National Library of Energy BETA

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  1. VEHICLE ACCESS PORTALS TA-48 Vicinity TA-36 Vicinity

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Pajarito Corridor (Map 4) VEHICLE ACCESS PORTALS TA-48 Vicinity TA-36 Vicinity Drivers of delivery vehicles entering Pajarito Road bounded by NM Highway 4 and Diamond Drive must...

  2. Tran_Presentation

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    acid media into a deep eutectic solvent using bis(2-ethylhexyl) phosphate Presented by: Kate Tran, Eastern Kentucky University Merinda Volia, Department of Nuclear Engineering, Texas A&M University Dr. Evgeny Tereshatov, Cyclotron Institute, Texas A&M University Advisor: Dr. Charles Folden III, Cyclotron Institute, Texas A&M University Introduction * Chemical properties of superheavy elements (Z > 108) are relatively unknown, with exception of element 112 * Preliminary research

  3. Trans Tech Green Power | Open Energy Information

    Open Energy Info (EERE)

    Trans Tech Green Power Jump to: navigation, search Name: Trans Tech Green Power Place: India Sector: Biomass Product: Plans to develop biomass projects in Rajasthan. References:...

  4. TA1 Room Layout with Newport Laser

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    SCALE: 12" X 12" N S E W 22.50 JUPITER LASER FACILITY TA1 ROOM TA1 CHAMBER WEST BEAM CABLE COVER VISAR VIDMAR C O N T R O L R A C K...

  5. Decontamination and Demolition at TA-21

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    TA-21 Demolition Decontamination and Demolition at TA-21 On December 1, 2009, LANL began full-scale demolition at TA-21, the Cold War-era complex of buildings that once housed plutonium production and historic, nonweapons research. August 1, 2013 Water sprayed during demolition to protect air quality Water sprayed during demolition to protect air quality The buildings at TA-21 were built as long ago as the 1940s, replacing Manhattan-era facilities and housing labs, offices, and production

  6. TA-55: LANL Plutonium-Processing Facilities

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Facilities » TA-55: LANL Plutonium-Processing Facilities TA-55: LANL Plutonium-Processing Facilities TA-55 supports a wide range of national security programs that involve stockpile stewardship, plutonium processing, nuclear materials stabilization, materials disposition, nuclear forensics, nuclear counter-terrorism, and nuclear energy. ...the only fully operational, full capability plutonium facility in the nation. National Security At the Los Alamos National Laboratory (LANL), virtually all

  7. WebTrans Update - August 31, 2015

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Notices Rates Standards of Conduct Tariff TF Web Based Training Notice: WebTrans Update Posted Date: 8312015 BPAT is deploying a minor change to Production webTrans in...

  8. WebTrans Update - September 9, 2015

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Notices Rates Standards of Conduct Tariff TF Web Based Training Notice: WebTrans Update Posted Date: 992015 BPAT is deploying a change to Production webTrans today...

  9. Decontamination and Demolition at TA-21

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    On December 1, 2009, LANL began full-scale demolition at TA-21, the Cold War-era complex ... labs, offices, and production facilities from the Manhattan Project and Cold War eras. ...

  10. Memo - Legacy Technical Area (TA)-55 Nitrate Salt Wastes at TA...

    Office of Environmental Management (EM)

    Plant on February 14, 2014, report in Attachment F. Bibliography and References, are available on various public websites. Memo - Legacy Technical Area (TA)-55 Nitrate Salt ...

  11. Trans India Acquisition Corporation | Open Energy Information

    Open Energy Info (EERE)

    India Acquisition Corporation Jump to: navigation, search Name: Trans-India Acquisition Corporation Place: Delaware Sector: Solar Product: Blank check company to be merged with...

  12. Hydrogen Transition (HyTRANS) Model

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    optimization of an objective function that reflects private costs and benefits. ... Platform, Requirements & Availability HyTRANS is a dynamic, non- linear optimization, ...

  13. TransWest Old | Open Energy Information

    Open Energy Info (EERE)

    Old Jump to: navigation, search NEPA Document Collection for: TransWest Old EIS NEPA name unknown General NEPA Document Info Environmental Analysis Type EIS Applicant Not Provided...

  14. IRAK4 Dimerization and Trans-Autophosphorylation Are Induced...

    Office of Scientific and Technical Information (OSTI)

    IRAK4 Dimerization and Trans-Autophosphorylation Are Induced by Myddosome Assembly Citation Details In-Document Search Title: IRAK4 Dimerization and Trans-Autophosphorylation Are ...

  15. NNSA to Start Moving TA-18 Nuclear Materials | National Nuclear...

    National Nuclear Security Administration (NNSA)

    Assembly Facility (DAF) at the Nevada Test Site in anticipation of shifting the TA-18 ... to move TA-18 operations to the Nevada Test Site," said NNSA Administrator Linton F. ...

  16. Oxygen Electroreduction on Nanoscale Pt/[TaOPO4/VC] and Pt/[Ta2O5...

    Office of Scientific and Technical Information (OSTI)

    Oxygen Electroreduction on Nanoscale PtTaOPO4VC and PtTa2O5VC in Alkaline Electrolyte Citation Details In-Document Search Title: Oxygen Electroreduction on Nanoscale Pt...

  17. Attachment B Visitor Tours at TA-53 TA53-FO-121-001B.4 Preparation Checklist for Visitor Tours at TA-53

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Attachment B Visitor Tours at TA-53 TA53-FO-121-001B.4 Preparation Checklist for Visitor Tours at TA-53 This checklist provides reminders of safety and security considerations in preparation and implementation of tours at TA-53. Tour Date: Purpose of Tour or Tour Title: Tour Host and Z#: State Time and Approximate Duration: Tour Type Check all that apply: Educational Outreach/Student Tour with Minors Large Group Tour Other Tour High Level or Distinguished Work Related Tour Preparation, Visitor

  18. TA-2 Water Boiler Reactor Decommissioning Project

    SciTech Connect (OSTI)

    Durbin, M.E.; Montoya, G.M.

    1991-06-01

    This final report addresses the Phase 2 decommissioning of the Water Boiler Reactor, biological shield, other components within the biological shield, and piping pits in the floor of the reactor building. External structures and underground piping associated with the gaseous effluent (stack) line from Technical Area 2 (TA-2) Water Boiler Reactor were removed in 1985--1986 as Phase 1 of reactor decommissioning. The cost of Phase 2 was approximately $623K. The decommissioning operation produced 173 m{sup 3} of low-level solid radioactive waste and 35 m{sup 3} of mixed waste. 15 refs., 25 figs., 3 tabs.

  19. CRAD, Configuration Management - Los Alamos National Laboratory TA 55 SST

    Office of Environmental Management (EM)

    Facility | Department of Energy Configuration Management - Los Alamos National Laboratory TA 55 SST Facility CRAD, Configuration Management - Los Alamos National Laboratory TA 55 SST Facility June 2005 A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for an assessment of the Configuration Management program at the Los Alamos National Laboratory, TA

  20. CRAD, Emergency Management - Los Alamos National Laboratory TA 55 SST

    Office of Environmental Management (EM)

    Facility | Department of Energy Emergency Management - Los Alamos National Laboratory TA 55 SST Facility CRAD, Emergency Management - Los Alamos National Laboratory TA 55 SST Facility June 2005 A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for an assessment of the Emergency Management program at the Los Alamos National Laboratory TA 55 SST

  1. EIS-0139: Trans-Alaska Gas System

    Broader source: Energy.gov [DOE]

    This EIS analyzes the Yukon Pacific Corporation's proposed construction of the Trans-Alaska Gas System (TAGS), a 796.5-mile long, 36-inch diameter pipeline to transport high-pressured natural gas between Prudhoe Bay and a tidewater terminal and liquefied natural gas plant near Anderson Bay, Alaska.

  2. New England Hydro-Trans Corp | Open Energy Information

    Open Energy Info (EERE)

    Hydro-Trans Corp Jump to: navigation, search Name: New England Hydro-Trans Corp Place: New Hampshire Phone Number: 1.800.661.3805 Website: www.transcanada.comindex.html Twitter:...

  3. New England Hydro-Tran Elec Co | Open Energy Information

    Open Energy Info (EERE)

    New England Hydro-Tran Elec Co Jump to: navigation, search Name: New England Hydro-Tran Elec Co Place: Massachusetts Phone Number: 860 729 9767 Website: www.nehydropower.com...

  4. EA-262 TransCanada Power Marketing Ltd | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    TransCanada Power Marketing Ltd EA-262 TransCanada Power Marketing Ltd Order authorizing TransCanada Power Marketing Ltd to export electric energy to Canada. EA-262 TransCanada ...

  5. Microstructural and weldability evaluation of 310TaN

    SciTech Connect (OSTI)

    Lundin, C.D.; Qiao, C.Y.P.; Swindeman, R.W.

    1996-08-01

    Excellent weldability and good microstructural stability of 310TaN, in terms of the formation and growth of secondary phases at elevated temperature, was revealed in this investigation. The interganular stress corrosion resistance of 310TaN is superior to modified 800H and 310HCbN evaluated previously due to the fact that TaC, TaN and Ta(C,N) particles are more stable compared to Nb-rich or Ti-rich carbides, nitrides and carbonitrides presented in the other advanced alloys. Using resistance spot welding technique for which extremely fast cooling is a characteristic, it was found that a very minor amount of gain boundary liquation takes place during welding thermal cycling. The limited grain boundary liquation is of the eutectic type i.e., a low tendency to weld HAZ hot cracking.

  6. Kah-nee-ta Pool & Spa Low Temperature Geothermal Facility | Open...

    Open Energy Info (EERE)

    Kah-nee-ta Pool & Spa Low Temperature Geothermal Facility Jump to: navigation, search Name Kah-nee-ta Pool & Spa Low Temperature Geothermal Facility Facility Kah-nee-ta Sector...

  7. CRAD, Training - Los Alamos National Laboratory TA 55 SST Facility |

    Office of Environmental Management (EM)

    Department of Energy Training - Los Alamos National Laboratory TA 55 SST Facility CRAD, Training - Los Alamos National Laboratory TA 55 SST Facility A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for an assessment of the Training Program at the Los Alamos National Laboratory TA 55 SST Facility. CRADs provide a recommended approach and the types

  8. Microsoft Word - tran_abstract.docx

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    using bis(2-ethylhexyl) phosphate K.A.Tran 1,2 , M.F. Volia 1,3 , E.E. Tereshatov 1 , and C.M. Folden 1 1 Cyclotron Institute, Texas A&M University, College Station, TX 77843 USA 2 Eastern Kentucky University, Richmond, KY 40475 USA 3 Department of Nuclear Engineering, Texas A&M University, College Station, TX 77843 USA The chemical properties of superheavy elements are relatively unknown due to their short half- lives and difficulty of production. In preparation for a future experiment

  9. TA-53 UNREVIEWED SAFETY ISSUE SCREENING AND DETERMINATION PROCESS

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AND DETERMINATION PROCESS TRAINING WORKSHEET CT-TA53-FRM-505-R00 102011 Page 1 of 3 LA-UR-12-10162 TRAINEE NAME: Z NUMBER: GROUP: PURPOSE AND SCOPE: This worksheet is used to...

  10. Coway International TechTrans Co Ltd | Open Energy Information

    Open Energy Info (EERE)

    company with experience in technology transfer in China, specialising in biotech, chemical, energy environment and CDM areas. References: Coway International TechTrans Co...

  11. Deseret Generation & Tran Coop (Colorado) | Open Energy Information

    Open Energy Info (EERE)

    Coop (Colorado) Jump to: navigation, search Name: Deseret Generation & Tran Coop Place: Colorado Website: www.deseretpower.com Outage Hotline: (801) 619-6500 References: EIA Form...

  12. EA-216-B TransAlta Energy Marketing (U.S) Inc | Department of...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    B TransAlta Energy Marketing (U.S) Inc EA-216-B TransAlta Energy Marketing (U.S) Inc Order authorizing TransAlta Energy Marketing (U.S) Inc to export electric energy to Canada. ...

  13. EA-262-B TransCanada Power Marketing Ltd | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    B TransCanada Power Marketing Ltd EA-262-B TransCanada Power Marketing Ltd Order authorizing TransCanada Power Marketing Ltd to export electric energy to Canada. EA-262-B ...

  14. EA-262-A TransCanada Power Marketing Ltd | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    A TransCanada Power Marketing Ltd EA-262-A TransCanada Power Marketing Ltd Order authorizing TransCanada Power Marketing Ltd to export electric energy to Canada. EA-262-A ...

  15. EA-216 TransAlta Energy Marketing (U.S) Inc | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    TransAlta Energy Marketing (U.S) Inc EA-216 TransAlta Energy Marketing (U.S) Inc Order authorizing TransAlta Energy Marketing (U.S) Inc to export electric energy to Canada. EA-216 ...

  16. EA-262-C TransCanada Power Marketing Ltd | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    C TransCanada Power Marketing Ltd EA-262-C TransCanada Power Marketing Ltd Order authorizing TransCanada Power Marketing Ltd to export electric energy to Canada. EA-262-C ...

  17. EA-216-C TransAlta Energy Marketing (U.S.)Inc. | Department of...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    -C TransAlta Energy Marketing (U.S.)Inc. EA-216-C TransAlta Energy Marketing (U.S.)Inc. Order authorizing TransAlta Energy Marketing (U.S.) Inc to export electric energy to Canada. ...

  18. Optical spectroscopy of the Weyl semimetal TaAs

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Xu, B.; Dai, Y. M.; Zhao, L. X.; Wang, K.; Yang, R.; Zhang, W.; Liu, J. Y.; Xiao, H.; Chen, G. F.; Taylor, A. J.; et al

    2016-03-24

    Here, we present a systematic study of both the temperature and frequency dependence of the optical response in TaAs, a material that has recently been realized to host the Weyl semimetal state. Our study reveals that the optical conductivity of TaAs features a narrow Drude response alongside a conspicuous linear dependence on frequency. The weight of the Drude peak decreases upon cooling, following a T2 temperature dependence, in good agreement with theoretical predictions. Two linear components with distinct slopes dominate the low-temperature optical conductivity. A comparison between our experimental results and theoretical calculations suggests that the linear conductivity below ~230more » cm–1 arises purely from interband transitions near the Weyl points, providing rich information about the Weyl semimetal state in TaAs.« less

  19. CRAD, Maintenance- Los Alamos National Laboratory TA 55 SST Facility

    Broader source: Energy.gov [DOE]

    A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for an assessment of the Maintenance program at the Los Alamos National Laboratory TA 55 SST Facility.

  20. Compositional depth profiling of TaCN thin films

    SciTech Connect (OSTI)

    Adelmann, Christoph; Conard, Thierry; Franquet, Alexis; Brijs, Bert; Munnik, Frans; Burgess, Simon; Witters, Thomas; Meersschaut, Johan; Kittl, Jorge A.; Vandervorst, Wilfried; Van Elshocht, Sven

    2012-07-15

    The composition profiling of thin TaCN films was studied. For the composition profile determination using x-ray photoemission spectrometry (XPS) in combination with Ar sputtering, preferential sputtering effects of N with respect to Ta and C were found to lead to inaccurate elemental concentrations. Sputter yield calculations for the given experimental conditions allowed for the correction of a part of the error, leading to fair accuracy by reference-free measurements. Further improvement of the accuracy was demonstrated by the calibration of the XPS compositions against elastic recoil detection analysis (ERDA) results. For Auger electron spectrometry (AES) in combination with Ar sputtering, accurate results required the calibration against ERDA. Both XPS and AES allowed for a reliable and accurate determination of the compositional profiles of TaCN-based thin films after calibration. Time-of-flight secondary-ion mass spectrometry was also used to assess the composition of the TaCN films. However, the analysis was hampered by large matrix effects due to small unintentional oxygen contents in the films. Energy-dispersive x-ray spectrometry is also discussed, and it is shown that an accurate reference-free measurement of the average film concentration can be achieved.

  1. CRAD, Management- Los Alamos National Laboratory TA 55 SST Facility

    Broader source: Energy.gov [DOE]

    A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for an assessment of the Management at the Los Alamos National Laboratory TA 55 SST Facility.

  2. TransCanada Power Mktg Ltd (Connecticut) | Open Energy Information

    Open Energy Info (EERE)

    Connecticut Phone Number: 1.800.661.3805 Website: www.transcanada.compowermarke Twitter: @TransCanada Outage Hotline: 1-800-447-8066 References: EIA Form EIA-861 Final Data...

  3. TransCanada Energy Marketing ULC | Open Energy Information

    Open Energy Info (EERE)

    Marketing ULC Jump to: navigation, search Name: TransCanada Energy Marketing ULC Place: California References: EIA Form EIA-861 Final Data File for 2010 - File1a1 EIA Form 861...

  4. Anomalous electronic structure and magnetoresistance in TaAs2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Luo, Yongkang; McDonald, R. D.; Rosa, P. F. S.; Scott, B.; Wakeham, N.; Ghimire, N. J.; Bauer, E. D.; Thompson, J. D.; Ronning, F.

    2016-06-07

    We report that the change in resistance of a material in a magnetic field reflects its electronic state. In metals with weakly- or non-interacting electrons, the resistance typically increases upon the application of a magnetic field. In contrast, negative magnetoresistance may appear under some circumstances, e.g., in metals with anisotropic Fermi surfaces or with spin-disorder scattering and semimetals with Dirac or Weyl electronic structures. Here we show that the non-magnetic semimetal TaAs2 possesses a very large negative magnetoresistance, with an unknown scattering mechanism. In conclusion, density functional calculations find that TaAs2 is a new topological semimetal [Z2 invariant (0;111)] withoutmore » Dirac dispersion, demonstrating that a negative magnetoresistance in non-magnetic semimetals cannot be attributed uniquely to the Adler-Bell-Jackiw chiral anomaly of bulk Dirac/Weyl fermions.« less

  5. Technical Area V (TA-V) transformation project close-out report.

    SciTech Connect (OSTI)

    Not Available

    2010-07-01

    Sandia National Laboratories (SNL) Technical Area V (TA-V) has provided unique nuclear experimental environments for decades. The technologies tested in TA-V facilities have furthered the United States Nuclear Weapons program and has contributed to the national energy and homeland security mission. The importance of TA-V working efficiently to produce an attractive and effective platform for experiments should not be underestimated. Throughout its brief history, TA-V has evolved to address multiple and diverse sets of requirements. These requirements evolved over many years; however, the requirements had not been managed nor communicated comprehensively or effectively. A series of programmatic findings over several years of external audits was evidence of this downfall. Today, these same requirements flow down through a new TA-V management system that produces consistently applied and reproducible approaches to work practices. In 2008, the TA-V department managers assessed the state of TA-V services and work activities to understand how to improve customer interfaces, stakeholders perceptions, and workforce efficiencies. The TA-V management team initiated the TA-V Transformation Project after they deemed the pre-June 2008 operational model to be ineffective in managing work and in providing integrated, continuous improvement to TA-V processes. This report summarizes the TA-V Transformation Project goals, activities, and accomplishments.

  6. Facility Representative, Technical Area (TA-55) Plutonium Facility, Los

    National Nuclear Security Administration (NNSA)

    Alamos Site Office | National Nuclear Security Administration | (NNSA) Facility Representative, Technical Area (TA-55) Plutonium Facility, Los Alamos Site Office John Krepps John Krepps June 2010 U.S. Department of Energy Facility Representative of the Year John Krepps, a facility representative for the National Nuclear Security Administration's (NNSA) Los Alamos Site Office, received the Department of Energy's top award for oversight of nuclear and non-nuclear facilities. Krepps, a Los

  7. Issues for reuse of gloveboxes at LANL TA-55

    SciTech Connect (OSTI)

    Cadwallader, L.C.; Pinson, P.A.; Miller, C.F.

    1998-08-01

    This report is a summary of issues that face plutonium glovebox designers and users at the Los Alamos National Laboratory (LANL) Technical Area 55 (TA-55). Characterizing the issues is a step in the task of enhancing the next generation glovebox design to minimize waste streams while providing the other design functions. This report gives an initial assessment of eight important design and operation issues that can benefit from waste minimization.

  8. Application to export electric energy OE docket No. EA-262-C TransCanada

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Power Marketing Ltd | Department of Energy docket No. EA-262-C TransCanada Power Marketing Ltd Application to export electric energy OE docket No. EA-262-C TransCanada Power Marketing Ltd Application from TransCanada Power Marketing Ltd to export electric energy to Canada. Application to export electric energy OE docket No. EA-262-C TransCanada Power Marketing Ltd (1.02 MB) More Documents & Publications EA-262-C TransCanada Power Marketing Ltd EA-262-A TransCanada Power Marketing Ltd

  9. TaC Studios New Construction Test House

    SciTech Connect (OSTI)

    Butler, T.; Curtis, O.; Kim, E.; Roberts, S.; Stephenson, R.

    2013-03-01

    As part of the NAHB Research Center Industry Partnership, Southface partnered with TaC Studios, an Atlanta based architecture firm specializing in residential and light commercial design, on the construction of a new test home in Atlanta, GA in the mixed humid climate zone. This home will serve as a model home for the builder partner and addresses Building America energy savings targets through the planning and implementation of a design package will serve as a basis of design for the builder partner's future homes. As a BA test house, this home will be evaluated to detail whole house energy use, end use loads, and HVAC and hot water efficiency.

  10. TaC Studios New Construction Test House

    SciTech Connect (OSTI)

    Butler, T.; Curtis, O.; Kim, E.; Roberts, S.; Stephenson, R.

    2013-03-01

    As part of the NAHB Research Center Industry Partnership, Southface partnered with TaC Studios, an Atlanta based architecture firm specializing in residential and light commercial design, on the construction of a new test home in Atlanta, GA, in the mixed humid climate zone. This home will serve as a model home for the builder partner and addresses Building America energy savings targets through the planning and implementation of a design package will serve as a basis of design for the builder partner’s future homes. As a BA test house, this home will be evaluated to detail whole house energy use, end use loads, and HVAC and hot water efficiency.

  11. Nucleation of fcc Ta when heating thin films

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Janish, Matthew T.; Mook, William M.; Carter, C. Barry

    2014-10-25

    Thin tantalum films have been studied during in-situ heating in a transmission electron microscope. Diffraction patterns from the as-deposited films were typical of amorphous materials. Crystalline grains were observed to form when the specimen was annealed in-situ at 450°C. Particular attention was addressed to the formation and growth of grains with the face-centered cubic (fcc) crystal structure. As a result, these observations are discussed in relation to prior work on the formation of fcc Ta by deformation and during thin film deposition.

  12. Magnetotransport measurements of current induced effective fields in Ta/CoFeB/MgO

    SciTech Connect (OSTI)

    Zhang, Chaoliang; Yamanouchi, Michihiko Ikeda, Shoji; Center for Spintronics Integrated Systems, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 ; Sato, Hideo; Fukami, Shunsuke; Matsukura, Fumihiro; Ohno, Hideo; Center for Spintronics Integrated Systems, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577; WPI Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577

    2013-12-23

    We evaluate current-induced effective magnetic fields in perpendicularly magnetized Ta/CoFeB/MgO structures from the external magnetic field angle dependence of the Hall resistance. We confirm the presence of two components of effective fields. The dependence of their magnitudes on Ta thickness implies that both components are related to the spin current in Ta layer generated by the spin Hall effect.

  13. EA-216-D TransAlta Energy Marketing (U.S.) Inc. | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    D TransAlta Energy Marketing (U.S.) Inc. EA-216-D TransAlta Energy Marketing (U.S.) Inc. Order from TEMUS to export electric energy to Canada. EA-216-D TEMUS CN.pdf (762.11 KB) More Documents & Publications Application to Export Electric Energy OE Docket No. EA-216-D TransAlta Energy Marketing (U.S.) Inc. EA-216-C TransAlta Energy Marketing (U.S.)Inc

  14. Magnetization reversal induced by in-plane current in Ta/CoFeB...

    Office of Scientific and Technical Information (OSTI)

    current are accordance with those for magnetization reversal by spin transfer torque originated from the spin Hall effect in the Ta layer. Authors: Zhang, C. 1 ;...

  15. Technical Area (TA)-54 Area G Nitrate-Salt Waste Container Response...

    Broader source: Energy.gov (indexed) [DOE]

    Pilot Plant on February 14, 2014, report in Attachment F. Bibliography and References, are available on various public websites. Technical Area (TA)-54 Area G Nitrate-Salt ...

  16. Geology of the Western Part of Los Alamos National Laboratory (TA-3 to TA-16), Rio Grande Rift, New Mexico

    SciTech Connect (OSTI)

    C.J.Lewis; A.Lavine; S.L.Reneau; J.N.Gardner; R.Channell; C.W.Criswell

    2002-12-01

    We present data that elucidate the stratigraphy, geomorphology, and structure in the western part of Los Alamos National Laboratory between Technical Areas 3 and 16 (TA-3 and TA-16). Data include those gathered by geologic mapping of surficial, post-Bandelier Tuff strata, conventional and high-precision geologic mapping and geochemical analysis of cooling units within the Bandelier Tuff, logging of boreholes and a gas pipeline trench, and structural analysis using profiles, cross sections, structure contour maps, and stereographic projections. This work contributes to an improved understanding of the paleoseismic and geomorphic history of the area, which will aid in future seismic hazard evaluations and other investigations. The study area lies at the base of the main, 120-m (400-ft) high escarpment formed by the Pajarito fault, an active fault of the Rio Grande rift that bounds Los Alamos National Laboratory on the west. Subsidiary fracturing, faulting, and folding associated with the Pajarito fault zone extends at least 1,500 m (5,000 ft) to the east of the main Pajarito fault escarpment. Stratigraphic units in the study area include upper units of the Tshirege Member of the early Pleistocene Bandelier Tuff, early Pleistocene alluvial fan deposits that predate incision of canyons on this part of the Pajarito Plateau, and younger Pleistocene and Holocene alluvium and colluvium that postdate drainage incision. We discriminate four sets of structures in the area between TA-3 and TA-16: (a) north-striking faults and folds that mark the main zone of deformation, including a graben in the central part of the study area; (b) north-northwest-striking fractures and rare faults that bound the eastern side of the principal zone of deformation and may be the surface expression of deep-seated faulting; (c) rare northeast-striking structures near the northern limit of the area associated with the southern end of the Rendija Canyon fault; and (d) several small east

  17. Application to Export Electric Energy OE Docket No. EA-216-D TransAlta

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Energy Marketing (U.S.) Inc. | Department of Energy Export Electric Energy OE Docket No. EA-216-D TransAlta Energy Marketing (U.S.) Inc. Application to Export Electric Energy OE Docket No. EA-216-D TransAlta Energy Marketing (U.S.) Inc. Application from TEMUS to export electric energy to Canada. EA-216-D TransAlta Energy Mktg (CN).pdf (449.47 KB) More Documents & Publications EA-216-D TransAlta Energy Marketing (U.S.) Inc. EA-216-C TransAlta Energy Marketing (U.S.)Inc. Application to

  18. Trans ecuadorian pipeline; Mountainous pipeline restoration a logistical masterpiece

    SciTech Connect (OSTI)

    Hamilton, L. )

    1988-06-01

    The Trans Ecuadorian Pipeline pumped approximately 300,000 b/d of crude from fields in eastern Ecuador to an export terminal and refinery at Esmeraldas on the Pacific coast. The devastation resulting from an earthquake cut off the main portion of export income as well as domestic fuel supplies and propane gas. Approximately 25 km of the pipeline was destroyed. This article details how the pipeline was reconstructed, including both the construction of a temporary line and of permanent facilities.

  19. Suboxide/subnitride formation on Ta masks during magnetic material etching by reactive plasmas

    SciTech Connect (OSTI)

    Li, Hu; Muraki, Yu; Karahashi, Kazuhiro; Hamaguchi, Satoshi

    2015-07-15

    Etching characteristics of tantalum (Ta) masks used in magnetoresistive random-access memory etching processes by carbon monoxide and ammonium (CO/NH{sub 3}) or methanol (CH{sub 3}OH) plasmas have been examined by mass-selected ion beam experiments with in-situ surface analyses. It has been suggested in earlier studies that etching of magnetic materials, i.e., Fe, Ni, Co, and their alloys, by such plasmas is mostly due to physical sputtering and etch selectivity of the process arises from etch resistance (i.e., low-sputtering yield) of the hard mask materials such as Ta. In this study, it is shown that, during Ta etching by energetic CO{sup +} or N{sup +} ions, suboxides or subnitrides are formed on the Ta surface, which reduces the apparent sputtering yield of Ta. It is also shown that the sputtering yield of Ta by energetic CO{sup +} or N{sup +} ions has a strong dependence on the angle of ion incidence, which suggests a correlation between the sputtering yield and the oxidation states of Ta in the suboxide or subnitride; the higher the oxidation state of Ta, the lower is the sputtering yield. These data account for the observed etch selectivity by CO/NH{sub 3} and CH{sub 3}OH plasmas.

  20. Preparation and performances of nanosized Ta{sub 2}O{sub 5} powder photocatalyst

    SciTech Connect (OSTI)

    Zhu Yongfa . E-mail: zhuyf@chem.tsinghua.edu.cn; Yu Fang; Man, Yi; Tian, Qingyong; He Yu; Wu Nianzu

    2005-01-15

    Nanosized-Ta{sub 2}O{sub 5} powder photocatalyst was successfully synthesized by using sol-gel method via TaCl{sub 5} butanol solution as a precursor. Ta{sub 2}O{sub 5} species can be formed under 500 deg. C via the decomposition of the precursor. The crystalline phase of Ta{sub 2}O{sub 5} powder photocatalyst can be obtained after being calcined above 600 deg. C for 4h. The crystal size and particle size of Ta{sub 2}O{sub 5} powder photocatalyst was about 50nm. A good photocatalytic performance for the degradation of gaseous formaldehyde was obtained for the nanosized-Ta{sub 2}O{sub 5} powder. The Ta{sub 2}O{sub 5} powder formed at 700 deg. C for 4h and at 650 deg. C for 12h showed the best performance. The calcination temperature and time play an important role in the crystallization and photocatalytical performance of nanosized-Ta{sub 2}O{sub 5} powder.

  1. Electron Cloud at Low Emittance in CesrTA

    SciTech Connect (OSTI)

    Palmer, Mark; Alexander, James; Billing, Michael; Calvey, Joseph; Conolly, Christopher; Crittenden, James; Dobbins, John; Dugan, Gerald; Eggert, Nicholas; Fontes, Ernest; Forster, Michael; Gallagher, Richard; Gray, Steven; Greenwald, Shlomo; Hartill, Donald; Hopkins, Walter; Kreinick, David; Kreis, Benjamin; Leong, Zhidong; Li, Yulin; Liu, Xianghong; /more authors..

    2012-07-06

    The Cornell Electron Storage Ring (CESR) has been reconfigured as a test accelerator (CesrTA) for a program of electron cloud (EC) research at ultra low emittance. The instrumentation in the ring has been upgraded with local diagnostics for measurement of cloud density and with improved beam diagnostics for the characterization of both the low emittance performance and the beam dynamics of high intensity bunch trains interacting with the cloud. A range of EC mitigation methods have been deployed and tested and their effectiveness is discussed. Measurements of the electron cloud's effect on the beam under a range of conditions are discussed along with the simulations being used to quantitatively understand these results.

  2. Chemical Concentrations in Field Mice from Open-Detonation Firing Sites TA-36 Minie and TA-39 Point 6 at Los Alamos National Laboratory

    SciTech Connect (OSTI)

    Fresquez, Philip R.

    2011-01-01

    Field mice (mostly Peromyscus spp.) were collected at two open-detonation (high explosive) firing sites - Minie at Technical Area (TA) 36 and Point 6 at TA-39 - at Los Alamos National Laboratory in August of 2010 and in February of 2011 for chemical analysis. Samples of whole body field mice from both sites were analyzed for target analyte list elements (mostly metals), dioxin/furans, polychlorinated biphenyl congeners, high explosives, and perchlorate. In addition, uranium isotopes were analyzed in a composite sample collected from TA-36 Minie. In general, all constituents, with the exception of lead at TA-39 Point 6, in whole body field mice samples collected from these two open-detonation firing sites were either not detected or they were detected below regional statistical reference levels (99% confidence level), biota dose screening levels, and/or soil ecological chemical screening levels. The amount of lead in field mice tissue collected from TA-39 Point 6 was higher than regional background, and some lead levels in the soil were higher than the ecological screening level for the field mouse; however, these levels are not expected to affect the viability of the populations over the site as a whole.

  3. Analyzing the Impacts of Policies and Technological Change Using HyTrans |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy Analyzing the Impacts of Policies and Technological Change Using HyTrans Analyzing the Impacts of Policies and Technological Change Using HyTrans Presentation by ORNL's David Greene at the 2010 - 2025 Scenario Analysis for Hydrogen Fuel Cell Vehicles and Infrastructure Meeting on August 9 - 10, 2006 in Washington, D.C. greene_scenarios_hytrans.pdf (365.6 KB) More Documents & Publications Integrated Market Modeling of Hydrogen Transition Scenarios with HyTrans Cost

  4. Influence of shockwave obliquity on deformation twin formation in Ta

    SciTech Connect (OSTI)

    Gray, George T., III; Livescu, V; Cerreta, E K; Mason, T A; Maudlin, P J; Bingert, J F

    2009-02-18

    Energetic loading subjects a material to a 'Taylor wave' (triangular wave) loading profile that experiences an evolving balance of hydrostatic (spherical) and deviatoric stresses. While much has been learned over the past five decades concerning the propensity of deformation twinning in samples shockloaded using 'square-topped' profiles as a function of peak stress, achieved most commonly via flyer plate loading, less is known concerning twinning propensity during non-I-dimensional sweeping detonation wave loading. Systematic small-scale energetically-driven shock loading experiments were conducted on Ta samples shock loaded with PEFN that was edge detonated. Deformation twinning was quantified in post-mortem samples as a function of detonation geometry and radial position. In the edge detonated loading geometry examined in this paper, the average volume fraction of deformation twins was observed to drastically increase with increasing shock obliquity. The results of this study are discussed in light of the formation mechanisms of deformation twins, previous literature studies of twinning in shocked materials, and modeling of the effects of shock obliquity on the evolution of the stress tensor during shock loading.

  5. Precision dilatometry of Nb, Ta, and Lu tritides

    SciTech Connect (OSTI)

    Schober, T.; Dieker, C.; Lasser, R.; Trinkaus, H.

    1989-07-15

    Applying buoyancy dilatometry at room temperature toNbT/sub 0.0253/ and strain-gauge dilatometry at roomtemperature and 78 K to TaT/sub 0.0744/ andLuT/sub 0.15/, respectively, we have measured the swelling ofthese tritides due to the transmutation of T to /sup 3/He in the firsttwo years after T charging. For all three tritides almost linear swelling isfound, indicating approximately constant /sup 3/He densities inbubbles. The corresponding values for the volume requirement of a/sup 3/He atom in a bubble are around 8 A/sup 3/.Associated pressure values are derived with the aid of an equation of state for/sup 3/He adapted to recent high-pressure x-ray-diffractionmeasurements on solid /sup 4/He. With increasing /sup 3/Heconcentration the pressure seems to converge to about 0.2 of the shear modulusof the metal, in accordance with recent theoretical results concerning thethreshold pressure for dislocation-loop punching by bubbles.

  6. Trans-Americas leads the way into municipal textile recycling

    SciTech Connect (OSTI)

    Ridgley, H.

    1998-08-01

    Most textile waste in the US still goes to the landfill--an estimated 6.6 million tons each year. But thanks to the efforts of textile recycles--such as Trans-Americas Textile Recycling CO. (Brooklyn, NY)--another 1.25 million tons gets salvaged for reuse overseas or as a feedstock for the wiping and fiber industries, according to the Council for Textile Recycling. In an era where global population levels are increasing the demand for textile waste from the Western world and municipalities are struggling to reach their waste diversion goals, boosting textile recovery rates makes sense. And it`s a waste that can be easily incorporated into existing municipal curbside or drop-off recycling programs. Since 1942, when the company first opened its doors in Brooklyn, NY, it purchased textile discards from charities. While those discards still make up the majority of Trans-Americas` supply, in the last two years, the company also began purchasing post-consumer material from municipalities. Textiles are definitely going to be an increasingly important part of recycling, as states look to meet their mandates.

  7. EP-AREAG-PLAN-1248, R.0 TA-54 Area G Nitrate-Salt Waste Container...

    Office of Environmental Management (EM)

    EP-AREAG-PLAN-1248, R.0 TA-54 Area G Nitrate-Salt Waste Container Response Instructions Effective Date: 5282014 The Responsible Manager has determined that the following...

  8. Preparation of W-Ta thin-film thermocouple on diamond anvil cell...

    Office of Scientific and Technical Information (OSTI)

    Preparation of W-Ta thin-film thermocouple on diamond anvil cell for in-situ temperature measurement under high pressure Citation Details In-Document Search Title: Preparation of W...

  9. [Inspection of gas cylinders in storage at TA-54, Area L]. Volume 2, Final report

    SciTech Connect (OSTI)

    1994-06-23

    ERC sampled, analyzed, and rcontainerized when necessary gas cylinders containing various chemicals in storage at LANL TA-54 Area L. This report summarizes the operation. This is Volume 2 of five volumes.

  10. Atmospheric Dispersion and Consequence Analysis at Sandia's TA-V Nuclear Facilities

    Office of Environmental Management (EM)

    Atmospheric Dispersion and Consequence Analysis at Sandia's TA-V Nuclear Facilities Jim Dahl Manager, Nuclear Safety Analysis Sandia National Laboratories Office: 505-284-9067 Email: jjdahl@sandia.gov SAND2012-4478P Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. 2 Dispersion and Consequence Analysis at Sandia's TA-V Topics: * Site

  11. Technical Area (TA)-54 Area G Nitrate-Salt Waste Container Response

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Instructions | Department of Energy Technical Area (TA)-54 Area G Nitrate-Salt Waste Container Response Instructions Technical Area (TA)-54 Area G Nitrate-Salt Waste Container Response Instructions This document was used to determine facts and conditions during the Department of Energy Accident Investigation Board's investigation into the radiological release event at the Waste Isolation Pilot Plant. Additional documents referenced and listed in the Phase 2 Radiological Release Event at the

  12. Visible Light Assisted Photocatalytic Hydrogen Generation by Ta2O5/Bi2O3, TaON/Bi2O3, and Ta3N5/Bi2O3 Composites

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Adhikari, Shiba; Hood, Zachary D.; More, Karren Leslie; Ivanov, Ilia N.; Zhang, Lifeng; Gross, Michael; Lachgar, Abdou

    2015-06-15

    Composites comprised of two semiconducting materials with suitable band gaps and band positions have been reported to be effective at enhancing photocatalytic activity in the visible light region of the electromagnetic spectrum. Here, we report the synthesis, complete structural and physical characterizations, and photocatalytic performance of a series of semiconducting oxide composites. UV light active tantalum oxide (Ta2O5) and visible light active tantalum oxynitride (TaON) and tantalum nitride (Ta3N5) were synthesized, and their composites with Bi2O3 were prepared in situ using benzyl alcohol as solvent. The composite prepared using equimolar amounts of Bi2O3 and Ta2O5 leads to the formation ofmore » the ternary oxide, bismuth tantalate (BiTaO4) upon calcination at 1000 °C. The composites and single phase bismuth tantalate formed were characterized by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET) surface area measurement, scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–Vis diffuse reflectance spectroscopy, and photoluminescence. The photocatalytic activities of the catalysts were evaluated for generation of hydrogen using aqueous methanol solution under visible light irradiation (λ ≥ 420 nm). The results show that as-prepared composite photocatalysts extend the light absorption range and restrict photogenerated charge-carrier recombination, resulting in enhanced photocatalytic activity compared to individual phases. The mechanism for the enhanced photocatalytic activity for the heterostructured composites is elucidated based on observed activity, band positions calculations, and photoluminescence data.« less

  13. Growth of single crystalline TaON on yttria-stabilized zirconia (YSZ)

    SciTech Connect (OSTI)

    Tao, Junguang Chai, J.W.; Wong, L.M.; Zhang, Z.; Pan, J.S.; Wang, S.J.

    2013-08-15

    Owing to its high stability in aqueous solution and high quantum efficiency, tantalum based oxyntride (TaON) has attracted increasing attentions for application as visible light photocatalyst. However, despite the recent progress in photocatalytic studies, its bulk charge transport mechanisms are yet to be discovered because of the lack of single crystal sample. In this paper, high quality single crystalline TaON(100) thin film was prepared on cubic YSZ(100) surface by reactive RF magnetron sputtering to avail the understandings of charge transport mechanism so as to improve the device efficiency. The stoichiometry, crystal phase and structure were examined in situ by x-ray photoelectron spectroscopy (XPS) and ex situ by x-ray diffraction (XRD) and transmission electron microscopy (TEM). The TaON film crystallizes in monoclinic ?-phase with its [010]/[001] directions aligned to those of the substrate. The small band gap of 2.5 eV as well as the high structure perfection suggests better performance for visible light water splitting. The method can be used to prepare other surface orientations to elucidate fundamental surface structure dependent photoactivities. - Graphical abstract: Structure of single crystalline ?-TaON and its diffraction pole figure. Highlights: High quality single crystal TaON(100) thin film were grown on YSZ(100) surface. ?-phase monoclinic TaON film is formed. Its [010]/[001] directions are aligned to those of the substrate. The small band gap and structure perfection suggest visible light photo-activity.

  14. The benzene metabolite trans,trans-muconaldehyde blocks gap junction intercellular communication by cross-linking connexin43

    SciTech Connect (OSTI)

    Rivedal, Edgar Leithe, Edward

    2008-11-01

    Benzene is used at large volumes in many different human activities. Hematotoxicity and cancer-causation as a result of benzene exposure was recognized many years ago, but the mechanisms involved remain unclear. Aberrant regulation of gap junction intercellular communication (GJIC) has been linked to both cancer induction and interference with normal hematopoietic development. We have previously suggested that inhibition of GJIC may play a role in benzene toxicity since benzene metabolites were found to block GJIC, the ring-opened trans,trans-muconaldehyde (MUC) being the most potent metabolite. In the present work we have studied the molecular mechanisms underlying the MUC-induced inhibition of gap junctional communication. We show that MUC induces cross-linking of the gap junction protein connexin43 and that this is likely to be responsible for the induced inhibition of GJIC, as well as the loss of connexin43 observed in Western blots. We also show that glutaraldehyde possesses similar effects as MUC, and we compare the effects to that of formaldehyde. The fact that glutaraldehyde and formaldehyde have been associated with induction of leukemia as well as disturbance of hematopoiesis, strengthens the possible link between the effect of MUC on gap junctions, and the toxic effects of benzene.

  15. Kinetics of trans-cis isomerization in azobenzene dimers at an air-water interface

    SciTech Connect (OSTI)

    Kumar, Bharat; Suresh, K. A.

    2009-08-15

    We have studied the kinetics of trans to cis isomerization under the illumination of ultraviolet light, in the Langmuir monolayer of mesogenic azobenzene dimer, bis-[5-(4{sup '}-n-dodecyloxy benzoyloxy)-2-(4{sup ''}-methylphenylazo)phenyl] adipate, at an air-water interface. We find that the trans to cis isomerization reaction of the molecules in the monolayer shows deviation from the first-order kinetics unlike those reported on Langmuir monolayers of azobenzene molecules. We attribute the deviation from first-order kinetics to the simultaneous photoisomerization of trans isomers to form cis isomers and the reverse thermal isomerization of cis isomers to form trans isomers. Our analysis of the rate of change of mole fraction of trans isomers to form cis isomers indicates a first-order kinetics for trans to cis photoisomerization reaction and a second-order kinetics for cis to trans thermal isomerization reaction. This second-order kinetics mechanism is similar to the Lindemann-Hinshelwood mechanism for the unimolecular reactions at low concentration of reactants. The formation of the activated cis isomer by collisions is a slow process as compared to the decay of the activated cis isomer to trans isomer in the liquid expanded phase. This results in the second-order kinetics for the thermal isomerization of cis isomers.

  16. Trans beta substituted chlorins and methods of making and using the same

    DOE Patents [OSTI]

    Lindsey, Jonathan S.; Balasubramanian, Thiagarajan

    2003-05-06

    Trans beta substituted chlorins and methods of making the same are disclosed, along with polymers formed from or containing such trans beta substituted chlorins as one or more monomeric units therein, light harvesting rods formed from such polymers, and electrodes carrying such polymers.

  17. A note on trans-Planckian tail effects

    SciTech Connect (OSTI)

    Graef, L.L.; Brandenberger, R.

    2015-09-09

    We study the proposal by Mersini et al. http://dx.doi.org/10.1103/PhysRevD.64.043508 that the observed dark energy might be explained by the back-reaction of the set of tail modes in a theory with a dispersion relation in which the mode frequency decays exponentially in the trans-Planckian regime. The matter tail modes are frozen out, however they induce metric fluctuations. The energy-momentum tensor with which the tail modes effect the background geometry obtains contributions from both metric and matter fluctuations. We calculate the equation of state induced by the tail modes taking into account the gravitational contribution. We find that, in contrast to the case of frozen super-Hubble cosmological fluctuations, in this case the matter perturbations dominate, and they yield an equation of state which to leading order takes the form of a positive cosmological constant.

  18. Bixbyite- and anatase-type phases in the system Sc-Ta-O-N

    SciTech Connect (OSTI)

    Stork, A.; Schilling, H.; Wessel, C.; Wolff, H.; Boerger, A.; Baehtz, C.; Becker, K.-D.; Dronskowski, R.; Lerch, M.

    2010-09-15

    The aim of our study was to modify the basis compound ss-TaON, which crystallizes in the monoclinic baddeleyite-type, by incorporation of appropriate dopant ions, in order to obtain anion-deficient cubic fluorite-type phases, which are of interest as solids with mobile nitrogen ions. For this purpose, scandium-doped tantalum oxide nitrides were prepared by ammonolysis of amorphous oxide precursors. An unexpected variety of phases with different structural features was observed: bixbyite-type phases of general composition Sc{sub x}Ta{sub 1-x}(O,N){sub y} with 0.33{<=}x{<=}1 and 1.7{<=}y{<=}1.9, yellow colored metastable anatase-type phases such as Sc{sub 0.1}Ta{sub 0.9}O{sub 1.2}N{sub 0.8} or Sc{sub 0.15}Ta{sub 0.85}O{sub 1.3}N{sub 0.7} and, additionally, anosovite-type phases Sc{sub x}Ta{sub 3-x}O{sub 2x}N{sub 5-2x} with 0{<=}x{<=}1.05. Selected phases were investigated by UV/vis spectroscopy. Anatase- and anosovite-type compounds show brilliant colors. In the anatase-type phase, a possible anion ordering was examined by theoretical methods. Additionally, energy calculations on phase stability were performed for Sc{sub x}Ta{sub 1-x}O{sub 1+2x}N{sub 1-2x} in the baddeleyite, rutile, and anatase structure types with varying amounts of dopants. - Graphical abstract: New anatase- and bixbyite-type phases obtained as single-phase samples in the system Sc-Ta-O-N.

  19. Trans-Atlantic Workshop on Rare Earth Elements and Other Critical Materials for a Clean Energy Future

    Office of Energy Efficiency and Renewable Energy (EERE)

    Trans-Atlantic Workshop on Rare Earth Elements and Other Critical Materials for a Clean Energy Future

  20. Effects of annealing on antiwear and antibacteria behaviors of TaN-Cu nanocomposite thin films

    SciTech Connect (OSTI)

    Hsieh, J. H.; Cheng, M. K.; Chang, Y. K.; Li, C.; Chang, C. L.; Liu, P. C.

    2008-07-15

    TaN-Cu nanocomposite films were deposited by reactive cosputtering on Si and tool steel substrates. The films were then annealed using rapid thermal annealing (RTA) at 400 deg. C for 2, 4, and 8 min, respectively, to induce the nucleation and growth of Cu particles in TaN matrix and on film surface. Field emission scanning electron microscopy was applied to characterize Cu nanoparticles emerged on the surface of TaN-Cu thin films. The effects of annealing on the antiwear and antibacterial properties of these films were studied. The results reveal that annealing by RTA can cause Cu nanoparticles to form on the TaN surface. Consequently, the tribological behaviors, as well as the antibacterial behavior may vary depending on particle size, particle distribution, and total exposed Cu amount. For the samples with large Cu particles, the reduction of averaged friction and wear rate is obvious. Apparently, it is due to the smeared Cu particles adhered onto the wear tracks. This Cu layer may act as a solid lubricant. From the antibacterial testing results, it is found that both Cu particle size and total exposed Cu amount are critical in making short-term antibacterial effect. Overall, all the annealed TaN-Cu samples can reach >99% antibacterial efficiency in 24 h, with respect to uncoated Si substrate.

  1. Precessional magnetization induced spin current from CoFeB into Ta

    SciTech Connect (OSTI)

    Jamali, Mahdi; Klemm, Angeline; Wang, Jian-Ping

    2013-12-16

    The spin dynamics at the interface between the CoFeB and Ta layer has been studied using spin pumping and spin wave characterizations. The spin pumping driven by the ferromagnetic resonance in the CoFeB layer injects a spin current into Ta layer which results in an electromotive force across the Ta layer due to the inverse spin Hall effect. Upon changing the polarity of the bias magnetic field, the polarity of the output voltage inverts and the output voltage increases linearly in respect to the microwave signal power which are consistent with the spin pumping characteristics. The effect of the in-plane magnetization angle on the output voltage has been studied. Furthermore, it is found that the frequency spectrum of the spin Hall voltage is modified by the annealing temperature and the full width at half maximum of the spin pumping increases by more than 40% with the increase of the annealing temperature from 200 °C to 300 °C. The spin Hall angle at the Ta-CoFeB interface is determined to be 0.014, and the damping constant of the CoFeB increases from 0.006 in pure CoFeB to 0.015 in Ta/CoFeB film.

  2. Application to export electric energy OE Docket No. EA-216-C TransAlta

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Energy Marketing (U.S) Inc: Federal Register Notice Volume 76, No. 14 - Jan. 21, 2011 | Department of Energy export electric energy OE Docket No. EA-216-C TransAlta Energy Marketing (U.S) Inc: Federal Register Notice Volume 76, No. 14 - Jan. 21, 2011 Application to export electric energy OE Docket No. EA-216-C TransAlta Energy Marketing (U.S) Inc: Federal Register Notice Volume 76, No. 14 - Jan. 21, 2011 Application from TransAlta Energy Marketing (U.S) Inc to export electric energy to

  3. Crystal structures and phase transitions in Ba{sub 2}HoTaO{sub 6}

    SciTech Connect (OSTI)

    Kennedy, Brendan J. Saines, Paul J.; Kubota, Yoshiki; Minakata, Chiharu; Hano, Hiroko; Kato, Kenichi; Takata, Masaki

    2007-11-06

    The structure of the cation-ordered double perovskite Ba{sub 2}HoTaO{sub 6} was examined using synchrotron X-ray powder diffraction at fine temperature intervals over the range of 90-300 K. Ba{sub 2}HoTaO{sub 6} has a cubic structure in space group Fm3-barm at room temperature. A proper ferroelastic phase transition to I4/m tetragonal symmetry occurs near approximately 260 K. Analysis of the spontaneous tetragonal strain versus temperature indicated that the phase transition is second order in nature.

  4. Survey of Technologies to Support Reuse of Gloveboxes at LANL TA-55

    SciTech Connect (OSTI)

    L. C. Cadwallader; P. A. Pinson.

    1998-11-01

    This report is a summary of ideas and technologies available to support reuse of plutonium gloveboxes at the Los Alamos National Laboratory (LANL) Technical Area 55 (TA-55). This work is the second of two deliverables in the task to enhance glovebox design for longevity and reusability at TA-55. The report presents several design change suggestions to be evaulated for their feasibility by LANL glovebox designers. The report also describes some techniques to be evaluated by LANL for their usefulness in reducing glovebox waste.

  5. DOE - Office of Legacy Management -- TA-1 Manhattan Laboratory - NM 11

    Office of Legacy Management (LM)

    TA-1 Manhattan Laboratory - NM 11 FUSRAP Considered Sites Site: TA-1 MANHATTAN LABORATORY (NM.11 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: Main Technical Area LASL LANL NM.11-1 NM.11-2 NM.11-3 Location: Los Alamos , New Mexico NM.11-3 Evaluation Year: 1985 NM.11-1 Site Operations: Nuclear weapons research and development. NM.11-1 NM.11-3 Site Disposition: Site Disposition NM.11-1 Radioactive Materials Handled: Yes Primary Radioactive Materials

  6. Preparation, characterization and photocatalytic property of nanosized K-Ta mixed oxides via a sol-gel method

    SciTech Connect (OSTI)

    Zhang, Gaoke; Jiang, Wei; Yu, Shujie

    2010-11-15

    Pyrochlore-type K{sub 2}Ta{sub 2}O{sub 6} compound cannot be obtained by a conventional solid-state reaction. Here, we report the synthesis of K{sub 2}Ta{sub 2}O{sub 6} and tetragonal tungsten bronze (TTB)-type K{sub 6}Ta{sub 10.8}O{sub 30} nanopowders using a facile and low-cost sol-gel method at low temperature. The as-prepared samples were characterized by XRD, TG-DSC, FESEM, UV-vis diffuse reflectance spectrum and XPS. The compound K{sub 2}Ta{sub 2}O{sub 6} was formed at 700 {sup o}C and reached complete crystallization at 750 {sup o}C, and decomposed into pure K{sub 6}Ta{sub 10.8}O{sub 30} with the volatilization of K{sub 2}O at 900 {sup o}C. The transformation of K{sub 2}Ta{sub 2}O{sub 6} to K{sub 6}Ta{sub 10.8}O{sub 30} is reported for the first time. The band gap of the pure K{sub 2}Ta{sub 2}O{sub 6} and K{sub 6}Ta{sub 10.8}O{sub 30} samples was found to be about 4.16 and 3.63 eV, respectively. The as-prepared K{sub 2}Ta{sub 2}O{sub 6} sample exhibited an efficient photocatalytic activity for the decomposition of azo dye acid red G (ARG) and 4-nitrophenol (4-NP, a typical persistent organic pollutant) solution under UV irradiation. According to the experimental results, the mechanism of the photocatalytic reaction over K{sub 2}Ta{sub 2}O{sub 6} was discussed.

  7. BPAT webTrans Update to CDE Shared Path Summary - October 9,...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Notices Rates Standards of Conduct Tariff TF Web Based Training Notice: BPAT webTrans Update to CDE Shared Path Summary Posted Date: 1092015 BPAT is deploying a change to...

  8. BPAT webTrans Update to CDE Shared Path Summary - November 5...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Notices Rates Standards of Conduct Tariff TF Web Based Training Notice: BPAT webTrans Update to CDE Shared Path Summary Posted Date: 1152015 BPAT is deploying a change to...

  9. TransCanada Power Mktg Ltd (New Hampshire) | Open Energy Information

    Open Energy Info (EERE)

    Place: New Hampshire Phone Number: 1.800.661.3805 Website: www.transcanada.comindex.html Twitter: @TransCanada Outage Hotline: 1-800-447-8066 References: EIA Form EIA-861 Final...

  10. Regulatory Interactions in ProKaryotes from RegTransBase

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Dubchak, Inna; Gelfand, Mikhail

    RegTransBase, a manually curated database of regulatory interactions in prokaryotes, captures the knowledge in published scientific literature using a controlled vocabulary. RegTransBase describes a large number of regulatory interactions reported in many organisms and contains various types of experimental data, in particular: the activation or repression of transcription by an identified direct regulator determining the transcriptional regulatory function of a protein (or RNA) directly binding to DNA or RNA mapping or prediction of binding sites for a regulatory protein characterization of regulatory mutations Currently, the RegTransBase content is derived from about 3000 relevant articles describing over 7000 experiments in relation to 128 microbes. It contains data on the regulation of about 7500 genes and evidence for 6500 interactions with 650 regulators. RegTransBase also contains manually created position weight matrices (PWM) that can be used to identify candidate regulatory sites in over 60 species. (Specialized Interface)

  11. Integrated Market Modeling of Hydrogen Transition Scenarios with HyTrans |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy Integrated Market Modeling of Hydrogen Transition Scenarios with HyTrans Integrated Market Modeling of Hydrogen Transition Scenarios with HyTrans Presentation by Paul Leiby of Oak Ridge National Laboratory at the Joint Meeting on Hydrogen Delivery Modeling and Analysis, May 8-9, 2007 deliv_analysis_leiby.pdf (740.06 KB) More Documents & Publications DOE Hydrogen Transition Analysis Workshop Hydrogen Policy and Analyzing the Transition Hydrogen Transition Study

  12. Analyzing the Impacts of Policies and Technological Change Using HyTrans

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Scenarios for 2010 Scenarios for 2010 - - 2025 & Beyond: 2025 & Beyond: Analyzing the Impacts of Policies and Analyzing the Impacts of Policies and Technological Change Using Technological Change Using HyTrans HyTrans David L. Greene, ORNL David L. Greene, ORNL Paul N. Leiby, ORNL Paul N. Leiby, ORNL David Bowman, David Bowman, Econotech Econotech Elzbieta Tworek, Strata Elzbieta Tworek, Strata - - G G 2010 2010 - - 2025 Scenario Analysis Workshop 2025 Scenario Analysis Workshop August 9

  13. Application to Export Electric Energy OE Docket No. EA-216-C TransAlta

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Energy Marketing (U.S) Inc . Canadian Electrical Association Comments | Department of Energy Export Electric Energy OE Docket No. EA-216-C TransAlta Energy Marketing (U.S) Inc . Canadian Electrical Association Comments Application to Export Electric Energy OE Docket No. EA-216-C TransAlta Energy Marketing (U.S) Inc . Canadian Electrical Association Comments Protest of the Canadian Electricity Association and the Electric Power Supply Association to Sierra Club's Notice of Intervention and

  14. TA-55 Final Safety Analysis Report Comparison Document and DOE Safety Evaluation Report Requirements

    SciTech Connect (OSTI)

    Alan Bond

    2001-04-01

    This document provides an overview of changes to the currently approved TA-55 Final Safety Analysis Report (FSAR) that are included in the upgraded FSAR. The DOE Safety Evaluation Report (SER) requirements that are incorporated into the upgraded FSAR are briefly discussed to provide the starting point in the FSAR with respect to the SER requirements.

  15. CRAD, Radiological Controls- Los Alamos National Laboratory TA 55 SST Facility

    Broader source: Energy.gov [DOE]

    A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for an assessment of the Radiation Protection Program at the Los Alamos National Laboratory TA 55 SST Facility.

  16. High-pressure shock behavior of WC and Ta2O5 powders.

    SciTech Connect (OSTI)

    Knudson, Marcus D.; Reinhart, William Dodd; Vogler, Tracy John; Root, Seth

    2011-10-01

    Planar shock experiments were conducted on granular tungsten carbide (WC) and tantalum oxide (Ta{sub 2}O{sub 5}) using the Z machine and a 2-stage gas gun. Additional shock experiments were also conducted on a nearly fully dense form of Ta{sub 2}O{sub 5}. The experiments on WC yield some of the highest pressure results for granular materials obtained to date. Because of the high distention of Ta{sub 2}O{sub 5}, the pressures obtained were significantly lower, but the very high temperatures generated led to large contributions of thermal energy to the material response. These experiments demonstrate that the Z machine can be used to obtain accurate shock data on granular materials. The data on Ta{sub 2}O{sub 5} were utilized in making improvements to the P-{lambda} model for high pressures; the model is found to capture the results not only of the Z and gas gun experiments but also those from laser experiments on low density aerogels. The results are also used to illustrate an approach for generating an equation of state using only the limited data coming from nanoindentation. Although the EOS generated in this manner is rather simplistic, for this material it gives reasonably good results.

  17. CRAD, Criticality Safety- Los Alamos National Laboratory TA 55 SST Facility

    Broader source: Energy.gov [DOE]

    A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for an assessment of the Criticality Safety program at the Los Alamos National Laboratory, TA 55 SST Facility.

  18. CRAD, Conduct of Operations- Los Alamos National Laboratory TA 55 SST Facility

    Broader source: Energy.gov [DOE]

    A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for an assessment of the Conduct of Operations program at the Los Alamos National Laboratory, TA 55 SST Facility.

  19. CRAD, Quality Assurance- Los Alamos National Laboratory TA 55 SST Facility

    Broader source: Energy.gov [DOE]

    A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for an assessment of the Quality Assurance Program at the Los Alamos National Laboratory TA 55 SST Facility.

  20. CRAD, Safety Basis- Los Alamos National Laboratory TA 55 SST Facility

    Broader source: Energy.gov [DOE]

    A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for an assessment of the Safety Basis at the Los Alamos National Laboratory TA 55 SST Facility.

  1. Landslides and other mass movements near TA-33, northern White Rock Canyon, New Mexico. Final report

    SciTech Connect (OSTI)

    Dethier, D.P.

    1993-09-01

    Massive slump complexes and at least two rock avalanches flank the eastern rim of the Pajarito Plateau along northern White Rock Canyon, north of TA-33. Landslides failed along mechanically weak rocks in the Santa Fe Group, within the Puye Formation, or in Pliocene alluvial and lacustrine units. The landslides are mainly of early or middle Pleistocene age. The toe area of at least,one slump complex has been active in the late Pleistocene, damming White Rock Canyon near the mouth of Water Canyon. Lacustrine sediment that filled this lake, or series of lakes, to an elevation of at least 1710 m is preserved at a number of upstream sites, including a deposit near the Buckman townsite that exposes 30 m of lacustrine sediment. Charcoal collected at several sites has been submitted for {sup 14}C dating. Landslides, however, probably do not represent a significant short-term threat to the material disposal areas at TA-33. Bedrock that lies beneath the TA-33 mesa is relatively stable, the mesa shows no signs of incipient failure, and past periods of slide activity were responses to rapid downcutting of the Rio Grande and climate change, probably over periods of several decades, at least. Rockfall and headward erosion of gullies do not represent significant decadal hazards on canyon rims near TA-33. Gully migration near MDA-K is a potential threat, but the gullies were not examined in detail. A system of north-trending faults, at least one of which displays Pleistocene activity, bisects the TA-33 mesa. If these faults are capable of producing significant seismic shaking, generalizations about landslide and rockfall hazards must be reevaluated.

  2. The Use of TaBoRR as a Heavy Oil Upgrader

    SciTech Connect (OSTI)

    Lee Brecher; Charles Mones

    2009-02-05

    Preliminary testing has shown that Western Research Institute's (WRI) Tank Bottom Recovery and Remediation (TaBoRR{reg_sign}) technology shows promise for heavy oil upgrading. Approximately 70 to 75 wt% of a Canadian Cold Lake bitumen feed was converted to a partially upgraded overhead product that could be transported directly by pipeline or blended with the parent bitumen to produce transportable crude. TaBoRR{reg_sign} was originally developed to remediate tank bottom wastes by producing a distillate product and solid waste. TaBoRR{reg_sign}'s processing steps include breaking a water-oil emulsion, recovering a light hydrocarbon fraction by distillation in a stripper unit, and pyrolyzing the residua reducing it to additional overhead and a benign coke for disposal. Cold Lake bitumen was tested in WRI's bench-scale equipment to evaluate the potential use of TaBoRR{reg_sign} technology for heavy oil upgrading to produce a stable, partially (or fully) upgraded product that will allow diluent-reduced or diluent-free transportation of bitumen or ultra-heavy crudes to market. Runs were conducted at temperatures of low, intermediate and high severity in the stripper to produce stripper overhead and bottoms. The bottoms from each of these runs were processed further in a 6-inch screw pyrolyzer to produce pyrolyzer overhead for blending with the corresponding stripper overheads. Proceeding in this fashion yielded three partially upgraded crudes. The products from TaBoRR{reg_sign} processing, the parent bitumen, and bitumen blends were subjected to stability and compatibility testing at the National Centre for Upgrading Technology (NCUT). Chemical analyses of the overhead product blends have met pipeline specifications for viscosity and density; however the bromine number does not, which might indicate the need for mild hydrotreating. Storage stability tests showed the blends to be stable. The blends were also soluble and compatible with most other Alberta crudes.

  3. Infrared absorption of trans-1-chloromethylallyl and trans-1-methylallyl radicals produced in photochemical reactions of trans-1,3-butadiene and C Script-Small-L {sub 2} in solid para-hydrogen

    SciTech Connect (OSTI)

    Bahou, Mohammed; Wu, Jen-Yu; Tanaka, Keiichi; Lee, Yuan-Pern

    2012-08-28

    The reactions of chlorine and hydrogen atoms with trans-1,3-butadiene in solid para-hydrogen (p-H{sub 2}) were investigated with infrared (IR) absorption spectra. When a p-H{sub 2} matrix containing C Script-Small-L {sub 2} and trans-1,3-butadiene was irradiated with ultraviolet light at 365 nm, intense lines at 650.3, 809.0, 962.2, 1240.6 cm{sup -1}, and several weaker ones due to the trans-1-chloromethylallyl radical, Bullet (CH{sub 2}CHCH)CH{sub 2}C Script-Small-L , appeared. Observed wavenumbers and relative intensities agree with the anharmonic vibrational wavenumbers and IR intensities predicted with the B3PW91/6-311++g(2d, 2p) method. That the C Script-Small-L atom adds primarily to the terminal carbon atom of trans-1,3-butadiene is in agreement with the path of minimum energy predicted theoretically, but in contrast to the reaction of C Script-Small-L + propene in solid p-H{sub 2}[J. Amicangelo and Y.-P. Lee, J. Phys. Chem. Lett. 1, 2956 (2010)] in which the addition of C Script-Small-L to the central C atom is favored, likely through steric effects in a p-H{sub 2} matrix. A second set of lines, intense at 781.6, 957.9, 1433.6, 2968.8, 3023.5, 3107.3 cm{sup -1}, were observed when the UV-irradiated C Script-Small-L {sub 2}/trans-1,3-butadiene/p-H{sub 2} matrix was further irradiated with IR light from a SiC source. These lines are assigned to the trans-1-methylallyl radical, Bullet (CH{sub 2}CHCH)CH{sub 3}, produced from reaction of 1,3-butadiene with a H atom resulted from the reaction of C Script-Small-L atoms with solid p-H{sub 2} exposed to IR radiation.

  4. Electronic and optical properties of TaO{sub 1-x}N{sub 1+x}-based alloys

    SciTech Connect (OSTI)

    Al-Aqtash, Nabil; Apostol, Florin; Mei, Wai-Ning; Sabirianov, Renat F.; Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE 68588

    2013-02-15

    TaON is considered as a potential candidate as a visible-light responsive photocatalyst. We report the results of ab initio studies of electronic structure of TaON-based alloys. Specifically, we show that the position of conduction and valence band can be modified by varying the oxygen and nitrogen concentrations in TaO{sub 1-x}N{sub 1+x}. We find that the band gap decreases monotonically with the increase of N/O ratio. The band gap energy is decreased in monoclinic TaON from near 2.3 eV to just over 1.7 eV (i.e., by 35%) when N/O ratio is increased from 3/5 to 5/3. Our calculations show that the band gap reduces in a series of experimentally fabricated alloys ZrTa{sub 3}O{sub 5}N{sub 3}{yields}TaON{yields}YTa{sub 7}O{sub 7}N{sub 8}. The band gap reduction is mostly associated with the change in the position of the valence band due to the hybridization of N 2p states, while the conduction band consisting mostly of Ta 5d-states is not sensitive to N content. The calculated optical absorption spectra show reduction in the optical band gap with increasing N/O ratio. - Graphical abstract: Band gap energy of TaO{sub 1-x}N{sub 1+x} as a function of N/O ratio. Highlights: Black-Right-Pointing-Pointer The electronic and optical properties of TaON-based alloys are studied using DFT. Black-Right-Pointing-Pointer The position of conduction and valence bands can be modified by varying N/O ratio. Black-Right-Pointing-Pointer The band gap decreases monotonically with the increase of N/O ratio in TaO{sub 1-x}N{sub 1+x}. Black-Right-Pointing-Pointer The band gap reduces in a series of fabricated alloys ZrTa{sub 3}O{sub 5}N{sub 3}{yields}TaON{yields}YTa{sub 7}O{sub 7}N{sub 8}. Black-Right-Pointing-Pointer The optical band gap decreases with the increase of N/O ratio.

  5. Competing decay modes of a high-spin isomer in the proton-unbound nucleus ??Ta*

    SciTech Connect (OSTI)

    Carroll, R. J.; Page, R. D.; Joss, D. T.; Uusitalo, J.; Darby, I. G.; Andgren, K.; Cederwall, B.; Eeckhaudt, S.; Grahn, T.; Gray-Jones, C.; Greenlees, P. T.; Hadinia, B.; Jones, P. M.; Julin, R.; Juutinen, S.; Leino, M.; Leppnen, A. -P.; Nyman, M.; O'Donnell, D.; Pakarinen, J.; Rahkila, P.; Sandzelius, M.; Sarn, J.; Scholey, C.; Seweryniak, D.; Simpson, J.

    2015-01-01

    An isomeric state at high spin and excitation energy was recently observed in the proton-unbound nucleus 158Ta. This state was observed to decay by both ? and ? decay modes. The large spin change required to decay via ?-ray emission incurs a lifetime long enough for ? decay to compete. The ? decay has an energy of 8644(11) keV, which is among the highest observed in the region, a partial half-life of 440(70) ?s and changes the spin by 11?. In this study, additional evidence supporting the assignment of this ? decay to the high-spin isomer in 158Ta will be presented.

  6. Reliability analysis for the facility data acquisition interface system upgrade at TA-55

    SciTech Connect (OSTI)

    Turner, W.J.; Pope, N.G.; Brown, R.E.

    1995-05-01

    Because replacement parts for the existing facility data acquisition interface system at TA-55 have become scarce and are no longer being manufactured, reliability studies were conducted to assess various possible replacement systems. A new control system, based on Allen-Bradley Programmable Logic Controllers (PLCs), was found to have a likely reliability 10 times that of the present system, if the existing Continuous Air Monitors (CAMS) were used. Replacement of the old CAMs with new CAMs will result in even greater reliability as these are gradually phased in. The new PLC-based system would provide for hot standby processors, redundant communications paths, and redundant power supplies, and would be expandable and easily maintained, as well as much more reliable. TA-55 is the Plutonium Processing Facility which processes and recovers Pu-239 from scrap materials.

  7. Multiband Te p Based Superconductivity of Ta4Pd3Te16

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Singh, David J.

    2014-10-06

    We recently discovered that Ta4Pd3Te16 is a superconductor that has been suggested to be an unconventional superconductor near magnetism. Here, we report electronic structure calculations showing that despite the layered crystal structure the material is an anisotropic three-dimensional (3D) metal. The Fermi surface contains prominent one-dimensional (1D) and two-dimensional (2D) features, including nested 1D sheets, a 2D cylindrical section, and a 3D sheet. Moreover, the electronic states that make up the Fermi surface are mostly derived from Te p states with small Ta d and Pd d contributions. This places the compound far from magnetic instabilities. The results are discussedmore » in terms of multiband superconductivity.« less

  8. Preliminary results for HIP bonding Ta to W targets for the materials test station

    SciTech Connect (OSTI)

    Dombrowski, David E; Maloy, Stuart A

    2009-01-01

    Tungsten targets for the Materials Test Station (MTS) were clad with thin tantalum cover plates and a tantalum frame using hot isostatic pressing (HIP). A preliminary HIP parameter study showed good bonding and intimate mechanical contact for Ta cover plate thicknesses of 0.25 mm (0.010 inch) and 0.38 mm (0.015 inch). HIP temperatures of full HIP runs were 1500 C (2732 F). HIP pressure was 203 MPa (30 ksi).

  9. Regulatory Interactions in ProKaryotes from RegTransBase

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Dubchak, Inna; Gelfand, Mikhail

    RegTransBase, a manually curated database of regulatory interactions in prokaryotes, captures the knowledge in published scientific literature using a controlled vocabulary. RegTransBase describes a large number of regulatory interactions reported in many organisms and contains various types of experimental data, in particular: the activation or repression of transcription by an identified direct regulator determining the transcriptional regulatory function of a protein (or RNA) directly binding to DNA or RNA mapping or prediction of binding sites for a regulatory protein characterization of regulatory mutations. RegTransBase also contains manually created position weight matrices (PWM) that can be used to identify candidate regulatory sites in over 60 species. (Specialized Interface)

  10. Regulation study for the facility control system design at the Facility Operations Center at TA55

    SciTech Connect (OSTI)

    1994-03-16

    NMT-8 is proposing to upgrade the existing Facility Control System (FCS) located within the Facility Operations Center (FOC) at the TA-55 Plutonium Processing and Handling Facility (PPHF). The FCS modifications will upgrade the existing electronics to provide better reliability of system functions. Changes include replacement of the FCS computers and field multiplex units which are used for transmitting systems data. Data collected at the FCS include temperature, pressure, contact closures, etc., and are used for monitoring and/or control of key systems at TA-55. Monitoring is provided for the electrical power system status, PF-4 HVAC air balance status (Static Differential pressure), HVAC fan system status, site chill water return temperature, fire system information, and radioactive constant air monitors alarm information, site compressed air pressure and other key systems used at TA-55. Control output signals are provided for PF-4 HVAC systems, and selected alarms for criticality, fire, loss of pressure in confinement systems. A detailed description of the FCS modifications is provided in Section 2.

  11. Pressure-induced amorphization of La{sub 1/3}TaO{sub 3}

    SciTech Connect (OSTI)

    Noked, O.; Melchior, A.; Shuker, R.; Livneh, T.; Steininger, R.; Kennedy, B.J.; Sterer, E.

    2013-06-15

    La{sub 1/3}TaO{sub 3}, an A-site cation deficient perovskite, has been studied under pressure by synchrotron X-ray powder diffraction and Raman spectroscopy. It undergoes irreversible pressure induced amorphization at P=18.5 GPa. An almost linear unit cell volume decrease vs. pressure is observed from ambient pressure up to the phase transition. The Raman spectroscopy also shows amorphization at the same pressure, with positive shifts of all modes as a function of pressure. The pressure dependence of the E{sub g} and A{sub 1g} Raman modes arising from the octahedral oxygen network is discussed. - Graphical abstract: La{sub 1/3}Tao{sub 3} exhibits linear pressure–volume relation until irreversible pressure induced amorphization at 18.5 Gpa. - Highlights: • La{sub 1/3}TaO{sub 3} has been studied under pressure by synchrotron XRD and Raman spectroscopy. • La{sub 1/3}TaO{sub 3} undergoes irreversible pressure induced amorphization around 18.5 GPa. • The transition is manifested in both XRD and Raman measurements. • A linear P–V relation is observed from ambient pressure up to the phase transition.

  12. Isothermal oxidation behavior and microstructure of plasma surface Ta coating on ?-TiAl

    SciTech Connect (OSTI)

    Song, Jian; Zhang, Ping-Ze Wei, Dong-Bo; Wei, Xiang-Fei; Wang, Ya

    2014-12-15

    The oxidation behavior of ?-TiAl with Ta surface coating fabricated by double glow plasma surface alloying technology was investigated by thermogravimetric method. Oxidation experiments were carried out at 750 C and 850 C in air for 100 h. The modification layer was comprised of deposition layer and diffusion layer, which metallurgically adhered to the substrate. Tantalum element decreased with the case depth. The oxidation morphology was studied by a scanning electron microscope and X-ray diffraction. The results highlighted that in the oxidizing process of the oxidation, the phase containing Ta-richer may restrain diffusing outward of the element Al in the matrix. Ti diffused outward, and formed the TiO{sub 2} scales, while the middle layer was rich in Al, and formed the continuous Al{sub 2}O{sub 3} scales after oxidation, which was effective to prevent further infiltration of oxygen atoms, and as a result the oxidation resistance increased immensely. - Highlights: A Ta modified coating was prepared on ?-TiAl using DGP surface alloying technology. The modification layer metallurgically adhered to the substrate. The bonding force is about 60 N, satisfying the demands of practical use. The oxidation resistance increased immensely at 750 C and 850 C.

  13. Application to Export Electric Energy OE Docket No. EA-216-D TransAlta

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Energy Marketing (U.S.) Inc.: Federal Register Notice, Volume 81, No. 46 - March 9, 2016 | Department of Energy Export Electric Energy OE Docket No. EA-216-D TransAlta Energy Marketing (U.S.) Inc.: Federal Register Notice, Volume 81, No. 46 - March 9, 2016 Application to Export Electric Energy OE Docket No. EA-216-D TransAlta Energy Marketing (U.S.) Inc.: Federal Register Notice, Volume 81, No. 46 - March 9, 2016 Application from TEMUS to export electric energy to Canada. Federal Register

  14. Integrated Market Modeling of Hydrogen Transition Scenarios with HyTrans

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Integrated Market Modeling of Hydrogen Transition Scenarios with HyTrans Paul N. Leiby, David L. Greene and David Bowman Oak Ridge National Laboratory A presentation to the Hydrogen Delivery Analysis Meeting FreedomCAR and Fuels Partnership Delivery, Storage and Hydrogen Pathways Tech Teams May 8-9, 2007 Columbia, MD 2 OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY Drawing from several other DOE models, HyTrans integrates supply and demand in a dynamic non-linear market model to 2050.

  15. Structure, magnetism, specific heat, and dielectric properties of Eu{sub 2}Ta{sub 2}O{sub 7}

    SciTech Connect (OSTI)

    Kolodiazhnyi, T. Sakurai, H.; Matsushita, Y.

    2014-11-17

    Polycrystalline Eu{sub 2}Ta{sub 2}O{sub 7} containing layered perovskite slabs was prepared and analyzed. Eu{sub 2}Ta{sub 2}O{sub 7} crystallizes in the orthorhombic centrosymmetric Cmcm space group (with unit cell: a?=?3.95156(9), b?=?27.0775(6), and c?=?5.68279(13) ) isomorphous with high-temperature Sr{sub 2}Ta{sub 2}O{sub 7}. Dielectric measurements reveal that, in contrast to Sr{sub 2}Ta{sub 2}O{sub 7} which is ferroelectric below 166?K, Eu{sub 2}Ta{sub 2}O{sub 7} remains paraelectric down to at least 0.45?K and shows no magneto-dielectric coupling. Magnetic data in the 2400?K range indicate an antiferromagnetic phase transition with a sharp susceptibility peak at 2.71(5) K. Further analysis using specific heat measurements reveals that the second magnetic phase transition occurs at 1.10(5) K and dominates the spin entropy of the Eu{sup 2+} 4f{sup 7} ions. The possible origin of the two successive magnetic phase transitions in Eu{sub 2}Ta{sub 2}O{sub 7} requires further studies.

  16. Observation of surface to bulk interatomic Auger decay from Ta(100)

    SciTech Connect (OSTI)

    Jensen, E. ); Bartynski, R.A. ); Weinert, M. ); Hulbert, S.L.; Johnson, E.D.; Garrett, R.F. )

    1990-06-15

    Core-valence-valence ({ital CVV}) Auger spectra from Ta(100) taken in coincidence with bulk and surface-shifted 4{ital f}{sub 7/2} core-level emission are presented. These data are compared with self-convolutions of calculations of the {ital d}-band densities of states for the surface and subsurface layers of a nine-layer slab. Agreement of the bulk spectrum with the calculation is good; agreement for the surface spectrum is very poor. These data are explained by proposing an interatomic surface to bulk Auger decay mode for the surface core hole that is competitive with the conventional {ital CVV} decay process.

  17. Seismic Vulnerability Assessment Waste Characterization Reduction and Repackaging Building, TA-50-69

    SciTech Connect (OSTI)

    M.W.Sullivan; J.Ruminer; I.Cuesta

    2003-02-02

    This report presents the results of the seismic structural analyses completed on the Waste Characterization Reduction and Repackaging (WCRR) Building in support of ongoing safety analyses. WCRR is designated as TA-50-69 at Los Alamos National Laboratory, Los Alamos, New Mexico. The facility has been evaluated against Department of Energy (DOE) seismic criteria for Natural Phenomena Hazards (NPH) Performance Category II (PC 2). The seismic capacities of two subsystems within the WCRR building, the material handling glove box and the lift rack immediately adjacent to the Glove Box are also documented, and the results are presented.

  18. Multiband semimetallic electronic structure of superconducting Ta2PdSe5

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Singh, David Joseph

    2015-04-24

    We report the electronic structure and related properties of the superconductor Ta2PdSe5 as determined from density functional calculations. The Fermi surface has two disconnected sheets, both derived from bands of primarily chalcogenide p states. These are a corrugated hole cylinder and a heavier complex shaped electron sheet. The sheets contain 0.048 holes and a compensating number of electrons per formula unit, making the material a semimetallic superconductor. The results support the presence of two band superconductivity, although a discrepancy in the specific heat is noted. This discrepancy is discussed as a possible consequence of Pd deficiency in samples.

  19. Water Resistant Container Technical Basis Document for the TA-55 Criticality Safety Program

    SciTech Connect (OSTI)

    Smith, Paul Herrick; Teague, Jonathan Gayle

    2015-04-30

    Criticality safety at TA-55 relies on nuclear material containers that are water resistant to prevent significant amounts of water from coming into contact with fissile material in the event of a fire that causes a breach of glovevbox confinement and subsequent fire water ingress. A “water tight container” is a container that will not allow more than 50ml of water ingress when fully submerged, except when under sufficient pressure to produce structural discontinuity. There are many types of containers, welded containers, hermetically sealed containers, filtered containers, etc.

  20. Magnetization reversal induced by in-plane current in Ta/CoFeB/MgO structures with perpendicular magnetic easy axis

    SciTech Connect (OSTI)

    Zhang, C.; Yamanouchi, M. Ikeda, S.; Sato, H.; Fukami, S.; Matsukura, F.; Ohno, H.

    2014-05-07

    We investigate in-plane current-induced magnetization reversal under an in-plane magnetic field in Hall bar shaped devices composed of Ta/CoFeB/MgO structures with perpendicular magnetic easy axis. The observed relationship between the directions of current and magnetization switching and Ta thickness dependence of magnetization switching current are accordance with those for magnetization reversal by spin transfer torque originated from the spin Hall effect in the Ta layer.

  1. Preparation, characterization of the Ta-doped ZnO nanoparticles and their photocatalytic activity under visible-light illumination

    SciTech Connect (OSTI)

    Kong Jizhou; Li Aidong; Zhai Haifa; Gong Youpin; Li Hui; Wu Di

    2009-08-15

    This paper describes a novel catalyst of the Ta-doped ZnO nanocrystals prepared by a modified polymerizable complex method using the water-soluble tantalum precursor as the sources of Ta. The catalysts were characterized by means of various analytical techniques as a function of Ta content (x=0-4 mol%) systematically. A remarkable advantage of the results was confirmed that dopant Ta enhanced the visible-light absorption of ZnO and the low-solubility tantalum doping could restrain the growth of crystal and minish the particle size. The relationship between the physicochemical property and the photocatalytic performance was discussed, and it was found that the photocatalytic activity in the photochemical degradation of methylene blue under visible-light irradiation (lambda>=420 nm) was dependent on the contents of the dopant, which could affect the particle size, concentration of surface hydroxyl groups and active hydrogen-related defect sites, and the visible-light absorption. The highest photocatalytic activity was obtained for the 1.0 mol% Ta-doped ZnO sample. - Graphical abstract: The addition of the tantalum into ZnO prepared by a modified polymerizable complex method not only restrains the growth of crystal, minish the particle size, but also changes the nanocrystal morphology.

  2. Dependence of inverse-spin Hall effect and spin-rectified voltage on tantalum thickness in Ta/CoFeB bilayer structure

    SciTech Connect (OSTI)

    Kim, Sang-Il; Seo, Min-Su; Park, Seung-Young; Kim, Dong-Jun; Park, Byong-Guk

    2015-01-19

    Ta-layer thickness (t{sub Ta}) dependence of the measured DC voltage V from the inverse-spin Hall effect (ISHE) in Ta/CoFeB bilayer structure is experimentally investigated using the ferromagnetic resonance in the TE{sub 011} resonant cavity. The ISHE signals excluding the spin-rectified effect (SRE) were separated from the fitted curve of V against t{sub Ta}. For t{sub Ta} ≈ λ{sub Ta} (Ta-spin diffusion length = 2.7 nm), the deviation in ISHE voltage V{sub ISH} between the experimental and theoretical values is significantly increased because of the large SRE contribution, which also results in a large deviation in the spin Hall angle θ{sub SH} (from 10% to 40%). However, when t{sub Ta} ≫ λ{sub Ta}, the V{sub ISH} values are consistent with theoretical values because the SRE terms become negligible, which subsequently improves the accuracy of the obtained θ{sub SH} within 4% deviation. The results will provide an outline for an accurate estimation of the θ{sub SH} for materials with small λ value, which would be useful for utilizing the spin Hall effect in a 3-terminal spintronic devices in which magnetization can be controlled by in-plane current.

  3. High Nb, Ta, and Al creep- and oxidation-resistant austenitic stainless steel

    DOE Patents [OSTI]

    Brady, Michael P [Oak Ridge, TN; Santella, Michael L [Knoxville, TN; Yamamoto, Yukinori [Oak Ridge, TN; Liu, Chain-tsuan [Oak Ridge, TN

    2010-07-13

    An austenitic stainless steel HTUPS alloy includes, in weight percent: 15 to 30 Ni; 10 to 15 Cr; 2 to 5 Al; 0.6 to 5 total of at least one of Nb and Ta; no more than 0.3 of combined Ti+V; up to 3 Mo; up to 3 Co; up to 1 W; up to 0.5 Cu; up to 4 Mn; up to 1 Si; 0.05 to 0.15 C; up to 0.15 B; up to 0.05 P; up to 1 total of at least one of Y, La, Ce, Hf, and Zr; less than 0.05 N; and base Fe, wherein the weight percent Fe is greater than the weight percent Ni wherein said alloy forms an external continuous scale comprising alumina, nanometer scale sized particles distributed throughout the microstructure, said particles comprising at least one composition selected from the group consisting of NbC and TaC, and a stable essentially single phase fcc austenitic matrix microstructure, said austenitic matrix being essentially delta-ferrite-free and essentially BCC-phase-free.

  4. A new anatase-type phase in the system Mg-Ta-O-N

    SciTech Connect (OSTI)

    Schilling, H.; Lerch, M. . E-mail: lerch@chem.tu-berlin.de; Boerger, A.; Becker, K.-D.; Wolff, H.; Dronskowski, R.; Bredow, T.; Tovar, M.; Baehtz, C.

    2006-08-15

    Magnesium doped tantalum oxynitrides were prepared by ammonolysis of amorphous mixed oxides. An orange colored anatase-type phase with the composition Mg{sub 0.05}Ta{sub 0.95}O{sub 1.15}N{sub 0.85} was found. It is metastable and undergoes a phase transformation to a baddeleyite-type phase between 900 and 1000deg. C. X-ray diffraction measurements indicate spacegroup I4{sub 1}/amd with lattice parameters a=391.986(6)pm and c=1011.19(3)pm. A possible anion ordering was examined by theoretical methods and neutron diffraction experiments. In addition, anosovite-type (Ti{sub 3}O{sub 5}) phases Mg{sub x}Ta{sub 3-x}O{sub 3x}N{sub 5-3x}; 0=

  5. Microstructure and mechanical properties of Ti-35Nb-6Ta alloy after thermomechanical treatment

    SciTech Connect (OSTI)

    Malek, J.; Hnilica, F.; Vesely, J.; Smola, B.; Bartakova, S.; Vanek, J.

    2012-04-15

    The influence of thermo-mechanical treatment on microstructure and mechanical properties of T-35Nb-6Ta has been studied. The thermo-mechanical treatment was chosen to correspond to the production of wire with suitable mechanical properties for dental implants. After casting the alloy was hot forged (700-900 Degree-Sign C), solution treated (850 Degree-Sign C/30 min, water quenched) and cold swaged (reductions up to 91%). The annealing (700 Degree-Sign C/3 h/furnace) or aging (450 Degree-Sign C/8 h/furnace) was used as final heat treatment. The microstructure was studied by using light microscopy, scanning electron microscopy, transmission electron microscopy and XRD analysis. Cold swaging introduces microstructure consisting of highly deformed {beta}-phase grains with dislocation tangles and twins, which ensures high tensile strength about 820 MPa, low Young's modulus ({approx} 50 GPa) and good ductility {approx} 10%. Subsequent aging increases tensile strength (1000 MPa) as well as Young's modulus (75 GPa) without diminishing ductility. Annealing at 700 Degree-Sign C slightly decreases tensile strength (730 MPa) and increases the ductility and Young's modulus (17% and 62 GPa respectively). The mechanical properties attained recommend the thermo-mechanical treatment for production of wires for dental implants. - Highlights: Black-Right-Pointing-Pointer Ti35Nb6Ta alloy prepared via arc melting. Black-Right-Pointing-Pointer Thermo mechanical treatment. Black-Right-Pointing-Pointer Microstructural changes. Black-Right-Pointing-Pointer Mechanical properties.

  6. Charge trapping of Ge-nanocrystals embedded in TaZrO{sub x} dielectric films

    SciTech Connect (OSTI)

    Lehninger, D. Seidel, P.; Geyer, M.; Schneider, F.; Heitmann, J.; Klemm, V.; Rafaja, D.; Borany, J. von

    2015-01-12

    Ge-nanocrystals (NCs) were synthesized in amorphous TaZrO{sub x} by thermal annealing of co-sputtered Ge-TaZrO{sub x} layers. Formation of spherical shaped Ge-NCs with small variation of size, areal density, and depth distribution was confirmed by high-resolution transmission electron microscopy. The charge storage characteristics of the Ge-NCs were investigated by capacitance-voltage and constant-capacity measurements using metal-insulator-semiconductor structures. Samples with Ge-NCs exhibit a maximum memory window of 5 V by sweeping the bias voltage from −7 V to 7 V and back. Below this maximum, the width of the memory window can be controlled by the bias voltage. The fitted slope of the memory window versus bias voltage characteristics is very close to 1 for samples with one layer Ge-NCs. A second layer Ge-NCs does not result in a second flat stair in the memory window characteristics. Constant-capacity measurements indicate charge storage in trapping centers at the interfaces between the Ge-NCs and the surrounding materials (amorphous matrix/tunneling oxide). Charge loss occurs by thermal detrapping and subsequent band-to-band tunneling. Reference samples without Ge-NCs do not show any memory window.

  7. Development of Ta-based Superconducting Tunnel Junction X-ray Detectors for Fluorescence XAS

    SciTech Connect (OSTI)

    Friedrich, S; Drury, O; Hall, J; Cantor, R

    2009-09-23

    We are developing superconducting tunnel junction (STJ) soft X-ray detectors for chemical analysis of dilute samples by fluorescence-detected X-ray absorption spectroscopy (XAS). Our 36-pixel Nb-based STJ spectrometer covers a solid angle {Omega}/4{pi} {approx} 10{sup -3}, offers an energy resolution of {approx}10-20 eV FWHM for energies up to {approx}1 keV, and can be operated at total count rates of {approx}10{sup 6} counts/s. For increased quantum efficiency and cleaner response function, we have now started the development of Ta-based STJ detector arrays. Initial devices modeled after our Nb-based STJs have an energy resolution below 10 eV FWHM for X-ray energies below 1 keV, and pulse rise time discrimination can be used to improve their response function for energies up to several keV. We discuss the performance of the Ta-STJs and outline steps towards the next-generation of large STJ detector arrays with higher sensitivity.

  8. Preliminary assessment of numerical data requirements TA-73 landfill Los Alamos, New Mexico

    SciTech Connect (OSTI)

    Not Available

    1993-11-19

    A numerical model, TOUGH2, was selected for describing liquid- and gas-phase flow in the unsaturated tuff underlying the TA-73 landfill. The model was selected primarily for its ability to simulate the significant mechanisms that may affect transport of contaminants through the vadose zone at the TA-73 landfill, including non-isothermal flow through fractured media. TOUGH2 is the best documented, verified, and validated model capable of performing the required simulations. The sensitivity analyses that were performed and describes in this report identified the input parameters that the selected numerical model is most sensitive to. The input parameters analyzed were saturated hydraulic conductivity, van Genuchten {alpha} and n, residual and saturated moisture contents, infiltration rate, fracture spacing and permeability, atmospheric pressure, and temperature. The sensitivity analyses were performed using a model grid that was designed to incorporate the regions in the landfill vicinity where contaminant transport is likely to occur and where the physical processes affecting flow and transport are the most dynamic. The sensitivity analyses performed suggest that the model is quite sensitive to a number of input parameters, including saturated hydraulic conductivity, the van Genuchten parameters {alpha} and n (for both the tuff matrix and fractures), fracture density and aperture, and atmospheric pressure. The results indicate that additional site-specific hydraulic properties and fracture data should be obtained before attempting to perform predictive, numerical simulations of gas- and liquid-phase flow beneath the landfill.

  9. Synthesis and magnetic properties of Ta/NdFeB-based composite microwires

    SciTech Connect (OSTI)

    Szary, P. Prigo, E. A.; Michels, A.; Luciu, I.; Duday, D.; Wirtz, T.; Choquet, P.

    2015-05-07

    Magnetic NdFeB-based microwire composites have been prepared by the direct current magnetron sputtering technique in a specifically designed sputtering chamber for thin-film deposition in wire geometry. As substrate wire material, we have employed steel and Ta. Annealing of the substrate wires during the deposition process was performed by ohmic heating through the application of a direct current. Samples were characterized by means of vibrating sample magnetometry (VSM) and scanning electron microscopy. Best properties have been encountered when using Ta wires as core (substrate) material. The VSM data show a dramatic impact of the current applied during the deposition process on the magnetic properties. For higher current values, i.e., higher annealing temperatures, the wires exhibit a reversal process that is typical for a two-phase system. Moreover, an increase of the coercive field (and remanent magnetization) is observed, which is ascribed to a modification of the magnetic phase present in the sample due to the annealing. We find an indication for the formation of a magnetic easy-axis direction which is azimuthally oriented around the wire axis.

  10. Polytypism, polymorphism, and superconductivity in TaSe2–xTex

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Luo, Huixia; Xie, Weiwei; Tao, Jing; Inoue, Hiroyuki; Gyenis, András; Krizan, Jason W.; Yazdani, Ali; Zhu, Yimei; Cava, Robert Joseph

    2015-03-03

    Polymorphism in materials often leads to significantly different physical properties - the rutile and anatase polymorphs of TiO₂ are a prime example. Polytypism is a special type of polymorphism, occurring in layered materials when the geometry of a repeating structural layer is maintained but the layer stacking sequence of the overall crystal structure can be varied; SiC is an example of a material with many polytypes. Although polymorphs can have radically different physical properties, it is much rarer for polytypism to impact physical properties in a dramatic fashion. Here we study the effects of polytypism and polymorphism on the superconductivitymore » of TaSe₂, one of the archetypal members of the large family of layered dichalcogenides. We show that it is possible to access 2 stable polytypes and 2 stable polymorphs in the TaSe2-xTex solid solution, and find that the 3R polytype shows a superconducting transition temperature that is between 6 and 17 times higher than that of the much more commonly found 2H polytype. Thus, the reason for this dramatic change is not apparent, but we propose that it arises either from a remarkable dependence of Tc on subtle differences in the characteristics of the single layers present, or from a surprising effect of the layer stacking sequence on electronic properties that instead are expected to be dominated by the properties of a single layer in materials of this kind.« less

  11. Polytypism, polymorphism, and superconductivity in TaSe2-xTex

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Luo, Huixia; Tao, Jing; Xie, Weiwei; Inoue, Hiroyuki; Gyenis, Andras; Krizan, Jason W.; Yazdani, Ali; Zhu, Yimei; Cava, R. J.

    2015-03-17

    Polymorphism in materials often leads to significantly different physical properties - the rutile and anatase polymorphs of TiO? are a prime example. Polytypism is a special type of polymorphism, occurring in layered materials when the geometry of a repeating structural layer is maintained but the layer stacking sequence of the overall crystal structure can be varied; SiC is an example of a material with many polytypes. Although polymorphs can have radically different physical properties, it is much rarer for polytypism to impact physical properties in a dramatic fashion. Here we study the effects of polytypism and polymorphism on the superconductivitymoreof TaSe?, one of the archetypal members of the large family of layered dichalcogenides. We show that it is possible to access 2 stable polytypes and 2 stable polymorphs in the TaSe2-xTex solid solution, and find that the 3R polytype shows a superconducting transition temperature that is between 6 and 17 times higher than that of the much more commonly found 2H polytype. The reason for this dramatic change is not apparent, but we propose that it arises either from a remarkable dependence of Tc on subtle differences in the characteristics of the single layers present, or from a surprising effect of the layer stacking sequence on electronic properties that instead are expected to be dominated by the properties of a single layer in materials of this kind.less

  12. The problem of intermixing of metals possessing no mutual solubility upon explosion welding (Cu-Ta, Fe-Ag, Al-Ta)

    SciTech Connect (OSTI)

    Greenberg, B.A.; Ivanov, M.A.; Rybin, V.V.; Elkina, O.A.; Antonova, O.V.; Patselov, A.M.; Inozemtsev, A.V.; Plotnikov, A.V.; Volkova, A.Yu.; Besshaposhnikov, Yu.P.

    2013-01-15

    On the basis of the results obtained for joints of dissimilar metals such as copper-tantalum and iron-silver, the reason of immiscible suspensions mixing upon explosion welding has been cleared out. It has been found that the interface (plain or wavy) is not smooth and contains inhomogeneities, namely, cusps and local melting zones. The role of granulating fragmentation providing partitioning of initial materials as a main channel of input energy dissipation has been revealed. It has been shown that in joints of metals possessing normal solubility the local melting zones are true solutions, but if metals possess no mutual solubility the local melting zones are colloidal solutions. Realization of either emulsion or suspension variant takes place. The results can be used in the development of new joints of metals possessing no mutual solubility. - Highlights: Black-Right-Pointing-Pointer Immiscible pairs Ta/Cu and Fe/Ag are welded successfully by explosive welding. Black-Right-Pointing-Pointer Fragmentation provides for partitioning as the main energy dissipation channel. Black-Right-Pointing-Pointer Immiscible metals form colloidal solid solutions during solidification. Black-Right-Pointing-Pointer Melting and boiling temperatures ratio determines the colloidal solution type. Black-Right-Pointing-Pointer Local melting zones being in suspension form enhance welds hardening.

  13. Chemical stability of highly (0001) textured Sm(CoCu){sub 5} thin films with a thin Ta capping layer

    SciTech Connect (OSTI)

    Zhao Haibao; Wang Hao; Liu Xiaoqi; Wang Jianping; Zhang Tao

    2011-04-01

    With the highest magnetocrystalline anisotropy constant (Ku) among practical magnetic materials, SmCo{sub 5} could be a very attractive candidate for future high areal density magnetic recording. However, its corrosion resistance is always a concern in recording media applications. In this paper, the chemical stability and microstructures of highly (0001) textured Sm(CoCu){sub 5} thin films with and without a 3 nm Ta capping layer were reported. For Sm(CoCu){sub 5} thin films without a capping layer, the coercivity decreases significantly (from 8kOe to 1kOe) within one month. Sm(CoCu){sub 5} thin films capped with a thin Ta layer (3 nm) behave differently. Even exposed to a laboratory environment (25 deg. C) over 3 years, the Ta-capped Sm(CoCu){sub 5} thin films are stable in terms of structural and magnetic properties, i.e., there were no changes in X-ray diffraction peaks and vibrating sample magnetometer hysteresis loops. Microstructure of Ta-capped Sm(CoCu){sub 5} thin films showed that Sm(CoCu){sub 5} formed a domelike particle assembly structure on a smooth Ru underlayer and were well covered by partially oxidized Ta capping layer, as shown by TEM cross-section micrographs. Accelerated corrosion treatment (130 deg. C, 95% relative humidity, 6 h) was performed on Ta-capped Sm(CoCu){sub 5} thin films. X-ray photoelectron spectroscopy (XPS) results showed that no Co was detected on the sample surface before the corrosion treatment, but strong XPS signals of CoOx and Co(OH)x were observed after treatment. Therefore, none of our Sm(CoCu){sub 5} thin films can pass the accelerated corrosion test. Hcp-phased CoPt-alloys are proposed as better capping materials for Sm(CoCu){sub 5} thin films in future high-density magnetic recording applications.

  14. EIS-0450: TransWest Express Transmission Project; Wyoming, Colorado, Utah, and Nevada

    Broader source: Energy.gov [DOE]

    This EIS, prepared jointly by DOE's Western Area Power Administration and the Department of the Interior's Bureau of Land Management (Wyoming State Office), evaluates the potential environmental impacts of granting a right-of-way for the TransWest Express Transmission Project and amending a land use plan. The project consists of an overhead transmission line that would extend approximately 725 miles from south-central Wyoming, through Colorado and Utah. Western proposes to be a joint owner of the project.

  15. TRANS4: a computer code calculation of solid fuel penetration of a concrete barrier. [LMFBR; GCFR

    SciTech Connect (OSTI)

    Ono, C. M.; Kumar, R.; Fink, J. K.

    1980-07-01

    The computer code, TRANS4, models the melting and penetration of a solid barrier by a solid disc of fuel following a core disruptive accident. This computer code has been used to model fuel debris penetration of basalt, limestone concrete, basaltic concrete, and magnetite concrete. Sensitivity studies were performed to assess the importance of various properties on the rate of penetration. Comparisons were made with results from the GROWS II code.

  16. Vehicle Technologies Office Merit Review 2014: Transportation Energy Transition Modeling and Analysis: the LAVE-Trans Model

    Broader source: Energy.gov [DOE]

    Presentation given by Oak Ridge National Laboratory at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about the LAVE-Trans...

  17. Synthesis of high-strength W-Ta ultrafine-grain composites

    SciTech Connect (OSTI)

    Ott, R. T.; Yang, X. Y.; Guyer, D. E.; Chauhan, S.; Sordelet, D. J.

    2015-09-30

    Bulk samples of an ultrafine-grained tungstentantalum composite alloy have been synthesized by consolidating mechanically milled composite powders. The grain growth during densification is limited due to the submicron-scale layering of the individual metals in the composite particles and the relatively low sintering temperature (1300 C). The ultrafine microstructure of the high-density (~99% theoretical density) samples leads to a high yield stress of ~3 GPa under quasi-static uniaxial compression. A tendency for Ta-rich solid-solution formation during densification was observed, and the high-temperature phase equilibria in the composite powders were examined further using high-energy x-ray diffraction at temperatures up to 1300 C.

  18. Preparation and photocatalytic activity for water splitting of Pt-Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays

    SciTech Connect (OSTI)

    Liu, Jing; Liu, Jiawen; Li, Zhonghua

    2013-02-15

    Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays were prepared by hydrothermal method from Ta{sub 2}O{sub 5} nanotube arrays, obtained by anodization of Ta foils, in Na{sub 2}CO{sub 3} solution at 150 Degree-Sign C. The as-synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), UV-vis diffuse reflectance spectra (UV-DRS) and X-ray photoelectron spectroscopy (XPS). Analysis results show that pyrochlore structure Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays have been successfully fabricated. The diameters and lengths of Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays are 50 nm and 4 {mu}m, respectively. The photocatalytic hydrogen production activities of the as-synthesized Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays are highly dependent on the hydrothermal reaction time and Na{sub 2}CO{sub 3} concentration, optimized reaction parameters are obtained. To further improve the photocatalytic activity for hydrogen evolution, Pt loaded Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays are prepared by photochemical reduction method. The Pt loaded samples exhibit much higher activity for hydrogen evolution than pure Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays. Moreover, the photocatalytic hydrogen properties are rather stable. - Graphical abstract: Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays were synthesized by hydrothermal method using Ta{sub 2}O{sub 5} nanotube arrays as a precursor. The loaded Pt enhances the photocatalytic activity for water splitting of Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays. Highlights: Black-Right-Pointing-Pointer Novel Na{sub 2}Ta{sub 2}O{sub 6} nanotube array films with pyrochlore structure were synthesized. Black-Right-Pointing-Pointer Na{sub 2}Ta{sub 2}O{sub 6} nanotube arrays are active for H{sub 2} evolution from aqueous CH{sub 3}OH solution. Black-Right-Pointing-Pointer The effect of hydrothermal conditions on photocatalytic activity was investigated. Black-Right-Pointing-Pointer Pt loading can improve the

  19. Measured Whole-House Performance of TaC Studios Test Home

    SciTech Connect (OSTI)

    Butler, T.; Curtis, O.; Stephenson, R.

    2013-12-01

    As part of the NAHB Research Center Industry Partnership, Southface partnered with TaC Studios, an Atlanta-based architecture firm specializing in residential and light commercial design, on the construction of a new test home in Atlanta, GA in the mixed humid climate. This home serves as a residence and home office for the firm's owners, as well as a demonstration of their design approach topotential and current clients. Southface believes the home demonstrates current best practices for the mixed-humid climate, including a building envelope featuring advanced air sealing details and low density spray foam insulation, glazing that exceeds ENERGY STAR requirements, and a high performance heating and cooling system. Construction quality and execution was a high priority for TaCStudios and was ensured by a third party review process. Post-construction testing showed that the project met stated goals for envelope performance, an air infiltration rate of 2.15 ACH50. The homeowners wished to further validate whole house energy savings through the project's involvement with Building America and this long-term monitoring effort. As a Building America test home, this homewas evaluated to detail whole house energy use, end use loads, and the efficiency and operation of the ground source heat pump and associated systems. Given that the home includes many non-typical end use loads including a home office, pool, landscape water feature, and other luxury features not accounted for in Building America modeling tools, these end uses were separately monitored todetermine their impact on overall energy consumption.

  20. Measured Whole-House Performance of TaC Studios Test Home

    SciTech Connect (OSTI)

    Butler, T.; Curtis, O.; Stephenson, R.

    2013-12-01

    As part of the NAHB Research Center Industry Partnership, Southface partnered with TaC Studios, an Atlanta-based architecture firm specializing in residential and light commercial design, on the construction of a new test home in Atlanta, GA, in the mixed humid climate. This home serves as a residence and home office for the firm's owners, as well as a demonstration of their design approach to potential and current clients. Southface believes the home demonstrates current best practices for the mixed-humid climate, including a building envelope featuring advanced air sealing details and low density spray foam insulation, glazing that exceeds ENERGY STAR requirements, and a high performance heating and cooling system. Construction quality and execution was a high priority for TaC Studios and was ensured by a third party review process. Post-construction testing showed that the project met stated goals for envelope performance, an air infiltration rate of 2.15 ACH50. The homeowners wished to further validate whole house energy savings through the project's involvement with Building America and this long-term monitoring effort. As a Building America test home, this home was evaluated to detail whole house energy use, end use loads, and the efficiency and operation of the ground source heat pump and associated systems. Given that the home includes many non-typical end use loads including a home office, pool, landscape water feature, and other luxury features not accounted for in Building America modeling tools, these end uses were separately monitored to determine their impact on overall energy consumption.

  1. Properties of Ta{sub 2}O{sub 5} thin films prepared by ion-assisted deposition

    SciTech Connect (OSTI)

    Farhan, Mansour S.; Zalnezhad, E.; Bushroa, A.R.

    2013-10-15

    Graphical abstract: - Highlights: • Investigating the effect of ion-beam parameters on optical properties. • Exploring the effect of ion-beam parameters on structural properties. • Studying XRD patterns of Ta{sub 2}O{sub 5} films deposited at different ion energies. - Abstract: Tantalum penta-oxide (Ta{sub 2}O{sub 5}) thin films were deposited onto highly polished and clean, fused silica glass substrates via ion beam-assisted deposition at room temperature using a high-vacuum coater equipped with an electron beam gun. The effects of ion beam parameters, oxygen flow rate, and deposition rate on the optical and structural properties as well as the stress of Ta{sub 2}O{sub 5} films were studied. It has been revealed that Ta{sub 2}O{sub 5} thin films deposited at 300 eV ion beam energy, 60 μA/cm{sup 2} ion current density, 20 sccm oxygen flow rate and 0.6 nm/s deposition rate demonstrated excellent optical, structural and compressive stress.

  2. Application of cluster-plus-glue-atom model to barrierless CuNiTi and CuNiTa films

    SciTech Connect (OSTI)

    Li, Xiaona, E-mail: lixiaona@dlut.edu.cn; Ding, Jianxin; Wang, Miao; Dong, Chuang [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024 (China); Chu, Jinn P. [Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan (China)

    2014-11-01

    To improve the thermal stability of copper and avoid its diffusion into surrounding dielectrics or interfacial reactions with them, the authors applied the cluster-plus-glue-atom model to investigate barrierless CuNiM (M?=?Ti or Ta) seed layers. The dissolution of the third element (Ti or Ta) in the Cu lattice with the aid of Ni significantly improved the thermal stability of the Cu seed layer. The appropriate M/Ni (M?=?Ti or Ta) ratio was selected to obtain a low resistivity: the resistivity was as low as 2.5??? cm for the (Ti{sub 1.5/13.5}Ni{sub 12/13.5}){sub 0.3}Cu{sub 99.7} film and 2.8??? cm for the (Ta{sub 1.1/13.1}Ni{sub 12/13.1}){sub 0.4}Cu{sub 99.6} film after annealing at 500?C for 1?h. After annealing at 500?C for 40?h, the two films remained stable without forming a Cu{sub 3}Si compound. The authors confirmed that the range of applications of the cluster-plus-glue-atom model could be extended. Therefore, a third element M with negative enthalpies of mixing with both Cu and Ni could be selected, under the premise that the mixing enthalpy of MNi is more negative than that of MCu.

  3. Visible Light Assisted Photocatalytic Hydrogen Generation by Ta2O5/Bi2O3, TaON/Bi2O3, and Ta3N5/Bi2O3 Composites

    SciTech Connect (OSTI)

    Adhikari, Shiba; Hood, Zachary D.; More, Karren Leslie; Ivanov, Ilia N.; Zhang, Lifeng; Gross, Michael; Lachgar, Abdou

    2015-06-15

    Composites comprised of two semiconducting materials with suitable band gaps and band positions have been reported to be effective at enhancing photocatalytic activity in the visible light region of the electromagnetic spectrum. Here, we report the synthesis, complete structural and physical characterizations, and photocatalytic performance of a series of semiconducting oxide composites. UV light active tantalum oxide (Ta2O5) and visible light active tantalum oxynitride (TaON) and tantalum nitride (Ta3N5) were synthesized, and their composites with Bi2O3 were prepared in situ using benzyl alcohol as solvent. The composite prepared using equimolar amounts of Bi2O3 and Ta2O5 leads to the formation of the ternary oxide, bismuth tantalate (BiTaO4) upon calcination at 1000 °C. The composites and single phase bismuth tantalate formed were characterized by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET) surface area measurement, scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–Vis diffuse reflectance spectroscopy, and photoluminescence. The photocatalytic activities of the catalysts were evaluated for generation of hydrogen using aqueous methanol solution under visible light irradiation (λ ≥ 420 nm). The results show that as-prepared composite photocatalysts extend the light absorption range and restrict photogenerated charge-carrier recombination, resulting in enhanced photocatalytic activity compared to individual phases. The mechanism for the enhanced photocatalytic activity for the heterostructured composites is elucidated based on observed activity, band positions calculations, and photoluminescence data.

  4. Adequacy of the regulatory oversight of the Trans-Alaska pipeline and terminal

    SciTech Connect (OSTI)

    Not Available

    1990-03-01

    The Exxon Valdez spill abruptly brought to the nation's attention the risks of transporting crude oil. While oil tanker transportation received many of the headlines, the safety of pipelines carrying oil and the terminals that store it have also been called into question. GAO testified on the adequacy of regulatory oversight of the 800-mile Trans-Alaska Pipeline System and the terminal at Valdez, Alaska. This paper reports increased and coordinated regulatory oversight as a major component of an effective operational and emergency response strategy for the pipeline. The current lack of comprehensive and systematic oversight is of particular concern because of recent revelations of significant corrosion problems in the pipeline.

  5. HIGH-ENERGY NEUTRINO AND GAMMA-RAY TRANSIENTS FROM TRANS-RELATIVISTIC SUPERNOVA SHOCK BREAKOUTS

    SciTech Connect (OSTI)

    Kashiyama, Kazumi; Gao, Shan; Meszaros, Peter [Center for Particle and Gravitational Astrophysics, Department of Astronomy and Astrophysics, Department of Physics, Pennsylvania State University, University Park, PA 16802 (United States); Murase, Kohta; Horiuchi, Shunsaku, E-mail: kzk15@psu.edu [CCAPP and Department of Physics, Ohio State University, 191 W. Woodruff Avenue, Columbus, OH 43210 (United States)

    2013-05-20

    Trans-relativistic shocks that accompany some supernovae (SNe) produce X-ray burst emissions as they break out in the dense circumstellar medium around the progenitors. This phenomenon is sometimes associated with peculiar low-luminosity gamma-ray bursts (LL GRBs). Here, we investigate the high-energy neutrino and gamma-ray counterparts of such a class of SNe. Just beyond the shock breakout radius, particle acceleration in the collisionless shock starts to operate in the presence of breakout photons. We show that protons may be accelerated to sufficiently high energies and produce high-energy neutrinos and gamma rays via the photomeson interaction. These neutrinos and gamma rays may be detectable from {approx}< 10 Mpc away by IceCube/KM3Net as multi-TeV transients almost simultaneously with the X-ray breakout, and even from {approx}< 100 Mpc away with follow-up observations by the Cherenkov Telescope Array using a wide-field sky monitor like Swift as a trigger. A statistical technique using a stacking approach could also be possible for the detection, with the aid of the SN optical/infrared counterparts. Such multi-messenger observations offer the possibility to probe the transition of trans-relativistic shocks from radiation-mediated to collisionless ones, and would also constrain the mechanisms of particle acceleration and emission in LL GRBs.

  6. Strain control magnetocrystalline anisotropy of Ta/FeCo/MgO heterostructures

    SciTech Connect (OSTI)

    Ong, P. V.; Kioussis, Nicholas; Amiri, P. Khalili; Wang, K. L.; Carman, Gregory P.

    2015-05-07

    Using ab initio electronic structure calculations, we have investigated the effect of epitaxial strain on magnetocrystalline anisotropy (MCA) of Ta/FeCo/MgO heterostructure. At small expansive strains on the FeCo layer, the system exhibits perpendicular MCA (PMA). Strain not only has a profound effect on the value of MCA but also induces a switching of magnetic easy axis. Analysis of the energy- and k-resolved distribution of orbital characters of the minority-spin band reveals that a significant contribution to PMA at zero strain arises from the spin-orbit coupling between occupied d{sub x{sup 2}−y{sup 2}} and unoccupied d{sub xy} states, derived from Fe at the FeCo/MgO interface. The strain effect is attributed to strain-induced shifts of spin-orbit coupled d-states. Our work demonstrates that strain engineering can open a viable pathway towards tailoring magnetic properties for spintronic applications.

  7. Progress in Studies of Electron-Cloud-Induced Optics Distortions at CesrTA

    SciTech Connect (OSTI)

    Crittenden, James; Calvey, Joseph; Dugan, Gerald; Kreinick, David; Leong, Zhidong; Livezey, Jesse; Palmer, Mark; Rubin, David; Sagan, David; Furman, Miguel; Penn, Gregory; Venturini, Marco; Harkay, Katherine; Holtzapple, Robert; Pivi, Mauro; Wang, Lanfa; /SLAC

    2012-06-25

    The Cornell Electron Storage Ring Test Accelerator (CesrTA) program has included extensive measurements of coherent betatron tune shifts for a variety of electron and positron beam energies, bunch population levels, and bunch train configurations. The tune shifts have been shown to result primarily from the interaction of the beam with the space-charge field of the beam-induced low-energy electron cloud in the vacuum chamber. Comparison to several advanced electron cloud simulation codes has allowed determination of the sensitivity of these measurements to physical parameters characterizing the synchrotron radiation flux, the production of photo-electrons on the vacuum chamber wall, the beam emittance, lattice optics, and the secondary-electron yield model. We report on progress in understanding the cloud buildup and decay mechanisms in magnetic fields and in field-free regions, addressing quantitatively the precise determination of the physical parameters of the modeling. Validation of these models will serve as essential input in the design of damping rings for future high-energy linear colliders.

  8. Competing decay modes of a high-spin isomer in the proton-unbound nucleus ¹⁵⁸Ta*

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Carroll, R. J.; Page, R. D.; Joss, D. T.; Uusitalo, J.; Darby, I. G.; Andgren, K.; Cederwall, B.; Eeckhaudt, S.; Grahn, T.; Gray-Jones, C.; et al

    2015-01-01

    An isomeric state at high spin and excitation energy was recently observed in the proton-unbound nucleus 158Ta. This state was observed to decay by both α and γ decay modes. The large spin change required to decay via γ-ray emission incurs a lifetime long enough for α decay to compete. The α decay has an energy of 8644(11) keV, which is among the highest observed in the region, a partial half-life of 440(70) μs and changes the spin by 11ℏ. In this study, additional evidence supporting the assignment of this α decay to the high-spin isomer in 158Ta will bemore » presented.« less

  9. Electronic structure reconstruction across the antiferromagnetic transition in TaFe₁̣₂₃Te₃ spin ladder

    SciTech Connect (OSTI)

    Xu, Min; Wang, Li -Min; Peng, Rui; Ge, Qing -Qin; Chen, Fei; Ye, Zi -Rong; Zhang, Yan; Chen, Su -Di; Xia, Miao; Liu, Rong -Hua; Arita, M.; Shimada, K.; Namatame, H.; Taniguchi, M.; Matsunami, M.; Kimura, S.; Shi, Ming; Chen, Xian -Hui; Yin, Wei -Guo; Ku, Wei; Xie, Bin -Ping; Feng, Dong -Lai

    2015-02-01

    With angle-resolved photoemission spectroscopy, we studied the electronic structure of TaFe₁̣₂₃Te₃, a two-leg spin ladder compound with a novel antiferromagnetic ground state. Quasi-two-dimensional Fermi surface is observed, with sizable inter-ladder hopping. Moreover, instead of observing an energy gap at the Fermi surface in the antiferromagnetic state, we observed the shifts of various bands. Combining these observations with density-functional-theory calculations, we propose that the large scale reconstruction of the electronic structure, caused by the interactions between coexisting itinerant electrons and local moments, is most likely the driving force of the magnetic transition. Thus TaFe₁̣₂₃Te₃ serves as a simpler platform that contains similar ingredients as the parent compounds of iron-based superconductors.

  10. All-metallic electrically gated 2H-TaSe{sub 2} thin-film switches and logic circuits

    SciTech Connect (OSTI)

    Renteria, J.; Jiang, C.; Yan, Z.; Samnakay, R.; Goli, P.; Pope, T. R.; Salguero, T. T.; Wickramaratne, D.; Lake, R. K.; Khitun, A. G.; Balandin, A. A.

    2014-01-21

    We report the fabrication and performance of all-metallic three-terminal devices with tantalum diselenide thin-film conducting channels. For this proof-of-concept demonstration, the layers of 2H-TaSe{sub 2} were exfoliated mechanically from single crystals grown by the chemical vapor transport method. Devices with nanometer-scale thicknesses exhibit strongly non-linear current-voltage characteristics, unusual optical response, and electrical gating at room temperature. We have found that the drain-source current in thin-film 2H-TaSe{sub 2}Ti/Au devices reproducibly shows an abrupt transition from a highly resistive to a conductive state, with the threshold tunable via the gate voltage. Such current-voltage characteristics can be used, in principle, for implementing radiation-hard all-metallic logic circuits. These results may open new application space for thin films of van der Waals materials.

  11. Electronic structure reconstruction across the antiferromagnetic transition in TaFe₁̣₂₃Te₃ spin ladder

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Xu, Min; Wang, Li -Min; Peng, Rui; Ge, Qing -Qin; Chen, Fei; Ye, Zi -Rong; Zhang, Yan; Chen, Su -Di; Xia, Miao; Liu, Rong -Hua; et al

    2015-02-01

    With angle-resolved photoemission spectroscopy, we studied the electronic structure of TaFe₁̣₂₃Te₃, a two-leg spin ladder compound with a novel antiferromagnetic ground state. Quasi-two-dimensional Fermi surface is observed, with sizable inter-ladder hopping. Moreover, instead of observing an energy gap at the Fermi surface in the antiferromagnetic state, we observed the shifts of various bands. Combining these observations with density-functional-theory calculations, we propose that the large scale reconstruction of the electronic structure, caused by the interactions between coexisting itinerant electrons and local moments, is most likely the driving force of the magnetic transition. Thus TaFe₁̣₂₃Te₃ serves as a simpler platform that containsmore » similar ingredients as the parent compounds of iron-based superconductors.« less

  12. Improvement of the photoluminescent intensity of ZnTa{sub 2}O{sub 6}:Pr{sup 3+} phosphor

    SciTech Connect (OSTI)

    Noto, L.L. Ntwaeaborwa, O.M.; Yagoub, M.Y.A.; Swart, H.C.

    2014-07-01

    Highlights: The optimal luminescence intensity was obtained for 0.4 mol% Pr{sup 3+} doped ZnTa{sub 2}O{sub 6}. The ZnTa{sub 2}O{sub 6}:Pr{sup 3+} has a colour index matching an ideal red emission. The cross relaxation process led to a decrease in red emission at higher Pr{sup 3+} concentrations. The blue emission continues to increase at higher Pr{sup 3+} concentrations. The persistent luminescent increases with an increase in Pr{sup 3+} concentration. - Abstract: A red emitting ZnTa{sub 2}O{sub 6}:Pr{sup 3+} phosphor with Commission Internationale de lEclairage coordinates that match those of an ideal red emission was prepared by solid state chemical reaction. X-ray diffraction confirmed that a pure orthorhombic phase of ZnTa{sub 2}O{sub 6} was crystallized. A homogeneous distribution of the Pr{sup 3+} ions was confirmed from the analysis of the time of flight secondary ion mass spectroscopy overlay images. In addition to the reflectance at 259 nm associated with band-to-band absorption, minor reflectance peaks associated with f-f transitions of Pr{sup 3+} were observed at 420500 nm. The main red emission peak was split into minor peaks located at 608, 619 and 639 nm that were assigned to {sup 1}D{sub 2} ? {sup 3}H{sub 4}, {sup 3}P{sub 0} ? {sup 3}H{sub 6} and {sup 3}P{sub 0} ? {sup 3}F{sub 2} transitions of Pr{sup 3+}, respectively. With increasing concentration of Pr{sup 3+}, a relatively weak blue emission was observed at 488 nm and this phenomenon maybe attributed to virtual charge transfer or/and inter cross relaxation effects. The decay characteristics of the persistent emission were also calculated.

  13. EP-AREAG-PLAN-1248, R.0 TA-54 Area G Nitrate-Salt Waste Container Response Instructions

    Office of Environmental Management (EM)

    EP-AREAG-PLAN-1248, R.0 TA-54 Area G Nitrate-Salt Waste Container Response Instructions Effective Date: 5/28/2014 The Responsible Manager has determined that the following organizations' review/concurrence is required for the initial document and for major revisions a same type and level review is required. Review documentation is contained in the Document History File: EWMO Engineering LANL TRU Programs - Shipping and Safe Storage Disposition LANL TRU Programs - Drum Disposition Project LANL

  14. Significant enhancement of compositional and superconducting homogeneity in Ti rather than Ta-doped Nb3Sn

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Tarantini, C.; Sung, Z. -H.; Lee, P. J.; Ghosh, A. K.; Larbalestier, D. C.

    2016-01-25

    Nb3Sn wires are now very close to their final optimization but despite its classical nature, detailed understanding of the role of Ta and Ti doping in the A15 is not fully understood. Long thought to be essentially equivalent in their influence on Hc2, they were interchangeably applied. Here we show that Ti produces significantly more homogeneous chemical and superconducting properties. Despite Ta-doped samples having a slightly higher Tc onset in zero-field, they always have a wider Tc-distribution. In particular, whereas the Ta-doped A15 has a Tc-distribution extending from 18 down to 5-6 K (the lowest expected Tc for the binarymore » A15 phase), the Ti-doped samples have no A15 phase with Tc below ~12 K. The much narrower Tc distribution in the Ti-doped samples has a positive effect on their in-field Tc-distribution too, leading to an extrapolated μ0Hc2(0) 2 Tesla larger than the Ta-doped one. Ti-doping also appears to be very homogeneous even when the Sn content is reduced in order to inhibit breakdown of the diffusion barriers in very high Jc conductors. As a result, the enhanced homogeneity of the Ti-doped samples appears to result from its assistance of rapid diffusion of Sn into the filaments and by its incorporation into the A15 phase interchangeably with Sn on the Sn sites of the A15 phase.« less

  15. Synthesis of 4-substituted-trans-1, 2-diaminocyclohexyl polyaminocarboxylate metal chelating agents for the preparation of stable radiometal antibody immunoconjugates for therapy and SPECT and PET imaging

    DOE Patents [OSTI]

    Mease, R.C.; Mausner, L.F.; Srivastava, S.C.

    1994-03-08

    Cyclo agents are described which are useful in forming antibody-metal conjugates which are used for diagnostic and therapeutic purposes. New compounds and processes of forming these compounds are disclosed including 4-haloacetamido-trans-1,2diaminocyclohexyl polyaminocarboxylate and 4-isothiocyanato-trans-1,2diamino cyclohexane-N,N,N',N'-tetra acetic acid. No Drawings

  16. Synthesis of 4-substituted-trans-1, 2-diaminocyclohexyl polyaminocarboxylate metal chelating agents for the preparation of stable radiometal antibody immunoconjugates for therapy and spect and pet imaging

    DOE Patents [OSTI]

    Mease, Ronnie C.; Mausner, Leonard F.; Srivastava, Suresh C.

    1994-01-01

    Cyclo agents useful in forming antibody-metal conjugates useful for diagnostic and therapeutic purposes. New compounds and processes of forming these compounds are disclosed including 4-haloacetamido-trans-1,2-diaminocyclohexyl polyaminocarboxylate and 4-isothiocyanato-trans-1,2-diamino cyclohexane-N,N,N',N'-tetra acetic acid.

  17. POTENTIAL EVIDENCE FOR THE ONSET OF ALFVÉNIC TURBULENCE IN TRANS-EQUATORIAL CORONAL LOOPS

    SciTech Connect (OSTI)

    De Moortel, I.; Threlfall, J.; McIntosh, S. W.; Bethge, C.; Liu, J. E-mail: mscott@ucar.edu

    2014-02-20

    This study investigates Coronal Multi-channel Polarimeter Doppler-shift observations of a large, off-limb, trans-equatorial loop system observed on 2012 April 10-11. Doppler-shift oscillations with a broad range of frequencies are found to propagate along the loop with a speed of about 500 km s{sup –1}. The power spectrum of perturbations travelling up from both loop footpoints is remarkably symmetric, probably due to the almost perfect north-south alignment of the loop system. Compared to the power spectrum at the footpoints of the loop, the Fourier power at the apex appears to be higher in the high-frequency part of the spectrum than expected from theoretical models. We suggest this excess high-frequency power could be tentative evidence for the onset of a cascade of the low-to-mid frequency waves into (Alfvénic) turbulence.

  18. Radionuclide contaminant analysis of small mammals at Area G, TA-54, Los Alamos National Laboratory, 1995

    SciTech Connect (OSTI)

    Bennett, K.; Biggs, J.; Fresquez, P.

    1997-01-01

    At Los Alamos National Laboratory, small mammals were sampled at two waste burial sites (Site 1-recently disturbed and Site 2-partially disturbed) at Area G, Technical Area 54 and a control site on Frijoles Mesa (Site 4) in 1995. Our objectives were (1) to identify radionuclides that are present within surface and subsurface soils at waste burial sites, (2) to compare the amount of radionuclide uptake by small mammals at waste burial sites to a control site, and (3) to identify if the primary mode of contamination to small mammals is by surface contact or ingestion/inhalation. Three composite samples of at least rive animals per sample were collected at each site. Pelts and carcasses of each animal were separated and analyzed independently. Samples were analyzed for {sup 241}Am, {sup 90}Sr , {sup 238}Pu, {sup 239}Pu, total U, {sup 137}Cs, and {sup 3}H. Significantly higher (parametric West at p=0.05) levels of total U, {sup 241}Am, {sup 238}Pu and {sup 239}Pu were detected in pelts than in carcasses of small mammals at TA-54. Concentrations of other measured radionuclides in carcasses were nearly equal to or exceeded the mean concentrations in the pelts. Our results show higher concentrations in pelts compared to carcasses, which is similar to what has been found at waste burial/contaminated sites outside of Los Alamos National Laboratory. Site 1 had a significantly higher (alpha=0.05, P=0.0125) mean tritium concentration in carcasses than Site 2 or Site 4. In addition Site 1 also had a significantly higher (alpha=0.05, p=0.0024) mean tritium concentration in pelts than Site 2 or Site 4. Site 2 had a significantly higher (alpha=0.05, P=0.0499) mean {sup 239}Pu concentration in carcasses than either Site 1 or Site 4.

  19. Photocatalytic hydrogen production using visible-light-responsive Ta{sub 3}N{sub 5} photocatalyst supported on monodisperse spherical SiO{sub 2} particulates

    SciTech Connect (OSTI)

    Liu, Xiaoming; Zhao, Lan; Domen, Kazunari; Takanabe, Kazuhiro

    2014-01-01

    Graphical abstract: A simple and effective solgel process followed by nitridation in an NH{sub 3} flow has been developed to deposit Ta{sub 3}N{sub 5} semiconductor photocatalyst layers onto monodisperse spherical SiO{sub 2} particles. The obtained Ta{sub 3}N{sub 5}/SiO{sub 2} particles maintain an original spherical morphology of SiO{sub 2} and a sub-micrometer size with a narrow size distribution and without aggregation. The presence of SiO{sub 2} support shows at least no detrimental effects on photocatalytic activity, but tunes the secondary particle size to control dispersibility of the photocatalyst in the solution. - Highlights: Fine nanoparticles of Ta{sub 3}N{sub 5} were immobilized on the surfaces of SiO{sub 2} giving SiO{sub 2}@Ta{sub 3}N{sub 5} coreshell spheres successfully produced H{sub 2} from methanol solution under visible light. The presence of support (SiO{sub 2}) ensures the dispersion of the particulate in solution maintaining high photocatalytic activity of Ta{sub 3}N{sub 5}. The obtained supported photocatalyst gives uniform size distribution and control the degree of dispersibility in the solution, which may control nature of light absorption and reflection of the photoreactor. - Abstract: Fine nanoparticles of Ta{sub 3}N{sub 5} (1020 nm) were synthesized on the surfaces of SiO{sub 2} spheres with a diameter of ?550 nm. A solgel method was used to modify the surface of SiO{sub 2} with Ta{sub 2}O{sub 5} from TaCl{sub 5} dissolved in ethanol in the presence of citric acid and polyethylene glycol. The resulting oxide composites were treated in an NH{sub 3} flow at 1123 K to form coreshell structured Ta{sub 3}N{sub 5}/SiO{sub 2} sub-microspheres. The obtained samples were characterized using powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectra (EDX), transmission electron microscopy (TEM), and photocatalytic activity

  20. Novel defect pyrochlores ABi/sub 2/B/sub 5/O/sub 16/ (A = Cs, Rb; B = Ta, Nb)

    SciTech Connect (OSTI)

    Ehlert, M.K., Greedan, J.E.; Subramanian, M.A.

    1988-07-01

    The crystal structures of three oxides with compositions CsBi/sub 2/Nb/sub 5/O/sub 16/, CsBi/sub 2/Ta/sub 5/O/sub 16/, and RbBi/sub 2/Ta/sub 5/O/sub 16/ have been determined from powder neutron diffraction data. A common structure of the defect pyrochlore types has been found. Atomic positions in space group Fd3m are 3.2 O and 3.2 Cs(Rb) in 8b, 6.4 Bi in 16d, 16 Ta(Nb) in 16c, and 48 O in 48f. There is some evidence that the Rb atoms actually occupy 32e sites. On electrostatic grounds it is highly unlikely that the Cs(Rb) and O atoms are randomly distributed in 8b. Evidence for short-range order is apparent in the X-ray powder diffraction data. Cell constants are 10.528(1) A (Cs, Nb), 10.504(1) A (Cs, Ta), and 10.510(2) A (Rb, Ta), respectively, with 48f x parameters 0.3139(2) (Cs, Nb), 0.3152(2) (Cs, Ta), and 0.3153(2) (Rb, Ta). Isotropic temperature factors for the 8b and 16d site atoms ranged from 3 to 6 (A)/sup 2/. These large values suggest anharmonic behavior or high mobility for some of the ions. Evidence for this is found in the presence of significant dielectric loss effects in all of the compounds studied.

  1. Structure of Mesita del Buey at TA-54, Los Alamos National Laboratory, New Mexico

    SciTech Connect (OSTI)

    Reneau, S.L.; Broxton, D.E.; Carney, J.S.; LaDelfe, C.

    1998-04-23

    The geological structure of Mesita del Buey at Technical Area 54 (TA-54) was examined using precise surveying of the contact between units 1v and 2 of the Tshirege Member of the Bandelier Tuff at 3.5 km along the north wall of Pajarito Canyon and 0.6 km along the north wall of a tributary to Canada del Buey. Estimated structure contours on this contact indicate typical strikes of N40E to N70E along this part of Mesita del Buey, although the apparent strike of the tuff is E-W at the western part of the survey. Typical dips are 1.0{degree} to 2.0{degree} to the east or southeast, with an estimated maximum dip of 3.2{degree} near the west end of Material Disposal Area G. Thirty seven faults with vertical displacements of 5 to 65 cm were observed in outcrop along the Pajarito Canyon traverse, and, due to the incomplete exposure of the unit 1v-unit 2 contact, many more faults of this magnitude undoubtedly exist. The faults have a wide range in strike and have either down-to-the-west and down-to-the-east components of offset, although about 65% of the observed displacement is down-to-the-west or northwest. These faults are not clearly associated with major fault zones, indicated by the general absence of larger-scale offsets or inflections along the unit 1v-unit 2 contact in areas where the small-scale faults were observed; they may instead record distributed secondary deformation across the Pajarito Plateau associated with large earthquakes on the main Pajarito fault zone 8--11 km to the west, or perhaps other faults in the region. The survey data also suggest that a 150--250 m wide zone of greater magnitude faulting is present near the west end of the traverse associated with a horst-and-graben structure displaying about 1.5--3.5 m of offset on individual faults, although the total amount of offset across this structure and its orientation are not known.

  2. Ambient Air Radionuclide Concentrations at and near TA-50 from 2003 through the First Quarter of 2004

    SciTech Connect (OSTI)

    K.W. Jacobson; C.F. Eberhart

    2005-09-05

    The Meteorology and Air Quality (MAQ) group at Los Alamos National Laboratory maintains and operates a large network of environmental air samplers called AIRNET. Some of these samplers are located near Material Disposal Area C at TA-50, a low-level radioactive waste burial site in the semiarid environment of the Pajarito Plateau, near Los Alamos. AIRNET sampling media consist of a filter and silica gel. They are exchanged once every 2 weeks. Presented are 5 months of air sampling results for 5 stations operating in the vicinity of Material Disposal Area C.

  3. Application of the Hartmann-Tran profile to precise experimental data sets of C?H?

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Forthomme, D.; Cich, M. J.; Twagirayezu, S.; Hall, G. E.; Sears, T. J.

    2015-06-25

    Self- and nitrogen-broadened line shape data for the Pe(11) line of the ?? + ?? band of acetylene, recorded using a frequency comb-stabilized laser spectrometer, have been analyzed using the HartmannTran profile (HTP) line shape model in a multispectrum fitting. In total, the data included measurements recorded at temperatures between 125 K and 296 K and at pressures between 4 and 760 Torr. New, sub-Doppler, frequency comb-referenced measurements of the positions of multiple underlying hot band lines have also been made. These underlying lines significantly affect the Pe(11) line profile at temperatures above 240 K and poorly known frequencies previouslymoreintroduced errors into the line shape analyses. The behavior of the HTP model was compared to the quadratic speed dependent Voigt profile (QSDVP) expressed in the frequency and time domains. A parameter uncertainty analysis was carried out using a Monte Carlo method based on the estimated pressure, transmittance and frequency measurement errors. From the analyses, the Pe(11) line strength was estimated to be 1.2014(50) 10-20 in cm.molecules? units at 296 K with the standard deviation in parenthesis. For analyzing these data, we found that a reduced form of the HTP, equivalent to the QSDVP, was most appropriate because the additional parameters included in the full HTP were not well determined. As a supplement to this work, expressions for analytic derivatives and a lineshape fitting code written in Matlab for the HTP are available.less

  4. Floodplain Assessment for the Proposed Engineered Erosion Controls at TA-72 in Lower Sandia Canyon, Los Alamos National Laboratory

    SciTech Connect (OSTI)

    Hathcock, Charles D.

    2012-08-27

    Los Alamos National Laboratory (LANL) is preparing to implement engineering controls in Sandia Canyon at Technical Area (TA) 72. Los Alamos National Security (LANS) biologists conducted a floodplain determination and this project is located within a 100-year floodplain. The proposed project is to rehabilitate the degraded channel in lower Sandia Canyon where it crosses through the outdoor firing range at TA-72 to limit the loss of sediment and dissipate floodwater leaving LANL property (Figure 1). The proposed construction of these engineered controls is part of the New Mexico Environment Department's (NMED) approved LANL Individual Storm Water Permit. The purpose of this project is to install storm water controls at Sandia Watershed Site Monitoring Area 6 (S-SMA-6). Storm water controls will be designed and installed to meet the requirements of NPDES Permit No. NM0030759, commonly referred to as the LANL Individual Storm Water Permit (IP). The storm water control measures address storm water mitigation for the area within the boundary of Area of Concern (AOC) 72-001. This action meets the requirements of the IP for S-SMA-6 for storm water controls by a combination of: preventing exposure of upstream storm water and storm water generated within the channel to the AOC and totally retaining storm water falling outside the channel but within the AOC.

  5. Polytypism, polymorphism, and superconductivity in TaSe2–xTex

    SciTech Connect (OSTI)

    Luo, Huixia; Xie, Weiwei; Tao, Jing; Inoue, Hiroyuki; Gyenis, András; Krizan, Jason W.; Yazdani, Ali; Zhu, Yimei; Cava, Robert Joseph

    2015-03-03

    Polymorphism in materials often leads to significantly different physical properties - the rutile and anatase polymorphs of TiO₂ are a prime example. Polytypism is a special type of polymorphism, occurring in layered materials when the geometry of a repeating structural layer is maintained but the layer stacking sequence of the overall crystal structure can be varied; SiC is an example of a material with many polytypes. Although polymorphs can have radically different physical properties, it is much rarer for polytypism to impact physical properties in a dramatic fashion. Here we study the effects of polytypism and polymorphism on the superconductivity of TaSe₂, one of the archetypal members of the large family of layered dichalcogenides. We show that it is possible to access 2 stable polytypes and 2 stable polymorphs in the TaSe2-xTex solid solution, and find that the 3R polytype shows a superconducting transition temperature that is between 6 and 17 times higher than that of the much more commonly found 2H polytype. Thus, the reason for this dramatic change is not apparent, but we propose that it arises either from a remarkable dependence of Tc on subtle differences in the characteristics of the single layers present, or from a surprising effect of the layer stacking sequence on electronic properties that instead are expected to be dominated by the properties of a single layer in materials of this kind.

  6. UNITED STATES ATOMIC ENERGY COMMISSION SAC200063~~0oooo Frank K. Pittman, Director, /Division of Waste Management and Trans-

    Office of Legacy Management (LM)

    SAC200063~~0oooo .- Frank K. Pittman, Director, /Division of Waste Management and Trans- portation, Headquarters CONTAMIWATRD EE-AEC-OWNED OR IEASED FACILITIES This memorandum responds to your TWX dated October 30, 1973, requesting certain information on the above subject. Unfortunately, some of the documentation necessary to answer your queries is no Longer available due to the records disposal program or the agreements pre- vailing at the time of release or transfer of the facilities. From

  7. Structural and thermal studies of H{sub 2}La{sub 2/3}Ta{sub 2}O{sub 7}, a protonated layered perovskite

    SciTech Connect (OSTI)

    Le Berre, F.; Crosnier-Lopez, M.P.; Fourquet, J.L.

    2006-04-13

    We have synthesised the new protonated layered perovskite H{sub 2}La{sub 2/3}Ta{sub 2}O{sub 7} which is related to the Ruddlesden-Popper family. This compound is obtained by ionic exchange starting from Li{sub 2}La{sub 2/3}Ta{sub 2}O{sub 7} maintained in dilute HNO{sub 3} at 60 deg. C. Thermal X-ray diffraction and DTA/TGA revealed interesting dehydration properties with formation of a layered anhydrous phase leading at higher temperature (1550 deg. C) to La{sub 1/3}TaO{sub 3}. This latter compound exhibits the original lanthanum ordering expected similarly to that of the Li form, while at 900 deg. C a metastable form, presenting a disordered La distribution, is observed.

  8. Transformation of cis- and trans-2,3-dimethyloxiranes on a Pd/SiO{sub 2} catalyst

    SciTech Connect (OSTI)

    Fasi, A.; Notheisz, F.; Bartok, M.

    1997-04-01

    The transformation of cis- and trans-2,3-dimethyloxiranes on a Pd/SiO{sub 2} catalyst, leading to the formation of 2-butanone and 2-butanol, was studied in hydrogen and deuterium atmosphere. The effect of hydrogen and deuterium atmosphere. The effect of hydrogen pressure (1.3-100 kPa) and temperature (323-423 K) on the reaction rate was also measured. The transformation of the two stereoisomers involves different mechanisms. In the case of the cis-isomer, hydrogen participates in the cleavage of the C-O bond and different surface species belong to the two products. In the case of the trans-isomer, ring opening by hydrogen (the formation of 2-butanol) is less significant and the main reaction is intramolecular migration leading to the formation of 2-butanone. Considering the geometry of the adsorbed species, cis-2,3-dimethyloxirane is most probably adsorbed on the surface of the Pd catalyst in a planar manner, while the adsorption of the trans-isomer is intermediate between edgewise and planar adsorption model. 18 refs., 3 figs., 3 tabs.

  9. Application to Export Electric Energy OE Docket No. EA-216-C TransAlta Energy Marketing (U.S) Inc Sierra Club Withdrawal Motion

    Broader source: Energy.gov [DOE]

    Withdrawal of Sierra Club motion to intervene on the application to export electric energy OE Docket No. EA-216-C made by TransAlta Energy Marketing (U.S) Inc.

  10. Signature-Dependent Electromagnetic Transition Rates in the {pi}h{sub 11/2} Rotational Sequence of {sub 73}{sup 167}Ta

    SciTech Connect (OSTI)

    R. Chapman; K.-M. Spohr; M.B. Smith; R.A. Bark; G.J. Campbell; G.B. Hagemann; N. Keeley; D.J. Middleton; H. Ryde; P.O. Tjom

    1999-12-31

    Excited states in {sup 167}Ta, populated in the {sup 141}Pr({sup 30}Si, 4n){sup 167}Ta reaction, have been studied using the NORDBALL Ge detector array. For the {pi}h{sub 11/2}[514]{sub 2}{sup 9}{sup -} decay sequence, strong signature-dependent effects in the transition quadrupole moment ratio, Q{sub 1}(I {yields} I - 1)/Q{sub 2}(I {yields} I - 2), have been observed over the spin range {sub 2}{sup 21}{<=}I{<=}{sub 2}{sup 39} which encompasses a BC neutron alignment. This is interpreted as strong evidence for departure from axial symmetry.

  11. Signature-dependent electromagnetic transition rates in the {pi}h{sub 11/2} rotational sequence of {sub 73}{sup 167}Ta

    SciTech Connect (OSTI)

    Chapman, R.; Spohr, K.-M.; Smith, M. B.; Campbell, G. J.; Middleton, D. J.; Bark, R. A.; Ryde, H.; Hagemann, G. B.; Keeley, N.; Tjoem, P. O.

    1999-11-16

    Excited states in {sup 167}Ta, populated in the {sup 141}Pr({sup 30}Si,4n){sup 167}Ta reaction, have been studied using the NORDBALL Ge detector array. For the {pi}h{sub 11/2}[514]9/2{sup -} decay sequence, strong signature-dependent effects in the transition quadrupole moment ratio, Q{sub 1}(I{yields}I-1)/Q{sub 2}(I{yields}I-2), have been observed over the spin range 21/2{<=}I{<=}39/2 which encompasses a BC neutron alignment. This is interpreted as strong evidence for departure from axial symmetry.

  12. Synthesis, properties and phase transitions of pyrochlore- and fluorite-like Ln{sub 2}RMO{sub 7} (Ln = Sm, Ho; R = Lu, Sc; M = Nb, Ta)

    SciTech Connect (OSTI)

    Shlyakhtina, A.V.; Belov, D.A.; Pigalskiy, K.S.; Shchegolikhin, A.N.; Kolbanev, I.V.; Karyagina, O.K.

    2014-01-01

    Graphical abstract: Temperature dependences of bulk conductivity for Sm{sub 2}ScTaO{sub 7} pyrochlore prepared at (1) 1400 °C, 20 h; and (2) 1200 °C, 40 h. - Highlights: • The phase formation of Ln{sub 2}RMO{sub 7} (Ln = Sm, Ho; R = Lu, Sc; M = Nb, Ta) at 1200–1600 °C. • The bulk conductivity and magnetic susceptibility were measured. • The bulk conductivity of Sm{sub 2}ScTaO{sub 7} has oxygen ion type at T ≥ 750 °C. • The first-order structural phase transition was observed in Sm{sub 2}ScTaO{sub 7} at ∼650–700 °C. • This phase transformation is not typical for defect fluorites. - Abstract: We have studied the new compounds with fluorite-like (Ho{sub 2}RNbO{sub 7} (R = Lu, Sc)) and pyrochlore-like (Sm{sub 2}ScTaO{sub 7}) structure as potential oxide ion conductors. The phase formation process (from 1200 to 1600 °C) and physical properties (electrical, thermo mechanical, and magnetic) for these compounds were investigated. Among the niobate materials the highest bulk conductivity is offered by the fluorite-like Ho{sub 2}ScNbO{sub 7} synthesized at 1600 °C: 3.8 × 10{sup −5} S/cm at 750 °C, whereas in Sm system the highest bulk conductivity, 7.3 × 10{sup −6} S/cm at 750 °C, is offered by the pyrochlore Sm{sub 2}ScTaO{sub 7} synthesized at 1400 °C. In Sm{sub 2}ScTaO{sub 7} pyrochlore we have observed the first-order phase transformation at ∼650–700 °C is related to rearrangement process in the oxygen sublattice of the pyrochlore structure containing B-site cations in different valence state and actually is absent in the defect fluorites. The two holmium niobates show Curie–Weiss paramagnetic behavior, with the prevalence of antiferromagnetic coupling. The magnetic susceptibility of Sm{sub 2}ScTaO{sub 7} is a weak function of temperature, corresponding to Van Vleck paramagnetism.

  13. Operational Challenges in Gas-To-Liquid (GTL) Transportation Through Trans Alaska Pipeline System (TAPS)

    SciTech Connect (OSTI)

    Godwin A. Chukwu; Santanu Khataniar; Shirish Patil; Abhijit Dandekar

    2006-06-30

    Oil production from Alaskan North Slope oil fields has steadily declined. In the near future, ANS crude oil production will decline to such a level (200,000 to 400,000 bbl/day) that maintaining economic operation of the Trans-Alaska Pipeline System (TAPS) will require pumping alternative products through the system. Heavy oil deposits in the West Sak and Ugnu formations are a potential resource, although transporting these products involves addressing important sedimentation issues. One possibility is the use of Gas-to-Liquid (GTL) technology. Estimated recoverable gas reserves of 38 trillion cubic feet (TCF) on the North Slope of Alaska can be converted to liquid with GTL technology and combined with the heavy oils for a product suitable for pipeline transport. Issues that could affect transport of this such products through TAPS include pumpability of GTL and crude oil blends, cold restart of the pipeline following a prolonged winter shutdown, and solids deposition inside the pipeline. This study examined several key fluid properties of GTL, crude oil and four selected blends under TAPS operating conditions. Key measurements included Reid Vapor Pressure, density and viscosity, PVT properties, and solids deposition. Results showed that gel strength is not a significant factor for the ratios of GTL-crude oil blend mixtures (1:1; 1:2; 1:3; 1:4) tested under TAPS cold re-start conditions at temperatures above - 20 F, although Bingham fluid flow characteristics exhibited by the blends at low temperatures indicate high pumping power requirements following prolonged shutdown. Solids deposition is a major concern for all studied blends. For the commingled flow profile studied, decreased throughput can result in increased and more rapid solid deposition along the pipe wall, resulting in more frequent pigging of the pipeline or, if left unchecked, pipeline corrosion.

  14. Spin Hall switching of the magnetization in Ta/TbFeCo structures with bulk perpendicular anisotropy

    SciTech Connect (OSTI)

    Zhao, Zhengyang; Jamali, Mahdi; Smith, Angeline K.; Wang, Jian-Ping

    2015-03-30

    Spin-orbit torques are studied in Ta/TbFeCo/MgO patterned structures, where the ferrimagnetic material TbFeCo provides a strong bulk perpendicular magnetic anisotropy (bulk-PMA) independent of the interfaces. The current-induced magnetization switching in TbFeCo is investigated in the presence of a perpendicular, longitudinal, or transverse field. An unexpected partial-switching phenomenon is observed in the presence of a transverse field unique to our bulk-PMA material. It is found that the anti-damping torque related with spin Hall effect is very strong, and a spin Hall angle is determined to be 0.12. The field-like torque related with Rashba effect is unobservable, suggesting that the interface play a significant role in Rashba-like torque.

  15. Resistance controllability and variability improvement in a TaO{sub x}-based resistive memory for multilevel storage application

    SciTech Connect (OSTI)

    Prakash, A. E-mail: amit.knp02@gmail.com Song, J.; Hwang, H. E-mail: amit.knp02@gmail.com; Deleruyelle, D.; Bocquet, M.

    2015-06-08

    In order to obtain reliable multilevel cell (MLC) characteristics, resistance controllability between the different resistance levels is required especially in resistive random access memory (RRAM), which is prone to resistance variability mainly due to its intrinsic random nature of defect generation and filament formation. In this study, we have thoroughly investigated the multilevel resistance variability in a TaO{sub x}-based nanoscale (<30 nm) RRAM operated in MLC mode. It is found that the resistance variability not only depends on the conductive filament size but also is a strong function of oxygen vacancy concentration in it. Based on the gained insights through experimental observations and simulation, it is suggested that forming thinner but denser conductive filament may greatly improve the temporal resistance variability even at low operation current despite the inherent stochastic nature of resistance switching process.

  16. Building America Case Study: Ground Source Heat Pump Research, TaC Studios Residence, Atlanta, Georigia (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2014-09-01

    As part of the NAHB Research Center Industry Partnership, Southface partnered with TaC Studios, an Atlanta based architecture firm specializing in residential and light commercial design, on the construction of a new test home in Atlanta, GA in the mixed-humid climate. This home serves as a residence and home office for the firm's owners, as well as a demonstration of their design approach to potential and current clients. Southface believes the home demonstrates current best practices for the mixed-humid climate, including a building envelope featuring advanced air sealing details and low density spray foam insulation, glazing that exceeds ENERGY STAR requirements, and a high performance heating and cooling system. Construction quality and execution was a high priority for TaC Studios and was ensured by a third party review process. Post construction testing showed that the project met stated goals for envelope performance, an air infiltration rate of 2.15 ACH50. The homeowner's wished to further validate whole house energy savings through the project's involvement with Building America and this long-term monitoring effort. As a Building America test home, this home was evaluated to detail whole house energy use, end use loads, and the efficiency and operation of the ground source heat pump and associated systems. Given that the home includes many non-typical end use loads including a home office, pool, landscape water feature, and other luxury features not accounted for in Building America modeling tools, these end uses were separately monitored to determine their impact on overall energy consumption.

  17. The susceptibility of TaOx-based memristors to high dose rate ionizing radiation and total ionizing dose

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    McLain, Michael Lee; Sheridan, Timothy J.; Hjalmarson, Harold Paul; Mickel, Patrick R.; Hanson, Donald J.; McDonald, Joseph K.; Hughart, David Russell; Marinella, Matthew J.

    2014-11-11

    This paper investigates the effects of high dose rate ionizing radiation and total ionizing dose (TID) on tantalum oxide (TaOx) memristors. Transient data were obtained during the pulsed exposures for dose rates ranging from approximately 5.0 ×107 rad(Si)/s to 4.7 ×108 rad(Si)/s and for pulse widths ranging from 50 ns to 50 μs. The cumulative dose in these tests did not appear to impact the observed dose rate response. Static dose rate upset tests were also performed at a dose rate of ~3.0 ×108 rad(Si)/s. This is the first dose rate study on any type of memristive memory technology. Inmore » addition to assessing the tolerance of TaOx memristors to high dose rate ionizing radiation, we also evaluated their susceptibility to TID. The data indicate that it is possible for the devices to switch from a high resistance off-state to a low resistance on-state in both dose rate and TID environments. The observed radiation-induced switching is dependent on the irradiation conditions and bias configuration. Furthermore, the dose rate or ionizing dose level at which a device switches resistance states varies from device to device; the enhanced susceptibility observed in some devices is still under investigation. As a result, numerical simulations are used to qualitatively capture the observed transient radiation response and provide insight into the physics of the induced current/voltages.« less

  18. Probing off-Hugoniot states in Ta, Cu, and Al to 1000 GPa compression with magnetically driven liner implosions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lemke, R. W.; Dolan, D. H.; Dalton, D. G.; Brown, J. L.; Tomlinson, K.; Robertson, G. R.; Knudson, M. D.; Harding, E.; Mattsson, A. E.; Carpenter, J. H.; et al

    2016-01-07

    We report on a new technique for obtaining off-Hugoniot pressure vs. density data for solid metals compressed to extreme pressure by a magnetically driven liner implosion on the Z-machine (Z) at Sandia National Laboratories. In our experiments, the liner comprises inner and outer metal tubes. The inner tube is composed of a sample material (e.g., Ta and Cu) whose compressed state is to be inferred. The outer tube is composed of Al and serves as the current carrying cathode. Another aluminum liner at much larger radius serves as the anode. A shaped current pulse quasi-isentropically compresses the sample as itmore » implodes. The iterative method used to infer pressure vs. density requires two velocity measurements. Photonic Doppler velocimetry probes measure the implosion velocity of the free (inner) surface of the sample material and the explosion velocity of the anode free (outer) surface. These two velocities are used in conjunction with magnetohydrodynamic simulation and mathematical optimization to obtain the current driving the liner implosion, and to infer pressure and density in the sample through maximum compression. This new equation of state calibration technique is illustrated using a simulated experiment with a Cu sample. Monte Carlo uncertainty quantification of synthetic data establishes convergence criteria for experiments. Results are presented from experiments with Al/Ta, Al/Cu, and Al liners. Symmetric liner implosion with quasi-isentropic compression to peak pressure ~1000 GPa is achieved in all cases. Lastly, these experiments exhibit unexpectedly softer behavior above 200 GPa, which we conjecture is related to differences in the actual and modeled properties of aluminum.« less

  19. Excited-state Raman spectroscopy with and without actinic excitation: S{sub 1} Raman spectra of trans-azobenzene

    SciTech Connect (OSTI)

    Dobryakov, A. L.; Quick, M.; Ioffe, I. N.; Granovsky, A. A.; Ernsting, N. P.; Kovalenko, S. A.

    2014-05-14

    We show that femtosecond stimulated Raman spectroscopy can record excited-state spectra in the absence of actinic excitation, if the Raman pump is in resonance with an electronic transition. The approach is illustrated by recording S{sub 1} and S{sub 0} spectra of trans-azobenzene in n-hexane. The S{sub 1} spectra were also measured conventionally, upon nπ* (S{sub 0} → S{sub 1}) actinic excitation. The results are discussed and compared to earlier reports.

  20. New high pressure rare earth tantalates RE{sub x}Ta{sub 2}O{sub 5+1.5x} (RE=La, Eu, Yb)

    SciTech Connect (OSTI)

    Zibrov, Igor P.; Filonenko, Vladimir P.; Zakharov, Nikolai D.; Nikishina, Elena E.; Lebedeva, Elena N.

    2013-07-15

    Rare earth tantalates La{sub 0.075}Ta{sub 2}O{sub 5.113}, Eu{sub 0.089}Ta{sub 2}O{sub 5.134} and Yb{sub 0.051}Ta{sub 2}O{sub 5.077} have been prepared by solid state reaction at P=7.0 GPa and T=1050–1100 °C and studied by X-ray diffraction, thermal analysis and electron microscopy. Low hydrated amorphous tantalum, lanthanum, europium and ytterbium hydroxides were used as starting materials. Aqueous as well as anhydrous compounds were obtained. Title tantalates are crystallized in the structure type of F–Ta{sub 2}O{sub 5} [Zibrov et al. Russ. J. Inorg. Chem. 48 (2003) 464–471] [5]. The structure was refined by the Rietveld method from X-ray powder diffractometer data: La{sub 0.075}Ta{sub 2}O{sub 5.113}, a=10.5099(2), b=7.2679(1), c=6.9765(1) Å, V=532.90(1) Å{sup 3}, Z=6, space group Ibam; Eu{sub 0.089}Ta{sub 2}O{sub 5.134}, a=10.4182(3), b=7.2685(1), c=6.9832(1) Å, V=528.80(2) Å{sup 3}, Z=6, space group Ibam; Yb{sub 0.051}Ta{sub 2}O{sub 5.077}, a=10.4557(2), b=7.3853(1), c=6.8923(1) Å, V=532.21(1) Å{sup 3}, Z=6, space group Ibam. RE atoms do not replace the tantalum in its positions but the only water in the channels of the structure. Highly charged cations RE{sup +3} compress the unit cell so that its volume becomes less than that of F–Ta{sub 2}O{sub 5}. Significant decrease of the unit cell volume after water removal from the structure is possible due to the puckering of pentagonal bipyramid layers and change of the corrugation angle in the layer. - Graphical abstract: The structure of RE{sub x}Ta{sub 2}O{sub 5+1.5x} and its HRTEM image (“A” arrows show empty channel, “B” arrows show filled channel). - Highlights: • We synthesized new tantalates of RE under high pressure high temperature conditions. • RE atoms replace water molecules in the channels of the structure. • Aqueous as well as anhydrous tantalates were obtained. • Highly charged cations RE{sup +3} compress the unit cell decreasing RE–O distances.

  1. Interfacing the Ab initio multiple spawning method with electronic structure methods in GAMESS: Photodecay of trans-Azomethane

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gaenko, Alexander; DeFusco, Albert; Varganov, Sergey A.; Martínez, Todd J.; Gordon, Mark S.

    2014-10-20

    This work presents a nonadiabatic molecular dynamics study of the nonradiative decay of photoexcited trans-azomethane, using the ab initio multiple spawning (AIMS) program that has been interfaced with the General Atomic and Molecular Electronic Structure System (GAMESS) quantum chemistry package for on-the-fly electronic structure evaluation. The interface strategy is discussed, and the capabilities of the combined programs are demonstrated with a nonadiabatic molecular dynamics study of the nonradiative decay of photoexcited trans-azomethane. Energies, gradients, and nonadiabatic coupling matrix elements were obtained with the state-averaged complete active space self-consistent field method, as implemented in GAMESS. The influence of initial vibrational excitationmore » on the outcome of the photoinduced isomerization is explored. Increased vibrational excitation in the CNNC torsional mode shortens the excited state lifetime. Depending on the degree of vibrational excitation, the excited state lifetime varies from ~60–200 fs. As a result, these short lifetimes are in agreement with time-resolved photoionization mass spectroscopy experiments.« less

  2. Tailoring the magnetic properties of new Fe-Ni-Co-Al-(Ta,Nb)-B superelastic rapidly quenched microwires

    SciTech Connect (OSTI)

    Borza, F. Lupu, N.; Dobrea, V.; Chiriac, H.

    2015-05-07

    Ferromagnetic Fe-Ni-Co-Al-(Ta,Nb)-B microwires with diameters from 170 μm to 50 μm, which possess both superelastic and good magnetic properties, have been prepared by rapid quenching from the melt using the in rotating water spinning technique followed by cold-drawing and ageing. The cold-drawing and annealing processes lead to the initialization of premartensitic phases as confirmed by the X-ray diffraction and scanning transmission electron microscopic investigations, more significantly in the 50 μm cold-drawn microwires. An increase in the coercive field and in the saturation magnetization has been obtained by annealing, more importantly in the case of Nb-containing alloy. Ageing by thermal or current annealing led to the initialization of the superelastic effect. High values of strain of up to 1.8%, very good repeatability under successive loading, and values of superelastic effect of up to 1.2% have been achieved. The structural analysis coupled with the stress-strain data suggests that these materials annealed at 800 °C have superelastic potential at reduced ageing times. The magnetic behavior was found to be easily tailored through both thermal and thermomagnetic treatments with changes in the magnetic parameters which can be contactless detected. The results are important for future applications where both mechanical and magnetic properties matter, i.e., sensing/actuating systems.

  3. Observation of magnon-mediated current drag in Pt/yttrium iron garnet/Pt(Ta) trilayers

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Li, Junxue; Xu, Yadong; Aldosary, Mohammed; Tang, Chi; Lin, Zhisheng; Zhang, Shufeng; Lake, Roger; Shi, Jing

    2016-03-02

    Pure spin current, a flow of spin angular momentum without flow of any accompanying net charge, is generated in two common ways. One makes use of the spin Hall effect in normal metals (NM) with strong spin–orbit coupling, such as Pt or Ta. The other utilizes the collective motion of magnetic moments or spin waves with the quasi-particle excitations called magnons. A popular material for the latter is yttrium iron garnet, a magnetic insulator (MI). Here we demonstrate in NM/MI/NM trilayers that these two types of spin currents are interconvertible across the interfaces, predicated as the magnon-mediated current drag phenomenon.more » The transmitted signal scales linearly with the driving current without a threshold and follows the power-law Tn with n ranging from 1.5 to 2.5. Lastly, our results indicate that the NM/MI/NM trilayer structure can serve as a scalable pure spin current valve device which is an essential ingredient in spintronics.« less

  4. Multiband Te p Based Superconductivity of Ta4Pd3Te16

    SciTech Connect (OSTI)

    Singh, David J.

    2014-10-06

    We recently discovered that Ta4Pd3Te16 is a superconductor that has been suggested to be an unconventional superconductor near magnetism. Here, we report electronic structure calculations showing that despite the layered crystal structure the material is an anisotropic three-dimensional (3D) metal. The Fermi surface contains prominent one-dimensional (1D) and two-dimensional (2D) features, including nested 1D sheets, a 2D cylindrical section, and a 3D sheet. Moreover, the electronic states that make up the Fermi surface are mostly derived from Te p states with small Ta d and Pd d contributions. This places the compound far from magnetic instabilities. The results are discussed in terms of multiband superconductivity.

  5. Draft Genome Sequence of thermoalkaliphilic Caldalkalibacillus thermarum strain TA2.A1 Reveals Molecular Adaptations to Extreme pH and Temperature

    SciTech Connect (OSTI)

    Kalamorz, Falk; Keis, Stefanie; Stanton, Jo-Ann; Brown, Steven D; Klingeman, Dawn Marie; Land, Miriam L; Han, Cliff; Martin, S L.; Morgan, Hugh; Cook, Greg

    2011-01-01

    The genes and molecular machines that allow for a thermoalkaliphilic lifestyle have not been defined. To address this goal, we report on the improved high-quality draft genome sequence of Caldalkalibacillus thermarum strain TA2.A1, an obligately aerobic bacterium that grows optimally at pH 9.5 and 65 to 70 C on a wide variety of carbon and energy sources.

  6. The Effect of Ramp Rate on the C49 to C54 Titanium Disilicide Phase Transformation from Ti and Ti(Ta)

    SciTech Connect (OSTI)

    BAILEY, GLENN A.; HU, YAO ZHI; SMITH, PAUL M.; TAY, SING PIN

    1999-09-22

    The C49 to C54 TiSi{sub 2} transformation temperature is shown to be reduced by increasing the ramp rate during rapid thermal processing and this effect is more pronounced for thinner initial Ti and Ti(Ta) films. Experiments were performed on blanket wafers and on wafers that had patterned polycrystalline Si lines with Si{sub 3}N{sub 4} sidewall spacers. Changing the ramp rate caused no change in the transformation temperature for 60 nm blanket Ti films. For blanket Ti films of 25 or 40 nm, however, increasing the ramp rate from 7 to 180 C/s decreased the transformation temperature by 15 C. Studies of patterned lines indicate that sheet resistance of narrow lines is reduced by increased ramp rates for both Ti and Ti(Ta) films, especially as the linewidths decrease below 0.4 {micro}m. This improvement is particularly pronounced for the thinnest Ti(Ta) films, which exhibited almost no linewidth effect after being annealed with a ramp rate of 75 C/s.

  7. Structural features and enhanced high-temperature oxygen ion transport in SrFe{sub 1-x}Ta{sub x}O{sub 3-{delta}}

    SciTech Connect (OSTI)

    Markov, Alexey A.; Shalaeva, Elizaveta V.; Tyutyunnik, Alexander P.; Kuchin, Vasily V.; Patrakeev, Mikhail V.; Leonidov, Ilya A.; Kozhevnikov, Victor L.

    2013-01-15

    Structural features, oxygen non-stoichiometry and transport properties are studied in the oxide series SrFe{sub 1-x}Ta{sub x}O{sub 3-{delta}}, where x=0.2, 0.3 and 0.4. X-ray diffraction and electron microscopy data evidence formation of the inhomogeneous materials at x=0.3 and 0.4, which include phase constituents with a cubic perovskite and a double perovskite structure types. The composition, the amount and the typical grain size of the phase inhomogeneities are shown to depend both on doping and oxygen content. The increased oxygen-ion conductivity is observed in oxygen depleted materials, which is explained by the increase in the amount of cubic perovskite-like phase and development of interfacial pathways favorable for enhanced oxygen ion transport. - Graphical abstract: The structural studies, oxygen content and conductivity measurements suggest that oxygen depletion from the double perovskite phase constituent of SrFe{sub 1-x}Ta{sub x}O{sub 3-{delta}} for x>0.2 is accompanied by formation of pathways for fast ion transport. Black-Small-Square Highlights: Black-Right-Pointing-Pointer The double perovskite type regions are shown to exist in SrFe{sub 1-x}Ta{sub x}O{sub 3-{delta}}. Black-Right-Pointing-Pointer The oxygen depletion is accompanied with phase separation. Black-Right-Pointing-Pointer The phase separation favors formation of pathways for enhanced oxygen ion transport.

  8. Thermodynamic and mechanical stabilities of α- and β-Ta{sub 4}AlC{sub 3} via first-principles investigations

    SciTech Connect (OSTI)

    Thawabi, Hassan S. Duong, Thien Arróyave, Raymundo

    2013-12-07

    Recently, it has been predicted that Ta{sub 4}AlC{sub 3} is likely to exhibit an (α–β) polymorphic transformation at temperatures above 1873 K. However, recent X-ray diffraction and transmission electron microscopy experiments suggest on the other hand that the α phase remains stable up to temperatures close to the limit of experimental capabilities and no transition has yet been observed. While the matter has already been settled experimentally, in this work, we re-investigate the phase stability problem in Ta{sub 4}AlC{sub 3} by using first-principles methods. The study was carried out by considering both thermodynamic and mechanical stabilities of the Ta{sub 4}AlC{sub 3} polymorphs. Particularly, finite-temperature Gibbs free energies and elastic properties of the polymorphs were calculated using density functional theory. Calculation results reveal that the α phase continue to be stable even at temperatures exceeding 1875 K, which is in agreement with experimental results reported in literature.

  9. Synthesis of 4-substituted-trans-1,2-diaminocyclohexyl polyaminocarboxylate metal chelating agents for the preparation of stable radiometal antibody immunoconjugates for therapy and spect and pet imaging

    DOE Patents [OSTI]

    Mease, Ronnie C.; Kolsky, Kathryn L.; Mausner, Leonard F.; Srivastava, Suresh C.

    1997-06-03

    Cyclohexyl chelating agents useful in forming antibody-metal conjugates useful for diagnostic and therapeutic purposes. New compounds and processes of forming these compounds are disclosed including 4-haloacetamido-trans-1,2-diaminocyclohexyl polyaminocarboxylate and 4-isothiocyanato-trans-1,2-diamino cyclohexane-N, N, N', N'-tetra acetic acid.

  10. Synthesis of 4-substituted-trans-1,2-diaminocyclohexyl polyaminocarboxylate metal chelating agents for the preparation of stable radiometal antibody immunoconjugates for therapy and SPECT and PET imaging

    DOE Patents [OSTI]

    Mease, R.C.; Kolsky, K.L.; Mausner, L.F.; Srivastava, S.C.

    1997-06-03

    Cyclohexyl chelating agents useful in forming antibody-metal conjugates which are used for diagnostic and therapeutic purposes are synthesized. New compounds and processes of forming these compounds are disclosed including 4-haloacetamido-trans-1,2-diaminocyclohexyl polyaminocarboxylate and 4-isothiocyanato-trans-1,2-diamino cyclohexane-N,N,N{prime},N{prime}-tetra acetic acid.

  11. Electron diffraction study of 1M illites with interstratified trans- and cis-vacant 2 : 1 layers

    SciTech Connect (OSTI)

    Zhukhlistov, A. P. Vikent'ev, I. V.; Rusinova, O. V.

    2012-03-15

    Illites from the volcanogenic Zn-Au-Ag sulfide deposit Galkinskoe (Northern Urals) have been investigated using oblique-texture electron diffraction patterns in combination with the simulation of diffraction effects. Along with single-phase tv/cv1M illites, the structures of which are formed by statistically interstratified dioctahedral 2: 1 layers with vacant trans- or cis-octahedra, illites in the form of a mixture of two interstratified tv/cv1M phases, with the dominance of tv- or cv layers, are identified. It is shown that in the latter case the diffraction pattern can also be interpreted within the single-phase tv/cv model, provided that the tv- and cv layers are distributed with some tendency to segregate. The structural features indicating the preference of the two-phase model are analyzed.

  12. West Texas geothermal resource assessment. Part II. Preliminary utilization assessment of the Trans-Pecos geothermal resource. Final report

    SciTech Connect (OSTI)

    Gilliland, M.W.; Fenner, L.B.

    1980-01-01

    The utilization potential of geothermal resources in Trans-Pecos, Texas was assessed. The potential for both direct use and electric power generation were examined. As with the resource assessment work, the focus was on the Hueco Tanks area in northeastern El Paso County and the Presidio Bolson area in Presidio County. Suitable users of the Hueco Tanks and Presidio Bolson resource areas were identified by matching postulated temperature characteristics of the geothermal resource to the need characteristics of existing users in each resource area. The amount of geothermal energy required and the amount of fossil fuel that geothermal energy would replace were calculated for each of the users identified as suitable. Current data indicate that temperatures in the Hueco Tanks resource area are not high enough for electric power generation, but in at least part of the Presidio Bolson resource area, they may be high enough for electric power generation.

  13. Synthesis, crystal structure, spectroscopic and thermal properties of [Et{sub 4}N][Ta{sub 6}Br{sub 12}(H{sub 2}O){sub 6}]Br{sub 4}.4H{sub 2}O (Et=ethyl)-A new compound with the paramagnetic [Ta{sub 6}Br{sub 12}]{sup 3+} cluster core

    SciTech Connect (OSTI)

    Peric, Berislav; Jozic, Drazan; Planinic, Pavica; Brnicevic, Nevenka; Giester, Gerald

    2009-09-15

    A new hexanuclear cluster compound, [Et{sub 4}N][Ta{sub 6}Br{sub 12}(H{sub 2}O){sub 6}]Br{sub 4}.4H{sub 2}O (Et=ethyl) (1), with the paramagnetic [Ta{sub 6}Br{sub 12}]{sup 3+} cluster entity, was synthesized and characterized by elemental and TG/DTA analyses, IR and UV/Vis spectroscopy and by a single-crystal X-ray diffraction study. The presence of the paramagnetic [Ta{sub 6}Br{sub 12}]{sup 3+} unit was confirmed also by the room-temperature magnetic and EPR measurements. The compound crystallizes in the tetragonal I4{sub 1}/a space group, with a=14.299(5), c=21.241(5) A, Z=4, R{sub 1}(F)/wR{sub 2}(F{sup 2})=0.0296/0.0811. The structure contains discrete [Ta{sub 6}Br{sub 12}(H{sub 2}O){sub 6}]{sup 3+} cations with an octahedron of metal atoms edge-bridged by bromine atoms and with water molecules occupying all six terminal positions. The cluster units are positioned in the vertices of the three-dimensional (pseudo)diamond lattice. The structure shows similarities with literature reported structures of cluster compounds crystallizing in the diamond (Fd3-barm) space group. - Graphical abstract: Two interpenetrating (pseudo)diamond nets formed by packing of the paramagnetic [Ta{sub 6}Br{sub 12}(H{sub 2}O)]{sup 3+} (octahedral) and diamagnetic [Et{sub 4}N]{sup +} (spheres) cations.

  14. Photocatalytic splitting of water under visible-light irradiation over the NiOx-loaded Sm{sub 2}InTaO{sub 7} with 4f-d{sup 10}-d{sup 0} configuration

    SciTech Connect (OSTI)

    Tang Xinde; Ye Hongqi; Liu Hui; Ma Chenxia; Zhao Zhi

    2010-01-15

    A new visible-light-response photocatalyst Sm{sub 2}InTaO{sub 7} with 4f-d{sup 10}-d{sup 0} configuration crystallized in a cubic system with the space group Fd3m was synthesized by a solid-state reaction method. NiOx-loaded Sm{sub 2}InTaO{sub 7} showed high photocatalytic activities for H{sub 2} evolution from pure water under visible light irradiation (lambda>400 nm). Changes in the photocatalytic activity with the calcination temperature of Sm{sub 2}InTaO{sub 7} and the amount of NiOx loaded indicated that the combination of highly crystallized Sm{sub 2}InTaO{sub 7} and a high dispersion of NiOx particles led to high photocatalytic activity. The high photocatalytic performance of NiOx-loaded Sm{sub 2}InTaO{sub 7} supported the existing view that the photocatalytic activity correlated with the lattice distortion. Density functional theory calculation indicated that strong dispersion from the hybridized In 5s 5p orbitals at the bottom of the conduction band was responsible for the high activity of photocatalyst Sm{sub 2}InTaO{sub 7}. - Graphical abstract: A new visible-light-response photocatalyst Sm{sub 2}InTaO{sub 7} with 4f-d{sup 10}-d{sup 0} configuration was developed. DFT calculation indicated that strong dispersion from the hybridized In 5s 5p orbitals was responsible for the high photocatalytic activity.

  15. NbF{sub 5} and TaF{sub 5}: Assignment of {sup 19}F NMR resonances and chemical bond analysis from GIPAW calculations

    SciTech Connect (OSTI)

    Biswal, Mamata; Body, Monique; Legein, Christophe; Sadoc, Aymeric; Boucher, Florent

    2013-11-15

    The {sup 19}F isotropic chemical shifts (?{sub iso}) of two isomorphic compounds, NbF{sub 5} and TaF{sub 5}, which involve six nonequivalent fluorine sites, have been experimentally determined from the reconstruction of 1D {sup 19}F MAS NMR spectra. In parallel, the corresponding {sup 19}F chemical shielding tensors have been calculated using the GIPAW method for both experimental and DFT-optimized structures. Furthermore, the [M{sub 4}F{sub 20}] units of NbF{sub 5} and TaF{sub 5} being held together by van der Waals interactions, the relevance of Grimme corrections to the DFT optimization processes has been evaluated. However, the semi-empirical dispersion correction term introduced by such a method does not show any significant improvement. Nonetheless, a complete and convincing assignment of the {sup 19}F NMR lines of NbF{sub 5} and TaF{sub 5} is obtained, ensured by the linearity between experimental {sup 19}F ?{sub iso} values and calculated {sup 19}F isotropic chemical shielding ?{sub iso} values. The effects of the geometry optimizations have been carefully analyzed, confirming among other matters, the inaccuracy of the experimental structure of NbF{sub 5}. The relationships between the fluorine chemical shifts, the nature of the fluorine atoms (bridging or terminal), the position of the terminal ones (opposite or perpendicular to the bridging ones), the fluorine charges, the ionicity and the length of the MF bonds have been established. Additionally, for three of the {sup 19}F NMR lines of NbF{sub 5}, distorted multiplets, arising from {sup 1}J-coupling and residual dipolar coupling between the {sup 19}F and {sup 93}Nb nuclei, were simulated yielding to values of {sup 93}Nb{sup 19}F {sup 1}J-coupling for the corresponding fluorine sites. - Graphical abstract: The complete assignment of the {sup 19}F NMR lines of NbF{sub 5} and TaF{sub 5} allow establishing relationships between the {sup 19}F ?{sub iso} values, the nature of the fluorine atoms (bridging or

  16. Vibrational quasi-degenerate perturbation theory with optimized coordinates: Applications to ethylene and trans-1,3-butadiene

    SciTech Connect (OSTI)

    Yagi, Kiyoshi Otaki, Hiroki

    2014-02-28

    A perturbative extension to optimized coordinate vibrational self-consistent field (oc-VSCF) is proposed based on the quasi-degenerate perturbation theory (QDPT). A scheme to construct the degenerate space (P space) is developed, which incorporates degenerate configurations and alleviates the divergence of perturbative expansion due to localized coordinates in oc-VSCF (e.g., local O–H stretching modes of water). An efficient configuration selection scheme is also implemented, which screens out the Hamiltonian matrix element between the P space configuration (p) and the complementary Q space configuration (q) based on a difference in their quantum numbers (λ{sub pq} = ∑{sub s}|p{sub s} − q{sub s}|). It is demonstrated that the second-order vibrational QDPT based on optimized coordinates (oc-VQDPT2) smoothly converges with respect to the order of the mode coupling, and outperforms the conventional one based on normal coordinates. Furthermore, an improved, fast algorithm is developed for optimizing the coordinates. First, the minimization of the VSCF energy is conducted in a restricted parameter space, in which only a portion of pairs of coordinates is selectively transformed. A rational index is devised for this purpose, which identifies the important coordinate pairs to mix from others that may remain unchanged based on the magnitude of harmonic coupling induced by the transformation. Second, a cubic force field (CFF) is employed in place of a quartic force field, which bypasses intensive procedures that arise due to the presence of the fourth-order force constants. It is found that oc-VSCF based on CFF together with the pair selection scheme yields the coordinates similar in character to the conventional ones such that the final vibrational energy is affected very little while gaining an order of magnitude acceleration. The proposed method is applied to ethylene and trans-1,3-butadiene. An accurate, multi-resolution potential, which combines the MP2 and

  17. Comparative study of structure formation and mechanical behavior of age-hardened Ti–Nb–Zr and Ti–Nb–Ta shape memory alloys

    SciTech Connect (OSTI)

    Inaekyan, K.; Brailovski, V.; Prokoshkin, S.; Pushin, V.; Dubinskiy, S.; Sheremetyev, V.

    2015-05-15

    This work sets out to study the peculiar effects of aging treatment on the structure and mechanical behavior of cold-rolled and annealed biomedical Ti–21.8Nb–6.0Zr (TNZ) and Ti–19.7Nb–5.8Ta (TNT) (at.%) shape memory alloys by means of transmission electron microscopy, X-ray diffractometry, functional fatigue and thermomechanical testing techniques. Dissimilar effects of aging treatment on the mechanical behavior of Zr- and Ta-doped alloys are explained by the differences in the ω-phase formation rate, precipitate size, fraction and distribution, and by their effect on the alloys' critical stresses and transformation temperatures. Even short-time aging of the TNZ alloy leads to its drastic embrittlement caused by “overaging”. On the contrary, during aging of the TNT alloy, formation of finely dispersed ω-phase precipitates is gradual and controllable, which makes it possible to finely adjust the TNT alloy functional properties using precipitation hardening mechanisms. To create in this alloy nanosubgrained dislocation substructure containing highly-dispersed coherent nanosized ω-phase precipitates, the following optimum thermomechanical treatment is recommended: cold rolling (true strain 0.37), followed by post-deformation annealing (600 °C, 15–30 min) and age-hardening (300 °C, 30 min) thermal treatments. It is shown that in TNT alloy, pre-transition diffraction effects (diffuse reflections) can “mask” the β-phase substructure and morphology of secondary phases. - Highlights: • TNZ alloy is characterized by much higher ω-phase precipitation rate than TNT alloy. • Difference in precipitation rates is linked to the difference in Zr and Ta diffusion mobility. • Aging of nanosubgrained TNZ alloy worsens its properties irrespective of the aging time. • Aging time of nanosubgrained TNT alloy can be optimized to improve its properties.

  18. Magnetic anisotropy in Ta/CoFeB/MgO investigated by x-ray magnetic circular dichroism and first-principles calculation

    SciTech Connect (OSTI)

    Kanai, Shun; Tsujikawa, Masahito; Shirai, Masafumi; Miura, Yoshio; Matsukura, Fumihiro Ohno, Hideo

    2014-12-01

    We study the spin and orbital magnetic moments in Ta/Co{sub 0.4}Fe{sub 0.4}B{sub 0.2}/MgO by x-ray magnetic circular dichroism measurements as well as first-principles calculations, in order to clarify the origin of the perpendicular magnetic anisotropy. Both experimental and theoretical results show that orbital magnetic moment of Fe is more anisotropic than that of Co with respect to the magnetization direction. The anisotropy is larger for thinner CoFeB, indicating that Fe atoms at the interface with MgO contribute more than Co to the observed perpendicular magnetic anisotropy.

  19. Collapse of ferromagnetism in itinerant-electron system: A magnetic, transport properties, and high pressure study of (Hf,Ta)Fe{sub 2} compounds

    SciTech Connect (OSTI)

    Diop, L. V. B. Isnard, O.; Kastil, J.; Arnold, Z.; Kamarad, J.

    2014-10-28

    The magnetism and transport properties were studied for Laves (Hf,Ta)Fe{sub 2} itinerant-electron compounds, which exhibit a temperature-induced first-order transition from the ferromagnetic (FM) to the antiferromagnetic (AFM) state upon heating. At finite temperatures, the field-induced metamagnetic phase transition between the AFM and FM has considerable effects on the transport properties of these model metamagnetic compounds. A large negative magnetoresistance of about 14% is observed in accordance with the metamagnetic transition. The magnetic phase diagram is determined for the Laves Hf{sub 1?x}Ta{sub x}Fe{sub 2} series and its Ta concentration dependence discussed. An unusual behavior is revealed in the paramagnetic state of intermediate compositions, it gives rise to the rapid increase and saturation of the local spin fluctuations of the 3d electrons. This new result is analysed in the frame of the theory of Moriya. For a chosen composition Hf{sub 0.825}Ta{sub 0.175}Fe{sub 2}, exhibiting such remarkable features, a detailed investigation is carried out under hydrostatic pressure up to 1?GPa in order to investigate the volume effect on the magnetic properties. With increasing pressure, the magnetic transition temperature T{sub FM-AFM} from ferromagnetic to antiferromagnetic order decreases strongly non-linearly and disappears at a critical pressure of 0.75?GPa. In the pressure-induced AFM state, the field-induced first-order AFM-FM transition appears and the complex temperature dependence of the AFM-FM transition field is explained by the contribution from both the magnetic and elastic energies caused by the significant temperature variation of the amplitude of the local Fe magnetic moment. The application of an external pressure leads also to the progressive decrease of the Nel temperature T{sub N}. In addition, a large pressure effect on the spontaneous magnetization M{sub S} for pressures below 0.45?GPa, dln(M{sub s})/dP?=??6.3??10{sup ?2?}GPa{sup ?1

  20. Preparation of W-Ta thin-film thermocouple on diamond anvil cell for in-situ temperature measurement under high pressure

    SciTech Connect (OSTI)

    Yang Jie; Li Ming; Zhang Honglin; Gao Chunxiao

    2011-04-15

    In this paper, a W-Ta thin-film thermocouple has been integrated on a diamond anvil cell by thin-film deposition and photolithography methods. The thermocouple was calibrated and its thermal electromotive force was studied under high pressure. The results indicate that the thermal electromotive force of the thermocouple exhibits a linear relationship with temperature and is not associated with pressure. The resistivity measurement of ZnS powders under high pressure at different temperatures shows that the phase transition pressure decreases as the temperature increases.

  1. g-C{sub 3}N{sub 4}/NaTaO{sub 3} organicinorganic hybrid nanocomposite: High-performance and recyclable visible light driven photocatalyst

    SciTech Connect (OSTI)

    Kumar, Santosh; Kumar, Bharat; Surendar, T.; Shanker, Vishnu

    2014-01-01

    Graphical abstract: High-performance and recyclable visible-light driven g-C{sub 3}N{sub 4}/NaTaO{sub 3} hybrid nanocomposite photocatalysts have been prepared by a facile ultrasonic dispersion method. The hybrid nanocomposite photocatalyst can be promising photocatalytic material for practical application in water splitting and environmental remediation. - Highlights: Novel g-C{sub 3}N{sub 4}/NaTaO{sub 3} nanocomposites as a high performance and recyclable photocatalysts. These catalysts exhibited significantly enhanced photocatalytic activity under UVvisible light irradiation. More attractively, dramatic activity is generated under visible light irradiation due to the g-C{sub 3}N{sub 4} loaded. Interestingly, the as-prepared hybrid nanocomposites possess high reusability. - Abstract: Novel g-C{sub 3}N{sub 4}/NaTaO{sub 3} hybrid nanocomposites have been prepared by a facile ultrasonic dispersion method. Our results clearly show the formation of interface between NaTaO{sub 3} and g-C{sub 3}N{sub 4} and further loading of g-C{sub 3}N{sub 4} did not affect the crystal structure and morphology of NaTaO{sub 3}. The g-C{sub 3}N{sub 4}/NaTaO{sub 3} nanocomposites exhibited enhanced photocatalytic performance for the degradation of Rhodamine B under UVvisible and visible light irradiation compared to pure NaTaO{sub 3} and Degussa P25. Interestingly, the visible light photocatalytic activity is generated due to the loading of g-C{sub 3}N{sub 4}. A mechanism is proposed to discuss the enhanced photocatalytic activity based on trapping experiments of photoinduced radicals and holes. Under visible light irradiation, electron excited from the valance band (VB) to conduction band (CB) of g-C{sub 3}N{sub 4} could directly inject into the CB of NaTaO{sub 3}, making g-C{sub 3}N{sub 4}/NaTaO{sub 3} visible light driven photocatalyst. Since the as-prepared hybrid nanocomposites possess high reusability therefore it can be promising photocatalyst for environmental

  2. Human dose assessment for the radionuclides {sup 90}Sr and {sup 90}Y at TA-35 SWMU 35-003 (r) and Ten Site Canyon

    SciTech Connect (OSTI)

    Jarmer, D.; Lyman, J.

    1997-07-01

    This report gives an estimate of the radiological dose to an individual living on or working at a site contaminated with strontium-90 ({sup 90}Sr) and yttrium-90 ({sup 90}Y). The site consists of a small receiving canyon that drains into Ten-Site Canyon at the eastern end of Los Alamos National Laboratory`s technical area 35 (TA-35). Between 1951 and 1963 a wastewater treatment facility located at TA-35 discharged water containing {sup 90}Sr and {sup 90}Y to this receiving canyon. The authors used the RESRAD computer code to calculate the dose to an on-site individual, based on two exposure scenarios: (1) a person working at the site for eight hours a day, five days a week, for twenty-five years and (2) a farmer living at the site twenty four hours a day, seven days a week, for thirty years. The exposure pathways considered were direct exposure to external radiation; inhalation of contaminated dusts; and ingestion of plants, water, and soil. The authors found that the maximum estimated dose rates were 1 and 21 mrem y{sup {minus}1} for the worker and farmer scenarios respectively. The authors have concluded that the value for the worker scenario is well below the DOE dose limit of 100 mrem y{sup {minus}1} but the farmer is overexposed.

  3. HUMAN MACHINE INTERFACE (HMI) EVALUATION OF ROOMS TA-50-1-60/60A AT THE RADIOACTIVE LIQUID WASTE TREATMENT FACILITY (RLWTF)

    SciTech Connect (OSTI)

    Gilmore, Walter E.; Stender, Kerith K.

    2012-08-29

    This effort addressed an evaluation of human machine interfaces (HMIs) in Room TA-50-1-60/60A of the Radioactive Liquid Waste Treatment Facility (RLWTF). The evaluation was performed in accordance with guidance outlined in DOE-STD-3009, DOE Standard Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Documented Safety Analyses, 2006 [DOE 2006]. Specifically, Chapter 13 of DOE 2006 highlights the 10 CFR 830, Nuclear Safety Management, 2012, [CFR 2012] and DOE G 421.1-2 [DOE 2001a] requirements as they relate to the human factors process and, in this case, the safety of the RLWTF. The RLWTF is a Hazard Category 3 facility and, consequently, does not have safety-class (SSCs). However, safety-significant SSCs are identified. The transuranic (TRU) wastewater tanks and associated piping are the only safety-significant SSCs in Rooms TA-50-1-60/60A [LANL 2010]. Hence, the human factors evaluation described herein is only applicable to this particular assemblage of tanks and piping.

  4. An aqueous route to [Ta6O19]8- and solid-state studies of isostructural niobium and tantalum oxide complexes.

    SciTech Connect (OSTI)

    Nyman, May D.; Anderson, Travis Mark; Alam, Todd M.; Rodriguez, Mark Andrew; Joel N. Bixler; Francois Bonhomme

    2007-10-01

    Tantalate materials play a vital role in our high technology society: tantalum capacitors are found in virtually every cell phone. Furthermore, electronic characteristics and the incredibly inert nature of tantalates renders them ideal for applications such as biomedical implants, nuclear waste forms, ferroelectrics, piezoelectrics, photocatalysts and optical coatings. The inert and insoluble nature of tantalates is not fundamentally understood; and furthermore poor solubility renders fabrication of novel or optimized tantalates very difficult. We have developed a soft chemical route to water-soluble tantalum oxide clusters that can serve as both precursors for novel tantalate materials and ideal models for experimental and computational approaches to understanding the unusually inert behavior of tantalates. The water soluble cluster, [Ta6O19]8- is small, highly symmetric, and contains the representative oxygen types of a metal oxide surface, and thus ideally mimics a complex tantalate surface in a simplistic form that can be studied unambiguously. Furthermore; in aqueous solution, these highly charged and super-basic clusters orchestrate surprising acid-base behavior that most likely plays an important role in the inertness of related oxide surfaces. Our unique synthetic approach to the [Ta6O19]8- cluster allowed for unprecedented enrichment with isotopic labels (17O), enabling detailed kinetic and mechanistic studies of the behavior of cluster oxygens, as well as their acid-base behavior. This SAND report is a collection of two publications that resulted from these efforts.

  5. A density-functional study on the stability of anatase-type phases in the system Mg-Ta-O-N

    SciTech Connect (OSTI)

    Wolff, Holger; Lerch, Martin; Schilling, Heikko; Baehtz, Carsten; Dronskowski, Richard

    2008-10-15

    Magnesium-doped tantalum oxynitrides, which were prepared by ammonolysis of amorphous mixed oxides, have been investigated using quantum-theoretical methods. For small magnesium amounts (5 cat%), density-functional total-energy calculations indicate an anatase-type structure consisting of stretched, corner-sharing TaO{sub 3}N{sub 3} octahedra with a tetrahedrally distorted equatorial plane. The calculated structural parameters are in excellent agreement with those obtained using X-ray powder diffraction and synchrotron radiation. Additionally, the quantum-chemical results show a clear preference for an ordered anionic distribution (space group I4{sub 1}md, no. 109) of the host lattice, which is locally disturbed around Mg{sup 2+}. For thermodynamical reasons, the excess oxygen anions, which replace nitrogen on account of the lower charge of the dopant cation, segregate next to magnesium, thus forming local MgO 'domains'. For higher magnesium contents ({>=}10%), minor phases of rutile-type structure have to be expected, which is in good agreement with experimental data. - Density-functional total energy of Mg-doped TaON in several polymorphs, each in its most stable arrangement, as a function of the dopant amount.

  6. Phase transition in the Ruddlesden-Popper layered perovskite Li{sub 2}SrTa{sub 2}O{sub 7}

    SciTech Connect (OSTI)

    Pagnier, T.; Rosman, N.; Galven, C.; Suard, E.; Fourquet, J.L.; Le Berre, F.; Crosnier-Lopez, M.P.

    2009-02-15

    The crystal structure of the Ruddlesden-Popper layered perovskite Li{sub 2}SrTa{sub 2}O{sub 7} has been characterized at various temperatures between -185 and 300 deg. C by several techniques: X-ray and neutron powder diffraction, single crystal diffraction, transmission electron microscopy and Raman spectroscopy. The low temperature structure has been confirmed to be orthorhombic Cmcm with a small octahedra antiphase tilting ({phi}{phi}0) ({phi}{phi}0) inside the perovskite blocks. With temperature, the tilting progressively vanishes leading around 230 deg. C to a tetragonal symmetry (S.G. I4/mmm). This reversible phase transition, followed by X-ray and neutron thermodiffraction and thermal Raman measurements, is considered as of second order. An attribution of the Raman bands based on normal mode analysis is proposed. - Graphical abstract: Thermal evolution of Li{sub 2}SrTa{sub 2}O{sub 7} X-ray powder diffraction patterns showing the structural transformation from orthorhombic to tetragonal cell.

  7. In situ X-ray diffraction strain-controlled study of TiNbZr and TiNbTa shape memory alloys: crystal lattice and transformation features

    SciTech Connect (OSTI)

    Dubinskiy, S.; Prokoshkin, S.; Brailovski, V.; Inaekyan, K.; Korotitskiy, A.

    2014-02-15

    Phase and structure transformations in biomedical Ti21.8Nb6.0Zr (TNZ) and Ti19.7Nb5.8Ta (TNT) shape memory alloys (at.%) under and without load in the ? 150 to 100 S temperature range are studied in situ using an original tensile module for a low-temperature chamber of an X-ray diffractometer. Alpha?- and beta-phase lattice parameters, the crystallographic resource of recovery strain, phase and structure transformation sequences, and microstress appearance and disappearance are examined, compared and discussed. For both alloys, the crystallographic resource of recovery strain decreases with temperature increase to become 4.5% for TNZ and 2.5% for TNT alloy (at RT). Loading at low temperatures leads to additional ??-phase formation and reorientation. Heating under load, as compared to strain-free heating, affects the reverse transformation sequence of both alloys in different ways. For TNZ alloy, strain-free heating results in simultaneous ??? and ???? transformations, whereas during heating under stress, they are sequential: ? + ???? precedes ????. For TNT alloy, strain-free heating results in reverse ???? transformation, whereas during heating under stress, ???? transformation is preceded by ??-phase reorientation. - Highlights: Comparative in situ XRD analysis of TiNbZr(Ta) shape memory alloys is realized. Lattice parameters of ?- and ??-phases are calculated in the ? 150 to + 100 C range. The higher the temperature, the lower the ???? transformation strain. Loading at low temperatures results in ??-phase formation and reorientation. Transformation sequences upon heating with and without loading are different.

  8. Joint contributions of Ag ions and oxygen vacancies to conducting filament evolution of Ag/TaO{sub x}/Pt memory device

    SciTech Connect (OSTI)

    Chung, Yu-Lung; Cheng, Wen-Hui; Chen, Wei-Chih; Jhan, Sheng-An; Chen, Jen-Sue; Jeng, Jiann-Shing

    2014-10-28

    The electroforming and resistive switching behaviors in the Ag/TaO{sub x}/Pt trilayer structure are investigated under a continual change of temperatures between 300?K and 100?K to distinguish the contributions of Ag ions and oxygen vacancies in developing of conducting filaments. For either electroforming or resistive switching, a significantly higher forming/set voltages is needed as the device is operated at 100?K, as compared to that observed when operating at 300?K. The disparity in forming/set voltages of Ag/TaO{sub x}/Pt operating at 300?K and 100?K is attributed to the contribution of oxygen vacancies, in addition to Ag atoms, in formation of conducting filament at 100?K since the mobilities of oxygen vacancies and Ag ions become comparable at low temperature. The presence of oxygen vacancy segment in the conducting filament also modifies the reset current from a gradually descending behavior (at 300?K) to a sharp drop (at 100?K). Furthermore, the characteristic set voltage and reset current are irreversible as the operation temperature is brought from 100?K back to 300?K, indicating the critical role of filament constituents on the switching behaviors of Ag/oxide/Pt system.

  9. Stereochemical effects in the gas-phase pinacol rearrangement. 2. Ring contraction versus methyl migration in cis- and trans-1,2-dimethylcyclohexane-1,2-diol

    SciTech Connect (OSTI)

    de Petris, G.; Giacomello, P.; Pizzabiocca, A.; Renzi, G.; Speranza, M.

    1988-02-17

    The gas-phase pinacol rearrangement of cis- and trans-1,2-dimethylcyclohexane-1,2-diols, promoted by D/sub 3//sup +/, CH/sub 5//sup +//C/sub 2/H/sub 5//sup +/ and t-C/sub 4/H/sub 9//sup +/ ions, was studied by mass spectrometric and radiolytic methods in the pressure range 0.5-760 Torr. When product isomerization is inhibited, by using N(CH/sub 3/)/sub 3/ as a trapping reagent at high pressure, mixtures of 2,2-dimethylcyclohexanone and 1-acetyl-1-methylcyclopentane were recovered from the reaction. In methane, the trend of the measured relative rates for ring contraction (k/sub 5/), methyl or hydroxyl group migration (k/sub 6/) versus the rearrangement rate of pincaol itself (k/sub p/), is k/sub 6/(trans) approx. k/sub 5/(trans) greater than or equal to k/sub 5/(cis) > k/sub 6/(cis) greater than or equal to k/sub p/. No evidence for the formation of an intermediate carbenium ion was found. Stereochemical aspects of the mechanism are discussed and compared with solution data.

  10. Effect of the valence electron concentration on the bulk modulus and chemical bonding in Ta{sub 2}AC and Zr{sub 2}AC (A=Al, Si, and P)

    SciTech Connect (OSTI)

    Schneider, Jochen M.; Music, Denis; Sun Zhimei

    2005-03-15

    We have studied the effect of the valence electron concentration, on the bulk modulus and the chemical bonding in Ta{sub 2}AC and Zr{sub 2}AC (A=Al, Si, and P) by means of ab initio calculations. Our equilibrium volume and the hexagonal ratio (c/a) agree well (within 2.7% and 1.2%, respectively) with previously published experimental data for Ta{sub 2}AlC. The bulk moduli of both Ta{sub 2}AC and Zr{sub 2}AC increase as Al is substituted with Si and P by 13.1% and 20.1%, respectively. This can be understood since the substitution is associated with an increased valence electron concentration, resulting in band filling and an extensive increase in cohesion.

  11. THE PECULIAR PHOTOMETRIC PROPERTIES OF 2010 WG9: A SLOWLY ROTATING TRANS-NEPTUNIAN OBJECT FROM THE OORT CLOUD

    SciTech Connect (OSTI)

    Rabinowitz, David; Schwamb, Megan E.; Hadjiyska, Elena; Tourtellotte, Suzanne; Rojo, Patricio

    2013-07-01

    We present long-term BVRI observations of 2010 WG9, an {approx}100 km diameter trans-Neptunian object (TNO) with an extremely high inclination of 70 Degree-Sign discovered by the La Silla-QUEST southern sky survey. Most of the observations were obtained with ANDICAM on the SMARTS 1.3 m at Cerro Tololo, Chile from 2010 December to 2012 November. Additional observations were made with EFOSC2 on the 3.5 m NTT telescope of the European Southern Observatory at La Silla, Chile in 2011 February. The observations reveal a sinusoidal light curve with amplitude 0.14 mag and period 5.4955 {+-} 0.0025 days, which is likely half the true rotation period. Such long rotation periods have previously been observed only for tidally evolved binary TNOs, suggesting that 2010 WG9 may be such a system. We predict a nominal separation of at least 790 km, resolvable with the Hubble Space Telescope and ground-based systems. We measure B - R = 1.318 {+-} 0.029 and V - R = 0.520 {+-} 0.018, consistent with the colors of modestly red Centaurs and Damocloids. At I-band wavelengths, we observe an unusually large variation of color with rotational phase, with R - I ranging from 0.394 {+-} 0.025 to 0.571 {+-} 0.044. We also measure an absolute R-band absolute magnitude of 7.93 {+-} 0.05 and solar phase coefficient of 0.049 {+-} 0.019 mag deg{sup -1}.

  12. Application of the Hartmann–Tran profile to precise experimental data sets of 12C2H2

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Forthomme, D.; Cich, M. J.; Twagirayezu, S.; Hall, G. E.; Sears, T. J.

    2015-06-25

    Self- and nitrogen-broadened line shape data for the Pe(11) line of the ν₁ + ν₃ band of acetylene, recorded using a frequency comb-stabilized laser spectrometer, have been analyzed using the Hartmann–Tran profile (HTP) line shape model in a multispectrum fitting. In total, the data included measurements recorded at temperatures between 125 K and 296 K and at pressures between 4 and 760 Torr. New, sub-Doppler, frequency comb-referenced measurements of the positions of multiple underlying hot band lines have also been made. These underlying lines significantly affect the Pe(11) line profile at temperatures above 240 K and poorly known frequencies previouslymore » introduced errors into the line shape analyses. Thus, the behavior of the HTP model was compared to the quadratic speed dependent Voigt profile (QSDVP) expressed in the frequency and time domains. A parameter uncertainty analysis was carried out using a Monte Carlo method based on the estimated pressure, transmittance and frequency measurement errors. From the analyses, the Pe(11) line strength was estimated to be 1.2014(50) × 10-20 in cm.molecules⁻¹ units at 296 K with the standard deviation in parenthesis. For analyzing these data, we found that a reduced form of the HTP, equivalent to the QSDVP, was most appropriate because the additional parameters included in the full HTP were not well determined. As a supplement to this work, expressions for analytic derivatives and a lineshape fitting code written in Matlab for the HTP are available.« less

  13. Development of a simultaneous Hugoniot and temperature measurement for preheated-metal shock experiments: Melting temperatures of Ta at pressures of 100 GPa

    SciTech Connect (OSTI)

    Li Jun; Zhou Xianming; Li Jiabo; Wu Qiang; Cai Lingcang; Dai Chengda

    2012-05-15

    Equations of state of metals are important issues in earth science and planetary science. A major limitation of them is the lack of experimental data for determining pressure-volume and temperature of shocked metal simultaneously. By measuring them in a single experiment, a major source of systematic error is eliminated in determining from which shock pressure release pressure originates. Hence, a non-contact fast optical method was developed and demonstrated to simultaneously measure a Hugoniot pressure-volume (P{sub H}-V{sub H}) point and interfacial temperature T{sub R} on the release of Hugoniot pressure (P{sub R}) for preheated metals up to 1000 K. Experimental details in our investigation are (i) a Ni-Cr resistance coil field placed around the metal specimen to generate a controllable and stable heating source, (ii) a fiber-optic probe with an optical lens coupling system and optical pyrometer with ns time resolution to carry out non-contact fast optical measurements for determining P{sub H}-V{sub H} and T{sub R}. The shock response of preheated tantalum (Ta) at 773 K was investigated in our work. Measured data for shock velocity versus particle velocity at an initial state of room temperature was in agreement with previous shock compression results, while the measured shock data between 248 and 307 GPa initially heated to 773 K were below the Hugoniot evaluation from its off-Hugoniot states. Obtained interfacial temperatures on release of Hugoniot pressures (100-170 GPa) were in agreement with shock-melting points at initial ambient condition and ab initio calculations of melting curve. It indicates a good consistency for shock melting data of Ta at different initial temperatures. Our combined diagnostics for Hugoniot and temperature provides an important approach for studying EOS and the temperature effect of shocked metals. In particular, our measured melting temperatures of Ta address the current controversy about the difference by more than a factor of 2

  14. Multiple copies of orbital angular momentum states through second-harmonic generation in a two-dimensional periodically poled LiTaO{sub 3} crystal

    SciTech Connect (OSTI)

    Fang, Xinyuan; Wei, Dunzhao; Liu, Dongmei; Zhong, Weihao; Ni, Rui; Chen, Zhenhua; Hu, Xiaopeng; Zhang, Yong Zhu, S. N.; Xiao, Min

    2015-10-19

    We experimentally demonstrate multiple copies of optical orbital angular momentum (OAM) states through quasi-phase-matched (QPM) second-harmonic (SH) generation in a 2D periodically poled LiTaO{sub 3} (PPLT) crystal. Since the QPM condition is satisfied by involving different reciprocal vectors in the 2D PPLT crystal, collinear and noncollinear SH beams carrying OAMs of l{sub 2} are simultaneously generated by the input fundamental beam with an OAM of l{sub 1}. The OAM conservation law (i.e., l{sub 2} = 2l{sub 1}) holds well in the experiment, which can tolerate certain phase-mismatch between the interacting waves. Our results provide an efficient way to obtain multiple copies of the wavelength-converted OAM states, which can be used to enhance the capacity in optical communications.

  15. Integrated quasi-phase-matched second-harmonic generator and electrooptic scanner on LiTaO{sub 3} single crystals

    SciTech Connect (OSTI)

    Gopalan, V.; Kawas, M.J.; Schlesinger, T.E.; Stancil, D.D.; Gupta, M.C.

    1996-12-01

    The authors report the first integrated quasi-phase-matched second-harmonic generator and electrooptic scanner on ferroelectric Z-cut LiTaO{sub 3}. The quasi-phase-matched second-harmonic generation device frequency doubles the infrared light at 829.7 nm into blue at 414.85 nm with a bulk conversion efficiency of 0.52%/W-cm. The blue light generated in the bulk then passes through an electrooptic scanner, consisting of a series of lithographically defined triangular-shaped domain-inverted regions extending through the thickness of the crystal. A deflection of 12 mrad/kv for the output blue light and 7.4 mrad/kv for the infrared light was observed at the scanner output.

  16. Lattice-level observation of the elastic-to-plastic relaxation process with subnanosecond resolution in shock-compressed Ta using time-resolved in situ Laue diffraction

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wehrenberg, C. E.; Comley, A. J.; Barton, N. R.; Coppari, F.; Fratanduono, D.; Huntington, C. M.; Maddox, B. R.; Park, H. -S.; Plechaty, C.; Prisbrey, S. T.; et al

    2015-09-29

    We report direct lattice level measurements of plastic relaxation kinetics through time-resolved, in-situ Laue diffraction of shock-compressed single-crystal [001] Ta at pressures of 27-210 GPa. For a 50 GPa shock, a range of shear strains is observed extending up to the uniaxial limit for early data points (<0.6 ns) and the average shear strain relaxes to a near steady state over ~1 ns. For 80 and 125 GPa shocks, the measured shear strains are fully relaxed already at 200 ps, consistent with rapid relaxation associated with the predicted threshold for homogeneous nucleation of dislocations occurring at shock pressure ~65 GPa.more » The relaxation rate and shear stresses are used to estimate the dislocation density and these quantities are compared to the Livermore Multiscale Strength model as well as various molecular dynamics simulations.« less

  17. Phanerozoic tectono-stratigraphic evolution of the Trans-Pecos and Permian basin regions (Mexico, Texas, New Mexico) using Landsat imagery, subsurface and outcrop data

    SciTech Connect (OSTI)

    Markello, J.R.; Sarg, J.F.

    1996-08-01

    Integrating regional Landsat imagery, outcrop field studies, and subsurface data has resulted in a more comprehensive understanding and delineation of the tectono-stratigraphic evolution of the Trans-Pecos region. Landsat imagery were acquired and registered to the existing 1:25000 scale maps and mosaiced to create a regional view of the Trans-Pecos and Permian basin region. The imagery were used to extrapolate and map key stratigraphic and tectonic elements after calibration from documented outcrop and subsurface data. The interpretations aided in the extrapolation of scattered control information and were critical in the complete reconstruction of the geologic history of the area. The Trans-Pecos Phanerozoic history comprises five tectono-depositional phases, and these have controlled the shape of the modem landscape: (1) Late Proterozoic rifting (Gondwana from Laurentia), and development of the Early-Middle Paleozoic Tobosa basin; (2) Pennsylvanian collision (South and North Americas), and differentiation of the Tobosa basin into the Midland, Delaware, Orogrande, and Pedregosa basins separated by basement blocks: Central Basin Platform, Diablo Platform, Burro-Florida Platform; (3) Middle Mesozoic transtensional rifting (Mexico from North America), and Late Jurassic failed rifting of the Mexican Chihuahua and Coahuila Troughs west and south of the Diablo Platform; (4) Late Mesozoic Laramide collision (Mexico and Texas), and development of the Chihuahua fold/thrust belt limited by the western margin of the Diablo Platform; (5) Late Cenozoic North American basin and Range rifting, and development of Rio Grande grabens, block-faulted mountains, and volcanics. The Tobosa basin was a passive-margin interior sag; its continental margin was south of the Marathons.

  18. Structure of a putative trans-editing enzyme for prolyl-tRNA synthetase from Aeropyrum pernix K1 at 1.7 Å resolution

    SciTech Connect (OSTI)

    Murayama, Kazutaka; Kato-Murayama, Miyuki; Katsura, Kazushige; Uchikubo-Kamo, Tomomi; Yamaguchi-Hirafuji, Machiko; Kawazoe, Masahito; Akasaka, Ryogo; Hanawa-Suetsugu, Kyoko; Hori-Takemoto, Chie; Terada, Takaho; Shirouzu, Mikako; Yokoyama, Shigeyuki

    2005-01-01

    The three-dimensional structure of the APE2540 protein from A. pernix K1 has been determined by the multiple anomalous dispersion method at 1.7 Å resolution. The structure includes two monomers in the asymmetric unit and shares structural similarity with the YbaK protein or cysteinyl-tRNA{sup Pro} deacylase from H. influenzae. The crystal structure of APE2540, the putative trans-editing enzyme ProX from Aeropyrum pernix K1, was determined in a high-throughput manner. The crystal belongs to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 47.4, b = 58.9, c = 53.6 Å, β = 106.8°. The structure was solved by the multiwavelength anomalous dispersion method at 1.7 Å and refined to an R factor of 16.8% (R{sub free} = 20.5%). The crystal structure includes two protein molecules in the asymmetric unit. Each monomer consists of eight β-strands and seven α-helices. A structure-homology search revealed similarity between the trans-editing enzyme YbaK (or cysteinyl-tRNA{sup Pro} deacylase) from Haemophilus influenzae (HI1434; 22% sequence identity) and putative ProX proteins from Caulobacter crescentus (16%) and Agrobacterium tumefaciens (21%)

  19. Interfacing the Ab initio multiple spawning method with electronic structure methods in GAMESS: Photodecay of trans-Azomethane

    SciTech Connect (OSTI)

    Gaenko, Alexander; DeFusco, Albert; Varganov, Sergey A.; Martnez, Todd J.; Gordon, Mark S.

    2014-10-20

    This work presents a nonadiabatic molecular dynamics study of the nonradiative decay of photoexcited trans-azomethane, using the ab initio multiple spawning (AIMS) program that has been interfaced with the General Atomic and Molecular Electronic Structure System (GAMESS) quantum chemistry package for on-the-fly electronic structure evaluation. The interface strategy is discussed, and the capabilities of the combined programs are demonstrated with a nonadiabatic molecular dynamics study of the nonradiative decay of photoexcited trans-azomethane. Energies, gradients, and nonadiabatic coupling matrix elements were obtained with the state-averaged complete active space self-consistent field method, as implemented in GAMESS. The influence of initial vibrational excitation on the outcome of the photoinduced isomerization is explored. Increased vibrational excitation in the CNNC torsional mode shortens the excited state lifetime. Depending on the degree of vibrational excitation, the excited state lifetime varies from ~60200 fs. As a result, these short lifetimes are in agreement with time-resolved photoionization mass spectroscopy experiments.

  20. Manipulation of electronic and magnetic properties of M{sub 2}C (M = Hf, Nb, Sc, Ta, Ti, V, Zr) monolayer by applying mechanical strains

    SciTech Connect (OSTI)

    Zhao, Shijun; Kang, Wei; Xue, Jianming

    2014-03-31

    Tuning the electronic and magnetic properties of a material through strain engineering is an effective strategy to enhance the performance of electronic and spintronic devices. In this paper, first-principles calculations based on density functional theory are carried out to investigate the electronic and magnetic properties of M{sub 2}C(M = Hf, Nb, Sc, Ta, Ti, V, Zr, known as MXenes) subjected to biaxial symmetric mechanical strains. At the strain-free state, all these MXenes exhibit no spontaneous magnetism except for Ti{sub 2}C and Zr{sub 2}C which show a magnetic moment of 1.92 and 1.25 μ{sub B}/unit, respectively. As the tensile strain increases, the magnetic moments of MXenes are greatly enhanced and a transition from nonmagnetism to ferromagnetism is observed for those nonmagnetic MXenes at zero strains. The most distinct transition is found in Hf{sub 2}C, in which the magnetic moment is elevated to 1.5 μ{sub B}/unit at a strain of 1.80%. We further show that the magnetic properties of Hf{sub 2}C are attributed to the band shift mainly composed of Hf(5d) states.

  1. Multiphoton photoluminescence contrast in switched Mg:LiNbO{sub 3} and Mg:LiTaO{sub 3} single crystals

    SciTech Connect (OSTI)

    Reichenbach, P., E-mail: philipp.reichenbach@iapp.de; Kmpfe, T.; Thiessen, A.; Haumann, A.; Eng, L. M. [Institut fr Angewandte Photophysik, Technische Universitt Dresden, George-Bhr-Str. 1, 01069 Dresden (Germany); Woike, T. [Institut fr Strukturphysik, Technische Universitt Dresden, Zellescher Weg 16, 01069 Dresden (Germany)

    2014-09-22

    We observed a multiphoton luminescence contrast between virgin and single-switched domains in Mg-doped LiNbO{sub 3} (LNO) and LiTaO{sub 3} (LTO) single crystals with different doping levels of 07?mol. % and 08?mol. %, respectively. A luminescence contrast in the range of 3% was measured between as-grown and electrically inverted domain areas in Mg:LNO samples, while the contrast reaches values of up to 30% for the Mg:LTO case. Under annealing, an exponential decay of the domain contrast was observed. The activation energy of about 1?eV being determined for the decay allowed a comparison with reported activation energies of associated defects, clearly illustrating a strong connection between thermal contrast decay and the H{sup +} and Li{sup +}-ion mobility. Finally, performing similar experiments on oxidized samples undoubtedly demonstrated that the origin of the reported luminescence contrast is strongly connected with lithium ions.

  2. Nanosecond laser-induced damage at different initial temperatures of Ta{sub 2}O{sub 5} films prepared by dual ion beam sputtering

    SciTech Connect (OSTI)

    Xu, Cheng Jia, Jiaojiao; Fan, Heliang; Qiang, Yinghuai; Liu, Jiongtian; Yang, Di; Hu, Guohang; Li, Dawei

    2014-08-07

    Ta{sub 2}O{sub 5} films were deposited by dual ion beam sputtering method. The nanosecond laser-induced damage threshold (LIDT) at different initial temperatures and time of the films was investigated by an in situ high temperature laser-induced damage testing platform. It was shown that, when the initial temperature increased from 298 K to 383 K, the LIDT at 1064 nm and 12 ns significantly decreased by nearly 14%. Then the LIDT at 1064 nm and 12 ns decreased slower with the same temperature increment. Different damage morphologies were found at different initial temperatures. At low initial temperatures, it was the defects-isolated damage while at high initial temperatures it was the defects-combined damage. The theoretical calculations based on the defect-induced damage model revealed that both the significant increase of the highest temperature and the duration contributed to the different damage morphologies. With the initial temperature being increased, the thermal-stress coupling damage mechanism transformed gradually to the thermal dominant damage mechanism.

  3. Electronic properties of III-nitride semiconductors: A first-principles investigation using the Tran-Blaha modified Becke-Johnson potential

    SciTech Connect (OSTI)

    Araujo, Rafael B. Almeida, J. S. de Ferreira da Silva, A.

    2013-11-14

    In this work, we use density functional theory to investigate the influence of semilocal exchange and correlation effects on the electronic properties of III-nitride semiconductors considering zinc-blende and wurtzite crystal structures. We find that the inclusion of such effects through the use of the Tran-Blaha modified Becke-Johnson potential yields an excellent description of the electronic structures of these materials giving energy band gaps which are systematically larger than the ones obtained with standard functionals such as the generalized gradient approximation. The discrepancy between the experimental and theoretical band gaps is then significantly reduced with semilocal exchange and correlation effects. However, the effective masses are overestimated in the zinc-blende nitrides, but no systematic trend is found in the wurtzite compounds. New results for energy band gaps and effective masses of zinc-blende and wurtzite indium nitrides are presented.

  4. Effect of the oxide layer on current-induced spin-orbit torques in Hf|CoFeB|MgO and Hf|CoFeB|TaO{sub x} structures

    SciTech Connect (OSTI)

    Akyol, Mustafa; Alzate, Juan G.; Yu, Guoqiang; Upadhyaya, Pramey; Wong, Kin L.; Khalili Amiri, Pedram; Wang, Kang L.; Ekicibil, Ahmet

    2015-01-19

    We study the effect of the oxide layer on the current-induced spin-orbit torques (SOTs) in perpendicularly magnetized Hf|CoFeB|MgO (MgO-capped) or Hf|CoFeB|TaO{sub x} (TaO{sub x}-capped) structures. The effective fields corresponding to both the field-like and damping-like current-induced SOTs are characterized using electric transport measurements. Both torques are found to be significantly stronger in MgO-capped structures than those in TaO{sub x}-capped structures. The difference in field-like and damping-like SOTs in the different structures may be attributed to the different Rashba-like Hamiltonian, arising from the difference in the electric potential profiles across the oxide|ferromagnet interfaces in the two cases, as well as possible structural and oxidation differences in the underlying CoFeB and Hf layers. Our results show that the oxide layer in heavy-metal|ferromagnet|oxide trilayer structures has a very significant effect on the generated SOTs for manipulation of ferromagnetic layers. These findings could potentially be used to engineer SOT devices with enhanced current-induced switching efficiency.

  5. Influence of ball milling on atomic structure and magnetic properties of Co{sub 40}Fe{sub 22}Ta{sub 8}B{sub 30} glassy alloy

    SciTech Connect (OSTI)

    Taghvaei, Amir Hossein, E-mail: Amirtaghvaei@gmail.com [Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of); Department of Materials Science and Engineering, Shiraz University of Technology, Shiraz (Iran, Islamic Republic of); Stoica, Mihai [IFW Dresden, Institute for Complex Materials, Helmholtzstr. 20, 01069 Dresden (Germany); Politehnica University of Timisoara, P-ta Victoriei 2, Timisoara (Romania); Bednar?ik, Jozef [HASYLAB at DESY, Notkestrasse 85, 22603 Hamburg (Germany); Kaban, Ivan [IFW Dresden, Institute for Complex Materials, Helmholtzstr. 20, 01069 Dresden (Germany); TU Dresden, Institut fr Werkstoffwissenschaft, 01062 Dresden (Germany); Shahabi, Hamed Shakur; Khoshkhoo, Mohsen Samadi [IFW Dresden, Institute for Complex Materials, Helmholtzstr. 20, 01069 Dresden (Germany); Janghorban, Kamal [Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of); Eckert, Jrgen [IFW Dresden, Institute for Complex Materials, Helmholtzstr. 20, 01069 Dresden (Germany); TU Dresden, Institut fr Werkstoffwissenschaft, 01062 Dresden (Germany)

    2014-06-01

    The influence of ball milling on the atomic structure and magnetic properties of the Co{sub 40}Fe{sub 22}Ta{sub 8}B{sub 30} metallic glass with a high thermal stability and excellent soft magnetic properties has been investigated. After 14 h of milling, the obtained powders were found to consist mainly of an amorphous phase and a small fraction of the (Co,Fe){sub 21}Ta{sub 2}B{sub 6} nanocrystals. The changes in the reduced pair correlation functions suggest noticeable changes in the atomic structure of the amorphous upon ball milling. Furthermore, it has been shown that milling is accompanied by introduction of compressive and dilatational sites in the glassy phase and increasing the fluctuation of the atomic-level hydrostatic stress without affecting the coordination number of the nearest neighbors. Ball milling has decreased the thermal stability and significantly affected the magnetic properties through increasing the saturation magnetization, Curie temperature of the amorphous phase and coercivity. - Highlights: Ball milling affected the atomic structure of Co{sub 40}Fe{sub 22}Ta{sub 8}B{sub 30} metallic glass. Mechanically-induced crystallization started after 4 h milling. Milling increased the fluctuation of the atomic-level hydrostatic stress in glass. Ball milling influenced the thermal stability and magnetic properties.

  6. A reevaluation of the assignment of the vibrational fundamentals and the rotational analysis of bands in the high-resolution infrared spectra of trans- and cis- 1,3,5-hexatriene

    SciTech Connect (OSTI)

    Craig, Norman C.; Leyden, Matthew C.; Moore, Michael C.; Patchen, Amie K.; van den Heuvel, Titus; Blake, Thomas A.; Masiello, Tony; Sams, Robert L.

    2010-07-01

    Assignments of the vibrational fundamentals of cis- and trans-1,3,5-hexatriene are reevaluated with new infrared and Raman spectra and with quantum chemical predictions of intensities and anharmonic frequencies. The rotational structure is analyzed in the high-resolution (0.0013-0.0018 cm -1) infrared spectra of three C-type bands of the trans isomer and two C-type bands of the cis isomer. The bands for the trans isomer are at 1010.96 cm-1 (v14), 900.908 cm-1 (v16), and 683.46 cm-1 (v17). Ground state (GS) rotational constants have been fitted to the combined ground state combination differences (GSCDs) for the three bands of the trans isomer. The bands for the cis isomer are at 907.70 cm-1 (v33) and 587.89 cm-1 (v35). GS rotational constants have been fitted to the combined GSCDs for the two bands of the cis isomer and compared with those obtained from microwave spectroscopy. Small inertial defects in the GSs confirm that both molecules are planar. Upper state rotational constants were fitted for all five bands.

  7. ATP for the portable 500 CFM exhauster POR-005 skid C

    SciTech Connect (OSTI)

    Keller, C.M.

    1997-06-27

    This Acceptance Test Plan is for a 500 CFM Portable Exhauster POR-005 to be used for saltwell pumping. The Portable Exhauster System will be utilized to eliminate potential flammable gases that may exist within the dome space of the tank. This Acceptance Plan will test and verify that the exhauster meets the specified design criteria, safety requirements, operations requirements, and will provide a record of the functional test results.

  8. ATP for the portable 500 CFM exhauster POR-004 skid B

    SciTech Connect (OSTI)

    Keller, C.M.

    1997-05-06

    This Acceptance Test Plan is for a 500 CFM Portable Exhauster POR-004 to be used for saltwell pumping. The Portable Exhauster System will be utilized to eliminate potential flammable gases that may exist within the dome space of the tank. This Acceptance Plan will test and verify that the exhauster meets the specified design criteria, safety requirements, operations requirements, and will provide a record of the functional test results.

  9. ATP for the portable 500 CFM exhauster POR-006 skid D

    SciTech Connect (OSTI)

    Keller, C.M.

    1997-07-29

    This Acceptance Test Plan is for a 500 CFM Portable Exhauster POR-006 to be used for saltwell pumping. The Portable Exhauster System will be utilized to eliminate potential flammable gases that may exist within the dome space of the tank. This Acceptance Plan will test and verify that the exhauster meets the specified design criteria, safety requirements, operations requirements, and will provide a record of the functional test results.

  10. Structural and magnetic properties of pyrochlore solid solutions (Y,Lu){sub 2}Ti{sub 2-x}(Nb,Ta){sub x}O{sub 7{+-}}{sub y}

    SciTech Connect (OSTI)

    West, D.V. McQueen, T.M.; Huang, Q.; Cava, R.J.

    2008-08-15

    The synthesis and characterization of the pyrochlore solid solutions, Y{sub 2}Ti{sub 2-x}Nb{sub x}O{sub 7-y}, Lu{sub 2}Ti{sub 2-x}Nb{sub x}O{sub 7-y}, Y{sub 2}Ti{sub 2-x}Ta{sub x}O{sub 7-y} and Lu{sub 2}TiTaO{sub 7-y} (-0.4Ta){sup 5+} combination, as opposed to Ti{sup 4+}/(Nb,Ta){sup 4+}, in this pyrochlore family. In addition, the evidence clearly points to Ti{sup 3+} as the source of the localized moments, with no evidence for localized Nb{sup 4+} moments. - Graphical abstract: Synthesis of pyrochlore solid solutions (Y,Lu){sub 2}Ti{sub 2-x}(Nb,Ta){sub x}O{sub 7{+-}}{sub y} under high vacuum at 1600 deg. C results in oxygen deficient, paramagnetic compounds with reduced B-site cations. Studies indicate Ti{sup 3+} as the source of the localized moments, with no evidence for localized Nb{sup 4+} moments. Annealing under O{sub 2} results in fully oxidized, oxygen excess pyrochlores as white powders. Powder neutron diffraction studies show the excess oxygen on the normally vacant 8a site.

  11. Preliminary Assessment for CAU 485: Cactus Spring Ranch Pu and Du Site, CAS No. TA-39-001-TAGR: Soil Contamination, Tonapah Test Range, Nevada

    SciTech Connect (OSTI)

    ITLV

    1998-07-01

    Corrective Action Unit 485, Corrective Action Site TA-39-001-TAGR, the Cactus Spring Ranch Soil Contamination Area, is located approximately six miles southwest of the Area 3 Compound at the eastern mouth of Sleeping Column Canyon in the Cactus Range on the Tonopah Test Range. This site was used in conjunction with animal studies involving the biological effects of radionuclides (specifically plutonium) associated with Operation Roller Coaster. According to field records, a hardened layer of livestock feces ranging from 2.54 centimeters (cm) (1 inch [in.]) to 10.2 cm (4 in.) thick is present in each of the main sheds. IT personnel conducted a field visit on December 3, 1997, and noted that the only visible feces were located within the east shed, the previously fenced area near the east shed, and a small area southwest of the west shed. Other historical records indicate that other areas may still be covered with animal feces, but heavy vegetation now covers it. It is possible that radionuclides are present in this layer, given the history of operations in this area. Chemicals of concern may include plutonium and depleted uranium. Surface soil sampling was conducted on February 18, 1998. An evaluation of historical documentation indicated that plutonium should not be and depleted uranium could not be present at levels significantly above background as the result of test animals being penned at the site. The samples were analyzed for isotopic plutonium using method NAS-NS-3058. The results of the analysis indicated that plutonium levels of the feces and surface soil were not significantly elevated above background.

  12. 14 CX TA-16.pdf

    National Nuclear Security Administration (NNSA)

  13. Preliminary Assessment for CAU 485: Cactus Spring Ranch Pu and DU Site CAS No. TA-39-001-TAGR: Soil Contamination, Tonopah Test Range, Nevada

    SciTech Connect (OSTI)

    1998-07-01

    Corrective Action Unit 485, Corrective Action Site TA-39-001-TAGR, the Cactus Spring Ranch Soil Contamination Area, is located approximately six miles southwest of the Area 3 Compound at the eastern mouth of Sleeping Column Canyon in the Cactus Range on the Tonopah Test Range. This site was used in conjunction with animal studies involving the biological effects of radionuclides (specifically plutonium) associated with Operation Roofer Coaster. The location had been used as a ranch by private citizens prior to government control of the area. According to historical records, Operation Roofer Coaster activities involved assessing the inhalation uptake of plutonium in animals from the nonnuclear detonation of nuclear weapons. Operation Roofer Coaster consisted of four nonnuclear destruction tests of a nuclear device. The four tests all took place during May and June 1963 and consisted of Double Tracks and Clean Slate 1, 11, and 111. Eighty-four dogs, 84 burros, and 136 sheep were used for the Double Tracks test, and ten sheep and ten dogs were used for Clean Slate 11. These animals were housed at Cactus Spring Ranch. Before detonation, all animals were placed in cages and transported to the field. After the shot, they were taken to the decontamination area where some may have been sacrificed immediately. All animals, including those sacrificed, were returned to Cactus Spring Ranch at this point to have autopsies performed or to await being sacrificed at a later date. A description of the Cactus Spring Ranch activities found in project files indicates the ranch was used solely for the purpose of the Roofer Coaster tests and bioaccumulation studies and was never used for any other project. No decontamination or cleanup had been conducted at Cactus Spring Ranch prior to the start of the project. When the project was complete, the pits at Cactus Spring Ranch were filled with soil, and trailers where dogs were housed and animal autopsies had been performed were removed

  14. Current-induced spin-orbit torque switching of perpendicularly magnetized Hf|CoFeB|MgO and Hf|CoFeB|TaO{sub x} structures

    SciTech Connect (OSTI)

    Akyol, Mustafa; Yu, Guoqiang; Alzate, Juan G.; Upadhyaya, Pramey; Li, Xiang; Wong, Kin L.; Khalili Amiri, Pedram; Wang, Kang L.; Ekicibil, Ahmet

    2015-04-20

    We study the effect of the oxide layer on current-induced perpendicular magnetization switching properties in Hf|CoFeB|MgO and Hf|CoFeB|TaO{sub x} tri-layers. The studied structures exhibit broken in-plane inversion symmetry due to a wedged CoFeB layer, resulting in a field-like spin-orbit torque (SOT), which can be quantified by a perpendicular (out-of-plane) effective magnetic field. A clear difference in the magnitude of this effective magnetic field (H{sub z}{sup FL}) was observed between these two structures. In particular, while the current-driven deterministic perpendicular magnetic switching was observed at zero magnetic bias field in Hf|CoFeB|MgO, an external magnetic field is necessary to switch the CoFeB layer deterministically in Hf|CoFeB|TaO{sub x}. Based on the experimental results, the SOT magnitude (H{sub z}{sup FL} per current density) in Hf|CoFeB|MgO (?14.12?Oe/10{sup 7} A cm{sup ?2}) was found to be almost 13 larger than that in Hf|CoFeB|TaO{sub x} (?1.05?Oe/10{sup 7} A cm{sup ?2}). The CoFeB thickness dependence of the magnetic switching behavior, and the resulting ?H{sub z}{sup FL} generated by in-plane currents are also investigated in this work.

  15. Measurement and simulation of the cross sections for the production of {sup 148}Gd in thin {sup nat}W and {sup 181}Ta targets irradiated with 0.4- to 2.6-GeV protons

    SciTech Connect (OSTI)

    Titarenko, Yu. E. Batyaev, V. F.; Titarenko, A. Yu.; Butko, M. A.; Pavlov, K. V.; Florya, S. N.; Tikhonov, R. S.; Zhivun, V. M.; Ignatyuk, A. V.; Mashnik, S. G.; Leray, S.; Boudard, A.; Cugnon, J.; Mancusi, D.; Yariv, Y.; Nishihara, K.; Matsuda, N.; Kumawat, H.; Mank, G.; Gudowski, W.

    2011-04-15

    The cross sections for the production of {sup 148}Gd in {sup nat}W and {sup 181}Ta targets irradiated by 0.4-, 0.6-, 0.8-, 1.2-, 1.6-, and 2.6-GeV protons at the ITEP accelerator complex have been measured by direct {alpha} spectrometry without chemical separation. The experimental data have been compared with the data obtained at other laboratories and with the theoretical simulations of the yields on the basis of the BERTINI, ISABEL, CEM03.02, INCL4.2, INCL4.5, CASCADE07, and PHITS codes.

  16. Analysis of the rotational structure in the high-resolution infrared spectra of trans-hexatriene-2-d1 and -3-d1

    SciTech Connect (OSTI)

    Craig, Norman C.; Chen, Yihui; van Besien, Herman; Blake, Thomas A.

    2014-09-01

    The 2-d1 and 3-d1 isotopologues of trans-hexatriene have been synthesized, and their high-resolution (0.0015 cm-1) IR spectra have been recorded. For each of the isotopologues the rotational structure in four C-type bands for out-of-plane vibrational modes has been analyzed, and the ground state combination differences (GSCDs) have been pooled. Ground state rotational constants have been fitted to the GSCDs. For the 2-d species, A0, B0, and C0 values of 0.7837254(5), 0.0442806(3), and 0.0419299(2) cm-1 were fitted to 2450 GSCDs. For the 3-d species, A0, B0, and C0 values of 0.7952226(8), 0.0446149(7), and 0.0422661(4) cm-1 were fitted to 2234 GSCDs. For the eleven out-of-plane modes of the two isotopologues, predictions of anharmonic wavenumbers and harmonic intensities have been computed and compared with experiment where possible.

  17. Dynamics of the time-resolved stimulated Raman scattering spectrum in presence of transient vibronic inversion of population on the example of optically excited trans-β-apo-8{sup ′}-carotenal

    SciTech Connect (OSTI)

    Kardaś, T. M. Ratajska-Gadomska, B.; Gadomski, W.; Lapini, A.; Righini, R.; Di Donato, M.; Ragnoni, E.; Foggi, P.

    2014-05-28

    We have studied the effect of transient vibrational inversion of population in trans-β-apo-8{sup ′}-carotenal on the time-resolved femtosecond stimulated Raman scattering (TR-FSRS) signal. The experimental data are interpreted by applying a quantum mechanical approach, using the formalism of projection operators for constructing the theoretical model of TR-FSRS. Within this theoretical frame we explain the presence of transient Raman losses on the Stokes side of the TR-FSRS spectrum as the effect of vibrational inversion of population. In view of the obtained experimental and theoretical results, we conclude that the excited S{sub 2} electronic level of trans-β-apo-8{sup ′}-carotenal relaxes towards the S{sub 0} ground state through a set of four vibrational sublevels of S{sub 1} state.

  18. Lattice-level observation of the elastic-to-plastic relaxation process with subnanosecond resolution in shock-compressed Ta using time-resolved in situ Laue diffraction

    SciTech Connect (OSTI)

    Wehrenberg, C. E.; Comley, A. J.; Barton, N. R.; Coppari, F.; Fratanduono, D.; Huntington, C. M.; Maddox, B. R.; Park, H. -S.; Plechaty, C.; Prisbrey, S. T.; Remington, B. A.; Rudd, R. E.

    2015-09-29

    We report direct lattice level measurements of plastic relaxation kinetics through time-resolved, in-situ Laue diffraction of shock-compressed single-crystal [001] Ta at pressures of 27-210 GPa. For a 50 GPa shock, a range of shear strains is observed extending up to the uniaxial limit for early data points (<0.6 ns) and the average shear strain relaxes to a near steady state over ~1 ns. For 80 and 125 GPa shocks, the measured shear strains are fully relaxed already at 200 ps, consistent with rapid relaxation associated with the predicted threshold for homogeneous nucleation of dislocations occurring at shock pressure ~65 GPa. The relaxation rate and shear stresses are used to estimate the dislocation density and these quantities are compared to the Livermore Multiscale Strength model as well as various molecular dynamics simulations.

  19. X-ray diffraction on the X-cut of a Ca{sub 3}TaGa{sub 3}Si{sub 2}O{sub 14} single crystal modulated by a surface acoustic wave

    SciTech Connect (OSTI)

    Irzhak, D. Roshchupkin, D.

    2014-06-28

    The result of X-ray diffraction study on a single crystal of the calcium-gallogermanate family Ca{sub 3}TaGa{sub 3}Si{sub 2}O{sub 14} (CTGS) modulated by a surface acoustic wave (SAW) is presented. The power flow angle for SAW propagating along the X{sub 2} axis of the X-cut in CTGS was measured. The rocking curves for the CTGS crystal were recorded at different amplitudes of an input high frequency electric signal on interdigital transducer used to excite a SAW. Based on the data obtained, intensity dependence of diffraction satellites on the amplitude of electric signal exciting a SAW was built. Numerical simulation of the crystal rocking curves and dependence of diffraction satellite intensities on the SAW amplitude enabled the selection of a set of material constants at which the most complete coincidence of experimental and calculated results is observed.

  20. Synthesis and characterization of compounds Sr{sub 2}{ital RM}Cu{sub 2}O{sub 8{minus}{delta}} ({ital R}=Pr, Nd, Sm, Eu, Gd; {ital M}=Nb, Ta)

    SciTech Connect (OSTI)

    Vybornov, M.; Perthold, W.; Michor, H.; Holubar, T.; Hilscher, G.; Rogl, P.; Fischer, P.; Divis, M.

    1995-07-01

    Although traces of superconductivity ({lt}0.2%) have been detected in Ba{sub 2}La{ital M}{sub 1{minus}{ital x}}W{sub {ital x}}Cu{sub 2}O{sub 8{minus}{delta}} ({ital x}{similar_to}0.3,{ital M}=Nb,Ta) below 30 K, the superconducting impurity phase could not be resolved. The antiferromagnetic (AF) order of the rare-earth sublattice in this {ital R}-2112 system (e.g., {ital T}{sub {ital N}}{sup Gd}=2.18 K) appears to be similar to that of the {ital R}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} series (e.g., {ital T}{sub {ital N}}{sup Gd}=2.29 K); however, the exceptional high AF order of Pr in Pr-123 (with 17 K) is reduced to below 2.3 K for Sr{sub 2}Pr{ital M} Cu{sub 2}O{sub 8{minus}{delta}}. The temperature and field dependence of the specific heat and the susceptibility is discussed in terms of crystal field splitting derived from the {ital R}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} compounds. Overall crystal field splitting in the title compounds is comparable with that of the {ital R}-123 compounds.

  1. Investigation into the evolution of the structure of K{sub 1-x}Li{sub x}Ta{sub 1-y}Nb{sub y}O{sub 3} single crystals under variations in temperature

    SciTech Connect (OSTI)

    Borisov, S. A.; Vakhrushev, S. B.; Koroleva, E. Yu.; Naberezhnov, A. A. Syrnikov, P. P.; Simkin, V. G.; Kutnjak, Z.; Egami, T.; Dmowski, W.; Piekarz, P.

    2007-05-15

    The evolution of the structure of K{sub 1-x}Li{sub x}Ta{sub 1-y}Nb{sub y}O{sub 3} single crystals with x = 0.001, y = 0.026, and 1900 ppm Cu (KLTN277) and with x = 0.0014 and y = 0.024 (KLTN123), which exhibit an extremely high permittivity (up to 4 x 10{sup 5} in the quasi-static regime for the KLTN277 crystal), is investigated in the range from room temperature to 20 K. It is demonstrated that, upon cooling to the lowest temperatures, both crystals retain their cubic structure, but the lattice parameters pass through a minimum at the temperature of the observed anomalies of the dielectric response ({approx}50 K). In the neutron diffraction pattern of the KLTN123 sample, satellites appear in the vicinity of the (hhh) reflections at temperatures below {approx}50 K. These satellites can be associated with the nucleation of the rhombohedral phase.

  2. Band alignment of epitaxial SrTiO3 thin films with (LaAlO3)0.3-(Sr2AlTaO6)0.7 (001)

    SciTech Connect (OSTI)

    Comes, Ryan B.; Xu, Peng; Jalan, Bharat; Chambers, Scott A.

    2015-09-28

    SrTiO3 (STO) epitaxial thin films and heterostructures are of considerable interest due to the wide range of functionalities they exhibit. The alloy perovskite (LaAlO3)0.3-(Sr2AlTaO6)0.7 (LSAT) is commonly used as a substrate for these material structures due to its structural compatibility. However, surprisingly little is known about the electronic properties of the STO/LSAT interface despite its potentially important role in affecting the overall electronic structure of system. We examine the band alignment of STO/LSAT heterostructures using x-ray photoelectron spectroscopy for epitaxial STO films deposited using two different molecular beam epitaxy approaches. We find that the valence band offset ranges from +0.2(1) eV to -0.2(1) eV depending on surface conditions for the film and substrate. From these results we extract a conduction band offset from -2.4(1) eV to -2.8(1) eV, indicating that the conduction band edge is more deeply bound in STO and that LSAT will not act as a sink or trap for electrons in the supported film or multilayer.

  3. Excitation functions of the natTa(p,x)178m2Hf and natW(p,x)178m2Hf reactions at energies up to 2600 MeV

    SciTech Connect (OSTI)

    Titarenko, Yu. E.; Batyaev, V. F.; Pavlov, K. V.; Titarenko, A. Yu.; Zhivun, V. M.; Chauzova, M. V.; Ignatyuk, A. V.; Mashnik, Stepan Georgievich; Leray, S.; Boudard, A.; David, J. -C.; Mancusi, D.; Cugnon, J.; Yariv, Y.; Nishihara, K.; Matsuda, N.; Kumawat, H.; Stankovskiy, A. Yu.

    2015-04-29

    Due to potential level of energy intensity 178m2Hf is an extremely interesting isomer. One possible way to produce this isomer is irradiation of natTa or natW samples with high energy protons. Irradiation of natTa or natW samples performed for other purposes provides an opportunity to study the corresponding reactions. This paper presents the 178m2Hf independent production cross sections for both targets measured by the gamma-ray spectrometry method. The reaction excitation functions have been obtained for the proton energies from 40 up to 2600 MeV. The experimental results were compared with calculations by various versions of the intranuclear cascade model in the well-known codes: ISABEL, Bertini, INCL4.5+ABLA07, PHITS, CASCADE07 and CEM03.02. The isomer ratio for the natTa(p,x) 178m2Hf reaction is evaluated on the basis of the available data.

  4. TA-55: LANL Plutonium-Processing Facilities

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Among other things, these efforts support requests for power sources for unmanned or unmaintained situations, such as NASA space missions. Capabilities In support of national ...

  5. 13 CX TA-55-4.pdf

    National Nuclear Security Administration (NNSA)

  6. COMET TA Floor Plan 100225.vc6

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    West Hall Door Emg Exit W Trench Room 1107 S Structural Beam Rack Argus Chamber Interaction Chamber Work Station 8 3 0 2 - V B L as phere CL 420mm f rom N i nner wall. Lens h...

  7. Thermodynamic properties and ideal-gas enthalpies of formation for butyl vinyl ether, 1,2-dimethoxyethane, methyl glycolate, bicyclo[2.2.1]hept-2-ene, 5-vinylbicyclo[2.2.1]hept-2-ene, trans-azobenzene, butyl acrylate, di-tert-butyl ether, and hexane-1,6-diol

    SciTech Connect (OSTI)

    Steele, W.V.; Chirico, R.D.; Knipmeyer, S.E.; Nguyen, A.; Smith, N.K.

    1996-11-01

    Ideal-gas enthalpies of formation of butyl vinyl ether, 1,2-dimethoxyethane, methyl glycolate, bicyclo-[2.2.1]hept-2-ene, 5-vinylbicyclo[2.2.1]hept-2-ene, trans-azobenzene, butyl acrylate, di-tert-butyl ether, and hexane-1,6-diol are reported. Enthalpies of fusion were determined for bicyclo[2.2.1]hept-2-ene and trans-azobenzene. Two-phase (solid + vapor) or (liquid + vapor) heat capacities were determined from 300 K to the critical region or earlier decomposition temperature for each compound studied. Liquid-phase densities along the saturation line were measured for bicyclo[2.2.1]hept-2-ene. For butyl vinyl ether and 1,2-dimethoxyethane, critical temperatures and critical densities were determined from the dsc results and corresponding critical pressures derived from the fitting procedures. Fitting procedures were used to derive critical temperatures, critical pressures, and critical densities for bicyclo[2.2.1]hept-2-ene, 5-vinylbicyclo[2.2.1]hept-2-ene, trans-azobenzene, butyl acrylate, and di-tert-butyl ether. Group-additivity parameters or ring-correction terms useful in the application of the Benson group-contribution correlations were derived.

  8. Deseret Generation & Tran Coop | Open Energy Information

    Open Energy Info (EERE)

    Generation Yes Activity Transmission Yes Activity Buying Transmission Yes Activity Wholesale Marketing Yes This article is a stub. You can help OpenEI by expanding it. Utility...

  9. TransAtlantic Petroleum | Open Energy Information

    Open Energy Info (EERE)

    Area Product: acquisition, development, exploration, and production of crude oil and natural gas. Year Founded: 1985 Phone Number: 214-220-4323 Website: www.transatlanticpetro...

  10. Massachusetts Bay Trans Auth | Open Energy Information

    Open Energy Info (EERE)

    NPCC Yes Operates Generating Plant Yes Activity Generation Yes Activity Wholesale Marketing Yes Activity Retail Marketing Yes Alt Fuel Vehicle Yes Alt Fuel Vehicle2 Yes This...