparison of recuperator alloy degradation in laboratory and engine testing SO Proceedings of the ASME Turbo Expo 2006, Vol 5, Pts A and B LA English DT Proceedings Paper CT 51st ASME Turbo Expo CY MAY 06-11, 2006 CL Barcelona, SPAIN SP Amer Soc Mech Engineers, Int Gas Turbine Inst ID WATER-VAPOR; OXIDATION; STEEL AB In order to increase the efficiency of advanced microturbines, durable alloy foils are needed for their recuperators to operate at 650 degrees-700 degrees C. Prior work has demonstrated that water vapor in the exhaust gas causes more rapid consumption of Cr from austenitic alloys leading to a reduction in lifetime for the thin-walled components in this application. New commercial alloy foils are being tested in both laboratory tests in humid air and in the exhaust gas of a modified 60kW microturbine. Initial results are presented for a commercial batch of 80 mu m alloy 120 foil. The Cr consumption rates in laboratory testing were similar to those observed in previous testing. The initial results from the microturbine indicate a faster Cr consumption rate compared to the laboratory test but longer term results are needed to quantify the difference. These results will help to verify a Cr consumption model for predicting lifetimes in this environment based on classical gas transport theory. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Pint, BA (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI Pint, Bruce/A-8435-2008; More, Karren/A-8097-2016 OI Pint, Bruce/0000-0002-9165-3335; More, Karren/0000-0001-5223-9097 NR 27 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 0-7918-4240-1 PY 2006 BP 217 EP 224 PG 8 WC Engineering, Mechanical SC Engineering GA BFJ48 UT WOS:000242368000026 ER PT B AU Maziasz, PJ Shingledecker, JP Evans, ND Yamamoto, Y More, KL Trejo, R Lara-Curzio, E Stinner, CP AF Maziasz, Philip J. Shingledecker, John P. Evans, Neal D. Yamamoto, Yukinori More, Karren L. Trejo, Rosa Lara-Curzio, Edgar Stinner, Charles P. GP ASME TI Creep strength and microstructure of AL20-25+Nb alloy sheets and foils for advanced microturbine recuperators SO Proceedings of the ASME Turbo Expo 2006, Vol 5, Pts A and B LA English DT Proceedings Paper CT 51st ASME Turbo Expo CY MAY 06-11, 2006 CL Barcelona, SPAIN SP Amer Soc Mech Engineers, Int Gas Turbine Inst AB The Oak Ridge National Laboratory (ORNL) and ATI Allegheny-Ludlum began a collaborative program in 2004 to produce a wide range of commercial sheets and foils of the new AL20-25+Nb stainless alloy, specifically designed for advanced microturbine recuperator applications. There is a need for cost-effective sheets/foils with more performance and reliability at 650-750 degrees C than 347 stainless steel, particularly for larger 200250 kW microturbines. Phase I of this collaborative program produced the sheets and foils needed for manufacturing brazed plated-fin (BPF) aircells, while Phase II provided foils for primary surface (PS) aircells, and modified processing to change the microstructure of sheets and foils for improved creep-resistance. Phase I sheets and foils of AL20-25+Nb have much more creep-resistance than 347 steel at 700-750 degrees C, and foils are slightly stronger than HR120 and HR230. Preliminary results for Phase II show nearly double the creep-rupture life of sheets at 750 degrees C/100 MPa, with the first foils tested approaching the creep resistance of alloy 625 foils. AL20-25+Nb alloy foils are also now being tested in the ORNL Recuperator Test Facility. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Maziasz, PJ (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Evans, Neal/F-5955-2011; More, Karren/A-8097-2016; OI More, Karren/0000-0001-5223-9097; Maziasz, Philip/0000-0001-8207-334X NR 16 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 0-7918-4240-1 PY 2006 BP 225 EP 236 PG 12 WC Engineering, Mechanical SC Engineering GA BFJ48 UT WOS:000242368000027 ER PT B AU Robinett, RD Wilson, DG AF Robinett, Rush D., III Wilson, David G. BE Su, CY TI Exergy and irreversible entropy production thermodynamic concepts for control design: Nonlinear regulator systems SO Proceedings of the Eighth IASTED International Conference on Control and Applications LA English DT Proceedings Paper CT 8th IASTED International Conference on Control and Applications CY MAY 24-26, 2006 CL Montreal, CANADA SP Int Assoc Sci & Technol Dev DE thermodynamics; nonlinear control; exergy; entropy; Lyapunov ID STATE-SPACE THEORY; ENERGY CONCEPTS; PASSIVITY; PORTS AB This paper(1) develops a novel control system design methodology that uniquely combines: concepts from thermodynamic exergy and entropy; Hamiltonian systems; Lyapunov's direct method and Lyapunov optimal analysis; electric AC power concepts; and power flow analysis. Relationships are derived between exergy/entropy and Lyapunov optimal functions for Hamiltonian systems. The methodology is demonstrated with two fundamental numerical simulation examples: 1) a Duffing oscillator/Coulomb friction nonlinear model that employs PID regulator control and 2) a van der Pol nonlinear oscillator system. The control system performances and/or appropriately identified terms are partitioned and evaluated based on exergy generation and exergy dissipation terms. This novel nonlinear control methodology results in both necessary and sufficient conditions for stability of nonlinear systems. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Robinett, RD (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 22 TC 0 Z9 0 U1 0 U2 0 PU ACTA PRESS ANAHEIM PI ANAHEIM PA PO BOX 5124, ANAHEIM, CA 92814-5124 USA BN 0-88986-596-5 PY 2006 BP 308 EP 315 PG 8 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Robotics SC Automation & Control Systems; Computer Science; Robotics GA BEW00 UT WOS:000239717600053 ER PT S AU Trease, L Trease, H Fowler, J AF Trease, Lynn Trease, Harold Fowler, John BE Hwang, JN TI Quantitative 3-D imaging, segmentation and feature extraction of the respiratory system in small mammals for computational biophysics simulations SO Proceedings of the Eighth IASTED International Conference on Signal and Image Processing SE IASTED International Conference on Signal and Image Processing LA English DT Proceedings Paper CT 8th IASTED International Conference on Signal and Image Processing CY AUG 14-16, 2006 CL Honolulu, HI SP Int Assoc Sci & Technol Dev DE image segmentation; image reconstruction; and feature extraction AB One of the critical steps toward performing computational biology simulations, using boundary-fitted / volume-filling mesh based integration methods, is having available topologically faithful feature geometry derived from experimental digital image data as the basis for generating the computational meshes. Digital image data representations contain both the topology of the geometric features and experimental field-data distributions, they just have to be teased out using image processing tools. The geometric features that need to be captured from the digital image data are complex and three-dimensional. Therefore, the process and tools we have developed to perform feature extraction work as volumetric image data represented as data-cubes, these data-cubes are formed from stacks of 2-D images. This allows us to take advantage of curvature information, of 2-D surfaces in 3-D space, during the segmentation and feature extraction process. The process is basically: 1) segmenting to isolate and enhance the contrast of the features that we wish to extract and reconstruct, 2) extracting the geometry of the features using an isosurfacing technique, and 3) building the computational mesh from the extracted feature geometry. "Quantitative" image reconstruction and feature extraction is done for the purpose of generating computational meshes, not just for producing graphics "screen" quality images. For example, the surface geometry that we extract must from a closed water-tight surface. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Trease, L (reprint author), Pacific NW Natl Lab, POB 999,MS P7-51, Richland, WA 99352 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU ACTA PRESS ANAHEIM PI ANAHEIM PA PO BOX 5124, ANAHEIM, CA 92814-5124 USA SN 1482-7921 BN 978-0-88986-583-9 J9 IASTED INT CONF SIGN PY 2006 BP 335 EP 340 PG 6 WC Computer Science, Software Engineering; Imaging Science & Photographic Technology SC Computer Science; Imaging Science & Photographic Technology GA BFR52 UT WOS:000244029100059 ER PT J AU Zack, RS Ruiter, DE Strenge, DL Landour, PJ AF Zack, RS Ruiter, DE Strenge, DL Landour, PJ TI Adult caddisfly (Trichoptera) phenology at the Hanford Reach National Monument, Washington State SO PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON LA English DT Article DE Trichoptera; Hanford; survey; Washington state; caddisflies ID STREAMS AB Adult caddisflies were sampled on the Wahluke Wildlife Area and Saddle Mountain National Wildlife Refuge Subunits of the newly created (2000) Hanford Reach National Monument using 15-watt "black lights" from April 2002 through April 2003. A diverse fauna consisting of nine families,, 21 genera, and 33 species were collected. Protoptila coloma Ross, Agraylea multipunctata Curtis, Hydroptila xera Ross, Ceraclea alagma (Ross), Nectopsyche lahontanensis Haddock, Oecetis cinerascens (Hagen), and Ylodes reuteri (MacLachlan) represent new records for Washington State. Species composition and phenology are presented in tabular form. C1 Washington State Univ, Dept Entomol, James Entomol Collect, Pullman, WA 99164 USA. Battelle Pacific NW Natl Lab, Richland, WA 99352 USA. USDA ARS, Wapato, WA 98951 USA. RP Zack, RS (reprint author), Washington State Univ, Dept Entomol, James Entomol Collect, Pullman, WA 99164 USA. EM zack@wsu.edu; druiter@msn.com NR 13 TC 1 Z9 1 U1 2 U2 2 PU ENTOMOL SOC WASHINGTON PI WASHINGTON PA SMITHSONIAN INSTITUTION DEPT ENTOMOLOGY, WASHINGTON, DC 20560 USA SN 0013-8797 J9 P ENTOMOL SOC WASH JI Proc. Entomol. Soc. Wash. PD JAN PY 2006 VL 108 IS 1 BP 131 EP 138 PG 8 WC Entomology SC Entomology GA 001WA UT WOS:000234572200015 ER PT B AU Hertel, E Stewart, J AF Hertel, Eugene Stewart, James TI Model and code development in support of the portfolio for multiphase flow technology SO PROCEEDINGS OF THE HPCMP USERS GROUP CONFERENCE 2006 LA English DT Proceedings Paper CT Conference on High Performance Computer Modernization Program CY JUN 26-29, 2006 CL Denver, CO SP HPCMP Users Grp AB Modeling and Simulation of Weapon Systems and Munitions is a key enabler for exploring warfighting capability needs and system operational opportunities, and translating emergent technologies to robust, validated solutions that fill needed design spaces rather than provide point designs of limited relevance and durability. The intent is to increase the breadth and depth of system engineering and to explore and validate design spaces that are either untestable, too difficult to test, or too expensive, and time-consuming to test. The desired end state of this portfolio is an integrated toolkit capability encompassing the investments, discoveries, and inventions pertaining to future systems. The High Performance Computing Modernization Program Multiphase Flow Target Response (MFT) Portfolio will sharply advance the state-of-the-art in precision and completeness of how we develop weapon systems and munitions. The goal of the MFT response portfolio is to develop an integrated, coupled computational toolset for solving complex weapon systems problems where multiphase flow and realistic detonation chemistry are important. The MFT portfolio focuses on solving a class of complex system problems for non-traditional, advanced munitions, specifically multiphase blast explosives, and the subsequent target response. Increased performance of multiphase blast weapons over conventional weapons is attributed to the presence of solid particulates, either non-reactive or reactive, enhancing the blast wave and impulse. The result of this portfolio will be an enhanced capability to develop advanced munitions faster and at less cost by optimizing system designs computationally which may be validated experimentally. C1 [Hertel, Eugene; Stewart, James] Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RP Hertel, E (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM esherte@sandia.gov; jrstewa@sandia.gov FU United States Department of Energy's National Nuclear Security Administration [DE-AC04- 94AL85000] FX The authors would like to thank Dave Crawford, Arne Gullerud, Greg Sjaardema, Chris Bruner, Ray Bell, Paul DesJardin, and Greg Bessette for their contributions to the portfolio. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energys National Nuclear Security Administration under contract DE-AC04- 94AL85000. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 978-0-7695-2797-0 PY 2006 BP 102 EP 105 PG 4 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BGD48 UT WOS:000246173100015 ER PT B AU Kuhl, AL Khasainov, B Bell, J Beckner, V AF Kuhl, Allen L. Khasainov, Boris Bell, John Beckner, Vince TI Numerical simulation of the combustion of aluminum shock-dispersed-fuel charges SO PROCEEDINGS OF THE HPCMP USERS GROUP CONFERENCE 2006 LA English DT Proceedings Paper CT Conference on High Performance Computer Modernization Program CY JUN 26-29, 2006 CL Denver, CO SP HPCMP Users Grp C1 [Kuhl, Allen L.] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. [Khasainov, Boris] Lab Combust Deton, Futuroscope, France. [Bell, John; Beckner, Vince] Lawrence Berkeley Natl Lab, Berkeley, CA USA. RP Kuhl, AL (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM kuhl2@llnl.gov; boris.khasainov@lcd.ensma.fr; jbbell@lbl.gov; vebeckner@lbl.gov NR 12 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 978-0-7695-2797-0 PY 2006 BP 119 EP 123 PG 5 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BGD48 UT WOS:000246173100018 ER PT B AU Vacek, J Chocholousova, J Kobr, L Michl, J Miller, J AF Vacek, Jaroslav Chocholousova, Jana Kobr, Lukas Michl, Josef Miller, John TI Calculations of light-absorption driven molecular rotors SO PROCEEDINGS OF THE HPCMP USERS GROUP CONFERENCE 2006 LA English DT Proceedings Paper CT Conference on High Performance Computer Modernization Program CY JUN 26-29, 2006 CL Denver, CO SP HPCMP Users Grp ID DYNAMICS SIMULATIONS; ELECTRIC-FIELD; DIPOLAR; SURFACE AB We investigated the behavior of large molecular systems containing dipolar molecular rotors and motors. The computations, performed on the HPC computers, use the Universal Force Field and Newton equations of motion implemented in our customized molecular dynamics program TINK, and commercial ab initio quantum chemical programs. The purpose of these calculations is to design new materials with controllable surface friction, materials with nonlinear response to electric fields, and other interesting properties for future devices. At last year's conference we presented the principle of a fast unidirectional molecular rotor driven by absorption of light pulses. Now we outline results demonstrating the performance of an improved design of a synthetically accessible active motor molecule carrying a paddlewheel on a rotation axis. The structure has been optimized in a series of molecular dynamics simulations. It is designed in such a way that the absorption of a photon will cause the separation of charges, and their mutual attraction will then cause the rotor to make half a turn in the course of a few picoseconds. After about a dozen picoseconds after charge recombination the rotor completes a full turn. The structure has been designed in a way that favors unidirectional motion. The rates of charge separation and recombination can be controlled by a choice of donor and acceptor structures. With suitable choices, continuous irradiation or a train of light pulses would thus be expected to induce a fast unidirectional rotation of the rotor, which could be used to propel a thin layer of a fluid along a surface ("molecular pump's if the rotors were mounted in an organized array on a surface. C1 [Vacek, Jaroslav; Chocholousova, Jana; Kobr, Lukas] Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. [Miller, John] Brookhaven Natl Lab, Upton, NY USA. RP Vacek, J (reprint author), Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. EM vacek@eefus.colorado.edu; jana@eefus.colorado.edu; alexandr.prokop@marge.uochb.cas.cz; michl@eefus.colorado.edu; jrmiller@bnl.gov RI Vacek, Jaroslav/B-7216-2011; Vacek Chocholousova, Jana/B-6781-2011; Michl, Josef/G-9376-2014 OI Vacek, Jaroslav/0000-0002-2610-4444; Vacek Chocholousova, Jana/0000-0003-0391-6818; FU DoD High Performance Modernization Office Challenge project C1R, USARO [DAAD19-01-1-0521]; ARL-ERO [N62558-03-M-0806]; NSF [OISE-0532040]; EU-STRP [013880] FX This project was supported by the DoD High Performance Modernization Office Challenge project C1R, USARO (DAAD19-01-1-0521), ARL-ERO (N62558-03-M-0806), NSF (OISE-0532040) the EU-STRP 013880. NR 11 TC 4 Z9 4 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 978-0-7695-2797-0 PY 2006 BP 193 EP 196 PG 4 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BGD48 UT WOS:000246173100029 ER PT B AU McClean, JL Ivanova, D Carton, J Giese, B Hunke, E Maltrud, M AF McClean, Julie L. Ivanova, Detelina Carton, James Giese, Benjamin Hunke, Elizabeth Maltrud, Mathew TI Fine-resolution global sea-ice/ocean modeling and data assimilation SO PROCEEDINGS OF THE HPCMP USERS GROUP CONFERENCE 2006 LA English DT Proceedings Paper CT Conference on High Performance Computer Modernization Program CY JUN 26-29, 2006 CL Denver, CO SP HPCMP Users Grp ID UPPER OCEAN 1950-95; THICKNESS DISTRIBUTION; ICE THICKNESS; VARIABILITY; DYNAMICS C1 [McClean, Julie L.; Ivanova, Detelina] Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. [Giese, Benjamin] Texas A&M Univ, College Stn, TX USA. [Carton, James] Univ Maryland, College Pk, MD USA. [Hunke, Elizabeth; Maltrud, Mathew] Los Alamos Natl Lab, Los Alamos, NM USA. RP McClean, JL (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. EM mcclean@ucsd.edu; divanova@ucsd.edu; carton@atmos.umd.edu; b-giese@tamu.edu; eclare@lanl.gov; maltrud@lanl.gov NR 28 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 978-0-7695-2797-0 PY 2006 BP 275 EP 279 PG 5 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BGD48 UT WOS:000246173100041 ER PT B AU Bhatia, N Alam, SR Vetter, JS AF Bhatia, Nikhil Alam, Sadaf R. Vetter, Jeffrey S. TI Performance modeling of emerging HPC architectures SO PROCEEDINGS OF THE HPCMP USERS GROUP CONFERENCE 2006 LA English DT Proceedings Paper CT Conference on High Performance Computer Modernization Program CY JUN 26-29, 2006 CL Denver, CO SP HPCMP Users Grp AB Current state-of-art HPCMP performance modeling techniques primarily rely on combining a performance profile of an application on a well-known HPC architecture, and the machine characteristics of an emerging architecture to project an application's performance on the emerging architecture. Existing profiling and tracing tools on well-known architectures are topically used to collect the necessary performance data by executing applications and benchmarks on available systems. Since the performance enhancing features of novel processing devices may be significantly different from a conventional microprocessor system, current performance modeling schemes have limited applicability on systems like the Cray X1E vector supercomputer and parallel systems with accelerator devices like Cray XD1, which contains FPGAs. We employ an application modeling paradigm that allows a user to develop not only "architecture aware" but also "application aware" performance models. We extend the Modeling Assertions (MA) framework that permits a user to develop multi-resolution, parameterized symbolic models. We demonstrate the application of our modeling scheme by augmenting the MA models with performance enhancing attributes of the Cray X1E Multistreaming Processors (MSPs). Using the extended M framework, we develop symbolic performance models of critical code blocks of an HPCMP TI-06 benchmark called HYCOM-an ocean modeling code. By representing the code characteristics of the critical code blocks in terms of both unique architectural attributes and key input parameters of the HYCOM application, we manage to reduce and sustain performance prediction error rates to less than 30%. C1 [Bhatia, Nikhil; Alam, Sadaf R.; Vetter, Jeffrey S.] Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. RP Bhatia, N (reprint author), Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. EM bhatia@oml.gov; alamsr@oml.gov; vetter@oml.gov FU DoD; US Government [DE-AC0500OR22725] FX We gratefully acknowledge financial support of the DoD High Performance Computing Modernization Program. The submitted manuscript has been authored by a contractor of the US Government under Contract No. DE-AC0500OR22725. Accordingly, the US Government retains a non-exclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US Government purposes. NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 978-0-7695-2797-0 PY 2006 BP 367 EP 373 PG 7 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BGD48 UT WOS:000246173100056 ER PT B AU Chen, H Decker, J Bierbaum, N AF Chen, H Decker, J Bierbaum, N BE Fahringer, T TI Future networking for scalable I/O SO Proceedings of the IASTED International Conference on Parallel and Distributed Computing and Networks LA English DT Proceedings Paper CT IASTED International Conference on Parallel and Distributed Computing and Networks CY FEB 14-16, 2006 CL Innsbruck, AUSTRIA SP IASTED DE InfiniBand; 10GbE; TOE; parallel I/O; cluster; HPC AB Large clustered computers provide low-cost compute cycles, and therefore have promoted the development of sophisticated parallel-programming algorithms based on the Message Passing Interface. Storage platforms, however, fall to keep pace with similar advances. This paper compares standard 4X InfiniBand (IB) to 10-Gigabit Ethernet (GbE) for Use as a common storage infrastructure in addition to message passing. Considering IB's native ability to accelerate protocol processing in hardware, the Ethernet hardware in this study provided similar acceleration using TCP Offload Engines. We evaluated their I/O perfon-nance using the IOZONE benchmark on the iSCSI-based TerraGRID parallel filesystem. Our evaluations show that 10GbE, with or without protocol-offload, offered better throughput and latency than IB to socket-based applications. Although protocol-offload in both 10GbE and IB demonstrated significant improvement in I/O performance, large amount of CPU are still being consumed to handle the associated data-copies and interrupts. The emerging RDMA technologies hold promises to remove the remaining CPU overhead. We plan to continue our study to research the applications of RDMA in parallel I/O. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Chen, H (reprint author), Sandia Natl Labs, POB 969, Livermore, CA 94550 USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU ACTA PRESS PI CALGARY PA B6, STE 101, 2509 DIEPPE AVE SW, CALGARY, ALBERTA T3E 7J9, CANADA BN 0-88986-568-X PY 2006 BP 128 EP 135 PG 8 WC Computer Science, Theory & Methods SC Computer Science GA BEA02 UT WOS:000236386800021 ER PT B AU Murphy, R Berry, J McLendon, W Hendrickson, B Gregor, D Lumsdaine, A AF Murphy, Richard Berry, Jonathan McLendon, William Hendrickson, Bruce Gregor, Douglas Lumsdaine, Andrew GP IEEE TI DFS: A simple to write yet difficult to execute benchmark SO PROCEEDINGS OF THE IEEE INTERNATIONAL SYMPOSIUM ON WORKLOAD CHARACTERIZATION SE International Symposium on Workload Characterization Proceedings LA English DT Proceedings Paper CT IEEE International Symposium on Workload Characterization CY OCT 25-27, 2006 CL San Jose, CA SP IEEE Comp Soc, TCCA, Google, Intel, IBM Res, Texas Instruments C1 [Murphy, Richard; Berry, Jonathan; McLendon, William; Hendrickson, Bruce] Sandia Natl Labs, POB 5800,MS-1110, Albuquerque, NM 87185 USA. [Gregor, Douglas; Lumsdaine, Andrew] Indiana Univ, Dept CSE, Bloomington, IN 47405 USA. RP Murphy, R (reprint author), Sandia Natl Labs, POB 5800,MS-1110, Albuquerque, NM 87185 USA. EM rcmurph@sandia.gov; jberry@sandia.gov; mcwclen@sandia.gov; bahendr@sandia.gov; dgregor@cs.indiana.edu; lums@cs.indiana.edu NR 5 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 1-4244-0508-4 J9 I S WORKL CHAR PROC PY 2006 BP 175 EP + PG 2 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BFL13 UT WOS:000242576000017 ER PT B AU Alam, SR Barrett, RF Kuehn, JA Roth, PC Vetter, JS AF Alam, Sadaf R. Barrett, Richard F. Kuehn, Jeffery A. Roth, Philip C. Vetter, Jeffrey S. GP IEEE TI Characterization of scientific workloads on systems with multi-core processors SO PROCEEDINGS OF THE IEEE INTERNATIONAL SYMPOSIUM ON WORKLOAD CHARACTERIZATION SE International Symposium on Workload Characterization Proceedings LA English DT Proceedings Paper CT IEEE International Symposium on Workload Characterization CY OCT 25-27, 2006 CL San Jose, CA SP IEEE Comp Soc, TCCA, Google, Intel, IBM Res, Texas Instruments DE performance characterization; multi-core processor; AMD opteron; micro-benchmarking; scientific applications AB Multi-core processors are planned for virtually all next-generation HPC systems. In a preliminary evaluation of AMD Opteron Dual-Core processor systems, we investigated the scaling behavior of a set of micro-benchmarks, kernels, and applications. In addition, we evaluated a number of processor affinity techniques for managing memory placement on these multi-core systems. We discovered that an appropriate selection of MPI task and memory placement schemes can result in over 25% performance improvement for key scientific calculations. We collected detailed performance data for several large-scale scientific applications. Analyses of the application performance results confirmed our micro-benchmark and scaling results. C1 [Alam, Sadaf R.; Barrett, Richard F.; Kuehn, Jeffery A.; Roth, Philip C.; Vetter, Jeffrey S.] Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. RP Alam, SR (reprint author), Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. EM alamsr@ornl.gov; rbarrett@ornl.gov; kuehn@ornl.gov; rothpc@ornl.gov; vetter@ornl.gov NR 8 TC 9 Z9 9 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 1-4244-0508-4 J9 I S WORKL CHAR PROC PY 2006 BP 225 EP + PG 2 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BFL13 UT WOS:000242576000023 ER PT B AU Bagherjeiran, A Kamath, C AF Bagherjeiran, Abraham Kamath, Chandrika BE Ghosh, J Lambert, D Skillicorn, D Srivastava, J TI Graph-based Methods for Orbit Classification SO PROCEEDINGS OF THE SIXTH SIAM INTERNATIONAL CONFERENCE ON DATA MINING SE SIAM Proceedings Series LA English DT Proceedings Paper CT 6th SIAM International Conference on Data Mining CY APR 20-22, 2006 CL Bethesda, MD SP Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Amer Stat Assoc DE orbit; Poincare plot; classification AB An important step in the quest for low-cost fusion power is the ability to perform and analyze experiments in prototype fusion reactors. One of the tasks in the analysis is the classification of orbits in Poincare plots generated by the particles in a fusion reactor as they move within the toroidal device. In this paper, we describe the use of graph-based methods to extract features from orbits. These features are then used to classify the orbits into several categories. Our results show that existing machine learning algorithms are successful in classifying orbits with few points, a situation which can arise in data from experiments. C1 [Bagherjeiran, Abraham; Kamath, Chandrika] Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA USA. RP Bagherjeiran, A (reprint author), Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA USA. NR 7 TC 4 Z9 4 U1 0 U2 1 PU SIAM PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA BN 978-0-89871-611-5 J9 SIAM PROC S PY 2006 BP 574 EP 578 PG 5 WC Computer Science, Artificial Intelligence SC Computer Science GA BUJ09 UT WOS:000289491100063 ER PT B AU Thien, AB Pluckett, AD Park, G Farrar, CR AF Thien, A. B. Pluckett, A. D. Park, G. Farrar, C. R. BE Guemes, A TI Detecting and locating cracks and corrosion in pipes using ultrasonic guided waves SO PROCEEDINGS OF THE THIRD EUROPEAN WORKSHOP STRUCTURAL HEALTH MONITORING 2006 SE Structural Health Monitoring (SHM) LA English DT Proceedings Paper CT 3rd European Workshop on Structural Health Monitoring CY JUL 05-07, 2006 CL Granada, SPAIN SP Minist Espanol Educ & Ciencia, AIBUS Espana, BOEING Res & Technol Ctr Europe, Univ Politecn Madrid, Univ Granada, Ayuntamiento Granada ID LAMB WAVES; REFLECTION; INSPECTION; NOTCHES AB Harsh environmental and operating conditions often leave pipeline systems prone to cracks, corrosion, and other aging defects. If left undetected, these forms of damage can lead to the failure of the pipeline system, which may have catastrophic consequences. Most current forms of health monitoring for pipeline systems involve nondestructive evaluation (NDE) techniques. These techniques often require a pipeline system to be taken out of operation at regularly scheduled intervals so that a technician can perform a prescribed NDE measurement. Such a measurement also requires direct access to the pipe's exterior or interior surface. This access may require excavation if the pipe is underground and the removal of insulating layers when present. This research proposes the use of Macro-fiber composite (MFC) actuators for damage detection in pipeline structures. Because MFC actuators are durable and relatively inexpensive, they can be permanently bonded to the surface of a pipe during installation. Therefore, measurements for damage detection can be performed at any time, even while the system is in operation. Experimental results demonstrate the capability of the proposed methods to identify the presence of damage and detect its location. The procedures involve active sensing in which an array of MFC patches is used to excite Lamb waves in the structure and measure the corresponding responses. Several forms of damage typically found in pipelines are examined and the conclusions are presented. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Thien, AB (reprint author), Los Alamos Natl Lab, MS T001, Los Alamos, NM 87545 USA. RI Farrar, Charles/C-6954-2012 NR 10 TC 0 Z9 0 U1 0 U2 2 PU DESTECH PUBLICATIONS, INC PI LANCASTER PA 439 DUKE STREET, LANCASTER, PA 17602-4967 USA BN 978-1-932078-63-3 J9 STRUCT HLTH MONIT PY 2006 BP 1045 EP 1053 PG 9 WC Engineering, Aerospace; Engineering, Civil; Engineering, Mechanical; Telecommunications SC Engineering; Telecommunications GA BFY89 UT WOS:000245497300128 ER PT J AU Oefelein, JC AF Oefelein, Joseph C. TI Large eddy simulation of turbulent combustion processes in propulsion and power systems SO PROGRESS IN AEROSPACE SCIENCES LA English DT Review ID CONDITIONAL MOMENT CLOSURE; FILTERED DENSITY-FUNCTION; SUBGRID-SCALE MODEL; DISPERSED SOLID PARTICLES; NAVIER-STOKES EQUATIONS; NITRIC-OXIDE FORMATION; JET DIFFUSION FLAME; NUMERICAL ERRORS; PREMIXED FLAMES; REACTING FLOWS AB Progress toward application of the large eddy simulation (LES) technique to turbulent multiphase combustion processes is presented with emphasis placed on propulsion and power systems. The primary objective is to provide a systematic analysis of the current state-of-the-art and assist in the development of technical performance metrics for model development and validation. Research is currently required to provide both improved multiphase combustion models and improved datasets for validation. Requirements for further model development must be established through detailed analyses of the space-time characteristics of small-scale flame structures and turbulence-chemistry interactions. Concurrently, a refined set of implementation requirements must be established. Steps taken towards these goals are described by first providing a generalized formulation of the filtered conservation equations using an arbitrary filter function that operates on both spatial and temporal scales, with no a priori assumptions made regarding the character of the multiphase fluid elements present in the system. The distinct requirements for LES are listed with a discussion that highlights current progress and unresolved issues. Two case studies are then presented that demonstrate the predictive capabilities of LES when implemented with the appropriate numerics and grid resolution, under highly controlled conditions, and with well-defined boundary conditions. The paper is concluded by highlighting recent findings associated with the International Workshop on Measurement and Computation of Turbulent Nonpremixed Flames. (c) 2006 Elsevier Ltd. All rights reserved. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Oefelein, JC (reprint author), Sandia Natl Labs, Combust Res Facil, POB 969,7011 East Ave,Mail Stop 9051, Livermore, CA 94551 USA. EM oefelei@sandia.gov NR 121 TC 49 Z9 51 U1 4 U2 16 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0376-0421 J9 PROG AEROSP SCI JI Prog. Aeosp. Sci. PD JAN PY 2006 VL 42 IS 1 BP 2 EP 37 DI 10.1016/j.paerosci.2006.02.001 PG 36 WC Engineering, Aerospace SC Engineering GA 062CM UT WOS:000238922100002 ER PT S AU Yiotis, AG Stubos, AK Boudouvis, AG Tsimpanogiannis, IN Yortsos, YC AF Yiotis, AG Stubos, AK Boudouvis, AG Tsimpanogiannis, IN Yortsos, YC BE DiBucchianico, A Mattheij, RMM Peletier, MA TI Modeling of drying processes in pore networks SO PROGRESS IN INDUSTRIAL MATHEMATICS AT ECMI 2004 SE Mathematics in Industry LA English DT Proceedings Paper CT 13th European Symposium on Mathematics in Industry (ESMI) CY JUN 21-25, 2004 CL Eindhoven, NETHERLANDS ID CAPILLARY-POROUS MEDIA AB Drying in porous structures is simulated with a 2-D pore network model that accounts for various processes at the pore-scale (mass transfer by advection and diffusion in the gas phase, viscous flow in liquid and gas phases and capillary effects at the gas-liquid interface). We further study the effect of capillarity-driven viscous flow through macroscopic liquid films. It is shown that film flow is a major transport mechanism in drying of porous media, its effect being dominant when capillarity controls the process, which is the case in typical applications. C1 Natl Ctr Sci Res Demokritos, Athens 15310, Greece. Natl Tech Univ Athens, Sch Chem Engn, Athens 15780, Greece. Los Alamos Natl Lab, Earth & Environm Sci Div, Los Alamos, NM 87545 USA. Univ So Calif, Dept Chem Engn, Los Angeles, CA 90089 USA. RP Natl Ctr Sci Res Demokritos, Athens 15310, Greece. NR 6 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 1612-3956 BN 3-540-28072-3 J9 MATH INDUST PY 2006 VL 8 BP 293 EP + PG 6 WC Mathematics, Applied SC Mathematics GA BDR24 UT WOS:000235037100046 ER PT J AU Favorite, JA AF Favorite, JA TI A four-group analytic rod transport problem for (n, y) and (n, n ' y) verification SO PROGRESS IN NUCLEAR ENERGY LA English DT Article DE analytic transport solution; analytic benchmark; rod problem; forward-backward model; adjoint transport equation ID RADIATIVE-TRANSFER AB Forward and adjoint transport problems are solved analytically on a homogeneous rod (the forward-backward model) with four energy groups. Groups 1 and 2 represent fast and thermal neutrons-, groups 3 and 4 represent gamma rays born from thermal neutron capture and fast neutron inelastic scattering, respectively. Neutron scattering includes self-scattering and downscattering. There is no fission. Gamma rays are treated as lines, so gamma-ray scattering is ignored. Neutron scattering and gamma production are isotropic. In the forward problem, there are neutron sources incoming at the rod endpoints but no internal neutron sources; there are no extrinsic gamma sources. In the adjoint problem, there are garmma detectors at the rod endpoints but no neutron detectors anywhere. PARTISN results agree to seven significant figures with the analytic results in a numerical benchmark problem using. hydrogen and carbon. The equivalence among the rod transport problem, diffusion theory, and the S-2 discrete ordinates method is demonstrated for didactic purposes. (c) 2005 Elsevier Ltd. All rights reserved. C1 Los Alamos Natl Lab, Diagnost Applicat Grp X5, Los Alamos, NM 87545 USA. RP Favorite, JA (reprint author), Los Alamos Natl Lab, Diagnost Applicat Grp X5, MS F663, Los Alamos, NM 87545 USA. EM fave@lanl.gov NR 7 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0149-1970 J9 PROG NUCL ENERG JI Prog. Nucl. Energy PY 2006 VL 48 IS 2 BP 103 EP 134 DI 10.1016/j.pnucene.2005.03.018 PG 32 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 012DS UT WOS:000235319000002 ER PT J AU Trellue, HR AF Trellue, HR TI Safety and neutronics: A comparison of MOX vs UO2 fuel SO PROGRESS IN NUCLEAR ENERGY LA English DT Article DE MOX fuel; spent fuel; irradiation calculations with monteburns; full cores of MOX; extra-moderated assembly ID PLUTONIUM; TRANSMUTATION; REACTORS; CORES AB One of the issues associated with nuclear energy involves determining what should be done with spent nuclear fuel. In other countries, plutonium is recovered from spent fuel and is burned in reactors. Plutonium is not used currently as a fuel in the United States (US); however, as part of international negotiations, weapons-grade plutonium may soon be burned in US light-water reactors as mixed oxide (MOX) fuel. Both neutronic and safety parameters for MOX fuel vary from traditional uranium oxide (UO2) fuel, so it is important to be aware of these variances. Differences between weapons-grade plutonium and plutonium from spent nuclear fuel (reactor-grade plutonium) also exist because reactor-grade plutonium contains more Pu-240 and higher actinides. To burn a significant portion of plutonium from spent nuclear fuel using full cores of MOX fuel would be advantageous; however, only one-third cores are being used today worldwide and are proposed for the Materials Disposition program in the US. This paper addresses the neutronic and safety differences between UO2 and MOX fuel (with both weapons- and reactor-grade plutonium) and between one-third and full cores of MOX fuel. Published by Elsevier Ltd. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Trellue, HR (reprint author), Los Alamos Natl Lab, POB 1663,MS K575, Los Alamos, NM 87545 USA. EM trellue@lanl.gov NR 27 TC 10 Z9 13 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0149-1970 J9 PROG NUCL ENERG JI Prog. Nucl. Energy PY 2006 VL 48 IS 2 BP 135 EP 145 DI 10.1016/j.pnucene.2005.04.003 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 012DS UT WOS:000235319000003 ER PT J AU Lewis, EE Smith, MA Na, BC AF Lewis, Elmer E. Smith, Micheal A. Na, Byung-Chan TI Special issue: OECD/NEA C5G7 MOX benchmark: 3-D extension case - Preface SO PROGRESS IN NUCLEAR ENERGY LA English DT Editorial Material C1 OECD Nucl Energy Agcy, F-92130 Issy Les Moulineaux, France. Northwestern Univ, Evanston, IL 60208 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Na, BC (reprint author), OECD Nucl Energy Agcy, 12 Bd Iles, F-92130 Issy Les Moulineaux, France. EM byung-chan.na@oecd.org RI Lewis, Elmer/B-7597-2009 NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0149-1970 J9 PROG NUCL ENERG JI Prog. Nucl. Energy PY 2006 VL 48 IS 5 BP 381 EP 382 DI 10.1016/j.pnucene.2006.01.001 PG 2 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 072TN UT WOS:000239696000001 ER PT J AU Smith, MA Lewis, EE Na, BC AF Smith, M. A. Lewis, E. E. Na, Byung-Chan TI Benchmark on deterministic 3-D MOX fuel assembly transport calculations without spatial homogenization SO PROGRESS IN NUCLEAR ENERGY LA English DT Article DE OECD/NEA; 3-D Expert Group; MOX assembly; three-dimensional transport benchmark; no spatial homogenization AB Within the framework of the OECD/NEA Expert Group on 3-D Radiation Transport Benchmarks, an international benchmark exercise for testing the ability of modem deterministic transport methods and codes to treat reactor problems without spatial homogenization was proposed in March 2001. That benchmark was completed in 2003 and the OECD report is available. As a follow-up to that benchmark, an extension of the 3-D calculations was proposed in May 2003 to provide a more challenging test of present day three-dimensional methods' ability to handle spatial homogeneities. Control rods were introduced, adding to the heterogeneity of the problems. The reactor core size was decreased to reduce the computational burden on all participants. Fourteen solutions were submitted for the new benchmark by 12 participants. All of the participant solutions were compared to a reference multigroup Monte Carlo solution. The analysis of results shows modern deterministic transport codes and methods can calculate the flux distribution reasonably well without relying upon spatial homogenization techniques, provided the domain size is small enough that the problem can be performed on available computing equipment. (C) 2006 Elsevier Ltd. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Northwestern Univ, Dept Mech Engn, Evanston, IL 60208 USA. OECD, NEA, F-92130 Issy Les Moulineaux, France. RP Smith, MA (reprint author), Argonne Natl Lab, Bldg 208,Rm L102,9700 S Cass Ave, Argonne, IL 60439 USA. EM masmith@ra.anl.gov RI Lewis, Elmer/B-7597-2009 NR 11 TC 4 Z9 4 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0149-1970 J9 PROG NUCL ENERG JI Prog. Nucl. Energy PY 2006 VL 48 IS 5 BP 383 EP 393 DI 10.1016/j.pnucene.2006.01.002 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 072TN UT WOS:000239696000002 ER PT J AU Dahl, JA AF Dahl, Jon A. TI PARTISN results for the OECD/NEA 3-D extension C5G7 MOX benchmark SO PROGRESS IN NUCLEAR ENERGY LA English DT Article DE C5G7; MOX; benchmark; PARTISN; discrete ordinates AB We have participated in the Expert Group on 3-D Radiation Transport Benchmarks' 3-D Extension C5G7 MOX problems using the discrete ordinate transport code PARTISN. The computational mesh was created using the FRAC-IN-THE-BOX code, which produces a volume fraction Cartesian mesh from combinatorial geometry descriptions. k(eff) eigenvalues, maximum pin powers, and average fuel assembly powers are reported and compared to an MCNP(TM) (MCNP is a trademark of the Regents of the University of California, Los Alamos National Laboratory) reference solution. We also present a two-dimensional mesh convergence study examining the affects of using volume fractions to approximate the water-pin cell interface. It is noted that the previous PARTISN results provided to the OECD/NEA Expert Group on 3-D Radiation Benchmarks contained a cross-section error, and therefore should be disregarded. (C) 2006 Elsevier Ltd. All rights reserved. C1 Los Alamos Natl Lab, Trnasport Methods Grp CCS4, Los Alamos, NM 87545 USA. RP Dahl, JA (reprint author), Los Alamos Natl Lab, Trnasport Methods Grp CCS4, POB 1663, Los Alamos, NM 87545 USA. EM dahl@lanl.gov NR 8 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0149-1970 J9 PROG NUCL ENERG JI Prog. Nucl. Energy PY 2006 VL 48 IS 5 BP 401 EP 409 DI 10.1016/j.pnucene.2006.01.003 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 072TN UT WOS:000239696000004 ER PT J AU Klingensmith, JJ Azmy, YY Gehin, JC Orsi, R AF Klingensmith, Jesse J. Azmy, Yousry Y. Gehin, Jess C. Orsi, Roberto TI Tort solutions to the three-dimensional MOX benchmark, 3-D Extension C5G7MOX SO PROGRESS IN NUCLEAR ENERGY LA English DT Article DE TORT; discrete-ordinates; C5G7MOX benchmark; multiplication factor; pin power distribution AB Solutions to the OECD/NEA three-dimensional fuel assembly benchmark problem, C5G7MOX, obtained using the discrete-ordinates neutron transport code TORT are presented. The accuracy and convergence of the effective multiplication factor and maximum pin power are examined while varying the fidelity of the geometric model and the order of the angular quadrature, specifically the Square Legendre-Chebychev quadrature. The calculated value of the effective multiplication factor is shown to converge asymptotically as the order of the quadrature is increased. The behavior of that asymptotic limit of k(eff) with decreasing computational cell size and increasing staircase resolution of the curved rod-moderator is less converged. Moreover, rapidly increasing computational cost with geometric configuration refinement prevented us from achieving asymptotic convergence with the spatial approximation. The maximum pin power results are generally shown to asymptotically converge to within the statistical error of the reference solution for the problem slices where control rods are not present. For the zones that contain control rods, the solution does not appear to be tightly converged for the meshes and quadrature orders employed. (C) 2006 Elsevier Ltd. All rights reserved. C1 Penn State Univ, University Pk, PA 16802 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. ENEA Ctr Dati Nucl, I-40129 Bologna, Italy. RP Klingensmith, JJ (reprint author), Penn State Univ, 126 Hammond Bldg, University Pk, PA 16802 USA. EM jxk390@psu.edu; yya3@psu.edu; gehinjc@ornl.gov; orsi@bologna.enea.it RI Gehin, Jess/E-2560-2011; OI Gehin, Jess/0000-0001-8337-9551 NR 7 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0149-1970 J9 PROG NUCL ENERG JI Prog. Nucl. Energy PY 2006 VL 48 IS 5 BP 445 EP 455 DI 10.1016/j.pnucene.2006.01.011 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 072TN UT WOS:000239696000009 ER PT S AU Epelbaum, E AF Epelbaum, Evgeny BE Faessler, A TI Few-nucleon forces and systems in chiral effective field theory SO PROGRESS IN PARTICLE AND NUCLEAR PHYSICS, VOL 57, NO 2 SE Progress in Particle and Nuclear Physics LA English DT Article DE effective field theory; chiral perturbation theory; nuclear forces; few-nucleon systems; isospin-violating effects; chiral extrapolations ID PROTON-PROTON SCATTERING; SHORT-RANGE FORCES; ONE-PION-EXCHANGE; NEUTRON-DEUTERON SCATTERING; MONTE-CARLO CALCULATIONS; DEPENDENT 3-BODY FORCE; PARTIAL-WAVE ANALYSIS; PHASE-SHIFT ANALYSIS; LOW-ENERGY THEOREMS; ASYMPTOTIC D-STATE AB We outline the structure of the nuclear force in the framework of chiral effective field theory of QCD and review recent applications to processes involving few nucleons. (c) 2005 Elsevier B.V. All rights reserved. C1 Jefferson Lab, Theory Div, Newport News, VA 23606 USA. RP Epelbaum, E (reprint author), Jefferson Lab, Theory Div, Newport News, VA 23606 USA. EM epelbaum@jlab.org NR 354 TC 380 Z9 382 U1 2 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0146-6410 J9 PROG PART NUCL PHYS PY 2006 VL 57 IS 2 BP 654 EP 741 DI 10.1016/j.ppnp.2005.09.002 PG 88 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA BFF25 UT WOS:000241575800004 ER PT S AU Stone, JR Reinhard, PG AF Stone, J. R. Reinhard, P. -G. BE Faessler, A TI The Skyrme interaction in finite nuclei and nuclear matter SO PROGRESS IN PARTICLE AND NUCLEAR PHYSICS, VOL 58, NO 2 SE Progress in Particle and Nuclear Physics LA English DT Review DE nuclea mean-field models; Sykrme forces; equation of state and stellar matter; neutron stars ID MEAN-FIELD-THEORY; GENERATOR-COORDINATE METHOD; EQUATION-OF-STATE; HARTREE-FOCK CALCULATIONS; SELF-CONSISTENT CALCULATION; NEUTRON-RICH NUCLEI; GROUND-STATE; R-PROCESS; GIANT-RESONANCES; MASS FORMULA AB Self-consistent mean field models are a powerful tool in the investigation of nuclear structure and low-energy dynamics. They are based on effective energy-density functionals, often formulated in terms of effective density-dependent nucleon-nucleon interactions. The free parameters of the functional are adjusted to empirical data. A proper choice of these parameters requires a comprehensive set of constraints covering experimental data on finite nuclei, concerning static as well as dynamical properties, empirical characteristics of nuclear matter, and observational information on nucleosynthesis, neutron stars and supernovae. This work aims at a comprehensive survey of the performance of one of the most successful non-relativistic self-consistent method, the Skyrme-Hartree-Fock model (SHF), with respect to these constraints. A full description of the Skyrme functional is given and its relation to other effective interactions is discussed. The validity of the application of SHF far from stability and in dense environments beyond the nuclear saturation density is critically assessed. The use of SHF in models extended beyond the mean field approximation by including some correlations, is discussed. Finally, future prospects for further development of SHF towards a more consistent application of the existing and promising newly developing constraints are outlined. (c) 2006 Elsevier B.V. All rights reserved. C1 Univ Erlangen Nurnberg, Inst Theoret Phys, D-91054 Erlangen, Germany. Univ Oxford, Dept Phys, Oxford OX1 3PU, England. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. Oak Ridge Natl Lab, Joint Inst HEavy Ion, Oak Ridge, TN 37831 USA. RP Reinhard, PG (reprint author), Univ Erlangen Nurnberg, Inst Theoret Phys, D-91054 Erlangen, Germany. EM reinhard@theorie2.physik.uni-erlangen.de NR 282 TC 3 Z9 3 U1 2 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0146-6410 J9 PROG PART NUCL PHYS PY 2006 VL 58 IS 2 BP 587 EP 657 DI 10.1016/j.ppnp.2006.07.001 PG 71 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA BFV67 UT WOS:000244889500005 ER PT J AU Repins, IL Stanbery, BJ Young, DL Li, SS Metzger, WK Perkins, CL Shafarman, WN Beck, ME Chen, L Kapur, VK Tarrant, D Gonzalez, MD Jensen, DG Anderson, TJ Wang, X Kerr, LL Keyes, B Asher, S Delahoy, A Von Roedern, B AF Repins, IL Stanbery, BJ Young, DL Li, SS Metzger, WK Perkins, CL Shafarman, WN Beck, ME Chen, L Kapur, VK Tarrant, D Gonzalez, MD Jensen, DG Anderson, TJ Wang, X Kerr, LL Keyes, B Asher, S Delahoy, A Von Roedern, B TI Comparison of device performance and measured transport parameters in widely-varying Cu(In, Ga) (Se, S) solar cells SO PROGRESS IN PHOTOVOLTAICS LA English DT Article DE CIGSS; transport; characterization; correlation; thin-film photovoltaics ID ELECTRONIC-PROPERTIES; THIN-FILMS; BAND-GAP; CU(IN,GA)SE-2; EFFICIENCY; CAPACITANCE; HETEROJUNCTIONS; RECOMBINATION; CUIN1-XGAXSE2; SPECTROSCOPY AB We report the results of an extensive study employing numerous methods to characterize carrier transport within copper indium gallium sulfoselenide (CIGSS) photovoltaic devices, whose absorber layers were fabricated by diverse process methods in multiple laboratories. This collection of samples exhibits a wide variation of morphologies, compositions, and solar power conversion efficiencies. An extensive characterization of transport properties is reported here-including those derived from capacitance-voltage, admittance spectroscopy, deep level transient spectroscopy, time-resolved photoluminescence, Auger emission profiling, Hall effect, and drive level capacitance profiling. Data from each technique were examined for correlation with device performance, and those providing indicators of related properties were compared to determine which techniques and interpretations provide credible values for transport properties. Although these transport properties are not sufficient to predict all aspects of current-voltage characteristics, we have identified specific physical and transport characterization methods that can be combined using a model-based analysis algorithm to provide a quantitative prediction of voltage loss within the absorber. The approach has potential as a tool to optimize and understand device performance irrespective of the specific process used to fabricate the CIGSS absorber layer. Copyright 2005 John Wiley & Sons, Ltd. C1 ITN Energy Syst, Littleton, CO 80127 USA. HelioVolt Corp, Austin, TX 78746 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Florida, Gainesville, FL 32611 USA. Univ Delaware, Inst Energy Convers, Newark, DE 19716 USA. Global Solar Energy Inc, Tucson, AZ 85747 USA. Energy Photovolta Inc, Trenton, NJ 08648 USA. Int Solar Elect Technol, Inglewwod, CA 90301 USA. Shell Solar Ind, Camarillo, CA 93012 USA. RP Repins, IL (reprint author), ITN Energy Syst, 8130 Shaffer Pkwy, Littleton, CO 80127 USA. EM supervacuo@aol.com NR 48 TC 44 Z9 44 U1 0 U2 30 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 1062-7995 J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD JAN PY 2006 VL 14 IS 1 BP 25 EP 43 DI 10.1002/pip.654 PG 19 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 006CN UT WOS:000234872800003 ER PT J AU Green, MA Emery, K King, DL Hisikawa, Y Warta, W AF Green, MA Emery, K King, DL Hisikawa, Y Warta, W TI Solar cell efficiency tables (Version 27) SO PROGRESS IN PHOTOVOLTAICS LA English DT Article DE solar cell efficiency; photovoltaic efficiency; energy conversion efficiency AB Consolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined and new entries since July, 2005 are reviewed. Copyright (c) 2006 John Wiley & Sons, Ltd. C1 Univ New S Wales, Ctr Photovolt Engn, Sydney, NSW 2052, Australia. Natl Renewable Energy Lab, Golden, CO 80401 USA. Sandia Natl Labs, Albuquerque, NM 87123 USA. Natl Inst Adv Ind Sci & Technol, RCPV, Tsukuba, Ibaraki, Japan. Fraunhofer Inst Solar Energy Syst, Dept Solar Cells Mat & Technol, D-79110 Freiburg, Germany. RP Green, MA (reprint author), Univ New S Wales, Ctr Photovolt Engn, Sydney, NSW 2052, Australia. EM m.green@unsw.edu.au NR 48 TC 69 Z9 71 U1 2 U2 22 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1062-7995 J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD JAN PY 2006 VL 14 IS 1 BP 45 EP 51 DI 10.1002/pip.686 PG 7 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 006CN UT WOS:000234872800004 ER PT S AU Johnston, SW Kurtz, SR Crandall, RS AF Johnston, Steven W. Kurtz, Sarah R. Crandall, Richard S. BE Olafsen, LJ Biefeld, RM Wanke, MC Saxler, AW TI Characterization of a dominant electron trap in GaNAs using deep-level transient spectroscopy SO Progress in Semiconductor Materials V-Novel Materials and Electronic and Optoelectronic Applications SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Progress in Semiconductor Materials V held at the 2005 MRS Fall Meeting CY NOV 28-DEC 01, 2005 CL Boston, MA SP Mat Res Soc, AIXTRON Inc, Epichem Inc, NREL, Veeco TurboDisc ID MOLECULAR-BEAM EPITAXY; P-TYPE; SOLAR-CELLS; SEMICONDUCTORS; INGAASN; GAAS AB Dilute-nitrogen GaNAs epitaxial layers grown by metal-organic chemical vapor deposition were characterized by deep-level transient spectroscopy (DLTS). For all samples, the dominant DLTS signal corresponds to an electron trap having an activation energy of about 0.25 to 0.35 eV. The minority-carrier trap density in the p-type material is quantified based on computer simulation of the devices. The simulations show that only about 2% of the traps in the depleted layer are filled during the transient. The fraction of the traps that are filled depends strongly on the depth of the trap, but only weakly on the doping of the layers and on the conduction-band offset. The simulations provide a pathway to obtain semi-quantitative data for analysis of minority-carrier traps by DLTS. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Johnston, SW (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 14 TC 0 Z9 0 U1 0 U2 5 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-845-4 J9 MATER RES SOC SYMP P PY 2006 VL 891 BP 521 EP 526 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Ceramics; Materials Science, Multidisciplinary; Optics; Physics, Condensed Matter SC Engineering; Materials Science; Optics; Physics GA BEU31 UT WOS:000239521000080 ER PT J AU Rodriguez, JA AF Rodriguez, JA TI The chemical properties of bimetallic surfaces: Importance of ensemble and electronic effects in the adsorption of sulfur and SO2 SO PROGRESS IN SURFACE SCIENCE LA English DT Review DE sulfur; sulfur dioxide; bimetallic surfaces; catalyst poisoning; hydrodesulfurization ID TRANSITION-METAL SULFIDES; X-RAY-ABSORPTION; RU-AU CATALYSTS; PROMOTED SULFIDATION; REPULSIVE INTERACTIONS; AG/PT(111) SURFACES; HYDROGEN-SULFIDE; SYNERGIC SYSTEMS; CRYSTAL-SURFACES; NOBLE-METALS AB The understanding of the interaction of sulfur with bimetallic surfaces is a critical issue for preventing the deactivation of hydrocarbon reforming catalysts and for the design of better hydrodesulfurization catalysts. The alloying or combination of two metals can lead to materials with special chemical properties due to an interplay of "ensemble" and "electronic" effects. In recent years, several new interesting phenomena have been discovered when studying the interaction of sulfur with bimetallic surfaces using the modern techniques of surface science. Very small amounts of sulfur are able to induce dramatic changes in the morphology of bimetallic surfaces that combine noble metals (Cu, Ag, An) and transition metals. This phenomenon can lead to big modifications in the activity and selectivity of bimetallic catalysts used for hydrocarbon reforming. In many cases, bimetallic bonding produces a significant redistribution of charge around the bonded metals. The electronic perturbations associated with the formation of a heteronuclear metal-metal bond can affect the reactivity of the bonded metals toward sulfur. This can be a very important issue to consider when trying to minimize the negative effects of sulfur poisoning (Sn/Pt versus Ag/Pt and Cu/Pt catalysts) or when trying to improve the performance of desulfurization catalysts (Co/Mo and Ni/Mo systems). Clearly much more work is necessary in this area, but new concepts are emerging that can be useful for designing more efficient bimetallic catalysts. (C) 2006 Elsevier Ltd. All rights reserved. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Rodriguez, JA (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM rodrigez@bnl.gov NR 111 TC 58 Z9 60 U1 4 U2 40 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0079-6816 J9 PROG SURF SCI JI Prog. Surf. Sci. PY 2006 VL 81 IS 4 BP 141 EP 189 DI 10.1016/j.progsurf.2006.02.001 PG 49 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 043LO UT WOS:000237602800001 ER PT J AU Jarzynski, C AF Jarzynski, Christopher TI Work fluctuation theorems and single-molecule biophysics SO PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT LA English DT Article; Proceedings Paper CT 20th Nishinomiya-Yukawa Memorial Symposium CY OCT 03-04, 2005 CL Nishinomiya, JAPAN ID FREE-ENERGY DIFFERENCES; ISOTHERMAL-ISOBARIC ENSEMBLE; NONEQUILIBRIUM THERMODYNAMICS; SMALL SYSTEMS; INTRAMOLECULAR STRUCTURES; IRREVERSIBLE-PROCESSES; STATISTICAL-MECHANICS; DISSIPATION RELATIONS; CHEMICAL-EQUILIBRIA; STOCHASTIC DYNAMICS AB Work fluctuation theorems offer a new set of theoretical tools for studying problems of biophysical interest. I will discuss issues related to both the practical application of these tools in the context of single-molecule experiments and simulations, and the interpretation of the quantities appearing in these theorems. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Jarzynski, C (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RI Jarzynski, Christopher/B-4490-2009 OI Jarzynski, Christopher/0000-0002-3464-2920 NR 62 TC 12 Z9 12 U1 1 U2 7 PU PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE PI KYOTO PA C/O KYOTO UNIV, YUKAWA HALL, KYOTO, 606-8502, JAPAN SN 0375-9687 J9 PROG THEOR PHYS SUPP JI Prog. Theor. Phys. Suppl. PY 2006 IS 165 BP 1 EP 17 PG 17 GA 121HZ UT WOS:000243150000003 ER PT B AU Hartzell, P Reed, DW AF Hartzell, Patricia Reed, David W. BE Dworkin, M Falkow, S Rosenberg, E Schleifer, KH Stackebrandt, E TI The Genus Archaeoglobus SO PROKARYOTES: A HANDBOOK ON THE BIOLOGY OF BACTERIA, VOL 3, THIRD EDITION: ARCHAEA. BACTERIA: FIRMICUTES, ACTINOMYCETES LA English DT Article; Book Chapter ID SULFATE-REDUCING ARCHAEBACTERIUM; MONOXIDE DEHYDROGENASE PATHWAY; DISSIMILATORY ATP SULFURYLASE; ACETYL-COA SYNTHETASE; HYPERTHERMOPHILIC ARCHAEON; ADENYLYLSULFATE REDUCTASE; CRYSTAL-STRUCTURE; SP-NOV; F420H2-QUINONE OXIDOREDUCTASE; ISOCITRATE DEHYDROGENASE C1 [Hartzell, Patricia] Univ Idaho, Dept Microbiol Mol Biol & Biochem, Moscow, ID 83844 USA. [Reed, David W.] Idaho Natl Lab, Dept Biotechnol, Idaho Falls, ID 83415 USA. RP Hartzell, P (reprint author), Univ Idaho, Dept Microbiol Mol Biol & Biochem, Moscow, ID 83844 USA. OI Reed, David/0000-0003-4877-776X NR 87 TC 13 Z9 14 U1 1 U2 4 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES BN 978-0-387-25493-7 PY 2006 BP 82 EP 100 DI 10.1007/0-387-30743-5_6 D2 10.1007/0-387-30743-5 PG 19 WC Microbiology SC Microbiology GA BKJ67 UT WOS:000268326100006 ER PT B AU Francino, MP Santos, SR Ochman, H AF Francino, M. Pilar Santos, Scott R. Ochman, Howard BE Dworkin, M Falkow, S Rosenberg, E Schleifer, KH Stackebrandt, E TI Phylogenetic Relationships of Bacteria with Special Reference to Endosymbionts and Enteric Species SO PROKARYOTES: A HANDBOOK ON THE BIOLOGY OF BACTERIA, VOL 6, THIRD EDITION: PROTEOBACTERIA: GAMMA SUBCLASS LA English DT Article; Book Chapter ID HORIZONTAL GENE-TRANSFER; COMPARATIVE SEQUENCE-ANALYSIS; ELONGATION-FACTOR TU; EVOLUTIONARY RELATIONSHIPS; ESCHERICHIA-COLI; UNIVERSAL TREE; SIGNATURE SEQUENCES; GENOME TREES; ACHROMOBACTER NEMATOPHILUS; CHLOROFLEXUS-AURANTIACUS C1 [Francino, M. Pilar] US DOE, Joint Genome Inst, Evolutionary Genom Dept, Walnut Creek, CA 94598 USA. [Santos, Scott R.; Ochman, Howard] Univ Arizona, Dept Biochem & Mol Biophys, Tucson, AZ 85721 USA. RP Santos, SR (reprint author), US DOE, Joint Genome Inst, Evolutionary Genom Dept, Walnut Creek, CA 94598 USA. NR 137 TC 3 Z9 3 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES BN 978-0-387-25496-8 PY 2006 BP 41 EP 59 DI 10.1007/0-387-30746-x_2 D2 10.1007/0-387-30746-X PG 19 WC Microbiology SC Microbiology GA BKK09 UT WOS:000268343700002 ER PT J AU Qiu, Y Tereshko, V Kim, Y Zhang, RG Collart, F Yousef, M Kossiakoff, A Joachimiak, A AF Qiu, Y Tereshko, V Kim, Y Zhang, RG Collart, F Yousef, M Kossiakoff, A Joachimiak, A TI The crystal structure of Aq_328 from the hyperthermophilic bacteria Aquifex aeolicus shows an ancestral histone fold SO PROTEINS-STRUCTURE FUNCTION AND BIOINFORMATICS LA English DT Article DE structural genomics; MAD phasing; synchrotron radiation; histone fold; thermostability ID ARCHAEON METHANOTHERMUS-FERVIDUS; HYPOTHETICAL PROTEIN; HIGH-THROUGHPUT; CORE; NUCLEOSOMES; REFINEMENT; RESOLUTION; GENOMICS; OCTAMER; BINDING AB The structure of Aq_328, an uncharacterized protein from hyperthermophilic bacteria Aquifex aeolicus, has been determined to 1.9 angstrom by using multi-wavelength anomalous diffraction (MAD) phasing. Although the amino acid sequence analysis shows that Aq_328 has no significant similarity to proteins with a known structure and function, the structure comparison by using the Dali server reveals that it: (1) assumes a histone-like fold, and (2) is similar to an ancestral nuclear histone protein (PDB code 1F1E) with z-score 8.1 and RMSD 3.6 angstrom over 124 residues. A sedimentation equilibrium experiment indicates that Aq_328 is a monomer in solution, with an average sedimentation coefficient of 2.4 and an apparent molecular weight of about 20 kDa. The overall architecture of Aq_328 consists of two noncanonical histone domains in tandem repeat within a single chain, and is similar to eukaryotic heterodimer (H2A/H2B and H3/H4) and an archaeal histone heterodimer (HMfA/HMfB). The sequence comparisons between the two histone domains of Aq_328 and six eukaryotic/archaeal his-tones demonstrate that most of the conserved residues that underlie the Aq_328 architecture are used to build and stabilize the two cross-shaped antiparallel histone domains. The high percentage of salt bridges in the structure could be a factor in the protein's thermostability. The structural similarities to other histone-like proteins, molecular properties, and potential function of Aq_328 are discussed in this paper. C1 Argonne Natl Lab, Biosci Div, Struct Biol Ctr, Argonne, IL 60439 USA. Univ Chicago, Dept Biochem & Mol Biol, Chicago, IL 60637 USA. Argonne Natl Lab, Biosci Div, Midw Ctr Struct Genom, Argonne, IL 60439 USA. RP Joachimiak, A (reprint author), Argonne Natl Lab, Biosci Div, Struct Biol Ctr, 9700 S Cass Ave,Bldg 202, Argonne, IL 60439 USA. EM koss@cummings.uchicago.edu; andrzejj@anl.gov OI Collart, Frank/0000-0001-6942-4483 FU NIGMS NIH HHS [P50 GM062414-02, GM62414, P50 GM062414] NR 38 TC 7 Z9 7 U1 0 U2 2 PU WILEY-LISS PI HOBOKEN PA DIV JOHN WILEY & SONS INC, 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0887-3585 J9 PROTEINS JI Proteins PD JAN 1 PY 2006 VL 62 IS 1 BP 8 EP 16 DI 10.1002/prot.20590 PG 9 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 000CN UT WOS:000234438600003 PM 16287087 ER PT J AU Bielnicki, J Devedjiev, Y Derewenda, U Dauter, Z Joachimiak, A Derewenda, ZS AF Bielnicki, J Devedjiev, Y Derewenda, U Dauter, Z Joachimiak, A Derewenda, ZS TI B-subtilis ykuD protein at 2.0 A resolution: Insights into the structure and function of a novel, ubiquitous family of bacterial enzymes SO PROTEINS-STRUCTURE FUNCTION AND BIOINFORMATICS LA English DT Article DE hydrolase; crystal structure; catalytic triad; structural genomics; protein crystallization ID STAPHYLOCOCCUS-AUREUS; CELL-WALL; CRYSTAL-STRUCTURE; BINDING-PROTEINS; SURFACE PROTEIN; LYSM DOMAIN; SORTASE-B; CATALYSIS; MODEL; SITE AB The crystal structure of the product of the Bacillus subtilis ykuD gene was solved by the multiwavelength anomalous dispersion (MAD) method and refined using data to 2.0 angstrom resolution. The ykuD protein is a representative of a distinctly prokaryotic and ubiquitous family found among both pathogenic and nonpathogenic Gram-positive and Gram-negative bacteria. The deduced amino acid sequence reveals the presence of an N-terminal LysM domain, which occurs among enzymes involved in cell wall metabolism, and a novel, putative catalytic domain with a highly conserved His/Cys-containing motif of hitherto unknown structure. As the wild-type protein did not crystallize, a double mutant was designed (Lys117A1a/Gln118Ala) to reduce excess surface conformational entropy. As expected, the structure of the LysM domain is similar to the NMR structure reported for an analogous domain from Escherichia coli murein transglycosylase MUD. The molecular model also shows that the 112-residue-long C-terminal domain has a novel tertiary fold consisting of a beta-sandwich with two mixed sheets, one containing five strands and the other, six strands. The two beta-sheets form a cradle capped by an a-helix. This domain contains a putative catalytic site with a tetrad of invariant His123, Gly124, Cys139, and Arg141. The stereochemistry of this active site shows similarities to peptidotransferases and sortases, and suggests that the enzymes of the ykuD family may play an important role in cell wall biology. C1 Univ Virginia, Dept Mol Physiol & Biol Phys, Charlottesville, VA 22908 USA. NCI, Synchrotron Radiat Res Sect, Argonne Natl Lab, Argonne, IL USA. Argonne Natl Lab, Biosci Div, Argonne, IL 60439 USA. Argonne Natl Lab, Struct Biol Ctr, Argonne, IL 60439 USA. RP Derewenda, ZS (reprint author), Univ Virginia, Dept Mol Physiol & Biol Phys, POB 00736, Charlottesville, VA 22908 USA. EM zsd4n@virginia.edu FU NIGMS NIH HHS [P50 GM062414-02, GM62615, P-50-GM62414, P50 GM062414, R01 GM062615] NR 33 TC 53 Z9 56 U1 1 U2 6 PU WILEY-LISS PI HOBOKEN PA DIV JOHN WILEY & SONS INC, 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0887-3585 J9 PROTEINS JI Proteins PD JAN 1 PY 2006 VL 62 IS 1 BP 144 EP 151 DI 10.1002/prot.20702 PG 8 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 000CN UT WOS:000234438600014 PM 16287140 ER PT J AU Lu, WC Wang, CZ Yu, EW Ho, KM AF Lu, WC Wang, CZ Yu, EW Ho, KM TI Dynamics of the trimeric AcrB transporter protein inferred from a B-Factor analysis of the crystal structure SO PROTEINS-STRUCTURE FUNCTION AND BIOINFORMATICS LA English DT Article DE multidrug transporter; efflux pump; B-factors; anisotropic network model (ANM); normal mode analysis; membrane protein ID MULTIDRUG EFFLUX PUMP; ELASTIC NETWORK MODEL; MOLECULAR-DYNAMICS; ESCHERICHIA-COLI; FLUCTUATIONS; REFINEMENT; ANISOTROPY; INHIBITOR; MOTIONS AB The Escherichia coli AcrB multidrug transporter recognizes a wide range of toxic chemicals and actively extrudes them from cells. The molecular basis of multidrug transport in AcrB remains unknown. Herein, we describe normal mode analyses to study important regions for drug recognition and extrusion in this transporter. Based on the X-ray structure of AcrB, an elastic network model has been able to correct errors arising from crystal imperfection in the experimental B-factors. The results allow us to understand the functional dynamics of this membrane protein. It is expected that this technique can be applied to other membrane proteins with known structures. C1 Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Jilin Univ, State Key Lab Theoret & Computat Chem, Changchun 130023, Peoples R China. RP Ho, KM (reprint author), Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. EM kmh@ameslab.gov FU NIGMS NIH HHS [R01 GM074027, R01 GM074027-02] NR 22 TC 16 Z9 16 U1 0 U2 5 PU WILEY-LISS PI HOBOKEN PA DIV JOHN WILEY & SONS INC, 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0887-3585 J9 PROTEINS JI Proteins PD JAN 1 PY 2006 VL 62 IS 1 BP 152 EP 158 DI 10.1002/prot.20743 PG 7 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 000CN UT WOS:000234438600015 PM 16288462 ER PT J AU Liu, GH Shen, Y Xiao, R Acton, T Ma, LC Joachimiak, A Montelione, GT Szyperski, T AF Liu, GH Shen, Y Xiao, R Acton, T Ma, LC Joachimiak, A Montelione, GT Szyperski, T TI NMR structure of protein yqbG from Bacillus subtilis reveals a novel alpha-helical protein fold SO PROTEINS-STRUCTURE FUNCTION AND BIOINFORMATICS LA English DT Article ID ESCHERICHIA-COLI; DATABASE; INFORMATION; QUALITY; ASSIGNMENT; PROGRAMS C1 SUNY Buffalo, Dept Chem, Buffalo, NY 14260 USA. Rutgers State Univ, Ctr Adv Biotechnol & Med, Piscataway, NJ USA. Rutgers State Univ, Dept Mol Biol & Biochem, Piscataway, NJ USA. Struct Biol Ctr, Argonne Natl Lab, Argonne, IL USA. RP Szyperski, T (reprint author), SUNY Buffalo, Dept Chem, Buffalo, NY 14260 USA. EM szypersk@chem.buffalo.edu RI Shen, Yang/C-3064-2008 OI Shen, Yang/0000-0003-1408-8034 FU NIGMS NIH HHS [P50 GM62413-01] NR 20 TC 1 Z9 2 U1 0 U2 1 PU WILEY-LISS PI HOBOKEN PA DIV JOHN WILEY & SONS INC, 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0887-3585 J9 PROTEINS JI Proteins PD JAN 1 PY 2006 VL 62 IS 1 BP 288 EP 291 DI 10.1002/prot.20666 PG 4 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 000CN UT WOS:000234438600028 PM 16281282 ER PT J AU Schmitt, S Prokisch, H Schlunck, T Camp, DG Ahting, U Waizenegger, T Scharfe, C Meitinger, T Imhof, A Neupert, W Oefner, PJ Rapaport, D AF Schmitt, S Prokisch, H Schlunck, T Camp, DG Ahting, U Waizenegger, T Scharfe, C Meitinger, T Imhof, A Neupert, W Oefner, PJ Rapaport, D TI Proteome analysis of mitochondrial outer membrane from Neurospora crassa SO PROTEOMICS LA English DT Article DE Mim1; mitochondria; outer membrane; proteome ID YEAST SACCHAROMYCES-CEREVISIAE; MASS-SPECTROMETRY; GENOME SEQUENCE; TOM COMPLEX; LOCALIZATION; TRANSLOCATION; EXPRESSION; COMPONENT; PROTEINS; IMPORT AB The mitochondrial outer membrane mediates numerous interactions between the metabolic and genetic systems of mitochondria and the rest of the eukaryotic cell. We performed a proteomic study to discover novel functions of components of the mitochondrial outer membrane. Proteins of highly pure outer membrane vesicles (OMV) from Neurospora crassa were identified by a combination of LC-MS/MS of tryptic peptide digests and gel electrophoresis of solubilized OMV proteins, followed by their identification using MALDI-MS PMF. Among the 30 proteins found in at least three of four separate analyses were 23 proteins with known functions in the outer membrane. These included components of the import machinery (the TOM and TOB complexes), a pore-forming component (porin), and proteins that control fusion and fission of the organelle. in addition, proteins playing a role in various biosynthetic pathways, whose intracellular location had not been established previously, could be localized to the mitochondrial outer membrane. Thus, the proteome of the outer membrane can help in identifying new mitochondria-related functions. C1 Univ Munich, Inst Physiol Chem, D-81377 Munich, Germany. GSF, Natl Res Ctr, Inst Human Genet, Neuherberg, Germany. Tech Univ Munich, Inst Human Genet, D-8000 Munich, Germany. Univ Munich, Adolf Butenandt Inst, Prot Anal Unit, Munich, Germany. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Stanford Genome Technol Ctr, Palo Alto, CA USA. RP Rapaport, D (reprint author), Univ Munich, Inst Physiol Chem, Butenandtstr 5, D-81377 Munich, Germany. EM rapaport@med.uni-muenchen.de RI Prokisch, Holger/N-8964-2013; Meitinger, Thomas/O-1318-2015; Oefner, Peter/K-1116-2016 OI Oefner, Peter/0000-0002-1499-3977 FU NIGMS NIH HHS [GM 63883] NR 29 TC 49 Z9 57 U1 0 U2 5 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 1615-9853 J9 PROTEOMICS JI Proteomics PD JAN PY 2006 VL 6 IS 1 BP 72 EP 80 DI 10.1002/pmic.200402084 PG 9 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 004PN UT WOS:000234764800009 PM 16294304 ER PT J AU Khare, T Esteve-Nunez, A Nevin, KP Zhu, WH Yates, JR Lovley, D Giometti, CS AF Khare, T Esteve-Nunez, A Nevin, KP Zhu, WH Yates, JR Lovley, D Giometti, CS TI Differential protein expression in the metal-reducing bacterium Geobacter sulfurreducens strain PCA grown with fumarate or ferric citrate SO PROTEOMICS LA English DT Article DE 2-DE; Geobacter; metal-reducing bacteria; superoxide dismutase ID URANIUM-CONTAMINATED AQUIFER; 2-DIMENSIONAL ELECTROPHORESIS; GEL-ELECTROPHORESIS; SHEWANELLA-ONEIDENSIS; OXIDATIVE STRESS; TISSUE PROTEINS; CELL FRACTIONS; REDUCTION; QUANTITATION; RESPIRATION AB Geobacter sulfurreducens, generally considered to be a strict anaerobe, is a predominant microbe in subsurface environments, where it utilizes available metals as electron acceptors. To better understand the metabolic processes involved in the metal-reduction capability of this microbe, the proteins expressed by cells grown anaerobically with either fumarate or ferric citrate as electron acceptor were compared. Proteins were separated by 2-DE under denaturing or nondenaturing conditions, and proteins varying in abundance with a high level of statistical significance (p < 0.0001) were identified by peptide mass analysis. Denaturing 2-DE revealed significant differences in the relative abundance of the membrane proteins OmpA and peptidoglycan-associated lipoprotein, several metabolic enzymes, and, in addition, superoxide dismutase and rubredoxin oxidoreductase. Nondenaturing 2-DE revealed elevated catalase in cells grown with ferric citrate. These results suggest that, in addition to adjustments in membrane transport and specific metabolic pathways in response to these two different electron acceptors, distinct differences exist in the oxidative environment within the cell when fumarate or soluble ferric citrate is provided as electron acceptor. Although an anaerobe, G. sulfurreducens appears to have alternate mechanisms for dealing with reactive oxygen species in response to increased intracellular soluble iron. C1 Argonne Natl Lab, Biosci Div, Argonne, IL 60439 USA. Univ Massachusetts, Amherst, MA 01003 USA. Scripps Res Inst, La Jolla, CA USA. RP Giometti, CS (reprint author), Argonne Natl Lab, Biosci Div, 9700 S Cass Ave, Argonne, IL 60439 USA. EM csgiometti@anl.gov NR 30 TC 16 Z9 19 U1 4 U2 19 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1615-9853 J9 PROTEOMICS JI Proteomics PD JAN PY 2006 VL 6 IS 2 BP 632 EP 640 DI 10.1002/pmic.200500137 PG 9 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 010PX UT WOS:000235207700026 PM 16342140 ER PT S AU Talbott, TD Schuchardt, KL Stephan, EG Myers, JD AF Talbott, Tara D. Schuchardt, Karen L. Stephan, Eric G. Myers, James D. BE Moreau, L Foster, I TI Mapping physical formats to logical models to extract data and metadata: The Defuddle parsing engine SO PROVENANCE AND ANNOTATION OF DATA SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT International Provenance and Annotation Workshop (IPAW 2006) CY MAY 03-05, 2006 CL Univ Chicago, Chicago, IL SP Springer, Microsoft, Global Grid Forum, Argonne Natl Lab, Univ Southhampton HO Univ Chicago AB Scientists, motivated by the desire for systems-level understanding of phenomena, increasingly need to share their results across multiple disciplines. Accomplishing this requires data to be annotated, contextualized, and readily searchable and translated into other formats. While these requirements can be addressed by custom programming or obviated by community standardization, neither approach has 'solved' the problem. In this paper, we describe a complementary approach - a general capability for articulating the format of arbitrary textual and binary data using a logical data model, expressed in XML-Schema, which can be used to provide annotation and context, extract metadata, and enable translation. This work is based on the draft specification for the Data Format Description Language and our open source "Defuddle" parser. We present an overview of the specification, detail the design of Defuddle, and discuss the benefits and challenges of this general approach to enabling discovery, sharing, and interpretation of diverse data sets. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Natl Ctr Supercomp Applicat, Urbana, IL 61801 USA. RP Talbott, TD (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. EM Tara.Talbott@pnl.gov; Karen.Schuchardt@pnl.gov; Eric.Stephan@pnl.gov; jimmyers@ncsa.uiuc.edu OI Stephan, Eric/0000-0002-8155-6806; Myers, James/0000-0001-8462-650X NR 6 TC 2 Z9 2 U1 0 U2 1 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-46302-X J9 LECT NOTES COMPUT SC PY 2006 VL 4145 BP 73 EP 81 PG 9 WC Computer Science, Information Systems; Computer Science, Theory & Methods SC Computer Science GA BFE42 UT WOS:000241462000009 ER PT S AU Zhao, Y Wilde, M Foster, I AF Zhao, Yong Wilde, Michael Foster, Ian BE Moreau, L Foster, I TI Applying the virtual data provenance model SO PROVENANCE AND ANNOTATION OF DATA SE Lecture Notes in Computer Science LA English DT Article; Proceedings Paper CT International Provenance and Annotation Workshop (IPAW 2006) CY MAY 03-05, 2006 CL Univ Chicago, Chicago, IL SP Springer, Microsoft, Global Grid Forum, Argonne Natl Lab, Univ Southhampton HO Univ Chicago ID AUTOMATED IMAGE REGISTRATION; VALIDATION AB In many domains of science, engineering, and commerce, data analysis systems are employed to derive new data (and ultimately, one hopes, knowledge) from datasets describing experimental results or simulated phenomena. To support such analyses, we have developed a "virtual data system" that allows users first to define, then to invoke, and finally explore the provenance of procedures (and workflows comprising multiple procedure calls) that perform such data derivations. The underlying execution model is "functional" in the sense that procedures read (but do not modify) their input and produce output via deterministic computations. This property makes it straightforward for the virtual data system to record not only the recipe for producing any given data object but also sufficient information about the environment in which the recipe has been executed, all with sufficient fidelity that the steps used to create a data object can be re-executed to reproduce the data object at a later time or a different location. The virtual data system maintains this information in an integrated schema alongside semantic annotations, and thus enables a powerful query capability in which the rich semantic information implied by knowledge of the structure of data derivation procedures can be exploited to provide an information environment that fuses recipe, history, and application-specific semantics. We provide here an overview of this integration, the queries and transformations that it enables, and examples of how these capabilities can serve scientific processes. C1 Univ Chicago, Chicago, IL 60637 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Zhao, Y (reprint author), Univ Chicago, Chicago, IL 60637 USA. EM yongzh@cs.uchicago.edu RI Muniswamy-Reddy, Kiran-Kumar/A-4539-2012 NR 30 TC 14 Z9 16 U1 2 U2 3 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-46302-X J9 LECT NOTES COMPUT SC PY 2006 VL 4145 BP 148 EP 161 PG 14 WC Computer Science, Information Systems; Computer Science, Theory & Methods SC Computer Science GA BFE42 UT WOS:000241462000016 ER PT S AU Chevassut, O Fouque, PA Gaudry, P Pointcheval, D AF Chevassut, Olivier Fouque, Pierre-Alain Gaudry, Pierrick Pointcheval, David BE Yung, M Dodis, Y Kiayias, A Malkin, T TI The Twist-AUgmented technique for key exchange SO PUBLIC KEY CRYPTOGRAPHY - PKC 2006, PROCEEDINGS SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 9th International Conference on Theory and Practice of Public Key Cryptography CY APR 24-26, 2006 CL New York, NY SP EADS, Morgan Stanley, Gemplus, NTT DoCoMo, Google, Microsoft, RSA Secur ID HELLMAN; SECURE AB Key derivation refers to the process by which an agreed upon large random number, often named master secret, is used to derive keys to encrypt and authenticate data. Practitioners and standardization bodies have usually used the random oracle model to get key material from a Diffie-Hellman key exchange. However, formal proofs in the standard model require randomness extractors to formally extract the entropy of the random master secret into a seed prior to deriving other keys. Whereas this is a quite simple tool, it is not easy to use in practice -or it is easy to misuse it-. In addition, in many standards, the acronym PRF (Pseudo-Random Functions) is used for several tasks, and namely the randomness extraction. While randomness extractors and pseudo-random functions are a priori distinct tools, we first study whether such an application is correct or not. We thereafter study the case of Z(p)(*) where p is a safe-prime and the case of elliptic curve since in IPSec for example, only these two groups are considered. We present very efficient and provable randomness extraction techniques for these groups under the DDH assumption. In the special case of elliptic curves, we present a new technique -the so-called 'Twist-AUgmented' technique which exploits specific properties of some elliptic curves, and avoids the need of any randomness extractor. We finally compare the efficiency of this method with other solutions. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Ecole Normale Super, CNRS, Paris, France. CNRS, LORIA, Nancy, France. RP Chevassut, O (reprint author), Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM OChevassut@lbl.gov; Pierre-Alain.Fouque@ens.fr; Pierrick.Gaudry@loria.fr; David.Pointcheval@ens.fr NR 34 TC 23 Z9 23 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-33851-9 J9 LECT NOTES COMPUT SC PY 2006 VL 3958 BP 410 EP 426 PG 17 WC Computer Science, Theory & Methods SC Computer Science GA BEM71 UT WOS:000238186800027 ER PT S AU Abdalla, M Bresson, E Chevassut, O Pointcheval, D AF Abdalla, Michel Bresson, Emmanuel Chevassut, Olivier Pointcheval, David BE Yung, M Dodis, Y Kiayias, A Malkin, T TI Password-based group key exchange in a constant number of rounds SO PUBLIC KEY CRYPTOGRAPHY - PKC 2006, PROCEEDINGS SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 9th International Conference on Theory and Practice of Public Key Cryptography CY APR 24-26, 2006 CL New York, NY SP EADS, Morgan Stanley, Gemplus, NTT DoCoMo, Google, Microsoft, RSA Secur DE password-based authentication; group key exchange ID SECURE; PROTOCOLS AB With the development of grids, distributed applications are spread across multiple computing resources and require efficient security mechanisms among the processes. Although protocols for authenticated group Diffie-Hellman key exchange protocols seem to be the natural mechanisms for supporting these applications, current solutions are either limited by the use of public key infrastructures or by their scalability, requiring a number of rounds linear in the number of group members. To overcome these shortcomings, we propose in this paper the first provably-secure password-based constant-round group key exchange protocol. It is based on the protocol of Burmester and Desmedt and is provably-secure in the random-oracle and ideal-cipher models, under the Decisional Diffie-Hellman assumption. The new protocol is very efficient and fully scalable since it only requires four rounds of communication and four multi-exponentiations per user. Moreover, the new protocol avoids intricate authentication infrastructures by relying on passwords for authentication. C1 Ecole Normale Super, Dept Informat, F-75230 Paris 05, France. CELAR, Cryptol Dept, F-35174 Bruz, France. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Abdalla, M (reprint author), Ecole Normale Super, Dept Informat, 45 Rue Ulm, F-75230 Paris 05, France. EM Michel.Abdalla@ens.fr; Emmanuel.Bresson@polytechnique.org; OChevassut@lbl.gov; David.Pointcheval@ens.fr RI Abdalla, Michel/H-5987-2016 OI Abdalla, Michel/0000-0002-2447-4329 NR 17 TC 49 Z9 54 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-33851-9 J9 LECT NOTES COMPUT SC PY 2006 VL 3958 BP 427 EP 442 PG 16 WC Computer Science, Theory & Methods SC Computer Science GA BEM71 UT WOS:000238186800028 ER PT J AU Rodgers, A Tkalcic, H McCallen, D Larsen, S Snelson, C AF Rodgers, A Tkalcic, H McCallen, D Larsen, S Snelson, C TI Site response in Las Vegas Valley, Nevada from NTS explosions and earthquake data SO PURE AND APPLIED GEOPHYSICS LA English DT Article DE site response; strong ground motion; basin response ID SAN-FRANCISCO-BAY; STRONG-MOTION; AMPLIFICATION; CALIFORNIA; WAVE; MICROZONATION; INVERSION; STATION; RANGE; PHASE AB We report site response in Las Vegas Valley (LVV) from historical recordings of Nevada Test Site (NTS) nuclear explosions and earthquake recordings from permanent and temporary seismic stations. Our data set significantly improves the spatial coverage of LVV over previous studies, especially in the northern, deeper parts of the basin. Site response at stations in LVV was measured for frequencies in the range 0.2-5.0 Hz using Standard Spectral Ratios (SSR) and Horizontal-Vertical Spectral Ratios (HVR). For the SSR measurements we used a reference site (approximately NEHRP B ``rock'' classification) located on Frenchman Mountain outside the basin. Site response at sedimentary sites is variable in LVV with average amplifications approaching a factor of 10 at some frequencies. We observed peaks in the site response curves at frequencies clustered near 0.6, 1.2 and 2.0 Hz, with some sites showing additional lower amplitude peaks at higher frequencies. The spatial pattern of site response is strongly correlated with the reported depth to basement for frequencies between 0.2 and 3.0 Hz, although the frequency of peak amplification does not show a similar correlation. For a few sites where we have geotechnical shear velocities, the amplification shows a correlation with the average upper 30-meter shear velocities, V-30. We performed two-dimensional finite difference simulations and reproduced the observed peak site amplifications at 0.6 and 1.2 Hz with a low velocity near-surface layer with shear velocities 600-750 m/s and a thickness of 100-200 m. These modeling results indicate that the amplitude and frequencies of site response peaks in LVV are strongly controlled by shallow velocity structure. C1 Lawrence Livermore Natl Lab, Atmospher Earth Environm Sci Dept, Energy Environm Directorate, Livermore, CA 94551 USA. Lawrence Livermore Natl Lab, Yucca Mt Repository Sci Program, Energy Environm Directorate, Livermore, CA 94551 USA. Lawrence Livermore Natl Lab, Comp Applicat & Res Dept, Computat Directorate, Livermore, CA 94551 USA. Univ Nevada, Dept Geosci, Las Vegas, NV 89154 USA. RP Rodgers, A (reprint author), Lawrence Livermore Natl Lab, Atmospher Earth Environm Sci Dept, Energy Environm Directorate, Livermore, CA 94551 USA. EM rodgers7@llnl.gov RI Rodgers, Arthur/E-2443-2011; Tkalcic, Hrvoje/E-8465-2013 OI Tkalcic, Hrvoje/0000-0001-7072-490X NR 51 TC 10 Z9 10 U1 0 U2 2 PU BIRKHAUSER VERLAG AG PI BASEL PA VIADUKSTRASSE 40-44, PO BOX 133, CH-4010 BASEL, SWITZERLAND SN 0033-4553 J9 PURE APPL GEOPHYS JI Pure Appl. Geophys. PD JAN PY 2006 VL 163 IS 1 BP 55 EP 80 DI 10.1007/s00024-005-0010-1 PG 26 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 006OW UT WOS:000234907800004 ER PT B AU McQueen, MA Boyer, WF Flynn, MA Beitel, GA AF McQueen, Miles A. Boyer, Wayne F. Flynn, Mark A. Beitel, George A. BE Gollmann, D Massacci, F Yautsiukhin, A TI Time-to-compromise model for cyber risk reduction estimation SO QUALITY OF PROTECTION: SECURITY MEASUREMENTS AND METRICS SE Advances in Information Security LA English DT Proceedings Paper CT 1st Workshop on Quality of Protection CY 2005 CL Milan, ITALY AB We propose a new model for estimating the time to compromise a system component that is visible to an attacker. The model provides an estimate of the expected value of the time-to-compromise as a function of known and visible vulnerabilities, and attacker skill level. The time-to-compromise random process model is a composite of three subprocesses associated with attacker actions aimed at the exploitation of vulnerabilities. In a case study, the model was used to aid in a risk reduction estimate between a baseline Supervisory Control and Data Acquisition (SCADA) system and the baseline system enhanced through a specific set of control system security remedial actions. For our case study, the total number of system vulnerabilities was reduced by 86% but the dominant attack path was through a component where the number of vulnerabilities was reduced by only 42% and the time-to-compromise of that component was increased by only 13% to 30% depending on attacker skill level. C1 [McQueen, Miles A.; Boyer, Wayne F.; Flynn, Mark A.; Beitel, George A.] Idaho Natl Lab, 2525 N Fremont, Idaho Falls, ID 83415 USA. RP McQueen, MA (reprint author), Idaho Natl Lab, 2525 N Fremont, Idaho Falls, ID 83415 USA. EM miles.mcqueen@inl.gov; wayne.boyer@inl.gov; mark.flynn@inl.gov; george.beitel@inl.gov NR 15 TC 11 Z9 11 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES BN 0-387-29016-8 J9 ADV INFORM SECUR PY 2006 BP 49 EP + PG 3 WC Computer Science, Artificial Intelligence; Computer Science, Software Engineering SC Computer Science GA BFJ41 UT WOS:000242337000005 ER PT S AU Boye, RR Kemme, SA Wendt, JR Cruz-Cabrera, AA Vawter, GA Alford, CR Carter, TR Samora, S AF Boye, R. R. Kemme, S. A. Wendt, J. R. Cruz-Cabrera, A. A. Vawter, G. A. Alford, C. R. Carter, T. R. Samora, S. BE Razeghi, M Brown, GJ TI Pixilated wideband achromatic waveplates fabricated for the mid IR using subwavelength features - art. no. 612709 SO Quantum Sensing and Nanophotonic Devices III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Quantum Sensing and Nanophotonic Devices III CY JAN 23-26, 2006 CL San Jose, CA DE subwavelength grating; form birefringence; polarization; infrared; microstructure devices; quarter-wave plate ID COMPLETE STOKES POLARIMETER; COUPLED-WAVE ANALYSIS; BINARY GRATINGS; IMPLEMENTATION; OPTIMIZATION; REGION AB Subwavelength diffractive features etched into a substrate lead to form birefringence that can be utilized to produce polarization sensitive elements such as waveplates. Using etched features allows for the development of pixilated devices to be used in conjunction with focal plane arrays in polarimetric imaging systems. Typically, the main drawback from using diffractive devices is their high sensitivity to wavelength. Taking advantage of the dispersion of the form birefringence, diffractive waveplates with good achromatic characteristics can be designed. We will report on diffractive waveplates designed for minimal phase retardation error across the 2-5 micron spectral regime. The required fabrication processes of the sub-wavelength feature sizes will be discussed as well as the achromatic performance and transmission efficiency of final devices. Previous work in this area has produced good results over a subset of this wavelength band, but designing for this extended band is particularly challenging. In addition, the effect of the finite size of the apertures of the pixilated devices is of particular interest since they are designed to be used in conjunction with a detector array. The influence of small aperture sizes will also be investigated. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Boye, RR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 19 TC 3 Z9 3 U1 1 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 0-8194-6169-5 J9 P SOC PHOTO-OPT INS PY 2006 VL 6127 BP 12709 EP 12709 AR 612709 DI 10.1117/12.646803 PG 10 WC Nanoscience & Nanotechnology; Instruments & Instrumentation; Optics SC Science & Technology - Other Topics; Instruments & Instrumentation; Optics GA BEH60 UT WOS:000237277500006 ER PT S AU Ramadurai, D Li, Y Yamanaka, T Geerpuram, D Sankar, V Vasudev, M Alexson, D Shi, P Dutta, M Stroscio, MA Rajh, T Saponjic, Z Kotov, N Tang, Z Xu, S AF Ramadurai, Dinakar Li, Yang Yamanaka, Takayuki Geerpuram, Dwarakanath Sankar, Viswanath Vasudev, Milana Alexson, Dimitri Shi, Peng Dutta, Mitra Stroscio, Michael A. Rajh, Tijana Saponjic, Zoran Kotov, Nicholas Tang, Zhiyong Xu, Song BE Razeghi, M Brown, GJ TI Colloidal quantum dots as optoelectronic elements SO QUANTUM SENSING AND NANOPHOTONIC DEVICES III SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Quantum Sensing and Nanophotonic Devices III CY JAN 23-26, 2006 CL San Jose, CA DE quantum dots; CdTe; CdSe; nanowires; biomolecules; FRET; colloidal nanoparticles; polaron transport in DNA; chemically-directed assembly ID SEMICONDUCTOR NANOCRYSTALS; CHARGE-TRANSFER; DNA; NANOPARTICLES; DISTORTIONS; TRANSPORT AB A variety of colloidal semiconductor quantum dots and related quantum-wire structures are characterized using absorption and photoluminescence measurements. The electronic properties of these structures are modeled and compared with experiment. The characterization and application of ensembles of colloidal quantum dots with molecular interconnects are considered. The chemically-directed assembly of ensembles of colloidal quantum dots with biomolecular interconnects is demonstrated with quantum dot densities in excess of 10(+17) cm(-3). Non-charge transfer processes for switching based on dipole-dipole interactions - Forester interactions - are examined for colloidal quantum dots linked with biomolecules. Charge transport in biomolecules is studied using indirect-bandgap colloidal nanocrystals linked with biomolecules. C1 [Li, Yang; Yamanaka, Takayuki; Sankar, Viswanath; Alexson, Dimitri; Dutta, Mitra; Stroscio, Michael A.] Univ Illinois, Dept Elect & Comp Engn, 851 S Morgan St, Chicago, IL 60607 USA. [Dutta, Mitra; Stroscio, Michael A.] Univ Illinois, Dept Phys, Chicago, IL 60607 USA. [Ramadurai, Dinakar; Geerpuram, Dwarakanath; Vasudev, Milana; Shi, Peng; Stroscio, Michael A.] Univ Illinois, Dept Bioengn, Chicago, IL 60607 USA. [Rajh, Tijana; Saponjic, Zoran] Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. [Kotov, Nicholas; Tang, Zhiyong] Univ Michigan, Dept Chem Engn, Ann Arbor, MI 48109 USA. [Xu, Song] Mol Imaging Inc, Brownstown, MI 48183 USA. RP Ramadurai, D (reprint author), Univ Illinois, Dept Bioengn, Chicago, IL 60607 USA. OI SHI, Peng/0000-0003-0629-4161 FU ARO; AFOSR; DARPA; NSF-SRC; DoE FX The UIC investigators gratefully acknowledge the support of ARO under the direction of Dr. Dwight Woolard, the support of AFOSR under the direction of Dr. Gerald Witt, past support of DARPA under the direction of Dr. John Carrano, and past support of NSF-SRC under the oversight of Drs. Dr. R. Khosla of NSF and Drs. L. Manchanda and Daniel Herr of the SRC. University of Michigan researchers gratefully acknowledge the support of AFOSR and NSF. The investigators working at the Argonne National Laboratory (ANL) gratefully acknowledge the support of the DoE and the resources of the ANL Center for Nanoscale Materials User Facility. The insights of Prof. S. Datta and the use of his algorithms from the Purdue Nanohub are gratefully acknowledged. NR 34 TC 0 Z9 0 U1 0 U2 4 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-6169-5 J9 PROC SPIE PY 2006 VL 6127 AR UNSP 61270L DI 10.1117/12.641067 PG 13 WC Nanoscience & Nanotechnology; Instruments & Instrumentation; Optics SC Science & Technology - Other Topics; Instruments & Instrumentation; Optics GA BEH60 UT WOS:000237277500014 ER PT J AU Pluhar, CJ Bjornstad, BN Reidel, SP Coe, RS Nelson, PB AF Pluhar, CJ Bjornstad, BN Reidel, SP Coe, RS Nelson, PB TI Magnetostratigraphic evidence from the Cold Creek bar for onset of ice-age cataclysmic floods in eastern Washington during the Early Pleistocene SO QUATERNARY RESEARCH LA English DT Article DE paleomagnetism; magnetostratigraphy; susceptibility; hysteresis parameters; Hanford; Pasco Basin; Cold Creek bar; Missoula; scabland; cataclysmic flood; Jokulhlaup ID GLACIAL LAKE MISSOULA; CHANNELED SCABLAND; NORTHEASTERN WASHINGTON; PALEOMAGNETIC DATA; PRE-WISCONSIN; RIVER VALLEY; COLUMBIA; MAGNITUDES; DEPENDENCE; DURATION AB This study provides a detailed magnetostratigraphy of sediments composing the Cold Creek cataclysmic flood bar in the Pasco Basin, Washington. Our interpretation suggests onset of Missoula floods or similar events prior to 1.1 myr, later than previously suggested by Bjornstad et al. [Bjornstad, B.N., Fecht, K.R., Pluhar, C.J., 2001. Long history of pre-Wisconsin, Ice Age cataclysmic floods: evidence from southeastern Washington State. Journal of Geology 109 (6), 695-713]. Nonetheless these data suggest that Channeled Scabland features formed over a much longer timespan than commonly cited, that continental ice sheets of the early Pleistocene reached as far south as those of the late Pleistocene, and that similar physiography existed in eastern Washington and perhaps Montana to both generate and route Missoula-flood-like events. This study adds paleomagnetic polarity results from 213 new samples of silts and sands derived from nine new drill cores penetrating the Cold Creek cataclysmic flood bar to our previous database of 53 samples from four boreholes, resulting in a much more robust and detailed magnetostratigraphy. Rock magnetic studies on these sediments show pure magnetite to be the predominant remanence-carrying magnetic mineral, ruling out widespread remagnetization by secondary mineralization. The magnetostratigraphy at eastern Cold Creek bar is characterized by a normal polarity interval bracketed by reversed polarities. Equating the normal zone with the Jaramillo subchron (0.99-1.07 myr) affords the simplest correlation to the magnetic polarity timescale. Western Cold Creek bar was likely deposited during the Brunhes chron (0-0.78 myr) since it exhibits mainly normal polarities with only two thin reversed-polarity horizons that we interpret as magnetic excursions during the Brunhes. (c) 2005 University of Washington. All rights reserved. C1 Univ Calif Santa Cruz, Dept Earth Sci, Santa Cruz, CA 95064 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Pluhar, CJ (reprint author), Univ Calif Santa Cruz, Dept Earth Sci, 1156 High St, Santa Cruz, CA 95064 USA. EM cpluhar@es.ucsc.edu NR 36 TC 7 Z9 7 U1 0 U2 4 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0033-5894 J9 QUATERNARY RES JI Quat. Res. PD JAN PY 2006 VL 65 IS 1 BP 123 EP 135 DI 10.1016/j.yqres.2005.06.011 PG 13 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 003PF UT WOS:000234693400012 ER PT J AU Davis, PT Briner, JP Coulthard, RD Finkel, RW Miller, GH AF Davis, PT Briner, JP Coulthard, RD Finkel, RW Miller, GH TI Preservation of Arctic landscapes overridden by cold-based ice sheets SO QUATERNARY RESEARCH LA English DT Article DE Baffin Island; glacial erosion; quaternary chronology; cosmogenic nuclide dating; radiocarbon dating ID LAST GLACIAL MAXIMUM; BAFFIN-ISLAND; COSMOGENIC NUCLIDES; PRODUCTION-RATES; SEA-LEVEL; CANADA; LAURENTIDE; NWT; DYNAMICS; SURFACES AB For nearly 40 years, a massive, well-preserved glaciomarine delta more than 54,000 years old and ancillary landforms have formed the cornerstone of models positing limited ice-sheet extent in Arctic Canada during the late Wisconsinan. We present exposure ages for large boulders on the delta surface, which coupled with preservation of relict landforms demonstrate that the region was covered by minimally erosive, cold-based ice during the late Wisconsinan. Our data suggest that surficial features commonly used to define the pattern of late Wisconsinan ice movement cannot be used on their own to constrain late Wisconsinan ice-sheet margins in Arctic regions. (c) 2005 University of Washington. All rights reserved. C1 Bentley Coll, Dept Nat Sci, Waltham, MA 02452 USA. Univ Colorado, Inst Arctic & Alpine Res, Boulder, CO 80303 USA. Univ Colorado, Dept Geol Sci, Boulder, CO 80303 USA. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. RP Davis, PT (reprint author), Bentley Coll, Dept Nat Sci, Waltham, MA 02452 USA. EM pdavis@bentley.edu NR 41 TC 44 Z9 45 U1 0 U2 5 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0033-5894 J9 QUATERNARY RES JI Quat. Res. PD JAN PY 2006 VL 65 IS 1 BP 156 EP 163 DI 10.1016/j.yqres.2005.08.019 PG 8 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 003PF UT WOS:000234693400015 ER PT S AU Sweet, AD Dubbert, DF Doerry, AW Sloan, GR Gutierrez, VD AF Sweet, A. D. Dubbert, D. F. Doerry, A. W. Sloan, G. R. Gutierrez, V. Dee BE Trebits, RN Kurtz, JL TI A portfolio of fine resolution Ku-band miniSAR Images: part I - art. no. 621002 SO Radar Sensor Technology X SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Radar Sensor Technology X CY APR 20-21, 2006 CL Kissimmee, FL SP SPIE DE SAR; miniaturized radar; image; fine resolution AB Sandia-developed SAR systems are well known for their real-time, high quality, high resolution imagery. Recently, a series of tests were completed with the sub-thirty pound, Ku-band miniSAR system. A large data set was collected including real-time images of a variety of target scenes with resolutions as fine as 4 inches. This paper offers a sampling of real-time, high quality, fine resolution images representative of the output of Sandia's miniSAR radar. Images will be annotated with descriptions of collection geometries and other relevant image parameters. The miniSAR system and Sandia DeHaviland DHC-6 Twin Otter test bed are also briefly discussed. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Sweet, AD (reprint author), Sandia Natl Labs, POB 5800,MS 0519, Albuquerque, NM 87185 USA. NR 1 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 0-8194-6266-7 J9 P SOC PHOTO-OPT INS PY 2006 VL 6210 BP 21002 EP 21002 AR 621002 DI 10.1117/12.667613 PG 10 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA BES16 UT WOS:000239242100002 ER PT S AU Shagam, RN Dickey, FM Doerry, AW AF Shagam, Richard N. Dickey, Fred M. Doerry, Armin W. BE Trebits, RN Kurtz, JL TI Geometrical optics analysis of clear-air refractive-index perturbations on SAR images - art. no. 621003 SO Radar Sensor Technology X SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Radar Sensor Technology X CY APR 20-21, 2006 CL Kissimmee, FL SP SPIE DE synthetic aperture radar; SAR; atmospheric effects; geometrical optics ID PHASE ERRORS AB Previous papers have demonstrated that anomalies observed in synthetic aperture radar (SAR) images can be attributed to perturbations in the clear-air refractive index. The atmospheric effect is small, and is more frequent, or apparent, in long range imaging. A geometrical optics (ray-trace) analysis is applied to potential atmospheric perturbations. The results correlate with observations, and demonstrate that the effect is strongly dependent on the azimuth orientation of the atmospheric perturbation. The analysis also demonstrates that the magnitudes of the spatial size of the anomalies and index perturbations can be much smaller than expected. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Shagam, RN (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. NR 8 TC 1 Z9 1 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 0-8194-6266-7 J9 P SOC PHOTO-OPT INS PY 2006 VL 6210 BP 21003 EP 21003 AR 621003 DI 10.1117/12.668326 PG 12 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA BES16 UT WOS:000239242100003 ER PT S AU Sweet, AD Dubbert, DF Doerry, AW Sloan, GR Gutierrez, VD AF Sweet, A. D. Dubbert, D. F. Doerry, A. W. Sloan, G. R. Gutierrez, V. Dee BE Trebits, RN Kurtz, JL TI A portfolio of fine resolution Ku-band miniSAR Images: part II - art. no. 621006 SO Radar Sensor Technology X SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Radar Sensor Technology X CY APR 20-21, 2006 CL Kissimmee, FL SP SPIE DE SAR; miniaturized radar; image; fine resolution AB Sandia-developed SAR systems are well known for their real-time, high quality, high resolution imagery. Recently, a series of tests were completed with the sub-thirty pound, Ku-band miniSAR system. A large data set was collected including real-time images of a variety of target scenes with resolutions as fine as 4 inches. This paper offers a sampling of real-time, high quality, fine resolution images representative of the output of Sandia's miniSAR radar. Images will be annotated with descriptions of collection geometries and other relevant image parameters. The miniSAR system and Sandia DeHaviland DHC-6 Twin Otter test bed are also briefly discussed. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Sweet, AD (reprint author), Sandia Natl Labs, POB 5800,MS 0519, Albuquerque, NM 87185 USA. NR 1 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 0-8194-6266-7 J9 P SOC PHOTO-OPT INS PY 2006 VL 6210 BP 21006 EP 21006 AR 621006 DI 10.1117/12.667615 PG 10 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA BES16 UT WOS:000239242100006 ER PT S AU Ormesher, RC Martinez, A Plummer, KW AF Ormesher, Richard C. Martinez, Ana Plummer, Kenneth W. BE Trebits, RN Kurtz, JL TI Current test results for the athena radar responsive tag - art. no. 62100K SO Radar Sensor Technology X SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Radar Sensor Technology X CY APR 20-21, 2006 CL Kissimmee, FL SP SPIE DE radar; RF tag; CID; SAR; GMTI AB Sandia National Laboratories has teamed with General Atomics and Sierra Monolithics to develop the Athena tag for the Army's Radar Tag Engagement (RaTE) program. The radar-responsive Athena tag can be used for Blue Force tracking and Combat Identification (CID) as well as data collection, identification, and geolocation applications. The Athena tag is small (similar to 4.5" x 2.4" x 4.2"), battery-powered, and has an integral antenna. Once remotely activated by a Synthetic Aperture Radar (SAR) or Moving Target Indicator (MTI) radar, the tag transponds modulated pulses to the radar at a low transmit power. The Athena tag can operate Ku-band and X-band airborne SAR and MTI radars. This paper presents results from current tag development testing activities. Topics covered include recent field tests results from the AN/APY-8 Lynx, F16/APG-66, and F15E/APG-63 V(1) radars and other Fire Control radars. Results show that the Athena tag successfully works with multiple radar platforms, in multiple radar modes, and for multiple applications. Radar-responsive tags such as Athena have numerous applications in military and government arenas. Military applications include battlefield situational awareness, combat identification, targeting, personnel recovery, and unattended ground sensors. Government applications exist in nonproliferation, counter-drug, search-and-rescue, and land-mapping activities. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AL85000. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Ormesher, RC (reprint author), Sandia Natl Labs, POB 5800,MS 0519, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 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 0-8194-6266-7 J9 P SOC PHOTO-OPT INS PY 2006 VL 6210 BP K2100 EP K2100 AR 62100K DI 10.1117/12.664623 PG 11 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA BES16 UT WOS:000239242100020 ER PT B AU Moses, WW Gayshan, V Gektin, A AF Moses, William W. Gayshan, Vadim Gektin, Alexandr BE Tavernier, S Gektin, A Grinyov, B M oses, WW TI The evolution of SPECT - From anger to today and beyond SO Radiation Detectors for Medical Applications SE NATO SECURITY THROUGH SCIENCE SERIES B: PHYSICS AND BIOPHYSICS LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Radiation Detectors for Medical Applications CY SEP 19-23, 2005 CL Alushta, UKRAINE SP NATO Sci Comm DE SPECT; single photon emission computed tomography; nuclear medicine; scintillators ID ENERGY-RESOLUTION SCINTILLATOR; GAMMA-RAY; CAMERA; LIMITATIONS; ADVANTAGES; EFFICIENT; LACL3-CE; PET AB This chapter gives an overview of SPECT (Single Photon Emission Computed Tomography), a nuclear medical imaging technique that has been used for over fifty years to probe the physiology of disease in patients. The emphasis is not on the medical aspects, but instead on the physics and engineering of the imaging system. Special attention is given to the scintillators and the Anger camera used to detect and image the gamma radiation that is emitted by the patient. The requirements, current state-of-the-art, and future developments are all discussed. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Moses, WW (reprint author), Lawrence Berkeley Natl Lab, Mailstop 15-121,1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 31 TC 3 Z9 3 U1 0 U2 3 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 978-1-4020-5092-3 J9 NATO SEC SCI B PHYS PY 2006 BP 37 EP 80 DI 10.1007/1-4020-5093-3_3 PG 44 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA BFU93 UT WOS:000244738500003 ER PT J AU Guilderson, TP Roark, EB Quay, PD Page, SRF Moy, C AF Guilderson, TP Roark, EB Quay, PD Page, SRF Moy, C TI Seawater radiocarbon evolution in the Gulf of Alaska: 2002 observations SO RADIOCARBON LA English DT Article ID PACIFIC INTERMEDIATE WATER; NORTH PACIFIC; OCEAN; AMS; CHLOROFLUOROCARBONS; VENTILATION AB Oceanic uptake and transport of bomb radiocarbon as (CO2)-C-14 created by atmospheric nuclear weapons testing in the 1950s and 1960s has been a useful diagnostic for determining the carbon transfer between the ocean and atmosphere. In addition, the distribution of C-14 in the ocean can be used as a tracer of oceanic circulation. Results obtained on samples collected in the Gulf of Alaska in the summer of 2002 provide a direct comparison with results in the 1970s during GEOSECS and in the early 1990s during WOCE. The open gyre values are 20-40 parts per thousand lower than those documented in 1991 and 1993 (WOCE), although the general trends as a function of latitude are reproduced. Surface values are still significantly higher than pre-bomb levels (similar to -105 parts per thousand or lower). In the central gyre, we observe Delta C-14 values that are lower in comparison to GEOSECS (stn 218) and WOCE P16/P17 to a density of similar to 26.8 sigma(i). This observation is consistent with the overall decrease in surface Delta C-14 values and reflects the erosion of the bomb-C-14 transient. We propose that erosion of the bomb-14C transient is accomplished by entrainment of low-C-14 water via vertical exchange within the Gulf of Alaska and replenishment of surface and subthermocline waters with waters derived from the far northwest Pacific. C1 Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. Univ Calif Santa Cruz, Dept Ocean Studies, Santa Cruz, CA 94056 USA. Univ Calif Berkeley, Dept Geog, Berkeley, CA 94720 USA. Univ Washington, Sch Oceanog, Seattle, WA 98195 USA. Univ Calif Santa Cruz, Dept Biol Sci, Santa Cruz, CA 94056 USA. Stanford Univ, Dept Geol & Environm Sci, Stanford, CA 94305 USA. RP Guilderson, TP (reprint author), Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. EM tguilderson@llnl.gov RI Roark, Erin/D-4124-2013 OI Roark, Erin/0000-0002-1742-9642 NR 28 TC 11 Z9 11 U1 0 U2 8 PU UNIV ARIZONA DEPT GEOSCIENCES PI TUCSON PA RADIOCARBON 4717 E FORT LOWELL RD, TUCSON, AZ 85712 USA SN 0033-8222 J9 RADIOCARBON JI Radiocarbon PY 2006 VL 48 IS 1 BP 1 EP 15 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 031IE UT WOS:000236697100001 ER PT J AU Harbottle, G AF Harbottle, G TI Untitled SO RADIOCARBON LA English DT Letter ID VINLAND MAP; PARCHMENT C1 Brookhaven Natl Lab, Upton, NY 11973 USA. SUNY Stony Brook, Dept Geosci, Stony Brook, NY 11791 USA. RP Harbottle, G (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 23 TC 0 Z9 0 U1 0 U2 1 PU UNIV ARIZONA DEPT GEOSCIENCES PI TUCSON PA RADIOCARBON 4717 E FORT LOWELL RD, TUCSON, AZ 85712 USA SN 0033-8222 J9 RADIOCARBON JI Radiocarbon PY 2006 VL 48 IS 1 BP 123 EP 126 PG 4 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 031IE UT WOS:000236697100011 ER PT J AU Getachew, G Kim, SH Burri, BJ Kelly, PB Haack, KW Ognibene, TJ Buchholz, BA Vogel, JS Modrow, J Clifford, AJ AF Getachew, Girma Kim, Seung-Hyun Burri, Betty J. Kelly, Peter B. Haack, Kurt W. Ognibene, Ted J. Buchholz, Bruce A. Vogel, John S. Modrow, Jonathan Clifford, Andrew J. TI How to convert biological carbon into graphite for AMS SO RADIOCARBON LA English DT Article ID ACCELERATOR MASS-SPECTROMETRY; BETA-CAROTENE; C-14; SAMPLES AB Isotope tracer studies, particularly radiocarbon measurements, play a key role in biological, nutritional, and environmental research. Accelerator mass spectrometry (AMS) is now the most sensitive detection method for C-14, but AMS is not widely used in kinetic studies of humans. Part of the reason is the expense, but costs would decrease if AMS were used more widely. One component in the cost is sample preparation for AMS. Biological and environmental samples are commonly reduced to graphite before they are analyzed by AMS. Improvements and mechanization of this multistep procedure is slowed by a lack of organized educational materials for AMS sample preparation that would allow new investigators to work with the technique without a substantial outlay of time and effort. We present a detailed sample preparation protocol for graphitizing biological samples for AMS and include examples of nutrition studies that have used this procedure. C1 Univ Calif Davis, Dept Nutr, Davis, CA 95616 USA. USDA, Western Human Nutr Res Ctr, Davis, CA 95616 USA. Univ Calif Davis, Dept Chem, Davis, CA 95616 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Clifford, AJ (reprint author), Univ Calif Davis, Dept Nutr, Davis, CA 95616 USA. EM ajclifford@ucdavis.edu RI Buchholz, Bruce/G-1356-2011 NR 15 TC 15 Z9 15 U1 0 U2 8 PU UNIV ARIZONA DEPT GEOSCIENCES PI TUCSON PA RADIOCARBON 4717 E FORT LOWELL RD, TUCSON, AZ 85712 USA SN 0033-8222 J9 RADIOCARBON JI Radiocarbon PY 2006 VL 48 IS 3 BP 325 EP 336 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 121GN UT WOS:000243146200003 ER PT J AU Andersson, S Nitsche, H Sudowe, R AF Andersson, S Nitsche, H Sudowe, R TI Berkelium nitrate complex formation using a solvent extraction technique SO RADIOCHIMICA ACTA LA English DT Article DE berkelium; nitrate complex formation; solvent extraction ID TRIVALENT ACTINIDE IONS; STABILITY-CONSTANTS; THIOCYANATE; AM; EU AB The extraction of Bk(III) into an organic phase consisting of 2,6-bis-(benzoxazolyl)-4-dodecyloxylpyridine, 2-bromodecanoic acid and tert-butyl benzene as a function of nitrate ion concentration in the aqueous phase was studied in order to determine the stability constants of the formation of Bk nitrate complexes. Increasing the nitrate ion concentration in the aqueous phase will increase the nitrate complex formation and thus the extraction of metal ions will decrease. Measuring this decrease in distribution ratio and fitting the data points with an appropriate model gives the stability constants of the Bk nitrate complex formation. C1 Chalmers Univ Technol, S-41296 Gothenburg, Sweden. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Berkeley, CA USA. RP Andersson, S (reprint author), Chalmers Univ Technol, S-41296 Gothenburg, Sweden. EM sofie.andersson@chem.chalmers.se NR 14 TC 1 Z9 1 U1 0 U2 3 PU OLDENBOURG VERLAG PI MUNICH PA LEKTORAT MINT, POSTFACH 80 13 60, D-81613 MUNICH, GERMANY SN 0033-8230 J9 RADIOCHIM ACTA JI Radiochim. Acta PY 2006 VL 94 IS 1 BP 59 EP 61 DI 10.1524/ract.2006.94.1.59 PG 3 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 010ZH UT WOS:000235236900009 ER PT J AU Sudowe, R Calvert, MG Dullmann, CE Farina, LM Folden, CM Gregorich, KE Gallaher, SEH Hoffman, DC Nelson, SL Phillips, DC Schwantes, JM Wilson, RE Zielinski, PM Nitsche, H AF Sudowe, R Calvert, MG Dullmann, CE Farina, LM Folden, CM Gregorich, KE Gallaher, SEH Hoffman, DC Nelson, SL Phillips, DC Schwantes, JM Wilson, RE Zielinski, PM Nitsche, H TI Extraction of short-lived zirconium and hafnium isotopes using crown ethers: A model system for the study of rutherfordium SO RADIOCHIMICA ACTA LA English DT Article DE zirconium; hafnium; crown ether; liquid-liquid extraction; distribution ratio; separation factor ID COMPLEXES; CHEMISTRY; SEPARATION; ELEMENTS; HEAVY; ZR; HF AB The extraction of zirconium and hafnium, from hydrochloric acid media was studied using the crown ethers dibenzo-18-crown-6 (DB18C6), dicyclohexano-18-crown-6 (DC18C6) and dicyclohexano-24-crown-8 (DC24C8) as extractants. The goal was to find an extraction system that exhibits a high selectivity between the members of group 4 of the periodic table and is suitable for the study of rutherfordium. It was found that Zr and Hf are both extracted using DB18C6, DC18C6 and DC24C8. The extraction yield increases with increasing acid concentration and increasing concentration of crown ether. The extracted species most likely consists of an ion-association complex formed between a Zr or Hf chloro complex and a hydronium crown ether complex. Conditions can be found for each extractant that provide for the separation of Zr from Hf. This selective separation between Zr and Hf makes the extraction with crown ethers from HCl well suited to study the extraction behaviour of Rf and compare it to the behaviour of Zr and Hf. These extraction systems can be used to determine whether the extraction behaviour of Rf is similar to Zr, similar to Hf or follows the trend established by the lighter homologs. The extraction kinetics are fast enough for the study of the 78-s isotope (261m)Rf. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Sudowe, R (reprint author), Los Alamos Natl Lab, Div Chem, POB 1663, Los Alamos, NM 87545 USA. EM RSudowe@lbl.gov RI Schwantes, Jon/A-7318-2009; Wilson, Richard/H-1763-2011; Folden, Charles/F-1033-2015 OI Wilson, Richard/0000-0001-8618-5680; Folden, Charles/0000-0002-2814-3762 NR 20 TC 17 Z9 17 U1 0 U2 3 PU OLDENBOURG VERLAG PI MUNICH PA LEKTORAT MINT, POSTFACH 80 13 60, D-81613 MUNICH, GERMANY SN 0033-8230 J9 RADIOCHIM ACTA JI Radiochim. Acta PY 2006 VL 94 IS 3 BP 123 EP 129 DI 10.1524/ract.2006.94.3.123 PG 7 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 028EM UT WOS:000236469700001 ER PT J AU Xia, YX Hess, NJ Felmy, AR AF Xia, YX Hess, NJ Felmy, AR TI Stability constants of technetium(IV) oxalate complexes as a function of ionic strength SO RADIOCHIMICA ACTA LA English DT Article DE technetium(IV); oxalate; complexation; stability constants; solvent extraction; specific ionic interaction theory AB Solvent extraction method was used to determine the stability constants of Tc(IV) with oxalate anions in NaCl solutions ranging in concentration from 0.5 M to 2.0 M. All experiments were conducted in an atmosphere-controlled chamber under Ar atmosphere (< 1.0 ppm O-2). A reducing agent (hydrazine) was used during extractions to maintain technetium in the tetravalent oxidation state. Independent tests confirmed that the oxidation state of technetium did not change during extractions. The distribution ratio of Tc(IV) between the organic and aqueous phases was found to decrease as the concentration of oxalic acid increased. At the oxalic acid concentrations used in these experiments, the complexes TcO(Ox) and TcO(Ox)(2)(2-) were found to be the dominant aqueous species. Based on these data, the thermodynamic stability constants of Tc(IV) with oxalate complexes were calculated by the Specific Ion Interaction Theory (SIT). C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Hess, NJ (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. EM nancy.hess@pnl.gov OI Hess, Nancy/0000-0002-8930-9500 NR 17 TC 14 Z9 14 U1 1 U2 10 PU OLDENBOURG VERLAG PI MUNICH PA LEKTORAT MINT, POSTFACH 80 13 60, D-81613 MUNICH, GERMANY SN 0033-8230 J9 RADIOCHIM ACTA JI Radiochim. Acta PY 2006 VL 94 IS 3 BP 137 EP 141 DI 10.1524/ract.2006.94.3.137 PG 5 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 028EM UT WOS:000236469700003 ER PT J AU Gombert, D Karraker, D Drake, R AF Gombert, D Karraker, D Drake, R TI Evaluation of cerium(IV) catalyzed remediation of plutonium contaminated soils at the Idaho Cleanup Project SO RADIOCHIMICA ACTA LA English DT Article DE soil decontamination; Pit 9; plutonium; plutonium oxide; Idaho AB An engineering and analytical chemical program was used to evaluate a proposed process to remove plutonium from contaminated soils at the Department of Energy's Idaho National Engineering and Environmental Laboratory Site. The design was based on the premise that the chemical process would be extremely efficient, reducing up to 250 nCi/g total transuranic contamination including both plutonium, in several chemical forms, and americium to less than 10 nCi/g. To ensure the effectiveness of the process on even heat-treated forms of plutonium, a very aggressive cerium IV catalyzed hot nitric acid leach step was used. Laboratory experiments showed that the chemistry could indeed remove plutonium, but due to the secondary wastes generated by coincident dissolution of the soil matrix, the process did not meet other design requirements. C1 Idaho Natl Engn Lab, Idaho Falls, ID 83415 USA. Savannah River Ecol Lab, Aiken, SC 29801 USA. Drake Engn, Helena, MT 59601 USA. RP Gombert, D (reprint author), Idaho Natl Engn Lab, 2525 Fremont Ave, Idaho Falls, ID 83415 USA. EM dirk.gombert@inl.gov NR 26 TC 1 Z9 1 U1 1 U2 5 PU OLDENBOURG VERLAG PI MUNICH PA LEKTORAT MINT, POSTFACH 80 13 60, D-81613 MUNICH, GERMANY SN 0033-8230 J9 RADIOCHIM ACTA JI Radiochim. Acta PY 2006 VL 94 IS 3 BP 167 EP 173 DI 10.1524/ract.2006.94.3.167 PG 7 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 028EM UT WOS:000236469700008 ER PT J AU Eichler, R Bruchle, W Buda, R Burger, S Dressler, R Dullmann, CE Dvorak, J Eberhardt, K Eichler, B Folden, CM Gaggeler, HW Gregorich, KE Haenssler, F Hoffman, DC Hummrich, H Jager, E Kratz, JV Kuczewski, B Liebe, D Nayak, D Nitsche, H Piguet, D Qin, Z Rieth, U Schadel, M Schausten, B Schimpf, E Semchenkov, A Soverna, S Sudowe, R Trautmann, N Thorle, P Turler, A Wierczinski, B Wiehl, N Wilk, PA Wirth, G Yakushev, AB von Zweidorf, A AF Eichler, R Bruchle, W Buda, R Burger, S Dressler, R Dullmann, CE Dvorak, J Eberhardt, K Eichler, B Folden, CM Gaggeler, HW Gregorich, KE Haenssler, F Hoffman, DC Hummrich, H Jager, E Kratz, JV Kuczewski, B Liebe, D Nayak, D Nitsche, H Piguet, D Qin, Z Rieth, U Schadel, M Schausten, B Schimpf, E Semchenkov, A Soverna, S Sudowe, R Trautmann, N Thorle, P Turler, A Wierczinski, B Wiehl, N Wilk, PA Wirth, G Yakushev, AB von Zweidorf, A TI Attempts to chemically investigate element 112 SO RADIOCHIMICA ACTA LA English DT Article DE adsorption; transactinides; element 112; thermochromatography ID SUPERHEAVY ELEMENTS; HEAVIEST ELEMENTS; METAL-SURFACES; ION REACTIONS; ADSORPTION; NUCLEAR; HASSIUM; RADON; SEPARATOR; CHEMISTRY AB Two experiments aiming at the chemical investigation of element 112 produced in the heavy ion induced nuclear fusion reaction of Ca-48 with U-238 were performed at the Geselischaft fur Schwerionenforschung (GSI), Darmstadt, Germany. Both experiments were designed to determine the adsorption enthalpy of element 112 on a gold surface using a thermochromatography setup. The temperature range covered in the thermochromatography experiments allowed the adsorption of Hg at about 35 degrees C and of Rn at about - 180 degrees C. Reports from the Flerov Laboratory for Nuclear Reactions (FLNR), Dubna, Russia claim production of a 5-min spontaneous fission (SF) activity assigned to 2111 12 for the U-238 (Ca-48,3n) (283)112 reaction. Hence, Experiment I was designed to detect spontaneously fissioning (SF) isotopes of elernent 112 with half-lives (t(1/2)) longer than about 20 s. 11 high-energy events were detected. 7 events exhibit a deposlition pattern resembling a chromatographic peak in the vicinity of Rn deposition. However, the energy of the events observed in Experiment I was lower than expected for a SF-decay of (283)112. Therefore, these events could not be unambiguously attributed to the decay of (283)112. In contradiction with earlier publications newer reports from FLNR Dubna claim that (283)12 decays by a-particle ernission (E-alpha = 9.5 MeV) with t(1/2) = 4 s followed by a SF-decay of (279)Ds (t(1/2) = 0.2 s). Therefore, Experiment II was designed to be sensitive to both claimed decay properties of (283)112. However, during this experiment neither short alpha-SF correlations nor SF coincidences were detected. The conclusion is that (283)112 was not unambiguously detected, neither in Experiment I nor in Experiment II. C1 Paul Scherrer Inst, Labor Radio & Umweltchem, CH-5232 Villigen, Switzerland. Univ Bern, Dept Chem & Biochem, CH-3012 Bern, Switzerland. Gesellsch Schwerionforsch mbH, D-64291 Darmstadt, Germany. Johannes Gutenberg Univ Mainz, Inst Kernchem, D-55099 Mainz, Germany. Lawrence Berkeley Lab, Nucl Sci Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Tech Univ Munich, Inst Radiochem, D-85748 Garching, Germany. Saha Inst Nucl Phys, Chem Sci Div, Kolkata 700064, India. Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000, Peoples R China. RP Eichler, R (reprint author), Paul Scherrer Inst, Labor Radio & Umweltchem, CH-5232 Villigen, Switzerland. EM robert.eichler@psi.ch RI Wilk, Philip/B-5954-2008; Eichler, Robert/G-5130-2011; Folden, Charles/F-1033-2015; Turler, Andreas/D-3913-2014 OI Folden, Charles/0000-0002-2814-3762; Turler, Andreas/0000-0002-4274-1056 NR 50 TC 46 Z9 46 U1 1 U2 5 PU WALTER DE GRUYTER GMBH PI BERLIN PA GENTHINER STRASSE 13, D-10785 BERLIN, GERMANY SN 0033-8230 J9 RADIOCHIM ACTA JI Radiochim. Acta PY 2006 VL 94 IS 4 BP 181 EP 191 DI 10.1524/ract.2006.94.4.181 PG 11 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 038BF UT WOS:000237191900001 ER PT J AU Felmy, AR Cho, H Dixon, DA Xia, YX Hess, NJ Wang, ZM AF Felmy, AR Cho, H Dixon, DA Xia, YX Hess, NJ Wang, ZM TI The aqueous complexation of thorium with citrate under neutral to basic conditions SO RADIOCHIMICA ACTA LA English DT Article DE thorium; citrate; aqueous; solution; structure; equilibrium constant ID FUNCTIONAL THEORY CALCULATIONS; RAY CRYSTAL-STRUCTURE; STRUCTURAL-CHARACTERIZATION; NATURAL-WATERS; RAMAN-SPECTROSCOPY; SOLUTION BEHAVIOR; NMR-SPECTROSCOPY; IONIC-STRENGTH; DENSITY; SOLUBILITY AB The aqueous complexation of thorium with citrate was investigated under neutral to basic conditions and over a broad range of ionic strengths. The solubility data for ThO2(am) as a function of citrate concentration indicate the presence of stable species with citrate-to-metal ratios of between two to three. The dependence of the ThO2(am) solubilities on hydrogen ion concentration can also be readily explained by the classical assumption of hydrolysis of the central Th(IV) ion to form mixed thorium-hydroxide-citrate complexes. C-13 NMR spectra of the species in solution confirm that the citrate-to-metal ratio of the species in solution is between two and three and show that the citrate attaches to the metal in a bidentate fashion through oxygens on the alpha-carboxylate and alpha-alkoxyl groups, rather than through the carboxylate groups. The C-13 NMR spectra, as well as a density functional theory (DFT) electronic structure study of the presumptive complexes, suggests that the associated alpha-hydroxyl proton can be displaced during complex formation. These findings indicate an alternative explanation for the observed changes in solubility as a function of hydrogen ion concentration, the displacement of protons from the citrate alkoxyl groups via metal binding. Removal of protons from the alkoxyl groups or hydrolysis of the central Th(IV) cannot be distinguished by thermodynamic measurements, however the species with the alpha-hydroxyl proton removed (i.e. ThOH(Cit)(2)(5-) and Th(Cit)(3)(8-)) would appear to better represent the microscopic binding. Apparent equilibrium constants for the solution phase reactions of these species and the hydrous thorium oxide have been calculated as a function of ionic strength. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Alabama, Tuscaloosa, AL USA. RP Felmy, AR (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. EM ar.felmy@pnl.gov RI Wang, Zheming/E-8244-2010; OI Wang, Zheming/0000-0002-1986-4357; Hess, Nancy/0000-0002-8930-9500 NR 41 TC 7 Z9 7 U1 0 U2 12 PU OLDENBOURG VERLAG PI MUNICH PA LEKTORAT MINT, POSTFACH 80 13 60, D-81613 MUNICH, GERMANY SN 0033-8230 J9 RADIOCHIM ACTA JI Radiochim. Acta PY 2006 VL 94 IS 4 BP 205 EP 212 DI 10.1524/ract.2006.94.4.205 PG 8 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 038BF UT WOS:000237191900004 ER PT J AU Pepper, SE Hull, LC Bottenus, BN Clark, SB AF Pepper, SE Hull, LC Bottenus, BN Clark, SB TI Adsorption of lanthanum to goethite in the presence of gluconate SO RADIOCHIMICA ACTA LA English DT Article DE lanthanum; adsorption; goethite; gluconate ID IRON-OXIDES; DEGRADATION-PRODUCTS; STEEL SURFACES; SORPTION; COMPLEXES; ACID; MINERALS; URANIUM; CADMIUM; NEPTUNIUM(V) AB We have examined the effect of the gluconate anion, an analogue for cellulose degradation products, on the adsorption of trivalent lanthanum (Lal(3+))(#) to goethite. Lanthanum is investigated as an analogue for the trivalent actinides. Batch pH adsorption edge experiments were used to quantify the adsorption of La3+ in the absence of gluconate and in solutions where gluconate was present at a 1 : 1 mole ratio to lanthanum. Using available thermodynamic data, it is calculated that lanthanum is primarily present in solution as the free La3+ ion at pH values up to 8.5 in the absence of gluconate. Above pH 8.5, solid La(OH)(3) precipitates from solution. In the presence of gluconate, complexation decreases the free La3+ concentration in solution. The fraction of La3+ complexed increases, from 3% to 50%, as the concentrations of La3+ and gluconate were increased. Very little effect on the adsorption of La3+ to goethite was observed in the presence of gluconate below pH 7. At pH values above 7, however, gluconate doubled the maximum amount of La3+ adsorbed when present at concentrations that saturated the goethite adsorption sites. The presence of gluconate did not appear to inhibit the formation of La(OH)(3)(s) at pH 8.5 and milli molar lanthanum concentrations. Adsorption to the goethite surface was represented with a surface complexation approach using the diffuse double-layer model. Intrinsic binding constants for the surface complexes were estimated from the pH adsorption edge data using the computer code FITEQL 4.0 and visual curve fitting. Two surface reactions were used to fit the adsorption data in the absence of gluconate: 1) a strong binding site with no proton release and 2) a much higher concentration of weak binding sites with release of two protons per La3+ adsorbed. In the presence of gluconate, a third surface complex was needed that involved a ternary complex of two lanthanum atoms with one gluconate molecule. C1 Washington State Univ, Dept Chem, Pullman, WA 99164 USA. Idaho Natl Lab, Geosci Dept, Idaho Falls, ID 83415 USA. RP Pepper, SE (reprint author), Washington State Univ, Dept Chem, Pullman, WA 99164 USA. EM spepper@wsu.edu NR 51 TC 8 Z9 8 U1 2 U2 9 PU WALTER DE GRUYTER GMBH PI BERLIN PA GENTHINER STRASSE 13, D-10785 BERLIN, GERMANY SN 0033-8230 J9 RADIOCHIM ACTA JI Radiochim. Acta PY 2006 VL 94 IS 4 BP 229 EP 237 DI 10.1524/ract.2006.94.4.229 PG 9 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 038BF UT WOS:000237191900008 ER PT J AU Ding, M Conca, JL den Auwer, C Gabitov, RI Hess, NJ Paviet-Hartmann, P Palmer, PD LoPresti, V Conradson, SD AF Ding, M Conca, JL den Auwer, C Gabitov, RI Hess, NJ Paviet-Hartmann, P Palmer, PD LoPresti, V Conradson, SD TI Chemical speciation of heterogeneously reduced Pu in synthetic brines SO RADIOCHIMICA ACTA LA English DT Article DE plutonium hydrous oxide; reduction; active barrier technology; XAFS; chemical speciation; local structure ID CHARGE-DISTRIBUTION; ALKALI SOLUTIONS; AQUEOUS-SOLUTION; LOCAL-STRUCTURE; PLUTONIUM; SOLUBILITY; NACL; HYDROLYSIS; PU(VI); RADIOLYSIS AB X-ray absorption fine structure (XAFS) spectroscopy has been used to determine the speciation of Pu precipitates prepared by the heterogeneous reduction of Pu(VI) with Al and Fe in 5 M NaCl and an ERDA-6 brine, a simulant from the Waste Isolation Pilot Plant in Carlsbad, New Mexico. NaOCl was added to some of these solutions to determine its effect on Pu speciation. Analysis of the Pu L-III spectra showed that all solids consisted of PuO2+x-y (OH)(2y)(.)zH(2)O, compounds with characteristics identical to those prepared by hydrolysis and with Pu-O and Pu-Pu distances identical to those treated at elevated temperature. Additionally, reduction with Al gave compounds with different site distributions than reduction with Fe, and reduction with Al or the addition of NaOCl appeared to suppress the formation of oxo groups and their associated Pu(V) sites. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. CEA Marcoule, F-30207 Bagnols sur Ceze, France. Rensselaer Polytech Inst, Troy, NY 12180 USA. Russian Acad Sci, Inst Expt Mineral, Chernogolovka 142432, Russia. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Conradson, SD (reprint author), Los Alamos Natl Lab, MST-8 MS G755, Los Alamos, NM 87545 USA. EM conradson@lanl.gov OI Hess, Nancy/0000-0002-8930-9500 NR 54 TC 2 Z9 2 U1 0 U2 9 PU OLDENBOURG VERLAG PI MUNICH PA LEKTORAT MINT, POSTFACH 80 13 60, D-81613 MUNICH, GERMANY SN 0033-8230 J9 RADIOCHIM ACTA JI Radiochim. Acta PY 2006 VL 94 IS 5 BP 249 EP 259 DI 10.1524/ract.2006.94.5.249 PG 11 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 048AS UT WOS:000237920400003 ER PT J AU Law, JD Peterman, DR Todd, TA Tillotson, RD AF Law, JD Peterman, DR Todd, TA Tillotson, RD TI Separation of trivalent actinides from lanthanides in an acetate buffer solution using Cyanex 301 SO RADIOCHIMICA ACTA LA English DT Article DE cyanex; actinide; lanthanide; solvent extraction; separation ID EXTRACTION; AMERICIUM AB The separation of trivalent actinides from the lanthanides using the active extractant in the Cyanex 301 reagent, bis(2,4,4-trimethylpentyl)dithiophosphinic acid, was studied. Specifically, the extractant was studied with an ammonium acetate/acetic acid buffered feed that would result from a transuranic separation process utilizing an ammonium acetate strip solution. Separation factors of Am-241 from Eu-154 with this extractant, as a function of total acetate concentration and pH, have been measured. Additionally, the extraction behavior of stable La, Ce, Pr, Nd, Sm and Eu was measured. Separation factors were typically very high for Am from Eu at a pH ranging from 3.8 to 5.8 and a total acetate concentration ranging from 0.2 M to 1.0 M. However, separation factors across the lanthanide series varied considerably and resulted in separation of the lighter lanthanides from the heavier lanthanides at the higher pH's. C1 Idaho Natl Lab, Idaho Falls, ID 83415 USA. RP Law, JD (reprint author), Idaho Natl Lab, POB 1625, Idaho Falls, ID 83415 USA. EM Jack.Law@inl.gov RI Todd, Terry /O-4930-2016; OI Todd, Terry /0000-0003-1324-6950; Law, Jack/0000-0001-7085-7542 NR 24 TC 25 Z9 26 U1 0 U2 12 PU OLDENBOURG VERLAG PI MUNICH PA LEKTORAT MINT, POSTFACH 80 13 60, D-81613 MUNICH, GERMANY SN 0033-8230 J9 RADIOCHIM ACTA JI Radiochim. Acta PY 2006 VL 94 IS 5 BP 261 EP 266 DI 10.1524/ract.2006.94.5.261 PG 6 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 048AS UT WOS:000237920400004 ER PT J AU Zhang, Z Clark, SB Tian, G Zanonato, PL Rao, L AF Zhang, Z. Clark, S. B. Tian, G. Zanonato, P. L. Rao, L. TI Protonation of D-gluconate and its complexation with Np(V) in acidic to nearly neutral solutions SO RADIOCHIMICA ACTA LA English DT Article; Proceedings Paper CT 10th International Conference on Chemistry and Migration of Actinides and Fission Products CY SEP 18-23, 2005 CL Avignon, FRANCE SP Commissariat Energie Atom, CNRS DE gluconic acid; neptunium; complexation; stability constant; enthalpy ID NUCLEAR-MAGNETIC-RESONANCE; VARIABLE TEMPERATURES; ISOSACCHARINIC ACID; URANIUM(VI); HYDROLYSIS; EQUILIBRIA; CONSTANTS; ACETATE; LACTONE AB Thermodynamic properties of the protonation of D-gluconic acid (HGH(4)(aq)) and its complexation with Np(V) have been studied in acidic to nearly neutral solutions at t = 25 degrees C and I = 1 M NaClO4 by potentiometry, spectrophotometry and calorimetry. The protonation constant (log K-H) and enthalpy (Delta H-H) of the carboxylate group are determined to be (3.30 +/- 0.10) and -(4.03 +/- 0.07) kJ mol(-1), respectively. Gluconate forms two Np(V) complexes in nearly neutral solutions. The formation constants and enthalpies of complexation are: log beta(1) = (1.48 +/- 0.03) and Delta H-1 = - (7.42 +/- 0.13) kJ mol(-1) for NpO2 (GH(4)) (aq), log beta(2) = (2.14 +/- 0.09) and Delta H-2 = - (12.08 +/- 0.45) kJ mol(-1) for NpO2 (GH(4))(2)(-). The thermodynamic parameters indicate that gluconic acid, like isosaccharinic acid and other alpha-hydroxycarboxylic acids, is a slightly stronger acid and forms stronger complexes with Np(V) than simple monocarboxylic acids. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Washington State Univ, Pullman, WA 99164 USA. Univ Padua, Dipartimento Sci Chim, I-35131 Padua, Italy. RP Clark, SB (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. EM s_clark@wsu.edu RI Zhang, Zhicheng/B-3887-2010 NR 25 TC 8 Z9 8 U1 1 U2 5 PU OLDENBOURG VERLAG PI MUNICH PA LEKTORAT MINT, POSTFACH 80 13 60, D-81613 MUNICH, GERMANY SN 0033-8230 J9 RADIOCHIM ACTA JI Radiochim. Acta PY 2006 VL 94 IS 9-11 BP 531 EP 536 DI 10.1524/ract.2006.94.9.531 PG 6 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 149FY UT WOS:000245133700008 ER PT J AU Suzuki, Y Nankawa, T Yoshida, T Ozaki, T Ohnuki, T Francis, AJ Tsushima, S Enokida, Y Yamamoto, I AF Suzuki, Y. Nankawa, T. Yoshida, T. Ozaki, T. Ohnuki, T. Francis, A. J. Tsushima, S. Enokida, Y. Yamamoto, I. TI Reduction behavior of uranium in the presence of citric acid SO RADIOCHIMICA ACTA LA English DT Article; Proceedings Paper CT 10th International Conference on Chemistry and Migration of Actinides and Fission Products CY SEP 18-23, 2005 CL Avignon, FRANCE SP Commissariat Energie Atom, CNRS DE uranium-citrate complex; reduction; speciation; column electrode; absorption spectrum ID URANYL-ION; COMPLEXES; SPECIATION; CHEMISTRY; CITRATE AB We examined the reduction behavior of UO22+ in citrate media at pH 2.0-7.0 by column electrodes. At pH 2.0, UO22+ was reduced to U(IV) through a one-step reduction process, while it was reduced to U(IV) through a two-step reduction process at pH 3.0-5.0. The reduction potential of UO22+ shifted to lower values with an increase in pH from 2.0 to 7.0. At pH 6.0 and 7.0, UO22+ was not reduced to U(IV) completely at the electrode potential above -0.8V vs. silver/silver chloride electrode. Ultraviolet-visible spectroscopy and speciation calculation of UO22+ in citrate media indicated that uranium existed as a mixture of UO22+, [UO(2)Cit](-) and [(UO2)(2)Cit(2)](2-) at pH 2-3, and a predominant species at pH 3-5 was [(UO2)(2)Cit(2)](2-) (H(3)Cit: citric acid). At pH 5-7, polymeric complexes, probably, [(UO2)(3)Cit(3)](3-) and [(UO2)(6)Cit(6)(OH)(10)](16-) were present. These findings suggest that the reduction of UO22+ is more difficult by polymerization of UO22+ with citric acid at higher pHs. Absorption spectra of the reduced complexes showed that U(IV) forms soluble complexes with citric acid at pH 2.0-5.0, and presence of U(V) species was not observed during the reduction of UO22+. C1 Nagoya Univ, Dept Mat Phys & Energy Engn, Grad Sch Engn, Chikusa Ku, Nagoya, Aichi 4648603, Japan. Japan Atom Energy Res Inst, Adv Sci Res Ctr, Tokai, Ibaraki 3191195, Japan. Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA. Nagoya Univ, EcoTopia Sci Inst, Chikusa Ku, Nagoya, Aichi 4648603, Japan. RP Suzuki, Y (reprint author), Nagoya Univ, Dept Mat Phys & Energy Engn, Grad Sch Engn, Chikusa Ku, Furo Cho, Nagoya, Aichi 4648603, Japan. EM suzuki.yoshinori@jaea.go.jp RI Tsushima, Satoru/B-4103-2008; Yamamoto, Ichiro/I-4226-2012 OI Tsushima, Satoru/0000-0002-4520-6147; NR 27 TC 12 Z9 12 U1 2 U2 10 PU WALTER DE GRUYTER GMBH PI BERLIN PA GENTHINER STRASSE 13, D-10785 BERLIN, GERMANY SN 0033-8230 J9 RADIOCHIM ACTA JI Radiochim. Acta PY 2006 VL 94 IS 9-11 BP 579 EP 583 DI 10.1524/ract.2006.94.9.579 PG 5 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 149FY UT WOS:000245133700016 ER PT J AU Reed, DT Lucchini, JF Aase, SB Kropf, AJ AF Reed, D. T. Lucchini, J. F. Aase, S. B. Kropf, A. J. TI Reduction of plutonium(VI) in brine under subsurface conditions SO RADIOCHIMICA ACTA LA English DT Article; Proceedings Paper CT 10th International Conference on Chemistry and Migration of Actinides and Fission Products CY SEP 18-23, 2005 CL Avignon, FRANCE SP Commissariat Energie Atom, CNRS DE plutonium; WIPP; XANES; iron reduction; brine chemistry ID OXIDATION-STATES; SYNTHETIC BRINE; PU; SOLUBILITY; NP(V); NACL AB The redox stability of PuO22+ was investigated in brine under subsurface conditions. In simulated brines, when no reducing agent was present, 0.1 mM concentrations of plutonium(VI) were stable as regards to reduction for over two years, which was the duration of the experiments performed. In these systems, the plutonyl existed as a carbonate or hydroxy-chloride species. The introduction of reducing agents (e.g. steel coupons, and aqueous Fe2+) typically present in a subsurface repository, however, led to the destabilization of the plutonium(VI) complexes and the subsequent reduction to Pu(IV) under most conditions investigated. X-ray Absorption Near-Edge Spectroscopy (XANES) confirmed that the final oxidation state in these systems was Pu(IV). This reduction lowered the overall steady state concentration of plutonium in the brine by 3-4 orders of magnitude. These results show the importance of considering repository constituents in evaluating subsurface actinide solubility/mobility an provide further evidence of the effectiveness of reduced iron species in the reduction and immobilization of higher-valent plutonium species. C1 Los Alamos Natl Lab, Div Earth & Environm Sci, Carlsbad, NM 88220 USA. Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Reed, DT (reprint author), Los Alamos Natl Lab, Div Earth & Environm Sci, Carlsbad, NM 88220 USA. EM dreed@lanl.gov RI ID, MRCAT/G-7586-2011 NR 18 TC 12 Z9 12 U1 2 U2 10 PU OLDENBOURG VERLAG PI MUNICH PA LEKTORAT MINT, POSTFACH 80 13 60, D-81613 MUNICH, GERMANY SN 0033-8230 J9 RADIOCHIM ACTA JI Radiochim. Acta PY 2006 VL 94 IS 9-11 BP 591 EP 597 DI 10.1524/ract.2006.94.9.591 PG 7 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 149FY UT WOS:000245133700018 ER PT J AU Thakur, P Moore, RC Choppin, GR AF Thakur, P. Moore, R. C. Choppin, G. R. TI Np(V)O-2(+) sorption on hydroxyapatite-effect of calcium and phosphate anions SO RADIOCHIMICA ACTA LA English DT Article; Proceedings Paper CT 10th International Conference on Chemistry and Migration of Actinides and Fission Products CY SEP 18-23, 2005 CL Avignon, FRANCE SP Commissariat Energie Atom, CNRS DE NpO2+; sorption; hydroxyapatite; kinetics; thermodynamics ID SYNTHETIC HYDROXYAPATITE; NEPTUNIUM(V) SORPTION; SURFACE COMPLEXATION; LEAD IMMOBILIZATION; ADSORPTION; STRONTIUM; MINERALS; APATITE; ION; MONTMORILLONITE AB The sorption of NpO2+ from aqueous solution on hydroxyapatite was studied as a function of the amount of sorbent, initial NPO2+ concentration, ionic strength and pcH. The hydroxyapatite was characterized by SEM, EDS, XRD, FIF-IR and ICP-MS measurements. At ionic strengths of 0.10 to 5.00M NaClO4, the sorption increased with increased pcH to a maximum between pcH 8-8.5, then decreased as the pcH increased. The kinetics of NpO2+ sorption on hydroxyapatite followed Lagergren first order kinetics. The temperature dependence of sorption was small in the range of 273-283 K, but increased more sharply at higher temperatures of 298-333 K. The heat of sorption of NPO2+ was endothermic and the free energy values were exothermic indicating large, positive entropy. The activation energy for the sorption process was calculated to be 29.52 +/- 1.2 kJ/mole. The effect of calcium and phosphate on NPO2+ sorption was studied as a function of concentration and pcH. C1 Florida State Univ, Dept Chem & Biochem, Tallahassee, FL 32306 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Choppin, GR (reprint author), Florida State Univ, Dept Chem & Biochem, Tallahassee, FL 32306 USA. EM choppin@chem.fsu.edu NR 34 TC 6 Z9 7 U1 0 U2 11 PU OLDENBOURG VERLAG PI MUNICH PA LEKTORAT MINT, POSTFACH 80 13 60, D-81613 MUNICH, GERMANY SN 0033-8230 J9 RADIOCHIM ACTA JI Radiochim. Acta PY 2006 VL 94 IS 9-11 BP 645 EP 649 DI 10.1524/ract.2006.94.9.645 PG 5 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 149FY UT WOS:000245133700024 ER PT J AU Ozaki, T Kimura, T Ohnuki, T Francis, AJ AF Ozaki, T. Kimura, T. Ohnuki, T. Francis, A. J. TI Effects of ionic strength on the coordination of Eu(III) and Cm(III) to a gram-negative bacterium, Paracoccus denitrificans SO RADIOCHIMICA ACTA LA English DT Article; Proceedings Paper CT 10th International Conference on Chemistry and Migration of Actinides and Fission Products CY SEP 18-23, 2005 CL Avignon, FRANCE SP Commissariat Energie Atom, CNRS DE ionic strength; Paracoccus denitrificans; Europium(III); Curium(III); coordination environment; time-resolved laser-induced fluorescence spectroscopy (TRLFS) ID INDUCED FLUORESCENCE SPECTROSCOPY; HALOMONAS-ELONGATA; CHLORELLA-VULGARIS; CELL-WALL; EUROPIUM(III); CURIUM(III); BIOREMEDIATION; MICROORGANISMS; RADIONUCLIDES; ADSORPTION AB We studied the effect of ionic strength on the interactions of Europium(III) and Curium(III) with a Gramnegative bacterium Paracoccus denitrificans. Bacterial cells grown in 0.5-, 3.5-, and 5.0% NaCl were used in adsorption experiments and laser experiments that were performed at the same ionic strengths as those in the original growth media. The distribution ratio (log K-d) for Eu(III) and Cm(III) was determined at pHs 3-5. To elucidate the coordination environment of Eu(III) adsorbed on P denitrificans, we estimated the number of water molecules in the inner sphere and strength of the ligand field by time-resolved laser-induced fluorescence spectroscopy (TRLFS) at pHs 4-6. The log & of Eu(III) and Cm(III) increased with an increase of pH at all ionic strengths because there was less competition for ligands in cells with H+ at higher pHs, wherein less H+ was present in solution: cation adsorption generally occurs through an exchange with H+ on the functional groups of coordination sites. No significant differences were observed in the log K-d of Eu(III) and Cm(III) at each pH in 0.5-, 3.5-, and 5.0% NaCl solutions, though competition for figands with Na+ would be expected to increase at higher NaCl concentrations. The log Kd of Eu(III) was almost equivalent to that of Cm(III) under all the experimental conditions. TRLFS showed that the coordination environments of Eu(III) did not differ from each other at 0.5-, 3.5-, and 5.0% NaCl at pHs 4-6. TRLFS also showed that the characteristic of the coordination environment of Eu(111) on P. denitrificans was similar to that on a halophile, Nesterenkonia halobia, while it significantly differed from that on a non-halophile, Pseudomonas putida. These findings indicate that the number of coordination sites for Eu(111) on P denitrificans, whose cell surface may have similar structures to that of halophiles, increased with increasing ionic strength, though their structure remained unchanged. C1 Japan Atom Energy Agcy, Adv Sci Res Ctr, Tokai, Ibaraki 3191195, Japan. Japan Atom Energy Agcy, Nucl Sci & Engn Directorate, Tokai, Ibaraki 3191195, Japan. Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA. RP Ozaki, T (reprint author), Japan Atom Energy Agcy, Adv Sci Res Ctr, Tokai, Ibaraki 3191195, Japan. EM ozaki.takuo@jaea.go.jp NR 27 TC 8 Z9 8 U1 2 U2 10 PU OLDENBOURG VERLAG PI MUNICH PA LEKTORAT MINT, POSTFACH 80 13 60, D-81613 MUNICH, GERMANY SN 0033-8230 J9 RADIOCHIM ACTA JI Radiochim. Acta PY 2006 VL 94 IS 9-11 BP 715 EP 721 DI 10.1524/ract.2006.94.9.715 PG 7 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 149FY UT WOS:000245133700034 ER PT J AU Francis, AJ Dodge, CJ Gillow, JB AF Francis, A. J. Dodge, C. J. Gillow, J. B. TI Biotransformation of plutonium complexed with citric acid SO RADIOCHIMICA ACTA LA English DT Article; Proceedings Paper CT 10th International Conference on Chemistry and Migration of Actinides and Fission Products CY SEP 18-23, 2005 CL Avignon, FRANCE SP Commissariat Energie Atom, CNRS DE plutonium; citric acid; speciation; biodegradation; ionic strength ID CARBONATE COMPLEXES; TRENCH LEACHATES; SOIL; SIDEROPHORES; WATER; SITE; NP AB The presence of organic ligands in radioactive wastes is a major concern because of their potential for increasing the transport of radionuclides from disposal sites. Biotransformation of radionuclides complexed with organic ligands should precipitate the radionuclides and retard their migration. We investigated the biotransformation of Pu(IV) (10(-8) to 10(-5) M), by Pseudomonas fluorescens in the presence of excess citric acid. Analysis of Pu-242-citrate by electrospray ionization-mass spectrometry (ESI-MS) indicated the presence of biligand PU-Cit(2) as the predominant complex. XANES and EXAFS analyses showed that Pu was in the +4 oxidation state and associated with citric acid as a mononuclear complex. Citric acid was metabolized by P. fluorescens at a rate of 4.9 mu M/h, but in the presence of 10(-8) and 10(-6) M Pu, this rate decreased to 4.0 and 3.8 mu M/h, respectively. An increase in the ionic strength of the medium from 0.18 M to 0.9 M lowered citrate metabolism by similar to 65%. Pu added to the growth medium in the absence of bacteria remained as Pu(IV) in solution as a complex with citric acid. However, solvent extraction by thenoyltrifluoroacetone (TTA) and microfiltration (0.03 mu m) of the medium containing bacteria after citrate biodegradation revealed the presence of polymeric Pu. The extent of formation of the Pu polymer depended on the Pu:citrate ratio, the extent of citrate metabolism, and the ionic strength of the medium. C1 Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA. RP Francis, AJ (reprint author), Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA. EM Francis1@bnl.gov NR 35 TC 17 Z9 18 U1 1 U2 11 PU OLDENBOURG VERLAG PI MUNICH PA LEKTORAT MINT, POSTFACH 80 13 60, D-81613 MUNICH, GERMANY SN 0033-8230 J9 RADIOCHIM ACTA JI Radiochim. Acta PY 2006 VL 94 IS 9-11 BP 731 EP 737 DI 10.1524/ract.2006.94.9.731 PG 7 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA 149FY UT WOS:000245133700036 ER PT J AU Washington-Allen, RA West, NE Ramsey, RD Efroymson, RA AF Washington-Allen, RA West, NE Ramsey, RD Efroymson, RA TI A protocol for retrospective remote sensing-based ecological monitoring of rangelands SO RANGELAND ECOLOGY & MANAGEMENT LA English DT Article DE catastrophe theory; ecological indicators; land degradation; Landsat; trend ID CATASTROPHIC SHIFTS; VEGETATION INDEX; EL-NINO; MANAGEMENT; ECOSYSTEMS; DYNAMICS; LANDSAT; DEGRADATION; PARAMETERS; LANDSCAPE AB The degree of rangeland degradation in the United States is unknown due to the failure of traditional field-based monitoring to capture the range of variability of ecological indicators and disturbances, including climatic effects and land use practices, at regional to national spatial scales, and temporal scales of decades. Here, a protocol is presented for retrospective monitoring and assessment of rangeland degradation using historical time series of remote sensing data and catastrophe theory as an ecological framework to account for both gradual and rapid changes of state. This protocol 1) justifies the use of time-series satellite imagery in terms of the spatial and temporal scale of data collection; 2) briefly explains how to acquire, process, and transform the data into ecological indicators; 3) discusses the use of time-series analysis as the appropriate procedure for detecting significant change; and 4) explains what reference conditions are appropriate. Landsat data have been collected and archived since 1972, and include complete coverage of US rangelands. Characteristics of land degradation can be retrospectively measured for a nearly 33-year trend using surrogate remote sensing-based indicators that correlate with changes in life-form composition (time series of thematic maps), declines in vegetation productivity (vegetation indices), accelerated soil erosion (soil indices), declines in soil quality (piospheric analysis), and changes in landscape configuration (time series of thematic maps). Aspects of 2 retrospective studies are presented as examples of application of the protocol to considerations of the land use impacts from military training and testing and ranching activities on rangelands. C1 Univ Virginia, Dept Environm Sci, Charlottesville, VA 22904 USA. Univ Tennessee, Dept Geog, Knoxville, TN 37996 USA. Utah State Univ, Dept Forest Range & Wildlife Sci, Logan, UT 84322 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Washington-Allen, RA (reprint author), Univ Virginia, Dept Environm Sci, Clark Hall,291 McCormick Rd, Charlottesville, VA 22904 USA. EM washingtonra@mac.com RI Ramsey, R. Douglas/D-3504-2009 NR 62 TC 49 Z9 50 U1 3 U2 24 PU SOC RANGE MANAGEMENT PI LAKEWOOD PA 445 UNION BLVD, STE 230, LAKEWOOD, CO 80228-1259 USA SN 1550-7424 J9 RANGELAND ECOL MANAG JI Rangel. Ecol. Manag. PD JAN PY 2006 VL 59 IS 1 BP 19 EP 29 DI 10.2111/04-116R2.1 PG 11 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA 006NV UT WOS:000234905100003 ER PT J AU Tompkins, EM Farmer, PB Lamb, JH Jukes, R Dingley, K Ubick, E Turteltaub, KW Martin, EA Brown, K AF Tompkins, EM Farmer, PB Lamb, JH Jukes, R Dingley, K Ubick, E Turteltaub, KW Martin, EA Brown, K TI A novel C-14-postlabeling assay using accelerator mass spectrometry for the detection of O-6-methyldeoxy-guanosine adducts SO RAPID COMMUNICATIONS IN MASS SPECTROMETRY LA English DT Article ID DNA-ADDUCTS; LIQUID-CHROMATOGRAPHY; METHYLATING AGENTS; O-6-METHYLGUANINE; O(6)-METHYLGUANINE; QUANTITATION; REPAIR; CELLS; CARCINOGENESIS; MECHANISM AB Accelerator mass spectrometry (AMS) is currently one of the most sensitive methods available for the trace detection of DNA adducts and is particularly valuable for measuring adducts in humans or animal models. However, the standard approach requires administration of a radiolabeled compound. As an alternative, we have developed a preliminary C-14-postlabeling assay for detection of the highly mutagenic O-6-methyldeoxyguanosine (O-6-MedG), by AMS. Procedures were developed for derivatising O-6-MedG using unlabeled acetic anhydride. Using conventional liquid chromatography/mass spectrometry (LC/MS) analysis, the limit of detection (LOD) for the major product, triacetylated O-6-MedG, was 10 fmol. On reaction of O-6-MedG with C-14-acetic anhydride, using a specially designed enclosed system, the predominant product was C-14-di-acetyl O-6-MedG. This change in reaction profile was due to a modification of the reaction procedure, introduced as a necessary safety precaution. The LOD for C-14-di-acetyl O-6-MedG by AMS was determined as 79 amol, similar to 18 000-fold lower than that achievable by liquid scintillation counting (LSC). Although the assay has so far only been carried out with labeled standards, the degree of sensitivity obtained illustrates the potential of this assay for measuring O-6-MedG levels in humans. Copyright (c) 2006 John Wiley & Sons, Ltd. C1 Univ Leicester, Dept Canc Studies & Mol Med, Canc Biomarkers & Prevent Grp, Bioctr, Leicester LE1 7RH, Leics, England. Univ Leicester, MRC, Toxicol Unit, Leicester LE1 9HN, Leics, England. Lawrence Livermore Natl Lab, Biosci Div, Livermore, CA 94551 USA. RP Brown, K (reprint author), Univ Leicester, Dept Canc Studies & Mol Med, Canc Biomarkers & Prevent Grp, Bioctr, Univ Rd, Leicester LE1 7RH, Leics, England. EM kb20@le.ac.uk FU Medical Research Council [G0100873] NR 34 TC 10 Z9 10 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0951-4198 J9 RAPID COMMUN MASS SP JI Rapid Commun. Mass Spectrom. PY 2006 VL 20 IS 5 BP 883 EP 891 DI 10.1002/rcm.2370 PG 9 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA 018HM UT WOS:000235755000023 PM 16470516 ER PT J AU Van Berkel, GJ Ford, MJ Doktycz, MJ Kennel, SJ AF Van Berkel, GJ Ford, MJ Doktycz, MJ Kennel, SJ TI Evaluation of a surface-sampling probe electrospray mass spectrometry system for the analysis of surface-deposited and affinity-captured proteins SO RAPID COMMUNICATIONS IN MASS SPECTROMETRY LA English DT Article ID TOP-DOWN; IONIZATION; PROTEOMICS; QUANTITATION; SEPARATIONS; SUPPORTS; DEVICE AB A combined self-aspirating electrospray emitter/surfacing-sampling probe coupled with an ion trap mass spectrometer was used to sample and mass analyze proteins from surfaces. The sampling probe mass spectrometer system was used to sample and detect lysozyme that had been deposited onto a glass slide using a piezoelectric spotter or murine gamma-interferon affinity captured on a glass slide using surface-immobilized anti-gamma-interferon antibody. The detection level for surface deposited lysozyme (spot size <= 200 mu m) was approximately 1.0 fmol (similar to 100 fmol/mm(2)) as determined from the ability to measure accurately the protein molecular mass from the mass spectrum acquired by sampling the deposit. These detection limits may be sufficient for certain applications in which protein fractions from a separation method are collected onto a surface. Radiolabeled proteins were used to quantify the surface density of immobilized antibody and the efficiency of capture of the gamma-interferon on glass and higher surface area ceramic supports. The capture density of gamma-interferon at surface saturation ranged from about 23 to 50 fmol/mm(2) depending on the capture surface. Nonetheless, mass spectrometric detection of affinity capture protein was successful in some cases, but the results were not reproducible. Thus, improvement of the sampling system, ionization efficiency and/or capture density will be necessary for practical sampling of affinity-captured proteins. The means to accomplish improved sampling system detection limits and to increase the absolute amounts of protein captured per unit area are discussed. Published in 2006 by John Wiley & Sons, Ltd. C1 Oak Ridge Natl Lab, Chem Sci Div, Organ & Biol Mass Spectr, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Life Sci Div, Biol & Nanoscale Syst Grp, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Life Sci Div, Mammalian Genet Grp, Oak Ridge, TN 37831 USA. RP Van Berkel, GJ (reprint author), Oak Ridge Natl Lab, Chem Sci Div, Organ & Biol Mass Spectr, Oak Ridge, TN 37831 USA. EM vanberkelgj@ornl.gov RI Doktycz, Mitchel/A-7499-2011 OI Doktycz, Mitchel/0000-0003-4856-8343 NR 25 TC 23 Z9 23 U1 1 U2 7 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0951-4198 J9 RAPID COMMUN MASS SP JI Rapid Commun. Mass Spectrom. PY 2006 VL 20 IS 7 BP 1144 EP 1152 DI 10.1002/rcm.2438 PG 9 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA 030NZ UT WOS:000236642700013 PM 16521171 ER PT J AU Wilkes, JG Buzatu, DA Dare, DJ Dragan, YP Chiarelli, MP Holland, RD Beaudoin, M Heinze, TM Nayak, R Shvartsburg, AA AF Wilkes, JG Buzatu, DA Dare, DJ Dragan, YP Chiarelli, MP Holland, RD Beaudoin, M Heinze, TM Nayak, R Shvartsburg, AA TI Improved cell typing by charge-state deconvolution of matrix-assisted laser desorption/ionization mass spectra SO RAPID COMMUNICATIONS IN MASS SPECTROMETRY LA English DT Article ID IONIC LIQUID MATRICES; MALDI-TOF; DESORPTION IONIZATION; QUANTITATIVE-ANALYSIS; SAMPLE PREPARATION; SECONDARY-ION; WHOLE CELLS; SPECTROMETRY; TIME; QUANTIFICATION AB Robust, specific, and rapid identification of toxic strains of bacteria and viruses, to guide the mitigation of their adverse health effects and optimum implementation of other response actions, remains a major analytical challenge. This need has driven the development of methods for classification of microorganisms using mass spectrometry, particularly matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), that allows high-throughput analyses with minimum sample preparation. We describe a novel approach to cell typing based on pattern recognition of MALDI mass spectra, which involves charge-state deconvolution in conjunction with a new correlation analysis procedure. The method is applicable to both prokaryotic and eukaryotic cells. Charge-state deconvolution improves the quantitative reproducibility of spectra because multiply charged ions resulting from the same biomarker attaching a different number of protons are recognized and their abundances are combined. This allows a clearer distinction of bacterial strains or of cancerous and normal liver cells. Improved class distinction provided by charge-state deconvolution was demonstrated by cluster spacing on canonical variate score charts and by correlation analyses. Deconvolution may enhance detection of early disease state or therapy progress markers in various tissues analyzed by MALDI-MS. Published in 2006 by John Wiley & Sons, Ltd. C1 US FDA, Natl Ctr Toxicol Res, Div Syst Toxicol, Jefferson, AR 72079 USA. Manchester Metropolitan Univ, Res Dev Unit, Manchester M15 6BH, Lancs, England. Loyola Univ, Dept Chem, Chicago, IL 60626 USA. ZTech Corp, Jefferson, AR 72079 USA. Pacific NW Natl Lab, Div Biol Sci, Richland, WA 99352 USA. RP Wilkes, JG (reprint author), US FDA, Natl Ctr Toxicol Res, Div Syst Toxicol, 3900 NCTR Rd, Jefferson, AR 72079 USA. EM jon.wilkes@fda.hhs.gov NR 64 TC 6 Z9 6 U1 0 U2 3 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0951-4198 J9 RAPID COMMUN MASS SP JI Rapid Commun. Mass Spectrom. PY 2006 VL 20 IS 10 BP 1595 EP 1603 DI 10.1002/rcm.2475 PG 9 WC Biochemical Research Methods; Chemistry, Analytical; Spectroscopy SC Biochemistry & Molecular Biology; Chemistry; Spectroscopy GA 046EN UT WOS:000237794300019 PM 16628570 ER PT J AU Palmer, JA Jokiel, B Nordquist, CD Kast, BA Atwood, CJ Grant, E Livingston, FJ Medina, F Wicker, RB AF Palmer, J. A. Jokiel, B. Nordquist, C. D. Kast, B. A. Atwood, C. J. Grant, E. Livingston, F. J. Medina, F. Wicker, R. B. TI Mesoscale RF relay enabled by integrated rapid manufacturing SO RAPID PROTOTYPING JOURNAL LA English DT Article DE assembly; relays; rapid prototypes ID FABRICATION; STEREOLITHOGRAPHY AB Purpose - This paper presents a novel mesoscale RF (mRF) relay that integrates advanced high resolution stereolithography (SL) and micro wire electro discharge machining (mu EDM) technologies. Methods and infrastructure for reliable batch assembly of electromechanical actuators and structural parts less than 5 mm(3) in volume are described. Switches made using these techniques are expected to have greater power handling capability relative to current micro RF relay products. Design/methodology/approach - The conjecture is that the integration of SL and similar rapid additive manufacturing with other mesofabrication technologies can yield innovative miniature products with novel capabilities. A series of mRF prototypes consisting of a contact mechanism and actuator with return spring were fabricated assembled, inspected, and characterized for electromechanical performance. Characterization results led to specific conclusions regarding capabilities of the mRF product, and the integrated manufacturing technique. Findings - The microassembly apparatus and epoxy-based fastening system led to durable prototypes within 4 h (excluding a 16-24 h cure cycle). Relay stroke ranged from 560 to 1,650 mu m indicating a relative assembly accuracy of 90 percent. Prototypes demonstrated insertion loss of 1.3 dB at 100 MHz and isolation of better than 30 dB through 300 MHz. Research limitations/implications - Results indicated that fully functional and robust mesoscale relays are possible using integrated manufacturing with SL. However, prototypes exhibited high contact resistance and lacked assembly precision in the context of contact mechanism stroke. Opportunities exist to reduce contact resistance and switching time. Practical implications - The research provides a practical new product application for integrated mesoscale rapid manufacturing. Originality/value - This work represents one of the first examples of a mesoscale relay rapidly manufactured with a combination of mu EDM and SL components. C1 Univ New Mexico, Sandia Natl Labs, Albuquerque, NM 87131 USA. N Carolina State Univ, Dept Elect & Comp Engn, Raleigh, NC 27695 USA. Univ Texas, WM Keck Border Biomed Mfg Engn Lab, El Paso, TX USA. RP Palmer, JA (reprint author), Univ New Mexico, Sandia Natl Labs, Albuquerque, NM 87131 USA. EM japalme@sandia.gov NR 25 TC 14 Z9 14 U1 1 U2 9 PU EMERALD GROUP PUBLISHING LIMITED PI BRADFORD PA 60/62 TOLLER LANE, BRADFORD BD8 9BY, W YORKSHIRE, ENGLAND SN 1355-2546 J9 RAPID PROTOTYPING J JI Rapid Prototyping J. PY 2006 VL 12 IS 3 BP 148 EP 155 DI 10.1108/13552540610670726 PG 8 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 063LB UT WOS:000239018600006 ER PT J AU Crane, NB Wilkes, J Sachs, E Allen, SM AF Crane, Nathan B. Wilkes, J. Sachs, E. Allen, Samuel M. TI Improving accuracy of powder-based SFF processes by metal deposition from a nanoparticle dispersion SO RAPID PROTOTYPING JOURNAL LA English DT Article; Proceedings Paper CT 2005 Solid Freeform Fabrication Symposium (SFFS) CY AUG 06-08, 2005 CL Austin, TX DE sintering; metals; creep ID IMPREGNATION; CATALYSTS AB Purpose - Solid freeform fabrication processes such as three-dimensional printing (3DP) and selective laser sintering (SLS) produce porous parts. Metal parts produced by these processes must be densified by sintering or infiltration to achieve maximum material performance. New steel infiltration methods can produce parts of standard alloy compositions with properties comparable to wrought materials. However, the infiltration process introduces dimensional errors due to both shrinkage and creep - particularly at the high temperatures required for steel infiltration. Aims to develop post-processing method to reduce creep and shrinkage of porous metal skeletons. Design/methodology/approach - The proposed process treats porous metal parts with a nanoparticle suspension that strengthens the bonds between particles to reduce creep and sintering shrinkage during infiltration. The process is tested by comparing the deflection and shrinkage of treated and untreated cantilevers heated to infiltration temperatures. The method is demonstrated with an iron nanoparticles suspension applied to parts made of 410 SS powder. Findings - This process reduced creep by up to 95 percent and shrinkage by 50 percent. The best results were obtained using multiple applications of the nanoparticles dried under a magnetic field. Carbon deposited with the iron is shown to provide substantial benefit, but the iron is critical to establish strong bonds at low temperatures for minimal creep. Research limitations/implications - This work shows that dimensional stability of porous metal skeletons during infiltration processes can be significantly improved by treatment with nanoparticles. The increased dimensional stability afforded by this technique can combine the excellent properties of homogenous infiltration with substantially improved part accuracy and open up new applications for this manufacturing technology. Originality/value - The work shows how solid freeform fabrication processes can be improved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. MIT, Dept Mech Engn, Cambridge, MA 02139 USA. MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. RP Crane, NB (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM nbcrane@eng.usf.edu OI Crane, Nathan/0000-0002-9170-346X NR 15 TC 8 Z9 9 U1 0 U2 16 PU EMERALD GROUP PUBLISHING LIMITED PI BINGLEY PA HOWARD HOUSE, WAGON LANE, BINGLEY BD16 1WA, W YORKSHIRE, ENGLAND SN 1355-2546 J9 RAPID PROTOTYPING J JI Rapid Prototyping J. PY 2006 VL 12 IS 5 BP 266 EP 274 DI 10.1108/13552540610707022 PG 9 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 112JE UT WOS:000242521000004 ER PT B AU Nguyen, TB Pai, MA AF Nguyen, TB Pai, MA BE Savulescu, SC TI Sensitivity analysis of dynamic stability indicators in power systems SO REAL-TIME STABILITY IN POWER SYSTEMS: TECHNIQUES FOR EARLY DETECTION OF THE RISK OF BLACKOUT SE Power Electronics and Power Systems LA English DT Proceedings Paper CT IEEE Power Systems Conference and Exposition CY OCT 13, 2004 CL New York, NY SP IEEE DE dynamic security assessment; trajectory sensitivity analysis; mode of instability; preventive rescheduling; critical parameter computation; relay margin; principal singular surface ID TRANSIENT STABILITY; TRAJECTORY SENSITIVITIES; SECURITY; FLOW AB Real time stability evaluation and preventive scheduling in power systems offer many challenges in a stressed power system. Through fast simulation of contingencies in real time, it is possible to extract suitable information from the data and develop reliable metrics or indices to evaluate proximity of the system to an unstable condition. In this chapter we review the recent applications of the trajectory sensitivity analysis (TSA) technique in developing such indicators. Trajectory sensitivities can be used to compute critical parameters such as clearing time of circuit breakers, tie line flow, etc. in a power system by developing suitable norms for ease of interpretation. Alternatively, it can be used along with the notion of principal singular surfaces (PSS) to detect mode of instability (MOI). The TSA technique has the advantage that model complexity is not a limitation, and the sensitivities can be computed numerically. Suitable metrics are developed from these sensitivities. In addition to computing critical parameters, the TSA technique can be extended to do preventive rescheduling. A brief discussion of other applications of TSA is included as well as future areas of research. C1 Pacific NW Natl Lab, 902 Battelle Blvd,POB 999,MS K5-20, Richland, WA 99354 USA. RP Pacific NW Natl Lab, 902 Battelle Blvd,POB 999,MS K5-20, Richland, WA 99354 USA. NR 46 TC 4 Z9 4 U1 1 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES BN 0-387-25626-1 J9 POWER ELECTRON POWER PY 2006 BP 233 EP + PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BDG08 UT WOS:000233335300009 ER PT S AU Xanthopoulos, E Becker, RH deVries, WH White, RL AF Xanthopoulos, E. Becker, R. H. deVries, W. H. White, R. L. BE Solomos, NH TI Improved constraints on the cosmological parameters using the VLA FIRST survey SO RECENT ADVANCES IN ASTRONOMY AND ASTROPHYSICS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 7th International Conference of the Hellenic-Astronomical-Society CY SEP 08-11, 2006 CL Lixourion, GREECE SP Municipal Lixourion Pallis, Alexander S Onassis Fdn, Hellen Minist Tourism, Hellen Astron Soc, EUDOXOS Natl Observ Educ, Prefecture Kefallinia & Ithaki, Hellen Natl Comm Astron, Hellen Naval Acad DE cosmological parameters; radio galaxies ID RADIO STRUCTURE; QUASARS AB Using the final version of the VLA FIRST survey (Becker et al. 2003), the optical Sloan Digital Sky Survey Data Release 3 (DR3) quasar list and a series of carefully selected criteria, we have defined the largest homogeneous population of double-lobed sources. With the precise sample definition, the increased depth and sensitivity of the survey data, the large size of the dataset, and our self-consistent method of analysis, which addresses many of the problems associated with previous work in the area, we are able to: a) explore the correlations between the intrinsic properties of the double-lobed radio sources (the results are also confirmed by a non-parametric analysis) and study their evolution, b) place more interesting and tighter constraints on the cosmological parameters, distinguish among the different cosmology models, and determine the impact of the angular sizeredshift studies in cosmology, c) further our understanding of the behavior of the intergalactic medium (IGM) density as a function of redshift and shed more light to the quasar-radio galaxy unification issue. C1 [Xanthopoulos, E.; Becker, R. H.; deVries, W. H.] Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. [Xanthopoulos, E.; Becker, R. H.; deVries, W. H.] Lawrence Livermore Natl Lab, IGPP, Livermore, CA 94550 USA. [White, R. L.] Space Telescope Sci Inst, Baltimore, MD 21218 USA. RP Xanthopoulos, E (reprint author), Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. RI White, Richard/A-8143-2012 FU U.S. Department of Energy; National Nuclear Security Administration; University of California; Lawrence Livermore National Laboratory [W-7405-Eng-48]; National Science Foundation [AST 00-98355] FX EXs work was performed under the auspices of the U.S. Department of Energy, National Nuclear Security Administration by the University of California, Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48 and she also acknowledges support from the National Science Foundation (grant AST 00-98355). NR 6 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 0-7354-0343-0 J9 AIP CONF PROC PY 2006 VL 848 BP 492 EP + PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BFE04 UT WOS:000241381900066 ER PT S AU Xanthopoulos, E Thomasson, P Muxlow, TWB Garrington, ST AF Xanthopoulos, E. Thomasson, P. Muxlow, T. W. B. Garrington, S. T. BE Solomos, NH TI Jet-induced star formation in Seyfert galaxies unveiled through radio-UV correlations SO RECENT ADVANCES IN ASTRONOMY AND ASTROPHYSICS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 7th International Conference of the Hellenic-Astronomical-Society CY SEP 08-11, 2006 CL Lixourion, GREECE SP Municipal Lixourion Pallis, Alexander S Onassis Fdn, Hellen Minist Tourism, Hellen Astron Soc, EUDOXOS Natl Observ Educ, Prefecture Kefallinia & Ithaki, Hellen Natl Comm Astron, Hellen Naval Acad DE group of galaxies; radio observations; Stephan's Quintet; NGC 7319 ID STEPHANS-QUINTET; MOLECULAR GAS; EMISSION AB During the course of MERLIN L-band observations of the compact galaxy group, Stephan's Quintet, we found that the Seyfert 2 galaxy, NGC 7319, the brightest member of the compact group, has a triple radio structure typical of many extra-galactic radio sources which have a flat spectrum core and two steep spectrum lobes with hot spots. The two lobes are asymmetrically distributed on opposite sides of the core along the minor axis of the galaxy. Ultraviolet emission revealed in a high resolution HRC/ACS HST image is strongly aligned with the radio plasma and we interpret the intense star formation in the core and north lobe as an event induced by the collision of the north radio jet with over-dense ambient material. In addition, a re-mapping of archive VLA L-band observations reveals more extended emission along the major axis of the galaxy which is aligned with the optical axis. Images formed from the combined MERLIN and archive VLA data reveal more detailed structure of the two lobes and hot spots. NGC 7319 is the first example of jet induced star formation in a Seyfert galaxy unveiled through radio/UV correlations. Using high resolution HST ACS/HRC near-UV (F330W) images, and their corresponding published radio maps, we have identified a number of other possible jet-induced star formation Seyfert galaxies candidates. C1 [Xanthopoulos, E.] Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. [Xanthopoulos, E.] Lawrence Livermore Natl Lab, IGPP, Livermore, CA 94550 USA. [Thomasson, P.; Muxlow, T. W. B.; Garrington, S. T.] Univ Manchester, Jodrell Bank Observat, Macclesfield SK11 9DL, Cheshire, England. RP Xanthopoulos, E (reprint author), Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. NR 12 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 0-7354-0343-0 J9 AIP CONF PROC PY 2006 VL 848 BP 587 EP + PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BFE04 UT WOS:000241381900077 ER PT S AU Xanthopoulos, E Thean, AH Pedlar, A Richards, AMS AF Xanthopoulos, E. Thean, A. H. Pedlar, A. Richards, A. M. S. BE Solomos, NH TI Linear radio structures in selected Seyfert and LINER galaxies SO RECENT ADVANCES IN ASTRONOMY AND ASTROPHYSICS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 7th International Conference of the Hellenic-Astronomical-Society CY SEP 08-11, 2006 CL Lixourion, GREECE SP Municipal Lixourion Pallis, Alexander S Onassis Fdn, Hellen Minist Tourism, Hellen Astron Soc, EUDOXOS Natl Observ Educ, Prefecture Kefallinia & Ithaki, Hellen Natl Comm Astron, Hellen Naval Acad DE Seyfert and LINER galaxies; radio observations; jets AB High resolution MERLIN 5 GHz observations (0."04) of 7 Seyfert galaxies, selected as the ones previously showing evidence of collimated ejection, have been compared with high resolution archive HST data. The radio maps reveal rich structures in all the galaxies. NGC 2639 and TXFS 2226-184 have multiple knot parsec-scale extended structures, Mrk 1034, Mrk 1210, NGC 4922C and NGC 5506 reveal one-sided jets, while IC 1481 exhibits a jet-like extension. The close correlation between the radio-emitting relativistic plasma and the ionized gas in the inner regions of these galaxies allows us to study in detail the physics close to the center of low luminosity AGN. C1 [Xanthopoulos, E.] Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. [Xanthopoulos, E.] Lawrence Livermore Natl Lab, IGPP, Livermore, CA 94550 USA. [Thean, A. H.; Pedlar, A.; Richards, A. M. S.] Univ Manchester, Jodrell Bank Observat, Macclesfield SK11 9DL, Cheshire, England. RP Xanthopoulos, E (reprint author), Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. OI Richards, Anita/0000-0002-3880-2450 NR 3 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 0-7354-0343-0 J9 AIP CONF PROC PY 2006 VL 848 BP 592 EP + PG 2 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BFE04 UT WOS:000241381900078 ER PT S AU Muelder, C Ma, KL Bartoletti, T AF Muelder, C Ma, KL Bartoletti, T BE Valdes, A Zamboni, D TI Interactive visualization for network and port scan detection SO RECENT ADVANCES IN INTRUSION DETECTION SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 8th International Symposium on Recent Advances in Intrusion Detection CY SEP 07-09, 2005 CL Seattle, WA DE network security; information visualization; intrusion detection; user interfaces; port scans; network scans AB Many times, network intrusion attempts begin with either a network scan, where a connection is attempted to every possible destination in a network, or a port scan, where a connection is attempted to each port on a given destination. Being able to detect such scans can help identify a more dangerous threat to a network. Several techniques exist to automatically detect scans, but these are mostly dependant on some threshold that an attacker could possibly avoid crossing. This paper presents a means to use visualization to detect scans interactively. C1 Univ Calif Davis, Davis, CA 95616 USA. Lawrence Livermore Natl Lab, Livermore, CA USA. RP Muelder, C (reprint author), Univ Calif Davis, Davis, CA 95616 USA. NR 19 TC 11 Z9 11 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-31778-3 J9 LECT NOTES COMPUT SC PY 2006 VL 3858 BP 265 EP 283 PG 19 WC Computer Science, Information Systems; Computer Science, Theory & Methods SC Computer Science GA BDY32 UT WOS:000236107800014 ER PT S AU Gropp, W Thakur, R AF Gropp, William Thakur, Rajeev BE Mohr, B Traff, JL Worringen, J Dongarra, J TI Issues in developing a thread-safe MPI implementation SO RECENT ADVANCES IN PARALLEL VIRTUAL MACHINE AND MESSAGE PASSING INTERFACE SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 13th European Parallel-Virtual-Machine-and-Message-Passing-Interface-Users-Group Meeting (PVM/MPI) CY SEP 17-20, 2006 CL Bonn, GERMANY SP Parallel Virtual Machine & Message Passing Interface Users Grp, Etnus, IBM, intel, NEC, Dolphin Interconnect Solut, Hewlett Packard, Microsoft, Sun, QLogic AB The MPI-2 Standard has carefully specified the interaction between MPI and user-created threads, with the goal of enabling users to write multithreaded programs while also enabling MPI implementations to deliver high performance. In this paper, we describe and analyze what the MPI Standard says about thread safety and what it implies for an implementation. We classify the MPI functions based on their thread-safety requirements and discuss several issues to consider when implementing thread safety in MPI. We use the example of generating new context ids (required for creating new communicators) to demonstrate how a simple solution for the single-threaded case cannot be used when there are multiple threads and how a naive thread-safe algorithm can be expensive. We then present an algorithm for generating context ids that works efficiently in both single-threaded and multithreaded cases. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Gropp, W (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM gropp@mcs.anl.gov; thakur@mcs.anl.gov RI Dongarra, Jack/E-3987-2014; OI Gropp, William/0000-0003-2905-3029 NR 8 TC 13 Z9 13 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-39110-X J9 LECT NOTES COMPUT SC PY 2006 VL 4192 BP 12 EP 21 PG 10 WC Computer Science, Theory & Methods SC Computer Science GA BFF20 UT WOS:000241557200001 ER PT S AU Pervez, S Gopalakrishnan, G Kirby, RM Thakur, R Gropp, W AF Pervez, Salman Gopalakrishnan, Ganesh Kirby, Robert M. Thakur, Rajeev Gropp, William BE Mohr, B Traff, JL Worringen, J Dongarra, J TI Formal verification of programs that use MPI one-sided communication SO RECENT ADVANCES IN PARALLEL VIRTUAL MACHINE AND MESSAGE PASSING INTERFACE SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 13th European Parallel-Virtual-Machine-and-Message-Passing-Interface-Users-Group Meeting (PVM/MPI) CY SEP 17-20, 2006 CL Bonn, GERMANY SP Parallel Virtual Machine & Message Passing Interface Users Grp, Etnus, IBM, intel, NEC, Dolphin Interconnect Solut, Hewlett Packard, Microsoft, Sun, QLogic AB We used formal-verification methods based on model checking to analyze the correctness properties of one existing and two new distributed-locking algorithms implemented by using MPI's one-sided communication. Model checking exposed an overlooked correctness issue with the first algorithm, which had been developed by relying only on manual reasoning. Model checking helped confirm the basic correctness properties of the two new algorithms, while also identifying the remaining problems in them. Our experience is that MPI-based programming, especially the tricky and relatively poorly understood one-sided communication features, stand to gain immensely from model checking. Considering that many other areas of concurrent hardware and software design now routinely employ model checking, our experience confirms that the MPI community can benefit greatly from the use of formal verification. C1 Univ Utah, Sch Comp, Salt Lake City, UT 84112 USA. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Pervez, S (reprint author), Univ Utah, Sch Comp, Salt Lake City, UT 84112 USA. RI Dongarra, Jack/E-3987-2014; OI Gropp, William/0000-0003-2905-3029 NR 15 TC 9 Z9 9 U1 0 U2 2 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-39110-X J9 LECT NOTES COMPUT SC PY 2006 VL 4192 BP 30 EP 39 PG 10 WC Computer Science, Theory & Methods SC Computer Science GA BFF20 UT WOS:000241557200003 ER PT S AU Woodall, TS Shipman, GM Bosilca, G Graham, RL Maccabe, AB AF Woodall, Tim S. Shipman, Galen M. Bosilca, George Graham, Richard L. Maccabe, Arthur B. BE Mohr, B Traff, JL Worringen, J Dongarra, J TI High performance RDMA protocols in HPC SO RECENT ADVANCES IN PARALLEL VIRTUAL MACHINE AND MESSAGE PASSING INTERFACE SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 13th European Parallel-Virtual-Machine-and-Message-Passing-Interface-Users-Group Meeting (PVM/MPI) CY SEP 17-20, 2006 CL Bonn, GERMANY SP Parallel Virtual Machine & Message Passing Interface Users Grp, Etnus, IBM, intel, NEC, Dolphin Interconnect Solut, Hewlett Packard, Microsoft, Sun, QLogic AB Modern network communication libraries that leverage Remote Directory Memory Access (RDMA) and OS bypass protocols, such as Infiniband [2] and Myrinet [10] can offer significant performance advantages over conventional send/receive protocols. However, this performance often comes with hidden per buffer setup costs [4]. This paper describes a unique long-message MPI [9] library 'pipeline' protocol that addresses these constraints while avoiding some of the pitfalls of existing techniques. By using portable send/receive semantics to hide the cost of initializing the pipeline algorithm, and then effectively overlapping the cost of memory registration with RDMA operations, this protocol provides very good performance for any large-memory usage pattern. This approach avoids the use of non-portable memory hooks or keeping registered memory from being returned to the OS. Through this approach, bandwidth may be increased up to 67% when memory buffers are not effectively reused while providing superior performance in the effective bandwidth benchmark. Several user level protocols are explored using Open MPI's PML (Point to point messaging layer) and compared/contrasted to this 'pipeline' protocol. C1 Los Alamos Natl Lab, Adv Comp Lab, Los Alamos, NM 87545 USA. Univ Tennessee, Dept Comp Sci, Knoxville, TN 37996 USA. Univ New Mexico, Dept Comp Sci, Albuquerque, NM 87131 USA. RP Woodall, TS (reprint author), Los Alamos Natl Lab, Adv Comp Lab, Los Alamos, NM 87545 USA. EM twoodall@lanl.gov; gshipman@lanl.gov; bosilca@cs.utk.edu; rlgraham@lanl.gov; maccabe@cs.unm.edu NR 11 TC 8 Z9 8 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-39110-X J9 LECT NOTES COMPUT SC PY 2006 VL 4192 BP 76 EP 85 PG 10 WC Computer Science, Theory & Methods SC Computer Science GA BFF20 UT WOS:000241557200008 ER PT S AU Buntinas, D Mercier, G Gropp, W AF Buntinas, Darius Mercier, Guillaume Gropp, William BE Mohr, B Traff, JL Worringen, J Dongarra, J TI Implementation and shared-memory evaluation of MPICH2 over the nemesis communication subsystem SO RECENT ADVANCES IN PARALLEL VIRTUAL MACHINE AND MESSAGE PASSING INTERFACE SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 13th European Parallel-Virtual-Machine-and-Message-Passing-Interface-Users-Group Meeting (PVM/MPI) CY SEP 17-20, 2006 CL Bonn, GERMANY SP Parallel Virtual Machine & Message Passing Interface Users Grp, Etnus, IBM, intel, NEC, Dolphin Interconnect Solut, Hewlett Packard, Microsoft, Sun, QLogic AB This paper presents the implementation of MPICH2 over the Nemesis communication subsystem and the evaluation of its shared-memory performance. We describe design issues as well as some of the optimization techniques we employed. We conducted a performance evaluation over shared memory using microbenchmarks as well as application benchmarks. The evaluation shows that MPICH2 Nemesis has very low communication overhead, making it suitable for smaller-grained applications. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Buntinas, D (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM buntinas@mcs.anl.gov; mercierg@mcs.anl.gov; gropp@mcs.anl.gov RI Dongarra, Jack/E-3987-2014; OI Gropp, William/0000-0003-2905-3029 NR 11 TC 4 Z9 4 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-39110-X J9 LECT NOTES COMPUT SC PY 2006 VL 4192 BP 86 EP 95 PG 10 WC Computer Science, Theory & Methods SC Computer Science GA BFF20 UT WOS:000241557200009 ER PT S AU Gottbrath, C Barrett, B Gropp, B Lusk, ER Squyres, J AF Gottbrath, Christopher Barrett, Brian Gropp, Bill Lusk, Ewing Rusty Squyres, Jeff BE Mohr, B Traff, JL Worringen, J Dongarra, J TI An interface to support the identification of dynamic MPI 2 processes for scalable parallel debugging SO RECENT ADVANCES IN PARALLEL VIRTUAL MACHINE AND MESSAGE PASSING INTERFACE SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 13th European Parallel-Virtual-Machine-and-Message-Passing-Interface-Users-Group Meeting (PVM/MPI) CY SEP 17-20, 2006 CL Bonn, GERMANY SP Parallel Virtual Machine & Message Passing Interface Users Grp, Etnus, IBM, intel, NEC, Dolphin Interconnect Solut, Hewlett Packard, Microsoft, Sun, QLogic AB This paper proposes an interface that will allow MPI 2 dynamic programs - those using MPI SPAWN, CONNECT/ACCEPT, or JOIN - to provide information to parallel debuggers such as TotalView about the set of processes that constitute an individual application. The TotalView parallel debugger currently obtains information about the identity of processes directly from the MPI library using a widely accepted proctable interface. The existing interface does not support MPI 2 dynamic operations. The proposed interface supports MPI 2 dynamic operations, subset debugging, and helps the parallel debugger assign meaningful names to processes. C1 Etnus LLC, Natick, MA 01760 USA. Indiana Univ, Dept Comp Sci, Bloomington, IN 47405 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Cisco Syst Inc, San Jose, CA 95134 USA. RP Gottbrath, C (reprint author), Etnus LLC, 24 Prime Pk Way, Natick, MA 01760 USA. EM Chris.Gottbrath@etnus.com; brbarret@osl.iu.edu; gropp@mcs.anl.gov; lusk@mcs.anl.gov; jsquyres@cisco.com OI Gropp, William/0000-0003-2905-3029 NR 5 TC 3 Z9 3 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-39110-X J9 LECT NOTES COMPUT SC PY 2006 VL 4192 BP 115 EP 122 PG 8 WC Computer Science, Theory & Methods SC Computer Science GA BFF20 UT WOS:000241557200012 ER PT S AU Latham, R Ross, R Thakur, R AF Latham, Robert Ross, Robert Thakur, Rajeev BE Mohr, B Traff, JL Worringen, J Dongarra, J TI Can MPI be used for persistent parallel services? SO RECENT ADVANCES IN PARALLEL VIRTUAL MACHINE AND MESSAGE PASSING INTERFACE SE Lecture Notes in Computer Science LA English DT Article; Proceedings Paper CT 13th European Parallel-Virtual-Machine-and-Message-Passing-Interface-Users-Group Meeting (PVM/MPI) CY SEP 17-20, 2006 CL Bonn, GERMANY SP Parallel Virtual Machine & Message Passing Interface Users Grp, Etnus, IBM, intel, NEC, Dolphin Interconnect Solut, Hewlett Packard, Microsoft, Sun, QLogic AB MPI is routinely used for writing parallel applications, but it is not commonly used for writing long-running parallel services, such as parallel file systems or job schedulers. Nonetheless, MPI does have many features that are potentially useful for writing such software. Using the PVFS2 parallel file system as a motivating example, we studied the needs of software that provide persistent parallel services and evaluated whether MPI is a good match for those needs. We also ran experiments to determine the gaps between what the MPI Standard enables and what MPI implementations currently support. The results of our study indicate that MPI can enable persistent parallel systems to be developed with less effort and can provide high performance, but MPI implementations will need to provide better support for certain features. We also describe an area where additions to the MPI Standard would be useful. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Latham, R (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM robl@mcs.anl.gov; rross@mcs.anl.gov; thakur@mcs.anl.gov OI Latham, Rob/0000-0002-5285-6375 NR 13 TC 3 Z9 3 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-39110-X J9 LECT NOTES COMPUT SC PY 2006 VL 4192 BP 275 EP 284 PG 10 WC Computer Science, Theory & Methods SC Computer Science GA BFF20 UT WOS:000241557200030 ER PT S AU Doerfler, D Brightwell, R AF Doerfler, Douglas Brightwell, Ron BE Mohr, B Traff, JL Worringen, J Dongarra, J TI Measuring MPI send and receive overhead and application availability in high performance network interfaces SO RECENT ADVANCES IN PARALLEL VIRTUAL MACHINE AND MESSAGE PASSING INTERFACE SE Lecture Notes in Computer Science LA English DT Article; Proceedings Paper CT 13th European Parallel-Virtual-Machine-and-Message-Passing-Interface-Users-Group Meeting (PVM/MPI) CY SEP 17-20, 2006 CL Bonn, GERMANY SP Parallel Virtual Machine & Message Passing Interface Users Grp, Etnus, IBM, intel, NEC, Dolphin Interconnect Solut, Hewlett Packard, Microsoft, Sun, QLogic DE MPI; overhead; availability; high performance computing; high speed networks AB In evaluating new high-speed network interfaces, the usual metrics of latency and bandwidth are commonly measured and reported. There are numerous other message passing characteristics that can have a dramatic effect on application performance that should be analyzed when evaluating a new interconnect. One such metric is overhead, which dictates the networks ability to allow the application to perform non-message passing work while a transfer is taking place. A method for measuring overhead, and hence calculating application availability, is presented. Results for several next-generation network interfaces are also presented. C1 Sandia Natl Labs, Ctr Computat Comp Informat & Math, Albuquerque, NM 87185 USA. RP Doerfler, D (reprint author), Sandia Natl Labs, Ctr Computat Comp Informat & Math, POB 5800, Albuquerque, NM 87185 USA. EM dwdoerf@sandia.gov; rbbrigh@sandia.gov NR 9 TC 6 Z9 6 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-39110-X J9 LECT NOTES COMPUT SC PY 2006 VL 4192 BP 331 EP 338 PG 8 WC Computer Science, Theory & Methods SC Computer Science GA BFF20 UT WOS:000241557200036 ER PT S AU Underwood, KD AF Underwood, Keith D. BE Mohr, B Traff, JL Worringen, J Dongarra, J TI Challenges and issues in benchmarking MPI SO RECENT ADVANCES IN PARALLEL VIRTUAL MACHINE AND MESSAGE PASSING INTERFACE SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 13th European Parallel-Virtual-Machine-and-Message-Passing-Interface-Users-Group Meeting (PVM/MPI) CY SEP 17-20, 2006 CL Bonn, GERMANY SP Parallel Virtual Machine & Message Passing Interface Users Grp, Etnus, IBM, intel, NEC, Dolphin Interconnect Solut, Hewlett Packard, Microsoft, Sun, QLogic AB Benchmarking MPI is a contentious subject at best. Micro-benchmarks are used because they are easy to port and, hypothetically, measure an important system characteristic in isolation. The unfortunate reality is that it is remarkably difficult to create a benchmark that is a fair measurement in the context of modern system. Software optimizations and modern processor architecture perform extremely efficiently on benchmarks, where it would not in an application context. This paper explores the challenges faced when benchmarking the network in a modern microprocessor climate and the remarkable impacts on the results that are obtained. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Underwood, KD (reprint author), Sandia Natl Labs, POB 5800,MS-1110, Albuquerque, NM 87185 USA. EM kdunder@sandia.gov NR 12 TC 3 Z9 3 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-39110-X J9 LECT NOTES COMPUT SC PY 2006 VL 4192 BP 339 EP 346 PG 8 WC Computer Science, Theory & Methods SC Computer Science GA BFF20 UT WOS:000241557200037 ER PT S AU Trinitis, C Schulz, M AF Trinitis, Carsten Schulz, Martin BE Mohr, B Traff, JL Worringen, J Dongarra, J TI 5(th) International Special Session on Current Trends in Numerical Simulation for Parallel Engineering Environments - New directions and work-in-progress - ParSim 2006 SO RECENT ADVANCES IN PARALLEL VIRTUAL MACHINE AND MESSAGE PASSING INTERFACE SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 13th European Parallel-Virtual-Machine-and-Message-Passing-Interface-Users-Group Meeting (PVM/MPI) CY SEP 17-20, 2006 CL Bonn, GERMANY SP Parallel Virtual Machine & Message Passing Interface Users Grp, Etnus, IBM, intel, NEC, Dolphin Interconnect Solut, Hewlett Packard, Microsoft, Sun, QLogic C1 Tech Univ Munich, Inst Informat, LRR, D-8000 Munich, Germany. Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA USA. RP Trinitis, C (reprint author), Tech Univ Munich, Inst Informat, LRR, D-8000 Munich, Germany. EM Carsten.Trinitis@in.tum.de; schulzm@llnl.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-39110-X J9 LECT NOTES COMPUT SC PY 2006 VL 4192 BP 356 EP 357 PG 2 WC Computer Science, Theory & Methods SC Computer Science GA BFF20 UT WOS:000241557200039 ER PT S AU Babic, B Radmilovic, V Krstajic, N Kaludjerovic, B AF Babic, B. Radmilovic, V. Krstajic, N. Kaludjerovic, B. BE Uskokovic, DP Milonjic, SK Rakovic, DI TI Electrooxidation of hydrogen on nanostructured Pt/C catalysts for polymer electrolyte fuel cells SO RECENT DEVELOPMENTS IN ADVANCED MATERIALS AND PROCESSES SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 7th Conference of the Yugoslav-Materials-Research-Society (Yu-MRS) CY SEP 12-16, 2005 CL Herceg Novi, SERBIA MONTENEG SP Yugoslav Mat Res Soc DE carbon cryogel; hydrogen oxidation; platinum catalyst ID CARBON; OXIDATION; PLATINUM AB Mesoporous carbon cryogel synthesized by sol-gel polycondensation and freeze-drying with specific surface area (BET) of 517 m(2) g(-1) was used as a catalyst support. Pt/C catalysts were prepared by a modified ethylene glycol method (EG). Transmission electron microscopy (TEM) images show that the dispersion of the catalyst is very uniform with a mean particle size of about 2.65 nm. Hydrogen oxidation reaction (HOR) was studied on Pt/C catalyst in 0.5 mol dm(-3) HClO4 acid solution. It has been found that HOR appears as a reversible two-electron direct discharged reaction (Tafel slope for this reaction is approximate to 30mV dec(-1)) and that Pt/C catalyst exhibits a very high catalytic activity. However, the corresponding value of the exchange current density obtained by dividing the exchange current by the active surface area of Pt particles has the same order of magnitude as those for the HOR in acidic solution at single crystal and polycrystalline Pt. C1 Vinca Inst Nucl Sci, Belgrade 11001, Serbia. LBL, Div Mat Sci, Berkeley, CA USA. Univ Belgrade, Fac Technol & Met, Belgrade, Serbia. RP Babic, B (reprint author), Vinca Inst Nucl Sci, POB 522, Belgrade 11001, Serbia. EM babicb@vin.bg.ac.yu NR 12 TC 0 Z9 0 U1 0 U2 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2006 VL 518 BP 283 EP 288 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA BES77 UT WOS:000239351800047 ER PT S AU Ivetic, T Nikolic, MV Young, DL Vasiljevic-Radovic, D Urosevic, D AF Ivetic, T. Nikolic, M. V. Young, D. L. Vasiljevic-Radovic, D. Urosevic, D. BE Uskokovic, DP Milonjic, SK Rakovic, DI TI Photoacoustic and optical properties of zinc-stannate thin films SO RECENT DEVELOPMENTS IN ADVANCED MATERIALS AND PROCESSES SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 7th Conference of the Yugoslav-Materials-Research-Society (Yu-MRS) CY SEP 12-16, 2005 CL Herceg Novi, SERBIA MONTENEG SP Yugoslav Mat Res Soc DE photoacoustic spectroscopy; thin films; thermal diffusivity; zinc-stannate ID TRANSPARENT CONDUCTING OXIDES; ZN2SNO4; NANOBELTS AB Thin films of single-phase zinc-stannate (Zn2SnO4) were grown by rf magnetron sputtering onto glass substrates. Transmission in the visible range was measured allowing determination of the energy gap and thickness of analyzed thin film samples using interference fringes. The photoacoustic phase and amplitude spectra of all samples were measured as a function of the laser beam modulating frequency using a transmission detection configuration. Fitting of experimental data enabled calculation of thermal diffusivity, the coefficient of minority carrier diffusion, their mobility and lifetime. C1 Serbian Acad Arts & Sci, Inst Tech Sci, Belgrade 11000, Serbia. Univ Belgrade, Ctr Multidisciplinary Studies, Belgrade 11000, Serbia. Natl Renewable Energy Lab, Golden, CO 80401 USA. Inst Microelect & Single Crystals, Belgrade 11000, Serbia. SASA, Math Inst, Belgrade 11000, Serbia. RP Ivetic, T (reprint author), Serbian Acad Arts & Sci, Inst Tech Sci, Belgrade 11000, Serbia. EM tamara@itn.sanu.ac.yu; maria@mi.sanu.ac.yu; david_young@nrel.gov; dana@nanosys.ihtm.bg.ac.yu; draganu@turing.mi.sanu.ac.yu RI Vasiljevic-Radovic, Dana/C-8034-2016; OI Vasiljevic-Radovic, Dana/0000-0002-7609-8599; Nikolic, Maria/0000-0001-5035-0170 NR 21 TC 5 Z9 5 U1 0 U2 3 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2006 VL 518 BP 465 EP 470 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA BES77 UT WOS:000239351800076 ER PT S AU Straatsma, TP AF Straatsma, T. P. BE Simos, T Maroulis, G TI Lipopolysaccharide membranes and membrane proteins of pseudomonas aeruginosa studied by computer simulation SO RECENT PROGRESS IN COMPUTATIONAL SCIENCES AND ENGINEERING, VOLS 7A AND 7B SE LECTURE SERIES ON COMPUTER AND COMPUTATIONAL SCIENCES LA English DT Proceedings Paper CT International Conference on Computational Methods in Science and Engineering CY OCT 27-NOV 01, 2006 CL Chania, GREECE ID ESCHERICHIA-COLI; MOLECULAR-DYNAMICS; DRUG-RESISTANCE; CYSTIC-FIBROSIS; SEROTYPE O5; OMPA; DOMAIN; FORMS; CORE; CHANNELS AB Pseudomonas aeruginosa is a ubiquitous environmental Gram-negative bacterium with high metabolic versatility and an exceptional ability to adapt to a wide range of ecological environments, including soil, marches, coastal habitats, plant and animal tissues. Gram-negative microbes are characterized by the asymmetric lipopolysaccharide outer membrane, the study of which is important for a number of applications. The adhesion to mineral surfaces plays a central role in characterizing their contribution to the fate of contaminants in complex environmental systems by effecting microbial transport through soils, respiration redox chemistry, and ion mobility. Another important application stems from the fact that it is also a major opportunistic human pathogen that can result in life-threatening infections in many immunocompromised patients, such as lung infections in children with cystic fibrosis, bacteraemia in burn victims, urinary-tract infections in catheterized patients, hospital-acquired pneumonia in patients on respirators, infections in cancer patients receiving chemotherapy, and keratitis and corneal ulcers in users of extended-wear soft contact lenses. The inherent resistance against antibiotics which has been linked with the specific interactions in the outer membrane of P. aeruginoso makes these infections difficult to treat. Developments in simulation methodologies as well as computer hardware have enabled the molecular simulation of biological systems of increasing size and with increasing accuracy, providing detail that is difficult or impossible to obtain experimentally. Computer simulation studies contribute to our understanding of the behavior of proteins, protein-protein and protein-DNA complexes. In recent years, a number of research groups have made significant progress in applying these methods to the study of biological membranes. However, these applications have been focused exclusively on lipid bilayer membranes and on membrane proteins in lipid bilayers. A few simulation studies of outer membrane proteins of Gram-negative bacteria have been reported using simple lipid bilayers, even though this is not a realistic representation of the outer membrane environment. This contribution describes our recent molecular Simulation studies of the rough lipopolysaccharide membrane of P. aeruginosa, which are the first and only reported studies to date for a complete, periodic lipopolysaccharide outer membrane. This also includes our current efforts in building on our initial and unique experience simulating the lipopolysaccharide membrane in the development and application of novel computational procedures and tools that allow molecular simulation studies of outer membrane proteins of Gram-negative bacteria to be carried out in realistic membrane models. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Straatsma, TP (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 37 TC 0 Z9 0 U1 1 U2 4 PU VSP BV-C/O BRILL ACAD PUBL PI LEIDEN PA PO BOX 9000, 2300 PA LEIDEN, NETHERLANDS SN 1573-4196 BN 978-90-04-15542-8 J9 LECT SER COMPUTER CO PY 2006 VL 7A-B BP 519 EP 524 PG 6 WC Mathematics, Applied SC Mathematics GA BHM78 UT WOS:000254378800124 ER PT S AU Tretiak, S Katan, C Terenziani, F Blanchard-Desce, M AF Tretiak, S. Katan, C. Terenziani, F. Blanchard-Desce, M. BE Simos, T Maroulis, G TI Nonlinear optical response and photodynamics of conjugated molecules: Effects of branching and substitution SO RECENT PROGRESS IN COMPUTATIONAL SCIENCES AND ENGINEERING, VOLS 7A AND 7B SE LECTURE SERIES ON COMPUTER AND COMPUTATIONAL SCIENCES LA English DT Proceedings Paper CT International Conference on Computational Methods in Science and Engineering CY OCT 27-NOV 01, 2006 CL Chania, GREECE DE time-dependent density functional theory (TDDFT); frequency dependent nonlinear polarizabilities; two-photon absorption (TPA); branched conjugated chromophores; Frenkel-exciton model ID DENSITY-FUNCTIONAL THEORY; 2-PHOTON ABSORPTION; CHROMOPHORES AB Photoexcited dynamics and nonlinear optical response of organic chromophores are investigated using time-dependent density functional theory (TDDFT). Closed expressions for frequency dependent polarizabilities up to the third order are derived and computationally implemented. We find that TDDFT reproduces well the energetics of both one-photon (linear absorption) and two-photon (TPA) states in a variety of donor-acceptor substituted molecules. The absolute magnitudes of TPA cross-sections have a good agreement with experiment as well. Several structurally related large chromophores of different symmetry are further investigated and compared for elucidation of the combined role of branching and charge symmetry on photoluminescence and nonlinear optical response. Branching is observed to lead to both cooperative enhancement of TPA while ensuring high fluorescence quantum yield. New strategies for molecular engineering of nonlinear optical materials are inferred. C1 [Tretiak, S.] Los Alamos Natl Lab, Div Theoret, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Tretiak, S (reprint author), Los Alamos Natl Lab, Div Theoret, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. EM serg@lanl.gov RI Tretiak, Sergei/B-5556-2009; Terenziani, Francesca/K-2951-2015; KATAN, Claudine/I-9446-2012 OI Tretiak, Sergei/0000-0001-5547-3647; Terenziani, Francesca/0000-0001-5162-9210; KATAN, Claudine/0000-0002-2017-5823 NR 14 TC 0 Z9 0 U1 0 U2 2 PU VSP BV-C/O BRILL ACAD PUBL PI LEIDEN PA PO BOX 9000, 2300 PA LEIDEN, NETHERLANDS SN 1573-4196 BN 978-90-04-15542-8 J9 LECT SER COMPUTER CO PY 2006 VL 7A-B BP 1266 EP 1269 PG 4 WC Mathematics, Applied SC Mathematics GA BHM78 UT WOS:000254378800306 ER PT B AU Ortiz, G Somma, R Barnum, H Knill, E AF Ortiz, Gerardo Somma, Rolando Barnum, Howard Knill, Emanuel BE Hernandez, S Cataldo, H TI Limits on the power of some models of quantum computation SO Recent Progress in Many-Body Theories, Proceedings SE Series on Advances in Quantum Many-Body Theory LA English DT Proceedings Paper CT 13th International Conference on Recent Progress in Many-Body Theories CY DEC 05-09, 2005 CL Univ Buenos Aires, Buenos Aires, ARGENTINA HO Univ Buenos Aires DE quantum computation; lie algebraic quantum models; computational complexity; generalized entanglement ID COMPACT LIE-ALGEBRAS; COHERENT STATES AB We consider quantum computational models defined via a Lie-algebraic theory. In these models, specified initial states are acted on by Lie-algebraic quantum gates and the expectation values of Lie algebra elements are measured at the end. We show that these models can be efficiently simulated on a classical computer in time polynomial in the dimension of the algebra, regardless of the dimension of the Hilbert space where the algebra acts. Similar results hold for the computation of the expectation value of operators implemented by a gate-sequence. We introduce a Lie-algebraic notion of generalized mean-field Hamiltonians and show that they are efficiently (exactly) solvable by means of a Jacobi-like diagonalization method. Our results generalize earlier ones on fermionic linear optics computation and provide insight into the source of the power of the conventional model of quantum computation. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Ortiz, G (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 29 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 978-981-270-035-3 J9 SER ADV QUANT MANY B PY 2006 VL 10 BP 158 EP 167 DI 10.1142/9789812772787_0018 PG 10 WC Physics, Multidisciplinary SC Physics GA BFU91 UT WOS:000244734300018 ER PT S AU Borovsky, JE Steinberg, JT AF Borovsky, Joseph E. Steinberg, John T. BE Tsurutani, B McPherron, R Gonzalez, W Lu, G Sobral, JHA Gopalswamy, N TI The freestream turbulence effect in Solar-Wind/Magnetosphere coupling: Analysis through the solar cycle and for various types of solar wind SO Recurrent Magnetic Storms: Corotating Solar Wind Streams SE GEOPHYSICAL MONOGRAPH SERIES LA English DT Proceedings Paper CT America-Geophysical-Union-Chapman Conference CY FEB 06-12, 2005 CL Manaus, BRAZIL SP Amer Geophys Union Chapman ID PROTON TEMPERATURE; BOUNDARY-LAYER; REGIONS; WAKE AB The freestream turbulence effect is a viscous interaction between the solar wind and the Earth's magnetosphere wherein the driving of the magnetosphere is stronger when the amplitude of the solar-wind turbulence upstream of the Earth is stronger. The origin of the effect is an eddy viscosity of the solar wind controlled by the amplitude of the ambient MHD turbulence. The present study investigates outstanding issues about the operation of the turbulence effect. For this study, a large solar-wind/magnetosphere data set is assembled: to the 1963-2001 OMNI2 data set, 1-hour-lagged values of the auroral-electrojet index are added. The 1963-2001 OMNI2-AE(1), data set has similar to 193,000 hours of data that can be used to study magnetospheric driving by the turbulence effect. The freestream turbulence effect is analyzed for southward IMF by holding -vB(z) fixed in the data set. Under modest southward IMF, the turbulence effect has the same strength as it does under northward IME For large -vBz where reconnection driving is strong the ability to measure the freestream turbulence effect deteriorates owing to signal-to-noise issues. The freestream turbulence effect was analyzed for 3 solar cycles of data: a weak solar-cycle dependence to the strength of the turbulence effect was found. A categorization of the solar wind was developed from the temperature-versus-speed plot for the solar wind. Using these categorizations, plus data with restrictions on the sunspot number, plus catalogs of solar-wind events, no differences in the freestream turbulence effect were seen between different types of solar wind hitting the magnetosphere. C1 Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Borovsky, JE (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. RI Gopalswamy, Nat/D-3659-2012; OI Steinberg, John/0000-0003-2491-1661 NR 28 TC 8 Z9 8 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0065-8448 BN 978-0-87590-432-0 J9 GEOPH MONOG SERIES PY 2006 VL 167 BP 59 EP 76 DI 10.1029/167GM07 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA BFX14 UT WOS:000245238200005 ER PT S AU Jordanova, VK AF Jordanova, Vania K. BE Tsurutani, B McPherron, R Gonzalez, W Lu, G Sobral, JHA Gopalswamy, N TI Modeling the behavior of corotating interaction region driven storms in comparison with coronal mass ejection driven storms SO Recurrent Magnetic Storms: Corotating Solar Wind Streams SE GEOPHYSICAL MONOGRAPH SERIES LA English DT Proceedings Paper CT America-Geophysical-Union-Chapman Conference CY FEB 06-12, 2005 CL Manaus, BRAZIL SP Amer Geophys Union Chapman ID RING CURRENT; GEOMAGNETIC STORMS; ELECTRIC-FIELD; INTERPLANETARY ORIGIN; GEOSYNCHRONOUS ORBIT; MAGNETIC STORMS; ION COMPOSITION; SOLAR-CYCLE; SIMULATIONS; STREAMS AB There are two types of geoeffective solar disturbances, single events like coronal mass ejections that pass Earth once, or structures like corotating interaction regions which corotate with the Sun and could pass Earth on successive rotations. We use our kinetic ring current-atmosphere interactions model (RAM) to simulate ring current evolution during two geomagnetic storms of similar strength representative of each solar origin, the 15 May 1997 and the 10 March 1998, and compare the mechanisms responsible for trapping particles and for causing their loss. A quiet time ring current distribution inferred from satellite data is used as initial conditions, and ring current intensification due to enhanced plasma inflow from the magnetotail and earthward transport and acceleration is considered. Using an electric potential model driven by interplanetary parameters, we find that the ring current injection calculated with RAM is in good agreement with Dst index during May 1997, however, it underestimates Dst during March 1998. Additional intensifications by radial diffusion during March 1998 reproduce better its long lasting recovery phase. The dominant ring current ion during both storms is H+, while O+ and He+ are minor constituents. The strongest electromagnetic ion cyclotron waves are generated in the postnoon local time sector and along the plasmapause; these waves cause similar to 5% decrease of the total ring current energy by proton precipitation during May 1997. Charge exchange is the dominant loss process during the storm recovery phase; the net convective losses are larger than charge exchange losses only for few hours near Dst minima. C1 Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Jordanova, VK (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. RI Gopalswamy, Nat/D-3659-2012; OI Jordanova, Vania/0000-0003-0475-8743 NR 34 TC 12 Z9 12 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0065-8448 BN 978-0-87590-432-0 J9 GEOPH MONOG SERIES PY 2006 VL 167 BP 77 EP 84 DI 10.1029/167GM08 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA BFX14 UT WOS:000245238200006 ER PT S AU Phinney, LM Spahn, OB Wong, CC AF Phinney, Leslie M. Spahn, Olga Blum Wong, C. Channy BE Tanner, DM Ramesham, R TI Experimental and computational study on laser heating of surface micromachined cantilevers - art. no. 611108 SO Reliability, Packaging, Testing, and Characterization of MEMS/ MOEMS V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Reliability, Packaging, Testing, and Characterization of MEMS/MOEMS V CY JAN 25-26, 2006 CL San Jose, CA SP SPIE DE laser damage of MEMS; optical MEMS; MOEMS; polycrystalline silicon ID DAMAGE AB Microsystems are potentially exposed to laser irradiation during processing, diagnostic measurements, and, in some cases, device operation. The behavior of the components in an optical MEMS device that are irradiated by a laser needs to be optimized for reliable operation. Utilizing numerical simulations facilitates design and optimization. This paper reports on experimental and numerical investigations of the thermomechanical response of polycrystalline silicon microcantilevers that are 250 mu m wide, 500 mu m long, and 2.25 mu m thick when heated by an 808 nm laser. At laser powers above 400 mW significant deflection is observed during the laser pulse using a white light interferometer. Permanent deformation is detected at laser powers above 650 mW in the experiments. Numerical calculations using a coupled physics finite element code, Calagio, agree qualitatively with the experimental results. Both the experimental and numerical results reveal that the initial stress state is very significant. Microcantilevers deflect in the direction of their initial deformation upon irradiation with a laser. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Phinney, LM (reprint author), Sandia Natl Labs, POB 5800 MS 1310, Albuquerque, NM 87185 USA. NR 11 TC 1 Z9 1 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 0-8194-6153-9 J9 P SOC PHOTO-OPT INS PY 2006 VL 6111 BP 11108 EP 11108 AR 611108 DI 10.1117/12.647487 PG 7 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Optics SC Engineering; Optics GA BEF47 UT WOS:000237090900008 ER PT S AU Reu, PL Tanner, DM Epp, DS Parson, TB Boyce, BL AF Reu, Phillip L. Tanner, Danelle M. Epp, David S. Parson, Ted B. Boyce, Brad L. BE Tanner, DM Ramesham, R TI Experimental apparatus and software design for dynamic long-term reliability testing of a spring-mass MEMS device SO RELIABILITY, PACKAGING, TESTING, AND CHARACTERIZATION OF MEMS/ MOEMS V SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Reliability, Packaging, Testing, and Characterization of MEMS/MOEMS V CY JAN 25-26, 2006 CL San Jose, CA SP SPIE DE reliability; resonant frequency; dynamic testing; modal testing; LDV; Doppler; MEMS; fatigue; aging ID SINGLE-CRYSTAL SILICON; HIGH-CYCLE FATIGUE; POLYCRYSTALLINE SILICON; THIN-FILMS AB Long-term reliability testing of Micro-Electro-Mechanical Systems (MEMS) is important to the acceptance of these devices for critical and high-impact applications. In order to make predictions on aging mechanisms, these validation experiments must be performed in controlled environments. Additionally, because the aging acceleration factors are not understood, the experiments can last for months. This paper describes the design and implementation of a long-term MEMS reliability test bed for accelerated life testing. The system is comprised of a small environmental chamber mounted on an electrodynamic shaker with a laser Doppler vibrometer (LDV) and digital camera for data collection. The humidity and temperature controlled chamber has capacity for 16 MEMS components in a 4x4 array. The shaker is used to dynamically excite the devices using broadband noise, chirp or any other programmed signal via the control software. Driving amplitudes can be varied to maintain the actuation of the test units at the desired level. The actuation is monitored optically via the LDV which can report the displacement or velocity information of the surface. A spring-mass accelerated aging experiment was started using a controlled environment of 5000 ppmv humidity (roughly 13% at room temperature), temperature of 29 degrees C, and +/- 80 mu m maximum displacement of the mass. During the first phase of the experiment., the resonant frequency was measured every 2 hours. From 114.5 to 450 hours under stress, measurements were taken every 12 hours and after that every 24 hours. Resonant frequency tracking indicates no changes in the structures for 4200 hours of testing. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Reu, PL (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. EM plreu@sandia.gov RI Boyce, Brad/H-5045-2012 OI Boyce, Brad/0000-0001-5994-1743 NR 7 TC 0 Z9 0 U1 0 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 0-8194-6153-9 J9 PROC SPIE PY 2006 VL 6111 AR 61110J DI 10.1117/12.648488 PG 9 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Optics SC Engineering; Optics GA BEF47 UT WOS:000237090900019 ER PT B AU Desjarlais, A Petrie, T Miller, W Gillenwater, R Roodvoets, D AF Desjarlais, A. Petrie, T. Miller, W. Gillenwater, R. Roodvoets, D. BE Fazio, P Ge, H Rao, J Desmarais, G TI Evaluating the energy performance of ballasted roof systems SO Research in Building Physics and Building Engineering SE Proceedings and Monographs in Engineering, Water and Earth Sciences LA English DT Proceedings Paper CT 3rd International Building Physics Conference CY AUG 27-31, 2006 CL Concordia Univ, Montreal, CANADA HO Concordia Univ AB It is well known that the mass of a ballasted roof can reduce peak roof temperatures and delay the heat flow into a building. Although ballasted roofs perform similar functions they do not meet the traditional requirements of high solar reflectance and high thermal emittance set out by the Environmental Protection Agency (EPA) and other organizations regarding being a "cool roof." To address whether ballasted roofing systems offer similar energy efficiency benefits as cool roofs, a project to perform side-by-side experiments was initiated. Data from these experiments will answer what impact a ballasted roof has on heat flow into a building and on roof surface temperature. Furthermore, comparisons between the ballasted and unballasted membranes will allow for an assessment of whether ballasted systems perform as well as white membranes and are deserving of a "cool roof" status within the codes. C1 Oak Ridge Natl Lab, Oak Ridge, TN USA. RP Desjarlais, A (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN USA. NR 7 TC 0 Z9 0 U1 1 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND BN 0-415-41675-2 J9 PROC MONOGR ENG WATE PY 2006 BP 473 EP 478 PG 6 WC Construction & Building Technology SC Construction & Building Technology GA BFL57 UT WOS:000242847800060 ER PT J AU Sasaki, K Zhang, JL Wang, J Uribe, F Adzic, R AF Sasaki, Kotaro Zhang, Junliang Wang, Jia Uribe, Francisco Adzic, Radoslav TI Platinum submonolayer-monolayer electrocatalysts: an electrochemical and X-ray absorption spectroscopy study SO RESEARCH ON CHEMICAL INTERMEDIATES LA English DT Review DE platinum monolayer electrocatalyst; submonolayer; nanoparticle; X-ray absorption spectroscopy ID CARBON-MONOXIDE; RU NANOPARTICLES; O-2 REDUCTION; METAL-SURFACES; OH ADSORPTION; CO; OXIDATION; CHEMISORPTION; ELECTROLYTE; TRANSITION AB A new Pt monolayer electrocatalyst concept is described and the results of electrochemical and X-ray absorption spectroscopy (XAS) studies are presented. Two new methods that facilitate the application of this concept in obtaining ultra-low-Pt-content electrocatalysts have been developed. One is the electroless (spontaneous) deposition of a Pt submonolayer on Ru nanoparticles, and the other is a deposition of a Pt monolayer on Pd nanoparticles by redox displacement of a Cu adlayer. The Pt submonolayer on Ru (PtRu20) electrocatalyst demonstrated higher CO tolerance than commercial catalysts under conditions of rotating disk experiments. The long-term stability test showed no loss in performance over 870 h using a fuel cell operating under real conditions, even though the Pt loading was approximately 10% of that of the standard Pt loading. In situ XAS indicated an increase in d-band vacancy of deposited Pt, which may facilitate partly the reduced susceptibility to CO poisoning for this catalyst. The kinetics of O-2 reduction on a Pt monolayer on Pd nanoparticles showed a small enhancement in comparison with that from a Pt nanoparticle electrocatalyst. The increase in catalytic activity is partly attributed to decreased formation of PtOH, as shown by XAS experiments. C1 Brookhaven Natl Lab, Dept Mat Sci, Upton, NY 11973 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Adzic, R (reprint author), Brookhaven Natl Lab, Dept Mat Sci, Upton, NY 11973 USA. EM adzic@bnl.gov NR 37 TC 16 Z9 16 U1 3 U2 30 PU VSP BV PI LEIDEN PA BRILL ACADEMIC PUBLISHERS, PO BOX 9000, 2300 PA LEIDEN, NETHERLANDS SN 0922-6168 J9 RES CHEM INTERMEDIAT JI Res. Chem. Intermed. PY 2006 VL 32 IS 5-6 BP 543 EP 559 DI 10.1163/156856706777973646 PG 17 WC Chemistry, Multidisciplinary SC Chemistry GA 082QG UT WOS:000240401200017 ER PT S AU Castelnau, O Goudeau, P Geandier, G Tamura, N Bechade, JL Bornert, M Caldemaison, D AF Castelnau, O. Goudeau, P. Geandier, G. Tamura, N. Bechade, J. L. Bornert, M. Caldemaison, D. BE Reimers, W Quander, S TI White beam microdiffraction experiments for the determination of the local plastic behaviour of polycrystals SO RESIDUAL STRESSES VII SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 7th European Conference on Residual Stresses (ERCS 7) CY SEP 13-15, 2006 CL Berlin, GERMANY DE microdiffraction; polycrystal; plasticity; micromechanics; residual stresses ID TEXTURE; ALLOYS; STRAIN AB The overall plastic behavior of polycrystalline materials strongly depends on the microstructure and on the local rheology of individual grains. The characterization of the strain and stress heterogeneities within the specimen, which result from the intergranular mechanical interactions, is of particular interest since they largely control the microstructure evolutions such as texture development, work-hardening, damage, recrystallization, etc. The influence of microstructure on the effective behavior can be addressed by physical-based predictive models (homogenization schemes) based either on full-field or on mean-field approaches. But these models require the knowledge of the grain behavior, which in turn must be determined on the real specimen under investigation. The microextensometry technique allows the determination of the surface total (i.e. plastic + elastic) strain field with a micrometric spatial resolution. On the other hand, the white beam X-ray microdiffraction technique developed recently at the Advanced Light Source enables the determination of the elastic strain with the same spatial resolution. For polycrystalline materials with grain size of about 10 micrometers, a complete intragranular mechanical characterization can thus be performed by coupling these two techniques. The very first results obtained on plastically deformed copper and zirconium specimens are presented. C1 Univ Paris 13, CNRS, LPMTM, F-93430 Villetaneuse, France. Univ Poitiers, LMP, F-86962 Futuroscope, France. Lawrence Berkeley Lab, ALS, Berkeley, CA 94720 USA. CEA Saclay, DEN, DMN, SRMA,LA2M, F-91191 Gif Sur Yvette, France. Ecole Polytech, LMS, F-91128 Palaiseau, France. RP Castelnau, O (reprint author), Univ Paris 13, CNRS, LPMTM, Av JB Clement, F-93430 Villetaneuse, France. EM oc@ipmtm.univ-paris13.fr; Philippe.Goudeau@univ-poitiers.fr; GGeandier@lbl.gov; NTamura@lbl.gov; jean-luc.bechade@cea.fr; bornert@lms.polytechnique.fr; caldema@lms.polytechnique.fr RI castelnau, olivier/E-7789-2011 OI castelnau, olivier/0000-0001-7422-294X NR 16 TC 3 Z9 3 U1 0 U2 0 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2006 VL 524-525 BP 103 EP 108 PG 6 WC Instruments & Instrumentation; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Instruments & Instrumentation; Materials Science GA BFD54 UT WOS:000241187200016 ER PT S AU Woo, W Feng, Z Wang, XL An, K Bailey, WB David, SA Hubbard, CR Choo, H AF Woo, W. Feng, Z. Wang, X. -L. An, K. Bailey, W. B. David, S. A. Hubbard, C. R. Choo, H. BE Reimers, W Quander, S TI Feasibility of thermal strain measurements during quasi-steady state using neutron diffraction SO RESIDUAL STRESSES VII SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 7th European Conference on Residual Stresses (ERCS 7) CY SEP 13-15, 2006 CL Berlin, GERMANY DE thermal strain; quasi-steady state; neutron diffraction; aluminum alloys ID RESIDUAL-STRESS; IN-SITU; ALLOY; TRANSFORMATION; COMPOSITES; BEHAVIOR; FE AB Localized heating was imposed on a 6061-T6 aluminum alloy plate to cause thermal strains, and simultaneously interplanar spacing changes were measured using in-situ time-resolved neutron diffraction techniques. Two different methods were used: 1) direct real-time measurements of the transient behavior and 2) a series of measurements based on the quasi-steady state (QSS) principle. A comparison of the two results shows that the QSS method can represent the transient behavior under the current experimental conditions. C1 Univ Tennessee, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. RP Woo, W (reprint author), Univ Tennessee, Knoxville, TN 37996 USA. EM wwoo@utk.edu; fengz@ornl.gov; wangxl@ornl.gov; kean@ornl.gov; baileywb@ornl.gov; davidsa1@ornl.gov; hubbardcr@ornl.gov; hchoo@utk.edu RI Wang, Xun-Li/C-9636-2010; Choo, Hahn/A-5494-2009; Feng, Zhili/H-9382-2012; An, Ke/G-5226-2011; OI Wang, Xun-Li/0000-0003-4060-8777; Choo, Hahn/0000-0002-8006-8907; Feng, Zhili/0000-0001-6573-7933; An, Ke/0000-0002-6093-429X; WOO, Wanchuck/0000-0003-0350-5357 NR 17 TC 7 Z9 7 U1 0 U2 4 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2006 VL 524-525 BP 387 EP 392 PG 6 WC Instruments & Instrumentation; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Instruments & Instrumentation; Materials Science GA BFD54 UT WOS:000241187200060 ER PT S AU Terner, MR Hedstrom, P Almer, J Ilavsky, J Oden, M AF Terner, M. R. Hedstrom, P. Almer, J. Ilavsky, J. Oden, M. BE Reimers, W Quander, S TI Residual stress evolution during decomposition of Ti((1-x))Al((x))N coatings using high-energy x-rays SO RESIDUAL STRESSES VII SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 7th European Conference on Residual Stresses (ERCS 7) CY SEP 13-15, 2006 CL Berlin, GERMANY DE ceramic coatings; TiAlN; WAXS; SAXS; x-ray scattering; small-angle x-ray scattering; synchrotron radiation; x-ray diffraction AB Residual stresses and microstructural changes during phase separation in Ti33Al67N coatings were examined using microfocused high energy x-rays from a synchrotron source. The transmission geometry allowed simultaneous acquisition of x-ray diffraction data over 360 degrees and revealed that the decomposition at elevated temperatures occurred anisotropically, initiating preferentially along the film plane. The as-deposited compressive residual stress in the film plane first relaxed with annealing, before dramatically increasing concurrently with the initial stage of phase separation where metastable, nm-scale c-AlN platelets precipitated along the film direction. These findings were further supported from SAXS analyses. C1 Lulea Univ Technol, Div Engn Mat, SE-97187 Lulea, Sweden. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Terner, MR (reprint author), Lulea Univ Technol, Div Engn Mat, SE-97187 Lulea, Sweden. EM mark.terner@ltu.se; peter.hedstrom@ltu.se; almer@aps.anl.gov; ilavsky@aps.anl.gov; magnus.oden@ltu.se RI Oden, Magnus/E-9662-2010; Hedstrom, Peter/F-8920-2010; Ilavsky, Jan/D-4521-2013 OI Oden, Magnus/0000-0002-2286-5588; Hedstrom, Peter/0000-0003-1102-4342; Ilavsky, Jan/0000-0003-1982-8900 NR 7 TC 2 Z9 2 U1 0 U2 5 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2006 VL 524-525 BP 619 EP 624 PG 6 WC Instruments & Instrumentation; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Instruments & Instrumentation; Materials Science GA BFD54 UT WOS:000241187200096 ER PT S AU Tao, K Choo, H Li, H Clausen, B Brown, DW Jin, JE Lee, YK AF Tao, K. Choo, H. Li, H. Clausen, B. Brown, D. W. Jin, J. E. Lee, Y. K. BE Reimers, W Quander, S TI In situ neutron diffraction study on the mechanical behavior of an ultra-fine-grained steel SO RESIDUAL STRESSES VII SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 7th European Conference on Residual Stresses (ERCS 7) CY SEP 13-15, 2006 CL Berlin, GERMANY DE martensitic transformation; uItra-fine-grained steel; neutron diffraction; lattice strain ID BONDING ARB PROCESS; NANOSTRUCTURED METALS; BULK; DEFORMATION AB The martensitic phase transformation in an ultra fine grained (UFG) TRIP (transformation induced plasticity) steel with combination of high strength and high elongation was investigated during room temperature tensile test using in situ neutron diffraction. Two types of specimens, namely coarse grained (grain size of about 50 mu m) and ultra-fine-grained (grain size of about 350 nm) specimens were examined. The lattice strain evolution of the austenite and martensite phases was observed and the load partitioning between the phases was identified. C1 Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Mat Sci & Technol Div, Oak Ridge, TN 37831 USA. Los Alamos Natl Lab, Los Alamos Neutron Sci Ctr, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Yonsei Univ, Dept Met Engn, Seoul 120749, South Korea. RP Tao, K (reprint author), Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. EM ktao@utk.edu; hchoo@utk.edu; hqli@utk.ed; clausen@lanl.gov; dbrown@lanl.gov; chean76@hanmail.net; gyklee@yonsei.ac.kr RI Li, Hongqi/B-6993-2008; Choo, Hahn/A-5494-2009; Clausen, Bjorn/B-3618-2015 OI Choo, Hahn/0000-0002-8006-8907; Clausen, Bjorn/0000-0003-3906-846X NR 15 TC 1 Z9 1 U1 0 U2 3 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2006 VL 524-525 BP 639 EP 644 PG 6 WC Instruments & Instrumentation; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Instruments & Instrumentation; Materials Science GA BFD54 UT WOS:000241187200099 ER PT S AU Goudeau, P Faurie, D Girault, B Renault, PO Le Bourhis, E Villain, P Badawi, F Castelnau, O Brenner, R Bechade, JL Geandier, G Tamura, N AF Goudeau, P. Faurie, D. Girault, B. Renault, P. -O. Le Bourhis, E. Villain, P. Badawi, F. Castelnau, O. Brenner, R. Bechade, J. -L. Geandier, G. Tamura, N. BE Reimers, W Quander, S TI Strains, stresses and elastic properties in polycrystalline metallic thin films: in situ deformation combined with x-ray diffraction and simulation experiments SO RESIDUAL STRESSES VII SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 7th European Conference on Residual Stresses (ERCS 7) CY SEP 13-15, 2006 CL Berlin, GERMANY DE elasticity; thin films; size effects; diffraction; synchrotron; tensile testing; simulation ID CONSTANTS AB X-ray diffraction is used in combination with tensile testing for measuring elastic properties of metallic thin films. Size effect, elastic anisotropy and grain morphologies are considered in all these experiments and supported by different kind of numerical simulations operating at different length scales. Such instrumental studies are time consuming even if synchrotron sources are used. New experiments are under progress for reducing acquisition data and improving precision on strain measurements. After introducing briefly the main principles and results of our techniques, first promising measurements on nanometric W/Cu multilayers using 2D CCD detectors and high monochromatic flux at the Advanced Light Source Berkeley (USA) on beam line 11.3.1 are presented. In addition, simulation experiments for analyzing elasticity in textured gold film are discussed. C1 Univ Poitiers, LMP, F-86962 Futuroscope, France. Netherlands Inst Met Res, NL-2600 GA Delft, Netherlands. Univ Paris 13, CNRS, LPMTM, F-93430 Villetaneuse, France. CEA Saclay, DEN, DMN, SRMA LA2M, F-91191 Gif Sur Yvette, France. LBNL, ALS, Berkeley, CA 94720 USA. RP Goudeau, P (reprint author), Univ Poitiers, LMP, Ave Marie & Pierre Curie, F-86962 Futuroscope, France. EM PGoudeau@univ-poitiers.fr; Damien.Faurie@etu.univ-poitiers.fr; Baptiste.Girault@etu.univ-poitiers.fr; Pierre.Olivier.Renault@univ-poitiers.fr; Eric.Le.Bourhis@univ-poitiers.fr; Pascale.Villain@univ-poitiers.fr; Frederic.Badawi@univ-poitiers.fr; oc@lpmtm.univ-paris13.fr; rb@lpmtm.univ-paris13.fr; Jean-Luc.BECHADE@cea.fr; GGeandier@lbl.gov; NTamura@lbl.gov RI castelnau, olivier/E-7789-2011; Faurie, Damien/C-3028-2011; Le Bourhis, Eric/B-4568-2013; OI castelnau, olivier/0000-0001-7422-294X; Le Bourhis, Eric/0000-0003-0902-5899; renault, pierre olivier/0000-0002-0736-2333 NR 11 TC 2 Z9 2 U1 0 U2 3 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2006 VL 524-525 BP 735 EP 740 PG 6 WC Instruments & Instrumentation; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Instruments & Instrumentation; Materials Science GA BFD54 UT WOS:000241187200114 ER PT S AU Hedstrom, P Almer, J Lienert, U Oden, M AF Hedstrom, Peter Almer, Jon Lienert, Ulrich Oden, Magnus BE Reimers, W Quander, S TI Evolution of residual strains in metastable austenitic stainless steels and the accompanying strain induced martensitic transformation SO RESIDUAL STRESSES VII SE Materials Science Forum LA English DT Article; Proceedings Paper CT 7th European Conference on Residual Stresses (ECRS 7) CY SEP 13-15, 2006 CL Berlin, GERMANY DE residual stresses; strain induced martensitic transformation; stainless steels; synchrotron radiation; 3DXRD ID INDIVIDUAL GRAINS; POLYCRYSTALS; POWDERS AB The deformation behavior of metastable austenitic stainless steel AISI 301, suffering different initial cold rolling reduction, has been investigated during uniaxial tensile loading. In situ high-energy x-ray diffraction was employed to characterize the residual strain evolution and the strain induced martensitic transformation. Moreover, the 3DXRD technique was employed to characterize the deformation behavior of individual austenite grains during elastic and early plastic deformation. The cold rolling reduction was found to induce compressive residual strains in the austenite along rolling direction and balancing tensile residual strains in the alpha-martensite. The opposite residual strain state was found in the transverse direction. The residual strain states of five individual austenite grains in the bulk of a sample suffering 2% cold rolling reduction was found to be divergent. The difference among the grains, considering both the residual strains and the evolution of these, could not be solely explained by elastic and plastic anisotropy. The strain states of the five austenite grains are also a consequence of the local neighborhood. C1 Lulea Univ Technol, Div Engn Mat, SE-97187 Lulea, Sweden. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Hedstrom, P (reprint author), Lulea Univ Technol, Div Engn Mat, SE-97187 Lulea, Sweden. EM peter.hedstrom@ltu.se; almer@aps.anl.gov; lienert@aps.anl.gov; magnus.oden@ltu.se RI Oden, Magnus/E-9662-2010; Hedstrom, Peter/F-8920-2010 OI Oden, Magnus/0000-0002-2286-5588; Hedstrom, Peter/0000-0003-1102-4342 NR 8 TC 2 Z9 2 U1 0 U2 5 PU TRANS TECH PUBLICATIONS LTD PI DURNTEN-ZURICH PA KREUZSTRASSE 10, 8635 DURNTEN-ZURICH, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2006 VL 524-525 BP 821 EP 826 PG 6 WC Instruments & Instrumentation; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Instruments & Instrumentation; Materials Science GA BFD54 UT WOS:000241187200127 ER PT S AU Benson, ML Stoica, AD Liaw, PK Choo, H Saleh, TA Wang, XL Brown, DW Klarstrom, DL AF Benson, M. L. Stoica, A. D. Liaw, P. K. Choo, H. Saleh, T. A. Wang, X. -L Brown, D. W. Klarstrom, D. L. BE Reimers, W Quander, S TI Intergranular strain and phase transformation in a cobalt-based superalloy SO RESIDUAL STRESSES VII SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 7th European Conference on Residual Stresses (ERCS 7) CY SEP 13-15, 2006 CL Berlin, GERMANY DE cobalt-based superalloy; deformation-induced phase transformation; internal strains; Kroner model ID HIGH-CYCLE FATIGUE; ULTIMET(R) ALLOY; TEMPERATURE EVOLUTION; ELASTIC STRAIN; BEHAVIOR AB ULTIMET (R) alloy, a cobalt-based superalloy with good corrosion and wear resistant properties, exhibits a deformation-induced phase transformation from the face-centered-cubic (FCC) phase to the hexagonal-close-packed (HCP) phase. The HCP phase formation during monotonic tensile loading was investigated using in-situ neutron diffraction. The HCP phase is first observed at a stress level of 810 MPa, which is well beyond macroscopic yielding. Strain analysis is performed on the FCC phase diffraction data in order to relate the lattice-strain development with the evolution of the new HCP phase. A method of calculating the effective macroscopic stress associated with the measured lattice strains is presented here. The effective stress can then be compared to the applied macroscopic stress in order to draw conclusions about the load-partitioning behavior of the material as a new phase develops. C1 Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Spallat Neutron Source, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Los Alamos Natl Lab, Neutron Sci Ctr, Los Alamos, NM 87545 USA. Queens Univ, Dept Mech & Mat Engn, Kingston, ON K7L 3N6, Canada. Haynes Int Inc, Kokomo, IN 46904 USA. RP Benson, ML (reprint author), Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. EM mbenson2@utk.edu; stoicaad@ornl.gov; pliaw@utk.edu; hchoo@utk.edu; tsaleh@lanl.gov; wangxl@ornl.gov; dbrown@lanl.gov; dklarstrom@haynesintl.com RI Wang, Xun-Li/C-9636-2010; Choo, Hahn/A-5494-2009; Stoica, Alexandru/K-3614-2013 OI Wang, Xun-Li/0000-0003-4060-8777; Choo, Hahn/0000-0002-8006-8907; Stoica, Alexandru/0000-0001-5118-0134 NR 14 TC 3 Z9 3 U1 0 U2 4 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2006 VL 524-525 BP 893 EP 898 PG 6 WC Instruments & Instrumentation; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Instruments & Instrumentation; Materials Science GA BFD54 UT WOS:000241187200138 ER PT S AU Huber, RD Chinn, DJ Balogun, OO Murray, TW AF Huber, RD Chinn, DJ Balogun, OO Murray, TW BE Thompson, DO Chimenti, DE TI High frequency laser-based ultrasound SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 25A AND 25B SE AIP Conference Proceedings LA English DT Proceedings Paper CT 32nd Annual Review of Process in Quantitative Nondestructive Evaluation CY JUL 31-AUG 05, 2005 CL Brunswick, ME DE laser-based ultrasound ID ACOUSTIC-WAVES; GENERATION; FILMS AB To obtain micrometer resolution of materials using acoustics requires frequencies around 1 GHz. Attenuation of such frequencies is high, limiting the thickness of the parts that can be characterized. Although acoustic microscopes can operate up to several GHz in frequency, they are used primarily as a surface characterization tool. The use of a pulsed laser for acoustic generation allows generation directly in the part, eliminating the loss of energy associated with coupling the energy from a piezoelectric transducer to the part of interest. The use of pulsed laser acoustic generation in combination with optical detection is investigated for the non-contact characterization of materials with features that must be characterized to micrometer resolution. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Boston Univ, Boston, MA 02215 USA. RP Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Balogun, Oluwaseyi/B-7543-2009 NR 10 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 0-7354-0312-0 J9 AIP CONF PROC PY 2006 VL 820 BP 218 EP 224 PG 7 WC Materials Science, Characterization & Testing; Physics, Applied SC Materials Science; Physics GA BDY94 UT WOS:000236275600026 ER PT S AU Ridgway, P Russo, R Lafond, E Jackson, T Baum, GA Zhang, X AF Ridgway, P Russo, R Lafond, E Jackson, T Baum, GA Zhang, X BE Thompson, DO Chimenti, DE TI Laser ultrasonic measurement of elastic properties of moving paper: Mill demonstration SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 25A AND 25B SE AIP Conference Proceedings LA English DT Proceedings Paper CT 32nd Annual Review of Process in Quantitative Nondestructive Evaluation CY JUL 31-AUG 05, 2005 CL Brunswick, ME DE laser ultrasonic analysis; bending stiffness; industrial applications AB An automated sensor has been developed for use during paper manufacture that can measure flexural rigidity (bending stiffness). Based on laser ultrasonic technology, this sensor provides continuous noncontact on-machine measurements on paper having area densities from 35 to 205 g/m(2), moving at commercial manufacturing speeds, at any angle in the plane of the sheet. It was demonstrated on a high speed printing paper grade machine during commercial production. For that demonstration, the sensor was integrated into an existing scanning sensor system. Cross-direction profiles of flexural rigidity had the expected shape, and compared well with traditional bending stiffness measurements on samples collected for that comparison. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd MS 70-108B, Berkeley, CA 94720 USA. Georgia Tech, Inst Paper Sci & Technol, Atlanta, GA 30332 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd MS 70-108B, Berkeley, CA 94720 USA. NR 8 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 0-7354-0312-0 J9 AIP CONF PROC PY 2006 VL 820 BP 248 EP 255 PG 8 WC Materials Science, Characterization & Testing; Physics, Applied SC Materials Science; Physics GA BDY94 UT WOS:000236275600030 ER PT S AU DiMambro, J Ashbaugh, DM Han, X Favro, LD Lu, J Zeng, Z Li, W Newaz, GM Thomas, RL AF DiMambro, J Ashbaugh, DM Han, X Favro, LD Lu, J Zeng, Z Li, W Newaz, GM Thomas, RL BE Thompson, DO Chimenti, DE TI The potential of sonic IR to inspect aircraft components traditionally inspected with fluorescent penetrant and or magnetic particle inspection SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 25A AND 25B SE AIP Conference Proceedings LA English DT Proceedings Paper CT 32nd Annual Review of Process in Quantitative Nondestructive Evaluation CY JUL 31-AUG 05, 2005 CL Brunswick, ME DE sonic IR; magnetic particle; liquid penetrant; aircraft; nondestructive inspection AB Sandia National Laboratories Airworthiness Assurance Nondestructive Inspection Validation Center (AANC) provides independent and quantitative evaluations of new and enhanced inspection, to developers, users, and regulators of aircraft. Wayne State University (WSU) has developed and patented an inspection technique using high-power ultrasonic excitation and infrared technology to detect defects in a variety of materials. AANC and WSU are working together as part of the FAA Sonic Infrared Technology Transfer Program. The ultimate goal of the program is to implement Sonic IR in the aviation field where appropriate. The capability of Sonic IR imaging to detect cracks in components commonly inspected with magnetic particle or liquid penetrant inspection in the field is of interest to industry. C1 Airworthiness Assurance, Sandia Natl Labs, Albuquerque, NM 87106 USA. Wayne State Univ, Dept Phys, Detroit, MI 48202 USA. RP Airworthiness Assurance, Sandia Natl Labs, Albuquerque, NM 87106 USA. FU DOT/FAA William J. Hughes Technical Center [DTFA0300X90019-Z]; Sandia National Laboratories [DTFA0398D-00008]; Wayne State University [DTFA0300PIA037]; Institute for Manufacturing Research, Wayne State University FX This work was sponsored by DOT/FAA William J. Hughes Technical Center, under Contract Number DTFA0300X90019-Z (through Sandia National Laboratories), under Contract Number DTFA0398D-00008, Award Number DTFA0300PIA037 (through Wayne State University), and by the Institute for Manufacturing Research, Wayne State University. We thank David Galella and Paul Swindell for technical assistance and the airlines that provided components for testing. NR 4 TC 1 Z9 1 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0312-0 J9 AIP CONF PROC PY 2006 VL 820 BP 536 EP 543 PG 8 WC Materials Science, Characterization & Testing; Physics, Applied SC Materials Science; Physics GA BDY94 UT WOS:000236275600068 ER PT S AU Miyasaka, C Telschow, KL Cottle, DL AF Miyasaka, C Telschow, KL Cottle, DL BE Thompson, DO Chimenti, DE TI Laser measurement of SAM bulk and surface wave amplitudes for material microstructure analysis SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 25A AND 25B SE AIP Conference Proceedings LA English DT Proceedings Paper CT 32nd Annual Review of Process in Quantitative Nondestructive Evaluation CY JUL 31-AUG 05, 2005 CL Brunswick, ME DE laser based ultrasonics; acoustic lens; angular spectrum ID ACOUSTIC MICROSCOPY AB We present a hybrid acoustic imaging technique to directly visualize acoustic waves propagating within a thin silicon plate. A high frequency acoustic point focus lens was used to form a small point source within the plate. A laser interferometric system was used to visualize the acoustic wave propagation. Distinct amplitude patterns at each focal plane were experimentally visualized. The measured amplitude patterns exhibited the cubic symmetry of the material and the effects of focusing of the source outside and inside the material. C1 Idaho Natl Lab, Dept Phys, Idaho Falls, ID 83415 USA. RP Idaho Natl Lab, Dept Phys, Idaho Falls, ID 83415 USA. FU U.S. Department of Energy; Office Basic Energy Sciences, Materials and Engineering Physics under DOE Idaho Operations Office [DEAC07-05ID14517] FX This work was supported by U.S. Department of Energy, Office Basic Energy Sciences, Materials and Engineering Physics under DOE Idaho Operations Office Contract DEAC07- 05ID14517. The authors would like to thank Mr. Rob Schley at Idaho National Laboratory for designing and fabricating the water couplant filling apparatus. NR 10 TC 0 Z9 0 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0312-0 J9 AIP CONF PROC PY 2006 VL 820 BP 1187 EP 1192 PG 6 WC Materials Science, Characterization & Testing; Physics, Applied SC Materials Science; Physics GA BDY94 UT WOS:000236275600153 ER PT S AU Zhang, JM Sun, JG Andrews, MJ Ramesh, A Tretheway, JS Longanbach, DM AF Zhang, JM Sun, JG Andrews, MJ Ramesh, A Tretheway, JS Longanbach, DM BE Thompson, DO Chimenti, DE TI Characterization of subsurface defects in ceramic rods by laser scattering and fractography SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 25A AND 25B SE AIP Conference Proceedings LA English DT Proceedings Paper CT 32nd Annual Review of Process in Quantitative Nondestructive Evaluation CY JUL 31-AUG 05, 2005 CL Brunswick, ME DE subsurface defect; laser scattering; fractography; nondestructive evaluation; ceramics AB Silicon nitride ceramics are leading materials being evaluated for valve train components in diesel engine applications. The surface and subsurface defects and damage induced by surface machining can significantly affect component strength and lifetime. In this study, a nondestructive evaluation (NDE) technique based upon laser scattering has been utilized to analyze eight transversely ground silicon nitride cylindrical rods before fracture tests. The fracture origins (machining cracks or material-inherent flaws) identified by fractography after fracture testing were correlated with laser scattering images. The results indicate that laser scattering is able to identify possible fracture origin in the silicon nitride subsurface without the need for destructive fracture tests. C1 Kansas State Univ, Dept Ind & Mfg Syst Engn, Manhattan, KS 66506 USA. Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. Caterpillar Inc, Mossville, IL 61552 USA. RP Kansas State Univ, Dept Ind & Mfg Syst Engn, Manhattan, KS 66506 USA. FU Heavy Vehicle Propulsion Materials Program; DOE Office of FreedomCAR; Vehicle Technology Program; UT-Battelle [DE-AC05-00OR22725] FX Research sponsored by the Heavy Vehicle Propulsion Materials Program, DOE Office of FreedomCAR and Vehicle Technology Program, under contract DE-AC05-00OR22725 with UT-Battelle, LLC. NR 6 TC 0 Z9 0 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0312-0 J9 AIP CONF PROC PY 2006 VL 820 BP 1209 EP 1216 PG 8 WC Materials Science, Characterization & Testing; Physics, Applied SC Materials Science; Physics GA BDY94 UT WOS:000236275600156 ER PT S AU Spencer, FW AF Spencer, FW BE Thompson, DO Chimenti, DE TI Probability of detection estimation for hit/miss data when detection cannot be attributed to specific flaws: An exploratory data analysis SO Review of Progress in Quantitative Nondestructive Evaluation, Vols 25A and 25B SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 32nd Annual Review of Process in Quantitative Nondestructive Evaluation CY JUL 31-AUG 05, 2005 CL Brunswick, ME DE probability of detection; binary regression; hit/miss data AB Several approaches are explored to the estimation of a probability of detection curve when detection results are per "site," but the site contains multiple flaws. Binary regression is used with different candidate explanatory flaw characteristic variables including flaw sizes and number of flaws. A model treating each flaw as an independent opportunity is also introduced. The different approaches are compared and discussed in the context of estimating a POD curve using specific eddy current bolt-hole inspection data. C1 Sandia Natl Labs, Independent Surveillance Assessment & Stat, Albuquerque, NM 87185 USA. RP Spencer, FW (reprint author), Sandia Natl Labs, Independent Surveillance Assessment & Stat, POB 5800, Albuquerque, NM 87185 USA. NR 4 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 0-7354-0312-0 J9 AIP CONF PROC PY 2006 VL 820 BP 1886 EP + PG 8 WC Materials Science, Characterization & Testing; Physics, Applied SC Materials Science; Physics GA BDY94 UT WOS:000236275600243 ER PT J AU Bravenec, RV Nevins, WM AF Bravenec, RV Nevins, WM TI System for simulating fluctuation diagnostics for application to turbulence computations SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID ALCATOR-C-MOD; BEAM EMISSION-SPECTROSCOPY; DIII-D TOKAMAK; CORRELATION REFLECTOMETRY; MICROWAVE REFLECTOMETRY; DENSITY-FLUCTUATIONS; PLASMA; TRANSPORT; CONFINEMENT; PROBE AB Present-day nonlinear microstability codes are able to compute the saturated fluctuations of a turbulent fluid versus space and time, whether the fluid be liquid, gas, or plasma. They are therefore able to determine turbulence-induced fluid (or particle) and energy fluxes. These codes, however, must be tested against experimental data not only with respect to transport but also characteristics of the fluctuations. The latter is challenging because of limitations in the diagnostics (e.g., finite spatial resolution) and the fact that the diagnostics typically do not measure exactly the quantities that the codes compute. In this work, we present a system based on IDL (R) analysis and visualization software in which user-supplied "diagnostic filters" are applied to the code outputs to generate simulated diagnostic signals. The same analysis techniques as applied to the measurements, e.g., digital time-series analysis, may then be applied to the synthesized signals. Their statistical properties, such as rms fluctuation level, mean wave numbers, phase and group velocities, correlation lengths and times, and in some cases full S(k,omega) spectra, can then be compared directly to those of the measurements. (c) 2006 American Institute of Physics. C1 Univ Texas, Fus Res Ctr, Austin, TX 78712 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Bravenec, RV (reprint author), Univ Texas, Fus Res Ctr, 1 Univ Stn,C1510, Austin, TX 78712 USA. NR 38 TC 19 Z9 19 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JAN PY 2006 VL 77 IS 1 AR 015101 DI 10.1063/1.2151857 PG 10 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 007OQ UT WOS:000234979400028 ER PT J AU Johnson, GE Dauble, DD AF Johnson, Gary E. Dauble, Dennis D. TI Surface flow outlets to protect juvenile salmonids passing through hydropower dams SO REVIEWS IN FISHERIES SCIENCE LA English DT Article DE juvenile fish passage; fish protection; surface bypasses; sluiceways ID LOWER GRANITE DAM; SNAKE RIVER; CHINOOK SALMON; COLUMBIA RIVER; BYPASS SYSTEM; WELLS DAM; WASHINGTON; SMOLTS; EFFICIENCY; STEELHEAD AB We reviewed results of research conducted by engineers and biologists over the past 50 years related to development of surface flow outlets (SFOs) for juvenile salmonids that migrate downstream past hydropower dams. An SFO is a nonturbine, water-efficient passage route with an overflow structure through which flow and fish pass over a dam. Our review covered 69 SFOs in Europe and North America. We identified five main types of SFOs-low-flow bypass/sluices, high-flow sluices, forebay collectors, powerhouse retrofits, and surface spills. Most low-flow bypass/sluices are sited in Europe and on the east coast of North America, where mean annual project discharge and power production were 95 mf/s and 15 MW, respectively. The other four SFO types are found on the west coast of North America with 2184 m(3)/s mean annual discharge and 788 MW mean power output. A conceptual framework based on fish behavior and hydraulics for different regions of a hydropower project was developed to evaluate SFO performance. Based on available data, fish collection efficiency averaged 53%, with an average effectiveness ratio of 17:1 (percentage of fish collected and passed to percentage of inflow used for SFO attraction). Surface flow outlet technology can meet the goal of concurrent anadromous fish protection and hydropower generation. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Johnson, GE (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. EM gary.johnson@pnl.gov NR 93 TC 23 Z9 24 U1 3 U2 28 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1064-1262 J9 REV FISH SCI JI Rev. Fish. Sci. PY 2006 VL 14 IS 3 BP 213 EP 244 DI 10.1080/10641260600864023 PG 32 WC Fisheries SC Fisheries GA 091DQ UT WOS:000241006900001 ER PT J AU Bader, SD AF Bader, SD TI Colloquium: Opportunities in nanomagnetism SO REVIEWS OF MODERN PHYSICS LA English DT Review ID PERMANENT-MAGNET MATERIALS; EXCHANGE-SPRING MAGNETS; MESOSCOPIC SPIN-VALVE; FEPT NANOPARTICLES; ROOM-TEMPERATURE; MAGNETIZATION REVERSAL; MATERIALS CHEMISTRY; SELF-ORGANIZATION; BLOCK-COPOLYMERS; TRANSISTOR AB Nanomagnetism is the discipline dealing with magnetic phenomena specific to structures having dimensions in the submicron range. This Colloquium addresses the challenges and scientific problems in this emerging area, including its fabrication strategies, and describes experiments that explore new spin-related behaviors in metallic systems as well as theoretical efforts to understand the observed phenomena. As a subfield of nanoscience, nanomagnetism shares many of the same basic organizing principles such as geometric confinement, physical proximity, and chemical self-organization. These principles are illustrated by means of several examples drawn from the quests for ultrastrong permanent magnets, ultra-high-density magnetic recording media, and nanobiomagnetic sensing strategies. As a final example showing the synergetic relationships to other fields of science, this Colloquium discusses the manipulation of viruses to fabricate magnetic nanoparticles. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Ctr Nanoscale Mat, Argonne, IL 60439 USA. RP Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Bader, Samuel/A-2995-2013 NR 103 TC 437 Z9 442 U1 13 U2 143 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0034-6861 EI 1539-0756 J9 REV MOD PHYS JI Rev. Mod. Phys. PD JAN-MAR PY 2006 VL 78 IS 1 BP 1 EP 15 DI 10.1103/RevModPhys.78.1 PG 15 WC Physics, Multidisciplinary SC Physics GA 028VG UT WOS:000236516300001 ER PT J AU Ashbaugh, HS Pratt, LR AF Ashbaugh, HS Pratt, LR TI Colloquium: Scaled particle theory and the length scales of hydrophobicity SO REVIEWS OF MODERN PHYSICS LA English DT Review ID SOLVATION FREE-ENERGIES; TEMPERATURE-DEPENDENCE; SURFACE-TENSION; STATISTICAL-MECHANICS; PROTEIN DENATURATION; ENTROPY CONVERGENCE; COMPUTER-SIMULATION; MOLECULAR-DYNAMICS; ATTRACTIVE FORCES; AQUEOUS SOLUTIONS AB Hydrophobic hydration plays a crucial role in self-assembly processes over multiple length scales, from the microscopic origins of inert gas solubility in water, to the mesoscopic organization of proteins and surfactant structures, to macroscopic phase separation. Many theoretical studies focus on the molecularly detailed interactions between oil and water, but the extrapolation of molecular-scale models to larger-length-scale hydration phenomena is sometimes not warranted. Scaled particle theories are based upon an interpolative view of that microscopic <-> macroscopic issue. This Colloquium revisits the scaled particle theory proposed 30 years ago by Stillinger [J. Solution Chem. 2, 141 (1973)], adopts a practical generalization, and considers the implications for hydrophobic hydration in light of our current understanding. The generalization is based upon identifying a molecular length, implicit in previous applications of scaled particle models, which provides an effective radius for joining microscopic and macroscopic descriptions. It will be demonstrated that the generalized theory correctly reproduces many of the anomalous thermodynamic properties of hydrophobic hydration for molecularly sized solutes, including solubility minima and entropy convergence, successfully interpolates between the microscopic and macroscopic extremes, and provides new insights into the underlying molecular mechanisms. The model considered here serves as a reference for theories that bridge microscopic and macroscopic hydrophobic effects. The results are discussed in terms of length scales associated with component phenomena. In particular, first there is a discussion of the microscopic-macroscopic joining radius identified by the theory; then follows a discussion of the Tolman length that describes curvature corrections to a surface area model of hydrophobic hydration free energies and the length scales on which entropy convergence of hydration free energies are expected. C1 Tulane Univ, Dept Chem & Biomol Engn, New Orleans, LA 70118 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Ashbaugh, HS (reprint author), Tulane Univ, Dept Chem & Biomol Engn, New Orleans, LA 70118 USA. RI Pratt, Lawrence/H-7955-2012; Ashbaugh, Henry/C-9767-2011 OI Pratt, Lawrence/0000-0003-2351-7451; NR 120 TC 233 Z9 236 U1 10 U2 92 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0034-6861 J9 REV MOD PHYS JI Rev. Mod. Phys. PD JAN-MAR PY 2006 VL 78 IS 1 BP 159 EP 178 DI 10.1103/RevModPhys.78.159 PG 20 WC Physics, Multidisciplinary SC Physics GA 028VG UT WOS:000236516300005 ER PT J AU Padilla-Rodal, E Castanos, O Bijker, R Galindo-Uribarri, A AF Padilla-Rodal, E. Castanos, O. Bijker, R. Galindo-Uribarri, A. TI IBM-2 configuration mixing and it's geometric interpretation for germanium isotopes SO REVISTA MEXICANA DE FISICA LA English DT Article; Proceedings Paper CT 28th Symposium on Nuclear Physics CY JAN 04-07, 2005 CL Hacienda Cocoyoc, MEXICO ID INTERACTING BOSON MODEL; GE ISOTOPES; SHAPE COEXISTENCE; NUCLEI; TRANSITION; SPECTRA AB The low energy spectra, electric quadrupole transitions, and quadrupole moments for the germanium isotopes ate determined in the formalism of the IBM-2 with configuration Mixing. These calculated observables reproduce Well the available experimental information including the newly obtained data for radioactive neutron-rich Ge-78,Ge-80,Ge-82 isotopes. Using a matrix formulation, a geometric interpretation of the model was established. the two energy surfaces determined after mixing, carry information about the deformation parameters of the nucleus. For the even-even Ge isotopes the obtained results are Consistent With the shape transition that takes place around the neutron number N = 40. C1 Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Mexico City 04510, DF, Mexico. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RP Padilla-Rodal, E (reprint author), Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Mexico City 04510, DF, Mexico. NR 19 TC 6 Z9 6 U1 1 U2 2 PU SOCIEDAD MEXICANA DE FISICA PI COYOACAN PA APARTADO POSTAL 70-348, COYOACAN 04511, MEXICO SN 0035-001X J9 REV MEX FIS JI Rev. Mex. Fis. PD JAN PY 2006 VL 52 IS 1 SU S BP 57 EP 62 PG 6 WC Physics, Multidisciplinary SC Physics GA 142LK UT WOS:000244651200012 ER PT J AU Bearden, IG Beavis, D Besliu, C Budick, B Boggild, H Chasman, C Christensen, CH Christiansen, P Cibor, J Debbe, R Enger, E Gaardhoje, JJ Germinario, M Hagel, K Hansen, O Holm, A Holme, AK Ito, H Jipa, A Jundt, F Jorde, JI Jorgensen, CE Karabowicz, R Kim, EJ Kozik, T Larsen, TM Lee, JH Lee, YK Lovhoiden, G Majka, Z Makeev, A Mikelsen, M Murray, M Natowitz, J Nielsen, BS Norris, J Olchanski, K Ouerdane, D Planeta, R Rami, F Ristea, C Rohrich, D Samset, BH Sandberg, D Sanders, SJ Scheetz, RA Staszel, P Tveter, TS Videbaek, F Wada, R Yin, Z Zgura, IS AF Bearden, I. G. Beavis, D. Besliu, C. Budick, B. Boggild, H. Chasman, C. Christensen, C. H. Christiansen, P. Cibor, J. Debbe, R. Enger, E. Gaardhoje, J. J. Germinario, M. Hagel, K. Hansen, O. Holm, A. Holme, A. K. Ito, H. Jipa, A. Jundt, F. Jorde, J. I. Jorgensen, C. E. Karabowicz, R. Kim, E. J. Kozik, T. Larsen, T. M. Lee, J. H. Lee, Y. K. Lovhoiden, G. Majka, Z. Makeev, A. Mikelsen, M. Murray, M. Natowitz, J. Nielsen, B. S. Norris, J. Olchanski, K. Ouerdane, D. Planeta, R. Rami, F. Ristea, C. Rohrich, D. Samset, B. H. Sandberg, D. Sanders, S. J. Scheetz, R. A. Staszel, P. Tveter, T. S. Videbaek, F. Wada, R. Yin, Z. Zgura, I. S. TI Forward rapidity results from RHIC SO REVISTA MEXICANA DE FISICA LA English DT Article; Proceedings Paper CT 28th Symposium on Nuclear Physics CY JAN 04-07, 2005 CL Hacienda Cocoyoc, MEXICO DE quark chemistry; rapidity density; stopping; high pt suppression ID COLOR GLASS CONDENSATE; NUCLEUS-NUCLEUS COLLISIONS; QUARK-GLUON-PLASMA; PLUS AU COLLISIONS; PARTICLE; EVOLUTION; FLOW AB A summary of BRAHMS results is presented. Emphasis is placed on data for which measurements at forward rapidities are necessary for interpretation. This includes measurements of spectra over a wide range of y and transverse momentum, yields, stopping, quark chemistry and high p(t) Suppression in both Au+Au and d+Au collisions at root SNN = 200 GeV. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Inst Rech Subatom, Strasbourg, France. Univ Strasbourg 1, Strasbourg, France. Inst Nucl Phys, Krakow, Poland. Jagiellonian Univ, Smoluchkowski Inst Phys, PL-31007 Krakow, Poland. Johns Hopkins Univ, Baltimore, MD 21218 USA. NYU, New York, NY 10003 USA. Univ Copenhagen, Niels Bohr Inst, DK-2100 Copenhagen, Denmark. Texas A&M Univ, College Stn, TX 77843 USA. Univ Bergen, Dept Phys, N-5020 Bergen, Norway. Univ Bucharest, Bucharest, Romania. Univ Kansas, Lawrence, KS 66045 USA. Univ Oslo, Dept Phys, N-0316 Oslo, Norway. RP Bearden, IG (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. RI Christensen, Christian Holm/A-4901-2010; Christensen, Christian/D-6461-2012; Bearden, Ian/M-4504-2014; Samset, Bjorn H./B-9248-2012 OI Christensen, Christian Holm/0000-0002-1850-0121; Christensen, Christian/0000-0002-1850-0121; Bearden, Ian/0000-0003-2784-3094; Samset, Bjorn H./0000-0001-8013-1833 NR 40 TC 0 Z9 0 U1 0 U2 1 PU SOCIEDAD MEXICANA DE FISICA PI COYOACAN PA APARTADO POSTAL 70-348, COYOACAN 04511, MEXICO SN 0035-001X J9 REV MEX FIS JI Rev. Mex. Fis. PD JAN PY 2006 VL 52 IS 1 SU S BP 112 EP 118 PG 7 WC Physics, Multidisciplinary SC Physics GA 142LK UT WOS:000244651200020 ER PT S AU Plum, MM Beitel, GA AF Plum, M. M. Beitel, G. A. BE Brebbia, CA Popov, V TI Rationale and development of a Security Assurance Index with application toward the development of a World Risk Index SO Risk Analysis V: Simulation and Hazard Mitigation SE WIT TRANSACTIONS ON ECOLOGY AND THE ENVIRONMENT LA English DT Proceedings Paper CT 5th International Conference on Simulation in Risk Analysis and Hazard Mitigation CY JUN 19-21, 2006 CL MALTA SP Wessex Inst Technol, WIT Transact Ecol & Environm DE World Risk Index; Security Assurance; risk management; risk scale AB Assurance categories were previously developed to support the Department of Homeland Security's efforts in the mitigation of Cyber Control System events. Defined according to the risk of life and economic loss, the minimum range is designated by policy; whereas, the maximum limit seems to be constrained only by limits and interdependencies of the event. Use of this life/assets scale has proven to be helpful in managing risk due to the scales ease in use, communication, and understanding. Suggestions have been made that this scale could be applied to all events of terror, disaster, and calamity of an international scale, with equally good results. This paper will present the history of some existing scales of disaster and assurance, the rationale behind the development of the original Security Assurance Index, and our proposed scale of disaster and calamity as a World Risk Index. C1 Idaho Natl Lab, Idaho Falls, ID 83415 USA. RP Plum, MM (reprint author), Idaho Natl Lab, Idaho Falls, ID 83415 USA. NR 4 TC 0 Z9 0 U1 1 U2 1 PU WIT PRESS/COMPUTATIONAL MECHANICS PUBLICATIONS PI SOUTHAMPTON PA ASHURST LODGE, ASHURST, SOUTHAMPTON SO40 7AA, ENGLAND SN 1746-448X BN 1-84564-172-8 J9 WIT TRANS ECOL ENVIR PY 2006 VL 91 BP 325 EP 340 DI 10.2495/RISK060311 PG 16 WC Engineering, Multidisciplinary SC Engineering GA BEU29 UT WOS:000239520600031 ER PT S AU Constantz, J Su, GW Hatch, C AF Constantz, J Su, GW Hatch, C BE Hubbs, SA TI Heat as a ground-water tracer at the Russian River RBF facility, Sonoma County, California SO RIVERBANK FILTRATION HYDROLOGY SE NATO Science Series IV-Earth and Environmental Sciences LA English DT Proceedings Paper CT NATO Advanced Reseaech Workshop on Riverbank Filtration Hydrology CY SEP, 2004 CL Bratislava, SLOVAKIA SP NATO, Public Diplomacy Div DE heat; temperature; water levels; hydraulic conductivity; infiltration; streambed clogging ID TEMPERATURE-DEPTH PROFILES; STREAMFLOW; DURATION; BENEATH AB Temperature is routinely collected as a water quality parameter, but only recently utilized as an environmental tracer of stream exchanges with ground water (Stonestrom and Constantz, 2003). In this paper, water levels and seasonal temperatures were used to estimate streambed hydraulic conductivities and water fluxes. Temperatures and water levels were analyzed from 3 observation wells near the Russian River RBF facility, north of Forestville, Sonoma County, CA. In addition, 9 shallow piezometers were installed in 3 cross-sections across the stream near a pair of collector wells at the RBF facility. Hydraulic conductivities and fluxes were estimated by matching simulated ground-water temperatures to the observed ground-water temperatures with an inverse modeling approach. Using temperature measurements in the shallow piezometers from 0.1 to 1.0 m below the channel, estimates of infiltration indicated a distinct area of streambed clogging near one of the RBF collector wells. For the deeper observation wells, temperature probes were located at depths between 3.5 m to 7.1 m below the channel. Estimated conductivities varied over an order of magnitude, with anisotropies of 5 (horizontal to vertical hydraulic conductivity) generally providing the best fit to observed temperatures. C1 US Geol Survey, 345 Middlefield Rd, Menlo Pk, CA 94025 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif, Santa Cruz, CA 95064 USA. RP US Geol Survey, 345 Middlefield Rd, Menlo Pk, CA 94025 USA. NR 20 TC 3 Z9 3 U1 1 U2 8 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 1568-1238 BN 1-4020-3936-0 J9 NATO SCI S SS IV EAR JI NATO Sci. Series IV Earth Environ. Sciences PY 2006 VL 60 BP 243 EP + PG 3 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA BDZ48 UT WOS:000236349900011 ER PT J AU Brodsky, SJ AF Brodsky, S. J. TI Testing quantum chromodynamics with antiprotons SO RIVISTA DEL NUOVO CIMENTO LA English DT Reprint ID ELECTROMAGNETIC FORM-FACTORS; VIRTUAL COMPTON-SCATTERING; LARGE-MOMENTUM-TRANSFER; DRELL-YAN PROCESS; DEEP-INELASTIC SCATTERING; SINGLE-SPIN ASYMMETRIES; ELECTRON-POSITRON ANNIHILATION; WAVE-FUNCTION REPRESENTATION; INITIAL-STATE INTERACTIONS; LIGHT-FRONT DYNAMICS C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Brodsky, SJ (reprint author), Int Sch Phys Enrico Fermi, Bologna, Italy. NR 319 TC 0 Z9 0 U1 0 U2 1 PU SOC ITALIANA FISICA PI BOLOGNA PA VIA SARAGOZZA, 12, I-40123 BOLOGNA, ITALY SN 0393-697X J9 RIV NUOVO CIMENTO JI Riv. Nuovo Cimento PY 2006 VL 29 IS 9 BP 1 EP 71 DI 10.1393/ncr/i2007-10014-x PG 71 WC Physics, Multidisciplinary SC Physics GA 223DS UT WOS:000250350400001 ER PT B AU Lauterbach, C Yoon, SE Tuft, D Manocha, D AF Lauterbach, Christian Yoon, Sung-Eui Tuft, David Manocha, Dinesh BE Wald, I Parker, SG TI RT-DEFORM: Interactive ray tracing of dynamic scenes using BVHs SO RT 06: IEEE SYMPOSIUM ON INTERACTIVE RAY TRACING 2006, PROCEEDINGS LA English DT Proceedings Paper CT IEEE Symposium on Interactive Ray Tracing 2006 CY SEP 18-20, 2006 CL Salt Lake City, UT SP IEEE, IEEE Comp Soc, IEEE VGTC DE ray tracing; bounding volume hierarchies; deformable models; animation ID HIERARCHIES AB We present an efficient approach for interactive ray tracing of deformable or animated models. Unlike many of the recent approaches for ray tracing static scenes, we use bounding volume hierarchies (BVHs) instead of kd-trees as the underlying acceleration structure. Our algorithm makes no assumptions about the simulation or the motion of objects in the scene and dynamically updates or recomputes the BVHs. We also describe a method to detect BVH quality degradation during the simulation in order to determine when the hierarchy needs to be rebuilt. Furthermore, we show that the ray coherence techniques introduced for kd-trees can be naturally extended to BVHs and yield similar improvements. Finally, we compare BVHs to spatial kd-trees, which have been used recently as a replacement for AABB hierarchies. Our algorithm has been applied to different scenarios arising in animation and simulation and consisting of tens of thousands to a million triangles. In practice, our system can ray trace these models at 3-13 frames a second on a desktop PC including secondary rays. C1 [Lauterbach, Christian; Tuft, David; Manocha, Dinesh] Univ N Carolina, Chapel Hill, NC 27599 USA. [Yoon, Sung-Eui] Lawrence Livermore Natl Lab, Lawrence, KS USA. RP Lauterbach, C (reprint author), Univ N Carolina, Chapel Hill, NC 27599 USA. EM cl@cs.unc.edu; sungeui@llnl.gov; tuft@cs.unc.edu; dm@cs.unc.edu FU ARO [DAAD19-02-1-0390, W911NF-04-1-0088]; NSF [0400134, 0118743]; ONR [N00014-01-1- 0496]; DARP A/RDECOM [N61339-04-C-0043]; Intel; LOCAL LLNL LDRD project [05-ERD-018]; Univer-sity of California; Lawrence Livermore National Laboratory [W -7405-Eng-48] FX Part of this work was performed while the primary author was working at Intel corporation. W e w ould lik e to thank Ingo W ald, Ale xander Resheto v , Gordon Stoll and UNC' s GAMMA group for helpful discussions and feedback, as well as the anon ymous re- vie wers for their comments. The model used for the dress sim- ulation is courtesy of W alt Disne y Feature Animation and the Bunn y and Buddha models are courtesy of the 3D scanning repos- itory at Stanford Uni v ersity . This work was supported in part by ARO Contracts DAAD19-02-1-0390 and W911NF-04-1-0088, NSF awards 0400134 and 0118743, ONR Contract N00014-01-1- 0496, DARP A/RDECOM Contract N61339-04-C-0043, Intel, and LOCAL LLNL LDRD project (05-ERD-018) and was performed under the auspices of the U.S. Department of Energy by the Univer-sity of California, Lawrence Livermore National Laboratory under Contract No. W -7405-Eng-48 NR 43 TC 9 Z9 10 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4244-0693-7 PY 2006 BP 39 EP + PG 4 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Imaging Science & Photographic Technology SC Computer Science; Imaging Science & Photographic Technology GA BFW76 UT WOS:000245159000006 ER PT J AU Glasser, AH Liseikin, VD Vaseva, IA Likhanova, YV AF Glasser, A. H. Liseikin, V. D. Vaseva, I. A. Likhanova, Yu. V. TI Some computational aspects on generating numerical grids SO RUSSIAN JOURNAL OF NUMERICAL ANALYSIS AND MATHEMATICAL MODELLING LA English DT Article ID EQUIDISTRIBUTION AB An elliptic method based on the application of both Beltrami and diffusion equations in monitor metrics is developed for generating adaptive and/or magnetic vector field-aligned grids. Some results of numerical experiments for constructing two- and three-dimensional grids are demonstrated. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Russian Acad Sci, Siberian Branch, Inst Computat Technol, Novosibirsk 630090, Russia. RP Glasser, AH (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 22 TC 1 Z9 1 U1 1 U2 1 PU VSP BV PI LEIDEN PA BRILL ACADEMIC PUBLISHERS, PO BOX 9000, 2300 PA LEIDEN, NETHERLANDS SN 0927-6467 J9 RUSS J NUMER ANAL M JI Russ. J. Numer. Anal. Math. Model PY 2006 VL 21 IS 6 BP 481 EP 505 DI 10.1515/rnam.2006.21.6.481 PG 25 WC Engineering, Multidisciplinary; Mathematics, Applied SC Engineering; Mathematics GA 118IP UT WOS:000242936200001 ER PT S AU Srinivasan, R Cook, J Lubeck, O AF Srinivasan, Ram Cook, Jeanine Lubeck, Olaf BE DeSouza, AF Buyya, R Meira, W TI Ultra-fast CPU performance prediction: Extending the Monte Carlo approach SO SBAC-OAD 2006: 18TH INTERNATIONAL SYMPOSIUM ON COMPUTER ARCHITECTURE AND HIGH PERFORMANCE COMPUTING SE International Symposium on Computer Architecture and High Performance Computing LA English DT Proceedings Paper CT 18th International Symposium on Computer Architecture and High Performance Computing CY OCT 17-20, 2006 CL Ouro Preto, BRAZIL SP Brazilian Comp Soc, IEEE Comp Soc, TCCA - TCSC, IFIP Working Grp 10 3, Univ Fed Minas Gerais, Univ Fed Ouro Preto, Pontificia Univ Catol Minas Gerais, Univ Fed Espirito Santo, Univ Melbourne AB Performance evaluation of contemporary processors is becoming increasingly difficult due to the lack of proper frameworks. Traditionally, cycle-accurate simulators have been extensively used due to their inherent accuracy and flexibility. However the effort involved in building them, their slow speed, and their limited ability to provide insight often imposes constraints on the extent of design exploration. In this paper we refine our earlier Monte Carlo based CPI prediction model [11] to include software assisted data-prefetching and an improved memory model. Software-based prefetching is becoming an increasingly important feature in modern processors but to the best of our knowledge, existing frameworks do not model it. Our model uses micro-architecture independent application characteristics to predict CPI with an average error of less than 10% when vaidated against the Itanium-2 processor. Besides accurate performance prediction, we illustrate the applications of the model to processor bottle-neck analysis, workload characterization and design space exploration. C1 [Srinivasan, Ram; Cook, Jeanine; Lubeck, Olaf] New Mexico State Univ, Los Alamos Natl Lab, Las Cruces, NM 88003 USA. RP Srinivasan, R (reprint author), New Mexico State Univ, Los Alamos Natl Lab, Las Cruces, NM 88003 USA. EM ram@nmsu.edu; jcook@nmsu.edu; olubeck@lanl.gov FU DARPA High Productivity Computing Systems FX This work is funded in part by the DARPA High Productivity Computing Systems program and by an equipmentgrant from HP NR 8 TC 1 Z9 1 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA SN 1550-6533 BN 0-7695-2704-3 J9 INT SYM COMP ARCHIT PY 2006 BP 107 EP + PG 2 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BFL07 UT WOS:000242568800013 ER PT S AU Bell, J Dayl, M Almgren, A Lijewski, M Rendleman, C Cheng, R Shepherd, I AF Bell, J. Dayl, M. Almgren, A. Lijewski, M. Rendleman, C. Cheng, R. Shepherd, I. BE Tang, WM TI Simulation of lean premixed turbulent combustion SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID NAVIER-STOKES EQUATIONS; ADAPTIVE MESH REFINEMENT; 2ND-ORDER PROJECTION METHOD; FLAME-FRONT STRUCTURE; NUMERICAL-SIMULATION; BURNING RATE; AIR FLAMES; CHEMISTRY; FLOWS; OBSERVABLES AB There is considerable technological interest in developing new fuel-flexible combustion systems that can burn fuels such as hydrogen or syngas. Lean premixed systems have the potential to burn these types of fuels with high efficiency and low NOx emissions due to reduced burnt gas temperatures. Although traditional scientific approaches based on theory and laboratory experiment have played essential roles in developing our current understanding of premixed combustion, they are unable to meet the challenges of designing fuel-flexible lean premixed combustion devices. Computation, with its ability to deal with complexity and its unlimited access to data, has the potential for addressing these challenges. Realizing this potential requires the ability to perform high fidelity simulations of turbulent lean premixed flames under realistic conditions. In this paper, we examine the specialized mathematical structure of these combustion problems and discuss simulation approaches that exploit this structure. Using these ideas we can dramatically reduce computational cost, making it possible to perform high-fidelity simulations of realistic flames. We illustrate this methodology by considering ultra-lean hydrogen flames and discuss how this type of simulation is changing the way researchers study combustion. C1 [Bell, J.; Dayl, M.; Almgren, A.; Lijewski, M.; Rendleman, C.] Lawrence Berkeley Natl Lab, CCSE, Berkeley, CA 94720 USA. [Cheng, R.; Shepherd, I.] Lawrence Berkeley Natl Lab, EETD, Berkeley, CA 94720 USA. RP Bell, J (reprint author), Lawrence Berkeley Natl Lab, CCSE, Berkeley, CA 94720 USA. EM jbbell@lbl.gov FU DOE Office of Science through the SciDAC program by the Office of Advanced Scientific Computing Research, Mathematical, Information, and Computational Sciences Division FX Computations were performed at the National Energy Research Scientific Computing Center, at the National Center for Computational Sciences and at the NASA Columbia. This work was supported by the DOE Office of Science through the SciDAC program by the Office of Advanced Scientific Computing Research, Mathematical, Information, and Computational Sciences Division. NR 41 TC 5 Z9 5 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 1 EP 15 DI 10.1088/1742-6596/46/1/001 PG 15 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300001 ER PT S AU Oefelein, JC Drozda, TG Sankaran, V AF Oefelein, J. C. Drozda, T. G. Sankaran, V. BE Tang, WM TI Large eddy simulation of turbulence-chemistry interactions in reacting flows SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID FILTERED DENSITY-FUNCTION; CONDITIONAL MOMENT CLOSURE; SUBGRID-SCALE MODEL; SANDIA FLAME-D; CORRESPONDING STATES; TRANSPORT-PROPERTIES; PARTICLE-LADEN; CHANNEL FLOW; COMBUSTION; DIFFUSION AB Application of the Large Eddy Simulation (LES) technique provides the formal ability to treat the wide range of multidimensional time and length scales that exist in turbulent reacting flows in a computationally feasible manner. The large energetic-scales are resolved directly. The small "subgrid-scales" are modeled. This allows simulation of the complex multiple-time multiple-length scale coupling between processes in a time-accurate manner. Treating the full range of scales is a critical requirement since turbulent processes are inherently coupled through a cascade of nonlinear interactions. This paper provides a perspective on LES and its application to turbulent combustion. In particular, the combination of LES, high-performance massively-parallel computing, and advanced experimental capabilities in combustion science offer unprecedented opportunities for synergistic high-fidelity investigations. Information from well-defined benchmark flames, using a combination of state-of-the-art experiments and detailed simulations that match the experimental conditions, present new opportunities to understand the central physics of turbulence-chemistry interactions. Understanding these fundamental physical processes, and developing advanced simulation capabilities that efficiently and accurately describe them, are crucial requirements for the development of next generation combustion systems. Results are shown that demonstrate the progression toward more complex systems, with emphasis placed on the fundamental issues of turbulence-chemistry interactions. C1 [Oefelein, J. C.; Drozda, T. G.; Sankaran, V.] Sandia Natl Labs, Combust Res Facil, POB 969, Livermore, CA 94551 USA. RP Oefelein, JC (reprint author), Sandia Natl Labs, Combust Res Facil, POB 969, Livermore, CA 94551 USA. EM oefelei@sandia.gov FU United States Department of Energy [DE-AC04-94-AL85000] FX The U. S. Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences supported this work. Sandia National Laboratories is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94-AL85000. NR 68 TC 1 Z9 1 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 16 EP 27 DI 10.1088/1742-6596/46/1/002 PG 12 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300002 ER PT S AU Sankaran, R Hawkes, ER Chen, JH Lu, TF Law, CK AF Sankaran, Ramanan Hawkes, Evatt R. Chen, Jacqueline H. Lu, Tianfeng Law, Chung K. BE Tang, WM TI Direct numerical simulations of turbulent lean premixed combustion SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID BOUNDARY-CONDITIONS; FLAMES; FLOWS AB In recent years; due to the advent of high-performance computers and advanced numerical algorithms, direct numerical simulation (DNS) of combustion has emerged as a valuable computational research tool, in concert with experimentation. The role of DNS in delivering new scientific insight into turbulent combustion is illustrated using results from a recent 3D turbulent premixed flame simulation. To understand the influence of turbulence on the flame structure; a 3D fully-resolved DNS of a spatially-developing lean methane-air turbulent Bunsen flame was performed in the thin reaction zones regime. A reduced chemical model for methane-air chemistry consisting of 13 resolved species, 4 quasi-steady state species and 73 elementary reactions was developed specifically for the current simulation. The data is analyzed to study possible influences of turbulence on the flame thickness. The results show that the average flame thickness increases, in qualitative agreement with several experimental results. C1 [Sankaran, Ramanan; Hawkes, Evatt R.; Chen, Jacqueline H.] Sandia Natl Labs, Livermore, CA 94551 USA. [Lu, Tianfeng; Law, Chung K.] Princeton Univ, Princeton, NJ 08544 USA. RP Sankaran, R (reprint author), Sandia Natl Labs, Livermore, CA 94551 USA. EM jhchen@sandia.gov RI Sankaran, Ramanan/D-9254-2015; Hawkes, Evatt/C-5307-2012 OI Sankaran, Ramanan/0000-0002-5352-9915; Hawkes, Evatt/0000-0003-0539-7951 FU Division of Chemical Sciences, Geosciences and Biosciences; Office of Basic Energy Sciences (BES); U.S. Department of Energy (DOE); U.S. DOE; BES; SciDAC Computational Chemistry program; U.S. DOE [DE-AC04-94-AL85000, DE-AC05-00OR22725]; Air Force Office of Scientific Research FX The work at SNL was supported by the Division of Chemical Sciences, Geosciences and Biosciences, the Office of Basic Energy Sciences (BES), the U.S. Department of Energy (DOE) and also by the U.S. DOE, BES, SciDAC Computational Chemistry program. SNL is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the U.S. DOE under contract DE-AC04-94-AL85000. The work at Princeton was supported by the Air Force Office of Scientific Research under the technical monitoring of Dr. Julian M. Tishkoff. This research used resources of the National Center for Computational Sciences (NCCS) at Oak Ridge National Laboratory (ORNL), which is supported by the Office of Science of the U.S. DOE under Contract No. DE-AC05-00OR22725. We are grateful to Mark R. Fahey of NCCS/ORNL for his computing support. NR 16 TC 23 Z9 23 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 38 EP 42 DI 10.1088/1742-6596/46/1/004 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300004 ER PT S AU Day, M Bell, J AF Day, M. Bell, J. BE Tang, WM TI Simulation of premixed turbulent flames SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID NUMERICAL-SIMULATION C1 [Day, M.; Bell, J.] Lawrence Berkeley Natl Lab, Ctr Computat Sci & Engn, Berkeley, CA 94720 USA. RP Day, M (reprint author), Lawrence Berkeley Natl Lab, Ctr Computat Sci & Engn, Berkeley, CA 94720 USA. EM MSDay@lbl.gov FU DOE Office of Mathematics, Information, and Computational Sciences [DE-AC02-05CH11231] FX This work was supported by the SciDAC Program of the DOE Office of Mathematics, Information, and Computational Sciences under contract No. DE-AC02-05CH11231. Simulations of the V-flame were carried out in collaboration with Robert Chang and Ian Shepherd at LBNL. The Bunsen flame simulations were carried out in collaboration with Jim Driscoll (University of Michigan) and Sergei Filatyev (Purdue University). All simulations presented were run on the NERSC Bassi machine at Lawrence Berkeley National Laboratory. NR 9 TC 1 Z9 1 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 43 EP 47 DI 10.1088/1742-6596/46/1/005 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300005 ER PT S AU Najm, HN Ray, J Valorani, M Creta, F Goussis, DA AF Najm, H. N. Ray, J. Valorani, M. Creta, F. Goussis, D. A. BE Tang, WM TI A computational facility for reacting flow science SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID REFINEMENT; CHEMISTRY; SYSTEMS; MODELS; RKC AB We discuss recent developments in the application of high-order adaptive mesh refinement constructions in reacting flow computations. We present results pertaining to the time integration of coupled diffusive-convective terms in this context using a stabilized explicit Runge-Kutta-Chebyshev scheme. We also discuss chemical model reduction strategies, with a focus on the utilization of computational singular perturbation theory for generation of simplified chemical models. Starting from a detailed chemical mechanism for methane-air combustion, we examine a posteriori errors in flame species computed with a range of simplified mechanisms corresponding to a varying degree of model reduction. C1 [Najm, H. N.; Ray, J.] Sandia Natl Labs, Livermore, CA 94550 USA. [Valorani, M.; Creta, F.] Univ Roma La Sapienza, I-00185 Rome, Italy. RP Najm, HN (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. EM hnnajm@sandia.gov OI CRETA, Francesco/0000-0003-1923-0810; VALORANI, Mauro/0000-0002-8260-6297 FU US Department of Energy (DOE) [DE-AC04-94-AL85000]; Office of Basic Energy Sciences (BES); Italian Ministry of University and Research (MIUR); SciDAC Computational Chemistry Program; DOE BES Division of Chemical Sciences, Geosciences, and Biosciences FX This work was supported by the US Department of Energy (DOE), Office of Basic Energy Sciences (BES), SciDAC Computational Chemistry Program; and by the DOE BES Division of Chemical Sciences, Geosciences, and Biosciences. Sandia National Laboratories is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94-AL85000. MV acknowledges the support of the Italian Ministry of University and Research (MIUR). NR 15 TC 1 Z9 1 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 53 EP 57 DI 10.1088/1742-6596/46/1/007 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300007 ER PT S AU Barber, JL Kadau, K Germann, TC Lomdahl, PS Holian, BL Alder, BJ AF Barber, J. L. Kadau, K. Germann, T. C. Lomdahl, P. S. Holian, B. L. Alder, B. J. BE Tang, WM TI Atomistic simulation of the NAMERayleigh-TaylorNAME instability SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB Large-scale atomistic simulations are performed using both the molecular dynamics and direct simulation Monte Carlo algorithms. These simulations are used to investigate several aspects of turbulent behavior, focusing on the Rayleigh-Taylor instability, in which a heavy fluid lies on top of a light fluid in the presence of a gravitational field. The use of atomistic techniques allows us to capture various physical effects not resolved by more traditional continuum methods, such as the discontinuous breakup of flow features, and the effects of micro-scale fluctuations. In addition, we compare with both experiment and continuum simulations such properties as the initial growth spectrum of the interface, and the development in time of the mixing zone width. C1 [Barber, J. L.; Kadau, K.; Germann, T. C.; Lomdahl, P. S.; Holian, B. L.] Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. [Alder, B. J.] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Barber, JL (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM jlbarber@lanl.gov OI Germann, Timothy/0000-0002-6813-238X FU U.S. Department of Energy at Los Alamos National Laboratory [DE-AC52-06NA25396] FX This work was carried out under the auspices of the National Nuclear Security Administration of the U.S. Department of Energy at Los Alamos National Laboratory under Contract No. DE-AC52-06NA25396. NR 14 TC 4 Z9 4 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 58 EP 62 DI 10.1088/1742-6596/46/1/008 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300008 ER PT S AU Lee, WW Ethier, S Wang, WX Tang, WM Klasky, S AF Lee, W. W. Ethier, S. Wang, W. X. Tang, W. M. Klasky, S. BE Tang, WM TI Gyrokinetic particle simulation of fusion plasmas: path to petascale computing SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID ALFVEN WAVES; TOKAMAK; TURBULENCE AB Gyrokinetic particle simulation of fusion plasmas for studying turbulent transport on state-of-the-art computers has a long history of important scientific discoveries. The primary examples are: (i) the identification of ion temperature gradient (ITG) drift turbulence as the most plausible process responsible for the thermal transport observed in tokamak experiments; (ii) the reduction of such transport due to the presence of zonal flows; (iii) the confinement scaling trends associated with size of the plasma and also with the ionic isotope species. With the availability of terascale computers in recent years, we have also been able to carry out simulations with improved physics fidelity using experimentally relevant parameters. Computationally, we have demonstrated that our lead Particle-in-Cell (PIC) code, the Gyrokinetic Turbulence Code (GTC), is portable, efficient, and scalable on various MPP platforms. Convergence studies with unprecedented phase-space resolution have also been carried out. Since petascale resources are expected to be available in the near future, we have also engaged in developing better physics models and more efficient numerical algorithms to take advantage of this exciting opportunity. For the near term, we are interested in understanding some basic physics issues related to burning plasmas experiments in International Thermonuclear Experimental Reactor (ITER) - a multi-billion dollar device to be constructed over the next decade. Our long range goal is to carry out integrated simulations for ITER plasmas for a wide range of temporal and spatial scales, including high-frequency short-wavelength wave heating, low-frequency meso-scale transport, and low-frequency large scale magnetohydrodynamic (MHD) physics on these computers. C1 [Lee, W. W.; Ethier, S.; Wang, W. X.; Tang, W. M.] Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. [Klasky, S.] Oak Ridge Natl Lab, Oak Ridge, TN USA. RP Lee, WW (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. FU DoE [DE-AC02-76-CHO3037]; SciDAC Gyrokinetic Particle Simulation Center FX The work is supported by DoE contract DE-AC02-76-CHO3037 and the SciDAC Gyrokinetic Particle Simulation Center for Turbulent Transport in Burning Plasmas. NR 13 TC 5 Z9 5 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 73 EP 81 DI 10.1088/1742-6596/46/1/010 PG 9 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300010 ER PT S AU Jaeger, EF Harvey, RW Lynch, VE Ershov, N Berry, LA Bonoli, PT Tang, V Moore, RD AF Jaeger, E. F. Harvey, R. W. Lynch, V. E. Ershov, N. Berry, L. A. Bonoli, P. T. Tang, V. Moore, R. D. CA SciDAC Center Simulation Wave-P BE Tang, WM TI Quasilinear evolution of non-thermal distributions in ion cyclotron resonance heating of tokamak plasmas SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB The AORSA global-wave solver is combined with the CQL3D bounce-averaged Fokker-Planck code to simulate the quasilinear evolution of non-thermal distributions in ion cyclotron resonance heating of tokamak plasmas. A novel re-formulation of the quasilinear operator enables calculation of the velocity space diffusion coefficients directly from the global wave fields. To obtain self-consistency between the wave fields and particle distribution function, AORSA and CQL3D have been iteratively coupled using Python. The combined self-consistent model is applied to minority ion heating in the Alcator C-Mod tokamak. Results show the formation of a 70 keV ion tail near the minority ion cyclotron resonance layer in approximate agreement with measurements from charge exchange neutral particle analyzers. C1 [Jaeger, E. F.; Lynch, V. E.; Berry, L. A.; Moore, R. D.] Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. [Harvey, R. W.; Ershov, N.] CompX, San Diego, CA 92014 USA. [Bonoli, P. T.; Tang, V.] MIT, Ctr Plasma Fus, Cambridge, MA 02139 USA. RP Jaeger, EF (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. EM jaegeref@ornl.gov RI Lynch, Vickie/J-4647-2012; Ershov, Nikolay/E-4162-2013 OI Lynch, Vickie/0000-0002-5836-7636; FU SciDAC; Oak Ridge National Laboratory; U.S. Department of Energy [DE-AC-05- 00OR22725] FX This work was sponsored by SciDAC and the Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Department of Energy under Contract No. DE-AC-05- 00OR22725. Numerical calculations were carried out with resources of the National Center for Computational Sciences at Oak Ridge National Laboratory and the National Energy Research Scientific Computing Center at the Lawrence Berkeley National Laboratory. NR 7 TC 2 Z9 2 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 82 EP 86 DI 10.1088/1742-6596/46/1/011 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300011 ER PT S AU Ku, S Chang, CS Adams, M Cummings, J Hinton, F Keyes, D Klasky, S Lee, W Lin, Z Parker, S AF Ku, S. Chang, C-S Adams, M. Cummings, J. Hinton, F. Keyes, D. Klasky, S. Lee, W. Lin, Z. Parker, S. CA CPES Team BE Tang, WM TI Gyrokinetic particle simulation of neoclassical transport in the pedestal/scrape-off region of a tokamak plasma SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID EDGE; GEOMETRY AB A gyrokinetic neoclassical solution for a diverted tokamak edge plasma has been obtained for the first time using the massively parallel Jaguar XT3 computer at Oak Ridge National Laboratory. The solutions show similar characteristics to the experimental observations: electric potential is positive in the scrape-off layer and negative in the H-mode layer, and the parallel rotation is positive in the scrape-off layer and at the inside boundary of the H-mode layer. However, the solution also makes a new physical discovery that there is a strong ExB convective flow in the scrape-off plasma. A general introduction to the edge simulation problem is also presented. C1 [Ku, S.; Chang, C-S] NYU, Courant Inst Math Sci, 251 Mercer St, New York, NY 10003 USA. [Adams, M.; Keyes, D.] Columbia Univ, New York, NY 10027 USA. [Cummings, J.] CALTECH, Pasadena, CA 91125 USA. [Hinton, F.] Hinton Associates, New Cumberland, PA USA. [Klasky, S.] Oak Ridge Natl Lab, Oak Ridge, TN USA. [Lee, W.] Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. [Lin, Z.] Univ Calif Irvine, Irvine, CA USA. [Parker, S.] Univ Colorado Boulder, Boulder, CO USA. [CPES Team] SciDAC Fus Simulat Prototype Ctr Pla Edge Simulat, Boulder, CO USA. RP Ku, S (reprint author), NYU, Courant Inst Math Sci, 251 Mercer St, New York, NY 10003 USA. EM cschang@cims.nyu.edu RI Ku, Seung-Hoe/D-2315-2009 OI Ku, Seung-Hoe/0000-0002-9964-1208 NR 6 TC 15 Z9 15 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 87 EP 91 DI 10.1088/1742-6596/46/1/012 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300012 ER PT S AU Breslau, JA Park, W Jardin, SC AF Breslau, J. A. Park, W. Jardin, S. C. BE Tang, WM TI Massively parallel modeling of the sawtooth instability in tokamaks SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID PLASMA AB The sawtooth instability is one of the most fundamental dynamics of an inductive tokamak discharge such as will occur in ITER. The sawtooth occurs when the current peaks in a tokamak, creating a region in the core where the safety factor is less than unity, q < 1. While this instability is confined to the center of the plasma in low-pressure, low-current, large-aspect-ratio discharges, under certain conditions it can create magnetic islands at the outer resonant surfaces or set off a sequence of events that leads to a major disruption. Sawtooth behavior is complex and remains incompletely explained. The SciDAC Center for Extended MHD Modeling (CEMM) has undertaken an ambitious campaign to model this periodic motion as accurately as possible using the most complete fluid-like description of the plasma - the Extended MHD model. The multiple time and space scales associated with the reconnection layer and growth time make this an extremely challenging computational problem. The most recent simulation by the M3D code used over 500,000 elements for 400,000 partially implicit time steps for a total of 2x10(11) space-time points, and there still remain some resolution issues. However, these calculations are providing insight into the nonlinear mechanisms of surface breakup and healing. We have been able to match many features of a small tokamak and can now project to the computational requirements for simulations of larger, hotter devices such as ITER. C1 [Breslau, J. A.; Park, W.; Jardin, S. C.] Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RP Breslau, JA (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. EM jbreslau@pppl.gov FU U.S. Department of Energy [DE-AC02-76CH03073]; Department of Energy SciDAC Center; Extended Magnetohydrodynamic Modeling. Calculations were performed at the National Energy Research Scientific Computing Center (NERSC) FX The authors are grateful for useful discussions with R. Kaita, and with members of the SciDAC Center for Extended MHD Modeling (CEMM), particularly H. Strauss, L. Sugiyama, G. Y. Fu, J. Chen, D. Schnack, A. Pankin, S. Kruger, and C. Sovinec, and for visualization support from S. Klasky. This work was supported by U.S. Department of Energy Contract No. DE-AC02-76CH03073 and by the Department of Energy SciDAC Center for Extended Magnetohydrodynamic Modeling. Calculations were performed at the National Energy Research Scientific Computing Center (NERSC). NR 8 TC 0 Z9 0 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 97 EP 101 DI 10.1088/1742-6596/46/1/014 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300014 ER PT S AU Schissel, DP Gottschalk, EE Greenwald, MJ McCune, D AF Schissel, D. P. Gottschalk, E. E. Greenwald, M. J. McCune, D. BE Tang, WM TI Collaborative technologies for distributed science: fusion energy and high-energy physics SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID REMOTE COLLABORATION; SUPPORT; MDSPLUS AB This paper outlines a strategy to significantly enhance scientific collaborations in both Fusion Energy Sciences and in High-Energy Physics through the development and deployment of new tools and technologies into working environments. This strategy is divided into two main elements, collaborative workspaces and secure computational services. Experimental and theory/computational programs will greatly benefit through the provision of a flexible, standards-based collaboration space, which includes advanced tools for ad hoc and structured communications, shared applications and displays, enhanced interactivity for remote data access applications, high performance computational services and an improved security environment. The technologies developed should be prototyped and tested on the current generation of experiments and numerical simulation projects. At the same time, such work should maintain a strong focus on the needs of the next generation of mega-projects, ITER and the ILC. Such an effort needs to leverage existing computer science technology and take full advantage of commercial software wherever possible. This paper compares the requirements of FES and HEP, discuss today's solutions, examine areas where more functionality is required, and discuss those areas with sufficient overlap in requirements that joint research into collaborative technologies will increase the benefit to both. C1 [Schissel, D. P.] Gen Atom Co, San Diego, CA 92121 USA. [Gottschalk, E. E.] Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. [Greenwald, M. J.] MIT, Cambridge, MA 02139 USA. [McCune, D.] Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Schissel, DP (reprint author), Gen Atom Co, San Diego, CA 92121 USA. EM schissel@fusion.gat.com OI Greenwald, Martin/0000-0002-4438-729X NR 12 TC 0 Z9 0 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 102 EP 106 DI 10.1088/1742-6596/46/1/015 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300015 ER PT S AU Karsch, F AF Karsch, Frithjof BE Tang, WM TI Lattice simulations of the thermodynamics of strongly interacting elementary particles and the exploration of new phases of matter in relativistic heavy ion collisions SO SciDAC 2006: Scientific Discovery Through Advanced Computing SE JOURNAL OF PHYSICS CONFERENCE SERIES LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID GAUGE-THEORY; FLAVOR QCD; EQUATION; STATE; COLLABORATION; DENSITIES AB At high temperatures or densities matter formed by strongly interacting elementary particles (hadronic matter) is expected to undergo a transition to a new form of matter - the quark gluon plasma - in which elementary particles (quarks and gluons) are no longer confined inside hadrons but are free to propagate in a thermal medium much larger in extent than the typical size of a hadron. The transition to this new form of matter as well as properties of the plasma phase are studied in large scale numerical calculations based on the theory of strong interactions - (quantum Chromo Dynamics (QCD). Experimentally properties of hot and dense elementary particle matter are studied in relativistic heavy ion collisions such as those currently performed at the relativistic heavy ion collider (RHIC) at BNL. We review here recent results from studies of thermodynamic properties of strongly interacting elementary particle matter performed on Teraflops-Computer. We present results on the QCD equation of state and discuss the status of studies of the phase diagram at non-vanishing baryon number density. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Karsch, F (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 36 TC 59 Z9 59 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 122 EP 131 DI 10.1088/1742-6596/46/1/017 PG 10 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300017 ER PT S AU Brower, RC Detar, CE Edwards, RG Holmgren, DJ Mawhinney, RD Watson, W Zhangs, Y AF Brower, R. C. DeTar, C. E. Edwards, R. G. Holmgren, D. J. Mawhinney, R. D. Watson, W., III Zhangs, Y. BE Tang, WM TI National software infrastructure for lattice quantum chromodynamics SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB (quantum chromodynamics (QCD) is the widely accepted theory of the strong interactions of quarks and gluons. Only through large scale numerical simulation has it been possible to work out the predictions of this theory for a vast range of phenomena relevant to the US Department of Energy experimental program. Such simulations are essential to support the discovery of new phenomena and more fundamental interactions. With support from SciDAC the USQCD collaboration has developed software and prototyped custom computer hardware to carry out the required numerical simulations. We have developed a robust; portable data-parallel code suite. It provides a user-friendly basis for writing physics application codes for carrying out the calculations needed to predict the phenomenology of QCD. We are using this efficient and optimized code base to develop new physics application code, to improve the performance of legacy code, and to construct higher level tools; such as QCD-specific sparse matrix solvers. We give a brief overview of the design of the data parallel API and its various components. We describe performance gains achieved in the past year. Finally, we present plans for further improvements under SciDAC-2. C1 [Brower, R. C.] Boston Univ, Dept Phys, 590 Commonwealth Ave, Boston, MA 02215 USA. [DeTar, C. E.] Univ Utah, Dept Phys, Salt Lake City, UT 85112 USA. [Edwards, R. G.; Watson, W., III] Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. [Holmgren, D. J.] Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. [Mawhinney, R. D.] Columbia Univ, Dept Phys, New York, NY 10027 USA. [Zhangs, Y.] Univ N Carolina, Dept Comp Sci, Chapel Hill, NC 27599 USA. RP Brower, RC (reprint author), Boston Univ, Dept Phys, 590 Commonwealth Ave, Boston, MA 02215 USA. EM browers@lns.mit.edu; detar@physics.utah.edu; edwards@jlab.org; djholm@fnal.gov; rdm@phys.columbia.edu; watson@jlab.org; zhang8@cs.uiuc.edu OI Holmgren, Donald/0000-0001-6701-7737 NR 4 TC 0 Z9 0 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 142 EP 146 DI 10.1088/1742-6596/46/1/019 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300019 ER PT S AU Kronfeld, AS AF Kronfeld, Andreas S. CA Fermilab Lattice Collaboration Collaborations, M HPQCD Collaborations BE Tang, WM TI Predictions with lattice QCD SO SciDAC 2006: Scientific Discovery Through Advanced Computing SE JOURNAL OF PHYSICS CONFERENCE SERIES LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID FORM-FACTORS; B-C; HEAVY; MASS AB In recent years, we used lattice QCD to calculate some quantities that were unknown or poorly known. They are the q(2) dependence of the form factor in semileptonic D -> Klv decay, the leptonic decay constants of the D+ and D-s mesons, and the mass of the B-c meson. In this paper, we summarize these calculations, with emphasis on their (subsequent) confirmation by measurements in e(+)e(-), gamma p and pp collisions. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Kronfeld, AS (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 32 TC 7 Z9 7 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 147 EP 151 DI 10.1088/1742-6596/46/1/020 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300020 ER PT S AU Renner, DB Edwards, RG Fleming, G Hagler, P Negele, JW Orginos, K Pochinsky, AV Richards, DG Schroers, W AF Renner, D. B. Edwards, R. G. Fleming, G. Haegler, Ph Negele, J. W. Orginos, K. Pochinsky, A. V. Richards, D. G. Schroers, W. BE Tang, WM TI Calculation of the nucleon axial charge in lattice QCD SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB Protons and neutrons have a rich structure in terms of their constituents, the quarks and gluons. Understanding this structure requires solving Quantum Chromodynamics (QCD). However QCD is extremely complicated, so we must numerically solve the equations of QCD using a method known as lattice QCD. Here we describe a typical lattice QCD calculation by examining our recent computation of the nucleon axial charge. C1 [Renner, D. B.] Univ Arizona, Dept Phys, 1118 E 4th St, Tucson, AZ 85721 USA. [Edwards, R. G.; Orginos, K.; Richards, D. G.] Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. [Fleming, G.] Yale Univ, Sloane Phys Lab, New Haven, CT 06520 USA. [Haegler, Ph] Tech Univ Munich, Inst Theoret Phys, D-85747 Garching, Germany. [Negele, J. W.; Pochinsky, A. V.] MIT, Ctr Theoret Phys, Cambridge, MA 02139 USA. [Orginos, K.] Coll William & Mary, Dept Phys, Williamsburg, VA 23185 USA. [Schroers, W.] DESY, John von Neumann Inst Comp NIC, D-15738 Zeuthen, Germany. RP Renner, DB (reprint author), Univ Arizona, Dept Phys, 1118 E 4th St, Tucson, AZ 85721 USA. RI Fleming, George/L-6614-2013 OI Fleming, George/0000-0002-4987-7167 NR 7 TC 2 Z9 2 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 152 EP 156 DI 10.1088/1742-6596/46/1/021 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300021 ER PT S AU Dean, DJ AF Dean, D. J. CA NSLER Collaboration BE Tang, WM TI The nuclear structure and low-energy reactions (NSLER) collaboration SO SciDAC 2006: Scientific Discovery Through Advanced Computing SE JOURNAL OF PHYSICS CONFERENCE SERIES LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB The long-term vision of the Nuclear Structure and Low-Energy Reactions (NSLER) collaboration is to arrive at a comprehensive and unified description of nuclei and their reactions that is grounded in the interactions between the constituent nucleons. For this purpose, we will develop a universal energy density functional for nuclei and replace current phenomenological models of nuclear structure and reactions with a well-founded microscopic theory that will deliver maximum predictive power with minimal uncertainties that are well quantified. Nuclear structure and reactions play an essential role in the science to be investigated at rare isotope facilities, and in nuclear physics applications to the Science-Based Stockpile Stewardship Program, next-generation reactors, and threat reduction. We anticipate an expansion of the computational techniques and methods we currently employ, and developments of new treatments, to take advantage of petascale architectures and demonstrate the capability of the leadership class machines to deliver new science heretofore impossible. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RP Dean, DJ (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. OI Dean, David/0000-0002-5688-703X NR 7 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 166 EP 170 DI 10.1088/1742-6596/46/1/024 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300024 ER PT S AU Ryne, RD AF Ryne, Robert D. BE Tang, WM TI Extraordinary tools for extraordinary science: the impact of SciDAC on accelerator science & technology SO SciDAC 2006: Scientific Discovery Through Advanced Computing SE JOURNAL OF PHYSICS CONFERENCE SERIES LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID ELECTRON-BEAMS; SIMULATION AB Particle accelerators are among the most complex and versatile instruments of scientific exploration. They have enabled remarkable scientific discoveries and important technological advances that span all programs within the DOE Office of Science (DOE/SC). The importance of accelerators to the DOE/SC mission is evident from an examination of the DOE document, "Facilities for the Future of Science: A Twenty-Year Outlook." Of the 28 facilities listed, 13 involve accelerators. Thanks to SciDAC, a powerful suite of parallel simulation tools has been developed that represent a paradigm shift in computational accelerator science. Simulations that used to take weeks or more now take hours, and simulations that were once thought impossible are now performed routinely. These codes have been applied to many important projects of DOE/SC including existing facilities (the Tevatron complex, the Relativistic Heavy Ion Collider), facilities under construction (the Large Hadron Collider, the Spallation Neutron Source, the Linac Coherent Light Source), and to future facilities (the International Linear Collider, the Rare Isotope Accelerator). The new codes have also been used to explore innovative approaches to charged particle acceleration. These approaches, based on the extremely intense fields that can be present in lasers and plasmas, may one day provide a path to the outermost reaches of the energy frontier. Furthermore, they could lead to compact, high-gradient accelerators that would have huge consequences for US science and technology, industry, and medicine. In this talk I will describe the new accelerator modeling capabilities developed under SciDAC, the essential role of multi-disciplinary collaboration with applied mathematicians, computer scientists, and other IT experts in developing these capabilities, and provide examples of how the codes have been used to support DOE/SC accelerator projects. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Ryne, RD (reprint author), Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 27 TC 1 Z9 1 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 171 EP 189 DI 10.1088/1742-6596/46/1/025 PG 19 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300025 ER PT S AU Cary, JR Abell, D Amundson, J Bruhwiler, DL Busby, R Carlsson, JA Dimitrov, DA Kashdan, E Messmer, P Nieter, C Smithe, DN Spentzouris, P Stoltz, P Trines, RM Wang, H Wernerz, GR AF Cary, John R. Abell, D. Amundson, J. Bruhwiler, D. L. Busby, R. Carlsson, J. A. Dimitrov, D. A. Kashdan, E. Messmer, P. Nieter, C. Smithe, D. N. Spentzouris, P. Stoltz, P. Trines, R. M. Wang, H. Wernerz, G. R. BE Tang, WM TI Petascale self-consistent electromagnetic computations using scalable and accurate algorithms for complex structures SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB As the size and cost of particle accelerators escalate, high-performance computing plays an increasingly important role; optimization through accurate, detailed computer-modeling increases performance and reduces costs. But consequently, computer simulations face enormous challenges. Early approximation methods, such as expansions in distance from the design orbit, were unable to supply detailed accurate results, such as in the computation of wake fields in complex cavities. Since the advent of message-passing supercomputers with thousands of processors, earlier approximations are no longer necessary, and it is now possible to compute wake fields, the effects of dampers, and self-consistent dynamics in cavities accurately. In this environment, the focus has shifted towards the development and implementation of algorithms that scale to large numbers of processors. So-called charge-conserving algorithms evolve the electromagnetic fields without the need for any global solves (which are difficult to scale up to many processors). Using cut-cell (or embedded) boundaries, these algorithms can simulate the fields in complex accelerator cavities with curved walls. New implicit algorithms, which are stable for any time-step, conserve charge as well, allowing faster simulation of structures with details small compared to the characteristic wavelength. These algorithmic and computational advances have been implemented in the VORPAL[1] Framework, a flexible, object-oriented, massively parallel computational application that allows run-time assembly of algorithms and objects, thus composing an application on the fly. C1 [Cary, John R.; Amundson, J.; Bruhwiler, D. L.; Busby, R.; Carlsson, J. A.; Dimitrov, D. A.; Messmer, P.; Nieter, C.; Smithe, D. N.; Stoltz, P.] Tech X Corp, Boulder, CO 80303 USA. [Cary, John R.; Kashdan, E.; Wernerz, G. R.] Univ Colorado, Boulder, CO 80309 USA. [Amundson, J.; Spentzouris, P.] Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. [Trines, R. M.] Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. [Wang, H.] Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. RP Cary, JR (reprint author), Tech X Corp, Boulder, CO 80303 USA. EM cary@txcorp.com OI Kashdan, Eugene/0000-0002-8137-4981; Carlsson, Johan/0000-0003-4614-8150 FU U.S. Department of Energy (DOE) Office of Science; Office of High Energy Physics through the SciDAC project "Advanced Computing for 21st Century Accelerator Science and Technology" [DE-FC02-01ER41178]; DOE Office of Science [DE-AC02-05CH11231] FX This work is primarily supported by the U.S. Department of Energy (DOE) Office of Science, Office of High Energy Physics through the SciDAC project Advanced Computing for 21st Century Accelerator Science and Technology under various grant and contract No.s, including DE-FC02-01ER41178. Additional support was provided by the same office, under multiple grant No.s, including DE-FG03-95ER40926. This work used resources of the National Energy Research Scientific Computing Center, which is supported by the DOE Office of Science under Contract No. DE-AC02-05CH11231. Partial support was also provided by Tech-X Corp. NR 7 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 200 EP 204 DI 10.1088/1742-6596/46/1/027 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300027 ER PT S AU Amundson, J Qiang, J Ryne, R Spentzouris, P Stern, E Valishev, A AF Amundson, J. Qiang, J. Ryne, R. Spentzouris, P. Stern, E. Valishev, A. BE Tang, WM TI Development and validation of self-consistent 3D beam-beam modeling code within SciDAC SO SciDAC 2006: Scientific Discovery Through Advanced Computing SE JOURNAL OF PHYSICS CONFERENCE SERIES LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB The calculation of beam-beam effects has been an ongoing activity within SciDAC. We report the first validation of a detailed beam-beam simulation with data measured at the VEPP-2M collider in Novosbirsk. The validation of the simulation gives us confidence to apply it to understanding and improving the operation of existing colliders such as the Tevatron, RHIC and LHC, and the design of the International Linear Collider. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Amundson, J (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 8 TC 1 Z9 1 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 205 EP 209 DI 10.1088/1742-6596/46/1/028 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300028 ER PT S AU Bruhwiler, DL Antonsen, T Cary, JR Cooley, J Decyk, VK Esarey, E Geddess, CGR Huang, C Hakim, A Katsouleas, T Messmer, P Mori, WB Tsung, FS Vieira, J Zhou, M AF Bruhwiler, D. L. Antonsen, T. Cary, J. R. Cooley, J. Decyk, V. K. Esarey, E. Geddess, C. G. R. Huang, C. Hakim, A. Katsouleas, T. Messmer, P. Mori, W. B. Tsung, F. S. Vieira, J. Zhou, M. BE Tang, WM TI Towards the petascale in electromagnetic modeling of plasma-based accelerators for high-energy physics SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID CHARGE CONSERVATION; ELECTRON-BEAMS AB Plasma-based lepton acceleration concepts are a key element of the long-term R&D portfolio for the U.S. Office of High Energy Physics. There are many such concepts [1], but we consider only the laser (LWFA) and plasma (PWFA) wakefield accelerators. We present a summary of electromagnetic particle-in-cell (PIC) simulations for recent LWFA and PWFA experiments. These simulations, including both time explicit algorithms and reduced models, have effectively used terascale computing resources to support and guide experiments in this rapidly developing field. We briefly discuss the challenges and opportunities posed by the near-term availability of petascale computing hardware. C1 [Bruhwiler, D. L.; Cary, J. R.; Hakim, A.; Messmer, P.] Tech X Corp, Boulder, CO 80303 USA. [Antonsen, T.; Cooley, J.] Univ Maryland, College Pk, MD 20742 USA. [Cary, J. R.] Univ Colorado, Boulder, CO 80309 USA. [Decyk, V. K.; Huang, C.; Mori, W. B.; Tsung, F. S.; Zhou, M.] Univ Calif Los Angeles, Los Angeles, CA 90095 USA. [Esarey, E.; Geddess, C. G. R.] Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. [Katsouleas, T.] Univ Southern Calif, Los Angeles, CA 90089 USA. [Vieira, J.] Inst Super Tecn, P-1049001 Lisbon, Portugal. RP Bruhwiler, DL (reprint author), Tech X Corp, Boulder, CO 80303 USA. EM bruhwile@txcorp.com RI Vieira, Jorge/M-4373-2013 OI Vieira, Jorge/0000-0002-5515-3624 FU U.S. Department of Energy (DOE) Office of Science; Office of High Energy Physics through the SciDAC project "Advanced Computing for 21st Century Accelerator Science and Technology" [DE-FC02-01ER41178, DE-FC02-01ER41179]; DOE Office of Science [DE-AC02-05CH11231]; DAWSON [Phy-0321345]; DOE [DE-FG02-03ER54721]; [DE-FG03-95ER40926]; [DE-FG03- 92ER40727] FX This work is primarily supported by the U.S. Department of Energy (DOE) Office of Science, Office of High Energy Physics through the SciDAC project Advanced Computing for 21st Century Accelerator Science and Technology under various grant and contract No.s, including DE-FC02-01ER41178, DE-FC02-01ER41179, and DE-AC02-05CH11231. Additional support was provided by the same office, under multiple grant No.s, including DE-FG03-95ER40926 and DE-FG03- 92ER40727. This work used resources of the National Energy Research Scientific Computing Center, which is supported by the DOE Office of Science under Contract No. DE-AC02-05CH11231, and the DAWSON Cluster under NSF Phy-0321345. Partial support was also provided by Tech-X Corp. andby DOE under DE-FG02-03ER54721. NR 25 TC 1 Z9 1 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 215 EP 219 DI 10.1088/1742-6596/46/1/030 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300030 ER PT S AU Janssen, CL Kenny, JP Nielsen, IMB Krishnan, M Gurumoorthi, V Valeev, EF Windus, TL AF Janssen, C. L. Kenny, J. P. Nielsen, I. M. B. Krishnan, M. Gurumoorthi, V. Valeev, E. F. Windus, T. L. BE Tang, WM TI Enabling new capabilities and insights from quantum chemistry by using component architectures SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID BASIS-SETS; TERMS AB Steady performance gains in computing power, as well as improvements in scientific computing algorithms, are making possible the study of coupled physical phenomena of great extent and complexity. The software required for such studies is also very complex and requires contributions from experts in multiple disciplines. We have investigated the use of the Common Component Architecture (CCA) as a mechanism to tackle some of the resulting software engineering challenges in quantum chemistry, focusing on three specific application areas. In our first application, we have developed interfaces permitting solvers and quantum chemistry packages to be readily exchanged. This enables our quantum chemistry packages to be used with alternative solvers developed by specialists, remedying deficiencies we discovered in the native solvers provided in each of the quantum chemistry packages. The second application involves development of a set of components designed to improve utilization of parallel machines by allowing multiple components to execute concurrently on subsets of the available processors. This was found to give substantial improvements in parallel scalability. Our final application is a set of components permitting different quantum chemistry packages to interchange intermediate data. These components enabled the investigation of promising new methods for obtaining accurate thermochemical data for reactions involving heavy elements. C1 [Janssen, C. L.; Kenny, J. P.; Nielsen, I. M. B.] Sandia Natl Labs, POB 969, Livermore, CA 94551 USA. [Krishnan, M.; Gurumoorthi, V.] Pacific NorthWest Natl Lab, Richland, WA 99352 USA. [Valeev, E. F.] Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. RP Janssen, CL (reprint author), Sandia Natl Labs, POB 969, Livermore, CA 94551 USA. EM cljanss@sandia.gov RI Valeyev, Eduard/A-5313-2009 OI Valeyev, Eduard/0000-0001-9923-6256 FU United States Department of Energy [DE-AC04-94AL85000]; U.S. Department of Energy; Office of Biological Environmental Research and located at the Pacific Northwest National Laboratory FX Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94AL85000. This research was performed in part using the Molecular Science Computing Facility in the William R.Wiley Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the U.S. Department of Energy, Office of Biological Environmental Research and located at the Pacific Northwest National Laboratory operated for the DOE by Battelle. NR 22 TC 9 Z9 9 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 220 EP 228 DI 10.1088/1742-6596/46/1/031 PG 9 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300031 ER PT S AU Gordon, MS Ruedenberg, K Schmidt, MW Bytautas, L Dudley, TJ Nagata, T Olson, R Varganov, S AF Gordon, Mark S. Ruedenberg, Klaus Schmidt, Michael W. Bytautas, Laimis Dudley, Timothy J. Nagata, Takeshi Olson, Ryan Varganov, Sergey BE Tang, WM TI Scalable correlated electronic structure theory SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID DISTRIBUTED DATA INTERFACE AB The approach taken in Ames to advance high-level electronic structure theory has been a combination of the development and implementation of new and novel methods with the continuing development of strategies to optimize scalable computing. This work summarizes advances on both fronts. Several new methods have been implemented under the Distributed Data Interface (DDI), most recently including analytic Hessians for both Hatree-Fock and CASSCF (complete active space self-consistent field) wavefunctions, gradients for restricted open shell second order perturbation theory, and the fragment molecular orbital method (FMO). Exciting new method developments include the FMO method and the CEEIS (Correlation Energy Extrapolation by Intrinsic Scaling) method for efficiently approaching the exact energy for atomic and molecular systems. C1 [Gordon, Mark S.; Ruedenberg, Klaus; Schmidt, Michael W.; Bytautas, Laimis; Dudley, Timothy J.; Nagata, Takeshi; Olson, Ryan; Varganov, Sergey] Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Gordon, MS (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. OI Dudley, Timothy/0000-0002-6635-7956 FU Department of Energy SciDAC (Scientific Discovery Through Advanced Computing); Ames Laboratory; IBM hardware grants via the SUR (Shared University Research) program FX This work was supported by a Department of Energy SciDAC (Scientific Discovery Through Advanced Computing) grant to Ames Laboratory and by several IBM hardware grants via the SUR (Shared University Research) program. NR 9 TC 5 Z9 5 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 229 EP 233 DI 10.1088/1742-6596/46/1/032 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300032 ER PT S AU Shepard, R Wagner, AF Gray, SK AF Shepard, R. Wagner, A. F. Gray, S. K. BE Tang, WM TI Advanced software for the calculation of thermochemistry, kinetics, and dynamics SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB The Born-Oppenheimer separation of the Schrodinger equation allows the electronic and nuclear motions to be solved in three steps. 1) The solution of the electronic wave function at a discrete set of molecular conformations; 2) the fitting of this discrete set of energy values in order to construct an analytical approximation to the potential energy surface (PES) at all molecular conformations; 3) the use of this analytical PES to solve for the nuclear motion using either time-dependent or time-independent formulations to compute molecular energy values, chemical reaction rates, and cumulative reaction probabilities. This project involves the development of technology to address all three of these steps. This report focuses on our recent work on the optimization of nonlinear wave function parameters for the electronic wave functions. C1 [Shepard, R.; Wagner, A. F.; Gray, S. K.] Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. RP Shepard, R (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM shepard@tcg.anl.gov NR 10 TC 3 Z9 3 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 239 EP 243 DI 10.1088/1742-6596/46/1/034 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300034 ER PT S AU Kowalski, K Valiev, M AF Kowalski, Karol Valiev, Marat BE Tang, WM TI 05: Multiscale dynamical framework for high-level calculations of finite temperature ground and excited state properties SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID COUPLED-CLUSTER METHOD; EXCITATION-ENERGIES; ELECTRON CORRELATION AB There is a pressing need for accurate calculations of finite temperature ground and excited state properties of nanoscale systems relevant to structural biology, hydrogen economy, environmental and material science problems. To address this challenging task we have designed a multiscale dynamical approach that combines the accuracy and computational complexity of coupled-cluster (CC) methods with the efficiency of classical molecular dynamics simulations. Our methodology is based on a seamless integration between the generic QM/MM interface, Tensor Contraction Engine module, and the classical molecular dynamics module of NWChem and offers an unprecedented ability for accurate large scale calculations of thermodynamics of ground and excited state properties. We illustrate our approach by large scale dynamical simulation of the excited state spectrum of the cytosine base in its native DNA environment using a variant of the completely renormalized equation-of-motion method with singles, doubles, and non-iterative triples (CR-EOMCCSD(T)). C1 [Kowalski, Karol; Valiev, Marat] Pacific NW Natl Lab, Mol Sci Software Grp, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Kowalski, K (reprint author), Pacific NW Natl Lab, Mol Sci Software Grp, Environm Mol Sci Lab, Richland, WA 99352 USA. EM karol@kowalski@pnl.gov; marat.valiev@pnl.gov FU U.S. DOE, OBER at PNNL; Advanced Scientific Computing Research program of the U.S. Department of Energy, Office of Science [DE-AC06-76RLO 1830] FX This research was performed in part using the MSCF in EMSL, a national scientific user facility sponsored by the U.S. DOE, OBER and located at PNNL. We would also like to acknowledge support to M.V. from the Advanced Scientific Computing Research program of the U.S. Department of Energy, Office of Science (DE-AC06-76RLO 1830). NR 16 TC 0 Z9 0 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 244 EP 248 DI 10.1088/1742-6596/46/1/035 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300035 ER PT S AU Streitz, FH Glosli, JN Patel, MV Chan, B Yates, RK de Supinski, BR Sexton, J Gunnels, JA AF Streitz, Frederick H. Glosli, James N. Patel, Mehul V. Chan, Bor Yates, Robert K. de Supinski, Bronis R. Sexton, James Gunnels, John A. BE Tang, WM TI Simulating solidification in metals at high pressure: The drive to petascale computing SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID BOND-ORIENTATIONAL ORDER; LENNARD-JONES SYSTEM; MOLECULAR-DYNAMICS; TRANSITION-METALS; HOMOGENEOUS NUCLEATION; LOCAL-STRUCTURE; LIQUIDS; POTENTIALS; CRYSTALS AB We investigate solidification in metal systems ranging in size from 64,000 to 524,288,000 atoms on the IBM BlueGene/L computer at LLNL. Using the newly developed ddcMD code, we achieve performance rates as high as 103 TFlops, with a performance of 101.7 TFlop sustained over a 7 hour run on 131,072 cpus. We demonstrate superb strong and weak scaling. Our calculations are significant as they represent the first atomic-scale model of metal solidification to proceed, without finite size effects, from spontaneous nucleation and growth of solid out of the liquid, through the coalescence phase, and into the onset of coarsening. Thus, our simulations represent the first step towards an atomistic model of nucleation and growth that can directly link atomistic to mesoscopic length scales. C1 [Streitz, Frederick H.; Glosli, James N.; Patel, Mehul V.; Chan, Bor; Yates, Robert K.; de Supinski, Bronis R.] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. [Sexton, James; Gunnels, John A.] IBM Corp, Thomas J Watson Res Ctr, Yorktown Hts, NY 10598 USA. RP Streitz, FH (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM streitz1@llnl.gov OI Patel, Mehul/0000-0002-0486-010X FU U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory [W-7405-Eng-48] FX This work was performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48. NR 30 TC 18 Z9 18 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 254 EP 267 DI 10.1088/1742-6596/46/1/037 PG 14 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300037 ER PT S AU Kumar, P Nukala, VV Simunovic, S Mills, RT AF Kumar, P. Nukala, V. V. Simunovic, Srdan Mills, Richard T. BE Tang, WM TI Statistical physics of fracture: scientific discovery through high-performance computing SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID SPARSE CHOLESKY FACTORIZATION; 3-DIMENSIONAL FUSE NETWORKS; FOURIER ACCELERATION; STRUCTURAL STRENGTH; DISORDERED-SYSTEMS; SURFACES; CRACKS; ROUGHNESS; DIFFUSION; BREAKDOWN AB The paper presents the state-of-the-art algorithmic developments for simulating the fracture of disordered quasi-brittle materials using discrete lattice systems. Large scale simulations are often required to obtain accurate scaling laws; however, due to computational complexity, the simulations using the traditional algorithms were limited to small system sizes. We have developed two algorithms: a multiple sparse Cholesky downdating scheme for simulating 2D random fuse model systems, and a block-circulant preconditioner for simulating 3D random fuse model systems. Using these algorithms, we were able to simulate fracture of largest ever lattice system sizes (L = 1024 in 2D, and L = 64 in 3D) with extensive statistical sampling. Our recent simulations on 1024 processors of Cray-XT3 and IBM Blue-Gene/L have further enabled us to explore fracture of 3D lattice systems of size L = 200, which is a significant computational achievement. These largest ever numerical simulations have enhanced our understanding of physics of fracture; in particular, we analyze damage localization and its deviation from percolation behavior, scaling laws for damage density, universality of fracture strength distribution, size effect on the mean fracture strength, and finally the scaling of crack surface roughness. C1 [Kumar, P.; Nukala, V. V.; Simunovic, Srdan; Mills, Richard T.] Oak Ridge Natl Lab, Div Math & Comp Sci, POB 2008, Oak Ridge, TN 37831 USA. RP Kumar, P (reprint author), Oak Ridge Natl Lab, Div Math & Comp Sci, POB 2008, Oak Ridge, TN 37831 USA. EM nukalapk@ornl.gov FU Mathematical, Information and Computational Sciences Division, Office of Advanced Scientific Computing Research, U.S. Department of Energy [DE-AC05-00OR22725] FX PKVVN is sponsored by the Mathematical, Information and Computational Sciences Division, Office of Advanced Scientific Computing Research, U.S. Department of Energy under contract number DE-AC05-00OR22725 with UT-Battelle, LLC. PKVVN also acknowledges the use of BGL, a 1024-node BG/L machine operated by the Mathematics and Computer Science Division at Argonne National Laboratory through his INCITE Award. In addition, the research used resources of the Center for Computational Sciences at Oak Ridge National Laboratory. NR 52 TC 0 Z9 1 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 278 EP 291 DI 10.1088/1742-6596/46/1/039 PG 14 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300039 ER PT S AU Zunger, A Franceschetti, A Bester, G Jones, WB Kim, K Graf, PA Wang, LW Canning, A Marques, O Voemel, C Dongarra, J Langou, J Tomov, S AF Zunger, A. Franceschetti, A. Bester, G. Jones, W. B. Kim, Kwiseon Graf, P. A. Wang, L-W. Canning, A. Marques, O. Voemel, C. Dongarra, J. Langou, J. Tomov, S. BE Tang, WM TI Predicting the electronic properties of 3D, million-atom semiconductor nanostructure architectures SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID ALLOYS AB The past similar to 10 years have witnessed revolutionary breakthroughs both in synthesis of quantum dots (leading to nearly monodispersed, defect-free nanostructures) and in characterization of such systems, revealing ultra narrow spectroscopic lines of < 1meV width, exposing new intriguing effects, such as multiple exciton generation, fine-structure splitting, quantum entanglement, multiexciton recombination and more. These discoveries have led to new technological applications including quantum computing and ultra-high efficiency solar cells. Our work in this project is based on two realizations/observations: First, that the dots exhibiting clean and rich spectroscopic and transport characteristics are rather big. Indeed, the phenomenology indicated above is exhibited only by the well-passivated defect-free quantum dots containing at least a few thousand atoms (colloidal) and even a few hundred thousand atoms (self assembled). Understanding the behavior of nanotechnology devices requires the study of even larger, million-atom systems composed of multiple components such as wires+dots+films. Second, first-principles many-body computational techniques based on current approaches (Quantum Monte-Carlo, GW, Bethe-Salpeter) are unlikely to be adaptable to such large structures and, at the same time, the effective mass-based techniques are too crude to provide insights on the many-body/atomistic phenomenology revealed by experiment. Thus, we have developed a set of methods that use an atomistic approach (unlike effective-mass based techniques) and utilize single-particle + many body techniques that are readily scalable to similar to 10(3)-10(6) atom nanostructures. New mathematical and computational techniques have also been developed to accelerate our calculations and go beyond simple conjugate gradient based methods allowing us to study larger systems. In this short paper based on a poster presented at the DOE SciDAC06 conference we will present the overall structure as well as highlights of our computational nanoscience project. C1 [Zunger, A.; Franceschetti, A.; Bester, G.] NREL, Ctr Mat Sci, Golden, CO USA. [Jones, W. B.; Kim, Kwiseon; Graf, P. A.] NREL, Sci Comp Ctr, Golden, CO USA. [Wang, L-W.; Canning, A.; Marques, O.; Voemel, C.] Computat Res Div, LBNL, Berkeley, CA USA. [Dongarra, J.; Langou, J.; Tomov, S.] Univ Tennessee, Dept Comp Sci, Knoxville, TN 37996 USA. RP Canning, A (reprint author), NREL, Ctr Mat Sci, Golden, CO USA. EM acanning@lbl.gov RI Bester, Gabriel/I-4414-2012; Dongarra, Jack/E-3987-2014 OI Bester, Gabriel/0000-0003-2304-0817; FU US Department of Energy, Office of Science, Office of Advanced Scientific Computing (MICS) and Basic Energy Science [LAB03-17, DE-FG02-03ER25584, DE-AC03-76SF00098]; Office of Science of the U.S. Department of Energy FX This work was supported by the US Department of Energy, Office of Science, Office of Advanced Scientific Computing (MICS) and Basic Energy Science under LAB03-17 initiative (Theory, Modeling and Simulation in Nanoscience), contract Nos. DE-FG02-03ER25584 and DE-AC03-76SF00098. We also used computational resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy. We thank A. Knyazev and A. Stathopoulos for their advice regarding the use of the LOBPCG and the Jacobi-Davidson JaDa packages. NR 11 TC 7 Z9 7 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 292 EP 298 DI 10.1088/1742-6596/46/1/040 PG 7 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300040 ER PT S AU Mota, A Knap, J Ortiz, M AF Mota, Alejandro Knap, Jaroslaw Ortiz, Michael BE Tang, WM TI Three-dimensional fracture and fragmentation of artificial kidney stones SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID ELEMENTS AB The brittle fracture of a gypsum cylinder, which is used as an artificial kidney stone in lithotripsy research, is simulated by the use of the finite element method. The cylinder is submerged in water and is subjected to a pressure front parallel to one of its planar faces. The stresses induced by the pressure wave lead to fracture in the interior of the cylinder, with the formation of a spall plane located about 2/3 of the length from the face on which the pressure is applied. We show that the simulation reproduces the salient features of experimental observations. C1 [Mota, Alejandro; Ortiz, Michael] CALTECH, Div Engn & Appl Sci, Pasadena, CA 91125 USA. [Knap, Jaroslaw] Chem & Mat Sci Directorate, Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Ortiz, M (reprint author), CALTECH, Div Engn & Appl Sci, Pasadena, CA 91125 USA. EM ortiz@aero.caltech.edu FU US Department of Energy through Caltech's ASC Center for the Simulation of the Dynamic Response of Materials; US National Institute of Health [DK43881] FX We are grateful for the financial support provided by the US Department of Energy through Caltechs ASC Center for the Simulation of the Dynamic Response of Materials and the US National Institute of Health through grant DK43881. NR 7 TC 7 Z9 7 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 299 EP 303 DI 10.1088/1742-6596/46/1/041 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300041 ER PT S AU Fink, LJD Martin, MG Salinger, AG Heroux, MA AF Douglas Fink, Laura J. Martin, Marcus G. Salinger, Andrew G. Heroux, Micheal A. BE Tang, WM TI High performance computing for the application of molecular theories to biological systems. SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID DENSITY-FUNCTIONAL THEORY; INHOMOGENEOUS FLUIDS; SIMULATION; MEMBRANE; SOLVENT; MODELS AB In this paper we summarize our work to bring modern numerical methods to bear in computations for density functional theories (DFTs) of inhomogeneous fluid systems. We present the general mathematical structure of the problem, and briefly discuss different strategies for solving the problems. Finally, we present a few recent results from calculations on complex peptide assemblies in lipid bilayers to demonstrate the application of the methods in one complex 3-dimensional system. We find that while solver strategies developed and optimized for partial differential equations (PDEs) can be applied to these systems of equations, they do not provide optimal solutions with respect to speed, memory use, or parallel partitioning. C1 [Douglas Fink, Laura J.; Martin, Marcus G.; Salinger, Andrew G.; Heroux, Micheal A.] Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RP Fink, LJD (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM ljfrink@sandia.gov OI Heroux, Michael/0000-0002-5893-0273 NR 18 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 304 EP 310 DI 10.1088/1742-6596/46/1/042 PG 7 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300042 ER PT S AU Uberbacher, E LoCascio, P Passovets, S Ghattyvenkatakrishna, P Agarwal, P Arnold, N Bordner, A Gorin, A AF Uberbacher, Ed LoCascio, Philip Passovets, Sergey Ghattyvenkatakrishna, Pavan Agarwal, Pratul Arnold, Nikita Bordner, Andrew Gorin, Andrey BE Tang, WM TI Computational challenges for modeling and simulating biomacromolecular assemblies SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID SEQUENCE; PERSPECTIVE; BIOETHANOL; PROTEINS; DYNAMICS AB Understanding the structure and dynamics of large biomolecular assemblies requires the development of new computational methods for (i) accurate structure prediction, (ii) molecular docking and (iii) long time-frame molecular simulation, and implementation on massively parallel computing infrastructure. This paper reviews our progress in these areas and applications on important molecular systems. C1 [Uberbacher, Ed; LoCascio, Philip; Passovets, Sergey; Ghattyvenkatakrishna, Pavan; Agarwal, Pratul; Arnold, Nikita; Bordner, Andrew; Gorin, Andrey] Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. RP Uberbacher, E (reprint author), Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. EM ube@ornl.gov RI Arnold, Nikita/C-7790-2013; Gorin, Andrey/B-1545-2014 OI Arnold, Nikita/0000-0003-3673-1772; NR 15 TC 1 Z9 1 U1 1 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 311 EP 315 DI 10.1088/1742-6596/46/1/043 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300043 ER PT S AU Trebotich, D AF Trebotich, David BE Tang, WM TI Modeling complex biological flows in multi-scale systems using the APDEC framework SO SciDAC 2006: Scientific Discovery Through Advanced Computing SE JOURNAL OF PHYSICS CONFERENCE SERIES LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID EMBEDDED BOUNDARY METHOD AB We have developed advanced numerical algorithms to model biological fluids in multiscale flow environments using the software framework developed under the SciDAC APDEC ISIC. The foundation of our computational effort is an approach for modeling DNA-laden fluids as "bead-rod" polymers whose dynamics are fully coupled to an incompressible viscous solvent. The method is capable of modeling short range forces and interactions between particles using soft potentials and rigid constraints. Our methods are based on higher-order finite difference methods in complex geometry with adaptivity, leveraging algorithms and solvers in the APDEC Framework. Our Cartesian grid embedded boundary approach to incompressible viscous flow in irregular geometries has also been interfaced to a fast and accurate level-sets method within the APDEC Framework for extracting surfaces from volume renderings of medical image data and used to simulate cardio-vascular and pulmonary flows in critical anatomies. C1 Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. RP Trebotich, D (reprint author), Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, POB 808, Livermore, CA 94551 USA. NR 8 TC 0 Z9 0 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 316 EP 321 DI 10.1088/1742-6596/46/1/044 PG 6 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300044 ER PT S AU Agarwal, PK Alam, SR AF Agarwal, Pratul K. Alam, Sadaf R. BE Tang, WM TI Biomolecular simulations on petascale: promises and challenges SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID MOLECULAR-DYNAMICS; PROTEIN DYNAMICS; CYCLOPHILIN-A; CATALYSIS; ISOMERIZATION; ENZYMES; PROGRAM; ENERGY AB Proteins work as highly efficient machines at the molecular level and are responsible for a variety of processes in all living cells. There is wide interest in understanding these machines for implications in biochemical/biotechnology industries as well as in health related fields. Over the last century, investigations of proteins based on a variety of experimental techniques have provided a wealth of information. More recently, theoretical and computational modeling using large scale simulations is providing novel insights into the functioning of these machines. The next generation supercomputers with petascale computing power, hold great promises as well as challenges for the biomolecular simulation scientists. We briefly discuss the progress being made in this area. C1 [Agarwal, Pratul K.; Alam, Sadaf R.] Oak Ridge Natl Lab, Div Math & Comp Sci, POB 2008, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Comp Biol Inst, POB 2008, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Future Tech Grp, POB 2008, Oak Ridge, TN 37831 USA. RP Agarwal, PK (reprint author), Oak Ridge Natl Lab, Div Math & Comp Sci, POB 2008, Oak Ridge, TN 37831 USA. EM agarwalpk@ornl.gov NR 17 TC 7 Z9 8 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 327 EP 333 DI 10.1088/1742-6596/46/1/046 PG 7 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300046 ER PT S AU Sanbonmatsu, KY Tung, CS AF Sanbonmatsu, K. Y. Tung, C. -S. BE Tang, WM TI Large-scale simulations of the ribosome: a new landmark in computational biology SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID MOLECULAR-DYNAMICS SIMULATIONS; TRANSFER-RNA; DARK-MATTER; PARALLEL; ALGORITHM; MECHANISM; PROGRAM; MODEL AB Within computational biology, all-atom simulation is the most computationally demanding field, in terms of compute load, communication speed, and memory load. Here, we report molecular dynamics simulation results for the ribosome, using 2.64 x 10(6) atoms, the largest all-atom biomolecular simulation published to date. The ribosome is the largest asymmetric biological structure solved to date to atomic resolution (2.8 angstrom). While simulations requiring long-range electrostatic forces have been previously restricted to much smaller systems, breakthroughs in electrostatic force calculation and dynamic load balancing have enabled molecular dynamics simulations of large biomolecular complexes. The LANL Q Machine played a key role in enabling such large simulations to be performed. The LANL Q machine displays approximately 85% parallel scaling efficiency for the ribosome system on 1024 CPUs. Using the targeted molecular dynamics algorithm, we have simulated the rate-limiting step in genetic decoding by the ribosome. The simulations use experimentally determined ribosome structures in different functional states as the initial and final conditions, making our simulations entirely and rigorously consistent with these experimental data. The simulations have identified candidate 23S rRNA nucleotides important for the accommodation of tRNA into the ribosome during protein synthesis. C1 [Sanbonmatsu, K. Y.; Tung, C. -S.] Los Alamos Natl Lab, Div Theoret, MS K710, Los Alamos, NM 87545 USA. RP Sanbonmatsu, KY (reprint author), Los Alamos Natl Lab, Div Theoret, MS K710, Los Alamos, NM 87545 USA. EM kys@lanl.gov FU LANL Institutional Computing, the LANL-LDRD program; NIH [R01-GM072686]; US Department of Energy [W-7405-ENG-36] FX We are grateful to Laura Monroe for assistance with visualization and the LANL Q machine committee, especially Andy White and Manuel Vigil. We acknowledge the important support of LANL Institutional Computing, the LANL-LDRD program and NIH grant R01-GM072686. This work was performed under the auspices of the US Department of Energy, and supported by its contract #W-7405-ENG-36 to Los Alamos National Laboratory. We thank Angel E. Garcia for useful discussions. NR 32 TC 5 Z9 5 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 334 EP 342 DI 10.1088/1742-6596/46/1/047 PG 9 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300047 ER PT S AU Cameron-Smith, P Lamarque, JF Connell, P Chuang, C Vitt, F AF Cameron-Smith, P. Lamarque, J-F Connell, P. Chuang, C. Vitt, F. BE Tang, WM TI Toward an Earth system model: atmospheric chemistry, coupling, and petascale computing SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB Atmospheric chemicals and aerosols are interactive components of the Earth system, with implications for climate. As part of the SciDAC climate consortium of labs we have implemented a flexible state-of-the-art atmospheric chemistry and aerosol capability into the Community Climate System Model (CCSM). We have also developed a fast chemistry mechanism that agrees well with observations and is computationally more efficient than our more complex chemistry mechanisms. We are working with other colleagues to couple this capability with the biospheric and aerosol-cloud interaction capabilities that are being developed for the CCSM model to create an Earth system model. However, to realise the potential of this Earth system model will require a move from terascale to petascale computing, and the greatest benefit will come from well balanced computers and a balance between capability and capacity computing. C1 [Cameron-Smith, P.; Connell, P.; Chuang, C.] Lawrence Livermore Natl Lab, 7000 E Ave, Livermore, CA 94550 USA. [Lamarque, J-F; Vitt, F.] Natl Ctr Atmospher Res, Boulder 80305, CO USA. RP Cameron-Smith, P (reprint author), Lawrence Livermore Natl Lab, 7000 E Ave, Livermore, CA 94550 USA. EM pjc@llnl.gov RI chuang, cathy/H-4814-2012; Cameron-Smith, Philip/E-2468-2011 OI Cameron-Smith, Philip/0000-0002-8802-8627 FU SciDAC program of the US Department of Energy's Office of Science through its Office of Biological and Environmental Research; U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory [W-7405-Eng-48] FX This work was supported by the SciDAC program of the US Department of Energy's Office of Science through its Office of Biological and Environmental Research. Part of this work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract No.W-7405-Eng-48. NR 2 TC 5 Z9 5 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 343 EP 350 DI 10.1088/1742-6596/46/1/048 PG 8 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300048 ER PT S AU Worley, P Mirin, A Drake, J Sawyer, W AF Worley, P. Mirin, A. Drake, J. Sawyer, W. BE Tang, WM TI Performance engineering in the community atmosphere model SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID VOLUME DYNAMICAL CORE; CLIMATE SYSTEM MODEL AB The Community Atmosphere Model (CAM) is the atmospheric component of the Community Climate System Model (CCSM) and is the primary consumer of computer resources in typical CCSM simulations. Performance engineering has been an important aspect of CAM development throughout its existence. This paper briefly summarizes these efforts and their impacts over the past five years. C1 [Worley, P.; Drake, J.] Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. [Mirin, A.] Lawrence Livemore Natl Lab, Livermore, CA 94551 USA. [Sawyer, W.] Swiss Fed Inst Technol, Z-8092 Zurich, Switzerland. RP Worley, P (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. EM worleyph@ornl.gov FU Office of Science of the U.S. Department of Energy [DE-AC05-00OR22725, DE-AC03-76SF00098]; U.S. Department of Energy by University of California Lawrence Livermore National Laboratory [W-7405-Eng-48]; LLNL [UCRL-CONF-221711]; NASA Goddard Space Flight Center, NASA [00-9103-01a] FX This research used resources (Cray X1E, Cray XT3, IBM p690 cluster) of the National Center for Computational Sciences at Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725. It used resources (IBM p575 cluster) of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC03-76SF00098. The work of Drake and Worley was supported by the Climate Change Research Division of the Office of Biological and Environmental Research and by the Office of Mathematical, Information, and Computational Sciences, both in the Office of Science, U.S. Department of Energy, under Contract No. DE-AC05-00OR22725 with UT-Batelle, LLC. The work of Mirin was performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48, and this paper is LLNL report UCRL-CONF-221711. The work of Sawyer was performed under the auspices of the NASA Goddard Space Flight Center, NASA Task 00-9103-01a. Accordingly, the U.S. Government retains a nonexclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for U.S. Government purposes. NR 14 TC 1 Z9 1 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 356 EP 362 DI 10.1088/1742-6596/46/1/050 PG 7 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300050 ER PT S AU Hoffman, F Fung, I Randerson, J Thornton, P Foley, J Covey, C John, J Levis, S Mac Post, W Vertenstein, M Stockli, R Running, S Heinsch, FA Erickson, D Drake, J AF Hoffman, Forrest Fung, Inez Randerson, Jim Thornton, Peter Foley, Jon Covey, Curtis John, Jasmin Levis, Samuel Mac Post, W. Vertenstein, Mariana Stockli, Reto Running, Steve Heinsch, Faith Ann Erickson, David Drake, John BE Tang, WM TI Terrestrial biogeochemistry in the community climate system model (CCSM) SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID VERSION-3 CCSM3; LAND MODEL; CARBON; CYCLE; SIMULATION; SINKS AB Described here is the formulation of the CASA ' biogeochemistry model of Fung, et al., which has recently been coupled to the Community Land Model Version 3 (CLM3) and the Community Climate System Model Version 3 (CCSM3). This model is presently being used for Coupled Climate/Carbon Cycle Model Intercomparison Project ((CMIP)-M-4) Phase 1 experiments. In addition, CASA ' is one of three models-in addition to CN (Thornton, et al.) and IBIS (Thompson, et al.)-that are being run within CCSM to investigate their suitability for use in climate change predictions in a future version of CCSM. All of these biogeochemistry experiments are being performed on the Computational Climate Science End Station (Dr. Warren Washington, Principle Investigator) at the National Center for Computational Sciences at Oak Ridge National Laboratory. C1 [Hoffman, Forrest; Mac Post, W.; Erickson, David; Drake, John] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. [Fung, Inez; John, Jasmin] Univ Calif Berkeley, Berkeley, CA USA. [Fung, Inez] Lawrence Berkeley Natl Lab, Berkeley, CA USA. [Randerson, Jim] Univ Calif Irvine, Irvine, CA USA. [Thornton, Peter; Levis, Samuel; Vertenstein, Mariana] Natl Ctr Atmospher Res, Boulder, CO USA. [Foley, Jon] Univ Wisconsin Madison, Madison, WI USA. [Covey, Curtis] Lawrence Livermore Natl Lab, Program Climate Model Diagnosis & Intercomparis, Livermore, CA USA. [Stockli, Reto] Colorado State Univ, Ft Collins, CO USA. [Running, Steve; Heinsch, Faith Ann] Univ Montana, Missoula, MT 59812 USA. RP Hoffman, F (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM forrest@climate.ornl.gov RI Thornton, Peter/B-9145-2012; Post, Wilfred/B-8959-2012; Hoffman, Forrest/B-8667-2012 OI Thornton, Peter/0000-0002-4759-5158; Hoffman, Forrest/0000-0001-5802-4134 NR 18 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 363 EP 369 DI 10.1088/1742-6596/46/1/051 PG 7 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300051 ER PT S AU Zingale, M Almgren, AS Bell, JB Day, MS Rendleman, CA Woosley, SE AF Zingale, M. Almgren, A. S. Bell, J. B. Day, M. S. Rendleman, C. A. Woosley, S. E. BE Tang, WM TI New approaches for modeling Type Ia supernovae SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID NUMERICAL SIMULATIONS; CARBON IGNITION; FLAMES; DETONATION; EXPLOSION; DEFLAGRATIONS AB Type Ia supernovae (SNe Ia) are the largest thermonuclear explosions in the Universe. Their light output can be seen across great distances and has led to the discovery that the expansion rate of the Universe is accelerating. Despite the significance of SNe Ia, there are still a large number of uncertainties in current theoretical models. Computational modeling offers the promise to help answer the outstanding questions. However, even with today's supercomputers, such calculations are extremely challenging because of the wide range of length and time scales. In this paper, we discuss several new algorithms for simulations of SNe Ia and demonstrate some of their successes. C1 [Zingale, M.] SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. [Almgren, A. S.; Bell, J. B.; Day, M. S.; Rendleman, C. A.] Ctr Computat Sci & Engn, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. [Woosley, S. E.] Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. RP Zingale, M (reprint author), SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. EM mzingale@mail.astro.sunysb.edu OI Zingale, Michael/0000-0001-8401-030X FU DOE to the Supernova Science Center/UCSC [DE-FC02-01ER41176]; Applied Mathematics Program of the DOE Office of Mathematics, Information, and Computational Sciences [DE-AC03-76SF00098]; Office of Science of the U.S. Department of Energy [DE-AC02-05CH11231] FX This work was supported by DOE grant No. DE-FC02-01ER41176 to the Supernova Science Center/UCSC and Applied Mathematics Program of the DOE Office of Mathematics, Information, and Computational Sciences under contract No. DE-AC03-76SF00098. The simulations presented were run on Columbia machine at NASA Ames and the jacquard machine at the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. NR 27 TC 4 Z9 4 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 385 EP 392 DI 10.1088/1742-6596/46/1/053 PG 8 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300053 ER PT S AU Bruenn, SW Dirk, CJ Mezzacappa, A Hayes, JC Blondin, JM Hix, WR Messer, OEB AF Bruenn, S. W. Dirk, C. J. Mezzacappa, A. Hayes, J. C. Blondin, J. M. Hix, W. R. Messer, O. E. B. BE Tang, WM TI Modeling core collapse supernovae in 2 and 3 dimensions with spectral neutrino transport SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID SIMULATIONS; INSTABILITY; MECHANISM; EQUATION; STARS; STATE AB The overwhelming evidence that the core collapse supernova mechanism is inherently multidimensional, the complexity of the physical processes involved, and the increasing evidence from simulations that the explosion is marginal presents great computational challenges for the realistic modeling of this event, particularly in 3 spatial dimensions. We have developed a code scalable to computations in 3 dimensions that couples PPM Lagrangian-with-remap hydrodynamics [1], multigroup flux-limited diffusion neutrino transport [2] (with many improvements), and a nuclear network [3]. The neutrino transport is performed in a "ray-by-ray-plus" approximation, wherein all the lateral effects of neutrinos are included (e.g., pressure, velocity corrections, advection) except lateral transport. A moving radial grid option permits the evolution to be carried out from initial core collapse with only modest demands on the number of radial zones. The inner part of the core is evolved after collapse, along with the rest of the core and mantle, by subcycling the lateral evolution near the center as demanded by the small Courant times. We present results of 2-D simulations of a symmetric and an asymmetric collapse of both a 15 and an 11 M circle dot progenitor. In each of these simulations we have discovered that once the oxygen-rich material reaches the shock there is a synergistic interplay between the reduced ram pressure, the energy released by the burning of the shock-heated oxygen-rich material, and the neutrino energy deposition that leads to a revival of the shock and an explosion. C1 [Bruenn, S. W.; Dirk, C. J.] Florida Atlantic Univ, Dept Phys, 777 W Glades Rd, Boca Raton, FL 33431 USA. [Mezzacappa, A.; Hix, W. R.] Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. [Hayes, J. C.] Univ Calif, Ctr Astrophys & Space Sci, La Jolla, CA 92093 USA. [Blondin, J. M.] North Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. [Messer, O. E. B.] Oak Ridge Natl Lab, Ctr Computat Sci, Oak Ridge, TN 37831 USA. RP Bruenn, SW (reprint author), Florida Atlantic Univ, Dept Phys, 777 W Glades Rd, Boca Raton, FL 33431 USA. RI Hix, William/E-7896-2011; Messer, Bronson/G-1848-2012; Mezzacappa, Anthony/B-3163-2017 OI Hix, William/0000-0002-9481-9126; Messer, Bronson/0000-0002-5358-5415; Mezzacappa, Anthony/0000-0001-9816-9741 FU DOE Office of Science Scientific Discovery through Advanced Computing Program FX The authors would like to acknowledge partial funded by a grant from the DOE Office of Science Scientific Discovery through Advanced Computing Program. NR 26 TC 48 Z9 48 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 393 EP 402 DI 10.1088/1742-6596/46/1/054 PG 10 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300054 ER PT S AU Duan, H Fuller, GM Carlson, J AF Duan, H. Fuller, G. M. Carlson, J. BE Tang, WM TI Simulations of coherent nonlinear neutrino flavor transformation in the core collapse supernova environment SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB We describe a set of codes developed under the auspices of the Terascale Supernova Initiative to simulate the coherent, nonlinear evolution of the neutrino and antineutrino fields in the core collapse supernova environment. Ours are the first simulations to include quantum entanglement of neutrino flavor evolution on different neutrino trajectories. We find that neutrinos and antineutrinos can undergo coherent, collective transformations of their flavors which could affect supernova dynamics and nucleosynthesis. C1 [Duan, H.; Fuller, G. M.] Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. [Carlson, J.] Los Alamos Natl lab, Theoret Div, Los Alamos, NM 87545 USA. RP Duan, H (reprint author), Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. EM hduan@ucsd.edu; gfuller@ucsd.edu; carlson@lanl.gov FU UC/LANL CARE; NSF [PHY-04-00359]; Terascale Supernova Initiative (TSI) collaboration's DOE SciDAC grant at UCSD; DOE at UMN [DE-FG02-87ER40328]; LDRD Program; Open Supercomputing at LANL; National Energy Research Scientific Computing Center through the TSI collaboration using Bassi; San Diego Supercomputer Center through the Academic Associates Program using DataStar FX This work was supported in part by a UC/LANL CARE grant, NSF grant PHY-04-00359, the Terascale Supernova Initiative (TSI) collaboration's DOE SciDAC grant at UCSD, and DOE grant DE-FG02-87ER40328 at UMN. This work was also supported in part by the LDRD Program and Open Supercomputing at LANL, and by the National Energy Research Scientific Computing Center through the TSI collaboration using Bassi, and the San Diego Supercomputer Center through the Academic Associates Program using DataStar. We would like to thank A. B. Balantekin, S. Bruenn, C. Y. CardaU, J. Hayes, W. Landry, O. E. B. Messer, A. Mezzacappa, M. Patel, and H. Yiiksel for valuable conversations. We would especially like to thank G. Raf- felt for a careful reading of the manuscript and many useful comments. NR 10 TC 1 Z9 1 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 418 EP 421 DI 10.1088/1742-6596/46/1/058 PG 4 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300058 ER PT S AU Hittinger, JAF Dorr, MR AF Hittinger, J. A. F. Dorr, M. R. BE Tang, WM TI Improving the capabilities of a continuum laser plasma interaction code SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID HYPERBOLIC CONSERVATION-LAWS; BEAMS; FILAMENTATION; SCHEMES; GODUNOV AB The numerical simulation of plasmas is a critical tool for inertial confinement fusion (ICF). We have been working to improve the predictive capability of a continuum laser plasma interaction code pF3d, which couples a continuum hydrodynamic model of an unmagnetized plasma to paraxial wave equations modeling the laser light. Advanced numerical techniques such as local mesh refinement, multigrid, and multifluid Godunov methods have been adapted and applied to nonlinear heat conduction and to multifluid plasma models. We describe these algorithms and briefly demonstrate their capabilities. C1 [Hittinger, J. A. F.; Dorr, M. R.] Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, POB 808,L-561, Livermore, CA 94551 USA. RP Hittinger, JAF (reprint author), Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, POB 808,L-561, Livermore, CA 94551 USA. EM hittinger1@llnl.gov; dorr1@llnl.gov FU NIF; U.S. Department of Energy by University of California; awrence Livermore National Laboratory [W-7405-Eng-48]; [UCRL-CONF-222175] FX We wish to thank our physics collaborators C. Still, R. Berger, L. Divol, B. Langdon, and E.Williams, and we thank the NIF Programs for funding our efforts. This work was performed under the auspices of the U.S. Department of Energy by University of California, Lawrence Livermore National Laboratory under Contract W-7405-Eng-48. UCRL-CONF-222175 NR 22 TC 1 Z9 1 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 422 EP 432 DI 10.1088/1742-6596/46/1/059 PG 11 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300059 ER PT S AU Keyes, DE Reynolds, DR Woodward, CS AF Keyes, David E. Reynolds, Daniel R. Woodward, Carol S. BE Tang, WM TI Implicit solvers for large-scale nonlinear problems SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID NONSYMMETRIC LINEAR-SYSTEMS; KRYLOV METHODS; NEWTON; CONVERGENCE; EQUATIONS AB Computational scientists are grappling with increasingly complex, multi-rate applications that couple such physical phenomena as fluid dynamics, electromagnetics, radiation transport, chemical and nuclear reactions, and wave and material propagation in inhomogeneous media. Parallel computers with large storage capacities are paving the way for high-resolution simulations of coupled problems; however, hardware improvements alone will not prove enough to enable simulations based on brute-force algorithmic approaches. To accurately capture nonlinear couplings between dynamically relevant phenomena, often while stepping over rapid adjustments to quasi-equilibria, simulation scientists are increasingly turning to implicit formulations that require a discrete nonlinear system to be solved for each time step or steady state solution. Recent advances in iterative methods have made fully implicit formulations a viable option for solution of these large-scale problems. In this paper, we overview one of the most effective iterative methods, Newton-Krylov, for nonlinear systems and point to software packages with its implementation. We illustrate the method with an example from magnetically confined plasma fusion and briefly survey other areas in which implicit methods have bestowed important advantages, such as allowing high-order temporal integration and providing a pathway to sensitivity analyses and optimization. Lastly, we overview algorithm extensions under development motivated by current SciDAC applications. C1 [Keyes, David E.] Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10027 USA. [Reynolds, Daniel R.] Univ Calif San Diego, Dept Math, La Jolla, CA 92093 USA. [Woodward, Carol S.] Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, POB 5508, Livermore, CA 94551 USA. RP Keyes, DE (reprint author), Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10027 USA. EM david.keyes@columbia.edu; drreynolds@ucsd.edu; cswoodward@llnl.gov RI Woodward, Carol/M-4008-2014; OI Reynolds, Daniel/0000-0002-0911-7841 FU U.S. Department of Energy by University of California Lawrence Livermore National Laboratory [W-7405-Eng-48] FX Work of this author was performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48. NR 21 TC 15 Z9 15 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 433 EP 442 DI 10.1088/1742-6596/46/1/060 PG 10 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300060 ER PT S AU Brannick, J Brezina, M Falgout, R Manteuffel, T McCormick, S Ruge, J Sheehan, B Xu, J Zikatanov, L AF Brannick, J. Brezina, M. Falgout, R. Manteuffel, T. McCormick, S. Ruge, J. Sheehan, B. Xu, J. Zikatanov, L. BE Tang, WM TI Extending the applicability of multigrid methods SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID SMOOTHED AGGREGATION; ACCELERATION METHOD; LEAST-SQUARES; ALGORITHMS; SPACE; AMGE AB Multigrid methods are ideal for solving the increasingly large-scale problems that arise in numerical simulations of physical phenomena because of their potential for computational costs and memory requirements that scale linearly with the degrees of freedom. Unfortunately, they have been historically limited by their applicability to elliptic-type problems and the need for special handling in their implementation. In this paper, we present an overview of several recent theoretical and algorithmic advances made by the TOPS multigrid partners and their collaborators in extending applicability of multigrid methods. Specific examples that are presented include quantum chromodynamics, radiation transport, and electromagnetics. C1 [Brannick, J.; Brezina, M.; Manteuffel, T.; McCormick, S.; Ruge, J.; Sheehan, B.] Univ Colorado, Dept Appl Math, Boulder, CO 80309 USA. [Falgout, R.] Lawrence Livermore Natl Lab, Ctr Appl & Sci Comp, POB 5508, Livermore, CA 94551 USA. [Xu, J.; Zikatanov, L.] Penn State Univ, Dept Math, University Pk, PA 16802 USA. RP Brannick, J (reprint author), Univ Colorado, Dept Appl Math, Boulder, CO 80309 USA. EM brannick1@llnl.gov; mbrezina@math.cudenver.edu; rfalgout@llnl.gov; tmanteuf@colorado.edu; stevem@colorado.edu; John.Ruge@colorado.edu; brendan.sheehan@colorado.edu; xu@psu.edu; ludmil@psu.edu RI Zikatanov, Ludmil/F-9365-2010 OI Zikatanov, Ludmil/0000-0002-5189-4230 FU U.S. Department of Energy by University of California Lawrence Livermore National Laboratory [W-7405-Eng-48] FX This work was performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48. NR 35 TC 5 Z9 5 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 443 EP 452 DI 10.1088/1742-6596/46/1/061 PG 10 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300061 ER PT S AU Bhowmick, S Boman, EG Devine, K Gebremedhin, A Hendrickson, B Hovland, P Munson, T Pothen, A AF Bhowmick, Sanjukta Boman, Erik G. Devine, Karen Gebremedhin, Assefaw Hendrickson, Bruce Hovland, Paul Munson, Todd Pothen, Alex BE Tang, WM TI Combinatorial algorithms enabling computational science: tales from the front SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB Combinatorial algorithms have long played a crucial enabling role in scientific and engineering computations. The importance of discrete algorithms continues to grow with the demands of new applications and advanced architectures. This paper surveys some recent developments in this rapidly changing and highly interdisciplinary field. C1 [Bhowmick, Sanjukta; Hovland, Paul; Munson, Todd] Argonne Natl Lab, Math & Comp Sci Div, Argonne, IL 60439 USA. [Boman, Erik G.; Devine, Karen; Hendrickson, Bruce] Sandia Natl Labs, Discrete Algorithems & Math Dept, Livermore, CA 94550 USA. [Gebremedhin, Assefaw; Pothen, Alex] Old Dominion Univ, Dept Comp Sci, Norfolk, VA 23529 USA. [Bhowmick, Sanjukta] Columbia Univ, Dept Appl Phys & Math, New York, NY 10027 USA. RP Bhowmick, S (reprint author), Argonne Natl Lab, Math & Comp Sci Div, Argonne, IL 60439 USA. EM bah@sandia.gov OI Pothen, Alex/0000-0002-3421-3325 FU U.S. Department of Energy [W-31-109-Eng-38] FX Sandia is a multiprogram laboratory operated by Sandia Corporation, a LockheedMartin Company, for the United States Department of Energys National Nuclear Security Administration under contract DE-AC04-94AL85000. The work at Argonne was supported by the Mathematical, Information, and Computational Sciences Division subprogram of theOffice of Advanced Scientific Computing Research, U.S. Department of Energy under Contract W-31-109-Eng-38. NR 11 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 453 EP 457 DI 10.1088/1742-6596/46/1/062 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300062 ER PT S AU Knupp, P AF Knupp, P. BE Tang, WM TI Mesh quality improvement for SciDAC applications SO SciDAC 2006: Scientific Discovery Through Advanced Computing SE JOURNAL OF PHYSICS CONFERENCE SERIES LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB Accurate and efficient numerical solution of partial differential equations requires well-formed meshes that are non-inverted, smooth, well-shaped, oriented, and size-adapted. The Mesquite mesh quality improvement toolkit is a software library that applies optimization algorithms to create well-formed meshes via node movement. Mesquite can be run stand-alone using drivers or called directly from an application code. Mesquite can play an essential role in the SLAG accelerator design program as a component in automatic shape optimization software and in manufacturing defect-correction studies to smoothly deform meshes in response to geometric domain deformations guided by the optimization of design parameters. Mesquite has also been applied to problems in fusion, biology, and propellant burn studies. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Knupp, P (reprint author), Sandia Natl Labs, MS 1111, Albuquerque, NM 87185 USA. NR 7 TC 5 Z9 5 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 458 EP 462 DI 10.1088/1742-6596/46/1/063 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300063 ER PT S AU Altintas, I Barney, O Cheng, ZG Critchlow, T Ludaescher, B Parker, S Shoshani, A Vouk, M AF Altintas, Ilkay Barney, Oscar Cheng, Zhengang Critchlow, Terence Ludaescher, Bertram Parker, Steve Shoshani, Arie Vouk, Mladen BE Tang, WM TI Accelerating the scientific exploration process with scientific workflows SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB Although an increasing amount of middleware has emerged in the last few years to achieve remote data access, distributed job execution, and data management, orchestrating these technologies with minimal overhead still remains a difficult task for scientists. Scientific workflow systems improve this situation by creating interfaces to a variety of technologies and automating the execution and monitoring of the workflows. Workflow systems provide domain-independent customizable interfaces and tools that combine different tools and technologies along with efficient methods for using them. As simulations and experiments move into the petascale regime, the orchestration of long running data and compute intensive tasks is becoming a major requirement for the successful steering and completion of scientific investigations. A scientific workflow is the process of combining data and processes into a configurable, structured set of steps that implement semi-automated computational solutions of a scientific problem. Kepler is a cross-project collaboration, co-founded by the SciDAC Scientific Data Management (SDM) Center, whose purpose is to develop a domain-independent scientific workflow system. It provides a workflow environment in which scientists design and execute scientific workflows by specifying the desired sequence of computational actions and the appropriate data flow, including required data transformations, between these steps. Currently deployed workflows range from local analytical pipelines to distributed, high-performance and high-throughput applications, which can be both data- and compute-intensive. The scientific workflow approach offers a number of advantages over traditional scripting-based approaches, including ease of configuration, improved reusability and maintenance of workflows and components (called actors), automated provenance management, "smart" re-running of different versions of workflow instances, on-the-fly updateable parameters, monitoring of long running tasks, and support for fault-tolerance and recovery from failures. We present an overview of common scientific workflow requirements and their associated features which are lacking in current state-of-the-art workflow management systems. We then illustrate features of the Kepler workflow system, both from a user's and a "workflow engineer's" point-of-view. In particular, we highlight the use of some of the current features of Kepler in several scientific applications, as well as upcoming extensions and improvements that are geared specifically for SciDAC user communities. C1 [Altintas, Ilkay] Univ Calif San Diego, San Diego Supercomp Ctr, La Jolla, CA 92093 USA. [Barney, Oscar; Parker, Steve] Univ Utah, Sci Comp & Imaging Inst, Salt Lake City, UT 84112 USA. [Cheng, Zhengang; Vouk, Mladen] North Carolina State Univ, Dept Comp Sci, Raleigh, NC 27695 USA. [Critchlow, Terence] Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94550 USA. [Ludaescher, Bertram] Univ Calif Davis, Dept Comp Sci, Davis, CA 95616 USA. [Shoshani, Arie] Lawrence Berkeley Natl Lab, Comp Res Div, Berkeley, CA 94720 USA. RP Altintas, I (reprint author), Univ Calif San Diego, San Diego Supercomp Ctr, La Jolla, CA 92093 USA. EM altintas@sdsc.edu; oscar@sci.utah.edu; zcheng@ncsu.edu; critchlow@llnl.gov; ludaesch@ucdavis.edu; sparker@cs.utah.edu; shoshani@lbl.gov; vouk@ncsu.edu FU DOE scientists; SDM Center; DOE SciDAC (SDM) [DE-FC02-01ER25486 (SDM), NSF/ITR 0225676 (SEEK), NSF/DBI-0078296, NSF/ SCI-0438741] FX The authors would like to thank the DOE scientists working with the SDM Center, especially to Matthew Coleman, Doug Swesty, Eric Myra, John Blondin and Scott Klasky, and the SDSC SWAT Lab team and the rest of the Kepler team for their excellent collaboration. This work is supported by DOE SciDAC DE-FC02-01ER25486 (SDM), NSF/ITR 0225676 (SEEK), NSF/DBI-0078296 (Resurgence) and NSF/ SCI-0438741 (Delivering Cyberinfrastructure: From Vision to Reality). NR 19 TC 5 Z9 5 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 468 EP 478 DI 10.1088/1742-6596/46/1/065 PG 11 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300065 ER PT S AU Kumfert, G Bernholdt, DE Epperly, TGW Kohl, JA McInnes, LC Parker, S Ray, J AF Kumfert, G. Bernholdt, D. E. Epperly, T. G. W. Kohl, J. A. McInnes, L. C. Parker, S. Ray, J. BE Tang, WM TI How the common component architecture advances computational science SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO ID SYSTEM MODELING FRAMEWORK; SOFTWARE; PARALLEL AB Computational chemists are using Common Component Architecture (CCA) technology to increase the parallel scalability of their application ten-fold. Combustion researchers are publishing science faster because the CCA manages software complexity for them. Both the solver and meshing communities in SciDAC are converging on community interface standards as a direct response to the novel level of interoperability that CCA presents. Yet, there is much more to do before component technology becomes mainstream computational science. This paper highlights the impact that the CCA has made on scientific applications, conveys some lessons learned from five years of the SciDAC program, and previews where applications could go with the additional capabilities that the CCA has planned for SciDAC 2. C1 [Kumfert, G.; Epperly, T. G. W.] Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. [Bernholdt, D. E.; Kohl, J. A.] Oak Ridge Natl Lab, Oak Ridge, TN USA. [McInnes, L. C.] Argonne Natl Lab, Argonne, IL 60439 USA. [Parker, S.] Univ Utah, Salt Lake City, UT 84112 USA. [Ray, J.] Sandia Natl Labs, Livermore, CA 94550 USA. RP Kumfert, G (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. EM kumfert@llnl.gov FU U.S. Department of Energy/Office of Science; Research at Argonne National Laboratory; Mathematical, Information; Computational Sciences Division; Office of Advanced Scientific Computing Research, Office of Science; U.S. Department of Energy [W-31-109-ENG-38]; U.S. Department of Energy by University of California Lawrence Livermore National Laboratory [W-7405-Eng-48]; US Dept. [DE-AC-05-00OR22725]; US Department of Energy (DOE); Office of Basic Energy Sciences (BES); SciDAC Computational Chemistry Program; United States Department of Energy [DE-AC04-94-AL85000]; Research at the University of Utah; National Science Foundation [ACI0113829]; DOE ASC Program FX This work was funded by the U.S. Department of Energy/Office of Sciences SciDAC program.; The CCA has been under development since 1998 by the CCA Forum and represents the contributions of many people, all of whom we gratefully acknowledge. We also thank our collaborators outside the CCA Forum, especially the researchers listed in Table 1, who took the time to contribute (and proof-read) their stories of how the CCA has affected their work.; Research at Argonne National Laboratory was supported in part by the Mathematical, Information, and Computational Sciences Division subprogram of the Office of Advanced Scientific Computing Research, Office of Science, U.S. Department of Energy, under Contract W-31-109-ENG-38.; Some of this work was performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.; Oak Ridge National Laboratory is managed by UT-Battelle, LLC for the US Dept. of Energy under contract DE-AC-05-00OR22725.; Research at Sandia National Laboratories was supported by the US Department of Energy (DOE), Office of Basic Energy Sciences (BES), SciDAC Computational Chemistry Program. Sandia National Laboratories is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94-AL85000.; Research at the University of Utah is also sponsored by the National Science Foundation under contract ACI0113829, and the DOE ASC Program. NR 72 TC 10 Z9 10 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 479 EP 493 DI 10.1088/1742-6596/46/1/066 PG 15 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300066 ER PT S AU Hargrove, PH Duell, JC AF Hargrove, Paul H. Duell, Jason C. BE Tang, WM TI Berkeley lab checkpoint/restart (BLCR) for Linux clusters SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB This article describes the motivation, design and implementation of Berkeley Lab Checkpoint/Restart (BLCR), a system-level checkpoint/restart implementation for Linux clusters that targets the space of typical High Performance Computing applications, including MPI. Application-level solutions, including both checkpointing and fault-tolerant algorithms, are recognized as more time and space efficient than system-level checkpoints, which cannot make use of any application-specific knowledge. However, system-level checkpointing allows for preemption, making it suitable for responding to "fault precursors" (for instance, elevated error rates from ECC memory or network CRCs, or elevated temperature from sensors). Preemption can also increase the efficiency of batch scheduling; for instance reducing idle cycles (by allowing for shutdown without any queue draining period or reallocation of resources to eliminate idle nodes when better fitting jobs are queued), and reducing the average queued time (by limiting large jobs to running during off-peak hours, without the need to limit the length of such jobs). Each of these potential uses makes BLCR a valuable tool for efficient resource management in Linux clusters. C1 [Hargrove, Paul H.; Duell, Jason C.] Univ Calif Berkeley, Lawrence Berkeley Lab, Computat Res Div, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RP Hargrove, PH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Computat Res Div, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM checkpoint@lbl.gov FU Office of Science, Office of Advanced Scientific Computing Research, U.S. Department of Energy [DE-AC02-05CH11231] FX This work was supported by the Director, Office of Science, Office of Advanced Scientific Computing Research, U.S. Department of Energy under Contract No. DE-AC02-05CH11231. NR 9 TC 74 Z9 75 U1 0 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 494 EP 499 DI 10.1088/1742-6596/46/1/067 PG 6 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300067 ER PT S AU Kamath, C AF Kamath, Chandrika BE Tang, WM TI Mining science data SO SciDAC 2006: Scientific Discovery Through Advanced Computing SE JOURNAL OF PHYSICS CONFERENCE SERIES LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB The data from scientific simulations, observations, and experiments are now being measured in terabytes and will soon reach the petabyte regime. The size of the data, as well as its complexity, make it difficult to find useful information in the data. This is of course disconcerting to scientists who wonder about the science still undiscovered in the data. The Sapphire scientific data mining project is addressing this concern by applying data mining techniques to problems ranging in size from a few megabytes to a hundred terabytes in a variety of domains. In this paper, we briefly describe our work in several applications, including the identification of key features for edge harmonic oscillations in the DIII-D tokamak, classification of orbits in a Poincare plot, and tracking of features of interest in experimental images. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Kamath, C (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 3 TC 1 Z9 1 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 500 EP 504 DI 10.1088/1742-6596/46/1/068 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300068 ER PT S AU Samatova, NF Branstetter, M Ganguly, AR Hettich, R Khan, S Kora, G Li, JT Ma, XS Pan, C Shoshani, A Yoginath, S AF Samatova, Nagiza F. Branstetter, Marcia Ganguly, Auroop R. Hettich, Robert Khan, Shiraj Kora, Guruprasad Li, Jiangtian Ma, Xiaosong Pan, Chongle Shoshani, Arie Yoginath, Srikanth BE Tang, WM TI High performance statistical computing with parallel R: applications to biology and climate modelling SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB Ultrascale computing and high-throughput experimental technologies have enabled the production of scientific data about complex natural phenomena. With this opportunity, comes a new problem - the massive quantities of data so produced. Answers to fundamental questions about the nature of those phenomena remain largely hidden in the produced data. The goal of this work: is to provide a scalable high performance statistical data analysis framework to help scientists perform interactive analyses of these raw data to extract knowledge. Towards this goal we have been developing an open source parallel statistical analysis package, called Parallel R, that lets scientists employ a wide range of statistical analysis routines on high performance shared and distributed memory architectures without having to deal with the intricacies of parallelizing these routines. C1 [Samatova, Nagiza F.; Branstetter, Marcia; Kora, Guruprasad; Ma, Xiaosong; Pan, Chongle; Yoginath, Srikanth] North Carolina State Univ, Comp Sci & Math Div, Raleigh, NC 27695 USA. [Ganguly, Auroop R.; Khan, Shiraj] North Carolina State Univ, Computat Sci & Engn Div, Raleigh, NC 27695 USA. [Hettich, Robert] North Carolina State Univ, Oak Ridge Natl Lab, Chem Sci Div, Raleigh, NC 27695 USA. [Li, Jiangtian; Ma, Xiaosong] North Carolina State Univ, Dept Comp Sci, Raleigh, NC 27695 USA. [Pan, Chongle] UTK, ORNL, Genome Sci & Technol Grad Sch, Knoxville, TN 37996 USA. [Shoshani, Arie] Lawrence Berkeley Natl Lab, Computat Res Div, Berkeley, CA 94720 USA. RP Samatova, NF (reprint author), North Carolina State Univ, Comp Sci & Math Div, Raleigh, NC 27695 USA. EM samatovan@ornl.gov FU DOE Scientific Data Management Center; Department of Energy [DOE-AC05-00OR22725] FX This work was funded by the DOE Scientific Data Management Center (http://sdmcenter.lbl.gov). Oak Ridge National Laboratory is managed by the University of Tennessee-Battelle, L.L.C. for the Department of Energy under contract DOE-AC05-00OR22725. NR 15 TC 3 Z9 3 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 505 EP 509 DI 10.1088/1742-6596/46/1/069 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300069 ER PT S AU Middleton, DE Bernholdt, DE Brown, D Chen, M Chervenak, AL Cinquini, L Drach, R Fox, P Jones, P Kesselman, C Foster, IT Nefedova, V Shoshani, A Sim, A Strands, WG Williams, D AF Middleton, D. E. Bernholdt, D. E. Brown, D. Chen, M. Chervenak, A. L. Cinquini, L. Drach, R. Fox, P. Jones, P. Kesselman, C. Foster, I. T. Nefedova, V. Shoshani, A. Sim, A. Strands, W. G. Williams, D. BE Tang, WM TI Enabling worldwide access to climate simulation data: the earth system grid (ESG) SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB With support from the U.S. Department of Energy's Scientific Discover Through Advanced Computing (SciDAC) program, we have developed and deployed the Earth System Grid (ESG) to make climate simulation data easily accessible to the global climate modelling and analysis community. ESG currently has 2500 registered users and manages 160 TB of data in archives distributed around the nation. From this past year alone, more than 200 scientific journal articles have been published from analyses of data delivered by the ESG. C1 [Middleton, D. E.] Argonne Natl Lab, Chicago, IL USA. [Jones, P.] Los Alamos Natl Lab, Los Alamos, NM USA. [Shoshani, A.; Sim, A.] Lawrence Berkeley Natl Lab, Berkeley, CA USA. [Drach, R.; Williams, D.] Lawrence Livermore Natl Lab, Livermore, CA USA. [Middleton, D. E.; Brown, D.; Cinquini, L.; Fox, P.; Strands, W. G.] Natl Ctr Atmospher Res, Boulder, CO USA. Natl Ocean & Atmospher Adm PMEL, Seattle, WA USA. [Chen, M.] Oak Ridge Natl Lab, Oak Ridge, TN USA. [Chervenak, A. L.; Kesselman, C.] Univ Southern California, Informat Sci Inst, Los Angeles, CA USA. RP Middleton, DE (reprint author), Argonne Natl Lab, Chicago, IL USA. EM don@ucar.edu OI Strand, Warren/0000-0001-9740-0104; Kesselman, Carl/0000-0003-0917-1562; Fox, Peter/0000-0002-1009-7163 NR 10 TC 6 Z9 6 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 510 EP 514 DI 10.1088/1742-6596/46/1/070 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300070 ER PT S AU Schopf, JM Pearlman, L Miller, N Kesselman, C Foster, I D'Arcy, M Chervenak, A AF Schopf, Jennifer M. Pearlman, Laura Miller, Neill Kesselman, Carl Foster, Ian D'Arcy, Mike Chervenak, Ann BE Tang, WM TI Monitoring the grid with the globus toolkit MDS4 SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB The Globus Toolkit Monitoring and Discovery System (MDS4) defines and implements mechanisms for service and resource discovery and monitoring in distributed environments. MDS4 is distinguished from previous similar systems by its extensive use of interfaces and behaviors defined in the WS-Resource Framework and WS-Notification specifications, and by its deep integration into essentially every component of the Globus Toolkit. We describe the MDS4 architecture and the Web service interfaces and behaviors that allow users to discover resources and services, monitor resource and service states, receive updates on current status, and visualize monitoring results. We present two current deployments to provide insights into the functionality that can be achieved via the use of these mechanisms. C1 [Schopf, Jennifer M.; Foster, Ian] Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. [Schopf, Jennifer M.; Miller, Neill; Foster, Ian] Univ Chicago, Dept Comp Sci, Chicago, IL 60637 USA. [Pearlman, Laura; Kesselman, Carl; D'Arcy, Mike; Chervenak, Ann] Univ Southern Calif, Informat Sci Insti, Los Angeles, CA USA. [Schopf, Jennifer M.] Univ Edinburgh, UK Natl eSci Ctr, Edinburgh EH8 9YL, Midlothian, Scotland. RP Schopf, JM (reprint author), Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RI D'Arcy, Michel/D-4848-2016; OI D'Arcy, Michel/0000-0003-2280-917X; Kesselman, Carl/0000-0003-0917-1562; Schopf, Jennifer/0000-0003-0726-3674 FU Mathematical, Information, and Computational Sciences Division subprogram of the Office of Advanced Scientific Computing Research; Office of Science, U.S. Department of Energy [W-31-109-Eng-38]; NSF NMI Award [SCI-0438372] FX Additional MDS support was provided by John Bresnahan, Mike Link, Eric Blau, and Mei-Hui Su. This work was supported in part by the Mathematical, Information, and Computational Sciences Division subprogram of the Office of Advanced Scientific Computing Research, Office of Science, U.S. Department of Energy, under contract W-31-109-Eng-38. Additional support was provided by NSF NMI Award SCI-0438372. NR 12 TC 22 Z9 23 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 521 EP 525 DI 10.1088/1742-6596/46/1/072 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300072 ER PT S AU Ahrens, J Heitmann, K Habib, S Ankeny, L McCormick, P Inman, J Armstrong, R Ma, KL AF Ahrens, James Heitmann, Katrin Habib, Salman Ankeny, Lee McCormick, Patrick Inman, Jeff Armstrong, Ryan Ma, Kwan-Liu BE Tang, WM TI Quantitative and comparative visualization applied to cosmological simulations SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB Cosmological simulations follow the formation of nonlinear structure in dark and luminous matter. The associated simulation volumes and dynamic range are very large, making visualization both a necessary and challenging aspect of the analysis of these datasets. Our goal is to understand sources of inconsistency between different simulation codes that are started from the same initial conditions. (quantitative visualization supports the definition and reasoning about analytically defined features of interest. Comparative visualization supports the ability to visually study, side by side, multiple related visualizations of these simulations. For instance, a scientist can visually distinguish that there are fewer halos (localized lumps of tracer particles) in low-density regions for one simulation code out of a collection. This qualitative result will enable the scientist to develop a hypothesis, such as loss of halos in low-density regions due to limited resolution, to explain the inconsistency between the different simulations. (quantitative support then allows one to confirm or reject the hypothesis. If the hypothesis is rejected, this step may lead to new insights and a new hypothesis, not available from the purely qualitative analysis. We will present methods to significantly improve the scientific analysis process by incorporating quantitative analysis as the driver for visualization. Aspects of this work are included as part of two visualization tools, ParaView, an open-source large data visualization tool, and Scout, an analysis-language based, hardware-accelerated visualization tool. C1 [Ahrens, James; Heitmann, Katrin; Habib, Salman; Ankeny, Lee; McCormick, Patrick; Inman, Jeff] Los Alamos Natl Lab, Los Alamos, NM 87545 USA. [Armstrong, Ryan; Ma, Kwan-Liu] Univ Calif Davis, Davis, CA USA. RP Ahrens, J (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EM ahrens@lanl.gov NR 9 TC 8 Z9 8 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 526 EP 534 DI 10.1088/1742-6596/46/1/073 PG 9 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300073 ER PT S AU Ahern, S Daniel, JR Gao, JZ Ostrouchov, G Toedte, RJ Wang, CL AF Ahern, Sean Daniel, Jamison R. Gao, Jinzhu Ostrouchov, George Toedte, Ross J. Wang, Chaoli BE Tang, WM TI Multi-scale data visualization for computational astrophysics and climate dynamics at Oak Ridge National Laboratory SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB Computational astrophysics and climate dynamics are two principal application foci at the Center for Computational Sciences (CCS) at Oak Ridge National Laboratory (ORNL). We identify a dataset frontier that is shared by several SciDAC computational science domains and present an exploration of traditional production visualization techniques enhanced with new enabling research technologies such as advanced parallel occlusion culling and high resolution small multiples statistical analysis. In collaboration with our research partners, these techniques will allow the visual exploration of a new generation of peta-scale datasets that cross this data frontier along all axes. C1 [Ahern, Sean; Daniel, Jamison R.; Gao, Jinzhu; Ostrouchov, George; Toedte, Ross J.; Wang, Chaoli] Oak Ridge Natl Lab, Ctr Comp Sci, POB 2008, Oak Ridge, TN 37831 USA. [Wang, Chaoli] Ohio State Univ, Dept Comp Sci, Columbus, OH 43210 USA. RP Ahern, S (reprint author), Oak Ridge Natl Lab, Ctr Comp Sci, POB 2008, Oak Ridge, TN 37831 USA. NR 10 TC 0 Z9 0 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 550 EP 555 DI 10.1088/1742-6596/46/1/076 PG 6 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300076 ER PT S AU Bremer, PT Cabot, W Cook, A Laney, D Mascarenhas, A Miller, P Pascucci, V AF Bremer, P. -T. Cabot, W. Cook, A. Laney, D. Mascarenhas, A. Miller, P. Pascucci, V. BE Tang, WM TI Understanding the structure of the turbulent mixing layer in hydrodynamic instabilities SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO DE topology; multi-resolution; Morse theory ID TRACKING; VISUALIZATION; TOPOLOGY; FLOWS AB When a heavy fluid is placed above a light fluid, tiny vertical perturbations in the interface create a characteristic structure of rising bubbles and falling spikes known as Rayleigh-Taylor instability. Rayleigh-Taylor instabilities have received much attention over the past half-century because of their importance in understanding many natural and man-made phenomena, ranging from the rate of formation of heavy elements in supernovae to the design of capsules for Inertial Confinement Fusion. We present a new approach to analyze Rayleigh-Taylor instabilities in which we extract a hierarchical segmentation of the mixing envelope surface to identify bubbles and analyze analogous segmentations of fields on the original interface plane. We compute meaningful statistical information that reveals the evolution of topological features and corroborates the observations made by scientists. C1 [Bremer, P. -T.; Cabot, W.; Cook, A.; Laney, D.; Mascarenhas, A.; Miller, P.; Pascucci, V.] Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. RP Bremer, PT (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. FU University of California Lawrence Livermore National Laboratory [W-7405-Eng-48, UCRL-JRNL-222696] FX The authors thank William Cabot and Andrew Cook for the datasets. This work was performed under the auspices of the US Department of Energy by University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48. UCRL-JRNL-222696 NR 26 TC 0 Z9 0 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 556 EP 560 DI 10.1088/1742-6596/46/1/077 PG 5 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300077 ER PT S AU Bethel, W Johnson, C Hansen, C Parker, S Sanderson, A Silva, C Tricoche, X Pascucci, V Childs, H Cohen, J Duchaineau, M Laney, D Lindstrom, P Ahern, S Meredith, J Ostrouchov, G Joy, K Hamann, B AF Bethel, W. Johnson, C. Hansen, C. Parker, S. Sanderson, A. Silva, C. Tricoche, X. Pascucci, V. Childs, H. Cohen, J. Duchaineau, M. Laney, D. Lindstrom, P. Ahern, S. Meredith, J. Ostrouchov, G. Joy, K. Hamann, B. BE Tang, WM TI VALET: Proposed SciDAC2 visualization and analytics center for enabling technologies SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO AB This project focuses on leveraging scientific visualization and analytics software technology as an enabling technology for increasing scientific productivity and insight. Advances in computational technology have resulted in an "information big bang," which in turn has created a significant data understanding challenge. This challenge is widely acknowledged to be one of the primary bottlenecks in contemporary science. The vision for our Center is to respond directly to that challenge by adapting, extending, creating when necessary and deploying visualization and data understanding technologies for our science stakeholders. Using an organizational model as a Visualization and Analytics Center for Enabling Technologies (VALET), we are well positioned to be responsive to the needs of a diverse set of scientific stakeholders in a coordinated fashion using a range of visualization, mathematics, statistics, computer and computational science and data management technologies. C1 [Bethel, W.] Lawrence Berkeley Lab, Berkeley, CA 94720 USA. [Johnson, C.; Hansen, C.; Parker, S.; Sanderson, A.; Silva, C.; Tricoche, X.] Univ Utah, Sci Comp & Imaging Inst, Salt Lake City, UT 84112 USA. [Pascucci, V.; Childs, H.; Cohen, J.; Duchaineau, M.; Laney, D.; Lindstrom, P.] Lawrence Livermore Natl Lab, Livermore, CA USA. [Ahern, S.; Meredith, J.; Ostrouchov, G.] Oak Ridge Natl Lab, Oak Ridge, TN USA. [Joy, K.; Hamann, B.] Univ Calif Davis, Davis, CA USA. RP Bethel, W (reprint author), Lawrence Berkeley Lab, Berkeley, CA 94720 USA. EM ewbethel@lbl.gov; crj@sci.utah.edu; hansen@sci.utah.edu; sparker@sci.utah.edu; allen@sci.utah.edu; csilva@sci.utah.edu; tricoche@sci.utah.edu; pascucci1@llnl.gov; childs3@llnl.gov; cohen22@llnl.gov; duchaineau1@llnl.gov; laney1@lllnl.gov; lindstrom2@llnl.gov; ahern@ornl.gov; jsmeredith@ornl.gov; ostrouchovg@ornl.gov; joy@cs.ucdavis.edu; hamann@cs.ucdavis.edu OI Lindstrom, Peter/0000-0003-3817-4199 FU Office of Science, Office of Advanced Scientific Computing Research, Mathematical, Information and Computational Sciences Division; U.S. Department of Energy [DE-AC03-76SF00098 (UC/LBNL), DE-AC05-00OR2275 (UTBatelle/ORNL), W-7405-Eng-48 (UC/LLNL), DE-FG02-04ER25653, B524196, DE-FC02-01ER25493, DE-FC02-04ER25643]; NIH; NSF (Utah) FX This work was supported by the Office of Science, Office of Advanced Scientific Computing Research, Mathematical, Information and Computational Sciences Division under the U.S. Department of Energy contracts DE-AC03-76SF00098 (UC/LBNL), DE-AC05-00OR2275 (UTBatelle/ORNL); W-7405-Eng-48 (UC/LLNL); DE-FC02-01ER25457, DE-FG02-04ER25653, B524196, DE-FC02-01ER25493, DE-FC02-04ER25643, as well as by awards from NIH and NSF (Utah). NR 20 TC 1 Z9 1 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 561 EP 569 DI 10.1088/1742-6596/46/1/078 PG 9 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300078 ER PT S AU Huang, J Liu, HD Beck, M Gao, JZ Moore, T AF Huang, Jian Liu, Huadong Beck, Micah Gao, Jinzhu Moore, Terry BE Tang, WM TI A distributed execution environment for large data visualization SO SCIDAC 2006: SCIENTIFIC DISCOVERY THROUGH ADVANCED COMPUTING SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 2nd Annual Scientific Discovery Through Advanced Computing Conference (SciDAC 2006) CY JUN 25-29, 2006 CL Denver, CO DE visualization; parallel and distributed volume visualization; distributed visualization; distributed computing; resource allocation/scheduling; testbed and deployment AB Over the years, homogeneous computer cluster have been the most popular, and, in some sense, the only viable, platform for use in parallel visualization. In this work, we designed an execution environment for data-intensive visualization that is suitable to handle SciDAC scale datasets. This environment is solely based on computers distributed across the Internet that are owned and operated by independent institutions, while being openly shared for free. Those Internet computers are inherently of heterogeneous hardware configuration and running a variety of operating systems. Using 100 processors of such kind, we have been able to obtain the same level of performance offered by a 64-node cluster of 2.2 GHz P4 processors, while processing a 75GBs subset of TSI simulation data. Due to its inherently shared nature, this execution environment for data-intensive visualization could provide a viable means of collaboration among geographically separated SciDAC scientists. C1 [Huang, Jian; Liu, Huadong; Beck, Micah; Moore, Terry] Univ Tennessee, Dept Comp Sci, Knoxville, TN 37996 USA. [Gao, Jinzhu] Oak Ridge Natl Lab, Oak Ridge, TN USA. RP Huang, J (reprint author), Univ Tennessee, Dept Comp Sci, Knoxville, TN 37996 USA. FU NSF [CNS-0437508]; TSI FX This work was supported in part by NSF grant CNS-0437508. The authors thank the TSI project for motivating our research and providing our main test datasets. We also thank Larry Peterson for PlanetLab access. NR 12 TC 2 Z9 2 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 46 BP 570 EP 576 DI 10.1088/1742-6596/46/1/079 PG 7 WC Computer Science, Interdisciplinary Applications; Multidisciplinary Sciences SC Computer Science; Science & Technology - Other Topics GA BFD53 UT WOS:000241186300079 ER PT J AU Ekimov, EA Sidorov, VA Rakhmanina, AV Mel'nik, NN Sadykov, RA Thompson, JD AF Ekimov, E. A. Sidorov, V. A. Rakhmanina, A. V. Mel'nik, N. N. Sadykov, R. A. Thompson, J. D. TI High-pressure synthesis and characterization of superconducting boron-doped diamond SO SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS LA English DT Article; Proceedings Paper CT International Workshop on Superconductivity in Diamond and Related Materials CY DEC 07-09, 2005 CL Natl Inst Mat Sci, Tsukuba, JAPAN HO Natl Inst Mat Sci DE diamond; boron; doping; synthesis; superconductivity; pressure ID TEMPERATURE AB Microcrystalline powders of boron-doped diamond were produced in the C-H-B system under a pressure of 8 GPa and at a temperature of more than 2000 K. The presence of boron in the C-B-H system was shown to decrease the temperature pressure parameters for diamond synthesis compared with those for the binary C-H system (naphthalene). A decrease in the parameters for synthesis in the system with boron may be due to the formation of graphite with less perfect crystal structure during an intermediate stage of diamond formation. Superconducting diamond microcrystals are synthesized in the C-H-B system with boron content of about 5-10 at% in a mixture with naphthalene. Superconductivity below 3.5 K in boron-doped diamond powder is detected in AC magnetic susceptibility measurements. (c) 2006 NIMS and Elsevier Ltd. All rights reserved. C1 Russian Acad Sci, Vereshchagin Inst High Pressure Phys, Troitsk 142190, Moscow Region, Russia. Russian Acad Sci, Lebedev Phys Inst, Moscow 117924, Russia. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Ekimov, EA (reprint author), Russian Acad Sci, Vereshchagin Inst High Pressure Phys, Troitsk 142190, Moscow Region, Russia. EM ekimov@ns.hppi.troitsk.ru RI Melnik, Nikolay/E-5666-2014 OI Melnik, Nikolay/0000-0002-7058-0333 NR 13 TC 15 Z9 15 U1 1 U2 6 PU NATL INST MATERIALS SCIENCE PI IBARAKI PA NATL INST MATERIALS SCIENCE, 1-2-1 SENGEN, TSUKUBA-CITY, IBARAKI, 305-0047, JAPAN SN 1468-6996 J9 SCI TECHNOL ADV MAT JI Sci. Technol. Adv. Mater. PY 2006 VL 7 SI 1 BP S2 EP S6 DI 10.1016/j.stam.2006.03.004 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA 124QZ UT WOS:000243386300002 ER PT J AU Sidorov, VA Ekimov, EA Rakhmanina, A Stishov, SM Bauer, ED Thompson, JD AF Sidorov, V. A. Ekimov, E. A. Rakhmanina, An. Stishov, S. M. Bauer, E. D. Thompson, J. D. TI Superconducting and normal state properties of heavily hole-doped diamond synthesized at high pressure SO SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS LA English DT Article; Proceedings Paper CT International Workshop on Superconductivity in Diamond and Related Materials CY DEC 07-09, 2005 CL Natl Inst Mat Sci, Tsukuba, JAPAN HO Natl Inst Mat Sci DE diamond; boron; superconductivity; pressure; specific heat; tunneling ID METAL-INSULATOR-TRANSITION AB Diamonds, synthesized at high pressures and high temperatures in the presence of boron, are heavily hole-doped by incorporation of boron into the diamond lattice. These diamonds become superconducting below T-c = 2-9 K. Synthesis in the systems B-C and B4C-C at P = 9 GPa and T = 2500-2800 K result in formation of polycrystalline carbonado-like material, whereas synthesis from B-C-H gives small single crystals and intergrowth plates. Dense superconducting bodies can be prepared by compacting these single crystal particles at P = 8 GPa and T = 1800 K. Specific heat and resistivity measurements in magnetic fields prove the bulk nature of superconductivity in all pressure-synthesized samples and provide a consistent set of materials parameters that favor a conventional weak-coupling electron-phonon interpretation of the superconducting mechanism at high hole doping. Schottky barrier tunneling conductance spectra, obtained with contacts fabricated at the surface of these hole-doped diamonds, indicate the appearance of superconducting gap below T-c. (c) 2006 NIMS and Elsevier Ltd. All rights reserved. C1 Russian Acad Sci, Vereshchagin Inst High Pressure Phys, Troitsk 142190, Moscow Region, Russia. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Sidorov, VA (reprint author), Russian Acad Sci, Vereshchagin Inst High Pressure Phys, Troitsk 142190, Moscow Region, Russia. EM sidorov@hppi.troitsk.ru RI Bauer, Eric/D-7212-2011; OI Bauer, Eric/0000-0003-0017-1937 NR 19 TC 5 Z9 5 U1 1 U2 5 PU NATL INST MATERIALS SCIENCE PI IBARAKI PA NATL INST MATERIALS SCIENCE, 1-2-1 SENGEN, TSUKUBA-CITY, IBARAKI, 305-0047, JAPAN SN 1468-6996 J9 SCI TECHNOL ADV MAT JI Sci. Technol. Adv. Mater. PY 2006 VL 7 SI 1 BP S7 EP S11 DI 10.1016/j.stam.2006.03.005 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA 124QZ UT WOS:000243386300003 ER PT S AU Ueno, S Jayaseelan, DD Kita, H Ohji, T Lin, HT AF Ueno, Shunkichi Jayaseelan, D. Doni Kita, Hideki Ohji, Tatsuki Lin, Hua-Tay BE Ohji, T Sekino, T Niihara, K TI Comparison of water vapor corrosion behaviors of Ln(2)Si(2)O(7) (Ln=Yb and Lu) and ASiO(4) (A=Ti, Zr and Hf) EBC's SO SCIENCE OF ENGINEERING CERAMICS III SE KEY ENGINEERING MATERIALS LA English DT Article; Proceedings Paper CT 3rd International Symposium on the Science of Engineering Ceramics (EnCera 2004) CY OCT 31-NOV 03, 2004 CL Osaka, JAPAN SP Ceram Soc Japan, Japan Soc Promot Sci, Korea Sci & Engn Fdn, Amer Ceram Soc, Canadian Ceram Soc, European Ceram Soc, Korean Ceram Soc, Carbon Soc Japan, High Temp Soc Japan, Soc Powder Technol, Japan Soc Powder & Powder Met, Japan Soc Mech Engineers, Australasian Ceram Soc, Chinese Ceram Soc, Indian Ceram Soc, Chem Soc Japan, Soc Mat Sci, Japan Soc Composite Mat, Japan Inst Met DE EBC; silicon nitride; rare earth di-silicate; hafrion; zircon ID OXIDATION AB The corrosion behaviors of Ln(2)Si(2)O(7) (Ln=Yb and Lu) and ASiO(4) (A=Ti, Zr and Ht) EBC's were examined at 1500 degrees C in water vapor environment. These oxides were coated on silicon nitride specimens by oxidation-bonded reaction sintering technique. Among Ln(2)Si(2)O(7) system, though the thermal expansion coefficient of Yb2Si2O7 phase is closer to silicon nitride than that of Lu2Si2O7 phase, the corrosion resistance of silicon nitride with Lu2Si2O7 EBC was higher than that of Yb2Si2O7 EBC sample. In these EBC materials, boundary silica phase was easily corroded by water vapor. Among ASiO(4) system, though the corrosion rate of HfSiO4 bulk was larger than that of ZrSiO4 and TiSiO4 phases, the oxidation of the silicon nitride substrate for HtSiO(4) coated sample was smaller than that of other two. Many cracks were in ASiO(4) EBC layer during the corrosion test. The introduced crack length in HfSiO4 EBC layer is shorter than in ZrSiO4 EBC layer due to the thermal expansion mismatch between EBC materials and the silicon nitride substrate. C1 AIST, Adv Mfg Res Inst, Moriyama Ku, Nagoya, Aichi 4638560, Japan. Oak Ridge Natl Lab, Mat & Ceram Div, Oak Ridge, TN 37831 USA. RP Ueno, S (reprint author), AIST, Adv Mfg Res Inst, Moriyama Ku, 2266-98 Shimo Shidami, Nagoya, Aichi 4638560, Japan. EM shunkichi.ueno@aist.go.jp; daniel-doni@aist.go.jp; hideki-kita@aist.go.jp; t_ohji@aist.go.jp; linh@ornl.gov; t_ohji@aist.go.jp NR 8 TC 6 Z9 6 U1 3 U2 4 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 1013-9826 BN 0-87849-401-4 J9 KEY ENG MAT PY 2006 VL 317-318 BP 557 EP 560 PG 4 WC Materials Science, Ceramics; Materials Science, Composites SC Materials Science GA BEY26 UT WOS:000240097700131 ER PT B AU Earle, OK AF Earle, OK BE Sarkisov, A DuClos, AT TI A perspective on US spent nuclear fuel policy SO Scientific and Technical Issues in the Management of Spent Fuel of Decommissioned Nuclear Submarines SE NATO SCIENCE SERIES, SERIES II: MATHEMATICS, PHYSICS AND CHEMISTRY LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Scientific and Technical Issues in the Managaement of Spent Fuel CY SEP 22-24, 2004 CL Moscow, RUSSIA SP NATO AB This submitted manuscript has been created by the University of Chicago as Operator of Argonne National Laboratoty ("Argonne') under contract No. W-31-109-ENG-38 with the US. Department of Energy. The US. government retains for itself, and others acting on its behalf a paid-tip nonexclusive, irrevocable worldwide license in said article to reproduce, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, by or on behalf of the Government. C1 Argonne Natl Lab, Nucl Technol Div, Argonne, IL 60439 USA. RP Earle, OK (reprint author), Argonne Natl Lab, Nucl Technol Div, Argonne, IL 60439 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-4171-3 J9 NATO SCI SER II MATH PY 2006 VL 215 BP 99 EP 106 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA BED11 UT WOS:000236857800009 ER PT S AU Pankratov, DV Ignatiev, CV Toshinskiy, GI Zabud'ko, AN Andreyanov, VS Riabaya, LD Suvorov, GP Khvostov, PV Khudlkkov, EM Filatov, BV Vishniakov, BS Il'in, VG Kozhevnikov, YM Moscowitz, PD AF Pankratov, DV Ignatiev, CV Toshinskiy, GI Zabud'ko, AN Andreyanov, VS Riabaya, LD Suvorov, GP Khvostov, PV Khudlkkov, EM Filatov, BV Vishniakov, BS Il'in, VG Kozhevnikov, YM Moscowitz, PD BE Sarkisov, A DuClos, AT TI Nuclear and radiation safety during long-term storage of Spent Nuclear Fuel of land-based reactor facility stands-prototypes 27/VT and KM-1 SO SCIENTIFIC AND TECHNICAL ISSUES IN THE MANAGEMENT OF SPENT FUEL OF DECOMMISSIONED NUCLEAR SUBMARINES SE NATO Science Series II-Mathematics Physics and Chemistry LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Scientific and Technical Issues in the Managaement of Spent Fuel CY SEP 22-24, 2004 CL Moscow, RUSSIA SP NATO AB Within the framework of the ISTC Project #2710p between the Russian Research Center "Institute for Physics and Power Engineering" (RRC IPPE, below IPPE) and the Brookhaven National Laboratory of the US Department of Energy an investigation has been performed addressing the issues of nuclear and radiation safety when storing Spent Nuclear Fuel (SNF) of land-based stands-prototypes 27/VT and KM-1 constructed during the period of developing lead-bismuth coolant reactor installations for Alpha-class Nuclear Submarines (NS). The detailed results of the investigation can be found in the Final Report under this Project [1]. This paper presents the main results of the study with a focus on: -examination of the effects on the system reactivity of moisture ingress into storage facility of the Spent removable Unit (SRU) of KM-1 stand and -analysis of potential implications of their resulting emergency situations. On this basis health radiation risk assessments for population of the nearby territories, including Finland, Estonia and Latvia, have been performed. C1 Russian Res Ctr IPPE, Obninsk, Russia. NITI, Sosnovyi Bor, Russia. Brookhaven Natl Lab, Upton, NY USA. RP Russian Res Ctr IPPE, Obninsk, Russia. NR 8 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 1568-2609 BN 1-4020-4171-3 J9 NATO SCI SER II-MATH PY 2006 VL 215 BP 179 EP 194 PG 16 WC Nuclear Science & Technology SC Nuclear Science & Technology GA BED11 UT WOS:000236857800017 ER PT S AU Veith, GM Lupini, AR Pennycook, SJ Dudney, NJ AF Veith, Gabriel M. Lupini, Andrew R. Pennycook, Stephen J. Dudney, Nancy J. BE Gaigneaux, EM Devillers, M De Vos, DE Hermans, S Jacobs, PA Martens, JA Ruiz, P TI The use of Magnetron Sputtering for the Production of Heterogeneous Catalysts SO SCIENTIFIC BASES FOR THE PREPARATION OF HETEROGENEOUS CATALYSTS, PROCEEDINGS OF THE 9TH INTERNATIONAL SYMPOSIUM SE Studies in Surface Science and Catalysis LA English DT Proceedings Paper CT 9th International Symposium on the Scientific Bases for the Preparation of Heterogeneous Catalysts CY SEP 10-14, 2006 CL Univ Cathol Louvain (UCL), Louvain-la-Neuve, BELGIUM HO Univ Cathol Louvain (UCL) ID TEMPERATURE CO OXIDATION; GOLD CATALYSTS C1 [Veith, Gabriel M.; Lupini, Andrew R.; Pennycook, Stephen J.; Dudney, Nancy J.] Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RP Veith, GM (reprint author), Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RI Dudney, Nancy/I-6361-2016 OI Dudney, Nancy/0000-0001-7729-6178 NR 13 TC 8 Z9 8 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 978-0-444-52827-8 J9 STUD SURF SCI CATAL PY 2006 VL 162 BP 71 EP 78 DI 10.1016/S0167-2991(06)80892-X PG 8 WC Chemistry, Physical SC Chemistry GA BRS86 UT WOS:000283580900010 ER PT S AU Bryan, C Jarek, R Wolery, T Shields, D Sutton, M Hardin, E Barr, D AF Bryan, Charles Jarek, Russell Wolery, Thomas Shields, David Sutton, Mark Hardin, Ernest Barr, Deborah BE VanIseghem, P TI Evaluation of the corrosivity of dust deposited on waste packages at Yucca Mountain, Nevada SO Scientific Basis for Nuclear Waste Management XXIX SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 29th International Symposium on the Scientific Basis for Nuclear Waste Management CY SEP 12-16, 2005 CL Ghent, BELGIUM SP Mat Res Soc AB Potentially corrosive brines can form during post-closure by deliquescence of salt minerals in dust deposited on the surface of waste packages at Yucca Mountain during operations and the pre-closure ventilation period. Although thermodynamic modeling and experimental studies of brine deliquescence indicates that brines are likely to form, they will be nitrate-rich and non-corrosive. Processes that modify the brines following deliquescence are beneficial with respect to inhibition of corrosion. For example, acid degassing (HCl, HNO3) could dry out brines, but kinetic limitations are likely to limit the effect to increasing their passivity by raising the pH and increasing the NO3/Cl ratio. Predicted dust quantities and maximum brine volumes on the waste package surface are small, and physical isolation of salt minerals in the dust may inhibit formation of eutectic brines and decrease brine volumes. If brines do contact the WT surface, small droplet volumes and layer thicknesses do not support development of diffusive gradients necessary for formation on separate anodic-cathodic zones required for localized corrosion. Finally, should localized corrosion initiate, corrosion product buildup will stifle corrosion, by limiting oxygen access to the metal surface, by capillary retention of brine in corrosion product porosity, or by consumption of brine components (Cl-). C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Bryan, C (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 15 TC 0 Z9 0 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-889-6 J9 MATER RES SOC SYMP P PY 2006 VL 932 BP 191 EP 198 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA BER14 UT WOS:000239003700022 ER PT B AU Gilmore, DK AF Gilmore, D. Kirk BE Beletic, JE Beletic, JW Amico, P TI THE LARGE SYNOPTIC SURVEY TELESCOPE - My instrument is bigger than yours SO Scientific Detectors for Astronomy 2005: EXPLORERS OF THE PHOTON ODYSSEY SE ASTROPHYSICS AND SPACE SCIENCE LIBRARY LA English DT Proceedings Paper CT Workshop on Scientific Detectors for Astronomy CY JUN 19-25, 2005 CL Taormina, ITALY SP e2v technologies, GL Sci, Ist Nazl Astrofis, Raytheon Vis Syst, Rockwell Sci Co, ST Microelect, Fairchild Imaging, Hitec2000, Medianet Comunicazioni, Reg Siciliana, SciMeasure Analyt Syst, Univ Catania DE LSST; largefocal plane; dark matter; survey AB The Large Synoptic Survey Telescope (LSST) will be a wide-field telescope facility that will add a new capability to astronomy. The LSST will provide unprecedented 3-dimensional maps of mass distribution in the Universe, in addition to traditional images of luminous stars and galaxies. These mass maps can he used to better understand the nature of the newly discovered and mysterious "dark energy" that is driving the accelerating expansion of the Universe. By looking at the entire accessible sky every few nights, the LSST will provide large samples of events that we now only rarely observe and will create substantial potential for new discoveries. The LSST telescope, with its 8.5 in primary mirror and fast f/1.25, 3-mirror design, offers unique design challenges driven by requirements for fast "slew and settle" time, tracking accuracy, and tight alignment tolerances. It must be possible to point the telescope quickly (< 5 see) and repeatedly to adjacent field locations. The LSST camera is a wide-field optical (0.35-1 mu m) imager designed to provide a 3.5 degree FOV with better than 0.2 arcsecond sampling. The detector format will be a circular mosaic providing approximately 3.2 Gigapixels per image. The camera includes a filter mechanism and shuttering capability. It is positioned in the middle of the telescope where cross-section area is constrained by optical vignetting and heat dissipation must be controlled to limit thermal gradients in the optical beam. The LSST will produce the largest non-proprietary data set in the world, and this data set will be made accessible through the Virtual observatory (VO). The "open data" approach, with no proprietary data or science, is a precedent-setting aspect of the LSST project. C1 Stanford Linear Accelerator Ctr, Kavli Inst Particle Astrophys & Cosmol, Stanford, CA 94305 USA. RP Gilmore, DK (reprint author), Stanford Linear Accelerator Ctr, Kavli Inst Particle Astrophys & Cosmol, Stanford, CA 94305 USA. NR 2 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-4329-5 J9 ASTROPHYS SPACE SC L PY 2006 VL 336 BP 63 EP 72 DI 10.1007/1-4020-4330-9_5 PG 10 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BEK77 UT WOS:000237613100005 ER PT S AU Kolbe, WF Holland, SE Bebek, CJ AF Kolbe, William F. Holland, Steve E. Bebek, Christopher J. BE Beletic, JE Beletic, JW Amico, P TI CCD development progress at Lawrence Berkeley National Laboratory SO SCIENTIFIC DETECTORS FOR ASTRONOMY 2005: EXPLORERS OF THE PHOTON ODYSSEY SE Astrophysics and Space Science Library LA English DT Proceedings Paper CT Workshop on Scientific Detectors for Astronomy CY JUN 19-25, 2005 CL Taormina, ITALY SP e2v technologies, GL Sci, Ist Nazl Astrofis, Raytheon Vis Syst, Rockwell Sci Co, ST Microelect, Fairchild Imaging, Hitec2000, Medianet Comunicazioni, Reg Siciliana, SciMeasure Analyt Syst, Univ Catania DE fully-depleted; back-illuminated; p-channel; IR response; high voltage; PSF ID HIGH-RESISTIVITY SILICON; CHARGE-COUPLED-DEVICES AB P-channel CCD imagers, 200-300 mu m thick fully depleted, and back-illuminated are being developed for scientific applications including ground-and space-based astronomy and x-ray detection. These thick devices have extended IR response, good Point-Spread Function (PSF) and excellent radiation tolerance. Initially, these CCDs were made in-house at LBNL using 100 mm diameter wafers. Fabrication on high-resistivity 150 mm wafers is now proceeding according to a model in which the wafers are first processed at DALSA Semiconductor up to the Al contact mask step. They are then thinned and the remaining processing is done in small batches at LBNL. Alternative approaches are also discussed In addition we have implemented designs that permit high-voltage biasing to further improve the PSF. With these designs, operation of 200 mu m thick CCDs at 100 V or more bias with excellent PSF is practical. C1 [Kolbe, William F.; Holland, Steve E.; Bebek, Christopher J.] Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Kolbe, WF (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. EM wfkolbe@lbl.gov NR 8 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0067-0057 BN 1-4020-4329-5 J9 ASTROPHYS SPACE SC L PY 2006 VL 336 BP 273 EP + DI 10.1007/1-4020-4330-9_30 PG 2 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BEK77 UT WOS:000237613100030 ER PT S AU Estrada, J Schmidt, RE AF Estrada, Juan Schmidt, Ricardo E. BE Beletic, JE Beletic, JW Amico, P TI Focal plane detectors for the dark energy survey SO SCIENTIFIC DETECTORS FOR ASTRONOMY 2005: EXPLORERS OF THE PHOTON ODYSSEY SE Astrophysics and Space Science Library LA English DT Proceedings Paper CT Workshop on Scientific Detectors for Astronomy CY JUN 19-25, 2005 CL Taormina, ITALY SP e2v technologies, GL Sci, Ist Nazl Astrofis, Raytheon Vis Syst, Rockwell Sci Co, ST Microelect, Fairchild Imaging, Hitec2000, Medianet Comunicazioni, Reg Siciliana, SciMeasure Analyt Syst, Univ Catania DE Dark Energy Survey (DES); CCD; mosaic AB The scientific requirements of the focal plane array for the Dark Energy Survey (DES) are reviewed. The status and plans for CCD testing and characterization for this project are presented. C1 [Estrada, Juan] Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Cerro Tololo Inter American Observatory, La Serena, Chile. RP Estrada, J (reprint author), Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. EM rschmidt@ctio.noao.edu NR 2 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0067-0057 BN 1-4020-4329-5 J9 ASTROPHYS SPACE SC L PY 2006 VL 336 BP 361 EP + DI 10.1007/1-4020-4330-9_40 PG 3 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BEK77 UT WOS:000237613100040 ER PT S AU Karcher, A Bebek, CJ Fabricius, M Krieger, B Von Der Lippe, H Redelstab, M Walder, JP AF Karcher, Armin Bebek, Christopher J. Fabricius, Maximilian Krieger, Brad von der Lippe, Hendrik Redelstab, Markus Walder, Jean Pierre BE Beletic, JE Beletic, JW Amico, P TI INTEGRATING SIGNAL PROCESSING AND A/D CONVERSION INONE FOCAL PLANE MOUNTED ASIC - Turning photons into bits in the cold SO SCIENTIFIC DETECTORS FOR ASTRONOMY 2005: EXPLORERS OF THE PHOTON ODYSSEY SE Astrophysics and Space Science Library LA English DT Proceedings Paper CT Workshop on Scientific Detectors for Astronomy CY JUN 19-25, 2005 CL Taormina, ITALY SP e2v technologies, GL Sci, Ist Nazl Astrofis, Raytheon Vis Syst, Rockwell Sci Co, ST Microelect, Fairchild Imaging, Hitec2000, Medianet Comunicazioni, Reg Siciliana, SciMeasure Analyt Syst, Univ Catania DE ASIC; CCD readout; cryogenic; radiation tolerant; low power AB The CRIC (CCD Readout IC) ASIC has been designed to meet the power, space and radiation requirements of the SNAP satellite. It incorporates four channels consisting of a pre-amplifier, double correlated sampler and pipeline AID converter with integrated voltage reference. The CRIC chip has been specifically designed to operate both at room temperature and at typical focal plane temperatures down to 130 K This minimizes wiring complexity while maintaining signal integrity on complex focal planes. CRIC is half of a two ASIC CCD readout system. The other ASIC in development is a bias and clock voltage generator. Also in development are 16 and 32 channel versions of CRIC for use with hybrid photodiode and near infrared pixel arrays. C1 [Karcher, Armin; Bebek, Christopher J.; Fabricius, Maximilian; Krieger, Brad; von der Lippe, Hendrik; Redelstab, Markus; Walder, Jean Pierre] EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Karcher, A (reprint author), EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. EM akarcher@lbl.gov NR 3 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0067-0057 BN 1-4020-4329-5 J9 ASTROPHYS SPACE SC L PY 2006 VL 336 BP 691 EP + DI 10.1007/1-4020-4330-9_85 PG 2 WC Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BEK77 UT WOS:000237613100085 ER PT J AU Bhattacharyya, D Viswanathan, GB Vogel, SC Williams, DJ Venkatesh, V Fraser, HL AF Bhattacharyya, D Viswanathan, GB Vogel, SC Williams, DJ Venkatesh, V Fraser, HL TI A study of the mechanism of alpha to beta phase transformation by tracking texture evolution with temperature in Ti-6Al-4V using neutron diffraction SO SCRIPTA MATERIALIA LA English DT Article DE Ti-6Al-4V; neutron diffraction; texture; phase transformations ID ZIRCONIUM; HCP; BCC AB This paper reports a pioneering investigation of the orientation change of the a phase after recrystallization and the mode of transformation from the alpha to the beta phase on heating above the beta transus in the alpha/beta alloy Ti-6Al-4V by in situ texture measurements done at room temperature, 800 degrees C, 1020 degrees C and again at room temperature using the HIPPO neutron time-of-flight diffractometer at the Los Alamos Neutron Science Center. (c) 2005 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. C1 Ohio State Univ, Dept Mat Sci & Engn, Columbus, OH 43210 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. TIMET R&D, Henderson, NV 89015 USA. RP Bhattacharyya, D (reprint author), Ohio State Univ, Dept Mat Sci & Engn, 477 Watts Hall,2041 Coll Rd, Columbus, OH 43210 USA. EM bhattacharyya.4@osu.edu RI Lujan Center, LANL/G-4896-2012 NR 16 TC 20 Z9 22 U1 1 U2 15 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JAN PY 2006 VL 54 IS 2 BP 231 EP 236 DI 10.1016/j.scriptamat.2005.09.026 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 983IX UT WOS:000233226000020 ER PT J AU Olivas, ER Swadener, JG Shen, YL AF Olivas, ER Swadener, JG Shen, YL TI Nanoindentation measurement of surface residual stresses in particle-reinforced metal matrix composites SO SCRIPTA MATERIALIA LA English DT Article DE nanoindentation; metal matrix composites; residual stresses; finite element analysis ID NEUTRON-DIFFRACTION MEASUREMENTS; X-RAY-DIFFRACTION; THERMAL-EXPANSION; SPHERICAL INDENTATION; ENERGY; STRAINS; LOAD AB The surface residual stresses in SiC particle-rein forced Al matrix composites are measured using a recently developed nanoindentation technique. The tensile biaxial residual stress in At is found to increase with the particle concentration. The stress magnitudes are in reasonable agreement with those from numerical modeling. (c) 2005 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. C1 Univ New Mexico, Dept Mech Engn, Albuquerque, NM 87131 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Shen, YL (reprint author), Univ New Mexico, Dept Mech Engn, Albuquerque, NM 87131 USA. EM shenyl@me.unm.edu RI Shen, Yu-Lin/C-1942-2008; OI Swadener, John G/0000-0001-5493-3461 NR 30 TC 27 Z9 28 U1 3 U2 21 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JAN PY 2006 VL 54 IS 2 BP 263 EP 268 DI 10.1016/j.scriptamat.2005.09.021 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 983IX UT WOS:000233226000026 ER PT S AU Henson, KM Goulias, KG AF Henson, Kriste M. Goulias, Konstadinos G. GP TRB TI Preliminary assessment of activity analysis and modeling for homeland security applications SO SECURITY 2006 SE TRANSPORTATION RESEARCH RECORD LA English DT Article; Proceedings Paper CT 85th Annual Meeting of the Transportation-Research-Board CY JAN 22-26, 2006 CL Washington, DC SP Transportat Res Board ID ACTIVITY-TRAVEL PATTERNS; BEHAVIOR; GENERATION; QUALITY; SYSTEM AB A review of 46 activity-based models is conducted and details features that are required for homeland security applications. Two examples of homeland security studies are included to highlight these needs. This review demonstrates that only a few models have the desired characteristics of fine spatial and temporal resolutions. Because the criticality of locations varies because of time or day of the week or both, depending on the presence of individuals and the fact that potential targets are specific locations within a city, data needs for modeling these types of scenarios exceed typical planning and forecasting modeling as well as research modeling. A discussion of a homeland security-related modeling application conducted by Los Alamos National Laboratory using TRANSIMS for the U.S. Department of Homeland Security is included to demonstrate the level of detail that is achieved by using nationally available data sources. In addition, the literature contains many data and information gaps, including virtually nonexistent models of security; identifying and inventorying residential locations; including more time constraints in models; modeling short-term changes in land use; carefully identifying and filling in missing subpopulations in surveys; accounting for fleets, services, and goods in models; better modeling of inter- and intrahousehold interactions, including weekly and seasonal variations in travel behavior; and developing a new paradigm for activity scheduling in panic and emergency situations. C1 Los Alamos Natl Lab, Decis Applicat Div, Los Alamos, NM 87545 USA. Univ Calif Santa Barbara, Dept Geog, Santa Barbara, CA 93106 USA. RP Henson, KM (reprint author), Los Alamos Natl Lab, Decis Applicat Div, POB 1663,MS F604, Los Alamos, NM 87545 USA. NR 63 TC 5 Z9 5 U1 1 U2 2 PU TRANSPORTATION RESEARCH BOARD NATL RESEARCH COUNCIL PI WASHINGTON PA 500 FIFTH ST, NW, WASHINGTON, DC 20001 USA SN 0361-1981 BN 0-309-09424-0 J9 TRANSPORT RES REC PY 2006 IS 1942 BP 23 EP 30 PG 8 WC Engineering, Civil; Transportation; Transportation Science & Technology SC Engineering; Transportation GA BFJ06 UT WOS:000242169900004 ER PT B AU Lopez, B AF Lopez, Brian BE Auerswald, PE Branscomb, LM LaPorte, TM MichelKerjan, EO TI CRITICAL INFRASTRUCTURE PROTECTION IN THE UNITED STATES SINCE 1993 SO SEEDS OF DISASTER, ROOTS OF RESPONSE: HOW PRIVATE ACTION CAN REDUCE PUBLIC VULNERABILITY LA English DT Article; Book Chapter C1 Lawrence Livermore Natl Lab, VRAP, Livermore, CA 94550 USA. RP Lopez, B (reprint author), Lawrence Livermore Natl Lab, VRAP, Livermore, CA 94550 USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI CAMBRIDGE PA THE PITT BUILDING, TRUMPINGTON ST, CAMBRIDGE CB2 1RP, CAMBS, ENGLAND BN 978-0-521-68572-6 PY 2006 BP 37 EP 50 DI 10.1017/CBO9780511509735.006 D2 10.2277/ 0521685729 PG 14 WC Management; Public Administration SC Business & Economics; Public Administration GA BYD26 UT WOS:000298092400006 ER PT B AU Lopez, B AF Lopez, Brian BE Auerswald, PE Branscomb, LM LaPorte, TM MichelKerjan, EO TI EVOLUTION OF VULNERABILITY ASSESSMENT METHODS SO SEEDS OF DISASTER, ROOTS OF RESPONSE: HOW PRIVATE ACTION CAN REDUCE PUBLIC VULNERABILITY LA English DT Article; Book Chapter C1 Lawrence Livermore Natl Lab, VRAP, Livermore, CA 94550 USA. RP Lopez, B (reprint author), Lawrence Livermore Natl Lab, VRAP, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI CAMBRIDGE PA THE PITT BUILDING, TRUMPINGTON ST, CAMBRIDGE CB2 1RP, CAMBS, ENGLAND BN 978-0-521-68572-6 PY 2006 BP 51 EP 68 DI 10.1017/CBO9780511509735.007 D2 10.2277/ 0521685729 PG 18 WC Management; Public Administration SC Business & Economics; Public Administration GA BYD26 UT WOS:000298092400007 ER PT S AU Aranson, IS Tsimring, LS AF Aranson, Igor S. Tsimring, Lev S. BE Golovin, AA Nepomnyashchy, AA TI Self-organization of microtubules and motors SO SELF-ASSEMBLY, PATTERN FORMATION AND GROWTH PHENOMENA IN NANO-SYSTEMS SE NATO Science Series II-Mathematics Physics and Chemistry LA English DT Proceedings Paper CT NATO Advanced-Study-Institute on Self-Assembly, Patern Formation and Growth Phenomena in Nano-Systems CY AUG 28-SEP 11, 2004 CL St Etienne de Tinee, FRANCE SP NATO Adv Study Inst DE microtubules; molecular motors; self-organization; master equation AB Here we introduce a model for spatio-temporal self-organization of an ensemble of microtubules interacting via molecular motors. Starting from a generic stochastic model of inelastic polar rods with an anisotropic interaction kernel we derive a set of equations for the local rods concentration and orientation. At large enough mean density of rods and concentration of motors, the model describes orientational instability. We demonstrate that the orientational instability leads to the formation of vortices and (for large density and/or kernel anisotropy) asters seen in recent experiments. The corresponding phase diagram of vortex-asters transitions is in qualitative agreement with experiment. C1 [Aranson, Igor S.] Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. [Tsimring, Lev S.] Univ Calif San Diego, Inst Nonlinear Sci, La Jolla, CA 92093 USA. RP Aranson, IS (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM aronson@msd.anl.gov; ltsimring@ucsd.edu RI Aranson, Igor/I-4060-2013 FU NIH FX We thank V. Velculescu, L. Zhang and W. Zhou for help with SAGE analysis; J. A.Duine for bongkrekic acid; J. Flook for assistance with flow cytometry; and members of our laboratories for discussion. This work was supported by the Clayton Fund and by grants from the NIH. K.P. is a research associate and B.V. is an investigator of the Howard Hughes Medical Institute. NR 21 TC 0 Z9 0 U1 3 U2 6 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 1568-2609 BN 1-4020-4353-8 J9 NATO SCI SER II-MATH PY 2006 VL 218 BP 283 EP + PG 2 WC Nanoscience & Nanotechnology SC Science & Technology - Other Topics GA BEI67 UT WOS:000237351500009 ER PT S AU Tucker, BJ Diaz, AA Eckenrode, BA AF Tucker, Brian J. Diaz, Aaron A. Eckenrode, Brian A. BE Carapezza, EM TI Prototype instrument for noninvasive ultrasonic inspection and identification of fluids in sealed containers - art. no. 62010F SO Sensors, and Command, Control, Communications, and Intelligence (C31)Technologies for Homeland Security and Homeland Defense V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, and Command, Control, Communications, and Intelligence (C31) Technologies for Homeland Secuity and Homeland Defense V CY APR 17-21, 2006 CL Kissimmee, FL DE ultrasonic; time-of-flight; pulse compression; signal processing; cross correlation; velocity; attenuation AB Government agencies and homeland security related organizations have identified the need to develop and establish a wide range of unprecedented capabilities for providing scientific and technical forensic services to investigations involving hazardous chemical, biological, and radiological materials, including extremely dangerous chemical and biological warfare agents. Pacific Northwest National Laboratory (PNNL) has developed a prototype portable, hand-held, hazardous materials acoustic inspection prototype that provides noninvasive container interrogation and material identification capabilities using nondestructive ultrasonic velocity and attenuation measurements. Due to the wide variety of fluids as well as container sizes and materials encountered in various law enforcement inspection activities, the need for high measurement sensitivity and advanced ultrasonic measurement techniques were identified. The prototype was developed using a versatile electronics platform, advanced ultrasonic wave propagation methods, and advanced signal processing techniques. This paper primarily focuses on the ultrasonic measurement methods and signal processing techniques incorporated into the prototype. High bandwidth ultrasonic transducers combined with an advanced pulse compression technique allowed researchers to 1) obtain high signal-to-noise ratios and 2) obtain accurate and consistent time-of-flight (TOF) measurements through a variety of highly attenuative containers and fluid media. Results of work conducted in the laboratory have demonstrated that the prototype experimental measurement technique also provided information regarding container properties, which will be utilized in future container-independent measurements of hidden liquids. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Tucker, BJ (reprint author), Pacific NW Natl Lab, POB 999,MS K5-26, Richland, WA 99352 USA. NR 10 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 0-8194-6257-8 J9 P SOC PHOTO-OPT INS PY 2006 VL 6201 BP F2010 EP F2010 AR 62010F DI 10.1117/12.668499 PG 12 WC Engineering, Multidisciplinary SC Engineering GA BER22 UT WOS:000239007800012 ER PT S AU McKakin, DL Sheen, DM Griffin, JW Lechelt, WM AF McKakin, Douglas L. Sheen, David M. Griffin, Jeffery W. Lechelt, Wayne M. BE Carapezza, EM TI Extremely high-frequency holographic radar imaging of personnel and mail - art. no. 62011W SO Sensors, and Command, Control, Communications, and Intelligence (C31)Technologies for Homeland Security and Homeland Defense V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors, and Command, Control, Communications, and Intelligence (C31) Technologies for Homeland Secuity and Homeland Defense V CY APR 17-21, 2006 CL Kissimmee, FL DE millimeter waves; mail screening; personnel surveillance; holography; radar imaging AB The awareness of terrorists covertly transporting chemical warfare (CW) and biological warfare (BW) agents into government, military, and civilian facilities to harm the occupants has increased dramatically since the attacks of 9/11. Government and civilian security personnel have a need for innovative surveillance technology that can rapidly detect these lethal agents, even when they are hidden away in sealed containers and concealed either under clothing or in hand-carried items such as mailed packages or handbags. Sensor technology that detects BW and CW agents in mail or sealed containers carried under the clothing are under development. One promising sensor technology presently under development to detect these threats is active millimeter-wave holographic radar imaging, which can readily image concealed items behind paper, cardboard, and clothing. Feasibility imaging studies at frequencies greater than 40 GHz have been conducted to determine whether simulated biological or chemical agents concealed in mail packages or under clothing could be detected using this extremely high-frequency imaging technique. The results of this imaging study will be presented in this paper. C1 Pacific NW Natl Lab, Richland, WA 99354 USA. RP McKakin, DL (reprint author), Pacific NW Natl Lab, 902 Battelle Blvd, Richland, WA 99354 USA. NR 10 TC 2 Z9 2 U1 0 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 0-8194-6257-8 J9 P SOC PHOTO-OPT INS PY 2006 VL 6201 BP W2011 EP W2011 AR 62011W DI 10.1117/12.668509 PG 12 WC Engineering, Multidisciplinary SC Engineering GA BER22 UT WOS:000239007800058 ER PT S AU Fabricius, MH Bebek, CJ Groom, DE Karcher, A Roe, NA AF Fabricius, MH Bebek, CJ Groom, DE Karcher, A Roe, NA BE Blouke, MM TI Quantum efficiency characterization of back-illuminated CCDs Part 2: Reflectivity measurements SO SENSORS, CAMERAS, AND SYSTEMS FOR SCIENTIFIC/INDUSTRIAL APPLICATIONS VII SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Sensors, Cameras and Systems for Scientific/Industrial Applications VII CY JAN 17-19, 2006 CL San Jose, CA SP SPIE, Soc Imaging Sci & Technol DE CCD; quantum efficiency; reflectometer; reflectivity; calibration AB The usual QE measurement heavily relies on a calibrated photodiode (PD) and the knowledge of the CCD's gain. Either can introduce significant systematic errors. But 1 - R >= QE, where R is the reflectivity. Over a significant wavelength range, 1 - R = QE. An unconventional reflectometer has been developed to make this measurement. R is measured in two steps, using light from the lateral monochromator port via an optical fiber. The beam intensity is measured directly with a PD, then both the PD and CCD are moved so that the optical path length is unchanged and the light reflects once from the CCD: the PD current ratio is R. Unlike the traditional VW scheme this approach makes only one reflection from the CCD surface. Since the reflectivity of the LBNL CCDs might be as low as 2% this increases the signal to noise ratio dramatically. The goal is a 1% accuracy. We obtain good agreement between 1 - R and the direct QE results. C1 Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RP Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM mhfabricius@lbl.gov RI Roe, Natalie/A-8798-2012 FU U.S. Department of Energy [DE-AC03-76S000098]; UCO/Lick providing technical information FX This work was supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC03-76S000098, JPL We are grateful for the support from R. Stover at UCO/Lick providing technical information and taking data for us. NR 6 TC 3 Z9 3 U1 0 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-6108-3 J9 PROC SPIE PY 2006 VL 6068 AR 60680G DI 10.1117/12.667314 PG 11 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BEE23 UT WOS:000236911300016 ER PT S AU Groom, DE Bebek, CJ Fabricius, M Karcher, A Kolbe, WF Roe, NA Steckert, J AF Groom, DE Bebek, CJ Fabricius, M Karcher, A Kolbe, WF Roe, NA Steckert, J BE Blouke, MM TI Quantum efficiency characterization of LBNL CCD's Part 1: the quantum efficiency machine SO SENSORS, CAMERAS, AND SYSTEMS FOR SCIENTIFIC/INDUSTRIAL APPLICATIONS VII SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Sensors, Cameras and Systems for Scientific/Industrial Applications VII CY JAN 17-19, 2006 CL San Jose, CA SP SPIE, Soc Imaging Sci & Technol DE CCD's; quantum efficiency; detectors; astronomy; instrumentation ID ELECTRON-HOLE PAIR; SILICON; SEMICONDUCTORS; IONIZATION; ENERGY; DEPENDENCE; DETECTORS AB Instrumentation was developed in 2004 and 2005 to measure the quantum efficiency of the Lawrence Berkeley National Lab (LBNL) total-depletion CCD's, intended for astronomy and space applications. This paper describes the basic instrument. Althou gh it is conventional even to the parts list, there are important innovations. A xenon arc light source was chosen for its high blue/UV and low red/IR output as compared with a tungsten light. Intensity stabilization has been difficult, but since only flux ratios matter this is not critical. Between the light source and an Oriel MS257 monochromator are a shutter and two filter wheels. High-bandpass and low-bandpass filter pairs isolate the 150-nm wide bands appropriate to the wavelength, thus minimizing scattered light and providing order blocking. Light from the auxiliary port enters a 20-inch optical sphere, and the 4-inch output port is at right angles to the input port. An 80 cm drift space produces near-uniform illumination on the CCD. Next to the cold CCD inside the horizontal dewar is a calibrated reference photodiode which is regulated to the PD calibration temperature, 25 degrees C. The ratio of the CCD and in-dewar reference PD signals provides the QE measurement. Additional cross-calibration to a PD on the integrating sphere permits lower-intensity exposures. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. EM DEGroom@lbl.gov RI Roe, Natalie/A-8798-2012 FU U.S. Department of Energy [DE-ACO2-05CH11231] FX This work was supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-ACO2-05CH11231. We have profited greatly in the design and construction of The Quantum Machine from papers and discussions with P. Amico,5 D. Guzman,19 M. Lesser,20 S. Miyazaki,21 R. Stover, the Indiana/Michigan group, and others who have built similar instruments. NR 22 TC 3 Z9 3 U1 0 U2 7 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-6108-3 J9 PROC SPIE PY 2006 VL 6068 AR 60680F DI 10.1117/12.667313 PG 11 WC Instruments & Instrumentation; Optics SC Instruments & Instrumentation; Optics GA BEE23 UT WOS:000236911300015 ER PT S AU Goedeke, SM Hollerman, WA Bergeron, NP Allison, SW Moore, RJ AF Goedeke, S. M. Hollerman, W. A. Bergeron, N. P. Allison, S. W. Moore, R. J. BE Korman, V TI Developing a phosphor-based health monitoring sensor suite for future spacecraft - art. no. 62220B SO Sensors for Propulsion Measurement Applications SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors for Propulsion Measurement Applications CY APR 20-21, 2006 CL Kissimmee, FL SP SPIE DE phosphor; luminescence; triboluminescence; radioluminescence; half brightness fluence; ZnS ID PROTON-INDUCED FLUORESCENCE; ZNS-MN; YAG-CE; TRIBOLUMINESCENCE AB The desire to explore the Moon and Mars by 2030 makes cost effective and low mass health monitoring sensors essential for spacecraft development. Parameters such as impact, temperature, and radiation fluence need to be measured in order to determine the health of a human occupied vehicle. A phosphor-based sensor offers one good approach to develop a robust health monitoring system. The authors have spent the last few years evaluating physical characteristics of zinc sulfide (ZnS) phosphors. These materials emit triboluminescence (TL) which is fluorescence produced as a result of an impact. Currently, two ZnS materials have been tested for impact response for velocities from 1 m/s to 6 km/s. These materials have also been calibrated for use as temperature sensors from room temperature to 350 C. Finally, any sensor that is intended to function in space must be characterized for response to ionizing radiation. Research to date has included irradiating ZnS with 3 MeV protons and 20 keV electrons, which are likely components of the space radiation environment. Results have shown that that the fluorescence emission intensity decreases with radiation fluence. However, radiation induced damage can be annealed at small fluence levels. This annealing not only increased light intensity of the exposed sample from excitation but also TL excitation as well. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Goedeke, SM (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. OI Allison, Stephen/0000-0002-5887-5403 NR 31 TC 0 Z9 0 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 0-8194-6278-0 J9 P SOC PHOTO-OPT INS PY 2006 VL 6222 BP B2220 EP B2220 AR 62220B DI 10.1117/12.659727 PG 12 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA BES60 UT WOS:000239302800010 ER PT J AU Herrmann, SD Li, SX Simpson, MF Phongikaroon, S AF Herrmann, S. D. Li, S. X. Simpson, M. F. Phongikaroon, S. TI Electrolytic reduction of spent nuclear oxide fuel as part of an integral process to separate and recover actinides from fission products SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 14th Symposium on Separation Science and Technology for Energy Applications CY OCT 23-27, 2005 CL Gatlinburg, TN SP Oak Ridge Natl Lab, Washington State Univ, US DOE, Amer Inst Chem Engineers, Separat Div, Amer Chem So, Ind & Engn Chem Div, Separat Sci & Technol Subdiv, Cytec Canada Inc DE electrolytic reduction; oxide reduction; pyrochemical processing; electrometallurgical treatment; spent oxide fuel treatment; molten LiCl/Li2O ID URANIUM AB Bench-scale tests were performed to study an electrolytic reduction process that converts metal oxides in spent nuclear fuel to metal. Crushed spent oxide fuel was loaded into a permeable stainless steel basket and submerged in a molten salt electrolyte of LiCl-1 wt% Li2O at 650 degrees C. An electrical current was passed through the fuel basket and a submerged platinum wire, effecting the reduction of metal oxides in the fuel and the formation of oxygen gas on the platinum wire surface. Salt and fuel samples were analyzed, and the extent of fission product separation and metal oxide reduction was determined. C1 Idaho Natl Lab, Cycle Programs Div, Idaho Falls, ID 83415 USA. RP Herrmann, SD (reprint author), Idaho Natl Lab, Cycle Programs Div, POB 1625, Idaho Falls, ID 83415 USA. EM steven.herrmann@inl.gov NR 5 TC 38 Z9 38 U1 0 U2 9 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 10 BP 1965 EP 1983 DI 10.1080/01496390600745602 PG 19 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 065HI UT WOS:000239150300003 ER PT J AU Solbrig, CW Vaden, D AF Solbrig, C. W. Vaden, DeeEarl TI Electrorefiner liquid cadmium cathode crucible thermal shock SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 14th Symposium on Separation Science and Technology for Energy Applications CY OCT 23-27, 2005 CL Gatlinburg, TN SP Oak Ridge Natl Lab, Washington State Univ, US DOE, Amer Inst Chem Engineers, Separat Div, Amer Chem So, Ind & Engn Chem Div, Separat Sci & Technol Subdiv, Cytec Canada Inc DE Pyrochemical processing; electrorefiner; thermal stress; vessel failure AB A liquid cadmium cathode is used in an electrorefiner to remove plutonium and minor actinides from spent nuclear fuel by pyroprocessing. Liquid cadmium in a beryllia crucible, originally at 35 degrees C, is lowered into 500 degrees C salt electrolyte to begin reprocessing. Crucible cracking from thermal stress would release cadmium into the liquid salt causing electrorefiner failure. This study's purpose was to predict if the ceramic crucible would fail. A handbook method showed it would. An analytical model eliminating two large conservatisms predicted no failure. A beryllia crucible preheated to 321 degrees C was successfully immersed in electrorefiner salt without failure. The conclusion is that handbook methods can be severely conservative in predicting thermal stress failures for immersion in low thermal conductivity fluids. C1 Idaho Natl Lab, Fuel Cycle Programs Div, Idaho Falls, ID 83415 USA. RP Solbrig, CW (reprint author), Idaho Natl Lab, Fuel Cycle Programs Div, POB 1625, Idaho Falls, ID 83415 USA. EM charles.solbrig@inl.gov NR 8 TC 1 Z9 1 U1 1 U2 3 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 10 BP 1985 EP 2001 DI 10.1080/01496390600745750 PG 17 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 065HI UT WOS:000239150300004 ER PT J AU Vaden, D AF Vaden, DeeEarl TI Fuel conditioning facility electrorefiner process model SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 14th Symposium on Separation Science and Technology for Energy Applications CY OCT 23-27, 2005 CL Gatlinburg, TN SP Oak Ridge Natl Lab, Washington State Univ, US DOE, Amer Inst Chem Engineers, Separat Div, Amer Chem So, Ind & Engn Chem Div, Separat Sci & Technol Subdiv, Cytec Canada Inc DE pyrochemical processing; electrorefiner; chemical equilibrium; stoichiometric AB The Fuel Conditioning Facility at the Idaho National Laboratory processes spent nuclear fuel from the Experimental Breeder Reactor II using electro-metallurgical treatment. To process fuel without waiting for periodic sample analyses to assess process conditions, an electrorefiner process model predicts the composition of the electrorefiner inventory and effluent streams. For the chemical equilibrium portion of the model, the two common methods for solving chemical equilibrium problems, stoichiometric and non-stoichiometric , were investigated. In conclusion, the stoichiometric method produced equilibrium compositions close to the measured results whereas the non-stoichiometric method did not. C1 Idaho Natl Lab, Fuel Cycle Programs Div, Idaho Falls, ID 83415 USA. RP Vaden, D (reprint author), Idaho Natl Lab, Fuel Cycle Programs Div, POB 1625, Idaho Falls, ID 83415 USA. EM dee.vaden@inl.gov NR 9 TC 4 Z9 4 U1 0 U2 1 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 10 BP 2003 EP 2012 DI 10.1080/01496390600745792 PG 10 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 065HI UT WOS:000239150300005 ER PT J AU Rudisill, TS Crowder, ML AF Rudisill, Tracy S. Crowder, Mark L. TI Dissolution of fissile materials containing plutonium and beryllium metals SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 14th Symposium on Separation Science and Technology for Energy Applications CY OCT 23-27, 2005 CL Gatlinburg, TN SP Oak Ridge Natl Lab, Washington State Univ, US DOE, Amer Inst Chem Engineers, Separat Div, Amer Chem So, Ind & Engn Chem Div, Separat Sci & Technol Subdiv, Cytec Canada Inc DE Plutonium; beryllium; metal dissolution AB Scrap materials containing plutonium (Pu) metal were dissolved at the Savannah River Site (SRS) as part of a program to disposition nuclear materials during the deactivation of the FB-Line facility. Some of these items contained both Pu and beryllium (Be) metal as a composite material. The Pu and Be metals were physically separated to minimize the amount of Be associated with the Pu; however, a dissolution flowsheet was required to dissolve small amounts of Be combined with the Pu metal using a dissolving solution containing nitric acid (HNO3) and potassium fluoride (KF). Since the dissolution of Pu metal in HNO3/fluoride (F-) solutions was well understood, the primary focus of the flowsheet development was the dissolution of Be metal. Initially, small-scale experiments were used to measure the dissolution rate of Be metal foils using conditions effective for the dissolution of Pu metal. The experiments demonstrated that the dissolution rate was nearly independent of the HNO3 concentration over the limited range of investigation and only a moderate to weak function of the F- concentration. The effect of temperature was more pronounced, significantly increasing the dissolution rate between 40 and 105 degrees C. The off gas analysis from three Be metal foil dissolutions demonstrated that the production of hydrogen (H-2) was sensitive to the HNO3 concentration, decreasing by a factor of approximately two when the concentration was increased from 4 to 8 M. In subsequent experiments, complete dissolution of Be samples from a Pu/Be composite material was achieved in a 4 M HNO3 solution containing 0.1-0.2 M KF. Gas samples collected during each experiment showed that the maximum H-2 generation rate occurred at temperatures below 70-80 degrees C. A Pu metal dissolution experiment was performed using a 4M HNO3/0.1 M KF solution at 80 degrees C to demonstrate flowsheet conditions developed for the dissolution of Be metal. As the reaction progressed, the rate of dissolution slowed. The decrease in rate was attributed to the complexation of F- by the dissolved Pu. The F- became unavailable to catalyze the dissolution of plutonium oxide (PuO2) formed on the surface of the metal which inhibited the dissolution rate. To compensate for the complexation of F- , an increase in the concentration to 0.15-0.2 M was recommended. Dissolution of the PuO2 was addressed by recommending an 8-10 h dissolution time with an increase in the dissolving temperature (to near boiling) during the final 4-6 h to facilitate the digestion of the solids. Dilution of the H-2 concentration below 25% of the lower flammability limit by purging the dissolver with air was also necessary to eliminate the flammability concern. C1 Westinghouse Savannah River Co, Savannah River Natl Lab, Aiken, SC 29808 USA. RP Rudisill, TS (reprint author), Westinghouse Savannah River Co, Savannah River Natl Lab, Aiken, SC 29808 USA. EM tracy.rudisill@srnl.doe.gov NR 10 TC 3 Z9 3 U1 0 U2 2 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 10 BP 2013 EP 2029 DI 10.1080/01496390600742930 PG 17 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 065HI UT WOS:000239150300006 ER PT J AU Stroud, MA Salazar, RR Abney, KD Bluhm, EA Danis, JA AF Stroud, Mary Ann Salazar, Richard R. Abney, Kent D. Bluhm, Elizabeth A. Danis, Janet A. TI Purification of plutonium chloride solutions via precipitation and washing SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 14th Symposium on Separation Science and Technology for Energy Applications CY OCT 23-27, 2005 CL Gatlinburg, TN SP Oak Ridge Natl Lab, Washington State Univ, US DOE, Amer Inst Chem Engineers, Separat Div, Amer Chem So, Ind & Engn Chem Div, Separat Sci & Technol Subdiv, Cytec Canada Inc DE Plutonium; chloride; aqueous; purification AB Pyrochemical operations at Los Alamos Plutonium Facility use high temperature melts of calcium, sodium, and potassium salts in the plutonium metal purification process. Aqueous chloride operations recover the remaining plutonium from the residue salts, generating copious quantities of corrosive aqueous waste while occupying a large area of the facility. To minimize these problems, an alternative flow sheet was tested in which dissolved salts were precipitated and washed to remove interstitial chloride before further processing in aqueous nitrate operations. Results of the tests will be discussed from the perspective of chloride removal, plutonium recovery, filterability, and waste minimization. C1 Los Alamos Natl Lab, NMT 2, Los Alamos, NM 87545 USA. RP Stroud, MA (reprint author), Los Alamos Natl Lab, NMT 2, POB 1663,Mail Stop E511, Los Alamos, NM 87545 USA. EM mstroud@lanl.gov NR 2 TC 0 Z9 0 U1 0 U2 3 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 10 BP 2031 EP 2046 DI 10.1080/01496390600742997 PG 16 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 065HI UT WOS:000239150300007 ER PT J AU Dietz, ML AF Dietz, Mark L. TI Ionic liquids as extraction solvents: Where do we stand? SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 14th Symposium on Separation Science and Technology for Energy Applications CY OCT 23-27, 2005 CL Gatlinburg, TN SP Oak Ridge Natl Lab, Washington State Univ, US DOE, Amer Inst Chem Engineers, Separat Div, Amer Chem Soc, Ind & Engn Chem Div, Separat Sci & Technol Subdiv, Cytec Canada Inc DE ionic liquids; extraction solvents; metalion exchange ID METAL-IONS; LIQUID/LIQUID EXTRACTION; CROWN-ETHERS; FACILITATED TRANSFER; STRONTIUM NITRATE; ORGANIC-PHASE; AMINO-ACIDS; MEDIA; IMIDAZOLIUM; MECHANISM AB The unique physicochemical properties of ionic liquids (ILs) and the relative ease with which these properties can be fine-tuned by altering the cationic or anionic moieties comprising the IL have led to intense interest in their use as alternatives to conventional organic solvents in a wide range of synthetic, catalytic, and electrochemical applications. Recent work by a number of investigators has been directed at the application of ionic liquids in various separation processes, among them the liquid-liquid extraction of metal ions. Although certain IL-extractant combinations have been shown to yield metal ion extraction efficiencies far greater than those obtained with molecular organic solvents, other work suggests that the utility of ILs may be limited by solubilization losses and difficulty in recovering extracted metal ions. In this report, recent efforts to overcome these limitations are described, and progress both in achieving an improved understanding of the fundamental aspects of metal ion transfer into ILs and in devising viable IL-based systems for metal ion separation is detailed. In addition, areas upon which future research efforts might profitably be focused are identified. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Dietz, ML (reprint author), Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. EM mdietz@anl.gov NR 51 TC 205 Z9 208 U1 2 U2 38 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEP SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 10 BP 2047 EP 2063 DI 10.1080/01496390600743144 PG 17 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 065HI UT WOS:000239150300008 ER PT J AU Plaue, J AF Plaue, J. TI Actinide third phase formation in 1.1 m TBP/Nitric Acid/Alkane diluent systems SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 14th Symposium on Separation Science and Technology for Energy Applications CY OCT 23-27, 2005 CL Gatlinburg, TN SP Oak Ridge Natl Lab, Washington State Univ, US DOE, Amer Inst Chem Engineers, Separat Div, Amer Chem So, Ind & Engn Chem Div, Separat Sci & Technol Subdiv, Cytec Canada Inc DE third phase; plutonium; neptunium; speciation; tri-n-butyl phosphate ID PLUTONIUM 3RD-PHASE-FORMATION; BUTYL PHOSPHATE; FT-IR; EXTRACTION; TBP; SPHERES; MODEL; SANS AB Additional information on the organic phase speciation of Np and Pu was obtained in order to further understand the impact on third phase formation. In the Np(VI) extraction system, indications of the presence of a species associated with the absorbance at 1210 nm appears to be consistent with an increased tendency for third phase formation. Attempts to couple this absorption peak to a higher order nitrate species were inconclusive, and further study is required. For Pu(VI), continued evidence has emerged suggesting a role of higher order nitrate species in third phase formation. C1 Def Nucl Facilities Safety Board, Washington, DC 20004 USA. Argonne Natl Lab, Div Chem Engn, Argonne, IL USA. Univ Nevada, Dept Chem, Las Vegas, NV 89154 USA. RP Plaue, J (reprint author), Def Nucl Facilities Safety Board, 625 Indiana Ave, Washington, DC 20004 USA. EM jplaue@alum.mit.edu NR 21 TC 10 Z9 11 U1 2 U2 8 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 10 BP 2065 EP 2074 DI 10.1080/01496390600745362 PG 10 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 065HI UT WOS:000239150300009 ER PT J AU Chiarizia, R Stepinski, DC Thiyagarajan, P AF Chiarizia, R. Stepinski, D. C. Thiyagarajan, P. TI SANS study of third phase formation in the extraction of HCl by TBP isomers in n-octane SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 14th Symposium on Separation Science and Technology for Energy Applications CY OCT 23-27, 2005 CL Gatlinburg, TN SP Oak Ridge Natl Lab, Washington State Univ, US DOE, Amer Inst Chem Engineers, Separat Div, Amer Chem So, Ind & Engn Chem Div, Separat Sci & Technol Subdiv, Cytec Canada Inc DE TBP; HCl extraction; third phase formation ID NORMAL-BUTYL PHOSPHATE; TRIALKYL PHOSPHATES; 3RD-PHASE FORMATION; SURFACE-ADHESION; DODECANE SYSTEM; HARD-SPHERES; BAXTER MODEL; SCATTERING; SEPARATION; DILUENT AB Third phase formation in the extraction of HCl by triisobutyl phosphate (T- iso-BP) and tri-sec-butyl phosphate (T- sec-BP) has been investigated and compared with the tri-n-butyl phosphate (T-n-BP) system. The three TBP isomers exhibit comparable affinities for HCl, but the branched isomers extract much more water than the linear one. For T- sec-BP, the LOC (limiting HCl organic concentration) is characterized by much lower HCl concentrations both in the organic and aqueous phase than for the other isomers. SANS data for T-iso-BP and T- sec-BP organic phases loaded with progressive amounts of HCl have been interpreted using the Baxter model for hard spheres with surface adhesion. The critical values of the stickiness parameter, tau(-s) , and the interaction potential energy, U(r), are slightly different and characteristic for each of the extractants. Their values are consistent with the expectation derived from the micellar interaction model. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, IPNS Div, Argonne, IL USA. RP Chiarizia, R (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM chiarizia@anl.gov NR 32 TC 14 Z9 14 U1 1 U2 5 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 10 BP 2075 EP 2095 DI 10.1080/01496390600742716 PG 21 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 065HI UT WOS:000239150300010 ER PT J AU Romanovskiy, VN Babain, VA Alyapyshev, MY Smirnov, IV Herbst, RS Law, JD Todd, TA AF Romanovskiy, V. N. Babain, V. A. Alyapyshev, M. Yu. Smirnov, I. V. Herbst, R. S. Law, J. D. Todd, T. A. TI Radionuclide extraction by 2,6-pyridinedicarboxylamide derivatives and chlorinated cobalt dicarbollide SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 14th Symposium on Separation Science and Technology for Energy Applications CY OCT 23-27, 2005 CL Gatlinburg, TN SP Oak Ridge Natl Lab, Washington State Univ, US DOE, Amer Inst Chem Engineers, Separat Div, Amer Chem So, Ind & Engn Chem Div, Separat Sci & Technol Subdiv, Cytec Canada Inc DE cobalt dicarbollide; diamides of dipicolinamide; extraction; cesium; strontium; actinides; lanthanides ID SEPARATION; AMERICIUM; STRONTIUM; EUROPIUM; SOLVENT; CESIUM; WASTE AB The extraction properties of diamide derivatives of dipicolinamide ( 2,6-pyridinedicarboxylamide or DPA, ( R'R"NCO)(2)C5NH3) in mixtures containing chlorinated cobalt dicarbollide in the acid form ( HCCD), with and without a substituted polyethylene glycol ( PEG), have been investigated. Distribution ratios of Cs, Sr, U, Eu and Am have been measured for various concentrations of diamide, PEG, aqueous phase nitric acid, with various HCCD: diamide ratios, and using different organic diluents. In the absence of HCCD, the diamides show little affinity for the extraction of Am or Eu from nitric acid solutions ( distributions typically,1). Addition of HCCD with the diamide extractants indicates a pronounced synergistic effect with regard to actinide and lanthanide extraction; the observed Am and Eu distribution ratios typically increase by several orders of magnitude. Cesium is also appreciably extracted by the HCCD in the presence of the various diamides. Addition of PEG ( to simultaneously extract Sr) with HCCD and diamide has minimal impacts on the Eu and Am distribution ratios. The initial data indicate that alkyl substituted DPA derivatives weakly affect the extraction properties with regard to actinides and lanthanides, while aryl substituents decrease extraction ability of the mixture. The results of this preliminary work indicate that numerous HCCD-PEG-DPA systems are promising and effective for the simultaneous extraction Cs, Sr, Am, and Eu from acidic solutions. C1 Idaho Natl Lab, Idaho Falls, ID 83415 USA. RPA VG Khlopin Radium Inst, St Petersburg, Russia. RP Herbst, RS (reprint author), Idaho Natl Lab, POB 1625, Idaho Falls, ID 83415 USA. EM r.herbst@inl.gov RI Todd, Terry /O-4930-2016; OI Todd, Terry /0000-0003-1324-6950; Law, Jack/0000-0001-7085-7542 NR 15 TC 34 Z9 34 U1 0 U2 5 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 10 BP 2111 EP 2127 DI 10.1080/01496390600744365 PG 17 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 065HI UT WOS:000239150300012 ER PT J AU Matloka, K Gelis, A Regalbuto, M Vandegrift, G Scott, MJ AF Matloka, Kornelia Gelis, Artem Regalbuto, Monica Vandegrift, George Scott, Michael J. TI C-3-symmetric tripodal thio/diglycolamide-based ligands for trivalent f-element separations SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 14th Symposium on Separation Science and Technology for Energy Applications CY OCT 23-27, 2005 CL Gatlinburg, TN SP Oak Ridge Natl Lab, Washington State Univ, US DOE, Amer Inst Chem Engineers, Separat Div, Amer Chem So, Ind & Engn Chem Div, Separat Sci & Technol Subdiv, Cytec Canada Inc DE extraction of lanthanides and actinides; nuclear waste separations; diglycolamide; thiodiglycolamide; C-3-symmetric ligand ID LIQUID-LIQUID-EXTRACTION; NITRIC-ACID SOLUTION; SOFT DONOR LIGANDS; SOLVENT-EXTRACTION; TRIPHENOXYMETHANE PLATFORM; LANTHANIDE IONS; MINOR ACTINIDES; DIAMEX PROCESS; CMPO-FUNCTIONS; AMIDO PODANDS AB Three new C-3 -symmetric ligands bearing diglycolamide and thiodiglycolamide units on a triphenoxymethane platform have been synthesized and evaluated as trivalent f-element extractants from nitric acid media. Liquid-liquid extraction studies of eleven different lanthanides from 1 M nitric acid into dichloromethane revealed a strong influence of the amidic substituents on the extraction efficiency. A comparison of the 1 H NMR spectrum of the Lu(III) complex formed with the tris-DGA ligand and the organic solution after the extraction experiment confirms that all three arms bind the metal during the extraction experiment and form a C 3 -symmetric complex. The newly synthesized lipophilic di-n-butyl tris-diglycolamide was found to be a significantly weaker extractant in comparison to the di-isopropyl analogs. The distance separating the metal binding groups from the triphenoxymethane platform had little influence on the selectivity or binding efficiency of the ligands. Experiments with the tris-thiodiglycolamide derivative highlighted the importance of the etheric oxygens for metal binding. C1 Univ Florida, Gainesville, FL 32611 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Scott, MJ (reprint author), Univ Florida, POB 117200, Gainesville, FL 32611 USA. EM mjscott@chem.ufl.edu RI Scott, Michael/B-7859-2013 NR 60 TC 17 Z9 17 U1 2 U2 8 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 10 BP 2129 EP 2146 DI 10.1080/01496390600745727 PG 18 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 065HI UT WOS:000239150300013 ER PT J AU Tripp, J Garn, T Boardman, R Law, J AF Tripp, Julia Garn, Troy Boardman, Richard Law, Jack TI Development of steam reforming for the solidification of the cesium and strontium separations product from advanced aqueous reprocessing of spent nuclear fuel SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 14th Symposium on Separation Science and Technology for Energy Applications CY OCT 23-27, 2005 CL Gatlinburg, TN SP Oak Ridge Natl Lab, Washington State Univ, US DOE, Amer Inst Chem Engineers, Separat Div, Amer Chem So, Ind & Engn Chem Div, Separat Sci & Technol Subdiv, Cytec Canada Inc DE solvent extraction; solidification; steam reforming AB Steam reforming is one option currently being investigated for stabilization of the cesium/strontium strip products from spent fuel reprocessing solvent extraction processes because it can potentially destroy the nitrates and organics present in these aqueous, nitrate-bearing solutions, while converting the cesium and strontium into leach resistant aluminosilicate minerals, such as pollucite. To produce pollucite and other mineral analogs of the alkaline metals, the feeds must be mixed with aluminosilicate compounds and thermally sintered or calcined to activate solid-state crystal formation. Scoping tests completed indicated that the cesium/strontium in these organic and acid solutions can be converted into aluminosilicate materials using steam reforming. C1 Idaho Natl Lab, Idaho Falls, ID 83415 USA. RP Tripp, J (reprint author), Idaho Natl Lab, POB 1625, Idaho Falls, ID 83415 USA. EM julia.tripp@inl.gov OI Law, Jack/0000-0001-7085-7542 NR 2 TC 1 Z9 1 U1 1 U2 3 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 10 BP 2147 EP 2162 DI 10.1080/01496390600742914 PG 16 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 065HI UT WOS:000239150300014 ER PT J AU Horwitz, EP McAlister, DR Dietz, ML AF Horwitz, E. Philip McAlister, Daniel R. Dietz, Mark L. TI Extraction chromatography versus solvent extraction: How similar are they? SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 14th Symposium on Separation Science and Technology for Energy Applications CY OCT 23-27, 2005 CL Gatlinburg, TN SP Oak Ridge Natl Lab, Washington State Univ, US DOE, Amer Inst Chem Engineers, Separat Div, Amer Chem So, Ind & Engn Chem Div, Separat Sci & Technol Subdiv, Cytec Canada Inc DE solvent extraction; extraction chromatography; lanthanide separations ID LIQUID-LIQUID CHROMATOGRAPHY; PARTITION CHROMATOGRAPHY; IMPREGNATED RESINS; CHELATING AGENTS; REVERSED PHASES; RARE EARTHS; SEPARATION; ACID; BEHAVIOUR; DITHIZONE AB Over the last decade, extraction chromatography (EXC) has emerged as a versatile and effective method for the separation and preconcentration of a number of metal ions. Frequently, EXC is described as a technique that combines the selectivity of solvent extraction (SX) with the ease of operation of chromatographic methods. Despite this, the extent to which EXC actually provides the selectivity of SX and to which solvent extraction data can be used for the quantitative prediction of the retention of metal ions on an EXC column has remained unclear. To address these questions, the extraction chromatographic and solvent extraction behavior of lanthanides using three different acidic organophosphorus extractants bis-(2-ethylhexyl)phosphoric acid (HDEHP), 2-ethylhexyl 2-ethylhexylphosphonic acid (HEH[EHP]), and bis-(2,4,4 trimethylpentyl)phosphinic acid (H[DTMPeP])) have been compared. Specifically, the rate and extent of uptake of selected lanthanides by the three extractants have been examined. In addition, the relationship between the volume distribution ratios obtained in the chromatographic and liquid-liquid extraction modes have been compared and their utility in predicting the chromatographic parameter, k', the number of free column volumes to peak maximum determined. C1 PG Res Fdn Inc, Darien, IL 60561 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Horwitz, EP (reprint author), PG Res Fdn Inc, 8205 S Cass Ave,Suite 106, Darien, IL 60561 USA. EM phorwitz@pgrf.com NR 22 TC 31 Z9 31 U1 4 U2 25 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 10 BP 2163 EP 2182 DI 10.1080/01496390600742849 PG 20 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 065HI UT WOS:000239150300015 ER PT J AU Dietz, ML Ensor, DD Harmon, B Seekamp, S AF Dietz, Mark L. Ensor, Dale D. Harmon, Ben Seekamp, Stefan TI Separation and preconcentration of cesium from acidic media by extraction chromatography SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 14th Symposium on Separation Science and Technology for Energy Applications CY OCT 23-27, 2005 CL Gatlinburg, TN SP Oak Ridge Natl Lab, Washington State Univ, US DOE, Amer Inst Chem Engineers, Separat Div, Amer Chem Soc, Ind & Engn Chem Div, Separat Sci & Technol Subdiv, Cytec Canada Inc DE cesium; separation; preconcentration; extraction chromatography; calixarene ID 1,3-ALTERNATE CONFORMATION; MACROCYCLE INTERACTION; FISSION PRODUCTS; ALKALI-METALS; CROWN-ETHERS; KINETIC DATA; STRONTIUM; SAMPLES; CS-137; ACTINIDES AB A novel extraction chromatographic resin for the separation and preconcentration of cesium from acidic nitrate media comprising an inert polymeric substrate impregnated with 1,3-calix[4]bis-o-benzo-crown-6 ("BC6B) in a chlorinated diluent is described. Cesiam is shown to be both strongly and selectively retained by the resin at low (< 1m) . Only potassium ion (at concentrations exceeding ca. 0.01 M) exerts a significant adverse impact on cesium retention. Unexpectedly, cesium uptake by the resin does not exhibit the acid dependency anticipated from liquid-liquid extraction data. This is also the case for a resin employing a related macrocyclic extractant, calix[4]arene-bis-(t-octylbenzocrown-6)("BobCalix), prepared and partly characterized in an effort to overcome certain limitations of the BC6B-based material. Despite this, the resin is shown to be well suited to the isolation of radiocesium from acidic solution for subsequent determination or for the removal of cesium intereference in the quantitation of other radionuclides. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Tennessee Technol Univ, Cookeville, TN 38505 USA. RP Dietz, ML (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM mdietz@anl.gov NR 49 TC 13 Z9 13 U1 6 U2 11 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEP SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 10 BP 2183 EP 2204 DI 10.1080/01496390600744480 PG 22 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 065HI UT WOS:000239150300016 ER PT J AU Birdwell, JF McFarlane, J Hunt, RD Luo, HM DePaoli, DW AF Birdwell, Joseph F., Jr. McFarlane, Joanna Hunt, Rodney D. Luo, Huimin DePaoli, David W. TI Separation of ionic liquid dispersions in centrifugal solvent extraction contactors SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 14th Symposium on Separation Science and Technology for Energy Applications CY OCT 23-27, 2005 CL Gatlinburg, TN SP Oak Ridge Natl Lab, Washington State Univ, US DOE, Amer Inst Chem Engineers, Separat Div, Amer Chem So, Ind & Engn Chem Div, Separat Sci & Technol Subdiv, Cytec Canada Inc DE ionic liquid; liquid-liquid extraction; solvent extraction; centrifugal contactor ID CESIUM; SR2+; CS+ AB Separations of dispersions formed by mixing immiscible organic room-temperature ionic liquids (IL)/hydrocarbon/and aqueous systems using a centrifugal solvent-extraction contactor have been successfully demonstrated in proof-of-concept testing. This accomplishment is significant in that physical property factors that are typical of ionic liquid systems (e.g., similar densities of the bulk phases, low interfacial tensions, and high viscosities) are typically unfavorable for dispersion separation, particularly in continuous processes. Efficient separation of dispersions containing ionic liquid solvents is essential for utilization of these compounds in liquid-liquid extraction applications to maximize both solute transfer efficiency and solvent recovery. Efficient solvent recovery is of particular concern in IL applications because of the high cost of most IL solvents. This paper presents the results of initial experiments with three hydrophobic ionic liquids to determine how their physical properties affect phase mixing and phase disengagement in contact with an aqueous solution using a centrifugal contactor. While the results of the reported work are promising, additional work is needed to optimize existing mathematical models of contactor hydraulics to address special considerations involved in IL-based processes and to optimize the equipment itself for IL applications. C1 Oak Ridge Natl Lab, Nucl Sci & Technol Div, Oak Ridge, TN 37831 USA. Univ Wisconsin, Dept Nucl Engn, Madison, WI USA. Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN USA. RP Birdwell, JF (reprint author), Oak Ridge Natl Lab, Nucl Sci & Technol Div, Oak Ridge, TN 37831 USA. EM birdwelljfjr@ornl.gov RI McFarlane, Joanna/C-5998-2016 OI McFarlane, Joanna/0000-0002-4112-5104 NR 22 TC 23 Z9 23 U1 0 U2 11 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 10 BP 2205 EP 2223 DI 10.1080/01496390600745719 PG 19 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 065HI UT WOS:000239150300017 ER PT J AU Rapko, BM Geeting, JGH Sinkov, SI Vienna, JD AF Rapko, B. M. Geeting, J. G. H. Sinkov, S. I. Vienna, J. D. TI Oxidative-alkaline leaching of washed 241-SY-102 and 241-SX-101 tank sludges and its impact on immobilized high-level waste SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 14th Symposium on Separation Science and Technology for Energy Applications CY OCT 23-27, 2005 CL Gatlinburg, TN SP Oak Ridge Natl Lab, Washington State Univ, US DOE, Amer Inst Chem Engineers, Separat Div, Amer Chem So, Ind & Engn Chem Div, Separat Sci & Technol Subdiv, Cytec Canada Inc DE oxidative leaching; chromium; Hanford tank sludge; permanganate AB This report describes work designed to evaluate the effectiveness of alkaline permanganate contacts at selectively removing chromium from the Hanford tank sludges 241-SY-102 and 241-SX-101. The key variables examined in this study, as compared to contact with the standard conditions of stoichiometric permanganate in 3 M hydroxide at elevated temperature, were: a) excess permanganate and hydroxide at elevated temperature, b) sequential elevated temperature 3 M hydroxide leach combined with either a room temperature permanganate contact or an elevated temperature permanganate contact at 0.25 M hydroxide. It was determined that sequential permanganate and caustic leaching can provide as effective removal of Cr as the combined high hydroxide permanganate contact at elevated temperature while minimizing concomitant Pu dissolution. C1 Battelle Pacific NW Div, Richland, WA 99352 USA. RP Rapko, BM (reprint author), Battelle Pacific NW Div, Richland, WA 99352 USA. EM brian.rapko@pnl.gov NR 31 TC 1 Z9 1 U1 0 U2 1 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 10 BP 2245 EP 2265 DI 10.1080/01496390600750917 PG 21 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 065HI UT WOS:000239150300019 ER PT J AU Josephson, GB Geeting, JGH Lessor, DL Barton, WB AF Josephson, G. B. Geeting, J. G. H. Lessor, D. L. Barton, W. B. TI Axial dispersion during hanford saltcake washing SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article; Proceedings Paper CT 14th Symposium on Separation Science and Technology for Energy Applications CY OCT 23-27, 2005 CL Gatlinburg, TN SP Oak Ridge Natl Lab, Washington State Univ, US DOE, Amer Inst Chem Engineers, Separat Div, Amer Chem So, Ind & Engn Chem Div, Separat Sci & Technol Subdiv, Cytec Canada Inc DE axial dispersion; Hanford; salt cake; mass transport; washing AB This paper describes laboratory-scale testing conducted to evaluate Selective Dissolution of cesium from non-radioactive Hanford tank 241-S-112 salt cake simulant containing the primary chemicals found in the actual tank. A modified axial dispersion model with increasing axial dispersion was developed to predict cesium removal. The model recognizes that water dissolves the salt cake during washing, which causes an increase in the axial dispersion during the wash. This model was subsequently compared with on-line cesium measurements from the retrieval of tank 241-S-112. The model had remarkably good agreement with both the lab-scale and full-scale data. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. CH2M Hill Inc, Richland, WA USA. RP Josephson, GB (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. EM gary.josephson@pnl.gov NR 8 TC 1 Z9 1 U1 0 U2 0 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 10 BP 2267 EP 2282 DI 10.1080/01496390600745586 PG 16 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 065HI UT WOS:000239150300020 ER PT J AU Lambert, D Peters, TB Fink, SD AF Lambert, Dan Peters, Thomas B. Fink, Samuel D. TI Copper-catalyzed peroxide oxidation testing for tetraphenylborate decomposition SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article DE organic; oxidation; high-level waste AB A new processing option, copper-catalyzed hydrogen peroxide oxidation of tetraphenylborate under alkaline conditions, was demonstrated in laboratory testing. Laboratory-scale tests were conducted to evaluate the use of copper-catalyzed hydrogen peroxide oxidation to treat simulants of the Savannah River Site tank waste. The oxidation process involves the reaction of hydrogen peroxide with a copper catalyst to form hydroxyl free radicals. With an oxidation potential of 2.8 volts, the hydroxyl free radical is a very powerful oxidant, second only to fluorine, and will react with a wide range of organic molecules. The goal is to oxidize the tetraphenylborate completely to carbon dioxide, with minimal benzene generation. Testing was completed in a lab-scale demonstration apparatus at the Savannah River National Laboratory. Greater than 99.8% tetraphenylborate destruction was achieved in less than three weeks. Offgas benzene analysis by a gas chromatograph demonstrated low benzene generation. Analysis of the resulting slurry demonstrated >82.3% organic carbon destruction. The only carbon compounds detected were formate, oxalate, benzene (vapor), carbonate, p-terphenyl, quaterphenyl, phenol, and phenol 3-dimethylamino. C1 Washington Savannah River Co, Savannah River Natl Lab, Aiken, SC 29808 USA. RP Lambert, D (reprint author), Washington Savannah River Co, Savannah River Natl Lab, Bldg 773-A, Aiken, SC 29808 USA. EM dan.lambert@srnl.doe.gov NR 13 TC 0 Z9 0 U1 1 U2 4 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 11 BP 2299 EP 2312 DI 10.1080/01496390600742617 PG 14 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 069MU UT WOS:000239452500001 ER PT J AU Geeting, JGH Hallen, RT Peterson, RA AF Geeting, J. G. H. Hallen, R. T. Peterson, R. A. TI Ultrafilter conditions for high-level waste sludge processing SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article DE ultrafiltration; high-level waste; concentration polarization; optimization AB Optimal filtration conditions were evaluated for the ultrafiltration process planned for pretreating high-level waste (HLW) sludge in the Hanford Waste Treatment Plant. This sludge must be filtered in the pretreatment process to remove sodium and, consequently, reduce the number of canisters for storage. The evaluation, which was based on Hanford HLW slurry test data, was performed to identify the optimal pressure drop and crossflow velocity for filtration at both high and low solids loading. Results from this analysis indicate that the actual filtration rate achieved is relatively insensitive to these conditions under anticipated operating conditions. The maximum filter flux was obtained by adjusting the system control valve pressure to between 400 kPa and 650 kPa while the filter feed concentration increased from 5 wt% to 20 wt%. However, operating the system with a constant control-valve pressure drop of 500 kPa resulted in a reduction of less than 1% in the average filter flux. Also, allowing the control valve pressure to swing as much as 20% resulted in less than a 5% decrease in filter flux. This analysis indicates that a back pressure setting of 500 kPa100 kPa will give effectively optimal results for the system of interest. C1 Pacific NW Natl Lab, Richland, WA 99354 USA. RP Geeting, JGH (reprint author), Pacific NW Natl Lab, 902 Batelle Blvd,POB 989,MS P7 28, Richland, WA 99354 USA. EM john.geeting@pnl.gov OI Peterson, Reid/0000-0003-3368-1896 NR 8 TC 4 Z9 4 U1 0 U2 0 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 11 BP 2313 EP 2324 DI 10.1080/01496390600742591 PG 12 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 069MU UT WOS:000239452500002 ER PT J AU Wilmarth, WR Mills, JT Dukes, VH Sullivan, RC AF Wilmarth, W. R. Mills, J. T. Dukes, V. H. Sullivan, R. C. TI Effects of in-tank precipitation of sodium aluminosilicate on uranium chemistry SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article DE occulusion; solubility; speciation AB Experiments have been conducted to examine the fate of uranium during the formation of sodium aluminosilicate (NAS) when wastes containing high aluminate concentrations are mixed with wastes of high silicate concentration. Testing was conducted at varying degrees of uranium saturation. Testing examined typical tank conditions, e.g., stagnant, slightly elevated temperature (50 degrees C). The results showed that under sub-saturated conditions uranium is not removed from solution to any large extent in both simulant testing and actual tank waste testing. This aspect was not thoroughly understood prior to this work and was necessary to avoid criticality issues when actual tank wastes were aggregated. There are data supporting a small removal due to sorption of uranium on sites in the NAS. Above the solubility limit the data are clear that a reduction in uranium concentration occurs concomitant with the formation of aluminosilicate. This uranium precipitation is fairly rapid and ceases when uranium reaches its solubility limit. At the solubility limit, it appears that uranium is not affected, but further testing might be warranted. C1 Westinghouse Savannah River Co, Savannah River Natl Lab, Aiken, SC 29808 USA. RP Wilmarth, WR (reprint author), Westinghouse Savannah River Co, Savannah River Natl Lab, Aiken, SC 29808 USA. EM bill.wilmarth@srnl.doe.gov NR 17 TC 0 Z9 0 U1 1 U2 4 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 11 BP 2325 EP 2340 DI 10.1080/01496390600743011 PG 16 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 069MU UT WOS:000239452500003 ER PT J AU Peterson, RA Fiskum, SK Arm, ST Blanchard, DL AF Peterson, R. A. Fiskum, S. K. Arm, S. T. Blanchard, D. L., Jr. TI Cesium removal demonstration using selected actual waste samples from the Hanford reservation tank farm SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article DE cesium; ion exchange; nuclear waste AB Approximately 40 million curies of Cs-137 are currently contained in High Level Waste stored in 177 underground storage tanks at the Hanford Nuclear Reservation near Richland, Washington. A series of actual waste, small-scale column tests were performed to evaluate the performance of a selected ion exchange resin for cesium removal from a range of planned feed streams. These tests demonstrated that the selected cationic resin-SuperLig 644 trademark -has more than adequate resin capacity to treat each of three potential feed streams. Furthermore, tests indicate an acceptable mass transfer zone for each of the three types of feed material, and that the elution of the resin can be accommodated within the design criteria for the proposed Waste Treatment Plant. C1 Battelle Pacific NW Div, Richland, WA 99354 USA. RP Peterson, RA (reprint author), Battelle Pacific NW Div, 902 Battelle Blvd, Richland, WA 99354 USA. EM reid.peterson@pnl.gov OI Peterson, Reid/0000-0003-3368-1896 NR 4 TC 4 Z9 4 U1 0 U2 2 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 11 BP 2361 EP 2371 DI 10.1080/01496390600742922 PG 11 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 069MU UT WOS:000239452500005 ER PT J AU Burgeson, IE Deschane, JR Cook, BJ Blanchard, DL Weier, DL AF Burgeson, I. E. Deschane, J. R. Cook, B. J. Blanchard, D. L., Jr. Weier, D. L. TI Evaluation of elution parameters for cesium ion exchange resins SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article DE ion exchange; cesium; elution; resorcinol; formaldehyde; SuperLig (R) 644 ID REMOVAL AB Cesium ion exchange is one of the planned processes for treating and disposing of waste at the U.S. Department of Energy Hanford Site. Radioactive supernatant liquids from the waste tanks will undergo ultrafiltration, followed by cesium ion exchange using a regenerable organic ion exchange resin. Two resins, SuperLig trademark 644 and a resorcinol-formaldehyde resin, are being evaluated for cesium removal and cesium elution characteristics. The main purpose of this study is to optimize the cesium elution to provide a resin that, after undergoing elution, would meet the U.S. Department of Energy/Office of River Protection Project-Waste Treatment Plant processing and resin disposal criteria. Columns of each resin type were loaded to greater or equal to 90% breakthrough with a Hanford waste stimulant and eluted with nitric acid. The temperature, flow rate, and nitric acid concentration were varied to determine the optimal elution conditions. Temperature and eluant flow rate were the most important elution parameters. As would be predicted based upon kinetic consideration alone, decreasing the eluant flow rate and increasing the temperature provided the optimal elution conditions. Varying the nitric acid concentration did not have a significant effect on the elution completion; however, elutions performed using both high acid concentration (1 M) and elevated temperature (45 degrees C) resulted in resin degradation, causing gas generation and resin bed disruption. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Burgeson, IE (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. EM ingrid.burgeson@pnl.gov NR 16 TC 9 Z9 9 U1 1 U2 3 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 11 BP 2373 EP 2390 DI 10.1080/01496390600744423 PG 18 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 069MU UT WOS:000239452500006 ER PT J AU Brooks, KP Augspurger, BS Blanchard, DL Cuta, JM Fiskum, SK Thorson, MR AF Brooks, K. P. Augspurger, B. S. Blanchard, D. L. Cuta, J. M. Fiskum, S. K. Thorson, M. R. TI Hydraulic testing of ion exchange resins for cesium removal from Hanford tank waste SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article DE organic ion exchange resins; hydraulic tests; permeability; compressibility AB The granular ion exchange resin SuperLig (TM) 644 is the ion exchange resin of choice for Cs-137 separation from Hanford tank wastes. Current testing activities are evaluating both ground gel and spherical resorcinol-formaldehyde (RF) resins as alternatives to the sole-source supplied SL-644 while achieving comparable loading and elution performance. The purpose of this testing was then to compare the bed forces, resin particle breakage, and differential pressure across the resin bed during multiple load-elute cycles. These tests were conducted in a small-scale column with high flow rates to simulate the hydraulic conditions that would be experienced in a full-scale column. C1 Battelle Pacific NW Div, Richland, WA 99352 USA. Bechtel Natl Corp, Richland, WA USA. RP Brooks, KP (reprint author), Battelle Pacific NW Div, Mail Stop K6-24,POB 999, Richland, WA 99352 USA. EM kriston.brooks@pnl.gov NR 5 TC 4 Z9 4 U1 2 U2 2 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 11 BP 2391 EP 2408 DI 10.1080/01496390600742724 PG 18 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 069MU UT WOS:000239452500007 ER PT J AU Peters, TB Barnes, MJ Hobbs, DT Walker, DD Fondeur, FF Norato, MA Fink, SD Pulmano, RL AF Peters, T. B. Barnes, M. J. Hobbs, D. T. Walker, D. D. Fondeur, F. F. Norato, M. A. Fink, S. D. Pulmano, R. L. TI Strontium and actinide separations from high level nuclear waste solutions using monosodium titanate 2. Actual waste testing SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article DE sorption; ion exchange; strontium; plutonium; neptunium; uranium AB Pretreatment processes at the Savannah River Site will separate Sr-90, alpha-emitting and radionuclides (i.e., actinides) and Cs-137 prior to disposal of the high-level nuclear waste. Separation of Sr-90 and alpha-emitting radionuclides occurs by ion exchange/adsorption using an inorganic material, monosodium titanate (MST). Previously reported testing with simulants indicates that the MST exhibits high selectivity for strontium and actinides in high ionic strength and strongly alkaline salt solutions. This paper provides a summary of data acquired to measure the performance of MST to remove strontium and actinides from actual waste solutions. These tests evaluated the effects of ionic strength, mixing, elevated alpha activities, and multiple contacts of the waste with MST. Tests also provided confirmation that MST performs well at much larger laboratory scales (300 - 700 times larger) and exhibits little affinity for desorption of strontium and plutonium during washing. C1 Westinghouse Savannah River Co, Savannah River Natl Lab, Aiken, SC 29808 USA. BP W Coast Prod LLC, Carson, CA USA. RP Hobbs, DT (reprint author), Westinghouse Savannah River Co, Savannah River Natl Lab, Aiken, SC 29808 USA. EM david.hobbs@srnl.doe.gov NR 11 TC 18 Z9 19 U1 1 U2 11 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 11 BP 2409 EP 2427 DI 10.1080/01496390600742963 PG 19 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 069MU UT WOS:000239452500008 ER PT J AU Fondeur, FF Hobbs, DT Barnes, MJ Peters, TB Fink, SD AF Fondeur, F. F. Hobbs, D. T. Barnes, M. J. Peters, T. B. Fink, S. D. TI Kinetics and equilibrium sorption models: Fitting plutonium, strontium, uranium, and neptunium loading on monosodium titanate (MST) SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article DE actinide; sorption; sodiumtitanate ID ADSORPTION; REMOVAL; IONS AB The Dubinin-Astashov (DA) isotherm parameters for U, Pu, Sr, and Np have been updated to include additional data obtained since the original derivation. The DA isotherms were modified to include a kinetic function derived by Rahn to describe sorbate loading from the beginning of sorption up to steady state. The final functions describe both kinetic and thermodynamic sorption. C1 Westinghouse Savannah River Co, Savannah River Natl Lab, Aiken, SC 29808 USA. RP Fondeur, FF (reprint author), Westinghouse Savannah River Co, Savannah River Natl Lab, 773A,B124, Aiken, SC 29808 USA. EM fernando.fondeur@srnl.doe.gov NR 14 TC 1 Z9 1 U1 2 U2 6 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 11 BP 2429 EP 2445 DI 10.1080/01496390600745495 PG 17 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 069MU UT WOS:000239452500009 ER PT J AU Peters, TB Hobbs, DT Fink, SD AF Peters, T. B. Hobbs, D. T. Fink, S. D. TI Determination of actinide loadings onto monosodium titanate (MST) under conditions relevant to the actinide removal process facility SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article DE actinide strontium removal; MST AB Researchers at the Savannah River Site (SRS) have studied adsorption of uranium, plutonium, and neptunium onto monosodium titanate (MST) at conditions relevant to operation of the Actinide Removal Process (ARP) facility. This study measured actinide loadings at a large phase ratio of simulated wastes solution to mass of MST. The large phase ratio was designed to mimic the maximum phase ratio that would occur during a single process cycle of the ARP facility. Uranium and plutonium loadings measured in this study proved much higher than previous measurements at lower phase ratios. C1 Westinghouse Savannah River Co, Savannah River Natl Lab, Aiken, SC 29808 USA. RP Peters, TB (reprint author), Westinghouse Savannah River Co, Savannah River Natl Lab, Aiken, SC 29808 USA. EM thomas.peters@srnl.doe.gov NR 11 TC 2 Z9 2 U1 0 U2 2 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 11 BP 2447 EP 2460 DI 10.1080/01496390600743094 PG 14 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 069MU UT WOS:000239452500010 ER PT J AU Fiskum, SK Blanchard, DL Steele, MJ Thomas, KK Trang-Le, T Thorson, MR AF Fiskum, S. K. Blanchard, D. L. Steele, M. J. Thomas, K. K. Trang-Le, T. Thorson, M. R. TI Spherical resorcinol-formaldehyde resin testing for cesium removal from Hanford tank waste simulant SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article DE resorcinol-formaldehyde resin; SuperLig (R) 644; cesium ion exchange; Hanford tank waste ID ION-EXCHANGE AB A new spherical form of resorcinol-formaldehyde (RF) resin was tested for efficacy of cesium removal from Hanford tank waste. Two spherical RF formulations, prepared by varying curing temperature, were tested. Both resins had a tight particle size distribution and a high degree of sphericity. Small-scale column testing (on similar to 20-mL resin beds) was conducted evaluating the cesium load profile with AZ-102 simulated tank waste and the cesium elution profile using 0.5 M HNO3 eluant. The load and elution profiles were compared in side-by-side testing with ground-gel RF resin and SuperLig (TM) 644, the Waste Treatment Plant baseline ion exchanger. Although breakthrough capacity was not as high as the other resins tested, the spherical RF resin met plant cesium loading requirements with the AZ-102 simulant matrix. Excellent reproducibility of cesium load and elution was demonstrated over three process cycles with no evidence of degraded performance. Residual cesium on the resin beds after elution was nearly a factor of 10 lower than that of the ground-gel RF and SuperLig trademark 644. C1 Battelle Pacific NW Div, Richland, WA 99352 USA. Washington Grp Int, Richland, WA USA. RP Fiskum, SK (reprint author), Battelle Pacific NW Div, P7-22,POB 999, Richland, WA 99352 USA. EM sandyfiskum@pnl.gov NR 12 TC 8 Z9 8 U1 3 U2 7 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 11 BP 2461 EP 2474 DI 10.1080/01496390600742740 PG 14 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 069MU UT WOS:000239452500011 ER PT J AU King, WD Fondeur, FF Wilmarth, WR Pettis, ME McCollum, SW AF King, William D. Fondeur, Fernando F. Wilmarth, William R. Pettis, Myra E. McCollum, Shirley W. TI Reactivity of resorcinol formaldehyde resin with nitric acid SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article DE RF; spherical resin; nitration; oxidation; IR; DSC AB Solid-state infrared spectroscopy, differential scanning calorimetry, and elemental analysis have been used to evaluate the reactivity of resorcinol formaldehyde resin with nitric acid and characterize the solid product. Two distinct reactions were identified within the temperature range 25-55 degrees C. The first reaction is primarily associated with resin nitration, while the second involves bulk oxidation and degradation of the polymer network leading to dissolution and off-gassing. Reaction was confirmed with nitric acid concentrations as low as 3 M at 25 degrees C applied temperature and 0.625 M at 66 degrees C. Although a nitrated resin product can be isolated under appropriate experimental conditions, calorimetry testing indicates no significant hazard associated with handling the dry material. C1 Westinghouse Savannah River Co, Savannah River Natl Lab, Aiken, SC 29808 USA. RP King, WD (reprint author), Westinghouse Savannah River Co, Savannah River Natl Lab, Aiken, SC 29808 USA. EM king@srnl.doe.gov NR 12 TC 1 Z9 1 U1 1 U2 4 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 11 BP 2475 EP 2486 DI 10.1080/01496390600743151 PG 12 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 069MU UT WOS:000239452500012 ER PT J AU Taylor, P AF Taylor, Paul TI Removal of trace concentrations of heavy metals using complexing ion-exchange resins SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article DE wastewater; treatment; ion exchange resin; mercury; uranium; radionuclides AB Oak Ridge National Laboratory is examining potential new technologies for treating radiologically-contaminated process wastewater. The current treatment facility is aging and is optimized to remove Sr-90, but future wastewaters are likely to contain mostly activated metals, such as Cr-51 and Cu-64. Other low-volume wastewaters may contain trace concentrations of Hg and U. Complexing ion-exchange resins and other specialized sorbents were tested for removing trace concentrations of heavy metals. Short-term column tests and batch loading tests were conducted using a surrogate wastewater and various sorbents. These tests showed that metal uptake was very rapid, and that good removal and relatively high loadings could be achieved from a very dilute wastewater surrogate. Forager M-TU (Dynaphore, Inc.) showed the best overall results, removing 91.9% of the Cr, 99.3% of the Cu, > 99.7% of the Hg, and > 99.9% of the U with a contact time of 120 seconds in a short-term column test. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Taylor, P (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. EM taylorpa@ornl.gov NR 5 TC 3 Z9 4 U1 1 U2 3 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 11 BP 2575 EP 2579 DI 10.1080/01496390600742658 PG 5 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 069MU UT WOS:000239452500017 ER PT J AU Rains, WO Counce, RM AF Rains, William O. Counce, Robert M. TI Liquidus curves of NH4NO3 (aq) calculated from the modified adsorption isotherm model for aqueous electrolytes SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article DE activity coefficients; aqueous electrolyte; Brunauer-Emmett-Teller (BET); absorption isotherm; eutectic ID CONCENTRATED-SOLUTIONS; BET MODEL; WATER; SALT AB The Stokes-Robinson modification of the Brunauer-Emmett-Teller (BET) adsorption isotherm is used to calculate the liquidus curve of NaNO3 (aq) including the eutectic point and metastable phases. The method described here represents a simplified approach to predict the liquidus curves with sparse information and considers the presence of several crystalline solid phases of NH4NO3 . C1 Oak Ridge Natl Lab, Nucl Sci & Technol Div, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. RP Counce, RM (reprint author), Oak Ridge Natl Lab, Nucl Sci & Technol Div, Oak Ridge, TN 37831 USA. EM counce@utk.edu NR 15 TC 4 Z9 4 U1 1 U2 2 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 11 BP 2629 EP 2634 DI 10.1080/01496390600743045 PG 6 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 069MU UT WOS:000239452500021 ER PT J AU Davis, AN Morton, SA Counce, RM DePaoli, DW Hu, MZC AF Davis, Alison N. Morton, Samuel A., III Counce, Robert M. DePaoli, David W. Hu, Michael Z. -C. TI Effect of ionic strength on oil removal from stainless steel in the presence of ionic surfactant SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article DE surfactant; ionic strength; contact angle; aqueous cleaning ID CONTACT-ANGLE; SOLID-SURFACES; ADSORPTION; DROPLETS; CLASSIFICATION; DETACHMENT; PREDICTION; ROUGHNESS; PH AB Contact angles of oil droplets on solid surfaces provide useful insight into surfactant cleaning behavior. Contact angles of hexadecane and MAR-TEMP (R) 355, an industrial quench oil, on stainless steel were measured for ionic surfactant solutions as a function of ionic strength. The ionic strength of sodium dodecyl sulfate (SDS) and cetyl trimethyl ammonium bromide (CTAB) solutions was modified by the addition of sodium chloride. Increases in the contact angle with additions of 1.0 mM and 2.5 mM NaCl were observed for the two oils in SDS and for hexadecane in CTAB. For the industrial quench oil, detachment occurred in CTAB concentrations above the critical micelle concentration; as a result, the equilibrium contact angle measurements were not measured. The critical concentration of CTAB decreased with increasing NaCl concentration. Oil-removal studies indicate that increasing ionic strength by as little as 2.5 mM can result in improved cleaning. C1 Univ Tennessee, Knoxville Dept Chem Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Separat & Mat Res Grp, Oak Ridge, TN USA. RP Counce, RM (reprint author), Univ Tennessee, Knoxville Dept Chem Engn, Knoxville, TN 37996 USA. EM counce@utk.edu OI Hu, Michael/0000-0001-8461-9684 NR 25 TC 5 Z9 5 U1 2 U2 12 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2006 VL 41 IS 15 BP 3313 EP 3328 DI 10.1080/01496390600915049 PG 16 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 100PL UT WOS:000241680900002 ER PT S AU Nash, KL Lumetta, GJ Clark, SB Friese, J AF Nash, Kenneth L. Lumetta, Gregg J. Clark, Sue B. Friese, Judah BE Lumetta, GJ Nash, KL Clark, SB Friese, JI TI Significance of the nuclear fuel cycle in the 21st century SO SEPARATIONS FOR THE NUCLEAR FUEL CYCLE IN THE 21ST CENTURY SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Separations for the Nuclear Fuel Cycle held at the 227th ACS National Meeting CY MAR 30-APR 01, 2004 CL Anaheim, CA SP Amer Chem Soc, Div Ind & Engn Chem, ACS, Div Nucl Chem & Technol ID EXTRACTION; ELEMENTS AB The combined effects of increasing industrialization around the world, the threat of global climate change, and decreasing availability of "clean" fossil fuels will make the development of alternative energy sources more important in the coming decades. For fission-based nuclear power to contribute significantly to future energy supplies, it will be essential to maintain the improvements that have been made in plant operational efficiency, to license geological repositories for waste disposal, and to consider again the issue of recycling of spent nuclear fuels to recover its fuel value and to reduce the long-term radiotoxicity of the wastes. In this chapter, we present an overview of the nuclear fuel cycle from spent fuel recycling through the repository performance in the context of its importance to energy production in the 21(st) Century. (c) 2006 American Chemical Society C1 Washington State Univ, Dept Chem, Pullman, WA 99164 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Nash, KL (reprint author), Washington State Univ, Dept Chem, POB 644630, Pullman, WA 99164 USA. NR 14 TC 12 Z9 12 U1 0 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3931-2 J9 ACS SYM SER PY 2006 VL 933 BP 3 EP 20 PG 18 WC Chemistry, Multidisciplinary; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA BEW09 UT WOS:000239743000001 ER PT S AU Todd, TA Wigeland, RA AF Todd, T. A. Wigeland, R. A. BE Lumetta, GJ Nash, KL Clark, SB Friese, JI TI Advanced separation technologies for processing spent nuclear fuel and the potential benefits to a geologic repository SO SEPARATIONS FOR THE NUCLEAR FUEL CYCLE IN THE 21ST CENTURY SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Separations for the Nuclear Fuel Cycle held at the 227th ACS National Meeting CY MAR 30-APR 01, 2004 CL Anaheim, CA SP Amer Chem Soc, Div Ind & Engn Chem, ACS, Div Nucl Chem & Technol ID EXTRACTION; SOLVENT; STRONTIUM; CESIUM; WASTE AB The United States Department of Energy's Advanced Fuel Cycle Initiative (AFCI) is developing advanced separation technologies to process spent light water reactor fuel. The purpose of these separation processes is to remove the bulk of the mass of spent nuclear fuel (uranium) and the primary heat generating elements, which limit the amount of material that can be placed in a given amount of repository space. The thermal load to the repository is a function of both short-term heat generating elements, such as the fission products cesium and strontium, and long-term heat generating elements, such as plutonium and americium. For example, calculations of the proposed repository at Yucca Mountain indicate that 99 to 99.9 % removal of these four elements would allow a substantial increase in drift loading in the repository, as much as 50 times greater than for direct disposal of spent fuel. The current AFCI program includes investigation of strategies for the separation of uranium, for low-level waste disposal, and/or for separation and recycle of transuranic elements. Cesium and strontium would be separated for storage (approximately 200-300 years) to allow time for their decay, and would then be disposed as low-level waste. Group separation of actinides, such as neptunium, plutonium, americium and curium, and lanthanides, are also being studied, with interm storage of at least some of the actinides in the repository. These materials would be retrieved at a later date for transmutation in thermal or fast reactors. (c) 2006 American Chemical Society. C1 Idaho Natl Engn Lab, Idaho Falls, ID 83415 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Todd, TA (reprint author), Idaho Natl Engn Lab, POB 1625,MS 3860, Idaho Falls, ID 83415 USA. RI Todd, Terry /O-4930-2016 OI Todd, Terry /0000-0003-1324-6950 NR 25 TC 24 Z9 24 U1 3 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3931-2 J9 ACS SYM SER PY 2006 VL 933 BP 41 EP 55 PG 15 WC Chemistry, Multidisciplinary; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA BEW09 UT WOS:000239743000003 ER PT S AU Bakel, AJ Bowers, DL Quigley, KJ Regalbuto, MC Stillman, JA Vandegrift, GF AF Bakel, Allen J. Bowers, Delbert L. Quigley, Kevin J. Regalbuto, Monica C. Stillman, John A. Vandegrift, George F. BE Lumetta, GJ Nash, KL Clark, SB Friese, JI TI Dissolution of irradiated nuclear fuel from the big rock point reactor SO SEPARATIONS FOR THE NUCLEAR FUEL CYCLE IN THE 21ST CENTURY SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Separations for the Nuclear Fuel Cycle held at the 227th ACS National Meeting CY MAR 30-APR 01, 2004 CL Anaheim, CA SP Amer Chem Soc, Div Ind & Engn Chem, ACS, Div Nucl Chem & Technol ID BEHAVIOR; RESIDUES AB The Advanced Fuel Cycle Initiative (AFCI), funded by the Department of Energy, is developing proliferation-resistant technologies that allow safe and economical disposal of waste from reactors. A critical element is the separation of key radionuclides followed by either waste disposal, or conversion of long-lived isotopes to reactor fuel. A sample of Big Rock Point uranium oxide fuel was dissolved in nitric acid at elevated temperature to provide feedstock for the UREX+ demonstration. Elevated temperature led to the complete dissolution of noble metals at relatively low nitric acid concentrations. The conditions used in this study are not suitable for plant-scale application. Three products were obtained: (1) a dissolved fuel solution, (2) undissolved residue, and (3) leached cladding containing no observable undissolved fuel. Elemental analyses of the dissolved fuel, residue, and leached cladding are presented. The data show that 99% of the fuel, including the noble metals was dissolved. The small amount of residue contained primarily Zr, Mo, and Pu. While the total amount of residue is small, approximately 20% of the total Pu was found in the residue. Several proposals are made for the prevention of precipitation of the residue. (c) 2006 American Chemical Society. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Bakel, AJ (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 19 TC 2 Z9 2 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3931-2 J9 ACS SYM SER PY 2006 VL 933 BP 71 EP 88 PG 18 WC Chemistry, Multidisciplinary; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA BEW09 UT WOS:000239743000005 ER PT S AU Arm, ST Jenkins, JA AF Arm, Stuart T. Jenkins, Jon A. BE Lumetta, GJ Nash, KL Clark, SB Friese, JI TI Haze formation and behavior in liquid-liquid extraction processes SO SEPARATIONS FOR THE NUCLEAR FUEL CYCLE IN THE 21ST CENTURY SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Separations for the Nuclear Fuel Cycle held at the 227th ACS National Meeting CY MAR 30-APR 01, 2004 CL Anaheim, CA SP Amer Chem Soc, Div Ind & Engn Chem, ACS, Div Nucl Chem & Technol AB Aqueous haze formation and behavior was studied in the liquid-liquid system tri-n-butyl phosphate in odorless kerosene and 3M nitric acid with uranyl nitrate and cesium nitrate representing the major solute and an impurity, respectively. A pulsed column, mixer-settler and centrifugal contactor were chosen to investigate the effect of different turbulence characteristics on the manifestation of haze since these contactors exhibit distinct mixing phenomena. The dispersive processes of drop coalescence and breakage, and water precipitation in the organic phase were observed to lead to the formation of haze drops of similar to 1 mu m in diameter. The interaction between the haze and primary drops of the dispersion was critical to the separation efficiency of the liquid-liquid extraction equipment. Conditions of high power input and spatially homogeneous mixing enabled the haze drops to become rapidly assimilated within the dispersion to maximize the scrub performance and separation efficiency of the equipment. (c) 2006 American Chemical Society. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. AEA Technol Plc, Didcot OX11 0QJ, Oxon, England. RP Arm, ST (reprint author), Pacific NW Natl Lab, 902 Battelle Blvd,POB 999, Richland, WA 99352 USA. NR 2 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3931-2 J9 ACS SYM SER PY 2006 VL 933 BP 103 EP 118 PG 16 WC Chemistry, Multidisciplinary; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA BEW09 UT WOS:000239743000007 ER PT S AU Chiarizia, R Jensen, MP Borkowski, M Nash, KL AF Chiarizia, R. Jensen, M. P. Borkowski, M. Nash, K. L. BE Lumetta, GJ Nash, KL Clark, SB Friese, JI TI A new interpretation of third-phase formation in the solvent extraction of actinides by TBP SO SEPARATIONS FOR THE NUCLEAR FUEL CYCLE IN THE 21ST CENTURY SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Separations for the Nuclear Fuel Cycle held at the 227th ACS National Meeting CY MAR 30-APR 01, 2004 CL Anaheim, CA SP Amer Chem Soc, Div Ind & Engn Chem, ACS, Div Nucl Chem & Technol ID ANGLE NEUTRON-SCATTERING; NITRIC-ACID EXTRACTION; 3RD PHASE-FORMATION; N-DODECANE SYSTEM; METHANEDIPHOSPHONIC ACID; SURFACE-ADHESION; BUTYL PHOSPHATE; METAL-CATIONS; BAXTER MODEL; HARD-SPHERES AB Third phase formation, i.e., the separation of a second heavy organic phase, is a largely unexplained phenomenon which is observed in solvent extraction of metal species (for example, in the extraction of actinides by tri-n-butyl phosphate, TBP, in aliphatic diluents). Structural approaches for explaining organic phase splitting, based on concepts borrowed from the field of colloid chemistry, have recently appeared in the literature. In this chapter, we summarize the results of our recent small-angle neutron scattering (SANS) investigation of third phase formation in the extraction of uranyl and thorium nitrates by TBP in n-alkanes. An interpretation of the mechanism of third phase formation, founded on the application of Baxter's "sticky spheres" model, is presented. (c) 2006 American Chemical Society. C1 Argonne Natl Lab, Dept Chem, Argonne, IL 60439 USA. RP Chiarizia, R (reprint author), Argonne Natl Lab, Dept Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Jensen, Mark/G-9131-2012 OI Jensen, Mark/0000-0003-4494-6693 NR 25 TC 2 Z9 2 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3931-2 J9 ACS SYM SER PY 2006 VL 933 BP 135 EP 150 PG 16 WC Chemistry, Multidisciplinary; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA BEW09 UT WOS:000239743000009 ER PT S AU Mullins, D Jarvinen, G Mayne, M Ford, D Long, K Reichert, H Palmer, P Tait, CD Keogh, DW Gordon, P AF Mullins, Don Jarvinen, Gordon Mayne, Michael Ford, Doris Long, Kristy Reichert, Heidi Palmer, Phillip Tait, C. Drew Keogh, D. Webster Gordon, Pamela BE Lumetta, GJ Nash, KL Clark, SB Friese, JI TI Crystallization of uranium complexes for partitioning of spent nuclear fuel SO SEPARATIONS FOR THE NUCLEAR FUEL CYCLE IN THE 21ST CENTURY SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Separations for the Nuclear Fuel Cycle held at the 227th ACS National Meeting CY MAR 30-APR 01, 2004 CL Anaheim, CA SP Amer Chem Soc, Div Ind & Engn Chem, ACS, Div Nucl Chem & Technol AB Previous work in Germany and Japan has indicated that crystallization of uranyl nitrate at low temperatures from nitric acid solution could be a useful process for removing most of the uranium from spent light water reactor (LWR) fuel following the dissolution of the fuel in nitric acid. The crystallization process could potentially reduce the cost of LWR fuel partitioning because it selectively removes most of the uranium which is about 96% of the LWR spent fuel mass (metal basis). Subsequent separation processes would only need to handle the smaller volume of remaining actinides and the fission products. We are evaluating an approach to separating uranyl nitrate from spent fuel dissolver solutions by water and nitric acid distillation, a continuous adiabatic reduced-pressure crystallizer Initial work to define the process flowsheet and obtain data on optimum crystallization conditions and the purity of the uranium product are described. (c) 2006 American Chemical Society. C1 Los Alamos Natl Lab, Nucl Mat & Technol Div, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. RP Mullins, D (reprint author), Los Alamos Natl Lab, Nucl Mat & Technol Div, POB 1663, Los Alamos, NM 87545 USA. NR 10 TC 0 Z9 0 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3931-2 J9 ACS SYM SER PY 2006 VL 933 BP 183 EP 197 PG 15 WC Chemistry, Multidisciplinary; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA BEW09 UT WOS:000239743000012 ER PT S AU Lumetta, GJ McNamara, BK Hubler, TL Wester, DW Li, J Latesky, SL AF Lumetta, Gregg J. McNamara, Bruce K. Hubler, Timothy L. Wester, Dennis W. Li, Jun Latesky, Stan L. BE Lumetta, GJ Nash, KL Clark, SB Friese, JI TI Potential application of Klaui ligands in actinide separations SO SEPARATIONS FOR THE NUCLEAR FUEL CYCLE IN THE 21ST CENTURY SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Separations for the Nuclear Fuel Cycle held at the 227th ACS National Meeting CY MAR 30-APR 01, 2004 CL Anaheim, CA SP Amer Chem Soc, Div Ind & Engn Chem, ACS, Div Nucl Chem & Technol ID RAY CRYSTAL-STRUCTURE; SANDWICH COMPOUNDS; COMPLEXES; TRINUCLEAR; REACTIVITY; ACCURATE; NMR AB We have undertaken a systematic experimental and computational study of the complexation of Cp*Co[P(O)(OR)(2)](3)(-) (Cp* = pentamethylcyclopentadienyl) ligands with f-block metal ions (i.e., lanthanides and actinides). As part of this work, the complexation of La 31 ion with Cp*Co[P(O)(OR)(2)](3)(-) ligands has been studied as the alkyl group was systematically varied from methyl to n-propyl (R = -CH3, -CH2CH3, and -CH2CH2CH3). For ligands in which R = -CH3 or -CH2CH3, complexes with ligand-to-La stoichiometries of 1: 1 and 2:1 were formed. In contrast, only the 1:1 complex was isolated when R=-CH2CH2CH3. Computational modeling indicates that the coordination number for La in the 1:1 and 2:1 complexes is 8 and 9, respectively. A prototypical extraction chromatography resin containing Cp*Co[P(O)(OEt)(2)](3)(-) (1b) has been prepared. The resin consists of 0.75 wt% 1b on Amberlite (R) XAD-7. This resin strongly sorbs Am3+ and Pu4+. The sorption of these ions decreases with increasing nitric acid concentration, but this effect is more pronounced for Am3+. This allows for convenient separation of Am3+ from Pu4+ by simple adjustments in the HNO3 concentration. The tripodal geometry of 1b disfavors the complexation Of UO22+, so sorption of U(VI) by the 1b-containing resin is weak. (c) 2006 American Chemical Society. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Virgin Isl, Div Sci & Math, St Thomas, VI 00802 USA. RP Lumetta, GJ (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. NR 31 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3931-2 J9 ACS SYM SER PY 2006 VL 933 BP 201 EP 218 PG 18 WC Chemistry, Multidisciplinary; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA BEW09 UT WOS:000239743000013 ER PT S AU Stepinski, DC Young, BA Jensen, MP Rickert, PG Dzielawa, JA Dilger, AA Rausch, DJ Dietz, ML AF Stepinski, Dominique C. Young, Blake A. Jensen, Mark P. Rickert, Paul G. Dzielawa, Julie A. Dilger, Andrew A. Rausch, David J. Dietz, Mark L. BE Lumetta, GJ Nash, KL Clark, SB Friese, JI TI Application of ionic liquids in actinide and fission product separations: Progress and prospects SO SEPARATIONS FOR THE NUCLEAR FUEL CYCLE IN THE 21ST CENTURY SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Separations for the Nuclear Fuel Cycle held at the 227th ACS National Meeting CY MAR 30-APR 01, 2004 CL Anaheim, CA SP Amer Chem Soc, Div Ind & Engn Chem, ACS, Div Nucl Chem & Technol ID MODIFIED PUREX SOLVENT; NITRATE MEDIA; TRUEX PROCESS; CROWN-ETHERS; EXTRACTION; STRONTIUM; MECHANISM; WASTE; TBP AB Ionic liquids (ILs), particularly those that are liquid at room temperature, have attracted intense interest as alternatives to conventional organic solvents in a host of synthetic, catalytic, and electrochemical applications. Recently, growing attention has been devoted to their use in separations, typically as replacements for the organic diluents employed in traditional liquid-liquid extraction or membrane-based separations of organic solutes or metal ions. Although studies of the extraction of metal ions into various ILs indicate that these solvents frequently provide extraction efficiencies far greater than those obtained with conventional solvents, other work suggests that they suffer from various drawbacks that could limit their utility as extraction solvents. In this chapter, we examine the viability of ionic liquids as the basis for extraction systems for the separation of actinides and fission products from acidic media and consider approaches by which their limitations may be overcome. (c) 2006 American Chemical Society. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Stepinski, DC (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Jensen, Mark/G-9131-2012 OI Jensen, Mark/0000-0003-4494-6693 NR 23 TC 15 Z9 16 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3931-2 J9 ACS SYM SER PY 2006 VL 933 BP 233 EP 247 PG 15 WC Chemistry, Multidisciplinary; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA BEW09 UT WOS:000239743000015 ER PT S AU Peterman, DR Law, JD Todd, TA Tillotson, RD AF Peterman, Dean R. Law, Jack D. Todd, Terry A. Tillotson, Richard D. BE Lumetta, GJ Nash, KL Clark, SB Friese, JI TI Use of Cyanex-301 for separation of Am/Cm from lanthanides in an advanced nuclear fuel cycle SO SEPARATIONS FOR THE NUCLEAR FUEL CYCLE IN THE 21ST CENTURY SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Separations for the Nuclear Fuel Cycle held at the 227th ACS National Meeting CY MAR 30-APR 01, 2004 CL Anaheim, CA SP Amer Chem Soc, Div Ind & Engn Chem, ACS, Div Nucl Chem & Technol ID PURIFIED CYANEX-301; EXTRACTION AB As part of the Advanced Fuel Cycle Initiative (AFCI), technologies for advanced aqueous processing of spent LWR fuel are being developed. Included in this program is the separation of Am and Cm from the lanthanides. This separation would allow the Am/Cm to be fabricated into a target and recycled to a reactor and the lanthanides to be disposed of with the raffinates from the process. A Laboratory Directed Research and Development (LDRD) Project at the INEEL is investigating the use of the active extractant in the Cyanex-301 reagent, bis(2,4,4-trimethylpentyl)dithiophosphinic acid, as a potential method to accomplish this separation. Specifically, the extractant is being developed based on an ammonium acetate/acetic acid buffered feed to the process which can be used to strip the actinides and lanthanides from a preceding transuranic separation process. The extraction and scrub distribution coefficients of Am and Eu with this extractant, as a function of total acetate concentration and pH, have been measured. Additionally, the extraction behavior of several additional lanthanides are compared. The potential for developing a Cyanex-301 process for the separation of Am/Cm from lanthanides to support an advanced nuclear fuel cycle is discussed. (c) 2006 American Chemical Society. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Peterman, DR (reprint author), Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. RI Todd, Terry /O-4930-2016; OI Todd, Terry /0000-0003-1324-6950; Law, Jack/0000-0001-7085-7542 NR 6 TC 4 Z9 4 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3931-2 J9 ACS SYM SER PY 2006 VL 933 BP 251 EP 259 PG 9 WC Chemistry, Multidisciplinary; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA BEW09 UT WOS:000239743000016 ER PT S AU Friese, JI Douglas, M Jerden, JL AF Friese, Judah I. Douglas, Matthew Jerden, James L., Jr. BE Lumetta, GJ Nash, KL Clark, SB Friese, JI TI Neptunium association with selected uranyl phases anticipated in the Yucca Mountain repository SO SEPARATIONS FOR THE NUCLEAR FUEL CYCLE IN THE 21ST CENTURY SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Separations for the Nuclear Fuel Cycle held at the 227th ACS National Meeting CY MAR 30-APR 01, 2004 CL Anaheim, CA SP Amer Chem Soc, Div Ind & Engn Chem, ACS, Div Nucl Chem & Technol ID BEARING URANIUM-OXIDES; SPENT NUCLEAR-FUEL; OXIDIZING CONDITIONS; OXIDATIVE CORROSION; METASCHOEPITE; 90-DEGREES-C; MECHANISMS; MINERALS; STUDTITE; UO2 AB Spent nuclear fuel (SNF) in the United States is planned to be permanently stored in a geological respository located at Yucca Mountain. Under the anticipated moist, oxidizing environment, a suite of secondary uranium solids is expected to form, which will likely impact the release and potential mobility of other radionuclides contained in the SNF. This chapter provides a summary of selected studies of neptunium (Np) with three phases suggested likely to form under the anticipated respository conditions: metaschoepite ([(UO2)(8)O-2(OH)(12)]center dot 10H(2)O), (alpha-uranophane (Ca[(UO2) (SiO3OH)](2)center dot 5H(2)O), and studtite (UO4 center dot 4H(2)O). Results suggest that uranophane and studtite have a higher capacity for neptunium association than metaschoepite, although uptake of Np by metaschoepite increases proportionally to the quantity of Na included in the synthesis. The release of Np into solution from batch dissolution studies exceeded congruent release with uranium for the uranophane and studtite solid phases. Ultimately, the mechanism of Np association with these phases is inconclusive and further studies will need to be conducted to answer this important question. (c) 2006 American Chemical Society. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Friese, JI (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. OI Douglas, Matthew/0000-0001-9708-1780 NR 25 TC 2 Z9 2 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3931-2 J9 ACS SYM SER PY 2006 VL 933 BP 293 EP 312 PG 20 WC Chemistry, Multidisciplinary; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA BEW09 UT WOS:000239743000019 ER PT S AU Wall, DE Wall, NA Brush, LH AF Wall, Donald E. Wall, Nathalie A. Brush, Laurence H. BE Lumetta, GJ Nash, KL Clark, SB Friese, JI TI Speciation and solubility modeling of actinides in the waste isolation pilot plant SO SEPARATIONS FOR THE NUCLEAR FUEL CYCLE IN THE 21ST CENTURY SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Separations for the Nuclear Fuel Cycle held at the 227th ACS National Meeting CY MAR 30-APR 01, 2004 CL Anaheim, CA SP Amer Chem Soc, Div Ind & Engn Chem, ACS, Div Nucl Chem & Technol ID CONCENTRATED SALT-SOLUTIONS; INTERACTION PITZER PARAMETERS; U(IV) HYDROUS OXIDES; HIGH IONIC-STRENGTH; AQUEOUS THERMODYNAMICS; CHLORIDE COMPLEXATION; ELECTROLYTE-SOLUTIONS; TRIVALENT ACTINIDES; NA2CO3 SOLUTIONS; NATURAL-WATERS AB The WIPP geochemical model uses the Pitzer equations coupled to a thermodynamic database to carry out speciation and solubility calculations for the actinides in the +III, +IV, and +V oxidation states in aqueous systems composed of Na+-K+-Mg2+-Ca2+-SO42--OH--CO32--HCO3--H2O-acetate-citrate-oxalate-EDTA. The WIPP database incorporates results for actinide speciation and complexation work carried out primarily at Pacific Northwest National Laboratory, Forschungszentrum Karlsruhe (Germany) and Florida State University. Calculations are performed at Sandia National Laboratories with the code FMT, using the Harvie-Moller-Weare database, and parameters that were developed specifically for actinides in high ionic strength aqueous solutions. This paper describes derivation of the thermodynamic database, and provides normalized standard chemical potentials and Pitzer parameters for modeling An(III, IV, and V) speciation and solubility in brines. (c) 2006 American Chemical Society. C1 Sandia Natl Labs, Carlsbad Programs Grp, Carlsbad, NM 88220 USA. RP Wall, DE (reprint author), Sandia Natl Labs, Carlsbad Programs Grp, Carlsbad, NM 88220 USA. NR 47 TC 0 Z9 0 U1 2 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA SN 0097-6156 BN 0-8412-3931-2 J9 ACS SYM SER PY 2006 VL 933 BP 313 EP 334 PG 22 WC Chemistry, Multidisciplinary; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA BEW09 UT WOS:000239743000020 ER PT S AU Freeman, T Keahey, K Foster, I Rana, A Sotomoayor, B Wuerthwein, F AF Freeman, T. Keahey, K. Foster, I. Rana, A. Sotomoayor, B. Wuerthwein, F. BE Dan, A Lamersdorf, W TI Division of labor: Tools for growing and scaling Grids SO SERVICE ORIENTED COMPUTING - ICSOC 2006, PROCEEDINGS SE Lecture Notes in Computer Science LA English DT Proceedings Paper CT 4th International Conference on Service-Oriented Computing CY DEC 04-07, 2006 CL Chicago, IL DE virtualization; grid computing; resource management; distributed computing AB To enable Grid scalability and growth, a usage model has evolved whereby resource providers make resources available not to individual users directly, but rather to larger units, called virtual organizations. In this paper, we describe abstractions that allow resource providers to delegate the usage of remote resources dynamically to virtual organizations in application-independent ways, and present and evaluate an implementation of this abstraction using the Xen virtual machine and Linux networking tools. We also describe how our implementation is being used in a specific context, namely the enforcement of resource allocations in the Edge Services Framework, currently deployed in the Open Science Grid. C1 [Foster, I.; Sotomoayor, B.] Univ Chicago, Computat Inst, Chicago, IL 60637 USA. [Freeman, T.; Keahey, K.; Foster, I.] Univ Chicago, Comp Inst, Chicago, IL USA. [Freeman, T.; Keahey, K.; Foster, I.] Argonne Natl Lab, Chicago, IL USA. [Keahey, K.; Foster, I.] Argonne Natl Lab, Math & Comp Sci Div, Argonne, IL USA. [Rana, A.; Wuerthwein, F.] Univ Calif, Dept Phys, San Diego, CA USA. RP Freeman, T (reprint author), Univ Chicago, Computat Inst, Chicago, IL 60637 USA. EM freeman@mcs.anl.gov; keahey@mcs.anl.gov; foster@mcs.anl.gov; rana@ucsd.edu; borja@mcs.anl.gov; fkw@ucsd.edu FU NSF CSR [527448]; Mathematical, Information, and Computational Sciences Division sub program of the Office of Advanced Scientific Computing Research; SciDAC Program, Office of Science, U.S. Department of Energy [W-31-109-ENG-38] FX This work was supported by NSF CSR award #527448 and, in part, by the Mathematical, Information, and Computational Sciences Division sub program of the Office of Advanced Scientific Computing Research, SciDAC Program, Office of Science, U.S. Department of Energy, under Contract W-31-109-ENG-38 NR 24 TC 4 Z9 4 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 978-3-540-68147-2 J9 LECT NOTES COMPUT SC PY 2006 VL 4294 BP 40 EP + PG 3 WC Computer Science, Theory & Methods SC Computer Science GA BFT32 UT WOS:000244496000004 ER PT S AU Berman, GP Bishop, AR Chernobrod, BM Hawley, ME Brown, GW Tsifrinovich, VI AF Berman, Gennady P. Bishop, Alan R. Chernobrod, Boris M. Hawley, Marilyn E. Brown, Geoffrey W. Tsifrinovich, Vladimir I. BE Bird, JP TI Measurement of single electron and nuclear, spin states based on optically detected magnetic resonance SO Seventh International Conference on New Phenomena in Mesoscopic Structures and Fifth International Conference on Surfaces and Interfaces of Mesoscopic Devices, 2005 SE JOURNAL OF PHYSICS CONFERENCE SERIES LA English DT Proceedings Paper CT 7th International Conference on New Phenomena in Mesoscopic Structures/5th International Conference on Surfaces and Interfaces of Mesoscopic Devices CY NOV 27-DEC 02, 2005 CL Maui, HI SP Off Naval Res, Army Res Off, Arizona State Univ, Japan Soc Promot Sci AB A novel approach for measurement of single electron and nuclear spin states is suggested. Our approach is based on optically detected magnetic resonance in a nano-probe located at the apex of an AFM tip. The method provides single electron spin sensitivity with nano-scale spatial resolution. C1 Los Alamos Natl Lab, Los Alamos, NM 87544 USA. Polytech Univ, Brooklyn, NY 11201 USA. RP Berman, GP (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. NR 5 TC 4 Z9 4 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 38 BP 167 EP 170 DI 10.1088/1742-6596/38/1/040 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology SC Engineering; Science & Technology - Other Topics GA BFZ32 UT WOS:000245589400040 ER PT S AU Berman, GP Bishop, AR Chernobrod, BM Hawley, ME Brown, GW AF Berman, Gennady P. Bishop, Alan R. Chernobrod, Boris M. Hawley, Marilyn E. Brown, Geoffrey W. BE Bird, JP TI Sensitivity analysis of a proposed novel opto-nano-mechanical photodetector for improving the performance of LIDAR and local optical sensors SO SEVENTH INTERNATIONAL CONFERENCE ON NEW PHENOMENA IN MESOSCOPIC STRUCTURES AND FIFTH INTERNATIONAL CONFERENCE ON SURFACES AND INTERFACES OF MESOSCOPIC DEVICES, 2005 SE Journal of Physics Conference Series LA English DT Proceedings Paper CT 7th International Conference on New Phenomena in Mesoscopic Structures/5th International Conference on Surfaces and Interfaces of Mesoscopic Devices CY NOV 27-DEC 02, 2005 CL Maui, HI SP Off Naval Res, Army Res Off, Arizona State Univ, Japan Soc Promot Sci ID CANTILEVERS AB We propose a novel approach to the development of a new generation of optical sensors with enhanced detection sensitivity for chemical species. The novelty comes from combining an extremely high Q cantilever sensor with an already well established very sensitive technique, frequency modulation (FM) spectroscopy. In existing implementations, this inherent sensitivity is limited by the inadequacy of current state-of-the-art electronic filters to differentiate the weak amplitude modulated (AM)signal from the inevitable high-frequency laser noise, a consequence of the deterioration in the quality factor with increasing frequency exhibited by these filters. Our approach combines FM techniques with the rapidly advancing technology of nano-mechanical resonator (cantilever) development. Here a cantilever functions as both a sensitive photodetector and a high-quality spectral or temporal filter. These ultra-low mass devices enable detection of the photon momentum rather than conventional detection by photon energy. At least one order of magnitude enhancement appears feasible with existing cantilever technology. C1 [Berman, Gennady P.; Bishop, Alan R.; Chernobrod, Boris M.; Hawley, Marilyn E.; Brown, Geoffrey W.] Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Berman, GP (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EM gpb@lanl.gov NR 4 TC 3 Z9 3 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1742-6588 J9 J PHYS CONF SER PY 2006 VL 38 BP 171 EP + DI 10.1088/1742-6596/38/1/041 PG 2 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology SC Engineering; Science & Technology - Other Topics GA BFZ32 UT WOS:000245589400041 ER PT J AU Farrar, CR Allen, DW Park, G Ball, S Masquelier, MP AF Farrar, Charles R. Allen, David W. Park, Gyuhae Ball, Steven Masquelier, Michael P. TI Coupling sensing hardware with data interrogation software for structural health monitoring SO SHOCK AND VIBRATION LA English DT Article; Proceedings Paper CT 11th International Symposium on Dynamic Problems of Mechanics CY FEB 28-MAR 04, 2005 CL Ouro Preto, BRAZIL SP Brazilian Soc Engn & Mech Sci, Comm Dynam DE sensing; data Interrogation; software; system integration; structural health monitoring AB The process of implementing a damage detection strategy for aerospace, civil and mechanical engineering infrastructure is referred to as structural health monitoring (SHM). The authors' approach is to address the SHM problem in the context of a statistical pattern recognition paradigm. In this paradigm, the process can be broken down into four parts: (1) Operational Evaluation, (2) Data Acquisition and Cleansing, (3) Feature Extraction and Data Compression, and (4) Statistical Model Development for Feature Discrimination. These processes must be implemented through hardware or software and, in general, some combination of these two approaches will be used. This paper will discuss each portion of the SHM process with particular emphasis on the coupling of a general purpose data interrogation software package for structural health monitoring with a modular wireless sensing and processing platform. More specifically, this paper will address the need to take an integrated hardware/software approach to developing SHM solutions. C1 Los Alamos Natl Lab, Engn Inst, Engn Sci & Applicat Div, Los Alamos, NM 87545 USA. Motorola Labs, Los Alamos, NM 87544 USA. RP Farrar, CR (reprint author), Los Alamos Natl Lab, Engn Inst, Engn Sci & Applicat Div, Mail Stop T001, Los Alamos, NM 87545 USA. EM farrar@lanl.gov RI Farrar, Charles/C-6954-2012 NR 13 TC 11 Z9 11 U1 0 U2 1 PU IOS PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 1070-9622 J9 SHOCK VIB JI Shock Vib. PY 2006 VL 13 IS 4-5 BP 519 EP 530 PG 12 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 066EB UT WOS:000239211400022 ER PT S AU Fried, LE Goldman, N Kuo, IFW Mundy, CJ AF Fried, Laurence E. Goldman, Nir Kuo, I-Feng W. Mundy, Christopher J. BE Furnish, MD Elert, M Russell, TP White, CT TI Chemistry of H2O and Hf under extreme conditions SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE H2O; HF; first principles molecular dynamics; superionic phase ID DENSITY-FUNCTIONAL THEORY; LIQUID-HYDROGEN FLUORIDE; EQUATION-OF-STATE; HIGH-PRESSURE; MOLECULAR-DYNAMICS; ELECTRICAL-CONDUCTIVITY; 1ST PRINCIPLES; MELTING CURVE; ICE-VII; WATER AB The predicted high pressure superionic phases of water and HF are investigated via ab initio molecular dynamics. These phases could potentially be achieved through either static compression with heating or through shock compression. We study water at densities of 2.0-3.0 g/cc (34-115 GPa) along the 2000 K isotherm. We find that extremely rapid (superionic) diffusion of protons occurs in a fluid phase at pressures between 34 and 58 GPa. A transition to a stable body-centered cubic (bcc) O lattice with superionic proton conductivity is observed between 70 and 75 GPa, a much higher pressure than suggested in prior work. We find that all molecular species at pressures greater than 75 GPa are too short lived to be classified as bound states. Up to 95 GPa, we find a solid superionic phase characterized by covalent O-H bonding. Above 95 GPa, a transient network phase is found characterized by symmetric O-H hydrogen bonding with nearly 50% covalent character. Ab initio molecular dynamics simulations of HF were conducted at densities of 1.8 - 4.0 g/cc along the 900 K isotherm. According to our simulations, a unique form of (symmetric) hydrogen bonding could play a significant role in superionic conduction. Our work shows that superionic phases could be more prevalent in hydrogen bonded systems than previously thought, such as HCl and HBr. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Fried, LE (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. RI Fried, Laurence/L-8714-2014 OI Fried, Laurence/0000-0002-9437-7700 NR 39 TC 0 Z9 0 U1 1 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 18 EP 25 PN 1&2 PG 8 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600002 ER PT S AU Boettger, JC Honnell, KG Mori, Y Niiya, N Mizuno, T AF Boettger, Jonathan C. Honnell, Kevin G. Mori, Yoshihisa Niiya, Naoto Mizuno, Takafumi BE Furnish, MD Elert, M Russell, TP White, CT TI Theoretical equation of state for beryllium oxide SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE beryllium oxide; equation of state; phase transition; Hugoniot; diamond-anvil cell ID STRUCTURAL PHASE-TRANSFORMATION; HIGH-PRESSURE; THERMAL-EXPANSION; BEO; EXCHANGE; CRYSTALS AB A new, tabular (SESAME format) equation of state for BeO is developed. The new equation of state combines LGA and GGA density-functional predictions for the 0 K isotherm, the Johnson ionic model (which transitions smoothly from Debye behavior in the solid to ideal-gas behavior at high temperatures), and the Thomas-Fermi-Dirac model for thermal electronic contributions. Results for the compressibility, shock Hugoniots, thermal expansion, and heat capacity are in very good agreement with experimental measurements. At room temperature, the theory predicts a wurtzite-to-rock-salt transition at a pressure of 105 GPa, consistent with new XRD diamond-anvil results. C1 Los Alamos Natl Lab, Appl Phys Div, Los Alamos, NM 87545 USA. RP Boettger, JC (reprint author), Los Alamos Natl Lab, Appl Phys Div, MS F699, Los Alamos, NM 87545 USA. NR 34 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 33 EP 36 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600004 ER PT S AU Chesnut, GN Anderson, WW Casson, J AF Chesnut, Gary N. Anderson, William W. Casson, Joanna BE Furnish, MD Elert, M Russell, TP White, CT TI Static x-ray diffraction study of cerium to 330 kilobars SO SHOCK COMPRESSION OF CONDENSED MATTER - 2005, PTS 1 AND 2 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE cerium; diffraction; diamond anvil cell; static ID CRYSTAL-STRUCTURES; PHASE TRANSITION; HIGH-PRESSURE; METAL; GPA; EQUATION AB Cerium is a fascinating f-electron metal with a complex phase diagram. Using the diamond anvil cell and synchrotron x-ray sources we have been able to study cerium to a pressure of 330 kilobars. Radial x-ray diffraction techniques have been used to ensure a more accurate pressure-volume curve at room temperature. Two different purities of cerium (99.9% and 99.99%) have been examined with noticeable differences. This work has produced high quality data that can be used to generate an accurate multi-phase EOS for cerium. The techniques developed in these experiments can further be utilized to obtain accurate EOS data for other materials of interest. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Chesnut, GN (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EM gchesnut@lanl.gov; wvanderson@lanl.gov NR 17 TC 3 Z9 3 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 45 EP 48 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600007 ER PT S AU Chisolm, E Wallace, D AF Chisolm, Eric Wallace, Duane BE Furnish, MD Elert, M Russell, TP White, CT TI Estimating the viscosity coefficient of liquid metals from vibration-transit theory SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE equation of state; self-diffusion coefficient; vibration-transit theory; viscosity coefficient ID TRANSPORT; DYNAMICS AB We describe and test a simple method for calculating the viscosity coefficient eta for liquid metals over a range of densities and temperatures. The method uses a model of atomic motion in a liquid based on the vibration-transit (V-T) theory of liquid dynamics to calculate the self-diffusion coefficient D, and then uses D and the Stokes-Einstein relation to compute eta. We consider the accuracy of both the V-T model for D and the Stokes-Einstein relation; we then compute eta for 21 liquid metals at melt at 1 bar, finding that our results agree with experiment to 18% accuracy. This is somewhat more accurate than other empirical methods and not much less accurate than first principles molecular dynamics calculations, while being substantially less computationally intensive than the latter. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Chisolm, E (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 18 TC 5 Z9 5 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 53 EP 56 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600009 ER PT S AU Clements, BE AF Clements, B. E. BE Furnish, MD Elert, M Russell, TP White, CT TI Low-pressure equation of state of polymers SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE polymers; equation of state; polycarbonate; polytetrafluoroethylene ID HEAT-CAPACITIES AB Low-pressure equations of state (EOS) are constructed for two representative polymers: polycarbonate and polytetrafluorethylene. Our method, which is based on well-known semi-empirical EOS procedures, relies on having heat capacity data at zero pressure, specific volume data as a function of temperature and pressure, and phase diagram information. The resulting equations of state incorporate the glass transition observed for polycarbonate and the solid-solid phase transformations observed in polytetrafluoroethylene. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Clements, BE (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. OI Clements, Brad/0000-0002-9664-637X NR 8 TC 0 Z9 0 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 57 EP 60 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600010 ER PT S AU Crockett, SD Greeff, CW Johnson, JD Burakovsky, L AF Crockett, S. D. Greeff, C. W. Johnson, J. D. Burakovsky, L. BE Furnish, MD Elert, M Russell, TP White, CT TI Testing of a liquid equation of state model against copper data SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter AB We model the free energy of a liquid near melting by postulating that Delta S-V, the entropy difference between solid and liquid at fixed volume, is independent of pressure, and that the melting curve follows the Lindemann law. Using a solid free energy determined from ab initio phonon frequencies, we apply these assumptions to liquid Cu. We show that they are consistent with the Hugoniot sound speed data. We investigate the consequences of typical variations of Delta S-V for shock melting. We also investigate models for the shear modulus and the longitudinal sound speed. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Crockett, SD (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Greeff, Carl/N-3267-2013; OI Greeff, Carl/0000-0003-0529-0441 NR 9 TC 0 Z9 0 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 65 EP 68 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600012 ER PT S AU Dattelbaum, DM Robbins, DL Sheffield, SA Orler, EB Gustavsen, RL Alcon, RR Lloyd, JM Chavez, PJ AF Dattelbaum, D. M. Robbins, D. L. Sheffield, S. A. Orler, E. B. Gustavsen, R. L. Alcon, R. R. Lloyd, J. M. Chavez, P. J. BE Furnish, MD Elert, M Russell, TP White, CT TI Quasi-static and shock compressive response of fluorinated polymers: Kel-F 800 SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE shock compression; polymers; polymer : binder; PBX 9502 AB Fluoropolymers are widely used in a variety of applications due to their favorable properties that include chemical inertness, low coefficient of friction, and ability to withstand high-temperature operating conditions. Additionally, their high densities also make them desirable materials for use as high explosive binders in plastic bonded explosives. Here, we present the first investigation of the dynamic (shock) and static compression behavior of the fluorinated binder poly(chlorotrifluoroethylene-co-vinylidene fluoride) (Kel-F 800). Kel-F 800 samples prepared by both compression molding and melt-processing methods were studied. We observed little difference in the dynamic behavior of the two materials, despite a difference in crystallinity of 10-15%. A linear Rankine-Hugoniot fit to the Hugoniot loci in the U-s-u(p) plane gives U-S = 1.838 + 1.824 u(p). Langrangian sound velocities at pressure were also measured at 3.0 (c(L) = 4.7 mm/mu s) and 4.9 (c(L) = 5.8 min/mu s) GPa. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Dattelbaum, DM (reprint author), Los Alamos Natl Lab, DX-2 Mat Dynam,Mailstop P952, Los Alamos, NM 87545 USA. OI Gustavsen, Richard/0000-0002-2281-2742 NR 7 TC 5 Z9 5 U1 1 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 69 EP 72 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600013 ER PT S AU Koller, DD Rigg, PA Gray, GT Jensen, BJ Hayes, DB Maestas, JD AF Koller, D. D. Rigg, P. A. Gray, G. T., III Jensen, B. J. Hayes, D. B. Maestas, J. D. BE Furnish, MD Elert, M Russell, TP White, CT TI Low pressure hugoniot for U-Nb (6 wt.%) SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE U-Nb (6 wt.%); Hugoniot; elastic; plastic AB Over the last several years, many experiments have been conducted to study the dynamic response of U-Nb (6 wt.%) alloy. An understanding of the physical mechanisms governing the behavior of this material is necessary to develop robust physical models for today's hydrocodes. Previous experiments indicate that the dynamic response of this alloy is strongly dependant on the initial microstructure of the material. Using a well characterized material, a series of low pressure shock experiments were conducted at the single stage light gas gun facility at Los Alamos National Laboratory. Time resolved particle velocity measurements were made using VISAR. Absolute VISAR system timing was measured and cross correlated to shock breakout time to allow hugoniot points to be calculated. These shots provide both low pressure Hugoniot points for U-Nb (6 wt.%) alloy and a better constraint on the dynamic material response. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Koller, DD (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 6 TC 0 Z9 1 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 73 EP 76 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600014 ER PT S AU Greeff, CW Graf, MJ Boettger, JC Johnson, JD AF Greeff, C. W. Graf, M. J. Boettger, J. C. Johnson, J. D. BE Furnish, MD Elert, M Russell, TP White, CT TI High accuracy equations of state for standards SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE equation of state; copper; gold; platinum ID HIGH-PRESSURE; GOLD AB We discuss the development of accurate equations of state by combining electronic structure theory for the lattice vibrations and electronic excitations with an empirical static lattice electronic energy (cold curve). We present applications to the fcc metals Cu, Au, and Pt. We discuss the status of pressure standards. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Greeff, CW (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RI Greeff, Carl/N-3267-2013; OI Greeff, Carl/0000-0003-0529-0441 NR 26 TC 3 Z9 3 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 89 EP 94 PN 1&2 PG 6 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600018 ER PT S AU Reinhart, WA Chhabildas, LC AF Reinhart, W. A. Chhabildas, L. C. BE Furnish, MD Elert, M Russell, TP White, CT TI Response to unloading and reloading of shock compressed polymethyl methacrylate SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE PMMA; polymethyl-methacrylate; reloading; unloading; EOS ID PMMA AB Shock properties of polymeric materials have been investigated at low stresses for use as windows for velocity interferometty, binder phases for polymer-bonded explosives, and as adhesives. The shock Hugoniot for many other polymeric materials may also exist. There are distinct advantages in using a low-impedance polymer for impactors on shock experiments, however the loading structure from reshock or release has not been determined at these high stresses. In this study polymethylmethacrylate (PMMA) is shocked to approximately 45 GPa and recompressed up to 130 GPa as well as unloaded from the shocked state. Reloading and unloading wave speeds have been determined from this initial stress level of approximately 45 GPa. The results from these tests not only characterize PMMA at these stress states, but will be valuable when PMMA is used as a standard material to study strength and phase transformation behavior in other materials. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Reinhart, WA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 13 TC 1 Z9 1 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 131 EP 134 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600028 ER PT S AU Seifter, A Stewart, ST Furlanetto, MR Kennedy, GB Payton, JR Obst, AW AF Seifter, A. Stewart, S. T. Furlanetto, M. R. Kennedy, G. B. Payton, J. R. Obst, A. W. BE Furnish, MD Elert, M Russell, TP White, CT TI Post-shock temperature measurements of aluminum SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE pyrometry; infrared optics; post-shock temperatures; aluminum; equations of state AB Post-shock temperature is an important quantity in shock physics experiments for constraining the dynamic equations of state of materials. A high-speed, infrared, multi-wavelength pyrometer has been developed at Los Alamos National Laboratory (LANL) for measurements in the temperature range from 400 to 1200 K. With customized front end optics, permitting concurrent VISAR measurements in the same optical path, validation experiments on aluminum have been conducted at die new Shock Compression Laboratory at Harvard University. Under < 1 millitorr vacuum, a post-shock temperature of 495 K +/- 30 K was recorded from a polished free surface of aluminum 2024-T4 subject to a peak shock pressure of 34.8 +/- 0.8 GPa, in excellent agreement with the equation of state and previous experiments. C1 Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. RP Seifter, A (reprint author), Los Alamos Natl Lab, Div Phys, P-23, Los Alamos, NM 87545 USA. OI Stewart, Sarah/0000-0001-9606-1593 NR 7 TC 1 Z9 1 U1 2 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 139 EP 142 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600030 ER PT S AU Gustavsen, RL Dattelbaum, DM Orler, EB Hooks, AE Alcon, RR Sheffield, SA Hall, CE Baer, MR AF Gustavsen, R. L. Dattelbaum, D. M. Orler, E. B. Hooks, A. E. Alcon, R. R. Sheffield, S. A. Hall, C. E. Baer, M. R. BE Furnish, MD Elert, M Russell, TP White, CT TI Isentropic compression of nitroplastized estane to approximate to 35 KBAR on the Sandia Z-machine SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE isentropic compression; hydrostatic compression; Z accelerator; explosive binder; CTH AB Nitroplasticized Estane (hereafter NP-Estane) is the plastic binder used to hold HMX grains together in the plastic bonded explosive PBX 9501. It is a mixture of 49 wt. % Estane((R))5703 (BF Goodrich), 49 wt. % Nitroplasticizer (a 50150 eutectic mixture of bis(2,2-dinitropropyl)formal and bis(2,2 dinitropropyl)acetal), and 2 wt. % Irganox((R)) 1010 stabilizer. NP-Estane samples 0.1 - 2 mm thick were prepared by compression molding at 110 degrees C. Hydrostatic compression to 2 kbar was measured at 34, 43, and 53 degrees C. CP was measured at ambient conditions. NP-Estane was also isentropically compressed to approximate to 35 kbar in experiment Z1251 on the Sandia Z-Machine. Profiles of ramp waves transmitted through NP-Estane were measured and compared with a free surface reference profile using Hayes's "Backward" analysis and repeated forward analysis with the CTH hydrocode. The following thermodynamic quantities have been obtained; volume coefficient of thermal expansion alpha = 7.2(10(-4))/C, C-p= 1.76 J/g C, C-V = 1.41 J/g C, isentropic and isothermal bulk moduli,. B-S = 36.4 kbar, B-T = 29.3 kbar, Gruneisen constant Gamma = 1.45. The Z1251 experiment is well fit using a Mie-Gruneisen equation of state with the quadratic U-S-U-P relation, U-S = 1.69+2.7u(P)-(0.7/1.69)u(P)(2)km/s. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Gustavsen, RL (reprint author), Los Alamos Natl Lab, MS P952, Los Alamos, NM 87545 USA. OI Gustavsen, Richard/0000-0002-2281-2742 NR 7 TC 0 Z9 1 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 149 EP 152 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600032 ER PT S AU Shaw, MS Tymczak, CJ AF Shaw, M. Sam Tymczak, C. J. BE Furnish, MD Elert, M Russell, TP White, CT TI Theoretical N-2 Hugoniot using MondoSCF density functional quantum energies and a very efficient Monte Carlo reweighting scheme SO SHOCK COMPRESSION OF CONDENSED MATTER - 2005, PTS 1 AND 2 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE density functional; Monte Carlo; nitrogen ID NITROGEN; COMPRESSION; FLUID AB A Monte Carlo reweighting scheme is used to calculate the Hugoniot of molecular N-2 incorporating very accurate quantum energies. We first determine a reference potential fit to quantum calculations of the anisotropic pair interaction. Then the full many-body energy is evaluated for uncorrelated configurations from an NPT Monte Carlo reference simulation at pressure P-0 and temperature T-0. Each configuration is then reweighted to correspond to the distribution of the full energy at values of P and T chosen to maximize the overlap of the two distributions. Because the configurations are uncorrelated, only a few configurations are needed to give a statistically accurate EOS at P and T. The quantum energy calculations are computer intensive, but tractable due to the linear scaling of the MondoSCF density functional code. The PBE0 density functional is used with a 6-31g** basis set, shown to be convergent in the relevant energy differences. The resulting Hugoniot is in excellent agreement with Hugoniot data up to 40 GPa where N-2 remains molecular. C1 Los Alamos Natl Lab, Grp T 14, Los Alamos, NM 87545 USA. RP Shaw, MS (reprint author), Los Alamos Natl Lab, Grp T 14, MS B214, Los Alamos, NM 87545 USA. EM mss@lanl.gov NR 9 TC 3 Z9 3 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 179 EP 182 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600039 ER PT S AU Brown, EN Rae, PJ Trujillo, CP Dattelbatun, DM Gray, GT Bourne, NK AF Brown, Eric N. Rae, Philip J. Trujillo, Carl P. Dattelbatun, Dana M. Gray, George T., III Bourne, Neil K. BE Furnish, MD Elert, M Russell, TP White, CT TI Shock and recovery of polytetrafluoroethylene above and below the phase II to phase III transition SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE polytetrafluoroethylene; pressure induced phase transitions; shock wave effects ID COMPRESSION; PTFE; EQUATION; STATE AB Polytetrafluoroethylene (PTFE) is a semi-crystalline polymer exhibiting complicated pressure and temperature dependent phases. High strain rate applications in aerospace, defense, and automotive industries have lead to interest in the shock response of PTFE and resulting changes in the polymer structure. Experimental studies on pressure-induced phase transitions using shock-loading techniques and the resulting changes in crystalline structure are presented. Gas launcher experiments were performed on pedigreed PTFE X momentum trapped assemblies with impact pressures from 0.4 to 0.85 GPa to investigate the material response above and-below the phase II to phase III crystalline transition. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Brown, EN (reprint author), Los Alamos Natl Lab, MST-8 MS-G755, Los Alamos, NM 87545 USA. OI Brown, Eric/0000-0002-6812-7820 NR 14 TC 5 Z9 5 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 196 EP 199 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600043 ER PT S AU Clements, BE Mas, EM Plohr, JN Ionita, A Addessio, FL AF Clements, B. E. Mas, E. M. Plohr, J. N. Ionita, A. Addessio, F. L. BE Furnish, MD Elert, M Russell, TP White, CT TI Dynamic response of PBX-9501 through the beta-delta phase transition SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE PBX 9501; HMX; phase transformation ID HMX AB The Gibbs free energies of the 0 and 8 phases of HMX are constructed from zero pressure heat capacity data, specific volume measurements, numerical simulations, and diamond anvil experiments. The free energies provide input into a dynamic phase transition model developed for heterogeneous materials that undergo dynamically driven phase transitions. This model, which uses the method of cells analysis to treat the HMX-polymer binder composite, is used to study dynamically loaded PBX-9501 as it transforms from the beta to the delta phase. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Clements, BE (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. OI Clements, Brad/0000-0002-9664-637X NR 9 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 204 EP 207 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600045 ER PT S AU Harstad, EN Addessio, FL Zuo, QH AF Harstad, E. N. Addessio, F. L. Zuo, Q. H. BE Furnish, MD Elert, M Russell, TP White, CT TI A strength model for materials with phase change SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE phase change; material strength; zirconium; EPIC AB A material strength model has been developed for the deviatoric stress of zirconium. The model takes into account different material properties for each phase and evolves separate yield surfaces for each phase. The strength model is coupled with a free energy approach for the equation of state that is applicable to high-pressure applications. The material model has been implemented into a three-dimensional Lagrangian finite-element code. Results from a simulation of an explosively-loaded plate demonstrate the importance of including phase change in the constitutive model. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Harstad, EN (reprint author), Los Alamos Natl Lab, Div Theoret, Mail Stop B216, Los Alamos, NM 87545 USA. NR 10 TC 3 Z9 3 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 216 EP 219 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600048 ER PT S AU Hawreliak, J Rosolankova, K Belak, JF Collins, G Colvin, J Davies, HM Eggert, JH Germann, TC Holian, B Kalantar, DH Kadau, K Lomdahl, P Lorenzana, HE Sheppard, J Stolken, JS Wark, JS AF Hawreliak, J. Rosolankova, K. Belak, J. F. Collins, G. Colvin, J. Davies, H. M. Eggert, J. H. Germann, T. C. Holian, B. Kalantar, D. H. Kadau, K. Lomdahl, P. Lorenzana, H. E. Sheppard, J. Stolken, J. S. Wark, J. S. BE Furnish, MD Elert, M Russell, TP White, CT TI Shock induced alpha-epsilon phase change in iron: Analysis of MD simulations and experiment. SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE phase-transform; diffraction; simulation ID ABSORPTION FINE-STRUCTURE; X-RAY-DIFFRACTION; MOLECULAR-DYNAMICS; TRANSITION; PRESSURE; CRYSTALS; WAVES AB Multimillion atom non-equilibrium molecular dynamics simulations for shock compressed iron are analyzed using Fourier methods to determine the long scale ordering of the crystal. By analyzing the location of the maxima in k-space we can determine the crystal structure and compression due to the shock. This report presents results from a 19.6GPa simulated shock in single crystal iron and compare them to recent experimental results of shock compressed iron where the crystal structure was determined using in-situ wide angle x-ray diffraction. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Hawreliak, J (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. OI Germann, Timothy/0000-0002-6813-238X NR 11 TC 3 Z9 3 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 220 EP 223 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600049 ER PT S AU Hsiung, LL AF Hsiung, Luke L. BE Furnish, MD Elert, M Russell, TP White, CT TI On the micromechanisms of shock-induced martensitic transformation in tantalum SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE shock compression; tantalum; dislocations; twinning; phase transitions : bcc crystals ID TUNGSTEN ALLOYS AB Shock-induced twinning and martensitic transformation in tantalum, which exhibits no solid-state phase transformation under hydrostatic pressures up to 100 GPa, have been further investigated. Since the volume fraction and size of twin and phase domains are small in scale, they are considered foming by heterogeneous nucleation that is catalyzed by high density lattice dislocations. A dynamic dislocaion mechanism is accordingly proposed based upon the observation of dense dislocation clustering within shock-recovered tantalum. The dense dislocation clustering can cause a significant increase of strain energy in local regions of beta (bcc) matrix, which renders mechanical instability and initiates the nucleation of twin and phase domains through the spontaneous reactions of dislocation dissociation within the dislocation clusters. That is, twin domains can be nucleated within the clusters through the homogeneous dissociation of 1/2 < 111 > dislocations into 1/6 < 111 > partial dislocations, and omega phase domains can be nucleated within the closters through the inhomogeneous dissociation of 1/2 < 111 > dislocations into 1/12 < 111 >, 1/3 < 111 > and 1/12 < 111 > partial dislocations. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Hsiung, LL (reprint author), Lawrence Livermore Natl Lab, POB 808,L-352, Livermore, CA 94551 USA. NR 5 TC 2 Z9 2 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 228 EP 231 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600051 ER PT S AU Jensen, BJ Rigg, PA Knudson, MD Hixson, RS Gray, GT Sencer, BH Cherne, R AF Jensen, B. J. Rigg, P. A. Knudson, M. D. Hixson, R. S. Gray, G. T., III Sencer, B. H. Cherne, Rj. BE Furnish, MD Elert, M Russell, TP White, CT TI Dynamic compression of iron single crystals SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE single crystal iron; shock wave; quasi-isentropic; dynamic compression; Z accelerator ID HIGH-PRESSURE AB Iron undergoes a polymorphic phase transformation from alpha phase (bcc) to the epsilon phase (hcp) when compressed to stresses exceeding 130 kbar. Because the epsilon phase is denser than the alpha phase, a single shock wave is unstable and breaks up into an elastic wave, a plastic wave, and a phase transition wave known as the P2 wave. Although there exists a large body of continuum data related to the phase transition of shocked polycrystalline iron, data for single crystal iron is lacking. Such data are required for a more complete understanding of the response of iron subjected to dynamic loading conditions. The objective of the current work was to obtain wave profiles for iron single crystals, oriented along the [100], [110], and [210] directions, subjected to quasi-isentropic loading using the Sandia Z-machine and shock wave loading through plate impact (LA-UR-05-6624). C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Jensen, BJ (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. OI Cherne, Frank/0000-0002-8589-6058 NR 7 TC 9 Z9 10 U1 2 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 232 EP 235 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600052 ER PT S AU Kadau, K Germann, TC Lomdahl, PS Holian, BL AF Kadau, Kai Germann, Timothy C. Lomdahl, Peter S. Holian, Brad Lee BE Furnish, MD Elert, M Russell, TP White, CT TI Atomistic simulations of shock-induced melting in FE SO SHOCK COMPRESSION OF CONDENSED MATTER - 2005, PTS 1 AND 2 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE shock; single crystals; molecular dynamics; melting; embedded atom method; iron; melting line' ID MOLECULAR-DYNAMICS SIMULATIONS; ORIENTATION DEPENDENCE; PHASE-TRANSITIONS; PERFECT CRYSTALS; WAVES; IRON; CORE AB We report on non-equilibrium and Hugoniostat atomistic simulations of shock-induced melting in Fe single crystals. The large-scale simulations show that the melting pressure varies by less than 10 GPa with the crystallographic shock direction. This is in contrast to a large dependence of more than 50 GPa in Cu. single crystal simulations. The hydrostatic melting curve for the discussed Fe potential is above the shock-induced melting, which we attribute to the large defect concentration produced by the shock wave and the short time scales observed in the simulations. We discuss the different behavior of Fe and Cu and compare our theoretical results to experimental data. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Kadau, K (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EM kkadau@lanl.gov OI Germann, Timothy/0000-0002-6813-238X NR 29 TC 2 Z9 2 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 236 EP 239 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600053 ER PT S AU Kalantar, DH Collins, GW Colvin, JD Davies, HM Eggert, JH Hawreliak, J Lorenzana, HE Meyers, MA Rosolankova, K Schneider, MS Sheppard, J Stolken, JS Wark, JS AF Kalantar, D. H. Collins, G. W. Colvin, J. D. Davies, H. M. Eggert, J. H. Hawreliak, J. Lorenzana, H. E. Meyers, M. A. Rosolankova, K. Schneider, M. S. Sheppard, J. Stoelken, J. S. Wark, J. S. BE Furnish, MD Elert, M Russell, TP White, CT TI Direct observation of the alpha-epsilon transition in shocked single crystal iron SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE in-situ diffraction; laser shocks; phase transformation; iron ID PRESSURE; PHASE AB In-situ x-ray diffraction was used to study the response of single crystal iron under shock conditions. Measurements of the response of [001] iron showed a uniaxial compression of the initially bcc lattice along the shock direction by up to 6% at 13 GPa. Above this pressure, the lattice responded with a further collapse of the lattice by 15-18% and a transformation to the hcp structure. The in-situ measurements are discussed and results summarized. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Kalantar, DH (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Collins, Gilbert/G-1009-2011; Meyers, Marc/A-2970-2016 OI Meyers, Marc/0000-0003-1698-5396 NR 18 TC 0 Z9 0 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 240 EP 243 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600054 ER PT S AU Kane, JO Smith, RF AF Kane, J. O. Smith, R. F. BE Furnish, MD Elert, M Russell, TP White, CT TI Modeling non-equilibrium phase transitions in isentropically compressed Bi SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE phase transitions; rate dependence; Bi; Andrews-Hayes; laser ICE; isentropic compression ID II-LIQUID BISMUTH; INTERFEROMETER AB We report here on modeling of non-equilibrium phase transitions in Bi samples isentropically compressed to 120 GPa by a ramped drive, which is produced using the Janus laser. In the experiments, the Bi samples are attached to windows of LIF or sapphire, and the velocity history of the sample-window interface is recorded with line VISAR. The ID response of the targets is modeled using a multiphase Bi EOS, the Andrews-Hayes method for non-equilibrium transitions, and a Boettger-Wallace kinetics model. The pressure drive is deduced by back integration of VISAR data from shots performed with Al samples. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Kane, JO (reprint author), Lawrence Livermore Natl Lab, L-473,7000 E Ave, Livermore, CA 94551 USA. NR 16 TC 4 Z9 5 U1 1 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 244 EP 247 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600055 ER PT S AU Luo, SN AF Luo, Sheng-Nian BE Furnish, MD Elert, M Russell, TP White, CT TI Limit of superheating and supercooling in solid-liquid transitions SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE superheating; melting; solidification; shock compression; molecular dynamics ID STABILITY LIMIT; TEMPERATURES; CATASTROPHE; NUCLEATION; CRYSTALS; ALUMINUM; STATE AB The inherent free energy barrier to the first-order phase transition may give rise to metastable melting and crystallization, i.e., superheating and supercooling. The systematics for the maximum superheating and supercooling at a given heating or cooling rate have been established based on classical nucleation theory and supercooling experiments. Over-pressurization and over-depressurization are equivalent to superheating and supercooling. The systematics have been demonstrated to be consistent with molecular dynamics simulations, Landau models and experiments. The applications of the systematics include the interpretation of dynamic experiments and molecular dynamics simulations, and the hysteresis method for determining the equilibrium melting temperature and the solid-liquid interfacial energy from superheating or supercooling. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Luo, SN (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 31 TC 0 Z9 0 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 252 EP 257 PN 1&2 PG 6 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600057 ER PT S AU Plohr, JN Clements, BE Addessio, FL AF Plohr, JeeYeon N. Clements, Brad E. Addessio, Frank L. BE Furnish, MD Elert, M Russell, TP White, CT TI Dynamically driven phase transformations in damaged composite materials SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE phase transformation; GMC; composite materials; damage ID MICROMECHANICAL ANALYSIS; MATRIX COMPOSITES; MODEL; TITANIUM AB A model developed for composite materials undergoing dynamicaly driven phase transitions in its constituents [1] has been extended to allow for complex material micro-structure and evolution of damage. In this work, damage is described by interfacial debonding and micro-crack growth. We have applied the analysis to silicon carbide-titanium (SiC-Ti) unidirectional metal matrix composites. In these composites, Ti can undergo a low pressure and temperature solid-solid phase transition. With these extensions we have carried out simulations to study the complex interplay between loading rates, micro-structure, damage, and the thermo-mechanical response of the system as it undergoes a solid-solid phase transitions. C1 LANL, Div Theoret, Los Alamos, NM 87545 USA. RP Plohr, JN (reprint author), LANL, Div Theoret, MS B221, Los Alamos, NM 87545 USA. OI Clements, Brad/0000-0002-9664-637X NR 10 TC 1 Z9 1 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 266 EP 269 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600060 ER PT S AU Setchell, RE Montgomery, ST Cox, DE Anderson, MU AF Setchell, R. E. Montgomery, S. T. Cox, D. E. Anderson, M. U. BE Furnish, MD Elert, M Russell, TP White, CT TI Dielectric properties of PZT 95/5 during shock compression under high electric fields SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE ferroelectrics; phase transitions; dielectric properties AB Shock-induced depoling of the ferroelectric ceramic PZT 95/5 is utilized in pulsed power devices. High electric fields are generated within a normally poled ceramic element when the depoling current is passed through a large load resistor. Under these conditions, a portion of the depoling current is retained on the element electrodes to account for capacitance. This effect is governed by the dielectric properties of both unshocked and shocked PZT 95/5 as the field develops during shock transit. Previous studies proposed either constant or relatively simple relaxing behavior for dielectric properties on either side of the shock front. However, interpretation of the corresponding experiments was complicated by possible field effects on depoling kinetics. Recent studies have used different experimental configurations to better isolate the dielectric behavior. Multiple PZT 95/5 elements are displaced both parallel and perpendicular to the direction of shock motion to allow for sequential charging of unshocked and shocked samples. These experiments show a dielectric behavior for which a simple relaxation model is inadequate. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Setchell, RE (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 6 TC 4 Z9 4 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 278 EP 281 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600063 ER PT S AU Howard, WM Molitoris, JD AF Howard, W. M. Molitoris, J. D. BE Furnish, MD Elert, M Russell, TP White, CT TI Modeling propagation of shock waves in metals SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE hydrodynamics; high pressure effects; equation of state of specific substances AB We present modeling results for the propagation of strong shock waves in metals. In particular, we use an arbitrary Lagrange Eulerian (ALE3D) code to model the propagation of strong pressure waves (P similar to 300 to 400 kbars) generated with high explosives in contact with aluminum cylinders. The aluminum cylinders are assumed to be both flat-topped and have large-amplitude curved surfaces. We use 3D Lagrange mechanics. For the aluminum we use a rate-independent Steinberg-Guinan model, where the yield strength and shear modulus depend on pressure, density and temperature. The calculation of the melt temperature is based on the Lindenuarin law. At melt the yield strength and shear modulus is set to zero. The pressure is represented as a seven-term polynomial as a function of density. For the HMX-based high explosive, we use a JWL, with a program bum model that give the correct detonation velocity and C-J pressure (P similar to 390 kbars). For the case of the large-amplitude curved surface, we discuss the evolving shock structure in terms of the early shock propagation experiments by Sakharov. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Howard, WM (reprint author), Lawrence Livermore Natl Lab, POB 5508, Livermore, CA 94551 USA. NR 3 TC 0 Z9 0 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 319 EP 322 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600072 ER PT S AU Ionita, A Mas, EM Clements, BE AF Ionita, Axinte Mas, Eric M. Clements, Bradford E. BE Furnish, MD Elert, M Russell, TP White, CT TI Two-scale FEM in the dynamic response of a heterogeneous material SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE finite element; two-scale; heterogeneous; localization AB It is common in the numerical simulation of the dynamic response of a heterogeneous material to use the average material properties, which usually are obtained through a homogenization technique. This approach would lead to an average response of the composite. However, if ones interested in the local response of the material then a localization technique needs to be used. This paper addresses the localization problem in the dynamic response of such material, using a two-scale FEM approach. The basic equations for coupling, between the first (or coarse) scale to the second (or fine scale) are presented. Numerical examples are included. C1 LANL, Div Theoret, Los Alamos, NM 87545 USA. RP Ionita, A (reprint author), LANL, Div Theoret, MS B221, Los Alamos, NM 87545 USA. OI Clements, Brad/0000-0002-9664-637X NR 6 TC 0 Z9 0 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 323 EP 326 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600073 ER PT S AU Lomov, I Liu, B AF Lomov, Ilya Liu, Benjamin BE Furnish, MD Elert, M Russell, TP White, CT TI Approximation of multifluid mixture response for simulation of sharp and diffuse material interfaces on an Eulerian grid SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE multimaterial; material interfaces; multiphase; mixture models AB Multimaterial Eulerian and Arbitrary Lagragian-Euleiian (ALE) codes usually use volume fractions of materials to track individual components in mixed cells. Material advection usually is calculated either by interface capturing, where a high-order van Leer-like slope reconstruction technique is applied, or interface tracking, where a normal reconstruction technique is applied. The former approach is more appropriate for gas-like substances, and the latter is ideal for solids and liquids, since it does not smear out material interfaces. A wide range of problems involves both diffuse and sharp interfaces between substances and demands a combination of these techniques. It is possible to treat all substances that can diffuse into each other as a single material and only keep mass fractions of the individual components of the mixture. The material response can be determined based on the assumption of pressure and temperature equilibrium between components of the mixture. Unfortunately, it is extremely difficult to solve the corresponding system of equations. In order to avoid these problems one can introduce an effective gamma and employ the ideal gas approximation to calculate mixture response. This method provides reliable results, is able to compute strong shock waves, and deals with complex equations of state. Results from a number of simulations using this scheme are presented. C1 Lawrence Livermore Natl Lab, Energy & Environm Directorate, Livermore, CA 94550 USA. RP Lomov, I (reprint author), Lawrence Livermore Natl Lab, Energy & Environm Directorate, Livermore, CA 94550 USA. NR 3 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 335 EP 338 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600076 ER PT S AU Plohr, BJ Plohr, JN AF Plohr, Bradley J. Plohr, JeeYeon N. BE Furnish, MD Elert, M Russell, TP White, CT TI Simplified shock conditions for large-strain thermo-visco-plasticity SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE shock waves; jump conditions; plastic flow ID FORMULATION AB We consider shock loading of a thermo-visco-plastic material; the strain is not restricted to be small. We show how to reduce the Rankine-Hugoniotjump conditions to a simplified form analogous to that used in fluid dynamics. Just as for fluids, the shock conditions can be separated into purely thermodynamic conditions (the Rayleigh and Hugoniot equations), a condition determining the velocity, and a condition determining the strain, which can be solved sequentially to determine the shock wave. C1 LANL, Los Alamos, NM 87545 USA. RP Plohr, BJ (reprint author), LANL, T-13,MS B213, Los Alamos, NM 87545 USA. NR 3 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 343 EP 346 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600078 ER PT S AU Cherne, FJ Kadau, K Germann, TC AF Cherne, Frank J. Kadau, Kai Germann, Timothy C. BE Furnish, MD Elert, M Russell, TP White, CT TI A molecular dynamics study of solid gallium using a modified embedded atom model SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE gallium; phase transitions; molecular dynamics ID SHOCK-WAVES; SIMULATIONS; GA AB Gallium is a complex material that has only recently been modeled by molecular dynamics simulations, using the literature modified embedded atom method potential [Baskes et al., PRB 66, 104107 (2002)]. This potential captures some of the unique characteristics of this intriguing metal. Here we report on the shock-induced solid-solid structural transformation, and its dependence upon the crystallographic loading direction. In order to characterize the nature of the transition we have performed both non-equilibrium and equilibrium molecular dynamics simulations. These simulations provide insight into the nature of the solid-solid and solid-liquid phase transitions in addition to the kinetic behavior of this complex material. The Hugoniot for solid gallium will be presented. This research is being done in collaboration with an experimental ultrafast X-ray diffraction effort here at Los Alamos National Laboratory. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Cherne, FJ (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. OI Germann, Timothy/0000-0002-6813-238X; Cherne, Frank/0000-0002-8589-6058 NR 14 TC 0 Z9 0 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 383 EP 386 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600087 ER PT S AU Hammerberg, JE Ravelo, R Germann, TC AF Hammerberg, J. E. Ravelo, R. Germann, T. C. BE Furnish, MD Elert, M Russell, TP White, CT TI High density sliding at Ta/Al and Al/Al interfaces SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE molecular dynamics; friction; high velocity; Ta; Al AB We present 3D-nonequilibrium molecular dynamics results for the velocity dependence of the frictional force at smooth sliding interfaces for Ta and Al single crystals. For Ta/Al we consider Al(100)/Ta(100) and Al(111)/Ta(110) interfaces sliding along [001] and [1 (1) over bar0](fcc)/[001](fcc) respectively. These are compared with Al(111)/Al(100) interfaces at the same loads, corresponding to a pressure of 15 GPa. Both interfacial pairs show similar behavior in the velocity dependence of the frictional force: a low velocity regime with an increasing frictional force followed by a strain induced transformation regime at velocities above approximately 1/10 the transverse sound speed, followed by a fluidized interface at high velocities. For both interfacial pairs, the high velocity dependence of the frictional force exhibits power law behavior, F-t proportional to v(-beta) with beta=3/4. We discuss the structural changes that influence dissipation in each of these regimes. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hammerberg, JE (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. OI Germann, Timothy/0000-0002-6813-238X NR 5 TC 0 Z9 0 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 391 EP 394 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600089 ER PT S AU Moriarty, JA Benedict, LX Glosli, JN Hood, RQ Orlikowski, DA Patel, MV Soderlind, P Streitz, FH Tang, M Yang, LH AF Moriarty, J. A. Benedict, L. X. Glosli, J. N. Hood, R. Q. Orlikowski, D. A. Patel, M. V. Soederlind, P. Streitz, F. H. Tang, M. Yang, L. H. BE Furnish, MD Elert, M Russell, TP White, CT TI Quantum-based atomistic simulation of transition metals SO SHOCK COMPRESSION OF CONDENSED MATTER - 2005, PTS 1 AND 2 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE atomistic simulation; MGPT potentials; tantalum; molybdenum; equation of state; strength ID GENERALIZED PSEUDOPOTENTIAL THEORY; INTERATOMIC POTENTIALS; SCREW DISLOCATIONS; SINGLE-CRYSTALS; TANTALUM; PRESSURE; TA AB First-principles generalized pseudopotential theory (GPT) provides a fundamental basis for transferable multi-ion interatomic potentials in d-electron transition metals within density-functional quantum mechanics. In mid-period bcc metals, where multi-ion angular forces are important to structural properties, simplified model GPT or MGPT potentials have been developed based on canonical d bands to allow analytic forms and large-scale atomistic simulations. Robust, advanced-generation MGPT potentials have now been obtained for Ta and Mo and successfully applied to a wide range of structural, thermodynamic, defect and mechanical properties at both ambient and extreme conditions of pressure and temperature. Recent algorithm improvements have also led to a more general matrix representation of MGPT beyond canonical bands allowing increased accuracy and extension to f-electron actinide metals, an order of magnitude increase in computational speed, and the current development of temperature-dependent potentials. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Moriarty, JA (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. EM moriarty2@llnl.gov OI Patel, Mehul/0000-0002-0486-010X NR 22 TC 0 Z9 0 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 403 EP 408 PN 1&2 PG 6 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600092 ER PT S AU Valone, SM Kapila, V AF Valone, Steven M. Kapila, Vivek BE Furnish, MD Elert, M Russell, TP White, CT TI Nonequilibrium atomistic polymer simulations under shear and shock loading SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE nonequilibrium molecular dynamics; polyethylene; viscosity; shocked polymers ID EMBEDDED-ATOM POTENTIALS; HYDROCARBONS; SILICON AB The present effort is intended to provide insights into acceleration-driven instabilities in complex fluids. The vast majority of studies into Rayleigh-Taylor (steady acceleration), Richtmyer-Meshkov (impulsive acceleration or shock loading), and Kelvin-Helmholtz (shear) instabilities have been limited to simple fluids with relatively simple constitutive properties. Some fluids of interest originate from polymeric materials that will behave like complex fluids under sufficiently strong shock or shear loading. The resulting fluids possess very complicated shear-rate dependent viscous behavior. This shear-rate dependence is explored through nonequilibrium molecular dynamics simulations using shear boundary conditions applied to an atomistic model of polyethylene. The shear-rate dependence is determined over a range of rates, not just for low shear rates. The viscosity data are fit to a generalized Lorentzian and rate-theory models. C1 LANL, Los Alamos, NM 87545 USA. RP Valone, SM (reprint author), LANL, MST-8,MS-G755, Los Alamos, NM 87545 USA. NR 11 TC 3 Z9 3 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 425 EP 428 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600097 ER PT S AU Mulford, RN Swift, DC AF Mulford, Roberta N. Swift, Damian C. BE Furnish, MD Elert, M Russell, TP White, CT TI Modelling temperatures of reacting nitromethane SO SHOCK COMPRESSION OF CONDENSED MATTER - 2005, PTS 1 AND 2 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE nitromethane; EOS; quasiharmonic; homogeneous initiation; shock temperature ID SHOCK INITIATION; LIQUID NITROMETHANE; EXPLOSIVES; DETONATION; EQUATION; STATE AB An equation of state (EOS) for unreacted nitromethane, CH(3)NO(2) provides the accurate temperatures required to support a temperature dependent reaction rate within a reactive fbw model. A quasiharmonic form based on the Gr neisen equations of state was used, normalised to shock wave data but with a more rigorous treatment of thermal modes. We use reactive fbw models that include temperature as well as mechanical state to investigate shock initiation in nitromethane. Temperatures predicted by the model for various off-Hugoniot states in reactive configurations show reasonable agreement with data from experimental measurements reported by several different workers, using different diagnostic methods. A thermochemical model was used for the reaction products, and Arrhenius reaction parameters reported in the literature reproduced reported reactive behavior of nitromethane. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Mulford, RN (reprint author), Los Alamos Natl Lab, NMT 15,MS-E530, Los Alamos, NM 87545 USA. EM mulford@lanl.gov; damian.swift@physics.org NR 16 TC 2 Z9 2 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 461 EP 464 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600105 ER PT S AU Nichols, AL AF Nichols, Albert L., III BE Furnish, MD Elert, M Russell, TP White, CT TI Statistical hot spot model for explosive detonation SO SHOCK COMPRESSION OF CONDENSED MATTER - 2005, PTS 1 AND 2 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE detonation; hot spots; initiation; failure diameter; shock waves; computer model AB The Non-local Thermodynamic Equilibrium Statistical Hot Spot Model (NLTE SHS), a new model for explosive detonation, is described. In this model, the formation, ignition, propagation, and extinction of hot spots is explicitly modeled. The equation of state of the explosive mixture is treated with a non-local equilibrium thermodynamic assumption. A methodology for developing the parameters for the model is discussed, and applied to the detonation velocity diameter effect. Examination of these results indicates where future improvements to the model can be made. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Nichols, AL (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. EM nichols5@llnl.gov NR 9 TC 3 Z9 3 U1 1 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 465 EP 470 PN 1&2 PG 6 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600106 ER PT S AU Bardenhagen, SG Brydon, AD Williams, TO Collet, C AF Bardenhagen, Scott G. Brydon, Andrew D. Williams, Todd O. Collet, Christelle BE Furnish, MD Elert, M Russell, TP White, CT TI Coupling grain scale and bulk mechanical response for PBXS using numerical simulations of real microstructures SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE PBX-9501; representative volume element; microscale structure; statistical homogenization AB PBXs are complex composites geometrically (irregularly shaped grains vary greatly in size), and constitutively (grains are anisotropic, twin and fracture). Heterogeneity at the grain scale results in localized damage and the creation of hot spots. To develop accurate, quantitative and predictive models it is imperative to develop a sound physical understanding of the grain scale material response. Numerical simulation is a useful tool to further model development. Here an inherent advantage of a particle method in discretizing geometrically complex materials is exploited to import three-dimensional material configurations from x-ray microtomography data, i.e. "real" microstructures. Numerical simulations determine representative volume element size and generate statistics on grain scale strain heterogeneity. These statistics calibrate the Stochastic Transformation Field Analysis bulk constitutive model. C1 LANL, Los Alamos, NM 87545 USA. RP Bardenhagen, SG (reprint author), LANL, T-14,MS-B214, Los Alamos, NM 87545 USA. NR 8 TC 6 Z9 6 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 479 EP 482 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600109 ER PT S AU Mas, EM Clements, BE Ionita, A Peterson, P AF Mas, E. M. Clements, B. E. Ionita, A. Peterson, P. BE Furnish, MD Elert, M Russell, TP White, CT TI Finite element method calculations on statistically consistent microstructures of PBX 9501 SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE microstructure; composites; image analysis AB We have used data from image analysis to guide us in creating a finite element mesh of PBX 9501. Information about the binder concentration at different length scales taken from micrographs allows us to create a mesh that naturally incorporates inhomogeneities of the microstructure in a manner that is statistically consistent with the observed microstructure. We then apply constitutive models that are consistent with the different binder concentrations and run finite element simulations. We will present our technique for incorporating the image analysis information into the mesh, our mechanical models, and results of the simulations. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Mas, EM (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. OI Clements, Brad/0000-0002-9664-637X NR 6 TC 3 Z9 3 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 487 EP 490 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600111 ER PT S AU Vitello, P Souers, PC AF Vitello, Peter Souers, P. Clark BE Furnish, MD Elert, M Russell, TP White, CT TI The piece wise linear reactive flow rate model SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE detonation modeling; reactive flow ID DETONATION AB For non-idcal explosives a wide range of behavior is observed in experiments dealing with differing sizes and geometries. A predictive detonation model must be able to reproduce many phenomena including such effects as: variations in the detonation velocity with the radial diameter of rate sticks; slowing of the detonation velocity around gentle comers; production of dead zones for abrupt corner turning; failure of small diameter rate sticks; and failure for rate sticks with sufficiently wide cracks. Most models have been developed to explain one effect at a time. Often, changes are made in the input parameters used to fit each succeeding case with the implication that this is sufficient for the model to be valid over differing regimes. We feel that it is important to develop a model that is able to fit experiments with one set of parameters. To address this we are creating a new generation of models that are able to produce better fitting to individual data sets than prior models and to simultaneous fit distinctly different regimes of experiments. Presented here are details of our new Piece Wise Linear reactive flow model applied to LX-17. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Vitello, P (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 7 TC 2 Z9 2 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 507 EP 510 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600116 ER PT S AU Chitanvis, SM AF Chitanvis, Shirish M. BE Furnish, MD Elert, M Russell, TP White, CT TI Preliminary results from an asymptotic analysis of the forest fire model SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE burn model; asymptotic analysis; DSD; reaction zone AB Asymptotic analysis underlying Bdzil's Detonation Shock Dynamics (DSD) theory is used to obtain mesh-independent results for the Forest Fire bum model. Using the published bum rate for PBX 9501 as given by the Forest Fire model, and standard mixture rules for the products (pressure and temperature equilibrium), we obtain a D-n - kappa relation for PBX 9501. It provides a reasonable estimate for the failure diameter for PBX 9501. However, the deficit is extremely small even in the vicinity of failure i.e., (D-CJ - D-n)/D-CJ << 1, where D-CJ is the CJ detonation speed, when compared to experimental results. It is pointed out that ameliorating the Forest Fire bum rate at pressures above 100kbars leads to much improved results for the D-n - kappa curve. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Chitanvis, SM (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 11 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 511 EP 514 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600117 ER PT S AU Glaesemann, KR Fried, LE AF Glaesemann, K. R. Fried, L. E. BE Furnish, MD Elert, M Russell, TP White, CT TI Recent advances in modeling hugoniots with Cheetah SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE Cheetah; thermochemistry; equation of state; Hugoniot ID EQUATION-OF-STATE AB We describe improvements to the Cheetah thermochemical-kinetics code's equilibrium solver to enable it to find a wider range of thermodynamic states. Cheetah supports a wide range of elements, condensed detonation products, and gas phase reactions. Therefore, Cheetah can be applied to a wide range of shock problems involving both energetic and non-energetic materials. An improve equation of state is also introduced. New experimental validations of Cheetah's equation of state methodology have been performed, including both reacted and unreacted Hugoniots C1 Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94551 USA. RP Glaesemann, KR (reprint author), Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, POB 808,L-282, Livermore, CA 94551 USA. RI Glaesemann, Kurt/B-4841-2010; Fried, Laurence/L-8714-2014; OI Fried, Laurence/0000-0002-9437-7700; Glaesemann, Kurt/0000-0002-9512-1395 NR 5 TC 3 Z9 3 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 515 EP 518 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600118 ER PT S AU Hill, LG AF Hill, Larry G. BE Furnish, MD Elert, M Russell, TP White, CT TI Burning crack networks and combustion bootstrapping in cookoff explosions SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE cookoff; non-shock initiation; thermal explosion; ignition; PBX 9501; HMX ID PBX-9501 AB Burning crack networks can play an important role in cookoff explosions of the HMX-based explosive PBX 9501 [1]. Combustion within cracks can potentially spread to connected porosity, which is believed to develop in the heated explosive [2]. The burning surface area would thereby increase, causing a more violent outcome. I develop an analytic model that seeks to capture the essential physical mechanisms controlling how such a scenario runs away. The calibrated model behavior is consistent with Ref. I tests. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hill, LG (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 5 TC 1 Z9 1 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 531 EP 534 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600122 ER PT S AU Zucker, JM Barra, AJ Zerkle, DK Kaneshige, MJ Dickson, PM AF Zucker, J. M. Barra, A. J. Zerkle, D. K. Kaneshige, M. J. Dickson, P. M. BE Furnish, MD Elert, M Russell, TP White, CT TI Thermal decomposition models for high explosive compositions SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE Semtex; RDX; cook-off; decomposition kinetics AB As interest in the cook-off response of high explosives expands to include commercially available compositions, the need has arisen for a broad spectrum of predictive capabilities to describe the untoward thermal decomposition of these explosives. Empirical models for several compositions, including PETN, Semtex and Comp 13, have been developed and tested against existing experimental data. Models for Semtex I A and RDX are presented and discussed. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Zucker, JM (reprint author), Los Alamos Natl Lab, POB 1663,MS J565, Los Alamos, NM 87545 USA. NR 6 TC 1 Z9 1 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 559 EP 562 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600129 ER PT S AU Zhao, SJ Germann, TC Strachan, A AF Zhao, Shijin Germann, Timothy C. Strachan, Alejandro BE Furnish, MD Elert, M Russell, TP White, CT TI Molecular dynamics simulations of shock-induced chemical, mechanical, and thermal processes in Ni/Al nanolaminates SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE molecular dynamics; nanolaminates; Ni/Al; spontaneous alloying. ID FOILS AB We employ molecular dynamics simulations to characterize the chemical and mechanical response of nanostructured Ni/Al multilayers induced by shock loading, using a novel technique that captures both the initial shock transit as well as the subsequent longer-timescale chemical processes. Initially, the softer Al layers are shock-heated to a higher temperature than the harder Ni layers, as a result of a series of shock reflections from the impedance-mismatched interfaces. Once initiated, the highly exothermic alloying reactions can propagate in a self-sustained manner by mass and thermal diffusion. C1 Los Alamos Natl Lab, Theoret Div T14, Los Alamos, NM 87545 USA. RP Zhao, SJ (reprint author), Los Alamos Natl Lab, Theoret Div T14, Los Alamos, NM 87545 USA. OI Germann, Timothy/0000-0002-6813-238X NR 8 TC 4 Z9 4 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 593 EP 596 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600137 ER PT S AU Koller, DD Hixson, RS Gray, GT Rigg, PA Addessio, LB Cerreta, EK Maestas, JD Yablinsky, CA AF Koller, D. D. Hixson, R. S. Gray, G. T., III Rigg, P. A. Addessio, L. B. Cerreta, E. K. Maestas, J. D. Yablinsky, C. A. BE Furnish, MD Elert, M Russell, TP White, CT TI Explosively driven shock induced damage in OFHC copper SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE plastic strain; damage; Taylor wave; HE; spall ID INTERFEROMETER; SOLIDS AB OFHC Cu samples were subjected to shock loading using plane wave HE lenses to produce a uniaxial Taylor wave profile (shock followed by immediate release). Upon arrival of the shock wave at the free surface of the sample, the wave is reflected and propagates back into the sample as a release wave. It is the interaction of initial and reflected release waves that place the material in a localized state of tension which can ultimately result in damage and possibly complete failure of the material. The peak tensile stress and its location in the material are determined by the wave shape. Damage evolution processes and localized behavior are discussed based on results from time-resolved free surface velocity (VISAR) interferometry and post shock metallurgical analysis of the soft recovered samples. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Koller, DD (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. OI Yablinsky, Clarissa/0000-0001-6162-0949 NR 13 TC 5 Z9 5 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 599 EP 602 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600138 ER PT S AU Furnish, MD Reinhart, WD Trott, WM Chhabildas, LC Vogler, TJ AF Furnish, M. D. Reinhart, W. D. Trott, W. M. Chhabildas, L. C. Vogler, T. J. BE Furnish, MD Elert, M Russell, TP White, CT TI Variability in dynamic properties of tantalum: Spall, Hugoniot elastic limit and attenuation SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE tantalum; VISAR : line; line-imaging VISAR; spall; variability; Hugoniot elastic limit ID DAMAGE AB A suite of impact experiments was conducted to assess spatial and shot-to-shot variability in dynamic properties of tantalum. Samples had a uniform refined similar to 20 micron grain structure with a strong axisymmetric [111] crystallographic texture. An HEL amplitude of 2.8 GPa (corresponding to Y approximate to 1.5 GPa) was observed. Free-surface spall experiments showed clear wave attenuation and spallation phenomena. Here, loading stresses were similar to 12.5 GPa and various ratios of impactor to target thicknesses were used. Spatial and shot-to-shot variability of the spall strength was 20%, and of the HEL, 10%. Experiments conducted with smaller diameter flyer plates clearly showed edge effects in the line and point VISAR records, indicating lateral release speeds of roughly 5 km/s. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Furnish, MD (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RI Vogler, Tracy/B-4489-2009 NR 8 TC 10 Z9 10 U1 1 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 615 EP 618 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600142 ER PT S AU Henrie, BL Mason, TA Bingert, JF AF Henrie, B. L. Mason, T. A. Bingert, J. F. BE Furnish, MD Elert, M Russell, TP White, CT TI Investigating incipiently spalled tantalum through multiple section planes and serial sectioning SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE incipient spall; tantalum; serial sectioning; stereology AB Shock wave interactions within a material create a three-dimensional damage field of voids and/or strain localizations. Using a direct high explosive experiment, seven identical shots were performed to test the reproducibility of the damage fields between replicate samples. These samples, along with a sample from a plate impact experiment, were metallographically characterized to quantify the spallation void statistics. Results demonstrate that multiple section planes are required to accurately quantify the damage within a specimen. To further understand the three-dimensional nature of incipient spallation, serial sectioning was performed on a flyer plate experimental sample. Serial sectioning is yielding void and strain localization interactions not available from two-dimensional slices. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Henrie, BL (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. NR 10 TC 2 Z9 2 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 627 EP 630 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600145 ER PT S AU Mason, TA Henrie, BL Thomas, KA AF Mason, T. A. Henrie, B. L. Thomas, K. A. BE Furnish, MD Elert, M Russell, TP White, CT TI Damage progression in explosively loaded polycrystals SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE explosive drive; tantalum; oblique detonation wave; damage ID STAINLESS-STEEL; SHAPE AB One of the current challenges facing researchers in the field of dynamic properties of materials is the need for a predictive modeling capability for damage and fragmentation. A series of small-scale, explosively-driven experiments were designed and executed in order to gain a better understanding of the nucleation and growth of damage under explosive loading. The interaction of varying obliquity detonation waves with the test articles was of particular interest. The material in these tests experiences a combination of hydrostatic and deviatoric stresses that is spatially and temporally varying. Variations in shot geometries and explosive load causes direct variations in the nature of the resulting damage fields in the recovered samples. The characterization of a number of samples from a test series of tantalum discs will be presented and compared to numerical analyses of the experiments. Insights gained from the post-mortem examination of the discs and the accompanying simulations will be presented. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Mason, TA (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 8 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 638 EP 641 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600148 ER PT S AU Minich, RW Kumar, M Schwarz, A Cazamias, J AF Minich, Roger W. Kumar, Mukul Schwarz, Adam Cazamias, James BE Furnish, MD Elert, M Russell, TP White, CT TI Scaling, microstructure and dynamic fracture SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE spall; copper; plastic flow; Langevin equation; nucleation; fracture AB The relationship between pullback velocity and impact velocity is studied for difference microstructures in Cu. A size distribution of potential nucleation sites is derived under the conditions of an applied stochastic stress field. The size distribution depends on the amplitude of the stress fluctuations, which may be proportional to the flow stress thereby providing a connection between plastic flow and microvold nucleation rate. The pullback velocity in turn depends on the nucleation rate resulting in a prediction for the relationship between pullback velocity and flow stress. The theory is compared to results from Cu on Cu gas-gun experiments (10-50 GPa) with different microstructures. The scaling law relating pullback velocity and impact velocity is incorporated into a ID finite difference code and is shown to reproduce the experimental data with one adjustable parameter, the nucleation exponent, Gamma. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Minich, RW (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 7 TC 10 Z9 10 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 642 EP 645 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600149 ER PT S AU Tonks, DL Henrie, BL Trujillo, CP Holtkamp, D Thissell, WR AF Tonks, D. L. Henrie, B. L. Trujillo, C. P. Holtkamp, D. Thissell, W. R. BE Furnish, MD Elert, M Russell, TP White, CT TI Roughness of ductile damage paths in shock loaded tantalum SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE ductile damage; roughness; spallation; tantalum AB The damage in the "spall plane" of tantalum incipiently spalled in a gas gun or from HE loading consists of voids and/or regions of localized shear through which a long, continuous path can be traced. The geometry of this path has been analyzed using wavelets to show that it constitutes an affine fractal with a well defined "roughness", i.e it scales statistically with the scaling factor in the shock direction being a power of the transverse scaling factor. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Tonks, DL (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 7 TC 2 Z9 2 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 670 EP 673 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600156 ER PT S AU Wise, JL Jones, SC Hall, CA Reinhart, WD Hickman, RJ Gluth, JW AF Wise, J. L. Jones, S. C. Hall, C. A. Reinhart, W. D. Hickman, R. J. Gluth, J. W. BE Furnish, MD Elert, M Russell, TP White, CT TI Effects of annealing and preheating on the impact response of selected braze materials SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE braze; hugoniot; HEL (Hugoniot Elastic Limit); spallation; annealing; preheating AB A series of gas-gun experiments has probed the planar (uniaxial strain) impact response of six different commercial brazing alloys that were subjected to a peak shock stress in the range of 5.5 - 7.2 GPa. The alloys studied were copper + gold (65/35 wt%), copper + gold (50/50 wt%), Cusile, Nicusilg (R)*-3, Nicoro (R)* + titanium (98/2 w%), and silver zirconate. Both as-received and annealed samples of each alloy were tested under ambient (room temperature) and preheated (100 C) initial conditions. Velocity interferometer data acquired during this investigation have been evaluated to determine the dynamic yield strength (i.e., Hugoniot Elastic Limit), shock Hugoniot state, and spall strength for baseline alloy samples (i.e., unheated, as-received material) and for samples whose initial condition involved annealing and/or preheating. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Wise, JL (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 3 TC 0 Z9 0 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 686 EP 689 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600160 ER PT S AU Gray, GT Cerreta, E Yablinsky, CA Addessio, LB Henrie, BL Sencer, BH Burkett, M Maudlin, PJ Maloy, SA Trujillo, CP Lopez, MF AF Gray, G. T., III Cerreta, E. Yablinsky, C. A. Addessio, L. B. Henrie, B. L. Sencer, B. H. Burkett, M. Maudlin, P. J. Maloy, S. A. Trujillo, C. P. Lopez, M. F. BE Furnish, MD Elert, M Russell, TP White, CT TI Influence of shock prestraining and grain size on the dynamic-tensile-extrusion response of copper: Experiments and simulation SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE copper; dynamic tensile loading; shock prestraining; texture; ductility; grain size; MESA ID STRAIN-RATE; DEFORMATION AB The mechanical behavior of, and damage evolution in high-purity Cu is influenced by strain rate, temperature, stress state, grain size, and shock prestraining. The effects of grain size on the tensile mechanical response of high-purity Cu have been probed and are correlated with the evolution of the substructure. The dynamic extrusion response of shock prestrained Cu demonstrates the significant influence of grain size on the large-strain dynamic tensile ductility of high-purity copper. Eulerian hydrocode simulations utilizing the Mechanical Threshold Stress constitutive model were performed to provide insight into the dynamic extrusion process. Quantitative comparisons between the predicted and measured deformation topologies and extrusion rates are presented. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Gray, GT (reprint author), Los Alamos Natl Lab, MST 8, Los Alamos, NM 87545 USA. RI Maloy, Stuart/A-8672-2009; OI Maloy, Stuart/0000-0001-8037-1319; Yablinsky, Clarissa/0000-0001-6162-0949 NR 13 TC 15 Z9 15 U1 1 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 725 EP 728 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600169 ER PT S AU Hayes, DB Gray, GT Hall, CA Hixson, RS AF Hayes, D. B. Gray, G. T., III Hall, C. A. Hixson, R. S. BE Furnish, MD Elert, M Russell, TP White, CT TI Elastic-plastic behavior of U6Nb under ramp wave loading SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE U6Nb; shock; compression wave; twinning; shear stress relaxation ID COMPRESSION; GPA AB When uranium-niobium (6 wt%) alloy is shock loaded, the expected elastic precursor is absent. A prior model attributed this absence to shear-induced twinning and the concomitant shear stress reduction that prevented the shocked material from reaching the plastic yield point. In the present study, carefully prepared U6Nb was subjected to shock loading to verify the adequacy of the prior model. Other samples were loaded with a ramp pressure pulse with strain rate large enough so that significant twinning would not occur during the experiment. Backward integration analyses of these latter experiments' back surface motion give stress-strain loading paths in U6Nb that suggest ordinary elastic-plastic flow. Some of the U6Nb was pre-strained by cold rolling in an effort to further ensure that twinning did not affect wave propagation. Shock and ramp loadings yielded similar results to the baseline material except, as expected, they are consistent with a higher yield stress and twinning shear stress threshold. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hayes, DB (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 7 TC 0 Z9 0 U1 0 U2 7 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 729 EP 732 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600170 ER PT S AU Remington, BA Hawreliak, J Lorenz, KT Lorenzana, HE McNaney, JM Pollaine, SM Swift, DC Yaakobi, B AF Remington, B. A. Hawreliak, J. Lorenz, K. T. Lorenzana, H. E. McNaney, J. M. Pollaine, S. M. Swift, D. C. Yaakobi, B. BE Furnish, MD Elert, M Russell, TP White, CT TI Materials response under extreme conditions SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE high pressure strength; constitutive models; Rayleigh-Taylor instability; laser experiments; dynamic diffraction; dynamic EXAFS; phase transformation ID DUCTILE-BRITTLE TRANSITION; ALPHA-IRON; CONSTITUTIVE RELATIONS; TAYLOR INSTABILITY; TIME SCALES; STRAIN-RATE; DISLOCATION; COMPRESSION; PRESSURE; STRESS AB Solid state experiments at extreme pressures (0.1 - 1 Mbar) and strain rates (10(6) - 10(8) s(-1)) are being developed on high-energy laser facilities. The goal is a capability to test constitutive models for high-pressure, solid-state strength of materials. Relevant constitutive models are discussed, and our progress in developing a ramped-pressure, shockless drive is given. Designs to test the constitutive models with experiments measuring perturbation growth due to the Rayleigh-Taylor instability in solid-state samples are presented. Results from dynamic diffraction and EXAFS lattice diagnostics are given, showing that compression, phase, and temperature can be inferred on sub-nsec time scales. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Remington, BA (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI McNaney, James/F-5258-2013 NR 26 TC 1 Z9 1 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 765 EP 770 PN 1&2 PG 6 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600179 ER PT S AU Xue, Q Cerreta, EK Gray, GT AF Xue, Qing Cerreta, Ellen K. Gray, George T., III BE Furnish, MD Elert, M Russell, TP White, CT TI Influence of explosive-driven shock prestraining on the microstructural evolution and shear localization of 304 and 316L stainless steels SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE adiabatic shear bands; shock prestraining; stainless steel AB Initiation and development of adiabatic shear bands in explosively pre-shocked 304 and 316L stainless steels was investigated to quantify the influence of shock prestraining on the onset of shear localization. Forced shear tests on hat-shaped specimens were conducted using a compressive split-Hopkinson pressure bar. The shear localized behavior under the forced shear condition in these preshocked materials was examined. Shear-band initiation was found to be very sensitive to the preshocked microstructures, especially to the strong interactions among defects such as deformation twin networks. The microstructures of shear bands were characterized using transmission electron microscopy(TEM). Dynamic and quasi-static recovery was verified to be a dominant mechanism in the formation of the ultra fine substructures within the shear bands generated in these preshocked steels. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Xue, Q (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, MST-8,MS G755, Los Alamos, NM 87545 USA. NR 9 TC 6 Z9 6 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 783 EP 786 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600183 ER PT S AU Anderson, MU Cox, DE Montgomery, ST Setchell, RE AF Anderson, M. U. Cox, D. E. Montgomery, S. T. Setchell, R. E. BE Furnish, MD Elert, M Russell, TP White, CT TI Compositional effects on the shock compression and release properties of alumina-filled epoxy SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE composites; alumina-filled epoxy; encapsulants AB Alumina-filled epoxy is used for encapsulation in explosively driven pulsed power devices. Its shock compression and release properties have a strong influence on device performance. Previous studies using a material containing 43% by volume alumina showed a complex behavior characterized by extended wave profiles and high release-wave velocities. In recent studies, these properties have been examined while changing the total alumina volume fraction, the alumina particle size and morphology, and the epoxy constituents. Reducing the alumina volume fraction in steps from 43% to 0% had anticipated effects on Hugoniot states, compressive wave profiles and velocities, and release-wave velocities, although release velocities changed more rapidly. Only minor effects were observed when the alumina volume fraction was held constant while varying alumina particle characteristics or the host epoxy. Thin-pulse experiments showed combined compression and release effects resulting from decreasing the alumina volume fraction. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Anderson, MU (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 3 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 789 EP 792 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600184 ER PT S AU Sheffield, SA Dattelbaum, DM Alcon, RR Robbins, DL Stahl, DB Gustavsen, RL AF Sheffield, S. A. Dattelbaum, D. M. Alcon, R. R. Robbins, D. L. Stahl, D. B. Gustavsen, R. L. BE Furnish, MD Elert, M Russell, TP White, CT TI Shock-induced chemical reaction in organic and silicon based liquids SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE shock-induced chemistry; ethynyltrimethylsilane; tert-butylacetylene; liquid; magnetic gauges AB Shock-induced chemical reactions remain an area in shock physics that needs further investigation, particularly for determining the influence of pressure, temperature, and chemical structure on reactivity. Several studies have been done in the past that indicate dimerization, polymerization, and decomposition take place indifferent shock-produced pressure and temperature regimes depending on chemical functionality. We present results obtained from single-shock experiments in which liquids were studied using embedded multiple magnetic gauges to make in-situ measurements of the particle velocity profiles at up to ten Lagrangian positions in the liquid. One of the liquids was organic (tert-butylacetylene) and the other was a closely related silicon-based material (ethynyltrimethylsilane). Multiple wave structures were measured in each liquid when the input pressure was above a certain threshold. Here, the reactivity of these materials are compared. C1 LANL, Los Alamos, NM 87545 USA. RP Sheffield, SA (reprint author), LANL, DX-2,MS-P952, Los Alamos, NM 87545 USA. OI Gustavsen, Richard/0000-0002-2281-2742 NR 6 TC 5 Z9 5 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 921 EP 924 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600216 ER PT S AU Asay, BW Tasker, DG King, JC Sanders, VE Son, SF AF Asay, B. W. Tasker, D. G. King, J. C. Sanders, V. E. Son, S. F. BE Furnish, MD Elert, M Russell, TP White, CT TI Electrical conductivity measurements in reacting metastable intermolecular composites SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE Metastable Intermolecular Composites; conductivity; reaction zone; nanoenergetics AB Metastable Intermolecular Composite (MIC) materials are comprised of a mixture of oxidizer and fuel with particle sizes in the nanometer range. To better understand the reaction mechanisms of burning MIC materials, dynamic electrical conductivity measurements have been performed on a MIC material for the first time. Simultaneous optical measurements of the wave front position have shown that the reaction and conduction fronts are coincident within 160 gm. Unlike detonating high explosives (HE) where the conductivity profile is represented by an initial peak followed by an exponential decay of conductivity, the MIC conductivity profile is a gradual, irregular ramp which increases from zero over many microseconds. This suggests that the reaction zone thickness is different in MICs compared to detonating HE. Static measurements of conductivity of pressed MIC pellets suggest that the conduction is associated with chemical reaction in the MIC. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Asay, BW (reprint author), Los Alamos Natl Lab, Box 1663, Los Alamos, NM 87545 USA. OI Son, Steven/0000-0001-7498-2922 NR 5 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 927 EP 930 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600217 ER PT S AU Aslam, TD AF Aslam, Tariq D. BE Furnish, MD Elert, M Russell, TP White, CT TI Direct numerical simulation of detonation SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE detonation; numerical simulation AB The last decade has been witness to a thousand fold gain in computational power [1], in addition to comparable gains from improved computational algorithms such as adaptive mesh algorithms (AMR) [2] [3]. But, even with these gains, there are many detonation phenomena which are beyond the current and foreseeable capabilities of direct simulation of resolved reaction zones. There are many other issues that arise in the simulation of detonation which lead to ill-posed computations. Many of these issues, as wen as an overview of accomplishments in the field, current state of the art, and future work on detonation simulation will be discussed. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Aslam, TD (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. OI Aslam, Tariq/0000-0002-4263-0401 NR 13 TC 3 Z9 3 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 931 EP 935 PN 1&2 PG 5 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600218 ER PT S AU Ferm, EN Mariam, F AF Ferm, Eric N. Mariam, Fesseha CA LANSCE Proton Radiography Team BE Furnish, MD Elert, M Russell, TP White, CT TI Proton radiography observations of the failure of a detonation wave to propagate to the end of a conical explosive charge SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE explosive behavior; diameter effect curve; failure diameter AB Failure diameter is a well-known property of explosive materials, being the critical diameter below which a steady detonation wave will not be able to support itself and ultimately fails to propagate. A detonation wave traveling down a uniform cylindrical charge larger than its critical diameter will reach a steady detonation velocity which is a function of the diameter of the explosive as well as other material properties, notably density and temperature. In this work, we use proton radiography to study the propagation of detonations down conical PBX 9502 charges beginning at diameters larger than failure diameter and ending at diameters much smaller than failure diameter. Experiments show cases where complete detonation of the cone occurs as well as cases where failure is observed significantly before the end of the cone and significant portions of the charge remain unreacted. Wave velocities and densities are obtained from the multiple image proton radiography experiments and compared with failure diameter effect curves for PBX 9502. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Ferm, EN (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 5 TC 1 Z9 1 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 968 EP 971 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600227 ER PT S AU Menikoff, R AF Menikoff, Ralph BE Furnish, MD Elert, M Russell, TP White, CT TI Detonation wave profile in PBX 9501 SO SHOCK COMPRESSION OF CONDENSED MATTER - 2005, PTS 1 AND 2 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE PBX 9501; reaction zone profile; CJ detonation wave; ZND model AB Measurements of a CJ-detonation wave in PBX 9501 with a VISAR technique have shown a classical ZND profile for the reaction zone. This is compatible with one-dimensional simulations using realistic equations of state and an Arrhenius reaction rate fit to available data from other experiments. Moreover, the reaction zone width is less than the average grain size in the PBX. In contrast to initiation, which requires hot spots, the reaction rate from the bulk shock temperature is sufficiently high for propagating a detonation wave. This raises questions with bum models used for both ignition and propagation of detonation waves. C1 Los Alamos Natl Lab, Theoret Div, Los Alamos, NM 87545 USA. RP Menikoff, R (reprint author), Los Alamos Natl Lab, Theoret Div, MS-B214, Los Alamos, NM 87545 USA. EM rtm@lanl.gov NR 20 TC 2 Z9 2 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 986 EP 989 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600231 ER PT S AU Pahl, RJ Trott, WM Snedigar, S Castaneda, JN AF Pahl, R. J. Trott, W. M. Snedigar, S. Castaneda, J. N. BE Furnish, MD Elert, M Russell, TP White, CT TI Evaluation of aluminum participation in the development of reactive waves in shock compressed HMX SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE Shock Initiation; aluminum; reactive wave AB A series of gas gun tests has been performed to examine contributions to energy release from micron-sized and nanometric aluminum powder added to sieved (212-300 mu m) HMX. In the absence of added metal, 4-mm-thick, low-density (64-68% of theoretical maximum density) pressings of the sieved HMX respond to modest shock loading by developing distinctive reactive waves that exhibit both temporal and mesoscale spatial fluctuations. Parallel tests have been performed on samples containing 10% (by mass) aluminum in two particle sizes: 2-mu m and 123-nm mean particle diameter, respectively. The finely dispersed aluminum initially suppresses wave growth from HMX reactions; however, after a visible induction period, the added metal drives rapid increases in the transmitted wave particle velocity. Wave profile variations as a function of the aluminum particle diameter are discussed. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Pahl, RJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 5 TC 0 Z9 0 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 990 EP 993 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600232 ER PT S AU Son, SF Berghout, HL AF Son, S. F. Berghout, H. L. BE Furnish, MD Elert, M Russell, TP White, CT TI Flame spread across surfaces of PBX 9501 SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE PBX 9501; explosives; combustion; flame spread ID HMX AB We report the results of flame-spread experiments of PBX 9501 (HMX-based explosive). The horizontal flame spread rate, V, for PBX 9501 is curve-fit with a power law function of pressure from 0.077 to 17.3 MPa, specifically, S-f = 0.259 P-0.528(cm/s) where P is the dimensionless pressure p/p(0) with p(0) = 0.1 MPa. V-f is of the same order of magnitude as normal deflagration and varies nearly as the square root of pressure, as scaling estimates predict. In the vertical orientation, the flame propagation downward was observed to be slightly faster than horizontal flame spread presumably because of the melt layer flowing downward on the sample. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Son, SF (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. OI Son, Steven/0000-0001-7498-2922 NR 20 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1014 EP 1017 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600238 ER PT S AU Tappan, BC Son, SF Moore, DS AF Tappan, B. C. Son, S. F. Moore, D. S. BE Furnish, MD Elert, M Russell, TP White, CT TI Nano-aluminum reaction with nitrogen in the burn front of oxygen-free energetic materials SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE high-nitrogen; explosives; nano-aluminum; decomposition AB Nano-particulate aluminum metal was added to the high nitrogen energetic material triaminoguanidium azotetrazolate (TAGzT) in order to determine the effects on decomposition behavior. Standard safety testing (sensitivity to impact, spark and friction) are reported and show that the addition of nano-Al actually decreases the sensitivity of the pure TAGzT. Thermo-equilibrium calculations (Cheetah) indicate that the all of the Al reacts to form AIN in TAGzT decomposition, and the calculated specific impulses are reported. T-Jump/FTIR spectroscopy was performed on the neat TAGzT. Emission spectra were collected to determine the temperature of AIN formation in combustion. Burning rates were also collected, and the effects of nano-Al on rates are discussed. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Tappan, BC (reprint author), Los Alamos Natl Lab, POB 1663,MS C920, Los Alamos, NM 87545 USA. OI Son, Steven/0000-0001-7498-2922 NR 8 TC 0 Z9 0 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1022 EP 1025 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600240 ER PT S AU Tarver, CM AF Tarver, Craig M. BE Furnish, MD Elert, M Russell, TP White, CT TI Detonation reaction zones in condensed explosives SO SHOCK COMPRESSION OF CONDENSED MATTER - 2005, PTS 1 AND 2 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE explosives; detonation; reaction zone ID CHEMICAL ENERGY-RELEASE; WAVES AB Experimental measurements using nanosecond time resolved embedded gauges and laser interferometric techniques, combined with Non-Equilibrium Zeldovich - von Neumann - Doring (NEZND) theory and Ignition and Growth reactive flow hydrodynamic modeling, have revealed the average pressure/particle velocity states attained in reaction zones of self-sustaining detonation waves in several solid and liquid explosives. The time durations of these reaction zone processes are discussed for explosives based on pentaerythritol tetranitrate (PETN), nitromethane, octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (EA4x), triaminitrinitrobenzene(TATB) and trinitrotoluene (TNT). C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Tarver, CM (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. EM tarver1@llnl.gov NR 35 TC 8 Z9 8 U1 0 U2 10 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1026 EP 1029 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600241 ER PT S AU Browning, RV Peterson, PD Roemer, EL Oldenborg, MR Thompson, DG Deluca, R AF Browning, Richard V. Peterson, Paul D. Roemer, Edward L. Oldenborg, Michael R. Thompson, Darla G. Deluca, Racci BE Furnish, MD Elert, M Russell, TP White, CT TI Experimental study of grit particle enhancement in non-shock ignition SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE PBX 9501; Bruceton drop weight impact machine; Type 12; Type 12b; grit; sandpaper ID EXPLOSIVES AB The drop weight impact test is the most commonly used configuration for evaluating sensitivity of explosives to non-shock ignition. Although developed 60 years ago and widely used both as a material compression test and as a test bed for understanding the ignition process itself, little is known about the flow mechanisms or involvement of grit particles as sensitizing agents. In this paper, we present the results of a series of experiments designed to study the flow mechanisms and events leading up to ignition. The experimental configuration used involves two pellet sizes, 3 and 5 mm in diameter, tested with three conditions: (1) smooth steel anvils, (2) standard flint sandpaper, and (3) shed grit particles loaded between the steel anvils and the pellet faces. Diagnostics include optical micrographs, and scanning electron micrographs. Un-reacted samples show a variety of morphologies, including what appear to be quenched reaction sites, even at very low drop heights. Quasi-static crushing experiments were also done to quantify load-time histories. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Browning, RV (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 6 TC 0 Z9 0 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1041 EP 1044 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600244 ER PT S AU Chidester, SK Vandersall, KS Switzer, LL Tarver, CM AF Chidester, Steven K. Vandersall, Kevin S. Switzer, Lori L. Tarver, Craig M. BE Furnish, MD Elert, M Russell, TP White, CT TI LX-04 violence measurements - Steven Tests impacted by projectiles shot from a howitzer gun SO SHOCK COMPRESSION OF CONDENSED MATTER - 2005, PTS 1 AND 2 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE Steven Impact Test; explosive safety; LX-04; HMX explosives; ignition threshold ID EXPLOSIVES; IGNITION AB Characterization of the reaction violence of LX-04 explosive (85% HMX and 15% Viton A by weight) was obtained from Steven Impact Tests performed above the reaction initiation threshold. A 155 mm Howitzer propellant driven gas gun was used to accelerate the Steven Test projectiles in the range of approximately 170-300 m/s to react (ignite) the LX-04 explosive. Blast overpressure gauges, acoustic microphones, and high-speed photography characterized the level of high explosive reaction violence. A detonation in this velocity range was not observed and when comparing these results (and the Susan test results) with that of other HMX based explosives, LX-04 has a more gradual reaction violence slope as the impact velocity increases. The high binder content (15%) of the LX-04 explosive is believed to be the key factor to the lower level of violence. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Chidester, SK (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM chidester1@llnl.gov; vandersalll@llnl.gov; tarver1@llnl.gov NR 12 TC 0 Z9 2 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1049 EP 1052 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600246 ER PT S AU Dickson, PM Parker, GR Smilowitz, LB Zucker, JM Asay, BW AF Dickson, P. M. Parker, G. R. Smilowitz, L. B. Zucker, J. M. Asay, B. W. BE Furnish, MD Elert, M Russell, TP White, CT TI Frictional heating and ignition of energetic materials SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE friction; frictional heating; hot spots; HMX; PBX 9501 AB For many years, powder friction tests have been an integral part of explosives sensitivity and safety testing. More recently, oblique impact tests have been used in the hazard assessment of monolithic charges. However, these tests are simply threshold tests for reaction, and relatively little work has been done to try to examine the processes that lead to frictional heating and ignition of energetic materials. We report the results from a series of experiments in which energetic materials are subjected to frictional heating under closely-controlled conditions (normal load, sliding speed, grit quantity and composition, substrate). The response of the energetic material and grit, if present, is observed by optical and infrared high-speed photography to determine the nature of the interactions between the test material, grit and substrate, and the mechanisms by which the energetic material may be heated to ignition. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Dickson, PM (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 4 TC 5 Z9 5 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1057 EP 1060 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600248 ER PT S AU Garcia, F Vandersall, KS Forbes, JW Tarver, CM Greenwood, D AF Garcia, Frank Vandersall, Kevin S. Forbes, Jerry W. Tarver, Craig M. Greenwood, Daniel BE Furnish, MD Elert, M Russell, TP White, CT TI Thermal cook-off experiments of the HMX based high explosive LX-04 to characterize violence with varying confinement SO SHOCK COMPRESSION OF CONDENSED MATTER - 2005, PTS 1 AND 2 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE thermal explosion; cook-off; LX-04; HMX explosives; violence; confinement AB Thermal cook-off experiments were carried out using LX-04 explosive (85% HMX and 15% Viton by weight) with different levels of confinement to characterize the effect of confinement on the reaction violence. These experiments involved heating a porous LX-04 sample in a stainless steel container with varying container end plate thickness and assembly bolt diameter to control overall confinement. As expected, detonation did not occur and reducing the overall confinement lowered the reaction violence. This is consistent with modeling results that predict that a lower confinement will act to lower the cook-off pressure and thus the overall burn rate which lowers the overall violence. These results suggest that controlling the overall system confinement can modify the relative safety in a given scenario. C1 Lawrence Livermore Natl Lab, Energet Mat Ctr, Livermore, CA 94550 USA. RP Garcia, F (reprint author), Lawrence Livermore Natl Lab, Energet Mat Ctr, Livermore, CA 94550 USA. EM vandersalll@llnl.gov; jforaps@comcast.net; tarver1@llnl.gov NR 4 TC 3 Z9 3 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1061 EP 1064 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600249 ER PT S AU Henson, BF Smilowitz, L Romero, J Asay, BW Dickson, PM AF Henson, B. F. Smilowitz, L. Romero, J. Asay, B. W. Dickson, P. M. BE Furnish, MD Elert, M Russell, TP White, CT TI Measurement of temperature and ignition time during fast compression and flow in PBX 9501 SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE non-shock initiation; decomposition kinetics; PBX 9501 ID THERMAL-DECOMPOSITION; EXPLOSIVES; HMX AB We have made radiometric temperature measurements on a microsecond time scale during the compression and flow of PBX 9501 subsequent to impact. A cylindrical sample was fired into a sapphire window normal to the cylinder axis at velocities on the order of several hundred meters per second. Cylindrically symmetric flow resulted which led to the classic circular ignition pattern at the outermost radial distance from the center at times of a few to tens of microseconds and temperatures on the order of 1000 degrees Celsius. We a] so observed a difference in ignition pattern for samples of beta or delta PBX 9501. We report the times and temperatures of ignition and relate them to our model of PBX 9501 decomposition kinetics. We also discuss these results in the context of various other methods of thermally and mechanically heating PBX 9501 and note the invariance of the decomposition kinetics of HMX to the method of heating. C1 Los Alamos Natl Lab, Chem & Dynam Expt Div, Los Alamos, NM 87545 USA. RP Henson, BF (reprint author), Los Alamos Natl Lab, Chem & Dynam Expt Div, Los Alamos, NM 87545 USA. NR 15 TC 2 Z9 2 U1 2 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1077 EP 1080 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600253 ER PT S AU Libersky, LD Randles, PW AF Libersky, L. D. Randles, P. W. BE Furnish, MD Elert, M Russell, TP White, CT TI Shocks and discontinuities in particle methods SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE SPH; DPD; particle; meshfree; simulation; continuum; code; hydrodynamics; shocks ID HYDRODYNAMICS AB We briefly examine the propagation of strong shocks across density discontinuities as computed with two meshfree particle codes: Smoothed Particle Hydrodynamics and Dual Particle Dynamics. Density ratios considered are typical of those that appear in explosive-metal interactions. The work is motivated by the desire to eliminate numerical artifacts from degrading solutions of problems involving explosive initiation and spall. We observe that incorporating aspects of the Riemann solution into the SPH pair-wise interpolation scheme improves the results significantly. DPD results arc superior. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Libersky, LD (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 5 TC 1 Z9 1 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1089 EP 1092 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600256 ER PT S AU Martin, ES Thomas, KA Clarke, SA Kennedy, JE Stewart, DS AF Martin, Eric S. Thomas, Keith A. Clarke, Steven A. Kennedy, James E. Stewart, D. Scott BE Furnish, MD Elert, M Russell, TP White, CT TI Measurements of the DDT process in exploding bridgewire detonators SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE DDT; PETN; exploding bridgewire; detonation; initiation ID DEFLAGRATION-TO-DETONATION AB The deflagration-to-detonation transition (DDT) of low density (0.88 g/cc) PETN during exploding bridgewire (EBW) initiation has been studied using laser interferometry and streak photography. Cutback experiments using VISAR have confirmed a 1.0 nun run-distance to detonation in this low density PETN powder. In a detonation system using a combination of low and high density powders, an apparent center of initiation (COI) analysis of streak data has yielded a surprisingly similar result. This data suggested that a compaction of low density powder to near theoretical maximum density (TMD) may occur before the onset of detonation, which is consistent with work done previously [2-4]. These experiments show this is not the case and COI analysis reveals a non-ideal initial propagation front. Additionally, data show that although function time increases significantly with decreasing firing voltage, the apparent COI changes very little. This indicates that the detonation criterion is not dependent upon the rate of deflagration, but on a volume of material that must be burned in a confined space to create the critical pressure needed at the compaction front. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Martin, ES (reprint author), Los Alamos Natl Lab, DX-1, Los Alamos, NM 87545 USA. NR 8 TC 0 Z9 0 U1 2 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1093 EP 1096 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600257 ER PT S AU Parker, GR Dickson, PM Asay, BW Smilowitz, LB Henson, BF Perry, WL AF Parker, G. R. Dickson, P. M. Asay, B. W. Smilowitz, L. B. Henson, B. F. Perry, W. L. BE Furnish, MD Elert, M Russell, TP White, CT TI Understanding the mechanisms leading to gas permeation in thermally damaged PBX 9501 SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE thermal damage; explosives; permeability; cook-off AB We present data that indicate that thermally damaged PBX 9501 is substantially more permeable than the pristine material and that this may have a significant effect on the pre-ignition slow cook-off process, as well as the post-ignition flame spread process. Experiments indicate that the mechanism responsible for the formation of interconnected matrix porosity is likely dominated by nitroplasticizer decomposition in the early stages of the permeability evolution followed by secondary, slower HMX decomposition. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Parker, GR (reprint author), Los Alamos Natl Lab, POB 1663,MS C920, Los Alamos, NM 87545 USA. OI Perry, William/0000-0003-1993-122X NR 12 TC 2 Z9 2 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1101 EP 1104 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600259 ER PT S AU Schmitt, RG AF Schmitt, R. G. BE Furnish, MD Elert, M Russell, TP White, CT TI Toward a new paradigm for reactive flow modeling SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE shock initiation; SDT; reactive flow; CTH; multiphase; Baer-Nunziato AB Traditional reactive flow modeling provides a computational representation of shock initiation of energetic materials. Most reactive flow models require ad hoc assumptions to obtain robust simulations, assumptions that result from partitioning energy and volume change between constituents in a reactive mixture. For example, most models assume pressure and/or temperature equilibrium for the mixture. Many mechanical insults to energetic materials violate these approximations. Careful analysis is required to ensure that the model assumptions and limitations are not exceeded. One limitation is that the shock to detonation transition is replicated only for strong planar shocks. Many models require different parameters to match data from thin pulse, ramp wave, or multidimensional loading, an approach that fails for complex loading. To accurately simulate reaction under non-planar shock impact scenarios a new formalism is required. The continuum mixture theory developed by Baer and Nunziato is used to eliminate ad hoc assumptions and limitations of current reactive flow models. This modeling paradigm represents the multiphase nature of reacting condensed/gas mixtures. Comparisons between simulations and data are presented. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Schmitt, RG (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 10 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1109 EP 1112 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600261 ER PT S AU Vandersall, KS Tarver, CM Garcia, F Urtiew, PA AF Vandersall, Kevin S. Tarver, Craig M. Garcia, Frank Urtiew, Paul A. BE Furnish, MD Elert, M Russell, TP White, CT TI Shock initiation experiments on PBX9501 explosive at 150(circle)c for ignition and growth modeling SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE explosive; PBX9501; shock to detonation transition; ignition and growth AB Shock initiation experiments on the explosive PBX9501 (95% HMX, 2.5% estane, and 2.5% nitroplasticizer by weight) were performed at 150 degrees C to obtain in-situ pressure gauge data and Ignition and Growth modeling parameters. A 101 mm diameter propellant driven gas gun was utilized to initiate the PBX9501 explosive with manganin piezoresistive pressure gauge packages placed between sample slices. The run-distance-to-detonation points on the Pop-plot for these experiments showed agreement with previously published data and Ignition and Growth modeling parameters were obtained with a good fit to the experimental data. This parameter set will allow accurate code predictions to be calculated for safety scenarios involving PBX9501 explosives at temperatures close to 150 degrees C. C1 Energet Mat Ctr, Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Vandersall, KS (reprint author), Energet Mat Ctr, Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 11 TC 4 Z9 4 U1 1 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1127 EP 1130 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600265 ER PT S AU Cerreta, E Gray, GT Lawson, AC Morris, CE Hixson, RS Rigg, PA AF Cerreta, E. Gray, G. T., III Lawson, A. C. Morris, C. E. Hixson, R. S. Rigg, P. A. BE Furnish, MD Elert, M Russell, TP White, CT TI The influence of interstitial oxygen on the alpha to omega phase transition in titanium and zirconium SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE shock wave; metastable phases; solid-solid phase transformation; impurity concentration ID TRANSFORMATION AB The pressure for the alpha to omega phase transition was investigated for two grades of titanium and three grades of zirconium. A series of shock experiments were conducted from 5 to 35GPa and revealed that the pressure for the phase transition increases with increasing interstitial oxygen content and is completely suppressed in low purity materials. For the high purity Ti and Zr in this study, the pressure for the phase transition occurred at 10.4 and 7.1GPa, respectively and no reverse transformation was observed upon unloading. Increasing the oxygen content increases the number of octahedral sites occupied; this is postulated to increase the pressure for the phase transition. Neutron diffraction was utilized to quantify the volume fraction of metastable omega phase and to characterize the microstructures within the high purity, shocked, and "soft' recovered specimens. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Cerreta, E (reprint author), Los Alamos Natl Lab, MST-8, Los Alamos, NM 87545 USA. NR 14 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1149 EP 1152 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600270 ER PT S AU Sander, R Blais, N Engelke, R Dattelbaum, D Sheffield, S McInroy, R AF Sander, Robert Blais, Norm Engelke, Ray Dattelbaum, Dana Sheffield, Steve McInroy, Rhonda BE Furnish, MD Elert, M Russell, TP White, CT TI Shock-induced chemistry in polydimethylsiloxane SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE polydimethylsiloxane; decomposition; shock; mass spectrometer AB Polydimethylsiloxane (PDMS) is a common silicone polymer. Understanding its decomposition product distribution is required for calculating its equation of state under shock conditions. We have detonated small samples of HMX explosive in contact with the polymer in a high vacuum chamber and used a time-of-flight mass spectrometer to analyze the chemical products of PDMS decomposition. We have used the computer code CTH to model the time history of pressure and temperature in the sample. The time scale of a few nanoseconds in these experiments generates products that are significantly different than the equilibrium products observed in thermal pyrolysis experiments. The mass spectrum under shock conditions predominately shows monomers to heptamers of dimethylsiloxane, and the n-mers minus methyl groups. We have compared spectra of high molecular weight liquid PDMS, crosslinked solid PDMS, and silica filled solid PDMS. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Sander, R (reprint author), Los Alamos Natl Lab, MS-J567, Los Alamos, NM 87545 USA. NR 5 TC 1 Z9 1 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1165 EP 1168 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600274 ER PT S AU Smilowitz, L Henson, BF Sandstrom, MM Asay, BW Oschwald, DM Romero, JJ Novak, AM AF Smilowitz, L. Henson, B. F. Sandstrom, M. M. Asay, B. W. Oschwald, D. M. Romero, J. J. Novak, A. M. BE Furnish, MD Elert, M Russell, TP White, CT TI Fast internal temperature measurements in pbx9501 thermal explosions SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE thermal explosion; PBX 9501; optical pyrometry; laser ignition AB We have made spatially and temporally resolved temperature measurements internal to a thermal explosion in PBX9501, which is a plastic bonded explosive composed of 95% HMX and 2.5% estane mixed with 2.5% nitroplasticizer (BDNPA/F). In order to study the evolution of ignition in a thermally treated piece of explosive, we have pushed the time resolution of several different temperature diagnostics. In this paper, we will discuss the details of the time response of these diagnostics including temperature uncertainties. The temperature measurements are made both by thermocouples with corrections applied to compensate for the thermocouple response time and with optical pyrometry. An additional goal of adding high energy radiography diagnostics to future experiments has motivated an effort to synchronize thermal explosions to an external clock. In this paper, I discuss our current capabilities for controlling and measuring the development of an ignition within apiece of heated PBX9501. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Smilowitz, L (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 7 TC 7 Z9 8 U1 1 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1211 EP 1214 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600285 ER PT S AU Salyer, TR Khalsa, NS Hill, LG AF Salyer, T. R. Khalsa, N. S. Hill, L. G. BE Furnish, MD Elert, M Russell, TP White, CT TI An automated test bed for visar probe characterization SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE VISAR; probe; characterization AB Accurate characterization of VISAR probes is helpful for their effective fielding on a given experiment. Much stands to be gained through optimal placement and choice of probe as well as optimal target surface preparation. Revelations through a series of dynamic shots can be time consuming, expensive, and inefficient. An automated system to measure probe illumination and return characteristics independent of the VISAR helps to alleviate these problems. Motion of a target reflector is simulated via linear traverses and a rotation stage. Laser illumination is provided to yield a probe response measured with sensitive optical power detectors. A beam profiler is used for 2-D analysis of the illumination spot over the full range of target travel. Furthermore, the whole system is automated through LabVIEW software control. A proposed standardized probe test consists of the 1-D axial response, sensitivity to target angle, sensitivity to target surface material and preparation technique, and the illumination beam characteristics. As the community recognizes the need for more specialized probes, such a tool enables the rapid development of new designs as well as the cataloging of current ones. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Salyer, TR (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 4 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1219 EP 1222 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600287 ER PT S AU Vogan, WS Anderson, WW Grover, M King, NSP Lamoreaux, SK Morley, KB Rigg, PA Stevens, GD Turley, WD Buttler, WT AF Vogan, W. S. Anderson, W. W. Grover, M. King, N. S. P. Lamoreaux, S. K. Morley, K. B. Rigg, P. A. Stevens, G. D. Turley, W. D. Buttler, W. T. BE Furnish, MD Elert, M Russell, TP White, CT TI A new spin on an old technology: Piezoelectric ejecta diagnostics for shock environments SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE shock physics; piezoelectric diagnostics; ejecta ID SURFACES AB In our investigation of ejecta, or metal particulate emitted from a surface subjected to shock-loaded conditions, we have developed a shock experiment suitable for testing new ideas in piezoelectric mass and impact detectors. High-explosive (HE) shock loading of tin targets subjected to various machined and compressed finishes results in significant trends in ejecta characteristics of interest such as areal density and velocity Our enhanced piezoelectric diagnostic, "piezo-pins" modified for shock mitigation, have proven levels of robustness and reliability suitable for effective operation in these ejecta milieux. These field tests address questions about ejecta production from surfaces of interest; experimental results are discussed and compared with those from complementary diagnostics such as x-ray and optical attenuation visualization techniques. C1 LANL, Los Alamos, NM 87545 USA. RP Vogan, WS (reprint author), LANL, DX-3,MS-P940, Los Alamos, NM 87545 USA. NR 9 TC 0 Z9 1 U1 2 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1223 EP 1226 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600288 ER PT S AU Alexander, CS Vogler, TJ Reinhart, WD Grady, DE Kipp, ME Chhabildas, LC AF Alexander, C. S. Vogler, T. J. Reinhart, W. D. Grady, D. E. Kipp, M. E. Chhabildas, L. C. BE Furnish, MD Elert, M Russell, TP White, CT TI Influence of shock wave measurement technique on the determination of hugoniot states SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE shock waves; VISAR; inclined mirror; silicon carbide; WONDY ID COMPRESSION AB In theory, a shock wave traveling through a material gives rise to a well defined Hugoniot state. However, in practice, the measurement technique used to probe the shocked state imparts on the data a unique set of experimental artifacts which can affect interpretation of this data. Two commonly used methods for acquiring shock wave data, VISAR and inclined-mirror measurements are examined to determine the effects of the measurement technique on the final Hugoniot determination. Recent plate impact experiments on the ceramic silicon carbide are used to calibrate a one-dimensional computer model, which is then used to simulate experimental VISAR and inclined mirror data. The results, which highlight potential pitfalls in interpretation of experimental data, will be discussed and solutions to the discrepancies will be proposed. Further, this work is extended to include ceramics that undergo phase transitions. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Alexander, CS (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RI Vogler, Tracy/B-4489-2009 NR 10 TC 1 Z9 1 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1229 EP 1232 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600289 ER PT S AU Mang, JT Hjelm, RP AF Mang, Joseph. T. Hjelm, Rex. P. BE Furnish, MD Elert, M Russell, TP White, CT TI Sans and contrast variation measurement of the different contributions to the total surface area in PBX 9501 as a function of pressing intensity SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE PBX 9501; pressing parameters; microstructure AB We have used small-angle neutron scattering (SANS) in conjunction with the method of contrast variation to measure the surface area (S-HB, S-HV, and S-BV) associated with the three interfaces (HMX-binder (HB), HMX-voids (HV) and binder-voids (BV)) in pressed pellets of PBX 9501 (95% HMX and 5% binder, by weight). These interfaces are of interest as they may influence the transmission of microstresses and hot spot formation under shock conditions. Because of the difficulty in making measurements, little is known about the inicrostructure of pressed PBX 9501 parts and thus how it is affected by processing. Here, we explore the effect of varying the pressing intensity on the PBX 9501 microstructure and in particular, how the three interfaces (HB, HV and BV) are affected. Disk-shaped samples of PBX 9501 were die-pressed with applied pressures ranging between 5,000 and 29,000 psi. SANS measurements were performed on 4-5 pellets at each pressure. Analysis of the SANS data indicates systematic changes in S-HB, S-HV, and S-BV with applied pressure. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Mang, JT (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Lujan Center, LANL/G-4896-2012 NR 4 TC 2 Z9 2 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1271 EP 1274 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600299 ER PT S AU Rigg, PA Anderson, WW Olson, RT Buttler, WT Hixson, RS AF Rigg, P. A. Anderson, W. W. Olson, R. T. Buttler, W. T. Hixson, R. S. BE Furnish, MD Elert, M Russell, TP White, CT TI Investigation of ejecta production in tin using plate impact experiments SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE tin; ejecta; plate impact AB Experiments to investigate ejecta production in shocked tin have been performed using plate impact facilities at Los Alamos National Laboratory. Three primary diagnostics - piezoelectric pins, Asay foils, and low energy X-ray radiography - were fielded simultaneously in an attempt to quantify the amount of ejecta produced in tin as the shock wave breaks out of the free surface. Results will be presented comparing and contrasting all three diagnostics methods. Advantages and disadvantages of each method will be discussed. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Rigg, PA (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 4 TC 1 Z9 1 U1 2 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1283 EP 1286 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600302 ER PT S AU Swift, DC Ruiz, CR AF Swift, Damian C. Ruiz, Christian R. BE Furnish, MD Elert, M Russell, TP White, CT TI Laser-induced Mach waves for ultra-high-pressure experiments SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE shock; high energy density physics; Mach wave; laser ablation AB Laser-driven experiments area principal technique for inducing pressures in the terapascal regime and higher. However, when high irradiance laser light interacts with matter, it generates fast electrons and x-rays, which may heat material ahead of hydrodynamic loading waves such as shocks. This preheat limits the scope for investigating properties of initially cold material and potentially reduces the accuracy of measurements. A new configuration for laser experiments is proposed, using convergence and irregular reflection of shocks to induce high pressures without such high laser irradiances. Related Mach wave generators have been developed previously for high-explosive drive; the design considerations for laser-driven Mach wave generators are typically dictated by constraints on the laser pulse duration and differ from high-explosive systems. Relations are presented between the pressures achievable with different variants of the laser drive technique and different combinations of materials in the Mach-interaction region. The prospects for isentropic compression using this type of experiment are discussed. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Swift, DC (reprint author), Los Alamos Natl Lab, P-24,MS-E526, Los Alamos, NM 87545 USA. NR 6 TC 1 Z9 1 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1297 EP 1300 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600305 ER PT S AU Anderson, WW AF Anderson, William W. BE Furnish, MD Elert, M Russell, TP White, CT TI Jump conditions for nonsteady waves SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE nonsteady waves AB The usual integral forms of the Rankine-Hugoniot jump conditions are valid only for steady waves that conserve flux. However, many waves encountered in practice are not steady. Here, more general forms of the jump conditions are presented. These can be used, with certain assumptions, for waves that do not conserve flux. The insights gained from these more general forms provide guidance for practical analysis of measured wave profiles. Using simple approximations, analytic expressions can be obtained that allow the evaluation of the validity of assumptions about use of the Rankine-Hugoniot equations for analysis. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Anderson, WW (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 3 TC 2 Z9 2 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1303 EP 1306 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600306 ER PT S AU Baer, MR Hall, CA Gustavsen, RL Hooks, DE Sheffield, SA AF Baer, M. R. Hall, C. A. Gustavsen, R. L. Hooks, D. E. Sheffield, S. A. BE Furnish, MD Elert, M Russell, TP White, CT TI Isentropic compression experiments for mesoscale studies of energetic composites SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE isentropic compression; Z accelerator; explosives; CTH modeling AB New experimental diagnostics and computational modeling provide an unprecedented means for improving the understanding of energetic material behavior at the mesoscale (grain or crystal ensemble levels). This study focuses on the determination of appropriate constitutive and EOS property data of the constituents of an energetic composite at high stress and moderate strain-rate states. The Sandia Z accelerator is used to determine the mechanical response of energetic composites via isentropic ramp wave compression loading. In this paper we describe an energy source method in CTH that models ramp loading for the analysis of ICE experiments. This approach is applied to design experimental configurations to probe the constituent response of PBX 9501 subjected to similar to 40 Kbar ramp load over 300 ns duration. Multiple VISAR are used to determine the averaged response of the composite material in comparison to the individual constituents including the effects of anisotropy of HMX crystals and the interactions of fine crystallites with binder material. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Baer, MR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. OI Gustavsen, Richard/0000-0002-2281-2742 NR 9 TC 1 Z9 2 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1307 EP 1310 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600307 ER PT S AU Hall, CA Baer, MR Gustavsen, RL Hooks, AE Orler, EB Dattelbaum, DM Sheffield, SA Sutherland, GT AF Hall, C. A. Baer, M. R. Gustavsen, R. L. Hooks, D. E. Orler, E. Bruce Dattelbaum, D. M. Sheffield, S. A. Sutherland, G. T. BE Furnish, MD Elert, M Russell, TP White, CT TI A study of polymer materials subjected to isentropic compression loading SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE isentropic compression; Z accelerator; polymer binders; CTH modeling AB This work applies a ramped, quasi-isentropic; compression loading technique (ICE) to investigate the mechanical behavior of polymers that are often used in energetic composites. The focus of this effort is the determination of appropriate constitutive and EOS property data at high stress states and moderate strain rates that is needed for detailed mesoscale modeling. Several thicknesses of samples were subjected to a ramp load of similar to 45 Kbar over 500 ns duration using the Sandia Z-machine. Profiles of transmitted ramp waves were measured at window interfaces using conventional VISAR. Shock physics analysis is then used to determine the nonlinear material response of the binder materials. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Hall, CA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. OI Gustavsen, Richard/0000-0002-2281-2742 NR 8 TC 1 Z9 2 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1311 EP 1314 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600308 ER PT S AU Hare, DE Vandersall, KS Garcia, F Davis, JP Hall, C Forbes, JW AF Hare, David E. Vandersall, Kevin S. Garcia, Frank Davis, Jean-Paul Hall, Clint Forbes, Jerry W. BE Furnish, MD Elert, M Russell, TP White, CT TI Isentropic compression data on LX-04 explosive at 150 degrees C using the Z accelerator SO SHOCK COMPRESSION OF CONDENSED MATTER - 2005, PTS 1 AND 2 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE ramp compression; Z machine; HMX based explosive; LX-04; equations of state AB Isentropic compression data was collected on LX-04 explosive (85% HMX and 15% Viton by weight) at 150 degrees C using the Sandia National Laboratories Z accelerator facility. A ramp compression wave was applied to the explosive samples mounted on aluminum panels with VISAR interferometry measuring the sample and backing window interface velocity. Heating was obtained by wrapping band heaters around a thermal mass attached to each panel and temperatures were recorded by thermocouples at several locations on the panel. This work will outline the methods used, discuss the VISAR interface velocities, and present the preliminary data obtained on heated LX-04. These results demonstrate the ability to perform experiments on preheated samples to obtain isentrope data. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Hare, DE (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM vandersalll@llnl.gov; jpdavis@sandia.gov; chall@sandia.gov; jforaps@comcast.net NR 10 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1315 EP 1318 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600309 ER PT S AU Tasker, DG Goforth, JH Oona, H Rigg, PA Dennis-Koller, D King, J Torres, D Herrera, A Sena, F Abeyta, F Tabaka, L AF Tasker, D. G. Goforth, J. H. Oona, H. Rigg, P. A. Dennis-Koller, D. King, J. Torres, D. Herrera, D. Sena, F. Abeyta, F. Tabaka, L. BE Furnish, MD Elert, M Russell, TP White, CT TI Results from isentropic compression experiments (ICE) SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE isentropic compression; equation of state; copper AB We have developed high explosive pulsed power (HEPP) methods to obtain accurate isentropic EOS data with the isentropic compression experiment (ICE)[1][2]. In the HEPP-ICE experiment, fast rising current pulses (with risetimes from 400 to 600 ns) at current densities of many MA/cm, create continuous magnetic compression of materials to Mbar pressures. The response of materials to this isentropic loading, as determined with VISAR measurements of free surfaces, provides the required isentropic EOS. Experiments on copper will be presented here. The data are analyzed using conventional Lagrangian and Backward [3] techniques. In the present arrangement four samples can be studied at one time, but accurate EOS data can only be obtained from opposing sample pairs, because it is only these pairs that share the same magnetic fields. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Tasker, DG (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 12 TC 0 Z9 0 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1323 EP 1326 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600311 ER PT S AU Reed, EJ Soljacic, M Gee, R Joannopoulos, JA AF Reed, Evan J. Soljacic, Marin Gee, Richard Joannopoulos, J. A. BE Furnish, MD Elert, M Russell, TP White, CT TI Prediction of coherent optical radiation from shock waves in polarizable crystals SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE shock wave; optical emission; molecular dynamics; sodium chloride ID X-RAY-DIFFRACTION; SINGLE-CRYSTALS AB We predict that coherent electromagnetic radiation in the 1-100 THz frequency range can be generated in crystalline materials when subject to a shock wave or soliton-like propagating excitation. To our knowledge, this phenomenon represents a fundamentally new form of coherent optical radiation source that is distinct from lasers and free-electron lasers. General analytical theory and molecular dynamics simulations demonstrate coherence lengths on the order of mm. (around 20 THz) and potentially greater. The emission frequencies are determined by the shock speed and the lattice constants of the crystal and can potentially be used to determine atomic-scale properties of the shocked material. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Reed, EJ (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 10 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1345 EP 1348 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600316 ER PT S AU Lawrence, RJ Reinhart, WA Chhabildas, LC Thornhill, TF AF Lawrence, R. J. Reinhart, W. D. Chhabildas, L. C. Thornhill, T. F. BE Furnish, MD Elert, M Russell, TP White, CT TI Hypervelocity impact flash at 6, 11, and 25 KM/S SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE impact flash; hypervelocity; spectroscopy; visible; infrared AB Impact-flash phenomenology has been known for decades, and is now being considered for missile-defense applications, in particular for remote engagement diagnostics. To technically establish this capability, we have conducted a series of experiments at impact velocities of similar to 6, similar to 11, and similar to 25 km/s. Two- and three-stage light-gas guns were used for the lower two velocities, and magnetically-driven flyers on the Sandia Z machine achieved the higher velocity. Spectrally- and temporally-resolved flash output addressed data reproducibility, material identification, and target configuration analysis. Usable data were obtained at visible and infrared wavelengths. Standard atomic spectral databases were used to identify strong lines from all principal materials used in the study. The data were unique to the individual materials over the wide range of velocities and conditions examined. The time-varying nature of the signals offered the potential for correlation of the measurements with various aspects of the target configuration. Integrating the records over wavelength helped to clarify those time variations. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Lawrence, RJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 4 TC 2 Z9 2 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1349 EP 1352 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600317 ER PT S AU Briggs, M Ferm, EN AF Briggs, Matt Ferm, Eric N. BE Furnish, MD Elert, M Russell, TP White, CT TI Axial visar velocity measurements of the non-planar acceleration of a plate from a penetrating shaped charge jet SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE velocimetry; VISAR; shaped charge; jet AB A Viper explosive shaped charge jet creates a stretching rod of metal, with its tip traveling 9.2mm/mu s and slower portions traveling < 3 mm/mu s. As this rod impacts and penetrates an obstructing steel plate, a highly non-planar flow evolves. We have recorded the free-surface velocity at the point of exit of the jet, which will ultimately be accelerated to the residual velocity of the jet. The thick target we have chosen allows the penetration to reach a quasi-steady subsonic penetration rate, before the wave structure begins to exit the plate. The resulting acceleration at the free surface is a continuous VISAR record with no required discontinuous fringe jumps. An elastic wave accelerates the free surface first, followed by a decaying shock wave, and plastic wave. Ultimately the release waves reach the penetrating jet and the surface begins to accelerate to velocities near the speed of the jet exiting the plate. We compare the present experimental and model calculations with the published results. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Briggs, M (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 3 TC 0 Z9 0 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1371 EP 1374 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600322 ER PT S AU Rae, PJ Brown, EN AF Rae, Philip J. Brown, Eric N. BE Furnish, MD Elert, M Russell, TP White, CT TI The Taylor impact and large strain response of poly(ether-etherketone) (PEEK) SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE PEEK; large strains; Taylor impact AB Taylor impacts experiments were conducted on PEEK at velocities between 150 & 360 m s(-1).The material was found to respond in a ductile manner and exhibit a color change later found to be associated with large compressive strains in PEEK, irrespective of strain-rate. No changes in molecular weight were detected as a result of high-strain rate or large strain deformation. Melting has been shown not to be responsible for the ductile deformation and limited tearing response of PEEK subject to Taylor impact. C1 LANL, Los Alamos, NM 87545 USA. RP Rae, PJ (reprint author), LANL, MS G755,POB 1663, Los Alamos, NM 87545 USA. OI Brown, Eric/0000-0002-6812-7820 NR 8 TC 1 Z9 1 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1399 EP 1402 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600329 ER PT S AU Colvin, JD Kalantar, DH AF Colvin, Jeffrey D. Kalantar, Daniel H. BE Furnish, MD Elert, M Russell, TP White, CT TI Scaling of pressure with intensity in laser-driven shocks and effects of hot x-ray preheat SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE iron; high-pressure solid-state phase transformations; x-ray preheat; shock waves in solids; laser-target interactions AB To drive shocks into solids with a laser we either illuminate the material directly, or to get higher pressures, illuminate a plastic ablator that overlays the material of interest. In both cases the illumination intensity is low, << 10(13) W/cm(2), Compared to that for traditional laser fusion targets. In this regime, the laser beam creates and interacts with a collisional, rather than a collisionless, plasma. We present scaling relationships for shock pressure with intensity derived from simulations for this low-intensity collisional plasma regime. In addition, sometimes the plastic-ablator targets have a thin flash-coating of Al on the plastic surface as a shine-through barrier, this Al layer can be a source of hot x-ray preheat. We discuss how the preheat affects the shock pressure, with application to simulating VISAR measurements from experiments conducted on various lasers on shock compression of Fe. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Colvin, JD (reprint author), Lawrence Livermore Natl Lab, L-356,POB 808, Livermore, CA 94551 USA. NR 6 TC 1 Z9 1 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1413 EP 1416 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600332 ER PT S AU Tierney, TE Swift, DC Luo, SN Niemczura, J Gammel, JT Peralta, P AF Tierney, T. E. Swift, D. C. Luo, S-N. Niemczura, J. Gammel, J. T. Peralta, P. BE Furnish, MD Elert, M Russell, TP White, CT TI Quasi-isentropic and shock compression measurements of iron response by direct laser illumination SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE iron; equation of state; strength; shock; isentropic compression; laser loading AB We performed a series of dynamic loading experiments on iron with pressures of 5-40 GPa at the Trident Laser Laboratory. We used 2.4 ns laser pulses of varying shapes and irradiances of 2 to 1000 GW/cm(2) to load a 5-mm diameter region of rolled iron foils that were 25-50 microns thick. The temporal characteristic of the laser irradiance was tailored to produce shock or quasi-isentropic loading histories. Line-imaging VISAR was used to time-resolve free surface velocities. In several experiments, two different thickness samples, placed side-by-side, were subjected to the same irradiance history. We describe the experiment configuration, analysis, and results. C1 Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87544 USA. RP Tierney, TE (reprint author), Los Alamos Natl Lab, Div Phys, POB 1663, Los Alamos, NM 87544 USA. NR 9 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1425 EP 1428 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600335 ER PT S AU Crawford, DA AF Crawford, D. A. BE Furnish, MD Elert, M Russell, TP White, CT TI Using mesoscale modeling to investigate the role of material heterogeneity in geologic and planetary materials SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE heterogeneity; complex crater; yield strength; gabbroic anorthosite; CTH AB The propagation of shock waves through target materials is strongly influenced by the presence of small-scale structure, fractures, physical and chemical heterogeneities. Reverberations behind the shock from the presence of physical heterogeneity have been proposed as a mechanism for transient weakening of target materials [1] as are localized shock effects seen in some meteorites [2]. Pre-existing fractures can also affect melt generation [3]. Recent mesoscale studies in computational hydrodynamics have attempted to bridge the gap in numerical modeling between the microscale and the continuum,. Methods are being devised using shock physics hydrocodes such as CTH [4] and Monte-Carlo-type methods to investigate the shock properties of heterogeneous materials [5] and to compare the results with experiments [6]. Recent numerical experiments at the mesoscale using these statistical methods suggest that heterogeneity at the micro-scale plays a substantial and statistically quantifiable role in the effective shear and fracture strength of rocks. This paper will describe the methodology we are using to determine the strength of heterogeneous geologic and planetary materials. C1 Sandia Natl Labs, Thermal & React Proc Dept 1516, Albuquerque, NM 87185 USA. RP Crawford, DA (reprint author), Sandia Natl Labs, Thermal & React Proc Dept 1516, POB 5800,MS 0836, Albuquerque, NM 87185 USA. NR 8 TC 1 Z9 1 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1453 EP 1457 PN 1&2 PG 5 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600341 ER PT S AU Liu, BT Lomov, I Glenn, LA AF Liu, Benjamin T. Lomov, Ilya Glenn, Lewis A. BE Furnish, MD Elert, M Russell, TP White, CT TI Numerical modeling of mixing and venting from explosions in underground chambers SO Shock Compression of Condensed Matter - 2005, Pts 1 and 2 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference of the American-Physical-Society-Topical-Group-on-Shock-Compression-of-Condense d-Matter CY JUL 31-AUG 05, 2005 CL Baltimore, MD SP Amer Phys Soc, Top Grp Shock Compress Condensed Matter DE shock loading; turbulent mixing AB 2D and 3D numerical simulations were performed to study the dynamic interaction of explosion products in an underground concrete chamber with ambient air, barrels of water, and the surrounding walls and structure. The simulations were carried out with GEODYN, a multi-material, Godunov-based Eulerian code that employs adaptive mesh refinement and rum efficiently on massively parallel computer platforms. Tabular equations of state were used to model materials under shock loading. An appropriate constitutive model was used to describe the concrete. Interfaces between materials were either tracked with a volume-of-fluid method that used high-order reconstruction to specify the interface location and orientation, or a capturing approach was employed with the assumption of local thermal and mechanical equilibrium. A major focus of the study was to estimate the extent of water heating that could be obtained prior to venting of the chamber. Parameters investigated included the chamber layout. energy density in the chamber and the yield-to-water mass ratio. Turbulent mixing was found to be the dominant heat transfer mechanism for heating the water. C1 Lawrence Livermore Natl Lab, Energy & Environm Directorate, Livermore, CA 94550 USA. RP Liu, BT (reprint author), Lawrence Livermore Natl Lab, Energy & Environm Directorate, 7000 East Ave, Livermore, CA 94550 USA. NR 2 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 0-7354-0341-4 J9 AIP CONF PROC PY 2006 VL 845 BP 1472 EP 1475 PN 1&2 PG 4 WC Physics, Multidisciplinary; Physics, Condensed Matter SC Physics GA BEX71 UT WOS:000240034600345 ER PT J AU Chitnis, N Cushing, JM Hyman, JM AF Chitnis, Nakul Cushing, J. M. Hyman, J. M. TI Bifurcation analysis of a mathematical model for malaria transmission SO SIAM JOURNAL ON APPLIED MATHEMATICS LA English DT Article DE malaria; epidemic model; reproductive number; bifurcation theory; endemic equilibria; disease-free equilibria ID HETEROGENEOUS POPULATIONS; BACKWARD BIFURCATION; ENDEMIC MALARIA; IMMUNITY; DISEASES; SPREAD; VECTOR AB We present an ordinary differential equation mathematical model for the spread of malaria in human and mosquito populations. Susceptible humans can be infected when they are bitten by an infectious mosquito. They then progress through the exposed, infectious, and recovered classes, before reentering the susceptible class. Susceptible mosquitoes can become infected when they bite infectious or recovered humans, and once infected they move through the exposed and infectious classes. Both species follow a logistic population model, with humans having immigration and disease- induced death. We de. ne a reproductive number, R(0), for the number of secondary cases that one infected individual will cause through the duration of the infectious period. We find that the disease- free equilibrium is locally asymptotically stable when R(0) < 1 and unstable when R(0) > 1. We prove the existence of at least one endemic equilibrium point for all R(0) > 1. In the absence of disease- induced death, we prove that the transcritical bifurcation at R(0) = 1 is supercritical (forward). Numerical simulations show that for larger values of the disease- induced death rate, a subcritical (backward) bifurcation is possible at R(0) = 1. C1 Swiss Trop Inst, Dept Epidemiol & Publ Hlth, CH-4002 Basel, Switzerland. Univ Arizona, Dept Math, Tucson, AZ 85721 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Chitnis, N (reprint author), Swiss Trop Inst, Dept Epidemiol & Publ Hlth, Socinstr 57, CH-4002 Basel, Switzerland. EM Nakul.Chitnis@unibas.ch; cushing@math.arizona.edu; hyman@lanl.gov RI Chitnis, Nakul/B-3105-2013; OI Chitnis, Nakul/0000-0002-1103-9141 NR 28 TC 112 Z9 118 U1 2 U2 18 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1399 J9 SIAM J APPL MATH JI SIAM J. Appl. Math. PY 2006 VL 67 IS 1 BP 24 EP 45 DI 10.1137/050638941 PG 22 WC Mathematics, Applied SC Mathematics GA 123EO UT WOS:000243279300002 ER PT J AU Srinivasan, A AF Srinivasan, Aravind TI Extension of the Lovasz local lemma, and its applications to integer programming SO SIAM JOURNAL ON COMPUTING LA English DT Article DE Lovasz local lemma; column-sparse integer programs; approximation algorithms; randomized rounding; discrepancy ID INDEPENDENT SET PROBLEM; PARALLEL ALGORITHMS; ORDERED SETS; PACKING AB The Lovasz local lemma due to Erdos and Lovasz (Infinite and Finite Sets, Colloq. Math. Soc. J. Bolyai 11, 1975, pp. 609 - 627) is a powerful tool in proving the existence of rare events. We present an extension of this lemma, which works well when the event to be shown to exist is a conjunction of individual events, each of which asserts that a random variable does not deviate much from its mean. As applications, we consider two classes of NP-hard integer programs: minimax and covering integer programs. A key technique, randomized rounding of linear relaxations, was developed by Raghavan and Thompson ( Combinatorica, 7 ( 1987), pp. 365 - 374) to derive good approximation algorithms for such problems. We use our extension of the local lemma to prove that randomized rounding produces, with nonzero probability, much better feasible solutions than known before, if the constraint matrices of these integer programs are column-sparse ( e. g., routing using short paths, problems on hypergraphs with small dimension/degree). This complements certain well-known results from discrepancy theory. We also generalize the method of pessimistic estimators due to Raghavan ( J. Comput. System Sci., 37 ( 1988), pp. 130 - 143), to obtain constructive ( algorithmic) versions of our results for covering integer programs. C1 Univ Maryland, Dept Comp Sci, College Pk, MD 20742 USA. Univ Maryland, Inst Adv Comp Studies, College Pk, MD 20742 USA. Natl Univ Singapore, Singapore 117548, Singapore. DIMACS, Piscataway, NJ USA. Inst Adv Study, Princeton, NJ 08540 USA. Max Planck Inst Informat, D-66123 Saarbrucken, Germany. Sandia Natl Labs, Livermore, CA 94550 USA. RP Srinivasan, A (reprint author), Univ Maryland, Dept Comp Sci, College Pk, MD 20742 USA. EM srin@cs.umd.edu NR 36 TC 9 Z9 9 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0097-5397 EI 1095-7111 J9 SIAM J COMPUT JI SIAM J. Comput. PY 2006 VL 36 IS 3 BP 609 EP 634 DI 10.1137/S0097539703434620 PG 26 WC Computer Science, Theory & Methods; Mathematics, Applied SC Computer Science; Mathematics GA 123ES UT WOS:000243279700003 ER PT J AU Djidjev, HN AF Djidjev, Hristo N. TI A linear-time algorithm for finding a maximal planar subgraph SO SIAM JOURNAL ON DISCRETE MATHEMATICS LA English DT Article DE planar graphs; planarity testing; incremental algorithms; graph planarization; data structures; triconnectivity AB We construct an optimal linear-time algorithm for the maximal planar subgraph problem: given a graph G, find a planar subgraph G' of G such that adding to G' an extra edge of G results in a nonplanar graph. Our solution is based on a fast data structure for incremental planarity testing of triconnected graphs and a dynamic graph search procedure. Our algorithm can be transformed into a new optimal planarity testing algorithm. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Djidjev, HN (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM djidjev@lanl.gov NR 25 TC 5 Z9 5 U1 0 U2 3 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0895-4801 EI 1095-7146 J9 SIAM J DISCRETE MATH JI SIAM Discret. Math. PY 2006 VL 20 IS 2 BP 444 EP 462 DI 10.1137/S0895480197328771 PG 19 WC Mathematics, Applied SC Mathematics GA 060YM UT WOS:000238838200012 ER PT J AU Hetmaniuk, UL Lehoucq, RB AF Hetmaniuk, U. L. Lehoucq, R. B. TI Uniform accuracy of eigenpairs from a shift-invert Lanczos method SO SIAM JOURNAL ON MATRIX ANALYSIS AND APPLICATIONS LA English DT Article; Proceedings Paper CT 5th International Workshop on Accurate Solution of Eigenvalue Problems CY JUN 29-JUL 01, 2004 CL Hagen, GERMANY DE shift-invert Lanczos decomposition; symmetric generalized eigenvalue problem; inner product ID SPECTRAL TRANSFORMATION AB This paper analyzes the accuracy of the shift-invert Lanczos iteration for computing eigenpairs of the symmetric definite generalized eigenvalue problem. We provide bounds for the accuracy of the eigenpairs produced by shift-invert Lanczos given a residual reduction. We discuss the implications of our analysis for practical shift-invert Lanczos iterations. When the generalized eigenvalue problem arises from a conforming finite element method, we also comment on the uniform accuracy of bounds (independent of the mesh size h). C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Hetmaniuk, UL (reprint author), Sandia Natl Labs, POB 5800,MS 1110, Albuquerque, NM 87185 USA. EM ulhetma@sandia.gov; rblehou@sandia.gov NR 7 TC 4 Z9 4 U1 0 U2 1 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0895-4798 J9 SIAM J MATRIX ANAL A JI SIAM J. Matrix Anal. Appl. PY 2006 VL 28 IS 4 BP 927 EP 948 DI 10.1137/050629288 PG 22 WC Mathematics, Applied SC Mathematics GA 123FB UT WOS:000243280600003 ER PT J AU Bern, M Gilbert, JR Hendrickson, B Nguyen, N Toledo, S AF Bern, M Gilbert, JR Hendrickson, B Nguyen, N Toledo, S TI Support-graph preconditioners SO SIAM JOURNAL ON MATRIX ANALYSIS AND APPLICATIONS LA English DT Article DE support preconditioners; combinatorial preconditioners; support theory; support-tree preconditioners; modified incomplete factorizations ID FACTORIZATIONS; MATRICES AB We present a preconditioning technique, called support-graph preconditioning, and use it to analyze two classes of preconditioners. The technique was first described in a talk by Pravin Vaidya, who did not formally publish his results. Vaidya used the technique to devise and analyze a class of novel preconditioners. The technique was later extended by Gremban and Miller, who used it in the development and analysis of yet another class of new preconditioners. This paper extends the technique further and uses it to analyze a class of existing preconditioners, modified incomplete Cholesky. The paper also contains a presentation of Vaidya's preconditioners, which was previously missing from the literature. C1 Xerox Corp, Palo Alto Res Ctr, Palo Alto, CA 94304 USA. Univ Calif Santa Barbara, Dept Comp Sci, Santa Barbara, CA 93106 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Raytheon Missile Syst, Tucson, AZ 85706 USA. Tel Aviv Univ, Sch Comp Sci, IL-69978 Tel Aviv, Israel. RP Xerox Corp, Palo Alto Res Ctr, 3333 Coyote Hill Rd, Palo Alto, CA 94304 USA. EM bern@parc.edu; gilbert@cs.ucsb.edu; bah@cs.sandia.gov; Nhat_X_Nguyen@raytheon.com; stoledo@tau.ac.il NR 20 TC 35 Z9 35 U1 0 U2 1 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0895-4798 EI 1095-7162 J9 SIAM J MATRIX ANAL A JI SIAM J. Matrix Anal. Appl. PY 2006 VL 27 IS 4 BP 930 EP 951 DI 10.1137/S0895479801384019 PG 22 WC Mathematics, Applied SC Mathematics GA 023BC UT WOS:000236099100002 ER PT J AU De Sterck, H Yang, UM Heys, JJ AF De Sterck, H Yang, UM Heys, JJ TI Reducing complexity in parallel algebraic multigrid preconditioners SO SIAM JOURNAL ON MATRIX ANALYSIS AND APPLICATIONS LA English DT Article DE parallel coarsening algorithms; algebraic multigrid; complexities; preconditioners AB Algebraic multigrid (AMG) is a very efficient iterative solver and preconditioner for large unstructured sparse linear systems. Traditional coarsening schemes for AMG can, however, lead to computational complexity growth as problem size increases, resulting in increased memory use and execution time, and diminished scalability. Two new parallel AMG coarsening schemes are proposed that are based solely on enforcing a maximum independent set property, resulting in sparser coarse grids. The new coarsening techniques remedy memory and execution time complexity growth for various large three-dimensional (3D) problems. If used within AMG as a preconditioner for Krylov subspace methods, the resulting iterative methods tend to converge fast. This paper discusses complexity issues that can arise in AMG, describes the new coarsening schemes, and examines the performance of the new preconditioners for various large 3D problems. C1 Univ Waterloo, Dept Appl Math, Waterloo, ON N2L 3G1, Canada. Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. Arizona State Univ, Dept Chem & Mat Engn, Tempe, AZ 85287 USA. RP De Sterck, H (reprint author), Univ Waterloo, Dept Appl Math, Waterloo, ON N2L 3G1, Canada. EM hdesterck@uwaterloo.ca; umyang@llnl.gov; heys@asu.edu NR 18 TC 50 Z9 50 U1 0 U2 1 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0895-4798 J9 SIAM J MATRIX ANAL A JI SIAM J. Matrix Anal. Appl. PY 2006 VL 27 IS 4 BP 1019 EP 1039 DI 10.1137/040615729 PG 21 WC Mathematics, Applied SC Mathematics GA 023BC UT WOS:000236099100007 ER PT J AU Vassilevski, PS Zikatanov, LT AF Vassilevski, PS Zikatanov, LT TI Multiple vector preserving interpolation mappings in algebraic multigrid SO SIAM JOURNAL ON MATRIX ANALYSIS AND APPLICATIONS LA English DT Article DE multiple vector preserving interpolation; algebraic multigrid; element agglomeration AMGe ID SMOOTHED AGGREGATION; AMGE AB We propose algorithms for the construction of AMG (algebraic multigrid) interpolation mappings such that the resulting coarse space will span (locally and globally) any number of a priori given set of vectors. Specific constructions in the case of element agglomeration AMG methods are given. Some numerical illustrations are also provided. C1 Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. Penn State Univ, Dept Math, University Pk, PA 16802 USA. RP Vassilevski, PS (reprint author), Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, POB 808,L-560, Livermore, CA 94551 USA. EM panayot@llnl.gov; ludmil@psu.edu RI Zikatanov, Ludmil/F-9365-2010 OI Zikatanov, Ludmil/0000-0002-5189-4230 NR 14 TC 7 Z9 7 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0895-4798 J9 SIAM J MATRIX ANAL A JI SIAM J. Matrix Anal. Appl. PY 2006 VL 27 IS 4 BP 1040 EP 1055 DI 10.1137/040618205 PG 16 WC Mathematics, Applied SC Mathematics GA 023BC UT WOS:000236099100008 ER PT J AU Lee, I Raghavan, P Ng, EG AF Lee, I Raghavan, P Ng, EG TI Effective preconditioning through ordering interleaved with incomplete factorization SO SIAM JOURNAL ON MATRIX ANALYSIS AND APPLICATIONS LA English DT Article DE preconditioner; incomplete factorization; ordering ID LINEAR-SYSTEMS; CONJUGATE GRADIENTS; BOTTOM-UP; SPARSE; ELIMINATION; ALGORITHM; MATRIX; EQUATIONS AB Consider an incomplete Cholesky factorization of a sparse symmetric positive definite matrix. It is common practice to start with a symmetric permutation of the rows and columns of the matrix using an ordering to reduce fill in the complete Cholesky factor. Such an approach has two drawbacks. First, such an ordering is designed to reduce fill or operation counts in the complete Cholesky factor, and thus does not necessarily address the issue of controlling fill or operation counts during incomplete factorization. Second, because the ordering is determined in advance of the incomplete factorization, it is not easy to accommodate alternative pivoting sequences, for example, using numeric measures to promote stability, while taking into account their impact on fill and operation counts. In this paper, we consider an alternative approach that interleaves ordering with numeric computation in an incomplete Cholesky factorization. Such an interleaved scheme controls fill and operation counts. It also allows the incorporation of some limited, pivot selection strategies for stability. We demonstrate through experiments that our interleaved minimum-degree approach leads to fewer failures during incomplete factorization and improved convergence when the incomplete factor is used as a preconditioner for the conjugate gradient method. We conjecture that the improvements in the quality of preconditioning arise from the ability of our method to generate better approximations to the complete factor. C1 Penn State Univ, Dept Comp Sci, University Pk, PA 16802 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Computat Res Div, Berkeley, CA 94720 USA. RP Lee, I (reprint author), Penn State Univ, Dept Comp Sci, University Pk, PA 16802 USA. EM inlee@cse.psu.edu; raghavan@cse.psu.edu; EGNg@lbl.gov NR 32 TC 7 Z9 9 U1 0 U2 1 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0895-4798 J9 SIAM J MATRIX ANAL A JI SIAM J. Matrix Anal. Appl. PY 2006 VL 27 IS 4 BP 1069 EP 1088 DI 10.1137/040618357 PG 20 WC Mathematics, Applied SC Mathematics GA 023BC UT WOS:000236099100010 ER PT J AU Bochev, PB Dohrmann, CR Gunzburger, MD AF Bochev, PB Dohrmann, CR Gunzburger, MD TI Stabilization of low-order mixed finite elements for the Stokes equations SO SIAM JOURNAL ON NUMERICAL ANALYSIS LA English DT Article DE Stokes equations; stabilized mixed methods; equal-order interpolation; inf-sup condition ID COMPUTATIONAL FLUID-DYNAMICS; ERROR ANALYSIS; VISCOUS FLOWS; FORMULATION; APPROXIMATION AB We present a new family of stabilized methods for the Stokes problem. The focus of the paper is on the lowest order velocity-pressure pairs. While not LBB compliant, their simplicity and attractive computational properties make these pairs a popular choice in engineering practice. Our stabilization approach is motivated by terms that characterize the LBB "deficiency" of the unstable spaces. The stabilized methods are defined by using these terms to modify the saddle-point Lagrangian associated with the Stokes equations. The new stabilized methods offer a number of attractive computational properties. In contrast to other stabilization procedures, they are parameter free, do not require calculation of higher order derivatives or edge-based data structures, and always lead to symmetric linear systems. Furthermore, the new methods are unconditionally stable, achieve optimal accuracy with respect to solution regularity, and have simple and straightforward implementations. We present numerical results in two and three dimensions that showcase the excellent stability and accuracy of the new methods. C1 Sandia Natl Labs, Computat Math & Algorithms Dept, Albuquerque, NM 87185 USA. Sandia Natl Labs, Struct Dynam Res Dept, Albuquerque, NM 87185 USA. Florida State Univ, Sch Computat Sci & Informat Technol, Tallahassee, FL 32306 USA. RP Bochev, PB (reprint author), Sandia Natl Labs, Computat Math & Algorithms Dept, Mail Stop 1110, Albuquerque, NM 87185 USA. EM pbboche@sandia.gov; crdohrm@sandia.gov; gunzburg@csit.fsu.edu NR 31 TC 186 Z9 212 U1 0 U2 13 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1429 J9 SIAM J NUMER ANAL JI SIAM J. Numer. Anal. PY 2006 VL 44 IS 1 BP 82 EP 101 DI 10.1137/S0036142905444482 PG 20 WC Mathematics, Applied SC Mathematics GA 023BI UT WOS:000236099800006 ER PT J AU Dohrmann, CR Lehoucq, RB AF Dohrmann, CR Lehoucq, RB TI A primal-based penalty preconditioner for elliptic saddle point systems SO SIAM JOURNAL ON NUMERICAL ANALYSIS LA English DT Article DE constrained minimization; saddle point systems; mixed finite elements; Stokes problems; block preconditioners ID OVERLAPPING SCHWARZ METHODS; MIXED APPROXIMATIONS; ENERGY MINIMIZATION; LINEAR ELASTICITY; STOKES EQUATIONS; ALGORITHM; INEXACT; TERM AB A primal-based penalty preconditioner is presented for a linear set of equations arising from elliptic saddle point problems. We show that the eigenvalues of the preconditioned matrix are positive real and demonstrate that a variant of the preconditioner can be combined with the conjugate gradient algorithm. Our approach is motivated by two basic observations. First, the solution of a problem with constraints is often similar to the solution of a problem where the constraints are penalized. Second, certain methods of solution not available for a constrained problem are possible for its penalized counterpart so motivating a primal-based Schur complement approach. Numerical examples for elliptic two- and three-dimensional problems are presented that confirm theoretical results and demonstrate the effectiveness of the preconditioner. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Dohrmann, CR (reprint author), Sandia Natl Labs, POB 5800,MS 0847, Albuquerque, NM 87185 USA. EM crdohrm@sandia.gov; rblehou@sandia.gov NR 25 TC 18 Z9 18 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1429 J9 SIAM J NUMER ANAL JI SIAM J. Numer. Anal. PY 2006 VL 44 IS 1 BP 270 EP 282 DI 10.1137/040619016 PG 13 WC Mathematics, Applied SC Mathematics GA 023BI UT WOS:000236099800015 ER PT J AU Bochev, P Gunzburger, MD AF Bochev, P Gunzburger, MD TI Least-squares finite element methods for optimality systems arising in optimization and control problems SO SIAM JOURNAL ON NUMERICAL ANALYSIS LA English DT Article DE optimal control; optimization; least-squares finite element methods; optimality systems; Lagrange multipliers ID STOKES EQUATIONS; ELLIPTIC-SYSTEMS AB The approximate solution of optimization and optimal control problems for systems governed by linear, elliptic partial differential equations is considered. Such problems are most often solved using methods based on applying the Lagrange multiplier rule to obtain an optimality system consisting of the state system, an adjoint-state system, and optimality conditions. Galerkin methods applied to this system result in indefinite matrix problems. Here, we consider using modern least-squares finite element methods for the solution of the optimality systems. The matrix equations resulting from this approach are symmetric and positive definite and are readily amenable to uncoupling strategies. This is an important advantage of least-squares principles as they allow for a more efficient computational solution of the optimization problem. We develop an abstract theory that includes optimal error estimates for least-squares finite element methods applied to optimality systems. We then provide an application of the theory to optimization problems for the Stokes equations. C1 Sandia Natl Labs, Computat Math & Algorithms Dept, Albuquerque, NM 87185 USA. Florida State Univ, Sch Computat Sci, Tallahassee, FL 32306 USA. RP Bochev, P (reprint author), Sandia Natl Labs, Computat Math & Algorithms Dept, Albuquerque, NM 87185 USA. EM pbboche@sandia.gov; gunzburg@csit.fsu.edu NR 22 TC 12 Z9 12 U1 0 U2 3 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1429 J9 SIAM J NUMER ANAL JI SIAM J. Numer. Anal. PY 2006 VL 43 IS 6 BP 2517 EP 2543 DI 10.1137/040607848 PG 27 WC Mathematics, Applied SC Mathematics GA 013RI UT WOS:000235426500012 ER PT J AU Leyffer, S Lopez-Calva, G Nocedal, J AF Leyffer, Sven Lopez-Calva, Gabriel Nocedal, Jorge TI Interior methods for mathematical programs with complementarity constraints SO SIAM JOURNAL ON OPTIMIZATION LA English DT Article DE mathematical programs with complementarity constraints; nonlinear programming; interior-point methods; exact penalty; equilibrium constraints; complementarity constraints ID EQUILIBRIUM CONSTRAINTS; POINT ALGORITHM; OPTIMIZATION; CONVERGENCE; REGULARIZATION; SCHEME AB This paper studies theoretical and practical properties of interior-penalty methods for mathematical programs with complementarity constraints. A framework for implementing these methods is presented, and the need for adaptive penalty update strategies is motivated with examples. The algorithm is shown to be globally convergent to strongly stationary points, under standard assumptions. These results are then extended to an interior-relaxation approach. Superlinear convergence to strongly stationary points is also established. Two strategies for updating the penalty parameter are proposed, and their efficiency and robustness are studied on an extensive collection of test problems. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Northwestern Univ, Dept Ind Engn & Management Sci, Evanston, IL 60208 USA. Northwestern Univ, Dept Elect Engn & Comp Sci, Evanston, IL 60208 USA. RP Leyffer, S (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM leyffer@mcs.anl.gov; g-lopez-calva@northwestern.edu; nocedal@ece.nrthwestern.edu RI Nocedal, Jorge/B-7255-2009 NR 26 TC 75 Z9 81 U1 0 U2 2 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1052-6234 J9 SIAM J OPTIMIZ JI SIAM J. Optim. PY 2006 VL 17 IS 1 BP 52 EP 77 DI 10.1137/040621065 PG 26 WC Mathematics, Applied SC Mathematics GA 053SK UT WOS:000238325200003 ER PT J AU Fletcher, R Leyffer, S Ralph, D Scholtes, S AF Fletcher, R Leyffer, S Ralph, D Scholtes, S TI Local convergence of SQP methods for mathematical programs with equilibrium constraints SO SIAM JOURNAL ON OPTIMIZATION LA English DT Article DE nonlinear programming; sequential quadratic programming (SQP); mathematical programs with equilibrium constraints (MPEC); mathematical programs with complementarity constraints (MPCC); equilibrium constraints ID COMPLEMENTARITY CONSTRAINTS; NONLINEAR PROGRAMS; OPTIMIZATION; ALGORITHM AB Recently, nonlinear programming solvers have been used to solve a range of mathematical programs with equilibrium constraints (MPECs). In particular, sequential quadratic programming (SQP) methods have been very successful. This paper examines the local convergence properties of SQP methods applied to MPECs. SQP is shown to converge superlinearly under reasonable assumptions near a strongly stationary point. A number of examples are presented that show that some of the assumptions are difficult to relax. C1 Univ Dundee, Dept Math, Dundee DD1 4HN, Scotland. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Univ Cambridge, Judge Inst, Cambridge CB2 1AG, England. RP Fletcher, R (reprint author), Univ Dundee, Dept Math, Dundee DD1 4HN, Scotland. EM fletcher@maths.dundee.ac.uk; leyffer@mcs.anl.gov; ralph@jims.cam.ac.uk; s.scholtes@jims.cam.ac.uk NR 22 TC 92 Z9 99 U1 2 U2 8 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1052-6234 J9 SIAM J OPTIMIZ JI SIAM J. Optim. PY 2006 VL 17 IS 1 BP 259 EP 286 DI 10.1137/S1052623402407382 PG 28 WC Mathematics, Applied SC Mathematics GA 053SK UT WOS:000238325200012 ER PT J AU Boggs, PT Long, KR Margolis, SB Howard, PA AF Boggs, Paul T. Long, Kevin R. Margolis, Stephen B. Howard, Patricia A. TI Rapid source inversion for chemical/biological attacks, part 1: The steady-state case SO SIAM JOURNAL ON OPTIMIZATION LA English DT Article DE source inversion; PDE-constrained optimization; software environments; adaptive meshes; Sundance; O3D; Split; Trilinos; TSF ID NONLINEAR OPTIMIZATION PROBLEMS; ALGORITHM AB A critical first step in responding to an airborne chemical or biological attack is determining the location of the source of the toxin. We have formulated the mathematical description of source location as an inverse problem constrained by the partial differential equation (PDE) that describes the toxin's transport. This transport is advection-dominated, but takes place in a flow field that in realistic settings will be turbulent, thereby inducing an effective diffusivity tensor in the transport model. We model the turbulent flow using a Reynolds-averaged Navier - Stokes (RANS) approach, which can be solved offline for an arbitrary building of interest. The inversion problem then consists of finding the ( regularized) source distribution that best reproduces a set of sensor measurements, subject to the transport model constraint relating the source to the concentration at the sensor positions. Though individual toxin sources are likely to be point sources, we cannot make any assumptions about the number of such sources. Hence, because multiple sources are a possibility, we assume a spatially continuous source distribution, thus eliminiating any need to impose assumptions about the number and nature of the sources. The operational context for this problem implies certain practical requirements. In particular, it is critical to reduce the time for inversion and the number of sensors required for an accurate determination of the source field. A particular focus of this paper is the exploration of the degree to which we can economize on computational effort through adaptive mesh coarsening tailored to preserve the essential features of the flow field. We have found that location of multiple sources is well accommodated by this method, and have shown that it is possible to reduce significantly the computational time through flow-tailored mesh adaptation without adverse impact on the accuracy of the source location. Finally, we have done a preliminary study of the number of sensors required for useful inversion. These conclusions will be of considerable use in developing sensor deployment strategies. C1 Sandia Natl Labs, Computat Sci & Math Res Dept, Livermore, CA 94551 USA. Rice Univ, Dept Computat & Appl Math, Houston, TX 77251 USA. RP Boggs, PT (reprint author), Sandia Natl Labs, Computat Sci & Math Res Dept, Livermore, CA 94551 USA. EM ptboggs@sandia.gov; krlong@sandia.gov; margoli@sandia.gov; pahoward@caam.rice.edu NR 27 TC 2 Z9 2 U1 0 U2 6 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1052-6234 J9 SIAM J OPTIMIZ JI SIAM J. Optim. PY 2006 VL 17 IS 2 BP 430 EP 458 DI 10.1137/040603036 PG 29 WC Mathematics, Applied SC Mathematics GA 086QL UT WOS:000240688000006 ER PT J AU Kolda, TG Lewis, RM Torczon, V AF Kolda, Tamara G. Lewis, Robert Michael Torczon, Virginia TI Stationarity results for generating set search for linearly constrained optimization SO SIAM JOURNAL ON OPTIMIZATION LA English DT Article DE constrained optimization; linear constraints; global convergence analysis; direct search; generating set search; generalized pattern search; derivative-free methods; stopping criteria ID DERIVATIVE-FREE METHODS; PATTERN SEARCH; UNCONSTRAINED OPTIMIZATION; GLOBAL CONVERGENCE; MINIMIZATION; ALGORITHM AB We present a new generating set search (GSS) approach for minimizing functions subject to linear constraints. GSS is a class of direct search optimization methods that includes generalized pattern search. One of our main contributions in this paper is a new condition to de. ne the set of conforming search directions that admits several computational advantages. For continuously differentiable functions we also derive a bound relating a measure of stationarity, which is equivalent to the norm of the gradient of the objective in the unconstrained case, and a parameter used by GSS algorithms to control the lengths of the steps. With the additional assumption that the derivative is Lipschitz, we obtain a big-O bound. As a consequence of this relationship, we obtain subsequence convergence to a KKT point, even though GSS algorithms lack explicit gradient information. Numerical results indicate that the bound provides a reasonable estimate of stationarity. C1 Sandia Natl Labs, Computat Sci & Math Res Dept, Livermore, CA 94551 USA. Coll William & Mary, Dept Math, Williamsburg, VA 23187 USA. Coll William & Mary, Dept Comp Sci, Williamsburg, VA 23187 USA. RP Kolda, TG (reprint author), Sandia Natl Labs, Computat Sci & Math Res Dept, Livermore, CA 94551 USA. EM tgkolda@sandia.gov; buckaroo@math.wm.edu; va@cs.wm.edu RI Kolda, Tamara/B-1628-2009 OI Kolda, Tamara/0000-0003-4176-2493 NR 36 TC 38 Z9 38 U1 0 U2 3 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1052-6234 J9 SIAM J OPTIMIZ JI SIAM J. Optim. PY 2006 VL 17 IS 4 BP 943 EP 968 DI 10.1137/S1052623403433638 PG 26 WC Mathematics, Applied SC Mathematics GA 142EI UT WOS:000244631800001 ER PT J AU Dolan, ED More, JJ Munson, TS AF Dolan, ED More, JJ Munson, TS TI Optimality measures for performance profiles SO SIAM JOURNAL ON OPTIMIZATION LA English DT Article DE benchmarking; optimality conditions; performance profiles; scale invariance ID CONSTRAINED OPTIMIZATION AB We examine the importance of optimality measures when benchmarking a set of solvers and show that the scale-invariance requirements we impose lead to a convergence test for nonlinearly constrained optimization solvers that uses a mixture of absolute and relative error measures. We demonstrate that this convergence test is well behaved at any point where the constraints satisfy the Mangasarian-Fromovitz constraint qualification and also avoids the explicit use of a complementarity measure. Computational experiments explore the impact of this convergence test on the benchmarking process with performance profiles. C1 Univ N Carolina, Dept Comp Sci, Chapel Hill, NC 27599 USA. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Dolan, ED (reprint author), Univ N Carolina, Dept Comp Sci, Chapel Hill, NC 27599 USA. EM dolan@cs.unc.edu; more@mcs.anl.gov; tmunson@mcs.anl.gov NR 17 TC 15 Z9 15 U1 0 U2 1 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1052-6234 J9 SIAM J OPTIMIZ JI SIAM J. Optim. PY 2006 VL 16 IS 3 BP 891 EP 909 DI 10.1137/040608015 PG 19 WC Mathematics, Applied SC Mathematics GA 009RA UT WOS:000235128800012 ER PT J AU Griebel, M Oeltz, D Vassilevski, P AF Griebel, Michael Oeltz, Daniel Vassilevski, Panayot TI Space-time approximation with sparse grids SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE parabolic differential equations; multilevel basis; sparse grids; space-time discretization ID ELLIPTIC PROBLEMS; WAVELETS; INTERPOLATION; CONSTRUCTION; BASES; PDES AB In this article we introduce approximation spaces, especially suited for the approximation of solutions of parabolic problems, which are based on the tensor product construction of a multiscale basis in space and a multiscale basis in time. Proper truncation then leads to so-called space-time sparse grid spaces. For a uniform discretization of the spatial space of dimension d with O(N-d) degrees of freedom, these spaces involve for d > 1 also only O(Nd) degrees of freedom for the discretization of the whole space-time problem. But they provide the same approximation rate as classical space-time finite element spaces which need O(Nd+1) degrees of freedoms. This makes these approximation spaces well suited for conventional parabolic and time-dependent optimization problems. We analyze the approximation properties and the dimension of these sparse grid space-time spaces for general stable multiscale bases. We then restrict ourselves to an interpolatory multiscale basis, i.e., a hierarchical basis. Here, to be able to handle also complicated spatial domains Omega, we construct the hierarchical basis from a given spatial finite element basis as follows: First we determine coarse grid points recursively over the levels by the coarsening step of the algebraic multigrid method. Then, we derive interpolatory prolongation operators between the respective coarse and. ne grid points by a least squares approach. This way we obtain an algebraic hierarchical basis for the spatial domain which we then use in our space-time sparse grid approach. We give numerical results on the convergence rate of the interpolation error of these spaces for various space-time problems with two spatial dimensions. Implementational issues, data structures, and questions of adaptivity also are addressed to some extent. C1 Univ Bonn, Inst Numer Simulat, D-53115 Bonn, Germany. Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. RP Griebel, M (reprint author), Univ Bonn, Inst Numer Simulat, Wegelerstr 6, D-53115 Bonn, Germany. EM griebel@ins.uni-bonn.de; oeltz@ins.uni-bonn.de; panayot@llnl.gov NR 50 TC 5 Z9 5 U1 1 U2 3 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2006 VL 28 IS 2 BP 701 EP 727 DI 10.1137/050629252 PG 27 WC Mathematics, Applied SC Mathematics GA 053SN UT WOS:000238325500015 ER PT J AU Xiu, DB Tartakovsky, DM AF Xiu, Dongbin Tartakovsky, Daniel M. TI Numerical methods for differential equations in random domains SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE random domain; stochastic inputs; differential equations; uncertainty quantification ID GENERALIZED POLYNOMIAL CHAOS; BOUNDARY-VALUE-PROBLEMS; MODELING UNCERTAINTY; FINITE-ELEMENTS; POROUS MATERIAL; ROUGH SURFACES; TRANSPORT; SIMULATION; DYNAMICS; CONTACT AB Physical phenomena in domains with rough boundaries play an important role in a variety of applications. Often the topology of such boundaries cannot be accurately described in all of its relevant detail due to either insufficient data or measurement errors or both. This topological uncertainty can be efficiently handled by treating rough boundaries as random fields, so that an underlying physical phenomenon is described by deterministic or stochastic differential equations in random domains. To deal with this class of problems, we propose a novel computational framework, which is based on using stochastic mappings to transform the original deterministic/stochastic problem in a random domain into a stochastic problem in a deterministic domain. The latter problem has been studied more extensively, and existing analytical/numerical techniques can be readily applied. In this paper, we employ both a stochastic Galerkin method and Monte Carlo simulations to solve the transformed stochastic problem. We demonstrate our approach by applying it to an elliptic problem in single- and double-connected random domains, and comment on the accuracy and convergence of the numerical methods. C1 Purdue Univ, Dept Math, W Lafayette, IN 47907 USA. Univ Calif San Diego, Dept Mech & Aerosp Engn, La Jolla, CA 92093 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Xiu, DB (reprint author), Purdue Univ, Dept Math, W Lafayette, IN 47907 USA. EM dxiu@math.purdue.edu; dmt@ucsd.edu RI Tartakovsky, Daniel/E-7694-2013 NR 39 TC 72 Z9 72 U1 0 U2 9 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2006 VL 28 IS 3 BP 1167 EP 1185 DI 10.1137/040613160 PG 19 WC Mathematics, Applied SC Mathematics GA 072VM UT WOS:000239701100018 ER PT J AU Marques, OA Riedy, EJ Vomel, C AF Marques, Osni A. Riedy, E. Jason Vomel, Christof TI Benefits of IEEE-754 features in modern symmetric tridiagonal eigensolvers SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE IEEE-754 arithmetic; NaN arithmetic; IEEE-754 performance; differential qds algorithms; MRRR algorithm; LAPACK ID ACCURATE SINGULAR-VALUES; QD-ALGORITHMS; MATRICES; REPRESENTATIONS AB Bisection is one of the most common methods used to compute the eigenvalues of symmetric tridiagonal matrices. Bisection relies on the Sturm count: For a given shift sigma, the number of negative pivots in the factorization T - sigma I = LDLT equals the number of eigenvalues of T that are smaller than sigma. In IEEE-754 arithmetic, the value infinity permits the computation to continue past a zero pivot, producing a correct Sturm count when T is unreduced. Demmel and Li showed [IEEE Trans. Comput., 43 (1994), pp. 983 - 992] that using 8 rather than testing for zero pivots within the loop could significantly improve performance on certain architectures. When eigenvalues are to be computed to high relative accuracy, it is often preferable to work with LDLT factorizations instead of the original tridiagonal T. One important example is the MRRR algorithm. When bisection is applied to the factored matrix, the Sturm count is computed from LDLT which makes differential stationary and progressive qds algorithms the methods of choice. While it seems trivial to replace T by LDLT, in reality these algorithms are more complicated: In IEEE-754 arithmetic, a zero pivot produces an overflow followed by an invalid exception (NaN, or "Not a Number") that renders the Sturm count incorrect. We present alternative, safe formulations that are guaranteed to produce the correct result. Benchmarking these algorithms on a variety of platforms shows that the original formulation without tests is always faster provided that no exception occurs. The transforms see speed-ups of up to 2.6 x over the careful formulations. Tests on industrial matrices show that encountering exceptions in practice is rare. This leads to the following design: First, compute the Sturm count by the fast but unsafe algorithm. Then, if an exception occurs, recompute the count by a safe, slower alternative. The new Sturm count algorithms improve the speed of bisection by up to 2 x on our test matrices. Furthermore, unlike the traditional tiny-pivot substitution, proper use of IEEE-754 features provides a careful formulation that imposes no input range restrictions. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Div Comp Sci, Berkeley, CA 94720 USA. RP Marques, OA (reprint author), Lawrence Berkeley Natl Lab, 1 Cyclotron Rd,MS 50F-1650, Berkeley, CA 94720 USA. EM oamarques@lbl.gov; ejr@cs.berkeley.edu; cvoemel@lbl.gov RI Riedy, Jason/E-7647-2016 OI Riedy, Jason/0000-0002-4345-4200 NR 32 TC 4 Z9 4 U1 0 U2 1 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2006 VL 28 IS 5 BP 1613 EP 1633 DI 10.1137/050641624 PG 21 WC Mathematics, Applied SC Mathematics GA 113BV UT WOS:000242573400002 ER PT J AU Parks, ML De Sturler, E Mackey, G Johnson, DD Maiti, S AF Parks, Michael L. De Sturler, Eric Mackey, Greg Johnson, Duane D. Maiti, Spandan TI Recycling Krylov subspaces for sequences of linear systems SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE sequence of linear systems; linear solvers; Krylov methods; truncation; restarting; Krylov subspace recycling; iterative methods ID CONJUGATE-GRADIENT ALGORITHM; SCALE NONLINEAR PROBLEMS; RIGHT-HAND SIDES; SUPERLINEAR CONVERGENCE; NONSYMMETRIC SYSTEMS; ITERATIVE SOLUTION; ARNOLDI METHODS; GMRES; PRECONDITIONER; STRATEGIES AB Many problems in science and engineering require the solution of a long sequence of slowly changing linear systems. We propose and analyze two methods that significantly reduce the total number of matrix-vector products required to solve all systems. We consider the general case where both the matrix and right-hand side change, and we make no assumptions regarding the change in the right-hand sides. Furthermore, we consider general nonsingular matrices, and we do not assume that all matrices are pairwise close or that the sequence of matrices converges to a particular matrix. Our methods work well under these general assumptions, and hence form a significant advancement with respect to related work in this area. We can reduce the cost of solving subsequent systems in the sequence by recycling selected subspaces generated for previous systems. We consider two approaches that allow for the continuous improvement of the recycled subspace at low cost. We consider both Hermitian and non-Hermitian problems, and we analyze our algorithms both theoretically and numerically to illustrate the effects of subspace recycling. We also demonstrate the effectiveness of our algorithms for a range of applications from computational mechanics, materials science, and computational physics. C1 Univ Illinois, Dept Comp Sci, Urbana, IL 61801 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Virginia Tech, Dept Math, Blacksburg, VA 24061 USA. Univ Illinois, Dept Mat Sci, Urbana, IL 61801 USA. Univ Illinois, Dept Aerosp Engn, Urbana, IL 61801 USA. RP Parks, ML (reprint author), Univ Illinois, Dept Comp Sci, 1304 W Springfield Ave, Urbana, IL 61801 USA. EM mlparks@sandia.gov; sturler@vt.edu; gemacke@sandia.gov; duanej@uiuc.edu; maiti@uiuc.edu RI Parks, Michael/A-2878-2008; de Sturler, Eric/C-5014-2008; OI de Sturler, Eric/0000-0002-9412-9360; Johnson, Duane/0000-0003-0794-7283 NR 39 TC 113 Z9 115 U1 1 U2 14 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2006 VL 28 IS 5 BP 1651 EP 1674 DI 10.1137/040607277 PG 24 WC Mathematics, Applied SC Mathematics GA 113BV UT WOS:000242573400004 ER PT J AU Henshaw, WD AF Henshaw, William D. TI A high-order accurate parallel solver for Maxwell's equations on overlapping grids SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE Maxwell's equations; overlapping grids; high-order accurate; symmetric finite difference ID SINGULAR FIELD METHOD; TIME-DOMAIN FDTD; WAVE-PROPAGATION; POLYHEDRAL DOMAINS; UNSTRUCTURED GRIDS; DIFFERENCE-METHODS; FINITE-ELEMENTS; ALGORITHM; SCATTERING; MEDIA AB A scheme for the solution of the time-dependent Maxwell's equations on composite overlapping grids is described. The method uses high-order accurate approximations in space and time for Maxwell's equations written as a second-order vector wave equation. High-order accurate symmetric difference approximations to the generalized Laplace operator are constructed for curvilinear component grids. The modified equation approach is used to develop high-order accurate approximations that use only three time levels and have the same time-stepping restriction as the second-order scheme. Discrete boundary conditions for perfect electrical conductors and for material interfaces are developed and analyzed. The implementation is optimized for component grids that are Cartesian, resulting in a fast and efficient method. The solver runs on parallel machines with each component grid distributed across one or more processors. Numerical results in two and three dimensions are presented for the fourth-order accurate version of the method. These results demonstrate the accuracy and efficiency of the approach. C1 Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. RP Henshaw, WD (reprint author), Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. EM henshaw1@llnl.gov NR 45 TC 24 Z9 24 U1 1 U2 2 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2006 VL 28 IS 5 BP 1730 EP 1765 DI 10.1137/050644379 PG 36 WC Mathematics, Applied SC Mathematics GA 113BV UT WOS:000242573400008 ER PT J AU Kreiss, HO Petersson, NA AF Kreiss, HO Petersson, NA TI A second order accurate embedded boundary method for the wave equation with Dirichlet data SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE wave equation; stability; accuracy; embedded boundary ID DIFFERENCE APPROXIMATIONS AB The accuracy of Cartesian embedded boundary methods for the second order wave equation in general two-dimensional domains subject to Dirichlet boundary conditions is analyzed. Based on the analysis, we develop a numerical method where both the solution and its gradient are second order accurate. We avoid the small-cell stiffness problem without sacrificing the second order accuracy by adding a small artificial term to the Dirichlet boundary condition. Long-time stability of the method is obtained by adding a small fourth order dissipative term. Several numerical examples are provided to demonstrate the accuracy and stability of the method. The method is also used to solve the two-dimensional TMz problem for Maxwell's equations posed as a second order wave equation for the electric field coupled to ordinary differential equations for the magnetic field. C1 Univ Calif Los Angeles, Dept Math, Los Angeles, CA 90024 USA. Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. RP Kreiss, HO (reprint author), Univ Calif Los Angeles, Dept Math, Los Angeles, CA 90024 USA. EM kreiss@math.ucla.edu; andersp@llnl.gov NR 16 TC 34 Z9 34 U1 0 U2 2 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2006 VL 27 IS 4 BP 1141 EP 1167 DI 10.1137/040604728 PG 27 WC Mathematics, Applied SC Mathematics GA 010SA UT WOS:000235215900001 ER PT J AU Brezina, M Falgout, R Maclachlan, S Manteuffel, T Mccormick, S Ruge, J AF Brezina, M Falgout, R Maclachlan, S Manteuffel, T Mccormick, S Ruge, J TI Adaptive algebraic multigrid SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE iterative methods; algebraic multigrid (AMG); adaptive method ID SMOOTHED AGGREGATION; PARAMETERS; RELAXATION AB Efficient numerical simulation of physical processes is constrained by our ability to solve the resulting linear systems, prompting substantial research into the development of multiscale iterative methods capable of solving these linear systems with an optimal amount of effort. Overcoming the limitations of geometric multigrid methods to simple geometries and differential equations, algebraic multigrid methods construct the multigrid hierarchy based only on the given matrix. While this allows for efficient black-box solution of the linear systems associated with discretizations of many elliptic differential equations, it also results in a lack of robustness due to unsatisfied assumptions made on the near null spaces of these matrices. This paper introduces an extension to algebraic multigrid methods that removes the need to make such assumptions by utilizing an adaptive process. Emphasis is on the principles that guide the adaptivity and their application to algebraic multigrid solution of certain symmetric positive-definite linear systems. C1 Univ Colorado, Dept Appl Math, Boulder, CO 80309 USA. Lawrence Livermore Natl Lab, Ctr Appl Sci Computat, Livermore, CA 94551 USA. RP Brezina, M (reprint author), Univ Colorado, Dept Appl Math, Campus Box 526, Boulder, CO 80309 USA. EM mbrezina@math.cudenver.edu; rfalgout@llnl.gov; maclachl@colorado.edu; tmanteuf@colorado.edu; stevem@colorado.edu; jruge@colorado.edu NR 33 TC 63 Z9 68 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2006 VL 27 IS 4 BP 1261 EP 1286 DI 10.1137/040614402 PG 26 WC Mathematics, Applied SC Mathematics GA 010SA UT WOS:000235215900006 ER PT J AU Prudencio, EE Byrd, R Cai, XC AF Prudencio, EE Byrd, R Cai, XC TI Parallel full space SQP Lagrange-Newton-Krylov-Schwarz algorithms for PDE-constrained optimization problems SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE nonlinear partial differential equations constrained optimization; inexact Newton method; domain decomposition; Schwarz preconditioners; parallel computing; flow control; incompressible Navier-Stokes equations ID NAVIER-STOKES EQUATIONS; LINEAR-SYSTEMS; SCHUR METHODS; FLOW-CONTROL; PRECONDITIONERS; APPROXIMATION; MATRICES; OVERLAP; SOLVER; FORM AB Optimization problems constrained by nonlinear partial differential equations have been the focus of intense research in scientific computing lately. Current methods for the parallel numerical solution of such problems involve sequential quadratic programming (SQP), with either reduced or full space approaches. In this paper we propose and investigate a class of parallel full space SQP Lagrange-Newton-Krylov-Schwarz (LNKSz) algorithms. In LNKSz, a Lagrangian functional is formed and differentiated to obtain a Karush-Kuhn-Tucker (KKT) system of nonlinear equations. An inexact Newton method with line search is then applied. At each Newton iteration the linearized KKT system is solved with a Schwarz preconditioned Krylov subspace method. We apply LNKSz to the parallel numerical solution of some boundary control problems of two-dimensional incompressible Navier-Stokes equations. Numerical results are reported for different combinations of Reynolds number, mesh size, and number of parallel processors. We also compare the application of the LNKSz method to flow control problems against the application of the Newton-Krylov-Schwarz (NKSz) method to flow simulation problems. C1 Stanford Linear Accelerator Ctr, Adv Computat Dept, Menlo Pk, CA 94025 USA. Univ Colorado, Dept Comp Sci, Boulder, CO 80309 USA. RP Prudencio, EE (reprint author), Stanford Linear Accelerator Ctr, Adv Computat Dept, Menlo Pk, CA 94025 USA. EM prudenci@slac.stanford.edu; richard@cs.colorado.edu; cai@cs.colorado.edu NR 45 TC 25 Z9 25 U1 0 U2 4 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2006 VL 27 IS 4 BP 1305 EP 1328 DI 10.1137/040602997 PG 24 WC Mathematics, Applied SC Mathematics GA 010SA UT WOS:000235215900008 ER PT J AU Brezina, M Tong, C Becker, R AF Brezina, M Tong, C Becker, R TI Parallel algebraic multigrids for structural mechanics SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article; Proceedings Paper CT Copper Mountain Conference on Iterative Methods CY MAR 28-APR 02, 2004 CL Copper Mt, CO DE algebraic multigrid; preconditioning; parallel computing ID SMOOTHED AGGREGATION; SOLVER; ALGORITHM AB This paper presents the results of a comparison of three parallel algebraic multigrid (AMG) preconditioners for structural mechanics applications. In particular, we are interested in investigating both the scalability and robustness of the preconditioners. Numerical results are given for a range of structural mechanics problems with various degrees of difficulty, and they show that algebraic multigrid methods can be applied successfully even to difficult problems in structural mechanics. C1 Univ Colorado, Dept Appl Math, Boulder, CO 80309 USA. Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. Lawrence Livermore Natl Lab, New Technol & Engn Div, Livermore, CA 94551 USA. RP Brezina, M (reprint author), Univ Colorado, Dept Appl Math, Campus Box 526, Boulder, CO 80309 USA. EM mbrezina@math.cudenver.edu; chtong@llnl.gov; becker13@llnl.gov RI Becker, Richard/I-1196-2013 NR 29 TC 8 Z9 8 U1 0 U2 2 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2006 VL 27 IS 5 BP 1534 EP 1554 DI 10.1137/040608271 PG 21 WC Mathematics, Applied SC Mathematics GA 010SB UT WOS:000235216100003 ER PT J AU Baker, AH Dennis, JM Jessup, ER AF Baker, AH Dennis, JM Jessup, ER TI On improving linear solver performance: A block variant of GMRES SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article; Proceedings Paper CT Copper Mountain Conference on Iterative Methods CY MAR 28-APR 02, 2004 CL Copper Mt, CO DE GMRES; block GMRES; iterative methods; Krylov subspace; memory access costs ID RESTARTED GMRES; ALGORITHM; SYSTEMS; CONVERGENCE; STRATEGIES AB The increasing gap between processor performance and memory access time warrants the re-examination of data movement in iterative linear solver algorithms. For this reason, we explore and establish the feasibility of modifying a standard iterative linear solver algorithm in a manner that reduces the movement of data through memory. In particular, we present an alternative to the restarted GMRES algorithm for solving a single right-hand side linear system Ax=b based on solving the block linear system AX=B. Algorithm performance, i.e., time to solution, is improved by using the matrix A in operations on groups of vectors. Experimental results demonstrate the importance of implementation choices on data movement as well as the effectiveness of the new method on a variety of problems from different application areas. C1 Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. Natl Ctr Atmospher Res, Div Comp Sci, Boulder, CO 80307 USA. Univ Colorado, Dept Comp Sci, Boulder, CO 80309 USA. RP Baker, AH (reprint author), Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Box 808 L-551, Livermore, CA 94551 USA. EM abaker@llnl.gov; dennis@ucar.edu; jessup@cs.colorado.edu NR 44 TC 16 Z9 16 U1 0 U2 1 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2006 VL 27 IS 5 BP 1608 EP 1626 DI 10.1137/040608088 PG 19 WC Mathematics, Applied SC Mathematics GA 010SB UT WOS:000235216100007 ER PT J AU Elman, H Howle, VE Shadid, J Shuttleworth, R Tuminaro, R AF Elman, H Howle, VE Shadid, J Shuttleworth, R Tuminaro, R TI Block preconditioners based on approximate commutators SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article; Proceedings Paper CT Copper Mountain Conference on Iterative Methods CY MAR 28-APR 02, 2004 CL Copper Mt, CO DE preconditioning; Navier-Stokes; iterative algorithms ID NAVIER-STOKES EQUATIONS; INCOMPRESSIBLE-FLOW AB This paper introduces a strategy for automatically generating a block preconditioner for solving the incompressible Navier-Stokes equations. We consider the "pressure convection diffusion preconditioners" proposed by Kay, Loghin, and Wathen [SIAM J. Sci. Comput., 24 (2002), pp. 237-256] and Silvester, Elman, Kay, and Wathen [J. Comput. Appl. Math., 128 (2001), pp. 261-279]. Numerous theoretical and numerical studies have demonstrated mesh independent convergence on several problems and the overall efficacy of this methodology. A drawback, however, is that it requires the construction of a convection-diffusion operator (denoted F-p) projected onto the discrete pressure space. This means that integration of this idea into a code that models incompressible flow requires a sophisticated understanding of the discretization and other implementation issues, something often held only by the developers of the model. As an alternative, we consider automatic ways of computing F-p based on purely algebraic considerations. The new methods are closely related to the "BFBt preconditioner" of Elman [SIAM J. Sci. Comput., 20 (1999), pp. 1299-1316]. We use the fact that the preconditioner is derived from considerations of commutativity between the gradient and convection-diffusion operators, together with methods for computing sparse approximate inverses, to generate the required matrix F-p automatically. We demonstrate that with this strategy the favorable convergence properties of the preconditioning methodology are retained. C1 Univ Maryland, Dept Comp Sci, College Pk, MD 20742 USA. Univ Maryland, Inst Adv Comp Studies, College Pk, MD 20742 USA. Sandia Natl Labs, Livermore, CA 94551 USA. Univ Maryland, Appl Math & Sci Comp Program, College Pk, MD 20742 USA. RP Elman, H (reprint author), Univ Maryland, Dept Comp Sci, College Pk, MD 20742 USA. EM elman@cs.umd.edu; vehowle@sandia.gov; jnshadi@cs.sandia.gov; rshuttle@math.umd.edu; rstumin@sandia.gov RI Elman, Howard/F-6517-2011 OI Elman, Howard/0000-0002-8886-9901 NR 18 TC 56 Z9 56 U1 0 U2 3 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2006 VL 27 IS 5 BP 1651 EP 1668 DI 10.1137/040608817 PG 18 WC Mathematics, Applied SC Mathematics GA 010SB UT WOS:000235216100009 ER PT J AU Hu, JJ Tuminaro, RS Bochev, PB Garasi, CJ Robinson, AC AF Hu, JJ Tuminaro, RS Bochev, PB Garasi, CJ Robinson, AC TI Toward an h-independent algebraic multigrid method for Maxwell's equations SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article; Proceedings Paper CT Copper Mountain Conference on Iterative Methods CY MAR 28-APR 02, 2004 CL Copper Mt, CO DE Maxwell's equations; eddy currents; AMG; multigrid; smoothed aggregation ID FINITE-ELEMENT DISCRETIZATIONS; SMOOTHED AGGREGATION; ELLIPTIC PROBLEMS; EDGE-ELEMENTS; CONVERGENCE AB We propose a new algebraic multigrid (AMG) method for solving the eddy current approximations to Maxwell's equations. This AMG method has its roots in an algorithm proposed by Reitzinger and Schoberl. The main focus in the Reitzinger and Schoberl method is to maintain null-space properties of the weak del x del x operator on coarse grids. While these null-space properties are critical, they are not enough to guarantee h-independent convergence rates of the overall multigrid scheme. We present a new strategy for choosing intergrid transfers that not only maintains the important null-space properties on coarse grids but also yields significantly improved multigrid convergence rates. This improvement is related to those we explored in a previous paper, but is fundamentally simpler, easier to compute, and performs better with respect to both multigrid operator complexity and convergence rates. The new strategy builds on ideas in smoothed aggregation to improve the approximation property of an existing interpolation operator. By carefully choosing the smoothing operators, we show how it is sometimes possible to achieve h-independent convergence rates with a modest increase in multigrid operator complexity. Though this ideal case is not always possible, the overall algorithm performs significantly better than the original scheme in both iterations and run time. Finally, the Reitzinger and Schoberl method, as well as our previous smoothed method, are shown to be special cases of this new algorithm. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Hu, JJ (reprint author), Sandia Natl Labs, POB 969,MS 9159, Livermore, CA 94551 USA. EM jhu@sandia.gov; rstumin@sandia.gov; pbboche@sandia.gov; cjgaras@sandia.gov; acrobin@sandia.gov NR 16 TC 23 Z9 23 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2006 VL 27 IS 5 BP 1669 EP 1688 DI 10.1137/040608118 PG 20 WC Mathematics, Applied SC Mathematics GA 010SB UT WOS:000235216100010 ER PT J AU Jones, J Lee, B AF Jones, J Lee, B TI A multigrid method for variable coefficient Maxwell's equations SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article; Proceedings Paper CT Copper Mountain Conference on Iterative Methods CY MAR 28-APR 02, 2004 CL Copper Mt, CO DE Maxwell's equations; multigrid method; edge finite elements ID FINITE-ELEMENT DISCRETIZATIONS; EDGE ELEMENTS; ITERATIVE METHODS; SYSTEMS AB This paper presents a multigrid method for solving variable coefficient Maxwell's equations. The novelty in this method is the use of interpolation operators that do not produce multilevel commutativity complexes that lead to multilevel exactness. Rather, the effects of multilevel exactness are built into the level equations themselves-on the finest level using a discrete T-V formulation and on the coarser grids through the Galerkin coarsening procedure of a T-V formulation. These built-in structures permit the levelwise use of an effective hybrid smoother on the curl-free near-nullspace components and permit the development of interpolation operators for handling the curl-free and divergence-free error components separately. The resulting block-diagonal interpolation operator does not satisfy multilevel commutativity but has good approximation properties for both of these error components. Applying operator-dependent interpolation for each of these error components leads to an effective multigrid scheme for variable coeffcient Maxwell's equations, where multilevel commutativity-based methods can degrade. Numerical results are presented to verify the effectiveness of this new scheme. C1 Florida Inst Technol, Dept Math Sci, Melbourne, FL 32901 USA. Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA USA. RP Jones, J (reprint author), Florida Inst Technol, Dept Math Sci, 150 W Univ Blvd, Melbourne, FL 32901 USA. EM jim@fit.edu; lee123@llnl.gov OI Jones, Jim/0000-0002-0144-6130 NR 22 TC 7 Z9 8 U1 1 U2 1 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2006 VL 27 IS 5 BP 1689 EP 1708 DI 10.1137/040608283 PG 20 WC Mathematics, Applied SC Mathematics GA 010SB UT WOS:000235216100011 ER PT J AU Pernice, M Philip, B AF Pernice, M Philip, B TI Solution of equilibrium radiation diffusion problems using implicit adaptive mesh refinement SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article; Proceedings Paper CT Copper Mountain Conference on Iterative Methods CY MAR 28-APR 02, 2004 CL Copper Mt, CO DE adaptive mesh refinement; implicit time integration; Newton-Krylov methods; fast adaptive composite grid; multilevel preconditioning; radiation diffusion ID UNIFORM GRID REFINEMENT; INEXACT NEWTON METHODS; TIME-INTEGRATION; KRYLOV METHOD; EQUATIONS; HYDRODYNAMICS; PERFORMANCE; SOLVERS; 2D AB Diffusion approximations to radiation transport feature a nonlinear conduction coefficient that leads to formation of a sharp front, or Marshak wave, under suitable initial and boundary conditions. The front can vary several orders of magnitude over a very short distance. Resolving the shape of the Marshak wave is essential, but using a global. ne mesh can be prohibitively expensive. In such circumstances it is natural to consider using adaptive mesh refinement (AMR) to place a. ne mesh only in the vicinity of the propagating front. In addition, to avoid any loss of accuracy due to linearization, implicit time integration should be used to solve the equilibrium radiation diffusion equation. Implicit time integration on AMR grids introduces a new challenge, as algorithmic complexity must be controlled to fully realize the performance benefits of AMR. A Newton-Krylov method together with a multigrid preconditioner addresses this latter issue on a uniform grid. A straightforward generalization is to use a multilevel preconditioner that is tuned to the structure of the AMR grid, such as the fast adaptive composite grid (FAC) method. We describe the resulting Newton-Krylov-FAC method and demonstrate its performance on simple equilibrium radiation diffusion problems. C1 Los Alamos Natl Lab, Comp & Computat Sci Div, Los Alamos, NM 87545 USA. RP Pernice, M (reprint author), Los Alamos Natl Lab, Comp & Computat Sci Div, POB 1663, Los Alamos, NM 87545 USA. EM pernice@lanl.gov; bphilip@lanl.gov OI Philip, Bobby/0000-0001-6716-3515 NR 32 TC 10 Z9 12 U1 0 U2 4 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2006 VL 27 IS 5 BP 1709 EP 1726 DI 10.1137/040609069 PG 18 WC Mathematics, Applied SC Mathematics GA 010SB UT WOS:000235216100012 ER PT J AU Chow, E AF Chow, E TI An aggregation multilevel method using smooth error vectors SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article; Proceedings Paper CT Copper Mountain Conference on Iterative Methods CY MAR 28-APR 02, 2004 CL Copper Mt, CO DE preconditioning; multilevel and multigrid methods; smoothed aggregation ID ITERATIVE METHODS; INTERPOLATION; ALGORITHMS; AMGE AB Many algebraic multilevel methods for solving linear systems assume that the slowly converging, algebraically smooth error is locally constant. This assumption is often not true and can lead to poor performance of the method. Other multilevel methods require a description of the algebraically smooth error via knowledge of the near-nullspace of the operator, but this information may not always be available. This paper presents an aggregation multilevel method for problems where the near-nullspace of the operator is not known. The method uses samples of low-energy error vectors to construct its interpolation operator. The basis vectors for an aggregate are computed via a singular value decomposition of the sample vectors locally over that aggregate. Compared to many other methods that automatically adjust to the near-nullspace, this method does not require that the element stiffness matrices are available. C1 Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. RP Chow, E (reprint author), DE Shaw Res & Dev LLP, 39th Floor,120 W 45th St, New York, NY 10036 USA. EM edmond.chow@deshaw.com NR 25 TC 3 Z9 3 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2006 VL 27 IS 5 BP 1727 EP 1741 DI 10.1137/040608192 PG 15 WC Mathematics, Applied SC Mathematics GA 010SB UT WOS:000235216100013 ER PT S AU Skourikhine, AN AF Skourikhine, Alexei N. BE Kadar, I TI Proximity graph analysis for linear networks extraction from high-resolution satellite imagery - art. no. 62351C SO Signal Processing, Sensor Fusion, and Target Recognition XV SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Signal Processing, Sensor Fusion, and Target Recognition XV CY APR 17-19, 2006 CL Kissimmee, FL DE road network; satellite image; visual perception; minimum spanning tree; Delaunay triangulation; vector image; SVG ID ROAD EXTRACTION; TRANSFORM; AERIAL; GENIE AB Reliable and accurate methods for detection and extraction of linear network, such as road networks, in satellite imagery are essential to many applications. We present an approach to the road network extraction from high-resolution satellite imagery that is based on proximity graph analysis. We are jumping off from the classification provided by existing spectral and textural classification tools, which produce a set of candidate road patches. Then, constrained Delaunay triangulation and Chordal Axis transform are used to extract centerline characterization of the delineated candidate road patches. We refine produced center lines to reduce noise influence on patch boundaries, resulting in a smaller set of robust center lines authentically representing their road patches. Refined center lines are triangulated using constrained Delaunay triangulation (CDT) algorithm to generate a sub-optimal mesh of interconnections among them. The generated triangle edges connecting different center lines are used for spatial analysis of the center lines relations. A subset of the Delaunay tessellation grid contains the Euclidian Minimum Spanning Tree (EMST) that provides an approximation of road network. The approach can be generalized to the multi-criteria MST and multi-criteria shortest path algorithms to integrate other factors important for road network extraction, in addition to proximity relations considered by standard EMST. C1 Los Alamos Natl Lab, Space & Remote Sensing Sci Grp, Los Alamos, NM 87545 USA. RP Skourikhine, AN (reprint author), Los Alamos Natl Lab, Space & Remote Sensing Sci Grp, MS D436, Los Alamos, NM 87545 USA. OI Skurikhin, Alexei/0000-0001-5606-4933 NR 22 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 0-8194-6291-8 J9 P SOC PHOTO-OPT INS PY 2006 VL 6235 BP C2351 EP C2351 AR 62351C DI 10.1117/12.669536 PG 11 WC Computer Science, Artificial Intelligence; Remote Sensing; Imaging Science & Photographic Technology SC Computer Science; Remote Sensing; Imaging Science & Photographic Technology GA BEU87 UT WOS:000239564300047 ER PT S AU Volkman, DE AF Volkman, Douglas E. BE Lamond, JF Pielert, JH TI Concrete for Radiation Shielding SO SIGNIFICANCE OF TESTS AND PROPERTIES OF CONCRETE AND CONCRETE-MAKING MATERIALS SE American Society for Testing and Materials Special Technical Publications LA English DT Article; Book Chapter C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Volkman, DE (reprint author), Los Alamos Natl Lab, MS K718, Los Alamos, NM 87545 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU ASTM INTERNATIONAL PI WEST CONSHOHOCKEN PA 100 BARR HARBOR DRIVE, PO BOX C700, WEST CONSHOHOCKEN, PA 19428-2959 USA SN 1040-1695 BN 978-0-8031-3367-9 J9 AM SOC TEST MATER PY 2006 VL 169D BP 570 EP 577 DI 10.1520/STP37766S D2 10.1520/STP169D-EB PG 8 WC Construction & Building Technology; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Construction & Building Technology; Materials Science GA BZA87 UT WOS:000300952500048 ER PT S AU Pantelides, ST Wang, SW Franceschetti, A Buczko, R Di Ventra, M Rashkeev, SN Tsetseris, L Evans, MH Batyrev, IG Feldman, LC Dhar, S McDonald, K Weller, RA Schrimpf, RD Fleetwood, DM Zhou, XJ Williams, JR Tin, CC Chung, GY Isaacs-Smith, T Wang, SR Pennycook, SJ Duscher, G van Benthem, K Porter, LM AF Pantelides, Sokrates T. Wang, Sanwu Franceschetti, A. Buczko, R. Di Ventra, M. Rashkeev, S. N. Tsetseris, L. Evans, M. H. Batyrev, I. G. Feldman, L. C. Dhar, S. McDonald, K. Weller, R. A. Schrimpf, R. D. Fleetwood, D. M. Zhou, X. J. Williams, J. R. Tin, C. C. Chung, G. Y. Isaacs-Smith, T. Wang, S. R. Pennycook, S. J. Duscher, G. van Benthem, K. Porter, L. M. BE Devaty, RP TI Si/SiO2 and SiC/SiO2 interfaces for MOSFETs - Challenges and advances SO SILICON CARBIDE AND RELATED MATERIALS 2005, PTS 1 AND 2 SE Materials Science Forum LA English DT Proceedings Paper CT International Conference on Silicon Carbide and Related Materials (ICSCRM 2005) CY SEP 18-23, 2005 CL Pittsburgh, PA SP Aixtron, Cree Inc, Dow Corning, GE Global Res Ctr, II VI, Inc, Intrins Semicond, KLA Tencor, SiCED, SiCrystal AG DE Si/SiO2; SiC/SiO2; interface trap density; passivation; mobilities ID SILICON-CARBIDE; NITRIC-OXIDE; 4H-SIC MOSFETS; STATE DENSITY; OXIDATION; HYDROGEN; DEFECTS; TRAP; MOBILITY; SIO2 AB Silicon has been the semiconductor of choice for microelectronics largely because of the unique properties of its native oxide NOD and the Si/SiO2 interface. For high-temperature and/or high-power applications, however, one needs a semiconductor with a wider energy gap and higher thermal conductivity. Silicon carbide has the right properties and the same native oxide as Si. However, in the late 1990's it was found that the SiC/SiO2 interface had high interface trap densities, resulting in poor electron mobilities. Annealing in hydrogen, which is key to the quality of Si/SiO2 interfaces, proved ineffective. This paper presents a synthesis of theoretical and experimental work by the authors in the last six years and parallel work in the literature. High-quality SiC/SiO2 interfaces were achieved by annealing in NO gas and monatomic H. The key elements that lead to high-quality Si/SiO2 interfaces and low-quality SiC/SiO2 interfaces are identified and the role of N and H treatments is described. More specifically, optimal Si and SiC surfaces for oxidation are identified and the atomic-scale processes of oxidation and resulting interface defects are described. In the case of SiC, we conclude that excess carbon at the SiC/SiO2 interface leads to a bonded Si-C-O interlayer with a mix of fourfold- and threefold-coordinated C and Si atoms. The threefold coordinated atoms are responsible for the high interface trap density and can be eliminated either by H-passivation or replacement by N. Residual Si-Si bonds, which are partially passivated by H and N remain the main limitation. Perspectives for the future for both Si- and SiC-based MOSFETs are discussed. C1 Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA. Auburn Univ, Dept Phys, Auburn, AL 36849 USA. Carnegie Mellon Univ, Dept Mat Sci, Pittsburgh, PA 15213 USA. RP Pantelides, ST (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. EM pantelides@vanderbilt.edu RI Tin, Chin-Che/A-9122-2012; Duscher, Gerd/G-1730-2014; Di Ventra, Massimiliano/E-1667-2011 OI Duscher, Gerd/0000-0002-2039-548X; Di Ventra, Massimiliano/0000-0001-9416-189X NR 49 TC 32 Z9 33 U1 1 U2 7 PU TRANS TECH PUBLICATIONS LTD PI STAFA-ZURICH PA LAUBLSRUTISTR 24, CH-8717 STAFA-ZURICH, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2006 VL 527-529 BP 935 EP 948 PG 14 WC Materials Science, Multidisciplinary SC Materials Science GA BFS29 UT WOS:000244227200222 ER PT S AU Phlips, BF Hobart, KD Kub, FJ Stahlbush, RE Das, MK De Geronimo, G O'Connor, P AF Phlips, Bernard F. Hobart, Karl D. Kub, Francis J. Stahlbush, Robert E. Das, Mrinal K. De Geronimo, Gianluigi O'Connor, Paul BE Devaty, RP TI Silicon carbide power diodes as radiation detectors SO Silicon Carbide and Related Materials 2005, Pts 1 and 2 SE MATERIALS SCIENCE FORUM LA English DT Proceedings Paper CT International Conference on Silicon Carbide and Related Materials (ICSCRM 2005) CY SEP 18-23, 2005 CL Pittsburgh, PA SP Aixtron, Cree Inc, Dow Corning, GE Global Res Ctr, II VI, Inc, Intrins Semicond, KLA Tencor, SiCED, SiCrystal AG DE PiN diodes; sensor; radiation detector AB We have tested the radiation detection performance of Silicon Carbide (SiC) PIN diodes originally developed as high power diodes. These devices consist of 100 micron thick SiC grown epitaxially on SiC Substrates. The size and thickness of the devices make them appropriate for a number of radiation detection applications. We tested 0.25 cm2 and 0.5 cm2 devices and obtained X-ray spectra under illumination with an Am-241 radioactive Source. The spectra showed an energy resolution that was consistent with the resolution expected for the large capacitance of the device. Smaller devices with a diameter of I mm were also tested and produced spectra with a room temperature energy resolution of similar to 550 eV, which is consistent with the electronics limit for the capacitance of the small device, We measured the absolute charge generated by X-rays per KeV in SiC by comparing the charge generation with similar silicon devices and determined the energy required per electron hole pair in SiC to be 8.4 eV. We also performed radiation damage tests on these devices and found no significant loss in charge collection up to a photon dose of 100 MRad. Applications for these devices can be found in the fields of particle physics, nuclear physics, nuclear medicine, X-ray fluorescence, X-ray astronomy and X-ray navigation. C1 USN, Res Lab, Washington, DC 20375 USA. Cree Inc, Durham, NC 27703 USA. Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. RP Phlips, BF (reprint author), USN, Res Lab, 4555 Overlook Ave SW, Washington, DC 20375 USA. NR 6 TC 2 Z9 2 U1 0 U2 1 PU TRANS TECH PUBLICATIONS LTD PI STAFA-ZURICH PA LAUBLSRUTISTR 24, CH-8717 STAFA-ZURICH, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2006 VL 527-529 BP 1465 EP 1468 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA BFS29 UT WOS:000244227200347 ER PT S AU Bai, J Huang, X Raghothamachar, B Dudley, M Wagner, B Davis, RF Wu, L Zhu, Y AF Bai, J. Huang, X. Raghothamachar, B. Dudley, M. Wagner, B. Davis, R. F. Wu, L. Zhu, Y. BE Devaty, RP TI Strain relaxation in GaN/AlN films grown on vicinal and on-axis SiC substrates SO Silicon Carbide and Related Materials 2005, Pts 1 and 2 SE MATERIALS SCIENCE FORUM LA English DT Proceedings Paper CT International Conference on Silicon Carbide and Related Materials (ICSCRM 2005) CY SEP 18-23, 2005 CL Pittsburgh, PA SP Aixtron, Cree Inc, Dow Corning, GE Global Res Ctr, II VI, Inc, Intrins Semicond, KLA Tencor, SiCED, SiCrystal AG DE GaN; vicinal surface epitaxy; strain relaxation ID CHEMICAL-VAPOR-DEPOSITION; GAN; PHOTOLUMINESCENCE; SAPPHIRE AB Strain relaxation in the GaN/AlN/6H-SiC epitaxial system grown by vicinal surface epitaxy (VSE) is investigated and compared with that in on-axis epitaxy. High resolution x-ray diffraction (HRXRD) measurements show that GaN films grown by VSE have improved crystalline quality. High resolution transmission electron microscope (HRTEM) studies reveal that there are two types of misfit dislocations (MDs) at AlN/6H-SiC interfaces: 60 degrees complete dislocations along <11<(2)over bar>0> directions with Burgers vector 1/3<11<(2)over bar>0> and 60 degrees Shockley partials along <10<(1)over bar>0> directions with Burgers vector 1/3<10<(1)over bar>0>. The latter are usually geometrical partial misfit dislocations (GPMDs) that are dominant in VSE to accommodate the lattice mismatch and stacking sequence mismatch simultaneously. In VSE, it is the high-density GPMDs formed at the vicinal surface steps that facilitate rapid strain relaxation at the initial stage of deposition and hence lead to superior crystalline quality of the subsequently grown GaN films. C1 SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. N Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA. Brookhaven Natl Lab, Dept Mat Sci, Upton, NY 11973 USA. RP Bai, J (reprint author), SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. NR 9 TC 0 Z9 0 U1 0 U2 2 PU TRANS TECH PUBLICATIONS LTD PI STAFA-ZURICH PA LAUBLSRUTISTR 24, CH-8717 STAFA-ZURICH, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2006 VL 527-529 BP 1513 EP 1516 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA BFS29 UT WOS:000244227200358 ER PT J AU Tang, YR Perumalla, KS Fujimoto, RM Karimabadi, H Driscoll, J Omelchenko, Y AF Tang, Yarong Perumalla, Kalyan S. Fujimoto, Richard M. Karimabadi, Homa Driscoll, Jonathan Omelchenko, Yuri TI Optimistic simulations of physical systems using reverse computation SO SIMULATION-TRANSACTIONS OF THE SOCIETY FOR MODELING AND SIMULATION INTERNATIONAL LA English DT Article; Proceedings Paper CT 19th Workshop on Principles of Advanced and Distributed Simulation (PADS 2005) CY JUN 01-03, 2005 CL Monterey, CA SP ACM SIGSIM, IEEE Computer Soc, TCSIM, SCS DE parallel simulation; discrete event simulation; optimistic simulation; reverse computation; plasma simulation ID TIME; ENVIRONMENT AB Efficient computer simulation of complex physical phenomena has long been challenging due to their multiphysics and multiscale nature. In contrast to traditional time-stepped execution methods, the authors describe an approach using optimistic parallel discrete event simulation (PDES) and reverse computation techniques to execute plasma physics codes. They show that reverse computation-based optimistic parallel execution can significantly reduce the execution time of an example plasma simulation without requiring a significant amount of additional memory compared to conservative execution techniques. The authors describe an application-level reverse computation technique that is efficient and suitable for complex scientific simulations. C1 Georgia Inst Technol, Coll Comp, Atlanta, GA 30332 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. SciberQuest Inc, Solana Beach, CA 92075 USA. RP Tang, YR (reprint author), Georgia Inst Technol, Coll Comp, Atlanta, GA 30332 USA. EM yarongt@cc.gatech.edu OI Perumalla, Kalyan/0000-0002-7458-0832 NR 32 TC 8 Z9 8 U1 0 U2 1 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 0037-5497 EI 1741-3133 J9 SIMUL-T SOC MOD SIM JI Simul.-Trans. Soc. Model. Simul. Int. PD JAN PY 2006 VL 82 IS 1 BP 61 EP 73 DI 10.1177/0037549706065481 PG 13 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA 047KP UT WOS:000237878500005 ER PT S AU Wang, SQ Qureshi, N Lowther, MA Hawkins, AR Kwon, S Liddle, A Bokor, J Schmidt, H AF Wang, Suqin Qureshi, Naser Lowther, Mark A. Hawkins, Aaron R. Kwon, Sunghoon Liddle, Alexander Bokor, Jeffrey Schmidt, Holger GP IEEE TI Signal enhancement of time-resolved magneto-optic measurements on individual nanomagnets SO SIXTEENTH BIENNIAL UNIVERSITY/GOVERNMENT/INDUSTRY MICROELECTRONICS SYMPOSIUM, PROCEEDINGS SE PROCEEDINGS - UNIVERSITY/GOVERNMENT/INDUSTRY MICROELECTRONICS SYMPOSIUM LA English DT Proceedings Paper CT 16th Biennial University/Government/Industry Microelectronics Symposium CY JUN 25-28, 2006 CL San Jose State Univ, San Jose, CA SP SJSU Coll Engn, Opt Associates Incorp, Intel, Synopsys, Cadence Design Syst HO San Jose State Univ ID SINGLE-DOMAIN NANOMAGNETS AB The sensitivity of magneto-optic Kerr measurements of nanomagnetic structures is significantly improved using cavity enhancement to increase the Kerr signal by depositing dielectric layers on the magnetic surface under study. We discuss different strategies to optimize the use of cavity enhancement for observation of nanomagnets. We show that maximization of the Kerr rotation from magnetic structures results in higher sensitivity for magnetic films, but does not yield the highest sensitivity for nanomagnets. Instead, the use of an anti-reflection coating on the substrate surrounding the magnet in conjunction with index optimization of the enhancement layer can increase the Kerr signal by more than two orders of magnitude in the deep nanometer range, and enables detection of individual nanomagnets using conventional far-field Kerr microscopy. C1 [Wang, Suqin; Qureshi, Naser; Schmidt, Holger] Univ Calif Santa Cruz, Sch Engn, 1156 High St, Santa Cruz, CA 95064 USA. [Lowther, Mark A.; Hawkins, Aaron R.] Brigham Young Univ, ECEn Dept, Provo, UT 84602 USA. [Kwon, Sunghoon; Liddle, Alexander; Bokor, Jeffrey] Lawrence Berkeley Natl Lab, Mol Foundry, Berkeley, CA 94720 USA. RP Schmidt, H (reprint author), Univ Calif Santa Cruz, Sch Engn, 1156 High St, Santa Cruz, CA 95064 USA. EM hschmidt@soe.ucsc.edu RI Liddle, James/A-4867-2013 OI Liddle, James/0000-0002-2508-7910 FU National Science foundation [ECS-0245425, ECS-0216155]; Molecular Foundry at Lawrence Berkeley National Laboratory FX This work was supported by the National Science foundation under grants ECS-0245425 and ECS-0216155 and the Molecular Foundry at Lawrence Berkeley National Laboratory. NR 13 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0749-6877 BN 978-1-4244-0267-0 J9 P UNIV GOVT IND MICR PY 2006 BP 175 EP + PG 2 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology SC Engineering; Science & Technology - Other Topics GA BGO25 UT WOS:000248935100033 ER PT B AU Lee, J Lan, ZL Amundson, J Spentzouris, P AF Lee, Jungmin Lan, Zhiling Amundson, J. Spentzouris, P. BE Turner, SJ Lee, BS Cai, W TI Evaluating performance and scalability of advanced accelerator simulations SO SIXTH IEEE INTERNATIONAL SYMPOSIUM ON CLUSTER COMPUTING AND THE GRID: SPANNING THE WORLD AND BEYOND LA English DT Proceedings Paper CT 6th IEEE International Symposium on Cluster Computing and the Grid (CCGRID 2006) CY MAY 16-19, 2006 CL Singapore, SINGAPORE SP IEEE Comp Soc TCSC, ORACLE, HP, IBM, intel, Sun, Platform, PTC AB Advanced accelerator simulations have played a prominent role in the design and analysis of modem accelerators. Given that accelerator simulations are computational intensive and various high-end clusters are available for such simulations, it is imperative to study the performance and scalability of accelerator simulations on different production systems. In this paper, we examine the performance and scaling behavior of a DOE SciDAC funded accelerator simulation package called Synergia on three different TOP500 clusters including an IA32 Linux Cluster, an IA64 Linux Cluster, and a SGI Altix 3700 system. The main objective is to understand the impact of different high-end architectures and message layers on the performance of accelerator simulations. Experiments show that IA32 using single-CPU can provide the best performance and scalability, while SGI Altix and IA32 using dual-CPU do not scale past 128 and 256 CPUs respectively. Our analysis also indicates that the existing accelerator simulations have several performance bottlenecks which prevent accelerator simulations to take full advantage of the capabilities provided by teraflop and beyond systems. C1 [Lee, Jungmin; Lan, Zhiling] IIT, Dept Comp Sci, Chicago, IL 60616 USA. [Amundson, J.; Spentzouris, P.] Fermilab Natl Accelerator Lab, Chicago, IL 60616 USA. RP Lee, J (reprint author), IIT, Dept Comp Sci, Chicago, IL 60616 USA. EM leejung6@iit.edu; lan@iit.edu; amundson@fnal.gov; spentz@fnal.gov NR 10 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-2585-7 PY 2006 BP 209 EP + DI 10.1109/CIT.2006.139 PG 3 WC Computer Science, Theory & Methods SC Computer Science GA BEN60 UT WOS:000238329200029 ER PT B AU Foster, I Freeman, T Keahey, K Scheftner, D Sotomayor, B Zhang, X AF Foster, I. Freeman, T. Keahey, K. Scheftner, D. Sotomayor, B. Zhang, X. BE Turner, SJ Lee, BS Cai, W TI Virtual Clusters for Grid Communities SO SIXTH IEEE INTERNATIONAL SYMPOSIUM ON CLUSTER COMPUTING AND THE GRID: SPANNING THE WORLD AND BEYOND LA English DT Proceedings Paper CT 6th IEEE International Symposium on Cluster Computing and the Grid (CCGRID 2006) CY MAY 16-19, 2006 CL Singapore, SINGAPORE SP IEEE Comp Soc TCSC, ORACLE, HP, IBM, intel, Sun, Platform, PTC AB A challenging issue facing Grid communities is that while Grids can provide access to many heterogeneous resources, the resources to which access is provided often do not match the needs of a specific application or service. In an environment in which both resource availability and soft-ware requirements evolve rapidly, this disconnect can lead to resource underutilization, user frustration, and much wasted effort spent on bridging the gap between applications and resources. We show here how these issues can be overcome by allowing authorized Grid clients to negotiate the creation of virtual clusters made up of virtual machines configured to suit client requirements for software environment and hardware allocation. We introduce descriptions and methods that allow us to deploy flexibly configured virtual cluster workspaces. We describe their configuration, implementation, and evaluate them in the context of a virtual cluster representing the environment in production use by the Open Science Grid. Our performance evaluation results show that virtual clusters representing current Grid production environments can be deployed and managed efficiently, and thus can provide an acceptable platform for Grid applications. C1 [Freeman, T.; Scheftner, D.; Sotomayor, B.; Zhang, X.] Univ Chicago, Chicago, IL 60637 USA. [Foster, I.; Keahey, K.] Argonne Natl Lab, Argonne, IL 60439 USA. RP Foster, I (reprint author), Univ Chicago, Chicago, IL 60637 USA. EM foster@mcs.anl.gov; tfreeman@mcs.anl.gov; keahey@mcs.anl.gov; dscheftin@cs.uchicago.edu; borja@cs.uchicago.edu; hai@cs.uchicago.edu FU Mathematical, Information, and Computational Science Division FX This work was supported in part by the Mathematical, Information, and Computational Science Division. NR 28 TC 12 Z9 12 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-2585-7 PY 2006 BP 513 EP + PG 3 WC Computer Science, Theory & Methods SC Computer Science GA BEN60 UT WOS:000238329200075 ER PT B AU Buntinas, D Mercier, G Gropp, W AF Buntinas, Darius Mercier, Guillaume Gropp, William BE Turner, SJ Lee, BS Cai, W TI Design and Evaluation of Nemesis, a Scalable, Low-Latency, Message-Passing Communication Subsystem SO SIXTH IEEE INTERNATIONAL SYMPOSIUM ON CLUSTER COMPUTING AND THE GRID: SPANNING THE WORLD AND BEYOND LA English DT Proceedings Paper CT 6th IEEE International Symposium on Cluster Computing and the Grid (CCGRID 2006) CY MAY 16-19, 2006 CL Singapore, SINGAPORE SP IEEE Comp Soc TCSC, ORACLE, HP, IBM, intel, Sun, Platform, PTC AB This paper presents anew low-level communication subsystem called Nemesis. Nemesis has been designed and implemented to be scalable and efficient both in the intranode communication context using shared-memory and in the internode communication case using high-performance networks and is natively multimethod-enabled. Nemesis has been integrated in MPICH2 as a CH3 channel and delivers better Performance than other dedicated communication channels in MPICH2. Furthermore, the resulting MPICH2 architecture outperforms other MPI implementations in point-to-point benchmarks. C1 [Buntinas, Darius; Mercier, Guillaume; Gropp, William] Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Buntinas, D (reprint author), Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. EM buntinas@mcs.anl.gov; mercierg@mcs.anl.gov; gropp@mcs.anl.gov OI Gropp, William/0000-0003-2905-3029 FU Mathematical, Information, and Computational Sciences Division subprogram of the Office of Advanced Scientific Computing Research, Office of Science, U.S. Department of Energy [W-31-109-ENG-38] FX This work was supported by the Mathematical, Information, and Computational Sciences Division subprogram of the Office of Advanced Scientific Computing Research, Office of Science, U.S. Department of Energy, under Contract W-31-109-ENG-38. NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-2585-7 PY 2006 BP 521 EP + PG 2 WC Computer Science, Theory & Methods SC Computer Science GA BEN60 UT WOS:000238329200076 ER PT B AU Datta, P Sharma, S Feng, WC AF Datta, Pallab Sharma, Sushant Feng, Wu-Chun BE Turner, SJ Lee, BS Cai, W TI A feedback mechanism for network scheduling in LambdaGrids SO SIXTH IEEE INTERNATIONAL SYMPOSIUM ON CLUSTER COMPUTING AND THE GRID: SPANNING THE WORLD AND BEYOND LA English DT Proceedings Paper CT 6th IEEE International Symposium on Cluster Computing and the Grid (CCGRID 2006) CY MAY 16-19, 2006 CL Singapore, SINGAPORE SP IEEE Comp Soc TCSC, ORACLE, HP, IBM, intel, Sun, Platform, PTC AB Next-generation e-Science applications will require the ability to transfer information at high data rates between distributed computing centers and data repositories. A LambdaGrid offers dedicated, optical, circuit-switched, point-to-point connections, which may be reserved exclusively for an application. Though such dedicated high-speed connections eliminate congestion in the network, they effectively push the network congestion out to the end systems, as processing speeds have not kept up with networking speeds. Therefore, developing an efficient transport protocol over such highspeed dedicated circuits is of critical importance. In this work, we propose the idea of a lightweight end-system protocol, based on performance monitoring, to significantly improve the performance of data transport over a LambdaGrid. In particular we focus on dynamically monitoring the OS task scheduling at the receiving end-system so that potential end-system congestion may be detected early and appropriate feedback can be transmitted back to the sending end-system to avoid packet losses. One example of such an evasive action is to suspend transmission for a certain duration of time during which the OS on the receiving end-system must handle other computational processes. With this in mind, we propose to extend the Reliable-Blast UDP (RBUDP) protocol to take such evasive action by using a simple feedback mechanism that is activated via performance monitoring. The new protocol, named RBUDP+ dramatically improves the performance of data transfer over LambdaGrids. We demonstrate the effectiveness of our proposed protocol and illustrate the performance gains achieved via network emulation. C1 [Datta, Pallab; Sharma, Sushant] Los Alamos Natl Lab, Comp & Computat Sci Div, POB 1663, Los Alamos, NM 87545 USA. [Feng, Wu-Chun] Virginia Tech, Dept Comp Sci, Blacksburg, VA 24061 USA. RP Datta, P (reprint author), Los Alamos Natl Lab, Comp & Computat Sci Div, POB 1663, Los Alamos, NM 87545 USA. EM pallab@lanl.gov; sushant@lanl.gov; feng@cs.vt.edu NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-2585-7 PY 2006 BP 584 EP + PG 2 WC Computer Science, Theory & Methods SC Computer Science GA BEN60 UT WOS:000238329200085 ER PT B AU Fagan, M Hascoet, L Utke, J AF Fagan, Michael Hascoet, Laurent Utke, Jean BE DiPenta, M Moonen, L TI Data representation alternatives in semantically augmented numerical models SO SIXTH IEEE INTERNATIONAL WORKSHOP ON SOURCE CODE ANALYSIS AND MANIPULATION, PROCEEDINGS LA English DT Proceedings Paper CT 6th IEEE International Workshop on Source Code Analysis and Manipulation CY SEP 27-29, 2006 CL Philadelphia, PA SP IEEE Comp Soc TCSE, Kings Coll London, Anal, Slicing & Transformat Res Network, RainCode, Villanova Univ AB Transformations of numerical source code may require the augmentation of the original variables with new data to represent additional data the transformed program operates on. Automatic differentiation makes extensive use of this concept. We describe the two principal approaches to implement the variable augmentation, complete encapsulation and complete separation. The paper concentrates on two major aspects. First, we characterize the advantages of each approach and illustrate the effort needed to realize these advantages in Fortran, C, and C++ as the languages we are most interested in. Second, we discuss the practical solutions that in effect represent hybrids of the two approaches(1). C1 [Fagan, Michael] Rice Univ, 6100 Main St, Houston, TX 77005 USA. [Hascoet, Laurent] INRIA, F-06901 Sophia, France. [Utke, Jean] Argonne Natl Lab, Argonne, IL 60439 USA. RP Fagan, M (reprint author), Rice Univ, 6100 Main St, Houston, TX 77005 USA. EM mfagan@cs.rice.edu; laurent.hascoet@sophia.inria.fr; utke@mcs.anl.gov FU Mathematical, Information, and Computational Sciences Division subprogram of the Office of Advanced Scientific Computing Research, Office of Science; U.S. Department of Energy [W-31-109-ENG-38]; NSF under ITR [OCE-0205590] FX This work was supported by the Mathematical, Information, and Computational Sciences Division subprogram of the Office of Advanced Scientific Computing Research, Office of Science, U.S. Department of Energy, under Contract W-31-109-ENG-38 and by NSF under ITR contract OCE-0205590. NR 16 TC 2 Z9 2 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 978-0-7695-2353-8 PY 2006 BP 85 EP + PG 2 WC Computer Science, Software Engineering SC Computer Science GA BFU03 UT WOS:000244589600009 ER PT B AU Choudhari, M Fischer, P AF Choudhari, M Fischer, P BE Govindarajan, R TI Roughness induced transient growth: Nonlinear effects SO SIXTH IUTAM SYMPOSIUM ON LAMINAR-TURBULENT TRANSITION SE Fluid Mechanics and Its Applications LA English DT Proceedings Paper CT 6th IUTAM Symposium on Laminar-Turbulent Transition CY DEC 13-17, 2004 CL Bangalore, INDIA SP Int Union Theoret & Appl Mech ID PLATE BOUNDARY-LAYER; OPTIMAL DISTURBANCES; BYPASS TRANSITION; INSTABILITY AB Numerical simulations are used to model the disturbance field associated with a spanwise periodic array of circular disks in a laminar boundary layer. Besides capturing the major trends from the recent wind tunnel measurements by White and Ergin (2003), the simulations reveal the intricate effects of disturbance nonlinearity and roughness geometry on the transient growth characteristics in the wake of the roughness array and provide a numerical database for validating detailed features of optimal growth theory in the context of roughness induced stationary disturbances. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RP NASA, Langley Res Ctr, Hampton, VA 23681 USA. RI Choudhari, Meelan/F-6080-2017 OI Choudhari, Meelan/0000-0001-9120-7362 NR 15 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-3459-8 J9 FLUID MECH APPL PY 2006 VL 78 BP 237 EP + PG 2 WC Mechanics SC Mechanics GA BED95 UT WOS:000236905600031 ER PT J AU Hemraj-Benny, T Banerjee, S Sambasivan, S Balasubramanian, M Fischer, DA Eres, G Puretzky, AA Geohegan, DB Lowndes, DH Han, WQ Misewich, JA Wong, SS AF Hemraj-Benny, T Banerjee, S Sambasivan, S Balasubramanian, M Fischer, DA Eres, G Puretzky, AA Geohegan, DB Lowndes, DH Han, WQ Misewich, JA Wong, SS TI Near-edge X-ray absorption fine structure spectroscopy as a tool for investigating nanomaterials SO SMALL LA English DT Article DE carbon nanotubes; functionalization; nanomateriats; NEXAFS spectroscopy; surface analysis ID WALLED CARBON NANOTUBES; BORON-NITRIDE NANOTUBES; RAMAN-SPECTROSCOPY; SUBSTITUTION-REACTION; NEXAFS SPECTROSCOPY; SURFACE-CHEMISTRY; CHAIN-RELAXATION; FIELD-EMISSION; FIBERS; FUNCTIONALIZATION AB We have demonstrated near-edge X-ray absorption fine structure (NEXAFS) spectroscopy as a particularly useful and effective technique for simultaneously probing the surface chemistry, surface molecular orientation, degree of order, and electronic structure of carbon nanotubes and related nanomaterials. Specifically, we employ NEXAFS in the study of single-walled carbon nanotube and multi-walled carbon nanotube powders, films, and arrays, as well as of boron nitride nanotubes. We have focused on the advantages of NEXAFS as an exciting, complementary tool to conventional microscopy and spectroscopy for providing chemical and structural information about nanoscale samples. C1 SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. Natl Inst Stand & Technol, Mat Sci & Engn Lab, Gaithersburg, MD 20899 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Oak Ridge Natl Lab, Condensed Matter Phys Div, Oak Ridge, TN 37831 USA. Brookhaven Natl Lab, Ctr Funct Nanomat, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Mat Sci, Upton, NY 11973 USA. RP Wong, SS (reprint author), SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. EM sswong@notes.cc.sunysb.edu RI Han, WQ/E-2818-2013; Puretzky, Alexander/B-5567-2016; Geohegan, David/D-3599-2013; Eres, Gyula/C-4656-2017 OI Puretzky, Alexander/0000-0002-9996-4429; Geohegan, David/0000-0003-0273-3139; Eres, Gyula/0000-0003-2690-5214 NR 46 TC 83 Z9 84 U1 2 U2 31 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 1613-6810 J9 SMALL JI Small PD JAN PY 2006 VL 2 IS 1 BP 26 EP 35 DI 10.1002/smll.200500256 PG 10 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 996WH UT WOS:000234205600003 PM 17193550 ER PT J AU Chang, NA Richardson, JJ Clem, PG Hsu, JWP AF Chang, NA Richardson, JJ Clem, PG Hsu, JWP TI Additive Patterning of conductors and superconductors by solution stamping nanolithography SO SMALL LA English DT Article DE copper; oxides; printing; soft lithography; superconductors ID DIP-PEN NANOLITHOGRAPHY; THIN-FILMS; CAPILLARIES; FABRICATION; DEPOSITION; LAYERS C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Hsu, JWP (reprint author), Sandia Natl Labs, POB 5800,MS-1415, Albuquerque, NM 87185 USA. EM jwhsu@sandia.gov RI Richardson, Jacob/B-7535-2009 OI Richardson, Jacob/0000-0003-2733-9736 NR 18 TC 4 Z9 4 U1 0 U2 2 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 1613-6810 J9 SMALL JI Small PD JAN PY 2006 VL 2 IS 1 BP 75 EP 79 DI 10.1002/smll.200500264 PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 996WH UT WOS:000234205600011 PM 17193558 ER PT S AU Buechler, MA Leo, DJ AF Buechler, Miles A. Leo, Donald J. BE Lindner, DK TI Variational modeling of ionic polymer plate structures - art. no. 61660L SO Smart Structures and Materials 2006: Modeling, Signal Processing, and Control SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2006 Conference CY FEB 27-MAR 02, 2006 CL San Diego, CA SP SPIE, Amer Soc Mech Engineers, Intelligent Mat Forum, Jet Propuls Lab, Natl Sci Fdn DE ionomeric polymers; structural modeling; Hamilton's method ID LINEAR ELECTROMECHANICAL MODEL; TRANSDUCERS AB Ionomeric polymers are a promising class of intelligent material which exhibit electromechanical coupling similar to that of piezoelectric bimorphs. Ionomeric polymers are much more compliant than piezoelectric ceramics or polymers and have been shown to produce actuation strain on the order of 5% at operating voltages between I V and 5 V. This performance indicates the potential for self-actuating devices manufactured from ionomeric polymers, such as deformable mirrors or low pressure pump diaphragms. This paper presents a variational approach to the dynamic modeling of ionic polymer plates in rectangular coordinates. A linear matrix equation, which relates displacement and charge to applied forces and voltage, is developed to determine the response of the structure to applied forces and applied potentials. The modeling method is based on the incorporation of empirically determined material properties, which have been shown to be highly frequency dependent. The matrices are calculated at discrete frequencies and solved frequency-by-frequency to determine the response of the ionomeric plate structures. A model of a thin rectangular plate is developed and validated experimentally. Simulated frequency response functions are compared to experimental results for several locations on the plate. The response of the plate at certain frequencies is computed and compared to experimentally-determined response shapes. The results demonstrate the validity of the modeling approach in predicting the dynamic response of the ionomeric plate structure. These spatial solutions are also compared to experimentally determined response shapes. C1 Los Alamos Natl Lab, ESA, WR Weapon Response Grp, Div Engn & Appl Sci, Los Alamos, NM 87545 USA. RP Buechler, MA (reprint author), Los Alamos Natl Lab, ESA, WR Weapon Response Grp, Div Engn & Appl Sci, POB 1663, Los Alamos, NM 87545 USA. NR 8 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 0-8194-6219-5 J9 P SOC PHOTO-OPT INS PY 2006 VL 6166 BP L1660 EP L1660 AR 61660L DI 10.1117/12.659361 PG 12 WC Automation & Control Systems; Engineering, Electrical & Electronic; Instruments & Instrumentation; Materials Science, Multidisciplinary SC Automation & Control Systems; Engineering; Instruments & Instrumentation; Materials Science GA BEO48 UT WOS:000238444300018 ER PT S AU Goddard, G Whittier, JE AF Goddard, Gregory Whittier, Jennifer E. BE Varadan, VK TI Biomolecules as nanomaterials: interface characterization for sensor development - art. no. 617206 SO Smart Structures and Materials 2006: Smart Electronics, Mems, Biomems, and Nanotechnology SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2006 Conference CY FEB 27-MAR 02, 2006 CL San Diego, CA SP SPIE, Amer Soc Mech Engineers, Intelligent Mat Forum, Jet Propuls Lab, Natl Sci Fdn DE impedance spectroscopy; microtubules; MAPs; biomolecular sensors ID IMPEDANCE SPECTROSCOPY; NANOFIBER SCAFFOLD; MAGNETIC-FIELDS; MICROTUBULES; TUBULIN; DENDRITES; BEHAVIOR; AXONS; MAP2; TAU AB Extensive research is underway to understand and exploit the interface between biological materials and integrated systems Today, "nanotechnology" can be defined as a group of emerging technologies in which the structure of matter is controlled at the nanometer scale, the scale of small numbers of atoms, to produce novel materials and devices having useful and unique properties. An ideal biological candidate for use in nanoscale devices is the microtubule, an essential component of the eukaryotic cytoskeleton, which, unlike most proteins, has been shown to be electrically conductive. Due to the presence of an intrinsic dipole in the protein polymer, RF reflectance spectroscopy was chosen as an interrogation method. RF reflectance spectroscopy measures the electrical response of a sample in response to sinusoidally alternating currents as a function of frequency By interrogating the protein electrically, we are able to detect the polymerization state of the system, track any associated conductivity changes, and monitor binding of microtubule-associated proteins. We demonstrate manipulation of the microtubule system through the use of low-frequency electric fields, and discuss implications for sensor development. C1 Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. RP Goddard, G (reprint author), Los Alamos Natl Lab, Biosci Div, Mail Stop M888, Los Alamos, NM 87545 USA. NR 33 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 0-8194-6225-X J9 P SOC PHOTO-OPT INS PY 2006 VL 6172 BP 17206 EP 17206 AR 617206 DI 10.1117/12.658771 PG 12 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Telecommunications SC Engineering; Science & Technology - Other Topics; Telecommunications GA BEO54 UT WOS:000238450100005 ER PT S AU El-Kady, I Su, MF Verley, JC Taha, MMR Khraishi, T AF El-Kady, I. Su, M. F. Verley, J. C. Taha, M. M. Reda Khraishi, T. BE Varadan, VK TI Photonic crystal sensor systems for sub-micron damage detection, quantification, and diagnosis - art. no. 61720V SO Smart Structures and Materials 2006: Smart Electronics, Mems, Biomems, and Nanotechnology SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2006 Conference CY FEB 27-MAR 02, 2006 CL San Diego, CA SP SPIE, Amer Soc Mech Engineers, Intelligent Mat Forum, Jet Propuls Lab, Natl Sci Fdn DE nano photonic sensors; photonic bandgap; damage diagnosis; finite difference time domain ID GREENS-FUNCTIONS; BAND-STRUCTURES; COEFFICIENTS; PROGRAM AB Photonic crystals (PC) are artificially fabricated crystals with a periodicity in the dielectric function. These crystals have the novel ability to mold and control light in three dimensions by opening a frequency region (bandgap) in which light is forbidden to propagate. We demonstrate using a simulation model that a photonic crystal sensor attached to a. composite substrate will experience a significant change in its bandgap profile when damage is induced in the composite substrate. The frequency response of the photonic crystal sensor is modeled using the finite difference time domain (FDTD) method. A damage metric using principles of fuzzy pattern recognition is developed to evaluate and quantify the change in the frequency response in relation to the induced damage. Results for different damage scenarios are examined and reported with significantly high success rate. Successful developments of photonic crystal sensors will allow damage identification at scales not attainable using current sensing technologies. C1 Sandia Natl Labs, Photon Microsyst Technol Dept, Albuquerque, NM 87185 USA. RP El-Kady, I (reprint author), Sandia Natl Labs, Photon Microsyst Technol Dept, POB 5800, Albuquerque, NM 87185 USA. RI El-Kady, Ihab/D-2886-2013; Verley, Jason/C-2026-2008 OI El-Kady, Ihab/0000-0001-7417-9814; Verley, Jason/0000-0003-2184-677X NR 14 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 0-8194-6225-X J9 P SOC PHOTO-OPT INS PY 2006 VL 6172 BP V1720 EP V1720 AR 61720V DI 10.1117/12.658578 PG 7 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Telecommunications SC Engineering; Science & Technology - Other Topics; Telecommunications GA BEO54 UT WOS:000238450100026 ER PT S AU Park, G Farrar, CR di Scalea, FL Coccia, S AF Park, Gyuhae Farrar, Charles R. di Scalea, Francesco Lanza Coccia, Stefano BE Matsuzaki, Y TI Self-diagnosis and validation of active sensors used for structural health monitoring - art. no. 61731N SO Smart Structures and Materials 2006: Smart Structures and Integrated Systems SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2006 Conference CY FEB 27-MAR 02, 2006 CL San Diego, CA SP SPIE, Amer Soc Mech Engineers, Intelligent Mat Forum, Jet Propuls Lab, Natl Sci Fdn AB This paper presents a self-diagnostic and sensor validation procedure that performs in-situ monitoring of the operational status of piezoelectric (PZT) sensors and actuators used in structural health monitoring (SHM) applications. The sensor/actuator self-diagnostic procedure, where the sensors/actuators are confirmed to be functioning properly during operation, is a critical component to successfully complete the SHM process with large numbers of active sensors typically deployed in a structure. Both degradation of the mechanical/electrical properties of a PZT transducer and the bonding defects between a PZT patch and a host structure could be identified using the proposed procedure. First, the effects of bonding defects between a PZT patch and a host structure on high frequency SHM techniques, including Lamb wave propagations and impedance methods, have been experimentally investigated. It has been found that the effects are remarkable, modifying wave phase and amplitude, creating new wave modes, and changing measured impedance spectrum. These changes can lead to the false indications on structural conditions without an efficient sensor-diagnostic procedure. The feasibility of the proposed sensor diagnostics procedure was then demonstrated by analytical studies and experimental examples, where the functionality of surface-mounted piezoelectric sensors was continuously deteriorated. The proposed procedure can provide a metric that can be used to determine the sensor functionality over a long period of service time or after an extreme loading event. Further, the proposed procedure can be useful if one needs to check the operational status of a sensing network right after its installation. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Park, G (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Farrar, Charles/C-6954-2012; OI Farrar, Charles/0000-0001-6533-6996 NR 11 TC 1 Z9 1 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 0-8194-6226-8 J9 P SOC PHOTO-OPT INS PY 2006 VL 6173 BP N1731 EP N1731 AR 61731N DI 10.1117/12.658813 PG 9 WC Automation & Control Systems; Instruments & Instrumentation; Materials Science, Multidisciplinary SC Automation & Control Systems; Instruments & Instrumentation; Materials Science GA BEO55 UT WOS:000238450200048 ER PT B AU Cui, X Potok, TE AF Cui, Xiaohui Potok, Thomas E. GP IEEE BE Song, YT Lu, C TI A distributed flocking approach for information stream clustering analysis SO SNPD 2006: SEVENTH ACIS INTERNATIONAL CONFERENCE ON SOFTWARE ENGINEERING ARTIFICIAL INTELLIGENCE, NETWORKING, AND PARALLEL/DISTRIBUTED COMPUTING, PROCEEDINGS LA English DT Proceedings Paper CT 7th ACIS International Conference on Software Engineering, Artificial Intelligence, Networking, and Parallel and Distributed Computing/7th ACIS International Workshop on Self-Assembling Networks CY JUN 19-20, 2006 CL Las Vegas, NV SP Int Assoc Comp & Informat Sci, Towson Univ, Cent Michigan Univ AB Intelligence analysts are currently overwhelmed with the amount of information streams generated everyday. There is a lack of comprehensive tool that can real-time analyze the information streams. Document clustering analysis plays an important role in improving the accuracy of information retrieval. However, most clustering technologies can only be applied for analyzing the static document collection because they normally require a large amount of computation resource and long time to get accurate result. It is very difficult to cluster a dynamic changed text information streams on an individual computer. Our early research has resulted in a dynamic reactive flock clustering algorithm which can continually refine the clustering result and quickly react to the change of document contents. This character makes the algorithm suitable for cluster analyzing dynamic changed document information, such as text information stream. Because of the decentralized character of this algorithm, a distributed approach is a very natural way to increase the clustering speed of the algorithm. In this paper, we present a distributed multi-agent flocking approach for the text information stream clustering and discuss the decentralized architectures and communication schemes for load balance and status information synchronization in this approach. C1 [Cui, Xiaohui; Potok, Thomas E.] Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. RP Cui, X (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. EM Cuix@ornl.gov; potokte@ornl.gov OI Potok, Thomas/0000-0001-6687-3435 NR 17 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-2611-X PY 2006 BP 97 EP + PG 2 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Computer Science, Software Engineering; Computer Science, Theory & Methods; Telecommunications SC Computer Science; Telecommunications GA BEQ48 UT WOS:000238913400015 ER PT B AU Kong, P AF Kong, Peter BE Kongoli, F Reddy, RG TI Atmospheric-pressure plasma process and applications SO Sohn International Symposium Advanced Processing of Metals and Materials, Vol 6: NEW, IMPROVED AND EXISTING TECHNOLOGIES: AQUEOUS AND ELECTROCHEMICAL PROCESSING LA English DT Proceedings Paper CT Sohn International Symposium on Advanced Processing of Metals and Materials CY AUG 27-31, 2006 CL San Diego, CA SP Minerals, Met & Mat Soc, Acad Mexicana Ciencias Mat, Amer Foundry Soc, Amer Inst Chem Engineers, APMI Int, ASM Int, Asociac Argentina Mat, Assoc Iron & Steel Technol, Assoc Italiana Met, Australasian Inst Min & Met, Austrian Soc Met & Mat, Beijing Gen Res Inst Min & Met, Benelux Met, Brazilian Assoc Mat & Met, Brunei Darussalam Inst Chem, Ceram Soc Japan, Chem Soc Japan, Chem Soc Pakistan, Chem Soc Peru, Chilean Chem Soc, Chinese Soc Met, Cobalt Dev Inst, Colegio Ingenieros Chile, CSIRO, Czech Soc New Mat & Technologies, Danish Ceram Soc, Danish Chem Soc, Danish Met Soc, Electrochem Soc, Electrochem Soc Japan, Engn Conf Int, Eurometaux, European Ceram Soc, Federat European Mat Soc, Georgian Ceram Soc, German Soc Min, Met, Resource & Environm Technol, Gintsvetmet Inst, Gipronickel Inst, JS, Hellen Ceram Soc, Indian Inst Met, Inst Nonferrous & Rare Met, Inst Mat Engn Australasian, Inst Mat, Minerals & Min, Inst Met & Technol, Inst NonFerrous Met, Inst Argentino Siderurgia, Integrated Chemists Philippines, Int Aluminium Inst, Int Energy Fdn, Int Lead Zinc Res Org Inc, Iron & Steel Inst Japan, Israel Chem Soc, Japan Inst Met, Jordanian Chem Soc, Korean Acad Sci & Technol, Korean Chem Soc, Korean Inst Chem Engineers, Korean Inst Met & Mat, Malaysian Inst Chem, Mat Res Soc, Mat Soc Portugal, Met Sco CIM, Min Engn Int, Min & Mat Proc Inst Japan, Nonferrous Met Soc China, N Amer Thermal Anal Soc, Polish Assoc Met Engineers & Technicians, Portugese Chem Soc, Slovak Met Soc, Slovenian Ceram Soc, Slovenian Soc Mat, Soc Francaise Chimie, Soc Francaise Met & Mat, Soc Royal Chimie, Soc Min, Met & Explorat, Soc Chem Engn Japan, S African Inst Min & Met, Swedish Soc Mat Technol, Swedish Steel Producers Assoc, Technol Inst VZW, Amer Ceram Soc, Chem Soc Thailand, Finnish Assoc Min & Met Engineers, Canadian Min Journal, Ferrous Met Journal, Ind Minerals, Journal Tech Elect Mat, Magnesium Monthly Review, Mat Engn News, Mineral & Met Proc, Mineral Proc Journal, Min Journal, Nonferrous Met Journal, Ore & Met Publishing House, European Journal Min Proc & Environm Protect, Ausmelt, FLOGEN Technologies Inc, Korea Inst Geosci & Mineral Resources, Korea Zinc Co Ltd, LS Nikko Copper, Outokumpu Technol, Posco, Umicore Precious Met Refining, Xstrata Technol DE plasma; process; applications ID NONTHERMAL PLASMA; THERMAL PLASMA; WASTE AB This paper provides a general discussion of atmospheric-pressure plasma generation, processes, and applications. There are two distinct categories of atmospheric-pressure plasmas: thermal and nonthermal. Thermal atmospheric-pressure plasmas include those produced in high intensity arcs, plasma torches, or in high intensity, high frequency discharges. Although nonthermal plasmas are at room temperatures, they are extremely effective in producing activated species, e.g., free radicals and excited state atoms. Thus, both thermal and nonthermal atmospheric-pressure plasmas are finding applications in a wide variety of industrial processes, e.g. waste destruction, material recovery, extractive metallurgy, powder synthesis, and energy conversion. A brief discussion of recent plasma technology research and development activities at the Idaho National Laboratory is included. C1 Idaho Natl Lab, Idaho Falls, ID 83415 USA. RP Kong, P (reprint author), Idaho Natl Lab, POB 1625, Idaho Falls, ID 83415 USA. NR 32 TC 0 Z9 0 U1 2 U2 3 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-639-1 PY 2006 BP 493 EP 506 PG 14 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BFG86 UT WOS:000241810100044 ER PT B AU Canty, JM Mink, L AF Canty, J. Michael Mink, Leland Roy BE Kongoli, F Reddy, RG TI Geothermal mineral recovery SO Sohn International Symposium Advanced Processing of Metals and Materials, Vol 6: NEW, IMPROVED AND EXISTING TECHNOLOGIES: AQUEOUS AND ELECTROCHEMICAL PROCESSING LA English DT Proceedings Paper CT Sohn International Symposium on Advanced Processing of Metals and Materials CY AUG 27-31, 2006 CL San Diego, CA SP Minerals, Met & Mat Soc, Acad Mexicana Ciencias Mat, Amer Foundry Soc, Amer Inst Chem Engineers, APMI Int, ASM Int, Asociac Argentina Mat, Assoc Iron & Steel Technol, Assoc Italiana Met, Australasian Inst Min & Met, Austrian Soc Met & Mat, Beijing Gen Res Inst Min & Met, Benelux Met, Brazilian Assoc Mat & Met, Brunei Darussalam Inst Chem, Ceram Soc Japan, Chem Soc Japan, Chem Soc Pakistan, Chem Soc Peru, Chilean Chem Soc, Chinese Soc Met, Cobalt Dev Inst, Colegio Ingenieros Chile, CSIRO, Czech Soc New Mat & Technologies, Danish Ceram Soc, Danish Chem Soc, Danish Met Soc, Electrochem Soc, Electrochem Soc Japan, Engn Conf Int, Eurometaux, European Ceram Soc, Federat European Mat Soc, Georgian Ceram Soc, German Soc Min, Met, Resource & Environm Technol, Gintsvetmet Inst, Gipronickel Inst, JS, Hellen Ceram Soc, Indian Inst Met, Inst Nonferrous & Rare Met, Inst Mat Engn Australasian, Inst Mat, Minerals & Min, Inst Met & Technol, Inst NonFerrous Met, Inst Argentino Siderurgia, Integrated Chemists Philippines, Int Aluminium Inst, Int Energy Fdn, Int Lead Zinc Res Org Inc, Iron & Steel Inst Japan, Israel Chem Soc, Japan Inst Met, Jordanian Chem Soc, Korean Acad Sci & Technol, Korean Chem Soc, Korean Inst Chem Engineers, Korean Inst Met & Mat, Malaysian Inst Chem, Mat Res Soc, Mat Soc Portugal, Met Sco CIM, Min Engn Int, Min & Mat Proc Inst Japan, Nonferrous Met Soc China, N Amer Thermal Anal Soc, Polish Assoc Met Engineers & Technicians, Portugese Chem Soc, Slovak Met Soc, Slovenian Ceram Soc, Slovenian Soc Mat, Soc Francaise Chimie, Soc Francaise Met & Mat, Soc Royal Chimie, Soc Min, Met & Explorat, Soc Chem Engn Japan, S African Inst Min & Met, Swedish Soc Mat Technol, Swedish Steel Producers Assoc, Technol Inst VZW, Amer Ceram Soc, Chem Soc Thailand, Finnish Assoc Min & Met Engineers, Canadian Min Journal, Ferrous Met Journal, Ind Minerals, Journal Tech Elect Mat, Magnesium Monthly Review, Mat Engn News, Mineral & Met Proc, Mineral Proc Journal, Min Journal, Nonferrous Met Journal, Ore & Met Publishing House, European Journal Min Proc & Environm Protect, Ausmelt, FLOGEN Technologies Inc, Korea Inst Geosci & Mineral Resources, Korea Zinc Co Ltd, LS Nikko Copper, Outokumpu Technol, Posco, Umicore Precious Met Refining, Xstrata Technol AB Over 25 years of US research in Mineral Recovery from Geothermal Solutions have lead to few commercial applications. With the World Bank program in Kamchatka, Russia in September 2005 a step was taken to vitalize and coordinate the many efforts to advance economic mineral recovery systems worldwide. The US Department of Energy is helping to spur on the interest and research needed to realize the many benefits of extracting minerals from geothermal solutions. The excitement of recovery of minerals from geothermal brines has many positive angles. The economics of certain geothermal site is improved if a revenue is arrived from a sellable commodity with the geothermal power. The use of cleaner geothermal brines also improves the capable use of the brine before reinjection. We will review the history of Geothermal in the USA and the opportunities for recovery of different minerals and the markets for them. C1 US DOE, Washington, DC 20585 USA. RP Canty, JM (reprint author), US DOE, 1000 Independence Ave SW, Washington, DC 20585 USA. NR 0 TC 0 Z9 0 U1 0 U2 3 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-639-1 PY 2006 BP 547 EP 551 PG 5 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BFG86 UT WOS:000241810100048 ER PT B AU Bourcier, W Bruton, C Burton, E Ralph, B Johnson, M Nix, G AF Bourcier, William Bruton, Carol Burton, Elizabeth Ralph, Bill Johnson, Mackenzie Nix, Gerald BE Kongoli, F Reddy, RG TI Co-production of silica and other commodities from geothermal fluids SO Sohn International Symposium Advanced Processing of Metals and Materials, Vol 6: NEW, IMPROVED AND EXISTING TECHNOLOGIES: AQUEOUS AND ELECTROCHEMICAL PROCESSING LA English DT Proceedings Paper CT Sohn International Symposium on Advanced Processing of Metals and Materials CY AUG 27-31, 2006 CL San Diego, CA SP Minerals, Met & Mat Soc, Acad Mexicana Ciencias Mat, Amer Foundry Soc, Amer Inst Chem Engineers, APMI Int, ASM Int, Asociac Argentina Mat, Assoc Iron & Steel Technol, Assoc Italiana Met, Australasian Inst Min & Met, Austrian Soc Met & Mat, Beijing Gen Res Inst Min & Met, Benelux Met, Brazilian Assoc Mat & Met, Brunei Darussalam Inst Chem, Ceram Soc Japan, Chem Soc Japan, Chem Soc Pakistan, Chem Soc Peru, Chilean Chem Soc, Chinese Soc Met, Cobalt Dev Inst, Colegio Ingenieros Chile, CSIRO, Czech Soc New Mat & Technologies, Danish Ceram Soc, Danish Chem Soc, Danish Met Soc, Electrochem Soc, Electrochem Soc Japan, Engn Conf Int, Eurometaux, European Ceram Soc, Federat European Mat Soc, Georgian Ceram Soc, German Soc Min, Met, Resource & Environm Technol, Gintsvetmet Inst, Gipronickel Inst, JS, Hellen Ceram Soc, Indian Inst Met, Inst Nonferrous & Rare Met, Inst Mat Engn Australasian, Inst Mat, Minerals & Min, Inst Met & Technol, Inst NonFerrous Met, Inst Argentino Siderurgia, Integrated Chemists Philippines, Int Aluminium Inst, Int Energy Fdn, Int Lead Zinc Res Org Inc, Iron & Steel Inst Japan, Israel Chem Soc, Japan Inst Met, Jordanian Chem Soc, Korean Acad Sci & Technol, Korean Chem Soc, Korean Inst Chem Engineers, Korean Inst Met & Mat, Malaysian Inst Chem, Mat Res Soc, Mat Soc Portugal, Met Sco CIM, Min Engn Int, Min & Mat Proc Inst Japan, Nonferrous Met Soc China, N Amer Thermal Anal Soc, Polish Assoc Met Engineers & Technicians, Portugese Chem Soc, Slovak Met Soc, Slovenian Ceram Soc, Slovenian Soc Mat, Soc Francaise Chimie, Soc Francaise Met & Mat, Soc Royal Chimie, Soc Min, Met & Explorat, Soc Chem Engn Japan, S African Inst Min & Met, Swedish Soc Mat Technol, Swedish Steel Producers Assoc, Technol Inst VZW, Amer Ceram Soc, Chem Soc Thailand, Finnish Assoc Min & Met Engineers, Canadian Min Journal, Ferrous Met Journal, Ind Minerals, Journal Tech Elect Mat, Magnesium Monthly Review, Mat Engn News, Mineral & Met Proc, Mineral Proc Journal, Min Journal, Nonferrous Met Journal, Ore & Met Publishing House, European Journal Min Proc & Environm Protect, Ausmelt, FLOGEN Technologies Inc, Korea Inst Geosci & Mineral Resources, Korea Zinc Co Ltd, LS Nikko Copper, Outokumpu Technol, Posco, Umicore Precious Met Refining, Xstrata Technol DE silica; zinc; lithium; geothermal; solution mining AB Geothermal Brines are a significant potential source of valuable minerals and metals. These brines are water that is heated by the natural heat flow from the depths of the earth. Hotter brines, typically with temperatures greater than 120 degrees C, are used to generate electricity. Lower temperature brines are directly used to supply thermal energy to applications such as agriculture, aquaculture and process/domestic heat. The geothermal waters have had intimate and lengthy contact with the layers of the earth's crust that they flow through, resulting in dissolution of minerals and metals from the rocks, and solution into the hot water. These aqueous solutions can be processed to recover minerals and metals. Some potential products include silica, zinc and lithium, along with other materials. Recovery of minerals and metals from geothermal brines can be viewed as "solution mining by nature", followed by application of known or new hydrometallurgical techniques for isolation and purification. This paper discusses the opportunities, the processes, the challenges, the current status, the economics and the potential for recovery of minerals and metals from geothermal brines. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Bourcier, W (reprint author), Lawrence Livermore Natl Lab, POB 5508, Livermore, CA 94550 USA. NR 16 TC 0 Z9 0 U1 1 U2 9 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-639-1 PY 2006 BP 559 EP 569 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BFG86 UT WOS:000241810100050 ER PT B AU Melgaard, DK Beaman, JJ Shelmidine, G AF Melgaard, David K. Beaman, Joseph J. Shelmidine, Gregory BE Kongoli, F Reddy, RG TI Model-based electroslag remelting control for simultaneous, consistent and responsive melt rate and immersion depth control SO Sohn International Symposium Advanced Processing of Metals and Materials, Vol 7: INDUSTRIAL PRACTICE LA English DT Proceedings Paper CT Sohn International Symposium on Advanced Processing of Metals and Materials CY AUG 27-31, 2006 CL San Diego, CA SP Minerals, Met & Mat Soc, Acad Mexicana Ciencias Mat, Amer Foundry Soc, Amer Inst Chem Engineers, APMI Int, ASM Int, Asociac Argentina Mat, Assoc Iron & Steel Technol, Assoc Italiana Met, Australasian Inst Min & Met, Austrian Soc Met & Mat, Beijing Gen Res Inst Min & Met, Benelux Met, Brazilian Assoc Mat & Met, Brunei Darussalam Inst Chem, Ceram Soc Japan, Chem Soc Japan, Chem Soc Pakistan, Chem Soc Peru, Chilean Chem Soc, Chinese Soc Met, Cobalt Dev Inst, Colegio Ingenieros Chile, CSIRO, Czech Soc New Mat & Technologies, Danish Ceram Soc, Danish Chem Soc, Danish Met Soc, Electrochem Soc, Electrochem Soc Japan, Engn Conf Int, Eurometaux, European Ceram Soc, Federat European Mat Soc, Georgian Ceram Soc, German Soc Min, Met, Resource & Environm Technol, Gintsvetmet Inst, Gipronickel Inst, JS, Hellen Ceram Soc, Indian Inst Met, Inst Nonferrous & Rare Met, Inst Mat Engn Australasian, Inst Mat, Minerals & Min, Inst Met & Technol, Inst NonFerrous Met, Inst Argentino Siderurgia, Integrated Chemists Philippines, Int Aluminium Inst, Int Energy Fdn, Int Lead Zinc Res Org Inc, Iron & Steel Inst Japan, Israel Chem Soc, Japan Inst Met, Jordanian Chem Soc, Korean Acad Sci & Technol, Korean Chem Soc, Korean Inst Chem Engineers, Korean Inst Met & Mat, Malaysian Inst Chem, Mat Res Soc, Mat Soc Portugal, Met Sco CIM, Min Engn Int, Min & Mat Proc Inst Japan, Nonferrous Met Soc China, N Amer Thermal Anal Soc, Polish Assoc Met Engineers & Technicians, Portugese Chem Soc, Slovak Met Soc, Slovenian Ceram Soc, Slovenian Soc Mat, Soc Francaise Chimie, Soc Francaise Met & Mat, Soc Royal Chimie, Soc Min, Met & Explorat, Soc Chem Engn Japan, S African Inst Min & Met, Swedish Soc Mat Technol, Swedish Steel Producers Assoc, Technol Inst VZW, Amer Ceram Soc, Chem Soc Thailand, Finnish Assoc Min & Met Engineers, Canadian Min Journal, Ferrous Met Journal, Ind Minerals, Journal Tech Elect Mat, Magnesium Monthly Review, Mat Engn News, Mineral & Met Proc, Mineral Proc Journal, Min Journal, Nonferrous Met Journal, Ore & Met Publishing House, European Journal Min Proc & Environm Protect, Ausmelt, FLOGEN Technologies Inc, Korea Inst Geosci & Mineral Resources, Korea Zinc Co Ltd, LS Nikko Copper, Outokumpu Technol, Posco, Umicore Precious Met Refining, Xstrata Technol DE model-based control; electroslag remelting; process control AB Electroslag Remelting (ESR) is a complex process used to produce high quality specialty alloy materials. The quality can be directly correlated to variances in melt rate and immersion depth. Conventional ESR furnaces control these quantities using two independent control loops using proportional changes in current for melt rate and driving the electrode up and down to match a voltage set point for immersion depth. However it is well known that the control loops are highly coupled, i.e. changing the current to account for melt rate deviations changes the voltage depth relationship and vice verse. In addition the noise in measurements of the ESR process can be considerable, forcing conventional controllers to use highly damped responses. A new model-based controller has been developed to embody the coupling and improve responsiveness by using estimates from a reduced-order linear ESR model and the typical process measurements to control melt rate and immersion depth simultaneously. Kalman filtering is used to optimally combine the model estimates of eight process states and the measurements of voltage, current, position and mass to estimate the instantaneous melt rate and immersion depth. Several ESR melts under steady state and transient conditions were conducted to evaluate the performance of the new controller. This paper will discuss the design of the new ESR model and controller and will present experimental results demonstrating its much improved control and responsiveness. While this controller was developed for the ESR process, the effectiveness of model-based control in managing such a complex process with relatively simple equations suggests the approach could be employed for many other processes as well. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Melgaard, DK (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 7 TC 4 Z9 4 U1 1 U2 1 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-640-5 PY 2006 BP 435 EP 449 PG 15 WC Engineering, Industrial; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Engineering; Materials Science; Metallurgy & Metallurgical Engineering GA BFG93 UT WOS:000241814600036 ER PT J AU Blanco-Canqui, H Lal, R Post, WM Izaurralde, RC Owens, LB AF Blanco-Canqui, H Lal, R Post, WM Izaurralde, RC Owens, LB TI Corn stover impacts on near-surface soil properties of no-till corn in Ohio SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article ID CROP RESIDUE MANAGEMENT; PHYSICAL-PROPERTIES; PENETRATION RESISTANCE; PEDOTRANSFER FUNCTIONS; ORGANIC-MATTER; BULK-DENSITY; CONE INDEX; REMOVAL; INFILTRATION; STRENGTH AB Corn (Zea mays L.) stover is a primary biofuel feedstock and its expanded use could help reduce reliance on fossil fuels and net CO2 emissions. Excessive stover removal may, however, negatively impact near-surface soil properties within a short period after removal. We assessed changes in soil crust strength, bulk density (rho(b)), and water content over a 1-yr period following a systematic removal or addition of stover from three no-till soils under corn in Ohio. Soils from ongoing experiments at the North Appalachian, Experimental Watershed (NAEW), Western Agricultural Experiment Station (WAES), and Northwestern Agricultural Experiment Station (NWAES) of Ohio Agricultural Research and Development Center (OARDC) were studied. Six stover treatments of 0 (TO), 25 (T25), 50 (T50), 75 (T75), 100 (T100), and 200 (T200)% were imposed on 3 by 3 m plots corresponding to 0, 1.25, 2.50, 3.75, 5.00, and 10.00 Mg ha(-1) of stover, respectively. Cone index (CI), shear strength (SHEAR), rho(b), and volumetric water content (theta(v)) were measured monthly from June through December 2004 and in May 2005. Effects of stover removal on increasing Cl and SHEAR were soil-specific. Stover removal consistently increased rho(b) and decreased 0, across soils (P < 0.01). Compared with the normal stover treatment (T100), doubling the amount of stover (T200) did not significantly affect soil properties except 0, where, after 1 yr, T200 increased 0, by 1.3 to 1.6 times compared with T100 across all sites (P < 0.05). After 1 yr, complete stover removal (TO) increased Cl by 1.4 times and SHEAR by 1.3 times at NAEW compared with T100 and 175, but Cl increases at other sites were nonsignificant. At NWAES, TO increased SHEAR by 26% compared with T100 (P < 0.05). The TO decreased 0, by two to four times except in winter months and increased rho(b) by about 10% compared with T100 (P < 0.05). In a short-term test, stover removal resulted in increased soil crust strength and reduced soil water content. C1 Ohio State Univ, Carbon Management & Sequestrat Ctr, FAES, OARDC,Sch Nat Resources, Columbus, OH 43210 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Joint Global Change Res Inst, College Pk, MD 20740 USA. USDA ARS, Coshocton, OH 43812 USA. RP Blanco-Canqui, H (reprint author), Ohio State Univ, Carbon Management & Sequestrat Ctr, FAES, OARDC,Sch Nat Resources, 2021 Coffey Rd, Columbus, OH 43210 USA. EM blanco.16@osu.edu RI Post, Wilfred/B-8959-2012; Izaurralde, Roberto/E-5826-2012; Lal, Rattan/D-2505-2013 NR 45 TC 36 Z9 38 U1 0 U2 16 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 USA SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD JAN-FEB PY 2006 VL 70 IS 1 BP 266 EP 278 DI 10.2136/sssaj2005.0137 PG 13 WC Soil Science SC Agriculture GA 009CH UT WOS:000235088200029 ER PT J AU Oostrom, M Hofstee, C Wietsma, TW AF Oostrom, M. Hofstee, C. Wietsma, T. W. TI Behavior of a viscous LNAPL under variable water table conditions SO SOIL & SEDIMENT CONTAMINATION LA English DT Article DE LNAPL; multifluid modeling; residual satuation ID WET POROUS-MEDIA; MONITORING WELLS; RESIDUAL NAPL; VADOSE ZONE; MODEL; SYSTEMS; FLOW; ENTRAPMENT; VALIDATION; IMMOBILE AB An intermediate-scale experiment in a 1.02-m-long, 0.75-m-high, and 0.05-m-wide flow cell was conducted to investigate the behavior of a viscous LNAPL under variable water table conditions. Two viscous LNAPL volumes (0.4 L) were released, one week apart, from a small source zone on top of the flow cell into a partly saturated, homogenously packed porous medium. Following a redistribution period of 30 days after the second release, the water table was increased 0.5 m in 50 minutes. After the water table rise, viscous LNAPL behavior was monitored for an additional 45 days. Fluid saturation scans were obtained periodically with a fully automated dual-energy gamma radiation system. Results show that both spills follow similar paths downwards. Within two hours after the first LNAPL arrival, the capillary fringe was reduced across the cell by approximately 0.04 m (22%). This reduction is directly related to the decrease in the air-water surface tension from 0.072 to 0.057 N/m. LNAPL drainage from the unsaturated zone was relatively slow and a considerable residual LNAPL saturation was observed after 30 days of drainage. Most of the mobile LNAPL moved into the capillary fringe during this period. After a rapid 0.5 m water table rise, the LNAPL moved up in a delayed fashion. The LNAPL used the same path upwards as it used coming clown during the infiltration phase. After 45 days, the LNAPL had moved up only approximately 0.2 m. Since the LNAPL had only moved up a limited amount, non wetting fluid entrapment was limited. The experiment was simulated using the STOMP multifluid flow simulator; which includes entrapped and residual LNAPL saturation formation. A comparison indicates that the simulator is able to predict the observed phenomena well, including residual saturation formation in the vadose zone, and limited upward LNAPL movement after the water table rise. The results of this experiment show that viscous mobile LNAPL, subject to variable water table conditions, does not necessarily float on the water table and may not appear in an observation well. C1 Pacific NW Natl Lab, Hydrol Grp, Richland, WA 99352 USA. TNO, Geoenergy Div, Utrecht, Netherlands. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Oostrom, M (reprint author), Pacific NW Natl Lab, Hydrol Grp, POB 999,MS K9-33, Richland, WA 99352 USA. EM mart.oostrom@pnl.gov NR 27 TC 6 Z9 6 U1 0 U2 4 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1532-0383 J9 SOIL SEDIMENT CONTAM JI Soil. Sediment. Contam. PY 2006 VL 15 IS 6 BP 543 EP 564 DI 10.1080/15320380600958976 PG 22 WC Environmental Sciences SC Environmental Sciences & Ecology GA 098DO UT WOS:000241501400002 ER PT J AU Lester, A Myers, DR AF Lester, A Myers, DR TI A method for improving global pyranometer measurements by modeling responsivity functions SO SOLAR ENERGY LA English DT Article DE pyranometer; responsivity; calibration; uncertainty ID THERMAL OFFSET; IRRADIANCE AB Accurate global solar radiation measurements are crucial to climate change research and the development of solar energy technologies. Pyranometers produce an electrical signal proportional to global irradiance. The signal-to-irradiance ratio is the responsivity (RS) of the instrument (RS = signal/irradiance = microvolts/(W/m(2))). Most engineering measurements are made using a constant RS. It is known that RS varies with day of year, zenith angle, and net infrared radiation. This study proposes a method to find an RS function to model a pyranometer's changing RS. Using a reference irradiance calculated from direct and diffuse instruments, we found instantaneous RS for two global pyranometers over 31 sunny days in a two-year period. We performed successive independent regressions of the error between the constant and instantaneous RS with respect to zenith angle, day of year, and net infrared to obtain an RS function. An alternative method replaced the infrared regression with an independently developed technique to account for thermal offset. Results show improved uncertainties with the function method than with the single-calibration value. Lower uncertainties also occur using a black-and-white (8-48), rather than all-black (PSP), shaded pyranometer as the diffuse reference instrument. We conclude that the function method is extremely effective in reducing uncertainty in the irradiance measurements for global PSP pyranometers if they are calibrated at the deployment site. Furthermore, it was found that the function method accounts for the pyranometer's thermal offset, rendering further corrections unnecessary. The improvements in irradiance data achieved in this study will serve to increase the accuracy of solar energy assessments and atmospheric research. (c) 2005 Elsevier Ltd. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Smith Coll, Northampton, MA 01063 USA. RP Myers, DR (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM daryl_myers@nrel.gov NR 12 TC 14 Z9 14 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-092X J9 SOL ENERGY JI Sol. Energy PY 2006 VL 80 IS 3 BP 322 EP 331 DI 10.1016/j.solener.2005.02.010 PG 10 WC Energy & Fuels SC Energy & Fuels GA 027IL UT WOS:000236408800011 ER PT J AU Aroutiounian, VM Arakelyan, VM Shahnazaryan, GE Stepanyan, GM Khachaturyan, EA Wang, H Turner, JA AF Aroutiounian, V. M. Arakelyan, V. M. Shahnazaryan, G. E. Stepanyan, G. M. Khachaturyan, E. A. Wang, Heli Turner, John A. TI Photoelectrochemistry of semiconductor electrodes made of solid solutions in the system Fe2O3-Nb2O5 SO SOLAR ENERGY LA English DT Article DE semiconductor; photoelectrode; equivalent circuit ID SOLAR-ENERGY; HYDROGEN GENERATION; IMPEDANCE; WATER; INTERFACE AB Ceramic semiconductor photoelectrodes made from solid solutions in the system Fe2O3-Nb2O5 were synthesized. The spectral and capacitance-voltage characteristics of the photoelectrodes were determined, and the dynamic polarization with chopped light was investigated. The anodic photocurrent onset potential, the flat band potential and the shallow and deep donor density of these materials were determined. The threshold photon energies corresponding to the inter-band optical transitions near the edge of the fundamental absorption of the semiconductor photoelectrode were calculated. Analysis of the frequency dispersion of the real and imaginary parts of the complex impedance of photoelectrochemical cell was carried out. On the basis of this analysis, equivalent circuits describing the structure of the double electrical layer of the semiconductor-electrolyte interface were proposed and their parameters calculated. The main limiting steps of the electrode processes, which determine the electrode polarization and current, are defined. (c) 2005 Elsevier Ltd. All rights reserved. C1 Yerevan State Univ, Dept Phys Semicond & Microelect, Yerevan 375025, Armenia. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Aroutiounian, VM (reprint author), Yerevan State Univ, Dept Phys Semicond & Microelect, 1 Alek Manookian St, Yerevan 375025, Armenia. EM kisahar@ysu.am NR 19 TC 34 Z9 35 U1 2 U2 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-092X J9 SOL ENERGY JI Sol. Energy PY 2006 VL 80 IS 9 BP 1098 EP 1111 DI 10.1016/j.solener.2005.10.005 PG 14 WC Energy & Fuels SC Energy & Fuels GA 089FB UT WOS:000240864600004 ER PT B AU Hendron, R Eastment, M Hancock, E Barker, G Reeves, P AF Hendron, Robert Eastment, Mark Hancock, Ed Barker, Greg Reeves, Paul GP ASME TI Evaluation of a high-performance solar home in Loveland, Colorado SO Solar Engineering 2005 LA English DT Proceedings Paper CT International Solar Energy Conference CY AUG 06-12, 2005 CL Orlando, FL SP Sharp, Kycera Solar Inc, Univ Florida, Dept Environm, ACCESS, Innovat Design, ASME, Solar Energy Div AB Building America (BA) partner McStain Neighborhoods built the Discovery House in Loveland, Colorado, with an extensive package of energy-efficient features, including a high-performance envelope, efficient mechanical systems, a solar water heater integrated with the space-heating system, a heat-recovery ventilator (HRV), and ENERGY STAR (TM) appliances. The National Renewable Energy Laboratory (NREL) and Building Science Consortium (BSC) conducted short-term field-testing and building energy simulations to evaluate the performance of the house. These evaluations are utilized by BA to improve future prototype designs and to identify critical research needs. The Discovery House building envelope and ducts were very tight under normal operating conditions. The HRV provided fresh air at a rate of about 75 cfm (35 l/s), consistent with the recommendations of ASHRAE Standard 62.2. The solar hot water system is expected to meet the bulk of the domestic hot water (DHW) load (> 83%), but only about 12% of the space-heating load. DOE-2.2 simulations predict wholehouse source energy savings of 54% compared to the BA Benchmark [1]. The largest contributors to energy savings beyond McStain's standard practice are the solar water heater, HRV, improved air distribution, high-efficiency boiler, and compact fluorescent lighting package. C1 Natl Renewable Energy Lab, Golden, CO USA. RP Hendron, R (reprint author), Natl Renewable Energy Lab, Golden, CO USA. NR 4 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 0-7918-4737-3 PY 2006 BP 143 EP 151 PG 9 WC Energy & Fuels SC Energy & Fuels GA BFO21 UT WOS:000243400500017 ER PT B AU Blair, N Mehos, M Christensen, C Janzou, S AF Blair, Nate Mehos, Mark Christensen, Craig Janzou, Steve GP ASME TI Cost and performance solar analysis model for all solar technologies SO Solar Engineering 2005 LA English DT Proceedings Paper CT International Solar Energy Conference CY AUG 06-12, 2005 CL Orlando, FL SP Sharp, Kycera Solar Inc, Univ Florida, Dept Environm, ACCESS, Innovat Design, ASME, Solar Energy Div AB A comprehensive solar technology systems analysis model is being developed at NREL to support program planning for the U.S. Department of Energy's Solar Energy Technologies Program (SETP). This new model will calculate the costs, finances and performance of current solar technologies including solar heat (typically solar domestic hot water), concentrating solar power, photovoltaics (PV) and solar hybrid lighting. The primary function of the model is to allow users to investigate the impact of variations in physical, cost, and financial parameters to better understand their impact on key figures of merit. Although a variety of models already exist to examine various issues with each individual technology, this model, when fully implemented in the future, will have the capability to analyze and compare different solar technologies (utility-scale PV vs. CSP for example) within the same interface while making use of similar cost and financing assumptions. A central idea for this model is to have a user-friendly interface while at the same time having a detailed, accurate analysis for each of the technologies. The underlying performance engine, which is hidden from the user, is TRNSYS, which already contains an extensive library of solar technology models. There are built-in cost models or the user can access their own spreadsheet-based cost model. The financial model is an extension of an existing validated finance model. This paper will discuss the goals and implementation of the model and present several sample results for interesting sensitivities. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Blair, N (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 2 TC 0 Z9 0 U1 0 U2 5 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 0-7918-4737-3 PY 2006 BP 225 EP 228 PG 4 WC Energy & Fuels SC Energy & Fuels GA BFO21 UT WOS:000243400500026 ER PT B AU Moore, L Post, H Adams, K Malczynski, L Hauck, R Jesperson, T Skinner, R Anderson, J AF Moore, Larry Post, Hal Adams, Krista Malczynski, Len Hauck, Randy Jesperson, Tom Skinner, Rolland Anderson, Jerry GP ASME TI Operation and maintenance field experience with photovoltaic water pumping systems SO Solar Engineering 2005 LA English DT Proceedings Paper CT International Solar Energy Conference CY AUG 06-12, 2005 CL Orlando, FL SP Sharp, Kycera Solar Inc, Univ Florida, Dept Environm, ACCESS, Innovat Design, ASME, Solar Energy Div AB This paper presents an assessment of the failure modes, operation and maintenance (O&M) costs, and system lifecycle costs for 77 photovoltaic (PV) water pumping systems installed during a fourteen year period from 1990 to 2004. These systems were supplied, installed, operated and maintained through a customer lease program by two rural utilities, Northwest Rural Public Power District in Nebraska and Verendrye Electric Cooperative in North Dakota. Field records have been tracked and analyzed to capture maintenance events, component failure experience, repair/replacement costs and installation cost histories. The results of these analyses including annual O&M cost, failure rates, and economic comparisons with grid extension options are presented and discussed. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Moore, L (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 5 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 0-7918-4737-3 PY 2006 BP 509 EP 513 PG 5 WC Energy & Fuels SC Energy & Fuels GA BFO21 UT WOS:000243400500061 ER PT B AU Walker, A Kandt, A Heimiller, D AF Walker, Andy Kandt, Alicen Heimiller, Donna GP ASME TI Wave power for US Coast Guard First District lighthouses SO Solar Engineering 2005 LA English DT Proceedings Paper CT International Solar Energy Conference CY AUG 06-12, 2005 CL Orlando, FL SP Sharp, Kycera Solar Inc, Univ Florida, Dept Environm, ACCESS, Innovat Design, ASME, Solar Energy Div DE wave power; lighthouse; gravity wave physics; coast guard AB Lighthouses and other navigational aids are situated near tumultuous seas and thus may be good candidates for early applications of wave energy conversion technologies. The U.S. Coast Guard First District is converting lighthouses' electrical systems to solar power to divest itself of electrical submarine cables and overhead costs associated with cable maintenance, However, in some lighthouses solar conversion is impractical or may compromise historic preservation. Unless alternative energy sources become available for these locations, they will continue to use submarine cables to run on shore power, Lighthouse sites for which shoreline and wave characteristics are suitable would be good candidates for a wave energy demonstration project. This paper describes gravity wave physics and the characteristics of mechanical radiation (growth, propagation, diffraction, and shoaling). A simple expression for energy content of a wave train with a two-parameter Bretschneider spectrum is applied to spectral wave density data collected from 15 buoys to evaluate wave energy resource potential at 3 1 candidate lighthouse sites in New England. Annual average wave power per meter of wavecrest varied from 3.9 to 21.7 kW/m at the buoys, and from 3.9 to 9.2 kW/m (with an average of 5.0 kW/m) at the lighthouses (buoys with maximum wave power are far out to sea, but still influence the correlation). The performance characteristics of two types of wave energy conversion technologies are used to calculate annual energy delivery by way of example. The paper concludes with a discussion of economics and environmental and permitting issues. It identifies Seguin Island light off a point in Maine and Nauset Beach, Chatham, Nantucket, and Sankaty Head lights (on Nantucket Island and along the outer shore of Cape Cod) as the best sites to begin more detailed evaluations, based on a comparison of wave power and utility rates. Subsequent studies would include demand profile for lighthouses, supply profiles, and resulting storage requirements. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Walker, A (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 11 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 0-7918-4737-3 PY 2006 BP 573 EP 580 PG 8 WC Energy & Fuels SC Energy & Fuels GA BFO21 UT WOS:000243400500069 ER PT B AU Kolb, GJ Diver, RB Siegel, N AF Kolb, Gregory J. Diver, Richard B. Siegel, Nathan GP ASME TI Central-station solar hydrogen power plant SO Solar Engineering 2005 LA English DT Proceedings Paper CT International Solar Energy Conference CY AUG 06-12, 2005 CL Orlando, FL SP Sharp, Kycera Solar Inc, Univ Florida, Dept Environm, ACCESS, Innovat Design, ASME, Solar Energy Div AB Solar power towers can be used to make hydrogen on a large scale. Electrolyzers could be used to convert solar electricity produced by the power tower to hydrogen, but this process is relatively inefficient. Rather, efficiency can be much improved if solar heat is directly converted to hydrogen via a thermochemical process. In the research summarized here, the marriage of a high-temperature (similar to 1000 degrees C) power tower with a sulfuric acid/hybrid thermochemical cycle (SAHT) was studied. The concept combines a solar power tower, a solid-particle receiver, a particle thermal energy storage system, and a hybrid-sulfuric-acid cycle. The cycle is "hybrid" because it produces hydrogen with a combination of thermal input and an electrolyzer. This solar thermochemical plant is predicted to produce hydrogen at a much lower cost than a solarelectrolyzer plant of similar size. To date, only small lab-scale tests have been conducted to demonstrate the feasibility of a few of the subsystems and a key immediate issue is demonstration of flow stability within the solid-particle receiver. The paper describes the systems analysis that led to the favorable economic conclusions and discusses the future development path. C1 Sandia Natl Labs, Solar Syst Dept, Albuquerque, NM 87123 USA. RP Kolb, GJ (reprint author), Sandia Natl Labs, Solar Syst Dept, POB 5800, Albuquerque, NM 87123 USA. NR 16 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 0-7918-4737-3 PY 2006 BP 645 EP 650 PG 6 WC Energy & Fuels SC Energy & Fuels GA BFO21 UT WOS:000243400500076 ER PT B AU Moss, TA Brosseau, DA AF Moss, Timothy A. Brosseau, Douglas A. GP ASME TI Test results of a Schott HCE using a LS-2 collector SO Solar Engineering 2005 LA English DT Proceedings Paper CT International Solar Energy Conference CY AUG 06-12, 2005 CL Orlando, FL SP Sharp, Kycera Solar Inc, Univ Florida, Dept Environm, ACCESS, Innovat Design, ASME, Solar Energy Div AB Sandia National Laboratories has completed thermal performance testing on the Schott parabolic trough receiver using the LS-2 collector on the Sandia rotating platform at the National Solar Thermal Test Facility in Albuquerque, NM. This testing was funded as part of the US DOE Sun-Lab USA-Trough program. The receiver tested was a new Schott receiver, known as Heat Collector Elements (HCEs). Schott is a new manufacturer of trough HCEs. The Schott HCEs are 4m long; therefore, two were joined and mounted on the LS-2 collector module for the test. The Schott HCE design consists of a 70mm diameter high solar absorptance coated stainless steel (SS) tube encapsulated within a 125mm diameter Pyrex((R)) glass tube with vacuum in the annulus formed between the SS and glass tube to minimize convection heat losses. The Schott LICE design is unique in two regards. First, the bellows used to compensate for the difference in thermal expansion between the metal and glass tube are inside the glass envelope rather than outside. Second, the composition of materials at the glass-tometal seal has very similar thermal expansion coefficients making the joint less prone to breakage from thermal shock. Sandia National Laboratories provided both the azimuth and elevation collector module tracking systems used during the tests. The test results showed the efficiency of the Schott HCE to be very similar to current HCEs being manufactured by Solel. This testing provided performance verification for the use of Schott tubes with Solargenix trough collector assemblies at currently planned trough power plant projects in Arizona and Nevada. C1 Sandia Natl Labs, Albuquerque, NM 87123 USA. RP Moss, TA (reprint author), Sandia Natl Labs, POB 5800,MS1127, Albuquerque, NM 87123 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 0-7918-4737-3 PY 2006 BP 737 EP 740 PG 4 WC Energy & Fuels SC Energy & Fuels GA BFO21 UT WOS:000243400500090 ER PT B AU Kennedy, CE Price, H AF Kennedy, C. E. Price, H. GP ASME TI Progress in development of high-temperature solar-selective coating SO Solar Engineering 2005 LA English DT Proceedings Paper CT International Solar Energy Conference CY AUG 06-12, 2005 CL Orlando, FL SP Sharp, Kycera Solar Inc, Univ Florida, Dept Environm, ACCESS, Innovat Design, ASME, Solar Energy Div DE absorbers; high-temperature; parabolic trough; solar-selective coating ID FILMS AB Improving the properties of the selective coating on the receiver represents one of the best opportunities for improving the efficiency of parabolic trough collectors and reducing the cost of solar electricity. Additionally, increasing the operating temperature above the current operating limits of 400 degrees C can improve power cycle efficiency and reduce the cost of thermal energy storage resulting in reductions in the cost of solar electricity. Current coatings do not have the stability and performance necessary to move to higher operating temperatures. The objective of this effort was to develop new, more-efficient selective coatings with both high solar absorptance (alpha >= 0.96) and low thermal emittance (epsilon <= 0.07 at 400 degrees C) that are thermally stable above 500 degrees C, ideally in air, with improved durability and manufacturability and reduced cost. Using computer-aided design software, we successfully modeled a solar-selective coating composed of materials stable at high temperature that exceeded our property goals. In preparation for characterization of samples of these new coatings, a round-robin experiment was conducted to verify the accuracy of the selective coating reflectance measurements. C1 NREL, Golden, CO 80401 USA. RP Kennedy, CE (reprint author), NREL, 1617 Cole Blvd,MS-3321, Golden, CO 80401 USA. NR 14 TC 1 Z9 1 U1 0 U2 6 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 0-7918-4737-3 PY 2006 BP 749 EP 755 PG 7 WC Energy & Fuels SC Energy & Fuels GA BFO21 UT WOS:000243400500092 ER PT B AU Kennedy, CE Terwilliger, K Jorgensen, GJ AF Kennedy, C. E. Terwilliger, K. Jorgensen, G. J. GP ASME TI Analysis of accelerated exposure testing of thin-glass mirror matrix SO SOLAR ENGINEERING 2005 LA English DT Proceedings Paper CT International Solar Energy Conference CY AUG 06-12, 2005 CL Orlando, FL SP Sharp, Kycera Solar Inc, Univ Florida, Dept Environm, ACCESS, Innovat Design, ASME, Solar Energy Div DE thin-glass; mirror; copperless; lead-free paint AB Concentrating solar power (CSP) companies have deployed thin-glass mirrors produced by wet silver processes on similar to 1-mm-thick, relatively lightweight glass. These mirrors have been bonded to metal substrates in commercial installations. Initial hemispherical reflectance is similar to 93% to 96%, and the cost is similar to$16.1/m(2) to $43.0/m(2). These mirrors have the confidence of the CSP industry. However, corrosion was observed in mirror elements of operational solar systems deployed outdoors for 2 years. NREL's advanced optical materials team was assigned to investigate the problem. First, it was noted that this corrosion is very similar to the corrosion bands and spots observed on small (45 mm x 67 mm) thin-glass mirrors laminated to metal substrates with several different types of adhesives and subjected to accelerated exposure testing (AET) at NREL. These samples exhibited corrosion at the unprotected edges and along cracks, and the choice of adhesive affected the performance of weathered thin-glass mirrors. Secondly, two significant changes in mirror manufacture have occurred in the wet-chemistry process because of environmental concerns. The first is the method of forming a copper-free reflective mirror, and the second is the use of lead-free paints. A test matrix of 84 combinations of sample constructions (mirror type / back protective paint / adhesive / substrate) was devised for AET as a designed experiment to identify the most promising mirrors, paints, and adhesives for use with concentrator designs. Two types of accelerated exposure were used: an Atlas Ci5000 WeatherOmeter (WOM) and a damp-heat chamber. Based on an analysis of variance (ANOVA), the various factors and interactions were modeled. These samples now have almost 24 months of accelerated exposure. Analysis of the thin-glass mirror matrix indicated that the Glaverbel mirror with a copperless formulation demonstrates slightly better performance compared to the Naugatuck standard copper-containing mirror and new copperless constructions although most results are within experimental uncertainty. Analysis of the thin-glass mirror matrix indicates commercial (non-mirror) back-protective paint applied after mirror manufacturing is not beneficial. Degradation of the samples exposed to date in the damp-heat chamber is similar, but at a rate 10 times faster than observed for samples in the WOM. We will discuss the results of the continued exposure testing of these mirror samples. Although glass mirrors with copper back-layers and heavily leaded paints have been considered robust for outdoor use, the new copperless back-layer and lead-free paint systems were designed for interior mirror applications and the outdoor durability must be determined. C1 NREL, Golden, CO 80401 USA. RP Kennedy, CE (reprint author), NREL, 1617 Cole Blvd,MS-3321, Golden, CO 80401 USA. EM cheryl_kennedy@nrel.gov; kent_terwilliger@nrel.gov; gary_jorgensen@nrel.gov NR 16 TC 0 Z9 0 U1 1 U2 5 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 0-7918-4737-3 PY 2006 BP 757 EP 763 PG 7 WC Energy & Fuels SC Energy & Fuels GA BFO21 UT WOS:000243400500093 ER PT B AU Moens, L Blake, DM AF Moens, Luc Blake, Daniel M. GP ASME TI Advanced heat transfer and thermal storage fluids SO Solar Engineering 2005 LA English DT Proceedings Paper CT International Solar Energy Conference CY AUG 06-12, 2005 CL Orlando, FL SP Sharp, Kycera Solar Inc, Univ Florida, Dept Environm, ACCESS, Innovat Design, ASME, Solar Energy Div DE thermal storage; heat transfer; high-boiling esters AB The design of the next generation solar parabolic trough systems for power production will require the development of new thermal energy storage options with improved economics or operational characteristics. Current heat transfer fluids such as VP-1 (TM) which consist of a eutectic mixture of biphenyl and diphenyl oxide, allow a maximum operating temperature of ca. 300 degrees C for a direct thermal storage system, At higher temperatures the vapor pressure would become too high and would require pressure rated tanks. The use of VP-1 (TM) also suffers from a freezing point around 13 degrees C that requires heating during cold periods. One of the goals for future trough systems is the use of heat transfer fluids that can act as thermal storage media and that are stable to around 425 degrees C and have a freezing point near or below 0 degrees C. This paper presents an outline of our latest approach towards the development of such thermal storage fluids. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Moens, L (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 9 TC 0 Z9 0 U1 0 U2 3 PU AMER SOC MECHANICAL ENGINEERS PI NEW YORK PA THREE PARK AVENUE, NEW YORK, NY 10016-5990 USA BN 0-7918-4737-3 PY 2006 BP 791 EP 793 PG 3 WC Energy & Fuels SC Energy & Fuels GA BFO21 UT WOS:000243400500097 ER PT S AU Ghirardi, ML Cohen, J King, P Schulten, K Kim, K Seibert, M AF Ghirardi, Maria L. Cohen, Jordi King, Paul Schulten, Klaus Kim, Kwiseon Seibert, Michael BE Vayssieres, L TI [FeFe]-hydrogenases and photobiological hydrogen production SO Solar Hydrogen and Nanotechnology SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Solar Hydrogen and Nanotechnology CY AUG 14-17, 2006 CL San Diego, CA SP SPIE DE hydrogen; green algae; photosynthesis; hydrogenase; Clostridium; O-2 inactivation; computational simulation ID FE-ONLY HYDROGENASES; ESCHERICHIA-COLI; H-CLUSTER AB The promise of efficient, economic and renewable H-2 photoproduction from water can potentially be met by green algae. These organisms are able to functionally link photosynthetic water oxidation to the catalytic recombination of protons and electrons to generate H-2 gas through the activity of the hydrogenase enzyme. Green algal hydrogenases contain a unique metallo-catalytic H-cluster that performs the reversible H-2 oxidation /evolution reactions. The H-cluster, located in the interior of the protein structure is irreversibly inactivated by O-2, the by-product of water oxidation. We developed an Escherichia coli expression system to produce [FeFe]-hydrogenases from different biological sources and demonstrated that clostridial [FeFe]-hydrogenases have higher tolerance to O-2 inactivation compared to their algal counterparts. We have been using computational simulations of gas diffusion within the Clostridium pasteurianum CpI hydrogenase to identify the pathways through which O-2 can reach its catalytic site. Subsequently, we modify the protein structure at specific sites along the O-2 pathways (identified by the computational simulations) by site-directed mutagenesis with the goal of generating recombinant enzymes with higher O-2 tolerance. In this paper, we review the computational simulation work and report on preliminary results obtained through this strategy. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Ghirardi, ML (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. RI King, Paul/D-9979-2011 OI King, Paul/0000-0001-5039-654X NR 19 TC 4 Z9 4 U1 0 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 0-8194-6419-8 J9 P SOC PHOTO-OPT INS PY 2006 VL 6340 BP U257 EP U262 DI 10.1117/12.683767 PG 6 WC Energy & Fuels; Nanoscience & Nanotechnology SC Energy & Fuels; Science & Technology - Other Topics GA BFM09 UT WOS:000243024600025 ER PT S AU Guo, JH AF Guo, Jinghua BE Vayssieres, L TI Understanding the electronic properties of hydrogen storage materials with photon-in/photon-out soft-x-ray spectroscopy SO Solar Hydrogen and Nanotechnology SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Solar Hydrogen and Nanotechnology CY AUG 14-17, 2006 CL San Diego, CA SP SPIE DE synchrotron radiation; soft-x-ray spectroscopy; electronic structure; photon-in/photon-out in-situ study; X-ray absorption; X-ray emission; hydrogen storage materials; hydrogen chemisorption; hydrogen physisorption ID METAL-ORGANIC FRAMEWORKS; CARBON NANOSTRUCTURES; SOLID-SOLUTION; ADSORPTION; ALLOYS; ABSORPTION; DESORPTION; NANOTUBES; MAGNESIUM; HYDRIDE AB How do we learn about chermisorption and physisorption of hydrides and the kinetics of hydrogen adsorption and desorption? These are profound challenges with us for decades. Soft-x-ray spectroscopy will be will be a unique tool to study the electronic properties of fundamental materials, nanoporous, and complex hydrides and in-situ study the kinetics of hydrogen adsorption and desorption. To facilitate the search for most efficient hydrogen-generation and storage compounds, a fundamental understanding of the electronic proper-ties is essential. Hydrogen strongly affects the electronic and structural properties of many materials. The electronic structure ultimately determines the properties of matter. Photon-in/photon-out soft-x-ray spectroscopy has been the subject to a revived interest owing to the new generation synchrotron facilities and high performance beamline and instruments. Soft-x-ray absorption spectroscopy (XAS) probes the local unoccupied electronic structure, soft-x-ray emission spectroscopy (XES) probes the local occupied electronic structure, and resonant inelastic soft-x-ray scattering (RIXS) probes the intrinsic low-energy excitations, such as charge transfer, proton energy transfer etc. A number of examples, including some recent experimental findings, then illustrate the potential of XAS and XES applications in hydrogen energy sciences. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Guo, JH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 44 TC 0 Z9 0 U1 3 U2 10 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-6419-8 J9 P SOC PHOTO-OPT INS PY 2006 VL 6340 BP U28 EP U38 DI 10.1117/12.679211 PG 11 WC Energy & Fuels; Nanoscience & Nanotechnology SC Energy & Fuels; Science & Technology - Other Topics GA BFM09 UT WOS:000243024600003 ER PT S AU King, PW Svedruzic, D Cohen, J Schulten, K Seibert, M Ghirardi, ML AF King, Paul W. Svedruzic, Drazenka Cohen, Jordi Schulten, Klaus Seibert, Michael Ghirardi, Maria L. BE Vayssieres, L TI Structural and functional investigations of biological catalysts for optimization of solar-driven, H-2 production systems SO Solar Hydrogen and Nanotechnology SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Solar Hydrogen and Nanotechnology CY AUG 14-17, 2006 CL San Diego, CA SP SPIE DE [FeFe] hydrogenase; protein engineering; recombinant expression ID CLOSTRIDIUM-PASTEURIANUM; MOLECULAR-DYNAMICS; HYDROGENASE; OXIDATION; ENZYME; DIFFUSION; PROTEINS; CELL; CPL; O-2 AB Research efforts to develop efficient systems for H-2 production encompass a variety of biological and chemical approaches. For solar-driven H2 production we are investigating an approach that integrates biological catalysts, the [FeFe] hydrogenases, with a photoelectrochemical cell as a novel bio-hybrid system. Structurally the [FeFe] hydrogenases consist of an iron-sulfur catalytic site that in some instances is electronically wired to accessory iron-sulfur clusters proposed to function in electron transfer. The inherent structural complexity of most examples of these enzymes is compensated by characteristics desired for bio-hybrid systems (i.e., low activation energy, high catalytic activity and solubility) with the benefit of utilizing abundant, less costly non-precious metals. Redesign and modification of [FeFe] hydrogenases is being undertaken to reduce complexity and to optimize structural properties for various integration strategies. The least complex examples of [FeFe] hydrogenase are found in the species of photosynthetic green algae and are being studied as design models for investigating the effects of structural minimization on substrate transfer, catalytic activity and oxygen sensitivity. Redesigning hydrogenases for effective use in bio-hybrid systems requires a detailed understanding of the relationship between structure and catalysis. To achieve better mechanistic understanding of [FeFe] hydrogenases both structural and dynamic models are being used to identify potential substrate transfer mechanisms which are tested in an experimental system. Here we report on recent progress of our investigations in the areas of [FeFe] hydrogenase overexpression, minimization and biochemical characterization. C1 Natl Renewable Energy Lab, Chem & Biosci Ctr, Golden, CO 80401 USA. RP King, PW (reprint author), Natl Renewable Energy Lab, Chem & Biosci Ctr, Golden, CO 80401 USA. RI King, Paul/D-9979-2011 OI King, Paul/0000-0001-5039-654X NR 21 TC 1 Z9 1 U1 0 U2 4 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-6419-8 J9 P SOC PHOTO-OPT INS PY 2006 VL 6340 BP U263 EP U271 DI 10.1117/12.693636 PG 9 WC Energy & Fuels; Nanoscience & Nanotechnology SC Energy & Fuels; Science & Technology - Other Topics GA BFM09 UT WOS:000243024600026 ER PT S AU Komanicky, V Chang, KC Menzel, A Hennessy, D Karapetrov, G You, HD AF Komanicky, Vladimir Chang, Kee-Chul Menzel, Andreas Hennessy, Daniel Karapetrov, Goran You, Hoydoo BE Vayssieres, L TI Fabrication of platinum nano-array model catalysts SO Solar Hydrogen and Nanotechnology SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Solar Hydrogen and Nanotechnology CY AUG 14-17, 2006 CL San Diego, CA SP SPIE DE catalysis; electrocatalysis; nanoparticles; lithography; platinum; fuel cells ID SULFURIC-ACID; SURFACES; NANOPARTICLES; GROWTH; CARBON; SHAPE AB We fabricated and characterized one- and two- dimensional nanoscale arrays of platinum for study of model catalysts. One-dimensional arrays of nanoscale facets were fabricated by annealing a high-index plan of platinum single crystals. The high-index plane forms rows of alternating two low-index facets, (111) and (100), widths of which are similar to 10 nanorneters. Two-dimensional arrays were fabricated lithographically from the epitaxial films of platinum grown on SrTiO3 substrates. Electron beam lithography was used to create precisely registered square arrays of millions of identical platinum nanocrystals with similar to 30 nm in diameter. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60516 USA. RP You, HD (reprint author), Argonne Natl Lab, Div Mat Sci, Argonne, IL 60516 USA. RI Hennessy, Daniel/A-6203-2011; Chang, Kee-Chul/O-9938-2014; You, Hoydoo/A-6201-2011; Karapetrov, Goran/C-2840-2008; Menzel, Andreas/C-4388-2012 OI Chang, Kee-Chul/0000-0003-1775-2148; You, Hoydoo/0000-0003-2996-9483; Karapetrov, Goran/0000-0003-1113-0137; Menzel, Andreas/0000-0002-0489-609X NR 16 TC 0 Z9 0 U1 0 U2 6 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-6419-8 J9 P SOC PHOTO-OPT INS PY 2006 VL 6340 BP U278 EP U284 DI 10.1117/12.681707 PG 7 WC Energy & Fuels; Nanoscience & Nanotechnology SC Energy & Fuels; Science & Technology - Other Topics GA BFM09 UT WOS:000243024600028 ER PT J AU Hillman, DD Chumbley, LS AF Hillman, D. D. Chumbley, L. S. TI Characterization of tin oxidation products using sequential electrochemical reduction analysis (SERA) SO SOLDERING & SURFACE MOUNT TECHNOLOGY LA English DT Article DE oxides; electronics industry; electrochemical corrosion ID ELECTRON-ENERGY-LOSS; SPECTROSCOPY; AUGER; ALLOYS; SNO; TEMPERATURE; LIQUID; FILMS AB Purpose - To evaluate the oxide formation characteristics of tin (Sn) as a function of conditioning treatment and define a conditioning methodology that rapidly produces a tin oxide thickness and oxide species morphology similar to those formed in ambient oxidation. Design/methodology/approach - Electrochemical reduction analysis and scanning electron microscopy techniques were utilized to identify tin oxide species and oxide quantities on tin samples which were subjected to a variety of conditioning methodologies. Findings - Tin oxide species were identified and oxide quantities measured. Comparisons of tin oxide species/quantities were completed for the different conditioning methodologies used and for other industry oxide investigations. The following conclusions were reached: all conditioning methodologies produced both SnO and SnO2 tin oxide species; steam conditioning produced the thickest oxides; the conditioning methodologies investigated were found to produce oxide thicknesses similar to those formed under ambient conditions. Research limitations/implications - Further investigation would be beneficial using this study as a foundation. Additional conditioning methodologies and a larger selection of various tin surfaces would provide a future understanding of the impact of oxide species and thickness on solderability. Practical implications - The electronics industry has attempted to "predict" a surface's susceptibility to oxidation by using accelerated conditioning techniques. An understanding of the formation of tin oxidation products created by accelerated conditioning techniques could be highly beneficial to the electronics industry. The standardization and use of a realistic accelerated conditioning technique would reduce testing cycle time, increase the predictability and consistency of test results, and lower testing costs. Originality/value - This paper was incorporated into an original electronics manufacturer's solderability testing/analysis procedures, and the results are being utilized by the electronics industry solderability specification task groups/committees. C1 Rockwell Collins Inc, Adv Operat Engn Dept, Cedar Rapids, IA 52498 USA. Iowa State Univ, Ames Lab, US DOE Lab, Ames, IA USA. RP Hillman, DD (reprint author), Rockwell Collins Inc, Adv Operat Engn Dept, Cedar Rapids, IA 52498 USA. NR 32 TC 6 Z9 6 U1 0 U2 1 PU EMERALD GROUP PUBLISHING LIMITED PI BRADFORD PA 60/62 TOLLER LANE, BRADFORD BD8 9BY, W YORKSHIRE, ENGLAND SN 0954-0911 J9 SOLDER SURF MT TECH JI Solder. Surf. Mt. Technol. PY 2006 VL 18 IS 3 BP 31 EP 41 DI 10.1108/09540910610685420 PG 11 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Engineering; Materials Science; Metallurgy & Metallurgical Engineering GA 073FF UT WOS:000239727700005 ER PT J AU Wei, Y Chow, CL Fang, HE Lu, W Lim, J AF Wei, Y Chow, CL Fang, HE Lu, W Lim, J TI Modelling of microstructure and damage evolution in Sn-Pb solder SO SOLDERING & SURFACE MOUNT TECHNOLOGY LA English DT Article DE solders; minimalist manufacturing; modelling; failure modes and effects analysis; mechanics ID CONSTITUTIVE MODEL; FATIGUE AB Purpose - This paper aims to present a viscoplastic constitutive model of Sn-Pb solder taking into account the evolution of microstructure and damage growth in the material. Design/methodology/approach - The microstructure evolution is represented by a parameter describing the coarsening of the phase size, and its resulting evolution equation is established from previous experimental data. The damage evolution is derived from the theory of damage mechanics within the framework of irreversible thermodynamics. Both a phase-size parameter and a damage variable are included in the constitutive model. Findings - The model is capable of simulating the effects of Sn-Pb solder microstructure on mechanical behaviour for both bulk material and miniature specimens under monotonic tensile loading. It was found that the expected failure location determined using the phase-size criterion is identical to that using the damage criterion, but differs from that determined using the von Mises stress criterion. Originality/value - Microstructure and damage evolution are modelled for Sn-Pb solder. Some simulation results are compared with the experimental data to provide the necessary validation of the damage/microstructure-coupled constitutive model. C1 Univ Michigan, Dept Mech Engn, Dearborn, MI 48128 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Wei, Y (reprint author), Univ Michigan, Dept Mech Engn, Dearborn, MI 48128 USA. NR 13 TC 0 Z9 0 U1 0 U2 6 PU EMERALD GROUP PUBLISHING LIMITED PI BRADFORD PA 60/62 TOLLER LANE, BRADFORD BD8 9BY, W YORKSHIRE, ENGLAND SN 0954-0911 J9 SOLDER SURF MT TECH JI Solder. Surf. Mt. Technol. PY 2006 VL 18 IS 1 BP 44 EP 51 DI 10.1108/09540910647107 PG 8 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Engineering; Materials Science; Metallurgy & Metallurgical Engineering GA 021HO UT WOS:000235974500005 ER PT J AU Park, S Kang, K Yoon, WS Moodenbaugh, AR Lewis, LH Vogt, T AF Park, S. Kang, K. Yoon, W. -S. Moodenbaugh, A. R. Lewis, L. H. Vogt, T. TI Magnetic spin glass properties of the bi-layer hydrate Na(0.3)NiO(2)(.)1.3H(2)O SO SOLID STATE COMMUNICATIONS LA English DT Article DE oxides; spin glass; magnetism ID KAGOME LATTICE; FRUSTRATION; TRANSITION; BEHAVIOR; NANIO2; PHASE AB The magnetic properties of the new metal oxide bi-layer hydrate Na0.3NiO2.1.3H(2)O were investigated. DC and AC magnetic susceptibility measurements revealed the compound to be a spin glass at low temperatures with a freezing point of T-f similar to 3.5 K. Using the Vogel-Fulcher relationship an activation energy of E-a/k similar to 71.6 K, a Vogel-Fulcher temperature of T-o similar to 1.9 K and a frequency dependence of the freezing temperature consistent with a frustrated magnetic spin-glass rather than a RKKY spin glass were determined. Ni K-edge X-ray absorption spectroscopy (XAS) show an absorption edge shift toward higher energies in Na0.3NiO2.1.3H(2)O compared to Nao.7NiO2 and suggests that Ni occurs in two possible electronic configurations: a combination of 3d(7) (S=1/2) and 3d(6) (S=0) or 3d(7)L states, with L representing a hole in the oxygen p-states. (c) 2006 Elsevier Ltd. All rights reserved. C1 Univ S Carolina, Dept Chem & Biochem, USC NanoCtr, Columbia, SC 29208 USA. Brookhaven Natl Lab, Condensed Matter Phys & Mat Sci Dept, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Vogt, T (reprint author), Univ S Carolina, Dept Chem & Biochem, USC NanoCtr, 1212 Greene St, Columbia, SC 29208 USA. EM tvogt@gwm.sc.edu RI Yoon, Won-Sub/H-2343-2011; Vogt, Thomas /A-1562-2011; OI Vogt, Thomas /0000-0002-4731-2787; Moodenbaugh, Arnold/0000-0002-3415-6762 NR 24 TC 6 Z9 6 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PY 2006 VL 139 IS 2 BP 60 EP 63 DI 10.1016/j.ssc.2006.04.036 PG 4 WC Physics, Condensed Matter SC Physics GA 069LC UT WOS:000239446900004 ER PT J AU Punnoose, A Engelhard, MH Hays, J AF Punnoose, A. Engelhard, M. H. Hays, J. TI Dopant distribution, oxygen stoichiometry and magnetism of nanoscale Sn0.99Co0.01O2 SO SOLID STATE COMMUNICATIONS LA English DT Article DE nanoparticles; tin oxide; dilute magnetic semiconductors; ferromagnetism ID THIN-FILMS; FERROMAGNETIC SEMICONDUCTORS; ROOM-TEMPERATURE; TIN OXIDE; DOPED ZNO; TRANSITION AB In recent work, we have shown that chemically synthesized Sn1-xCoxO2 nanoscale powders with x <= 0.01 are ferromagnetic at room temperature when prepared by annealing the reaction precipitate in the narrow temperature window of 350-600 degrees C. Combined high resolution x-ray photoelectron spectroscopy (on as-prepared and Ar+ ion sputtered samples), x-ray diffraction and magnetometry measurements showed that the Co distribution is more uniform throughout the individual Sn0.99Co0.01O2 particles when prepared at lower annealing temperatures of 350-600 degrees C and this uniform dopant distribution is essential to produce stable high temperature ferromagnetism. However, surface segregation of the dopant atoms in samples annealed at > 600 degrees C destroys the room-temperature ferromagnetic behavior and reduces the Curie temperature to < 300 K. (c) 2006 Elsevier Ltd. All rights reserved. C1 Boise State Univ, Dept Phys, Boise, ID 83725 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Punnoose, A (reprint author), Boise State Univ, Dept Phys, Boise, ID 83725 USA. EM apunnoos@boisestate.edu RI Engelhard, Mark/F-1317-2010; OI Engelhard, Mark/0000-0002-5543-0812 NR 21 TC 14 Z9 14 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PY 2006 VL 139 IS 8 BP 434 EP 438 DI 10.1016/j.ssc.2005.09.040 PG 5 WC Physics, Condensed Matter SC Physics GA 082NP UT WOS:000240393900011 ER PT J AU Gateshki, M Petkov, V Hyeon, T Joo, J Niederberger, M Ren, Y AF Gateshki, M Petkov, V Hyeon, T Joo, J Niederberger, M Ren, Y TI Interplay between the local structural disorder and the length of structural coherence in stabilizing the cubic phase in nanocrystalline ZrO2 SO SOLID STATE COMMUNICATIONS LA English DT Article DE nanocrystalline materials; X-ray diffraction; structure determination ID X-RAY-DIFFRACTION; HIGH-TEMPERATURE; ZIRCONIA; CRYSTALLINE AB The atomic-scale structure of three nanocrystalline ZrO2 samples obtained by different techniques and possessing a different length of structural coherence has been studied using high-energy X-ray diffraction and the atomic pair distribution function technique. The studies reveal that all samples show a monoclinic-like local atomic ordering. Only when the length of structural coherence exceeds 1 nm the atomic arrangement evolves into a cubic-type one. The result underlines the importance of both the local structural disorder and the length of structural coherence, i.e. the spatial extent of longer-range atomic order, in stabilizing the technologically important cubic zirconia at room temperature. (c) 2006 Elsevier Ltd. All rights reserved. C1 Cent Michigan Univ, Dept Phys, Mt Pleasant, MI 48859 USA. Seoul Natl Univ, Natl Creat Res Initiat Ctr Oxide Nanocrystalline, Seoul 151744, South Korea. Seoul Natl Univ, Sch Chem & Biol Engn, Seoul 151744, South Korea. Max Planck Inst Colloids & Interfaces, D-14424 Potsdam, Germany. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Petkov, V (reprint author), Cent Michigan Univ, Dept Phys, Mt Pleasant, MI 48859 USA. EM petkov@phy.cmich.edu RI Niederberger, Markus/A-6144-2008; Hyeon, Taeghwan/J-5315-2012; Lee, Junyoung/D-5463-2012 OI Niederberger, Markus/0000-0001-6058-1183; Lee, Junyoung/0000-0001-6689-2759 NR 16 TC 10 Z9 10 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PY 2006 VL 138 IS 6 BP 279 EP 284 DI 10.1016/j.ssc.2006.03.013 PG 6 WC Physics, Condensed Matter SC Physics GA 047KK UT WOS:000237878000003 ER PT J AU Dalpian, GM Wei, SH Gong, XG da Silva, AJR Fazzio, A AF Dalpian, Gustavo M. Wei, Su-Huai Gong, X. G. da Silva, Antonio J. R. Fazzio, A. TI Phenomenological band structure model of magnetic coupling in semiconductors SO SOLID STATE COMMUNICATIONS LA English DT Article DE semiconductor; band structure; magnetic properties ID MOLECULAR-BEAM-EPITAXY; 1ST PRINCIPLES; FERROMAGNETISM; SPINTRONICS; GAN; ALLOYS; ENERGY; PHASE; GAMNN AB A unified band structure model is proposed to explain the magnetic ordering in Mn-doped semiconductors. This model is based on the p-d and d-d level repulsions between the Mn ions and host elements and can successfully explain magnetic ordering observed in all Mn doped II-VI and III-V semiconductors such as CdTe, GaAs, ZnO, and GaN. The model can also be used to explain the interesting behavior of GaMnN, which changes from ferromagnetic ordering to antiferromagnetic ordering as the Mn concentration increases. This model, therefore, is useful to provide a simple guideline for future band structure engineering of magnetic semiconductors. (c) 2006 Elsevier Ltd. All rights reserved. C1 Natl Renewable Energy Lab, Basic Sci Ctr, Golden, CO 80401 USA. Fudan Univ, Dept Phys, Shanghai 200433, Peoples R China. Chinese Acad Sci, Inst Solid State Phys, Hefei 230031, Peoples R China. Univ Sao Paulo, Inst Fis, BR-05315970 Sao Paulo, SP, Brazil. RP Wei, SH (reprint author), Natl Renewable Energy Lab, Basic Sci Ctr, 1617 Cole Blvd, Golden, CO 80401 USA. EM swei@nrel.gov RI Dalpian, Gustavo/B-9746-2008; gong, xingao /B-1337-2010; gong, xingao/D-6532-2011 OI Dalpian, Gustavo/0000-0001-5561-354X; NR 36 TC 91 Z9 92 U1 1 U2 13 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PY 2006 VL 138 IS 7 BP 353 EP 358 DI 10.1016/j.ssc.2006.03.002 PG 6 WC Physics, Condensed Matter SC Physics GA 056LH UT WOS:000238523900006 ER EF