FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Olalla, C Deline, C Maksimovic, D AF Olalla, Carlos Deline, Chris Maksimovic, Dragan TI Performance of Mismatched PV Systems With Submodule Integrated Converters SO IEEE JOURNAL OF PHOTOVOLTAICS LA English DT Article DE DC-DC converters; modeling and control of power electronics; photovoltaic modules; renewable energy systems; SubMICs; SubModule integrated converters ID PHOTOVOLTAIC APPLICATIONS; EQUALIZATION; ENERGY AB Mismatch power losses in photovoltaic (PV) systems can be reduced by the use of distributed power electronics at the module or submodule level. This paper presents an experimentally validated numerical model that can be used to predict power production with distributed maximum power point tracking (DMPPT) down to the cell level. The model allows the investigations of different DMPPT architectures, as well as the impact of conversion efficiencies and power constraints. Results are presented for annual simulations of three representative partial shading scenarios and two scenarios where mismatches are due to aging over a period of 25 years. It is shown that DMPPT solutions that are based on submodule integrated converters offer 6.9-11.1% improvements in annual energy yield relative to a baseline centralized MPPT scenario. C1 [Olalla, Carlos] Univ Rovira & Virgili, Dept Elect Elect & Automat Control Engn, E-43007 Tarragona, Spain. [Deline, Chris] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Maksimovic, Dragan] Univ Colorado, Dept Elect Comp & Energy Engn, Boulder, CO 80309 USA. RP Olalla, C (reprint author), Univ Rovira & Virgili, Dept Elect Elect & Automat Control Engn, E-43007 Tarragona, Spain. EM carlos.olalla@urv.cat; chris.deline@nrel.gov; maksimov@colorado.edu RI Olalla, Carlos/A-8571-2012 OI Olalla, Carlos/0000-0001-8333-9840 FU Advanced Research Projects Agency-Energy, U.S. Department of Energy [DE-AR0000216]; Generalitat de Catalunya, Beatriu de Pinos programme [BP-B00047] FX Manuscript received June 24, 2013; revised August 14, 2013; accepted September 5, 2013. Date of publication October 9, 2013; date of current version December 16, 2013. This work was supported in part by the Advanced Research Projects Agency-Energy, U.S. Department of Energy, under Award DE-AR0000216 and in part by the Generalitat de Catalunya, Beatriu de Pinos programme, under Award BP-B00047. NR 35 TC 32 Z9 33 U1 0 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 2156-3381 J9 IEEE J PHOTOVOLT JI IEEE J. Photovolt. PD JAN PY 2014 VL 4 IS 1 BP 396 EP 404 DI 10.1109/JPHOTOV.2013.2281878 PG 9 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 280NZ UT WOS:000329038800060 ER PT J AU Yang, BB Cruz-Campa, JL Haase, GS Cole, EI Tangyunyong, P Resnick, PJ Kilgo, AC Okandan, M Nielson, GN AF Yang, Benjamin B. Cruz-Campa, Jose L. Haase, Gaddi S. Cole, Edward I., Jr. Tangyunyong, Paiboon Resnick, Paul J. Kilgo, Alice C. Okandan, Murat Nielson, Gregory N. TI Failure Analysis Techniques for Microsystems-Enabled Photovoltaics SO IEEE JOURNAL OF PHOTOVOLTAICS LA English DT Article DE Failure analysis; photovoltaic (PV) cells; silicon; solar energy AB Microsystems-enabled photovoltaics (MEPV) has great potential to meet the increasing demands for light-weight, photovoltaic solutions with high power density and efficiency. This paper describes effective failure analysis techniques to localize and characterize nonfunctional or underperforming MEPV cells. The defect localization methods such as electroluminescence under forward and reverse bias, as well as optical beam induced current using wavelengths above and below the device band gap, are presented. The current results also show that the MEPV has good resilience against degradation caused by reverse bias stresses. C1 [Yang, Benjamin B.; Cruz-Campa, Jose L.; Haase, Gaddi S.; Cole, Edward I., Jr.; Tangyunyong, Paiboon; Resnick, Paul J.; Kilgo, Alice C.; Okandan, Murat; Nielson, Gregory N.] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Yang, BB (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM bbyang@sandia.gov; jlcruzc@sandia.gov; gshaase@sandia.gov; coleei@sandia.gov; ptangyu@sandia.gov; resnicpj@sandia.gov; ackilgo@sandia.gov; mokanda@sandia.gov; gnniels@sandia.gov FU U.S. Department of Energy's National Nuclear Security Administration [DE-AC04-94AL85000] FX Manuscript received June 16, 2013; revised August 6, 2013; accepted September 15, 2013. Date of publication October 24, 2013; date of current version December 16, 2013. Sandia National Laboratories is a multiprogram laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. NR 12 TC 1 Z9 1 U1 1 U2 14 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 2156-3381 J9 IEEE J PHOTOVOLT JI IEEE J. Photovolt. PD JAN PY 2014 VL 4 IS 1 BP 470 EP 476 DI 10.1109/JPHOTOV.2013.2284864 PG 7 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 280NZ UT WOS:000329038800070 ER PT J AU Huang, B Chen, SY Deng, HX Wang, LW Contreras, MA Noufi, R Wei, SH AF Huang, Bing Chen, Shiyou Deng, Hui-Xiong Wang, Lin-Wang Contreras, Miguel A. Noufi, Rommel Wei, Su-Huai TI Origin of Reduced Efficiency in Cu(In,Ga)Se-2 Solar Cells With High Ga Concentration: Alloy Solubility Versus Intrinsic Defects SO IEEE JOURNAL OF PHOTOVOLTAICS LA English DT Article DE CIGS; defects; first-principles calculations; photovoltaics ID QUASI-RANDOM STRUCTURES; PHASE-DIAGRAMS; CUINSE2; FILMS; SEMICONDUCTORS AB It is well known that adding Ga to CuInSe2 forming CuIn1-xGaxSe2 (CIGS) alloy can significantly improve the solar cell efficiency, but adding too much Ga will lead to a decline of the solar cell efficiency. The exact origin of this puzzling phenomenon is currently still under debate. It is especially unclear whether it is caused by either structural or electronic issues. In this paper, we conclude that the defect issue, especially antisite defects M-Cu (M = In, Ga), rather than the alloy solubility is the key problem for the reduced efficiency in CIGS. The deep levels that are induced by M-Cu defects can pin the open-circuit voltage (V-oc) of CIGS. Self-compensation in CIGS, which forms 2V(Cu) + M-Cu defect complexes, is found to be beneficial to quenching the deep-trap levels induced by M-Cu in CIGS. Unfortunately, the density of isolated M-Cu is quite high and cannot be largely converted into 2V(Cu) + M-Cu complexes under thermal equilibrium condition. Thus, nonequilibrium growth conditions or low growth temperature that can suppress the formation of the deep-trap centers M-Cu will be necessary to improve the efficiency of CIGS solar cells, especially with high Ga concentrations. C1 [Huang, Bing; Deng, Hui-Xiong; Contreras, Miguel A.; Noufi, Rommel; Wei, Su-Huai] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Chen, Shiyou; Wang, Lin-Wang] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Huang, B (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. EM huangbing05@gmail.com; Suhuai.Wei@nrel.gov RI Huang, Bing/D-8941-2011 OI Huang, Bing/0000-0001-6735-4637 FU U.S. Department of Energy [DE-AC36-08GO28308] FX Manuscript received July 5, 2013; revised August 26, 2013; accepted October 6, 2013. Date of publication October 28, 2013; date of current version December 16, 2013. The work at the National Renewable Energy Laboratory was supported by the U.S. Department of Energy under Contract DE-AC36-08GO28308. NR 44 TC 14 Z9 14 U1 3 U2 63 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 2156-3381 J9 IEEE J PHOTOVOLT JI IEEE J. Photovolt. PD JAN PY 2014 VL 4 IS 1 BP 477 EP 482 DI 10.1109/JPHOTOV.2013.2285617 PG 6 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 280NZ UT WOS:000329038800071 ER PT J AU Yuan, JY Wang, DL Li, RX AF Yuan, Jiangye Wang, DeLiang Li, Rongxing TI Remote Sensing Image Segmentation by Combining Spectral and Texture Features SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE Segmentation; singular value decomposition (SVD); spectral histogram; texture ID CLASSIFICATION; HISTOGRAMS; COLOR; MATRIX AB We present a new method for remote sensing image segmentation, which utilizes both spectral and texture information. Linear filters are used to provide enhanced spatial patterns. For each pixel location, we compute combined spectral and texture features using local spectral histograms, which concatenate local histograms of all input bands. We regard each feature as a linear combination of several representative features, each of which corresponds to a segment. Segmentation is given by estimating combination weights, which indicate segment ownership of pixels. We present segmentation solutions where representative features are either known or unknown. We also show that feature dimensions can be greatly reduced via subspace projection. The scale issue is investigated, and an algorithm is presented to automatically select proper scales, which does not require segmentation at multiple-scale levels. Experimental results demonstrate the promise of the proposed method. C1 [Yuan, Jiangye] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. [Wang, DeLiang] Ohio State Univ, Dept Comp Sci & Engn, Columbus, OH 43210 USA. [Wang, DeLiang] Ohio State Univ, Ctr Cognit Sci, Columbus, OH 43210 USA. [Li, Rongxing] Ohio State Univ, Dept Civil & Environm Engn & Geodet Sci, Mapping & GIS Lab, Columbus, OH 43210 USA. RP Yuan, JY (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. EM yuanj@ornl.gov; dwang@cse.ohio-state.edu; li.282@osu.edu FU National Geospatial-Intelligence Agency University Research Initiatives [HM 1582-07-1-2027]; summer Graduate Research Associate award from the Center for Cognitive Science at The Ohio State University FX This work was supported in part by the National Geospatial-Intelligence Agency University Research Initiatives under Grant HM 1582-07-1-2027 and a summer Graduate Research Associate award from the Center for Cognitive Science at The Ohio State University. NR 26 TC 18 Z9 20 U1 1 U2 26 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0196-2892 EI 1558-0644 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 2014 VL 52 IS 1 BP 16 EP 24 DI 10.1109/TGRS.2012.2234755 PN 1 PG 9 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 279CW UT WOS:000328938400002 ER PT J AU Makarov, YV Du, PW Pai, MA McManus, B AF Makarov, Yuri V. Du, Pengwei Pai, M. A. McManus, Bart TI Calculating Individual Resources Variability and Uncertainty Factors Based on Their Contributions to the Overall System Balancing Needs SO IEEE TRANSACTIONS ON SUSTAINABLE ENERGY LA English DT Article DE Balancing authority (BA); intermittency rates; operating reserves; system balancing requirements ID CONTROL ANCILLARY SERVICES; WIND INTEGRATION; FREQUENCY; FEATURES AB The variability and uncertainty of wind power production require increased flexibility in the power systems, or more operational reserves to maintain a satisfactory level of reliability. The incremental increase in reserve requirement caused by wind power is often studied separately from the effects of loads. Accordingly, the cost in procuring reserves is allocated based on this simplification rather than a fair and transparent calculation of the different resources' contribution to the reserve requirement. This work proposes a new allocation mechanism for variability and uncertainty of resources regardless of their type. It is based on a new formula called the grid-balancing metric (GBM). The proposed GBM has several distinct features: 1) it is directly linked to the control performance standard scores and interconnection frequency performance, 2) it provides scientifically defined allocation factors for individual resources, 3) the sum of allocation factors within any group of resources is equal to the groups' collective allocation factor (linearity), and 4) it distinguishes helpers and harmers. The paper illustrates and provides results of the new approach based on actual transmission system operator data. C1 [Makarov, Yuri V.; Du, Pengwei] Pacific NW Natl Lab, Adv Power & Energy Syst Grp, Richland, WA 99352 USA. [Pai, M. A.] Univ Illinois, Dept Elect & Comp Engn, Urbana, IL 61801 USA. [McManus, Bart] Bonneville Power Adm, Portland, OR 97232 USA. RP Makarov, YV (reprint author), Pacific NW Natl Lab, Adv Power & Energy Syst Grp, Richland, WA 99352 USA. EM yuri.makarov@pnnl.gov; pengwei.du@pnnl.gov; mapai@illinois.edu; bamcmanus@bpa.gov NR 19 TC 3 Z9 4 U1 3 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1949-3029 J9 IEEE T SUSTAIN ENERG JI IEEE Trans. Sustain. Energy PD JAN PY 2014 VL 5 IS 1 BP 323 EP 331 DI 10.1109/TSTE.2013.2283712 PG 9 WC GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY; Energy & Fuels; Engineering, Electrical & Electronic SC Science & Technology - Other Topics; Energy & Fuels; Engineering GA 279GS UT WOS:000328949000035 ER PT J AU Cingarapu, S Singh, D Timofeeva, EV Moravek, MR AF Cingarapu, Sreeram Singh, Dileep Timofeeva, Elena V. Moravek, Michael R. TI Nanofluids with encapsulated tin nanoparticles for advanced heat transfer and thermal energy storage SO INTERNATIONAL JOURNAL OF ENERGY RESEARCH LA English DT Article DE thermal energy storage; heat transfer fluid; nanofluid; core-shell nanoparticles; phase change material; latent heat; thermal conductivity; tin nanoparticles ID PHASE-CHANGE MATERIALS; PCM; CONDUCTIVITY; SIZE; SOLIDIFICATION; NANOCRYSTALS; TEMPERATURE; PARTICLES; SYSTEMS; SILICA AB Novel high-temperature heat transfer fluids (HTFs) with incorporated phase change nanomaterials were synthesized and tested for heat transfer and thermal energy storage. The advanced thermal properties were achieved by preparing a nanofluid consisting of core/shell silica encapsulated tin (Sn/SiO2) nanoparticles dispersed in a synthetic HTF Therminol 66 (TH66) at loadings up to 5 vol%. Tin nanoparticles were synthesized by modified polyole reduction method followed by sol-gel silica encapsulation process. The measured increase in thermal conductivity of the nanofluid (13% at 5 vol%) was in agreement with Maxwell's effective medium theory. Latent heat of phase change during melting of Sn core added 11% increase to the volumetric thermal energy storage of the nanofluid when cycled in between 100 degrees C and 270 degrees C. The value could be further improved if thermal cycling is conducted in a narrower temperature range. The experimental results demonstrated dual functionality of the engineered nanofluids as desired for Concentrated Solar Power systems. Viscosity and stability of the nanofluids as well as thermal stability of core/shell nanomaterials) were investigated in a wide temperature range to obtain a perspective on any additional pumping power requirements for the nanofluid over the base fluid. Copyright (c) 2013 John Wiley & Sons, Ltd. C1 [Cingarapu, Sreeram; Singh, Dileep; Moravek, Michael R.] Argonne Natl Lab, Nucl Engn Div, Argonne, IL 60439 USA. [Timofeeva, Elena V.] Argonne Natl Lab, Div Energy Syst, Argonne, IL 60439 USA. RP Singh, D (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM dsingh@anl.gov RI Timofeeva, Elena/E-6391-2010; OI Timofeeva, Elena V./0000-0001-7839-2727 FU US Department of Energy's EERE's Solar Energy Technology Program - ARRA; UChicago Argonne, LLC [DE-AC02-06CH11357] FX We appreciate Dr. Nestor J. Zaluzec help in conducting high resolution TEM. This work was supported by US Department of Energy's EERE's Solar Energy Technology Program - ARRA funding. The electron microscopy was accomplished at the Electron Microscopy Center for Materials Research at Argonne National Laboratory, a U.S. Department of Energy Office of Science Laboratory operated under Contract No. DE-AC02-06CH11357 by UChicago Argonne, LLC. NR 29 TC 19 Z9 19 U1 6 U2 72 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0363-907X EI 1099-114X J9 INT J ENERG RES JI Int. J. Energy Res. PD JAN PY 2014 VL 38 IS 1 BP 51 EP 59 DI 10.1002/er.3041 PG 9 WC Energy & Fuels; Nuclear Science & Technology SC Energy & Fuels; Nuclear Science & Technology GA 266BN UT WOS:000327997400008 ER PT J AU Zhou, BT Muralidharan, G Kurumadalli, K Parish, CM Leslie, S Bieler, TR AF Zhou, Bite Muralidharan, Govindarajan Kurumadalli, Kanth Parish, Chad M. Leslie, Scott Bieler, Thomas R. TI Microstructure and Sn Crystal Orientation Evolution in Sn-3.5Ag Lead-Free Solders in High-Temperature Packaging Applications SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE High-temperature packaging; texture evolution; thermal cycling; recrystallization; dislocation slip ID THERMOMECHANICAL FATIGUE; DAMAGE EVOLUTION; JOINTS; RECRYSTALLIZATION; RELIABILITY; ANISOTROPY; BEHAVIOR; STRAIN; ALLOY AB Understanding the reliability of eutectic Sn-3.5Ag lead-free solders in high-temperature packaging applications is of significant interest in power electronics for the next-generation electric grid. Large-area (2.5 mm x 2.5 mm) Sn-3.5Ag solder joints between silicon dies and direct bonded copper substrates were thermally cycled between 5A degrees C and 200A degrees C. Sn crystal orientation and microstructure evolution during thermal cycling were characterized by electron backscatter diffraction in the scanning electron microscope. Comparisons were made between the observed initial texture and microstructure and its evolution during thermal cycling. Gradual lattice rotation and grain boundary misorientation evolution observed due to thermal cycling suggested a continuous recrystallization mechanism. Recrystallization behavior was correlated with dislocation slip activities. C1 [Zhou, Bite; Muralidharan, Govindarajan; Kurumadalli, Kanth; Parish, Chad M.] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. [Leslie, Scott] Powerex Inc, Youngwood, PA 15697 USA. [Zhou, Bite; Bieler, Thomas R.] Michigan State Univ, E Lansing, MI 48824 USA. RP Zhou, BT (reprint author), Oak Ridge Natl Lab, Bldg 4508,MS-6083,1 Bethel Valley Rd, Oak Ridge, TN 37831 USA. EM muralidhargn@ornl.gov RI Parish, Chad/J-8381-2013; Muralidharan, Govindarajan/J-6155-2015; OI Parish, Chad/0000-0003-1209-7439 FU US Department of Energy, Office of Electricity Delivery; SHaRE User Facility; Scientific User Facilities Division of the Office of Science; NSF-GOALI [1006656] FX The authors would like to acknowledge Jackie Mayotte for metallography. This work was sponsored by the US Department of Energy, Office of Electricity Delivery, and by the SHaRE User Facility supported by the Scientific User Facilities Division of the Office of Science. Work at Michigan State University was also partially supported by NSF-GOALI Contract 1006656 (B.Z. and T.R.B.). NR 28 TC 8 Z9 8 U1 1 U2 34 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0361-5235 EI 1543-186X J9 J ELECTRON MATER JI J. Electron. Mater. PD JAN PY 2014 VL 43 IS 1 BP 57 EP 68 DI 10.1007/s11664-013-2788-4 PG 12 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 281MA UT WOS:000329104500008 ER PT J AU DeGeorge, V Shen, S Ohodnicki, P Andio, M Mchenry, ME AF DeGeorge, V. Shen, S. Ohodnicki, P. Andio, M. Mchenry, M. E. TI Multiphase Resistivity Model for Magnetic Nanocomposites Developed for High Frequency, High Power Transformation SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE Resistivity; nanocomposite; soft magnetic; high frequency; power conversion; power electronics ID (FE0.5CO0.5)(88)ZR7B4CU1 NANOCRYSTALLINE ALLOYS; LOCAL MOMENT VARIATION; B ALLOYS; ELECTRICAL-RESISTIVITY; ELECTRONIC TRANSPORT; MONOLAYER MAGNETISM; TRANSITION-METALS; AMORPHOUS METALS; 4-POINT PROBE; IRON AB New power conversion systems that offer promise to transform electricity grids into unified interactive supply networks require high-resistivity soft-magnetic materials to allow for switching of magnetic materials at frequencies approaching 100 kHz for power transformation in the megawatt range. Amorphous and nanocomposite soft-magnetic materials, which represent the state of the art in terms of high power densities and low losses at high frequencies, have resistivities that depend on the structures and spatial distributions of multiple phases in thin ribbons. We present a multiphase resistivity model applicable to nanocomposite materials by considering an equivalent circuit approach considering paths through an amorphous, crystalline, and growth inhibitor shell phase. We detail: (a) identification of amorphous, crystalline, and shell phases; (b) consideration of the role of the morphology of each phase in an equivalent circuit model for the resistance; (c) a two-band model for the Fe/Co composition dependence of the resistivity in crystalline and amorphous phases; (d) a virtual bound state model for resistivity to explain increased resistivity due to early transition-metal growth inhibitors in the shell surrounding the nanocrystalline phase; and (e) disorder effects on amorphous phase resistivity. Experimental design and results for systems of interest in high-frequency power transformation are discussed in the context of our model including: (a) techniques for measurements of cross-section and density, (b) four-point probe and surface resistivity measurements, and (c) measurements in Fe- and Co-rich systems comparing amorphous and nanocomposite materials. C1 [DeGeorge, V.; Shen, S.; Ohodnicki, P.; Mchenry, M. E.] Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. [Ohodnicki, P.; Andio, M.] Natl Energy Technol Lab, Morgantown, WV USA. RP DeGeorge, V (reprint author), Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. EM vdegeorg@andrew.cmu.edu RI Shen, Shen/B-9065-2014 FU NSF through Magnetics A Division of Spang and Company [W911NF-12-2-0040]; ARPA-E [DE-AR000 0219]; agency of the United States Government FX M.E.M. and S. S. acknowledge support of the NSF through Magnetics A Division of Spang and Company as a subcontract to the ARL (Contract Number W911NF-12-2-0040). M. E. M. and V. D. acknowledge support from ARPA-E (Award Number DE-AR000 0219). This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. NR 76 TC 7 Z9 7 U1 1 U2 14 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0361-5235 EI 1543-186X J9 J ELECTRON MATER JI J. Electron. Mater. PD JAN PY 2014 VL 43 IS 1 BP 96 EP 108 DI 10.1007/s11664-013-2835-1 PG 13 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 281MA UT WOS:000329104500012 ER PT J AU Ohodnicki, PR Sokalski, V Baltrus, J Kortright, JB Zuo, X Shen, S DeGeorge, V McHenry, ME Laughlin, DE AF Ohodnicki, P. R., Jr. Sokalski, V. Baltrus, J. Kortright, J. B. Zuo, X. Shen, S. DeGeorge, V. McHenry, M. E. Laughlin, D. E. TI Structure-Property Correlations in CoFe-SiO2 Nanogranular Films Utilizing x-Ray Photoelectron Spectroscopy and Small-Angle Scattering Techniques SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE CoFe; nanogranular; superparamagnet; dipolar interactions; small-angle scattering; x-ray photoelectron spectroscopy ID SOFT-MAGNETIC-PROPERTIES; GRANULAR FILMS; MULTILAYERS; SYSTEMS; ALLOYS AB A quantitative structure-property correlation study of thin films consisting of CoFe nanoparticles embedded in SiO2 is presented, comparing film microstructure and chemistry with measured magnetic properties. SiO2 was fully percolated for all films with > similar to 50% SiO2 by volume, and decreasing CoFe-nanoparticle size and separation with increasing SiO2 resulted in a transition to superparamagnetic behavior. Partial oxidation of transition-metal elements is observed by x-ray photoelectron spectroscopy, and evidence for interparticle magnetic interactions can be resolved in soft x-ray resonant small-angle scattering experiments, highlighting the need for additional detailed and quantitative studies in this class of soft magnetic materials. C1 [Ohodnicki, P. R., Jr.] US DOE, Electrochem & Magnet Mat Team, Funct Mat Dev Div, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. [Ohodnicki, P. R., Jr.; Sokalski, V.; Shen, S.; DeGeorge, V.; McHenry, M. E.; Laughlin, D. E.] Carnegie Mellon Univ, Mat Sci & Engn Dept, Pittsburgh, PA 15213 USA. [Baltrus, J.] US DOE, Chem & Surface Sci Div, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. [Kortright, J. B.] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. [Zuo, X.] Argonne Natl Lab, Xray Sci Div, Argonne, IL 60439 USA. [Laughlin, D. E.] Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. RP Ohodnicki, PR (reprint author), US DOE, Electrochem & Magnet Mat Team, Funct Mat Dev Div, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. EM paul.ohodnicki@gmail.com RI Shen, Shen/B-9065-2014; Sokalski, Vincent/F-5419-2015 OI Sokalski, Vincent/0000-0003-4780-7867 FU US DOE [DE-AC02-06CH11357]; NSF [0804020] FX Use of the Advanced Photon Source, an Office of Science User Facility operated for the US Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the US DOE under Contract No. DE-AC02-06CH11357. M. E. M. and D. E. L. acknowledge support of the NSF through Grant No. DMR #0804020. NR 41 TC 1 Z9 1 U1 0 U2 20 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0361-5235 EI 1543-186X J9 J ELECTRON MATER JI J. Electron. Mater. PD JAN PY 2014 VL 43 IS 1 BP 142 EP 150 DI 10.1007/s11664-013-2716-7 PG 9 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA 281MA UT WOS:000329104500019 ER PT J AU Liao, C Guo, BK Jiang, DE Custelcean, R Mahurin, SM Sun, XG Dai, S AF Liao, Chen Guo, Bingkun Jiang, De-en Custelcean, Radu Mahurin, Shannon M. Sun, Xiao-Guang Dai, Sheng TI Highly soluble alkoxide magnesium salts for rechargeable magnesium batteries SO JOURNAL OF MATERIALS CHEMISTRY A LA English DT Article ID ELECTROLYTE-SOLUTIONS; ELECTROCHEMISTRY; STORAGE AB A unique class of air-stable and non-pyrophoric magnesium electrolytes has been developed based on alkoxide magnesium compounds. The crystals obtained from this class of electrolytes exhibit a unique structure of tri-magnesium cluster, [Mg3Cl3(OR)(2)(THF)(6)](+) [(THF)MgCl3](-). High reversible capacities and good rate capabilities have been obtained in Mg-Mo6S8 batteries using these new electrolytes at both 20 and 50 degrees C. C1 [Liao, Chen; Guo, Bingkun; Jiang, De-en; Custelcean, Radu; Mahurin, Shannon M.; Sun, Xiao-Guang; Dai, Sheng] Oak Ridge Natl Lab, Chem Sci Div, Oak Ridge, TN 37831 USA. [Dai, Sheng] Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. RP Liao, C (reprint author), Oak Ridge Natl Lab, Chem Sci Div, Oak Ridge, TN 37831 USA. RI Jiang, De-en/D-9529-2011; Guo, Bingkun/J-5774-2014; Custelcean, Radu/C-1037-2009; Dai, Sheng/K-8411-2015; OI Jiang, De-en/0000-0001-5167-0731; Custelcean, Radu/0000-0002-0727-7972; Dai, Sheng/0000-0002-8046-3931; Liao, Chen/0000-0001-5168-6493 FU U.S. Department of Energy's Office of Basic Energy Science, Division of Materials Sciences and Engineering FX This research was supported by the U.S. Department of Energy's Office of Basic Energy Science, Division of Materials Sciences and Engineering. NR 15 TC 27 Z9 27 U1 7 U2 81 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 2050-7488 EI 2050-7496 J9 J MATER CHEM A JI J. Mater. Chem. A PY 2014 VL 2 IS 3 BP 581 EP 584 DI 10.1039/c3ta13691d PG 4 WC Chemistry, Physical; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Energy & Fuels; Materials Science GA 274ZM UT WOS:000328644700002 ER PT J AU Kuttiyiel, KA Sasaki, K Chen, WF Su, D Adzic, RR AF Kuttiyiel, Kurian A. Sasaki, Kotaro Chen, Wei-Fu Su, Dong Adzic, Radoslav R. TI Core-shell, hollow-structured iridium-nickel nitride nanoparticles for the hydrogen evolution reaction SO JOURNAL OF MATERIALS CHEMISTRY A LA English DT Article ID OXYGEN REDUCTION; FUEL-CELLS; CATALYSTS; ELECTROCATALYSTS AB We synthesized core-shell, hollow-structured iridium-nickel nitride nanoparticles and then evaluated their activity in the hydrogen evolution reaction (HER). Coupling Ni nitrides with the IrNi cores enhances the HER activity of Ir shells to a level comparable to that of Pt/C, while reducing the Ir loading of the catalyst. C1 [Kuttiyiel, Kurian A.; Sasaki, Kotaro; Chen, Wei-Fu; Adzic, Radoslav R.] Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. [Su, Dong] Brookhaven Natl Lab, Ctr Funct Nanomat, Upton, NY 11973 USA. RP Sasaki, K (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM ksasaki@bnl.gov; adzic@bnl.gov RI Su, Dong/A-8233-2013 OI Su, Dong/0000-0002-1921-6683 FU US Department of Energy, Division of Chemical Sciences, Geosciences and Biosciences Division [DE-AC02-98CH10886]; Synchrotron Catalysis Consortium, US Department of Energy [DE-FG02-05ER15688] FX This research was performed at BNL under contract DE-AC02-98CH10886 with the US Department of Energy, Division of Chemical Sciences, Geosciences and Biosciences Division. Beamline X7B at the NSLS is supported in part by the Synchrotron Catalysis Consortium, US Department of Energy Grant No. DE-FG02-05ER15688. NR 13 TC 10 Z9 10 U1 15 U2 111 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 2050-7488 EI 2050-7496 J9 J MATER CHEM A JI J. Mater. Chem. A PY 2014 VL 2 IS 3 BP 591 EP 594 DI 10.1039/c3ta14301e PG 4 WC Chemistry, Physical; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Energy & Fuels; Materials Science GA 274ZM UT WOS:000328644700004 ER PT J AU Blinova, NV Svec, F AF Blinova, N. V. Svec, F. TI Functionalized high performance polymer membranes for separation of carbon dioxide and methane SO JOURNAL OF MATERIALS CHEMISTRY A LA English DT Article ID CA BLEND MEMBRANES; GAS SEPARATION; POLY(ETHYLENE GLYCOL); COMPOSITE MEMBRANES; POLYETHYLENEGLYCOL PEG; FACILITATED TRANSPORT; CO2 SEPARATION; PERMEABILITIES; PERMEATION; COPOLYMER AB A significant enhancement in separation performance of supported polyaniline and polypyrrole membranes after chemical modification via grafting and solvation with a non-volatile liquid, poly(ethylene glycol), has been demonstrated. C1 [Blinova, N. V.; Svec, F.] EO Lawrence Berkeley Natl Lab, Mol Foundry, Berkeley, CA 94720 USA. RP Svec, F (reprint author), EO Lawrence Berkeley Natl Lab, Mol Foundry, Berkeley, CA 94720 USA. EM fsvec@lbl.gov RI EFRC, CGS/I-6680-2012; Stangl, Kristin/D-1502-2015; Foundry, Molecular/G-9968-2014 FU U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences [DE-SC0001015]; Office of Science, Office of Basic Energy Sciences, U.S. Department of Energy [DE-AC02-05CH11231] FX N.V.B., F. S., and the preparation of films were supported as part of the Center for Gas Separations Relevant to Clean Energy Technologies, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001015. Characterization work performed at the Molecular Foundry, Lawrence Berkeley National Laboratory was supported by the Office of Science, Office of Basic Energy Sciences, U.S. Department of Energy, under Contract no. DE-AC02-05CH11231. Thanks are also due to Fedor Kraev (AIST-NT Inc., Novato CA, USA) for the AFM measurements. NR 27 TC 2 Z9 2 U1 5 U2 33 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 2050-7488 EI 2050-7496 J9 J MATER CHEM A JI J. Mater. Chem. A PY 2014 VL 2 IS 3 BP 600 EP 604 DI 10.1039/c3ta14095d PG 5 WC Chemistry, Physical; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Energy & Fuels; Materials Science GA 274ZM UT WOS:000328644700006 ER PT J AU Charnvanichborikarn, S Shin, SJ Worsley, MA Tran, IC Willey, TM van Buuren, T Felter, TE Colvin, JD Kucheyev, SO AF Charnvanichborikarn, S. Shin, S. J. Worsley, M. A. Tran, I. C. Willey, T. M. van Buuren, T. Felter, T. E. Colvin, J. D. Kucheyev, S. O. TI Nanoporous Cu-C composites based on carbon-nanotube aerogels SO JOURNAL OF MATERIALS CHEMISTRY A LA English DT Article ID HYDROGEN STORAGE PROPERTIES; HIGH-SURFACE-AREA; SENSING INDENTATION; NANOPARTICLES; GRAPHENE; NICKEL; COPPER; SUPERCAPACITORS; FORMALDEHYDE; PERFORMANCE AB Current synthesis methods of nanoporous Cu-C composites offer limited control of the material composition, structure, and properties, particularly for large Cu loadings of greater than or similar to 20 wt%. Here, we describe two related approaches to realize novel nanoporous Cu-C composites based on the templating of recently developed carbon-nanotube aerogels (CNT-CAs). Our first approach involves the trapping of Cu nanoparticles while CNT-CAs undergo gelation. This method yields nanofoams with relatively high densities of greater than or similar to 65 mg cm(-3) for Cu loadings of greater than or similar to 10 wt%. Our second approach overcomes this limitation by filling the pores of undoped CNT-CA monoliths with an aqueous solution of CuSO4 followed by (i) freeze-drying to remove water and (ii) thermal decomposition of CuSO4. With this approach, we demonstrate Cu-C composites with a C matrix density of similar to 25 mg cm(-3) and Cu loadings of up to 70 wt %. These versatile methods could be extended to fabricate other nanoporous metal-carbon composite materials geared for specific applications. C1 [Charnvanichborikarn, S.; Shin, S. J.; Worsley, M. A.; Tran, I. C.; Willey, T. M.; van Buuren, T.; Colvin, J. D.; Kucheyev, S. O.] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. [Felter, T. E.] Sandia Natl Labs, Livermore, CA 94550 USA. RP Charnvanichborikarn, S (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM charnvanichb1@llnl.gov; kucheyev@llnl.gov RI Tran, Ich/C-9869-2014; Worsley, Marcus/G-2382-2014; USAXS, APS/D-4198-2013; Foundry, Molecular/G-9968-2014; Willey, Trevor/A-8778-2011 OI Worsley, Marcus/0000-0002-8012-7727; Willey, Trevor/0000-0002-9667-8830 FU U.S. DOE by LLNL [DE-AC52-07NA27344]; U.S. DOE [DE-AC02-05CH11231, DE-AC02-06CH11357]; NSF/DOE [NSF/CHE-0822838] FX We thank Russel Wallace for gluing samples onto stalks, John Sain and Kuang Jen Wu for x-ray radiography measurements, and Jan Ilavsky for assistance with USAXS experiments. This work was performed under the auspices of the U.S. DOE by LLNL under Contract DE-AC52-07NA27344. Transmission electron microscopy experiments were conducted at the National Center for Electron Microscopy, LBNL, which is supported by the U.S. DOE under Contract DE-AC02-05CH11231. Use of the Advanced Photon Source, an Office of Science User Facility operated for the U. S. DOE Office of Science by Argonne National Laboratory, was supported by the U. S. DOE under Contract no. DE-AC02-06CH11357. ChemMatCARS Sector 15 is principally supported by the NSF/DOE under grant number NSF/CHE-0822838. NR 56 TC 9 Z9 9 U1 4 U2 95 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 2050-7488 EI 2050-7496 J9 J MATER CHEM A JI J. Mater. Chem. A PY 2014 VL 2 IS 4 BP 962 EP 967 DI 10.1039/c3ta14303a PG 6 WC Chemistry, Physical; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Energy & Fuels; Materials Science GA 278JO UT WOS:000328886800013 ER PT J AU Solomon, JM Adelstein, N De Jonghe, LC Asta, M AF Solomon, Jonathan M. Adelstein, Nicole De Jonghe, Lutgard C. Asta, Mark TI First principles study of pyrophosphate defects and dopant-defect interactions in stronium-doped lanthanum orthophosphate SO JOURNAL OF MATERIALS CHEMISTRY A LA English DT Article ID SR-SUBSTITUTED LAPO4; TOTAL-ENERGY CALCULATIONS; WAVE BASIS-SET; CRYSTAL STRUCTURE; PROTONIC CONDUCTION; METALS AB LaPO4 has been actively studied for proton conductor applications, due to its stability and proton uptake in humid atmospheres over intermediate temperature ranges. An important process underlying the application of this and related materials for proton-conductor applications is the hydrolysis of pyrophosphate defects. In this work we undertake density-functional-theory (DFT) calculations of the relative energetics of pyrophosphate defects and protons in LaPO4, including their binding with divalent dopant cations. Due to the low symmetry of the monazite crystal structure for LaPO4, there exists four symmetry-distinct pyrophosphate defect configurations; DFT calculations are used to identify the most stable configuration, which is 0.24 eV lower in energy than all others. Further, from supercell calculations with 1.85 mol% Sr doping, we investigate the dopant-binding energies for pyrophosphate defects to be 0.37 eV, which is comparable to the value of 0.34 eV calculated for proton-dopant binding energies in the same system. These results establish that dopant-defect interactions further stabilize proton incorporation, with the hydration enthalpies when the dopants are nearest and furthest from the protons and pyrophosphate defects being -1.66 eV and -1.37 eV, respectively. Even though our calculations show that dopant binding enhances the enthalpic favorability of proton incorporation, they also suggest that such binding is likely to substantially lower the kinetic rate of hydrolysis of pyrophosphate defects. C1 [Solomon, Jonathan M.; De Jonghe, Lutgard C.; Asta, Mark] Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. [Adelstein, Nicole] Lawrence Livermore Natl Lab, Condensed Matter & Mat Div, Livermore, CA USA. [De Jonghe, Lutgard C.; Asta, Mark] Lawrence Livermore Natl Lab, Div Mat Sci, Livermore, CA USA. RP Solomon, JM (reprint author), Univ Calif Berkeley, Dept Mat Sci & Engn, 210 Hearst Mem Min Bldg, Berkeley, CA 94720 USA. EM jsolom@berkeley.edu FU Office of Basic Energy Sciences, Materials Sciences and Engineering Division, of the U.S. Department of Energy [DE-AC02-05CH11231]; Department of Defense through the National Defense Science and Engineering Graduate Fellowship Program; Office of Basic Energy Sciences of the U.S. Dept of Energy [DE-AC02-05CH11231] FX This work was supported by the Office of Basic Energy Sciences, Materials Sciences and Engineering Division, of the U.S. Department of Energy under Contract no. DE-AC02-05CH11231, and by the Department of Defense through the National Defense Science and Engineering Graduate Fellowship Program. This work made use of resources of the National Energy Research Scientific Computing Center, supported by the Office of Basic Energy Sciences of the U.S. Dept of Energy (DE-AC02-05CH11231). The authors would like to thank Hannah L. Ray for useful discussions. NR 28 TC 5 Z9 5 U1 3 U2 18 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 2050-7488 EI 2050-7496 J9 J MATER CHEM A JI J. Mater. Chem. A PY 2014 VL 2 IS 4 BP 1047 EP 1053 DI 10.1039/c3ta13349d PG 7 WC Chemistry, Physical; Energy & Fuels; Materials Science, Multidisciplinary SC Chemistry; Energy & Fuels; Materials Science GA 278JO UT WOS:000328886800024 ER PT J AU Jiang, QL Liu, FQ Li, T Xu, T AF Jiang, Qinglong Liu, Faqian Li, Tao Xu, Tao TI Fast and low voltage-driven solid-state electrochromics using 3-D conductive FTO nanobead electrodes SO JOURNAL OF MATERIALS CHEMISTRY C LA English DT Article ID LITHIUM-ION BATTERIES; POLYMER ELECTROLYTES; SOLAR-CELLS; PERFORMANCE; DEVICES; DISPLAY; FILM AB A solid-state electrochromic device using 3-D conducting fluorinated tin oxide nanobeads (roughness factor >500) as electrodes enables fast electron transport and concentrates the voltage drop at the interfaces. This method reduces the driving voltage to 0.9 V and the response time to similar to 272 ms, far exceeding the performance of conventional 2-D flat FTO film-based counterparts. C1 [Jiang, Qinglong; Liu, Faqian; Xu, Tao] No Illinois Univ, Dept Chem & Biochem, De Kalb, IL 60115 USA. [Li, Tao] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Xu, T (reprint author), No Illinois Univ, Dept Chem & Biochem, De Kalb, IL 60115 USA. EM txu@niu.edu RI li, tao/K-8911-2012 OI li, tao/0000-0001-5454-1468 FU U.S. National Science Foundation [CBET-1150617]; Electron Microscopy Center at the Argonne National Laboratory, U.S. Department of Energy Office of Science Laboratory [AC02-06CH11357] FX We acknowledge the support from the U.S. National Science Foundation (CBET-1150617). The electron microscopy was conducted at the Electron Microscopy Center at the Argonne National Laboratory, U.S. Department of Energy Office of Science Laboratory operated under Contract no. DE-AC02-06CH11357. NR 24 TC 6 Z9 6 U1 2 U2 30 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 2050-7526 EI 2050-7534 J9 J MATER CHEM C JI J. Mater. Chem. C PY 2014 VL 2 IS 4 BP 618 EP 621 DI 10.1039/c3tc31692k PG 4 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 280ZS UT WOS:000329069900003 ER PT J AU Liang, WZ Li, Z Bi, ZX Nan, TX Du, H Nan, CW Chen, CL Jia, QX Lin, Y AF Liang, Weizheng Li, Zheng Bi, Zhenxing Nan, Tianxiang Du, Hui Nan, Cewen Chen, Chonglin Jia, Quanxi Lin, Yuan TI Role of the interface on the magnetoelectric properties of BaTiO3 thin films deposited on polycrystalline Ni foils SO JOURNAL OF MATERIALS CHEMISTRY C LA English DT Article ID POLYMER-ASSISTED DEPOSITION; MULTIFERROIC LAMINATED COMPOSITES; DIELECTRIC-PROPERTIES; TITANATE; GROWTH; SRTIO3; TAPES AB BaTiO3 (BTO) thin films were deposited on polycrystalline Ni foils using a chemical solution approach. We show that the interface between the BTO film and the Ni foil plays a critical role in determining the magnetoelectric (ME) properties of this flexible assembly, which is likely to be related to the evolution of nickel oxide at the interface during the growth of BTO films. Our results have demonstrated that not only a well-controlled interface between the BTO film and the Ni substrate can be achieved, but also an ME voltage coefficient as large as 90 mV cm(-1) Oe(-1) can be accomplished. C1 [Liang, Weizheng; Nan, Tianxiang; Du, Hui; Lin, Yuan] Univ Elect Sci & Technol China, State Key Lab Elect Thin Films & Integrated Devic, Chengdu 610054, Sichuan, Peoples R China. [Li, Zheng; Nan, Cewen] Tsinghua Univ, State Key Lab New Ceram & Fine Proc, Dept Mat Sci & Engn, Beijing 100084, Peoples R China. [Bi, Zhenxing; Jia, Quanxi] Los Alamos Natl Lab, Ctr Integrated Nanotechnol, Los Alamos, NM 87545 USA. [Chen, Chonglin] Univ Texas San Antonio, Dept Phys & Astron, San Antonio, TX 78249 USA. [Chen, Chonglin] Univ Houston, Dept Phys, Houston, TX 77204 USA. [Chen, Chonglin] Univ Houston, Texas Ctr Superconduct, Houston, TX 77204 USA. RP Lin, Y (reprint author), Univ Elect Sci & Technol China, State Key Lab Elect Thin Films & Integrated Devic, Chengdu 610054, Sichuan, Peoples R China. EM linyuan@uestc.edu.cn RI Jia, Q. X./C-5194-2008; lin, yuan/B-9955-2013; Nan, Tianxiang/O-3820-2015; Nan, Tianxiang/A-8020-2016 FU National Basic Research Program of China (973 Program) [2011CB301705]; National Natural Science Foundation of China [51372034, 11329402, 51172036]; U.S. Department of Energy through the Center for Integrated Nanotechnologies; U.S. Department of Energy, Office of Basic Energy Sciences user facility at Los Alamos National Laboratory; Los Alamos National Laboratory is operated by Los Alamos National Security, LLC, for the National Nuclear Security Administration of the U.S. Department of Energy [DE-AC52-06NA25396] FX This work was supported by the National Basic Research Program of China (973 Program) under Grant no. 2011CB301705, the National Natural Science Foundation of China (nos 51372034, 11329402 and 51172036). It was also supported, in part, by the U.S. Department of Energy through the Center for Integrated Nanotechnologies, the U.S. Department of Energy, Office of Basic Energy Sciences user facility at Los Alamos National Laboratory. The Los Alamos National Laboratory is operated by Los Alamos National Security, LLC, for the National Nuclear Security Administration of the U.S. Department of Energy under contract DE-AC52-06NA25396. NR 33 TC 11 Z9 12 U1 9 U2 75 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 2050-7526 EI 2050-7534 J9 J MATER CHEM C JI J. Mater. Chem. C PY 2014 VL 2 IS 4 BP 708 EP 714 DI 10.1039/c3tc31571a PG 7 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 280ZS UT WOS:000329069900016 ER PT J AU Kim, J Chou, J Rotem, D AF Kim, Jinoh Chou, Jerry Rotem, Doron TI iPACS: Power-aware covering sets for energy proportionality and performance in data parallel computing clusters SO JOURNAL OF PARALLEL AND DISTRIBUTED COMPUTING LA English DT Article DE Energy proportionality; Data parallel computing; Covering subset; MapReduce AB Energy consumption in datacenters has recently become a major concern due to the rising operational costs and scalability issues. Recent solutions to this problem propose the principle of energy proportionality, i.e., the amount of energy consumed by the server nodes must be proportional to the amount of work performed. For data parallelism and fault tolerance purposes, most common file systems used in MapReduce-type clusters maintain a set of replicas for each data block. A covering subset is a group of nodes that together contain at least one replica of the data blocks needed for performing computing tasks. In this work, we develop and analyze algorithms to maintain energy proportionality by discovering a covering subset that minimizes energy consumption while placing the remaining nodes in low-power standby mode in a data parallel computing cluster. Our algorithms can also discover covering subset in heterogeneous computing environments. In order to allow more data parallelism, we generalize our algorithms so that it can discover k-covering subset, i.e., a set of nodes that contain at least k replicas of the data blocks. Our experimental results show that we can achieve substantial energy saving without significant performance loss in diverse cluster configurations and working environments. (C) 2013 Elsevier Inc. All rights reserved. C1 [Kim, Jinoh] Texas A&M Univ, Dept Comp Sci, Commerce, TX 75429 USA. [Chou, Jerry] Natl Tsing Hua Univ, Dept Comp Sci, Hsinchu 30013, Taiwan. [Rotem, Doron] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Sci Data Management Grp, Berkeley, CA 94706 USA. RP Kim, J (reprint author), Texas A&M Univ, Dept Comp Sci, POB 3011, Commerce, TX 75429 USA. EM jinoh.kim@tamuc.edu; jchou@cs.nthu.edu.tw; rotem@hpcrd.lbl.gov FU Office of Science, Office of Advanced Scientific Computing Research, of the US Department of Energy [DE-AC02-05CH11231] FX We thank the anonymous reviewers for their constructive comments. This work was supported by the Director, Office of Science, Office of Advanced Scientific Computing Research, of the US Department of Energy under Contract No. DE-AC02-05CH11231. NR 21 TC 1 Z9 1 U1 0 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0743-7315 EI 1096-0848 J9 J PARALLEL DISTR COM JI J. Parallel Distrib. Comput. PD JAN PY 2014 VL 74 IS 1 BP 1762 EP 1774 DI 10.1016/j.jpdc.2013.09.006 PG 13 WC Computer Science, Theory & Methods SC Computer Science GA 278DW UT WOS:000328870300004 ER PT J AU Pan, YL Santarpia, JL Ratnesar-Shumate, S Corson, E Eshbaugh, J Hill, SC Williamson, CC Coleman, M Bare, C Kinahan, S AF Pan, Yong-Le Santarpia, Joshua L. Ratnesar-Shumate, Shanna Corson, Elizabeth Eshbaugh, Jonathan Hill, Steven C. Williamson, Chatt C. Coleman, Mark Bare, Christopher Kinahan, Sean TI Effects of ozone and relative humidity on fluorescence spectra of octapeptide bioaerosol particles SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE Octapeptide bioerosol particles; Fluorescence spectra; Atmospheric age and process; Ozone oxidation; Relative humidity; Rotating reaction chamber ID BIOLOGICAL AEROSOL-PARTICLES; AMINO-ACID-RESIDUES; ATMOSPHERIC AEROSOL; ORGANIC AEROSOL; SERUM-ALBUMIN; PROTEIN; OXIDATION; PEPTIDES; AIR; MICROPARTICLES AB The effects of ozone and relative humidity (RH) at common atmospheric levels on the properties of single octapeptide bioaerosol particles were studied using an improved rotating reaction chamber, an aerosol generator, an ultraviolet aerodynamic particle sizer (UVAPS), an improved single particle fluorescence spectrometer (SPFS), and equipments to generate, monitor and control the ozone and RH. Aerosol particles (mean diameter similar to 2 mu m) were generated from a slurry of octapeptide in phosphate buffered saline, injected into the rotating chamber, and kept airborne for hours. Bioaerosols were sampled from the chamber hourly for the measurements of particle-size distribution, concentration, total fluorescence excited at 355-mu m, and single particle fluorescence spectra excited at 266-nm and 351-nm under different controlled RH (20%, 50%, or 80%) and ozone concentration (0 or 150 ppb). The results show that: (1) Particle size, concentration, and the 263-nm-excited fluorescence intensity decrease at different rates under different combinations of the RH and ozone concentrations used. (2) The 263-nm-excited UV fluorescence (280-400 nm) decreased more rapidly than the 263-nm-excited visible fluorescence (400-560 nm), and decreased most rapidly when ozone is present and RH is high. (3) The UV fluorescence peak near 340 nm slightly shifts to the shorter wavelength (blue-shift), consistent with a more rapid oxidation of tryptophan than tyrosine. (4) The 351/355-nm-excited fluorescence (430-580 nm/380-700 nm) increases when ozone is present, especially when the RH is high. (5) The 351/355-nm-excited fluorescence increase that occurs as the tryptophan emission in the UV decreases, and the observation that these changes occur more rapidly at higher RH with the present of ozone, are consistent with the oxidation of tryptophan by ozone and the conversion of the resulting ozonides to N-formyl kynurenine and kynurenine. (C) 2013 The Authors. Published by Elsevier Ltd. All rights reserved. C1 [Pan, Yong-Le; Hill, Steven C.; Williamson, Chatt C.; Coleman, Mark] US Army Res Lab, Adelphi, MD 20783 USA. [Santarpia, Joshua L.] Sandia Natl Labs, Albuquerque, NM 87123 USA. [Ratnesar-Shumate, Shanna; Corson, Elizabeth; Eshbaugh, Jonathan; Bare, Christopher; Kinahan, Sean] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. RP Pan, YL (reprint author), US Army Res Lab, Adelphi, MD 20783 USA. EM yongle.pan.civ@mail.mil FU Defense Threat Reduction Agency (DTRA) [HDT RA1-10-C-0023]; US Army Research Laboratory (ARL) FX This research was supported by the Defense Threat Reduction Agency (DTRA) under contract number HDT RA1-10-C-0023, and by US Army Research Laboratory (ARL) mission funds. NR 44 TC 7 Z9 7 U1 2 U2 38 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 EI 1879-1352 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD JAN PY 2014 VL 133 BP 538 EP 550 DI 10.1016/j.jqsrt.2013.09.017 PG 13 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 278DH UT WOS:000328868800043 ER PT J AU Kim, Y Gupta, A Urgaonkar, B Berman, P Sivasubramaniam, A AF Kim, Youngjae Gupta, Aayush Urgaonkar, Bhuvan Berman, Piotr Sivasubramaniam, Anand TI HybridPlan: a capacity planning technique for projecting storage requirements in hybrid storage systems SO JOURNAL OF SUPERCOMPUTING LA English DT Article DE Storage systems; Solid-state drives; Resource provisioning; Mathematical optimization and modeling ID FLASH; MEMORY; I/O AB Economic forces, driven by the desire to introduce flash into the high-end storage market without changing existing software-base, have resulted in the emergence of solid-state drives (SSDs), flash packaged in HDD form factors and capable of working with device drivers and I/O buses designed for HDDs. Unlike the use of DRAM for caching or buffering, however, certain idiosyncrasies of NAND Flash-based solid-state drives (SSDs) make their integration into hard disk drive (HDD)-based storage systems nontrivial. Flash memory suffers from limits on its reliability, is an order of magnitude more expensive than the magnetic hard disk drives (HDDs), and can sometimes be as slow as the HDD (due to excessive garbage collection (GC) induced by high intensity of random writes). Given the complementary properties of HDDs and SSDs in terms of cost, performance, and lifetime, the current consensus among several storage experts is to view SSDs not as a replacement for HDD, but rather as a complementary device within the high-performance storage hierarchy. Thus, we design and evaluate such a hybrid storage system with HybridPlan that is an improved capacity planning technique to administrators with the overall goal of operating within cost-budgets. HybridPlan is able to find the most cost-effective hybrid storage configuration with different types of SSDs and HDDs. C1 [Kim, Youngjae] Oak Ridge Natl Lab, Natl Ctr Computat Sci, Oak Ridge, TN USA. [Gupta, Aayush] IBM Almaden Res, San Jose, CA USA. [Urgaonkar, Bhuvan; Berman, Piotr; Sivasubramaniam, Anand] Penn State Univ, Dept Comp Sci & Engn, University Pk, PA 16802 USA. RP Kim, Y (reprint author), Oak Ridge Natl Lab, Natl Ctr Computat Sci, Oak Ridge, TN USA. EM kimy1@ornl.gov; guptaaa@us.ibm.com; bhuvan@cse.psu.edu; berman@cse.psu.edu; anand@cse.psu.edu FU NSF [CCF-0811670]; U.S. DOE [DE-AC05-00OR22725] FX We would like to thank the anonymous reviewers for their detailed comments, which helped us improve the quality of this paper. This research was funded in part by NSF grant CCF-0811670. It was also supported in part by, and used the resources of, the Oak Ridge Leadership Computing Facility, located in the National Center for Computational Sciences at ORNL, which is managed by UT Battelle, LLC for the U.S. DOE (under the contract No. DE-AC05-00OR22725). NR 41 TC 0 Z9 0 U1 0 U2 3 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0920-8542 EI 1573-0484 J9 J SUPERCOMPUT JI J. Supercomput. PD JAN PY 2014 VL 67 IS 1 BP 277 EP 303 DI 10.1007/s11227-013-0999-3 PG 27 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 281OR UT WOS:000329111400013 ER PT J AU Mundboth, K Sutter, J Laundy, D Collins, S Stoupin, S Shvyd'ko, Y AF Mundboth, K. Sutter, J. Laundy, D. Collins, S. Stoupin, S. Shvyd'ko, Y. TI Tests and characterization of a laterally graded multilayer Montel mirror SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE X-ray optics; collimating optics; Montel mirrors; laterally graded multilayers; KB mirrors ID LAYERED SYNTHETIC MICROSTRUCTURES; X-RAY OPTICS; EXTREME-ULTRAVIOLET; ENERGY RESOLUTION; PERFORMANCE; SCATTERING; ELEMENTS AB Multilayers are becoming an increasingly important tool in X-ray optics. The essential parameters to design a pair of laterally graded multilayer mirrors arranged in a Montel-type configuration for use as an X-ray collimating device are provided. The results of X-ray reflectometry tests carried out on the optics in addition to metrology characterization are also shown. Finally, using experimental data and combined with X-ray tracing simulations it is demonstrated that the mirror meets all stringent specifications as required for a novel ultra-high-resolution inelastic X-ray scattering spectrometer at the Advanced Photon Source. C1 [Mundboth, K.; Sutter, J.; Laundy, D.; Collins, S.] Diamond Light Source Ltd, Didcot OX11 0DE, Oxon, England. [Stoupin, S.; Shvyd'ko, Y.] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Mundboth, K (reprint author), Diamond Light Source Ltd, Harwell Sci & Innovat Campus, Didcot OX11 0DE, Oxon, England. EM kiran.mundboth@diamond.ac.uk NR 24 TC 5 Z9 5 U1 0 U2 5 PU INT UNION CRYSTALLOGRAPHY PI CHESTER PA 2 ABBEY SQ, CHESTER, CH1 2HU, ENGLAND SN 1600-5775 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD JAN PY 2014 VL 21 BP 16 EP 23 DI 10.1107/S1600577513024077 PN 1 PG 8 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 279DD UT WOS:000328939400003 PM 24365912 ER PT J AU Bohon, J D'Mello, R Ralston, C Gupta, S Chance, MR AF Bohon, Jen D'Mello, Rhijuta Ralston, Corie Gupta, Sayan Chance, Mark R. TI Synchrotron X-ray footprinting on tour SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE structural biology; footprinting; X-rays; beamlines; radiolysis ID STRUCTURAL MASS-SPECTROMETRY; TETRAHYMENA-THERMOPHILA RIBOZYME; RIBOSOMAL-RNA; IN-VIVO; DYNAMICS; ACTIVATION; RADIOLYSIS; BINDING; ATP; COMPLEXES AB Synchrotron footprinting is a valuable technique in structural biology for understanding macromolecular solution-state structure and dynamics of proteins and nucleic acids. Although an extremely powerful tool, there is currently only a single facility in the USA, the X28C beamline at the National Synchrotron Light Source (NSLS), dedicated to providing infrastructure, technology development and support for these studies. The high flux density of the focused white beam and variety of specialized exposure environments available at X28C enables footprinting of highly complex biological systems; however, it is likely that a significant fraction of interesting experiments could be performed at unspecialized facilities. In an effort to investigate the viability of a beamline-flexible footprinting program, a standard sample was taken on tour around the nation to be exposed at several US synchrotrons. This work describes how a relatively simple and transportable apparatus can allow beamlines at the NSLS, CHESS, APS and ALS to be used for synchrotron footprinting in a general user mode that can provide useful results. C1 [Bohon, Jen; D'Mello, Rhijuta; Chance, Mark R.] Case Western Reserve Univ, Ctr Synchrotron Biosci, Natl Synchrotron Light Source, Brookhaven Natl Lab, Upton, NY 11973 USA. [Bohon, Jen; D'Mello, Rhijuta; Chance, Mark R.] Case Western Reserve Univ, Ctr Prote & Bioinformat, Cleveland, OH 44106 USA. [Ralston, Corie; Gupta, Sayan] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley Ctr Struct Biol, Phys Biosci Div, Berkeley, CA 94720 USA. RP Bohon, J (reprint author), Case Western Reserve Univ, Ctr Synchrotron Biosci, Natl Synchrotron Light Source, Brookhaven Natl Lab, Upton, NY 11973 USA. EM jbohon@bnl.gov RI BM, MRCAT/G-7576-2011 FU National Institute for Biomedical Imaging and Bio-engineering [P30-EB-09998, R01-EB-09688]; National Science Foundation [DBI-1228549]; US Department of Energy, Office of Science, Office of Basic Energy Sciences [DE-AC02-98CH10886]; Office of Science, Office of Basic Energy Sciences, of the US Department of Energy [DE-AC02-05CH11231]; US DOE [DE-AC02-06CH11357]; National Institutes of Health/National Institute of General Medical Sciences under NSF [DMR-0936384] FX The authors would like to thank Mike Sullivan, John Toomey and Don Abel for expert technical support at the NSLS X28C beamline and fabrication of the capillary flow cell and mount. The authors would also like to acknowledge Rich Celestre (ALS 5.3.1), John Katsoudas (APS 10-BM-A), Dula Parkinson (ALS 8.3.2) and Jacob Ruff (CHESS A2) for significant assistance with the experimental set-up at the denoted beamlines. Funding for this research was supported by the National Institute for Biomedical Imaging and Bio-engineering under awards P30-EB-09998 and R01-EB-09688 and by the National Science Foundation under award DBI-1228549. Use of the National Synchrotron Light Source, Brookhaven National Laboratory, was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract No. DE-AC02-98CH10886. The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the US Department of Energy under contract No. DE-AC02-05CH11231. Use of the Advanced Photon Source, an Office of Science User Facility operated for the US Department of Energy (DOE) Office of Science by the Argonne National Laboratory, was supported by the US DOE under contract No. DE-AC02-06CH11357. Use of the Cornell High Energy Synchrotron Source (CHESS) is supported by the National Science Foundation and the National Institutes of Health/National Institute of General Medical Sciences under NSF award DMR-0936384. NR 36 TC 3 Z9 3 U1 1 U2 12 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0909-0495 EI 1600-5775 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD JAN PY 2014 VL 21 BP 24 EP 31 DI 10.1107/S1600577513024715 PN 1 PG 8 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 279DD UT WOS:000328939400004 PM 24365913 ER PT J AU Chen, S Deng, J Yuan, Y Flachenecker, C Mak, R Hornberger, B Jin, Q Shu, D Lai, B Maser, J Roehrig, C Paunesku, T Gleber, SC Vine, DJ Finney, L VonOsinski, J Bolbat, M Spink, I Chen, Z Steele, J Trapp, D Irwin, J Feser, M Snyder, E Brister, K Jacobsen, C Woloschak, G Vogt, S AF Chen, S. Deng, J. Yuan, Y. Flachenecker, C. Mak, R. Hornberger, B. Jin, Q. Shu, D. Lai, B. Maser, J. Roehrig, C. Paunesku, T. Gleber, S. C. Vine, D. J. Finney, L. VonOsinski, J. Bolbat, M. Spink, I. Chen, Z. Steele, J. Trapp, D. Irwin, J. Feser, M. Snyder, E. Brister, K. Jacobsen, C. Woloschak, G. Vogt, S. TI The Bionanoprobe: hard X-ray fluorescence nanoprobe with cryogenic capabilities SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE Bionanoprobe; hard X-ray fluorescence microscopy; cryogenic capabilities ID BIOLOGICAL APPLICATIONS; PHASE-CONTRAST; ZONE PLATES; MICROSCOPY; CELLS; SPECTROSCOPY; MICROPROBE; SPECIATION; BEAMLINE; XANES AB Hard X-ray fluorescence microscopy is one of the most sensitive techniques for performing trace elemental analysis of biological samples such as whole cells and tissues. Conventional sample preparation methods usually involve dehydration, which removes cellular water and may consequently cause structural collapse, or invasive processes such as embedding. Radiation-induced artifacts may also become an issue, particularly as the spatial resolution increases beyond the sub-micrometer scale. To allow imaging under hydrated conditions, close to the 'natural state', as well as to reduce structural radiation damage, the Bionanoprobe (BNP) has been developed, a hard X-ray fluorescence nanoprobe with cryogenic sample environment and cryo transfer capabilities, dedicated to studying trace elements in frozen-hydrated biological systems. The BNP is installed at an undulator beamline at sector 21 of the Advanced Photon Source. It provides a spatial resolution of 30 nm for two-dimensional fluorescence imaging. In this first demonstration the instrument design and motion control principles are described, the instrument performance is quantified, and the first results obtained with the BNP on frozen-hydrated whole cells are reported. C1 [Chen, S.; Shu, D.; Lai, B.; Maser, J.; Roehrig, C.; Gleber, S. C.; Vine, D. J.; Finney, L.; Jacobsen, C.; Vogt, S.] Argonne Natl Lab, Adv Photon Source, Xray Sci Div, Argonne, IL 60439 USA. [Deng, J.; Jacobsen, C.] Northwestern Univ, Evanston, IL 60208 USA. [Yuan, Y.; Paunesku, T.; Woloschak, G.] Northwestern Univ, Dept Radiat Oncol, Chicago, IL 60611 USA. [Flachenecker, C.; Hornberger, B.; Spink, I.; Chen, Z.; Steele, J.; Trapp, D.; Irwin, J.; Feser, M.; Snyder, E.] Xradia Inc, Pleasanton, CA 94588 USA. [Mak, R.; Jin, Q.; Jacobsen, C.] Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. [VonOsinski, J.; Bolbat, M.; Brister, K.] Northwestern Synchrotron Res Ctr, Argonne, IL 60439 USA. [Jacobsen, C.] Northwestern Univ, Chem Life Proc Inst, Evanston, IL 60208 USA. RP Chen, S (reprint author), Argonne Natl Lab, Adv Photon Source, Xray Sci Div, Argonne, IL 60439 USA. EM sichen@aps.anl.gov RI Jacobsen, Chris/E-2827-2015; Jin, Qiaoling/D-2303-2016; Vogt, Stefan/B-9547-2009; Vogt, Stefan/J-7937-2013; Paunesku, Tatjana/A-3488-2017; Woloschak, Gayle/A-3799-2017 OI Jacobsen, Chris/0000-0001-8562-0353; Vogt, Stefan/0000-0002-8034-5513; Vogt, Stefan/0000-0002-8034-5513; Paunesku, Tatjana/0000-0001-8698-2938; Woloschak, Gayle/0000-0001-9209-8954 FU ARRA: NIH/NCRR High End Instrumentation (HEI) [1S10RR029272-01]; NIH [2 R01 GM064846-05]; US Department of Energy [DE-AC02-06CH11357] FX We are grateful to Oleg Makarov, Sergey Stepanov (both at the APS) and Elena Kondrashkina (at LS-CAT) for extensive help with interfacing PMAC motion controllers from EPICS and utilizing the advanced PMAC capabilities. This research was made possible by ARRA: NIH/NCRR High End Instrumentation (HEI) grant 1S10RR029272-01. We thank NIH grant 2 R01 GM064846-05 for some of the cryogenic sample preparation equipment used. Argonne National Laboratory's work was supported under US Department of Energy contract DE-AC02-06CH11357. NR 59 TC 38 Z9 38 U1 5 U2 31 PU INT UNION CRYSTALLOGRAPHY PI CHESTER PA 2 ABBEY SQ, CHESTER, CH1 2HU, ENGLAND SN 1600-5775 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD JAN PY 2014 VL 21 BP 66 EP 75 DI 10.1107/S1600577513029676 PN 1 PG 10 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 279DD UT WOS:000328939400008 PM 24365918 ER PT J AU Hong, YP Gleber, SC O'Halloran, TV Que, EL Bleher, R Vogt, S Woodruff, TK Jacobsen, C AF Hong, Young Pyo Gleber, Sophie-Charlotte O'Halloran, Thomas V. Que, Emily L. Bleher, Reiner Vogt, Stefan Woodruff, Teresa K. Jacobsen, Chris TI Alignment of low-dose X-ray fluorescence tomography images using differential phase contrast SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE X-ray fluorescence tomography; differential phase contrast ID ELECTRON TOMOGRAPHY; MICROSCOPY; RECONSTRUCTION; DETECTOR; MICROPROBE; NOISE AB X-ray fluorescence nanotomography provides unprecedented sensitivity for studies of trace metal distributions in whole biological cells. Dose fractionation, in which one acquires very low dose individual projections and then obtains high statistics reconstructions as signal from a voxel is brought together (Hegerl & Hoppe, 1976), requires accurate alignment of these individual projections so as to correct for rotation stage runout. It is shown here that differential phase contrast at 10.2 keV beam energy offers the potential for accurate cross-correlation alignment of successive projections, by demonstrating that successive low dose, 3 ms per pixel, images acquired at the same specimen position and rotation angle have a narrower and smoother cross-correlation function (1.5 pixels FWHM at 300 nm pixel size) than that obtained from zinc fluorescence images (25 pixels FWHM). The differential phase contrast alignment resolution is thus well below the 700 nm x 500 nm beam spot size used in this demonstration, so that dose fractionation should be possible for reduced-dose, more rapidly acquired, fluorescence nanotomography experiments. C1 [Hong, Young Pyo; Jacobsen, Chris] Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. [Gleber, Sophie-Charlotte; Vogt, Stefan; Jacobsen, Chris] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. [O'Halloran, Thomas V.; Que, Emily L.] Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. [Bleher, Reiner] Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. [Woodruff, Teresa K.] Northwestern Univ, Dept Obstet & Gynecol, Chicago, IL 60611 USA. RP Hong, YP (reprint author), Northwestern Univ, Dept Phys & Astron, 2145 Sheridan Rd, Evanston, IL 60208 USA. EM younghong2015@u.northwestern.edu RI Jacobsen, Chris/E-2827-2015; Vogt, Stefan/B-9547-2009; Vogt, Stefan/J-7937-2013 OI Jacobsen, Chris/0000-0001-8562-0353; Vogt, Stefan/0000-0002-8034-5513; Vogt, Stefan/0000-0002-8034-5513 FU US Department of Energy (DOE) Office of Science [DE-AC02-06CH11357]; National Institutes of Health [P01 HD021921, R01 GM104530]; W. M. Keck Foundation FX We thank Christian Holzner, Michael Feser and Benjamin Hornberger for helpful discussions. We thank the US Department of Energy (DOE) Office of Science for support of this research under Contract No. DE-AC02-06CH11357 to Argonne National Laboratory, the National Institutes of Health for support under grants P01 HD021921 (TKW/TVO) and R01 GM104530 (CJ), and a Medical Research Award from the W. M. Keck Foundation (TVO/TKW). NR 33 TC 4 Z9 4 U1 1 U2 16 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0909-0495 EI 1600-5775 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD JAN PY 2014 VL 21 BP 229 EP 234 DI 10.1107/S1600577513029512 PN 1 PG 6 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 279DD UT WOS:000328939400031 PM 24365941 ER PT J AU Fusseis, F Steeb, H Xiao, XH Zhu, WL Butler, IB Elphick, S Mader, U AF Fusseis, Florian Steeb, Holger Xiao, Xianghui Zhu, Wen-lu Butler, Ian B. Elphick, Stephen Maeder, Urs TI A low-cost X-ray-transparent experimental cell for synchrotron-based X-ray microtomography studies under geological reservoir conditions SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE high-energy microtomography; in situ studies; porous media ID FLUID-FLOW; METAMORPHISM; PERMEABILITY; IMAGE; CRUST AB A new modular X-ray-transparent experimental cell enables tomographic investigations of fluid rock interaction under natural reservoir conditions (confining pressure up to 20 MPa, pore fluid pressure up to 15 MPa, temperature ranging from 296 to 473 K). The portable cell can be used at synchrotron radiation sources that deliver a minimum X-ray flux density of 10(9) photons mm(-2) s(-1) in the energy range 30-100 keV to acquire tomographic datasets in less than 60 s. It has been successfully used in three experiments at the bending-magnet beamline 2BM at the Advanced Photon Source. The cell can be easily machined and assembled from off-the-shelf components at relatively low costs, and its modular design allows it to be adapted to a wide range of experiments and lower-energy X-ray sources. C1 [Fusseis, Florian; Butler, Ian B.; Elphick, Stephen] Univ Edinburgh, Grant Inst, Sch Geosci, Edinburgh EH9 3JW, Midlothian, Scotland. [Steeb, Holger] Ruhr Univ Bochum, Inst Mech, Bochum, Germany. [Xiao, Xianghui] Argonne Natl Lab, Adv Photon Source, Beamline 2BM, Argonne, IL 60439 USA. [Zhu, Wen-lu] Univ Maryland, Dept Geol, College Pk, MD 20742 USA. [Maeder, Urs] Univ Bern, Inst Geol Sci, CH-3012 Bern, Switzerland. RP Fusseis, F (reprint author), Univ Edinburgh, Grant Inst, Sch Geosci, Kings Bldg,West Mains Rd, Edinburgh EH9 3JW, Midlothian, Scotland. EM florian.fusseis@ed.ac.uk RI Fusseis, Florian/M-5321-2016 OI Fusseis, Florian/0000-0002-3104-8109 FU US Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences [DE-AC02-06CH11357]; DOE [C11E10947] FX Use of the Advanced Photon Source at Argonne National Laboratory was supported by the US Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The olivine carbonation study was partially funded by DOE under grant DOE#C11E10947 (WZ). We thank Harrison Lisabeth for his participation in the olivine carbonation experiments at 2-BM. Tannaz Pak is thanked for preparation of and valuable advice during experiment (ii). Technical support by Thomas Siegenthaler, Stefan Seifert, Petra Nagel, Lothar Kuhne, Bob Brown and Alex Hard is gratefully acknowledged. NR 13 TC 8 Z9 8 U1 5 U2 21 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0909-0495 EI 1600-5775 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD JAN PY 2014 VL 21 BP 251 EP 253 DI 10.1107/S1600577513026969 PN 1 PG 3 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 279DD UT WOS:000328939400034 PM 24365944 ER PT J AU Xue, L Reininger, R Wu, YQ Zou, Y Xu, ZM Shi, YB Dong, J Ding, H Sun, JL Guo, FZ Wang, Y Tai, RZ AF Xue, L. Reininger, R. Wu, Y. -Q. Zou, Y. Xu, Z. -M. Shi, Y. -B. Dong, J. Ding, H. Sun, J. -L. Guo, F. -Z. Wang, Y. Tai, R. -Z. TI Design of an ultrahigh-energy-resolution and wide-energy-range soft X-ray beamline SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE soft X-ray beamline; ultrahigh-energy resolution; ARPES; thermal deformation ID SYNCHROTRON-RADIATION; ELECTRON-MICROSCOPY; SCATTERING; OPTICS AB A new ultrahigh-energy-resolution and wide-energy-range soft X-ray beamline has been designed and is under construction at the Shanghai Synchrotron Radiation Facility. The beamline has two branches: one dedicated to angle-resolved photoemission spectroscopy (ARPES) and the other to photoelectron emission microscopy (PEEM). The two branches share the same plane-grating monochromator, which is equipped with four variable-line-spacing gratings and covers the 20-2000 eV energy range. Two elliptically polarized undulators are employed to provide photons with variable polarization, linear in every inclination and circular. The expected energy resolution is approximately 10 meV at 1000 eV with a flux of more than 3 x 10(10) photons s(-1) at the ARPES sample positions. The refocusing of both branches is based on Kirkpatrick-Baez pairs. The expected spot sizes when using a 10 mu m exit slit are 15 mu m x 5 mu m (horizontal x vertical FWHM) at the ARPES station and 10 mu m x 5 mu m (horizontal x vertical FWHM) at the PEEM station. The use of plane optical elements upstream of the exit slit, a variable-line-spacing grating and a pre-mirror in the monochromator that allows the influence of the thermal deformation to be eliminated are essential for achieving the ultrahigh-energy resolution. C1 [Xue, L.; Wu, Y. -Q.; Zou, Y.; Xu, Z. -M.; Wang, Y.; Tai, R. -Z.] Chinese Acad Sci, Shanghai Inst Appl Phys, Shanghai 201800, Peoples R China. [Reininger, R.] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. [Shi, Y. -B.; Dong, J.; Ding, H.] Chinese Acad Sci, Inst Phys, Beijing 100190, Peoples R China. [Sun, J. -L.] Chinese Acad Sci, Dalian Inst Chem Phys, Dalian 116023, Peoples R China. [Guo, F. -Z.] Dalian Jiaotong Univ, Dalian, Peoples R China. RP Wang, Y (reprint author), Chinese Acad Sci, Shanghai Inst Appl Phys, Shanghai 201800, Peoples R China. EM wangyong@sinap.ac.cn; tairenzhong@sinap.ac.cn FU Major Scientific Equipment Project 'Photoemission instrument with ultrahigh energy resolution and wide energy range'; National Natural Science Foundation of China [11005146]; Large Scientific Facility from Chinese Academy of Sciences FX This work has been supported by the Major Scientific Equipment Project 'Photoemission instrument with ultrahigh energy resolution and wide energy range', the National Natural Science Foundation of China (No. 11005146) and the Open Research Project of Large Scientific Facility from Chinese Academy of Sciences 'Study on self-assembly technology and nanometer array with ultrahigh density'. We would like to acknowledge Dr Y. F. Hu (Canadian Light Source), Dr M. Shi, Dr V. N. Strocov and U. Flechsig (Paul Scherrer Institut), Professor Y. L. Yan and Professor H. J. Qian (Institute of High Energy Physics) for beneficial discussions. NR 22 TC 3 Z9 4 U1 4 U2 29 PU INT UNION CRYSTALLOGRAPHY PI CHESTER PA 2 ABBEY SQ, CHESTER, CH1 2HU, ENGLAND SN 1600-5775 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD JAN PY 2014 VL 21 BP 273 EP 279 DI 10.1107/S1600577513029093 PN 1 PG 7 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 279DD UT WOS:000328939400039 PM 24365949 ER PT J AU Marginean, I Tang, KQ Smith, RD Kelly, RT AF Marginean, Ioan Tang, Keqi Smith, Richard D. Kelly, Ryan T. TI Picoelectrospray Ionization Mass Spectrometry Using Narrow-Bore Chemically Etched Emitters SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article DE Nanoelectrospray; nano-ESI; Quantitation; Mass-limited analysis ID CAPILLARY-ZONE-ELECTROPHORESIS; HIGH-SENSITIVITY ANALYSIS; SINGLE-CELL ANALYSIS; ELECTROSPRAY-IONIZATION; LIQUID-CHROMATOGRAPHY; ION-SPRAY; NANOELECTROSPRAY IONIZATION; NANOFLOW REGIME; DYNAMIC-RANGE; BEVELED EDGE AB Electrospray ionization mass spectrometry (ESI-MS) at flow rates below similar to 10 nL/min has been only sporadically explored because of difficulty in reproducibly fabricating emitters that can operate at lower flow rates. Here we demonstrate narrow orifice chemically etched emitters for stable electrospray at flow rates as low as 400 pL/min. Depending on the analyte concentration, we observe two types of MS signal response as a function of flow rate. At low concentrations, an optimum flow rate is observed slightly above 1 nL/min, whereas the signal decreases monotonically with decreasing flow rates at higher concentrations. For example, consumption of 500 zmol of sample yielded signal-to-noise ratios similar to 10 for some peptides. In spite of lower MS signal, the ion utilization efficiency increases exponentially with decreasing flow rate in all cases. Significant variations in ionization efficiency were observed within this flow rate range for an equimolar mixture of peptide, indicating that ionization efficiency is an analyte-dependent characteristic for the present experimental conditions. Mass-limited samples benefit strongly from the use of low flow rates and avoiding unnecessary sample dilution. These findings have important implications for the analysis of trace biological samples. C1 [Marginean, Ioan; Tang, Keqi; Smith, Richard D.] Pacific NW Natl Lab, Div Biol Sci, Richland, WA 99352 USA. [Kelly, Ryan T.] Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Kelly, RT (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. EM ryan.kelly@pnnl.gov RI Smith, Richard/J-3664-2012; Marginean, Ioan/A-4183-2008; Kelly, Ryan/B-2999-2008 OI Smith, Richard/0000-0002-2381-2349; Marginean, Ioan/0000-0002-6693-0361; Kelly, Ryan/0000-0002-3339-4443 FU William R. Wiley Environmental Molecular Sciences Laboratory (EMSL) intramural program; National Institutes of Health: the National Institute of General Medical Sciences [8 P41 GM103493-10]; National Institutes of Health: National Cancer Institute [1R33CA155252]; US DOE's Office of Biological and Environmental Research; DOE [DE-AC05-76RLO 1830] FX The authors thank William F. Danielson for writing the syringe pump control software, and Sarah Rausch, Allison Sheen, and Levi Broeske for assistance with data processing. This research was supported by the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL) intramural program and grants from National Institutes of Health: the National Institute of General Medical Sciences (grant 8 P41 GM103493-10) and the National Cancer Institute (1R33CA155252). The EMSL is a national scientific user facility sponsored by US DOE's Office of Biological and Environmental Research and located at the Pacific Northwest National Laboratory (PNNL) in Richland, WA. PNNL is a multiprogram national laboratory operated by Battelle for the DOE under contract no. DE-AC05-76RLO 1830. NR 46 TC 12 Z9 12 U1 2 U2 52 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1044-0305 EI 1879-1123 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD JAN PY 2014 VL 25 IS 1 BP 30 EP 36 DI 10.1007/s13361-013-0749-z PG 7 WC Biochemical Research Methods; Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Biochemistry & Molecular Biology; Chemistry; Spectroscopy GA 283IL UT WOS:000329239600005 PM 24122304 ER PT J AU Hardy, F Eder, R Jackson, M Aoki, D Paulsen, C Wolf, T Burger, P Bohmer, A Schweiss, P Adelmann, P Fisher, RA Meingast, C AF Hardy, Frederic Eder, Robert Jackson, Martin Aoki, Dai Paulsen, Carley Wolf, Thomas Burger, Philipp Boehmer, Anna Schweiss, Peter Adelmann, Peter Fisher, Robert A. Meingast, Christoph TI Multiband Superconductivity in KFe2As2: Evidence for One Isotropic and Several Lilliputian Energy Gaps SO JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN LA English DT Article ID REVERSIBLE MAGNETIZATION; HEAT; BA0.6K0.4FE2AS2 AB We report a detailed low-temperature thermodynamic investigation (heat capacity and magnetization) of the superconducting state of KFe2As2 for H parallel to c axis. Our measurements reveal that the properties of KFe2As2 are dominated by a relatively large nodeless energy gap (Delta(0) = 1.9 k(B)T(c)) which excludes d(x2-y2) symmetry. We prove the existence of several additional extremely small gaps (Delta(0) < 1.0 k(B)T(c)) that have a profound impact on the low-temperature and low-field behavior, similar to MgB2, CeCoIn5, and PrOs4Sb12. The zero-field heat capacity is analyzed in a realistic self-consistent 4-band BCS model which reproduces only qualitatively the recent laser ARPES results of Okazaki et al. [Science 337, 1314 (2012)]. Our results show that extremely low-temperature measurements, i.e., T < 0.1 K, are required in order to resolve the question of the existence of line nodes in this compound. C1 [Hardy, Frederic; Eder, Robert; Wolf, Thomas; Burger, Philipp; Boehmer, Anna; Schweiss, Peter; Adelmann, Peter; Meingast, Christoph] Karlsruher Inst Technol, Inst Festkorperphys, D-76021 Karlsruhe, Germany. [Jackson, Martin; Paulsen, Carley] CNRS, MCBT Dept, Inst Neel, F-38042 Grenoble 9, France. [Jackson, Martin; Paulsen, Carley] Univ Grenoble 1, F-38042 Grenoble 9, France. [Aoki, Dai] CEA Grenoble, INAC SPSMS, F-38054 Grenoble 9, France. [Aoki, Dai] Tohoku Univ, IMR, Oarai, Ibaraki 3111313, Japan. [Fisher, Robert A.] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Hardy, F (reprint author), Karlsruher Inst Technol, Inst Festkorperphys, D-76021 Karlsruhe, Germany. EM frederic.hardy@kit.edu RI Aoki, Dai/K-3673-2012; Jackson, Martin/N-2481-2013 OI Aoki, Dai/0000-0003-2334-8360; Jackson, Martin/0000-0001-7862-3476 FU Deutsche Forschungsgemeinschaft [DFG-SPP 1458]; French ANR; ERC FX We thank J.-P. Brison, M. Lang, M. Ichioka, K. Machida, A. Chubukov, T. Shibauchi, and S. Kittaka for stimulating and enlightening discussions. This work was supported by the Deutsche Forschungsgemeinschaft through DFG-SPP 1458 "Hochtemperatursupraleitung in Eisenpniktiden". The work performed in Grenoble was supported by the French ANR Projects (SINUS and CHIRnMAG) and the ERC starting grant NewHeavyFermion. NR 57 TC 18 Z9 18 U1 2 U2 36 PU PHYSICAL SOC JAPAN PI TOKYO PA YUSHIMA URBAN BUILDING 5F, 2-31-22 YUSHIMA, BUNKYO-KU, TOKYO, 113-0034, JAPAN SN 0031-9015 J9 J PHYS SOC JPN JI J. Phys. Soc. Jpn. PD JAN PY 2014 VL 83 IS 1 AR 014711 DI 10.7566/JPSJ.83.014711 PG 7 WC Physics, Multidisciplinary SC Physics GA 281UC UT WOS:000329125500028 ER PT J AU White, M Tinker, JL McBride, CK AF White, Martin Tinker, Jeremy L. McBride, Cameron K. TI Mock galaxy catalogues using the quick particle mesh method SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE galaxies: haloes; galaxies: statistics; cosmological parameters; large-scale structure of Universe ID BARYON ACOUSTIC-OSCILLATIONS; LARGE-SCALE STRUCTURE; LAGRANGIAN PERTURBATION-THEORY; HALO OCCUPATION DISTRIBUTION; DARK-MATTER HALOS; SPECTROSCOPIC SURVEY; SDSS-III; GRAVITATIONAL-INSTABILITY; COSMOLOGICAL CONSTRAINTS; ADHESION APPROXIMATION AB Sophisticated analysis of modern large-scale structure surveys requires mock catalogues. Mock catalogues are used to optimize survey design, test reduction and analysis pipelines, make theoretical predictions for basic observables and propagate errors through complex analysis chains. We present a new method, which we call 'quick particle mesh', for generating many large volume, approximate mock catalogues at low computational cost. The method is based on using rapid, low-resolution particle mesh simulations that accurately reproduce the large-scale dark matter density field. Particles are sampled from the density field based on their local density such that they have N-point statistics nearly equivalent to the haloes resolved in high-resolution simulations, creating a set of mock haloes that can be populated using halo occupation methods to create galaxy mocks for a variety of possible target classes. C1 [White, Martin] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. [White, Martin] Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. [White, Martin] Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. [Tinker, Jeremy L.] NYU, Dept Phys, Ctr Cosmol & Particle Phys, New York, NY 10003 USA. [McBride, Cameron K.] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP White, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM mwhite@berkeley.edu RI White, Martin/I-3880-2015 OI White, Martin/0000-0001-9912-5070 FU NSF; NASA FX The simulations used in this paper were analysed at the National Energy Research Scientific Computing Center. MW is supported by the NSF and NASA. NR 80 TC 38 Z9 38 U1 1 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0035-8711 EI 1365-2966 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JAN PY 2014 VL 437 IS 3 BP 2594 EP 2606 DI 10.1093/mnras/stt2071 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 282GQ UT WOS:000329158900043 ER PT J AU Tchekhovskoy, A Metzger, BD Giannios, D Kelley, LZ AF Tchekhovskoy, Alexander Metzger, Brian D. Giannios, Dimitrios Kelley, Luke Z. TI Swift J1644+57 gone MAD: the case for dynamically important magnetic flux threading the black hole in a jetted tidal disruption event SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE accretion; accretion discs; black hole physics; MHD; gamma-rays: galaxies; X-rays: galaxies ID GAMMA-RAY BURSTS; RELATIVISTIC JETS; ACCRETION FLOWS; WHITE-DWARF; MAGNETOHYDRODYNAMIC SIMULATIONS; RADIATION PRESSURE; NEARBY GALAXIES; RADIO JETS; STARS; DISK AB The unusual transient Swift J1644+57 likely resulted from a collimated relativistic jet, powered by the sudden onset of accretion on to a massive black hole (BH) following the tidal disruption (TD) of a star. However, several mysteries cloud the interpretation of this event, including (1) the extreme flaring and 'plateau' shape of the X-ray/gamma-ray light curve during the first t - t(trig) similar to 10 d after the gamma-ray trigger; (2) unexpected rebrightening of the forward shock radio emission at t - t(trig) similar to months; (3) lack of obvious evidence for jet precession, despite the misalignment typically expected between the angular momentum of the accretion disc and BH; (4) recent abrupt shut-off in the jet X-ray emission at t - t(trig) similar to 1.5 yr. Here, we show that all of these seemingly disparate mysteries are naturally resolved by one assumption: the presence of strong magnetic flux Phi(center dot) threading the BH. Just after the TD event, Phi(center dot) is dynamically weak relative to the high rate of fall-back accretion <(M)over dot>, such that the accretion disc (jet) freely precesses about the BH axis = our line of sight. As <(M)over dot> decreases, however, Phi(center dot) becomes dynamically important, leading to a state of 'magnetically arrested disk' (MAD). MAD naturally aligns the jet with the BH spin, but only after an extended phase of violent rearrangement (jet wobbling), which in Swift J1644+57 starts a few days before the gamma-ray trigger and explains the erratic early light curve. Indeed, the entire X-ray light curve can be fitted to the predicted power-law decay <(M)over dot> (alpha similar or equal to 5/3 - 2.2) if the TD occurred a few weeks prior to the gamma-ray trigger. Jet energy directed away from the line of sight, either prior to the trigger or during the jet alignment process, eventually manifests as the observed radio rebrightening, similar to an off-axis (orphan) gamma-ray burst afterglow. As suggested recently, the late X-ray shut-off occurs when the disc transitions to a geometrically thin (jetless) state once <(M)over dot> drops below similar to the Eddington rate. We predict that, in several years, a transition to a low/hard state will mark a revival of the jet and its associated X-ray emission. We use our model for Swift J1644+57 to constrain the properties of the BH and disrupted star, finding that a solar mass main-sequence star disrupted by a relatively low-mass M-center dot similar to 10(5)-10(6) M-circle dot BH is consistent with the data, while a white dwarf disruption (though still possible) is disfavoured. The magnetic flux required to power Swift J1644+57 is much too large to be supplied by the star itself, but it could be collected from a quiescent 'fossil' accretion disc that was present in the galactic nucleus prior to the TD. The presence (lack of) of such a fossil disc could be a deciding factor in what TD events are accompanied by powerful jets. C1 [Tchekhovskoy, Alexander] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. [Tchekhovskoy, Alexander] Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. [Metzger, Brian D.] Columbia Univ, Dept Phys, New York, NY 10027 USA. [Giannios, Dimitrios] Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. [Kelley, Luke Z.] Harvard Univ, Dept Astron, Cambridge, MA 02138 USA. [Tchekhovskoy, Alexander] Princeton Univ, Ctr Theoret Sci, Princeton, NJ 08544 USA. RP Tchekhovskoy, A (reprint author), NASA, Washington, DC USA. EM atchekho@berkeley.edu FU Princeton Center for Theoretical Science fellowship; NASA through Einstein Postdoctoral Fellowship [PF3-140115]; Chandra X-ray Center; NASA [NAS8-03060] FX We thank Binbin Zhang, David Burrows, Michael Eracleous, Jonathan Granot, James Guillochon, Michael Kesden, Serguei Komissarov, Julian Krolik, Pawan Kumar, Morgan MacLeod, Jonathan C. McKinney, Petar Mimica, Ramesh Narayan, Ryan O'Leary, Asaf Pe'er, Tsvi Piran, Enrico Ramirez-Ruiz, Eliot Quataert, Roman Shcherbakov, Steinn Sigurdsson, Nicholas Stone and Sjoert van Velzen for insightful discussions. We thank the anonymous referee for suggestions that helped improve the manuscript. AT was supported by a Princeton Center for Theoretical Science fellowship, by NASA through Einstein Postdoctoral Fellowship grant number PF3-140115 awarded by the Chandra X-ray Center, which is operated by the Smithsonian Astrophysical Observatory for NASA under contract NAS8-03060, and an XSEDE computational time allocation TG-AST100040 on NICS Kraken and Nautilus and TACC Ranch. NR 73 TC 42 Z9 42 U1 0 U2 3 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0035-8711 EI 1365-2966 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JAN PY 2014 VL 437 IS 3 BP 2744 EP 2760 DI 10.1093/mnras/stt2085 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 282GQ UT WOS:000329158900055 ER PT J AU Agarwal, B Khochfar, S Johnson, JL Neistein, E Vecchia, CD Livio, M AF Agarwal, Bhaskar Khochfar, Sadegh Johnson, Jarrett L. Neistein, Eyal Vecchia, Claudio Dalla Livio, Mario TI Ubiquitous seeding of supermassive black holes by direct collapse (vol 425, pg 2854, 2012) SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Correction DE errata; addenda; methods: numerical; cosmology: theory; early Universe C1 [Agarwal, Bhaskar; Khochfar, Sadegh; Johnson, Jarrett L.; Neistein, Eyal; Vecchia, Claudio Dalla] Max Planck Inst Extraterr Phys, Theoret Modeling Cosm Struct Grp, D-85748 Garching, Germany. [Johnson, Jarrett L.] Los Alamos Natl Lab, Nucl & Particle Phys Astrophys & Cosmol Grp T2, Los Alamos, NM 87545 USA. [Livio, Mario] Space Telescope Sci Inst, Baltimore, MD 21218 USA. RP Agarwal, B (reprint author), Max Planck Inst Extraterr Phys, Theoret Modeling Cosm Struct Grp, Giessenbachstr, D-85748 Garching, Germany. EM agarwalb@mpe.mpg.de NR 1 TC 1 Z9 1 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0035-8711 EI 1365-2966 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JAN PY 2014 VL 437 IS 3 BP 3024 EP 3024 DI 10.1093/mnras/stt2143 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 282GQ UT WOS:000329158900079 ER PT J AU Bernal, GM LaRiviere, MJ Mansour, N Pytel, P Cahill, KE Voce, DJ Kang, SJ Spretz, R Welp, U Noriega, SE Nunez, L Larsen, G Weichselbaum, RR Yamini, B AF Bernal, Giovanna M. LaRiviere, Michael J. Mansour, Nassir Pytel, Peter Cahill, Kirk E. Voce, David J. Kang, Shijun Spretz, Ruben Welp, Ulrich Noriega, Sandra E. Nunez, Luis Larsen, Gustavo Weichselbaum, Ralph R. Yamini, Bakhtiar TI Convection-enhanced delivery and in vivo imaging of polymeric nanoparticles for the treatment of malignant glioma SO NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE LA English DT Article DE Nanoparticle; Glioma; MRI; Convection ID IRON-OXIDE NANOPARTICLES; GLIOBLASTOMA; BRAIN; THERAPY; TEMOZOLOMIDE; SYSTEM; TUMOR; TRIAL AB A major obstacle to the management of malignant glioma is the inability to effectively deliver therapeutic agent to the tumor. In this study, we describe a polymeric nanoparticle vector that not only delivers viable therapeutic, but can also be tracked in vivo using MRI. Nanoparticles, produced by a non-emulsion technique, were fabricated to carry iron oxide within the shell and the chemotherapeutic agent, temozolomide (TMZ), as the payload. Nanoparticle properties were characterized and subsequently their endocytosis-mediated uptake by glioma cells was demonstrated. Convection-enhanced delivery (CED) can disperse nanoparticles through the rodent brain and their distribution is accurately visualized by MRI. Infusion of nanoparticles does not result in observable animal toxicity relative to control. CED of TMZ-bearing nanoparticles prolongs the survival of animals with intracranial xenografts compared to control. In conclusion, the described nanoparticle vector represents a unique multifunctional platform that can be used for image-guided treatment of malignant glioma. From the Clinical Editor: GBM remains one of the most notoriously treatment-unresponsive cancer types. In this study, a multifunctional nanoparticle-based temozolomide delivery system was demonstrated to possess enhanced treatment efficacy in a rodent xenograft GBM model, with the added benefit of MRI-based tracking via the incorporation of iron oxide as a T2* contrast material in the nanoparticles. (C) 2014 Elsevier Inc. All rights reserved. C1 [Bernal, Giovanna M.; LaRiviere, Michael J.; Mansour, Nassir; Cahill, Kirk E.; Voce, David J.; Kang, Shijun; Yamini, Bakhtiar] Univ Chicago, Dept Surg, Neurosurg Sect, Chicago, IL 60637 USA. [Pytel, Peter] Univ Chicago, Dept Pathol, Chicago, IL 60637 USA. [Weichselbaum, Ralph R.] Univ Chicago, Pritzker Sch Med, Dept Radiat & Cellular Oncol, Chicago, IL 60637 USA. [Spretz, Ruben; Noriega, Sandra E.; Nunez, Luis; Larsen, Gustavo] Biotarget Inc, Lincoln, NE USA. [Spretz, Ruben; Noriega, Sandra E.; Nunez, Luis; Larsen, Gustavo] LNK Chemsolut LLC, Lincoln, NE USA. [Welp, Ulrich] Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Yamini, B (reprint author), Univ Chicago Hosp, Neurosurg Sect, MC 3026, Chicago, IL 60637 USA. EM byamini@surgery.bsd.uchicago.edu FU NIH [R44CA135906-02, 1R01CA136937]; Ludwig Center for Metastasis Research FX This work was supported by NIH R44CA135906-02 (R.S., L.N. and B.Y.), NIH 1R01CA136937 (B.Y.) and the Ludwig Center for Metastasis Research. NR 29 TC 27 Z9 28 U1 6 U2 25 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1549-9634 EI 1549-9642 J9 NANOMED-NANOTECHNOL JI Nanomed.-Nanotechnol. Biol. Med. PD JAN PY 2014 VL 10 IS 1 BP 149 EP 157 DI 10.1016/j.nano.2013.07.003 PG 9 WC Nanoscience & Nanotechnology; Medicine, Research & Experimental SC Science & Technology - Other Topics; Research & Experimental Medicine GA 281LR UT WOS:000329103500016 PM 23891990 ER PT J AU Agnoli, S Reeder, AE Senanayake, SD Hrbek, J Rodriguez, JA AF Agnoli, Stefano Reeder, Askia E. Senanayake, Sanjaya D. Hrbek, Jan Rodriguez, Jose A. TI Structure and special chemical reactivity of interface-stabilized cerium oxide nanolayers on TiO2(110) SO NANOSCALE LA English DT Article ID MODEL CATALYST SURFACE; GAS SHIFT REACTION; MIXED-METAL OXIDE; METHANOL-OXIDATION; LOW-TEMPERATURE; VANADIUM-OXIDE; RUTILE TIO2(110); ULTRATHIN FILMS; NANOMETER LEVEL; MODIFIED TIO2 AB Novel interface-stabilized ceria nanophases have been grown on TiO2(110) by physical vapor deposition. At low coverage, dumbbell nanostructures constituted by reconstructed titania and ceria clusters are formed, while long range ordered nanoxides can be obtained by increasing the ceria dose. Scanning tunneling microscopy and photoemission spectroscopy were used to characterize the electronic properties of the films, showing that the TiO2 substrate can effectively stabilize ceria in reduced form over a wide range of experimental conditions. Epitaxial coupling is a very useful tool for tuning the chemical properties of mixed oxide systems. The special electronic properties of the films have a direct counterpart in the chemical activity, which has been investigated by temperature programmed desorption using methanol as a probe molecule. The experimental results indicate an exceptional activity of the ceria-titania interface in the selective dehydration of methanol to formaldehyde at an unprecedented low temperature (330 K). C1 [Agnoli, Stefano; Reeder, Askia E.] Univ Padua, Dept Chem Sci, I-35131 Padua, Italy. [Senanayake, Sanjaya D.; Hrbek, Jan; Rodriguez, Jose A.] Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Agnoli, S (reprint author), Univ Padua, Dept Chem Sci, Via F Marzolo 1, I-35131 Padua, Italy. EM stefano.agnoli@unipd.it RI Senanayake, Sanjaya/D-4769-2009 OI Senanayake, Sanjaya/0000-0003-3991-4232 FU US Department of Energy, Chemical Sciences Division [DE-AC02-98CH10886]; Italian MIUR through FIRB [RBAP115AYN] FX The research carried out at Brookhaven National Laboratory was supported by the US Department of Energy, Chemical Sciences Division (DE-AC02-98CH10886). The work performed at the University of Padova has been supported by the Italian MIUR through the FIRB Project RBAP115AYN 'Oxides at the nanoscale: multifunctionality and applications'. NR 76 TC 7 Z9 7 U1 3 U2 48 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 2040-3364 EI 2040-3372 J9 NANOSCALE JI Nanoscale PY 2014 VL 6 IS 2 BP 800 EP 810 DI 10.1039/c3nr04623k PG 11 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 278LR UT WOS:000328892300024 PM 24257903 ER PT J AU Venkatesan, S Adhikari, N Chen, JH Ngo, EC Dubey, A Galipeau, DW Qiao, QQ AF Venkatesan, Swaminathan Adhikari, Nirmal Chen, Jihua Ngo, Evan C. Dubey, Ashish Galipeau, David W. Qiao, Qiquan TI Interplay of nanoscale domain purity and size on charge transport and recombination dynamics in polymer solar cells SO NANOSCALE LA English DT Article ID HETEROJUNCTION ORGANIC PHOTOVOLTAICS; BULK-HETEROJUNCTION; THIN-FILMS; PERFORMANCE; EVOLUTION; NANOPARTICLES; BLENDS; ORDER AB Charge transport and bimolecular recombination dynamics were correlated with nanomorphology in polymer solar cells. The morphology of poly(diketopyrrolopyrrole-terthiophene) (PDPP3T) and phenyl-C61-butyric acid methyl ester (PC60BM) blend films was modified using different solvent additives namely 1-chloronaphthalene (CN), 1,8-diiodooctane (DIO) and 1,8-octanedithiol (ODT) and their role on steady state and transient optoelectronic properties was investigated. The energy filtered transmission electron microscopy (EFTEM) images showed that additives (e. g. CN and DIO) improved the domain purity which leads to significantly higher short circuit current densities (J(sc)). However when the cells were processed with the ODT additive, the fill factor (FF) and open circuit voltage (V-oc) decreased dramatically. Films processed with the ODT additive showed a smaller domain size but were more connected compared to films processed using CN and DIO additives. Transient photocurrent analysis indicates faster charge collection in the case of CN and DIO processed solar cells and the slowest charge collection in ODT processed solar cells. Interestingly devices processed with the ODT additive also showed the longest charge carrier recombination lifetime and lowest bimolecular recombination coefficient. This is attributed to the smaller donor domains that are connected with each other to provide a more interconnected and efficient charge transport matrix but longer pathways in ODT films. Such a matrix helped the charge to escape from the donor-acceptor interfaces and thus reduces the bimolecular recombination, while the longer pathway increases the charge collection time. Further insight is provided into the selection of processing conditions to achieve an ideal active layer morphology consisting of domains with higher polymer purity and optimal size that lead to higher Jsc and FF. C1 [Venkatesan, Swaminathan; Adhikari, Nirmal; Ngo, Evan C.; Dubey, Ashish; Galipeau, David W.; Qiao, Qiquan] S Dakota State Univ, Dept Elect Engn, Ctr Adv Photovolta, Brookings, SD 57007 USA. [Chen, Jihua] Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Oak Ridge, TN 37831 USA. RP Qiao, QQ (reprint author), S Dakota State Univ, Dept Elect Engn, Ctr Adv Photovolta, Brookings, SD 57007 USA. EM qiquan.qiao@sdstate.edu RI Venkatesan, Swaminathan/D-8809-2014; Chen, Jihua/F-1417-2011; Dubey, Ashish/E-8631-2015 OI Venkatesan, Swaminathan/0000-0003-2213-0255; Chen, Jihua/0000-0001-6879-5936; Dubey, Ashish/0000-0003-1955-2537 FU NASA EPSCoR [NNX13AD31A]; NSF CAREER [ECCS-0950731]; NSF EPSCoR [0903804]; SD BoR CRGP; Oak Ridge National Laboratory by the Division of Scientific User Facilities, Office of Basic Energy Sciences, U.S. Department of Energy FX We acknowledge the support from NASA EPSCoR (NNX13AD31A), NSF CAREER (ECCS-0950731), NSF EPSCoR (grant no. 0903804), and SD BoR CRGP. A portion of this research was conducted at the Center for Nanophase Materials Sciences, which was sponsored at Oak Ridge National Laboratory by the Division of Scientific User Facilities, Office of Basic Energy Sciences, U.S. Department of Energy. NR 34 TC 32 Z9 32 U1 2 U2 55 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 2040-3364 EI 2040-3372 J9 NANOSCALE JI Nanoscale PY 2014 VL 6 IS 2 BP 1011 EP 1019 DI 10.1039/c3nr05177c PG 9 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 278LR UT WOS:000328892300051 PM 24292406 ER PT J AU Harry, KJ Hallinan, DT Parkinson, DY MacDowell, AA Balsara, NP AF Harry, Katherine J. Hallinan, Daniel T. Parkinson, Dilworth Y. MacDowell, Alastair A. Balsara, Nitash P. TI Detection of subsurface structures underneath dendrites formed on cycled lithium metal electrodes SO NATURE MATERIALS LA English DT Article ID BLOCK-COPOLYMER ELECTROLYTES; POLYMER ELECTROLYTES; LITHIUM/POLYMER CELLS; GEL ELECTROLYTES; MOLECULAR-WEIGHT; LI BATTERIES; GROWTH; MECHANISMS; CHALLENGES; ANODES AB Failure caused by dendrite growth in high-energy-density, rechargeable batteries with lithium metal anodes has prevented their widespread use in applications ranging from consumer electronics to electric vehicles. Efforts to solve the lithium dendrite problem have focused on preventing the growth of protrusions from the anode surface. Synchrotron hard X-ray microtomography experiments on symmetric lithium-polymer-lithium cells cycled at 90 degrees C show that during the early stage of dendrite development, the bulk of the dendritic structure lies within the electrode, underneath the polymer/electrode interface. Furthermore, we observed crystalline impurities, present in the uncycled lithium anodes, at the base of the subsurface dendritic structures. The portion of the dendrite protruding into the electrolyte increases on cycling until it spans the electrolyte thickness, causing a short circuit. Contrary to conventional wisdom, it seems that preventing dendrite formation in polymer electrolytes depends on inhibiting the formation of subsurface structures in the lithium electrode. C1 [Harry, Katherine J.] Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. [Harry, Katherine J.; Balsara, Nitash P.] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. [Hallinan, Daniel T.; Balsara, Nitash P.] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. [Parkinson, Dilworth Y.; MacDowell, Alastair A.] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Adv Light Source Div, Berkeley, CA 94720 USA. [Balsara, Nitash P.] Univ Calif Berkeley, Dept Chem & Biomol Engn, Berkeley, CA 94720 USA. RP Balsara, NP (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. EM nbalsara@berkeley.edu RI Parkinson, Dilworth/A-2974-2015; OI Parkinson, Dilworth/0000-0002-1817-0716; Hallinan, Daniel/0000-0002-3819-0992 FU Electron Microscopy of Soft Matter Program from the Office of Science,Office of Basic Energy Sciences, Materials Sciences and Engineering Division of the US Department of Energy [DE-AC02-05CH11231]; BATT programme from the Vehicle Technologies programme,through the Office of Energy Efficiency and Renewable Energy [DE-AC02-05CH11231]; Director,Office of Science,Office of Basic Energy Sciences,of the US Department of Energy [DE-AC02-05CH11231]; National Science Foundation Graduate Research Fellowship FX Primary financial support for the work was provided by the Electron Microscopy of Soft Matter Program from the Office of Science,Office of Basic Energy Sciences, Materials Sciences and Engineering Division of the US Department of Energy under Contract No. DE-AC02-05CH11231 and the BATT programme from the Vehicle Technologies programme,through the Office of Energy Efficiency and Renewable Energy under US DOE Contract DE-AC02-05CH11231. Hard X-ray microtomography experiments were performed at the Advanced Light Source,which is supported by the Director,Office of Science,Office of Basic Energy Sciences,of the US Department of Energy under Contract No. DE-AC02-05CH11231. K.J.H. was supported by a National Science Foundation Graduate Research Fellowship. NR 36 TC 98 Z9 99 U1 48 U2 327 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 1476-1122 EI 1476-4660 J9 NAT MATER JI Nat. Mater. PD JAN PY 2014 VL 13 IS 1 BP 69 EP 73 DI 10.1038/NMAT3793 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 279EI UT WOS:000328942800021 PM 24270584 ER PT J AU Ievlev, AV Jesse, S Morozovska, AN Strelcov, E Eliseev, EA Pershin, YV Kumar, A Shur, VY Kalinin, SV AF Ievlev, A. V. Jesse, S. Morozovska, A. N. Strelcov, E. Eliseev, E. A. Pershin, Y. V. Kumar, A. Shur, V. Ya. Kalinin, S. V. TI Intermittency, quasiperiodicity and chaos in probe-induced ferroelectric domain switching SO NATURE PHYSICS LA English DT Article ID FORCE MICROSCOPY; SURFACE; NANOSCALE; MULTIFERROICS; CONDUCTION; SYSTEMS; FILMS AB Memristive materials and devices, which enable information storage and processing on one and the same physical platform, offer an alternative to conventional von Neumann computation architectures. Their continuous spectra of states with intricate field-history dependence give rise to complex dynamics, the spatial aspect of which has not been studied in detail yet. Here, we demonstrate that ferroelectric domain switching induced by a scanning probe microscopy tip exhibits rich pattern dynamics, including intermittency, quasiperiodicity and chaos. These effects are due to the interplay between tip-induced polarization switching and screening charge dynamics, and can be mapped onto the logistic map. Our findings may have implications for ferroelectric storage, nanostructure fabrication and transistor-less logic. C1 [Ievlev, A. V.; Shur, V. Ya.] Ural Fed Univ, Inst Nat Sci, Ferroelect Lab, Ekaterinburg 620000, Russia. [Ievlev, A. V.; Jesse, S.; Strelcov, E.; Kumar, A.; Kalinin, S. V.] Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Oak Ridge, TN 37922 USA. [Morozovska, A. N.] Natl Acad Sci Ukraine, Inst Phys, UA-03028 Kiev, Ukraine. [Eliseev, E. A.] Natl Acad Sci Ukraine, Inst Problems Mat Sci, UA-03142 Kiev, Ukraine. [Pershin, Y. V.] Univ S Carolina, Dept Phys & Astron, Columbia, SC 29208 USA. [Pershin, Y. V.] Univ S Carolina, Nanoctr, Columbia, SC 29208 USA. [Kumar, A.] Queens Univ Belfast, Sch Math & Phys, Ctr Nanostruct Media, Belfast BT7 1NN, Antrim, North Ireland. RP Shur, VY (reprint author), Ural Fed Univ, Inst Nat Sci, Ferroelect Lab, Ekaterinburg 620000, Russia. EM shur@labfer.ru; sergei2@ornl.gov RI Kumar, Amit/C-9662-2012; Strelcov, Evgheni/H-1654-2013; Kalinin, Sergei/I-9096-2012; Jesse, Stephen/D-3975-2016; Ievlev, Anton/H-3678-2012 OI Kumar, Amit/0000-0002-1194-5531; Kalinin, Sergei/0000-0001-5354-6152; Jesse, Stephen/0000-0002-1168-8483; Ievlev, Anton/0000-0003-3645-0508 FU Oak Ridge National Laboratory; Scientific User Facilities Division,Office of Basic Energy Sciences, US Department of Energy; RFBR [11-02-91066-CNRS-a, 13-02-01391-a, 13-02-96041-r-Ural-a]; Ministry of Education and Science [14.513.12.0006]; National Science Foundation grant [ECCS-1202383]; US National Science Foundation [NSF-DMR-1210588]; State Fund of Fundamental State Fund of Fundamental Research of Ukraine [UU48/002] FX Apart of this research (S.J., E.S., A.K., S.V.K.) was conducted at the Center for Nanophase Materials Sciences, which is sponsored at Oak Ridge National Laboratory by the Scientific User Facilities Division,Office of Basic Energy Sciences, US Department of Energy. A.V.I. and V.Y.S. acknowledge CNMS user proposal, RFBR (Grants 11-02-91066-CNRS-a, 13-02-01391-a, 13-02-96041-r-Ural-a), Ministry of Education and Science (Contract 14.513.12.0006). Y.V.P. was supported by National Science Foundation grant ECCS-1202383. The authors gratefully acknowledge Y.Wu (Tufts University) for posting the original version of the chaos analysis codes on the Math Works website. A.N.M. and E.A.E. acknowledge the support through the bilateral SFFR-NSF project (US National Science Foundation under NSF-DMR-1210588 and State Fund of Fundamental State Fund of Fundamental Research of Ukraine, grant UU48/002). We gratefully acknowledge A.K. Tagantsev (EPFL) for valuable advice on the role of screening phenomena on ferroelectric phase stability, and B.Sumpter and S.Pennycook (ORNL) for illuminating discussions. S.V.K. and V.Y.S. would like to acknowledge many useful discussions with the late Y.D. Tretyakov (Moscow State University, Russia), who introduced them to the field of chaos and fractals in solid-state systems and inspired this work, and dedicate this paper to him in memoriam. NR 40 TC 46 Z9 46 U1 3 U2 93 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 1745-2473 EI 1745-2481 J9 NAT PHYS JI Nat. Phys. PD JAN PY 2014 VL 10 IS 1 BP 59 EP 66 DI 10.1038/NPHYS2796 PG 8 WC Physics, Multidisciplinary SC Physics GA 279DJ UT WOS:000328940100018 ER PT J AU He, ZR Chen, JH Keum, JK Szulczewski, G Li, DW AF He, Zhengran Chen, Jihua Keum, Jong Kahk Szulczewski, Greg Li, Dawen TI Improving performance of TIPS pentacene-based organic thin film transistors with small-molecule additives SO ORGANIC ELECTRONICS LA English DT Article DE TIPS pentacene-small molecule blends; Interfacial layer; Crystal anisotropy; Thin film coverage; Organic thin-film transistors ID FIELD EFFECT TRANSISTORS; FUNCTIONALIZED PENTACENE; SEMICONDUCTORS; STABILITY AB This work demonstrates an effective approach to improve both charge transport and performance consistency in solution-processed organic thin-film transistors (OTFTs) by blending 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS pentacene, or TP) with a series of small-molecule additives: 4-butylbenzoic acid (BBA), 4-hexylbenzoic acid (HBA), and 4-octylbenzoic acid (OBA). These three small molecules share a benzoic acid moiety, but have different length of hydrophobic tails. The self-assembled interfacial layer of small molecules on the gate oxide surface leads to uniform deposition of TP crystal seeds and facilitates TP to grow along the tilted orientation of substrate, which results in a film of enhanced crystal orientation and areal coverage. OTFTs based on TP/small molecule blends demonstrate greatly improved average hole mobility and performance consistency, which correlates with the length of hydrophobic tail of the small-molecule additives. (C) 2013 Elsevier B.V. All rights reserved. C1 [He, Zhengran; Li, Dawen] Univ Alabama, Ctr Mat Informat Technol, Dept Elect & Comp Engn, Tuscaloosa, AL 35487 USA. [Chen, Jihua] Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Oak Ridge, TN 37831 USA. [Keum, Jong Kahk] Oak Ridge Natl Lab, Neutron Scattering Sci Div, Oak Ridge, TN 37831 USA. [Szulczewski, Greg] Univ Alabama, Dept Chem, Ctr Mat Informat Technol, Tuscaloosa, AL 35487 USA. RP Li, DW (reprint author), Univ Alabama, Ctr Mat Informat Technol, Dept Elect & Comp Engn, Tuscaloosa, AL 35487 USA. EM dawenl@eng.ua.edu RI Chen, Jihua/F-1417-2011; He, Zhengran/K-1869-2013; Keum, Jong/N-4412-2015; He, Zhengran/A-9898-2017 OI Chen, Jihua/0000-0001-6879-5936; He, Zhengran/0000-0002-6853-0265; Keum, Jong/0000-0002-5529-1373; FU National Science Foundation (NSF) [ECCS-1151140]; Division of Scientific User Facilities, Office of Basic Energy Sciences, U.S. Department of Energy FX This work was supported by National Science Foundation (NSF ECCS-1151140). A portion of this research was conducted at the Center for Nanophase Materials Sciences and Neutron Scattering Science Division, which are sponsored at Oak Ridge National Laboratory by the Division of Scientific User Facilities, Office of Basic Energy Sciences, U.S. Department of Energy. J.K. acknowledges sample preparation for X-ray reflectivity experiment from Dr. Ming Shao. NR 25 TC 11 Z9 11 U1 8 U2 63 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1566-1199 EI 1878-5530 J9 ORG ELECTRON JI Org. Electron. PD JAN PY 2014 VL 15 IS 1 BP 150 EP 155 DI 10.1016/j.orgel.2013.11.004 PG 6 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 277YS UT WOS:000328855800022 ER PT J AU AlQahtani, H Bryan, MT Hayward, TJ Hodges, MP Im, MY Fischer, P Grell, M Allwood, DA AF AlQahtani, Hadi Bryan, Matthew T. Hayward, Thomas J. Hodges, Matthew P. Im, M. -Y. Fischer, Peter Grell, Martin Allwood, Dan A. TI Planar organic spin valves using nanostructured Ni80Fe20 magnetic contacts SO ORGANIC ELECTRONICS LA English DT Article DE Organic spintronics; Organic spin valves; Planar spin valve; Spin transport; In-plane spin valve; Organic semiconductors ID SEMICONDUCTORS; INJECTION; PROPAGATION; INTERFACE AB Planar organic spin valves were fabricated by evaporating organic semiconductor PTCDI-C-13 onto pairs of patterned Ni80Fe20 magnetic nanowires separated by 120 nm. Control over the relative alignment of magnetisation in the nanowires was achieved by including a domain wall 'nucleation pad' at the end of one of the wires to ensure a large separation in magnetic switching fields. Switching behaviour was investigated by optical and X-ray magnetic imaging. Room temperature organic magnetoresistance of -0.35% was observed, which is large compared to that achieved in vertical spin valves with similar materials. We attribute the enhanced performance of the planar geometry to the deposition of the semiconductor on top of the metal, which improves the quality of metal-semiconductor interfaces compared to the metal-on-semiconductor interfaces in vertical spin valves. (C) 2013 Elsevier B.V. All rights reserved. C1 [AlQahtani, Hadi] King Saud Univ, Coll Sci, Dept Phys & Astron, Riyadh 11451, Saudi Arabia. [Bryan, Matthew T.; Hayward, Thomas J.; Hodges, Matthew P.; Allwood, Dan A.] Univ Sheffield, Dept Mat Sci & Engn, Sheffield S1 3JD, S Yorkshire, England. [Im, M. -Y.; Fischer, Peter] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. [Grell, Martin] Univ Sheffield, Dept Phys & Astron, Sheffield S3 7RH, S Yorkshire, England. RP AlQahtani, H (reprint author), King Saud Univ, Coll Sci, Dept Phys & Astron, Riyadh 11451, Saudi Arabia. EM hralqahtani@ksu.edu.sa RI Fischer, Peter/A-3020-2010; OI Fischer, Peter/0000-0002-9824-9343; Grell, Martin/0000-0003-0714-2039 FU King Saud University; EPSRC [EP/J002275/1]; Leading Foreign Research Institute Recruitment Program through the National Research Foundation of Korea (NRF) [2012K1A4A3053565]; Ministry of Education, Science and Technology (MEST); Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division, of the U.S. Department of Energy [DE-AC02-05-CH11231] FX HA would like to thank King Saud University for the financial support. MPH thanks EPSRC for a DTA studentship. TJH acknowledges the support of EPSRC through EP/J002275/1. P.F and M.-Y. Im acknowledge support from the Leading Foreign Research Institute Recruitment Program (Grant No. 2012K1A4A3053565) through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (MEST). The operation of the X-ray microscope work was supported by the Director, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division, of the U.S. Department of Energy under Contract No. DE-AC02-05-CH11231. NR 28 TC 1 Z9 1 U1 5 U2 35 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1566-1199 EI 1878-5530 J9 ORG ELECTRON JI Org. Electron. PD JAN PY 2014 VL 15 IS 1 BP 276 EP 280 DI 10.1016/j.orgel.2013.11.009 PG 5 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 277YS UT WOS:000328855800039 ER PT J AU Feakins, SJ Kirby, ME Cheetham, MI Ibarra, Y Zimmerman, SRH AF Feakins, Sarah J. Kirby, Matthew E. Cheetham, Michael I. Ibarra, Yadira Zimmerman, Susan R. H. TI Fluctuation in leaf wax D/H ratio from a southern California lake records significant variability in isotopes in precipitation during the late Holocene SO ORGANIC GEOCHEMISTRY LA English DT Article ID SANTA-BARBARA BASIN; DELTA-D VALUES; N-ALKANES RECORD; ORGANIC-MATTER; MASS-SPECTROMETRY; CLIMATE-CHANGE; MONICA BASIN; PLANTS; WATER; TERRESTRIAL AB The hydrogenisotopic composition of plant molecular markers in modern vegetation and marine sediments in southern California have been intensively studied. Here we report a late Holocene reconstruction from Zaca Lake in coastal southern California, together with modern hydrological and vegetation studies in the catchment. The small catchment and decadal sampling resolution throughout the 9 m, 3000 yr sedimentary record provided a high resolution terrigenous counterpart of nearby marine records from the Santa Barbara Basin. Today, delta D values of precipitation average -51.5 parts per thousand +/- 18 (1 sigma, n = 7). Modern plant leaf wax delta D values for the C-28 n-alkanoic acid averaged -141 parts per thousand +/- 11(1 sigma, n = 10) for Quercus agrifolia, with a calculated fractionation relative to precipitation (epsilon(wax/precip)) of -94 parts per thousand +/- 22(1 sigma, n = 10); in contrast, therewas negligible production of the C-28 acid by co-dominant Pinus coulteri. Downcore, the C-28 acid delta D values ranged between -101 parts per thousand and -177 parts per thousand (mean -150 parts per thousand +/- 8, 1 sigma, n = 490). Abundance distributions suggested that the sedimentary C-28 acid was dominated by Quercus, implying that paleoprecipitation varied between extremes of -8 parts per thousand and -92 parts per thousand (mean -63 parts per thousand +/- 14, compound 1 sigma, n = 490). The 3000 yr leaf wax D/H record from Zaca Lake revealed substantial temporal variability, greater than observed in a speleothem reconstruction of similar resolution. We suggest that the plant-based proxy may magnify the variability by sampling spring precipitation preferentially. Centennial-duration positive isotopic excursions were associated with more sub-tropical moisture sources and drier conditions including during the Medieval Climatic Anomaly, and negative excursions were associated with N Pacific sources and wetter conditions including during the Little Ice Age. (C) 2013 Elsevier Ltd. All rights reserved. C1 [Feakins, Sarah J.; Cheetham, Michael I.; Ibarra, Yadira] Univ So Calif, Dept Earth Sci, Los Angeles, CA 90089 USA. [Kirby, Matthew E.] Calif State Univ Fullerton, Dept Geol Sci, Fullerton, CA 92834 USA. [Zimmerman, Susan R. H.] Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. RP Feakins, SJ (reprint author), Univ So Calif, Dept Earth Sci, 3651 Trousdale Pkwy, Los Angeles, CA 90089 USA. EM feakins@usc.edu RI Feakins, Sarah/K-4149-2012; Zimmerman, Susan/A-3351-2013 OI Feakins, Sarah/0000-0003-3434-2423; FU U.S National Science Foundation [EAR-1002656]; University of Southern California; Lawrence Livermore National Laboratory [LDRD-09ERI003] FX The research was supported by U.S National Science Foundation Grant EAR-1002656 to S. F. and M. K.; coring was supported by startup funding from the University of Southern California to S. F.; radiocarbon dating was supported by Lawrence Livermore National Laboratory grant LDRD-09ERI003 to S.Z. The manuscript was improved with the comments of B. Tipple and an anonymous reviewer. A. Mybro and the National Lacustrine Core Facility (Lac-Core) supported the coring operation. Thanks go to M. Rincon, who supported analytical work at USC, L. Reidy who provided invasive pollen counts, R. Byrne who commented on invasive species, D. Hammond who provided Cs counts, W. Berelson and F. Corsetti for general discussion of the Zaca Lake project and K. Johnson for discussion of the Crystal Cave record. Many students participated in the field and laboratory including: Z. Zhang, M. McDonald, H. Liddy, L. Petrie, S. Oh, V. Nguyen, C. Hua (USC), and M. Padilla, J. Fantozzi, C. Hiner and B. Davidson (CSUF). We thank the Zaca Lake Foundation for access to the lake. NR 55 TC 13 Z9 13 U1 1 U2 25 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0146-6380 J9 ORG GEOCHEM JI Org. Geochem. PD JAN PY 2014 VL 66 BP 48 EP 59 DI 10.1016/j.orggeochem.2013.10.015 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 281VQ UT WOS:000329129500005 ER PT J AU Jiang, L Sun, ST Heine, N Liu, JW Yacovitch, TI Wende, T Liu, ZF Neumark, DM Asmis, KR AF Jiang, Ling Sun, Shou-Tian Heine, Nadja Liu, Jian-Wen Yacovitch, Tara I. Wende, Torsten Liu, Zhi-Feng Neumark, Daniel M. Asmis, Knut R. TI Large amplitude motion in cold monohydrated dihydrogen phosphate anions H2PO4-(H2O): infrared photodissociation spectroscopy combined with ab initio molecular dynamics simulations SO PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article ID PROTONATED WATER DIMER; GAS-PHASE; AQUEOUS-SOLUTION; CLUSTERS; HYDRATION; IONS; SPECTRA; METAPHOSPHATE; COMPLEXES; PO3 AB The vibrational spectroscopy of monohydrated dihydrogen phosphate anions, H2PO4-(H2O), is studied in the O-H stretching (2700-3900 cm(-1)) and the fingerprint regions (600-1800 cm(-1)). Assignment of the experimental infrared multiple photon photodissociation spectra based on the predicted harmonic spectra of energetically low-lying 0 K structures is not conclusive. Ab initio molecular dynamics simulations reveal that the water molecule undergoes large amplitude motion, even at low internal temperatures, and that the dipole time correlation function qualitatively captures the anharmonic effects of the low-barrier isomerization reaction on the infrared intensities. C1 [Jiang, Ling; Heine, Nadja; Wende, Torsten; Asmis, Knut R.] Max Planck Gesell, Fritz Haber Inst, D-14195 Berlin, Germany. [Sun, Shou-Tian; Liu, Zhi-Feng] Chinese Univ Hong Kong, Dept Chem, Hong Kong, Hong Kong, Peoples R China. [Sun, Shou-Tian; Liu, Zhi-Feng] Chinese Univ Hong Kong, Ctr Sci Modeling & Computat, Hong Kong, Hong Kong, Peoples R China. [Liu, Jian-Wen] Natl Supercomp Ctr Shenzhen, Shenzhen, Peoples R China. [Yacovitch, Tara I.; Neumark, Daniel M.] Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. [Neumark, Daniel M.] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. [Asmis, Knut R.] Univ Leipzig, Wilhelm Ostwald Inst Phys & Theoret Chem, D-04103 Leipzig, Germany. RP Liu, ZF (reprint author), Chinese Univ Hong Kong, Dept Chem, Hong Kong, Hong Kong, Peoples R China. EM zfliu@cuhk.edu.hk; dneumark@berkeley.edu; asmis@fhi-berlin.mpg.de RI Asmis, Knut/N-5408-2014; Neumark, Daniel/B-9551-2009; Heine, Nadja/G-8839-2013 OI Asmis, Knut/0000-0001-6297-5856; Neumark, Daniel/0000-0002-3762-9473; FU Alexander-von-Humboldt Foundation; Chinese University of Hong Kong [2060427]; Shenzhen Strategic Emerging Industry Special Fund Program of China [GGJS 20120619101655715]; Air Force Office of Scientific Research [FA9550-12-1-0160] FX We would like to thank the Stichting voor Fundamenteel Onderzoek der Materie (FOM) for beam time at FELIX and the FELIX-staff for excellent support and assistance. L. Jiang thanks the Alexander-von-Humboldt Foundation for a post-doctoral scholarship. We are grateful for the generous allocation of computer time at the National Supercomputing Center in Shenzhen and on the clusters of PCs at the Center for Scientific Modeling and Computation of the Chinese University of Hong Kong. The project is supported by a Direct Grant (2060427) from The Chinese University of Hong Kong. J.-W. Liu thanks Shenzhen Strategic Emerging Industry Special Fund Program of China (Grant No. GGJS 20120619101655715) for financial support. T. I. Yacovitch and D. M. Neumark were supported by the Air Force Office of Scientific Research under Grant No. FA9550-12-1-0160. NR 40 TC 15 Z9 15 U1 7 U2 54 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1463-9076 EI 1463-9084 J9 PHYS CHEM CHEM PHYS JI Phys. Chem. Chem. Phys. PY 2014 VL 16 IS 4 BP 1314 EP 1318 DI 10.1039/c3cp54250e PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 278IZ UT WOS:000328884900002 PM 24306270 ER PT J AU Alarcon-Llado, E Chen, L Hettick, M Mashouf, N Lin, YJ Javey, A Ager, JW AF Alarcon-Llado, Esther Chen, Le Hettick, Mark Mashouf, Neeka Lin, Yongjing Javey, Ali Ager, Joel W. TI BiVO4 thin film photoanodes grown by chemical vapor deposition SO PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article ID BISMUTH VANADATE; WATER OXIDATION; EFFICIENT; PERFORMANCE; PHOTOOXIDATION; CATALYST AB BiVO4 thin film photoanodes were grown by vapor transport chemical deposition on FTO/glass substrates. By controlling the flow rate, the temperatures of the Bi and V sources (Bi metal and V2O5 powder, respectively), and the temperature of the deposition zone in a two-zone furnace, single-phase monoclinic BiVO4 thin films can be obtained. The CVD-grown films produce global AM1.5 photocurrent densities up to 1 mA cm(-2) in aqueous conditions in the presence of a sacrificial reagent. Front illuminated photocatalytic performance can be improved by inserting either a SnO2 hole blocking layer and/or a thin, extrinsically Mo doped BiVO4 layer between the FTO and the CVD-grown layer. The incident photon to current efficiency (IPCE), measured under front illumination, for BiVO4 grown directly on FTO/glass is about 10% for wavelengths below 450 nm at a bias of + 0.6 V vs. Ag/AgCl. For BiVO4 grown on a 40 nm SnO2/20 nm Mo-doped BiVO4 back contact, the IPCE is increased to over 40% at wavelengths below 420 nm. C1 [Alarcon-Llado, Esther; Chen, Le; Hettick, Mark; Mashouf, Neeka; Lin, Yongjing; Javey, Ali; Ager, Joel W.] Joint Ctr Artificial Photosynthesis, Berkeley, CA USA. [Alarcon-Llado, Esther] Ecole Polytech Fed Lausanne, LMSC SMX, Lausanne, Switzerland. [Alarcon-Llado, Esther; Chen, Le; Hettick, Mark; Lin, Yongjing; Javey, Ali; Ager, Joel W.] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. [Hettick, Mark; Lin, Yongjing; Javey, Ali] Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA. RP Ager, JW (reprint author), Joint Ctr Artificial Photosynthesis, 2929 7th St, Berkeley, CA USA. EM esther.alarconllado@epfl.ch; lechen@lbl.gov; JWAger@lbl.gov RI Alarcon Llado, Esther/I-5583-2015; Javey, Ali/B-4818-2013; OI Alarcon Llado, Esther/0000-0001-7317-9863; Ager, Joel/0000-0001-9334-9751 FU Office of Science of the U. S. Department of Energy [DE-SC0004993]; Marie Curie Actions Program FX This material is based upon work performed by the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, supported through the Office of Science of the U.S. Department of Energy under Award Number DE-SC0004993. EAL acknowledges fellowship support from Marie Curie Actions Program. NR 21 TC 22 Z9 22 U1 5 U2 77 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1463-9076 EI 1463-9084 J9 PHYS CHEM CHEM PHYS JI Phys. Chem. Chem. Phys. PY 2014 VL 16 IS 4 BP 1651 EP 1657 DI 10.1039/c3cp53904k PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 278IZ UT WOS:000328884900041 PM 24322301 ER PT J AU Ahn, JW Scotti, F Kim, K Canik, JM Lore, JD Maingi, R McLean, AG Bell, RE Diallo, A Gerhardt, SP Gray, TK Kaye, SM LeBlanc, BP Soukhanovskii, VA Tritz, K AF Ahn, J-W Scotti, F. Kim, K. Canik, J. M. Lore, J. D. Maingi, R. McLean, A. G. Bell, R. E. Diallo, A. Gerhardt, S. P. Gray, T. K. Kaye, S. M. LeBlanc, B. P. Soukhanovskii, V. A. Tritz, K. TI Characterization of divertor footprints and the pedestal plasmas in the presence of applied n=3 fields for the attached and detached conditions in NSTX SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article DE 3D fields; non-axisymmetric effect; detachment; divertor profile and footprints; pedestal profiles ID SPHERICAL TORUS EXPERIMENT; SYSTEM AB Recent progress in the study of 3D field effects on the divertor and pedestal plasmas is reported with the use of a new set of diagnostics. A wide angle visible camera provides 2D data of lower divertor surface covering almost the full range of radius (r) and toroidal angle (Phi), a significant advantage over the conventional 1D radial profile in examining non-axisymmetric effects of 3D fields on the divertor footprints. The spatial distribution of connection lengths (L-c) calculated by vacuum field line tracing in the presence of 3D fields (n = 3) agrees with the footprint pattern observed in the 2D wide angle camera images. The full (r, Phi) image data with high temporal resolution revealed that the spatial structure of modified divertor footprints is maintained even during the edge-localized modes (ELMs) triggered by applied n = 3 fields, when the ELM size is sufficiently small, i.e. the ELMs are 'phase locked' to the imposed perturbation field structure. This phase-lock is lost during the ELM rise time for ELMs with large energy loss, e. g. Delta W-ELM/W-MHD > 4-5%. Divertor gas puff was used to create detached divertor condition and the effect of 3D fields on the detachment was investigated. The divertor remains partially detached with the 3D field application when a sufficient amount of gas is injected into the divertor region, which is accompanied by a noticeable drop of pedestal electron temperature (T-e). However, with a lower gas puff, the divertor plasma re-attaches, when 3D fields were applied to the detached plasma, and the pedestal T-e rises back up. There observed no other change in the pedestal profile associated with the re-attachment, indicating that this is likely to be dominated by a change in the electron thermal transport processes. A TRANSP analysis shows that the drop of pedestal electron heat diffusivity (chi(e)) is responsible for this change but the source of this reduction is yet unclear. C1 [Ahn, J-W; Canik, J. M.; Lore, J. D.; Maingi, R.; Gray, T. K.] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. [Scotti, F.; Kim, K.; Bell, R. E.; Diallo, A.; Gerhardt, S. P.; Kaye, S. M.; LeBlanc, B. P.] Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. [McLean, A. G.; Soukhanovskii, V. A.] Lawrence Livermore Natl Lab, Livermore, CA USA. [Tritz, K.] Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. RP Ahn, JW (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM jahn@pppl.gov OI Canik, John/0000-0001-6934-6681; Lore, Jeremy/0000-0002-9192-465X FU US Department of Energy [DE-AC05-00OR22725, DE-AC52-07NA27344, DE-AC02-09CH11466] FX This work was supported by the US Department of Energy, contract numbers DE-AC05-00OR22725, DE-AC52-07NA27344 and DE-AC02-09CH11466. The authors acknowledge the international collaboration with the IPP-Garching and the technical help from Dr A Herrmann for the use of THEODOR heat conduction code. NR 34 TC 6 Z9 6 U1 1 U2 14 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0741-3335 EI 1361-6587 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD JAN PY 2014 VL 56 IS 1 AR 015005 DI 10.1088/0741-3335/56/1/015005 PG 10 WC Physics, Fluids & Plasmas SC Physics GA 278QA UT WOS:000328903600005 ER PT J AU Van Zeeland, MA Ferraro, NM Heidbrink, WW Kramer, GJ Pace, DC Chen, X Evans, TE Fisher, RK Garcia-Munoz, M Hanson, JM Lanctot, MJ Lao, LL Moyer, RA Nazikian, R Orlov, DM AF Van Zeeland, M. A. Ferraro, N. M. Heidbrink, W. W. Kramer, G. J. Pace, D. C. Chen, X. Evans, T. E. Fisher, R. K. Garcia-Munoz, M. Hanson, J. M. Lanctot, M. J. Lao, L. L. Moyer, R. A. Nazikian, R. Orlov, D. M. TI Modulation of prompt fast-ion loss by applied n=2 fields in the DIII-D tokamak SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article DE tokamaks; spherical tokamaks; particle measurements; fusion products effects (e. g. alpha-particles, etc); fast particle effects; particle orbit and trajectory; plasma heating by particle beams AB Energy and pitch angle resolved measurements of escaping neutral beam ions (E approximate to 80 keV) have been made during DIII-D L-mode discharges with applied, slowly rotating, n = 2 magnetic perturbations. Data from separate scintillator detectors (FILDs) near and well below the plasma midplane show fast-ion losses correlated with the internal coil (I-coil) fields. The dominant fast-ion loss signals are observed to decay within one poloidal transit time after beam turn-off indicating they are primarily prompt loss orbits. Also, during application of the rotating I-coil fields, outboard midplane edge density and bremsstrahlung emission profiles exhibit a radial displacement of up to delta R approximate to 1 cm. Beam deposition and full orbit modeling of these losses using M3D-C1 calculations of the perturbed kinetic profiles and fields reproduce many features of the measured losses. In particular, the predicted phase of the modulated loss signal with respect to the I-coil currents is in close agreement with FILD measurements as is the relative amplitudes of the modulated losses for the co and counter-current beam used in the experiment. These simulations show modifications to the beam ion birth profile and subsequent prompt loss due to changes in the edge density; however, the dominant factor causing modulation of the losses to the fast-ion loss detectors is the perturbed magnetic field (delta B/B approximate to 10(-3) in the plasma). Calculations indicate total prompt loss to the DIII-D wall can increase with application of the n = 2 perturbation by up to 7% for co-current injected beams and 3% for counter-current injected beams depending on phase of the perturbation relative to the injected beam. C1 [Van Zeeland, M. A.; Ferraro, N. M.; Pace, D. C.; Evans, T. E.; Fisher, R. K.; Lanctot, M. J.; Lao, L. L.] Gen Atom Co, San Diego, CA 92186 USA. [Heidbrink, W. W.; Chen, X.] Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA. [Kramer, G. J.; Nazikian, R.] Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. [Garcia-Munoz, M.] EURATOM, Max Planck Inst Plasmaphys, Garching, Germany. [Hanson, J. M.] Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10027 USA. [Moyer, R. A.; Orlov, D. M.] Univ Calif San Diego, Energy Res Ctr, La Jolla, CA 92093 USA. [Moyer, R. A.; Orlov, D. M.] Univ Calif San Diego, Dept Mech & Aerosp Engn, La Jolla, CA 92093 USA. RP Van Zeeland, MA (reprint author), Gen Atom Co, POB 85608, San Diego, CA 92186 USA. RI garcia-munoz, manuel/C-6825-2008; Orlov, Dmitriy/D-2406-2016; Lanctot, Matthew J/O-4979-2016 OI garcia-munoz, manuel/0000-0002-3241-502X; Orlov, Dmitriy/0000-0002-2230-457X; Lanctot, Matthew J/0000-0002-7396-3372 FU US Department of Energy [DE-FC02-04ER54698, SC-G903402, DE-AC02-09CH11466, DE-FG02-04ER54761, DE-FG02-05ER54808] FX This work was supported in part by the US Department of Energy under DE-FC02-04ER54698, SC-G903402, DE-AC02-09CH11466, DE-FG02-04ER54761 and DE-FG02-05ER54808. Effective beam stopping cross-sections used in the beam ion birth profile calculations were obtained from the Atomic Data and Analysis Structure(ADAS) compilation. The originating developer of ADAS is the JET Joint Undertaking. NR 21 TC 13 Z9 13 U1 0 U2 11 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0741-3335 EI 1361-6587 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD JAN PY 2014 VL 56 IS 1 AR 015009 DI 10.1088/0741-3335/56/1/015009 PG 10 WC Physics, Fluids & Plasmas SC Physics GA 278QA UT WOS:000328903600009 ER PT J AU Shenai, K Dudley, M Davis, RF AF Shenai, Krishna Dudley, Michael Davis, Robert F. TI Rugged Electrical Power Switching in Semiconductors: A Systems Approach SO PROCEEDINGS OF THE IEEE LA English DT Article DE Field reliability; gallium nitride (GaN); manufacturing; power electronics; power metal-oxide-semiconductor field-effect transistors (MOSFETs); power supplies; silicon; silicon carbide (SiC); single-event burnout (SEB) stress test; wide bandgap (WBG) semiconductor power devices ID CARBIDE SINGLE-CRYSTALS; P-N-JUNCTION; SILICON-CARBIDE; MATERIAL DEFECTS; GROWTH; DIODES; RELIABILITY; BULK; DISLOCATIONS; BREAKDOWN AB Current status of wide bandgap (WBG) semiconductor material technology is evaluated for developing high-performance and reliable power electronics switching converters. The study takes into account field reliability of silicon power metal-oxide-semiconductor field-effect transistors (MOSFETs) in compact computer/telecom power supplies where residual material defects present in the silicon space-charge region were found to generate local microplasma that eventually caused power MOSFETs to fail under long-term repetitive field-switching conditions. It is shown that silicon power MOSFETs with increased low-level leakage currents are more prone to field failures in high-density power supplies. A new single-event burnout (SEB) stress testing methodology is proposed; the SEB stress test results are shown to correlate well with silicon power MOSFET failures in power supply circuits. Based on these results and the current state of the art of silicon carbide (SiC) and gallium nitride (GaN) power devices, a "reliability-driven'' manufacturing approach is recommended for rapid commercialization and market penetration of WBG semiconductor power devices. C1 [Shenai, Krishna] Argonne Natl Lab, Div Energy Syst, Argonne, IL 60439 USA. [Dudley, Michael] SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. [Davis, Robert F.] Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. RP Shenai, K (reprint author), Argonne Natl Lab, Div Energy Syst, 9700 S Cass Ave, Argonne, IL 60439 USA. EM kshenai@anl.gov; Michael.Dudley@sunysb.edu; rfd@andrew.cmu.edu RI Davis, Robert/A-9376-2011 OI Davis, Robert/0000-0002-4437-0885 FU Argonne, a U.S. Department of Energy Office of Science laboratory [AC02-06CH11357] FX This work was created by University of Chicago/Argonne, LLC, Operator of Argonne National Laboratory ("Argonne''). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract DE-AC02-06CH11357. The U.S. Government retains for itself, and others acting on its behalf, a paid-up 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. NR 84 TC 7 Z9 7 U1 2 U2 29 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9219 EI 1558-2256 J9 P IEEE JI Proc. IEEE PD JAN PY 2014 VL 102 IS 1 BP 35 EP 52 DI 10.1109/JPROC.2013.2278616 PG 18 WC Engineering, Electrical & Electronic SC Engineering GA 279NF UT WOS:000328966000006 ER PT J AU Nemeth, K Srajer, G AF Nemeth, Karoly Srajer, George TI CO2/oxalate cathodes as safe and efficient alternatives in high energy density metal-air type rechargeable batteries SO RSC ADVANCES LA English DT Article ID NONAQUEOUS LI-O-2 BATTERIES; MELTING-POINT DEPRESSION; DEEP EUTECTIC SOLVENTS; CARBON-DIOXIDE; IONIC LIQUIDS; PROPYLENE CARBONATE; SOLID-STATE; AMBIENT AIR; LITHIUM; CO2 AB We present theoretical analysis on why and how rechargeable metal-air type batteries can be made significantly safer and more practical by utilizing CO2/oxalate conversions instead of O-2/peroxide or O-2/hydroxide ones, in the positive electrode. Metal-air batteries, such as the Li-air one, may have very large energy densities, comparable to that of gasoline, theoretically allowing for long range all-electric vehicles. There are, however, still significant challenges, especially related to the safety of their underlying chemistries, the robustness of their recharging and the need of supplying high purity O-2 from air to the battery. We point out that the CO2/oxalate reversible electrochemical conversion is a viable alternative of the O-2-based ones, allowing for similarly high energy density and almost identical voltage, while being much safer through the elimination of aggressive oxidant peroxides and the use of thermally stable, non-oxidative and environmentally benign oxalates instead. C1 [Nemeth, Karoly; Srajer, George] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. [Nemeth, Karoly] IIT, Dept Phys, Chicago, IL 60616 USA. RP Nemeth, K (reprint author), Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. EM nemeth@ANL.Gov RI Nemeth, Karoly/L-7806-2014 OI Nemeth, Karoly/0000-0001-8366-1397 FU U.S. DOE Office of Science [DE-AC02-06CH11357] FX K. N. gratefully acknowledges helpful discussions with Drs M. Balasubramanian, G. Crabtree, N. Markovic, L. Trahey, and M. van Veenendaal at Argonne National Laboratory and A. K. Unni, C. U. Segre and L. Shaw at IIT. This research was supported by the U.S. DOE Office of Science, under contract no. DE-AC02-06CH11357. NR 44 TC 3 Z9 3 U1 1 U2 42 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 2046-2069 J9 RSC ADV JI RSC Adv. PY 2014 VL 4 IS 4 BP 1879 EP 1885 DI 10.1039/c3ra45528a PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA 280MF UT WOS:000329033700043 ER PT J AU Datskos, P Chen, J Sharma, J AF Datskos, P. Chen, J. Sharma, J. TI Addressable morphology control of silica structures by manipulating the reagent addition time SO RSC ADVANCES LA English DT Article ID REVERSE MICELLES; TRITON X-100; SHAPE; PARTICLES; NANOSTRUCTURES; CYCLOHEXANE; NANORODS; COMPLEX; WATER AB The current synthesis strategies focus on addition of all reagents together. Herein, we demonstrate the effect of reagent addition time on the finalmorphology of colloidal silica structures without changing the actual reaction conditions, and utilize this effect to synthesize silica rods with addressable diameter control. C1 [Datskos, P.; Sharma, J.] Oak Ridge Natl Lab, Nanosyst Separat & Mat Res Grp, Energy & Transportat Sci Div, Oak Ridge, TN 37831 USA. [Chen, J.] Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Oak Ridge, TN 37831 USA. RP Sharma, J (reprint author), Oak Ridge Natl Lab, Nanosyst Separat & Mat Res Grp, Energy & Transportat Sci Div, 1 Bethel Valley Rd, Oak Ridge, TN 37831 USA. EM sharmajk@ornl.gov RI Chen, Jihua/F-1417-2011 OI Chen, Jihua/0000-0001-6879-5936 FU U.S. Department of Energy [DE-AC05-00OR22725]; Laboratory Director's Research and Development Program of the Oak Ridge National Laboratory; Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy FX J. Sharma is a Eugene P. Wigner Fellow at the Oak Ridge National Laboratory managed by UT-Battelle, LLC, for the U.S. Department of Energy under Contract DE-AC05-00OR22725. The work was supported by the Laboratory Director's Research and Development Program of the Oak Ridge National Laboratory. A portion of this research was conducted at the Center for Nanophase Materials Sciences, which is sponsored at Oak Ridge National Laboratory by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy. NR 20 TC 7 Z9 7 U1 3 U2 33 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 2046-2069 J9 RSC ADV JI RSC Adv. PY 2014 VL 4 IS 5 BP 2291 EP 2294 DI 10.1039/c3ra46464d PG 4 WC Chemistry, Multidisciplinary SC Chemistry GA 280MV UT WOS:000329035400027 ER PT J AU Cormier, RA Gregg, BA AF Cormier, Russell A. Gregg, Brian A. TI Bis-dithiano perylene diimide: synthesis and characterization of a novel ring system SO RSC ADVANCES LA English DT Article ID BISIMIDES; CRYSTAL; SEMICONDUCTORS; TRANSISTORS; DYES AB We report the transformation of a 1,7-dibromo perylene diimide into a 1,6,7,12-tetrasulfur-substituted expanded ring system at room temperature in high yield. The resulting bis-dithiano perylene diimide completes the series of five sulfur-annulated perylene ring systems, the first four of which are known. We describe the synthesis and characterization of the title compound, PS4, and other sulfur-annulated species formed under slightly different conditions. Optical and electrochemical data of both solution and solid films of this compound are reported. At slow scan rate a film of PS4 self-organizes, rearranging its structure to accommodate its changing oxidation state. PS4 is a lightly n-doped semiconductor in inert atmosphere (conductivity, sigma = 4.6 x 10(-6) S cm(-1)) that becomes compensated in air (sigma = 2.4 x 10(-9) S cm(-1)) to an unusual, almost intrinsic (undoped) state. The properties of PS4 suggest applications in organic electronics. C1 [Cormier, Russell A.; Gregg, Brian A.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Gregg, BA (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM brian.gregg@nrel.gov FU U.S. Department of Energy, Office of Science, Basic Energy Science, Division of Chemical Sciences, Geosciences and Biosciences [DE-AC36-08GO28308] FX This work was funded by the U.S. Department of Energy, Office of Science, Basic Energy Science, Division of Chemical Sciences, Geosciences and Biosciences, under Contract no. DE-AC36-08GO28308 to NREL. NR 19 TC 2 Z9 2 U1 2 U2 18 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 2046-2069 J9 RSC ADV JI RSC Adv. PY 2014 VL 4 IS 5 BP 2368 EP 2373 DI 10.1039/c3ra44872j PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA 280MV UT WOS:000329035400039 ER PT J AU Campo, EM Poplawsky, J Melendez, A Robles-Garcia, JL Ramos, I Yates, D Fischer, JE Santiago-Aviles, JJ AF Campo, Eva M. Poplawsky, Jonathan Melendez, Anamaris Robles-Garcia, Joshua L. Ramos, Idalia Yates, Douglas Fischer, John E. Santiago-Aviles, Jorge J. TI Disordered grain growth in polycrystalline GaN obtained by the polymer-derived-ceramic route SO RSC ADVANCES LA English DT Article ID LIGHT-EMITTING-DIODES; GALLIUM NITRATE HYDRATE; THERMAL-DECOMPOSITION; THIN-FILMS; FIBERS; ELECTROSPUN; NANOFIBERS AB Polycrystalline GaN fibers have been produced by the polymer-derived-ceramic (PDC) technique. The wurtzite-polymorphic fibers appear to emerge from complex nucleation and grain growth mechanisms, being mostly unconstrained during initial polymer to ceramic conversion. The importance of carrier polymer architecture and alignment is highlighted towards controlled microstructure. C1 [Campo, Eva M.] Bangor Univ, Dept Elect Engn, Bangor LL57 1UT, Gwynedd, Wales. [Poplawsky, Jonathan] Oak Ridge Natl Lab, Mat Sci & Technol Div, Oak Ridge, TN 37831 USA. [Melendez, Anamaris; Robles-Garcia, Joshua L.; Ramos, Idalia] Univ Puerto Rico Humacao, Dept Phys & Elect, Humacao, PR 00791 USA. [Yates, Douglas; Fischer, John E.; Santiago-Aviles, Jorge J.] Univ Penn, Lab Res Struct Matter, Philadelphia, PA 19104 USA. RP Campo, EM (reprint author), Bangor Univ, Dept Elect Engn, Bangor LL57 1UT, Gwynedd, Wales. EM e.campo@bangor.ac.uk RI Poplawsky, Jonathan/Q-2456-2015 OI Poplawsky, Jonathan/0000-0002-4272-7043 FU PENN-UPR [NSF-DMR-0934195] FX This work was supported by the PENN-UPR Partnership for Research and Education in Materials (Grant NSF-DMR-0934195). NR 43 TC 3 Z9 3 U1 1 U2 9 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 2046-2069 J9 RSC ADV JI RSC Adv. PY 2014 VL 4 IS 6 BP 2634 EP 2639 DI 10.1039/c3ra44899a PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA 280NK UT WOS:000329037100012 ER PT J AU Allen, AJ Ilavsky, J Jemian, PR Braun, A AF Allen, Andrew J. Ilavsky, Jan Jemian, Pete R. Braun, Artur TI Evolution of electrochemical interfaces in solid oxide fuel cells (SOFC): a Ni and Zr resonant anomalous ultra-small-angle X-ray scattering study with elemental and spatial resolution across the cell assembly SO RSC ADVANCES LA English DT Article ID TOLERANT ANODE MATERIALS; OPERATING TEMPERATURE; YSZ CERMET; SULFUR; MICROSTRUCTURE; DEGRADATION; ENERGY; RECONSTRUCTION; SPECTROSCOPY; CATHODE AB Electrochemical interfaces are key to the direct conversion of fuels to electrical energy and lend energy converters like solid oxide fuel cells (SOFC) their functionality. Over extended operation at high temperatures, the microstructure of the underlying component materials in the cathodes, anodes and electrolytes evolve to an extent that these interfaces become affected and ultimately impaired, giving rise to performance degradation. We present anomalous ultra-small-angle X-ray scattering (anomalous USAXS) measurements to quantify the component phase interfacial surface areas as a function of position within the electrodes and electrolyte of a SOFC assembly. Using USAXS at a 3rd generation X-ray synchrotron facility, the primary microstructural parameters obtained are the mean feature size, size distribution and surface area, determined over a contiguous length scale from nanometers to micrometers in a single measurement at a given position. Here, a spatial resolution of <20 mu m has been achieved perpendicular to the SOFC electrode and electrolyte layers. Anomalous USAXS measurements at X-ray energies just below the Ni and Zr K-absorption edges have enabled the electrochemically-active solid components and their associated void morphologies to be distinguished from each other close to the electrode/electrolyte interfaces. The anomalous variation of the X-ray scattering contrast with X-ray energy has been exploited to distinguish Ni-rich or Zr-rich component microstructures from adjacent phases, and to determine the interfacial surface areas both between specific solid phases and between each phase and the void network. Such information provides improved insights for relating the morphology of the SOFC triple phase boundary (TPB, where the reactant gas, electron-conducting and ion-conducting phases coincide) to the various component interfaces in the adjacent microstructure. We demonstrate how such measurements determine the electrochemically-active interface response to SOFC service life, especially in the anode with and without sulfur present in the fuel. Our approach can be generalized to address degradation issues at a quantitative level in other electrochemical systems such as batteries and photo-electrochemical cells. C1 [Allen, Andrew J.] NIST, US Dept Commerce, Mat Measurement Lab, Gaithersburg, MD 20899 USA. [Ilavsky, Jan] Argonne Natl Lab, XRay Sci Div, Adv Photon Source, Argonne, IL 60439 USA. [Jemian, Pete R.] Argonne Natl Lab, APS Engn Support Div, Adv Photon Source, Argonne, IL 60439 USA. [Braun, Artur] Swiss Fed Labs Mat Sci & Technol, Empa, Lab High Performance Ceram, CH-8600 Dubendorf, Switzerland. RP Allen, AJ (reprint author), NIST, US Dept Commerce, Mat Measurement Lab, Bldg 223,Rm B204,100 Bur Dr,Mailstop 8520, Gaithersburg, MD 20899 USA. EM andrew.allen@nist.gov; ilavsky@aps.anl.gov; jemian@anl.gov; artur.braun@alumni.ethz.ch RI USAXS, APS/D-4198-2013; Ilavsky, Jan/D-4521-2013; BRAUN, Artur/A-1154-2009 OI Ilavsky, Jan/0000-0003-1982-8900; BRAUN, Artur/0000-0002-6992-7774 FU European Union [SES6-CT-2003-502612, MIRG-CT-2006-042095, 256885]; Swiss Competence Center for Energy Mobility [CCEM-705]; U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences [DE-AC02-06CH11357] FX We thank J. Sfeir (Hexis AG) for discussions and providing SOFC test specimens; S. Claggett (NIST Metallurgy Division) for ceramographic USAXS sample preparation; R. Bachtold (Empa) for the optical micrographs; and P. Holtappels and T. Graule (Empa) for supporting this project. A. B. is grateful for financial support from the European Union (Real-SOFC project no. SES6-CT-2003-502612; Marie Curie Actions no. MIRG-CT-2006-042095, SOFC-LIFE project no. 256885), and from the Swiss Competence Center for Energy & Mobility, project no. CCEM-705. Use of the Advanced Photon Source was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract no. DE-AC02-06CH11357. NR 48 TC 0 Z9 0 U1 1 U2 18 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 2046-2069 J9 RSC ADV JI RSC Adv. PY 2014 VL 4 IS 9 BP 4676 EP 4690 DI 10.1039/c3ra46886k PG 15 WC Chemistry, Multidisciplinary SC Chemistry GA 279JQ UT WOS:000328956700057 ER PT J AU Chatterjee, S Clingenpeel, A McKenna, A Rios, O Johs, A AF Chatterjee, Sabornie Clingenpeel, Amy McKenna, Amy Rios, Orlando Johs, Alexander TI Synthesis and characterization of lignin-based carbon materials with tunable microstructure SO RSC ADVANCES LA English DT Article ID RESOLUTION MASS-SPECTROMETRY; LI-ION BATTERIES; LITHIUM INSERTION; OXIDATIVE STABILIZATION; ORGANOSOLV LIGNIN; MESOPHASE PITCH; KRAFT LIGNIN; ANODES; FIBER; HYDRODEOXYGENATION AB Lignin-based carbons can be used as a low-cost alternative to graphite and petroleum-based carbons enabling the production of sustainable, functional carbon materials for various applications. The microstructure development of these carbons can be controlled through chemical modification of the lignin precursor and choice of carbonization parameters. In this work, microstructured carbon materials are synthesized from lignin using a combination of chemical modification and carbon fiber processing techniques. Lignin is modified by incorporating different ester groups which results in a precursor highly compatible with melt processing using the fiber extrusion technique and conversion into microstructured carbons by oxidative stabilization and subsequent carbonization. Furthermore, the impact of esterifications on precursor chemistry and carbonizations is investigated. A nuclear magnetic resonance study of modified lignins shows characteristic spectral changes as a result of esterifications. Ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry shows the modification process does not affect the polymeric character of the lignin backbone. Esterifications result in moderate shifts in O : C and H : C ratios. Thermogravimetric analysis of lignins reveals distinct differences in mass loss trends during oxidations and carbonizations. C1 [Chatterjee, Sabornie; Rios, Orlando; Johs, Alexander] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. [Clingenpeel, Amy] Florida State Univ, Dept Chem & Biochem, Tallahassee, FL 32306 USA. [McKenna, Amy] Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. RP Chatterjee, S (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM saborniec@gmail.com; johsa@ornl.gov RI Johs, Alexander/F-1229-2011; Rios, Orlando/E-6856-2017 OI Johs, Alexander/0000-0003-0098-2254; Rios, Orlando/0000-0002-1814-7815 FU Laboratory Directed Research and Development (LDRD) Program of Oak Ridge National Laboratory (ORNL); U.S. Department of Energy [DE-AC05-00OR22725]; National Science Foundation (NSF) Division of Materials [DMR-1157490]; Florida State University; Future Fuels Institute; BP/The Gulf of Mexico Research Initiative; State of Florida FX This research was sponsored by the Laboratory Directed Research and Development (LDRD) Program of Oak Ridge National Laboratory (ORNL), which is managed by UT-Battelle, LLC, for the U.S. Department of Energy under Contract no. DE-AC05-00OR22725. Work performed at the National High Magnetic Field Laboratory was supported by the National Science Foundation (NSF) Division of Materials Research through DMR-1157490, Florida State University, the Future Fuels Institute, BP/The Gulf of Mexico Research Initiative to the Deep-C Consortium, and the State of Florida. A few NMR spectra were collected with the help of Dr J. J. Bozell, Center for Renewable Carbon, The University of Tennessee, Knoxville, TN. All other NMR spectra were collected at the Center for Nano-phase Materials Sciences (CNMS), ORNL through a user proposal (CNMS2012-R81). We acknowledge the help of Dr Peter Bonnesen for collecting these spectra at CNMS. NR 54 TC 17 Z9 17 U1 9 U2 86 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 2046-2069 J9 RSC ADV JI RSC Adv. PY 2014 VL 4 IS 9 BP 4743 EP 4753 DI 10.1039/c3ra46928j PG 11 WC Chemistry, Multidisciplinary SC Chemistry GA 279JQ UT WOS:000328956700065 ER PT J AU Cheng, SF Stevens, MJ AF Cheng, Shengfeng Stevens, Mark J. TI Self-assembly of chiral tubules SO SOFT MATTER LA English DT Article ID NANOTUBE ARCHITECTURES; MICROTUBULE LATTICE; POLYMERIZATION; NANOPARTICLES; NANOVESICLES; MECHANISM; MEMBRANE AB The efficient and controlled assembly of complex structures from macromolecular building blocks is a critical open question in both biological systems and nanoscience. Using molecular dynamics simulations we study the self-assembly of tubular structures from model macromolecular monomers with multiple binding sites on their surfaces. In this work we add chirality to the model monomer and a lock-and-key interaction. The self-assembly of free monomers into tubules yields a pitch value that often does not match the chirality of the monomer (including achiral monomers). We show that this mismatch occurs because of a twist deformation that brings the lateral interaction sites into alignment when the tubule pitch differs from the monomer chirality. The energy cost for this deformation is small as the energy distributions substantially overlap for small differences in the pitch and chirality. In order to control the tubule pitch by preventing the twist deformation, the interaction between the vertical surfaces must be increased without resulting in kinetically trapped structures. For this purpose, we employ lock-and-key interactions and obtain good control of the self-assembled tubule pitch. These results explain some fundamental features of microtubules. The vertical interaction strength is larger than the lateral in microtubules because this yields a controlled assembly of tubules with the proper pitch. We also generally find that the control of the assembly into tubules is difficult, which explains the wide range of pitch values and protofilament numbers observed in microtubule assembly. C1 [Cheng, Shengfeng; Stevens, Mark J.] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Cheng, SF (reprint author), Virginia Polytech Inst & State Univ, Dept Phys, Blacksburg, VA 24061 USA. EM chengsf@vt.edu; msteve@sandia.gov OI Cheng, Shengfeng/0000-0002-6066-2968 FU U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering [KC0203010]; U.S. Department of Energy's National Nuclear Security Administration [DE-AC04-94AL85000] FX This research was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Award KC0203010. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. NR 30 TC 6 Z9 6 U1 6 U2 50 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1744-683X EI 1744-6848 J9 SOFT MATTER JI Soft Matter PY 2014 VL 10 IS 3 BP 510 EP 518 DI 10.1039/c3sm52631c PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary; Physics, Multidisciplinary; Polymer Science SC Chemistry; Materials Science; Physics; Polymer Science GA 278JL UT WOS:000328886500012 PM 24652301 ER PT J AU Andrukh, T Monaenkova, D Rubin, B Lee, WK Kornev, KG AF Andrukh, Taras Monaenkova, Daria Rubin, Binyamin Lee, Wah-Keat Kornev, Konstantin G. TI Meniscus formation in a capillary and the role of contact line friction SO SOFT MATTER LA English DT Article ID CARBON NANOTUBES; HYDRODYNAMIC PECULIARITIES; SPONTANEOUS PENETRATION; VISCOELASTIC FLUIDS; MOLECULAR-DYNAMICS; RISE; LIQUIDS; FLOW; MEDIA; TUBES AB We studied spontaneous formation of an internal meniscus by dipping glass capillaries of 25 mm to 350 mm radii into low volatile hexadecane and tributyl phosphate. X-ray phase contrast and high speed optical microscopy imaging were employed. We showed that the meniscus completes its formation when the liquid column is still shorter than the capillary radius. After that, the meniscus travels about ten capillary radii at a constant velocity. We demonstrated that the experimental observations can be explained by introducing a friction force linearly proportional to the meniscus velocity with a friction coefficient depending on the air/liquid/solid triplet. It was demonstrated that the friction coefficient does not depend on the capillary radius. Numerical solution of the force balance equation revealed four different uptake regimes that can be specified in a phase portrait. This phase portrait was found to be in good agreement with the experimental results and can be used as a guide for the design of thin porous absorbers. C1 [Andrukh, Taras; Monaenkova, Daria; Rubin, Binyamin; Kornev, Konstantin G.] Clemson Univ, Dept Mat Sci & Engn, Clemson, SC 29634 USA. [Monaenkova, Daria] Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. [Lee, Wah-Keat] Brookhaven Natl Lab, Natl Synchrotron Light Source 2, Upton, NY 11973 USA. RP Kornev, KG (reprint author), Clemson Univ, Dept Mat Sci & Engn, Clemson, SC 29634 USA. EM kkornev@clemson.edu FU National Science Foundation [EFRI 0937985, PoLS 1305338]; Sigma Xi [G20100315153485, G20100315153500]; U.S. DOE [DE-AC02-06CH11357] FX The authors are grateful for the financial support from the National Science Foundation through Grant EFRI 0937985 and Grant PoLS 1305338. We also acknowledge Sigma Xi Grants-in-Aid of Research G20100315153485 and G20100315153500. Use of the Advanced Photon Source, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract no. DE-AC02-06CH11357. NR 56 TC 10 Z9 11 U1 6 U2 37 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1744-683X EI 1744-6848 J9 SOFT MATTER JI Soft Matter PY 2014 VL 10 IS 4 BP 609 EP 615 DI 10.1039/c3sm52164h PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary; Physics, Multidisciplinary; Polymer Science SC Chemistry; Materials Science; Physics; Polymer Science GA 279IZ UT WOS:000328954900010 PM 24652161 ER PT J AU Hejazi, M Edmonds, J Clarke, L Kyle, P Davies, E Chaturvedi, V Wise, M Patel, P Eom, J Calvin, K Moss, R Kim, S AF Hejazi, Mohamad Edmonds, James Clarke, Leon Kyle, Page Davies, Evan Chaturvedi, Vaibhav Wise, Marshall Patel, Pralit Eom, Jiyong Calvin, Katherine Moss, Richard Kim, Son TI Long-term global water projections using six socioeconomic scenarios in an integrated assessment modeling framework SO TECHNOLOGICAL FORECASTING AND SOCIAL CHANGE LA English DT Article DE Integrated assessment; GCAM; Socioeconomic scenarios; Water scarcity; Water withdrawals; Water consumption ID CLIMATE-CHANGE; ELECTRICITY-GENERATION; THERMOELECTRIC-POWER; ARAL SEA; RESOURCES; AVAILABILITY; FUTURE; WORLD; SCARCITY; DISASTER AB In this paper, we assess future water demands for the agricultural (irrigation and livestock), energy (electricity generation, primary energy production and processing), industrial (manufacturing and mining), and municipal sectors, by incorporating water demands into a technologically-detailed global integrated assessment model of energy, agriculture, and climate change - the Global Change Assessment Model (GCAM). Base-year water demands - both gross withdrawals and net consumptive use - are assigned to specific modeled activities in a way that maximizes consistency between bottom-up estimates of water demand intensities of specific technologies and practices, and top-down regional and sectoral estimates of water use. The energy, industrial, and municipal sectors are represented in fourteen geopolitical regions, with the agricultural sector further disaggregated into as many as eighteen agro-ecological zones (AEZs) within each region. We assess future water demands representing six socioeconomic scenarios, with no constraints imposed by future water supplies. The scenarios observe increases in global water withdrawals from 3710 km(3) year(-1) in 2005 to 6195-8690 km(3) year(-1) in 2050, and to 4869-12,693 km(3) year(-1) in 2095. Comparing the projected total regional water withdrawals to the historical supply of renewable freshwater, the Middle East exhibits the highest levels of water scarcity throughout the century, followed by India; water scarcity increases over time in both of these regions. In contrast, water scarcity improves in some regions with large base-year electric sector withdrawals, such as the USA and Canada, due to capital stock turnover and the almost complete phase-out of once-through flow cooling systems. The scenarios indicate that: 1) water is likely a limiting factor in meeting future water demands, 2) many regions can be expected to increase reliance on non-renewable groundwater, water reuse, and desalinated water, but they also highlight an important role for development and deployment of water conservation technologies and practices. (C) 2013 Elsevier Inc. All rights reserved. C1 [Hejazi, Mohamad; Edmonds, James; Clarke, Leon; Kyle, Page; Chaturvedi, Vaibhav; Wise, Marshall; Patel, Pralit; Calvin, Katherine; Moss, Richard; Kim, Son] Pacific NW Natl Lab, Joint Global Change Res Inst, College Pk, MD USA. [Davies, Evan] Univ Alberta, Dept Civil & Environm Engn, Edmonton, AB T6G 2M7, Canada. [Eom, Jiyong] Sogang Univ, Grad Sch Management Technol, Seoul, South Korea. RP Hejazi, M (reprint author), Pacific NW Natl Lab, Joint Global Change Res Inst, College Pk, MD USA. EM mohamad.hejazi@pnnl.gov RI Eom, Jiyong/A-1161-2014; Davies, Evan/A-3379-2008; OI Davies, Evan/0000-0003-0536-333X; Calvin, Katherine/0000-0003-2191-4189; Moss, Richard/0000-0001-5005-0063 NR 99 TC 33 Z9 34 U1 11 U2 62 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0040-1625 EI 1873-5509 J9 TECHNOL FORECAST SOC JI Technol. Forecast. Soc. Chang. PD JAN PY 2014 VL 81 BP 205 EP 226 DI 10.1016/j.techfore.2013.05.006 PG 22 WC Business; Planning & Development SC Business & Economics; Public Administration GA 278YP UT WOS:000328926100017 ER PT J AU Cantwell, PR Tang, M Dillon, SJ Luo, J Rohrer, GS Harmer, MP AF Cantwell, Patrick R. Tang, Ming Dillon, Shen J. Luo, Jian Rohrer, Gregory S. Harmer, Martin P. TI Grain boundary complexions SO ACTA MATERIALIA LA English DT Article DE Grain boundary; Complexions; Phases; Transitions; Kinetics ID MOLECULAR-DYNAMICS SIMULATIONS; INTERGRANULAR AMORPHOUS FILMS; PRESSED SILICON-NITRIDE; DISPLAYING DIFFERENT COMPLEXIONS; SCANNING-TUNNELING-MICROSCOPY; 96-PERCENT ALUMINA CERAMICS; VACANCY FORMATION ENERGIES; GLYCOL SOLUTION INTERFACE; CREEP-RESISTANT ALUMINA; AU-SAPPHIRE INTERFACES AB Grain boundaries exhibit phase-like behavior in which their structure, chemistry and properties may change discontinuously at critical values of thermodynamic parameters such as temperature, pressure and chemical potential. Therefore, grain boundaries (and other interfaces such as surfaces and heterophase boundaries) can be treated as thermodynamically stable interfacial states. To differentiate these interfacial states from bulk phases, the term "complexion" has been introduced. A variety of terminology has been used to describe complexions and complexion transitions. In many cases, several terms exist that describe essentially the same phenomenon. We give an overview of complexion-related terminology, suggest a preferred nomenclature and discuss a classification framework that can be used to categorize complexions and complexion transitions. The field of grain boundary complexions has evolved rapidly in the past decade due to advances in experimental equipment - in particular, aberration-corrected transmission electron microscopy - and progress in computational simulation methods. Grain boundary complexion transitions are the root cause of a wide variety of materials phenomena - such as abnormal grain growth, grain boundary embrittlement and activated sintering - that have defied mechanistic explanation for years. In this overview, we review the history and theory of grain boundary complexion transitions, their role in materials processing and their effect on materials properties. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. C1 [Cantwell, Patrick R.; Harmer, Martin P.] Lehigh Univ, Ctr Adv Mat & Nanotechnol, Dept Mat Sci & Engn, Bethlehem, PA 18015 USA. [Tang, Ming] Lawrence Livermore Natl Lab, Condensed Matter & Mat Div, Livermore, CA 94550 USA. [Dillon, Shen J.] Univ Illinois, Dept Mat Sci & Engn, Urbana, IL 61801 USA. [Luo, Jian] Univ Calif San Diego, Dept NanoEngn, Program Mat Sci & Engn, La Jolla, CA 92093 USA. [Rohrer, Gregory S.] Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. RP Harmer, MP (reprint author), Lehigh Univ, Ctr Adv Mat & Nanotechnol, Dept Mat Sci & Engn, Bethlehem, PA 18015 USA. EM mph2@lehigh.edu RI dillon, shen/N-1850-2013; Albe, Karsten/F-1139-2011; Rohrer, Gregory/A-9420-2008; Luo, Jian/A-4777-2008 OI dillon, shen/0000-0002-6192-4026; Rohrer, Gregory/0000-0002-9671-3034; FU ONR-MURI [N00014-11-1-0678]; Office of Basic Energy Sciences (OBES), Materials Science Division (MSD) under the U.S. Department of Energy by Lawrence Livermore National Laboratory [DE-AC52-07NA27344] FX The authors would like to gratefully acknowledge W. Craig Carter (MIT) for the refined definition of complexions used in this overview, and to thank Paul Wynblatt (Carnegie Mellon University), Jeffrey M. Rickman (Lehigh University), and Andrea J. Harmer (Kutztown University) for helpful discussions, suggestions, and edits. Naixie Zhou (UCSD) drew an initial version of Fig. 5. The authors are indebted to the reviewer, who carefully analyzed the manuscript and offered many insightful and beneficial comments. Financial support from the ONR-MURI under the grant no. N00014-11-1-0678 monitored by David Shifler is gratefully acknowledged by PRC, SJD, JL, GSR, and MPH. MT acknowledges support by the Office of Basic Energy Sciences (OBES), Materials Science Division (MSD), under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. NR 344 TC 120 Z9 122 U1 35 U2 224 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 EI 1873-2453 J9 ACTA MATER JI Acta Mater. PD JAN PY 2014 VL 62 BP 1 EP 48 DI 10.1016/j.actamat.2013.07.037 PG 48 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 274GK UT WOS:000328594600001 ER PT J AU Chapman, KW Chupas, PJ Long, GG Bendersky, LA Levine, LE Mompiou, F Stalick, JK Cahn, JW AF Chapman, Karena W. Chupas, Peter J. Long, Gabrielle G. Bendersky, Leonid A. Levine, Lyle E. Mompiou, Frederic Stalick, Judith K. Cahn, John W. TI An ordered metallic glass solid solution phase that grows from the melt like a crystal SO ACTA MATERIALIA LA English DT Article DE Metallic glass; Phase transformation; Pair distribution function analysis; X-ray scattering ID PAIR DISTRIBUTION FUNCTION; HIGH-RESOLUTION; DIFFRACTION; REFINEMENT; DETECTOR; ALLOYS AB We report structural studies of an Al-Fe-Si glassy solid that is a solid solution phase in the classical thermodynamic sense. We demonstrate that it is neither a frozen melt nor nanocrystalline. The glass has a well-defined solubility limit and rejects Al during formation from the melt. The pair distribution function of the glass reveals chemical ordering out to at least 12 angstrom that resembles the ordering within a stable crystalline intermetallic phase of neighboring composition. Under isothermal annealling at 305 degrees C the glass first rejects Al, then persists for approximately 1 h with no detectable change in structure, and finally is transformed by a first-order phase transition to a crystalline phase with a structure that is different from that within the glass. It is possible that this remarkable glass phase has a fully ordered atomic structure that nevertheless possesses no long-range translational symmetry and is isotropic. Published by Elsevier Ltd. on behalf of Acta Materialia Inc. C1 [Chapman, Karena W.; Chupas, Peter J.; Long, Gabrielle G.] Argonne Natl Lab, Xray Sci Div, Argonne, IL 60439 USA. [Long, Gabrielle G.; Bendersky, Leonid A.; Levine, Lyle E.; Mompiou, Frederic; Cahn, John W.] NIST, Mat Sci & Engn Div, Gaithersburg, MD 20899 USA. [Mompiou, Frederic] CNRS, Ctr Elaborat Mat & Etud Struct, F-31055 Toulouse, France. [Stalick, Judith K.] NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. [Cahn, John W.] Univ Washington, Dept Phys & Astron, Seattle, WA 98195 USA. RP Long, GG (reprint author), Argonne Natl Lab, Xray Sci Div, Argonne, IL 60439 USA. EM gglong@aps.anl.gov FU DOE [DE-AC02-06CH11357] FX The authors acknowledge Frank Biancaniello for alloy preparation and Alexander Shapiro for assistance with the SEM measurements. We also thank Maureen Williams for X-ray characterization and Kil-Won Moon for isothermal calorimetry. We thank Marjorie Senechal for useful discussions. The X-ray studies were conducted at beamlines 1-ID, 11-ID and 32-ID at the Advanced Photon Source (APS). This research would not have been possible without the unique capabilities of the dedicated pair distribution function X-ray scattering instrument at 11-ID-B at the APS. This instrument provides data over a broad range in Fourier space, offering the necessary high spatial resolution at intermediate length scales (6-20 angstrom). It is adequately sensitive to probe very small sample volumes (103 mu m3) and still provide adequate counting statistics to perform in situ real time measurements of phase transformations. The APS is an Office of Science User Facility operated for the US Department of Energy (DOE) Office of Science by Argonne National Laboratory, and was supported by the DOE under contract no. DE-AC02-06CH11357. NR 30 TC 3 Z9 3 U1 5 U2 38 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 EI 1873-2453 J9 ACTA MATER JI Acta Mater. PD JAN PY 2014 VL 62 BP 58 EP 68 DI 10.1016/j.actamat.2013.08.063 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 274GK UT WOS:000328594600003 ER PT J AU Fattebert, JL Wickett, ME Turchi, PEA AF Fattebert, J. -L. Wickett, M. E. Turchi, P. E. A. TI Phase-field modeling of coring during solidification of Au-Ni alloy using quaternions and CALPHAD input SO ACTA MATERIALIA LA English DT Article DE Phase-field model; Alloy; Solidification; CALPHAD; Numerical method ID THERMO-CALC; SIMULATION; DIFFUSION; EVOLUTION; SYSTEM; TRANSFORMATIONS; DICTRA AB A numerical method for the simulation of microstructure evolution during the solidification of an alloy is presented. The approach is based on a phase-field model including a phase variable, an orientation variable given by a quaternion, the alloy composition and a uniform temperature field. Energies and diffusion coefficients used in the model rely on thermodynamic and kinetic databases in the framework of the CALPHAD methodology. The numerical approach is based on a finite volume discretization and an implicit time-stepping algorithm. Numerical results for solidification and accompanying coring effect in a Au-Ni alloy are used to illustrate the methodology. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. C1 [Fattebert, J. -L.] Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. [Wickett, M. E.] Lawrence Livermore Natl Lab, WCI Div B, Livermore, CA 94551 USA. [Turchi, P. E. A.] Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Fattebert, JL (reprint author), Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, L-561, Livermore, CA 94551 USA. EM fattebert1@llnl.gov; wickettl@llnl.gov; turchi1@llnl.gov FU US Department of Energy by Lawrence Livermore National Laboratory [DE-AC52-07NA27344]; Laboratory Directed Research and Development Program [12-SI-008] FX The authors are grateful to Nele Moelans, Ming Tang and Milo Dorr for useful discussions. P.T. would also like to thank Lars Hoglund for useful insights. This work was performed under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Work at LLNL was funded by the Laboratory Directed Research and Development Program under project tracking code 12-SI-008. NR 34 TC 10 Z9 10 U1 2 U2 28 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 EI 1873-2453 J9 ACTA MATER JI Acta Mater. PD JAN PY 2014 VL 62 BP 89 EP 104 DI 10.1016/j.actamat.2013.09.036 PG 16 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 274GK UT WOS:000328594600006 ER PT J AU Parish, CM Hijazi, H Meyer, HM Meyer, FW AF Parish, C. M. Hijazi, H. Meyer, H. M. Meyer, F. W. TI Effect of tungsten crystallographic orientation on He-ion-induced surface morphology changes SO ACTA MATERIALIA LA English DT Article DE Tungsten; Electron backscatter diffraction; Ion irradiation; Helium; Dislocation loop punching ID LOW-ENERGY; BUBBLE; IRRADIATION; MOLYBDENUM; GROWTH; METALS; BCC; CU AB In order to study the early stages of nanofuzz growth in fusion-plasma-facing tungsten, mirror-polished high-purity tungsten was exposed to 80 eV helium at 1130 degrees C to a fluence of 4 x 10(24) He m(-2). The previously smooth surface shows morphology changes, and grains form one of four qualitatively different morphologies: smooth, wavy, pyramidal or terraced/wide waves. Combining high-resolution scanning electron microscopy (SEM) observations to determine the morphology of each grain with quantitative measurement of the grain's orientation via electron backscatter diffraction in SEM shows that the normal-direction crystallographic orientation of the underlying grain controls the growth morphology. Specifically, near-< 0 0 1 > parallel to normal direction (ND) grains formed pyramids, near-< 1 1 4 > to < 1 1 2 > parallel to ND grains formed wavy and stepped structures and near-< 1 0 3 > parallel to ND grains remained smooth. Comparisons to control specimens indicate no changes to underlying bulk crystallographic texture, and possible explanations of the structure growth, particularly loop-punching, are discussed. Future developments to control tungsten texture via thermomechanical processing, ideally obtaining a sharp near-< 1 0 3 > parallel to ND processing texture, may delay the formation of nanofuzz. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. C1 [Parish, C. M.; Meyer, H. M.] Oak Ridge Natl Lab, Div Mat Sci & Technol, Oak Ridge, TN 37831 USA. [Hijazi, H.; Meyer, F. W.] Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RP Meyer, FW (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. EM meyerfw@ornl.gov RI Parish, Chad/J-8381-2013 FU LDRD Program of Oak Ridge National Laboratory; Office of Basic Energy Sciences, US Department of Energy FX This research was sponsored by the LDRD Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the US Department of Energy. HH was appointed through the ORNL Postdoctoral Research Associates Program administered jointly by Oak Ridge Institute of Science and Education (ORISE), Oak Ridge Associated Universities (ORAU) and Oak Ridge National Laboratory (ORNL). Work performed in part via Oak Ridge National Laboratory's Shared Research Equipment (ShaRE) User Program, which is sponsored by the Office of Basic Energy Sciences, US Department of Energy. Thanks to Dr. Lucille Giannuzzi, L.A. Giannuzzi & Associates LLC, for discussions regarding ion channeling. Thanks to Dr. Maxim Gussev, ORNL, for critiquing the manuscript. NR 39 TC 21 Z9 24 U1 6 U2 53 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 EI 1873-2453 J9 ACTA MATER JI Acta Mater. PD JAN PY 2014 VL 62 BP 173 EP 181 DI 10.1016/j.actamat.2013.09.045 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 274GK UT WOS:000328594600014 ER PT J AU Wang, T Cullinan, TE Napolitano, RE AF Wang, Tao Cullinan, T. E. Napolitano, R. E. TI A new method for measuring the thermodynamic properties of undercooled liquid and amorphous Cu-Zr alloys SO ACTA MATERIALIA LA English DT Article DE Undercooled liquid; Heat capacity measurement; Cu-Zr; Glass-forming alloys; Thermodynamics ID GLASS-TRANSITION; ELECTROSTATIC LEVITATION; THERMOPHYSICAL PROPERTIES; PHASE-EQUILIBRIA; SYSTEM; MELTS; HEAT; TEMPERATURE; ENTHALPY; SI AB A new method for the experimental determination of the temperature-dependent heat capacity is presented here. The value of this new method lies principally in its applicability to unstable systems, where time-dependent relaxation processes limit the utility of conventional stepwise methods that employ a series of isothermal holding periods. The method is demonstrated for two glass-forming alloys (Cu50Zr50 and Cu64.5Zr35.5), using differential scanning calorimetry (DSC) measurements over a (low) temperature regime including stable, metastable and unstable states (crystalline, glass and undercooled liquid). For this specific analysis, the glassy material is heated using several different rates, each resulting in a different transformation temperature. After characterization of the final states, analysis of the DSC traces yields the requisite transition enthalpies, enabling determination of the heat capacities, based on common reference states. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. C1 [Wang, Tao; Napolitano, R. E.] US DOE, Ames Lab, Div Mat Sci & Engn, Ames, IA 50011 USA. [Cullinan, T. E.; Napolitano, R. E.] Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Napolitano, RE (reprint author), US DOE, Ames Lab, Div Mat Sci & Engn, Ames, IA 50011 USA. EM ren1@iastate.edu FU US Department of Energy, Office of Basic Energy Science, Division of Materials Sciences and Engineering; US Department of Energy by Iowa State University [DE-AC02-07CH11358] FX This work was supported by the US Department of Energy, Office of Basic Energy Science, Division of Materials Sciences and Engineering. The research was performed at the Ames Laboratory. Ames Laboratory is operated for the US Department of Energy by Iowa State University under Contract No. DE-AC02-07CH11358. NR 39 TC 5 Z9 5 U1 5 U2 52 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 EI 1873-2453 J9 ACTA MATER JI Acta Mater. PD JAN PY 2014 VL 62 BP 188 EP 196 DI 10.1016/j.actamat.2013.09.047 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 274GK UT WOS:000328594600016 ER PT J AU Wang, LY Li, MM Almer, J AF Wang, Leyun Li, Meimei Almer, Jonathan TI Investigation of deformation and microstructural evolution in Grade 91 ferritic-martensitic steel by in situ high-energy X-rays SO ACTA MATERIALIA LA English DT Article DE In situ tensile test; High-energy X-ray diffraction; Steels; Lattice strains; Dislocation structure ID DISLOCATION SUBSTRUCTURE; TENSILE DEFORMATION; NEUTRON-DIFFRACTION; RESISTANT STEELS; STAINLESS-STEEL; LINE-PROFILES; HIGH-STRENGTH; POWER-PLANT; FLOW-STRESS; TEMPERATURE AB In situ wide- and small-angle X-ray scattering (WAXS/SAXS) were used to characterize microstructural evolution in Grade 91 ferritic-martensitic steel during tensile tests at room temperature (RT) and 650 degrees C. Elastic lattice strains in the Fe matrix, M23C6 and MX precipitates were measured from peak shifts in WAXS patterns. Load transfer, as evidenced by precipitates developing much higher lattice strain than the Fe matrix in the plastic regime, was found for the RT test but was not obvious at 650 degrees C. Detailed peak-broadening analysis as a function of strain, using modified Williamson-Hall plots, indicates strong dislocation activity in the Fe matrix during the RT test which can be divided into two stages: (i) dislocation multiplication (from 0 to 4.0% strain) and (ii) formation of dislocation walls and cells (after 4.0% strain). This framework is consistent with the observed precipitate strain response and can describe the macroscopic flow stress behavior. At 650 degrees C, Fe peaks broadened much less with increasing strain, indicating a low dislocation density and providing an explanation for the low precipitate strains and macroscopic flow stress at this temperature. Changes in SAXS intensity were used to infer nanoscale void formation, which occurred immediately after necking at RT but long after necking at 650 degrees C. Most voids were concentrated at the necking center, and the RT specimen developed more voids than the 650 degrees C specimen. Published by Elsevier Ltd. on behalf of Acta Materialia Inc. C1 [Wang, Leyun; Li, Meimei; Almer, Jonathan] Argonne Natl Lab, Argonne, IL 60439 USA. RP Wang, LY (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM wly857@gmail.com FU U.S. Department of Energy [DE-AC02-06CH11357]; U.S. Department of Energy, Office of Science; U.S. Department of Energy Office of Science Laboratory by UChicago Argonne, LLC. [DE-AC02-06CH11357] FX This work was supported under the U.S. Department of Energy contract DE-AC02-06CH11357. Use of the Advanced Photon Source is supported by the U.S. Department of Energy, Office of Science. The electron microscopy was accomplished at the Electron Microscopy Center at Argonne National Laboratory, a U.S. Department of Energy Office of Science Laboratory operated under Contract No. DE-AC02-06CH11357 by UChicago Argonne, LLC. We also appreciate valuable discussions with Dr. Jan Ilavsky on SAXS data analysis. NR 50 TC 22 Z9 22 U1 1 U2 45 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 EI 1873-2453 J9 ACTA MATER JI Acta Mater. PD JAN PY 2014 VL 62 BP 239 EP 249 DI 10.1016/j.actamat.2013.10.003 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 274GK UT WOS:000328594600020 ER PT J AU Zhang, YQ He, WD Wen, KC Wang, XN Lu, HL Lin, X Dickerson, JH AF Zhang, Yuqian He, Weidong Wen, Kechun Wang, Xiaoning Lu, Hongliang Lin, Xiao Dickerson, James H. TI Quantitative evaluation of Coulombic interactions in the oriented-attachment growth of nanotubes SO ANALYST LA English DT Article ID NANORODS; NANOCRYSTALS; NANOPARTICLE; NANOWIRES AB The Coulombic interaction in the oriented attachment growth of one-dimensional nanotubes is evaluated via a newly-derived analytical expression of the Coulombic interactions between a spherical attaching nanoparticle and a growing nanotube. The correlation between the interaction and the important growth parameters, including nanoparticle/nanotube size, aspect ratio, and nanoparticle-nanotube separation has been analyzed. Our work provides, for the first time, an efficient platform to investigate the growth kinetics and mechanisms of oriented attachment growth of nanotubes. C1 [Zhang, Yuqian; He, Weidong; Wen, Kechun; Wang, Xiaoning] UESTC, Sch Energy Sci & Engn, Chengdu 611731, Peoples R China. [Lu, Hongliang; Lin, Xiao] Univ Chinese Acad Sci, Sch Phys, Beijing 100049, Peoples R China. [Dickerson, James H.] Brookhaven Natl Lab, Ctr Funct Nanomat, Upton, NY 11973 USA. [Dickerson, James H.] Brown Univ, Dept Phys, Providence, RI 02912 USA. RP He, WD (reprint author), UESTC, Sch Energy Sci & Engn, Chengdu 611731, Peoples R China. EM weidong.he@uestc.edu.cn RI Dickerson, James/F-7950-2013; Lin, Xiao/B-5055-2009 OI Dickerson, James/0000-0001-9636-6303; FU UESTC new faculty startup fund; U.S. Department of Energy, Office of Basic Energy Sciences [DE-AC02-98CH10886] FX The work is supported in part by the UESTC new faculty startup fund. Research was carried out in part at the Center for Functional Nanomaterials, Brookhaven National Laboratory, which is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract no. DE-AC02-98CH10886. NR 27 TC 7 Z9 7 U1 2 U2 11 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 0003-2654 EI 1364-5528 J9 ANALYST JI Analyst PY 2014 VL 139 IS 2 BP 371 EP 374 DI 10.1039/c3an01261a PG 4 WC Chemistry, Analytical SC Chemistry GA 274YS UT WOS:000328642700003 PM 24255914 ER PT J AU Barth, AJ Voevodkin, A Carson, DJ Wozniak, P AF Barth, Aaron J. Voevodkin, Alexey Carson, Daniel J. Wozniak, Przemyslaw TI A SEARCH FOR OPTICAL VARIABILITY OF TYPE 2 QUASARS IN SDSS STRIPE 82 SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies: active; galaxies: nuclei; galaxies: photometry; polarization; quasars: general ID DIGITAL-SKY-SURVEY; ACTIVE GALACTIC NUCLEI; BROAD-LINE REGIONS; SEYFERT 2 GALAXIES; X-RAY-ABSORPTION; EMISSION-LINES; DATA RELEASE; II QUASARS; COLOR VARIABILITY; EDDINGTON-RATIO AB Hundreds of Type 2 quasars have been identified in Sloan Digital Sky Survey (SDSS) data, and there is substantial evidence that they are generally galaxies with highly obscured central engines, in accord with unified models for active galactic nuclei (AGNs). A straightforward expectation of unified models is that highly obscured Type 2 AGNs should show little or no optical variability on timescales of days to years. As a test of this prediction, we have carried out a search for variability in Type 2 quasars in SDSS Stripe 82 using difference-imaging photometry. Starting with the Type 2 AGN catalogs of Zakamska et al. and Reyes et al., we find evidence of significant g-band variability in 17 out of 173 objects for which light curves could be measured from the Stripe 82 data. To determine the nature of this variability, we obtained new Keck spectropolarimetry observations for seven of these variable AGNs. The Keck data show that these objects have low continuum polarizations (p less than or similar to 1% in most cases) and all seven have broad H alpha and/or Mg II emission lines in their total (unpolarized) spectra, indicating that they should actually be classified as Type 1 AGNs. We conclude that the primary reason variability is found in the SDSS-selected Type 2 AGN samples is that these samples contain a small fraction of Type 1 AGNs as contaminants, and it is not necessary to invoke more exotic possible explanations such as a population of "naked" or unobscured Type 2 quasars. Aside from misclassified Type 1 objects, the Type 2 quasars do not generally show detectable optical variability over the duration of the Stripe 82 survey. C1 [Barth, Aaron J.; Carson, Daniel J.] Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA. [Voevodkin, Alexey] Space Res Inst IKI, Moscow 117997, Russia. [Voevodkin, Alexey; Wozniak, Przemyslaw] Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Barth, AJ (reprint author), Univ Calif Irvine, Dept Phys & Astron, 4129 Frederick Reines Hall, Irvine, CA 92697 USA. EM barth@uci.edu OI Wozniak, Przemyslaw/0000-0002-9919-3310; Barth, Aaron/0000-0002-3026-0562 FU NSF [AST-1108835]; Laboratory Directed Research and Development program; Alfred P. Sloan Foundation; National Science Foundation; U.S. Department of Energy; National Aeronautics and Space Administration; Japanese Monbukagakusho; Max Planck Society; Higher Education Funding Council for England; American Museum of Natural History; Astrophysical Institute Potsdam; University of Basel; University of Cambridge; Case Western Reserve University; University of Chicago; Drexel University; Fermilab; Institute for Advanced Study; Japan Participation Group; Johns Hopkins University; Joint Institute for Nuclear Astrophysics; Kavli Institute for Particle Astrophysics and Cosmology; Korean Scientist Group; Chinese Academy of Sciences (LAMOST); Los Alamos National Laboratory; Max-PlanckInstitute for Astronomy (MPIA); Max-Planck-Institute for Astrophysics (MPA); New Mexico State University; Ohio State University; University of Pittsburgh; University of Portsmouth; Princeton University; United States Naval Observatory; University of Washington; W.M. Keck Foundation; [RFFI 12-02-01358] FX Research by A. J. B. and D. J. C. is supported by NSF grant AST-1108835. A.V. acknowledges support from the research grant RFFI 12-02-01358. We thank Shawn Thorman for his contributions to a preliminary version of this project. The work at LANL was supported by the Laboratory Directed Research and Development program. We thank the referee for helpful suggestions that improved this paper.; Funding for the SDSS and SDSS-II has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the U.S. Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society, and the Higher Education Funding Council for England. The SDSS Web site is http://www.sdss.org/.; The SDSS is managed by the Astrophysical Research Consortium for the Participating Institutions. The Participating Institutions are the American Museum of Natural History, Astrophysical Institute Potsdam, University of Basel, University of Cambridge, Case Western Reserve University, University of Chicago, Drexel University, Fermilab, the Institute for Advanced Study, the Japan Participation Group, Johns Hopkins University, the Joint Institute for Nuclear Astrophysics, the Kavli Institute for Particle Astrophysics and Cosmology, the Korean Scientist Group, the Chinese Academy of Sciences (LAMOST), Los Alamos National Laboratory, the Max-PlanckInstitute for Astronomy (MPIA), the Max-Planck-Institute for Astrophysics (MPA), New Mexico State University, Ohio State University, University of Pittsburgh, University of Portsmouth, Princeton University, the United States Naval Observatory, and the University of Washington.; Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. NR 85 TC 4 Z9 4 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 EI 1538-3881 J9 ASTRON J JI Astron. J. PD JAN PY 2014 VL 147 IS 1 AR 12 DI 10.1088/0004-6256/147/1/12 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 275RH UT WOS:000328694500012 ER PT J AU Croshaw, DA AF Croshaw, Dean A. TI Singly laid mole salamander (Ambystoma talpoideum) eggs resist mortality from water mold infection SO BEHAVIOUR LA English DT Article DE single oviposition; amphibian; egg infection; mole salamander; water mold; reproductive strategy ID OVIPOSITION BEHAVIOR; WRAPPING BEHAVIOR; PACIFIC-NORTHWEST; AMPHIBIAN EGGS; EVOLUTION; DISEASE; NEWT; SUSCEPTIBILITY; SAPROLEGNIA; PREDATION AB Parasites and pathogens are noteworthy forces in evolutionary and population biology. Water molds are known to infect and kill amphibian eggs, and masses placed in clusters sometimes suffer greater losses. Thus, selection may favor single oviposition behavior in which female's scatter individual eggs to avoid contact with dead eggs, thereby lowering the chances of hyphal spread. I tested the hypothesis that eggs in physical contact with dead eggs are more susceptible to death via pathogen infection using a singly laying urodele, the mole salamander, whose congeners mostly lay eggs in masses. Focal eggs were placed in replicated containers with variable egg contact (physically touching or separated) by treatment eggs that varied in status (dead or alive). The effect of egg arrangement was significant, with focal eggs surviving better to hatching when not contacting treatment eggs. Although treatment egg status (dead vs. alive) was not influential on its own, the interaction between egg contact and status was an important determinant of focal egg survival. Only when eggs were physically touching was it important whether they were dead or alive. Moreover, when eggs were touching there was a significant positive association between focal egg survival and the number of surviving treatment eggs. Water mold infected most dead eggs in all treatment groups. This study shows that mole salamander eggs are more likely to die when touching other eggs that have perished, most likely because of a greater chance of water mold infection. Such mortality may have contributed to diversification of egg-laying behavior in amphibians and shows a potentially compounding fitness cost of diminished fertilization success and embryo viability. C1 [Croshaw, Dean A.] Florida Gulf Coast Univ, Dept Biol Sci, Ft Myers, FL 33965 USA. [Croshaw, Dean A.] Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Croshaw, DA (reprint author), Florida Gulf Coast Univ, Dept Biol Sci, Ft Myers, FL 33965 USA. EM dcroshaw@fgcu.edu FU University of New Orleans; U.S. Department of Energy [DE-FC09-96SR18546] FX I thank B. Hopkins for use of aquaria and space at the SREL Aquatic Ecology Lab. D. Scott generously offered use of his study site and drift fences, and J. Neamon helped with logistics. Support and funding were provided by a Board of Regents Superior Graduate Fellowship from the University of New Orleans and award DE-FC09-96SR18546 from the U.S. Department of Energy to the University of Georgia Research Foundation. The procedures used in this study were approved by a permit issued by the Institutional Animal Care and Use Committee of the University of Georgia, permit number A2003-10024-C2, "Reptile and amphibian research-general field studies." All salamanders were released at the collection site upon the conclusion of the experiment. NR 33 TC 0 Z9 0 U1 1 U2 16 PU BRILL ACADEMIC PUBLISHERS PI LEIDEN PA PLANTIJNSTRAAT 2, P O BOX 9000, 2300 PA LEIDEN, NETHERLANDS SN 0005-7959 EI 1568-539X J9 BEHAVIOUR JI Behaviour PY 2014 VL 151 IS 1 BP 125 EP 136 DI 10.1163/1568539X-00003126 PG 12 WC Behavioral Sciences; Zoology SC Behavioral Sciences; Zoology GA 275DZ UT WOS:000328657800007 ER PT J AU Ginovska-Pangovska, B Ho, MH Linehan, JC Cheng, YH Dupuis, M Raugei, S Shaw, WJ AF Ginovska-Pangovska, Bojana Ho, Ming-Hsun Linehan, John C. Cheng, Yuhui Dupuis, Michel Raugei, Simone Shaw, Wendy J. TI Molecular dynamics study of the proposed proton transport pathways in [FeFe]-hydrogenase SO BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS LA English DT Article DE [FeFe]-hydrogenase; Hydrogen bonding; Molecular dynamics; Proton transport; Mutations ID CLOSTRIDIUM-PASTEURIANUM; FEFE HYDROGENASES; PROTEINS; CHANNELS; SIMULATION; RESOLUTION; GROTTHUSS; MECHANISM; CLUSTER; NIFE AB Possible proton transport pathways in Clostridium pasteurianum (CpI) [FeFe]-hydrogenase were investigated with molecular dynamics simulations. This study was undertaken to evaluate the functional pathway and provide insight into the hydrogen bonding features defining an active proton transport pathway. Three pathways were evaluated, two of which consist of water wires and one of predominantly amino acid residues. Our simulations suggest that protons are not transported through water wires. Instead, the five-residue motif (Glu282, Ser319, Glu279, H2O, Cys299) was found to be the likely pathway, consistent with previously made experimental observations. The pathway was found to have a persistent hydrogen bonded core (residues Cys299 to Ser319), with less persistent hydrogen bonds at the ends of the pathway for both H-2 release and H-2 uptake. Single site mutations of the four residues have been shown experimentally to deactivate the enzyme. The theoretical evaluation of these mutations demonstrates redistribution of the hydrogen bonds in the pathway, resulting in enzyme deactivation. Finally, coupling between the protein dynamics near the proton transport pathway and the redox partner binding regions was also found as a function of H-2 uptake and H-2 release states, which may be indicative of a correlation between proton and electron movement within the enzyme. (C) 2013 Elsevier B.V. All rights reserved. C1 [Ginovska-Pangovska, Bojana; Ho, Ming-Hsun; Linehan, John C.; Cheng, Yuhui; Dupuis, Michel; Raugei, Simone; Shaw, Wendy J.] Pacific NW Natl Lab, Richland, WA 99352 USA. RP Raugei, S (reprint author), POB 999,MS K1-83, Richland, WA 99352 USA. EM simone.raugei@pnnl.gov; Wendy.shaw@pnnl.gov FU DOE Office of Science Early Career Research Program through Office of Basic Energy Sciences; Department of Energy's Office of Biological and Environmental Research located at Pacific Northwest National Laboratory; PNNL Institutional Computing at Pacific Northwest National Laboratory FX The authors would like to thank Eric Hegg and Adam Cornish for useful discussions. This work was funded by the DOE Office of Science Early Career Research Program through the Office of Basic Energy Sciences. Computational resources were provided at W. R. Wiley Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research located at Pacific Northwest National Laboratory, and a portion of the research was performed using PNNL Institutional Computing at Pacific Northwest National Laboratory. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy. Supporting materials may be accessed free of charge online at http://pubs.acs.org. NR 45 TC 22 Z9 22 U1 0 U2 47 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0005-2728 EI 0006-3002 J9 BBA-BIOENERGETICS JI Biochim. Biophys. Acta-Bioenerg. PD JAN PY 2014 VL 1837 IS 1 BP 131 EP 138 DI 10.1016/j.bbabio.2013.08.004 PG 8 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 276CD UT WOS:000328724800012 PM 23981729 ER PT J AU Parker, ST Lorenzetti, DM Sohn, MD AF Parker, Simon T. Lorenzetti, David M. Sohn, Michael D. TI Implementing state-space methods for multizone contaminant transport SO BUILDING AND ENVIRONMENT LA English DT Article DE Multizone models; Concentration solution; Indoor dispersion; Numerical methods; State-space; Eigenvalue ID AIR-FLOW MODELS; BUILDINGS; SYSTEMS; MATRIX; PREDICTION; COMIS; PERFORMANCE; VENTILATION; ENVIRONMENT; SOFTWARE AB The "well-mixed zone" approximation is a useful model for simulating contaminant transport in buildings. Multizone software tools such as CONTAM [1] and COMIS [2] use time-marching numerical methods to solve the resulting ordinary differential equations. By contrast, the state-space approach solves the same equations analytically [3]. A direct analytical solution, using the matrix exponential, is computationally attractive for certain applications, for example, when the airflows do not change for relatively long periods. However, for large systems, even the matrix exponential requires numerical estimation. This paper evaluates two methods for finding the matrix exponential: eigenvalue decomposition, and the Pade algorithm. In addition, it considers a variation optimised for sparse matrices, and compares against a reference backward Euler time-marching scheme. The state-space solutions can run several orders of magnitude faster than the reference method, with more significant speedups for a greater number of zones. This makes them especially valuable for applications where rapid calculation of concentration and exposure under constant air flow conditions are needed, such as real-time forecasting or monitoring of indoor contaminants. For most models, all three methods have low errors (magnitude of median fractional bias <3.10(-5), normalised mean square error <3.10(-7), and scaled absolute error <4.10(-4)). However, for the largest model considered (1701 zones) eigenvalue decomposition showed a dramatic increase in error. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved. C1 [Parker, Simon T.] Dstl, Salisbury SP4 0JQ, Wilts, England. [Lorenzetti, David M.; Sohn, Michael D.] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RP Parker, ST (reprint author), Dstl, Salisbury SP4 0JQ, Wilts, England. EM stparker@dstl.gov.uk; DMLorenzetti@lbl.gov; MDSohn@lbl.gov OI Parker, Simon/0000-0002-9451-3987 FU Dstl Research Scholarship scheme; Defense Threat Reduction Agency; U.S. Department of Energy [DE-AC02-05CH11231] FX Thanks are expressed to the organisers of, and attendees at, the 80th European Study Group with Industry held at Cardiff University in 2011, for their contribution to the use of analytical state-space methods for multizone models. The authors are also grateful to David Allwright from the Smiths Institute, Oxford for drawing their attention to recent work on the efficient solution of matrix exponential vector products. This work was made possible by the public availability of a database of multizone models for residential buildings from the National Institute of Standards and Technology for which we are most grateful. Parker was supported by the Dstl Research Scholarship scheme. Lorenzetti and Sohn were supported in part by the Defense Threat Reduction Agency, and performed under U.S. Department of Energy Contract number DE-AC02-05CH11231. NR 45 TC 4 Z9 4 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0360-1323 EI 1873-684X J9 BUILD ENVIRON JI Build. Environ. PD JAN PY 2014 VL 71 BP 131 EP 139 DI 10.1016/j.buildenv.2013.09.021 PG 9 WC Construction & Building Technology; Engineering, Environmental; Engineering, Civil SC Construction & Building Technology; Engineering GA 275XP UT WOS:000328713000013 ER PT J AU Liu, J Strachan, DM Thallapally, PK AF Liu, Jian Strachan, Denis M. Thallapally, Praveen K. TI Enhanced noble gas adsorption in Ag@MOF-74Ni SO CHEMICAL COMMUNICATIONS LA English DT Article ID METAL-ORGANIC FRAMEWORKS; HYDROGEN STORAGE; ROOM-TEMPERATURE; CAPTURE; XENON; NANOPARTICLES; SIMULATIONS; SELECTIVITY; METHANE; SURFACE AB Various amounts of Ag nanoparticles were successfully deposited in porous MOF-74Ni (or Ni/DOBDC) by an auto-reduction method. An optimized silver-loaded MOF-74Ni was shown to have an improved Xe adsorption capacity (15% more) at STP compared to the MOF without silver nanoparticles. The silver-loaded sample also has a higher Xe/Kr selectivity. These results are explained by the stronger interactions between polarizable Xe molecules and the well-dispersed Ag nanoparticles. C1 [Liu, Jian; Strachan, Denis M.; Thallapally, Praveen K.] Pacific NW Natl Lab, Fundamental & Computat Directorate, Richland, WA 99352 USA. RP Thallapally, PK (reprint author), Pacific NW Natl Lab, Fundamental & Computat Directorate, Richland, WA 99352 USA. EM Praveen.Thallapally@pnnl.gov RI thallapally, praveen/I-5026-2014; Liu, Jian/C-4707-2011; Liu, Jian/D-3393-2009 OI thallapally, praveen/0000-0001-7814-4467; Liu, Jian/0000-0001-5329-7408; Liu, Jian/0000-0001-5329-7408 FU U.S. Department of Energy (DOE), Office of Nuclear Energy; U.S. Department of Energy by Battelle Memorial Institute [DE-AC05-76RL01830] FX The authors would like to thank the U.S. Department of Energy (DOE), Office of Nuclear Energy for their support, in particular, Jim Bresee who has direct project oversight responsibilities. The authors would also like to thank Terry Todd (Idaho National Laboratory) and Bob Jubin (Oak Ridge National Laboratory) for their continued programmatic support and guidance. We thank the Environmental Molecular Sciences Laboratory (EMSL) for characterization. Pacific Northwest National Laboratory is a multiprogram national laboratory operated for the U.S. Department of Energy by Battelle Memorial Institute under Contract DE-AC05-76RL01830. NR 41 TC 43 Z9 44 U1 17 U2 141 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1359-7345 EI 1364-548X J9 CHEM COMMUN JI Chem. Commun. PY 2014 VL 50 IS 4 BP 466 EP 468 DI 10.1039/c3cc47777k PG 3 WC Chemistry, Multidisciplinary SC Chemistry GA 277JE UT WOS:000328814000024 PM 24256738 ER PT J AU Kim, TJ Kwon, G Kim, YT AF Kim, Tae-Jun Kwon, Gihan Kim, Yong-Tae TI Anomalously increased oxygen reduction reaction activity with accelerated durability test cycles for platinum on thiolated carbon nanotubes SO CHEMICAL COMMUNICATIONS LA English DT Article ID FUEL-CELLS; HIGH DISPERSION; PARTICLE-SIZE; NANOPARTICLES; ELECTROCATALYSTS; SUPPORT AB We report an anomalous phenomenon in Pt supported on thiolated multi-walled carbon nanotubes (Pt-S-MWNT): oxygen reduction reaction (ORR) activity increases with accelerated durability test (ADT) cycles. Sub-nanometer-sized Pt clusters on S-MWNT were gradually agglomerated to an optimal size with ADT cycles, and finally showed increased ORR activity after the ADT. C1 [Kim, Tae-Jun; Kim, Yong-Tae] Pusan Natl Univ, Dept Energy Syst, Pusan 609735, South Korea. [Kwon, Gihan] Argonne Natl Lab, Div Chem Sci & Engn, Argonne, IL 60439 USA. RP Kim, YT (reprint author), Pusan Natl Univ, Dept Energy Syst, Pusan 609735, South Korea. EM yongtae@pusan.ac.kr FU National Research Foundation of Korea (NRF) [NRF-2012R1A1A2007624, NRF-2012K2A1A2032856]; Korea CCS RD Center (KCRC) [2013M1A8A1040703]; Government of Korea; GCRC-SOP grant FX This work was supported by the National Research Foundation of Korea (NRF) grants (NRF-2012R1A1A2007624 and NRF-2012K2A1A2032856), the Korea CCS R&D Center (KCRC) grant (2013M1A8A1040703), and the GCRC-SOP grant funded by the Government of Korea. NR 22 TC 5 Z9 5 U1 2 U2 24 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1359-7345 EI 1364-548X J9 CHEM COMMUN JI Chem. Commun. PY 2014 VL 50 IS 5 BP 596 EP 598 DI 10.1039/c3cc46036c PG 3 WC Chemistry, Multidisciplinary SC Chemistry GA 275BJ UT WOS:000328650000029 PM 24275723 ER PT J AU Matsubara, Y Hightower, SE Chen, JZ Grills, DC Polyansky, DE Muckerman, JT Tanaka, K Fujita, E AF Matsubara, Yasuo Hightower, Sean E. Chen, Jinzhu Grills, David C. Polyansky, Dmitry E. Muckerman, James T. Tanaka, Koji Fujita, Etsuko TI Reactivity of a fac-ReCl(alpha-diimine)(CO)(3) complex with an NAD(+) model ligand toward CO2 reduction SO CHEMICAL COMMUNICATIONS LA English DT Article ID HYDRIDE DONOR; ELECTROCHEMICAL REDUCTION; CARBON-DIOXIDE; HYDROGEN-ATOM; PROTON; HYDRICITIES; RHENIUM(I); ACTIVATION; GENERATION; ABILITIES AB The reactivity of a rhenium complex containing an NAD(+) model ligand was examined toward photochemical formation of the corresponding NADH-like dihydro form of the complex and electrochemical CO2 reduction. The hydricity of the NADH-like complex was estimated by a thermodynamic cycle and reaction with Ph3C+. C1 [Matsubara, Yasuo; Hightower, Sean E.; Chen, Jinzhu; Grills, David C.; Polyansky, Dmitry E.; Muckerman, James T.; Fujita, Etsuko] Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. [Matsubara, Yasuo] PRESTO, Japan Sci & Technol, Kawaguchi, Saitama 3320012, Japan. [Tanaka, Koji] Kyoto Univ, Inst Integrated Cell Mat Sci, Adv Chem Technol Ctr Kyoto ACT Kyoto, Fushimi Ku, Kyoto 6128374, Japan. RP Matsubara, Y (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM fujita@bnl.gov RI Polyansky, Dmitry/C-1993-2009; Grills, David/F-7196-2016 OI Polyansky, Dmitry/0000-0002-0824-2296; Grills, David/0000-0001-8349-9158 FU U.S. Department of Energy [DE-AC02-98CH10886]; Division of Chemical Sciences, Geosciences, & Biosciences, Office of Basic Energy Sciences FX The work at Brookhaven National Laboratory was carried out under contract DE-AC02-98CH10886 with the U.S. Department of Energy and supported by its Division of Chemical Sciences, Geosciences, & Biosciences, Office of Basic Energy Sciences. NR 28 TC 11 Z9 12 U1 3 U2 51 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1359-7345 EI 1364-548X J9 CHEM COMMUN JI Chem. Commun. PY 2014 VL 50 IS 6 BP 728 EP 730 DI 10.1039/c3cc47699e PG 3 WC Chemistry, Multidisciplinary SC Chemistry GA 275BW UT WOS:000328651500029 PM 24287872 ER PT J AU Deng, WJ Fu, GY AF Deng, Wenjun Fu, Guo-Yong TI Optimization by marker removal for delta f particle simulations SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE Particle simulation; Particle-in-cell; Marker particle; Particle distribution; Optimization; Arbitrary dimension ID PLASMAS; CODE AB A marker removal optimization technique is developed for delta f particle simulations. The technique uses the linear eigenmode structure in the equilibrium constant-of-motion space to construct an importance function, then removes some markers based on the importance function and adjusts the weights of the leftover markers to optimize the marker distribution function, so as to save markers and computing time. The technique can be directly applied to single-mode linear simulations. For multi-mode or nonlinear simulations, the technique can still be directly applied if there is one most unstable mode that dominates the simulation and delta f does not change too much in the nonlinear stage, otherwise special care is needed, which is discussed in detail in this paper. The technique's effectiveness, e.g., marker saving factor, depends on how localized delta f is. The technique can be used for a phase space of arbitrary dimension, as long as the constants of motion in equilibrium can be found. In this paper, the technique is tested in a 2D bump-on-tail simulation and a 5D gyrokinetic toroidal Alfven eigenmode (TAE) simulation and saves markers by factors of 4 and 19, respectively. The technique is not limited to particle-in-cell (PIC) simulations but could be applied to other approaches of marker particle simulations such as particle-in-wavelet (PIW) and grid-free treecode simulations. (C) 2013 Elsevier B.V. All rights reserved. C1 [Deng, Wenjun; Fu, Guo-Yong] Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Deng, WJ (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. EM wdeng@wdeng.info; fu@pppl.gov FU US DOE SciDAC Center for Nonlinear Simulation of Energetic Particles in Burning Plasmas (CSEP) FX This manuscript has been authored by Princeton University under Contract Number DE-AC02-09CH11466 with the US Department of Energy (DOE). The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. This work has also been supported by the US DOE SciDAC Center for Nonlinear Simulation of Energetic Particles in Burning Plasmas (CSEP). Simulations have been performed using the Hopper supercomputer at NERSC. The authors acknowledge useful discussions with C.S. Chang, W.W. Lee, P. Porazik and B. Wang. NR 39 TC 2 Z9 2 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 EI 1879-2944 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD JAN PY 2014 VL 185 IS 1 BP 96 EP 105 DI 10.1016/j.cpc.2013.08.019 PG 10 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 275HE UT WOS:000328666100011 ER PT J AU Squire, J Burby, J Qin, H AF Squire, J. Burby, J. Qin, H. TI VEST: Abstract vector calculus simplification in Mathematica SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE Vector calculus; Computer algebra; Tensors; Mathematica ID GUIDING-CENTER MOTION; COMPUTER ALGEBRA; SYMBOLIC VECTOR; IDENTITIES AB We present a new package, VEST (Vector Einstein Summation Tools), that performs abstract vector calculus computations in Mathematica. Through the use of index notation, VEST is able to reduce three-dimensional scalar and vector expressions of a very general type to a well defined standard form. In addition, utilizing properties of the Levi-Civita symbol, the program can derive types of multi-term vector identities that are not recognized by reduction, subsequently applying these to simplify large expressions. In a companion paper Burby et al. (2013) [12], we employ VEST in the automation of the calculation of high-order Lagrangians for the single particle guiding center system in plasma physics, a computation which illustrates its ability to handle very large expressions. VEST has been designed to be simple and intuitive to use, both for basic checking of work and more involved computations. Program summary Program title: VEST (Vector Einstein Summation Tools) Catalogue identifier: AEQN_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEQN_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 10469 No. of bytes in distributed program, including test data, etc.: 72539 Distribution format: tar.gz Programming language: Mathematica. Computer: Any computer running Mathematica. Operating system: Linux, Unix, Windows, Mac OS X. RAM: Usually under 10 Mbytes Classification: 5, 12, 19. Nature of problem: Large scale vector calculus computations Solution method: Reduce expressions to standard form in index notation, automatic derivation of multi-term vector identities. Restrictions: Current version cannot derive vector identities without cross products or curl Additional comments: Intuitive user input and output in a combination of vector and index notation Running time: Reduction to standard form is usually less than one second. Simplification of very large expressions can take much longer. (C) 2013 Elsevier B.V. All rights reserved. C1 [Squire, J.; Burby, J.; Qin, H.] Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. [Qin, H.] Univ Sci & Technol China, Dept Modern Phys, Hefei 230026, Anhui, Peoples R China. RP Squire, J (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. EM jsquire@princeton.edu FU US DOE [DE-AC02-09CH11466] FX This research is supported by US DOE (DE-AC02-09CH11466). NR 28 TC 3 Z9 3 U1 2 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 EI 1879-2944 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD JAN PY 2014 VL 185 IS 1 BP 128 EP 135 DI 10.1016/j.cpc.2013.08.021 PG 8 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 275HE UT WOS:000328666100013 ER PT J AU Howlett, SE Castillo, HS Gioeni, LJ Robertson, JM Donfack, J AF Howlett, Susanne E. Castillo, Hilda S. Gioeni, Lora J. Robertson, James M. Donfack, Joseph TI Evaluation of DNAstable (TM) for DNA storage at ambient temperature SO FORENSIC SCIENCE INTERNATIONAL-GENETICS LA English DT Article DE Forensic science; Long-term DNA storage; DNAstable (TM); Room-temperature storage; qPCR; STRs ID FORENSIC SAMPLES; PCR ASSAY; DEGRADATION; ANHYDROBIOSIS; RADIATION; STABILITY; ACID AB Preserving DNA is important for validation of prospective and retrospective analyses, requiring many expensive types of equipment (e. g., freezers and back-up generators) and energy. While freezing is the most common method for storing extracted DNA evidence or well-characterized DNA samples for validation studies, DNAstable (TM) (Biomatrica (R)), a commercially available medium for room temperature storage of DNA extracts was evaluated in this study. Two groups of samples consisting of different DNA quantities were investigated, one ranging from 20 to 400 ng (group 1) and the other one ranging from 1.4 to 20 ng (group 2). The DNA samples with and without DNAstable (TM) were stored at four different temperatures [similar to 25 degrees C (room temperature), -20 degrees C, 37 degrees C or 50 degrees C(. DNA degradation over several months was monitored by SYBR (R) Green-based qPCR assays and by PCR amplification of the core CODIS STR markers for group 1 and 2 DNA samples, respectively. For the time points tested in this study (up to 365 days), the findings indicate that the -20 degrees C controls and the DNAstable (TM) protected samples at room temperature provided similar DNA recoveries that were higher compared to the unprotected controls kept at RT, 37 degrees C or 50 degrees C. These results suggest that DNAstable (TM) can protect DNA samples with effectiveness similar to that of the traditional -20 degrees C freezing method. In addition, extrapolations from accelerated aging experiments conducted at high temperatures support that DNAstable (TM) is an effective technology for preserving purified DNA at room temperature with a larger protective impact on DNA samples of low quantity ( <20 ng). (C) 2013 Elsevier Ireland Ltd. All rights reserved. C1 [Howlett, Susanne E.; Castillo, Hilda S.; Robertson, James M.; Donfack, Joseph] FBI Lab Div, Counterterrorism & Forens Sci Res Unit, Quantico, VA 22135 USA. [Gioeni, Lora J.] FBI Lab Div, Chem Biol Radiol Nucl Sci Unit, Quantico, VA 22135 USA. [Howlett, Susanne E.; Castillo, Hilda S.] Oak Ridge Inst Sci & Educ, Oak Ridge, TN USA. RP Donfack, J (reprint author), FBI Lab Div, Counterterrorism & Forens Sci Res Unit, 2501 Invest Pkwy, Quantico, VA 22135 USA. EM Joseph.Donfack@ic.fbi.gov FU Federal Bureau of Investigation (FBI) Laboratory Division; FBI's Visiting Scientist Program FX This research was supported by the Federal Bureau of Investigation (FBI) Laboratory Division. Susanne Howlett and Hilda Castillo were supported by the FBI's Visiting Scientist Program, an educational opportunity administered by the Oak Ridge Institute for Science and Education (ORISE). The authors would like to thank Eugene M. Peters, Mark F. Kavlick and Barbara W. Koons for their comments. Names of commercial manufacturers are provided for identification purposes only, and inclusion does not imply endorsement of the manufacturer, its products, or services by the FBI. The views expressed are those of the authors' and do not necessarily reflect the official policy or position of the FBI or the United States Government. This publication is number 12-19 of the Counterterrorism and Forensic Science Research Unit (CFSRU), FBI Laboratory Division. NR 38 TC 7 Z9 8 U1 0 U2 16 PU ELSEVIER IRELAND LTD PI CLARE PA ELSEVIER HOUSE, BROOKVALE PLAZA, EAST PARK SHANNON, CO, CLARE, 00000, IRELAND SN 1872-4973 EI 1878-0326 J9 FORENSIC SCI INT-GEN JI Forensic Sci. Int.-Genet. PD JAN PY 2014 VL 8 IS 1 BP 170 EP 178 DI 10.1016/j.fsigen.2013.09.003 PG 9 WC Genetics & Heredity; Medicine, Legal SC Genetics & Heredity; Legal Medicine GA 272TE UT WOS:000328483000024 PM 24315605 ER PT J AU Bond-Lamberty, B Rocha, AV Calvin, K Holmes, B Wang, CK Goulden, ML AF Bond-Lamberty, Ben Rocha, Adrian V. Calvin, Katherine Holmes, Bruce Wang, Chuankuan Goulden, Michael L. TI Disturbance legacies and climate jointly drive tree growth and mortality in an intensively studied boreal forest SO GLOBAL CHANGE BIOLOGY LA English DT Article DE boreal forest; carbon cycling; climate change; dendrology; disturbance; forest mortality; machine learning ID BLACK SPRUCE CHRONOSEQUENCE; NET PRIMARY PRODUCTION; COARSE WOODY DEBRIS; INTERANNUAL VARIABILITY; GLOBAL CONVERGENCE; CARBON STORAGE; CANADA FORESTS; CO2 EXCHANGE; FIRE; DROUGHT AB Most North American forests are at some stage of post-disturbance regrowth, subject to a changing climate, and exhibit growth and mortality patterns that may not be closely coupled to annual environmental conditions. Distinguishing the possibly interacting effects of these processes is necessary to put short-term studies in a longer term context, and particularly important for the carbon-dense, fire-prone boreal forest. The goals of this study were to combine dendrochronological sampling, inventory records, and machine-learning algorithms to understand how tree growth and death have changed at one highly studied site (Northern Old Black Spruce, NOBS) in the central Canadian boreal forest. Over the 1999-2012 inventory period, mean tree diameter increased even as stand density and basal area declined significantly. Tree mortality averaged 1.4 +/- 0.6%yr(-1), with most mortality occurring in medium-sized trees; new recruitment was minimal. There have been at least two, and probably three, significant influxes of new trees since stand initiation, but none in recent decades. A combined tree ring chronology constructed from sampling in 2001, 2004, and 2012 showed several periods of extreme growth depression, with increased mortality lagging depressed growth by similar to 5years. Higher minimum and maximum air temperatures exerted a negative influence on tree growth, while precipitation and climate moisture index had a positive effect; both current- and previous-year data exerted significant effects. Models based on these variables explained 23-44% of the ring-width variability. We suggest that past climate extremes led to significant mortality still visible in the current forest structure, with decadal dynamics superimposed on slower patterns of fire and succession. These results have significant implications for our understanding of previous work at NOBS, the carbon sequestration capability of old-growth stands in a disturbance-prone landscape, and the sustainable management of regional forests in a changing climate. C1 [Bond-Lamberty, Ben; Calvin, Katherine] Univ Maryland, Joint Global Change Res Inst, Pacific NW Natl Lab, College Pk, MD 20740 USA. [Rocha, Adrian V.] Univ Notre Dame, Galvin Life Sci Ctr 100, Dept Biol Sci, Notre Dame, IN 46556 USA. [Rocha, Adrian V.] Univ Notre Dame, Galvin Life Sci Ctr 100, Environm Change Initiat, Notre Dame, IN 46556 USA. [Holmes, Bruce] Manitoba Conservat, Thompson, MB R8N 1X4, Canada. [Wang, Chuankuan] Northeast Forestry Univ, Ctr Ecol Res, Harbin 150040, Peoples R China. [Goulden, Michael L.] Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92697 USA. RP Bond-Lamberty, B (reprint author), Univ Maryland, Joint Global Change Res Inst, Pacific NW Natl Lab, 5825 Univ Res Court, College Pk, MD 20740 USA. EM bondlamberty@pnnl.gov RI Bond-Lamberty, Ben/C-6058-2008; Goulden, Michael/B-9934-2008; OI Bond-Lamberty, Ben/0000-0001-9525-4633; Calvin, Katherine/0000-0003-2191-4189 FU Terrestrial Ecosystem Science program at the US Department of Energy; National Science Foundation (Integrated Research Challenges in Environmental Biology) [DEB-0077881] FX This study was funded by the Terrestrial Ecosystem Science program at the US Department of Energy. The 1999-2004 data collection efforts were funded by the National Science Foundation (Integrated Research Challenges in Environmental Biology, DEB-0077881). NR 98 TC 23 Z9 25 U1 6 U2 105 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1354-1013 EI 1365-2486 J9 GLOBAL CHANGE BIOL JI Glob. Change Biol. PD JAN PY 2014 VL 20 IS 1 BP 216 EP 227 DI 10.1111/gcb.12404 PG 12 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 266BZ UT WOS:000327998600020 PM 24115380 ER PT J AU Rotman, Y Noureddin, M Feld, JJ Guedj, J Witthaus, M Han, H Park, YJ Park, SH Heller, T Ghany, MG Doo, E Koh, C Abdalla, A Gara, N Sarkar, S Thomas, E Ahlenstiel, G Edlich, B Titerence, R Hogdal, L Rehermann, B Dahari, H Perelson, AS Hoofnagle, JH Liang, TJ AF Rotman, Yaron Noureddin, Mazen Feld, Jordan J. Guedj, Jeremie Witthaus, Michael Han, Hwalih Park, Yoon J. Park, Su-Hyung Heller, Theo Ghany, Marc G. Doo, Edward Koh, Christopher Abdalla, Adil Gara, Naveen Sarkar, Souvik Thomas, Emmanuel Ahlenstiel, Golo Edlich, Birgit Titerence, Rachel Hogdal, Leah Rehermann, Barbara Dahari, Harel Perelson, Alan S. Hoofnagle, Jay H. Liang, T. Jake TI Effect of ribavirin on viral kinetics and liver gene expression in chronic hepatitis C SO GUT LA English DT Article DE Hepatitis C; Interferon-Alpha ID PEGYLATED INTERFERON; COMBINATION THERAPY; VIRUS-INFECTION; PLUS RIBAVIRIN; ALPHA; NONRESPONDERS; PEGINTERFERON; RESPONDERS; INDUCTION; MECHANISM AB Objective Ribavirin improves treatment response to pegylated-interferon (PEG-IFN) in chronic hepatitis C but the mechanism remains controversial. We studied correlates of response and mechanism of action of ribavirin in treatment of hepatitis C. Design 70 treatment-naive patients were randomised to 4weeks of ribavirin (1000-1200mg/d) or none, followed by PEG-IFN-2a and ribavirin at standard doses and durations. Patients were also randomised to a liver biopsy 24h before or 6h after starting PEG-IFN. Hepatic gene expression was assessed by microarray and interferon-stimulated gene (ISG) expression quantified by nCounter platform. Temporal changes in ISG expression were assessed by qPCR in peripheral-blood mononuclear cells (PBMC) and by serum levels of IP-10. Results After 4weeks of ribavirin monotherapy, hepatitis C virus (HCV) levels decreased by 0.50.5 log(10) (p=0.009 vs controls) and ALT by 33% (p<0.001). Ribavirin pretreatment, while modestly augmenting ISG induction by PEG-IFN, did not modify the virological response to subsequent PEG-IFN and ribavirin treatment. However, biochemical, but not virological, response to ribavirin monotherapy predicted response to subsequent combination treatment (rapid virological response, 71% in biochemical responders vs 22% non-responders, p=0.01; early virological response, 100% vs 68%, p=0.03; sustained virological response 83% vs 41%, p=0.053). Ribavirin monotherapy lowered serum IP-10 levels but had no effect on ISG expression in PBMC. Conclusions Ribavirin is a weak antiviral but its clinical effect seems to be mediated by a separate, indirect mechanism, which may act to reset IFN-responsiveness in HCV-infected liver. C1 [Rotman, Yaron; Noureddin, Mazen; Feld, Jordan J.; Witthaus, Michael; Han, Hwalih; Park, Yoon J.; Park, Su-Hyung; Heller, Theo; Ghany, Marc G.; Koh, Christopher; Abdalla, Adil; Gara, Naveen; Sarkar, Souvik; Thomas, Emmanuel; Ahlenstiel, Golo; Edlich, Birgit; Titerence, Rachel; Hogdal, Leah; Rehermann, Barbara; Hoofnagle, Jay H.; Liang, T. Jake] NIDDK, Liver Dis Branch, NIH, Bethesda, MD 20892 USA. [Guedj, Jeremie; Dahari, Harel; Perelson, Alan S.] Los Alamos Natl Lab, Theoret Biol & Biophys Grp, Los Alamos, NM USA. [Guedj, Jeremie] INSERM, UMR 738, F-75018 Paris, France. [Guedj, Jeremie] Univ Paris Diderot, Sorbonne Paris Cite, UMR 738, F-75018 Paris, France. [Doo, Edward] NIDDK, Liver Dis Res Branch, NIH, Bethesda, MD 20892 USA. [Dahari, Harel] Univ Illinois, Dept Med, Chicago, IL USA. [Dahari, Harel] Loyola Univ Chicago, Dept Med, Div Hepatol, Maywood, IL USA. RP Rotman, Y (reprint author), NIDDK, NIH, Liver Dis Branch, 10 Ctr Dr,Bldg 10,Room 9C434,MSC1800, Bethesda, MD 20892 USA. EM rotmany@mail.nih.gov RI Guedj, Jeremie/A-6842-2017; Park, Su-Hyung/N-3514-2014 OI Guedj, Jeremie/0000-0002-5534-5482; Rotman, Yaron/0000-0002-7549-8216; Sarkar, Souvik/0000-0002-9358-4257; Ahlenstiel, Golo/0000-0003-0026-1457; FU NIDDK; NIH [R01-OD011095, R37-AI028433, R01-AI078881, R34-HL109334, P20-GM103452]; University of Illinois Walter Payton Liver Center GUILD FX The study was supported by the intramural research program of NIDDK; NIH grants R01-OD011095, R37-AI028433, R01-AI078881, R34-HL109334 and P20-GM103452; and the University of Illinois Walter Payton Liver Center GUILD. NR 27 TC 24 Z9 25 U1 1 U2 14 PU BMJ PUBLISHING GROUP PI LONDON PA BRITISH MED ASSOC HOUSE, TAVISTOCK SQUARE, LONDON WC1H 9JR, ENGLAND SN 0017-5749 EI 1468-3288 J9 GUT JI Gut PD JAN PY 2014 VL 63 IS 1 BP 161 EP 169 DI 10.1136/gutjnl-2012-303852 PG 9 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA 263VB UT WOS:000327835000019 PM 23396509 ER PT J AU Trushina, E Canaria, CA Lee, DY McMurray, CT AF Trushina, Eugenia Canaria, Christie A. Lee, Do-Yup McMurray, Cynthia T. TI Loss of caveolin-1 expression in knock-in mouse model of Huntington's disease suppresses pathophysiology in vivo SO HUMAN MOLECULAR GENETICS LA English DT Article ID CHOLESTEROL-BIOSYNTHESIS PATHWAY; NEUROLOGICAL ABNORMALITIES; ENDOPLASMIC-RETICULUM; PLASMA-MEMBRANE; CELL-SURFACE; LDL RECEPTOR; PROTEIN; MICE; METABOLISM; TRAFFICKING AB Loss of cholesterol homeostasis and altered vesicle trafficking have been detected in Huntington's disease (HD) cellular and animal models, yet the role of these dysfunctions in pathophysiology of HD is unknown. We demonstrate here that defects in caveolar-related cholesterol trafficking directly contribute to the mechanism of HD in vivo. We generated new mouse models that express mutant Huntington's protein (mhtt), but have partial or total loss of caveolin-1 (Cav1) expression. Fluorescence resonance energy transfer dequenching confirms a direct interaction between mhtt and Cav1. Mhtt-expressing neurons exhibited cholesterol accumulation and suppressed caveolar-related post-Golgi trafficking from endoplasmic reticulum/Golgi to plasma membrane. Loss or reduction of Cav1 expression in a knock-in HD mouse model rescues the cholesterol phenotype in neurons and significantly delays the onset of motor decline and development of neuronal inclusions. We propose that aberrant interaction between Cav1 and mhtt leads to altered cholesterol homeostasis and plays a direct causative role in the onset of HD pathophysiology in vivo. C1 [Trushina, Eugenia] Mayo Clin, Dept Neurol, Rochester, MN 55905 USA. [Trushina, Eugenia] Mayo Clin, Dept Pharmacol & Expt Therapeut, Rochester, MN 55905 USA. [Canaria, Christie A.; McMurray, Cynthia T.] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. [Lee, Do-Yup] Kookmin Univ, Dept Adv Fermentat Fus Sci & Technol, Seoul, South Korea. RP McMurray, CT (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, 1 Cyclotron Rd,Bldg 83, Berkeley, CA 94720 USA. EM ctmcmurray@lbl.gov RI di Ronza, Alberto/H-7674-2016 OI di Ronza, Alberto/0000-0002-9813-5143 FU Mayo Foundation; National Institutes of Health [NS40738, NS062384, NS069177, ES020766, R01ES020715] FX This work was supported by the Mayo Foundation and the National Institutes of Health (NS40738, NS062384, NS069177 and ES020766 to C. T. M. and R01ES020715 to E. T.). We thank Ramandeep Takhter for help with TLC experiments. NR 60 TC 9 Z9 9 U1 0 U2 7 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0964-6906 EI 1460-2083 J9 HUM MOL GENET JI Hum. Mol. Genet. PD JAN 1 PY 2014 VL 23 IS 1 BP 129 EP 144 DI 10.1093/hmg/ddt406 PG 16 WC Biochemistry & Molecular Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Genetics & Heredity GA 272SZ UT WOS:000328482300011 PM 24021477 ER PT J AU Luffel, M Gurung, T Lindstrom, P Rossignac, J AF Luffel, Mark Gurung, Topraj Lindstrom, Peter Rossignac, Jarek TI Grouper: A Compact, Streamable Triangle Mesh Data Structure SO IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS LA English DT Article DE Mesh compression; mesh data structures; random access; out-of-core algorithms; large meshes ID POLYGONAL MODELS; SIMPLIFICATION; COMPRESSION; VISUALIZATION; COMPUTATION; ALGORITHM AB We present Grouper: an all-in-one compact file format, random-access data structure, and streamable representation for large triangle meshes. Similarly to the recently published SQuad representation, Grouper represents the geometry and connectivity of a mesh by grouping vertices and triangles into fixed-size records, most of which store two adjacent triangles and a shared vertex. Unlike SQuad, however, Grouper interleaves geometry with connectivity and uses a new connectivity representation to ensure that vertices and triangles can be stored in a coherent order that enables memory-efficient sequential stream processing. We present a linear-time construction algorithm that allows streaming out Grouper meshes using a small memory footprint while preserving the initial ordering of vertices. As a part of this construction, we show how the problem of assigning vertices and triangles to groups reduces to a well-known NP-hard optimization problem, and present a simple yet effective heuristic solution that performs well in practice. Our array-based Grouper representation also doubles as a triangle mesh data structure that allows direct access to vertices and triangles. Storing only about two integer references per triangle-i.e., less than the three vertex references stored with each triangle in a conventional indexed mesh format-Grouper answers both incidence and adjacency queries in amortized constant time. Our compact representation enables data-parallel processing on multicore computers, instant partitioning and fast transmission for distributed processing, as well as efficient out-of-core access. We demonstrate the versatility and performance benefits of Grouper using a suite of example meshes and processing kernels. C1 [Luffel, Mark; Gurung, Topraj; Rossignac, Jarek] Georgia Inst Technol, Graph Visualizat & Usabil Ctr GVU, Atlanta, GA 30308 USA. [Lindstrom, Peter] Lawrence Livermore Natl Lab, CASC, Livermore, CA 94551 USA. RP Luffel, M (reprint author), Georgia Inst Technol, Graph Visualizat & Usabil Ctr GVU, Atlanta, GA 30308 USA. EM mluffel@cc.gatech.edu; topraj@cc.gatech.edu; pl@llnl.gov; jarek@cc.gatech.edu OI Lindstrom, Peter/0000-0003-3817-4199 FU US Department of Energy by Lawrence Livermore National Laboratory [DE-AC52-07NA27344] FX This work was performed in part under the auspices of the US Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. NR 37 TC 1 Z9 2 U1 1 U2 7 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1077-2626 EI 1941-0506 J9 IEEE T VIS COMPUT GR JI IEEE Trans. Vis. Comput. Graph. PD JAN PY 2014 VL 20 IS 1 BP 84 EP 98 DI 10.1109/TVCG.2013.81 PG 15 WC Computer Science, Software Engineering SC Computer Science GA 265OF UT WOS:000327960700009 PM 24201328 ER PT J AU Li, DS Zbib, H Sun, X Khaleel, M AF Li, Dongsheng Zbib, Hussein Sun, Xin Khaleel, Mohammad TI Predicting plastic flow and irradiation hardening of iron single crystal with mechanism-based continuum dislocation dynamics SO INTERNATIONAL JOURNAL OF PLASTICITY LA English DT Article DE Dislocations; Constitutive behavior; Elastic-viscoplastic material; Continuum dislocation dynamics ID CROSS-SLIP; LOCALIZED DEFORMATION; METAL CRYSTALS; FCC CRYSTALS; SIMULATIONS; DENSITY; SYSTEMS; CREEP; MODEL; POLYCRYSTALS AB Continuum dislocation dynamics (CDD) with a novel constitutive law based on dislocation density evolution mechanisms was developed to investigate the deformation behaviors of single crystals. The dislocation density evolution law in this model is mechanism-based, with parameters predicted by lower-length scale models or measured from experiments, not an empirical law with parameters back-fitted from the flow curves. Applied on iron single crystal, this model was validated by experimental data and compared with traditional single crystal constitutive models using a Hutchinson-type hardening law or a dislocation-based hardening law. The CDD model demonstrated higher fidelity than other constitutive models when anisotropic single crystal deformation behaviors were investigated. The traditional Hutchinson type hardening laws and other constitutive laws based on a Kocks formulated dislocation density evolution law will only succeed in a limited number of loading directions. The main advantage of COD is the novel physics-based dislocation density evolution laws in describing the meso-scale microstructure evolution. Another advantage of CDD is on cross-slip, which is very important when loading conditions activate only one primary slip system. In addition to the dislocation hardening, CDD also takes into consideration dislocation defect interactions. Irradiation hardening of iron single crystal was simulated with validation from experimental results. Published by Elsevier Ltd. C1 [Li, Dongsheng; Zbib, Hussein; Sun, Xin; Khaleel, Mohammad] Pacific NW Natl Lab, Fundamental & Computat Sci Directorate, Richland, WA 99352 USA. [Zbib, Hussein] Washington State Univ, Sch Mech & Mat Engn, Pullman, WA 99164 USA. RP Li, DS (reprint author), Pacific NW Natl Lab, Fundamental & Computat Sci Directorate, Richland, WA 99352 USA. EM dongsheng.li@pnnl.gov OI khaleel, mohammad/0000-0001-7048-0749 FU DOE's Nuclear Energy Advanced Modeling and Simulation (NEAMS) program at Pacific Northwest National Laboratory (PNNL); Battelle for the DOE [DE-AC05-76RL01830] FX This work was funded by DOE's Nuclear Energy Advanced Modeling and Simulation (NEAMS) program at Pacific Northwest National Laboratory (PNNL). PNNL is operated by Battelle for the DOE under contract No. DE-AC05-76RL01830. NR 67 TC 28 Z9 28 U1 4 U2 35 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0749-6419 EI 1879-2154 J9 INT J PLASTICITY JI Int. J. Plast. PD JAN PY 2014 VL 52 SI SI BP 3 EP 17 DI 10.1016/j.ijplas.2013.01.015 PG 15 WC Engineering, Mechanical; Materials Science, Multidisciplinary; Mechanics SC Engineering; Materials Science; Mechanics GA 275YK UT WOS:000328715100002 ER PT J AU Alankar, A Field, DP Raabe, D AF Alankar, Alankar Field, David P. Raabe, Dierk TI Plastic anisotropy of electro-deposited pure alpha-iron with sharp crystallographic < 1 1 1 >// texture in normal direction: Analysis by an explicitly dislocation-based crystal plasticity model SO INTERNATIONAL JOURNAL OF PLASTICITY LA English DT Article DE Crystallographic texture; alpha-Iron; Dislocations; Kink-pairs; Metal sheet forming ID CENTERED-CUBIC METALS; BCC SINGLE-CRYSTALS; ROLLING TEXTURES; PRISMATIC SLIP; POLYCRYSTAL PLASTICITY; CONSTITUTIVE MODEL; PEIERLS MECHANISM; GRAIN-BOUNDARIES; DEFORMATION; SIMULATIONS AB We present a single crystal plasticity model based on edge and screw dislocation densities for body centered cubic (bcc) crystals. In a bcc crystal screw dislocations experience high lattice friction due to their non-planar core. Hence, they have much slower velocity compared to edge dislocations. This phenomenon is modeled by accounting for the motion of screw dislocations via nucleation and expansion of kink-pairs. The model, embedded as a constitutive law into a crystal plasticity framework, is able to predict the crystallographic texture of a bcc polycrystal subjected to 70%, 80% and 90% thickness reduction. We perform a parametric study based on the velocities of edge and screw dislocations to analyze the effect on plastic anisotropy of electro-deposited pure iron with long needle-shaped grains having sharp crystallographic < 111 >//ND texture (ND: normal direction). The model shows a large change in the r-value (Lankford value, planar anisotropy ratio) for pure iron when the texture changes from random to < 111 >//ND. For different simulated cases where the crystallites have an orientation deviation of 1 degrees, 3 degrees and 5 degrees, respectively, from the ideal < 111 >//ND axis, the simulations predict r-values between 4.0 and 7.0 which is in excellent agreement with data observed in experiments by Yoshinaga et al. (ISIJ Intern., 48 (2008) 667-670). For these specific orientations of grains, we also model the effect of long needle shaped grains via a procedure that excludes dislocation annihilation. (C) 2013 Elsevier Ltd. All rights reserved. C1 [Alankar, Alankar] Los Alamos Natl Lab, Mat Sci & Technol Div, Los Alamos, NM 87545 USA. [Alankar, Alankar; Field, David P.] Washington State Univ, Sch Mech & Mat Engn, Pullman, WA 99164 USA. [Alankar, Alankar; Raabe, Dierk] Max Planck Inst Eisenforsch GmbH, Microstruct Phys & Alloy Design, D-40235 Dusseldorf, Germany. RP Alankar, A (reprint author), Los Alamos Natl Lab, Mat Sci & Technol Div, MST-8,MS G755, Los Alamos, NM 87545 USA. EM alankar@lanl.gov RI Field, David/D-5216-2012; Raabe, Dierk/A-6470-2009 OI Field, David/0000-0001-9415-0795; Raabe, Dierk/0000-0003-0194-6124 NR 78 TC 10 Z9 10 U1 3 U2 25 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0749-6419 EI 1879-2154 J9 INT J PLASTICITY JI Int. J. Plast. PD JAN PY 2014 VL 52 SI SI BP 18 EP 32 DI 10.1016/j.ijplas.2013.03.006 PG 15 WC Engineering, Mechanical; Materials Science, Multidisciplinary; Mechanics SC Engineering; Materials Science; Mechanics GA 275YK UT WOS:000328715100003 ER PT J AU Li, DS Ahzi, S M'Guil, S Wen, W Lavender, C Khaleel, MA AF Li, D. S. Ahzi, S. M'Guil, S. Wen, W. Lavender, C. Khaleel, M. A. TI Modeling of deformation behavior and texture evolution in magnesium alloy using the intermediate phi-model SO INTERNATIONAL JOURNAL OF PLASTICITY LA English DT Article DE phi-Model; Magnesium alloy; Crystal plasticity; Texture ID CONSISTENT VISCOPLASTIC MODEL; SELF-CONSISTENT; PLASTIC-DEFORMATION; ZIRCONIUM ALLOYS; MECHANICAL-BEHAVIOR; HEXAGONAL MATERIALS; ROLLING TEXTURES; ROOM-TEMPERATURE; TITANIUM-ALLOYS; AZ31B SHEET AB The viscoplastic intermediate phi-model was applied in this work to predict the deformation behavior and texture evolution in a magnesium alloy, an HCP material. We simulated the deformation behavior with different intergranular interaction strengths and compared the predicted results with available experimental results. In this approach, elasticity is neglected and the plastic deformation mechanisms are assumed as a combination of crystallographic slip and twinning systems. Tests are performed for rolling (plane strain compression) of random textured Mg polycrystal as well as for tensile and compressive tests on rolled Mg sheets. Simulated texture evolutions agree well with experimental data. Activities of twinning and slip, predicted by the intermediate phi-model, reveal the strong anisotropic behavior during tension and compression of rolled sheets. (C) 2013 Elsevier Ltd. All rights reserved. C1 [Li, D. S.; Lavender, C.] Pacific NW Natl Lab, CSMD, Richland, WA 99352 USA. [Ahzi, S.; M'Guil, S.; Wen, W.] Univ Strasbourg, ICube Lab, CNRS, F-67000 Strasbourg, France. [Ahzi, S.] Georgia Inst Technol, Atlanta, GA 30332 USA. [Khaleel, M. A.] Qatar Fdn Res & Dev, Qatar Energy & Environm Res Inst, Doha, Qatar. RP Ahzi, S (reprint author), Univ Strasbourg, ICube Lab, CNRS, 2 Rue Boussingault, F-67000 Strasbourg, France. EM ahzi@unistra.fr OI khaleel, mohammad/0000-0001-7048-0749 FU DOE Office of Energy Efficiency and Renewable Energy; Battelle Memorial Institute for the United States Department of Energy (U.S. DOE) [DE-AC06-76RLO 1830] FX Support for this work was provided by the DOE Office of Energy Efficiency and Renewable Energy. The Pacific Northwest National Laboratory is operated by Battelle Memorial Institute for the United States Department of Energy (U.S. DOE) under Contract DE-AC06-76RLO 1830. NR 71 TC 16 Z9 16 U1 3 U2 18 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0749-6419 EI 1879-2154 J9 INT J PLASTICITY JI Int. J. Plast. PD JAN PY 2014 VL 52 SI SI BP 77 EP 94 DI 10.1016/j.ijplas.2013.06.005 PG 18 WC Engineering, Mechanical; Materials Science, Multidisciplinary; Mechanics SC Engineering; Materials Science; Mechanics GA 275YK UT WOS:000328715100006 ER PT J AU Shao, S Abdolrahim, N Bahr, DF Lin, G Zbib, HM AF Shao, Shuai Abdolrahim, Niaz Bahr, David F. Lin, Guang Zbib, Hussein M. TI Stochastic effects in plasticity in small volumes SO INTERNATIONAL JOURNAL OF PLASTICITY LA English DT Article DE Dislocations; Beams and columns; Metallic material; Probability and statistics; Multiscale ID DISCRETE DISLOCATION DYNAMICS; STRAIN GRADIENT PLASTICITY; THIN COPPER-FILMS; SINGLE-CRYSTALS; MECHANICAL-PROPERTIES; COMPRESSION PILLARS; YIELD STRENGTH; FINITE-ELEMENT; SIZE; DEFORMATION AB Recent studies of micro- and nano-scale metallic structures have exposed considerable statistical distribution, in addition to significant size dependencies, in the yield strength. This intrinsic statistical variation is particularly evident in the micro-compression and microtension thin film tests. This work investigates the relationship between the initial dislocation density, the heterogeneous initial spatial dislocation distribution, and the resulting localized deformation with multiscale discrete dislocation dynamics simulations. This relationship is examined separately from commonly reported external factors affecting observed strength, such as variations in specimen geometry and base support. Towards this end, we performed multiscale dislocation dynamics simulations of geometries commonly employed in micro-scale testing techniques, including micro-pillar compression, microtensile thin film, and microbulge tests. The statistical variation of yield strengths from all three simulation geometries is in agreement with experimental data from the corresponding loading techniques. We show that the onset of plasticity is stochastic in small volumes containing a small density of dislocations: a contrast to classical deterministic plasticity theory. The yield stress in these small volumes is stochastic, not deterministic, because of statistical variation of the initial dislocation content. The numerical results exhibit a localized deformation process and demonstrate a strong dependence of the yield stress on the initial dislocation density, the initial dislocation spatial distribution, and the specimen geometry size. Leveraging nucleation theory, a stochastic model for the onset of plasticity in micro- and nano-scale structures is developed based on these results. (C) 2013 Elsevier Ltd. All rights reserved. C1 [Shao, Shuai; Abdolrahim, Niaz; Zbib, Hussein M.] Washington State Univ, Sch Mech & Mat Engn, Pullman, WA 99164 USA. [Bahr, David F.] Purdue Univ, Sch Mat Engn, W Lafayette, IN 47907 USA. [Lin, Guang] Pacific NW Natl Lab, Computat Sci & Math Div, Richland, WA 99352 USA. RP Zbib, HM (reprint author), Washington State Univ, Sch Mech & Mat Engn, Pullman, WA 99164 USA. EM zbib@wsu.edu RI Shao, Shuai/B-2037-2014; Bahr, David/A-6521-2012; Shao, Shuai/I-4108-2014 OI Shao, Shuai/0000-0002-4718-2783; Bahr, David/0000-0003-2893-967X; Shao, Shuai/0000-0002-4718-2783 FU NSF [CMMI 1030843] FX We gratefully acknowledge the support from NSF to WSU under Grant number CMMI 1030843. NR 67 TC 9 Z9 9 U1 2 U2 32 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0749-6419 EI 1879-2154 J9 INT J PLASTICITY JI Int. J. Plast. PD JAN PY 2014 VL 52 SI SI BP 117 EP 132 DI 10.1016/j.ijplas.2013.09.005 PG 16 WC Engineering, Mechanical; Materials Science, Multidisciplinary; Mechanics SC Engineering; Materials Science; Mechanics GA 275YK UT WOS:000328715100009 ER PT J AU Glass, EM Dribinsky, Y Yilmaz, P Levin, H Van Pelt, R Wendel, D Wilke, A Eisen, JA Huse, S Shipanova, A Sogin, M Stajich, J Knight, R Meyer, F Schriml, LM AF Glass, Elizabeth M. Dribinsky, Yekaterina Yilmaz, Pelin Levin, Hal Van Pelt, Robert Wendel, Doug Wilke, Andreas Eisen, Jonathan A. Huse, Sue Shipanova, Anna Sogin, Mitch Stajich, Jason Knight, Rob Meyer, Folker Schriml, Lynn M. TI MIxS-BE: a MIxS extension defining a minimum information standard for sequence data from the built environment SO ISME JOURNAL LA English DT Editorial Material C1 [Glass, Elizabeth M.; Dribinsky, Yekaterina; Wilke, Andreas; Meyer, Folker] Argonne Natl Lab, Math & Comp Sci Div, Argonne, IL 60439 USA. [Yilmaz, Pelin] Max Planck Inst Marine Microbiol, Bremen, Germany. [Van Pelt, Robert; Wendel, Doug] Univ Colorado, Dept Comp Sci, Boulder, CO 80309 USA. [Eisen, Jonathan A.] Univ Calif Davis, Davis Genome Ctr, Davis, CA 95616 USA. [Huse, Sue; Shipanova, Anna; Sogin, Mitch] Marine Biol Lab, Woods Hole, MA 02543 USA. [Stajich, Jason] Univ Calif Riverside, Riverside, CA USA. [Knight, Rob] Howard Hughes Med Inst, Chevy Chase, MD USA. [Meyer, Folker] Inst Genom & Syst Biol, Argonne Natl Lab, Argonne, IL USA. [Schriml, Lynn M.] Univ Maryland, Sch Med, Inst Genome Sci, Dept Epidemiol & Publ Hlth, Baltimore, MD 21201 USA. RP Glass, EM (reprint author), Argonne Natl Lab, Math & Comp Sci Div, 9700 S Cass Ave, Argonne, IL 60439 USA. EM marland@mcs.anl.gov; marland@mcs.anl.gov RI Stajich, Jason/C-7297-2008; Knight, Rob/D-1299-2010; OI Stajich, Jason/0000-0002-7591-0020; Yilmaz, Pelin/0000-0003-4724-323X; Meyer, Folker/0000-0003-1112-2284; Schriml, Lynn/0000-0001-8910-9851; Eisen, Jonathan A./0000-0002-0159-2197 NR 8 TC 8 Z9 9 U1 1 U2 8 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 1751-7362 EI 1751-7370 J9 ISME J JI ISME J. PD JAN PY 2014 VL 8 IS 1 BP 1 EP 3 DI 10.1038/ismej.2013.176 PG 3 WC Ecology; Microbiology SC Environmental Sciences & Ecology; Microbiology GA 274KM UT WOS:000328605200001 PM 24152717 ER PT J AU Ceja-Navarro, JA Nguyen, NH Karaoz, U Gross, SR Herman, DJ Andersen, GL Bruns, TD Pett-Ridge, J Blackwell, M Brodie, EL AF Ceja-Navarro, Javier A. Nguyen, Nhu H. Karaoz, Ulas Gross, Stephanie R. Herman, Donald J. Andersen, Gary L. Bruns, Thomas D. Pett-Ridge, Jennifer Blackwell, Meredith Brodie, Eoin L. TI Compartmentalized microbial composition, oxygen gradients and nitrogen fixation in the gut of Odontotaenius disjunctus SO ISME JOURNAL LA English DT Article DE symbiosis; microbial diversity; gut microbiome; insect; Passalidae; cellulose ID HIGHER TERMITES; PHYLOGENETIC DIVERSITY; SEQUENCE ALIGNMENT; PASSALID BEETLES; SP-NOV; COMMUNITY; ISOPTERA; PH; INTERFACE; PROFILES AB Coarse woody debris is an important biomass pool in forest ecosystems that numerous groups of insects have evolved to take advantage of. These insects are ecologically important and represent useful natural analogs for biomass to biofuel conversion. Using a range of molecular approaches combined with microelectrode measurements of oxygen, we have characterized the gut microbiome and physiology of Odontotaenius disjunctus, a wood-feeding beetle native to the eastern United States. We hypothesized that morphological and physiological differences among gut regions would correspond to distinct microbial populations and activities. In fact, significantly different communities were found in the foregut (FG), midgut (MG)/posterior hindgut (PHG) and anterior hindgut (AHG), with Actinobacteria and Rhizobiales being more abundant toward the FG and PHG. Conversely, fermentative bacteria such as Bacteroidetes and Clostridia were more abundant in the AHG, and also the sole region where methanogenic Archaea were detected. Although each gut region possessed an anaerobic core, micron-scale profiling identified radial gradients in oxygen concentration in all regions. Nitrogen fixation was confirmed by N-15(2) incorporation, and nitrogenase gene (nifH) expression was greatest in the AHG. Phylogenetic analysis of nifH identified the most abundant transcript as related to Ni-Fe nitrogenase of a Bacteroidetes species, Paludibacter propionicigenes. Overall, we demonstrate not only a compartmentalized microbiome in this beetle digestive tract but also sharp oxygen gradients that may permit aerobic and anaerobic metabolism to occur within the same regions in close proximity. We provide evidence for the microbial fixation of N-2 that is important for this beetle to subsist on woody biomass. C1 [Ceja-Navarro, Javier A.; Karaoz, Ulas; Andersen, Gary L.; Bruns, Thomas D.; Brodie, Eoin L.] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Earth Sci, Dept Ecol, Berkeley, CA 94720 USA. [Nguyen, Nhu H.] Univ Calif Berkeley, Dept Plant & Microbial Sci, Berkeley, CA 94720 USA. [Gross, Stephanie R.; Blackwell, Meredith] Louisiana State Univ, Dept Biol Sci, Baton Rouge, LA 70803 USA. [Herman, Donald J.; Brodie, Eoin L.] Univ Calif Berkeley, Dept Environm Sci Policy & Management, Berkeley, CA 94720 USA. [Pett-Ridge, Jennifer] Lawrence Livermore Natl Lab, Div Chem Sci, Livermore, CA USA. RP Ceja-Navarro, JA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Earth Sci, Dept Ecol, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM JCNavarro@lbl.gov; ELBrodie@lbl.gov RI Ceja-Navarro, Javier/A-1731-2013; Andersen, Gary/G-2792-2015; Brodie, Eoin/A-7853-2008; Karaoz, Ulas/J-7093-2014 OI Ceja-Navarro, Javier/0000-0002-2954-3477; Andersen, Gary/0000-0002-1618-9827; Brodie, Eoin/0000-0002-8453-8435; FU Department of Energy, Office of Biological and Environmental Research, Genomic Sciences program through the Lawrence Livermore National Laboratory Biofuels Scientific Focus Area (SFA) award [SCW1039]; Department of Energy [DE-AC02-05CH11231]; US DOE at LLNL [DE-AC52-07NA27344]; NSF-GRFP program; LSU Boyd Professor Research fund; 'Consejo Nacional de Ciencia y Tecnologia' (CONACyT, Mexico) FX This work was supported by the Department of Energy, Office of Biological and Environmental Research, Genomic Sciences program through the Lawrence Livermore National Laboratory Biofuels Scientific Focus Area (SFA) award SCW1039. Part of this work (ELB, JAC-N, UK, GLA) was performed at Lawrence Berkeley National Laboratory under the Department of Energy contract number DE-AC02-05CH11231. Contributions of JPR are under the auspices of the US DOE at LLNL (DE-AC52-07NA27344). Additional support was provided from the NSF-GRFP program to NHN, the LSU Boyd Professor Research fund to MB, and JAC-N was also supported in part by a grant from 'Consejo Nacional de Ciencia y Tecnologia' (CONACyT, Mexico). We thank Hector Urbina for collection of beetles; George Stanley for help in conducting the nitrogen uptake experiments; Doug Wendell and Gail Ackermann form the QIIME-DB for their support with the submission of the sequencing data to the EBI. NR 62 TC 12 Z9 14 U1 4 U2 45 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 1751-7362 EI 1751-7370 J9 ISME J JI ISME J. PD JAN PY 2014 VL 8 IS 1 BP 6 EP 18 DI 10.1038/ismej.2013.134 PG 13 WC Ecology; Microbiology SC Environmental Sciences & Ecology; Microbiology GA 274KM UT WOS:000328605200003 PM 23985746 ER PT J AU Pratt, LJ Rypina, II Ozgokmen, TM Wang, P Childs, H Bebieva, Y AF Pratt, L. J. Rypina, I. I. Oezgoekmen, T. M. Wang, P. Childs, H. Bebieva, Y. TI Chaotic advection in a steady, three-dimensional, Ekman-driven eddy SO JOURNAL OF FLUID MECHANICS LA English DT Article DE chaotic advection; geophysical and geological flows; ocean processes ID MIXED-LAYER INSTABILITIES; GEOSTROPHIC DOUBLE GYRE; SPECTRAL ELEMENT MODEL; LOCK-EXCHANGE SYSTEM; RELATIVE DISPERSION; MEANDERING JET; FLUID EXCHANGE; MONTEREY BAY; LAGRANGIAN TRANSPORT; COHERENT STRUCTURES AB We investigate and quantify stirring due to chaotic advection within a steady, three-dimensional, Ekman-driven, rotating cylinder flow. The flow field has vertical overturning and horizontal swirling motion, and is an idealization of motion observed in some ocean eddies. The flow is characterized by strong background rotation, and we explore variations in Ekman and Rossby numbers, E and R-o, over ranges appropriate for the ocean mesoscale and submesoscale. A high-resolution spectral element model is used in conjunction with linear analytical theory, weakly nonlinear resonance analysis and a kinematic model in order to map out the barriers, manifolds, resonance layers and other objects that provide a template for chaotic stirring. As expected, chaos arises when a radially symmetric background state is perturbed by a symmetry-breaking disturbance. In the background state, each trajectory lives on a torus and some of the latter survive the perturbation and act as barriers to chaotic transport, a result consistent with an extension of the KAM theorem for three-dimensional, volume-preserving flow. For shallow eddies, where E is O(1), the flow is dominated by thin resonant layers sandwiched between KAM-type barriers, and the stirring rate is weak. On the other hand, eddies with moderately small E experience thicker resonant layers, wider-spread chaos and much more rapid stirring. This trend reverses for sufficiently small E, corresponding to deep eddies, where the vertical rigidity imposed by strong rotation limits the stirring. The bulk stirring rate, estimated from a passive tracer release, confirms the non-monotonic variation in stirring rate with E. This result is shown to be consistent with linear Ekman layer theory in conjunction with a resonant width calculation and the Taylor-Proudman theorem. The theory is able to roughly predict the value of E at which stirring is maximum. For large disturbances, the stirring rate becomes monotonic over the range of Ekman numbers explored. We also explore variation in the eddy aspect ratio. C1 [Pratt, L. J.; Rypina, I. I.] Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. [Oezgoekmen, T. M.; Wang, P.] Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. [Childs, H.] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. [Bebieva, Y.] Yale Univ, Grad Sch Arts & Sci, New Haven, CT 06520 USA. RP Pratt, LJ (reprint author), Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. EM lpratt@whoi.edu RI Wang, Peng/C-3205-2016 OI Wang, Peng/0000-0003-2660-717X FU DOD (MURI) [N000141110087]; National Science Foundation [NSF-OCE-0725796] FX L.J.P., I.I.R., T.M.O. and P.W. have been supported on DOD (MURI) grant N000141110087, administered by the Office of Naval Research. I.I.R. and L.J.P. received additional support from Grant NSF-OCE-0725796 from the National Science Foundation. NR 80 TC 6 Z9 6 U1 4 U2 21 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0022-1120 EI 1469-7645 J9 J FLUID MECH JI J. Fluid Mech. PD JAN PY 2014 VL 738 BP 143 EP 183 DI 10.1017/jfm.2013.583 PG 41 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 272UI UT WOS:000328486400010 ER PT J AU Mitrano, PP Zenk, JR Benyahia, S Galvin, JE Dahl, SR Hrenya, CM AF Mitrano, Peter P. Zenk, John R. Benyahia, Sofiane Galvin, Janine E. Dahl, Steven R. Hrenya, Christine M. TI Kinetic-theory predictions of clustering instabilities in granular flows: beyond the small-Knudsen-number regime SO JOURNAL OF FLUID MECHANICS LA English DT Article DE granular media; kinetic theory; nonlinear instability ID FLUIDIZED-BEDS; GAS; EQUATIONS; SPHERES; ORDER AB In this work we quantitatively assess, via instabilities, a Navier-Stokes-order (small-Knudsen-number) continuum model based on the kinetic theory analogy and applied to inelastic spheres in a homogeneous cooling system. Dissipative collisions are known to give rise to instabilities, namely velocity vortices and particle clusters, for sufficiently large domains. We compare predictions for the critical length scales required for particle clustering obtained from transient simulations using the continuum model with molecular dynamics (MD) simulations. The agreement between continuum simulations and MD simulations is excellent, particularly given the presence of well-developed velocity vortices at the onset of clustering. More specifically, spatial mapping of the local velocity-field Knudsen numbers (Kn(u)) at the time of cluster detection reveals Kn(u) >> 1 due to the presence of large velocity gradients associated with vortices. Although kinetic-theory-based continuum models are based on a small-Kn (i.e. small-gradient) assumption, our findings suggest that, similar to molecular gases, Navier-Stokes-order (small-Kn) theories are surprisingly accurate outside their expected range of validity. C1 [Mitrano, Peter P.; Zenk, John R.; Dahl, Steven R.; Hrenya, Christine M.] Univ Colorado, Dept Chem & Biol Engn, Boulder, CO 80309 USA. [Benyahia, Sofiane; Galvin, Janine E.] Natl Energy Technol Lab, Morgantown, WV 26507 USA. RP Hrenya, CM (reprint author), Univ Colorado, Dept Chem & Biol Engn, Boulder, CO 80309 USA. EM hrenya@colorado.edu FU American Chemical Society [PRF 50885-ND9]; National Energy Technology Laboratory of the Department of Energy [DE-FE0007450] FX We are grateful to C. J. Ewasko for producing MD data. P.P.M., J.R.Z., S.R.D. and C.M.H. would like to acknowledge the funding provided by the American Chemical Society (Grant PRF 50885-ND9) and the National Energy Technology Laboratory of the Department of Energy (Grant DE-FE0007450). NR 48 TC 8 Z9 8 U1 1 U2 26 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0022-1120 EI 1469-7645 J9 J FLUID MECH JI J. Fluid Mech. PD JAN PY 2014 VL 738 AR R2 DI 10.1017/jfm.2013.602 PG 12 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 272UI UT WOS:000328486400002 ER PT J AU Bailey, DH Borwein, JM Kaiser, AD AF Bailey, David H. Borwein, Jonathan M. Kaiser, Alexander D. TI Automated simplification of large symbolic expressions SO JOURNAL OF SYMBOLIC COMPUTATION LA English DT Article DE Simplification; Computer algebra systems; Experimental mathematics; Error correction ID ALGEBRAIC SIMPLIFICATION; BOX INTEGRALS; SUMS AB We present a set of algorithms for automated simplification of symbolic constants of the form Sigma(i)alpha(i)chi(i), with a; rational and x; complex. The included algorithms, called SimplifySum(2) and implemented in Mathematica, remove redundant terms, attempt to make terms and the full expression real, and remove terms using repeated application of the multipair PSLQ integer relation detection algorithm. Also included are facilities for making substitutions according to user-specified identities. We illustrate this toolset by giving some real-world examples of its usage, including one, for instance, where the tool reduced a symbolic expression of approximately 100000 characters in size enough to enable manual manipulation to one with just four simple terms. (C) 2013 Published by Elsevier B.V. C1 [Bailey, David H.] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. [Borwein, Jonathan M.] Univ Newcastle, Ctr Comp Assisted Res Math & Applicat CARMA, Callaghan, NSW 2308, Australia. [Kaiser, Alexander D.] NYU, Courant Inst Math Sci, New York, NY 10012 USA. RP Bailey, DH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. EM dhbailey@lbl.gov; jonathan.borwein@newcastle.edu.au; kaiser@cims.nyu.edu FU Office of Computational and Technology Research, Division of Mathematical, Information, and Computational Sciences of the U.S. Department of Energy [DE-AC02-05CH11231] FX Supported in part by the Director, Office of Computational and Technology Research, Division of Mathematical, Information, and Computational Sciences of the U.S. Department of Energy, under contract number DE-AC02-05CH11231. NR 36 TC 0 Z9 0 U1 0 U2 0 PU ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0747-7171 J9 J SYMB COMPUT JI J. Symb. Comput. PD JAN PY 2014 VL 60 BP 120 EP 136 DI 10.1016/j.jsc.2013.09.001 PG 17 WC Computer Science, Theory & Methods; Mathematics, Applied SC Computer Science; Mathematics GA 275FF UT WOS:000328661000009 ER PT J AU Li, JN Chylek, P Zhang, F AF Li, Jiangnan Chylek, Petr Zhang, Feng TI The Dissipation Structure of Extratropical Cyclones SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article DE Cyclogenesis; cyclolysis; Extratropical cyclones; Entropy; Thermodynamics ID ENTROPY PRODUCTION; LIFE-CYCLE; BAROCLINIC WAVES; CLIMATE MODELS; MARINE CYCLONE; PART I; WINTER CYCLONE; SYSTEM; EARTH; CYCLOGENESIS AB The physical characteristics of extratropical cyclones are investigated based on nonequilibrium thermodynamics. Nonequilibrium thermodynamics, using entropy as its main tool, has been widely used in many scientific fields. The entropy balance equation contains two parts: the internal entropy production corresponds to dissipation and the external entropy production corresponds to boundary entropy supply. It is shown that dissipation is always present in a cyclone and the dissipation center is not always coincident with the low-pressure center, especially for incipient cyclones. The different components of internal entropy production correspond to different dissipation processes. Usually the thermal dissipation due to turbulent vertical diffusion and convection lags geographically the dynamic dissipation due to wind stress. At the incipient stage, the dissipation is mainly thermal in nature. A concept of temperature shear is introduced as the result of thermal dissipation. The temperature shear provides a useful diagnostic for extratropical cyclone identification. The boundary entropy supply and the entropy advection are also strongly associated with cyclones. The entropy advection is generally positive (negative) in the leading (trailing) part of a cyclone. A regional study in the western Pacific clearly demonstrates that the surface entropy flux and temperature shear are the most reliable early signals of cyclones in the cyclogenesis stage. C1 [Li, Jiangnan] Univ Victoria, Canadian Ctr Climate Modelling & Anal, Environm Canada, Sci & Technol Branch, Victoria, BC V8W 3V6, Canada. [Chylek, Petr] Los Alamos Natl Lab, Los Alamos, NM USA. [Zhang, Feng] Univ Chinese Acad Sci, Chinese Acad Meteorol Sci, Beijing, Peoples R China. [Zhang, Feng] Shanghai Typhoon Inst China Meteorol Adm, Shanghai, Peoples R China. RP Li, JN (reprint author), Univ Victoria, Canadian Ctr Climate Modelling & Anal, POB 3065, Victoria, BC V8W 3V6, Canada. EM jiangnan.li@ec.gc.ca RI Li, Jiangnan/J-6262-2016 NR 56 TC 2 Z9 2 U1 1 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PD JAN PY 2014 VL 71 IS 1 BP 69 EP 88 DI 10.1175/JAS-D-13-037.1 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 278ZM UT WOS:000328928400005 ER PT J AU Saleh, AA Pereloma, EV Clausen, B Brown, DW Tome, CN Gazder, AA AF Saleh, Ahmed A. Pereloma, Elena V. Clausen, Bjorn Brown, Donald W. Tome, Carlos N. Gazder, Azdiar A. TI Self-consistent modelling of lattice strains during the in-situ tensile loading of twinning induced plasticity steel SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE TWIP; Neutron diffraction; EPSC; Lattice strains; Latent hardening ID MANGANESE AUSTENITIC STEELS; STAINLESS-STEEL; NEUTRON-DIFFRACTION; ELASTIC-CONSTANTS; FCC POLYCRYSTALS; DEFORMATION-BEHAVIOR; STRESS-RELAXATION; EVOLUTION; TEXTURE; MICROSTRUCTURE AB The evolution of lattice strains in a fully recrystallised Fe-24Mn-3Al-2Si-1Ni-0.06C TWinning Induced Plasticity (TWIP) steel subjected to uniaxial tensile loading up to a true strain of similar to 35% was investigated via in-situ neutron diffraction. Typical of fcc elastic and plastic anisotropy, the {111} and {200} grain families record the lowest and highest lattice strains, respectively. Using modelling cases with and without latent hardening, the recently extended Elasto-Plastic Self-Consistent model successfully predicted the macroscopic stress-strain response, the evolution of lattice strains and the development of crystallographic texture. Compared to the isotropic hardening case, latent hardening did not have a significant effect on lattice strains and returned a relatively faster development of a stronger < 111 > and a weaker < 100 > double fibre parallel to the tensile axis. Close correspondence between the experimental lattice strains and those predicted using particular orientations embedded within a random aggregate was obtained. The result suggests that the exact orientations of the surrounding aggregate have a weak influence on the lattice strain evolution. (C) 2013 Elsevier B.V. All rights reserved. C1 [Saleh, Ahmed A.; Pereloma, Elena V.; Gazder, Azdiar A.] Univ Wollongong, Sch Mech Mat & Mechatron Engn, Wollongong, NSW 2522, Australia. [Pereloma, Elena V.; Gazder, Azdiar A.] Univ Wollongong, Ctr Electron Microscopy, Wollongong, NSW 2519, Australia. [Clausen, Bjorn] Los Alamos Natl Lab, Los Alamos Neutron Sci Ctr, Los Alamos, NM 87545 USA. [Brown, Donald W.; Tome, Carlos N.] Los Alamos Natl Lab, Mat Sci & Technol Div, Los Alamos, NM 87545 USA. RP Saleh, AA (reprint author), Univ Wollongong, Sch Mech Mat & Mechatron Engn, Wollongong, NSW 2522, Australia. EM asaleh@uow.edu.au RI Clausen, Bjorn/B-3618-2015; Tome, Carlos/D-5058-2013; OI Clausen, Bjorn/0000-0003-3906-846X; Saleh, Ahmed/0000-0002-0807-6718 FU Commonwealth of Australia under the International Science Linkages program; Office of Basic Energy Sciences (DOE); U.S. DOE [DE AC52 06NA25396]; U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under U.S. DOE [FWP 06SCPE401, W-7405-ENG-36] FX The access to major research facilities program (AMRFP) is supported by the Commonwealth of Australia under the International Science Linkages program. This work has benefited from the use of the Lujan Neutron Scattering Center at LANSCE, which is funded by the Office of Basic Energy Sciences (DOE). Los Alamos National Laboratory is operated by the Los Alamos National Security LLC under U.S. DOE Contract DE AC52 06NA25396. The authors are grateful to Prof. D.B. Santos of the Federal University of Minas Gerais, Brazil for providing the source material. Dr. C. N. Tome was fully supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, Project FWP 06SCPE401 under U.S. DOE Contract no. W-7405-ENG-36. NR 41 TC 7 Z9 7 U1 1 U2 24 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 EI 1873-4936 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JAN 1 PY 2014 VL 589 BP 66 EP 75 DI 10.1016/j.msea.2013.09.073 PG 10 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 273FX UT WOS:000328521800008 ER PT J AU Cakmak, E Vogel, SC Choo, H AF Cakmak, Ercan Vogel, Sven C. Choo, Hahn TI Effect of martensitic phase transformation on the hardening behavior and texture evolution in a 304L stainless steel under compression at liquid nitrogen temperature SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE Neutron scattering; Steel; Martensitic transformations; Martensite; Strain measurement; Plasticity ID X-RAY-DIFFRACTION; STACKING-FAULT ENERGY; NEUTRON-DIFFRACTION; MECHANICAL-PROPERTIES; TRIP STEEL; DEFORMATION; DIFFRACTOMETER; DEPENDENCE; KINETICS; TORSION AB The martensitic phase transformation behavior and its relations with the macroscopic hardening rate and the evolutions in the crystallographic texture of the constituent phases were studied for a 304L stainless steel that exhibits the transformation induced plasticity (TRIP) phenomenon. Time-of-flight neutron diffraction was used to measure the evolutions of phase fractions and texture in terms of pole figures as a function of the applied compressive strain at the liquid nitrogen temperature (77 K). The phase transformation analyses show that the hcp-martensite phase fraction reaches a significant level of about 22 wt% at 15% applied strain and remains constant. The bcc-martensite phase fraction increases continuously with the deformation that correlates well with the macroscopic hardening behavior. Furthermore, the texture analyses show that transformation has dominant effect on the bcc-martensite texture evolution with little influence from subsequent plastic deformation at current testing conditions. Published by Elsevier B.V. C1 [Cakmak, Ercan; Choo, Hahn] Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. [Vogel, Sven C.] Los Alamos Natl Lab, Los Alamos Neutron Sci Ctr, Los Alamos, NM 87545 USA. RP Choo, H (reprint author), Univ Tennessee, Dept Mat Sci & Engn, 411 Ferris Hall, Knoxville, TN 37996 USA. EM hchoo@utk.edu RI Cakmak, Ercan/J-8605-2014; Choo, Hahn/A-5494-2009; OI Choo, Hahn/0000-0002-8006-8907; Vogel, Sven C./0000-0003-2049-0361 FU DOE Office of Basic Energy Sciences; DOE [DE-AC52-06NA25396] FX This work has benefited from the use of the Lujan Neutron Scattering Center at LANSCE, funded by the DOE Office of Basic Energy Sciences. Los Alamos National Laboratory is operated by Los Alamos National Security LLC under DOE Contract DE-AC52-06NA25396. NR 34 TC 7 Z9 7 U1 3 U2 19 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 EI 1873-4936 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD JAN 1 PY 2014 VL 589 BP 235 EP 241 DI 10.1016/j.msea.2013.09.093 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 273FX UT WOS:000328521800029 ER PT J AU Chorin, AJ Hald, OH AF Chorin, Alexandre J. Hald, Ole H. TI Estimating the uncertainty in underresolved nonlinear dynamics SO MATHEMATICS AND MECHANICS OF SOLIDS LA English DT Article DE Noise; memory; approximation; data assimilation; Monte Carlo ID ASSIMILATION; EQUATIONS; FILTERS; ERROR AB The Mori-Zwanzig formalism of statistical mechanics is used to estimate the uncertainty caused by underresolution in the solution of a nonlinear dynamical system. A general approach is outlined and applied to a simple example. The noise term that describes the uncertainty turns out to be neither Markovian nor Gaussian. It is argued that this is the general situation. C1 [Chorin, Alexandre J.] Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Chorin, AJ (reprint author), Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. EM chorin@math.berkeley.edu FU Office of Science, Computational and Technology Research, U.S. Department of Energy [DE-AC02-05CH11231]; National Science Foundation [DMS-1217065] FX This work was supported by the Director, Office of Science, Computational and Technology Research, U.S. Department of Energy (contract number DE-AC02-05CH11231), and by the National Science Foundation (grant number DMS-1217065). NR 28 TC 3 Z9 3 U1 0 U2 6 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 1081-2865 EI 1741-3028 J9 MATH MECH SOLIDS JI Math. Mech. Solids PD JAN PY 2014 VL 19 IS 1 SI SI BP 28 EP 38 DI 10.1177/1081286513505465 PG 11 WC Materials Science, Multidisciplinary; Mathematics, Interdisciplinary Applications; Mechanics SC Materials Science; Mathematics; Mechanics GA 274HV UT WOS:000328598300004 ER PT J AU Rodriguez-Lopez, J Martinez-Centeno, C Padmanaban, A Guillen, G Olivares, JE Stefano, G Lledias, F Ramos, F Ghabrial, SA Brandizzi, F Rocha-Sosa, M Diaz-Camino, C Sanchez, F AF Rodriguez-Lopez, Jonathan Martinez-Centeno, Cynthia Padmanaban, Annamalai Guillen, Gabriel Elias Olivares, Juan Stefano, Giovanni Lledias, Fernando Ramos, Fernando Ghabrial, Said A. Brandizzi, Federica Rocha-Sosa, Mario Diaz-Camino, Claudia Sanchez, Federico TI Nodulin 22, a Novel Small Heat-Shock Protein of the Endoplasmic Reticulum, Is Linked to the Unfolded Protein Response in Common Bean SO MOLECULAR PLANT-MICROBE INTERACTIONS LA English DT Article ID POD-MOTTLE-VIRUS; SYSTEMIC ACQUIRED-RESISTANCE; HETEROTRIMERIC G-PROTEIN; MEDIATED CELL-DEATH; ARABIDOPSIS-THALIANA; FUNCTIONAL GENOMICS; DISEASE RESISTANCE; DENATURED PROTEIN; OXIDATIVE STRESS; PLANTS AB The importance of plant small heat shock proteins (sHsp) in multiple cellular processes has been evidenced by their unusual abundance and diversity; however, little is known about their biological role. Here, we characterized the in vitro chaperone activity and subcellular localization of nodulin 22 of Phaseolus vulgaris (PvNod22; common bean) and explored its cellular function through a virus-induced gene silencing based reverse genetics approach. We established that PvNod22 facilitated the refolding of a model substrate in vitro, suggesting that it acts as a molecular chaperone in the cell. Through microscopy analyses of PvNod22, we determined its localization in the endoplasmic reticulum (ER). Furthermore, we found that silencing of PvNod22 resulted in necrotic lesions in the aerial organs of P. vulgaris plants cultivated under optimal conditions and that downregulation of PvNod22 activated the ER-unfolded protein response (UPR) and cell death. We also established that PvNod22 expression in wild-type bean plants was modulated by abiotic stress but not by chemicals that trigger the UPR, indicating PvNod22 is not under UPR control. Our results suggest that the ability of PvNod22 to suppress protein aggregation contributes to the maintenance of ER homeostasis, thus preventing the induction of cell death via UPR in response to oxidative stress during plant-microbe interactions. C1 [Rodriguez-Lopez, Jonathan; Martinez-Centeno, Cynthia; Guillen, Gabriel; Elias Olivares, Juan; Lledias, Fernando; Rocha-Sosa, Mario; Diaz-Camino, Claudia; Sanchez, Federico] Univ Nacl Autonoma Mexico, Dept Biol Mol Plantas, Inst Biotecnol, Cuernavaca 62210, Morelos, Mexico. [Padmanaban, Annamalai; Ghabrial, Said A.] Univ Kentucky, Dept Plant Pathol, Lexington, KY 40546 USA. [Stefano, Giovanni; Brandizzi, Federica] Michigan State Univ, DOE Plant Res Lab, E Lansing, MI 48824 USA. [Ramos, Fernando] Dept Comp Sci, Cuernavaca, Morelos, Mexico. RP Diaz-Camino, C (reprint author), Univ Nacl Autonoma Mexico, Dept Biol Mol Plantas, Inst Biotecnol, Av Univ 2001, Cuernavaca 62210, Morelos, Mexico. EM claudia@ibt.unam.mx RI STEFANO, GIOVANNI/A-8264-2011 OI STEFANO, GIOVANNI/0000-0002-2744-0052 FU Consejo Nacional de Ciencia y Tecnologia [89754, 177207, 177744]; Programa de Apoyo a Proyectos de Investigacion e Innovacion Tecnologica/Universidad Nacional Autonoma de Mexico [IN201412, IN106012]; Kentucky Science and Engineering Foundation [KSEF-2178-RDE-013]; National Institutes of Health [R01 GM101038-01]; National Science Foundation [MCB 0948584, MCB1243792]; Chemical Sciences, Geosciences and Biosciences Division, Office of Basic Energy Sciences, Office of Science, US DOE [DE-FG02-91ER20021] FX We thank P. R. Benitez, A. S. Amaro (Universidad Nacional Autonoma de Mexico), and W. Havens (University of Kentucky) for technical assistance. This work was supported in part by the Consejo Nacional de Ciencia y Tecnologia 89754 and 177207 to C. Diaz-Camino and 177744 to F. Sanchez; by the Programa de Apoyo a Proyectos de Investigacion e Innovacion Tecnologica/Universidad Nacional Autonoma de Mexico IN201412 to C. Diaz-Camino and IN106012 to E Sanchez, and by the Kentucky Science and Engineering Foundation (KSEF-2178-RDE-013) to S. A. Ghabrial. We also acknowledge support by the grants to F. Brandizzi from the National Institutes of Health (R01 GM101038-01) and the National Science Foundation (MCB 0948584 and MCB1243792) for partial support to G. Stefano and Chemical Sciences, Geosciences and Biosciences Division, Office of Basic Energy Sciences, Office of Science, US DOE (DE-FG02-91ER20021) for infrastructure (F. Brandizzi). NR 59 TC 2 Z9 2 U1 1 U2 15 PU AMER PHYTOPATHOLOGICAL SOC PI ST PAUL PA 3340 PILOT KNOB ROAD, ST PAUL, MN 55121 USA SN 0894-0282 EI 1943-7706 J9 MOL PLANT MICROBE IN JI Mol. Plant-Microbe Interact. PD JAN PY 2014 VL 27 IS 1 BP 18 EP 29 DI 10.1094/MPMI-07-13-0200-R PG 12 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Plant Sciences SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Plant Sciences GA 275FN UT WOS:000328661800002 PM 24073881 ER PT J AU Childress, MJ Filippenko, AV Ganeshalingam, M Schmidt, BP AF Childress, Michael J. Filippenko, Alexei V. Ganeshalingam, Mohan Schmidt, Brian P. TI High-velocity features in Type Ia supernova spectra SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE supernovae: general ID DELAYED-DETONATION MODELS; PHOTOMETRY DATA RELEASE; LIGHT-CURVE SHAPES; IMPROVED DISTANCES; SN 2011FE; REDSHIFT; ULTRAVIOLET; PROGRAM; BRIGHTNESS; LUMINOSITY AB We use a sample of 58 low-redshift (z <= 0.03) Type Ia supernovae (SNe Ia) having well-sampled light curves and spectra near maximum light to examine the behaviour of high-velocity features (HVFs) in SN Ia spectra. We take advantage of the fact that Si II lambda 6355 is free of HVFs at maximum light in all SNe Ia, while HVFs are still strong in the Ca II near-infrared feature in many SNe, allowing us to quantify the strength of HVFs by comparing the structure of these two lines. We find that the average HVF strength increases with decreasing light-curve decline rate, and rapidly declining SNe Ia (Delta m(15)(B) >= 1.4 mag) show no HVFs in their maximum-light spectra. Comparison of HVF strength to the light-curve colour of the SNe Ia in our sample shows no evidence of correlation. We find a correlation of HVF strength with the velocity of Si II lambda 6355 at maximum light (v(Si)), such that SNe Ia with lower v(Si) have stronger HVFs, while those SNe Ia firmly in the 'high-velocity' (i.e. v(Si) >= 12 000 km s(-1)) subclass exhibit no HVFs in their maximum-light spectra. While v(Si) and Delta m(15)(B) show no correlation in the full sample of SNe Ia, we find a significant correlation between these quantities in the subset of SNe Ia having weak HVFs. In general, we find that slowly declining (low Delta m(15)(B)) SNe Ia, which are more luminous and more energetic than average SNe Ia, tend to produce either high photospheric ejecta velocities (i.e. high v(Si)) or strong HVFs at maximum light, but not both. Finally, we examine the evolution of HVF strength for a sample of SNe Ia having extensive pre-maximum spectroscopic coverage and find significant diversity of the pre-maximum HVF behaviour. C1 [Childress, Michael J.; Schmidt, Brian P.] Australian Natl Univ, Res Sch Astron & Astrophys, Canberra, ACT 2611, Australia. [Childress, Michael J.; Schmidt, Brian P.] Univ Calif Berkeley, ARC Ctr Excellence All Sky Astrophys CAASTRO, Berkeley, CA 94720 USA. [Filippenko, Alexei V.; Ganeshalingam, Mohan] Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. [Ganeshalingam, Mohan] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Childress, MJ (reprint author), Australian Natl Univ, Res Sch Astron & Astrophys, Canberra, ACT 2611, Australia. EM mjc@mso.anu.edu.au OI Schmidt, Brian/0000-0001-6589-1287 FU Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO) [CE110001020]; Australian Research Council Laureate Fellowship [LF0992131]; NSF [AST-1211916]; TABASGO Foundation; Christopher R. Redlich Fund; Sun Microsystems, Inc.; Hewlett-Packard Company; AutoScope Corporation; Lick Observatory; NSF; University of California; Sylvia & Jim Katzman Foundation; Richard and Rhoda Goldman Fund FX We thank Stefan Taubenberger for providing his spectra of SN 2005bl; Jeffrey Silverman for his hard work on the BSNIP sample; the late Weidong Li for his key role in obtaining the KAIT light curves published by LOSS (Ganeshalingam et al. 2010); Stuart Sim, Richard Scalzo, Brad Tucker and Ryan Foley for helpful discussions; and the Lick Observatory staff for their assistance with the observations. We also thank the anonymous referee for thoughtful and constructive comments. This research was conducted by the Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO), through project number CE110001020. BPS acknowledges support from the Australian Research Council Laureate Fellowship Grant LF0992131. AVF is grateful for the generous financial support of NSF grant AST-1211916, the TABASGO Foundation, and the Christopher R. Redlich Fund. KAIT has been funded by donations from Sun Microsystems, Inc., the Hewlett-Packard Company, AutoScope Corporation, Lick Observatory, the NSF, the University of California, the Sylvia & Jim Katzman Foundation, the Christopher R. Redlich Fund, the Richard and Rhoda Goldman Fund and the TABASGO Foundation. This research has made use of NASA's Astrophysics Data System (ADS). NR 60 TC 29 Z9 29 U1 1 U2 8 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0035-8711 EI 1365-2966 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JAN PY 2014 VL 437 IS 1 BP 338 EP 350 DI 10.1093/mnras/stt1892 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 271EB UT WOS:000328373000047 ER PT J AU Wang, LL Reid, B White, M AF Wang, Lile Reid, Beth White, Martin TI An analytic model for redshift-space distortions SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE gravitation; galaxies: haloes; galaxies: statistics; cosmological parameters; large-scale structure of Universe ID PERTURBATION-THEORY; LINEAR REGIME; GRAVITATIONAL-INSTABILITY; EVOLUTION; FLUCTUATIONS; EXPANSION; GALAXIES; DENSITY AB Understanding the formation and evolution of large-scale structure is a central problem in cosmology and enables precise tests of General Relativity on cosmological scales and constraints on dark energy. An essential ingredient is an accurate description of the pairwise velocities of biased tracers of the matter field. In this paper, we compute the first and second moments of the pairwise velocity distribution by extending the convolution Lagrangian perturbation theory (CLPT) formalism of Carlson et al. Our predictions outperform standard perturbation theory calculations in many cases when compared to statistics measured in N-body simulations. We combine the CLPT predictions of real-space clustering and velocity statistics in the Gaussian streaming model of Reid & White to obtain predictions for the monopole and quadrupole correlation functions accurate to 2 and 4 per cent, respectively, down to <25 h(-1) Mpc for haloes hosting the massive galaxies observed by SDSS-III BOSS. We also discuss contours of the 2D correlation function and clustering 'wedges'. We generalize the scheme to cross-correlation functions. C1 [Wang, Lile; Reid, Beth; White, Martin] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. [Wang, Lile] Tsinghua Univ, Dept Phys, Beijing 100084, Peoples R China. [Wang, Lile] Tsinghua Univ, Tsinghua Ctr Astrophys THCA, Beijing 100084, Peoples R China. [White, Martin] Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. [White, Martin] Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. RP Wang, LL (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM mwhite@berkeley.edu RI White, Martin/I-3880-2015 OI White, Martin/0000-0001-9912-5070 NR 34 TC 21 Z9 21 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0035-8711 EI 1365-2966 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JAN PY 2014 VL 437 IS 1 BP 588 EP 599 DI 10.1093/mnras/stt1916 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 271EB UT WOS:000328373000066 ER PT J AU Obergaulinger, M Iyudin, AF Mueller, E Smoot, GF AF Obergaulinger, M. Iyudin, A. F. Mueller, E. Smoot, G. F. TI Hydrodynamic simulations of the interaction of supernova shock waves with a clumpy environment: the case of the RX J0852.0-4622 (Vela Jr) supernova remnant SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE hydrodynamics; supernovae: general; ISM: supernova remnants ID CORE-COLLAPSE SUPERNOVAE; ULTRAVIOLET SPECTRAL IMAGES; X-RAY-EMISSION; INTERSTELLAR CLOUDS; NEUTRAL HYDROGEN; GUM NEBULA; CIRCUMSTELLAR MEDIUM; MOLECULAR CLOUDS; NORTHWESTERN RIM; YOUNG REMNANTS AB Observations in all electromagnetic bands show that many supernova remnants (SNRs) have a very aspherical shape. This can be the result of asymmetries in the supernova explosion or a clumpy circumstellar medium. We study the generation of inhomogeneities and the mixing of elements arising from these two sources in multidimensional hydrodynamic simulations of the propagation of a supernova blast wave into a cloudy environment. We model a specific SNR, Vela Jr (RX J0852.0-4622). By comparing our results with recent observations, we can constrain the properties of the explosion. We find that a very energetic explosion of several 10(51) erg occurring roughly about 800 years ago is consistent with the shape and emission of the SNR, as well as a supernova with an energy closer to the canonical value of 10(51) erg a few thousand years ago. C1 [Obergaulinger, M.] Univ Valencia, Dept Astron & Astrofis, E-46100 Burjassot, Valencia, Spain. [Iyudin, A. F.; Smoot, G. F.] Moscow MV Lomonosov State Univ, Skobeltsyn Inst Nucl Phys, Extreme Universe Lab, Moscow 119991, Russia. [Iyudin, A. F.] Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. [Mueller, E.] Max Planck Inst Astrophys, D-85748 Garching, Germany. [Smoot, G. F.] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Obergaulinger, M (reprint author), Univ Valencia, Dept Astron & Astrofis, Edifici Invest Jeroni Munyoz,C Dr Moliner 50, E-46100 Burjassot, Valencia, Spain. EM martin.obergaulinger@uv.es FU RF [11.G34.31.0076]; European Research Council [CAMAP-259276]; Spanish Ministerio de Ciencia e Innovacion [AYA2010-21097-C03-01] FX AFI and GFS were partially supported through the Grant of RF '11.G34.31.0076'. AFI acknowledges discussions and joint work with N. Chugai and Yu. V. Pakhomov related to the optical properties of Vela Jr and thanks V. Burwitz, K. Dennerl and F. Haberl for their contribution to the X-ray imaging of RX J0852.0-4622 and especially Bernd Aschenbach for his unwavering support of the whole effort to prove the youth of the remnant. MO acknowledges discussions with M. A. Aloy, D. Patnaude, R. Fesen and D. Milisavlejic as well as support from the European Research Council (grant CAMAP-259276) and from the Spanish Ministerio de Ciencia e Innovacion (grant AYA2010-21097-C03-01 Astrofisica Relativista Computacional). We are grateful for technical support by the system administrators of the Universitat de Valencia, in particular C. Aloy. We thank the anonymous referee for valuable comments. NR 64 TC 8 Z9 8 U1 1 U2 3 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0035-8711 EI 1365-2966 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JAN PY 2014 VL 437 IS 1 BP 976 EP 993 DI 10.1093/mnras/stt1966 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 271EB UT WOS:000328373000100 ER PT J AU Cassataro, D Bergfeldt, D Malekian, C Van Snellenberg, JX Thanos, PK Fishell, G Sjulson, L AF Cassataro, Daniela Bergfeldt, Daniella Malekian, Cariz Van Snellenberg, Jared X. Thanos, Panayotis K. Fishell, Gord Sjulson, Lucas TI Reverse Pharmacogenetic Modulation of the Nucleus Accumbens Reduces Ethanol Consumption in a Limited Access Paradigm SO NEUROPSYCHOPHARMACOLOGY LA English DT Article DE alcohol dependence; reverse pharmacogenetics; nucleus accumbens; drinking in the dark; DREADDs ID PROTEIN-COUPLED RECEPTORS; STEREOTACTIC SURGERY; ALCOHOL-CONSUMPTION; REMOTE-CONTROL; C57BL/6J MICE; GENE-TRANSFER; DRINKING; MODEL; OVEREXPRESSION; EXPRESSION AB Bilateral stereotactic lesioning of the nucleus accumbens (NAc) core reduces relapse rates in alcohol-dependent patients but may cause irreversible cognitive deficits. Deep brain stimulation has similar effects but requires costly implanted hardware and regular surgical maintenance. Therefore, there is considerable interest in refining these approaches to develop reversible, minimally invasive treatments for alcohol dependence. Toward this end, we evaluated the feasibility of a reverse pharmacogenetic approach in a preclinical mouse model. We first assessed the predictive validity of a limited access ethanol consumption paradigm by confirming that electrolytic lesions of the NAc core decreased ethanol consumption, recapitulating the effects of similar lesions in humans. We then used this paradigm to test the effect of modulating activity in the NAc using the Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) hM3Dq and hM4Di. We found that increasing activity with hM3Dq had no effect, but suppressing activity with hM4Di reduced alcohol consumption to a similar extent as lesioning without affecting consumption of water or sucrose. These results may represent early steps toward a novel neurosurgical treatment modality for alcohol dependence that is reversible and externally titratable, yet highly targetable and less invasive than current approaches such as lesioning or deep brain stimulation. C1 [Cassataro, Daniela; Sjulson, Lucas] NYU, Sch Med, Dept Psychiat, New York, NY 10016 USA. [Cassataro, Daniela; Bergfeldt, Daniella; Malekian, Cariz; Fishell, Gord; Sjulson, Lucas] NYU, Inst Neurosci, Dept Neurosci & Physiol, Smilow Neurosci Program, New York, NY USA. [Bergfeldt, Daniella] Karolinska Inst, Dept Med Biochem & Biophys, Stockholm, Sweden. [Malekian, Cariz] Uppsala Univ, Uppsala Biomed Ctr, Dept Med, Polacksbacken, Sweden. [Van Snellenberg, Jared X.] Columbia Univ Coll Phys & Surg, New York State Psychiat Inst, Dept Psychiat, Div Translat Imaging, New York, NY 10032 USA. [Thanos, Panayotis K.] NIAAA, Neuroimaging Lab, Intramural Program, NIH, Bethesda, MD USA. [Thanos, Panayotis K.] Brookhaven Natl Lab, Dept Med, Behav Pharmacol & Neuroimaging Lab, Upton, NY 11973 USA. RP Sjulson, L (reprint author), NYU, Sch Med, Dept Psychiat, Smilow 507,522 1st Ave, New York, NY 10016 USA. EM Lucas.Sjulson@nyumc.org RI Van Snellenberg, Jared/F-7889-2013 OI Van Snellenberg, Jared/0000-0003-2442-2008 FU NINDS; NYU Physician Scientist Training Program; NYU Dean's Undergraduate Research Fund; NIH [R01 MH068469, R01 MH071679, R01 MH095147, R01 NS081297]; National Center for Advancing Translational Sciences, National Institutes of Health [UL1 TR000038] FX We thank Michael Krashes, Brad Lowell, Bryan Roth, and Jurgen Wess for sharing DREADD constructs and reagents. CNO was obtained from the NIH as part of the Rapid Access to Investigative Drug Program funded by the NINDS. We also thank Michael Long and Dmitriy Aronov for advice on electrolytic lesions, Charles Hoeffer and the NYU rodent behavior core facility for help with behavioral assays, and Jens Hjerling-Leffler for valuable comments on the manuscript. This work was supported by funds from the NYU Physician Scientist Training Program (LS); the NYU Dean's Undergraduate Research Fund (DC); NIH grants R01 MH068469, R01 MH071679, R01 MH095147, and R01 NS081297 to GF; and grant UL1 TR000038 from the National Center for Advancing Translational Sciences, National Institutes of Health. NR 36 TC 12 Z9 12 U1 2 U2 8 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0893-133X EI 1740-634X J9 NEUROPSYCHOPHARMACOL JI Neuropsychopharmacology PD JAN PY 2014 VL 39 IS 2 BP 283 EP 290 DI 10.1038/npp.2013.184 PG 8 WC Neurosciences; Pharmacology & Pharmacy; Psychiatry SC Neurosciences & Neurology; Pharmacology & Pharmacy; Psychiatry GA 274DM UT WOS:000328585400005 PM 23903031 ER PT J AU O'Hara, MJ AF O'Hara, Michael J. TI On the perturbation of rank-one symmetric tensors SO NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS LA English DT Article DE symmetric rank-one approximation; symmetric tensors; tensors; higher-order power method; shifted higher-order power method; tensor eigenvalues; Z-eigenpairs; l(2) eigenpairs; blind source separation; independent components analysis ID ORDER SUPERSYMMETRIC TENSORS; APPROXIMATION AB The problem of symmetric rank-one approximation of symmetric tensors is important in independent components analysis, also known as blind source separation, as well as polynomial optimization. We derive several perturbative results that are relevant to the well-posedness of recovering rank-one structure from approximately-rank-one symmetric tensors. We also specialize the analysis of the shifted symmetric higher-order power method, an algorithm for computing symmetric tensor eigenvectors, to approximately-rank-one symmetric tensors. Copyright (c) 2012 John Wiley & Sons, Ltd. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP O'Hara, MJ (reprint author), Lawrence Livermore Natl Lab, Mailbox L-363,7000 East Ave, Livermore, CA 94550 USA. EM mjohara@gmail.com NR 13 TC 1 Z9 1 U1 0 U2 7 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1070-5325 EI 1099-1506 J9 NUMER LINEAR ALGEBR JI Numer. Linear Algebr. Appl. PD JAN PY 2014 VL 21 IS 1 BP 1 EP 12 DI 10.1002/nla.1851 PG 12 WC Mathematics, Applied; Mathematics SC Mathematics GA 272JA UT WOS:000328455200001 ER PT J AU Sousedik, B Ghanem, RG Phipps, ET AF Sousedik, Bedrich Ghanem, Roger G. Phipps, Eric T. TI Hierarchical Schur complement preconditioner for the stochastic Galerkin finite element methods Dedicated to Professor Ivo Marek on the occasion of his 80th birthday SO NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS LA English DT Article DE stochastic Galerkin finite element methods; iterative methods; preconditioning; Schur complement; hierarchical and multilevel preconditioning ID PARTIAL-DIFFERENTIAL-EQUATIONS; RECURSIVE MULTILEVEL SOLVER; RANDOM INPUT DATA; COLLOCATION METHOD; ITERATIVE SOLVERS; LINEAR-SYSTEMS; APPROXIMATION AB Use of the stochastic Galerkin finite element methods leads to large systems of linear equations obtained by the discretization of tensor product solution spaces along their spatial and stochastic dimensions. These systems are typically solved iteratively by a Krylov subspace method. We propose a preconditioner, which takes an advantage of the recursive hierarchy in the structure of the global matrices. In particular, the matrices posses a recursive hierarchical two-by-two structure, with one of the submatrices block diagonal. Each of the diagonal blocks in this submatrix is closely related to the deterministic mean-value problem, and the action of its inverse is in the implementation approximated by inner loops of Krylov iterations. Thus, our hierarchical Schur complement preconditioner combines, on each level in the approximation of the hierarchical structure of the global matrix, the idea of Schur complement with loops for a number of mutually independent inner Krylov iterations, and several matrix-vector multiplications for the off-diagonal blocks. Neither the global matrix nor the matrix of the preconditioner need to be formed explicitly. The ingredients include only the number of stiffness matrices from the truncated Karhunen-Loeve expansion and a good preconditioned for the mean-value deterministic problem. We provide a condition number bound for a model elliptic problem, and the performance of the method is illustrated by numerical experiments. Copyright (c) 2013 John Wiley & Sons, Ltd. C1 [Sousedik, Bedrich; Ghanem, Roger G.] Univ So Calif, Dept Aerosp & Mech Engn, Los Angeles, CA 90089 USA. [Sousedik, Bedrich; Ghanem, Roger G.] Univ So Calif, Dept Civil & Environm Engn, Los Angeles, CA 90089 USA. [Sousedik, Bedrich] Acad Sci Czech Republic, Inst Thermomech, Prague 18200 8, Czech Republic. [Phipps, Eric T.] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Sousedik, B (reprint author), Univ So Calif, Dept Aerosp & Mech Engn, Olin Hall OHE 430, Los Angeles, CA 90089 USA. EM sousedik@usc.edu RI Ghanem, Roger/B-8570-2008; Sousedik, Bedrich/I-9257-2014 OI Ghanem, Roger/0000-0002-1890-920X; Sousedik, Bedrich/0000-0002-8053-8956 FU DOE/ASCR; Grant Agency of the Czech Republic [GA R 106/08/0403] FX Support from DOE/ASCR is gratefully acknowledged. B. Sousedik has been also supported in part by the Grant Agency of the Czech Republic GA R 106/08/0403. NR 37 TC 6 Z9 6 U1 1 U2 4 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1070-5325 EI 1099-1506 J9 NUMER LINEAR ALGEBR JI Numer. Linear Algebr. Appl. PD JAN PY 2014 VL 21 IS 1 BP 136 EP 151 DI 10.1002/nla.1869 PG 16 WC Mathematics, Applied; Mathematics SC Mathematics GA 272JA UT WOS:000328455200010 ER PT J AU Seabold, JA Zhu, K Neale, NR AF Seabold, Jason A. Zhu, Kai Neale, Nathan R. TI Efficient solar photoelectrolysis by nanoporous Mo: BiVO4 through controlled electron transport SO PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article ID PHOTOELECTROCHEMICAL WATER OXIDATION; SCANNING ELECTROCHEMICAL MICROSCOPY; VISIBLE-LIGHT IRRADIATION; HYDROGEN-PRODUCTION; OXYGEN EVOLUTION; METAL-OXIDE; MONOCLINIC BIVO4; TIO2 FILMS; CATALYST; CELLS AB A detailed understanding of doping level, electron diffusion length and coefficient, as well as light capture and charge separation efficiencies in nanoporous Mo-doped BiVO4 (Mo: BiVO4) photoanodes is obtained using photoelectrochemical techniques. Efficient water oxidation is achieved by doping with 1.8% Mo, resulting in a several-fold enhancement in photooxidation rate versus non-doped BiVO4. Two techniques are used to study the effect of Mo doping on the electron transport: (1) an analysis of the front/ back illumination ratio of incident photon-to-current efficiency and (2) intensity modulated photocurrent spectroscopy. These techniques show that Mo doping improves the diffusion coefficient four-fold and increases the diffusion length to ca. 300 nm (from 10 nm for the non-doped material), which is also the empirically-determined optimal Mo: BiVO4 film thickness for photoelectrolysis. These films are found to have a 90% charge separation efficiency and an 80% absorbed photon-to-current efficiency, excellent values for metal oxide photoabsorbers. Among the many oxygen evolution catalysts studied, surface modification with iron oxyhydroxide (FeOOH), a simple earth abundant catalyst, dramatically enhances the water oxidation performance of Mo: BiVO4 to an integrated IPCE of 2.41 mA cm(-2) and a photocurrent density of 2.77 mA cm(-2) in neutral phosphate at 1.23 V vs. RHE. C1 [Seabold, Jason A.; Zhu, Kai; Neale, Nathan R.] Natl Renewable Energy Lab, Chem & Mat Sci Ctr, Golden, CO 80401 USA. RP Neale, NR (reprint author), Natl Renewable Energy Lab, Chem & Mat Sci Ctr, Golden, CO 80401 USA. EM Nathan.Neale@nrel.gov FU Solar Photochemistry Program of the Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences of the U.S. Department of Energy [DE-AC36-08GO28308] FX The authors would like to thank Todd Deutsch (NREL) for assistance with the photoelectrochemical measurements. This work was funded by the Solar Photochemistry Program of the Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences of the U.S. Department of Energy through Grant DE-AC36-08GO28308 to NREL. NR 67 TC 54 Z9 54 U1 8 U2 122 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1463-9076 EI 1463-9084 J9 PHYS CHEM CHEM PHYS JI Phys. Chem. Chem. Phys. PY 2014 VL 16 IS 3 BP 1121 EP 1131 DI 10.1039/c3cp54356k PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 274ZE UT WOS:000328643900036 PM 24287501 ER PT J AU Talamo, A Gohar, Y Sadovich, S Kiyavitskaya, H Bournos, V Fokov, Y Routkovskaya, C AF Talamo, Alberto Gohar, Yousry Sadovich, S. Kiyavitskaya, H. Bournos, V. Fokov, Y. Routkovskaya, C. TI High enriched to low enriched fuel conversion in YALINA Booster facility SO PROGRESS IN NUCLEAR ENERGY LA English DT Article DE HEU; YALINA; Subcritical; Booster; ADS; MCNP ID LEU; HEU; CORE AB The YALINA Booster zero power facility is a subcritical assembly located in Minsk (Belarus). This assembly has the special feature of operating on fast and thermal neutron spectra in different zones. The fast zone of the assembly uses a lead matrix and uranium fuels with different enrichments: 90% and 36%, 36%, or 21%. The thermal zone of the assembly contains 10% enriched uranium fuel in polyethylene matrix. This study discusses the high enriched to low enriched fuel conversion. In order to increase the neutron multiplication of the assembly loaded with low (21%) enriched fuel in the fast zone, the number of fuel rods in the thermal zone cannot be augmented. Consequently, the effective multiplication factor of the configuration with 21% enriched uranium fuel in the fast zone has been enhanced by changing the position of the boron carbide and the natural uranium absorber rods, located in-between the fast and the thermal zones, to form a circular rather than a square arrangement. The MCNP computer simulation results obtained with the circular arrangement of the absorber rods are in good agreement with the experimental data. Published by Elsevier Ltd. C1 [Talamo, Alberto; Gohar, Yousry] Argonne Natl Lab, Argonne, IL 60439 USA. [Sadovich, S.; Kiyavitskaya, H.; Bournos, V.; Fokov, Y.; Routkovskaya, C.] Natl Acad Sci Belarus, Joint Inst Power & Nucl Res Sosny, Minsk 220109, Byelarus. RP Talamo, A (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM alby@anl.gov OI talamo, alberto/0000-0001-5685-0483 FU U.S. Department of Energy, National Nuclear Security Administration, Office of Global Nuclear Material Threat Reduction [NA213] FX This project is supported by the U.S. Department of Energy, National Nuclear Security Administration, Office of Global Nuclear Material Threat Reduction (NA213). NR 18 TC 0 Z9 0 U1 2 U2 5 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 PD JAN PY 2014 VL 70 BP 43 EP 53 DI 10.1016/j.pnucene.2013.07.010 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 275EU UT WOS:000328659900006 ER PT J AU Zhang, JS AF Zhang, Jinsuo TI Kinetic model for electrorefining, part I: Model development and validation SO PROGRESS IN NUCLEAR ENERGY LA English DT Article DE Pyroprocessing; Spent nuclear fuel; Modeling; Electrorefining ID NUCLEAR-FUEL; MOLTEN-SALT; URANIUM; PLUTONIUM; BEHAVIOR; SYSTEMS; CYCLES AB Electrorefining is the key process of the pryprocessing for treatment of spent nuclear fuels. In the present study, a kinetic model for electrorefining is developed. The model has the capability to predict the kinetic features of materials dissolution/deposition at anodes/cathodes of the electrorefiner and the evolution of the partial currents of the species involved, the potentials of the electrodes, and species concentrations in the molten salt. The model takes into account the changes of the surface areas and the volumes of the electrodes related to materials dissolution and deposition. The model is validated by compared with available experimental data. This article, focusing on the model development and validation, is Part I of the systemic study on development of the pyroprocessing model. Part II of this study will focus on the applications of the model. (C) 2013 Elsevier Ltd. All rights reserved. C1 [Zhang, Jinsuo] Ohio State Univ, Dept Mech & Aerosp Engn, Nucl Engn Program, Columbus, OH 43210 USA. [Zhang, Jinsuo] Los Alamos Natl Lab, Los Alamos, NM USA. RP Zhang, JS (reprint author), Ohio State Univ, Dept Mech & Aerosp Engn, Nucl Engn Program, Columbus, OH 43210 USA. EM zhang.3558@osu.edu RI Zhang, Jinsuo/H-4717-2012 OI Zhang, Jinsuo/0000-0002-3412-7769 NR 27 TC 11 Z9 11 U1 3 U2 13 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 PD JAN PY 2014 VL 70 BP 279 EP 286 DI 10.1016/j.pnucene.2013.03.001 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 275EU UT WOS:000328659900031 ER PT J AU Zhang, JS AF Zhang, Jinsuo TI Kinetic model for electrorefining, part II: Model applications and case studies SO PROGRESS IN NUCLEAR ENERGY LA English DT Article DE Fuel cycle; Pyrochemical processing; Modeling; Electrorefining ID KCL EUTECTIC MELTS; LIQUID CADMIUM; NUCLEAR-FUEL; URANIUM; THERMODYNAMICS; PLUTONIUM; ELECTRODE; BEHAVIOR; ALLOYS AB The model developed in Part I of the systematic study is applied to identify the kinetic features of materials flow in an electrorefinner. The most recent thermodynamic and electrochemical data reported are used in the present simulations. Both liquid and solid electrodes are considered. The main differences of the kinetics of materials dissolution/deposition between the liquid and solid electrode and the reasons for these differences are identified. The important factors that affect the evolution of electrorefining with operation are identified. (C) 2013 Elsevier Ltd. All rights reserved. C1 [Zhang, Jinsuo] Ohio State Univ, Dept Mech & Aerosp Engn, Nucl Engn Program, Columbus, OH 43210 USA. [Zhang, Jinsuo] Los Alamos Natl Lab, Los Alamos, NM USA. RP Zhang, JS (reprint author), Ohio State Univ, Dept Mech & Aerosp Engn, Nucl Engn Program, Columbus, OH 43210 USA. EM zhang.3558@osu.edu RI Zhang, Jinsuo/H-4717-2012 OI Zhang, Jinsuo/0000-0002-3412-7769 NR 20 TC 4 Z9 4 U1 3 U2 9 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 PD JAN PY 2014 VL 70 BP 287 EP 297 DI 10.1016/j.pnucene.2013.03.008 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 275EU UT WOS:000328659900032 ER PT J AU Sellaiyan, S Hughes, AE Smith, SV Uedono, A Sullivan, J Buckman, S AF Sellaiyan, Selvakumar Hughes, Anthony E. Smith, Suzanne V. Uedono, Akira Sullivan, James Buckman, Stephen TI Leaching properties of chromate-containing epoxy films using radiotracers, PALS and SEM SO PROGRESS IN ORGANIC COATINGS LA English DT Article DE Self-healing materials; Cr leaching; Cr-51; SEM; PALS ID ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY; ORGANIC COATINGS; POSITRON-ANNIHILATION; INHIBITED PRIMERS; GALVANIZED STEEL; DEPENDENCE; CORROSION; ALUMINUM AB Model chromate-containing epoxy primer (CEP) films were applied to aluminium alloy substrates using doctor blades. The effect of exposure to NaCl solution on the chromate-containing epoxy film was followed by monitoring the leaching behaviour of Cr. The continuous leaching of chromate inhibitor from the epoxy film is a self-healing characteristic that is designed to prevent corrosion of the aluminium alloy substrate. The CEP films were doped with Cr-51 chromate inhibitor (t(1/2) = 27.7 days), were exposed to NaCl solutions over time, and the Cr-51 gamma emission was used to monitor its release from the film into the aqueous solution. Pulsed beam positron lifetime spectroscopy and scanning electron microscopy (SEM) were used to probe structural changes that might transport properties of chromate species in the epoxy matrix. Positron Annihilation Lifetime Spectroscopy (PALS) was used to determine changes to free volumes at the nano scale in the films and SEM was used to ascertain the chromate distribution and structural scales at the micron level and above. Both PALS and SEM studies were preformed as a function of exposure time. It was found that a SrCrO4 depletion zone was formed at the surface as a result of the complete dissolution of the inhibitor particles, suggesting that transport of the Sr2+ and CrO42- might be through a network of channels created by the voids remaining in the epoxy matrix. Published by Elsevier B.V. C1 [Sellaiyan, Selvakumar; Smith, Suzanne V.; Sullivan, James; Buckman, Stephen] Australian Natl Univ, Res Sch Phys & Engn, Ctr Excellence Antimatter Matter Studies, Canberra, ACT 0200, Australia. [Sellaiyan, Selvakumar] Australian Nucl Sci & Technol Org, Ctr Excellence Antimatter Matter Studies, Kirrawee, NSW 2232, Australia. [Sellaiyan, Selvakumar] Univ Tsukuba, Tandem Accelerator Complex, Tsukuba, Ibaraki 3058577, Japan. [Hughes, Anthony E.] Commonwealth Sci & Ind Res Org, Div Mat Sci & Engn, Clayton, Vic 3169, Australia. [Smith, Suzanne V.] Brookhaven Natl Lab, Collider Accelerator Dept, Upton, NY 11973 USA. [Uedono, Akira] Univ Tsukuba, Inst Appl Phys, Tsukuba, Ibaraki 3058573, Japan. RP Smith, SV (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. EM Suzanne@bnl.gov RI Sullivan, James/F-3040-2011; Buckman, Stephen/B-4750-2009 OI Sullivan, James/0000-0003-4489-4926; FU Australian Research Council (ARC) research funds through ARC Centre of Excellence for Antimatter-Matter Studies FX The authors acknowledge the Australian Research Council (ARC) research funds through ARC Centre of Excellence for Antimatter-Matter Studies. The authors would also like to thanks Dr. A.M. Glenn for assistance with the scanning electron microscopy. NR 30 TC 9 Z9 9 U1 3 U2 21 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0300-9440 J9 PROG ORG COAT JI Prog. Org. Coat. PD JAN PY 2014 VL 77 IS 1 BP 257 EP 267 DI 10.1016/j.porgcoat.2013.09.014 PG 11 WC Chemistry, Applied; Materials Science, Coatings & Films SC Chemistry; Materials Science GA 272BE UT WOS:000328434500033 ER PT J AU Green, MA Emery, K Hishikawa, Y Warta, W Dunlop, ED AF Green, Martin A. Emery, Keith Hishikawa, Yoshihiro Warta, Wilhelm Dunlop, Ewan D. TI Solar cell efficiency tables (version 43) SO PROGRESS IN PHOTOVOLTAICS LA English DT Article DE solar cell efficiency; photovoltaic efficiency; energy conversion efficiency ID CONCENTRATOR; MULTICRYSTALLINE; STABILITY; MODULE 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 2013 are reviewed. Copyright (c) 2013 John Wiley & Sons, Ltd. C1 [Green, Martin A.] Univ New S Wales, Australian Ctr Adv Photovolta, Sydney, NSW 2052, Australia. [Emery, Keith] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Hishikawa, Yoshihiro] Natl Inst Adv Ind Sci & Technol, Res Ctr Photovolta Technol RCPT, Tsukuba, Ibaraki 3058568, Japan. [Warta, Wilhelm] Fraunhofer Inst Solar Energy Syst, Solar Cells Mat & Technol Dept, D-79110 Freiburg, Germany. [Dunlop, Ewan D.] Commiss European Communities, Joint Res Ctr, Inst Energy, Renewable Energy Unit, IT-21027 Ispra, VA, Italy. RP Green, MA (reprint author), Univ New S Wales, Sch Photovolta & Renewable Energy Engn, Sydney, NSW 2052, Australia. EM m.green@unsw.edu.au FU Australian Government through the Australian Renewable Energy Agency (ARENA) FX The Australian Centre for Advanced Photovoltaics commenced operation in February 2013 with support from the Australian Government through the Australian Renewable Energy Agency (ARENA). Responsibility for the views, information or advice expressed herein is not accepted by the Australian Government. NR 52 TC 389 Z9 394 U1 10 U2 342 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1062-7995 EI 1099-159X J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD JAN PY 2014 VL 22 IS 1 BP 1 EP 9 DI 10.1002/pip.2452 PG 9 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 269NR UT WOS:000328248500001 ER PT J AU Hsu, WC Repins, I Beall, C DeHart, C To, B Yang, WB Yang, Y Noufi, R AF Hsu, Wan-Ching Repins, Ingrid Beall, Carolyn DeHart, Clay To, Bobby Yang, Wenbing Yang, Yang Noufi, Rommel TI Growth mechanisms of co-evaporated kesterite: a comparison of Cu-rich and Zn-rich composition paths SO PROGRESS IN PHOTOVOLTAICS LA English DT Article DE CZTS; kesterite; thin film; solar cell; co-evaporation; earth-abundant ID COMPOSITION MONITORING METHOD; FILM SOLAR-CELLS; THIN-FILMS; EFFICIENCY; CU(IN,GA)SE-2; FABRICATION; PRECURSOR; SULFIDES; BINARY AB Earth abundant kesterite solar cells have achieved 7-10% cell efficiency mostly by processes that separate the film deposition and the annealing into two sequential steps. In contrast, co-evaporation onto a high-temperature substrate, demonstrating previous success in chalcopyrite (Cu(In,Ga)Se-2) solar cells, allows real-time composition control. Chalcopyrite research widely supports the model that Cu-rich growth conditions assist grain growth, and subsequently, the endpoint composition can be adjusted back to Cu-poor via monitoring the surface emissivity of the film. On the basis of the same intentions, the recent development of co-evaporated kesterite (Cu2ZnSnSe4) adapts the concept and achieves 9.2% efficiency. To understand the effect of growth strategies, this study examines the phase evolution, grain morphology, and device performance in Cu-rich growth and other strategies (Zn-rich and close-to-stoichiometric). By characterizing films obtained from interrupted depositions and also interpreting the variation in surface emission during growths, this study found a subtle hindrance in the reaction of CuxSey and ZnSe possibly caused by the volatile nature of SnSex. The hindrance explains why, distinctive from chalcopyrite, little difference in grain size is observed between kesterite films made by Cu-rich versus Zn-rich growth at these deposition rates. At last, a Zn-rich growth 9.1% device, certified by the National Renewable Energy Laboratory, is presented, which equals the performance of the previously-reported Cu-rich growth device. At the present stage, we believe the Cu-rich and Zn-rich growth share equal promise for the optimization of kesterite solar cells. Copyright (c) 2013 John Wiley & Sons, Ltd. C1 [Hsu, Wan-Ching; Yang, Wenbing; Yang, Yang] Univ Calif Los Angeles, Dept Mat Sci & Engn, Los Angeles, CA 90095 USA. [Repins, Ingrid; Beall, Carolyn; DeHart, Clay; To, Bobby; Noufi, Rommel] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Yang, Y (reprint author), Univ Calif Los Angeles, Dept Mat Sci & Engn, Los Angeles, CA 90095 USA. EM yangy@ucla.edu RI Yang, Yang/A-2944-2011 NR 30 TC 45 Z9 45 U1 3 U2 96 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1062-7995 EI 1099-159X J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD JAN PY 2014 VL 22 IS 1 BP 35 EP 43 DI 10.1002/pip.2296 PG 9 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 269NR UT WOS:000328248500005 ER PT J AU Paudel, NR Wieland, KA Young, M Asher, S Compaan, AD AF Paudel, Naba R. Wieland, Kristopher A. Young, Matthew Asher, Sally Compaan, Alvin D. TI Stability of sub-micron-thick CdTe solar cells SO PROGRESS IN PHOTOVOLTAICS LA English DT Article DE CdTe; solar cell; sputtering; ultrathin; stability; light soaking ID CU; TEMPERATURE; CONTACTS AB Sputtered CdS/CdTe cells with only 0.75 mu m of CdTe have reached AM1.5 efficiencies over 12.5%. But the use of very thin absorber layers of CdTe raises questions about the possible impact on long-term stability when the back contact is very close to the main junction. In this study, we have performed accelerated life testing (ALT) on unencapsulated CdTe dot cells with absorber thickness ranging from 0.7 to 2.1 mu m. After 900h of ALT at 85 degrees C under continuous one-sun illumination, with open circuit biasing and no encapsulation, we find that any decrease in stability as CdTe thickness decreases is within the similar to 10% statistical uncertainty shown by the sample sets of more than 20 cells each. Cells of all thicknesses exhibited some decrease in performance under these stress conditions, and open-circuit voltage appears to be the key factor in decreased efficiency. These changes in performance under ALT at 85 degrees C are found to be consistent with a projected field lifetime of about 40years in typical conditions. Secondary ion mass spectroscopy depth profiles of several elements including Cu showed no evidence of ALT-driven diffusion in these sputtered CdTe cells. Copyright (c) 2013 John Wiley & Sons, Ltd. C1 [Paudel, Naba R.; Wieland, Kristopher A.; Compaan, Alvin D.] Univ Toledo, Dept Phys & Astron, Toledo, OH 43606 USA. [Young, Matthew; Asher, Sally] NREL, Golden, CO 80401 USA. RP Paudel, NR (reprint author), Univ Toledo, Dept Phys & Astron, Res & Technol Complex 1,MS 218,2600 Dorr St, Toledo, OH 43607 USA. EM naba.paudel@utoledo.edu FU DOE University Photovoltaic Process and Product Development program; Ohio Department of Development's Third Frontier Program; National Science Foundation SBIR program through Xunlight 26 Solar FX This work has been supported by the DOE University Photovoltaic Process and Product Development program, the Ohio Department of Development's Third Frontier Program, and the National Science Foundation SBIR program through Xunlight 26 Solar. NR 22 TC 13 Z9 15 U1 2 U2 24 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1062-7995 EI 1099-159X J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD JAN PY 2014 VL 22 IS 1 BP 107 EP 114 DI 10.1002/pip.2396 PG 8 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 269NR UT WOS:000328248500014 ER PT J AU Boudko, SP Ishikawa, Y Nix, J Chapman, MS Bachinger, HP AF Boudko, Sergei P. Ishikawa, Yoshihiro Nix, Jay Chapman, Michael S. Baechinger, Hans Peter TI Structure of human peptidyl-prolyl cis-trans isomerase FKBP22 containing two EF-hand motifs SO PROTEIN SCIENCE LA English DT Article DE FKBP22; FKBP14; EF-hand motif; Ehlers-Danlos syndrome; peptidyl-prolyl cis-trans isomerase; crystal structure ID FK506-BINDING PROTEIN; RECEPTOR COMPLEX; FACTOR-VIII; OSTEOGENESIS IMPERFECTA; ENDOPLASMIC-RETICULUM; CRYSTAL-STRUCTURE; BINDING-PROTEIN; FACTOR-V; ER; DEFICIENCY AB The FK506-binding protein (FKBP) family consists of proteins with a variety of protein-protein interaction domains and versatile cellular functions. It is assumed that all members are peptidyl-prolyl cis-trans isomerases with the enzymatic function attributed to the FKBP domain. Six members of this family localize to the mammalian endoplasmic reticulum (ER). Four of them, FKBP22 (encoded by the FKBP14 gene), FKBP23 (FKBP7), FKBP60 (FKBP9), and FKBP65 (FKBP10), are unique among all FKBPs as they contain the EF-hand motifs. Little is known about the biological roles of these proteins, but emerging genetics studies are attracting great interest to the ER resident FKBPs, as mutations in genes encoding FKBP10 and FKBP14 were shown to cause a variety of matrix disorders. Although the structural organization of the FKBP-type domain as well as of the EF-hand motif has been known for a while, it is difficult to conclude how these structures are combined and how it affects the protein functionality. We have determined a unique 1.9 angstrom resolution crystal structure for human FKBP22, which can serve as a prototype for other EF hand-containing FKBPs. The EF-hand motifs of two FKBP22 molecules form a dimeric complex with an elongated and predominantly hydrophobic cavity that can potentially be occupied by an aliphatic ligand. The FKBP-type domains are separated by a cleft and their putative active sites can catalyze isomerazation of two bonds within a polypeptide chain in extended conformation. These structural results are of prime interest for understanding biological functions of ER resident FKBPs containing EF-hand motifs. Interactive Figure 1, Interactive Figure 2 | PDB Code(s): 4MSP C1 [Boudko, Sergei P.; Ishikawa, Yoshihiro; Baechinger, Hans Peter] Shriners Hosp Children, Res Dept, Portland, OR 97239 USA. [Boudko, Sergei P.; Ishikawa, Yoshihiro; Chapman, Michael S.; Baechinger, Hans Peter] Oregon Hlth & Sci Univ, Dept Biochem & Mol Biol, Portland, OR 97239 USA. [Nix, Jay] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Mol Biol Consortium, Adv Light Source Beamline, Berkeley, CA 94720 USA. RP Bachinger, HP (reprint author), Shriners Hosp Children, Res Dept, 3101 SW Sam Jackson Pk Rd, Portland, OR 97239 USA. EM hpb@shcc.org FU Shriners Hospital for Children FX Grant sponsors: Shriners Hospital for Children (to H.P.B.). NR 38 TC 8 Z9 8 U1 2 U2 10 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0961-8368 EI 1469-896X J9 PROTEIN SCI JI Protein Sci. PD JAN PY 2014 VL 23 IS 1 BP 67 EP 75 DI 10.1002/pro.2391 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 273WI UT WOS:000328566600006 PM 24272907 ER PT J AU Shulga, YM Baskakov, SA Knerelman, EI Davidova, GI Badamshina, ER Shulga, NY Skryleva, EA Agapov, AL Voylov, DN Sokolov, AP Martynenko, VM AF Shulga, Y. M. Baskakov, S. A. Knerelman, E. I. Davidova, G. I. Badamshina, E. R. Shulga, N. Yu. Skryleva, E. A. Agapov, A. L. Voylov, D. N. Sokolov, A. P. Martynenko, V. M. TI Carbon nanomaterial produced by microwave exfoliation of graphite oxide: new insights SO RSC ADVANCES LA English DT Article ID HETEROJUNCTION PHOTOVOLTAIC DEVICES; ELECTRICAL-CONDUCTIVITY; GRAPHENE NANOSHEETS; REDUCTION; FUNCTIONALIZATION; DEPOSITION; CONVERSION; COMPOSITE; SHEETS AB We present detailed characterization of graphene-like material obtained through microwave stimulated exfoliation of graphite oxide (GO). Properties of this material were studied by multiple techniques including, among others, X-ray photoelectron spectroscopy, mass-spectroscopy, infrared and Raman spectroscopy, scanning electron microscopy and broadband dielectric spectroscopy. Specific surface area and volume of microwave exfoliated graphite oxide reached 600 m(2) g(-1) and 6 cm(3) g(-1), respectively. It is shown that during such an explosive reduction process the sample emits CO2, CO and H2O and, in some cases, SO2 gases. The resulting reduced material exhibits IR spectra similar to that of graphite and a dc-conductivity of 0.12 S cm(-1). C1 [Shulga, Y. M.; Baskakov, S. A.; Knerelman, E. I.; Davidova, G. I.; Badamshina, E. R.; Voylov, D. N.; Martynenko, V. M.] Inst Problems Chem Phys RAS, Chernogolovka 142432, Moscow Region, Russia. [Shulga, N. Yu.; Skryleva, E. A.] Natl Univ Sci & Technol MISiS, Moscow 117936, Russia. [Agapov, A. L.; Voylov, D. N.; Sokolov, A. P.] Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. [Sokolov, A. P.] Oak Ridge Natl Lab, Div Chem Sci, Knoxville, TN 37996 USA. RP Voylov, DN (reprint author), Inst Problems Chem Phys RAS, Chernogolovka 142432, Moscow Region, Russia. EM dvoylov@utk.edu RI Voylov, Dmitry/H-4059-2013; Shulga, Natalia/A-5019-2014; Badamshina, Elmira/I-3964-2016 OI Voylov, Dmitry/0000-0001-5552-6024; Shulga, Natalia/0000-0001-7514-9094; Badamshina, Elmira/0000-0003-2382-3387 FU RFBR [12-03-00919-a, 12-03-00615]; Division of Materials Science and Engineering, U.S. Department of Energy, Office of Basic Energy Sciences FX This work was supported by RFBR (#12-03-00919-a and #12-03-00615). US team acknowledges partial financial support from the Division of Materials Science and Engineering, U. S. Department of Energy, Office of Basic Energy Sciences. These studies were performed in the framework of the US-Russia agreement on Collaboration in Clean Energy Technologies. NR 37 TC 14 Z9 14 U1 1 U2 49 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 2046-2069 J9 RSC ADV JI RSC Adv. PY 2014 VL 4 IS 2 BP 587 EP 592 DI 10.1039/c3ra43612h PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA 264AQ UT WOS:000327849700012 ER PT J AU Newman, GA AF Newman, Gregory A. TI A Review of High-Performance Computational Strategies for Modeling and Imaging of Electromagnetic Induction Data SO SURVEYS IN GEOPHYSICS LA English DT Review DE Three-dimensional electromagnetic modeling and inversion; Magnetotelluric soundings; Electromagnetic induction; High-performance computing; Parallel solvers; Resistivity imaging for the Earth ID MASSIVELY-PARALLEL COMPUTERS; FINITE-ELEMENT SIMULATION; LINEAR-SYSTEMS; ELECTRICAL-CONDUCTIVITY; MAGNETOTELLURIC DATA; CONJUGATE GRADIENTS; JOINT INVERSION; CSEM DATA; FIELDS; SOLVER AB Many geoscientific applications exploit electrostatic and electromagnetic fields to interrogate and map subsurface electrical resistivity-an important geophysical attribute for characterizing mineral, energy, and water resources. In complex three-dimensional geologies, where many of these resources remain to be found, resistivity mapping requires large-scale modeling and imaging capabilities, as well as the ability to treat significant data volumes, which can easily overwhelm single-core and modest multicore computing hardware. To treat such problems requires large-scale parallel computational resources, necessary for reducing the time to solution to a time frame acceptable to the exploration process. The recognition that significant parallel computing processes must be brought to bear on these problems gives rise to choices that must be made in parallel computing hardware and software. In this review, some of these choices are presented, along with the resulting trade-offs. We also discuss future trends in high-performance computing and the anticipated impact on electromagnetic (EM) geophysics. Topics discussed in this review article include a survey of parallel computing platforms, graphics processing units to multicore CPUs with a fast interconnect, along with effective parallel solvers and associated solver libraries effective for inductive EM modeling and imaging. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Newman, GA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, MS 90-1116, Berkeley, CA 94720 USA. EM ganewman@lbl.gov RI Newman, Gregory/G-2813-2015 FU U.S. Department of Energy Office of Science [DE-AC02-05CH11231] FX I wish to thank Yasuo Ogawa, Graham Heinson, and other members of the 21st EM Workshop Program Committee for the invitation and opportunity to write this review article. Input from the two referees, Klaus Spitzer and Chester Weiss, also improved the content of the review. Finally, I also wish to acknowledge my employer, Lawrence Berkeley Laboratory, and the U.S. Department of Energy Office of Science for funding, under contract number DE-AC02-05CH11231. NR 91 TC 16 Z9 16 U1 6 U2 37 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0169-3298 EI 1573-0956 J9 SURV GEOPHYS JI Surv. Geophys. PD JAN PY 2014 VL 35 IS 1 SI SI BP 85 EP 100 DI 10.1007/s10712-013-9260-0 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 278AM UT WOS:000328860400004 ER PT J AU Kaspar, TC Bowden, ME Wang, CM Shutthanandan, V Manandhar, S van Ginhoven, RM Wirth, BD Kurtz, RJ AF Kaspar, Tiffany C. Bowden, Mark E. Wang, Chongmin Shutthanandan, V. Manandhar, Sandeep van Ginhoven, Renee M. Wirth, Brian D. Kurtz, Richard J. TI Defect structure of epitaxial CrxV1-x thin films on MgO(001) SO THIN SOLID FILMS LA English DT Article DE Epitaxy; CrxV1- (x); Alloys; Misfit dislocations; Rutherford backscattering spectrometry; Channeling; X-ray diffraction; Transmission electron microscopy ID THERMAL-EXPANSION; CHROMIUM-ALLOYS; MGO(100) SURFACES; QUANTUM DOTS; STRAIN; MGO; CR; ANTIFERROMAGNETISM; MULTILAYERS; VANADIUM AB Epitaxial thin films of CrxV1 - x over the entire composition range were deposited on MgO(001) by molecular beam epitaxy. The films exhibited the expected 45 degrees in-plane rotation with no evidence of phase segregation or spinodal decomposition. Pure Cr, with the largest lattice mismatch to MgO, exhibited full relaxation and cubic lattice parameters. As the lattice mismatch decreased with alloy composition, residual epitaxial strain was observed. For 0.2 <= x <= 0.4 the films were coherently strained to the substrate with associated tetragonal distortion; near the lattice-matched composition of x = 0.33, the films exhibited strain-free pseudomorphic matching to MgO. Unusually, films on the Cr-rich side of the lattice-matched composition exhibited more in-plane compression than expected from the bulk lattice parameters; this result was confirmed with both x-ray diffraction and Rutherford backscattering spectrometry channeling measurements. The effect of thermal expansion mismatch on strain in the heterostructure was estimated. High resolution transmission electronmicroscopy was utilized to characterize the misfit dislocation network present at the film/MgO interface. Dislocations were found to be present with a non-uniform distribution, which is attributed to the Volmer-Weber growth mode of the films. The CrxV1 - x/MgO(001) system can serve as a model system to study the fundamentals of defect formation in bcc films. (C) 2013 Elsevier B. V. All rights reserved. C1 [Kaspar, Tiffany C.] Pacific NW Natl Lab, Fundamental & Computat Sci Directorate, Richland, WA 99352 USA. [Bowden, Mark E.; Wang, Chongmin; Shutthanandan, V.; Manandhar, Sandeep] Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. [van Ginhoven, Renee M.; Kurtz, Richard J.] Pacific NW Natl Lab, Energy & Environm Directorate, Richland, WA 99352 USA. [Wirth, Brian D.] Univ Tennessee, Dept Nucl Engn, Knoxville, TN 37996 USA. RP Kaspar, TC (reprint author), Pacific NW Natl Lab, Fundamental & Computat Sci Directorate, POB 999, Richland, WA 99352 USA. EM tiffany.kaspar@pnnl.gov RI Wirth, Brian/O-4878-2015; OI Wirth, Brian/0000-0002-0395-0285; Manandhar, Sandeep/0000-0001-8613-5317 FU US Department of Energy (DOE), Office of Basic Energy Sciences, Division of Materials Sciences and Engineering; US DOE Office of Biological and Environmental Research FX This work was supported by the US Department of Energy (DOE), Office of Basic Energy Sciences, Division of Materials Sciences and Engineering. The experiments were carried out at the Environmental Molecular Sciences Laboratory (EMSL), a National Scientific User Facility located at Pacific Northwest National Laboratory (PNNL) and supported by the US DOE Office of Biological and Environmental Research. PNNL is a multiprogram national laboratory operated for DOE by Battelle. NR 44 TC 4 Z9 4 U1 2 U2 18 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JAN 1 PY 2014 VL 550 BP 1 EP 9 DI 10.1016/j.tsf.2013.09.067 PG 9 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 272YP UT WOS:000328499700001 ER PT J AU Lee, BG Li, S von Gastrow, G Yli-Koski, M Savin, H Malinen, V Skarp, J Choi, S Branz, HM AF Lee, Benjamin G. Li, Shuo von Gastrow, Guillaume Yli-Koski, Marko Savin, Hele Malinen, Ville Skarp, Jarmo Choi, Sukgeun Branz, Howard M. TI Excellent passivation and low reflectivity with atomic layer deposited bilayer coatings for n-type silicon solar cells SO THIN SOLID FILMS LA English DT Article DE Passivation; Anti-reflection; n-Type silicon; Minority carrier lifetime; Atomic layer deposition AB Bilayer coatings deposited by atomic layer deposition are shown to simultaneously achieve excellent passivation and low reflectivity, suitable for application on the front side of high-performance n-type Si solar cells. We designed and fabricated bilayer coatings of 10 nm Al2O3 followed by a top layer of either 50.5 nm TiO2 or 52.5 nm ZnS. The bilayers have absolute reflectivity nearly 2% lower than state-of-the-art silicon nitride antireflection coatings. They passivate both highly doped p-type emitter surfaces and also low-doped p-type Si. For a B-doped emitter with sheet resistance of 159 Omega/sq on n-type Si, the Al2O3/TiO2 coating has a low emitter saturation current density J(0,e) of 38 fA/cm(2), while Al2O3/ZnS has 52 fA/cm(2). On low-doped p-type Si wafers, passivation using either coating resulted in minority carrier lifetimes above 1 ms, corresponding to surface recombination velocities below 10 cm/s. (C) 2013 Elsevier B.V. All rights reserved. C1 [Lee, Benjamin G.; Choi, Sukgeun; Branz, Howard M.] Natl Renewable Energy Lab, Natl Ctr Photovolta, Golden, CO 80401 USA. [Li, Shuo; von Gastrow, Guillaume; Yli-Koski, Marko; Savin, Hele] Aalto Univ, Dept Micro & Nanosci, Espoo 02150, Finland. [Li, Shuo; Malinen, Ville; Skarp, Jarmo] Beneq Oy, Vantaa 01510, Finland. RP Lee, BG (reprint author), Natl Renewable Energy Lab, Natl Ctr Photovolta, Golden, CO 80401 USA. EM benjamin.lee@nrel.gov RI Savin, Hele/E-5155-2012; Choi, Sukgeun/J-2345-2014 OI Savin, Hele/0000-0003-3946-7727; FU U.S. Department of Energy [DE-AC36-08GO28308]; Aalto University FX The authors gratefully acknowledge P. Stradins for discussions, H.-C. Yuan and Y. Ai for help in sample preparation at NREL, and Milja Makela for processing at Beneq. NREL work is supported by the U.S. Department of Energy under Contract DE-AC36-08GO28308. Part of the research was performed at the Micronova Nanofabrication Centre supported by Aalto University. NR 15 TC 6 Z9 6 U1 2 U2 37 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JAN 1 PY 2014 VL 550 BP 541 EP 544 DI 10.1016/j.tsf.2013.10.166 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 272YP UT WOS:000328499700082 ER PT J AU Chylek, LA Harris, LA Tung, CS Faeder, JR Lopez, CF Hlavacek, WS AF Chylek, Lily A. Harris, Leonard A. Tung, Chang-Shung Faeder, James R. Lopez, Carlos F. Hlavacek, William S. TI Rule-based modeling: a computational approach for studying biomolecular site dynamics in cell signaling systems SO WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE LA English DT Article ID GROWTH-FACTOR RECEPTOR; PROTEIN-PROTEIN INTERACTIONS; BIOCHEMICAL REACTION NETWORKS; QUANTITATIVE KINETIC-MODELS; FC-EPSILON-RI; EGF-RECEPTOR; TRANSDUCTION NETWORKS; STOCHASTIC SIMULATION; IN-VIVO; B-CELL AB Rule-based modeling was developed to address the limitations of traditional approaches for modeling chemical kinetics in cell signaling systems. These systems consist of multiple interacting biomolecules (e.g., proteins), which themselves consist of multiple parts (e.g., domains, linear motifs, and sites of phosphorylation). Consequently, biomolecules that mediate information processing generally have the potential to interact in multiple ways, with the number of possible complexes and posttranslational modification states tending to grow exponentially with the number of binary interactions considered. As a result, only large reaction networks capture all possible consequences of the molecular interactions that occur in a cell signaling system, which is problematic because traditional modeling approaches for chemical kinetics (e.g., ordinary differential equations) require explicit network specification. This problem is circumvented through representation of interactions in terms of local rules. With this approach, network specification is implicit and model specification is concise. Concise representation results in a coarse graining of chemical kinetics, which is introduced because all reactions implied by a rule inherit the rate law associated with that rule. Coarse graining can be appropriate if interactions are modular, and the coarseness of a model can be adjusted as needed. Rules can be specified using specialized model-specification languages, and recently developed tools designed for specification of rule-based models allow one to leverage powerful software engineering capabilities. A rule-based model comprises a set of rules, which can be processed by general-purpose simulation and analysis tools to achieve different objectives (e.g., to perform either a deterministic or stochastic simulation). (C) 2013 Wiley Periodicals, Inc. C1 [Chylek, Lily A.] Cornell Univ, Dept Chem & Chem Biol, Ithaca, NY USA. [Harris, Leonard A.; Faeder, James R.] Univ Pittsburgh, Sch Med, Dept Computat & Syst Biol, Pittsburgh, PA USA. [Tung, Chang-Shung] Los Alamos Natl Lab, Div Theoret, Theoret Biol & Biophys Grp, Los Alamos, NM USA. [Lopez, Carlos F.] Vanderbilt Univ, Sch Med, Dept Canc Biol, Nashville, TN 37212 USA. [Lopez, Carlos F.] Vanderbilt Univ, Sch Med, Ctr Quantitat Sci, Nashville, TN 37212 USA. [Hlavacek, William S.] Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. [Hlavacek, William S.] Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Hlavacek, WS (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM wish@lanl.gov OI Lopez, Carlos/0000-0003-3668-7468; Hlavacek, William/0000-0003-4383-8711; Harris, Leonard/0000-0003-2112-6940 FU NIH/NIGMS [P50GM085273, P41GM103712]; NIH/NCI [K22CA151918]; NSF Expeditions in Computing Grant [0926181]; US/UK Collaboration Development Award; Los Alamos Center for Nonlinear Studies; Laboratory-directed Research and Development Program at Los Alamos National Laboratory; US Department of Energy [DE-AC52 06NA25396] FX We acknowledge funding from NIH/NIGMS grants P50GM085273 (WSH and CT) and P41GM103712 (LAH and JRF); NIH/NCI grant K22CA151918 (CFL); an NSF Expeditions in Computing Grant (Award 0926181, LAH and JRF); a US/UK Collaboration Development Award (CFL); and the Los Alamos Center for Nonlinear Studies (LAC), which is supported by the Laboratory-directed Research and Development Program at Los Alamos National Laboratory and US Department of Energy contract DE-AC52 06NA25396. NR 219 TC 21 Z9 22 U1 0 U2 28 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1939-5094 EI 1939-005X J9 WIRES SYST BIOL MED JI Wiley Interdiscip. Rev.-Syst. Biol PD JAN PY 2014 VL 6 IS 1 BP 13 EP 36 DI 10.1002/wsbm.1245 PG 24 WC Medicine, Research & Experimental SC Research & Experimental Medicine GA 273TF UT WOS:000328558500002 PM 24123887 ER PT J AU Liu, W Zheng, F Li, J Cooper, A AF Liu, Wei Zheng, Feng (Richard) Li, Joanne Cooper, Alan TI An Ionic Liquid Reaction and Separation Process for Production of Hydroxymethylfurfural from Sugars SO AICHE JOURNAL LA English DT Article DE ionic liquid; hydroxymethylfurfural; plastics; sugar; biomass; adsorption; reaction; separation; membrane; adsorbent ID CATALYTIC PROCESSES; CONVERSION; FRUCTOSE AB Hydroxymethylfurfural (HMF) is viewed as a potential platform material to make a variety of chemicals and products out of renewable resources. In this work, a complete ionic liquid reaction and separation process is presented for nearly stoichiometric conversion of fructose into HMF. The silicalite adsorbent material is demonstrated for separation of 99% pure HMF out of ionic liquid reaction mixtures through a packed column and for recovery of the unconverted sugars and reaction intermediates along with the ionic liquid. Membrane-coated silicalite particles are prepared and studied for a practical adsorption process with separation performances comparable to or better than the powder material. It is discovered that nearly all the fresh fructose feed could be converted into HMF with the recycled ionic liquid under suitable reaction conditions. These research results lead to a new HMF production process much simpler than the current paraxylene manufacturing process from petroleum oil. (c) 2013 American Institute of Chemical Engineers AIChE J, 60: 300-314, 2014 C1 [Liu, Wei; Zheng, Feng (Richard); Li, Joanne; Cooper, Alan] Pacific NW Natl Lab, Energy & Environm Directorate, Richland, WA 99352 USA. RP Liu, W (reprint author), Pacific NW Natl Lab, Energy & Environm Directorate, Richland, WA 99352 USA. EM wei.liu@pnnl.gov RI Zheng, Feng/C-7678-2009 OI Zheng, Feng/0000-0002-5427-1303 FU USDA [68-3A75-7-613] FX This contribution was identified by Professor Suojiang Zhang (Institute of Process Engineering, Chinese Academy of Sciences) as a "Best Presentation" in the session "International Forum on Energy Sustainability" of the 2012 AIChE Annual Meeting in Pittsburgh, PA. The authors would like to thank their colleagues, Dr. Tony Rao for adsorbent preparation, Dr. Abhijeet Karkamkar for conducting the TGA tests, and Mrs. Shari Li for BET surface area measurements. They also would like to thank Dr. John Holladay at PNNL, and Timothy Brandvold and Sharry Lynch at UOP for starting this project. This project was funded by USDA under Grant Agreement #68-3A75-7-613. NR 26 TC 3 Z9 3 U1 9 U2 54 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0001-1541 EI 1547-5905 J9 AICHE J JI AICHE J. PD JAN PY 2014 VL 60 IS 1 BP 300 EP 314 DI 10.1002/aic.14289 PG 15 WC Engineering, Chemical SC Engineering GA 265CI UT WOS:000327926900023 ER PT J AU Lv, YQ Lin, ZX Tan, TW Svec, F AF Lv, Yongqin Lin, Zhixing Tan, Tianwei Svec, Frantisek TI Preparation of Reusable Bioreactors Using Reversible Immobilization of Enzyme on Monolithic Porous Polymer Support With Attached Gold Nanoparticles SO BIOTECHNOLOGY AND BIOENGINEERING LA English DT Article DE porous polymer; monolith; immobilized enzyme bioreactor; gold nanoparticles; lipase; biodiesel ID PERFORMANCE LIQUID-CHROMATOGRAPHY; PORCINE PANCREATIC LIPASE; LESS COMMON APPLICATIONS; ACID METHYL-ESTERS; CAPILLARY COLUMNS; AFFINITY-CHROMATOGRAPHY; BIODIESEL PRODUCTION; MASS-SPECTROMETRY; REACTOR; TRYPSIN AB Porcine lipase has been reversibly immobilized on a monolithic polymer support containing thiol functionalities prepared within confines of a fused silica capillary and functionalized with gold nanoparticles. Use of gold nanoparticles enabled rejuvenation of the activity of the deactivated reactor simply by stripping the inactive enzyme from the nanoparticles using 2-mercaptoethanol and subsequent immobilization of fresh lipase. This flow through enzymatic reactor was then used to catalyze the hydrolysis of glyceryl tributyrate (tributyrin). The highest activity was found within a temperature range of 37-40 degrees C. The reaction kinetics is characterized by Michaelis-Menten constant, K-m=10.9mmol/L, and maximum reaction rate, V-max=5.0mmol/Lmin. The maximum reaction rate for the immobilized enzyme is 1,000 times faster compared to lipase in solution. The fast reaction rate enabled to achieve 86.7% conversion of tributyrin in mere 2.5min and an almost complete conversion in 10min. The reactor lost only less than 10% of its activity even after continuous pumping through it a solution of substrate equaling 1,760 reactor volumes. Finally, potential application of this enzymatic reactor was demonstrated with the transesterification of triacylglycerides from kitchen oil to fatty acid methyl esters thus demonstrating the ability of the reactor to produce biodiesel. Biotechnol. Bioeng. 2014;111: 50-58. (c) 2013 Wiley Periodicals, Inc. C1 [Lv, Yongqin; Tan, Tianwei] Beijing Univ Chem Technol, Coll Life Sci & Technol, Beijing Key Lab Bioproc, Beijing 100029, Peoples R China. [Lv, Yongqin] Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. [Lin, Zhixing; Svec, Frantisek] EO Lawrence Berkeley Natl Lab, Mol Foundry, Berkeley, CA 94720 USA. RP Svec, F (reprint author), EO Lawrence Berkeley Natl Lab, Mol Foundry, Berkeley, CA 94720 USA. EM fsvec@lbl.gov RI Foundry, Molecular/G-9968-2014 FU NIH [GM48364, 2013CB733600, 2007CB714300, 2011CB710805, 2007CB714302-2]; National Natural Science Foundation of China [2006AA020102, 2007AA10040] FX Contract grant sponsor: NIH; Contract grant number: GM48364; Contract grant numbers: 973 programs (2013CB733600, 2007CB714300, 2011CB710805, and 2007CB714302-2); Contract grant sponsor: National Natural Science Foundation of China; Contract grant number: 863 programs (2006AA020102 and 2007AA10040); Contract grant sponsor: Beijing Educational Committee Joint Construction NR 55 TC 20 Z9 20 U1 6 U2 128 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0006-3592 EI 1097-0290 J9 BIOTECHNOL BIOENG JI Biotechnol. Bioeng. PD JAN PY 2014 VL 111 IS 1 BP 50 EP 58 DI 10.1002/bit.25005 PG 9 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA 265VB UT WOS:000327979100005 PM 23860941 ER PT J AU Dijkstra, HA Wubs, FW Cliffe, AK Doedel, E Dragomirescu, IF Eckhardt, B Gelfgat, AY Hazel, AL Lucarini, V Salinger, AG Phipps, ET Sanchez-Umbria, J Schuttelaars, H Tuckerman, LS Thiele, U AF Dijkstra, Henk A. Wubs, Fred W. Cliffe, Andrew K. Doedel, Eusebius Dragomirescu, Ioana F. Eckhardt, Bruno Gelfgat, Alexander Yu. Hazel, Andrew L. Lucarini, Valerio Salinger, Andy G. Phipps, Erik T. Sanchez-Umbria, Juan Schuttelaars, Henk Tuckerman, Laurette S. Thiele, Uwe TI Numerical Bifurcation Methods and their Application to Fluid Dynamics: Analysis beyond Simulation SO COMMUNICATIONS IN COMPUTATIONAL PHYSICS LA English DT Review DE Numerical bifurcation analysis; transitions in fluid flows; high-dimensional dynamical systems ID THIN LIQUID-FILMS; TRAVELING-WAVE SOLUTIONS; PLANE COUETTE-FLOW; EXACT COHERENT STRUCTURES; NAVIER-STOKES FLOWS; PIPE-FLOW; OCEAN CIRCULATION; THERMOSOLUTAL CONVECTION; RIGHTMOST EIGENVALUES; MARANGONI CONVECTION AB We provide an overview of current techniques and typical applications of numerical bifurcation analysis in fluid dynamical problems. Many of these problems are characterized by high-dimensional dynamical systems which undergo transitions as parameters are changed. The computation of the critical conditions associated with these transitions, popularly referred to as 'tipping points', is important for understanding the transition mechanisms. We describe the two basic classes of methods of numerical bifurcation analysis, which differ in the explicit or implicit use of the Jacobian matrix of the dynamical system. The numerical challenges involved in both methods are mentioned and possible solutions to current bottlenecks are given. To demonstrate that numerical bifurcation techniques are not restricted to relatively low-dimensional dynamical systems, we provide several examples of the application of the modern techniques to a diverse set of fluid mechanical problems. C1 [Dijkstra, Henk A.] Univ Utrecht, Inst Marine & Atmospher Res Utrecht, NL-3508 TC Utrecht, Netherlands. [Wubs, Fred W.] Univ Groningen, Dept Math & Comp Sci, Groningen, Netherlands. [Cliffe, Andrew K.] Univ Nottingham, Sch Math Sci, Nottingham NG7 2RD, England. [Doedel, Eusebius] Concordia Univ, Dept Comp Sci, Montreal, PQ H3G 1M8, Canada. [Dragomirescu, Ioana F.] Univ Politehn Timisoara, Natl Ctr Engn Syst Complex Fluids, Timisoara, Romania. [Eckhardt, Bruno] Univ Marburg, Fachbereich Phys, D-35032 Marburg, Germany. [Gelfgat, Alexander Yu.] Tel Aviv Univ, Fac Engn, Sch Mech Engn, IL-69978 Tel Aviv, Israel. [Hazel, Andrew L.] Univ Manchester, Sch Math, Manchester, Lancs, England. [Lucarini, Valerio] Univ Hamburg, Inst Meteorol, Hamburg, Germany. [Lucarini, Valerio] Univ Reading, Dept Math & Stat, Reading, Berks, England. [Salinger, Andy G.; Phipps, Erik T.] Sandia Natl Labs, Albuquerque, NM 87185 USA. [Sanchez-Umbria, Juan] Univ Politecn Cataluna, Dept Fis Aplicada, Barcelona, Spain. [Schuttelaars, Henk] Delft Univ Technol, Dept Appl Math Anal, Delft, Netherlands. [Tuckerman, Laurette S.] PMMH ESPCI, Paris, France. [Thiele, Uwe] Univ Loughborough, Dept Math Sci, Loughborough, Leics, England. RP Dijkstra, HA (reprint author), Univ Utrecht, Inst Marine & Atmospher Res Utrecht, NL-3508 TC Utrecht, Netherlands. EM H.A.Dijkstra@uu.nl RI Eckhardt, Bruno/D-5948-2012; Sanchez Umbria, Juan/J-7234-2012; Dijkstra , Henk /H-2559-2016; thiele, uwe/B-6236-2008; OI Eckhardt, Bruno/0000-0003-4050-3254; Sanchez Umbria, Juan/0000-0002-3271-8012; thiele, uwe/0000-0001-7989-9271; Hazel, Andrew/0000-0003-1130-0554; Lucarini, Valerio/0000-0001-9392-1471 FU Netherlands Organization of Scientific Research (NWO) through the NWO-COMPLEXITY project PreKurs; Romanian National Authority for Scientific Research, CNCS-UEFISCDI [PN-II-RU-PD-2011-3-0153, 31/5.10.2011]; United States Department of Energy's National Nuclear Security Administration [DE-AC04-94AL85000]; EU [257106]; [MTM2010-16930]; [2009-SGR-67] FX This review was initiated during a workshop on "Tipping points in Complex Flows" during October 31-November 4, 2011. We thank the staff of the Lorentz Center in Leiden, the Netherlands, for making this workshop such a pleasant and interesting event. The workshop and the work of F. W. Wubs and H. A. Dijkstra was partially sponsored by the Netherlands Organization of Scientific Research (NWO) through the NWO-COMPLEXITY project PreKurs. The participation of F. I. Dragomirescu to the workshop was partially supported by a Grant of the Romanian National Authority for Scientific Research, CNCS-UEFISCDI, project number PN-II-RU-PD-2011-3-0153, 31/5.10.2011. Sandia National Laboratory is a multiprogram laboratory 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. The work of J. Sanchez-Umbria was supported by projects MTM2010-16930 and 2009-SGR-67. Valerio Lucarini acknowledges the financial support received from the EU through the FP7/2007-2013/ERC Grant agreement No. 257106, project Thermodynamics of the Climate System-NAMASTE. NR 141 TC 31 Z9 31 U1 2 U2 30 PU GLOBAL SCIENCE PRESS PI WANCHAI PA ROOM 3208, CENTRAL PLAZA, 18 HARBOUR RD, WANCHAI, HONG KONG 00000, PEOPLES R CHINA SN 1815-2406 EI 1991-7120 J9 COMMUN COMPUT PHYS JI Commun. Comput. Phys. PD JAN PY 2014 VL 15 IS 1 BP 1 EP 45 DI 10.4208/cicp.240912.180613a PG 45 WC Physics, Mathematical SC Physics GA 269YE UT WOS:000328279800001 ER PT J AU Lin, G Bao, J Xu, ZJ Tartakovsky, AM Henager, CH AF Lin, Guang Bao, Jie Xu, Zhijie Tartakovsky, Alexandre M. Henager, Charles H., Jr. TI A Phase-Field Model Coupled with Lattice Kinetics Solver for Modeling Crystal Growth in Furnaces SO COMMUNICATIONS IN COMPUTATIONAL PHYSICS LA English DT Article DE Phase-field; crystal growth; diffusion; convection; lattice kinetics; modeling ID VERTICAL BRIDGMAN GROWTH; CADMIUM ZINC TELLURIDE; SIGE SINGLE-CRYSTALS; BOLTZMANN-EQUATION; THERMAL-CONDUCTIVITY; SIMULATION; SEGREGATION; DIFFUSION; FLUID; FLOWS AB In this study, we present a new numerical model for crystal growth in a vertical solidification system. This model takes into account the buoyancy induced convective flow and its effect on the crystal growth process. The evolution of the crystal growth interface is simulated using the phase-field method. A semi-implicit lattice kinetics solver based on the Boltzmann equation is employed to model the unsteady incompressible flow. This model is used to investigate the effect of furnace operational conditions on crystal growth interface profiles and growth velocities. For a simple case of macroscopic radial growth, the phase-field model is validated against an analytical solution. The numerical simulations reveal that for a certain set of temperature boundary conditions, the heat transport in the melt near the phase interface is diffusion dominant and advection is suppressed. C1 [Lin, Guang; Xu, Zhijie; Tartakovsky, Alexandre M.] Pacific NW Natl Lab, Computat Math Grp, Richland, WA 99352 USA. [Bao, Jie] Pacific NW Natl Lab, Fluid & Computat Engn Grp, Richland, WA 99352 USA. [Henager, Charles H., Jr.] Pacific NW Natl Lab, Engn Mech & Struct Mat Grp, Richland, WA 99352 USA. RP Lin, G (reprint author), Pacific NW Natl Lab, Computat Math Grp, Richland, WA 99352 USA. EM guang.lin@pnnl.gov; jie.bao@pnnl.gov; zhijie.xu@pnnl.gov; alexandre.tartakovsky@pnnl.gov; chuck.henager@pnnl.gov RI Xu, Zhijie/A-1627-2009; OI Xu, Zhijie/0000-0003-0459-4531; Henager, Chuck/0000-0002-8600-6803 FU Nonproliferation Research and Engineering (NA-22) program; Applied Mathematics program of the US DOE Office of Advanced Scientific Computing Research; US Department of Energy [DE-AC05-76RL01830] FX supported by the Nonproliferation Research and Engineering (NA-22) program and the Applied Mathematics program of the US DOE Office of Advanced Scientific Computing Research. Computations were performed using the computational resources of the National Energy Research Scientific Computing Center at Lawrence Berkeley National Laboratory and the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL). EMSL is a DOE national scientific user facility located at PNNL. The Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy under Contract DE-AC05-76RL01830. NR 37 TC 2 Z9 2 U1 1 U2 11 PU GLOBAL SCIENCE PRESS PI WANCHAI PA ROOM 3208, CENTRAL PLAZA, 18 HARBOUR RD, WANCHAI, HONG KONG 00000, PEOPLES R CHINA SN 1815-2406 EI 1991-7120 J9 COMMUN COMPUT PHYS JI Commun. Comput. Phys. PD JAN PY 2014 VL 15 IS 1 BP 76 EP 92 DI 10.4208/cicp.300612.210313a PG 17 WC Physics, Mathematical SC Physics GA 269YE UT WOS:000328279800003 ER PT J AU Seleson, P Parks, ML Gunzburger, M AF Seleson, Pablo Parks, Michael L. Gunzburger, Max TI Peridynamic State-Based Models and the Embedded-Atom Model SO COMMUNICATIONS IN COMPUTATIONAL PHYSICS LA English DT Article DE Peridynamics; multibody potentials; embedded-atom; molecular dynamics ID MOLECULAR-DYNAMICS; FCC METALS; CLASSICAL ELASTICITY; CONTINUUM MODELS; DERIVATION; MECHANICS; ORDER AB We investigate connections between nonlocal continuum models and molecular dynamics. A continuous upscaling of molecular dynamics models of the form of the embedded-atom model is presented, providing means for simulating molecular dynamics systems at greatly reduced cost. Results are presented for structured and structureless material models, supported by computational experiments. The nonlocal continuum models are shown to be instances of the state-based peridynamics theory. Connections relating multibody peridynamic models and upscaled nonlocal continuum models are derived. C1 [Seleson, Pablo] Inst Computat Engn & Sci, Austin, TX 78712 USA. [Parks, Michael L.] Sandia Natl Labs, Ctr Res Comp, Albuquerque, NM 87185 USA. [Gunzburger, Max] Florida State Univ, Dept Comp Sci, Dirac Sci Lib 400, Tallahassee, FL 32306 USA. RP Seleson, P (reprint author), Inst Computat Engn & Sci, 201 East 24th St,Stop C0200, Austin, TX 78712 USA. EM seleson@ices.utexas.edu; mlparks@sandia.gov; gunzburg@fsu.edu OI Seleson, Pablo/0000-0003-3279-4231 FU Department of Energy [DE-SC0004970, DE-FG02-05ER25701]; National Science Foundation [DMS-1013845]; Laboratory Directed Research and Development program at Sandia National Laboratories; ICES Postdoctoral Fellowship Program FX The research at Florida State University was supported by the Department of Energy grant number DE-SC0004970 and the National Science Foundation under grant number DMS-1013845, at the University of Texas by the Department of Energy grant number DE-FG02-05ER25701, and by the Laboratory Directed Research and Development program at Sandia National Laboratories. The authors acknowledge helpful discussions with Stephen Foiles as well as valuable encouragement and suggestions of Richard Lehoucq from Sandia National Laboratories. The first author, Pablo Seleson, is also thankful for the support from the ICES Postdoctoral Fellowship Program. NR 41 TC 10 Z9 10 U1 0 U2 9 PU GLOBAL SCIENCE PRESS PI WANCHAI PA ROOM 3208, CENTRAL PLAZA, 18 HARBOUR RD, WANCHAI, HONG KONG 00000, PEOPLES R CHINA SN 1815-2406 EI 1991-7120 J9 COMMUN COMPUT PHYS JI Commun. Comput. Phys. PD JAN PY 2014 VL 15 IS 1 BP 179 EP 205 DI 10.4208/cicp.081211.300413a PG 27 WC Physics, Mathematical SC Physics GA 269YE UT WOS:000328279800007 ER PT J AU Onstott, TC Magnabosco, C Aubrey, AD Burton, AS Dworkin, JP Elsila, JE Grunsfeld, S Cao, BH Hein, JE Glavin, DP Kieft, TL Silver, BJ Phelps, TJ van Heerden, E Opperman, DJ Bada, JL AF Onstott, T. C. Magnabosco, C. Aubrey, A. D. Burton, A. S. Dworkin, J. P. Elsila, J. E. Grunsfeld, S. Cao, B. H. Hein, J. E. Glavin, D. P. Kieft, T. L. Silver, B. J. Phelps, T. J. van Heerden, E. Opperman, D. J. Bada, J. L. TI Does aspartic acid racemization constrain the depth limit of the subsurface biosphere? SO GEOBIOLOGY LA English DT Article ID BACTERIAL CELL-WALLS; AMINO-ACIDS; SOUTH-AFRICA; WITWATERSRAND BASIN; DEEP SUBSURFACE; ENERGY-REQUIREMENTS; HYPERTHERMOPHILIC ARCHAEA; ISOTOPE FRACTIONATION; LIQUID-CHROMATOGRAPHY; PETROLEUM RESERVOIRS AB Previous studies of the subsurface biosphere have deduced average cellular doubling times of hundreds to thousands of years based upon geochemical models. We have directly constrained the in situ average cellular protein turnover or doubling times for metabolically active micro-organisms based on cellular amino acid abundances, D/L values of cellular aspartic acid, and the in vivo aspartic acid racemization rate. Application of this method to planktonic microbial communities collected from deep fractures in South Africa yielded maximum cellular amino acid turnover times of similar to 89years for 1km depth and 27 degrees C and 1-2years for 3km depth and 54 degrees C. The latter turnover times are much shorter than previously estimated cellular turnover times based upon geochemical arguments. The aspartic acid racemization rate at higher temperatures yields cellular protein doubling times that are consistent with the survival times of hyperthermophilic strains and predicts that at temperatures of 85 degrees C, cells must replace proteins every couple of days to maintain enzymatic activity. Such a high maintenance requirement may be the principal limit on the abundance of living micro-organisms in the deep, hot subsurface biosphere, as well as a potential limit on their activity. The measurement of the D/L of aspartic acid in biological samples is a potentially powerful tool for deep, fractured continental and oceanic crustal settings where geochemical models of carbon turnover times are poorly constrained. Experimental observations on the racemization rates of aspartic acid in living thermophiles and hyperthermophiles could test this hypothesis. The development of corrections for cell wall peptides and spores will be required, however, to improve the accuracy of these estimates for environmental samples. C1 [Onstott, T. C.; Magnabosco, C.] Princeton Univ, Dept Geosci, Princeton, NJ 08544 USA. [Onstott, T. C.; Magnabosco, C.] Indiana Univ, NASA Astrobiol Inst, IPTAI, Bloomington, IN USA. [Aubrey, A. D.] CALTECH, Jet Prop Lab, Pasadena, CA USA. [Burton, A. S.] NASA, Lyndon B Johnson Space Ctr, Astromat Res & Explorat Sci Directorate, Houston, TX 77058 USA. [Dworkin, J. P.; Elsila, J. E.; Glavin, D. P.] NASA, Goddard Space Flight Ctr, Div Solar Syst Explorat, Greenbelt, MD 20771 USA. [Grunsfeld, S.] River Hill High Sch, Clarksville, MD USA. [Cao, B. H.; Hein, J. E.] Univ Calif Merced, Sch Nat Sci, Dept Chem & Chem Biol, Merced, CA USA. [Kieft, T. L.] New Mexico Inst Min & Technol, Dept Biol, Socorro, NM 87801 USA. [Silver, B. J.] ARCADIS US Inc, Cranbury, NJ USA. [Phelps, T. J.] Oak Ridge Natl Lab, Div Biosci, Oak Ridge, TN USA. [van Heerden, E.; Opperman, D. J.] Univ Orange Free State, Dept Microbial Biochem & Food Biotechnol, Bloemfontein, South Africa. [Bada, J. L.] Univ Calif San Diego, Scripps Inst Oceanog, Div Geosci Res, San Diego, CA 92103 USA. RP Onstott, TC (reprint author), Princeton Univ, Dept Geosci, Princeton, NJ 08544 USA. EM tullis@princeton.edu RI Glavin, Daniel/D-6194-2012; Opperman, Diederik/F-5400-2012; Burton, Aaron/H-2212-2011; Elsila, Jamie/C-9952-2012; Dworkin, Jason/C-9417-2012 OI Glavin, Daniel/0000-0001-7779-7765; Burton, Aaron/0000-0002-7137-1605; Dworkin, Jason/0000-0002-3961-8997 FU Jet Propulsion Laboratory, California Institute of Technology; NASA Astrobiology Institute [NNA04CC03A]; NSF [EAR-0948659, EAR-0948335] FX We would like to thank Gold Fields Ltd., Dawie Nell, and the managers and staff of Driefontein Au mine; Tim Hewitt and the managers and staff of Kloof; and Anglogold Ashanti Ltd., David Kershaw, and the managers and staff of Mponeng Au mine for their logistical support during the collection of the samples for this study. The laboratory analyses were completed at Scripps Institution of Oceanography, University of California at San Diego, and Goddard Space Flight Center, Greenbelt, Maryland. We thank David Culley of Pacific Northwest National Laboratory for providing the gel image of the MP104 DNA extract. This work was supported in part by an appointment to the NASA Postdoctoral Program at the Jet Propulsion Laboratory, California Institute of Technology, administered by Oak Ridge Associated Universities through a contract with NASA. T.C.O. acknowledges the support of NASA Astrobiology Institute through award NNA04CC03A to the IPTAI Team and Professor L. M. Pratt of Indiana University and to NSF through award EAR-0948659. T. L. K. acknowledges support from NSF (EAR-0948335 and EAR-0948335). We are grateful to two anonymous reviewers whose comments significantly improved the quality of the final manuscript. NR 91 TC 14 Z9 14 U1 2 U2 35 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1472-4677 EI 1472-4669 J9 GEOBIOLOGY JI Geobiology PD JAN PY 2014 VL 12 IS 1 BP 1 EP 19 DI 10.1111/gbi.12069 PG 19 WC Biology; Environmental Sciences; Geosciences, Multidisciplinary SC Life Sciences & Biomedicine - Other Topics; Environmental Sciences & Ecology; Geology GA 267HQ UT WOS:000328088500001 PM 24289240 ER PT J AU Kang, SJ Nair, SS Kline, KL Nichols, JA Wang, DL Post, WM Brandt, CC Wullschleger, SD Singh, N Wei, YX AF Kang, Shujiang Nair, Sujithkumar Surendran Kline, Keith L. Nichols, Jeffrey A. Wang, Dali Post, Wilfred M. Brandt, Craig C. Wullschleger, Stan D. Singh, Nagendra Wei, Yaxing TI Global simulation of bioenergy crop productivity: analytical framework and case study for switchgrass SO GLOBAL CHANGE BIOLOGY BIOENERGY LA English DT Article DE biofuel; biomass; EPIC; model; soil organic carbon; sustainability ID PANICUM-VIRGATUM; UNITED-STATES; BIOMASS; CLIMATE; MODELS; FUTURE; ENERGY; YIELD; SUSTAINABILITY; POPULATIONS AB A global energy crop productivity model that provides geospatially explicit quantitative details on biomass potential and factors affecting sustainability would be useful, but does not exist now. This study describes a modeling platform capable of meeting many challenges associated with global-scale agro-ecosystem modeling. We designed an analytical framework for bioenergy crops consisting of six major components: (i) standardized natural resources datasets, (ii) global field-trial data and crop management practices, (iii) simulation units and management scenarios, (iv) model calibration and validation, (v) high-performance computing (HPC) simulation, and (vi) simulation output processing and analysis. The HPC-Environmental Policy Integrated Climate (HPC-EPIC) model simulated a perennial bioenergy crop, switchgrass (Panicum virgatum L.), estimating feedstock production potentials and effects across the globe. This modeling platform can assess soil C sequestration, net greenhouse gas (GHG) emissions, nonpoint source pollution (e.g., nutrient and pesticide loss), and energy exchange with the atmosphere. It can be expanded to include additional bioenergy crops (e.g., miscanthus, energy cane, and agave) and food crops under different management scenarios. The platform and switchgrass field-trial dataset are available to support global analysis of biomass feedstock production potential and corresponding metrics of sustainability. C1 [Kang, Shujiang; Nair, Sujithkumar Surendran; Kline, Keith L.; Wang, Dali; Post, Wilfred M.; Wullschleger, Stan D.; Wei, Yaxing] Oak Ridge Natl Lab, Climate Change Sci Inst, Oak Ridge, TN 37831 USA. [Kang, Shujiang; Nair, Sujithkumar Surendran; Kline, Keith L.; Wang, Dali; Post, Wilfred M.; Wullschleger, Stan D.; Wei, Yaxing] Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. [Kline, Keith L.] Oak Ridge Natl Lab, Global Sustainable Bioenergy Project Crop Modelin, Oak Ridge, TN 37831 USA. [Kline, Keith L.] Oak Ridge Natl Lab, ORNL Ctr Sustainable Bioenergy, Oak Ridge, TN 37831 USA. [Nichols, Jeffrey A.; Singh, Nagendra] Oak Ridge Natl Lab, Computat Sci & Engn Div, Oak Ridge, TN 37831 USA. [Brandt, Craig C.] Oak Ridge Natl Lab, Biosci Div, Oak Ridge, TN 37831 USA. RP Kang, SJ (reprint author), Oak Ridge Natl Lab, Climate Change Sci Inst, Oak Ridge, TN 37831 USA. EM kangs@ornl.gov RI Wullschleger, Stan/B-8297-2012; OI Wullschleger, Stan/0000-0002-9869-0446; Kline, Keith/0000-0003-2294-1170 FU U.S. Department of Energy [DE-AC05-00OR22725]; ORNL FX Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract no. DE-AC05-00OR22725. We gratefully acknowledge ORNL, Martin Keller, and Gary Jacobs for supporting the research and the Global Sustainable Bioenergy (GSB) Project. We would like to thank Drs. R. Cesar Izaurralde and Xuesong Zhang at Pacific Northeast National Laboratory, Jimmy Williams at Texas A&M University, and James Kiniry of USDA-ARS for their support and discussions on global HPC-EPIC model simulation and calibration. We also thank Dr. Lee Lynd at Dartmouth College, Executive Director of the GSB Project, for encouragement and guidance over the course of this study. NR 52 TC 8 Z9 8 U1 5 U2 30 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1757-1693 EI 1757-1707 J9 GCB BIOENERGY JI GCB Bioenergy PD JAN PY 2014 VL 6 IS 1 BP 14 EP 25 DI 10.1111/gcbb.12047 PG 12 WC Agronomy; Biotechnology & Applied Microbiology; Energy & Fuels SC Agriculture; Biotechnology & Applied Microbiology; Energy & Fuels GA 264SO UT WOS:000327901000002 ER PT J AU Dogan, ON Song, X Palacio, D Gao, MC AF Dogan, Oe N. Song, X. Palacio, D. Gao, M. C. TI Coherent precipitation in a high-temperature Cr-Ni-Al-Ti Alloy SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID CHROMIUM-BASED ALLOYS; DESIGN; SYSTEM AB Chromium alloys present a potential for development of new high-temperature materials. Precipitation characteristics of a Cr-5Ni-5Al-0.5Ti (at.%) alloy were investigated utilizing a series of heat treatments. XRD, SEM, and analytical TEM were used to characterize the microstructure. This study has shown that the small spherical B2-NiAl precipitates forming below 1345 degrees C are highly coherent and have a well-defined orientation relationship with the Cr-matrix. Also, some evidence has been presented for the formation of L2(1)-Ni2AlTi phase within the B2-NiAl phase. C1 [Dogan, Oe N.; Gao, M. C.] Natl Energy Technol Lab, Albany, OR 97321 USA. [Song, X.; Palacio, D.] W Virginia Univ, Dept Mech & Aerosp Engn, Morgantown, WV 26506 USA. [Gao, M. C.] URS Corp, Albany, OR 97321 USA. RP Dogan, ON (reprint author), Natl Energy Technol Lab, 1450 Queen Ave SW, Albany, OR 97321 USA. EM omer.dogan@netl.doe.gov FU NETL's Strategic Center [DE-FE0004000] FX This research was performed in support of the Advanced Research Program of the NETL's Strategic Center for Coal under the RES contract DE-FE0004000. Assistance of Paul Danielson (metallography) and David Smith (XRD), both with NETL, is appreciated. This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. NR 12 TC 1 Z9 1 U1 2 U2 20 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2461 EI 1573-4803 J9 J MATER SCI JI J. Mater. Sci. PD JAN PY 2014 VL 49 IS 2 BP 805 EP 810 DI 10.1007/s10853-013-7763-1 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA 269RY UT WOS:000328260800038 ER PT S AU Hay, JO Schwender, J AF Hay, Jordan O. Schwender, Joerg BE DieuaideNoubhani, M Alonso, AP TI Flux Variability Analysis: Application to Developing Oilseed Rape Embryos Using Toolboxes for Constraint-Based Modeling SO PLANT METABOLIC FLUX ANALYSIS: METHODS AND PROTOCOLS SE Methods in Molecular Biology LA English DT Article; Book Chapter DE Stoichiometric modeling; Constraint-based modeling; Flux balance analysis; Flux variability analysis; Metabolic network; Linear programming ID SCALE METABOLIC MODEL; ESCHERICHIA-COLI; QUANTITATIVE PREDICTION; CELLULAR-METABOLISM; STORAGE SYNTHESIS; NETWORK MODELS; COBRA TOOLBOX; ARABIDOPSIS; RECONSTRUCTION; CAPABILITIES AB Flux variability analysis enables comprehensive exploration of alternate optimal routes in a metabolic network. This method is especially useful with models such as bna572 for the developing oilseed rape embryo which is highly compartmentalized. Here, we describe a protocol for carrying out flux variability analysis on reactions and network projections of bna572 using well-established software (CellNetAnalyzer and COBRA) for constraint-based analysis of stoichiometric network reconstructions. C1 [Hay, Jordan O.; Schwender, Joerg] Brookhaven Natl Lab, Dept Biosci, Upton, NY 11973 USA. RP Hay, JO (reprint author), Brookhaven Natl Lab, Dept Biosci, Upton, NY 11973 USA. RI Schwender, Jorg/P-2282-2014 OI Schwender, Jorg/0000-0003-1350-4171 NR 34 TC 1 Z9 1 U1 1 U2 5 PU HUMANA PRESS INC PI TOTOWA PA 999 RIVERVIEW DR, STE 208, TOTOWA, NJ 07512-1165 USA SN 1064-3745 BN 978-1-62703-688-7; 978-1-62703-687-0 J9 METHODS MOL BIOL JI Methods Mol. Biol. PY 2014 VL 1090 BP 301 EP 316 DI 10.1007/978-1-62703-688-7_18 D2 10.1007/978-1-62703-688-7 PG 16 WC Biochemical Research Methods; Plant Sciences SC Biochemistry & Molecular Biology; Plant Sciences GA BJH06 UT WOS:000328152700019 PM 24222423 ER PT J AU Hagberg, A Lemons, N Kent, A Neil, J AF Hagberg, Aric Lemons, Nathan Kent, Alex Neil, Joshua BE Yetongnon, K Dipanda, A Chbeir, R TI Connected Components and Credential Hopping in Authentication Graphs SO 10TH INTERNATIONAL CONFERENCE ON SIGNAL-IMAGE TECHNOLOGY AND INTERNET-BASED SYSTEMS SITIS 2014 LA English DT Proceedings Paper CT International Conference on Signal-Image Technology and Internet-Based Systems SITIS CY NOV 23-27, 2014 CL Marrakesh, MOROCCO ID RANDOM INTERSECTION GRAPHS AB Modern enterprise computer networks rely on centrally managed authentication schemes that allow users to easily communicate access credentials to many computer systems and applications. The authentication events typically consist of a user connecting to a computer with an authorized credential. These credentials are often cached on the application servers which creates a risk that they may be stolen and used to hop between computers in the network. We examine computer network risk associated with credential hopping by creating and studying the structure of the authentication graph, a bipartite graph built from authentication events. We assume that an authentication graph with many short paths between computers represents a network that is more vulnerable to such attacks. Under this natural assumption, we use a measure of graph connectivity, namely the size of the largest connected component, to give a quantitative indicator of the network's susceptibility to such attacks. Motivated by graph theoretical results for component sizes in random intersection graphs, we propose a mitigation strategy, and perform experiments simulating an implementation using data from a large enterprise network. The results lead to realistic, actionable risk reduction strategies. To facilitate continued research opportunities we are also providing our authentication bipartite graph data set spanning 9 months and 708 million time-series edge records. C1 [Hagberg, Aric; Lemons, Nathan] Los Alamos Natl Lab, Div Theoret, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. [Kent, Alex; Neil, Joshua] Los Alamos Natl Lab, Adv Comp Solut, Los Alamos, NM 87545 USA. RP Hagberg, A (reprint author), Los Alamos Natl Lab, Div Theoret, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. NR 17 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7978-3 PY 2014 BP 416 EP 423 DI 10.1109/SITIS.2014.95 PG 8 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA BF3PC UT WOS:000380564200063 ER PT J AU Mortona, A Marzban, E Giannoulis, G Patel, A Aparasu, R Kakadiaris, IA AF Mortona, April Marzban, Eman Giannoulis, Georgios Patel, Ayush Aparasu, Rajender Kakadiaris, Ioannis A. BE Chen, XW Qu, G Angelov, P Ferri, C Lai, JH Wani, MA TI A Comparison of Supervised Machine Learning Techniques for Predicting Short-Term In-Hospital Length of Stay Among Diabetic Patients SO 2014 13TH INTERNATIONAL CONFERENCE ON MACHINE LEARNING AND APPLICATIONS (ICMLA) LA English DT Proceedings Paper CT 13th International Conference on Machine Learning and Applications (ICMLA) CY DEC 03-06, 2014 CL Detroit, MI SP IEEE Comp Soc, AML&A, IEEE, Wayne State Univ DE Supervised Machine Learning; Support Vector Machines; Support Vector Machines Plus; Random Forests; Multi-Task Learning; Diabetes; In-Hospital Length of Stay Prediction AB Diabetes is a life-altering medical condition that affects millions of people and results in many hospitalizations per year. Consequently, predicting the length of stay of in-hospital diabetic patients has become increasingly important for staffing and resource planning. Although statistical methods have been used to predict length of stay in hospitalized patients, many powerful machine learning techniques have not yet been explored. In this paper, we compare and discuss the performance of various supervised machine learning algorithms (i.e., multiple linear regression, support vector machines, multi-task learning, and random forests) for predicting long versus short-term length of stay of hospitalized diabetic patients. C1 [Mortona, April] NCSR Demokritos, Athens, Greece. [Marzban, Eman] Cairo Univ, Giza, Egypt. [Giannoulis, Georgios; Patel, Ayush; Aparasu, Rajender; Kakadiaris, Ioannis A.] Univ Houston, Houston, TX USA. [Mortona, April] Oak Ridge Natl Lab, Oak Ridge, TN USA. RP Mortona, A (reprint author), NCSR Demokritos, Athens, Greece. EM april.m.morton@gmail.com; eman.marzban@eng.cu.edu.eg; aktorionreg@gmail.com; ayushpatel2008@gmail.com; raparasu@central.uh.edu; ikakadia@central.uh.edu NR 24 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7415-3 PY 2014 BP 428 EP 431 DI 10.1109/ICMLA.2014.76 PG 4 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications SC Computer Science GA BF2DW UT WOS:000380459000072 ER PT J AU Kamath, C Fan, YJ AF Kamath, Chandrika Fan, Ya Ju BE Chen, XW Qu, G Angelov, P Ferri, C Lai, JH Wani, MA TI Incremental SVD for Insight into Wind Generation SO 2014 13TH INTERNATIONAL CONFERENCE ON MACHINE LEARNING AND APPLICATIONS (ICMLA) LA English DT Proceedings Paper CT 13th International Conference on Machine Learning and Applications (ICMLA) CY DEC 03-06, 2014 CL Detroit, MI SP IEEE Comp Soc, AML&A, IEEE, Wayne State Univ AB In this paper, we formulate the problem of predicting wind generation as one of streaming data analysis. We want to understand if it is possible to use the weather data in a time window just before the current time to gain insight into how the wind generation might behave in a time interval just after the current time. Specifically, we use a singular value decomposition of the weather data, and show that the number of singular values and the largest singular value can be used to predict the magnitude of the change in the generation in the near future. The analysis uses an incremental algorithm based on a sliding window for reduced computational costs. C1 [Kamath, Chandrika; Fan, Ya Ju] Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94550 USA. RP Kamath, C (reprint author), Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94550 USA. EM kamath2@llnl.gov; fan4@llnl.gov 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 978-1-4799-7415-3 PY 2014 BP 441 EP 446 DI 10.1109/ICMLA.2014.77 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications SC Computer Science GA BF2DW UT WOS:000380459000074 ER PT J AU Abba, A Bedeschi, F Caponio, F Citterio, M Coelli, S Fu, J Geraci, A Marino, P Monti, M Morello, MJ Neri, N Piucci, A Petruzzo, M Punzi, G Ristori, L Spinella, F Stracka, S Tonelli, D Walsh, J AF Abba, A. Bedeschi, F. Caponio, F. Citterio, M. Coelli, S. Fu, J. Geraci, A. Marino, P. Monti, M. Morello, M. J. Neri, N. Piucci, A. Petruzzo, M. Punzi, G. Ristori, L. Spinella, F. Stracka, S. Tonelli, D. Walsh, J. GP IEEE TI A Retina-Based Cosmic Rays Telescope SO 2014 19TH IEEE-NPSS REAL TIME CONFERENCE (RT) LA English DT Proceedings Paper CT 19th IEEE-NPSS Real Time Conference (RT) CY MAY 26-30, 2014 CL Nara, JAPAN SP Osaka Univ, Res Nucl Phys, IEEE Nucl & Plasma Sci Soc AB We present the design for the first prototype of a tracking system with "artificial retina" for fast track finding. The "artificial retina" is a tracking algorithm inspired by neurobiology and based on extensive parallelization of data distribution and pattern recognition. It allows track finding with a latency < I mu s and with track parameter resolutions that are comparable with offline reconstruction results. This tracking system prototype consists of a telescope with 8 planes of single-sided strip detectors that are readout using custom ASICs providing hit position and pulse height. The "artificial retina" algorithm can be implemented using commercial FPGAs organized in three main blocks: a switch for the parallel distribution of the hits, a pool of processing units for the digital processing of the hits and pattern recognition, and a block fir track parameter calculations. We will discuss the implementation of the "artificial retina" algorithm in the FPGAs, the performance of the device, and the perspectives for possible future applications. C1 [Abba, A.; Caponio, F.; Citterio, M.; Coelli, S.; Fu, J.; Geraci, A.; Monti, M.; Neri, N.; Petruzzo, M.] Ist Nazl Fis Nucl, Sez Milano, Rome, Italy. [Fu, J.; Stracka, S.; Tonelli, D.] CERN, Geneva, Switzerland. [Abba, A.; Caponio, F.; Geraci, A.] Politecn Milan, Milan, Italy. [Bedeschi, F.; Marino, P.; Morello, M. J.; Piucci, A.; Punzi, G.; Ristori, L.; Spinella, F.; Stracka, S.] Ist Nazl Fis Nucl, Sez Pisa, Rome, Italy. [Ristori, L.] Fermilab Natl Accelerator Lab, Batavia, IL USA. [Marino, P.; Morello, M. J.; Stracka, S.] Scuola Normale Super Pisa, Pisa, PI, Italy. [Piucci, A.; Punzi, G.] Univ Pisa, I-56100 Pisa, Italy. RP Abba, A (reprint author), Politecn Milan, Milan, Italy. 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 BN 978-1-4799-3659-5 PY 2014 PG 3 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF3WU UT WOS:000380588000112 ER PT J AU Akerstedt, H Muschter, S Drake, G Anderson, K Bohm, C Oreglia, M Tang, FK AF Akerstedt, Henrik Muschter, Steffen Drake, Gary Anderson, Kelby Bohm, Christian Oreglia, Mark Tang, Fukun CA ATLAS TileCal Collaboration GP IEEE TI Reliable and Redundant FPGA Based Read-out Design in the ATLAS TileCal Demonstrator SO 2014 19TH IEEE-NPSS REAL TIME CONFERENCE (RT) LA English DT Proceedings Paper CT 19th IEEE-NPSS Real Time Conference (RT) CY MAY 26-30, 2014 CL Nara, JAPAN SP Osaka Univ, Res Nucl Phys, IEEE Nucl & Plasma Sci Soc DE FPGA; Radiation tolerance; High Speed Optical transmission; Tile Calorimeter AB The Tile calorimeter at ATLAS [1] is a hadron calorimeter based on steel plates and scintillating tiles read out by PMTs. The current read-out system uses standard ADCs and custom ASICs to digitize and temporarily store the data on the detector, before transfer to the counting room. The on-detector electronics will be replaced around 2023. The higher radiation levels expected when the beam luminosity is increased require radiation tolerant components. To achieve the required reliability the upgraded system must be highly redundant. To provide flexibility the ASICs will be replaced with Kintex-7 FPGAs from Xilinx. This, in addition to the use of multiple 10 Gbps optical read-out links, will allow a full read-out of all detector data. Within a year, a "demonstrator" with the new read-out system will be installed in ATLAS, replacing one slice of the Tile calorimeter. This will allow the upgrade proposed for 2023 to be thoroughly evaluated well before deployment in all TileCal slices. Different firmware strategies alongside with their integration in the demonstrator will be presented in the context of high reliability protection against hardware malfunction and radiation induced errors. C1 [Akerstedt, Henrik; Muschter, Steffen; Bohm, Christian] Stockholm Univ, Stockholm, Sweden. [Anderson, Kelby; Oreglia, Mark; Tang, Fukun] Univ Chicago, Chicago, IL 60637 USA. [Drake, Gary] Argonne Natl Lab, Chicago, IL USA. RP Akerstedt, H (reprint author), Stockholm Univ, Stockholm, Sweden. EM henrik.akerstedt@fysik.su.se 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 978-1-4799-3659-5 PY 2014 PG 3 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF3WU UT WOS:000380588000139 ER PT J AU Attie, D Aune, S Baron, P Besin, D Bervas, H Delagnes, E Gautard, V Giraud, J Granelli, R Mandjavidze, I Monmarthe, E Moudden, Y Procureur, S Raydo, B Riallot, M Sabatie, F AF Attie, D. Aune, S. Baron, P. Besin, D. Bervas, H. Delagnes, E. Gautard, V. Giraud, J. Granelli, R. Mandjavidze, I. Monmarthe, E. Moudden, Y. Procureur, S. Raydo, B. Riallot, M. Sabatie, F. GP IEEE TI The Readout System for the Clas12 Micromegas Vertex Tracker SO 2014 19TH IEEE-NPSS REAL TIME CONFERENCE (RT) LA English DT Proceedings Paper CT 19th IEEE-NPSS Real Time Conference (RT) CY MAY 26-30, 2014 CL Nara, JAPAN SP Osaka Univ, Res Nucl Phys, IEEE Nucl & Plasma Sci Soc AB In this paper, the architecture of the Clas12 Micromegas vertex tracker readout is described and the details of its implementation are given. The innovations allowing to meet the challenging requirements of the tracker operation are presented. The system performance is evaluated based on detector tests with a cosmic rays trigger and on standalone high rate validation tests. Finally, the perspectives to adapt the readout system or a part of it to other experiments are discussed. C1 [Attie, D.; Aune, S.; Baron, P.; Besin, D.; Bervas, H.; Delagnes, E.; Gautard, V.; Giraud, J.; Granelli, R.; Mandjavidze, I.; Monmarthe, E.; Moudden, Y.; Procureur, S.; Riallot, M.; Sabatie, F.] CEA Saclay, Irfu, F-91191 Gif Sur Yvette, France. [Raydo, B.] Jefferson Lab, Newport News, VA 23606 USA. RP Mandjavidze, I (reprint author), CEA Saclay, Irfu, F-91191 Gif Sur Yvette, France. EM Irakli.Mandjavidze@cea.fr NR 28 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-3659-5 PY 2014 PG 11 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF3WU UT WOS:000380588000114 ER PT J AU Fox, R Tompkins, J Varner, R Cromaz, M Teh, K Anderson, JT AF Fox, Ron Tompkins, Jeromy Varner, Robert Cromaz, Mario Teh, Ken Anderson, John T. GP IEEE TI The Data Acquisition System for the Facility for Rare Isotope Beams SO 2014 19TH IEEE-NPSS REAL TIME CONFERENCE (RT) LA English DT Proceedings Paper CT 19th IEEE-NPSS Real Time Conference (RT) CY MAY 26-30, 2014 CL Nara, JAPAN SP Osaka Univ, Res Nucl Phys, IEEE Nucl & Plasma Sci Soc AB The Facility for Rare Isotope Beams (FRIB) is a DOE funded laboratory that is under construction at what is now the National Superconducting Cyclotron Laboratory at Michigan State University. Scheduled for commissioning in 2022, there are ongoing, lively discussions about the data acquisition system for FRIB, what it will look like and the role it will play in FRIB experiments. This paper reports on the current overall design goals, technologies and work in progress to meet those goals. C1 [Fox, Ron; Tompkins, Jeromy] Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA. [Varner, Robert] Oak Ridge Natl Lab, Oak Ridge, TN USA. [Cromaz, Mario] Lawrence Berkeley Natl Lab, Berkeley, CA USA. [Teh, Ken; Anderson, John T.] Argonne Natl Lab, Argonne, IL 60439 USA. RP Fox, R (reprint author), Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA. 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 978-1-4799-3659-5 PY 2014 PG 6 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF3WU UT WOS:000380588000104 ER PT J AU Moeller-Chan, V Hasenohr, T Stezelberger, T Turqueti, M Zimmermann, S AF Moeller-Chan, Victoria Hasenohr, Thomas Stezelberger, Thorsten Turqueti, Marcos Zimmermann, Sergio GP IEEE TI Microphonic Noise Cancellation in Radiation Detectors Using Real-Time Adaptive Modeling SO 2014 19TH IEEE-NPSS REAL TIME CONFERENCE (RT) LA English DT Proceedings Paper CT 19th IEEE-NPSS Real Time Conference (RT) CY MAY 26-30, 2014 CL Nara, JAPAN SP Osaka Univ, Res Nucl Phys, IEEE Nucl & Plasma Sci Soc ID NUCLEAR ARRAY GRETINA; PERFORMANCE AB Mechanical disturbances in radiation detectors can cause microphonic noise and reduce energy resolution. Recently, we have proposed a system to cancel the microphonic noise using real-time adaptive modeling. In this paper we are reporting an FPGA implementation of such algorithm. We have concluded that, because the operations of the algorithm are done using a decimated sampling rate, it uses minimum resources inside the FPGA. C1 [Moeller-Chan, Victoria; Hasenohr, Thomas; Stezelberger, Thorsten; Turqueti, Marcos; Zimmermann, Sergio] Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. [Hasenohr, Thomas] Hsch Karlsruhe Tech & Wirtschaft, Karlsruhe, Germany. RP Zimmermann, S (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. EM szimmermann@lbl.gov NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-3659-5 PY 2014 PG 4 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF3WU UT WOS:000380588000017 ER PT J AU Wernhoff, C Nygren, D Bohm, C Hulth, PO AF Wernhoff, Carl Nygren, D. Bohm, C. Hulth, P. O. CA IceCube Collaboration GP IEEE TI The Track Engine - an FPGA Implementation of a Track-finding Algorithm for the IceCube Neutrino Telescope SO 2014 19TH IEEE-NPSS REAL TIME CONFERENCE (RT) LA English DT Proceedings Paper CT 19th IEEE-NPSS Real Time Conference (RT) CY MAY 26-30, 2014 CL Nara, JAPAN SP Osaka Univ, Res Nucl Phys, IEEE Nucl & Plasma Sci Soc AB The Track Engine is an additional low-energy trigger and track reconstructor for the IceCube Neutrino Telescope. IceCube is built within the ice on the geographical South Pole, Antarctica. A neutrino interacting with an ice molecule might produce a muon, in turn emitting a trace of photons which can be detected by the detector. Efficiently finding low-energy tracks requires complex computations in realtime. An FPGA implementation was developed for this task. The Track Engine increases the trigger sensitivity with approximately 10% and it has a very low rate of false triggers. The rate that the Track Engine can process hits is a factor two to four faster than the average hit rate produced by the detector and hence Track Engine offers a comforting performance margin. Implementing a given algorithm in hardware yields superior performance compared to a software implementation. This paper presents the Track Engine system, the algorithm implemented, and discusses some of the challenges and solutions for transforming a given algorithm to a digital design implementation. C1 [Wernhoff, Carl; Bohm, C.; Hulth, P. O.] Stockholm Univ, Stockholm, Sweden. [Nygren, D.] LBNL, Berkeley, CA USA. RP Wernhoff, C (reprint author), Stockholm Univ, Stockholm, Sweden. NR 9 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-3659-5 PY 2014 PG 5 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF3WU UT WOS:000380588000093 ER PT J AU Wu, JY AF Wu, Jinyuan GP IEEE TI Uneven Bin Width Digitization and a Timing Calibration Method Using Cascaded PLL SO 2014 19TH IEEE-NPSS REAL TIME CONFERENCE (RT) LA English DT Proceedings Paper CT 19th IEEE-NPSS Real Time Conference (RT) CY MAY 26-30, 2014 CL Nara, JAPAN SP Osaka Univ, Res Nucl Phys, IEEE Nucl & Plasma Sci Soc DE Fast Timing; Front end electronics; Phase Lock Loop; Time to digital converters ID FPGAS AB Digitizers with uneven bin widths become more practical as the calibration in digital domain becomes convenient. In order to specify and compare the measurement ability of digitizers with uneven bin widths, it is necessary to define a parameter that takes effects of the various bin widths into account. In this paper, a parameter called equivalent bin width is defined based on mechanism of digitization. A scheme for timing bin widths calibration using cascaded phase lock loop (PLL) circuits is also presented in this document. C1 [Wu, Jinyuan] Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. RP Wu, JY (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM jywu168@fnal.gov 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 BN 978-1-4799-3659-5 PY 2014 PG 4 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF3WU UT WOS:000380588000131 ER PT J AU Wurtz, RE Chen, CD Glenn, AM Keefer, GJ Nakae, LF Pawelczak, I Sheets, SA Verbeke, JM AF Wurtz, R. E. Chen, C. D. Glenn, A. M. Keefer, G. J. Nakae, L. F. Pawelczak, I. Sheets, S. A. Verbeke, J. M. GP IEEE TI Realtime Assessment of Nuclear Materials SO 2014 19TH IEEE-NPSS REAL TIME CONFERENCE (RT) LA English DT Proceedings Paper CT 19th IEEE-NPSS Real Time Conference (RT) CY MAY 26-30, 2014 CL Nara, JAPAN SP Osaka Univ, Res Nucl Phys, IEEE Nucl & Plasma Sci Soc ID PULSE-SHAPE DISCRIMINATION AB Our group at Livermore Lab specializes in nuclear materials measurements and assessments. We have built detectors that we have taken from breadboard to fieldable. We have even commercialized some detectors for rugged non-expert use, such as the Fission Meter - a thermal neutron multiplicity counter and the Detective - a mechanically-cooled germanium spectrometer. We are currently developing instrumentation and analysis algorithms that rely on fast neutron and gamma scintillator detectors. Our systems merge data from dozens of detectors at rates of a million events per second. Fast neutron and gamma arrival times and energy can be used to assay fissioning materials and estimate moderation and shielding, as well as make 3-D images. The underlying hardware and software to operate these detection systems represent a jump in complexity from the previous systems and are similar to subsystems of high energy and particle physics. We will describe the challenges to convert these scintillator detection systems from expert-user laboratory instruments to non-expert field use, including automating pulse-analysis, data-cuts, data-calibration, data-compression, and especially real-time analysis and assessment. C1 [Wurtz, R. E.; Chen, C. D.; Glenn, A. M.; Keefer, G. J.; Nakae, L. F.; Pawelczak, I.; Sheets, S. A.; Verbeke, J. M.] Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Wurtz, RE (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. EM wurtz@llnl.gov 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 978-1-4799-3659-5 PY 2014 PG 3 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF3WU UT WOS:000380588000091 ER PT J AU Pakin, S AF Pakin, Scott GP IEEE TI Parallel Post-processing with MPI-Bash SO 2014 1ST INTERNATIONAL WORKSHOP ON HPC USER SUPPORT TOOLS (HUST) LA English DT Proceedings Paper CT International Workshop on HPC User Support Tools CY NOV 16-21, 2014 CL New Orleans, LA SP HPC UGent, VSC, PAWSEY, IEEE Comp Soc, SIGHPC ID PYTHON AB Parallel, scientific applications running on massively parallel supercomputers commonly produce large numbers of large data files. While parallel filesystems improve the performance of file generation, post-processing activities such as archiving and compressing the data or performing routine format transformations are often run sequentially (and therefore slowly), squandering the supercomputer's vast performance. Consequently, data that take hours to generate may take days to post-process. Because post-processing often consists of running a relatively small set of shell commands on a relatively large number of files and because most parallel-application developers are comfortable with MPI we propose turning the shell itself into an MPI program and exposing common MPI functions directly to user-written shell scripts. Our implementation, MPI-Bash, has been used to date to speed up the compression, archiving, and transfer of large files but can conceivably be applied to numerous other purposes. C1 [Pakin, Scott] Los Alamos Natl Lab, Comp Computat & Stat Sci Div, Los Alamos, NM 87545 USA. RP Pakin, S (reprint author), Los Alamos Natl Lab, Comp Computat & Stat Sci Div, Los Alamos, NM 87545 USA. EM pakin@lanl.gov OI Pakin, Scott/0000-0002-5220-1985 NR 22 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4673-6755-4 PY 2014 BP 1 EP 12 DI 10.1109/HUST.2014.9 PG 12 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BF2HU UT WOS:000380468900001 ER PT S AU Marquez, A Manzano, J Song, SWL Meister, B Shrestha, S St John, T Gao, G AF Marquez, Andres Manzano, Joseph Song, Shuaiwen Leon Meister, Benoit Shrestha, Sunil St John, Thomas Gao, Guang GP IEEE TI ACDT: Architected Composite Data Types Trading-in Unfettered Data Access for Improved Execution SO 2014 20TH IEEE INTERNATIONAL CONFERENCE ON PARALLEL AND DISTRIBUTED SYSTEMS (ICPADS) SE International Conference on Parallel and Distributed Systems - Proceedings LA English DT Proceedings Paper CT 20th IEEE International Conference on Parallel and Distributed Systems (ICPADS) CY DEC 16-19, 2014 CL Hsinchu, TAIWAN SP IEEE, IEEE Comp Soc AB With Exascale performance and its challenges in mind, one ubiquitous concern among architects is energy efficiency. Petascale systems projected to Exascale systems are unsustainable at current power consumption rates. One major contributor to system-wide power consumption is the number of memory operations leading to data movement and management techniques applied by the runtime system. To address this problem, we present the concept of the Architected Composite Data Types (ACDT) framework. The framework is made aware of data composites, assigning them a specific layout, transformations and operators. Data manipulation overhead is amortized over a larger number of elements and program performance and power efficiency can be significantly improved. We developed the fundamentals of an ACDT framework on a massively multithreaded adaptive runtime system geared towards Exascale clusters. Showcasing the capability of ACDT, we exercised the framework with two representative processing kernels - Matrix Vector Multiply and the Cholesky Decomposition - applied to sparse matrices. As transformation modules, we applied optimized compress/decompress engines and configured invariant operators for maximum energy/performance efficiency. Additionally, we explored two different approaches based on transformation opaqueness in relation to the application. Under the first approach, the application is agnostic to compression and decompression activity. Such approach entails minimal changes to the original application code, but leaves out potential application-specific optimizations. The second approach exposes the decompression process to the application, hereby exposing optimization opportunities that can only be exploited with application knowledge. The experimental results show that the two approaches have their strengths in HW and SW respectively, where the SW approach can yield performance and power improvements that are an order of magnitude better than ACDT-oblivious, hand-optimized implementations. We consider the ACDT runtime framework an important component of compute nodes that will lead towards power efficient Exascale clusters. C1 [Marquez, Andres; Manzano, Joseph; Song, Shuaiwen Leon] Pacific Northwest Natl Lab, Richland, WA 99352 USA. [Meister, Benoit] Reservoir Labs, New York, NY USA. [Shrestha, Sunil; St John, Thomas; Gao, Guang] Univ Delaware, Newark, DE 19716 USA. RP Marquez, A (reprint author), Pacific Northwest Natl Lab, Richland, WA 99352 USA. EM andres.marquez@pnnl.gov; joseph.manzano@pnnl.gov; shuaiwen.song@pnnl.gov; meister@reservoir.com; shrestha@capsl.udel.edu; stjohn@capsl.udel.edu; ggao@capsl.udel.edu FU DOE ASCR XStack program [DE-SC0008716, DE-SC0008717] FX This research was supported in part by DOE ASCR XStack program under Awards DE-SC0008716, DE-SC0008717. NR 25 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1521-9097 BN 978-1-4799-7615-7 J9 INT C PAR DISTRIB SY PY 2014 BP 289 EP 297 PG 9 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BG9LJ UT WOS:000393387400037 ER PT S AU Matheny, M Herbein, S Podhorszki, N Klasky, S Taufer, M AF Matheny, M. Herbein, S. Podhorszki, N. Klasky, S. Taufer, M. GP IEEE TI Using Surrogate-based Modeling to Predict Optimal I/O Parameters of Applications at the Extreme Scale SO 2014 20TH IEEE INTERNATIONAL CONFERENCE ON PARALLEL AND DISTRIBUTED SYSTEMS (ICPADS) SE International Conference on Parallel and Distributed Systems - Proceedings LA English DT Proceedings Paper CT 20th IEEE International Conference on Parallel and Distributed Systems (ICPADS) CY DEC 16-19, 2014 CL Hsinchu, TAIWAN SP IEEE, IEEE Comp Soc DE Scientific applications; Peta- and exascale computing; I/O modeling and tuning; Irregular I/O pattern; QMCPack AB On petascale systems, the selection of optimal values for I/O parameters without taking into account the I/O size and pattern can cause the I/O time to dominate the simulation time, compromising the application's scalability. In this paper, we adopt and adapt an engineering method called surrogate-based modeling to efficiently search for the optimal I/O parameter values and accurately predict the associated I/O times at the extreme scale. Our approach allows us to address both the search and prediction in a short time, even when the application's I/O is large and exhibits irregular patterns. C1 [Matheny, M.; Herbein, S.; Taufer, M.] Univ Delaware, Newark, DE 19716 USA. [Podhorszki, N.; Klasky, S.] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Matheny, M (reprint author), Univ Delaware, Newark, DE 19716 USA. EM micmath@udel.edu; sherbein@udel.edu; pnorbert@ornl.gov; klasky@ornl.gov; taufer@udel.edu RI Herbein, Stephen/J-2017-2016 OI Herbein, Stephen/0000-0003-0141-0653 FU NSF CCF [1318445]; Predictive Theory and Modeling for Materials and Chemical Science program by the Office of Basic Energy Science (BES), Department of Energy (DOE); Office of Science of the U.S. Department of Energy [DE-AC05-00OR22725] FX This work was done by two undergraduate students, M.M. and S.H. The work is supported in part by NSF CCF#1318445 and through the Predictive Theory and Modeling for Materials and Chemical Science program by the Office of Basic Energy Science (BES), Department of Energy (DOE). This research used resources of the Oak Ridge Leadership Computing Facility at the 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. NR 14 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1521-9097 BN 978-1-4799-7615-7 J9 INT C PAR DISTRIB SY PY 2014 BP 568 EP 575 PG 8 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BG9LJ UT WOS:000393387400072 ER PT S AU Chiu, HT Chou, J Vishwanath, V Byna, S Wu, KS AF Chiu, Hsuan-Te Chou, Jerry Vishwanath, Venkat Byna, Surendra Wu, Kesheng GP IEEE TI Simplifying Index File Structure to Improve I/O Performance of Parallel Indexing SO 2014 20TH IEEE INTERNATIONAL CONFERENCE ON PARALLEL AND DISTRIBUTED SYSTEMS (ICPADS) SE International Conference on Parallel and Distributed Systems - Proceedings LA English DT Proceedings Paper CT 20th IEEE International Conference on Parallel and Distributed Systems (ICPADS) CY DEC 16-19, 2014 CL Hsinchu, TAIWAN SP IEEE, IEEE Comp Soc DE Parallel I/O; Storage system; Bitmap indexing AB Complex indexing techniques are needed to reduce the time of analyzing massive scientific datasets, but generating these indexing data structures can be very time consuming. In this work, we propose a set of strategies to simplify the index file structure and to improve the I/O performance during index construction using FastQuery, which is a parallel indexing and querying system for scientific data. FastQuery has been used to analyze data from various scientific applications, including a trillion plasma particles simulation. To accelerate query process, FastQuery uses FastBit to build indexes, and then stores the indexes into file system through parallel scientific data format libraries, such as HDF5. Although these data format libraries are designed to support more complex multi-dimensional arrays, we observed that it still takes considerable work to map the indexing data structures into arrays, especially on parallel machines. To address this problem, in this paper, we attempt to minimize the I/O time by storing indexes into our self-defined binary data format. By fully controlling the data structure, we can minimize the I/O synchronization overhead and explore more efficient I/O strategy for storing indexes. Our experiments of indexing a trillion particle dataset using 20,000 cores of a supercomputer show that the proposed binary I/O driver can reach 85% of the peak I/O bandwidth on the system, and achieves a speedup of up to 4X in terms of the total execution time comparing to the previous FastQuery implementation with HDF5 I/O driver. C1 [Chiu, Hsuan-Te; Chou, Jerry] Natl Tsing Hua Univ, Hsinchu 30013, Taiwan. [Vishwanath, Venkat] Argonne Natl Lab, Argonne, IL 60439 USA. [Byna, Surendra; Wu, Kesheng] Lawrence Berkeley Natl Lab, Berkeley, CA USA. RP Chiu, HT (reprint author), Natl Tsing Hua Univ, Hsinchu 30013, Taiwan. EM albertchiu@lsalab.cs.nthu.edu.tw; jchou@lsalab.cs.nthu.edu.tw; venkat@anl.gov; sbyna@lbl.gov; kwu@lbl.gov NR 19 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1521-9097 BN 978-1-4799-7615-7 J9 INT C PAR DISTRIB SY PY 2014 BP 576 EP 583 PG 8 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BG9LJ UT WOS:000393387400073 ER PT S AU Ozog, D Malony, A Hammond, JR Balaji, P AF Ozog, David Malony, Allen Hammond, Jeff R. Balaji, Pavan GP IEEE TI WorkQ: A Many-Core Producer/Consumer Execution Model Applied to PGAS Computations SO 2014 20TH IEEE INTERNATIONAL CONFERENCE ON PARALLEL AND DISTRIBUTED SYSTEMS (ICPADS) SE International Conference on Parallel and Distributed Systems - Proceedings LA English DT Proceedings Paper CT 20th IEEE International Conference on Parallel and Distributed Systems (ICPADS) CY DEC 16-19, 2014 CL Hsinchu, TAIWAN SP IEEE, IEEE Comp Soc DE Producer/Consumer; PGAS; Global Arrays; Tensor Contractions; Quantum Chemistry; Performance Evaluation ID COUPLED-CLUSTER; NWCHEM AB Partitioned global address space (PGAS) applications, such as the Tensor Contraction Engine (TCE) in NWChem, often apply a one-process-per-core mapping in which each process iterates through the following work-processing cycle: (1) determine a work-item dynamically, (2) get data via one-sided operations on remote blocks, (3) perform computation on the data locally, (4) put (or accumulate) resultant data into an appropriate remote location, and (5) repeat the cycle. However, this simple flow of execution does not effectively hide communication latency costs despite the opportunities for making asynchronous progress. Utilizing nonblocking communication calls is not sufficient unless care is taken to efficiently manage a responsive queue of outstanding communication requests. This paper presents a new runtime model and its library implementation for managing tunable "work queues" in PGAS applications. Our runtime execution model, called WorkQ, assigns some number of on-node "producer" processes to primarily do communication (steps 1, 2, 4, and 5) and the other "consumer" processes to do computation (step 3); but processes can switch roles dynamically for the sake of performance. Load balance, synchronization, and overlap of communication and computation are facilitated by a tunable nodewise FIFO message queue protocol. Our WorkQ library implementation enables an MPI+X hybrid programming model where the X comprises SysV message queues and the user's choice of SysV, POSIX, and MPI shared memory. We develop a simplified software mini-application that mimics the performance behavior of the TCE at arbitrary scale, and we show that the WorkQ engine outperforms the original model by about a factor of 2. We also show performance improvement in the TCE coupled cluster module of NWChem. C1 [Ozog, David; Malony, Allen] Univ Oregon, Dept Comp & Informat Sci, Eugene, OR 97403 USA. [Hammond, Jeff R.] Intel Corp, Parallel Comp Lab, Hillsboro, OR 97124 USA. [Balaji, Pavan] Argonne Natl Lab, Div Math & Comp Sci, Lemont, IL 60439 USA. RP Ozog, D (reprint author), Univ Oregon, Dept Comp & Informat Sci, Eugene, OR 97403 USA. EM ozog@uoregon.edu; malony@uoregon.edu; jeff_hammond@acm.org; balaji@anl.gov FU Department of Energy Computational Science Graduate Fellowship (DOE CSGF) program [DE-FG02-97ER25308]; Office of Science of the U.S. Department of Energy [DE-AC02-06CH11357]; U.S. Department of Energy, Office of Science [DE-FG02-07ER25826, DE-SC0001777, DE-FG02-09ER25873] FX D. Ozog is supported by the Department of Energy Computational Science Graduate Fellowship (DOE CSGF) program under contract DE-FG02-97ER25308. This research used resources of the Argonne Leadership Computing Facility and the Laboratory Computing Resource Center at Argonne National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under contract DE-AC02-06CH11357. The research at the University of Oregon was supported by grants from the U.S. Department of Energy, Office of Science, under contracts DE-FG02-07ER25826, DE-SC0001777, and DE-FG02-09ER25873. NR 22 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1521-9097 BN 978-1-4799-7615-7 J9 INT C PAR DISTRIB SY PY 2014 BP 632 EP 639 PG 8 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BG9LJ UT WOS:000393387400080 ER PT S AU Wang, FY Oral, S Gupta, S Tiwari, D Vazhkudai, SS AF Wang, Feiyi Oral, Sarp Gupta, Saurabh Tiwari, Devesh Vazhkudai, Sudharshan S. GP IEEE TI Improving Large-scale Storage System Performance via Topology-aware and Balanced Data Placement SO 2014 20TH IEEE INTERNATIONAL CONFERENCE ON PARALLEL AND DISTRIBUTED SYSTEMS (ICPADS) SE International Conference on Parallel and Distributed Systems - Proceedings LA English DT Proceedings Paper CT 20th IEEE International Conference on Parallel and Distributed Systems (ICPADS) CY DEC 16-19, 2014 CL Hsinchu, TAIWAN SP IEEE, IEEE Comp Soc DE Storage Area Network; Parallel File System; High Performance Computing; Performance Evaluation AB With the advent of big data, the I/O subsystems of large-scale compute clusters are becoming a center of focus. More applications are putting greater demands on end-to-end I/O performance. These subsystems are often complex in design. They comprise of multiple hardware and software layers to cope with the increasing capacity, capability, and scalability requirements of data intensive applications. However, the sharing nature of storage resources and the intrinsic interactions across these layers make it a great challenge to realize end-to-end performance gains. This paper proposes a topology-aware strategy to balance the load across resources, to improve the per-application I/O performance. We demonstrate the effectiveness of our algorithm on an extreme-scale compute cluster, Titan, at the Oak Ridge Leadership Computing Facility (OLCF). Our experiments with both synthetic benchmarks and a real-world application show that, even under congestion, our proposed algorithm can improve large-scale application I/O performance significantly, resulting in both a reduction in application run time as well as a higher resolution of simulation run. C1 [Wang, Feiyi; Oral, Sarp; Gupta, Saurabh; Tiwari, Devesh; Vazhkudai, Sudharshan S.] Oak Ridge Natl Lab, Natl Ctr Computat Sci, Oak Ridge, TN 37830 USA. RP Wang, FY (reprint author), Oak Ridge Natl Lab, Natl Ctr Computat Sci, Oak Ridge, TN 37830 USA. EM fwang2@ornl.gov; oralhs@ornl.gov; guptas1@ornl.gov; tiwari@ornl.gov; vazhkudaiss@ornl.gov FU Office of Science of the Department of Energy [DE-AC05-00OR22725] FX This research used resources of the Oak Ridge Leadership Computing Facility, located in the National Center for Computational Sciences at Oak Ridge National Laboratory, which is supported by the Office of Science of the Department of Energy under Contract DE-AC05-00OR22725. 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 1521-9097 BN 978-1-4799-7615-7 J9 INT C PAR DISTRIB SY PY 2014 BP 656 EP 663 PG 8 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BG9LJ UT WOS:000393387400083 ER PT S AU Bhatele, A Jain, N Isaacs, KE Buch, R Gamblin, T Langer, SH Kale, LV AF Bhatele, Abhinav Jain, Nikhil Isaacs, Katherine E. Buch, Ronak Gamblin, Todd Langer, Steven H. Kale, Laxmikant V. GP IEEE TI Optimizing the performance of parallel applications on a 5D torus via task mapping SO 2014 21ST INTERNATIONAL CONFERENCE ON HIGH PERFORMANCE COMPUTING (HIPC) SE International Conference on High Performance Computing LA English DT Proceedings Paper CT 21st International Conference on High Performance Computing (HiPC) CY DEC 17-20, 2014 CL Goa, INDIA DE task mapping; 5D torus; performance; congestion AB Six of the ten fastest supercomputers in the world in 2014 use a torus interconnection network for message passing between compute nodes. Torus networks provide high bandwidth links to near-neighbors and low latencies over multiple hops on the network. However, large diameters of such networks necessitate a careful placement of parallel tasks on the compute nodes to minimize network congestion. This paper presents a methodological study of optimizing application performance on a five-dimensional torus network via the technique of topology-aware task mapping. Task mapping refers to the placement of processes on compute nodes while carefully considering the network topology between the nodes and the communication behavior of the application. We focus on the IBM Blue Gene/Q machine and two production applications a laser-plasma interaction code called pF3D and a lattice QCD application called MILC. Optimizations presented in the paper improve the communication performance of pF3D by 90% and that of MILC by up to 47%. C1 [Bhatele, Abhinav; Jain, Nikhil; Isaacs, Katherine E.; Gamblin, Todd; Langer, Steven H.] Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. [Jain, Nikhil; Buch, Ronak; Kale, Laxmikant V.] Univ Illinois, Dept Comp Sci, Urbana, IL 61801 USA. [Isaacs, Katherine E.] Univ Calif Davis, Dept Comp Sci, Davis, CA 95616 USA. RP Bhatele, A (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. EM bhatele@llnl.gov; nikhil@illinois.edu; keisaacs@ucdavis.edu; rabuch2@illinois.edu; tgamblin@llnl.gov; langer1@llnl.gov; kale@illinois.edu FU U.S. Department of Energy by Lawrence Livermore National Laboratory [DE-AC52-07NA27344]; Laboratory Directed Research and Development Program at LLNL [13-ERD-055 (LLNL-CONF-655465)] FX This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. This work was funded by the Laboratory Directed Research and Development Program at LLNL under project tracking code 13-ERD-055 (LLNL-CONF-655465). NR 20 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1094-7256 BN 978-1-4799-5975-4 J9 INT C HIGH PERFORM PY 2014 PG 10 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BG9OY UT WOS:000393508400001 ER PT S AU Chavarria-Miranda, D Halappanavar, M Kalyanaraman, A AF Chavarria-Miranda, Daniel Halappanavar, Mahantesh Kalyanaraman, Ananth GP IEEE TI Scaling Graph Community Detection on the Tilera Many-core Architecture SO 2014 21ST INTERNATIONAL CONFERENCE ON HIGH PERFORMANCE COMPUTING (HIPC) SE International Conference on High Performance Computing LA English DT Proceedings Paper CT 21st International Conference on High Performance Computing (HiPC) CY DEC 17-20, 2014 CL Goa, INDIA DE Tilera; community detection; many-core; parallel graph algorithms AB In an era when power constraints and data movement are proving to be significant barriers for the application of high-end computing, the Tilera many-core architecture offers a low-power platform exhibiting many important characteristics of future systems, including a large number of simple cores, a sophisticated network-on-chip, and fine-grained control over memory and caching policies. While this emerging architecture has been previously studied for structured compute-intensive kernels, benchmarking the platform for data-bound, irregular applications present significant challenges that have remained unexplored. Community detection is an advanced prototypical graph-theoretic operation with applications in numerous scientific domains including life sciences, cyber security, and power systems. In this work, we explore multiple design strategies toward developing a scalable tool for community detection on the Tilera platform. Using several memory layout and work scheduling techniques we demonstrate speedups of up to 47x on 36 cores of the Tilera TileGX36 platform over the best serial implementation, and also show results that have comparable quality and performance to mainstream x86 platforms. To the best of our knowledge this is the first work addressing graph algorithms on the Tilera platform. This study demonstrates that through careful design space exploration, low-power many-core platforms like Tilera can be effectively exploited for graph algorithms that embody all the essential characteristics of an irregular application. C1 [Chavarria-Miranda, Daniel; Halappanavar, Mahantesh] Pacific Northwest Natl Lab, High Performance Comp, Richland, WA 99352 USA. [Kalyanaraman, Ananth] Washington State Univ, Sch Elect Engn & Comp Sci, Pullman, WA 99164 USA. RP Chavarria-Miranda, D (reprint author), Pacific Northwest Natl Lab, High Performance Comp, Richland, WA 99352 USA. EM daniel.chavarria@pnnl.gov; hala@pnnl.gov; ananth@eecs.wsu.edu FU DOE award [DE-SC-0006516]; Center for Adaptive Super Computing Software Multithreaded Architectures (CASS-MT) at the U.S. Department of Energy Pacific Northwest National Laboratory (PNNL); Battelle Memorial Institute [DE-AC06-76RL01830] FX The research was in part supported by DOE award DE-SC-0006516, and the Center for Adaptive Super Computing Software Multithreaded Architectures (CASS-MT) at the U.S. Department of Energy Pacific Northwest National Laboratory (PNNL). PNNL is operated by Battelle Memorial Institute under Contract DE-AC06-76RL01830. NR 24 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1094-7256 BN 978-1-4799-5975-4 J9 INT C HIGH PERFORM PY 2014 PG 11 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BG9OY UT WOS:000393508400003 ER PT S AU Childs, H Biersdorff, S Poliakoff, D Camp, D Malony, AD AF Childs, Hank Biersdorff, Scott Poliakoff, David Camp, David Malony, Allen D. GP IEEE TI Particle Advection Performance Over Varied Architectures and Workloads SO 2014 21ST INTERNATIONAL CONFERENCE ON HIGH PERFORMANCE COMPUTING (HIPC) SE International Conference on High Performance Computing LA English DT Proceedings Paper CT 21st International Conference on High Performance Computing (HiPC) CY DEC 17-20, 2014 CL Goa, INDIA DE GPGPU; Hybrid Parallelism; Flow Visualization; Performance Analysis ID GENERATION; FIELDS AB Particle advection is a foundational operation for many flow visualization techniques, including streamlines, Finite-Time Lyapunov Exponents (FTLE) calculation, and stream surfaces. The workload for particle advection problems varies greatly, including significant variation in computational requirements. With this study, we consider the performance impacts from hardware architecture on this problem, studying distributed-memory systems with CPUs with varying amounts of cores per node, and with nodes with one to three GPUs. Our goal was to explore which architectures were best suited to which workloads, and why. While the results of this study will help inform visualization scientists which architectures they should use when solving certain flow visualization problems, it is also informative for the larger HPC community, since many simulation codes will soon incorporate visualization via in situ techniques. C1 [Childs, Hank; Biersdorff, Scott; Poliakoff, David; Malony, Allen D.] Univ Oregon, Eugene, OR 97403 USA. [Childs, Hank; Camp, David] Lawrence Berkeley Natl Lab, Berkeley, CA USA. RP Childs, H (reprint author), Univ Oregon, Eugene, OR 97403 USA. FU U.S. Department of Energy [DE-AC02-05CH11231]; National Science Foundation [OCI-0910735]; Office of Science of the U.S. Department of Energy [DE-AC02-05CH11231, DE-AC05-00OR22725]; National Science Foundation, Office of Cyber Infrastructure, "MRI-R2: Acquisition of an Applied Computational Instrument for Scientific Synthesis (ACISS)" [OCI-0960354] FX This work was supported by the Director, Office of Advanced Scientific Computing Research, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.; The study used many machines. The research used resources of the Keeneland Computing Facility at the Georgia Institute of Technology, which is supported by the National Science Foundation under Contract OCI-0910735. It used resources 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-AC02-05CH11231. It used resources of the Oak Ridge Leadership Computing Facility at the 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. The research was supported by a Major Research Instrumentation grant from the National Science Foundation, Office of Cyber Infrastructure, "MRI-R2: Acquisition of an Applied Computational Instrument for Scientific Synthesis (ACISS)," Grant OCI-0960354. (Note that many predecessor runs occurred on these machines, although none appear in our results section.) NR 27 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1094-7256 BN 978-1-4799-5975-4 J9 INT C HIGH PERFORM PY 2014 PG 10 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BG9OY UT WOS:000393508400035 ER PT S AU Daily, J Vishnu, A Palmer, B van Dam, H Kerbyson, D AF Daily, Jeff Vishnu, Abhinav Palmer, Bruce van Dam, Hubertus Kerbyson, Darren GP IEEE TI On the Suitability of MPI as a PGAS Runtime SO 2014 21ST INTERNATIONAL CONFERENCE ON HIGH PERFORMANCE COMPUTING (HIPC) SE International Conference on High Performance Computing LA English DT Proceedings Paper CT 21st International Conference on High Performance Computing (HiPC) CY DEC 17-20, 2014 CL Goa, INDIA ID HIGH-PERFORMANCE; MODEL AB Partitioned Global Address Space (PGAS) models are emerging as a popular alternative to MPI models for designing scalable applications. At the same time, MPI remains a ubiquitous communication subsystem due to its standardization, high performance, and availability on leading platforms. In this paper, we explore the suitability of using MPI as a scalable PGAS communication subsystem. We focus on the Remote Memory Access (RMA) communication in PGAS models which typically includes get, put, and atomic memory operations. We perform an in-depth exploration of design alternatives based on MPI. These alternatives include using a semantically-matching interface such as MPI-RMA, as well as not-so-intuitive interfaces such as MPI two-sided with a combination of multi-threading and dynamic process management. With an in-depth exploration of these alternatives and their shortcomings, we propose a novel design which is facilitated by the data-centric view in PGAS models. This design leverages a combination of highly tuned MPI twosided semantics and an automatic, user-transparent split of MPI communicators to provide asynchronous progress. We implement the asynchronous progress ranks approach and other approaches within the Communication Runtime for Exascale which is a communication subsystem for Global Arrays. Our performance evaluation spans pure communication benchmarks, graph community detection and sparse matrix-vector multiplication kernels, and a computational chemistry application. The utility of our proposed PR-based approach is demonstrated by a 2.17x speedup on 1008 processors over the other MPI-based designs. C1 [Daily, Jeff; Vishnu, Abhinav; Palmer, Bruce; van Dam, Hubertus; Kerbyson, Darren] Pacific Northwest Natl Lab, 902 Battelle Blvd, Richland, WA 99352 USA. RP Daily, J (reprint author), Pacific Northwest Natl Lab, 902 Battelle Blvd, Richland, WA 99352 USA. EM Jeff.Daily@pnnl.gov; Abhinav.Vishnu@pnnl.gov; Bruce.Palmer@pnnl.gov; HubertusJJ.vanDam@pnnl.gov; Darren.Kerbyson@pnnl.gov FU U.S. Department of Energy (DoE) Office of Science (OS), Office of Advanced Scientific Computing Research; eXtreme Scale Computing Initiative of Pacific Northwest National Laboratory [DE-AC05-76RL01830]; OS [DE-AC02-05CH11231] FX This material is based upon work performed under the Performance Health Monitoring for Large-Scale Systems project, supported by the U.S. Department of Energy (DoE) Office of Science (OS), Office of Advanced Scientific Computing Research. Additional support was provided by the eXtreme Scale Computing Initiative (http://xsci.pnnl.gov) of Pacific Northwest National Laboratory operated by Battelle for DoE under Contract DE-AC05-76RL01830. This research used resources of the National Energy Research Scientific Computing Center, which is supported by OS under Contract No. DE-AC02-05CH11231. NR 26 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1094-7256 BN 978-1-4799-5975-4 J9 INT C HIGH PERFORM PY 2014 PG 10 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BG9OY UT WOS:000393508400007 ER PT S AU Ibrahim, KZ Williams, SW Epifanovsky, E Krylov, AI AF Ibrahim, Khaled Z. Williams, Samuel W. Epifanovsky, Evgeny Krylov, Anna I. GP IEEE TI Analysis and Tuning of Libtensor Framework on Multicore Architectures SO 2014 21ST INTERNATIONAL CONFERENCE ON HIGH PERFORMANCE COMPUTING (HIPC) SE International Conference on High Performance Computing LA English DT Proceedings Paper CT 21st International Conference on High Performance Computing (HiPC) CY DEC 17-20, 2014 CL Goa, INDIA DE tensor algebra; parallel programming; quantum chemistry software ID COUPLED-CLUSTER; IMPLEMENTATION; ENGINE AB Libtensor is a framework designed to implement the tensor contractions arising form the coupled cluster and equations of motion computational quantum chemistry equations. It has been optimized for symmetry and sparsity to be memory efficient. This allows it to run efficiently on the ubiquitous and cost-effective SMP architectures. Unfortunately, movement of memory controllers on chip has endowed these SMP systems with strong NUMA properties. Moreover, the manycore trend in processor architecture demands that the implementation be extremely thread-scalable on node. To date, Libtensor has been generally agnostic of these effects. To that end, in this paper, we explore a number of optimization techniques including a thread-friendly and NUMA-aware memory allocator and garbage collector, tuning the tensor tiling factor, and tuning the scheduling quanta. In the end, our optimizations can improve the performance of contractions implemented in Libtensor by up to 2x on representative Ivy Bridge, Nehalem, and Opteron SMPs. C1 [Ibrahim, Khaled Z.; Williams, Samuel W.] Lawrence Berkeley Natl Lab, Computat Res Div, Berkeley, CA 94720 USA. [Epifanovsky, Evgeny; Krylov, Anna I.] Univ Southern Calif, Dept Chem, Los Angeles, CA 90089 USA. RP Ibrahim, KZ (reprint author), Lawrence Berkeley Natl Lab, Computat Res Div, Berkeley, CA 94720 USA. EM kzibrahim@lbl.gov; swwilliams@lbl.gov; epifanov@usc.edu; krylov@usc.edu FU U.S. Department of Energy Office of Science's Advanced Scientific Computing Research program [DE-AC02-05CH11231]; U.S. Department of Energy, Office of Science, Office of Advanced Scientific Computing Research, Scientific Discovery through Advanced Computing (SciDAC) program FX This research used resources in Lawrence Berkeley National Laboratory and the National Energy Research Scientific Computing Center, which are supported by the U.S. Department of Energy Office of Science's Advanced Scientific Computing Research program under contract number DE-AC02-05CH11231. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Advanced Scientific Computing Research, Scientific Discovery through Advanced Computing (SciDAC) program. 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 SN 1094-7256 BN 978-1-4799-5975-4 J9 INT C HIGH PERFORM PY 2014 PG 10 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BG9OY UT WOS:000393508400016 ER PT S AU Chow, WW Jahnke, F Gies, C AF Chow, W. W. Jahnke, F. Gies, C. GP IEEE Comp Soc TI Searching for lasing threshold in a thresholdless laser SO 2014 24TH IEEE INTERNATIONAL SEMICONDUCTOR LASER CONFERENCE (ISLC 2014) SE IEEE International Semiconductor Laser Conference LA English DT Proceedings Paper CT 24th IEEE International Semiconductor Laser Conference (ISLC) CY SEP 07-10, 2014 CL Palma de Mallorca, SPAIN SP IEEE AB A quantum-optical model is applied to address the question of criteria for lasing in a thresholdless laser where the intensity jump, customarily used to indicate transition to lasing, is missing. C1 [Chow, W. W.] Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. [Jahnke, F.; Gies, C.] Univ Bremen, Inst Theoret Phys, D-28334 Bremen, Germany. RP Chow, WW (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM wwchow@sandia.gov; jahnke@itp.uni-bremen.de; gies@itp.uni-bremen.de NR 1 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 SN 2326-5442 BN 978-1-4799-5721-7 J9 IEEE INT SEMICONDUCT PY 2014 BP 219 EP 220 DI 10.1109/ISLC.2014.55 PG 2 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BE2SW UT WOS:000369990800110 ER PT S AU Aguilar, RV Qi, J Brahlek, M Bansal, N Azad, A Oh, S Taylor, AJ Prasankumar, RP Yarotski, DA AF Aguilar, R. Valdes Qi, J. Brahlek, M. Bansal, N. Azad, A. Oh, S. Taylor, A. J. Prasankumar, R. P. Yarotski, D. A. GP IEEE TI Time-resolved THz dynamics in thin films of Bi2Se3 SO 2014 39TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ) SE International Conference on Infrared Millimeter and Terahertz Waves LA English DT Proceedings Paper CT 39th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) CY SEP 14-19, 2014 CL Tucson, AZ SP THORLABS, Tydex, TOPTICA Photon, Bruker, Gentec EO, Lake Shore Cryotron, Ekspla, Zomega, TeraSense, Insight Product, Emcore, QMC Instruments, TeraView, NeaSpec, Advantest, MenloSystems, Traycer, Microtech Instruments Inc, LongWave Photon, Virginia Diodes Inc, ASU, MTT S, Journal Infrared Millimeter & Tera Hertz Waves, Tera Hertz Sci & Technol, Army Res Off ID TOPOLOGICAL INSULATORS AB Topological insulators represent a new state of flatter where bulk insulators exhibit metallic surfaces that are protected by time reversal symmetry. However, in common transport measurements residual hulk conductivity hinders the properties of the topologically protected surfaces. Alternatively, terahertz spectroscopy has recently been shown to be capable of discerning the bulk and surface carrier conductivity. Here we use time-resolved optical pump-THz probe spectroscopy at low temperatures to study the hot carrier response of thin films of Bi2Se3 of several thicknesses and separate the bulk from the surface response. We find that for thinner films the photo excitation changes the transport scattering rate and reduces the surface conductivity. For thicker films, this process competes with the photoinduced increase in bulk conductivity, which occurs on shorter timescales and scales with the increase in both the film thickness and optical excitation fluence. These different dynamics of the surface and bulk electrons indicate a decoupling of surface and bulk carriers, and present the possibility of accessing long-lived surface photo-carriers for optoelectronic applications. C1 [Aguilar, R. Valdes; Qi, J.; Azad, A.; Taylor, A. J.; Prasankumar, R. P.; Yarotski, D. A.] Los Alamos Natl Lab, Ctr Integrated Nanotechnol, POB 1663, Los Alamos, NM 87545 USA. [Brahlek, M.; Bansal, N.; Oh, S.] Rutgers State Univ, Dept Phys & Astron, Piscataway, NJ 08854 USA. RP Aguilar, RV (reprint author), Los Alamos Natl Lab, Ctr Integrated Nanotechnol, POB 1663, Los Alamos, NM 87545 USA. 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 2162-2027 BN 978-1-4799-3877-3 J9 INT CONF INFRA MILLI PY 2014 PG 2 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BF0IL UT WOS:000378889200074 ER PT S AU Antipov, S Jing, CG Kanareykin, A Fedurin, M Yakimenko, V Gai, W Zholents, A AF Antipov, Sergey Jing, Chunguang Kanareykin, Alexei Fedurin, Mikhail Yakimenko, Vitaly Gai, Wei Zholents, Alexander GP IEEE TI High Power Terahertz Radiation Source Based on Electron Beam Wakefields SO 2014 39TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ) SE International Conference on Infrared Millimeter and Terahertz Waves LA English DT Proceedings Paper CT 39th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) CY SEP 14-19, 2014 CL Tucson, AZ SP THORLABS, Tydex, TOPTICA Photon, Bruker, Gentec EO, Lake Shore Cryotron, Ekspla, Zomega, TeraSense, Insight Product, Emcore, QMC Instruments, TeraView, NeaSpec, Advantest, MenloSystems, Traycer, Microtech Instruments Inc, LongWave Photon, Virginia Diodes Inc, ASU, MTT S, Journal Infrared Millimeter & Tera Hertz Waves, Tera Hertz Sci & Technol, Army Res Off AB A table top device for producing high power T-ray beams is described. An electron beam with a rectangular longitudinal profile is produced out of a photoinjector via stacking of the laser pulses. The beam is also run off-crest of the photoinjector rf to develop an energy chirp. After passing through a dielectric loaded waveguide, the beam's energy becomes modulated by its self-wake. In a chicane beamline following the dielectric energy-bunching section this energy modulation is converted to a density modulation-- a bunch train. The density modulated beam can be sent through a power extraction section, like a dielectric loaded accelerating structure, or simply can intercept a foil target, producing THz radiation of various bandwidths and power levels. C1 [Antipov, Sergey; Jing, Chunguang; Kanareykin, Alexei] Euclid Techlabs LLC, Solon, OH 44139 USA. [Fedurin, Mikhail] Brookhaven Natl Lab, Upton, NY 11973 USA. [Antipov, Sergey; Jing, Chunguang; Gai, Wei; Zholents, Alexander] Argonne Natl Lab, Lemont, IL 60439 USA. [Yakimenko, Vitaly] SLAC Natl Accelerator Lab, Menlo Pk, CA 94025 USA. RP Antipov, S (reprint author), Euclid Techlabs LLC, Solon, OH 44139 USA. 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 2162-2027 BN 978-1-4799-3877-3 J9 INT CONF INFRA MILLI PY 2014 PG 2 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BF0IL UT WOS:000378889200202 ER PT S AU Grady, N Heyes, JE Chowdhury, DR Zeng, Y Reiten, MT Azad, AK Taylor, AJ Dalvit, DAR Chen, HT AF Grady, Nathaniel Heyes, Jane E. Chowdhury, Dibakar Roy Zeng, Yong Reiten, Matthew T. Azad, Abul K. Taylor, Antoinette J. Dalvit, Diego A. R. Chen, Hou-Tong GP IEEE TI Efficient Metamaterial Flat Lenses SO 2014 39TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ) SE International Conference on Infrared Millimeter and Terahertz Waves LA English DT Proceedings Paper CT 39th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) CY SEP 14-19, 2014 CL Tucson, AZ SP THORLABS, Tydex, TOPTICA Photon, Bruker, Gentec EO, Lake Shore Cryotron, Ekspla, Zomega, TeraSense, Insight Product, Emcore, QMC Instruments, TeraView, NeaSpec, Advantest, MenloSystems, Traycer, Microtech Instruments Inc, LongWave Photon, Virginia Diodes Inc, ASU, MTT S, Journal Infrared Millimeter & Tera Hertz Waves, Tera Hertz Sci & Technol, Army Res Off ID REFRACTION AB We recently demonstrated ultrathin, broadband, and highly efficient (reaching 88%) terahertz (THz) metamaterial structures exhibiting near-perfect anomalous (or generalized laws of) refraction. These structures redirect up to 61% of the incident power into the anomalous beam and practically eliminate the ordinary component. Here exploit this breakthrough to create more complex optical elements, specifically a highly efficient metamaterial flat lens. C1 [Grady, Nathaniel; Heyes, Jane E.; Chowdhury, Dibakar Roy; Zeng, Yong; Reiten, Matthew T.; Azad, Abul K.; Taylor, Antoinette J.; Dalvit, Diego A. R.; Chen, Hou-Tong] Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RP Grady, N (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2162-2027 BN 978-1-4799-3877-3 J9 INT CONF INFRA MILLI PY 2014 PG 2 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BF0IL UT WOS:000378889200221 ER PT S AU Gutin, A Muraviev, AV Kamaraju, N Shen, X Yamaguchi, Y Shur, MS But, D Dyakonova, N Knap, W Rudin, S Rupper, G AF Gutin, A. Muraviev, A. V. Kamaraju, N. Shen, X. Yamaguchi, Y. Shur, M. S. But, D. Dyakonova, N. Knap, W. Rudin, S. Rupper, G. GP IEEE TI Application of Plasma-Wave Detectors for Ultra-Short Pulse Terahertz Radiation SO 2014 39TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ) SE International Conference on Infrared Millimeter and Terahertz Waves LA English DT Proceedings Paper CT 39th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) CY SEP 14-19, 2014 CL Tucson, AZ SP THORLABS, Tydex, TOPTICA Photon, Bruker, Gentec EO, Lake Shore Cryotron, Ekspla, Zomega, TeraSense, Insight Product, Emcore, QMC Instruments, TeraView, NeaSpec, Advantest, MenloSystems, Traycer, Microtech Instruments Inc, LongWave Photon, Virginia Diodes Inc, ASU, MTT S, Journal Infrared Millimeter & Tera Hertz Waves, Tera Hertz Sci & Technol, Army Res Off AB We demonstrate detection of individual pulses of terahertz radiation generated in femtosecond laser systems by InGaAs plasma-wave terahertz detectors. Nonlinearity of the detection mechanism is analyzed experimentally by comparison of saturation effects at femtosecond and nanosecond terahertz excitations. Good sensitivity and wide dynamic range make these detectors promising for short-pulsed terahertz applications. C1 [Gutin, A.; Muraviev, A. V.; Kamaraju, N.; Shen, X.; Yamaguchi, Y.; Shur, M. S.] Rensselaer Polytech Inst, Troy, NY 12180 USA. [Kamaraju, N.] Los Alamos Natl Lab, Ctr Integrated Nanotechnol, Los Alamos, NM 87545 USA. [But, D.; Dyakonova, N.; Knap, W.] Univ Montpellier, F-34059 Montpellier, France. [Rudin, S.; Rupper, G.] US Army, Res Lab, Adelphi, MD 20783 USA. RP Gutin, A (reprint author), Rensselaer Polytech Inst, Troy, NY 12180 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2162-2027 BN 978-1-4799-3877-3 J9 INT CONF INFRA MILLI PY 2014 PG 2 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BF0IL UT WOS:000378889200467 ER PT S AU Heyes, JE Withayachumnankul, W Azad, AK Chowdhury, DR Grady, NK Chen, HT AF Heyes, Jane E. Withayachumnankul, Withawat Azad, Abul K. Chowdhury, Dibakar Roy Grady, Nathaniel K. Chen, Hou-Tong GP IEEE TI Ultra-Broadband Terahertz Modulation by Active Hybrid Metamaterials SO 2014 39TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ) SE International Conference on Infrared Millimeter and Terahertz Waves LA English DT Proceedings Paper CT 39th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) CY SEP 14-19, 2014 CL Tucson, AZ SP THORLABS, Tydex, TOPTICA Photon, Bruker, Gentec EO, Lake Shore Cryotron, Ekspla, Zomega, TeraSense, Insight Product, Emcore, QMC Instruments, TeraView, NeaSpec, Advantest, MenloSystems, Traycer, Microtech Instruments Inc, LongWave Photon, Virginia Diodes Inc, ASU, MTT S, Journal Infrared Millimeter & Tera Hertz Waves, Tera Hertz Sci & Technol, Army Res Off AB We demonstrate an ultra-broadband all-optical terahertz modulator based on a semiconductor-integrated hybrid metamaterial. Under photoexcitation using near-infrared laser pulses, the semiconductor regions become highly conducting, causing a transition of the metamaterial from an array of dipole patch grid to a metal wire grating. This transition exhibits dramatically different transmission properties and enables a broadband modulation of terahertz waves. The concept may be further extended to electrically switchable terahertz metamaterials. C1 [Heyes, Jane E.; Azad, Abul K.; Chowdhury, Dibakar Roy; Grady, Nathaniel K.; Chen, Hou-Tong] Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. [Withayachumnankul, Withawat] Univ Adelaide, Adelaide, SA 5005, Australia. RP Heyes, JE (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 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 SN 2162-2027 BN 978-1-4799-3877-3 J9 INT CONF INFRA MILLI PY 2014 PG 2 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BF0IL UT WOS:000378889200169 ER PT S AU Khudchenko, AV Hayton, DJ Pavelyev, DG Baryshev, AM Gao, JR Kao, TY Hu, Q Reno, JL Vaks, VL AF Khudchenko, A. V. Hayton, D. J. Pavelyev, D. G. Baryshev, A. M. Gao, J. R. Kao, T. -Y. Hu, Q. Reno, J. L. Vaks, V. L. GP IEEE TI Phase Locking a 4.7 THz Quantum Cascade Laser using a Super-Lattice Diode as Harmonic Mixer SO 2014 39TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ) SE International Conference on Infrared Millimeter and Terahertz Waves LA English DT Proceedings Paper CT 39th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) CY SEP 14-19, 2014 CL Tucson, AZ SP THORLABS, Tydex, TOPTICA Photon, Bruker, Gentec EO, Lake Shore Cryotron, Ekspla, Zomega, TeraSense, Insight Product, Emcore, QMC Instruments, TeraView, NeaSpec, Advantest, MenloSystems, Traycer, Microtech Instruments Inc, LongWave Photon, Virginia Diodes Inc, ASU, MTT S, Journal Infrared Millimeter & Tera Hertz Waves, Tera Hertz Sci & Technol, Army Res Off AB We have phase locked a 4.7 THz Quantum Cascade Laser (QCL) to a stable microwave reference signal. The QCL is a 3rd order distributed feedback (DFB) laser with a low power consumption of 0.5 W and radiation power of about 0.25 mW. One of the key elements in our experimental setup is a super lattice diode operating as a harmonic mixer and providing the beat signal between the QCL and the 24th harmonic of a 198 GHz reference signal. A phase locked beat signal is about 20 dB above the noise level for a 30 KHz resolution bandwidth. C1 [Khudchenko, A. V.; Hayton, D. J.; Baryshev, A. M.; Gao, J. R.] SRON Netherlands Inst Space Res, Utrecht, Netherlands. [Pavelyev, D. G.] Nizhnii Novgorod State Univ, Radiophys dept, Nizhnii Novgorod, Russia. [Baryshev, A. M.] NOVA Kapteyn Astron Inst, Groningen, Netherlands. [Gao, J. R.] Delft Univ Technol, Kavli Inst Nanosci, NL-2600 AA Delft, Netherlands. [Kao, T. -Y.; Hu, Q.] MIT, Dept Elect Engn & Comp Sci, Cambridge, MA 02139 USA. [Reno, J. L.] Sandia Natl Labs, Albuquerque, NM 87185 USA. [Vaks, V. L.] Russian Acad Sci, Inst Phys Microstruct, Nizhnii Novgorod 603950, Russia. RP Khudchenko, AV (reprint author), SRON Netherlands Inst Space Res, Utrecht, Netherlands. NR 7 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2162-2027 BN 978-1-4799-3877-3 J9 INT CONF INFRA MILLI PY 2014 DI 10.1109/IRMMW-THz.2014.6956455 PG 2 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BF0IL UT WOS:000378889200462 ER PT S AU Kotelnikov, IA Stupakov, GV AF Kotelnikov, Igor A. Stupakov, Gennady V. GP IEEE TI Paraxial equation for the surface wave on a conducting cylinder SO 2014 39TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ) SE International Conference on Infrared Millimeter and Terahertz Waves LA English DT Proceedings Paper CT 39th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) CY SEP 14-19, 2014 CL Tucson, AZ SP THORLABS, Tydex, TOPTICA Photon, Bruker, Gentec EO, Lake Shore Cryotron, Ekspla, Zomega, TeraSense, Insight Product, Emcore, QMC Instruments, TeraView, NeaSpec, Advantest, MenloSystems, Traycer, Microtech Instruments Inc, LongWave Photon, Virginia Diodes Inc, ASU, MTT S, Journal Infrared Millimeter & Tera Hertz Waves, Tera Hertz Sci & Technol, Army Res Off ID METAL-DIELECTRIC INTERFACE; DISPERSION-RELATION AB We derive a reduced wave equation for the surface waves on an air-metal interface with a given radius of curvature R. Using the Leontovich boundary condition with a small dimensionless surface impedance we find solutions to this equation in terms of the Airy-Fock functions. A relation between the surface waves on a planar and cylindrical metal-air interfaces is elucidated and the dispersion relation of a planar surface wave is recovered as the limit of a sufficiently large curvature radius R. C1 [Kotelnikov, Igor A.] Budker Inst Nucl Phys SB RAS, Novosibirsk 630090, Russia. [Kotelnikov, Igor A.] Novosibirsk State Univ, Novosibirsk 630090, Russia. [Stupakov, Gennady V.] Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Kotelnikov, IA (reprint author), Budker Inst Nucl Phys SB RAS, Novosibirsk 630090, Russia. 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 SN 2162-2027 BN 978-1-4799-3877-3 J9 INT CONF INFRA MILLI PY 2014 PG 1 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BF0IL UT WOS:000378889200405 ER PT S AU Mitrofanov, O Dominec, F Navarro-Cia, M Kuzel, P Reno, JL Brener, I Mounaix, P AF Mitrofanov, O. Dominec, F. Navarro-Cia, M. Kuzel, P. Reno, J. L. Brener, I. Mounaix, P. GP IEEE TI Near-field probing of the THz Mie magnetic mode in a single sub-wavelength TiO2 sphere SO 2014 39TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ) SE International Conference on Infrared Millimeter and Terahertz Waves LA English DT Proceedings Paper CT 39th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) CY SEP 14-19, 2014 CL Tucson, AZ SP THORLABS, Tydex, TOPTICA Photon, Bruker, Gentec EO, Lake Shore Cryotron, Ekspla, Zomega, TeraSense, Insight Product, Emcore, QMC Instruments, TeraView, NeaSpec, Advantest, MenloSystems, Traycer, Microtech Instruments Inc, LongWave Photon, Virginia Diodes Inc, ASU, MTT S, Journal Infrared Millimeter & Tera Hertz Waves, Tera Hertz Sci & Technol, Army Res Off AB We report the first investigation of single Titanium Dioxide (TiO2) sub-wavelength size (20-30 mu m) spheres and ellipsoids using THz near-field microscopy. The Mie resonances are observed in individual particles allowing characterization of the resonance line-width and its dependence on the particle dimensions and shape. C1 [Mitrofanov, O.] UCL, London WC1E 7JE, England. [Mitrofanov, O.; Navarro-Cia, M.; Reno, J. L.; Brener, I.] Sandia Natl Labs, Ctr Integrated Nanotechnol, Albuquerque, NM 87185 USA. [Dominec, F.; Kuzel, P.; Reno, J. L.; Brener, I.] ASCR, Inst Phys, Prague 18221, Czech Republic. [Navarro-Cia, M.] Univ London Imperial Coll Sci Technol & Med, London, England. Sandia Natl Labs, Albuquerque, NM 87185 USA. [Mounaix, P.] Univ Bordeaux, CNRS, UMR 5798, LOMA, F-33495 Talence, France. RP Mitrofanov, O (reprint author), UCL, London WC1E 7JE, England. RI Kuzel, Petr/G-6006-2014; Navarro-Cia, Miguel/L-4517-2013; Mitrofanov, Oleg/C-1938-2008 OI Navarro-Cia, Miguel/0000-0003-0256-6465; Mitrofanov, Oleg/0000-0003-3510-2675 NR 3 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2162-2027 BN 978-1-4799-3877-3 J9 INT CONF INFRA MILLI PY 2014 PG 2 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BF0IL UT WOS:000378889200349 ER PT S AU Palm, A Shin, YM AF Palm, Andrew Shin, Young-Min GP IEEE TI Traveling Wave Amplification from Multi-Beam Slow Wave Structures for High Power Millimeter and THz Wave Generation SO 2014 39TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ) SE International Conference on Infrared Millimeter and Terahertz Waves LA English DT Proceedings Paper CT 39th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) CY SEP 14-19, 2014 CL Tucson, AZ SP THORLABS, Tydex, TOPTICA Photon, Bruker, Gentec EO, Lake Shore Cryotron, Ekspla, Zomega, TeraSense, Insight Product, Emcore, QMC Instruments, TeraView, NeaSpec, Advantest, MenloSystems, Traycer, Microtech Instruments Inc, LongWave Photon, Virginia Diodes Inc, ASU, MTT S, Journal Infrared Millimeter & Tera Hertz Waves, Tera Hertz Sci & Technol, Army Res Off AB In an effort to develop compact millimeter and THz wave radiation power sources, two types of traveling wave amplification concept with multi-beam have been studied using Pierce small signal analysis and particle-in-cell (PIC) simulation. Our prior work includes theoretical and numerical assessment on performance of the aluminum-nitride (AlN)-loaded multi-beam structure, indicating that the TM31-mode is amplified with 26 - 30 dB/beam at 64 - 84 GHz with three elliptical beams, simultaneously suppressing lower order modes (TM11, and TM21). The same analysis also shows that multi-staged cascading enables > 50 W of radiation power with 30 dB gain, which could be integrated on a single board substrate with multi-beam emitters by micro-fabrication. More schemes to improve device performance and to reduce physical sizes are continuously explored in advancing millimeter and sub-millimeter power radiation sources. C1 [Palm, Andrew; Shin, Young-Min] No Illinois Univ, Dept Phys, Northern Illinois Ctr Accelerator & Detector Dev, De Kalb, IL 60115 USA. [Shin, Young-Min] Fermilab Natl Accelerator Lab, Accelerator Phys Ctr, POB 500, Batavia, IL 60510 USA. RP Palm, A (reprint author), No Illinois Univ, Dept Phys, Northern Illinois Ctr Accelerator & Detector Dev, De Kalb, IL 60115 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2162-2027 BN 978-1-4799-3877-3 J9 INT CONF INFRA MILLI PY 2014 PG 1 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BF0IL UT WOS:000378889200111 ER PT S AU Saykally, RJ AF Saykally, Richard J. GP IEEE TI Terahertz Spectroscopy of Water Clusters SO 2014 39TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ) SE International Conference on Infrared Millimeter and Terahertz Waves LA English DT Proceedings Paper CT 39th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) CY SEP 14-19, 2014 CL Tucson, AZ SP THORLABS, Tydex, TOPTICA Photon, Bruker, Gentec EO, Lake Shore Cryotron, Ekspla, Zomega, TeraSense, Insight Product, Emcore, QMC Instruments, TeraView, NeaSpec, Advantest, MenloSystems, Traycer, Microtech Instruments Inc, LongWave Photon, Virginia Diodes Inc, ASU, MTT S, Journal Infrared Millimeter & Tera Hertz Waves, Tera Hertz Sci & Technol, Army Res Off C1 [Saykally, Richard J.] Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. [Saykally, Richard J.] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Saykally, RJ (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM saykally@berkeley.edu 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 SN 2162-2027 BN 978-1-4799-3877-3 J9 INT CONF INFRA MILLI PY 2014 PG 2 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BF0IL UT WOS:000378889200157 ER PT S AU Shin, YM Xu, T Palm, A Zhu, X Broemmelsiek, D Thangaraj, J Thurman-Keup, R Lumpkin, A AF Shin, Y. M. Xu, T. Palm, A. Zhu, X. Broemmelsiek, D. Thangaraj, J. Thurman-Keup, R. Lumpkin, A. GP IEEE TI THz-Wakefield Generation by Modulated Electron Beams Resonating with Crystalline Plasma Channels SO 2014 39TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ) SE International Conference on Infrared Millimeter and Terahertz Waves LA English DT Proceedings Paper CT 39th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) CY SEP 14-19, 2014 CL Tucson, AZ SP THORLABS, Tydex, TOPTICA Photon, Bruker, Gentec EO, Lake Shore Cryotron, Ekspla, Zomega, TeraSense, Insight Product, Emcore, QMC Instruments, TeraView, NeaSpec, Advantest, MenloSystems, Traycer, Microtech Instruments Inc, LongWave Photon, Virginia Diodes Inc, ASU, MTT S, Journal Infrared Millimeter & Tera Hertz Waves, Tera Hertz Sci & Technol, Army Res Off ID ACCELERATOR AB We have been investigating THz photon emission/absorption dynamics of high energy electrons channeled through crystalline nanostructures. Preliminary plasma wakefield simulations, employing particle-in-cell (PIC) computations, indicated that a short-pulse (a 1 ps) electron beam, modulated with 28.4 THz, generates an intense plasmonic wave of 0.3 TeV/m in a plasma channel with a crystalline electronic density ( 1025 cm(3)). For experimental verification of the beam-driven THzwakefield generation, Au-plated and carbon nanotube (CNT)-embedded anodic aluminum-oxide (AAO) templates are being considered for the high energy beam tests (20 50 MeV and 3.2 nC) with 3 THz modulation, at the Fermilab Advanced Superconducting Test Accelerator (ASTA) facility. C1 [Shin, Y. M.; Palm, A.] No Illinois Univ, Dept Phys, Northern Illinois Ctr Accelerator & Detector Dev, De Kalb, IL 60115 USA. [Shin, Y. M.; Broemmelsiek, D.; Thangaraj, J.; Thurman-Keup, R.; Lumpkin, A.] Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. [Xu, T.] No Illinois Univ, Dept Chem & Biochem, De Kalb, IL 60115 USA. [Zhu, X.] Univ Elect Sci & Technol China, Sch Phys Elect, Chengdu 610054, Peoples R China. RP Shin, YM (reprint author), No Illinois Univ, Dept Phys, Northern Illinois Ctr Accelerator & Detector Dev, De Kalb, IL 60115 USA. 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 2162-2027 BN 978-1-4799-3877-3 J9 INT CONF INFRA MILLI PY 2014 PG 2 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BF0IL UT WOS:000378889200274 ER PT S AU Shin, YM Palm, A Zhu, X AF Shin, Y. M. Palm, A. Zhu, X. GP IEEE TI Photonic-Band-Gap (PBG) and Metamaterial RF-Structures for High Power Millimeter and THz Wave Electron Beam Devices SO 2014 39TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER, AND TERAHERTZ WAVES (IRMMW-THZ) SE International Conference on Infrared Millimeter and Terahertz Waves LA English DT Proceedings Paper CT 39th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) CY SEP 14-19, 2014 CL Tucson, AZ SP THORLABS, Tydex, TOPTICA Photon, Bruker, Gentec EO, Lake Shore Cryotron, Ekspla, Zomega, TeraSense, Insight Product, Emcore, QMC Instruments, TeraView, NeaSpec, Advantest, MenloSystems, Traycer, Microtech Instruments Inc, LongWave Photon, Virginia Diodes Inc, ASU, MTT S, Journal Infrared Millimeter & Tera Hertz Waves, Tera Hertz Sci & Technol, Army Res Off ID REFRACTION AB Novel photonic band gap (PBG) waveguides and metamaterial (MM) cavities have been designed in the effort to develop high power millimeter and THz sources. The designed structures are comprised of a periodically corrugated channel sandwiched between two PBG slabs and a multi-cell cavity-resonator designed with fishnet apertures. The simulation analysis shows that trapped non-PBG modes are effectively suppressed down to similar to-14.3 dB/cm, while PBG modes propagated with 2 dB of insertion loss, corresponding to similar to 1.14 dB/cm attenuation. The preliminary modeling analysis on the fishnet-embedded cavity shows noticeable improvement of Q-factor and field gradient of the operating mode (TM010) compared to those of typical pillbox- or PBG-cavities. The Ka-band PBG-waveguide and S-band fishnet cavity structures will be tested with a microwave test bench/8510C Network Analyzer and 5.5 MW S-band klystron. These structures can be applied to stable short-bunch formation and mono-energetic radiation in high frequency electron beam devices. C1 [Shin, Y. M.; Palm, A.] No Illinois Univ, Dept Phys, Northern Illinois Ctr Accelerator & Detector Dev, De Kalb, IL 60115 USA. [Shin, Y. M.] Fermilab Natl Accelerator Lab, Accelerator Phys Ctr, Batavia, IL 60510 USA. [Zhu, X.] Univ Elect Sci & Technol China, Sch Phys Elect, Chengdu 610054, Peoples R China. RP Shin, YM (reprint author), No Illinois Univ, Dept Phys, Northern Illinois Ctr Accelerator & Detector Dev, De Kalb, IL 60115 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2162-2027 BN 978-1-4799-3877-3 J9 INT CONF INFRA MILLI PY 2014 PG 2 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BF0IL UT WOS:000378889200250 ER PT S AU Maheshwari, K Jung, ES Meng, JY Vishwanath, V Kettimuthu, R AF Maheshwari, Ketan Jung, Eun-Sung Meng, Jiayuan Vishwanath, Venkatram Kettimuthu, Rajkumar GP IEEE TI Improving Multisite Workflow Performance using Model-based Scheduling SO 2014 43RD INTERNATIONAL CONFERENCE ON PARALLEL PROCESSING (ICPP) SE Proceedings of the International Conference on Parallel Processing LA English DT Proceedings Paper CT 43rd Annual International Conference on Parallel Processing (ICPP) CY SEP 09-12, 2014 CL Minneapolis, MN SP IEEE Comp Soc, Univ Minnesota, Int Assoc Comp & Commun AB Workflows play an important role in expressing and executing scientific applications. In recent years, a variety of computational sites and resources have emerged, and users often have access to multiple resources that are geographically distributed. These computational sites are heterogeneous in nature and performance of different tasks in a workflow varies from one site to another. Additionally, users typically have a limited resource allocation at each site. In such cases, judicious scheduling strategy is required in order to map tasks in the workflow to resources so that the workload is balanced among sites and the overhead is minimized in data transfer. Most existing systems either run the entire workflow in a single site or use naive approaches to distribute the tasks across sites or leave it to the user to optimize the allocation of tasks to distributed resources. This results in a significant loss in productivity for a scientist. In this paper, we propose a multi-site workflow scheduling technique that uses performance models to predict the execution time on different resources and dynamic probes to identify the achievable network throughput between sites. We evaluate our approach using real world applications in a distributed environment using the Swift distributed execution framework and show that our approach improves the execution time by up to 60% compared to the default schedule. C1 [Maheshwari, Ketan; Jung, Eun-Sung; Vishwanath, Venkatram; Kettimuthu, Rajkumar] Argonne Natl Lab, MCS Div, Argonne, IL 60439 USA. [Meng, Jiayuan; Vishwanath, Venkatram] Argonne Natl Lab, LCF Div, Argonne, IL 60439 USA. RP Maheshwari, K (reprint author), Argonne Natl Lab, MCS Div, Argonne, IL 60439 USA. FU U.S. Department of Energy, Office of Science, Advanced Scientific Computing Research [DE-AC02-06CH11357] FX We thank our colleague Victor Zavala for their collaboration on power application. We thank John Valdes from systems at Argonne for helping with computational resource access. We thank Gail Pieper of Argonne for proofreading help. This work was supported in part by the U.S. Department of Energy, Office of Science, Advanced Scientific Computing Research, under Contract DE-AC02-06CH11357. NR 39 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0190-3918 BN 978-1-4799-5618-0 J9 PROC INT CONF PARAL PY 2014 BP 131 EP 140 DI 10.1109/ICPP.2014.22 PG 10 WC Computer Science, Theory & Methods SC Computer Science GA BG9LY UT WOS:000393410400014 ER PT S AU Park, E Kartsaklis, C Cavazos, J AF Park, Eunjung Kartsaklis, Christos Cavazos, John GP IEEE TI HERCULES: Strong Patterns Towards More Intelligent Predictive Modeling SO 2014 43RD INTERNATIONAL CONFERENCE ON PARALLEL PROCESSING (ICPP) SE Proceedings of the International Conference on Parallel Processing LA English DT Proceedings Paper CT 43rd Annual International Conference on Parallel Processing (ICPP) CY SEP 09-12, 2014 CL Minneapolis, MN SP IEEE Comp Soc, Univ Minnesota, Int Assoc Comp & Commun DE compiler optimization; machine learning; predictive modeling; pattern-based program characterization AB Recent work has shown that program analysis techniques to select meaningful code features of programs are important in the task of deciding the best compiler optimizations. Although, there are many successful state-of-the-art program analysis techniques, they often do not provide a simple method to extract the most expressive information about loops, especially when a target program is computationally intensive with complex loops and data dependencies. In this paper, we introduce a static technique to characterize a program using a pattern-driven system named HERCULES. This characterization technique not only helps a user to understand programs by searching pattern-of-interests, but also can be used for a predictive model that effectively selects the proper compiler optimizations. We formulated 35 loop patterns, then evaluated our characterization technique by comparing the predictive models constructed using HERCULES to three other state-of-the-art characterization methods. We show that our models outperform three state-of-the-art program characterization techniques on two multicore systems in selecting the best optimization combination from a given loop transformation space. We achieved up to 67% of the best possible speedup achievable with the optimization search space we evaluated. C1 [Park, Eunjung; Cavazos, John] Univ Delaware, Newark, DE 19716 USA. [Kartsaklis, Christos] Oak Ridge Natl Lab, Oak Ridge, TN USA. RP Park, E (reprint author), Univ Delaware, Newark, DE 19716 USA. EM epark@cis.udel.edu; kartsaklisc@ornl.gov; cavazos@cis.udel.edu FU U.S. Government [DE-AC0500OR22725]; Office of Science of the U.S. Department of Energy [DE-AC05-00OR22725]; U.S. National Science Foundation [0953667]; DARPA Computer Science Study Group (CSSG) FX The submitted manuscript has been authored by a contractor of the U.S. Government under Contract No. DE-AC0500OR22725. 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.; This research used resources of the Oak Ridge Leadership Computing Facility at the 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. This work was also funded in part by the U.S. National Science Foundation through Career award 0953667 and the DARPA Computer Science Study Group (CSSG). 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 0190-3918 BN 978-1-4799-5618-0 J9 PROC INT CONF PARAL PY 2014 BP 172 EP 181 DI 10.1109/ICPP.2014.26 PG 10 WC Computer Science, Theory & Methods SC Computer Science GA BG9LY UT WOS:000393410400018 ER PT S AU Sarje, A Li, XYS Hexemer, A AF Sarje, Abhinav Li, Xiaoye S. Hexemer, Alexander GP IEEE TI High-Performance Inverse Modeling with Reverse Monte Carlo Simulations SO 2014 43RD INTERNATIONAL CONFERENCE ON PARALLEL PROCESSING (ICPP) SE Proceedings of the International Conference on Parallel Processing LA English DT Proceedings Paper CT 43rd Annual International Conference on Parallel Processing (ICPP) CY SEP 09-12, 2014 CL Minneapolis, MN SP IEEE Comp Soc, Univ Minnesota, Int Assoc Comp & Commun ID MICROPOROUS CARBONS; IMPLEMENTATION AB In the field of nanoparticle material science, Xray scattering techniques are widely used for characterization of macromolecules and particle systems (ordered, partially-ordered or custom) based on their structural properties at the micro-and nano-scales. Numerous applications utilize these, including design and fabrication of energy-relevant nanodevices such as photovoltaic and energy storage devices. Due to its size, analysis of raw data obtained through present ultrafast light beamlines and X-ray scattering detectors has been a primary bottleneck in such characterization processes. To address this hurdle, we are developing high-performance parallel algorithms and codes for analysis of X-ray scattering data for several of the scattering methods, such as the Small Angle X-ray Scattering (SAXS), which we talk about in this paper. As an inverse modeling problem, structural fitting of the raw data obtained through SAXS experiments is a method used for extracting meaningful information on the structural properties of materials. Such fitting processes involve a large number of variable parameters and, hence, require a large amount of computational power. In this paper, we focus on this problem and present a high-performance and scalable parallel solution based on the Reverse Monte Carlo simulation algorithm, on highly-parallel systems such as clusters of multicore CPUs and graphics processors. We have implemented and optimized our algorithm on generic multi-core CPUs as well as the Nvidia GPU architectures with C++ and CUDA. We also present detailed performance results and computational analysis of our code. C1 [Sarje, Abhinav; Li, Xiaoye S.] Lawrence Berkeley Natl Lab, Computat Res Div, Berkeley, CA 94720 USA. [Hexemer, Alexander] Lawrence Berkeley Natl Lab, Adv Light Souce, Berkeley, CA 94720 USA. RP Sarje, A (reprint author), Lawrence Berkeley Natl Lab, Computat Res Div, Berkeley, CA 94720 USA. FU Office of Science of the U.S. Department of Energy [DE-AC02-05CH11231, DE-AC05-00OR22725]; Office of Science, of the U.S. Department of Energy [DE-AC02-05CH11231]; DOE Early Career Research Program grant FX We used resources of the National Energy Research Scientific Computing Center, which along with this work is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. We also used resources of the Oak Ridge Leadership Computing Facility at the 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. This work was supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. In addition, A. Hexemer was supported by a DOE Early Career Research Program grant. NR 19 TC 2 Z9 2 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0190-3918 BN 978-1-4799-5618-0 J9 PROC INT CONF PARAL PY 2014 BP 201 EP 210 DI 10.1109/ICPP.2014.29 PG 10 WC Computer Science, Theory & Methods SC Computer Science GA BG9LY UT WOS:000393410400021 ER PT S AU Rajbhandari, S Nikam, A Lai, PW Stock, K Krishnamoorthy, S Sadayappan, P AF Rajbhandari, Samyam Nikam, Akshay Lai, Pai-Wei Stock, Kevin Krishnamoorthy, Sriram Sadayappan, P. GP IEEE TI CAST: Contraction Algorithm for Symmetric Tensors SO 2014 43RD INTERNATIONAL CONFERENCE ON PARALLEL PROCESSING (ICPP) SE Proceedings of the International Conference on Parallel Processing LA English DT Proceedings Paper CT 43rd Annual International Conference on Parallel Processing (ICPP) CY SEP 09-12, 2014 CL Minneapolis, MN SP IEEE Comp Soc, Univ Minnesota, Int Assoc Comp & Commun ID COUPLED-CLUSTER THEORY; MATRIX MULTIPLICATION; QUANTUM-CHEMISTRY; COMMUNICATION AB Tensor contractions represent the most compute-intensive core kernels in ab initio computational quantum chemistry and nuclear physics. Symmetries in these tensor contractions make them difficult to load balance and scale to large distributed systems. In this paper, we develop an efficient and scalable algorithm to contract symmetric tensors. We introduce a novel approach that avoids data redistribution during contraction of symmetric tensors while also bypassing redundant storage and maintaining load balance. We present experimental results on two parallel supercomputers for several symmetric contractions that appear in the coupled cluster singles and doubles (CCSD) quantum chemistry method. We also present a novel approach to tensor redistribution that can take advantage of parallel hyperplanes when the initial distribution has replicated dimensions, and use collective broadcast when the final distribution has replicated dimensions, making the algorithm very efficient. C1 [Rajbhandari, Samyam; Nikam, Akshay; Lai, Pai-Wei; Stock, Kevin; Sadayappan, P.] Ohio State Univ, Dept Comp Sci & Engn, Columbus, OH 43210 USA. [Krishnamoorthy, Sriram] Pacific Northwest Natl Lab, Computat Sci & Math Div, Richland, WA 99352 USA. RP Rajbhandari, S (reprint author), Ohio State Univ, Dept Comp Sci & Engn, Columbus, OH 43210 USA. EM rajbhand@cse.ohio-state.edu; nikam@cse.ohio-state.edu; laip@cse.ohio-state.edu; stockk@cse.ohio-state.edu; sriram@pnnl.gov; saday@cse.ohio-state.edu FU U.S. Department of Energy's (DOE) Office of Science, Office of Advanced Scientific Computing Research [63823, DE-SC0008844] FX This work was supported in part by the U.S. Department of Energy's (DOE) Office of Science, Office of Advanced Scientific Computing Research, under awards 63823 and DE-SC0008844. 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 0190-3918 BN 978-1-4799-5618-0 J9 PROC INT CONF PARAL PY 2014 BP 261 EP 272 DI 10.1109/ICPP.2014.35 PG 12 WC Computer Science, Theory & Methods SC Computer Science GA BG9LY UT WOS:000393410400027 ER PT S AU Bailey, PE Lowenthal, DK Ravi, V Rountree, B Schulz, M de Supinski, BR AF Bailey, Peter E. Lowenthal, David K. Ravi, Vignesh Rountree, Barry Schulz, Martin de Supinski, Bronis R. GP IEEE TI Adaptive Configuration Selection for Power-Constrained Heterogeneous Systems SO 2014 43RD INTERNATIONAL CONFERENCE ON PARALLEL PROCESSING (ICPP) SE Proceedings of the International Conference on Parallel Processing LA English DT Proceedings Paper CT 43rd Annual International Conference on Parallel Processing (ICPP) CY SEP 09-12, 2014 CL Minneapolis, MN SP IEEE Comp Soc, Univ Minnesota, Int Assoc Comp & Commun ID PERFORMANCE; PROCESSORS; ADAPTATION; MODEL AB As power becomes an increasingly important design factor in high-end supercomputers, future systems will likely operate with power limitations significantly below their peak power specifications. These limitations will be enforced through a combination of software and hardware power policies, which will filter down from the system level to individual nodes. Hardware is already moving in this direction by providing power-capping interfaces to the user. The power/performance trade-off at the node level is critical in maximizing the performance of power-constrained cluster systems, but is also complex because of the many interacting architectural features and accelerators that comprise the hardware configuration of a node. The key to solving this challenge is an accurate power/performance model that will aid in selecting the right configuration from a large set of available configurations. In this paper, we present a novel approach to generate such a model offline using kernel clustering and multivariate linear regression. Our model requires only two iterations to select a configuration, which provides a significant advantage over exhaustive search-based strategies. We apply our model to predict power and performance for different applications using arbitrary configurations, and show that our model, when used with hardware frequency-limiting, selects configurations with significantly higher performance at a given power limit than those chosen by frequency-limiting alone. When applied to a set of 36 computational kernels from a range of applications, our model accurately predicts power and performance; it maintains 91% of optimal performance while meeting power constraints 88% of the time. When the model violates a power constraint, it exceeds the constraint by only 6% in the average case, while simultaneously achieving 54% more performance than an oracle. C1 [Bailey, Peter E.; Lowenthal, David K.] Univ Arizona, Dept Comp Sci, Tucson, AZ 85721 USA. [Ravi, Vignesh] Adv Micro Devices Inc, Sunnyvale, CA 94088 USA. [Rountree, Barry; Schulz, Martin; de Supinski, Bronis R.] Lawrence Livermore Natl Lab, Livermore, CA USA. RP Bailey, PE (reprint author), Univ Arizona, Dept Comp Sci, Tucson, AZ 85721 USA. EM pbailey@cs.arizona.edu; dkl@cs.arizona.edu; Vignesh.Ravi@amd.com; rountree4@llnl.gov; schulzm@llnl.gov; bronis@llnl.gov FU National Science Foundation Graduate Research Fellowship [1216829] FX This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. 1216829. This work was partially performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DEAC52-07NA27344. NR 43 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0190-3918 BN 978-1-4799-5618-0 J9 PROC INT CONF PARAL PY 2014 BP 371 EP 380 DI 10.1109/ICPP.2014.46 PG 10 WC Computer Science, Theory & Methods SC Computer Science GA BG9LY UT WOS:000393410400038 ER PT S AU Levy, S Ferreira, KB Bridges, PG AF Levy, Scott Ferreira, Kurt B. Bridges, Patrick G. GP IEEE TI Characterizing the Impact of Rollback Avoidance at Extreme-Scale: A Modeling Approach SO 2014 43RD INTERNATIONAL CONFERENCE ON PARALLEL PROCESSING (ICPP) SE Proceedings of the International Conference on Parallel Processing LA English DT Proceedings Paper CT 43rd Annual International Conference on Parallel Processing (ICPP) CY SEP 09-12, 2014 CL Minneapolis, MN SP IEEE Comp Soc, Univ Minnesota, Int Assoc Comp & Commun ID PREDICTION; SYSTEMS; HPC AB Resilience to failure is a key concern for next-generation high-performance computing systems. The dominant fault tolerance mechanism, coordinated checkpoint/restart, is projected to no longer be a viable option on these systems due to its predicted overheads. Rollback avoidance has the potential to prolong the viability of coordinated checkpoint/restart by allowing an application to make meaningful forward progress, perhaps with degraded performance, despite the occurrence or imminence of a failure. In this paper, we present two general analytic models for the performance of rollback avoidance techniques and validate these models against the performance of existing rollback avoidance techniques. We then use these models to evaluate the applicability of rollback avoidance for next-generation exascale systems. This includes analysis of exascale system design questions such as: (1) how effective must an application-specific rollback avoidance technique be to usefully augment checkpointing in an exascale system? (2) when is rollback avoidance on its own a viable alternative to coordinated checkpointing? and (3) how do rollback avoidance techniques and system characteristics interact to influence application performance? C1 [Levy, Scott; Bridges, Patrick G.] Univ New Mexico, Dept Comp Sci, Albuquerque, NM 87131 USA. [Ferreira, Kurt B.] Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RP Levy, S (reprint author), Univ New Mexico, Dept Comp Sci, Albuquerque, NM 87131 USA. EM slevy@cs.unm.edu; kbferre@sandia.gov; bridges@cs.unm.edu FU U.S. Department of Energy's National Nuclear Security Administration [DE-AC04-94AL85000] FX Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. NR 27 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0190-3918 BN 978-1-4799-5618-0 J9 PROC INT CONF PARAL PY 2014 BP 401 EP 410 DI 10.1109/ICPP.2014.49 PG 10 WC Computer Science, Theory & Methods SC Computer Science GA BG9LY UT WOS:000393410400041 ER PT S AU Dong, TX Haidar, A Tomov, S Dongarra, J AF Dong, Tingxing Haidar, Azzam Tomov, Stanimire Dongarra, Jack GP IEEE TI A Fast Batched Cholesky Factorization on a GPU SO 2014 43RD INTERNATIONAL CONFERENCE ON PARALLEL PROCESSING (ICPP) SE Proceedings of the International Conference on Parallel Processing LA English DT Proceedings Paper CT 43rd Annual International Conference on Parallel Processing (ICPP) CY SEP 09-12, 2014 CL Minneapolis, MN SP IEEE Comp Soc, Univ Minnesota, Int Assoc Comp & Commun AB Currently, state of the art libraries, like MAGMA, focus on very large linear algebra problems, while solving many small independent problems, which is usually referred to as batched problems, is not given adequate attention. In this paper, we proposed a batched Cholesky factorization on a GPU. Three algorithms - non-blocked, blocked, and recursive blocked - were examined. The left-looking version of the Cholesky factorization is used to factorize the panel, and the right-looking Cholesky version is used to update the trailing matrix in the recursive blocked algorithm. Our batched Cholesky achieves up to 1.8x speedup compared to the optimized parallel implementation in the MKL library on two sockets of Intel Sandy Bridge CPUs. Further, we use the new routines to develop a single Cholesky factorization solver which targets large matrix sizes. Our approach differs from MAGMA by having an entirely GPU implementation where both the panel factorization and the trailing matrix updates are on the GPU. Such an implementation does not depend on the speed of the CPU. Compared to the MAGMA library, our full GPU solution achieves 85% of the hybrid MAGMA performance which uses 16 Sandy Bridge cores, in addition to a K40 Nvidia GPU. Moreover, we achieve 80% of the practical dgemm peak of the machine, while MAGMA achieves only 75%, and finally, in terms of energy consumption, we outperform MAGMA by 1.5x in performance-per-watt for large matrices. C1 [Dong, Tingxing; Haidar, Azzam; Tomov, Stanimire; Dongarra, Jack] Univ Tennessee, Innovat Comp Lab, Knoxville, TN 37916 USA. [Dongarra, Jack] Oak Ridge Natl Lab, Oak Ridge, TN USA. [Dongarra, Jack] Univ Manchester, Manchester M13 9PL, Lancs, England. RP Dong, TX (reprint author), Univ Tennessee, Innovat Comp Lab, Knoxville, TN 37916 USA. EM tdong@utk.edu; haidar@utk.edu; tomov@utk.edu; dongarra@utk.edu FU National Science Foundation; Department of Energy; NVIDIA; MAGMA FX The authors would like to thank the National Science Foundation, the Department of Energy, NVIDIA and MAGMA project support. NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 0190-3918 BN 978-1-4799-5618-0 J9 PROC INT CONF PARAL PY 2014 BP 432 EP 440 DI 10.1109/ICPP.2014.52 PG 9 WC Computer Science, Theory & Methods SC Computer Science GA BG9LY UT WOS:000393410400044 ER PT S AU Garcia, HE Meerkov, SM Ravichandran, MT AF Garcia, Humberto E. Meerkov, Semyon M. Ravichandran, Maruthi T. GP IEEE TI Combating Curse of Dimensionality in Resilient Plant Monitoring Systems: Overlapping Decomposition and Knowledge Fusion SO 2014 52ND ANNUAL ALLERTON CONFERENCE ON COMMUNICATION, CONTROL, AND COMPUTING (ALLERTON) SE Annual Allerton Conference on Communication Control and Computing LA English DT Proceedings Paper CT 52nd Annual Allerton Conference on Communication, Control, and Computing Allerton CY OCT 01-03, 2014 CL Monticello, IL AB Resilient plant monitoring systems (RPMS) are sensor networks that degrade gracefully under cyber-physical attacks. In the previous work, we have developed an adaptive four-layer RPMS architecture and evaluated its performance under various attack scenarios. While the steady state performance of this system has been shown to be satisfactory, the transients have not: adaptation time grows exponentially as a function of the number of states in the network. The current paper is intended to provide a method for combating this curse of dimensionality. The approach is based on the idea of overlapping plant decomposition and subsequent fusion of knowledge derived in the overlapping subnetworks. In this paper such a monitoring system is developed (five-layer architecture), analyzed, and shown to have desirable steady state and, to a certain extent, transient characteristics. C1 [Garcia, Humberto E.] Idaho Natl Lab, POB 1625, Idaho Falls, ID 83415 USA. [Meerkov, Semyon M.; Ravichandran, Maruthi T.] Univ Michigan, Dept Elect Engn & Comp Sci, Ann Arbor, MI 48109 USA. RP Garcia, HE (reprint author), Idaho Natl Lab, POB 1625, Idaho Falls, ID 83415 USA. EM Humberto.Garcia@inl.gov; smm@umich.edu; marutrav@umich.edu NR 18 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2474-0195 BN 978-1-4799-8009-3 J9 ANN ALLERTON CONF PY 2014 BP 637 EP 642 PG 6 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF1QA UT WOS:000380426900087 ER PT S AU Boardman, B Harden, T Martinez, S AF Boardman, Beth Harden, Troy Martinez, Sonia GP IEEE TI Optimal Kinodynamic Motion Planning in Environments with Unexpected Obstacles SO 2014 52ND ANNUAL ALLERTON CONFERENCE ON COMMUNICATION, CONTROL, AND COMPUTING (ALLERTON) SE Annual Allerton Conference on Communication Control and Computing LA English DT Proceedings Paper CT 52nd Annual Allerton Conference on Communication, Control, and Computing Allerton CY OCT 01-03, 2014 CL Monticello, IL ID DYNAMIC ENVIRONMENTS; RRTS AB This paper presents and analyzes a new algorithm, the Goal Tree (GT) algorithm, for motion planning in dynamic environments where new, unexpected obstacles appear sporadically. The GT builds on the RRT* algorithm by employing an initial RRT* tree rooted at the goal. When finding new obstacle information, O, the GT quickly constructs a new tree rooted at the current location of the robot, x(I'), by sampling in a strict subset of the free space. The new tree then reuses branches from the original tree so that it can produce paths to the goal. Compared to running the RRT*, the GT reduces, on average, the time needed to produce a path of equal cost. We prove that, generically, there exists a region, which is a strict subset of the free space, which can be used with the GT algorithm to produce an asymptotically globally optimal path. This region is theoretically characterized for planning problems in d dimensional environments. An alternative region is provided for robots with Dubins' vehicle dynamics and a vehicle with no dynamics both under a Euclidean distance cost function. Simulations for a Dubins' vehicle robot verify our results. C1 [Boardman, Beth; Martinez, Sonia] Univ Calif San Diego, Mech & Aerosp Engn, 9500 Gilman Dr, La Jolla, CA 92093 USA. [Boardman, Beth; Harden, Troy] Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Boardman, B (reprint author), Univ Calif San Diego, Mech & Aerosp Engn, 9500 Gilman Dr, La Jolla, CA 92093 USA. EM bboardman@ucsd.edu; soniamd@ucsd.edu; harden@lanl.gov 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 SN 2474-0195 BN 978-1-4799-8009-3 J9 ANN ALLERTON CONF PY 2014 BP 1026 EP 1032 PG 7 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF1QA UT WOS:000380426900139 ER PT J AU Gerlach, W Tang, W Keegan, K Harrison, T Wilke, A Bischof, J D'Souza, M Devoid, S Murphy-Olson, D Desai, N Meyer, F AF Gerlach, Wolfgang Tang, Wei Keegan, Kevin Harrison, Travis Wilke, Andreas Bischof, Jared D'Souza, Mark Devoid, Scott Murphy-Olson, Daniel Desai, Narayan Meyer, Folker GP IEEE TI Skyport - Container-Based Execution Environment Management for Multi-Cloud Scientific Workflows SO 2014 5TH INTERNATIONAL WORKSHOP ON DATA-INTENSIVE COMPUTING IN THE CLOUDS (DATACLOUD) LA English DT Proceedings Paper CT DataCloud 5th International Workshop on Data Intensive Computing in the Clouds CY NOV 16-21, 2014 CL SC14 The International Conference for High Performance Computing,Networkin, New Orleans, LA SP acm, IEEE Comp Soc, sighpc HO SC14 The International Conference for High Performance Computing,Networkin ID COMMUNITY AB Recently, Linux container technology has been gaining attention as it promises to transform the way software is developed and deployed. The portability and ease of deployment makes Linux containers an ideal technology to be used in scientific workflow platforms. Skyport utilizes Docker Linux containers to solve software deployment problems and resource utilization inefficiencies inherent to all existing scientific workflow platforms. As an extension to AWE/Shock, our data analysis platform that provides scalable workflow execution environments for scientific data in the cloud, Sky port greatly reduces the complexity associated with providing the environment necessary to execute complex workflows. C1 [Gerlach, Wolfgang; Keegan, Kevin; Harrison, Travis; Bischof, Jared; D'Souza, Mark; Devoid, Scott; Murphy-Olson, Daniel; Meyer, Folker] Univ Chicago, Chicago, IL 60637 USA. [Gerlach, Wolfgang; Tang, Wei; Keegan, Kevin; Harrison, Travis; Wilke, Andreas; Bischof, Jared; D'Souza, Mark; Devoid, Scott; Murphy-Olson, Daniel; Meyer, Folker] Argonne Natl Lab, Argonne, IL USA. [Desai, Narayan] Ericsson, San Jose, CA USA. RP Gerlach, W (reprint author), Univ Chicago, Chicago, IL 60637 USA. EM wgerlach@mcs.anl.gov NR 26 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7034-6 PY 2014 BP 25 EP 32 DI 10.1109/DataCloud.2014.6 PG 8 WC Computer Science, Information Systems; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BF2LG UT WOS:000380477500005 ER PT J AU Elliott, J Hoemmen, M Mueller, F AF Elliott, James Hoemmen, Mark Mueller, Frank GP IEEE TI Exploiting Data Representation for Fault Tolerance SO 2014 5th Workshop on Latest Advances in Scalable Algorithms for Large-Scale Systems (ScalA) LA English DT Proceedings Paper CT 5th Workshop on Latest Advances in Scalable Algorithms for Large-Scale Systems (ScalA) CY NOV 17, 2014 CL New Orleans, LA SP ACM, IEEE Comp Soc, ACM SIGHPC, IEEE ID GMRES AB We explore the link between data representation and soft errors in dot products. We present an analytic model for the absolute error introduced should a soft error corrupt a bit in an IEEE-754 floating-point number. We show how this finding relates to the fundamental linear algebra concepts of normalization and matrix equilibration. We present a case study illustrating that the probability of experiencing a large error in a dot product is minimized when both vectors are normalized. Furthermore, when data is normalized we show that the absolute error is less than one or very large, which allows us to detect large errors. We demonstrate how this finding can be used by instrumenting the GMRES iterative solver. We count all possible errors that can be introduced through faults in arithmetic in the computationally intensive orthogonalization phase, and show that when scaling is used the absolute error can be bounded above by one. C1 [Elliott, James; Mueller, Frank] North Carolina State Univ, Dept Comp Sci, Raleigh, NC 27695 USA. [Elliott, James; Hoemmen, Mark] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Elliott, J (reprint author), North Carolina State Univ, Dept Comp Sci, Raleigh, NC 27695 USA. NR 20 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7562-4 PY 2014 BP 9 EP 16 DI 10.1109/ScalA.2014.5 PG 8 WC Computer Science, Theory & Methods SC Computer Science GA BG4XM UT WOS:000389245400002 ER PT J AU Cao, CX Gates, M Haidar, A Luszczek, P Tomov, S Yamazaki, I Dongarra, J AF Cao, Chongxiao Gates, Mark Haidar, Azzam Luszczek, Piotr Tomov, Stanimire Yamazaki, Ichitaro Dongarra, Jack GP IEEE TI Performance and Portability with OpenCL for Throughput-Oriented HPC Workloads Across Accelerators, Coprocessors, and Multicore Processors SO 2014 5th Workshop on Latest Advances in Scalable Algorithms for Large-Scale Systems (ScalA) LA English DT Proceedings Paper CT 5th Workshop on Latest Advances in Scalable Algorithms for Large-Scale Systems (ScalA) CY NOV 17, 2014 CL New Orleans, LA SP ACM, IEEE Comp Soc, ACM SIGHPC, IEEE ID SOFTWARE AB Ever since accelerators and coprocessors became the mainstream hardware for throughput-oriented HPC workloads, various programming techniques have been proposed to increase productivity in terms of both the performance and ease-of-use. We evaluate these aspects of OpenCL on a number of hardware platforms for an important subset of dense linear algebra operations that are relevant to a wide range of scientific applications. Our findings indicate that OpenCL portability has improved since our previous publication and many new and surprising usage scenarios are possible that rival those available after decades of software development on the CPUs. The combined performance-portability metric, even though not promised by the OpenCL standard, reflects the need for tuning performance-critical operations during the porting process and we show how a large portion of the available efficiency is lost if the tuning is not done correctly. C1 [Cao, Chongxiao; Gates, Mark; Haidar, Azzam; Luszczek, Piotr; Tomov, Stanimire; Yamazaki, Ichitaro] Univ Tennessee, Knoxville, TN 37996 USA. [Dongarra, Jack] Univ Tennessee, Oak Ridge Natl Lab, Knoxville, TN 37996 USA. [Dongarra, Jack] Univ Manchester, Manchester M13 9PL, Lancs, England. RP Cao, CX (reprint author), Univ Tennessee, Knoxville, TN 37996 USA. NR 29 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7562-4 PY 2014 BP 61 EP 68 DI 10.1109/ScalA.2014.8 PG 8 WC Computer Science, Theory & Methods SC Computer Science GA BG4XM UT WOS:000389245400009 ER PT J AU Dai, D Ross, RB Carns, P Kimpe, D Chen, Y AF Dai, Dong Ross, Robert B. Carns, Philip Kimpe, Dries Chen, Yong GP IEEE TI Using Property Graphs for Rich Metadata Management in HPC Systems SO 2014 9TH PARALLEL DATA STORAGE WORKSHOP (PDSW) LA English DT Proceedings Paper CT 9th Parallel Data Storage Workshop (PDSW) CY NOV 16-16, 2014 CL New Orleans, LA SP ACM, IEEE Comp Soc, Sighpc ID PROVENANCE; SCIENCE AB HPC platforms are capable of generating huge amounts of metadata about different entities including jobs, users, and files. Simple metadata, which describe the attributes of these entities (e.g., file size, name, and permissions mode), has been well recorded and used in current systems. However, only a limited amount of rich metadata, which records not only the attributes of entities but also relationships between them, are captured in current HPC systems. Rich metadata may include information from many sources, including users and applications, and must be integrated into a unified framework. Collecting, integrating, processing, and querying such a large volume of metadata pose considerable challenges for HPC systems. In this paper, we propose a rich metadata management approach that unifies metadata into one generic property graph. We argue that this approach supports not only simple metadata operations such as directory traversal and permission validation but also rich metadata operations such as provenance query and security auditing. The property graph approach provides an extensible method to store diverse metadata and presents an opportunity to leverage rapidly evolving graph storage and processing techniques. C1 [Dai, Dong; Chen, Yong] Texas Tech Univ, Comp Sci Dept, Lubbock, TX 79409 USA. [Ross, Robert B.; Carns, Philip; Kimpe, Dries] Argonne Natl Lab, Math & Comp Sci Div, Argonne, IL 60439 USA. RP Dai, D (reprint author), Texas Tech Univ, Comp Sci Dept, Lubbock, TX 79409 USA. EM dong.dai@ttu.edu; rross@mcs.anl.gov; pcarns@mcs.anl.gov; dkimpe@mcs.anl.gov; yong.chen@ttu.edu NR 32 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7025-4 PY 2014 BP 7 EP 12 DI 10.1109/PDSW.2014.11 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BF3DK UT WOS:000380529700002 ER PT J AU Behzad, B Dang, HV Hariri, F Zhang, WZ Snir, M AF Behzad, Babak Hoang-Vu Dang Hariri, Farah Zhang, Weizhe Snir, Marc GP IEEE TI Automatic Generation of I/O Kernels for HPC Applications SO 2014 9TH PARALLEL DATA STORAGE WORKSHOP (PDSW) LA English DT Proceedings Paper CT 9th Parallel Data Storage Workshop (PDSW) CY NOV 16-16, 2014 CL New Orleans, LA SP ACM, IEEE Comp Soc, Sighpc DE Parallel I/O; I/O trace and replay; I/O kernels AB The study of the I/O performance of a parallel application can be facilitated by the use of an I/O kernel - a program that generates the same I/O calls as the original application, but can be executed much faster. Such I/O kernels are especially important when the programs under study are proprietary or classified, and only available in binary form. In this paper, we show how to create automatically such an I/O kernel, by executing the target application with an instrumented I/O library, next "compressing" the resulting I/O traces into a compact C program that generates those traces. C1 [Behzad, Babak; Hoang-Vu Dang; Hariri, Farah; Snir, Marc] Univ Illinois, Urbana, IL 61801 USA. [Zhang, Weizhe] Harbin Inst Technol, Harbin, Peoples R China. [Snir, Marc] Argonne Natl Lab, Argonne, IL 60439 USA. RP Behzad, B (reprint author), Univ Illinois, Urbana, IL 61801 USA. 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 BN 978-1-4799-7025-4 PY 2014 BP 31 EP 36 DI 10.1109/PDSW.2014.6 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BF3DK UT WOS:000380529700006 ER PT J AU Carey, V Abbasi, H Rodero, I Kolla, H AF Carey, Varis Abbasi, Hasan Rodero, Ivan Kolla, Hemanth GP IEEE TI Sensitivity Analysis for Time Dependent Problems: Optimal Checkpoint-Recompute HPC Workflows SO 2014 9th Workshop on Workflows in Support of Large-Scale Science (WORKS) LA English DT Proceedings Paper CT 9th Workshop on Workflows in Support of Large-Scale Science (WORKS) CY NOV 16, 2014 CL New Orleans, LA SP ACM, IEEE Comp Soc, Sighpc ID MEMORY AB Sensitivity analysis (SA) is a fundamental tool of uncertainty quantification(UQ). Adjoint-based SA is the optimal approach in many large-scale applications, such as the direct numerical simulation (DNS) of combustion. However, one of the challenges of the adjoint workflow for time-dependent applications is the storage and I/O requirements for the application state. During the time-reversal portion of the workflow, forward state is required in last-in-first-out order. The resulting requirements for storage at exascale are enormous. To mitigate this requirement, application state is regenerated from checkpoints over short windows of application time. This approach drastically reduces the total volume of stored data, allows the caching of state in the regeneration window in memory and on local SSDs, may accelerate the application execution by reducing output frequency, and reduces the power overhead from I/O. We explore variations to this workflow, applied to a proxy for the SA of turbulent combustion, by varying checkpoint number, state storage, and other regeneration options to find efficient implementations for minimizing compute time or power consumption. C1 [Carey, Varis] Univ Texas Austin, Inst Computat Engn & Sci, Austin, TX 78712 USA. [Abbasi, Hasan] Oak Ridge Natl Lab, Comp Sci & Math Div, Oak Ridge, TN USA. [Rodero, Ivan] Rutgers State Univ, Rutgers Discovery Informat Inst, New Brunswick, NJ USA. [Rodero, Ivan] Rutgers State Univ, NSF Cloud & Auton Comp Ctr, New Brunswick, NJ USA. [Kolla, Hemanth] Sandia Natl Labs, Scalable Modeling & Anal, Livermore, CA 94550 USA. RP Carey, V (reprint author), Univ Texas Austin, Inst Computat Engn & Sci, Austin, TX 78712 USA. EM varis@ices.utexas.edu; habbasi@ornl.gov; irodero@rutgers.edu; hnkolla@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 978-1-4799-7067-4 PY 2014 BP 20 EP 30 DI 10.1109/WORKS.2014.15 PG 11 WC Computer Science, Theory & Methods SC Computer Science GA BG4ZL UT WOS:000389276900003 ER PT J AU Deslippe, J Essiari, A Patton, SJ Samak, T Tull, CE Hexemer, A Kumar, D Parkinson, D Stewart, P AF Deslippe, Jack Essiari, Abdelilah Patton, Simon J. Samak, Taghrid Tull, Craig E. Hexemer, Alexander Kumar, Dinesh Parkinson, Dilworth Stewart, Polite GP IEEE TI Workflow Management for Real-time Analysis of Lightsource Experiments SO 2014 9th Workshop on Workflows in Support of Large-Scale Science (WORKS) LA English DT Proceedings Paper CT 9th Workshop on Workflows in Support of Large-Scale Science (WORKS) CY NOV 16, 2014 CL New Orleans, LA SP ACM, IEEE Comp Soc, Sighpc AB The Advanced lightsource (ALS) is a X-ray synchrotron facility at Lawrence Berkeley National Laboratory. The ALS generates terabytes of raw and derived data each day and serves 1,000's of researchers each year. Only a subset of the data is analyzed due to barriers in terms of processing that small science teams are ill-equipped to surmount. In this paper, we discuss the development and application of a computational framework, termed SPOT, fed with synchrotron data, powered by storage, networking and compute resources at NERSC and ESnet. We describe issues and recommendations for an end-toend analysis workflow for ALS data. After one year of operation, the collection contains over 90,000 datasets (550 TB) from 85 users across three beamlines. For 16 months, beamline data taken has been promptly and automatically analyzed and annotated with metadata, allowing users to focus on analysis, conclusions and experiments. C1 [Deslippe, Jack; Essiari, Abdelilah; Patton, Simon J.; Samak, Taghrid; Tull, Craig E.; Hexemer, Alexander; Kumar, Dinesh; Parkinson, Dilworth; Stewart, Polite] Lawrence Berkeley Natl Lab, Berkeley, CA USA. RP Deslippe, J (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA USA. EM jrdeslippe@lbl.gov NR 9 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7067-4 PY 2014 BP 31 EP 40 DI 10.1109/WORKS.2014.9 PG 10 WC Computer Science, Theory & Methods SC Computer Science GA BG4ZL UT WOS:000389276900004 ER PT J AU Balderrama, JR Simonin, M Ramakrishnan, L Hendrix, V Morin, C Agarwal, D Tedeschi, C AF Balderrama, Javier Rojas Simonin, Matthieu Ramakrishnan, Lavanya Hendrix, Valerie Morin, Christine Agarwal, Deborah Tedeschi, Cedric GP IEEE TI Combining Workflow Templates with a Shared Space-based Execution Model SO 2014 9th Workshop on Workflows in Support of Large-Scale Science (WORKS) LA English DT Proceedings Paper CT 9th Workshop on Workflows in Support of Large-Scale Science (WORKS) CY NOV 16, 2014 CL New Orleans, LA SP ACM, IEEE Comp Soc, Sighpc ID INTEROPERABILITY; SERVICES; WEB AB The growth for scientific data has led to data analysis being a critical step in the scientific process. The next-generation scientific data analysis environment needs to address two challenges i) productivity of the end-user and ii) scalability of the workflows. The need to ensure both goals requires us to revisit the design and implementation of workflow tools. In this paper, we study the interaction of Tigres and HOCL-TS towards meeting these goals. Tigres and HOCL-TS have evolved separately; however their complementary foci allows us to study these issues in greater detail. We describe the pros and cons of an approach that integrates Tigres and HOCL-TS and HOCL-TS extension to support common non-functional requirements such as logging and monitoring that can be made available to the users through the Tigres API. C1 [Balderrama, Javier Rojas; Simonin, Matthieu; Morin, Christine; Tedeschi, Cedric] INRIA, Rennes, France. [Ramakrishnan, Lavanya; Hendrix, Valerie; Agarwal, Deborah] Lawrence Berkeley Natl Lab, Berkeley, CA USA. [Tedeschi, Cedric] Univ Rennes 1, Rennes, France. RP Balderrama, JR (reprint author), INRIA, Rennes, France. NR 37 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7067-4 PY 2014 BP 50 EP 58 DI 10.1109/WORKS.2014.14 PG 9 WC Computer Science, Theory & Methods SC Computer Science GA BG4ZL UT WOS:000389276900006 ER PT S AU Nadelson, L Seifert, AL McKinney, M AF Nadelson, Louis Seifert, Anne Louise McKinney, Meagan GP ASEE TI Place Based STEM: Leveraging Local Resources to Engage K-12 Teachers in Teaching Integrated STEM and for Addressing the Local STEM Pipeline SO 2014 ASEE ANNUAL CONFERENCE SE ASEE Annual Conference & Exposition LA English DT Proceedings Paper CT ASEE Annual Conference CY JUN 15-18, 2014 CL Indianapolis, IN SP ASEE ID SCIENCE; CONFIDENCE; KNOWLEDGE AB Business, industry, parks, nature settings, government infrastructure, and people, can be invaluable resources for connecting STEM curriculum within context which results in conditions ideal for promoting purposeful learning of authentic STEM content. Thus, community-based STEM resources offer ideal context for teaching STEM content. A benefit of focusing teacher attention on these contextual, content aligned resources is that they are in every community; making place-based STEM education a possibility, regardless of the location of STEM teaching and learning. Further, associating STEM teaching and learning with local resources addresses workforce development and the STEM pipeline by exposing students to STEM careers and applications in their local communities. C1 [Nadelson, Louis; McKinney, Meagan] Boise State Univ, Coll Educ, Boise, ID 83725 USA. [Seifert, Anne Louise] Idaho Natl Lab, Idaho Falls, ID USA. RP Nadelson, L (reprint author), Boise State Univ, Coll Educ, Boise, ID 83725 USA. NR 21 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC ENGINEERING EDUCATION PI WASHINGTON PA 1818 N STREET, NW SUITE 600, WASHINGTON, DC 20036 USA SN 2153-5965 J9 ASEE ANNU CONF EXPO PY 2014 PG 21 WC Education & Educational Research; Education, Scientific Disciplines; Engineering, Multidisciplinary SC Education & Educational Research; Engineering GA BF6XU UT WOS:000383779803001 ER PT J AU Hsu, P Muljadi, E AF Hsu, Ping Muljadi, Eduard BE AbuSiada, A Masoum, MAS TI Damping Control for Permanent Magnet Synchronous Generators and Its Application in a Multi-turbine System SO 2014 Australasian Universities Power Engineering Conference (AUPEC) SE Australasian Universities Power Engineering Conference LA English DT Proceedings Paper CT Australasian Universities Power Engineering Conference (AUPEC) CY SEP 28-OCT 01, 2014 CL Perth, AUSTRALIA SP IEEE, ACPE, Curtin Univ, Australian Power Inst, ABB, Murdoch Univ, Univ Western Australia, Edith Cowan Univ, IEEE Power Elect Soc, IET, IEEE Power & Energy Soc, MagellanPower, Western Power, Engineers Australia DE Wind power; wind turbine; permanent magnet synchronous generator; damping control; maximum power tracking AB Permanent Magnet Synchronous Generator (PMSG) offers higher efficiency than induction and wound-field generators. This higher efficiency, however, manifests itself as a lack of natural damping. When connected to an AC voltage source, a small, sustained sub-synchronous oscillation is often observed. In this paper, we present a method for damping such undesirable oscillation without the need for a full power inverter, as required for implementing a field-oriented control algorithm. The power rating of proposed damping controller is only a small fraction of the power of the PMSG. The proposed damping controller can be used for grid-tied applications or in conjunction with a variable frequency converter, for variable speed operations. We demonstrate the application of the proposed damping controller in a wind turbine system that consists of multiple turbines using PMSGs and one shared converter. We also propose a method for peak power tracking for this multiple wind turbine configuration. C1 [Hsu, Ping] San Jose State Univ, Dept Elect Engn, San Jose, CA 95192 USA. [Muljadi, Eduard] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Hsu, P (reprint author), San Jose State Univ, Dept Elect Engn, San Jose, CA 95192 USA. FU U.S. Department of Energy [DE-AC36-08-GO28308]; National Renewable Energy Laboratory FX This work was supported by the U.S. Department of Energy under Contract No. DE-AC36-08-GO28308 with the National Renewable Energy Laboratory. NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-0-646-92375-8 J9 AUSTR UNIV POWER ENG PY 2014 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BG8WT UT WOS:000392752500101 ER PT S AU Randles, A Draeger, E Michor, F AF Randles, Amanda Draeger, Erik Michor, Franziska BE Murray, A TI Analysis of Pressure Gradient Across Aortic Stenosis with Massively Parallel Computational Simulations SO 2014 COMPUTING IN CARDIOLOGY CONFERENCE (CINC), VOL 41 SE Computing in Cardiology Conference LA English DT Proceedings Paper CT 41st Computing in Cardiology Conference (CinC) CY SEP 07-10, 2014 CL Cambridge, MA SP Massachusetts Inst Technol, European Soc Cardiol, IEEE EMBS, Mortara, PhysioNet, Philips, Mindray, IBM, Zoll, Mitsubishi Elect, lOP Publishing, IMES, CSAIL, Medtronic, Boston Sci, Samsung, GE AB Coarctation of the aorta (CoA) is one of the most common congenital heart defects in the United States, and despite treatment, patients have a decrease in life expectancy. Computational fluid dynamics simulations can provide the physician with a non-invasive method to measure the pressure gradient. With HARVEY, a massively parallel hemodynamics application, patient specific simulations can be conducted of large regions of the vasculature. The pressure across the stenosis is impacted by flow from nearby vessels. The purpose of this study was to study the impact of including these distal vessels in the simulation on the resulting pressure measurements. Computational fluid dynamic simulations were conducted in three subsets of one patient's vasculature. We demonstrate up to a 29% difference in calculated pressure gradient based on the number of vessels included in the simulation. These initial results are positive but need to be substantiated with further patient studies. C1 [Randles, Amanda; Draeger, Erik] Lawrence Livermore Natl Lab, Livermore, CA USA. [Randles, Amanda; Michor, Franziska] Dana Farber Canc Inst, Boston, MA 02115 USA. RP Randles, A (reprint author), 7000 East Ave, Livermore, CA 94550 USA. EM randles2@llnl.gov NR 14 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2325-887X BN 978-1-4799-4346-3 J9 COMPUT CARDIOL CONF PY 2014 VL 41 BP 217 EP 220 PG 4 WC Cardiac & Cardiovascular Systems; Computer Science, Interdisciplinary Applications; Mathematical & Computational Biology SC Cardiovascular System & Cardiology; Computer Science; Mathematical & Computational Biology GA BE2TW UT WOS:000370068300056 ER PT S AU Aguinaldo, R Forencich, A DeRose, C Lentine, A Trotter, DC Starbuck, A Fainman, Y Porter, G Papen, G Mookherjea, S AF Aguinaldo, Ryan Forencich, Alex DeRose, Christopher Lentine, Anthony Trotter, Douglas C. Starbuck, Andrew Fainman, Yeshaiahu Porter, George Papen, George Mookherjea, Shayan GP IEEE TI Energy-efficient, digitally-driven "fat pipe" silicon photonic circuit switch in the UCSD MORDIA data-center network SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB Using a compact (0.03 mm(boolean AND)2) silicon photonic thermo-optic switch with five cascaded thermotopic phase-shifters, we demonstrate low insertion loss, low power, microsecond-scale cross-bar switching of twenty wavelength channels, each carrying 10 Gbit/second data concurrently. C1 [Aguinaldo, Ryan; Forencich, Alex; Fainman, Yeshaiahu; Porter, George; Papen, George; Mookherjea, Shayan] Univ Calif San Diego, Mail Code 0407, La Jolla, CA 92093 USA. [DeRose, Christopher; Lentine, Anthony; Trotter, Douglas C.; Starbuck, Andrew] Sandia Natl Labs, Appl Microphoton Syst, Albuquerque, NM 87185 USA. RP Mookherjea, S (reprint author), Univ Calif San Diego, Mail Code 0407, La Jolla, CA 92093 USA. EM smookherjea@ucsd.edu NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908603116 ER PT S AU Aguinaldo, R Weigel, P Grant, H DeRose, C Lentine, A Pomerene, A Starbuck, A Tkacenko, A Mookherjea, S AF Aguinaldo, Ryan Weigel, Peter Grant, Hannah DeRose, Christopher Lentine, Anthony Pomerene, Andrew Starbuck, Andrew Tkacenko, Andre Mookherjea, Shayan GP IEEE TI A silicon photonic channelized spectrum monitor for UCSD's multi-wavelength ring network SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB A compact silicon photonic channelized optical spectrum monitor is designed and realized, which can replace a large rack-mounted OSA's channel power monitoring functionality, and the signal processing algorithm underlying its operation is described. C1 [Aguinaldo, Ryan; Weigel, Peter; Grant, Hannah; Mookherjea, Shayan] Univ Calif San Diego, Mail Code 0407, La Jolla, CA 92093 USA. [DeRose, Christopher; Lentine, Anthony; Pomerene, Andrew; Starbuck, Andrew] Sandia Natl Labs, Appl Microphoton Syst, Albuquerque, NM 87185 USA. [Tkacenko, Andre] NASA, Jet Prop Lab, Signal Proc Res Grp 332C, Pasadena, CA 91109 USA. RP Aguinaldo, R (reprint author), Univ Calif San Diego, Mail Code 0407, La Jolla, CA 92093 USA. EM raguinaldo@ucsd.edu; smookherjea@ucsd.edu NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908603097 ER PT S AU Albert, F Pollock, BB Shaw, JL Marsh, KA Raph, JE Chen, YH Alessi, D Pak, A Clayton, CE Glenzer, SH Joshi, C AF Albert, F. Pollock, B. B. Shaw, J. L. Marsh, K. A. Raph, J. E. Chen, Y. -H. Alessi, D. Pak, A. Clayton, C. E. Glenzer, S. H. Joshi, C. GP IEEE TI Angular dependance of betatron x-ray spectra in a laser-wakefield accelerator SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB Our experiments produced betatron x-rays up to 80 keV from a laser-wakefield accelerator. Measurements, performed with stacked image plates spectrometers, provide simultaneous information on the beam profile and spectrum at various angles of observation. (c) 2013 Optical Society of America C1 [Albert, F.; Pollock, B. B.; Raph, J. E.; Chen, Y. -H.; Alessi, D.; Pak, A.] Lawrence Livermore Natl Lab, NIF & Photon Sci, 7000 East Ave, Livermore, CA 94550 USA. [Shaw, J. L.; Marsh, K. A.; Clayton, C. E.; Joshi, C.] Univ Calif Los Angeles, Dept Elect Engn, Los Angeles, CA 90095 USA. [Glenzer, S. H.] SLAC Natl Accelerator Lab, Stanford, CA 94309 USA. RP Albert, F (reprint author), Lawrence Livermore Natl Lab, NIF & Photon Sci, 7000 East Ave, Livermore, CA 94550 USA. EM albert6@llnl.gov NR 4 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908601249 ER PT S AU Alessi, D Carr, CW Hackel, RP Stanion, K Cross, DA Fischer, M Nissen, JD Luthi, R Betts, S Gourdin, WH Britten, JA Fair, J Haefner, CL AF Alessi, D. Carr, C. W. Hackel, R. P. Stanion, K. Cross, D. A. Fischer, M. Nissen, J. D. Luthi, R. Betts, S. Gourdin, W. H. Britten, J. A. Fair, J. Haefner, C. L. GP IEEE TI Optical Damage Performance Assessment of Petawatt Final Optics for the Advanced Radiographic Capability SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID THRESHOLD AB To predict in-vacuum optical damage performance of Advanced Radiographic Capability Petawatt final optics we have developed a ps-damage test station to measure damage density and compare results to R-on-1 tests. C1 [Alessi, D.; Carr, C. W.; Hackel, R. P.; Stanion, K.; Cross, D. A.; Fischer, M.; Nissen, J. D.; Luthi, R.; Betts, S.; Gourdin, W. H.; Britten, J. A.; Fair, J.; Haefner, C. L.] Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA. RP Alessi, D (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA. EM alessi2@llnl.gov NR 10 TC 0 Z9 0 U1 1 U2 4 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908601243 ER PT S AU Bayn, I Chen, EH Li, LZ Trusheim, ME Schroder, T Gaathon, O Lu, M Stein, A Liu, MZ Kisslinger, K Englund, D AF Bayn, Igal Chen, Edward H. Li, Luozhou Trusheim, Matthew E. Schroeder, Tim Gaathon, Ophir Lu, Ming Stein, Aaron Liu, Mingzhao Kisslinger, Kim Englund, Dirk GP IEEE TI Implantation of proximal NV clusters in diamond by lithographically defined silicon masks with 5 nm resolution SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID SPINS AB We present the fabrication of nitrogen/vacancy (NV) spin chains by implantation through a silicon mask on diamond. A minimum implantation aperture width of 5 nm is produced. Super-resolution measurements reveal NV lines 26 nm wide and minimal NV-pitch of 8 nm. C1 [Bayn, Igal; Chen, Edward H.; Li, Luozhou; Schroeder, Tim; Gaathon, Ophir; Englund, Dirk] MIT, Dept Elect Engn & Comp Sci, 77 Massachusetts Ave,Bldg 36, Cambridge, MA 02139 USA. [Bayn, Igal; Chen, Edward H.; Li, Luozhou; Schroeder, Tim; Gaathon, Ophir; Englund, Dirk] MIT, Elect Res Lab, Cambridge, MA 02139 USA. [Bayn, Igal; Li, Luozhou; Gaathon, Ophir] Columbia Univ, Dept Elect Engn, New York, NY 10027 USA. [Trusheim, Matthew E.] Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10027 USA. [Lu, Ming; Stein, Aaron; Liu, Mingzhao; Kisslinger, Kim] Brookhaven Natl Lab, Ctr Funct Nanomat, Upton, NY 11973 USA. RP Bayn, I (reprint author), MIT, Dept Elect Engn & Comp Sci, 77 Massachusetts Ave,Bldg 36, Cambridge, MA 02139 USA. EM ibayn@mit.edu RI Kisslinger, Kim/F-4485-2014 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 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908601088 ER PT S AU Bayn, I Mouradian, S Li, LZ Schroder, T Gaathon, O Lu, M Stein, A Englund, D AF Bayn, Igal Mouradian, Sara Li, Luozhou Schroeder, Tim Gaathon, Ophir Lu, Ming Stein, Aaron Englund, Dirk GP IEEE TI Triangular nanobeam fabrication strategy for quantum photonic network realization in bulk diamond SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID CENTERS AB A triangular nanobeam architecture for a bulk-diamond quantum photonic networks based on silicon masking and angular etching is proposed and implemented. Cavities with Q>3x10(3) are demonstrated. S-bent interconnects for realizing a mm-scale network are introduced. C1 [Bayn, Igal; Mouradian, Sara; Li, Luozhou; Schroeder, Tim; Gaathon, Ophir; Englund, Dirk] MIT, Dept Elect Engn & Comp Sci, 77 Massachusetts Ave,Bldg 36, Cambridge, MA 02139 USA. [Bayn, Igal; Mouradian, Sara; Li, Luozhou; Schroeder, Tim; Gaathon, Ophir; Englund, Dirk] MIT, Elect Res Lab, Cambridge, MA 02139 USA. [Bayn, Igal; Li, Luozhou] Columbia Univ, Dept Elect Engn, New York, NY 10027 USA. [Lu, Ming; Stein, Aaron] Brookhaven Natl Lab, Ctr Funct Nahomat, Upton, NY 11973 USA. RP Bayn, I (reprint author), MIT, Dept Elect Engn & Comp Sci, 77 Massachusetts Ave,Bldg 36, Cambridge, MA 02139 USA.; Bayn, I (reprint author), MIT, Elect Res Lab, Cambridge, MA 02139 USA. EM ibayn@mit.edu 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 SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600172 ER PT S AU Benz, A Campione, S Liu, S Montano, I Klem, JF Sinclair, MB Capolino, F Brener, I AF Benz, A. Campione, S. Liu, S. Montano, I. Klem, J. F. Sinclair, M. B. Capolino, F. Brener, I. GP IEEE TI Strong Light-Matter Coupling in Mid-Infrared Monolithic Metamaterial Nanocavities SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We present the design and realization of strong light-matter coupling in monolithic metamaterial nanocavities. We achieve a Rabi frequency of 2.5 THz (corresponding to a polariton splitting of 20%) in a mode volume of 1.34x10(-3)(lambda/n)(3). C1 [Benz, A.; Campione, S.; Liu, S.; Brener, I.] Sandia Natl Labs, Ctr Integrated Nanotechnol CINT, POB 5800, Albuquerque, NM 87185 USA. [Benz, A.; Campione, S.; Liu, S.; Montano, I.; Klem, J. F.; Sinclair, M. B.; Brener, I.] Sandia Natl Labs, Albuquerque, NM 87185 USA. [Capolino, F.] Univ Calif Irvine, Dept Elect Engn & Comp Sci, Irvine, CA 92697 USA. RP Benz, A (reprint author), Sandia Natl Labs, Ctr Integrated Nanotechnol CINT, POB 5800, Albuquerque, NM 87185 USA. EM anbenz@sandia.gov 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 SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908601029 ER PT S AU Benz, A Montano, I Klem, JF Brener, I AF Benz, Alexander Montano, Ines Klem, John F. Brener, Igal GP IEEE TI Electrically Tunable Mid-Infrared Metamaterials Based on Strong Light-Matter Coupling SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We present an actively tunable mid-infrared metamaterial operating in the strong light-matter coupling regime. We can tune the upper polariton branch continuously over 8% of the center frequency by applying 5 V. C1 [Benz, Alexander; Brener, Igal] Sandia Natl Labs, Ctr Integrated Nanotechnol CINT, POB 5800, Albuquerque, NM 87185 USA. [Benz, Alexander; Montano, Ines; Klem, John F.; Brener, Igal] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Benz, A (reprint author), Sandia Natl Labs, Ctr Integrated Nanotechnol CINT, POB 5800, Albuquerque, NM 87185 USA. EM anbenz@sandia.gov NR 3 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600475 ER PT S AU Bohlin, A Kliewer, CJ AF Bohlin, Alexis Kliewer, Christopher J. GP IEEE TI Single-shot Coherent Raman Multiplex Planar Imaging SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We develop a coherent Raman technique for simultaneous planar imaging and multiplex spectroscopy provided in a single-laser-shot. Spatially correlated spectra from multiple species in a two-dimensional field are presented and possible gas-phase applications are discussed. C1 [Bohlin, Alexis; Kliewer, Christopher J.] Sandia Natl Labs, Combust Res Facil, Livermore, CA 94550 USA. RP Bohlin, A (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94550 USA. EM abohlin@sandia.gov; cjkliew@sandia.gov RI Bohlin, Alexis/L-8973-2015 OI Bohlin, Alexis/0000-0003-4383-8332 NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908603245 ER PT S AU Boley, CD Khairallah, SA Rubenchik, AM AF Boley, C. D. Khairallah, S. A. Rubenchik, A. M. GP IEEE TI Modeling of Powder Absorption in Additive Manufacturing SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We have investigated optical absorption by a powder of metal spheres, via ray-trace calculations. The absorptivity significantly exceeds that for normal incidence, because of multiple scattering. The effect of beam size is also discussed. C1 [Boley, C. D.; Khairallah, S. A.; Rubenchik, A. M.] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Boley, CD (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM boley1@llnl.gov; khairallah1@llnl.gov; rubenchik1@llnl.gov NR 2 TC 0 Z9 0 U1 2 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600033 ER PT S AU Boyson, TK Rittman, DR Spence, TG Kirkbride, KP Moore, DS Harb, CC AF Boyson, Toby K. Rittman, Dylan R. Spence, Thomas G. Kirkbride, K. Paul Moore, David S. Harb, Charles C. GP IEEE TI Rapid, wideband cavity ringdown spectroscopy for the detection of explosives SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We present results from a variant of CRDS that allows large spectral bandwidths to be analysed in real time. We have applied the technique to the analysis and detection of explosives and related compounds. (C) 2014 Optical Society of America C1 [Boyson, Toby K.; Harb, Charles C.] Univ New S Wales, Univ Coll, Sch Engn & Informat Technol, Canberra, ACT 2600, Australia. [Rittman, Dylan R.; Moore, David S.] Los Alamos Natl Lab, Shock & Detonat Phys Grp, Los Alamos, NM 87545 USA. [Spence, Thomas G.] Loyola Univ, Dept Math Sci, New Orleans, LA 70118 USA. [Spence, Thomas G.] Loyola Univ, Dept Chem, New Orleans, LA 70118 USA. [Kirkbride, K. Paul] Flinders Univ S Australia, Sch Chem & Phys Sci, Adelaide, SA 5001, Australia. RP Boyson, TK (reprint author), Univ New S Wales, Univ Coll, Sch Engn & Informat Technol, Canberra, ACT 2600, Australia. EM t.boyson@adfa.edu.au 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 SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600126 ER PT S AU Burghoff, D Kao, TY Han, NR Chan, CWI Hayton, DJ Gao, JR Reno, JL Hu, Q AF Burghoff, David Kao, Tsung-Yu Han, Ningren Chan, Chun Wang Ivan Hayton, Darren J. Gao, Jian-Rong Reno, John L. Hu, Qing GP IEEE TI Development of terahertz laser frequency combs SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We demonstrate broadband terahertz laser frequency combs, compact semiconductor devices that combine the high power of lasers with the broad spectra of pulsed sources. C1 [Burghoff, David; Kao, Tsung-Yu; Han, Ningren; Chan, Chun Wang Ivan; Hu, Qing] MIT, Elect Res Lab, Dept Elect Engn & Comp Sci, 77 Massachusetts Ave, Cambridge, MA 02139 USA. [Hayton, Darren J.; Gao, Jian-Rong] SRON Netherlands Inst Space Res, NL-9747 AD Groningen, Netherlands. [Gao, Jian-Rong] Delft Univ Technol, Kavli Inst NanoSci, NL-2628 CJ Delft, Netherlands. [Reno, John L.] Sandia Natl Labs, Ctr Integrated Nanotechnol, Albuquerque, NM 87123 USA. RP Burghoff, D (reprint author), MIT, Elect Res Lab, Dept Elect Engn & Comp Sci, 77 Massachusetts Ave, Cambridge, MA 02139 USA. EM burghoff@mit.edu 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 SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908603034 ER PT S AU Campione, S Benz, A Klem, JF Sinclair, MB Brener, I Capolino, F AF Campione, Salvatore Benz, Alexander Klem, John F. Sinclair, Michael B. Brener, Igal Capolino, Filippo GP IEEE TI Maximizing Strong Coupling between Metasurface Resonators and Intersubband Transitions SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We analyze strongly coupled systems that use metasurface resonators and provide an electrodynamic model based on the quasi-static electric near fields that can be used to predict and maximize Rabi splitting varying resonator geometry. C1 [Campione, Salvatore; Benz, Alexander; Brener, Igal] Sandia Natl Labs, Ctr Integrated Nanotechnol, POB 5800, Albuquerque, NM 87185 USA. [Campione, Salvatore; Benz, Alexander; Klem, John F.; Sinclair, Michael B.; Brener, Igal] Sandia Natl Labs, Albuquerque, NM 87185 USA. [Capolino, Filippo] Univ Calif Irvine, Dept Elect Engn & Comp Sci, Irvine, CA 92697 USA. RP Campione, S (reprint author), Sandia Natl Labs, Ctr Integrated Nanotechnol, POB 5800, Albuquerque, NM 87185 USA.; Campione, S (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. EM sncampi@sandia.gov NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600185 ER PT S AU Chang, D Langrock, C Bennett, CV Fejer, MM AF Chang, Derek Langrock, Carsten Bennett, Corey V. Fejer, M. M. GP IEEE TI Complex-Transfer-Function Analysis of Optical-Frequency Converters SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID PHASE-MATCHING GRATINGS; 2ND-HARMONIC GENERATION; PULSE-COMPRESSION AB We measure the complex transfer function (CTF) of aperiodically poled lithium niobate waveguide devices and investigate the sources of CTF distortions, which are related to variations in the spatial distribution of the nonlinear coefficient and phase-mismatch profile. (C) 2014 Optical Society of America C1 [Chang, Derek; Langrock, Carsten; Fejer, M. M.] Stanford Univ, Edward L Ginzton Lab, Stanford, CA 94305 USA. [Chang, Derek; Bennett, Corey V.] Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Chang, D (reprint author), Stanford Univ, Edward L Ginzton Lab, Stanford, CA 94305 USA. EM djychang@stanford.edu NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908602361 ER PT S AU Chen, YH Alessi, D Drachenberg, D Pollock, B Albert, F Ralph, J Haefner, C AF Chen, Yu-hsin Alessi, David Drachenberg, Derrek Pollock, Bradley Albert, Felicie Ralph, Joseph Haefner, Constantin GP IEEE TI Increasing Laser Contrast by Relativistic Self-Guiding and its Application to Laser-Based Proton Acceleration SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB Laser-produced energetic protons via target normal sheath acceleration are deteriorated by amplified spontaneous emission (ASE). Here we test a new method of reducing ASE and increasing proton energy by relativistic self-guiding in the plasma. C1 [Chen, Yu-hsin; Alessi, David; Drachenberg, Derrek; Pollock, Bradley; Albert, Felicie; Ralph, Joseph; Haefner, Constantin] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Chen, YH (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM yhchen@umd.edu NR 7 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600213 ER PT S AU Chernikov, A Berkelbach, TC Hill, HM Rigosi, A Li, YL Aslan, OB Reichman, DR Hybertsen, MS Heinz, TF AF Chernikov, Alexey Berkelbach, Timothy C. Hill, Heather M. Rigosi, Albert Li, Yilei Aslan, Oezgur B. Reichman, David R. Hybertsen, Mark S. Heinz, Tony F. GP IEEE TI Excitons in atomically thin transition-metal dichalcogenides SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB Excitons are studied experimentally and theoretically in atomically thin WS2 layers. We find a binding energy of 0.32eV as well as non-hydrogenic behavior of the exciton states due to the non-uniformity of the dielectric environment. C1 [Chernikov, Alexey; Hill, Heather M.; Rigosi, Albert; Li, Yilei; Aslan, Oezgur B.; Heinz, Tony F.] Columbia Univ, Dept Phys, 538 W 120th St, New York, NY 10027 USA. [Chernikov, Alexey; Hill, Heather M.; Rigosi, Albert; Li, Yilei; Aslan, Oezgur B.; Heinz, Tony F.] Columbia Univ, Dept Elect Engn, New York, NY 10027 USA. [Berkelbach, Timothy C.; Reichman, David R.] Columbia Univ, Dept Chem, New York, NY 10027 USA. [Hybertsen, Mark S.] Brookhaven Natl Lab, Ctr Funct Nanomat, Upton, NY 11973 USA. RP Chernikov, A (reprint author), Columbia Univ, Dept Phys, 538 W 120th St, New York, NY 10027 USA.; Chernikov, A (reprint author), Columbia Univ, Dept Elect Engn, New York, NY 10027 USA. EM aac2183@columbia.edu NR 7 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600502 ER PT S AU Chini, M Wang, XW Cheng, Y Wang, H Wu, Y Cunningham, E Peng-Cheng-Li Heslar, J Telnov, DA Chu, SI Chang, ZH AF Chini, Michael Wang, Xiaowei Cheng, Yan Wang, He Wu, Yi Cunningham, Eric Peng-Cheng-Li Heslar, John Telnov, Dmitry A. Chu, Shih-I Chang, Zenghu GP IEEE TI Coherent VUV Emission from Field-Controlled Bound States SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID THRESHOLD HARMONICS; GENERATION AB We demonstrate a dramatic enhancement of the below-threshold harmonics in the vicinity of atomic resonances. The dependence on the driving laser carrier-envelope phase suggests a nonperturbative mechanism. Phase matching promises scalability to microJoule pulse energies. C1 [Chini, Michael; Wang, Xiaowei; Cheng, Yan; Wu, Yi; Cunningham, Eric; Chang, Zenghu] Univ Cent Florida, CREOL, Orlando, FL 32816 USA. [Chini, Michael; Wang, Xiaowei; Cheng, Yan; Wu, Yi; Cunningham, Eric; Chang, Zenghu] Univ Cent Florida, Dept Phys, Orlando, FL USA. [Wang, Xiaowei] Natl Univ Def Technol, Dept Phys, Changsha, Hunan, Peoples R China. [Wang, He] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. [Peng-Cheng-Li; Heslar, John; Chu, Shih-I] Natl Taiwan Univ, Ctr Quantum Sci & Engn, Taipei 10764, Taiwan. [Peng-Cheng-Li; Heslar, John; Chu, Shih-I] Natl Taiwan Univ, Dept Phys, Taipei, Taiwan. [Peng-Cheng-Li] Northwest Normal Univ, Coll Phys & Elect Engn, Lanzhou, Gansu, Peoples R China. [Telnov, Dmitry A.] St Petersburg State Univ, Dept Phys, St Petersburg 199034, Russia. [Chu, Shih-I] Univ Kansas, Dept Chem, Lawrence, KS 66045 USA. RP Chini, M (reprint author), Univ Cent Florida, CREOL, Orlando, FL 32816 USA. EM Zenghu.Chang@ucf.edu NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600250 ER PT S AU Cox, JA Lentine, AL Savignon, DJ Trotter, DC Starbuck, AL AF Cox, Jonathan A. Lentine, Anthony L. Savignon, Daniel J. Trotter, D. C. Starbuck, Andrew L. GP IEEE TI Wavelength Control of Resonant Photonic Modulators with Balanced Homodyne Locking SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We present a robust method for control of resonant modulator wavelength that is integrated with an on-chip balanced detector. Experimental results demonstrate long-term locking with low bit error rate over greater than 55 Kelvin. C1 [Cox, Jonathan A.; Lentine, Anthony L.; Savignon, Daniel J.; Trotter, D. C.; Starbuck, Andrew L.] Sandia Natl Labs, 1515 Eubank SE, Albuquerque, NM 87123 USA. RP Cox, JA (reprint author), Sandia Natl Labs, 1515 Eubank SE, Albuquerque, NM 87123 USA. EM jacox@sandia.gov NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908603059 ER PT S AU Cox, JA Siddiqui, A Rakich, PT Shin, H Jarecki, RL Starbuck, A AF Cox, Jonathan A. Siddiqui, Aleem Rakich, Peter T. Shin, Heeduk Jarecki, Robert L. Starbuck, Andrew GP IEEE TI Coherent Excitation of Multiple Nano-opto-mechanical Modes in Silicon with Ultrafast Time-domain Spectroscopy SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We present the first time-domain measurement of a guided-wave nano-opto-mechanical system, resulting in the coherent excitation of multiple mechanical modes. We deconvolved the electronic and mechanical responses to observe the evolution of the coherent superposition. C1 [Cox, Jonathan A.; Siddiqui, Aleem; Jarecki, Robert L.; Starbuck, Andrew] Sandia Natl Labs, 1515 Eubank SE, Albuquerque, NM 87123 USA. [Rakich, Peter T.; Shin, Heeduk] Yale Univ, New Haven, CT 06520 USA. RP Cox, JA (reprint author), Sandia Natl Labs, 1515 Eubank SE, Albuquerque, NM 87123 USA. EM jacox@sandia.gov 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 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908602132 ER PT S AU Craig, IM Taubman, MS Bernacki, BE Stahl, RD Schiffern, JT Myers, TL Cannon, BD Phillips, MC AF Craig, Ian M. Taubman, Matthew S. Bernacki, Bruce E. Stahl, Robert D. Schiffern, John T. Myers, Tanya L. Cannon, Bret D. Phillips, Mark C. GP IEEE TI Tunable Diode Laser Absorption Spectrometer for Detection of Hydrogen Fluoride Gas at Ambient Pressure SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We present a tunable diode laser absorption spectrometer (TDLAS) sensor for hydrogen fluoride (HF) detection at ambient pressure operating around the fundamental R(1) transition at 2.476 mu m. We achieve 38 ppt sensitivity for 1-s integration time. C1 [Craig, Ian M.; Taubman, Matthew S.; Bernacki, Bruce E.; Stahl, Robert D.; Schiffern, John T.; Myers, Tanya L.; Cannon, Bret D.; Phillips, Mark C.] Pacific NW Natl Lab, POB 999, Richland, WA 99354 USA. RP Craig, IM (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99354 USA. EM ian.craig@pnnl.gov NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908602216 ER PT S AU Demos, SG AF Demos, Stavros G. GP IEEE TI Methods for enhancing visualization of subsurface tissue structures in real time SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID OPTICAL POLARIZATION AB Methods and prototype instrumentation suitable for near surface imaging in tissues are presented. These methods are designed to address two main applications: a) vein imaging to assist cannulation and venipuncture of near surface veins; b) noncontact biometric identification using distinguishing traits in the human hand. C1 [Demos, Stavros G.] Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94551 USA. RP Demos, SG (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94551 USA. EM Demos1@llnl.gov 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 SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600047 ER PT S AU Fischer, AJ Xiao, XY Tsao, JY Koleske, DD Lu, P Wright, JB Liu, S Wang, GT AF Fischer, Arthur J. Xiao, Xiaoyin Tsao, Jeffrey Y. Koleske, Daniel D. Lu, Ping Wright, Jeremy B. Liu, Sheng Wang, George T. GP IEEE TI InGaN Quantum Dots for High Efficiency Blue and Green Light Emitters. SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID LASER AB InGaN quantum dots at high densities (similar to 10(11) dots/cm(2)) are demonstrated using metalorganic chemical vapor deposition combined with post growth processing of InGaN materials. Optical and structural studies are performed to characterize InGaN quantum dots. C1 [Fischer, Arthur J.; Xiao, Xiaoyin; Tsao, Jeffrey Y.; Koleske, Daniel D.; Lu, Ping; Wright, Jeremy B.; Liu, Sheng; Wang, George T.] Sandia Natl Labs, POB 5800, Albuquerque, NM 87047 USA. RP Fischer, AJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87047 USA. EM ajfisch@sandia.gov NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908602248 ER PT S AU Grice, W Pooser, R Williams, B AF Grice, W. Pooser, R. Williams, B. GP IEEE TI Quantum Repeater for Spectrally Entangled Photons SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We describe a quantum repeater architecture for spectrally entangled photons based on sum frequency. The repeater, which does not require a conventional quantum memory, includes a novel scheme for re-using unconverted photons. C1 [Grice, W.; Pooser, R.] Oak Ridge Natl Lab, Quantum Informat Sci Grp, Oak Ridge, TN 37831 USA. [Williams, B.] Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RP Grice, W (reprint author), Oak Ridge Natl Lab, Quantum Informat Sci Grp, Oak Ridge, TN 37831 USA. EM gricew@ornl.gov 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 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600461 ER PT S AU Grice, WP Evans, PG Lawrie, B Legre, M Lougovski, P Qi, B Ray, W Smith, M Williams, B AF Grice, W. P. Evans, P. G. Lawrie, B. Legre, M. Lougovski, P. Qi, B. Ray, W. Smith, M. Williams, B. GP IEEE TI Quantum Secret Sharing with Phase-Encoded Photons SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We demonstrate single-qubit quantum secret sharing using phase -encoded photons. The intelinediate node is designed to be inserted directly between Alice and Bob, with no need for additional compensation schemes. C1 [Grice, W. P.; Evans, P. G.; Lawrie, B.; Lougovski, P.; Qi, B.; Ray, W.; Smith, M.] Oak Ridge Natl Lab, Oak Ridge, TN USA. [Legre, M.] ID Quantique SA, Geneva, Switzerland. [Williams, B.] Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RP Grice, WP (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN USA. EM gricew@ornl.gov RI Qi, Bing/J-5028-2014 OI Qi, Bing/0000-0001-7723-8998 NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908601419 ER PT S AU Guclu, C Luk, TS Wang, GT Sinclair, MB Capolino, F AF Guclu, Caner Luk, Ting Shan Wang, George T. Sinclair, Michael B. Capolino, Filippo GP IEEE TI Enhancement of Radiative Emission using a Hyperbolic Metamaterial Nano-antenna SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB A hyperbolic metamaterial resonator is utilized as a nano-antenna for enhancing the radiative emission from a quantum emitter at 660 nm wavelength. Simulated power radiation enhancement up to 100 folds is demonstrated. C1 [Guclu, Caner; Capolino, Filippo] Univ Calif Irvine, Dept Elect Engn & Comp Sci, Irvine, CA 92697 USA. [Luk, Ting Shan; Wang, George T.; Sinclair, Michael B.] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Guclu, C (reprint author), Univ Calif Irvine, Dept Elect Engn & Comp Sci, Irvine, CA 92697 USA. EM f.capolino@uci.edu NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600221 ER PT S AU Habteyes, TG Staude, I Chong, KE Dominguez, J Decker, M Miroshnichenko, AE Kivshar, YS Brener, I AF Habteyes, Terefe G. Staude, Isabelle Chong, Katie E. Dominguez, Jason Decker, Manuel Miroshnichenko, Andrey E. Kivshar, Yuri S. Brener, Igal GP IEEE TI Apertureless Optical Near-Field Imaging of Localized Modes of Silicon Nanodisks SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID SCATTERING AB We measure near-field distributions of Mie-type optical modes of silicon nanodisks using apertureless near-field optical microscopy. Excellent agreement with numerical predictions is obtained, further enabling multipole analysis of the observed modes. C1 [Habteyes, Terefe G.] Univ New Mexico, Dept Chem & Chem Biol, Albuquerque, NM 87131 USA. [Habteyes, Terefe G.] Univ New Mexico, Ctr High Technol Mat, Albuquerque, NM 87131 USA. [Staude, Isabelle; Chong, Katie E.; Decker, Manuel; Miroshnichenko, Andrey E.; Kivshar, Yuri S.] Australian Natl Univ, Nonlinear Phys Ctr, Canberra, ACT 0200, Australia. [Dominguez, Jason; Brener, Igal] Sandia Natl Labs, Ctr Integrated Nanotechnol, Albuquerque, NM 87185 USA. RP Habteyes, TG (reprint author), Univ New Mexico, Dept Chem & Chem Biol, Albuquerque, NM 87131 USA. EM ips124@physics.anu.edu.au NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600486 ER PT S AU He, XW Fujimura, N Erickson, K Talin, AA Zhang, Q Gao, WL Kawano, Y Hauge, RH Leonard, F Kono, J AF He, Xiaowei Fujimura, Naoki Erickson, Kristopher Talin, A. Alec Zhang, Qi Gao, Weilu Kawano, Yukio Hauge, Robert H. Leonard, Francois Kono, Junichiro GP IEEE TI Terahertz Detector Based on a p-n Junction Film of Aligned Carbon Nanotubes SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We have developed a room temperature, broadband, and polarization-sensitive terahertz detector based on a p-n junction film of highly aligned and ultralong carbon nanotubes. Direct thermoelectric measurements demonstrate the photothermoelectirc nature of the detection mechanism. C1 [He, Xiaowei; Zhang, Qi; Gao, Weilu; Kono, Junichiro] Rice Univ, Dept Elect & Comp Engn, Houston, TX 77005 USA. [Fujimura, Naoki; Kawano, Yukio] Tokyo Inst Technol, Dept Phys Elect, Quantum Nanoelect Res Ctr, Tokyo 1528552, Japan. [Erickson, Kristopher; Talin, A. Alec; Leonard, Francois] Sandia Natl Labs, Livermore, CA 94551 USA. [Hauge, Robert H.] Rice Univ, Dept Chem, Houston, TX 77005 USA. [Hauge, Robert H.] King Abdulaziz Univ, Jeddah, Saudi Arabia. [Kono, Junichiro] Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA. [Kono, Junichiro] Rice Univ, Dept Mat Sci & NanoEngn, Houston, TX 77005 USA. RP He, XW (reprint author), Rice Univ, Dept Elect & Comp Engn, Houston, TX 77005 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600042 ER PT S AU Hernandez-Garcia, C Picon, A San Roman, J Plaja, L AF Hernandez-Garcia, Carlos Picon, Antonio San Roman, Julio Plaja, Luis GP IEEE TI Coherent Attosecond Beams Carrying Orbital Angular Momentum SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID LIGHT AB We present a theoretical study of high-order harmonic generation and propagation driven by an infrared field carrying orbital angular momentum (OAM). We show that extremeultraviolet high-OAM vortices with helical attosecond pulse structure are generated. C1 [Hernandez-Garcia, Carlos] Univ Colorado, JILA, Boulder, CO 80309 USA. [Hernandez-Garcia, Carlos] Univ Colorado, Dept Phys, Boulder, CO 80309 USA. [Hernandez-Garcia, Carlos; San Roman, Julio; Plaja, Luis] Univ Salamanca, Grp Invest Opt Extrema, E-37008 Salamanca, Spain. [Picon, Antonio] Argonne Natl Lab, Argonne, IL 60439 USA. RP Hernandez-Garcia, C (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA. EM carloshergar@usal.es RI Hernandez-Garcia, Carlos/G-3681-2011; Plaja, Luis/K-8701-2014 OI Hernandez-Garcia, Carlos/0000-0002-6153-2647; Plaja, Luis/0000-0001-8709-7295 NR 9 TC 0 Z9 0 U1 2 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908601401 ER PT S AU Hou, HM Zorba, V AF Hou, Huaming Zorba, Vassilia GP IEEE TI 3D chemical imaging of Li-ion batteries using femtosecond laser plasma spectroscopy SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We introduce the use of femtosecond laser plasma spectroscopy in chemical imaging of Li-ion battery system components. Spatially resolved mapping of major and minor elements of Li-ion batteries is presented and correlated to electrochemical performance. C1 [Hou, Huaming; Zorba, Vassilia] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Hou, HM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. EM vzormpa@lbl.gov NR 4 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908602124 ER PT S AU Hsieh, P Chung, C McMillan, JF Lu, M Panoiu, NC Wong, CW AF Hsieh, P. Chung, C. McMillan, J. F. Lu, M. Panoiu, N. C. Wong, C. W. GP IEEE TI Transport in millimeter scale disordered photonic crystals SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We examine the influence of disorder over millimeter lengthscales, in the transport of photons. Super-collimation is achieved for varying controlled degrees of disorder in large-scale measurements, supported by physical theory and simulations. C1 [Hsieh, P.; McMillan, J. F.; Wong, C. W.] Columbia Univ, Opt Nanostruct Lab, New York, NY 10027 USA. [Chung, C.] Natl Cheng Kung Univ, Ctr Micro Nano Sci & Technol, Tainan 701, Taiwan. [Lu, M.] Brookhaven Natl Lab, Ctr Funct Nanomat, Upton, NY 11973 USA. [Panoiu, N. C.] UCL, Dept Elect & Elect Engn, Photon Grp, London WC1E 7JE, England. RP Hsieh, P (reprint author), Columbia Univ, Opt Nanostruct Lab, New York, NY 10027 USA. EM ph2285@columbia.edu; cww2104@columbia.edu NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908603180 ER PT S AU Hsieh, P Chung, C McMillan, JF Lu, M Panoiu, NC Wong, CW AF Hsieh, P. Chung, C. McMillan, J. F. Lu, M. Panoiu, N. C. Wong, C. W. GP IEEE TI Photon transport and localization in optical superlattices SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID ANDERSON LOCALIZATION; LATTICES; CRYSTAL; LIGHT AB Here we examine the photon transport and collimation in optical superlattices, involving transverse guided resonances and disorder-induced localization. With increasing structural disorder, we observe the crossover from cascaded guided resonances into transverse localization modes. (C) 2011 Optical Society of America C1 [Hsieh, P.; McMillan, J. F.; Wong, C. W.] Columbia Univ, Opt Nanostruct Lab, New York, NY 10027 USA. [Chung, C.] Natl Cheng Kung Univ, Ctr Micor Nano Sci & Technol, Tainan 701, Taiwan. [Lu, M.] Brookhaven Natl Lab, Ctr Funct Nanomat, Upton, NY 11973 USA. [Panoiu, N. C.] UCL, Photon Grp, Dept Elect & Elect Engn, London WC1E 7JE, England. RP Hsieh, P (reprint author), Columbia Univ, Opt Nanostruct Lab, New York, NY 10027 USA. EM ph2285@columbia.edu; cww2104@columbia.edu 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 SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600290 ER PT S AU Hu, CY Deng, HX Rosenmann, D Czaplewski, DA Yang, XD Gao, J AF Hu, Changyu Deng, Huixu Rosenmann, Daniel Czaplewski, David A. Yang, Xiaodong Gao, Jie GP IEEE TI Experimental Demonstration of Near-Infrared Epsilon-Near-Zero Multilayer Metamaterial Slabs SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB Near-infrared epsilon-near-zero metamaterial slabs based on Ag-Ge multilayers are experimentally demonstrated and numerically analyzed. A post-annealing process and multilayer grating structures are introduced to reduce the optical loss and also tune the epsilon-near-zero wavelength. C1 [Hu, Changyu; Deng, Huixu; Yang, Xiaodong; Gao, Jie] Missouri Univ Sci & Technol, Dept Mech & Aerosp Engn, Rolla, MO 65409 USA. [Rosenmann, Daniel; Czaplewski, David A.] Argonne Natl Lab, Ctr Nanoscale Mat, Argonne, IL 60439 USA. RP Hu, CY (reprint author), Missouri Univ Sci & Technol, Dept Mech & Aerosp Engn, Rolla, MO 65409 USA. EM yangxia@mst.edu; gaojie@mst.edu NR 9 TC 0 Z9 0 U1 3 U2 4 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908601415 ER PT S AU Jain, A Tassin, P Koschny, T Soukoulis, CM AF Jain, Aditya Tassin, Philippe Koschny, Thomas Soukoulis, Costas M. GP IEEE TI Dielectric meta-atoms coupled by nonresonant metallic antennas: high-quality metamaterial resonances SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We demonstrate a new class of metamaterials with dielectric meta-atoms coupled to the incident waves by nonresonant metallic antennas. The storage of energy in the dielectric enables high-quality resonances in negative-permittivity and negative-permeability sheet metamaterials. (C) 2014 Optical Society of America C1 [Jain, Aditya; Tassin, Philippe; Koschny, Thomas; Soukoulis, Costas M.] US DOE, Ames Lab, Ames, IA 50011 USA. [Jain, Aditya; Tassin, Philippe; Koschny, Thomas; Soukoulis, Costas M.] Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. [Tassin, Philippe] Chalmers Univ, Dept Appl Phys, SE-41296 Gothenburg, Sweden. [Soukoulis, Costas M.] FORTH, IESL, Iraklion 71110, Crete, Greece. RP Jain, A (reprint author), US DOE, Ames Lab, Ames, IA 50011 USA. 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 SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600476 ER PT S AU Kinigstein, ED Huang, SW Sfeir, MY Koh, WK Murray, CB Heins, TF Wong, CW AF Kinigstein, E. D. Huang, S. -W. Sfeir, M. Y. Koh, W. -K. Murray, C. B. Heins, T. F. Wong, C. -W. GP IEEE TI Ultrafast Optical Properties of PbSe Nano-Rods: One Dimensional Excitons SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB Using Supercontinuum Transient Absorption Spectroscopy we observe new ultrafast exciton dynamics in PbSe Nanorods. We report distinct types of biexcitonic interactions, and propose a model to quantitatively describe the bleach using the predicted electronic structure. C1 [Kinigstein, E. D.; Huang, S. -W.; Wong, C. -W.] Columbia Univ, Ctr Integrated Sci & Engn Solid State Sci & Engn, Opt Nanostruct Lab, New York, NY 10027 USA. [Sfeir, M. Y.] Brookhaven Natl Lab, Ctr Funct Nanomat, Upton, NY 11973 USA. [Koh, W. -K.] Los Alamos Natl Lab, Phys Chem & Appl Spect Div, Los Alamos, NM USA. [Murray, C. B.] Univ Penn, Dept Chem, Philadelphia, PA 19104 USA. [Heins, T. F.] Columbia Univ, Dept Phys, New York, NY 10027 USA. RP Kinigstein, ED (reprint author), Columbia Univ, Ctr Integrated Sci & Engn Solid State Sci & Engn, Opt Nanostruct Lab, New York, NY 10027 USA. EM ek2539@columbia.edu; cww2104@columbia.edu NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600428 ER PT S AU Kioupakis, E Yan, QM Van de Walle, CG AF Kioupakis, Emmanouil Yan, Qimin Van de Walle, Chris G. GP IEEE TI Auger recombination in light-emitting materials SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB First-principles calculations show that phonon-assisted Auger recombination and its interplay with the polarization fields in polar nitride LEDs play an important role in the efficiency-droop and green-gap problems of these devices. C1 [Kioupakis, Emmanouil] Univ Michigan, Mat Sci & Engn, 2300 Hayward St, Ann Arbor, MI 48109 USA. [Kioupakis, Emmanouil; Yan, Qimin; Van de Walle, Chris G.] Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. [Yan, Qimin] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Mol Foundry, Berkeley, CA 94720 USA. RP Kioupakis, E (reprint author), Univ Michigan, Mat Sci & Engn, 2300 Hayward St, Ann Arbor, MI 48109 USA. EM kioup@umich.edu 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 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 1 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908602188 ER PT S AU Lawrie, BJ Pooser, RC AF Lawrie, B. J. Pooser, R. C. GP IEEE TI Ultrasensitive measurement of MEMS cantilever displacement below the photon shot noise limit SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We demonstrate sub-shot-noise microcantilever displacement sensitivity using simple differential measurements with multi-spatial-mode squeezed light, a result that may be critical for ultra-trace sensing and imaging applications. C1 [Lawrie, B. J.; Pooser, R. C.] Oak Ridge Natl Lab, Computat Sci & Engn Div, Quantum Informat Sci Grp, Oak Ridge, TN USA. RP Lawrie, BJ (reprint author), Oak Ridge Natl Lab, Computat Sci & Engn Div, Quantum Informat Sci Grp, Oak Ridge, TN USA. EM lwnebj@oral.gov 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 SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600206 ER PT S AU Leemans, WP Gonsalves, AJ Nakamura, K Mao, HS Toth, C Daniels, J Mittelberger, D Benedetti, C Bulanov, S Geddes, CGR Vay, JL Schroeder, CB Esarey, EH AF Leemans, W. P. Gonsalves, A. J. Nakamura, K. Mao, H. -S. Toth, C. Daniels, J. Mittelberger, D. Benedetti, C. Bulanov, S. Geddes, C. G. R. Vay, J. -L. Schroeder, C. B. Esarey, E. H. GP IEEE TI Laser plasma acceleration using the PW-class BELLA laser SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID ELECTRON-BEAMS AB Multi-GeV electron acceleration of electrons using intense laser pulses that excite multi-gigavolt fields in plasmas will be discussed. Experimental results with the new BELLA PW-class lasers and supporting simulations will be presented as well as a path forward to apply this acceleration method towards practical machines. C1 [Leemans, W. P.; Gonsalves, A. J.; Nakamura, K.; Mao, H. -S.; Toth, C.; Daniels, J.; Mittelberger, D.; Benedetti, C.; Bulanov, S.; Geddes, C. G. R.; Vay, J. -L.; Schroeder, C. B.; Esarey, E. H.] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, 1 Cyclotron Rd,MS 71-259, Berkeley, CA 94720 USA. [Leemans, W. P.; Mittelberger, D.; Bulanov, S.] Univ Calif Berkeley, Berkeley, CA 94720 USA. [Leemans, W. P.; Mittelberger, D.; Bulanov, S.] Eindhoven Univ Technol, POB 513, NL-5600 MB Eindhoven, Netherlands. RP Leemans, WP (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, 1 Cyclotron Rd,MS 71-259, Berkeley, CA 94720 USA. EM wpleemans@lbl.gov 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 SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908601115 ER PT S AU Li, CY Hurtado, A Wright, JB Xu, HW Liu, S Luk, TS Brener, I Brueck, SRJ Wang, GT AF Li, Changyi Hurtado, Antonio Wright, Jeremy B. Xu, Huiwen Liu, Sheng Luk, Ting Shan Brener, Igal Brueck, Steven R. J. Wang, George T. GP IEEE TI Gallium Nitride Nanotube Lasers SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID NANOWIRE LASERS AB Lasing is demonstrated from gallium nitride nanotubes fabricated using a two-step top-down technique. By optically pumping, we observed characteristics of lasing: a clear threshold, a narrow spectral, and guided emission from the nanotubes. C1 [Li, Changyi; Wright, Jeremy B.; Xu, Huiwen; Brueck, Steven R. J.] Univ New Mexico, Ctr High Technol Mat, 1313 Goddard St SE, Albuquerque, NM 87106 USA. [Hurtado, Antonio] Univ Essex, Sch Comp Sci & Elect Engn, Colchester CO4 3SQ, Essex, England. [Wright, Jeremy B.; Liu, Sheng; Luk, Ting Shan; Brener, Igal; Wang, George T.] Sandia Natl Labs, Albuquerque, NM 87185 USA. [Liu, Sheng; Luk, Ting Shan; Brener, Igal] Sandia Natl Labs, Ctr Integrated Nanotechnol, Albuquerque, NM 87185 USA. RP Li, CY (reprint author), Univ New Mexico, Ctr High Technol Mat, 1313 Goddard St SE, Albuquerque, NM 87106 USA. EM chyli@unm.edu NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908603292 ER PT S AU Li, LZ Schroder, T Chen, EH Walsh, M Bayn, I Gaathon, O Trusheim, ME Lu, M Mower, J Bakhru, H Markham, ML Twitchen, DJ Englund, D AF Li, Luozhou Schroeder, Tim Chen, Edward H. Walsh, Michael Bayn, Igal Gaathon, Ophir Trusheim, Matthew E. Lu, Ming Mower, Jacob Bakhru, Hassaram Markham, Matthew L. Twitchen, Daniel J. Englund, Dirk GP IEEE TI Demonstration of a NV spin qubit interacting with a cavity mode in the Purcell regime SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID DIAMOND AB We demonstrate an over-80-fold enhancement of an NV's zero-phonon line emission inside cavity in the Purcell regime within a high-purity, electronic-grade diamond substrate. This system is a promising building block for quantum networks. (C) 2014 Optical Society of America C1 [Li, Luozhou; Schroeder, Tim; Chen, Edward H.; Walsh, Michael; Bayn, Igal; Gaathon, Ophir; Trusheim, Matthew E.; Mower, Jacob; Englund, Dirk] MIT, Dept Elect Engn & Comp Sci, Cambridge, MA 02139 USA. [Li, Luozhou; Bayn, Igal] Columbia Univ, Dept Elect Engn, New York, NY 10027 USA. [Lu, Ming] Brookhaven Natl Lab, Ctr Funct Nanomat, Upton, NY 11973 USA. [Bakhru, Hassaram] SUNY Albany, Coll Nanoscale Sci & Engn, Albany, NY 12203 USA. [Markham, Matthew L.; Twitchen, Daniel J.] Element Six Ltd, Ascot SL5 8BP, Berks, England. RP Li, LZ (reprint author), MIT, Dept Elect Engn & Comp Sci, Cambridge, MA 02139 USA. EM ll2670@columbia.edu NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908601011 ER PT S AU Liu, S Sinclair, MB Mahony, TS Jun, YC Campione, S Ginn, J Bender, DA Wendt, JR Ihlefeld, JF Clem, PG Wright, JB Brener, I AF Liu, S. Sinclair, M. B. Mahony, T. S. Jun, Y. C. Campione, S. Ginn, J. Bender, D. A. Wendt, J. R. Ihlefeld, J. F. Clem, P. G. Wright, J. B. Brener, I. GP IEEE TI Optical Magnetic Mirrors using All Dielectric Metasurfaces SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We experimentally demonstrate the magnetic mirror behavior of all-dielectric metasurfaces at optical frequencies through phase measurements using time-domain-spectroscopy. The unique boundary conditions of magnetic mirrors can lead to advances in sensors, photodetectors and light sources. C1 [Liu, S.; Sinclair, M. B.; Mahony, T. S.; Jun, Y. C.; Campione, S.; Ginn, J.; Bender, D. A.; Wendt, J. R.; Ihlefeld, J. F.; Clem, P. G.; Wright, J. B.; Brener, I.] Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. [Liu, S.; Mahony, T. S.; Jun, Y. C.; Campione, S.; Brener, I.] Sandia Natl Labs, Ctr Integrated Nanotechnol, Albuquerque, NM 87185 USA. RP Liu, S (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA.; Liu, S (reprint author), Sandia Natl Labs, Ctr Integrated Nanotechnol, Albuquerque, NM 87185 USA. EM snliu@sandia.gov NR 5 TC 0 Z9 0 U1 3 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600188 ER PT S AU Liu, S Li, BS Luk, TS Fan, HY Brener, I Sinclair, MB AF Liu, Sheng Li, Binsong Luk, Ting Shan Fan, Hongyou Brener, Igal Sinclair, Michael B. GP IEEE TI Investigation of Quantum Dot-Quantum Dot Coupling at High Hydrostatic Pressure SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID CDSE NANOCRYSTALS; TRANSFORMATION; DEPENDENCE; WURTZITE AB We performed photoluminescence and radiative lifetime measurements of quantum dots (QDs) showing different carrier dynamic mechanisms at elevated pressures that could reveal the inter-QD coupling as the QDs spacing decreases with increasing hydrostatic pressure. C1 [Liu, Sheng; Li, Binsong; Luk, Ting Shan; Fan, Hongyou; Brener, Igal; Sinclair, Michael B.] Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. [Liu, Sheng; Brener, Igal] Sandia Natl Labs, Ctr Integrated Nanotechnol, Albuquerque, NM 87185 USA. RP Liu, S (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM snliu@sandia.gov NR 4 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600426 ER PT S AU Liu, XZ Appavoo, K Sfeir, MY Kena-Cohen, S Menon, VM AF Liu, Xiaoze Appavoo, Kannatassen Sfeir, Matthew Y. Kena-Cohen, Stephan Menon, Vinod M. GP IEEE TI Stimulated polariton emission from ZnO-nanoparticles based microcavity SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We demonstrate stimulated polariton emission at room temperature in a dielectric microcavity embedded with ZnO nanoparticles. The polariton lifetime is also shown to decrease drastically above the stimulated emission threshold. C1 [Liu, Xiaoze; Menon, Vinod M.] CUNY, Grad Sch, Dept Phys, New York, NY 10016 USA. [Liu, Xiaoze; Menon, Vinod M.] CUNY, Univ Ctr, New York, NY 10016 USA. [Liu, Xiaoze; Menon, Vinod M.] CUNY Queens Coll, Dept Phys, Lab Nano & Micro Photon, New York, NY USA. [Appavoo, Kannatassen; Sfeir, Matthew Y.] Brookhaven Natl Lab, Ctr Funct Nanomat, Upton, NY 11973 USA. [Kena-Cohen, Stephan] Ecole Polytech Montreal, Dept Engn Phys, Montreal, PQ, Canada. RP Liu, XZ (reprint author), CUNY, Grad Sch, Dept Phys, New York, NY 10016 USA. EM vmenon@qc.cuny.edu NR 4 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908603208 ER PT S AU Lougovski, P Pooser, R AF Lougovski, Pavel Pooser, Raphael GP IEEE TI Adaptive Binning and On-line Certification of Quantum Random Number Generators Using Bayesian Inference SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB Quantum random number generator statistics fluctuates with time due to noise affecting quality of randomness. We use Bayesian inference to monitor the statistics after each measurement and bin data adaptively to mitigate effects of noise. (C) 2014 Optical Society of America C1 [Lougovski, Pavel; Pooser, Raphael] Oak Ridge Natl Lab, Quantum Informat Sci Grp, One Bethel Valley Rd,POB 2008,MS 6085, Oak Ridge, TN 37831 USA. RP Lougovski, P (reprint author), Oak Ridge Natl Lab, Quantum Informat Sci Grp, One Bethel Valley Rd,POB 2008,MS 6085, Oak Ridge, TN 37831 USA. EM lougovskip@ornl.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908601142 ER PT S AU Ma, RM Ota, S Li, YM Yang, S Zhang, X AF Ma, Ren-Min Ota, Sadao Li, Yimin Yang, Sui Zhang, Xiang GP IEEE TI Active Surface Plasmon Sensor SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID NANOPARTICLES; SENSITIVITY; RESONANCES; BIOSENSORS AB we have experimentally demonstrated an active plasmon sensor with sub-p.p.b. level explosive molecules detection. Loss compensation by gain in surface plasmon cavity enhanced the sensitivity significantly. C1 [Ma, Ren-Min; Ota, Sadao; Li, Yimin; Yang, Sui; Zhang, Xiang] Univ Calif Berkeley, NSF Nanoscale Sci & Engn Ctr, 3112 Etcheverry Hall, Berkeley, CA 94720 USA. [Zhang, Xiang] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Zhang, X (reprint author), Univ Calif Berkeley, NSF Nanoscale Sci & Engn Ctr, 3112 Etcheverry Hall, Berkeley, CA 94720 USA. EM xiang@berkeley.edu RI Yang, Sui /H-4417-2016 NR 20 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600308 ER PT S AU Macfaden, AJ Reno, JL Brener, I Mitrofanov, O AF Macfaden, Alexander J. Reno, John L. Brener, Igal Mitrofanov, Oleg GP IEEE TI Transmission of THz pulses through 3 mu m apertures: applications for near-field microscopy SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We demonstrate that THz pulses transmitted through small apertures (similar to lambda/100) exhibit strong evanescent components within 1 mu m of the aperture. Using this effect, we developed subwavelength aperture THz near-field probes that provide 3 mu m resolution. C1 [Macfaden, Alexander J.; Mitrofanov, Oleg] UCL, Elect & Elect Engn, Torrington Pl, London WC1E 7JE, England. [Reno, John L.; Brener, Igal] Sandia Natl Labs, Ctr Integrated Technol, Albuquerque, NM 87185 USA. [Reno, John L.; Brener, Igal; Mitrofanov, Oleg] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Macfaden, AJ (reprint author), UCL, Elect & Elect Engn, Torrington Pl, London WC1E 7JE, England. EM o.mitrofanov@ucl.ac.uk RI Mitrofanov, Oleg/C-1938-2008 OI Mitrofanov, Oleg/0000-0003-3510-2675 NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908603024 ER PT S AU Majumdar, A Wu, SF Buckley, S Jones, AM Ross, JS Ghimire, NJ Yan, JQ Mandrus, DC Yao, W Hatami, F Vuckovic, J Xu, XD AF Majumdar, Arka Wu, Sanfeng Buckley, Sonia Jones, Aaron M. Ross, Jason S. Ghimire, Nirinal J. Yan, Jiaqiang Mandrus, David C. Yao, Wang Hatami, Fariba Vuckovic, Jelena Xu, Xiaodong GP IEEE TI 2D-material Based Nano-photonics SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We demonstrate a nanophotonic platform based on 2D materials coupled to photonic crystal cavities. We show strong enhancement (similar to 60 times) of light emission due to the photonic crystal. (C) 2014 Optical Society of America C1 [Majumdar, Arka] Univ Washington, Dept Elect Engn, Seattle, WA 98195 USA. [Wu, Sanfeng; Jones, Aaron M.; Xu, Xiaodong] Univ Washington, Dept Phys, Seattle, WA 98195 USA. [Buckley, Sonia; Vuckovic, Jelena] Stanford Univ, Ginzton Lab, Stanford, CA 94305 USA. [Ross, Jason S.; Xu, Xiaodong] Univ Washington, Dept Mat Sci & Engn, Seattle, WA 98195 USA. [Ghimire, Nirinal J.; Mandrus, David C.] Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. [Ghimire, Nirinal J.; Yan, Jiaqiang; Mandrus, David C.] Oak Ridge Natl Lab, Mat Sci & Technol Div, Oak Ridge, TN 37831 USA. [Yan, Jiaqiang; Mandrus, David C.] Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. [Yao, Wang] Univ Hong Kong, Dept Phys, Hong Kong, Hong Kong, Peoples R China. [Yao, Wang] Univ Hong Kong, Ctr Theoret & Computat Phys, Hong Kong, Hong Kong, Peoples R China. [Hatami, Fariba] Humboldt Univ, Dept Phys, D-12489 Berlin, Germany. RP Majumdar, A (reprint author), Univ Washington, Dept Elect Engn, Seattle, WA 98195 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908602380 ER PT S AU Melgaard, SD Albrecht, A Hehlen, M Seletskiy, DV Sheik-Bahae, M AF Melgaard, Seth D. Albrecht, Alexander Hehlen, Markus Seletskiy, Denis V. Sheik-Bahae, Mansoor GP IEEE TI Optical refrigeration cools below 100K SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We report a milestone in optical refrigeration, cooling a 10% Yb:YLF crystal to 93K (Delta T similar to 180K); obtaining the coldest solid-state temperature to date. Identification of transition metal impurities via mass spectrometry allows further cooling through purification. C1 [Melgaard, Seth D.; Albrecht, Alexander; Sheik-Bahae, Mansoor] Univ New Mexico, Dept Phys & Astron, 800 Yale Blvd NE, Albuquerque, NM 87131 USA. [Melgaard, Seth D.] Kirtland AFB, Air Force Res Lab, Albuquerque, NM USA. [Hehlen, Markus] Los Alamos Natl Lab, Los Alamos, NM USA. [Seletskiy, Denis V.] Univ Konstanz, Dept Phys, D-78457 Constance, Germany. [Seletskiy, Denis V.] Univ Konstanz, Ctr Appl Photon, D-78457 Constance, Germany. RP Melgaard, SD (reprint author), Univ New Mexico, Dept Phys & Astron, 800 Yale Blvd NE, Albuquerque, NM 87131 USA. EM Melgaard@unm.edu 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 SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600435 ER PT S AU Mrejen, M Jha, PK Kim, J Wu, C Wang, Y Yin, X Zhang, X AF Mrejen, M. Jha, P. K. Kim, J. Wu, C. Wang, Y. Yin, X. Zhang, X. GP IEEE TI Interacting dark resonances with metallic nano-antennas SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We theoretically investigate interacting dark resonances in a plasmonic meta-molecule comprising a bright nano-antenna coupled to cascaded dark elements. This structure enables efficient energy transfer and exhibits sub-natural spectral response analogous to the atomic counterpart. C1 [Mrejen, M.; Jha, P. K.; Kim, J.; Wu, C.; Wang, Y.; Yin, X.; Zhang, X.] Univ Calif Berkeley, NSF Nanoscale Sci & Engn Ctr NEC, 3112 Etcheverry Hall, Berkeley, CA 94720 USA. [Zhang, X.] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Mrejen, M (reprint author), Univ Calif Berkeley, NSF Nanoscale Sci & Engn Ctr NEC, 3112 Etcheverry Hall, Berkeley, CA 94720 USA. EM michael.mrejen@berkeley.edu RI Yin, Xiaobo/A-4142-2011 NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600270 ER PT S AU Neshev, DN Staude, I Fofang, NT Liu, S Dominguez, J Decker, M Miroshnichenko, AE Khardikov, VV Luk, TS Brener, I Kivshar, YS AF Neshev, Dragomir N. Staude, Isabelle Fofang, Nche T. Liu, Sheng Dominguez, Jason Decker, Manuel Miroshnichenko, Andrey E. Khardikov, Vyacheslav V. Luk, Ting S. Brener, Igal Kivshar, Yuri S. GP IEEE TI Shaping Emission Spectra of Quantum Dots by All-dielectric Metasurfaces SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID NANOPARTICLES; SCATTERING AB Silicon nanodisks support both electric and magnetic resonances, which can be tuned independently via their geometry. We utilize these engineered resonances and demonstrate dielectric metasurfaces for efficient shaping of the emission spectra of quantum dots. C1 [Neshev, Dragomir N.; Staude, Isabelle; Decker, Manuel; Miroshnichenko, Andrey E.; Kivshar, Yuri S.] Australian Natl Univ, Nonlinear Phys Ctr, GPO Box 4, Canberra, ACT 0200, Australia. [Fofang, Nche T.; Liu, Sheng; Dominguez, Jason; Luk, Ting S.; Brener, Igal] Sandia Natl Labs, Ctr Integrated Nanotechnol, Albuquerque, NM 87185 USA. [Khardikov, Vyacheslav V.] Natl Acad Sci Ukraine, Inst Radioastron, UA-61002 Kharkov, Ukraine. RP Neshev, DN (reprint author), Australian Natl Univ, Nonlinear Phys Ctr, GPO Box 4, Canberra, ACT 0200, Australia. EM dnn124@physics.anu.edu.au RI Neshev, Dragomir/A-3759-2008 OI Neshev, Dragomir/0000-0002-4508-8646 NR 6 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908601027 ER PT S AU Roberts, C Law, S Kilpatrick, T Yu, L Ribaudo, T Shaner, E Wasserman, D Podolskiy, V AF Roberts, Christopher Law, Stephanie Kilpatrick, Torin Yu, Lan Ribaudo, Troy Shaner, Eric Wasserman, Daniel Podolskiy, Viktor GP IEEE TI All Semiconductor Negative-Index Plasmonic Absorbers SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID REFRACTION AB We demonstrate all-semiconductor thin-film plasmonic absorbers, where strong absorption in these structures is linked to the excitation of highly-confined negative-index surface plasmon polaritons. We present numerical and analytical descriptions of guided modes of the system. (C) 2014 Optical Society of America C1 [Roberts, Christopher; Podolskiy, Viktor] Univ Massachusetts, Dept Phys & Appl Phys, Lowell, MA 01854 USA. [Ribaudo, Troy; Shaner, Eric] Sandia Natl Labs, Albuquerque, NM 87185 USA. [Law, Stephanie; Kilpatrick, Torin; Yu, Lan; Wasserman, Daniel] Univ Illinois, Dept Elect & Comp Engn, Micro & Nanotechnol Lab, Urbana, IL 61801 USA. RP Roberts, C (reprint author), Univ Massachusetts, Dept Phys & Appl Phys, Lowell, MA 01854 USA. EM christopher_roberts@student.uml.edu 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 SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600219 ER PT S AU Roth, M Jung, D Falk, K Guler, N Bagnoud, V Bedacht, S Deppert, O Devlin, M Favalli, A Fernandez, J Gautier, D Geissel, M Haight, R Hamilton, CE Hegelich, BM Johnson, RP Kleinschmidt, A Merrill, F Ortner, A Schaumann, G Schoenberg, K Schollmeier, M Shimada, T Taddeucci, T Tebartz, A Tybo, JL Wagner, F Wender, SA Wilde, CH Wurden, GA AF Roth, M. Jung, D. Falk, K. Guler, N. Bagnoud, V. Bedacht, S. Deppert, O. Devlin, M. Favalli, A. Fernandez, J. Gautier, D. Geissel, M. Haight, R. Hamilton, C. E. Hegelich, B. M. Johnson, R. P. Kleinschmidt, A. Merrill, F. Ortner, A. Schaumann, G. Schoenberg, K. Schollmeier, M. Shimada, T. Taddeucci, T. Tebartz, A. Tybo, J. L. Wagner, F. Wender, S. A. Wilde, C. H. Wurden, G. A. GP IEEE TI High energy ion acceleration and neutron production using relativistic transparency in solids SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID LASER IRRADIATION; TARGETS; BEAMS AB Neutrons are unique to diagnose materials and excite nuclear reactions with a large field of applications. For the first time a new ion acceleration mechanism ( BOA) has been used to generate intense, directed neutron beams. C1 [Roth, M.; Bedacht, S.; Deppert, O.; Kleinschmidt, A.; Ortner, A.; Schaumann, G.; Tebartz, A.; Wagner, F.] Tech Univ Darmstadt, Inst Kernphys, Schlossgartenstr 9, D-64289 Darmstadt, Germany. [Jung, D.; Falk, K.; Guler, N.; Devlin, M.; Favalli, A.; Fernandez, J.; Gautier, D.; Haight, R.; Hamilton, C. E.; Hegelich, B. M.; Johnson, R. P.; Merrill, F.; Schoenberg, K.; Shimada, T.; Taddeucci, T.; Tybo, J. L.; Wender, S. A.; Wilde, C. H.; Wurden, G. A.] Los Alamos Natl Lab, Los Alamos, NM 87545 USA. [Bagnoud, V.] Helmholtzzentrum Schwerionenforsch GSI, D-64291 Darmstadt, Germany. [Geissel, M.; Schollmeier, M.] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Roth, M (reprint author), Tech Univ Darmstadt, Inst Kernphys, Schlossgartenstr 9, D-64289 Darmstadt, Germany. EM markus.roth@physik.tu-darmstadt.de RI Wurden, Glen/A-1921-2017 OI Wurden, Glen/0000-0003-2991-1484 NR 15 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600210 ER PT S AU Sakai, Y Pogorelsky, I Fedurin, M Musumeci, P Duris, J Williams, O Rosenzweig, J AF Sakai, Y. Pogorelsky, I. Fedurin, M. Musumeci, P. Duris, J. Williams, O. Rosenzweig, J. GP IEEE TI 3rd order harmonic in inverse Compton scattering SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID NONLINEAR THOMSON SCATTERING AB We report observations of strong-field effects in inverse Compton scattering via its Xray characteristics using K-, L-edge, and attenuation filters. A CO2 laser of a(0) approximate to 0.6 is collided by a 65-MeV electron beam. C1 [Sakai, Y.; Musumeci, P.; Duris, J.; Williams, O.; Rosenzweig, J.] Univ Calif Los Angeles, Los Angeles, CA 90095 USA. [Pogorelsky, I.; Fedurin, M.] Brookhaven Natl Lab, Upton, NY 11973 USA. RP Sakai, Y (reprint author), Univ Calif Los Angeles, Los Angeles, CA 90095 USA. 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 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908601250 ER PT S AU Salandrino, A Cang, H Wang, Y Zhang, X AF Salandrino, Alessandro Cang, Hu Wang, Yuan Zhang, Xiang GP IEEE TI Sub-diffraction Imaging via Surface Plasmon Decompression SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID OPTICAL HYPERLENS; LIMIT AB We theoretically propose a novel scheme for sub-diffraction imaging based on a process of adiabatic decompression of the local wavelength of a surface plasmon polariton supported by two adjoining curved metal surfaces. C1 [Salandrino, Alessandro; Wang, Yuan; Zhang, Xiang] Univ Calif Berkeley, NSF Nanoscale Sci & Engn Ctr NSEC, Berkeley, CA 94720 USA. [Cang, Hu] Salk Inst Biol Studies, Waitt Adv Biophoton Ctr, San Diego, CA 92138 USA. [Zhang, Xiang] Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA USA. RP Zhang, X (reprint author), Univ Calif Berkeley, NSF Nanoscale Sci & Engn Ctr NSEC, Berkeley, CA 94720 USA. EM xzhang@me.berkeley.edu 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 SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600482 ER PT S AU Sandberg, RL Bolme, C Ramos, K McCulloch, Q Martinez, R Hamilton, V Pierce, T Greenfield, M McGrane, S Barber, JL Abbey, B Schropp, A Seiboth, F Heiman, P Nagler, B Galtier, E Granados, E AF Sandberg, R. L. Bolme, C. Ramos, K. McCulloch, Q. Martinez, R. Hamilton, V. Pierce, T. Greenfield, M. McGrane, S. Barber, J. L. Abbey, B. Schropp, A. Seiboth, F. Heiman, P. Nagler, B. Galtier, E. Granados, E. GP IEEE TI Ultrafast Imaging of Shocked Material Dynamics with X-ray Fee Electron Laser Pulses SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We present the first single-shot images of a laser-driven shock wave interacting with micron-scale materials inhomogeneities taken with an X-ray free electron laser. Materials dynamics under high strain-rate loading is important to a range of problems. C1 [Sandberg, R. L.; Bolme, C.; Ramos, K.; McCulloch, Q.; Martinez, R.; Hamilton, V.; Pierce, T.; Greenfield, M.; McGrane, S.; Barber, J. L.] Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. [Abbey, B.] La Trobe Univ, Dept Phys, Melbourne, Vic, Australia. [Schropp, A.; Seiboth, F.] Tech Univ Dresden, Inst Struct Phys, D-01062 Dresden, Germany. [Heiman, P.; Nagler, B.; Galtier, E.; Granados, E.] SLAC Natl Accelerator Lab, Menlo Pk, CA 94025 USA. RP Sandberg, RL (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM sandberg@lanl.gov NR 3 TC 0 Z9 0 U1 2 U2 5 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908603080 ER PT S AU Schuck, J AF Schuck, James GP IEEE TI Nano-Optical Scan Probes: Opening Doors to Previously-Inaccessible Parameter Spaces SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA C1 [Schuck, James] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Schuck, J (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 1 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908603307 ER PT S AU Schuck, J AF Schuck, James GP IEEE TI Nano-Optical Scan Probes: Opening Doors to Previously-Inaccessible Parameter Spaces SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA C1 [Schuck, James] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Schuck, J (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 1 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600098 ER PT S AU Seo, M Yamaguchi, H Mohite, A Boubanga-Tombet, S Taylor, AJ Prasankumar, RP AF Seo, Minah Yamaguchi, Hisato Mohite, Aditya Boubanga-Tombet, Stephane Taylor, Antoinette J. Prasankumar, Rohit P. GP IEEE TI Ultrafast optical microscopy of single monolayer molybdenum disulfide flakes SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID NANOWIRES AB We use ultrafast optical microscopy to investigate carrier dynamics in single flakes of atomically thin molybdenum disulfide. By tuning the probe wavelength through the bandgap, we reveal the influence of layer thickness on carrier dynamics. (C)2014 Optical Society of America C1 [Seo, Minah; Yamaguchi, Hisato; Mohite, Aditya; Boubanga-Tombet, Stephane; Taylor, Antoinette J.; Prasankumar, Rohit P.] Los Alamos Natl Lab, Ctr Integrated Nanotechnol, Los Alamos, NM 87545 USA. RP Seo, M (reprint author), Korea Inst Sci & Technol, Sensor Syst Res Ctr, Seoul, South Korea. EM mseo@kist.re.kr 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 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600501 ER PT S AU Shcherbakov, MR Neshev, DN Shorokhov, AS Staude, I Melik-Gaykazyan, EV Hopkins, B Dominguez, J Miroshnichenko, A Brener, I Fedyanin, AA Kivshar, YS AF Shcherbakov, Maxim R. Neshev, Dragomir N. Shorokhov, Alexander S. Staude, Isabelle Melik-Gaykazyan, Elizaveta V. Hopkins, Ben Dominguez, Jason Miroshnichenko, Andrey Brener, Igal Fedyanin, Andrey A. Kivshar, Yuri S. GP IEEE TI Third-harmonic spectroscopy of all-dielectric oligomers with both electric and magnetic resonances SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We characterize experimentally the nonlinear optical response of silicon nanodisk oligomers using third-harmonic generation spectroscopy and reveal the contributions of magnetic and electric dipolar resonances, local field enhancement, and nonlinear interference. (C) 2014 Optical Society of America C1 [Shcherbakov, Maxim R.; Shorokhov, Alexander S.; Melik-Gaykazyan, Elizaveta V.; Fedyanin, Andrey A.] Moscow MV Lomonosov State Univ, Fac Phys, Moscow, Russia. [Neshev, Dragomir N.; Staude, Isabelle; Hopkins, Ben; Miroshnichenko, Andrey; Kivshar, Yuri S.] Australian Natl Univ, Res Sch Phys & Engn, Nonlinear Phys Ctr, Canberra, ACT 2602, Australia. [Dominguez, Jason; Brener, Igal] Sandia Natl Labs, Ctr Integrated Nanotechnol, Albuquerque, NM 87185 USA. RP Shcherbakov, MR (reprint author), Moscow MV Lomonosov State Univ, Fac Phys, Moscow, Russia. EM shcherbakov@nanolab.phys.msu.ru RI Shorokhov, Alexander/H-5523-2015; Neshev, Dragomir/A-3759-2008; Melik-Gaykazyan, Elizaveta/J-9073-2015 OI Neshev, Dragomir/0000-0002-4508-8646; Melik-Gaykazyan, Elizaveta/0000-0001-7633-2376 NR 5 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600403 ER PT S AU Sheu, YM Trugman, SA Yan, L Jia, QX Taylor, AJ Prasankumar, RP AF Sheu, Yu-Miin Trugman, Stuart A. Yan, Li Jia, Quanxi Taylor, Antoinette J. Prasankumar, Rohit P. GP IEEE TI Ultrafast optical manipulation of interfacial magnetoelectric coupling SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID MULTIFERROICS AB We demonstrate a new paradigm for all-optical detection and control of interfacial magnetoelectric coupling on ultrafast timescales, achieved by using time-resolved second harmonic generation (SHG) in a ferroelectric/ferromagnet oxide heterostructure. (C) 2014 Optical Society of America C1 [Sheu, Yu-Miin; Trugman, Stuart A.; Yan, Li; Jia, Quanxi; Taylor, Antoinette J.; Prasankumar, Rohit P.] Los Alamos Natl Lab, Ctr Integrated Nanotechnol, MS K771, Los Alamos, NM 87545 USA. RP Sheu, YM (reprint author), Los Alamos Natl Lab, Ctr Integrated Nanotechnol, MS K771, Los Alamos, NM 87545 USA. EM ymsheu@lanl.gov; rpprasan@lanl.gov NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600320 ER PT S AU Shi, ZW Jin, CH Yang, W Bechtel, HA Martin, MC Zhang, GY Wang, F AF Shi, Zhiwen Jin, Chenhao Yang, Wei Bechtel, Hans A. Martin, Michael C. Zhang, Guangyu Wang, Feng GP IEEE TI Optical Spectroscopy of Graphene/Boron Nitride Hetrostructures SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID BORON-NITRIDE AB Electrons in graphene are described by massless Dirac Fermions with unusual electrical and optical properties. The Moire superlattice in graphene/boron nitride heterostructure strongly modifies the electronic structure, and leads to unusual changes in infrared absorption. C1 [Shi, Zhiwen; Jin, Chenhao; Wang, Feng] Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. [Yang, Wei; Zhang, Guangyu] Chinese Acad Sci, Beijing Natl Lab Condensed Matter Phys, Beijing 100190, Peoples R China. [Yang, Wei; Zhang, Guangyu] Chinese Acad Sci, Inst Phys, Beijing 100190, Peoples R China. [Bechtel, Hans A.; Martin, Michael C.] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Adv Light Source Div, Berkeley, CA 94720 USA. [Wang, Feng] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Shi, ZW (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600261 ER PT S AU Siddiqui, A Jarecki, RL Starbuck, A Cox, JA AF Siddiqui, Aleem Jarecki, Robert L. Starbuck, Andrew Cox, Jonathan A. GP IEEE TI Ultra-Long Duration Time-Resolved Spectroscopy with Enhanced Temporal Resolution of High-Q Nano-Optomechanical Modes using Interleaved Asynchronous Optical Sampling (I-ASOPS) SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB Transient responses of high-Q nano-optomechanical modes are characterized with Interleaved-ASOPS, where pump-induced transients are interrogated with multiple probe pulses. Temporal resolution increases linearly with probe-pulse-number beyond conventional ASOPS, achieving sub-ps resolution over mu s durations. C1 [Siddiqui, Aleem; Jarecki, Robert L.; Starbuck, Andrew; Cox, Jonathan A.] Sandia Natl Labs, 1515 Eubank SE, Albuquerque, NM 87123 USA. RP Siddiqui, A (reprint author), Sandia Natl Labs, 1515 Eubank SE, Albuquerque, NM 87123 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 SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908602455 ER PT S AU Singh, A Moody, G Wu, SF Wu, YW Ghimire, NJ Yan, JQ Mandrus, DG Xu, XD Li, XQ AF Singh, Akshay Moody, Galan Wu, Sanfeng Wu, Yanwen Ghimire, Nirmal J. Yan, Jiaqiang Mandrus, David G. Xu, Xiaodong Li, Xiaoqin GP IEEE TI Coherent Electronic Coupling in Transition Metal Dichalcogenide Monolayer SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We present two-color pump-probe spectra of excitons and trions in monolayer MoSe2. Isolated spectral cross-peaks reveal coherent exciton-trion coupling due to many-body interactions. Density matrix calculations suggest the formation of a correlated exciton-trion state. (C) 2014 Optical Society of America C1 [Singh, Akshay; Moody, Galan; Wu, Yanwen; Li, Xiaoqin] Univ Texas Austin, Dept Phys, Austin, TX 78712 USA. [Wu, Sanfeng; Xu, Xiaodong] Univ Washington, Dept Phys, Seattle, WA 98195 USA. [Wu, Yanwen] Univ S Carolina, Dept Phys & Astron, Columbia, SC 29208 USA. [Ghimire, Nirmal J.; Mandrus, David G.] Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. [Ghimire, Nirmal J.; Yan, Jiaqiang; Mandrus, David G.] Oak Ridge Natl Lab, Div Mat Sci & Technol, Oak Ridge, TN 37831 USA. [Yan, Jiaqiang; Mandrus, David G.] Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. [Xu, Xiaodong] Univ Washington, Dept Mat Sci & Engn, Seattle, WA 98195 USA. RP Li, XQ (reprint author), Univ Texas Austin, Dept Phys, Austin, TX 78712 USA. EM elaineli@physics.utexas.edu NR 6 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600503 ER PT S AU Sun, B Singh, R Padilha, LA Bae, WK Pietryga, JM Klimov, VI Cundiff, ST AF Sun, B. Singh, R. Padilha, L. A. Bae, W. K. Pietryga, J. M. Klimov, V. I. Cundiff, S. T. GP IEEE TI Two Dimensional Coherent Spectroscopy of CdSe/ZnS Colloidal Quantum Dots SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We demonstrate 2D coherent spectroscopy of CdSe/ZnS nanocrystals and measure the exciton homogeneous linewidth. The 2D spectra also reveal an off-diagonal peak that oscillates as a function of the waiting time T. (C) 2014 Optical Society of America C1 [Sun, B.; Singh, R.; Cundiff, S. T.] NIST, JILA, Boulder, CO 80309 USA. [Sun, B.; Singh, R.; Cundiff, S. T.] Univ Colorado, Boulder, CO 80309 USA. [Singh, R.; Cundiff, S. T.] Univ Colorado, Dept Phys, Boulder, CO 80309 USA. [Padilha, L. A.] Univ Estadual Campinas, Inst Fis Gleb Wataghin, BR-13083970 Campinas, SP, Brazil. [Bae, W. K.] Korea Inst Sci & Technol, Photoelect Hybrid Res Ctr, Seoul 136791, South Korea. [Pietryga, J. M.; Klimov, V. I.] Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. RP Sun, B (reprint author), NIST, JILA, Boulder, CO 80309 USA.; Sun, B (reprint author), Univ Colorado, Boulder, CO 80309 USA. EM cundiff@jila.colorado.edu NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908601134 ER PT S AU Suratwala, T Steele, R Feit, M Dylla-Spears, R Desjardin, R Mason, D Wong, L Geraghty, P Miller, P Shen, N AF Suratwala, T. Steele, R. Feit, M. Dylla-Spears, R. Desjardin, R. Mason, D. Wong, L. Geraghty, P. Miller, P. Shen, N. GP IEEE TI Convergent Polishing: Simple, Low Cost Finishing Method of Glass Optics SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB A novel finishing process, called Convergent Polishing, is described where the workpiece regardless of its initial shape will converge to final surface figure under a fixed, unchanging set of polishing parameters in a single iteration. C1 [Suratwala, T.; Steele, R.; Feit, M.; Dylla-Spears, R.; Desjardin, R.; Mason, D.; Wong, L.; Geraghty, P.; Miller, P.; Shen, N.] Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA. RP Suratwala, T (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA. EM suratwalal@llnl.gov NR 0 TC 0 Z9 0 U1 3 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 1 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908601259 ER PT S AU Vanderhoef, LR Azad, AK Bomberger, CC Chowdhury, DR Chase, DB Taylor, AJ Zide, JMO Doty, MF AF Vanderhoef, Laura R. Azad, Abul K. Bomberger, Cory C. Chowdhury, Dibakar Roy Chase, D. Bruce Taylor, Antoinette J. Zide, Joshua M. O. Doty, Matthew F. GP IEEE TI Charge Carrier Relaxation Processes in TbAs Nanoinclusions in GaAs Measured By Optical-Pump THz-Probe Transient Absorption Spectroscopy SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB By analyzing how carrier relaxation rates depend on pump fluence and sample temperature, we conclude that states of TbAs embedded in GaAs are saturable. This suggests the existence of a bandgap for TbAs nanoparticles. C1 [Vanderhoef, Laura R.; Doty, Matthew F.] Univ Delaware, Dept Phys & Astron, Newark, DE 19716 USA. [Azad, Abul K.; Chowdhury, Dibakar Roy; Taylor, Antoinette J.] Los Alamos Natl Lab, Los Alamos, NM USA. [Bomberger, Cory C.; Chase, D. Bruce; Zide, Joshua M. O.; Doty, Matthew F.] Univ Delaware, Dept Mat Sci & Engn, Newark, DE 19716 USA. RP Vanderhoef, LR (reprint author), Univ Delaware, Dept Phys & Astron, Newark, DE 19716 USA. EM doty@udel.edu 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 SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600431 ER PT S AU Vasdekis, AE Grate, JW Konopka, AE Xantheas, SS Chang, TM AF Vasdekis, A. E. Grate, J. W. Konopka, A. E. Xantheas, S. S. Chang, T. -M. GP IEEE TI Simple Microfluidic Integration of 3D Optical Sensors Based on Solvent Immersion Lithography SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We will present Solvent Immersion Lithography (SIL) for microsystem prototyping in less than one minute. Our focus will primarily be on 3D optical sensor integration for biological applications in microfluidics and chemical microreactors. C1 [Vasdekis, A. E.; Grate, J. W.; Konopka, A. E.; Xantheas, S. S.] Pacific NW Natl Lab, Richland, WA 99354 USA. [Chang, T. -M.] Univ Wisconsin Parkside, Dept Chem, Kenosha, WI 53141 USA. RP Vasdekis, AE (reprint author), Pacific NW Natl Lab, Richland, WA 99354 USA. EM andreas.vasdekis@pnnl.gov NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908602175 ER PT S AU Wang, X Zgadzaj, R Fazel, N Li, L Henderson, W Chang, YY Korzekwa, R Yi, SA Ithudik, V Zhang, X Tsai, HE Pai, CH Quevedo, H Dyer, G Gaul, E Martinez, M Bernstein, A Borger, T Spinks, M Donovan, M Shvets, G Ditmire, T Downer, MC AF Wang, X. Zgadzaj, R. Fazel, N. Li, L. Henderson, W. Chang, Y. -Y. Korzekwa, R. Yi, S. A. Ithudik, V. Zhang, X. Tsai, H-E Pai, C. -H Quevedo, H. Dyer, G. Gaul, E. Martinez, M. Bernstein, A. Borger, T. Spinks, M. Donovan, M. Shvets, G. Ditmire, T. Downer, M. C. GP IEEE TI GeV Electrons and High brightness Betatron X-rays from Petawatt-Laser-Driven Plasma Accelerators SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We identify three regimes of correlated GeV-electron/keV-betatron-x-ray generation by a laser-plasma accelerator driven by the Texas Petawatt laser, and relate them to variations in strength of blowout, injection geometry and beam loading. (C) 2013 Optical Society of America C1 [Wang, X.; Zgadzaj, R.; Fazel, N.; Li, L.; Henderson, W.; Chang, Y. -Y.; Korzekwa, R.; Ithudik, V.; Zhang, X.; Tsai, H-E; Quevedo, H.; Dyer, G.; Gaul, E.; Martinez, M.; Bernstein, A.; Borger, T.; Spinks, M.; Donovan, M.; Shvets, G.; Ditmire, T.; Downer, M. C.] Univ Texas Austin, Dept Phys, Austin, TX 78712 USA. [Yi, S. A.] Los Alamos Natl Lab, Grp XCP6, Los Alamos, NM 87545 USA. [Pai, C. -H] Tsinghua Univ, Dept Engn Phys, Beijing 100084, Peoples R China. RP Wang, X (reprint author), Univ Texas Austin, Dept Phys, Austin, TX 78712 USA. EM downer@physics.utexas.edu NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600211 ER PT S AU Wierer, JJ Montano, I Crawford, MH Allerman, AA AF Wierer, J. J., Jr. Montano, I. Crawford, M. H. Allerman, A. A. GP IEEE TI Anisotropic optical polarization of AlGaN based 275 nm light-emitting diodes due to quantum-size effects SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB Quantum-size effects strongly influence the valance band and optical polarization of 275nm emitting Al0.44Ga0.56N layers. It's shown experimentally and theoretically that thinner quantum wells and lower carrier densities result in polarization preferential for light extraction. C1 [Wierer, J. J., Jr.; Montano, I.; Crawford, M. H.; Allerman, A. A.] Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RP Wierer, JJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM jwierer@sandia.gov NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908602184 ER PT S AU Wilcox, R Hartinger, K Holzwarth, R AF Wilcox, Russell Hartinger, Klaus Holzwarth, Ronald GP IEEE TI Sub-femtosecond Envelope Stability of Fiber Comb Lasers Locked to a CW Reference SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID PULSE TRAINS; SYNCHRONIZATION AB We measured relative envelope jitter of two fiber comb lasers, each with one comb line phase locked to a CW optical phase reference. Integrated jitter is 0.9fs RMS from 10Hz to 2MHz. C1 [Wilcox, Russell] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. [Hartinger, Klaus; Holzwarth, Ronald] Menlo Syst GmbH, Martinsried, Germany. RP Wilcox, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM rbwilcox@lbl.gov 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 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908603334 ER PT S AU Wilcox, R Doolittle, L Huang, G Fry, A AF Wilcox, Russell Doolittle, Lawrence Huang, Gang Fry, Alan GP IEEE TI Jitter Reduction in Digitally Synchronized Lasers SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We synchronize a modelocked Ti:sapphire laser to a 2.8GHz RF reference with 25fs jitter using an all-digital phase-locked loop, and a new technique for measuring the closed-loop transfer function and optimizing complex gain. C1 [Wilcox, Russell; Doolittle, Lawrence; Huang, Gang] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. [Fry, Alan] SLAC Natl Accelerator Lab, Linac Coherent Light Source, Menlo Pk, CA USA. RP Wilcox, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM rhwilcox@lbl.gov 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 SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908602096 ER PT S AU Williams, BP Humble, TS Grice, WP AF Williams, Brian P. Humble, Travis S. Grice, Warren P. GP IEEE TI Nonlocal polarization interferometer for entanglement detection SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We report an interferometer consisting of two spatially separated balanced Mach-Zehnder interferometers sharing a polarization entangled source. Nonlocal correlation statistics enable entanglement detection, Bell state identification, and fidelity bounding. (C) 2014 Optical Society of America C1 [Williams, Brian P.] Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. [Humble, Travis S.; Grice, Warren P.] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Williams, BP (reprint author), Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. EM bpwilliams@gmail.com; humblets@ornl.gov; gricew@ornl.gov NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908601418 ER PT S AU Wright, JB Campione, S Liu, S Martinez, JA Xu, HW Luk, TS Li, QM Wang, GT Swartzentruber, BS Brener, I AF Wright, Jeremy B. Campione, Salvatore Liu, Sheng Martinez, Julio A. Xu, Huiwen Luk, Ting S. Li, Qiming Wang, George T. Swartzentruber, Brian S. Brener, Igal GP IEEE TI Gallium Nitride Nanowire Distributed Feedback Lasers SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We have demonstrated single-mode lasing in a single gallium nitride nanowire using distributed feedback by external coupling to a dielectric grating. By adjusting the nanowire grating alignment we achieved a mode suppression ratio of 17dB. C1 [Wright, Jeremy B.; Campione, Salvatore; Liu, Sheng; Luk, Ting S.; Li, Qiming; Wang, George T.; Swartzentruber, Brian S.; Brener, Igal] Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. [Wright, Jeremy B.; Xu, Huiwen] Univ New Mexico, Ctr High Technol Mat, Albuquerque, NM 87111 USA. [Campione, Salvatore; Liu, Sheng; Martinez, Julio A.; Luk, Ting S.; Swartzentruber, Brian S.; Brener, Igal] Sandia Natl Labs, Ctr Integrated Nanotechnol, Albuquerque, NM 87123 USA. [Martinez, Julio A.] New Mexico State Univ, Dept Chem Engn, Las Cruces, NM 88003 USA. RP Wright, JB (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM jbwrigh@sandia.gov NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908602192 ER PT S AU Wu, CH Arju, N Fan, J Brener, I Shvets, G AF Wu, Chihhui Arju, Nihal Fan, Jonathan Brener, Igal Shvets, Gennady GP IEEE TI Spectrally Selective Chiral Silicon Metasurfaces Based on Infrared Fano Resonances SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB Silicon-process compatible metasurface was designed and tested in the infrared wavelength range. These metasurfaces show very high Q (>100), extreme chirality, and polarization conversion along with very low-loss operation. They show promise for sensing applications as well as spectrally selective CP thermal emitters. C1 [Wu, Chihhui; Arju, Nihal; Shvets, Gennady] Univ Texas Austin, Dept Phys, Austin, TX 78712 USA. [Brener, Igal] Sandia Natl Labs, Albuquerque, NM 87185 USA. [Brener, Igal] Sandia Natl Labs, Ctr Integrated Nanotechnol, Albuquerque, NM 87185 USA. [Fan, Jonathan] Univ Illinois, Beckman Inst, Urbana, IL 61801 USA. RP Wu, CH (reprint author), Univ Texas Austin, Dept Phys, Austin, TX 78712 USA. EM narju@ph.utexas.edu NR 4 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600183 ER PT S AU Yang, S Yin, XB Kante, B Zhang, P Zhu, J Wang, Y Zhang, X AF Yang, Sui Yin, Xiaobo Kante, Boubacar Zhang, Peng Zhu, Jia Wang, Yuan Zhang, Xiang GP IEEE TI Selective Self-assembly of Symmetry-breaking Nanoplasmonic Structures SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB Self-assembly approaches to construct plasmonic materials often result in high-symmetry structures within a thermodynamic limit. Here we demonstrate a novel selective self-assembly route for synthesis of a new class of nanoplasmonic structures with symmetry-breaking. C1 [Yang, Sui; Yin, Xiaobo; Kante, Boubacar; Zhang, Peng; Zhu, Jia; Wang, Yuan; Zhang, Xiang] Univ Calif Berkeley, NSF Nanoscale Sci & Engn Ctr NSEC, 3112 Etcheverry Hall, Berkeley, CA 94720 USA. [Yang, Sui; Yin, Xiaobo; Zhang, Xiang] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Yang, S (reprint author), Univ Calif Berkeley, NSF Nanoscale Sci & Engn Ctr NSEC, 3112 Etcheverry Hall, Berkeley, CA 94720 USA. EM suiyang@berkeley.edu RI Yin, Xiaobo/A-4142-2011; Yang, Sui /H-4417-2016 NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908601098 ER PT S AU Zhang, Q Arikawa, T Zudov, MA Reno, JL Pan, W Watson, JD Manfra, MJ Kono, J AF Zhang, Qi Arikawa, Takashi Zudov, Michael A. Reno, John L. Pan, Wei Watson, John D. Manfra, Michael J. Kono, Junichiro GP IEEE TI Superradiant Decay of Coherent Cyclotron Resonance in Ultrahigh-Mobility Two-Dimensional Electron Gases SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA AB We study the coherent dynamics of cyclotron resonance in ultrahigh-mobility two-dimensional electron gases via time-domain terahertz magneto-spectroscopy. We show that superradiant damping is the dominant decoherence mechanism at low temperatures. C1 [Zhang, Qi; Arikawa, Takashi; Kono, Junichiro] Rice Univ, Dept Elect & Comp Engn, POB 1892, Houston, TX 77251 USA. [Zudov, Michael A.] Univ Minnesota, Dept Phys, Minneapolis, MN 55455 USA. [Reno, John L.; Pan, Wei] Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. [Watson, John D.; Manfra, Michael J.] Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. RP Zhang, Q (reprint author), Rice Univ, Dept Elect & Comp Engn, POB 1892, Houston, TX 77251 USA. EM qi.zhang@rice.edu RI Watson, John/L-4296-2016 NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908600463 ER PT S AU Zhao, YF Liu, KY McClelland, JF Lu, M AF Zhao, Yunfei Liu, Kaiyang McClelland, John F. Lu, Meng GP IEEE TI Photonic Crystal Enhanced Photoacoustic Detection SO 2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) SE Conference on Lasers and Electro-Optics LA English DT Proceedings Paper CT Conference on Lasers and Electro-Optics (CLEO) CY JUN 08-13, 2014 CL San Jose, CA ID SPECTROSCOPY AB A photonic crystal sensor has been demonstrated to enhance photoacoustic signal from light absorbing molecules. The developed system was applied to detect an absorbing dye and gold nanoparticles and exhibited signal enhancement over 40 times. (C) 2014 Optical Society of America C1 [Zhao, Yunfei; Liu, Kaiyang; Lu, Meng] Iowa State Univ, Dept Elect & Comp Engn, Ames, IA 50011 USA. [McClelland, John F.] US DOE, Ames Lab, Ames, IA 50011 USA. [McClelland, John F.; Lu, Meng] Iowa State Univ, Dept Mech Engn, Ames, IA 50011 USA. [McClelland, John F.] Iowa State Univ, Dept Biochem Biophys & Mol Biol, Ames, IA 50011 USA. RP Lu, M (reprint author), Iowa State Univ, Dept Elect & Comp Engn, Ames, IA 50011 USA. EM menglu@iastate.edu NR 5 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2160-9020 J9 CONF LASER ELECTR PY 2014 PG 2 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA BE2RC UT WOS:000369908603309 ER PT J AU Michelogiannakis, G Shalf, J AF Michelogiannakis, George Shalf, John BE Bertozzi, D Benini, L Yalamanchili, S Henkel, J TI Variable-Width Datapath for On-Chip Network Static Power Reduction SO 2014 EIGHTH IEEE/ACM INTERNATIONAL SYMPOSIUM ON NETWORKS-ON-CHIP (NOCS) LA English DT Proceedings Paper CT Eighth IEEE/ACM International Symposium on Networks-on-Chip (NoCS) CY SEP 17-19, 2014 CL Ferrara, ITALY SP IEEE, IEEE Circuits & Syst Soc, IEEE Council Elect Design Automat, Acm, Sigda Acm, Acm SIGBED, ACM SIGRCH, Intel, Multitherman AB With the tight power budgets in modern largescale chips and the unpredictability of application traffic, onchip network designers are faced with the dilemma of designing for worst-case traffic loads and incurring high static power overheads, or designing for average traffic and risk degrading performance. This paper proposes adaptive bandwidth networks (ABNs) which divide channels and switches into lanes such that the network provides just the bandwidth necessary in each hop. ABNs also activate virtual channels (VCs) individually and take advantage of drowsy SRAM cells to eliminate false VC activations. In addition, ABNs readily tolerate silicon defects with just the extra cost of detection. For application benchmarks, ABNs reduce total power consumption by up to 45% with comparable performance compared to single-lane power-gated networks, and up to 33% compared to multi-network designs. C1 [Michelogiannakis, George; Shalf, John] Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RP Michelogiannakis, G (reprint author), Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM mihelog@lbl.gov; jshalf@lbl.gov NR 39 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5347-9 PY 2014 BP 96 EP 103 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA BF2MB UT WOS:000380479500015 ER PT J AU Gioiosa, R Kerbyson, DJ Hoisie, A AF Gioiosa, Roberto Kerbyson, Darren J. Hoisie, Adolfy GP ASME TI Evaluating Performance and Power Efficiency of Scientific Applications on Multi-threaded Systems SO 2014 ENERGY EFFICIENT SUPERCOMPUTING WORKSHOP (E2SC) LA English DT Proceedings Paper CT E2SC 2nd International Workshop on Energy Efficient Supercomputing CY NOV 16-21, 2014 CL New Orleans, LA SP ACM, IEEE Comp Soc, SIGHPC AB The power and energy walls are changing the way users utilize supercomputers: Time-to-completion is not the only important goal but other metrics, such as the energy required to solve a problem or the power efficiency, are becoming as important as performance. This shift towards power- and energy-aware computing is expected to continue in the exascale era, thus, understanding the performance, power and energy implications of different hardware configurations is of paramount importance. In this paper we analyze the performance, power efficiency and energy consumption of scientific applications programmed in MPI, OpenMP and MPI+OpenMP on two different architectures that have take different approaches to limit power consumption, IBM POWER7+ and AMD Interlagos. We compare the scalability, power efficiency and energy consumption of distributed and shared memory versions of each applications and analyze performance and bottlenecks of different combinations of MPI tasks/OpenMP threads. Our results show that, although shared memory programming models usually provide lower synchronization cost, achieving the highest performance/efficiency requires a combination for MPI tasks/ OpenMP threads that is dependent on the underlying architecture and takes into consideration how hardware resources are distributed among the computing elements. More importantly, our results show that the "best configuration" strongly depends on the particular target metric. C1 [Gioiosa, Roberto; Kerbyson, Darren J.; Hoisie, Adolfy] Pacific Northwest Natl Lab, High Performance Comp Grp, Richland, WA 99354 USA. RP Gioiosa, R (reprint author), Pacific Northwest Natl Lab, High Performance Comp Grp, Richland, WA 99354 USA. EM roberto.gioiosa@pnnl.gov; darren.kerbyson@pnnl.gov; adolfy.hoisie@pnnl.gov NR 21 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7036-0 PY 2014 BP 11 EP 20 DI 10.1109/E2SC.2014.15 PG 10 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2JM UT WOS:000380473100002 ER PT J AU Zhang, ZM Lang, M Pakin, S Fu, S AF Zhang, Ziming Lang, Michael Pakin, Scott Fu, Song GP ASME TI Trapped Capacity: Scheduling under a Power Cap to Maximize Machine-Room Throughput SO 2014 ENERGY EFFICIENT SUPERCOMPUTING WORKSHOP (E2SC) LA English DT Proceedings Paper CT E2SC 2nd International Workshop on Energy Efficient Supercomputing CY NOV 16-21, 2014 CL New Orleans, LA SP ACM, IEEE Comp Soc, SIGHPC AB Power-aware parallel job scheduling has been recognized as a demanding issue in the high-performance computing (HPC) community. The goal is to efficiently allocate and utilize power and energy in machine rooms. In practice the power for machine rooms is well over-provisioned, specified by high energy LINPACK runs or nameplate power estimates. This results in a considerable amount of trapped power capacity. Instead of being wasted, this trapped power capacity should be reclaimed to accommodate more compute nodes in the machine room and thereby increase system throughput. But to do this we need the ability to enforce a system-wide power cap. In this paper, we present TracSim, a full-system simulator that enables users to evaluate the performance of different policies for scheduling parallel tasks under a power cap. TracSim simulates the executing environment of an HPC cluster at Los Alamos National Laboratory (LANL). We use real measurements from the LANL cluster to set the configuration parameters of TracSim. TracSim enables users to specify the system topology, hardware configuration, power cap, and task workload, and to develop resource configuration and task scheduling policies aiming to maximize machine-room throughput while keeping power consumption under a power cap by exploiting CPU throttling techniques. We leverage TracSim to implement and evaluate three resource scheduling policies. Simulation results show the performance of those policies and quantify the amount of trapped capacity that can effectively be reclaimed. C1 [Zhang, Ziming; Fu, Song] Univ North Texas, Dept Comp Sci & Engn, Denton, TX 76203 USA. [Lang, Michael] Los Alamos Natl Lab, UltraScale Syst Res Ctr, Los Alamos, NM 87544 USA. [Pakin, Scott] Los Alamos Natl Lab, Appl Comp Sci Grp, Los Alamos, NM 87544 USA. RP Zhang, ZM (reprint author), Univ North Texas, Dept Comp Sci & Engn, Denton, TX 76203 USA. EM zimingzhang@my.unt.edu; mlang@lanl.gov; pakin@lanl.gov; song.fu@unt.edu OI Pakin, Scott/0000-0002-5220-1985 NR 29 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7036-0 PY 2014 BP 41 EP 50 DI 10.1109/E2SC.2014.10 PG 10 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2JM UT WOS:000380473100005 ER PT J AU Austin, B Wright, NJ AF Austin, Brian Wright, Nicholas J. GP ASME TI Measurement and interpretation of microbenchmark and application energy use on the Cray XC30 SO 2014 ENERGY EFFICIENT SUPERCOMPUTING WORKSHOP (E2SC) LA English DT Proceedings Paper CT E2SC 2nd International Workshop on Energy Efficient Supercomputing CY NOV 16-21, 2014 CL New Orleans, LA SP ACM, IEEE Comp Soc, SIGHPC DE Energy efficient computing; frequency scaling; energy model AB Understanding patterns of application energy use is key to reaching future HPC efficiency goals. We have measured the sensitivity of energy use to CPU frequency for several microbenchmarks and applications on a Cray XC30. We suggest first order models for performance and power vs. frequency and show that these are sufficient to accurately fit the measured energy data. Examination of the resulting energy model shows that an application's energy/frequency profiles have minima only if a) the frequency change crosses an architectural balance point that is performance-critical for the particular application or b) a significant fraction of the runtime is spent in off-chip operations or c) there is sufficient static power drawn to motivate a race-to-halt. All three forms of energy minima are represented in our sample of HPC applications. The energy-optimal frequencies on this architecture are: MILC (1.8 GHz), GTC (3.6 GHz) and Mini-DFT (1.6-1.8 GHz). C1 [Austin, Brian; Wright, Nicholas J.] Lawrence Berkeley Natl Lab, Natl Energy Res Sci Comp Ctr, Berkeley, CA 94720 USA. RP Austin, B (reprint author), Lawrence Berkeley Natl Lab, Natl Energy Res Sci Comp Ctr, Berkeley, CA 94720 USA. EM baustin@lbl.gov; njwright@lbl.gov NR 26 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7036-0 PY 2014 BP 51 EP 59 DI 10.1109/E2SC.2014.7 PG 9 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2JM UT WOS:000380473100006 ER PT J AU Barker, KJ Kerbyson, DJ Anger, E AF Barker, Kevin J. Kerbyson, Darren J. Anger, Eric GP ASME TI On the Feasibility of Dynamic Power Steering SO 2014 ENERGY EFFICIENT SUPERCOMPUTING WORKSHOP (E2SC) LA English DT Proceedings Paper CT E2SC 2nd International Workshop on Energy Efficient Supercomputing CY NOV 16-21, 2014 CL New Orleans, LA SP ACM, IEEE Comp Soc, SIGHPC DE Energy-efficient Computing; Large-scale Systems; Dynamic Power Steering; Dynamic Workloads AB While high performance has always been the primary constraint behind large-scale system design, future systems will be built with increasing energy efficiency in mind. Mechanisms such as fine-grained power scaling and gating will provide tools to system-software and application developers to ensure the most efficient use of tightly constrained power budgets. Such approaches to-date have been focused on node-level optimizations to impact overall system energy efficiency. In this work we introduce Dynamic Power Steering, in which power can be dynamically routed across a system to resources where it will be of most benefit and away from other resources to maintain a near-constant overall power budget. This, a higher-level algorithmic approach to improving energy efficiency, considers the whole extent of a system being used by an application. It can be used for applications in which there is load-imbalance that varies over its execution. Using two classes of applications, namely those that contain a wavefront type processing, and a particle-in-cell, we quantify the benefit of Dynamic Power Steering for a variety of workload characteristics and derive some insight into the ways in which workload behavior affect Power Steering applicability. C1 [Barker, Kevin J.; Kerbyson, Darren J.] Pacific Northwest Natl Lab, Performance & Architecture Lab, Richland, WA 99354 USA. [Anger, Eric] Georgia Inst Technol, Coll Comp, Atlanta, GA 30332 USA. RP Barker, KJ (reprint author), Pacific Northwest Natl Lab, Performance & Architecture Lab, Richland, WA 99354 USA. EM Kevin.Barker@pnnl.gov; Darren.Kerbyson@pnnl.gov; eanger@gatech.edu 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 978-1-4799-7036-0 PY 2014 BP 60 EP 69 DI 10.1109/E2SC.2014.6 PG 10 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2JM UT WOS:000380473100007 ER PT J AU Combs, J Nazor, J Thysell, R Santiago, F Hardwick, M Olson, L Rivoire, S Hsu, CH Poole, SW AF Combs, Jacob Nazor, Jolie Thysell, Rachelle Santiago, Fabian Hardwick, Matthew Olson, Lowell Rivoire, Suzanne Hsu, Chung-Hsing Poole, Stephen W. GP ASME TI Power Signatures of High-Performance Computing Workloads SO 2014 ENERGY EFFICIENT SUPERCOMPUTING WORKSHOP (E2SC) LA English DT Proceedings Paper CT E2SC 2nd International Workshop on Energy Efficient Supercomputing CY NOV 16-21, 2014 CL New Orleans, LA SP ACM, IEEE Comp Soc, SIGHPC ID TIME-SERIES; ALGORITHM; HPC AB Workload-aware power management and scheduling techniques have the potential to save energy while minimizing negative impact on performance. The effectiveness of these techniques depends on the stability of a workload's power consumption pattern across different input data, resource allocations (e.g. number of cores), and hardware platforms. In this paper, we show that the power consumption behavior of HPC workloads can be accurately captured by concise signatures built from their power traces. We validate this approach using 255 traces collected from 13 high-performance computing workloads on 4 different hardware platforms. First, we use both feature-based and time-series-based distance metrics to cluster our traces, and we quantitatively show that feature-based clusterings segregate traces by workload just as effectively as the more compute- and space-intensive time-series-based clusterings. Second, we demonstrate that unlabeled traces can be classified by workload with over 85% accuracy, based only on these concise statistical signatures. C1 [Combs, Jacob; Nazor, Jolie; Thysell, Rachelle; Santiago, Fabian; Hardwick, Matthew; Olson, Lowell; Rivoire, Suzanne] Sonoma State Univ, Dept Comp Sci, Rohnert Pk, CA 94928 USA. [Hsu, Chung-Hsing; Poole, Stephen W.] Oak Ridge Natl Lab, Oak Ridge, TN USA. RP Combs, J (reprint author), Sonoma State Univ, Dept Comp Sci, Rohnert Pk, CA 94928 USA. NR 41 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7036-0 PY 2014 BP 70 EP 78 DI 10.1109/E2SC.2014.9 PG 9 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2JM UT WOS:000380473100008 ER PT B AU Phillips, JC Stone, JE Vandivort, KL Armstrong, TG Wozniak, JM Wilde, M Schulten, K AF Phillips, James C. Stone, John E. Vandivort, Kirby L. Armstrong, Timothy G. Wozniak, Justin M. Wilde, Michael Schulten, Klaus GP IEEE TI Petascale Tcl with NAMD, VMD, and Swift/T SO 2014 FIRST WORKSHOP FOR HIGH PERFORMANCE TECHNICAL COMPUTING IN DYNAMIC LANGUAGES HPTCDL 2014 LA English DT Proceedings Paper CT 1st First Workshop High Performance Technical Computing Dynamic Languages Held CY NOV 17-17, 2014 CL new orleans, LA SP acm, ieee comp soc, sighpc DE Scripting; molecular simulation; molecular visualization; parallel rendering; CPU; many-core ID MOLECULAR-DYNAMICS; CRYOELECTRON MICROSCOPY; ALGORITHMS; SIMULATION AB Tcl is the original embeddable dynamic language. Introduced in 1990, Tel has been the foundation of the scripting interface of the popular biomolecular visualization and analysis program VMD since 1995 and was extended to the parallel molecular dynamics program NAMD in 1999. The two programs together have over 200,000 users who have enjoyed for nearly two decades the stability and flexibility provided by Tel. VMD users can implement or extend parallel trajectory analysis and movie rendering on thousands of nodes of Blue Waters. NAMD users can implement or extend simulation protocols and multiple-copy algorithms that execute unmodified on any supercomputer without the need to recompile NAMD. We now demonstrate the integration of the Swift/T high-performance parallel scripting language to enable high-level data flow programming in NAMD and VMD. This integration is achieved without modifying or re-compiling either program since the Turbine execution engine is itself based on Tel and is dynamically loaded by the interpreter, as is the platform-specific MPI library on which it depends. C1 [Phillips, James C.; Stone, John E.; Vandivort, Kirby L.] Univ Illinois, Beckman Inst, Urbana, IL 61801 USA. [Armstrong, Timothy G.] Univ Chicago, Dept Comp Sci, Chicago, IL 60637 USA. [Wozniak, Justin M.; Wilde, Michael] Argonne Natl Lab, Math & Comp Sci Div, Argonne, IL 60439 USA. [Schulten, Klaus] Univ Illinois, Dept Phys, Urbana, IL 61801 USA. RP Phillips, JC (reprint author), Univ Illinois, Beckman Inst, Urbana, IL 61801 USA. EM jim@ks.uiuc.edu; johns@ks.uiuc.edu; kvandivo@ks.uiuc.edu; tga@uchicago.edu; wozniak@mcs.anl.gov; wilde@anl.gov; kschulte@ks.uiuc.edu NR 42 TC 2 Z9 2 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7145-9; 978-1-4799-7020-9 PY 2014 BP 6 EP 17 DI 10.1109/HPTCDL.2014.7 PG 12 WC Computer Science, Software Engineering SC Computer Science GA BF2KT UT WOS:000380476300002 ER PT B AU Huchette, J Lubin, M Petra, C AF Huchette, Joey Lubin, Miles Petra, Cosmin GP IEEE TI Parallel algebraic modeling for stochastic optimization SO 2014 FIRST WORKSHOP FOR HIGH PERFORMANCE TECHNICAL COMPUTING IN DYNAMIC LANGUAGES HPTCDL 2014 LA English DT Proceedings Paper CT 1st First Workshop High Performance Technical Computing Dynamic Languages Held CY NOV 17-17, 2014 CL new orleans, LA SP acm, ieee comp soc, sighpc DE optimization; parallel programming; high performance computing; mathematical model; Power system modeling; scalability AB We present scalable algebraic modeling software, StochJuMP, for stochastic optimization as applied to power grid economic dispatch. It enables the user to express the problem in a high-level algebraic format with minimal boilerplate. StochJuMP allows efficient parallel model instantiation across nodes and efficient data localization. Computational results are presented showing that the model construction is efficient, requiring roughly one percent of solve time. StochJuMP is con figured with the parallel interior-point solver PIPS-IPM but is sufficiently generic to allow straight forward adaptation to other solvers. C1 [Huchette, Joey; Lubin, Miles] MIT, Ctr Operat Res, 77 Massachusetts Ave, Cambridge, MA 02139 USA. [Petra, Cosmin] Argonne Natl Lab, Math & Comp Sci Div, Argonne, IL 60439 USA. RP Huchette, J (reprint author), MIT, Ctr Operat Res, 77 Massachusetts Ave, Cambridge, MA 02139 USA. EM huchette@mit.edu; mlubin@mit.edu; petra@mcs.anl.gov NR 19 TC 4 Z9 4 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7145-9; 978-1-4799-7020-9 PY 2014 BP 29 EP 35 DI 10.1109/HPTCDL.2014.6 PG 7 WC Computer Science, Software Engineering SC Computer Science GA BF2KT UT WOS:000380476300004 ER PT J AU McCarthy, CM Isaacs, KE Bhatele, A Bremer, PT Hamann, B AF McCarthy, Collin M. Isaacs, Katherine E. Bhatele, Abhinav Bremer, Peer-Timo Hamann, Bernd GP IEEE TI Visualizing the Five-dimensional Torus Network of the IBM Blue Gene/Q SO 2014 First Workshop on Visual Performance Analysis (VPA) LA English DT Proceedings Paper CT 1st Workshop on Visual Performance Analysis (VPA) CY NOV 21, 2014 CL New Orleans, LA SP ACM, ACM SIGHPC, IEEE Comp Soc AB Understanding the interactions between a parallel application and the interconnection network over which it exchanges data is critical to optimizing performance in modern supercomputers. However, recent supercomputing architectures use networks that do not have natural low-dimensional representations, making them difficult to comprehend or visualize. In particular, high-dimensional torus networks are common and are used in four of the top ten supercomputers and eight of the top ten on the Graph500 list. We present a new visualization of five-dimensional torus networks. We use four connected views depicting the network at different levels of detail, allowing analysts to observe general large-scale traffic patterns while simultaneously viewing individual links or outliers in any specific section of the network. We demonstrate this approach by analyzing network traffic for a pF3D simulation running on the IBM Blue Gene/Q architecture, and show how it is both intuitive and effective for understanding and optimizing parallel application behavior. C1 [McCarthy, Collin M.; Isaacs, Katherine E.; Hamann, Bernd] Univ Calif Davis, Dept Comp Sci, Davis, CA 95616 USA. [Bhatele, Abhinav; Bremer, Peer-Timo] Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. RP McCarthy, CM (reprint author), Univ Calif Davis, Dept Comp Sci, Davis, CA 95616 USA. EM cmccarthy@ucdavis.edu; keisaacs@ucdavis.edu; bhamann@ucdavis.edu; bhatele@llnl.gov; ptbremer@llnl.gov NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7058-2 PY 2014 BP 24 EP 27 DI 10.1109/VPA.2014.10 PG 4 WC Computer Science, Theory & Methods SC Computer Science GA BG4XO UT WOS:000389247000004 ER PT J AU Wu, J Zeng, J Yu, H Kenny, JP AF Wu, Jieting Zeng, Jianping Yu, Hongfeng Kenny, Joseph P. GP IEEE TI CommGram: A New Visual Analytics Tool for Large Communication Trace Data SO 2014 FIRST WORKSHOP ON VISUAL PERFORMANCE ANALYSIS (VPA) LA English DT Proceedings Paper CT 1st Workshop on Visual Performance Analysis (VPA) CY NOV 21, 2014 CL New Orleans, LA SP ACM, ACM SIGHPC, IEEE Comp Soc ID PARALLEL; PERFORMANCE AB The performance of massively parallel program is often impacted by the cost of communication across computing nodes. Analysis of communication patterns is critical for understanding and optimizing massively parallel programs. Visualization can help identify potential communication bottlenecks by displaying message trace data. However, the visual clutter and temporal incoherence problems are typically incurred in existing visualization tools for a considerable number of processors. In this paper, we present a new tool, named CommGram, which supports visual analysis of communication patterns for massive parallel MPI programs. With the benefit of MPI trace library DUMPI of SST, our framework builds hierarchical clustering trees for computational community domain, and takes advantage of graphical user interface (GUI) to convey communication patterns at different levels of detail. The effectiveness of our tool is demonstrated using large-scale parallel applications. C1 [Wu, Jieting; Zeng, Jianping; Yu, Hongfeng] Univ Nebraska, Lincoln, NE 68588 USA. [Kenny, Joseph P.] Sandia Natl Labs, Livermore, CA USA. RP Wu, J (reprint author), Univ Nebraska, Lincoln, NE 68588 USA. EM jwu@cse.unl.edu; jizeng@cse.unl.edu; yu@cse.unl.edu; jpkenny@sandia.gov NR 33 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7058-2 PY 2014 BP 28 EP 35 DI 10.1109/VPA.2014.8 PG 8 WC Computer Science, Theory & Methods SC Computer Science GA BG4XO UT WOS:000389247000005 ER PT J AU Huck, KA Potter, K Jacobsen, DW Childs, H Malony, AD AF Huck, Kevin A. Potter, Kristin Jacobsen, Doug W. Childs, Hank Malony, Allen D. GP IEEE TI Linking Performance Data into Scientific Visualization Tools SO 2014 First Workshop on Visual Performance Analysis (VPA) LA English DT Proceedings Paper CT 1st Workshop on Visual Performance Analysis (VPA) CY NOV 21, 2014 CL New Orleans, LA SP ACM, ACM SIGHPC, IEEE Comp Soc AB Understanding the performance of program execution is essential when optimizing simulations run on high-performance supercomputers. Instrumenting and profiling codes is itself a difficult task and interpreting the resulting complex data is often facilitated through visualization of the gathered measures. However, these measures typically ignore spatial information specific to a simulation, which may contain useful knowledge on program behavior. Linking the instrumentation data to the visualization of performance within a spatial context is not straightforward as information needed to create the visualizations is not, by default, included in data collection, and the typical visualization approaches do not address spatial concerns. In this work, we present an approach that links the collection of spatially-aware performance data to a visualization paradigm through both analysis and visualization abstractions to facilitate better understanding of performance in the spatial context of the simulation. Because the potential costs for such a system are quite high, we leverage existing performance profiling and visualization systems and demonstrate their combined potential on climate simulation. C1 [Huck, Kevin A.; Potter, Kristin; Childs, Hank; Malony, Allen D.] Univ Oregon, Eugene, OR 97403 USA. [Jacobsen, Doug W.] Los Alamos Natl Lab, Los Alamos, NM USA. [Childs, Hank] Lawrence Berkeley Natl Lab, Berkeley, CA USA. RP Huck, KA (reprint author), Univ Oregon, Eugene, OR 97403 USA. EM khuck@cs.uoregon.edu; kpotter@cs.uoregon.edu; hank@cs.uoregon.edu; hchilds@lbl.gov; malony@cs.uoregon.edu NR 22 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7058-2 PY 2014 BP 50 EP 57 DI 10.1109/VPA.2014.9 PG 8 WC Computer Science, Theory & Methods SC Computer Science GA BG4XO UT WOS:000389247000008 ER PT J AU Chervenak, AL Sim, A Gu, JM Schuler, RE Hirpathak, N AF Chervenak, Ann L. Sim, Alex Gu, Junmin Schuler, Robert E. Hirpathak, Nandan GP IEEE TI Adaptation and Policy-Based Resource Allocation for Efficient Bulk Data Transfers in High Performance Computing Environments SO 2014 FOURTH INTERNATIONAL WORKSHOP ON NETWORK-AWARE DATA MANAGEMENT (NDM) LA English DT Proceedings Paper CT Fourth International Workshop on Network-Aware Data Management CY NOV 16-21, 2014 CL New Orleans, LA SP acm, IEEE Comp Soc, sighpc DE bulk data transfer; performance-based adaptation; policy-based resource allocation; resource constrained; throughput AB Many science applications increasingly make use of data-intensive methods that require bulk data movement such as staging of large datasets in preparation for analysis on shared computational resources, remote access to large data sets, and data dissemination. Over the next 5 to 10 years, these datasets are projected to grow to exabytes of data, and continued scientific progress will depend on efficient methods for data movement between high performance computing centers. We study two techniques that improve the use of available resources for large, long-running, multi-file transfers. First, we show the effect of adaptation of transfer parameters for multi-file transfers, where the adaptation is based on recent performance. Second, we use Virtual Organization and site policies to influence the allocation of resources such as available transfer streams to clients. We show that these techniques improve completion times for large multi-file data transfers by approximately 20% over resource constrained infrastructure. C1 [Chervenak, Ann L.; Schuler, Robert E.; Hirpathak, Nandan] Univ Southern Calif, Inst Informat Sci, Marina Del Rey, CA 90292 USA. [Sim, Alex; Gu, Junmin] Lawrence Berkeley Natl Lab, Sci Data Management Res Grp, Berkeley, CA USA. RP Chervenak, AL (reprint author), Univ Southern Calif, Inst Informat Sci, Marina Del Rey, CA 90292 USA. EM annc@isi.edu; asim@lbl.gov; jgu@lbl.gov; schuler@isi.edu; nandan@isi.edu NR 28 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7019-3 PY 2014 BP 1 EP 8 DI 10.1109/NDM.2014.7 PG 8 WC Computer Science, Theory & Methods SC Computer Science GA BF3FO UT WOS:000380536800001 ER PT J AU Hanford, N Ahuja, V Farrens, M Ghosal, D Balman, M Pouyoul, E Tierney, B AF Hanford, Nathan Ahuja, Vishal Farrens, Matthew Ghosal, Dipak Balman, Mehmet Pouyoul, Eric Tierney, Brian GP IEEE TI Analysis of the Effect of Core Affinity on High-Throughput Flows SO 2014 FOURTH INTERNATIONAL WORKSHOP ON NETWORK-AWARE DATA MANAGEMENT (NDM) LA English DT Proceedings Paper CT Fourth International Workshop on Network-Aware Data Management CY NOV 16-21, 2014 CL New Orleans, LA SP acm, IEEE Comp Soc, sighpc ID NETWORKS AB Network throughput is scaling-up to higher data rates while end-system processors are scaling-out to multiple cores. In order to optimize high speed data transfer into multicore end-systems, techniques such as network adapter offloads and performance tuning have received a great deal of attention. Furthermore, several methods of multithreading the network receive process have been proposed. However, thus far attention has been focused on how to set the tuning parameters and which offloads to select for higher performance, and little has been done to understand why the settings do (or do not) work. In this paper we build on previous research to track down the source(s) of the end-system bottleneck for high-speed TCP flows. For the purposes of this paper, we consider protocol processing efficiency to be the amount of system resources used (such as CPU and cache) per unit of achieved throughout (in Gbps). The amount of various system resources consumed are measured using low-level system event counters. Affinitization, or core binding, is the decision about which processor cores on an end system are responsible for interrupt, network, and application processing. We conclude that affinitization has a significant impact on protocol processing efficiency, and that the performance bottleneck of the network receive process changes drastically with three distinct affinitization scenarios. C1 [Hanford, Nathan; Ahuja, Vishal; Farrens, Matthew; Ghosal, Dipak] Univ Calif Davis, Dept Comp Sci, Davis, CA 95616 USA. [Balman, Mehmet; Pouyoul, Eric; Tierney, Brian] Lawrence Berkeley Natl Lab, Energy Sci Network, Berkeley, CA USA. RP Hanford, N (reprint author), Univ Calif Davis, Dept Comp Sci, Davis, CA 95616 USA. EM nhanford@ucdavis.edu; vahuja@ucdavis.edu; mkfarrens@ucdavis.edu; dghosal@ucdavis.edu; mbalman@lbl.gov; lomax@es.net; bltierney@es.net OI Hanford, Nathan/0000-0002-2214-7447 NR 35 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7019-3 PY 2014 BP 9 EP 15 DI 10.1109/NDM.2014.10 PG 7 WC Computer Science, Theory & Methods SC Computer Science GA BF3FO UT WOS:000380536800002 ER PT S AU Wozniak, JM Wilde, M Foster, IT AF Wozniak, Justin M. Wilde, Michael Foster, Ian T. GP IEEE TI Language Features for Scalable Distributed-Memory Dataflow Computing SO 2014 Fourth Workshop on Data-Flow Execution Models for Extreme Scale Computing DFM 2014 SE Workshop on Data-Flow Execution Models for Extreme Scale Computing LA English DT Proceedings Paper CT Fourth Workshop on Data-Flow Execution Models for Extreme Scale Computing DFM 2014 CY AUG 24-24, 2014 CL Edmonton, CANADA SP CPS, IEEE Comp Soc AB Dataflow languages offer a natural means to express concurrency but are not a natural representation of the architectural features of high-performance, distributed-memory computers. When used as the outermost language in a hierarchical programming model, dataflow is very effective at expressing the overall flow of a computation. In this work, we present strategies and techniques used by the Swift dataflow language to obtain good performance on extremely large computing systems. We also present multiple unique language features that offer practical utility and performance enhancements. C1 [Wozniak, Justin M.; Wilde, Michael; Foster, Ian T.] Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. [Wozniak, Justin M.; Wilde, Michael; Foster, Ian T.] Univ Chicago, Computat Inst, Chicago, IL 60637 USA. [Wozniak, Justin M.; Wilde, Michael; Foster, Ian T.] Argonne Natl Lab, Chicago, IL USA. [Foster, Ian T.] Univ Chicago, Dept Comp Sci, Chicago, IL 60637 USA. RP Wozniak, JM (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2325-5579 BN 978-1-4799-8095-6 J9 WORKS DATA EXEC PY 2014 BP 50 EP 53 DI 10.1109/DFM.2014.17 PG 4 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BF3LO UT WOS:000380554400008 ER PT B AU Tramm, JR Yoshii, K Siegel, AR AF Tramm, John R. Yoshii, Kazutomo Siegel, Andrew R. GP IEEE TI Power Profiling of a Reduced Data Movement Algorithm for Neutron Cross Section Data in Monte Carlo Simulations SO 2014 HARDWARE-SOFTWARE CO-DESIGN FOR HIGH PERFORMANCE COMPUTING (CO-HPC) LA English DT Proceedings Paper CT 1st International Workshop on Hardware-Software Co-Design for High Performance Computing (Co-HPC) CY NOV 16-21, 2014 CL New Orleans, LA SP ACM, IEEE Comp Soc, Sighpc ID TRANSPORT CODE AB Current Monte Carlo neutron transport applications use continuous energy cross section data to provide the statistical foundation for particle trajectories. This "classical" algorithm requires storage and random access of very large data structures. Recently, Forget et al.[1] reported on a fundamentally new approach, based on multipole expansions, that distills cross section data down to a more abstract mathematical format. Their formulation greatly reduces memory storage and improves data locality at the cost of also increasing floating point computation. In the present study we determine the hardware performance parameters, including power usage, of the multipole algorithm relative to the classical continuous energy algorithm. This study is done to guage the suitability of both algorithms for use on next-generation high performance computing platforms. C1 [Tramm, John R.; Yoshii, Kazutomo; Siegel, Andrew R.] Argonne Natl Lab, Div Math & Comp Sci, CESAR, Argonne, IL 60439 USA. RP Tramm, JR (reprint author), Argonne Natl Lab, Div Math & Comp Sci, CESAR, Argonne, IL 60439 USA. EM jtramm@mcs.anl.gov; kazutomo@mcs.anl.gov; siegela@mcs.anl.gov OI Tramm, John/0000-0002-5397-4402 NR 18 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7564-8 PY 2014 BP 17 EP 24 DI 10.1109/Co-HPC.2014.9 PG 8 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BF2CP UT WOS:000380455900003 ER PT B AU Ang, JA Barrett, RF Benner, RE Burke, D Chan, C Cook, J Donofrio, D Hammond, SD Hemmert, KS Kelly, SM Le, H Leung, VJ Resnick, DR Rodrigues, AF Shalf, J Stark, D Unat, D Wright, NJ AF Ang, J. A. Barrett, R. F. Benner, R. E. Burke, D. Chan, C. Cook, J. Donofrio, D. Hammond, S. D. Hemmert, K. S. Kelly, S. M. Le, H. Leung, V. J. Resnick, D. R. Rodrigues, A. F. Shalf, J. Stark, D. Unat, D. Wright, N. J. GP IEEE TI Abstract Machine Models and Proxy Architectures for Exascale Computing SO 2014 HARDWARE-SOFTWARE CO-DESIGN FOR HIGH PERFORMANCE COMPUTING (CO-HPC) LA English DT Proceedings Paper CT 1st International Workshop on Hardware-Software Co-Design for High Performance Computing (Co-HPC) CY NOV 16-21, 2014 CL New Orleans, LA SP ACM, IEEE Comp Soc, Sighpc AB To achieve exascale computing, fundamental hardware architectures must change. This will significantly impact scientific applications that run on current high performance computing (HPC) systems, many of which codify years of scientific domain knowledge and refinements for contemporary computer systems. To adapt to exascale architectures, developers must be able to reason about new hardware and determine what programming models and algorithms will provide the best blend of performance and energy efficiency in the future. An abstract machine model is designed to expose to the application developers and system software only the aspects of the machine that are important or relevant to performance and code structure. These models are intended as communication aids between application developers and hardware architects during the co-design process. A proxy architecture is a parameterized version of an abstract machine model, with parameters added to elucidate potential speeds and capacities of key hardware components. These more detailed architectural models enable discussion among the developers of analytic models and simulators and computer hardware architects and they allow for application performance analysis, system software development, and hardware optimization opportunities. In this paper, we present a set of abstract machine models and show how they might be used to help software developers prepare for exascale. We then apply parameters to one of these models to demonstrate how a proxy architecture can enable a more concrete exploration of how well application codes map onto future architectures. C1 [Ang, J. A.; Barrett, R. F.; Benner, R. E.; Cook, J.; Hammond, S. D.; Hemmert, K. S.; Kelly, S. M.; Le, H.; Leung, V. J.; Resnick, D. R.; Rodrigues, A. F.; Stark, D.] Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. [Burke, D.; Chan, C.; Donofrio, D.; Shalf, J.; Unat, D.] Lawrence Berkeley Natl Lab, Berkeley, CA USA. RP Ang, JA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 20 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7564-8 PY 2014 BP 25 EP 32 DI 10.1109/Co-HPC.2014.4 PG 8 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BF2CP UT WOS:000380455900004 ER PT B AU Woodward, PR Jayaraj, J Barrett, R AF Woodward, Paul R. Jayaraj, Jagan Barrett, Richard GP IEEE TI mPPM, Viewed as a Co-Design Effort SO 2014 HARDWARE-SOFTWARE CO-DESIGN FOR HIGH PERFORMANCE COMPUTING (CO-HPC) LA English DT Proceedings Paper CT 1st International Workshop on Hardware-Software Co-Design for High Performance Computing (Co-HPC) CY NOV 16-21, 2014 CL New Orleans, LA SP ACM, IEEE Comp Soc, Sighpc DE co-design; miniapp; memory bandwidth ID CONSERVATIVE DIFFERENCE SCHEME; FLOW AB The Piecewise Parabolic Method (PPM) was designed as a means of exploring compressible gas dynamics problems of interest in astrophysics, including supersonic jets, compressible turbulence, stellar convection, and turbulent mixing and burning of gases in stellar interiors. Over time, the capabilities encapsulated in PPM have coevolved with the availability of a series of high performance computing platforms. Implementation of the algorithm has adapted to and advanced with the architectural capabilities and characteristics of these machines. This adaptability of our PPM codes has enabled targeted astrophysical applications of PPM to exploit these scarce resources to explore complex physical phenomena. Here we describe the means by which this was accomplished, and set a path forward, with a new miniapp, mPPM, for continuing this process in a diverse and dynamic architecture design environment. Adaptations in mPPM for the latest high performance machines are discussed that address the important issue of limited bandwidth from locally attached main memory to the microprocessor chip. C1 [Woodward, Paul R.] Univ Minnesota, Lab Computat Sci & Engn, Minneapolis, MN USA. [Jayaraj, Jagan; Barrett, Richard] Sandia Natl Labs, Comp Sci Res Inst, Albuquerque, NM 87185 USA. RP Woodward, PR (reprint author), Univ Minnesota, Lab Computat Sci & Engn, Minneapolis, MN USA. EM paul@lcse.umn.edu; jnjayar@sandia.gov; rfbarre@sandia.gov NR 22 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7564-8 PY 2014 BP 33 EP 40 DI 10.1109/Co-HPC.2014.13 PG 8 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BF2CP UT WOS:000380455900005 ER PT B AU Cicotti, P Mniszewski, SM Carrington, L AF Cicotti, Pietro Mniszewski, Susan M. Carrington, Laura GP IEEE TI An Evaluation of Threaded Models for a Classical MD Proxy Application SO 2014 HARDWARE-SOFTWARE CO-DESIGN FOR HIGH PERFORMANCE COMPUTING (CO-HPC) LA English DT Proceedings Paper CT 1st International Workshop on Hardware-Software Co-Design for High Performance Computing (Co-HPC) CY NOV 16-21, 2014 CL New Orleans, LA SP ACM, IEEE Comp Soc, Sighpc DE computer architecture; parallel processing; parallel programming; performance analysis; parallel algorithms; multithreading AB Exascale systems will have many-core nodes, less memory capacity per core than today's systems, and a large degree of performance variability between cores. All these conditions challenge bulk synchronous SPMD models in which execution is typically synchronous and communication is based on buffers and ghost regions. We explore the design of a multithreaded MD code to evaluate several tradeoffs that arise when converting an MPI application into a hybrid multithreaded application, to address the aforementioned constraints of future architectures. Using OpenMP and PThreads, we implemented several variants of CoMD, a molecular dynamics proxy application. We found that in CoMD, duplicating some of the work to avoid race conditions is an easier and more scalable solution than using atomic updates; that data allocation and placement can be controlled to some extent with a hybrid MPI+threads approach, though an explicit NUMA API to control locality may be desirable; and finally that dynamically scheduling the work within a process can mitigate the impact of performance variability among cores and preserve most of the performance, especially when compared to bulk synchronous implementations such as the MPI reference. C1 [Cicotti, Pietro; Carrington, Laura] Univ Calif San Diego, San Diego Supercomp Ctr, San Diego, CA 92103 USA. [Mniszewski, Susan M.] Los Alamos Natl Lab, Los Alamos, NM USA. RP Cicotti, P (reprint author), Univ Calif San Diego, San Diego Supercomp Ctr, San Diego, CA 92103 USA. EM pcicotti@sdsc.edu; smm@lanl.gov; lcarring@sdsc.edu OI Mniszewski, Susan/0000-0002-0077-0537 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 978-1-4799-7564-8 PY 2014 BP 41 EP 48 DI 10.1109/Co-HPC.2014.6 PG 8 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BF2CP UT WOS:000380455900006 ER PT B AU Sreepathi, S Grodowitz, ML Lim, R Taffet, P Roth, PC Meredith, J Lee, S Li, D Vetter, J AF Sreepathi, Sarat Grodowitz, M. L. Lim, Robert Taffet, Philip Roth, Philip C. Meredith, Jeremy Lee, Seyong Li, Dong Vetter, Jeffrey GP IEEE TI Application Characterization using Oxbow Toolkit and PADS Infrastructure SO 2014 HARDWARE-SOFTWARE CO-DESIGN FOR HIGH PERFORMANCE COMPUTING (CO-HPC) LA English DT Proceedings Paper CT 1st International Workshop on Hardware-Software Co-Design for High Performance Computing (Co-HPC) CY NOV 16-21, 2014 CL New Orleans, LA SP ACM, IEEE Comp Soc, Sighpc AB Characterizing the behavior of a scientific application and its associated proxy application is essential for determining whether the proxy application actually does mimic the full application. To support our ongoing characterization activities, we have developed the Oxbow toolkit and an associated data store infrastructure for collecting, storing, and querying this characterization information. This paper presents recent updates to the Oxbow toolkit and introduces the Oxbow project's Performance Analytics Data Store (PADS). To demonstrate the possible insights when using the toolkit and data store, we compare the characterizations of several full and proxy applications, along with the High Performance Linpack (HPL) and High Performance Conjugate Gradient (HPCG) benchmarks. Using techniques such as cluster visualizations of PADS data across many experiments, we found that the results show unexpected similarities and differences between proxy applications, and a greater similarity of proxy applications to HPCG than to HPL along many dimensions. C1 [Sreepathi, Sarat; Grodowitz, M. L.; Roth, Philip C.; Meredith, Jeremy; Lee, Seyong; Li, Dong; Vetter, Jeffrey] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. [Lim, Robert] Univ Oregon, Eugene, OR 97403 USA. [Taffet, Philip] Rice Univ, Houston, TX USA. RP Sreepathi, S (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM sarat@ornl.gov; grodowitzml@ornl.gov; roblim1@cs.uoregon.edu; ptaffet@rice.edu; rothpc@ornl.gov; jsmeredith@ornl.gov; lees2@ornl.gov; lid1@ornl.gov; vetter@ornl.gov OI Sreepathi, Sarat/0000-0002-4978-9423 NR 18 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7564-8 PY 2014 BP 55 EP 63 DI 10.1109/Co-HPC.2014.11 PG 9 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BF2CP UT WOS:000380455900008 ER PT B AU Stelle, G Olivier, SL Stark, D Rodrigues, AF Hemmert, KS AF Stelle, George Olivier, Stephen L. Stark, Dylan Rodrigues, Arun F. Hemmert, K. Scott GP IEEE TI Using a Complementary Emulation-Simulation Co-Design Approach to Assess Application Readiness for Processing-in-Memory Systems SO 2014 HARDWARE-SOFTWARE CO-DESIGN FOR HIGH PERFORMANCE COMPUTING (CO-HPC) LA English DT Proceedings Paper CT 1st International Workshop on Hardware-Software Co-Design for High Performance Computing (Co-HPC) CY NOV 16-21, 2014 CL New Orleans, LA SP ACM, IEEE Comp Soc, Sighpc AB Disruptive changes to computer architecture are paving the way toward extreme scale computing. The co-design strategy of collaborative research and development among computer architects, system software designers, and application teams can help to ensure that applications not only cope but thrive with these changes. In this paper, we present a novel combined co-design approach of emulation and simulation in the context of investigating future Processing in Memory (PIM) architectures. PIM enables co-location of data and computation to decrease data movement, to provide increases in memory speed and capacity compared to existing technologies and, perhaps most importantly for extreme scale, to improve energy efficiency. Our evaluation of PIM focuses on three mini-applications representing important production applications. The emulation and simulation studies examine the effects of locality-aware versus locality-oblivious data distribution and computation, and they compare PIM to conventional architectures. Both studies contribute in their own way to the overall understanding of the application-architecture interactions, and our results suggest that PIM technology shows great potential for efficient computation without negatively impacting productivity. C1 [Stelle, George] Univ New Mexico, Dept Comp Sci, Albuquerque, NM 87131 USA. [Olivier, Stephen L.; Stark, Dylan; Rodrigues, Arun F.; Hemmert, K. Scott] Sandia Natl Labs, Dept 1423, Ctr Res Comp, Albuquerque, NM 87185 USA. [Olivier, Stephen L.; Stark, Dylan; Rodrigues, Arun F.; Hemmert, K. Scott] Sandia Natl Labs, Dept 1422, Ctr Res Comp, Albuquerque, NM 87185 USA. RP Stelle, G (reprint author), Univ New Mexico, Dept Comp Sci, Albuquerque, NM 87131 USA. EM stelleg@cs.unm.edu; slolivi@sandia.gov; dstark@sandia.gov; afrodri@sandia.gov; kshemme@sandia.gov NR 17 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7564-8 PY 2014 BP 64 EP 71 DI 10.1109/Co-HPC.2014.5 PG 8 WC Computer Science, Hardware & Architecture; Computer Science, Theory & Methods SC Computer Science GA BF2CP UT WOS:000380455900009 ER PT J AU Jenkins, C Pierson, L AF Jenkins, Chris Pierson, Lyndon GP IEEE TI Integrity Levels A New Paradigm for Protecting Computing Systems SO 2014 IEEE 13th International Conference on Trust, Security and Privacy in Computing and Communications (TrustCom) LA English DT Proceedings Paper CT 13th IEEE International Conference on Trust Security and Privacy in Computing and Communications (TrustCom) CY SEP 24-26, 2014 CL Beijing, PEOPLES R CHINA SP IEEE, IEEE Comp Soc, IEEE Tech Comm Scalable Comp, Tsinghua Univ, NSFC, Comp Sci Org, Huawei, Tsinghua Univ, Sch Software DE virtualization; trusted computing; computer security policy; hypervisor; operating system; computer architecture AB As the field of determined and increasingly sophisticated adversaries multiplies, the risk to integrity of deployed computing devices magnifies. Given the ubiquitous connectivity, substantial storage, and accessibility, the increased reliance on computer platforms make them a significant target for attackers. Over the past decade, malware has transitioned from attacking a single program to subverting the operating system (OS) kernel by means of what is commonly known as a rootkit. While computer systems require patches to fix newly discovered vulnerabilities, undiscovered vulnerabilities remain. Furthermore, typical solutions utilize mechanisms that operate within the OS. If the OS becomes compromised, these mechanisms may be vulnerable to being disabled or upon detection of the potential compromise, being "shut down" until patched, or otherwise mitigated. We propose an innovative approach to designing computer systems that allows the behavior or functionality of the computer system to change based on the integrity of the system. Instead of attempting to prevent or detect all malware attacks, our proposed approach allows possible graceful degradation of functionality according to the security policy specification as anomalies of security concern are detected. We believe this innovative paradigm can determine the "integrity level" of the system. Based on the integrity level, the computer system may behave differently or limit access to data. C1 [Jenkins, Chris; Pierson, Lyndon] Sandia Natl Labs, Assurance Tech & Assessments, POB 5800, Albuquerque, NM 87185 USA. RP Jenkins, C (reprint author), Sandia Natl Labs, Assurance Tech & Assessments, POB 5800, Albuquerque, NM 87185 USA. EM cdjenk@sandia.gov; lgpiers@sandia.gov NR 29 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-6513-7 PY 2014 BP 534 EP 543 DI 10.1109/TrustCom.2014.68 PG 10 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BF3OO UT WOS:000380562600066 ER PT J AU Kang, K Kang, Y Sul, S AF Kang, KyungWoo Kang, Yunhee Sul, SungJin GP IEEE TI The Evaluation of Emulab as an Environment for Bio-informatics Research SO 2014 IEEE 13th International Conference on Trust, Security and Privacy in Computing and Communications (TrustCom) LA English DT Proceedings Paper CT 13th IEEE International Conference on Trust Security and Privacy in Computing and Communications (TrustCom) CY SEP 24-26, 2014 CL Beijing, PEOPLES R CHINA SP IEEE, IEEE Comp Soc, IEEE Tech Comm Scalable Comp, Tsinghua Univ, NSFC, Comp Sci Org, Huawei, Tsinghua Univ, Sch Software DE Emulab; BLAST; mr-mpi; MapReduce ID TOOL AB Emulab is an emulation-based network test-bed constructed for research and education. It is used for building and testing applications in fields of information security and computer network. The application of Emulab is being extended to parallel processing of scientific data. The DNA sequence search is one of major research areas in the bio-informatics. With the high-performance computing, the biologists can get their results easily and faster. mpiBLAST and mr-mpi-blast can process DNA sequence alignment on parallel computer. In this research, the research environments for mpiBLAST and mr-mpi-blast are built on Emulab. Also, the DNA sequence alignment is performed with NCBI database. This research shows that the Emulab is an effective environment for the research of the bio-informatics. C1 [Kang, KyungWoo; Kang, Yunhee] Baekseok Univ, Informat & Commun Div, Cheonan, South Korea. [Sul, SungJin] Lawrence Berkeley Natl Lab, Berkeley, CA USA. RP Kang, K (reprint author), Baekseok Univ, Informat & Commun Div, Cheonan, South Korea. EM yhkang@bu.ac.kr; kwkang@bu.ac.kr; ssul@lbl.gov NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-6513-7 PY 2014 BP 714 EP 720 DI 10.1109/TrustCom.2014.93 PG 7 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BF3OO UT WOS:000380562600090 ER PT J AU Dutta, I Liu, J Mireles, K Kumar, P Meinshausen, L AF Dutta, I. Liu, J. Mireles, K. Kumar, P. Meinshausen, L. GP IEEE TI Interfacially Engineered Micro and Nano-Scale Cu-In Composites as High Performance Thermal Interface Materials for Advanced Electronics SO 2014 IEEE 16TH ELECTRONICS PACKAGING TECHNOLOGY CONFERENCE (EPTC) LA English DT Proceedings Paper CT IEEE 16th Electronics Packaging Technology Conference (EPTC) CY DEC 03-05, 2014 CL Marina Bay Sands, SINGAPORE SP IEEE, CPMT ID ATOMIC LAYER DEPOSITION; LIQUID INDIUM; COPPER; CONDUCTIVITY; ENHANCEMENT AB A key enabler of modern information and communications technologies (ICT) is energy-efficient electronics. As electronics become increasingly powerful and vertically integrated into 3-D structures, new design paradigms are needed to efficiently dissipate thermal energy produced by Joule heating, to minimize the need for active, power-hungry cooling schemes. This necessitates the development of new thermal interface materials (TIMs) with high thermal conductivity (k), low reflow temperature, and high shear compliance. This paper reports on two novel Cu-In composite TIMs: (i) a micro-composite with spherical copper particles in In matrix, produced via powder processing; and (ii) a nano-composite comprising aligned copper nanowires in In matrix, produced by templated electrodeposition. The material architectures, fabrication routes, resultant thermal properties, and potential means to improve the properties further are discussed. C1 [Dutta, I.; Mireles, K.; Meinshausen, L.] Washington State Univ, Sch Mech & Mat Engn, Pullman, WA 99164 USA. [Liu, J.] Pacific Northwest Natl Lab, Environm & Mol Sci Lab, Richland, WA 99352 USA. [Kumar, P.] Indian Inst Sci, Dept Mat Engn, Bangalore 560012, Karnataka, India. RP Dutta, I (reprint author), Washington State Univ, Sch Mech & Mat Engn, Pullman, WA 99164 USA. NR 19 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-6994-4 PY 2014 BP 635 EP 640 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BF2QS UT WOS:000380491200160 ER PT J AU Lu, HW Tan, GM Chen, MY Sun, NH AF Lu, Huiwei Tan, Guangming Chen, Mingyu Sun, Ninghui BE Liu, X ElBaz, D Hsu, CH Kang, K Chen, W TI Reducing Communication in Parallel Breadth-First Search on Distributed Memory Systems SO 2014 IEEE 17th International Conference on Computational Science and Engineering (CSE) LA English DT Proceedings Paper CT IEEE 17th International Conference on Computational Science and Engineering (CSE) CY DEC 19-21, 2014 CL Chengdu, PEOPLES R CHINA SP IEEE, IEEE comp soc, IEEE TCSC, NSFC, UeSTC, StFX Univ, Ubiquitous Media Commun Lab ID COLLECTIVE OPERATIONS; ALGORITHM; PERFORMANCE; COMPRESSION; PROCESSOR AB Breadth-first search (BFS) is a key operation in data-intensive graph analysis applications. However, for distributed BFS algorithm on large distributed memory systems, data communication often limits the scalability of the algorithm as it costs significantly more than arithmetic computation. In this work, we try to reduce the communication cost in distributed BFS by sieving and compressing the messages. First, we propose a novel distributed directory to sieve the redundant data in collective communications. Then we leverage a bitmap compression algorithm to further reduce the size of messages in communication. Experiments on a 6,144-core Intel Westmere based cluster show our algorithm achieve a BFS performance rate of 12.1 billion edge visits per second on an undirected graph of 8 billion vertices and 128 billion edges with scale-free distribution. Compared to the "replicated-csr" version BFS in Graph500, our algorithm reduces communication cost by 79.0% and gets a speedup of 2.2x. C1 [Lu, Huiwei; Tan, Guangming; Chen, Mingyu; Sun, Ninghui] Chinese Acad Sci, State Key Lab Comp Architecture, Inst Comp Technol, Beijing 100864, Peoples R China. [Lu, Huiwei] Argonne Natl Lab, Argonne, IL 60439 USA. RP Lu, HW (reprint author), Chinese Acad Sci, State Key Lab Comp Architecture, Inst Comp Technol, Beijing 100864, Peoples R China. EM huiweilu@mcs.anl.gov; tgm@ict.ac.cn; cmy@ict.ac.cn; snh@ncic.ac.cn NR 27 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7981-3 PY 2014 BP 1261 EP 1268 DI 10.1109/CSE.2014.243 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA BF2ZC UT WOS:000380512100208 ER PT S AU Duan, SS Levitt, K Hein, ML Peisert, S Zhang, HB AF Duan, Sisi Levitt, Karl Hein Meling Peisert, Sean Zhang, Haibin GP IEEE TI ByzID: Byzantine Fault Tolerance from Intrusion Detection SO 2014 IEEE 33RD INTERNATIONAL SYMPOSIUM ON RELIABLE DISTRIBUTED SYSTEMS (SRDS) SE Symposium on Reliable Distributed Systems Proceedings LA English DT Proceedings Paper CT IEEE 33rd International Symposium on Reliable Distributed Systems CY OCT 06-09, 2014 CL Nara, JAPAN SP IEEE Comp Soc, Recruit Technologies Co Ltd, HITACHI Ltd, Database Soc Japan, YAHOO JAPAN, TOSHIBA Corp, Patinum Sponsor, Conf Publishing Serv ID CONSENSUS; TIME; SYSTEM AB Building robust network services that can withstand a wide range of failure types is a fundamental problem in distributed systems. The most general approach, called Byzantine fault tolerance, can mask arbitrary failures. Yet it is often considered too costly to deploy in practice, and many solutions are not resilient to performance attacks. To address this concern we leverage two key technologies already widely deployed in cloud computing infrastructures: replicated state machines and intrusion detection systems. First, we have designed a general framework for constructing Byzantine failure detectors based on an intrusion detection system. Based on such a failure detector, we have designed and built a practical Byzantine fault-tolerant protocol, which has costs comparable to crash-resilient protocols like Paxos. More importantly, our protocol is particularly robust against several key attacks such as flooding attacks, timing attacks, and fairness attacks, that are typically not handled well by Byzantine fault masking procedures. C1 [Duan, Sisi; Levitt, Karl; Peisert, Sean; Zhang, Haibin] Univ Calif Davis, Davis, CA 95616 USA. [Hein Meling] Univ Stavanger, Stavanger, Norway. [Peisert, Sean] LBNL, Berkeley, CA USA. RP Duan, SS (reprint author), Univ Calif Davis, Davis, CA 95616 USA. EM sduan@ucdavis.edu; levitt@ucdavis.edu; hein.meling@uis.no; speisert@ucdavis.edu; hbzhang@ucdavis.edu NR 38 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 1060-9857 BN 978-1-4799-5584-8 J9 SYM REL DIST SYST PY 2014 BP 253 EP 264 DI 10.1109/SRDS.2014.28 PG 12 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF1WA UT WOS:000380439400027 ER PT J AU Bartholomy, O Vargas, T Simone, M Hansen, C Fitchett, S Pohl, A AF Bartholomy, Obadiah Vargas, Thomas Simone, Megan Hansen, Cliff Fitchett, Stephanie Pohl, Andrew GP IEEE TI Benchmarking Solar Power and Irradiance Forecasting Accuracy at Sacramento Municipal Utility District SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE distributed generation modeling; solar resource assessment; solar forecasting; resource spatial diversity; variability; ramping; solar operations integration AB The Sacramento Municipal Utility District has been working with several commercial forecasters to evaluate the performance of their forecasts in predicting PV output. The work leverages SMUD's network of 74 irradiance monitoring sites that were installed and are maintained by NEO Virtus Engineering, in addition to measuring output from 8 utility scale PV arrays totaling nearly 100 MW of capacity. The sensor network was designed to mirror the National Digital Forecast Database 5km grid; SMUD sensors were placed in the middle of the grid cells. The work described in this paper examines the state of the art forecasting accuracies for utility scale PV plants and irradiance forecasts over a uniformly spaced geographic area. This study offers insight into the geospatial portion of the forecast, as solar forecasters move to more advanced techniques. The results from this trial drive inputs to how SMUD can improve solar forecast usefulness and implement new tools such as a distributed generation forecast. C1 [Bartholomy, Obadiah] SMUD, Sacramento, CA 95820 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Bartholomy, O (reprint author), SMUD, Sacramento, CA 95820 USA. NR 2 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 63 EP 68 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900017 ER PT J AU Li, H Jiang, CS Metzger, W Shih, CK Al-Jassim, M AF Li, Huan Jiang, Chun-Sheng Metzger, Wyatt Shih, Chih-Kang Al-Jassim, Mowafak GP IEEE TI Nanometer-Scale Study of Resistance on CdTe Solar Cell Devices SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE thin-film PV; micro-electrical property; characterization; scanning probe microscopy ID POLYCRYSTALLINE CDS/CDTE HETEROJUNCTIONS; THIN-FILMS; DIFFUSION; MICROSCOPY; SULFUR AB We report a nanometer-resolution resistance mapping across the junction of a CdTe solar cell by using scanning spreading resistance microscopy. The multiple device layers were identified by the resistance mapping. The nonuniform resistance in the CdTe layer reflects the nonuniformity of the doping in the CdTe. A high-resistance region close to the junction in the CdTe side as a result of carrier depletion was measured. With a forward bias voltage applied to the device, we observed the decrease of the resistance in the depletion region and the movement of the depletion region toward the CdS/CdTe interface as a result of the carrier injection. We compared the resistance of the device in the dark to that of the device in illumination. With the atomic force microscope laser illumination, the resistance in the deep depletion region decreased and the resistance across the entire device became relatively uniform. The results illustrate that under illumination, photo-excited carriers dominate the device over the carriers in the thermoequilibrium state and the carriers injected by the bias voltage to the device. C1 [Li, Huan; Jiang, Chun-Sheng; Metzger, Wyatt; Al-Jassim, Mowafak] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Li, Huan; Shih, Chih-Kang] Univ Texas Austin, Dept Phys, Austin, TX 78712 USA. RP Li, H (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI jiang, chun-sheng/F-7839-2012 NR 16 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 90 EP 94 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900022 ER PT J AU Rourke, D Ahn, S Nardes, A van de Lagemaat, J Kopidakis, N Park, W AF Rourke, Devin Ahn, Sungmo Nardes, Alexandre van de lagemaat, Jao Kopidakis, Nikos Park, Wounjhang GP IEEE TI Comprehensive Device Modeling of Plasmon-Enhanced and Optical Field-Dependent Photocurrent Generation in Organic Bulk Heterojunctions SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE Heterojunctions; Nanophotonics; Numerical models; Organic; Photovoltaic cells; Plasmons; Semiconductor device modeling ID CHARGE-TRANSFER STATES AB We present a comprehensive numerical model to describe the coupled optical and electrical behavior of plasmon-enhanced polymer/fullerene bulk heterojunction solar cells. We incorporate a bound electron/hole pair generation rate that is dependent on both the 2-dimensional position within the P3HT:PCBM active layer, and the solar spectral irradiance. By considering the absorption and plasmonic properties of two different popular device architectures, and applying the Poisson, current continuity, and drift/diffusion equations, we are able to predict quantum efficiency, short-circuit current density, and desired carrier mobility ratios for devices possessing strongly non-uniform optical fields commonly produced by nanostructures. C1 [Rourke, Devin] Univ Colorado, Dept Phys, Boulder, CO 80309 USA. [Ahn, Sungmo; Park, Wounjhang] Univ Colorado, Dept Elect Comp & Energy Engn, Boulder, CO 80309 USA. [Nardes, Alexandre; van de lagemaat, Jao; Kopidakis, Nikos] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Rourke, D (reprint author), Univ Colorado, Dept Phys, Boulder, CO 80309 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 143 EP 146 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900033 ER PT J AU Fields, JD Dabney, MS Bollinger, VP van Hest, MFAM AF Fields, Jeremy D. Dabney, Matthew S. Bollinger, Vincent P. van Hest, Maikel F. A. M. GP IEEE TI Printed Monolithic Interconnects for Photovoltaic Applications SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE interconnects; photovoltaics; atmospheric processing ID SOLAR-CELL AB Monolithic interconnects in photovoltaic modules connect adjacent cells in series, and are typically formed sequentially, involving multiple deposition and scribing steps. Interconnect widths on the order of 500 mu m every 10 mm result in about 5% dead area, which does not contribute to power generation in an interconnected solar panel. This work introduces an alternative interconnection method capable of producing interconnect widths of less than 100 mu m, which can be accomplished in a single pass after deposition of active layers and electrodes. This alternative method can be used for all types of thin film photovoltaics. Voltage addition using printed interconnects and ongoing efforts to optimize performance of modules with printed interconnect are discussed. C1 [Fields, Jeremy D.; Dabney, Matthew S.; Bollinger, Vincent P.; van Hest, Maikel F. A. M.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Fields, JD (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 158 EP 161 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900036 ER PT J AU Andrews, RW Stein, JS Hansen, C Riley, D AF Andrews, Robert W. Stein, Joshua S. Hansen, Clifford Riley, Daniel GP IEEE TI Introduction to the Open Source PV_LIB for Python Photovoltaic System Modelling Package SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE PV modelling; software; data analysis; performance modelling AB The proper modeling of Photovoltaic(PV) systems is critical for their financing, design, and operation. PV_LIB provides a flexible toolbox to perform advanced data analysis and research into the performance modeling and operations of PV assets, and this paper presents the extension of the PV_LIB toolbox into the python programming language. PV_LIB provides a common repository for the release of published modeling algorithms, and thus can also help to improve the quality and frequency of model validation and inter comparison studies. Overall, the goal of PV_LIB is to accelerate the pace of innovation in the PV sector. C1 [Andrews, Robert W.] Calama Consulting, Toronto, ON M5T 1B3, Canada. [Stein, Joshua S.; Hansen, Clifford; Riley, Daniel] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Andrews, RW (reprint author), Calama Consulting, Toronto, ON M5T 1B3, Canada. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 166 EP 170 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900038 ER PT J AU Hansen, CW Pohl, A AF Hansen, Clifford W. Pohl, Andrew GP IEEE TI Which Models Matter: Uncertainty and Sensitivity Analysis for Photovoltaic Power Systems SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE uncertainty; photovoltaic system performance; models ID IRRADIANCE AB Predicting power for a photovoltaic system from measured irradiance requires a sequence of models, e.g.: translation of measured irradiance to the plane-of-array; estimation of cell temperature; and calculation of module electrical output. Uncertainty in predicted power arises from the aggregate uncertainty in the various models used. But which models contribute significantly, or insignificantly, to this aggregate uncertainty? We report an uncertainty and sensitivity analysis that partially addresses this question. At each step in the modeling process, we consider commonly-used models and quantify uncertainty in the model and its parameters by analyzing model residuals obtained by comparing model predictions to available measurements. We are not yet able to quantify uncertainty in all relevant modeling steps. We develop stochastic process models for these residuals and use Monte Carlo sampling to propagate uncertainty from step to step. Propagating uncertainty through all modeling steps, we obtain a sample of values for PV system output representing the aggregate uncertainty in this quantity. We use rank correlations to identify the relative contribution to the aggregate uncertainty that can be attributed to each modeling step. For the steps and models we consider, we find that uncertainty in plane-of-array transposition and in effective irradiance models dominates the uncertainty in energy production; uncertainty in cell temperature and in module DC output is significantly less influential. C1 [Hansen, Clifford W.; Pohl, Andrew] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Hansen, CW (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 15 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 171 EP 176 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900039 ER PT J AU Duck, BC Fell, CJ Campanelli, M Zaharatos, B Marion, B Emery, K AF Duck, Benjamin C. Fell, Christopher J. Campanelli, Mark Zaharatos, Brian Marion, Bill Emery, Keith GP IEEE TI Determining uncertainty for I-V translation equations SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE accuracy; energy measurement; photovoltaic effects; prediction algorithms; standards ID MODEL AB Photovoltaic energy yield predictions rely on methods that estimate outdoor performance under arbitrary conditions based on a set of reference measurements. The uncertainty in these predictions has direct economic impacts on both the perceived feasibility of new systems and the energy market value. A common approach uses a set of translation equations such as those proposed in IEC 60891. Previous work examining the performance of the standard translation methods has not addressed the important issue of uncertainty. This is due to both a lack of comprehensive test data, and the scope of the problem resulting from flexibility in the way these methods can be applied. We used synthetic data to characterize the behavior of these standard translation methods in the presence of input uncertainty. The inputs and their uncertainty can then be mapped to the prediction uncertainty over a wide range of conditions. C1 [Duck, Benjamin C.; Fell, Christopher J.] CSIRO Energy Technol, Newcastle, NSW 2300, Australia. [Duck, Benjamin C.; Campanelli, Mark; Zaharatos, Brian; Marion, Bill; Emery, Keith] NREL, Golden, CO 80401 USA. RP Duck, BC (reprint author), CSIRO Energy Technol, POB 330, Newcastle, NSW 2300, Australia. NR 14 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 177 EP 182 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900040 ER PT J AU Kazmerski, LL Al Jardan, M Al Jnoobi, Y Al Shaya, Y John, JJ AF Kazmerski, Lawrence L. Al Jardan, Mohammed Al Jnoobi, Yasser Al Shaya, Yousef John, Jim J. GP IEEE TI Ashes to Ashes, Dust To Dust: Averting a Potential Showstopper for Solar Photovoltaics SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE module soiling; dust; dust properties; mitigation; cleaning; coatings AB Soiling, especially the sedimentation of dust particles on the exposed surfaces of solar collectors, is critical to the operation of solar systems-even possibly a "showstopper" in many regions of the world. Historically, this important issue has received intermittent research attention over the past 7-decades, with studies mainly focused on the relationship of dust accumulation to performance. Significantly fewer studies relate to the mitigation using coatings and other physical mechanisms. Cleaning methods have also been limited in scope, primarily using solutions or techniques that are water-based. Recently, interest has been increasing with the growing markets and adoption of solar technologies in the MENA (Middle East and North Africa) and desert regions, where sand particles (1-mu m to 500-mu m) are problems. This becomes serious when combined with dew or other moisture forming cementitious coatings that can be difficult to remove. This paper provides a comprehensive review of past and recent research work on the impact of dust on solar-PV performance with a focus on issues relating to MENA/desert regions. This paper also reports on progress with dust mitigation approaches. We report our contributions in the microscopic and chemical composition analyses of the "dust samples" from various MENA and India-showing differences in composition, morphology that can affect accumulation and resulting performance. The focus is on PV (glass) surfaces. Alternative methods (mechanical, electrostatic, liquid, vibrational) for cleaning these surfaces are also examined. Some future research directions & technology requirements are cited. C1 [Kazmerski, Lawrence L.; Al Jardan, Mohammed; Al Jnoobi, Yasser; Al Shaya, Yousef] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Kazmerski, Lawrence L.] Univ Colorado, Boulder, CO 80306 USA. [Al Jardan, Mohammed; Al Jnoobi, Yasser; Al Shaya, Yousef] KACARE, Riyadh, Saudi Arabia. [John, Jim J.] Indian Inst Technol, Bombay, Maharashtra, India. RP Kazmerski, LL (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 9 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 183 EP 188 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900041 ER PT J AU Burton, PD King, BH AF Burton, Patrick D. King, Bruce H. GP IEEE TI Determination of a Minimum Soiling Level to Affect Photovoltaic Devices SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE Photovoltaic cells; surface contamination; performance loss; standardized test methods; soiling ID DUST AB Soil accumulation on photovoltaic (PV) modules presents a challenge to long-term performance prediction and lifetime estimates due to the inherent difficulty in quantifying small changes over an extended period. Low mass loadings of soil are a common occurrence, but remain difficult to quantify. In order to more accurately describe the specific effects of sparse soil films on PV systems, we have expanded upon an earlier technique to measure the optical losses due to an artificially applied obscurant film. A synthetic soil analogue consisting of AZ road dust and soot in acetonitrile carrier solvent was sprayed onto glass coupons at very brief intervals with a high volume, low pressure pneumatic sprayer. Light transmission through the grime film was evaluated using a QE test stand and UV/vis spectroscopy. A 0.1 g/m(2) grime loading was determined to be the limit of mass measurement sensitivity, which is similar to some reports of daily soil accumulation. Predictable, linear decreases in transmission were observed for samples with a mass loading between 0.1 and 0.5 g/m(2). Reflectance measurements provided the best means of easily distinguishing this sample from a reference. C1 [Burton, Patrick D.; King, Bruce H.] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Burton, PD (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM pdburto@sandia.gov NR 13 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 189 EP 193 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900042 ER PT J AU Lotfi, H Hinkey, RT Li, L Yang, RQ Klem, JF Keay, JC Johnson, MB AF Lotfi, Hossein Hinkey, Robert T. Li, Lu Yang, Rui Q. Klem, John F. Keay, Joel C. Johnson, Matthew B. GP IEEE TI Multi-Stage Photovoltaic Devices with a Cutoff Wavelength of similar to 3 mu m SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE infrared; interband cascade; thermophotovoltaics; type-II superlattice ID CONVERSION AB Multi-stage Interband Cascade Photovoltaic (ICPV) devices with a room-temperature cutoff wavelength of similar to 3 mu m were investigated. These devices were characterized at various temperatures under illumination from both a blackbody source and an interband cascade (IC) laser (emission wavelength of similar to 2.86 mu m). Under laser illumination (8.0 W/cm(2)) an open-circuit voltage (V-oc) of 447 mV with a short-circuit current density (J(sc)) of 1.5 A/cm(2) was obtained from a three-stage device at room temperature. Studies of size dependence with different devices found significant surface leakage current, resulting in low fill factors in these devices. These results suggest a great potential of ICPV devices to attain higher V-oc at lower J(sc) compared to conventional single-absorber thermophotovoltaic (TPV) cells. C1 [Lotfi, Hossein; Hinkey, Robert T.; Li, Lu; Yang, Rui Q.] Univ Oklahoma, Sch Elect & Comp Engn, Norman, OK 73019 USA. [Hinkey, Robert T.; Keay, Joel C.; Johnson, Matthew B.] Univ Oklahoma, Homer L Dodge Dept Phys & Astron, Norman, OK 73019 USA. [Klem, John F.] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Lotfi, H (reprint author), Univ Oklahoma, Sch Elect & Comp Engn, Norman, OK 73019 USA. NR 9 TC 0 Z9 0 U1 3 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 220 EP 223 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900050 ER PT J AU McCarthy, RF Weimer, MS Hock, AS Martinson, ABF AF McCarthy, Robert F. Weimer, Matthew S. Hock, Adam S. Martinson, Alex. B. F. GP IEEE TI Chemical and Spatial Control of Substitutional Intermediate Band Materials: Toward the Atomic Layer Deposition of V0.25In1.75S3 SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE atomic layer deposition; indium sulfide; intermediate band photovoltaics; thin film semiconductors; vanadium sulfide ID SOLAR-CELLS; INDIUM; IN2O3; VAPOR; FILMS; OXIDE AB A few heavily substituted metal sulfides have been predicted to form intermediate band (IB) materials. While early experiments with powdered material have shown great promise, a synthetic approach to thin film growth is lacking. Here we report an atomic layer deposition (ALD) approach to fabricate V0.25In1.75S3 IB thin films with the potential for unique alloying control. Many commercial indium and vanadium precursors were explored, but their surface chemistries were unsatisfactory with H2S. Instead, a novel indium(III) amidinate precursor enables the growth of largely impurity-free In2S3 films. Thin films with promising optoelectronic properties have been tested and characterized. Additionally, vanadium alloying has commenced using a novel vanadium(III) amidinate precursor, and the first evidence of sub-band gap absorption has been observed. C1 [McCarthy, Robert F.; Weimer, Matthew S.; Hock, Adam S.; Martinson, Alex. B. F.] Argonne Natl Lab, Argonne, IL 60439 USA. [McCarthy, Robert F.; Weimer, Matthew S.; Hock, Adam S.] IIT, Chicago, IL 60616 USA. RP McCarthy, RF (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 11 TC 1 Z9 1 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 250 EP 253 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900057 ER PT J AU Deceglie, MG Silverman, TJ Marion, B Kurtz, SR AF Deceglie, Michael G. Silverman, Timothy J. Marion, Bill Kurtz, Sarah R. GP IEEE TI Metastable Changes to the Temperature Coefficients of Thin-film Photovoltaic Modules SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE CIGS; photovoltaic; metastability; transient; light-soak; temperature coefficient AB Transient changes in the performance of thin-film modules with light exposure are a well-known and widely reported phenomenon. These changes are often the result of reversible metastabilities rather than irreversible changes. Here we consider how these metastable changes affect the temperature dependence of photovoltaic performance. We find that in CIGS modules exhibiting a metastable increase in performance with light exposure, the light exposure also induces an increase in the magnitude of the temperature coefficient. It is important to understand such changes when characterizing temperature coefficients and when analyzing the outdoor performance of newly installed modules. C1 [Deceglie, Michael G.; Silverman, Timothy J.; Marion, Bill; Kurtz, Sarah R.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Deceglie, MG (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 337 EP 340 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900076 ER PT J AU Garris, RL Li, JV Contreras, MA Ramanathan, K Mansfield, LM Egaas, B Kanevce, A AF Garris, Rebekah L. Li, Jian V. Contreras, Miguel A. Ramanathan, Kannan Mansfield, Lorelle M. Egaas, Brian Kanevce, Ana GP IEEE TI Efficient and Stable CIGS Solar Cells with ZnOS Buffer Layer SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE chemical bath deposition; copper indium gallium diselenide; high efficiency; novel buffer; thin-film solar cells; zinc oxysulfide AB A chemical bath deposition (CBD) ZnOS process has been designed to yield repeatable and robust ZnOS/CIGS solar cells that do not require light soaking or annealing to reach conversion efficiency levels comparable with CdS/CIGS solar cells. In this study, copper content was varied over a wide range to understand its impact on these devices. Capacitance and temperature-dependent performance measurements were used to characterize the electrical performance as a function of Cu composition. The optimum Cu concentration was found to be about the same for both CBD CdS and CBD ZnOS junctions. C1 [Garris, Rebekah L.; Li, Jian V.; Contreras, Miguel A.; Ramanathan, Kannan; Mansfield, Lorelle M.; Egaas, Brian; Kanevce, Ana] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Garris, RL (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Li, Jian/B-1627-2016 NR 5 TC 0 Z9 0 U1 1 U2 10 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 353 EP 356 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900080 ER PT J AU Kanevce, A Ramanathan, K Contreras, M AF Kanevce, Ana Ramanathan, Kannan Contreras, Miguel GP IEEE TI Impact of buffer and absorber properties in the vicinity of the interface on wide-gap Cu(In, Ga)Se-2 solar cell performance SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE CIGS; interface recombination; numerical modeling ID CUINSE2 AB One of the main reasons for the Voc deficit in Cu(In, Ga)Se-2 (CIGS) solar cells with a wide band gap is often attributed to interface recombination, which is a consequence of the defective heterointerface and encouraged by the non-ideal band alignment between the absorber and the CdS layer. Although a highly defective heterointerface is likely not avoidable, some properties of the buffer layer and the absorber material in the vicinity of the interface could decrease the recombination losses. Compositional variations in CIGS can result in a band gap increase at the absorber/buffer interface and type inversion in the absorber layer. Simulations predict the optimal depth of type inversion on wide band gap CIGS devices and the magnitude of device performance increase that can be expected from such structures. In addition, the benefit of the decreased thickness and increased doping of the buffer layer is calculated. The results are compared with a "standard" 1.15-eV CIGS device, where the benefits of such variations are significantly smaller. C1 [Kanevce, Ana; Ramanathan, Kannan; Contreras, Miguel] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Kanevce, A (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 382 EP 386 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900087 ER PT J AU Boucher, JW Ritenour, AJ Greenaway, AL Aloni, S Boettcher, SW AF Boucher, Jason W. Ritenour, Andrew J. Greenaway, Ann L. Aloni, Shaul Boettcher, Shannon W. GP IEEE TI Homojunction GaAs Solar Cells Grown by Close Space Vapor Transport SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE semiconductor epitaxial layers; photovoltaic cells; gallium arsenide; III-V semiconductor materials; pn junctions ID MOBILITY AB We report on the first pn junction solar cells grown by homoepitaxy of GaAs using close space vapor transport (CSVT). Cells were grown both on commercial wafer substrates and on a CSVT absorber film, and had efficiencies reaching 8.1%, open circuit voltages reaching 909 mV, and internal quantum efficiency of 90%. The performance of these cells is partly limited by the electron diffusion lengths in the wafer substrates, as evidenced by the improved peak internal quantum efficiency in devices fabricated on a CSVT absorber film. Unoptimized highly-doped n-type emitters also limit the photocurrent, indicating that thinner emitters with reduced doping, and ultimately wider band gap window or surface passivation layers, are required to increase the efficiency. C1 [Boucher, Jason W.] Univ Oregon, Dept Phys, Eugene, OR 97403 USA. [Boucher, Jason W.; Ritenour, Andrew J.; Greenaway, Ann L.; Boettcher, Shannon W.] Univ Oregon, Inst Mat Sci, Eugene, OR 97403 USA. [Ritenour, Andrew J.; Greenaway, Ann L.; Boettcher, Shannon W.] Univ Oregon, Dept Chem, Eugene, OR 97403 USA. [Aloni, Shaul] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Mol Foundry, Berkeley, CA 94720 USA. RP Boucher, JW (reprint author), Univ Oregon, Dept Phys, Eugene, OR 97403 USA. EM swb@uoregon.edu NR 13 TC 1 Z9 1 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 460 EP 464 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900106 ER PT J AU Cruz-Campa, JL Tauke-Pedretti, A Cederberg, JG Sanchez, CA Girard, GR Alford, C Aguirre, BA Luna, I Okandan, M Nelson, JS Nielson, GN AF Cruz-Campa, Jose L. Tauke-Pedretti, Anna Cederberg, Jeffrey G. Sanchez, Carlos A. Girard, Gerald R. Alford, Charles Aguirre, Brandon A. Luna, Ian Okandan, Murat Nelson, Jeffrey S. Nielson, Gregory N. GP IEEE TI Power maximization in III-V sub-millimeter, radial front contacted cells for thin micro-concentrators SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE solar cell; InGaAs; GaAs; bonded cells; compact concentrators AB Sub millimeter scale solar cells coupled with medium concentration lenses can reduce the balance of system costs of concentrating photovoltaics by creating thin and highly efficient concentrators with relaxed tracking requirements. This paper shows the design, fabrication, simulation, and testing of micro-sized photovoltaics that have unique perimeter front contacts outside the optical collection area. The design of the device considered the need for low resistance current carrying layers while minimizing optical losses. The paper also shows the successful fabrication of InGaAs cells as well as of GaAs cells transferred onto silicon substrates. The simulations and experimental measurements show that small cells of this type 1) suffered from slightly lower voltage levels caused by proportionally larger dark currents 2) peaked their efficiencies at higher concentration levels compared to larger ones 3) performed better overall. C1 [Cruz-Campa, Jose L.; Tauke-Pedretti, Anna; Cederberg, Jeffrey G.; Sanchez, Carlos A.; Girard, Gerald R.; Alford, Charles; Aguirre, Brandon A.; Luna, Ian; Okandan, Murat; Nelson, Jeffrey S.; Nielson, Gregory N.] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Cruz-Campa, JL (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 10 TC 0 Z9 0 U1 1 U2 4 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 471 EP 475 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900108 ER PT J AU Simon, J Young, D Ptak, A AF Simon, John Young, David Ptak, Aaron GP IEEE TI Low-Cost III-V Solar Cells Grown by Hydride Vapor-Phase Epitaxy SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE gallium arsenide; HVPE; photovoltaics ID GAAS AB The high epitaxial cost of high-efficiency III-V photovoltaic devices has limited these cells to niche markets. In this work, we demonstrate hydride vapor-phase epitaxy (HVPE) growth of III-V materials as a low-cost, high-throughput alternative to conventional metal-organic vapor-phase epitaxy (MOVPE). A brand new, custom-built HVPE reactor was used to obtain high-quality GaAs films at growth rates as high as 1.5 mu m/min (90 mu m/h). Near-ideal Hall mobilities for both n- and p-type carriers are demonstrated. Preliminary GaAs p-n junctions with unpassivated surfaces show significant rectifying behavior and excellent carrier collection, open-circuit voltage as high as 0.95 V, and fill factors of 86% under AM1.5G illumination. These results show the viability of HVPE for the growth of high-quality III-V devices at significantly lower costs. C1 [Simon, John; Young, David; Ptak, Aaron] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Simon, J (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 12 TC 3 Z9 3 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 538 EP 541 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900123 ER PT J AU Tauke-Pedretti, A Cederberg, JG Cruz-Campa, JL Alford, C Sanchez, CA Luna, I Nelson, JS Nielson, GN AF Tauke-Pedretti, Anna Cederberg, Jeffrey G. Cruz-Campa, Jose L. Alford, Charles Sanchez, Carlos A. Luna, Ian Nelson, Jeffrey S. Nielson, Gregory N. GP IEEE TI Bonded InGaAs Cells for Microsystems Enabled Photovoltaics SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE multi-junction solar cells; wafer bonding; photovoltaic cells; III-V solar cells AB InGaAs solar cells bonded to a Si substrate are demonstrated. These cells are 160 mu m to 1300 mu m in diameter and designed for integration in microsystems enabled photovoltaic systems. When compared to devices fabricated on substrate no degradation of cell performance was observed due to bonding. Additionally, the short circuit current for the cells correlated well with simulations indicating a low loss optical path through the bonding interface. C1 [Tauke-Pedretti, Anna; Cederberg, Jeffrey G.; Cruz-Campa, Jose L.; Alford, Charles; Sanchez, Carlos A.; Luna, Ian; Nelson, Jeffrey S.; Nielson, Gregory N.] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Tauke-Pedretti, A (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 5 TC 0 Z9 0 U1 1 U2 5 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 546 EP 549 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900125 ER PT J AU Chaukulkar, R Nemeth, W Dameron, A Stradins, P Agarwal, S AF Chaukulkar, Rohan Nemeth, William Dameron, Arrelaine Stradins, Paul Agarwal, Sumit GP IEEE TI Study of the Passivation Mechanism of c-Si by Al2O3 Using in situ Infrared Spectroscopy SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE charge-carrier lifetime; dielectric films; photovoltaic cells; silicon; thin-film devices ID SURFACE; EFFICIENCY; DEUTERIUM AB We present an in situ attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy study of the passivation mechanism in the surface passivation of Si solar cells by Al2O3 thin films deposited via atomic layer deposition (ALD) using TMA and O-3 as precursors. The IR measurements suggest that during the annealing stage, the Si-H bonding near the interface decreases. We have used D-terminated c-Si internal-reflection crystals to differentiate the residual H atoms that may migrate from ALD Al2O3 films versus the residual D atoms present at the Al2O3/c-Si interface after ALD. Within the sensitivity of the ATR-FTIR spectroscopy setup of similar to 10(12) cm(-2) for Si-H bonds, we do not detect any migration of H from Al2O3 to the c-Si interface. Therefore, we conclude that the migration of O, and the subsequent restructuring of the interface during the annealing step, primarily contributes toward the chemical passivation of the Al2O3/c-Si interface. C1 [Chaukulkar, Rohan; Agarwal, Sumit] Colorado Sch Mines, Golden, CO 80401 USA. [Nemeth, William; Dameron, Arrelaine; Stradins, Paul] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Chaukulkar, R (reprint author), Colorado Sch Mines, Golden, CO 80401 USA. NR 12 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 582 EP 585 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900133 ER PT J AU Lee, BG Nemeth, W Yuan, HC Page, MR LaSalvia, V Young, DL Stradins, P AF Lee, Benjamin G. Nemeth, William Yuan, Hao-Chih Page, Matthew R. LaSalvia, Vincenzo Young, David L. Stradins, Paul GP IEEE TI Heterojunction Rear Passivated Contact for High Efficiency n-Cz Si Solar Cells SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA AB We investigate the challenges and potential for high-efficiency n-type Cz Si solar cells having a hybrid structure - a diffused B emitter on the front side, and an amorphous Si heterojunction (SHJ) passivated full-area contact on the rear. This cell design has benefits over comparable high-efficiency geometries such as PERL (passivated emitter rear locally diffused) and SHJ cells with heterojunctions both front and rear. We show that an advantage of the HJ rear contact is excellent passivation of the backside, with measured contact recombination current density J(0,b,c) < 10 fA/cm(2); moreover, compared to PERL, its cell fabrication process is much simpler. Weighed against standard SHJ cells, the diffused front results in less optical loss and no need for a transparent conducting oxide (TCO). We study the contact resistivity of a state-of-the-art SHJ rear contact to the wafer, finding a value of similar to 0.3 ohm-cm(2); a series of experiments are performed to reduce this value while maintaining potential for high V-oc > 700 mV. As an initial demonstration of the concept, we fabricate a hybrid-structure cell having V-oc = 671 mV, J(sc) = 36.7 mA/cm(2), FF = 0.75 and efficiency of 18.5%. C1 [Lee, Benjamin G.; Nemeth, William; Yuan, Hao-Chih; Page, Matthew R.; LaSalvia, Vincenzo; Young, David L.; Stradins, Paul] Natl Renewable Energy Lab, Natl Ctr Photovolta, Golden, CO 80401 USA. RP Lee, BG (reprint author), Natl Renewable Energy Lab, Natl Ctr Photovolta, Golden, CO 80401 USA. NR 5 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 612 EP 614 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900141 ER PT J AU Nemeth, B Yuan, HC Page, M LaSalvia, V Chaukulkar, R Gedvilas, L Li, JV Stradins, P AF Nemeth, Bill Yuan, Hao-Chih Page, Matthew LaSalvia, Vincenzo Chaukulkar, Rohan Gedvilas, Lynn Li, Jian V. Stradins, Paul GP IEEE TI Dielectric Stack Passivation on Boron-and Phosphorus-Diffused Surfaces and 20% Efficient PERT Cell on n-CZ Silicon Substrate SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE silicon solar cells; passivation; silicon nitride; silicon dioxide AB We present a surface passivation study of a B-diffused emitter and P-diffused back-surface field (BSF) of n-CZ Si substrates. The optimized passivation layers are subsequently incorporated into a 20%-efficient passivated emitter, rear totally-diffused (PERT) cell with V-oc of 672 mV. On the P-diffused, concentrated KOH-planarized BSF side, we compare different passivating plasma enhanced chemical vapor deposition (PECVD) SiNx layer compositions. We demonstrate that a favorable combination of best passivation quality is achieved by a stack of thermal oxide grown at similar to 700 degrees C, followed by a bilayer SiNx, consisting of stoichiometric PECVD nitride and capped with Si-rich nitride, or H-dilution nitride. The stack results in surface passivation quality of J(o) similar to 17 fA/cm(2) for bilayer SiNx and 14 fA/cm(2) for H-SiNx on lightly P-doped BSF, and is very resistive to HF-containing wet etches. Surface preparation, deposition parameters, and post-growth annealing collaborate to define the effectiveness of the passivation. Their optimization is critical for integration of SiNx:H into our high-efficiency solar cells. On the B-diffused textured emitter side, we use atomic layer deposition (ALD)-deposited Al2O3 for surface passivation and low-temperature stoichiometric PECVD SiNx for the anti-reflection coating. We discuss deposition conditions and thermal treatments for both ALD Al2O3 and PECVD nitride that result in the optimized passivation resulting in J(o) similar to 52 fA/cm(2) and that prevent the blistering of the film. C1 [Nemeth, Bill; Yuan, Hao-Chih; Page, Matthew; LaSalvia, Vincenzo; Gedvilas, Lynn; Li, Jian V.; Stradins, Paul] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Chaukulkar, Rohan] Colorado Sch Mines, Golden, CO 80401 USA. RP Nemeth, B (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. RI Li, Jian/B-1627-2016 NR 9 TC 0 Z9 0 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 629 EP 633 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900146 ER PT J AU Sopori, B Devayajanam, S Basnyat, P Moutinho, H Nemeth, B LaSalvia, V Johnston, S Binns, J Appee, J AF Sopori, Bhushan Devayajanam, Srinivas Basnyat, Prakash Moutinho, Helio Nemeth, Bill LaSalvia, Vincenzo Johnston, Steve Binns, Jeff Appee, Jesse GP IEEE TI Some Challenges in Making Accurate and Reproducible Measurements of Minority Carrier Lifetime in High-Quality Si Wafers SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE charge carrier lifetime; defects; oxidation; passivation; silicon ID SILICON AB Measurement of the minority carrier lifetime (tau) of high-quality wafers (having bulk minority carrier lifetime, tau(b) > few milliseconds) requires surface passivation with very low surface recombination velocity, typically <1cm/s. Furthermore, for mapping large (e.g., 156 x156 mm) wafers, the passivation must also be stable and uniform over the entire wafer surfaces. These are very demanding requirements and it is a common experience that they are very difficult to achieve. Yet, they are necessary for performing defect analyses of the current N-type wafers. To understand the problems associated with these measurements, we have studied effect of wafer preparation (cleaning procedures, handling) and the passivation characteristics (stability, sensitivity to light, thickness of the passivation medium required for stable passivation) for many commonly used passivation media-iodine-ethanol (IE), qumhydrone-methanol (QHM), aluminum oxide (Al2O3), amorphous-silicon (a-Si), and silicon dioxide (SiO2). Here, we will discuss main factors that influence the accuracy and repeatability of lifetime measurements. C1 [Sopori, Bhushan; Devayajanam, Srinivas; Basnyat, Prakash; Moutinho, Helio; Nemeth, Bill; LaSalvia, Vincenzo; Johnston, Steve] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Binns, Jeff] SunEdison, St Peters, MO USA. [Appee, Jesse] SunEdison, Portland, OR USA. RP Sopori, B (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 649 EP 654 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900151 ER PT J AU Pang, YT Eisaman, MD AF Pang, Yutong Eisaman, Matthew D. GP IEEE TI Measuring Refractive Index Profiles within Thin-Film Photovoltaics with High Spatial Resolution using the Modified IM-IWKB Method SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE photovoltaic cells; refractive index; semiconductor films; semiconductor waveguides; solar energy; thin films ID OPTICAL WAVE-GUIDES AB We derive a correction to the phase contribution for the reconstruction of refractive index profiles within thin-film photovoltaics using the Index Matched Inverse Wentzel-Kramers-Brillouin (IM-IWKB) Method. We quantify the improvement of the refractive-index reconstruction due to this modification for structures typical of organic photovoltaics. Near the low-index surface of the photoactive layer, this modification reduces the fractional error in the reconstructed profile by a factor of ten, resulting in a highly accurate refractive index reconstruction throughout the entire film thickness. This technique is applicable to the reconstruction of the refractive index profiles within any thin-film photovoltaic material. C1 [Pang, Yutong; Eisaman, Matthew D.] Brookhaven Natl Lab, Sustainable Energy Technol Dept, Upton, NY 11973 USA. [Pang, Yutong; Eisaman, Matthew D.] SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11790 USA. [Eisaman, Matthew D.] SUNY Stony Brook, Dept Elect & Comp Engn, Stony Brook, NY 11790 USA. RP Pang, YT (reprint author), Brookhaven Natl Lab, Sustainable Energy Technol Dept, Upton, NY 11973 USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 655 EP 659 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900152 ER PT J AU Li, JV Grover, S Repins, IL Keyes, BM Contreras, MA Ramanathan, K Noufi, R Zhao, ZB Liao, F AF Li, Jian V. Grover, Sachit Repins, Ingrid L. Keyes, Brian M. Contreras, Miguel A. Ramanathan, Kannan Noufi, Rommel Zhao, Zhibo Liao, Feng GP IEEE TI Electrical Characterization of Interface Recombination and its Dependence on Band Offset, Potential Barrier Height, and Inversion in Certain Heterojunction Solar Cells SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE interface; recombination; contact; open-circuit voltage; capacitance spectroscopy AB The open-circuit voltage V-OC of a heterojunction solar cell of the generic TCO/buffer/absorber/back-contact structure is sensitively influenced by the interface recombination at the buffer/absorber front interface R-i,R-f and at the absorber/back-contact interface R-i,R-b. We describe an experimental method to separate and quantify these interface recombination rates and the bulk recombination rates from the dependencies of V-OC on temperature and illumination with varying wavelength. We show that R-i,R-f is mainly determined by the potential barrier height phi(b0) at the buffer/absorber interface. We discuss strategies to increase phi(b0) by engineering band offset, band bending, and inversion. C1 [Li, Jian V.; Repins, Ingrid L.; Keyes, Brian M.; Contreras, Miguel A.; Ramanathan, Kannan; Noufi, Rommel] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Grover, Sachit] Scifiniti Inc, San Jose, CA 95134 USA. [Zhao, Zhibo; Liao, Feng] First Solar, Perrysburg, OH 43551 USA. RP Li, JV (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Li, Jian/B-1627-2016 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 978-1-4799-4398-2 PY 2014 BP 686 EP 689 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900158 ER PT J AU Sopori, B Yuan, HC Devayajanam, S Basnyat, P LaSalvia, V Norman, A Page, M Nemeth, B Stradins, P AF Sopori, Bhushan Yuan, Hao-Chih Devayajanam, Srinivas Basnyat, Prakash LaSalvia, Vincenzo Norman, Andrew Page, Matt Nemeth, Bill Stradins, Paul GP IEEE TI Bulk Defect Generation during B-Diffusion and Oxidation of CZ Wafers: Mechanism for Degrading Solar Cell Performance SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE Silicon; defects; diffusion; etching; oxidation; minority carrier lifetime degradation; stacking faults ID INDUCED STACKING-FAULTS; SILICON; GROWTH AB We describe results of our experimental study to investigate the effect of B diffusion and drive-in/oxidation on minority carrier lifetime of the wafer. We have observed that B diffusion generates stacking faults that can be attributed to injection of Si interstitials into the wafer by formation of a boron rich layer at the wafer surface. These Si interstitials are also believed to enhance interactions between the native point defects and impurities (such as 0, Fe) in the wafers during subsequent processing leading to the development of swirl patterns. Spatial variation of the lifetime degradation follows the point defect interactions and impurity segregation/precipitation. Lifetime can be partially recovered by Phosphorous (P) gettering. The overall effect on the cell performance due to Si interstitial generation, impurity/point defect interactions, and P-gettering is briefly discussed. C1 [Sopori, Bhushan; Yuan, Hao-Chih; Devayajanam, Srinivas; Basnyat, Prakash; LaSalvia, Vincenzo; Norman, Andrew; Page, Matt; Nemeth, Bill; Stradins, Paul] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Devayajanam, Srinivas; Basnyat, Prakash] New Jersey Inst Technol, Newark, NJ 07102 USA. RP Sopori, B (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Norman, Andrew/F-1859-2010 OI Norman, Andrew/0000-0001-6368-521X NR 7 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 719 EP 723 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900165 ER PT J AU Caruso, AE Pruzan, DS Kosyak, V Bhatia, A Lund, EA Beall, C Repins, I Scarpulla, MA AF Caruso, A. E. Pruzan, D. S. Kosyak, V. Bhatia, A. Lund, E. A. Beall, C. Repins, I. Scarpulla, M. A. GP IEEE TI Temperature Dependence of Equivalent Circuit Parameters Used to Analyze Admittance Spectroscopy and Application to CZTSe Devices SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE admittance spectroscopy; CZTS; CZTSe; equivalent circuit; capacitance methods AB We present a device physics and equivalent circuit model for admittance spectroscopy of CZTSe based photovoltaic devices. The experimental variations of the capacitance and conductance in the depletion width are reproduced for state of the art coevaporated CZTSe devices. We will show that simple Arrhenius analysis of the main capacitance step seen in CZTSe results in erroneous values for the dominant acceptor energy. We will also show that the bulk resistivity in the quasi-neutral region (QNR), even in the presence of the dominant acceptor freezeout, cannot account for the observed increase in series resistance which is responsible for the temperature dependent frequency shift of the capacitance step. Thus, we suggest that dopant freezeout must affect another component of the lumped series resistance such as a non-Ohmic back contact. C1 [Caruso, A. E.; Lund, E. A.; Scarpulla, M. A.] Univ Utah, Elect & Comp Engn Dept, Salt Lake City, UT 84112 USA. [Pruzan, D. S.; Kosyak, V.; Bhatia, A.; Scarpulla, M. A.] Univ Utah, Mat Sci & Engn Dept, Salt Lake City, UT USA. [Lund, E. A.] Univ Utah, Dept Chem Engn, Salt Lake City, UT 84112 USA. [Beall, C.; Repins, I.] Natl Renewable Energy Lab, Golden, CO USA. RP Caruso, AE (reprint author), Univ Utah, Elect & Comp Engn Dept, Salt Lake City, UT 84112 USA. OI Kosyak, Volodymyr/0000-0002-1578-4501; Bhatia, Ashish/0000-0002-2965-4863 NR 12 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 733 EP 736 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900168 ER PT J AU Fisher, B Ghosal, K Riley, D Hansen, C King, B Burroughs, S AF Fisher, Brent Ghosal, Kanchan Riley, Daniel Hansen, Clifford King, Bruce Burroughs, Scott GP IEEE TI Field Performance Modeling of Semprius CPV Systems SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE CPV; performance modeling; PVsyst; solar energy AB Semprius, a producer of high concentration photovoltaic (CPV) modules with world record efficiency, has developed capabilities for modeling field performance of CPV modules using two performance models: PVsyst and Semprius Performance Model (SPM). Modeling with PVsyst relies on the definition of a PAN file which is described here. SPM is the result of Semprius' collaboration with Sandia National Laboratory to develop software that can accurately model the field performance of Semprius CPV systems. The performance of both PVsyst and SPM is demonstrated for Semprius CPV by validation against actual Semprius CPV systems operating in the field, one in Tucson and one at Sandia National Labs, NM. These comparisons suggest that both of these models can accurately predict annual AC energy yield to within 1-3 percent. C1 [Fisher, Brent; Ghosal, Kanchan; Burroughs, Scott] Semprius Inc, Durham, NC 27713 USA. [Riley, Daniel; Hansen, Clifford; King, Bruce] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Fisher, B (reprint author), Semprius Inc, 4915 Prospectus Dr, Durham, NC 27713 USA. NR 5 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 759 EP 764 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900173 ER PT J AU Williams, JJ Jeffries, AM Ding, L Gangam, S Ghosh, K Williamson, TL Bertoni, MI Honsberg, CB AF Williams, Joshua J. Jeffries, April M. Ding, Laura Gangam, Srikanth Ghosh, Kunal Williamson, Todd L. Bertoni, Mariana I. Honsberg, Christiana B. GP IEEE TI Structural and Optical Investigations of GaN-Si Interface for a Heterojunction Solar Cell SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE gallium nitride; heterojunction; interface physics; molecular beam epitaxy; silicon AB In recent years the development of heterojunction silicon based solar cells has gained much attention, lead largely by the efforts of Panasonic's HIT cell. The success of the HIT cell prompts the scientific exploration of other thin film layers, besides the industrially accepted amorphous silicon. The band gap, mobilities, and electron affinity of GaN make it an interesting candidate to solve problems of parasitic absorption while selectively extracting electrons. Using a novel MBE based growth technique, thin films of GaN have been deposited at temperature significantly lower than industry standards. Crystalline measurements and absorption data of GaN are presented. Additionally, effects of deposition on the silicon wafer lifetimes are presented C1 [Williams, Joshua J.; Jeffries, April M.; Ding, Laura; Gangam, Srikanth; Ghosh, Kunal; Bertoni, Mariana I.; Honsberg, Christiana B.] Arizona State Univ, Tempe, AZ 85004 USA. [Williams, Joshua J.; Williamson, Todd L.] Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Williams, JJ (reprint author), Arizona State Univ, Tempe, AZ 85004 USA. NR 4 TC 0 Z9 0 U1 1 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 841 EP 843 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901014 ER PT J AU Steirer, KX Garris, RL Beall, C Kanevce, A Ramanathan, K Repins, I Teeter, G Perkins, CL AF Steirer, K. Xerxes Garris, Rebekah L. Beall, Carolyn Kanevce, Ana Ramanathan, Kannan Repins, Ingrid Teeter, Glenn Perkins, Craig L. GP IEEE TI Photoelectron Spectroscopy, and Photovoltaic Device Study of Cu2ZnSnSe4 and ZnOxS1-x Buffer Layer Interface SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE kesterite; quaternary; zinc oxysulfide; photoelectron spectroscopy; depth profile; buffer; SCAPS modeling; XPS; UPS ID SOLAR-CELLS AB Recent research has enabled Cu2ZnSnSe4 (CZTSe) to reach efficiencies close to 10% in photovoltaic devices with CdS as the junction partner and over 12% when the CZTSe is alloyed with sulfur. Little work, however, has been reported on the potential for wide band gap, Cd-free buffer layers in these devices. Reported here are photoelectron spectroscopy measurements (XPS/UPS) of the band energy positions between CZTSe and zinc oxysulfide (ZnOS) with sputter depth profiling. Measurements indicate the formation of a large conduction band offset (CBO) of 1.2 eV with chemical-bath deposition (CBD) of ZnOS on CZTSe (E-g = 0.96 eV). However, Ar ion sputter depth profiling is shown to produce compositional changes of the ZnOS thin film resulting in an apparent increase of the valence band maximum (VBM) for the buffer layer. With this in mind, the valence band edge energy offsets (VBO) are calculated and used to study solar cells made with the configuration glass/Mo/CZTSe/ZnOS/i-ZnO/Al:ZnO/Ni/Al. Variation of the deposition time of the ZnOS buffer layer during the CBD process has led to device efficiencies above 5%. For the thinnest ZnOS buffer layers, the short-circuit current matches that of devices with CdS buffer layers, but suffers from loss of open-circuit voltage. Interpretation of the solar cell measurements are aided by SCAPS thin-film device modeling. C1 [Steirer, K. Xerxes; Garris, Rebekah L.; Beall, Carolyn; Kanevce, Ana; Ramanathan, Kannan; Repins, Ingrid; Teeter, Glenn; Perkins, Craig L.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Steirer, KX (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 11 TC 0 Z9 0 U1 2 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 847 EP 851 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901016 ER PT J AU Guthrey, H Moseley, J Burst, J Metzger, W Al-Jassim, M AF Guthrey, Harvey Moseley, John Burst, James Metzger, Wyatt Al-Jassim, Mowafak GP IEEE TI Cathodoluminescence Study of Carrier Transport Across Grain Boundaries in CdTe SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE CdTe; cathodoluminescence; diffusion length; grain boundaries ID DIFFUSION LENGTHS; THIN-FILMS; RECOMBINATION AB It is widely reported that polycrystalline CdTe thin films yield higher conversion efficiency than their single crystal counterparts. However, the mechanism that increases the efficiency is not well understood despite a large body of work on the subject. In particular, understanding how grain boundaries affect carrier transport is crucial to providing future pathways for engineering higher efficiency devices. In this work, we adapted a method for observing carrier transport based on cathodoluminescence that had previously been used to determine diffusion lengths in pc-CdTe films and various III-V alloys to study individual grain boundaries. Utilizing large-grained CdTe (tens of mu m grain size) and site-specific specimen preparation, we observed how charge carriers interact with grain boundaries in CdTe. Our results suggest that carrier transport across grain boundaries in CdTe is influenced by the concentration of defect states in the material. C1 [Guthrey, Harvey; Moseley, John; Burst, James; Metzger, Wyatt; Al-Jassim, Mowafak] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Guthrey, H (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 15 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 869 EP 872 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901021 ER PT J AU Ahrenkiel, RK Johnston, SW Kuciauskas, D Tynan, J AF Ahrenkiel, R. K. Johnston, S. W. Kuciauskas, D. Tynan, Jerry GP IEEE TI Dual Sensor Technique for the Advanced Characterization Of Recombination Parameters in Photovoltaic Materials SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA ID MINORITY-CARRIER LIFETIME; SEMICONDUCTORS AB This work addresses the frequent discrepancy between transient photoconductive decay and transient photoluminescence decay. With this dual sensor technique, one measures the transient PC and PL decay simultaneously with the same incident light pulse, removing injection level uncertainty. Photoconductive decay measures the transient photoconductivity, Delta sigma(t). PCD senses carriers released from shallow traps as well as the photo-generated electron-hole pairs. In addition, variations in carrier mobility with injection level (and time) contribute to the decay time. PL decay senses only electron-hole recombination via photon emission. Theory and experiment will show that the time dependence of the two techniques can be quite different at high injection. C1 [Ahrenkiel, R. K.] Lakewood Semicond LLC, Lakewood, CO 80232 USA. [Ahrenkiel, R. K.; Johnston, S. W.; Kuciauskas, D.; Tynan, Jerry] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Ahrenkiel, RK (reprint author), Lakewood Semicond LLC, Lakewood, CO 80232 USA. 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 BN 978-1-4799-4398-2 PY 2014 BP 873 EP 878 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901022 ER PT J AU Kurtz, S Krishnani, P Freeman, J Flottemesch, R Riley, E Dierauf, T Newmiller, J Ngan, L Jordan, D Kimber, A AF Kurtz, Sarah Krishnani, Pramod Freeman, Janine Flottemesch, Robert Riley, Evan Dierauf, Tim Newmiller, Jeff Ngan, Lauren Jordan, Dirk Kimber, Adrianne GP IEEE TI PV System Energy Test SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE photovoltaic systems; model verification; photovoltaic performance; energy yield; performance guarantee AB The performance of a photovoltaic (PV) system depends on the weather, seasonal effects, and other intermittent issues. Demonstrating that a PV system is performing as predicted requires verifying that the system functions correctly under the full range of conditions relevant to the deployment site. This paper discusses a proposed energy test that applies to any model and explores the effects of the differences between historical and measured weather data and how the weather and system performance are intertwined in subtle ways. Implementation of the Energy Test in a case study concludes that test uncertainty could be reduced by separating the energy production model from the model used to transpose historical horizontal irradiance data to the relevant plane. C1 [Kurtz, Sarah; Freeman, Janine; Jordan, Dirk] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Krishnani, Pramod] Belectric, Newark, CA USA. [Flottemesch, Robert] Constellation, Baltimore, MD USA. [Riley, Evan] Black & Veatch Energy, San Francisco, CA USA. [Dierauf, Tim] SunPower Corp, San Jose, CA USA. [Newmiller, Jeff] DNV GL, San Ramon, CA USA. [Ngan, Lauren] First Solar, San Francisco, CA USA. [Kimber, Adrianne] Incident Power Consulting, Oakland, CA USA. RP Kurtz, S (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 16 TC 0 Z9 0 U1 2 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 879 EP 884 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901023 ER PT J AU Newmiller, J Erdman, W Stein, JS Gonzalez, S AF Newmiller, Jeff Erdman, William Stein, Joshua S. Gonzalez, Sigifredo GP IEEE TI Sandia Inverter Performance Test Protocol Efficiency Weighting Alternatives SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE inverter efficiency; DC-to-AC rating ratio; weighted efficiency AB The Sandia Inverter Performance Test Protocol defined two possible weighted-average efficiency values for use in comparing inverter performance, of which one definition was selected by the California Energy Commission for use in their Buydown incentive program leading to widespread use in the photo voltaic inverter market. This paper discusses the derivation of the efficiency weights originally proposed, and investigates the potential for defining new weights in light of increased array-to-inverter (DC-to-AC) system rating ratios in modern PV systems. C1 [Newmiller, Jeff] DNV GL, San Ramon, CA 94583 USA. [Erdman, William] Cinch, Lafayette, CA USA. [Stein, Joshua S.; Gonzalez, Sigifredo] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Newmiller, J (reprint author), DNV GL, San Ramon, CA 94583 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 897 EP 900 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901026 ER PT J AU Waters, M Berdnik, I Riley, E Tirumalai, T Kurtz, S Joyce, K AF Waters, Martin Berdnik, Irina Riley, Evan Tirumalai, Tejas Kurtz, Sarah Joyce, Kevin GP IEEE TI The Ability of Short Term Performance Tests to Reproduce the Results of a One-Year Adjusted Energy Test for Non-Concentrating PV Systems SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE photovoltaic systems power generation; solar power generation AB A variety of test methodologies are commonly used to assess if a photovoltaic ("PV") system is able to perform in-line with expectations generated by a computer simulation. Four commonly used methodologies include: the PVUSA rating as implemented in ASTM E2848 and E2939 ("ASTM"), a Performance Ratio Test ("PR"), the Power Performance Index ("PPI") and the Adjusted Energy Test ("AET"). This paper compares the results of a one year AET to short term ASTM, PR, PPI, and AET test results in an attempt to determine which test can best reproduce the results of a one-year AET. Test durations of 3, 7, 15, and 30 days were evaluated to examine the effect of test duration on the residual between the short term test result and the long term AET test result. Seasonality was also examined. This study was not able to identify a single test methodology which consistently outperformed the others, nor was this study able to determine the optimum test duration. C1 [Waters, Martin; Berdnik, Irina] Recurrent Energy, San Francisco, CA 94104 USA. [Riley, Evan; Tirumalai, Tejas; Joyce, Kevin] Black & Veatch Consulting Engineers, San Francisco, CA 94111 USA. [Kurtz, Sarah] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Waters, M (reprint author), Recurrent Energy, San Francisco, CA 94104 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 901 EP 906 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901027 ER PT J AU Kurtz, S Wohlgemuth, J Sample, T Yamamichi, M Kondo, M Kelly, G AF Kurtz, Sarah Wohlgemuth, John Sample, Tony Yamamichi, Masaaki Kondo, Michio Kelly, George GP IEEE TI Three-Prong Path to Comprehensive Technical Standards for Photovoltaic Reliability SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE reliability; photovoltaic systems; PV; quality management; accelerated testing ID MODULES AB As the photovoltaic (PV) industry has grown, the long-term reliability of PV systems has become increasingly important. Many organizations are taking on the challenge of this multi-faceted issue. This paper describes three closely coordinated efforts that together will provide a comprehensive set of consensus standards and specifications for the technical aspects of verifying PV system quality and bankability. These three efforts are developing standards for 1) qualifying the design for the intended application (climate zone and mounting configuration), 2) quality management systems for PV module manufacturing, and 3) system-level inspections to ensure appropriate design, installation, commissioning, and operation of PV systems. A pathway has been identified for international implementation of these standards through the International Electrotechnical Commission. C1 [Kurtz, Sarah; Wohlgemuth, John] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Sample, Tony] Commiss European Communities, JRC, I-21027 Ispra, Italy. [Yamamichi, Masaaki; Kondo, Michio] Natl Inst Adv Ind Sci & Technol, Tsukuba, Ibaraki, Japan. [Kelly, George] Sunset Technol Inc, Mt Airy, MD 21771 USA. RP Kurtz, S (reprint author), Natl Renewable Energy Lab, 15013 Denver West Pkwy, Golden, CO 80401 USA. NR 35 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 919 EP 924 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901031 ER PT J AU Hacke, P Terwilliger, K Glick, S Smith, R Perrin, G Kurtz, S Bosco, N Wohlgemuth, J AF Hacke, Peter Terwilliger, Kent Glick, Stephen Smith, Ryan Perrin, Greg Kurtz, Sarah Bosco, Nick Wohlgemuth, John GP IEEE TI Application of the Terrestrial Photovoltaic Module Accelerated Test-to-Failure Protocol SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE Energy conversion; Silicon AB The Terrestrial Photovoltaic Module Accelerated Test-to-Failure Protocol was applied to seven crystalline silicon module types to test the durability of the various module constructions on a quantitative basis in chamber and to evaluate the protocol itself. The modules under test are subdivided into three accelerated lifetime testing paths: 85 degrees C/85% relative humidity with system voltage bias, thermal cycling between - 40 degrees C and 85 degrees C, and paths that alternate between humidity with bias (one in each polarity) and thermal cycling. Three of the module types were also fielded to ascertain degradation mechanisms occurring in the natural environment for comparison to the mechanisms seen in the accelerated testing. Potential induced-degradation in modules negatively biased and silicon nitride antireflective coating thinning on cells in modules positively biased are among the important mechanisms that are seen both in the modules stressed in the natural environment and in chamber. Junction box failure, cell breakage, and acid-assisted metallization degradation are included in the mechanisms seen in chamber tests, and they vary significantly between module types. Per a goal of the accelerated test protocol, we found examples of modules with components and process methods that showed degradation mechanisms that occurred faster than incumbents that had satisfactory field experience. These were evaluated as opportunities for durability improvement. Conversely, types that showed substantial improvement were also seen, especially with respect to system voltage stress durability. C1 [Hacke, Peter; Terwilliger, Kent; Glick, Stephen; Perrin, Greg; Kurtz, Sarah; Bosco, Nick; Wohlgemuth, John] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Smith, Ryan] Pordis LLC, Austin, TX 78729 USA. RP Hacke, P (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 28 TC 0 Z9 0 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 930 EP 936 PG 7 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901033 ER PT J AU Meysing, DM Griffith, MM Rance, WL Reese, MO Burst, JM Wolden, CA Barnes, TM AF Meysing, D. M. Griffith, M. M. Rance, W. L. Reese, M. O. Burst, J. M. Wolden, C. A. Barnes, T. M. GP IEEE TI Properties of Oxygenated Cadmium Sulfide (CdS:O) and Their Impact on CdTe Device Performance SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE cadmium telluride; cadmium sulfide; thin-film photovoltaic cells; sputtering; optical band gap ID FILM SOLAR-CELLS AB In this work, we report on the development of a reactive sputtering process for CdS:O for high efficiency CdTe solar cells. X-ray diffraction, UV-Vis-NIR spectrophotometry, and Rutherford backscattering spectrometry were used to characterize the crystal structure, composition, and optical properties, respectively. All films were slightly Cd-rich, while the bulk oxygen content increased up to 45 at. % in direct proportion to the O-2 partial pressure. Optical absorption in cells was reduced by increasing the oxygen fraction in the sputtering ambient. Optimal performance was obtained from cells with CdS sputtered in a 6% O-2/Ar ambient, yielding efficiency >14% and V-OC>840 mV. C1 [Meysing, D. M.; Griffith, M. M.; Wolden, C. A.] Colorado Sch Mines, Golden, CO 80401 USA. [Rance, W. L.; Reese, M. O.; Burst, J. M.; Barnes, T. M.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Meysing, DM (reprint author), Colorado Sch Mines, Golden, CO 80401 USA. NR 10 TC 0 Z9 0 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 964 EP 967 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901040 ER PT J AU Battaglia, C de Nicolas, SM de Wolf, S Yin, XT Zheng, M Ballif, C Javey, A AF Battaglia, Corsin de Nicolas, Silvia Martin de Wolf, Stefaan Yin, Xingtian Zheng, Maxwell Ballif, Christophe Javey, Ali GP IEEE TI Hole Selective MoOx Contact for Silicon Heterojunction Solar Cells SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE heterojunction solar cells; high workfunction; molybdenum trioxide; passivation; photovoltaics; silicon; selective contact; x-ray photoelectron spectroscopy AB Efficient carrier selective contacts and excellent surface passivation are essential for solar cells to reach high power conversion efficiencies. Exploring MoO, as a dopant-free, hole-selective contact in combination with an intrinsic hydrogenated amorphous silicon passivation layer between the oxide and the crystalline silicon absorber, we demonstrate a silicon hetero-junction solar cell with a high open-circuit voltage of 711 mV and a power conversion efficiency of 18.8%. Compared to the traditional p-type hydrogenated amorphous silicon emitter of a traditional silicon heterojunction solar cell, we observe a substantial gain in photocurrent of 1.9 mA/cm(2) for MoO, due to its wide band gap of 3.3 eV. Our results on MoO, have important implications for other combinations of transition metal oxides and photovoltaic absorber materials. C1 [Battaglia, Corsin; Yin, Xingtian; Zheng, Maxwell; Javey, Ali] Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA. [Battaglia, Corsin; Yin, Xingtian; Zheng, Maxwell; Javey, Ali] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. [de Nicolas, Silvia Martin; de Wolf, Stefaan; Ballif, Christophe] Ecole Polytech Fed Lausanne, Photovolta & Thin Film Elect Lab, CH-2000 Neuchatel, Switzerland. RP Battaglia, C (reprint author), Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA. RI Yin, Xingtian/N-1743-2016; Battaglia, Corsin/B-2917-2010 OI Yin, Xingtian/0000-0001-9077-5982; NR 14 TC 0 Z9 0 U1 3 U2 6 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 968 EP 970 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901041 ER PT J AU Deline, C Sekulic, B Stein, J Barkaszi, S Yang, J Kahn, S AF Deline, Chris Sekulic, Bill Stein, Josh Barkaszi, Stephen Yang, Jeff Kahn, Seth GP IEEE TI Evaluation of Maxim Module-Integrated Electronics at the DOE Regional Test Centers SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE partial shading; MLPE; embedded power electronics; PV system performance; diffuse view factor ID FIELD AB Module-embedded power electronics developed by Maxim Integrated are under evaluation through a partnership with the Department of Energy's Regional Test Center (RTC) program. Field deployments of both conventional modules and electronics-enhanced modules are designed to quantify the performance advantage of Maxim's products under different amounts of interrow shading, and their ability to be deployed at a greater ground-coverage ratio than conventional modules. Simulations in PVSYST have quantified the predicted performance difference between conventional modules and Maxim's modules from interrow shading. Initial performance results have identified diffuse irradiance losses at tighter row spacing for both the Maxim and conventional modules. Comparisons with published models show good agreement with models predicting the greatest diffuse irradiance losses. At tighter row spacing, all of the strings equipped with embedded power electronics outperformed their conventional peers. An even greater performance advantage is predicted to occur in the winter months when the amount of interrow shading mismatch is at a maximum. C1 [Deline, Chris; Sekulic, Bill] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Stein, Josh] Sandia Natl Labs, Albuquerque, NM 87123 USA. [Barkaszi, Stephen] Florida Solar Energy Ctr, Cocoa, FL 32922 USA. [Yang, Jeff; Kahn, Seth] Maxim Integrated, San Jose, CA 95134 USA. RP Deline, C (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 14 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 986 EP 991 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901046 ER PT J AU Sena, SS Quiroz, JE Broderick, RJ AF Sena, Santiago S. Quiroz, Jimmy E. Broderick, Robert J. GP IEEE TI Analysis of 100 Utility SGIP PV Interconnection Studies SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE data analysis; distributed power generation; photovoltaic systems; power system interconnection; power system planning; standards development; statistical analysis AB Sandia National Laboratories (SNL) performed an analysis of 100 Small Generator Interconnection Procedure (SGIP) studies to identify the most common impacts from photovoltaic (PV) system interconnections of 20 MW or less and the impact mitigation costs. This report highlights the discoveries and describes the methodology used to develop the dataset of impacts. It was observed that 44% of facilities that entered the SGIP study processes identified no adverse system impacts. Interconnection topologies were strongly correlated to the presence/absence of adverse impacts. Protection impacts were the most common adverse system impact identified in the dataset. C1 [Sena, Santiago S.; Quiroz, Jimmy E.; Broderick, Robert J.] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Sena, SS (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1005 EP 1010 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901050 ER PT J AU Hoke, A Chakraborty, S Basso, T AF Hoke, Anderson Chakraborty, Sudipta Basso, Thomas GP IEEE TI Testing Advanced Photovoltaic Inverters Conforming to IEEE Standard 1547-Amendment 1 SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE Inverters; photovoltaic; electric power systems; reactive power control; voltage control; IEEE 1547; IEEE 1547.1 AB This paper introduces a new test plan and provides results for testing photovoltaic inverters with advanced grid support features including voltage regulation, wider voltage and frequency operating ranges, and voltage and frequency ride-through, as allowed by IEEE Standard 1547-Amendment 1. The test plan emphasizes testing for interactions between and among advanced inverter features and conventional features (e.g., unintentional islanding), and it includes testing of inverter dynamic response when regulating voltage. Results are included from testing of a single-phase inverter and a three-phase inverter. C1 [Hoke, Anderson; Chakraborty, Sudipta; Basso, Thomas] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Hoke, A (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. EM andy.hoke@nrel.gov; sudipta.chakraborty@nrel.gov; thomas.basso@nrel.gov 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 978-1-4799-4398-2 PY 2014 BP 1014 EP 1021 PG 8 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901052 ER PT J AU Aggarwal, S van Hest, MFAM Perkins, JD Ginley, DS AF Aggarwal, Shruti van Hest, Maikel F. A. M. Perkins, John D. Ginley, David S. GP IEEE TI Improving Mechanical Stability and Electrical Properties of Silver Nanowire Films with a Zinc Tin Oxide Overcoat SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE silver nanowires; transparent contacts; transparent conducting oxides; zinc tin oxide ID ORGANIC SOLAR-CELLS; ELECTRODES AB Silver nanowire (AgNW)-based transparent contacts are promising alternatives to transparent conducting oxides for solar cells owing to their promising optoelectronic properties. However, there is a need to improve issues such as adhesion to substrate, surface roughness, thermal instability, and loose contact between wires. If these issues could be resolved, it should be possible to replace the conducting oxide layers by AgNWs. In the present work, we report electrical, optical, and surface properties of silver nanowires with amorphous zinc tin oxide (ZTO) as overcoat. Two different sizes of silver nanowires have been employed for this study with average diameters of 35 nm (length = 10 mu m) and 90 nm (length = 25 mu m). Various concentrations of the solution and spin-coating speeds have been used to optimize transmittance and conductivity of bare AgNW films. After deposition, it is possible to improve conductivity by fusing wires through various processes such as thermal annealing. It is observed that thermal annealing at 200 degrees C or less shows improved conductivity. Sheet resistance of 9.8 Omega/sq and transmittance (at 550 nm) of 91% are obtained for 90 nm diameter wires at an annealing temperature of 200 degrees C. AgNW networks of varying sheet resistance and transmittance were over-coated with sputtered ZTO films of 20-, 50-, or 200-nm thickness. Microscope analysis of scratch-tested samples shows that 50-nm-thick ZTO film is sufficient to give robustness to the 90-nm AgNW films with minor changes to conductivity and transmittance. C1 [Aggarwal, Shruti; van Hest, Maikel F. A. M.; Perkins, John D.; Ginley, David S.] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Aggarwal, Shruti] Guru Gobind Singh Indraprastha Univ, New Delhi 110078, India. RP Aggarwal, S (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 10 TC 2 Z9 2 U1 4 U2 7 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1022 EP 1025 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901053 ER PT J AU Kim, Y Faleev, N Tang, DH Smith, D Kuciauskas, D Dippo, PC Honsberg, C AF Kim, Yeongho Faleev, Nikolai Tang, Dinghao Smith, David Kuciauskas, Darius Dippo, Patricia C. Honsberg, Christiana GP IEEE TI Structural and optical properties of multi-stack InAs/GaAsSb quantum dots with different Sb composition SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE quantum dots; intermediate band solar cells; crystalline defects; photoluminescence; carrier lifetime AB The impact of the Sb composition on the structural and optical properties of ten-stack InAs/GaAsSb quantum dots (QDs) were investigated using transmission electron microscopy (TEM), high-resolution x-ray diffraction (XRD), and photoluminescence (PL). The TEM images demonstrate that the Sb composition affects the change in the QD density and morphology. From analysis of XRD reciprocal space maps (RSMs) of the (224) asymmetrical reflection, it is found that as the Sb composition increases the relaxation of the initial elastic stress of the GaAsSb increases up to 23 %. In addition, the Sb composition influences the interband optical transitions such as the PL peak redshift and carrier lifetimes. C1 [Kim, Yeongho; Faleev, Nikolai; Honsberg, Christiana] Arizona State Univ, Sch Elect Comp & Energy Engn, Tempe, AZ 85287 USA. [Tang, Dinghao; Smith, David] Arizona State Univ, Dept Phys, Tempe, AZ 85287 USA. [Kuciauskas, Darius; Dippo, Patricia C.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Kim, Y (reprint author), Arizona State Univ, Sch Elect Comp & Energy Engn, Tempe, AZ 85287 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 978-1-4799-4398-2 PY 2014 BP 1056 EP 1058 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901060 ER PT J AU Marshall, AR Beard, MC Luther, JM AF Marshall, Ashley R. Beard, Matthew C. Luther, Joseph M. GP IEEE TI Multiple Exciton Generation Solar Cells: Effects of Nanocrystal Shape on Quantum Efficiency SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE Lead chalcogenides; multiple exciton generation; nanocrystals; photovoltaic cells ID MULTIEXCITON GENERATION; PBSE NANORODS; DOTS AB Semiconductor nanocrystals (NCs) have the ability to perform a process, termed multiple exciton generation (or MEG), which produces two electrons for every absorbed photon. This has been experimentally confirmed using ultrafast spectroscopic techniques for many semiconductor NC families. The shape of the NCs has been found to play an important role in the efficiency of MEG. Spherical PbSe NCs have been used to fabricate devices that exhibit greater than 100% quantum efficiencies, here we report on the use of NC morphologies and hybrid NC assemblies that can increase the power conversion efficiency in a device. C1 [Marshall, Ashley R.] Univ Colorado, Boulder, CO 80302 USA. [Marshall, Ashley R.; Beard, Matthew C.; Luther, Joseph M.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Marshall, AR (reprint author), Univ Colorado, Boulder, CO 80302 USA. OI BEARD, MATTHEW/0000-0002-2711-1355 NR 13 TC 1 Z9 1 U1 1 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1077 EP 1079 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901065 ER PT J AU Perl, EE McMahon, WE Bowers, JE Friedman, DJ AF Perl, Emmett E. McMahon, William E. Bowers, John E. Friedman, Daniel J. GP IEEE TI Material Selection and Fabrication Parameters for Antireflective Nanostructures Integrated with Multijunction Photovoltaics SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE biomimetics; III-V semiconductor materials; nanophotonics; optical films; photovoltaic cells; solar energy ID BROAD-BAND ANTIREFLECTION; SOLAR-CELLS; COATINGS; COVERGLASSES; INDEX AB Multijunction photovoltaic devices with four or more junctions require low reflection over a wavelength range that is nearly 50% wider than what is required for a triple-junction design. Antireflective nanostructures can drastically reduce reflection across this range; however careful design is necessary for integration with multijunction devices. In this work, we address the design trade-offs imposed by material availability by modeling absorption and reflection loss for various configurations. We find that the best performance is obtained using a hybrid design that combines antireflective nanostructures with a thin-film optical coating. Our models show that this configuration can increase transmitted power into the solar cell by 2.1% compared to the best standalone nanostructure configuration and 1.3% compared to an optimal thin-film antireflection coating. We also detail a fabrication process for integrating this hybrid design onto an active photovoltaic device. C1 [Perl, Emmett E.; Bowers, John E.] Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. [McMahon, William E.; Friedman, Daniel J.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Perl, EE (reprint author), Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. NR 24 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1174 EP 1179 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901088 ER PT J AU Sweet, CA Simon, JD Young, DL Ptak, AJ Packard, CE AF Sweet, Cassi A. Simon, John D. Young, David L. Ptak, Aaron J. Packard, Corinne E. GP IEEE TI Effect of Material Choice on Spalling Fracture Parameters to Exfoliate Thin PV Devices SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE device exfoliation; flexible films; GaAs; Ge photovoltaic cells; silicon ID YOUNGS MODULUS; GERMANIUM; FILMS; SI AB The use of fracture to exfoliate thin layers of semiconductor single crystals and single crystal-based devices has recently gained attention as an opportunity to create high-quality photovoltaic devices with reduced material consumption. A planar fracture that runs parallel to the material surface can be initiated by a sufficiently high tensile stress in an applied surface film in a process called spalling. In order to realize optimization of spall fracture depth accuracy and minimize material waste, the experimental parameters that affect fracture depth during the spalling of semiconductors must be better understood and tabulated. This work examines the application of spalling to common single-crystal photovoltaic materials including Ge, Si, and GaAs, to identify how the mechanical properties of the substrate and stressor layer, as well as the substrate thickness, impact the spalling depth. Experimental data for thin films spalled from (100) GaAs using a nickel stressor film are shown to be on trend with theoretical predictions, thus illustrating the utility of these calculations to better predict spall depth within the semiconductor. C1 [Sweet, Cassi A.; Packard, Corinne E.] Colorado Sch Mines, Golden, CO 80401 USA. [Simon, John D.; Young, David L.; Ptak, Aaron J.; Packard, Corinne E.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Sweet, CA (reprint author), Colorado Sch Mines, Golden, CO 80401 USA. RI Packard, Corinne/A-9606-2010 OI Packard, Corinne/0000-0002-5815-8586 NR 17 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1189 EP 1192 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901091 ER PT J AU Yang, BB Cruz-Campa, JL Haase, GS Tangyunyong, P Okandan, M Nielson, GN AF Yang, Benjamin B. Cruz-Campa, Jose L. Haase, Gaddi S. Tangyunyong, Paiboon Okandan, Murat Nielson, Gregory N. GP IEEE TI Stress Factor Assessment for Microsystems-Enabled Photovoltaics SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE microsystems enabled photovoltaics; reliability; reverse bias; thin film; silicon AB Microsystems-enabled photovoltaics (MEPV) utilizes microfabrication techniques to achieve various scaling advantages and attain high power density and efficiency. This paper describes accelerated test results for silicon MEPV that were used for development of a reliability model. MEPV has previously demonstrated good resilience to high reverse bias voltages. We further study this performance parameter by examining the degradation effects of prolonged reverse bias stress at voltage levels below breakdown. Light-induced degradation is examined through extended exposure to the output of a 405 nm laser diode. Samples are also subjected to moderate temperature cycling. The post-stress samples are evaluated through electrical tests and defect localization techniques. The results can be used to generate lifetime predictions and provide insights into design improvements for more reliable MEPV. C1 [Yang, Benjamin B.; Cruz-Campa, Jose L.; Haase, Gaddi S.; Tangyunyong, Paiboon; Okandan, Murat; Nielson, Gregory N.] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Yang, BB (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1305 EP 1309 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901119 ER PT J AU Marion, B Anderberg, A Deline, C del Cueto, J Muller, M Perrin, G Rodriguez, J Rummel, S Silverman, TJ Vignola, F Kessler, R Peterson, J Barkaszi, S Jacobs, M Riedel, N Pratt, L King, B AF Marion, Bill Anderberg, Allan Deline, Chris del Cueto, Joe Muller, Matt Perrin, Greg Rodriguez, Jose Rummel, Steve Silverman, Timothy J. Vignola, Frank Kessler, Rich Peterson, Josh Barkaszi, Stephen Jacobs, Mark Riedel, Nick Pratt, Larry King, Bruce GP IEEE TI New Data Set for Validating PV Module Performance Models SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE Data; irradiance; meteorological; photovoltaic module; user's manual AB A new publicly available data set was completed for use in validating models that estimate the performance of flat-plate photovoltaic (PV) modules. The data were collected for one-year periods at three climatically diverse locations (Cocoa, Florida; Eugene, Oregon; and Golden, Colorado) and for PV modules representing all technologies available in 2010 when the work began. The same makes and models of PV modules were tested at all locations and common data acquisition systems were used with calibrations performed at the National Renewable Energy Laboratory. For use in determining model parameters and coefficients, baseline and post-deployment measurements were performed indoors with solar simulators, including per the requirements of IEC 6185 3 Part 1: Irradiance and Temperature Performance Measurements and Power Ratings. Outdoors, the PV modules were characterized per the requirements of the Sandia array performance model. A user's manual describes the contents of the data set and how to access the data. C1 [Marion, Bill; Anderberg, Allan; Deline, Chris; del Cueto, Joe; Muller, Matt; Perrin, Greg; Rodriguez, Jose; Rummel, Steve; Silverman, Timothy J.] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Vignola, Frank; Kessler, Rich; Peterson, Josh] Univ Oregon, Eugene, OR 97403 USA. [Barkaszi, Stephen; Jacobs, Mark] Florida Solar Energy Ctr, Cocoa, FL USA. [Riedel, Nick; Pratt, Larry] CFV Solar Test Lab Inc, Albuquerque, NM USA. [King, Bruce] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Marion, B (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 9 TC 1 Z9 1 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1362 EP 1366 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901132 ER PT J AU Riley, D Fresquez, A AF Riley, Daniel Fresquez, Armando GP IEEE TI Determining the Effect of Temperature on Microinverter Inversion Efficiency SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE inverters; photovoltaic systems; power electronics; solar energy AB Sandia National Laboratories is working to develop a set of test procedures and characterization models which may be used to describe the performance of AC modules and serve as a basis of product comparison. However, in measuring the module/microinverter system output, it is difficult to determine the effects of correlated parameters on system performance. In particular, we have found that the module temperature and the inverter temperature are highly correlated when the system is operating, and thus it is difficult to separate their effects on system power output. In 2014, we have conducted temperature testing on microinverters and we will show that the effect of temperature on microinverter performance is sufficiently small to justify omitting it from the final characterization model for AC modules. C1 [Riley, Daniel; Fresquez, Armando] Sandia Natl Labs, Albuquerque, NM 87125 USA. RP Riley, D (reprint author), Sandia Natl Labs, Albuquerque, NM 87125 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1399 EP 1402 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901140 ER PT J AU Fthenakis, V Atia, AA Perez, M Florenzano, A Grageda, M Lofat, M Ushak, S Palma, R AF Fthenakis, Vasilis Atia, Adam A. Perez, Marc Florenzano, Alejandro Grageda, Mario Lofat, Marco Ushak, Svetlana Palma, Rodrigo GP IEEE TI Prospects for Photovoltaics in Sunny and Arid Regions: A Solar Grand Plan for Chile - Part I-Investigation of PV and Wind Penetration SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE Chile; desalination; energy; environment; mining; photovoltaic; deployment; wind ID ENERGY; US AB New markets for photovoltaics are being created in emerging economies where rich solar resources can produce solar electricity at affordable costs. A case in point is Chile, a country with great solar resources planning renewable energy deployment to address the needs of an expanding mining industry and a growing economy, while preserving the environment. The expansion of metal mining and smelting operations is constrained by the cost of electricity and the unavailability of water in northern Chile, offering an opportune synergy between photovoltaics and mining. Local estimates put the potential for solar electricity in the north interconnect at more than 200 GW, those of geothermal in the north and central interconnects from 3-16 GW, wind in the central interconnect from 5-40 GW, and small hydro and biomass in the south at 0.3 and 0.4 GW, correspondingly. These resources can supply not only the needs for sustainable development in Chile but can also produce electricity for neighboring countries. This paper examines the potential for immediate PV penetration in Chile's main electricity grids (SING and SIC) and options (i.e., curtailment, PV and wind combinations) that can increase such penetration. C1 [Fthenakis, Vasilis; Atia, Adam A.; Perez, Marc] Columbia Univ, Ctr Life Cycle Anal, New York, NY 10027 USA. [Fthenakis, Vasilis] Brookhaven Natl Lab, PV Sustainable Energy Dept, Upton, NY 11973 USA. [Florenzano, Alejandro; Lofat, Marco] Fdn Chile, Energy & Climate Change Area, Santiago, Chile. [Grageda, Mario; Ushak, Svetlana] Univ Antofagasta, Dept Chem Engn & Mineral Proc, Antofagasta 02800, Chile. [Grageda, Mario; Ushak, Svetlana] Univ Antofagasta, Ctr Adv Study Lithium & Ind Minerals CELiMIN, Antofagasta 02800, Chile. [Grageda, Mario; Ushak, Svetlana; Palma, Rodrigo] Univ Chile, Solar Energy Res Ctr SERC Chile, Santiago, Chile. RP Fthenakis, V (reprint author), Columbia Univ, Ctr Life Cycle Anal, 918 SW Mudd,500W 120th St, New York, NY 10027 USA. NR 18 TC 3 Z9 3 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1424 EP 1429 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901145 ER PT J AU Macknick, J Meldrum, J Nettles-Anderson, S Heath, G Miara, A AF Macknick, Jordan Meldrum, James Nettles-Anderson, Syndi Heath, Garvin Miara, Ariel GP IEEE TI Life cycle water use for photovoltaic electricity generation: a review and harmonization of literature estimates. SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE energy; photovoltaic systems; product life cycle management; water conservation; water resources AB This work provides consolidated estimates of water withdrawal and water consumption requirements for the full life cycle of photovoltaic (PV) systems, including component manufacturing, power plant construction, system operation, and decommissioning. Life cycle data were also collected for other types of electricity generating technologies for comparison purposes. Published estimates were gathered through a broad search of publicly available sources, screened for quality and relevance, and harmonized for methodological differences, when possible. Compared with other electricity generating technologies, the total life cycle water use for PV systems are lower than all other technologies except for wind technologies. C1 [Macknick, Jordan; Nettles-Anderson, Syndi; Heath, Garvin; Miara, Ariel] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Meldrum, James] Univ Colorado, Inst Behav Sci, Boulder, CO 80309 USA. RP Macknick, J (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. OI Meldrum, James/0000-0001-5250-3759 NR 5 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1458 EP 1460 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901151 ER PT J AU Pohl, A Johnson, J Sena, S Broderick, R Quiroz, J AF Pohl, Andrew Johnson, Jay Sena, Santiago Broderick, Robert Quiroz, Jimmy GP IEEE TI High-Resolution Residential Feeder Load Characterization and Variability Modelling SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE advanced inverter functionality; advanced grid functions; smart grid; voltage support; frequency support; photovoltaic systems; PV reliability AB Data from of a highly instrumented residential feeder in Ota City, Japan was used to determine 1 second load variability for the aggregation of 50, 100, 250, and 500 homes. The load variability is categorized by binning the data into seasons, weekdays vs. weekends, and time of day to create artificial sub-15-minute variability estimates for modeling dynamic load profiles. An autoregressive, AR (1) function along with a high pass filter was used to simulate the high resolution variability. The simulated data were validated against the original 1-second measured data. C1 [Pohl, Andrew; Johnson, Jay; Sena, Santiago; Broderick, Robert; Quiroz, Jimmy] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Pohl, A (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1471 EP 1475 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901154 ER PT J AU Robbins, SS Alleman, J Nelson, BP Webb, JD AF Robbins, Steven S. Alleman, Jeffl. Nelson, Brent P. Webb, Jeremy D. GP IEEE TI Kinesthetically connecting students to power produced by photovoitaic panels SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE teaching; photovoltaics; students; education; educators; power production; kinesthetics; K-12 education; engineering education; bike power; power engineering education AB Educating the public about photovoltaics as a power-producing technology has proven to be challenging. Qualities a person associates with power production like motion, sound, smoke, and vibration are not present with photovoltaics panels as there are none of the moving parts commonly associated with power production. To assist students in connecting with solar power, we help them feel the power by pedaling a bike to power a generator and then comparing their output to that of a nearby solar panel. This connects the student kinesthetically instead of through the abstraction of power represented by numbers and units. C1 [Robbins, Steven S.; Alleman, Jeffl.; Nelson, Brent P.; Webb, Jeremy D.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Robbins, SS (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1476 EP 1479 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901155 ER PT J AU Sigrin, B Sullivan, P Ibanez, E Margolis, R AF Sigrin, Ben Sullivan, Patrick Ibanez, Eduardo Margolis, Robert GP IEEE TI Representation of the Solar Capacity Value in the ReEDS Capacity Expansion Model SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE power system reliability; power system simulation; solar energy; solar power generation ID POWER AB An important emerging issue is the estimation of renewables' contributions to reliably meeting system demand, or their capacity value. While the capacity value of thermal generation can be estimated easily, assessment of wind and solar requires a more nuanced approach due to resource variability. Reliability-based methods, particularly, effective load-carrying capacity (ELCC), are considered to be the most robust techniques for addressing this resource variability. The Regional Energy Deployment System (ReEDS) capacity expansion model and other long-term electricity capacity planning models require an approach to estimating CV for generalized PV and system configurations with low computational and data requirements. In this paper we validate treatment of solar photovoltaic (PV) capacity value by ReEDS capacity expansion model by comparing model results to literature for a range of energy penetration levels. Results from the ReEDS model are found to compare well with both comparisons-despite not being resolved at an hourly scale. C1 [Sigrin, Ben; Sullivan, Patrick; Ibanez, Eduardo; Margolis, Robert] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Sigrin, B (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 16 TC 1 Z9 1 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1480 EP 1485 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901156 ER PT J AU Gonzalez, S Neely, J Ropp, M AF Gonzalez, Sigifredo Neely, Jason Ropp, Michael GP IEEE TI Effect of Non-unity Power Factor Operation in Photovoltaic Inverters Employing Grid Support Functions SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE advanced inverter functions; distributed energy resources (DER); non-unity; power factor AB The high penetration of utility-interconnected photovoltaic systems is causing heightened concern over the effect that variable renewable generation will have on the electric power system (EPS). These concerns have initiated the need to amend the utility interconnection standard to allow functionalities, so-called advanced inverter functions, to minimize the negative impact these variable distributed energy resources may have on EPS voltage and frequency. Unfortunately, advanced functions, in particular volt-VAr, will result in non-unity power factor (PF) operation[3]. The increased phase current results in additional conduction losses and switching losses in the inverter power electronics. These power losses have a direct impact on real power delivered to the grid at the point of common coupling (PCC) and an impact on inverter service life. This report provides analysis, simulation, and experimental evidence to investigate the effect of advanced inverter functions on non-unity PF operation. C1 [Gonzalez, Sigifredo; Neely, Jason] Sandia Natl Labs, Albuquerque, NM 87123 USA. [Ropp, Michael] Northern Plains Power Technol, Brookings, SD 57006 USA. RP Gonzalez, S (reprint author), Sandia Natl Labs, Albuquerque, NM 87123 USA. 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 978-1-4799-4398-2 PY 2014 BP 1498 EP 1503 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901159 ER PT J AU Aguirre, B Cruz-Campa, JL Pete, D Ordonez, R Michael, J Zubia, D AF Aguirre, Brandon Cruz-Campa, Jose Luis Pete, Douglas Ordonez, Rafael Michael, Joseph Zubia, David GP IEEE TI Method for Electrical-Structural Correlation in Isolated CdTe/CdS Islands SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE characterization; CdTe; defects; photovoltaic cells ID SOLAR-CELLS AB Industrial activity in the last three years has driven efficiencies of CdTe devices to above 20%. Most of the improvements in efficiency have come from enhancements in short circuit current, while the open circuit voltage (V-oc) has remained stagnant. High V-oc's have been attributed to longer lifetimes and correlated to defect reduction. Recent work has targeted the understanding of defects in polycrystalline films and their association to electrical performance. However, these approaches do not prevent the formation of defects and cannot deconvolute effects caused by the various types of defects. Our approach uses novel electrically isolated islands created by selective growth in masked substrates. This paper shows results on the growth and the characterization of micro and nano CdTe grains on indexed substrates. Several islands were characterized with SEM, EBSD, AFM and prepared for TEM analysis. Polycrystalline films with interconnected grains showed no difference regarding electrical activity among the grains. In contrast, isolated nano-islands had exponential or linear behaviors from grain to grain. The differences were determined by their own structure and not by surrounding CdTe grains. This technique can be advantageous to decouple defects and to understand the electrical-structural correlation in thin film solar cells. C1 [Aguirre, Brandon; Ordonez, Rafael; Zubia, David] Univ Texas El Paso, El Paso, TX 79968 USA. [Aguirre, Brandon; Cruz-Campa, Jose Luis; Michael, Joseph] Sandia Natl Labs, Albuquerque, NM 87123 USA. [Pete, Douglas] Ctr Integrated Nanotechnol, Albuquerque, NM 87123 USA. RP Aguirre, B (reprint author), Univ Texas El Paso, 500 W Univ Ave, El Paso, TX 79968 USA. 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 BN 978-1-4799-4398-2 PY 2014 BP 1585 EP 1588 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901179 ER PT J AU Burst, JM Rance, WL Meysing, DM Wolden, CA Metzger, WK Garner, SM Cimo, P Barnes, TM Gessert, TA Reese, MO AF Burst, J. M. Rance, W. L. Meysing, D. M. Wolden, C. A. Metzger, W. K. Garner, S. M. Cimo, P. Barnes, T. M. Gessert, T. A. Reese, M. O. GP IEEE TI Performance of Transparent Conductors on Flexible Glass and Plastic Substrates for Thin Film Photovoltaics SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE superstrate; transparent conductive oxides (TCOs); CdTe; flexible glass; PET ID ELECTRODES AB High-performance transparent conductive indium-tin-oxide (ITO) films on flexible glass have been flex-tested to 25-50k bend cycles without breakage, and with similar to 0.1% change in sheet resistance. In contrast, commercial ITO/PET samples undergo similar to 50-100% increase in sheet resistance in the same test, indicating that such coatings/substrates may not be acceptable for use in some products or fabrication procedures. The flexible glass substrate enables high-temperature processing, which facilitates the high performance of the coatings. Measurements of the volume resistivity and water vapor transmission rate (WVTR) indicate that Corning (R) Willow (R) Glass is suitable as a PV substrate material without need for barrier coatings or glass lamination. C1 [Burst, J. M.; Rance, W. L.; Metzger, W. K.; Barnes, T. M.; Gessert, T. A.; Reese, M. O.] NREL, Golden, CO 80401 USA. [Meysing, D. M.; Wolden, C. A.] Colorado Sch Mines, Golden, CO 80401 USA. [Garner, S. M.; Cimo, P.] Corning Inc, Corning, NY 14831 USA. RP Burst, JM (reprint author), NREL, Golden, CO 80401 USA. NR 12 TC 0 Z9 0 U1 1 U2 4 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1589 EP 1592 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901180 ER PT J AU Chavez, JJ Zhou, XW Ward, DK Cruz-Campa, JL Zubia, D AF Chavez, Jose J. Zhou, Xiaowang Ward, Donald K. Cruz-Campa, Jose L. Zubia, David GP IEEE TI A Molecular Dynamics Study on Defect Reduction in Thin Film Cd1-xZnxTe/CdS Solar Cells SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE thin film; misfit dislocation; photovoltaic cells; lattice mismatch AB Recently developed molecular dynamics models have been applied to study the formation of defects during growth of ZnTe-on-CdS multilayers. Our studies indicated that misfit dislocations are formed during growth, and the dislocation density can be reduced if the ZnTe layer is grown in a nano island configuration as opposed to a continuous film. These results highlight the use of molecular dynamics methods in providing valuable defect formation mechanism insight and guiding experimental efforts to produce high efficiency Cd1-xZnxTe solar cells. C1 [Chavez, Jose J.; Zubia, David] Univ Texas El Paso, El Paso, TX 79968 USA. [Zhou, Xiaowang; Ward, Donald K.] Sandia Natl Labs, Livermore, CA 94550 USA. [Cruz-Campa, Jose L.] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Chavez, JJ (reprint author), Univ Texas El Paso, El Paso, TX 79968 USA. NR 12 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1593 EP 1595 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901181 ER PT J AU Muzzillo, CP Mansfield, LM DeHart, C Bowers, K Reedy, RC To, B Noufi, R Ramanathan, K Anderson, TJ AF Muzzillo, Christopher P. Mansfield, Lorelle M. DeHart, Clay Bowers, Karen Reedy, Robert C. To, Bobby Noufi, Rommel Ramanathan, Kannan Anderson, Timothy J. GP IEEE TI The Effect of Ga Content on the Selenization of Co-evaporated CuGa/In Films and their Photovoltaic Performance SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE CIGS; co-evaporation; Cu(In,Ga)Se-2; gallium content; selenization; wide band gap ID SOLAR-CELLS; THIN-FILMS; METAL PRECURSORS; LAYERS AB Thin CuGa/In films with varying composition were deposited by co-evaporation and then selenized in situ with evaporated selenium. This growth process was interrupted at various stages to study the selenization behavior of metal precursors by GIXRD, SIMS, XRF, SEM, and EPMA. Precursor phase constitution and morphology were found to be similar to well-studied sputtered precursors. The phase evolution during selenization was also found to be similar to sputtered precursors, with greater Ga/(Ga+In) compositions requiring longer selenization time to completely form the chalcopyrite phase. Solar cells were fabricated with absorbers of varying composition and characterized by JV measurements. Relatively high Ga contents could be reached before photovoltaic performance degraded significantly. Champion power conversion efficiencies of 14.5, 14.4, and 12.2% were achieved with Ga/(Ga+In) similar to 30, 50, and 70%, respectively. C1 [Muzzillo, Christopher P.; Anderson, Timothy J.] Univ Florida, Gainesville, FL 32601 USA. [Muzzillo, Christopher P.; Mansfield, Lorelle M.; DeHart, Clay; Bowers, Karen; Reedy, Robert C.; To, Bobby; Ramanathan, Kannan] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Muzzillo, CP (reprint author), Univ Florida, Gainesville, FL 32601 USA. EM rommel.noufi@gmail.com NR 16 TC 3 Z9 3 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1649 EP 1654 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901193 ER PT J AU Nardone, M Albin, DS AF Nardone, Marco Albin, David S. GP IEEE TI Numerical Modeling of CdTe Cell Degradation SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE degradation; reliability; thin-film photovoltaics; defect kinetics; numerical modeling; semiconductor simulation ID SOLAR-CELLS; CADMIUM TELLURIDE; COPPER; SEMICONDUCTORS; STABILITY AB Time-dependent numerical modeling is employed in conjunction with experimental data to investigate degradation mechanisms in cadmium telluride (CdTe) solar cells. Two mechanisms are tested against the data: defect generation in the junction region caused by excess charge carriers, and back barrier increase due to ion migration. Junction effects result in stable J(sc) with significant losses in V-oc and F F, in accordance with typical data for the type of stress conditions considered here. The back barrier increase causes additional F F loss. The results suggest that neutral defect centers dissociate into positive/negative pairs near the main junction as degradation proceeds. C1 [Nardone, Marco] Bowling Green State Univ, Bowling Green, OH 43403 USA. [Albin, David S.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Nardone, M (reprint author), Bowling Green State Univ, Bowling Green, OH 43403 USA. NR 22 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1655 EP 1660 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901194 ER PT J AU Pankow, JW Steirer, KX Mansfield, LM Garris, RL Ramanathan, K Teeter, GR AF Pankow, Joel W. Steirer, K. Xerxes Mansfield, Lorelle M. Garris, Rebekah L. Ramanathan, Kannan Teeter, Glenn R. GP IEEE TI Band alignment of CBD deposited Zn(O,S)/Cu(In1-xGax)Se-2 interface SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE buffer layers; copper indium gallium diselenide; zinc oxysulfide AB Chemical bath deposition (CBD) Zn(O,S) buffer layers grown on Cu(In1-xGax)Se-2 (CIGS) thin films have recently surpassed CdS in high efficiency cells (20.9%). A critical component of a CIGS device is the buffer layer -the layer that is found between the absorber CIGS layer and the ZnO window layer. Although CBD CdS is an effective buffer layer and traditionally used for devices, it is not entirely effective for high bandgap absorber films. The Zn(O,S)/CIGS interface was studied by X-ray photoelectron spectroscopy to reveal the valence band offset (VBO) and conduction band offset (CBO) as -1.15 eV and 1.17 eV respectively. Band bending that accompanies junction formation is also characterized in both layers. C1 [Pankow, Joel W.; Steirer, K. Xerxes; Mansfield, Lorelle M.; Garris, Rebekah L.; Ramanathan, Kannan; Teeter, Glenn R.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Pankow, JW (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 9 TC 0 Z9 0 U1 2 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1670 EP 1673 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901197 ER PT J AU West, B Guthrey, H Chen, L Jeffries, A Bernardini, S Lai, B Maser, J Shafarman, W Al-Jasim, M Bertoni, M AF West, Bradley Guthrey, Harvey Chen, Lei Jeffries, April Bernardini, Simone Lai, Barry Maser, Joerg Shafarman, William Al-Jasim, Mowafak Bertoni, Mariana GP IEEE TI Electrical and Compositional Characterization of Gallium Grading in Cu(In,Ga)Se-2 Solar Cells SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE thin film; chalcopyrite; CIGS; band gap grading; synchrotron; x-ray fluorescence; EBIC AB Cu(In,Ga)Se-2 (CIGS) solar cells were characterized in cross section using electron beam induced current (EBIC) and synchrotron based x-ray fluorescence (XRF) measurements. Samples with varying gallium ratios and growth methods were compared. A correlation was observed between the compositional gallium grading profile from XRF and carrier activity seen in EBIC through the thickness of the CIGS layer. Samples with steep back grading showed carrier activity isolated near the CIGS/CdS interface, whereas a more uniform grading resulted in carrier activity seen throughout the absorber layer. 'Notch' grading showed only slight variation in EBIC profile compared to a back graded sample with similar gallium ratios. C1 [West, Bradley; Jeffries, April; Bernardini, Simone; Bertoni, Mariana] Arizona State Univ, Ira A Fulton Sch Engn, Tempe, AZ 85287 USA. [Guthrey, Harvey; Al-Jasim, Mowafak] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Chen, Lei; Shafarman, William] Univ Delaware, Inst Energy Convers, Newark, DE 19716 USA. [Lai, Barry; Maser, Joerg] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP West, B (reprint author), Arizona State Univ, Ira A Fulton Sch Engn, Tempe, AZ 85287 USA. NR 7 TC 0 Z9 0 U1 2 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1726 EP 1728 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638901210 ER PT J AU Kutes, Y Bosse, JL Aguirre, BA Cruz-Campa, JL Michael, J Zubia, D Spoerke, ED Huey, BD AF Kutes, Yasemin Bosse, James L. Aguirre, Brandon A. Cruz-Campa, Jose L. Michael, Joseph Zubia, David Spoerke, Erik D. Huey, Bryan D. GP IEEE TI Nanoscale Photovoltaic Performance in Micro/Nanopatterned CdTe-CdS Thin Film Solar Cells SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE AFM; conductive atomic force microscopy; CdTe; polycrystalline; micropatterned; grain boundary ID ATOMIC-FORCE MICROSCOPY AB A new approach to measure the local response of micropatterned CdTe based solar cells is presented. This method provides fast results with high spatial resolution and the ability to map short circuit current (I-sh), open circuit voltage (V-oc), maximum power, and fill factor. It is based on consecutive photoconductive atomic force microscopy (pcAFM) scans collected at different DC biases over the same area. An array of I-V response curves results based on spectra for any given location (image pixel) according to the photoresponse (pcAFM current contrast) as a function of the applied bias (image). Grains, grain boundaries and even twin boundaries are clearly resolved. C1 [Kutes, Yasemin; Bosse, James L.; Huey, Bryan D.] Univ Connecticut, Dept Mat Sci & Engn, Storrs, CT 06269 USA. [Aguirre, Brandon A.; Cruz-Campa, Jose L.] Sandia Natl Labs, MEMS Technol, Albuquerque, NM 87185 USA. [Spoerke, Erik D.] Sandia Natl Labs, Elect & Nanostruct Mat, Albuquerque, NM 87185 USA. [Aguirre, Brandon A.; Zubia, David] Univ Texas El Paso, Elect & Comp Engn, El Paso, TX 79902 USA. [Michael, Joseph] Sandia Natl Labs, Mat Characterizat & Performance, Albuquerque, NM 87185 USA. RP Kutes, Y (reprint author), Univ Connecticut, Dept Mat Sci & Engn, Storrs, CT 06269 USA. OI Huey, Bryan/0000-0002-1441-1180 NR 17 TC 0 Z9 0 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1903 EP 1907 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902032 ER PT J AU Chan, CK Ohta, T Kellogg, GL Mansfield, L Ramanathan, K Noufi, R AF Chan, Calvin K. Ohta, Taisuke Kellogg, Gary L. Mansfield, Lorelle Ramanathan, Kannan Noufi, Rommel GP IEEE TI Direct Observation of Grain Boundary PN Junction Potentials in CIGS Using Photoemission and Low Energy Electron Microscopy (PELEEM) SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE electron microscopy; photoelectron microscopy; photovoltaic cells; p-n junctions; spectroscopy; thin-film devices; II-VI semiconductor materials ID CU(IN,GA)SE-2 THIN-FILMS; SOLAR-CELL; TEXTURE AB Spectroscopic microscopies with chemical and electronic structure information have become important tools for understanding the complex structure-property-performance relationships of high performing Cu(In1-xGax)Se-2 (CIGS) photovoltaic materials and devices. Here, we describe the application of spectrally resolved photoemission and low-energy electron microscopy (spec-PELEEM) to CIGS. With the ability to map relative electric potentials with high fidelity, a large variation in the built-in pn junction potential was observed at CIGS grain boundaries. In any given 20 mu m region, the built-in voltage spanned the range from depletion (similar to 0.5 V) to inversion (similar to 1.4 V). These grain-to-grain variations could explain the electron collection efficiency of CIGS grain boundaries and devices. These results highlight the potential of spec-PELEEM to solve critical structure-property-performance issues facing compound thin-film materials. C1 [Chan, Calvin K.; Ohta, Taisuke; Kellogg, Gary L.] Sandia Natl Labs, Albuquerque, NM 87185 USA. [Ohta, Taisuke; Kellogg, Gary L.] Ctr Integrated Nanotechnol, Albuquerque, NM 87185 USA. [Mansfield, Lorelle; Ramanathan, Kannan; Noufi, Rommel] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Chan, CK (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. EM cchan@sandia.gov NR 18 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1908 EP 1911 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902033 ER PT J AU Farr, MG Stein, JS AF Farr, Michaela G. Stein, Joshua S. GP IEEE TI Spatial Variations in Temperature across a Photovoltaic Array SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE Photovoltaics; Cooling; Efficiency; Wind Speed AB The efficiency of any photovoltaic device is significantly affected by its operating temperature. It is therefore of great interest to the PV industry to have accurate models of module and array temperatures. Existing PV performance models generally assume that module temperature is a function of plane-of-array irradiance, ambient air temperature and wind speed AND that module temperatures across the array do not vary significantly enough to define. A comparison of two identical PV systems in different climates reveals that module temperatures across the array may in fact vary by several degrees based on the location relative to one another. This study describes the observed thermal patterns and evaluates the possible causes of these systematic variations. The following paper will present analysis of data gathered from two PV systems with identical setups located in Albuquerque NM and Orlando, Florida. C1 [Farr, Michaela G.; Stein, Joshua S.] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Farr, MG (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1921 EP 1926 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902036 ER PT J AU Freeman, J Whitmore, J Blair, N Dobos, AP AF Freeman, Janine Whitmore, Jonathan Blair, Nate Dobos, Aron P. GP IEEE TI Validation of Multiple Tools for Flat Plate Photovoltaic Modeling Against Measured Data SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE PV modeling error; PVsyst; PVWatts; PV*SOL; photovoltaic models; System Advisor Model; validation AB In this validation study, comprehensive analysis is performed on nine photovoltaic systems for which NREL could obtain detailed performance data and specifications, including three utility-scale systems and six commercial-scale systems. Multiple photovoltaic performance modeling tools were used to model these nine systems, and the error of each tool was analyzed compared to quality-controlled measured performance data. This study shows that, excluding identified outliers, all tools achieve annual errors within similar to 8% and hourly root mean squared errors less than 7% for all systems. Finally, the acceptability of this range of annual error is discussed with regard to irradiance data uncertainty and the use of default loss assumptions, and two avenues are proposed to reduce photovoltaic modeling error. C1 [Freeman, Janine; Whitmore, Jonathan; Blair, Nate; Dobos, Aron P.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Freeman, J (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 6 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1932 EP 1937 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902031 ER PT J AU Ngan, L Strevel, N Passow, K Panchula, AF Jordan, D AF Ngan, Lauren Strevel, Nicholas Passow, Kendra Panchula, Alex F. Jordan, Dirk GP IEEE TI Performance Characterization of Cadmium Telluride Modules Validated by Utility-Scale and Test Systems SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE CdTe; PV system performance; degradation rate; thin-film PV; PV energy modeling; photovoltaic cells AB Performance of First Solar CdTe modules deployed at both test and utility-scales are reviewed with characterization of the critical inputs to lifetime energy generation models. Systems reviewed in detail are a 15-month-old facility containing more than 30 MWdc, a 10-year-old 1.2 kWdc NREL test array, 19-year-old 600 Wdc NREL test array. A statistical analysis of an aggregate population of 600 MWdc of systems with up to 10 years of operation is undertaken. Data from the utility-scale installation are used to validate First Solar's energy prediction guidance and internal prediction software, Isis, which predicts energy to within +/-0.2% of measured. Plane-of-array irradiance and module temperature accuracy are also reviewed. The field test arrays at NREL exhibit long-term degradation rates ranging from -0.3%/yr to -0.5%/yr for First Solar CdTe modules. C1 [Ngan, Lauren; Strevel, Nicholas; Passow, Kendra; Panchula, Alex F.] First Solar, San Francisco, CA 94105 USA. [Jordan, Dirk] Natl Renewable Energy Lab, Golden, CO USA. RP Ngan, L (reprint author), First Solar, San Francisco, CA 94105 USA. NR 14 TC 0 Z9 0 U1 3 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1957 EP 1962 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902042 ER PT J AU Berghold, J Koch, S Frohmann, B Hacke, P Grunow, P AF Berghold, Juliane Koch, Simon Frohmann, Benny Hacke, Peter Grunow, Paul GP IEEE TI Properties of Encapsulation Materials and Their Relevance for Recent Field Failures SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE Long-term stability; encapsulation; PID; volume resistivity ID POTENTIAL-INDUCED DEGRADATION; SOLAR-CELLS AB Different encapsulation materials are investigated in terms of their PID-suppressing properties. In order to identify materials with a high potential for PID suppression, PID testing was conducted according to test protocols covering system voltages up to 1500 V and particularly long exposure times. Volume resistivity measurements at different temperatures and relative humidity are presented for the different encapsulation materials using "fresh" and aged samples to simulate relevant field conditions and to correlate with PID test results and field findings. C1 [Berghold, Juliane; Koch, Simon; Frohmann, Benny; Grunow, Paul] PI Photovolta Inst Berlin, D-10997 Berlin, Germany. [Hacke, Peter] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Berghold, J (reprint author), PI Photovolta Inst Berlin, Wrangelstr 100, D-10997 Berlin, Germany. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 1987 EP 1992 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902048 ER PT J AU Stein, JS McCaslin, S Hansen, CW Boyson, WE Robinson, CD AF Stein, Joshua S. McCaslin, Shawn Hansen, Clifford W. Boyson, William E. Robinson, Charles D. GP IEEE TI Measuring PV System Series Resistance Without Full IV Curves SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE photovoltaic cells; series resistance; predictive models; condition monitoring AB We present a method for measuring the series resistance of the PV module, string, or array that does not require measuring a full IV curve or meteorological data. Our method relies only on measurements of open circuit voltage and maximum power voltage and current, which can be readily obtained using standard PV monitoring equipment; measured short circuit current is not required. We validate the technique by adding fixed resistors to a PV circuit and demonstrating that the method can predict the added resistance. Relative prediction accuracy appears highest for smaller changes in resistance, with a systematic underestimation at larger resistances. Series resistance is shown to vary with irradiance levels with random errors below 1.5 % standard deviation. C1 [Stein, Joshua S.; Hansen, Clifford W.; Boyson, William E.; Robinson, Charles D.] Sandia Natl Labs, Albuquerque, NM 87185 USA. [McCaslin, Shawn] Draker, Burlington, VT 05401 USA. RP Stein, JS (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 6 TC 1 Z9 1 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2032 EP 2036 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902059 ER PT J AU Cale, J Palmintier, B Narang, D Carroll, K AF Cale, James Palmintier, Bryan Narang, Dave Carroll, Kevin GP IEEE TI Clustering Distribution Feeders in the Arizona Public Service Territory SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE clustering; k-mediods; k-means; principle components analysis AB This paper describes a methodology and approach used to perform clustering on distribution feeders within the service territory of Arizona Public Service (APS). This clustering process was performed in order for APS to characterize the types of feeders in their service territory and to provide a method of feeder classification to inform PV interconnection requirements in the future. The paper begins with a description of the history of clustering techniques for classifying distribution feeders. The method chosen for clustering APS feeders incorporates best practices for the clustering algorithm, stopping criteria, and variable selection. All routines were written in open-source scripting languages. Specific steps in the clustering process are described and applied to the feeders in the APS service territory showing results for each step. The paper concludes with a summary of the work. C1 [Cale, James; Palmintier, Bryan] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Narang, Dave; Carroll, Kevin] Arizona Publ Serv, Phoenix, AZ 85004 USA. RP Cale, J (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2076 EP 2081 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902068 ER PT J AU Williams, T Fuller, J Sclmeider, K Palmintier, B Lundstrom, B Chakraborty, S AF Williams, Tess Fuller, Jason Sclmeider, Kevin Palmintier, Bryan Lundstrom, Blake Chakraborty, Sudipta GP IEEE TI Examining System-Wide Impacts of Solar PV Control Systems with a Power Hardware-in-the-Loop Platform SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE power hardware-in-the-Ioop (PHIL); power system simulation; distributed power generation; solar power generation; testing; voltage control AB High penetration levels of distributed solar PV power generation may lead to adverse power quality impacts. Advanced inverter control schemes have the potential to mitigate many power quality concerns. However, interactions between local closed-loop controls may lead to unintended behavior in deployed systems. To study the performance of advanced control schemes in a detailed distribution system environment, a test platform has been developed that integrates Power Hardware-in-the-Loop (PHIL) with concurrent time-series electric distribution system simulation. In the test platform, GridLAB-D, a distribution system simulation tool, runs a detailed simulation of a distribution feeder in real-time mode at the Pacific Northwest National Laboratory (PNNL) and supplies power system parameters at a point of common coupling. At the National Renewable Energy Laboratory (NREL), a hardware inverter interacts with grid and PV simulators emulating an operational distribution system. The platform is described and initial test cases are presented. C1 [Williams, Tess; Fuller, Jason; Sclmeider, Kevin] Pacific NW Natl Lab, Richland, WA 99352 USA. [Palmintier, Bryan; Lundstrom, Blake; Chakraborty, Sudipta] Natl Renewable Energy Lab, Golden, CO USA. RP Williams, T (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. RI Fuller, Jason/C-9951-2014 OI Fuller, Jason/0000-0002-0462-0093 NR 18 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2082 EP 2087 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902069 ER PT J AU Baggu, M Ayyanar, R Narang, D AF Baggu, Murali Ayyanar, Raja Narang, David GP IEEE TI Feeder Model Validation and Simulation for High-Penetration Photovoltaic Deployment in the Arizona Public Service System SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE photovoltaic power systems; high-penetration PV; SCADA systems; data acquisition AB In an effort to better understand the impacts of high penetrations of photovoltaic (PV) generators on distribution systems, Arizona Public Service and its partners are implementing a multi-year project to develop the tools and knowledge base needed to safely and reliably integrate high penetrations of utility-and residential-scale PV. Building on the APS Community Power Project-Flagstaff Pilot, this project investigates the impact of PV on a representative feeder in northeast Flagstaff. To quantify and catalog the effects of the estimated 1.3 MW of PV that will be installed on the feeder (both smaller units at homes, as well as large, centrally located systems), high-speed weather and electrical data acquisition systems and digital "smart" meters were designed and installed to facilitate monitoring and to build and validate comprehensive, high-resolution models of the distribution system. These models are being developed to analyze the impacts of PV on distribution circuit-protection systems (including coordination and anti-islanding), predict voltage regulation and phase-balance issues, and develop voltlVAr control schemes. This paper expands upon a paper presented at the 2013 IEEE PV SC conference that described updated results from the data acquisition effort, newly developed graphical analysis tools, continued feeder modeling, utility-scale PV integration and performance, and continued model validation. This paper presents results from Phases 3 and 4 of the project. Specifically, the paper discusses feeder model evaluation and extended application for advanced scenario analysis, specifically feeder reconfiguration, smart-grid device interaction study, smart inverter grid, and support functionality. C1 [Baggu, Murali] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Ayyanar, Raja] Arizona State Univ, Phoenix, AZ 85287 USA. [Narang, David] Arizona Publ Serv, Phoenix, AZ 85072 USA. RP Baggu, M (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2088 EP 2093 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902070 ER PT J AU Seuss, L Reno, MJ Broderick, RJ Harley, RG AF Seuss, Lolm Reno, Matthew J. Broderick, Robert J. Harley, Ronald G. GP IEEE TI Evaluation of Reactive Power Control Capabilities of Residential PV in an Unbalanced Distribution Feeder SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE photovoltaic systems; reactive power control; voltage control; particle swarm optimization ID NETWORKS AB The use of residential PV grid-tie inverters to supply reactive power as a benefit to the distribution grid has been widely proposed, however, there is little insight into how much of a benefit can be achieved from this control under varying system operating points. This paper seeks to demonstrate the effectiveness of a linearized versus nonlinear reactive power dispatch solution on a highly unbalanced distribution feeder under differing load profiles, insolation levels, and penetration rates of PV in the feeder. The results are analyzed to determine the system operating points that are favorable to reactive power control and the overall effectiveness of each solution in realistic feeder states. C1 [Seuss, Lolm; Reno, Matthew J.; Harley, Ronald G.] Georgia Inst Technol, Atlanta, GA 30332 USA. [Reno, Matthew J.; Broderick, Robert J.] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Seuss, L (reprint author), Georgia Inst Technol, Atlanta, GA 30332 USA. 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 978-1-4799-4398-2 PY 2014 BP 2094 EP 2099 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902071 ER PT J AU Kempe, MD AF Kempe, Michael D. GP IEEE TI Evaluation of the Uncertainty in Accelerated Stress Testing SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE photovoltaic; durability; reliability; degradation; kinetics; service life prediction ID KINETICS AB Within the photovoltaic standards community there is a desire to create a standardized set of tests suitable for predicting service life. Ideally, one would want to link a set of exposure conditions to an equivalent number of years in the desired use location, or to predict the performance as a function of time. However, the inherent uncertainties in the acceleration factors lead to large uncertainties in the results. Here we use literature values of the chemical degradation kinetics for some polymeric components, and extrapolate these to the field use. We show that without a well documented understanding of the degradation mechanisms, uncertainties in the kinetics lead to very large uncertainties in the prediction of field performance even when the general degradation factors are understood. C1 [Kempe, Michael D.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Kempe, MD (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 26 TC 2 Z9 2 U1 1 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2170 EP 2175 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902086 ER PT J AU Miller, DC Deibert, SL Wohlgemuth, JH AF Miller, David C. Deibert, Scott L. Wohlgemuth, John. H. GP IEEE TI Trial-Run of a Junction-Box Attachment Test for Use in Photovoltaic Module Qualification SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE photovoltaics; module qualification; polymer; junction-box attachment test AB Engineering robust adhesion of the junction box (j-box) is a hurdle typically encountered by photovoltaic module manufacturers during product development and manufacturing process control. There are historical incidences of adverse effects (e.g., fires) caused when the j-box/adhesive/module system has failed in the field. The addition of a weight to the j-box during the "damp-heat," "thermal-cycle," or "creep" tests within the IEC qualification protocol is proposed to verify the basic robustness of the adhesion system. The details of the proposed test are described, in addition to a trial-run of the test procedure. The described experiments examine four moisture-cured silicones, four foam tapes, and a hot-melt adhesive used in conjunction with glass, KPE, THV, and TPE substrates. For the purpose of validating the experiment, j-boxes were adhered to a substrate, loaded with a prescribed weight, and then subjected to aging. The replicate mock-modules were aged in an environmental chamber (at 85 degrees C/85% relative humidity for 1000 hours; then 100 degrees C/<10% relative humidity for 200 hours) or fielded in Golden (CO), Miami (FL), and Phoenix (AZ) for one year. Attachment strength tests, including pluck and shear test geometries, were also performed on smaller component specimens. C1 [Miller, David C.; Deibert, Scott L.; Wohlgemuth, John. H.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Miller, DC (reprint author), Natl Renewable Energy Lab, 15013 Denver West Pkwy, Golden, CO 80401 USA. NR 15 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2182 EP 2187 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902088 ER PT J AU Wohlgemuth, J Kurtz, S Sample, T Kondo, M Yamamichi, M AF Wohlgemuth, John Kurtz, Sarah Sample, Tony Kondo, Michio Yamamichi, Masaaki GP IEEE TI Development of Comparative Tests of PV Modules by the International PV Module QA Task Force SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE reliability and durability of PV modules; accelerated stress testing; service life predictions AB The International Photovoltaic (PV) Module Quality Assurance Task Force (PVQAT) was created in 2011 to develop a rating system that provides comparative information about the relative durability of PV modules. The identification of accelerated stress tests that can provide such comparative information is seen as a major step toward being able to predict PV module service life. This paper provides details of the ongoing effort to determine the format of such an overall module rating system. C1 [Wohlgemuth, John; Kurtz, Sarah] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Sample, Tony] Commiss European Communities, JRC, I-21027 Ispra, Italy. [Kondo, Michio; Yamamichi, Masaaki] Natl Inst Adv Ind Sci & Technol, Tsukuba, Ibaraki, Japan. RP Wohlgemuth, J (reprint author), Natl Renewable Energy Lab, 15013 Denver West Pkwy, Golden, CO 80401 USA. NR 17 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2191 EP 2196 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902090 ER PT J AU Hor, A Luu, Q Fisher, J Luk, TS Baroughi, M May, PS Smith, S AF Hor, Amy Luu, QuocAnh Fisher, Jon Luk, Ting-Shan Baroughi, Mahdi May, P. Stanley Smith, Steve GP IEEE TI Surface Plasmon Polariton Enhanced Upconversion in Rare Earth Doped Nano Crystals on Plasmonic Substrates SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE Upconversion; plasmonics; sodium yttrium fluoride; erbium; ytterbium; thulium; surface plasmon polariton; spectral conversion AB Plasmonic enhancement of near infra-red to visible upconversion could potentially yield high-efficiency spectral converters for solar cells. We use spectroscopic imaging to investigate the intensity enhancement and modification of radiative rates of infra-red to visible upconversion from rare-earth doped nanoparticles (NaYF4:Yb:Er[Tm]) supported on substrates designed to support a surface plasmon polariton at frequencies which are near-resonant with the rare-earth sensitizer (Yb3+) absorption. Using spatially-resolved spectroscopic imaging, we directly observe a systematic enhancement in the efficiency of upconversion associated with the interaction of the co-doped nano-particles with the plasmonic substrates. Spectrally resolved reflectivity and time-resolved luminescence decay measurements support our interpretation. C1 [Hor, Amy; Luu, QuocAnh; Fisher, Jon; Smith, Steve] South Dakota Sch Mines & Technol, Nanosci & Nanoengn, Rapid City, SD 57701 USA. [Hor, Amy; Luu, QuocAnh; May, P. Stanley] Univ S Dakota, Dept Chem, Vermillion, SD 57069 USA. [Luk, Ting-Shan] Sandia Natl Labs, Ctr Integrated Nanotechnol, Albuquerque, NM 87123 USA. [Baroughi, Mahdi] S Dakota State Univ, Elect Engn & Comp Sci, Brookings, SD 57007 USA. RP Hor, A (reprint author), South Dakota Sch Mines & Technol, Nanosci & Nanoengn, Rapid City, SD 57701 USA. NR 15 TC 1 Z9 1 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2270 EP 2272 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902107 ER PT J AU Barnes, TM Rance, WL Burst, JM Reese, MO Meysing, DM Wolden, CA Mahabaduge, H Li, J Beach, JD Gessert, TA Garner, SM Cimo, P Metzger, WK AF Barnes, T. M. Rance, W. L. Burst, J. M. Reese, M. O. Meysing, D. M. Wolden, C. A. Mahabaduge, H. Li, J. Beach, J. D. Gessert, T. A. Garner, S. M. Cimo, Pat Metzger, W. K. GP IEEE TI High-Efficiency Flexible CdTe Superstrate Devices SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE CdTe; flexible electronics; photovoltaic cells; II-VI semiconductor materials AB Flexible, superstrate CdTe devices combine the advantages of a commercially demonstrated, low-cost manufacturing process with a lightweight, flexible form factor. Here, we present data on cell efficiencies greater than 16%, and the critical processing changes that have enabled recent efficiency increases. The devices in this study were made on Corning (R) Willow (R) Glass, which is a highly transparent, flexible, hermetic, and dimensionally stable substrate that can withstand high processing temperatures. To date, we have produced devices with several different combinations of front and back contacts on this glass and have found that it is compatible with most of our standard processing steps. One of our best devices to date has a certified efficiency of 16.2%, with a short-circuit current density (J(sc)) of 25.6 mA/cm(2), an open-circuit voltage of 820 mV, and a fill factor (FF) of 77.3%. The increased Jsc in this cell is due to an improved sputtered CdS:O deposition process, and the high FF is due to a co-evaporated ZnTe:Cu back contact. C1 [Barnes, T. M.; Rance, W. L.; Burst, J. M.; Reese, M. O.; Mahabaduge, H.; Gessert, T. A.; Metzger, W. K.] NREL, Golden, CO 80401 USA. [Meysing, D. M.; Wolden, C. A.; Li, J.; Beach, J. D.] Colorado Sch Mines, Golden, CO 80401 USA. [Garner, S. M.; Cimo, Pat] Corning Inc, Corning, NY 14831 USA. RP Barnes, TM (reprint author), NREL, Golden, CO 80401 USA. NR 12 TC 1 Z9 1 U1 2 U2 8 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2289 EP 2292 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902112 ER PT J AU Bob, B Li, JV Beall, C Carapella, J Dehart, C Yang, Y Repins, IL AF Bob, Brion Li, Jian V. Beall, Carolyn Carapella, Jeff Dehart, Clay Yang, Yang Repins, Ingrid L. GP IEEE TI Junction Formation and Interface Effects in CZTSe Solar Cells SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE Photovoltaic cells; space charge; interface phenomena; thin film devices; charge carrier processes AB The space charge distribution across the CZTSe/CdS heterojunction plays an important role in defining the recombination properties of Kesterite solar cells. We have conducted a study designed to manipulate the shape of the space charge region and trigger changes in the magnitude of interface recombination present in our devices. In doing so, we have observed the creation and removal of a secondary barrier in the conduction band of coevaporated CZTSe cells, and found that completed devices do not exhibit the changes in device properties that would be expected for devices dominated by interface recombination. C1 [Bob, Brion; Yang, Yang] Univ Calif Los Angeles, Dept Mat Sci & Engn, Los Angeles, CA 90095 USA. [Li, Jian V.; Beall, Carolyn; Carapella, Jeff; Dehart, Clay; Repins, Ingrid L.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Bob, B (reprint author), Univ Calif Los Angeles, Dept Mat Sci & Engn, Los Angeles, CA 90095 USA. RI Yang, Yang/A-2944-2011; Li, Jian/B-1627-2016 NR 14 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2299 EP 2303 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902114 ER PT J AU Duenow, JN Burst, JM Albin, DS Kuciauskas, D Johnston, SW Reedy, RC Duda, A DeHart, CM Metzger, WK AF Duenow, Joel N. Burst, James M. Albin, David S. Kuciauskas, Darius Johnston, Steven W. Reedy, Robert C. Duda, Anna DeHart, Clay M. Metzger, Wyatt K. GP IEEE TI CdTe Single-Crystal Heterojunction Photovoltaic Cells SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE photovoltaic cells; II-VI semiconductor materials; heterojunctions; current-voltage characteristics; cadmium compounds; solar energy ID SOLAR-CELLS AB Most recent gains in CdTe photovoltaic (PV) device efficiency have been in short-circuit current density (J(sc)) and fill factor (FF), rather than open-circuit voltage (V-oc). Because J(sc) is nearing its theoretical limit, further improvements in device efficiency will require increasing V-oc beyond 860 mV and increasing FF. V-oc and FF may be improved by increasing both the carrier concentration and minority-carrier lifetime of the CdTe. However, V-oc may be limited for other reasons, including Fermi-level pinning and surface recombination. In this study, we used doped CdTe single crystals to test whether higher carrier concentration and lifetime can overcome traditional V-oc barriers. In our work to date, we have fabricated heterojunction CdTe PV cells with V-oc up to 929 mV, FF of similar to 60%, and efficiencies of 10%. C1 [Duenow, Joel N.; Burst, James M.; Albin, David S.; Kuciauskas, Darius; Johnston, Steven W.; Reedy, Robert C.; Duda, Anna; DeHart, Clay M.; Metzger, Wyatt K.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Duenow, JN (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 13 TC 2 Z9 2 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2310 EP 2313 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902117 ER PT J AU Faulkner, BR Burst, JM Ohno, TR Perkins, CL To, B Gessert, TA AF Faulkner, B. R. Burst, J. M. Ohno, T. R. Perkins, C. L. To, B. Gessert, T. A. GP IEEE TI ZnTe:Cu Film Properties and Their Impact on CdS/CdTe Devices SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA ID SOLAR-CELLS AB A back contact containing a sputtered ZnTe:Cu interface layer can produce high-performing thin-film CdS/CdTe photovoltaic devices. We have found that small changes in ZnTe: Cu sputtering target fabrication processes affect the properties of the ZnTe: Cu films, which affect the performance of the resulting devices. Different target manufacturing techniques were investigated to study changes in ZnTe: Cu film properties and how they impact device performance. Compositional, optical, and electrical properties of films made from different target recipes were studied. It was found that the amount of oxygen in the targets and films is strongly linked to changes in material properties, especially in band tailing and optical bandgap. C1 [Faulkner, B. R.; Ohno, T. R.] Colorado Sch Mines, Golden, CO 80401 USA. [Burst, J. M.; Perkins, C. L.; To, B.; Gessert, T. A.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Faulkner, BR (reprint author), Colorado Sch Mines, Golden, CO 80401 USA. NR 10 TC 1 Z9 1 U1 2 U2 4 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2321 EP 2325 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902120 ER PT J AU Gessert, TA Duenow, JN Ward, S Geisz, JF To, B AF Gessert, Timothy A. Duenow, Joel N. Ward, Scott Geisz, John F. To, Bobby GP IEEE TI Analysis of ZnTe:Cu/Ti Contacts for Crystalline CdTe SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE Crystalline; CdTe; ZnTe:Cu; Ti; Contacts AB Recent studies of thin-film CdS/CdTe photovoltaic (PV) devices have suggested that significantly higher device performance will not be achieved unless both the net density (NA) and minority-carrier diffusion length (L-D) CdTe are simultaneously increased. Toward this goal, CdTe research at NREL currently includes studies that u crystalline CdTe or epitaxial CdTe layers to study changes in N and LD during the controlled incorporation of various intrinsic and extrinsic dopants. Unfortunately, for many of these studies, electrical contacts remain a limiting factor. In this paper we describe studies designed to enhance our understanding of the strengths and weaknesses of using the NREL ZnTe:Cu/Ti back contact process for the analysis of various cr samples. Because this contact has been shown to yield high performance and stability, we believe that understanding its on crystalline materials could advance our development of alternative contact processes that embody the potential fo higher performance. C1 [Gessert, Timothy A.; Duenow, Joel N.; Ward, Scott; Geisz, John F.; To, Bobby] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Gessert, TA (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 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 978-1-4799-4398-2 PY 2014 BP 2329 EP 2333 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902122 ER PT J AU Harvey, SP Perkins, C Young, M Moutinhol, H Wilson, S Teeter, G AF Harvey, Steven P. Perkins, Craig Young, Matthew Moutinhol, Helio Wilson, Samual Teeter, Glenn GP IEEE TI Heteroepitaxial Growth of CZTS SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE CZTS; CZTSe; MBE; epitaxy; epitaxial; surface preparation ID MOLECULAR-BEAM EPITAXY; ZNS; FILMS AB A summary of preparation methods of various substrates suitable for the epitaxial growth of copper zinc tin sulfide (CZTS) via molecular beam epitaxy (MBE) is presented. Substrates evaluated include silicon (various orientations), ZnS(110), Al2O3(0001), and gallium phosphide (GaP) (100). An overview of the techniques used to prepare a high-quality, epiready surface for each substrate is covered, with special attention given to the limitations presented by CZTS MBE, namely the stability of surfaces with respect to sulfur vapor. The quality of the substrates prior to growth has been assessed by in-situ reflection high-energy electron diffraction (RHEED) and photoemission techniques. ZnS epitaxial growth was attempted on all substrates because ZnS is viewed as a simplified model system for CZTS. ZnS epitaxial quality was assessed using RHEED during growth and via electron backscatter diffraction (EBSD) post-growth. C1 [Harvey, Steven P.; Perkins, Craig; Young, Matthew; Moutinhol, Helio; Teeter, Glenn] Natl Renewable Energy Lab, Golden, CO 80403 USA. [Wilson, Samual] Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. RP Harvey, SP (reprint author), Natl Renewable Energy Lab, Golden, CO 80403 USA. NR 15 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2338 EP 2342 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902124 ER PT J AU Mangan, NM Brandt, RE Steinmann, V Jaramillo, R Li, JV Poindexter, JR Hartman, K Sun, LZ Gordon, RG Buonassisi, T AF Mangan, Niall M. Brandt, Riley E. Steinmann, Vera Jaramillo, R. Li, Jian V. Poindexter, Jeremy R. Hartman, Katy Sun, Leizhi Gordon, Roy G. Buonassisi, Tonio GP IEEE TI A Path to 10% Efficiency for Tin Sulfide Devices SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE chalcogenide solar cells; device simulation; paths toward higher efficiency ID THIN-FILMS AB We preform device simulations of a tin sulfide (SnS) device stack using SCAPS to define a path to 10% efficient devices. We determine and constrain a baseline device model using recent experimental results on one of our 3.9% efficient cells. Through a multistep fitting process, we find a conduction band cliff of -0.2 eV between SnS and Zn(O, S) to be limiting the open circuit voltage (V-OC). To move towards a higher efficiency, we can optimize the buffer layer band alignment. Improvement of the SnS lifetime to > 1 ns is necessary to reach 10% efficiency. Additionally, absorber-buffer interface recombination must be suppressed, either by reducing recombination activity of defects or creating a strong inversion layer at the interface. C1 [Mangan, Niall M.; Brandt, Riley E.; Steinmann, Vera; Jaramillo, R.; Poindexter, Jeremy R.; Hartman, Katy; Buonassisi, Tonio] MIT, Cambridge, MA 02139 USA. [Li, Jian V.] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Sun, Leizhi; Gordon, Roy G.] Harvard Univ, Cambridge, MA 02138 USA. RP Mangan, NM (reprint author), MIT, 77 Massachusetts Ave, Cambridge, MA 02139 USA. RI Li, Jian/B-1627-2016; OI Mangan, Niall/0000-0002-3491-8341; Brandt, Riley/0000-0003-2785-552X NR 13 TC 2 Z9 2 U1 0 U2 4 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2373 EP 2378 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902131 ER PT J AU Moutinho, HR Young, M Harvey, S Jiang, CS Perkins, C Wilson, S Al-Jassim, MM Repins, IL Teeter, G AF Moutinho, H. R. Young, M. Harvey, S. Jiang, C-S. Perkins, C. Wilson, S. Al-Jassim, M. M. Repins, I. L. Teeter, G. GP IEEE TI Epitaxial Growth of CZTS on Si Substrates Investigated with Electron Backscatter Diffraction SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE CZTS; EBSD; epitaxial growth ID CU2ZNSNS4 THIN-FILMS; OPTICAL-PROPERTIES AB The objective of this work is to develop procedures for growing high-quality epitaxial Cu2ZnSnS4 thin films. We deposited our films by molecular beam epitaxy, with different growth parameters, on [100]- and [111]-oriented Si substrates. To study the growth of the films, we used electron backscatter diffraction. We found that, under the right conditions, we were able to grow epitaxial [111]-oriented CZTS films that had a common characteristic: the existence of two domains, both with the same orientation, but rotated by 60 degrees between each other. In this paper, we investigate the reliability of the EBSD analysis to study different domains in CZTS films, and correlate the film growth with deposition parameters, attempting to gain insight on the characteristics of the boundaries between the two domains. C1 [Moutinho, H. R.; Young, M.; Harvey, S.; Jiang, C-S.; Perkins, C.; Wilson, S.; Al-Jassim, M. M.; Repins, I. L.; Teeter, G.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Moutinho, HR (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI jiang, chun-sheng/F-7839-2012 NR 14 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2379 EP 2383 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902132 ER PT J AU Song, T Kanevce, A Sites, JR AF Song, Tao Kanevce, Ana Sites, James R. GP IEEE TI Exploring the Potential for High-Quality Epitaxial CdTe Solar Cells SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE device modeling; solar cells; epitaxial CdTe ID EFFICIENCY AB Traditional polycrystalline CdTe solar cell performance is limited by recombination at the grain boundaries, low carrier density (p), compensation from impurities, and a low minority carrier lifetime (tau). The maximum values for these critical parameters in polycrystalling devices are p < 10(15) cm(-3) and tau similar to 10 ns with open-circuit voltage (V-OC) similar to 900 mV and eta similar to 20%. Epitaxial CdTe with high-quality, low defect-density, and high carrier density, could yield a higher-efficiency PV device. Using numerical simulation, we investigate the combined effects of minority carrier lifetime tau (0.1 - 500 ns) and carrier density p (1x10(14) - 5x10(18) cm(-3)) on device performance, predicting obtainable performance of V-OC > 1100 mV and eta >25% for high tau and high p. While the V-OC is strongly affected by both p and tau, the short-circuit current (J(SC)) is mainly dependent on the lifetime tau and absorption losses in the front contact stack In addition, increasing the thickness of p-CdTe (varied from 0.5 - 20 mu m) at different tau (1 - 100 ns) shows an improvement in J(SC) due to increased long-wavelength photon collection and then saturates for thicker p-CdTe. In some cases, the cell performance is compromised by the presence of a significant back-contact barrier phi(b). The simulated results show that the cell performance is not strongly affected until phi(b) exceeds 0.4 eV. C1 [Song, Tao; Sites, James R.] Colorado State Univ, Dept Phys, Ft Collins, CO 80523 USA. [Kanevce, Ana] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Song, T (reprint author), Colorado State Univ, Dept Phys, Ft Collins, CO 80523 USA. NR 6 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2412 EP 2415 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902140 ER PT J AU Zakutayev, A Baranowski, LL Welch, AW Wolden, CA Toberer, ES AF Zakutayev, Andriy Baranowski, Lauryn L. Welch, Adam W. Wolden, Colin A. Toberer, Eric S. GP IEEE TI Comparison of Cu2SnS3 and CuSbS2 as Potential Solar Cell Absorbers SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE ternary copper metal sulfide; combinatorial sputtering; solar cell absorber AB Earth-abundant chalcogenide thin-film solar cells, in particular Cu2ZnSnS4 (CZTS), have recently attracted a lot of attention in the field of photovoltaics. Further increases in CZTS performance are challenging, in part because of defects caused by the chemical complexity of this quaternary material. Ternary copper chalcogenides, such as Cu2SnS3 and CuSbS2, are chemically simpler, but their performance is still lower than that of CZTS. Here, we compare the physical properties of the Cu-SnS and Cu-Sb-S material families using a high-throughput combinatorial approach, with particular focus on Cu2SnS3 and CuSbS2. We find that both materials have similar competing phases, but they differ significantly in terms of their structures, composition stability ranges, optical absorption, and electrical transport properties. The results of this study lead to the conclusion that CuSbS2, with lower conductivity and higher absorption, may be more promising for the development of Earth-abundant thin-film solar cells despite its layered structure and lower phase stability range. C1 [Zakutayev, Andriy; Baranowski, Lauryn L.; Welch, Adam W.; Toberer, Eric S.] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Baranowski, Lauryn L.; Welch, Adam W.; Wolden, Colin A.; Toberer, Eric S.] Colorado Sch Mines, Golden, CO 80401 USA. RP Zakutayev, A (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. OI Zakutayev, Andriy/0000-0002-3054-5525 NR 13 TC 2 Z9 2 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2436 EP 2438 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902146 ER PT J AU Zhou, XW Chavez, JJ Cruz-Campa, JL Zubia, D AF Zhou, Xiaowang Chavez, Jose Juan Cruz-Campa, Jose Luis Zubia, David GP IEEE TI Towards Model-Guided Defect Reduction in Cd1-xZnxTe/CdS Solar Cells: Development of Molecular Dynamics Models SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE CdTe; molecular dynamics; interatomic potential; photovoltaic cells; silicon ID TRANSMISSION ELECTRON-MICROSCOPY; TELLURIDE; CRYSTALS AB Cd1-xZnxTe/CdS solar cells are currently limited by material defects. While nano-structuring promises further defect reductions, the materials synthesis and characterization become more challenging. Molecular dynamics models capable of growth simulations enable defects to be explored without assumptions, and can therefore guide nanoscale experiments. Such models are difficult to develop, and are not routinely available in literature for semiconductor compounds. To fill this gap, we have developed growth simulation enabling Stillinger-Weber and bond-order potentials. These new models begin to enable molecular dynamics to be used to explore nano-structured Cd1-xZnxTe/CdS solar cells with reduced defects. C1 [Zhou, Xiaowang] Sandia Natl Labs, Livermore, CA 94550 USA. [Chavez, Jose Juan; Zubia, David] Univ Texas El Paso, El Paso, TX 79968 USA. [Cruz-Campa, Jose Luis] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Zhou, XW (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 19 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2439 EP 2442 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902147 ER PT J AU Ahn, S Rourke, D Nardes, AM van de Lagemaat, J Kopidakis, N Park, W AF Ahn, Sungmo Rourke, Devin Nardes, Alexandre M. van de Lagemaat, Jao Kopidakis, Nikos Park, Wounjhang GP IEEE TI Surface Plasmon Enhanced Infrared Absorption in the Sensitized Polymer Solar Cell SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE polymer solar cell; sensitizer; surface plasmon resonance; ternary polymer solar cell AB We have theoretically demonstrated an enhanced infrared absorption of the sensitizer in ternary polymer solar cell by introducing silver gratings at the back metal electrode. A combined model which incorporates the complex optical absorption profile and the electrical transport of the generated charge carriers was successfully developed. Using this model, we considered Si-PCPDTBT as an infrared sensitizer for P3HT:ICBA bulk heterojunction solar cells. A silver grating feature was optimized to produce a highly localized optical field inside the active polymer layer and enhance the infrared absorption of the sensitizer. Finally, an overall short-circuit current enhancement of about 40% is obtained theoretically. C1 [Ahn, Sungmo; Park, Wounjhang] Univ Colorado, Dept Elect Comp & Energy Engn, Boulder, CO 80309 USA. [Rourke, Devin] Univ Colorado, Dept Phys, Boulder, CO 80309 USA. [Nardes, Alexandre M.; van de Lagemaat, Jao; Kopidakis, Nikos] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Ahn, S (reprint author), Univ Colorado, Dept Elect Comp & Energy Engn, Boulder, CO 80309 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2554 EP 2556 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902174 ER PT J AU Nardes, AM Perkins, CL Graf, P Li, JV Shaheen, SE Ostrowski, D Watte, A Olson, DC Kopidakis, N AF Nardes, Alexandre M. Perkins, Craig L. Graf, Peter Li, Jian V. Shaheen, Sean E. Ostrowski, David Watte, Andrew Olson, Dana C. Kopidakis, Nikos GP IEEE TI Thermal annealing affects vertical morphology, doping and defect density in BHJ OPV devices SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE photovoltaic cells; defects; organic semiconductors; capacitance ID THIN-FILMS; CAPACITANCE TECHNIQUES; PHASE-SEPARATION; SURFACE-ENERGY; SOLAR-CELLS; POLYMER; EVOLUTION; BLEND AB We demonstrate that a post-annealing step results in enhanced open-circuit voltage (V-oc) and fill factor (FF) and lower reverse saturation current (J(s)) that consequently increases the power conversion efficiency (PCE) of organic bulk-heterojunction (BHJ) devices by about 40 % as a result of better contact formation, as typically assumed. Although true, we show that additional device properties are affected as well. We found that annealing induces vertical phase segregation and consequently the enrichment of donor and acceptor materials at the correct electrical contact. In addition, a de-doping process and a decrease in defect density also take place and are the major causes for device improvement after post-annealing the OPV devices. Implications for OPV basic research and manufacturing are discussed. C1 [Nardes, Alexandre M.; Perkins, Craig L.; Graf, Peter; Li, Jian V.; Ostrowski, David; Olson, Dana C.; Kopidakis, Nikos] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Shaheen, Sean E.] RASEI, Boulder, CO 80309 USA. [Shaheen, Sean E.; Ostrowski, David] Univ Colorado, Dept Elect Comp & Energy Engn, Boulder, CO 80309 USA. [Shaheen, Sean E.] Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Univ Denver, Dept Phys & Astron, Denver, CO 80208 USA. RP Nardes, AM (reprint author), Natl Renewable Energy Lab, 15013 Denver West Pkwy, Golden, CO 80401 USA. RI Li, Jian/B-1627-2016; Shaheen, Sean/M-7893-2013 NR 17 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2575 EP 2580 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902179 ER PT J AU Osterwald, CR Wanlass, MW Moriarty, T Steiner, MA Emery, KA AF Osterwald, C. R. Wanlass, M. W. Moriarty, T. Steiner, M. A. Emery, K. A. GP IEEE TI Empirical Procedure to Correct Concentrator Cell Efficiency Measurement Errors Caused by Unfiltered Xenon Flash Solar Simulators SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE efficiency measurements; multijunction solar cells; photovoltaic concentrator cells; solar simulators; spectral errors AB In this paper, we present an empirical error correction procedure for efficiency measurements of series-connected, multijunction concentrator solar cells. The error arises from the use of unfiltered xenon flash solar simulators with excess infrared radiation (wavelengths > 900 nm) into lowerbandgap subcells, and always results in an artificial increase of the measured efficiency. The efficacy of the procedure is demonstrated by comparing unfiltered efficiency data against other data from a flash simulator in which the spectral irradiance was properly adjusted. C1 [Osterwald, C. R.; Moriarty, T.; Steiner, M. A.; Emery, K. A.] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Wanlass, M. W.] Wanlass Consulting, Golden, CO 80403 USA. RP Osterwald, CR (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2616 EP 2619 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902188 ER PT J AU Hansen, CW Farr, M Pratt, L AF Hansen, Clifford W. Farr, Michaela Pratt, Larry GP IEEE TI Correcting Bias in Measured Module Temperature Coefficients SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE temperature coefficient; photovoltaic modules; testing AB Temperature coefficients for PV modules describe the change with temperature of current, voltage and power. Coefficients are commonly determined by linear regression using measured module output at fixed irradiance and varying temperatures. We compare temperature coefficients determined for the same modules from both outdoor and indoor measurements. We find systematic bias in the temperature coefficients for voltage and power, with values derived from indoor measurements consistently smaller in absolute value than values derived from outdoor testing during which the module temperature is measured as specified in IEC 61853-1. Our work suggests that the bias results from a corresponding bias in the estimated module temperature. However we have not identified an alternative arrangement of a few thermocouples that would result in consistent values for temperature coefficients from either indoor or outdoor measurements. C1 [Hansen, Clifford W.; Farr, Michaela] Sandia Natl Labs, Albuquerque, NM 87185 USA. [Pratt, Larry] CFV Solar Test Lab Inc, Albuquerque, NM 87106 USA. RP Hansen, CW (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2651 EP 2655 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902196 ER PT J AU Dooraghi, M Habte, A Reda, I Sengupta, M Gotseff, P Andreas, A AF Dooraghi, Mike Habte, Aron Reda, Ibrahim Sengupta, Manajit Gotseff, Peter Andreas, Afshin GP IEEE TI Quantifying the Impact of Incidence-Angle Dependence on Solar Radiometric Calibration SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE pyranometer; pyrheliometer; global horizontal irradiance; direct normal irradiance; diffuse irradiance; solar incident angle; MIDC; SRRL; BORCAL; responsivity AB Evaluating photovoltaic cells, modules, arrays, and system performance relies on accurate measurements of the solar radiation resources available for power conversion. Measuring solar resources accurately can lead to a reduction in the investment risks associated with installing and operating solar energy systems. The National Renewable Energy Laboratory's Solar Radiation Research Laboratory collects and disseminates solar irradiance data and provides calibrations of broadband radiometers that are traceable to the international standards. It is essential that radiometric data are traceable to the international system of units, e.g., through the World Radiometer Reference and World Infrared Standard Group. This paper demonstrates the importance and application of an existing approach that ultimately reduces the uncertainty of radiometric measurements. Almost all commercially available broadband radiometers use a single responsivity value that is generated at a 45 degrees solar zenith angle (incident angle) based on outdoor calibrations or transfers between radiometers inside integrating spheres or that responsivity is generated using normal incident radiation based on indoor calibrations using lamps and comparisons to reference radiometers to compute measured irradiance data. However, based on our experience and that of other experts in the radiometric science community, this method introduces increased uncertainty to the data. If a single responsivity value is used, the radiometer will overestimate or underestimate the irradiance data compared to the reference irradiance. This was demonstrated in Myers [1], Reda [2], and Reda et al. [3]. Further, by using responsivity as a function of solar zenith angle, the uncertainty for some instruments in the responsivity value can be reduced by as much as 50% compared to using a single responsivity calculated at 45 degrees [2, 3]. C1 [Dooraghi, Mike; Habte, Aron; Reda, Ibrahim; Sengupta, Manajit; Gotseff, Peter; Andreas, Afshin] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Dooraghi, M (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2662 EP 2667 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902198 ER PT J AU Bravo, RJ Robles, SA Muljadi, E AF Bravo, Richard J. Robles, Steven A. Muljadi, Eduard GP IEEE TI Assessing Solar PV Inverters' Anti-Islanding Protection SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE inverters anti-islanding; inverters with advanced features; anti-islanding protection; distributed generation; modeling distributed generation AB This paper provides an overview of the islanding potential of solar photovoltaic (PV) inverters. Solar PV inverters are typically known to have very effective protection mechanisms, but concerns have been raised as to whether or not they could maintain an island if load and generation were closely matched and/or if there were additional sources of distributed generation on a circuit. Also provided are the test results of multiple solar PV inverters operating in parallel during a variety of islanding scenarios. Additional tests included evaluating German inverters to investigate whether or not advanced features (such as volt/VAR controls and low-voltage ride-through) and load matching can compromise the solar PV inverters' anti-islanding protection. The testing was performed in Southern California Edison's Distributed Energy Resources Laboratory in Westminster, California. The results detailed here provide information that can be used to develop national standards for advanced features on solar PV inverters. Residential U.S. inverters have a nominal voltage of 240 V line to line, and German inverters are 230 V line to neutral. The frequency of the German inverters was adjusted to 60 Hz to reflect American standard practices. C1 [Bravo, Richard J.] Southern Calif Edisons Adv Technol Grp, San Francisco, CA 94143 USA. [Muljadi, Eduard] Calif State Univ Fresno, Fresno, CA 93740 USA. [Muljadi, Eduard] Natl Renewable Energy Lab, Golden, CO USA. RP Bravo, RJ (reprint author), Southern Calif Edisons Adv Technol Grp, San Francisco, CA 94143 USA. NR 1 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2668 EP 2671 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638902199 ER PT J AU Supplie, O Bruckner, S Romanyuk, O May, MM Doscher, H Kleinschmidt, P Stange, H Dobrich, A Hohn, C Lewerenz, HJ Grosse, F Hannappel, T AF Supplie, Oliver Brueckner, Sebastian Romanyuk, Oleksandr May, Matthias M. Doescher, Henning Kleinschmidt, Peter Stange, Helena Dobrich, Anja Hoehn, Christian Lewerenz, Hans-Joachim Grosse, Frank Hannappel, Thomas GP IEEE TI An experimental-theoretical atomic-scale study - in situ analysis of III-V on Si(100) growth for hybrid solar cells SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE III-V-on-silicon; in situ; MOVPE / MOCVD; interfaces ID ENERGY DENSITY; SURFACES AB We consider GaP/Si(100) as quasi-substrate for III-V-on-silicon growth targeting solar energy exploration in dual junction devices for both photovoltaics as well as photoelectrochemical tandem diodes with optimum bandgaps. We prepare Si(100) surfaces with majority domains of either type, grow thin GaP layers free of anti-phase disorder, find that abrupt Si-P interfaces are favored over abrupt Si-Ga interfaces and, finally, observe an RAS signal attributed to N incorporation in GaPN/Si(100). Combining in situ reflection anisotropy spectroscopy during metalorganic vapor phase epitaxy with UHV-based surface techniques and ab initio DFT calculations, we aim to understand the interface formation at the atomic scale. C1 [Supplie, Oliver; Brueckner, Sebastian; Doescher, Henning; Kleinschmidt, Peter; Dobrich, Anja; Hannappel, Thomas] Tech Univ Ilmenau, Inst Phys, FG Photovolta, D-98694 Ilmenau, Germany. [Supplie, Oliver; Brueckner, Sebastian; May, Matthias M.; Kleinschmidt, Peter; Stange, Helena; Dobrich, Anja; Hoehn, Christian; Hannappel, Thomas] Helmholtz Zentrum Berlin, Inst Solar Fuels, D-14109 Berlin, Germany. [Romanyuk, Oleksandr] Acad Sci Czech Republic, Inst Phys, CR-16200 Prague 6, Czech Republic. [Doescher, Henning] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Lewerenz, Hans-Joachim] CALTECH, Joint Ctr Artificial Photosynth, Pasadena, CA 91125 USA. [Grosse, Frank] Paul Drude Inst Festkorperelekt, D-10117 Berlin, Germany. RP Supplie, O (reprint author), Tech Univ Ilmenau, Inst Phys, FG Photovolta, D-98694 Ilmenau, Germany. RI Stange, Helena/C-1845-2016; May, Matthias/H-8552-2013 OI Stange, Helena/0000-0001-6416-6884; May, Matthias/0000-0002-1252-806X NR 15 TC 0 Z9 0 U1 0 U2 4 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2797 EP 2799 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903010 ER PT J AU Dobos, AP MacAlpine, SM AF Dobos, Aron P. MacAlpine, Sara M. GP IEEE TI Procedure for Applying IEC-61853 Test Data to a Single Diode Model SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE IEC-61853; performance modeling; photovoltaic module model; single diode model; thin film model AB Accurate modeling of a photovoltaic module's current-voltage characteristic is essential to predicting the generated power at any operating condition. This paper presents an approach to improve prediction accuracy of current single diode models by leveraging test data collected according to the IEC-61853 standard. Modified auxiliary diode model equations are proposed, along with a procedure to automatically calculate the additional model parameters from test data. The extended single diode model indicates potential to reduce average maximum power point prediction error across a wide temperature and irradiance range by about 75 % relative to the baseline five parameter model. C1 [Dobos, Aron P.; MacAlpine, Sara M.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Dobos, AP (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. 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 978-1-4799-4398-2 PY 2014 BP 2846 EP 2849 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903022 ER PT J AU Zaharatos, B Campanelli, M Hansen, C Emery, K Tenorio, L AF Zaharatos, Brian Campanelli, Mark Hansen, Clifford Emery, Keith Tenorio, Luis GP IEEE TI Likelihood Methods for Single-Diode Model Parameter Estimation from Noisy I-V Curve Data SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE likelihood function; maximum likelihood estimator; noise model; parameter estimation; single-diode model ID PERFORMANCE AB Characterizing photovoltaic (PV) device performance is important for the growth of the PV industry. Performance is often characterized by a set of key parameters for the PV device in question: open-circuit voltage, short-circuit current, and maximum power. For a wide range of devices, the key performance parameters are a function of the parameters of a single-diode circuit model. In this paper, we present a statistical model for current-voltage-irradiance data of a PV device using a five-parameter single-diode model. The goal is to estimate the single-diode model parameters and key performance parameters with quantified uncertainty. Specifically, we find maximum likelihood estimates, quantify uncertainty via confidence intervals for the model and key performance parameters, and explore two important statistical properties of this model-identifiability and estimability. C1 [Zaharatos, Brian; Tenorio, Luis] Colorado Sch Mines, Golden, CO 80401 USA. [Campanelli, Mark; Emery, Keith] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Hansen, Clifford] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Zaharatos, B (reprint author), Colorado Sch Mines, Golden, CO 80401 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2850 EP 2855 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903023 ER PT J AU Ulbrich, C Kurtz, S Jordan, D Gorig, M Gerber, A Rau, U AF Ulbrich, Carolin Kurtz, Sarah Jordan, Dirk Goerig, Marzella Gerber, Andreas Rau, Uwe GP IEEE TI Direct Analysis of the Current-Voltage Curves of Outdoor-Degrading Modules SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE CdTe; degradation; monitoring; IV curve; photovoltaic modules; diode ideality ID SILICON SOLAR-CELLS; PERFORMANCE; MODEL AB We apply a phenomenological four-parameter equation to fit and analyze regularly measured current density-voltage JV curves of various technologies. The physically meaningful four parameters, short-circuit current density J(sc), open-circuit voltage V-oc, and differential resistances R-sc and R-oc are determined for one-week data intervals of an exemplarily chosen CdTe module during 2.5 years of outdoor operation. For the chosen thin-film module, the fill factor FF degradation outweighs the degradation of J(sc) and V-oc. Interestingly, the V-oc vs. log(J(sc)) curves of the module at low irradiation unveil an increasing influence of a double-exponential diode behavior. The data hint at an increasing voltage-dependent charge-carrier collection in CdTe. C1 [Ulbrich, Carolin; Goerig, Marzella; Gerber, Andreas; Rau, Uwe] Forschungszentrum Julich, Photovolta IEK5, D-52428 Julich, Germany. [Kurtz, Sarah; Jordan, Dirk] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Ulbrich, C (reprint author), Forschungszentrum Julich, Photovolta IEK5, D-52428 Julich, Germany. NR 14 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2856 EP 2861 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903024 ER PT J AU Ward, JS Egaas, B Noufi, R Contreras, M Ramanathan, K Osterwald, C Emery, K AF Ward, James S. Egaas, Brian Noufi, Rommel Contreras, Miguel Ramanathan, Kannan Osterwald, Carl Emery, Keith GP IEEE TI Cu(In,Ga)Se-2 Solar Cells Measured under Low Flux Optical Concentration SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA AB The behavior of Cu(In,Ga)Se-2 (CIGS) solar cells under low flux concentration is being investigated for two complementary reasons. First, pairing photovoltaic devices with inexpensive low flux optical concentration elements can be a rational pathway towards systems that yield a low levelized cost of electricity (LCE). Second, characterization of photovoltaic films under elevated flux levels can be an effective tool for helping to understand the nature of recombination and other parasitic loss mechanisms in these device structures. In this paper we report on a CIGS device that achieved a record efficiency of 23.3% at 14.7 Suns optical concentration and outline a strategy for future work intended to use characterization of devices under elevated flux to explore the physical mechanisms currently limiting the performance of CI(G)S solar cells. C1 [Ward, James S.; Egaas, Brian; Noufi, Rommel; Contreras, Miguel; Ramanathan, Kannan; Osterwald, Carl; Emery, Keith] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Ward, JS (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. 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 978-1-4799-4398-2 PY 2014 BP 2934 EP 2937 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903040 ER PT J AU Jensen, MA Hofstetter, J Fenning, DP Morishige, AE Coletti, G Lai, B Buonassisi, T AF Jensen, Mallory Ann Hofstetter, Jasmin Fenning, David P. Morishige, Ashley E. Coletti, Gianluca Lai, Barry Buonassisi, Tonio GP IEEE TI The Distribution of Chromium in Multicrystalline Silicon SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE chromium; synchrotron-based micro-X-ray fluorescence; photovoltaics; precipitation; multicrystalline silicon AB Metallic impurities such as chromium form Shockley-Read-Hall recombination centers in both p- and n-type silicon, limiting minority-carrier lifetimes and reducing solar cell efficiencies. Much effort has been focused on understanding the distribution and evolution of iron-silicide precipitates during phosphorous diffusion gettering. As interest in n-type silicon grows, other impurities including chromium require similar attention. We elucidate the spatial distribution of chromium-rich particles in intentionally-contaminated multicrystalline silicon using micro-X-ray fluorescence. We find that observed chromium-rich particles are, on average, smaller and in lower density than observed iron-rich particles, likely because of the lower Cr solubility and diffusivity compared to Fe. These experimental observations could enable more accurate modeling of the behavior of chromium in silicon. C1 [Jensen, Mallory Ann; Hofstetter, Jasmin; Fenning, David P.; Morishige, Ashley E.; Buonassisi, Tonio] MIT, Cambridge, MA 02139 USA. [Coletti, Gianluca] ECN Solar Energy, NL-1755 LE Petten, Netherlands. [Lai, Barry] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Jensen, MA (reprint author), MIT, 77 Massachusetts Ave, Cambridge, MA 02139 USA. OI Morishige, Ashley/0000-0001-9352-8741 NR 12 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2938 EP 2940 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903041 ER PT J AU Castellanos, S Hofstetter, J Kivambe, M Rinio, M Lai, B Buonassisi, T AF Castellanos, Sergio Hofstetter, Jasmin Kivambe, Maulid Rinio, Markus Lai, Barry Buonassisi, Tonio GP IEEE TI Inferring Dislocation Recombination Strength in Multicrystalline Silicon via Etch Pit Geometry Analysis SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE cluster; dislocations; etch pit; multicrystalline; recombination activity; recombination strength; silicon; solar ID GRAIN-BOUNDARIES AB Dislocations limit solar cell performance by decreasing minority carrier diffusion length, leading to inefficient charge collection at the device contacts [1]. However, studies have shown that the recombination strength of dislocation clusters within millimeters away from each other can vary by orders of magnitude [2]. In this contribution, we present correlations between dislocation microstructure and recombination activity levels which span close to two orders of magnitude. We discuss a general trend observed: higher dislocation recombination activity appears to be correlated with a higher degree of impurity decoration, and a higher degree of disorder in the spatial distribution of etch pits. We present an approach to quantify the degree of disorder of dislocation clusters. Based on our observations, we hypothesize that the recombination activity of different dislocation clusters can be predicted by visual inspection of the etch pit distribution and geometry. C1 [Castellanos, Sergio; Hofstetter, Jasmin; Kivambe, Maulid; Buonassisi, Tonio] MIT, Cambridge, MA 02139 USA. [Rinio, Markus] Karlstad Univ, SE-65188 Karlstad, Sweden. [Lai, Barry] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Castellanos, S (reprint author), MIT, 77 Massachusetts Ave, Cambridge, MA 02139 USA. NR 8 TC 0 Z9 0 U1 2 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 2957 EP 2959 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903045 ER PT J AU Morishige, AE Fenning, DP Hofstetter, J Jensen, MA Ramanathan, S Wang, CL Lai, B Buonassisi, T AF Morishige, Ashley E. Fenning, David P. Hofstetter, Jasmin Jensen, Mallory Ann Ramanathan, Saptharishi Wang, Chenlei Lai, Barry Buonassisi, Tonio GP IEEE TI Elucidating and Engineering Recombination-Active Metal-Rich Precipitates in n-type Multicrystalline Silicon SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE gettering; lifetime; n-type; photovoltaics; silicon ID SOLAR-CELLS; DIFFUSION; SI AB Solar cells based on n-type upgraded metallurgical grade multicrystalline silicon (mc-Si) substrates may be a promising path for reducing the cost per watt of photovoltaics. The detrimental effect of metal point defects in both n- and p-type silicon is known, but the recombination activity of metal-silicide precipitates, especially in n-type mc-Si, is still not well established, impeding modeling and process optimization efforts. In this contribution, we provide a rationale for why metal-rich precipitates may limit minority-carrier lifetime in n-type mc-Si, in contrast to as-grown p-type mc-Si, which is dominated by metal point defects. Using mu-XRF, we identify metal-rich precipitates along a recombination active grain boundary in the low-lifetime "red zone" region of n-type wafers from a corner brick. To reduce the concentration of precipitated metals, we phosphorus-diffuse the wafers. Grain boundaries remain recombination active, which may be attributed to incomplete gettering of point defects and dissolution of recombination-active metal-rich precipitates. C1 [Morishige, Ashley E.; Fenning, David P.; Hofstetter, Jasmin; Jensen, Mallory Ann; Buonassisi, Tonio] MIT, Cambridge, MA 02139 USA. [Ramanathan, Saptharishi; Wang, Chenlei] Sunpreme Inc, Sunnyvale, CA 94085 USA. [Lai, Barry] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Morishige, AE (reprint author), MIT, 77 Massachusetts Ave, Cambridge, MA 02139 USA. OI Morishige, Ashley/0000-0001-9352-8741 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 978-1-4799-4398-2 PY 2014 BP 3004 EP 3010 PG 7 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903057 ER PT J AU McConnell, S Wang, Z Balog, RS Johnson, J AF McConnell, Stephen Wang, Zhan Balog, Robert S. Johnson, Jay GP IEEE TI Evaluation Method for Arc Fault Detection Algorithms SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE arc discharges; detection algorithms; photovoltaic systems AB Many methods have been proposed to detect arc faults within photovoltaic systems. However, because of the dearth of data surrounding arcs that actually occur in commercial or residential PV systems, a sound method is necessary to systematically check for the effectiveness of algorithms claiming the ability to detect PV arc faults. This method should include data representing actual background PV system noise and seek to quantify the limits of the detection capability for the algorithms of interest. C1 [McConnell, Stephen; Wang, Zhan; Balog, Robert S.] Texas A&M Univ, College Stn, TX 77840 USA. [Johnson, Jay] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP McConnell, S (reprint author), Texas A&M Univ, College Stn, TX 77840 USA. NR 6 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 3201 EP 3206 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903102 ER PT J AU Wang, Z McConnell, S Balog, RS Johnson, J AF Wang, Zhan McConnell, Stephen Balog, Robert S. Johnson, Jay GP IEEE TI Arc Fault Signal Detection - Fourier Transformation vs. Wavelet Decomposition Techniques using Synthesized Data SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE arc fault detection; inverter noise; Fourier transform; wavelet transform; filter banks ID FREQUENCY; DOMAIN AB Arc faults are a significant reliability and safety concern for photovoltaic (PV) systems and can cause intermittent operation, system failure, electrical shock hazard, and even fire. Further, arc faults in deployed systems are seemingly random and challenging to faithfully create experimentally in the laboratory, which makes the study of arc fault signature detection difficult. While it may seem trivial to simply record arcing signatures from real-world system, an obstacle in capturing these arc signals is that arc faults in the PV systems do not happen predictably, and depending on the location of the sensors relative to the arc location, may contribute a negligible portion to the magnitude of the sensed current or voltage waveform. The high-frequency content of the arc requires fast sampling, long memory, and fast processing to acquire, store, and analyze the waveforms; this adds substantial balance-of-system cost when considering widespread deployment of arc fault detectors in PV applications. In this paper, we study the performance of the fast Fourier transform arc detection method compared to the wavelet decomposition method by using synthetic waveforms. These waveforms are created by combining measured waveforms of normal background noise from inverters in DC PV arrays along with waveforms of arcing events. Using this technique allows the ratio of amplitudes are varied. Combining these separate waveforms in various amplitude proportions enables creation of test signals for the study of detection algorithm efficacy. It will be shown that the wavelet transformation technique produce more easily recognized detection results and can perform this detection using a much lower sampling rate than what is required for the fast Fourier transform C1 [Wang, Zhan; McConnell, Stephen; Balog, Robert S.] Texas A&M Univ, College Stn, TX 77843 USA. [Johnson, Jay] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Wang, Z (reprint author), Texas A&M Univ, College Stn, TX 77843 USA. NR 31 TC 4 Z9 4 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 3239 EP 3244 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903110 ER PT J AU Burst, JM Albin, DS Duenow, JN Reese, MO Farrell, SB Kuciauskas, D Metzger, WK AF Burst, J. M. Albin, D. S. Duenow, J. N. Reese, M. O. Farrell, S. B. Kuciauskas, D. Metzger, W. K. GP IEEE TI Advances in Control of Doping and Lifetime in Single-Crystal and Polycrystalline CdTe SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE doping; carrier lifetime; photovoltaic cells; CdTe AB We demonstrate the controlled alteration of bulk defects in CdTe single crystals and polycrystalline films to achieve high bulk minority-carrier lifetime and p-type doping. Low-temperature photoluminescence measurements confirm that bulk defect chemistry is altered by inserting intentional extrinsic dopants. Group I dopants such as copper display a tradeoff where increased doping decreases lifetime. By incorporating a Group V dopant source such as phosphorus, bulk lifetime values of 20-40 ns with acceptor density values of 0.7-1.0x10(16) cm(-3) are obtained in single and polycrystalline CdTe crystals. This exceptional combination of long lifetime and high p-type doping in a manufacturable material provides a path to increase open-circuit voltage, fill factor, and efficiency in CdTe photovoltaic devices. C1 [Burst, J. M.; Albin, D. S.; Duenow, J. N.; Reese, M. O.; Farrell, S. B.; Kuciauskas, D.; Metzger, W. K.] Natl Renewable Energy Lab, Natl Ctr Photovolta, Golden, CO 80401 USA. RP Burst, JM (reprint author), Natl Renewable Energy Lab, Natl Ctr Photovolta, Golden, CO 80401 USA. NR 5 TC 1 Z9 1 U1 0 U2 11 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 3258 EP 3260 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903115 ER PT J AU Colegrove, E Stafford, B Gao, W Gessert, T Sivananthan, S AF Colegrove, Eric Stafford, Brian Gao, Wei Gessert, Tim Sivananthan, Siva GP IEEE TI Arsenic Doped Heteroepitaxial CdTe by MBE for Applications in Thin-Film Photovoltaics SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE CdTe; MBE; heteroepitaxy; arsenic doping ID DEFECT LEVEL; HYDROGEN AB Open circuit voltages in CdTe based solar photovoltaics can be improved through increasing the acceptor carrier concentration in the absorber. Arsenic doped heteroepitaxial CdTe layers deposited by MBE are investigated as a means to understand the viability of arsenic as an alternative dopant source without the complication of polycrystalline grain boundaries or high temperature deposition processes. Crystal quality, thickness, and minority carrier lifetimes are correlated with arsenic incorporation and p-type carrier concentrations for both doped and undoped films. Films with carrier concentrations greater than 1013 cm(-3) have been produced using both an arsenic cracker source and a Cd3As2 effusion source though incorporation differs drastically between these two. As previous work has found, arsenic incorporation is shown to degrade crystal quality. Despite the lower crystal quality, minority carrier lifetimes greater than 1 ns have been achieved in samples with high carrier concentrations when the Cd3As2 source is used suggesting the benefit of cadmium overpressure. While the feasibility of arsenic doping during high temperature CdTe deposition processes is still not known, arsenic is shown to be a viable dopant source for continued investigation of heteroepitaxial model systems. C1 [Colegrove, Eric; Stafford, Brian; Gao, Wei; Sivananthan, Siva] Univ Illinois, Microphys Lab, Chicago, IL 60607 USA. [Gessert, Tim] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Colegrove, E (reprint author), Univ Illinois, Microphys Lab, Chicago, IL 60607 USA. NR 20 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 3261 EP 3265 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903116 ER PT J AU Stokes, A Gorman, B Diercks, D Egaas, B Al-Jassim, M AF Stokes, Adam Gorman, Brian Diercks, Dave Egaas, Brian Al-Jassim, Mowafak GP IEEE TI Direct Evidence of a Cu(In,Ga)(3)Se-5 Phase in a Bulk, High-Efficiency Cu(In,Ga)Se-2 Device Using Atom Probe Tomography SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE chalcopyrite; photovoltaic cells; Cu depletion; ordered vacancy compounds (OVC); atom probe tomography; transmission electron microscopy ID CUINSE2; FILMS; SURFACE AB This paper will descuss the findings of an ordered vacancy compound (OVC) phase, Cu(In,Ga)(3)Se-5 (135 phase), that exists deep into the bulk of a high-efficiency CIGSe absorber as determined by atom probe tomography (APT). To date, literature has shown that absorbers grown with the three-step process exhibit the 135 phase only within the first few nanometers from the CdS/CIGSe interface. In this contribution, we have found a small volume (100 nm x 100 nm x 300 nm) of the 135 phase to exist about 400 nm into the absorber. The paper will discuss possibly why the phase was found by APT and not by other characterization techniques. C1 [Stokes, Adam; Gorman, Brian; Diercks, Dave] Colorado Sch Mines, Golden, CO 80401 USA. [Stokes, Adam; Egaas, Brian; Al-Jassim, Mowafak] Natl Renewable Energy Lab, Golden, CO USA. RP Stokes, A (reprint author), Colorado Sch Mines, Golden, CO 80401 USA. NR 20 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 3335 EP 3337 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903131 ER PT J AU Armijo, KM Johnson, J Hibbs, M Fresquez, A AF Armijo, Kenneth M. Johnson, Jay Hibbs, Michael Fresquez, Armando GP IEEE TI Characterizing Fire Danger from Low-Power Photovoltaic Arc-Faults SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE Arc-Fault; PV Fire; Characterization; Modeling AB While arc-faults are rare in photovoltaic installations, more than a dozen documented arc-faults have led to fires and resulted in significant damage to the PV system and surrounding structures. In the United States, National Electrical Code (R) (NEC) 690.11 requires a listed arc fault protection device on new PV systems. In order to list new arc-fault circuit interrupters (AFCIs), Underwriters Laboratories created the certification outline of investigation UL 1699B. The outline only requires AFCI devices to be tested at arc powers between 300-900 W; however, arcs of much less power are capable of creating fires in PV systems. In this work we investigate the characteristics of low power (100-300 W) arc-faults to determine the potential for fires, appropriate AFCI trip times, and the characteristics of the pyrolyzation process. This analysis was performed with experimental tests of arc-faults in close proximity to three polymer materials common in PV systems, e.g., polycarbonate, PET, and nylon 6,6. Two polymer geometries were tested to vary the presence of oxygen in the DC arc plasma. The samples were also exposed to arcs generated with different material geometries, arc power levels, and discharge times to identify ignition times. To better understand the burn characteristics of different polymers in PV systems, thermal decomposition of the sheath materials was performed using infrared spectra analysis. Overall a trip time of less than 2 seconds is recommended for the suppression of fire ignition during arc-fault events. C1 [Armijo, Kenneth M.; Johnson, Jay; Hibbs, Michael; Fresquez, Armando] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Armijo, KM (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 24 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 3384 EP 3390 PG 7 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903140 ER PT J AU Flicker, J Johnson, J Albers, M Ball, G AF Flicker, Jack Johnson, Jay Albers, Mark Ball, Greg GP IEEE TI Recommendations for CSM and R-iso Ground Fault Detector Trip Thresholds SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE Riso; RCD; SPICE; ground faults AB PV ground faults have caused many fires in the U.S. and around the world. One cause of these fires is a "blind spot" in the ground fault ground fault fuse.. As a result of this discovery, the Solar America Board for Codes and Standards identified a number of alternatives to ground fault fuses, but these technologies have limited historical use in the United States. This paper investigates the efficacy of two of these devices, isolation resistance monitoring (R-iso) and current sense monitoring (CSM), in small (similar to 3 kW) and large (>500 kW) arrays using both simulation and field data. The field data includes R-iso and leakage current measurements of multiple PV systems, while the simulations include R-iso and CSM measurements from various ground faults. From these results, it was found that the majority of leakage current is not from the modules, but from low inverter isolation-to-ground. Therefore appropriate thresholds to maximize detection area while minimizing nuisance tripping should be made based on the specific inverter isolation and switching noise rather than the configuration of the PV system. C1 [Flicker, Jack; Johnson, Jay] Sandia Natl Labs, Albuquerque, NM 87185 USA. [Albers, Mark] Sunpower Corp, Richmond, CA 94804 USA. [Ball, Greg] DNV GL Energy, San Francisco, CA 94104 USA. RP Flicker, J (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 16 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 3391 EP 3397 PG 7 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903141 ER PT J AU Tatavarti, R Ban, KY Wibowo, A Kuciauskas, D Guthre, H Jones, K Johnston, S Norman, A Levi, D Al-Jassim, M AF Tatavarti, Rao Ban, Keun-Yong Wibowo, Andree Kuciauskas, Darius Guthre, Harvey Jones, Kim Johnston, Steve Norman, Andrew Levi, Dean Al-Jassim, Mowafak GP IEEE TI Minority Carrier Lifetimes in 1.0-eV p-In0.27Ga0.73As Layers Grown on GaAs Substrates SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE InGaAs; metamorphic layers; carrier lifetime; photovoltaic cells; cathodoluminescence; TEM and photoluminescence ID INGAAS AB Time-resolved photoluminescence (TRPL) measurements indicated minority carrier lifetimes of 15 ns for electrons in 2-mu m thick layers of 1.0-eV p-In0.27Ga0.73As grown on 6-inch GaAs wafers. Electron lifetimes increased from 10 ns to 15 ns as the thickness of 1.0-eV p-In0.27Ga0.73As was increased from 0.5 mu m to 2 mu m. The electron lifetimes decreased from 15 ns for a p-InxGa1-xAs with a doping density of 1x10(17) cm(-3) to 5 ns for a doping density of 5x10(17) cm(-3). Cathodoluminescence imaging measurements indicated dislocation densities of 7.9x10(5) cm(-2) for a 1.0-mu m thick layer of p-In0.27Ga0.73As (1.0eV) at the center of the wafer and 1.4x10(6) cm(-2) towards the edge. Cross-section transmission electron microscopy studies were performed to study dislocation blocking and threading dislocation propagation through the metamorphic graded AlInGaAs layers. C1 [Tatavarti, Rao; Ban, Keun-Yong; Wibowo, Andree] MicroLink Devices, Niles, IL 60714 USA. [Kuciauskas, Darius; Guthre, Harvey; Jones, Kim; Johnston, Steve; Norman, Andrew; Levi, Dean; Al-Jassim, Mowafak] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Tatavarti, R (reprint author), MicroLink Devices, Niles, IL 60714 USA. RI Norman, Andrew/F-1859-2010 OI Norman, Andrew/0000-0001-6368-521X NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 3414 EP 3416 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903145 ER PT J AU Perkms, JD Ke, Y Lany, S Berry, JJ Zakutayev, A Gorman, B Ohno, T Parilla, PA O'Hayre, R Ginley, DS AF Perkms, J. D. Ke, Y. Lany, S. Berry, J. J. Zakutayev, A. Gorman, B. Ohno, T. Parilla, P. A. O'Hayre, R. Ginley, D. S. GP IEEE TI Improving Electron Transport in Ga-doped Zn0.7Mg0.3O, a Wide-Gap Band-Edge-Energy-Tunable Transparent Conducting Oxide SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE ZnO; Transparent Conducting Oxide; TCO; Thin Film; Sputter ID FILMS AB The band gap increase in Zn(Mg)O alloys with increasing Mg enables tunable control of the conduction band alignment. However, the conductivity decreases monotonically with increasing Mg. Here, we show that the leading cause of the conductivity decrease is the increased formation of acceptor-like compensating intrinsic defects, such as zinc vacancies (V-Zn), which reduce the free electron concentration and decrease the mobility through ionized impurity scattering. Post-deposition annealing of Ga-doped Zn0.7Mg0.3O films grown by pulsed laser deposition increases the mobility by 50% due to pairing of oppositely charged defects, resulting in a conductivity as high as sigma = 475 S/cm. C1 [Perkms, J. D.; Ke, Y.; Lany, S.; Berry, J. J.; Zakutayev, A.; Parilla, P. A.; Ginley, D. S.] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Ke, Y.; Gorman, B.; Ohno, T.; O'Hayre, R.] Colorado Sch Mines, Dept Met & Mat Engn, Golden, CO 80401 USA. RP Perkms, JD (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. OI Zakutayev, Andriy/0000-0002-3054-5525 NR 6 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 3435 EP 3437 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903151 ER PT J AU Crisp, RW Panthani, MG Berry, JJ Rance, WL Duenow, JN Talapin, DV Luther, JM AF Crisp, Ryan W. Panthani, Matthew G. Berry, Joseph J. Rance, William L. Duenow, Joel N. Talapin, Dmitri V. Luther, Joseph M. GP IEEE TI Nanoscale Engineering of Solution-processed CdTe Solar Cells using Nanocrystalline Precursors SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE Cadmium compounds; contacts; nanocrystals; photovoltaic cells; Zinc compounds ID SURFACE AB We have furthered the development of CdTe nanocrystals (NCs) to create bulk, sintered films for ink-based solar cells. Here, respectable efficiencies of >10% have been achieved in devices where CdTe tetrapods are spincoated from pyridine, treated with CdCl2 and briefly annealed. We have inserted these NC-based CdTe layers into more than three device geometries with various contact layers. In one structure, we determine that there is a unique interface that forms between the ITO layer and CdTe layer providing excellent ohmic hole contact after a brief light soak in forward bias. Moreover, the devices have an impressive blue-response in comparison to standard CdTe solar cells despite having the junction at the back of the optical path rather than as a window layer. C1 [Crisp, Ryan W.] Colorado Sch Mines, Golden, CO 80401 USA. [Crisp, Ryan W.; Berry, Joseph J.; Rance, William L.; Duenow, Joel N.; Luther, Joseph M.] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Panthani, Matthew G.; Talapin, Dmitri V.] Univ Chicago, Chicago, IL 60637 USA. RP Crisp, RW (reprint author), Colorado Sch Mines, Golden, CO 80401 USA. OI Panthani, Matthew/0000-0002-3795-2051 NR 8 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 3438 EP 3441 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903152 ER PT J AU Nemeth, B Young, DL Yuan, HC LaSalvia, V Norman, AG Page, M Lee, BG Stradins, P AF Nemeth, Bill Young, David L. Yuan, Hao-Chih LaSalvia, Vincenzo Norman, Andrew G. Page, Matthew Lee, Benjamin G. Stradins, Paul GP IEEE TI Low Temperature Si/SiOx/pc-Si Passivated Contacts to n-Type Si Solar Cells SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE passivated contacts; silicon solar cells; polysilicon; silicon dioxide AB We describe the design, fabrication, and results of low-recombination, passivated contacts to n-type silicon utilizing thin SiOx, and plasma enhanced chemical vapor deposited doped polycrystalline-silicon (pc-Si) layers. A low-temperature silicon dioxide layer is grown on both surfaces of an n-type CZ wafer to a thickness of < 20 angstrom. Next, a thin layer of P-doped plasma enhanced chemical vapor deposited amorphous silicon (n/a-Si:H) is deposited on top of the SiOx. The layers are annealed to crystallize the a-Si:H and diffuse H to the Si/SiOx interface, after which a metal contacting layer is deposited over the conducting pc-Si layer. The contacts are characterized by measuring the recombination current parameter of the full-area contact (J(o,contact)) to quantify the passivation quality, and the specific contact resistivity (rho(contact)). The Si/SiOx/pc-Si contact has an excellent J(o,contact) = 3 0 fA/cm(2) and a good rho(contact) = 29.5 mOhm-cm(2). Separate processing conditions lowered J(o,contact) to 12 fA/cm(2). However, the final metallization can substantially degrade this contact and has to be carefully engineered. This contact could be easily incorporated into modern, high-efficiency solar cell designs, benefiting performance and yet simplifying processing by lowering the temperature and growth on only one side of the wafer. C1 [Nemeth, Bill; Young, David L.; Yuan, Hao-Chih; LaSalvia, Vincenzo; Norman, Andrew G.; Page, Matthew; Lee, Benjamin G.; Stradins, Paul] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Nemeth, B (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Norman, Andrew/F-1859-2010 OI Norman, Andrew/0000-0001-6368-521X NR 9 TC 2 Z9 2 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 3448 EP 3452 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903154 ER PT J AU Bertoni, MI Bernardini, S Johnston, S Al-Jassim, M Lai, B AF Bertoni, M. I. Bernardini, S. Johnston, S. Al-Jassim, M. Lai, B. GP IEEE TI Correlating Defect Band Luminesce to Elemental Distribution by X-ray Fluorescence SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE Photoluminescence; multicrystalline silicon; X-ray fluorescence; sub-band PL; PL band reversal ID LOCK-IN THERMOGRAPHY; SOLAR-CELLS; MULTICRYSTALLINE SILICON; ROOM-TEMPERATURE; BEHAVIOR; WAFERS AB Photoluminescence (PL) imaging is a widely accepted tool to characterize the quality of multicrystalline and monocrystalline silicon cells. Recently a set of neighboring multicrystalline silicon wafers taken from a cell production line at different stages of processing have shown an unexpected PL trend. Band-to-band PL (BPL) and sub-bandgap PL (subPL), where collected for the entire silicon wafers. Interestingly, a reversal of the subPL intensity in various regions of the wafer is observed right after the deposition of the anti-reflective coating (ARC). Regions with low subPL intensity before ARC exhibit high subPL intensity afterwards, and the opposite holds true for other regions of the wafer. Some authors have performed high-resolution cathodoluminesce spectroscopy, EBIC and dark lock-in-thermography to elucidate the origin of this phenomenon, In this work we present the results of the nanoscale X-ray fluorescence imaging at the points of subPL reversal to evaluate the role of metal decoration on this uncommon behavior and we complement it with our previous findings on the distribution of impurities during cell processing. C1 [Bertoni, M. I.; Bernardini, S.] Arizona State Univ, Tempe, AZ 85287 USA. [Johnston, S.; Al-Jassim, M.] Natl Renewable Energy Lab, Golden, CO USA. [Lai, B.] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Bertoni, MI (reprint author), Arizona State Univ, Tempe, AZ 85287 USA. NR 27 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 3470 EP 3472 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903158 ER PT J AU Ihly, R Nanayakkara, SU Gao, JB Zhang, JB Law, M Luther, JM AF Ihly, Rachelle Nanayakkara, Sanjini U. Gao, Jianbo Zhang, Jianbing Law, Matt Luther, Joseph M. GP IEEE TI Imaging Interfacial Layers and Internal Fields in Nanocrystalline Junctions SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE quantum dot solar cells; multiple exciton generation; carrier multiplication; PbSe; PbS; heterostructures; atomic force microscopy; Kelvin probe ID DOT SOLAR-CELLS; PROBE FORCE MICROSCOPY; QUANTUM; SOLIDS AB Nanotechnology will likely play a large role in developing future-generation solar photoconversion concepts. Thus, improved resolution or new techniques with the ability to characterize electronic properties of exceptionally small features could greatly aid device design. For example, photovoltaic devices with conductive films of colloidally synthesized PbSe quantum dots (QDs) possess external quantum efficiencies in the blue region of the solar spectrum greater than 100% due to multiple exciton generation (MEG) (where a high-energy photon can produce multiple electron-hole pairs) (1). This greatly motivates continued research on this type of solar cell that has the potential to achieve >40% power conversion efficiency (2). The state-of-the-art (highest overall efficiency) optimized structure for lead chalcogenide QD solar cells uses a variety of interfacial layers that play an important role in the device functionality. The p-n heterojunction (3) model is often used to describe the operation of QD solar cells despite the complex electronic structure of a disordered array of QDs acting as a macroscopic thin-film semiconductor (4). Advancements in device efficiency could follow better understanding of energetics along interfaces, throughout coupled films, and within individual nanostructures. Atomic force microscopy (AFM) techniques offer exceptional spatial resolution that can resolve such properties within devices and individual structures. Scanning Kelvin probe microscopy (SKPM) is one such technique that can accomplish these goals. We have correlated the contact potential difference between a conductive AFM tip and the layers within an operating colloidal QD solar cell with device cross-section exposed. SKPM can also be used on isolated nanostructures to visualize regions of localized band bending and space charge. C1 [Ihly, Rachelle; Nanayakkara, Sanjini U.; Gao, Jianbo; Zhang, Jianbing; Luther, Joseph M.] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Ihly, Rachelle; Law, Matt] Univ Calif Irvine, Irvine, CA USA. RP Ihly, R (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 22 TC 0 Z9 0 U1 2 U2 6 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 3498 EP 3501 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903164 ER PT J AU Johnson, J Armijo, K AF Johnson, Jay Armijo, Kenneth GP IEEE TI Parametric Study of PV Arc-Fault Generation Methods and Analysis of Conducted DC Spectrum SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE arc-fault circuit interrupters; arc-fault detectors; photovoltaic systems; PV reliability; UL 1699B AB Many photovoltaic (PV) direct current (DC) arc-fault detectors use the frequency content of the PV system to detect arcs. The spectral content is influenced by the duration and power of the arc, surrounding insulation material geometry and chemistry, and electrode geometry. A parametric analysis was conducted in order to inform the Underwriters Laboratories (UL) 1699B ("Photovoltaic DC Arc-Fault Circuit Protection") Standards Technical Panel (STP) of improvements to arc-fault generation methods in the certification standard. These recommendations are designed to reduce the complexity of the experimental setup, improve testing repeatability, and quantify the uncertainty of the arc-fault radio frequency (RF) noise generated by different PV arcs in the field. In this investigation, we (a) discuss the differences in establishing and sustaining arc-faults for a number of different test configurations and (b) compare the variability in arc-fault spectral content for each respective test, and analyze the evolution of the RF signature over the duration of the fault; with the ultimate goal of determining the most repeatable, 'worst case' tests for adoption by UL. C1 [Johnson, Jay; Armijo, Kenneth] Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Johnson, J (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 15 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 3543 EP 3548 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903174 ER PT J AU Yang, BB Armijo, KM Harrison, RK Thomas, KE Johnson, J Taylor, JM Sorensen, NR AF Yang, Benjamin B. Armijo, Kenneth M. Harrison, Richard K. Thomas, Kara E. Johnson, Jay Taylor, Jason M. Sorensen, N. Robert GP IEEE TI Arc Fault Risk Assessment and Degradation Model Development for Photovoltaic Connectors SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE connector; arc fault; reliability AB This work investigates balance of systems (BOS) connector reliability from the perspective of arc fault risk. Accelerated tests were performed on connectors for future development of a reliability model. Thousands of hours of damp heat and atmospheric corrosion tests found BOS connectors to be resilient to corrosion-related degradation. A procedure was also developed to evaluate new and aged connectors for arc fault risk. The measurements show that arc fault risk is dependent on a combination of materials composition as well as design geometry. Thermal measurements as well as optical emission spectroscopy were also performed to further characterize the arc plasma. Together, the degradation model, arc fault risk assessment technique, and characterization methods can provide operators of photovoltaic installations information necessary to develop a data-driven plan for BOS connector maintenance as well as identify opportunities for arc fault prognostics. C1 [Yang, Benjamin B.; Armijo, Kenneth M.; Harrison, Richard K.; Thomas, Kara E.; Johnson, Jay; Taylor, Jason M.; Sorensen, N. Robert] Sandia Natl Labs, Albuquerque, NM 87185 USA. [Thomas, Kara E.] George Washington Univ, Washington, DC 20052 USA. RP Yang, BB (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 12 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 3549 EP 3554 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903175 ER PT J AU Eguchi, Y Ramu, G Lokanath, SV Yamamichi, M Kurtz, S Wohlgemuth, J Yamada, E Kondo, M AF Eguchi, Yoshihito Ramu, Govind Lokanath, Sumanth V. Yamamichi, Masaaki Kurtz, Sarah Wohlgemuth, John Yamada, Eiji Kondo, Michio GP IEEE TI Requirements for Quality Management System for PV Module Manufacturing SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE design; reliability; photovoltaic module; quality management; warranty AB As the PV industry has grown, there is much concern in the markets about whether low photovoltaic (PV) module prices are leading to inferior products being introduced into the market. For protection of consumers, and also industries it is necessary to establish and standardize the suitable evaluation method of long-term reliability of PV modules. A quality management system for PV module production is one of the key elements to secure the long-term reliability of PV modules. This paper describes the requirements for quality management systems for PV module manufacturers to produce PV modules which secure the consistency of the design, production and product warranty. C1 [Eguchi, Yoshihito; Yamada, Eiji] Japan Elect safety & Environm Technol Labs, Tsurumi Ku, Yokohama, Kanagawa, Japan. [Ramu, Govind] SunPower Corp, San Jose, CA 95134 USA. [Lokanath, Sumanth V.] First Solar Inc, Tempe, AZ 85281 USA. [Yamamichi, Masaaki; Kondo, Michio] Natl Inst Adv Ind Sci & Technol, Tsukuba, Ibaraki, Japan. [Kurtz, Sarah; Wohlgemuth, John] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Eguchi, Y (reprint author), Japan Elect safety & Environm Technol Labs, Tsurumi Ku, 1-12-18 Motomiya, Yokohama, Kanagawa, Japan. NR 4 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 3574 EP 3579 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903179 ER PT J AU Wohlgemuth, J Kurtz, S AF Wohlgemuth, Jom Kurtz, Sarah GP IEEE TI Photovoltaic Module Qualification Plus Testing SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE reliability and durability of PV modules; accelerated stress testing; Quality Management Systems; potential-induced degradation AB Reliability is a critical element in the continued growth of the photovoltaic (PV) industry. Design qualification tests such as IEC 61215 and IEC 61646 have been key to mitigating infant mortality, but do not address many of the module failures now observed in the field. Qualification Plus has been created to fill an immediate need by providing a well-defined set of accelerated stress tests that correlate with the field performance of PV modules. The tests in Qualification Plus include module-level tests like those in the qualification test sequences, as well as material and component level tests like those in the module safety standard. This paper will describe the details of Qualification Plus including the rationale for the required tests, the selection of samples, and the requirements for the Quality Management System. C1 [Wohlgemuth, Jom; Kurtz, Sarah] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Wohlgemuth, J (reprint author), Natl Renewable Energy Lab, 15013 Denver West Pkwy, Golden, CO 80401 USA. NR 28 TC 2 Z9 2 U1 0 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 3589 EP 3594 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903182 ER PT J AU Fenning, DP Vahanissi, V Hofstetter, J Morishige, AE Laine, H Haarahiltunen, A Castellanos, S Jensen, MA Lai, B Savin, H AF Fenning, D. P. Vahanissi, V. Hofstetter, J. Morishige, A. E. Laine, H. Haarahiltunen, A. Castellanos, S. Jensen, M. Ann Lai, B. Savin, H. GP IEEE TI Iron Precipitation upon Gettering in Phosphorus-Implanted Czochralski Silicon and its Impact on Solar Cell Performance SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE emitter; gettering; implantation; iron; X-ray fluorescence AB Phosphorus implantation can provide a direct route to a high-performing emitter, with no surface dead layer and improved blue response, and potentially higher open-circuit voltage. Here, iron precipitation during gettering is investigated in phosphorus-implanted, low-oxygen monocrystalline silicon and its impact on device performance evaluated. Previously, it has been shown that higher levels of initial iron contamination lead to lower final interstitial iron concentration after gettering with ion-implanted emitters, resulting in longer final bulk diffusion lengths in the more-highly contaminated materials. In this contribution, we show that despite longer bulk diffusion lengths, the open circuit-voltage of devices made from the highly iron-contaminated material can be strongly reduced. Using synchrotron-based X-ray fluorescence we reveal the presence of micron-sized iron precipitates in the near surface region. While not measured over wafer-sized areas, the density of these precipitates correlates with the annealing profile. Slow-cooling from the activation anneal and proceeding directly to a 620-750 degrees C gettering anneal results in large precipitates that are indicated as the underlying cause for the disastrous open-circuit voltage. On the other hand, quickly cooling to room temperature and then re-inserting the wafers for gettering results in very small precipitates that do not appear to have significant detrimental affects on open-circuit voltage. It is thus critical to consider the precipitation behavior of iron during gettering of ion-implanted emitters - even in monocrystalline silicon - and during low-temperature annealing in general. C1 [Fenning, D. P.; Hofstetter, J.; Morishige, A. E.; Castellanos, S.; Jensen, M. Ann] MIT, Cambridge, MA 02139 USA. [Fenning, D. P.] Univ Calif San Diego, Dept Nanoengn, La Jolla, CA 92093 USA. [Vahanissi, V.; Laine, H.; Haarahiltunen, A.; Savin, H.] Aalto Univ, Dept Micro & Nanosci, Espoo 02150, Finland. [Lai, B.] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Fenning, DP (reprint author), MIT, 77 Massachusetts Ave, Cambridge, MA 02139 USA. EM dfenning@alum.mit.edu RI Savin, Hele/E-5155-2012; OI Savin, Hele/0000-0003-3946-7727; Morishige, Ashley/0000-0001-9352-8741 NR 15 TC 1 Z9 1 U1 2 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 3641 EP 3643 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903194 ER PT J AU Campanelli, M Emery, K Elmore, R Zaharatos, B AF Campanelli, Mark Emery, Keith Elmore, Ryan Zaharatos, Brian GP IEEE TI Uncertainty Analysis for Maximum Power at SRC Using Hierarchical Monte Carlo Simulation SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE calibration; hierarchical modeling; maximum power; measurement uncertainty; Monte Carlo simulation; noise; uncertainty analysis AB We present an uncertainty analysis (UA) for the maximum power of photovoltaic devices at standard reporting conditions, denoted P-max0. The UA employs a hierarchical Monte Carlo (MC) simulation to sample from the state-of-knowledge probability distribution for P-max0, based upon an irradiance and spectrally corrected current-voltage curve measured (nominally) at 1-sun according to ASTM E948-09 or E1036-12. A conditional factoring of the joint distribution of the parameters that determine P-max0 allows rigorous consideration of both systematic (e.g., calibration chain) and random (e.g., solar simulator noise) sources of uncertainty in P-max0. The corresponding hierarchical MC simulation is computationally efficient and parallelizable, allowing enough samples to control MC sampling error. The UA method complies with the Guide to the Expression of Uncertainty in Measurement. C1 [Campanelli, Mark; Emery, Keith; Elmore, Ryan] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Zaharatos, Brian] Colorado Sch Mines, Golden, CO 80401 USA. RP Campanelli, M (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. 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 978-1-4799-4398-2 PY 2014 BP 3670 EP 3675 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903200 ER PT J AU Silverman, TJ Deceglie, MG Marion, B Kurtz, SR AF Silverman, Timothy J. Deceglie, Michael G. Marion, Bill Kurtz, Sarah R. GP IEEE TI Performance stabilization of CdTe PV modules using bias and light SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE CdTe; thin-film; module; performance; stabilization; light soak; metastability; transient ID SOLAR-CELLS AB Reversible performance changes due to light exposure frustrate repeatable performance measurements on CdTe photovoltaic modules. It is common to use extended light exposure to ensure that measurements are representative of outdoor performance. We quantify the extent to which such a light-exposed state depends on module temperature and consider bias in the dark to aid in stabilization. We evaluate the use of dark forward bias to bring about a performance state equivalent to that obtained with light exposure, and to maintain a light-exposed state prior to standard test condition (STC) performance measurement. Our results indicate that the most promising method for measuring a light-exposed state is to use light exposure at controlled temperature followed by prompt STC measurement with a repeatable time interval between exposure and the STC measurement. C1 [Silverman, Timothy J.; Deceglie, Michael G.; Marion, Bill; Kurtz, Sarah R.] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Silverman, TJ (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. 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 978-1-4799-4398-2 PY 2014 BP 3676 EP 3681 PG 6 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903201 ER PT J AU Morse, J Campanelli, M Emery, K AF Morse, Joshua Campanelli, Mark Emery, Keith GP IEEE TI Sensitivity of Concentrating Photovoltaics to Solar Tracking Error SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE acceptance angle; alignment sensitivity; concentrating photovoltaic performance characterization; data filtering; field of view; tracking error AB An asymmetric, three-parameter field-of-view (FOV) is defined and proposed as a more comprehensive alternative to the symmetric acceptance angle currently used to characterize concentrating photovoltaic device sensitivity to non-zero angles of incidence of solar irradiance. Normalized contour maps of module response against two-axis solar tracker errors in degrees were generated from module short-circuit current, maximum power, and current at maximum power measurements over a range of solar incidence angles. For each of these performance parameters, a quadric surface was fit using linear least squares to the upper 10% of the module response data set. The three-parameter FOV is defined as the elliptical area enclosed by the largest level curve of the fit surface that can be inscribed within a convex hull representation of the upper 10% data set. Applying this FOV as a tracking-error data filter for efficiency measurements from NREL's Prototype Concentrator Evaluation Test Bed (OCIV) resulted in an 8% increase in measured efficiency on one of the tested modules. C1 [Morse, Joshua] Univ Rochester, Rochester, NY 14627 USA. [Campanelli, Mark; Emery, Keith] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Morse, J (reprint author), Univ Rochester, 601 Elmwood Ave, Rochester, NY 14627 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 BP 3685 EP 3689 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638903203 ER PT J AU Ostrowski, DP Koldemir, U Anderson, R Sellinger, A Shaheen, SE AF Ostrowski, David P. Koldemir, Unsal Anderson, Ryan Sellinger, Alan Shaheen, Sean E. GP IEEE TI High Open Circuit Voltage Organic Photovoltaics: Minimizing Energetic Loss with a High Band Gap Donor Polymer and a Small-Molecule Acceptor SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE open circuit voltage; organic photovoltaic; high band gap polymer donor; small molecule acceptor ID SOLAR-CELLS; CONVERSION EFFICIENCY AB Solution-processed, bulk-heterojunction Organic Photovoltaic (OPV) devices with a high V-oc (up to 1.35 V) were fabricated with a high band gap electron-donor copolymer blended with a small-molecule electron-acceptor. The copolymer (PInCZ), based on carbazole and indolocarbazole monomers, posseses a deep lying HOMO (Highest Occupied Molecular Orbital) of -5.6 eV. Coupling this polymer with the small-molecule acceptor (HPI-BT), with a relatively shallow LUMO (Lowest Occupied Molecular Orbital) near -3.6 eV, resulted in an effective electronic band gap in the donor-acceptor pair of approximately 2.0 eV. This value, which is important in determining the maximum V-oc attainable in the device, is substantially higher than the typical values found in OPV devices of similar to 1.0 - 1.5 eV. In the devices presented here, the thermodynamic loss in energy from the optical band gap compared to the V-oc is similar to 41%, which is substantially lower than that commonly found in OPV materials of 50+%. C1 [Ostrowski, David P.; Shaheen, Sean E.] Univ Colorado, Dept Elect Comp & Energy Engn, Boulder, CO 80309 USA. [Koldemir, Unsal; Anderson, Ryan; Sellinger, Alan] Colorado Sch Mines, Dept Chem & Geochem, Golden, CO 80401 USA. [Sellinger, Alan] Natl Renewable Energy Lab, Natl Ctr Photovolta, Golden, CO 80401 USA. [Shaheen, Sean E.] RASEI, Boulder, CO 80309 USA. RP Ostrowski, DP (reprint author), Univ Colorado, Dept Elect Comp & Energy Engn, Boulder, CO 80309 USA. RI Shaheen, Sean/M-7893-2013 NR 8 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 PG 3 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900002 ER PT J AU Young, DL Nemeth, W Grover, S Norman, A Lee, BG Stradins, P AF Young, David L. Nemeth, William Grover, Sachit Norman, Andrew Lee, Benjamin G. Stradins, Paul GP IEEE TI Carrier-Selective, Passivated Contacts for High Efficiency Silicon Solar Cells Based on Transparent Conducting Oxides SO 2014 IEEE 40TH PHOTOVOLTAIC SPECIALIST CONFERENCE (PVSC) LA English DT Proceedings Paper CT 40th IEEE Photovoltaic Specialists Conference (PVSC) CY JUN 08-13, 2014 CL Denver, CO SP IEEE, Electron Devices Soc, IEEE Photon Soc, IEEE Power & Energy Soc, Reliabil Soc, IEEE USA DE passivated contacts; ITO; SiO2; silicon; solar cells ID INTERFACE AB We describe the design, fabrication and results of passivated contacts to n-type silicon utilizing thin SiO2 and indium tin oxide. High-temperature silicon dioxide is grown on both surfaces on an n-type Si wafer to a thickness <50 angstrom, followed by deposition of tin-doped indium oxide (ITO) and a patterned metal contacting layer. As deposited, the thin-film stack has a very high recombination parameter, J(0,contact), and a non-ohmic, high contact resistance. However, after a forming gas anneal, the passivation quality and the contact resistivity improve significantly. The contacts are characterized by measuring the recombination parameter current density of the contact (J(0,contact)) and the specific contact resistivity (rho(contact)) using a transmission line method (TLM) pattern. The best ITO/SiO2 passivated contact in this study has J(0,contact) = 93.5 fA/cm(2) and rho(contact) = 11.5 mOhm-cm(2). These values are placed in context with other passivating contacts using an analysis that determines the ultimate efficiency and the optimal area fraction for contacts for a given set of (J(0,contact), rho(contact)) values. The ITO/SiO2 contacts are found to have a higher J(0,contact), but a similar rho(contact) compared to the best reported passivated contacts. C1 [Young, David L.; Nemeth, William; Grover, Sachit; Norman, Andrew; Lee, Benjamin G.; Stradins, Paul] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Young, DL (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-4398-2 PY 2014 PG 5 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BE0QY UT WOS:000366638900001 ER PT J AU Jiang, M Van Essen, B Harrison, C Gokhale, M AF Jiang, Ming Van Essen, Brian Harrison, Cyrus Gokhale, Maya BE Childs, H Pajarola, R Vishwanath, V TI Multi-Threaded Streamline Tracing for Data-Intensive Architectures SO 2014 IEEE 4TH SYMPOSIUM ON LARGE DATA ANALYSIS AND VISUALIZATION (LDAV) LA English DT Proceedings Paper CT IEEE Symposium on Large Data Analysis and Visualization CY OCT 09-10, 2014 CL Paris, FRANCE SP IEEE, IEEE Comp Soc, IEEE VGTC DE streamline tracing; memory-map; data management; out-of-core algorithms; data-intensive computing ID FIELDS AB Streamline tracing is an important tool used in many scientific domains for visualizing and analyzing flow fields. In this work, we examine a shared memory multi-threaded approach to streamline tracing that targets emerging data-intensive architectures. We take an in-depth look at data management strategies for streamline tracing in terms of issues, such as memory latency, bandwidth, and capacity limitations, that are applicable to future HPC platforms. We present two data management strategies for streamline tracing and evaluate their effectiveness for data-intensive architectures with locally attached Flash. We provide a comprehensive evaluation of both strategies by examining the strong and weak scaling implications of a variety of parameters. We also characterize the relationship between I/O concurrency and I/O efficiency to guide the selection of strategy based on use case. From our experiments, we find that using kernel-managed memory-map for out-of-core streamline tracing can outperform optimized user-managed cache. C1 [Jiang, Ming; Van Essen, Brian; Harrison, Cyrus; Gokhale, Maya] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Jiang, M (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM jiang4@llnl.gov; vanessen1@llnl.gov; harrison37@llnl.gov; gokhale2@llnl.gov NR 29 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5215-1 PY 2014 BP 11 EP 18 PG 8 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BF2PB UT WOS:000380487000002 ER PT J AU Widanagamaachchi, W Bremer, PT Sewell, C Lo, LT Ahrens, J Pascucci, V AF Widanagamaachchi, Wathsala Bremer, Peer-Timo Sewell, Christopher Lo, Li-Ta Ahrens, James Pascucci, Valerio BE Childs, H Pajarola, R Vishwanath, V TI Data-Parallel Halo Finding with Variable Linking Lengths SO 2014 IEEE 4TH SYMPOSIUM ON LARGE DATA ANALYSIS AND VISUALIZATION (LDAV) LA English DT Proceedings Paper CT IEEE Symposium on Large Data Analysis and Visualization CY OCT 09-10, 2014 CL Paris, FRANCE SP IEEE, IEEE Comp Soc, IEEE VGTC DE H.3 [INFORMATION STORAGE AND RETRIEVAL]: Information Search and Retrieval; Clustering; J.2 [PHYSICAL SCIENCES AND ENGINEERING]: Astronomy ID COLD DARK-MATTER; SIMULATIONS; EVOLUTION; CLUSTERS AB State-of-the-art cosmological simulations regularly contain billions of particles, providing scientists the opportunity to study the evolution of the Universe in great detail. However, the rate at which these simulations generate data severely taxes existing analysis techniques. Therefore, developing new scalable alternatives is essential for continued scientific progress. Here, we present a dataparallel, friends-of-friends halo finding algorithm that provides unprecedented flexibility in the analysis by extracting multiple linking lengths. Even for a single linking length, it is as fast as the existing techniques, and is portable to multi-threaded many-core systems as well as co-processing resources. Our system is implemented using PISTON and is coupled to an interactive analysis environment used to study halos at different linking lengths and track their evolution over time. C1 [Widanagamaachchi, Wathsala; Bremer, Peer-Timo; Pascucci, Valerio] Univ Utah, SCI Inst, Salt Lake City, UT 84112 USA. [Bremer, Peer-Timo] Lawrence Livermore Natl Lab, Livermore, CA USA. [Sewell, Christopher; Lo, Li-Ta; Ahrens, James] Los Alamos Natl Lab, Los Alamos, NM USA. RP Widanagamaachchi, W (reprint author), Univ Utah, SCI Inst, Salt Lake City, UT 84112 USA. EM wathsy@sci.utah.edu; bremer5@llnl.gov; csewell@lanl.gov; ollie@lanl.gov; ahrens@lanl.gov; pascucci@sci.utah.edu NR 25 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5215-1 PY 2014 BP 27 EP 34 PG 8 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BF2PB UT WOS:000380487000004 ER PT J AU Liu, SS Wang, B Thiagarajan, JJ Bremer, PT Pascucci, V AF Liu, Shusen Wang, Bei Thiagarajan, Jayaraman J. Bremer, Peer-Timo Pascucci, Valerio BE Childs, H Pajarola, R Vishwanath, V TI Multivariate Volume Visualization through Dynamic Projections SO 2014 IEEE 4TH SYMPOSIUM ON LARGE DATA ANALYSIS AND VISUALIZATION (LDAV) LA English DT Proceedings Paper CT IEEE Symposium on Large Data Analysis and Visualization CY OCT 09-10, 2014 CL Paris, FRANCE SP IEEE, IEEE Comp Soc, IEEE VGTC ID MULTIDIMENSIONAL TRANSFER-FUNCTIONS; DIMENSION PROJECTION; DATA SETS; EXPLORATION; FRAMEWORK AB We propose a multivariate volume visualization framework that tightly couples dynamic projections with a high-dimensional transfer function design for interactive volume visualization. We assume that the complex, high- dimensional data in the attribute space can be well-represented through a collection of low-dimensional linear subspaces, and embed the data points in a variety of 2D views created as projections onto these subspaces. Through dynamic projections, we present animated transitions between different views to help the user navigate and explore the attribute space for effective transfer function design. Our framework not only provides a more intuitive understanding of the attribute space but also allows the design of the transfer function under multiple dynamic views, which is more flexible than being restricted to a single static view of the data. For large volumetric datasets, we maintain interactivity during the transfer function design via intelligent sampling and scalable clustering. Using examples in combustion and climate simulations, we demonstrate how our framework can be used to visualize interesting structures in the volumetric space. C1 [Liu, Shusen; Wang, Bei; Pascucci, Valerio] Univ Utah, SCI Inst, Salt Lake City, UT 84112 USA. [Thiagarajan, Jayaraman J.; Bremer, Peer-Timo] Lawrence Livermore Natl Lab, Livermore, CA USA. RP Liu, SS (reprint author), Univ Utah, SCI Inst, Salt Lake City, UT 84112 USA. EM shusenl@sci.utah.edu; beiwang@sci.utah.edu; jayaramanthi1@llnl.gov; bremer5@llnl.gov; pascucci@sci.utah.educ NR 36 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5215-1 PY 2014 BP 35 EP 42 PG 8 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BF2PB UT WOS:000380487000005 ER PT J AU Nouanesengsy, B Woodring, J Patchett, J Myers, K Ahrens, J AF Nouanesengsy, Boonthanome Woodring, Jonathan Patchett, John Myers, Kary Ahrens, James BE Childs, H Pajarola, R Vishwanath, V TI ADR Visualization: A Generalized Framework for Ranking Large-Scale Scientific Data using Analysis-Driven Refinement SO 2014 IEEE 4TH SYMPOSIUM ON LARGE DATA ANALYSIS AND VISUALIZATION (LDAV) LA English DT Proceedings Paper CT IEEE Symposium on Large Data Analysis and Visualization CY OCT 09-10, 2014 CL Paris, FRANCE SP IEEE, IEEE Comp Soc, IEEE VGTC DE data triage; focus plus context; large-scale data; big data; scientific data; prioritization; adaptive mesh refinement; I.3.1 [Computer Graphics]: Hardware Architecture-Parallel processing; I.3.3 [Computer Graphics]: Picture/Image Generation-Viewing algorithms ID ADAPTIVE MESH REFINEMENT; VOLUME VISUALIZATION; FLOW VISUALIZATION; HYDRODYNAMICS; CODE; EQUATIONS AB Prioritization of data is necessary for managing large-scale scientific data, as the scale of the data implies that there are only enough resources available to process a limited subset of the data. For example, data prioritization is used during in situ triage to scale with bandwidth bottlenecks, and used during focus+context visualization to save time during analysis by guiding the user to important information. In this paper, we present ADR visualization, a generalized analysis framework for ranking large-scale data using Analysis -Driven Refinement (ADR), which is inspired by Adaptive Mesh Refinement (AMR). A large-scale data set is partitioned in space, time, and variable, using user-defined importance measurements for prioritization. This process creates a prioritization tree over the data set. Using this tree, selection methods can generate sparse data products for analysis, such as focus+context visualizations or sparse data sets. C1 [Nouanesengsy, Boonthanome; Woodring, Jonathan; Patchett, John; Myers, Kary; Ahrens, James] Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Nouanesengsy, B (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87544 USA. EM boonth@lanl.gov; woodring@lanl.gov; patchett@lanl.gov; kary@lanl.gov; ahrens@lanl.gov NR 29 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5215-1 PY 2014 BP 43 EP 50 PG 8 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BF2PB UT WOS:000380487000006 ER PT J AU Agranovsky, A Camp, D Garth, C Bethel, EW Joy, KI Childs, H AF Agranovsky, Alexy Camp, David Garth, Christoph Bethel, E. Wes Joy, Kenneth I. Childs, Hank BE Childs, H Pajarola, R Vishwanath, V TI Improved Post Hoc Flow Analysis Via Lagrangian Representations SO 2014 IEEE 4TH SYMPOSIUM ON LARGE DATA ANALYSIS AND VISUALIZATION (LDAV) LA English DT Proceedings Paper CT IEEE Symposium on Large Data Analysis and Visualization CY OCT 09-10, 2014 CL Paris, FRANCE SP IEEE, IEEE Comp Soc, IEEE VGTC DE flow visualization; high-performance computing; compression; particle advection; pathline interpolation ID 2D VECTOR-FIELDS; COHERENT STRUCTURES; VISUALIZATION; COMPRESSION AB Fluid mechanics considers two frames of reference for an observer watching a flow field: Eulerian and Lagrangian. The former is the frame of reference traditionally used for flow analysis, and involves extracting particle trajectories based on a vector field. With this work, we explore the opportunities that arise when considering these trajectories from the Lagrangian frame of reference. Specifically, we consider a form where flows are extracted in situ and then used for subsequent post hoc analysis. We believe this alternate, Lagrangian-based form will be increasingly useful, because the Eulerian frame of reference is sensitive to temporal frequency, and architectural trends are causing temporal frequency to drop rapidly on modern supercomputers. We support our viewpoint by running a series of experiments, which demonstrate the Lagrangian form can be more accurate, require less I/O, and be faster when compared to traditional advection. C1 [Agranovsky, Alexy; Joy, Kenneth I.] Univ Calif Davis, Davis, CA 95616 USA. [Agranovsky, Alexy; Camp, David; Bethel, E. Wes; Childs, Hank] Lawrence Berkeley Natl Labs, Berkeley, CA USA. [Childs, Hank] Univ Oregon, Eugene, OR 97403 USA. [Garth, Christoph] Univ Kaiserslautern, Kaiserslautern, Germany. RP Agranovsky, A (reprint author), Univ Calif Davis, Davis, CA 95616 USA. EM aagranovsky@ucdavis.edu; dcamp@lbl.gov; garth@cs.uni-kl.de; ewbethel@lbl.gov; joy@cs.ucdavis.edu; hank@uoregon.edu NR 27 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5215-1 PY 2014 BP 67 EP 75 PG 9 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BF2PB UT WOS:000380487000009 ER PT J AU Wong, PC Shen, HW Leung, R Hagos, S Lee, TY Tong, X Lu, KW AF Wong, Pak Chung Shen, Han-Wei Leung, Ruby Hagos, Samson Lee, Teng-Yok Tong, Xin Lu, Kewei BE Childs, H Pajarola, R Vishwanath, V TI Visual Analytics of Large-Scale Climate Model Data SO 2014 IEEE 4TH SYMPOSIUM ON LARGE DATA ANALYSIS AND VISUALIZATION (LDAV) LA English DT Proceedings Paper CT IEEE Symposium on Large Data Analysis and Visualization CY OCT 09-10, 2014 CL Paris, FRANCE SP IEEE, IEEE Comp Soc, IEEE VGTC DE Visual analytics application; large data analytics and visualization; climate analytics; scientific modeling ID SIMULATION AB This application paper presents a visual analytics tool designed to explore large-scale scientific data modeled after a natural climate phenomenon. The data are modeled on a high-performance computer and exported to a personal computer for interactive visualization. The system is co-designed by visual analytics researchers and domain scientists after a year of rapid prototyping and evaluation of multiple information and scientific visualization techniques using a model dataset that includes both scalar fields and flow fields. Five information-visualization and one scientific-visualization techniques are included in the visual analytics system to balance analytical effectiveness and computation time for large-scale interactive exploration. The paper discusses the system design, explains the design rationale, and shares computation performance and results of different visualization techniques. The primary contribution of this application paper is to show that we can interactively and effectively visualize a large amount of scientific model data on a modest desktop computer. The computation performance results of the individual visualization techniques and the overall system also provide benchmark references for other large-scale visualization development efforts. C1 [Wong, Pak Chung; Leung, Ruby; Hagos, Samson] Pacific Northwest Natl Lab, Richland, WA 99352 USA. [Shen, Han-Wei; Lee, Teng-Yok; Tong, Xin; Lu, Kewei] Ohio State Univ, Columbus, OH 43210 USA. RP Wong, PC (reprint author), Pacific Northwest Natl Lab, Richland, WA 99352 USA. EM pak.wong@pnnl.gov NR 15 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5215-1 PY 2014 BP 85 EP 92 PG 8 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BF2PB UT WOS:000380487000011 ER PT J AU Fardad, M Zhang, X Lin, F Jovanovic, MR AF Fardad, Makan Zhang, Xi Lin, Fu Jovanovic, Mihailo R. GP IEEE TI On the Properties of Optimal Weak Links in Consensus Networks SO 2014 IEEE 53RD ANNUAL CONFERENCE ON DECISION AND CONTROL (CDC) LA English DT Proceedings Paper CT 53rd IEEE Annual Conference on Decision and Control (CDC) CY DEC 15-17, 2014 CL Los Angeles, CA SP IEEE, MathWorks, Springer, Altair, dSPACE, Journal Franklin Inst, Soc Ind & Appl Math, United Technologies Res Ctr, Wolfram, EBSCO Informat Serv, Inst Engn & Technol, Now, Taylor & Francis, Cogent Engn DE Convex optimization; linear programming; long-range links; opinion dynamics; perturbation analysis; social networks; sparsity ID SMALL-WORLD NETWORKS; PERIODIC-SYSTEMS; SYNCHRONIZATION; ALGORITHMS; TURBULENCE; STABILITY; DESIGN; GRAPHS; ONSET; NORM AB We study consensus networks in which each node updates its state by taking a weighted average of the states of its neighbors. Our objective is to determine the optimal set of weak links whose addition to the network maximally improves the efficiency of reaching consensus. Allocating a small amount of resources to the entire network with which new links can be created, we employ a perturbation method to cast this problem as a linear program. We demonstrate that the set of optimal weak links is sparse and, based on extensive numerical experiments, conjecture that they are also long-range. Examples are provided to illustrate the utility of our developments. C1 [Fardad, Makan; Zhang, Xi] Syracuse Univ, Dept Elect Engn & Comp Sci, Syracuse, NY 13244 USA. [Lin, Fu] Argonne Natl Lab, Math & Comp Sci Div, Argonne, IL 60439 USA. [Jovanovic, Mihailo R.] Univ Minnesota, Dept Elect & Comp Engn, Minneapolis, MN 55455 USA. RP Fardad, M (reprint author), Syracuse Univ, Dept Elect Engn & Comp Sci, Syracuse, NY 13244 USA. EM makan@syr.edu; xzhang49@syr.edu; fulin@mcs.anl.gov; mihailo@umn.edu NR 25 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4673-6090-6 PY 2014 BP 2124 EP 2129 PG 6 WC Automation & Control Systems SC Automation & Control Systems GA BE2TY UT WOS:000370073802045 ER PT J AU Li, S Zhang, W Lian, JM Kalsi, K AF Li, Sen Zhang, Wei Lian, Jianming Kalsi, Karanjit GP IEEE TI On Market-Based Coordination of Thermostatically Controlled Loads With User Preference SO 2014 IEEE 53RD ANNUAL CONFERENCE ON DECISION AND CONTROL (CDC) LA English DT Proceedings Paper CT IEEE 53rd Annual Conference on Decision and Control (CDC) CY DEC 15-17, 2014 CL Los Angeles, CA SP IEEE, MathWorks, Springer, Altair, dSPACE, Journal Franklin Inst, Soc Ind & Appl Math, United Technologies Res Ctr, Wolfram, EBSCO Informat Serv, Inst Engn & Technol, Now, Taylor & Francis, Cogent Engn AB This paper presents a market-based control framework to coordinate a group of Thermostatically Controlled Loads (TCL) to achieve system-level objectives with price incentives. The problem is formulated as maximizing the social welfare subject to a feeder power constraint. It allows the coordinator to affect the aggregated power of a group of dynamical systems, and creates an interactive market where the users and the coordinator cooperatively determine the optimal energy allocation and energy price. The optimal pricing strategy is derived, which maximizes social welfare while respecting the feeder power constraint. The bidding strategy is also designed for the coordinator to compute the optimal price based on local device information. Numerical simulations based on realistic price and model data are performed. The simulation results demonstrate that the proposed approach can effectively maximize the social welfare and reduce power congestion at key times. C1 [Li, Sen; Zhang, Wei] Ohio State Univ, Dept Elect & Comp Engn, Columbus, OH 43210 USA. [Lian, Jianming; Kalsi, Karanjit] Pacific NW Natl Lab, Elect Infrastruct Grp, Richland, WA 99354 USA. RP Li, S (reprint author), Ohio State Univ, Dept Elect & Comp Engn, Columbus, OH 43210 USA. EM li.2886@osu.edu; zhang@osu.edu; jianming.lian@pnnl.gov; karanjit.Kalsi@pnnl.gov RI Zhang, Wei/B-3219-2013; Zhang, Wei/L-2407-2016 OI Zhang, Wei/0000-0002-7511-2870 NR 13 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4673-6090-6 PY 2014 BP 2474 EP 2480 PG 7 WC Automation & Control Systems SC Automation & Control Systems GA BE2TY UT WOS:000370073802099 ER PT J AU Scheinker, A Gessner, S AF Scheinker, Alexander Gessner, Spencer GP IEEE TI Extremum Seeking for Parameter Identification, Implementation for Electron Beam Property Prediction SO 2014 IEEE 53RD ANNUAL CONFERENCE ON DECISION AND CONTROL (CDC) LA English DT Proceedings Paper CT IEEE 53rd Annual Conference on Decision and Control (CDC) CY DEC 15-17, 2014 CL Los Angeles, CA SP IEEE, MathWorks, Springer, Altair, dSPACE, Journal Franklin Inst, Soc Ind & Appl Math, United Technologies Res Ctr, Wolfram, EBSCO Informat Serv, Inst Engn & Technol, Now, Taylor & Francis, Cogent Engn ID SYSTEMS; STABILITY AB We report on an experiment performed at the Facility for Advanced Accelerator Experimental Tests (FACET), which is the first two kilometers of the Stanford Linear Accelerator Center (SLAC) linear accelerator, in which a new form of extremum seeking, one with known, bounded update rates, despite operating on an analytically unknown cost function, was utilized in order to provide a real time bunch length estimate of the electron beam. The approach was to simultaneously tune fourteen parameters, such as arbitrary klystron phase shifts and electron bunch energy, in order to match a simulated (LiTrack) bunch energy spread spectrum with the real time wiggler/scintillating YAG crystal signal. The simple adaptive scheme was digitally implemented using Matlab and the Experimental Physics and Industrial Control System (EPICS). The main result is the development of a non-intrusive, non-destructive real-time diagnostic scheme for prediction of bunch length, as well as other beam parameters, the precise control of which is very important for the plasma acceleration scheme being explored at FACET. C1 [Scheinker, Alexander] Los Alamos Natl Lab, RF Control Grp, Los Alamos, NM 87545 USA. [Gessner, Spencer] Stanford Univ, Stanford, CA 94305 USA. [Gessner, Spencer] Stanford Linear Accelerator Ctr, Adv Accelerator Expt Tests, Stanford, CA USA. RP Scheinker, A (reprint author), Los Alamos Natl Lab, RF Control Grp, Los Alamos, NM 87545 USA. EM ascheink@lanl.gov NR 29 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4673-6090-6 PY 2014 BP 2673 EP 2678 PG 6 WC Automation & Control Systems SC Automation & Control Systems GA BE2TY UT WOS:000370073802131 ER PT J AU Salapaka, S Johnson, B Lundstrom, B Kim, S Collyer, S Salapaka, M AF Salapaka, Srinivasa Johnson, Brian Lundstrom, Blake Kim, Sangsun Collyer, Scott Salapaka, Murti GP IEEE TI Viability and analysis of implementing only voltage-power droop for parallel inverter systems SO 2014 IEEE 53RD ANNUAL CONFERENCE ON DECISION AND CONTROL (CDC) LA English DT Proceedings Paper CT IEEE 53rd Annual Conference on Decision and Control (CDC) CY DEC 15-17, 2014 CL Los Angeles, CA SP IEEE, MathWorks, Springer, Altair, dSPACE, Journal Franklin Inst, Soc Ind & Appl Math, United Technologies Res Ctr, Wolfram, EBSCO Informat Serv, Inst Engn & Technol, Now, Taylor & Francis, Cogent Engn ID AC AB In microgrids that are predominantly resistive, real and reactive power can be controlled by implementation of voltage and frequency droop laws respectively. However, the variable frequency displayed by such a system complicates analysis such that design approaches rely on approximations and linearized models. In this work, we present a modified form of droop control where only the voltage versus real power relationship is upheld and the frequency is held constant. Since the frequency is not explicitly controlled and the reactive power is not measured, the controller can be simplified. In such a setting, the only assumption we make is that all inverters have access to a common time-reference. Because fixed frequency operation is enforced by design, a variety of analytical tools can be leveraged to formulate a comprehensive analytical framework which facilitates a precise design methodology. In particular, closed-form expressions on the output current phase differences are obtained which yield practical selection guidelines on the voltage-power droop gains such that reactive flows between inverters are kept small. As a corollary, it is demonstrated that there are no reactive power flows in the presence of purely resistive loads. For the particular case of a single inverter, an almost exact solution describing the nonlinear dynamics of the inverter output voltage, current, and power are derived. Accompanying simulation results validate the analytical results and demonstrate the feasibility of the proposed control approach. C1 [Salapaka, Srinivasa] Univ Illinois, Mech Sci & Engn, Urbana, IL 61801 USA. [Johnson, Brian; Lundstrom, Blake] Natl Renewable Energy Lab, Golden, CO USA. [Johnson, Brian; Lundstrom, Blake] US DOE, NREL, Off Energy Efficiency & Renewable Energy, Alliance Sustainable Energy LLC, Washington, DC 20585 USA. [Kim, Sangsun; Collyer, Scott] Google Inc, Santa Clara, CA USA. [Salapaka, Murti] Univ Minnesota, Elect & Comp Engn, Minneapolis, MN 55455 USA. RP Salapaka, S (reprint author), Univ Illinois, Mech Sci & Engn, Urbana, IL 61801 USA. EM salapakas@google.com; brian.johnson@nrel.gov; blake.lundstrom@nrel.gov; sskim@google.com; scollyer@google.com; salapakam@google.com NR 12 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4673-6090-6 PY 2014 BP 3246 EP 3251 PG 6 WC Automation & Control Systems SC Automation & Control Systems GA BE2TY UT WOS:000370073803066 ER PT J AU Brooks, J Goyal, S Subramany, R Lin, YS Middelkoop, T Arpan, L Carloni, L Barooah, P AF Brooks, Jonathan Goyal, Siddharth Subramany, Rahul Lin, Yashen Middelkoop, Timothy Arpan, Laura Carloni, Luca Barooah, Prabir GP IEEE TI An Experimental Investigation of Occupancy-Based Energy-Efficient Control of Commercial Building Indoor Climate SO 2014 IEEE 53RD ANNUAL CONFERENCE ON DECISION AND CONTROL (CDC) LA English DT Proceedings Paper CT IEEE 53rd Annual Conference on Decision and Control (CDC) CY DEC 15-17, 2014 CL Los Angeles, CA SP IEEE, MathWorks, Springer, Altair, dSPACE, Journal Franklin Inst, Soc Ind & Appl Math, United Technologies Res Ctr, Wolfram, EBSCO Informat Serv, Inst Engn & Technol, Now, Taylor & Francis, Cogent Engn ID PERFORMANCE; COMPLEXITY AB We present results from a week-long experimental evaluation of a scalable control algorithm for a commercial building heating, ventilation, and air-conditioning (HVAC) system. The experiments showed that the controller resulted in 37% energy savings without sacrificing indoor climate. In contrast to prior work that reports energy savings without a careful measure of the effect on indoor climate, we verify that the controller achieves the energy efficiency improvements without any adverse effect on the indoor climate compared to the building's baseline controller. This is established from measurements of a host of environmental variables and analysis of before-after occupant survey results. We present a complete system to retrofit existing buildings including the control algorithm and the supporting execution platform which includes the deployment of a wireless sensor network. Results show that there is a large variation in energy savings from zone to zone, which indicates that estimating energy savings potential of novel HVAC control systems is not trivial even from experiments-something that prior work with uniformly positive messages did not emphasize. C1 [Brooks, Jonathan; Lin, Yashen; Barooah, Prabir] Univ Florida, MAE Dept, Gainesville, FL 32611 USA. [Goyal, Siddharth] PNNL, Richland, WA USA. [Subramany, Rahul] Lutron Elec Inc, Coopersburg, PA USA. [Middelkoop, Timothy] Univ Missouri, ISSE Dept, Columbia, MO 65211 USA. [Carloni, Luca] Columbia Univ, CS Dept, New York, NY 10027 USA. RP Brooks, J (reprint author), Univ Florida, MAE Dept, Gainesville, FL 32611 USA. EM JonathanBrooksUF@gmail.com NR 16 TC 2 Z9 2 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4673-6090-6 PY 2014 BP 5680 EP 5685 PG 6 WC Automation & Control Systems SC Automation & Control Systems GA BE2TY UT WOS:000370073805136 ER PT S AU Tang, W Jenkins, J Meyer, F Ross, R Kettimuthu, R Winkler, L Yang, X Lehman, T Desai, N AF Tang, Wei Jenkins, Jonathan Meyer, Folker Ross, Robert Kettimuthu, Rajkumar Winkler, Linda Yang, Xi Lehman, Thomas Desai, Narayan GP IEEE TI Data-Aware Resource Scheduling for Multicloud Workflows: A Fine-Grained Simulation Approach SO 2014 IEEE 6TH INTERNATIONAL CONFERENCE ON CLOUD COMPUTING TECHNOLOGY AND SCIENCE (CLOUDCOM) SE International Conference on Cloud Computing Technology and Science LA English DT Proceedings Paper CT 6th IEEE International Conference on Cloud Computing Technology and Science (CloudCom) CY DEC 15-18, 2014 CL Singapore, SINGAPORE SP IEEE, IEEE Comp Soc, Nanyang Technol Univ, A STAR Inst High Performance Comp, STC Cloud Comp, Cloud Comp Assoc, IEEE Cloud Comp, TCBIS, hp, FUJITSU, IEEE Cloud Comp Initiat, IEEE Comp Soc Cloud Comp Special Tech Comm, EEE Comp Soc Tech Comm Scalable Comp, IEEE Comp Soc Tech Comm Business Informat & Syst DE data-aware scheduling; resource management; scientific workflow; cloud computing AB Cloud infrastructures have seen increasing popularity for addressing the growing computational needs of today's scientific and engineering applications. However, resource management challenges exist in the elastic cloud environment, such as resource provisioning and task allocation, especially when data movement between multiple domains plays an important role. In this work, we study the impact of data-aware resource management and scheduling on scientific workflows in multicloud environments. We develop a workflow simulator based on a network simulation framework for fine-grained simulation for workflow computation and data movement. Using the workload traces from a production metagenomic data analysis service, we evaluate different resource scheduling mechanisms, including proposed data-aware scheduling policies under various resource and bandwidth configurations. The results of this work are expected to answer questions about how to provision computing resources for certain workloads efficiently and how to place tasks across multidomain clouds in order to reduce data movement costs for overall improved system performance. C1 [Tang, Wei; Jenkins, Jonathan; Meyer, Folker; Ross, Robert; Kettimuthu, Rajkumar; Winkler, Linda; Desai, Narayan] Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. [Yang, Xi; Lehman, Thomas] Univ Maryland, College Pk, MD 20742 USA. [Desai, Narayan] Ericsson, San Jose, CA USA. RP Tang, W (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM wtang@mcs.anl.gov; jekins@mcs.anl.gov; folker@mcs.anl.gov; rross@mcs.anl.gov; kettimut@mcs.anl.gov; winkler@mcs.anl.gov; maxyang@umd.edu; tlehman@umd.edu; narayan.desai@ericsson.com FU U.S. Department of Energy, Office of Science [DE-AC02-06CH11357] FX This work is supported by the U.S. Department of Energy, Office of Science, under Contract DE-AC02-06CH11357. NR 22 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2330-2194 BN 978-1-4799-4093-6 J9 INT CONF CLOUD COMP PY 2014 BP 887 EP 892 DI 10.1109/CloudCom.2014.19 PG 6 WC Computer Science, Information Systems; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BG9BB UT WOS:000392947000139 ER PT S AU Inman, J Grider, G Chen, HB AF Inman, Jeff Grider, Gary Chen, Hsing-Bung BE Kesselman, C TI Cost of Tape versus Disk for Archival Storage SO 2014 IEEE 7TH INTERNATIONAL CONFERENCE ON CLOUD COMPUTING (CLOUD) SE IEEE International Conference on Cloud Computing LA English DT Proceedings Paper CT 7th IEEE International Conference on Cloud Computing (CLOUD) CY JUN 27-JUL 02, 2014 CL Anchorage, AK SP IEEE, IEEE Comp Soc DE cost; linear-optimization; erasure-code; tape; archive; disk; cloud AB For archiving large datasets in high-performance computing facilities, tape technology has a long history of providing inexpensive capacity. However, as the memory-size of supercomputers continues to grow geometrically, the cost of tape bandwidth is becoming more important. The projected costs for tape-drives, robotics, and maintenance, are creating challenges for tape-based archives. The advent of erasure-coded object storage, driven by the "cloud storage" industry, might make it practical to implement archives using disks, or hybrid disk-and-tape systems. We used linear optimization techniques to investigate when and how this transition might best be made, taking into consideration our significant investment in tape technology. Our models introduce a technique to systematically relax constraints on the relationship between tape-capacity and tape-bandwidth, which governs a trade-off between cost and performance. We ran parameter studies that support some preliminary conclusions about paths forward for archive infrastructure at LANL. C1 [Inman, Jeff; Grider, Gary; Chen, Hsing-Bung] Los Alamos Natl Lab, High Performance Comp, Los Alamos, NM 87544 USA. RP Inman, J (reprint author), Los Alamos Natl Lab, High Performance Comp, Los Alamos, NM 87544 USA. FU US Dept. of Defense FX This work was supported by funding from the US Dept. of Defense. We thank Bob Darlington, Parks Fields, Kyle Lamb, Ben McLelland, and Richard Strelitz, for helpful conversations at LANL. Thanks to Mark Steidel of Gurobi for help with licensing arrangements. 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 SN 2159-6182 BN 978-1-4799-5063-8 J9 IEEE INT CONF CLOUD PY 2014 BP 208 EP 215 DI 10.1109/CLOUD.2014.37 PG 8 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Computer Science, Theory & Methods SC Computer Science GA BG9AZ UT WOS:000392940500027 ER PT J AU Nicolae, B Riteau, P Keahey, K AF Nicolae, Bogdan Riteau, Pierre Keahey, Kate GP IEEE TI Transparent Throughput Elasticity for IaaS Cloud Storage Using Guest-Side Block-Level Caching SO 2014 IEEE/ACM 7TH INTERNATIONAL CONFERENCE ON UTILITY AND CLOUD COMPUTING (UCC) LA English DT Proceedings Paper CT IEEE/ACM 7th International Conference on Utility and Cloud Computing (UCC) CY DEC 08-11, 2014 CL London, UNITED KINGDOM SP IEEE, IEEE Comp Soc, ACM, TCSC IEEE, Sigarch DE cloud computing; storage elasticity; adaptive I/O; virtual disk; block-level caching AB Storage elasticity on IaaS clouds is a crucial feature in the age of data-intensive computing. However, the traditional provisioning model of leveraging virtual disks of fixed capacity and performance characteristics has limited ability to match the increasingly dynamic nature of I/O application requirements. This mismatch is particularly problematic in the context of scientific applications that interleave periods of I/O inactivity with I/O intensive bursts. In this context, overprovisioning for best performance during peaks leads to significant extra costs because of unnecessarily tied-up resources, while any other trade-off leads to performance loss. This paper provides a transparent solution that automatically boosts I/O bandwidth during peaks for underlying virtual disks, effectively avoiding overprovisioning without performance loss. Our proposal relies on the idea of leveraging short-lived virtual disks of better performance characteristics (and thus more expensive) to act during peaks as a caching layer for the persistent virtual disks where the application data is stored. We show how this idea can be achieved efficiently at the block-device level, using a caching mechanism that leverages iterative behavior and learns from past experience. We demonstrate the benefits of our proposal both for microbenchmarks and for two real-life applications using large-scale experiments. C1 [Nicolae, Bogdan] IBM Res, Dublin, Ireland. [Riteau, Pierre] Univ Chicago, Chicago, IL 60637 USA. [Keahey, Kate] Argonne Natl Lab, Argonne, IL 60439 USA. RP Nicolae, B (reprint author), IBM Res, Dublin, Ireland. EM bogdan.nicolae@ie.ibm.com; priteau@uchicago.edu; keahey@mcs.anl.gov NR 27 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7881-6 PY 2014 BP 186 EP 195 PG 10 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF3NE UT WOS:000380558700020 ER PT J AU Leva, A Mastrandrea, D Bonvini, M Papadopoulos, AV AF Leva, Alberto Mastrandrea, Daniele Bonvini, Marco Papadopoulos, Alessandro Vittorio GP IEEE TI Object-Oriented Modelling and Simulation of Air Flow in Data Centres Based on a Quasi-3D Approach for Energy Optimisation SO 2014 IEEE/ACM 7TH INTERNATIONAL CONFERENCE ON UTILITY AND CLOUD COMPUTING (UCC) LA English DT Proceedings Paper CT IEEE/ACM 7th International Conference on Utility and Cloud Computing (UCC) CY DEC 08-11, 2014 CL London, UNITED KINGDOM SP IEEE, IEEE Comp Soc, ACM, TCSC IEEE, Sigarch DE Data Centres; Energy Optimisation; Object-Oriented Modelling and Simulation AB Cloud computing has recently received considerable attention, as a promising approach for delivering ICT services by improving the utilisation of data centre resources. On the other hand, the increased usage of ICT, jointly with the increased cost of energy, make designing and managing data centres with energy efficient strategies a crucial and strategical problem. In the literature there are many studies based on Computational Fluid Dynamics (CFD) simulation models. While the obtained results are usually very reliable and accurate, the massive use of such models for control design require a large amount of time due to their computational complexity and scarce flexibility. In addition, CFD models are usually quite sensitive to any kind of change to the operating conditions, e.g. when varying the considered load balancing algorithm. In this paper, we propose a modelling and simulation framework suited for control design, that is able to simulate both heating and energy phenomena, and different load balancing strategies in a data centre. The purpose of this work is to provide a tool to perform energy-efficiency targeted studies, providing accurate and reliable results. C1 [Leva, Alberto; Mastrandrea, Daniele] Politecn Milan, DEIB, Milan, Italy. [Bonvini, Marco] Lawrence Berkeley Natl Lab, Berkeley, CA USA. [Papadopoulos, Alessandro Vittorio] Lund Univ, Dept Automat Control, S-22100 Lund, Sweden. RP Leva, A (reprint author), Politecn Milan, DEIB, Milan, Italy. EM alberto.leva@polimi.it; MBonvini@lbl.gov; alessandro.papadopoulos@control.lth.se OI Papadopoulos, Alessandro Vittorio/0000-0002-1364-8127 NR 30 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7881-6 PY 2014 BP 554 EP 559 PG 6 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF3NE UT WOS:000380558700078 ER PT J AU Kim, H Timm, SC AF Kim, Hyunwoo Timm, Steven C. GP IEEE TI X.509 Authentication/Authorization in FermiCloud SO 2014 IEEE/ACM 7TH INTERNATIONAL CONFERENCE ON UTILITY AND CLOUD COMPUTING (UCC) LA English DT Proceedings Paper CT IEEE/ACM 7th International Conference on Utility and Cloud Computing (UCC) CY DEC 08-11, 2014 CL London, UNITED KINGDOM SP IEEE, IEEE Comp Soc, ACM, TCSC IEEE, Sigarch DE Cloud; X.509; Authentication; Authorization; FermiCloud AB We present a summary of how X.509 authentication and authorization are used with OpenNebula in FermiCloud. We also describe a history of why the X.509 authentication was needed in FermiCloud, and review X.509 authorization options, both internal and external to OpenNebula. We show how these options can be and have been used to successfully run scientific workflows on federated clouds, which include OpenNebula on FermiCloud and Amazon Web Services as well as other community clouds. We also outline federation options being used by other commercial and open-source clouds and cloud research projects. C1 [Kim, Hyunwoo; Timm, Steven C.] Fermilab Natl Accelerator Lab, Div Comp Sci, POB 500, Batavia, IL 60510 USA. RP Kim, H (reprint author), Fermilab Natl Accelerator Lab, Div Comp Sci, POB 500, Batavia, IL 60510 USA. EM hyunwoo@fnal.gov; timm@fnal.go 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 978-1-4799-7881-6 PY 2014 BP 732 EP 737 PG 6 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF3NE UT WOS:000380558700112 ER PT J AU Diao, RS Makarov, YV Samaan, N Kujala, B AF Diao, Ruisheng Makarov, Yuri V. Samaan, Nader Kujala, Ben GP IEEE TI A Methodology to Analyze the Impact of 30-Minute Wind Scheduling on Load-Following Requirements SO 2014 IEEE CONFERENCE ON TECHNOLOGIES FOR SUSTAINABILITY (SUSTECH) LA English DT Proceedings Paper CT SusTech Ann IEEE Conference Technologies Sustainability CY JUL 24-26, 2014 CL Portland, OR SP IEEE Oregon Sect, REGION 6, IEEE USA, IEEE CONSUMER ELECT SOC, IEEE SOC SOCIAL IMPLICATIONS TECHNOLOGY DE 30-min scheduling; balancing requirements; load following; renewable integration; wind forecast error AB In this paper, a new method is proposed to investigate the impact of 30-min wind transfers between balancing authorities (BAs) on balancing requirements. The main idea is that if the wind energy transfer from a source BA could be scheduled every half an hour compared to the traditional hourly schedule, it would make the schedule follow its net load more closely. The load-following component is calculated as: (a) the difference between the net load and modified schedule in the source BA, and (b) the difference between modified net load and unchanged hourly schedule in the sink BA. This new method is tested on a few BAs in the Pacific Northwest with source BAs sending renewable and sink BAs receiving renewables. Simulated load following (upward and downward) requirements with the proposed 30-min schedules are compared with the results obtained with all generators scheduled on an hourly basis. The proposed method can effectively help utilities better understand the impact of 30-minute scheduling and make better business decisions. C1 [Diao, Ruisheng; Makarov, Yuri V.; Samaan, Nader] Pacific Northwest Natl Lab, Elect Infrastruct & Bldg Div, Richland, WA 99354 USA. [Kujala, Ben] Northwest Power & Conservat Council, Portland, OR USA. RP Diao, RS (reprint author), Pacific Northwest Natl Lab, Elect Infrastruct & Bldg Div, Richland, WA 99354 USA. EM Ruisheng.Diao@pnnl.gov; Yuri.Makarov@pnnl.gov; Nader.Samaan@pnnl.gov; BKujala@NWCouncil.org 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 BN 978-1-4799-5238-0 PY 2014 PG 5 WC GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY SC Science & Technology - Other Topics GA BF2LM UT WOS:000380478100016 ER PT J AU Makhmalbaf, A Fuller, J Srivastava, V Ciraci, S Daily, J AF Makhmalbaf, Atefe Fuller, Jason Srivastava, Viraj Ciraci, Selim Daily, Jeff GP IEEE TI Co-Simulation of Detailed Whole Building with the Power System to Study Smart Grid Applications SO 2014 IEEE CONFERENCE ON TECHNOLOGIES FOR SUSTAINABILITY (SUSTECH) LA English DT Proceedings Paper CT SusTech Ann IEEE Conference Technologies Sustainability CY JUL 24-26, 2014 CL Portland, OR SP IEEE Oregon Sect, REGION 6, IEEE USA, IEEE CONSUMER ELECT SOC, IEEE SOC SOCIAL IMPLICATIONS TECHNOLOGY ID STABILITY AB Modernization of the power system in a way that ensures a sustainable energy system is arguably one of the most pressing concerns of our time. Buildings are important components in the power system. First, they are the main consumers of electricity and secondly, they do not have constant energy demand. Conventionally, electricity has been difficult to store and should be consumed as it is generated. Therefore, maintaining the demand and supply is critical in the power system. However, to reduce the complexity of power models, buildings (i.e., end-use loads) are traditionally modeled and represented as aggregated "dumb" nodes in the power system. This means we lack effective detailed whole building energy models that can support requirements and emerging technologies of the smart power grid. To gain greater insight into the relationship between building energy demand and power system performance, it is important to constitute a co-simulation framework to support detailed building energy modeling and simulation within the power system to study capabilities promised by the modern power grid. This paper discusses ongoing work at Pacific Northwest National Laboratory and presents underlying tools and framework needed to enable co-simulation of building, building energy systems and their control in the power system to study applications such as demand response, grid-based HVAC control, and deployment of buildings for ancillary services. The optimal goal is to develop an integrated modeling and simulation platform that is flexible, reusable, and scalable. Results of this work will contribute to future building and power system studies, especially those related to the integrated 'smart grid'. Results are also expected to advance power resiliency and local (micro) scale grid studies where several building and renewable energy systems transact energy directly. This paper also reviews some applications that can be supported and studied using the framework introduced to understand their implications before they can be successfully implemented in the power system. C1 [Makhmalbaf, Atefe; Fuller, Jason; Srivastava, Viraj; Ciraci, Selim; Daily, Jeff] Pacific Northwest Natl Lab, Richland, WA 99354 USA. RP Makhmalbaf, A (reprint author), Pacific Northwest Natl Lab, Richland, WA 99354 USA. EM atefe.makhmalbaf@pnnl.gov RI Fuller, Jason/C-9951-2014 OI Fuller, Jason/0000-0002-0462-0093 NR 26 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5238-0 PY 2014 PG 7 WC GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY SC Science & Technology - Other Topics GA BF2LM UT WOS:000380478100034 ER PT J AU Nguyen, TB Samaan, N Jin, CL AF Nguyen, Tony B. Samaan, Nader Jin, Chunlian GP IEEE TI Evaluation of Production Cost Savings from Consolidation of Balancing Authorities in the US Western Interconnection under High Wind and Solar Penetration SO 2014 IEEE CONFERENCE ON TECHNOLOGIES FOR SUSTAINABILITY (SUSTECH) LA English DT Proceedings Paper CT SusTech Ann IEEE Conference Technologies Sustainability CY JUL 24-26, 2014 CL Portland, OR SP IEEE Oregon Sect, REGION 6, IEEE USA, IEEE CONSUMER ELECT SOC, IEEE SOC SOCIAL IMPLICATIONS TECHNOLOGY DE Balancing authorities; hurdle rates; economic dispatch; consolidation; production cost modeling; security constrained unit commitment AB This paper introduces a comprehensive analysis to quantify the potential savings in production cost due to consolidation of 32 U.S. Western Interconnection Balancing Authorities (BAs). Three simulation scenarios are developed: the current structure of Western Electricity Coordinating Council (WECC) BAs, full copper-sheet consolidation, and full consolidation with transmission congestion considered. The study uses a WECC Transmission Expansion Planning Policy Committee model that was developed for the year 2020. The model assumes 8% wind and 3% solar energy penetration as percentage of total WECC demand in 2020. Sensitivity analyses are carried out to assess the impact of transmission hurdle rates between WECC BAs on potential benefits. The study shows that savings ranging from $440 million (2.4% of total one-year production cost) to $610 million (3.2%) per year in thermal unit production cost due to consolidation can be achieved. The copper-sheet consolidation scenario shows a further savings of $240 million (1.4%) per year. C1 [Nguyen, Tony B.; Samaan, Nader] Pacific Northwest Natl Lab, Richland, WA 99352 USA. [Jin, Chunlian] ERCOT, Austin, TX USA. RP Nguyen, TB (reprint author), Pacific Northwest Natl Lab, Richland, WA 99352 USA. EM tony.nguyen@pnnl.gov; nader.samaan@pnnl.gov; Julie.Jin@ercot.com NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5238-0 PY 2014 PG 6 WC GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY SC Science & Technology - Other Topics GA BF2LM UT WOS:000380478100002 ER PT J AU Petersen, JM AF Petersen, Joseph M. GP IEEE TI Simulating Human Occupancy in an Experimental Laboratory Settings SO 2014 IEEE CONFERENCE ON TECHNOLOGIES FOR SUSTAINABILITY (SUSTECH) LA English DT Proceedings Paper CT SusTech Ann IEEE Conference Technologies Sustainability CY JUL 24-26, 2014 CL Portland, OR SP IEEE Oregon Sect, REGION 6, IEEE USA, IEEE CONSUMER ELECT SOC, IEEE SOC SOCIAL IMPLICATIONS TECHNOLOGY AB Energy conservation within a residential home is a primary focus for both home owners and power utilities throughout the country. Developing a methodology to model, detect, and measure human occupancy would allow for manipulation of electrical components within the home to conserve energy when no activity is present. An accurate ways to measure human occupancy is through detecting the latent and sensible heat that is generated by activities within the home. Industry and research facilities require the development of technology that appropriately models and detects human activity within a home. C1 [Petersen, Joseph M.] Washington State Univ, Sch Elect Engn & Comp Sci, Richland, WA 99354 USA. [Petersen, Joseph M.] Pacific Northwest Natl Lab, Energy Policy & Econ, Richland, WA USA. RP Petersen, JM (reprint author), Washington State Univ, Sch Elect Engn & Comp Sci, Richland, WA 99354 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5238-0 PY 2014 PG 4 WC GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY SC Science & Technology - Other Topics GA BF2LM UT WOS:000380478100035 ER PT S AU Whiting, M Cook, K Grinstein, G Liggett, K Cooper, M Fallon, J Morin, M AF Whiting, Mark Cook, Kristin Grinstein, Georges Liggett, Kristen Cooper, Michael Fallon, John Morin, Marc BE Chen, M Ebert, D North, C TI VAST Challenge 2014: The Kronos Incident SO 2014 IEEE CONFERENCE ON VISUAL ANALYTICS SCIENCE AND TECHNOLOGY (VAST) SE IEEE Conference on Visual Analytics Science and Technology LA English DT Proceedings Paper CT IEEE Conference Visual Analytics Sci Technology CY OCT 09-14, 2014 CL Paris, FRANCE SP Tableau Software, Inria, JCDecaux, cea, Fraunhofer IGD, Microsoft, AUTODESK, Paris Saclay Ctr Data Sci, here Maps for Life, Google, Kitware, nVIDIA, IledeFrance, IBM, SystemX, eDF, Adobe, National Security Agency Central Security Service, ALDECIS, DKRZ DE Visual analytics; human information interaction; sense making; evaluation; metrics; contest; H.5.2 [Information Interfaces & Presentations]: User Interfaces - Evaluation/methodology AB The 2014 IEEE Visual Analytics Science and Technology (VAST) Challenge presented researchers with a single fictitious scenario: the disappearance of staff members of the GASTech oil and gas company on location on the island of Kronos. A group named the Protectors of Kronos (POK) was the prime suspect in the disappearance. Three mini-challenges and a grand challenge were offered. Mini-challenge 1 included multiple types of text data for participants to provide a timeline of key events and characterize the POK, mini-challenge 2 focused on individuals' movement and financial data for participants to provide patterns of daily life, and mini-challenge 3 featured real-time streaming social media and emergency service data for participants to provide hostage and kidnapper information. The grand challenge asked the participants to integrate results and generate a synopsis of events. The VAST Challenge received 73 submissions from 13 countries. C1 [Whiting, Mark; Cook, Kristin; Cooper, Michael] Pacific Northwest Natl Lab, Richland, WA 99352 USA. [Grinstein, Georges; Fallon, John] Univ Massachusetts Lowell, Lowell, MA USA. [Liggett, Kristen] Air Force Res Lab, Wright Patterson AFB, OH USA. [Morin, Marc] Battelle Mem Inst, Columbus, OH USA. RP Whiting, M (reprint author), Pacific Northwest Natl Lab, Richland, WA 99352 USA. EM mark.whiting@pnnl.gov; kris.cook@pnnl.gov; grinstein@cs.uml.edu; kristen.liggett@us.af.mil; michael.cooper@pnnl.gov; john_fallon@student.uml.edu; MorinM@battelle.org NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2325-9442 BN 978-1-4799-6227-3 J9 IEEE CONF VIS ANAL PY 2014 BP 295 EP 300 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BF2JW UT WOS:000380474000061 ER PT J AU Ghatikar, G Zuber, J Koch, E Bienert, R AF Ghatikar, Girish Zuber, Jim Koch, Ed Bienert, Rolf GP IEEE TI Smart Grid and Customer Transactions: The Unrealized Benefits of Conformance SO 2014 IEEE GREEN ENERGY AND SYSTEMS CONFERENCE (IGESC) LA English DT Proceedings Paper CT IEEE Green Energy and Systems Conference (IGESC) CY NOV 24-24, 2014 CL Long Beach, CA DE Smart Grid Transactions; Innovation Cycle; Open Standards; Interoperability; Conformance AB Smart Grid investments and research promise significant benefits to both customers and the grid. One major benefit is data and communications that enable customer-side resources to participate in electricity programs-i.e., transact with the electric grid. The U.S. Smart Grid activities and investments, which account for nearly three billion dollars in publicly documented expenses, build on interoperability standards activity. Standards interoperability for grid transactions can be viewed from two key interfaces-between (1) Smart Grid domain interfaces, and (2) customer-side resources and the electric grid. Conformance testing and certification is key to ensuring that standards are interoperable and secure. This paper describes the conformance development and certification process for a key communications standard-Open Automated Demand Response (OpenADR)-as an interface between customers' systems and electricity service providers, to enable demand response and price transactions. Through this process, we describe the benefits of conformance to support low-cost automated DR (AutoDR) and customer-side transactions within the distribution electric grid. The paper evaluates examples of applications and further developments for emerging transactive energy concepts that can be used to scale existing systems and to leverage the investments and support compliance to any building codes and appliance standards. The conformance process can be the key to realizing interoperability benefits and market acceptance. Conformance is also a key to enabling native DR and price transaction capabilities in customers' systems; a feature that can be replicated for diffusion and can lower DR technology costs by a significant margin. C1 [Ghatikar, Girish] Lawrence Berkeley Natl Lab, Grid Integrat, Berkeley, CA 94720 USA. [Zuber, Jim] QualityLogic Inc, Simi Valley, CA 93065 USA. [Koch, Ed] Honeywell Bldg Solut, Golden Valley, MN 55422 USA. [Bienert, Rolf] OpenADR Alliance, Morgan Hill, CA 95037 USA. RP Ghatikar, G (reprint author), Lawrence Berkeley Natl Lab, Grid Integrat, Berkeley, CA 94720 USA. NR 17 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-7333-0 PY 2014 BP 7 EP 14 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA BF2HA UT WOS:000380466900002 ER PT S AU Hukerikar, S Teranishi, K Diniz, PC Lucas, RF AF Hukerikar, Saurabh Teranishi, Keita Diniz, Pedro C. Lucas, Robert F. GP IEEE TI An Evaluation of Lazy Fault Detection based on Adaptive Redundant Multithreading SO 2014 IEEE HIGH PERFORMANCE EXTREME COMPUTING CONFERENCE (HPEC) SE IEEE High Performance Extreme Computing Conference LA English DT Proceedings Paper CT 2014 IEEE High Performance Extreme Computing Conference (HPEC CY SEP 11-11, 2014 CL Avenue Waltham, MA AB The challenge of resilience for High Performance Computing applications is significant for future extreme scale systems. These systems will experience unprecedented rates of faults and errors as they will be constructed from massive numbers of components that are inherently less reliable than those available today. While the use of redundant computing can provide detection and possible correction of errors, its system-wide use in future extreme-scale HPC systems will incur considerable overheads to application performance. In this paper, we present a framework that provides application level fault detection based on redundant multithreading. In previous work, we demonstrated an adaptive approach based on a language level directive. The computation contained in the programmer directive is executed by duplicate threads. In concert with a runtime system, the redundant multithreading is enabled opportunistically to provide fault detection at more reasonable overheads to application performance. The lazy fault detection approach presented in this work seeks to further optimize the use of redundancy by prioritizing the application's primary computation over the fault detection. Our approach relaxes the requirement that the redundant threads synchronize and compare results immediately. We show that lazy error detection is feasible and yields lower time to solution over adaptive RMT for a range of scientific computational kernels. We also explore a thread-to-core assignment strategy that seeks to reduce the interference between the redundant threads. C1 [Hukerikar, Saurabh; Diniz, Pedro C.; Lucas, Robert F.] Univ Southern Calif, Inst Informat Sci, Marina Del Rey, CA 90292 USA. [Teranishi, Keita] Sandia Natl Labs, Livermore, CA USA. RP Hukerikar, S (reprint author), Univ Southern Calif, Inst Informat Sci, Marina Del Rey, CA 90292 USA. EM saurabh@isi.edu; knteran@sandia.gov; pedro@isi.edu; rflucas@isi.edu NR 18 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2377-6943 BN 978-1-4799-6233-4 J9 IEEE HIGH PERF EXTR PY 2014 PG 6 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2LZ UT WOS:000380479300057 ER PT S AU Tung, TH Shambayati, A Deutschbein, C Hoffmann, H Chien, AA AF Tung Thanh-Hoang Shambayati, Amirali Deutschbein, Calvin Hoffmann, Henry Chien, Andrew A. GP IEEE TI Performance and Energy Limits of a Processor-integrated FFT Accelerator SO 2014 IEEE HIGH PERFORMANCE EXTREME COMPUTING CONFERENCE (HPEC) SE IEEE High Performance Extreme Computing Conference LA English DT Proceedings Paper CT 2014 IEEE High Performance Extreme Computing Conference (HPEC CY SEP 11-11, 2014 CL Avenue Waltham, MA AB Accelerators have long been used to improve the performance and energy efficiency of embedded signal processing systems relying on Fast Fourier Transforms (FFTs). We explore the benefits of processor-integrated FFT accelerators, characterizing their performance and energy efficiency for current and future memory architectures. First, we consider designs that deeply integrate an FFT accelerator into a simple 5-stage RISC pipeline and evaluate the performance and energy efficiency for a 32 nm process. Our results indicate that a 64-point processor-integrated FFT accelerator alone can increase performance for a 4K/32kpoint 1D-FFT by 7/4-fold respectively. In term of energy efficiency, our 64-point FFT accelerator increases it at least 4-fold. Second, since memory performance is a critical constraint, we evaluate system configuration with 3D-stacked DRAM systems. Our results indicate that energy efficiency bottlenecks can be alleviated, as the 3D-stacked memory reduces energy by nearly 14-fold. When combined with our FFT accelerator, overall energy efficiency for 4k and 32k-point FFTs increases 86-fold and 70-fold respectively. Prospectively, with addition of a data layout transformation engine, cycle count and energy for the data transpose phase can be reduced 10x. Such a step would increase the accelerator benefit at least 10-fold in energy for DDR3 and more than 100-fold in 3D-stacked memory system. C1 [Tung Thanh-Hoang; Shambayati, Amirali; Deutschbein, Calvin; Hoffmann, Henry; Chien, Andrew A.] Univ Chicago, Dept Comp Sci, Chicago, IL 60637 USA. [Chien, Andrew A.] Argonne Natl Lab, Chicago, IL USA. RP Tung, TH (reprint author), Univ Chicago, Dept Comp Sci, Chicago, IL 60637 USA. EM hoangt@cs.uchicago.edu; amirali@cs.uchicago.edu; calvin.excalibur@gmail.com; hankhoffmann@cs.uchicago.edu; achien@cs.uchicago.edu NR 37 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2377-6943 BN 978-1-4799-6233-4 J9 IEEE HIGH PERF EXTR PY 2014 PG 6 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2LZ UT WOS:000380479300009 ER PT S AU Ufimtsev, V Bhowmick, S Rajamanickam, S AF Ufimtsev, Vladimir Bhowmick, Sanjukta Rajamanickam, Sivasankaran GP IEEE TI Building Blocks for Graph Based Network Analysis SO 2014 IEEE HIGH PERFORMANCE EXTREME COMPUTING CONFERENCE (HPEC) SE IEEE High Performance Extreme Computing Conference LA English DT Proceedings Paper CT 2014 IEEE High Performance Extreme Computing Conference (HPEC CY SEP 11-11, 2014 CL Avenue Waltham, MA ID PROTEIN NETWORKS; CENTRALITY AB Network analysis using graph abstractions is a powerful tool for studying complex systems. While there are multiple libraries for both graph operations in general and network analysis algorithms in particular, there is no components based standardization of both of these key set of operations. We propose a framework that abstracts the data stuctures, architecture, programming models for the graph algorithms underneath a very simple component based interface. We also build on these graph abstractions to provide a layer of abstraction that are key for network analysis. A reference implementation of the abstractions and its performance is also demonstrated using a new library - ESSENS. C1 [Ufimtsev, Vladimir; Bhowmick, Sanjukta] Univ Nebraska, Dept Comp Sci, Omaha, NE 68182 USA. [Rajamanickam, Sivasankaran] Sandia Natl Labs, Scalable Algorithms Dept, Livermore, CA 94550 USA. RP Ufimtsev, V (reprint author), Univ Nebraska, Dept Comp Sci, Omaha, NE 68182 USA. EM vufimtsev@unomaha.edu; sbhowmick@unomaha.edu; srajama@sandia.gov NR 30 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2377-6943 BN 978-1-4799-6233-4 J9 IEEE HIGH PERF EXTR PY 2014 PG 6 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2LZ UT WOS:000380479300040 ER PT S AU Wolf, MM Miller, BA AF Wolf, Michael M. Miller, Benjamin A. GP IEEE TI Sparse Matrix Partitioning for Parallel Eigenanalysis of Large Static and Dynamic Graphs SO 2014 IEEE HIGH PERFORMANCE EXTREME COMPUTING CONFERENCE (HPEC) SE IEEE High Performance Extreme Computing Conference LA English DT Proceedings Paper CT 2014 IEEE High Performance Extreme Computing Conference (HPEC CY SEP 11-11, 2014 CL Avenue Waltham, MA AB Numerous applications focus on the analysis of entities and the connections between them, and such data are naturally represented as graphs. In particular, the detection of a small subset of vertices with anomalous coordinated connectivity is of broad interest, for problems such as detecting strange traffic in a computer network or unknown communities in a social network. These problems become more difficult as the background graph grows larger and noisier and the coordination patterns become more subtle. In this paper, we discuss the computational challenges of a statistical framework designed to address this cross-mission challenge. The statistical framework is based on spectral analysis of the graph data, and three partitioning methods are evaluated for computing the principal eigenvector of the graph's residuals matrix. While a standard onedimensional partitioning technique enables this computation for up to four billion vertices, the communication overhead prevents this method from being used for even larger graphs. Recent two-dimensional partitioning methods are shown to have much more favorable scaling properties. A data-dependent partitioning method, which has the best scaling performance, is also shown to improve computation time even as a graph changes over time, allowing amortization of the upfront cost. C1 [Wolf, Michael M.; Miller, Benjamin A.] MIT, Lincoln Lab, Lexington, MA 02420 USA. RP Wolf, MM (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. EM mmwolf@sandia.gov; bamiller@ll.mit.edu NR 12 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2377-6943 BN 978-1-4799-6233-4 J9 IEEE HIGH PERF EXTR PY 2014 PG 6 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2LZ UT WOS:000380479300013 ER PT J AU Zhao, DF Zhang, Z Zhou, XB Li, TL Wang, K Kimpe, D Carns, P Ross, R Raicu, I AF Zhao, Dongfang Zhang, Zhao Zhou, Xiaobing Li, Tonglin Wang, Ke Kimpe, Dries Carns, Philip Ross, Robert Raicu, Ioan GP IEEE BE Lin, J Hu, XH Chang, W Nambiar, R Aggarwal, C Cercone, N Honavar, V Huan, J Mobasher, B Pyne, S TI FusionFS: Toward Supporting Data-Intensive Scientific Applications on Extreme-Scale High-Performance Computing Systems SO 2014 IEEE INTERNATIONAL CONFERENCE ON BIG DATA (BIG DATA) LA English DT Proceedings Paper CT IEEE International Conference on Big Data CY OCT 27-30, 2014 CL Washington, DC SP IEEE, IEEE Comp Soc, ELSEVIER, Natl Sci Fdn, CISCO, CCF AB State-of-the-art, yet decades-old, architecture of high-performance computing systems has its compute and storage resources separated. It thus is limited for modern data-intensive scientific applications because every I/O needs to be transferred via the network between the compute and storage resources. In this paper we propose an architecture that hss a distributed storage layer local to the compute nodes. This layer is responsible for most of the I/O operations and saves extreme amounts of data movement between compute and storage resources. We have designed and implemented a system prototype of this architecture-which we call the FusionFS distributed file system-to support metadata-intensive and write-intensive operations, both of which are critical to the I/O performance of scientific applications. FusionFS has been deployed and evaluated on up to 16K compute nodes of an IBM Blue Gene/P supercomputer, showing more than an order of magnitude performance improvement over other popular file systems such as GPFS, PVFS, and HDFS. C1 [Zhao, Dongfang; Li, Tonglin; Wang, Ke; Raicu, Ioan] IIT, Chicago, IL 60616 USA. [Zhang, Zhao] Univ Calif Berkeley, Berkeley, CA USA. [Zhou, Xiaobing] Hortonworks Inc, Santa Clara, CA USA. [Zhao, Dongfang; Kimpe, Dries; Carns, Philip; Ross, Robert; Raicu, Ioan] Argonne Natl Lab, Argonne, IL 60439 USA. RP Zhao, DF (reprint author), IIT, Chicago, IL 60616 USA. EM dzhao8@iit.edu; zhaozhang@eecs.berkeley.edu; xzhou@hortonworks.com; tli33@hawk.iit.edu; kwang22@hawk.iit.edu; dkimpe@mcs.anl.gov; carns@mcs.anl.gov; rross@mcs.anl.gov; iraicu@cs.iit.edu NR 45 TC 10 Z9 10 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5666-1 PY 2014 BP 61 EP 70 PG 10 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2FK UT WOS:000380462900012 ER PT J AU Wang, T Oral, S Wang, YD Settlemyer, B Atchley, S Yu, WK AF Wang, Teng Oral, Sarp Wang, Yandong Settlemyer, Brad Atchley, Scott Yu, Weikuan GP IEEE BE Lin, J Hu, XH Chang, W Nambiar, R Aggarwal, C Cercone, N Honavar, V Huan, J Mobasher, B Pyne, S TI BurstMem: A High-Performance Burst Buffer System for Scientific Applications SO 2014 IEEE INTERNATIONAL CONFERENCE ON BIG DATA (BIG DATA) LA English DT Proceedings Paper CT IEEE International Conference on Big Data CY OCT 27-30, 2014 CL Washington, DC SP IEEE, IEEE Comp Soc, ELSEVIER, Natl Sci Fdn, CISCO, CCF AB The growth of computing power on large-scale systems requires commensurate high-bandwidth I/O systems. Many parallel file systems are designed to provide fast sustainable I/O in response to applications' soaring requirements. To meet this need, a novel system is imperative to temporarily buffer the bursty I/O and gradually flush datasets to long-term parallel file systems. In this paper, we introduce the design of BurstMem, a high-performance burst buffer system. BurstMem provides a storage framework with efficient storage and communication management strategies. Our experiments demonstrate that BurstMem is able to speed up the I/O performance of scientific applications by up to 8.5x on leadership computer systems. C1 [Wang, Teng; Wang, Yandong; Yu, Weikuan] Auburn Univ, Auburn, AL 36849 USA. [Oral, Sarp; Settlemyer, Brad; Atchley, Scott] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Wang, T (reprint author), Auburn Univ, Auburn, AL 36849 USA. EM tzw0019@auburn.edu; oralhs@ornl.gov; wangyd@auburn.edu; settlemyerbw@ornl.gov; atchleyes@ornl.gov; wkyu@auburn.edu NR 30 TC 5 Z9 5 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5666-1 PY 2014 BP 71 EP 79 PG 9 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2FK UT WOS:000380462900013 ER PT J AU Wang, K Zhou, XB Li, TL Zhao, DF Lang, M Raicu, I AF Wang, Ke Zhou, Xiaobing Li, Tonglin Zhao, Dongfang Lang, Michael Raicu, Ioan GP IEEE BE Lin, J Hu, XH Chang, W Nambiar, R Aggarwal, C Cercone, N Honavar, V Huan, J Mobasher, B Pyne, S TI Optimizing Load Balancing and Data-Locality with Data-aware Scheduling SO 2014 IEEE INTERNATIONAL CONFERENCE ON BIG DATA (BIG DATA) LA English DT Proceedings Paper CT IEEE International Conference on Big Data CY OCT 27-30, 2014 CL Washington, DC SP IEEE, IEEE Comp Soc, ELSEVIER, Natl Sci Fdn, CISCO, CCF DE data-intensive computing; data-aware scheduling; work stealing; key-value stores; many-task computing AB Load balancing techniques (e.g. work stealing) are important to obtain the best performance for distributed task scheduling systems that have multiple schedulers making scheduling decisions. In work stealing, tasks are randomly migrated from heavy-loaded schedulers to idle ones. However, for data-intensive applications where tasks are dependent and task execution involves processing a large amount of data, migrating tasks blindly yields poor data-locality and incurs significant data-transferring overhead. This work improves work stealing by using both dedicated and shared queues. Tasks are organized in queues based on task data size and location. We implement our technique in MATRIX, a distributed task scheduler for many-task computing. We leverage distributed key-value store to organize and scale the task metadata, task dependency, and data-locality. We evaluate the improved work stealing technique with both applications and micro-benchmarks structured as direct acyclic graphs. Results show that the proposed data-aware work stealing technique performs well. C1 [Wang, Ke; Li, Tonglin; Zhao, Dongfang; Raicu, Ioan] IIT, Chicago, IL 60616 USA. [Zhou, Xiaobing] Hortonworks Inc, Santa Clara, CA USA. [Lang, Michael] Los Alamos Natl Lab, Los Alamos, NM USA. [Raicu, Ioan] Argonne Natl Lab, Argonne, IL 60439 USA. RP Wang, K (reprint author), IIT, Chicago, IL 60616 USA. EM kwang22@hawk.iit.edu; xzhou@hortonworks.com; tli13@hawk.iit.edu; dzhao8@hawk.iit.edu; mlang@lanl.gov; iraicu@cs.iit.edu NR 52 TC 14 Z9 14 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5666-1 PY 2014 BP 119 EP 128 PG 10 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2FK UT WOS:000380462900018 ER PT J AU Otstott, D Evans, N Ionkov, L Zhao, M Lang, M AF Otstott, Douglas Evans, Noah Ionkov, Latchesar Zhao, Ming Lang, Michael GP IEEE BE Lin, J Hu, XH Chang, W Nambiar, R Aggarwal, C Cercone, N Honavar, V Huan, J Mobasher, B Pyne, S TI Enabling Composite Applications through an Asynchronous Shared Memory Interface SO 2014 IEEE INTERNATIONAL CONFERENCE ON BIG DATA (BIG DATA) LA English DT Proceedings Paper CT IEEE International Conference on Big Data CY OCT 27-30, 2014 CL Washington, DC SP IEEE, IEEE Comp Soc, ELSEVIER, Natl Sci Fdn, CISCO, CCF DE shared memory; composite applications; operating systems; memory management; checkpoint AB In this work we address the growing need for mechanisms for intranode application composition. We provide a novel shared memory interface that allows composite applications, two or more coupled applications, to share internal data structures without blocking. This allows independent progress of the applications such that they can proceed in a parallel, overlapped fashion. Composite applications using in-node shared memory can reduce the amount of data to be communicated between nodes, allowing data reduction or analytics to be performed locally and in parallel. To validate our approach we implemented our solution in Linux and used two proxy-applications to demonstrate how applications can be coupled and compare the performance to a traditional solution. We also compared the impact of composite applications to the performance of their unmodified versions. Our solution incurs small overhead in HPC linux environments and significantly outperforms preexisting approaches. C1 [Otstott, Douglas; Zhao, Ming] Florida Int Univ, Sch Comp & Informat Sci, Miami, FL 33199 USA. [Evans, Noah; Ionkov, Latchesar; Lang, Michael] Los Alamos Natl Lab, Ultrascale Syst Res Ctr, Los Alamos, NM USA. RP Otstott, D (reprint author), Florida Int Univ, Sch Comp & Informat Sci, Miami, FL 33199 USA. EM dotst001@fiu.edu; noah.evans@gmail.com; lionkov@lanl.gov; mzhao@fiu.edu; mlang@lanl.gov NR 17 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5666-1 PY 2014 BP 219 EP 224 PG 6 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2FK UT WOS:000380462900034 ER PT J AU Zhao, DF Yin, J Qiao, K Raicu, I AF Zhao, Dongfang Yin, Jian Qiao, Kan Raicu, Ioan GP IEEE BE Lin, J Hu, XH Chang, W Nambiar, R Aggarwal, C Cercone, N Honavar, V Huan, J Mobasher, B Pyne, S TI Virtual Chunks: On Supporting Random Accesses to Scientific Data in Compressible Storage Systems SO 2014 IEEE INTERNATIONAL CONFERENCE ON BIG DATA (BIG DATA) LA English DT Proceedings Paper CT IEEE International Conference on Big Data CY OCT 27-30, 2014 CL Washington, DC SP IEEE, IEEE Comp Soc, ELSEVIER, Natl Sci Fdn, CISCO, CCF AB Data compression could ameliorate the I/O pressure of scientific applications on high-performance computing systems. Unfortunately, the conventional wisdom of naively applying data compression to the file or block brings the dilemma between efficient random accesses and high compression ratios. File-level compression can barely support efficient random accesses to the compressed data: any retrieval request need trigger the decompression from the beginning of the compressed file. Block-level compression provides flexible random accesses to the compressed data, but introduces extra overhead when applying the compressor to each every block that results in a degraded overall compression ratio. This paper introduces a concept called virtual chunks aiming to support efficient random accesses to the compressed scientific data without sacrificing its compression ratio. In essence, virtual chunks are logical blocks identified by appended references without breaking the physical continuity of the file content. These additional references allow the decompression to start from an arbitrary position (efficient random access), and retain the file's physical entirety to achieve high compression ratio on par with file-level compression. One potential concern of virtual chunks lies on its space overhead (from the additional references) that degrades the compression ratio, but our analytic study and experimental results demonstrate that such overhead is negligible. We have implemented virtual chunks in two forms: a middleware to the GPFS parallel file system, and a module in the FusionFS distributed file system. Large-scale evaluations on up to 1,024 cores showed that virtual chunks could help improve the I/O throughput by 2X speedup. C1 [Zhao, Dongfang; Qiao, Kan; Raicu, Ioan] IIT, Chicago, IL 60616 USA. [Zhao, Dongfang; Yin, Jian] Pacific Northwest Natl Lab, Richland, WA USA. [Qiao, Kan] Google Inc, Mountain View, CA USA. [Raicu, Ioan] Argonne Natl Lab, Argonne, IL 60439 USA. RP Zhao, DF (reprint author), IIT, Chicago, IL 60616 USA. EM dzhao8@iit.edu; jian.yin@pnnl.gov; kqiao@iit.edu; iraicu@cs.iit.edu NR 38 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5666-1 PY 2014 BP 231 EP 240 PG 10 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2FK UT WOS:000380462900036 ER PT J AU Dai, D Chen, Y Kimpe, D Ross, R AF Dai, Dong Chen, Yong Kimpe, Dries Ross, Rob GP IEEE BE Lin, J Hu, XH Chang, W Nambiar, R Aggarwal, C Cercone, N Honavar, V Huan, J Mobasher, B Pyne, S TI Provenance-Based Object Storage Prediction Scheme for Scientific Big Data Applications SO 2014 IEEE INTERNATIONAL CONFERENCE ON BIG DATA (BIG DATA) LA English DT Proceedings Paper CT IEEE International Conference on Big Data CY OCT 27-30, 2014 CL Washington, DC SP IEEE, IEEE Comp Soc, ELSEVIER, Natl Sci Fdn, CISCO, CCF AB Object storage has been increasingly adopted in high-performance computing for scientific, big data applications. With object storage, applications usually use object IDs, queries, or collections to identify the data instead of using files. Since the object store changes the way data is accessed in applications, it introduces new challenges for I/O prediction, which used to work based on interfile or intrafile pattern detection. The key challenge is that the inputs of object-based applications are no longer expressed as static file names: they become much more dynamic and unstable, hidden inside application logic. Traditional prediction strategies do not work well in such conditions. In this paper, we introduce the use of provenance information, which was collected for data management in high-performance computing systems, in order to build an accurate coarse-grained (object-level) input prediction. The prediction results can be preloaded into a burst buffer to accelerate future reads. To our best knowledge, this study is the first to use provenance information in object stores to predict application inputs. Evaluation results confirm the effectiveness and accuracy of our provenance-based prediction and show that the proposed prediction system is feasible for real-work deployment. C1 [Dai, Dong; Chen, Yong] Texas Tech Univ, Dept Comp Sci, Lubbock, TX 79409 USA. [Kimpe, Dries; Ross, Rob] Argonne Natl Lab, Math & Comp Sci Div, Argonne, IL 60439 USA. RP Dai, D (reprint author), Texas Tech Univ, Dept Comp Sci, Lubbock, TX 79409 USA. EM dong.dai@ttu.edu; yong.chen@ttu.edu; dkimpe@mcs.anl.gov; rross@mcs.anl.gov NR 28 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5666-1 PY 2014 BP 271 EP 280 PG 10 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2FK UT WOS:000380462900040 ER PT J AU Steed, CA Evans, KJ Harney, JF Jewell, BC Shipman, G Smith, BE Thornton, PE Williams, DN AF Steed, Chad A. Evans, Katherine J. Harney, John F. Jewell, Brian C. Shipman, Galen Smith, Brian E. Thornton, Peter E. Williams, Dean N. GP IEEE BE Lin, J Hu, XH Chang, W Nambiar, R Aggarwal, C Cercone, N Honavar, V Huan, J Mobasher, B Pyne, S TI Web-based Visual Analytics for Extreme Scale Climate Science SO 2014 IEEE INTERNATIONAL CONFERENCE ON BIG DATA (BIG DATA) LA English DT Proceedings Paper CT IEEE International Conference on Big Data CY OCT 27-30, 2014 CL Washington, DC SP IEEE, IEEE Comp Soc, ELSEVIER, Natl Sci Fdn, CISCO, CCF ID GOOGLE EARTH; VISUALIZATION; EXPLORATION AB In this paper, we introduce a Web-based visual analytics framework for democratizing advanced visualization and analysis capabilities pertinent to large-scale earth system simulations. We address significant limitations of present climate data analysis tools such as tightly coupled dependencies, inefficient data movements, complex user interfaces, and static visualizations. Our Web-based visual analytics framework removes critical barriers to the widespread accessibility and adoption of advanced scientific techniques. Using distributed connections to back-end diagnostics, we minimize data movements and leverage HPC platforms. We also mitigate system dependency issues by employing a RESTful interface. Our framework embraces the visual analytics paradigm via new visual navigation techniques for hierarchical parameter spaces, multi-scale representations, and interactive spatio-temporal data mining methods that retain details. Although generalizable to other science domains, the current work focuses on improving exploratory analysis of large-scale Community Land Model (CLM) and Community Atmosphere Model (CAM) simulations. C1 [Steed, Chad A.; Evans, Katherine J.; Harney, John F.; Jewell, Brian C.; Shipman, Galen; Smith, Brian E.; Thornton, Peter E.] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. [Williams, Dean N.] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Steed, CA (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM csteed@acm.org; evanskj@ornl.gov; harneyjf@ornl.gov; jewellbc@ornl.gov; gshipman@ornl.gov; smithbe@ornl.gov; thorntonpe@ornl.gov; williams13@llnl.gov NR 32 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5666-1 PY 2014 BP 383 EP 392 PG 10 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2FK UT WOS:000380462900053 ER PT J AU Slota, GM Madduri, K Rajamanickam, S AF Slota, George M. Madduri, Kamesh Rajamanickam, Sivasankaran GP IEEE BE Lin, J Hu, XH Chang, W Nambiar, R Aggarwal, C Cercone, N Honavar, V Huan, J Mobasher, B Pyne, S TI PULP: Scalable Multi-Objective Multi-Constraint Partitioning for Small-World Networks SO 2014 IEEE INTERNATIONAL CONFERENCE ON BIG DATA (BIG DATA) LA English DT Proceedings Paper CT IEEE International Conference on Big Data CY OCT 27-30, 2014 CL Washington, DC SP IEEE, IEEE Comp Soc, ELSEVIER, Natl Sci Fdn, CISCO, CCF AB We present PULP, a parallel and memory-efficient graph partitioning method specifically designed to partition low-diameter networks with skewed degree distributions. Graph partitioning is an important Big Data problem because it impacts the execution time and energy efficiency of graph analytics on distributed-memory platforms. Partitioning determines the in-memory layout of a graph, which affects locality, intertask load balance, communication time, and overall memory utilization of graph analytics. A novel feature of our method PULP (Partitioning using Label Propagation) is that it optimizes for multiple objective metrics simultaneously, while satisfying multiple partitioning constraints. Using our method, we are able to partition a web crawl with billions of edges on a single compute server in under a minute. For a collection of test graphs, we show that PULP uses 8-39x less memory than state-of-the-art partitioners and is up to 14.5x faster, on average, than alternate approaches (with 16-way parallelism). We also achieve better partitioning quality results for the multi-objective scenario. C1 [Slota, George M.; Madduri, Kamesh] Penn State Univ, Dept Comp Sci & Engn, University Pk, PA 16802 USA. [Rajamanickam, Sivasankaran] Sandia Natl Labs, Scalable Algorithms Dept, Albuquerque, NM 87185 USA. RP Slota, GM (reprint author), Penn State Univ, Dept Comp Sci & Engn, University Pk, PA 16802 USA. EM gms5016@cse.psu.edu; madduri@cse.psu.edu; srajama@sandia.gov NR 34 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5666-1 PY 2014 BP 481 EP 490 PG 10 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2FK UT WOS:000380462900063 ER PT J AU Yi, H Rasquin, M Fang, J Bolotnov, IA AF Yi, Hong Rasquin, Michel Fang, Jun Bolotnov, Igor A. GP IEEE BE Lin, J Hu, XH Chang, W Nambiar, R Aggarwal, C Cercone, N Honavar, V Huan, J Mobasher, B Pyne, S TI In-Situ Visualization and Computational Steering for Large-Scale Simulation of Turbulent Flows in Complex Geometries SO 2014 IEEE INTERNATIONAL CONFERENCE ON BIG DATA (BIG DATA) LA English DT Proceedings Paper CT IEEE International Conference on Big Data CY OCT 27-30, 2014 CL Washington, DC SP IEEE, IEEE Comp Soc, ELSEVIER, Natl Sci Fdn, CISCO, CCF AB Large-scale simulations conducted on supercomputers such as leadership-class computing facilities allow researchers to simulate and study complex problems with high fidelity, and thus have become indispensable in diverse areas of science and engineering. These high-fidelity simulations generate vast amount of data which is becoming more and more difficult to transform into knowledge using traditional visual analysis approaches. For instance, there are tremendous challenges in analyzing big data produced by high-fidelity simulations in order to gain meaningful insight into complex phenomena such as turbulent two-phase flows. The traditional workflow, which consists in conducting simulations on supercomputers and recording enormous raw simulation data to disk for further post-processing and visualization, is no longer a viable approach due to prohibitive cost of disk access and considerable amount of time spent on data transfer. Visual Analytics approaches for big data have to be researched and employed to address the problem of knowledge discovery from such large-scale simulations. One approach to tackle this issue is to couple a numerical simulation with in-situ visualization so that the post-processing and visualization occurs while the simulation is running. This in-situ approach minimizes data storage by extracting and visualizing important features of the data directly within the simulation without saving the raw data to disk. In addition, in-situ visualization allows users to steer the simulation by adjusting input parameters while the simulation is ongoing. In this paper, we present our approach for in-situ visualization of simulation data generated by massively parallel finite-element computational fluid dynamics solver (PHASTA) instrumented and linked with ParaView Catalyst. We demonstrate our in-situ visualization and simulation steering capability with a fully resolved turbulent flow through 2 x 2 reactor subchannel complex geometry. In addition, we present results from our in-situ visualization for turbulent flow simulations conducted on the supercomputers Cray XK7 "Titan" at Oak Ridge National Laboratory and IBM BlueGene/Q "Mira" at Argonne National Laboratory up to 32,768 cores and examine the overhead of insitu visualization and its effect on code performance. C1 [Yi, Hong] Univ N Carolina, Renaissance Comp Inst, Chapel Hill, NC 27517 USA. [Rasquin, Michel] Argonne Natl Lab, Argonne Leadership Comp Facil, Argonne, IL 60439 USA. [Rasquin, Michel] Univ Colorado, Dept Aerosp Engn, Boulder, CO 80309 USA. [Fang, Jun; Bolotnov, Igor A.] North Carolina State Univ, Dept Nucl Engn, Raleigh, NC 27695 USA. RP Yi, H (reprint author), Univ N Carolina, Renaissance Comp Inst, Chapel Hill, NC 27517 USA. EM hongyi@renci.org; mrasquin@alcf.anl.gov; jfang3@ncsu.edu; iabolotn@ncsu.edu NR 17 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5666-1 PY 2014 BP 567 EP 572 PG 6 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2FK UT WOS:000380462900073 ER PT J AU Ushizima, D Perciano, T Krishnan, H Loring, B Bale, H Parkinson, D Sethian, J AF Ushizima, Daniela Perciano, Talita Krishnan, Harinarayan Loring, Burlen Bale, Hrishikesh Parkinson, Dilworth Sethian, James GP IEEE BE Lin, J Hu, XH Chang, W Nambiar, R Aggarwal, C Cercone, N Honavar, V Huan, J Mobasher, B Pyne, S TI Structure Recognition from High Resolution Images of Ceramic Composites SO 2014 IEEE INTERNATIONAL CONFERENCE ON BIG DATA (BIG DATA) LA English DT Proceedings Paper CT IEEE International Conference on Big Data CY OCT 27-30, 2014 CL Washington, DC SP IEEE, IEEE Comp Soc, ELSEVIER, Natl Sci Fdn, CISCO, CCF DE Material Inspection; Fiber Detection; ImageJ/Fiji plug-in; GPU; OpenCL ID SEGMENTATION; MORPHOLOGY AB Fibers provide exceptional strength-to-weight ratio capabilities when woven into ceramic composites, transforming them into materials with exceptional resistance to high temperature, and high strength combined with improved fracture toughness. Microcracks are inevitable when the material is under strain, which can be imaged using synchrotron X-ray computed micro-tomography (mu-CT) for assessment of material mechanical toughness variation. An important part of this analysis is to recognize fibrillar features. This paper presents algorithms for detecting and quantifying composite cracks and fiber breaks from high-resolution image stacks. First, we propose recognition algorithms to identify the different structures of the composite, including matrix cracks and fibers breaks. Second, we introduce our package F3D for fast filtering of large 3D imagery, implemented in OpenCL to take advantage of graphic cards. Results show that our algorithms automatically identify micro-damage and that the GPU-based implementation introduced here takes minutes, being 17x faster than similar tools on a typical image file. C1 [Ushizima, Daniela; Perciano, Talita; Krishnan, Harinarayan; Loring, Burlen; Sethian, James] Lawrence Berkeley Natl Lab, Computat Res Div, Berkeley, CA 94720 USA. [Bale, Hrishikesh] Lawrence Berkeley Natl Lab, Mat Sci Div, Berkeley, CA USA. [Parkinson, Dilworth] Lawrence Berkeley Natl Lab, Adv Light Source Div, Berkeley, CA USA. [Ushizima, Daniela] Univ Calif Berkeley, Berkeley Inst Data Sci, Berkeley, CA 94720 USA. RP Ushizima, D (reprint author), Lawrence Berkeley Natl Lab, Computat Res Div, Berkeley, CA 94720 USA. EM dushizima@lbl.gov; tperciano@lbl.gov; hkrishnan@lbl.gov; bloring@lbl.gov; habale@lbl.gov; dyparkinson@lbl.gov; jasethian@lbl.gov RI Perciano, Talita/I-5977-2012 OI Perciano, Talita/0000-0002-2388-1803 NR 20 TC 2 Z9 2 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5666-1 PY 2014 BP 683 EP 691 PG 9 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2FK UT WOS:000380462900090 ER PT J AU Williams, DN Palanisamy, G Shipman, G Boden, TA Voyles, JW AF Williams, Dean N. Palanisamy, Giri Shipman, Galen Boden, Thomas A. Voyles, Jimmy W. GP IEEE BE Lin, J Hu, XH Chang, W Nambiar, R Aggarwal, C Cercone, N Honavar, V Huan, J Mobasher, B Pyne, S TI Department of Energy Strategic Roadmap for Earth System Science Data Integration SO 2014 IEEE INTERNATIONAL CONFERENCE ON BIG DATA (BIG DATA) LA English DT Proceedings Paper CT IEEE International Conference on Big Data CY OCT 27-30, 2014 CL Washington, DC SP IEEE, IEEE Comp Soc, ELSEVIER, Natl Sci Fdn, CISCO, CCF AB The U.S. Department of Energy (DOE) Office of Biological and Environmental Research (BER) Climate and Environmental Sciences Division (CESD) produces a diversity of data, information, software, and model codes across its research and informatics programs and facilities. This information includes raw and reduced observational and instrumentation data, model codes, model-generated results, and integrated data products. Currently, most of these data and information are prepared and shared for program specific activities, corresponding to CESD organization research. A major challenge facing BER CESD is how best to inventory, integrate, and deliver these vast and diverse resources for the purpose of accelerating Earth system science research. This paper provides a concept for a CESD Integrated Data Ecosystem and an initial roadmap for its implementation to address this integration challenge in the "Big Data" domain. C1 [Williams, Dean N.] Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA. [Palanisamy, Giri; Shipman, Galen; Boden, Thomas A.] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. [Voyles, Jimmy W.] Pacific Northwest Natl Lab, Richland, WA 99354 USA. RP Williams, DN (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA. NR 6 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5666-1 PY 2014 BP 772 EP 777 PG 6 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2FK UT WOS:000380462900102 ER PT J AU Devarakonda, R Shrestha, B Palanisamy, G Hook, L Killeffer, T Krassovski, M Boden, T Cook, R Zolly, L Hutchison, V Frame, M Cialella, A Lazer, K AF Devarakonda, Ranjeet Shrestha, Biva Palanisamy, Giriprakash Hook, Les Killeffer, Terri Krassovski, Misha Boden, Tom Cook, Robert Zolly, Lisa Hutchison, Viv Frame, Mike Cialella, Alice Lazer, Kathy GP IEEE BE Lin, J Hu, XH Chang, W Nambiar, R Aggarwal, C Cercone, N Honavar, V Huan, J Mobasher, B Pyne, S TI OME: Tool for generating and managing metadata to handle BigData SO 2014 IEEE INTERNATIONAL CONFERENCE ON BIG DATA (BIG DATA) LA English DT Proceedings Paper CT IEEE International Conference on Big Data CY OCT 27-30, 2014 CL Washington, DC SP IEEE, IEEE Comp Soc, ELSEVIER, Natl Sci Fdn, CISCO, CCF DE Online Metadata Editor (OME); FGDC CSDGM; Mercury Metadata System AB The next-generation On-line Metadata Editor (OME) is an easy-to-use tool to help document scientific data in a well-structured popular metadata format. In this paper, we discuss the newest tool that Oak Ridge National Laboratory has developed to input, edit, and manage metadata and how it is helping data intensive science centers across many federal agencies to prepare metadata and to make their BigData discoverable. C1 [Devarakonda, Ranjeet; Shrestha, Biva; Palanisamy, Giriprakash; Hook, Les; Killeffer, Terri; Krassovski, Misha; Boden, Tom; Cook, Robert] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. [Zolly, Lisa; Hutchison, Viv; Frame, Mike] US Geol Survey, Reston, VA 22092 USA. [Cialella, Alice; Lazer, Kathy] Brookhaven Natl Lab, Upton, NY 11973 USA. RP Devarakonda, R (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 2 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5666-1 PY 2014 PG 3 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2FK UT WOS:000380462900273 ER PT J AU Goodman, EL Jimenez, E al-Saffar, S Joslyn, C Haglin, D Grunwald, D AF Goodman, Eric L. Jimenez, Edward al-Saffar, Sinan Joslyn, Cliff Haglin, David Grunwald, Dirk GP IEEE BE Lin, J Hu, XH Chang, W Nambiar, R Aggarwal, C Cercone, N Honavar, V Huan, J Mobasher, B Pyne, S TI Optimizing Graph Queries with Graph Joins and Sprinkle SPARQL SO 2014 IEEE INTERNATIONAL CONFERENCE ON BIG DATA (BIG DATA) LA English DT Proceedings Paper CT IEEE International Conference on Big Data CY OCT 27-30, 2014 CL Washington, DC SP IEEE, IEEE Comp Soc, ELSEVIER, Natl Sci Fdn, CISCO, CCF AB Big data problems are often more akin to sparse graphs rather than relational tables. As such we argue that graph-based physical representations provide advantages in terms of both size and speed for executing queries. Drawing from research in sparse matrices, we use a compressed sparse row (CSR) format to model graph-oriented data. We also present two novel mechanisms for exploiting the CSR format that both find optimal join strategies and also prune variable bindings before expensive join operations occur. The first tactic we call Sprinkle SPARQL, which takes triple patterns of SPARQL queries and performs low-cost, linear-time set intersections to produce a constrained list of variable bindings for each variable in a query. Besides constrained lists of variable bindings, Sprinkle SPARQL also produces metrics that are consumed by the join algorithm to select an optimal execution path. The second tactic, graph joins, utilizes the CSR data structure as an index to efficiently join two variables expressed in a triple pattern together. We evaluate our approach on two data sets with over a billion edges: LUBM(8000) and an R-MAT graph generated with Graph500(1) parameters and extended to have edge labels. C1 [Goodman, Eric L.; Jimenez, Edward] Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. [al-Saffar, Sinan] Semant Scale LLC, Tampa, FL USA. [Joslyn, Cliff; Haglin, David] Pacific Northwest Natl Lab, Richland, WA USA. [Grunwald, Dirk] Univ Colorado, Boulder, CO 80309 USA. RP Goodman, EL (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. 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 978-1-4799-5666-1 PY 2014 PG 8 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2FK UT WOS:000380462900260 ER PT J AU Shrestha, B Devarakonda, R Palanisamy, G AF Shrestha, Biva Devarakonda, Ranjeet Palanisamy, Giriprakash GP IEEE BE Lin, J Hu, XH Chang, W Nambiar, R Aggarwal, C Cercone, N Honavar, V Huan, J Mobasher, B Pyne, S TI An open source framework to add spatial extent and geospatial visibility to Big Data SO 2014 IEEE INTERNATIONAL CONFERENCE ON BIG DATA (BIG DATA) LA English DT Proceedings Paper CT IEEE International Conference on Big Data CY OCT 27-30, 2014 CL Washington, DC SP IEEE, IEEE Comp Soc, ELSEVIER, Natl Sci Fdn, CISCO, CCF DE Big data; Geospatial search; Biodiversity data; BISON; GBIF AB Advancement in the field of computing and remote handheld devices has made the process of collecting geospatial data easy. Most of the time researchers and scientists have easy access to these data as well. However, the process of extracting and processing a large volume of data from several sources can be very time consuming and difficult. In most cases scientists rely on expensive proprietary software [1]. This paper discusses how Computational Scientists at Oak Ridge National Laboratory are extracting, normalizing, and processing millions of geospatial data points from multiple data sources and integrating them into a common data format which helps user to find and access these data using a flexible visualization-based user interface. C1 [Shrestha, Biva; Devarakonda, Ranjeet; Palanisamy, Giriprakash] Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RP Shrestha, B (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. EM shresthab@ornl.gov; devarakondar@ornl.gov; palanisamyg@ornl.gov NR 1 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5666-1 PY 2014 PG 3 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2FK UT WOS:000380462900292 ER PT J AU Tang, W Bischof, J Desai, N Mahadik, K Gerlach, W Harrison, T Wilke, A Meyer, F AF Tang, Wei Bischof, Jared Desai, Narayan Mahadik, Kanak Gerlach, Wolfgang Harrison, Travis Wilke, Andreas Meyer, Folker GP IEEE BE Lin, J Hu, XH Chang, W Nambiar, R Aggarwal, C Cercone, N Honavar, V Huan, J Mobasher, B Pyne, S TI Workload Characterization for MG-RAST Metagenomic Data Analytics Service in the Cloud SO 2014 IEEE INTERNATIONAL CONFERENCE ON BIG DATA (BIG DATA) LA English DT Proceedings Paper CT IEEE International Conference on Big Data CY OCT 27-30, 2014 CL Washington, DC SP IEEE, IEEE Comp Soc, ELSEVIER, Natl Sci Fdn, CISCO, CCF DE Big data applications; bioinformatics; workload characterization; data analytics as a service; cloud computing ID SEQUENCES; ALIGNMENT; SERVER; BLAST AB The cost of DNA sequencing has plummeted in recent years. The consequent data deluge has imposed big burdens for data analysis applications. For example, MG-RAST, a production open-public metagenome annotation service, has experienced increasingly large amount of data submission and has demanded scalable resources for the computational needs. To address this problem, we have developed a scalable platform to port MG-RAST workloads into the cloud, where elastic computing resources can be used on demand. To efficiently utilize such resources, however, one must understand the characteristics of the application workloads. In this paper, we characterize the MG-RAST workloads running in the cloud, from the perspectives of computation, I/O, and data transfer. Insights from this work will help guide application enhancement, service operation, and resource management for MG-RAST and similar big data applications demanding elastic computing resources. C1 [Tang, Wei; Bischof, Jared; Desai, Narayan; Gerlach, Wolfgang; Harrison, Travis; Wilke, Andreas; Meyer, Folker] Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. [Bischof, Jared; Gerlach, Wolfgang; Harrison, Travis; Wilke, Andreas; Meyer, Folker] Univ Chicago, Chicago, IL 60637 USA. [Desai, Narayan] Ericsson, San Jose, CA USA. [Mahadik, Kanak] Purdue Univ, W Lafayette, IN 47907 USA. RP Tang, W (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM wtang@mcs.anl.gov; jbischof@mcs.anl.gov; narayan.desai@ericsson.com; kmahadik@purdue.edu; wgerlach@mcs.anl.gov; teharrison@mcs.anl.gov; wilke@mcs.anl.gov; folker@mcs.anl.gov NR 21 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5666-1 PY 2014 PG 8 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2FK UT WOS:000380462900191 ER PT J AU Yu, YG Zou, HB Tang, W Liu, LW AF Yu, Yongen Zou, Hongbo Tang, Wei Liu, Liwei GP IEEE BE Lin, J Hu, XH Chang, W Nambiar, R Aggarwal, C Cercone, N Honavar, V Huan, J Mobasher, B Pyne, S TI A CCG Virtual System for Big Data Application Communication Costs Analysis SO 2014 IEEE INTERNATIONAL CONFERENCE ON BIG DATA (BIG DATA) LA English DT Proceedings Paper CT IEEE International Conference on Big Data CY OCT 27-30, 2014 CL Washington, DC SP IEEE, IEEE Comp Soc, ELSEVIER, Natl Sci Fdn, CISCO, CCF DE CCG Virtual System; virtualization; SDN; network topology; routing AB Network topology and routing are two important factors in determining the communication costs of big data applications at large scale. As for a given Cluster, Cloud, or Grid system, the network topology is fixed and static or dynamic routing protocols are preinstalled to direct the network traffic. Users cannot change them once the system is deployed. Hence, it is hard for application developers to identify the optimal network topology and routing algorithm for their applications with distinct communication patterns. In this study, we design a CCG virtual system (CCGVS), which first uses container-based virtualization to allow users to create a farm of lightweight virtual machines on a single host. Then, it uses software-defined networking (SDN) technique to control the network traffic among these virtual machines. Users can change the network topology and control the network traffic programmingly, thereby enabling application developers to evaluate their applications on the same system with different network topologies and routing algorithms. The preliminary experimental results through both synthetic big data programs and NPB benchmarks have shown that CCGVS can represent application performance variations caused by network topology and routing algorithm. C1 [Yu, Yongen] IIT, Dept Comp Sci, Chicago, IL 60616 USA. [Zou, Hongbo] Queensland Univ Technol, Brisbane, Qld 4001, Australia. [Tang, Wei] Argonne Natl Lab, Argonne, IL 60439 USA. [Liu, Liwei] Northwestern Univ, Evanston, IL USA. RP Yu, YG (reprint author), IIT, Dept Comp Sci, Chicago, IL 60616 USA. EM yyu22@iit.edu; hongbo.zou@student.qut.edu.au; wtang@mcs.anl.gov; liweiliu2011@u.northwestern.edu NR 29 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-5666-1 PY 2014 PG 7 WC Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BF2FK UT WOS:000380462900210 ER PT S AU Han, SC Qin, H Yu, DT AF Han, Shuchu Qin, Hong Yu, Dantong GP IEEE TI An Improved Ratio-based (IRB) Batch Effects Removal Algorithm for Cancer Data in a Co-analysis Framework SO 2014 IEEE INTERNATIONAL CONFERENCE ON BIOINFORMATICS AND BIOENGINEERING (BIBE) SE International Conference on Bioinformatics and Bioengineering LA English DT Proceedings Paper CT 14th IEEE International Conference on BioInformatics and BioEngineering (BIBE) CY NOV 10-12, 2014 CL Boca Raton, FL SP IEEE, IEEE Comp Soc, Biol and Artificial Intelligence Soc, Florida Atlantic Univ, ABI Fdn, Modernizing Med, LexisNexis ID GENE-EXPRESSION DATA; PREDICTION; NORMALIZATION; DISCOVERY AB Ratio-based algorithms are proven to be effective methods for removing batch effects that exist among microarray expression data from different data sources. They are outperforming than other methods in the enhancement of cross-batch prediction, especially for cancer data sets. However, their overall power is limited by: (1) Not every batch has control samples. The original method uses all negative samples to calculate the subtrahend. (2) Microarray experimental data may not have clear labels, especially in the prediction application, the labels of test data set are unknown. In this paper, we propose an Improved Ratio-Based (IRB) method to relieve these two constraints for cross-batch prediction applications. For each batch in a single study, we select one reference sample based on the idea of aligning probability density functions (pdfs) of each gene in different batches. Moreover, for data sets without label information, we transfer the problem of finding reference sample to the dense subgraph problem in graph theory. Our newly-proposed IRB method is straightforward and efficient, and can be extended for integrating large volume microarray data sets. The experiments show that our method is stable and has high performance in tumor/non-tumor prediction. C1 [Han, Shuchu; Qin, Hong] SUNY Stony Brook, Dept Comp Sci, Stony Brook, NY 11794 USA. [Yu, Dantong] Brookhaven Natl Lab, Computat Sci Ctr, Upton, NY 11973 USA. RP Han, SC (reprint author), SUNY Stony Brook, Dept Comp Sci, Stony Brook, NY 11794 USA. EM shhan@cs.stonybrook.edu; qin@cs.stonybrook.edu; dtyu@bnl.gov NR 29 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2471-7819 BN 978-1-4799-7502-0 J9 INT CONF BIOINFO BIO PY 2014 BP 212 EP 219 DI 10.1109/BIBE.2014.47 PG 8 WC Engineering, Biomedical SC Engineering GA BF2EI UT WOS:000380460200032 ER PT S AU Strnadova, V Buluc, A Chapman, J Gilbert, JR Gonzalez, J Jegelka, S Rokhsar, D Oliker, L AF Strnadova, Veronika Buluc, Aydin Chapman, Jarrod Gilbert, John R. Gonzalez, Joseph Jegelka, Stefanie Rokhsar, Daniel Oliker, Leonid BE Zheng, H Hu, X Berrar, D Wang, Y Dubitzky, W Hao, JK Cho, KH Gilbert, D TI Efficient and Accurate Clustering for Large-Scale Genetic Mapping SO 2014 IEEE INTERNATIONAL CONFERENCE ON BIOINFORMATICS AND BIOMEDICINE (BIBM) SE IEEE International Conference on Bioinformatics and Biomedicine-BIBM LA English DT Proceedings Paper CT IEEE International Conference on Bioinformatics and Biomedicine (IEEE BIBM) CY NOV 02-05, 2014 CL Univ Ulster, Belfast, NORTH IRELAND SP IEEE, Natl Sci Fdn, Nsilico, Comp Sci Res Inst, BioBusiness, IEEE Comp Soc, Engn Res Inst, Biomed Sci Res Inst HO Univ Ulster ID SOFTWARE; DISTANCES; VALUES AB High-throughput "next generation" genome sequencing technologies are producing a flood of inexpensive genetic information that is invaluable to genomics research. Sequences of millions of genetic markers are being produced, providing genomics researchers with the opportunity to construct high-resolution genetic maps for many complicated genomes. However, the current generation of genetic mapping tools were designed for the small data setting, and are now limited by the prohibitively slow clustering algorithms they employ in the genetic marker-clustering stage. In this work, we present a new approach to genetic mapping based on a fast clustering algorithm that exploits the geometry of the data. Our theoretical and empirical analysis shows that the algorithm can correctly recover linkage groups. Using synthetic and real-world data, including the grand-challenge wheat genome, we demonstrate that our approach can quickly process orders of magnitude more genetic markers than existing tools while retaining - and in some cases even improving - the quality of genetic marker clusters. C1 [Strnadova, Veronika; Buluc, Aydin; Oliker, Leonid] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Computat Res Div, Berkeley, CA 94720 USA. [Chapman, Jarrod; Rokhsar, Daniel] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Joint Genome Inst, Berkeley, CA 94720 USA. [Gonzalez, Joseph; Jegelka, Stefanie] Univ Calif Berkeley, Dept EECS, Berkeley, CA 94720 USA. [Rokhsar, Daniel] Univ Calif Berkeley, Mol & Cell Biol, Berkeley, CA 94720 USA. [Strnadova, Veronika; Gilbert, John R.] Univ Calif Santa Barbara, Dept Comp Sci, Santa Barbara, CA 93106 USA. RP Strnadova, V (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Computat Res Div, Berkeley, CA 94720 USA. NR 26 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2156-1125 BN 978-1-4799-5669-2 J9 IEEE INT C BIOINFORM PY 2014 PG 8 WC Computer Science, Interdisciplinary Applications; Mathematical & Computational Biology SC Computer Science; Mathematical & Computational Biology GA BE9FO UT WOS:000377412300093 ER PT S AU Carroll, TE Crouse, M Fulp, EW Berenhaut, KS AF Carroll, Thomas E. Crouse, Michael Fulp, Errin W. Berenhaut, Kenneth S. BE Jamalipour, A Deng, DJ TI Analysis of Network Address Shuffling as a Moving Target Defense SO 2014 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS (ICC) SE IEEE International Conference on Communications LA English DT Proceedings Paper CT IEEE International Conference on Communications (ICC) CY JUN 10-14, 2014 CL Sydney, AUSTRALIA SP IEEE AB Address shuffling is a type of moving target defense that prevents an attacker from reliably contacting a system by periodically remapping network addresses. Although limited testing has demonstrated it to be effective, little research has been conducted to examine the theoretical limits of address shuffling. As a result, it is difficult to understand how effective shuffling is and under what circumstances it is a viable moving target defense. This paper introduces probabilistic models that can provide insight into the performance of address shuffling. These models quantify the probability of attacker success in terms of network size, quantity of addresses scanned, quantity of vulnerable systems, and the frequency of shuffling. Theoretical analysis shows that shuffling is an acceptable defense if there is a small population of vulnerable systems within a large network address space, however shuffling has a cost for legitimate users. These results will also be shown empirically using simulation and actual traffic traces. C1 [Carroll, Thomas E.] Pacific NW Natl Lab, Richland, WA 99352 USA. [Crouse, Michael] Harvard Univ, Dept Comp Sci, Cambridge, MA 02138 USA. [Fulp, Errin W.; Berenhaut, Kenneth S.] Wake Forest Univ, Dept Comp Sci, Winston Salem, NC 27109 USA. [Fulp, Errin W.; Berenhaut, Kenneth S.] Wake Forest Univ, Dept Math, Winston Salem, NC 27109 USA. RP Carroll, TE (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. EM Thomas.Carroll@pnl.gov; mcrouse@seas.harvard.edu; fulp@wfu.edu; berenhks@wfu.edu NR 10 TC 10 Z9 10 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1550-3607 BN 978-1-4799-2003-7 J9 IEEE ICC PY 2014 BP 701 EP 706 PG 6 WC Telecommunications SC Telecommunications GA BE0RF UT WOS:000366666800117 ER PT S AU Wasden, DL Moradi, H Farhang-Boroujeny, B AF Wasden, Daryl Leon Moradi, Hussein Farhang-Boroujeny, Behrouz BE Jamalipour, A Deng, DJ TI Comparison of Direct Sequence Spread Spectrum Rake Receiver with a Maximum Ratio Combining Multicarrier Spread Spectrum Receiver SO 2014 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS (ICC) SE IEEE International Conference on Communications LA English DT Proceedings Paper CT IEEE International Conference on Communications (ICC) CY JUN 10-14, 2014 CL Sydney, AUSTRALIA SP IEEE ID DS-CDMA SYSTEMS; MULTIPATH-FADING CHANNEL; PERFORMANCE; INTERFERENCE AB This paper presents a theoretical analysis of the performance of a filter bank-based multicarrier spread spectrum (FB-MC-SS) system. In FB-MC-SS, each data symbol is spread across multiple subcarriers, but-contrary to some other systems-there is no spreading in time. The results of this system are then compared with those of the well-known direct sequence spread spectrum (DS-SS) system with a rake receiver for its best performance. We compare the two systems when the channel noise is white. We prove that as the processing gains of the two systems tend to infinity both systems approach the same performance. However, numerical simulations show that in practice, where processing gain is limited, FB-MC-SS outperforms DS-SS. C1 [Wasden, Daryl Leon; Farhang-Boroujeny, Behrouz] Univ Utah, Dept Elect & Comp Engn, Salt Lake City, UT 84112 USA. [Moradi, Hussein] Idaho Natl Lab, Idaho Falls, ID 83415 USA. RP Wasden, DL (reprint author), Univ Utah, Dept Elect & Comp Engn, Salt Lake City, UT 84112 USA. EM wasden@ece.utah.edu; hussein.moradi@inl.gov; farhang@ece.utah.edu NR 25 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1550-3607 BN 978-1-4799-2003-7 J9 IEEE ICC PY 2014 BP 4656 EP 4661 PG 6 WC Telecommunications SC Telecommunications GA BE0RF UT WOS:000366666804137 ER PT S AU Huang, H Yoo, S Yu, DT Qin, H AF Huang, Hao Yoo, Shinjae Yu, Dantong Qin, Hong BE Kumar, R Toivonen, H Pei, J Huang, JZ Wu, X TI Diverse Power Iteration Embeddings and Its Applications SO 2014 IEEE International Conference on Data Mining (ICDM) SE IEEE International Conference on Data Mining LA English DT Proceedings Paper CT 14th IEEE International Conference on Data Mining (IEEE ICDM) CY DEC 14-17, 2014 CL Shenzhen, PEOPLES R CHINA SP Baidu, HUAWEI, PINGAN, IBM Res, KNIME, Alberta Innovates Ctr Machine Learning, IEEE, IEEE Comp Soc AB Spectral Embedding is one of the most effective dimension reduction algorithms in data mining. However, its computation complexity has to be mitigated in order to apply it for real-world large scale data analysis. Many researches have been focusing on developing approximate spectral embeddings which are more efficient, but meanwhile far less effective. This paper proposes Diverse Power Iteration Embeddings (DPIE), which not only retains the similar efficiency of power iteration methods but also produces a series of diverse and more effective embedding vectors. We test this novel method by applying it to various data mining applications (e.g. clustering, anomaly detection and feature selection) and evaluating their performance improvements. The experimental results show our proposed DPIE is more effective than popular spectral approximation methods, and obtains the similar quality of classic spectral embedding derived from eigen-decompositions. Moreover it is extremely fast on big data applications. For example in terms of clustering result, DPIE achieves as good as 95% of classic spectral clustering on the complex datasets but 4000+ times faster in limited memory environment. C1 [Huang, Hao; Qin, Hong] SUNY Stony Brook, Dept Comp Sci, Stony Brook, NY 11794 USA. [Yoo, Shinjae; Yu, Dantong] Brookhaven Natl Lab, Computat Sci Ctr, Upton, NY 11973 USA. RP Huang, H (reprint author), SUNY Stony Brook, Dept Comp Sci, Stony Brook, NY 11794 USA. EM haohuangcssbu@gmail.com; sjyoo@bnl.gov; dtyu@bnl.gov; qin@cs.stonybrook.edu NR 28 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1550-4786 BN 978-1-4799-4303-6 J9 IEEE DATA MINING PY 2014 BP 200 EP 209 DI 10.1109/ICDM.2014.87 PG 10 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems SC Computer Science GA BG4YF UT WOS:000389267400021 ER PT S AU Huang, H Yoo, S Yu, DT Qin, H AF Huang, Hao Yoo, Shinjae Yu, Dantong Qin, Hong BE Kumar, R Toivonen, H Pei, J Huang, JZ Wu, X TI Noise-Resistant Unsupervised Feature Selection via Multi-Perspective Correlations SO 2014 IEEE International Conference on Data Mining (ICDM) SE IEEE International Conference on Data Mining LA English DT Proceedings Paper CT 14th IEEE International Conference on Data Mining (IEEE ICDM) CY DEC 14-17, 2014 CL Shenzhen, PEOPLES R CHINA SP Baidu, HUAWEI, PINGAN, IBM Res, KNIME, Alberta Innovates Ctr Machine Learning, IEEE, IEEE Comp Soc AB Unsupervised feature selection is an important issue for high dimensional dataset analysis. However popular methods are susceptible to noisy instances (observations) or noisy features. We propose a noise-resistant feature selection algorithm by capturing multi-perspective correlations. Our proposed approach, called Noise-Resistant Unsupervised Feature Selection (NRFS), is based on multi-perspective correlation that reflects the importance of feature with respect to noise-resistant representative instances and various global trends from spectral decomposition. In this way, the model concisely captures a wide variety of local patterns. Experimental results demonstrate the effectiveness of our algorithm. C1 [Huang, Hao; Qin, Hong] SUNY Stony Brook, Dept Comp Sci, Stony Brook, NY 11794 USA. [Yoo, Shinjae; Yu, Dantong] Brookhaven Natl Lab, Computat Sci Ctr, Upton, NY 11973 USA. RP Huang, H (reprint author), SUNY Stony Brook, Dept Comp Sci, Stony Brook, NY 11794 USA. EM haohuangcssbu@gmail.com; sjyoo@bnl.gov; dtyu@bnl.gov; qin@cs.stonybrook.edu NR 44 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1550-4786 BN 978-1-4799-4303-6 J9 IEEE DATA MINING PY 2014 BP 210 EP 219 DI 10.1109/ICDM.2014.88 PG 10 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems SC Computer Science GA BG4YF UT WOS:000389267400022 ER PT S AU Shah, N Beutel, A Gallagher, B Faloutsos, C AF Shah, Neil Beutel, Alex Gallagher, Brian Faloutsos, Christos BE Kumar, R Toivonen, H Pei, J Huang, JZ Wu, X TI Spotting Suspicious Link Behavior with fBox: An Adversarial Perspective SO 2014 IEEE International Conference on Data Mining (ICDM) SE IEEE International Conference on Data Mining LA English DT Proceedings Paper CT 14th IEEE International Conference on Data Mining (IEEE ICDM) CY DEC 14-17, 2014 CL Shenzhen, PEOPLES R CHINA SP Baidu, HUAWEI, PINGAN, IBM Res, KNIME, Alberta Innovates Ctr Machine Learning, IEEE, IEEE Comp Soc AB How can we detect suspicious users in large online networks? Online popularity of a user or product (via follows, page-likes, etc.) can be monetized on the premise of higher ad click-through rates or increased sales. Web services and social networks which incentivize popularity thus suffer from a major problem of fake connections from link fraudsters looking to make a quick buck. Typical methods of catching this suspicious behavior use spectral techniques to spot large groups of often blatantly fraudulent (but sometimes honest) users. However, small-scale, stealthy attacks may go unnoticed due to the nature of low-rank eigenanalysis used in practice. In this work, we take an adversarial approach to find and prove claims about the weaknesses of modern, state-of-the-art spectral methods and propose FBOX, an algorithm designed to catch small-scale, stealth attacks that slip below the radar. Our algorithm has the following desirable properties: (a) it has theoretical underpinnings, (b) it is shown to be highly effective on real data and (c) it is scalable (linear on the input size). We evaluate FBOX on a large, public 41.7 million node, 1.5 billion edge who-follows-whom social graph from Twitter in 2010 and with high precision identify many suspicious accounts which have persisted without suspension even to this day. C1 [Shah, Neil; Beutel, Alex; Faloutsos, Christos] Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. [Gallagher, Brian] Lawrence Livermore Lab, Livermore, CA USA. RP Shah, N (reprint author), Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. EM neilshah@cs.cmu.edu; abeutel@cs.cmu.edu; bgallagher@llnl.gov; christos@cs.cmu.edu NR 15 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1550-4786 BN 978-1-4799-4303-6 J9 IEEE DATA MINING PY 2014 BP 959 EP 964 DI 10.1109/ICDM.2014.36 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems SC Computer Science GA BG4YF UT WOS:000389267400113 ER PT S AU Tao, CX Ge, Y Song, QB Ge, Y Omitaomu, OA AF Tao, Changxia Ge, Yong Song, Qinbao Ge, Yuan Omitaomu, Olufemi A. BE Kumar, R Toivonen, H Pei, J Huang, JZ Wu, X TI Metric Ranking of Invariant Networks with Belief Propagation SO 2014 IEEE International Conference on Data Mining (ICDM) SE IEEE International Conference on Data Mining LA English DT Proceedings Paper CT 14th IEEE International Conference on Data Mining (IEEE ICDM) CY DEC 14-17, 2014 CL Shenzhen, PEOPLES R CHINA SP Baidu, HUAWEI, PINGAN, IBM Res, KNIME, Alberta Innovates Ctr Machine Learning, IEEE, IEEE Comp Soc DE Invariant; ARX Model; Invariant Networks; Belief Propogation ID SYSTEMS AB The management of large-scale distributed information systems relies on the effective use and modeling of monitoring data collected at various points in the distributed information systems. A promising approach is to discover invariant relationships among the monitoring data and generate invariant networks, where a node is a monitoring data source (metric) and a link indicates an invariant relationship between two monitoring data. Such an invariant network representation can help system experts to localize and diagnose the system faults by examining those broken invariant relationships and their related metrics, because system faults usually propagate among the monitoring data and eventually lead to some broken invariant relationships. However, at one time, there are usually a lot of broken links (invariant relationships) within an invariant network. Without proper guidance, it is difficult for system experts to manually inspect this large number of broken links. Thus, a critical challenge is how to effectively and efficiently rank metrics (nodes) of invariant networks according to the anomaly levels of metrics. The ranked list of metrics will provide system experts with useful guidance for them to localize and diagnose the system faults. To this end, we propose to model the nodes and the broken links as a Markov Random Field (MRF), and develop an iteration algorithm to infer the anomaly of each node based on belief propagation (BP). Finally, we validate the proposed algorithm on both real-world and synthetic data sets to illustrate its effectiveness. C1 [Tao, Changxia; Song, Qinbao] Xi An Jiao Tong Univ, Xian, Peoples R China. [Ge, Yong] Univ North Carolina Charlotte, Charlotte, NC USA. [Omitaomu, Olufemi A.] Oak Ridge Natl Lab, Oak Ridge, TN USA. [Ge, Yuan] Anhui Polytech Univ, Wuhu, Anhui, Peoples R China. RP Ge, Y (reprint author), Anhui Polytech Univ, Wuhu, Anhui, Peoples R China. EM taoxixi413@stu.xjtu.edu.cn; yong.ge@uncc.edu; qbsong@mail.xjtu.edu.cn; ygetoby@mail.ustc.edu.cn; omitaomuoa@ornl.gov NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1550-4786 BN 978-1-4799-4303-6 J9 IEEE DATA MINING PY 2014 BP 1001 EP 1006 DI 10.1109/ICDM.2014.74 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems SC Computer Science GA BG4YF UT WOS:000389267400120 ER PT J AU Dong, TX Haidar, A Luszczek, P Harris, JA Tomov, S Dongarra, J AF Dong, Tingxing Haidar, Azzam Luszczek, Piotr Harris, James Austin Tomov, Stanimire Dongarra, Jack GP IEEE TI LU Factorization of Small Matrices: Accelerating Batched DGETRF on the GPU SO 2014 IEEE INTERNATIONAL CONFERENCE ON HIGH PERFORMANCE COMPUTING AND COMMUNICATIONS, 2014 IEEE 6TH INTL SYMP ON CYBERSPACE SAFETY AND SECURITY, 2014 IEEE 11TH INTL CONF ON EMBEDDED SOFTWARE AND SYST (HPCC,CSS,ICESS) LA English DT Proceedings Paper CT 16th IEEE International Conference on High Performance Computing and Communications HPCC 2014\11th IEEE International Conference on Embedded Software and Systems ICESS 2014\6th International Symposium on Cyberspace Safety and Security CSS 2014 CY AUG 20-22, 2014 CL Paris, FRANCE SP FEMTO-ST Inst, Ecole Cent Paris, Ecole Mines Paris, IEEE, IEEE Computer Society, IEEE Tech Comm Scalable Comp AB Gaussian Elimination is commonly used to solve dense linear systems in scientific models. In a large number of applications, a need arises to solve many small size problems, instead of few large linear systems. The size of each of these small linear systems depends on the number of the ordinary differential equations (ODEs) used in the model, and can be on the order of hundreds of unknowns. To efficiently exploit the computing power of modern accelerator hardware, these linear systems are processed in batches. To improve the numerical stability, at least partial pivoting is required, most often accomplished with row pivoting. However, row pivoting can result in a severe performance penalty on GPUs because it brings in thread divergence and non-coalesced memory accesses. In this paper, we propose a batched LU factorization for GPUs by using a multi-level blocked right looking algorithm that preserves the data layout but minimizes the penalty of partial pivoting. Our batched LU achieves up to 2.5-fold speedup when compared to the alternative CUBLAS solution on a K40c GPU. C1 [Dong, Tingxing; Haidar, Azzam; Luszczek, Piotr; Harris, James Austin; Tomov, Stanimire; Dongarra, Jack] Univ Tennessee, Knoxville, TN 37996 USA. [Dongarra, Jack] Oak Ridge Natl Lab, Oak Ridge, TN USA. [Dongarra, Jack] Univ Manchester, Manchester M13 9PL, Lancs, England. RP Dong, TX (reprint author), Univ Tennessee, Knoxville, TN 37996 USA. EM tdong@utk.edu; haidar@utk.edu; luszczek@utk.edu; tomov@utk.edu; dongarra@utk.edu OI Harris, J. Austin/0000-0003-3023-7140 NR 5 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS BN 978-1-4799-6123-8 PY 2014 BP 157 EP 160 DI 10.1109/HPCC.2014.30 PG 4 WC Computer Science, Information Systems; Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BF3NX UT WOS:000380560600024 ER PT S AU Rodriguez, P Wohlberg, B AF Rodriguez, Paul Wohlberg, Brendt GP IEEE TI PERFORMANCE COMPARISON OF ITERATIVE REWEIGHTING METHODS FOR TOTAL VARIATION REGULARIZATION SO 2014 IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING (ICIP) SE IEEE International Conference on Image Processing ICIP LA English DT Proceedings Paper CT IEEE International Conference on Image Processing (ICIP) CY OCT 27-30, 2014 CL Paris, FRANCE SP IEEE DE Total Variation; Iteratively Reweighted Least Squares; Iteratively Reweighted Norm ID NOISE REMOVAL; MINIMIZATION; ALGORITHMS; OUTLIERS AB Iteratively Reweighted Least Squares (IRLS) is a well-established method of optimizing l(p) norm problems such as Total Variation (TV) regularization. Within this general framework, there are several possible ways of constructing the weights and the form of the linear system that is iteratively solved as part of the algorithm. Many of these choices are equally reasonable from a theoretical perspective, and there has, thus far, been no systematic comparison between them. In this paper we provide such a comparison between the main choices in IRLS algorithms for l(1)- and l(2)-TV denoising, finding that there is a significant variation in the computational cost and reconstruction quality of the different variants. C1 [Rodriguez, Paul] Pontificia Univ Catolica Peru, Dept Elect, Lima, Peru. [Wohlberg, Brendt] Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Rodriguez, P (reprint author), Pontificia Univ Catolica Peru, Dept Elect, Lima, Peru. OI Wohlberg, Brendt/0000-0002-4767-1843 NR 22 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1522-4880 BN 978-1-4799-5751-4 J9 IEEE IMAGE PROC PY 2014 BP 1758 EP 1762 PG 5 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Imaging Science & Photographic Technology SC Computer Science; Engineering; Imaging Science & Photographic Technology GA BE2TU UT WOS:000370063601187 ER PT S AU Wohlberg, B AF Wohlberg, Brendt GP IEEE TI ENDOGENOUS CONVOLUTIONAL SPARSE REPRESENTATIONS FOR TRANSLATION INVARIANT IMAGE SUBSPACE MODELS SO 2014 IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING (ICIP) SE IEEE International Conference on Image Processing ICIP LA English DT Proceedings Paper CT IEEE International Conference on Image Processing (ICIP) CY OCT 27-30, 2014 CL Paris, FRANCE SP IEEE DE Subspace Models; Translation Invariance; Convolutional Sparse Representation ID FACE RECOGNITION AB Subspace models for image data sets, constructed by computing sparse representations of each image with respect to other images in the set, have been found to perform very well in a variety of applications, including clustering and classification problems. One of the limitations of these methods, however, is that the subspace representation is unable to directly model the effects of non-linear transformations such as translation, rotation, and dilation that frequently occur in practice. In this paper it is shown that the properties of convolutional sparse representations can be exploited to make these methods translation invariant, thereby simplifying or eliminating the alignment pre-processing task. The potential of the proposed approach is demonstrated in two diverse applications: image clustering and video background modeling. C1 [Wohlberg, Brendt] Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RP Wohlberg, B (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. OI Wohlberg, Brendt/0000-0002-4767-1843 NR 18 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1522-4880 BN 978-1-4799-5751-4 J9 IEEE IMAGE PROC PY 2014 BP 2859 EP 2863 PG 5 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Imaging Science & Photographic Technology SC Computer Science; Engineering; Imaging Science & Photographic Technology GA BE2TU UT WOS:000370063603006 ER PT S AU Thiagarajan, JJ Ramamurthy, KN Sattigeri, P Bremer, PT Spanias, A AF Thiagarajan, J. J. Ramamurthy, K. N. Sattigeri, P. Bremer, P. T. Spanias, A. GP IEEE TI AUTOMATIC IMAGE ANNOTATION USING INVERSE MAPS FROM SEMANTIC EMBEDDINGS SO 2014 IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING (ICIP) SE IEEE International Conference on Image Processing ICIP LA English DT Proceedings Paper CT IEEE International Conference on Image Processing (ICIP) CY OCT 27-30, 2014 CL Paris, FRANCE SP IEEE DE Image annotation; sparse coding; embedding; inverse map; RBF interpolation ID RETRIEVAL AB Human annotation in large scale image databases is time-consuming and error-prone. Since it is very hard to mine image databases using just visual features or textual descriptors, it is common to transform the image features into a semantically meaningful space. In this paper, we propose to perform image annotation in a semantic space inferred based on sparse representations. By constructing a semantic embedding for the visual features, that is constrained to be close to the tag embedding, we show that a robust inverse map can be used to predict the tags. Experiments using standard datasets show the effectiveness of the proposed approach in automatic image annotation when compared to existing methods. C1 [Thiagarajan, J. J.; Bremer, P. T.] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. [Ramamurthy, K. N.] IBM Thomas J Watson Res Ctr, Yorktown Hts, NY USA. [Sattigeri, P.; Spanias, A.] Arizona State Univ, Sch ECEE, SenSIP Ctr, Tempe, AZ 85287 USA. RP Thiagarajan, JJ (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 19 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1522-4880 BN 978-1-4799-5751-4 J9 IEEE IMAGE PROC PY 2014 BP 3107 EP 3111 PG 5 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Imaging Science & Photographic Technology SC Computer Science; Engineering; Imaging Science & Photographic Technology GA BE2TU UT WOS:000370063603056 ER PT S AU Kim, H Thiagarajan, JJ Bremer, PT AF Kim, Hyojin Thiagarajan, Jayaraman J. Bremer, Peer-Timo GP IEEE TI IMAGE SEGMENTATION USING CONSENSUS FROM HIERARCHICAL SEGMENTATION ENSEMBLES SO 2014 IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING (ICIP) SE IEEE International Conference on Image Processing ICIP LA English DT Proceedings Paper CT IEEE International Conference on Image Processing (ICIP) CY OCT 27-30, 2014 CL Paris, FRANCE SP IEEE DE Unsupervised segmentation; multiple hierarchies; consensus clustering; graph cuts; superpixels ID CUTS AB Unsupervised, automatic image segmentation without contextual knowledge, or user intervention is a challenging problem. The key to robust segmentation is an appropriate selection of local features and metrics. However, a single aggregation of the local features using a greedy merging order often results in incorrect segmentation. This paper presents an unsupervised approach, which uses the consensus inferred from hierarchical segmentation ensembles, for partitioning images into foreground and background regions. By exploring an expanded set of possible aggregations of the local features, the proposed method generates meaningful segmentations that are not often revealed when only the optimal hierarchy is considered. A graph cuts-based approach is employed to combine the consensus along with a foreground-background model estimate, obtained using the ensemble, for effective segmentation. Experiments with a standard dataset show promising results when compared to several existing methods including the state-of-the-art weak supervised techniques that use co-segmentation. C1 [Kim, Hyojin; Thiagarajan, Jayaraman J.; Bremer, Peer-Timo] Lawrence Livermore Natl Lab, Livermore, CA USA. RP Kim, H (reprint author), Lawrence Livermore Natl Lab, Livermore, CA USA. NR 17 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1522-4880 BN 978-1-4799-5751-4 J9 IEEE IMAGE PROC PY 2014 BP 3272 EP 3276 PG 5 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Imaging Science & Photographic Technology SC Computer Science; Engineering; Imaging Science & Photographic Technology GA BE2TU UT WOS:000370063603090 ER PT S AU Rodriguez, P Wohlberg, B AF Rodriguez, Paul Wohlberg, Brendt GP IEEE TI A MATLAB IMPLEMENTATION OF A FAST INCREMENTAL PRINCIPAL COMPONENT PURSUIT ALGORITHM FOR VIDEO BACKGROUND MODELING SO 2014 IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING (ICIP) SE IEEE International Conference on Image Processing ICIP LA English DT Proceedings Paper CT IEEE International Conference on Image Processing (ICIP) CY OCT 27-30, 2014 CL Paris, FRANCE SP IEEE DE Principal Component Pursuit; Video Background Modeling; incremental SVD AB In this proposal we present a Matlab-only implementation of a simple, novel, and fully incremental Principal Component Pursuit (PCP) algorithm for Video Background Modeling. Our implementation can process full HD color 1920 x 1088 videos at a rate of 0.61 seconds per frame running on a standard laptop (Intel i7-2670QM quad-core, 6GB RAM, 2.2 GHz). Unlike other incremental or online PCP-like algorithms, such as ReProCS, GRASTA or pROST, the initialization stage of our implementation is extremely fast, has modest memory requirements (6.5 seconds and less than 0.5 Gb for a full HD video), and is also able to quickly adapt to changes in the background. Moreover our implementation can also process live-feed videos, which in our proposed demonstration will be acquired via a wireless camera, resulting in an interactive demonstration where the the moving objects to be segmented are the audience. C1 [Rodriguez, Paul] Pontificia Univ Catolica Peru, Dept Elect Engn, Lima, Peru. [Wohlberg, Brendt] Los Alamos Natl Lab, Appl Math & Plasma Phys T5, Los Alamos, NM 87545 USA. RP Rodriguez, P (reprint author), Pontificia Univ Catolica Peru, Dept Elect Engn, Lima, Peru. OI Wohlberg, Brendt/0000-0002-4767-1843 NR 14 TC 5 Z9 6 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1522-4880 BN 978-1-4799-5751-4 J9 IEEE IMAGE PROC PY 2014 BP 3414 EP 3416 PG 3 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Imaging Science & Photographic Technology SC Computer Science; Engineering; Imaging Science & Photographic Technology GA BE2TU UT WOS:000370063603120 ER PT S AU Lind, J Rollett, AD Pokharel, R Hefferan, C Li, SF Lienert, U Suter, R AF Lind, Jonathan Rollett, Anthony D. Pokharel, Reeju Hefferan, Christopher Li, Shiu-Fai Lienert, Ulrich Suter, Robert GP IEEE TI IMAGE PROCESSING IN EXPERIMENTS ON, AND SIMULATIONS OF PLASTIC DEFORMATION OF POLYCRYSTALS SO 2014 IEEE INTERNATIONAL CONFERENCE ON IMAGE PROCESSING (ICIP) SE IEEE International Conference on Image Processing ICIP LA English DT Proceedings Paper CT IEEE International Conference on Image Processing (ICIP) CY OCT 27-30, 2014 CL Paris, FRANCE SP IEEE DE X-ray Diffraction (XRD); High Energy Diffraction Microscopy (HEDM); Fast Fourier Transform (FFT); Orientation Gradients; Texture; Simulation; Edge Detection ID RAY-DIFFRACTION MICROSCOPY; 3 DIMENSIONS; MICROSTRUCTURE; COPPER AB Comparisons between experiments and simulations of deformation of polycrystalline materials reveal some interesting challenges [1]. Addressing first the image processing issues, electron back-scatter diffraction (EBSD) [2] relies heavily on image transformations of electron diffraction patterns. High energy diffraction microscopy (HEDM) [3] also relies on thresholding of the diffractograms for peak identification [4]. By contrast to the standard finite element method, an image-based approach [5] that relies on the Fast Fourier Transform (FFT) has started to be used for simulating plastic deformation because it offers a more efficient solution of the same equations (e.g. mechanical equilibrium). It is possible, for example, to import directly a measured 3D image from HEDM into the FFT simulation code and simulate with no need for the time-consuming step of creating a 3D mesh. Common filters applied to orientation maps in particular, include grain average strain, Kernel Average Misorientation (KAM), Grain Orientation Spread (GOS), Intragranular Grain Misorientation (IGM). C1 [Rollett, Anthony D.] Carnegie Mellon Univ, Mat Sci & Engn, Pittsburgh, PA 15213 USA. [Lind, Jonathan; Li, Shiu-Fai] Los Alamos Natl Lab, Los Alamos, NM USA. [Pokharel, Reeju] Lawrence Livermore Natl Lab, Livermore, CA USA. [Hefferan, Christopher] RJ Lee Inc, Pittsburgh, PA USA. [Lienert, Ulrich] DESY, Hamburg, Germany. [Suter, Robert] Carnegie Mellon Univ, Phys, Pittsburgh, PA 15213 USA. RP Lind, J (reprint author), Los Alamos Natl Lab, Los Alamos, NM USA. EM rollett@cmu.edu RI Suter, Robert/P-2541-2014 OI Suter, Robert/0000-0002-0651-0437 NR 17 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1522-4880 BN 978-1-4799-5751-4 J9 IEEE IMAGE PROC PY 2014 BP 4877 EP 4881 PG 5 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Imaging Science & Photographic Technology SC Computer Science; Engineering; Imaging Science & Photographic Technology GA BE2TU UT WOS:000370063605009 ER PT S AU Vlachopoulou, M Chin, G Fuller, J Lu, S AF Vlachopoulou, Maria Chin, George Fuller, Jason Lu, Shuai GP IEEE TI Aggregated Residential Load Modeling Using Dynamic Bayesian Networks SO 2014 IEEE INTERNATIONAL CONFERENCE ON SMART GRID COMMUNICATIONS (SMARTGRIDCOMM) SE International Conference on Smart Grid Communications LA English DT Proceedings Paper CT 2014 IEEE International Conference on Smart Grid Communications (SmartGridComm) CY NOV 03-06, 2014 CL Venice, ITALY DE Aggregated load; Bayesian networks; demand response; load modeling AB It is already obvious that the future power grid will have to address higher demand for power and energy, and to incorporate renewable resources of different energy generation patterns. Demand response (DR) schemes could successfully be used to manage and balance power supply and demand under operating conditions of the future power grid. To achieve that, more advanced tools for DR management of operations and planning are necessary that can estimate the available capacity from DR resources. In this research, a Dynamic Bayesian Network (DBN) is derived, trained, and tested that can model aggregated load of Heating, Ventilation, and Air Conditioning (HVAC) systems. DBNs can provide flexible and powerful tools for both operations and planning, due to their unique analytical capabilities. The DBN model accuracy and flexibility of use is demonstrated by testing the model under different operational scenarios. C1 [Vlachopoulou, Maria; Chin, George; Fuller, Jason; Lu, Shuai] PNNL, Richland, WA 99354 USA. RP Vlachopoulou, M (reprint author), PNNL, Richland, WA 99354 USA. EM maria.vlachop@gmail.com 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 SN 2373-6836 BN 978-1-4799-4934-2 J9 INT CONF SMART GRID PY 2014 BP 818 EP 823 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BF2FI UT WOS:000380462700137 ER PT S AU Koutsandria, G Muthukumar, V Parvania, M Peisert, S McParland, C Scaglione, A AF Koutsandria, Georgia Muthukumar, Vishak Parvania, Masood Peisert, Sean McParland, Chuck Scaglione, Anna GP IEEE TI A Hybrid Network IDS for Protective Digital Relays in the Power Transmission Grid SO 2014 IEEE INTERNATIONAL CONFERENCE ON SMART GRID COMMUNICATIONS (SMARTGRIDCOMM) SE International Conference on Smart Grid Communications LA English DT Proceedings Paper CT 2014 IEEE International Conference on Smart Grid Communications (SmartGridComm) CY NOV 03-06, 2014 CL Venice, ITALY AB In this paper, we propose a novel use of network intrusion detection systems (NIDSs) tailored to detect attacks against networks that support hybrid controllers that implement power grid protection schemes. In our approach, we implement specification-based intrusion detection signatures based on the execution of the hybrid automata that specify the communication rules and physical limits that the system should obey. To validate our idea, we developed an experimental framework consisting of a simulation of the physical system and an emulation of the master controller, which serves as the digital relay that implements the protection mechanism. Our Hybrid Control NIDS (HC-NIDS) continuously monitors and analyzes the network traffic exchanged within the physical system. It identifies traffic that deviates from the expected communication pattern or physical limitations, which could place the system in an unsafe mode of operation. Our experimental analysis demonstrates that our approach is able to detect a diverse range of attack scenarios aimed at compromising the physical process by leveraging information about the physical part of the power system. C1 [Koutsandria, Georgia; Parvania, Masood; Scaglione, Anna] Univ Calif Davis, Dept Elect & Comp Engn, Davis, CA 95616 USA. [Muthukumar, Vishak; Peisert, Sean] Univ Calif Davis, Dept Comp Sci, Davis, CA 95616 USA. [Peisert, Sean; McParland, Chuck] Lawrence Berkeley Natl Lab, Berkeley, CA USA. RP Koutsandria, G (reprint author), Univ Calif Davis, Dept Elect & Comp Engn, Davis, CA 95616 USA. NR 16 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2373-6836 BN 978-1-4799-4934-2 J9 INT CONF SMART GRID PY 2014 BP 908 EP 913 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA BF2FI UT WOS:000380462700152 ER PT S AU Zhang, DL Hendry, G Dechev, D AF Zhang, Deli Hendry, Gilbert Dechev, Damian GP IEEE TI Tools for Enabling Automatic Validation of Large-scale Parallel Application Simulations SO 2014 IEEE INTERNATIONAL CONFERENCE ON SOFTWARE MAINTENANCE AND EVOLUTION (ICSME) SE Proceedings-IEEE International Conference on Software Maintenance LA English DT Proceedings Paper CT 30th IEEE International Conference on Software Maintenance and Evolution (ICSME) CY SEP 28-OCT 03, 2014 CL Victoria, CANADA SP IEEE Comp Soc, Techn Council Software Engn, Microsoft Res, Dell Res, SAP, IBM Canada Lab, Grammatech, SD, Universidad ICESI, Univ Alberta, Univ Victoria, Conf publishing serv, CAS ResTechnol Incubat Lab ID PERFORMANCE AB Validation is highly important in parallel application simulations with a large number of parameters, a process that can vary depending on the structure of the simulator and the granularity of the models used. Common practice involves calculating the percentage error between the projected and the real execution time of a benchmark program. However, this coarse-grained approach often suffers from a parameter insensitivity problem in regions of high-dimensional parameter space. In this work we demonstrate the use of our fine-grained validation toolset to capture and compare the statistical characteristics of a parallel application's execution. It is the first toolset to apply fine-grained statistics to large-scale simulation validation, and our experimental evaluation shows that it offers a significant improvement in fidelity when compared to validation using total execution time. C1 [Zhang, Deli; Dechev, Damian] Univ Cent Florida, Orlando, FL 32816 USA. [Hendry, Gilbert; Dechev, Damian] Sandia Natl Labs, Livermore, CA USA. RP Zhang, DL (reprint author), Univ Cent Florida, Orlando, FL 32816 USA. EM de-li.zhang@knights.ucf.edu; ghendry@sandia.gov; dechev@eecs.ucf.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 SN 1063-6773 BN 978-0-7695-5303-0 J9 PROC IEEE INT CONF S PY 2014 BP 601 EP 604 DI 10.1109/ICSME.2014.105 PG 4 WC Computer Science, Software Engineering SC Computer Science GA BF2QY UT WOS:000380491700084 ER PT S AU Estepp, JR Blackford, EB Meier, CM AF Estepp, Justin R. Blackford, Ethan B. Meier, Christopher M. GP IEEE TI Recovering Pulse Rate During Motion Artifact with a Multi-Imager Array for Non-Contact Imaging Photoplethysmography SO 2014 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN AND CYBERNETICS (SMC) SE IEEE International Conference on Systems Man and Cybernetics Conference Proceedings LA English DT Proceedings Paper CT IEEE International Conference on Systems, Man, and Cybernetics (SMC) CY OCT 05-08, 2014 CL San Diego, CA SP IEEE DE imaging photoplethysmography; pulse rate; blind source separation; independent component analysis; electrocardiography ID INDEPENDENT COMPONENT ANALYSIS; AMBIENT LIGHT; TECHNOLOGY; ALGORITHM AB Photoplethysmography relies on characteristic changes in the optical absorption of tissue due to pulsatile (arterial) blood flow in peripheral vasculature. Sensors for observing the photoplethysmographic effect have traditionally required contact with the skin surface. Recent advances in non-contact imaging photoplethysmography have demonstrated that measures of cardiopulmonary system state, such as pulse rate, pulse rate variability, and respiration rate, can be obtained from a participant by imaging their face under relatively motionless conditions. A critical limitation in this method that must be resolved is the inability to recover these measures under conditions of head motion artifact. To investigate the adequacy of channel space dimensionality for the use of blind source separation in this context, nine synchronized, visible spectrum imagers positioned in a semicircular array centered on the imaged participant were used for data acquisition in a controlled lighting environment. Three-lead electrocardiogram and fingertip reflectance photoplethysmogram were also recorded as ground truth signals. Controlled head motion artifact trial conditions were compared to trials in which the participant remained stationary, with and without the aid of a chinrest. Bootstrapped means of one-minute, non-overlapping trial segments show that, for situations involving little to no head motion, a single imager is sufficient for recovering pulse rate with an average absolute error of less than two beats per minute. However, error in the recovered pulse rate measurement for the single imager can be as high as twenty-two beats per minute when head motion artifact is severe. This increase in measurement error during motion artifact was mitigated by increasing the dimensionality of the imager channel space with multiple imagers in the array prior to applying blind source separation. In contrast to single-imager results, the multi-imager channel space resulted in an absolute error in the recovered pulse rate measurement that is comparable with pulse rate measured via fingertip reflectance photoplethysmography. These results demonstrate that non-contact, imaging photoplethysmography can be accurate in the presence of head motion artifact when a multi-imager array is implemented to increase the dimensionality of the decomposed channel space. C1 [Estepp, Justin R.] Air Force Res Lab, Human Performance Wing 711, Wright Patterson AFB, OH USA. [Blackford, Ethan B.] Ball Aerosp & Technol Corp, Wright Patterson AFB, OH USA. [Meier, Christopher M.] Oak Ridge Inst Sci & Educ, Wright Patterson AFB, OH USA. RP Estepp, JR (reprint author), Air Force Res Lab, Human Performance Wing 711, Wright Patterson AFB, OH USA. EM justin.estepp@us.af.mil; ethan.blackford.ctr@us.af.mil; christopher.meier.5.ctr@us.af.mil NR 30 TC 4 Z9 4 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1062-922X BN 978-1-4799-3840-7 J9 IEEE SYS MAN CYBERN PY 2014 BP 1462 EP 1469 PG 8 WC Computer Science, Artificial Intelligence; Computer Science, Cybernetics; Computer Science, Information Systems SC Computer Science GA BE3MJ UT WOS:000370963701098 ER PT J AU Duran, A Ragatz, A Prohaska, R Kelly, K Walkowicz, K AF Duran, Adam Ragatz, Adam Prohaska, Robert Kelly, Kenneth Walkowicz, Kevin GP IEEE TI Characterization of In-Use Medium Duty Electric Vehicle Driving and Charging Behavior SO 2014 IEEE INTERNATIONAL ELECTRIC VEHICLE CONFERENCE (IEVC) LA English DT Proceedings Paper CT 2014 IEEE International Electric Vehicle Conference (IEVC) CY DEC 17-19, 2014 CL Florence, ITALY DE Medium Duty (MD); Electric Vehicle (EV); Charging Behavior; Driving Behavior; Smith; Navistar; Commercial Vehicle AB The U.S. Department of Energy's American Recovery and Reinvestment Act (ARRA) deployment and demonstration projects are helping to commercialize technologies for all-electric vehicles (EVs). Under the ARRA program, data from Smith Electric and Navistar medium duty EVs have been collected, compiled, and analyzed in an effort to quantify the impacts of these new technologies. Over a period of three years, the National Renewable Energy Laboratory (NREL) has compiled data from over 250 Smith Newton EVs for a total of over 100,000 days of in-use operation. Similarly, data have been collected from over 100 Navistar eStar vehicles, with over 15,000 operating days having been analyzed. NREL has analyzed a combined total of over 4 million kilometers of driving and 1 million hours of charging data for commercial operating medium duty EVs. In this paper, the authors present an overview of medium duty EV operating and charging behavior based on in-use data collected from both Smith and Navistar vehicles operating in the United States. Specifically, this paper provides an introduction to the specifications and configurations of the vehicles examined; discusses the approach and methodology of data collection and analysis, and presents detailed results regarding daily driving and charging behavior. In addition, trends observed over the course of multiple years of data collection are examined, and conclusions are drawn about early deployment behavior and ongoing adjustments due to new and improving technology. Results and metrics such as average daily driving distance, route aggressiveness, charging frequency, and liter per kilometer diesel equivalent fuel consumption are documented and discussed. C1 [Duran, Adam; Ragatz, Adam; Prohaska, Robert; Kelly, Kenneth; Walkowicz, Kevin] Natl Renewable Energy Lab, Transportat & Hydrogen Syst Ctr, Golden, CO 80401 USA. RP Duran, A (reprint author), Natl Renewable Energy Lab, Transportat & Hydrogen Syst Ctr, Golden, CO 80401 USA. EM Adam.Duran@nrel.gov; Adam.Ragatz@nrel.gov; Robert.Prohaska@nrel.gov; Kenneth.Kelly@nrel.gov; Kevin.Walkowicz@nrel.gov NR 16 TC 0 Z9 0 U1 2 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-6075-0 PY 2014 PG 8 WC Engineering, Electrical & Electronic; Transportation Science & Technology SC Engineering; Transportation GA BF1GJ UT WOS:000380394300139 ER PT J AU Jones, PT Onar, O AF Jones, P. T. Onar, Omer GP IEEE TI Impact of Wireless Power Transfer in Transportation: Future Transportation Enabler, or Near Term Distraction SO 2014 IEEE INTERNATIONAL ELECTRIC VEHICLE CONFERENCE (IEVC) LA English DT Proceedings Paper CT 2014 IEEE International Electric Vehicle Conference (IEVC) CY DEC 17-19, 2014 CL Florence, ITALY DE wireless power transfer; inductive charging; opportunity charging; dynamic wireless charging; electric vehicles AB While the total liquid fuels consumed in the U.S. for transportation of goods and people is expected to hold steady, or decline slightly over the next few decades, the world wide consumption is projected to increase of over 30% according to the Annual Energy Outlook 2014 [1]. The balance of energy consumption for transportation between petroleum fuels and electric energy, and the related greenhouse gas (GHG) emissions produced consuming either, is of particular interest to government administrations, vehicle OEMs, and energy suppliers. The market adoption of plug-in electric vehicles (PEVs) appears to be inhibited by many factors relating to the energy storage system (ESS) and charging infrastructure. Wireless power transfer (WPT) technologies have been identified as a key enabling technology to increase the acceptance of EVs. Oak Ridge National Laboratory (ORNL) has been involved in many research areas related to understanding the impacts, opportunities, challenges and costs related to various deployments of WPT technology for transportation use. Though the initial outlook for WPT deployment looks promising, many other emerging technologies have met unfavorable market launches due to unforeseen technology limitations, sometimes due to the complex system in which the new technology was placed. This paper will summarize research and development (R&D) performed at ORNL in the area of Wireless Power Transfer (WPT). ORNL's advanced transportation technology R&D activities provide a unique set of experienced researchers to assist in the creation of a transportation system level view. These activities range from fundamental technology development at the component level to subsystem controls and interactions to applicable system level analysis of impending market and industry responses and beyond. C1 [Jones, P. T.] Oak Ridge Natl Lab, Vehicle Syst Res, Knoxville, TN 37932 USA. [Onar, Omer] Oak Ridge Natl Lab, Power Elect & Elect Machines, Knoxville, TN 37932 USA. RP Jones, PT (reprint author), Oak Ridge Natl Lab, Vehicle Syst Res, Knoxville, TN 37932 USA. EM ptj@ornl.gov; onaroc@ornl.gov 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 978-1-4799-6075-0 PY 2014 PG 7 WC Engineering, Electrical & Electronic; Transportation Science & Technology SC Engineering; Transportation GA BF1GJ UT WOS:000380394300129 ER PT J AU Li, JM Jones, PT Onar, O Starke, M AF Li, Jan-Mou Jones, Perry T. Onar, Omer Starke, Michael GP IEEE TI Coupling Electric Vehicles and Power Grid through Charging-In-Motion and Connected Vehicle Technology SO 2014 IEEE INTERNATIONAL ELECTRIC VEHICLE CONFERENCE (IEVC) LA English DT Proceedings Paper CT 2014 IEEE International Electric Vehicle Conference (IEVC) CY DEC 17-19, 2014 CL Florence, ITALY DE network coupling; supernetwork; electric vehicle (EV); smart grid; charging in-motion; connected vehicle ID TRANSPORTATION NETWORKS; ALGORITHM; MOBILITY; PROFILE; IMPACT AB A traffic-assignment-based framework is proposed to model the coupling of transportation network and power grid for analyzing impacts of energy demand from electric vehicles on the operation of power distribution. Although the reverse can be investigated with the proposed framework as well, electricity flowing from a power grid to electric vehicles is the focus of this paper. Major variables in transportation network (including link flows) and power grid (including electricity transmitted) are introduced for the coupling. Roles of charging-in-motion technology and connected vehicle technology have been identified in the framework of supernetwork. A linkage (i.e. individual energy demand) between the two networks is defined to construct the supernetwork. To determine equilibrium of the supernetwork can also answer how many drivers are going to use the charging-in-motion services, in which locations, and at what time frame. An optimal operation plan of power distribution will be decided along the determination simultaneously by which we have a picture about what level of power demand from the grid is expected in locations during an analyzed period. Caveat of the framework and possible applications have also been discussed. C1 [Li, Jan-Mou; Jones, Perry T.] Oak Ridge Natl Lab, Energy & Transportat Sci Div, Knoxville, TN 37831 USA. [Onar, Omer; Starke, Michael] Oak Ridge Natl Lab, Elect & Elect Syst Res Div, Knoxville, TN USA. RP Li, JM (reprint author), Oak Ridge Natl Lab, Energy & Transportat Sci Div, Knoxville, TN 37831 USA. EM lij3@ornl.gov; jonespt@ornl.gov; onaroc@ornl.gov; starkemr@ornl.gov NR 26 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-6075-0 PY 2014 PG 7 WC Engineering, Electrical & Electronic; Transportation Science & Technology SC Engineering; Transportation GA BF1GJ UT WOS:000380394300144 ER PT J AU Pourazarm, S Cassandras, CG Malikopoulos, A AF Pourazarm, Sepideh Cassandras, Christos G. Malikopoulos, Andreas GP IEEE TI Optimal Routing of Electric Vehicles in Networks with Charging Nodes: A Dynamic Programming Approach SO 2014 IEEE INTERNATIONAL ELECTRIC VEHICLE CONFERENCE (IEVC) LA English DT Proceedings Paper CT 2014 IEEE International Electric Vehicle Conference (IEVC) CY DEC 17-19, 2014 CL Florence, ITALY DE Electric Vehicles; Routing; Optimal Recharging Policy; Optimal Control; Dynamic Programming AB Motivated by the significant role of recharging in battery-powered vehicles, we study the routing problem for vehicles with limited energy through a network of charging nodes. We seek to minimize the total elapsed time for vehicles to reach their destinations considering both traveling and recharging times at nodes when the vehicles do not have adequate energy for the entire journey. We have studied the case of homogeneous charging nodes in [1] and generalized it to inhomogeneous charging nodes in [2] by formulating and solving a Mixed Integer Non-Linear Programming problem (MINLP) for a single-vehicle. In this paper, we solve the same problem using Dynamic Programming (DP), resulting in optimal solutions with lower computational complexity compared to [2]. For a multi-vehicle problem, where traffic congestion effects are included, we use a similar approach by grouping vehicles into "subflows" and propose a DP formulation. Our numerical results show that DP becomes prohibitively slow as the number of subflows increases. As in [1] and [2] we resort to an alternative flow optimization formulation leading to a computationally simpler problem solution with minimal loss of accuracy. C1 [Pourazarm, Sepideh; Cassandras, Christos G.] Boston Univ, Div Syst Engn, Boston, MA 02215 USA. [Malikopoulos, Andreas] Oak Ridge Natl Lab, Urban Dynam Inst, Oak Ridge, TN 37831 USA. RP Pourazarm, S (reprint author), Boston Univ, Div Syst Engn, Boston, MA 02215 USA. EM sepid@bu.edu; cgc@bu.edu; andreas@ornl.gov 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 978-1-4799-6075-0 PY 2014 PG 7 WC Engineering, Electrical & Electronic; Transportation Science & Technology SC Engineering; Transportation GA BF1GJ UT WOS:000380394300036 ER PT J AU Shaltout, ML Chen, DM Malikopoulos, AA Pannala, S AF Shaltout, Mohamed L. Chen, Dongmei Malikopoulos, Andreas A. Pannala, Sreekanth GP IEEE TI Multi-Disciplinary Decision Making and Optimization for Hybrid Electric Propulsion Systems SO 2014 IEEE INTERNATIONAL ELECTRIC VEHICLE CONFERENCE (IEVC) LA English DT Proceedings Paper CT 2014 IEEE International Electric Vehicle Conference (IEVC) CY DEC 17-19, 2014 CL Florence, ITALY ID LITHIUM-ION BATTERY; POWER MANAGEMENT; SIMULATIONS; VEHICLES; CELLS AB In this paper, we investigate the trade-offs among the subsystems of a hybrid electric vehicle (HEV), e.g., the engine, motor, and the battery, and discuss the related implications for fuel consumption and battery capacity and lifetime. Addressing this problem can provide insights on how to prioritize these objectives based on consumers' needs and preferences. C1 [Shaltout, Mohamed L.; Chen, Dongmei] Univ Texas Austin, Dept Mech Engn, Austin, TX 78712 USA. [Malikopoulos, Andreas A.; Pannala, Sreekanth] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Shaltout, ML (reprint author), Univ Texas Austin, Dept Mech Engn, Austin, TX 78712 USA. EM andreas@ornl.gov NR 21 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-6075-0 PY 2014 PG 6 WC Engineering, Electrical & Electronic; Transportation Science & Technology SC Engineering; Transportation GA BF1GJ UT WOS:000380394300138 ER PT J AU Heidel, TD Gradzki, P AF Heidel, Timothy D. Gradzki, Pawel GP IEEE TI Power Devices on Bulk Gallium Nitride Substrates: An Overview of ARPA-E's SWITCHES Program SO 2014 IEEE INTERNATIONAL ELECTRON DEVICES MEETING (IEDM) SE International Electron Devices Meeting LA English DT Proceedings Paper CT 60th Annual IEEE International Electron Devices Meeting (IEDM) CY DEC 15-17, 2014 CL San Francisco, CA SP IEEE, IEEE Electron Devices Soc AB Wide bandgap power semiconductor devices offer substantial energy efficiency opportunities in a wide range of applications. However, to date, relatively high cost has impeded the widespread adoption of these devices in many high volume applications. Recent progress in high quality bulk GaN substrates offers a new potential pathway to the development of novel vertical power semiconductor devices in gallium nitride. If successfully developed, these devices could offer a pathway to functional cost parity with silicon-based power devices at higher power levels. The Advanced Research Projects Agency-Energy (ARPA-E)' s recently launched SWITCHES program is targeting the development of bulk GaN, 1200 V, 100 A transistors and diodes. In this paper, we give an overview of the technical approaches within the program and discuss some of the major anticipated challenges. C1 [Heidel, Timothy D.] US DOE, ARPA E, Washington, DC 20585 USA. [Gradzki, Pawel] Booz Allen Hamilton, Washington, DC USA. RP Heidel, TD (reprint author), US DOE, ARPA E, Washington, DC 20585 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 978-1-4799-8000-0 J9 INT EL DEVICES MEET PY 2014 PG 4 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BE3AI UT WOS:000370384800008 ER PT J AU Wang, DB Tian, H Martin-Fernandez, I Yang, Y Ren, TL Zhang, YG AF Wang, Debin Tian, He Martin-Fernandez, Inigo Yang, Yi Ren, Tian-Ling Zhang, Yuegang GP IEEE TI Large-Scale Fabrication of Graphene-based Electronic and MEMS Devices SO 2014 IEEE INTERNATIONAL ELECTRON DEVICES MEETING (IEDM) SE International Electron Devices Meeting LA English DT Proceedings Paper CT 60th Annual IEEE International Electron Devices Meeting (IEDM) CY DEC 15-17, 2014 CL San Francisco, CA SP IEEE, IEEE Electron Devices Soc ID DIRECT GROWTH C1 [Wang, Debin; Martin-Fernandez, Inigo; Zhang, Yuegang] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. [Tian, He; Yang, Yi; Ren, Tian-Ling; Zhang, Yuegang] Tsinghua Univ, Inst Microelect, Beijing 100084, Peoples R China. [Tian, He; Yang, Yi; Ren, Tian-Ling; Zhang, Yuegang] Tsinghua Univ, Tsinghua Natl Lab Informat Sci & Technol TNList, Beijing 100084, Peoples R China. [Zhang, Yuegang] Chinese Acad Sci, Suzhou Inst Nanotech & Nanobion, Suzhou 215123, Peoples R China. RP Ren, TL (reprint author), Tsinghua Univ, Inst Microelect, Beijing 100084, Peoples R China. EM RenTL@tsinghua.edu.cn; ygzhang2012@sinano.ac.cn RI Tian, He/I-1299-2014 OI Tian, He/0000-0001-7328-2182 NR 3 TC 0 Z9 0 U1 1 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-8000-0 J9 INT EL DEVICES MEET PY 2014 PG 4 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BE3AI UT WOS:000370384800094 ER PT S AU Shi, L Katramatos, D Yu, DT AF Shi, Li Katramatos, Dimitrios Yu, Dantong GP IEEE TI Virtual Data Center Allocation with Dynamic Clustering in Clouds SO 2014 IEEE INTERNATIONAL PERFORMANCE COMPUTING AND COMMUNICATIONS CONFERENCE (IPCCC) SE IEEE International Performance Computing and Communications Conference (IPCCC) LA English DT Proceedings Paper CT 33rd IEEE International Performance, Computing, and Communications Conference (IPCCC) CY DEC 05-07, 2014 CL Austin, TX SP IEEE, IEEE Comp Soc Tech Comm Simulat, IEEE Comp Soc Tech Comm Comp Commun, IEEE Central Texas Sect, IEEE Comp Soc AB Clouds are being widely used for leasing resources to users in the form of on-demand virtual data centers, which comprise sets of virtual machines interconnected by sets of virtual links. Given a user request for a virtual data center with specific resource requirements, a critical problem is to select a set of servers and links in the physical data center of a cloud to satisfy the request in a manner that minimizes the amount of reserved resources. In this paper, we study the main aspects of this Virtual Data Center Allocation (VDCA) problem, and decompose it into three subproblems: virtual data center clustering, virtual machine allocation, and virtual link allocation. We prove the NP-hardness of VDCA and propose an algorithm that solves the problem by dynamically clustering the requested virtual data center and jointly optimizing virtual machine and virtual link allocation. We further compare the performance and scalability of the proposed algorithm with two existing algorithms, called LoCo and SecondNet, through simulations. We demonstrate that our algorithm generates 30%-200% more revenue than LoCo and 55%-300% than SecondNet, while being up to 12 times faster. C1 [Shi, Li] SUNY Stony Brook, Dept Elect & Comp Engn, Stony Brook, NY 11794 USA. [Katramatos, Dimitrios; Yu, Dantong] Brookhaven Natl Lab, Computat Sci Ctr, Upton, NY 11973 USA. RP Shi, L (reprint author), SUNY Stony Brook, Dept Elect & Comp Engn, Stony Brook, NY 11794 USA. EM li.shi@stonybrook.edu; dkat@bnl.gov; dtyu@bnl.gov NR 17 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1097-2641 BN 978-1-4799-7575-4 J9 IEEE IPCCC PY 2014 PG 10 WC Computer Science, Theory & Methods; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA BE2QN UT WOS:000369860500084 ER PT S AU Waldron, WL Gonsalves, AJ Leemans, WP AF Waldron, William L. Gonsalves, Anthony J. Leemans, Wim P. BE Garner, AL TI A High Voltage Pulsed Power Supply to Drive a Capillary Discharge Waveguide at KHz Repetition Rates SO 2014 IEEE INTERNATIONAL POWER MODULATOR AND HIGH VOLTAGE CONFERENCE (IPMHVC) SE IEEE International Power Modulator and High Voltage Conference LA English DT Proceedings Paper CT IEEE International Power Modulator and High Voltage Conference (IPMHVC) CY JUN 01-05, 2014 CL Santa Fe, NM SP IEEE, IEEE Dielectr & Elect Insulat Soc, Dean Technol, Gen Atom, HVR, Matsusada Precis, ScandiNova, BEHLKE, TDK Lamda, Stangenes Ind Inc, Diversified Technol Inc, NWL, Ultra Elect, RFI, FILTRON, Stanley, Pearson Electronics, 5S, Continental Elect Corp, Dawonsys, Jema, GMWAssociates, SCHOTT, Barth Elect Inc, BiRa Syst, METEK, TREK, DYNAPOWER Co, e2v, Caton ID ELECTRON-ACCELERATORS; BEAMS AB In laser plasma accelerators (LPAs), electrons are accelerated by the electric field of a laser-driven plasma wave. A plasma channel such as that produced in a capillary discharge waveguide can extend the acceleration distance and increase the electron energy gain. This kind of waveguide utilizes a high voltage pulsed power supply to ionize the gas and heat the resulting plasma inside the waveguide. High repetition rate capillary discharge structures are being investigated to enable applications such as future light sources and high-energy colliders. This paper describes the design and initial results of a 1 kHz demonstration system. C1 [Waldron, William L.; Gonsalves, Anthony J.; Leemans, Wim P.] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Waldron, WL (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 10 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2380-808X BN 978-1-4799-4047-9; 978-1-4673-7323-4 J9 IEEE INT POWER MODUL PY 2014 BP 57 EP 59 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BE3FS UT WOS:000370659000014 ER PT S AU Laity, GR Barnat, EV AF Laity, George R. Barnat, Edward V. BE Garner, AL TI A Microwave Resonance Diagnostic for Measuring Characteristics of Pulsed Ion Beams SO 2014 IEEE INTERNATIONAL POWER MODULATOR AND HIGH VOLTAGE CONFERENCE (IPMHVC) SE IEEE International Power Modulator and High Voltage Conference LA English DT Proceedings Paper CT IEEE International Power Modulator and High Voltage Conference (IPMHVC) CY JUN 01-05, 2014 CL Santa Fe, NM SP IEEE, IEEE Dielectr & Elect Insulat Soc, Dean Technol, Gen Atom, HVR, Matsusada Precis, ScandiNova, BEHLKE, TDK Lamda, Stangenes Ind Inc, Diversified Technol Inc, NWL, Ultra Elect, RFI, FILTRON, Stanley, Pearson Electronics, 5S, Continental Elect Corp, Dawonsys, Jema, GMWAssociates, SCHOTT, Barth Elect Inc, BiRa Syst, METEK, TREK, DYNAPOWER Co, e2v, Caton DE Beam Physics; Vacuum Arcs; RF-Plasma Interaction; Accelerator Physics; Microwave Engineering ID DISTRIBUTIONS; ENERGY AB This paper describes an experiment to characterize ions generated by a pulsed vacuum arc by using a microwave resonant cavity (MRC) as a transient diagnostic. Specific information is desired on the various species which can drift into the beam during repetitive operations of arc plasma generation. The arc source reference voltage is elevated above ground (similar to 200V), which results in a separation of ion species in the beam due to the acceleration experienced by the ions. The cylindrical MRC used in this study has a resonant frequency of similar to 2.8 GHz when excited by a continuous RF source in the TM01 mode of operation. When the neutralized ion beam propagates through the MRC located downstream from the arc source, the resonant frequency of the MRC is shifted by the local disturbance in electric field inside the cavity due to the presence of the electron space charge in the beam. Coupled with the time-of-flight separation of various ion masses, the MRC resonance shift provides a temporally resolved measurement of beam species and density downstream from the vacuum ion source without the use of a potentially invasive diagnostic such as charge collector plates within the beam cross-section. This diagnostic technique should prove useful in a variety of pulsed ion beam studies and applications in research and industrial environments. C1 [Laity, George R.; Barnat, Edward V.] Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RP Laity, GR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 8 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2380-808X BN 978-1-4799-4047-9; 978-1-4673-7323-4 J9 IEEE INT POWER MODUL PY 2014 BP 60 EP 62 PG 3 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BE3FS UT WOS:000370659000015 ER PT S AU Reass, WA Audia, JM Baca, DM Balmes, AJ Earley, LM Haynes, WB Harrison, JS Key, D AF Reass, W. A. Audia, J. M. Baca, D. M. Balmes, A. J. Earley, L. M. Haynes, W. B. Harrison, J. S. Key, D. BE Garner, AL TI Final Klystron Modulator Design, Testing, and Installation Plan for the Los Alamos Neutron Science Center Accelerator SO 2014 IEEE INTERNATIONAL POWER MODULATOR AND HIGH VOLTAGE CONFERENCE (IPMHVC) SE IEEE International Power Modulator and High Voltage Conference LA English DT Proceedings Paper CT IEEE International Power Modulator and High Voltage Conference (IPMHVC) CY JUN 01-05, 2014 CL Santa Fe, NM SP IEEE, IEEE Dielectr & Elect Insulat Soc, Dean Technol, Gen Atom, HVR, Matsusada Precis, ScandiNova, BEHLKE, TDK Lamda, Stangenes Ind Inc, Diversified Technol Inc, NWL, Ultra Elect, RFI, FILTRON, Stanley, Pearson Electronics, 5S, Continental Elect Corp, Dawonsys, Jema, GMWAssociates, SCHOTT, Barth Elect Inc, BiRa Syst, METEK, TREK, DYNAPOWER Co, e2v, Caton DE Klystron; accelerator; triode; modulator AB This paper describes the production design, initial testing, and the installation plan of the 44 totem-pole pair, triode based klystron modulator systems that will be installed on the Los Alamos Neutron Science Center (LANSCE) accelerator RF system. The existing modulators were designed in the late 60's and replacement components are no longer available. That design uses a single triode tube as a saturated switch to develop the required klystron mod-anode voltage. This design dissipates almost 15 kW and requires oil pumps and oil/water heat exchangers to maintain safe oil tank temperatures. The new modulator switches electrostatically, charging and discharging the klystron mod-anode capacitance. Analog feedback control is utilized to ensure the klystron beam current is flat-top regulated. The new totem-pole design also provides faster rise and fall characteristics which reduces klystron collector dissipation. The new modulator is designed to operate the klystrons up to 86 kV with a nominal 32 Amp beam current at a 120 Hz repetition rate and a 15% duty cycle (>400 kW). The on and off deck modulators are of identical design and utilize a cascode connected planar triode, cathode driven with a high speed MOSFET. Voltage divider feedback is connected to the planar triode grid to enable flat-top control. Although modern design approaches suggest solid state designs may be considered, the planar triode (Eimac Y-847B) is very cost effective and has a low power (50 W) matrix cathode which is easy to integrate with the existing hardware. With the high mu gain characteristics, the triode provides a simplified linear feedback control mechanism. The design is very compact and fault tolerant. This paper will review the final design, test parameters, and the expected installation plan for the LANSCE accelerator. C1 [Reass, W. A.; Audia, J. M.; Baca, D. M.; Balmes, A. J.; Earley, L. M.; Haynes, W. B.; Harrison, J. S.; Key, D.] Los Alamos Natl Lab, Accelerator Operat & Technol, POB 1663, Los Alamos, NM 87545 USA. RP Reass, WA (reprint author), Los Alamos Natl Lab, Accelerator Operat & Technol, POB 1663, Los Alamos, NM 87545 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2380-808X BN 978-1-4799-4047-9; 978-1-4673-7323-4 J9 IEEE INT POWER MODUL PY 2014 BP 67 EP 72 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BE3FS UT WOS:000370659000017 ER PT S AU Leckbee, JJ Pena, GE Kiefer, ML Alexander, JA Stoltzfus, BS Brown, JL Wigelsworth, H White, FE Bui, B AF Leckbee, J. J. Pena, G. E. Kiefer, M. L. Alexander, J. A. Stoltzfus, B. S. Brown, J. L. Wigelsworth, H. White, F. E. Bui, B. BE Garner, AL TI Comparison of Trigger Requirements for Gas Switches for Linear Transformer Drivers SO 2014 IEEE INTERNATIONAL POWER MODULATOR AND HIGH VOLTAGE CONFERENCE (IPMHVC) SE IEEE International Power Modulator and High Voltage Conference LA English DT Proceedings Paper CT IEEE International Power Modulator and High Voltage Conference (IPMHVC) CY JUN 01-05, 2014 CL Santa Fe, NM SP IEEE, IEEE Dielectr & Elect Insulat Soc, Dean Technol, Gen Atom, HVR, Matsusada Precis, ScandiNova, BEHLKE, TDK Lamda, Stangenes Ind Inc, Diversified Technol Inc, NWL, Ultra Elect, RFI, FILTRON, Stanley, Pearson Electronics, 5S, Continental Elect Corp, Dawonsys, Jema, GMWAssociates, SCHOTT, Barth Elect Inc, BiRa Syst, METEK, TREK, DYNAPOWER Co, e2v, Caton AB Linear Transformer Driver (LTD) technology is being developed for short pulse electron beam applications as well as high current Z-pinch drivers. Designs for both applications require low inductance spark gap switches which hold off 200 kV and trigger with low jitter. LTD cells or cavities typically contain many parallel switches which must close with low jitter to insure efficient operation of the system. The switch jitter must be much less than the risetime of the output pulse to prevent switches from firing after the peak in output power. Experiments with a 10-brick Ursa Minor cavity indicate that the switch jitter must be less than 2 ns to limit the late switch rate to less than 2%. Three swith designs have been tested in a single switch platform to evaluate switch jitter as a function of the peak trigger voltage, trigger pulse risetime, and switch pressure. Operating parameters were determined for each switch to meet the 2 ns jitter requirement. C1 [Leckbee, J. J.; Pena, G. E.; Kiefer, M. L.; Alexander, J. A.; Stoltzfus, B. S.] Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. [Brown, J. L.; Wigelsworth, H.] Fiore Ind Inc, Albuquerque, NM USA. [White, F. E.; Bui, B.] Leidos, Albuquerque, NM USA. RP Leckbee, JJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 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 SN 2380-808X BN 978-1-4799-4047-9; 978-1-4673-7323-4 J9 IEEE INT POWER MODUL PY 2014 BP 93 EP 96 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BE3FS UT WOS:000370659000023 ER PT S AU James, GF McHale, GB Arnold, PA Runtal, AS Cardinale, PS Pades, LS AF James, G. F. McHale, G. B. Arnold, P. A. Runtal, A. S. Cardinale, P. S. Pades, L. S. BE Garner, AL TI NIF Solid-State Switch Pulse Generator Optimization for Multi-Pulse Operation SO 2014 IEEE INTERNATIONAL POWER MODULATOR AND HIGH VOLTAGE CONFERENCE (IPMHVC) SE IEEE International Power Modulator and High Voltage Conference LA English DT Proceedings Paper CT IEEE International Power Modulator and High Voltage Conference (IPMHVC) CY JUN 01-05, 2014 CL Santa Fe, NM SP IEEE, IEEE Dielectr & Elect Insulat Soc, Dean Technol, Gen Atom, HVR, Matsusada Precis, ScandiNova, BEHLKE, TDK Lamda, Stangenes Ind Inc, Diversified Technol Inc, NWL, Ultra Elect, RFI, FILTRON, Stanley, Pearson Electronics, 5S, Continental Elect Corp, Dawonsys, Jema, GMWAssociates, SCHOTT, Barth Elect Inc, BiRa Syst, METEK, TREK, DYNAPOWER Co, e2v, Caton AB A solid-state high voltage pulse generator developed as part of the Advanced Radiographic Capability (ARC) mission for the National Ignition Facility (NIF) has been deployed. This paper will provide details of the pulser design and the upgrades required to achieve reliable operation for multi-pulse bursts for an ever-increasing mission space. The pulser design has been demonstrated to be robust, reliable and to meet all performance specifications as they apply to the Plasma Electrode Pockels Cell (PEPC). This pulser is realized as a FET-driven twenty-seven stage magnetic adder operating with 700 volt primaries. It delivers a programmable multi-pulse burst of 18 kV, 3 kA pulses to a PEPC at repetition rates up to 1 Hertz. The typical pulse widths are 200ns with 20ns rise-and-fall-times at the pulser. A capacitive load, significant cable lengths between pulser and Pockels cell, fast transition times, and the microsecond type delays between pulses lead to non-ideal interactions that must be addressed to limit pulse distortion and reduce stress on the pulse electronics. In this paper we discuss the various options considered for resolving these issues, down-select decisions, and test results that demonstrate improvements. C1 [James, G. F.; McHale, G. B.; Arnold, P. A.; Runtal, A. S.; Cardinale, P. S.; Pades, L. S.] Lawrence Livermore Natl Lab, Natl Ignit Facil, 7000 East Ave, Livermore, CA 94550 USA. RP James, GF (reprint author), Lawrence Livermore Natl Lab, Natl Ignit Facil, 7000 East Ave, Livermore, CA 94550 USA. NR 4 TC 0 Z9 0 U1 2 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2380-808X BN 978-1-4799-4047-9; 978-1-4673-7323-4 J9 IEEE INT POWER MODUL PY 2014 BP 178 EP 181 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BE3FS UT WOS:000370659000046 ER PT S AU VanGordon, JA Kovaleski, SD Gall, BB Norgard, P Baxter, EA Kwon, JW Dale, GE AF VanGordon, James A. Kovaleski, Scott D. Gall, Brady B. Norgard, Peter Baxter, Emily A. Kwon, Jae Wan Dale, Gregory E. BE Garner, AL TI Characterization of High-Voltage Lithium Niobate Piezoelectric Transformers SO 2014 IEEE INTERNATIONAL POWER MODULATOR AND HIGH VOLTAGE CONFERENCE (IPMHVC) SE IEEE International Power Modulator and High Voltage Conference LA English DT Proceedings Paper CT IEEE International Power Modulator and High Voltage Conference (IPMHVC) CY JUN 01-05, 2014 CL Santa Fe, NM SP IEEE, IEEE Dielectr & Elect Insulat Soc, Dean Technol, Gen Atom, HVR, Matsusada Precis, ScandiNova, BEHLKE, TDK Lamda, Stangenes Ind Inc, Diversified Technol Inc, NWL, Ultra Elect, RFI, FILTRON, Stanley, Pearson Electronics, 5S, Continental Elect Corp, Dawonsys, Jema, GMWAssociates, SCHOTT, Barth Elect Inc, BiRa Syst, METEK, TREK, DYNAPOWER Co, e2v, Caton DE Piezoelectric transformer; electron beam; compact high voltage; high transformation ratio AB Piezoelectric transformers (PTs) are capable of generating the high accelerating potentials required for many charged-particle beam applications. However, the PTs need to be characterized during operation as an accelerator for such beam loads. PT characteristics such as internal stress, electric field, and electric potential can provide insight into the optimal operating conditions for a given application. Measurement of internal stress can be used to ensure that the single-crystal lithium niobate (LiNbO3()) PT does not exceed the fracture limit. Internal electric field and potential can be used to determine the accelerating potential created by the PT. Internal parameters such as these have been measured using an optical diagnostic that relies on the inherent photoelastic and electro-optic properties of lithium niobate. Beam currents have been determined using least-squares curve fitting with experimental and modeled results. Further characterization of the beam interactions with the PT was done by examining the direct bremsstrahlung x-ray spectra that were produced and the x-ray fluorescence peaks excited by the source. This paper presents a variety of PT characterization results under varied PT operating conditions. C1 [VanGordon, James A.; Kovaleski, Scott D.; Gall, Brady B.; Norgard, Peter; Baxter, Emily A.; Kwon, Jae Wan] Univ Missouri, Dept Elect & Comp Engn, Columbia, MO 65211 USA. [Dale, Gregory E.] Los Alamos Natl Lab, High Power Electrodynam Grp, Los Alamos, NM 87545 USA. RP VanGordon, JA (reprint author), Univ Missouri, Dept Elect & Comp Engn, Columbia, MO 65211 USA. NR 25 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2380-808X BN 978-1-4799-4047-9; 978-1-4673-7323-4 J9 IEEE INT POWER MODUL PY 2014 BP 580 EP 583 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BE3FS UT WOS:000370659000150 ER PT S AU Anderson, DE Peplov, V Solley, DJ Wezensky, M AF Anderson, David E. Peplov, Vladimir Solley, Dennis J. Wezensky, Mark BE Garner, AL TI Recent Developments in the Improvement Campaign for the High Voltage Converter Modulator at the Spallation Neutron Source SO 2014 IEEE INTERNATIONAL POWER MODULATOR AND HIGH VOLTAGE CONFERENCE (IPMHVC) SE IEEE International Power Modulator and High Voltage Conference LA English DT Proceedings Paper CT IEEE International Power Modulator and High Voltage Conference (IPMHVC) CY JUN 01-05, 2014 CL Santa Fe, NM SP IEEE, IEEE Dielectr & Elect Insulat Soc, Dean Technol, Gen Atom, HVR, Matsusada Precis, ScandiNova, BEHLKE, TDK Lamda, Stangenes Ind Inc, Diversified Technol Inc, NWL, Ultra Elect, RFI, FILTRON, Stanley, Pearson Electronics, 5S, Continental Elect Corp, Dawonsys, Jema, GMWAssociates, SCHOTT, Barth Elect Inc, BiRa Syst, METEK, TREK, DYNAPOWER Co, e2v, Caton AB The High Voltage Converter Modulator (HVCM) systems at the Spallation Neutron Source (SNS) are the primary power sources for the klystrons that supply RF power to the H-beam. The availability of the HVCMs exceeds 99% due to numerous improvements that have been implemented since SNS operations began in 2006. However, the HVCMs continue to operate in open-loop mode that results in significant voltage droop within each pulse. Control margin in the low-level RF control system is becoming a limitation as beam intensity and pulse length are increased to raise the beam power on target to 1.4 MW. This paper will discuss recent progress towards improving the pulse characteristics delivered by the HVCM systems and additional steps being pursued to further improve the system reliability. Alternative modulation schemes for switching the IGBTs, alternative system topologies and various enabling technologies to accomplish these goals will be the primary focus. The motivation, design details, test results and implementation will be presented. C1 [Anderson, David E.; Peplov, Vladimir; Solley, Dennis J.; Wezensky, Mark] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Anderson, DE (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2380-808X BN 978-1-4799-4047-9; 978-1-4673-7323-4 J9 IEEE INT POWER MODUL PY 2014 BP 672 EP 675 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BE3FS UT WOS:000370659000174 ER PT S AU Peplov, VV Anderson, DE Solley, DJ AF Peplov, Vladimir V. Anderson, David E. Solley, Dennis J. BE Garner, AL TI Testing Single Phase IGBT H-Bridge Switch Plates for the High Voltage Converter Modulator at the Spallation Neutron Source SO 2014 IEEE INTERNATIONAL POWER MODULATOR AND HIGH VOLTAGE CONFERENCE (IPMHVC) SE IEEE International Power Modulator and High Voltage Conference LA English DT Proceedings Paper CT IEEE International Power Modulator and High Voltage Conference (IPMHVC) CY JUN 01-05, 2014 CL Santa Fe, NM SP IEEE, IEEE Dielectr & Elect Insulat Soc, Dean Technol, Gen Atom, HVR, Matsusada Precis, ScandiNova, BEHLKE, TDK Lamda, Stangenes Ind Inc, Diversified Technol Inc, NWL, Ultra Elect, RFI, FILTRON, Stanley, Pearson Electronics, 5S, Continental Elect Corp, Dawonsys, Jema, GMWAssociates, SCHOTT, Barth Elect Inc, BiRa Syst, METEK, TREK, DYNAPOWER Co, e2v, Caton AB Three IGBT H-bridge switching networks are used in each High Voltage Converter Modulator (HVCM) system at the Spallation Neutron Source (SNS) to generate drive currents to three boost transformer primaries switching between positive and negative bus voltages at 20 kHz. Every switch plate assembly is tested before installing it into an operational HVCM. A Single Phase Test Stand has been built for this purpose, and it is used for adjustment, measurement and testing of different configurations of switch plates. This paper will present a description of the Test Stand configuration and discuss the results of testing switch plates with two different types of IGBT gate drivers currently in use on the HVCM systems. Comparison of timing characteristics of the original and new drivers and the resulting performance reinforces the necessity to replace the original H-bridge network drivers with the upgraded units. C1 [Peplov, Vladimir V.; Anderson, David E.; Solley, Dennis J.] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Peplov, VV (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 2380-808X BN 978-1-4799-4047-9; 978-1-4673-7323-4 J9 IEEE INT POWER MODUL PY 2014 BP 676 EP 679 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA BE3FS UT WOS:000370659000175 ER PT S AU Williams, JT Bacon, LD Walker, MJ Zeek, EC AF Williams, Jeffery T. Bacon, Larry D. Walker, Michael J. Zeek, Erik C. GP IEEE TI An Active Thevenin Equivalent Network Approach to EMI/EMC Problems SO 2014 IEEE INTERNATIONAL SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY (EMC) SE IEEE International Symposium on Electromagnetic Compatibility LA English DT Proceedings Paper CT IEEE International Symposium on Electromagnetic Compatibility (EMC) CY AUG 03-08, 2014 CL Raleigh, NC SP IEEE, EMC Soc, ANDRO, ARRL, FEKO, GAUSS INSTRUMENTS, INFIELD Sci Inc, RETLIF TESTING LABS, ETS LINDGREN, ENR Seven Mountains Sci Inc, Evaluat Engn, IEEE Antennas & Propagat Magazine, IEEE Microwave Magazine, ATER, In Compliance Same Page Publishing Inc, ITEM Interference Technol, Microwave Journal, Safety & EMC Magazine, Webcom Commun Corp, Wireless Design & Dev, ECN AB Nonlinear responses of the semiconductor devices in electronic devices can change the impedances seen at the circuit nodes, changing the boundary conditions encountered by impressed electromagnetic fields and thus the field coupling. We have developed the Active THevenin Equivalent Network Approach (ATHENA), which allows us to include electromagnetic coupling in nonlinear circuit simulations in a bidirectional, fully consistent way. Including the coupling in the circuit simulation self-consistently is important because it allows us to predict responses to EMI/EMC both correctly and efficiently, opening the way to predicting response statistics. C1 [Williams, Jeffery T.; Bacon, Larry D.; Walker, Michael J.; Zeek, Erik C.] Sandia Natl Labs, Directed Energy Special Applicat, POB 5800, Albuquerque, NM 87185 USA. RP Williams, JT (reprint author), Sandia Natl Labs, Directed Energy Special Applicat, POB 5800, Albuquerque, NM 87185 USA. 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 2158-110X BN 978-1-4799-5545-9 J9 IEEE INT SYMP ELEC PY 2014 BP 878 EP 881 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BG9OA UT WOS:000393471300159 ER PT S AU Schneider, K AF Schneider, Kevin GP IEEE TI Microgrids as a Resiliency Resource SO 2014 IEEE INTERNATIONAL TEST CONFERENCE (ITC) SE International Test Conference Proceedings LA English DT Proceedings Paper CT 45th IEEE International Test Conference (ITC) CY OCT 21-23, 2014 CL Seattle, DC SP IEEE Comp Soc, Test Technol Tech Council, IEEE, IEEE Philadelphia Sect C1 [Schneider, Kevin] Pacific NW Natl Lab, Richland, WA 99352 USA. RP Schneider, K (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1089-3539 BN 978-1-4799-4722-5 J9 INT TEST CONF P PY 2014 PG 1 WC Computer Science, Hardware & Architecture; Engineering, Electrical & Electronic SC Computer Science; Engineering GA BE3GX UT WOS:000370703300011 ER PT S AU DeVoto, D Paret, P Mihalic, M Narumanchi, S Bar-Cohen, A Matin, K AF DeVoto, Douglas Paret, Paul Mihalic, Mark Narumanchi, Sreekant Bar-Cohen, Avram Matin, Kaiser GP IEEE TI Thermal Performance and Reliability Characterization of Bonded Interface Materials (BIMs) SO 2014 IEEE INTERSOCIETY CONFERENCE ON THERMAL AND THERMOMECHANICAL PHENOMENA IN ELECTRONIC SYSTEMS (ITHERM) SE InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems LA English DT Proceedings Paper CT 14th InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm) CY MAY 27-30, 2014 CL Orlando, FL SP IEEE, Mentor Gr, Microsanj, Anveshak, GE Res, Raytheon Corp, IBM Corp, Hewlett Packard, Binghamton Univ, S3IP Ctr DE thermal interface; bonded interface material; accelerated testing; temperature cycling; aging; thermal resistance; transient technique; steady-state technique AB Thermal interface materials (TIMs) are an important enabler for low thermal resistance and reliable electronics packaging for a wide array of applications. There is a trend towards bonded interface materials (BIMs) because of their potential for low thermal resistance (<1 mm(2)-K/W). However, due to coefficient of thermal expansion mismatches between various layers of a package, thermomechanical stresses are induced in BIMs and the package can be prone to failures and integrity risks. Deteriorated interfaces can result in high thermal resistance in the package and degradation and/or failure of the electronics. The Defense Advanced Research Projects Agency's (DARPA) Thermal Management Technologies (TMT) Program has addressed this challenge, supporting the development of mechanically compliant, low resistivity nano-thermal interface (NTI) materials. Prior development of these materials resulted in samples that met DARPA's initial thermal performance and synthesis metrics. In this present work, we describe the testing procedure and report the results of thermal performance and reliability characterization of an initial sample set of three different NTI-BIMs tested at the National Renewable Energy Laboratory. C1 [DeVoto, Douglas; Paret, Paul; Mihalic, Mark; Narumanchi, Sreekant] Natl Renewable Energy Lab, Golden, CO 80401 USA. [Bar-Cohen, Avram; Matin, Kaiser] Def Adv Res Projects Agcy, Arlington, VA 22203 USA. RP DeVoto, D (reprint author), Natl Renewable Energy Lab, 15013 Denver West Pkwy, Golden, CO 80401 USA. EM sreekant.narumanchi@nrel.gov NR 18 TC 2 Z9 2 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1936-3958 BN 978-1-4799-5267-0 J9 INTSOC CONF THERMAL PY 2014 BP 409 EP 417 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA BE0PT UT WOS:000366567000054 ER PT S AU Zeighami, R Coles, H Saunders, WA Branton, S AF Zeighami, Roy Coles, Henry Saunders, Winston A. Branton, Steve GP IEEE TI Thermal Performance Modeling of Hybrid Liquid-Air Cooled Servers SO 2014 IEEE INTERSOCIETY CONFERENCE ON THERMAL AND THERMOMECHANICAL PHENOMENA IN ELECTRONIC SYSTEMS (ITHERM) SE InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems LA English DT Proceedings Paper CT 14th InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm) CY MAY 27-30, 2014 CL Orlando, FL SP IEEE, Mentor Gr, Microsanj, Anveshak, GE Res, Raytheon Corp, IBM Corp, Hewlett Packard, Binghamton Univ, S3IP Ctr DE server; data center; liquid; air; cooling; power; energy reuse; water cooling AB This paper discusses data center scale performance characterization of hybrid liquid-air cooling solutions for a full 42U rack of servers. Using data collected in a production data center at Lawrence Berkeley Laboratories, we interpret the results with a simple three parameter model which allows characterization of the major factors affecting heat recovery efficiency of the system. The model is shown to agree with a broad set of data under a variety of temperature and workload conditions. To our knowledge, this is the first large scale characterization of a hybrid cooling solution's performance in terms relevant to data center operation. We discuss how this method can be extended to other systems for meaningful comparison of solution performance. C1 [Zeighami, Roy] Cisco Corp, Richardson, TX 75082 USA. [Coles, Henry] Lawrence Berkeley Labs, Berkeley, CA 94720 USA. [Saunders, Winston A.] Intel Corp, Hillsboro, OR 97124 USA. [Branton, Steve] Asetek Inc, San Jose, CA 95138 USA. RP Zeighami, R (reprint author), Cisco Corp, 2200 East President George Bush Highway, Richardson, TX 75082 USA. EM rzeigham@cisco.com; hccoles@lbl.gov; sbr@asetek.com 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 SN 1936-3958 BN 978-1-4799-5267-0 J9 INTSOC CONF THERMAL PY 2014 BP 583 EP 587 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA BE0PT UT WOS:000366567000076 ER PT S AU Bennion, K Cousineau, J Lustbader, J Narumanchi, S AF Bennion, Kevin Cousineau, Justin Lustbader, Jason Narumanchi, Sreekant GP IEEE TI Novel Power Electronics Three-Dimensional Heat Exchanger SO 2014 IEEE INTERSOCIETY CONFERENCE ON THERMAL AND THERMOMECHANICAL PHENOMENA IN ELECTRONIC SYSTEMS (ITHERM) SE InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems LA English DT Proceedings Paper CT 14th InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm) CY MAY 27-30, 2014 CL Orlando, FL SP IEEE, Mentor Gr, Microsanj, Anveshak, GE Res, Raytheon Corp, IBM Corp, Hewlett Packard, Binghamton Univ, S3IP Ctr DE power electronics; thermal management; electric drive; water-ethylene glycol; aluminum extrusions; electric vehicle; inverter; heat exchanger AB Electric-drive systems, which include electric machines and power electronics, are a key enabling technology to meet increasing automotive fuel economy standards, improve energy security, address environmental concerns, and support economic development. Enabling cost-effective electric-drive systems requires reductions in inverter power semiconductor area, which increases challenges associated with heat removal. In this paper, we demonstrate an integrated approach to the design of thermal management systems for power semiconductors that matches the passive thermal resistance of the packaging with the active convective cooling performance of the heat exchanger. The heat exchanger concept builds on existing semiconductor thermal management improvements described in literature and patents, which include improved bonded interface materials, direct cooling of the semiconductor packages, and double-sided cooling. The key difference in the described concept is the achievement of high heat transfer performance with less aggressive cooling techniques by optimizing the passive and active heat transfer paths. An extruded aluminum design was selected because of its lower tooling cost, higher performance, and scalability in comparison to cast aluminum. Results demonstrated a 102% heat flux improvement and a package heat density improvement over 30%, which achieved the thermal performance targets. C1 [Bennion, Kevin; Cousineau, Justin; Lustbader, Jason; Narumanchi, Sreekant] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Bennion, K (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM kevin.bennion@nrel.gov NR 40 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1936-3958 BN 978-1-4799-5267-0 J9 INTSOC CONF THERMAL PY 2014 BP 1055 EP 1063 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA BE0PT UT WOS:000366567000141 ER PT S AU Waye, SK Narumanchi, S Mihalic, M Moreno, G Bennion, K Jeffers, J AF Waye, Scot K. Narumanchi, Sreekant Mihalic, Mark Moreno, Gilbert Bennion, Kevin Jeffers, Jana GP IEEE TI Advanced Liquid Cooling for a Traction Drive Inverter Using Jet Impingement and Microfinned Enhanced Surfaces SO 2014 IEEE INTERSOCIETY CONFERENCE ON THERMAL AND THERMOMECHANICAL PHENOMENA IN ELECTRONIC SYSTEMS (ITHERM) SE InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems LA English DT Proceedings Paper CT 14th InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm) CY MAY 27-30, 2014 CL Orlando, FL SP IEEE, Mentor Gr, Microsanj, Anveshak, GE Res, Raytheon Corp, IBM Corp, Hewlett Packard, Binghamton Univ, S3IP Ctr DE jet-impingement; enhanced surfaces; microfinned surfaces; single-phase liquid cooling; power electronics; inverter thermal management; heat transfer ID HEAT-TRANSFER; ARRAY IMPINGEMENT; ROUGHNESS AB This study evaluates a jet impingement based cooling strategy combined with microfinned enhanced surfaces as a means of improving thermal management for power electronic devices. For comparison, a baseline channel flow heat exchanger and jet impingement on plain surfaces are characterized. The jets, augmented with enhanced microfinned surfaces, provide localized cooling to areas heated by the insulated-gate bipolar transistors and diode devices. Lighter materials and simpler manufacturing while managing required pumping power increase the overall performance while reducing weight, volume, and cost. Computational fluid dynamics modeling validated by experiments was used to characterize the baseline as well as jet-impingement-based heat exchangers at typical automotive flow rates using a 50%-50% mixture by volume of water and ethylene glycol. The three cooling configurations were tested at full inverter power (40 to 100 kW output power) on a dynamometer. An increased thermal performance was observed for the jet-impingement configurations. Experiments were also performed to investigate the long-term reliability of the jets impinging on enhanced surfaces. C1 [Waye, Scot K.; Narumanchi, Sreekant; Mihalic, Mark; Moreno, Gilbert; Bennion, Kevin; Jeffers, Jana] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Waye, SK (reprint author), Natl Renewable Energy Lab, 15013 Denver West Pkwy, Golden, CO 80401 USA. EM scot.waye@nrel.gov NR 31 TC 2 Z9 2 U1 1 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1936-3958 BN 978-1-4799-5267-0 J9 INTSOC CONF THERMAL PY 2014 BP 1064 EP 1073 PG 10 WC Engineering, Electrical & Electronic SC Engineering GA BE0PT UT WOS:000366567000142 ER PT S AU Feng, XH King, C DeVoto, D Mihalic, M Narumanchi, S AF Feng, Xuhui King, Charlie DeVoto, Doug Mihalic, Mark Narumanchi, Sreekant GP IEEE TI Investigation of Thermal Interface Materials Using Phase-Sensitive Transient Thermoreflectance Technique SO 2014 IEEE INTERSOCIETY CONFERENCE ON THERMAL AND THERMOMECHANICAL PHENOMENA IN ELECTRONIC SYSTEMS (ITHERM) SE InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems LA English DT Proceedings Paper CT 14th InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm) CY MAY 27-30, 2014 CL Orlando, FL SP IEEE, Mentor Gr, Microsanj, Anveshak, GE Res, Raytheon Corp, IBM Corp, Hewlett Packard, Binghamton Univ, S3IP Ctr DE Thermal interface materials; phase-sensitive transient thremoreflectance; contact resistance; bulk thermal conductivity; thermophysical properties ID CARBON NANOTUBE ARRAYS; FILMS; CONDUCTIVITY; PERFORMANCE; SILICON AB With increasing power density in electronics packages/modules, thermal resistances at multiple interfaces are a bottleneck to efficient heat removal from the package. In this work, the performance of thermal interface materials such as grease, thermoplastic adhesives and diffusion-bonded interfaces are characterized using the phase-sensitive transient thermoreflectance technique. A multi-layer heat conduction model was constructed and theoretical solutions were derived to obtain the relation between phase lag and the thermal/physical properties. This technique enables simultaneous extraction of the contact resistance and bulk thermal conductivity of the TIMs. With the measurements, the bulk thermal conductivity of Dow TC-5022 thermal grease (70 to 75 mu m bondline thickness) was 3 to 5 W/(m.K) and the contact resistance was 5 to 10 mm(2).K/W. For the Btech thermoplastic material (45 to 80 mu m bondline thickness), the bulk thermal conductivity was 20 to 50 W/(m.K) and the contact resistance was 2 to 5 mm(2) K/W. Measurements were also conducted to quantify the thermal performance of diffusion-bonded interface for power electronics applications. Results with the diffusion-bonded sample showed that the interfacial thermal resistance is more than one order of magnitude lower than those of traditional TIMs, suggesting potential pathways to efficient thermal management. C1 [Feng, Xuhui; King, Charlie; DeVoto, Doug; Mihalic, Mark; Narumanchi, Sreekant] Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Feng, XH (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 30 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1936-3958 BN 978-1-4799-5267-0 J9 INTSOC CONF THERMAL PY 2014 BP 1294 EP 1305 PG 12 WC Engineering, Electrical & Electronic SC Engineering GA BE0PT UT WOS:000366567000173 ER PT S AU Obert, J Pivkina, I Huang, H Cao, HP AF Obert, James Pivkina, Inna Huang, Hong Cao, Huiping GP IEEE Comp Soc TI Dynamically Differentiated Multipath Security in Fixed Bandwidth Networks SO 2014 IEEE MILITARY COMMUNICATIONS CONFERENCE: AFFORDABLE MISSION SUCCESS: MEETING THE CHALLENGE (MILCOM 2014) SE IEEE Military Communications Conference LA English DT Proceedings Paper CT 33rd Annual IEEE Military Communications Conference on Affordable Mission Success - Meeting the Challenge (MILCOM) CY OCT 06-08, 2014 CL Raytheon, Baltimore, MD SP IEEE, IEEE Comp Soc, IEEE Commun Soc, AFCEA HO Raytheon DE Multipath Security; Information Assurance; Anomaly Detection AB Networks can be secured using a secure quality of service approach in which a sender disperses data along multiple secure paths. In this secure multipath approach, a portion of the data from the sender is transmitted over each path on fixed bandwidth networks, and the receiver assembles the data fragments that arrive. The research presented explores the effects of cloud infrastructure attack scenarios, and gauges the threat levels along each path. Optimal sampling and compression via compressed sensing is employed in order to minimize the possibility of dropped packets and missed attacks. The probability of the presence of specific attack signatures along each network path is determined using statistical learning techniques. Path information assurance levels are derived using these probabilities and encryption strengths are dynamically increased along those paths found to be most vulnerable. As compared to statically employed path encryption schemes, the devised methods in this research significantly increase data throughput on fixed bandwidth networks. C1 [Obert, James] Sandia Natl Labs, Cyber R&D Solut, POB 5800, Albuquerque, NM 87185 USA. [Pivkina, Inna; Huang, Hong; Cao, Huiping] New Mexico State Univ, Dept Comp Sci, Las Cruces, NM 88003 USA. [Pivkina, Inna; Huang, Hong; Cao, Huiping] New Mexico State Univ, Dept Elect Engn, Las Cruces, NM 88003 USA. RP Obert, J (reprint author), Sandia Natl Labs, Cyber R&D Solut, POB 5800, Albuquerque, NM 87185 USA. EM jobert@sandia.gov; inna@nsmu.edu; hhuang@nsmu.edu; hcao@nsmu.edu NR 14 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 2155-7578 BN 978-1-4799-6770-4 J9 IEEE MILIT COMMUN C PY 2014 BP 88 EP 93 DI 10.1109/MILCOM.2014.22 PG 6 WC Telecommunications SC Telecommunications GA BE2QJ UT WOS:000369851400014 ER PT S AU Olama, MM Killough, SM Kuruganti, T Carroll, TE AF Olama, Mohammed M. Killough, Stephen M. Kuruganti, Teja Carroll, Thomas E. GP IEEE Comp Soc TI Design, Implementation, and Evaluation of a Hybrid DS/FFH Spread-Spectrum Radio Transceiver SO 2014 IEEE MILITARY COMMUNICATIONS CONFERENCE: AFFORDABLE MISSION SUCCESS: MEETING THE CHALLENGE (MILCOM 2014) SE IEEE Military Communications Conference LA English DT Proceedings Paper CT 33rd Annual IEEE Military Communications Conference on Affordable Mission Success - Meeting the Challenge (MILCOM) CY OCT 06-08, 2014 CL Raytheon, Baltimore, MD SP IEEE, IEEE Comp Soc, IEEE Commun Soc, AFCEA HO Raytheon DE Hybrid spread-spectrum; direct-sequence; frequency-hopping; interference; jamming; data rate; hopping sequence; Field Programmable Gate Array (FPGA); direct digital synthesizer; receiver sensitivity ID CHANNELS AB In recent years there has been great interest in using hybrid spread-spectrum (HSS) techniques for commercial applications, particularly in the Smart Grid, in addition to their inherent uses in military communications. This is because HSS can accommodate high data rates with high link integrity, even in the presence of significant multipath effects and interfering signals. A highly useful form of this transmission technique for many types of command, control, and sensing applications is the specific code-related combination of standard direct-sequence modulation with "fast" frequency-hopping, denoted hybrid DS/FFH, wherein multiple frequency hops occur within a single data-bit time. In this paper, we present the efforts carried out at Oak Ridge National Laboratory toward exploring the design, implementation, and evaluation of a hybrid DS/FFH spread-spectrum radio transceiver using a single Field Programmable Gate Array (FPGA). The FPGA allows the various subsystems to quickly communicate with each other and thereby maintain tight synchronization. We also investigate various hopping sequences against robustness to interference and jamming. Experimental results are presented that show the receiver sensitivity, radio data-rate/bit-error evaluations, and jamming and interference rejection capabilities of the implemented hybrid DS/FFH spread-spectrum system under widely varying design parameters. C1 [Olama, Mohammed M.; Killough, Stephen M.; Kuruganti, Teja] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. [Carroll, Thomas E.] Pacific NW Natl Lab, Richland, WA 99352 USA. RP Olama, MM (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM olamahussemmx@ornl.gov; killoughsm@ornl.gov; kurugantipv@ornl.gov; Thomas.Carroll@pnnl.gov NR 12 TC 0 Z9 0 U1 1 U2 2 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA SN 2155-7578 BN 978-1-4799-6770-4 J9 IEEE MILIT COMMUN C PY 2014 BP 1368 EP 1373 DI 10.1109/MILCOM.2014.227 PG 6 WC Telecommunications SC Telecommunications GA BE2QJ UT WOS:000369851400219 ER PT J AU Azmoun, B Purschke, ML Pak, R Phipps, M Franz, A Woody, C AF Azmoun, B. Purschke, M. L. Pak, R. Phipps, M. Franz, A. Woody, C. GP IEEE TI Initial Studies of a Short Drift GEM Tracking Detector SO 2014 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC) LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium / Medical Imaging Conference (NSS/MIC) CY NOV 08-15, 2014 CL Seattle, WA SP IEEE AB In an effort to develop new tracking detectors for future experiments at RHIC, we have been developing a short drift GEM tracking detector that has the potential to provide a position resolution similar to 100 microns even at large angles. We have conducted new high precision studies of our prototype short drift GEM detector at the Fermilab test beam facility in October 2013 and February 2014 which confirm initial studies carried out at CERN in 2012. The detector is made up of a triple GEM stack with a 16mm drift gap and is read out using COMPASS style x-y strips, in conjunction with a SRS/APV-25 DAQ system. The charge deposited in the drift gap from incident particles is drifted onto the readout plane, where the charge arrival time is used to reconstruct particle position and angle. Although the old and new measurements show very nice agreement, the older measurements suffer from a relatively large uncertainty in the position of the reference track, resulting in the unfolding of an error about as large as the resolution of the GEM detector itself. This paper will describe the important aspects of the newer, higher precision measurement, and will report on improvements in the data analysis, which includes a method that uses the charge weighted centroid, together with the reconstructed vector to get a better measure of the position than either the centroid or vector alone. C1 [Azmoun, B.; Purschke, M. L.; Pak, R.; Phipps, M.; Franz, A.; Woody, C.] Brookhaven Natl Lab, Upton, NY 11973 USA. RP Azmoun, B (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. FU U.S. Department of Energy [DE-AC02-98CH10886] FX This work was supported in part by the U.S. Department of Energy under Prime Contract No. DE-AC02-98CH10886. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-6097-2 PY 2014 PG 2 WC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BG9AN UT WOS:000392917500315 ER PT J AU Badgett, W Hahn, SR Torretta, D Meier, J Gunderson, J Osterholm, D Saranen, D AF Badgett, William Hahn, Steve R. Torretta, Donatella Meier, Jerry Gunderson, Jeffrey Osterholm, Denise Saranen, David GP IEEE TI Upgrade of the Minos plus Experiment Data Acquisition for the High Energy NuMI Beam Run SO 2014 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC) LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium / Medical Imaging Conference (NSS/MIC) CY NOV 08-15, 2014 CL Seattle, WA SP IEEE AB The Minos+ experiment is an extension of the Minos experiment at a higher energy and more intense neutrino beam, with the data collection having begun in the fall of 2013. The neutrino beam is provided by the Neutrinos from the Main Injector (NuMI) beam-line at Fermi National Accelerator Laboratory (Fermilab). The detector apparatus consists of two main detectors, one underground at Fermilab and the other in Soudan, Minnesota with the purpose of studying neutrino oscillations at a base line of 735 km. The original data acquisition system has been running for several years collecting data from NuMI, but with the extended run from 2013, parts of the system needed to be replaced due to obsolescence, reliability problems, and data throughput limitations. Specifically, we have replaced the front-end readout controllers, event builder, and data acquisition computing and trigger processing farms with modern, modular and reliable devices with few single points of failure. The new system is based on gigabit Ethernet TCP/IP communication to implement the event building and concatenation of data from many front-end VME readout crates. The simplicity and partitionability of the new system greatly eases the debugging and diagnosing process. The new system improves throughput by about a factor of three compared to the old system, up to 800 megabits per second, and has proven robust and reliable in the current run. C1 [Badgett, William; Hahn, Steve R.; Torretta, Donatella] Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. [Meier, Jerry; Gunderson, Jeffrey; Osterholm, Denise] Soudan Underground Lab, Soudan, MN 55782 USA. RP Badgett, W (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. EM badgett@fnal.gov FU [DE-ACO2-07CH11359] FX Manuscript received November 30, 2014. Fermi National Accelerator Laboratory is operated by Fermi Research Alliance, LLC under Contract No. DE-ACO2-07CH11359 with the United States Department of Energy NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-6097-2 PY 2014 PG 3 WC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BG9AN UT WOS:000392917500400 ER PT J AU Bell, ZW Hornback, DE Hu, MZ Neal, JS AF Bell, Zane W. Hornback, D. E. Hu, M. Z. Neal, J. S. GP IEEE TI Wavelength-Based Neutron/Gamma Ray Discrimination in CLYC SO 2014 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC) LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium / Medical Imaging Conference (NSS/MIC) CY NOV 08-15, 2014 CL Seattle, WA SP IEEE ID GAMMA-RAYS AB We investigated the optical components of Cs(2)LiYC1(6):Ce (CLYC) as a possible path to particle discrimination by measuring the effects of optical filters on the shape of the waveform and comparing filtered waveforms to unfiltered ones. Crystals packaged with two optical windows were viewed by two photomultiplier tubes operated in coincidence to be certain that the signals from the same event were analyzed. We applied long-pass optical filters with cut-off wavelengths from 280 to 455 mu, and bandpass filters with cutoff wavelengths at 313, 350, 385, and 425 mu. Waveforms from gamma rays were significantly sharpened by the 313 nm bandpass filter because this filter cut out self-trapped exciton luminescence, while neutron waveforms were largely unaffected by filtering. Cumulative distribution functions generated from average filtered waveforms indicate that the neutron/gamma assignment can be made 44 ns by applying a Kolmogorov-Smirnov test comparing an acquired waveform to the average filtered waveforms. C1 [Bell, Zane W.; Hornback, D. E.; Hu, M. Z.; Neal, J. S.] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Bell, ZW (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM bellzw@ornl.gov; hornbackde@ornl.gov; hum1@ornl.gov; nealjs1@ornl.gov FU NA-22; Office of Defense Nuclear Nonproliferation RD FX This work was supported by NA-22, the Office of Defense Nuclear Nonproliferation R&D. 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 BN 978-1-4799-6097-2 PY 2014 PG 8 WC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BG9AN UT WOS:000392917500453 ER PT J AU Bilki, B AF Bilki, Burak CA CALICE Collaboration GP IEEE TI Status of the CALICE Digital Hadron Calorimeter SO 2014 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC) LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium / Medical Imaging Conference (NSS/MIC) CY NOV 08-15, 2014 CL Seattle, WA SP IEEE AB A novel approach named Particle Flow Algorithms is proposed to measure the jets of the hadronic decays of electroweak bosons in a future lepton collider with 3-4% resolution. The Particle Flow Algorithms attempt to measure each particle in a hadronic jet individually, using the detector subsystem providing the best energy/momentum resolution. In this paradigm, the role of the hadronic calorimeter is to measure the neutral hadron component of the hadronic jets. In this context, the CALICE Collaboration developed the Digital Hadron Calorimeter, which uses Resistive Plate Chambers as active media. The 1-bit resolution (digital) readout of 1 x 1 cm(2) pads achieves a world record in the number of readout channels already at the prototyping stage. Here we report on the status of the Digital Hadron Calorimeter with results from several Fermilab test beam campaigns with an emphasis on the intricate calibration procedures. C1 [Bilki, Burak] Univ Iowa, Iowa City, IA 52242 USA. [Bilki, Burak] Argonne Natl Lab, Argonne, IL 60439 USA. RP Bilki, B (reprint author), Univ Iowa, Iowa City, IA 52242 USA. EM burak-bilki@uiowa.edu 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 978-1-4799-6097-2 PY 2014 PG 5 WC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BG9AN UT WOS:000392917500410 ER PT J AU Bilki, B AF Bilki, Burak GP IEEE TI Secondary Emission Calorimetry R&D SO 2014 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC) LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium / Medical Imaging Conference (NSS/MIC) CY NOV 08-15, 2014 CL Seattle, WA SP IEEE AB Electromagnetic calorimetry in high-radiation environments (e.g. forward regions of lepton and hadron collider detectors) is quite challenging. Although the total absorption crystal calorimeters have superior performance as electromagnetic calorimeters, the availability and the cost of the radiation-hard crystals are the two limiting factors in terms of radiation-tolerant implementations. Sampling calorimeters utilizing Silicon sensors as the active media are also favorable in terms of performance but are challenged by high radiation environments. In order to provide a solution for such implementations, we developed a radiation-hard, fast and cost effective technique, secondary emission calorimetry, and tested prototype secondary emission sensors in test beams. In a secondary emission detector module, secondary emission electrons are generated from a cathode when charged hadron or electromagnetic shower particles penetrate the secondary emission sampling module that is placed between absorber materials. The generated secondary emission electrons are then multiplied in a similar way as the photoelectrons in photomultiplier tubes. Here we report on the principles of secondary emission calorimetry, the results from recent test beams as well as the Monte Carlo simulations for the test beam setup, and the performance of a projected, large-scale secondary emission electromagnetic calorimeter. C1 [Bilki, Burak] Univ Iowa, Iowa City, IA 52242 USA. [Bilki, Burak] Argonne Natl Lab, Argonne, IL 60439 USA. RP Bilki, B (reprint author), Univ Iowa, Iowa City, IA 52242 USA. EM burak-bilki@uiowa.edu NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-6097-2 PY 2014 PG 5 WC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BG9AN UT WOS:000392917500411 ER PT J AU Bilki, B AF Bilki, Burak CA CMS Collaboration GP IEEE TI CMS Forward Calorimeters Phase II Upgrade SO 2014 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC) LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium / Medical Imaging Conference (NSS/MIC) CY NOV 08-15, 2014 CL Seattle, WA SP IEEE ID PERFORMANCE; LHC; CALIBRATION; PARTICLE; DESIGN; WEDGES; BOSON AB The Phase II Upgrade of the CMS forward calorimeters (electromagnetic and hadronic) originates from the fact that these calorimeters will not be sufficiently performant with the expected High Luminosity LHC conditions, planned to be started in 2025. The major challenge is to preserve/improve the high performance of the current forward detectors with new devices that can withstand the unprecedented radiation levels and disentangle the very large event pileup. CMS elected two design concepts to be presented in the Phase II Upgrade Technical Proposal: Shashlik electromagnetic calorimeter + Hadronic Endcap Rebuild, and High Granularity Calorimeter. The former concept is based on reconstructing the endcap electromagnetic calorimeter with a shashlik design and replacing the active media of the endcap hadron calorimeter with radiation tolerant active media with a possibility to extend the coverage. The latter concept is concentrating on constructing a high granularity (both longitudinally and laterally) calorimeter system with silicon as the active medium for the electromagnetic and the front hadronic sections, and scintillator tiles in the backing hadronic section; all interleaved with absorbers in a sampling calorimeter setup. Here we concentrate on the need for the upgrade, major challenges and the proposed R&D concepts suitable for the Phase II upgrade framework with recent information about the beam tests and laboratory measurements. C1 [Bilki, Burak] Univ Iowa, Iowa City, IA 52242 USA. [Bilki, Burak] Argonne Natl Lab, Argonne, IL 60439 USA. RP Bilki, B (reprint author), Univ Iowa, Iowa City, IA 52242 USA. EM burak-bilki@uiowa.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 BN 978-1-4799-6097-2 PY 2014 PG 5 WC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BG9AN UT WOS:000392917500372 ER PT J AU Braverman, JB Fabris, L Newby, J Hornback, D Ziock, KP AF Braverman, J. B. Fabris, L. Newby, J. Hornback, D. Ziock, K. P. GP IEEE TI Three-Dimensional Event Localization in Bulk Scintillator Crystals Using Optical Coded Apertures SO 2014 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC) LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium / Medical Imaging Conference (NSS/MIC) CY NOV 08-15, 2014 CL Seattle, WA SP IEEE AB Scintillator-based detectors are among the most commonly used methods for detecting ionizing radiation. Scintillators provide a reliable, cost-effective, and simple way to make large-volume detectors. Furthermore, localizing the position of the interactions in three dimensions within the crystals is useful to a wide array of fields. The most straightforward way of doing this is to pair the crystal with a position-sensitive phototransducer (PT). This allows for measurement of the shape of the light spot at the PT plane. Using this information, various methods exist to localize the gamma-ray interaction in the crystal; however, the position resolution worsens the farther the event occurs from the PT plane. To improve on the localization ability, this work uses an optical coded aperture shadow mask between the crystal and the PT. The recorded detector response is used in reconstructing the event over the entire depth of the crystal, and the "sharpest" reconstructed image gives an event's depth. The lateral position is given from the standard coded aperture image reconstruction. Experimental results obtained by emulating a 30-mm-thick crystal using a thin 1-mm-thick NaI(Tl) crystal and different amounts of light pipe between the crystal and the PT plane achieved similar to 1 to 2-mm resolution in all three dimensions throughout most of the 30-mm-thick crystal. C1 [Braverman, J. B.; Ziock, K. P.] Univ Tennessee, Knoxville, TN 37996 USA. [Fabris, L.; Newby, J.; Hornback, D.; Ziock, K. P.] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Braverman, JB (reprint author), Univ Tennessee, Knoxville, TN 37996 USA. EM jbraverm@vols.utk.edu FU Oak Ridge National Laboratory [DE-AC05-000R22725]; U.S. Department of Energy; National Nuclear Security Administration; Office of Defense Nuclear Nonproliferation Research and Development (DNN RD) FX This work was performed under the auspices of the US Department of Energy by Oak Ridge National Laboratory under Contract DE-AC05-000R22725.; The project was funded by the U.S. Department of Energy, National Nuclear Security Administration, Office of Defense Nuclear Nonproliferation Research and Development (DNN R&D). 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 978-1-4799-6097-2 PY 2014 PG 8 WC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BG9AN UT WOS:000392917500515 ER PT J AU Cameron, R Fritz, B Hurlbut, C Kouzes, R Ramey, A Smola, R AF Cameron, Richard Fritz, Bradley Hurlbut, Charles Kouzes, Richard Ramey, Ashley Smola, Richard GP IEEE TI Fogging in Polyvinyl Toluene Scintillators Used in Outdoor Environments SO 2014 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC) LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium / Medical Imaging Conference (NSS/MIC) CY NOV 08-15, 2014 CL Seattle, WA SP IEEE AB It has been observed that large polyvinyl toluene (PVT)-based gamma ray detectors can suffer internal "fogging" when exposed to outdoor environmental conditions over long periods of time. When observed, this change can result in reduced light collection and performance of the PVT. Investigation of the physical cause of these changes has been explored, and a root cause identified. Mitigation procedures and methods are being investigated. C1 [Cameron, Richard; Fritz, Bradley; Kouzes, Richard] PNNL, POB 999, Richland, WA 99352 USA. [Hurlbut, Charles; Ramey, Ashley; Smola, Richard] Eljen Technol, Sweetwater, TX 79556 USA. RP Kouzes, R (reprint author), PNNL, POB 999, Richland, WA 99352 USA. EM Richard.cameron@pnnl.gov; bradley.fritz@pnnl.gov; churlbut@eljentechnology.com; richard.kouzes@pnnl.gov; ashramey@ludlums.com; rsmola@ludlums.com FU Eljen Technology; Department of Homeland Security; U.S. Department of Energy [DE-AC0576RL0 1830] FX Manuscript submitted November 16, 2014. This work was supported in part by Eljen Technology and the Department of Homeland Security. Battelle operates PNNL for the U.S. Department of Energy under contract DE-AC0576RL0 1830. NR 6 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-6097-2 PY 2014 PG 1 WC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BG9AN UT WOS:000392917500511 ER PT J AU Chen, K AF Chen, Kai CA ATLAS Liquid Argon Calorimeter Grp GP IEEE TI Demonstrator System for the Phase-I Upgrade of the Trigger Readout Electronics of the ATLAS Liquid Argon Calorimeters SO 2014 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC) LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium / Medical Imaging Conference (NSS/MIC) CY NOV 08-15, 2014 CL Seattle, WA SP IEEE DE ATLAS; Liquid Argon Calorimeters; Trigger Readout Electronics AB The trigger readout electronics of the ATLAS Liquid Argon (LAr) Calorimeters will be improved for the Phase-I luminosity upgrade of the LHC, to enhance the trigger feature extraction. Signals with higher spatial granularity will be digitized and processed by newly developed front-end and back-end electronics. In order to evaluate the technical and performance aspects, a demonstrator system has been set up, and many off-detector tests have been done. Analog signal parameters including the noise and cross-talk have been measured. Digital signal treatment, and high-speed data transmission have been tested and verified. After a series of tests, the demonstrator system has been installed on the ATLAS detector for the LHC Run 2. C1 [Chen, Kai] Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Chen, K (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 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 978-1-4799-6097-2 PY 2014 PG 3 WC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BG9AN UT WOS:000392917500362 ER PT J AU Chichester, DL Kinlaw, MT Watson, SM Kalter, JM Miller, EC Noonan, WA AF Chichester, David L. Kinlaw, Mathew T. Watson, Scott M. Kalter, Jeffrey M. Miller, Eric C. Noonan, William A. GP IEEE TI Use of Thermal-Neutron Time-Correlated Counting to Analyze Multiplying Assemblies of HEU SO 2014 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC) LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium / Medical Imaging Conference (NSS/MIC) CY NOV 08-15, 2014 CL Seattle, WA SP IEEE AB A series of experiments and numerical simulations using thermal-neutron time-correlated measurements has been performed to determine the neutron multiplication, M, of assemblies of highly-enriched uranium available at Idaho National Laboratory. The experiments used up to 14.4 kg of highly-enriched uranium, including bare assemblies and assemblies reflected with high-density polyethylene, carbon steel, and tungsten. A small Cf-252 source was used to initiate fission chains within the assembly. Both the experiments and the simulations used 6-channel and 8-channel detector systems, each consisting of 3 He proportional counters moderated with polyethylene; data was recorded in list mode for analysis. 'True' multiplication values for each assembly were empirically derived using basic neutron production and loss values determined through simulation. A total of one-hundred sixteen separate measurements were performed using fifty-seven unique measurement scenarios, the multiplication varied from 1.75 to 10.90. This paper presents the results of these comparisons and discusses differences among the various cases. C1 [Chichester, David L.; Kinlaw, Mathew T.; Watson, Scott M.] Idaho Natl Lab, Idaho Falls, ID 83415 USA. [Kalter, Jeffrey M.; Miller, Eric C.; Noonan, William A.] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. RP Chichester, DL (reprint author), Idaho Natl Lab, Idaho Falls, ID 83415 USA. EM david.chichester@inl.gov; mathew.kinlaw@inl.gov; scott.watson@inl.gov; jeffrey.kalter@jhuapl.edu; eric.miller@jhuapl.edu; william.noonan@jhuapl.edu FU Defense Threat Reduction Agency (DTRA) FX The work in this report was sponsored by the Defense Threat Reduction Agency (DTRA). The author's would like to thank Dr. Timothy Leong, our DTRA program manager, for his encouragement of our work on this project, especially his strong support at the inception of the project. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-6097-2 PY 2014 PG 5 WC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BG9AN UT WOS:000392917500341 ER PT J AU Davydov, L Fochuk, P Zakharchenko, A Kutny, V Rybka, A Kovalenko, N Gerasimenko, A Kosmyna, M Sklyarchuk, V Kopach, O Panchuk, O Pudov, A Terzin, I Bolotnikov, AE James, RB AF Davydov, L. Fochuk, P. Zakharchenko, A. Kutny, V. Rybka, A. Kovalenko, N. Gerasimenko, A. Kosmyna, M. Sklyarchuk, V. Kopach, O. Panchuk, O. Pudov, A. Terzin, I. Bolotnikov, A. E. James, R. B. GP IEEE TI Improving and Characterizing the Quality of (Cd,Zn)Te Crystals for Detecting Gamma Radiation SO 2014 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC) LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium / Medical Imaging Conference (NSS/MIC) CY NOV 08-15, 2014 CL Seattle, WA SP IEEE ID CDZNTE SINGLE-CRYSTALS; EXTENDED DEFECTS; PERFORMANCE; GROWTH AB Cd0.9Zn0.1Te ingots were synthesized from pure components (6N purity Cd, Zn, Te, with In and Fe as dopants) and subsequently grown from the melt under an argon overpressure. Graphite crucibles (with and without an inner coating of pyrolytic RN) were used. The temperature gradient in the solidification zone was similar to 15-30 K/cm, and the growth rate was 0.6-1 mm/hour. We investigated the chemical composition, structure, and electrical properties of the grown crystals, and established the relationships with their growth conditions. The beginning, middle, and top of the ingot had n-type conductivity, but slightly different properties. Resistivity reached a maximum in the middle of the ingot ((2.5-5)x10(10) Ohm-cm), and was less at the edges similar to 0.8x10(10) Ohm-cm. The value of the band-gap was minimal in the middle of the ingot (similar to 1.5 eV), and 1.53-1.55 eV at its edges. The compensation degree (N-d/N-a) of the energy level, responsible for the dark conductivity, showed a maximum value at the beginning of the ingot (similar to 60-90 %), and a minimum in the ingot's middle part (1-2 %). High-temperature Hall-effect measurements of CdTe:In samples ([In] similar to 2x10(17) cm(-3)) demonstrated the possibility of restoring the initial sample's high resistivity (decreased after eliminating inclusions using Cd overpressure annealing) by treatment under a Te overpressure at -870 K. The crystals were then used to fabricate Cd(Zn)Te detectors for gamma radiation. C1 [Davydov, L.; Zakharchenko, A.; Kutny, V.; Rybka, A.; Pudov, A.] Kharkov Inst Phys & Technol, Natl Sci Ctr, Kharkov, Ukraine. [Kovalenko, N.; Gerasimenko, A.; Kosmyna, M.; Terzin, I.] Inst Single Crystals, Kharkov, Ukraine. [Fochuk, P.; Sklyarchuk, V.; Panchuk, O.] Chernivtsi Natl Univ, Chernovtsy, Ukraine. [Bolotnikov, A. E.; James, R. B.] Brookhaven Natl Lab, Upton, NY 11973 USA. RP Davydov, L (reprint author), Kharkov Inst Phys & Technol, Natl Sci Ctr, Kharkov, Ukraine. EM ldavydov@kipt.kharkov.ua; p.fochuk@chnu.edu.ua; nazar@isc.kharkov.ua; bolot-nik@bnl.gov; rjames@bnl.gov FU Science and Technology Center of Ukraine (STCU) [P-406]; Department of Eneray's NNSA Global Initiative of Proliferation Prevention; DOE/NNSA's Office of DNN RD FX Manuscript received November 4, 2014. This work was financially supported by Science and Technology Center of Ukraine (STCU) under Project #P-406. We also gratefully acknowledge support for this work from the Department of Eneray's NNSA Global Initiative of Proliferation Prevention and from the DOE/NNSA's Office of DNN R&D. NR 28 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-6097-2 PY 2014 PG 7 WC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BG9AN UT WOS:000392917500537 ER PT J AU Eclov, N Kim, H Chen, HT Chen, CT Ronzhin, A Ramberg, E Los, S Murat, P Wyrwicz, AM Li, LM Kao, CM AF Eclov, Neville Kim, Heejong Chen, H. T. Chen, Chin-Tu Ronzhin, Anatoly Ramberg, Erik Los, Sergey Murat, Pavel Wyrwicz, Alice M. Li, Limin Kao, Chien-Min GP IEEE TI Notch Filtering of RF Interference in PET Data for Simultaneous PET-MR Acquisition SO 2014 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC) LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium / Medical Imaging Conference (NSS/MIC) CY NOV 08-15, 2014 CL Seattle, WA SP IEEE AB We have developed a filtering method to reduce RE interference in PET data for simultaneously acquired PET-MR. Data was acquired from a SiPM-based PET detector coupled to LYSO scintillators using a transmission-line readout scheme and high-speed waveform sampling. The detector was placed within a 9.4 T small animal MR system with either copper or no shielding, and PET data from a low-activity Na-22 source and LYSO background were acquired while MR images were also acquired. MR images showed no image quality degradation. 4% and 7% of PET waveforms demonstrated RE interference with and without shielding. After applying a notch filter, the energy spectrum of RF-affected events was comparable to RF-unaffected events due to improved measurement of the waveform maximum amplitude. Differential time measurements of events on the transmission-line were also improved. This study demonstrates the utility of waveform sampling readout which allows straightforward post processing in PEA data acquisition for simultaneous PET-MR. C1 [Eclov, Neville; Kim, Heejong; Chen, H. T.; Chen, Chin-Tu; Kao, Chien-Min] Univ Chicago, Dept Radiol, Chicago, IL 60637 USA. [Ronzhin, Anatoly; Ramberg, Erik; Los, Sergey; Murat, Pavel] Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. [Wyrwicz, Alice M.; Li, Limin] NorthShore Univ HealthSyst, Res Inst, Evanston, IL USA. RP Eclov, N (reprint author), Univ Chicago, Dept Radiol, Chicago, IL 60637 USA. EM NEclov@UChicago.edu; Heejongkim@UChicago.edu; CKao95@UChicago.edu FU NIH [R01EB016104, T32EB002103]; University of Chicago; Fermilab strategic collaboration seed grants; University of Chicago Institute for Translational Medicine pilot award [CTSA UL1 TR000430] FX This work was supported in part by the NIH grants R01EB016104 and T32EB002103. the University of Chicago and Fermilab strategic collaboration seed grants, and the University of Chicago Institute for Translational Medicine pilot award CTSA UL1 TR000430. NR 8 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-6097-2 PY 2014 PG 3 WC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BG9AN UT WOS:000392917500266 ER PT J AU Egarievwe, SU Kithinji, DK Jow, JO Egarievwe, AA Hales, ZM Martin, RD Chan, W Yang, G Camarda, GS James, RB AF Egarievwe, Stephen U. Kithinji, David K. Jow, Julius O. Egarievwe, Alexander A. Hales, Zaveon M. Martin, Richard D. Chan, Wing Yang, Ge Camarda, Giuseppe S. James, Ralph B. GP IEEE TI Temperature-Gradient Post-Growth Annealing of CdMnTe Wafers for Nuclear Radiation Detection Applications SO 2014 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC) LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium / Medical Imaging Conference (NSS/MIC) CY NOV 08-15, 2014 CL Seattle, WA SP IEEE ID TE INCLUSIONS; CDTE; CRYSTALS; COMPENSATION; PERFORMANCE; GROWTH AB Cadmium Manganese Telluride (CdMnTe) is one of the semiconductor materials recently being developed as X-ray and gamma-ray detectors capable of operating at room temperature. This paper presents the results of temperature gradient post-growth annealing of CdMnTe crystals grown by Bridgman technique. Migration of Te inclusions from the low-temperature side to the high-temperature side of CdMnTe wafers was recorded for an annealing temperature of 715 degrees C at a temperature gradient of 24 degrees C/cm and annealing time of 30 minutes. Size reduction and elimination of Te inclusions were also recorded for a CdMnTe wafer annealed at 730 degrees C with a temperature gradient of 18 degrees C/cm for 18 hours. A two-dimensional analysis of an 810 x 1350 mu m(2) sample area showed a 76% reduction in the Te-inclusion concentration. C1 [Egarievwe, Stephen U.; Kithinji, David K.; Jow, Julius O.; Egarievwe, Alexander A.; Hales, Zaveon M.; Martin, Richard D.; Chan, Wing] Alabama A&M Univ, Nucl Engn & Radiol Sci Ctr, Normal, AL 35762 USA. [Yang, Ge; Camarda, Giuseppe S.; James, Ralph B.] Brookhaven Natl Lab, Dept Nonproliferat & Natl Secur, Upton, NY 11973 USA. RP Egarievwe, SU (reprint author), Alabama A&M Univ, Nucl Engn & Radiol Sci Ctr, Normal, AL 35762 USA. EM stephen.egarievwe@aamu.edu; rjames@bnl.gov FU U.S. Department of Homeland Security, Domestic Nuclear Detection Office [2012-DN077-AR1065-03]; U.S. Nuclear Regulatory Commission [NRC-2710-514]; BNL scientists received; U.S. Department of Energy Office of Defense Nuclear Nonproliferation RD; U.S. Government FX Manuscript received December 30, 2014. This work has been supported by the U.S. Department of Homeland Security, Domestic Nuclear Detection Office, under competitively awarded contract/IAA award number 2012-DN077-AR1065-03. Alabama A&M University researchers were also supported by the U.S. Nuclear Regulatory Commission through award number NRC-2710-514, and BNL scientists received support from the U.S. Department of Energy Office of Defense Nuclear Nonproliferation R&D. These supports do not constitute an expressed or implied endorsement by the U.S. Government. 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 978-1-4799-6097-2 PY 2014 PG 4 WC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BG9AN UT WOS:000392917500545 ER PT J AU Egarievwe, SU Roy, UN Hossain, A James, RB AF Egarievwe, Stephen U. Roy, Utpal N. Hossain, Anwar James, Ralph B. GP IEEE TI Ampoule Carbon Coating and Defects in CdMnTe Crystals intended for Applications in Nuclear Radiation Detection SO 2014 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC) LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium / Medical Imaging Conference (NSS/MIC) CY NOV 08-15, 2014 CL Seattle, WA SP IEEE ID GAMMA-RAY DETECTORS; GROWTH; HGCDTE AB Cadmium manganese telluride (CdMnTe) has a high potential for applications in room-temperature X-ray and gamma-ray detection due to its high average atomic number (48 for Cd, 25 for Mn, and 52 for Te) that is essential to having high stopping power for incident high-energy electromagnetic radiations. A major obstacle in developing CdMnTe detectors is growing crystals free of defects, such as Te inclusions, sub-grain boundary networks, and precipitates. Herein, we present our preliminary results of growing CdMnTe crystals by the Bridgman method; the experiments were aimed at studying the effects of growth parameters, such as ampoule shape, size, and carbon coating thickness on defects in the ingot. Our goal was to optimize growth parameters so to reduce/eliminate growth related defects. With a carbon coating of about 2 mu m, created by cracking spectroscopic-grade acetone at similar to 900 degrees C, we observed very few grain boundaries and grain-boundary networks. C1 [Egarievwe, Stephen U.] Alabama A&M Univ, Nucl Engn & Radiol Sci Ctr, Normal, AL 35762 USA. [Roy, Utpal N.; Hossain, Anwar; James, Ralph B.] Brookhaven Natl Lab, Dept Nonproliferat & Natl Secur, Upton, NY 11973 USA. RP Egarievwe, SU (reprint author), Alabama A&M Univ, Nucl Engn & Radiol Sci Ctr, Normal, AL 35762 USA. EM stephen.egarievwe@aamu.edu; nroy@bnl.gov; hossain@bnl.gov; rjames@bnl.gov FU U.S. Department of Homeland Security; Domestic Nuclear Detection Office, under competitively awarded contract/IAA [2012-DN077-AR1065-03]; U.S. Nuclear Regulatory Commission [NRC-2710-514]; BNL scientists received; U.S. Department of Energy Office of Defense Nuclear Nonproliferation RD FX Manuscript received December 31, 2014. This work has been supported by the U.S. Department of Homeland Security, Domestic Nuclear Detection Office, under competitively awarded contract/IAA award number 2012-DN077-AR1065-03. Alabama A&M University researchers were also supported by the U.S. Nuclear Regulatory Commission through award number NRC-2710-514, and BNL scientists received support from the U.S. Department of Energy Office of Defense Nuclear Nonproliferation R&D. These supports do not constitute an expressed or implied endorsement by the U.S. Government. 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 978-1-4799-6097-2 PY 2014 PG 4 WC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BG9AN UT WOS:000392917500536 ER PT J AU Egarievwe, SU Okwechime, IO Hossain, A Jow, JO Hales, ZM Egarievwe, AA Roy, UN James, RB AF Egarievwe, Stephen U. Okwechime, Ifechukwude O. Hossain, Anwar Jow, Julius O. Hales, Zaveon M. Egarievwe, Alexander A. Roy, Utpal N. James, Ralph B. GP IEEE TI Comparative Study on the Effects of Chemical Treatments on CdZnTe Nuclear Detectors SO 2014 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC) LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium / Medical Imaging Conference (NSS/MIC) CY NOV 08-15, 2014 CL Seattle, WA SP IEEE ID TELLURIDE RADIATION DETECTORS; PASSIVATION; PERFORMANCE AB Room temperature semiconductor detectors such as cadmium zinc telluride (CdZnTe) are often subject to surface damage during fabrication processes, thus affecting detector performance. The surface defects are usually removed through mechanical and chemical polishing, and passivation processes. This paper compares the effects of two surface passivation chemical solutions on CdZnTe detectors. The two chemicals studied are ammonium fluoride in hydrogen peroxide (NH4F + H2O2 + H2O) and potassium hydroxide in hydrogen peroxide (0.1 g of KOH + 10 ml of 30% H2O2) solutions. X-ray photoelectron spectroscopy analysis showed that the NH4F-based solution is more effective at converting Te species on the CZT wafer surfaces into a more stable TeO2 layer, with values of 4.90 and 5.34 for the Te(3)d(3/2)O(2)/Te3d(3/2) and Te(3)d(5/2)O(2)/Te(3)d(5/2) peak height ratios respectively, compared to the KOH-based solution which has 1.25 and 1.19 respectively. Analysis of the 59.5-keV peak of Am-241 showed that the sample passivated with the NH4F-based solution has a better energy resolution (FWHM = 9.83%) compared to the one passivated with the KOH-based solution (FWHM = 14.60%). C1 [Egarievwe, Stephen U.; Okwechime, Ifechukwude O.; Jow, Julius O.; Hales, Zaveon M.; Egarievwe, Alexander A.] Alabama A&M Univ, Nucl Engn & Radiol Sci Ctr, Normal, AL 35762 USA. [Hossain, Anwar; Roy, Utpal N.; James, Ralph B.] Brookhaven Natl Lab, Dept Nonproliferat & Natl Secur, Upton, NY 11973 USA. RP Egarievwe, SU (reprint author), Alabama A&M Univ, Nucl Engn & Radiol Sci Ctr, Normal, AL 35762 USA. EM stephen.egarievwe@aamu.edu; rjames@bnl.gov FU U.S. Department of Homeland Security; Domestic Nuclear Detection Office, under competitively awarded contract/IAA [2012-DN077-AR1065-03]; U.S. Nuclear Regulatory Commission [NRC-2710-514]; BNL scientists received; U.S. Department of Energy Office of Defense Nuclear Nonproliferation RD; U.S. Government FX Manuscript received December 30, 2014. This work has been supported by the U.S. Department of Homeland Security, Domestic Nuclear Detection Office, under competitively awarded contract/IAA award number 2012-DN077-AR1065-03. Alabama A&M University researchers were also supported by the U.S. Nuclear Regulatory Commission through award number NRC-2710-514, and BNL scientists received support from the U.S. Department of Energy Office of Defense Nuclear Nonproliferation R&D. These supports do not constitute an expressed or implied endorsement by the U.S. Government. NR 15 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-6097-2 PY 2014 PG 5 WC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BG9AN UT WOS:000392917500535 ER PT J AU Gerling, MD Goldsmith, JEM Brennan, JS AF Gerling, Mark D. Goldsmith, John E. M. Brennan, James S. GP IEEE TI MINER - A Mobile Imager of Neutrons for Emergency Responders SO 2014 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC) LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium / Medical Imaging Conference (NSS/MIC) CY NOV 08-15, 2014 CL Seattle, WA SP IEEE AB Our research group has been developing a fast neutron imaging platform to enhance the capabilities of emergency responders in the localization and characterization of special nuclear material. This mobile imager of neutrons for emergency responders (MINER) is a compact neutron scatter camera optimized to provide omni-directional (4-Pi) imaging with only a similar to twofold decrease in sensitivity compared to our much larger neutron scatter cameras. The system performance is tuned for fission energy neutron imaging and spectroscopy, and it also can function as a Compton camera for gamma imaging. Results will be presented relating to detector response as well as several measurement campaigns at external facilities. C1 [Gerling, Mark D.; Goldsmith, John E. M.; Brennan, James S.] Sandia Natl Labs, Livermore, CA 94550 USA. RP Gerling, MD (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. EM mgerlin@sandia.gov; jgold@sandia.gov NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 978-1-4799-6097-2 PY 2014 PG 4 WC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BG9AN UT WOS:000392917500370 ER PT J AU Goldan, AH Rowlands, JA Lu, M Zhao, W AF Goldan, Amir H. Rowlands, John A. Lu, Ming Zhao, Wei GP IEEE TI Nanopattern Multi-Well Avalanche Selenium Detector with Picosecond Time Resolution SO 2014 IEEE NUCLEAR SCIENCE SYMPOSIUM AND MEDICAL IMAGING CONFERENCE (NSS/MIC) LA English DT Proceedings Paper CT IEEE Nuclear Science Symposium / Medical Imaging Conference (NSS/MIC) CY NOV 08-15, 2014 CL Seattle, WA SP IEEE AB For the first time, we propose using amorphous selenium (a-Se) as the photoconductive material for time-of flight (TOF) detectors. The major drawback of a-Se is its poor time-resolution and low mobility due to shallow-traps, problems that must be circumvented for TOF applications. Thus, we propose a nanopattern multi-well a-Se detector to enable the utilization of both avalanche multiplication gain and unipolar time-differential (UTD) charge sensing in one device. Advantages of avalanche-mode a-Se are having photoconductive gain and band transport in extended states with the highest possible mobility and negligible trapping. Most importantly, UTD charge sensing enables operating the detector at its theoretical limit of charge diffusion. Our simulation results show that UTD charge sensing in avalanche-mode a-Se improves time-resolution by more than 3 orders-of-magnitude and proves very promising to achieve for the first time the ultimate goal of 10 ps time-resolution with a material that is low-cost and uniformly scalable to large-area. C1 [Goldan, Amir H.; Zhao, Wei] Stony Brook Med, Radiol, Stony Brook, NY 11794 USA. [Rowlands, John A.] Thunder Bay Reg Res Inst, Thunder Bay, ON P7B 5E1, Canada. [Lu, Ming] Brookhaven Natl Lab, Ctr Funct Nanomat, Upton, NY 11973 USA. RP Goldan, AH (reprint author), Stony Brook Med, Radiol, Stony Brook, NY 11794 USA. EM amirhossein.goldan@stonybrookmedicine.edu FU NEI [1 R01 CA148053, 1 R01 EB002655]; U.S. Department of Energy (DOE) Office of Basic Energy Sciences (BES); Materials Science and Engineering Division (C.L., S.J.P); ORNLs Center for Nanophase Materials Sciences (CNMS); DOE-BES; U.S. Department of Energy; Office of Basic Energy Sciences [DE-ACO2-98CH10886] FX This research was supported by NEI (1 R01 CA148053 and 1 R01 EB002655), the U.S. Department of Energy (DOE) Office of Basic Energy Sciences (BES), Materials Science and Engineering Division (C.L., S.J.P), and through a user project supported by ORNLs Center for Nanophase Materials Sciences (CNMS), which is also sponsored by DOE-BES. This research was in collaboration with Center for Functional Nanomaterials, Brookhaven National Laboratory, which is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. DE-ACO2-98CH10886.. 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 BN 978-1-4799-6097-2 PY 2014 PG 3 WC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA BG9AN UT WOS:000392917500471 ER EF