WorldWideScience

Sample records for amorphous metals high-performance

  1. Iron-Based Amorphous Metals:The High Performance Corrosion Resistant Materials(HPCRM) Program

    International Nuclear Information System (INIS)

    An overview of the High-Performance Corrosion-Resistant Materials (HPCRM) Program, which was co-sponsored by the Defense Advanced Research Projects Agency (DARPA) Defense Sciences Office (DSO) and the United States Department of Energy (DOE) Office of Civilian and Radioactive Waste Management (OCRWM), is discussed. Programmatic investigations have included a broad range of topics: alloy design and composition; materials synthesis; thermal stability; corrosion resistance; environmental cracking; mechanical properties; damage tolerance; radiation effects; and important potential applications. Amorphous alloys identified as SAM2X5 (Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4) and SAM1651 (Fe48Mo14Cr15Y2C15B6) have been produced as melt-spun ribbons, drop-cast ingots and thermal-spray coatings. Chromium (Cr), molybdenum (Mo) and tungsten (W) additions provided corrosion resistance, while boron (B) enabled glass formation. Earlier electrochemical studies of melt-spun ribbons and ingots of these amorphous alloys demonstrated outstanding passive film stability. More recently thermal-spray coatings of these amorphous alloys have been made and subjected to long-term salt-fog and immersion tests. Good corrosion resistance has been observed during salt-fog testing. Corrosion rates were measured in situ with linear polarization, while simultaneously monitoring the open-circuit corrosion potentials. Reasonably good performance was observed. The sensitivity of these measurements to electrolyte composition and temperature was determined. The high boron content of this particular amorphous metal makes this amorphous alloy an effective neutron absorber, and suitable for criticality control applications. In general, the corrosion resistance of such iron-based amorphous metals is maintained at operating temperatures up to the glass transition temperature. These materials are much harder than conventional stainless steel and nickel-based materials, and are proving to have excellent wear

  2. Iron-Based Amorphous Metals:The High Performance Corrosion Resistant Materials(HPCRM) Program

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J

    2007-07-09

    An overview of the High-Performance Corrosion-Resistant Materials (HPCRM) Program, which was co-sponsored by the Defense Advanced Research Projects Agency (DARPA) Defense Sciences Office (DSO) and the United States Department of Energy (DOE) Office of Civilian and Radioactive Waste Management (OCRWM), is discussed. Programmatic investigations have included a broad range of topics: alloy design and composition; materials synthesis; thermal stability; corrosion resistance; environmental cracking; mechanical properties; damage tolerance; radiation effects; and important potential applications. Amorphous alloys identified as SAM2X5 (Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4}) and SAM1651 (Fe{sub 48}Mo{sub 14}Cr{sub 15}Y{sub 2}C{sub 15}B{sub 6}) have been produced as melt-spun ribbons, drop-cast ingots and thermal-spray coatings. Chromium (Cr), molybdenum (Mo) and tungsten (W) additions provided corrosion resistance, while boron (B) enabled glass formation. Earlier electrochemical studies of melt-spun ribbons and ingots of these amorphous alloys demonstrated outstanding passive film stability. More recently thermal-spray coatings of these amorphous alloys have been made and subjected to long-term salt-fog and immersion tests. Good corrosion resistance has been observed during salt-fog testing. Corrosion rates were measured in situ with linear polarization, while simultaneously monitoring the open-circuit corrosion potentials. Reasonably good performance was observed. The sensitivity of these measurements to electrolyte composition and temperature was determined. The high boron content of this particular amorphous metal makes this amorphous alloy an effective neutron absorber, and suitable for criticality control applications. In general, the corrosion resistance of such iron-based amorphous metals is maintained at operating temperatures up to the glass transition temperature. These materials are much harder than conventional

  3. Iron-Based Amorphous-Metals: High-Performance Corrosion-Resistant Material (HPCRM) Development

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J C; Choi, J S; Saw, C; Haslam, J; Day, D; Hailey, P; Lian, T; Rebak, R; Perepezko, J; Payer, J; Branagan, D; Beardsley, B; D' Amato, A; Aprigliano, L

    2008-01-09

    An overview of the High-Performance Corrosion-Resistant Materials (HPCRM) Program, which was co-sponsored by the Defense Advanced Research Projects Agency (DARPA) Defense Sciences Office (DSO) and the United States Department of Energy (DOE) Office of Civilian and Radioactive Waste Management (OCRWM), is discussed. Programmatic investigations have included a broad range of topics: alloy design and composition; materials synthesis; thermal stability; corrosion resistance; environmental cracking; mechanical properties; damage tolerance; radiation effects; and important potential applications. Amorphous alloys identified as SAM2X5 (Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4}) and SAM1651 (Fe{sub 48}Mo{sub 14}Cr{sub 15}Y{sub 2}C{sub 15}B{sub 6}) have been produced as melt-spun ribbons, drop-cast ingots and thermal-spray coatings. Chromium (Cr), molybdenum (Mo) and tungsten (W) additions provided corrosion resistance, while boron (B) enabled glass formation. Earlier electrochemical studies of melt-spun ribbons and ingots of these amorphous alloys demonstrated outstanding passive film stability. More recently thermal-spray coatings of these amorphous alloys have been made and subjected to long-term salt-fog and immersion tests. Good corrosion resistance has been observed during salt-fog testing. Corrosion rates were measured in situ with linear polarization, while simultaneously monitoring the open-circuit corrosion potentials. Reasonably good performance was observed. The sensitivity of these measurements to electrolyte composition and temperature was determined. The high boron content of this particular amorphous metal makes this amorphous alloy an effective neutron absorber, and suitable for criticality control applications. In general, the corrosion resistance of such iron-based amorphous metals is maintained at operating temperatures up to the glass transition temperature. These materials are much harder than conventional

  4. Iron-Based Amorphous Metals: High-Performance Corrosion-Resistant Material Development

    Science.gov (United States)

    Farmer, Joseph; Choi, Jor-Shan; Saw, Cheng; Haslam, Jeffrey; Day, Dan; Hailey, Phillip; Lian, Tiangan; Rebak, Raul; Perepezko, John; Payer, Joe; Branagan, Daniel; Beardsley, Brad; D'Amato, Andy; Aprigliano, Lou

    2009-06-01

    An overview of the High-Performance Corrosion-Resistant Materials (HPCRM) Program, which was cosponsored by the Defense Advanced Research Projects Agency (DARPA) Defense Sciences Office (DSO) and the U.S. Department of Energy (DOE) Office of Civilian and Radioactive Waste Management (OCRWM), is discussed. Programmatic investigations have included a broad range of topics: alloy design and composition, materials synthesis, thermal stability, corrosion resistance, environmental cracking, mechanical properties, damage tolerance, radiation effects, and important potential applications. Amorphous alloys identified as SAM2X5 (Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4) and SAM1651 (Fe48Mo14Cr15Y2C15B6) have been produced as meltspun ribbons (MSRs), dropcast ingots, and thermal-spray coatings. Chromium (Cr), molybdenum (Mo), and tungsten (W) additions provided corrosion resistance, while boron (B) enabled glass formation. Earlier electrochemical studies of MSRs and ingots of these amorphous alloys demonstrated outstanding passive film stability. More recently, thermal-spray coatings of these amorphous alloys have been made and subjected to long-term salt-fog and immersion tests; good corrosion resistance has been observed during salt-fog testing. Corrosion rates were measured in situ with linear polarization, while the open-circuit corrosion potentials (OCPs) were simultaneously monitored; reasonably good performance was observed. The sensitivity of these measurements to electrolyte composition and temperature was determined. The high boron content of this particular amorphous metal makes this amorphous alloy an effective neutron absorber and suitable for criticality-control applications. In general, the corrosion resistance of such iron-based amorphous metals is maintained at operating temperatures up to the glass transition temperature. These materials are much harder than conventional stainless steel and Ni-based materials, and are proving to have excellent wear

  5. Iron-Based Amorphous-Metals: High-Performance Corrosion-Resistant Materials (HPCRM) Development Final Report

    International Nuclear Information System (INIS)

    An overview of the High-Performance Corrosion-Resistant Materials (HPCRM) Program, which was co-sponsored by the Defense Advanced Research Projects Agency (DARPA) Defense Sciences Office (DSO) and the United States Department of Energy (DOE) Office of Civilian and Radioactive Waste Management (OCRWM), is discussed. Programmatic investigations have included a broad range of topics: alloy design and composition; materials synthesis; thermal stability; corrosion resistance; environmental cracking; mechanical properties; damage tolerance; radiation effects; and important potential applications. Amorphous alloys identified as SAM2X5 (Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4) and SAM1651 (Fe48Mo14Cr15Y2C15B6) have been produced as melt-spun ribbons, drop-cast ingots and thermal-spray coatings. Chromium (Cr), molybdenum (Mo) and tungsten (W) additions provided corrosion resistance, while boron (B) enabled glass formation. Earlier electrochemical studies of melt-spun ribbons and ingots of these amorphous alloys demonstrated outstanding passive film stability. More recently thermal-spray coatings of these amorphous alloys have been made and subjected to long-term salt-fog and immersion tests. Good corrosion resistance has been observed during salt-fog testing. Corrosion rates were measured in situ with linear polarization, while simultaneously monitoring the open-circuit corrosion potentials. Reasonably good performance was observed. The sensitivity of these measurements to electrolyte composition and temperature was determined. The high boron content of this particular amorphous metal make this amorphous alloy an effective neutron absorber, and suitable for criticality control applications. In general, the corrosion resistance of these iron-based amorphous metals is maintained at operating temperatures up to the glass transition temperature. These materials are much harder than conventional stainless steel and nickel-based materials, and are proving to have excellent wear

  6. Iron-Based Amorphous-Metals: High-Performance Corrosion-Resistant Materials (HPCRM) Development Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J C; Choi, J; Saw, C; Haslem, J; Day, D; Hailey, P; Lian, T; Rebak, R; Perepezko, J; Payer, J; Branagan, D; Beardsley, B; D' Amato, A; Aprigliano, L

    2009-03-16

    An overview of the High-Performance Corrosion-Resistant Materials (HPCRM) Program, which was co-sponsored by the Defense Advanced Research Projects Agency (DARPA) Defense Sciences Office (DSO) and the United States Department of Energy (DOE) Office of Civilian and Radioactive Waste Management (OCRWM), is discussed. Programmatic investigations have included a broad range of topics: alloy design and composition; materials synthesis; thermal stability; corrosion resistance; environmental cracking; mechanical properties; damage tolerance; radiation effects; and important potential applications. Amorphous alloys identified as SAM2X5 (Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4}) and SAM1651 (Fe{sub 48}Mo{sub 14}Cr{sub 15}Y{sub 2}C{sub 15}B{sub 6}) have been produced as melt-spun ribbons, drop-cast ingots and thermal-spray coatings. Chromium (Cr), molybdenum (Mo) and tungsten (W) additions provided corrosion resistance, while boron (B) enabled glass formation. Earlier electrochemical studies of melt-spun ribbons and ingots of these amorphous alloys demonstrated outstanding passive film stability. More recently thermal-spray coatings of these amorphous alloys have been made and subjected to long-term salt-fog and immersion tests. Good corrosion resistance has been observed during salt-fog testing. Corrosion rates were measured in situ with linear polarization, while simultaneously monitoring the open-circuit corrosion potentials. Reasonably good performance was observed. The sensitivity of these measurements to electrolyte composition and temperature was determined. The high boron content of this particular amorphous metal make this amorphous alloy an effective neutron absorber, and suitable for criticality control applications. In general, the corrosion resistance of these iron-based amorphous metals is maintained at operating temperatures up to the glass transition temperature. These materials are much harder than conventional

  7. FY05 HPCRM Annual Report: High-Performance Corrosion-Resistant Iron-Based Amorphous Metal Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J; Choi, J; Haslam, J; Day, S; Yang, N; Headley, T; Lucadamo, G; Yio, J; Chames, J; Gardea, A; Clift, M; Blue, G; Peters, W; Rivard, J; Harper, D; Swank, D; Bayles, R; Lemieux, E; Brown, R; Wolejsza, T; Aprigliano, L; Branagan, D; Marshall, M; Meacham, B; Aprigliano, L; Branagan, D; Marshall, M; Meacham, B; Lavernia, E; Schoenung, J; Ajdelsztajn, L; Dannenberg, J; Graeve, O; Lewandowski, J; Perepezko, J; Hildal, K; Kaufman, L; Boudreau, J

    2007-09-20

    New corrosion-resistant, iron-based amorphous metals have been identified from published data or developed through combinatorial synthesis, and tested to determine their relative corrosion resistance. Many of these materials can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS No. N06022) in some very aggressive environments, including concentrated calcium-chloride brines at elevated temperature. Two Fe-based amorphous metal formulations have been found that appear to have corrosion resistance comparable to, or better than that of Ni-based Alloy C-22, based on breakdown potential and corrosion rate. Both Cr and Mo provide corrosion resistance, B enables glass formation, and Y lowers critical cooling rate (CCR). SAM1651 has yttrium added, and has a nominal critical cooling rate of only 80 Kelvin per second, while SAM2X7 (similar to SAM2X5) has no yttrium, and a relatively high critical cooling rate of 610 Kelvin per second. Both amorphous metal formulations have strengths and weaknesses. SAM1651 (yttrium added) has a low critical cooling rate (CCR), which enables it to be rendered as a completely amorphous thermal spray coating. Unfortunately, it is relatively difficult to atomize, with powders being irregular in shape. This causes the powder to be difficult to pneumatically convey during thermal spray deposition. Gas atomized SAM1651 powder has required cryogenic milling to eliminate irregularities that make flow difficult. SAM2X5 (no yttrium) has a high critical cooling rate, which has caused problems associated with devitrification. SAM2X5 can be gas atomized to produce spherical powders of SAM2X5, which enable more facile thermal spray deposition. The reference material, nickel-based Alloy C-22, is an outstanding corrosion-resistant engineering material. Even so, crevice corrosion has been observed with C-22 in hot sodium chloride environments without buffer

  8. Physics of amorphous metals

    CERN Document Server

    Kovalenko, Nikolai P; Krey, Uwe

    2008-01-01

    The discovery of bulk metallic glasses has led to a large increase in the industrial importance of amorphous metals, and this is expected to continue. This book is the first to describe the theoretical physics of amorphous metals, including the important theoretical development of the last 20 years.The renowned authors stress the universal aspects in their description of the phonon or magnon low-energy excitations in the amorphous metals, e.g. concerning the remarkable consequences of the properties of these excitations for the thermodynamics at low and intermediate temperatures. Tunneling

  9. High-Performance Corrosion-Resistant Materials: Iron-Based Amorphous-Metal Thermal-Spray Coatings: SAM HPCRM Program ? FY04 Annual Report ? Rev. 0 - DARPA DSO & DOE OCRWM Co-Sponsored Advanced Materials Program

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J; Haslam, J; Wong, F; Ji, S; Day, S; Branagan, D; Marshall, M; Meacham, B; Buffa, E; Blue, C; Rivard, J; Beardsley, M; Buffa, E; Blue, C; Rivard, J; Beardsley, M; Weaver, D; Aprigliano, L; Kohler, L; Bayles, R; Lemieux, E; Wolejsza, T; Martin, F; Yang, N; Lucadamo, G; Perepezko, J; Hildal, K; Kaufman, L; Heuer, A; Ernst, F; Michal, G; Kahn, H; Lavernia, E

    2007-09-19

    The multi-institutional High Performance Corrosion Resistant Materials (HPCRM) Team is cosponsored by the Defense Advanced Projects Agency (DARPA) Defense Science Office (DSO) and the Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM), and has developed new corrosion-resistant, iron-based amorphous metals that can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS No. N06022) in very aggressive environments, including concentrated calcium-chloride brines at elevated temperature. Corrosion costs the Department of Defense billions of dollars every year, with an immense quantity of material in various structures undergoing corrosion. For example, in addition to fluid and seawater piping, ballast tanks, and propulsions systems, approximately 345 million square feet of structure aboard naval ships and crafts require costly corrosion control measures. The use of advanced corrosion-resistant materials to prevent the continuous degradation of this massive surface area would be extremely beneficial. The Fe-based corrosion-resistant, amorphous-metal coatings under development may prove of importance for applications on ships. Such coatings could be used as an 'integral drip shield' on spent fuel containers, as well as protective coatings that could be applied over welds, thereby preventing exposure to environments that might cause stress corrosion cracking. In the future, such new high-performance iron-based materials could be substituted for more-expensive nickel-based alloys, thereby enabling a reduction in the $58-billion life cycle cost for the long-term storage of the Nation's spent nuclear fuel by tens of percent.

  10. High-Performance Corrosion-Resistant Materials: Iron-Based Amorphous-Metal Thermal-Spray Coatings: SAM HPCRM Program ? FY04 Annual Report ? Rev. 0 - DARPA DSO and DOE OCRWM Co-Sponsored Advanced Materials Program

    International Nuclear Information System (INIS)

    The multi-institutional High Performance Corrosion Resistant Materials (HPCRM) Team is cosponsored by the Defense Advanced Projects Agency (DARPA) Defense Science Office (DSO) and the Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM), and has developed new corrosion-resistant, iron-based amorphous metals that can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS No. N06022) in very aggressive environments, including concentrated calcium-chloride brines at elevated temperature. Corrosion costs the Department of Defense billions of dollars every year, with an immense quantity of material in various structures undergoing corrosion. For example, in addition to fluid and seawater piping, ballast tanks, and propulsions systems, approximately 345 million square feet of structure aboard naval ships and crafts require costly corrosion control measures. The use of advanced corrosion-resistant materials to prevent the continuous degradation of this massive surface area would be extremely beneficial. The Fe-based corrosion-resistant, amorphous-metal coatings under development may prove of importance for applications on ships. Such coatings could be used as an 'integral drip shield' on spent fuel containers, as well as protective coatings that could be applied over welds, thereby preventing exposure to environments that might cause stress corrosion cracking. In the future, such new high-performance iron-based materials could be substituted for more-expensive nickel-based alloys, thereby enabling a reduction in the $58-billion life cycle cost for the long-term storage of the Nation's spent nuclear fuel by tens of percent

  11. Amorphous metal based nanoelectromechanical switch

    KAUST Repository

    Mayet, Abdulilah M.

    2013-04-01

    Nanoelectromechanical (NEM) switch is an interesting ultra-low power option which can operate in the harsh environment and can be a complementary element in complex digital circuitry. Although significant advancement is happening in this field, report on ultra-low voltage (pull-in) switch which offers high switching speed and area efficiency is yet to be made. One key challenge to achieve such characteristics is to fabricate nano-scale switches with amorphous metal so the shape and dimensional integrity are maintained to achieve the desired performance. Therefore, we report a tungsten alloy based amorphous metal with fabrication process development of laterally actuated dual gated NEM switches with 100 nm width and 200 nm air-gap to result in <5 volts of actuation voltage (Vpull-in). © 2013 IEEE.

  12. Uncooled amorphous silicon IRFPA for high performance and high volume applications

    Science.gov (United States)

    Pochic, D.; Durand, A.; Tissot, J. L.; Crastes, A.; Vilain, M.; Legras, O.; Tinnes, S.; Minassian, C.; Robert, P.

    2009-09-01

    For more than 10 years now, uncooled sensors have given new opportunities in the IR field of applications by being able to be produce in large volume. Compared to cooled technology, uncooled detectors offer many interesting advantages: high reliability, lower cost ... whereas the performance is high enough for a lot of applications. Thermography, building inspection, enhanced driver vision and military (thermal weapon sight, low altitude UAV sensor) are applications which can be provided with affordable IR focal plane arrays... As uncooled IR sensors are mainly dedicated to these high volume applications, any uncooled IRFPA technology has to be able to provide high performance sensors but also to be producible in large volume at a minimum cost. The high level of accumulated expertise by ULIS and CEA/LETI on uncooled microbolometers made from amorphous silicon layer enables ULIS to develop a full range of IRFPA formats from 160x120 to 1024x768 pixels with 25μm and 17μm pixel-pitch, designed for high end and high volume applications. The detector ROIC designs rely on a simple architecture (detector configuration addressed by a serial link for user defined amplifier gain, windowing capability...) which enables easier systems upgrade and therefore a reduced system development non recurrent cost. The packaging technique depends on the application environment and the production volume in order to fit with the market expectation. Starting from metallic and ceramics package, very advanced new technique is under development in order to reduce uncooled IRFPA production cost. NETD in the range of 30mK (f/1, 300K, 60Hz) as well as operability higher than 99.99%, are routinely achieved with amorphous silicon technology.

  13. Amorphous metallic films in silicon metallization systems

    Science.gov (United States)

    So, F.; Kolawa, E.; Nicolet, M. A.

    1985-01-01

    Diffusion barrier research was focussed on lowering the chemical reactivity of amorphous thin films on silicon. An additional area of concern is the reaction with metal overlays such as aluminum, silver, and gold. Gold was included to allow for technology transfer to gallium arsenide PV cells. Amorphous tungsten nitride films have shown much promise. Stability to annealing temperatures of 700, 800, and 550 C were achieved for overlays of silver, gold, and aluminum, respectively. The lower results for aluminum were not surprising because there is an eutectic that can form at a lower temperature. It seems that titanium and zirconium will remove the nitrogen from a tungsten nitride amorphous film and render it unstable. Other variables of research interest were substrate bias and base pressure during sputtering.

  14. FY05 HPCRM Annual Report: High-Performance Corrosion-Resistant Iron-Based Amorphous Metal Coatings Evaluation of Corrosion Resistance FY05 HPCRM Annual Report No. Rev. 1DOE-DARPA Co-Sponsored Advanced Materials Program

    International Nuclear Information System (INIS)

    New corrosion-resistant, iron-based amorphous metals have been identified from published data or developed through combinatorial synthesis, and tested to determine their relative corrosion resistance. Many of these materials can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS No. N06022) in some very aggressive environments, including concentrated calcium-chloride brines at elevated temperature. Two Fe-based amorphous metal formulations have been found that appear to have corrosion resistance comparable to, or better than that of Ni-based Alloy C-22, based on breakdown potential and corrosion rate. Both Cr and Mo provide corrosion resistance, B enables glass formation, and Y lowers critical cooling rate (CCR). SAM1651 has yttrium added, and has a nominal critical cooling rate of only 80 Kelvin per second, while SAM2X7 (similar to SAM2X5) has no yttrium, and a relatively high critical cooling rate of 610 Kelvin per second. Both amorphous metal formulations have strengths and weaknesses. SAM1651 (yttrium added) has a low critical cooling rate (CCR), which enables it to be rendered as a completely amorphous thermal spray coating. Unfortunately, it is relatively difficult to atomize, with powders being irregular in shape. This causes the powder to be difficult to pneumatically convey during thermal spray deposition. Gas atomized SAM1651 powder has required cryogenic milling to eliminate irregularities that make flow difficult. SAM2X5 (no yttrium) has a high critical cooling rate, which has caused problems associated with devitrification. SAM2X5 can be gas atomized to produce spherical powders of SAM2X5, which enable more facile thermal spray deposition. The reference material, nickel-based Alloy C-22, is an outstanding corrosion-resistant engineering material. Even so, crevice corrosion has been observed with C-22 in hot sodium chloride environments without buffer

  15. FY05 HPCRM Annual Report: High-Performance Corrosion-Resistant Iron-Based Amorphous Metal Coatings Evaluation of Corrosion Reistance FY05 HPCRM Annual Report # Rev. 1DOE-DARPA Co-Sponsored Advanced Materials Program

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J C; Haslam, J J; Day, S D

    2007-09-19

    New corrosion-resistant, iron-based amorphous metals have been identified from published data or developed through combinatorial synthesis, and tested to determine their relative corrosion resistance. Many of these materials can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS No. N06022) in some very aggressive environments, including concentrated calcium-chloride brines at elevated temperature. Two Fe-based amorphous metal formulations have been found that appear to have corrosion resistance comparable to, or better than that of Ni-based Alloy C-22, based on breakdown potential and corrosion rate. Both Cr and Mo provide corrosion resistance, B enables glass formation, and Y lowers critical cooling rate (CCR). SAM1651 has yttrium added, and has a nominal critical cooling rate of only 80 Kelvin per second, while SAM2X7 (similar to SAM2X5) has no yttrium, and a relatively high critical cooling rate of 610 Kelvin per second. Both amorphous metal formulations have strengths and weaknesses. SAM1651 (yttrium added) has a low critical cooling rate (CCR), which enables it to be rendered as a completely amorphous thermal spray coating. Unfortunately, it is relatively difficult to atomize, with powders being irregular in shape. This causes the powder to be difficult to pneumatically convey during thermal spray deposition. Gas atomized SAM1651 powder has required cryogenic milling to eliminate irregularities that make flow difficult. SAM2X5 (no yttrium) has a high critical cooling rate, which has caused problems associated with devitrification. SAM2X5 can be gas atomized to produce spherical powders of SAM2X5, which enable more facile thermal spray deposition. The reference material, nickel-based Alloy C-22, is an outstanding corrosion-resistant engineering material. Even so, crevice corrosion has been observed with C-22 in hot sodium chloride environments without buffer

  16. Corrosion resistant amorphous metals and methods of forming corrosion resistant amorphous metals

    Science.gov (United States)

    Farmer, Joseph C.; Wong, Frank M.G.; Haslam, Jeffery J.; Yang, Nancy; Lavernia, Enrique J.; Blue, Craig A.; Graeve, Olivia A.; Bayles, Robert; Perepezko, John H.; Kaufman, Larry; Schoenung, Julie; Ajdelsztajn, Leo

    2014-07-15

    A system for coating a surface comprises providing a source of amorphous metal, providing ceramic particles, and applying the amorphous metal and the ceramic particles to the surface by a spray. The coating comprises a composite material made of amorphous metal that contains one or more of the following elements in the specified range of composition: yttrium (.gtoreq.1 atomic %), chromium (14 to 18 atomic %), molybdenum (.gtoreq.7 atomic %), tungsten (.gtoreq.1 atomic %), boron (.ltoreq.5 atomic %), or carbon (.gtoreq.4 atomic %).

  17. LOCAL ATOMIC STRUCTURE OF AMORPHOUS METALS

    OpenAIRE

    Egami, T.; Maed, K.; Srolovitz, D.; Vitek, V.

    1980-01-01

    The local parameters are introduced to describe the local atomic structure of amorphous metals. They define the structural defects which facilitate the explanation of various properties, including the volume change by annealing.

  18. Powder metallurgical high performance materials. Proceedings. Volume 1: high performance P/M metals

    International Nuclear Information System (INIS)

    The proceedings of this sequence of seminars form an impressive chronicle of the continued progress in the understanding of refractory metals and cemented carbides and in their manufacture and application. There the ingenuity and assiduous work of thousands of scientists and engineers striving for progress in the field of powder metallurgy is documented in more than 2000 contributions covering some 30000 pages. The 15th Plansee Seminar was convened under the general theme 'Powder Metallurgical High Performance Materials'. Under this broadened perspective the seminar will strive to look beyond the refractory metals and cemented carbides, which remain at its focus, to novel classes of materials, such as intermetallic compounds, with potential for high temperature applications. (author)

  19. High performance supercapacitors using metal oxide anchored graphene nanosheet electrodes

    KAUST Repository

    Baby, Rakhi Raghavan

    2011-01-01

    Metal oxide nanoparticles were chemically anchored onto graphene nanosheets (GNs) and the resultant composites - SnO2/GNs, MnO2/GNs and RuO2/GNs (58% of GNs loading) - coated over conductive carbon fabric substrates were successfully used as supercapacitor electrodes. The results showed that the incorporation of metal oxide nanoparticles improved the capacitive performance of GNs due to a combination of the effect of spacers and redox reactions. The specific capacitance values (with respect to the composite mass) obtained for SnO2/GNs (195 F g-1) and RuO 2/GNs (365 F g-1) composites at a scan rate of 20 mV s-1 in the present study are the best ones reported to date for a two electrode configuration. The resultant supercapacitors also exhibited high values for maximum energy (27.6, 33.1 and 50.6 W h kg-1) and power densities (15.9, 20.4 and 31.2 kW kg-1) for SnO2/GNs, MnO2/GNs and RuO2/GNs respectively. These findings demonstrate the importance and great potential of metal oxide/GNs based composite coated carbon fabric in the development of high-performance energy-storage systems. © 2011 The Royal Society of Chemistry.

  20. Controllable film densification and interface flatness for high-performance amorphous indium oxide based thin film transistors

    Energy Technology Data Exchange (ETDEWEB)

    Ou-Yang, Wei, E-mail: OUYANG.Wei@nims.go.jp, E-mail: TSUKAGOSHI.Kazuhito@nims.go.jp; Mitoma, Nobuhiko; Kizu, Takio; Gao, Xu; Lin, Meng-Fang; Tsukagoshi, Kazuhito, E-mail: OUYANG.Wei@nims.go.jp, E-mail: TSUKAGOSHI.Kazuhito@nims.go.jp [International Center for Materials Nanoarchitectronics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Nabatame, Toshihide [MANA Foundry and MANA Advanced Device Materials Group, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

    2014-10-20

    To avoid the problem of air sensitive and wet-etched Zn and/or Ga contained amorphous oxide transistors, we propose an alternative amorphous semiconductor of indium silicon tungsten oxide as the channel material for thin film transistors. In this study, we employ the material to reveal the relation between the active thin film and the transistor performance with aid of x-ray reflectivity study. By adjusting the pre-annealing temperature, we find that the film densification and interface flatness between the film and gate insulator are crucial for achieving controllable high-performance transistors. The material and findings in the study are believed helpful for realizing controllable high-performance stable transistors.

  1. Atomic-Scale Imprinting into Amorphous Metals

    Science.gov (United States)

    Schwarz, Udo; Li, Rui; Simon, Georg; Kinser, Emely; Liu, Ze; Chen, Zheng; Zhou, Chao; Singer, Jonathan; Osuji, Chinedum; Schroers, Jan

    Nanoimprinting by thermoplastic forming (TPF) has attracted significant attention in recent years due to its promise of low-cost fabrication of nanostructured devices. Usually performed using polymers, amorphous metals have been identified as a material class that might be even better suited for nanoimprinting due to a combination of mechanical properties and processing ability. Commonly referred to as metallic glasses, their featureless atomic structure suggests that there may not be an intrinsic size limit to the material's ability to replicate a mold. To study this hypothesis, we demonstrate atomic-scale imprinting into amorphous metals by TPF under ambient conditions. Atomic step edges of a SrTiO3 (STO) single crystal used as mold were successfully imprinted into Pt-based bulk metallic glasses (BMGs) with high fidelity. Terraces on the BMG replicas possess atomic smoothness with sub-Angstrom roughness that is identical to the one measured on the STO mold. Systematic studies revealed that the quality of the replica depends on the loading rate during imprinting, that the same mold can be used multiple times without degradation of mold or replicas, and that the atomic-scale features on as-imprinted BMG surfaces has impressive long-term stability (months).

  2. Core-shell amorphous silicon-carbon nanoparticles for high performance anodes in lithium ion batteries

    Science.gov (United States)

    Sourice, Julien; Bordes, Arnaud; Boulineau, Adrien; Alper, John P.; Franger, Sylvain; Quinsac, Axelle; Habert, Aurélie; Leconte, Yann; De Vito, Eric; Porcher, Willy; Reynaud, Cécile; Herlin-Boime, Nathalie; Haon, Cédric

    2016-10-01

    Core-shell silicon-carbon nanoparticles are attractive candidates as active material to increase the capacity of Li-ion batteries while mitigating the detrimental effects of volume expansion upon lithiation. However crystalline silicon suffers from amorphization upon the first charge/discharge cycle and improved stability is expected in starting with amorphous silicon. Here we report the synthesis, in a single-step process, of amorphous silicon nanoparticles coated with a carbon shell (a-Si@C), via a two-stage laser pyrolysis where decomposition of silane and ethylene are conducted in two successive reaction zones. Control of experimental conditions mitigates silicon core crystallization as well as formation of silicon carbide. Auger electron spectroscopy and scanning transmission electron microscopy show a carbon shell about 1 nm in thickness, which prevents detrimental oxidation of the a-Si cores. Cyclic voltammetry demonstrates that the core-shell composite reaches its maximal lithiation during the first sweep, thanks to its amorphous core. After 500 charge/discharge cycles, it retains a capacity of 1250 mAh.g-1 at a C/5 rate and 800 mAh.g-1 at 2C, with an outstanding coulombic efficiency of 99.95%. Moreover, post-mortem observations show an electrode volume expansion of less than 20% and preservation of the nanostructuration.

  3. Large Size High Performance Transparent Amorphous Silicon Sensors for Laser Beam Position Detection and Monitoring

    International Nuclear Information System (INIS)

    We present the measured performance of a new generation of semitransparente amorphous silicon position detectors. They have a large sensitive area (30 x 30 mm2) and show good properties such as a high response (about 20 mA/W), an intinsic position resolution better than 3 m, a spatial point reconstruction precision better than 10 m, deflection angles smaller than 10 rad and a transmission power in the visible and NIR higher than 70%. In addition, multipoint alignment monitoring, using up to five sensors lined along a light path of about 5 meters, can be achieved with a resolution better than 20m. (Author)

  4. Large-size high-performance transparent amorphous silicon sensors for laser beam position detection

    Energy Technology Data Exchange (ETDEWEB)

    Calderon, A. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Martinez-Rivero, C. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Matorras, F. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Rodrigo, T. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Sobron, M. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Vila, I. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Virto, A.L. [Instituto de Fisica de Cantabria. CSIC-University of Cantabria, Santander (Spain); Alberdi, J. [CIEMAT, Madrid (Spain); Arce, P. [CIEMAT, Madrid (Spain); Barcala, J.M. [CIEMAT, Madrid (Spain); Calvo, E. [CIEMAT, Madrid (Spain); Ferrando, A. [CIEMAT, Madrid (Spain)]. E-mail: antonio.ferrando@ciemat.es; Josa, M.I. [CIEMAT, Madrid (Spain); Luque, J.M. [CIEMAT, Madrid (Spain); Molinero, A. [CIEMAT, Madrid (Spain); Navarrete, J. [CIEMAT, Madrid (Spain); Oller, J.C. [CIEMAT, Madrid (Spain); Yuste, C. [CIEMAT, Madrid (Spain); Koehler, C. [Steinbeis-Transferzentrum fuer Angewandte Photovoltaik und Duennschichttechnik, Stuttgart (Germany); Lutz, B. [Steinbeis-Transferzentrum fuer Angewandte Photovoltaik und Duennschichttechnik, Stuttgart (Germany); Schubert, M.B. [Steinbeis-Transferzentrum fuer Angewandte Photovoltaik und Duennschichttechnik, Stuttgart (Germany); Werner, J.H. [Steinbeis-Transferzentrum fuer Angewandte Photovoltaik und Duennschichttechnik, Stuttgart (Germany)

    2006-09-15

    We present the measured performance of a new generation of semitransparent amorphous silicon position detectors. They have a large sensitive area (30x30mm{sup 2}) and show good properties such as a high response (about 20mA/W), an intrinsic position resolution better than 3{mu}m, a spatial-point reconstruction precision better than 10{mu}m, deflection angles smaller than 10{mu}rad and a transmission power in the visible and NIR higher than 70%.

  5. Large Size High Performance Transparent Amorphous Silicon Sensors for Laser Beam Position Detection and Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Calderon, A.; Martinez Rivero, C.; Matorras, F.; Rodrigo, T.; Sobron, M.; Vila, I.; Virto; Alberdi, J.; Arce, P.; Barcala, J. M.; Calvo, E.; Ferrando, A.; Josa, M. I.; Luque, J. M.; Molinero, A.; Navarrete, J.; Oller, J. C.; Kohler, C.; Lutz, B.; Schubert, M. B.

    2006-09-04

    We present the measured performance of a new generation of semitransparente amorphous silicon position detectors. They have a large sensitive area (30 x 30 mm2) and show good properties such as a high response (about 20 mA/W), an intinsic position resolution better than 3 m, a spatial point reconstruction precision better than 10 m, deflection angles smaller than 10 rad and a transmission power in the visible and NIR higher than 70%. In addition, multipoint alignment monitoring, using up to five sensors lined along a light path of about 5 meters, can be achieved with a resolution better than 20m. (Author)

  6. Amorphous Fe2O3 nanoshells coated on carbonized bacterial cellulose nanofibers as a flexible anode for high-performance lithium ion batteries

    Science.gov (United States)

    Huang, Yang; Lin, Zixia; Zheng, Mingbo; Wang, Tianhe; Yang, Jiazhi; Yuan, Fanshu; Lu, Xiaoyu; Liu, Lin; Sun, Dongping

    2016-03-01

    A three-dimensional (3D) carbonaceous aerogel derived from biomass bacterial cellulose (BC) is introduced as a flexible framework for iron oxides in Li-ion batteries (LIBs). The 3D carbonized BC (CBC) with highly interconnected nanofibrous structure exhibits good electrical conductivity and mechanical stability. The amorphous Fe2O3 is tightly coated on the nanofibers of CBC through a simple in situ thermal decomposition method. The obtained amorphous Fe2O3 anode (denoted as A-Fe2O3@CBC) exhibits stable cycling performance and high rate capability when assembled into a half-cell, which is supposed to benefit from the well-dispersed Fe2O3 nanoshells and the hierarchical pores in A-Fe2O3@CBC composite. The rational design of the nanostructure could improve the transportation of electrons/ions and effectively alleviate volume changes of Fe2O3 during the electrochemical cycling. Meanwhile, the amorphous nature of the Fe2O3 in anode provides an enhanced capacitive-like lithium storage and flexible structure of the active materials, resulting in much higher specific capacity and longer cycle life when compared with its crystalline counterpart. This work provides a promising approach to design and construct the flexible metal oxide anode materials based on 3D carbonaceous aerogel for high-performance LIBs.

  7. High performance uncooled amorphous silicon VGA IRFPA with 17-µm pixel-pitch

    Science.gov (United States)

    Tissot, J. L.; Durand, A.; Garret, Th.; Minassian, C.; Robert, P.; Tinnes, S.; Vilain, M.

    2010-04-01

    The high level of accumulated expertise by ULIS and CEA/LETI on uncooled microbolometers made from amorphous silicon enables ULIS to develop VGA IRFPA formats with 17μm pixel-pitch to build up the currently available product catalog. This detector keeps all the innovations developed on the 25 μm pixel-pitch ROIC (detector configuration by serial link, low power consumption and wide electrical dynamic range). The specific appeal of this unit lies in the high spatial resolution it provides. The reduction of the pixel-pitch turns this TEC-less VGA array into a product well adapted for high resolution and compact systems. In the last part of the paper, we will look more closely at the high electro-optical performances of this IRFPA and the rapid performance enhancement. We will insist on NETD trade-off with wide thermal dynamic range, as well as the high characteristics uniformity, achieved thanks to the mastering of the amorphous silicon technology coupled with the ROIC design. This technology node paves the way to high end products as well as low end compact smaller formats like 160 x 120 or smaller.

  8. Amorphous Zinc Oxide Integrated Wavy Channel Thin Film Transistor Based High Performance Digital Circuits

    KAUST Repository

    Hanna, Amir

    2015-12-04

    High performance thin film transistor (TFT) can be a great driving force for display, sensor/actuator, integrated electronics, and distributed computation for Internet of Everything applications. While semiconducting oxides like zinc oxide (ZnO) present promising opportunity in that regard, still wide area of improvement exists to increase the performance further. Here, we show a wavy channel (WC) architecture for ZnO integrated TFT which increases transistor width without chip area penalty, enabling high performance in material agnostic way. We further demonstrate digital logic NAND circuit using the WC architecture and compare it to the conventional planar architecture. The WC architecture circuits have shown 2× higher peak-to-peak output voltage for the same input voltage. They also have 3× lower high-to-low propagation delay times, respectively, when compared to the planar architecture. The performance enhancement is attributed to both extra device width and enhanced field effect mobility due to higher gate field electrostatics control.

  9. Ceramic Replaces Metal In High Performance Optomechanical Structures

    Science.gov (United States)

    Vasquez, Peter; Fox, Robert L.; Sandford, Stephen P.

    1995-01-01

    Recently developed ceramic materials and fabrication techniques integrated by Langley Research Center workers to produce superior optomechanical structures for spacecraft and aircraft instrumentation. Basic features of these novel supports, such as dimensional stability, low cost, and ease of fabrication, also make them ideal for many commerical optical systems as well. Ceramic supports for optical components and benches offer important advantages over usual metal parts. Ceramic materials expand and contract only slightly with changes in temperature. Moreover, they are relatively inexpensive and lightweight.

  10. Electrospun Metal Nanofiber Webs as High-Performance Transparent Electrode

    KAUST Repository

    Wu, Hui

    2010-10-13

    Transparent electrodes, indespensible in displays and solar cells, are currently dominated by indium tin oxide (ITO) films although the high price of indium, brittleness of films, and high vacuum deposition are limiting their applications. Recently, solution-processed networks of nanostructures such as carbon nanotubes (CNTs), graphene, and silver nanowires have attracted great attention as replacements. A low junction resistance between nanostructures is important for decreasing the sheet resistance. However, the junction resistances between CNTs and boundry resistances between graphene nanostructures are too high. The aspect ratios of silver nanowires are limited to ∼100, and silver is relatively expensive. Here, we show high-performance transparent electrodes with copper nanofiber networks by a low-cost and scalable electrospinning process. Copper nanofibers have ultrahigh aspect ratios of up to 100000 and fused crossing points with ultralow junction resistances, which result in high transmitance at low sheet resistance, e.g., 90% at 50 Ω/sq. The copper nanofiber networks also show great flexibility and stretchabilty. Organic solar cells using copper nanowire networks as transparent electrodes have a power efficiency of 3.0%, comparable to devices made with ITO electrodes. © 2010 American Chemical Society.

  11. High performance solution-deposited amorphous indium gallium zinc oxide thin film transistors by oxygen plasma treatment

    KAUST Repository

    Nayak, Pradipta K.

    2012-05-16

    Solution-deposited amorphous indium gallium zinc oxide (a-IGZO) thin film transistors(TFTs) with high performance were fabricated using O2-plasma treatment of the films prior to high temperature annealing. The O2-plasma treatment resulted in a decrease in oxygen vacancy and residual hydrocarbon concentration in the a-IGZO films, as well as an improvement in the dielectric/channel interfacial roughness. As a result, the TFTs with O2-plasma treated a-IGZO channel layers showed three times higher linear field-effect mobility compared to the untreated a-IGZO over a range of processing temperatures. The O2-plasma treatment effectively reduces the required processing temperature of solution-deposited a-IGZO films to achieve the required performance.

  12. High-performance uncooled amorphous silicon TEC less XGA IRFPA with 17μm pixel-pitch

    Science.gov (United States)

    Trouilleau, C.; Fièque, B.; Noblet, S.; Giner, F.; Pochic, D.; Durand, A.; Robert, P.; Cortial, S.; Vilain, M.; Tissot, J. L.; Yon, J. J.

    2009-05-01

    The high level of accumulated expertise by ULIS and CEA/LETI on uncooled microbolometers made from amorphous silicon enables ULIS to develop 1024 x 768 (XGA) IRFPA formats with 17μm pixel-pitch to address high end, high performance applications. This detector has kept all the innovations developed on the full TV format readout integrated circuit (ROIC): detector configuration by serial link, two video outputs, low power consumption, wide electrical dynamic range... The specific appeal of this unit lies in the high image resolution it provides. The reduction of the pixel-pitch turns this XGA array into a product well adapted for high resolution yet compact systems. In the last part of the paper, we will look more closely at the high electro-optical performances of this IRFPA and the rapid performance enhancement. We will insist on NETD coupled with wide thermal dynamic range, as well as the outstanding uniformity and high pixel operability, achieved thanks to the mastering of the amorphous silicon technology coupled with the ROIC design. This technology node paves the way to high end VGA or 1/4VGA sensors as well as large diffusion compact smaller formats like 160 x 120 or smaller.

  13. Laser surface treatment of amorphous metals

    Science.gov (United States)

    Katakam, Shravana K.

    Amorphous materials are used as soft magnetic materials and also as surface coatings to improve the surface properties. Furthermore, the nanocrystalline materials derived from their amorphous precursors show superior soft magnetic properties than amorphous counter parts for transformer core applications. In the present work, laser based processing of amorphous materials will be presented. Conventionally, the nanocrystalline materials are synthesized by furnace heat treatment of amorphous precursors. Fe-based amorphous/nanocrystalline materials due to their low cost and superior magnetic properties are the most widely used soft magnetic materials. However, achieving nanocrystalline microstructure in Fe-Si-B ternary system becomes very difficult owing its rapid growth rate at higher temperatures and sluggish diffusion at low temperature annealing. Hence, nanocrystallization in this system is achieved by using alloying additions (Cu and Nb) in the ternary Fe-Si-B system. Thus, increasing the cost and also resulting in reduction of saturation magnetization. laser processing technique is used to achieve extremely fine nanocrystalline microstructure in Fe-Si-B amorphous precursor. Microstructure-magnetic Property-laser processing co-relationship has been established for Fe-Si-B ternary system using analytical techniques. Laser processing improved the magnetic properties with significant increase in saturation magnetization and near zero coercivity values. Amorphous materials exhibit excellent corrosion resistance by virtue of their atomic structure. Fe-based amorphous materials are economical and due to their ease of processing are of potential interest to synthesize as coatings materials for wear and corrosion resistance applications. Fe-Cr-Mo-Y-C-B amorphous system was used to develop thick coatings on 4130 Steel substrate and the corrosion resistance of the amorphous coatings was improved. It is also shown that the mode of corrosion depends on the laser processing

  14. High performance high-κ/metal gate complementary metal oxide semiconductor circuit element on flexible silicon

    KAUST Repository

    Torres Sevilla, G. A.

    2016-02-29

    Thinned silicon based complementary metal oxide semiconductor(CMOS)electronics can be physically flexible. To overcome challenges of limited thinning and damaging of devices originated from back grinding process, we show sequential reactive ion etching of silicon with the assistance from soft polymeric materials to efficiently achieve thinned (40 μm) and flexible (1.5 cm bending radius) silicon based functional CMOSinverters with high-κ/metal gate transistors. Notable advances through this study shows large area of silicon thinning with pre-fabricated high performance elements with ultra-large-scale-integration density (using 90 nm node technology) and then dicing of such large and thinned (seemingly fragile) pieces into smaller pieces using excimer laser. The impact of various mechanical bending and bending cycles show undeterred high performance of flexible siliconCMOSinverters. Future work will include transfer of diced silicon chips to destination site, interconnects, and packaging to obtain fully flexible electronic systems in CMOS compatible way.

  15. Strain Rate Induced Amorphization in Metallic Nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Y.; Cagin, T.; Goddard, W.A. III [Materials and Process Simulation Center, California Institute of Technology, Pasadena, California 91125 (United States); Ikeda, H.; Samwer, K.; Johnson, W.L. [Keck Laboratory of Engineering Materials, California Institute of Technology, Pasadena, California 91125 (United States)

    1999-04-01

    Using molecular dynamics simulations with a many-body force field, we studied the deformation of single crystal Ni and NiCu random alloy nanowires subjected to uniform strain rates but kept at 300thinspthinspK. For all strain rates, the Ni nanowire is elastic up to 7.5{percent} strain with a yield stress of 5.5thinspthinspGPa, far above that of bulk Ni. At high strain rates, we find that for both systems the crystalline phase transforms continuously to an amorphous phase, exhibiting a dramatic change in atomic short-range order and a near vanishing of the tetragonal shear elastic constant perpendicular to the tensile direction. This amorphization which occurs directly from the homogeneous, elastically deformed system with no chemical or structural inhomogeneities exhibits a new mode of amorphization. {copyright} {ital 1999} {ital The American Physical Society}

  16. Approaching Defect-free Amorphous Silicon Nitride by Plasma-assisted Atomic Beam Deposition for High Performance Gate Dielectric.

    Science.gov (United States)

    Tsai, Shu-Ju; Wang, Chiang-Lun; Lee, Hung-Chun; Lin, Chun-Yeh; Chen, Jhih-Wei; Shiu, Hong-Wei; Chang, Lo-Yueh; Hsueh, Han-Ting; Chen, Hung-Ying; Tsai, Jyun-Yu; Lu, Ying-Hsin; Chang, Ting-Chang; Tu, Li-Wei; Teng, Hsisheng; Chen, Yi-Chun; Chen, Chia-Hao; Wu, Chung-Lin

    2016-01-01

    In the past few decades, gate insulators with a high dielectric constant (high-k dielectric) enabling a physically thick but dielectrically thin insulating layer, have been used to replace traditional SiOx insulator and to ensure continuous downscaling of Si-based transistor technology. However, due to the non-silicon derivative natures of the high-k metal oxides, transport properties in these dielectrics are still limited by various structural defects on the hetero-interfaces and inside the dielectrics. Here, we show that another insulating silicon compound, amorphous silicon nitride (a-Si3N4), is a promising candidate of effective electrical insulator for use as a high-k dielectric. We have examined a-Si3N4 deposited using the plasma-assisted atomic beam deposition (PA-ABD) technique in an ultra-high vacuum (UHV) environment and demonstrated the absence of defect-related luminescence; it was also found that the electronic structure across the a-Si3N4/Si heterojunction approaches the intrinsic limit, which exhibits large band gap energy and valence band offset. We demonstrate that charge transport properties in the metal/a-Si3N4/Si (MNS) structures approach defect-free limits with a large breakdown field and a low leakage current. Using PA-ABD, our results suggest a general strategy to markedly improve the performance of gate dielectric using a nearly defect-free insulator. PMID:27325155

  17. Approaching Defect-free Amorphous Silicon Nitride by Plasma-assisted Atomic Beam Deposition for High Performance Gate Dielectric

    Science.gov (United States)

    Tsai, Shu-Ju; Wang, Chiang-Lun; Lee, Hung-Chun; Lin, Chun-Yeh; Chen, Jhih-Wei; Shiu, Hong-Wei; Chang, Lo-Yueh; Hsueh, Han-Ting; Chen, Hung-Ying; Tsai, Jyun-Yu; Lu, Ying-Hsin; Chang, Ting-Chang; Tu, Li-Wei; Teng, Hsisheng; Chen, Yi-Chun; Chen, Chia-Hao; Wu, Chung-Lin

    2016-06-01

    In the past few decades, gate insulators with a high dielectric constant (high-k dielectric) enabling a physically thick but dielectrically thin insulating layer, have been used to replace traditional SiOx insulator and to ensure continuous downscaling of Si-based transistor technology. However, due to the non-silicon derivative natures of the high-k metal oxides, transport properties in these dielectrics are still limited by various structural defects on the hetero-interfaces and inside the dielectrics. Here, we show that another insulating silicon compound, amorphous silicon nitride (a-Si3N4), is a promising candidate of effective electrical insulator for use as a high-k dielectric. We have examined a-Si3N4 deposited using the plasma-assisted atomic beam deposition (PA-ABD) technique in an ultra-high vacuum (UHV) environment and demonstrated the absence of defect-related luminescence; it was also found that the electronic structure across the a-Si3N4/Si heterojunction approaches the intrinsic limit, which exhibits large band gap energy and valence band offset. We demonstrate that charge transport properties in the metal/a-Si3N4/Si (MNS) structures approach defect-free limits with a large breakdown field and a low leakage current. Using PA-ABD, our results suggest a general strategy to markedly improve the performance of gate dielectric using a nearly defect-free insulator.

  18. Amorphous metal distribution transformers: The energy-efficient alternative

    Energy Technology Data Exchange (ETDEWEB)

    Garrity, T.F. [GE Power Systems, Schenectady, NY (United States)

    1994-12-31

    Amorphous metal distribution transformers have been commercially available for the past 13 years. During that time, they have realized the promise of exceptionally high core efficiency as compared to silicon steel transformer cores. Utility planners today must consider all options available to meet the requirements of load growth. While additional generation capacity will be added, many demand-side initiatives are being undertaken as complementary programs to generation expansion. The efficiency improvement provided by amorphous metal distribution transformers deserves to be among the demand-side options. The key to understanding the positive impact of amorphous metal transformer efficiency is to consider the aggregate contribution those transformers can make towards demand reduction. It is estimated that distribution transformer core losses comprise at least 1% of the utility`s peak demand. Because core losses are continuous, any significant reduction in their magnitude is of great significance to the planner. This paper describes the system-wide economic contributions amorphous metal distribution transformers can make to a utility and suggests evaluation techniques that can be used. As a conservation tool, the amorphous metal transformer contributes to reduced power plant emissions. Calibration of those emissions reductions is also discussed in the paper.

  19. Energy reversible switching from amorphous metal based nanoelectromechanical switch

    KAUST Repository

    Mayet, Abdulilah M.

    2013-08-01

    We report observation of energy reversible switching from amorphous metal based nanoelectromechanical (NEM) switch. For ultra-low power electronics, NEM switches can be used as a complementary switching element in many nanoelectronic system applications. Its inherent zero power consumption because of mechanical detachment is an attractive feature. However, its operating voltage needs to be in the realm of 1 volt or lower. Appropriate design and lower Young\\'s modulus can contribute achieving lower operating voltage. Therefore, we have developed amorphous metal with low Young\\'s modulus and in this paper reporting the energy reversible switching from a laterally actuated double electrode NEM switch. © 2013 IEEE.

  20. Laser spot welding of cobalt-based amorphous metal foils

    International Nuclear Information System (INIS)

    The results concerning weldability of amorphous alloy (VAC 6025F) in shape of foils and the quality of laser-spot welded joints are presented in this paper. The aim of the research was the production of a high quality welding joint, by preserving the amorphous structure. The quality of the joint was tested by shear strength analysis and microhardness measuring. The metallographic studies were made by using optical microscope and SEM. The results show that (1) overlapped Co based amorphous metals foils can be welded with high-quality by a pulsed Nd: YAG-Laser, but only within a very narrow laser parameter window; (2) the laser welded spots show comparably high strength as the basic material; (3) the structure of the welded spot remains amorphous, so that the same characteristics as the base material can be achieved. (author)

  1. Features of exoelectron emission in amorphous metallic alloys

    CERN Document Server

    Veksler, A S; Morozov, I L; Semenov, A L

    2001-01-01

    The peculiarities of the photothermostimulated exoelectron emission in amorphous metallic alloys of the Fe sub 6 sub 4 Co sub 2 sub 1 B sub 1 sub 5 composition are studied. It is established that the temperature dependences of the exoelectron emission spectrum adequately reflect the two-stage character of the amorphous alloy transition into the crystalline state. The exoelectron emission spectrum is sensitive to the variations in the modes of the studied sample thermal treatment. The thermal treatment of the amorphous metallic alloy leads to growth in the intensity of the exoelectrons yield. The highest growth in the intensify of the exoelectron emission was observed in the alloys at the initial stage of their crystallization

  2. Structural models for amorphous transition metal binary alloys

    International Nuclear Information System (INIS)

    A dense random packing of 445 hard spheres with two different diameters in a concentration ratio of 3 : 1 was hand-built to simulate the structure of amorphous transition metal-metalloid alloys. By introducing appropriate pair potentials of the Lennard-Jones type, the structure is dynamically relaxed by minimizing the total energy. The radial distribution functions (RDF) for amorphous Fe0.75P0.25, Ni0.75P0.25, Co0.75P0.25 are obtained and compared with the experimental data. The calculated RDF's are resolved into their partial components. The results indicate that such dynamically constructed models are capable of accounting for some subtle features in the RDF of amorphous transition metal-metalloid alloys

  3. Amorphous Metal Composites for use in Long-Life, Low-Temperature Gearboxes Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed concept is to explore the use of Amorphous Metals (AMs) and Amorphous Metal Composites (AMCs) (fabricated entirely at JPL) for use as gears and bearing...

  4. Unveiling the complex electronic structure of amorphous metal oxides

    OpenAIRE

    Arhammar, C.; Pietzsch, A; Bock, N.; Holmstrom, E.; Araujo, C. M.; Grasjo, J.; Zhao, S.; Green, S; Peery, T.; Hennies, F.; Amerioun, S.; Fohlisch, A.; Schlappa, J.; Schmitt, T; Strocov, V. N.

    2011-01-01

    Amorphous materials represent a large and important emerging area of material’s science. Amorphous oxides are key technological oxides in applications such as a gate dielectric in Complementary metal-oxide semiconductor devices and in Silicon-Oxide-Nitride-Oxide-Silicon and TANOS (TaN-Al2O3-Si3N4-SiO2-Silicon) flash memories. These technologies are required for the high packing density of today’s integrated circuits. Therefore the investigation of defect states in these structures is crucial....

  5. A high-performance liquid chromatography method for determining transition metal content in proteins.

    Science.gov (United States)

    Atanassova, Anelia; Lam, Robert; Zamble, Deborah B

    2004-12-01

    Transition metals are common components of cellular proteins and the detailed study of metalloproteins necessitates the identification and quantification of bound metal ions. Screening for metals is also an informative step in the initial characterization of the numerous unknown and unclassified proteins now coming through the proteomic pipeline. We have developed a high-performance liquid chromatography method for the quantitative determination of the most prevalent biological transition metals: manganese, iron, cobalt, nickel, copper, and zinc. The method is accurate and simple and can be adapted for automated high-throughput studies. The metal analysis involves acid hydrolysis to release the metal ions into solution, followed by ion separation on a mixed-bead ion-exchange column and absorbance detection after postcolumn derivatization with the metallochromic indicator 4-(2-pyridylazo)resorcinol. The potential interferences by common components of protein solutions were investigated. The metal content of a variety of metalloproteins was analyzed and the data were compared to data obtained from inductively coupled plasma-atomic emission spectroscopy. The sensitivity of the assay allows for the detection of 0.1-0.8 nmol, depending on the metal. The amount of protein required is governed by the size of the protein and the fraction of protein with metal bound. For routine analysis 50 microg was used but for many proteins 10 microg would be sufficient. The advantages, disadvantages, and possible applications of this method are discussed. PMID:15519577

  6. Amorphous metal formulations and structured coatings for corrosion and wear resistance

    Science.gov (United States)

    Farmer, Joseph C.

    2011-12-13

    A system for coating a surface comprising providing a source of amorphous metal that contains more than 11 elements and applying the amorphous metal that contains more than 11 elements to the surface by a spray. Also a coating comprising a composite material made of amorphous metal that contains more than 11 elements. An apparatus for producing a corrosion-resistant amorphous-metal coating on a structure comprises a deposition chamber, a deposition source in the deposition chamber that produces a deposition spray, the deposition source containing a composite material made of amorphous metal that contains more than 11 elements, and a system that directs the deposition spray onto the structure.

  7. Metal chloride-treated graphene oxide to produce high-performance polymer solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Eun-Su; Noh, Yong-Jin; Kwon, Sung-Nam; Na, Seok-In, E-mail: nsi12@jbnu.ac.kr [Professional Graduate School of Flexible and Printable Electronics and Polymer Materials Fusion Research Center, Chonbuk National University, 664-14, Deokjin-dong, Deokjin-gu, Jeonju-si, Jeollabuk-do 561-756 (Korea, Republic of); Jeon, Ye-Jin [School of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Kim, Seok-Soon, E-mail: sskim@kunsan.ac.kr [Department of Nano and Chemical Engineering, Kunsan National University, Kunsan, Jeollabuk-do 753-701 (Korea, Republic of); Kim, Tae-Wook [Soft Innovative Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology, San 101, Eunha-ri, Bongdong-eup, Wanju-gun, Jeollabuk-do 565-905 (Korea, Republic of)

    2015-07-13

    We introduce a simple but effective graphene oxide (GO) modification with metal chloride treatments to produce high-performance polymer solar cells (PSCs). The role of various metal chlorides on GO and their effects on device performances of PSCs was investigated. X-ray photoelectron spectroscopy, ultraviolet photoemission spectroscopy, and current-voltage measurement studies demonstrated that metal chloride can induce a p-doping effect and increase the GO work-function, thus resulting in an improved built-in potential and interfacial resistance in PSCs. The resultant PSCs with metal chloride exhibited improved device efficiency than those with the neat GO. Furthermore, with the metal chloride-doped GO, we finally achieved an excellent PSC-efficiency of 6.58% and a very desirable device stability, which constitute a highly similar efficiency but much better PSC life-time to conventional device with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). This study could be a valuable way to produce various PEDOT:PSS alternatives and beneficial for producing high-performance and cost-efficient polymeric devices.

  8. Extraction of valuable metals from amorphous solid wastes

    Directory of Open Access Journals (Sweden)

    E. David

    2007-11-01

    Full Text Available Purpose: This paper undertakes to assess what opportunities exist for the economical recovery of valuable metals from amorphous solid wastes that may be considered as“synthetic ores”. Also, this work is an attempt to optimize a leaching process that is the most determinant step of hydrometallurgical process used to extract metals from ores.Design/methodology/approach: The samples of amorphous material formed from spent industrial catalysts based on Cu, Ni / γ-Al2O3 were physically and chemically characterized by atomic absortion spectrometry (AAS and chemical analysis for to determine the metals content. Then leaching studies were carried out under room temperature, atmospheric pressure and without gas injection in both sulphuric acid with hydrogen peroxide addition and ammoniacal media for to decide which of them would be the best treatment for this kind of waste materials. Also, the dissolution behaviour of Cu, Ni and Al metals was studied in order to assure the best metal recovery conditions in subsequent processes such as solvent extraction , precipitation or cementation techniques.Findings: The results revealed that addition of hydrogen peroxide to sulphuric acid up to 0.2 M H2O2 concentration enhanced leaching of metals remarkably and thereafter remained relatively constant. The highest extraction of metals was found to be 90% Cu, 85% Ni and 80% Al for the following experimental conditions: H2SO4 2M, H2O2 0.2 M, A 5:1 liquid to solid ratio (L/S.The use of ammoniacal media for leaching allowed the extraction of Cu, Ni and Al but rates of recovery were only about 45 % for Cu, 43 % for Ni and 44 % for Al, much lower than those obtained for sulphuric acid leaching.Research limitations/implications: The investigated process is suitable for all amorphous solid wastes with significant content in metals such as copper, nickel, aluminium.Practical implications: Promising directions for adaptation of appropriate and economic separation

  9. Controlled rejuvenation of amorphous metals with thermal processing.

    Science.gov (United States)

    Wakeda, Masato; Saida, Junji; Li, Ju; Ogata, Shigenobu

    2015-05-26

    Rejuvenation is the configurational excitation of amorphous materials and is one of the more promising approaches for improving the deformability of amorphous metals that usually exhibit macroscopic brittle fracture modes. Here, we propose a method to control the level of rejuvenation through systematic thermal processing and clarify the crucial feasibility conditions by means of molecular dynamics simulations of annealing and quenching. We also experimentally demonstrate rejuvenation level control in Zr(55)Al(10)Ni(5)Cu(30) bulk metallic glass. Our local heat-treatment recipe (rising temperature above 1.1T(g), followed by a temperature quench rate exceeding the previous) opens avenue to modifying the glass properties after it has been cast and processed into near component shape, where a higher local cooling rate may be afforded by for example transient laser heating, adding spatial control and great flexibility to the processing.

  10. High-Performance, Solution-Processed, Embedded Multiscale Metallic Transparent Conductors.

    Science.gov (United States)

    Oh, Yong Suk; Lee, Hyunwoo; Choi, Dong Yun; Lee, Sung-Uk; Kim, Hojin; Yoo, Seunghyup; Park, Inkyu; Sung, Hyung Jin

    2016-05-01

    High-performance multiscale metallic transparent conductors (TCs) are demonstrated by incorporating Ag nanowire (NW) networks into microscale Ag grid structures. Highly conductive Ag grids are fabricated via direct imprinting of an Ag ion ink using a reservoir-assisted mold. In this mold, a macroscale cavity, called the "reservoir", is designed to connect to a grid-patterned cavity. The reservoir has a large cavity volume, which reduces unwanted residual layers within the grid spacings by introducing a thinner liquid film. The reservoir undergoes a large volume reduction during mold deformation, which improves ink filling within the grid-patterned cavity through deformation-induced ink injection. The multiscale metallic TCs show a sheet resistance (Rs) of polymer matrix. The embedded multiscale metallic TCs show reasonable electromechanical and chemical stability. The utility of these TCs is demonstrated by fabricating flexible organic solar cells. PMID:27074908

  11. Advances in chemical synthesis and application of metal-metalloid amorphous alloy nanoparticulate catalysts

    Institute of Scientific and Technical Information of China (English)

    WU Zhijie; LI Wei; ZHANG Minghui; TAO Keyi

    2007-01-01

    This paper reviews the advances in the chemical synthesis and application of metal-metalloid amorphous alloy nanoparticles consisting of transition metal (M) and metalloid elements (B,P).After a brief introduction on the history of amorphous alloy catalysts,the paper focuses on the properties and characterization of amorphous alloy catalysts,and recent developments in the solution-phase synthesis of amorphous alloy nanoparticles.This paper further outlines the applications of amorphous alloys,with special emphasis on the problems and strategies for the application of amorphous alloy nanoparticles in catalytic reactions.

  12. Design of multi materials combining crystalline and amorphous metallic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Volland, A.; Ragani, J.; Liu, Y.; Gravier, S.; Suery, M. [Grenoble University/CNRS, SIMAP Laboratory, Grenoble INP/UJF, 38402 Saint-Martin d' Heres (France); Blandin, J.J., E-mail: jean-jacques.blandin@simap.grenoble-inp.fr [Grenoble University/CNRS, SIMAP Laboratory, Grenoble INP/UJF, 38402 Saint-Martin d' Heres (France)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer Elaboration of multi materials associating metallic glasses and conventional crystalline alloys by co-deformation performed at temperatures close to the glass transition temperature of the metallic glasses. Black-Right-Pointing-Pointer Elaboration of filamentary metal matrix composites with a core in metallic glass by co extrusion. Black-Right-Pointing-Pointer Sandwich structures produced by co-pressing. Black-Right-Pointing-Pointer Detection of atomic diffusion from the glass to the crystalline alloys during the processes. Black-Right-Pointing-Pointer Good interfaces between the metallic glasses and the crystalline alloys, as confirmed by mechanical characterisation. - Abstract: Multi materials, associating zirconium based bulk metallic glasses and crystalline metallic alloys like magnesium alloys or copper are elaborated by co-deformation processing performed in the supercooled liquid regions (SLR) of the bulk metallic glasses. Two processes are investigated: co-extrusion and co-pressing. In the first case, filamentary composites with various designs can be produced whereas in the second case sandwich structures are obtained. The experimental window (temperature, time) in which processing can be carried out is directly related to the crystallisation resistance of the glass which requires getting information about the crystallisation conditions in the selected metallic glasses. Thermoforming windows are identified for the studied BMGs by thermal analysis and compression tests in their SLR. The mechanical properties of the produced multi materials are investigated thanks to specifically developed mechanical devices and the interfaces between the amorphous and the crystalline alloys are characterised.

  13. Sub-100 °C solution processed amorphous titania nanowire thin films for high-performance perovskite solar cells

    Science.gov (United States)

    Wu, Wu-Qiang; Chen, Dehong; Huang, Fuzhi; Cheng, Yi-Bing; Caruso, Rachel A.

    2016-10-01

    The present work demonstrates a facile one-step process to fabricate thin films of amorphous titania nanowires on transparent conducting oxide substrates via hydrolysis of potassium titanium oxide oxalate in an aqueous solution at 90 °C. The resultant titania nanowire thin films (that have not undergone further annealing) are efficient electron transport layers in CH3NH3PbI3 perovskite solar cells, yielding full sun solar-to-electricity conversion efficiencies of up to 14.67% and a stabilized efficiency of 14.00% under AM 1.5G one sun illumination, comparable to high temperature sintered TiO2 counterparts. The high photovoltaic performance is attributed to the porous nanowire network that facilitates perovskite infiltration, its unique 1D geometry and excellent surface coverage for efficient electron transport, as well as suppressed charge recombination between FTO and perovskite.

  14. Codoping of zinc and tungsten for practical high-performance amorphous indium-based oxide thin film transistors

    Energy Technology Data Exchange (ETDEWEB)

    Kizu, Takio, E-mail: KIZU.Takio@nims.go.jp, E-mail: TSUKAGOSHI.Kazuhito@nims.go.jp; Mitoma, Nobuhiko; Tsukagoshi, Kazuhito, E-mail: KIZU.Takio@nims.go.jp, E-mail: TSUKAGOSHI.Kazuhito@nims.go.jp [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Miyanaga, Miki; Awata, Hideaki [Advanced Materials R& D Laboratories, Sumitomo Electric Industries, Ltd., 1-1-1 Koyakita, Itami, Hyogo 664-0016 (Japan); Nabatame, Toshihide [MANA Foundry and MANA Advanced Device Materials Group, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

    2015-09-28

    Using practical high-density sputtering targets, we investigated the effect of Zn and W codoping on the thermal stability of the amorphous film and the electrical characteristics in thin film transistors. zinc oxide is a potentially conductive component while W oxide is an oxygen vacancy suppressor in oxide films. The oxygen vacancy from In-O and Zn-O was suppressed by the W additive because of the high oxygen bond dissociation energy. With controlled codoping of W and Zn, we demonstrated a high mobility with a maximum mobility of 40 cm{sup 2}/V s with good stability under a negative bias stress in InWZnO thin film transistors.

  15. Codoping of zinc and tungsten for practical high-performance amorphous indium-based oxide thin film transistors

    International Nuclear Information System (INIS)

    Using practical high-density sputtering targets, we investigated the effect of Zn and W codoping on the thermal stability of the amorphous film and the electrical characteristics in thin film transistors. zinc oxide is a potentially conductive component while W oxide is an oxygen vacancy suppressor in oxide films. The oxygen vacancy from In-O and Zn-O was suppressed by the W additive because of the high oxygen bond dissociation energy. With controlled codoping of W and Zn, we demonstrated a high mobility with a maximum mobility of 40 cm2/V s with good stability under a negative bias stress in InWZnO thin film transistors

  16. Double-layered metal grating for high-performance refractive index sensing.

    Science.gov (United States)

    Li, Guozhen; Shen, Yang; Xiao, Guohui; Jin, Chongjun

    2015-04-01

    The detection of minuscule changes in the local refractive index by localized surface plasmon resonances (LSPRs), carried by metal nanostructures, has been used successfully in applications such as real-time and label-free detection of molecular binding events. However, localized plasmons demonstrate 1-2 orders of magnitude lower figure of merit (FOM) compared with their propagating counterparts. Here, we propose and experimentally demonstrate a high-performance refractive index sensor based on a structure of double-layered metal grating (DMG) with an FOM and FOM* reaching 38 and 40 respectively under normal incidence. Such a high FOM and FOM* arise from a result of a sharp fano resonance, which is caused by the coherent interference between the LSPR from the individual top gold stripes and Wood's anomaly (WA). Moreover, a small conformal decay length of ~68 nm is determined in DMG, indicating that the DMG is a promising candidate for label-free biomedical sensing. PMID:25968735

  17. Excimer laser crystallization of amorphous silicon on metallic substrate

    Science.gov (United States)

    Delachat, F.; Antoni, F.; Slaoui, A.; Cayron, C.; Ducros, C.; Lerat, J.-F.; Emeraud, T.; Negru, R.; Huet, K.; Reydet, P.-L.

    2013-06-01

    An attempt has been made to achieve the crystallization of silicon thin film on metallic foils by long pulse duration excimer laser processing. Amorphous silicon thin films (100 nm) were deposited by radiofrequency magnetron sputtering on a commercial metallic alloy (N42-FeNi made of 41 % of Ni) coated by a tantalum nitride (TaN) layer. The TaN coating acts as a barrier layer, preventing the diffusion of metallic impurities in the silicon thin film during the laser annealing. An energy density threshold of 0.3 J cm-2, necessary for surface melting and crystallization of the amorphous silicon, was predicted by a numerical simulation of laser-induced phase transitions and witnessed by Raman analysis. Beyond this fluence, the melt depth increases with the intensification of energy density. A complete crystallization of the layer is achieved for an energy density of 0.9 J cm-2. Scanning electron microscopy unveils the nanostructuring of the silicon after laser irradiation, while cross-sectional transmission electron microscopy reveals the crystallites' columnar growth.

  18. Bulk amorphous metallic alloys: Synthesis by fluxing techniques and properties

    Energy Technology Data Exchange (ETDEWEB)

    He, Yi; Shen, Tongde; Schwarz, R.B.

    1997-05-01

    Bulk amorphous alloys having dimensions of at least 1 cm diameter have been prepared in the Pd-Ni-P, Pd-Cu-P, Pd-Cu-Ni-P, and Pd-Ni-Fe-P systems using a fluxing and water quenching technique. The compositions for bulk glass formation have been determined in these systems. For these bulk metallic glasses, the difference between the crystallization temperature T{sub x}, and the glass transition temperature T{sub g}, {Delta}T = T{sub x} - T{sub g}, ranges from 60 to 1 10 K. These large values of {Delta}T open the possibility for the fabrication of amorphous near net-shape components using techniques such as injection molding. The thermal, elastic, and magnetic properties of these alloys have been studied, and we have found that bulk amorphous Pd{sub 40}Ni{sub 22.5}Fe{sub 17.5}P{sub 20} has spin glass behavior for temperatures below 30 K. 65 refs., 14 figs., 3 tabs.

  19. Scattering effect of the high-index dielectric nanospheres for high performance hydrogenated amorphous silicon thin-film solar cells.

    Science.gov (United States)

    Yang, Zhenhai; Gao, Pingqi; Zhang, Cheng; Li, Xiaofeng; Ye, Jichun

    2016-01-01

    Dielectric nanosphere arrays are considered as promising light-trapping designs with the capability of transforming the freely propagated sunlight into guided modes. This kinds of designs are especially beneficial to the ultrathin hydrogenated amorphous silicon (a-Si:H) solar cells due to the advantages of using lossless material and easily scalable assembly. In this paper, we demonstrate numerically that the front-sided integration of high-index subwavelength titanium dioxide (TiO2) nanosphere arrays can significantly enhance the light absorption in 100 nm-thick a-Si:H thin films and thus the power conversion efficiencies (PCEs) of related solar cells. The main reason behind is firmly attributed to the strong scattering effect excited by TiO2 nanospheres in the whole waveband, which contributes to coupling the light into a-Si:H layer via two typical ways: 1) in the short-waveband, the forward scattering of TiO2 nanospheres excite the Mie resonance, which focuses the light into the surface of the a-Si:H layer and thus provides a leaky channel; 2) in the long-waveband, the transverse waveguided modes caused by powerful scattering effectively couple the light into almost the whole active layer. Moreover, the finite-element simulations demonstrate that photocurrent density (Jph) can be up to 15.01 mA/cm(2), which is 48.76% higher than that of flat system. PMID:27455911

  20. High-performance uncooled amorphous silicon VGA and XGA IRFPA with 17μm pixel-pitch

    Science.gov (United States)

    Tissot, J. L.; Tinnes, S.; Durand, A.; Minassian, C.; Robert, P.; Vilain, M.

    2010-10-01

    The high level of accumulated expertise by ULIS and CEA/LETI on uncooled microbolometers made from amorphous silicon with 45μm, 35μm and 25μm, enables ULIS to develop VGA and XGA IRFPA formats with 17μm pixel-pitch to fulfill every applications. These detector keeps all the recent innovations developed on the 25μm pixel-pitch ROIC (detector configuration by serial link, low power consumption and wide electrical dynamic range). The specific appeal of these units lies in the high spatial resolution it provides while keeping the small thermal time constant. The reduction of the pixel-pitch turns the TEC-less VGA array into a product well adapted for high resolution and compact systems and the XGA a product well adapted for high resolution imaging systems. High electro-optical performances have been demonstrated with NETD ROIC design. This technology node paves the way to high end products as well as low end compact smaller formats like 320 x 240 and 160 x 120 or smaller.

  1. High performance Ω-gated Ge nanowire MOSFET with quasi-metallic source/drain contacts.

    Science.gov (United States)

    Burchhart, T; Zeiner, C; Hyun, Y J; Lugstein, A; Hochleitner, G; Bertagnolli, E

    2010-10-29

    Ge nanowires (NWs) about 2 µm long and 35 nm in diameter are grown heteroepitaxially on Si(111) substrates in a hot wall low-pressure chemical vapor deposition (LP-CVD) system using Au as a catalyst and GeH(4) as precursor. Individual NWs are contacted to Cu pads via e-beam lithography, thermal evaporation and lift-off techniques. Self-aligned and atomically sharp quasi-metallic copper-germanide source/drain contacts are achieved by a thermal activated phase formation process. The Cu(3)Ge segments emerge from the Cu contact pads through axial diffusion of Cu which was controlled in situ by SEM, thus the active channel length of the MOSFET is adjusted without any restrictions from a lithographic process. Finally the conductivity of the channel is enhanced by Ga(+) implantation leading to a high performance Ω-gated Ge-NW MOSFET with saturation currents of a few microamperes. PMID:20876973

  2. A facile solution combustion synthesis of nanosized amorphous iron oxide incorporated in a carbon matrix for use as a high-performance lithium ion battery anode material

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Chunyu, E-mail: chunyu6zhu@gmail.com; Saito, Genki; Akiyama, Tomohiro

    2015-06-05

    Highlights: • Iron oxide–carbon composite was fabricated by facile solution combustion synthesis. • Iron oxide nanoparticles of about 5 nm were uniformly embedded in dense carbon matrix. • The composite exhibited enhanced cyclability and rate capability. • A high capacity of 687 mA h g{sup −1} after 200 cycles at a current rate of 0.5 A g{sup −1} were obtained. - Abstract: An amorphous iron oxide–carbon composite has been fabricated through an effective, inexpensive, and scalable method employing solution combustion synthesis. Amorphous iron oxide nanoparticles with diameters of about 5 nm were synthesized and uniformly embedded in a dense carbon matrix. The synthesized composite exhibits enhanced cyclability and rate capability, showing a high reversible capacity of 687 mA h g{sup −1} after 200 discharge/charge cycles at a current rate of 0.5 A g{sup −1}, compared to the 400 mA h g{sup −1} observed for Fe{sub 2}O{sub 3} nanoparticles. This enhanced performance was retained despite more demanding conditions, delivering a high capacity of about 525 mA h g{sup −1} and a nearly perfect coulombic efficiency even after 400 cycles at 1 A g{sup −1}. The easy production and superior electrochemical properties of this composite suggest that it is a promising material for use as an anode material in high performance lithium ion batteries.

  3. The fabrication and study of metal chelating stationary phases for the high performance separation of metal ions

    International Nuclear Information System (INIS)

    The preparation and characterisation of chelating sorbents suitable for the high efficiency separation of trace metals in complex samples, using a single column and isocratic elution, is described. Hydrophobic, neutral polystyrene divinylbenzene resins were either impregnated with chelating dyes or dynamically modified with heterocyclic organic acids, using physical adsorption and chemisorption processes respectively. A hydrophilic silica substrate was covalently bonded with a chelating aminomethylphosphonic acid group, to assess the chelating potential of this molecule. These substrates were characterised in terms of metal retention capability (selectivity coefficients and capacity factors), separation performance, column efficiency and suitability for analytical applications. Chelating molecules with different ligand groups were found to have unique selectivity patterns dependant upon the conditional stability constants of the chelate. Other factors, including mobile phase constituents - complexing agents, ionic strength and pH, column length and column capacity were additionally investigated to examine their effect upon the separation profiles achieved. The promising metal separation abilities illustrated by a number of these chelating columns were exploited for the determination of trace toxic metals in complex sample matrices using High Performance Chelation Ion Chromatography (HPCIC). This included the determination of beryllium in a certified stream sediment, uranium in seawater and a certified stream sediment, and cadmium, lead and copper in a certified rice flour. The results for each analysis fell within the certified limits, and reproducibility was good. The optimisation of post column detection systems using chromogenic ligands additionally gave good detection limits for the metals in each separation system. (author)

  4. Carrier Transport at Metal/Amorphous Hafnium-Indium-Zinc Oxide Interfaces.

    Science.gov (United States)

    Kim, Seoungjun; Gil, Youngun; Choi, Youngran; Kim, Kyoung-Kook; Yun, Hyung Joong; Son, Byoungchul; Choi, Chel-Jong; Kim, Hyunsoo

    2015-10-14

    In this paper, the carrier transport mechanism at the metal/amorphous hafnium-indium-zinc oxide (a-HIZO) interface was investigated. The contact properties were found to be predominantly affected by the degree of interfacial reaction between the metals and a-HIZO; that is, a higher tendency to form metal oxide phases leads to excellent Ohmic contact via tunneling, which is associated with the generated donor-like oxygen vacancies. In this case, the Schottky-Mott theory is not applicable. Meanwhile, metals that do not form interfacial metal oxide, such as Pd, follow the Schottky-Mott theory, which results in rectifying Schottky behavior. The Schottky characteristics of the Pd contact to a-HIZO can be explained in terms of the barrier inhomogeneity model, which yields a mean barrier height of 1.40 eV and a standard deviation of 0.14 eV. The work function of a-HIZO could therefore be estimated as 3.7 eV, which is in good agreement with the ultraviolet photoelectron spectroscopy (3.68 eV). Our findings will be useful for establishing a strategy to form Ohmic or Schottky contacts to a-HIZO films, which will be essential for fabricating reliable high-performance electronic devices. PMID:26411354

  5. Remarkably stable amorphous metal oxide grown on Zr-Cu-Be metallic glass.

    Science.gov (United States)

    Lim, Ka Ram; Kim, Chang Eun; Yun, Young Su; Kim, Won Tae; Soon, Aloysius; Kim, Do Hyang

    2015-12-14

    In the present study, we investigated the role of an aliovalent dopant upon stabilizing the amorphous oxide film. We added beryllium into the Zr50Cu50 metallic glass system, and found that the amorphous oxide layer of Be-rich phase can be stabilized even at elevated temperature above Tg of the glass matrix. The thermal stability of the amorphous oxide layer is substantially enhanced due to Be addition. As confirmed by high-temperature cross-section HR-TEM, fully disordered Be-added amorphous layer is observed, while the rapid crystallization is observed without Be. To understand the role of Be, we employed ab-initio molecular dynamics to compare the mobility of ions with/without Be dopant, and propose a disordered model where Be dopant occupies Zr vacancy and induces structural disorder to the amorphous phase. We find that the oxygen mobility is slightly suppressed due to Be dopant, and Be mobility is unexpectedly lower than that of oxygen, which we attribute to the aliovalent nature of Be dopant whose diffusion always accompany multiple counter-diffusion of other ions. Here, we explain the origin of superior thermal stability of amorphous oxide film in terms of enhanced structural disorder and suppressed ionic mobility due to the aliovalent dopant.

  6. Large-scale synthesis of hybrid metal oxides through metal redox mechanism for high-performance pseudocapacitors

    Science.gov (United States)

    Ren, Zhonghua; Li, Jianpeng; Ren, Yaqi; Wang, Shuguang; Qiu, Yejun; Yu, Jie

    2016-01-01

    Electrochemical performance and production cost are the main concerns for the practical application of supercapacitors. Here we report a simple and universally applicable method to prepare hybrid metal oxides by metal redox reaction utilizing the inherent reducibility of metals and oxidbility of for the first time. As an example, Ni(OH)2/MnO2 hybrid nanosheets (NMNSs) are grown for supercapacitor application by self-reaction of Ni foam substrates in KMnO4 solution at room temperature. The obtained hybrid nanosheets exhibit high specific capacitance (2,937 F g-1). The assembled solid-state asymmetric pseudocapacitors possess ultrahigh energy density of 91.13 Wh kg-1 (at the power density of 750 W kg-1) and extraordinary cycling stability with 92.28% capacitance retention after 25,000 cycles. Co(OH)2/MnO2 and Fe2O3/MnO2 hybrid oxides are also synthesized through this metal redox mechanism. This green and low-cost method is capable of large-scale production and one-step preparation of the electrodes, holding promise for practical application of high-performance pseudocapacitors.

  7. PREFACE: 13th International Conference on Liquid and Amorphous Metals

    Science.gov (United States)

    Popel, Pjotr; Gelchinskii, Boris; Sidorov, Valeriy; Son, Leonid; Sabirzjanov, Alexandre

    2007-06-01

    The state of the art in the field of liquid and amorphous metals and alloys is regularly updated through two series of complementary international conferences, the LAM (Liquid and Amorphous Metals) and the RQ (Rapidly Quenched Materials). The first series of the conferences started as LM-1 in 1966 at Brookhaven for the basic understanding of liquid metals. The subsequent LM conferences were held in Tokyo (1972) and Bristol (1976). The conference was renewed in Grenoble (1980) as a LAM conference including amorphous metals and continued in Los Angeles (1983), Garmisch-Partenkirchen (1986), Kyoto (1989), Vienna (1992), Chicago (1995), Dortmund (1998), Yokohama (2001) and Metz (2004). The conferences are mainly devoted to liquid and amorphous metals and alloys. However, communications on some non-metallic systems such as semi conductors, quasicrystals etc, were accepted as well. The conference tradition strongly encourages the participation of junior researchers and graduate students. The 13th conference of the LAM series was organized in Ekaterinburg, Russia, by the Institute of Metallurgy of the Ural Branch of the Russian Academy of Sciences (IMet UB RAS) and Ural State Pedagogical University (USPU) and held on 8-13 July 2007 under the chairmanship of Professors Pjotr Popel (USPU) and Boris Gelchinskii (IMet UB RAS). There were 242 active and about 60 guest participants from 20 countries who attended the conference. There were no parallel sessions and all oral reports were separated into three groups: invited talks (40 min), full-scale (25 min) and brief (15 min) oral reports. The program included 10 sessions, ranging from purely theoretical subjects to technological application of molten and amorphous alloys. The following sessions took place: A) Electronic structure and transport, magnetic properties; B) Phase transitions; C) Structure; D) Atomic dynamics and transport; E) Thermodynamics; F) Modelling, simulation; G) Surface and interface; H) Mechanical properties

  8. High performance felt-metal-wick heat pipe for solar receivers

    Science.gov (United States)

    Andraka, Charles E.; Moss, Timothy A.; Baturkin, Volodymyr; Zaripov, Vladlen; Nishchyk, Oleksandr

    2016-05-01

    Sodium heat pipes have been identified as a potentially effective heat transport approach for CSP systems that require near-isothermal input to power cycles or storage, such as dish Stirling and highly recuperated reheat-cycle supercritical CO2 turbines. Heat pipes offer high heat flux capabilities, leading to small receivers, as well as low exergetic losses through isothermal coupling with the engine. Sandia developed a felt metal wick approach in the 1990's, and demonstrated very high performance1. However, multiple durability issues arose, primarily the structural collapse of the wick at temperature over short time periods. NTUU developed several methods of improving robustness of the wick2, but the resulting wick had limited performance capabilities. For application to CSP systems, the wick structures must retain high heat pipe performance with robustness for long term operation. In this paper we present our findings in developing an optimal balance between performance and ruggedness, including operation of a laboratory-scale heat pipe for over 5500 hours so far. Application of heat pipes to dish-Stirling systems has been shown to increase performance as much as 20%3, and application to supercritical CO2 systems has been proposed.

  9. Laser rapid forming technology of high-performance dense metal components with complex structure

    Science.gov (United States)

    Huang, Weidong; Chen, Jing; Li, Yanming; Lin, Xin

    2005-01-01

    Laser rapid forming (LRF) is a new and advanced manufacturing technology that has been developed on the basis of combining high power laser cladding technology with rapid prototyping (RP) to realize net shape forming of high performance dense metal components without dies. Recently we have developed a set of LRF equipment. LRF experiments were carried out on the equipment to investigate the influences of processing parameters on forming characterizations systematically with the cladding powder materials as titanium alloys, superalloys, stainless steel, and copper alloys. The microstructure of laser formed components is made up of columnar grains or columnar dendrites which grow epitaxially from the substrate since the solid components were prepared layer by layer additionally. The result of mechanical testing proved that the mechanical properties of laser formed samples are similar to or even over that of forging and much better than that of casting. It is shown in this paper that LRF technology is providing a new solution for some difficult processing problems in the high tech field of aviation, spaceflight and automobile industries.

  10. High performance {Omega}-gated Ge nanowire MOSFET with quasi-metallic source/drain contacts

    Energy Technology Data Exchange (ETDEWEB)

    Burchhart, T; Zeiner, C; Hyun, Y J; Lugstein, A; Hochleitner, G; Bertagnolli, E, E-mail: alois.lugstein@tuwien.ac.at [Institute for Solid State Electronics, Vienna University of Technology, Floragasse 7, A-1040 Vienna (Austria)

    2010-10-29

    Ge nanowires (NWs) about 2 {mu}m long and 35 nm in diameter are grown heteroepitaxially on Si(111) substrates in a hot wall low-pressure chemical vapor deposition (LP-CVD) system using Au as a catalyst and GeH{sub 4} as precursor. Individual NWs are contacted to Cu pads via e-beam lithography, thermal evaporation and lift-off techniques. Self-aligned and atomically sharp quasi-metallic copper-germanide source/drain contacts are achieved by a thermal activated phase formation process. The Cu{sub 3}Ge segments emerge from the Cu contact pads through axial diffusion of Cu which was controlled in situ by SEM, thus the active channel length of the MOSFET is adjusted without any restrictions from a lithographic process. Finally the conductivity of the channel is enhanced by Ga{sup +} implantation leading to a high performance {Omega}-gated Ge-NW MOSFET with saturation currents of a few microamperes.

  11. Leading research on super metal. 3. Amorphous and nanostructured metallic materials; Super metal no sendo kenkyu. 3. Kogata buzai

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Very fine structure control technique for amorphous and nanostructured metallic materials was reviewed to exceed the marginal performance of small metallic member materials. In Japan, high strength alloys and anticorrosion alloys are currently developed as an amorphous structure control technique, and ultra fine powder production and nano-compaction molding are studied for nanostructured materials. Fabrication of amorphous alloy wire materials and metal glass in USA are also introduced. Fabrication of metallic nanocrystals deposited within gas phase in Germany are attracting attention. The strength and abrasion resistance are remarkably enhanced by making nanostructured crystals and dispersing them. It may be most suitable to utilize amorphous and nanostructured metallic materials for earth-friendly materials having anticorrosion, and catalyst and biomaterial affinities, and also for magnetic materials. It is important for controlling micro-structures to clarify the formation mechanism of structures. For their processing techniques, the diversity and possibility are suggested, as to the condensation and solidification of gaseous and liquid phase metals, the molding and processing of very fine solid phase alloys, and the manufacturing members by heat treatment. 324 refs., 109 figs., 21 tabs.

  12. High performance nickel-metal hydride and lithium-ion batteries

    Science.gov (United States)

    Köhler, U.; Kümpers, J.; Ullrich, M.

    In comparison to pure electric vehicles (EV) the opportunities for hybrid electric vehicles (HEV) are much better, since range restrictions no longer apply and the interaction of the internal combustion engine and electrical drive bring increased energy efficiency and environmental friendliness. The batteries used in such applications must meet very high standards in terms of performance and service life. Although the battery capacity is smaller than for a purely EV, it needs to be able to generate far higher levels of power. The technical challenges of hybrid applications have led to the development of high-performance batteries. At the forefront of these is the nickel-metal hydride system (NiMH). With specific power and energy data in the range from 300 to 900 W/kg, 55 to 37 Wh/kg, respectively (based on cell weight), excellent charge efficiency and energy throughput levels of more than 10,000 times the nominal energy, the NiMH system comes very close to satisfying the needs of the HEV. Parallel developments with the lithium-ion system based on manganese spinel as cathode material show that, with specific power and energy levels above 1000 W/kg, 50 Wh/kg, respectively, this technology will also be able to play an important role in the future. Service life figures in terms of calendar life have been improved tremendously to about three years, but there is still a need for further improvement in order to meet the specifications of car manufacturers. For this reason, an increase of life span is the subject of intensive development work.

  13. A high-performance "sweeper" for toxic cationic herbicides: an anionic metal-organic framework with a tetrapodal cage.

    Science.gov (United States)

    Jia, Yan-Yuan; Zhang, Ying-Hui; Xu, Jian; Feng, Rui; Zhang, Ming-Shi; Bu, Xian-He

    2015-12-21

    This communication reports a novel metal-organic framework exhibiting an excellent performance in adsorbing small toxic cationic herbicides, i.e. methyl viologen and diquat, with large adsorption capacities and ultratrace residue levels. To the best of our knowledge, this is the first example of high-performance MOFs trapping toxic cationic herbicides. PMID:26468513

  14. Ion bombardment of Fe-based amorphous metallic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Miglierini, Marcel, E-mail: marcel.miglierini@stuba.sk [Slovak University of Technology, Department of Nuclear Physics and Technology (Slovakia); Lancok, Adriana [AS CR, v. v. i., Institute of Physics (Czech Republic); Pavlovic, Marius [Slovak University of Technology, Department of Nuclear Physics and Technology (Slovakia)

    2009-02-15

    Fe{sub 74}Cu{sub 1}Nb{sub 3}Si{sub 16}B{sub 6} amorphous metallic alloy is investigated after ion irradiation by 110 keV N{sup +} and 593 MeV Au ions. The depth-profiles of the radiation damage were calculated by the SRIM2008 code. Applicability of transmission and conversion electron Moessbauer effect measurements to distinguish between the bulk and surface radiation damage is demonstrated by using different irradiation conditions. The investigated alloy is characterized by ferromagnetic interactions. The implantation does not depict appreciable changes of the samples' surfaces. Changes in chemical short-range order (SRO) are revealed in N{sup +} irradiated alloys. Heavy Au ions caused pronounced effects in the position of the net magnetization though no impact on SRO was observed. After annealing, structural relaxation and annealing-out of the irradiation-induced stresses caused the rotation of the net magnetization back to its original position.

  15. Crystallization of amorphous silicon thin films deposited by PECVD on nickel-metalized porous silicon

    OpenAIRE

    Ben Slama, Sonia; Hajji, Messaoud; Ezzaouia, Hatem

    2012-01-01

    Porous silicon layers were elaborated by electrochemical etching of heavily doped p-type silicon substrates. Metallization of porous silicon was carried out by immersion of substrates in diluted aqueous solution of nickel. Amorphous silicon thin films were deposited by plasma-enhanced chemical vapor deposition on metalized porous layers. Deposited amorphous thin films were crystallized under vacuum at 750°C. Obtained results from structural, optical, and electrical characterizations show that...

  16. Structural modulation of lithium metal-electrolyte interface with three-dimensional metallic interlayer for high-performance lithium metal batteries

    Science.gov (United States)

    Lee, Hongkyung; Song, Jongchan; Kim, Yun-Jung; Park, Jung-Ki; Kim, Hee-Tak

    2016-01-01

    The use of lithium (Li) metal anodes has been reconsidered because of the necessity for a higher energy density in secondary batteries. However, Li metal anodes suffer from ‘dead’ Li formation and surface deactivation which consequently form a porous layer of redundant Li aggregates. In this work, a fibrous metal felt (FMF) as a three-dimensional conductive interlayer was introduced between the separator and the Li metal anode to improve the reversibility of the Li metal anode. The FMF can facilitate charge transfer in the porous layer, rendering it electrochemically more active. In addition, the FMF acted as a robust scaffold to accommodate Li deposits compactly in its interstitial sites. The FMF-integrated Li metal (FMF/Li) electrode operated with a small polarisation even at a current density of 10 mA cm−2, and it exhibited a seven times longer cycle-life than that of an FMF-free Li electrode in a symmetric cell configuration. A Li metal battery (LMB) using the FMF/Li electrode and a LiFePO4 electrode exhibited a two-fold increase in cycling stability compared with that of a bare Li metal electrode, demonstrating the practical effectiveness of this approach for high performance LMBs. PMID:27484160

  17. Structural modulation of lithium metal-electrolyte interface with three-dimensional metallic interlayer for high-performance lithium metal batteries

    Science.gov (United States)

    Lee, Hongkyung; Song, Jongchan; Kim, Yun-Jung; Park, Jung-Ki; Kim, Hee-Tak

    2016-08-01

    The use of lithium (Li) metal anodes has been reconsidered because of the necessity for a higher energy density in secondary batteries. However, Li metal anodes suffer from ‘dead’ Li formation and surface deactivation which consequently form a porous layer of redundant Li aggregates. In this work, a fibrous metal felt (FMF) as a three-dimensional conductive interlayer was introduced between the separator and the Li metal anode to improve the reversibility of the Li metal anode. The FMF can facilitate charge transfer in the porous layer, rendering it electrochemically more active. In addition, the FMF acted as a robust scaffold to accommodate Li deposits compactly in its interstitial sites. The FMF-integrated Li metal (FMF/Li) electrode operated with a small polarisation even at a current density of 10 mA cm‑2, and it exhibited a seven times longer cycle-life than that of an FMF-free Li electrode in a symmetric cell configuration. A Li metal battery (LMB) using the FMF/Li electrode and a LiFePO4 electrode exhibited a two-fold increase in cycling stability compared with that of a bare Li metal electrode, demonstrating the practical effectiveness of this approach for high performance LMBs.

  18. Break-down of Losses in High Performing Metal-Supported Solid Oxide Fuel Cells

    OpenAIRE

    Kromp, Alexander; Nielsen, Jimmi; Blennow Tullmar, Peter; Klemensø, Trine; Weber, André

    2012-01-01

    Metal supported SOFC designs offer competitive advantages such as reduced material costs and improved mechanical robustness. On the other hand, disadvantages might arise due to possible corrosion of the porous metal parts during processing and operation at high fuel utilization. In this paper we present the results of performance and stability improvements for a metal supported cell developed within the European project METSOFC and the Danish National Advanced Technology Foundation. The cells...

  19. High performance, high durability non-precious metal fuel cell catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Thomas E.; Atanasoski, Radoslav; Schmoeckel, Alison K.

    2016-03-15

    This invention relates to non-precious metal fuel cell cathode catalysts, fuel cells that contain these catalysts, and methods of making the same. The fuel cell cathode catalysts are highly nitrogenated carbon materials that can contain a transition metal. The highly nitrogenated carbon materials can be supported on a nanoparticle substrate.

  20. Break-down of Losses in High Performing Metal-Supported Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Kromp, Alexander; Nielsen, Jimmi; Blennow Tullmar, Peter;

    2012-01-01

    Metal supported SOFC designs offer competitive advantages such as reduced material costs and improved mechanical robustness. On the other hand, disadvantages might arise due to possible corrosion of the porous metal parts during processing and operation at high fuel utilization. In this paper we...

  1. Three-dimensional graphene/metal oxide nanoparticle hybrids for high-performance capacitive deionization of saline water.

    Science.gov (United States)

    Yin, Huajie; Zhao, Shenlong; Wan, Jiawei; Tang, Hongjie; Chang, Lin; He, Liangcan; Zhao, Huijun; Gao, Yan; Tang, Zhiyong

    2013-11-20

    A novel and general method is proposed to construct three-dimensional graphene/metal oxide nanoparticle hybrids. For the first time, it is demonstrated that this graphene-based composite with open pore structures can be used as the high-performance capacitive deionization (CDI) electrode materials, which outperform currently reported materials. This work will offer a promising way to develop highly effective CDI electrode materials. PMID:23963808

  2. Amorphous semiconducting and conducting transparent metal oxide thin films and production thereof

    Science.gov (United States)

    Perkins, John; Van Hest, Marinus Franciscus Antonius Maria; Ginley, David; Taylor, Matthew; Neuman, George A.; Luten, Henry A.; Forgette, Jeffrey A.; Anderson, John S.

    2010-07-13

    Metal oxide thin films and production thereof are disclosed. An exemplary method of producing a metal oxide thin film may comprise introducing at least two metallic elements and oxygen into a process chamber to form a metal oxide. The method may also comprise depositing the metal oxide on a substrate in the process chamber. The method may also comprise simultaneously controlling a ratio of the at least two metallic elements and a stoichiometry of the oxygen during deposition. Exemplary amorphous metal oxide thin films produced according to the methods herein may exhibit highly transparent properties, highly conductive properties, and/or other opto-electronic properties.

  3. Structural changes in amorphous metals from high-strain plastic deformation

    Energy Technology Data Exchange (ETDEWEB)

    Arora, Harpreet Singh [Department of Materials Science and Engineering, University of North Texas, Denton, TX 76203 (United States); Grewal, Harpreet Singh [School of Mechanical, Materials and Energy Engineering, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001 (India); Mridha, Sanghita [Department of Materials Science and Engineering, University of North Texas, Denton, TX 76203 (United States); Singh, Harpreet [School of Mechanical, Materials and Energy Engineering, Indian Institute of Technology Ropar, Rupnagar, Punjab 140001 (India); Mukherjee, Sundeep, E-mail: sundeep.mukherjee@unt.edu [Department of Materials Science and Engineering, University of North Texas, Denton, TX 76203 (United States)

    2014-11-03

    Structural changes in a bulk metallic glass subjected to high-strain plastic deformation was investigated. A zirconium-based bulk metallic glass was friction stir processed at different tool rotational speeds. The alloy retained its fully amorphous structure at lower speed. At higher tool rotational speed there was partial nano-crystallization with nearly three times increase in surface hardness. Changes in the glass transition temperature, relaxation and crystallization enthalpies were analyzed to explain the physics of high-strain deformation in amorphous metals.

  4. Atomic simulation on evolution of nano-crystallizaion in amorphous metals

    Institute of Scientific and Technical Information of China (English)

    WANG Yu; WANG Xiu-xi; WANG Hai-long

    2006-01-01

    The deformation-induced nano-crystallization behavior of amorphous pure Ni was investigated by using a molecular dynamics simulation. The microevolution mechanism of the nano-crystallization,the crystallization process in the multicomponent amorphous Ni-Pd alloys and the temperature effect on the nano-crystallization behavior in amorphous metals were studied. The results show that the small nano-crystalline grain will nucleate and grow during the compression deformation. The deformation induces the growth of the ordered clusters in the amorphous metals and the nano-crystalline grain grows under the shearing combination and shearing deposition. The nano-crystalline grain will nucleate in a lower strain under a higher temperature. The combining severe plastic deformation with thermal annealing treatments presents a new opportunity for developing bulk nano-crystalline materials with controlled microstructures.

  5. A novel biomimetic approach to the design of high-performance ceramic/metal composites

    Energy Technology Data Exchange (ETDEWEB)

    Launey, Maximilien E.; Munch, Etienne; Alsem, Daan Hein; Saiz, Eduardo; Tomsia, Antoni P.; Ritchie, Robert O.

    2009-08-01

    The prospect of extending natural biological design to develop new synthetic ceramic-metal composite materials is examined. Using ice-templating of ceramic suspensions and subsequent metal infiltration, we demonstrate that the concept of ordered hierarchical design can be applied to create fine-scale laminated ceramic-metal (bulk) composites that are inexpensive, lightweight and display exceptional damage-tolerance properties. Specifically, Al{sub 2}O{sub 3}/Al-Si laminates with ceramic contents up to approximately 40 vol% and with lamellae thicknesses down to 10 {micro}m were processed and characterized. These structures achieve an excellent fracture toughness of 40 MPa{radical}m at a tensile strength of approximately 300 MPa. Salient toughening mechanisms are described together with further toughening strategies.

  6. Role of Metal Contacts in High-Performance Phototransistors Based on WSe 2 Monolayers

    KAUST Repository

    Zhang, Wenjing

    2014-08-26

    Phototransistors based on monolayer transition metal dichalcogenides (TMD) have high photosensitivity due to their direct band gap transition. However, there is a lack of understanding of the effect of metal contacts on the performance of atomically thin TMD phototransistors. Here, we fabricate phototransistors based on large-area chemical vapor deposition (CVD) tungsten diselenide (WSe2) monolayers contacted with the metals of different work function values. We found that the low Schottky-contact WSe2 phototransistors exhibit a very high photo gain (105) and specific detectivity (1014Jones), values higher than commercial Si- and InGaAs-based photodetectors; however, the response speed is longer than 5 s in ambient air. In contrast, the high Schottky-contact phototransistors display a fast response time shorter than 23 ms, but the photo gain and specific detectivity decrease by several orders of magnitude. Moreover, the fast response speed of the high Schottky-contact devices is maintained for a few months in ambient air. This study demonstrates that the contact plays an important role in TMD phototransistors, and barrier height tuning is critical for optimizing the photoresponse and photoresponsivity. © 2014 American Chemical Society.

  7. Electrochemically formed ultrafine metal oxide nanocatalysts for high performance lithium-oxygen batteries

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bin; Yan, Pengfei; Xu, Wu; Zheng, Jianming; He, Yang; Luo, Langli; Bowden, Mark E.; Wang, Chong M.; Zhang, Jiguang

    2016-07-05

    Lithium-oxygen (Li-O2) battery has an extremely high theoretical specific energy density as compared with conventional energy storage systems. However, practical application of Li-O2 battery system still faces significant challenges, especially its poor cyclability. In this work, we report a new approach to synthesis ultrafine metal oxide nanocatalysts through an electrochemical pre-lithiation process. This process reduces the size of NiCo2O4 (NCO) particles from 20~30 nm to a uniformly distributed domain of ~ 2 nm and largely improved their catalytic activity. Structurally, the pre-lithiated NCO NWs are featured by ultrafine NiO/CoO nanoparticles, which show high stability during prolonged cycles in terms of morphology and the particle size, therefore maintaining an excellent catalytic effect to oxygen reduction and evolution reactions. Li-O2 battery using this catalyst has demonstrated an initial capacity of 29,280 mAh g-1 and has retained a stable capacity of over 1,000 mAh g-1 after 100 cycles based on the weight of NCO active material. Direct in-situ TEM observation conclusively reveals the lithiation/delithiation process of as-prepared NCO NWs, clarifying the NCO/Li electrochemical reaction mechanism that can be extended to other transition-metal oxides and providing the in depth understandings on the catalysts and battery chemistries of other ternary transition-metal oxides.

  8. Metal-dielectric frequency-selective surface for high performance solar window coatings

    Science.gov (United States)

    Toor, Fatima; Guneratne, Ananda C.; Temchenko, Marina

    2016-03-01

    We demonstrate a solar control window film consisting of metallic nanoantennas designed to reflect infrared (IR) light while allowing visible light to pass through. The film consists of a capacitive frequency-selective surface (CFSS) which acts as a band-stop filter, reflecting only light at target wavelengths. The designed CFSS when installed on windows will lower air conditioning costs by reflecting undesired wavelengths of light and thus reduce the amount of heat that enters a building. State-of-the-art commercial solar control films consist of a multilayer stack which is costly ( 13/m2 to 40/m2) to manufacture and absorbs IR radiation, causing delamination or glass breakage when attached to windows. Our solar control film consists of a nanostructured metallic layer on a polyethylene terephthalate (PET) substrate that reflects IR radiation instead of absorbing it, solving the delamination problem. The CFSS is also easy to manufacture with roll-to-roll nanoimprint lithography at a cost of components of the metallic nanoantenna. Our design achieves peak reflection of 80% at 1000 nm and has a broadband IR response that will allow for optimum solar control without significantly affecting the transmission of visible light.

  9. Synthesis of high performance ceramic fibers by chemical vapor deposition for advanced metallics reinforcing

    Science.gov (United States)

    Revankar, Vithal; Hlavacek, Vladimir

    1991-01-01

    The chemical vapor deposition (CVD) synthesis of fibers capable of effectively reinforcing intermetallic matrices at elevated temperatures which can be used for potential applications in high temperature composite materials is described. This process was used due to its advantage over other fiber synthesis processes. It is extremely important to produce these fibers with good reproducible and controlled growth rates. However, the complex interplay of mass and energy transfer, blended with the fluid dynamics makes this a formidable task. The design and development of CVD reactor assembly and system to synthesize TiB2, CrB, B4C, and TiC fibers was performed. Residual thermal analysis for estimating stresses arising form thermal expansion mismatch were determined. Various techniques to improve the mechanical properties were also performed. Various techniques for improving the fiber properties were elaborated. The crystal structure and its orientation for TiB2 fiber is discussed. An overall view of the CVD process to develop CrB2, TiB2, and other high performance ceramic fibers is presented.

  10. High Performance Transfer Press for Precision Manufacturing of Micro Metal Parts

    DEFF Research Database (Denmark)

    Mahshid, Rasoul

    on the above developed handling solution including a fully instrumented flexible tool for micro metal forming with the above mentioned characteristics. For this research, the 1050 Aluminum Alloy was used for forming material while it is originally in the form of coil. This original stock was sectioned...... for measuring the ovality of the sheared surfaces. An upsetting test was used to determine the flow stress curve of the material. Additionally, the initial condition of specimens were indicated for roughness and microstructure parameters. A transport device was manufactured which consisted of a linear motor...

  11. Wafer-Scale Monolayer Films of Semiconducting Metal Dichalcogenides for High-Performance Electronics

    Science.gov (United States)

    Xie, Saien; Kang, Kibum; Huang, Lujie; Han, Yimo; Huang, Pinshane; Mak, Kin Fai; Kim, Cheol-Joo; Muller, David; Park, Jiwoong

    2015-03-01

    Two-dimensional semiconducting transition metal dichalcogenides (TMDs) have shown their potential in electronics, optoelectronic and valleytronis. However, large-scale growth methods reported to date have only produced materials with limited structural and electrical uniformity, hindering further technological applications. Here we present a 4-inch scale growth of continuous monolayer molybdenum disulfide (MoS2) and tungsten disulfide (WS2) films that show excellent structural and electrical uniformity over the entire wafer using metal-organic chemical vapor deposition. The resulting monolayer films show high mobility of 30 cm2/Vs at room temperature, as well as the phonon-limited transport for MoS2, regardless of the channel length and device location. They allow for the batch fabrication of monolayer MoS2 field effect transistors with a 99% yield, which display spatially-uniform n-type transistor operation with a high on/off ratio. We further demonstrate the multi-level growth and fabrication of vertically-stacked monolayer MoS2 films and devices, which could enable the development of novel three-dimensional circuitry and device integration.

  12. High Performance Operation Control for Heat Driven Heat Pump System using Metal Hydride

    Science.gov (United States)

    Okamoto, Hideyuki; Masuda, Masao; Kozawa, Yoshiyuki

    lt is recognized that COP of heat driven heat pump system using metal hydride is 0.3-0.4 in general. In order to rise COP, we have proposed two kinds of specific operation control; the control of cycle change time according to cold heat load and the control of cooling water temperature according to outside air wet-bulb temperature. The characteristics of the heat pump system using metal hydride have grasped by various experiments and simulations. The validity of the simulation model has been confirmed by comparing with experimental results. As results of the simulations programmed for the actual operation control month by month, yearly COP has risen till 0.5-0.6 for practical scale air-conditioning system without regard for the building use. By the operation control hour by hour, yearly COP has risen till 0.6-0.65. Moreover, in the office building case added 40% sensible heat recovery, yearly COP has risen more than 0.8.

  13. Electrochemically Formed Ultrafine Metal Oxide Nanocatalysts for High-Performance Lithium-Oxygen Batteries.

    Science.gov (United States)

    Liu, Bin; Yan, Pengfei; Xu, Wu; Zheng, Jianming; He, Yang; Luo, Langli; Bowden, Mark E; Wang, Chong-Min; Zhang, Ji-Guang

    2016-08-10

    Lithium-oxygen (Li-O2) batteries have an extremely high theoretical specific energy density when compared with conventional energy-storage systems. However, practical application of the Li-O2 battery system still faces significant challenges. In this work, we report a new approach for synthesis of ultrafine metal oxide nanocatalysts through an electrochemical prelithiation process. This process reduces the size of NiCo2O4 (NCO) particles from 20-30 nm to a uniformly distributed domain of ∼2 nm and significantly improves their catalytic activity. Structurally, the prelithiated NCO nanowires feature ultrafine NiO/CoO nanoparticles that are highly stable during prolonged cycles in terms of morphology and particle size, thus maintaining an excellent catalytic effect to oxygen reduction and evolution reactions. A Li-O2 battery using this catalyst demonstrated an initial capacity of 29 280 mAh g(-1) and retained a capacity of >1000 mAh g(-1) after 100 cycles based on the weight of the NCO active material. Direct in situ transmission electron microscopy observations conclusively revealed the lithiation/delithiation process of as-prepared NCO nanowires and provided in-depth understanding for both catalyst and battery chemistries of transition-metal oxides. This unique electrochemical approach could also be used to form ultrafine nanoparticles of a broad range of materials for catalyst and other applications. PMID:27380300

  14. Amorphous mixed-metal hydroxide nanostructures for advanced water oxidation catalysts

    Science.gov (United States)

    Gao, Y. Q.; Liu, X. Y.; Yang, G. W.

    2016-02-01

    The design of highly efficient, durable, and earth-abundant catalysts for the oxygen evolution reaction (OER) is crucial in order to promote energy conversion and storage processes. Here, we synthesize amorphous mixed-metal (Ni-Fe) hydroxide nanostructures with a homogeneous distribution of Ni/Fe as well as a tunable Ni/Fe ratio by a simple, facile, green and low-cost electrochemical technique, and we demonstrate that the synthesized amorphous nanomaterials possess ultrahigh activity and super long-term cycle stability in the OER process. The amorphous Ni0.71Fe0.29(OH)x nanostructure affords a current density of 10 mA cm-2 at an overpotential of a mere 0.296 V and a small Tafel slope of 58 mV dec-1, while no deactivation is detected in the CV testing even up to 30 000 cycles, which suggests the promising application of these amorphous nanomaterials in electrochemical oxidation. Meanwhile, the distinct catalytic activities among these amorphous Ni-Fe hydroxide nanostructures prompts us to take notice of the composition of the alloy hydroxides/oxides when studying their catalytic properties, which opens an avenue for the rational design and controllable preparation of such amorphous nanomaterials as advanced OER electrocatalysts.The design of highly efficient, durable, and earth-abundant catalysts for the oxygen evolution reaction (OER) is crucial in order to promote energy conversion and storage processes. Here, we synthesize amorphous mixed-metal (Ni-Fe) hydroxide nanostructures with a homogeneous distribution of Ni/Fe as well as a tunable Ni/Fe ratio by a simple, facile, green and low-cost electrochemical technique, and we demonstrate that the synthesized amorphous nanomaterials possess ultrahigh activity and super long-term cycle stability in the OER process. The amorphous Ni0.71Fe0.29(OH)x nanostructure affords a current density of 10 mA cm-2 at an overpotential of a mere 0.296 V and a small Tafel slope of 58 mV dec-1, while no deactivation is detected in the CV

  15. Metal-organic framework nanoparticles decorated with graphene: A high-performance electromagnetic wave absorber

    Science.gov (United States)

    Wang, Yan; Zhang, Wenzhi; Wu, Xinming; Luo, Chunyan; Liang, Tan; Yan, Gang

    2016-10-01

    A novel metal organic framework (MOF) coated RGO was fabricated by a one-step method. The morphology and microstructure of MOF-53(Fe)/RGO composite were characterized by XRD and TEM. The electromagnetic parameters indicate that MOF-53(Fe)/RGO composite shows enhanced electromagnetic absorption properties compared with MOF-53(Fe). The maximum RL can reach -25.8 dB at 15.4 GHz and the absorption bandwidth with the reflection loss exceeding -10 dB is 5.9 GHz (from 12.1 to 18 GHz) with the thickness of 2 mm. The possible absorption mechanism was also investigated in detail. Our results indicate the potential application of MOF/RGO composite as a more efficient microwave absorber.

  16. Amorphous Metals for Opto-Mechanical Fixtures and Mechanisms Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The new JPL Metallurgy Facility is a small-scale foundry-type laboratory with capabilities for fabricating new metal alloys and metal-matrix-composites, casting...

  17. Impact Ignition and Combustion Behavior of Amorphous Metal-Based Reactive Composites

    Science.gov (United States)

    Mason, Benjamin; Groven, Lori; Son, Steven

    2013-06-01

    Recently published molecular dynamic simulations have shown that metal-based reactive powder composites consisting of at least one amorphous component could lead to improved reaction performance due to amorphous materials having a zero heat of fusion, in addition to having high energy densities and potential uses such as structural energetic materials and enhanced blast materials. In order to investigate the feasibility of these systems, thermochemical equilibrium calculations were performed on various amorphous metal/metalloid based reactive systems with an emphasis on commercially available or easily manufactured amorphous metals, such as Zr and Ti based amorphous alloys in combination with carbon, boron, and aluminum. Based on the calculations and material availability material combinations were chosen. Initial materials were either mixed via a Resodyn mixer or mechanically activated using high energy ball milling where the microstructure of the milled material was characterized using x-ray diffraction, optical microscopy and scanning electron microscopy. The mechanical impact response and combustion behavior of select reactive systems was characterized using the Asay shear impact experiment where impact ignition thresholds, ignition delays, combustion velocities, and temperatures were quantified, and reported. Funding from the Defense Threat Reduction Agency (DTRA), Grant Number HDTRA1-10-1-0119. Counter-WMD basic research program, Dr. Suhithi M. Peiris, program director is gratefully acknowledged.

  18. Bacterial adhesion on amorphous and crystalline metal oxide coatings

    Energy Technology Data Exchange (ETDEWEB)

    Almaguer-Flores, Argelia [Facultad de Odontología, División de Estudios de Posgrado e Investigación, Universidad Nacional Autónoma de México, Circuito exterior s/n, Ciudad Universitaria, 04510 México D.F. (Mexico); Silva-Bermudez, Phaedra, E-mail: suriel21@yahoo.com [Unidad de Ingeniería de Tejidos, Terapia Celular y Medicina Regenerativa, Instituto Nacional de Rehabilitación, Calzada México-Xochimilco No. 289, Col. Arenal de Guadalupe, 14389 México D.F. (Mexico); Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, 04510 México D.F. (Mexico); Galicia, Rey; Rodil, Sandra E. [Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, 04510 México D.F. (Mexico)

    2015-12-01

    Several studies have demonstrated the influence of surface properties (surface energy, composition and topography) of biocompatible materials on the adhesion of cells/bacteria on solid substrates; however, few have provided information about the effect of the atomic arrangement or crystallinity. Using magnetron sputtering deposition, we produced amorphous and crystalline TiO{sub 2} and ZrO{sub 2} coatings with controlled micro and nanoscale morphology. The effect of the structure on the physical–chemical surface properties was carefully analyzed. Then, we studied how these parameters affect the adhesion of Escherichia coli and Staphylococcus aureus. Our findings demonstrated that the nano-topography and the surface energy were significantly influenced by the coating structure. Bacterial adhesion at micro-rough (2.6 μm) surfaces was independent of the surface composition and structure, contrary to the observation in sub-micron (0.5 μm) rough surfaces, where the crystalline oxides (TiO{sub 2} > ZrO{sub 2}) surfaces exhibited higher numbers of attached bacteria. Particularly, crystalline TiO{sub 2}, which presented a predominant acidic nature, was more attractive for the adhesion of the negatively charged bacteria. The information provided by this study, where surface modifications are introduced by means of the deposition of amorphous or crystalline oxide coatings, offers a route for the rational design of implant surfaces to control or inhibit bacterial adhesion. - Highlights: • Amorphous (a) and crystalline (c) TiO{sub 2} and ZrO{sub 2} coatings were deposited. • The atomic ordering influences the coatings surface charge and nano-topography. • The atomic ordering modifies the bacterial adhesion for the same surface chemistry. • S. aureus adhesion was lower on a-TiO{sub 2} and a-ZrO{sub 2} than on their c-oxide counterpart. • E. coli adhesion on a-TiO{sub 2} was lower than on the c-TiO{sub 2}.

  19. Metal-based anode for high performance bioelectrochemical systems through photo-electrochemical interaction

    Science.gov (United States)

    Liang, Yuxiang; Feng, Huajun; Shen, Dongsheng; Long, Yuyang; Li, Na; Zhou, Yuyang; Ying, Xianbin; Gu, Yuan; Wang, Yanfeng

    2016-08-01

    This paper introduces a novel composite anode that uses light to enhance current generation and accelerate biofilm formation in bioelectrochemical systems. The composite anode is composed of 316L stainless steel substrate and a nanostructured α-Fe2O3 photocatalyst (PSS). The electrode properties, current generation, and biofilm properties of the anode are investigated. In terms of photocurrent, the optimal deposition and heat-treatment times are found to be 30 min and 2 min, respectively, which result in a maximum photocurrent of 0.6 A m-2. The start-up time of the PSS is 1.2 days and the maximum current density is 2.8 A m-2, twice and 25 times that of unmodified anode, respectively. The current density of the PSS remains stable during 20 days of illumination. Confocal laser scanning microscope images show that the PSS could benefit biofilm formation, while electrochemical impedance spectroscopy indicates that the PSS reduce the charge-transfer resistance of the anode. Our findings show that photo-electrochemical interaction is a promising way to enhance the biocompatibility of metal anodes for bioelectrochemical systems.

  20. Development of High-Performance Reflective Metal Insulation Through Optimized Sheet Plate Design

    Energy Technology Data Exchange (ETDEWEB)

    Eo, Min-hun; Lee, Sung-Myung; Jang, Kye-hwan; Kim, Won-Seok [BHI Co. Ltd., Haman (Korea, Republic of)

    2015-10-15

    Conservative insulation is especially difficult to apply to NPP facilities in consideration of operators' safety due to its characteristics of having unstable chemical and structural property, being easily degradable, and being able to produce harmful gases in the case of accidents and exposure to high temperature. Korean regulation organizations, together with the U.S., are considering the possibility of implementing a safety-enhanced technology of Reflective Metal Insulation (RMI) in order to solve safety problems such as sump clogging and ECC failure. RMI is made of stainless sheet plates with low emissivity and closed air spaces. The low emissivity in stainless steel blocks out thermal radiation, while the closed air spaces block out thermal conductivity and thermal convection. In this study, we made an analysis of the structure and shape of stainless sheet plates, the most important factor for the RMI design, by using Therm 7.3. Sheet plate design for maximizing insulating capacity of RMI was analyzed by Therm 7.3. The results are as follows: 1. In the case of an air layer with a thickness of 10mm or less, heat transfer by convection is completely blocked regardless of the heat flow direction. Therefore, when designing a sheet plate, heat transfer by radiation and heat conduction are the most important factors. 2. By minimizing the contact area between the stainless steel sheets, it is possible to minimize heat loss through conduction and, at the same time, maximize the radiation shielding effect in all areas. An increase in contact area causes a decrease in air gap, disallowing radiation shielding effect to take place.

  1. Creep strain recovery of Fe-Ni-B amorphous metallic ribbon

    NARCIS (Netherlands)

    Jurikova, Alena; Csach, Kornel; Miskuf, Jozef; Ocelik, Vaclav

    2007-01-01

    Creep strain recovery and structural relaxation of the amorphous metallic glass Fe40Ni41B19 after longtime loading at different annealing temperatures below the glass transition temperature have been studied using anisothermal differential scanning calorimetry (DSC) and dilatometry (TMA). It has bee

  2. Applications in the Nuclear Industry for Thermal Spray Amorphous Metal and Ceramic Coatings

    International Nuclear Information System (INIS)

    Amorphous metal and ceramic thermal spray coatings have been developed that can be used to enhance the corrosion resistance of containers for the transportation, aging and disposal of spent nuclear fuel and high-level radioactive wastes. Iron-based amorphous metal formulations with chromium, molybdenum and tungsten have shown the corrosion resistance believed to be necessary for such applications. Rare earth additions enable very low critical cooling rates to be achieved. The boron content of these materials, and their stability at high neutron doses, enable them to serve as high efficiency neutron absorbers for criticality control. Ceramic coatings may provide even greater corrosion resistance for container applications, though the boron-containing amorphous metals are still favored for criticality control applications. These amorphous metal and ceramic materials have been produced as gas atomized powders and applied as near full density, non-porous coatings with the high-velocity oxy-fuel process. This paper summarizes the performance of these coatings as corrosion-resistant barriers, and as neutron absorbers. Relevant corrosion models are also discussed, as well as a cost model to quantify the economic benefits possible with these new materials

  3. Amorphous mixed-metal hydroxide nanostructures for advanced water oxidation catalysts.

    Science.gov (United States)

    Gao, Y Q; Liu, X Y; Yang, G W

    2016-03-01

    The design of highly efficient, durable, and earth-abundant catalysts for the oxygen evolution reaction (OER) is crucial in order to promote energy conversion and storage processes. Here, we synthesize amorphous mixed-metal (Ni-Fe) hydroxide nanostructures with a homogeneous distribution of Ni/Fe as well as a tunable Ni/Fe ratio by a simple, facile, green and low-cost electrochemical technique, and we demonstrate that the synthesized amorphous nanomaterials possess ultrahigh activity and super long-term cycle stability in the OER process. The amorphous Ni0.71Fe0.29(OH)x nanostructure affords a current density of 10 mA cm(-2) at an overpotential of a mere 0.296 V and a small Tafel slope of 58 mV dec(-1), while no deactivation is detected in the CV testing even up to 30 000 cycles, which suggests the promising application of these amorphous nanomaterials in electrochemical oxidation. Meanwhile, the distinct catalytic activities among these amorphous Ni-Fe hydroxide nanostructures prompts us to take notice of the composition of the alloy hydroxides/oxides when studying their catalytic properties, which opens an avenue for the rational design and controllable preparation of such amorphous nanomaterials as advanced OER electrocatalysts. PMID:26864279

  4. Facile preparation of highly hydrophilic, recyclable high-performance polyimide adsorbents for the removal of heavy metal ions.

    Science.gov (United States)

    Huang, Jieyang; Zheng, Yaxin; Luo, Longbo; Feng, Yan; Zhang, Chaoliang; Wang, Xu; Liu, Xiangyang

    2016-04-01

    To obtain high-performance adsorbents that combine excellent adsorption ability, thermal stability, service life and recycling ability, polyimide (PI)/silica powders were prepared via a facile one-pot coprecipitation process. A benzimidazole unit was introduced into the PI backbone as the adsorption site. The benzimidazole unit induced more hydroxyls onto the silica, which provided hydrophilic sites for access by heavy metal ions. By comprehensively analyzing the effect of hydrophilcity, agglomeration, silica polycondensation, specific surface area and PI crystallinity, 10% was demonstrated to be the most proper feed silica content. The equilibrium adsorption amount (Qe) for Cu(2+) of PI/silica adsorbents was 77 times higher than that of pure PI. Hydrogen chloride (HCl) was used as a desorbent for heavy metal ions and could be decomplexed with benzimidazole unit at around 300°C, which was lower than the glass transition temperature of PI. The complexation and decomplexation process of HCl made PI/silica adsorbents recyclable, and the adsorption ability remained steady for more than 50 recycling processes. As PI/silica adsorbents possess excellent thermal stability, chemical resistance and radiation resistance and hydrophilicity, they have potential as superior recyclable adsorbents for collecting heavy metal ions from waste water in extreme environments. PMID:26736172

  5. Metallic and Insulating Interfaces of Amorphous SrTiO3-Based Oxide Heterostructures

    DEFF Research Database (Denmark)

    Chen, Yunzhong; Pryds, Nini; Kleibeuker, Josée E.;

    2011-01-01

    The conductance confined at the interface of complex oxide heterostructures provides new opportunities to explore nanoelectronic as well as nanoionic devices. Herein we show that metallic interfaces can be realized in SrTiO3-based heterostructures with various insulating overlayers of amorphous La......AlO3, SrTiO3, and yttria-stabilized zirconia films. On the other hand, samples of amorphous La7/8Sr1/8MnO3 films on SrTiO3 substrates remain insulating. The interfacial conductivity results from the formation of oxygen vacancies near the interface, suggesting that the redox reactions on the surface...

  6. 3D hybrid-porous carbon derived from carbonization of metal organic frameworks for high performance supercapacitors

    Science.gov (United States)

    Bao, Weizhai; Mondal, Anjon Kumar; Xu, Jing; Wang, Chengyin; Su, Dawei; Wang, Guoxiu

    2016-09-01

    We report a rational design and synthesis of 3D hybrid-porous carbon with a hierarchical pore architecture for high performance supercapacitors. It contains micropores (<2 nm diameter) and mesopores (2-4 nm), derived from carbonization of unique porous metal organic frameworks (MOFs). Owning to the synergistic effect of micropores and mesopores, the hybrid-porous carbon has exceptionally high ion-accessible surface area and low ion diffusion resistance, which is desired for supercapacitor applications. When applied as electrode materials in supercapacitors, 3D hybrid-porous carbon demonstrates a specific capacitance of 332 F g-1 at a constant charge/discharge current of 500 mA g-1. The supercapacitors can endure more than 10,000 cycles without degradation of capacitance.

  7. High-performance GaAs metal-insulator-semiconductor field-effect transistors enabled by self-assembled nanodielectrics

    Science.gov (United States)

    Lin, H. C.; Ye, P. D.; Xuan, Y.; Lu, G.; Facchetti, A.; Marks, T. J.

    2006-10-01

    High-performance GaAs metal-insulator-semiconductor field-effect-transistors (MISFETs) fabricated with very thin self-assembled organic nanodielectrics (SANDs), deposited from solution at room temperature, are demonstrated. A submicron gate-length depletion-mode n-channel GaAs MISFET with SAND thicknesses ranging from 5.5to16.5nm exhibit a gate leakage current density <10-5A/cm2 at a gate bias smaller than 3V, a maximum drain current of 370mA/mm at a forward gate bias of 2V, and a maximum intrinsic transconductance of 170mS/mm. The importance of appropriate GaAs surface chemistry treatments on SAND/GaAs interface properties is also presented. Application of SANDs to III-V compound semiconductors affords more opportunities to manipulate the complex III-V surface chemistry with broad materials options.

  8. Transition metal oxide window layer in thin film amorphous silicon solar cells

    International Nuclear Information System (INIS)

    Pin-type hydrogenated amorphous silicon solar cells have been fabricated by replacing state of the art silicon based window layer with more transparent transition metal oxide (TMO) materials. Three kinds of TMOs: vanadium oxide, tungsten oxide, and molybdenum oxide (MoOx) were comparatively investigated to reveal the design principles of metal oxide window layers. It was found that MoOx exhibited the best performance due to its higher work function property compared to other materials. In addition, the band alignment between MoOx and amorphous Si controls the series resistance, which was verified through compositional variation of MoOx thin films. The design principles of TMO window layer in amorphous Si solar cells are summarized as follows: A wide optical bandgap larger than 3.0 eV, a high work function larger than 5.2 eV, and a band alignment condition rendering efficient hole collection from amorphous Si absorber layer. - Highlights: • High work function metal oxides can potentially replace the conventional p-a-SiC. • V2Ox, WOx, and MoOx are comparatively investigated in this study. • MoOx is the most relevant material due to its highest work function. • Slightly oxygen deficient MoOx exhibited performance enhancement at x = 2.9

  9. High performance amorphous-Si@SiOx/C composite anode materials for Li-ion batteries derived from ball-milling and in situ carbonization

    Science.gov (United States)

    Wang, Dingsheng; Gao, Mingxia; Pan, Hongge; Wang, Junhua; Liu, Yongfeng

    2014-06-01

    Amorphous-Si@SiOx/C composites with amorphous Si particles as core and coated with a double layer of SiOx and carbon are prepared by ball-milling crystal micron-sized silicon powders and carbonization of the citric acid intruded in the ball-milled Si. Different ratios of Si to citric acid are used in order to optimize the electrochemical performance. It is found that SiOx exists naturally at the surfaces of raw Si particles and its content increases to ca. 24 wt.% after ball-milling. With an optimized Si to citric acid weight ratio of 1/2.5, corresponding to 8.4 wt.% C in the composite, a thin carbon layer is coated on the surfaces of a-Si@SiOx particles, moreover, floc-like carbon also forms and connects the carbon coated a-Si@SiOx particles. The composite provides a capacity of 1450 mA h g-1 after 100 cycles at a current density of 100 mA g1, and a capacity of 1230 mA h g-1 after 100 cycles at 500 mA g1 as anode material for lithium-ion batteries. Effects of ball-milling and the addition of citric acid on the microstructure and electrochemical properties of the composites are revealed and the mechanism of the improvement in electrochemical properties is discussed.

  10. Predicting catalyst-support interactions between metal nanoparticles and amorphous silica supports

    Science.gov (United States)

    Ewing, Christopher S.; Veser, Götz; McCarthy, Joseph J.; Lambrecht, Daniel S.; Johnson, J. Karl

    2016-10-01

    Metal-support interactions significantly affect the stability and activity of supported catalytic nanoparticles (NPs), yet there is no simple and reliable method for estimating NP-support interactions, especially for amorphous supports. We present an approach for rapid prediction of catalyst-support interactions between Pt NPs and amorphous silica supports for NPs of various sizes and shapes. We use density functional theory calculations of 13 atom Pt clusters on model amorphous silica supports to determine linear correlations relating catalyst properties to NP-support interactions. We show that these correlations can be combined with fast discrete element method simulations to predict adhesion energy and NP net charge for NPs of larger sizes and different shapes. Furthermore, we demonstrate that this approach can be successfully transferred to Pd, Au, Ni, and Fe NPs. This approach can be used to quickly screen stability and net charge transfer and leads to a better fundamental understanding of catalyst-support interactions.

  11. Improved Photo-Induced Stability in Amorphous Metal-Oxide Based TFTs for Transparent Displays.

    Science.gov (United States)

    Koo, Sang-Mo; Ha, Tae-Jun

    2015-10-01

    In this paper, we investigate the origin of photo-induced instability in amorphous metal-oxide based thin-film transistors (oxide-TFTs) by exploring threshold voltage (Vth) shift in transfer characteristics. The combination of photo irradiation and prolonged gate bias stress enhanced the shift in Vth in amorphous hafnium-indium-zinc-oxide (a-HfIZO) TFTs. Such results stem from the extended trapped charges at the localized defect states related to oxygen vacancy which play a role in a screening effect on the electric field induced by gate voltage. We also demonstrate the chemically clean interface in oxide-TFTs by employing oxygen annealing which reduces the density of trap states, thereby resulting in improved photo-induced stability. We believe that this work stimulates the research society of transparent electronics by providing a promising approach to suppress photo-induced instability in metal-oxide TFTs. PMID:26726416

  12. High-performance uncooled amorphous silicon video graphics array and extended graphics array infrared focal plane arrays with 17-μm pixel pitch

    Science.gov (United States)

    Tissot, Jean-Luc; Tinnes, Sébastien; Durand, Alain; Minassian, Christophe; Robert, Patrick; Vilain, Michel; Yon, Jean-Jacques

    2011-06-01

    The high level of accumulated expertise by ULIS and CEA/LETI on uncooled microbolometers made from amorphous silicon with 45, 35, and 25 μm enables ULIS to develop video graphics array (VGA) and extended graphics array (XGA) infrared focal plane array (IRFPA) formats with 17-μm pixel pitch to fulfill every application. These detectors keep all the recent innovations developed on the 25-μm pixel-pitch read out integrated circuit (ROIC) (detector configuration by serial link, low power consumption, and wide electrical dynamic range). The specific appeal of these units lies in the high spatial resolution it provides while keeping the small thermal time constant. The reduction of the pixel pitch turns the VGA array into a product well adapted for high-resolution and compact systems and the XGA a product well adapted for high-resolution imaging systems. High electro-optical performances have been demonstrated with noise equivalent temperature difference (NETD) ROIC design. This technology node paves the way to high-end products as well as low-end, compact, smaller formats, such as 320 × 240 and 160 × 120 or smaller.

  13. Roll-to-Roll Encapsulation of Metal Nanowires between Graphene and Plastic Substrate for High-Performance Flexible Transparent Electrodes.

    Science.gov (United States)

    Deng, Bing; Hsu, Po-Chun; Chen, Guanchu; Chandrashekar, B N; Liao, Lei; Ayitimuda, Zhawulie; Wu, Jinxiong; Guo, Yunfan; Lin, Li; Zhou, Yu; Aisijiang, Mahaya; Xie, Qin; Cui, Yi; Liu, Zhongfan; Peng, Hailin

    2015-06-10

    Transparent conductive film on plastic substrate is a critical component in low-cost, flexible, and lightweight optoelectronics. Industrial-scale manufacturing of high-performance transparent conductive flexible plastic is needed to enable wide-ranging applications. Here, we demonstrate a continuous roll-to-roll (R2R) production of transparent conductive flexible plastic based on a metal nanowire network fully encapsulated between graphene monolayer and plastic substrate. Large-area graphene film grown on Cu foil via a R2R chemical vapor deposition process was hot-laminated onto nanowires precoated EVA/PET film, followed by a R2R electrochemical delamination that preserves the Cu foil for reuse. The encapsulated structure minimized the resistance of both wire-to-wire junctions and graphene grain boundaries and strengthened adhesion of nanowires and graphene to plastic substrate, resulting in superior optoelectronic properties (sheet resistance of ∼8 Ω sq(-1) at 94% transmittance), remarkable corrosion resistance, and excellent mechanical flexibility. With these advantages, long-cycle life flexible electrochromic devices are demonstrated, showing up to 10000 cycles. PMID:26020567

  14. Carbonate-coordinated metal complexes precede the formation of liquid amorphous mineral emulsions of divalent metal carbonates†

    Science.gov (United States)

    Wolf, Stephan E.; Müller, Lars; Barrea, Raul; Kampf, Christopher J.; Leiterer, Jork; Panne, Ulrich; Hoffmann, Thorsten

    2011-01-01

    During the mineralisation of metal carbonates MCO3 (M = Ca, Sr, Ba, Mn, Cd, Pb) liquid-like amorphous intermediates emerge. These intermediates that form via a liquid/liquid phase separation behave like a classical emulsion and are stabilized electrostatically. The occurrence of these intermediates is attributed to the formation of highly hydrated networks whose stability is mainly based on weak interactions and the variability of the metal-containing pre-critical clusters. Their existence and compositional freedom are evidenced by electrospray ionization mass spectrometry (ESI-MS). Liquid intermediates in non-classical crystallisation pathways seem to be more common than assumed. PMID:21218241

  15. Characterization and Hydrodesulfurization Properties of Catalysts Derived from Amorphous Metal-boron Materials

    Energy Technology Data Exchange (ETDEWEB)

    Parks, Greg; Pease, Melissa; Layman, Kathryn A.; Burns, Autumn W.; Bussell, Mark E.; Wang, Xianqin; Hanson, Jonathan; Rodriguez, Jose A.

    2007-01-22

    Unsupported and silica-supported amorphous metal-boron materials (Ni-B, Mo-O-B, and Ni-Mo-O-B) were prepared by NaBH4 reduction of aqueous or impregnated metal salts. The resulting materials were characterized by a range of techniques, including conventional and time-resolved X-ray diffraction. The latter technique was used to determine the onset of crystallization of the amorphous materials during annealing in He flow and to identify the phases formed. Annealing of unsupported Ni-B resulted in the crystallization of predominantly Ni3B, followed by Ni metal, whereas Ni-B/SiO2 formed Ni and then NiO. There was no evidence for crystallization of B-containing phases for Mo-O-B or Mo-O-B/SiO2 on annealing; instead, the predominant phase formed was MoO2. In general, the phases formed for Ni-Mo-O-B and Ni-Mo-O-B/SiO2 were consistent with those formed in the monometallic materials, but at higher annealing temperatures. Catalysts prepared by sulfiding Ni-B/SiO2 and Ni-Mo-O-B/SiO2 materials had significantly higher thiophene HDS activities than conventionally prepared sulfided Ni/SiO2 and Ni-Mo/SiO2 catalysts, whereas a sulfided Mo-O-B/SiO2 catalyst had a dramatically lower HDS activity than a sulfided Mo/SiO2 catalyst.

  16. Amorphous metal-aluminophosphate catalysts for aldol condensation of n-heptanal and benzaldehyde to jasminaldehyde

    Institute of Scientific and Technical Information of China (English)

    A. Hamza; N. Nagaraju

    2015-01-01

    Amorphous aluminophosphate (AlP) and metal‐aluminophosphates (MAlPs, where M=2.5 mol%Cu, Zn, Cr, Fe, Ce, or Zr) were prepared by coprecipitation method. Their surface properties and catalytic activity for the synthesis of jasminaldehyde through the aldol condensation of n‐heptanal and benzaldehyde were investigated. The nitrogen adsorption‐desorption isotherms showed that the microporosity exhibited by the aluminophosphate was changed to a mesoporous and macroporous structure which depended on the metal incorporated, with a concomitant change in the surface area. Temperature‐programmed desorption of NH3 and CO2 revealed that the materials possessed both acidic and basic sites. The acidic strength of the material was either increased or decreased depending on the nature of the metal. The basicity was increased compared to AlP. All the materials were X‐ray amorphous and powder X‐ray diffraction studies indicated the absence of metal oxide phases. The Fourier transform infrared analysis confirmed the presence of phosphate groups and also the absence of any M‐O moieties in the materials. The selected organic reaction occurred only in the presence of the AlP and MAlPs. The selectivity for the jasminaldehyde product was up to 75%with a yield of 65%. The best conversion of n‐heptanal with a high selectivity to jasminaldehyde was obtained with FeAlP as the catalyst, and this material was characterized to have less weak acid sites and more basic sites.

  17. Electron field emission from 2-induced insulating to metallic behaviour of amorphous carbon (-C) films

    Indian Academy of Sciences (India)

    Pitamber Mahanandia; P N Viswakarma; Prasad Vishnu Bhotla; S V Subramanyam; Karuna Kar Nanda

    2010-06-01

    The influence of concentration and size of 2 cluster on the transport properties and electron field emissions of amorphous carbon films have been investigated. The observed insulating to metallic behaviour from reduced activation energy derived from transport measurement and threshold field for electron emission of -C films can be explained in terms of improvements in the connectivity between 2 clusters. The connectivity is resulted by the cluster concentration and size. The concentration and size of 2 content cluster is regulated by the coalescence of carbon globules into clusters, which evolves with deposition conditions.

  18. High-performance AlGaN metal-semiconductor-metal solar-blind ultraviolet photodetectors by localized surface plasmon enhancement

    Science.gov (United States)

    Zhang, Wei; Xu, Jin; Ye, Wei; Li, Yang; Qi, Zhiqiang; Dai, Jiangnan; Wu, Zhihao; Chen, Changqing; Yin, Jun; Li, Jing; Jiang, Hao; Fang, Yanyan

    2015-01-01

    AlGaN-based solar-blind ultraviolet photodetectors have attractive potential applications in the fields of missile plume detection, biochemical sensing, solar astronomy, etc. In this work, significant deep ultraviolet detection enhancement is demonstrated on AlGaN-based metal-semiconductor-metal (MSM) solar-blind ultraviolet photodetectors by introducing the coupling of localized surface plasmon from Al nanoparticles with the high-Al-content AlGaN epilayer. The size-controlled Al nanoparticle arrays fabricated by nanosphere lithography can not only reduce the detectors' dark current but also bring about greatly enhanced responsivity. The peak responsivity of AlGaN-based MSM solar-blind ultraviolet photodetectors with Al nanoparticles can reach 2.34 A/W at 269 nm under 20 V bias, enhanced more than 25 times than that without Al nanoparticles. Our approach shows an efficient fabrication technique of high-performance and low-cost plasmonic enhanced AlGaN solar-blind MSM ultraviolet photodetectors.

  19. Synchrotron radiation photoemission study of metal overlayers on hydrogenated amorphous silicon at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Pi, J.

    1990-09-21

    In this dissertation, metals deposited on a hydrogenated amorphous silicon (a-Si:H) film at room temperature are studied. The purpose of this work is mainly understanding the electronic properties of the interface, using high-resolution synchrotron radiation photoemission techniques as a probe. Atomic hydrogen plays an important role in passivating dangling bonds of a-Si:H films, thus reducing the gap-state distribution. In addition, singly bonded hydrogen also reduces states at the top of the valence band which are now replaced by deeper Si-H bonding states. The interface is formed by evaporating metal on an a-Si:H film in successive accumulations at room temperature. Au, Ag, and Cr were chosen as the deposited metals. Undoped films were used as substrates. Since some unique features can be found in a-Si:H, such as surface enrichment of hydrogen diffused from the bulk and instability of the free surface, we do not expect the metals/a-Si:H interface to behave exactly as its crystalline counterpart. Metal deposits, at low coverages, are found to gather preferentially around regions deficient in hydrogen. As the thickness is increased, some Si atoms in those regions are likely to leave their sites to intermix with metal overlayers like Au and Cr. 129 refs., 30 figs.

  20. Direct observation of small cluster mobility and ripening. [during annealing of metal films on amorphous substrates

    Science.gov (United States)

    Heinemann, K.; Poppa, H.

    1975-01-01

    Direct evidence is reported for the simultaneous occurrence of Ostwald ripening and short-distance cluster mobility during annealing of discontinuous metal films on clean amorphous substrates. The annealing characteristics of very thin particulate deposits of silver on amorphized clean surfaces of single crystalline thin graphite substrates were studied by in-situ transmission electron microscopy (TEM) under controlled environmental conditions (residual gas pressure of 10 to the minus 9th power torr) in the temperature range from 25 to 450 C. Sputter cleaning of the substrate surface, metal deposition, and annealing were monitored by TEM observation. Pseudostereographic presentation of micrographs in different annealing stages, the observation of the annealing behavior at cast shadow edges, and measurements with an electronic image analyzing system were employed to aid the visual perception and the analysis of changes in deposit structure recorded during annealing. Slow Ostwald ripening was found to occur in the entire temperature range, but the overriding surface transport mechanism was short-distance cluster mobility.

  1. Bulk Formation of Metallic Glasses and Amorphous Silicon from the Melt

    Science.gov (United States)

    Spaepen, F.

    1985-01-01

    By using metallic glass compositions with a high relative glass transition temperature, such as Pd40Ni40P20, homogeneous nucleation also becomes negligible. Large (5g) masses of this alloys were obtained using a molten B2O3 flux. Presently, bulk glass formation in iron based glasses is being investigated. It is expected that if an undercooling of about 250K can be achieved in a Ge or Si melt, formation of the amorphous semiconductor phase (rather than the crystal) may be kinetically favored. The volumetric behavior of undercooled liquid Ga droplet dispersion is investigated by dilatometry. A theoretical model (both analytical and numerical) was developed for transient nucleation in glass forming melts. The model, originally designed for isothermal conditions, was extended to continuous quenching. It is being applied to glass formation in various metallic and oxide systems. A further refinement will be the inclusion of diffusion controlled interfacial rearrangements governing the growth of the crystal embryos.

  2. An amorphous titanium dioxide metal insulator metal selector device for resistive random access memory crossbar arrays with tunable voltage margin

    Science.gov (United States)

    Cortese, Simone; Khiat, Ali; Carta, Daniela; Light, Mark E.; Prodromakis, Themistoklis

    2016-01-01

    Resistive random access memory (ReRAM) crossbar arrays have become one of the most promising candidates for next-generation non volatile memories. To become a mature technology, the sneak path current issue must be solved without compromising all the advantages that crossbars offer in terms of electrical performances and fabrication complexity. Here, we present a highly integrable access device based on nickel and sub-stoichiometric amorphous titanium dioxide (TiO2-x), in a metal insulator metal crossbar structure. The high voltage margin of 3 V, amongst the highest reported for monolayer selector devices, and the good current density of 104 A/cm2 make it suitable to sustain ReRAM read and write operations, effectively tackling sneak currents in crossbars without compromising fabrication complexity in a 1 Selector 1 Resistor (1S1R) architecture. Furthermore, the voltage margin is found to be tunable by an annealing step without affecting the device's characteristics.

  3. Carbonate-coordinated metal complexes precede the formation of liquid amorphous mineral emulsions of divalent metal carbonates

    Science.gov (United States)

    Wolf, Stephan E.; Müller, Lars; Barrea, Raul; Kampf, Christopher J.; Leiterer, Jork; Panne, Ulrich; Hoffmann, Thorsten; Emmerling, Franziska; Tremel, Wolfgang

    2011-03-01

    During the mineralisation of metal carbonates MCO3 (M = Ca, Sr, Ba, Mn, Cd, Pb) liquid-like amorphous intermediates emerge. These intermediates that form via a liquid/liquid phase separation behave like a classical emulsion and are stabilized electrostatically. The occurrence of these intermediates is attributed to the formation of highly hydrated networks whose stability is mainly based on weak interactions and the variability of the metal-containing pre-critical clusters. Their existence and compositional freedom are evidenced by electrospray ionization mass spectrometry (ESI-MS). Liquid intermediates in non-classical crystallisation pathways seem to be more common than assumed.During the mineralisation of metal carbonates MCO3 (M = Ca, Sr, Ba, Mn, Cd, Pb) liquid-like amorphous intermediates emerge. These intermediates that form via a liquid/liquid phase separation behave like a classical emulsion and are stabilized electrostatically. The occurrence of these intermediates is attributed to the formation of highly hydrated networks whose stability is mainly based on weak interactions and the variability of the metal-containing pre-critical clusters. Their existence and compositional freedom are evidenced by electrospray ionization mass spectrometry (ESI-MS). Liquid intermediates in non-classical crystallisation pathways seem to be more common than assumed. Electronic supplementary information (ESI) available: (S1 and S5) TEM at higher magnifications and of crystallizations conducted at pH = 6.0, 9.0 and 11.3; (S2) sketch of a spreading liquid particle on a TEM grid; (S3) wide-angle scattering of BaCO3 and CdCO3; (S4 and S6-S9) ESI-MS spectra of a solution of carbon dioxide and of bicarbonates of Sr, Ba, Pb, Mn and Cd. See DOI: 10.1039/c0nr00761g

  4. Research report of FY 1997 on the industrial science and technology development. Technology development of super-metal (technology development of nano-amorphous structural control materials); 1997 nendo sangyo kagaku gijutsu kenkyu kaihatsu Shin Energy Sangyo Gijutsu Sogo Kaihatsu Kiko itaku seika hokokusho. Super metal no gijutsu kaihatsu (nano-amorphous kozo seigyo zairyo no gijutsu kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    Research and development of the innovative metals have been conducted, by which the weight reduction of members can be done by drastically improving the strength compared with conventional metals. For the high-rate cluster deposition and super plastic forming technologies, research and development of aluminum-based light-weight materials have been conducted, which provides excellent strength, toughness, and super plastic formability at room temperature. For the high-density energy utilization and control technology (amorphous-A), super-metals have been investigated as high dew point and corrosion resistance materials used for waste incinerators operated under the very severe conditions. These are expected to be applied to the apparatuses and equipment due to their excellent properties. For the controlled cooling technology (amorphous-B), super-metals with excellent soft magnetic characteristics and degree of shape freedom have been investigated for high performance and high efficiency devices including electric/electronic/communication devices, power transmission devices, and various industrial devices and parts. These are expected to contribute to the creation of new markets and the improvement of international competitive force. 123 refs., 160 figs., 33 tabs.

  5. 3D hybrid-porous carbon derived from carbonization of metal organic frameworks for high performance supercapacitors

    Science.gov (United States)

    Bao, Weizhai; Mondal, Anjon Kumar; Xu, Jing; Wang, Chengyin; Su, Dawei; Wang, Guoxiu

    2016-09-01

    We report a rational design and synthesis of 3D hybrid-porous carbon with a hierarchical pore architecture for high performance supercapacitors. It contains micropores (3D hybrid-porous carbon demonstrates a specific capacitance of 332 F g-1 at a constant charge/discharge current of 500 mA g-1. The supercapacitors can endure more than 10,000 cycles without degradation of capacitance.

  6. Characterization and Hydrodesulfurization Properties of Catalysts Derived from Amorphous Metal-Boron Materials

    Energy Technology Data Exchange (ETDEWEB)

    Parks,G.; Pease, M.; Burns, A.; Layman, K.; Bussell, M.; Wang, X.; Hanson, J.; Rodriquez, J.

    2007-01-01

    Unsupported and silica-supported amorphous metal-boron materials (Ni-B, Mo-O-B, and Ni-Mo-O-B) were prepared by NaBH{sub 4} reduction of aqueous or impregnated metal salts. The resulting materials were characterized by a range of techniques, including conventional and time-resolved X-ray diffraction. The latter technique was used to determine the onset of crystallization of the amorphous materials during annealing in He flow and to identify the phases formed. Annealing of unsupported Ni-B resulted in the crystallization of predominantly Ni{sub 3}B, followed by Ni metal, whereas Ni-B/SiO{sub 2} formed Ni and then NiO. There was no evidence for crystallization of B-containing phases for Mo-O-B or Mo-O-B/SiO{sub 2} on annealing; instead, the predominant phase formed was MoO{sub 2}. In general, the phases formed for Ni-Mo-O-B and Ni-Mo-O-B/SiO2 were consistent with those formed in the monometallic materials, but at higher annealing temperatures. Catalysts prepared by sulfiding Ni-B/SiO{sub 2} and Ni-Mo-O-B/SiO{sub 2} materials had significantly higher thiophene HDS activities than conventionally prepared sulfided Ni/SiO2 and Ni-Mo/SiO{sub 2} catalysts, whereas a sulfided Mo-O-B/SiO{sub 2} catalyst had a dramatically lower HDS activity than a sulfided Mo/SiO{sub 2} catalyst.

  7. Electronic structure and conductivity of nanocomposite metal (Au,Ag,Cu,Mo)-containing amorphous carbon films

    Energy Technology Data Exchange (ETDEWEB)

    Endrino, Jose L.; Horwat, David; Gago, Raul; Andersson, Joakim; Liu, Y.S.; Guo, Jinghua; Anders, Andre

    2008-05-14

    In this work, we study the influence of the incorporation of different metals (Me = Au, Ag, Cu, Mo) on the electronic structure of amorphous carbon (a-C:Me) films. The films were produced at room temperature using a novel pulsed dual-cathode arc deposition technique. Compositional analysis was performed with secondary neutral mass spectroscopy whereas X-ray diffraction was used to identify the formation of metal nanoclusters in the carbon matrix. The metal content incorporated in the nanocomposite films induces a drastic increase in the conductivity, in parallel with a decrease in the band gap corrected from Urbach energy. The electronic structure as a function of the Me content has been monitored by x-ray absorption near edge structure (XANES) at the C K-edge. XANES showed that the C host matrix has a dominant graphitic character and that it is not affected significantly by the incorporation of metal impurities, except for the case of Mo, where the modifications in the lineshape spectra indicated the formation of a carbide phase. Subtle modifications of the spectral lineshape are discussed in terms of nanocomposite formation.

  8. Direct observation of microfracture process in metallic-continuous-fiber-reinforced amorphous matrix composites fabricated by liquid pressing process

    International Nuclear Information System (INIS)

    Zr-based amorphous matrix composites reinforced with metallic continuous fibers were fabricated by liquid pressing process, and their fracture property improvement was explained by directly observing microfracture processes. About 60 vol.% of metallic fibers were homogeneously distributed inside the amorphous matrix. Apparent fracture toughness of the tungsten-fiber-reinforced composites was lower than that of monolithic amorphous alloy, while that of the tantalum-fiber-reinforced composite was higher. According to the microfracture observation, shear bands or cracks were initiated at the amorphous matrix, and the propagation of the initiated shear bands or cracks was effectively blocked by fibers, thereby resulting in stable crack growth which could be confirmed by the fracture resistance curve (R-curve) behavior. This increase in fracture resistance with increasing crack length improved fracture properties of the fiber-reinforced composites, and could be explained by the formation of multiple shear bands or multiple cracks at the amorphous matrix, blocking of crack or shear band propagation, and multiple necking at metallic fibers.

  9. Photoelectron spectroscopy study of metallic nanocluster arrangement at the surface of reactively sputtered amorphous hydrogenated carbon

    International Nuclear Information System (INIS)

    We report on the results of the arrangement of isolated surface metallic nanoclusters embedded in amorphous hydrogenated carbon (a-C:H) thin films, studied by photoelectron spectroscopy. As a model system we used gold-containing amorphous hydrogenated carbon (a-C:H/Au), due to the lack of reactivity between carbon and gold. The a-C:H/Au samples are obtained by simultaneous magnetron sputtering of Au target by argon and plasma-enhanced chemical vapor deposition of methane. Photoelectron spectroscopy with x-ray and ultraviolet excitation has been employed for surface studies that comprise as-deposited sample spectra recordings, measurements at off-normal takeoff angle, in situ in-depth profiling by Ar+ ion etching, and thiophene adsorption at the sample surface. The results of these extended studies firmly support previously drawn conclusions [I. R. Videnovic, V. Thommen, P. Oelhafen, D. Mathys, M. Dueggelin, and R. Guggenheim, Appl. Phys. Lett 80, 2863 (2002)] that by deposition on electrically grounded substrates one obtains samples with topmost Au clusters covered with a thin layer of a-C:H. Introducing a dc substrate bias voltage results in bald Au clusters on the surface and increased sp2/sp3 coordinated carbon ratio in the a-C:H matrix

  10. Real-time Measurement of Biomagnetic Vector Fields in Functional Syncytium Using Amorphous Metal

    Science.gov (United States)

    Nakayama, Shinsuke; Uchiyama, Tusyoshi

    2015-03-01

    Magnetic field detection of biological electric activities would provide a non-invasive and aseptic estimate of the functional state of cellular organization, namely a syncytium constructed with cell-to-cell electric coupling. In this study, we investigated the properties of biomagnetic waves which occur spontaneously in gut musculature as a typical functional syncytium, by applying an amorphous metal-based gradio-magneto sensor operated at ambient temperature without a magnetic shield. The performance of differentiation was improved by using a single amorphous wire with a pair of transducer coils. Biomagnetic waves of up to several nT were recorded ~1 mm below the sample in a real-time manner. Tetraethyl ammonium (TEA) facilitated magnetic waves reflected electric activity in smooth muscle. The direction of magnetic waves altered depending on the relative angle of the muscle layer and magneto sensor, indicating the existence of propagating intercellular currents. The magnitude of magnetic waves rapidly decreased to ~30% by the initial and subsequent 1 mm separations between sample and sensor. The large distance effect was attributed to the feature of bioelectric circuits constructed by two reverse currents separated by a small distance. This study provides a method for detecting characteristic features of biomagnetic fields arising from a syncytial current.

  11. Visible-light-induced instability in amorphous metal-oxide based TFTs for transparent electronics

    Directory of Open Access Journals (Sweden)

    Tae-Jun Ha

    2014-10-01

    Full Text Available We investigate the origin of visible-light-induced instability in amorphous metal-oxide based thin film transistors (oxide-TFTs for transparent electronics by exploring the shift in threshold voltage (Vth. A large hysteresis window in amorphous indium-gallium-zinc-oxide (a-IGZO TFTs possessing large optical band-gap (≈3 eV was observed in a visible-light illuminated condition whereas no hysteresis window was shown in a dark measuring condition. We also report the instability caused by photo irradiation and prolonged gate bias stress in oxide-TFTs. Larger Vth shift was observed after photo-induced stress combined with a negative gate bias than the sum of that after only illumination stress and only negative gate bias stress. Such results can be explained by trapped charges at the interface of semiconductor/dielectric and/or in the gate dielectric which play a role in a screen effect on the electric field applied by gate voltage, for which we propose that the localized-states-assisted transitions by visible-light absorption can be responsible.

  12. A comparative study of the structure and crystallization of bulk metallic amorphous rod Pr60Ni30Al10 and melt-spun metallic amorphous ribbon Al87Ni10Pr3

    Institute of Scientific and Technical Information of China (English)

    Meng Qing-Ge; Li Jian-Guo; Zhou Jian-Kun

    2006-01-01

    Pr-based bulk metallic amorphous (BM1 rods (Pr60Ni30Al10) and Al-based amorphous ribbons (Al87Ni10Pr3)have been prepared by using copper mould casting and single roller melt-spun techniques, respectively. Thermal parameters deduced from differential scanning calorimeter (DS3 indicate that the glass-forming ability (GF1 of Pr60Nia0Al10 BMA rod is far higher than that of Al87Ni10Pr3 ribbon. A comparative study about the differences in structure between the two kinds of glass-forming alloys, superheated viscosity and crystallization are also made. Compared with the amorphous alloy Al87Ni10Pr3, the BMA alloy Pr60Ni30Al10 shows high thermal stability and large viscosity, small diffusivity at the same superheated temperatures. The results of x-Ray diffraction (XRD) and transmission electron microscope (TEM) show the pronounced difference in structure between the two amorphous alloys.Together with crystallization results, the main structure compositions of the amorphous samples are confirmed. It seems that the higher the GFA, the more topological type clusters in the Pr-Ni-Al amorphous alloys, the GFAs of the present glass-forming alloys are closely related to their structures.

  13. Three-terminal nanoelectromechanical switch based on tungsten nitride--an amorphous metallic material.

    Science.gov (United States)

    Mayet, Abdulilah M; Hussain, Aftab M; Hussain, Muhammad M

    2016-01-22

    Nanoelectromechanical (NEM) switches inherently have zero off-state leakage current and nearly ideal sub-threshold swing due to their mechanical nature of operation, in contrast to semiconductor switches. A challenge for NEM switches to be practical for low-power digital logic application is their relatively large operation voltage which can result in higher dynamic power consumption. Herein we report a three-terminal laterally actuated NEM switch fabricated with an amorphous metallic material: tungsten nitride (WNx). As-deposited WN x thin films have high Young's modulus (300 GPa) and reasonably high hardness (3 GPa), which are advantageous for high wear resistance. The first prototype WN x switches are demonstrated to operate with relatively low control voltage, down to 0.8 V for an air gap thickness of 150 nm. PMID:26636189

  14. A thermodynamic approach towards glass-forming ability of amorphous metallic alloys

    Indian Academy of Sciences (India)

    Sonal R Prajapati; Supriya Kasyap; Arun Pratap

    2015-12-01

    A quantitative measure of the stability of a glass as compared to its corresponding crystalline state can be obtained by calculating the thermodynamic parameters, such as the Gibbs free energy difference (), entropy difference () and the enthalpy difference () between the super-cooled liquid and the corresponding crystalline phase. is known as the driving force of crystallization. The driving force of crystallization () provides very important information about the glass-forming ability (GFA) of metallic glasses (MGs). Lesser the driving force of crystallization more is the GFA. The varies linearly with the critical size (). According to Battezzati and Garonne the parameter ( = (1−(/))/(1−( / ))) in the expression for should be a constant (i.e., 0.8), but its uniqueness is not observed for all MGs. The thermal stability of various alloy compositions is studied by their undercooled liquid region ( = − ). Large implies greater stability against crystallization of the amorphous structure. Other GFA parameters are also calculated and correlated with critical size ().

  15. Pressure-induced Transformations of Dense Carbonyl Sulfide to Singly Bonded Amorphous Metallic Solid

    Science.gov (United States)

    Kim, Minseob; Dias, Ranga; Ohishi, Yasuo; Matsuoka, Takehiro; Chen, Jing-Yin; Yoo, Choong-Shik

    2016-08-01

    The application of pressure, internal or external, transforms molecular solids into non-molecular extended network solids with diverse crystal structures and electronic properties. These transformations can be understood in terms of pressure-induced electron delocalization; however, the governing mechanisms are complex because of strong lattice strains, phase metastability and path dependent phase behaviors. Here, we present the pressure-induced transformations of linear OCS (R3m, Phase I) to bent OCS (Cm, Phase II) at 9 GPa an amorphous, one-dimensional (1D) polymer at 20 GPa (Phase III); and an extended 3D network above ~35 GPa (Phase IV) that metallizes at ~105 GPa. These results underscore the significance of long-range dipole interactions in dense OCS, leading to an extended molecular alloy that can be considered a chemical intermediate of its two end members, CO2 and CS2.

  16. Pressure-induced Transformations of Dense Carbonyl Sulfide to Singly Bonded Amorphous Metallic Solid.

    Science.gov (United States)

    Kim, Minseob; Dias, Ranga; Ohishi, Yasuo; Matsuoka, Takehiro; Chen, Jing-Yin; Yoo, Choong-Shik

    2016-01-01

    The application of pressure, internal or external, transforms molecular solids into non-molecular extended network solids with diverse crystal structures and electronic properties. These transformations can be understood in terms of pressure-induced electron delocalization; however, the governing mechanisms are complex because of strong lattice strains, phase metastability and path dependent phase behaviors. Here, we present the pressure-induced transformations of linear OCS (R3m, Phase I) to bent OCS (Cm, Phase II) at 9 GPa; an amorphous, one-dimensional (1D) polymer at 20 GPa (Phase III); and an extended 3D network above ~35 GPa (Phase IV) that metallizes at ~105 GPa. These results underscore the significance of long-range dipole interactions in dense OCS, leading to an extended molecular alloy that can be considered a chemical intermediate of its two end members, CO2 and CS2. PMID:27527241

  17. Influence of the microstructure on the corrosion behavior of magnetron sputter-quenched amorphous metallic alloys

    Science.gov (United States)

    Thakoor, A. P.; Khanna, S. K.; Williams, R. M.; Landel, R. F.

    1983-01-01

    The microstructure and corrosion behavior of magnetron sputter deposited amorphous metallic films of (Mo6ORu40)82B18 under varying sputtering atmospheres have been investigated. The microstructural details and topology of the films have been studied by scanning electron microscopy and correlated with the deposition conditions. By reducing the pressure of pure argon gas, the characteristic features of rough surface and columnar growth full of vertical voids can be converted into a mirror-smooth finish with very dense deposits. Films deposited in the presence of O2 or N2 exhibit columnar structure with vertical voids. Film deposited in pure argon at low pressure show remarkably high corrosion resistance due to the formation of a uniform passive surface layer. The influence of the microstructure and surface texture on the corrosion behavior is discussed.

  18. Three-terminal nanoelectromechanical switch based on tungsten nitride—an amorphous metallic material

    Science.gov (United States)

    Mayet, Abdulilah M.; Hussain, Aftab M.; Hussain, Muhammad M.

    2016-01-01

    Nanoelectromechanical (NEM) switches inherently have zero off-state leakage current and nearly ideal sub-threshold swing due to their mechanical nature of operation, in contrast to semiconductor switches. A challenge for NEM switches to be practical for low-power digital logic application is their relatively large operation voltage which can result in higher dynamic power consumption. Herein we report a three-terminal laterally actuated NEM switch fabricated with an amorphous metallic material: tungsten nitride (WN x ). As-deposited WN x thin films have high Young’s modulus (300 GPa) and reasonably high hardness (3 GPa), which are advantageous for high wear resistance. The first prototype WN x switches are demonstrated to operate with relatively low control voltage, down to 0.8 V for an air gap thickness of 150 nm.

  19. Three-terminal nanoelectromechanical switch based on tungsten nitride—an amorphous metallic material

    KAUST Repository

    Mayet, Abdulilah M.

    2015-12-04

    © 2016 IOP Publishing Ltd. Nanoelectromechanical (NEM) switches inherently have zero off-state leakage current and nearly ideal sub-threshold swing due to their mechanical nature of operation, in contrast to semiconductor switches. A challenge for NEM switches to be practical for low-power digital logic application is their relatively large operation voltage which can result in higher dynamic power consumption. Herein we report a three-terminal laterally actuated NEM switch fabricated with an amorphous metallic material: tungsten nitride (WNx). As-deposited WNx thin films have high Young\\'s modulus (300 GPa) and reasonably high hardness (3 GPa), which are advantageous for high wear resistance. The first prototype WNx switches are demonstrated to operate with relatively low control voltage, down to 0.8 V for an air gap thickness of 150 nm.

  20. Simultaneous determination of toxic heavy metals in metformin hydrochloride using reversed-phase high-performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Steenkamp, P.A. (Dept. of Chemistry and Biochemistry, Rand Afrikaans Univ., Auckland Park (South Africa)); Coetzee, P.P. (Dept. of Chemistry and Biochemistry, Rand Afrikaans Univ., Auckland Park (South Africa))

    1993-08-01

    A rapid and sensitive reversed phase HPLC technique was developed for the determination of seven toxic heavy metals in biological matrices. Cd, Pb, Ni, Co, Bi, Cu and Hg could be detected and quantified at ppb level in Metformin hydrochloride, a pharmaceutical product used in the treatment of certain cases of diabetes. This was achieved by the evaluation of the stability of NaDEDTC in the presence of water and different buffers at different pH-values. A direct injection/on-column derivatization HPLC procedure was developed employing NaDEDTC as chelating agent, a C-18 reversed phase analytical column and a photodiode assay detector. Dilute metal ion solutions could be analyzed by direct injection of the test sample. The analysis of trace levels of metals in a pure pharmaceutical product however required the inclusion of a sample preparation step prior to analysis. (orig.)

  1. General synthesis of vanadium-based mixed metal oxides hollow nanofibers for high performance lithium-ion batteries

    Science.gov (United States)

    Xiang, Juan; Yu, Xin-Yao; Paik, Ungyu

    2016-10-01

    Hollow nanostructured mixed metal oxides have recently been intensively investigated as electrode materials for energy storage and conversion due to their remarkable electrochemical properties. Although great efforts have been made, the synthesis of hollow nanostructured vanadium-based mixed metal oxides especially those with one dimensional structure is rarely reported. Vanadium-based mixed metal oxides are promising electrode materials for lithium-ion batteries with high capacity and good rate capability. Here, we develop a facile and general method for the synthesis of one dimensional MxV2O8 (M = Co, Ni, Fe) tubular structure through a simple single-spinneret electrospinning technique followed by a calcination process. As a demonstration, Co3V2O8 hollow nanofibers are evaluated as anode materials for lithium-ion batteries. As expected, benefiting from their unique one dimensional tubular structure, the as-synthesized Co3V2O8 exhibits excellent electrochemical properties for lithium storage. To be specific, it can deliver a high specific capacity of 900 mAh g-1 at 5 A g-1, and long cycling stability up to 2000 cycles. The present work makes a significant contribution to the design and synthesis of mixed metal oxides with one dimensional tubular structure, as well as their potential applications in electrochemical energy storage.

  2. Nitrogen-doped graphdiyne as a metal-free catalyst for high-performance oxygen reduction reactions

    Science.gov (United States)

    Liu, Rongji; Liu, Huibiao; Li, Yuliang; Yi, Yuanping; Shang, Xinke; Zhang, Shuangshuang; Yu, Xuelian; Zhang, Suojiang; Cao, Hongbin; Zhang, Guangjin

    2014-09-01

    Fuel cells and metal-air batteries will only become widely available in everyday life when the expensive platinum-based electrocatalysts used for the oxygen reduction reactions are replaced by other efficient, low-cost and stable catalysts. We report here the use of nitrogen-doped graphdiyne as a metal-free electrode with a comparable electrocatalytic activity to commercial Pt/C catalysts for the oxygen reduction reaction in alkaline fuel cells. Nitrogen-doped graphdiyne has a better stability and increased tolerance to the cross-over effect than conventional Pt/C catalysts.Fuel cells and metal-air batteries will only become widely available in everyday life when the expensive platinum-based electrocatalysts used for the oxygen reduction reactions are replaced by other efficient, low-cost and stable catalysts. We report here the use of nitrogen-doped graphdiyne as a metal-free electrode with a comparable electrocatalytic activity to commercial Pt/C catalysts for the oxygen reduction reaction in alkaline fuel cells. Nitrogen-doped graphdiyne has a better stability and increased tolerance to the cross-over effect than conventional Pt/C catalysts. Electronic supplementary information (ESI) available: Detailed RDE and RRDE experiments, additional tables and figures. See DOI: 10.1039/c4nr03185g

  3. Crackle template based metallic mesh with highly homogeneous light transmission for high-performance transparent EMI shielding

    OpenAIRE

    Yu Han; Jie Lin; Yuxuan Liu; Hao Fu; Yuan Ma; Peng Jin; Jiubin Tan

    2016-01-01

    Our daily electromagnetic environment is becoming increasingly complex with the rapid development of consumer electronics and wireless communication technologies, which in turn necessitates the development of electromagnetic interference (EMI) shielding, especially for transparent components. We engineered a transparent EMI shielding film with crack-template based metallic mesh (CT-MM) that shows highly homogeneous light transmission and strong microwave shielding efficacy. The CT-MM film is ...

  4. High Performance, Low Temperature Solution-Processed Barium and Strontium Doped Oxide Thin Film Transistors

    OpenAIRE

    Banger, Kulbinder K.; Peterson, Rebecca L.; Mori, Kiyotaka; Yamashita, Yoshihisa; Leedham, Timothy; Sirringhaus, Henning

    2013-01-01

    Amorphous mixed metal oxides are emerging as high performance semiconductors for thin film transistor (TFT) applications, with indium gallium zinc oxide, InGaZnO (IGZO), being one of the most widely studied and best performing systems. Here, we investigate alkaline earth (barium or strontium) doped InBa(Sr)ZnO as alternative, semiconducting channel layers and compare their performance of the electrical stress stability with IGZO. In films fabricated by solution-processing from metal alkoxide ...

  5. High performance ZnO nanowire field effect transistors with organic gate nanodielectrics: effects of metal contacts and ozone treatment

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Sanghyun [School of Electrical and Computer Engineering, and Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907 (United States); Lee, Kangho [School of Electrical and Computer Engineering, and Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907 (United States); Yoon, Myung-Han [Department of Chemistry and Materials Research Center, and Institute for Nanoelectronics and Computing, Northwestern University, Evanston, IL 60208-3113 (United States); Facchetti, Antonio [Department of Chemistry and Materials Research Center, and Institute for Nanoelectronics and Computing, Northwestern University, Evanston, IL 60208-3113 (United States); Marks, Tobin J [Department of Chemistry and Materials Research Center, and Institute for Nanoelectronics and Computing, Northwestern University, Evanston, IL 60208-3113 (United States); Janes, David B [School of Electrical and Computer Engineering, and Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907 (United States)

    2007-04-18

    High performance ZnO nanowire field effect transistors (NW-FETs) were fabricated using a nanoscopic self-assembled organic gate insulator and characterized in terms of conventional device performance metrics. To optimize device performance and understand the effects of interface properties, devices were fabricated with both Al and Au/Ti source/drain contacts, and device electrical properties were characterized following annealing and ozone treatment. Ozone-treated single ZnO NW-FETs with Al contacts exhibited an on-current (I{sub on}) of {approx}4 {mu}A at 0.9 V{sub gs} and 1.0 V{sub ds}, a threshold voltage (V{sub th}) of 0.2 V, a subthreshold slope (S) of {approx}130 mV/decade, an on-off current ratio (I{sub on}:I{sub off}) of {approx}10{sup 7}, and a field effect mobility ({mu}{sub eff}) of {approx}1175 cm{sup 2} V{sup -1} s{sup -1}. In addition, ozone-treated ZnO NW-FETs consistently retained the enhanced device performance metrics after SiO{sub 2} passivation. A 2D device simulation was performed to explain the enhanced device performance in terms of changes in interfacial trap and fixed charge densities.

  6. High performance ZnO nanowire field effect transistors with organic gate nanodielectrics: effects of metal contacts and ozone treatment

    Science.gov (United States)

    Ju, Sanghyun; Lee, Kangho; Yoon, Myung-Han; Facchetti, Antonio; Marks, Tobin J.; Janes, David B.

    2007-04-01

    High performance ZnO nanowire field effect transistors (NW-FETs) were fabricated using a nanoscopic self-assembled organic gate insulator and characterized in terms of conventional device performance metrics. To optimize device performance and understand the effects of interface properties, devices were fabricated with both Al and Au/Ti source/drain contacts, and device electrical properties were characterized following annealing and ozone treatment. Ozone-treated single ZnO NW-FETs with Al contacts exhibited an on-current (Ion) of ~4 µA at 0.9 Vgs and 1.0 Vds, a threshold voltage (Vth) of 0.2 V, a subthreshold slope (S) of ~130 mV/decade, an on-off current ratio (Ion:Ioff) of ~107, and a field effect mobility (μeff) of ~1175 cm2 V-1 s-1. In addition, ozone-treated ZnO NW-FETs consistently retained the enhanced device performance metrics after SiO2 passivation. A 2D device simulation was performed to explain the enhanced device performance in terms of changes in interfacial trap and fixed charge densities.

  7. High-performance zno transistors processed via an aqueous carbon-free metal oxide precursor route at temperatures between 80-180 °c

    KAUST Repository

    Lin, Yenhung

    2013-06-25

    An aqueous and carbon-free metal-oxide precursor route is used in combination with a UV irradiation-assisted low-temperature conversion method to fabricate low-voltage ZnO transistors with electron mobilities exceeding 10 cm2/Vs at temperatures <180°C. Because of its low temperature requirements the method allows processing of high-performance transistors onto temperature sensitive substrates such as plastic. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Recent progress in high performance and reliable n-type transition metal oxide-based thin film transistors

    International Nuclear Information System (INIS)

    This review gives an overview of the recent progress in vacuum-based n-type transition metal oxide (TMO) thin film transistors (TFTs). Several excellent review papers regarding metal oxide TFTs in terms of fundamental electron structure, device process and reliability have been published. In particular, the required field-effect mobility of TMO TFTs has been increasing rapidly to meet the demands of the ultra-high-resolution, large panel size and three dimensional visual effects as a megatrend of flat panel displays, such as liquid crystal displays, organic light emitting diodes and flexible displays. In this regard, the effects of the TMO composition on the performance of the resulting oxide TFTs has been reviewed, and classified into binary, ternary and quaternary composition systems. In addition, the new strategic approaches including zinc oxynitride materials, double channel structures, and composite structures have been proposed recently, and were not covered in detail in previous review papers. Special attention is given to the advanced device architecture of TMO TFTs, such as back-channel-etch and self-aligned coplanar structure, which is a key technology because of their advantages including low cost fabrication, high driving speed and unwanted visual artifact-free high quality imaging. The integration process and related issues, such as etching, post treatment, low ohmic contact and Cu interconnection, required for realizing these advanced architectures are also discussed. (invited review)

  9. Synthesis and electrochemical investigation of hollow hierarchical metal oxide microspheres for high performance lithium-ion batteries

    International Nuclear Information System (INIS)

    In this paper, a versatile facile route to synthesize mesoporous hollow-structured metal oxides is demonstrated using sulfonated polystyrene (SPS) microspheres as hard templates. SEM and TEM images show that the Fe2O3, Co3O4 and NiO hollow microspheres are self-assembled by nanorods, nanoparticles and nanosheets, respectively. Hollow and mesoporous structures not only provide enhanced mechanical stabilities to buffer the large volume changes during the charge/discharge processes, but also provide large specific areas for sufficient penetration of electrolyte, thus leading to an excellent cyclic stability and rate capability. As proofs-of-concepts, all of the hollow and mesoporous metal oxides (Fe2O3, Co3O4 and NiO) deliver high initial discharge capacities and good capacity retentions (>80%) after more than 100 cycles in half cells. Most important of all, these assembled full-cells (MxOy(M = Fe, Co, Ni)/LiCoO2) also delivere excellent electrochemical performances. This work clearly demonstrates that the MxOy(M = Fe, Co, Ni)/LiCoO2 configuration are promising alternative high power-density energy storage devices in the near future

  10. Crackle template based metallic mesh with highly homogeneous light transmission for high-performance transparent EMI shielding

    Science.gov (United States)

    Han, Yu; Lin, Jie; Liu, Yuxuan; Fu, Hao; Ma, Yuan; Jin, Peng; Tan, Jiubin

    2016-05-01

    Our daily electromagnetic environment is becoming increasingly complex with the rapid development of consumer electronics and wireless communication technologies, which in turn necessitates the development of electromagnetic interference (EMI) shielding, especially for transparent components. We engineered a transparent EMI shielding film with crack-template based metallic mesh (CT-MM) that shows highly homogeneous light transmission and strong microwave shielding efficacy. The CT-MM film is fabricated using a cost-effective lift-off method based on a crackle template. It achieves a shielding effectiveness of ~26 dB, optical transmittance of ~91% and negligible impact on optical imaging performance. Moreover, high–quality CT-MM film is demonstrated on a large–calibre spherical surface. These excellent properties of CT-MM film, together with its advantages of facile large-area fabrication and scalability in processing on multi-shaped substrates, make CT-MM a powerful technology for transparent EMI shielding in practical applications.

  11. Size exclusion and anion exchange high performance liquid chromatography for characterizing metals bound to marine dissolved organic matter

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Otero, Natalia; Bermejo-Barrera, Pilar [Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, University of Santiago de Compostela, Avenida das Ciencias, s/n, 15782 Santiago de Compostela (Spain); Moreda-Pineiro, Antonio, E-mail: antonio.moreda@usc.es [Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, University of Santiago de Compostela, Avenida das Ciencias, s/n, 15782 Santiago de Compostela (Spain)

    2013-01-14

    Highlights: Black-Right-Pointing-Pointer Fractionation methods for assessing metals bound to marine DOM were developed. Black-Right-Pointing-Pointer SEC and AEC with UV detection and hyphenated with inductively coupled plasma-mass spectrometry were used. Black-Right-Pointing-Pointer SEC-UV showed marine DOM of molecular weights from 16 to 1 kDa. Black-Right-Pointing-Pointer Cobalt, manganese, strontium and zinc are bound to marine DOM. - Abstract: Size exclusion chromatography (SEC) followed by anion exchange chromatography (AEC) hyphenated with inductively coupled plasma-mass spectrometry (ICP-MS) was applied for fractionating metals bound to marine dissolved organic matter (DOM). Surface seawater samples (100 L) were subjected to tangential flow ultrafiltration (10,000 Da cut off) for isolating and pre-concentrating dissolved large molecules. The isolated fraction (retentate) consisted of 1 L, which was further freeze-dried and re-dissolved to 250 mL with ultrapure water. After HI Trap desalting of the re-dissolved retentate, SEC with UV detection showed marine DOM ranging from 6.5 kDa (lower than the permeable volume of the SEC column) to 16 kDa. A further characterization of this fraction by AEC with UV detection revealed the existence of four groups of macromolecules exhibiting retention times of 2.3, 2.8, 4.5 and 14.0 min. AEC hyphenated with ICP-MS showed the presence of strontium and zinc in the first AE fraction isolated from the SEC fraction; while manganese was found to be bound to the second AE fraction. Cobalt was found to be bound to molecules comprising the third AE fraction.

  12. Improved manufacturing technology for producing porous Nafion for high-performance ionic polymer–metal composite actuators

    Science.gov (United States)

    Zhao, Dongxu; Li, Dichen; Wang, Yanjie; Chen, Hualing

    2016-07-01

    The current actuation performance of ionic polymer–metal composites (IPMCs) limits their further application in the aerospace, energy, and optics fields, among others. To overcome this issue, we developed a freeze-drying process to generate Nafion membranes with a porous structure, the characteristics of which were investigated using thermogravimetric analysis, Fourier transform infrared spectrometry, field-emission scanning electron microscopy, and water uptake tests. The pores fabricated using the developed freeze-drying process had a diameter of approximately 270 nm, and a porosity of nearly 40.45%. The displacement and the central angle were introduced as variables to evaluate the bending deformation of an IPMC actuator based on the porous Nafion membrane. Compared with conventional actuators, this IPMC actuator showed an increase in displacement of 4963.6% at 2 V, and an increase in central angle of 73.35% at 3 V. Although the blocking forces of this IPMC actuator decreased to some extent, it was confirmed that the integrated actuation performance, which was evaluated using the strain energy density increment, was improved. The performance of the IPMC actuator was enhanced as a result of the porous Nafion structure manufactured using the developed freeze-drying process.

  13. High-performance metal–semiconductor–metal UV photodetector based on spray deposited ZnO thin films

    International Nuclear Information System (INIS)

    Highlights: • ZnO based MSM UV photodetector by economical chemical spray pyrolysis technique. • Effect of substrate temperature on properties of ZnO based MSM UV photodetector. • Photoresponse mechanism by optical switching property of ZnO thin film photodetectors. - Abstract: Zinc oxide (ZnO) based metal–semiconductor–metal (MSM) ultraviolet photodetectors at different substrate temperatures were fabricated on glass substrates by economical chemical spray pyrolysis technique and its UV photoresponsivity was measured at room temperature. The samples were characterized with respect to their structural, morphological, and optical properties using various methods such as X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–Vis spectroscopy, transmittance, reflectance etc. The synthesized ZnO thin films were c-axis oriented with hexagonal crystal structure as confirmed from XRD. All deposited films were specular and show high transmittance (∼85%) in visible region with steep fall off at 375 nm. The photoconductive MSM UV photodetector showed relatively high photocurrent (1.3 mA) and fast switching. ZnO thin films exhibited relatively high photoresponsivity (788 A/W) with cut of wavelength ∼375 nm signifying their application as UV detector

  14. High performance ceramic interconnect material for solid oxide fuel cells (SOFCs): Ca- and transition metal-doped yttrium chromite

    Science.gov (United States)

    Yoon, Kyung Joong; Stevenson, Jeffrey W.; Marina, Olga A.

    2011-10-01

    The effect of transition metal substitution on thermal and electrical properties of Ca-doped yttrium chromite was investigated in relation to use as a ceramic interconnect in high temperature solid oxide fuel cells (SOFCs). 10 at.% Co, 4 at.% Ni, and 1 at.% Cu substitution on B-site of 20 at.% Ca-doped yttrium chromite led to a close match of thermal expansion coefficient (TEC) with that of 8 mol% yttria-stabilized zirconia (YSZ), and a single phase Y0.8Ca0.2Cr0.85Co0.1Ni0.04Cu0.01O3 remained stable between 25 and 1100 °C over a wide oxygen partial pressure range. Doping with Cu significantly facilitated densification of yttrium chromite. Ni dopant improved both electrical conductivity and dimensional stability in reducing environments, likely through diminishing the oxygen vacancy formation. Substitution with Co substantially enhanced electrical conductivity in oxidizing atmosphere, which was attributed to an increase in charge carrier density and hopping mobility. Electrical conductivity of Y0.8Ca0.2Cr0.85Co0.1Ni0.04Cu0.01O3 at 900 °C is 57 S cm-1 in air and 11 S cm-1 in fuel (pO2 = 5 × 10-17 atm) environments. Chemical compatibility of doped yttrium chromite with other cell components was verified at the processing temperatures. Based on the chemical and dimensional stability, sinterability, and thermal and electrical properties, Y0.8Ca0.2Cr0.85Co0.1Ni0.04Cu0.01O3 is suggested as a promising SOFC ceramic interconnect to potentially overcome technical limitations of conventional acceptor-doped lanthanum chromites.

  15. Metallic amorphous electrodeposited molybdenum coating from aqueous electrolyte: Structural, electrical and morphological properties under current density

    Science.gov (United States)

    Nemla, Fatima; Cherrad, Djellal

    2016-07-01

    Molybdenum coatings are extensively utilized as back contact for CIGS-based solar cells. However, their electrodeposition from aqueous electrolyte still sophisticates, since long time, owing to the high reactivity with oxygen. In this study, we present a successful 30 min electrodeposition experiment of somewhat thick (∼0.98-2.9 μm) and of moderate surface roughness RMS (∼47-58 nm), metallic bright Mo coating from aqueous electrolyte containing molybdate ions. XRD analysis and Hall Effect measurements have been used to confirm the presence of Mo. The crystal structure of deposits was slightly amorphous in nature to body centred cubic structure (bcc) Mo (110), (211) and (220) face. Lattice parameters exhibit some weak fluctuated tensile stress when compared to the reference lattice parameter. Additionally, our calculated lattice parameters are in good agreement with some previous works from literature. Discussions on the grain growth prove that they are constrained by grain boundary energy not the thickness effect. Further discussions were made on the electrical resistivity and surface morphology. Resonance scattering of Fermi electrons are expected to contribute towards the variation in the film resistivity through the carrier mobility limitation. However, studied samples might be qualified as candidates for solar cell application.

  16. Reduction of Vibration Noise for Amorphous Metal Alloy Core Distribution Transformer

    Institute of Scientific and Technical Information of China (English)

    Liu Daosheng刘道生; Du Boxue杜伯学; Zhang Jiangong张建功; Xu Qiuyuan徐秋元; Qi Zhihai祁治海; Guo Ying郭英

    2015-01-01

    To understand the vibration noise behaviors of amorphous metal alloy core distribution transformer (AMACDT), a 10 kVA prototype was tested under no-load and short-circuit conditions, respectively. The vibration characteristics were described when rated voltage was applied to the secondary side, and the primary side was con-nected with different load resistances. The largest amplitude positions on the upper bracket and tank surfaces were recorded by vibration sensors arranged on the surface. A data-acquisition platform was set up for signal measure-ment. The vibration amplitude related to frequency was discussed, and experimental results indicated that the posi-tion with the largest amplitude accrued in the middle of the upper bracket and tank surface, at phases a and c, re-spectively. The experimental results suggest that magnetostrictive and electrodynamic forces play a major role in exciting the vibration noise. At the same time, some rib-reinforcements were welded on the upper bracket and tank surfaces to lessen the vibration energy, which reduced the noise.

  17. HIGHWAY INFRASTRUCTURE FOCUS AREA NEXT-GENERATION INFRASTRUCTURE MATERIALS VOLUME I - TECHNICAL PROPOSAL & MANAGEMENTENHANCEMENT OF TRANSPORTATION INFRASTRUCTURE WITH IRON-BASED AMORPHOUS-METAL AND CERAMIC COATINGS

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J C

    2007-12-04

    The infrastructure for transportation in the United States allows for a high level of mobility and freight activity for the current population of 300 million residents, and several million business establishments. According to a Department of Transportation study, more than 230 million motor vehicles, ships, airplanes, and railroads cars were used on 6.4 million kilometers (4 million miles) of highways, railroads, airports, and waterways in 1998. Pipelines and storage tanks were considered to be part of this deteriorating infrastructure. The annual direct cost of corrosion in the infrastructure category was estimated to be approximately $22.6 billion in 1998. There were 583,000 bridges in the United States in 1998. Of this total, 200,000 bridges were steel, 235,000 were conventional reinforced concrete, 108,000 bridges were constructed using pre-stressed concrete, and the balance was made using other materials of construction. Approximately 15 percent of the bridges accounted for at this point in time were structurally deficient, primarily due to corrosion of steel and steel reinforcement. Iron-based amorphous metals, including SAM2X5 (Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4}) and SAM1651 (Fe{sub 48}Mo{sub 14}Cr{sub 15}Y{sub 2}C{sub 15}B{sub 6}) have been developed, and have very good corrosion resistance. These materials have been prepared as a melt-spun ribbons, as well as gas atomized powders and thermal-spray coatings. During electrochemical testing in several environments, including seawater at 90 C, the passive film stabilities of these materials were found to be comparable to that of more expensive high-performance alloys, based on electrochemical measurements of the passive film breakdown potential and general corrosion rates. These materials also performed very well in standard salt fog tests. Chromium (Cr), molybdenum (Mo) and tungsten (W) provided corrosion resistance, and boron (B) enabled glass formation

  18. Flow-injection in-line complexation for ion-pair reversed phase high performance liquid chromatography of some metal-4-(2-pyridylazo) resorcinol chelates.

    Science.gov (United States)

    Srijaranai, Supalax; Chanpaka, Saiphon; Kukusamude, Chutima; Grudpan, Kate

    2006-02-28

    Flow injection (FI) was coupled to ion-pair reversed phase high performance liquid chromatography (IP-RPHPLC) for the simultaneous analysis of some metal-4-(2-pyridylazo) resorcinol (PAR) chelates. A simple reverse flow injection (rFI) set-up was used for in-line complexation of metal-PAR chelates prior to their separation by IP-RPHPLC. The rFI conditions were: injection volume of PAR 85muL, flow rate of metal stream 4.5mLmin(-1), concentration of PAR 1.8x10(-4)molL(-1) and the mixing coil length of 150cm. IP-RPHPLC was carried out using a C(18)muBondapak column with the mobile phase containing 37% acetonitrile, 3.0mmolL(-1) acetate buffer pH 6.0 and 6.2mmolL(-1) tetrabutylammonium bromide (TBABr) at a flow rate of 1.0mLmin(-1) and visible detection at 530 and 440nm. The analysis cycle including in-line complexation and separation by IP-RPHPLC was 16min, which able to separate Cr(VI) and the PAR chelates of Co(II), Ni(II) and Cu(II). PMID:18970520

  19. A Simple Dip-coating Approach for Preparation of Three-dimensional Multilayered Graphene-Metal Oxides Hybrid Nanostructures as High Performance Lithium-Ion Battery Electrodes

    International Nuclear Information System (INIS)

    Graphical abstract: We have developed a three-dimensional (3D) multilayered graphene-metal oxide hybrid nanostructure using a simple dip-coating method. A high porosity nickel foam is used both as a current collector and template for the fabrication of 3D structured electrodes. Because of their unique features, the 3D multilayered graphene-metal oxide electrodes exhibit superior electrochemical performances as anodes for LIBs. - Highlights: • We have developed a 3D multilayered graphene-metal oxide electrodes by dip-coating • The 3D graphene-metal oxide electrodes show superior electrochemical performances • Our method is effective for fabricating 3D graphene-metal oxide electrodes - Abstract: High-performance lithium ion battery (LIB) featured with excellent rate properties and cycling stability is highly required in various application fields. However, at this point in time, its practicality is very challenging due to the kinetic barrier related to ineffective electron and Li ion transfer in the batteries. Therefore, design of the electrode structure with higher storage and rate performances is very desirable. In this paper, we have developed a three-dimensional (3D) multilayered graphene-metal oxide hybrid nanostructure using a simple dip-coating method. A high porosity nickel foam is used both as a current collector and template for the fabrication of 3D structured electrodes. Graphene act both as buffer layers, preventing the aggregation of metal oxides, and provide electron pathways for fast electron transfer. Because of their unique features, the electrodes exhibit superior electrochemical performances as anodes for LIBs (graphene-Mn3O4@nickel foam, ∼ 1000 mA h g−1 after 50 cycles; graphene-Fe3O4@nickel foam, ∼ 1200 mA h g−1 at a current density of 200 mA g−1). The enhancement of the electrochemical properties can be attributed to the fact that the 3D multilayered structure can accommodate the volume expansion of metal oxides and maintain the

  20. Amorphous Metal Tungsten Nitride and its Application for Micro and Nanoelectromechanical Applications

    KAUST Repository

    Mayet, Abdulilah M.

    2016-05-01

    The objective of this doctoral thesis is to develop, engineer and investigate an amorphous metal tungsten nitride (aWNx) and to study its functionality for applications focused on electromechanical system at the nano-scale. Charge transport based solid state device oriented complementary metal oxide semiconductor (CMOS) electronics have reached a level where they are scaled down to nearly their fundamental limits regarding switching speed, off state power consumption and the on state power consumption due to the fundamental limitation of sub-threshold slope (SS) remains at 60 mV/dec. NEM switch theoretically and practically offers the steepest sub-threshold slope and practically has shown zero static power consumption due to their physical isolation originated from the nature of their mechanical operation. Fundamental challenges remain with NEM switches in context of their performance and reliability: (i) necessity of lower pull-in voltage comparable to CMOS technology; (ii) operation in ambient/air; (iii) increased ON current and decreased ON resistance; (iv) scaling of devices and improved mechanical and electrical contacts; and (v) high endurance. The “perfect” NEM switch should overcome all the above-mentioned challenges. Here, we show such a NEM switch fabricated with aWNx to show (i) sub-0.3-volt operation; (ii) operation in air and vacuum; (iii) ON current as high as 0.5 mA and ON resistance lower than 5 kΩ; (iv) improved mechanical contact; and the most importantly (v) continuous switching of 8 trillion cycles for more than 10 days with the highest switching speed is 30 nanosecond without hysteresis. In addition, tungsten nitride could be the modern life vine by fulfilling the demand of biodegradable material for sustainable life regime. Transient electronics is a form of biodegradable electronics as it is physically disappearing totally or partially after performing the required function. The fabricated aWNx suites this category very well, despite not

  1. Tendency of metallic crystals to amorphization in the process of severe (Megaplastic) deformation

    Science.gov (United States)

    Glezer, A. M.; Sundeev, R. V.; Shalimova, A. V.

    2012-11-01

    The main features of the transition of crystalline Ni50Ti30Hf20, Ti50Ni25Cu25, Zr50Ni18Ti17Cu15, and Fe78B8.5Si9P4.5 alloys with various tendencies to amorphization into an amorphous state upon melt quenching and in the course of severe deformation in Bridgman anvils have been considered. The crystalline state of these alloys has been produced using various methods of annealing. In the iron-based alloy, single-phase and two-phase crystalline states have been studied. The nickel- and titanium-based alloys after annealing were in a single-phase crystalline state; the zirconium-based alloy, in a two-phase state. It is shown that at the same degree of deformation the rates of amorphization of crystalline alloys differ substantially; namely, the single-phase crystalline titanium- and iron-based alloys amorphize easily, whereas the Zr-based alloy amorphizes only poorly, just like the two-phase iron-based alloy. It can be assumed that the tendency to deformation-induced amorphization of crystalline alloys and the corresponding crystalline phases is mainly determined by three factors: mechanical, thermodynamic, and concentration-related.

  2. Second amorphous-to-crystalline phase transformation in Cu60Ti20Zr20 bulk metallic glass

    DEFF Research Database (Denmark)

    Cao, Q.P.; Li, J.F.; Zhang, P.N.;

    2007-01-01

    The second amorphous-to-crystalline phase transformation in Cu60Ti20Zr20 bulk metallic glass was investigated by differential scanning calorimetry and x-ray diffractometry. The difference of the Gibbs free energies between the amorphous phase and the crystalline products during the transformation...... is estimated to be about 2.46 kJ mol(-1) at 753 K, much smaller than the 61 kJ mol(-1) obtained assuming that it is a polymorphic transformation. It was revealed that the phase transformation occurs through a eutectic crystallization of Cu51Zr14 and Cu2TiZr14 having an effective activation energy of the order...... of 400 kJ mol(-1). The average Avrami exponent n is about 2.0, indicating that the crystallization is diffusion controlled....

  3. A study of the diffusion mechanism in glasses: a theoretical and experimental study of tracers diffusion in amorphous metallic alloys

    International Nuclear Information System (INIS)

    The principal aims of this work are a better understanding of the experimental situation in amorphous metallic alloys and a tentative explanation of the role of collective mechanisms in matter transport. Self- and solute-diffusion of Hf, Au and Cu tracers in amorphous Ni Zr alloy have been studied. We study by SIMS analysis the broadening of the concentration profile with temperature and pressure, in thin amorphous layers which were prepared by sputtering and properly relaxed. The diffusion coefficient variation with temperature shows an Arrhenius behaviour for all of our tracers. The activation energy amount to 1.55 eV for Cu, 1.65 eV for Au and 1.78 eV for Hf and corresponds to nearly one half of the corresponding energy in crystalline zirconium. The diffusion coefficients variation with hydrostatic pressure yields an activation volume equal to one half of an average atomic volume of our matrix for medium and large sized tracers Au, Hf and a smaller activation volume for Cu. The second part of our work consists of numerical simulations of atomic displacements in a generic glass by two complementary methods. In a Lennard-Jones alloy with size effect, we observe by molecular dynamics (MD) some correlated displacements which consist of substitution cycles or chains. The associated energy of these collective events represents nearly 15 pc of that found in crystalline Lennard- Jones. The systematic exploration of energy surface in space configuration made with activation-relaxation technique ART yields energy distributions of stable and saddles positions and opens the way to an evaluation of diffusion coefficients. The events found by ART are qualitatively close to MD ones, but the averaged activation energy associated with these events represents only 10 pc of the crystalline one. This clearly points towards the limit of Lennard-Jones potential, which is not enough representative of actual glasses. This is the reason why an interaction model closer to amorphous

  4. Development of an SU-8 MEMS process with two metal electrodes using amorphous silicon as a sacrificial material

    Science.gov (United States)

    Ramadan, Khaled S.; Nasr, Tarek; Foulds, Ian G.

    2013-03-01

    This work presents an SU-8 surface micromachining process using amorphous silicon as a sacrificial material, which also incorporates two metal layers for electrical excitation. SU-8 is a photo-patternable polymer that is used as a structural layer for MEMS and microfluidic applications due to its mechanical properties, biocompatibility and low cost. Amorphous silicon is used as a sacrificial layer in MEMS applications because it can be deposited in large thicknesses, and can be released in a dry method using XeF2, which alleviates release-based stiction problems related to MEMS applications. In this work, an SU-8 MEMS process was developed using α-Si as a sacrificial layer. Two conductive metal electrodes were integrated in this process to allow out-of-plane electrostatic actuation for applications like MEMS switches and variable capacitors. In order to facilitate more flexibility for MEMS designers, the process can fabricate dimples that can be conductive or nonconductive. Additionally, this SU-8 process can fabricate SU-8 MEMS structures of a single layer of two different thicknesses. Process parameters were optimized for two sets of thicknesses: thin (5-10 µm) and thick (130 µm). The process was tested fabricating MEMS switches, capacitors and thermal actuators.

  5. Development of an SU-8 MEMS process with two metal electrodes using amorphous silicon as a sacrificial material

    KAUST Repository

    Ramadan, Khaled S.

    2013-02-08

    This work presents an SU-8 surface micromachining process using amorphous silicon as a sacrificial material, which also incorporates two metal layers for electrical excitation. SU-8 is a photo-patternable polymer that is used as a structural layer for MEMS and microfluidic applications due to its mechanical properties, biocompatibility and low cost. Amorphous silicon is used as a sacrificial layer in MEMS applications because it can be deposited in large thicknesses, and can be released in a dry method using XeF2, which alleviates release-based stiction problems related to MEMS applications. In this work, an SU-8 MEMS process was developed using ;-Si as a sacrificial layer. Two conductive metal electrodes were integrated in this process to allow out-of-plane electrostatic actuation for applications like MEMS switches and variable capacitors. In order to facilitate more flexibility for MEMS designers, the process can fabricate dimples that can be conductive or nonconductive. Additionally, this SU-8 process can fabricate SU-8 MEMS structures of a single layer of two different thicknesses. Process parameters were optimized for two sets of thicknesses: thin (5-10 m) and thick (130 m). The process was tested fabricating MEMS switches, capacitors and thermal actuators. © 2013 IOP Publishing Ltd.

  6. Analysis of amorphous indium-gallium-zinc-oxide thin-film transistor contact metal using Pilling-Bedworth theory and a variable capacitance diode model

    OpenAIRE

    Kiani, Ahmed; Hasko1, David G; William I. Milne; Flewitt, Andrew J.

    2013-01-01

    It is widely reported that threshold voltage and on-state current of amorphous indiumgallium- zinc-oxide bottom-gate thin-film transistors is strongly influenced by the choice of source/drain contact metal. Electrical characterisation of thin-film transistors indicates that the electrical properties depend on the type and thickness of the metal(s) used. Electron transport mechanisms and possibilities for control of the defect state density are discussed. Pilling-Bedworth theory...

  7. High performance liquid chromatography of substituted aromatics with the metal-organic framework MIL-100(Fe): Mechanism analysis and model-based prediction.

    Science.gov (United States)

    Qin, Weiwei; Silvestre, Martin Eduardo; Li, Yongli; Franzreb, Matthias

    2016-02-01

    Metal-organic framework (MOF) MIL-100(Fe) with well-defined thickness was homogenously coated onto the outer surface of magnetic microparticles via a liquid-phase epitaxy method. The as-synthesized MIL-100(Fe) was used as stationary phase for high-performance liquid chromatography (HPLC) and separations of two groups of mixed aromatic hydrocarbons (toluene, styrene and p-xylene; acetanilide, 2-nirtoaniline and 1-naphthylamine) using methanol/water as mobile phase were performed to evaluate its performance. Increasing water content of the mobile phase composition can greatly improve the separations on the expense of a longer elution time. Stepwise elution significantly shortens the elution time of acetanilide, 2-nirtoaniline and 1-naphthylamine mixtures, while still achieving a baseline separation. Combining the experimental results and in-depth modeling using a recently developed chromatographic software (ChromX), adsorption equilibrium parameters, including the affinities and maximum capacities, for each analyte toward the MIL-100(Fe) are obtained. In addition, the pore diffusivity of aromatic hydrocarbons within MIL-100(Fe) was determined to be 5×10(-12)m(2)s(-1). While the affinities of MIL-100(Fe) toward the analyte molecules differs much, the maximum capacities of the analytes are in a narrow range with q*MOFmax,toluene=3.55molL(-1), q*MOFmax,styrene or p-xylene=3.53molL(-1), and q*MOFmax,anilines=3.12molL(-1) corresponding to approximately 842 toluene and 838 styrene or p-xylene, and 740 aniline molecules per MIL-100(Fe) unit cell, respectively.

  8. High thermal stability of the amorphous oxide in Ti44.5Cu44.5Zr7Be4 metallic glass

    Directory of Open Access Journals (Sweden)

    Sung Hyun Park

    2015-11-01

    Full Text Available The oxidation behavior of Ti44.5Cu44.5Zr7Be4 metallic glass has been investigated. The oxide layer with a fully amorphous structure forms when heated up to the SCL temperature region, indicating that the presence of Be in the oxide layer improves the thermal stability of the amorphous oxide. The amorphous oxide is stable even when heated above the crystallization onset temperature. The thickness of the amorphous oxide layer reaches to ∼160 nm when heated up to 773 K. The oxide layer grows in both inward and outward directions, leaving Cu-enriched crystalline particles at the middle section of the oxide layer.

  9. Application of Be-free Zr-based amorphous sputter coatings as a brazing filler metal in CANDU fuel bundle manufacture

    International Nuclear Information System (INIS)

    Amorphous sputter coatings of Be-free multi-component Zr-based alloys were applied as a novel brazing filler metal for Zircaloy-4 brazing. By applying the homogeneous and amorphous-structured layers coated by sputtering the crystalline targets, the highly reliable joints were obtained with the formation of predominantly grown α-Zr grains owing to a complete isothermal solidification, exhibiting high tensile and fatigue strengths as well as excellent corrosion resistance, which were comparable to those of Zircaloy-4 base metal. The present investigation showed that Be-free and Zr-based multi-component amorphous sputter coatings can offer great potential for brazing Zr alloys and manufacturing fuel rods in CANDU fuel bundle system. (author)

  10. Modification of semiconductor or metal nanoparticle lattices in amorphous alumina by MeV heavy ions

    Science.gov (United States)

    Bogdanović Radović, I.; Buljan, M.; Karlušić, M.; Jerčinović, M.; Dražič, G.; Bernstorff, S.; Boettger, R.

    2016-09-01

    In the present work we investigate effects of MeV heavy ions (from 0.4 MeV Xe to 15 MeV Si) on regularly ordered nanoparticle (NP) lattices embedded in amorphous alumina matrix. These nanostructures were produced by self-assembling growth using magnetron-sputtering deposition. From grazing incidence small-angle x-ray scattering measurements we have found that the used MeV heavy ions do not change the NP sizes, shapes or distances among them. However, ions cause a tilt of the entire NP lattice in the direction parallel to the surface. The tilt angle depends on the incident ion energy, type and the applied fluence and a nearly linear increase of the tilt angle with the ion fluence and irradiation angle was found. This way, MeV heavy ion irradiation can be used to design custom-made NP lattices. In addition, grazing incidence small-angle x-ray scattering can be effectively used as a method for the determination of material redistribution/shift caused by the ion hammering effect. For the first time, the deformation yield in amorphous alumina was determined for irradiation performed at the room temperature.

  11. High Performance Marine Vessels

    CERN Document Server

    Yun, Liang

    2012-01-01

    High Performance Marine Vessels (HPMVs) range from the Fast Ferries to the latest high speed Navy Craft, including competition power boats and hydroplanes, hydrofoils, hovercraft, catamarans and other multi-hull craft. High Performance Marine Vessels covers the main concepts of HPMVs and discusses historical background, design features, services that have been successful and not so successful, and some sample data of the range of HPMVs to date. Included is a comparison of all HPMVs craft and the differences between them and descriptions of performance (hydrodynamics and aerodynamics). Readers will find a comprehensive overview of the design, development and building of HPMVs. In summary, this book: Focuses on technology at the aero-marine interface Covers the full range of high performance marine vessel concepts Explains the historical development of various HPMVs Discusses ferries, racing and pleasure craft, as well as utility and military missions High Performance Marine Vessels is an ideal book for student...

  12. Change of quasilattice constant during amorphous-to-quasicrystalline phase transformation in Zr65Al7.5Ni10Cu7.5Ag10 metallic glass

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Rasmussen, A.R.; Jensen, C.H.;

    2002-01-01

    The amorphous-to-quasicrystalline phase transformation in a Zr65Al7.5Ni10Cu7.5Ag10 metallic glass has been investigated by monitoring the quasilattice constant and the composition of quasicrystalline particles in the samples annealed in vacuum at 663 K for various times. It is found that the quas...

  13. Preface: Proceedings of the 13th Conference on Liquid and Amorphous Metals (LAM13) (Ekaterinburg, Russia, 8 14 July 2007)

    Science.gov (United States)

    Popel, Pjotr; Gelchinskii, Boris; Sidorov, Valeriy

    2008-03-01

    The most recent developments in the field of liquid and amorphous metals and alloys are regularly updated through two complementary international conferences: the liquid and amorphous metals conference (LAM) and the rapidly quenched materials (RQ) conference. The first series of conferences started as LM1 in 1966 at Brookhaven for the basic understanding of liquid metals. The subsequent LM conferences were held in Tokyo (1972) and Bristol (1976). The conference was renewed in Grenoble (1980) as a LAM conference including amorphous metals and continued in Los Angeles (1983), Garmisch-Partenkirchen (1986), Kyoto (1989), Vienna (1992), Chicago (1995), Dortmund (1998), Yokohama (2001) and Metz (2004). The conferences are mainly devoted to liquid and amorphous metals and alloys. However, communications on some non-metallic systems such as semiconductors, quasicrystals etc, are also accepted. The conference tradition strongly encourages participation from junior researchers and graduate students. The 13th conference of the LAM series was organized in Ekaterinburg, Russia, by the Institute of Metallurgy of the Ural Branch of the Russian Academy of Sciences (IMet UB RAS) and the Ural State Pedagogical University (USPU), and held from 8-14 July 2007 under the chairmanship of Professors Pjotr Popel (USPU) and Boris Gelchinskii (IMet UB RAS). Two hundred and forty two active participants and about 60 guest participants from 20 countries attended the conference. There were no parallel sessions and all oral reports were separated into three groups: invited talks (40 min), full-scale oral reports (25 min), and brief oral reports (15 min). The program included ten sessions, ranging from purely theoretical subjects to the technological application of molten and amorphous alloys. The following sessions took place: A: Electronic structure and transport, magnetic properties; B: Phase transitions; C: Structure; D: Atomic dynamics and transport; E: Thermodynamics; F: Modelling

  14. Upper critical fields and superconducting transition temperatures of some zirconium-base amorphous transition-metal alloys

    Science.gov (United States)

    Karkut, M. G.; Hake, R. R.

    1983-08-01

    Superconducting upper critical fields Hc2(T), transition temperatures Tc and normal-state electrical resistivities ρn have been measured in the amorphous transition-metal alloy series Zr1-xCox, Zr1-xNix, (Zr1-xTix)0.78Ni0.22, and (Zr1-xNbx)0.78Ni0.22. Structural integrity of these melt-spun alloys is indicated by x-ray, density, bend-ductility, normal-state electrical resistivity, superconducting transition width, and mixed-state flux-pinning measurements. The specimens display Tc=2.1-3.8 K, ρn=159-190 μΩ cm, and |(dHc2dT)Tc|=28-36 kG/K. These imply electron mean free paths l~2-6 Å, zero-temperature Ginzburg-Landau coherence distances ξG0~50-70 Å, penetration depths λG0~(7-10)×103 Å, and extremely high dirtiness parameters ξ0l~300-1300. All alloys display Hc2(T) curves with negative curvature and (with two exceptions) fair agreement with the standard dirty-limit theory of Werthamer, Helfand, Hohenberg, and Maki (WHHM) for physically reasonable values of spin-orbit-coupling induced, electron-spin-flip scattering time τso. This is in contrast to the anomalously elevated Hc2(T) behavior which is nearly linear in T that is observed by some, and the unphysically low-τso fits to WHHM theory obtained by others, for various amorphous alloys. Current ideas that such anomalies may be due to alloy inhomogeneity are supported by present results on two specimens for which relatively low-τso fits of Hc2(T) to WHHM theory are coupled with superconductive evidence for inhomogeneity: relatively broad transitions at Tc and Hc2 current-density-dependent transitions at Hc2 and (in one specimen) a J-dependent, high-H (>Hc2), resistive "beak effect." In the Zr1-xCox and Zr1-xNix series, Tc decreases linearly with x (and with unfilled-shell average electron-to-atom ratio in the range 5.05previous results for these systems and contrary to the Tc vs behavior of both amorphous and crystalline transition-metal alloys formed between near neighbors in the Periodic Table. Upper

  15. High performance homes

    DEFF Research Database (Denmark)

    Beim, Anne; Vibæk, Kasper Sánchez

    2014-01-01

    Can prefabrication contribute to the development of high performance homes? To answer this question, this chapter defines high performance in more broadly inclusive terms, acknowledging the technical, architectural, social and economic conditions under which energy consumption and production occu...... efficient to operate and valuable for building communities. Herein discussed are two successful examples of low energy prefabricated housing projects built in Copenhagen Denmark, which embraced both the constraints and possibilities offered by prefabrication........ Consideration of all these factors is a precondition for a truly integrated practice and as this chapter demonstrates, innovative project delivery methods founded on the manufacturing of prefabricated buildings contribute to the production of high performance homes that are cost effective to construct, energy...

  16. A study of the diffusion mechanisms in amorphous metallic alloys: diffusion and diffusion under high pressure in an amorphous NiZr alloy; Contribution a l`etude des mecanismes de transport dans les materiaux metalliques amorphes: diffusion et diffusion sous pression dans NiZr amorphe

    Energy Technology Data Exchange (ETDEWEB)

    Grandjean, A.

    1996-03-01

    The aim of this work is a better understanding of the diffusion mechanism in amorphous metallic alloys. Then interdiffusion and hafnium diffusion in amorphous NiZr alloy have been studied. Samples used are made by sputtering co-deposition under vacuum and are well relaxed before the diffusion measurements. The time evolution of resistivity during annealing due to the decay of a composition modulated film has been measured and from this change in resistivity interdiffusion coefficients have been determined. Dependence of Hf diffusion on temperature and pressure has been studied using (SIMS). In this two cases, the diffusion process obeys an Arrhenius law and gives an activation energy of 1.33 eV for interdiffusion, and 0.76 eV for Hf diffusion. An effect of pressure on Hf diffusion has been found leading to an activation volume of 8.5 angstrom{sup 3}. Thanks to these results, two approaches of the diffusion mechanisms in these systems have been proposed. The first comes from a comparison with the diffusion mechanisms in crystalline metals, that is to say by point defects. The second is an hypothesis of collective motions in these non crystalline alloys. (author).

  17. Growth of Hollow Transition Metal (Fe, Co, Ni) Oxide Nanoparticles on Graphene Sheets through Kirkendall Effect as Anodes for High-Performance Lithium-Ion Batteries.

    Science.gov (United States)

    Yu, Xianbo; Qu, Bin; Zhao, Yang; Li, Chunyan; Chen, Yujin; Sun, Chunwen; Gao, Peng; Zhu, Chunling

    2016-01-26

    A general strategy based on the nanoscale Kirkendall effect has been developed to grow hollow transition metal (Fe, Co or Ni) oxide nanoparticles on graphene sheets. When applied as lithium-ion battery anodes, these hollow transition metal oxide-based composites exhibit excellent electrochemical performance, with high reversible capacities and long-term stabilities at a high current density, superior to most transition metal oxides reported to date.

  18. Limits of light-trapping efficiency of prototypical lamellar 1-d metal gratings for amorphous silicon PV cells

    CERN Document Server

    Gablinger, David I

    2014-01-01

    One-dimensional lamellar gratings allow a particularly efficient way for solving Maxwell's equations by expanding the electromagnetic field in the basis of exact eigenmodes of the Helmholtz equation. Then, the solution can be expressed analytically as a superposition of these eigenmodes and the accuracy depends only on the number of modes $N$ included. On this basis, we compute ideal limits of light-trapping performance for prototypical lamellar metal surface relief gratings in amorphous silicon (a-Si) PV cells assuming that light absorption in the metal and front surface reflection can be suppressed. We show that geometric asymmetry can increase absorption. For large enough $N$, convergence of absorption spectra for E polarisation is reached. For H polarisation it is reached for wavelengths $\\lambda<$680-700 nm, while the integrated AM1.5-weighted absorption varies by less than 1\\% at large $N$. For an a-Si layer with height 200 nm and normal incidence, we obtain upper limits of the total absorption of 79...

  19. Comparison of Crevice Corrosion of Fe-Based Amorphous Metal and Crystalline Ni-Cr-Mo Alloy

    Energy Technology Data Exchange (ETDEWEB)

    Shan, X; Ha, H; Payer, J H

    2008-07-24

    The crevice corrosion behaviors of an Fe-based bulk metallic glass alloy (SAM1651) and a Ni-Cr-Mo crystalline alloy (C-22) were studied in 4M NaCl at 100 C with cyclic potentiodynamic polarization and constant potential tests. The corrosion damage morphologies, corrosion products and the compositions of corroded surfaces of these two alloys were studied with optical 3D reconstruction, Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and Auger Electron Spectroscopy (AES). It was found that the Fe-based bulk metallic glass (amorphous alloy) SAM1651 had a more positive breakdown potential and repassivation potential than crystalline alloy C-22 in cyclic potentiodynamic polarization tests and required a more positive oxidizing potential to initiate crevice corrosion in constant potential test. Once crevice corrosion initiated, the corrosion propagation of C-22 was more localized near the crevice border compared to SAM1651, and SAM1651 repassivated more readily than C-22. The EDS results indicated that the corrosion products of both alloys contained high amount of O and were enriched in Mo and Cr. The AES results indicated that a Cr-rich oxide passive film was formed on the surfaces of both alloys, and both alloys were corroded congruently.

  20. Semiconductor to metallic transition in bulk accumulated amorphous indium-gallium-zinc-oxide dual gate thin-film transistor

    International Nuclear Information System (INIS)

    We investigated the effects of top gate voltage (VTG) and temperature (in the range of 25 to 70 oC) on dual-gate (DG) back-channel-etched (BCE) amorphous-indium-gallium-zinc-oxide (a-IGZO) thin film transistors (TFTs) characteristics. The increment of VTG from -20V to +20V, decreases the threshold voltage (VTH) from 19.6V to 3.8V and increases the electron density to 8.8 x 1018cm−3. Temperature dependent field-effect mobility in saturation regime, extracted from bottom gate sweep, show a critical dependency on VTG. At VTG of 20V, the mobility decreases from 19.1 to 15.4 cm2/V ⋅ s with increasing temperature, showing a metallic conduction. On the other hand, at VTG of - 20V, the mobility increases from 6.4 to 7.5cm2/V ⋅ s with increasing temperature. Since the top gate bias controls the position of Fermi level, the temperature dependent mobility shows metallic conduction when the Fermi level is above the conduction band edge, by applying high positive bias to the top gate

  1. AMORPHIZATION IN Nb-M (M=Fe, Co, Ni) BINARY METAL SYSTEMS INDUCED BY ION BEAM ASSISTED DEPOSITION (IBAD)

    Institute of Scientific and Technical Information of China (English)

    F. Pan; F. Zeng; B. Zhao

    2002-01-01

    Ion beam assisted deposition technique (IBAD) was utilized to systematically studyamorphization in binary metal systems of Nb-magnetic element, i.e., Nb-M (M=Fe,Co or Ni). The glass forming range terned as Nb fraction of Nb-Fe system was about34at.% to 56at.%, that of Nb-Co system was about 32at.% to 72at.% and that of Nb-Ni about 20at.% to 80at.%. Similar percolation patterns were found in amorphousalloy films. The fractal dimensions of the percolation patterns approach to 2, whichindicates 2-D layer growth for amorphous phases. It is regarded that the assistedAr+ ion beam duringthe deposition process plays important role for the 2-D layergrowth. Some metastable crystalline phases were obtained in these three systems byIBAD, e.g., bcc supersaturated solid solutions in Nb-Fe and Nb-Co systems, fcc andhcp phases in Nb-Co and Nb-Ni systems. The formation and competing between theamorphous and the metastable crystalline phases were determined by both the phases'thermodynamic states in binary metal systems and kinetics during IBAD process.

  2. Semiconductor to metallic transition in bulk accumulated amorphous indium-gallium-zinc-oxide dual gate thin-film transistor

    Directory of Open Access Journals (Sweden)

    Minkyu Chun

    2015-05-01

    Full Text Available We investigated the effects of top gate voltage (VTG and temperature (in the range of 25 to 70 oC on dual-gate (DG back-channel-etched (BCE amorphous-indium-gallium-zinc-oxide (a-IGZO thin film transistors (TFTs characteristics. The increment of VTG from -20V to +20V, decreases the threshold voltage (VTH from 19.6V to 3.8V and increases the electron density to 8.8 x 1018cm−3. Temperature dependent field-effect mobility in saturation regime, extracted from bottom gate sweep, show a critical dependency on VTG. At VTG of 20V, the mobility decreases from 19.1 to 15.4 cm2/V ⋅ s with increasing temperature, showing a metallic conduction. On the other hand, at VTG of - 20V, the mobility increases from 6.4 to 7.5cm2/V ⋅ s with increasing temperature. Since the top gate bias controls the position of Fermi level, the temperature dependent mobility shows metallic conduction when the Fermi level is above the conduction band edge, by applying high positive bias to the top gate.

  3. Semiconductor to metallic transition in bulk accumulated amorphous indium-gallium-zinc-oxide dual gate thin-film transistor

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Minkyu; Chowdhury, Md Delwar Hossain; Jang, Jin, E-mail: jjang@khu.ac.kr [Advanced Display Research Center and Department of Information Display, Kyung Hee University, Seoul 130-701 (Korea, Republic of)

    2015-05-15

    We investigated the effects of top gate voltage (V{sub TG}) and temperature (in the range of 25 to 70 {sup o}C) on dual-gate (DG) back-channel-etched (BCE) amorphous-indium-gallium-zinc-oxide (a-IGZO) thin film transistors (TFTs) characteristics. The increment of V{sub TG} from -20V to +20V, decreases the threshold voltage (V{sub TH}) from 19.6V to 3.8V and increases the electron density to 8.8 x 10{sup 18}cm{sup −3}. Temperature dependent field-effect mobility in saturation regime, extracted from bottom gate sweep, show a critical dependency on V{sub TG}. At V{sub TG} of 20V, the mobility decreases from 19.1 to 15.4 cm{sup 2}/V ⋅ s with increasing temperature, showing a metallic conduction. On the other hand, at V{sub TG} of - 20V, the mobility increases from 6.4 to 7.5cm{sup 2}/V ⋅ s with increasing temperature. Since the top gate bias controls the position of Fermi level, the temperature dependent mobility shows metallic conduction when the Fermi level is above the conduction band edge, by applying high positive bias to the top gate.

  4. High performance systems

    Energy Technology Data Exchange (ETDEWEB)

    Vigil, M.B. [comp.

    1995-03-01

    This document provides a written compilation of the presentations and viewgraphs from the 1994 Conference on High Speed Computing given at the High Speed Computing Conference, {open_quotes}High Performance Systems,{close_quotes} held at Gleneden Beach, Oregon, on April 18 through 21, 1994.

  5. Danish High Performance Concretes

    DEFF Research Database (Denmark)

    Nielsen, M. P.; Christoffersen, J.; Frederiksen, J.

    1994-01-01

    In this paper the main results obtained in the research program High Performance Concretes in the 90's are presented. This program was financed by the Danish government and was carried out in cooperation between The Technical University of Denmark, several private companies, and Aalborg University...

  6. Atomic structure and crystallization processes of amorphous (Co,Ni)–P metallic alloy

    Energy Technology Data Exchange (ETDEWEB)

    Modin, Evgeny B., E-mail: modin.eb@dvfu.ru [Far Eastern Federal University, Shukhanova 8, Vladivostok 690950 (Russian Federation); Pustovalov, Evgeny V.; Fedorets, Aleksander N.; Dubinets, Aleksander V.; Grudin, Boris N.; Plotnikov, Vladimir S. [Far Eastern Federal University, Shukhanova 8, Vladivostok 690950 (Russian Federation); Grabchikov, Sergey S. [Scientific and Practical Centre of Material Science, Belarus National Academy of Sciences, P. Brovki 19, Minsk 220072 (Belarus)

    2015-08-25

    Highlights: • The CoP–CoNiP amorphous alloys were studied by the Cs-corrected high resolution transmission electron microscopy. • In situ heating experiments showed that crystallization starts at 200–250 °C on the network frame and cell boundaries. • Crystal growth occurs at the free surface, then the remaining material in the volume is crystallized. • Adding nickel to the CoP alloy leads to higher thermal stability. • At the beginning of crystallization there are high diffusion coefficients, 1.2–2.4 ∗ 10{sup −18} m{sup 2}/s at 250 °C. - Abstract: This work concerns the in situ investigation of the atomic structure of (Co,Ni)–P alloys during relaxation and crystallization by high resolution transmission electron microscopy. The CoP–CoNiP alloys, in the initial state, have a hierarchical network-like disordered structure. Crystallization starts at 200–250 °C on the network frame and cell boundaries. In the early stages, crystal growth occurs at the free surface, then the remaining material in the volume is crystallized. The diffusion coefficient at the start of crystallization is 1.2–2.4 × 10{sup −18} m{sup 2}/s at 250 °C and we assume that the high diffusion speed is due to surface diffusion.

  7. Electrochemical Studies of Passive Film Stability on Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 Amorphous Metal in Seawater at 90oCElectrochemical Studies of Passive Film Stability on Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 Amorphous Metal in Seawater at 9

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J C; Haslam, J; Day, S D; Lian, T; Saw, C K; Hailey, P D; Choi, J S; Rebak, R B; Yang, N; Payer, J H; Perepezko, J H; Hildal, K; Lavernia, E J; Ajdelsztajn, L; Branagan, D J; Buffa, E J; Aprigliano, L F

    2007-04-25

    An iron-based amorphous metal, Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4} (SAM2X5), with very good corrosion resistance was developed. This material was prepared as a melt-spun ribbon, as well as gas atomized powder and a thermal-spray coating. During electrochemical testing in several environments, including seawater at 90 C, the passive film stability was found to be comparable to that of high-performance nickel-based alloys, and superior to that of stainless steels, based on electrochemical measurements of the passive film breakdown potential and general corrosion rates. This material also performed very well in standard salt fog tests. Chromium (Cr), molybdenum (Mo) and tungsten (W) provided corrosion resistance, and boron (B) enabled glass formation. The high boron content of this particular amorphous metal made it an effective neutron absorber, and suitable for criticality control applications. This material and its parent alloy maintained corrosion resistance up to the glass transition temperature, and remained in the amorphous state during exposure to relatively high neutron doses.

  8. DIRECT SPECTRUM ANALYSIS OF ANELASTIC DEFORMATION RESPONSE DURING STRUCTURAL RELAXATION OF AMORPHOUS METALS

    NARCIS (Netherlands)

    CSACH, K; Ocelik, Vaclav; MISKUF, J; BENGUS, VZ; DUHAJ, P

    1994-01-01

    Direct relaxation time spectrum analysis method has been successfully used to observe and. to study changes in the kinetics of isothermal anelastic deformation response of soft magnetic metallic glass Fe40Ni40B20 during structural relaxation. Computed relaxation time spectra contain three or four qu

  9. High Performance Work Systems

    OpenAIRE

    Boselie, Paul; Wiele, Ton

    2002-01-01

    textabstractResearch, summarized and classified in the work of Delery and Doty (1996), Guest (1997), Paauwe and Richardson (1997) and Boselie et al. (2001), suggests significant impact of Human Resources Management (HRM) on the competitive advantage of organizations. The mainstream research on this topic reveals encouraging results on organizational level. Also in relation to Total Quality Management (TQM) there is research evidence that 'best practices' and/or 'high performance work systems'...

  10. Swift heavy ion irradiation of metal containing tetrahedral amorphous carbon films

    Science.gov (United States)

    Karaseov, P. A.; Protopopova, V. S.; Karabeshkin, K. V.; Shubina, E. N.; Mishin, M. V.; Koskinen, J.; Mohapatra, S.; Tripathi, A.; Avasthi, D. K.; Titov, A. I.

    2016-07-01

    Thin carbon films were grown at room temperature on (0 0 1) n-Si substrate using dual cathode filtered vacuum arc deposition system. Graphite was used as a source of carbon atoms and separate metallic electrode was simultaneously utilized to introduce Ni or Cu atoms. Films were irradiated by 100 MeV Ag7+ ions to fluences in the range 1 × 1010-3 × 1011 cm-2. Rutherford backscattering spectroscopy, Raman scattering, scanning electron microscopy and atomic force microscopy in conductive mode were used to investigate film properties and structure change under irradiation. Some conductive channels having metallic conductivity type were found in the films. Number of such channels is less than number of impinged ions. Presence of Ni and Cu atoms increases conductivity of those conductive channels. Fluence dependence of all properties studied suggests different mechanisms of swift heavy ion irradiation-induced transformation of carbon matrix due to different chemical effect of nickel and copper atoms.

  11. High performance AC drives

    CERN Document Server

    Ahmad, Mukhtar

    2010-01-01

    This book presents a comprehensive view of high performance ac drives. It may be considered as both a text book for graduate students and as an up-to-date monograph. It may also be used by R & D professionals involved in the improvement of performance of drives in the industries. The book will also be beneficial to the researchers pursuing work on multiphase drives as well as sensorless and direct torque control of electric drives since up-to date references in these topics are provided. It will also provide few examples of modeling, analysis and control of electric drives using MATLAB/SIMULIN

  12. Clojure high performance programming

    CERN Document Server

    Kumar, Shantanu

    2013-01-01

    This is a short, practical guide that will teach you everything you need to know to start writing high performance Clojure code.This book is ideal for intermediate Clojure developers who are looking to get a good grip on how to achieve optimum performance. You should already have some experience with Clojure and it would help if you already know a little bit of Java. Knowledge of performance analysis and engineering is not required. For hands-on practice, you should have access to Clojure REPL with Leiningen.

  13. High Performance FORTRAN

    Science.gov (United States)

    Mehrotra, Piyush

    1994-01-01

    High performance FORTRAN is a set of extensions for FORTRAN 90 designed to allow specification of data parallel algorithms. The programmer annotates the program with distribution directives to specify the desired layout of data. The underlying programming model provides a global name space and a single thread of control. Explicitly parallel constructs allow the expression of fairly controlled forms of parallelism in particular data parallelism. Thus the code is specified in a high level portable manner with no explicit tasking or communication statements. The goal is to allow architecture specific compilers to generate efficient code for a wide variety of architectures including SIMD, MIMD shared and distributed memory machines.

  14. One-pot synthesis of high-performance Co/graphene electrocatalysts for glucose fuel cells free of enzymes and precious metals.

    Science.gov (United States)

    Ci, Suqin; Wen, Zhenhai; Mao, Shun; Hou, Yang; Cui, Shumao; He, Zhen; Chen, Junhong

    2015-06-01

    A facile recipe has been developed to prepare three-dimensional nanoarchitectures of nitrogen-doped graphene loading Co nanoparticle hybrids (Co/NG). The hybrids show an outstanding electrocatalytic activity for glucose oxidation reaction (GOR) and oxygen reduction reaction (ORR), and thus can be used as electrode materials of a nonenzymatic and precious-metal-free glucose fuel cell (GFC). PMID:25960100

  15. Facile Routes To Improve Performance of Solution-Processed Amorphous Metal Oxide Thin Film Transistors by Water Vapor Annealing.

    Science.gov (United States)

    Park, Won-Tae; Son, Inyoung; Park, Hyun-Woo; Chung, Kwun-Bum; Xu, Yong; Lee, Taegweon; Noh, Yong-Young

    2015-06-24

    Here, we report on a simple and high-rate oxidization method for producing solution-based compound mixtures of indium zinc oxide (IZO) and indium gallium zinc oxide (IGZO) metal-oxide semiconductors (MOS) for thin-film transistor (TFT) applications. One of the issues for solution-based MOS fabrication is how to sufficiently oxidize the precursor in order to achieve high performance. As the oxidation rate of solution processing is lower than vacuum-based deposition such as sputtering, devices using solution-processed MOS exhibit relatively poorer performance. Therefore, we propose a method to prepare the metal-oxide precursor upon exposure to saturated water vapor in a closed volume for increasing the oxidization efficiency without requiring additional oxidizing agent. We found that the hydroxide rate of the MOS film exposed to water vapor is lower than when unexposed (≤18%). Hence, we successfully fabricated oxide TFTs with high electron mobility (27.9 cm(2)/V·s) and established a rapid process (annealing at 400 °C for 5 min) that is much shorter than the conventional as-deposited long-duration annealing (at 400 °C for 1 h) whose corresponding mobility is even lower (19.2 cm(2)/V·s). PMID:26043206

  16. Technology breakthroughs in high performance metal-oxide-semiconductor devices for ultra-high density, low power non-volatile memory applications

    Science.gov (United States)

    Hong, Augustin Jinwoo

    Non-volatile memory devices have attracted much attention because data can be retained without power consumption more than a decade. Therefore, non-volatile memory devices are essential to mobile electronic applications. Among state of the art non-volatile memory devices, NAND flash memory has earned the highest attention because of its ultra-high scalability and therefore its ultra-high storage capacity. However, human desire as well as market competition requires not only larger storage capacity but also lower power consumption for longer battery life time. One way to meet this human desire and extend the benefits of NAND flash memory is finding out new materials for storage layer inside the flash memory, which is called floating gate in the state of the art flash memory device. In this dissertation, we study new materials for the floating gate that can lower down the power consumption and increase the storage capacity at the same time. To this end, we employ various materials such as metal nanodot, metal thin film and graphene incorporating complementary-metal-oxide-semiconductor (CMOS) compatible processes. Experimental results show excellent memory effects at relatively low operating voltages. Detailed physics and analysis on experimental results are discussed. These new materials for data storage can be promising candidates for future non-volatile memory application beyond the state of the art flash technologies.

  17. Determination of linear aliphatic aldehydes in heavy metal containing waters by high-performance liquid chromatography using 2,4-dinitrophenylhydrazine derivatization.

    Science.gov (United States)

    Lin, Yi-Liang; Wang, Po-Yen; Hsieh, Ling-Ling; Ku, Kuan-Hsuan; Yeh, Yun-Tai; Wu, Chien-Hou

    2009-09-01

    A simple and sensitive method is described for the determination of picomolar amounts of C(1)-C(9) linear aliphatic aldehydes in waters containing heavy metal ions. In this method, aldehydes were first derivatized with 2,4-dinitrophenylhydrazine (DNPH) at optimized pH 1.8 for 30 min and analyzed by HPLC with UV detector at 365 nm. Factors affecting the derivatization reaction of aldehydes and DNPH were investigated. Cupric ion, an example of heavy metals, is a common oxidative reagent, which may oxidize DNPH and greatly interfere with the determination of aldehydes. EDTA was used to effectively mask the interferences by heavy metal ions. The method detection limits for direct injection of derivatized most aldehydes except formaldehyde were of the order of 7-28 nM. The detection limit can be further lowered by using off-line C(18) adsorption cartridge enrichment. The recoveries of C(1)-C(9) aldehydes were 93-115% with a relative standard deviation of 3.6-8.1% at the 0.1 microM level for aldehydes. The HPLC-DNPH method has been applied for determining aldehyde photoproducts from Cu(II)-amino acid complex systems. PMID:19643424

  18. JOINING OF MOLYBDENUM DISILICIDE TO STAINLESS STEEL USING AMORPHOUS METAL BRAZES-RESIDUAL STRESS ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    VAIDYA, RAJENDRA U [Los Alamos National Laboratory; KAUTZ, DOUGLAS D. [Los Alamos National Laboratory; GALLEGOS, DAVID E. [Los Alamos National Laboratory

    2007-01-30

    Molybdenum disilicide (MoSi{sub 2})/stainless steel 316 L jOints were produced by high temperature brazing using a cobalt-based metallic-glass (METGLAS{trademark} 2714A). Successful joining was completed in two different ways; either by feeding excess braze into the braze gap upon heating or by constraining the MoSi{sub 2}/stainiess steel assembly with an alumina (Al{sub 2}O{sub 3}) fixture during the heating cycle. These steps were necessary to ensure the production of a high quality void free joint. Residual stress measurements were completed on these joints. Indentation results show higher tensile residual stresses in the stainless steel for the joint with the external constraint, in comparison to the unconstrained state. In contrast, the compressive residual stresses In the MoSi{sub 2} (as measured by X-ray diffraction) were lower in the constrained state relative to the unconstrained state. These results and a lack of residual stress balance indicate that the stress state in the braze is significantly different under the two joining conditions and the volume of the braze plays an important role in the development of the residual stresses. Push-out tests carried out on these joints gave higher joint strengths in the unconstrained as compared to the constrained condition. The results of this study have important implications on the selection of the appropriate joining process (use of constraint versus extra braze).

  19. In vitro metal ion release and biocompatibility of amorphous Mg67Zn28Ca5 alloy with/without gelatin coating

    International Nuclear Information System (INIS)

    Amorphous zinc-rich Mg–Zn–Ca alloys have exhibited good tissue compatibility and low hydrogen evolution in vivo. However, suboptimal cell–surface interaction on magnesium alloy surface observed in vitro could lead to reduced integration with host tissue for regenerative purpose. This study aims to improve cell–surface interaction of amorphous Mg67Zn28Ca5 alloy by coating a gelatin layer by electrospinning. Coated/uncoated alloys were immersed and extracted for 3 days under different CO2. The immersion results showed that pH and metal ion release in the alloy extracts were affected by gelatin coating and CO2, suggesting their roles in alloy biocorrosion and a mechanism has been proposed for the alloy–CO2 system with/without coating. Cytotoxicity results are evident that gelatin-coated alloy with 2-day crosslinking not only exhibited no indirect cytotoxicity, but also supported attachment of L929 and MG63 cell lines around/on the alloy with high viability. Therefore, amorphous Mg67Zn28Ca5 alloy coated with gelatin by electrospinning technique provides a useful method to improve alloy biocompatibility. - Highlights: • Electrospinning is a new method to coat amorphous Mg67Zn28Ca5 alloy with gelatin. • Gelatin-coated alloy has differential effect on pH and ion release at various CO2. • L929 cell proliferation correlates with Mg2+ level in alloy extracts. • Biomimetic gelatin coating significantly improves cell–surface interaction

  20. Pathways toward high-performance perovskite solar cells: review of recent advances in organo-metal halide perovskites for photovoltaic applications

    Science.gov (United States)

    Song, Zhaoning; Watthage, Suneth C.; Phillips, Adam B.; Heben, Michael J.

    2016-04-01

    Organo-metal halide perovskite-based solar cells have been the focus of intense research over the past five years, and power conversion efficiencies have rapidly been improved from 3.8 to >21%. This article reviews major advances in perovskite solar cells that have contributed to the recent efficiency enhancements, including the evolution of device architecture, the development of material deposition processes, and the advanced device engineering techniques aiming to improve control over morphology, crystallinity, composition, and the interface properties of the perovskite thin films. The challenges and future directions for perovskite solar cell research and development are also discussed.

  1. Analytical models for development of high performance metal targets irradiated in IPEN-CNEN/SP Cyclone 30 and Cyclone 18 cyclotrons

    International Nuclear Information System (INIS)

    Analytical models were developed that describe the basic elements for metal targets irradiation in cyclotrons. Important parameters such as maximum beam current value and thermal power deposited on target were obtained and compared with practical situations. In an unprecedented way, were determined analytically the features found in intense thermal transient situations, when high protons concentrations in a small region of the beam cause intense temperature gradients in small regions of the target. Comparing with results found in the literature showed that the developed models are satisfactory, in view of all limitations of the proposed model. (author)

  2. Rapid high-performance sample digestion of base metal ores using high-intensity infrared radiation with determination by nitrogen-based microwave plasma optical spectrometry

    Directory of Open Access Journals (Sweden)

    Yong Wang

    2016-03-01

    Full Text Available Infrared sample digestion technology has been rapidly developed in recent years and its application and digestion performance on a variety of ores of base metals was assessed in this study, using a 6-channel infrared digester. Digestion times of 10 min or less were achieved for all base metal ores investigated, including oxides, sulfides, and silicates of Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Ti, W, and Zn. Performance criteria for all samples were excellent, reflected in z values of less than 2 in all cases. Various acid digestion methods were developed for the selected ore samples under high intensity infrared radiation and delivered virtually complete recoveries of all of the elements of interest. Chromite, the notoriously refractory chromium ore was digested within 10 min and gave 100% recovery of chromium. These digestions were accomplished without resorting to perchloric acid and, for most sample types, without hydrofluoric acid, significantly improving the workplace safety for analysts. Between-channel variation of the analyte recoveries from the 6-channel unit were generally below 2%, suggesting that the digestion methods developed with this platform provide reproducible results to meet various sample preparation demands. The high speed and analyte recovery of these digestions makes this methodology especially attractive for prospectors and developers who demand rapid and reliable results from exploration samples.

  3. Research Status on the Crystallization of Metal Induced Amorphous Silicon Films%非晶硅薄膜的金属诱导晶化研究现状

    Institute of Scientific and Technical Information of China (English)

    田跃生

    2011-01-01

    概述了非晶硅薄膜的金属诱导晶化原理,介绍了Al,Ni两种金属诱导非晶硅薄膜晶化的一般规律,详细探讨了金属诱导条件下非晶硅薄膜的本质晶化机理,旨在为非晶硅薄膜的低温成核、晶化机理研究和多晶硅薄膜的研发制备提供实验支持与理论参考.%The crystallization theory of amorphous silicon film by metal induced was briefly reviewed. The general rules of Al and Ni induced amorphous silicon film crystallization were described and the nature mechanism of metal induced amorphous silicon film crystallization was discussed. It is expected to provide experimental support and theoretical reference to study low temperature nucleation and crystallization mechanism of silicon films and fabricate polycrystalline silicon films.

  4. DOE-DARPA High-Performance Corrosion-Resistant Materials (HPCRM), Annual HPCRM Team Meeting & Technical Review

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J; Brown, B; Bayles, B; Lemieux, T; Choi, J; Ajdelsztajn, L; Dannenberg, J; Lavernia, E; Schoenung, J; Branagan, D; Blue, C; Peter, B; Beardsley, B; Graeve, O; Aprigliano, L; Yang, N; Perepezko, J; Hildal, K; Kaufman, L; Lewandowski, J; Perepezko, J; Hildal, K; Kaufman, L; Lewandowski, J; Boudreau, J

    2007-09-21

    The overall goal is to develop high-performance corrosion-resistant iron-based amorphous-metal coatings for prolonged trouble-free use in very aggressive environments: seawater & hot geothermal brines. The specific technical objectives are: (1) Synthesize Fe-based amorphous-metal coating with corrosion resistance comparable/superior to Ni-based Alloy C-22; (2) Establish processing parameter windows for applying and controlling coating attributes (porosity, density, bonding); (3) Assess possible cost savings through substitution of Fe-based material for more expensive Ni-based Alloy C-22; (4) Demonstrate practical fabrication processes; (5) Produce quality materials and data with complete traceability for nuclear applications; and (6) Develop, validate and calibrate computational models to enable life prediction and process design.

  5. High Performance RAIT

    Institute of Scientific and Technical Information of China (English)

    JamesHughes; CharlesMilligan; 等

    2001-01-01

    The ability to move 10s of TeraBytes in reasonable amounts of time are critical to many of the High Energy Physics applications.This paper examines the issues of high performance,high reliability tape storage systems,and presents the results of a 2-year ASCI Path Forward program to be able to reliably move 1GB/s to an archive that can last 20 years.This paper will cover the requirements.approach,hardware,application software,interface descriptions,performance,measured reliability and predicted reliability.This paper will also touch on future directions for this research.The current research allows systems to sustain 80MB/s of uncompressable data per Fibre Channel interface which is striped out to 8 or more drives.This looks to the application as a single tape drive from both mout and data transfer perspectives .Striping 12 RAIT systems together will provide nearly 1GB/s to tape.The reliability is provided by a method of adding parity tapes to the data stripes.For example,adding 2 parity tapes to an 8-stripe group will allow any 2 of the 10 tapes to be lost or damaged without loss of information.The reliability of RAIT with 8 stripes and 2 parities exceeds that of mirrored tapes while RAIT uses 10 tapes instead of the 16 tapes that a mirror would require.The results of this paper is to be abloe to understand the applicability of RAIT and to be able to understand when it may be useful in High Energy Physics applications.

  6. Self-assembly formation of hollow Ni-Fe-O nanocage architectures by metal-organic frameworks with high-performance lithium storage

    Science.gov (United States)

    Guo, Hong; Li, Tingting; Chen, Weiwei; Liu, Lixiang; Qiao, Jinli; Zhang, Jiujun

    2015-09-01

    A hollow hybrid Ni-Fe-O nanomaterial (NiFe2O4) is synthesized using a precursor of metal-organic frameworks through a simple and cost-effective method. The unique hollow nanocage structures shorten the length of Li-ion diffusion. The hollow structure offers a sufficient void space, which sufficiently alleviates the mechanical stress caused by volume change. Besides, the hybrid elements allow the volume change to take place in a stepwise manner during electrochemical cycle. And thus, the hierarchical hollow NiFe2O4 nanocage electrode exhibits extraordinary electrochemical performance. The stable cyclic performance is obtained for all rates from 1 C to 10 C. Even when the current reaches 10 C, the capacity can also arrive at 652 mAhg-1. Subsequently, a specific capacity of ca. 975 mAhg-1 is recovered when the current rate reduces back to 1 C after 200 cycles. This strategy that derived from NMOFs may shed light on a new route for large-scale synthesis of hollow porous hybrid nanocages for energy storage, environmental remediation and other novel applications.

  7. Optical and Structural Properties of Microcrystalline GaN on an Amorphous Substrate Prepared by a Combination of Molecular Beam Epitaxy and Metal-Organic Chemical Vapor Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Min, Jung-Wook; Hwang, Hyeong-Yong; Kang, Eun-Kyu; Park, Kwangwook; Kim, Ci-Hyun; Lee, Dong-Seon; Jho, Young-Dahl; Bae, Si-Young; Lee, Yong-Tak

    2016-05-01

    Microscale platelet-shaped GaN grains were grown on amorphous substrates by a combined epitaxial growth method of molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD). First, MBE GaN was grown on an amorphous substrate as a pre-orienting layer and its structural properties were investigated. Second, MOCVD grown GaN samples using the different growth techniques of planar and selective area growth (SAG) were comparatively investigated by transmission electron microscopy (TEM), cathodoluminescence (CL), and photoluminescence (PL). In MOCVD planar GaN, strong bound exciton peaks dominated despite the high density of the threading dislocations (TDs). In MOCVD SAG GaN, on the other hand, TDs were clearly reduced with bending, but basal stacking fault (BSF) PL peaks were observed at 3.42 eV. The combined epitaxial method not only provides a deep understanding of the growth behavior but also suggests an alternative approach for the growth of GaN on amorphous substances.

  8. Ferroelectric switching of poly(vinylidene difluoride-trifluoroethylene) in metal-ferroelectric-semiconductor non-volatile memories with an amorphous oxide semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Gelinck, G. H., E-mail: Gerwin.Gelinck@tno.nl [Holst Centre/TNO, High Tech Campus 31, 5656 AE Eindhoven (Netherlands); Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Breemen, A. J. J. M. van; Cobb, B. [Holst Centre/TNO, High Tech Campus 31, 5656 AE Eindhoven (Netherlands)

    2015-03-02

    Ferroelectric polarization switching of poly(vinylidene difluoride-trifluoroethylene) is investigated in different thin-film device structures, ranging from simple capacitors to dual-gate thin-film transistors (TFT). Indium gallium zinc oxide, a high mobility amorphous oxide material, is used as semiconductor. We find that the ferroelectric can be polarized in both directions in the metal-ferroelectric-semiconductor (MFS) structure and in the dual-gate TFT under certain biasing conditions, but not in the single-gate thin-film transistors. These results disprove the common belief that MFS structures serve as a good model system for ferroelectric polarization switching in thin-film transistors.

  9. In vitro metal ion release and biocompatibility of amorphous Mg{sub 67}Zn{sub 28}Ca{sub 5} alloy with/without gelatin coating

    Energy Technology Data Exchange (ETDEWEB)

    Chan, W.Y., E-mail: chan.wing.yue@sgh.com.sg [School of Mechanical and Aerospace Engineering, Nanyang Technological University (Singapore); Department of Plastic, Reconstructive and Aesthetic Surgery, Singapore General Hospital (Singapore); Chian, K.S.; Tan, M.J. [School of Mechanical and Aerospace Engineering, Nanyang Technological University (Singapore)

    2013-12-01

    Amorphous zinc-rich Mg–Zn–Ca alloys have exhibited good tissue compatibility and low hydrogen evolution in vivo. However, suboptimal cell–surface interaction on magnesium alloy surface observed in vitro could lead to reduced integration with host tissue for regenerative purpose. This study aims to improve cell–surface interaction of amorphous Mg{sub 67}Zn{sub 28}Ca{sub 5} alloy by coating a gelatin layer by electrospinning. Coated/uncoated alloys were immersed and extracted for 3 days under different CO{sub 2}. The immersion results showed that pH and metal ion release in the alloy extracts were affected by gelatin coating and CO{sub 2}, suggesting their roles in alloy biocorrosion and a mechanism has been proposed for the alloy–CO{sub 2} system with/without coating. Cytotoxicity results are evident that gelatin-coated alloy with 2-day crosslinking not only exhibited no indirect cytotoxicity, but also supported attachment of L929 and MG63 cell lines around/on the alloy with high viability. Therefore, amorphous Mg{sub 67}Zn{sub 28}Ca{sub 5} alloy coated with gelatin by electrospinning technique provides a useful method to improve alloy biocompatibility. - Highlights: • Electrospinning is a new method to coat amorphous Mg{sub 67}Zn{sub 28}Ca{sub 5} alloy with gelatin. • Gelatin-coated alloy has differential effect on pH and ion release at various CO{sub 2}. • L929 cell proliferation correlates with Mg{sup 2+} level in alloy extracts. • Biomimetic gelatin coating significantly improves cell–surface interaction.

  10. Accelerated growth from amorphous clusters to metallic nanoparticles observed in electrochemical deposition of platinum within nanopores of porous silicon

    NARCIS (Netherlands)

    Munoz-Noval, Alvaro; Fukami, Kazuhiro; Koyama, Akira; Gallach, Dario; Hermida-Merino, Daniel; Portale, Giuseppe; Kitada, Atsushi; Murase, Kuniaki; Abe, Takeshi; Hayakawa, Shinjiro; Sakka, Tetsuo

    2016-01-01

    This study examined the formation of amorphous platinum (Pt) clusters in nanopores of porous silicon at an initial stage of pore filling. The time dependency of the chemical state and local structure of Pt in the nanoporous silicon were characterized by X-ray absorption fine structure spectroscopy (

  11. Large scale integration of flexible non-volatile, re-addressable memories using P(VDF-TrFE) and amorphous oxide transistors

    NARCIS (Netherlands)

    Gelinck, G.H.; Cobb, B.; Breemen, A.J.J.M. van; Myny, K.

    2015-01-01

    Ferroelectric polymers and amorphous metal oxide semiconductors have emerged as important materials for re-programmable non-volatile memories and high-performance, flexible thin-film transistors, respectively. However, realizing sophisticated transistor memory arrays has proven to be a challenge, an

  12. Application of Neutron-Absorbing Structural-Amorphous metal (SAM) Coatings for Spent Nuclear Fuel (SNF) Container to Enhance Criticality Safety Controls

    OpenAIRE

    Choi, J.; Lee, C.(Institute of Physics, Academia Sinica, Taipei, Taiwan); Farmer, J.; Day, D.; Wall, M.; Saw, C.; Boussoufi, M.; Liu, H.B.; Egbert, H.; Branagan, D.; D'Amato, A.

    2006-01-01

    Spent nuclear fuel contains fissionable materials (235U, 239Pu, 241Pu, etc.). To prevent nuclear criticality in spent fuel storage, transportation, and during disposal, neutron-absorbing materials (or neutron poisons, such as borated stainless steel, BoralTM, MetamicTM, Ni-Gd, and others) would have to be applied. The success in demonstrating that the High-Performance Corrosion- Resistant Material (HPCRM)1 can be thermally applied as coating onto base metal to provide for corrosion resistance...

  13. Fundamentals of amorphous solids structure and properties

    CERN Document Server

    Stachurski, Zbigniew H

    2014-01-01

    Long awaited, this textbook fills the gap for convincing concepts to describe amorphous solids. Adopting a unique approach, the author develops a framework that lays the foundations for a theory of amorphousness. He unravels the scientific mysteries surrounding the topic, replacing rather vague notions of amorphous materials as disordered crystalline solids with the well-founded concept of ideal amorphous solids. A classification of amorphous materials into inorganic glasses, organic glasses, glassy metallic alloys, and thin films sets the scene for the development of the model of ideal amorph

  14. Influence of varying metal-to-glass ratio on GMI effect in CoFeBSiCr amorphous glass-coated microwires

    Science.gov (United States)

    Qin, F. X.; Peng, H. X.; Phan, M. H.

    2010-01-01

    The influence of a varying metal-to-glass ratio on the GMI effect in amorphous glass-coated Co 70.3Fe 3.7B 10Si 13Cr 3 microwires has been investigated. In the range of frequencies investigated (1-10 MHz), the magnitude of the GMI effect increases as the metal-to-glass ratio (h) increases from 4.11 to 9.29. The GMI curves for the h=4.11 microwire exhibit a single-peak feature for f≤1 MHz and a double-peak feature for f>1 MHz, whereas a consistent double-peak feature is observed for microwires with h=8.07,8.72, and 9.29. The largest GMI effect is achieved for microwires with h=9.29. The anisotropy field (H), determined from GMI curves, increases with h=4.11 to h=8.07 and decreases when h>8.07. The calculated radial stress decreases as h increases from 4.11 to 9.29. These results provide further insights into the correlation between the GMI effect and microwire dimensions towards the GMI optimization of amorphous glass-coated magnetic microwires for sensor applications.

  15. High Performance Electronics on Flexible Silicon

    KAUST Repository

    Sevilla, Galo T.

    2016-09-01

    Over the last few years, flexible electronic systems have gained increased attention from researchers around the world because of their potential to create new applications such as flexible displays, flexible energy harvesters, artificial skin, and health monitoring systems that cannot be integrated with conventional wafer based complementary metal oxide semiconductor processes. Most of the current efforts to create flexible high performance devices are based on the use of organic semiconductors. However, inherent material\\'s limitations make them unsuitable for big data processing and high speed communications. The objective of my doctoral dissertation is to develop integration processes that allow the transformation of rigid high performance electronics into flexible ones while maintaining their performance and cost. In this work, two different techniques to transform inorganic complementary metal-oxide-semiconductor electronics into flexible ones have been developed using industry compatible processes. Furthermore, these techniques were used to realize flexible discrete devices and circuits which include metal-oxide-semiconductor field-effect-transistors, the first demonstration of flexible Fin-field-effect-transistors, and metal-oxide-semiconductors-based circuits. Finally, this thesis presents a new technique to package, integrate, and interconnect flexible high performance electronics using low cost additive manufacturing techniques such as 3D printing and inkjet printing. This thesis contains in depth studies on electrical, mechanical, and thermal properties of the fabricated devices.

  16. Strong Metal-Support Interaction: Growth of Individual Carbon Nanofibers from Amorphous Carbon Interacting with an Electron Beam

    DEFF Research Database (Denmark)

    Zhang, Wei; Kuhn, Luise Theil

    2013-01-01

    The article discusses the growth behavior of carbon nanofibers (CNFs). It mentions that CNFs can be synthesized using methods such as arc-discharge, laser ablation and chemical vapor deposition. It further states that CNFs can be grown from a physical mixing of amorphous carbon and CGO/Ni nanopar......The article discusses the growth behavior of carbon nanofibers (CNFs). It mentions that CNFs can be synthesized using methods such as arc-discharge, laser ablation and chemical vapor deposition. It further states that CNFs can be grown from a physical mixing of amorphous carbon and CGO....../Ni nanoparticles, devoid of any gaseous carbon source and external heating and stimulated by an electron beam in a 300 kilo volt transmission electron microscope....

  17. High Performance Thin Layer Chromatography.

    Science.gov (United States)

    Costanzo, Samuel J.

    1984-01-01

    Clarifies where in the scheme of modern chromatography high performance thin layer chromatography (TLC) fits and why in some situations it is a viable alternative to gas and high performance liquid chromatography. New TLC plates, sample applications, plate development, and instrumental techniques are considered. (JN)

  18. Evaluation of interactions between metal ions and nonionic surfactants in high-concentration HCl using low-pressure high-performance liquid chromatography with low-flow-resistance polystyrene-based monolithic column.

    Science.gov (United States)

    Hirano, Tomohiko; Kitagawa, Shinya; Ohtani, Hajime; Kinoshita, Takehiko; Ishigaki, Yuzo; Shibata, Nobuyuki; Nii, Susumu

    2013-10-01

    A method for evaluating the interactions between metal ions and nonionic surfactants in aqueous solutions containing high-concentration HCl, using gas pressure-driven low-pressure high-performance liquid chromatography (LP-HPLC) as a highly acid-resistant HPLC system, was developed. To construct the LP-HPLC for this purpose, poly(styrene-co-divinylbenzene)-based low-flow-resistance monolithic columns tolerant to highly acidic conditions were prepared using low-conversion thermal polymerization. Thermal polymerization at 65 °C for 1.5 h (monomer conversions, 33% for styrene and 59% for divinylbenzene) allowed preparation of a column with both high separation efficiency (around 60,000 plates m(-1) for alkylbenzenes) and a quite low back pressure of 0.14 MPa at a linear flow rate of 1 mm s(-1) (2.8 × 10(-13) m(2) in permeability). The base column prepared under the above conditions was coated with a nonionic surfactant, polyoxyethylene nonylphenyl ether (PONPE, average oxyethylene unit numbers (n) = 3, 7.5, 15, and 20), and used for evaluation of the interactions between PONPEs and metal ions in 6 M HCl. The interactions between PONPEs and Au(III), Ga(III), Fe(III), Zn(II), and Cu(II) were successfully evaluated using both breakthrough and chromatographic methods. Furthermore, a study of the effect of the polyoxyethylene (POE) chain length revealed that the use of PONPE with the longer POE moiety enhanced the magnitude of the interaction together with the increase in the amount of oxyethylene (OE) units coated on the monolith. Moreover, the interactions of metal ions with a single OE unit were almost constant in the range of n = 7.5-20, whereas the suppression of the interaction between Au(III) with the shortest PONPE chain (n = 3) was also observed. PMID:23884474

  19. 聚吡咯-过渡金属-氧配合物储锂材料的结构与性能研究%Polypyrrole-Transition Metal-Oxygen Coordination Complexes as High Performance Lithium Storage Material

    Institute of Scientific and Technical Information of China (English)

    毛亚; 孔庆宇; 郭炳焜; 王兆翔; 陈立泉

    2013-01-01

    Polypyrrole-transition metal-oxygen(PPy-M-O,where M=Fe and Co)coordination complexes have been chemically and electrochemically synthesized and proved to be a brand-new high-performance lithium-storage material.Extended X-ray absorption fine structure(EXAFS)spectroscopy and density functional theory(DFT)calculations indicate that both PPy-Fe-O and PPy-Co-O complexes share a similar multilayer structure.The strong and stable intralayer M(Fe,Co)-N coordination permits the material to possess high specific capacity.The high reversibility of its interlayer M-O-M interaction during cycling ensures high cycling stability and the conducting PPy matrix endows PPy-M-O with outstanding rate performance.Similar lithium storage performances have been obtained in other complexes containing conducting polymers and transition metals.These findings pave new ways to construct a new type of high-performance organic anode materials for lithium ion batteries,high-efficient and inexpensive electrocatalysts for fuel cells,supercapacitors and various other applications.%目前锂离子电池电极材料主要使用无机材料.近年来有机物电极材料虽有报道,但这些材料大都比容量低、倍率性能差.本文介绍一类新型有机金属配合物聚吡咯-过渡金属-氧储锂材料的合成、结构及电化学性能.结合扩展X-射线吸收精细结构谱分析和密度泛函理论计算,发现这类材料呈现多层结构特征,层内稳定的过渡金属-吡咯N的配位作用及循环过程中层间过渡金属-氧键的可逆断裂和结合使该类材料具有很高的储锂容量和循环稳定性,且聚吡咯导电网络使得该材料具有良好的倍率性能.这类新材料将有望成为锂离子电池的高比容量负极材料.

  20. Synthesis of Poly-Silicon Thin Films on Glass Substrate Using Laser Initiated Metal Induced Crystallization of Amorphous Silicon for Space Power Application

    Science.gov (United States)

    Abu-Safe, Husam H.; Naseem, Hameed A.; Brown, William D.

    2007-01-01

    Poly-silicon thin films on glass substrates are synthesized using laser initiated metal induced crystallization of hydrogenated amorphous silicon films. These films can be used to fabricate solar cells on low cost glass and flexible substrates. The process starts by depositing 200 nm amorphous silicon films on the glass substrates. Following this, 200 nm of sputtered aluminum films were deposited on top of the silicon layers. The samples are irradiated with an argon ion cw laser beam for annealing. Laser power densities ranging from 4 to 9 W/cm2 were used in the annealing process. Each area on the sample is irradiated for a different exposure time. Optical microscopy was used to examine any cracks in the films and loss of adhesion to the substrates. X-Ray diffraction patterns from the initial results indicated the crystallization in the films. Scanning electron microscopy shows dendritic growth. The composition analysis of the crystallized films was conducted using Energy Dispersive x-ray Spectroscopy. The results of poly-silicon films synthesis on space qualified flexible substrates such as Kapton are also presented.

  1. High Performance Space Pump Project

    Data.gov (United States)

    National Aeronautics and Space Administration — PDT is proposing a High Performance Space Pump based upon an innovative design using several technologies. The design will use a two-stage impeller, high...

  2. RavenDB high performance

    CERN Document Server

    Ritchie, Brian

    2013-01-01

    RavenDB High Performance is comprehensive yet concise tutorial that developers can use to.This book is for developers & software architects who are designing systems in order to achieve high performance right from the start. A basic understanding of RavenDB is recommended, but not required. While the book focuses on advanced topics, it does not assume that the reader has a great deal of prior knowledge of working with RavenDB.

  3. Enhanced off-resonance magnetoelectric response in laser annealed PZT thick film grown on magnetostrictive amorphous metal substrate

    International Nuclear Information System (INIS)

    A highly dense, 4 μm-thick Pb(Zr,Ti)O3 (PZT) film is deposited on amorphous magnetostrictive Metglas foil (FeBSi) by granule spray in vacuum process at room temperature, followed by its localized annealing with a continuous-wave 560 nm ytterbium fiber laser radiation. This longer-wavelength laser radiation is able to anneal the whole of thick PZT film layer without any deteriorative effects, such as chemical reaction and/or atomic diffusion, at the interface and crystallization of amorphous Metglas substrate. Greatly enhanced dielectric and ferroelectric properties of the annealed PZT are attributed to its better crystallinity and grain growth induced by laser irradiation. As a result, a colossal off-resonance magnetoelectric (ME) voltage coefficient that is two orders of magnitude larger than previously reported output from PZT/Metglas film-composites is achieved. The present work addresses the problems involved in the fabrication of PZT/Metglas film-composites and opens up emerging possibilities in employing piezoelectric materials with low thermal budget substrates (suitable for integrated electronics) and designing laminate composites for ME based devices

  4. Enhanced off-resonance magnetoelectric response in laser annealed PZT thick film grown on magnetostrictive amorphous metal substrate

    Energy Technology Data Exchange (ETDEWEB)

    Palneedi, Haribabu [Materials Interface Laboratory, Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701 (Korea, Republic of); Functional Ceramics Group, Korea Institute of Materials Science (KIMS), Changwon 641-831 (Korea, Republic of); Maurya, Deepam; Priya, Shashank [Bio-inspired Materials and Devices Laboratory (BMDL), Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061 (United States); Kim, Gi-Yeop; Choi, Si-Young, E-mail: youngchoi@kims.re.kr [Materials Modeling and Characterization Department, Korea Institute of Materials Science (KIMS), Changwon 641-831 (Korea, Republic of); Kang, Suk-Joong L. [Materials Interface Laboratory, Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701 (Korea, Republic of); Kim, Kwang-Ho [School of Materials Science and Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Ryu, Jungho, E-mail: jhryu@kims.re.kr [Functional Ceramics Group, Korea Institute of Materials Science (KIMS), Changwon 641-831 (Korea, Republic of)

    2015-07-06

    A highly dense, 4 μm-thick Pb(Zr,Ti)O{sub 3} (PZT) film is deposited on amorphous magnetostrictive Metglas foil (FeBSi) by granule spray in vacuum process at room temperature, followed by its localized annealing with a continuous-wave 560 nm ytterbium fiber laser radiation. This longer-wavelength laser radiation is able to anneal the whole of thick PZT film layer without any deteriorative effects, such as chemical reaction and/or atomic diffusion, at the interface and crystallization of amorphous Metglas substrate. Greatly enhanced dielectric and ferroelectric properties of the annealed PZT are attributed to its better crystallinity and grain growth induced by laser irradiation. As a result, a colossal off-resonance magnetoelectric (ME) voltage coefficient that is two orders of magnitude larger than previously reported output from PZT/Metglas film-composites is achieved. The present work addresses the problems involved in the fabrication of PZT/Metglas film-composites and opens up emerging possibilities in employing piezoelectric materials with low thermal budget substrates (suitable for integrated electronics) and designing laminate composites for ME based devices.

  5. Enhanced off-resonance magnetoelectric response in laser annealed PZT thick film grown on magnetostrictive amorphous metal substrate

    Science.gov (United States)

    Palneedi, Haribabu; Maurya, Deepam; Kim, Gi-Yeop; Priya, Shashank; Kang, Suk-Joong L.; Kim, Kwang-Ho; Choi, Si-Young; Ryu, Jungho

    2015-07-01

    A highly dense, 4 μm-thick Pb(Zr,Ti)O3 (PZT) film is deposited on amorphous magnetostrictive Metglas foil (FeBSi) by granule spray in vacuum process at room temperature, followed by its localized annealing with a continuous-wave 560 nm ytterbium fiber laser radiation. This longer-wavelength laser radiation is able to anneal the whole of thick PZT film layer without any deteriorative effects, such as chemical reaction and/or atomic diffusion, at the interface and crystallization of amorphous Metglas substrate. Greatly enhanced dielectric and ferroelectric properties of the annealed PZT are attributed to its better crystallinity and grain growth induced by laser irradiation. As a result, a colossal off-resonance magnetoelectric (ME) voltage coefficient that is two orders of magnitude larger than previously reported output from PZT/Metglas film-composites is achieved. The present work addresses the problems involved in the fabrication of PZT/Metglas film-composites and opens up emerging possibilities in employing piezoelectric materials with low thermal budget substrates (suitable for integrated electronics) and designing laminate composites for ME based devices.

  6. The investigation of ZnO:Al2O3/metal composite back reflectors in amorphous silicon germanium thin film solar cells

    Institute of Scientific and Technical Information of China (English)

    Wang Guang-Hong; Zhao Lei; Yan Bao-Jun; Chen Jing-Wei; Wang Ge; Diao Hong-Wei; Wang Wen-Jing

    2013-01-01

    Different aluminum-doped ZnO (AZO)/metal composite thin films,including AZO/Ag/Al,AZO/Ag/nickelchromium alloy (NiCr),and AZO/Ag/NiCr/Al,are utilized as the back reflectors of p-i-n amorphous silicon germanium thin film solar cells.NiCr is used as diffusion barrier layer between Ag and Al to prevent mutual diffusion,which increases the short circuit current density of solar cell.NiCr and NiCr/Al layers are used as protective layers of Ag layer against oxidation and sulfurization,the higher efficiency of solar cell is achieved.The experimental results show that the performance of a-SiGe solar cell with AZO/Ag/NiCr/Al back reflector is best.The initial conversion efficiency is achieved to be 8.05%.

  7. Removing and Recovering Phosphate from Poultry Wastewater Using Amorphous Ceramics

    OpenAIRE

    Youhui Xie; Qin Li; Xianzhi Zhao; Yi Luo; Yangming Wang; Xiangwei Peng; Qigui Wang; Jian Su; Yin Lu

    2014-01-01

    A novel and effective technique for phosphate from poultry wastewater was developed using amorphous ceramics. Amorphous ceramics, which showed high performance for phosphate removal and recovery from poultry wastewater, were synthesized using unlimitedly available, inexpensive materials such as silica fume and lime. Dissolved phosphate in poultry wastewater can be deposited as a solid on the surface of amorphous ceramics. Phosphate content on the surface of amorphous ceramics could reach 14.2...

  8. Development, Processing, and Testing of High-Performance Corrosion-Resistant HVOF Coatings

    International Nuclear Information System (INIS)

    New amorphous-metal and ceramic coatings applied by the high-velocity oxy-fuel (HVOF) process may reduce the waste package materials cost of the Yucca Mountain high-level nuclear waste repository by over $4 billion (cost reduction of 27 to 42%). Two critical requirements that have been determined from design analysis are protection in brines that may evolve from the evaporative concentration of pore waters and protection for waste package welds, thereby preventing exposure to environments that might cause stress corrosion cracking (SCC). Our efforts are directed towards producing and evaluating these high-performance coatings for the development of lower cost waste packages, and will leverage a cost-effective collaboration with DARPA for applications involving marine corrosion

  9. Effect of amorphous lamella on the crack propagation behavior of crystalline Mg/amorphous Mg-Al nanocomposites

    Science.gov (United States)

    Hai-Yang, Song; Yu-Long, Li

    2016-02-01

    The effects of amorphous lamella on the crack propagation behavior in crystalline/amorphous (C/A) Mg/Mg-Al nanocomposites under tensile loading are investigated using the molecular dynamics simulation method. The sample with an initial crack of orientation [0001] is considered here. For the nano-monocrystal Mg, the crack growth exhibits brittle cleavage. However, for the C/A Mg/Mg-Al nanocomposites, the ‘double hump’ behavior can be observed in all the stress-strain curves regardless of the amorphous lamella thickness. The results indicate that the amorphous lamella plays a critical role in the crack deformation, and it can effectively resist the crack propagation. The above mentioned crack deformation behaviors are also disclosed and analyzed in the present work. The results here provide a strategy for designing the high-performance hexagonal-close-packed metal and alloy materials. Project supported by the National Natural Science Foundation of China (Grant Nos. 11372256 and 11572259), the 111 Project (Grant No. B07050), the Program for New Century Excellent Talents in University of Ministry of Education of China (Grant No. NCET-12-1046), and the Program for New Scientific and Technological Star of Shaanxi Province, China (Grant No. 2012KJXX-39).

  10. INL High Performance Building Strategy

    Energy Technology Data Exchange (ETDEWEB)

    Jennifer D. Morton

    2010-02-01

    High performance buildings, also known as sustainable buildings and green buildings, are resource efficient structures that minimize the impact on the environment by using less energy and water, reduce solid waste and pollutants, and limit the depletion of natural resources while also providing a thermally and visually comfortable working environment that increases productivity for building occupants. As Idaho National Laboratory (INL) becomes the nation’s premier nuclear energy research laboratory, the physical infrastructure will be established to help accomplish this mission. This infrastructure, particularly the buildings, should incorporate high performance sustainable design features in order to be environmentally responsible and reflect an image of progressiveness and innovation to the public and prospective employees. Additionally, INL is a large consumer of energy that contributes to both carbon emissions and resource inefficiency. In the current climate of rising energy prices and political pressure for carbon reduction, this guide will help new construction project teams to design facilities that are sustainable and reduce energy costs, thereby reducing carbon emissions. With these concerns in mind, the recommendations described in the INL High Performance Building Strategy (previously called the INL Green Building Strategy) are intended to form the INL foundation for high performance building standards. This revised strategy incorporates the latest federal and DOE orders (Executive Order [EO] 13514, “Federal Leadership in Environmental, Energy, and Economic Performance” [2009], EO 13423, “Strengthening Federal Environmental, Energy, and Transportation Management” [2007], and DOE Order 430.2B, “Departmental Energy, Renewable Energy, and Transportation Management” [2008]), the latest guidelines, trends, and observations in high performance building construction, and the latest changes to the Leadership in Energy and Environmental Design

  11. Iron-based amorphous alloys and methods of synthesizing iron-based amorphous alloys

    Energy Technology Data Exchange (ETDEWEB)

    Saw, Cheng Kiong; Bauer, William A.; Choi, Jor-Shan; Day, Dan; Farmer, Joseph C.

    2016-05-03

    A method according to one embodiment includes combining an amorphous iron-based alloy and at least one metal selected from a group consisting of molybdenum, chromium, tungsten, boron, gadolinium, nickel phosphorous, yttrium, and alloys thereof to form a mixture, wherein the at least one metal is present in the mixture from about 5 atomic percent (at %) to about 55 at %; and ball milling the mixture at least until an amorphous alloy of the iron-based alloy and the at least one metal is formed. Several amorphous iron-based metal alloys are also presented, including corrosion-resistant amorphous iron-based metal alloys and radiation-shielding amorphous iron-based metal alloys.

  12. High-Performance Ball Bearing

    Science.gov (United States)

    Bursey, Roger W., Jr.; Haluck, David A.; Olinger, John B.; Owen, Samuel S.; Poole, William E.

    1995-01-01

    High-performance bearing features strong, lightweight, self-lubricating cage with self-lubricating liners in ball apertures. Designed to operate at high speed (tens of thousands of revolutions per minute) in cryogenic environment like liquid-oxygen or liquid-hydrogen turbopump. Includes inner race, outer race, and cage keeping bearing balls equally spaced.

  13. High-Performance Operating Systems

    DEFF Research Database (Denmark)

    Sharp, Robin

    1999-01-01

    Notes prepared for the DTU course 49421 "High Performance Operating Systems". The notes deal with quantitative and qualitative techniques for use in the design and evaluation of operating systems in computer systems for which performance is an important parameter, such as real-time applications......, communication systems and multimedia systems....

  14. High Performance Bulk Thermoelectric Materials

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Zhifeng [Boston College, Chestnut Hill, MA (United States)

    2013-03-31

    Over 13 plus years, we have carried out research on electron pairing symmetry of superconductors, growth and their field emission property studies on carbon nanotubes and semiconducting nanowires, high performance thermoelectric materials and other interesting materials. As a result of the research, we have published 104 papers, have educated six undergraduate students, twenty graduate students, nine postdocs, nine visitors, and one technician.

  15. Formation of quasicrystals and amorphous-to-quasicrystalline phase transformation kinetics in Zr65Al7.5Ni10Cu7.5Ag10 metallic glass under pressure

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Zhuang, Yanxin; Rasmussen, Helge Kildahl;

    2001-01-01

    of quasicrystals decrease, Atomic mobility is important for the formation of quasicrystals from the metallic glass whereas the relationship of the crystallization temperature vs pressure for the transition from the quasicrystalline state to intermetallic compounds may mainly depend on the thermodynamic potential......The effect of pressure on the formation of quasicrystals and the amorphous-to-quasicrystalline phase transformation kinetics in the supercooled liquid region for a Zr65Al7.5Ni10Cu7.5Ag10 metallic glass have been investigated by in situ high-pressure and high-temperature nonisothermal and isothermal...... energy barrier. To study the amorphous-to-quasicrystalline phase transformation kinetics in the metallic glass, relative volume fractions of the transferred quasicrystalline phase as a function of annealing time, obtained at 663, 673, 683, and 693 K, have been analyzed in details using 14 nucleation...

  16. High performance in software development

    CERN Document Server

    CERN. Geneva; Haapio, Petri; Liukkonen, Juha-Matti

    2015-01-01

    What are the ingredients of high-performing software? Software development, especially for large high-performance systems, is one the most complex tasks mankind has ever tried. Technological change leads to huge opportunities but challenges our old ways of working. Processing large data sets, possibly in real time or with other tight computational constraints, requires an efficient solution architecture. Efficiency requirements span from the distributed storage and large-scale organization of computation and data onto the lowest level of processor and data bus behavior. Integrating performance behavior over these levels is especially important when the computation is resource-bounded, as it is in numerics: physical simulation, machine learning, estimation of statistical models, etc. For example, memory locality and utilization of vector processing are essential for harnessing the computing power of modern processor architectures due to the deep memory hierarchies of modern general-purpose computers. As a r...

  17. High performance scalable image coding

    Institute of Scientific and Technical Information of China (English)

    Gan Tao; He Yanmin; Zhu Weile

    2007-01-01

    A high performance scalable image coding algorithm is proposed. The salient features of this algorithm are the ways to form and locate the significant clusters. Thanks to the list structure, the new coding algorithm achieves fine fractional bit-plane coding with negligible additional complexity. Experiments show that it performs comparably or better than the state-of-the-art coders. Furthermore, the flexible codec supports both quality and resolution scalability, which is very attractive in many network applications.

  18. Neo4j high performance

    CERN Document Server

    Raj, Sonal

    2015-01-01

    If you are a professional or enthusiast who has a basic understanding of graphs or has basic knowledge of Neo4j operations, this is the book for you. Although it is targeted at an advanced user base, this book can be used by beginners as it touches upon the basics. So, if you are passionate about taming complex data with the help of graphs and building high performance applications, you will be able to get valuable insights from this book.

  19. High performance dielectric materials development

    Science.gov (United States)

    Piche, Joe; Kirchner, Ted; Jayaraj, K.

    1994-01-01

    The mission of polymer composites materials technology is to develop materials and processing technology to meet DoD and commercial needs. The following are outlined in this presentation: high performance capacitors, high temperature aerospace insulation, rationale for choosing Foster-Miller (the reporting industry), the approach to the development and evaluation of high temperature insulation materials, and the requirements/evaluation parameters. Supporting tables and diagrams are included.

  20. Identifying High Performance ERP Projects

    OpenAIRE

    Stensrud, Erik; Myrtveit, Ingunn

    2002-01-01

    Learning from high performance projects is crucial for software process improvement. Therefore, we need to identify outstanding projects that may serve as role models. It is common to measure productivity as an indicator of performance. It is vital that productivity measurements deal correctly with variable returns to scale and multivariate data. Software projects generally exhibit variable returns to scale, and the output from ERP projects is multivariate. We propose to use Data Envelopment ...

  1. FUNDAMENTALS OF HIGH PERFORMANCE ORGANIZATIONS.

    OpenAIRE

    Maria Lúcia Gili Massi

    2013-01-01

    The objective of this article is to verify whether organizations’ high performance rests on their culture, which adjusts their cultural values, strategy, and external environment. A strong organizational culture has been reported as determinant of organizations’ performance. These studies approach the influence of values guiding and adjusting the organization’s strategic actions regarding its external environment. The bibliographic research showed that there are other variables impacting of o...

  2. Carbohydrate-Assisted Combustion Synthesis To Realize High-Performance Oxide Transistors.

    Science.gov (United States)

    Wang, Binghao; Zeng, Li; Huang, Wei; Melkonyan, Ferdinand S; Sheets, William C; Chi, Lifeng; Bedzyk, Michael J; Marks, Tobin J; Facchetti, Antonio

    2016-06-01

    Owing to high carrier mobilities, good environmental/thermal stability, excellent optical transparency, and compatibility with solution processing, thin-film transistors (TFTs) based on amorphous metal oxide semiconductors (AOSs) are promising alternatives to those based on amorphous silicon (a-Si:H) and low-temperature (LTPS). However, solution-processed display-relevant indium-gallium-tin-oxide (IGZO) TFTs suffer from low carrier mobilities and/or inferior bias-stress stability versus their sputtered counterparts. Here we report that three types of environmentally benign carbohydrates (sorbitol, sucrose, and glucose) serve as especially efficient fuels for IGZO film combustion synthesis to yield high-performance TFTs. The results indicate that these carbohydrates assist the combustion process by lowering the ignition threshold temperature and, for optimal stoichiometries, enhancing the reaction enthalpy. IGZO TFT mobilities are increased to >8 cm(2) V(-1) s(-1) on SiO2/Si gate dielectrics with significantly improved bias-stress stability. The first correlations between precursor combustion enthalpy and a-MO densification/charge transport are established. PMID:27168054

  3. High Performance Tools And Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Collette, M R; Corey, I R; Johnson, J R

    2005-01-24

    This goal of this project was to evaluate the capability and limits of current scientific simulation development tools and technologies with specific focus on their suitability for use with the next generation of scientific parallel applications and High Performance Computing (HPC) platforms. The opinions expressed in this document are those of the authors, and reflect the authors' current understanding and functionality of the many tools investigated. As a deliverable for this effort, we are presenting this report describing our findings along with an associated spreadsheet outlining current capabilities and characteristics of leading and emerging tools in the high performance computing arena. This first chapter summarizes our findings (which are detailed in the other chapters) and presents our conclusions, remarks, and anticipations for the future. In the second chapter, we detail how various teams in our local high performance community utilize HPC tools and technologies, and mention some common concerns they have about them. In the third chapter, we review the platforms currently or potentially available to utilize these tools and technologies on to help in software development. Subsequent chapters attempt to provide an exhaustive overview of the available parallel software development tools and technologies, including their strong and weak points and future concerns. We categorize them as debuggers, memory checkers, performance analysis tools, communication libraries, data visualization programs, and other parallel development aides. The last chapter contains our closing information. Included with this paper at the end is a table of the discussed development tools and their operational environment.

  4. Researches on the electrolysis of metal oxides dissolved in boric anhydride or in melt borates. New methods of preparation of amorphous boron, borides and some metals

    International Nuclear Information System (INIS)

    This research thesis reports the investigation of the electrolysis of alkaline borates, alkaline earth borates and magnesium borate, and the investigation of mixtures containing a metal oxide dissolved in a bath formed by a tetraborate and a fluoride. The author more particularly studies the chemical products separated at the cathode level, i.e. boron (more or less pure), borates and other metals (zinc, tungsten, molybdenum)

  5. FUNDAMENTALS OF HIGH PERFORMANCE ORGANIZATIONS.

    Directory of Open Access Journals (Sweden)

    Maria Lúcia Gili Massi

    2013-06-01

    Full Text Available The objective of this article is to verify whether organizations’ high performance rests on their culture, which adjusts their cultural values, strategy, and external environment. A strong organizational culture has been reported as determinant of organizations’ performance. These studies approach the influence of values guiding and adjusting the organization’s strategic actions regarding its external environment. The bibliographic research showed that there are other variables impacting of organizations’ performance and it was concluded that the objective of this study was partially achieved.

  6. Optimization of the absorption efficiency of an amorphous-silicon thin-film tandem solar cell backed by a metallic surface-relief grating.

    Science.gov (United States)

    Solano, Manuel; Faryad, Muhammad; Hall, Anthony S; Mallouk, Thomas E; Monk, Peter B; Lakhtakia, Akhlesh

    2013-02-10

    The rigorous coupled-wave approach was used to compute the plane-wave absorptance of a thin-film tandem solar cell with a metallic surface-relief grating as its back reflector. The absorptance is a function of the angle of incidence and the polarization state of incident light; the free-space wavelength; and the period, duty cycle, the corrugation height, and the shape of the unit cell of the surface-relief grating. The solar cell was assumed to be made of hydrogenated amorphous-silicon alloys and the back reflector of bulk aluminum. The incidence and the grating planes were taken to be identical. The AM1.5 solar irradiance spectrum was used for computations in the 400-1100 nm wavelength range. Inspection of parametric plots of the solar-spectrum-integrated (SSI) absorption efficiency and numerical optimization using the differential evolution algorithm were employed to determine the optimal surface-relief grating. For direct insolation, the SSI absorption efficiency is maximizable by appropriate choices of the period, the duty cycle, and the corrugation height, regardless of the shape of the corrugation in each unit cell of the grating. A similar conclusion also holds for diffuse insolation, but the maximum efficiency for diffuse insolation is about 20% smaller than for direct insolation. Although a tin-doped indium-oxide layer at the front and an aluminum-doped zinc-oxide layer between the semiconductor material and the backing metallic layer change the optimal depth of the periodic corrugations, the optimal period of the corrugations does not significantly change. PMID:23400058

  7. High performance dispersion model PHYSIC

    Energy Technology Data Exchange (ETDEWEB)

    Yamazawa, Hiromi (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment)

    1992-07-01

    The description and usage of the dispersion calculation model PHYSIC were summarized. The model was developed in the study of developing high performance SPEEDI with the purpose of introducing meteorological forecast function into the environmental emergency response system. PHYSIC consists of two parts, the three-dimensional meteorological model and the dispersion model. The former comprises primitive equations with Boussinesq approximation, which are solved by a finite difference method. The latter employs a particle dispersion method. PHYSIC can be used to evaluate the meteorological condition as well as the dispersion from a point source located in a complex terrain. The spatial and temporal scales of the model are 10 to 1000 km horizontally, 1 to 10 km vertically and 1 hour to 1 day, respectively. (author).

  8. AMORPHOUS COATING FORMING IN THE CONDITIONS OF GAS THERMAL SPRAYING

    Directory of Open Access Journals (Sweden)

    V. V. Artemchuk

    2010-06-01

    Full Text Available In the article the issues of forming amorphous coatings in the conditions of gas thermal spraying of coating are considered. On the basis of theoretical analysis the technological factors, determining possibility of obtaining the amorphous coatings at detonation spraying, are formulated. Two groups of factors, influencing on formation of amorphous structure in detonation sprayed coatings from metallic alloys, are marked.

  9. On Structure and Properties of Amorphous Materials

    Directory of Open Access Journals (Sweden)

    Zbigniew H. Stachurski

    2011-09-01

    Full Text Available Mechanical, optical, magnetic and electronic properties of amorphous materials hold great promise towards current and emergent technologies. We distinguish at least four categories of amorphous (glassy materials: (i metallic; (ii thin films; (iii organic and inorganic thermoplastics; and (iv amorphous permanent networks. Some fundamental questions about the atomic arrangements remain unresolved. This paper focuses on the models of atomic arrangements in amorphous materials. The earliest ideas of Bernal on the structure of liquids were followed by experiments and computer models for the packing of spheres. Modern approach is to carry out computer simulations with prediction that can be tested by experiments. A geometrical concept of an ideal amorphous solid is presented as a novel contribution to the understanding of atomic arrangements in amorphous solids.

  10. High Performance Proactive Digital Forensics

    International Nuclear Information System (INIS)

    With the increase in the number of digital crimes and in their sophistication, High Performance Computing (HPC) is becoming a must in Digital Forensics (DF). According to the FBI annual report, the size of data processed during the 2010 fiscal year reached 3,086 TB (compared to 2,334 TB in 2009) and the number of agencies that requested Regional Computer Forensics Laboratory assistance increasing from 689 in 2009 to 722 in 2010. Since most investigation tools are both I/O and CPU bound, the next-generation DF tools are required to be distributed and offer HPC capabilities. The need for HPC is even more evident in investigating crimes on clouds or when proactive DF analysis and on-site investigation, requiring semi-real time processing, are performed. Although overcoming the performance challenge is a major goal in DF, as far as we know, there is almost no research on HPC-DF except for few papers. As such, in this work, we extend our work on the need of a proactive system and present a high performance automated proactive digital forensic system. The most expensive phase of the system, namely proactive analysis and detection, uses a parallel extension of the iterative z algorithm. It also implements new parallel information-based outlier detection algorithms to proactively and forensically handle suspicious activities. To analyse a large number of targets and events and continuously do so (to capture the dynamics of the system), we rely on a multi-resolution approach to explore the digital forensic space. Data set from the Honeynet Forensic Challenge in 2001 is used to evaluate the system from DF and HPC perspectives.

  11. High Performance Proactive Digital Forensics

    Science.gov (United States)

    Alharbi, Soltan; Moa, Belaid; Weber-Jahnke, Jens; Traore, Issa

    2012-10-01

    With the increase in the number of digital crimes and in their sophistication, High Performance Computing (HPC) is becoming a must in Digital Forensics (DF). According to the FBI annual report, the size of data processed during the 2010 fiscal year reached 3,086 TB (compared to 2,334 TB in 2009) and the number of agencies that requested Regional Computer Forensics Laboratory assistance increasing from 689 in 2009 to 722 in 2010. Since most investigation tools are both I/O and CPU bound, the next-generation DF tools are required to be distributed and offer HPC capabilities. The need for HPC is even more evident in investigating crimes on clouds or when proactive DF analysis and on-site investigation, requiring semi-real time processing, are performed. Although overcoming the performance challenge is a major goal in DF, as far as we know, there is almost no research on HPC-DF except for few papers. As such, in this work, we extend our work on the need of a proactive system and present a high performance automated proactive digital forensic system. The most expensive phase of the system, namely proactive analysis and detection, uses a parallel extension of the iterative z algorithm. It also implements new parallel information-based outlier detection algorithms to proactively and forensically handle suspicious activities. To analyse a large number of targets and events and continuously do so (to capture the dynamics of the system), we rely on a multi-resolution approach to explore the digital forensic space. Data set from the Honeynet Forensic Challenge in 2001 is used to evaluate the system from DF and HPC perspectives.

  12. Homogeneous Plastic Flow of Fully Amorphous and Partially Crystallized Zr41.2Ti13.8Cu12.5Ni10Be22.5 Bulk Metallic Glass

    Institute of Scientific and Technical Information of China (English)

    Q.WANG; J.J. Blandin; M. Suery; B. Van de Moortéle; J.M. Pelletier

    2003-01-01

    The homogeneous plastic flow of fully amorphous and partially crystallized Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk metallic glass (Vit1) has been investigated by compression tests at high temperatures in supercooled liquid region. Experimental results show that at sufficiently low strain rates, the supercooled liquid of the fully amorphous alloy reveals Newtonian flow with a linear relationship between the flow stress and strain rate. As the strain rate is increased, a transition from linear Newtonian to nonlinear flow is detected, which can be explained by the transition state theory.Over the entire strain rate interval investigated, however, only nonlinear flow is present in the partially crystallized alloy, and the flow stress for each strain rate is much higher. It is found that the strain rate-stress relationship for the partially crystallized alloy at the given temperature of 646 K also obeys the sinh law derived from the transition state theory, similar to that of the initial homogeneous amorphous alloy. Thus, it is proposed that the flow behavior of the nanocrystalline/amorphous composite at 646 K is mainly controlled by the viscous flow of the remaining supercooled liquid.

  13. Amorphous Alloy Surpasses Steel and Titanium

    Science.gov (United States)

    2004-01-01

    In the same way that the inventions of steel in the 1800s and plastic in the 1900s sparked revolutions for industry, a new class of amorphous alloys is poised to redefine materials science as we know it in the 21st century. Welcome to the 3rd Revolution, otherwise known as the era of Liquidmetal(R) alloys, where metals behave similar to plastics but possess more than twice the strength of high performance titanium. Liquidmetal alloys were conceived in 1992, as a result of a project funded by the California Institute of Technology (CalTech), NASA, and the U.S. Department of Energy, to study the fundamentals of metallic alloys in an undercooled liquid state, for the development of new aerospace materials. Furthermore, NASA's Marshall Space Flight Center contributed to the development of the alloys by subjecting the materials to testing in its Electrostatic Levitator, a special instrument that is capable of suspending an object in midair so that researchers can heat and cool it in a containerless environment free from contaminants that could otherwise spoil the experiment.

  14. High performance railgun barrels for laboratory use

    Science.gov (United States)

    Bauer, David P.; Newman, Duane C.

    1993-01-01

    High performance low-cost, laboratory railgun barrels are now available, comprised of an inherently stiff containment structure which surrounds the bore components machined from 'off the-shelf' materials. The shape of the containment structure was selected to make the barrel inherently stiff. The structure consists of stainless steel laminations which do not compromise the electrical efficiency of the railgun. The modular design enhances the utility of the barrel, as it is easy to service between shots, and can be 're-cored' to produce different configurations and sizes using the same structure. We have produced barrels ranging from 15 mm to 90 mm square bore, a 30 mm round bore, and in lengths varying from 0.25 meters to 10 meters long. Successful tests with both plasma and solid metal armatures have demonstrated the versatility and performance of this design.

  15. Iron - based bulk amorphous alloys

    Directory of Open Access Journals (Sweden)

    R. Babilas

    2010-07-01

    Full Text Available Purpose: The paper presents a structure characterization, thermal and soft magnetic properties analysis of Fe-based bulk amorphous materials in as-cast state and after crystallization process. In addition, the paper gives some brief review about achieving, formation and structure of bulk metallic glasses as a special group of amorphous materials.Design/methodology/approach: The studies were performed on Fe72B20Si4Nb4 metallic glass in form of ribbons and rods. The amorphous structure of tested samples was examined by X-ray diffraction (XRD, transmission electron microscopy (TEM and scanning electron microscopy (SEM methods. The thermal properties of the glassy samples were measured using differential thermal analysis (DTA and differential scanning calorimetry (DSC. The magnetic properties contained initial and maximum magnetic permeability, coercive force and magnetic after-effects measurements were determined by the Maxwell-Wien bridge and VSM methods.Findings: The X-ray diffraction and transmission electron microscopy investigations revealed that the studied as-cast bulk metallic glasses in form of ribbons and rods were amorphous. Two stage crystallization process was observed for studied bulk amorphous alloy. The differences of crystallization temperature between ribbons and rods with chosen thickness are probably caused by different amorphous structures as a result of the different cooling rates in casting process. The SEM images showed that studied fractures could be classified as mixed fractures with indicated two zones contained “river” and “smooth” areas. The changing of chosen soft magnetic properties (μr, Bs, Hc obtained for samples with different thickness is a result of the non-homogenous amorphous structure of tested metallic glasses. The annealing process in temperature range from 373 to 773 K causes structural relaxation of tested amorphous materials, which leads to changes in their physical properties. The qualitative

  16. HIGH-PERFORMANCE COATING MATERIALS

    Energy Technology Data Exchange (ETDEWEB)

    SUGAMA,T.

    2007-01-01

    Corrosion, erosion, oxidation, and fouling by scale deposits impose critical issues in selecting the metal components used at geothermal power plants operating at brine temperatures up to 300 C. Replacing these components is very costly and time consuming. Currently, components made of titanium alloy and stainless steel commonly are employed for dealing with these problems. However, another major consideration in using these metals is not only that they are considerably more expensive than carbon steel, but also the susceptibility of corrosion-preventing passive oxide layers that develop on their outermost surface sites to reactions with brine-induced scales, such as silicate, silica, and calcite. Such reactions lead to the formation of strong interfacial bonds between the scales and oxide layers, causing the accumulation of multiple layers of scales, and the impairment of the plant component's function and efficacy; furthermore, a substantial amount of time is entailed in removing them. This cleaning operation essential for reusing the components is one of the factors causing the increase in the plant's maintenance costs. If inexpensive carbon steel components could be coated and lined with cost-effective high-hydrothermal temperature stable, anti-corrosion, -oxidation, and -fouling materials, this would improve the power plant's economic factors by engendering a considerable reduction in capital investment, and a decrease in the costs of operations and maintenance through optimized maintenance schedules.

  17. High-Performance Bipropellant Engine

    Science.gov (United States)

    Biaglow, James A.; Schneider, Steven J.

    1999-01-01

    TRW, under contract to the NASA Lewis Research Center, has successfully completed over 10 000 sec of testing of a rhenium thrust chamber manufactured via a new-generation powder metallurgy. High performance was achieved for two different propellants, N2O4- N2H4 and N2O4 -MMH. TRW conducted 44 tests with N2O4-N2H4, accumulating 5230 sec of operating time with maximum burn times of 600 sec and a specific impulse Isp of 333 sec. Seventeen tests were conducted with N2O4-MMH for an additional 4789 sec and a maximum Isp of 324 sec, with a maximum firing duration of 700 sec. Together, the 61 tests totalled 10 019 sec of operating time, with the chamber remaining in excellent condition. Of these tests, 11 lasted 600 to 700 sec. The performance of radiation-cooled rocket engines is limited by their operating temperature. For the past two to three decades, the majority of radiation-cooled rockets were composed of a high-temperature niobium alloy (C103) with a disilicide oxide coating (R512) for oxidation resistance. The R512 coating practically limits the operating temperature to 1370 C. For the Earth-storable bipropellants commonly used in satellite and spacecraft propulsion systems, a significant amount of fuel film cooling is needed. The large film-cooling requirement extracts a large penalty in performance from incomplete mixing and combustion. A material system with a higher temperature capability has been matured to the point where engines are being readied for flight, particularly the 100-lb-thrust class engine. This system has powder rhenium (Re) as a substrate material with an iridium (Ir) oxidation-resistant coating. Again, the operating temperature is limited by the coating; however, Ir is capable of long-life operation at 2200 C. For Earth-storable bipropellants, this allows for the virtual elimination of fuel film cooling (some film cooling is used for thermal control of the head end). This has resulted in significant increases in specific impulse performance

  18. Inorganic nanostructured materials for high performance electrochemical supercapacitors.

    Science.gov (United States)

    Liu, Sheng; Sun, Shouheng; You, Xiao-Zeng

    2014-02-21

    Electrochemical supercapacitors (ES) are a well-known energy storage system that has high power density, long life-cycle and fast charge-discharge kinetics. Nanostructured materials are a new generation of electrode materials with large surface area and short transport/diffusion path for ions and electrons to achieve high specific capacitance in ES. This mini review highlights recent developments of inorganic nanostructure materials, including carbon nanomaterials, metal oxide nanoparticles, and metal oxide nanowires/nanotubes, for high performance ES applications.

  19. Powder metallurgical high performance materials. Proceedings. Volume 3: general topics

    International Nuclear Information System (INIS)

    The proceedings of these seminars form an impressive chronicle of the continued progress in the understanding of refractory metals and cemented carbides and in their manufacture and application. The 15th Plansee Seminar was convened under the general theme 'Powder Metallurgy High Performance Materials'. Under this broadened perspective the seminar will strive to look beyond the refractory metals and cemented carbides, which remain at its focus, to novel classes of materials, such as intermetallic compounds, with potential for high temperature applications. (boteke)

  20. Inorganic nanostructured materials for high performance electrochemical supercapacitors

    Science.gov (United States)

    Liu, Sheng; Sun, Shouheng; You, Xiao-Zeng

    2014-01-01

    Electrochemical supercapacitors (ES) are a well-known energy storage system that has high power density, long life-cycle and fast charge-discharge kinetics. Nanostructured materials are a new generation of electrode materials with large surface area and short transport/diffusion path for ions and electrons to achieve high specific capacitance in ES. This mini review highlights recent developments of inorganic nanostructure materials, including carbon nanomaterials, metal oxide nanoparticles, and metal oxide nanowires/nanotubes, for high performance ES applications.

  1. High performance MEAs. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-15

    The aim of the present project is through modeling, material and process development to obtain significantly better MEA performance and to attain the technology necessary to fabricate stable catalyst materials thereby providing a viable alternative to current industry standard. This project primarily focused on the development and characterization of novel catalyst materials for the use in high temperature (HT) and low temperature (LT) proton-exchange membrane fuel cells (PEMFC). New catalysts are needed in order to improve fuel cell performance and reduce the cost of fuel cell systems. Additional tasks were the development of new, durable sealing materials to be used in PEMFC as well as the computational modeling of heat and mass transfer processes, predominantly in LT PEMFC, in order to improve fundamental understanding of the multi-phase flow issues and liquid water management in fuel cells. An improved fundamental understanding of these processes will lead to improved fuel cell performance and hence will also result in a reduced catalyst loading to achieve the same performance. The consortium have obtained significant research results and progress for new catalyst materials and substrates with promising enhanced performance and fabrication of the materials using novel methods. However, the new materials and synthesis methods explored are still in the early research and development phase. The project has contributed to improved MEA performance using less precious metal and has been demonstrated for both LT-PEM, DMFC and HT-PEM applications. New novel approach and progress of the modelling activities has been extremely satisfactory with numerous conference and journal publications along with two potential inventions concerning the catalyst layer. (LN)

  2. Carpet Aids Learning in High Performance Schools

    Science.gov (United States)

    Hurd, Frank

    2009-01-01

    The Healthy and High Performance Schools Act of 2002 has set specific federal guidelines for school design, and developed a federal/state partnership program to assist local districts in their school planning. According to the Collaborative for High Performance Schools (CHPS), high-performance schools are, among other things, healthy, comfortable,…

  3. High-Performance Schools Make Cents.

    Science.gov (United States)

    Nielsen-Palacios, Christian

    2003-01-01

    Describes the educational benefits of high-performance schools, buildings that are efficient, healthy, safe, and easy to operate and maintain. Also briefly describes how to create a high-performance school drawn from volume I (Planning) of the three-volume Collaborative for High Performance Schools (CHPS) "Best Practices Manual." (For more…

  4. Electrochemical Studies of Passive Film Stability on Fe48Mo14Cr15Y2C15B Amorphous Metal in Seawater at 90oC and 5M CaCl2 at 105oC

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J C; Day, S D; Lian, T; Saw, C K; Hailey, P D; Blue, C A; Peters, W; Payer, J H; Perepezko, J H; Hildal, K; Branagan, D J; Buffa, E J; Aprigliano, L

    2007-04-25

    Several Fe-based amorphous metal formulations have been identified that appear to have corrosion resistance comparable to, or better than that of Ni-based Alloy C-22 (UNS N06022), based on measurements of breakdown potential and corrosion rate in seawater. Both chromium (Cr) and molybdenum (Mo) provide corrosion resistance, boron (B) enables glass formation, and rare earths such as yttrium (Y) lower critical cooling rate (CCR). Amorphous Fe{sub 48.0}Cr{sub 15.0}Mo{sub 14.0}B{sub 6.0}C{sub 15.0}Y{sub 2.0} (SAM1651) has a low critical cooling rate (CCR) of less than 80 Kelvin per second, due to the addition of yttrium. The low CCR enables it to be rendered as a completely amorphous material in practical materials processes. While the yttrium enables a low CCR to be achieved, it makes the material relatively difficult to atomize, due to increases in melt viscosity. Consequently, the powders produced thus far have had irregular shape, which had made pneumatic conveyance during thermal spray deposition difficult.

  5. Fabricating high performance lithium-ion batteries using bionanotechnology

    Science.gov (United States)

    Zhang, Xudong; Hou, Yukun; He, Wen; Yang, Guihua; Cui, Jingjie; Liu, Shikun; Song, Xin; Huang, Zhen

    2015-02-01

    Designing, fabricating, and integrating nanomaterials are key to transferring nanoscale science into applicable nanotechnology. Many nanomaterials including amorphous and crystal structures are synthesized via biomineralization in biological systems. Amongst various techniques, bionanotechnology is an effective strategy to manufacture a variety of sophisticated inorganic nanomaterials with precise control over their chemical composition, crystal structure, and shape by means of genetic engineering and natural bioassemblies. This provides opportunities to use renewable natural resources to develop high performance lithium-ion batteries (LIBs). For LIBs, reducing the sizes and dimensions of electrode materials can boost Li+ ion and electron transfer in nanostructured electrodes. Recently, bionanotechnology has attracted great interest as a novel tool and approach, and a number of renewable biotemplate-based nanomaterials have been fabricated and used in LIBs. In this article, recent advances and mechanism studies in using bionanotechnology for high performance LIBs studies are thoroughly reviewed, covering two technical routes: (1) Designing and synthesizing composite cathodes, e.g. LiFePO4/C, Li3V2(PO4)3/C and LiMn2O4/C; and (2) designing and synthesizing composite anodes, e.g. NiO/C, Co3O4/C, MnO/C, α-Fe2O3 and nano-Si. This review will hopefully stimulate more extensive and insightful studies on using bionanotechnology for developing high-performance LIBs.

  6. Ferroelectric switching of poly(vinylidene difluoride-trifluoroethylene) in metal-ferroelectric-semiconductor non-volatile memories with an amorphous oxide semiconductor

    NARCIS (Netherlands)

    Gelinck, G.H.; Breemen, A.J.J.M. van; Cobb, B.

    2015-01-01

    Ferroelectric polarization switching of poly(vinylidene difluoride-trifluoroethylene) is investigated in different thin-film device structures, ranging from simple capacitors to dual-gate thin-film transistors (TFT). Indium gallium zinc oxide, a high mobility amorphous oxide material, is used as sem

  7. Complex Amorphous Dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    van Dover, Robert Bruce [Cornell Univ., Ithaca, NY (United States)

    2014-11-22

    This work focused on synthesizing a wide range of oxides containing two or more metals, and measuring their properties. Many simple metal oxides such as zirconium oxide, have been extensively studied in the past. We developed a technique in which we create a large number of compositions simultaneously and examine their behavior to understand trends and identify high performance materials. Superior performance generally comes in the form of increased responsiveness; in the materials we have studied this may mean more electrical charge for a given voltage in a capacitor, faster switching for a given drive in a transistor, more current for a given voltage in an ionic conductor, or more current for a given illumination in a solar cell. Some of the materials we have identified may find use in decreasing the power needed to operate integrated circuits, other materials could be useful for solar power or other forms of energy conversion.

  8. Attaining High Performance Communications A Vertical Approach

    CERN Document Server

    Gavrilovska, Ada

    2009-01-01

    Technological Advances and Problems of High Performance Communications. An ecosystem of solutions along a stack of technology layers. Cohesively collecting state-of-the-art contributions from leading researchers in industry, national laboratories, and academia, Attaining High Performance Communications: A Vertical Approach discusses various issues pertaining to high performance communications in a particular layer of a vertical stack. It explores efficient interconnection hardware, the architectural aspects of network adapters and their integration with processor cores, the design of scalable

  9. Spray-combustion synthesis: efficient solution route to high-performance oxide transistors.

    Science.gov (United States)

    Yu, Xinge; Smith, Jeremy; Zhou, Nanjia; Zeng, Li; Guo, Peijun; Xia, Yu; Alvarez, Ana; Aghion, Stefano; Lin, Hui; Yu, Junsheng; Chang, Robert P H; Bedzyk, Michael J; Ferragut, Rafael; Marks, Tobin J; Facchetti, Antonio

    2015-03-17

    Metal-oxide (MO) semiconductors have emerged as enabling materials for next generation thin-film electronics owing to their high carrier mobilities, even in the amorphous state, large-area uniformity, low cost, and optical transparency, which are applicable to flat-panel displays, flexible circuitry, and photovoltaic cells. Impressive progress in solution-processed MO electronics has been achieved using methodologies such as sol gel, deep-UV irradiation, preformed nanostructures, and combustion synthesis. Nevertheless, because of incomplete lattice condensation and film densification, high-quality solution-processed MO films having technologically relevant thicknesses achievable in a single step have yet to be shown. Here, we report a low-temperature, thickness-controlled coating process to create high-performance, solution-processed MO electronics: spray-combustion synthesis (SCS). We also report for the first time, to our knowledge, indium-gallium-zinc-oxide (IGZO) transistors having densification, nanoporosity, electron mobility, trap densities, bias stability, and film transport approaching those of sputtered films and compatible with conventional fabrication (FAB) operations. PMID:25733848

  10. High Performance Spaceflight Computing (HPSC) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In 2012, the NASA Game Changing Development Program (GCDP), residing in the NASA Space Technology Mission Directorate (STMD), commissioned a High Performance...

  11. High performance carbon nanocomposites for ultracapacitors

    Science.gov (United States)

    Lu, Wen

    2012-10-02

    The present invention relates to composite electrodes for electrochemical devices, particularly to carbon nanotube composite electrodes for high performance electrochemical devices, such as ultracapacitors.

  12. A novel p-type and metallic dual-functional Cu-Al2O3 ultra-thin layer as the back electrode enabling high performance of thin film solar cells.

    Science.gov (United States)

    Lin, Qinxian; Su, Yantao; Zhang, Ming-Jian; Yang, Xiaoyang; Yuan, Sheng; Hu, Jiangtao; Lin, Yuan; Liang, Jun; Pan, Feng

    2016-09-14

    Increasing the open-circuit voltage (Voc) along with the fill factor (FF) is pivotal for the performance improvement of solar cells. In this work, we report the design and construction of a new structure of CdS/CdTe/Al2O3/Cu using the atomic layer deposition (ALD) method, and then we control Cu diffusion through the Al2O3 atomic layer into the CdTe layer. Surprisingly, this generates a novel p-type and metallic dual-functional Cu-Al2O3 atomic layer. Due to this dual-functional character of the Cu-Al2O3 layer, an efficiency improvement of 2% in comparison with the standard cell was observed. This novel dual-functional back contact structure could also be introduced into other thin film solar cells for their efficiency improvement. PMID:27384986

  13. China's High Performance Computer Standard Commission Established

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ China's High Performance Computer Standard Commission was established on March 28, 2007, under the guidance of the Science and Technology Bureau of the Ministry of Information Industry. It will prepare relevant professional standards on high performance computers to break through the monopoly in the field by foreign manufacturers and vendors.

  14. Scheduling in high performance buffered crossbar switches

    NARCIS (Netherlands)

    Mhamdi, L.

    2007-01-01

    High performance routers are the basic building blocks of the Internet. Most high performance routers built today use crossbars and a centralized scheduler. Due to their high scheduling complexity, crossbar-based routers are not scalable and cannot keep pace with the explosive growth of the Internet

  15. High Performance Work Systems and Firm Performance.

    Science.gov (United States)

    Kling, Jeffrey

    1995-01-01

    A review of 17 studies of high-performance work systems concludes that benefits of employee involvement, skill training, and other high-performance work practices tend to be greater when new methods are adopted as part of a consistent whole. (Author)

  16. Powder metallurgical high performance materials. Proceedings. Volume 4: late papers

    International Nuclear Information System (INIS)

    This is the fourth volume (late papers) of the 15th International Plansee seminar 2001 which general theme was 'Powder metallurgical high performance materials'. The seminar looked beyond the refractory metals and cemented carbides, which remain as its focus, to novel classes of materials, such as intermetallic compounds, with potential for high temperature applications. This volume 4 contains papers dealing with high performance P/M metals (ITER and fusion reactors, solid targets, materials microstructure, novel alloys, etc.), P/M hard materials ( production and characterization, tungsten carbides, titanium carbides, microstructural design, coatings composition and performance, etc.) and general topics. From 37 papers 24 correspond to INIS subject scope and they were indexed separately. (nevyjel)

  17. Laser additive manufacturing of high-performance materials

    CERN Document Server

    Gu, Dongdong

    2015-01-01

    This book entitled “Laser Additive Manufacturing of High-Performance Materials” covers the specific aspects of laser additive manufacturing of high-performance new materials components based on an unconventional materials incremental manufacturing philosophy, in terms of materials design and preparation, process control and optimization, and theories of physical and chemical metallurgy. This book describes the capabilities and characteristics of the development of new metallic materials components by laser additive manufacturing process, including nanostructured materials, in situ composite materials, particle reinforced metal matrix composites, etc. The topics presented in this book, similar as laser additive manufacturing technology itself, show a significant interdisciplinary feature, integrating laser technology, materials science, metallurgical engineering, and mechanical engineering. This is a book for researchers, students, practicing engineers, and manufacturing industry professionals interested i...

  18. Cu2ZnSnS4 Nanoparticle Sensitized Metal-Organic Framework Derived Mesoporous TiO2 as Photoanodes for High-Performance Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Tang, Rui; Xie, Zhirun; Zhou, Shujie; Zhang, Yanan; Yuan, Zhimin; Zhang, Luyuan; Yin, Longwei

    2016-08-31

    We present a facile hot injection and hydrothermal method to synthesize Cu2ZnSnS4 (CZTS) nanoparticles sensitized metal-organic frameworks (MOFs)-derived mesoporous TiO2. The MOFs-derived TiO2 inherits the large specific surface area and abundantly porous structures of the MOFs structure, which is of great benefit to effectively enhance the dye loading capacity, prolong the incident light traveling length by enhancing the multiple interparticle light-scattering process, and therefore improve the light absorption capacity. The sensitization of CZTS nanoparticles effectively enlarges the photoresponse range of TiO2 to the visible light region and facilitates photoinduced carrier transport. The formed heterostructure between CZTS nanoparticles and MOFs-derived TiO2 with matched band gap structure effectively suppresses the recombination rates of photogenerated electron/hole pairs and prolongs the lifespan of the carriers. Photoanodes based upon CZTS/MOFs-derived TiO2 photoanodes can achieve the maximal photocurrent of 17.27 mA cm(-2) and photoelectric conversion performance of 8.10%, nearly 1.93 and 2.21 times higher than those of TiO2-based photoanode. The related mechanism and model are investigated. The strikingly improved photoelectric properties are ascribed to a synergistic action between the MOFs-derived TiO2 and the sensitization of CZTS nanoparticles. PMID:27494761

  19. Dequenching of Cu(I)-bathocuproine disulfonate complexes for high-performance liquid chromatographic determination of phytochelatins, heavy-metal-binding peptides produced by the primitive red alga Cyanidioschyzon merolae.

    Science.gov (United States)

    Shirabe, Tomoo; Ito, Kyoko; Yoshimura, Etsuro

    2008-12-01

    A novel method has been devised for the determination of phytochelatins (PCs), heavy-metal-tolerant peptides produced by higher plants and algae. The method is based on the facts that fluorescence of bathocuproine disulfonate (BCS) is quenched by Cu(I) ions as a result of Cu(I)-BCS complex formation and that PCs compete with BCS for Cu(I). Detection of PCs via recovered fluorescence of BCS using the Cu(I)-BCS complex as a postcolumn reagent, following separation of peptides on an octyldecylsilane column, demonstrated a highly sensitive method for determination of PCs. PCs in the primitive red alga, Cyanidioschyzon merolae, grown in the presence or absence of added Cd(II) were successfully determined by this protocol. Unlike other methods for the determination of PCs, which rely on the SH groups in the peptides, the proposed method is unique in that detection is based on the chemical nature of PCs, which favors the formation of complexes with Cu(I). In this context, the new method yields chromatograms based on the strength of binding Cu(I) ions.

  20. Metal-Organic Frameworks Derived Porous Core/Shell Structured ZnO/ZnCo2O4/C Hybrids as Anodes for High-Performance Lithium-Ion Battery.

    Science.gov (United States)

    Ge, Xiaoli; Li, Zhaoqiang; Wang, Chengxiang; Yin, Longwei

    2015-12-01

    Metal-organic frameworks (MOFs) derived porous core/shell ZnO/ZnCo2O4/C hybrids with ZnO as a core and ZnCo2O4 as a shell are for the first time fabricated by using core/shell ZnCo-MOF precursors as reactant templates. The unique MOFs-derived core/shell structured ZnO/ZnCo2O4/C hybrids are assembled from nanoparticles of ZnO and ZnCo2O4, with homogeneous carbon layers coated on the surface of the ZnCo2O4 shell. When acting as anode materials for lithium-ion batteries (LIBs), the MOFs-derived porous ZnO/ZnCo2O4/C anodes exhibit outstanding cycling stability, high Coulombic efficiency, and remarkable rate capability. The excellent electrochemical performance of the ZnO/ZnCo2O4/C LIB anodes can be attributed to the synergistic effect of the porous structure of the MOFs-derived core/shell ZnO/ZnCo2O4/C and homogeneous carbon layer coating on the surface of the ZnCo2O4 shells. The hierarchically porous core/shell structure offers abundant active sites, enhances the electrode/electrolyte contact area, provides abundant channels for electrolyte penetration, and also alleviates the structure decomposition induced by Li(+) insertion/extraction. The carbon layers effectively improve the conductivity of the hybrids and thus enhance the electron transfer rate, efficiently prevent ZnCo2O4 from aggregation and disintegration, and partially buffer the stress induced by the volume change during cycles. This strategy may shed light on designing new MOF-based hybrid electrodes for energy storage and conversion devices.

  1. High Performance Computing Programming and Applications

    CERN Document Server

    Levesque, John

    2010-01-01

    High Performance Computing: Programming and Applications presents techniques that address new performance issues in the programming of high performance computing (HPC) applications. Omitting tedious details, the book discusses hardware architecture concepts and programming techniques that are the most pertinent to application developers for achieving high performance. Even though the text concentrates on C and Fortran, the techniques described can be applied to other languages, such as C++ and Java. Drawing on their experience with chips from AMD and systems, interconnects, and software from C

  2. High Performance Grinding and Advanced Cutting Tools

    CERN Document Server

    Jackson, Mark J

    2013-01-01

    High Performance Grinding and Advanced Cutting Tools discusses the fundamentals and advances in high performance grinding processes, and provides a complete overview of newly-developing areas in the field. Topics covered are grinding tool formulation and structure, grinding wheel design and conditioning and applications using high performance grinding wheels. Also included are heat treatment strategies for grinding tools, using grinding tools for high speed applications, laser-based and diamond dressing techniques, high-efficiency deep grinding, VIPER grinding, and new grinding wheels.

  3. Strategy Guideline: High Performance Residential Lighting

    Energy Technology Data Exchange (ETDEWEB)

    Holton, J.

    2012-02-01

    The Strategy Guideline: High Performance Residential Lighting has been developed to provide a tool for the understanding and application of high performance lighting in the home. The high performance lighting strategies featured in this guide are drawn from recent advances in commercial lighting for application to typical spaces found in residential buildings. This guide offers strategies to greatly reduce lighting energy use through the application of high quality fluorescent and light emitting diode (LED) technologies. It is important to note that these strategies not only save energy in the home but also serve to satisfy the homeowner's expectations for high quality lighting.

  4. High performance heat pump absorption cycles

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarin, R.; Longo, G.; Rossetto, L.

    1988-10-01

    Absorption heat pumps can provide high performances when operating in suitable cycles with multiple effects. This report describes some multistage cycles and evaluates the coefficient of performance realistically obtainable both in winter and summer working conditions.

  5. Radiation Hard High Performance Optoelectronic Devices Project

    Data.gov (United States)

    National Aeronautics and Space Administration — High-performance, radiation-hard, widely-tunable integrated laser/modulator chip and large-area avalanche photodetectors (APDs) are key components of optical...

  6. Analog circuit design designing high performance amplifiers

    CERN Document Server

    Feucht, Dennis

    2010-01-01

    The third volume Designing High Performance Amplifiers applies the concepts from the first two volumes. It is an advanced treatment of amplifier design/analysis emphasizing both wideband and precision amplification.

  7. High-performance computing using FPGAs

    CERN Document Server

    Benkrid, Khaled

    2013-01-01

    This book is concerned with the emerging field of High Performance Reconfigurable Computing (HPRC), which aims to harness the high performance and relative low power of reconfigurable hardware–in the form Field Programmable Gate Arrays (FPGAs)–in High Performance Computing (HPC) applications. It presents the latest developments in this field from applications, architecture, and tools and methodologies points of view. We hope that this work will form a reference for existing researchers in the field, and entice new researchers and developers to join the HPRC community.  The book includes:  Thirteen application chapters which present the most important application areas tackled by high performance reconfigurable computers, namely: financial computing, bioinformatics and computational biology, data search and processing, stencil computation e.g. computational fluid dynamics and seismic modeling, cryptanalysis, astronomical N-body simulation, and circuit simulation.     Seven architecture chapters which...

  8. High Performance Methane Thrust Chamber (HPMTC) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ORBITEC proposes to develop a High-Performance Methane Thrust Chamber (HPMRE) to meet the demands of advanced chemical propulsion systems for deep-space mission...

  9. High performance computing in Windows Azure cloud

    OpenAIRE

    Ambruš, Dejan

    2013-01-01

    High performance, security, availability, scalability, flexibility and lower costs of maintenance have essentially contributed to the growing popularity of cloud computing in all spheres of life, especially in business. In fact cloud computing offers even more than this. With usage of virtual computing clusters a runtime environment for high performance computing can be efficiently implemented also in a cloud. There are many advantages but also some disadvantages of cloud computing, some ...

  10. HIGH PERFORMANCE COMPUTING APPLIED TO CLOUD COMPUTING

    OpenAIRE

    Li, Luxingzi

    2015-01-01

    The purpose of this thesis was to introduce high performance computing and cloud computing. The purpose was also to describe how to apply high performance computing to cloud computing as well as its possibilities and challenges. There were two case studies in the thesis project to present the application of cloud computing. Both quantitative and qualitative methods were used in this research. The majority of materials were from books and Internet resources. The thesis may be us...

  11. A High Performance SOFM Hardware-System

    OpenAIRE

    Rüping, Stefan; Porrmann, Mario; Rückert, Ulrich

    1997-01-01

    Many applications of Selforganizing Feature Maps (SOFMs) need a high performance hardware system in order to be efficient. Because of the regular and modular structure of SOFMs, a hardware realization is obvious. Based on the idea of a massively parallel system, several chips have been designed, manufactured and tested by the authors. In this paper a high performance system with the latest NBISOM_25 chips is presented. The NBISOM_25 integrated circuit contains 25 processing elements in a 5 by...

  12. Corrosion resistant amorphous alloys

    International Nuclear Information System (INIS)

    A review of publication data on corrosion resistance of amorphous alloys and the methods of amorphization of surface layers of massive materials (laser treatment, iron implantation, detonation-gas spraying, cathode and ion sputtering, electrodeposition) was made. A study was made on corrosion properties of Fe66Cr11B10Si4 alloy in cast state and after laser irradiation, rendering the surface amorphous as well as the samples of Arenco iron and steel 20 with ion-plasma coatings of Fe-Cr-Ni-Ti alloy. It was established that amorphous coatings posses much higher corrosion resistance as compared to crystalline alloys on the same base

  13. Influence of particle size and preparation methods on the physical and chemical stability of amorphous simvastatin

    DEFF Research Database (Denmark)

    Zhang, Fang; Aaltonen, Jaakko; Tian, Fang;

    2009-01-01

    This study investigated the factors influencing the stability of amorphous simvastatin. Quench-cooled amorphous simvastatin in two particle size ranges, 150-180 microm (QC-big) and ... stability were investigated. Physical stability (crystallization) of amorphous simvastatin stored at two conditions was monitored by X-ray powder diffractometry (XRPD) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Assessment of enthalpy relaxation of amorphous forms was conducted...... using DSC in order to link the physical and chemical stability with molecular mobility. Chemical stability was studied with high-performance liquid chromatography (HPLC). Results obtained from the current study revealed that the solubility of amorphous forms prepared by both methods was enhanced...

  14. Sputtering Deposition of Sandwich-Structured V2O5/Metal (V, W)/V2O5 Multilayers for the Preparation of High-Performance Thermally Sensitive VO2 Thin Films with Selectivity of VO2 (B) and VO2 (M) Polymorph.

    Science.gov (United States)

    Liu, Hengwu; Wan, Dongyun; Ishaq, Ahmad; Chen, Lanli; Guo, Beibei; Shi, Siqi; Luo, Hongjie; Gao, Yanfeng

    2016-03-01

    For specific application to an uncooled infrared detector, VO2 thin films should have a series of characteristics including purposefully chosen polymorphs, accurate stoichiometry, phase stabilization, a high temperature-coefficient of resistance (TCR), and suitable square-resistance. This work reports controllable preparation of high-performance VO2 films via post annealing of a sandwich-structured V2O5/metal (V, W)/V2O5 multilayer precursor, which was deposited by RF magnetron sputtering. This sandwich structure can dynamically regulate oxygen contents and doping element levels in the films, enabling us to achieve accurate regulation of stoichiometry and polymorphs. The precursor films undergo a B to M phase transition depending on the quantity of the metal layers. At the thickness of the metal layer below a limitation, the resulting film after heat treatment was VO2 (B), and above the limitation, the product was VO2 (M). The optical modulation of the VO2 (M) in the near-infrared region can be tuned from 1.2 to 39.8% (ΔT2000 nm). TCR values can range from -1.89 to -4.29%/K and the square-resistances at room temperature (R0) from 69.68 to 12.63 kΩ. The simplicity in phase regulation of the present method and the superior optical and electrical properties of the films may allow its wide applications in thermo-opto-electro sensing devices.

  15. Atomic simulation of mechanical behavior of Mg in a super-lattice of nanocrystalline Mg and amorphous Mg-Al alloy

    Energy Technology Data Exchange (ETDEWEB)

    Song, H. Y., E-mail: gsfshy@sohu.com [School of Aeronautics, Northwestern Polytechnical University, Xi' an 710072 (China); College of Material Science and Engineering, Xi' an Shiyou University, Xi' an 710065 (China); An, M. R.; Li, Y. L., E-mail: liyulong@nwpu.edu.cn; Deng, Q. [School of Aeronautics, Northwestern Polytechnical University, Xi' an 710072 (China)

    2014-12-07

    The mechanical properties of a super-lattice architecture composed of nanocrystalline Mg and Mg-Al amorphous alloy are investigated using molecular dynamics simulation. The results indicate that deformation mechanism of nanocrystalline Mg is obviously affected by the amorphous boundary spacing and temperature. The strength of the material increases with the decrease of amorphous boundary spacing, presenting a Hall-Petch effect at both 10 K and 300 K. A stress platform and following stiffness softening, as well as a linear strengthening in the plastic stage, are observed when the amorphous boundary spacing below 8.792 nm at 10 K. The implying reason may be that the amorphous boundary acts as the dislocations emission and absorption source. However, the second stress peak is not observed for the models at 300 K. Instead, the flow stress in plastic stage is a nearly constant value. The simulation demonstrates the emergence of the new grain, accompanied by the deformation twins and stacking faults associated with the plastic behaviors at 300 K. The general conclusions derived from this work may provide a guideline for the design of high-performance hexagonal close-packed metals.

  16. Amorphous iron (II) carbonate

    DEFF Research Database (Denmark)

    Sel, Ozlem; Radha, A.V.; Dideriksen, Knud;

    2012-01-01

    Abstract The synthesis, characterization and crystallization energetics of amorphous iron (II) carbonate (AFC) are reported. AFC may form as a precursor for siderite (FeCO3). The enthalpy of crystallization (DHcrys) of AFC is similar to that of amorphous magnesium carbonate (AMC) and more...

  17. Strategy Guideline. Partnering for High Performance Homes

    Energy Technology Data Exchange (ETDEWEB)

    Prahl, Duncan [IBACOS, Inc., Pittsburgh, PA (United States)

    2013-01-01

    High performance houses require a high degree of coordination and have significant interdependencies between various systems in order to perform properly, meet customer expectations, and minimize risks for the builder. Responsibility for the key performance attributes is shared across the project team and can be well coordinated through advanced partnering strategies. For high performance homes, traditional partnerships need to be matured to the next level and be expanded to all members of the project team including trades, suppliers, manufacturers, HERS raters, designers, architects, and building officials as appropriate. This guide is intended for use by all parties associated in the design and construction of high performance homes. It serves as a starting point and features initial tools and resources for teams to collaborate to continually improve the energy efficiency and durability of new houses.

  18. High performance bio-integrated devices

    Science.gov (United States)

    Kim, Dae-Hyeong; Lee, Jongha; Park, Minjoon

    2014-06-01

    In recent years, personalized electronics for medical applications, particularly, have attracted much attention with the rise of smartphones because the coupling of such devices and smartphones enables the continuous health-monitoring in patients' daily life. Especially, it is expected that the high performance biomedical electronics integrated with the human body can open new opportunities in the ubiquitous healthcare. However, the mechanical and geometrical constraints inherent in all standard forms of high performance rigid wafer-based electronics raise unique integration challenges with biotic entities. Here, we describe materials and design constructs for high performance skin-mountable bio-integrated electronic devices, which incorporate arrays of single crystalline inorganic nanomembranes. The resulting electronic devices include flexible and stretchable electrophysiology electrodes and sensors coupled with active electronic components. These advances in bio-integrated systems create new directions in the personalized health monitoring and/or human-machine interfaces.

  19. High performance parallel I/O

    CERN Document Server

    Prabhat

    2014-01-01

    Gain Critical Insight into the Parallel I/O EcosystemParallel I/O is an integral component of modern high performance computing (HPC), especially in storing and processing very large datasets to facilitate scientific discovery. Revealing the state of the art in this field, High Performance Parallel I/O draws on insights from leading practitioners, researchers, software architects, developers, and scientists who shed light on the parallel I/O ecosystem.The first part of the book explains how large-scale HPC facilities scope, configure, and operate systems, with an emphasis on choices of I/O har

  20. Toward High Performance in Industrial Refrigeration Systems

    DEFF Research Database (Denmark)

    Thybo, C.; Izadi-Zamanabadi, Roozbeh; Niemann, H.

    2002-01-01

    Achieving high performance in complex industrial systems requires information manipulation at different system levels. The paper shows how different models of same subsystems, but using different quality of information/data, are used for fault diagnosis as well as robust control design in industr......Achieving high performance in complex industrial systems requires information manipulation at different system levels. The paper shows how different models of same subsystems, but using different quality of information/data, are used for fault diagnosis as well as robust control design...... in industrial refrigeration systems....

  1. Towards High Performance in Industrial Refrigeration Systems

    DEFF Research Database (Denmark)

    Thybo, C.; Izadi-Zamanabadi, Roozbeh; Niemann, H.

    2002-01-01

    Achieving high performance in complex industrial systems requires information manipulation at different system levels. The paper shows how different models of same subsystems, but using different quality of information/data, are used for fault diagnosis as well as robust control design in industr......Achieving high performance in complex industrial systems requires information manipulation at different system levels. The paper shows how different models of same subsystems, but using different quality of information/data, are used for fault diagnosis as well as robust control design...... in industrial refrigeration systems....

  2. Magnetic Properties of Nanometer-sized Crystalline and Amorphous Particles

    DEFF Research Database (Denmark)

    Mørup, Steen; Bødker, Franz; Hansen, Mikkel Fougt;

    1997-01-01

    Amorphous transition metal-metalloid alloy particles can be prepared by chemical preparation techniques. We discuss the preparation of transition metal-boron and iron-carbon particles and their magnetic properties. Nanometer-sized particles of both crystalline and amorphous magnetic materials...... are superparamagnetic at finite temperatures. The temperature dependence of the superparamagnetic relaxation time and the influence of inter-particle interactions is discussed. Finally, some examples of studies of surface magnetization of alpha-Fe particles are presented....

  3. Thermal interface pastes nanostructured for high performance

    Science.gov (United States)

    Lin, Chuangang

    thermal paste that is particularly effective for smooth surfaces was obtained by using nanoclay platelets (obtained by organic modification and subsequent chemical exfoliation) as the solid component. The superiority of the nanoclay paste for smooth surfaces is attributed to the submicrometer bond line thickness. Electrically nonconductive high-performance thermal paste was obtained by using either fumed alumina or fumed zinc oxide. The nonconductivity serves to avoid short circuiting in the electronic application environment. The fumed oxides are as effective as carbon black, but are advantageous in their electrical nonconductivity. Without fuming, the oxides are less effective. The silane coating on fumed metal oxides helps. Electrically nonconductive thermal pastes have also been attained using carbon as the thermally conductive solid component. Either fumed alumina or nanoclay is used to break the electrical connectivity of the carbon in the paste to obtain electrical nonconductivity. Among the nanostrucutred pastes developed in this dissertation research, the nanoclay (0.6 vol.%) paste is recommended for smooth surfaces. With the overall performance for smooth and rough surfaces considered, the carbon black (Tokai, 15 vol.%) paste is recommended. Carbon black (Tokai) is more effective than carbon black (Cabot), due to its small aggregate size. All the pastes developed are much more effective than carbon nanotube arrays investigated by others. The rheological behavior of the thermal pastes was studied under strain sweep, frequency sweep, steady state flow and temperature ramping. In the absence of a solid component, the vehicle is Newtonian and fluid-like. In the presence of a solid component, the paste is a Bingham plastic that exhibits shear thinning and mainly solid-like behavior. The addition of antioxidants enhances the solid-like character, increases the yield stress, the plastic viscosity and the bond line thickness, and decreases the thermal contact

  4. High performance flexible electronics for biomedical devices.

    Science.gov (United States)

    Salvatore, Giovanni A; Munzenrieder, Niko; Zysset, Christoph; Kinkeldei, Thomas; Petti, Luisa; Troster, Gerhard

    2014-01-01

    Plastic electronics is soft, deformable and lightweight and it is suitable for the realization of devices which can form an intimate interface with the body, be implanted or integrated into textile for wearable and biomedical applications. Here, we present flexible electronics based on amorphous oxide semiconductors (a-IGZO) whose performance can achieve MHz frequency even when bent around hair. We developed an assembly technique to integrate complex electronic functionalities into textile while preserving the softness of the garment. All this and further developments can open up new opportunities in health monitoring, biotechnology and telemedicine.

  5. Commercial Buildings High Performance Rooftop Unit Challenge

    Energy Technology Data Exchange (ETDEWEB)

    None

    2011-12-16

    The U.S. Department of Energy (DOE) and the Commercial Building Energy Alliances (CBEAs) are releasing a new design specification for high performance rooftop air conditioning units (RTUs). Manufacturers who develop RTUs based on this new specification will find strong interest from the commercial sector due to the energy and financial savings.

  6. High performance computing on vector systems

    CERN Document Server

    Roller, Sabine

    2008-01-01

    Presents the developments in high-performance computing and simulation on modern supercomputer architectures. This book covers trends in hardware and software development in general and specifically the vector-based systems and heterogeneous architectures. It presents innovative fields like coupled multi-physics or multi-scale simulations.

  7. Using LEADS to shift to high performance.

    Science.gov (United States)

    Fenwick, Shauna; Hagge, Erna

    2016-03-01

    Health systems across Canada are tasked to measure results of all their strategic initiatives. Included in most strategic plans is leadership development. How to measure leadership effectiveness in relation to organizational objectives is key in determining organizational effectiveness. The following findings offer considerations for a 21(st)-century approach to shifting to high-performance systems. PMID:26872796

  8. A High-performance Small Signal Amplifier

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    According to questions in the design of high quality small signal amplifier, this paper gave a new-type high performance small signal amplifier. The paper selected the operational amplifier of ICL Company and designed a new-type circuit with simple, low cost and excellent performance.

  9. High Performance Networks for High Impact Science

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Mary A.; Bair, Raymond A.

    2003-02-13

    This workshop was the first major activity in developing a strategic plan for high-performance networking in the Office of Science. Held August 13 through 15, 2002, it brought together a selection of end users, especially representing the emerging, high-visibility initiatives, and network visionaries to identify opportunities and begin defining the path forward.

  10. An Introduction to High Performance Fortran

    Directory of Open Access Journals (Sweden)

    John Merlin

    1995-01-01

    Full Text Available High Performance Fortran (HPF is an informal standard for extensions to Fortran 90 to assist its implementation on parallel architectures, particularly for data-parallel computation. Among other things, it includes directives for specifying data distribution across multiple memories, and concurrent execution features. This article provides a tutorial introduction to the main features of HPF.

  11. Toward High Performance in Industrial Refrigeration Systems

    OpenAIRE

    Thybo, C.; Izadi-Zamanabadi, Roozbeh; Niemann, H.

    2002-01-01

    Achieving high performance in complex industrial systems requires information manipulation at different system levels. The paper shows how different models of same subsystems, but using different quality of information/data, are used for fault diagnosis as well as robust control design in industrial refrigeration systems.

  12. Performance, Performance System, and High Performance System

    Science.gov (United States)

    Jang, Hwan Young

    2009-01-01

    This article proposes needed transitions in the field of human performance technology. The following three transitions are discussed: transitioning from training to performance, transitioning from performance to performance system, and transitioning from learning organization to high performance system. A proposed framework that comprises…

  13. Using LEADS to shift to high performance.

    Science.gov (United States)

    Fenwick, Shauna; Hagge, Erna

    2016-03-01

    Health systems across Canada are tasked to measure results of all their strategic initiatives. Included in most strategic plans is leadership development. How to measure leadership effectiveness in relation to organizational objectives is key in determining organizational effectiveness. The following findings offer considerations for a 21(st)-century approach to shifting to high-performance systems.

  14. Project materials [Commercial High Performance Buildings Project

    Energy Technology Data Exchange (ETDEWEB)

    None

    2001-01-01

    The Consortium for High Performance Buildings (ChiPB) is an outgrowth of DOE'S Commercial Whole Buildings Roadmapping initiatives. It is a team-driven public/private partnership that seeks to enable and demonstrate the benefit of buildings that are designed, built and operated to be energy efficient, environmentally sustainable, superior quality, and cost effective.

  15. High Performance Work Systems for Online Education

    Science.gov (United States)

    Contacos-Sawyer, Jonna; Revels, Mark; Ciampa, Mark

    2010-01-01

    The purpose of this paper is to identify the key elements of a High Performance Work System (HPWS) and explore the possibility of implementation in an online institution of higher learning. With the projected rapid growth of the demand for online education and its importance in post-secondary education, providing high quality curriculum, excellent…

  16. Trehalose amorphization and recrystallization.

    Science.gov (United States)

    Sussich, Fabiana; Cesàro, Attilio

    2008-10-13

    The stability of the amorphous trehalose prepared by using several procedures is presented and discussed. Amorphization is shown to occur by melting (T(m)=215 degrees C) or milling (room temperature) the crystalline anhydrous form TRE-beta. Fast dehydration of the di-hydrate crystalline polymorph, TRE-h, also produces an amorphous phase. Other dehydration procedures of TRE-h, such as microwave treatment, supercritical extraction or gentle heating at low scan rates, give variable fractions of the polymorph TRE-alpha, that undergo amorphization upon melting (at lower temperature, T(m)=130 degrees C). Additional procedures for amorphization, such as freeze-drying, spray-drying or evaporation of trehalose solutions, are discussed. All these procedures are classified depending on the capability of the undercooled liquid phase to undergo cold crystallization upon heating the glassy state at temperatures above the glass transition temperature (T(g)=120 degrees C). The recrystallizable amorphous phase is invariably obtained by the melt of the polymorph TRE-alpha, while other procedures always give an amorphous phase that is unable to crystallize above T(g). The existence of two different categories is analyzed in terms of the transformation paths and the hypothesis that the systems may exhibit different molecular mobilities.

  17. RESEARCH ON THE HIGH PERFORMANCE COMPOSITE ROAD CONCRETE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Ordinary concrete presents short service life when used for building and repairing high-grade road with heavy traffic due to its large brittleness, poor bending flexibility and serious shrinkage on drying. In this paper,a new kind of high performance concrete has been designed by means of combination of organic, inorganic material as well as metal material.The research and application have shown that this new concrete can significantly counteract the deficiency of ordinary concrete and give excellent mechanical properties and pavement performances. The application of this new kind of concrete is of great social and economic significance.

  18. Remarkable changes in interface O vacancy and metal-oxide bonds in amorphous indium-gallium-zinc-oxide thin-film transistors by long time annealing at 250 °C

    International Nuclear Information System (INIS)

    We have studied the effect of long time post-fabrication annealing on negative bias illumination stress (NBIS) of amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film-transistors. Annealing for 100 h at 250 °C increased the field effect mobility from 14.7 cm2/V s to 17.9 cm2/V s and reduced the NBIS instability remarkably. Using X-ray photoelectron spectroscopy, the oxygen vacancy and OH were found to exist at the interfaces of a-IGZO with top and bottom SiO2. Long time annealing helps to decrease the vacancy concentration and increase the metal-oxygen bonds at the interfaces; this leads to increase in the free carrier concentrations in a-IGZO and field-effect mobility. X-ray reflectivity measurement indicated the increment of a-IGZO film density of 5.63 g cm−3 to 5.83 g cm−3 (3.4% increase) by 100 h annealing at 250 °C. The increase in film density reveals the decrease of O vacancy concentration and reduction of weak metal-oxygen bonds in a-IGZO, which substantially helps to improve the NBIS stability

  19. STRUCTURAL INTERACTIONS OF HYDROGEN WITH BULK AMORPHOUS MICROSTRUCTURES IN METALLIC SYSTEMS UNDERSTANDING THE ROLE OF PARTIAL CRYSTALLINITY ON PERMEATION AND EMBRITTLEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Brinkman, Kyle; Fox, Elise; Korinko, Paul; Adams, Thad

    2010-05-10

    The development of metallic glasses in bulk form has led to a resurgence of interest into the utilization of these materials for a variety of applications. A potentially exciting application for these bulk metallic glass (BMG) materials is their use as composite membranes to replace high cost Pd/Pd-alloy membranes for enhanced gas separation processes. One of the major drawbacks to the industrial use of Pd/Pd-alloy membranes is that during cycling above and below a critical temperature an irreversible change takes place in the palladium lattice structure which can result in significant damage to the membrane. Furthermore, the cost associated with Pd-based membranes is a potential detractor for their continued use and BMG alloys offer a potentially attractive alternative. Several BMG alloys have been shown to possess high permeation rates, comparable to those measured for pure Pd metal. In addition, high strength and toughness when either in-situ or ex-situ second phase dispersoids are present. Both of these properties, high permeation and high strength/toughness, potentially make these materials attractive for gas separation membranes that could resist hydrogen 'embrittlement'. However, a fundamental understanding of the relationship between partially crystalline 'structure'/devitrification and permeation/embrittlement in these BMG materials is required in order to determine the operating window for separation membranes and provide additional input to the material synthesis community for improved alloy design. This project aims to fill the knowledge gap regarding the impact of crystallization on the permeation properties of metallic glass materials. The objectives of this study are to (i) determine the crystallization behavior in different gas environments of Fe and Zr based commercially available bulk metallic glass and (ii) quantify the effects of partial crystallinity on the hydrogen permeation properties of these metallic glass membranes.

  20. Amorphous Solid Water:

    DEFF Research Database (Denmark)

    Wenzel, Jack; Linderstrøm-Lang, C. U.; Rice, Stuart A.

    1975-01-01

    The structure factor of amorphous solid D2O deposited from the vapor at 10°K has been obtained by measuring the neutron diffraction spectrum in the wave vector transfer from 0.8 to 12.3 reciprocal angstroms. The results indicate that the phase investigated is amorphous and has a liquiid-like stru......The structure factor of amorphous solid D2O deposited from the vapor at 10°K has been obtained by measuring the neutron diffraction spectrum in the wave vector transfer from 0.8 to 12.3 reciprocal angstroms. The results indicate that the phase investigated is amorphous and has a liquiid...

  1. High-performance liquid chromatography of biopolymers

    Energy Technology Data Exchange (ETDEWEB)

    Regnier, F.E.

    1983-10-21

    The ability to separate biological macromolecules with good resolution on liquid chromatographic columns has depended on the development of suitable packing materials. In size exclusion chromatography, molecules are separated by size on the basis of differential permeation of the packing. Ion exchange, hydrophobic interaction (or reversed-phase), and affinity chromatography are all surface-mediated separation methods, although they depend on different retention mechanisms. High-performance liquid chromatographic columns designed for biopolymers offer major advantages over conventional columns in both speed and resolving power. The exponential growth of literature on the high-performance separation of peptides and proteins in particular indicates that the techniques will become the dominant form of column liquid chromatography. 92 refs., 4 figs.

  2. Evaluation of high-performance computing software

    Energy Technology Data Exchange (ETDEWEB)

    Browne, S.; Dongarra, J. [Univ. of Tennessee, Knoxville, TN (United States); Rowan, T. [Oak Ridge National Lab., TN (United States)

    1996-12-31

    The absence of unbiased and up to date comparative evaluations of high-performance computing software complicates a user`s search for the appropriate software package. The National HPCC Software Exchange (NHSE) is attacking this problem using an approach that includes independent evaluations of software, incorporation of author and user feedback into the evaluations, and Web access to the evaluations. We are applying this approach to the Parallel Tools Library (PTLIB), a new software repository for parallel systems software and tools, and HPC-Netlib, a high performance branch of the Netlib mathematical software repository. Updating the evaluations with feed-back and making it available via the Web helps ensure accuracy and timeliness, and using independent reviewers produces unbiased comparative evaluations difficult to find elsewhere.

  3. High performance cloud auditing and applications

    CERN Document Server

    Choi, Baek-Young; Song, Sejun

    2014-01-01

    This book mainly focuses on cloud security and high performance computing for cloud auditing. The book discusses emerging challenges and techniques developed for high performance semantic cloud auditing, and presents the state of the art in cloud auditing, computing and security techniques with focus on technical aspects and feasibility of auditing issues in federated cloud computing environments.   In summer 2011, the United States Air Force Research Laboratory (AFRL) CyberBAT Cloud Security and Auditing Team initiated the exploration of the cloud security challenges and future cloud auditing research directions that are covered in this book. This work was supported by the United States government funds from the Air Force Office of Scientific Research (AFOSR), the AFOSR Summer Faculty Fellowship Program (SFFP), the Air Force Research Laboratory (AFRL) Visiting Faculty Research Program (VFRP), the National Science Foundation (NSF) and the National Institute of Health (NIH). All chapters were partially suppor...

  4. Planning for high performance project teams

    International Nuclear Information System (INIS)

    Both industry-wide research and corporate benchmarking studies confirm the significant savings in cost and time that result from early planning of a project. Amoco's Team Planning Workshop combines long-term strategic project planning and short-term tactical planning with team building to provide the basis for high performing project teams, better project planning, and effective implementation of the Amoco Common Process for managing projects

  5. High performance work practices, innovation and performance

    DEFF Research Database (Denmark)

    Jørgensen, Frances; Newton, Cameron; Johnston, Kim;

    2013-01-01

    Research spanning nearly 20 years has provided considerable empirical evidence for relationships between High Performance Work Practices (HPWPs) and various measures of performance including increased productivity, improved customer service, and reduced turnover. What stands out from......, and Africa to examine these various questions relating to the HPWP-innovation-performance relationship. Each paper discusses a practice that has been identified in HPWP literature and potential variables that can facilitate or hinder the effects of these practices of innovation- and performance...

  6. Molecular Dynamic Simulation on High Performance Infrastrucutres

    OpenAIRE

    Bergant, Anže

    2016-01-01

    This thesis covers comparison between different computer platforms of high performance computing while performing molecular dynamics simulations, which falls under very complex problems and needs lots of processing power. Our goal was to critically evaluate different platforms while solving molecular dynamics, so we used 1 to 16 processor cores on a computer cluster and one and two graphics processing units (GPU) for simulations. The results will be used while planning on buying new computer ...

  7. High-performance transaction processing in sprint

    OpenAIRE

    Camargos, Lásaro; Pedone, Fernando; Wielochy, Marcin

    2011-01-01

    Sprint is a middleware infrastructure for high performance and high availability data management. It extends the functionality of a standalone in-memory database (IMDB) server to a cluster of commodity shared-nothing servers. Applications accessing an IMDB are typically limited by the memory capacity of the machine running the IMDB. Sprint partitions and replicates the database into segments and stores them in several data servers. Applications are then limited by the aggregated memory of...

  8. High Performance Interconnect Network for Tianhe System

    Institute of Scientific and Technical Information of China (English)

    廖湘科; 庞征斌; 王克非; 卢宇彤; 谢旻; 夏军; 董德尊; 所光

    2015-01-01

    In this paper, we present the Tianhe-2 interconnect network and message passing services. We describe the architecture of the router and network interface chips, and highlight a set of hardware and software features effectively supporting high performance communications, ranging over remote direct memory access, collective optimization, hardware-enable reliable end-to-end communication, user-level message passing services, etc. Measured hardware performance results are also presented.

  9. Mix design of high-performance concrete

    OpenAIRE

    Aminul Islam Laskar

    2011-01-01

    A mix design procedure for high-performance concrete mixes has been presented in this paper. Since rheological parameters and compressive strength are fundamental properties of concrete in two different stages of production, the correlation between rheological parameters and compressive strength has been used instead of using water-cement ratio versus compressive strength relationship. Water-cement ratio and aggregate volume to paste volume ratio has also been determined from rheological beha...

  10. vSphere high performance cookbook

    CERN Document Server

    Sarkar, Prasenjit

    2013-01-01

    vSphere High Performance Cookbook is written in a practical, helpful style with numerous recipes focusing on answering and providing solutions to common, and not-so common, performance issues and problems.The book is primarily written for technical professionals with system administration skills and some VMware experience who wish to learn about advanced optimization and the configuration features and functions for vSphere 5.1.

  11. Mesostructured HfxAlyO2 Thin Films as Reliable and Robust Gate Dielectrics with Tunable Dielectric Constants for High-Performance Graphene-Based Transistors.

    Science.gov (United States)

    Lee, Yunseong; Jeon, Woojin; Cho, Yeonchoo; Lee, Min-Hyun; Jeong, Seong-Jun; Park, Jongsun; Park, Seongjun

    2016-07-26

    We introduce a reliable and robust gate dielectric material with tunable dielectric constants based on a mesostructured HfxAlyO2 film. The ultrathin mesostructured HfxAlyO2 film is deposited on graphene via a physisorbed-precursor-assisted atomic layer deposition process and consists of an intermediate state with small crystallized parts in an amorphous matrix. Crystal phase engineering using Al dopant is employed to achieve HfO2 phase transitions, which produce the crystallized part of the mesostructured HfxAlyO2 film. The effects of various Al doping concentrations are examined, and an enhanced dielectric constant of ∼25 is obtained. Further, the leakage current is suppressed (∼10(-8) A/cm(2)) and the dielectric breakdown properties are enhanced (breakdown field: ∼7 MV/cm) by the partially remaining amorphous matrix. We believe that this contribution is theoretically and practically relevant because excellent gate dielectric performance is obtained. In addition, an array of top-gated metal-insulator-graphene field-effect transistors is fabricated on a 6 in. wafer, yielding a capacitance equivalent oxide thickness of less than 1 nm (0.78 nm). This low capacitance equivalent oxide thickness has important implications for the incorporation of graphene into high-performance silicon-based nanoelectronics. PMID:27355098

  12. Computational Biology and High Performance Computing 2000

    Energy Technology Data Exchange (ETDEWEB)

    Simon, Horst D.; Zorn, Manfred D.; Spengler, Sylvia J.; Shoichet, Brian K.; Stewart, Craig; Dubchak, Inna L.; Arkin, Adam P.

    2000-10-19

    The pace of extraordinary advances in molecular biology has accelerated in the past decade due in large part to discoveries coming from genome projects on human and model organisms. The advances in the genome project so far, happening well ahead of schedule and under budget, have exceeded any dreams by its protagonists, let alone formal expectations. Biologists expect the next phase of the genome project to be even more startling in terms of dramatic breakthroughs in our understanding of human biology, the biology of health and of disease. Only today can biologists begin to envision the necessary experimental, computational and theoretical steps necessary to exploit genome sequence information for its medical impact, its contribution to biotechnology and economic competitiveness, and its ultimate contribution to environmental quality. High performance computing has become one of the critical enabling technologies, which will help to translate this vision of future advances in biology into reality. Biologists are increasingly becoming aware of the potential of high performance computing. The goal of this tutorial is to introduce the exciting new developments in computational biology and genomics to the high performance computing community.

  13. Thermomagnetic analysis of amorphous (CoxFe1-x)73.5Nb3Cu1Si13.5B9 metallic glasses

    International Nuclear Information System (INIS)

    Metallic glass samples of (CoxFe1-x)73.5Nb3Cu1Si13.5B9 are studied by thermomagnetic analysis. The Curie temperature increases with the substitution of Fe by Co, and crystallization temperature decreases. A simple consideration of the alloy as the sum of two magnetic systems is applied with good results. The observed discrepancies are explained as due to a magnetic interaction between the Co and Fe atoms

  14. Toward a theory of high performance.

    Science.gov (United States)

    Kirby, Julia

    2005-01-01

    What does it mean to be a high-performance company? The process of measuring relative performance across industries and eras, declaring top performers, and finding the common drivers of their success is such a difficult one that it might seem a fool's errand to attempt. In fact, no one did for the first thousand or so years of business history. The question didn't even occur to many scholars until Tom Peters and Bob Waterman released In Search of Excellence in 1982. Twenty-three years later, we've witnessed several more attempts--and, just maybe, we're getting closer to answers. In this reported piece, HBR senior editor Julia Kirby explores why it's so difficult to study high performance and how various research efforts--including those from John Kotter and Jim Heskett; Jim Collins and Jerry Porras; Bill Joyce, Nitin Nohria, and Bruce Roberson; and several others outlined in a summary chart-have attacked the problem. The challenge starts with deciding which companies to study closely. Are the stars the ones with the highest market caps, the ones with the greatest sales growth, or simply the ones that remain standing at the end of the game? (And when's the end of the game?) Each major study differs in how it defines success, which companies it therefore declares to be worthy of emulation, and the patterns of activity and attitude it finds in common among them. Yet, Kirby concludes, as each study's method incrementally solves problems others have faced, we are progressing toward a consensus theory of high performance. PMID:16028814

  15. Dawning4000A high performance computer

    Institute of Scientific and Technical Information of China (English)

    SUN Ninghui; MENG Dan

    2007-01-01

    Dawning4000A is an AMD Opteron-based Linux Cluster with 11.2Tflops peak performance and 8.06Tflops Linpack performance.It was developed for the Shanghai Supercomputer Center (SSC)as one of the computing power stations of the China National Grid (CNGrid)project.The Massively Cluster Computer (MCC)architecture is proposed to put added-value on the industry standard system.Several grid-enabling components are developed to support the running environment of the CNGrid.It is an achievement for a high performance computer with the low-cost approach.

  16. High Performance Network Security Using NIDS Approach

    Directory of Open Access Journals (Sweden)

    Sutapa Sarkar

    2014-06-01

    Full Text Available Ever increasing demand of good quality communication relies heavily on Network Intrusion Detection System (NIDS. Intrusion detection for network security demands high performance. This paper gives a description of the available approaches for a network intrusion detection system in both software and hardware implementation. This paper gives a description of the structure of Snort rule set which is a very popular software signature and anomaly based Intrusion Detection and prevention system. This paper also discusses the merit of FPGA devices to be used in network intrusion detection system implementation and the approaches used in hardware implementation of NIDS.

  17. Playa: High-Performance Programmable Linear Algebra

    Directory of Open Access Journals (Sweden)

    Victoria E. Howle

    2012-01-01

    Full Text Available This paper introduces Playa, a high-level user interface layer for composing algorithms for complex multiphysics problems out of objects from other Trilinos packages. Among other features, Playa provides very high-performance overloaded operators implemented through an expression template mechanism. In this paper, we give an overview of the central Playa objects from a user's perspective, show application to a sequence of increasingly complex solver algorithms, provide timing results for Playa's overloaded operators and other functions, and briefly survey some of the implementation issues involved.

  18. Utilities for high performance dispersion model PHYSIC

    Energy Technology Data Exchange (ETDEWEB)

    Yamazawa, Hiromi (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment)

    1992-09-01

    The description and usage of the utilities for the dispersion calculation model PHYSIC were summarized. The model was developed in the study of developing high performance SPEEDI with the purpose of introducing meteorological forecast function into the environmental emergency response system. The procedure of PHYSIC calculation consists of three steps; preparation of relevant files, creation and submission of JCL, and graphic output of results. A user can carry out the above procedure with the help of the Geographical Data Processing Utility, the Model Control Utility, and the Graphic Output Utility. (author).

  19. Applications of modern high performance networks

    CERN Document Server

    Zubairi, Junaid Ahmed

    2009-01-01

    This Ebook presents state-of-the-art solutions in applications of modern high performance networks. The topics covered in this Ebook include mobile ad-hoc networks, clusters for distance computing, clustering technologies and deployment, emerging wireless sensor network technologies, ultra wideband wireless sensor networks, and smart agriculture with sensor networks. This Ebook stands out from others in the field by bringing together the most diverse applications of networks under one title. It is aimed at academicians, students and working professionals in hospitals, agriculture, government,

  20. Strategy Guideline. High Performance Residential Lighting

    Energy Technology Data Exchange (ETDEWEB)

    Holton, J. [IBACOS, Inc., Pittsburgh, PA (United States)

    2012-02-01

    This report has been developed to provide a tool for the understanding and application of high performance lighting in the home. The strategies featured in this guide are drawn from recent advances in commercial lighting for application to typical spaces found in residential buildings. This guide offers strategies to greatly reduce lighting energy use through the application of high quality fluorescent and light emitting diode (LED) technologies. It is important to note that these strategies not only save energy in the home but also serve to satisfy the homeowner’s expectations for high quality lighting.

  1. Study on the Retention Behaviour of Metal-Tetraphenyl Porphine Chelates in Reversed-Phase High Performance Liquid Chromatography%四苯基卟啉金属螯合物的反相高效液相色谱保留行为研究

    Institute of Scientific and Technical Information of China (English)

    石志红; 王燕桓; 傅承光

    2000-01-01

    The retention behaviour of metal chelates of α,β,γ,δ-tetraphenylporphi ne (TP P) was studied in reversed-phase high performance liquid chromatography (RP-HP L C). On C18 column, with various organic solvents as mobile phases, the ret ention of the chelates tends to increase in the following order: ZnTPP< TPP < NiTPP < C uTPP. This retention behaviour can get a good explanation from Horvath's "solvo p hobic theory". With the assumption that the electrostatic field strength of met a l chelates can be measured by the ratio of electronegativity vs. ionic radius (EN/ri ) of central metalion, E N/ri was established to be an index for the reten tion behaviour of metal-TPP chelates. It was found that lnk' is in good linear relationship with the EN/ri value.%研究了四苯基卟啉金属螯合物(TPP)的高效液相色谱保留行为.在C18柱上试验以各种有机溶剂洗脱金属螯合物,最终选择了甲醇-丙酮的非水体系作流动相.各螯合物的保留顺序为:ZnTPP<TPP<NiTPP<CuTPP.运用Horvath的疏溶剂理论解释了这种保留行为.文中采用电负性与离子半径之比(EN/ri)作为静电场强的量度,提出 EN/ri值作为四苯基卟啉金属螯合物保留值参数.实验发现,在不同的流动相配比条件下,lnk'与 EN/ri均呈良好的线性关系.

  2. Metal-induced crystallization fundamentals and applications

    CERN Document Server

    Wang, Zumin; Mittemeijer, Eric J

    2014-01-01

    Introduction to Metal-Induced CrystallizationAtomic Mechanisms and Interface Thermodynamics of Metal-Induced Crystallization of Amorphous Semiconductors at Low TemperaturesThermodynamics and Kinetics of Layer Exchange upon Low-Temperature Annealing Amorphous Si/Polycrystalline Al Layered StructuresMetal-Induced Crystallization by Homogeneous Insertion of Metallic Species in Amorphous SemiconductorsAluminum-Induced Crystallization: Applications in Photovoltaic TechnologiesApplications of Metal-Induced Crystallization for Advanced Flat-Panel DisplaysLaser-Assisted Meta

  3. High-performance computing for airborne applications

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, Heather M [Los Alamos National Laboratory; Manuzzato, Andrea [Los Alamos National Laboratory; Fairbanks, Tom [Los Alamos National Laboratory; Dallmann, Nicholas [Los Alamos National Laboratory; Desgeorges, Rose [Los Alamos National Laboratory

    2010-06-28

    Recently, there has been attempts to move common satellite tasks to unmanned aerial vehicles (UAVs). UAVs are significantly cheaper to buy than satellites and easier to deploy on an as-needed basis. The more benign radiation environment also allows for an aggressive adoption of state-of-the-art commercial computational devices, which increases the amount of data that can be collected. There are a number of commercial computing devices currently available that are well-suited to high-performance computing. These devices range from specialized computational devices, such as field-programmable gate arrays (FPGAs) and digital signal processors (DSPs), to traditional computing platforms, such as microprocessors. Even though the radiation environment is relatively benign, these devices could be susceptible to single-event effects. In this paper, we will present radiation data for high-performance computing devices in a accelerated neutron environment. These devices include a multi-core digital signal processor, two field-programmable gate arrays, and a microprocessor. From these results, we found that all of these devices are suitable for many airplane environments without reliability problems.

  4. Transport in JET high performance plasmas

    International Nuclear Information System (INIS)

    Two type of high performance scenarios have been produced in JET during DTE1 campaign. One of them is the well known and extensively used in the past ELM-free hot ion H-mode scenario which has two distinct regions- plasma core and the edge transport barrier. The results obtained during DTE-1 campaign with D, DT and pure T plasmas confirms our previous conclusion that the core transport scales as a gyroBohm in the inner half of plasma volume, recovers its Bohm nature closer to the separatrix and behaves as ion neoclassical in the transport barrier. Measurements on the top of the barrier suggest that the width of the barrier is dependent upon isotope and moreover suggest that fast ions play a key role. The other high performance scenario is a relatively recently developed Optimised Shear Scenario with small or slightly negative magnetic shear in plasma core. Different mechanisms of Internal Transport Barrier (ITB) formation have been tested by predictive modelling and the results are compared with experimentally observed phenomena. The experimentally observed non-penetration of the heavy impurities through the strong ITB which contradicts to a prediction of the conventional neo-classical theory is discussed. (author)

  5. Strategy Guideline: Partnering for High Performance Homes

    Energy Technology Data Exchange (ETDEWEB)

    Prahl, D.

    2013-01-01

    High performance houses require a high degree of coordination and have significant interdependencies between various systems in order to perform properly, meet customer expectations, and minimize risks for the builder. Responsibility for the key performance attributes is shared across the project team and can be well coordinated through advanced partnering strategies. For high performance homes, traditional partnerships need to be matured to the next level and be expanded to all members of the project team including trades, suppliers, manufacturers, HERS raters, designers, architects, and building officials as appropriate. In an environment where the builder is the only source of communication between trades and consultants and where relationships are, in general, adversarial as opposed to cooperative, the chances of any one building system to fail are greater. Furthermore, it is much harder for the builder to identify and capitalize on synergistic opportunities. Partnering can help bridge the cross-functional aspects of the systems approach and achieve performance-based criteria. Critical success factors for partnering include support from top management, mutual trust, effective and open communication, effective coordination around common goals, team building, appropriate use of an outside facilitator, a partnering charter progress toward common goals, an effective problem-solving process, long-term commitment, continuous improvement, and a positive experience for all involved.

  6. Management issues for high performance storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Louis, S. [Lawrence Livermore National Lab., CA (United States); Burris, R. [Oak Ridge National Lab., TN (United States)

    1995-03-01

    Managing distributed high-performance storage systems is complex and, although sharing common ground with traditional network and systems management, presents unique storage-related issues. Integration technologies and frameworks exist to help manage distributed network and system environments. Industry-driven consortia provide open forums where vendors and users cooperate to leverage solutions. But these new approaches to open management fall short addressing the needs of scalable, distributed storage. We discuss the motivation and requirements for storage system management (SSM) capabilities and describe how SSM manages distributed servers and storage resource objects in the High Performance Storage System (HPSS), a new storage facility for data-intensive applications and large-scale computing. Modem storage systems, such as HPSS, require many SSM capabilities, including server and resource configuration control, performance monitoring, quality of service, flexible policies, file migration, file repacking, accounting, and quotas. We present results of initial HPSS SSM development including design decisions and implementation trade-offs. We conclude with plans for follow-on work and provide storage-related recommendations for vendors and standards groups seeking enterprise-wide management solutions.

  7. The path toward HEP High Performance Computing

    CERN Document Server

    Apostolakis, John; Carminati, Federico; Gheata, Andrei; Wenzel, Sandro

    2014-01-01

    High Energy Physics code has been known for making poor use of high performance computing architectures. Efforts in optimising HEP code on vector and RISC architectures have yield limited results and recent studies have shown that, on modern architectures, it achieves a performance between 10% and 50% of the peak one. Although several successful attempts have been made to port selected codes on GPUs, no major HEP code suite has a 'High Performance' implementation. With LHC undergoing a major upgrade and a number of challenging experiments on the drawing board, HEP cannot any longer neglect the less-than-optimal performance of its code and it has to try making the best usage of the hardware. This activity is one of the foci of the SFT group at CERN, which hosts, among others, the Root and Geant4 project. The activity of the experiments is shared and coordinated via a Concurrency Forum, where the experience in optimising HEP code is presented and discussed. Another activity is the Geant-V project, centred on th...

  8. A Linux Workstation for High Performance Graphics

    Science.gov (United States)

    Geist, Robert; Westall, James

    2000-01-01

    The primary goal of this effort was to provide a low-cost method of obtaining high-performance 3-D graphics using an industry standard library (OpenGL) on PC class computers. Previously, users interested in doing substantial visualization or graphical manipulation were constrained to using specialized, custom hardware most often found in computers from Silicon Graphics (SGI). We provided an alternative to expensive SGI hardware by taking advantage of third-party, 3-D graphics accelerators that have now become available at very affordable prices. To make use of this hardware our goal was to provide a free, redistributable, and fully-compatible OpenGL work-alike library so that existing bodies of code could simply be recompiled. for PC class machines running a free version of Unix. This should allow substantial cost savings while greatly expanding the population of people with access to a serious graphics development and viewing environment. This should offer a means for NASA to provide a spectrum of graphics performance to its scientists, supplying high-end specialized SGI hardware for high-performance visualization while fulfilling the requirements of medium and lower performance applications with generic, off-the-shelf components and still maintaining compatibility between the two.

  9. High-performance computing in seismology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    The scientific, technical, and economic importance of the issues discussed here presents a clear agenda for future research in computational seismology. In this way these problems will drive advances in high-performance computing in the field of seismology. There is a broad community that will benefit from this work, including the petroleum industry, research geophysicists, engineers concerned with seismic hazard mitigation, and governments charged with enforcing a comprehensive test ban treaty. These advances may also lead to new applications for seismological research. The recent application of high-resolution seismic imaging of the shallow subsurface for the environmental remediation industry is an example of this activity. This report makes the following recommendations: (1) focused efforts to develop validated documented software for seismological computations should be supported, with special emphasis on scalable algorithms for parallel processors; (2) the education of seismologists in high-performance computing technologies and methodologies should be improved; (3) collaborations between seismologists and computational scientists and engineers should be increased; (4) the infrastructure for archiving, disseminating, and processing large volumes of seismological data should be improved.

  10. Building Trust in High-Performing Teams

    Directory of Open Access Journals (Sweden)

    Aki Soudunsaari

    2012-06-01

    Full Text Available Facilitation of growth is more about good, trustworthy contacts than capital. Trust is a driving force for business creation, and to create a global business you need to build a team that is capable of meeting the challenge. Trust is a key factor in team building and a needed enabler for cooperation. In general, trust building is a slow process, but it can be accelerated with open interaction and good communication skills. The fast-growing and ever-changing nature of global business sets demands for cooperation and team building, especially for startup companies. Trust building needs personal knowledge and regular face-to-face interaction, but it also requires empathy, respect, and genuine listening. Trust increases communication, and rich and open communication is essential for the building of high-performing teams. Other building materials are a shared vision, clear roles and responsibilities, willingness for cooperation, and supporting and encouraging leadership. This study focuses on trust in high-performing teams. It asks whether it is possible to manage trust and which tools and operation models should be used to speed up the building of trust. In this article, preliminary results from the authors’ research are presented to highlight the importance of sharing critical information and having a high level of communication through constant interaction.

  11. Optimizations for High Performance Network Virtualization

    Institute of Scientific and Technical Information of China (English)

    Fan-Fu Zhou; Ru-Hui Ma; Jian Li; Li-Xia Chen; Wei-Dong Qiu; Hai-Bing Guan

    2016-01-01

    The increasing requirements of intensive interoperaterbility among the distributed nodes desiderate the high performance network connections, owing to the substantial growth of cloud computing and datacenters. Network I/O virtualization aggregates the network resource and separates it into manageable parts for particular servers or devices, which provides effective consolidation and elastic management with high agility, flexibility and scalability as well as reduced cost and cabling. However, both network I/O virtualization aggregation and the increasing network speed incur higher traffic density, which generates a heavy system stress for I/O data moving and I/O event processing. Consequently, many researchers have dedicated to enhancing the system performance and alleviating the system overhead for high performance networking virtualization. This paper first elaborates the mainstreaming I/O virtualization methodologies, including device emulation, split-driver model and hardware assisted model. Then, the paper discusses and compares their specific advantages in addition to performance bottlenecks in practical utilities. This paper mainly focuses on the comprehensive survey of state-of-the-art approaches for performance optimizations and improvements as well as the portability management for network I/O virtualization. The approaches include various novel data delivery schemes, overhead mitigations for interrupt processing and adequate resource allocations for dynamic network states. Finally, we highlight the diversity of I/O virtualization besides the performance improvements in network virtualization infrastructure.

  12. Spin-exchange interaction between transition metals and metalloids in soft-ferromagnetic metallic glasses

    Science.gov (United States)

    Das, Santanu; Choudhary, Kamal; Chernatynskiy, Aleksandr; Choi Yim, Haein; Bandyopadhyay, Asis K.; Mukherjee, Sundeep

    2016-06-01

    High-performance magnetic materials have immense industrial and scientific importance in wide-ranging electronic, electromechanical, and medical device technologies. Metallic glasses with a fully amorphous structure are particularly suited for advanced soft-magnetic applications. However, fundamental scientific understanding is lacking for the spin-exchange interaction between metal and metalloid atoms, which typically constitute a metallic glass. Using an integrated experimental and molecular dynamics approach, we demonstrate the mechanism of electron interaction between transition metals and metalloids. Spin-exchange interactions were investigated for a Fe-Co metallic glass system of composition [(Co1-x Fe x )0.75B0.2Si0.05]96Cr4. The saturation magnetization increased with higher Fe concentration, but the trend significantly deviated from simple rule of mixtures. Ab initio molecular dynamics simulation was used to identify the ferromagnetic/anti-ferromagnetic interaction between the transition metals and metalloids. The overlapping band-structure and density of states represent ‘Stoner type’ magnetization for the amorphous alloys in contrast to ‘Heisenberg type’ in crystalline iron. The enhancement of magnetization by increasing iron was attributed to the interaction between Fe 3d and B 2p bands, which was further validated by valence-band study.

  13. High performance nano-composite technology development

    International Nuclear Information System (INIS)

    The trend of new material development are being to carried out not only high performance but also environmental attraction. Especially nano composite material which enhances the functional properties of components, extending the component life resulting to reduced the wastes and environmental contamination, has a great effect on various industrial area. The application of nano composite, depends on the polymer matrix and filler materials, has various application from semiconductor to medical field. In spite of nano composite merits, nano composite study are confined to a few special materials as a lab, scale because a few technical difficulties are still on hold. Therefore, the purpose of this study establishes the systematical planning to carried out the next generation projects on order to compete with other countries and overcome the protective policy of advanced countries with grasping over sea's development trends and our present status. (author).

  14. How to create high-performing teams.

    Science.gov (United States)

    Lam, Samuel M

    2010-02-01

    This article is intended to discuss inspirational aspects on how to lead a high-performance team. Cogent topics discussed include how to hire staff through methods of "topgrading" with reference to Geoff Smart and "getting the right people on the bus" referencing Jim Collins' work. In addition, once the staff is hired, this article covers how to separate the "eagles from the ducks" and how to inspire one's staff by creating the right culture with suggestions for further reading by Don Miguel Ruiz (The four agreements) and John Maxwell (21 Irrefutable laws of leadership). In addition, Simon Sinek's concept of "Start with Why" is elaborated to help a leader know what the core element should be with any superior culture. PMID:20127598

  15. Development of a high performance peristaltic micropump

    Science.gov (United States)

    Pham, My; Goo, Nam Seo

    2008-03-01

    In this study, a high performance peristaltic micropump has been developed and investigated. The micropump has three cylinder chambers which are connected through micro-channels for high pumping pressure performance. A circular-shaped mini LIPCA has been designed and manufactured for actuating diaphragm. In this LIPCA, a 0.1mm thickness PZT ceramic is used as an active layer. As a result, the actuator has shown to produce large out of plane deflection and consumed low power. During the design process, a coupled field analysis was conducted to predict the actuating behavior of a diaphragm and pumping performance. MEMS technique was used to fabricate the peristaltic micropump. Pumping performance of the present micropump was investigated both numerically and experimentally. The present peristaltic micropump was shown to have higher performance than the same kind of micropump developed else where.

  16. High performance computing and numerical modelling

    CERN Document Server

    ,

    2014-01-01

    Numerical methods play an ever more important role in astrophysics. This is especially true in theoretical works, but of course, even in purely observational projects, data analysis without massive use of computational methods has become unthinkable. The key utility of computer simulations comes from their ability to solve complex systems of equations that are either intractable with analytic techniques or only amenable to highly approximative treatments. Simulations are best viewed as a powerful complement to analytic reasoning, and as the method of choice to model systems that feature enormous physical complexity such as star formation in evolving galaxies, the topic of this 43rd Saas Fee Advanced Course. The organizers asked me to lecture about high performance computing and numerical modelling in this winter school, and to specifically cover the basics of numerically treating gravity and hydrodynamics in the context of galaxy evolution. This is still a vast field, and I necessarily had to select a subset ...

  17. [High-performance society and doping].

    Science.gov (United States)

    Gallien, C L

    2002-09-01

    Doping is not limited to high-level athletes. Likewise it is not limited to the field of sports activities. The doping phenomenon observed in sports actually reveals an underlying question concerning the notion of sports itself, and more widely, the society's conception of sports. In a high-performance society, which is also a high-risk society, doping behavior is observed in a large number of persons who may or may not participate in sports activities. The motivation is the search for individual success or profit. The fight against doping must therefore focus on individual responsibility and prevention in order to preserve athlete's health and maintain the ethical and educational value of sports activities.

  18. Linear algebra on high-performance computers

    Energy Technology Data Exchange (ETDEWEB)

    Dongarra, J.J.; Sorensen, D.C.

    1986-01-01

    This paper surveys work recently done at Argonne National Laboratory in an attempt to discover ways to construct numerical software for high-performance computers. The numerical algorithms are taken from several areas of numerical linear algebra. We discuss certain architectural features of advanced-computer architectures that will affect the design of algorithms. The technique of restructuring algorithms in terms of certain modules is reviewed. This technique has proved successful in obtaining a high level of transportability without severe loss of performance on a wide variety of both vector and parallel computers. The module technique is demonstrably effective for dense linear algebra problems. However, in the case of sparse and structured problems it may be difficult to identify general modules that will be as effective. New algorithms have been devised for certain problems in this category. We present examples in three important areas: banded systems, sparse QR factorization, and symmetric eigenvalue problems. 32 refs., 10 figs., 6 tabs.

  19. High performance nano-composite technology development

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Whung Whoe; Rhee, C. K.; Kim, S. J.; Park, S. D. [KAERI, Taejon (Korea, Republic of); Kim, E. K.; Jung, S. Y.; Ryu, H. J. [KRICT, Taejon (Korea, Republic of); Hwang, S. S.; Kim, J. K.; Hong, S. M. [KIST, Taejon (Korea, Republic of); Chea, Y. B. [KIGAM, Taejon (Korea, Republic of); Choi, C. H.; Kim, S. D. [ATS, Taejon (Korea, Republic of); Cho, B. G.; Lee, S. H. [HGREC, Taejon (Korea, Republic of)

    1999-06-15

    The trend of new material development are being to carried out not only high performance but also environmental attraction. Especially nano composite material which enhances the functional properties of components, extending the component life resulting to reduced the wastes and environmental contamination, has a great effect on various industrial area. The application of nano composite, depends on the polymer matrix and filler materials, has various application from semiconductor to medical field. In spite of nano composite merits, nano composite study are confined to a few special materials as a lab, scale because a few technical difficulties are still on hold. Therefore, the purpose of this study establishes the systematical planning to carried out the next generation projects on order to compete with other countries and overcome the protective policy of advanced countries with grasping over sea's development trends and our present status. (author).

  20. High performance robotic traverse of desert terrain.

    Energy Technology Data Exchange (ETDEWEB)

    Whittaker, William (Carnegie Mellon University, Pittsburgh, PA)

    2004-09-01

    This report presents tentative innovations to enable unmanned vehicle guidance for a class of off-road traverse at sustained speeds greater than 30 miles per hour. Analyses and field trials suggest that even greater navigation speeds might be achieved. The performance calls for innovation in mapping, perception, planning and inertial-referenced stabilization of components, hosted aboard capable locomotion. The innovations are motivated by the challenge of autonomous ground vehicle traverse of 250 miles of desert terrain in less than 10 hours, averaging 30 miles per hour. GPS coverage is assumed to be available with localized blackouts. Terrain and vegetation are assumed to be akin to that of the Mojave Desert. This terrain is interlaced with networks of unimproved roads and trails, which are a key to achieving the high performance mapping, planning and navigation that is presented here.

  1. High performance computing applications in neurobiological research

    Science.gov (United States)

    Ross, Muriel D.; Cheng, Rei; Doshay, David G.; Linton, Samuel W.; Montgomery, Kevin; Parnas, Bruce R.

    1994-01-01

    The human nervous system is a massively parallel processor of information. The vast numbers of neurons, synapses and circuits is daunting to those seeking to understand the neural basis of consciousness and intellect. Pervading obstacles are lack of knowledge of the detailed, three-dimensional (3-D) organization of even a simple neural system and the paucity of large scale, biologically relevant computer simulations. We use high performance graphics workstations and supercomputers to study the 3-D organization of gravity sensors as a prototype architecture foreshadowing more complex systems. Scaled-down simulations run on a Silicon Graphics workstation and scale-up, three-dimensional versions run on the Cray Y-MP and CM5 supercomputers.

  2. Mix design of high-performance concrete

    Directory of Open Access Journals (Sweden)

    Aminul Islam Laskar

    2011-12-01

    Full Text Available A mix design procedure for high-performance concrete mixes has been presented in this paper. Since rheological parameters and compressive strength are fundamental properties of concrete in two different stages of production, the correlation between rheological parameters and compressive strength has been used instead of using water-cement ratio versus compressive strength relationship. Water-cement ratio and aggregate volume to paste volume ratio has also been determined from rheological behavior and used in the mix design. In the proposed method, the designer is able to estimate rheological parameters like yield stress and plastic viscosity at the design stage for a given target strength, in addition to ingredients of concrete.

  3. Parallel Algebraic Multigrid Methods - High Performance Preconditioners

    Energy Technology Data Exchange (ETDEWEB)

    Yang, U M

    2004-11-11

    The development of high performance, massively parallel computers and the increasing demands of computationally challenging applications have necessitated the development of scalable solvers and preconditioners. One of the most effective ways to achieve scalability is the use of multigrid or multilevel techniques. Algebraic multigrid (AMG) is a very efficient algorithm for solving large problems on unstructured grids. While much of it can be parallelized in a straightforward way, some components of the classical algorithm, particularly the coarsening process and some of the most efficient smoothers, are highly sequential, and require new parallel approaches. This chapter presents the basic principles of AMG and gives an overview of various parallel implementations of AMG, including descriptions of parallel coarsening schemes and smoothers, some numerical results as well as references to existing software packages.

  4. High Performance Database Management for Earth Sciences

    Science.gov (United States)

    Rishe, Naphtali; Barton, David; Urban, Frank; Chekmasov, Maxim; Martinez, Maria; Alvarez, Elms; Gutierrez, Martha; Pardo, Philippe

    1998-01-01

    The High Performance Database Research Center at Florida International University is completing the development of a highly parallel database system based on the semantic/object-oriented approach. This system provides exceptional usability and flexibility. It allows shorter application design and programming cycles and gives the user control via an intuitive information structure. It empowers the end-user to pose complex ad hoc decision support queries. Superior efficiency is provided through a high level of optimization, which is transparent to the user. Manifold reduction in storage size is allowed for many applications. This system allows for operability via internet browsers. The system will be used for the NASA Applications Center program to store remote sensing data, as well as for Earth Science applications.

  5. High performance anode for advanced Li batteries

    Energy Technology Data Exchange (ETDEWEB)

    Lake, Carla [Applied Sciences, Inc., Cedarville, OH (United States)

    2015-11-02

    The overall objective of this Phase I SBIR effort was to advance the manufacturing technology for ASI’s Si-CNF high-performance anode by creating a framework for large volume production and utilization of low-cost Si-coated carbon nanofibers (Si-CNF) for the battery industry. This project explores the use of nano-structured silicon which is deposited on a nano-scale carbon filament to achieve the benefits of high cycle life and high charge capacity without the consequent fading of, or failure in the capacity resulting from stress-induced fracturing of the Si particles and de-coupling from the electrode. ASI’s patented coating process distinguishes itself from others, in that it is highly reproducible, readily scalable and results in a Si-CNF composite structure containing 25-30% silicon, with a compositionally graded interface at the Si-CNF interface that significantly improve cycling stability and enhances adhesion of silicon to the carbon fiber support. In Phase I, the team demonstrated the production of the Si-CNF anode material can successfully be transitioned from a static bench-scale reactor into a fluidized bed reactor. In addition, ASI made significant progress in the development of low cost, quick testing methods which can be performed on silicon coated CNFs as a means of quality control. To date, weight change, density, and cycling performance were the key metrics used to validate the high performance anode material. Under this effort, ASI made strides to establish a quality control protocol for the large volume production of Si-CNFs and has identified several key technical thrusts for future work. Using the results of this Phase I effort as a foundation, ASI has defined a path forward to commercialize and deliver high volume and low-cost production of SI-CNF material for anodes in Li-ion batteries.

  6. High performance light-colored nitrile-butadiene rubber nanocomposites.

    Science.gov (United States)

    Lei, Yanda; Guo, Baochun; Chen, Feng; Zhu, Lixin; Zhou, Wenyou; Jia, Demin

    2011-12-01

    High mechanical performance nitrile-butadiene rubber (NBR) with light color was fabricated by the method of in situ formation of zinc disorbate (ZDS) or magnesium disorbate (MDS). The in situ formed ZDS and its polymerization via internal mixing was confirmed by X-ray diffaraction. The mechanical properties, ageing resistance, morphology and the dynamic mechanical analysis were fully studied. It was found that with increasing loading of metallic disorbate both the curing rate and the ionic crosslink density was largely increased. The modulus, tensile strength and tear strength were largely increased. With a comparison between internal mixing and opening mixing, the mechanical performance for the former one was obviously better than the latter one. The high performance was ascribed to the finely dispersion nano domains with irregular shape and obscure interfacial structures. Except for the NBR vulcanizate with a high loading of MDS, the others' ageing resistance with incorporation of these two metallic disorbate was found to be good. Dynamic mechanical analysis (DMA) showed that, with increasing loading of metallic disorbate, the highly increased storage modulus above -20 degrees C, the up-shifted glass transition temperature (Tg) and the reduced mechanical loss were ascribed to strengthened interfacial interactions. PMID:22408977

  7. SISYPHUS: A high performance seismic inversion factory

    Science.gov (United States)

    Gokhberg, Alexey; Simutė, Saulė; Boehm, Christian; Fichtner, Andreas

    2016-04-01

    In the recent years the massively parallel high performance computers became the standard instruments for solving the forward and inverse problems in seismology. The respective software packages dedicated to forward and inverse waveform modelling specially designed for such computers (SPECFEM3D, SES3D) became mature and widely available. These packages achieve significant computational performance and provide researchers with an opportunity to solve problems of bigger size at higher resolution within a shorter time. However, a typical seismic inversion process contains various activities that are beyond the common solver functionality. They include management of information on seismic events and stations, 3D models, observed and synthetic seismograms, pre-processing of the observed signals, computation of misfits and adjoint sources, minimization of misfits, and process workflow management. These activities are time consuming, seldom sufficiently automated, and therefore represent a bottleneck that can substantially offset performance benefits provided by even the most powerful modern supercomputers. Furthermore, a typical system architecture of modern supercomputing platforms is oriented towards the maximum computational performance and provides limited standard facilities for automation of the supporting activities. We present a prototype solution that automates all aspects of the seismic inversion process and is tuned for the modern massively parallel high performance computing systems. We address several major aspects of the solution architecture, which include (1) design of an inversion state database for tracing all relevant aspects of the entire solution process, (2) design of an extensible workflow management framework, (3) integration with wave propagation solvers, (4) integration with optimization packages, (5) computation of misfits and adjoint sources, and (6) process monitoring. The inversion state database represents a hierarchical structure with

  8. NCI's Transdisciplinary High Performance Scientific Data Platform

    Science.gov (United States)

    Evans, Ben; Antony, Joseph; Bastrakova, Irina; Car, Nicholas; Cox, Simon; Druken, Kelsey; Evans, Bradley; Fraser, Ryan; Ip, Alex; Kemp, Carina; King, Edward; Minchin, Stuart; Larraondo, Pablo; Pugh, Tim; Richards, Clare; Santana, Fabiana; Smillie, Jon; Trenham, Claire; Wang, Jingbo; Wyborn, Lesley

    2016-04-01

    The Australian National Computational Infrastructure (NCI) manages Earth Systems data collections sourced from several domains and organisations onto a single High Performance Data (HPD) Node to further Australia's national priority research and innovation agenda. The NCI HPD Node has rapidly established its value, currently managing over 10 PBytes of datasets from collections that span a wide range of disciplines including climate, weather, environment, geoscience, geophysics, water resources and social sciences. Importantly, in order to facilitate broad user uptake, maximise reuse and enable transdisciplinary access through software and standardised interfaces, the datasets, associated information systems and processes have been incorporated into the design and operation of a unified platform that NCI has called, the National Environmental Research Data Interoperability Platform (NERDIP). The key goal of the NERDIP is to regularise data access so that it is easily discoverable, interoperable for different domains and enabled for high performance methods. It adopts and implements international standards and data conventions, and promotes scientific integrity within a high performance computing and data analysis environment. NCI has established a rich and flexible computing environment to access to this data, through the NCI supercomputer; a private cloud that supports both domain focused virtual laboratories and in-common interactive analysis interfaces; as well as remotely through scalable data services. Data collections of this importance must be managed with careful consideration of both their current use and the needs of the end-communities, as well as its future potential use, such as transitioning to more advanced software and improved methods. It is therefore critical that the data platform is both well-managed and trusted for stable production use (including transparency and reproducibility), agile enough to incorporate new technological advances and

  9. Effect of reversed phase high performance liquid chromatographic method for the detection of several kinds of important metal elemens in food%反相高效液相色谱法同时测定食品中的几种重要金属元素

    Institute of Scientific and Technical Information of China (English)

    杨林飞; 胡卓; 方英; 钟燕; 胡迎春; 张建华

    2014-01-01

    目的:验证用反相高效液相色谱法同时测定食品中的几种金属元素的效果。方法用2-2-噻唑偶氮,5-二乙氨基酚为柱前衍生试剂,甲醇(内含0.30%磷酸酸)和pH4.6磷酸-磷酸钠缓冲溶液梯度洗脱为流动相,Waters Nova- Pak-18液相色谱柱为固定相。紫外二极管矩阵检测器检测,反相高效液相色谱法分离测定食品中铁、钴、镍、铜、锌和锰。结果根据信噪S/N=4.0各种金属离子的检测限分别为:铁4.0µg/L,钴5.0/Lµg,镍4.8µg/L ,铜3.0µg/L,锌4.8µg/L,锰6.0µg/L,本方法相对标准偏差在2.0%~3.8%之间,标准回收率在95%~108%。结论本方法可用于食品中痕量铁、钴、镍、铜、锌、锰的测定,结果令人满意。%Objective To verify the effect of reversed phase high performance liquid chromatographic method for the detection of several kinds of metal elements in food. Methods 2- 2 Lhiazole azo, 5- two amino phenol were used as pre column derivative reagent, methanol (conLaining0.30% phosphoric acid ) and pH4.6 phosphoric acid- sodium phosphate buffer solution were used as the mobile phase gradient elution, Waters Nova- Pak- 18 liquid chromatography column was used as stationary phase. UV diode array detector and reversed phase high performance liquid chromatographic method were used to separate and detect the iron, cobalt, nickel, copper, zinc and manganese in food. Results According to the letter S/ N = 4, the detection limit of the metal ions of iron, cobalt, nickel, copper, zinc and manganese was 4.0 µg/L, 5.0µg/L, 4.8µg/ L, 3.0µg/ L, 4.8µg/ L, 6.0µg/ L, respectively. The relative standard deviation was 2.0%~3.8%, standard recovery rate was 95%- 108%. Conclusion The method can be used to detect the trace of iron, cobalt, nickel, copper, zinc, manganese in food with satisfactory results.

  10. Low-Cost High-Performance MRI

    Science.gov (United States)

    Sarracanie, Mathieu; Lapierre, Cristen D.; Salameh, Najat; Waddington, David E. J.; Witzel, Thomas; Rosen, Matthew S.

    2015-10-01

    Magnetic Resonance Imaging (MRI) is unparalleled in its ability to visualize anatomical structure and function non-invasively with high spatial and temporal resolution. Yet to overcome the low sensitivity inherent in inductive detection of weakly polarized nuclear spins, the vast majority of clinical MRI scanners employ superconducting magnets producing very high magnetic fields. Commonly found at 1.5-3 tesla (T), these powerful magnets are massive and have very strict infrastructure demands that preclude operation in many environments. MRI scanners are costly to purchase, site, and maintain, with the purchase price approaching $1 M per tesla (T) of magnetic field. We present here a remarkably simple, non-cryogenic approach to high-performance human MRI at ultra-low magnetic field, whereby modern under-sampling strategies are combined with fully-refocused dynamic spin control using steady-state free precession techniques. At 6.5 mT (more than 450 times lower than clinical MRI scanners) we demonstrate (2.5 × 3.5 × 8.5) mm3 imaging resolution in the living human brain using a simple, open-geometry electromagnet, with 3D image acquisition over the entire brain in 6 minutes. We contend that these practical ultra-low magnetic field implementations of MRI (MRI, providing clinically relevant images and setting new standards for affordable (<$50,000) and robust portable devices.

  11. Automatic Energy Schemes for High Performance Applications

    Energy Technology Data Exchange (ETDEWEB)

    Sundriyal, Vaibhav [Iowa State Univ., Ames, IA (United States)

    2013-01-01

    Although high-performance computing traditionally focuses on the efficient execution of large-scale applications, both energy and power have become critical concerns when approaching exascale. Drastic increases in the power consumption of supercomputers affect significantly their operating costs and failure rates. In modern microprocessor architectures, equipped with dynamic voltage and frequency scaling (DVFS) and CPU clock modulation (throttling), the power consumption may be controlled in software. Additionally, network interconnect, such as Infiniband, may be exploited to maximize energy savings while the application performance loss and frequency switching overheads must be carefully balanced. This work first studies two important collective communication operations, all-to-all and allgather and proposes energy saving strategies on the per-call basis. Next, it targets point-to-point communications to group them into phases and apply frequency scaling to them to save energy by exploiting the architectural and communication stalls. Finally, it proposes an automatic runtime system which combines both collective and point-to-point communications into phases, and applies throttling to them apart from DVFS to maximize energy savings. The experimental results are presented for NAS parallel benchmark problems as well as for the realistic parallel electronic structure calculations performed by the widely used quantum chemistry package GAMESS. Close to the maximum energy savings were obtained with a substantially low performance loss on the given platform.

  12. Initial rheological description of high performance concretes

    Directory of Open Access Journals (Sweden)

    Alessandra Lorenzetti de Castro

    2006-12-01

    Full Text Available Concrete is defined as a composite material and, in rheological terms, it can be understood as a concentrated suspension of solid particles (aggregates in a viscous liquid (cement paste. On a macroscopic scale, concrete flows as a liquid. It is known that the rheological behavior of the concrete is close to that of a Bingham fluid and two rheological parameters regarding its description are needed: yield stress and plastic viscosity. The aim of this paper is to present the initial rheological description of high performance concretes using the modified slump test. According to the results, an increase of yield stress was observed over time, while a slight variation in plastic viscosity was noticed. The incorporation of silica fume showed changes in the rheological properties of fresh concrete. The behavior of these materials also varied with the mixing procedure employed in their production. The addition of superplasticizer meant that there was a large reduction in the mixture's yield stress, while plastic viscosity remained practically constant.

  13. Development of a High Performance Spacer Grid

    Energy Technology Data Exchange (ETDEWEB)

    Song, Kee Nam; Song, K. N.; Yoon, K. H. (and others)

    2007-03-15

    A spacer grid in a LWR fuel assembly is a key structural component to support fuel rods and to enhance the heat transfer from the fuel rod to the coolant. In this research, the main research items are the development of inherent and high performance spacer grid shapes, the establishment of mechanical/structural analysis and test technology, and the set-up of basic test facilities for the spacer grid. The main research areas and results are as follows. 1. 18 different spacer grid candidates have been invented and applied for domestic and US patents. Among the candidates 16 are chosen from the patent. 2. Two kinds of spacer grids are finally selected for the advanced LWR fuel after detailed performance tests on the candidates and commercial spacer grids from a mechanical/structural point of view. According to the test results the features of the selected spacer grids are better than those of the commercial spacer grids. 3. Four kinds of basic test facilities are set up and the relevant test technologies are established. 4. Mechanical/structural analysis models and technology for spacer grid performance are developed and the analysis results are compared with the test results to enhance the reliability of the models.

  14. High performance composites with active stiffness control.

    Science.gov (United States)

    Tridech, Charnwit; Maples, Henry A; Robinson, Paul; Bismarck, Alexander

    2013-09-25

    High performance carbon fiber reinforced composites with controllable stiffness could revolutionize the use of composite materials in structural applications. Here we describe a structural material, which has a stiffness that can be actively controlled on demand. Such a material could have applications in morphing wings or deployable structures. A carbon fiber reinforced-epoxy composite is described that can undergo an 88% reduction in flexural stiffness at elevated temperatures and fully recover when cooled, with no discernible damage or loss in properties. Once the stiffness has been reduced, the required deformations can be achieved at much lower actuation forces. For this proof-of-concept study a thin polyacrylamide (PAAm) layer was electrocoated onto carbon fibers that were then embedded into an epoxy matrix via resin infusion. Heating the PAAm coating above its glass transition temperature caused it to soften and allowed the fibers to slide within the matrix. To produce the stiffness change the carbon fibers were used as resistance heating elements by passing a current through them. When the PAAm coating had softened, the ability of the interphase to transfer load to the fibers was significantly reduced, greatly lowering the flexural stiffness of the composite. By changing the moisture content in PAAm fiber coating, the temperature at which the PAAm softens and the composites undergo a reduction in stiffness can be tuned. PMID:23978266

  15. RISC Processors and High Performance Computing

    Science.gov (United States)

    Saini, Subhash; Bailey, David H.; Lasinski, T. A. (Technical Monitor)

    1995-01-01

    In this tutorial, we will discuss top five current RISC microprocessors: The IBM Power2, which is used in the IBM RS6000/590 workstation and in the IBM SP2 parallel supercomputer, the DEC Alpha, which is in the DEC Alpha workstation and in the Cray T3D; the MIPS R8000, which is used in the SGI Power Challenge; the HP PA-RISC 7100, which is used in the HP 700 series workstations and in the Convex Exemplar; and the Cray proprietary processor, which is used in the new Cray J916. The architecture of these microprocessors will first be presented. The effective performance of these processors will then be compared, both by citing standard benchmarks and also in the context of implementing a real applications. In the process, different programming models such as data parallel (CM Fortran and HPF) and message passing (PVM and MPI) will be introduced and compared. The latest NAS Parallel Benchmark (NPB) absolute performance and performance per dollar figures will be presented. The next generation of the NP13 will also be described. The tutorial will conclude with a discussion of general trends in the field of high performance computing, including likely future developments in hardware and software technology, and the relative roles of vector supercomputers tightly coupled parallel computers, and clusters of workstations. This tutorial will provide a unique cross-machine comparison not available elsewhere.

  16. Low-Cost High-Performance MRI.

    Science.gov (United States)

    Sarracanie, Mathieu; LaPierre, Cristen D; Salameh, Najat; Waddington, David E J; Witzel, Thomas; Rosen, Matthew S

    2015-01-01

    Magnetic Resonance Imaging (MRI) is unparalleled in its ability to visualize anatomical structure and function non-invasively with high spatial and temporal resolution. Yet to overcome the low sensitivity inherent in inductive detection of weakly polarized nuclear spins, the vast majority of clinical MRI scanners employ superconducting magnets producing very high magnetic fields. Commonly found at 1.5-3 tesla (T), these powerful magnets are massive and have very strict infrastructure demands that preclude operation in many environments. MRI scanners are costly to purchase, site, and maintain, with the purchase price approaching $1 M per tesla (T) of magnetic field. We present here a remarkably simple, non-cryogenic approach to high-performance human MRI at ultra-low magnetic field, whereby modern under-sampling strategies are combined with fully-refocused dynamic spin control using steady-state free precession techniques. At 6.5 mT (more than 450 times lower than clinical MRI scanners) we demonstrate (2.5 × 3.5 × 8.5) mm(3) imaging resolution in the living human brain using a simple, open-geometry electromagnet, with 3D image acquisition over the entire brain in 6 minutes. We contend that these practical ultra-low magnetic field implementations of MRI (<10 mT) will complement traditional MRI, providing clinically relevant images and setting new standards for affordable (<$50,000) and robust portable devices. PMID:26469756

  17. Durability of High Performance Color Hardener

    Institute of Scientific and Technical Information of China (English)

    MA Bao-guo; DONG Rong-zhen; ZHU Hong-bo; ZHANG Li; JIAN Shou-wei

    2004-01-01

    The properties of high performance color hardener (HPCH) and the mechanism were studied.HPCH is a composite system, which is composed of cementitious and auxiliary cementing materials, composite additives, abrasion resistance component (aggregate) and pigment. The porosity and pore structure of the material are obviously improved due to the activation, filling and adsorption of auxiliary cementing materials, thus resulting in a great increase of binding capacity for ions in HPCH and the obstacles of ion migrating.The density of material structure, bonding capacity of cementitious material to the abrasion-resisting component and the corrosion resistance are greatly and effectively improved by adding the auxiliary cementing materials and compound additives. According to the tests of dry shrinkage, sulphate resistance, chloride permeability and Ca(OH)2 content distribution, the property superiority of HPCH is analyzed.The mechanism of materials modification of HPCH is explained from the microscopic point of view by testing the pore structure and pore distribution via the mercury intrusion pressure method.

  18. Towards high performance inverted polymer solar cells

    Science.gov (United States)

    Gong, Xiong

    2013-03-01

    Bulk heterojunction polymer solar cells that can be fabricated by solution processing techniques are under intense investigation in both academic institutions and industrial companies because of their potential to enable mass production of flexible and cost-effective alternative to silicon-based electronics. Despite the envisioned advantages and recent technology advances, so far the performance of polymer solar cells is still inferior to inorganic counterparts in terms of the efficiency and stability. There are many factors limiting the performance of polymer solar cells. Among them, the optical and electronic properties of materials in the active layer, device architecture and elimination of PEDOT:PSS are the most determining factors in the overall performance of polymer solar cells. In this presentation, I will present how we approach high performance of polymer solar cells. For example, by developing novel materials, fabrication polymer photovoltaic cells with an inverted device structure and elimination of PEDOT:PSS, we were able to observe over 8.4% power conversion efficiency from inverted polymer solar cells.

  19. High-performance laboratories and cleanrooms

    Energy Technology Data Exchange (ETDEWEB)

    Tschudi, William; Sartor, Dale; Mills, Evan; Xu, Tengfang

    2002-07-01

    The California Energy Commission sponsored this roadmap to guide energy efficiency research and deployment for high performance cleanrooms and laboratories. Industries and institutions utilizing these building types (termed high-tech buildings) have played an important part in the vitality of the California economy. This roadmap's key objective to present a multi-year agenda to prioritize and coordinate research efforts. It also addresses delivery mechanisms to get the research products into the market. Because of the importance to the California economy, it is appropriate and important for California to take the lead in assessing the energy efficiency research needs, opportunities, and priorities for this market. In addition to the importance to California's economy, energy demand for this market segment is large and growing (estimated at 9400 GWH for 1996, Mills et al. 1996). With their 24hr. continuous operation, high tech facilities are a major contributor to the peak electrical demand. Laboratories and cleanrooms constitute the high tech building market, and although each building type has its unique features, they are similar in that they are extremely energy intensive, involve special environmental considerations, have very high ventilation requirements, and are subject to regulations--primarily safety driven--that tend to have adverse energy implications. High-tech buildings have largely been overlooked in past energy efficiency research. Many industries and institutions utilize laboratories and cleanrooms. As illustrated, there are many industries operating cleanrooms in California. These include semiconductor manufacturing, semiconductor suppliers, pharmaceutical, biotechnology, disk drive manufacturing, flat panel displays, automotive, aerospace, food, hospitals, medical devices, universities, and federal research facilities.

  20. Scalable resource management in high performance computers.

    Energy Technology Data Exchange (ETDEWEB)

    Frachtenberg, E. (Eitan); Petrini, F. (Fabrizio); Fernandez Peinador, J. (Juan); Coll, S. (Salvador)

    2002-01-01

    Clusters of workstations have emerged as an important platform for building cost-effective, scalable and highly-available computers. Although many hardware solutions are available today, the largest challenge in making large-scale clusters usable lies in the system software. In this paper we present STORM, a resource management tool designed to provide scalability, low overhead and the flexibility necessary to efficiently support and analyze a wide range of job scheduling algorithms. STORM achieves these feats by closely integrating the management daemons with the low-level features that are common in state-of-the-art high-performance system area networks. The architecture of STORM is based on three main technical innovations. First, a sizable part of the scheduler runs in the thread processor located on the network interface. Second, we use hardware collectives that are highly scalable both for implementing control heartbeats and to distribute the binary of a parallel job in near-constant time, irrespective of job and machine sizes. Third, we use an I/O bypass protocol that allows fast data movements from the file system to the communication buffers in the network interface and vice versa. The experimental results show that STORM can launch a job with a binary of 12MB on a 64 processor/32 node cluster in less than 0.25 sec on an empty network, in less than 0.45 sec when all the processors are busy computing other jobs, and in less than 0.65 sec when the network is flooded with a background traffic. This paper provides experimental and analytical evidence that these results scale to a much larger number of nodes. To the best of our knowledge, STORM is at least two orders of magnitude faster than existing production schedulers in launching jobs, performing resource management tasks and gang scheduling.

  1. High-Performance Monopropellants and Catalysts Evaluated

    Science.gov (United States)

    Reed, Brian D.

    2004-01-01

    The NASA Glenn Research Center is sponsoring efforts to develop advanced monopropellant technology. The focus has been on monopropellant formulations composed of an aqueous solution of hydroxylammonium nitrate (HAN) and a fuel component. HAN-based monopropellants do not have a toxic vapor and do not need the extraordinary procedures for storage, handling, and disposal required of hydrazine (N2H4). Generically, HAN-based monopropellants are denser and have lower freezing points than N2H4. The performance of HAN-based monopropellants depends on the selection of fuel, the HAN-to-fuel ratio, and the amount of water in the formulation. HAN-based monopropellants are not seen as a replacement for N2H4 per se, but rather as a propulsion option in their own right. For example, HAN-based monopropellants would prove beneficial to the orbit insertion of small, power-limited satellites because of this propellant's high performance (reduced system mass), high density (reduced system volume), and low freezing point (elimination of tank and line heaters). Under a Glenn-contracted effort, Aerojet Redmond Rocket Center conducted testing to provide the foundation for the development of monopropellant thrusters with an I(sub sp) goal of 250 sec. A modular, workhorse reactor (representative of a 1-lbf thruster) was used to evaluate HAN formulations with catalyst materials. Stoichiometric, oxygen-rich, and fuelrich formulations of HAN-methanol and HAN-tris(aminoethyl)amine trinitrate were tested to investigate the effects of stoichiometry on combustion behavior. Aerojet found that fuelrich formulations degrade the catalyst and reactor faster than oxygen-rich and stoichiometric formulations do. A HAN-methanol formulation with a theoretical Isp of 269 sec (designated HAN269MEO) was selected as the baseline. With a combustion efficiency of at least 93 percent demonstrated for HAN-based monopropellants, HAN269MEO will meet the I(sub sp) 250 sec goal.

  2. Study of High Performance Coronagraphic Techniques

    Science.gov (United States)

    Crane, Phil (Technical Monitor); Tolls, Volker

    2004-01-01

    The goal of the Study of High Performance Coronagraphic Techniques project (called CoronaTech) is: 1) to verify the Labeyrie multi-step speckle reduction method and 2) to develop new techniques to manufacture soft-edge occulter masks preferably with Gaussian absorption profile. In a coronagraph, the light from a bright host star which is centered on the optical axis in the image plane is blocked by an occulter centered on the optical axis while the light from a planet passes the occulter (the planet has a certain minimal distance from the optical axis). Unfortunately, stray light originating in the telescope and subsequent optical elements is not completely blocked causing a so-called speckle pattern in the image plane of the coronagraph limiting the sensitivity of the system. The sensitivity can be increased significantly by reducing the amount of speckle light. The Labeyrie multi-step speckle reduction method implements one (or more) phase correction steps to suppress the unwanted speckle light. In each step, the stray light is rephased and then blocked with an additional occulter which affects the planet light (or other companion) only slightly. Since the suppression is still not complete, a series of steps is required in order to achieve significant suppression. The second part of the project is the development of soft-edge occulters. Simulations have shown that soft-edge occulters show better performance in coronagraphs than hard-edge occulters. In order to utilize the performance gain of soft-edge occulters. fabrication methods have to be developed to manufacture these occulters according to the specification set forth by the sensitivity requirements of the coronagraph.

  3. Ultra high performance concrete dematerialization study

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-03-01

    Concrete is the most widely used building material in the world and its use is expected to grow. It is well recognized that the production of portland cement results in the release of large amounts of carbon dioxide, a greenhouse gas (GHG). The main challenge facing the industry is to produce concrete in an environmentally sustainable manner. Reclaimed industrial by-proudcts such as fly ash, silica fume and slag can reduce the amount of portland cement needed to make concrete, thereby reducing the amount of GHGs released to the atmosphere. The use of these supplementary cementing materials (SCM) can also enhance the long-term strength and durability of concrete. The intention of the EcoSmart{sup TM} Concrete Project is to develop sustainable concrete through innovation in supply, design and construction. In particular, the project focuses on finding a way to minimize the GHG signature of concrete by maximizing the replacement of portland cement in the concrete mix with SCM while improving the cost, performance and constructability. This paper describes the use of Ductal{sup R} Ultra High Performance Concrete (UHPC) for ramps in a condominium. It examined the relationship between the selection of UHPC and the overall environmental performance, cost, constructability maintenance and operational efficiency as it relates to the EcoSmart Program. The advantages and challenges of using UHPC were outlined. In addition to its very high strength, UHPC has been shown to have very good potential for GHG emission reduction due to the reduced material requirements, reduced transport costs and increased SCM content. refs., tabs., figs.

  4. High-performance phase-field modeling

    KAUST Repository

    Vignal, Philippe

    2015-04-27

    Many processes in engineering and sciences involve the evolution of interfaces. Among the mathematical frameworks developed to model these types of problems, the phase-field method has emerged as a possible solution. Phase-fields nonetheless lead to complex nonlinear, high-order partial differential equations, whose solution poses mathematical and computational challenges. Guaranteeing some of the physical properties of the equations has lead to the development of efficient algorithms and discretizations capable of recovering said properties by construction [2, 5]. This work builds-up on these ideas, and proposes novel discretization strategies that guarantee numerical energy dissipation for both conserved and non-conserved phase-field models. The temporal discretization is based on a novel method which relies on Taylor series and ensures strong energy stability. It is second-order accurate, and can also be rendered linear to speed-up the solution process [4]. The spatial discretization relies on Isogeometric Analysis, a finite element method that possesses the k-refinement technology and enables the generation of high-order, high-continuity basis functions. These basis functions are well suited to handle the high-order operators present in phase-field models. Two-dimensional and three dimensional results of the Allen-Cahn, Cahn-Hilliard, Swift-Hohenberg and phase-field crystal equation will be presented, which corroborate the theoretical findings, and illustrate the robustness of the method. Results related to more challenging examples, namely the Navier-Stokes Cahn-Hilliard and a diusion-reaction Cahn-Hilliard system, will also be presented. The implementation was done in PetIGA and PetIGA-MF, high-performance Isogeometric Analysis frameworks [1, 3], designed to handle non-linear, time-dependent problems.

  5. Pressurized metallurgy for high performance special steels and alloys

    Science.gov (United States)

    Jiang, Z. H.; Zhu, H. C.; Li, H. B.; L1, Y.; Liu, F. B.

    2016-07-01

    The pressure is one of the basic parameters which greatly influences the metallurgical reaction process and solidification of steels and alloys. In this paper the history and present situation of research and application of pressurized metallurgy, especially pressurized metallurgy for special steels and alloys have been briefly reviewed. In the following part the physical chemistry of pressurized metallurgy is summarized. It is shown that pressurizing may change the conditions of chemical reaction in thermodynamics and kinetics due to the pressure effect on gas volume, solubility of gas and volatile element in metal melt, activity or activity coefficient of components, and change the physical and chemical properties of metal melt, heat transfer coefficient between mould and ingot, thus greatly influencing phase transformation during the solidification process and the solidification structure, such as increasing the solidification nucleation rate, reducing the critical nucleation radius, accelerating the solidification speed and significant macro/micro-structure refinement, and eliminating shrinkage, porosity and segregation and other casting defects. In the third part the research works of pressured metallurgy performed by the Northeastern University including establishment of pressurized induction melting (PIM) and pressurized electroslag remelting (PESR) equipments and development of high nitrogen steels under pressure are described in detail. Finally, it is considered in the paper that application of pressurized metallurgy in manufacture of high performance special steels and alloys is a relatively new research area, and its application prospects will be very broad and bright.

  6. Nanomechanical analysis of high performance materials

    CERN Document Server

    2014-01-01

    This book is intended for researchers who are interested in investigating the nanomechanical properties of materials using advanced instrumentation techniques. The chapters of the book are written in an easy-to-follow format, just like solved examples. The book comprehensively covers a broad range of materials such as polymers, ceramics, hybrids, biomaterials, metal oxides, nanoparticles, minerals, carbon nanotubes and welded joints. Each chapter describes the application of techniques on the selected material and also mentions the methodology adopted for the extraction of information from the raw data. This is a unique book in which both equipment manufacturers and equipment users have contributed chapters. Novices will learn the techniques directly from the inventors and senior researchers will gain in-depth information on the new technologies that are suitable for advanced analysis. On the one hand, fundamental concepts that are needed to understand the nanomechanical behavior of materials is included in t...

  7. High-performance THz metamaterial absorber

    CERN Document Server

    Zhu, Jianfei; Sun, Wujiong; Ding, Fei; He, Qiong; Zhou, Lei; Ma, Yungui

    2014-01-01

    We demonstrated an ultra-broadband, polarization-insensitive and wide-angle metamaterial absorber for terahertz (THz) frequencies using arrays of truncated pyramid unit structure made of metal-dielectric multilayer composite. In our design each sub-layer behaving as an effective waveguide is gradually modified in their lateral width to realize a wideband response by effectively stitching together the resonance bands of different waveguide modes. Experimentally, our five layer sample with a total thickness 21um is capable of producing a large absorptivity above 80% from 0.7 to 2.3 THz up to the maximum measurement angle 40{\\deg}. The full absorption width at half maximum (FWHM) of our device is around 127%, greater than those previously reported for THz frequencies. Our absorber design has high practical feasibility and can be easily integrated with the semiconductor technology to make high efficient THz-oriented devices.

  8. High Performance Computing in Science and Engineering '15 : Transactions of the High Performance Computing Center

    CERN Document Server

    Kröner, Dietmar; Resch, Michael

    2016-01-01

    This book presents the state-of-the-art in supercomputer simulation. It includes the latest findings from leading researchers using systems from the High Performance Computing Center Stuttgart (HLRS) in 2015. The reports cover all fields of computational science and engineering ranging from CFD to computational physics and from chemistry to computer science with a special emphasis on industrially relevant applications. Presenting findings of one of Europe’s leading systems, this volume covers a wide variety of applications that deliver a high level of sustained performance. The book covers the main methods in high-performance computing. Its outstanding results in achieving the best performance for production codes are of particular interest for both scientists and engineers. The book comes with a wealth of color illustrations and tables of results.

  9. High Efficiency, High Performance Clothes Dryer

    Energy Technology Data Exchange (ETDEWEB)

    Peter Pescatore; Phil Carbone

    2005-03-31

    This program covered the development of two separate products; an electric heat pump clothes dryer and a modulating gas dryer. These development efforts were independent of one another and are presented in this report in two separate volumes. Volume 1 details the Heat Pump Dryer Development while Volume 2 details the Modulating Gas Dryer Development. In both product development efforts, the intent was to develop high efficiency, high performance designs that would be attractive to US consumers. Working with Whirlpool Corporation as our commercial partner, TIAX applied this approach of satisfying consumer needs throughout the Product Development Process for both dryer designs. Heat pump clothes dryers have been in existence for years, especially in Europe, but have not been able to penetrate the market. This has been especially true in the US market where no volume production heat pump dryers are available. The issue has typically been around two key areas: cost and performance. Cost is a given in that a heat pump clothes dryer has numerous additional components associated with it. While heat pump dryers have been able to achieve significant energy savings compared to standard electric resistance dryers (over 50% in some cases), designs to date have been hampered by excessively long dry times, a major market driver in the US. The development work done on the heat pump dryer over the course of this program led to a demonstration dryer that delivered the following performance characteristics: (1) 40-50% energy savings on large loads with 35 F lower fabric temperatures and similar dry times; (2) 10-30 F reduction in fabric temperature for delicate loads with up to 50% energy savings and 30-40% time savings; (3) Improved fabric temperature uniformity; and (4) Robust performance across a range of vent restrictions. For the gas dryer development, the concept developed was one of modulating the gas flow to the dryer throughout the dry cycle. Through heat modulation in a

  10. High Performance Commercial Fenestration Framing Systems

    Energy Technology Data Exchange (ETDEWEB)

    Mike Manteghi; Sneh Kumar; Joshua Early; Bhaskar Adusumalli

    2010-01-31

    A major objective of the U.S. Department of Energy is to have a zero energy commercial building by the year 2025. Windows have a major influence on the energy performance of the building envelope as they control over 55% of building energy load, and represent one important area where technologies can be developed to save energy. Aluminum framing systems are used in over 80% of commercial fenestration products (i.e. windows, curtain walls, store fronts, etc.). Aluminum framing systems are often required in commercial buildings because of their inherent good structural properties and long service life, which is required from commercial and architectural frames. At the same time, they are lightweight and durable, requiring very little maintenance, and offer design flexibility. An additional benefit of aluminum framing systems is their relatively low cost and easy manufacturability. Aluminum, being an easily recyclable material, also offers sustainable features. However, from energy efficiency point of view, aluminum frames have lower thermal performance due to the very high thermal conductivity of aluminum. Fenestration systems constructed of aluminum alloys therefore have lower performance in terms of being effective barrier to energy transfer (heat loss or gain). Despite the lower energy performance, aluminum is the choice material for commercial framing systems and dominates the commercial/architectural fenestration market because of the reasons mentioned above. In addition, there is no other cost effective and energy efficient replacement material available to take place of aluminum in the commercial/architectural market. Hence it is imperative to improve the performance of aluminum framing system to improve the energy performance of commercial fenestration system and in turn reduce the energy consumption of commercial building and achieve zero energy building by 2025. The objective of this project was to develop high performance, energy efficient commercial

  11. Integrating advanced facades into high performance buildings

    Energy Technology Data Exchange (ETDEWEB)

    Selkowitz, Stephen E.

    2001-05-01

    Glass is a remarkable material but its functionality is significantly enhanced when it is processed or altered to provide added intrinsic capabilities. The overall performance of glass elements in a building can be further enhanced when they are designed to be part of a complete facade system. Finally the facade system delivers the greatest performance to the building owner and occupants when it becomes an essential element of a fully integrated building design. This presentation examines the growing interest in incorporating advanced glazing elements into more comprehensive facade and building systems in a manner that increases comfort, productivity and amenity for occupants, reduces operating costs for building owners, and contributes to improving the health of the planet by reducing overall energy use and negative environmental impacts. We explore the role of glazing systems in dynamic and responsive facades that provide the following functionality: Enhanced sun protection and cooling load control while improving thermal comfort and providing most of the light needed with daylighting; Enhanced air quality and reduced cooling loads using natural ventilation schemes employing the facade as an active air control element; Reduced operating costs by minimizing lighting, cooling and heating energy use by optimizing the daylighting-thermal tradeoffs; Net positive contributions to the energy balance of the building using integrated photovoltaic systems; Improved indoor environments leading to enhanced occupant health, comfort and performance. In addressing these issues facade system solutions must, of course, respect the constraints of latitude, location, solar orientation, acoustics, earthquake and fire safety, etc. Since climate and occupant needs are dynamic variables, in a high performance building the facade solution have the capacity to respond and adapt to these variable exterior conditions and to changing occupant needs. This responsive performance capability

  12. High Performance Home Building Guide for Habitat for Humanity Affiliates

    Energy Technology Data Exchange (ETDEWEB)

    Lindsey Marburger

    2010-10-01

    This guide covers basic principles of high performance Habitat construction, steps to achieving high performance Habitat construction, resources to help improve building practices, materials, etc., and affiliate profiles and recommendations.

  13. The bimevox series: a new family of high performances oxide ion conductors

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, F.; Boivin, J.C.; Mairesse, G.; Nowogrocki, G. (Lab. de Cristallochimie et Physiochimie du Solide, E.N.S.C. et U.S.T. de Lille, 59 - Villeneuve d' Ascq (France))

    1990-08-01

    A new family of oxygen anionic conductors, exhibiting high performances at low temperature, has been prepared and characterized. They derive from Bi{sub 4}V{sub 2}O{sub 11} by partial substitution of vanadium by other metallic ions (BIMEVOX). Results dealing with the copper substituant (BICUVOX) are detailed.

  14. High-performance commercial building systems

    Energy Technology Data Exchange (ETDEWEB)

    Selkowitz, Stephen

    2003-10-01

    This report summarizes key technical accomplishments resulting from the three year PIER-funded R&D program, ''High Performance Commercial Building Systems'' (HPCBS). The program targets the commercial building sector in California, an end-use sector that accounts for about one-third of all California electricity consumption and an even larger fraction of peak demand, at a cost of over $10B/year. Commercial buildings also have a major impact on occupant health, comfort and productivity. Building design and operations practices that influence energy use are deeply engrained in a fragmented, risk-averse industry that is slow to change. Although California's aggressive standards efforts have resulted in new buildings designed to use less energy than those constructed 20 years ago, the actual savings realized are still well below technical and economic potentials. The broad goal of this program is to develop and deploy a set of energy-saving technologies, strategies, and techniques, and improve processes for designing, commissioning, and operating commercial buildings, while improving health, comfort, and performance of occupants, all in a manner consistent with sound economic investment practices. Results are to be broadly applicable to the commercial sector for different building sizes and types, e.g. offices and schools, for different classes of ownership, both public and private, and for owner-occupied as well as speculative buildings. The program aims to facilitate significant electricity use savings in the California commercial sector by 2015, while assuring that these savings are affordable and promote high quality indoor environments. The five linked technical program elements contain 14 projects with 41 distinct R&D tasks. Collectively they form a comprehensive Research, Development, and Demonstration (RD&D) program with the potential to capture large savings in the commercial building sector, providing significant economic benefits to

  15. High Performance Computing in Science and Engineering '98 : Transactions of the High Performance Computing Center

    CERN Document Server

    Jäger, Willi

    1999-01-01

    The book contains reports about the most significant projects from science and industry that are using the supercomputers of the Federal High Performance Computing Center Stuttgart (HLRS). These projects are from different scientific disciplines, with a focus on engineering, physics and chemistry. They were carefully selected in a peer-review process and are showcases for an innovative combination of state-of-the-art physical modeling, novel algorithms and the use of leading-edge parallel computer technology. As HLRS is in close cooperation with industrial companies, special emphasis has been put on the industrial relevance of results and methods.

  16. High Performance Input/Output Systems for High Performance Computing and Four-Dimensional Data Assimilation

    Science.gov (United States)

    Fox, Geoffrey C.; Ou, Chao-Wei

    1997-01-01

    The approach of this task was to apply leading parallel computing research to a number of existing techniques for assimilation, and extract parameters indicating where and how input/output limits computational performance. The following was used for detailed knowledge of the application problems: 1. Developing a parallel input/output system specifically for this application 2. Extracting the important input/output characteristics of data assimilation problems; and 3. Building these characteristics s parameters into our runtime library (Fortran D/High Performance Fortran) for parallel input/output support.

  17. High Performance Computing in Science and Engineering '99 : Transactions of the High Performance Computing Center

    CERN Document Server

    Jäger, Willi

    2000-01-01

    The book contains reports about the most significant projects from science and engineering of the Federal High Performance Computing Center Stuttgart (HLRS). They were carefully selected in a peer-review process and are showcases of an innovative combination of state-of-the-art modeling, novel algorithms and the use of leading-edge parallel computer technology. The projects of HLRS are using supercomputer systems operated jointly by university and industry and therefore a special emphasis has been put on the industrial relevance of results and methods.

  18. Amorphous silicon based particle detectors

    OpenAIRE

    Wyrsch, N; Franco, A; Riesen, Y.; Despeisse, M; S. Dunand; Powolny, F; Jarron, P.; Ballif, C.

    2012-01-01

    Radiation hard monolithic particle sensors can be fabricated by a vertical integration of amorphous silicon particle sensors on top of CMOS readout chip. Two types of such particle sensors are presented here using either thick diodes or microchannel plates. The first type based on amorphous silicon diodes exhibits high spatial resolution due to the short lateral carrier collection. Combination of an amorphous silicon thick diode with microstrip detector geometries permits to achieve micromete...

  19. Development of high performance hybrid rocket fuels

    Science.gov (United States)

    Zaseck, Christopher R.

    In this document I discuss paraffin fuel combustion and investigate the effects of additives on paraffin entrainment and regression. In general, hybrid rockets offer an economical and safe alternative to standard liquid and solid rockets. However, slow polymeric fuel regression and low combustion efficiency have limited the commercial use of hybrid rockets. Paraffin is a fast burning fuel that has received significant attention in the 2000's and 2010's as a replacement for standard fuels. Paraffin regresses three to four times faster than polymeric fuels due to the entrainment of a surface melt layer. However, further regression rate enhancement over the base paraffin fuel is necessary for widespread hybrid rocket adoption. I use a small scale opposed flow burner to investigate the effect of additives on the combustion of paraffin. Standard additives such as aluminum combust above the flame zone where sufficient oxidizer levels are present. As a result no heat is generated below the flame itself. In small scale opposed burner experiments the effect of limited heat feedback is apparent. Aluminum in particular does not improve the regression of paraffin in the opposed burner. The lack of heat feedback from additive combustion limits the applicability of the opposed burner. In turn, the results obtained in the opposed burner with metal additive loaded hybrid fuels do not match results from hybrid rocket experiments. In addition, nano-scale aluminum increases melt layer viscosity and greatly slows the regression of paraffin in the opposed flow burner. However, the reactive additives improve the regression rate of paraffin in the opposed burner where standard metals do not. At 5 wt.% mechanically activated titanium and carbon (Ti-C) improves the regression rate of paraffin by 47% in the opposed burner. The mechanically activated Ti C likely reacts in or near the melt layer and provides heat feedback below the flame region that results in faster opposed burner regression

  20. Superconducting Metallic Glass Transition-Edge-Sensors

    Science.gov (United States)

    Hays, Charles C. (Inventor)

    2013-01-01

    A superconducting metallic glass transition-edge sensor (MGTES) and a method for fabricating the MGTES are provided. A single-layer superconducting amorphous metal alloy is deposited on a substrate. The single-layer superconducting amorphous metal alloy is an absorber for the MGTES and is electrically connected to a circuit configured for readout and biasing to sense electromagnetic radiation.

  1. Interface engineering for high performance graphene electronic devices

    Science.gov (United States)

    Jung, Dae Yool; Yang, Sang Yoon; Park, Hamin; Shin, Woo Cheol; Oh, Joong Gun; Cho, Byung Jin; Choi, Sung-Yool

    2015-06-01

    A decade after the discovery of graphene flakes, exfoliated from graphite, we have now secured large scale and high quality graphene film growth technology via a chemical vapor deposition (CVD) method. With the establishment of mass production of graphene using CVD, practical applications of graphene to electronic devices have gained an enormous amount of attention. However, several issues arise from the interfaces of graphene systems, such as damage/unintentional doping of graphene by the transfer process, the substrate effects on graphene, and poor dielectric formation on graphene due to its inert features, which result in degradation of both electrical performance and reliability in actual devices. The present paper provides a comprehensive review of the recent approaches to resolve these issues by interface engineering of graphene for high performance electronic devices. We deal with each interface that is encountered during the fabrication steps of graphene devices, from the graphene/metal growth substrate to graphene/high-k dielectrics, including the intermediate graphene/target substrate.

  2. Hybrid nanostructured materials for high-performance electrochemical capacitors

    KAUST Repository

    Yu, Guihua

    2013-03-01

    The exciting development of advanced nanostructured materials has driven the rapid growth of research in the field of electrochemical energy storage (EES) systems which are critical to a variety of applications ranging from portable consumer electronics, hybrid electric vehicles, to large industrial scale power and energy management. Owing to their capability to deliver high power performance and extremely long cycle life, electrochemical capacitors (ECs), one of the key EES systems, have attracted increasing attention in the recent years since they can complement or even replace batteries in the energy storage field, especially when high power delivery or uptake is needed. This review article describes the most recent progress in the development of nanostructured electrode materials for EC technology, with a particular focus on hybrid nanostructured materials that combine carbon based materials with pseudocapacitive metal oxides or conducting polymers for achieving high-performance ECs. This review starts with an overview of EES technologies and the comparison between various EES systems, followed by a brief description of energy storage mechanisms for different types of EC materials. This review emphasizes the exciting development of both hybrid nanomaterials and novel support structures for effective electrochemical utilization and high mass loading of active electrode materials, both of which have brought the energy density of ECs closer to that of batteries while still maintaining their characteristic high power density. Last, future research directions and the remaining challenges toward the rational design and synthesis of hybrid nanostructured electrode materials for next-generation ECs are discussed. © 2012 Elsevier Ltd.

  3. High Performance Computing in Science and Engineering '02 : Transactions of the High Performance Computing Center

    CERN Document Server

    Jäger, Willi

    2003-01-01

    This book presents the state-of-the-art in modeling and simulation on supercomputers. Leading German research groups present their results achieved on high-end systems of the High Performance Computing Center Stuttgart (HLRS) for the year 2002. Reports cover all fields of supercomputing simulation ranging from computational fluid dynamics to computer science. Special emphasis is given to industrially relevant applications. Moreover, by presenting results for both vector sytems and micro-processor based systems the book allows to compare performance levels and usability of a variety of supercomputer architectures. It therefore becomes an indispensable guidebook to assess the impact of the Japanese Earth Simulator project on supercomputing in the years to come.

  4. Implant- and Tooth-Supported Fixed Prostheses Using a High-Performance Polymer (Pekkton) Framework.

    Science.gov (United States)

    Han, Kyeong-Hwan; Lee, Jeong-Yol; Shin, Sang Wan

    2016-01-01

    The type of prosthetic restoration used in implant rehabilitation greatly contributes to the recovery of masticatory function as well as quality of life in patients. Frameworks for implant-supported prostheses are typically made by casting metal or milling either titanium or zirconia. Recently, nonmetal, polymer-type materials were suggested as framework materials. Polyetherketoneketone (PEKK), a high-performance polymer, was recently introduced in the dental field with potentially wide-ranging applications. This case history report describes implant- and tooth-supported fixed prostheses created using a new high performance polymer (Pekkton, Cendres+Metaux) framework for a fully edentulous maxilla and partially edentulous mandible. PMID:27611747

  5. Unexpected magnetic behavior in amorphous Co90Sc10 alloy

    International Nuclear Information System (INIS)

    An amorphous alloy Co90Sc10 has been prepared by rapid quenching from the melt. The results of magnetization measurements show that this alloy has the highest Curie temperature reported for any amorphous transition metal based alloys. Furthermore, for a Co based amorphous alloy, the magnetic moment is remarkably high. Moreover, the alloy exhibits soft magnetic properties. Based on the findings, amorphous Co90Sc10 appears to be an attractive candidate for applications as a soft magnetic material. The temperature dependence of the reduced magnetization can be described by the Bloch power law. The results show that the B coefficient of the amorphous Co90Sc10 alloy, which is a measure of the rigidity of spin waves, exhibits the lowest value observed until now for any amorphous alloy and is comparable to crystalline alloys. It is found that the Sc atoms in the Co90Sc10 alloy lead to an increase of the itinerant spin moment of Co atoms, and, in contrast to this behaviour, to a decrease of the local 3d-electrons of Co

  6. Unexpected magnetic behavior in amorphous Co90Sc10 alloy

    Science.gov (United States)

    Ghafari, M.; Sakurai, Y.; Peng, G.; Fang, Y. N.; Feng, T.; Hahn, H.; Gleiter, H.; Itou, M.; Kamali, S.

    2015-09-01

    An amorphous alloy Co90Sc10 has been prepared by rapid quenching from the melt. The results of magnetization measurements show that this alloy has the highest Curie temperature reported for any amorphous transition metal based alloys. Furthermore, for a Co based amorphous alloy, the magnetic moment is remarkably high. Moreover, the alloy exhibits soft magnetic properties. Based on the findings, amorphous Co90Sc10 appears to be an attractive candidate for applications as a soft magnetic material. The temperature dependence of the reduced magnetization can be described by the Bloch power law. The results show that the B coefficient of the amorphous Co90Sc10 alloy, which is a measure of the rigidity of spin waves, exhibits the lowest value observed until now for any amorphous alloy and is comparable to crystalline alloys. It is found that the Sc atoms in the Co90Sc10 alloy lead to an increase of the itinerant spin moment of Co atoms, and, in contrast to this behaviour, to a decrease of the local 3d-electrons of Co.

  7. Selective alkane activation with single-site atoms on amorphous support

    Science.gov (United States)

    Hock, Adam S.; Schweitzer, Neil M.; Miller, Jeffrey T.; Hu, Bo

    2015-11-24

    The present invention relates generally to catalysts and methods for use in olefin production. More particularly, the present invention relates to novel amorphously supported single-center, Lewis acid metal ions and use of the same as catalysts.

  8. Reaction of amorphous Ni-W and Ni-N-W films with substrate silicon

    Science.gov (United States)

    Zhu, M. F.; Suni, I.; Nicolet, M.-A.; Sands, T.

    1984-01-01

    Wiley et al. (1982) have studied sputtered amorphous films of Nb-Ni, Mo-Ni, Si-W, and Si-Mo. Kung et al. (1984) have found that amorphous Ni-Mo films as diffusion barriers between multilayer metallizations on silicon demonstrate good electrical and thermal stability. In the present investigation, the Ni-W system was selected because it is similar to the Ni-Mo system. However, W has a higher silicide formation temperature than Mo. Attention is given to aspects of sample preparation, sample characterization, the interaction between amorphous Ni-W films and Si, the crystallization of amorphous Ni(36)W(64) films on SiO2, amorphous Ni-N-W films, silicide formation and phase separation, and the crystallization of amorphous Ni(36)W(64) and Ni(30)N(21)W(49) layers.

  9. DOE research in utilization of high-performance computers

    International Nuclear Information System (INIS)

    Department of Energy (DOE) and other Government research laboratories depend on high-performance computer systems to accomplish their programatic goals. As the most powerful computer systems become available, they are acquired by these laboratories so that advances can be made in their disciplines. These advances are often the result of added sophistication to numerical models whose execution is made possible by high-performance computer systems. However, high-performance computer systems have become increasingly complex; consequently, it has become increasingly difficult to realize their potential performance. The result is a need for research on issues related to the utilization of these systems. This report gives a brief description of high-performance computers, and then addresses the use of and future needs for high-performance computers within DOE, the growing complexity of applications within DOE, and areas of high-performance computer systems warranting research. 1 figure

  10. Welding of cobalt-based amorphous alloys with Nd: YAG laser

    International Nuclear Information System (INIS)

    The paper describes the results concerning the investigation of the welding of cobalt-based amorphous alloys with Nd:YAG laser. Five alloys with different chemical structure and dimensions in shape of amorphous metal foils were welded. The quality of the welded joints were tested by using a microstructure analysis with an optical microscope and SEM, when the metal graphic structure, the chemical structure and the microhardness of the welded joints were tested as well. (Author)

  11. An amorphous phase formation at palladium / silicon oxide (Pd/SiOx) interface through electron irradiation - electronic excitation process

    International Nuclear Information System (INIS)

    A Pd-Si amorphous phase was formed at a palladium/silicon oxide (Pd/SiOx) interface at room temperature by electron irradiation at acceleration voltages ranging between 25 kV and 200 kV. Solid-state amorphization was stimulated without the electron knock-on effects. The total dose required for the solid-state amorphization decreases with decreasing acceleration voltage. This is the first report on electron irradiation induced metallic amorphous formation caused by the electronic excitation at metal/silicon oxide interface

  12. Innovative Deep Throttling, High Performance Injector Concept Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Science and Technology Applications, LLC's (STA) vision for a versatile space propulsion system is a highly throttleable, high performance, and cost effective...

  13. High Performance Monopropellants for Future Planetary Ascent Vehicles Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Physical Sciences Inc. proposes to design, develop, and demonstrate, a novel high performance monopropellant for application in future planetary ascent vehicles....

  14. Transportation properties of amorphous state InSb and its metastable middle phase

    International Nuclear Information System (INIS)

    The variation of the substrate temperature induces the metal-semiconductor transition in the condensation InSb films at low temperatrue. The electron conduction is dominant in the metal-type amorphous InSb and the hole in semiconductor-type one. In the metal-type amorphous InSb the electron-electron is correlated under the field above 0.1T in the temperature region of liquid nitrogen. The structure relaxation leads to not only the increase of the short range order but also the change of electron structure in metal-type amorphous InSb. The first conductance jump originates mainly from the increase of Hall mobility of the carrier, i.e. the increase of the short range order, and the system relaxes from the liquid-like to the lattice-like amorphous state. The three types of the crystallization phase transition for the metal-type amorphous InSb present obviously different transportation behaviours. Both metal-type amorphous state and metastable middle phase of InSb all are one of superconducting system with the lowest carrier concentration (n0∼1018 cm-3). Superconducting Tc of the metastable middle phase is related to the state density near Fermi surface, i.e. the higher Tc corresponds to the higher state density. The quasi-two-dimensional structure is favourable to superconductivity

  15. High Performance Computing in Science and Engineering '08 : Transactions of the High Performance Computing Center

    CERN Document Server

    Kröner, Dietmar; Resch, Michael

    2009-01-01

    The discussions and plans on all scienti?c, advisory, and political levels to realize an even larger “European Supercomputer” in Germany, where the hardware costs alone will be hundreds of millions Euro – much more than in the past – are getting closer to realization. As part of the strategy, the three national supercomputing centres HLRS (Stuttgart), NIC/JSC (Julic ¨ h) and LRZ (Munich) have formed the Gauss Centre for Supercomputing (GCS) as a new virtual organization enabled by an agreement between the Federal Ministry of Education and Research (BMBF) and the state ministries for research of Baden-Wurttem ¨ berg, Bayern, and Nordrhein-Westfalen. Already today, the GCS provides the most powerful high-performance computing - frastructure in Europe. Through GCS, HLRS participates in the European project PRACE (Partnership for Advances Computing in Europe) and - tends its reach to all European member countries. These activities aligns well with the activities of HLRS in the European HPC infrastructur...

  16. Quantification of corrosion resistance of a new-class of criticality control materials: thermal-spray coatings of high-boron iron-based amorphous metals - Fe49.7Cr17.7Mn1.9Mo7.4W1.6B15.2C3.8Si2.4

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J C; Choi, J S; Shaw, C K; Rebak, R; Day, S D; Lian, T; Hailey, P; Payer, J H; Branagan, D J; Aprigliano, L F

    2007-03-28

    An iron-based amorphous metal, Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4} (SAM2X5), with very good corrosion resistance was developed. This material was produced as a melt-spun ribbon, as well as gas atomized powder and a thermal-spray coating. Chromium (Cr), molybdenum (Mo) and tungsten (W) provided corrosion resistance, and boron (B) enabled glass formation. The high boron content of this particular amorphous metal made it an effective neutron absorber, and suitable for criticality control applications. Earlier studies have shown that ingots and melt-spun ribbons of these materials have good passive film stability in these environments. Thermal spray coatings of these materials have now been produced, and have undergone a variety of corrosion testing, including both atmospheric and long-term immersion testing. The modes and rates of corrosion have been determined in the various environments, and are reported here.

  17. Avaliação das propriedades mecânicas de juntas cerâmicas usando fitas amorfas como metal de adição Evaluation of the mechanical properties of ceramic joint using amorphous ribbons as filler metals

    Directory of Open Access Journals (Sweden)

    Danielton Gomes dos Santos

    2009-09-01

    Full Text Available Este trabalho teve como objetivo determinar os melhores parâmetros para brasagem de juntas cerâmicas de Al2O3 pré-metalizadas com Ti por processo a plasma utilizando fitas amorfas de ligas Cu49Ag45Cx e como metal de adição. As ligas foram preparadas em forno a arco, e, posteriormente processadas por melt-spinning, variando conteúdo Ce de 4-6. %. A brasagem foi realizada em forno à vácuo e as seguintes variáveis analisadas: tempo de deposição do filme de Ti e temperatura e tempo de brasagem , que foram relacionados com a resistência à flexão em 3 pontos da junta brazada. A equação de regressão linear foi obtida, e verificou-se a interação entre estes fatores. As superfícies cerâmicas metalizadas apresentaram excelente uniformidade e as juntas brasadas muito boa adesão atingindo valores de resistência à flexão de até 176,8 MPa.This work had as objective to establish de best brazing parameter to joint Al2O3 pre-metalized with Ti by plasma process using amorphous ribbons of Cu49g45Ce x alloys as filler metals. The alloys were prepared in arc furnace and processed by melt-spinning process varying the Ce percentiles from 4 to 6. % . The brazing was accomplished in vacuum furnace and the following variables analyzed: deposition time of Ti film, brazing temperature and brazing times which were related to the brazed joint 3-point bending resistance. The interaction between those factors was obtained by linear regression equation. The metalized ceramic surfaces presented an good uniformity and the joint a very good adhesion reaching bending resistance up to 176,8 MPa.

  18. The interface structure of high performance ZnO Schottky diodes

    International Nuclear Information System (INIS)

    Oxidized iridium (IrOx) anodes fabricated on n-type ZnO single crystal wafers using reactive pulsed laser deposition are known to produce high quality Schottky barriers with ideality factors approaching the image-force-controlled limit for laterally homogeneous interfaces. These high performance IrOx/ZnO Schottky contacts were cross-sectioned and analyzed using transmission electron microscopy, revealing an amorphous interfacial layer of 2-3 nm thickness. Electron energy loss spectroscopy, used to study the composition of the interface region, showed evidence of significant zinc diffusion across the interface into the IrOx film, which leads to the creation of Zn vacancies (acceptors), in the ZnO sub-interface region. There is also evidence for oxygen passivation near the interface resulting from the use of an active oxygen ambient during the IrOx deposition. Both these factors may explain the outstanding electrical performance of these Schottky devices.

  19. High performance nanophotonic circuits based on partially buried horizontal slot waveguides

    CERN Document Server

    Xiong, Chi; Li, Mo; Tang, Hong X

    2014-01-01

    We present a novel platform to construct high-performance nanophotonic devices in low refractive index dielectric films at telecoms wavelengths. The formation of horizontal slots by PECVD deposition of high index amorphous silicon provides a convenient and low-cost way to tailor nanophotonic devices to application needs. Low propagation loss of less than 2 dB/cm is obtained allowing us to fabricate optical resonators with measured high optical quality factors exceeding 10^5. We design and experimentally demonstrate on-chip grating couplers to efficiently couple light into integrated circuitry with coupling loss of 4 dB and optical bandwidth exceeding 110 nm. The entire on-chip circuitry consisting of input/output couplers, Mach-Zehnder interferometers with high extinction ratio and ring, racetrack resonators are designed, fabricated and characterized.

  20. High-performance ferroelectric memory based on phase-separated films of polymer blends

    KAUST Repository

    Khan, Mohammad A.

    2013-10-29

    High-performance polymer memory is fabricated using blends of ferroelectric poly(vinylidene-fluoride-trifluoroethylene) (P(VDF-TrFE)) and highly insulating poly(p-phenylene oxide) (PPO). The blend films spontaneously phase separate into amorphous PPO nanospheres embedded in a semicrystalline P(VDF-TrFE) matrix. Using low molecular weight PPO with high miscibility in a common solvent, i.e., methyl ethyl ketone, blend films are spin cast with extremely low roughness (Rrms ≈ 4.92 nm) and achieve nanoscale phase seperation (PPO domain size < 200 nm). These blend devices display highly improved ferroelectric and dielectric performance with low dielectric losses (<0.2 up to 1 MHz), enhanced thermal stability (up to ≈353 K), excellent fatigue endurance (80% retention after 106 cycles at 1 KHz) and high dielectric breakdown fields (≈360 MV/m). © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Hydrogenated amorphous silicon deposited by ion-beam sputtering

    Science.gov (United States)

    Lowe, V. E.; Henin, N.; Tu, C.-W.; Tavakolian, H.; Sites, J. R.

    1981-01-01

    Hydrogenated amorphous silicon films 1/2 to 1 micron thick were deposited on metal and glass substrates using ion-beam sputtering techniques. The 800 eV, 2 mA/sq cm beam was a mixture of argon and hydrogen ions. The argon sputtered silicon from a pure (7.6 cm) single crystal wafer, while the hydrogen combined with the sputtered material during the deposition. Hydrogen to argon pressure ratios and substrate temperatures were varied to minimize the defect state density in the amorphous silicon. Characterization was done by electrical resistivity, index of refraction and optical absorption of the films.

  2. High performance transistors via aligned polyfluorene-sorted carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Brady, Gerald J.; Joo, Yongho; Singha Roy, Susmit; Gopalan, Padma; Arnold, Michael S., E-mail: msarnold@wisc.edu [Department of Materials Science and Engineering, University of Wisconsin-Madison, 1509 University Avenue, Madison, Wisconsin 53706 (United States)

    2014-02-24

    We evaluate the performance of exceptionally electronic-type sorted, semiconducting, aligned single-walled carbon nanotubes (s-SWCNTs) in field effect transistors (FETs). High on-conductance and high on/off conductance modulation are simultaneously achieved at channel lengths which are both shorter and longer than individual s-SWCNTs. The s-SWCNTs are isolated from heterogeneous mixtures using a polyfluorene-derivative as a selective agent and aligned on substrates via dose-controlled, floating evaporative self-assembly at densities of ∼50 s-SWCNTs μm{sup −1}. At a channel length of 9 μm the s-SWCNTs percolate to span the FET channel, and the on/off ratio and charge transport mobility are 2.2 × 10{sup 7} and 46 cm{sup 2} V{sup −1} s{sup −1}, respectively. At a channel length of 400 nm, a large fraction of the s-SWCNTs directly span the channel, and the on-conductance per width is 61 μS μm{sup −1} and the on/off ratio is 4 × 10{sup 5}. These results are considerably better than previous solution-processed FETs, which have suffered from poor on/off ratio due to spurious metallic nanotubes that bridge the channel. 4071 individual and small bundles of s-SWCNTs are tested in 400 nm channel length FETs, and all show semiconducting behavior, demonstrating the high fidelity of polyfluorenes as selective agents and the promise of assembling s-SWCNTs from solution to create high performance semiconductor electronic devices.

  3. Microfabricated electrochemical detector for high-performance liquid chromatography.

    Science.gov (United States)

    Ogburn, Evan T; Dziewatkoski, Michael; Moles, Don; Johnson, Jay M; Heineman, William R

    2011-09-15

    A microfabricated electrochemical cell has been developed as a disposable detector for flow injection analysis (FIA) and high-performance liquid chromatography (HPLC). The simplicity of the fabrication process allows this detector to be used as a low-cost, disposable device that can be replaced easily if its performance degrades rather than disassembling the detector and polishing the electrode surface, which is the usual procedure. The detector consists of thin film-metal electrodes-platinum working electrode, platinum auxiliary electrode, and silver/silver chloride coated on Pt reference electrode-deposited on a polyimide substrate with a locking layer of chromium in between. A microfluidic cover made of polyimide directs the solution flow across the electrodes. The detector was evaluated with FIA of ferrocyanide and HPLC of ascorbic acid and acetaminophen and a mixture of two pharmaceutical compounds-dextrorphan and levallorphan-with acetaminophen internal standard. The HPLC calibration curves showed good linearity (R(2) > 0.99). Limits of detection were 1 nM for acetaminophen, 1 nM for ascorbic acid, 50 nM for dextrorphan, and 80 nM for levallorphan. When detected with a commercial detector dextrorphan and levallorphan had lower limits of detection, 3 and 5 nM, respectively. Chromatograms of the mixture were comparable to those obtained with a commercial detector. The detector could be used continuously for about 48 h with FIA and about 10-20 h with HPLC after which performance gradually degraded as the AgCl on the reference electrode dissolved causing loss of potential control. PMID:21598939

  4. Building Synergy: The Power of High Performance Work Systems.

    Science.gov (United States)

    Gephart, Martha A.; Van Buren, Mark E.

    1996-01-01

    Suggests that high-performance work systems create the synergy that lets companies gain and keep a competitive advantage. Identifies the components of high-performance work systems and critical action steps for implementation. Describes the results companies such as Xerox, Lever Brothers, and Corning Incorporated have achieved by using them. (JOW)

  5. Simulation in Amorphous Silicon and Amorphous Silicon Carbide Pin Diodes

    OpenAIRE

    Gonçalves, Dora; Fernandes, Miguel; Louro, Paula; Fantoni, Alessandro; Vieira, Manuela

    2014-01-01

    Part 21: Electronics: Devices International audience Photodiodes are devices used as image sensors, reactive to polychromatic light and subsequently color detecting, and they are also used in optical communication applications. To improve these devices performance it is essential to study and control their characteristics, in fact their capacitance and spectral and transient responses. This study considers two types of diodes, an amorphous silicon pin and an amorphous silicon carbide pi...

  6. High-Performance Acousto-Ultrasonic Scan System Being Developed

    Science.gov (United States)

    Roth, Don J.; Martin, Richard E.; Cosgriff, Laura M.; Gyekenyesi, Andrew L.; Kautz, Harold E.

    2003-01-01

    Acousto-ultrasonic (AU) interrogation is a single-sided nondestructive evaluation (NDE) technique employing separated sending and receiving transducers. It is used for assessing the microstructural condition and distributed damage state of the material between the transducers. AU is complementary to more traditional NDE methods, such as ultrasonic cscan, x-ray radiography, and thermographic inspection, which tend to be used primarily for discrete flaw detection. Throughout its history, AU has been used to inspect polymer matrix composites, metal matrix composites, ceramic matrix composites, and even monolithic metallic materials. The development of a high-performance automated AU scan system for characterizing within-sample microstructural and property homogeneity is currently in a prototype stage at NASA. This year, essential AU technology was reviewed. In addition, the basic hardware and software configuration for the scanner was developed, and preliminary results with the system were described. Mechanical and environmental loads applied to composite materials can cause distributed damage (as well as discrete defects) that plays a significant role in the degradation of physical properties. Such damage includes fiber/matrix debonding (interface failure), matrix microcracking, and fiber fracture and buckling. Investigations at the NASA Glenn Research Center have shown that traditional NDE scan inspection methods such as ultrasonic c-scan, x-ray imaging, and thermographic imaging tend to be more suited to discrete defect detection rather than the characterization of accumulated distributed microdamage in composites. Since AU is focused on assessing the distributed microdamage state of the material in between the sending and receiving transducers, it has proven to be quite suitable for assessing the relative composite material state. One major success story at Glenn with AU measurements has been the correlation between the ultrasonic decay rate obtained during AU

  7. High Performance AlGaN Metal-Semiconductor-Metal Ultraviolet Photo Detectors.

    OpenAIRE

    S. Benzeghda; Hobar, F.; Decoster, D.

    2013-01-01

    In this paper, we present Al0.25Ga0.75N ultraviolet Schottky barrier photodetectors on Al2O3, that was modeled using The two-dimensional device simulator Silvaco and ATLAS. It was found that the device has very low dark current, with the applied bias below 1 V, the dark current was below 16 pA and the peak responsivity of 0.07A/W was achieved at 308nm. We have performed a comparison between our modeling and the experimental results

  8. Amorphous diffusion bonding of steel pipe and its impact toughness

    Institute of Scientific and Technical Information of China (English)

    WANG Xuegang; YAN Fengjie; YAN Qian; LI Xingeng

    2007-01-01

    An iron-based amorphous foil (FeNiCrSiB) was used as an interlayer for the amorphous diffusion bonding of low carbon steel pipes under argon flux. The microstructure and mechanical properties of the joint were analyzed using an electron probe micro-analyzer (EPMA), tensile test, bending test and impact test. The results show that the joint micro-structure resembles that of the base metal and no precipitates form at the joint. Melting point depressants 03, Si) diffuse far away from the joint and the base metal element is homoge-nous across the joint. The joint impact toughness is greater than the base metal toughness and the mechanical properties of the joint are similar around the pipe.

  9. Chemical Compatibility of High-Performance Engineering Thermoplastics in Compressor Environments

    OpenAIRE

    Pai-Paranjape, Vandita

    2014-01-01

    The compressor industry faces a difficult design environment for achieving performance improvement, reduced cost, and lower environmental footprint. In order to address some of these challenges, thermoplastics can be considered as a replacement for metal in some compressor parts. Thermoplastics have been found to be suitable for steel replacement in structural parts for automotive and brass replacement in water-handling applications such as meters. As such, we believe certain high-performance...

  10. High performance 1.3 μm InGaAsN superluminescent diodes

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    High performance 1.3 μm InGaAsN superluminescent diodes (SLDs) were fabricated with Schottky contact. The structure was grown by metal organic chemical vapor deposition (MOCVD). Output power of 3 mW was obtained in continuous wave (CW) mode at room temperature. The full width at half maximum (FWHM) of the emission spectrum was 30 nm. The devices operated up to 100℃.

  11. High performance 1.3 μm InGaAsN superluminescent diodes

    Institute of Scientific and Technical Information of China (English)

    QU Yi; LI Hui; J.X.Zhang; BO BaoXue; GAO Xin; LIU GuoJun

    2009-01-01

    High performance 1.3 μm InGaAsN superluminescent diodes(SLDs)were fabricated with Schottkycontact.The structure was grown by metal organic chemical vapor deposition(MOCVD).Output power of 3 mW was obtained in continuous wave(CW)mode at room temperature.The full width at half maximum(FWHM)of the emission spectrum was 30 nm.The devices operated up to 100℃.

  12. Amorphous photonic membranes for broadband chemical sensing applications

    Science.gov (United States)

    Abbey, Sonja P.; Whaley, Ralph D., Jr.

    2012-01-01

    While there has been extensive development on integrated sensors in the near-IR region due to the maturation of Si, SOI, and III-V materials, these technologies are not easily translated into the visible and near-UV regions which are critical for the detection of many chemicals of environmental and security interest. This work focuses on the use of wide bandgap, amorphous materials, specifically, amorphous zinc oxide (a-ZnO), amorphous hafnium oxide (a-HfO2) and amorphous beryllium zinc oxide (a-BeZnO), in the development of broadband chemical sensors operating at critical absorption lines spanning the near-UV (200 nm) to the near-IR (1.55 μm). The architecture employed for this research is a nanoscale membrane (typically 40 - 100 nm thick) that supports a guided low optical overlap mode (LOOM) - an optical mode in which approximately 1% of the electric field is confined to the lossy core region. The resulting extended mode has a greatly enhanced analyte overlap, yielding a device sensitivity (~70%) that is over an order of magnitude higher than current high-performance, dielectric evanescent wave sensors (~2%) as modeled by analytical and finite element methods. Due to the extended nature of the LOOM, sensing across the entire spectral range can be achieved with a single waveguide design - critical for multi-point chemical sensing architectures.

  13. Results from multipoint alignment monitoring using the new generation of amorphous silicon position detectors

    Energy Technology Data Exchange (ETDEWEB)

    Alberdi, J.; Arce, P.; Barcala, J.M.; Calvo, E. [CIEMAT, 28040 Madrid (Spain); Ferrando, A. [CIEMAT, 28040 Madrid (Spain)], E-mail: antonio.ferrando@ciemat.es; Josa, M.I.; Molinero, A.; Navarrete, J.; Oller, J.C.; Yuste, C. [CIEMAT, 28040 Madrid (Spain); Calderon, A.; Gomez, G.; Gonzalez-Sanchez, F.J.; Martinez-Rivero, C.; Matorras, F.; Rodrigo, T.; Ruiz-Arbol, P.; Sobron, M.; Vila, I.; Virto, A.L. [Instituto de Fisica de Cantabria (IFCA), CSIC-University of Cantabria Santander (Spain)] (and others)

    2008-08-11

    We present the measured performance of a new generation of large sensitive area (28x28 mm{sup 2}) semitransparent amorphous silicon position detector sensors. More than 100 units have been characterized. They show a very high performance. To illustrate a multipoint application, we present results from the monitoring of five sensors placed in a 5.5-m-long light path.

  14. Construction process and read-out electronics of amorphous silicon position detectors for multipoint alignment monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, C.; Schubert, M.B.; Lutz, B.; Werner, J.H. [Steinbeis-Transferzentrum fuer Angewandte Photovoltaik und Duennschichttechnik, Stuttgart (Germany); Alberdi, J.; Arce, P.; Barcala, J.M.; Calvo, E. [CIEMAT, Madrid (Spain); Ferrando, A. [CIEMAT, Madrid (Spain)], E-mail: antonio.ferrando@ciemat.es; Josa, M.I.; Molinero, A.; Navarrete, J.; Oller, J.C.; Yuste, C. [CIEMAT, Madrid (Spain); Calderon, A.; Fernandez, M.G.; Gomez, G.; Gonzalez-Sanchez, F.J.; Martinez-Rivero, C.; Matorras, F. [Instituto de Fisica de Cantabria IFCA/CSIC-University of Cantabria, Santander (Spain)] (and others)

    2009-09-01

    We describe the construction process of large-area high-performance transparent amorphous silicon position detecting sensors. Details about the characteristics of the associated local electronic board (LEB), specially designed for these sensors, are given. In addition we report on the performance of a multipoint alignment monitoring application of 12 sensors in a 13 m long light path.

  15. Amorphous drugs and dosage forms

    DEFF Research Database (Denmark)

    Grohganz, Holger; Löbmann, K.; Priemel, P.;

    2013-01-01

    The transformation to an amorphous form is one of the most promising approaches to address the low solubility of drug compounds, the latter being an increasing challenge in the development of new drug candidates. However, amorphous forms are high energy solids and tend to recry stallize. New...... formulation principles are needed to ensure the stability of amorphous drug forms. The formation of solid dispersions is still the most investigated approach, but additional approaches are desirable to overcome the shortcomings of solid dispersions. Spatial separation by either coating or the use of micro......-containers has shown potential to prevent or delay recrystallization. Another recent approach is the formation of co-amorphous mixtures between either two drugs or one drug and one low molecular weight excipient. Molecular interactions between the two molecules provide an energy barrier that has to be overcome...

  16. Novel nano materials for high performance logic and memory devices

    Science.gov (United States)

    Das, Saptarshi

    After decades of relentless progress, the silicon CMOS industry is approaching a stall in device performance for both logic and memory devices due to fundamental scaling limitations. In order to reinforce the accelerating pace, novel materials with unique properties are being proposed on an urgent basis. This list includes one dimensional nanotubes, quasi one dimensional nanowires, two dimensional atomistically thin layered materials like graphene, hexagonal boron nitride and the more recently the rich family of transition metal di-chalcogenides comprising of MoS2, WSe2, WS2 and many more for logic applications and organic and inorganic ferroelectrics, phase change materials and magnetic materials for memory applications. Only time will tell who will win, but exploring these novel materials allow us to revisit the fundamentals and strengthen our understanding which will ultimately be beneficial for high performance device design. While there has been growing interest in two-dimensional (2D) crystals other than graphene, evaluating their potential usefulness for electronic applications is still in its infancies due to the lack of a complete picture of their performance potential. The fact that the 2-D layered semiconducting di-chalcogenides need to be connected to the "outside" world in order to capitalize on their ultimate potential immediately emphasizes the importance of a thorough understanding of the contacts. This thesis demonstrate that through a proper understanding and design of source/drain contacts and the right choice of number of MoS2 layers the excellent intrinsic properties of this 2D material can be harvested. A comprehensive experimental study on the dependence of carrier mobility on the layer thickness of back gated multilayer MoS 2 field effect transistors is also provided. A resistor network model that comprises of Thomas-Fermi charge screening and interlayer coupling is used to explain the non-monotonic trend in the extracted field effect

  17. Novel high performance multispectral photodetector and its performance

    Science.gov (United States)

    Mizuno, Genki; Dutta, Jaydeep; Oduor, Patrick; Dutta, Achyut K.; Dhar, Nibir K.

    2016-05-01

    Banpil Photonics has developed a novel high-performance multispectral photodetector array for Short-Wave Infrared (SWIR) imaging. The InGaAs based device uses a unique micro-nano pillar structure that eliminates surface reflection to significantly increase sensitivity and the absorption spectra compared to its macro-scaled thin film pixels counterpart (non-pillar). We discuss the device structure and highlight fabrication of the novel high performance multispectral image sensor. We also present performance results of the device characterization showing low dark current suitable for high performance imaging applications for the most demanding security, defense, and machine vision applications.

  18. Amorphous silicon based large format uncooled FPA microbolometer technology

    Science.gov (United States)

    Schimert, T.; Brady, J.; Fagan, T.; Taylor, M.; McCardel, W.; Gooch, R.; Ajmera, S.; Hanson, C.; Syllaios, A. J.

    2008-04-01

    This paper presents recent developments in next generation microbolometer Focal Plane Array (FPA) technology at L-3 Communications Infrared Products (L-3 CIP). Infrared detector technology at L-3 CIP is based on hydrogenated amorphous silicon (a-Si:H) and amorphous silicon germanium(a-SiGe:H). Large format high performance, fast, and compact IR FPAs are enabled by a low thermal mass pixel design; favorable material properties; an advanced ROIC design; and wafer level packaging. Currently at L-3 CIP, 17 micron pixel FPA array technology including 320x240, 640 x 480 and 1024 x768 arrays is under development. Applications of these FPAs range from low power microsensors to high resolution near-megapixel imager systems.

  19. Amorphous carbon for photovoltaics

    Science.gov (United States)

    Risplendi, Francesca; Grossman, Jeffrey C.

    2015-03-01

    All-carbon solar cells have attracted attention as candidates for innovative photovoltaic devices. Carbon-based materials such as graphene, carbon nanotubes (CNT) and amorphous carbon (aC) have the potential to present physical properties comparable to those of silicon-based materials with advantages such as low cost and higher thermal stability.In particular a-C structures are promising systems in which both sp2 and sp3 hybridization coordination are present in different proportions depending on the specific density, providing the possibility of tuning their optoelectronic properties and achieving comparable sunlight absorption to aSi. In this work we employ density functional theory to design suitable device architectures, such as bulk heterojunctions (BHJ) or pn junctions, consisting of a-C as the active layer material.Regarding BHJ, we study interfaces between aC and C nanostructures (such as CNT and fullerene) to relate their optoelectronic properties to the stoichiometry of aC. We demonstrate that the energy alignment between the a-C mobility edges and the occupied and unoccupied states of the CNT or C60 can be widely tuned by varying the aC density to obtain a type II interface.To employ aC in pn junctions we analyze the p- and n-type doping of a-C focusingon an evaluation of the Fermi level and work function dependence on doping.Our results highlight promising features of aC as the active layer material of thin-film solar cells.

  20. High Performance Low Mass Nanowire Enabled Heatpipe Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Heat pipes are widely used for passive, two-phase electronics cooling. As advanced high power, high performance electronics in space based and terrestrial...

  1. Energy Design Guidelines for High Performance Schools: Tropical Island Climates

    Energy Technology Data Exchange (ETDEWEB)

    None

    2004-11-01

    Design guidelines outline high performance principles for the new or retrofit design of K-12 schools in tropical island climates. By incorporating energy improvements into construction or renovation plans, schools can reduce energy consumption and costs.

  2. High Performance Low Mass Nanowire Enabled Heatpipe Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Illuminex Corporation proposes a NASA Phase I SBIR project to develop high performance, lightweight, low-profile heat pipes with enhanced thermal transfer...

  3. Highlighting High Performance: Whitman Hanson Regional High School; Whitman, Massachusetts

    Energy Technology Data Exchange (ETDEWEB)

    2006-06-01

    This brochure describes the key high-performance building features of the Whitman-Hanson Regional High School. The brochure was paid for by the Massachusetts Technology Collaborative as part of their Green Schools Initiative. High-performance features described are daylighting and energy-efficient lighting, indoor air quality, solar and wind energy, building envelope, heating and cooling systems, water conservation, and acoustics. Energy cost savings are also discussed.

  4. Variational formulation of high performance finite elements: Parametrized variational principles

    Science.gov (United States)

    Felippa, Carlos A.; Militello, Carmello

    1991-01-01

    High performance elements are simple finite elements constructed to deliver engineering accuracy with coarse arbitrary grids. This is part of a series on the variational basis of high-performance elements, with emphasis on those constructed with the free formulation (FF) and assumed natural strain (ANS) methods. Parametrized variational principles that provide a foundation for the FF and ANS methods, as well as for a combination of both are presented.

  5. Trust in building high-performing teams : conceptual approach

    OpenAIRE

    Hakanen, Mila; Häkkinen, Mia; Soudunsaari, Aki

    2015-01-01

    Team building is one of the key factors of success in business. This study highlights the key elements of building winning teams, where trust is one essential building block and top-level sports teams serve as instructive examples. This study highlights earlier findings that revealed a strong connection between trust and high-performing teams. High-performing teams need talented people but also constant trust-based cooperation. Trust supports cooperative...

  6. High Performance Circularly Polarized Antenna Based on Fractal EBG Structure

    OpenAIRE

    Bao, Xiulong; Ammann, Max; Ruvio, Giuseppe; John, Matthias

    2006-01-01

    Circularly polarized patch antennas have been widely applied in wireless communication system, global positioning system, etc., because of their low-profile, lightweight, ease of fabrication and low lost [1,2]. To achieve high performance for circularly polarized patch antennas, some new structures were reported in the literature, such as antennas array, stack layer antennas, using periodic structures [3-7], etc. In this paper, a high performance circularly polarized low frequency patch anten...

  7. A Low Power Low Voltage High Performance CMOS Current Mirror

    OpenAIRE

    Sirish Rao,; Sampath Kumar V

    2015-01-01

    The current mirrors are one of the most important circuits in designing the analog and mixed-mode circuit. A low power and low voltage high-performance CMOS current mirror with optimized input and output resistance are presented in this paper. SPICE simulations confirm the high-performance CMOS current mirror with power supply close to the threshold voltage of the transistor. In this paper, for achieving the low input resistance and a very high output resistance, the combination o...

  8. Partnership, high performance work systems and quality of working life

    OpenAIRE

    Upchurch, Martin; Danford, Andy; Richardson, Mike; Stewart, Paul; Tailby, Stephanie

    2008-01-01

    The paper measures the effects of workplace partnership and selected high performance work practices on four different dimensions of employee experience. Whilst the partnership– high performance work systems nexus seems to have little impact on employees’ job satisfaction or sense of attachment, it does, however, have a negative impact on both workplace stress and employee evaluations of union performance. The analysis thus questions common assumptions about the inevitability of ‘...

  9. High performance computing with WINDOWS HPC Server 2008

    OpenAIRE

    2010-01-01

    With the development of hardware, lower prices for hardware and the huge amounts of data in daily work, systems for High Performance Computing have become greatly expanded. Even Microsoft, with its cluster management programming environment called Windows HPC Server 2008, set foot in the field of High Performance Computing. In this thesis we describe the installation process of Windows HPC Server 2008 on a cluster of computers, its configuration, monitoring and diagnostic tools and user inter...

  10. NATO Advanced Study Institute on Hydrogen in Disordered and Amorphous Solids

    CERN Document Server

    Bowman, Robert

    1986-01-01

    This is the second volume in the NATO ASI series dealing with the topic of hydrogen in solids. The first (V. B76, Metal Hydrides) appeared five years ago and focussed primarily on crystalline phases of hydrided metallic systems. In the intervening period, the amorphous solid state has become an area of intense research activity, encompassing both metallic and non-metallic, e.g. semiconducting, systems. At the same time the problem of storage of hydrogen, which motivated the first ASI, continues to be important. In the case of metallic systems, there were early indications that metallic glasses and disordered alloys may be more corrosion resistant, less susceptible to embrittlement by hydrogen and have a higher hydrogen mobility than ordered metals or intermetallics. All of these properties are desirable for hydrogen storage. Subsequent research has shown that thermodynamic instability is a severe problem in many amorphous metal hydrides. The present ASI has provided an appropriate forum to focus on these issu...

  11. Graphene as tunable contact for high performance thin film transistor

    Science.gov (United States)

    Liu, Yuan

    performance and mechanical robustness. By using the graphene as a work-function tunable contact for amorphous indium gallium zinc oxide (IGZO) thin film, the vertical current flow across the graphene-IGZO junction can be effectively modulated by an external gate potential to enable VTFTs with a highest on-off ratio exceeding 105. The unique vertical transistor architecture can readily enable ultrashort channel devices with very high delivering current and exceptional mechanical flexibility. Furthermore, I will, demonstrate a new design strategy for vertical OTFT with ultra-short channel length without using conventional high-resolution lithography process. They can deliver a high current density over 1.8 A/ cm2 and thus enable a high cutoff frequency devices (~ 0.4 MHz) comparable with the ultra-short channel organic transistors. Importantly, with unique vertical architecture, the entire organic channel material is sandwiched between the source and drain electrodes and is thus naturally protected to ensure excellent air-stability. Finally I will present a new strategy by using graphene as the back electrodes to achieve Ohmic contact to MoS2. With a finite density of states, the Fermi level of graphene can be readily tuned by a gate potential to enable a nearly perfect band alignment with MoS2. For the first time, a transparent contact to MoS2 is demonstrated with zero contact barrier and linear output behaviour at cryogenic temperatures (down to 1.9 K) for both monolayer and multilayer MoS2. Benefiting from the barrier-free transparent contacts, we show that a metal-insulator-transition (MIT) can be observed in a two-terminal MoS2 device, a phenomenon that could be easily masked by Schottky barriers found in conventional metal-contacted MoS2 devices. With further passivation by boron nitride (BN) encapsulation, we demonstrate a record-high extrinsic (two-terminal) field effect mobility up to 1300 cm2/V s in MoS2 at low temperature. These findings can open up exciting new

  12. Crystallization of Fe78Si9B13 Bulk Crystaline/Amorphous (c/a) Composite

    Institute of Scientific and Technical Information of China (English)

    JIN Shifeng; WANG Weimin; NIU Yuchao; ZHANG Jiteng; LI Guihua; BIAN Xiufang

    2008-01-01

    A metallic crystalline/amorphous (c/a) bulk composite was prepared by the slow cooling method after remelting the amorphous Fe78Si9B13 ribbon. By X-ray diffraction (XRD),differential scanning calorimetry (DSC) and scanning electron microscope (SEM), the composite consists of the primary dendrite a-Fe (without Si) as well as the amorphous matrix. After being anneal at 800 K, the uniform spheroid particles are formed in the c/a composite, which does not form in the amorphous ribbon under the various annealing process. Energy dispersive analysis of X-rays (EDAX), SEM and XRD were applied to give more detailed information. The formation and evolution of the particle may stimulate the possible application of the Fe-matrix amorphous alloy.

  13. High performance a-IGZO thin-film transistors with mf-PVD SiO2 as an etch-stop-layer

    NARCIS (Netherlands)

    Nag, M.; Steudel, S.; Bhoolokam, A.; Chasin, A.; Rockele, M.; Myny, K.; Maas, J.; Fritz, T.; Trube, J.; Groeseneken, G.; Heremans, P.

    2014-01-01

    In this work, we report on high-performance bottom-gate top-contact (BGTC) amorphous-Indium-Gallium-Zinc-Oxide (a-IGZO) thin-film transistor (TFT) with SiO2 as an etch-stop-layer (ESL) deposited by medium frequency physical vapor deposition (mf-PVD). The TFTs show field-effect mobility (μFE) of 16.0

  14. Nanostructures having crystalline and amorphous phases

    Science.gov (United States)

    Mao, Samuel S; Chen, Xiaobo

    2015-04-28

    The present invention includes a nanostructure, a method of making thereof, and a method of photocatalysis. In one embodiment, the nanostructure includes a crystalline phase and an amorphous phase in contact with the crystalline phase. Each of the crystalline and amorphous phases has at least one dimension on a nanometer scale. In another embodiment, the nanostructure includes a nanoparticle comprising a crystalline phase and an amorphous phase. The amorphous phase is in a selected amount. In another embodiment, the nanostructure includes crystalline titanium dioxide and amorphous titanium dioxide in contact with the crystalline titanium dioxide. Each of the crystalline and amorphous titanium dioxide has at least one dimension on a nanometer scale.

  15. Can We Build a Truly High Performance Computer Which is Flexible and Transparent?

    KAUST Repository

    Rojas, Jhonathan P.

    2013-09-10

    State-of-the art computers need high performance transistors, which consume ultra-low power resulting in longer battery lifetime. Billions of transistors are integrated neatly using matured silicon fabrication process to maintain the performance per cost advantage. In that context, low-cost mono-crystalline bulk silicon (100) based high performance transistors are considered as the heart of today\\'s computers. One limitation is silicon\\'s rigidity and brittleness. Here we show a generic batch process to convert high performance silicon electronics into flexible and semi-transparent one while retaining its performance, process compatibility, integration density and cost. We demonstrate high-k/metal gate stack based p-type metal oxide semiconductor field effect transistors on 4 inch silicon fabric released from bulk silicon (100) wafers with sub-threshold swing of 80 mV dec(-1) and on/off ratio of near 10(4) within 10% device uniformity with a minimum bending radius of 5 mm and an average transmittance of similar to 7% in the visible spectrum.

  16. Amorphization of Crystalline Water Ice

    CERN Document Server

    Zheng, Weijun; Kaiser, Ralf I

    2008-01-01

    We conducted a systematic experimental study to investigate the amorphization of crystalline ice by irradiation in the 10-50 K temperature range with 5 keV electrons at a dose of ~140 eV per molecule. We found that crystalline water ice can be converted partially to amorphous ice by electron irradiation. Our experiments showed that some of the 1.65-micrometer band survived the irradiation, to a degree that depends on the temperature, demonstrating that there is a balance between thermal recrystallization and irradiation-induced amorphization, with thermal recrystallizaton dominant at higher temperatures. At 50 K, recrystallization due to thermal effects is strong, and most of the crystalline ice survived. Temperatures of most known objects in the solar system, including Jovian satellites, Saturnian satellites, and Kuiper belt objects, are equal to or above 50 K, this might explain why water ice detected on those objects is mostly crystalline.

  17. High-performance liquid-catalyst fuel cell for direct biomass-into-electricity conversion.

    Science.gov (United States)

    Liu, Wei; Mu, Wei; Deng, Yulin

    2014-12-01

    Herein, we report high-performance fuel cells that are catalyzed solely by polyoxometalate (POM) solution without any solid metal or metal oxide. The novel design of the liquid-catalyst fuel cells (LCFC) changes the traditional gas-solid-surface heterogeneous reactions to liquid-catalysis reactions. With this design, raw biomasses, such as cellulose, starch, and even grass or wood powders can be directly converted into electricity. The power densities of the fuel cell with switchgrass (dry powder) and bush allamanda (freshly collected) are 44 mW cm(-2) and 51 mW cm(-2) respectively. For the cellulose-based biomass fuel cell, the power density is almost 3000 times higher than that of cellulose-based microbial fuel cells. Unlike noble-metal catalysts, POMs are tolerant to most organic and inorganic contaminants. Therefore, almost any raw biomass can be used directly to produce electricity without prior purification. PMID:25283435

  18. Progress and Challenges in High Performance Computer Technology

    Institute of Scientific and Technical Information of China (English)

    Xue-Jun Yang; Yong Dou; Qing-Feng Hu

    2006-01-01

    High performance computers provide strategic computing power in the construction of national economy and defense, and become one of symbols of the country's overall strength. Over 30 years, with the supports of governments, the technology of high performance computers is in the process of rapid development, during which the computing performance increases nearly 3 million times and the processors number expands over 10 hundred thousands times. To solve the critical issues related with parallel efficiency and scalability, scientific researchers pursued extensive theoretical studies and technical innovations. The paper briefly looks back the course of building high performance computer systems both at home and abroad,and summarizes the significant breakthroughs of international high performance computer technology. We also overview the technology progress of China in the area of parallel computer architecture, parallel operating system and resource management,parallel compiler and performance optimization, environment for parallel programming and network computing. Finally, we examine the challenging issues, "memory wall", system scalability and "power wall", and discuss the issues of high productivity computers, which is the trend in building next generation high performance computers.

  19. Resource estimation in high performance medical image computing.

    Science.gov (United States)

    Banalagay, Rueben; Covington, Kelsie Jade; Wilkes, D M; Landman, Bennett A

    2014-10-01

    Medical imaging analysis processes often involve the concatenation of many steps (e.g., multi-stage scripts) to integrate and realize advancements from image acquisition, image processing, and computational analysis. With the dramatic increase in data size for medical imaging studies (e.g., improved resolution, higher throughput acquisition, shared databases), interesting study designs are becoming intractable or impractical on individual workstations and servers. Modern pipeline environments provide control structures to distribute computational load in high performance computing (HPC) environments. However, high performance computing environments are often shared resources, and scheduling computation across these resources necessitates higher level modeling of resource utilization. Submission of 'jobs' requires an estimate of the CPU runtime and memory usage. The resource requirements for medical image processing algorithms are difficult to predict since the requirements can vary greatly between different machines, different execution instances, and different data inputs. Poor resource estimates can lead to wasted resources in high performance environments due to incomplete executions and extended queue wait times. Hence, resource estimation is becoming a major hurdle for medical image processing algorithms to efficiently leverage high performance computing environments. Herein, we present our implementation of a resource estimation system to overcome these difficulties and ultimately provide users with the ability to more efficiently utilize high performance computing resources.

  20. In situ catalytic pyrolysis of lignocellulose using alkali-modified amorphous silica alumina

    NARCIS (Netherlands)

    Zabeti, M.; Nguyen, T. S.; Lefferts, L.; Heeres, H. J.; Seshan, K.

    2012-01-01

    Canadian pinewood was pyrolyzed at 450 degrees C in an Infrared oven and the pyrolysis vapors were converted by passing through a catalyst bed at 450 degrees C. The catalysts studied were amorphous silica alumina (ASA) containing alkali metal or alkaline earth metal species including Na, K, Cs, Mg a

  1. Amorphous Alloy Membranes for High Temperature Hydrogen Separation

    Energy Technology Data Exchange (ETDEWEB)

    Coulter, K

    2013-09-30

    At the beginning of this project, thin film amorphous alloy membranes were considered a nascent but promising new technology for industrial-scale hydrogen gas separations from coal- derived syngas. This project used a combination of theoretical modeling, advanced physical vapor deposition fabricating, and laboratory and gasifier testing to develop amorphous alloy membranes that had the potential to meet Department of Energy (DOE) targets in the testing strategies outlined in the NETL Membrane Test Protocol. The project is complete with Southwest Research Institute® (SwRI®), Georgia Institute of Technology (GT), and Western Research Institute (WRI) having all operated independently and concurrently. GT studied the hydrogen transport properties of several amorphous alloys and found that ZrCu and ZrCuTi were the most promising candidates. GT also evaluated the hydrogen transport properties of V, Nb and Ta membranes coated with different transition-metal carbides (TMCs) (TM = Ti, Hf, Zr) catalytic layers by employing first-principles calculations together with statistical mechanics methods and determined that TiC was the most promising material to provide catalytic hydrogen dissociation. SwRI developed magnetron coating techniques to deposit a range of amorphous alloys onto both porous discs and tubular substrates. Unfortunately none of the amorphous alloys could be deposited without pinhole defects that undermined the selectivity of the membranes. WRI tested the thermal properties of the ZrCu and ZrNi alloys and found that under reducing environments the upper temperature limit of operation without recrystallization is ~250 °C. There were four publications generated from this project with two additional manuscripts in progress and six presentations were made at national and international technical conferences. The combination of the pinhole defects and the lack of high temperature stability make the theoretically identified most promising candidate amorphous alloys

  2. On amorphization and nanocomposite formation in Al–Ni–Ti system by mechanical alloying

    Indian Academy of Sciences (India)

    K Das; G K Dey; B S Murty; S K Pabi

    2005-11-01

    Amorphous structure generated by mechanical alloying (MA) is often used as a precursor for generating nanocomposites through controlled devitrification. The amorphous forming composition range of ternary Al–Ni–Ti system was calculated using the extended Miedema's semi-empirical model. Eleven compositions of this system showing a wide range of negative enthalpy of mixing (− mix) and amorphization (− amor) of the constituent elements were selected for synthesis by MA. The Al88Ni6Ti6 alloy with relatively small negative mix (−0.4 kJ/mol) and amor (−14.8 kJ/mol) became completely amorphous after 120 h of milling, which is possibly the first report of complete amorphization of an Al-based rare earth element free Al–TM–TM system (TM = transition metal) by MA. The alloys of other compositions selected had much more negative mix and amor; but they yielded either nanocomposites of partial amorphous and crystalline structure or no amorphous phase at all in the as-milled condition, evidencing a high degree of stability of the intermetallic phases under the MA environment. Hence, the negative mix and amor are not so reliable for predicting the amorphization in the present system by MA.

  3. Joint ESRF-Cecam workshop polymorphous in liquid and amorphous matter

    Energy Technology Data Exchange (ETDEWEB)

    Price, D.L.; Hennet, L.; Krishnan, S.; Sinn, H.; Alp, E.E.; Saboungi, M.L.; Holland-Moritz, D.; Mossa, S.; Tarjus, G.; Trapananti, A.; Di Cicco, A.; Filipponi, A.; Tanaka, H.; Soper, A.K.; Strassle, Th.; Klotz, S.; Hamel, G.; Nelmes, R.J.; Loveday, J.S.; Rousse, G.; Canny, B.; Chervin, J.C.; Saitta, M.; Marek Koza, M.; Schober, H.; Geiger, A.; Brovchenko, I.; Oleinikova, A.; Strassle, T.; Reichert, H.; Jakse, N.; Lebacq, O.; Pasturel, A.; Salmon, P.S.; Martin, R.A.; Massobrio, C.; Poon, W.C.K.; Pham, K.N.; Voigtmann, Th.; Egelhaaf, S.U.; Pusey, P.N.; Petukhov, A.V.; Dolbnya, I.P.; Vroege, G.J.; Lekkerkerker, H.N.W.; Konig, H.; Keen, D.A.; Benedetti, L.R.; Sihachakr, D.; Dewaele, A.; Weck, G.; Crichton, W.; Mezouar, M.; Loubeyre, P.; Shimojo, F.; Ferlat, G.; San Miguel, A.; Xu, H.; Martinez-Garcia, D.; Zuniga, J.; Munoz-Sanjose, V.; Felipponi, A.; Panfilis, S. de; Di Cicco, A.; Guthrie, M.; Tulk, C.A.; Bemore, C.J.; Xu, J.; Yarger, J.L.; Mao, H.K.; Hemley, R.J

    2004-07-01

    This workshop is dedicated to new trends in the simulation and experimental studies of liquid and amorphous matter. Particular emphasis is given to polymorphism in equilibrium and under-cooled metastable liquids, glasses and to amorphous network-forming systems. 5 mains sessions over the 3 days have been organized: 1) under-cooled liquid metals, 2) liquid, glassy and amorphous semiconductors, 3) water and related systems, 4) colloids, macro-molecules and biological cells, and 5) state-of-the-art in experimental and theoretical investigations. This document gathers the abstracts of the presentations.

  4. High Performance Fiber Reinforced Cement Composites 6 HPFRCC 6

    CERN Document Server

    Reinhardt, Hans; Naaman, A

    2012-01-01

    High Performance Fiber Reinforced Cement Composites (HPFRCC) represent a class of cement composites whose stress-strain response in tension undergoes strain hardening behaviour accompanied by multiple cracking, leading to a high strain prior to failure. The primary objective of this International Workshop was to provide a compendium of up-to-date information on the most recent developments and research advances in the field of High Performance Fiber Reinforced Cement Composites. Approximately 65 contributions from leading world experts are assembled in these proceedings and provide an authoritative perspective on the subject. Special topics include fresh and hardening state properties; self-compacting mixtures; mechanical behavior under compressive, tensile, and shear loading; structural applications; impact, earthquake and fire resistance; durability issues; ultra-high performance fiber reinforced concrete; and textile reinforced concrete. Target readers: graduate students, researchers, fiber producers, desi...

  5. A Component Architecture for High-Performance Scientific Computing

    Energy Technology Data Exchange (ETDEWEB)

    Bernholdt, D E; Allan, B A; Armstrong, R; Bertrand, F; Chiu, K; Dahlgren, T L; Damevski, K; Elwasif, W R; Epperly, T W; Govindaraju, M; Katz, D S; Kohl, J A; Krishnan, M; Kumfert, G; Larson, J W; Lefantzi, S; Lewis, M J; Malony, A D; McInnes, L C; Nieplocha, J; Norris, B; Parker, S G; Ray, J; Shende, S; Windus, T L; Zhou, S

    2004-12-14

    The Common Component Architecture (CCA) provides a means for software developers to manage the complexity of large-scale scientific simulations and to move toward a plug-and-play environment for high-performance computing. In the scientific computing context, component models also promote collaboration using independently developed software, thereby allowing particular individuals or groups to focus on the aspects of greatest interest to them. The CCA supports parallel and distributed computing as well as local high-performance connections between components in a language-independent manner. The design places minimal requirements on components and thus facilitates the integration of existing code into the CCA environment. The CCA model imposes minimal overhead to minimize the impact on application performance. The focus on high performance distinguishes the CCA from most other component models. The CCA is being applied within an increasing range of disciplines, including combustion research, global climate simulation, and computational chemistry.

  6. Operating System Support for High-Performance Solid State Drives

    DEFF Research Database (Denmark)

    Bjørling, Matias

    of the operating system in reducing the gap, and enabling new forms of communication and even co-design between applications and high-performance SSDs. More specifically, we studied the storage layers within the Linux kernel. We explore the following issues: (i) what are the limitations of the legacy block...... interface and its cost in the context of high-performance SSDs? (ii) Can the Linux kernel block layer cope with high-performance SSDs? (iii) What is an alternative to the legacy block interface? How to explore the design space? (iv) How about exposing SSD characteristics to the host in order to enable...... of this thesis (the multi-queue block layer and LightNVM) are now an integral part of the Linux kernel....

  7. A Comparative Analysis of some High Performance Computing Technologies

    Directory of Open Access Journals (Sweden)

    Minakshi Tripathy

    2014-10-01

    Full Text Available Computing is an evolutionary process. As part of this evolution, the computing requirements driven by applications have always outpaced the available technology. The system designers have been always seeking for faster and more efficient systems of computing. During the past decade, many different computer systems supporting high performance computing have emerged. Their taxonomy is based on how their processors, memory and interconnect are laid out. Today’s applications require high computational power as well as high communication performance. The high performance computing provides an approach to parallel processing that yields super computer level performance solving incredibly large and complex problems. This trend makes it very promising to build high performance computing environment with a cost effective approach.

  8. A Component Architecture for High-Performance Scientific Computing

    Energy Technology Data Exchange (ETDEWEB)

    Bernholdt, David E; Allan, Benjamin A; Armstrong, Robert C; Bertrand, Felipe; Chiu, Kenneth; Dahlgren, Tamara L; Damevski, Kostadin; Elwasif, Wael R; Epperly, Thomas G; Govindaraju, Madhusudhan; Katz, Daniel S; Kohl, James A; Krishnan, Manoj Kumar; Kumfert, Gary K; Larson, J Walter; Lefantzi, Sophia; Lewis, Michael J; Malony, Allen D; McInnes, Lois C; Nieplocha, Jarek; Norris, Boyana; Parker, Steven G; Ray, Jaideep; Shende, Sameer; Windus, Theresa L; Zhou, Shujia

    2006-07-03

    The Common Component Architecture (CCA) provides a means for software developers to manage the complexity of large-scale scientific simulations and to move toward a plug-and-play environment for high-performance computing. In the scientific computing context, component models also promote collaboration using independently developed software, thereby allowing particular individuals or groups to focus on the aspects of greatest interest to them. The CCA supports parallel and distributed computing as well as local high-performance connections between components in a language-independent manner. The design places minimal requirements on components and thus facilitates the integration of existing code into the CCA environment. The CCA model imposes minimal overhead to minimize the impact on application performance. The focus on high performance distinguishes the CCA from most other component models. The CCA is being applied within an increasing range of disciplines, including combustion research, global climate simulation, and computational chemistry.

  9. Connection of the Hall coefficient with some parameters in amorphous and crystalline ferromagnetics

    Directory of Open Access Journals (Sweden)

    Yu.A. Kunyts’ky

    2010-01-01

    Full Text Available For the series of alloys based on iron metal group the temperature dependences of Hall coefficient, resistivity, saturation magnetization in the amorphous and crystalline states are investigated. Within the Kondorsky-Vedyaev-Granovski theory framework the relationship between anomalous Hall coefficient Rs specific resistivity ρ and saturation magnetization Js was determined. The changes mechanism for some physical parameters of amorphous alloys was revealed in the case of the heat treatment and for the transition to the crystalline state as well.

  10. CRPC research into linear algebra software for high performance computers

    Energy Technology Data Exchange (ETDEWEB)

    Choi, J.; Walker, D.W. [Oak Ridge National Lab., TN (United States). Mathematical Sciences Section; Dongarra, J.J. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Computer Science]|[Oak Ridge National Lab., TN (United States). Mathematical Sciences Section; Pozo, R. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Computer Science; Sorensen, D.C. [Rice Univ., Houston, TX (United States). Dept. of Computational and Applied Mathematics

    1994-12-31

    In this paper the authors look at a number of approaches being investigated in the Center for Research on Parallel Computation (CRPC) to develop linear algebra software for high-performance computers. These approaches are exemplified by the LAPACK, templates, and ARPACK projects. LAPACK is a software library for performing dense and banded linear algebra computations, and was designed to run efficiently on high-performance computers. The authors focus on the design of the distributed-memory version of LAPACK, and on an object-oriented interface to LAPACK.

  11. DEVELOPING A NEW GENERATION OF HIGH PERFORMANCE COMPOSITE CEMENT

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper proposed a new generation of high performance composite cement which is designed according to the optimization of composition and structure of cement paste and is manufactured by blending the different components with special composite techniques. Each of these components has its different special property, and should be compatible with each other and match each other, and the properties of them are complementary mutually. At present, such kind of high performance composite cement can be manufactured with high reactivity cement clinker, ground granulated blast-furnace slag, high grade fly ash, silica fume etc.

  12. Visualization and Data Analysis for High-Performance Computing

    Energy Technology Data Exchange (ETDEWEB)

    Sewell, Christopher Meyer [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-27

    This is a set of slides from a guest lecture for a class at the University of Texas, El Paso on visualization and data analysis for high-performance computing. The topics covered are the following: trends in high-performance computing; scientific visualization, such as OpenGL, ray tracing and volume rendering, VTK, and ParaView; data science at scale, such as in-situ visualization, image databases, distributed memory parallelism, shared memory parallelism, VTK-m, "big data", and then an analysis example.

  13. Designing high-Performance layered thermoelectric materials through orbital engineering

    DEFF Research Database (Denmark)

    Zhang, Jiawei; Song, Lirong; Madsen, Georg K. H.;

    2016-01-01

    Thermoelectric technology, which possesses potential application in recycling industrial waste heat as energy, calls for novel high-performance materials. The systematic exploration of novel thermoelectric materials with excellent electronic transport properties is severely hindered by limited...... insight into the underlying bonding orbitals of atomic structures. Here we propose a simple yet successful strategy to discover and design high-performance layered thermoelectric materials through minimizing the crystal field splitting energy of orbitals to realize high orbital degeneracy. The approach......-abundant elements. Moreover, the approach can be extended to several other non-cubic materials, thereby substantially accelerating the screening and design of new thermoelectric materials....

  14. Evaluation of GPFS Connectivity Over High-Performance Networks

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, Jay; Canon, Shane; Andrews, Matthew

    2009-02-17

    We present the results of an evaluation of new features of the latest release of IBM's GPFS filesystem (v3.2). We investigate different ways of connecting to a high-performance GPFS filesystem from a remote cluster using Infiniband (IB) and 10 Gigabit Ethernet. We also examine the performance of the GPFS filesystem with both serial and parallel I/O. Finally, we also present our recommendations for effective ways of utilizing high-bandwidth networks for high-performance I/O to parallel file systems.

  15. Contemporary high performance computing from petascale toward exascale

    CERN Document Server

    Vetter, Jeffrey S

    2013-01-01

    Contemporary High Performance Computing: From Petascale toward Exascale focuses on the ecosystems surrounding the world's leading centers for high performance computing (HPC). It covers many of the important factors involved in each ecosystem: computer architectures, software, applications, facilities, and sponsors. The first part of the book examines significant trends in HPC systems, including computer architectures, applications, performance, and software. It discusses the growth from terascale to petascale computing and the influence of the TOP500 and Green500 lists. The second part of the

  16. High performance computing and communications: FY 1997 implementation plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    The High Performance Computing and Communications (HPCC) Program was formally authorized by passage, with bipartisan support, of the High-Performance Computing Act of 1991, signed on December 9, 1991. The original Program, in which eight Federal agencies participated, has now grown to twelve agencies. This Plan provides a detailed description of the agencies` FY 1996 HPCC accomplishments and FY 1997 HPCC plans. Section 3 of this Plan provides an overview of the HPCC Program. Section 4 contains more detailed definitions of the Program Component Areas, with an emphasis on the overall directions and milestones planned for each PCA. Appendix A provides a detailed look at HPCC Program activities within each agency.

  17. Flex Fatigue Property and Fractography of High Performance Fibers

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hua-peng; LIU Xiao-yan; SHI Mei-wu; ZHANG Jian-chun; LAI Kan; WANG Shan-yuan

    2002-01-01

    The effects of pre-stress and bending angle on the flex fatigue lifetimes of para- aramds have been studied choosing the Twaron 2000 high performance filament as the studying subject by use of the self-developed flex fatigue apparatus. The fractography of the fatiguebreaking end of the single filaments has been obtained and the fatigue-breaking mechanisms have been analyzed using the LM and SEM. The differences of the fatigue properties and fractography of a variety of high performance fibers such as Kevlar 129, Kevlar 29 and UHMW PE have been discussed.

  18. Amorphous-silicon cell reliability testing

    Science.gov (United States)

    Lathrop, J. W.

    1985-01-01

    The work on reliability testing of solar cells is discussed. Results are given on initial temperature and humidity tests of amorphous silicon devices. Calibration and measurement procedures for amorphous and crystalline cells are given. Temperature stress levels are diagrammed.

  19. Investigation of Sb diffusion in amorphous silicon

    OpenAIRE

    Csik, A.; Langer, G A; Erdelyi, G.; Beke, D. L.; Erdelyi, Z.; Vad, K.

    2009-01-01

    Amorphous silicon materials and its alloys become extensively used in some technical applications involving large area of the microelectronic and optoelectronic devices. However, the amorphous-crystalline transition, segregation and diffusion processes still have numerous unanswered questions. In this work we study the Sb diffusion into an amorphous Si film by means of Secondary Neutral Mass Spectrometry (SNMS). Amorphous Si/Si1-xSbx/Si tri-layer samples with 5 at% antimony concentration were...

  20. Atomistic Models of Amorphous Semiconductors

    NARCIS (Netherlands)

    Jarolimek, K.

    2011-01-01

    Crystalline silicon is probably the best studied material, widely used by the semiconductor industry. The subject of this thesis is an intriguing form of this element namely amorphous silicon. It can contain a varying amount of hydrogen and is denoted as a-Si:H. It completely lacks the neat long ran

  1. An amorphous phase formation at palladium / silicon oxide (Pd/SiO{sub x}) interface through electron irradiation - electronic excitation process

    Energy Technology Data Exchange (ETDEWEB)

    Nagase, Takeshi, E-mail: t-nagase@uhvem.osaka-u.ac.jp [Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, 7-1, Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1, Yamada-Oka, Suita, Osaka 565-0871 (Japan); Yamashita, Ryo; Yabuuchi, Atsushi [Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1, Yamada-Oka, Suita, Osaka 565-0871 (Japan); Lee, Jung-Goo [Powder & Ceramics Division, Korea Institute of Materials Science, 66 Sangnam-dong, Changwon, Kyungsangnam-Do 641-101 (Korea, Republic of)

    2015-11-15

    A Pd-Si amorphous phase was formed at a palladium/silicon oxide (Pd/SiO{sub x}) interface at room temperature by electron irradiation at acceleration voltages ranging between 25 kV and 200 kV. Solid-state amorphization was stimulated without the electron knock-on effects. The total dose required for the solid-state amorphization decreases with decreasing acceleration voltage. This is the first report on electron irradiation induced metallic amorphous formation caused by the electronic excitation at metal/silicon oxide interface.

  2. Optical interconnection networks for high-performance computing systems

    International Nuclear Information System (INIS)

    Enabled by silicon photonic technology, optical interconnection networks have the potential to be a key disruptive technology in computing and communication industries. The enduring pursuit of performance gains in computing, combined with stringent power constraints, has fostered the ever-growing computational parallelism associated with chip multiprocessors, memory systems, high-performance computing systems and data centers. Sustaining these parallelism growths introduces unique challenges for on- and off-chip communications, shifting the focus toward novel and fundamentally different communication approaches. Chip-scale photonic interconnection networks, enabled by high-performance silicon photonic devices, offer unprecedented bandwidth scalability with reduced power consumption. We demonstrate that the silicon photonic platforms have already produced all the high-performance photonic devices required to realize these types of networks. Through extensive empirical characterization in much of our work, we demonstrate such feasibility of waveguides, modulators, switches and photodetectors. We also demonstrate systems that simultaneously combine many functionalities to achieve more complex building blocks. We propose novel silicon photonic devices, subsystems, network topologies and architectures to enable unprecedented performance of these photonic interconnection networks. Furthermore, the advantages of photonic interconnection networks extend far beyond the chip, offering advanced communication environments for memory systems, high-performance computing systems, and data centers. (review article)

  3. Enabling High-Performance Computing as a Service

    KAUST Repository

    AbdelBaky, Moustafa

    2012-10-01

    With the right software infrastructure, clouds can provide scientists with as a service access to high-performance computing resources. An award-winning prototype framework transforms the Blue Gene/P system into an elastic cloud to run a representative HPC application. © 2012 IEEE.

  4. Replica-Based High-Performance Tuple Space Computing

    DEFF Research Database (Denmark)

    Andric, Marina; De Nicola, Rocco; Lluch Lafuente, Alberto

    2015-01-01

    We present the tuple-based coordination language RepliKlaim, which enriches Klaim with primitives for replica-aware coordination. Our overall goal is to offer suitable solutions to the challenging problems of data distribution and locality in large-scale high performance computing. In particular...

  5. Monitoring aged reversed-phase high performance liquid chromatography columns

    NARCIS (Netherlands)

    Bolck, A; Smilde, AK; Bruins, CHP

    1999-01-01

    In this paper, a new approach for the quality assessment of routinely used reversed-phase high performance liquid chromatography columns is presented. A used column is not directly considered deteriorated when changes in retention occur. If attention is paid to the type and magnitude of the changes,

  6. TMD-Based Structural Control of High Performance Steel Bridges

    International Nuclear Information System (INIS)

    The purpose of this study is to investigate the effectiveness of structural control using tuned mass damper (TMD) for suppressing excessive traffic induced vibration of high performance steel bridge. The study considered 1-span steel plate girder bridge and bridge-vehicle interaction using HS-24 truck model. A numerical model of steel plate girder, traffic load, and TMD is constructed and time history analysis is performed using commercial structural analysis program ABAQUS 6.10. Results from analyses show that high performance steel bridge has dynamic serviceability problem, compared to relatively low performance steel bridge. Therefore, the structural control using TMD is implemented in order to alleviate dynamic serviceability problems. TMD is applied to the bridge with high performance steel and then vertical vibration due to dynamic behavior is assessed again. In consequent, by using TMD, it is confirmed that the residual amplitude is appreciably reduced by 85% in steady-state vibration. Moreover, vibration serviceability assessment using 'Reiher-Meister Curve' is also remarkably improved. As a result, this paper provides the guideline for economical design of I-girder using high performance steel and evaluates the effectiveness of structural control using TMD, simultaneously.

  7. Resolution of RNA using high-performance liquid chromatography

    NARCIS (Netherlands)

    Mclaughlin, L.W.; Bischoff, Rainer

    1987-01-01

    High-performance liquid chromatographic techniques can be very effective for the resolution and isolation of nucleic acids. The characteristic ionic (phosphodiesters) and hydrophobic (nucleobases) properties of RNAs can be exploited for their separation. In this respect anion-exchange and reversed-p

  8. High performance fuel electrode for a solid oxide electrochemical cell

    DEFF Research Database (Denmark)

    2013-01-01

    A high performance anode (fuel electrode) for use in a solid oxide electrochemical cell is obtained by a process comprising the steps of (a) providing a suitably doped, stabilized zirconium oxide electrolyte, such as YSZ,ScYSZ, with an anode side having a coating of electronically conductive...

  9. Beyond the simulator : instructions for high-performance tasks

    NARCIS (Netherlands)

    Emmerik, van Martijn Louis

    2004-01-01

    High-performance tasks are difficult because of their complexity and the fact that they are time critical. Because they often have to be executed in a dangerous or hostile environment they require an extensive amount of training before they can be executed safely. From an operational as well as a di

  10. Computer science of the high performance; Informatica del alto rendimiento

    Energy Technology Data Exchange (ETDEWEB)

    Moraleda, A.

    2008-07-01

    The high performance computing is taking shape as a powerful accelerator of the process of innovation, to drastically reduce the waiting times for access to the results and the findings in a growing number of processes and activities as complex and important as medicine, genetics, pharmacology, environment, natural resources management or the simulation of complex processes in a wide variety of industries. (Author)

  11. High Performance Computing tools for the Integrated Tokamak Modelling project

    Energy Technology Data Exchange (ETDEWEB)

    Guillerminet, B., E-mail: bernard.guillerminet@cea.f [Association Euratom-CEA sur la Fusion, IRFM, DSM, CEA Cadarache (France); Plasencia, I. Campos [Instituto de Fisica de Cantabria (IFCA), CSIC, Santander (Spain); Haefele, M. [Universite Louis Pasteur, Strasbourg (France); Iannone, F. [EURATOM/ENEA Fusion Association, Frascati (Italy); Jackson, A. [University of Edinburgh (EPCC) (United Kingdom); Manduchi, G. [EURATOM/ENEA Fusion Association, Padova (Italy); Plociennik, M. [Poznan Supercomputing and Networking Center (PSNC) (Poland); Sonnendrucker, E. [Universite Louis Pasteur, Strasbourg (France); Strand, P. [Chalmers University of Technology (Sweden); Owsiak, M. [Poznan Supercomputing and Networking Center (PSNC) (Poland)

    2010-07-15

    Fusion Modelling and Simulation are very challenging and the High Performance Computing issues are addressed here. Toolset for jobs launching and scheduling, data communication and visualization have been developed by the EUFORIA project and used with a plasma edge simulation code.

  12. High-performance perovskite-graphene hybrid photodetector.

    Science.gov (United States)

    Lee, Youngbin; Kwon, Jeong; Hwang, Euyheon; Ra, Chang-Ho; Yoo, Won Jong; Ahn, Jong-Hyun; Park, Jong Hyeok; Cho, Jeong Ho

    2015-01-01

    A high-performance novel photodetector is demonstrated, which consists of graphene and CH3 NH3 PbI3 perovskite layers. The resulting hybrid photodetector exhibits a dramatically enhanced photo responsivity (180 A/W) and effective quantum efficiency (5× 10(4) %) over a broad bandwidth within the UV and visible ranges.

  13. High-Performance Matrix-Vector Multiplication on the GPU

    DEFF Research Database (Denmark)

    Sørensen, Hans Henrik Brandenborg

    2012-01-01

    In this paper, we develop a high-performance GPU kernel for one of the most popular dense linear algebra operations, the matrix-vector multiplication. The target hardware is the most recent Nvidia Tesla 20-series (Fermi architecture), which is designed from the ground up for scientific computing...

  14. High performance sport and sustainability: a contradiction of terms?

    NARCIS (Netherlands)

    Barker, D.; Barker-Ruchtia, N.; Wals, A.E.J.; Tinning, R.

    2014-01-01

    Success in high performance sport has always been highly valued. Today, lucrative contracts, sponsorship deals and opportunities for celebrity status are balanced against substantial time spent training and high chances of failure. With pressure mounting on athletes to make the most of their athleti

  15. High-Performance Management Practices and Employee Outcomes in Denmark

    DEFF Research Database (Denmark)

    Cristini, Annalisa; Eriksson, Tor; Pozzoli, Dario

    High-performance work practices are frequently considered to have positive effects on corporate performance, but what do they do for employees? After showing that organizational innovation is indeed positively associated with firm performance, we investigate whether high-involvement work practice...

  16. Mallow carotenoids determined by high-performance liquid chromatography

    Science.gov (United States)

    Mallow (corchorus olitorius) is a green vegetable, which is widely consumed either fresh or dry by Middle East population. This study was carried out to determine the contents of major carotenoids quantitatively in mallow, by using a High Performance Liquid Chromatography (HPLC) equipped with a Bis...

  17. High-Performance Liquid Chromatography-Mass Spectrometry.

    Science.gov (United States)

    Vestal, Marvin L.

    1984-01-01

    Reviews techniques for online coupling of high-performance liquid chromatography with mass spectrometry, emphasizing those suitable for application to nonvolatile samples. Also summarizes the present status, strengths, and weaknesses of various techniques and discusses potential applications of recently developed techniques for combined liquid…

  18. Quantification of Tea Flavonoids by High Performance Liquid Chromatography

    Science.gov (United States)

    Freeman, Jessica D.; Niemeyer, Emily D.

    2008-01-01

    We have developed a laboratory experiment that uses high performance liquid chromatography (HPLC) to quantify flavonoid levels in a variety of commercial teas. Specifically, this experiment analyzes a group of flavonoids known as catechins, plant-derived polyphenolic compounds commonly found in many foods and beverages, including green and black…

  19. Benchmarking High Performance Architectures With Natural Language Processing Algorithms

    OpenAIRE

    Marcin Kuta; Jacek Kitowski

    2011-01-01

    Natural Language Processing algorithms are resource demanding, especially when tuning toinflective language like Polish is needed. The paper presents time and memory requirementsof part of speech tagging and clustering algorithms applied to two corpora of the Polishlanguage. The algorithms are benchmarked on three high performance platforms of differentarchitectures. Additionally sequential versions and OpenMP implementations of clusteringalgorithms were compared.

  20. National Best Practices Manual for Building High Performance Schools

    Science.gov (United States)

    US Department of Energy, 2007

    2007-01-01

    The U.S. Department of Energy's Rebuild America EnergySmart Schools program provides school boards, administrators, and design staff with guidance to help make informed decisions about energy and environmental issues important to school systems and communities. "The National Best Practices Manual for Building High Performance Schools" is a part of…