Sample records for tungsten halogen spotlights

  1. Applications of Cu{sub 2}O octahedral particles on ITO glass in photocatalytic degradation of dye pollutants under a halogen tungsten lamp

    SciTech Connect (OSTI)

    Zhai, Wei [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Sun, Fengqiang, E-mail: fqsun@scnu.edu.cn [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, South China Normal University (China); Exhibition Base of Production, Study and Research on New Polymer Materials and Postgraduate Students’ Innovation Training of Guangdong Higher Education Institutes (China); Chen, Wei; Zhang, Lihe; Min, Zhilin; Li, Weishan [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China)

    2013-11-15T23:59:59.000Z

    Graphical abstract: - Highlights: • Photocatalytic activity of Cu{sub 2}O octahedral microcrystals on ITO glass was studied. • They showed high abilities in degradation of methylene blue in the presence of H{sub 2}O{sub 2}. • H{sub 2}O{sub 2} amount could affect the degradation efficiency. • Such particles could be easily recycled and still kept high activity. • Many dye pollutants and their mixtures could be efficiently degraded. - Abstract: Cu{sub 2}O octahedral microcrystals were prepared on the ITO glass by galvanostatic electrodeposition in CuSO{sub 4} solution with poly(vinylpryrrolidone) as the surfactant. By controlling the electrodeposition time, the microcrystals could be randomly distributed on the ITO glass and separated from each other, resulting in as many as possible (1 1 1) crystalline planes were exposed. Such microcrystals immobilized on ITO glass were employed in photodegradation of dye pollutants in the presence of H{sub 2}O{sub 2} under a 150 W halogen tungsten lamp. The photodegradation of methylene blue was taken as an example to evaluate the photocatalytic activities of the octahedral Cu{sub 2}O microcrystals. Effects of electrodeposition time and H{sub 2}O{sub 2} amount on the degradation efficiency was discussed, giving the optimum conditions and the corresponding degradation mechanism. The catalyst showed high ability in degradation of methylene blue, methyl orange, rhodamine B, eosin B and their mixtures under identical conditions.

  2. Spotlights Archive

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdfBreakingMayDepartment of EnergySiteCarollm/spotlights-archive Office of Legacy

  3. Energy efficient alternatives to halogen torchieres

    SciTech Connect (OSTI)

    Siminovitch, M.; Marr, L.; Mitchell, J.; Page, E.

    1997-03-01T23:59:59.000Z

    A series of novel energy efficient torchiere systems have been developed using compact fluorescent lamps (CFLs). These systems were studied photometrically and compared with the performance of traditional commercially available tungsten halogen sources. Gonio-photometric data and power assessments indicate that significant lighting energy savings can be obtained by utilizing CFL sources instead of standard tungsten halogen sources. This energy savings is jointly due to the higher source efficacy of the CFLs and the surprisingly poor performance of the imported 300 Watt halogen lamps. Experimental data shows that a 50 to 60 Watt CFL will effectively lumen match a variety of 300 Watt tungsten halogen sources with 5 to 10 times the efficacy. CFL torchieres have additional benefits of higher power quality and cooler lamp operating temperature, making them safer fixtures.

  4. Spotlight: Bryant Roybal

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

    Spotlight: Bryant Roybal March 1, 2015 Champion chile New Mexico's first green chile stew champion, Bryant Roybal, is proud to add first prize at the First Annual Great Bowls of...

  5. Spotlight: Jenna Casias

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our Instagram Secretary900 Special Report:Spotlight: Bryant Roybal AlumniSpotlight:

  6. Spotlight: Christopher Lee

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our Instagram Secretary900 Special Report:Spotlight: Bryant Roybal Alumni

  7. Spotlight on Michigan: Sweeping the State for Ultimate Success...

    Energy Savers [EERE]

    Spotlight on Michigan: Sweeping the State for Ultimate Success Spotlight on Michigan: Sweeping the State for Ultimate Success Spotlight on Michigan: Sweeping the State for Ultimate...

  8. Spotlight, March 2012

    E-Print Network [OSTI]

    2012-03-01T23:59:59.000Z

    of Kansas Lawrence Campus. Energy Solutions Professionals (ESP), an Overland Park?based energy service company, and the KU Center for Sustainability are coordinating the competition to see which building can save the most energy over a twelve?week period... the results can be found at www.energy.ku.edu/lightsout/. Page 2 KU Center for Sustainability Sustainability Spotlight March 2012 1) Green Hall 13.5% 2) Bailey Hall 8.7% 3) Summerfield Hall 6.8% Building Overall Savings The Deans of the participating schools go toe...

  9. Spotlight: Bryant Roybal

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our Instagram Secretary900 Special Report:Spotlight: Bryant Roybal Alumni Link:

  10. Scientists in the Spotlight

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiationImplementingnpitcheResearchPhysics Lab Scientist'sScientists in the Spotlight

  11. Los Alamos Lab: MPA: Spotlight

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

    Spotlight on our people Jonathan Betts, MPA-NHMFL Jonathan Betts could be considered a jack-of-all-trades. The English native has gone from wiring thermometers for a small company...

  12. Spotlights Archive | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our Instagram Secretary900 Special Report:Spotlight: Bryant RoybalSpotlights Archive

  13. DOE Sustainability SPOtlight: Special Edition 2013 DOE Sustainability...

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

    DOE Sustainability SPOtlight: Special Edition 2013 DOE Sustainability Awards DOE Sustainability SPOtlight: Special Edition 2013 DOE Sustainability Awards Newsletter highlights the...

  14. Better Buildings: Workforce, Spotlight on Maine: Contractor Sales...

    Energy Savers [EERE]

    Workforce, Spotlight on Maine: Contractor Sales Training Boosts Energy Upgrade Conversions Better Buildings: Workforce, Spotlight on Maine: Contractor Sales Training Boosts Energy...

  15. Better Buildings: Financing and Incentives: Spotlight on Maine...

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

    to a Sustainable Level of Incentives More Documents & Publications Spotlight on Maine: Transition to a Sustainable Level of Incentives Better Buildings: Workforce, Spotlight on...

  16. Better Buildings: Workforce: Spotlight on Fayette County, Pennsylvania...

    Energy Savers [EERE]

    Better Buildings: Workforce: Spotlight on Fayette County, Pennsylvania: Developing the Skills and Tools for Workforce Success Better Buildings: Workforce: Spotlight on Fayette...

  17. Better Buildings: Workforce: Spotlight on Portland, Oregon: Making...

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

    Spotlight on Portland, Oregon: Making the Program Work for Contractors Better Buildings: Workforce: Spotlight on Portland, Oregon: Making the Program Work for Contractors...

  18. Halogenated solvent remediation

    DOE Patents [OSTI]

    Sorenson, Kent S.

    2004-08-31T23:59:59.000Z

    Methods for enhancing bioremediation of ground water contaminated with nonaqueous halogenated solvents are disclosed. A preferred method includes adding a composition to the ground water wherein the composition is an electron donor for microbe-mediated reductive dehalogenation of the halogenated solvents and enhances mass transfer of the halogenated solvents from residual source areas into the aqueous phase of the ground water. Illustrative compositions effective in these methods include surfactants such as C.sub.2 -C.sub.4 carboxylic acids and hydroxy acids, salts thereof, esters of C.sub.2 -C.sub.4 carboxylic acids and hydroxy acids, and mixtures thereof. Especially preferred compositions for use in these methods include lactic acid, salts of lactic acid, such as sodium lactate, lactate esters, and mixtures thereof. The microbes are either indigenous to the ground water, or such microbes can be added to the ground water in addition to the composition.

  19. Halogenated solvent remediation

    DOE Patents [OSTI]

    Sorenson, Jr., Kent S. (Windsor, CO)

    2008-11-11T23:59:59.000Z

    Methods for enhancing bioremediation of ground water contaminated with nonaqueous halogenated solvents are disclosed. An illustrative method includes adding an electron donor for microbe-mediated anaerobic reductive dehalogenation of the halogenated solvents, which electron donor enhances mass transfer of the halogenated solvents from residual source areas into the aqueous phase of the ground water. Illustrative electron donors include C.sub.2-C.sub.4 carboxylic acids and hydroxy acids, salts thereof, esters of C.sub.2-C.sub.4 carboxylic acids and hydroxy acids, and mixtures thereof, of which lactic acid, salts of lactic acid--such as sodium lactate, lactate esters, and mixtures thereof are particularly illustrative. The microbes are either indigenous to the ground water, or such microbes can be added to the ground water in addition to the electron donor.

  20. Halogenation of cobalt dicarbollide

    DOE Patents [OSTI]

    Hurlburt, Paul K. (Los Alamos, NM); Abney, Kent D. (Los Alamos, NM); Kinkead, Scott A. (Los Alamos, NM)

    1997-01-01T23:59:59.000Z

    A method for selectively adding chlorine, bromine, or iodine to cobalt dicarbollide anions by means of electrophilic substitution reactions. Halogens are added only to the B10 and B10' positions of the anion. The process involves use of hypohalous acid or N-halosuccinimide or gaseous chlorine in the presence of iron.

  1. Halogenation of cobalt dicarbollide

    DOE Patents [OSTI]

    Hurlburt, P.K.; Abney, K.D.; Kinkead, S.A.

    1997-05-20T23:59:59.000Z

    A method for selectively adding chlorine, bromine, or iodine to cobalt dicarbollide anions by means of electrophilic substitution reactions. Halogens are added only to the B10 and B10{prime} positions of the anion. The process involves use of hypohalous acid or N-halosuccinimide or gaseous chlorine in the presence of iron. 1 fig.

  2. Spotlights Archive | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdfBreakingMayDepartment of EnergySiteCarollm/spotlights-archive Office of

  3. Spotlights Archive | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdfBreakingMayDepartment of EnergySiteCarollm/spotlights-archive Office ofJanuary

  4. Spotlights Archive | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdfBreakingMayDepartment of EnergySiteCarollm/spotlights-archive Office

  5. Spotlights Archive | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdfBreakingMayDepartment of EnergySiteCarollm/spotlights-archive OfficeApril 8, 2014

  6. Spotlights Archive | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdfBreakingMayDepartment of EnergySiteCarollm/spotlights-archive OfficeApril 8,

  7. Spotlights Archive | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdfBreakingMayDepartment of EnergySiteCarollm/spotlights-archive OfficeApril 8,April

  8. Spotlights Archive | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onYouTube YouTube Note: Since the.pdfBreakingMayDepartment of EnergySiteCarollm/spotlights-archive OfficeApril

  9. MULTIPHOTON DISSOCIATION PRODUCTS FROM HALOGENATED HYDROCARBONS

    E-Print Network [OSTI]

    Sudbo, Aa. S.

    2011-01-01T23:59:59.000Z

    FROM HALOGENATED HYDROCARBONS RECE1VED Aa. S. Sudbo, P. A.FROM HALOGENATED HYDROCARBONS LBL-6966 Aa. S. Sudbo, t P. A.

  10. SPOTLIGHT on: Lindsay Freeman Chemical Engineering (Nanotechnology)

    E-Print Network [OSTI]

    Wang, Hai

    SPOTLIGHT on: Lindsay Freeman Chemical Engineering (Nanotechnology) Undergraduate Hometown.D. in chemical engineering with an emphasis in nanotechnology. Lindsay stands out as a very well-balanced student

  11. Spotlight on Rutland County, Vermont: How Local Ties Lead to...

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

    Rutland County, Vermont: How Local Ties Lead to Local Wins Spotlight on Rutland County, Vermont: How Local Ties Lead to Local Wins Spotlight on Rutland County, Vermont: How Local...

  12. SCHOLAR SPOTLIGHT TRAINING SCHOOL STAFF IN

    E-Print Network [OSTI]

    Illinois at Chicago, University of

    can student teachers and school social worker interns learn to support their students' social-service training in SEL for UIC students that focused on race and class. The group training occurred over sixMarch 2014 SCHOLAR SPOTLIGHT TRAINING SCHOOL STAFF IN SOCIAL-EMOTIONAL LEARNING Introduction How

  13. Children's School March 2012 Research Spotlight

    E-Print Network [OSTI]

    Children's School March 2012 Research Spotlight The Fish Game Dr. Anna Fisher is investigating, attention, processing speed, executive function, and language ability. In this "fish game", graduate children are presented with a series of fish similar to the ones pictured below. Children are told

  14. Children's School December 2013 Undergraduate Spotlight

    E-Print Network [OSTI]

    Children's School December 2013 Undergraduate Spotlight Arielle Cohen has always loved working with children and is so happy to be working with the wonderful group of children at the Children's School! She of a national non-profit that aims to help disadvantaged high school students through the college application

  15. Children's School February 2014 Undergraduate Spotlight

    E-Print Network [OSTI]

    and the Children's School. ! Child Development Interns Dr. Carver has five interns in her Practicum in ChildChildren's School February 2014 Undergraduate Spotlight Rafael McCauley started working at the Children's School midway through the first semester, and already knows it's the best job a student can have

  16. Children's School February 2012 Undergraduate Spotlight

    E-Print Network [OSTI]

    at an elementary school, Esther taught robotics workshops for middle school students throughout her time in high to know the friends at the Childrens School. Esther is also taking Dr. Carvers course, Principles of ChildChildren's School February 2012 Undergraduate Spotlight Esther de la Torre is an assistant

  17. Better Buildings: Financing and Incentives: Spotlight on Michigan...

    Energy Savers [EERE]

    betterbuildings.energy.govneighborhoods 1 Spotlight on Michigan: Experiment to Find the Right Mix of Incentives With support from the U.S. Energy Department's Better Buildings...

  18. Better Buildings: Financing and Incentives: Spotlight on Michigan...

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

    Michigan: Experiment to Find the Right Mix of Incentives Better Buildings: Financing and Incentives: Spotlight on Michigan: Experiment to Find the Right Mix of Incentives Better...

  19. Investigations into the Nature of Halogen Bonding Including Symmetry...

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

    into the Nature of Halogen Bonding Including Symmetry Adapted Perturbation Theory Analyses. Investigations into the Nature of Halogen Bonding Including Symmetry Adapted...

  20. Spotlighting Howard University | Department of Energy

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33Frequently AskedEnergyIssues DOE's Nuclear EnergySmartOverviewEnergySpotlighting Howard

  1. 2, 14571486, 2005 Halogens in peat

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    BGD 2, 1457­1486, 2005 Halogens in peat porewater H. Biester et al. Title Page Abstract Discussions is the access reviewed discussion forum of Biogeosciences Halogens in porewater of peat bogs ­ the role of peat decomposition and dissolved organic matter H. Biester 1 , D. Selimovi´c 1 , S. Hemmerich 1

  2. Nuclear Fuels & Materials Spotlight Volume 4

    SciTech Connect (OSTI)

    I. J. van Rooyen,; T. M. Lillo; Y. Q. WU; P.A. Demkowicz; L. Scott; D.M. Scates; E. L. Reber; J. H. Jackson; J. A. Smith; D.L. Cottle; B.H. Rabin; M.R. Tonks; S.B. Biner; Y. Zhang; R.L. Williamson; S.R. Novascone; B.W. Spencer; J.D. Hales; D.R. Gaston; C.J. Permann; D. Anders; S.L. Hayes; P.C. Millett; D. Andersson; C. Stanek; R. Ali; S.L. Garrett; J.E. Daw; J.L. Rempe; J. Palmer; B. Tittmann; B. Reinhardt; G. Kohse; P. Ramuhali; H.T. Chien; T. Unruh; B.M. Chase; D.W. Nigg; G. Imel; J. T. Harris

    2014-04-01T23:59:59.000Z

    As the nation's nuclear energy laboratory, Idaho National Laboratory brings together talented people and specialized nuclear research capability to accomplish our mission. This edition of the Nuclear Fuels and Materials Division Spotlight provides an overview of some of our recent accomplishments in research and capability development. These accomplishments include: • The first identification of silver and palladium migrating through the SiC layer in TRISO fuel • A description of irradiation assisted stress corrosion testing capabilities that support commercial light water reactor life extension • Results of high-temperature safety testing on coated particle fuels irradiated in the ATR • New methods for testing the integrity of irradiated plate-type reactor fuel • Description of a 'Smart Fuel' concept that wirelessly provides real time information about changes in nuclear fuel properties and operating conditions • Development and testing of ultrasonic transducers and real-time flux sensors for use inside reactor cores, and • An example of a capsule irradiation test. Throughout Spotlight, you'll find examples of productive partnerships with academia, industry, and government agencies that deliver high-impact outcomes. The work conducted at Idaho National Laboratory helps to spur innovation in nuclear energy applications that drive economic growth and energy security. We appreciate your interest in our work here at INL, and hope that you find this issue informative.

  3. White House Spotlights Solar Innovation as Summit Registration...

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

    In case you missed it, last Thursday's White House Solar Champions of Change and Solar Summit shed a spotlight on all the amazing work that solar innovators around country are...

  4. SPOTLIGHT on: Jennifer Dowling Industrial and Systems Engineering

    E-Print Network [OSTI]

    Wang, Hai

    SPOTLIGHT on: Jennifer Dowling Industrial and Systems Engineering Hometown: La Mirada, CA Involvement at USC: Society of Women Engineers- Corporate Affairs Committee member, Institute of Industrial Engineers- President, Viterbi Graduate Admissions Office- student staff member, Song Girl 2007 Favorite

  5. in the spotlight: can our excited synapses comprehendthem? s

    E-Print Network [OSTI]

    Granick, Steve

    in the spotlight: can our excited synapses comprehendthem? s Patricia C. Salinas is in the Department of Biological Sciences, Imperial College London, London SW8 2AZ, UK. e-mail: p.salinas

  6. Photodissociation Dynamics of Halogen Oxide Species 

    E-Print Network [OSTI]

    Dooley, Kristin S.

    2010-07-14T23:59:59.000Z

    The focus of this dissertation is the study of the photodissociation dynamics of halogen oxide species (XO, X = Cl, Br, I). These radical species are known to be important in stratospheric and tropospheric ozone depletion ...

  7. Tungsten Cathode Catalyst for PEMFC

    SciTech Connect (OSTI)

    Joel B. Christian; Sean P. E. Smith

    2006-09-22T23:59:59.000Z

    Final report for project to evaluate tungsten-based catalyst as a cathode catalyst for PEM cell applications.

  8. Aluminum-tungsten fiber composites with cylindrical geometry and controlled architecture of tungsten reinforcement

    E-Print Network [OSTI]

    Lucchese, Carl Joesph

    2010-01-01T23:59:59.000Z

    Measurements in Alumina and Tungsten Fibre-Reinforcedto-Ductile Transition in Tungsten Single Crystals. ” ScienceToughness of Polycrystalline Tungsten Under Mode I and Mixed

  9. HELSINKI UNIVERSITY OF TECHNOLOGY ENE-47.153 Halogens, dioxins/Halogens, dioxins/furansfurans

    E-Print Network [OSTI]

    Zevenhoven, Ron

    .153 Halogens in fossil fuels (mg/kg)Halogens in fossil fuels (mg/kg) (listed as F, Cl, Br) Coal*, lignite 20 OrimulsionTM ~700 Petroleum coke, "petcoke" ~ 300 Natural gas - * Iodine 0.5 - 1.5 mg/kg #12;HELSINKI-related corrosion #3 Corrosion rateCorrosion rate versusversus chlorine in coalchlorine in coal #12;HELSINKI

  10. Crystallographic studies on enzymatic halogenation of natural products

    E-Print Network [OSTI]

    Blasiak, Leah Cameron

    2008-01-01T23:59:59.000Z

    Halogenated natural products are common and serve roles as hormones, pesticides, antibiotics, and anti-tumor agents. The incorporation of a halogen atom into an organic scaffold can tune the molecule's potency and selectivity, ...

  11. anesthesiques halogenes pendant: Topics by E-print Network

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

    are considered. We predict the major alkali and halogen species in a Pele-like volcanic gas and the major alklai and halogen condensates. We also model disequilibrium chemistry...

  12. active halogen species: Topics by E-print Network

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

    are considered. We predict the major alkali and halogen species in a Pele-like volcanic gas and the major alklai and halogen condensates. We also model disequilibrium chemistry...

  13. Method and apparatus for low temperature destruction of halogenated hydrocarbons

    DOE Patents [OSTI]

    Reagen, William Kevin (Stillwater, MN); Janikowski, Stuart Kevin (Idaho Falls, ID)

    1999-01-01T23:59:59.000Z

    A method and apparatus for decomposing halogenated hydrocarbons are provided. The halogenated hydrocarbon is mixed with solvating agents and maintained in a predetermined atmosphere and at a predetermined temperature. The mixture is contacted with recyclable reactive material for chemically reacting with the recyclable material to create dehalogenated hydrocarbons and halogenated inorganic compounds. A feature of the invention is that the process enables low temperature destruction of halogenated hydrocarbons.

  14. Halogenation of Imidazolium Ionic Liquids. Thermodynamics Perspective

    E-Print Network [OSTI]

    Chaban, Vitaly V

    2015-01-01T23:59:59.000Z

    Imidazolium cations are promising for anion exchange membranes, and electrochemical applications and gas capture. They can be chemically modified in many ways including halogenation. Halogenation possibilities of the imidazole ring constitute a particular interest. This work investigates fluorination and chlorination reactions of all symmetrically non-equivalent sites of the imidazolium cation. Halogenation of all carbon atoms is thermodynamically permitted. Out of these, the most favorable site is the first methylene group of the alkyl chain. In turn, the least favorable site is carbon of the imidazole ring. Temperature dependence of enthalpy, entropy, and Gibbs free energy at 1 bar is discussed. The reported results provide an important guidance in functionalization of ionic liquids in search of task-specific compounds.

  15. Helium bubble bursting in tungsten

    SciTech Connect (OSTI)

    Sefta, Faiza [University of California, Berkeley, California 94720 (United States); Juslin, Niklas [University of Tennessee, Knoxville, Tennessee 37996 (United States); Wirth, Brian D., E-mail: bdwirth@utk.edu [University of Tennessee, Oak Ridge National Laboratory, Knoxville, Tennessee 37996 (United States)

    2013-12-28T23:59:59.000Z

    Molecular dynamics simulations have been used to systematically study the pressure evolution and bursting behavior of sub-surface helium bubbles and the resulting tungsten surface morphology. This study specifically investigates how bubble shape and size, temperature, tungsten surface orientation, and ligament thickness above the bubble influence bubble stability and surface evolution. The tungsten surface is roughened by a combination of adatom “islands,” craters, and pinholes. The present study provides insight into the mechanisms and conditions leading to various tungsten topology changes, which we believe are the initial stages of surface evolution leading to the formation of nanoscale fuzz.

  16. Retention of Halogens in Waste Glass

    SciTech Connect (OSTI)

    Hrma, Pavel R.

    2010-05-01T23:59:59.000Z

    In spite of their potential roles as melting rate accelerators and foam breakers, halogens are generally viewed as troublesome components for glass processing. Of five halogens, F, Cl, Br, I, and At, all but At may occur in nuclear waste. A nuclear waste feed may contain up to 10 g of F, 4 g of Cl, and ?100 mg of Br and I per kg of glass. The main concern is halogen volatility, producing hazardous fumes and particulates, and the radioactive iodine 129 isotope of 1.7x10^7-year half life. Because F and Cl are soluble in oxide glasses and tend to precipitate on cooling, they can be retained in the waste glass in the form of dissolved constituents or as dispersed crystalline inclusions. This report compiles known halogen-retention data in both high-level waste (HLW) and low-activity waste (LAW) glasses. Because of its radioactivity, the main focus is on I. Available data on F and Cl were compiled for comparison. Though Br is present in nuclear wastes, it is usually ignored; no data on Br retention were found.

  17. Thermoelectric Research Takes Spotlight Improvements in Efficiency Help Fuel Results

    E-Print Network [OSTI]

    Thermoelectric Research Takes Spotlight Improvements in Efficiency Help Fuel Results m i c h i g of alternative energy sources, thermoelectrics may not immediately come to mind, but MSU and the College interest in alternative energy sources certainly has helped to bring thermoelectrics into the limelight

  18. Preparation, Characterization, and Catalytic Properties of Tungsten...

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

    Preparation, Characterization, and Catalytic Properties of Tungsten Trioxide Cyclic Trimers on FeO(111)Pt(111). Preparation, Characterization, and Catalytic Properties of Tungsten...

  19. Comproportionation of Cationic and Anionic Tungsten Complexes...

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

    Comproportionation of Cationic and Anionic Tungsten Complexes Having an N-Heterocyclic Carbene Ligand to Give the Isolable 17 Comproportionation of Cationic and Anionic Tungsten...

  20. Preparation of tungsten oxide

    DOE Patents [OSTI]

    Bulian, Christopher J. (Yankton, SD); Dye, Robert C. (Los Alamos, NM); Son, Steven F. (Los Alamos, NM); Jorgensen, Betty S. (Jemez Springs, NM); Perry, W. Lee (Jemez Springs, NM)

    2009-09-22T23:59:59.000Z

    Tungsten trioxide hydrate (WO.sub.3.H.sub.2O) was prepared from a precursor solution of ammonium paratungstate in concentrated aqueous hydrochloric acid. The precursor solution was rapidly added to water, resulting in the crash precipitation of a yellow white powder identified as WO.sub.3.H.sub.2O nanosized platelets by x-ray diffraction and scanning electron microscopy. Annealing of the powder at 200.degree. C. provided cubic phase WO.sub.3 nanopowder, and at 400.degree. C. provided WO.sub.3 nanopowder as a mixture of monoclinic and orthorhombic phases.

  1. Process for removal of hydrogen halides or halogens from incinerator gas

    DOE Patents [OSTI]

    Huang, H.S.; Sather, N.F.

    1987-08-21T23:59:59.000Z

    A process for reducing the amount of halogens and halogen acids in high temperature combustion gas and through their removal, the formation of halogenated organics at lower temperatures, with the reduction being carried out electrochemically by contacting the combustion gas with the negative electrode of an electrochemical cell and with the halogen and/or halogen acid being recovered at the positive electrode.

  2. High strength uranium-tungsten alloys

    DOE Patents [OSTI]

    Dunn, Paul S. (Santa Fe, NM); Sheinberg, Haskell (Los Alamos, NM); Hogan, Billy M. (Los Alamos, NM); Lewis, Homer D. (Bayfield, CO); Dickinson, James M. (Los Alamos, NM)

    1991-01-01T23:59:59.000Z

    Alloys of uranium and tungsten and a method for making the alloys. The amount of tungsten present in the alloys is from about 4 wt % to about 35 wt %. Tungsten particles are dispersed throughout the uranium and a small amount of tungsten is dissolved in the uranium.

  3. High strength uranium-tungsten alloy process

    DOE Patents [OSTI]

    Dunn, Paul S. (Santa Fe, NM); Sheinberg, Haskell (Los Alamos, NM); Hogan, Billy M. (Los Alamos, NM); Lewis, Homer D. (Bayfield, CO); Dickinson, James M. (Los Alamos, NM)

    1990-01-01T23:59:59.000Z

    Alloys of uranium and tungsten and a method for making the alloys. The amount of tungsten present in the alloys is from about 4 wt % to about 35 wt %. Tungsten particles are dispersed throughout the uranium and a small amount of tungsten is dissolved in the uranium.

  4. Webinar: Hydrogen Production by Polymer Electrolyte Membrane (PEM) Electrolysis—Spotlight on Giner and Proton

    Broader source: Energy.gov [DOE]

    Video recording of the webinar, Hydrogen Production by Polymer Electrolyte Membrane (PEM) Electrolysis—Spotlight on Giner and Proton, originally presented on May 23, 2011.

  5. Oxidation of hydrogen halides to elemental halogens

    DOE Patents [OSTI]

    Rohrmann, Charles A. (Kennewick, WA); Fullam, Harold T. (Richland, WA)

    1985-01-01T23:59:59.000Z

    A process for oxidizing hydrogen halides having substantially no sulfur impurities by means of a catalytically active molten salt is disclosed. A mixture of the subject hydrogen halide and an oxygen bearing gas is contacted with a molten salt containing an oxidizing catalyst and alkali metal normal sulfates and pyrosulfates to produce an effluent gas stream rich in the elemental halogen and substantially free of sulfur oxide gases.

  6. Direct conversion of halogen-containing wastes to borosilicate glass

    SciTech Connect (OSTI)

    Forsberg, C.W.; Beahm, E.C.; Rudolph, J.C.

    1996-12-09T23:59:59.000Z

    Glass has become a preferred waste form worldwide for radioactive wastes: however, there are limitations. Halogen-containing wastes can not be converted to glass because halogens form poor-quality waste glasses. Furthermore, halides in glass melters often form second phases that create operating problems. A new waste vitrification process, the Glass Material Oxidation and dissolution System (GMODS), removes these limitations by converting halogen-containing wastes into borosilicate glass and a secondary, clean, sodium-halide stream.

  7. Discovery of the Tungsten Isotopes

    E-Print Network [OSTI]

    A. Fritsch; J. Q. Ginepro; M. Heim; A. Schuh; A. Shore; M. Thoennessen

    2009-03-25T23:59:59.000Z

    Thirty-five tungsten isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  8. Discovery of the tungsten isotopes

    SciTech Connect (OSTI)

    Fritsch, A.; Ginepro, J.Q.; Heim, M.; Schuh, A.; Shore, A. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Thoennessen, M. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States)], E-mail: thoennessen@nscl.msu.edu

    2010-05-15T23:59:59.000Z

    Thirty-five tungsten isotopes have been observed so far and the discovery of these isotopes is discussed here. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  9. Discovery of the Tungsten Isotopes

    E-Print Network [OSTI]

    Fritsch, A; Heim, M; Schuh, A; Shore, A; Thoennessen, M

    2009-01-01T23:59:59.000Z

    Thirty-five tungsten isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  10. Process Of Bonding Copper And Tungsten

    DOE Patents [OSTI]

    Slattery, Kevin T. (St. Charles, MO); Driemeyer, Daniel E. (Manchester, MO); Davis, John W. (Ballwin, MO)

    2000-07-18T23:59:59.000Z

    Process for bonding a copper substrate to a tungsten substrate by providing a thin metallic adhesion promoting film bonded to a tungsten substrate and a functionally graded material (FGM) interlayer bonding the thin metallic adhesion promoting film to the copper substrate. The FGM interlayer is formed by sintering a stack of individual copper and tungsten powder blend layers having progressively higher copper content/tungsten content, by volume, ratio values in successive powder blend layers in a lineal direction extending from the tungsten substrate towards the copper substrate. The resulting copper to tungsten joint well accommodates the difference in the coefficient of thermal expansion of the materials.

  11. FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS

    SciTech Connect (OSTI)

    John F. Schabron; Joseph F. Rovani, Jr.; Theresa M. Bomstad

    2003-07-01T23:59:59.000Z

    Western Research Institute (WRI) is continuing work toward the development of new screening methodology and a test kit to measure halogenated volatile organic compounds (VOCs) in the field. Heated diode and corona discharge sensors are commonly used to detect leaks of refrigerants from air conditioners, freezers, and refrigerators. They are both selective to the presence of halogens. In prior work, the devices were tested for response to carbon tetrachloride, heptane, toluene, and water vapors. In the current work, sensor response was evaluated with sixteen halogenated VOCs relative to carbon tetrachloride. The results show that the response of the various chlorinated VOCs is within an order of magnitude of the response to carbon tetrachloride for each of the sensors. Thus, for field screening a single response factor can be used. Both types of leak detectors are being further modified to provide an on-board LCD signal readout, which is related to VOC concentration. The units will be fully portable and will operate with 115-V line or battery power. Signal background, noise level, and response data on the Bacharach heated diode detector and the TIF corona discharge detector show that when the response curves are plotted against the log of concentration, the plot is linear to the upper limit for the particular unit, with some curvature at lower levels. When response is plotted directly against concentration, the response is linear at the low end and is curved at the high end. The dynamic ranges for carbon tetrachloride of the two devices from the lower detection limit (S/N=2) to signal saturation are 4-850 vapor parts per million (vppm) for the corona discharge unit and 0.01-70 vppm for the heated diode unit. Additional circuit modifications are being made to lower the detection limit and increase the dynamic response range of the corona discharge unit. The results indicate that both devices show potential utility for future analytical method development work toward the goal of developing a portable test kit for screening halogenated VOCs in the field.

  12. Tungsten diffusion in silicon

    SciTech Connect (OSTI)

    De Luca, A.; Texier, M.; Burle, N.; Oison, V.; Pichaud, B. [Aix-Marseille Université, IM2NP UMR 7334, Faculté des Sciences et Techniques, Campus de Saint-Jérôme, Avenue Escadrille Normandie Niemen - Case 142, F-13397 Marseille Cedex (France); Portavoce, A., E-mail: alain.portavoce@im2np.fr [CNRS, IM2NP UMR 7334, Faculté des Sciences et Techniques, Campus de Saint-Jérôme, Avenue Escadrille Normandie Niemen - Case 142, F-13397 Marseille Cedex (France); Grosjean, C. [STMicroelectronics, Rousset (France)

    2014-01-07T23:59:59.000Z

    Two doses (10{sup 13} and 10{sup 15}?cm{sup ?2}) of tungsten (W) atoms were implanted in different Si(001) wafers in order to study W diffusion in Si. The samples were annealed or oxidized at temperatures between 776 and 960?°C. The diffusion profiles were measured by secondary ion mass spectrometry, and defect formation was studied by transmission electron microscopy and atom probe tomography. W is shown to reduce Si recrystallization after implantation and to exhibit, in the temperature range investigated, a solubility limit close to 0.15%–0.2%, which is higher than the solubility limit of usual metallic impurities in Si. W diffusion exhibits unusual linear diffusion profiles with a maximum concentration always located at the Si surface, slower kinetics than other metals in Si, and promotes vacancy accumulation close to the Si surface, with the formation of hollow cavities in the case of the higher W dose. In addition, Si self-interstitial injection during oxidation is shown to promote W-Si clustering. Taking into account these observations, a diffusion model based on the simultaneous diffusion of interstitial W atoms and W-Si atomic pairs is proposed since usual models used to model diffusion of metallic impurities and dopants in Si cannot reproduce experimental observations.

  13. Workers' Spotlight Newsletter - Issue 1 | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof Energy 2, 2015Visiting Strong,Women @ Energy:Terri Workers' Spotlight Newsletter -

  14. Workers' Spotlight Newsletter - Issue 10 | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof Energy 2, 2015Visiting Strong,Women @ Energy:Terri Workers' Spotlight Newsletter -0

  15. Workers' Spotlight Newsletter - Issue 11 | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof Energy 2, 2015Visiting Strong,Women @ Energy:Terri Workers' Spotlight Newsletter

  16. Workers' Spotlight Newsletter - Issue 12 | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof Energy 2, 2015Visiting Strong,Women @ Energy:Terri Workers' Spotlight Newsletter2

  17. Workers' Spotlight Newsletter - Issue 13 | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof Energy 2, 2015Visiting Strong,Women @ Energy:Terri Workers' Spotlight

  18. Workers' Spotlight Newsletter - Issue 2 | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof Energy 2, 2015Visiting Strong,Women @ Energy:Terri Workers' Spotlight2 Workers'

  19. Workers' Spotlight Newsletter - Issue 3 | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof Energy 2, 2015Visiting Strong,Women @ Energy:Terri Workers' Spotlight2 Workers'3

  20. Workers' Spotlight Newsletter - Issue 4 | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof Energy 2, 2015Visiting Strong,Women @ Energy:Terri Workers' Spotlight2 Workers'34

  1. Workers' Spotlight Newsletter - Issue 5 | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof Energy 2, 2015Visiting Strong,Women @ Energy:Terri Workers' Spotlight2 Workers'345

  2. Workers' Spotlight Newsletter - Issue 6 | Department of Energy

    Energy Savers [EERE]

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  3. Workers' Spotlight Newsletter - Issue 7 | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof Energy 2, 2015Visiting Strong,Women @ Energy:Terri Workers' Spotlight2

  4. Workers' Spotlight Newsletter - Issue 8 | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof Energy 2, 2015Visiting Strong,Women @ Energy:Terri Workers' Spotlight28 Workers'

  5. Workers' Spotlight Newsletter - Issue 9 | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnual Siteof Energy 2, 2015Visiting Strong,Women @ Energy:Terri Workers' Spotlight28

  6. Method of synthesizing tungsten nanoparticles

    SciTech Connect (OSTI)

    Thoma, Steven G; Anderson, Travis M

    2013-02-12T23:59:59.000Z

    A method to synthesize tungsten nanoparticles has been developed that enables synthesis of nanometer-scale, monodisperse particles that can be stabilized only by tetrahydrofuran. The method can be used at room temperature, is scalable, and the product concentrated by standard means. Since no additives or stabilizing surfactants are required, this method is particularly well suited for producing tungsten nanoparticles for dispersion in polymers. If complete dispersion is achieved due to the size of the nanoparticles, then the optical properties of the polymer can be largely maintained.

  7. Metal halogen battery construction with improved technique for producing halogen hydrate

    DOE Patents [OSTI]

    Fong, Walter L. (Royal Oak, MI); Catherino, Henry A. (Rochester, MI); Kotch, Richard J. (Mt. Clemens, MI)

    1983-01-01T23:59:59.000Z

    An improved electrical energy storage system comprising, at least one cell having a positive electrode and a negative electrode separated by aqueous electrolyte, a store means wherein halogen hydrate is formed and stored as part of an aqueous material having a liquid level near the upper part of the store, means for circulating electrolyte through the cell, conduit means for transmitting halogen gas formed in the cell to a hydrate forming apparatus associated with the store, said hydrate forming apparatus including, a pump to which there is introduced quantities of the halogen gas and chilled water, said pump being located in the store and an outlet conduit leading from the pump and being substantially straight and generally vertically disposed and having an exit discharge into the gas space above the liquid level in the store, and wherein said hydrate forming apparatus is highly efficient and very resistant to plugging or jamming. The disclosure also relates to an improved method for producing chlorine hydrate in zinc chlorine batteries.

  8. Process Of Bonding Copper And Tungsten

    DOE Patents [OSTI]

    Slattery, Kevin T. (St. Charles, MO); Driemeyer, Daniel E. (Manchester, MO)

    1999-11-23T23:59:59.000Z

    Process for bonding a copper substrate to a tungsten substrate by providing a thin metallic adhesion promoting film bonded to a tungsten substrate and a functionally graded material (FGM) interlayer bonding the thin metallic adhesion promoting film to the copper substrate. The FGM interlayer is formed by thermal plasma spraying mixtures of copper powder and tungsten powder in a varied blending ratio such that the blending ratio of the copper powder and the tungsten powder that is fed to a plasma torch is intermittently adjusted to provide progressively higher copper content/tungsten content, by volume, ratio values in the interlayer in a lineal direction extending from the tungsten substrate towards the copper substrate. The resulting copper to tungsten joint well accommodates the difference in the coefficient of thermal expansion of the materials.

  9. Accepted Manuscript Making Tungsten Work

    E-Print Network [OSTI]

    Raffray, A. René

    Thermonuclear Experimental Reactor Organization, Cadarache, FRANCE 3 Plasma Science and Fusion Center at MIT International Thermonuclear Experimental Reactor Organization, Cadarache, FRANCE 3 Plasma Science and Fusion Thermonuclear Experimental Reactor). Tungsten (W) is the plasma-facing material of choice in several design

  10. Photochemical reductive elimination of halogen from transition metal complexes

    E-Print Network [OSTI]

    Cook, Timothy R. (Timothy Raymond), 1982-

    2010-01-01T23:59:59.000Z

    This thesis is focused on the synthesis and study of transition metal complexes that undergo halogen elimination when irradiated with UV and visible light. This chemistry is relevant for solar energy storage schemes in ...

  11. Halogenated naphthyl methoxy piperidines for mapping serotonin transporter sites

    DOE Patents [OSTI]

    Goodman, Mark M. (Atlanta, GA); Faraj, Bahjat (Lithonia, GA)

    1999-01-01T23:59:59.000Z

    Halogenated naphthyl methoxy piperidines having a strong affinity for the serotonin transporter are disclosed. Those compounds can be labeled with positron-emitting and/or gamma emitting halogen isotopes by a late step synthesis that maximizes the useable lifeterm of the label. The labeled compounds are useful for localizing serotonin transporter sites by positron emission tomography and/or single photon emission computed tomography.

  12. Halogenated naphthyl methoxy piperidines for mapping serotonin transporter sites

    DOE Patents [OSTI]

    Goodman, M.M.; Faraj, B.

    1999-07-06T23:59:59.000Z

    Halogenated naphthyl methoxy piperidines having a strong affinity for the serotonin transporter are disclosed. Those compounds can be labeled with positron-emitting and/or gamma emitting halogen isotopes by a late step synthesis that maximizes the useable lifeterm of the label. The labeled compounds are useful for localizing serotonin transporter sites by positron emission tomography and/or single photon emission computed tomography.

  13. IUFRO Spotlight #19/ April 2014 / IUFRO World Congress `Citizen science': A way to fight invasive species?

    E-Print Network [OSTI]

    California at Berkeley, University of

    IUFRO Spotlight #19/ April 2014 / IUFRO World Congress `Citizen science': A way to fight invasive of a tree can mean to different social groups. The organizers see this "citizen science" (one definition

  14. ______________________~~-www.lejacq.com ID:8430 SPOTLIGHT ON HEART FAILURE TRANSLATIONAL RESEARCH

    E-Print Network [OSTI]

    Hammock, Bruce D.

    ______________________~~-www.lejacq.com ID:8430 SPOTLIGHT ON HEART FAILURE TRANSLATIONAL RESEARCH of atherosclerotic plaque as well as infarct size associated with ischemic heart injury.2 An unexpected finding, how

  15. Treatment of halogen-containing waste and other waste materials

    DOE Patents [OSTI]

    Forsberg, C.W.; Beahm, E.C.; Parker, G.W.

    1997-03-18T23:59:59.000Z

    A process is described for treating a halogen-containing waste material. The process provides a bath of molten glass containing a sacrificial metal oxide capable of reacting with a halogen in the waste material. The sacrificial metal oxide is present in the molten glass in at least a stoichiometric amount with respect to the halogen in the waste material. The waste material is introduced into the bath of molten glass to cause a reaction between the halogen in the waste material and the sacrificial metal oxide to yield a metal halide. The metal halide is a gas at the temperature of the molten glass. The gaseous metal halide is separated from the molten glass and contacted with an aqueous scrubber solution of an alkali metal hydroxide to yield a metal hydroxide or metal oxide-containing precipitate and a soluble alkali metal halide. The precipitate is then separated from the aqueous scrubber solution. The molten glass containing the treated waste material is removed from the bath as a waste glass. The process of the invention can be used to treat all types of waste material including radioactive wastes. The process is particularly suited for separating halogens from halogen-containing wastes. 3 figs.

  16. Treatment of halogen-containing waste and other waste materials

    DOE Patents [OSTI]

    Forsberg, Charles W. (Oak Ridge, TN); Beahm, Edward C. (Oak Ridge, TN); Parker, George W. (Concord, TN)

    1997-01-01T23:59:59.000Z

    A process for treating a halogen-containing waste material. The process provides a bath of molten glass containing a sacrificial metal oxide capable of reacting with a halogen in the waste material. The sacrificial metal oxide is present in the molten glass in at least a stoichiometric amount with respect to the halogen in the waste material. The waste material is introduced into the bath of molten glass to cause a reaction between the halogen in the waste material and the sacrificial metal oxide to yield a metal halide. The metal halide is a gas at the temperature of the molten glass. The gaseous metal halide is separated from the molten glass and contacted with an aqueous scrubber solution of an alkali metal hydroxide to yield a metal hydroxide or metal oxide-containing precipitate and a soluble alkali metal halide. The precipitate is then separated from the aqueous scrubber solution. The molten glass containing the treated waste material is removed from the bath as a waste glass. The process of the invention can be used to treat all types of waste material including radioactive wastes. The process is particularly suited for separating halogens from halogen-containing wastes.

  17. Metal halogen battery system with multiple outlet nozzle for hydrate

    DOE Patents [OSTI]

    Bjorkman, Jr., Harry K. (Birmingham, MI)

    1983-06-21T23:59:59.000Z

    A metal halogen battery system, including at least one cell having a positive electrode and a negative electrode contacted by aqueous electrolyte containing the material of said metal and halogen, store means whereby halogen hydrate is formed and stored as part of an aqueous material, means for circulating electrolyte through the cell and to the store means, and conduit means for transmitting halogen gas formed in the cell to a hydrate former whereby the hydrate is formed in association with the store means, said store means being constructed in the form of a container which includes a filter means, said filter means being inoperative to separate the hydrate formed from the electrolyte, said system having, a hydrate former pump means associated with the store means and being operative to intermix halogen gas with aqueous electrolyte to form halogen hydrate, said hydrate former means including, multiple outlet nozzle means connected with the outlet side of said pump means and being operative to minimize plugging, said nozzle means being comprised of at least one divider means which is generally perpendicular to the rotational axes of gears within the pump means, said divider means acting to divide the flow from the pump means into multiple outlet flow paths.

  18. Diffusion of tungsten clusters on tungsten (110) surface

    SciTech Connect (OSTI)

    Chen, Dong; Hu, Wangyu; Yang, Jianyu; Deng, Huiqiu; Sun, Lixian; Gao, Fei

    2009-04-01T23:59:59.000Z

    Using molecular dynamics simulation and modified analytic embedded-atom method, we have investigated the self-diffusion of clusters on a tungsten (110) surface. As compared to the linear-chain configuration, the close-packed islands for tungsten clusters containing more than nine adatoms have been predicted to be more stable with the relatively lower binding energies. The migration energies show an interesting and oscillating behavior with increasing cluster size. The tetramer, hexamer and octamer have obviously higher migration energies than the others. The different atomic configurations and diffusion mechanisms have been determined during the diffusion processes. It is clear that the dimer-shearing mechanism occurs inside the hexamer, while it occurs at the periphery of heptamer. The successive hopping mechanism of individual atom is of critical importance in the migration of the clusters containing five or fewer adatoms. In addition, the diffusion of a cluster with nine adatoms is achieved through the changes of the cluster shape.

  19. A Well-Defined, Silica-Supported Tungsten Imido Alkylidene Olefin Metathesis Catalyst

    E-Print Network [OSTI]

    2006-01-01T23:59:59.000Z

    deactivation. Keywords. Tungsten Imido Alkylidene complex.monosiloxy alkylidene tungsten surface complex syn-2, [(_

  20. Gamma Spectrum from Neutron Capture on Tungsten Isotopes

    E-Print Network [OSTI]

    Hurst, Aaron

    2011-01-01T23:59:59.000Z

    FROM NEUTRON CAPTURE ON TUNGSTEN ISOTOPES A. M. HURST ?1,2 ,capture on the stable tungsten isotopes is presented, withknown decay schemes of the tungsten isotopes from neutron

  1. Factors controlling tungsten concentrations in ground water, Carson Desert, Nevada

    E-Print Network [OSTI]

    Factors controlling tungsten concentrations in ground water, Carson Desert, Nevada Ralph L. Seiler sources. Tungsten concentrations in 100 ground water samples from all aquifers used as drinking water indicates that W exhibits Tungsten con- centrations are strongly and positively correlated

  2. Growth of Ordered Ultrathin Tungsten Oxide Films on Pt(111)....

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

    Growth of Ordered Ultrathin Tungsten Oxide Films on Pt(111). Growth of Ordered Ultrathin Tungsten Oxide Films on Pt(111). Abstract: Ordered tungsten oxide ultra-thin films were...

  3. Effects of Tungsten Oxide Addition on the Electrochemical Performance...

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

    Tungsten Oxide Addition on the Electrochemical Performance of Nanoscale Tantalum Oxide-Based Electrocatalysts for Effects of Tungsten Oxide Addition on the Electrochemical...

  4. Halogenated 1'-methyl-1,2'-bipyrroles (MBPs) in the Norwestern Atlantic

    E-Print Network [OSTI]

    Pangallo, Kristin C

    2009-01-01T23:59:59.000Z

    Halogenated 1'-methyl-1,2'-bipyrroles (MBPs) are a distinctive class of marine organic compounds. They are naturally produced, they have a unique carbon structure, they are highly halogenated, and they bioaccumulate in ...

  5. Solid-State Halogen Atom Source for Chemical Dynamics and Etching...

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

    Halogen Atom Source for Chemical Dynamics and Etching. Solid-State Halogen Atom Source for Chemical Dynamics and Etching. Abstract: We describe a solid state Br atom source for...

  6. E-Print Network 3.0 - agents anesthesiques halogenes Sample Search...

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

    Chemistry 17 Incompatible Chemicals -Partial list Chemical Incompatibilities Summary: , carbon tetrachloride or other chlorinated hydrocarbons, carbon dioxide, halogens Ammonia...

  7. Symmetric and asymmetric halogen-containing metallocarboranylporphyrins and uses thereof

    DOE Patents [OSTI]

    Miura, Michiko; Wu, Haitao

    2013-05-21T23:59:59.000Z

    The present invention is directed to low toxicity boronated compounds and methods for their use in the treatment, visualization, and diagnosis of tumors. More specifically, the present invention is directed to low toxicity halogenated, carborane-containing 5,10,15,20-tetraphenylporphyrin compounds and methods for their use particularly in boron neutron capture therapy (BNCT) and photodynamic therapy (PDT) for the treatment of tumors of the brain, head and neck, and surrounding tissue. The invention is also directed to using these halogenated, carborane-containing tetraphenylporphyrin compounds in methods of tumor imaging and/or diagnosis such as MRI, SPECT, or PET.

  8. Process for oxidation of hydrogen halides to elemental halogens

    DOE Patents [OSTI]

    Lyke, Stephen E. (Middleton, WI)

    1992-01-01T23:59:59.000Z

    An improved process for generating an elemental halogen selected from chlorine, bromine or iodine, from a corresponding hydrogen halide by absorbing a molten salt mixture, which includes sulfur, alkali metals and oxygen with a sulfur to metal molar ratio between 0.9 and 1.1 and includes a dissolved oxygen compound capable of reacting with hydrogen halide to produce elemental halogen, into a porous, relatively inert substrate to produce a substrate-supported salt mixture. Thereafter, the substrate-supported salt mixture is contacted (stage 1) with a hydrogen halide while maintaining the substrate-supported salt mixture during the contacting at an elevated temperature sufficient to sustain a reaction between the oxygen compound and the hydrogen halide to produce a gaseous elemental halogen product. This is followed by purging the substrate-supported salt mixture with steam (stage 2) thereby recovering any unreacted hydrogen halide and additional elemental halogen for recycle to stage 1. The dissolved oxygen compound is regenerated in a high temperature (stage 3) and an optical intermediate temperature stage (stage 4) by contacting the substrate-supported salt mixture with a gas containing oxygen whereby the dissolved oxygen compound in the substrate-supported salt mixture is regenerated by being oxidized to a higher valence state.

  9. Method for selective dehalogenation of halogenated polyaromatic compounds

    DOE Patents [OSTI]

    Farcasiu, Malvina (Pittsburgh, PA); Petrosius, Steven C. (Library, PA)

    1994-01-01T23:59:59.000Z

    A method for dehalogenating halogenated polyaromatic compounds is provided wherein the polyaromatic compounds are mixed with a hydrogen donor solvent and a carbon catalyst in predetermined proportions, the mixture is maintained at a predetermined pressure, and the mixture is heated to a predetermined temperature and for a predetermined time.

  10. High strength and density tungsten-uranium alloys

    DOE Patents [OSTI]

    Sheinberg, Haskell (Los Alamos, NM)

    1993-01-01T23:59:59.000Z

    Alloys of tungsten and uranium and a method for making the alloys. The amount of tungsten present in the alloys is from about 55 vol % to about 85 vol %. A porous preform is made by sintering consolidated tungsten powder. The preform is impregnated with molten uranium such that (1) uranium fills the pores of the preform to form uranium in a tungsten matrix or (2) uranium dissolves portions of the preform to form a continuous uranium phase containing tungsten particles.

  11. Physical properties of erbium implanted tungsten oxide films deposited by reactive dual magnetron sputtering

    E-Print Network [OSTI]

    Mohamed, Sodky H.; Anders, Andre

    2006-01-01T23:59:59.000Z

    of erbium implanted tungsten oxide films deposited byDual magnetron sputtering; tungsten oxide films; Er ionoptical waveguides [3,5]. Tungsten oxide (WO 3 ) thin films

  12. FINAL FOCUS ION BEAM INTENSITY FROM TUNGSTEN FOIL CALORIMETER AND SCINTILLATOR IN NDCX-I

    E-Print Network [OSTI]

    Lidia, S.M.

    2010-01-01T23:59:59.000Z

    FOCUS ION BEAM INTENSITY FROM TUNGSTEN FOIL CALORIMETER ANDtemperature rise in the tungsten foil. A cross-calibrationis obtained with a 3µm thick tungsten foil calorimeter and

  13. Report to the New Jersey State Board of Agriculture Spotlight on Rutgers NJAES EcoComplex

    E-Print Network [OSTI]

    Goodman, Robert M.

    Report to the New Jersey State Board of Agriculture April 2009 Spotlight on Rutgers NJAES Eco and economic growth," notes David Specca, assistant director for bioenergy technologies and controlled-environment agriculture at the EcoComplex. "By offering services and resources to entrepreneurs that are not available

  14. A SPOTLIGHT SEARCH METHOD FOR MULTI-CRITERIA OPTIMIZATION PROBLEMS Jung-Ho Lewe

    E-Print Network [OSTI]

    Coello, Carlos A. Coello

    -criteria optimization (MCO) prob- lem, in general, is a difficult practice. Numerous meth- ods have been proposed and applied to various applica- tions over the past few decades. This paper introduces a new MCO method suitable for continuous, nonlinear MCO problems. The concept of the proposed method, a spotlight search

  15. Chem 115Lithium-Halogen ExchangeMyers RLi + R'X RX + R'Li

    E-Print Network [OSTI]

    Chem 115Lithium-Halogen ExchangeMyers RLi + R'X RX + R'Li Lithium-halogen exchange reactions are essentially inert. 2 t-BuLi t-BuI + RLi t-BuLi isobutene + isobutane + LiI Lithium-halogen exchange reactions, and lithium iodide. H OEtBr H H OEtLi H1.1 eq n-BuLi Et2O, !80 °C Lau, K. S.; Schlosser, M. J. Org. Chem. 1978

  16. TUNGSTEN--2001 80.1 By Kim B. Shedd

    E-Print Network [OSTI]

    , electrical, heating, and welding applications. Tungsten is also used to make heavy-metal alloys for armaments- temperature lubricants. U.S. apparent consumption of all tungsten materials in 2001 remained approximately

  17. TUNGSTEN--2002 80.1 By Kim B. Shedd

    E-Print Network [OSTI]

    , electrical, heating, and welding applications. Tungsten is also used to make heavy-metal alloys for armaments, high-temperature lubricants, and semiconductors. U.S. apparent consumption of all tungsten materials

  18. Growth of tungsten oxide on carbon nanowalls templates

    SciTech Connect (OSTI)

    Wang, Hua, E-mail: wanghua@dlou.edu.cn [Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China); College of Fisheries and Life Science, Dalian Ocean University, Dalian 116023 (China); Su, Yan [Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China); Chen, Shuo, E-mail: shuochen@dlut.edu.cn [Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China); Quan, Xie [Faculty of Chemical, Environmental and Biological Science and Technology, Dalian University of Technology, Dalian 116024 (China)

    2013-03-15T23:59:59.000Z

    Highlights: ? Tungsten oxide deposited on carbon nanowalls by hot filament chemical vapor deposition technique. ? This composite has two-dimensional uniform morphology with a crystalline structure of monoclinic tungsten trioxide. ? Surface photoelectric voltage measurements show that this product has photoresponse properties. - Abstract: In the present work we present a simple approach for coupling tungsten oxide with carbon nanowalls. The two-dimensional carbon nanowalls with open boundaries were grown using plasma enhanced hot filament chemical vapor deposition, and the subsequent tungsten oxide growth was performed in the same equipment by direct heating of a tungsten filament. The tungsten oxide coating is found to have uniform morphology with a crystalline structure of monoclinic tungsten trioxide. Surface photoelectric voltage measurements show that this product has photoresponse properties. The method of synthesis described here provides an operable route to the production of two-dimensional tungsten oxide nanocomposites.

  19. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: In 1998, little if any tungsten concentrate was produced from U.S. mines.

    E-Print Network [OSTI]

    184 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: In 1998, little if any tungsten concentrate was produced from U.S. mines. Approximately 10 companies in the United States processed tungsten concentrates, ammonium paratungstate, tungsten oxide, and

  20. Element 74, the Wolfram Versus Tungsten Controversy

    SciTech Connect (OSTI)

    Holden,N.E.

    2008-08-11T23:59:59.000Z

    Two and a quarter centuries ago, a heavy mineral ore was found which was thought to contain a new chemical element called heavy stone (or tungsten in Swedish). A few years later, the metal was separated from its oxide and the new element (Z=74) was called wolfram. Over the years since that time, both the names wolfram and tungsten were attached to this element in various countries. Sixty years ago, IUPAC chose wolfram as the official name for the element. A few years later, under pressure from the press in the USA, the alternative name tungsten was also allowed by IUPAC. Now the original, official name 'wolfram' has been deleted by IUPAC as one of the two alternate names for the element. The history of this controversy is described here.

  1. TUNGSTEN--2000 81.1 By Kim B. Shedd

    E-Print Network [OSTI]

    TUNGSTEN--2000 81.1 TUNGSTEN By Kim B. Shedd Domestic survey data and tables were prepared by Jason T. Collins, statistical assistant, and the world production table was prepared by Glenn J. Wallace, international data coordinator. Tungsten is a whitish-gray metal with many unique properties and a wide variety

  2. Spotlight: Two Los Alamos scientists honored with E.O. Lawrence Awards

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over Our Instagram Secretary900 Special Report:Spotlight: Bryant Roybal

  3. Gas tungsten arc welder with electrode grinder

    DOE Patents [OSTI]

    Christiansen, David W. (Kennewick, WA); Brown, William F. (West Richland, WA)

    1984-01-01T23:59:59.000Z

    A welder for automated closure of fuel pins by a gas tungsten arc process in which a rotating length of cladding is positioned adjacent a welding electrode in a sealed enclosure. An independently movable axial grinder is provided in the enclosure for refurbishing the used electrode between welds.

  4. Catalytic ionic hydrogenation of ketones using tungsten or molybdenum organometallic species

    DOE Patents [OSTI]

    Voges, Mark (Leverkusen, DE); Bullock, R. Morris (Wading River, NY)

    2000-01-01T23:59:59.000Z

    The present invention is a process for the catalytic hydrogenation of ketones and aldehydes to alcohols at low temperatures and pressures using organometallic molybdenum and tungsten complexes. The functional group is selected from groups represented by the formulas R(C.dbd.O)R' and R(C.dbd.O)H, wherein R and R' are selected from hydrogen or any alkyl or aryl group. The active catalyst for the process has the form: [CpM(CO).sub.2 (PR*.sub.3) L].sup.+ A.sup.-, where Cp=.eta..sup.5 -R.sup..tangle-solidup..sub.m C.sub.5 H.sub.5-m and R.sup..tangle-solidup. represents an alkyl group or a halogen (F, Cl, Br, I) or R.sup..tangle-solidup. =OR' (where R'=H, an alkyl group or an aryl group) or R.sup..tangle-solidup. =CO.sub.2 R' (where R'=H, an alkyl group or an aryl group) and m=0 to 5; M represents a molybdenum atom or a tungsten atom; R*.sub.3 represents three hydrocarbon groups selected from a cyclohexyl group (C.sub.6 H.sub.11), a methyl group (CH.sub.3), and a phenyl group (C.sub.6 H.sub.5) and all three R* groups can be the same or different or two of the three groups can be the same; L represents a ligand; and A.sup.- represents an anion. In another embodiment, one, two or three of the R* groups can be an OR*.

  5. Tungsten Divertor Erosion in all Metal Devices: Lessons from the ITER-Like Wall of JET and the All Tungsten ASDEX Upgrade

    E-Print Network [OSTI]

    Tungsten Divertor Erosion in all Metal Devices: Lessons from the ITER-Like Wall of JET and the All Tungsten ASDEX Upgrade

  6. Controlled nanostructuration of polycrystalline tungsten thin films

    SciTech Connect (OSTI)

    Girault, B. [Institut P' (UPR 3346 CNRS), Universite de Poitiers, ENSMA, Bd Pierre et Marie Curie, 86962 Futuroscope Cedex (France); Institut de Recherche en Genie Civil et Mecanique (UMR CNRS 6183), LUNAM Universite, Universite de Nantes, Centrale Nantes, CRTT, 37 Bd de l'Universite, BP 406, 44602 Saint-Nazaire Cedex (France); Eyidi, D.; Goudeau, P.; Guerin, P.; Bourhis, E. Le; Renault, P.-O. [Institut P' (UPR 3346 CNRS), Universite de Poitiers, ENSMA, Bd Pierre et Marie Curie, 86962 Futuroscope Cedex (France); Sauvage, T. [CEMHTI/CNRS (UPR 3079 CNRS), Universite d'Orleans, 3A rue de la Ferollerie, 45071 Orleans Cedex 2 (France)

    2013-05-07T23:59:59.000Z

    Nanostructured tungsten thin films have been obtained by ion beam sputtering technique stopping periodically the growing. The total thickness was maintained constant while nanostructure control was obtained using different stopping periods in order to induce film stratification. The effect of tungsten sublayers' thicknesses on film composition, residual stresses, and crystalline texture evolution has been established. Our study reveals that tungsten crystallizes in both stable {alpha}- and metastable {beta}-phases and that volume proportions evolve with deposited sublayers' thicknesses. {alpha}-W phase shows original fiber texture development with two major preferential crystallographic orientations, namely, {alpha}-W<110> and unexpectedly {alpha}-W<111> texture components. The partial pressure of oxygen and presence of carbon have been identified as critical parameters for the growth of metastable {beta}-W phase. Moreover, the texture development of {alpha}-W phase with two texture components is shown to be the result of a competition between crystallographic planes energy minimization and crystallographic orientation channeling effect maximization. Controlled grain size can be achieved for the {alpha}-W phase structure over 3 nm stratification step. Below, the {beta}-W phase structure becomes predominant.

  7. Tungsten-dependent formaldehyde ferredoxin oxidoreductase: Reaction mechanism from quantum chemical calculations

    E-Print Network [OSTI]

    Liao, Rongzhen

    Tungsten-dependent formaldehyde ferredoxin oxidoreductase: Reaction mechanism from quantum chemical theory Enzyme catalysis Formaldehyde ferredoxin oxidoreductase from Pyrococcus furiosus is a tungsten the formaldehyde substrate binds directly to the tungsten ion. WVI =O then performs a nucleophilic attack

  8. Molybdenum and Tungsten Monoalkoxide Pyrrolide (MAP) Alkylidene Complexes That Contain a 2,6-Dimesitylphenylimido

    E-Print Network [OSTI]

    Müller, Peter

    Molybdenum and Tungsten Monoalkoxide Pyrrolide (MAP) Alkylidene Complexes That Contain a 2 ABSTRACT: Molybdenum and tungsten bispyrrolide alkyli- dene complexes that contain a 2 those that contain 2,5-dimethylpyrro- lide are pyridine free. Molybdenum and tungsten MAP 2

  9. Investigation of coronal plasma dynamics in tungsten and carbon X-pinches

    E-Print Network [OSTI]

    Madden, Robert Edward

    2008-01-01T23:59:59.000Z

    Coronal Plasma Dynamics in Tungsten and Carbon X-pinches ACoronal Plasma Dynamics in Tungsten and Carbon X-pinches byformation in 2- and 4-wire tungsten x-pinches using an 80

  10. CRITICAL FIELD FOR SUPERCONDUCTIVITY AND LOW-TEMPERATURE NORMAL-STATE HEAT CAPACITY OF TUNGSTEN

    E-Print Network [OSTI]

    Triplett, B.B.

    2008-01-01T23:59:59.000Z

    NORMAL-STATE HEAT CAPACITY OF TUNGSTEN B. B. Triplett, N. E.State Heat Capacity of Tungsten* B. n. Triplett,t N. E.I. ;\\feasurement Properties of tungsten sa~ples. ~feasured

  11. THE As-QUENCHED MICROSTRUCTURE AND TEMPERING BEHAVIOR OF RAPIDLY SOLIDIFIED TUNGSTEN STEELS

    E-Print Network [OSTI]

    Rayment, J.J.

    2014-01-01T23:59:59.000Z

    of six ternary iron-tungsten-carbon alloys and commercialFeWCS-6 (20 and 23wt% tungsten) only the cellular micro-microstructure of the higher tungsten alloys. Selected area

  12. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: In 1997, little if any tungsten concentrate was produced from U.S. mines.

    E-Print Network [OSTI]

    182 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production in a significant decrease in mine production. The amount of tungsten concentrates remaining in stockpiles in China for the tungsten industry. Once the stockpiles are depleted, world mine production will have to increase to meet

  13. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: Limited shipments of tungsten concentrates were made from a California mine in

    E-Print Network [OSTI]

    178 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and primary products, wrought and unwrought tungsten, and waste and scrap: China, 43%; Germany, 11%; Canada,630 1,450 Events, Trends, and Issues: World tungsten supply was dominated by Chinese production

  14. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: A tungsten mine in California produced concentrates in 2012. Approximately eight

    E-Print Network [OSTI]

    176 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and concentrates, intermediate and primary products, wrought and unwrought tungsten, and waste and scrap: China, 45,200 3,630 1,610 Events, Trends, and Issues: World tungsten supply was dominated by Chinese production

  15. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: One mine in California produced tungsten concentrates in 2010. Approximately

    E-Print Network [OSTI]

    176 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production. Import Sources (2006­09): Tungsten contained in ores and concentrates, intermediate and primary products, Trends, and Issues: World tungsten supply is dominated by Chinese production and exports. China

  16. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: A mine in California produced tungsten concentrates in 2009. Approximately eight

    E-Print Network [OSTI]

    176 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production. Import Sources (2005-08): Tungsten contained in ores and concentrates, intermediate and primary products, and Issues: World tungsten supply was dominated by Chinese production and exports. China's Government limited

  17. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: A mine in California restarted operations and made its first shipment of tungsten

    E-Print Network [OSTI]

    182 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and primary products, wrought and unwrought tungsten, and waste and scrap: China, 43%; Canada, 16%; Germany, 9 by Chinese production and exports. China's Government restricted the amounts of tungsten that could

  18. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last recorded production of tungsten concentrates in the United States was in

    E-Print Network [OSTI]

    182 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last recorded production of tungsten concentrates in the United States was in 1994 of ores and concentrates, intermediate and primary products, wrought and unwrought tungsten, and waste

  19. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last recorded production of tungsten concentrates in the United States was in

    E-Print Network [OSTI]

    178 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last recorded production of tungsten concentrates in the United States was in 1994. In 2000, intermediate and primary products, wrought and unwrought tungsten, and waste and scrap: China, 39%; Russia, 21

  20. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: A tungsten mine in California produced concentrates in 2013. Approximately eight

    E-Print Network [OSTI]

    174 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and concentrates, intermediate and primary products, wrought and unwrought tungsten, and waste and scrap: China, 45,100 2,300 2,240 Events, Trends, and Issues: World tungsten supply was dominated by Chinese production

  1. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: One mine in California produced tungsten concentrates in 2011. Approximately

    E-Print Network [OSTI]

    176 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production (2007­10): Tungsten contained in ores and concentrates, intermediate and primary products, wrought: World tungsten supply is dominated by Chinese production and exports. China's Government regulates its

  2. Tungsten Cluster Migration on Nanoparticles: Minimum Energy Pathway...

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

    Pathway and Migration Mechanism. Tungsten Cluster Migration on Nanoparticles: Minimum Energy Pathway and Migration Mechanism. Abstract: Transition state searches have been...

  3. alkaline tungsten matrix: Topics by E-print Network

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

    Thermonuclear Experimental Reactor Organization, Cadarache, FRANCE 3 Plasma Science and Fusion Thermonuclear Experimental Reactor). Tungsten (W) is the plasma-facing material of...

  4. anthocyanins facilitate tungsten: Topics by E-print Network

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

    Thermonuclear Experimental Reactor Organization, Cadarache, FRANCE 3 Plasma Science and Fusion Thermonuclear Experimental Reactor). Tungsten (W) is the plasma-facing material of...

  5. Catalytic, Asymmetric r-Halogenation Harald Wack, Andrew E. Taggi, Ahmed M. Hafez,

    E-Print Network [OSTI]

    Lectka, Thomas

    reported "relay" deprotonation strategy,5 in which protons are shuttled from the chiral amine catalyst Phenylacetyl chloride 1a was used as a test substrate to screen the various halogenating agents using 10 mol

  6. Synthesis of Molybdenum and Tungsten Alkylidene Complexes That Contain Sterically Demanding Arenethiolate Ligands

    E-Print Network [OSTI]

    Müller, Peter

    Synthesis of Molybdenum and Tungsten Alkylidene Complexes That Contain Sterically Demanding,4 we decided to explore some arylthiolate analogues of terphenoxide molybde- num imido and tungsten

  7. Tungsten silicide and tungsten polycide anisotropic dry etch process for highly controlled dimensions and profiles

    E-Print Network [OSTI]

    Bashir, Rashid

    dimensions and profiles R. Bashir,a),b) A. E. Kabir,b) F. Hebert,c) and C. Brackenb) National Semiconductors. In many applications a spacer needs to be formed on the polycide sidewall Fig. 1 . Undesirable undercutting can re- sult in nonideal spacer formation for further device fabrica- tion. Tungsten silicide

  8. TungsTen--2004 79. Referencesthatincludeasectionmark()arefoundintheInternet

    E-Print Network [OSTI]

    TungsTen--2004 79. Referencesthatincludeasectionmark(§)arefoundintheInternet ReferencesCitedsection. TungsTen ByKimB.shedd Domestic survey data and tables were prepared by Amy C. Tolcin, statistical assistant, and the world production table was prepared by Glenn J. Wallace, international data coordinator

  9. Kinetics of the decomposition of tungsten hexacarbonyl

    SciTech Connect (OSTI)

    Podoprigora, V.I.; Baev, A.K.

    1987-07-20T23:59:59.000Z

    A differential-flow apparatus is devised for the study of the kinetics of the thermal decomposition of volatile metal carbonyls under quasi-stationary conditions. The applicability of the general kinetic approach to the investigation of the thermodecomposition of carbonyl compounds and of the analysis of the experimental data on the basis of specific thermodecomposition rates was proved. Well-founded kinetic characteristics were obtained for the first time for the thermodecomposition of tungsten carbonyl in the kinetic region and under quasi-stationary pyrolysis conditions.

  10. Low temperature photoresponse of monolayer tungsten disulphide

    SciTech Connect (OSTI)

    Cao, Bingchen; Shen, Xiaonan; Shang, Jingzhi; Cong, Chunxiao; Yang, Weihuang; Eginligil, Mustafa, E-mail: yuting@ntu.edu.sg, E-mail: meginligil@ntu.edu.sg [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371 (Singapore); Yu, Ting, E-mail: yuting@ntu.edu.sg, E-mail: meginligil@ntu.edu.sg [Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371 (Singapore); Department of Physics, Faculty of Science, National University of Singapore, Singapore, 117542 (Singapore); Graphene Research Centre, National University of Singapore, Singapore, 117546 (Singapore)

    2014-11-01T23:59:59.000Z

    High photoresponse can be achieved in monolayers of transition metal dichalcogenides. However, the response times are inconveniently limited by defects. Here, we report low temperature photoresponse of monolayer tungsten disulphide prepared by exfoliation and chemical vapour deposition (CVD) method. The exfoliated device exhibits n-type behaviour; while the CVD device exhibits intrinsic behaviour. In off state, the CVD device has four times larger ratio of photoresponse for laser on/off and photoresponse decay–rise times are 0.1 s (limited by our setup), while the exfoliated device has few seconds. These findings are discussed in terms of charge trapping and localization.

  11. Tungsten Mountain Geothermal Area | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are being directedAnnualProperty Edit withTianlin Baxin HydropowerTrinity Thermal Systems JumpTrueTullahomaTungsten

  12. Corrosion and wear resistance of tungsten carbide-cobalt and tungsten carbide-cobalt-chromium thermal spray coatings

    SciTech Connect (OSTI)

    Quets, J.; Alford, J.R.

    1999-07-01T23:59:59.000Z

    Tungsten carbide thermal spray coatings provide wear surfaces to new and overhauled components for various industries. Their wear resistance is obtained by incorporating small tungsten carbide particles into a metal matrix. This presentation will show what parameters influence their corrosion resistance in the ASTM B-117 Salt Spray Corrosion Test,

  13. Tungsten Transport in JET H-mode Plasmas in Hybrid Scenario, Experimental Observations and Modelling

    E-Print Network [OSTI]

    Tungsten Transport in JET H-mode Plasmas in Hybrid Scenario, Experimental Observations and Modelling

  14. Author's personal copy Tungsten geochemistry and implications for understanding the Earth's interior

    E-Print Network [OSTI]

    Mcdonough, William F.

    Author's personal copy Tungsten geochemistry and implications for understanding the Earth Keywords: tungsten uranium basalt core mantle concentration ratio The concentration of tungsten (W of tungsten (W) was sequestered into the core (Jagoutz et al., 1979; Sun, 1982; Newsom and Palme, 1984

  15. Failure Modes of Vacuum Plasma Spray Tungsten Coating Created on Carbon Fibre Composites under Thermal Loads

    E-Print Network [OSTI]

    Failure Modes of Vacuum Plasma Spray Tungsten Coating Created on Carbon Fibre Composites under Thermal Loads

  16. TUNGSTEN--2003 79.1 References that include a section mark () are found in the Internet

    E-Print Network [OSTI]

    Stockpile (NDS) and increases in stocks held by U.S. industry. No U.S. tungsten mine production was reported reported in 2001. Salient U.S. tungsten statistics and world tungsten concentrate production for 2003TUNGSTEN--2003 79.1 1 References that include a section mark (§) are found in the Internet

  17. Process for removing halogenated aliphatic and aromatic compounds from petroleum products

    DOE Patents [OSTI]

    Googin, J.M.; Napier, J.M.; Travaglini, M.A.

    1983-09-20T23:59:59.000Z

    A process is described for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contacting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible compound, such as, water or a polyhydroxy compound, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of water or polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the water or polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds and the low polar or nonpolar solvent are separated by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered from recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced. 1 fig.

  18. Process for removing halogenated aliphatic and aromatic compounds from petroleum products

    DOE Patents [OSTI]

    Googin, John M. (Oak Ridge, TN); Napier, John M. (Oak Ridge, TN); Travaglini, Michael A. (Oliver Springs, TN)

    1983-01-01T23:59:59.000Z

    A process for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contacting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible compound, such as, water or a polyhydroxy compound, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of water or polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the water or polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds and the low polar or nonpolar solvent are separated by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered from recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced.

  19. Preparation and electrocatalytic activity of tungsten carbide and titania nanocomposite

    SciTech Connect (OSTI)

    Hu, Sujuan; Shi, Binbin; Yao, Guoxing [State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, School of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China)] [State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, School of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China); Li, Guohua, E-mail: nanozjut@zjut.edu.cn [State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, School of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China)] [State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, School of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China); Ma, Chunan [State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, School of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China)] [State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, School of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032 (China)

    2011-10-15T23:59:59.000Z

    Graphical abstract: The electrocatalytic activity of tungsten carbide and titania nanocomposite is related to the structure, crystal phase and chemical components of the nanocomposite, and is also affected by the property of electrolyte. A synergistic effect exists between tungsten carbide and titania of the composite. Highlights: {yields} Electrocatalytic activity of tungsten carbide and titania nanocomposite with core-shell structure. {yields} Activity is related to the structure, crystal phase and chemical component of the nanocomposite. {yields} The property of electrolyte affects the electrocatalytic activity. {yields} A synergistic effect exists between tungsten carbide and titania of the composite. -- Abstract: Tungsten carbide and titania nanocomposite was prepared by combining a reduced-carbonized approach with a mechanochemical approach. The samples were characterized by X-ray diffraction, transmission electron microscope under scanning mode and X-ray energy dispersion spectrum. The results show that the crystal phases of the samples are composed of anatase, rutile, nonstoichiometry titanium oxide, monotungsten carbide, bitungsten carbide and nonstoichiometry tungsten carbide, and they can be controlled by adjusting the parameters of the reduced-carbonized approach; tungsten carbide particles decorate on the surface of titania support, the diameter of tungsten carbide particle is smaller than 20 nm and that of titania is around 100 nm; the chemical components of the samples are Ti, O, W and C. The electrocatalytic activity of the samples was measured by a cyclic voltammetry with three electrodes. The results indicate that the electrocatalytic activities of the samples are related to their crystal phases and the property of electrolyte in aqueous solution. A synergistic effect between titania and tungsten carbide is reported for the first time.

  20. Analysis of Halogen-Mercury Reactions in Flue Gas

    SciTech Connect (OSTI)

    Paula Buitrago; Geoffrey Silcox; Constance Senior; Brydger Van Otten

    2010-01-01T23:59:59.000Z

    Oxidized mercury species may be formed in combustion systems through gas-phase reactions between elemental mercury and halogens, such as chorine or bromine. This study examines how bromine species affect mercury oxidation in the gas phase and examines the effects of mixtures of bromine and chlorine on extents of oxidation. Experiments were conducted in a bench-scale, laminar flow, methane-fired (300 W), quartz-lined reactor in which gas composition (HCl, HBr, NO{sub x}, SO{sub 2}) and temperature profile were varied. In the experiments, the post-combustion gases were quenched from flame temperatures to about 350 C, and then speciated mercury was measured using a wet conditioning system and continuous emissions monitor (CEM). Supporting kinetic calculations were performed and compared with measured levels of oxidation. A significant portion of this report is devoted to sample conditioning as part of the mercury analysis system. In combustion systems with significant amounts of Br{sub 2} in the flue gas, the impinger solutions used to speciate mercury may be biased and care must be taken in interpreting mercury oxidation results. The stannous chloride solution used in the CEM conditioning system to convert all mercury to total mercury did not provide complete conversion of oxidized mercury to elemental, when bromine was added to the combustion system, resulting in a low bias for the total mercury measurement. The use of a hydroxylamine hydrochloride and sodium hydroxide solution instead of stannous chloride showed a significant improvement in the measurement of total mercury. Bromine was shown to be much more effective in the post-flame, homogeneous oxidation of mercury than chlorine, on an equivalent molar basis. Addition of NO to the flame (up to 400 ppmv) had no impact on mercury oxidation by chlorine or bromine. Addition of SO{sub 2} had no effect on mercury oxidation by chlorine at SO{sub 2} concentrations below about 400 ppmv; some increase in mercury oxidation was observed at SO{sub 2} concentrations of 400 ppmv and higher. In contrast, SO{sub 2} concentrations as low as 50 ppmv significantly reduced mercury oxidation by bromine, this reduction could be due to both gas and liquid phase interactions between SO{sub 2} and oxidized mercury species. The simultaneous presence of chlorine and bromine in the flue gas resulted in a slight increase in mercury oxidation above that obtained with bromine alone, the extent of the observed increase is proportional to the chlorine concentration. The results of this study can be used to understand the relative importance of gas-phase mercury oxidation by bromine and chlorine in combustion systems. Two temperature profiles were tested: a low quench (210 K/s) and a high quench (440 K/s). For chlorine the effects of quench rate were slight and hard to characterize with confidence. Oxidation with bromine proved sensitive to quench rate with significantly more oxidation at the lower rate. The data generated in this program are the first homogeneous laboratory-scale data on bromine-induced oxidation of mercury in a combustion system. Five Hg-Cl and three Hg-Br mechanisms, some published and others under development, were evaluated and compared to the new data. The Hg-halogen mechanisms were combined with submechanisms from Reaction Engineering International for NO{sub x}, SO{sub x}, and hydrocarbons. The homogeneous kinetics under-predicted the levels of mercury oxidation observed in full-scale systems. This shortcoming can be corrected by including heterogeneous kinetics in the model calculations.

  1. Tungsten-doped thin film materials

    DOE Patents [OSTI]

    Xiang, Xiao-Dong; Chang, Hauyee; Gao, Chen; Takeuchi, Ichiro; Schultz, Peter G.

    2003-12-09T23:59:59.000Z

    A dielectric thin film material for high frequency use, including use as a capacitor, and having a low dielectric loss factor is provided, the film comprising a composition of tungsten-doped barium strontium titanate of the general formula (Ba.sub.x Sr.sub.1-x)TiO.sub.3, where X is between about 0.5 and about 1.0. Also provided is a method for making a dielectric thin film of the general formula (Ba.sub.x Sr.sub.1-x)TiO.sub.3 and doped with W, where X is between about 0.5 and about 1.0, a substrate is provided, TiO.sub.2, the W dopant, Ba, and optionally Sr are deposited on the substrate, and the substrate containing TiO.sub.2, the W dopant, Ba, and optionally Sr is heated to form a low loss dielectric thin film.

  2. Heat transfer in gas tungsten arc welding

    SciTech Connect (OSTI)

    Smartt, H.B.; Stewart, J.A.; Einerson, C.J.

    1986-05-01T23:59:59.000Z

    The heat transferred from an electrode negative, argon gas tungsten arc to an anode has been measured for a wide range of conditions suitable for mechanized welding applications. The results are given as (1) the arc efficiency; and (2) the anode heat and current input distribution functional shapes and radii for various anode materials and groove shapes over a wide range of current and voltage, using different electrode geometries, as well as both He and Ar-He shielding gases. The nominal arc is Gaussian with a diameter of about 4 mm and a heat transfer efficiency to the anode of about 75%. Variations from these values are discussed in terms of current knowledge of the electrical and thermal energy transport mechanisms. A new method of measuring the heat transferred from the arc to the anode, using a boiling liquid nitrogen calorimeter, has been developed which gives rapid, accurate values.

  3. TUNGSTEN--1999 80.1 By Kim B. Shedd

    E-Print Network [OSTI]

    , and/or contacts are used in lighting, electronic, electrical, heating, and welding applications and coatings. Chemical uses of tungsten include catalysts, inorganic pigments, and high-temperature lubricants

  4. TUNGSTEN--1998 80.1 By Kim B. Shedd

    E-Print Network [OSTI]

    , and/or contacts are used in lighting, electronic, electrical, heating, and welding applications and coatings. Chemical uses of tungsten include catalysts, inorganic pigments, and high-temperature lubricants

  5. Atomistic computer simulation analysis of nanocrystalline nickel-tungsten alloys

    E-Print Network [OSTI]

    Engwall, Alison Michelle

    2009-01-01T23:59:59.000Z

    Nanocrystalline nickel-tungsten alloys are harder, stronger, more resistant to degradation, and safer to electrodeposit than chromium. Atomistic computer simulations have previously met with success in replicating the ...

  6. Microstructured tungsten thermophotovoltaic selective emitters c by Natalija (Zorana) Jovanovi?.

    E-Print Network [OSTI]

    Jovanovic, Natalija Zorana

    2008-01-01T23:59:59.000Z

    This research investigates the fabrication, modeling, characterization, and application of tungsten two-dimensional (2D) photonic crystal (PhC) structures as selective emitters and means of achieving higher efficiencies ...

  7. Alkyne metathesis by molybdenum and tungsten alkylidyne complexes

    E-Print Network [OSTI]

    Schrock, Richard Royce

    Alkyne metathesis by molybdenum and tungsten alkylidyne complexes is now ~45 years old. Progress in the practical aspects of alkyne metathesis reactions with well-defined complexes, as well as applications, in the last ...

  8. Tungsten carbide-cobalt by Three Dimensional Printing

    E-Print Network [OSTI]

    Kelley, Andrew, III

    1998-01-01T23:59:59.000Z

    Three Dimensional Printing is an additive manufacturing process for rapid prototyping ceramic and metallic parts [Sachs, et al, 1990]. Green (not sintered) tungsten carbide-cobalt parts must have a density greater than 50% ...

  9. Student Spotlight

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearch >Internship Program The NIF and Photon Science Directorate often

  10. Employee Spotlight

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContractElectron-State HybridizationSecurity /MaterialsPKGWhere

  11. Student Spotlight

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengthening a solid ... Strengthening aStructureStudent Programs andAlexandra

  12. Student Spotlight

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengthening a solid ... Strengthening aStructureStudent Programs

  13. Student Spotlight

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengthening a solid ... Strengthening aStructureStudent ProgramsMekena McGrew

  14. Student Spotlight

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengthening a solid ... Strengthening aStructureStudent ProgramsMekena

  15. Student Spotlight

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengthening a solid ... Strengthening aStructureStudent ProgramsMekenaZobrist

  16. Surface Coating of Tungsten Carbide by Electric Exploding of Contact

    SciTech Connect (OSTI)

    Grigoryev, Evgeny G. [General Physics Department, Moscow Engineering Physics Institute, Kashirskoe sh. 31, Moscow, 115409 (Russian Federation)

    2011-01-17T23:59:59.000Z

    Electric exploding of a tungsten carbide--cobalt material near-by high-speed steel surface forms on it a hardening coating. The essential structure properties of the formed coatings are determined by parameters of contact exploding electrode at the pulse current amplitude from above 106 A/cm2 and duration less than 10-4 s. The metallographic investigations of coating structures were done by microscope 'Neophot-24'. They have shown that the contact electric exploding caused the transfer of tungsten carbide and cobalt on the surface of high-speed steel. The breakdown of tungsten carbide--cobalt material took place during electrical exploding. The hardening layers of tungsten carbide and pure nanocrystalline tungsten have been formed upon the surface of high-speed steel as a result of electric exploding. Crystalline grains of tungsten have an almost spherical form and their characteristic size less than 400 nanometers. Micro hardness of the coating layers and high-speed steel structures was measured.

  17. T-1018 UCLA Spacordion Tungsten Powder Calorimeter

    SciTech Connect (OSTI)

    Trentalange, Stephen; Tsai, Oleg; Igo, George; Huang, Huan; Pan, Yu Xi; Dunkelberger, Jay; Xu, Wen Qin; /UCLA; Soha, Aria; /Fermilab; Heppelmann, Steven; /Penn State U.; Gagliardi, Carl; /Texas A-M

    2011-11-16T23:59:59.000Z

    The present experiments at the BNL-RHIC facility are evolving towards physics goals which require the detection of medium energy electromagnetic particles (photons, electrons, neutral pions, eta mesons, etc.), especially at forward angles. New detectors will place increasing demands on energy resolution, hadron rejection and two-photon resolution and will require large area, high performance electromagnetic calorimeters in a variety of geometries. In the immediate future, either RHIC or JLAB will propose a facility upgrade (Electron-Ion Collider, or EIC) with physics goals such as electron-heavy ion collisions (or p-A collisions) with a wide range of calorimeter requirements. An R and D program based at Brookhaven National Laboratory has awarded the group funding of approximately $110,000 to develop new types of calorimeters for EIC experiments. The UCLA group is developing a method to manufacture very flexible and cost-effective, yet high quality calorimeters based on scintillating fibers and tungsten powder. The design and features of the calorimeter can be briefly stated as follows: an arbitrarily large number of small diameter fibers (< 0.5 mm) are assembled as a matrix and held rigidly in place by a set of precision screens inside an empty container. The container is then back-filled with tungsten powder, compacted on a vibrating table and infused with epoxy under vacuum. The container is then removed. The resulting sub-modules are extremely uniform and achieve roughly the density of pure Lead. The sub-modules are stacked together to achieve a final detector of the desired shape. There is no dead space between sub-modules and the fibers can be in an accordion geometry bent to prevent 'channeling' of the particles due to accidental alignment of their track with the module axis. This technology has the advantage of being modular and inexpensive to the point where the construction work may be divided among groups the size of typical university physics departments. This test run if a proof-of-principle and allows the experiment to improve the design and performance of the final detectors. The experimenters have constructed prototypes of three different designs in order to investigate the characteristics of practical devices such as uniformity, linearity, longitudinal and transverse shower shapes. The first design is an array of 4 x 4 modules intended as a prototype for a practical device to be installed within two years in the STAR experimental hall. The modules are a combination of a spaghetti calorimeter and an accordion (hence 'spacordion'). Each sub-module is 1.44 cm x 1.44 cm x 15 cm and constructed individually. The second design is a prototype of 4 sub-modules constructed in one step, using a different construction technique. The third design is a set of single sub-modules each intended to test variations of the tungsten powder/embedded fiber concept by enhancing the light output/density using liquid scintillator or heavy liquids.

  18. GREEN LIVING Replace incandencent and halogen light bulbs with LED and CLFs

    E-Print Network [OSTI]

    Thaxton, Christopher S.

    GREEN LIVING GUIDE ENERGY TRAVEL FOOD sustain yosef WATER Replace incandencent and halogen light for your laundry RESIST THAT SWITCH! Use natural light during the day, and no lights when you are gone USE MORE THAN YOU CAN EAT, reduce your waste stream DRINK FAIR TRADE COFFEE - Check out Conrad

  19. Low-Level Detections of Halogenated Volatile Organic Compounds in Groundwater

    E-Print Network [OSTI]

    compounds; Groundwater management; Drinking water. Introduction Approximately one-half of the U and Hitt 2006 , or more complex process-based analyses utilizing groundwater models Eberts et al. 2005Low-Level Detections of Halogenated Volatile Organic Compounds in Groundwater: Use in Vulnerability

  20. Low-temperature chemical vapor deposition of tungsten from tungsten hexacarbonyl

    SciTech Connect (OSTI)

    Vogt, G.J.

    1982-04-01T23:59:59.000Z

    Chemical vapor deposition (CVD) of tungsten from W(CO)/sub 6/ has been investigated below 670 K as an alternate process to WF/sub 6/ CVD for coating glass microspheres. The major advantages of W(CO)/sub 6/ CVD are the elimination of the HF damage to the glass microspheres and potentially a lower deposition temperature for coating DT-filled microspheres. W(CO)/sub 6/ CVD can be utilized, in principle, to coat the microspheres with 1 to 5 ..mu..m of tungsten or to flash coat the microspheres for further coating by WF/sub 6/ CVD. Test coatings were deposited in a fluidized-bed reactor with a hydrogen carrier gas. The coatings were found to contain nearly equal portions of carbon and oxygen, ranging from 16 to 25 at.% for each element. The high carbon and oxygen concentrations are believed to result principally from the physical entrapment of chemisorbed CO molecules at the surface of the growing deposit. The general quality and adhesion of the W(CO)/sub 6/-derived coatings are unsatisfactory at this time for ICF applications.

  1. PHYSICAL REVIEW B 84, 092102 (2011) Melting temperature of tungsten from two ab initio approaches

    E-Print Network [OSTI]

    Alfè, Dario

    2011-01-01T23:59:59.000Z

    PHYSICAL REVIEW B 84, 092102 (2011) Melting temperature of tungsten from two ab initio approaches L the melting temperature of tungsten by two ab initio approaches. The first approach can be divided into two

  2. Structure-property Relationships in Pure and Doped Epitaxial Tungsten Trioxide Thin Films

    E-Print Network [OSTI]

    Structure-property Relationships in Pure and Doped Epitaxial Tungsten Trioxide Thin Films Principal-property relationships of well- defined epitaxial tungsten trioxide (WO3) films with and without dopants, and thereby

  3. Olefin Metathesis Reactions Initiated by d2 Molybdenum or Tungsten Complexes

    E-Print Network [OSTI]

    Müller, Peter

    Olefin Metathesis Reactions Initiated by d2 Molybdenum or Tungsten Complexes Richard R. Schrock species, behave as olefin metathesis catalysts. Recently we reported tungsten complexes that contain a Wd

  4. Room-Temperature Z-Selective Homocoupling of alpha-Olefins by Tungsten Catalysts

    E-Print Network [OSTI]

    Marinescu, Smaranda C.

    3,5-Dimethylphenylimido complexes of tungsten can be prepared using procedures analogous to those employed for other tungsten catalysts, as can bispyrrolide species and MonoAryloxide-Pyrrolide (MAP) species. Homocouplings ...

  5. Spotlight SAR interferometry for terrain elevation mapping and interferometric change detection

    SciTech Connect (OSTI)

    Eichel, P.H.; Ghiglia, D.C.; Jakowatz, C.V. Jr. [and others

    1996-02-01T23:59:59.000Z

    In this report, we employ an approach quite different from any previous work; we show that a new methodology leads to a simpler and clearer understanding of the fundamental principles of SAR interferometry. This methodology also allows implementation of an important collection mode that has not been demonstrated to date. Specifically, we introduce the following six new concepts for the processing of interferometric SAR (INSAR) data: (1) processing using spotlight mode SAR imaging (allowing ultra-high resolution), as opposed to conventional strip-mapping techniques; (2) derivation of the collection geometry constraints required to avoid decorrelation effects in two-pass INSAR; (3) derivation of maximum likelihood estimators for phase difference and the change parameter employed in interferometric change detection (ICD); (4) processing for the two-pass case wherein the platform ground tracks make a large crossing angle; (5) a robust least-squares method for two-dimensional phase unwrapping formulated as a solution to Poisson`s equation, instead of using traditional path-following techniques; and (6) the existence of a simple linear scale factor that relates phase differences between two SAR images to terrain height. We show both theoretical analysis, as well as numerous examples that employ real SAR collections to demonstrate the innovations listed above.

  6. A history of tungsten- and molybdenum-base alloys

    SciTech Connect (OSTI)

    Heestand, R.L.

    1993-01-01T23:59:59.000Z

    The development of tungsten and molybdenum alloys was initiated in the early 1900s in search of a better electric lamp filament with tantalum, tungsten, rhenium, and osmium being the prime candidates. The efforts required for accomplishment of the task led to refining oxides to high purity, reduction of the oxides to metal powders, forming green product forms by extrusion or pressing, and finally sintering by electric furnace and self-heating by direct current almost to the melting point. The technology required for producing lamp filaments led to the development of the powder metallurgy field and early research on high-melting-temperature metals. During the period 1909 through 1959, most of the tungsten-molybdenum, high-melting-temperature element alloys were developed and produced in almost any product form required.

  7. A history of tungsten- and molybdenum-base alloys

    SciTech Connect (OSTI)

    Heestand, R.L.

    1993-05-01T23:59:59.000Z

    The development of tungsten and molybdenum alloys was initiated in the early 1900s in search of a better electric lamp filament with tantalum, tungsten, rhenium, and osmium being the prime candidates. The efforts required for accomplishment of the task led to refining oxides to high purity, reduction of the oxides to metal powders, forming green product forms by extrusion or pressing, and finally sintering by electric furnace and self-heating by direct current almost to the melting point. The technology required for producing lamp filaments led to the development of the powder metallurgy field and early research on high-melting-temperature metals. During the period 1909 through 1959, most of the tungsten-molybdenum, high-melting-temperature element alloys were developed and produced in almost any product form required.

  8. Mechanism of vacancy formation induced by hydrogen in tungsten

    SciTech Connect (OSTI)

    Liu, Yi-Nan [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing, 100191 (China) [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing, 100191 (China); Association EURATOM-TEKES, University of Helsinki, Helsinki, PO Box 64, 00560 (Finland); Ahlgren, T.; Bukonte, L.; Nordlund, K. [Association EURATOM-TEKES, University of Helsinki, Helsinki, PO Box 64, 00560 (Finland)] [Association EURATOM-TEKES, University of Helsinki, Helsinki, PO Box 64, 00560 (Finland); Shu, Xiaolin; Yu, Yi; Lu, Guang-Hong, E-mail: LGH@buaa.edu.cn [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing, 100191 (China)] [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing, 100191 (China); Li, Xiao-Chun [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China)] [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China)

    2013-12-15T23:59:59.000Z

    We report a hydrogen induced vacancy formation mechanism in tungsten based on classical molecular dynamics simulations. We demonstrate the vacancy formation in tungsten due to the presence of hydrogen associated directly with a stable hexagonal self-interstitial cluster as well as a linear crowdion. The stability of different self-interstitial structures has been further studied and it is particularly shown that hydrogen plays a crucial role in determining the configuration of SIAs, in which the hexagonal cluster structure is preferred. Energetic analysis has been carried out to prove that the formation of SIA clusters facilitates the formation of vacancies. Such a mechanism contributes to the understanding of the early stage of the hydrogen blistering in tungsten under a fusion reactor environment.

  9. Ductile tungsten-nickel alloy and method for making same

    DOE Patents [OSTI]

    Snyder, Jr., William B. (Knoxville, TN)

    1976-01-01T23:59:59.000Z

    The present invention is directed to a ductile, high-density tungsten-nickel alloy which possesses a tensile strength in the range of 100,000 to 140,000 psi and a tensile elongation of 3.1 to 16.5 percent in 1 inch at 25.degree.C. This alloy is prepared by the steps of liquid phase sintering a mixture of tungsten-0.5 to 10.0 weight percent nickel, heat treating the alloy at a temperature above the ordering temperature of approximately 970.degree.C. to stabilize the matrix phase, and thereafter rapidly quenching the alloy in a suitable liquid to maintain the matrix phase in a metastable, face-centered cubic, solid- solution of tungsten in nickel.

  10. Tungsten as first wall material in the main chamber of ASDEX Upgrade

    E-Print Network [OSTI]

    Tungsten as first wall material in the main chamber of ASDEX Upgrade V. Rohde, R. Neu, A. Geier, R material is tungsten, which has a high melting point, low erosion rate in cold scrape off layer plasma, where the present ITER-FEAT design uses tungsten. No negative influence on the plasma performance, even

  11. DOI: 10.1002/adsc.201100200 Preparation of Tungsten-Based Olefin Metathesis Catalysts

    E-Print Network [OSTI]

    Müller, Peter

    DOI: 10.1002/adsc.201100200 Preparation of Tungsten-Based Olefin Metathesis Catalysts Supported://dx.doi.org/10.1002/adcs.201100200. Abstract: A new tungsten alkylidene complex, WACHTUNGTRENNUNG catalysts; tungsten Introduction In the last dozen years various "well-defined" Mo/W[1] or Ru[2] olefin

  12. ORIGINAL PAPER Why is the molybdenum-substituted tungsten-dependent

    E-Print Network [OSTI]

    Liao, Rongzhen

    ORIGINAL PAPER Why is the molybdenum-substituted tungsten-dependent formaldehyde ferredoxin oxidoreductase is a tungsten-dependent enzyme that catalyzes the oxidative degradation of formaldehyde to formic acid. The moly- bdenum ion can be incorporated into the active site to displace the tungsten ion

  13. Syntheses of Tungsten tert-Butylimido and Adamantylimido Alkylidene Complexes Employing Pyridinium Chloride As the Acid

    E-Print Network [OSTI]

    Müller, Peter

    Syntheses of Tungsten tert-Butylimido and Adamantylimido Alkylidene Complexes Employing Pyridinium Supporting Information ABSTRACT: Routes to new tungsten alkylidene complexes that contain tert and tungsten, especially aryls that are mono- or disubstituted in the ortho position(s).2 However, it has

  14. Single-Crystal Tungsten Oxide Nanosheets: Photochemical Water Oxidation in the Quantum Confinement Regime

    E-Print Network [OSTI]

    Osterloh, Frank

    Single-Crystal Tungsten Oxide Nanosheets: Photochemical Water Oxidation in the Quantum Confinement, catalysis, WO3, tungsten oxide, nanosheet, nanocrystal, quantum confinement, solar energy conversion INTRODUCTION Tungsten trioxide crystallizes in the ReO3 structure type and is an n-type semiconductor with a 2

  15. Synthesis and Reactions of Tungsten Alkylidene Complexes That Contain the 2,6-Dichlorophenylimido Ligand

    E-Print Network [OSTI]

    Müller, Peter

    Synthesis and Reactions of Tungsten Alkylidene Complexes That Contain the 2,6-Dichlorophenylimido Institute of Technology, Cambridge, Massachusetts 02139 ReceiVed October 30, 2006 Tungsten alkylidene alkylidene bisalkoxide complexes of molybdenum or tungsten of the type M(NR)(CHR)(OR)2 are now established

  16. Imido Alkylidene Bispyrrolyl Complexes of Tungsten Thorsten Kreickmann, Stefan Arndt, Richard R. Schrock,* and Peter Muller

    E-Print Network [OSTI]

    Müller, Peter

    Imido Alkylidene Bispyrrolyl Complexes of Tungsten Thorsten Kreickmann, Stefan Arndt, Richard R, Massachusetts 02139 ReceiVed July 16, 2007 We have prepared tungsten bispyrrolyl (Pyr) or bis-2 this type of chemistry to tungsten. In this paper we report W(NR)(CHCMe2R)(pyrrolyl)2 complexes where R is 2

  17. Nanostructured tungsten carbide catalysts for polymer electrolyte fuel cells X. G. Yanga

    E-Print Network [OSTI]

    Nanostructured tungsten carbide catalysts for polymer electrolyte fuel cells X. G. Yanga and C. Y/air polymer electrolyte fuel cell using nanoscale tungsten carbide as the anode catalyst and carbon supported, thereby creating a fundamental technology to reduce the cost of future fuel cell engines. The tungsten

  18. Radial x-ray diffraction of tungsten tetraboride to 86 GPa under nonhydrostatic compression

    E-Print Network [OSTI]

    Lin, Jung-Fu "Afu"

    Radial x-ray diffraction of tungsten tetraboride to 86 GPa under nonhydrostatic compression Lun December 2012; published online 16 January 2013) Investigations of the equation of state of tungsten moduli and hardness exceed- ing or closing that of diamond. Tungsten tetraboride (WB4) is a candidate

  19. Z-Selective Olefin Metathesis Reactions Promoted by Tungsten Oxo Alkylidene Complexes

    E-Print Network [OSTI]

    Müller, Peter

    Z-Selective Olefin Metathesis Reactions Promoted by Tungsten Oxo Alkylidene Complexes Dmitry V). Early in the development of olefin metathesis catalysts that contain tungsten, it was shown that metathetically more active and reproducible systems were produced when tungsten oxo complexes were deliberately

  20. Compressibility and strength of nanocrystalline tungsten boride under compression to 60GPa

    E-Print Network [OSTI]

    Duffy, Thomas S.

    Compressibility and strength of nanocrystalline tungsten boride under compression to 60GPa Haini://jap.aip.org/about/rights_and_permissions #12;Compressibility and strength of nanocrystalline tungsten boride under compression to 60 GPa Haini of nanocrystalline tungsten boride (WB) were investigated using radial x-ray diffraction (RXRD) in a diamond

  1. Synthesis of Tungsten Imido Alkylidene Complexes that Contain an Electron-Withdrawing Imido Ligand

    E-Print Network [OSTI]

    Müller, Peter

    Synthesis of Tungsten Imido Alkylidene Complexes that Contain an Electron-Withdrawing Imido Ligand 02467, United States *S Supporting Information ABSTRACT: Tungsten NArR alkylidene complexes have been is the nature of Z. Perhaps the most dramatic variations are those in which M is tungsten and Z is an oxo ligand

  2. Mechanism of tungsten-dependent acetylene hydratase from quantum chemical calculations

    E-Print Network [OSTI]

    Liao, Rongzhen

    Mechanism of tungsten-dependent acetylene hydratase from quantum chemical calculations Rong hydratase is a tungsten-dependent enzyme that cata- lyzes the nonredox hydration of acetylene metalloenzyme cluster approach Tungsten is the heaviest metal in biology and plays prominent roles in carbon

  3. Real-time growth rate metrology for a tungsten chemical vapor deposition process by acoustic sensing

    E-Print Network [OSTI]

    Rubloff, Gary W.

    to a production-scale tungsten chemical vapor deposition cluster tool for in situ process sensing. Process gasesReal-time growth rate metrology for a tungsten chemical vapor deposition process by acoustic to achieve run-to-run process control of the deposited tungsten film thickness. © 2001 American Vacuum

  4. The Corrosion of Tungsten During Irradiation in an 800 MeV Proton Beam

    E-Print Network [OSTI]

    such technology is Accelerator Production of Tritium (APT). In APT a tungsten target is bombarded by a high energyThe Corrosion of Tungsten During Irradiation in an 800 MeV Proton Beam R. Scott Lillard, Darryl P of solid neutron spallation targets such as tungsten (W), and target cladding or structural materials

  5. Halogen emissions from a small volcanic eruption: Modeling the peak concentrations, dispersion, and volcanically induced ozone loss in the

    E-Print Network [OSTI]

    Rose, William I.

    , with lesser quantities of H2S, H2 and CO. Volcanic emissions also often include halogen-bearing species, and the greater water vapor content in the lower troposphere at tropical latitudes, which enhance removal

  6. Oxidative halogenation of cisplatin and carboplatin: synthesis, spectroscopy, and crystal and molecular structures of Pt(IV) prodrugs

    E-Print Network [OSTI]

    Alexander, Sarah M.

    A series of Pt(IV) prodrugs has been obtained by oxidative halogenation of either cisplatin or carboplatin. Iodobenzene dichloride is a general reagent that cleanly provides prodrugs bearing axial chlorides without the ...

  7. Material Mixing of Tungsten with Carbon and Helium

    SciTech Connect (OSTI)

    Ueda, Y.; Lee, H. T. [Graduate School of Engineering, Osaka University, 2-1 Yamada-Oka, Suita, Osaka 565-0871 (Japan)

    2010-05-20T23:59:59.000Z

    In ITER, graphite and tungsten are used for divertor materials and are mixed through erosion, transport, and redeposition. Helium, a fusion reactant, is an intrinsic element in fusion plasmas that impinges on the metallic wall materials to form He bubbles. W-C mixed layers and He bubble layers greatly affect tritium retention. In this paper, impacts of W-C material mixing on erosion and hydrogen isotope retention are reviewed. Then, recent results on carbon deposition on tungsten in TEXTOR tokamak and helium effects on blistering and retention are discussed.

  8. Production And Characterization Of Tungsten-Based Positron Moderators

    SciTech Connect (OSTI)

    Lucio, O. G. de; Morales, J. G.; Cruz-Manjarrez, H. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364 01000, Mexico DF (Mexico)

    2011-06-01T23:59:59.000Z

    Experiments of interest in Atomic Physics require production of well-defined low-energy positron beams through a moderation process of high-energy positrons, which can be produced by either the use of a radioactive source or by accelerator based pair production process. Tungsten is one of the most commonly used moderator materials because of its reasonable efficiency, high work function and relatively low cost. In this work we present different methods to produce tungsten-based candidate moderators in a variety of shapes. We also present results from characterizing these candidate moderators by ion beam analysis and microscopy techniques.

  9. Effects of sequential tungsten and helium ion implantation on nano-indentation hardness of tungsten

    SciTech Connect (OSTI)

    Armstrong, D. E. J.; Edmondson, P. D.; Roberts, S. G. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom)] [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom)

    2013-06-24T23:59:59.000Z

    To simulate neutron and helium damage in a fusion reactor first wall sequential self-ion implantation up to 13 dpa followed by helium-ion implantation up to 3000 appm was performed to produce damaged layers of {approx}2 {mu}m depth in pure tungsten. The hardness of these layers was measured using nanoindentation and was studied using transmission electron microscopy. Substantial hardness increases were seen in helium implanted regions, with smaller hardness increases in regions which had already been self-ion implanted, thus, containing pre-existing dislocation loops. This suggests that, for the same helium content, helium trapped in distributed vacancies gives stronger hardening than helium trapped in vacancies condensed into dislocation loops.

  10. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2006,

    E-Print Network [OSTI]

    178 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2006, approximately. Import Sources (2002-05): Tungsten contained in ores and concentrates, intermediate and primary products

  11. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2003,

    E-Print Network [OSTI]

    180 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2003, approximately and concentrates, intermediate and primary products, wrought and unwrought tungsten, and waste and scrap: China, 49

  12. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2005,

    E-Print Network [OSTI]

    182 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2005, approximately. Import Sources (2001-04): Tungsten contained in ores and concentrates, intermediate and primary products

  13. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last recorded U.S. production of tungsten concentrates was in 1994. In 2001,

    E-Print Network [OSTI]

    180 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last recorded U.S. production of tungsten concentrates was in 1994. In 2001, approximately, intermediate and primary products, wrought and unwrought tungsten, and waste and scrap: China, 41%; Russia, 21

  14. (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2002,

    E-Print Network [OSTI]

    182 TUNGSTEN (Data in metric tons of tungsten content, unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2002, approximately, intermediate and primary products, wrought and unwrought tungsten, and waste and scrap: China, 48%; Russia, 16

  15. (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2004,

    E-Print Network [OSTI]

    180 TUNGSTEN (Data in metric tons of tungsten content unless otherwise noted) Domestic Production and Use: The last reported U.S. production of tungsten concentrates was in 1994. In 2004, approximately (2000-03): Tungsten content of ores and concentrates, intermediate and primary products, wrought

  16. Method of increments for the halogen molecular crystals: Cl, Br, and I

    SciTech Connect (OSTI)

    Steenbergen, Krista G. [Physikalische und Theoretische Chemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin (Germany); MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, P.O. Box 600, Wellington 6012 (New Zealand); Gaston, Nicola [MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, P.O. Box 600, Wellington 6012 (New Zealand); Müller, Carsten; Paulus, Beate [Physikalische und Theoretische Chemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin (Germany)

    2014-09-28T23:59:59.000Z

    Method of increments (MI) calculations reveal the n-body correlation contributions to binding in solid chlorine, bromine, and iodine. Secondary binding contributions as well as d-correlation energies are estimated and compared between each solid halogen. We illustrate that binding is entirely determined by two-body correlation effects, which account for >80% of the total correlation energy. One-body, three-body, and exchange contributions are repulsive. Using density-fitting (DF) local coupled-cluster singles, doubles, and perturbative triples for incremental calculations, we obtain excellent agreement with the experimental cohesive energies. MI results from DF local second-order Møller-Plesset perturbation (LMP2) yield considerably over-bound cohesive energies. Comparative calculations with density functional theory and periodic LMP2 method are also shown to be less accurate for the solid halogens.

  17. Photofragmentation spectra of halogenated methanes in the VUV photon energy range

    SciTech Connect (OSTI)

    Cartoni, Antonella, E-mail: antonella.cartoni@uniroma1.it [Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, P.le Aldo Moro 5, Roma 00185 (Italy)] [Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, P.le Aldo Moro 5, Roma 00185 (Italy); Bolognesi, Paola; Fainelli, Ettore; Avaldi, Lorenzo [CNR-IMIP, Area della Ricerca di Roma 1, Monterotondo Scalo (Rm) 00015 (Italy)] [CNR-IMIP, Area della Ricerca di Roma 1, Monterotondo Scalo (Rm) 00015 (Italy)

    2014-05-14T23:59:59.000Z

    In this paper an investigation of the photofragmentation of dihalomethanes CH{sub 2}X{sub 2} (X = F, Cl, Br, I) and chlorinated methanes (CH{sub n}Cl{sub 4?n} with n = 0–3) with VUV helium, neon, and argon discharge lamps is reported and the role played by the different halogen atoms is discussed. Halogenated methanes are a class of molecules used in several fields of chemistry and the study of their physical and chemical proprieties is of fundamental interest. In particular their photodissociation and photoionization are of great importance since the decomposition of these compounds in the atmosphere strongly affects the environment. The results of the present work show that the halogen-loss is the predominant fragmentation channel for these molecules in the VUV photon energy range and confirm their role as reservoir of chlorine, bromine, and iodine atoms in the atmosphere. Moreover, the results highlight the peculiar feature of CH{sub 2}F{sub 2} as a source of both fluorine and hydrogen atoms and the characteristic formation of I{sub 2}{sup +} and CH{sub 2}{sup +} ions from the photofragmentation of the CH{sub 2}I{sub 2} molecule.

  18. Tungsten and tungsten alloy powder metallurgy: Powder production and applications excluding lamps. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search

    SciTech Connect (OSTI)

    Not Available

    1994-04-01T23:59:59.000Z

    The bibliography contains citations of selected patents concerning the preparation of metallic and ceramic powders of tungsten and tungsten alloys, including applications of these materials. The hydrogen reduction of tungsten compounds together with alloying element compounds produce forms with characteristics of high density, hardness, wear resistance, high melting points, and abrasiveness. Topics include production of cathodes, heaters, filament wires, electrical contacts, acoustic absorbers, high-density sheets and coatings, hard penetrators, and tungsten carbide and metallized ceramics. (Contains a minimum of 109 citations and includes a subject term index and title list.)

  19. Novel Reactor Design and Metrology Study for Tungsten ALD process

    E-Print Network [OSTI]

    Rubloff, Gary W.

    species Viscous flow condition Short gas residence time Fast gas switching Reactant + carrier gas Multiple Operation Modes Exposure Purge Small reactor volume Throttle Valve 5 torr 10-5 Torr carrier gas 5 torr 10Novel Reactor Design and Metrology Study for Tungsten ALD process Laurent Henn-Lecordier, Wei Lei

  20. Retention of Hydrogen Isotopes in Neutron Irradiated Tungsten

    SciTech Connect (OSTI)

    Yuji Hatano; Masashi Shimada; Yasuhisa Oya; Guoping Cao; Makoto Kobayashi; Masanori Hara; Brad J. Merrill; Kenji Okuno; Mikhail A. Sokolov; Yutai Katoh

    2013-03-01T23:59:59.000Z

    To investigate the effects of neutron irradiation on hydrogen isotope retention in tungsten, disk-type specimens of pure tungsten were irradiated in the High Flux Isotope Reactor in Oak Ridge National Laboratory followed by exposure to high flux deuterium (D) plasma in Idaho National Laboratory. The results obtained for low dose n-irradiated specimens (0.025 dpa for tungsten) are reviewed in this paper. Irradiation at coolant temperature of the reactor (around 50 degrees C) resulted in the formation of strong trapping sites for D atoms. The concentrations of D in n-irradiated specimens were ranging from 0.1 to 0.4 mol% after exposure to D plasma at 200 and 500 degrees C and significantly higher than those in non-irradiated specimens because of D-trapping by radiation defects. Deep penetration of D up to a depth of 50-100 µm was observed at 500 degrees C. Release of D in subsequent thermal desorption measurements continued up to 900 degrees C. These results were compared with the behaviour of D in ion-irradiated tungsten, and distinctive features of n-irradiation were discussed.

  1. Tungsten-yttria carbide coating for conveying copper

    DOE Patents [OSTI]

    Rothman, Albert J. (Livermore, CA)

    1993-01-01T23:59:59.000Z

    A method is provided for providing a carbided-tungsten-yttria coating on the interior surface of a copper vapor laser. The surface serves as a wick for the condensation of liquid copper to return the condensate to the interior of the laser for revolatilization.

  2. Author's personal copy Tungsten in Hawaiian picrites: A compositional model

    E-Print Network [OSTI]

    Mcdonough, William F.

    form 15 April 2009; available online 3 May 2009 Abstract Concentrations of tungsten (W) and uranium (U is three-times as enriched as the Depleted MORB Mantle (DMM; 3.0 ± 2.3 ng/g). The relatively high of the recycling of W-rich oceanic crust and sediment into a depleted mantle source, such as the depleted MORB

  3. Development of Bulk Nanocrystalline Cemented Tungsten Carbide for Industrial Applicaitons

    SciTech Connect (OSTI)

    Z. Zak Fang, H. Y. Sohn

    2009-03-10T23:59:59.000Z

    This report contains detailed information of the research program entitled "Development of Bulk Nanocrystalline Cemented Tungsten Carbide Materials for Industrial Applications". The report include the processes that were developed for producing nanosized WC/Co composite powders, and an ultrahigh pressure rapid hot consolidation process for sintering of nanosized powders. The mechanical properties of consolidated materials using the nanosized powders are also reported.

  4. The end of the line? A spotlight on the historic US fishing port of Gloucester fails to capture the complexity of the fisheries

    E-Print Network [OSTI]

    Pauly, Daniel

    -abundantspecieswaspartlycausedbythe success of the schooner-based fishery, which, even though it relied on wind power, harvested enough is the story of Glouces- ter, Massachusetts, the oldest fishing port in the United States. Kurlansky spotlights fisheries regulators who cannot tell a bass from a cod. "Newlyn vessels had been landing more than

  5. Pitfalls of tungsten multileaf collimator in proton beam therapy

    SciTech Connect (OSTI)

    Moskvin, Vadim; Cheng, Chee-Wai; Das, Indra J. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States) and Indiana University Health Proton Therapy Center (Formerly Midwest Proton Radiotherapy Institute), Bloomington, Indiana 47408 (United States)

    2011-12-15T23:59:59.000Z

    Purpose: Particle beam therapy is associated with significant startup and operational cost. Multileaf collimator (MLC) provides an attractive option to improve the efficiency and reduce the treatment cost. A direct transfer of the MLC technology from external beam radiation therapy is intuitively straightforward to proton therapy. However, activation, neutron production, and the associated secondary cancer risk in proton beam should be an important consideration which is evaluated. Methods: Monte Carlo simulation with FLUKA particle transport code was applied in this study for a number of treatment models. The authors have performed a detailed study of the neutron generation, ambient dose equivalent [H*(10)], and activation of a typical tungsten MLC and compared with those obtained from a brass aperture used in a typical proton therapy system. Brass aperture and tungsten MLC were modeled by absorber blocks in this study, representing worst-case scenario of a fully closed collimator. Results: With a tungsten MLC, the secondary neutron dose to the patient is at least 1.5 times higher than that from a brass aperture. The H*(10) from a tungsten MLC at 10 cm downstream is about 22.3 mSv/Gy delivered to water phantom by noncollimated 200 MeV beam of 20 cm diameter compared to 14 mSv/Gy for the brass aperture. For a 30-fraction treatment course, the activity per unit volume in brass aperture reaches 5.3 x 10{sup 4} Bq cm{sup -3} at the end of the last treatment. The activity in brass decreases by a factor of 380 after 24 h, additional 6.2 times after 40 days of cooling, and is reduced to background level after 1 yr. Initial activity in tungsten after 30 days of treating 30 patients per day is about 3.4 times higher than in brass that decreases only by a factor of 2 after 40 days and accumulates to 1.2 x 10{sup 6} Bq cm{sup -3} after a full year of operation. The daily utilization of the MLC leads to buildup of activity with time. The overall activity continues to increase due to {sup 179}Ta with a half-life of 1.82 yr and thus require prolonged storage for activity cooling. The H*(10) near the patient side of the tungsten block is about 100 {mu}Sv/h and is 27 times higher at the upstream side of the block. This would lead to an accumulated dose for therapists in a year that may exceed occupational maximum permissible dose (50 mSv/yr). The value of H*(10) at the upstream surface of the tungsten block is about 220 times higher than that of the brass. Conclusions: MLC is an efficient way for beam shaping and overall cost reduction device in proton therapy. However, based on this study, tungsten seems to be not an optimal material for MLC in proton beam therapy. Usage of tungsten MLC in clinic may create unnecessary risks associated with the secondary neutrons and induced radioactivity for patients and staff depending on the patient load. A careful selection of material for manufacturing of an optimal MLC for proton therapy is thus desired.

  6. Comparison of Bond Scission Sequence of Methanol on Tungsten Monocarbide and Pt-Modified Tungsten Monocarbide

    SciTech Connect (OSTI)

    Liu, P.; Stottlemyer, A.L.; Chen, J.G.

    2010-09-14T23:59:59.000Z

    The ability to control the bond scission sequence of O-H, C-H, and C-O bonds is of critical importance in the effective utilization of oxygenate molecules, such as in reforming reactions and in alcohol fuel cells. In the current study, we use methanol as a probe molecule to demonstrate the possibility to control the decomposition pathways by supporting monolayer coverage of Pt on a tungsten monocarbide (WC) surface. Density functional theory (DFT) results reveal that on the WC and Pt/WC surfaces CH{sub 3}OH decomposes via O-H bond scission to form the methoxy (*CH{sub 3} O) intermediate. The subsequent decomposition of methoxy on the WC surface occurs through the C-O bond scission to form *CH{sub 3}, which reacts with surface *H to produce CH{sub 4}. In contrast, the decomposition of methoxy on the Pt/WC surface favors the C-H bond scission to produce *CH{sub 2} O, which prevents the formation of the *CH{sub 3} species and leads to the formation of a *CO intermediate through subsequent deprotonation steps. The DFT predictions are validated using temperature programmed desorption to quantify the gas-phase product yields and high resolution electron energy loss spectroscopy to determine the surface intermediates from methanol decomposition on Pt, WC, and Pt/WC surfaces.

  7. Process for removing halogenated aliphatic and aromatic compounds from petroleum products. [Polychlorinated biphenyls; methylene chloride; perchloroethylene; trichlorofluoroethane; trichloroethylene; chlorobenzene

    DOE Patents [OSTI]

    Googin, J.M.; Napier, J.M.; Travaglini, M.A.

    1982-03-31T23:59:59.000Z

    A process for removing halogenated aliphatic and aromatic compounds, e.g., polychlorinated biphenyls, from petroleum products by solvent extraction. The halogenated aliphatic and aromatic compounds are extracted from a petroleum product into a polar solvent by contracting the petroleum product with the polar solvent. The polar solvent is characterized by a high solubility for the extracted halogenated aliphatic and aromatic compounds, a low solubility for the petroleum product and considerable solvent power for polyhydroxy compound. The preferred polar solvent is dimethylformamide. A miscible polyhydroxy compound, such as, water, is added to the polar extraction solvent to increase the polarity of the polar extraction solvent. The halogenated aliphatic and aromatic compounds are extracted from the highly-polarized mixture of polyhydroxy compound and polar extraction solvent into a low polar or nonpolar solvent by contacting the polyhydroxy compound-polar solvent mixture with the low polar or nonpolar solvent. The halogenated aliphatic and aromatic compounds in the low polar or nonpolar solvent by physical means, e.g., vacuum evaporation. The polar and nonpolar solvents are recovered for recycling. The process can easily be designed for continuous operation. Advantages of the process include that the polar solvent and a major portion of the nonpolar solvent can be recycled, the petroleum products are reclaimable and the cost for disposing of waste containing polychlorinated biphenyls is significantly reduced. 2 tables.

  8. In vivo interactions between tungsten microneedles and peripheral nerves

    E-Print Network [OSTI]

    Pier Nicola Sergi; Winnie Jensen; Silvestro Micera; Ken Yoshida

    2013-08-02T23:59:59.000Z

    Tungsten microneedles are currently used to insert neural electrodes into living peripheral nerves. However, the biomechanics underlying these procedures is not yet well characterized. For this reason, the aim of this work was to model the interactions between these microneedles and living peripheral nerves. A simple mathematical framework was especially provided to model both compression of the external layer of the nerve (epineurium) and the interactions resulting from penetration of the main shaft of the microneedle inside the living nerves. The instantaneous Young's modulus, compression force, the work needed to pierce the tissue, puncturing pressure, and the dynamic friction coefficient between the tungsten microneedles and living nerves were quantified starting from acute experiments, aiming to reproduce the physical environment of real implantations. Indeed, a better knowledge of the interactions between microneedles and peripheral nerves may be useful to improve the effectiveness of these insertion techniques, and could represent a key factor for designing robot-assisted procedures tailored for peripheral nerve insertion.

  9. Development of positron annihilation spectroscopy for characterizing neutron irradiated tungsten

    SciTech Connect (OSTI)

    C.N. Taylor; M. Shimada; D.W. Akers; M.W. Drigert; B.J. Merrill; Y. Hatano

    2013-05-01T23:59:59.000Z

    Tungsten samples (6 mm diameter, 0.2 mm thick) were irradiated to 0.025 and 0.3 dpa with neutrons in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. Samples were then exposed to deuterium plasma in the tritium plasma experiment (TPE) at 100, 200 and 500ºC to a total fluence of 1 x 1026 m-2. Nuclear reaction analysis (NRA) and Doppler broadening positron annihilation spectroscopy (DB-PAS) were performed at various stages to characterize damage and retention. We present the first known results of neutron damaged tungsten characterized by DB-PAS in order to study defect concentration. Two positron sources, 22Na and 68Ge, probe ~58 µm and through the entire 200 µm thick samples, respectively. DB-PAS results reveal clear differences between the various irradiated samples. These results, and the calibration of DB-PAS to NRA data are presented.

  10. Studies on nickel-tungsten oxide thin films

    SciTech Connect (OSTI)

    Usha, K. S. [Department of Physics, Alagappa University, Karaikudi - 630 004 (India); Sivakumar, R., E-mail: krsivakumar1979@yahoo.com [Directorate of Distance Education, Alagappa University, Karaikudi - 630 004 (India); Sanjeeviraja, C. [Department of Physics, Alagappa Chettiar College of Engineering and Technology, Karaikudi - 630 004 (India)

    2014-10-15T23:59:59.000Z

    Nickel-Tungsten oxide (95:5) thin films were prepared by rf sputtering at 200W rf power with various substrate temperatures. X-ray diffraction study reveals the amorphous nature of films. The substrate temperature induced decrease in energy band gap with a maximum transmittance of 71%1 was observed. The Micro-Raman study shows broad peaks at 560 cm{sup ?1} and 1100 cm{sup ?1} correspond to Ni-O vibration and the peak at 860 cm{sup ?1} can be assigned to the vibration of W-O-W bond. Photoluminescence spectra show two peaks centered on 420 nm and 485 nm corresponding to the band edge emission and vacancies created due to the addition of tungsten, respectively.

  11. Gas-tungsten arc welding of aluminum alloys

    DOE Patents [OSTI]

    Frye, Lowell D. (Kingston, TN)

    1984-01-01T23:59:59.000Z

    A gas-tungsten arc welding method for joining together structures formed of aluminum alloy with these structures disposed contiguously to a heat-damagable substrate of a metal dissimilar to the aluminum alloy. The method of the present invention is practiced by diamond machining the fay surfaces of the aluminum alloy structures to provide a mirror finish thereon having a surface roughness in the order of about one microinch. The fay surfaces are aligned and heated sufficiently by the tungsten electrode to fuse the aluminum alloy contiguous to the fay surfaces to effect the weld joint. The heat input used to provide an oxide-free weld is significantly less than that required if the fay surfaces were prepared by using conventional chemical and mechanical practices.

  12. Gas-tungsten arc welding of aluminum alloys

    DOE Patents [OSTI]

    Frye, L.D.

    1982-03-25T23:59:59.000Z

    The present invention is directed to a gas-tungsten arc welding method for joining together structures formed of aluminum alloy with these structures disposed contiguously to a heat-damagable substrate of a metal dissimilar to the aluminum alloy. The method of the present invention is practiced by diamond machining the fay surfaces of the aluminum alloy structures to profice a mirror finish thereon having a surface roughness in the order of about one microinch. The fay surface are aligned and heated sufficiently by the tungsten electrode to fuse the aluminum alloy continguous to the fay surfaces to effect the weld joint. The heat input used to provide an oxide-free weld is significantly less than that required if the fay surfaces were prepared by using conventional chemical and mechanical practices.

  13. Gas-tungsten arc welding of aluminum alloys

    SciTech Connect (OSTI)

    Frye, L.D.

    1984-11-20T23:59:59.000Z

    A gas-tungsten arc welding method for joining together structures formed of aluminum alloy with these structures disposed contiguously to a heat-damagable substrate of a metal dissimilar to the aluminum alloy. The method of the present invention is practiced by diamond machining the fay surfaces of the aluminum alloy structures to provide a mirror finish thereon having a surface roughness in the order of about one micro-inch. The fay surfaces are aligned and heated sufficiently by the tungsten electrode to fuse the aluminum alloy contiguous to the fay surfaces to effect the weld joint. The heat input used to provide an oxide-free weld is significantly less than that required if the fay surfaces were prepared by using conventional chemical and mechanical practices.

  14. Thermal-treatment effect on the photoluminescence and gas-sensing properties of tungsten oxide nanowires

    SciTech Connect (OSTI)

    Sun, Shibin [College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061, Shandong (China)] [College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061, Shandong (China); Chang, Xueting [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100, Shandong (China)] [Institute of Materials Science and Engineering, Ocean University of China, Qingdao 266100, Shandong (China); Li, Zhenjiang, E-mail: zjli126@126.com [College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061, Shandong (China)] [College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061, Shandong (China)

    2010-09-15T23:59:59.000Z

    Single-crystalline non-stoichiometric tungsten oxide nanowires were initially prepared using a simple solvothermal method. High resolution transmission electron microscopy (HRTEM) investigations indicate that the tungsten oxide nanowires exhibit various crystal defects, including stacking faults, dislocations, and vacancies. A possible defect-induced mechanism was proposed to account for the temperature-dependent morphological evolution of the tungsten oxide nanowires under thermal processing. Due to the high specific surface areas and non-stoichiometric crystal structure, the original tungsten oxide nanowires were highly sensitive to ppm level ethanol at room temperature. Thermal treatment under dry air condition was found to deteriorate the selectivity of room-temperature tungsten oxide sensors, and 400 {sup o}C may be considered as the top temperature limit in sensor applications for the solvothermally-prepared nanowires. The photoluminescence (PL) characteristics of tungsten oxide nanowires were also strongly influenced by thermal treatment.

  15. Tungsten spectroscopy relevant to the diagnostics development of ITER divertor plasmas

    SciTech Connect (OSTI)

    Clementson, J; Beiersdorfer, P; Magee, E W; McLean, H S; Wood, R D

    2009-12-01T23:59:59.000Z

    The ITER tokamak will have tungsten divertor tiles and, consequently, the divertor plasmas are expected to contain tungsten ions. The spectral emission from these ions can serve to diagnose the divertor for plasma parameters such as tungsten concentrations, densities, ion and electron temperatures, and flow velocities. The ITER divertor plasmas will likely have densities around 10{sup 14-15} cm{sup -3} and temperatures below 150 eV. These conditions are similar to the plasmas at the Sustained Spheromak Physics Experiment (SSPX) in Livermore. To simulate ITER divertor plasmas, a tungsten impurity was introduced into the SSPX spheromak by prefilling it with tungsten hexacarbonyl prior to the usual hydrogen gas injection and initiation of the plasma discharge. The possibility of using the emission from low charge state tungsten ions to diagnose tokamak divertor plasmas has been investigated using a high-resolution extreme ultraviolet spectrometer.

  16. Photoionization of the valence shells of the neutral tungsten atom

    E-Print Network [OSTI]

    Ballance, Connor P

    2015-01-01T23:59:59.000Z

    Results from large-scale theoretical cross section calculations for the total photoionization of the 4f, 5s, 5p and 6s orbitals of the neutral tungsten atom using the Dirac Coulomb R-matrix approximation (DARC: Dirac-Atomic R-matrix codes) are presented. Comparisons are made with previous theoretical methods and prior experimental measurements. In previous experiments a time-resolved dual laser approach was employed for the photo-absorption of metal vapours and photo-absorption measurements on tungsten in a solid, using synchrotron radiation. The lowest ground state level of neutral tungsten is $\\rm 5p^6 5d^4 6s^2 \\; {^5}D_{\\it J}$, with $\\it J$=0, and requires only a single dipole matrix for photoionization. To make a meaningful comparison with existing experimental measurements, we statistically average the large-scale theoretical PI cross sections from the levels associated with the ground state $\\rm 5p^6 5d^4 6s^2 \\; {^5}D_{\\it J}[{\\it J}=0,1,2,3,4]$ levels and the $\\rm 5d^56s \\; ^7S_3$ excited metastable...

  17. Synthesis, Crystal Structure, and Elastic Properties of Novel Tungsten Nitrides

    SciTech Connect (OSTI)

    Wang, Shanmin; Yu, Xiaohui; Lin, Zhijun; Zhang, Ruifeng; He, Duanwei; Qin, Jiaqian; Zhu, Jinlong; Han, Jiantao; Wang, Lin; Mao, Ho-kwang; Zhang, Jianzhong; Zhao, Yusheng (UNLV); (Ehime U); (CIW); (Sichuan U.); (LANL)

    2012-12-13T23:59:59.000Z

    Among transition metal nitrides, tungsten nitrides possess unique and/or superior chemical, mechanical, and thermal properties. Preparation of these nitrides, however, is challenging because the incorporation of nitrogen into tungsten lattice is thermodynamically unfavorable at atmospheric pressure. To date, most materials in the W-N system are in the form of thin films produced by nonequilibrium processes and are often poorly crystallized, which severely limits their use in diverse technological applications. Here we report synthesis of tungsten nitrides through new approaches involving solid-state ion exchange and nitrogen degassing under pressure. We unveil a number of novel nitrides including hexagonal and rhombohedral W{sub 2}N{sub 3}. The final products are phase-pure and well-crystallized in bulk forms. For hexagonal W{sub 2}N{sub 3}, hexagonal WN, and cubic W3N4, they exhibit elastic properties rivaling or even exceeding cubic-BN. All four nitrides are prepared at a moderate pressure of 5 GPa, the lowest among high-pressure synthesis of transition metal nitrides, making it practically feasible for massive and industrial-scale production.

  18. Process for the solvent extraction for the radiolysis and dehalogenation of halogenated organic compounds in soils, sludges, sediments and slurries

    DOE Patents [OSTI]

    Golden, Jeffry

    2007-02-13T23:59:59.000Z

    A process of extracting halogenated organic compounds, and particularly PCBs, from soil, sediment, slurry, sludge and dehalogenating the compounds contacts a contaminated soil sample with an extraction medium of a mixture of an alkane and a water miscible alcohol. The organic compounds dissolve in the extraction medium which is separated from the soil by passing water upwardly through the soil. The extraction medium floats to the surface of the water and is separated. Thereafter, the extraction medium containing the halogenated organic contaminants is subjected to ionizing radiation to radiolytically dehalogenate the compounds.

  19. Process for the solvent extraction for the radiolysis and dehalogenation of halogenated organic compounds in soils, sludges, sediments and slurries

    DOE Patents [OSTI]

    Mincher, Bruce J. (3705 Creekside Dr., Idaho Falls, ID 83404); Curry, Randy Dale (1104 Merrill Ct., Columbia, MO 65203); Clevenger, Thomas E. (2512 Bluff Blvd., Columbia, MO 65201); Golden, Jeffry (12612 Cedarbrook La., Laurel, MD 20708)

    2000-01-01T23:59:59.000Z

    A process of extracting halogenated organic compounds, and particularly PCBs, from soil, sediment, slurry, sludge and dehalogenating the compounds contacting a contaminated soil sample with an extraction medium of a mixture of an alkane and a water miscible alcohol. The organic compounds dissolve in the extraction medium which is separated from the soil by passing water upwardly through the soil. The extraction medium floats to the surface of the water and is separated. Thereafter, the extraction medium containing the halogenated organic contaminants is subjected to ionizing radiation to radiolytically dehalogenate the compounds.

  20. Process for the solvent extraction for the radiolysis and dehalogenation of halogenated organic compounds in soils, sludges, sediments and slurries

    DOE Patents [OSTI]

    Mincher, Bruce J.; Curry, Randy Dale; Clevenger, Thomas E.; Golden, Jeffry

    2003-05-27T23:59:59.000Z

    A process of extracting halogenated organic compounds, and particularly PCBs, from soil, sediment, slurry, sludge and dehalogenating the compounds contacts a contaminated soil sample with an extraction medium of a mixture of an alkane and a water miscible alcohol. The organic compounds dissolve in the extraction medium which is separated from the soil by passing water upwardly through the soil. The extraction medium floats to the surface of the water and is separated. Thereafter, the extraction medium containing the halogenated organic contaminants is subjected to ionizing radiation to radiolytically dehalogenate the compounds.

  1. Systematic studies of the nucleation and growth of ultrananocrystalline diamond films on silicon substrates coated with a tungsten layer

    SciTech Connect (OSTI)

    Chu, Yueh-Chieh; Jiang, Gerald [Institute of Microelectronics, No.1, University Road, Tainan 701, Taiwan (China); Tu, Chia-Hao [Institute of Nanotechnology and Microsystems Engineering, No.1, University Road, Tainan 701, Taiwan (China); Department of Materials Science and Engineering, National Cheng Kung University, No.1, University Road, Tainan 701, Taiwan (China); Chang Chi [Institute of Nanotechnology and Microsystems Engineering, No.1, University Road, Tainan 701, Taiwan (China); Liu, Chuan-pu; Ting, Jyh-Ming [Department of Materials Science and Engineering, National Cheng Kung University, No.1, University Road, Tainan 701, Taiwan (China); Lee, Hsin-Li [Industrial Technology Research Institute - South, Tainan 701, Taiwan (China); Tzeng, Yonhua [Institute of Microelectronics, No.1, University Road, Tainan 701, Taiwan (China); Advanced Optoelectronics Technology Center, No.1, University Road, Tainan 701, Taiwan (China); Auciello, Orlando [Argonne National Laboratory, Materials Science Division, 9700 S. Cass Avenue, Argonne, Illinois 60439 (United States)

    2012-06-15T23:59:59.000Z

    We report on effects of a tungsten layer deposited on silicon surface on the effectiveness for diamond nanoparticles to be seeded for the deposition of ultrananocrystalline diamond (UNCD). Rough tungsten surface and electrostatic forces between nanodiamond seeds and the tungsten surface layer help to improve the adhesion of nanodiamond seeds on the tungsten surface. The seeding density on tungsten coated silicon thus increases. Tungsten carbide is formed by reactions of the tungsten layer with carbon containing plasma species. It provides favorable (001) crystal planes for the nucleation of (111) crystal planes by Microwave Plasma Enhanced Chemical Vapor Deposition (MPECVD) in argon diluted methane plasma and further improves the density of diamond seeds/nuclei. UNCD films grown at different gas pressures on tungsten coated silicon which is pre-seeded by nanodiamond along with heteroepitaxially nucleated diamond nuclei were characterized by Raman scattering, field emission-scanning electron microscopy, and high resolution-transmission electron microscopy.

  2. Nmr Study of Thiocarbonyl Derivatives of Fe and Mn were made with solutions of the tungsten and molybdenum species

    E-Print Network [OSTI]

    Bodner, George M.

    Nmr Study of Thiocarbonyl Derivatives of Fe and Mn were made with solutions of the tungsten.g.. the tungsten ion readily oxidizes in aqueous acid [A. Samotus and B. Kosowicz-Czajkowska, Rocz. Chem., 45, 1623

  3. Comparison of QM-Only and QM/MM Models for the Mechanism of Tungsten-Dependent Acetylene Hydratase

    E-Print Network [OSTI]

    Liao, Rongzhen

    Comparison of QM-Only and QM/MM Models for the Mechanism of Tungsten-Dependent Acetylene Hydratase study on the formation of vinyl alcohol in the catalytic cycle of tungsten-dependent acetylene hydratase

  4. Modelling of Melt Damage of Tungsten Armour under Multiple Transients Expected in ITER and Validations Against JET-ILW Experiments

    E-Print Network [OSTI]

    Modelling of Melt Damage of Tungsten Armour under Multiple Transients Expected in ITER and Validations Against JET-ILW Experiments

  5. Bulk Tungsten in the JET Divertor: Potential Influence of the Exhaustion of Ductility and Grain Growth on the Lifetime

    E-Print Network [OSTI]

    Bulk Tungsten in the JET Divertor: Potential Influence of the Exhaustion of Ductility and Grain Growth on the Lifetime

  6. The Structure of the Tungsten Coatings Deposited by Combined Magnetron Sputtering and Ion Implantation for Nuclear Fusion Applications

    E-Print Network [OSTI]

    The Structure of the Tungsten Coatings Deposited by Combined Magnetron Sputtering and Ion Implantation for Nuclear Fusion Applications

  7. 3-D Finite Element Electromagnetic and Stress Analyses of the JET LB-SRP Divertor Element (Tungsten Lamella Design)

    E-Print Network [OSTI]

    3-D Finite Element Electromagnetic and Stress Analyses of the JET LB-SRP Divertor Element (Tungsten Lamella Design)

  8. Theoretical Description of Heavy Impurity Transport and its Application to the Modelling of Tungsten in JET and ASDEX Upgrade

    E-Print Network [OSTI]

    Theoretical Description of Heavy Impurity Transport and its Application to the Modelling of Tungsten in JET and ASDEX Upgrade

  9. Shower characteristics of particles with momenta from up to 100 GeV in the CALICE Scintillator-Tungsten HCAL

    E-Print Network [OSTI]

    Klempt W

    2015-01-01T23:59:59.000Z

    Shower characteristics of particles with momenta from up to 100 GeV in the CALICE Scintillator-Tungsten HCAL

  10. Clamping of Solid Tungsten Components for the Bulk W Divertor Row in JET – Precautionary Design for a Brittle Material

    E-Print Network [OSTI]

    Clamping of Solid Tungsten Components for the Bulk W Divertor Row in JET – Precautionary Design for a Brittle Material

  11. Soft X-Ray Tomographic Reconstruction of JET ILW Plasmas with Tungsten Impurity and Different Spectral Response of Detectors

    E-Print Network [OSTI]

    Soft X-Ray Tomographic Reconstruction of JET ILW Plasmas with Tungsten Impurity and Different Spectral Response of Detectors

  12. Power Handling of the Bulk Tungsten Divertor Row at JET: First Measurements and Comparison to the GTM Thermal Model

    E-Print Network [OSTI]

    Power Handling of the Bulk Tungsten Divertor Row at JET: First Measurements and Comparison to the GTM Thermal Model

  13. Positron-production Experiment In Tungsten Crystal Using 4 And 8-gev Channeling Electrons At The Kekb Injector Linac

    E-Print Network [OSTI]

    Suwada, T; Chehab, R; Enomoto, A; Furukawa, K; Kakihara, K; Kamitani, T; Ogawa, Y; Ohsawa, S; Okuno, H; Oogoe, T; Fujita, T; Umemori, K; Yoshida, K; Ababiy, V; Potylitsin, A P; Vnukov, I E; Hamatsu, R; Sasahara, K

    2002-01-01T23:59:59.000Z

    Positron-production Experiment In Tungsten Crystal Using 4 And 8-gev Channeling Electrons At The Kekb Injector Linac

  14. Positron-production Experiment By 8-gev Channeling Electrons In Crystal Tungsten At The Kekb Injector Linac

    E-Print Network [OSTI]

    Suwada, T

    2001-01-01T23:59:59.000Z

    Positron-production Experiment By 8-gev Channeling Electrons In Crystal Tungsten At The Kekb Injector Linac

  15. Introduction The Fiber-Lite MI-150 is a 150 Watt quartz halogen fiber optic illuminator designed for general microscopy

    E-Print Network [OSTI]

    Kleinfeld, David

    Introduction ® The Fiber-Lite MI-150 is a 150 Watt quartz halogen fiber optic illuminator designed for general microscopy use. When used with specialty fiber optic cables the MI-150 illuminator can also Illuminator from the carton and retain the manual and any additional documents. ! Remove the fiber optic cable

  16. Hydrogen interaction with point defects in tungsten K. Heinola, T. Ahlgren, K. Nordlund, and J. Keinonen

    E-Print Network [OSTI]

    Nordlund, Kai

    Hydrogen interaction with point defects in tungsten K. Heinola, T. Ahlgren, K. Nordlund, and J-principles calculations were used in determining the binding and trapping properties of hydrogen to point defects in tungsten. Hydrogen zero-point vibrations were taken into account. It was concluded that the monovacancy can

  17. Hot cracking in tungsten inert gas welding of magnesium alloy AZ91D

    E-Print Network [OSTI]

    Zhou, Wei

    Hot cracking in tungsten inert gas welding of magnesium alloy AZ91D W. Zhou*, T. Z. Long and C. K of the plates were produced using tungsten inert gas (TIG) welding method. The TIG arc was also used to deposit welding beads on some of the thin plates. No cracking was found in the butt joints. However, hot cracking

  18. Review on the EFDA programme on tungsten materials technology and science M. Rieth a,

    E-Print Network [OSTI]

    Nordlund, Kai

    Review on the EFDA programme on tungsten materials technology and science M. Rieth a, , J design studies for helium cooled divertors utilize tungsten materials and alloys, mainly due structural as well as armor materials in combination with the necessary production and fab- rication

  19. G.M. Wright, VLT Highlight, March 28, 2012 Growth of tungsten nano-tendrils in

    E-Print Network [OSTI]

    1 G.M. Wright, VLT Highlight, March 28, 2012 Growth of tungsten nano-tendrils in the Alcator C morphology of a tungsten divertor modify into fuzz under Helium bombardment in ITER and reactors?! · Linear fragile nano-tendrils! · Increased unipolar arcing! · Likely higher net erosion and W dust production

  20. Dynamics of femtosecond laser produced tungsten nanoparticle plumes S. S. Harilal,1

    E-Print Network [OSTI]

    Harilal, S. S.

    Dynamics of femtosecond laser produced tungsten nanoparticle plumes S. S. Harilal,1 N. Farid,1,2 A tungsten nanoparticle plumes in vacuum. Fast gated images showed distinct two components expansion features.1063/1.4833564] I. INTRODUCTION Nanoparticle production and application research is an area of significant

  1. X-ray diffraction study of the static strength of tungsten to 69 GPa Duanwei He* and Thomas S. Duffy

    E-Print Network [OSTI]

    Duffy, Thomas S.

    X-ray diffraction study of the static strength of tungsten to 69 GPa Duanwei He* and Thomas S of tungsten was determined under static high pressures to 69 GPa using x-ray diffraction techniques strength of tungsten increases with compression, reaching a value of 5.3 GPa at the highest pressure

  2. TUNGSTEN AND HAFNIUM DISTRIBUTION IN CALCIUM-ALUMINUM INCLUSIONS (CAIs) FROM ALLENDE AND EFREMOVKA. M. Humayun1

    E-Print Network [OSTI]

    Grossman, Lawrence

    TUNGSTEN AND HAFNIUM DISTRIBUTION IN CALCIUM-ALUMINUM INCLUSIONS (CAIs) FROM ALLENDE AND EFREMOVKA with, or even earlier than, metal from CAIs and chondrules [3]. Tungsten isotope compositions represent veins [5]. Tungsten mobility is cause for concern, but is not sufficient evidence against the Kleine et

  3. Z .Surface and Coatings Technology 130 2000 164 172 Production of high-density Ni-bonded tungsten carbide

    E-Print Network [OSTI]

    Ghoniem, Nasr M.

    Z .Surface and Coatings Technology 130 2000 164 172 Production of high-density Ni-bonded tungsten spraying; Nickel; Tungsten carbide 1. Introduction 1.1. General Since the mid-1990s, the market share of cemented Z .carbides has surpassed that of high-speed steels HSS , Z .with tungsten carbide WC having 50

  4. By Earle B. Amey Tungsten's unique high-temperature properties are beneficial The Office of the United States Trade Representative

    E-Print Network [OSTI]

    of tungsten ore concentrates and products with that of 1994. Demand generally increased in the cemented from products under these tariffs. during 1995. During 1995, prices for tungsten concentrates, which had built from 1985). Major Domestic production data for tungsten were developed by the liquidation of both

  5. By Earle B. Amey Tungsten's unique high-temperature in Metal Bulletin (London). ferrotungsten, carbide powder blends, and

    E-Print Network [OSTI]

    of a stronger tungsten market, at certain forms of waste and scrap. production of numerous end-use items of the U.S. economy influenced the overall increase in demand for tungsten products during 1994. The antidumping tariffs on imports of tungsten ore concentrates and products from China, initially imposed

  6. ENHANCEMENT OF THE POSITRON INTENSITY BY A TUNGSTEN SINGLE-CRYSTAL TARGET AT THE KEKB INJECTOR LINAC

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    by these stimulating results, we proceeded to systematic studies on the positron-production efficiencies with tungstenENHANCEMENT OF THE POSITRON INTENSITY BY A TUNGSTEN SINGLE-CRYSTAL TARGET AT THE KEKB INJECTOR, Russia R. Chehab, IPNL, IN2P3-CNRS, Universite Claude Bernald 1, France Abstract A new tungsten single

  7. Dynamics of femtosecond laser produced tungsten nanoparticle plumes

    SciTech Connect (OSTI)

    Harilal, S. S.; Hassanein, A. [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)] [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Farid, N. [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States) [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); School of Physics and Optical Engineering, Dalian University of Technology, Dalian 116024 (China); Kozhevin, V. M. [Ioffe Physics Technical Institute, Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation)] [Ioffe Physics Technical Institute, Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation)

    2013-11-28T23:59:59.000Z

    We investigated the expansion features of femtosecond laser generated tungsten nanoparticle plumes in vacuum. Fast gated images showed distinct two components expansion features, viz., plasma and nanoparticle plumes, separated by time of appearance. The persistence of plasma and nanoparticle plumes are ?500 ns and ?100 ?s, respectively, and propagating with velocities differed by 25 times. The estimated temperature of the nanoparticles showed a decreasing trend with increasing time and space. Compared to low-Z materials (e.g., Si), ultrafast laser ablation of high-Z materials like W provides significantly higher nanoparticle yield. A comparison between the nanoparticle plumes generated by W and Si is also discussed along with other metals.

  8. Electrodeposited tungsten-nickel-boron: A replacement for hexavalent chromium

    SciTech Connect (OSTI)

    Steffani, C.; Meltzer, M.

    1995-04-01T23:59:59.000Z

    Chromium, deposited from acidic solutions of its hexavalent ion, has been the rule for wear resistant, corrosion resistant coatings for many years. Although chromium coatings are durable, the plating process generates air emissions, effluent rinse waters, and process solutions that are toxic, suspected carcinogens, and a risk to human health and the environment. Tungsten-nickel-boron (W-Ni-B) alloy deposition is a potential substitute for hexavalent chrome. It has excellent wear, corrosion, and mechanical properties and also may be less of an environmental risk. This study examines the electroplating process and deposit properties of W-Ni-B and compares them with those of hexavalent chrome.

  9. Detection of the Natural Alpha Decay of Tungsten

    E-Print Network [OSTI]

    C. Cozzini; G. Angloher; C. Bucci; F. von Feilitzsch; D. Hauff; S. Henry; Th. Jagemann; J. Jochum; H. Kraus; B. Majorovits; V. Mikhailik; J. Ninkovic; F. Petricca; W. Potzel; F. Proebst; Y. Ramachers; W. Rau; M. Razeti; W. Seidel; M. Stark; L. Stodolsky; A. J. B. Tolhurst; W. Westphal; H. Wulandari

    2004-10-26T23:59:59.000Z

    The natural alpha decay of 180W has been unambiguously detected for the first time. The alpha peak is found in a (gamma,beta and neutron)-free background spectrum. This has been achieved by the simultaneous measurement of phonon and light signals with the CRESST cryogenic detectors. A half-life of T1/2 = (1.8 +- 0.2) x 10^18 y and an energy release of Q = (2516.4 +- 1.1 (stat.) +- 1.2 (sys.)) keV have been measured. New limits are also set on the half-lives of the other naturally occurring tungsten isotopes.

  10. Electronic and structural properties of ultrathin tungsten nanowires and nanotubes by density functional theory calculation

    SciTech Connect (OSTI)

    Sun, Shih-Jye [Department of Applied Physics, National University of Kaohsiung, Kaohsiung 811, Taiwan (China); Lin, Ken-Huang; Li, Jia-Yun [Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Ju, Shin-Pon, E-mail: jushin-pon@mail.nsysu.edu.tw [Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China)

    2014-10-07T23:59:59.000Z

    The simulated annealing basin-hopping method incorporating the penalty function was used to predict the lowest-energy structures for ultrathin tungsten nanowires and nanotubes of different sizes. These predicted structures indicate that tungsten one-dimensional structures at this small scale do not possess B.C.C. configuration as in bulk tungsten material. In order to analyze the relationship between multi-shell geometries and electronic transfer, the electronic and structural properties of tungsten wires and tubes including partial density of state and band structures which were determined and analyzed by quantum chemistry calculations. In addition, in order to understand the application feasibility of these nanowires and tubes on nano-devices such as field emitters or chemical catalysts, the electronic stability of these ultrathin tungsten nanowires was also investigated by density functional theory calculations.

  11. Atomic data of tungsten for current and future uses in fusion and plasma science

    SciTech Connect (OSTI)

    Clementson, J.; Beiersdorfer, P. [Physics Division, Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94551 (United States); Lennartsson, T. [Lund Observatory, Lund University, P.O. Box 43, SE-221 00 Lund (Sweden)

    2013-04-19T23:59:59.000Z

    Atomic physics has played an important role throughout the history of experimental plasma physics. For example, accurate knowledge of atomic properties has been crucial for understanding the plasma energy balance and for diagnostic development. With the shift in magnetic fusion research toward high-temperature burning plasmas like those expected to be produced in the ITER tokamak, the atomic physics of tungsten has become important. Tungsten will be a constituent of ITER plasmas because of its use as a plasma-facing material able to withstand high heat loads with lower tritium retention than other possible materials. Already, ITER diagnostics are being developed based on using tungsten radiation. In particular, the ITER Core Imaging X-ray Spectrometer (CIXS), which is designed to measure the core ion temperature and bulk plasma motion, is being based on the x-ray emission of neonlike tungsten ions (W{sup 64+}). In addition, tungsten emission will at ITER be measured by extreme ultraviolet (EUV) and optical spectrometers to determine its concentration in the plasma and to assess power loss and tungsten sputtering rates. On present-day tokamaks tungsten measurements are therefore being performed in preparation of ITER. Tungsten has very complex spectra and most are still unknown. The WOLFRAM project at Livermore aims to produce data for tungsten in various spectral bands: Lshell x-ray emission for CIXS development, soft x-ray and EUV M- and N-shell tungsten emission for understanding the edge radiation from ITER plasmas as well as from contemporary tokamaks, and O-shell emission for developing spectral diagnostics of the ITER divertor.

  12. In situ thermally enhanced biodegradation of petroleum fuel hydrocarbons and halogenated organic solvents

    DOE Patents [OSTI]

    Taylor, Robert T. (Livermore, CA); Jackson, Kenneth J. (San Leandro, CA); Duba, Alfred G. (Livermore, CA); Chen, Ching-I (Danville, CA)

    1998-01-01T23:59:59.000Z

    An in situ thermally enhanced microbial remediation strategy and a method for the biodegradation of toxic petroleum fuel hydrocarbon and halogenated organic solvent contaminants. The method utilizes nonpathogenic, thermophilic bacteria for the thermal biodegradation of toxic and carcinogenic contaminants, such as benzene, toluene, ethylbenzene and xylenes, from fuel leaks and the chlorinated ethenes, such as trichloroethylene, chlorinated ethanes, such as 1,1,1-trichloroethane, and chlorinated methanes, such as chloroform, from past solvent cleaning practices. The method relies on and takes advantage of the pre-existing heated conditions and the array of delivery/recovery wells that are created and in place following primary subsurface contaminant volatilization efforts via thermal approaches, such as dynamic underground steam-electrical heating.

  13. In situ thermally enhanced biodegradation of petroleum fuel hydrocarbons and halogenated organic solvents

    DOE Patents [OSTI]

    Taylor, R.T.; Jackson, K.J.; Duba, A.G.; Chen, C.I.

    1998-05-19T23:59:59.000Z

    An in situ thermally enhanced microbial remediation strategy and a method for the biodegradation of toxic petroleum fuel hydrocarbon and halogenated organic solvent contaminants are described. The method utilizes nonpathogenic, thermophilic bacteria for the thermal biodegradation of toxic and carcinogenic contaminants, such as benzene, toluene, ethylbenzene and xylenes, from fuel leaks and the chlorinated ethenes, such as trichloroethylene, chlorinated ethanes, such as 1,1,1-trichloroethane, and chlorinated methanes, such as chloroform, from past solvent cleaning practices. The method relies on and takes advantage of the pre-existing heated conditions and the array of delivery/recovery wells that are created and in place following primary subsurface contaminant volatilization efforts via thermal approaches, such as dynamic underground steam-electrical heating. 21 figs.

  14. Chromatic instabilities in cesium-doped tungsten bronze nanoparticles

    SciTech Connect (OSTI)

    Adachi, Kenji, E-mail: kenji-adachi@ni.smm.co.jp; Ota, Yosuke; Tanaka, Hiroyuki; Okada, Mika; Oshimura, Nobumitsu; Tofuku, Atsushi [Ichikawa Research Laboratories, Sumitomo Metal Mining Co., Ltd., Ichikawa 272-8588 (Japan)

    2013-11-21T23:59:59.000Z

    Nanoparticles of alkali-doped tungsten bronzes are an excellent near-infrared shielding material, but exhibit slight chromatic instabilities typically upon applications of strong ultra-violet light or heating in humid environment, which acts detrimentally to long-life commercial applications. Origin of the chromatic instabilities in cesium-doped tungsten bronze has been investigated, and it has been found that the coloration and bleaching processes comprised electronic exchanges which accelerate or depress the polaron excitation and the localized surface plasmon resonance. Coloration on UV illumination is evidenced by electron diffraction as due to the formation of H{sub x}WO{sub 3}, which is considered to take place in the surface Cs-deficient WO{sub 3} region via the double charge injection mechanism. On the other hand, bleaching on heating in air and in humid environment is shown to accompany the extraction of Cs and electrons from Cs{sub 0.33}WO{sub 3} by X-ray photoelectron spectroscopy and X-ray diffraction analysis and is concluded to be an oxidation of Cs{sub 0.33}WO{sub 3} on the particle surface.

  15. Characterization of tungsten films and their hydrogen permeability

    SciTech Connect (OSTI)

    Nemani?, Vincenc, E-mail: vincenc.nemanic@ijs.si; Kova?, Janez [Jozef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Lungu, Cristian; Porosnicu, Corneliu [National Institute for Laser, Plasma and Radiation Physics, NILPRP, Magurele, Bucharest 077125 (Romania); Zajec, Bojan [Slovenian National Building and Civil Engineering Institute, Dimi?eva 12, 1000 Ljubljana (Slovenia)

    2014-11-01T23:59:59.000Z

    Prediction of tritium migration and its retention within fusion reactors is uncertain due to a significant role of the structural disorder that is formed on the surface layer after plasma exposure. Tungsten films deposited by any of the suitable methods are always disordered and contain a high density of hydrogen traps. Experiments on such films with hydrogen isotopes present a suitable complementary method, which improves the picture of the hydrogen interaction with fusion relevant materials. The authors report on the morphology, composition, and structure of tungsten films deposited by the thermionic vacuum arc method on highly permeable Eurofer substrates. Subsequently, hydrogen permeation studies through these films were carried out in a wide pressure range from 20 to 1000 mbars at 400?°C. The final value of the permeation coefficient for four samples after 24?h at 400?°C was between P?=?3.2?×?10{sup ?14}?mol?H{sub 2}/(m?s?Pa{sup 0.5}) and P?=?1.1?×?10{sup ?15}?mol H{sub 2}/(m s Pa{sup 0.5}). From the time evolution of the permeation flux, it was shown that diffusivity was responsible for the difference in the steady fluxes, as solubility was roughly the same. This is confirmed by XRD data taken on these samples.

  16. A Glove Box Enclosed Gas-Tungsten Arc Welding System

    SciTech Connect (OSTI)

    Reevr, E, M; Robino, C.V.

    1999-07-01T23:59:59.000Z

    This report describes an inert atmosphere enclosed gas-tungsten arc welding system which has been assembled in support of the MC2730, MC2730A and MC 3500 Radioisotope Thermoelectric Generator (RTG) Enhanced Surveillance Program. One goal of this program is to fabricate welds with microstructures and impurity levels which are similar to production heat source welds previously produced at Los Alamos National Laboratory and the Mound Facility. These welds will subsequently be used for high temperature creep testing as part of the overall component lifetime assessment. In order to maximize the utility of the welding system, means for local control of the arc atmosphere have been incorporated and a wide range of welding environments can easily be evaluated. The gas-tungsten arc welding system used in the assembly is computer controlled, includes two-axis and rotary motion, and can be operated in either continuous or pulsed modes. The system can therefore be used for detailed research studies of welding impurity effects, development of prototype weld schedules, or to mimic a significant range of production-like welding conditions. Fixturing for fabrication of high temperature creep test samples have been designed and constructed, and weld schedules for grip-tab and test welds have been developed. The microstructure of these welds have been evaluated and are consistent with those used during RTG production.

  17. Facile Synthesis of a Tungsten Alkylidyne Catalyst for Alkyne Zachary J. Tonzetich, Yan Choi Lam, Peter Muller, and Richard R. Schrock*

    E-Print Network [OSTI]

    Müller, Peter

    Facile Synthesis of a Tungsten Alkylidyne Catalyst for Alkyne Metathesis Zachary J. Tonzetich, Yan cis double bonds. Tungsten alkylidyne trialkoxide alkyne metathesis catalysts were discovered in 1981 of cleavage of a tungsten-tungsten triple bond upon reaction with an alkyne or nitrile.9 Recent advances

  18. Preparation of dinitrogen, hydrido, and carbonyl complexes of molybdenum and tungsten from higher halides

    SciTech Connect (OSTI)

    Borisov, A.P.; Makhaev, V.D.; Semenenko, K.N.

    1988-01-20T23:59:59.000Z

    The yields, physicochemical properties, and analyses of phosphine complexes of molybdenum and tungsten are shown. The reduction of molydenum pentachloride or tungsten hexachloride with metallic magnesium in THF in the presence of a tertiary organic phosphines in an atmosphere of nitrogen, hydrogen, or carbon monoxide provided a convenient method for the preparation of dinitrogen M(N/sub 2/)/sub 2/L/sub 4/, hydride MH/sub 4/L/sub 4/, or carbonyl M(CO)/sub 6/minus/x/L/sub x/ complexes respectively of molybdenum or tungsten (M = Mo, W; L - tertiary organic phosphine).

  19. Tunable carbon nanotube-tungsten carbide nanoparticles heterostructures by vapor deposition

    SciTech Connect (OSTI)

    Xia, Min; Guo, Hongyan; Ge, Changchun [Institute of Special Ceramics and Powder Metallurgy, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing (China); Institute of Powder Metallurgy and Advanced Ceramics, Southwest Jiaotong University, 111, 1st Section, Northern 2nd Ring Road, Chengdu (China); Yan, Qingzhi, E-mail: qzyan@ustb.edu.cn; Lang, Shaoting [Institute of Special Ceramics and Powder Metallurgy, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing (China)

    2014-05-14T23:59:59.000Z

    A simple, versatile route for the synthesis of carbon nanotube (CNT)-tungsten carbide nanoparticles heterostructures was set up via vapor deposition process. For the first time, amorphous CNTs (?-CNTs) were used to immobilized tungsten carbide nanoparticles. By adjusting the synthesis and annealing temperature, ?-CNTs/amorphous tungsten carbide, ?-CNTs/W{sub 2}C, and CNTs/W{sub 2}C/WC heterostructures were prepared. This approach provides an efficient method to attach other metal carbides and other nanoparticles to carbon nanotubes with tunable properties.

  20. Mechanisms of gas precipitation in plasma-exposed tungsten

    SciTech Connect (OSTI)

    R. D. Kolasinski; D. F. Cowgill; D. C. Donovan; M. Shimada

    2012-05-01T23:59:59.000Z

    Precipitation in subsurface bubbles is a key process that governs how hydrogen isotopes migrate through and become trapped within plasma-exposed tungsten. We describe a continuum-scale model of hydrogen diffusion in plasma-exposed materials that includes the effects of precipitation. The model can account for bubble expansion via dislocation loop punching, using an accurate equation of state to determine the internal pressure. This information is used to predict amount of hydrogen trapped by bubbles, as well as the conditions where the bubbles become saturated. In an effort to validate the underlying assumptions, we compare our results with published positron annihilation and thermal desorption spectroscopy data, as well as our own measurements using the tritium plasma experiment (TPE).

  1. Pico- and nanosecond laser ablation of mixed tungsten / aluminium films

    E-Print Network [OSTI]

    Wisse, M; Steiner, R; Mathys, D; Stumpp, A; Joanny, M; Travere, J M; Meyer, E

    2014-01-01T23:59:59.000Z

    In order to extend the investigation of laser-assisted cleaning of ITER-relevant first mirror materials to the picosecond regime, a commercial laser system delivering 10 picosecond pulses at 355 nm at a frequency of up to 1 MHz has been used to investigate the ablation of mixed aluminium (oxide) / tungsten (oxide) layers deposited on poly- and nanocrystalline molybdenum as well as nanocrystalline rhodium mirrors. Characterization before and after cleaning using scanning electron microscopy (SEM) and spectrophotometry shows heavy dust formation, resulting in a degradation of the reflectivity. Cleaning using a 5 nanosecond pulses at 350 and 532 nm, on the other hand, proved very promising. The structure of the film remnants suggests that in this case buckling was the underlying removal mechanism rather than ablation. Repeated coating and cleaning using nanosecond pulses is demonstrated.

  2. Determination of the electron–phonon coupling constant in tungsten

    SciTech Connect (OSTI)

    Daraszewicz, Szymon L.; Duffy, Dorothy M.; Shluger, Alexander L. [Department of Physics and Astronomy, London Centre for Nanotechnology, University College London, Gower Street, WC1E 6BT London (United Kingdom); Giret, Yvelin [Department of Physics and Astronomy, London Centre for Nanotechnology, University College London, Gower Street, WC1E 6BT London (United Kingdom); The Institute of Scientific and Industrial Research (ISIR), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047 (Japan); Tanimura, Hiroshi; Tanimura, Katsumi [The Institute of Scientific and Industrial Research (ISIR), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047 (Japan)

    2014-07-14T23:59:59.000Z

    We used two methods to determine the effective electron-phonon coupling constant (G{sub 0}) in tungsten. Our first principles calculations predict G{sub 0}?=?1.65?×?10{sup 17?}W m{sup ?3} K{sup ?1}. The temporal decay of the femtosecond-resolution optical reflectivity for a (100) surface of bulk W was measured using a pump-probe scheme and analysed using ab initio parameterised two temperature model, which includes both the effects of the electron-phonon coupling and thermal conduction into bulk. This analysis gives G{sub 0}?=?1.4(3)?×?10{sup 17?}W m{sup ?3} K{sup ?1}, in good agreement with the theoretical prediction. The described effective method of calculating and measuring G{sub 0} in bulk materials can be easily extended to other metals.

  3. Gamma Spectrum from Neutron Capture on Tungsten Isotopes

    SciTech Connect (OSTI)

    Hurst, Aaron; Summers, Neil; Sleaford, Brad; Firestone, Richard B; Belgya, T.; Revay, Z.S.

    2010-04-29T23:59:59.000Z

    An evaluation of thermal neutron capture on the stable tungsten isotopes is presented, with preliminary results for the compound systems 183;184;185;187W. The evaluation procedure compares the g-ray cross-section data collected at the Budapest reactor, with Monte Carlo simulations of g-ray emission following the thermal neutron-capture process. The statistical-decay code DICEBOX was used for the Monte Carlo simulations. The evaluation yields new gamma rays in 185W and the confirmation of spins in 187W, raising the number of levels below which the level schemes are considered complete, thus increasing the number of levels that can be used in neutron data libraries.

  4. Performance of a Clad Tungsten Rod Spallation Neutron Source Target

    SciTech Connect (OSTI)

    Sommer, Walter F. [Los Alamos National Laboratory (United States); Maloy, Stuart A. [Los Alamos National Laboratory (United States); Louthan, McIntyre R. [Savannah River National Laboratory (United States); Willcutt, Gordon J. [Los Alamos National Laboratory (United States); Ferguson, Phillip D. [Oak Ridge National Laboratory (United States); James, Michael R. [Los Alamos National Laboratory (United States)

    2005-09-15T23:59:59.000Z

    Tungsten rods, slip-clad with Type 304L stainless steel, performed successfully as a spallation neutron source target operating to a peak fluence of {approx}4 x 10{sup 21} p/cm{sup 2}. The target was used as a neutron source during the Accelerator Production of Tritium (APT) materials irradiation program at the Los Alamos Neutron Science Center. Tungsten rods of 2.642-mm diameter were slip-fit in Type 304L stainless steel tubes that had an inner diameter of 2.667 mm. The radial gap was filled with helium at atmospheric pressure and room temperature. Los Alamos High Energy Transport (LAHET) calculations suggest a time-averaged peak power deposition in the W of 2.25 kW/cm{sup 3}. Thermal-hydraulic calculations indicate that the peak centerline W temperature reached 271 deg. C. The LAHET calculations were also used to predict neutron and proton fluxes and spectra for the complex geometry used in the irradiation program. Activation foil sets distributed throughout the experiment were used to determine target neutronics performance as a comparison to the LAHET calculations. Examination of the irradiated target assemblies revealed no significant surface degradation or corrosion on either the Type 304L or the W surfaces. However, it was clear that the irradiation changed material properties because post-proton-irradiation measurements on Type 304L test samples from the APT program demonstrated increases in the yield strength and decreases in the ductility and fracture toughness with increasing dose, and the wrought W rod samples became brittle. Fortunately, the slip-clad target design subjects the materials to very low stress.

  5. 3654 JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 24, NO. 10, OCTOBER 2006 High-Sensitivity Detection of Narrowband Light in a

    E-Print Network [OSTI]

    Guillas, Serge

    -emitting diode (LED), narrowband-filtered white light, and LED signal sources in a more intense tungsten-halogen-lamp

  6. Tungsten bridge for the low energy ignition of explosive and energetic materials

    DOE Patents [OSTI]

    Benson, D.A.; Bickes, R.W. Jr.; Blewer, R.S.

    1990-12-11T23:59:59.000Z

    A tungsten bridge device for the low energy ignition of explosive and energetic materials is disclosed. The device is fabricated on a silicon-on-sapphire substrate which has an insulating bridge element defined therein using standard integrated circuit fabrication techniques. Then, a thin layer of tungsten is selectively deposited on the silicon bridge layer using chemical vapor deposition techniques. Finally, conductive lands are deposited on each end of the tungsten bridge layer to form the device. It has been found that this device exhibits substantially shorter ignition times than standard metal bridges and foil igniting devices. In addition, substantially less energy is required to cause ignition of the tungsten bridge device of the present invention than is required for common metal bridges and foil devices used for the same purpose. 2 figs.

  7. Molecular dynamics simulation of deuterium trapping and bubble formation in tungsten

    E-Print Network [OSTI]

    Harilal, S. S.

    erosion rate [1]. In addition, tungsten is a high Z material, therefore the physical sputtering yield surface [5­7] or liquid lithium [8] has been recently studied, while others investigated the low energy

  8. Sintering and joining of low temperature co-fired tungsten and aluminum oxide

    E-Print Network [OSTI]

    Boonyongmaneerat, Yuttanant

    2006-01-01T23:59:59.000Z

    Conventional methods used to fabricate co-fired tungsten/alumina composites usually rely on high temperature processing (>1500C). As it would be beneficial or even necessary for some applications to produce such composites ...

  9. Syntheses of Tungsten tert-Butylimido and Adamantylimido Alkylidene Complexes Employing Pyridinium Chloride as the Acid

    E-Print Network [OSTI]

    Jeong, Hyangsoo

    Routes to new tungsten alkylidene complexes that contain tert-butylimido or adamantylimido ligands have been devised that begin with a reaction between WCl[subscript 6] and 4 equivalents of HNR(TMS) to give [W(NR)[subscript ...

  10. Molybdenum and Tungsten Monoalkoxide Pyrrolide (MAP) Alkylidene Complexes That Contain a 2,6-Dimesitylphenylimido Ligand

    E-Print Network [OSTI]

    Gerber, Laura C. H.

    Molybdenum and tungsten bispyrrolide alkylidene complexes that contain a 2,6-dimesitylphenylimido (NAr*) ligand have been prepared, in which the pyrrolide is the parent pyrrolide or 2,5-dimethylpyrrolide. Monoalkoxide ...

  11. Electropolymerized Polyaniline Stabilized Tungsten Oxide Nanocomposite Films: Electrochromic Behavior and Electrochemical

    E-Print Network [OSTI]

    Guo, John Zhanhu

    Electropolymerized Polyaniline Stabilized Tungsten Oxide Nanocomposite Films: Electrochromic. The optical properties and electrochemical capacitive behaviors of the composite films for electrochromic (EC electrochromism at both positive and negative potentials arising from PANI and WO3, respectively. A coloration

  12. Electrochromic properties of tungsten trioxide thin films prepared by photochemical vapor deposition

    SciTech Connect (OSTI)

    Maruyama, Toshiro; Kanagawa, Tetsuya (Kyoto Univ. (Japan). Dept. of Chemical Engineering)

    1994-09-01T23:59:59.000Z

    Electrochromic tungsten trioxide thin films were prepared by a photochemical vapor deposition. The source material was tungsten carbonyl. A 6 W low pressure mercury lamp was used as a light source. Amorphous tungsten trioxide thin films were obtained at a substrate temperature of 200 C. The UV radiation enhances the oxidation of tungsten, in addition to the acceleration of the deposition of the films. Reduction and oxidation of the films in a 0.3M LiClO[sub 4] propylene carbonate solution resulted in desirable changes in optimal absorption. The bleaching time was short compared to the amorphous CVD film. Coulometry indicated that the coloration efficiency was 222 cm[sup 2]/C.

  13. Simulation Studies of Hydrogen Ion reflection from Tungsten for the Surface Production of Negative Hydrogen Ions

    SciTech Connect (OSTI)

    Kenmotsu, Takahiro; Wada, Motoi [Doshisha University, Kyotanabe, Kyoto 610-0394 (Japan)

    2011-09-26T23:59:59.000Z

    The production efficiency of negative ions at tungsten surface by particle reflection has been investigated. Angular distributions and energy spectra of reflected hydrogen ions from tungsten surface are calculated with a Monte Carlo simulation code ACAT. The results obtained with ACAT have indicated that angular distributions of reflected hydrogen ions show narrow distributions for low-energy incidence such as 50 eV, and energy spectra of reflected ions show sharp peaks around 90% of incident energy. These narrow angular distributions and sharp peaks are favorable for the efficient extraction of negative ions from an ion source equipped with tungsten surface as negative ionization converter. The retained hydrogen atoms in tungsten lead to the reduction in extraction efficiency due to boarded angular distributions.

  14. Recent progress in R&D on tungsten alloys for divertor structural and plasma facing materials

    SciTech Connect (OSTI)

    Wurster, S.; Baluc, N.; Battabyal, M.; Crosby, T.; Du, J.; Garcia-Rosales, C.; Hasegawa, Akira; Hoffmann, A.; Kimura, A.; Kurishita, Hiroaki; Kurtz, Richard J.; Li, H.; Noh, S.; Reiser, J.; Riesch, J.; Rieth, Michael; Setyawan, Wahyu; Walter, M.; You, J. H.; Pippan, R.

    2013-03-13T23:59:59.000Z

    Tungsten materials are candidates for plasma facing components for ITER and DEMO because of their superior thermophysical properties. Knowledge and strategies to improve properties of tungsten-based materials are still under development, as they are not a common structural material such as steel. Consequently, several activities have started in Europe, Japan, USA and China. Research is directed towards manufacturing of new materials based on alloying, microstructure stabilizing and composite formation involving improved processing steps. Beside experimental analyses, work also focuses on computational treatment of open questions, supporting the development of better tungsten materials. Assuming the availability of an ideal material that is ready to use, there remain the questions of inherent safety, the joining of tungsten to steel and the influence of radiation damage. These are topics of increasing interest when the material comes to application.

  15. Tungsten bridge for the low energy ignition of explosive and energetic materials

    DOE Patents [OSTI]

    Benson, David A. (Albuquerque, NM); Bickes, Jr., Robert W. (Albuquerque, NM); Blewer, Robert S. (Albuquerque, NM)

    1990-01-01T23:59:59.000Z

    A tungsten bridge device for the low energy ignition of explosive and energetic materials is disclosed. The device is fabricated on a silicon-on-sapphire substrate which has an insulating bridge element defined therein using standard integrated circuit fabrication techniques. Then, a thin layer of tungsten is selectively deposited on the silicon bridge layer using chemical vapor deposition techniques. Finally, conductive lands are deposited on each end of the tungsten bridge layer to form the device. It has been found that this device exhibits substantially shorter ignition times than standard metal bridges and foil igniting devices. In addition, substantially less energy is required to cause ignition of the tungsten bridge device of the present invention than is required for common metal bridges and foil devices used for the same purpose.

  16. Multiphysics Design and Simulation of a Tungsten-Cermet Nuclear Thermal Rocket

    E-Print Network [OSTI]

    Appel, Bradley

    2012-10-19T23:59:59.000Z

    fuel safety have sparked interest in an NTR core based on tungsten-cermet fuel. This work investigates the capability of modern CFD and neutronics codes to design a cermet NTR, and makes specific recommendations for the configuration of channels...

  17. Tantalum-Tungsten Oxide Thermite Composite Prepared by Sol-Gel Synthesis and Spark Plasma Sintering

    SciTech Connect (OSTI)

    Cervantes, O; Kuntz, J; Gash, A; Munir, Z

    2009-02-13T23:59:59.000Z

    Energetic composite powders consisting of sol-gel derived nanostructured tungsten oxide were produced with various amounts of micrometer-scale tantalum fuel metal. Such energetic composite powders were ignition tested and results show that the powders are not sensitive to friction, spark and/or impact ignition. Initial consolidation experiments, using the High Pressure Spark Plasma Sintering (HPSPS) technique, on the sol-gel derived nanostructured tungsten oxide produced samples with higher relative density than can be achieved with commercially available tungsten oxide. The sol-gel derived nanostructured tungsten oxide with immobilized tantalum fuel metal (Ta - WO{sub 3}) energetic composite was consolidated to a density of 9.17 g.cm{sup -3} or 93% relative density. In addition those parts were consolidated without significant pre-reaction of the constituents, thus the sample retained its stored chemical energy.

  18. Kinetics of thermal decomposition of molybdenum carbonyl on a tungsten surface

    SciTech Connect (OSTI)

    Baev, A.K.; Podoprigora, V.I. [S.M. Kirov Belorussian Technological Inst., Minsk (Russian Federation)

    1993-04-20T23:59:59.000Z

    Thermal decomposition of Mo(CO){sub 6} on the surface of pyrolytic tungsten is performed under quasi-stationary conditions. The analysis of kinetics shows the reaction to occur in a kinetic region. The activation energy of Mo(CO){sub 6} decomposition on tungsten substrate calculated according to the Arrhenius equation is 63.7 {plus_minus} 3.0 kJ/mole. 4 refs., 1 fig., 1 tab.

  19. Molybdenum-copper and tungsten-copper alloys and method of making

    DOE Patents [OSTI]

    Schmidt, Frederick A. (Ames, IA); Verhoeven, John D. (Ames, IA); Gibson, Edwin D. (Ames, IA)

    1989-05-23T23:59:59.000Z

    Molybdenum-copper and tungsten-copper alloys are prepared by a consumable electrode method in which the electrode consists of a copper matrix with embedded strips of refractory molybdenum or tungsten. The electrode is progressively melted at its lower end with a superatmospheric inert gas pressure maintained around the liquifying electrode. The inert gas pressure is sufficiently above the vapor pressure of copper at the liquidus temperature of the alloy being formed to suppress boiling of liquid copper.

  20. Molybdenum-copper and tungsten-copper alloys and method of making

    DOE Patents [OSTI]

    Schmidt, F.A.; Verhoeven, J.D.; Gibson, E.D.

    1989-05-23T23:59:59.000Z

    Molybdenum-copper and tungsten-copper alloys are prepared by a consumable electrode method in which the electrode consists of a copper matrix with embedded strips of refractory molybdenum or tungsten. The electrode is progressively melted at its lower end with a superatmospheric inert gas pressure maintained around the liquefying electrode. The inert gas pressure is sufficiently above the vapor pressure of copper at the liquidus temperature of the alloy being formed to suppress boiling of liquid copper. 6 figs.

  1. Tungsten coating for improved wear resistance and reliability of microelectromechanical devices

    DOE Patents [OSTI]

    Fleming, James G. (Albuquerque, NM); Mani, Seethambal S. (Albuquerque, NM); Sniegowski, Jeffry J. (Edgewood, NM); Blewer, Robert S. (Albuquerque, NM)

    2001-01-01T23:59:59.000Z

    A process is disclosed whereby a 5-50-nanometer-thick conformal tungsten coating can be formed over exposed semiconductor surfaces (e.g. silicon, germanium or silicon carbide) within a microelectromechanical (MEM) device for improved wear resistance and reliability. The tungsten coating is formed after cleaning the semiconductor surfaces to remove any organic material and oxide film from the surface. A final in situ cleaning step is performed by heating a substrate containing the MEM device to a temperature in the range of 200-600 .degree. C. in the presence of gaseous nitrogen trifluoride (NF.sub.3). The tungsten coating can then be formed by a chemical reaction between the semiconductor surfaces and tungsten hexafluoride (WF.sub.6) at an elevated temperature, preferably about 450.degree. C. The tungsten deposition process is self-limiting and covers all exposed semiconductor surfaces including surfaces in close contact. The present invention can be applied to many different types of MEM devices including microrelays, micromirrors and microengines. Additionally, the tungsten wear-resistant coating of the present invention can be used to enhance the hardness, wear resistance, electrical conductivity, optical reflectivity and chemical inertness of one or more semiconductor surfaces within a MEM device.

  2. Growth study and photocatalytic properties of Co-doped tungsten oxide mesocrystals

    SciTech Connect (OSTI)

    Sun, Shibin [College of Logistics Engineering, Shanghai Maritime University, Shanghai 200135 (China) [College of Logistics Engineering, Shanghai Maritime University, Shanghai 200135 (China); College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061 (China); Chang, Xueting, E-mail: xuetingchang@yahoo.cn [College of Logistics Engineering, Shanghai Maritime University, Shanghai 200135 (China)] [College of Logistics Engineering, Shanghai Maritime University, Shanghai 200135 (China); Li, Zhenjiang [College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061 (China)] [College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao 266061 (China)

    2012-11-15T23:59:59.000Z

    Cobalt-doped tungsten oxide mesocrystals with different morphologies have been successfully generated using a solvothermal method with tungsten hexachloride and cobalt chloride salts as precursors. The resulting mesocrystals were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Brunauer-Emmet-Teller analysis of nitrogen sorptometer, and UV-vis diffuse reflectance spectroscopy. The photocatalytic properties of the cobalt-doped tungsten oxide mesocrystals were evaluated on the basis of their ability to degrade methyl orange in an aqueous solution under simulated sunlight irradiation. Results showed that the cobalt doping had obvious effect on the morphologies of the final products, and lenticular and blocky cobalt-doped tungsten oxide mesocrystals could be obtained with 1.0 wt.% and 2.0 wt.% cobalt doping, respectively. The cobalt-doped tungsten oxides exhibited superior photocatalytic activities to that of the undoped tungsten oxide. - Graphical abstract: Schematic illustrations of the growth of the bundled nanowires, lenticular mesocrystals, and blocky mesocrystals. Highlights: Black-Right-Pointing-Pointer Co-doped W{sub 18}O{sub 49} mesocrystals were synthesized using a solvothermal method. Black-Right-Pointing-Pointer The Co doping has obvious effect on the morphology of the final mesocrystals. Black-Right-Pointing-Pointer The Co-doped W{sub 18}O{sub 49} exhibited superior photocatalytic activity to the undoped W{sub 18}O{sub 49}.

  3. Study on the oxidation and reduction of tungsten surface for sub-50 nm patterning process

    SciTech Connect (OSTI)

    Kim, Jong Kyu; Nam, Seok Woo; Cho, Sung Il; Jhon, Myung S.; Min, Kyung Suk; Kim, Chan Kyu; Jung, Ho Bum; Yeom, Geun Young [Memory Division Semiconductor Business, Samsung Electronics, San No. 16 Banwol-Ri, Taean-Eup, Hwasung-City, Gyeonggi-Do 449-711, South Korea and Department of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Memory Division Semiconductor Business, Samsung Electronics, San No. 16 Banwol-Ri, Taean-Eup, Hwasung-City, Gyeonggi-Do 449-711 (Korea, Republic of); Department of Chemical Engineering and Data Storage Systems Center, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Department of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746 (Korea, Republic of)

    2012-11-15T23:59:59.000Z

    The oxidation characteristics of tungsten line pattern during the carbon-based mask-layer removal process using oxygen plasmas have been investigated for sub-50 nm patterning processes, in addition to the reduction characteristics of the WO{sub x} layer formed on the tungsten line surface using hydrogen plasmas. The surface oxidation of tungsten lines during the mask layer removal process could be minimized by using low-temperature (300 K) plasma processing for the removal of the carbon-based material. Using this technique, the thickness of WO{sub x} on the tungsten line could be decreased to 25% compared to results from high-temperature processing. The WO{sub x} layer could also be completely removed at a low temperature of 300 K using a hydrogen plasma by supplying bias power to the tungsten substrate to provide a activation energy for the reduction. When this oxidation and reduction technique was applied to actual 40-nm-CD device processing, the complete removal of WO{sub x} formed on the sidewall of tungsten line could be observed.

  4. Synthesis and electrochemical capacitance of long tungsten oxide nanorod arrays grown vertically on substrate

    SciTech Connect (OSTI)

    Park, Sun Hwa [Department of Nanomaterials Science and Engineering, University of Science and Technology, Daejeon 305-350 (Korea, Republic of)] [Department of Nanomaterials Science and Engineering, University of Science and Technology, Daejeon 305-350 (Korea, Republic of); Kim, Young Heon; Lee, Tae Geol; Shon, Hyun Kyong [Korea Research Institute of Standards and Science, Daejeon 305-340 (Korea, Republic of)] [Korea Research Institute of Standards and Science, Daejeon 305-340 (Korea, Republic of); Park, Hyun Min [Department of Nanomaterials Science and Engineering, University of Science and Technology, Daejeon 305-350 (Korea, Republic of) [Department of Nanomaterials Science and Engineering, University of Science and Technology, Daejeon 305-350 (Korea, Republic of); Korea Research Institute of Standards and Science, Daejeon 305-340 (Korea, Republic of); Song, Jae Yong, E-mail: jysong@kriss.re.kr [Korea Research Institute of Standards and Science, Daejeon 305-340 (Korea, Republic of); Department of Nano Science, University of Science and Technology, Daejeon 305-350 (Korea, Republic of)

    2012-11-15T23:59:59.000Z

    Highlights: ? Growth of long amorphous tungsten oxide nanorods on a substrate. ? Formation of single-crystalline tungsten oxide nanorods by a heat-treatment. ? High electrochemical pseudocapacitance of 2.8 mF cm{sup ?2}. ? Excellent cyclability of psuedocapacitance up to 1000 cycles. -- Abstract: Long tungsten oxide nanorods are vertically grown on Al/W/Ti coated silicon substrates using a two-step anodization process. The first anodization of the Al film forms a mesh-like mask of anodic aluminum oxide, and the second anodization of the W film results in the formation of a buffer layer, a bottom nanorod, and a top nanorod of amorphous tungsten oxide. A pore-widening process prior to the second anodization leads to the enhancement of nanorod length above approximately 500 nm. After a heat-treatment, the tungsten oxide nanorods are crystallized to form a single crystalline structure while the buffer layer forms a polycrystalline structure. The crystalline tungsten oxide nanorods show a cyclic voltammogram retaining the quasi-rectangular shape of an electrochemically reversible faradaic redox reaction, i.e., a typical pseudocapacitive behavior. The maximum electrochemical capacitance per apparent surface area reaches approximately 2.8 mF cm{sup ?2} at the voltage scan rate of 20 mV s{sup ?1}, and the excellent cyclability of charge–discharge process is maintained up to 1000 cycles.

  5. Determination of heavy metals and halogens in plastics from electric and electronic waste

    SciTech Connect (OSTI)

    Dimitrakakis, Emmanouil [Laboratory of Toxic and Hazardous Waste Management, Department of Environmental Engineering, Technical University of Crete, University Campus, 73100 Chania (Greece); Janz, Alexander; Bilitewski, Bernd [Institute for Waste Management and Contaminated Site Treatment, Dresden University of Technology, Pratzschwitzerstrasse 15, 01796 Pirna (Germany); Gidarakos, Evangelos [Laboratory of Toxic and Hazardous Waste Management, Department of Environmental Engineering, Technical University of Crete, University Campus, 73100 Chania (Greece)], E-mail: gidarako@mred.tuc.gr

    2009-10-15T23:59:59.000Z

    The presence of hazardous substances and preparations in small waste electrical and electronic equipment (sWEEE) found in the residual household waste stream of the city of Dresden, Germany has been investigated. The content of sWEEE plastics in heavy metals and halogens is determined using handheld X-ray fluorescence analysis (HXRF), elemental analysis by means of atomic absorption spectrometry (AAS) and ion exchange chromatography (IEC). Mean value of results for heavy metals in samples (n = 51) by AAS are 17.4 mg/kg for Pb, 5.7 mg/kg for Cd, 8.4 mg/kg for Cr. The mass fraction of an additive as shown by HXRF (n = 161) can vary over a wide range. Precise deductions as regards sWEEE plastics content in hazardous substances and preparations cannot be made. Additional research would be expedient regarding the influence of hazardous substances to recycling processes, in particular regarding the contamination of clean fractions in the exit streams of a WEEE treatment plant. Suitable standards for calibrating HXRF for use on EEE plastics or complex electr(on)ic components do not exist and should be developed.

  6. A continuous fast-response dual-tracer analyzer for halogenated atmospheric tracer studies

    SciTech Connect (OSTI)

    Rydock, J.P.; Lamb, B.K. [Washington State Univ., Pullman, WA (United States)] [Washington State Univ., Pullman, WA (United States)

    1994-10-01T23:59:59.000Z

    An apparatus for the simultaneous measurement of two tracers, sulfur hexafluoride (SF6) and a perfluorocarbon compound, is introduced. The new instrument is a modification of a commercially available fast-response, continuous analyzer for single halogenated atmospheric tracer studies. A two-channel flow system was implemented consisting of an alumina cartridge in one channel and a glass beads cartridge of equal flow resistance in the second channel. The alumina passes only sulfur hexafluoride, while the glass beads pass both SF6 and the perfluoroarbon tracer. The SF6 is quantified directly from the electron capture detector (ECD) signal in the alumina channel, and the perfluorocarbon concentration is obtained from the difference of the ECD responses in the two channels. The dual-tracer analyzer is field portable for mobile operations or fixed-location monitoring, has a response time of 1.2 s, and has limits of detection of about 15 pptv for SF6 and 10 pptv for perfluoro-methylcyclohexane, which was the principal perfluorocarbon tracer used in this study. The present instrument configuration, which requires periodic purging of the adsorbent trap, can obtain continuous measurements for a 10-15-min segment in every half hour of operation. Dual-tracer data from a field demonstration test are presented.

  7. B(C6F5)3 Activation of Oxo Tungsten Complexes That Are Relevant to Olefin Metathesis

    E-Print Network [OSTI]

    Müller, Peter

    B(C6F5)3 Activation of Oxo Tungsten Complexes That Are Relevant to Olefin Metathesis Dmitry V Information ABSTRACT: We have found that coordination of B(C6F5)3 to an oxo ligand in tungsten oxo alkylidene reactions between a relatively well behaved Lewis acid (B(C6F5)3) and a variety of tungsten oxo complexes

  8. Reduced ternary molybdenum and tungsten sulfides and hydroprocessing catalysis therewith

    DOE Patents [OSTI]

    Hilsenbeck, S.J.; McCarley, R.E.; Schrader, G.L.; Xie, X.B.

    1999-02-16T23:59:59.000Z

    New amorphous molybdenum/tungsten sulfides with the general formula M{sup n+}{sub 2x/n}(L{sub 6}S{sub 8})S{sub x}, where L is molybdenum or tungsten and M is a ternary metal, has been developed. Characterization of these amorphous materials by chemical and spectroscopic methods (IR, Raman, PES) shows that the (M{sub 6}S{sub 8}){sup 0} cluster units are present. Vacuum thermolysis of the amorphous Na{sub 2x}(Mo{sub 6}S{sub 8})S{sub x}{hor_ellipsis}yMeOH first produces poorly crystalline NaMo{sub 6}S{sub 8} by disproportionation at 800 C and well-crystallized NaMo{sub 6}S{sub 8} at {>=} 900 C. Ion-exchange of the sodium material in methanol with soluble M{sup 2+} and M{sup 3+} salts (M=Sn, Co, Ni, Pb, La, Ho) produces the M{sup n+}{sub 2x/n}(Mo{sub 6}S{sub 8})S{sub x}{hor_ellipsis}yMeOH compounds. Additionally, the new reduced ternary molybdenum sulfides with the general formula M{sup n+}{sub 2x/n}Mo{sub 6}S{sub 8+x}(MeOH){sub y}[MMOS] (M=Sn, Co, Ni) is an effective hydrodesulfurization (HDS) catalyst both as-prepared and after a variety of pretreatment conditions. Under specified pretreatment conditions with flowing hydrogen gas, the SnMoS type catalyst can be stabilized, and while still amorphous, can be considered as ``Chevrel phase-like`` in that both contain Mo{sub 6}S{sub 8} cluster units. Furthermore, the small cation NiMoS and CoMoS type pretreated catalyst is shown to be very active HDS catalysts with rates that exceeded the model unpromoted and cobalt-promoted MoS{sub 2} catalysts. 9 figs.

  9. Reduced ternary molybdenum and tungsten sulfides and hydroprocessing catalysis therewith

    DOE Patents [OSTI]

    Hilsenbeck, Shane J. (Ames, IA); McCarley, Robert E. (Ames, IA); Schrader, Glenn L. (Ames, IA); Xie, Xiaobing (College Station, TX)

    1999-02-16T23:59:59.000Z

    New amorphous molybdenum/tungsten sulfides with the general formula M.sup.n+.sub.2x/n (L.sub.6 S.sub.8)S.sub.x, where L is molybdenum or tungsten and M is a ternary metal, has been developed. Characterization of these amorphous materials by chemical and spectroscopic methods (IR, Raman, PES) shows that the (M.sub.6 S.sub.8).sup.0 cluster units are present. Vacuum thermolysis of the amorphous Na.sub.2x (Mo.sub.6 S.sub.8)S.sub.x .multidot.yMeOH first produces poorly crystalline NaMo.sub.6 S.sub.8 by disproportionation at 800.degree. C. and well-crystallized NaMo.sub.6 S.sub.8 at .gtoreq. 900.degree. C. Ion-exchange of the sodium material in methanol with soluble M.sup.2+ and M.sup.3+ salts (M=Sn, Co, Ni, Pb, La, Ho) produces the M.sup.n+.sub.2x/n (Mo.sub.6 S.sub.8)S.sub.x .multidot.yMeOH compounds. Additionally, the new reduced ternary molybdenum sulfides with the general formula M.sup.n+.sub.2x/n Mo.sub.6 S.sub.8+x (MeOH).sub.y ›MMOS! (M=Sn, Co, Ni) is an effective hydrodesulfurization (HDS) catalyst both as-prepared and after a variety of pretreatment conditions. Under specified pretreatment conditions with flowing hydrogen gas, the SnMoS type catalyst can be stabilized, and while still amorphous, can be considered as "Chevrel phase-like" in that both contain Mo.sub.6 S.sub.8 cluster units. Furthermore, the small cation NiMoS and CoMoS type pretreated catalyst showed to be very active HDS catalysts with rates that exceeded the model unpromoted and cobalt-promoted MoS.sub.2 catalysts.

  10. Development of an electron-temperature-dependent interatomic potential for molecular dynamics simulation of tungsten under electronic excitation

    E-Print Network [OSTI]

    Alfè, Dario

    simulation of tungsten under electronic excitation S. Khakshouri,1,* D. Alfè,1,2 and D. M. Duffy1,3 1

  11. Magnetization curves of sintered heavy tungsten alloys for applications in MRI-guided radiotherapy

    SciTech Connect (OSTI)

    Kolling, Stefan [Sydney Medical School, University of Sydney, NSW 2006 (Australia)] [Sydney Medical School, University of Sydney, NSW 2006 (Australia); Oborn, Bradley M. [Illawarra Cancer Care Centre (ICCC), Wollongong, NSW 2500, Australia and Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2500 (Australia)] [Illawarra Cancer Care Centre (ICCC), Wollongong, NSW 2500, Australia and Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2500 (Australia); Keall, Paul J., E-mail: paul.keall@sydney.edu.au [Sydney Medical School, University of Sydney, NSW 2006, Australia and Ingham Institute for Applied Medical Research, Liverpool, NSW 2170 (Australia); Horvat, Joseph [Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW 2500, Australia and School of Physics, University of Wollongong, Wollongong, NSW 2500 (Australia)] [Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW 2500, Australia and School of Physics, University of Wollongong, Wollongong, NSW 2500 (Australia)

    2014-06-15T23:59:59.000Z

    Purpose: Due to the current interest in MRI-guided radiotherapy, the magnetic properties of the materials commonly used in radiotherapy are becoming increasingly important. In this paper, measurement results for the magnetization (BH) curves of a range of sintered heavy tungsten alloys used in radiation shielding and collimation are presented. Methods: Sintered heavy tungsten alloys typically contain >90?% tungsten and <10?% of a combination of iron, nickel, and copper binders. Samples of eight different grades of sintered heavy tungsten alloys with varying binder content were investigated. Using a superconducting quantum interference detector magnetometer, the induced magnetic momentm was measured for each sample as a function of applied external field H{sub 0} and the BH curve derived. Results: The iron content of the alloys was found to play a dominant role, directly influencing the magnetizationM and thus the nonlinearity of the BH curve. Generally, the saturation magnetization increased with increasing iron content of the alloy. Furthermore, no measurable magnetization was found for all alloys without iron content, despite containing up to 6% of nickel. For two samples from different manufacturers but with identical quoted nominal elemental composition (95% W, 3.5% Ni, 1.5% Fe), a relative difference in the magnetization of 11%–16% was measured. Conclusions: The measured curves show that the magnetic properties of sintered heavy tungsten alloys strongly depend on the iron content, whereas the addition of nickel in the absence of iron led to no measurable effect. Since a difference in the BH curves for two samples with identical quoted nominal composition from different manufacturers was observed, measuring of the BH curve for each individual batch of heavy tungsten alloys is advisable whenever accurate knowledge of the magnetic properties is crucial. The obtained BH curves can be used in FEM simulations to predict the magnetic impact of sintered heavy tungsten alloys.

  12. Spectroscopic constants and potential energy curves of tungsten carbide

    SciTech Connect (OSTI)

    Balasubramanian, K. [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604 (United States)] [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604 (United States)

    2000-05-01T23:59:59.000Z

    Spectroscopic constants (R{sub e},{omega}{sub e},T{sub e},{mu}{sub e}) and potential energy curves for 40 low-lying electronic states of the diatomic tungsten carbide (WC) were obtained using the complete active space multiconfiguration self-consistent field followed by the multireference singles+doubles configuration interaction and full first- and second-order configuration interaction calculations that included up to 6.4 mil configurations. Spin-orbit effects were included through the enhanced relativistic configuration interaction method described here for 28 electronic states of WC lying below {approx}20 000 cm-1. The spin-orbit splitting of the ground state of WC was found to be very large (4394 cm-1). The ground and excited electronic states of the W atom were also computed and were found to be in good agreement with the experimental data. The nature of bonding was analyzed through the composition of orbitals, leading configurations, Mulliken populations, and dipole moments. The dissociation energy of WC was computed including spin-orbit and electron correlation effects. The recent photoelectron spectra of WC{sup -} were assigned on the basis of our computed results. (c) 2000 American Institute of Physics.

  13. Activation Energy of Tantalum-Tungsten Oxide Thermite Reaction

    SciTech Connect (OSTI)

    Cervantes, O; Kuntz, J; Gash, A; Munir, Z

    2010-02-25T23:59:59.000Z

    The activation energy of a high melting temperature sol-gel (SG) derived tantalum-tungsten oxide thermite composite was determined using the Kissinger isoconversion method. The SG derived powder was consolidated using the High Pressure Spark Plasma Sintering (HPSPS) technique to 300 and 400 C to produce pellets with dimensions of 5 mm diameter by 1.5 mm height. A custom built ignition setup was developed to measure ignition temperatures at high heating rates (500-2000 C {center_dot} min{sup -1}). Such heating rates were required in order to ignite the thermite composite. Unlike the 400 C samples, results show that the samples consolidated to 300 C undergo an abrupt change in temperature response prior to ignition. This change in temperature response has been attributed to the crystallization of the amorphous WO{sub 3} in the SG derived Ta-WO{sub 3} thermite composite and not to a pre-ignition reaction between the constituents. Ignition temperatures for the Ta-WO{sub 3} thermite ranged from approximately 465-670 C. The activation energy of the SG derived Ta-WO{sup 3} thermite composite consolidated to 300 and 400 C were determined to be 37.787 {+-} 1.58 kJ {center_dot} mol{sup -1} and 57.381 {+-} 2.26 kJ {center_dot} mol{sup -1}, respectively.

  14. Adsorption of carbonyl sulfide on nickel and tungsten films

    SciTech Connect (OSTI)

    Saleh, J.M.; Nasser, F.A.K.

    1985-07-18T23:59:59.000Z

    The interaction of carbonyl sulfide with evaporated nickel and tungsten films has been investigated in the temperature range 195-450 K using gas pressures ranging from 1 to 13 N m/sup -2/. Rapid but mainly associative chemisorption of COS occurred on both metals at 195 K. Further adsorption of COS on W at temperatures 293-450 K was extremely slow and accompanied by more CO desorption than COS adsorbed. Sulfidation of Ni film by COS occurred at temperatures greater than or equal to 293 K with the liberation of carbon monoxide. The rate of adsorption increased with temperature but was independent of COS pressure. The activation energy (E/sub x/) increased with extent (X) of sulfidation to a limiting value of 97 kJ mol/sup -1/. A linear relationship was obtained from the plot of E/sub x/ against 1/X, suggesting the applicability of Cabrera-Mott theory to the sulfidation of Ni film by COS. 20 references, 2 figures, 1 table.

  15. DISPLACEMENT CASCADE SIMULATION IN TUNGSTEN AT 1025 K

    SciTech Connect (OSTI)

    Setyawan, Wahyu; Nandipati, Giridhar; Roche, Kenneth J.; Heinisch, Howard L.; Kurtz, Richard J.; Wirth, Brian D.

    2013-09-30T23:59:59.000Z

    Molecular dynamics simulation was employed to investigate the irradiation damage properties of bulk tungsten at 1025 K (0.25 melting temperature). A comprehensive data set of primary cascade damage was generated up to primary knock-on atom (PKA) energies 100 keV. The dependence of the number of surviving Frenkel pairs (NFP) on the PKA energy (E) exhibits three different characteristic domains presumably related to the different cascade morphologies that form. The low-energy regime < 0.2 keV is characterized by a hit-or-miss type of Frenkel pair (FP) production near the displacement threshold energy of 128 eV. The middle regime 0.3 – 30 keV exhibits a sublinear dependence of log(NFP) vs log(E) associated with compact cascade morphology with a slope of 0.73. Above 30 keV, the cascade morphology consists of complex branches or interconnected damage regions. In this extended morphology, large interstitial clusters form from superposition of interstitials from nearby damage regions. Strong clustering above 30 keV results in a superlinear dependence of log(NFP) vs log(E) with a slope of 1.365. At 100 keV, an interstitial cluster of size 92 and a vacancy cluster of size 114 were observed.

  16. In vivo corrosion, tumor outcome, and microarray gene expression for two types of muscle-implanted tungsten alloys

    SciTech Connect (OSTI)

    Schuster, B.E. [U.S. Army Research Laboratory, Weapons and Materials Research Directorate, B434 Mulberry Road, Aberdeen Proving Ground, MD 21005-5609 (United States)] [U.S. Army Research Laboratory, Weapons and Materials Research Directorate, B434 Mulberry Road, Aberdeen Proving Ground, MD 21005-5609 (United States); Roszell, L.E. [U.S. Army Institute of Public Health, 5158 Blackhawk Road, Aberdeen Proving Ground, MD 21010?5403 (United States)] [U.S. Army Institute of Public Health, 5158 Blackhawk Road, Aberdeen Proving Ground, MD 21010?5403 (United States); Murr, L.E.; Ramirez, D.A. [Department of Metallurgical and Materials Engineering, University of Texas, El Paso, TX 79968 (United States)] [Department of Metallurgical and Materials Engineering, University of Texas, El Paso, TX 79968 (United States); Demaree, J.D. [U.S. Army Research Laboratory, Weapons and Materials Research Directorate, B434 Mulberry Road, Aberdeen Proving Ground, MD 21005-5609 (United States)] [U.S. Army Research Laboratory, Weapons and Materials Research Directorate, B434 Mulberry Road, Aberdeen Proving Ground, MD 21005-5609 (United States); Klotz, B.R. [Dynamic Science Inc., Aberdeen Proving Ground, MD 21005?5609 (United States)] [Dynamic Science Inc., Aberdeen Proving Ground, MD 21005?5609 (United States); Rosencrance, A.B.; Dennis, W.E. [U.S. Army Center for Environmental Health Research, Department of Chemistry, Ft. Detrick, MD 21702?5010 (United States)] [U.S. Army Center for Environmental Health Research, Department of Chemistry, Ft. Detrick, MD 21702?5010 (United States); Bao, W. [SAS Institute, Inc. SAS Campus Drive, Cary, NC 27513 (United States)] [SAS Institute, Inc. SAS Campus Drive, Cary, NC 27513 (United States); Perkins, E.J. [U.S. Army Engineer Research and Development Center, 3909 Hall Ferry Road, Vicksburg MS 39180 (United States)] [U.S. Army Engineer Research and Development Center, 3909 Hall Ferry Road, Vicksburg MS 39180 (United States); Dillman, J.F. [U.S. Army Medical Research Institute of Chemical Defense, 3100 Ricketts Point Road, Aberdeen Proving Ground, MD 21010?5400 (United States)] [U.S. Army Medical Research Institute of Chemical Defense, 3100 Ricketts Point Road, Aberdeen Proving Ground, MD 21010?5400 (United States); Bannon, D.I., E-mail: desmond.bannon@us.army.mil [U.S. Army Institute of Public Health, 5158 Blackhawk Road, Aberdeen Proving Ground, MD 21010?5403 (United States)

    2012-11-15T23:59:59.000Z

    Tungsten alloys are composed of tungsten microparticles embedded in a solid matrix of transition metals such as nickel, cobalt, or iron. To understand the toxicology of these alloys, male F344 rats were intramuscularly implanted with pellets of tungsten/nickel/cobalt, tungsten/nickel/iron, or pure tungsten, with tantalum pellets as a negative control. Between 6 and 12 months, aggressive rhabdomyosarcomas formed around tungsten/nickel/cobalt pellets, while those of tungsten/nickel/iron or pure tungsten did not cause cancers. Electron microscopy showed a progressive corrosion of the matrix phase of tungsten/nickel/cobalt pellets over 6 months, accompanied by high urinary concentrations of nickel and cobalt. In contrast, non-carcinogenic tungsten/nickel/iron pellets were minimally corroded and urinary metals were low; these pellets having developed a surface oxide layer in vivo that may have restricted the mobilization of carcinogenic nickel. Microarray analysis of tumors revealed large changes in gene expression compared with normal muscle, with biological processes involving the cell cycle significantly up?regulated and those involved with muscle development and differentiation significantly down?regulated. Top KEGG pathways disrupted were adherens junction, p53 signaling, and the cell cycle. Chromosomal enrichment analysis of genes showed a highly significant impact at cytoband 7q22 (chromosome 7) which included mouse double minute (MDM2) and cyclin?dependant kinase (CDK4) as well as other genes associated with human sarcomas. In conclusion, the tumorigenic potential of implanted tungsten alloys is related to mobilization of carcinogenic metals nickel and cobalt from corroding pellets, while gene expression changes in the consequent tumors are similar to radiation induced animal sarcomas as well as sporadic human sarcomas. -- Highlights: ? Tungsten/nickel/cobalt, tungsten/nickel/iron, and pure tungsten were studied. ? Male Fischer rats implanted with pellets in gastrocnemius muscle of each hind leg. ? Aggressive rhabdomyosarcomas developed from tungsten/nickel/cobalt pellets only. ? Microarray gene expression analysis was carried out on selected tumors. ? Pellet degradation, urinary metal concentration, and sarcoma were correlated.

  17. In vitro profiling of epigenetic modifications underlying heavy metal toxicity of tungsten-alloy and its components

    SciTech Connect (OSTI)

    Verma, Ranjana, E-mail: Ranjana.Verma.CTR@usuhs.mil [Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 (United States); Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 (United States); Xu, Xiufen, E-mail: Xiufen.Xu.CTR@usuhs.mil [Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 (United States); Jaiswal, Manoj K., E-mail: Manoj.Jaiswal.CTR@usuhs.mil [Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 (United States); Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 (United States); Olsen, Cara, E-mail: colsen@usuhs.mil [Department of Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 (United States); Mears, David, E-mail: dmears@usuhs.mil [Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 (United States); Caretti, Giuseppina, E-mail: giuseppina.caretti@unimi.it [Department of Biomolecular Sciences and Biotechnology, University of Milan (Italy); Galdzicki, Zygmunt, E-mail: zgaldzicki@usuhs.mil [Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 (United States); Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 (United States)

    2011-06-15T23:59:59.000Z

    Tungsten-alloy has carcinogenic potential as demonstrated by cancer development in rats with intramuscular implanted tungsten-alloy pellets. This suggests a potential involvement of epigenetic events previously implicated as environmental triggers of cancer. Here, we tested metal induced cytotoxicity and epigenetic modifications including H3 acetylation, H3-Ser10 phosphorylation and H3-K4 trimethylation. We exposed human embryonic kidney (HEK293), human neuroepithelioma (SKNMC), and mouse myoblast (C2C12) cultures for 1-day and hippocampal primary neuronal cultures for 1-week to 50-200 {mu}g/ml of tungsten-alloy (91% tungsten/6% nickel/3% cobalt), tungsten, nickel, and cobalt. We also examined the potential role of intracellular calcium in metal mediated histone modifications by addition of calcium channel blockers/chelators to the metal solutions. Tungsten and its alloy showed cytotoxicity at concentrations > 50 {mu}g/ml, while we found significant toxicity with cobalt and nickel for most tested concentrations. Diverse cell-specific toxic effects were observed, with C2C12 being relatively resistant to tungsten-alloy mediated toxic impact. Tungsten-alloy, but not tungsten, caused almost complete dephosphorylation of H3-Ser10 in C2C12 and hippocampal primary neuronal cultures with H3-hypoacetylation in C2C12. Dramatic H3-Ser10 dephosphorylation was found in all cobalt treated cultures with a decrease in H3 pan-acetylation in C2C12, SKNMC and HEK293. Trimethylation of H3-K4 was not affected. Both tungsten-alloy and cobalt mediated H3-Ser10 dephosphorylation were reversed with BAPTA-AM, highlighting the role of intracellular calcium, confirmed with 2-photon calcium imaging. In summary, our results for the first time reveal epigenetic modifications triggered by tungsten-alloy exposure in C2C12 and hippocampal primary neuronal cultures suggesting the underlying synergistic effects of tungsten, nickel and cobalt mediated by changes in intracellular calcium homeostasis and buffering. - Highlights: > Tungsten-alloy caused H3-Ser10 dephosphorylation in C2C12 and hippocampal primary cultures. > Dramatic H3-Ser10 dephosphorylation was found in all cobalt treated cultures. > C2C12 cultures exposed to tungsten-alloy or cobalt exhibited decrease in H3 pan-acetylation. > Tungsten-alloy and cobalt mediated H3-Ser10 dephosphorylation was reversed with BAPTA-AM. > These epigenetic modifications were mediated by changes in calcium homeostasis and buffering.

  18. Effect of interfacial interactions on the thermal conductivity and interfacial thermal conductance in tungsten–graphene layered structure

    SciTech Connect (OSTI)

    Jagannadham, K., E-mail: jag-kasichainula@ncsu.edu [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States)

    2014-09-01T23:59:59.000Z

    Graphene film was deposited by microwave plasma assisted deposition on polished oxygen free high conductivity copper foils. Tungsten–graphene layered film was formed by deposition of tungsten film by magnetron sputtering on the graphene covered copper foils. Tungsten film was also deposited directly on copper foil without graphene as the intermediate film. The tungsten–graphene–copper samples were heated at different temperatures up to 900?°C in argon atmosphere to form an interfacial tungsten carbide film. Tungsten film deposited on thicker graphene platelets dispersed on silicon wafer was also heated at 900?°C to identify the formation of tungsten carbide film by reaction of tungsten with graphene platelets. The films were characterized by scanning electron microscopy, Raman spectroscopy, and x-ray diffraction. It was found that tungsten carbide film formed at the interface upon heating only above 650?°C. Transient thermoreflectance signal from the tungsten film surface on the samples was collected and modeled using one-dimensional heat equation. The experimental and modeled results showed that the presence of graphene at the interface reduced the cross-plane effective thermal conductivity and the interfacial thermal conductance of the layer structure. Heating at 650 and 900?°C in argon further reduced the cross-plane thermal conductivity and interface thermal conductance as a result of formation nanocrystalline tungsten carbide at the interface leading to separation and formation of voids. The present results emphasize that interfacial interactions between graphene and carbide forming bcc and hcp elements will reduce the cross-plane effective thermal conductivity in composites.

  19. Separation of toxic metal ions, hydrophilic hydrocarbons, hydrophobic fuel and halogenated hydrocarbons and recovery of ethanol from a process stream

    DOE Patents [OSTI]

    Kansa, Edward J. (Livermore, CA); Anderson, Brian L. (Lodi, CA); Wijesinghe, Ananda M. (Tracy, CA); Viani, Brian E. (Oakland, CA)

    1999-01-01T23:59:59.000Z

    This invention provides a process to tremendously reduce the bulk volume of contaminants obtained from an effluent stream produced subsurface remediation. The chemicals used for the subsurface remediation are reclaimed for recycling to the remediation process. Additional reductions in contaminant bulk volume are achieved by the ultra-violet light destruction of halogenated hydrocarbons, and the complete oxidation of hydrophobic fuel hydrocarbons and hydrophilic hydrocarbons. The contaminated bulk volume will arise primarily from the disposal of the toxic metal ions. The entire process is modular, so if there are any technological breakthroughs in one or more of the component process modules, such modules can be readily replaced.

  20. Separation of toxic metal ions, hydrophilic hydrocarbons, hydrophobic fuel and halogenated hydrocarbons and recovery of ethanol from a process stream

    DOE Patents [OSTI]

    Kansa, E.J.; Anderson, B.L.; Wijesinghe, A.M.; Viani, B.E.

    1999-05-25T23:59:59.000Z

    This invention provides a process to tremendously reduce the bulk volume of contaminants obtained from an effluent stream produced subsurface remediation. The chemicals used for the subsurface remediation are reclaimed for recycling to the remediation process. Additional reductions in contaminant bulk volume are achieved by the ultra-violet light destruction of halogenated hydrocarbons, and the complete oxidation of hydrophobic fuel hydrocarbons and hydrophilic hydrocarbons. The contaminated bulk volume will arise primarily from the disposal of the toxic metal ions. The entire process is modular, so if there are any technological breakthroughs in one or more of the component process modules, such modules can be readily replaced. 3 figs.

  1. Evolution of sputtered tungsten coatings at high temperature

    SciTech Connect (OSTI)

    Stelmakh, Veronika; Rinnerbauer, Veronika; Joannopoulos, John D.; Solja?i?, Marin; Celanovic, Ivan; Senkevich, Jay J. [Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)] [Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Tucker, Charles; Ives, Thomas; Shrader, Ronney [Materion Corporation, Buellton, California 93427 (United States)] [Materion Corporation, Buellton, California 93427 (United States)

    2013-11-15T23:59:59.000Z

    Sputtered tungsten (W) coatings were investigated as potential high temperature nanophotonic material to replace bulk refractory metal substrates. Of particular interest are materials and coatings for thermophotovoltaic high-temperature energy conversion applications. For such applications, high reflectance of the substrate in the infrared wavelength range is critical in order to reduce losses due to waste heat. Therefore, the reflectance of the sputtered W coatings was characterized and compared at different temperatures. In addition, the microstructural evolution of sputtered W coatings (1 and 5 ?m thick) was investigated as a function of anneal temperature from room temperature to 1000 °C. Using in situ x-ray diffraction analysis, the microstrain in the two samples was quantified, ranging from 0.33% to 0.18% for the 1 ?m sample and 0.26% to 0.20% for the 5 ?m sample, decreasing as the temperature increased. The grain growth could not be as clearly quantified due to the dominating presence of microstrain in both samples but was in the order of 20 to 80 nm for the 1 ?m sample and 50 to 100 nm for the 5 ?m sample, as deposited. Finally, the 5 ?m thick layer was found to be rougher than the 1 ?m thick layer, with a lower reflectance at all wavelengths. However, after annealing the 5 ?m sample at 900 °C for 1 h, its reflectance exceeded that of the 1 ?m sample and approached that of bulk W found in literature. Overall, the results of this study suggest that thick coatings are a promising alternative to bulk substrates as a low cost, easily integrated platform for nanostructured devices for high-temperature applications, if the problem of delamination at high temperature can be overcome.

  2. Molecular dynamics simulation of erosion and surface evolution of tungsten due to bombardment with deuterium and carbon in

    E-Print Network [OSTI]

    Harilal, S. S.

    Simultaneous carbon and deuterium bombardment Hydrogen bubble formation Tungsten sputtering yield a b s t r a c. Carbon pre-irradiated tungsten tends to trap more hydrogen and facilitates gas bubble formation with deuterium and carbon in Tokamak fusion environments Xue Yang , Ahmed Hassanein Center for Material under

  3. Gas phase reaction products during tungsten atomic layer deposition using WF6 and Si2H6

    E-Print Network [OSTI]

    George, Steven M.

    Gas phase reaction products during tungsten atomic layer deposition using WF6 and Si2H6 R. K; published 23 July 2004 The gas phase reaction products during tungsten W atomic layer deposition ALD using WF6 and Si2H6 were studied using quadrupole mass spectrometry. The gas phase reactions products were

  4. Above: Power deposition in the superconducting magnets and the tungsten-carbide + water shield inside them, according to a

    E-Print Network [OSTI]

    McDonald, Kirk

    Above: Power deposition in the superconducting magnets and the tungsten-carbide + water shield FOR A MUON COLLIDER (TUP265, PAC11) The concept for a muon-production system for a muon collider (or neutrino Magnet shield WC beads + water Shield must dissipate 2.4 MW Superconducting magnets tungsten-carbide (WC

  5. Microstructure of laser-fired, sol-gel-derived tungsten oxide films

    SciTech Connect (OSTI)

    Taylor, D.J.; Birnie, D.P. III [Univ. of Arizona, Tucson, AZ (United States)] [Univ. of Arizona, Tucson, AZ (United States); Cronin, J.P. [Donnelly Corp., Tucson, AZ (United States)] [Donnelly Corp., Tucson, AZ (United States); Allard, L.F. Jr. [Oak Ridge National Lab, TN (United States)] [Oak Ridge National Lab, TN (United States)

    1996-07-01T23:59:59.000Z

    Half-micron-thick tungsten oxide films were deposited by the sol-gel method onto indium tin oxide (ITO) coated soda lime silicate substrates. Following a 100 {degrees}C prebake, the samples were fired with a carbon dioxide laser at a variety of power densities and translation speeds. The laser-fired tungsten oxide films were characterized by spectrophotometry, electrochemistry, multiangle ellipsometry, and transmission electron microscopy and compared to similar furnace-fired films. The data showed an increase in electrochromic response with increased firing temperature up to the point where crystallization of the tungsten oxide retarded electrochromic response. A window with graded electrochromic properties was made by laser firing. 35 refs., 8 figs., 1 tab.

  6. Micro-Raman and cathodoluminescence studies of epitaxial laterally overgrown GaN with tungsten masks: A method to map the free-carrier

    E-Print Network [OSTI]

    Nabben, Reinhard

    Micro-Raman and cathodoluminescence studies of epitaxial laterally overgrown GaN with tungsten properties of two epitaxial-laterally overgrown GaN structures with tungsten masks in 1100 and 1120 direction by tungsten masks3 to prevent the in-diffusion of silicon and oxygen atoms in the overgrown GaN, which

  7. A Tungsten(VI) Nitride Having a W2(-N)2 Core Zachary J. Tonzetich, Richard R. Schrock,* Keith M. Wampler, Brad C. Bailey,

    E-Print Network [OSTI]

    Müller, Peter

    A Tungsten(VI) Nitride Having a W2(µ-N)2 Core Zachary J. Tonzetich, Richard R. Schrock,* Keith M-331, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 Received September 27, 2007 The tungsten that the tungsten alkylidyne species W(C-t-Bu)(CH2-t-Bu)(OAr)2 (Ar ) 2,6-diisopropylphenyl) can be prepared readily

  8. Deuterium Depth Profile in Neutron-Irradiated Tungsten Exposed to Plasma

    SciTech Connect (OSTI)

    Masashi Shimada; G. Cao; Y. Hatano; T. Oda; Y. Oya; M. Hara; P. Calderoni

    2011-05-01T23:59:59.000Z

    The effect of radiation damage has been mainly simulated using high-energy ion bombardment. The ions, however, are limited in range to only a few microns into the surface. Hence, some uncertainty remains about the increase of trapping at radiation damage produced by 14 MeV fusion neutrons, which penetrate much farther into the bulk material. With the Japan-US joint research project: Tritium, Irradiations, and Thermofluids for America and Nippon (TITAN), the tungsten samples (99.99 % pure from A.L.M.T., 6mm in diameter, 0.2mm in thickness) were irradiated to high flux neutrons at 50 C and to 0.025 dpa in the High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL). Subsequently, the neutron-irradiated tungsten samples were exposed to a high-flux deuterium plasma (ion flux: 1021-1022 m-2s-1, ion fluence: 1025-1026 m-2) in the Tritium Plasma Experiment (TPE) at the Idaho National Laboratory (INL). First results of deuterium retention in neutron-irradiated tungsten exposed in TPE have been reported previously. This paper presents the latest results in our on-going work of deuterium depth profiling in neutron-irradiated tungsten via nuclear reaction analysis. The experimental data is compared with the result from non neutron-irradiated tungsten, and is analyzed with the Tritium Migration Analysis Program (TMAP) to elucidate the hydrogen isotope behavior such as retention and depth distribution in neutron-irradiated and non neutron-irradiated tungsten.

  9. Effect of silver incorporation in phase formation and band gap tuning of tungsten oxide thin films

    SciTech Connect (OSTI)

    Jolly Bose, R.; Kumar, R. Vinod; Sudheer, S. K.; Mahadevan Pillai, V. P. [Department of Optoelectronics, University of Kerala, Kariyavattom, Thiruvananthapuram, Kerala 695581 (India); Reddy, V. R.; Ganesan, V. [UGC - DAE Consortium for Scientific Research, Khandwa Road, Indore 452017, Madhyapradesh (India)

    2012-12-01T23:59:59.000Z

    Silver incorporated tungsten oxide thin films are prepared by RF magnetron sputtering technique. The effect of silver incorporation in micro structure evolution, phase enhancement, band gap tuning and other optical properties are investigated using techniques such as x-ray diffraction, micro-Raman spectroscopy, atomic force microscopy, scanning electron microscopy, energy dispersive x-ray spectroscopy, and UV-Visible spectroscopy. Effect of silver addition in phase formation and band gap tuning of tungsten oxide thin films are investigated. It is found that the texturing and phase formation improves with enhancement in silver content. It is also found that as the silver incorporation enhances the thickness of the films increases at the same time the strain in the film decreases. Even without annealing the desired phase can be achieved by doping with silver. A broad band centered at the wavelength 437 nm is observed in the absorption spectra of tungsten oxide films of higher silver incorporation and this can be attributed to surface plasmon resonance of silver atoms present in the tungsten oxide matrix. The transmittance of the films is decreased with increase in silver content which can be due to increase in film thickness, enhancement of scattering, and absorption of light caused by the increase of grain size, surface roughness and porosity of films and enhanced absorption due to surface plasmon resonance of silver. It is found that silver can act as the seed for the growth of tungsten oxide grains and found that the grain size increases with silver content which in turn decreases the band gap of tungsten oxide from 3.14 eV to 2.70 eV.

  10. Comparison of Deuterium Retention for Ion-irradiated and Neutron-irradiated Tungsten

    SciTech Connect (OSTI)

    Yasuhisa Oya; Masashi Shimada; Makoto Kobayashi; Takuji Oda; Masanori Hara; Hideo Watanabe; Yuji Hatano; Pattrick Calderoni; Kenji Okuno

    2011-12-01T23:59:59.000Z

    The behavior of D retention for Fe{sup 2+}-irradiated tungsten with a damage of 0.025-3 dpa was compared with that for neutron-irradiated tungsten with 0.025 dpa. The D{sub 2} thermal desorption spectroscopy (TDS) spectra for Fe{sup 2+}-irradiated tungsten consisted of two desorption stages at 450 and 550 K, while that for neutron-irradiated tungsten was composed of three stages and an addition desorption stage was found at 750 K. The desorption rate of the major desorption stage at 550K increased as the displacement damage increased due to Fe{sup 2+} irradiation increasing. In addition, the first desorption stage at 450K was found only for damaged samples. Therefore, the second stage would be based on intrinsic defects or vacancy produced by Fe{sup 2+} irradiation, and the first stage should be the accumulation of D in mono-vacancy and the activation energy would be relatively reduced, where the dislocation loop and vacancy is produced. The third one was found only for neutron irradiation, showing the D trapping by a void or vacancy cluster, and the diffusion effect is also contributed to by the high full-width at half-maximum of the TDS spectrum. Therefore, it can be said that the D{sub 2} TDS spectra for Fe{sup 2+}-irradiated tungsten cannot represent that for the neutron-irradiated one, indicating that the deuterium trapping and desorption mechanism for neutron-irradiated tungsten is different from that for the ion-irradiated one.

  11. Utilization of geothermal energy in the mining and processing of tungsten ore. Quarterly report

    SciTech Connect (OSTI)

    Lane, C.K.; Erickson, M.V.; Lowe, G.D.

    1980-02-01T23:59:59.000Z

    The status of the engineering and economic feasibility study of utilizing geothermal energy for the mining and processing of tungsten ore at the Union Carbide-Metals Division Pine Creek tungsten complex near Bishop, Calfironia is reviewed. Results of geophysical data analysis including determination of assumed resource parameters are presented. The energy utilization evaluation identifies potential locations for substituting geothermal energy for fossil fuel energy using current technology. Preliminary analyses for local environmental and institutional barriers to development of a geothermal system are also provided.

  12. Measurements of Nucleon-Induced Fission Cross-Sections of Separated Tungsten Isotopes and Natural Tungsten in the 50-200 MeV Energy Region

    E-Print Network [OSTI]

    V. P. Eismont; N. P. Filatov; A. N. Smirnov; S. M. Soloviev; J. Blomgren; H. Conde; A. V. Prokofiev; S. G. Mashnik

    2005-07-07T23:59:59.000Z

    Neutron- and proton-induced fission cross-sections of separated isotopes of tungsten (182W, 183W, 184W, and 186W) and natural tungsten relative to 209Bi have been measured in the incident nucleon energy region 50-200 MeV using fission chambers based on thin-film breakdown counters (TFBC) at quasi-monoenergetic neutrons from the 7Li(p,n) reaction and at the proton beams of The Svedberg Laboratory (TSL), Uppsala University (Uppsala, Sweden). The preliminary experimental data are presented in comparison with the recent data for nuclei in the lead-bismuth region, as well as with predictions by the CEM03.01 event generator.

  13. Theoretic Insight into CO2 Reduction at Active Sites of Molybdenum and Tungsten Enzymes: a {\\pi} Interaction between CO2 and Tungsten Bis-Dithiolene Complexes

    E-Print Network [OSTI]

    Yan, Yong

    2014-01-01T23:59:59.000Z

    Active sites of molybdenum and tungsten enzymes, particularly mononuclear tungsten formate dehydrogenase (FDH) have been theoretically investigated towards their interaction with CO2. Obvious {\\pi} interaction has been found between the 2e reduced metallodithiole moiety and the molecular CO2. This weak {\\pi} bonding is predicated both at gas phase, noted as -6.0 kcal/mol and aqueous solvation level, -3.6 kcal/mol. Such interaction is not only limited to CO2, but also to the CO2 reduced product, i.e. formate, in the form of anion- {\\pi} interaction, noted as -6.8 kcal/mol and -4.1 kcal/mol respectively in gas and aqueous solvation model. The Bailar twisted angles from 60o to 0o, governing structure preference of tungsten dithiolene from octahedron to triangle prism in their restricted structures, has been explored to evaluate such {\\pi} in-terrelations with CO2 and formate. An octahedral structure with 3 kcal/mol energy lower is preferred over the triangle prismatic when such interactions are concerned.

  14. Abstract--This paper deals with halogen luminaries, ones of the main used lighting sources in residential area. The use of these

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    power systems were performed to show the accuracy of developed models. Index Terms--halogen lamp, EMTP is with Schneider Electric Industries (Business Unit Power ­ Systems and Mechatronic Integration), 31 Pierre Mendes and the LV power systems. But studies regarding the power up problem of electrical lighting systems where ETs

  15. Spectroscopic Signatures of Halogens in Clathrate Hydrate Cages. 1. Bromine Galina Kerenskaya,* Ilya U. Goldschleger, V. Ara Apkarian, and Kenneth C. Janda

    E-Print Network [OSTI]

    Apkarian, V. Ara

    , the earliest gas clathrate hydrate discovered, was first prepared by Davy in 1811;1 bromine hydrateSpectroscopic Signatures of Halogens in Clathrate Hydrate Cages. 1. Bromine Galina Kerenskaya report the first UV-vis spectroscopic study of bromine molecules confined in clathrate hydrate cages

  16. Transient Thermal and Stress Response of A Helium-Cooled Tungsten Plate-Type Divertor

    E-Print Network [OSTI]

    Raffray, A. René

    Transient Thermal and Stress Response of A Helium- Cooled Tungsten Plate-Type Divertor X.R. Wang, A and shutdown operations have been analyzed with a coupled transient thermo-fluid and thermal-stress approach and investigated for power plant applications with a goal of accommodating a heat flux of 10 MW/m2 . The concepts

  17. Tungsten uptake kinetics and trophic1 transfer into a novel gastropod model2

    E-Print Network [OSTI]

    Ma, Lena

    exploration of its relevant environmental and biological pathways. This investigation presents the most7 some27 siderophilic tendencies that are very similar to uranium and thorium, and which have similar it a unique29 element. Tungsten has one of the greatest densities (19.25 g/cm3 ), after only uranium

  18. Submersion Criticality Safety Analysis of Tungsten-Based Fuel for Nuclear Power and Propulsion Applications

    SciTech Connect (OSTI)

    A.E. Craft; R. C. O'Brien; S. D. Howe; J. C. King

    2014-07-01T23:59:59.000Z

    The Center for Space Nuclear Research (CSNR) is developing tungsten-encapsulated fuels for space nuclear applications. Aims to develop NTP fuels that are; Affordable Low impact on production and testing environment Producible on a large scale over suitable time period Higher-performance compared to previous graphite NTP fuel elements Space nuclear reactors remain subcritical before and during launch, and do not go critical until required by its mission. A properly designed reactor will remain subcritical in any launch abort scenario, where the reactor falls back to Earth and becomes submerged in terrestrial material. Submersion increases neutron reflection and thermalizes the neutrons, which typically increases the reactivity of the core. This effect is usually very significant for fast-spectrum reactors. This research provided a submersion criticality safety analysis for a representative tungsten/uranium oxide fueled reactor. Determine the submersion behavior of a reactor fueled by tungsten-based fuel. Considered fuel compositions with varying: Rhenium content (wt% rhenium in tungsten) Fuel loading fractions (UO2 vol%)

  19. Micro-engineered first wall tungsten armor for high average power laser fusion energy systems

    E-Print Network [OSTI]

    Ghoniem, Nasr M.

    Micro-engineered first wall tungsten armor for high average power laser fusion energy systems is developing an inertial fusion energy demonstration power reactor with a solid first wall chamber. The first is a coordinated effort to develop laser inertial fusion energy [1]. The first stage of the HAPL program

  20. ULTRA LOW PRESSURE-DROP HELIUM-COOLED POROUS-TUNGSTEN PFC S. Sharafat1

    E-Print Network [OSTI]

    Ghoniem, Nasr M.

    ULTRA LOW PRESSURE-DROP HELIUM-COOLED POROUS-TUNGSTEN PFC S. Sharafat1 , A. Mills1 , D. Youchison2/s. Based on these impressive performance results, a unique and scalable heat exchanger channel with ultra-low and ultra low-pressure drop short flow-path (SOFIT) concept was designed. Typical pressure drops through

  1. Laminated electrochromic windows based on nickel oxide, tungsten oxide, and gel electrolytes

    SciTech Connect (OSTI)

    Passerini, S.; Scrosati, B.; Hermann, V. (Univ. di Roma (Italy). Dipt. di Chimica); Holmblad, C.; Bartlett, T. (Medtronic Promeon, Minneapolis, MN (United States))

    1994-04-01T23:59:59.000Z

    The characteristic and the performance of solid-state, laminated electrochromic windows using tungsten oxide as the principal electrochromic electrode and nonstoichiometric nickel oxide as the counterelectrode separated by selected gel electrolytes, are presented and discussed. These advanced-design, electro-optical devices show a very promising behavior in terms of light modulation and cyclability.

  2. Helium Jet-Cooled Tungsten Divertor Concept J.S. O'Della

    E-Print Network [OSTI]

    Raffray, A. René

    Helium Jet-Cooled Tungsten Divertor Concept J.S. O'Della and A.R. Raffrayb a Plasma Processes, Inc., Huntsville, Alabama, USA b University of California ­ San Diego, La Jolla, California, USA Abstract-- Helium helium cooling techniques for high heat flux (HHF) applications. However, because of the small size

  3. The role of helium implantation induced vacancy defect on hardening of tungsten

    SciTech Connect (OSTI)

    Ou, Xin, E-mail: x.ou@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); State Key Laboratory of Functional Material for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200250 (China); Anwand, Wolfgang, E-mail: w.anwand@hzdr.de; Kögler, Reinhard, E-mail: r.koegler@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); Zhou, Hong-Bo [Department of Physics, Beihang University, Beijing 100191 (China); Richter, Asta, E-mail: asta.richter@th-wildau.de [Technische Hochschule Wildau, Hochschulring1, 15745 Wildau (Germany)

    2014-03-28T23:59:59.000Z

    Vacancy-type defects created by helium implantation in tungsten and their impact on the nano-hardness characteristics were investigated by correlating the results from the positron annihilation spectroscopy and the nano-indentation technique. Helium implantation was performed at room temperature (RT) and at an elevated temperate of 600?°C. Also, the effect of post-annealing of the RT implanted sample was studied. The S parameter characterizing the open volume in the material was found to increase after helium irradiation and is significantly enhanced for the samples thermally treated at 600?°C either by irradiation at high temperature or by post-annealing. Two types of helium-vacancy defects were detected after helium irradiation; small defects with high helium-to-vacancy ratio (low S parameter) for RT irradiation and large defects with low helium-to-vacancy ratio (high S parameter) for thermally treated tungsten. The hardness of the heat treated tungsten coincides with the S parameter, and hence is controlled by the large helium-vacancy defects. The hardness of tungsten irradiated at RT without thermal treatment is dominated by manufacturing related defects such as dislocation loops and impurity clusters and additionally by trapped He atoms from irradiation effects, which enhance hardness. He-stabilized dislocation loops mainly cause the very high hardness values in RT irradiated samples without post-annealing.

  4. Interactions of mobile helium clusters with surfaces and grain boundaries of plasma-exposed tungsten

    SciTech Connect (OSTI)

    Hu, Lin; Maroudas, Dimitrios, E-mail: maroudas@ecs.umass.edu [Department of Chemical Engineering, University of Massachusetts, Amherst, Massachusetts 01003-9303 (United States); Hammond, Karl D.; Wirth, Brian D. [Department of Nuclear Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States)

    2014-05-07T23:59:59.000Z

    We report results of atomistic computations for the interactions of small mobile helium clusters (He{sub n}) with free surfaces and grain boundaries (GBs) in tungsten toward development of continuum drift-diffusion-reaction models for the dynamics of mobile helium clusters in plasma-exposed tungsten. Molecular-statics (MS) simulations based on reliable many-body interatomic potentials are carried out for He{sub n} (1???n???7) clusters near sinks to obtain the potential energy profiles of the He{sub n} clusters as a function of the clusters' center-of-mass distance from a sink. Sinks investigated include surfaces, GBs, and regions in the vicinity of junctions where GBs intersect free surfaces. Elastic interaction potentials based on elastic inclusion theory provide an excellent description of the MS results for the cluster-sink interactions. The key parameter in the elastic models is the sink segregation strength, which is found to increase with increasing cluster size. Such cluster-sink interactions are responsible for the migration of small helium clusters by drift and for helium segregation on surfaces and grain boundaries in tungsten. Such helium segregation on sinks is observed in large-scale molecular-dynamics simulations of helium aggregation in model polycrystalline tungsten at 933?K upon helium implantation.

  5. Materials Corrosion and Mitigation Strategies for APT: Using Solution Resistivity as an Estimate of Tungsten Corrosion

    E-Print Network [OSTI]

    Materials Corrosion and Mitigation Strategies for APT: Using Solution Resistivity as an Estimate of Tungsten Corrosion in Spallation Neutron Target Cooling Loops R. Scott Lillard, Darryl P. Butt Materials Corrosion and Environmental Effects Laboratory MST-6, Metallurgy Los Alamos National Laboratory Los Alamos

  6. Tungsten nano-tendril growth in the Alcator C-Mod divertor

    E-Print Network [OSTI]

    Baldwin, M.J.

    Growth of tungsten nano-tendrils ('fuzz') has been observed for the first time in the divertor region of a high-power density tokamak experiment. After 14 consecutive helium L-mode discharges in Alcator C-Mod, the tip of ...

  7. Utilization of geothermal energy in the mining and processing of tungsten ore. Final report

    SciTech Connect (OSTI)

    Erickson, M.V.; Lacy, S.B.; Lowe, G.D.; Nussbaum, A.M.; Walter, K.M.; Willens, C.A.

    1981-01-01T23:59:59.000Z

    The engineering, economic, and environmental feasibility of the use of low and moderate temperature geothermal heat in the mining and processing of tungsten ore is explored. The following are covered: general engineering evaluation, design of a geothermal energy system, economics, the geothermal resource, the institutional barriers assessment, environmental factors, an alternate geothermal energy source, and alternates to geothermal development. (MHR)

  8. Defect production in tungsten: A comparison between field-ion microscopy and molecular-dynamics simulations

    E-Print Network [OSTI]

    Nordlund, Kai

    Defect production in tungsten: A comparison between field-ion microscopy and molecular defect production efficiencies obtained by FIM are a consequence of a surface effect, which greatly enhances defect production compared to that in the crystal interior. Comparison of clustering of vacancies

  9. MODELING SPACE-TIME DEPENDENT HELIUM BUBBLE EVOLUTION IN TUNGSTEN ARMOR UNDER IFE CONDITIONS

    E-Print Network [OSTI]

    Ghoniem, Nasr M.

    MODELING SPACE-TIME DEPENDENT HELIUM BUBBLE EVOLUTION IN TUNGSTEN ARMOR UNDER IFE CONDITIONS Qiyang dependent Helium transport in finite geometries, including the simultaneous transient production of defects of Helium bubbles. I. INTRODUCTION Helium production and helium bubble evolution in neutron

  10. SPS Fabrication of Tungsten-Rhenium Alloys in Support of NTR Fuels Development

    SciTech Connect (OSTI)

    Jonathan A. Webb; Indrajit Charit; Cory Sparks; Darryl P. Butt; Megan Frary; Mark Carroll

    2011-02-01T23:59:59.000Z

    Abstract. Tungsten metal slugs were fabricated via Spark Plasma Sintering (SPS) of powdered metals at temperatures ranging from 1575 K to 1975 K and hold times of 5 minutes to 30 minutes, using powders with an average diameter of 7.8 ?m. Sintered tungsten specimens were found to have relative densities ranging from 83 % to 94 % of the theoretical density for tungsten. Consolidated specimens were also tested for their Vickers Hardness Number (VHN), which was fitted as a function of relative density; the fully consolidated VHN was extrapolated to be 381.45 kg/mm2. Concurrently, tungsten and rhenium powders with average respective diameters of 0.5 ?m and 13.3 ?m were pre-processed either by High-Energy-Ball-Milling (HEBM) or by homogeneous mixing to yield W-25at.%Re mixtures. The powder batches were sintered at temperatures of 1975 K and 2175 K for hold times ranging from 0 minutes to 60 minutes yielding relative densities ranging from 94% to 97%. The combination of HEBM and sintering showed a significant decrease in the inter-metallic phases compared to that of the homogenous mixing and sintering.

  11. Impacts of halogen additions on mercury oxidation, in a slipstream selective catalyst reduction (SCR), reactor when burning sub-bituminous coal

    SciTech Connect (OSTI)

    Yan Cao; Zhengyang Gao; Jiashun Zhu; Quanhai Wang; Yaji Huang; Chengchung Chiu; Bruce Parker; Paul Chu; Wei-ping Pan [Western Kentucky University (WKU), Bowling Green, KY (United States). Institute for Combustion Science and Environmental Technology (ICSET)

    2008-01-01T23:59:59.000Z

    This paper presents a comparison of impacts of halogen species on the elemental mercury (Hg(0)) oxidation in a real coal-derived flue gas atmosphere. It is reported there is a higher percentage of Hg(0) in the flue gas when burning sub-bituminous coal (herein Powder River Basin (PRB) coal) and lignite, even with the use of selective catalytic reduction (SCR). The higher Hg(0) concentration in the flue gas makes it difficult to use the wet-FGD process for the mercury emission control in coal-fired utility boilers. Investigation of enhanced Hg(0) oxidation by addition of hydrogen halogens (HF, HCl, HBr, and HI) was conducted in a slipstream reactor with and without SCR catalysts when burning PRB coal. Two commercial SCR catalysts were evaluated. SCR catalyst no. 1 showed higher efficiencies of both NO reduction and Hg(0) oxidation than those of SCR catalyst no. 2. NH{sub 3} addition seemed to inhibit the Hg(0) oxidation, which indicated competitive processes between NH{sub 3} reduction and Hg(0) oxidation on the surface of SCR catalysts. The hydrogen halogens, in the order of impact on Hg(0) oxidation, were HBr, HI, and HCl or HF. Addition of HBr at approximately 3 ppm could achieve 80% Hg(0) oxidation. Addition of HI at approximately 5 ppm could achieve 40% Hg(0) oxidation. In comparison to the empty reactor, 40% Hg(0) oxidation could be achieved when HCl addition was up to 300 ppm. The enhanced Hg(0) oxidation by addition of HBr and HI seemed not to be correlated to the catalytic effects by both evaluated SCR catalysts. The effectiveness of conversion of hydrogen halogens to halogen molecules or interhalogens seemed to be attributed to their impacts on Hg(0) oxidation. 30 refs., 4 figs.

  12. Defect annealing and thermal desorption of deuterium in low dose HFIR neutron-irradiated tungsten

    SciTech Connect (OSTI)

    Masashi Shimada; M. Hara; T. Otsuka; Y. Oya; Y. Hatano

    2014-05-01T23:59:59.000Z

    Accurately estimating tritium retention in plasma facing components (PFCs) and minimizing its uncertainty are key safety issues for licensing future fusion power reactors. D-T fusion reactions produce 14.1 MeV neutrons that activate PFCs and create radiation defects throughout the bulk of the material of these components. Recent studies show that tritium migrates and is trapped in bulk (>> 10 µm) tungsten beyond the detection range of nuclear reaction analysis technique [1-2], and thermal desorption spectroscopy (TDS) technique becomes the only established diagnostic that can reveal hydrogen isotope behavior in in bulk (>> 10 µm) tungsten. Radiation damage and its recovery mechanisms in neutron-irradiated tungsten are still poorly understood, and neutron-irradiation data of tungsten is very limited. In this paper, systematic investigations with repeated plasma exposures and thermal desorption are performed to study defect annealing and thermal desorption of deuterium in low dose neutron-irradiated tungsten. Three tungsten samples (99.99 at. % purity from A.L.M.T. Co., Japan) irradiated at High Flux Isotope Reactor at Oak Ridge National Laboratory were exposed to high flux (ion flux of (0.5-1.0)x1022 m-2s-1 and ion fluence of 1x1026 m-2) deuterium plasma at three different temperatures (100, 200, and 500 °C) in Tritium Plasma Experiment at Idaho National Laboratory. Subsequently, thermal desorption spectroscopy (TDS) was performed with a ramp rate of 10 °C/min up to 900 °C, and the samples were annealed at 900 °C for 0.5 hour. These procedures were repeated three (for 100 and 200 °C samples) and four (for 500 °C sample) times to uncover damage recovery mechanisms and its effects on deuterium behavior. The results show that deuterium retention decreases approximately 90, 75, and 66 % for 100, 200, and 500 °C, respectively after each annealing. When subjected to the same TDS recipe, the desorption temperature shifts from 800 °C to 600 °C after 1st annealing for the sample exposed to TPE at 500 °C. Tritium Migration Analysis Program (TMAP) analysis reveals that the detrapping energy decreases from 1.8 eV to 1.4 eV, indicating the changes in trapping mechanisms. This paper also summarizes deuterium behavior studies in HFIR neutron-irradiated tungsten under US-Japan TITAN program.

  13. Molecules in the Spotlight

    SciTech Connect (OSTI)

    Cryan, James

    2010-01-26T23:59:59.000Z

    SLAC has just unveiled the world's first X-ray laser, the LCLS. This machine produces pulses of X-rays that are ten billion times brighter than those from conventional sources. One of the goals of this machine is to make movies of chemical reactions, including reactions necessary for life and reactions that might power new energy technologies. This public lecture will show the first results from the LCLS. As a first target, we have chosen nitrogen gas, the main component of the air we breathe. Using the unprecedented power of the LCLS X-rays as a blasting torch, we have created new forms of this molecule and with unique electronic arrangements. Please share with us the first insights from this new technology.

  14. MEISPP Internship Spotlight

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

    of academic majors, such as economics, business, international relations, biology, physics, engineering, etc. All internships include paid lodging; roundtrip airfare;...

  15. Spotlight, September 2012

    E-Print Network [OSTI]

    2012-09-01T23:59:59.000Z

    boom early in the 20th century relegated the bicycle to the role of an expensive toy, generally for recreational use only. Recently, however, the hike in gas prices, the rise in public awareness of sustainable living and need for exercise... how much ends up in the landfill. Trash to Treasure By Meredith Walrafen, Center for Sustainability Intern Intern Meredith Walrafen in front of one of the many roll-off dumpsters used in Lawrence during move-out times. 4 Page 4 KU Center...

  16. Spotlight, August 2012

    E-Print Network [OSTI]

    2012-08-01T23:59:59.000Z

    August 2012 Page 1 KU Center for Sustainability Hertz on Demand also helps save the environment while saving its members money, by lessening harmful emissions and reducing congestion. Fewer cars on the road means lower CO2 emissions.... Sustainable practices were evident in other areas as well. Solar panels were put wherever they could fit to make the most of an often evasive sun, as clouds and rain became a normalcy. Touring a local organic winery meshed the initiatives of a...

  17. DOE Sustainability SPOtlight

    Broader source: Energy.gov [DOE]

    Newsletter highlights the recipients of the U.S. Department of Energy (DOE) Sustainability Performance Office (SPO) 2014 Sustainability Awards.

  18. Employee Spotlight: Ann Schlenker

    SciTech Connect (OSTI)

    Ann Schlenker

    2013-03-20T23:59:59.000Z

    Ann Schlenker, Director for the Center for Transportation Research, discusses mentoring and working at Argonne.

  19. Spotlight, June 2012

    E-Print Network [OSTI]

    2012-06-01T23:59:59.000Z

    notice. The Biofuels and Climate Change: Farmers’ Land Use Decisions (BACC:FLUD) project has brought together an inter-disciplinary team of researchers from The University of Kansas, Kansas State University, and Emporia State University... policies that promote or restrain certain land uses; and economic factors, such as food crop prices and biofuel crop prices. These data sets will be integrated with data from other sources into a rich, longitudinal database on land use decisions...

  20. Spotlight, November 2012

    E-Print Network [OSTI]

    2012-11-01T23:59:59.000Z

    - and water-use decisions in a changing climate,” highlighting elements of the Biofuels and Climate Change: Farmers' Land Use Decisions (BACC: FLUD) project. Engineering faculty and others across multiple social and natural science disciplines from... both KU and K-State are working on this collaborative project researching farmers’ decisions to grow biofuel crops as feedstocks for renewable energy production and their adaptation to climate change. Dr. Sturm’s focus was on irrigation demands...

  1. Spotlight, October 2012

    E-Print Network [OSTI]

    2012-10-01T23:59:59.000Z

    is June 2014. Transportation: Our Transit system uses hybrid buses along its busiest routes, and we’re piloting a compressed natural gas vehicle to By Eileen Horn, Lawrence/Douglas County Sustainability Coordinator learn more about this alternative...

  2. Spotlight, May 2013

    E-Print Network [OSTI]

    2013-05-01T23:59:59.000Z

    landscape management with a high level of diversity and practices that include maintenance and enhancement of soil carbon stocks, best practices for water-use efficiency, and integrated nutrient management through livestock manure, green manure... that are no longer needed, or just won't fit in truck of their car. The Center for Sustainability, along with KU Surplus and KU Recycling, are helping to find new homes for many of these items and continue the 3 R's cycle. This year, the Center will be working...

  3. Employee Spotlight: Ann Schlenker

    ScienceCinema (OSTI)

    Ann Schlenker

    2013-06-10T23:59:59.000Z

    Ann Schlenker, Director for the Center for Transportation Research, discusses mentoring and working at Argonne.

  4. Robot learning [TC Spotlight

    E-Print Network [OSTI]

    Tedrake, Russell Louis

    Creating autonomous robots that can learn to act in unpredictable environments has been a long-standing goal of robotics, artificial intelligence, and the cognitive sciences. In contrast, current commercially available ...

  5. Spotlight, April 2012

    E-Print Network [OSTI]

    2012-04-01T23:59:59.000Z

    Oread. The board hopes to revive this tradition by working with students on annual planting and tree inventory projects. Students fro m the Enviro nmental Law Society help plant a redb ud tree. Sou rce: KU Scho ol of Law. You can help fund...: Sarah Link Left: Garbage - mostly plastic - accumulates on the Damon Slough Beach in Oakland, CA. Right: Manuel Mansylla from Plastic Pollution Coalition displays the plastic waste he collected in about an hour at the beach. Source: Sarah Link...

  6. Spotlight, April 2013

    E-Print Network [OSTI]

    2013-04-01T23:59:59.000Z

    to turn off all lights and appliances when they leave a room, and plan to conduct an energy audit to analyze the effectiveness of this program. In addition, Sigma Phi Epsilon has taken environmental consideration in every facility upgrade made.... She was a founder and chairperson of the Lawrence Community Environmental School charter, a co-founder of the Lawrence Environmental Education Project, an organizer for the Ecoliteracy Book Club in Lawrence, coordinator for the St. John school...

  7. Spotlight, March 2013

    E-Print Network [OSTI]

    2013-03-01T23:59:59.000Z

    to reduce environmental impacts and create a more sustainable workplace. Participants in the program must complete an application that identifies specific actions their offices are taking. The list includes strategies for cutting energy consumption..., reducing waste and making environmentally preferable purchases. Green 4 Page 4 KU Center for Sustainability March 2013 Last year’s competition led to a combined energy savings of 14.3%, and was equivalent to the electric use of 10.4 homes for a...

  8. Employee Spotlight: Alessandro Cattaneo

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign:INEAWater UseCElizabethTwo StatesEmployeeHumanAlessandro

  9. Employee Spotlight: Bryant Roybal

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign:INEAWater UseCElizabethTwo StatesEmployeeHumanAlessandroBryant

  10. Employee Spotlight: Dave Keller

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign:INEAWater UseCElizabethTwo

  11. Employee Spotlight: Janice Lovato

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign:INEAWater UseCElizabethTwoJanice Lovato March 10, 2015 A gift

  12. Employee Spotlight: Jonathan Engle

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign:INEAWater UseCElizabethTwoJanice Lovato March 10, 2015 A

  13. Employee Spotlight: Kristen Honig

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign:INEAWater UseCElizabethTwoJanice Lovato March 10, 2015

  14. Employee Spotlight: Michael Torrez

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign:INEAWater UseCElizabethTwoJanice Lovato March 10, 2015Michael

  15. Employee Spotlight: Monika Bittman

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign:INEAWater UseCElizabethTwoJanice Lovato March 10,

  16. Employee Spotlight: Ron Barber

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power AdministrationField Campaign:INEAWater UseCElizabethTwoJanice Lovato March 10,Ron Barber

  17. Scientists in the Spotlight

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiationImplementingnpitcheResearchPhysics Lab Scientist's

  18. Scientists in the Spotlight

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiationImplementingnpitcheResearchPhysics Lab Scientist'sScientists in the

  19. Scientists in the Spotlight

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiationImplementingnpitcheResearchPhysics Lab Scientist'sScientists in theScientists

  20. Scientists in the Spotlight

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiationImplementingnpitcheResearchPhysics Lab Scientist'sScientists in

  1. Scientists in the Spotlight

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's PossibleRadiationImplementingnpitcheResearchPhysics Lab Scientist'sScientists inScientists In

  2. Employee Spotlight: Alessandro Cattaneo

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContractElectron-State HybridizationSecurity /MaterialsPKGWhereAlessandro

  3. Employee Spotlight: Bryant Roybal

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContractElectron-State HybridizationSecurity

  4. Employee Spotlight: Dave Keller

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContractElectron-State HybridizationSecurityDave Keller Dave Keller-Sleepless

  5. Employee Spotlight: Janice Lovato

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContractElectron-State HybridizationSecurityDave Keller Dave

  6. Employee Spotlight: Jason Halladay

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContractElectron-State HybridizationSecurityDave Keller DaveCareer Jobs»

  7. Employee Spotlight: Jonathan Engle

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContractElectron-State HybridizationSecurityDave Keller DaveCareer Jobs»Jon

  8. Employee Spotlight: Kristen Honig

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContractElectron-State HybridizationSecurityDave Keller DaveCareerKristen

  9. Employee Spotlight: Michael Torrez

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContractElectron-State HybridizationSecurityDave Keller

  10. Employee Spotlight: Michelle Ferran

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContractElectron-State HybridizationSecurityDave KellerCareer Jobs» Career

  11. Employee Spotlight: Monika Bittman

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContractElectron-State HybridizationSecurityDave KellerCareer Jobs»

  12. Employee Spotlight: Ron Barber

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContractElectron-State HybridizationSecurityDave KellerCareer Jobs»Ron Barber

  13. Employee Spotlight: Sim Balkey

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadapInactiveVisitingContractElectron-State HybridizationSecurityDave KellerCareer Jobs»Ron

  14. Influence of process parameters on properties of reactively sputtered tungsten nitride thin films

    SciTech Connect (OSTI)

    Addonizio, Maria L.; Castaldo, Anna; Antonaia, Alessandro; Gambale, Emilia; Iemmo, Laura [ENEA, Portici Research Centre, Piazzale E. Fermi 1, I-80055, Portici (Italy)

    2012-05-15T23:59:59.000Z

    Tungsten nitride (WN{sub x}) thin films were produced by reactive dc magnetron sputtering of tungsten in an Ar-N{sub 2} gas mixture. The influence of the deposition power on the properties of tungsten nitride has been analyzed and compared with that induced by nitrogen content variation in the sputtering gas. A combined analysis of structural, electrical and optical properties on thin WN{sub x} films obtained at different deposition conditions has been performed. It was found that at an N{sub 2} content of 14% a single phase structure of W{sub 2}N films was formed with the highest crystalline content. This sputtering gas composition was subsequently used for fabricating films at different deposition powers. Optical analysis showed that increasing the deposition power created tungsten nitride films with a more metallic character, which is confirmed with resistivity measurements. At low sputtering powers the resulting films were crystalline whereas, with an increase of power, an amorphous phase was also present. The incorporation of an excess of nitrogen atoms resulted in an expansion of the W{sub 2}N lattice and this effect was more pronounced at low deposition powers. Infrared analysis revealed that in WN{sub x} films deposited at low power, chemisorbed N{sub 2} molecules did not behave as ligands whereas at high deposition power they clearly appeared as ligands around metallic tungsten. In this study, the influence of the most meaningful deposition parameters on the phase transformation reaction path was established and deposition conditions suitable for producing thermally stable and highly crystalline W{sub 2}N films were found.

  15. Evaporation-assisted high-power impulse magnetron sputtering: The deposition of tungsten oxide as a case study

    SciTech Connect (OSTI)

    Hemberg, Axel; Dauchot, Jean-Pierre; Snyders, Rony; Konstantinidis, Stephanos [Materia Nova Research Center-Parc Initialis, 1, Avenue Copernic, B-7000 Mons, Belgium and Chimie des Interactions Plasma-Surface, CIRMAP, Universite de Mons-20, Place du Parc, B-7000 Mons (Belgium); Chimie des Interactions Plasma-Surface, CIRMAP, Universite de Mons-20, Place du Parc, B-7000 Mons (Belgium); Materia Nova Research Center-Parc Initialis, 1, Avenue Copernic, B-7000 Mons (Belgium) and Chimie des Interactions Plasma-Surface, CIRMAP, Universite de Mons-20, Place du Parc, B-7000 Mons (Belgium); Chimie des Interactions Plasma-Surface, CIRMAP, Universite de Mons-20, Place du Parc, B-7000 Mons (Belgium)

    2012-07-15T23:59:59.000Z

    The deposition rate during the synthesis of tungsten trioxide thin films by reactive high-power impulse magnetron sputtering (HiPIMS) of a tungsten target increases, above the dc threshold, as a result of the appropriate combination of the target voltage, the pulse duration, and the amount of oxygen in the reactive atmosphere. This behavior is likely to be caused by the evaporation of the low melting point tungsten trioxide layer covering the metallic target in such working conditions. The HiPIMS process is therefore assisted by thermal evaporation of the target material.

  16. Detection and Differentiation of Neutral Organic Compounds by [superscript 19]F NMR with a Tungsten Calix[4]arene Imido Complex

    E-Print Network [OSTI]

    Zhao, Yanchuan

    Fluorinated tungsten calix[4]arene imido complexes were synthesized and used as receptors to detect and differentiate neutral organic compounds. It was found that the binding of specific neutral organic molecules to the ...

  17. Chapter 30: Quantum Physics 9. The tungsten filament in a standard light bulb can be considered a blackbody radiator.

    E-Print Network [OSTI]

    Kioussis, Nicholas

    . 1 Chapter 30: Quantum Physics 9. The tungsten filament in a standard light bulb can be considered frequency is that of infrared electromagnetic radiation, the light bulb radiates more energy in the infrared

  18. Z-Selective Metathesis Homocoupling of 1,3-Dienes by Molybdenum and Tungsten Monoaryloxide Pyrrolide (MAP) Complexes

    E-Print Network [OSTI]

    Hoveyda, Amir H.

    Molybdenum or tungsten monoaryloxide pyrrolide (MAP) complexes that contain OHIPT as the aryloxide (hexaisopropylterphenoxide) are effective catalysts for homocoupling of simple (E)-1,3-dienes to give (E,Z,E)-trienes in ...

  19. Use of nafion as a solid polymer electrolyte for the electroreduction of tungsten (VI) fluoride

    SciTech Connect (OSTI)

    Bettelheim, A.; Raven, A.; Polak, M.; Ozer, D. (Nuclear Research Center, Beer-Sheva 84190 (IL))

    1992-01-01T23:59:59.000Z

    In this paper a new method is described in which WF{sub 6} is electroreduced in a solid-state cell configuration with a Nafion membrane serving as a solid polymer electrolyte. Cyclic voltammetry indicates a behavior similar to that of metallic tungsten for coatings obtained at dry conditions and similar to that of tungsten oxide species when water vapor is not totally expelled. Surface analysis using Auger electroscope and x-ray photoelectron spectroscopy shows that solid-state electro-reduction of WF{sub 6} in dry conditions yields coatings free of fluorine, which contain much less oxygen than electrodeposits obtained from aqueous solutions. However, due to possible oxidation and reduction reactions occurring before and during the surface-analysis process, it is not possible at this state to determine the exact content of metallic and oxide species in the deposits obtained by the present method.

  20. Test and characterization of a prototype silicon-tungsten electromagnetic calorimeter

    E-Print Network [OSTI]

    Sanjib Muhuri; Sourav Mukhopadhyay; Vinay B. Chandratre; Menka Sukhwani; Satyajit Jena; Shuaib Ahmad Khan; Tapan K. Nayak; Jogender Saini; Rama Narayana Singaraju

    2014-07-22T23:59:59.000Z

    New generation high-energy physics experiments demand high precision tracking and accurate measurements of a large number of particles produced in the collisions of lementary particles and heavy-ions. Silicon-tungsten (Si-W) calorimeters provide the most viable technological option to meet the requirements of particle detection in high multiplicity environments. We report a novel Si-W calorimeter design, which is optimized for $\\gamma/\\pi^0$ discrimination up to high momenta. In order to test the feasibility of the calorimeter, a prototype mini-tower was constructed using silicon pad detector arrays and tungsten layers. The performance of the mini-tower was tested using pion and electron beams at the CERN Proton Synchrotron (PS). The experimental results are compared with the results from a detailed GEANT-4 simulation. A linear relationship between the observed energy deposition and simulated response of the mini-tower has been obtained, in line with our expectations.

  1. The Time Structure of Hadronic Showers in highly granular Calorimeters with Tungsten and Steel Absorbers

    E-Print Network [OSTI]

    Adloff, C; Chefdeville, M.; Drancourt, C.; Gaglione, R.; Geffroy, N.; Karyotakis, Y.; Koletsou, I.; Prast, J.; Vouters, G.; Repond, J.; Schlereth, J.; Xia, L.; Baldolemar, E.; Li, J.; Park, S.T.; Sosebee, M.; White, A.P.; Yu, J.; Eigen, G.; Thomson, M.A.; Ward, D.R.; Benchekroun, D.; Hoummada, A.; Khoulaki, Y.; Apostolakis, J.; Arfaoui, A.; Benoit, M.; Dannheim, D.; Elsener, K.; Folger, G.; Grefe, C.; Ivantchenko, V.; Killenberg, M.; Klempt, W.; van der Kraaij, E.; Linssen, L.; Lucaci-Timoce, A.-I.; Münnich, A.; Poss, S.; Ribon, A.; Roloff, P.; Sailer, A.; Schlatter, D.; Sicking, E.; Strube, J.; Uzhinskiy, V.; Carloganu, C.; Gay, P.; Manen, S.; Royer, L.; Cornett, U.; David, D.; Ebrahimi, A.; Falley, G.; Feege, N.; Gadow, K.; Göttlicher, P.; Günter, C.; Hartbrich, O.; Hermberg, B.; Karstensen, S.; Krivan, F.; Krüger, K.; Lu, S.; Lutz, B.; Morozov, S.; Morgunov, V.; Neubüser, C.; Reinecke, M.; Sefkow, F.; Smirnov, P.; Terwort, M.; Fagot, A.; Tytgat, M.; Zaganidis, N.; Hostachy, J.-Y.; Morin, L.; Garutti, E.; Laurien, S.; Marchesini, I.; Matysek, M.; Ramilli, M.; Briggl, K.; Eckert, P.; Harion, T.; Schultz-Coulon, H.-Ch.; Shen, W.; Stamen, R.; Chang, S.; Khan, A.; Kim, D.H.; Kong, D.J.; Oh, Y.D.; Bilki, B.; Norbeck, E.; Northacker, D.; Onel, Y.; Wilson, G.W.; Kawagoe, K.; Miyazaki, Y.; Sudo, Y.; Ueno, H.; Yoshioka, T.; Dauncey, P.D.; Cortina Gil, E.; Mannai, S.; Baulieu, G.; Calabria, P.; Caponetto, L.; Combaret, C.; Della Negra, R.; Ete, R.; Grenier, G.; Han, R.; Ianigro, J-C.; Kieffer, R.; Laktineh, I.; Lumb, N.; Mathez, H.; Mirabito, L.; Petrukhin, A.; Steen, A.; Tromeur, W.; Vander Donckt, M.; Zoccarato, Y.; Berenguer Antequera, J.; Calvo Alamillo, E.; Fouz, M.-C.; Puerta-Pelayo, J.; Corriveau, F.; Bobchenko, B.; Chadeeva, M.; Danilov, M.; Epifantsev, A.; Markin, O.; Mizuk, R.; Novikov, E.; Rusinov, V.; Tarkovsky, E.; Kozlov, V.; Soloviev, Y.; Besson, D.; Buzhan, P.; Ilyin, A.; Kantserov, V.; Kaplin, V.; Popova, E.; Tikhomirov, V.; Gabriel, M.; Kiesling, C.; Seidel, K.; Simon, F.; Soldner, C.; Szalay, M.; Tesar, M.; Weuste, L.; Amjad, M.S.; Bonis, J.; Conforti di Lorenzo, S.; Cornebise, P.; Fleury, J.; Frisson, T.; van der Kolk, N.; Richard, F.; Pöschl, R.; Rouene, J.; Anduze, M.; Balagura, V.; Becheva, E.; Boudry, V.; Brient, J-C.; Cornat, R.; Frotin, M.; Gastaldi, F.; Guliyev, E.; Haddad, Y.; Magniette, F.; Ruan, M.; Tran, T.H.; Videau, H.; Callier, S.; Dulucq, F.; Martin-Chassard, G.; de la Taille, Ch.; Raux, L.; Seguin-Moreau, N.; Zacek, J.; Cvach, J.; Gallus, P.; Havranek, M.; Janata, M.; Kvasnicka, J.; Lednicky, D.; Marcisovsky, M.; Polak, I.; Popule, J.; Tomasek, L.; Tomasek, M.; Ruzicka, P.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; Belhorma, B.; Ghazlane, H.; Kotera, K.; Ono, H.; Takeshita, T.; Uozumi, S.; Chai, J.S.; Song, H.S.; Lee, S.H.; Götze, M.; Sauer, J.; Weber, S.; Zeitnitz, C.

    2014-01-01T23:59:59.000Z

    The intrinsic time structure of hadronic showers influences the timing capability and the required integration time of hadronic calorimeters in particle physics experiments, and depends on the active medium and on the absorber of the calorimeter. With the CALICE T3B experiment, a setup of 15 small plastic scintillator tiles read out with Silicon Photomultipliers, the time structure of showers is measured on a statistical basis with high spatial and temporal resolution in sampling calorimeters with tungsten and steel absorbers. The results are compared to GEANT4 (version 9.4 patch 03) simulations with different hadronic physics models. These comparisons demonstrate the importance of using high precision treatment of low-energy neutrons for tungsten absorbers, while an overall good agreement between data and simulations for all considered models is observed for steel.

  2. Test and characterization of a prototype silicon-tungsten electromagnetic calorimeter

    E-Print Network [OSTI]

    Muhuri, Sanjib; Chandratre, Vinay B; Sukhwani, Menka; Jena, Satyajit; Khan, Shuaib Ahmad; Nayak, Tapan K; Saini, Jogender; Singaraju, Rama Narayana

    2014-01-01T23:59:59.000Z

    New generation high-energy physics experiments demand high precision tracking and accurate measurements of a large number of particles produced in the collisions of lementary particles and heavy-ions. Silicon-tungsten (Si-W) calorimeters provide the most viable technological option to meet the requirements of particle detection in high multiplicity environments. We report a novel Si-W calorimeter design, which is optimized for $\\gamma/\\pi^0$ discrimination up to high momenta. In order to test the feasibility of the calorimeter, a prototype mini-tower was constructed using silicon pad detector arrays and tungsten layers. The performance of the mini-tower was tested using pion and electron beams at the CERN Proton Synchrotron (PS). The experimental results are compared with the results from a detailed GEANT-4 simulation. A linear relationship between the observed energy deposition and simulated response of the mini-tower has been obtained, in line with our expectations.

  3. Operational Experience and First Results with a Highly Granular Tungsten Analog Hadron Calorimeter

    E-Print Network [OSTI]

    Frank Simon; for the CALICE Collaboration

    2011-11-22T23:59:59.000Z

    Precision physics at future multi-TeV lepton colliders such as CLIC requires excellent jet energy resolution. The detectors need deep calorimeter systems to limit the energy leakage also for very highly energetic particles and jets. At the same time, compact physical dimensions are mandatory to permit the installation of the complete calorimeter system inside high-field solenoidal magnets. This requires very dense absorbers, making tungsten a natural choice for hadron calorimeters at such a future collider. To study the performance of such a calorimeter, a physics prototype with tungsten absorbers and scintillator tiles with SiPM readout as active elements has been constructed and has been tested in particle beams at CERN over a wide energy range from 1 GeV to 300 GeV. We report on the construction and on the operational experience obtained with muon, electron and hadron beams.

  4. Tungsten injector for scrape-off layer impurity transport experiments in the Tore Supra tokamak

    SciTech Connect (OSTI)

    Ko?an, M.; Lunt, T. [Max-Planck-Institut für Plasmaphysik, EURATOM Association Boltzmannstr. 2, D-85748 Garching (Germany)] [Max-Planck-Institut für Plasmaphysik, EURATOM Association Boltzmannstr. 2, D-85748 Garching (Germany); Gunn, J. P.; Meyer, O.; Pascal, J.-Y. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France)] [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France)

    2013-07-15T23:59:59.000Z

    This paper describes the design and operation of a new tungsten (W) injection system for impurity transport experiments in the Tore Supra tokamak. The system is mounted on a reciprocating manipulator and injects a controlled amount of gaseous tungsten hexacarbonyl, W(CO){sub 6} at arbitrary depth in the scrape-off layer, using an inertially activated valve. Injected W(CO){sub 6} is dissociated in the plasma, forming a radially localized plume of W atoms. The injector does not require an external gas feed and can perform a large number of injections from an on-board reservoir of W(CO){sub 6}. Some examples of W injections in Tore Supra are included, demonstrating successful operation and discussing some technical issues of the injector prototype.

  5. The Time Structure of Hadronic Showers in highly granular Calorimeters with Tungsten and Steel Absorbers

    E-Print Network [OSTI]

    C. Adloff; J. -J. Blaising; M. Chefdeville; C. Drancourt; R. Gaglione; N. Geffroy; Y. Karyotakis; I. Koletsou; J. Prast; G. Vouters J. Repond; J. Schlereth; L. Xia E. Baldolemar; J. Li; S. T. Park; M. Sosebee; A. P. White; J. Yu; G. Eigen; M. A. Thomson; D. R. Ward; D. Benchekroun; A. Hoummada; Y. Khoulaki J. Apostolakis; S. Arfaoui; M. Benoit; D. Dannheim; K. Elsener; G. Folger; C. Grefe; V. Ivantchenko; M. Killenberg; W. Klempt; E. van der Kraaij; L. Linssen; A. -I. Lucaci-Timoce; A. Münnich; S. Poss; A. Ribon; P. Roloff; A. Sailer; D. Schlatter; E. Sicking; J. Strube; V. Uzhinskiy; C. Carloganu; P. Gay; S. Manen; L. Royer; U. Cornett; D. David; A. Ebrahimi; G. Falley; N. Feege; K. Gadow; P. Göttlicher; C. Günter; O. Hartbrich; B. Hermberg; S. Karstensen; F. Krivan; K. Krüger; S. Lu; B. Lutz; S. Morozov; V. Morgunov; C. Neubüser; M. Reinecke; F. Sefkow; P. Smirnov; M. Terwort; A. Fagot; M. Tytgat; N. Zaganidis; J. -Y. Hostachy; L. Morin; E. Garutti; S. Laurien; I. Marchesini; M. Matysek; M. Ramilli; K. Briggl; P. Eckert; T. Harion; H. -Ch. Schultz-Coulon; W. Shen; R. Stamen; S. Chang; A. Khan; D. H. Kim; D. J. Kong; Y. D. Oh; B. Bilki; E. Norbeck; D. Northacker; Y. Onel; G. W. Wilson; K. Kawagoe; Y. Miyazaki; Y. Sudo; H. Ueno; T. Yoshioka; P. D. Dauncey; E. Cortina Gil; S. Mannai; G. Baulieu; P. Calabria; L. Caponetto; C. Combaret; R. Della Negra; R. Ete; G. Grenier; R. Han; J-C. Ianigro; R. Kieffer; I. Laktineh; N. Lumb; H. Mathez; L. Mirabito; A. Petrukhin; A. Steen; W. Tromeur; M. Vander Donckt; Y. Zoccarato J. Berenguer Antequera; E. Calvo Alamillo; M. -C. Fouz; J. Puerta-Pelayo; F. Corriveau; B. Bobchenko; M. Chadeeva; M. Danilov; A. Epifantsev; O. Markin; R. Mizuk; E. Novikov; V. Rusinov; E. Tarkovsky; V. Kozlov; Y. Soloviev; D. Besson; P. Buzhan; A. Ilyin; V. Kantserov; V. Kaplin; E. Popova; V. Tikhomirov; M. Gabriel; C. Kiesling; K. Seidel; F. Simon; C. Soldner; M. Szalay; M. Tesar; L. Weuste; M. S. Amjad; J. Bonis; S. Conforti di Lorenzo; P. Cornebise; J. Fleury; T. Frisson; N. van der Kolk; F. Richard; R. Pöschl; J. Rouene; M. Anduze; V. Balagura; E. Becheva; V. Boudry; J-C. Brient; R. Cornat; M. Frotin; F. Gastaldi; E. Guliyev; Y. Haddad; F. Magniette; M. Ruan; T. H. Tran; H. Videau; S. Callier; F. Dulucq; G. Martin-Chassard; Ch. de la Taille; L. Raux; N. Seguin-Moreau; J. Zacek; J. Cvach; P. Gallus; M. Havranek; M. Janata; J. Kvasnicka; D. Lednicky; M. Marcisovsky; I. Polak; J. Popule; L. Tomasek; M. Tomasek; P. Ruzicka; P. Sicho; J. Smolik; V. Vrba; J. Zalesak; . Belhorma; H. Ghazlane; K. Kotera; H. Ono; T. Takeshita; S. Uozumi; J. S. Chai; H. S. Song; S. H. Lee; M. Götze; J. Sauer; S. Weber; C. Zeitnitz

    2014-07-21T23:59:59.000Z

    The intrinsic time structure of hadronic showers influences the timing capability and the required integration time of hadronic calorimeters in particle physics experiments, and depends on the active medium and on the absorber of the calorimeter. With the CALICE T3B experiment, a setup of 15 small plastic scintillator tiles read out with Silicon Photomultipliers, the time structure of showers is measured on a statistical basis with high spatial and temporal resolution in sampling calorimeters with tungsten and steel absorbers. The results are compared to GEANT4 (version 9.4 patch 03) simulations with different hadronic physics models. These comparisons demonstrate the importance of using high precision treatment of low-energy neutrons for tungsten absorbers, while an overall good agreement between data and simulations for all considered models is observed for steel.

  6. High Strain and Strain-Rate Behaviour of PTFE/Aluminium/Tungsten Mixtures

    E-Print Network [OSTI]

    John Addiss; Jing Cai; Stephen Walley; William Proud; Vitali F. Nesterenko

    2007-11-08T23:59:59.000Z

    Conventional drop-weight techniques were modified to accommodate low-amplitude force transducer signals from low-strength, cold isostatically pressed 'heavy' composites of polytetrafluoroethylene, aluminum and tungsten. The failure strength, strain and the post-critical behavior of failed samples were measured for samples of different porosity and tungsten grain size. Unusual phenomenon of significantly higher strength (55 MPa) of porous composites (density 5.9 g/cc) with small W particles (less than 1 micron) in comparison with strength (32 MPa) of dense composites (7.1 g/cc) with larger W particles (44 microns) at the same volume content of components was observed. This is attributed to force chains created by a network of small W particles. Interrupted tests at different levels of strain revealed the mechanisms of fracture under dynamic compression.

  7. Mechanical characterization and modelling of the heavy tungsten allow IT180

    E-Print Network [OSTI]

    Scapin, M

    2015-01-01T23:59:59.000Z

    Pure tungsten or its alloys(WHA) find applications in several fields, especially due to the fact that these materials show a good combination of mechanical and thermal properties and they are commonly used in aerospace, automotive, metal working processes, military and nuclear technologies. Looking at the scientific literature, a lack in the mechanical characterization over wide ranges in temperature and strain-rates was found, especially forW–Ni–Cu alloys.

  8. Control of Gas Tungsten Arc welding pool shape by trace element addition to the weld pool

    DOE Patents [OSTI]

    Heiple, C.R.; Burgardt, P.

    1984-03-13T23:59:59.000Z

    An improved process for Gas Tungsten Arc welding maximizes the depth/width ratio of the weld pool by adding a sufficient amount of a surface active element to insure inward fluid flow, resulting in deep, narrow welds. The process is especially useful to eliminate variable weld penetration and shape in GTA welding of steels and stainless steels, particularly by using a sulfur-doped weld wire in a cold wire feed technique.

  9. Pulmonary toxicity after exposure to military-relevant heavy metal tungsten alloy particles

    SciTech Connect (OSTI)

    Roedel, Erik Q., E-mail: Erik.Roedel@amedd.army.mil [Department of General Surgery, Tripler Army Medical Center, Honolulu, HI 96859 (United States); Cafasso, Danielle E., E-mail: Danielle.Cafasso@amedd.army.mil [Department of General Surgery, Tripler Army Medical Center, Honolulu, HI 96859 (United States); Lee, Karen W.M., E-mail: Karen.W.Lee@amedd.army.mil [Department of Clinical Investigation, Tripler Army Medical Center, Honolulu, HI 96859 (United States); Pierce, Lisa M., E-mail: Lisa.Pierce@amedd.army.mil [Department of Clinical Investigation, Tripler Army Medical Center, Honolulu, HI 96859 (United States)

    2012-02-15T23:59:59.000Z

    Significant controversy over the environmental and public health impact of depleted uranium use in the Gulf War and the war in the Balkans has prompted the investigation and use of other materials including heavy metal tungsten alloys (HMTAs) as nontoxic alternatives. Interest in the health effects of HMTAs has peaked since the recent discovery that rats intramuscularly implanted with pellets containing 91.1% tungsten/6% nickel/2.9% cobalt rapidly developed aggressive metastatic tumors at the implantation site. Very little is known, however, regarding the cellular and molecular mechanisms associated with the effects of inhalation exposure to HMTAs despite the recognized risk of this route of exposure to military personnel. In the current study military-relevant metal powder mixtures consisting of 92% tungsten/5% nickel/3% cobalt (WNiCo) and 92% tungsten/5% nickel/3% iron (WNiFe), pure metals, or vehicle (saline) were instilled intratracheally in rats. Pulmonary toxicity was assessed by cytologic analysis, lactate dehydrogenase activity, albumin content, and inflammatory cytokine levels in bronchoalveolar lavage fluid 24 h after instillation. The expression of 84 stress and toxicity-related genes was profiled in lung tissue and bronchoalveolar lavage cells using real-time quantitative PCR arrays, and in vitro assays were performed to measure the oxidative burst response and phagocytosis by lung macrophages. Results from this study determined that exposure to WNiCo and WNiFe induces pulmonary inflammation and altered expression of genes associated with oxidative and metabolic stress and toxicity. Inhalation exposure to both HMTAs likely causes lung injury by inducing macrophage activation, neutrophilia, and the generation of toxic oxygen radicals. -- Highlights: ? Intratracheal instillation of W–Ni–Co and W–Ni–Fe induces lung inflammation in rats. ? W–Ni–Co and W–Ni–Fe alter expression of oxidative stress and toxicity genes. ? W–Ni–Co induces a greater oxidative burst response than W–Ni–Fe in lung macrophages.

  10. Method for determining the hardness of strain hardening articles of tungsten-nickel-iron alloy

    DOE Patents [OSTI]

    Wallace, Steven A. (Knoxville, TN)

    1984-01-01T23:59:59.000Z

    The present invention is directed to a rapid nondestructive method for determining the extent of strain hardening in an article of tungsten-nickel-iron alloy. The method comprises saturating the article with a magnetic field from a permanent magnet, measuring the magnetic flux emanating from the article, comparing the measurements of the magnetic flux emanating from the article with measured magnetic fluxes from similarly shaped standards of the alloy with known amounts of strain hardening to determine the hardness.

  11. ACHIEVING THE REQUIRED COOLANT FLOW DISTRIBUTION FOR THE ACCELERATOR PRODUCTION OF TRITIUM (APT) TUNGSTEN NEUTRON SOURCE

    SciTech Connect (OSTI)

    D. SIEBE; K. PASAMEHMETOGLU

    2000-11-01T23:59:59.000Z

    The Accelerator Production of Tritium neutron source consists of clad tungsten targets, which are concentric cylinders with a center rod. These targets are arranged in a matrix of tubes, producing a large number of parallel coolant paths. The coolant flow required to meet thermal-hydraulic design criteria varies with location. This paper describes the work performed to ensure an adequate coolant flow for each target for normal operation and residual heat-removal conditions.

  12. Enhanced photoelectrochemical properties of TiO{sub 2} by codoping with tungsten and silver

    SciTech Connect (OSTI)

    Khan, Matiullah, E-mail: matiullahustb@gmail.com [Department of Inorganic Nonmetallic Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Department of Physics, Kohat University of Science and Technology (KUST), Kohat 26000 (Pakistan); Jiang, Peng; Cao, Wenbin, E-mail: wbcao@ustb.edu.cn [Department of Inorganic Nonmetallic Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Li, Jing [State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083 (China)

    2014-04-21T23:59:59.000Z

    The Tungsten (W) and Silver (Ag) codoped TiO{sub 2} samples were successfully synthesized by hydrothermal method without any post calcination. To understand the correlation between electronic structure and photocatalytic properties, the synthesized samples were characterized using X-ray diffraction, Brunauer–Emmett–Teller specific surface area, transmission electron microscopy, ultra-violet–visible absorption spectra, and X-ray photoelectron spectroscopy (XPS), and the photocatalytic properties were evaluated under visible light irradiations. Codoping could not induce any changes in the phase and all the synthesized samples displayed pure anatase phase with spherical morphology. Visible light absorptions of the codoped samples were dramatically improved compared to the corresponding mono-doped samples. XPS analysis indicated that the dopant atoms successfully entered the TiO{sub 2} network. Results from the visible light photodegradation experiments showed that tungsten-silver codoped TiO{sub 2} possessed strong ability in photo-degrading methylene blue compared to tungsten doped TiO{sub 2} and silver doped TiO{sub 2}, which was attributed to the smaller particle size, higher specific surface area, enhanced visible light absorption, and improved separation of photogenerated carriers.

  13. Growth of tungsten nanoparticles in direct-current argon glow discharges

    SciTech Connect (OSTI)

    Kishor Kumar, K.; Coueedel, L.; Arnas, C. [Laboratoire de Physique des Interactions Ioniques et Moleculaires, CNRS-Aix-Marseille Universite, 13397 Marseille (France)

    2013-04-15T23:59:59.000Z

    The growth of nanoparticles from the sputtering of a tungsten cathode in DC argon glow discharges is reported. The study was performed at fixed argon pressure and constant discharge current. The growth by successive agglomerations is evidenced. First, tungsten nanocrystallites agglomerate into primary particles, the most probable size of which being {approx}30 nm. Primary particles of this size are observed for all plasma durations and always remain the most numerous in the discharge. Primary particles quickly agglomerate to form particles with size up to {approx}150 nm. For short plasma duration, log-normal functions describe accurately the dust particle size distributions. On the contrary, for long discharge durations, a second hump appears in the distributions toward large particle sizes. In the meantime, the discharge voltage, electron density, and emission line intensities strongly evolve. Their evolutions can be divided in four separate phases and exhibit unusual distinctive features compared to earlier observations in discharges in which particles were growing. The evolution of the different parameters is explained by a competition between the surface state of the tungsten cathode and the influence of the growing nanoparticles. The differences with sputtering glow discharges and chemically active plasmas suggest that the nanoparticle growth and its influence on discharge parameters is system and material dependent.

  14. Effect of tungsten crystallographic orientation on He-ion-induced surface morphology changes

    SciTech Connect (OSTI)

    Parish, Chad M [ORNL; Hijazi, Hussein Dib [ORNL; Meyer III, Harry M [ORNL; Meyer, Fred W [ORNL

    2014-01-01T23:59:59.000Z

    In order to study the early stages of nanofuzz growth in fusion-plasma-facing tungsten, mirror-polished high-purity tungsten was exposed to 80 eV helium at 1130 C to a fluence of 4 1024 He/m2. The previously smooth surface shows morphology changes, and grains form one of four qualitatively different morphologies: smooth, wavy, pyramidal, or terraced/wide waves. Combining high-resolution scanning electron microscopy (SEM) observations to determine the morphology of each grain with quantitative measurement of the grain's orientation via electron backscatter diffraction (EBSD) in SEM shows that the normal-direction crystallographic orientation of the underlying grain controls the growth morphology. Specifically, near-<001> || normal direction (ND) grains formed pyramids, near-<114> to <112> || ND grains formed wavy and stepped structures, and near-<103> || ND grains remained smooth. Comparisons to control specimens indicate no changes to underlying bulk crystallographic texture, and the effects are attributed to surface energy anisotropy, although, surprisingly, the expected {101} low-energy planes were not the most stable. Future developments to control tungsten texture via thermomechanical processing, ideally obtaining a sharp near- <103> || ND processing texture, may delay the formation of nanofuzz.

  15. Measurements of the Time Structure of Hadronic Showers in a Scintillator-Tungsten HCAL

    E-Print Network [OSTI]

    Frank Simon; for the CALICE Collaboration

    2011-09-15T23:59:59.000Z

    For calorimeter applications requiring precise time stamping, the time structure of hadronic showers in the detector is a crucial issue. This applies in particular to detector concepts for CLIC, where a hadronic calorimeter with tungsten absorbers is being considered to achieve a high level of shower containment while satisfying strict space constraints. The high hadronic background from gamma gamma to hadrons processes at 3 TeV in combination with the 2 GHz bunch crossing frequency at CLIC requires good time stamping in the detectors. To provide first measurements of the time structure in a highly granular scintillator-tungsten calorimeter, T3B, a dedicated timing experiment, was installed behind the last layer of the CALICE WHCAL prototype, a 30 layer tungsten scintillator calorimeter. T3B consists of 15 small scintillator cells with embedded silicon photomultipliers, read out with fast digitizers over a time window of 2.4 us, and provides detailed measurements of the time structure of the signal. The offline data reconstruction performs an automatic gain calibration using noise events recorded between physics triggers and allows the determination of the arrival time of each photon at the photon sensor. The T3B setup, its calibration and data reconstruction, as well as first results of the time structure of the calorimeter response for 10 GeV pions recorded at the CERN PS confronted with Geant4 simulations using different physics lists are discussed.

  16. Study of electrodeposited nickel-molybdenum, nickel-tungsten, cobalt-molybdenum, and cobalt-tungsten as hydrogen electrodes in alkaline water electrolysis

    SciTech Connect (OSTI)

    Fan, C.; Piron, D.L.; Sleb, A.; Paradis, P. (Ecole Polytechnique de Montreal, Quebec (Canada). Dept. de Metallurgie et de Genie des Materiaux)

    1994-02-01T23:59:59.000Z

    Electrodeposited nickel-molybdenum, nickel-tungsten, cobalt-molybdenum, and cobalt-tungsten were characterized for the hydrogen evolution reaction (HER) in the electrolysis of 30 w/o KOH alkaline water at 25 C. The rate-determining step (rds) of the HER was suggested based on the Tafel slope of polarization and the capacitance of electrode-solution interface determined by ac impedance measurement. The HER on the nickel- and cobalt-based codeposits was enhanced significantly compared with that o the electrolytic nickel and cobalt with comparable deposit loadings. The decrease in the HER overpotential was more pronounced on the molybdenum-containing codeposits, particularly on cobalt-molybdenum which also showed a high stability. The enhancement of the HER was attributed to both the synergetic composition and the increased active surface of the codeposits. The real electrocatalytic activity of te electrodes and the effect of their and the increased active surface of the codeposits. The real electrocatalytic activity of the electrodes and the effect of their surface increase were distinguished quantitatively. The linear relations between HER overpotential and surface roughness factor of the electrodes on a Y-log(X) plot were obtained experimentally and interpreted based on the Tafel law.

  17. A study of tungsten spectra using large helical device and compact electron beam ion trap in NIFS

    SciTech Connect (OSTI)

    Morita, S.; Goto, M.; Murakami, I. [National Institute for Fusion Science, Toki 509-5292, Gifu (Japan); Department of Fusion Science, Graduate University for Advanced Studies, Toki 509-5292, Gifu (Japan); Dong, C. F.; Kato, D.; Sakaue, H. A.; Oishi, T. [National Institute for Fusion Science, Toki 509-5292, Gifu (Japan); Hasuo, M. [Department of Mechanical Engineering and Science, Graduate School of Engineering, Kyoto University, Kyoto 606-8501 (Japan); Koike, F. [Physics Laboratory, School of Medicine, Kitasato University, Sagamihara 252-0374 (Japan); Nakamura, N. [Institute of Laser Science, University of Electro-Communications, Tokyo 182-8585 (Japan); Sasaki, A. [Quantum Beam Science Directorate, Japan Atomic Energy Research Agency, Kizugawa 619-0215, Kyoto (Japan); Wang, E. H. [Department of Fusion Science, Graduate University for Advanced Studies, Toki 509-5292, Gifu (Japan)

    2013-07-11T23:59:59.000Z

    Tungsten spectra have been observed from Large Helical Device (LHD) and Compact electron Beam Ion Trap (CoBIT) in wavelength ranges of visible to EUV. The EUV spectra with unresolved transition array (UTA), e.g., 6g-4f, 5g-4f, 5f-4d and 5p-4d transitions for W{sup +24-+33}, measured from LHD plasmas are compared with those measured from CoBIT with monoenergetic electron beam ({<=}2keV). The tungsten spectra from LHD are well analyzed based on the knowledge from CoBIT tungsten spectra. The C-R model code has been developed to explain the UTA spectra in details. Radial profiles of EUV spectra from highly ionized tungsten ions have been measured and analyzed by impurity transport simulation code with ADPAK atomic database code to examine the ionization balance determined by ionization and recombination rate coefficients. As the first trial, analysis of the tungsten density in LHD plasmas is attempted from radial profile of Zn-like WXLV (W{sup 44+}) 4p-4s transition at 60.9A based on the emission rate coefficient calculated with HULLAC code. As a result, a total tungsten ion density of 3.5 Multiplication-Sign 10{sup 10}cm{sup -3} at the plasma center is reasonably obtained. In order to observe the spectra from tungsten ions in lower-ionized charge stages, which can give useful information on the tungsten influx in fusion plasmas, the ablation cloud of the impurity pellet is directly measured with visible spectroscopy. A lot of spectra from neutral and singly ionized tungsten are observed and some of them are identified. A magnetic forbidden line from highly ionized tungsten ions has been examined and Cd-like WXXVII (W{sup 26+}) at 3893.7A is identified as the ground-term fine-structure transition of 4f{sup 23}H{sub 5}-{sup 3}H{sub 4}. The possibility of {alpha} particle diagnostic in D-T burning plasmas using the magnetic forbidden line is discussed.

  18. Discovery, SAR, and Radiolabeling of Halogenated Benzimidazole Carboxamide Antagonists as Useful Tools for (alpha)4(beta)1 Integrin Expressed on T- and B-cell Lymphomas

    SciTech Connect (OSTI)

    Carpenter, R D; Natarajan, A; Lau, E Y; Andrei, M; Solano, D M; Lightstone, F C; DeNardo, S J; Lam, K S; Kurth, M J

    2010-02-08T23:59:59.000Z

    The cell surface receptor {alpha}{sub 4}{beta}{sub 1} integrin is an attractive yet poorly understood target for selective diagnosis and treatment of T- and B-cell lymphomas. This report focuses on the rapid microwave preparation of medicinally pertinent benzimidazole heterocycles, structure-activity relationships (SAR) of novel halobenzimidazole carboxamide antagonists 3-6, and preliminary biological evaluation of radioiodinated agents 7, 8, and 18. The I-125 derivative 18 had good tumor uptake (12 {+-} 1% ID/g at 24 h; 4.5 {+-} 1% ID/g at 48 h) and tumor:kidney ratio ({approx}4:1 at 24 h; 2.5:1 at 48 h) in xenograft murine models of B-cell lymphoma. Molecular homology models of {alpha}{sub 4}{beta}{sub 1} integrin have predicted that docked halobenzimidazole carboxamides have the halogen atom in a suitable orientation for halogen-hydrogen bonding. These high affinity ({approx} pM binding) halogenated ligands are attractive tools for medicinal and biological use; the fluoro and iodo derivatives are potential radiodiagnostic ({sup 18}F) or radiotherapeutic ({sup 131}I) agents, whereas the chloro and bromo analogues could provide structural insight into integrin-ligand interactions through photoaffinity cross-linking/mass spectroscopy experiments, as well as co-crystallization X-ray studies.

  19. DIVIMP Tungsten Erosion and Transport Simulations of an ELM Cycle in a JET Type-I ELMy H-mode Plasma

    E-Print Network [OSTI]

    DIVIMP Tungsten Erosion and Transport Simulations of an ELM Cycle in a JET Type-I ELMy H-mode Plasma

  20. Influence of Atomic Physics on EDGE2D-EIRENE Simulations of JET Divertor Detachment with Carbon and Beryllium/Tungsten Plasma-Facing Components

    E-Print Network [OSTI]

    Influence of Atomic Physics on EDGE2D-EIRENE Simulations of JET Divertor Detachment with Carbon and Beryllium/Tungsten Plasma-Facing Components

  1. Impact of the Carbon and Tungsten Wall Materials on Deuterium Recycling and Neutral Fuelling in JET using EDGE2D/EIRENE

    E-Print Network [OSTI]

    Impact of the Carbon and Tungsten Wall Materials on Deuterium Recycling and Neutral Fuelling in JET using EDGE2D/EIRENE

  2. Target Particle and Heat Loads in Low-Triangularity L-mode Plasmas in JET with Carbon and Beryllium/Tungsten Walls

    E-Print Network [OSTI]

    Target Particle and Heat Loads in Low-Triangularity L-mode Plasmas in JET with Carbon and Beryllium/Tungsten Walls

  3. EFFECTS OF B, C, N, O, P AND S IMPURITIES ON TUNGSTEN ?27[110]{552} AND ?3[110]{112} GRAIN BOUNDARIES

    SciTech Connect (OSTI)

    Setyawan, Wahyu; Kurtz, Richard J.

    2013-04-01T23:59:59.000Z

    The objective of this research is to support the design of tungsten-based materials with increased fracture resistance using first-principles computational methods.

  4. Simulation of Tungsten Sputtering with EDGE2D-EIRENE in Low Triangularity L-Mode JET ITER-Like Wall Configuration

    E-Print Network [OSTI]

    Simulation of Tungsten Sputtering with EDGE2D-EIRENE in Low Triangularity L-Mode JET ITER-Like Wall Configuration

  5. A Bulk Tungsten Tile for JET: Derivation of Power-Handling Performance and Validation of the Thermal Model, in the MARION Facility

    E-Print Network [OSTI]

    A Bulk Tungsten Tile for JET: Derivation of Power-Handling Performance and Validation of the Thermal Model, in the MARION Facility

  6. Influence of tungsten substitution and oxygen deficiency on the thermoelectric properties of CaMnO{sub 3??}

    SciTech Connect (OSTI)

    Thiel, Philipp; Eilertsen, James; Populoh, Sascha, E-mail: sascha.populoh@empa.ch; Saucke, Gesine; Shkabko, Andrey; Sagarna, Leyre; Karvonen, Lassi [Laboratory for Solid State Chemistry and Catalysis, Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Döbeli, Max [Ion Beam Physics, Schafmattstrasse 20, ETH Hönggerberg, Swiss Federal Institute of Technology, CH-8093 Zürich (Switzerland); Weidenkaff, Anke [Laboratory for Solid State Chemistry and Catalysis, Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Materials Chemistry, Institute for Materials Science, University of Stuttgart, Heisenbergstr. 3, DE-70569 Stuttgart (Germany)

    2013-12-28T23:59:59.000Z

    Polycrystalline tungsten-substituted CaMn{sub 1?x}W{sub x}O{sub 3??} (0.00???x???0.05) powders were synthesized from a polymeric precursor, pressed and sintered to high density. The impact of tungsten substitution on the crystal structure, thermal stability, phase transition, electronic and thermal transport properties is assessed. Tungsten acts as an electron donator and strongly affects high-temperature oxygen stoichiometry. Oxygen vacancies form in the high figure-of-merit (ZT)-region starting from about T?=?1000?K and dominate the carrier concentration and electronic transport far more than the tungsten substitution. The analysis of the transport properties yields that in the investigated regime the band filling is sufficiently high to overcome barriers of polaron transport. Therefore, the Cutler-Mott approach describes the electrical transport more accurately than the Mott approach for small polaron transport. The lattice thermal conductivity near room temperature is strongly suppressed with increasing tungsten concentration due to mass-difference impurity scattering. A ZT of 0.25 was found for x?=?0.04 at 1225?K.

  7. The Effect of 800 MeV Proton Irradiation on the Mechanical Properties of Tungsten at Room Temperature and at 475 Degrees C

    SciTech Connect (OSTI)

    Maloy, S A.; James, M R.; Sommer, Walter F.; Willcutt, Gordon; Lopez, M; Romero, T J.; Toloczko, Mychailo B.

    2005-08-01T23:59:59.000Z

    For the accelerator production of tritium (APT), the accelerator driven transmutation facility (ADTF), and the advanced fuel cycle initiative (AFCI), tungsten is being proposed as a target material to produce neutrons. In this study, tungsten rods were irradiated at the 800MeV Los Alamos Neutron Science Center (LANSCE) proton accelerator for six months.

  8. Dielectric and photovoltaic phenomena in tungsten-doped Pb,,Mg1/3Nb2/3...1-xTixO3 crystal

    E-Print Network [OSTI]

    Dielectric and photovoltaic phenomena in tungsten-doped Pb,,Mg1/3Nb2/3...1-xTixO3 crystal Chi. The tungsten-doped Pb1-xLax ZryTiz 1-x/4O3 ceramics, i.e., PLZT x/y/z , exhibits a large photovoltaic ef- fect

  9. A Solid-State NMR Study of Tungsten Methyl Group Dynamics in [W(5-C5Me5)Me4][PF6

    E-Print Network [OSTI]

    Griffin, Robert G.

    A Solid-State NMR Study of Tungsten Methyl Group Dynamics in [W(5-C5Me5)Me4][PF6] Douglas C. Maus Spinning (MAS) 13C and static 2H NMR studies of the dynamics of the methyl groups coordinated to tungsten

  10. Radiation-Damage Study of a Monocrystalline Tungsten Positron Converter X. Artru, R. Kirsch, IPN, Lyon, France; R. Chehab, LAL, Orsay, France;

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Radiation-Damage Study of a Monocrystalline Tungsten Positron Converter X. Artru, R. Kirsch, IPN tested on a 0.3 mm thick tungsten monocrystal exposed dur- ing 6 months to the 30 Gev incident electron and the corresponding enhancement in pair production [1, 3]. Their use in linear colliders (LC), where high beam

  11. Phases and domain structures in tungsten-doped Pb,,Mg1/3Nb2/3...1-xTixO3 ,,x=0.35... crystal

    E-Print Network [OSTI]

    Phases and domain structures in tungsten-doped Pb,,Mg1/3Nb2/3...1-xTixO3 ,,x=0.35... crystal F and piezoelectric response, has the great potential of applications in wireless photoactuators. The tungsten ferroelectric physics of tungsten-doped PMNT single crystals is still unclear. In this study, temperature

  12. ANALYSIS OF A CLAD TUNGSTEN TARGET AFTER IRRADIATION IN AN 800 MeV PROTON BEAM S.A. Maloy, M.R. James, W.F. Sommer jr.,

    E-Print Network [OSTI]

    McDonald, Kirk

    Production of Tritium (APT) and the Accelerator Driven Transmutation Facility (ADTF), tungsten is beingANALYSIS OF A CLAD TUNGSTEN TARGET AFTER IRRADIATION IN AN 800 MeV PROTON BEAM S.A. Maloy, M of tungsten are degraded from irradiation in a neutron flux but little work had been performed

  13. Parametric Studies Of Weld Quality Of Tungsten Inert Gas Arc Welding Of Stainless Steel

    SciTech Connect (OSTI)

    Kumar Pal, Pradip; Nandi, Goutam; Ghosh, Nabendu [Mechanical Engineering Department, Jadavpur University, Kolkata-700032 (India)

    2011-01-17T23:59:59.000Z

    Effect of current and gas flow rate on quality of weld in tungsten inter gas arc welding of austenitic stainless steel has been studied in the present work through experiments and analyses. Butt welded joints have been made by using several levels of current and gas flow rate. The quality of the weld has been evaluated in terms of ultimate and breaking strengths of the welded specimens. The observed data have been interpreted, discussed and analyzed by using Grey--Taguchi methodology. Optimum parametric setting has been predicted and validated as well.

  14. Shock-less interactions of ablation streams in tungsten wire array z-pinches

    SciTech Connect (OSTI)

    Swadling, G. F.; Lebedev, S. V.; Hall, G. N.; Suzuki-Vidal, F.; Burdiak, G.; Harvey-Thompson, A. J.; Bland, S. N.; De Grouchy, P.; Khoory, E.; Pickworth, L.; Skidmore, J.; Suttle, L. [The Blackett Laboratory, Imperial College, London SW7 2AZ (United Kingdom)] [The Blackett Laboratory, Imperial College, London SW7 2AZ (United Kingdom)

    2013-06-15T23:59:59.000Z

    Shock-less dynamics were observed during the ablation phase in tungsten wire array experiments carried out on the 1.4 MA, 240 ns MAGPIE generator at Imperial College London. This behaviour contrasts with the shock structures which were seen to dominate in previous experiments on aluminium arrays [Swadling et al., Phys. Plasmas 20, 022705 (2013)]. In this paper, we present experimental results and make comparisons both with calculations of the expected mean free paths for collisions between the ablation streams and with previously published Thomson scattering measurements of the plasma parameters in these arrays [Harvey-Thompson et al., Phys. Plasmas 19, 056303 (2012)].

  15. Testing Hadronic Interaction Models using a Highly Granular Silicon-Tungsten Calorimeter

    E-Print Network [OSTI]

    Bilki, B; Schlereth, J; Xia, L; Deng, Z; Li, Y; Wang, Y; Yue, Q; Yang, Z; Eigen, G; Mikami, Y; Price, T; Watson, N K; Thomson, M A; Ward, D R; Benchekroun, D; Hoummada, A; Khoulaki, Y; Cârloganu, C; Chang, S; Khan, A; Kim, D H; Kong, D J; Oh, Y D; Blazey, G C; Dyshkant, A; Francis, K; Lima, J G R; Salcido, P; Zutshi, V; Boisvert, V; Green, B; Misiejuk, A; Salvatore, F; Kawagoe, K; Miyazaki, Y; Sudo, Y; Suehara, T; Tomita, T; Ueno, H; Yoshioka, T; Apostolakis, J; Folger, G; Ivantchenko, V; Ribon, A; Uzhinskiy, V; Cauwenbergh, S; Tytgat, M; Zaganidis, N; Hostachy, J -Y; Morin, L; Gadow, K; Göttlicher, P; Günter, C; Krüger, K; Lutz, B; Reinecke, M; Sefkow, F; Feege, N; Garutti, E; Laurien, S; Lu, S; Marchesini, I; Matysek, M; Ramilli, M; Kaplan, A; Norbeck, E; Northacker, D; Onel, Y; Kim, E J; van Doren, B; Wilson, G W; Wing, M; Bobchenko, B; Chadeeva, M; Chistov, R; Danilov, M; Drutskoy, A; Epifantsev, A; Markin, O; Mizuk, R; Novikov, E; Popov, V; Rusinov, V; Tarkovsky, E; Besson, D; Popova, E; Gabriel, M; Kiesling, C; Simon, F; Soldner, C; Szalay, M; Tesar, M; Weuste, L; Amjad, M S; Bonis, J; Callier, S; di Lorenzo, S Conforti; Cornebise, P; Doublet, Ph; Dulucq, F; Faucci-Giannelli, M; Fleury, J; Frisson, T; Kégl, B; van der Kolk, N; Li, H; Martin-Chassard, G; Richard, F; de la Taille, Ch; Pöschl, R; Raux, L; Rouëné, J; Seguin-Moreau, N; Anduze, M; Balagura, V; Becheva, E; Boudry, V; Brient, J-C; Cornat, R; Frotin, M; Gastaldi, F; Magniette, F; Matthieu, A; de Freitas, P Mora; Videau, H; Augustin, J-E; David, J; Ghislain, P; Lacour, D; Lavergne, L; Zacek, J; Cvach, J; Gallus, P; Havranek, M; Janata, M; Kvasnicka, J; Lednicky, D; Marcisovsky, M; Polak, I; Popule, J; Tomasek, L; Tomasek, M; Ruzicka, P; Sicho, P; Smolik, J; Vrba, V; Zalesak, J; Jeans, D; Götze, M

    2014-01-01T23:59:59.000Z

    A detailed study of hadronic interactions is presented using data recorded with the highly granular CALICE silicon-tungsten electromagnetic calorimeter. Approximately 600,000 selected negatively changed pion events at energies between 2 and 10 GeV have been studied. The predictions of several physics models available within the GEANT4 simulation tool kit are compared to this data. Although a reasonable overall description of the data is observed, there are significant quantitative discrepancies in the longitudinal and transverse distributions of reconstructed energy.

  16. Study of the interactions of pions in the CALICE silicon-tungsten calorimeter prototype

    E-Print Network [OSTI]

    C. Adloff; Y. Karyotakis; J. Repond; J. Yu; G. Eigen; Y. Mikami; N. K. Watson; J. A. Wilson; T. Goto; G. Mavromanolakis; M. A. Thomson; D. R. Ward; W. Yan; D. Benchekroun; A. Hoummada; Y. Khoulaki; J. Apostolakis; A. Ribon; V. Uzhinskiy; M. Benyamna; C. Cârloganu; F. Fehr; P. Gay; G. C. Blazey; D. Chakraborty; A. Dyshkant; K. Francis; D. Hedin; J. G. Lima; V. Zutshi; J. -Y. Hostachy; K. Krastev; L. Morin; N. D'Ascenzo; U. Cornett; D. David; R. Fabbri; G. Falley; K. Gadow; E. Garutti; P. Göttlicher; T. Jung; S. Karstensen; A. -I. Lucaci-Timoce; B. Lutz; N. Meyer; V. Morgunov; M. Reinecke; F. Sefkow; P. Smirnov; A. Vargas-Trevino; N. Wattimena; O. Wendt; N. Feege; M. Groll; J. Haller; R. -D. Heuer; S. Morozov; S. Richter; J. Samson; A. Kaplan; H. -Ch. Schultz-Coulon; W. Shen; A. Tadday; B. Bilki; E. Norbeck; Y. Onel; E. J. Kim; G. Kim; D-W. Kim; K. Lee; S. C. Lee; K. Kawagoe; Y. Tamura; P. D. Dauncey; A. -M. Magnan; H. Yilmaz; O. Zorba; V. Bartsch; M. Postranecky; M. Warren; M. Wing; M. G. Green; F. Salvatore; M. Bedjidian; R. Kieffer; I. Laktineh; M. -C. Fouz; D. S. Bailey; R. J. Barlow; M. Kelly; R. J. Thompson; M. Danilov; E. Tarkovsky; N. Baranova; D. Karmanov; M. Korolev; M. Merkin; A. Voronin; A. Frey; S. Lu; K. Seidel; F. Simon; C. Soldner; L. Weuste; J. Bonis; B. Bouquet; S. Callier; P. Cornebise; Ph. Doublet; M. Faucci Giannelli; J. Fleury; H. Li; G. Martin-Chassard; F. Richard; Ch. de la Taille; R. Poeschl; L. Raux; N. Seguin-Moreau; F. Wicek; M. Anduze; V. Boudry; J-C. Brient; G. Gaycken; D. Jeans; P. Mora de Freitas; G. Musat; M. Reinhard; A. Rougé; M. Ruan; J-Ch. Vanel; H. Videau; K-H. Park; J. Zacek; J. Cvach; P. Gallus; M. Havranek; M. Janata; M. Marcisovsky; I. Polak; J. Popule; L. Tomasek; M. Tomasek; P. Ruzicka; P. Sicho; J. Smolik; V. Vrba; J. Zalesak; B. Belhorma; M. Belmir; S. W. Nam; I. H. Park; J. Yang; Jong-Seo Chai; Jong-Tae Kim; Geun-Bum Kim; J. Kang; Y. -J. Kwon

    2010-04-28T23:59:59.000Z

    A prototype silicon-tungsten electromagnetic calorimeter for an ILC detector was tested in 2007 at the CERN SPS test beam. Data were collected with electron and hadron beams in the energy range 8 to 80 GeV. The analysis described here focuses on the interactions of pions in the calorimeter. One of the main objectives of the CALICE program is to validate the Monte Carlo tools available for the design of a full-sized detector. The interactions of pions in the Si-W calorimeter are therefore confronted with the predictions of various physical models implemented in the GEANT4 simulation framework.

  17. Testing Hadronic Interaction Models using a Highly Granular Silicon-Tungsten Calorimeter

    E-Print Network [OSTI]

    The CALICE Collaboration; B. Bilki; J. Repond; J. Schlereth; L. Xia; Z. Deng; Y. Li; Y. Wang; Q. Yue; Z. Yang; G. Eigen; Y. Mikami; T. Price; N. K. Watson; M. A. Thomson; D. R. Ward; D. Benchekroun; A. Hoummada; Y. Khoulaki; C. Cârloganu; S. Chang; A. Khan; D. H. Kim; D. J. Kong; Y. D. Oh; G. C. Blazey; A. Dyshkant; K. Francis; J. G. R. Lima; P. Salcido; V. Zutshi; V. Boisvert; B. Green; A. Misiejuk; F. Salvatore; K. Kawagoe; Y. Miyazaki; Y. Sudo; T. Suehara; T. Tomita; H. Ueno; T. Yoshioka; J. Apostolakis; G. Folger; G. Folger; V. Ivantchenko; A. Ribon; V. Uzhinskiy; S. Cauwenbergh; M. Tytgat; N. Zaganidis; J. -Y. Hostachy; L. Morin; K. Gadow; P. Göttlicher; C. Günter; K. Krüger; B. Lutz; M. Reinecke; F. Sefkow; N. Feege; E. Garutti; S. Laurien; S. Lu; I. Marchesini; M. Matysek; M. Ramilli; A. Kaplan; E. Norbeck; D. Northacker; Y. Onel; E. J. Kim; B. van Doren; G. W. Wilson; M. Wing; B. Bobchenko; M. Chadeeva; R. Chistov; M. Danilov; A. Drutskoy; A. Epifantsev; O. Markin; R. Mizuk; E. Novikov; V. Popov; V. Rusinov; E. Tarkovsky; D. Besson; E. Popova; M. Gabriel; C. Kiesling; F. Simon; C. Soldner; M. Szalay; M. Tesar; L. Weuste; M. S. Amjad; J. Bonis; S. Callier; S. Conforti di Lorenzo; P. Cornebise; Ph. Doublet; F. Dulucq; M. Faucci-Giannelli; J. Fleury; T. Frisson; B. Kégl; N. van der Kolk; H. Li; G. Martin-Chassard; F. Richard; Ch. de la Taille; R. Pöschl; L. Raux; J. Rouëné; N. Seguin-Moreau; M. Anduze; V. Balagura; E. Becheva; V. Boudry; J-C. Brient; R. Cornat; M. Frotin; F. Gastaldi; F. Magniette; A. Matthieu; P. Mora de Freitas; H. Videau; J-E. Augustin; J. David; P. Ghislain; D. Lacour; L. Lavergne; J. Zacek; J. Cvach; P. Gallus; M. Havranek; M. Janata; J. Kvasnicka; D. Lednicky; M. Marcisovsky; I. Polak; J. Popule; L. Tomasek; M. Tomasek; P. Ruzicka; P. Sicho; J. Smolik; V. Vrba; J. Zalesak; D. Jeans; M. Götze

    2014-11-26T23:59:59.000Z

    A detailed study of hadronic interactions is presented using data recorded with the highly granular CALICE silicon-tungsten electromagnetic calorimeter. Approximately 600,000 selected negatively changed pion events at energies between 2 and 10 GeV have been studied. The predictions of several physics models available within the GEANT4 simulation tool kit are compared to this data. Although a reasonable overall description of the data is observed, there are significant quantitative discrepancies in the longitudinal and transverse distributions of reconstructed energy.

  18. Performance of a Tungsten-Cerium Fluoride Sampling Calorimeter in High-Energy Electron Beam Tests

    E-Print Network [OSTI]

    Becker, R; Dissertori, G; Djambazov, L; Donegà, M; Lustermann, W; Marini, A C; Nessi-Tedaldi, F; Pandolfi, F; Peruzzi, M; Schönenberger, M; Cavallari, F; Dafinei, I; Diemoz, M; Lope, C Jorda; Meridiani, P; Nuccetelli, M; Paramatti, R; Pellegrino, F; Micheli, F; Organtini, G; Rahatlou, S; Soffi, L; Brianza, L; Govoni, P; Martelli, A; de Fatis, T Tabarelli; Monti, V; Pastrone, N; Trapani, P P; Candelise, V; Della Ricca, G

    2015-01-01T23:59:59.000Z

    A prototype for a sampling calorimeter made out of cerium fluoride crystals interleaved with tungsten plates, and read out by wavelength-shifting fibres, has been exposed to beams of electrons with energies between 20 and 150 GeV, produced by the CERN Super Proton Synchrotron accelerator complex. The performance of the prototype is presented and compared to that of a Geant4 simulation of the apparatus. Particular emphasis is given to the response uniformity across the channel front face, and to the prototype's energy resolution.

  19. Remote reactor repair: GTA (gas tungsten Arc) weld cracking caused by entrapped helium

    SciTech Connect (OSTI)

    Kanne, W.R. Jr.

    1988-01-01T23:59:59.000Z

    A repair patch was welded to the wall of a nuclear reactor tank using remotely controlled thirty-foot long robot arms. Further repair was halted when gas tungsten arc (GTA) welds joining type 304L stainless steel patches to the 304 stainless steel wall developed toe cracks in the heat-affected zone (HAZ). The role of helium in cracking was investigated using material with entrapped helium from tritium decay. As a result of this investigation, and of an extensive array of diagnostic tests performed on reactor tank wall material, helium embrittlement was shown to be the cause of the toe cracks.

  20. Progress report on a fully automatic Gas Tungsten Arc Welding (GTAW) system development

    SciTech Connect (OSTI)

    Daumeyer, G.J. III

    1994-12-01T23:59:59.000Z

    A plan to develop a fully automatic gas tungsten arc welding (GTAW) system that will utilize a vision-sensing computer (which will provide in-process feedback control) is presently in work. Evaluations of different technological aspects and system design requirements continue. This report summaries major activities in the plan`s successful progress. The technological feasibility of producing the fully automated GTAW system has been proven. The goal of this process development project is to provide a production-ready system within the shortest reasonable time frame.

  1. Preparation of amorphous electrochromic tungsten oxide and molybdenum oxide by plasma enhanced chemical vapor deposition

    SciTech Connect (OSTI)

    Tracy, C.E.; Benson, D.K.

    1986-09-01T23:59:59.000Z

    Preliminary experiments have been performed to probe the feasibility of using plasma enhanced chemical vapor deposition (PE--CVD) to prepare electrochromic thin films of tungsten oxide and molybdenum oxide by plasma reaction of WF/sub 6/, W(CO)/sub 6/, and Mo(CO)/sub 6/ with oxygen. Thin films produced in a 300 W, electrodeless, radio-frequency (rf), capacitive discharge were found to be electrochromic when tested with either liquid or solid electrolytes. Optical spectroscopy was performed on two electrochromic coatings after Li/sup +/ ion insertion from a propylene carbonate liquid electrolyte. Broad absorption peaks at --900 nm for WO/sub 3/ and 600 nm for MoO/sub 3/ were observed. Optical results for PE--CVD MoO/sub 3/ films differ from those reported for evaporated MoO/sub 3/ films which have an absorption peak at --800 nm. The shorter wavelength absorption in the PE--CVD MoO/sub 3/ films offers the potential for fabricating electrochromic devices with higher contrast ratios and less color change. Optical emission spectroscopy, Auger, and x-ray diffraction analyses indicate these thin film deposits to be predominantly amorphous tungsten and molybdenum oxides.

  2. Irradiation effect on deuterium behaviour in low-dose HFIR neutron-irradiated tungsten

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

    Shimada, Masashi; Cao, G.; Otsuka, T.; Hara, M.; Kobayashi, M.; Oya, Y.; Hatano, Y.

    2015-01-01T23:59:59.000Z

    Tungsten samples were irradiated by neutrons in the High Flux Isotope Reactor (HFIR), Oak Ridge National Laboratory at reactor coolant temperatures of 50–70 ?C to low displacement damage of 0.025 and 0.3 dpa. After cooling down, the HFIR neutronirradiated tungsten samples were exposed to deuterium plasmas in the Tritium Plasma Experiment, Idaho National Laboratory at 100, 200 and 500 ?C twice at the ion fluence of 5×1025 m-2 to reach the total ion fluence of 1×1026 m-2 in order to investigate maximum near-surface (more »in 0.3 dpa samples. The large discrepancy between the total retention via thermal desorption spectroscopy and the nearsurface retention via nuclear reaction analysis indicated the deuterium was trapped in bulk (at least 50µm depth for 0.025 dpa and 35µm depth for 0.3 dpa) at 500 ?C cases even in the relatively low ion fluence of 1026 m-2.« less

  3. Tungsten oxide-Prussian blue electrochromic system based on a proton-conducting polymer electrolyte

    SciTech Connect (OSTI)

    Ho, K.C.; Rukavina, T.G.; Greenberg, C.B. (PPG Industries, Inc., Pittsburgh, PA (United States). Glass Technology Center)

    1994-08-01T23:59:59.000Z

    A new solid-state electrochromic system is presented. It is transparent and is comprised of a tungsten oxide and Prussian blue (PB) thin film couple in combination with a proton-conducting, solid polymer electrolyte. This electrochromic system exhibits rapid and deep optical switching; characteristics of a complementary configuration, both electrochromic films color and bleach in phase. Complementary electrochromic cells with the tungsten oxide-PB couple have previously been based on Li[sup +] or K[sup +]-conducting electrolytes. A repetitively cycling cell has not previously been reported with a proton-conducting solid polymer electrolyte. The devices were operated at low applied voltages, +1.2 V to darken and [minus]0.6 V to bleach. Repeated reduction and oxidation of the current system over 20,000 cycles has been demonstrated, indicating a large number of switchings without great degradation or irreversible side reactions. The sustained, high overall coloration efficiency of the devices suggests the insertion/extraction of protons into and out of both WO[sub 3] and PB films. The effects of cell size and operating temperature on the switching response are discussed.

  4. Reaction and spectroscopic study of silica-supported molybdenum(IV) and tungsten(IV) dimers

    SciTech Connect (OSTI)

    Sullivan, D.L.; Roark, R.D.; Ekerdt, J.G. [Univ. of Texas, Austin, TX (United States); Deutsch, S.E.; Gates, B.C. [Univ. of California, Davis, CA (United States)

    1995-03-16T23:59:59.000Z

    Cyclopentadienyl molybdenum di- and tricarbonyl dimer and cyclopentadienyl tungsten di- and tricarbonyl dimer complexes were added to silica as precursors to supported metal dimers. These complexes are shown to yield metal dimers following attachment to the silica and carbonyl ligand removal. Reductive carbonyl coupling of acetaldehyde and acetone was used as a molecular probe to determine whether dimers formed, with each metal atom being in the 4+ oxidation state. Acetaldehyde and acetone reductively coupled to produce cis- and trans-2-butenes and 2,3-dimethyl-2-butene, respectively. Diolates formed as intermediate products during the coupling reaction. Infrared bands were observed at 2969, 2925, and 2859 cm-1 that correspond to {nu}{sub asym}(CH{sub 3}), {nu}(CH), and {nu}{sub sym}(CH{sub 3}), respectively, for the 2,3-butanediolate formed from acetaldehyde. The hydrogens on the methyl groups for the acetone reductive coupling intermediate, 2,3-dimethyl-2,3-butanediolate, were not equivalent, resulting in the appearance of three C-H stretching frequencies at 2977, 2939, and 2891 cm{sup {minus}1} that are assigned to A{prime}{sub asym}, A{prime}, A{prime}{sub sym} of CH{sub 3}, respectively. Extended X-ray absorption fine structure (EXAFS) spectroscopy was used to characterize a sample prepared from cyclopentadienyl tungsten dicarbonyl dimer on silica. 74 refs., 7 figs., 5 tabs.

  5. Tungsten Nanowire Based Hyperbolic Metamaterial Emitters for Near-field Thermophotovoltaic Applications

    E-Print Network [OSTI]

    Chang, Jui-Yung; Wang, Liping

    2014-01-01T23:59:59.000Z

    Recently, near-field radiative heat transfer enhancement across nanometer vacuum gaps has been intensively studied between two hyperbolic metamaterials (HMMs) due to unlimited wavevectors and high photonic density of state. In this work, we theoretically analyze the energy conversion performance of a thermophotovoltaic (TPV) cell made of In0.2Ga0.8Sb when paired with a HMM emitter composed of tungsten nanowire arrays embedded in Al2O3 host at nanometer vacuum gaps. Fluctuational electrodynamics integrated with effective medium theory and anisotropic thin-film optics is used to calculate the near-field radiative heat transfer. It is found that the spectral radiative energy is enhanced by the epsilon-near-zero and hyperbolic modes at different polarizations. As a result, the power output from a semi-infinite TPV cell is improved by 1.85 times with the nanowire HMM emitter over that with a plain tungsten emitter at a vacuum gap of 10 nm. Moreover, by using a thin TPV cell with 10 um thickness, the conversion eff...

  6. Dynamics of tungsten hexacarbonyl, dicobalt octacarbonyl, and their fragments adsorbed on silica surfaces

    SciTech Connect (OSTI)

    Muthukumar, Kaliappan; Valentí, Roser; Jeschke, Harald O. [Institut für Theoretische Physik, Goethe-Universität Frankfurt, Max-von-Laue-Straße 1, 60438 Frankfurt am Main (Germany)] [Institut für Theoretische Physik, Goethe-Universität Frankfurt, Max-von-Laue-Straße 1, 60438 Frankfurt am Main (Germany)

    2014-05-14T23:59:59.000Z

    Tungsten and cobalt carbonyls adsorbed on a substrate are typical starting points for the electron beam induced deposition of tungsten or cobalt based metallic nanostructures. We employ first principles molecular dynamics simulations to investigate the dynamics and vibrational spectra of W(CO){sub 6} and W(CO){sub 5} as well as Co{sub 2}(CO){sub 8} and Co(CO){sub 4} precursor molecules on fully and partially hydroxylated silica surfaces. Such surfaces resemble the initial conditions of electron beam induced growth processes. We find that both W(CO){sub 6} and Co{sub 2}(CO){sub 8} are stable at room temperature and mobile on a silica surface saturated with hydroxyl groups (OH), moving up to half an Angström per picosecond. In contrast, chemisorbed W(CO){sub 5} or Co(CO){sub 4} ions at room temperature do not change their binding site. These results contribute to gaining fundamental insight into how the molecules behave in the simulated time window of 20 ps and our determined vibrational spectra of all species provide signatures for experimentally distinguishing the form in which precursors cover a substrate.

  7. Irradiation effect on deuterium behaviour in low-dose HFIR neutron-irradiated tungsten

    SciTech Connect (OSTI)

    Shimada, Masashi [Idaho National Lab. (INL), Idaho Falls, ID (United States).Fusion Safety Program; Cao, G. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Engineering Physics; Otsuka, T. [Kyushu Univ., Fukuoka (Japan). Interdisciplinary Graduate School of Engineering Science; Hara, M. [Univ. of Toyama (Japan). Hydrogen Isotope Center; Kobayashi, M. [Shizuoka Univ. (Japan). Radioscience Research Lab.; Oya, Y. [Shizuoka Univ. (Japan). Radioscience Research Lab.; Hatano, Y. [Shizuoka Univ. (Japan). Radioscience Research Lab.

    2015-01-01T23:59:59.000Z

    Tungsten samples were irradiated by neutrons in the High Flux Isotope Reactor (HFIR), Oak Ridge National Laboratory at reactor coolant temperatures of 50–70 ?C to low displacement damage of 0.025 and 0.3 dpa. After cooling down, the HFIR neutronirradiated tungsten samples were exposed to deuterium plasmas in the Tritium Plasma Experiment, Idaho National Laboratory at 100, 200 and 500 ?C twice at the ion fluence of 5×1025 m-2 to reach the total ion fluence of 1×1026 m-2 in order to investigate maximum near-surface (<5µm depth) deuterium concentration increased from 0.5 at% D/W in 0.025 dpa samples to 0.8 at% D/W in 0.3 dpa samples. The large discrepancy between the total retention via thermal desorption spectroscopy and the nearsurface retention via nuclear reaction analysis indicated the deuterium was trapped in bulk (at least 50µm depth for 0.025 dpa and 35µm depth for 0.3 dpa) at 500 ?C cases even in the relatively low ion fluence of 1026 m-2.

  8. A Conceptual Multi-Megawatt System Based on a Tungsten CERMET Reactor

    SciTech Connect (OSTI)

    Jonathan A. Webb; Brian Gross

    2011-02-01T23:59:59.000Z

    Abstract. A conceptual reactor system to support Multi-Megawatt Nuclear Electric Propulsion is investigated within this paper. The reactor system consists of a helium cooled Tungsten-UN fission core, surrounded by a beryllium neutron reflector and 13 B4C control drums coupled to a high temperature Brayton power conversion system. Excess heat is rejected via carbon reinforced heat pipe radiators and the gamma and neutron flux is attenuated via segmented shielding consisting of lithium hydride and tungsten layers. Turbine inlet temperatures ranging from 1300 K to 1500 K are investigated for their effects on specific powers and net electrical outputs ranging from 1 MW to 100 MW. The reactor system is estimated to have a mass, which ranges from 15 Mt at 1 MWe and a turbine inlet temperature of 1500 K to 1200 Mt at 100 MWe and a turbine temperature of 1300 K. The reactor systems specific mass ranges from 32 kg/kWe at a turbine inlet temperature of 1300 K and a power of 1 MWe to 9.5 kg/kW at a turbine temperature of 1500 K and a power of 100 MWe.

  9. Precision Luminosity for $Z^{0}$ Lineshape Measurements with a Silicon-Tungsten Calorimeter

    E-Print Network [OSTI]

    Abbiendi, G; Alexander, Gideon; Allison, J; Anderson, K J; Anderson, S; Arcelli, S; Asai, S; Ashby, S F; Axen, D A; Azuelos, Georges; Ball, A H; Barberio, E; Barlow, R J; Batley, J Richard; Baumann, S; Bechtluft, J; Behnke, T; Bell, K W; Bella, G; Bellerive, A; Bentvelsen, Stanislaus Cornelius Maria; Bethke, Siegfried; Betts, S; Biebel, O; Biguzzi, A; Bloodworth, Ian J; Bock, P; Böhme, J; Boeriu, O; Bonacorsi, D; Boutemeur, M; Braibant, S; Bright-Thomas, P G; Brigliadori, L; Brown, R M; Burckhart, Helfried J; Capiluppi, P; Carnegie, R K; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Chrisman, D; Ciocca, C; Clarke, P E L; Clay, E; Cohen, I; Conboy, J E; Cooke, O C; Couchman, J; Couyoumtzelis, C; Coxe, R L; Cuffiani, M; Dado, S; Dallavalle, G M; Dallison, S; Darling, C L; Davis, R; De Jong, S; de Roeck, A; Dervan, P J; Desch, Klaus; Dienes, B; Dixit, M S; Donkers, M; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Estabrooks, P G; Etzion, E; Evans, H; Fabbri, Franco Luigi; Fanfani, A; Fanti, M; Faust, A A; Feld, L; Ferrari, P; Fiedler, F; Fierro, M; Fleck, I; Foucher, M; Frey, A; Fürtjes, A; Futyan, D I; Gagnon, P; Gary, J W; Gascon-Shotkin, S M; Gaycken, G; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Giacomelli, R; Gibson, W R; Gingrich, D M; Glenzinski, D A; Goldberg, J; Gorn, W; Grandi, C; Graham, K; Gross, E; Grunhaus, Jacob; Gruwé, M; Hajdu, C; Hanson, G G; Hansroul, M; Hapke, M; Harder, K; Harel, A; Hargrove, C K; Harin-Dirac, M; Hart, P; Hauschild, M; Hawkes, C M; Hawkings, R; Hemingway, Richard J; Herten, G; Heuer, R D; Hildreth, M D; Hill, J C; Hillier, S J; Hobson, P R; Höcker, Andreas; Hoffman, K; Homer, R James; Honma, A K; Horváth, D; Hossain, K R; Howard, R; Hüntemeyer, P; Igo-Kemenes, P; Imrie, D C; Ishii, K; Jacob, F R; Jawahery, A; Jeremie, H; Jimack, Martin Paul; Jones, C R; Jovanovic, P; Junk, T R; Kanaya, N; Kanzaki, J I; Karlen, D A; Kartvelishvili, V G; Kawagoe, K; Kawamoto, T; Kayal, P I; Keeler, Richard K; Kellogg, R G; Kennedy, B W; Kim, D H; Kirk, J; Klier, A; Kobayashi, T; Kobel, M; Kokott, T P; Kolrep, M; Komamiya, S; Kowalewski, R V; Kress, T; Krieger, P; Von Krogh, J; Kühl, T; Kyberd, P; Lai, W P; Lafferty, G D; Lahmann, R; Landsman, Hagar Yaël; Lanske, D; Lauber, J; Lawson, I; Layter, J G; Lee, A M; Lellouch, Daniel; Letts, J; Levinson, L; Liebisch, R; Lillich, J; List, B; Littlewood, C; Lloyd, A W; Lloyd, S L; Loebinger, F K; Long, G D; Losty, Michael J; Lü, J; Ludwig, J; Liu, D; Macchiolo, A; MacPherson, A L; Mader, W F; Mannelli, M; Marcellini, S; Marchant, T E; Martin, A J; Martin, J P; Martínez, G; Mashimo, T; Mättig, P; McDonald, W J; McKenna, J A; McKigney, E A; McMahon, T J; McPherson, R A; Meijers, F; Méndez-Lorenzo, P; Menke, S; Merritt, F S; Mes, H; Meyer, I; Michelini, Aldo; Mihara, S; Mikenberg, G; Miller, D J; Mohr, W; Montanari, A; Mori, T; Müller, U; Nagai, K; Nakamura, I; Neal, H A; Nisius, R; O'Neale, S W; Oakham, F G; Odorici, F; Ögren, H O; Okpara, A N; Oreglia, M J; Orito, S; Palmonari, F; Pásztor, G; Pater, J R; Patrick, G N; Patt, J; Pérez-Ochoa, R; Petzold, S; Pfeifenschneider, P; Pilcher, J E; Pinfold, James L; Plane, D E; Poffenberger, P R; Poli, B; Polok, J; Przybycien, M B; Quadt, A; Raith, B A; Rembser, C; Rick, Hartmut; Robertson, S; Robins, S A; Rodning, N L; Roney, J M; Rosati, S; Roscoe, K; Rossi, A M; Rozen, Y; Runge, K; Runólfsson, O; Rust, D R; Sachs, K; Saeki, T; Sahr, O; Sang, W M; Sarkisyan-Grinbaum, E; Sbarra, C; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schieck, J; Schmitt, B; Schmitt, S; Schöning, A; Schröder, M; Schumacher, M; Schwick, C; Scott, W G; Seuster, R; Shears, T G; Shen, B C; Shepherd-Themistocleous, C H; Sherwood, P; Siroli, G P; Skuja, A; Smith, A M; Snow, G A; Sobie, Randall J; Söldner-Rembold, S; Spagnolo, S; Springer, W; Sproston, M; Stahl, A; Stephens, K; Stoll, K; Strom, D; Ströhmer, R; Surrow, B; Talbot, S D; Taras, P; Tarem, S; Tecchio, M; Teuscher, R; Thiergen, M; Thomas, J; Thomson, M A; Torrence, E; Towers, S; Trefzger, T M; Trigger, I; Trócsányi, Z L; Tsur, E; Turner-Watson, M F; Ueda, I; Van Kooten, R; Vannerem, P; Verzocchi, M; Voss, H; Wäckerle, F; Wagner, A; Wagner, D; Waller, D; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wermes, N; Wetterling, D; White, J S; Wilson, G W; Wilson, J A; Wyatt, T R; Yamashita, S; Zacek, V; Zer-Zion, D

    2000-01-01T23:59:59.000Z

    The measurement of small-angle Bhabha scattering is used to determine the luminosity at the OPAL interaction point for the LEP I data recorded between 1993 and 1995. The measurement is based on the OPAL Silicon-Tungsten Luminometer which is composed of two calorimeters encircling the LEP beam pipe, on opposite sides of the interaction point. The luminometer detects electrons from small-angle Bhabha scattering at angles between 25 and 58mrad. At LEP center-of-mass energies around the Z0, about half of all Bhabha electrons entering the detector fall within a 79nb fiducial acceptance region. The electromagnetic showers generated in the stack of 1 radiation length tungsten absorber plates are sampled by 608 silicon detectors with 38,912 radial pads of 2.5mm width.The fine segmentation of the detector, combined with the precise knowledge of its physical dimensions, allows the trajectories of incoming 45GeV electrons or photons to be determined with a total systematic error of less than 7microns. We have quantified...

  10. Vaccum Gas Tungsten Arc Welding, phase 1. Technical report, October 1993-March 1995

    SciTech Connect (OSTI)

    Weeks, J.L.; Krotz, P.D.; Todd, D.T.; Liaw, Y.K.

    1995-03-01T23:59:59.000Z

    This two year program will investigate Vacuum Gas Tungsten Arc Welding (VGTAW) as a method to modify or improve the weldability of normally difficult-to-weld materials. VGTAW appears to offer a significant improvement in weldability because of the clean environment and lower heat input needed. The overall objective of the program is to develop the VGTAW technology and implement it into a manufacturing environment that will result in lower cost, better quality and higher reliability aerospace components for the space shuttle and other NASA space systems. Phase 1 of this program was aimed at demonstrating the process`s ability to weld normally difficult-to-weld materials. Phase 2 will focus on further evaluation, a hardware demonstration and a plan to implement VGTAW technology into a manufacturing environment. During Phase 1, the following tasks were performed: (1) Task 11000 Facility Modification - an existing vacuum chamber was modified and adapted to a GTAW power supply; (2) Task 12000 Materials Selection - four difficult-to-weld materials typically used in the construction of aerospace hardware were chosen for study; (3) Task 13000 VGTAW Experiments - welding experiments were conducted under vacuum using the hollow tungsten electrode and evaluation. As a result of this effort, two materials, NARloy Z and Incoloy 903, were downselected for further characterization in Phase 2; and (4) Task 13100 Aluminum-Lithium Weld Studies - this task was added to the original work statement to investigate the effects of vacuum welding and weld pool vibration on aluminum-lithium alloys.

  11. Comproportionation of Cationic and Anionic Tungsten Complexes Having an N-Heterocyclic Carbene Ligand to Give the Isolable 17-Electron Tungsten Radical, CpW(CO)2(IMes)•

    SciTech Connect (OSTI)

    Roberts, John A.; Franz, James A.; van der Eide, Edwin F.; Walter, Eric D.; Petersen, Jeffrey L.; DuBois, Daniel L.; Bullock, R. Morris

    2011-09-21T23:59:59.000Z

    A series consisting of a tungsten anion, radical and cation, supported by the N-heterocyclic carbene IMes (1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene) and spanning formal oxidation states W(0), W(I) and W(II), has been synthesized, isolated, and characterized. Reaction of the hydride CpW(CO)2(IMes)H with KH and 18 crown 6 gives the tungsten anion [CpW(CO)2(IMes)]-[K(18 crown 6)]+. The crystal structure of this complex shows that the K+ interacts not only with the oxygen atoms in the crown ether, but also with the carbonyl oxygens. The electrochemical oxidation of [CpW(CO)2(IMes)]- in acetonitrile is fully reversible (E½ = ?1.65 V vs Cp2Fe+•/0) at all scan rates, indicating that CpW(CO)2(IMes)• is a persistent radical. Hydride transfer from CpW(CO)2(IMes)H to Ph3C+PF6 affords [cis-CpW(CO)2(IMes)(MeCN)]+PF6 . Comproportionation of [CpW(CO)2(IMes)]- with [CpW(CO)2(IMes)(MeCN)]+ gives the 17-electron tungsten radical CpW(CO)2(IMes)•. This complex shows paramagnetically shifted resonances in 1H NMR spectra and has been characterized by IR spectroscopy, low-temperature EPR spectroscopy, and X-ray diffraction. CpW(CO)2(IMes)• is very stable with respect to disproportionation and dimerization. NMR studies of degenerate electron transfer between CpW(CO)2(IMes)• and [CpW(CO)2(IMes)]- are reported. DFT calculations were carried out on CpW(CO)2(IMes)H, as well as on related complexes bearing NHC ligands with N,N´ substituents Me [CpW(CO)2(IMe)H] or H [CpW(CO)2(IH)H] to compare to the experimentally studied IMes complexes with mesityl substituents. These calculations reveal W H homolytic bond dissociation energies (BDEs) to decrease with increasing steric bulk of the NHC ligand, from 67 for CpW(CO)2(IH)H to 64 for CpW(CO)2(IMe)H to 63 kcal/mol for CpW(CO)2(IMes)H. The calculated spin density at W for CpW(CO)2(IMes)• is 0.63. The W radicals CpW(CO)2(IMe)• and CpW(CO)2(IH)• are calculated to form weak W W bonds. The weakly bonded complexes [CpW(CO)2(IMe)]2 and [CpW(CO)2(IH)]2, are predicted to have W-W BDEs of 6 and 18 kcal/mol, respectively, and to dissociate readily to the W-centered radicals CpW(CO)2(IMe)• and CpW(CO)2(IH)•. This work was supported by the US Department of Energy Basic Energy Sciences' Chemical Sciences, Geosciences & Biosciences Division. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  12. Line spectrum and ion temperature measurements from tungsten ions at low ionization stages in large helical device based on vacuum ultraviolet spectroscopy in wavelength range of 500–2200 Å

    SciTech Connect (OSTI)

    Oishi, T., E-mail: oishi@LHD.nifs.ac.jp; Morita, S.; Goto, M. [National Institute for Fusion Science, 322-6, Oroshi-cho, Toki 509-5292 (Japan); Department of Fusion Science, Graduate University for Advanced Studies, 322-6, Oroshi-cho, Toki 509-5292 (Japan); Huang, X. L.; Zhang, H. M. [Department of Fusion Science, Graduate University for Advanced Studies, 322-6, Oroshi-cho, Toki 509-5292 (Japan)

    2014-11-15T23:59:59.000Z

    Vacuum ultraviolet spectra of emissions released from tungsten ions at lower ionization stages were measured in the Large Helical Device (LHD) in the wavelength range of 500–2200 Å using a 3 m normal incidence spectrometer. Tungsten ions were distributed in the LHD plasma by injecting a pellet consisting of a small piece of tungsten metal and polyethylene tube. Many lines having different wavelengths from intrinsic impurity ions were observed just after the tungsten pellet injection. Doppler broadening of a tungsten candidate line was successfully measured and the ion temperature was obtained.

  13. Growth and field-emission property of tungsten oxide nanotip arrays Jun Zhou, Li Gong, Shao Zhi Deng,a

    E-Print Network [OSTI]

    Wang, Zhong L.

    and Engineering, SunYat-Sen (Zhongshan) University, Guangzhou, 510275, China Rusen Yang and Zhong Lin Wangb School in the threshold field.14­16 Tungsten oxide is a very important semiconductor. It has been found to be of great- tion deposition process. The experimental setup consists of a vacuum chamber 300 mm 400 mm , two copper

  14. Materials Corrosion and Mitigation Strategies for APT: Corrosion of Tungsten in an 800 MeV Proton Beam at the

    E-Print Network [OSTI]

    Materials Corrosion and Mitigation Strategies for APT: Corrosion of Tungsten in an 800 MeV Proton Beam at the Weapons Neutron Research Facility R. Scott Lillard, Darryl P. Butt Materials Corrosion corrosion. Energy deposition and thermal hydraulic calculations predict that the surface temperature

  15. Tungsten Coating on Low Activation Vanadium Alloy by Plasma Spray Process

    SciTech Connect (OSTI)

    Nagasaka, Takuya [National Institute for Fusion Science (Japan); Muroga, Takeo [National Institute for Fusion Science (Japan); Noda, Nobuaki [National Institute for Fusion Science (Japan); Kawamura, Masashi [Kawasaki Heavy Industries, LTD (Japan); Ise, Hideo [Kawasaki Heavy Industries, LTD (Japan); Kurishita, Hiroaki [Tohoku University (Japan)

    2005-05-15T23:59:59.000Z

    Tungsten (W) coating on fusion candidate V-4Cr-4Ti (NIFS-HEAT-2) substrate was demonstrated with plasma spray process for the purpose of applying to protection of the plasma facing surface of a fusion blanket. Increase in plasma input power and temperature of the substrate was effective to reduce porosity of the coating, but resulted in hardening of the substrate and degradation of impact property at 77 K. The hardening seemed to be due to contamination with gaseous impurities and deformation by thermal stress during the coating process. Since all the samples showed good ductility at room temperature, further heating seems to be acceptable for the vanadium substrate. The fracture stress of the W coating was estimated from bending tests as at least 313 MPa, which well exceeds the design stress for the vanadium structure in fusion blanket.

  16. THE REMOVAL OF CARBON/BEUTERIUM FROM STAINLESS STEEL AND TUNGSTEN BY TRANSFERRED-ARC CLEANING

    SciTech Connect (OSTI)

    K. J. HOLLIS; R. G. CASTRO; ET AL

    2001-04-01T23:59:59.000Z

    Tungsten and stainless steel samples have been contaminated with deuterium and carbon to simulate deposited layers in magnetic-confinement fusion devices. Deuterium and carbon were co-deposited onto the sample surfaces using a deuterium plasma seeded with varying amounts of deuterated methane. Deuterium was also implanted into the samples in an accelerator to simulate hydrogen isotope ion implantation conditions in magnetic confinement fusion devices. Cathodic arc, or transferred-arc (TA) cleaning was employed to remove the deposits from the samples. The samples were characterized by ion beam analysis both before and after cleaning to determine deuterium and carbon concentrations present. The deuterium content was greatly reduced by the cleaning thus demonstrating the possibility of using the TA cleaning technique for removing deuterium and/or tritium from components exposed to D-T fuels. Removal of surface layers and significant reduction of subsurface carbon concentrations was also observed.

  17. The solution growth route and characterization of electrochromic tungsten oxide thin films

    SciTech Connect (OSTI)

    Todorovski, Toni [Institute of Chemistry, Faculty of Natural Sciences and Mathematics, Sts. Cyril and Methodius University, PO Box 162, Arhimedova 5, 1000 Skopje (Macedonia, The Former Yugoslav Republic of); Najdoski, Metodija [Institute of Chemistry, Faculty of Natural Sciences and Mathematics, Sts. Cyril and Methodius University, PO Box 162, Arhimedova 5, 1000 Skopje (Macedonia, The Former Yugoslav Republic of)], E-mail: metonajd@iunona.pmf.ukim.edu.mk

    2007-12-04T23:59:59.000Z

    Electrochromic tungsten oxide thin films were prepared by using an aqueous solution of Na{sub 2}WO{sub 4}.2H{sub 2}O and dimethyl sulfate. Various techniques were used for the characterization of the films such as X-ray diffraction, cyclic voltammetry, SEM analysis and VIS-spectroscopy. The thin film durability was tested in an aqueous solution of LiClO{sub 4} (0.1 mol/dm{sup 3}) for about 7000 cycles followed by cyclic voltammetry. No significant changes in the cyclic voltammograms were found, thus proving the high durability of the films. The optical transmittance spectra of coloured and bleached states showed significant change in the transmittance, which makes these films favorable for electrochromic devices.

  18. Transmission spectra of an electrochromic window based on polyaniline, Prussian blue and tungsten oxide

    SciTech Connect (OSTI)

    Jelle, B.P.; Hagen, G. [Norwegian Inst. of Tech., Trondheim (Norway). Dept. of Applied Electrochemistry

    1993-12-01T23:59:59.000Z

    The demand for energy savings in buildings will increase in the coming years, as the world`s attention is drawn towards environmental aspects and energy economizing. Windows which are able to dynamically control the sun radiation throughput will play an important role. In this respect, the authors have studied two different electrochromic window configurations; one based on the two complementary electrochromic materials polyaniline (PANI) and tungsten oxide (WO{sub 3}), the other one with the electrochromic coating Prussian blue (PB) in addition to PANI and WO{sub 3}. The inclusion of PB enhances the transmission modulation. Integrating over the solar spectrum they find that the window based on PANI and WO{sub 3} is able to regulate 39% of the total solar energy, while with the inclusion of PB they manage to regulate as much as 50% of the sun radiation.

  19. Nanostructuring of molybdenum and tungsten surfaces by low-energy helium ions

    SciTech Connect (OSTI)

    De Temmerman, Gregory; Bystrov, Kirill; Zielinski, Jakub J.; Balden, Martin; Matern, Gabriele; Arnas, Cecile; Marot, Laurent [FOM Institute DIFFER, Ducth Institute For Fundamental Energy Research, Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Max Planck Institute for Plasma Physics, EURATOM Association, 85748 Garching (Germany); Laboratoire PIIM, CNRS/Aix-Marseille Universit, 13397 Marseille (France); Department of Physics, University of Basel, Basel, CH-4056 (Switzerland)

    2012-07-15T23:59:59.000Z

    The formation of metallic nanostructures by exposure of molybdenum and tungsten surfaces to high fluxes of low energy helium ions is studied as a function of the ion energy, plasma exposure time, and surface temperature. Helium plasma exposure leads to the formation of nanoscopic filaments on the surface of both metals. The size of the helium-induced nanostructure increases with increasing surface temperature while the thickness of the modified layer increases with time. In addition, the growth rate of the nanostructured layer also depends on the surface temperature. The size of the nanostructure appears linked with the size of the near-surface voids induced by the low energy ions. The results presented here thus demonstrate that surface processing by low-energy helium ions provides an efficient route for the formation of porous metallic nanostructures.

  20. Rapid additive manufacturing of MR compatible multipinhole collimators with selective laser melting of tungsten powder

    SciTech Connect (OSTI)

    Deprez, Karel; Vandenberghe, Stefaan; Van Audenhaege, Karen; Van Vaerenbergh, Jonas; Van Holen, Roel [MEDISIP, Department of Electronics and Information Systems, Ghent University-iMinds-IBiTech, De Pintelaan 185, B-9000 Ghent (Belgium); Layerwise NV, Kapeldreef 60, 3001 Leuven (Belgium); MEDISIP, Department of Electronics and Information Systems, Ghent University-iMinds-IBiTech, De Pintelaan 185, B-9000 Ghent (Belgium)

    2013-01-15T23:59:59.000Z

    Purpose: The construction of complex collimators with a high number of oblique pinholes is very labor intensive, expensive or is sometimes impossible with the current available techniques (drilling, milling or electric discharge machining). All these techniques are subtractive: one starts from solid plates and the material at the position of the pinholes is removed. The authors used a novel technique for collimator construction, called metal additive manufacturing. This process starts with a solid piece of tungsten on which a first layer of tungsten powder is melted. Each subsequent layer is then melted on the previous layer. This melting is done by selective laser melting at the locations where the CAD design file defines solid material. Methods: A complex collimator with 20 loftholes with 500 {mu}m diameter pinhole opening was designed and produced (16 mm thick and 70 Multiplication-Sign 52 mm{sup 2} transverse size). The density was determined, the production accuracy was measured (GOM ATOS II Triple Scan, Nikon AZ100M microscope, Olympus IMT200 microscope). Point source measurements were done by mounting the collimator on a SPECT detector. Because there is increasing interest in dual-modality SPECT-MR imaging, the collimator was also positioned in a 7T MRI scanner (Bruker Pharmascan). A uniform phantom was acquired using T1, T2, and T2* sequences to check for artifacts or distortion of the phantom images due to the collimator presence. Additionally, three tungsten sample pieces (250, 500, and 750 {mu}m thick) were produced. The density, attenuation (140 keV beam), and uniformity (GE eXplore Locus SP micro-CT) of these samples were measured. Results: The density of the collimator was equal to 17.31 {+-} 0.10 g/cm{sup 3} (89.92% of pure tungsten). The production accuracy ranges from -260 to +650 {mu}m. The aperture positions have a mean deviation of 5 {mu}m, the maximum deviation was 174 {mu}m and the minimum deviation was -122 {mu}m. The mean aperture diameter is 464 {+-} 19 {mu}m. The calculated and measured sensitivity and resolution of point sources at different positions in the field-of-view agree well. The measured and expected attenuation of the three sample pieces are in a good agreement. There was no influence of the 7T magnetic field on the collimator (which is paramagnetic) and minimal distortion was noticed on the MR scan of the uniform phantom. Conclusions: Additive manufacturing is a very promising technique for the production of complex multipinhole collimators and may also be used for producing other complex collimators. The cost of this technique is only related to the amount of powder needed and the time it takes to have the collimator built. The timeframe from design to collimator production is significantly reduced.

  1. Failure of semiclassical models to describe resistivity of nanometric, polycrystalline tungsten films

    SciTech Connect (OSTI)

    Choi, Dooho [Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States); Korea Railroad Research Institute, 360-1 Woulam, Uiwang, Kyunggi 437-757 (Korea, Republic of); Liu, Xuan [Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States); Schelling, Patrick K. [Advanced Materials Processing and Analysis Center and Department of Physics, University of Central Florida, 4000 Central Florida Boulevard, Orlando, Florida 32816 (United States); Coffey, Kevin R. [Department of Materials Science and Engineering, University of Central Florida, 4000 Central Florida Boulevard, Orlando, Florida 32816 (United States); Barmak, Katayun [Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States); Department of Applied Physics and Applied Mathematics, Columbia University, 500 West 120th Street, New York, New York 10027 (United States)

    2014-03-14T23:59:59.000Z

    The impact of electron scattering at surfaces and grain boundaries in nanometric polycrystalline tungsten (W) films was studied. A series of polycrystalline W films ranging in thickness from 10 to 310?nm and lateral grain size from 74 to 133?nm were prepared on thermally oxidized Si. The Fuchs-Sondheimer surface-scattering model and Mayadas-Shatzkes grain-boundary scattering model were employed for quantitative analyses. Predictions from the theoretical models were found to deviate systematically from the experimental data. Possible reasons for the failure of the theoretical models to describe the experimental data are explored. Finally, a discussion of the crucial features lacking from existing models is presented, along with possible avenues for improving the models to result in better agreement with experimental data.

  2. On vapor shielding of dust grains of iron, molybdenum, and tungsten in fusion plasmas

    SciTech Connect (OSTI)

    Brown, B. T.; Smirnov, R. D., E-mail: rsmirnov@ucsd.edu; Krasheninnikov, S. I. [Department of Mechanical and Aerospace Engineering, University of California, San Diego, 9500 Gilman Dr., La Jolla, California 92093-0411 (United States)] [Department of Mechanical and Aerospace Engineering, University of California, San Diego, 9500 Gilman Dr., La Jolla, California 92093-0411 (United States)

    2014-02-15T23:59:59.000Z

    The shielding effects of ablation cloud around a small dust grain composed of iron, molybdenum, or tungsten in fusion plasmas are considered. These include collisional dissipation of momentum flux of impinging plasma ions, heat transfer by secondary plasma created due to electron impact ionization of the ablated atoms, and radiative plasma power losses in the ablation cloud. The maximum radius, which limits applicability of existing dust-plasma interaction models neglecting the cloud shielding effects, for dust grains of the considered high-Z metals is calculated as function of plasma parameters. The thermal bifurcation triggered by thermionic electron emission from dust grains, observed for some of the considered materials, is analyzed. The results are compared with previous calculations for dust composed of low-Z fusion related materials, i.e., lithium, beryllium, and carbon.

  3. Oxygen plasma immersion ion implantation treatment to enhance data retention of tungsten nanocrystal nonvolatile memory

    SciTech Connect (OSTI)

    Wang, Jer-Chyi, E-mail: jcwang@mail.cgu.edu.tw; Chang, Wei-Cheng; Lai, Chao-Sung, E-mail: cslai@mail.cgu.edu.tw [Department of Electronic Engineering, Chang Gung University, Kweishan 333, Taoyuan, Taiwan (China); Chang, Li-Chun [Department of Material Engineering and Center for Thin Film Technologies and Applications, Ming Chi University of Technology, Taishan 24301, New Taipei City, Taiwan (China); Ai, Chi-Fong; Tsai, Wen-Fa [Institute of Nuclear Energy Research, Atomic Energy Council, Longtan 325, Taoyuan, Taiwan (China)

    2014-03-15T23:59:59.000Z

    Data retention characteristics of tungsten nanocrystal (W-NC) memory devices using an oxygen plasma immersion ion implantation (PIII) treatment are investigated. With an increase of oxygen PIII bias voltage and treatment time, the capacitance–voltage hysteresis memory window is increased but the data retention characteristics become degraded. High-resolution transmission electron microscopy images show that this poor data retention is a result of plasma damage on the tunneling oxide layer, which can be prevented by lowering the bias voltage to 7?kV. In addition, by using the elevated temperature retention measurement technique, the effective charge trapping level of the WO{sub 3} film surrounding the W-NCs can be extracted. This measurement reveals that a higher oxygen PIII bias voltage and treatment time induces more shallow traps within the WO{sub 3} film, degrading the retention behavior of the W-NC memory.

  4. Causal Factors of Weld Porosity in Gas Tungsten Arc Welding of Powder Metallurgy Produced Titanium Alloys

    SciTech Connect (OSTI)

    Muth, Thomas R [ORNL; Yamamoto, Yukinori [ORNL; Frederick, David Alan [ORNL; Contescu, Cristian I [ORNL; Chen, Wei [ORNL; Lim, Yong Chae [ORNL; Peter, William H [ORNL; Feng, Zhili [ORNL

    2013-01-01T23:59:59.000Z

    ORNL undertook an investigation using gas tungsten arc (GTA) welding on consolidated powder metallurgy (PM) titanium (Ti) plate, to identify the causal factors behind observed porosity in fusion welding. Tramp element compounds of sodium and magnesium, residual from the metallothermic reduction of titanium chloride used to produce the titanium, were remnant in the starting powder and were identified as gas forming species. PM-titanium made from revert scrap where sodium and magnesium were absent, showed fusion weld porosity, although to a lesser degree. We show that porosity was attributable to hydrogen from adsorbed water on the surface of the powders prior to consolidation. The removal / minimization of both adsorbed water on the surface of titanium powder and the residues from the reduction process prior to consolidation of titanium powders, are critical to achieve equivalent fusion welding success similar to that seen in wrought titanium produced via the Kroll process.

  5. R&D for a highly granular silicon tungsten electromagnetic calorimeter

    E-Print Network [OSTI]

    Pöschl, R

    2015-01-01T23:59:59.000Z

    This article reports on first experience with the technological prototype of a highly- granular silicon-tungsten electromagnetic calorimeter as envisaged for the detectors at a future lepton collider. In the focus of the analysis is the performance of a highly integrated Application Specific Integrated Circuit designed to meet the requirements in terms of dynamic range, compactness and power consumption. The beam test results show that the circuit will allow a future detector with a signal over noise ratio of at least 10:1. To minimise the power dissipation the ASIC will be operated in a power pulsed mode. So far no conceptual problem was revealed but the studies show the way for further work. The prototype is read out by a DAQ system conceived to meet the needs of a trigger less system with a huge number of readout cells.

  6. Wavelength measurement of n = 3 - n' = 3 transitions in highly charged tungsten ions

    SciTech Connect (OSTI)

    Clementson, J; Beiersdorfer, P

    2010-03-10T23:59:59.000Z

    3s{sub 1/2} - 3p{sub 3/2} and 3p{sub 1/2} - 3d{sub 3/2} transitions have been studied in potassium-like W{sup 55+} through neon-like W{sup 64}+ ions at the electron-beam ion trap facility in Livermore. The wavelengths of the lines have been measured in high resolution relative to well known reference lines from oxygen and nitrogen ions. Using the high-energy SuperEBIT electron-beam ion trap and an R = 44.3 m grazing-incidence soft x-ray spectrometer, the lines were observed with a cryogenic charge-coupled device camera. The wavelength data for the sodium-like and magnesium-like tungsten lines are compared with theoretical predictions for ions along the isoelectronic sequences.

  7. Theoretical analysis of weld pool behavior in the pulsed current Gas Tungsten Arc Welding (GTAW) process

    SciTech Connect (OSTI)

    Tsai, C.L. (Ohio State Univ., Columbus (United States)); Hou, C.A. (Howard Univ., Washington, DC (United States))

    1988-02-01T23:59:59.000Z

    A general three-dimensional, closed-form welding heat-flow solution, which is capable of analyzing thermal behavior of the weldment in its transient state and/or under time-dependent power change during welding, is presented. The analytical model utilizes the finite heat source theory with a Gaussian distribution and also considers the effects of finite plate thickness. The numerical values of the solution are calculated using the computational schemes on a minicomputer. In this paper the welding parameters of the pulsed current Gas Tungsten Arc Welding (GTAW) were studied using the solution. Two sets of pulsation parameters were analyzed and their sensitivity to the heat input control were evaluated.

  8. Catalytic ionic hydrogenation of ketones using tungsten or molybdenum catalysts with increased lifetimes

    DOE Patents [OSTI]

    Bullock, R. Morris; Kimmich, Barbara F.; Fagan, Paul J.; Hauptman, Elisabeth

    2003-09-02T23:59:59.000Z

    The present invention is a process for the catalytic hydrogenation of ketones and aldehydes to alcohols at low temperatures and pressures using organometallic molybdenum and tungsten complexes and the catalyst used in the process. The reactants include a functional group which is selected from groups represented by the formulas R*(C.dbd.O)R' and R*(C.dbd.O)H, wherein R* and R' are selected from hydrogen or any alkyl or aryl group. The process includes reacting the organic compound in the presence of hydrogen and a catalyst to form a reaction mixture. The catalyst is prepared by reacting Ph.sub.3 C.sup.+ A.sup.- with a metal hydride. A.sup.- represents an anion and can be BF.sub.4.sup.-, PF.sub.6.sup.-, CF.sub.3 SO.sub.3.sup.- or Bar'.sub.4.sup.-, wherein Ar'=3,5-bis(trifluoromethyl)phenyl. The metal hydride is represented by the formula: HM(CO).sub.2 [.eta..sup.5 :.eta..sup.1 --C.sub.5 H.sub.4 (XH.sub.2).sub.n PR.sub.2 ] wherein M represents a molybdenum (Mo) atom or a tungsten (W) atom; X is a carbon atom, a silicon atom or a combination of carbon (C) and silicon (Si) atoms; n is any positive integer; R represents two hydrocarbon groups selected from H, an aryl group and an alkyl group, wherein both R groups can be the same or different. The metal hydride is reacted with Ph.sub.3 C.sup.+ A.sup.- either before reacting with the organic compound or in the reaction mixture.

  9. Simultaneous impact of neutron irradiation and sputtering on the surface structure of self–damaged ITER–grade tungsten

    SciTech Connect (OSTI)

    Belyaeva, A. I., E-mail: aibelyaeva@mail.ru; Savchenko, A. A. [National Technical University “Kharkov Politechnical Institute”, Kharkov, 61002 (Ukraine); Galuza, A. A.; Kolenov, I. V. [Institute of Electrophysics and Radiation Technologies, National Academy of Science of Ukraine, Kharkov, 61024 (Ukraine)

    2014-07-15T23:59:59.000Z

    Simultaneous effects of neutron irradiation and long–term sputtering on the surface relief of ITER–grade tungsten were studied. The effects of neutron–induced displacement damage have been simulated by irradiation of tungsten target with W{sup 6+} ions of 20?MeV energy. Ar{sup +} ions with energy 600?eV were used as imitation of charge exchange atoms in ITER. The surface relief was studied after each sputtering act. The singularity in the WJ–IG surface relief was ascertained experimentally at the first time, which determines the law of roughness extension under sputtering. As follows from the experimental data, the neutron irradiation has not to make a decisive additional contribution in the processes developing under impact of charge exchange atoms only.

  10. The effect of tungsten and molybdenum additions on the cavitation corrosion behavior of duplex stainless steel (DSS) in seawater

    SciTech Connect (OSTI)

    Al-Hashem, A.; Abdullah, A.; Shalaby, H.M. [Kuwait Inst. for Scientific Research, Safat (Kuwait). Materials Application Dept.

    1998-12-31T23:59:59.000Z

    Cavitation corrosion studies were conducted on two duplex stainless steel (DSS) specimens of which one was containing tungsten and more molybdenum than the other. Experiments were conducted in seawater using an ultrasonically-induced cavitation facilities. The rate of mass-loss, free corrosion potential, and microscopic examinations were compared for the two alloys in the presence and absence of cavitation. There was negligible mass loss for the two alloys under stagnant conditions. However, some differences were observed between the two alloys with respect to mass-loss, corrosion potential and morphology of attacked areas. The alloy containing tungsten and mover molybdenum experienced more loss in weight regardless of their more noble corrosion potential during cavitation. This difference in behavior was explained in terms of the effect of the alloying elements on the microstructure of the alloys and their susceptibility to absorb the impact energy of cavitation.

  11. March 8, 2001 A. R. Raffray, et al., Assessment of Carbon and Tungsten Dry Chamber Walls under IFE Energy Depositions

    E-Print Network [OSTI]

    Raffray, A. René

    Chamber Walls under IFE Energy Depositions Ion Energy Deposition Calculations Electronic stopping power., Assessment of Carbon and Tungsten Dry Chamber Walls under IFE Energy Depositions Photon and Ion Attenuation for Ions Based on Given Spectrum and 6.5 m Chamber 0.0E+00 1.0E+13 2.0E+13 3.0E+13 4.0E+13 5.0E+13 6.0E+13

  12. The influence of transition metal solutes on dislocation core structure and values of Peierls stress and barrier in tungsten.

    SciTech Connect (OSTI)

    Samolyuk, German D [ORNL; Stoller, Roger E [ORNL; Osetskiy, Yury N [ORNL

    2013-01-01T23:59:59.000Z

    Several transition metals were examined to evaluate their potential for improving the ductility of tungsten. We investigate the dislocation core structure, Peierls stress and barrier of $1/2\\langle111\\rangle$ screw dislocations in binary tungsten-transition metal alloys (W$_{1-x}$TM$_{x}$) based on first principles electronic structure calculations. The periodic quadrupole approach was applied to model the structure of $1/2\\langle111\\rangle$ dislocation. The alloying with transition metals was modeled using the virtual crystal approximation. In order to verify the applicability of this approach, the equilibrium lattice parameter and elastic constants were calculated for tungsten alloyed with the set of transition metals. Reasonable agreement was obtained between results using the virtual crystal approximation and those using both a conventional super-cell approach and existing experimental data. Increasing the concentration of a transition metal from the VIIIA group leads to reduction of the $C^\\prime$ elastic constant and increase of elastic anisotropy A=$C_{44}/C^\\prime$. It was demonstrated that alloying W with a group VIIIA transition metal changes the structure of the dislocation core from symmetric to asymmetric, similar to results obtained for W$_{1-x}$Re$_{x}$ alloys in the earlier work of Romaner {\\it et al} (Phys. Rev. Lett. 104, 195503 (2010)). Following the core symmetry change, the values of the Peierls stress and barrier are reduced. This combination of two effects could lead to increased ductility in a tungsten-based alloy\\comments. Our results demonstrate that similar effects could be achieved with any of the transition metals from the VIIIA group.

  13. Relativistic configuration-interaction calculations of the n=3-3 transition energies in highly charged tungsten ions

    SciTech Connect (OSTI)

    Chen, M. H.; Cheng, K. T. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2011-07-15T23:59:59.000Z

    A large-scale relativistic configuration-interaction calculation of the n=3-3 transition energies for Ne- to Ar-like tungsten is carried out. The calculation is based on the relativistic no-pair Hamiltonian and uses finite B-spline orbitals in a cavity as basis functions. Quantum electrodynamic and mass polarization corrections are also included. Results are compared with other theories and with experiment, and are generally found to be more reliable than previous theoretical predictions.

  14. Employee Spotlights | Argonne National Laboratory

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

    ----Lithium-ion batteries ----Lithium-air batteries ----Sodium batteries --Electricity transmission --Smart Grid -Energy economy --Energy policy Environment -Biology...

  15. Manufacturing Spotlight: Boosting American Competitiveness

    Office of Energy Efficiency and Renewable Energy (EERE)

    Find out how the Energy Department is helping bring new clean energy technologies to the marketplace and make manufacturing processes more energy efficient.

  16. StudentSpotlight January 2009

    E-Print Network [OSTI]

    Anderson, Jim

    3150 #12;October 30th 2008 marked the third anniversary of the fire that destroyed the Mountbatten a phoenix from the ashes of its predecessor," said Head of ECS, Professor Harvey Rutt "It provides

  17. Effects of powder pretreatment on the microstructure and mechanical properties of tungsten heavy alloys. (Reannouncement with new availability information)

    SciTech Connect (OSTI)

    Bedhadjhamida, A.; German, R.M.

    1991-12-31T23:59:59.000Z

    Tungsten heavy alloys exhibit unique properties such as high strength, density, ductility and toughness. Alloying additions of molybdenum to the W-Ni-Fe system have drastically decreased the sintered grain size through the limited solubility of tungsten in the solid solution matrix in the presence of molybdenum. This contributes to additional strengthening but a decrease in the ductility. Recent work has shown that the distribution of molybdenum in the tungsten grains is not uniform after sintering. Homogenous coating of Mo on W is desirable to further decrease solution-reprecipitation during liquid phase sintering. In this work, alloying additions of molybdenum in the W-Ni-Fe system through various methods such as electroless-plating, milling, and mixing of elemental powders are investigated. The effects of these techniques on the final microstructure, densification and mechanical properties are examined using electron microscopy, microprobe analysis, and mechanical testing. The ideal distribution of molybdenum in the microstructure is investigated and the optimum alloying addition technique is singled out. This helps to better understand the processes occurring during liquid phase sintering of these alloys and further improve their mechanical properties.

  18. Effects of surface porosity on tungsten trioxide (WO{sub 3}) films' electrochromic performance

    SciTech Connect (OSTI)

    Lee, W.J.; Fang, Y.K.; Ho, J.J.; Hsieh, W.T.; Ting, S.F.; Huang, Daoyang; Ho, F.C.

    2000-02-01T23:59:59.000Z

    In this paper, the correlation between the electrochromic performance and the surface morphology of the tungsten trioxide (WO{sub 3}) thin films sputtered by dc reactive magnetron sputtering with widely varying target-substrate distances was investigated. It is found that the optical density change ({Delta}OD) of films is strongly affected by the target-substrate distance. The coloration efficiency (CE) at 633 nm was also found to be sensitive to the target-substrate distance, with 16 cm{sup 2}/C of film sputtered at 6 cm and 50 cm{sup 2}/C at 18 cm. X-ray diffraction showed that the crystal structure of films was amorphous. By using atomic force microscope to identify the surface porosity of the sputtered WO{sub 3} films, the authors found that the film at longer target-substrate distance was rough, porous, and having a cone-shaped columns morphology, this offering a good electrochromic performance for opto-switching applications.

  19. Deuterium trapping at defects created with neutron and ion irradiations in tungsten

    SciTech Connect (OSTI)

    Y. Hatano; M. Shimada; T. Otsuka; Y. Oya; V.Kh. Alimov; M. Hara; J. Shi; M. Kobayashi; T. Oda; G. Cao; K. Okuno; T. Tanaka; K. Sugiyama; J. Roth; B. Tyburska-Püschel; J. Dorner; N. Yoshida; N. Futagami; H. Watanabe; M. Hatakeyama; H. Kurishita; M. Sokolov; Y. Katoh

    2013-07-01T23:59:59.000Z

    The effects of neutron and ion irradiations on deuterium (D) retention in tungsten (W) were investigated. Specimens of pure W were irradiated with neutrons to 0.3 dpa at around 323 K and then exposed to high-flux D plasma at 473 and 773 K. The concentration of D significantly increased by neutron irradiation and reached 0.8 at% at 473 K and 0.4 at% at 773 K. Annealing tests for the specimens irradiated with 20 MeV W ions showed that the defects which play a dominant role in the trapping at high temperature were stable at least up to 973 K, while the density decreased at temperatures equal to or above 1123 K. These observations of the thermal stability of traps and the activation energy for D detrapping examined in a previous study (˜1.8 eV) indicated that the defects which contribute predominantly to trapping at 773 K were small voids. The higher concentration of trapped D at 473 K was explained by additional contributions of weaker traps. The release of trapped D was clearly enhanced by the exposure to atomic hydrogen at 473 K, though higher temperatures are more effective for using this effect for tritium removal in fusion reactors.

  20. Tungsten-incorporation induced red-shift in the bandgap of gallium oxide thin films

    SciTech Connect (OSTI)

    Rubio, E. J.; Ramana, C. V. [Department of Mechanical Engineering, University of Texas at El Paso, El Paso, Texas 79968 (United States)] [Department of Mechanical Engineering, University of Texas at El Paso, El Paso, Texas 79968 (United States)

    2013-05-13T23:59:59.000Z

    Tungsten (W) incorporated Ga{sub 2}O{sub 3} films were produced by co-sputter deposition. W-concentration was varied by the applied sputtering-power. The structure and optical properties of W-incorporated Ga{sub 2}O{sub 3} films were evaluated using X-ray diffraction, scanning electron microscopy, and spectrophotometric measurements. No secondary phase formation was observed in W-incorporated Ga{sub 2}O{sub 3} films. W-induced effects were significant on the structure and optical properties of Ga{sub 2}O{sub 3} films. The bandgap of Ga{sub 2}O{sub 3} films without W-incorporation was {approx}5 eV. Red-shift in the bandgap was noted with increasing W-concentration indicating the electronic structure changes in W-Ga{sub 2}O{sub 3} films. A functional relationship between W-concentration and optical property is discussed.

  1. Resistive switching phenomena of tungsten nitride thin films with excellent CMOS compatibility

    SciTech Connect (OSTI)

    Hong, Seok Man; Kim, Hee-Dong; An, Ho-Myoung; Kim, Tae Geun, E-mail: tgkim1@korea.ac.kr

    2013-12-15T23:59:59.000Z

    Graphical abstract: - Highlights: • The resistive switching characteristics of WN{sub x} thin films. • Excellent CMOS compatibility WN{sub x} films as a resistive switching material. • Resistive switching mechanism revealed trap-controlled space charge limited conduction. • Good endurance and retention properties over 10{sup 5} cycles, and 10{sup 5} s, respectively - Abstract: We report the resistive switching (RS) characteristics of tungsten nitride (WN{sub x}) thin films with excellent complementary metal-oxide-semiconductor (CMOS) compatibility. A Ti/WN{sub x}/Pt memory cell clearly shows bipolar RS behaviors at a low voltage of approximately ±2.2 V. The dominant conduction mechanisms at low and high resistance states were verified by Ohmic behavior and trap-controlled space-charge-limited conduction, respectively. A conducting filament model by a redox reaction explains the RS behavior in WN{sub x} films. We also demonstrate the memory characteristics during pulse operation, including a high endurance over >10{sup 5} cycles and a long retention time of >10{sup 5} s.

  2. Waltzing of a helium pair in tungsten: Migration barrier and trajectory revealed from first-principles

    SciTech Connect (OSTI)

    Niu, J. G. [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Department of Mechanical Engineering, Hebei University, Baoding 071000 (China); Zhan, Q., E-mail: qzhan@mater.ustb.edu.cn [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Geng, W. T., E-mail: geng@ustb.edu.cn [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Psi Quantum Materials LLC, Laiwu 271100 (China)

    2014-06-15T23:59:59.000Z

    Despite well documented first-principles theoretical determination of the low migration energy (0.06 eV) of a single He in tungsten, fully quantum mechanical calculations on the migration of a He pair still present a challenge due to the complexity of its trajectory. By identifying the six most stable configurations of the He pair in W and decomposing its motion into rotational, translational, and rotational-translational routines, we are able to determine its migration barrier and trajectory. Our density functional theory calculations demonstrate a He pair has three modes of motion: a close or open circular two-dimensional motion in (100) plane with an energy barrier of 0.30 eV, a snaking motion along [001] direction with a barrier of 0.30 eV, and a twisted-ladder motion along [010] direction with the two He swinging in the plane (100) and a barrier of 0.31 eV. The graceful associative movements of a He pair are related to the chemical-bonding-like He-He interaction being much stronger than its migration barrier in W. The excellent agreement with available experimental measurements (0.24–0.32 eV) on He migration makes our first-principles result a solid input to obtain accurate He-W interatomic potentials in molecular dynamics simulations.

  3. Radiative recombination data for tungsten ions: II. W{sup 47+}–W{sup 71+}

    SciTech Connect (OSTI)

    Trzhaskovskaya, M.B., E-mail: Trzhask@MT5605.spb.edu [Petersburg Nuclear Physics Institute, Gatchina 188300 (Russian Federation); Nikulin, V.K. [Ioffe Physical Technical Institute, St. Petersburg 194021 (Russian Federation)

    2014-07-15T23:59:59.000Z

    New radiative recombination and photoionization cross sections, radiative recombination rate coefficients, and radiated power loss rate coefficients are presented for 23 tungsten impurity ions in plasmas. We consider ions from W{sup 47+} to W{sup 71+} that are of importance to fusion studies for ITER and for experiments using electron beam ion traps. The calculations are fully relativistic and all significant multipoles of the radiative field are taken into account. The Dirac–Fock method is used to compute the electron wavefunctions. Radiative recombination rates and radiated power loss rates are found using the relativistic Maxwell–Jüttner distribution of the continuum electron velocity. The total radiative recombination cross sections are given in the electron energy range from 1 eV to ?80keV. Partial cross sections for ground and excited states are approximated by an analytical expression involving five fit parameters. Radiative recombination rates and radiated power loss rates are calculated in the temperature range from 10{sup 4}K to 10{sup 9}K. The total radiative recombination rates are approximated by another analytical expression with four fit parameters.

  4. Heat and mass transfer in the gas tungsten and gas metal arc welding processes

    SciTech Connect (OSTI)

    Watkins, A.D; Smartt, H.B.; Einerson, C.J.; Watkins, J.A.

    1990-01-01T23:59:59.000Z

    The heat transferred from an electrode negative, argon gas tungsten arc to an anode was measured for a wide range of conditions suitable for mechanized welding. The results are given as (1) the arc efficiency and (2) the anode heat and current input distributions for various anode materials over a range of current and voltage. The nominal arc is Gaussian, {approximately}4 mm in diameter, with {approximately}75{percent}heat transfer efficiency. Variations from these values are discussed in terms of the electrical and thermal energy transport mechanisms. Heat transferred to the workpiece (cathode) during direct current, electrode positive gas metal arc welding (GMAW) was measured for various parameters applicable to machine welding. The results are presented as a function of electrode speed for changing voltages and contact tip to workpiece distances. The total heat transfer efficiency was nominally 85{percent} for a 0.89 mm diameter steel electrode using an argon-2{percent} oxygen shielding gas; the nominal heat transfer efficiency of the droplet component was 40{percent}. The average droplet temperatures ranged from 2400 to 3100 K, depending on the process parameters. A new method of measuring the heat transferred from the arc to the workpiece, using a boiling liquid nitrogen calorimeter, has been developed that gives rapid, accurate values. 20 refs., 8 figs., 2 tabs.

  5. A calorimetric-based comparison of gas tungsten and plasma arc welding processes

    SciTech Connect (OSTI)

    Knorovsky, G.A.; Fuerschbach, P.W.

    1988-01-01T23:59:59.000Z

    Measurements of arc and melting efficiencies have been made for pulsed and continuous mode Gas Tungsten Arc Welding (GTAW) and Plasma Arc Welding (PAW) processes. Welds were made on 2.5 mm total thickness pure Ni and 304 Stainless Steel in a standing edge weld geometry at constant nominal machine output settings which varied average current with travel speed. Under continuous current conditions, the measured heat input remained approximately constant for the conditions examined (250-1250 mm/min), while melting efficiency increased dramatically (0-/approximately/0.4). Arc efficiencies were relatively constant, remaining in the range of /approximately/0.75-0.85 for GTAW and somewhat less for PAW. Values of melting efficiency for Ni were slightly less than those for 304 when compared at similar travel speeds, though both tended toward the same limit (/approximately/0.4). The PAW results were not appreciably higher than the GTAW. In addition to melting efficiency the centerline depth of penetration was also measured. In contrast to the GTAW results, which increased with speed at lower travel speeds and then plateaued at 0.8 mm, the PAW results increased monotonically with speed to a maximum of 1.0 mm. In conclusion, calorimetric measurements of nonconsumable arc welding processes have been found helpful in understanding conditions under which efficient arc welds with minimal heat inputs for a desired weld penetration can be made. 10 figs.

  6. Computational modeling of GTA (gas tungsten arc) welding with emphasis on surface tension effects

    SciTech Connect (OSTI)

    Zacharia, T.; David, S.A.

    1990-01-01T23:59:59.000Z

    A computational study of the convective heat transfer in the weld pool during gas tungsten arch (GTA) welding of Type 304 stainless steel is presented. The solution of the transport equations is based on a control volume approach which utilized directly, the integral form of the governing equations. The computational model considers buoyancy and electromagnetic and surface tension forces in the solution of convective heat transfer in the weld pool. In addition, the model treats the weld pool surface as a deformable free surface. The computational model includes weld metal vaporization and temperature dependent thermophysical properties. The results indicate that consideration of weld pool vaporization effects and temperature dependent thermophysical properties significantly influence the weld model predictions. Theoretical predictions of the weld pool surface temperature distributions and the cross-sectional weld pool size and shape wee compared with corresponding experimental measurements. Comparison of the theoretically predicted and the experimentally obtained surface temperature profiles indicated agreement with {plus minus} 8%. The predicted weld cross-section profiles were found to agree very well with actual weld cross-sections for the best theoretical models. 26 refs., 8 figs.

  7. Tungsten Cluster Migration on Nanoparticles: Minimum Energy Pathway and Migration Mechanism

    SciTech Connect (OSTI)

    Chen, Dong; Hu, Wangyu; Gao, Fei; Deng, Huiqiu; Sun, Lixian

    2011-03-02T23:59:59.000Z

    Transition state searches have been employed to investigate the migration mechanisms of W clusters on W nanoparticles, and to determine the corresponding migration energies for the possible migration paths of these clusters. The tungsten clusters containing up to four adatoms are found to prefer 2D-compact structures with relatively low binding energies. The effect of interface and vertex regions on the migration behavior of the clusters is significantly strong, as compared to that of nanoparticle size. The migration mechanisms are quite different when the clusters are located at the center of the nanoparticle and near the interface or vertex areas. Near the interfaces and vertex areas, the substrate atoms tend to participate in the migration processes of the clusters, and can join the adatoms to form a larger cluster or lead to the dissociation of a cluster via the exchange mechanism, which results in the adatom crossing the facets. The lowest energy paths are used to be determined the energy barriers for W cluster migrations (from 1- to 4-atoms) on the facets, edges and vertex regions. The calculated energy barriers for the trimers suggest that the concerted migration is more probable than the successive jumping of a single adatom in the clusters. In addition, it of interest to note that the dimer shearing is a dominant migration mechanism for the tetramer, but needs to overcome a relatively higher migration energy than other clusters.

  8. Crystal orientation effects on helium ion depth distributions and adatom formation processes in plasma-facing tungsten

    SciTech Connect (OSTI)

    Hammond, Karl D. [Department of Nuclear Engineering, University of Tennessee, Knoxville, Tennessee 37996–2300 (United States); Wirth, Brian D., E-mail: bdwirth@utk.edu [Department of Nuclear Engineering, University of Tennessee, Knoxville, Tennessee 37996–2300 (United States); P.O. Box 2008, MS-6003, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831–6003 (United States)

    2014-10-14T23:59:59.000Z

    We present atomistic simulations that show the effect of surface orientation on helium depth distributions and surface feature formation as a result of low-energy helium plasma exposure. We find a pronounced effect of surface orientation on the initial depth of implanted helium ions, as well as a difference in reflection and helium retention across different surface orientations. Our results indicate that single helium interstitials are sufficient to induce the formation of adatom/substitutional helium pairs under certain highly corrugated tungsten surfaces, such as (1 1 1)-orientations, leading to the formation of a relatively concentrated layer of immobile helium immediately below the surface. The energies involved for helium-induced adatom formation on (1 1 1) and (2 1 1) surfaces are exoergic for even a single adatom very close to the surface, while (0 0 1) and (0 1 1) surfaces require two or even three helium atoms in a cluster before a substitutional helium cluster and adatom will form with reasonable probability. This phenomenon results in much higher initial helium retention during helium plasma exposure to (1 1 1) and (2 1 1) tungsten surfaces than is observed for (0 0 1) or (0 1 1) surfaces and is much higher than can be attributed to differences in the initial depth distributions alone. The layer thus formed may serve as nucleation sites for further bubble formation and growth or as a source of material embrittlement or fatigue, which may have implications for the formation of tungsten “fuzz” in plasma-facing divertors for magnetic-confinement nuclear fusion reactors and/or the lifetime of such divertors.

  9. The elastic and piezoelectric properties of tungsten bronze ferroelectric crystals ,,Sr0.7Ba0.3...2NaNb5O15 and ,,Sr0.3Ba0.7...2NaNb5O15

    E-Print Network [OSTI]

    Cao, Wenwu

    The elastic and piezoelectric properties of tungsten bronze ferroelectric crystals ,,Sr0.7Ba0 and piezoelectric constants of tungsten bronze ferroelectric crystals Sr0.7Ba0.3 2NaNb5O15 SBNN70 and Sr0.3Ba0.7 2Na. INTRODUCTION Ferroelectric crystals with tungsten bronze structure are another attractive family beside

  10. Effects of Tungsten Oxide Addition on the Electrochemical Performance of Nanoscale Tantalum Oxide-Based Electrocatalysts for Proton Exchange Membrane PEM Fuel Cells

    SciTech Connect (OSTI)

    Oh, Tak Keun; Kim, Jin Yong; Shin, Yongsoon; Engelhard, Mark H.; Weil, K. Scott

    2011-08-01T23:59:59.000Z

    In the present study, the properties of a series of non-platinum based nanoscale tantalum oxide/tungsten oxide-carbon composite catalysts was investigated for potential use in catalyzing the oxygen reduction reaction (ORR) on the cathode side of a PEM fuel cell membrane electrode assembly. Electrochemical performance was measured using a half-cell test set up with a rotating disc electrode and compared with a commercial platinum-on-carbon (Pt/C) catalyst. Overall, all of the oxide-based composite catalysts exhibit high ORR on-set potentials, comparable to that of the baseline Pt/C catalyst. The addition of tungsten oxide as a dopant to tantalum oxide greatly improved mass specific current density. Maximum performance was achieved with a catalyst containing 32 mol% of tungsten oxide, which exhibited a mass specific current density ~8% that of the Pt/C catalyst at 0.6 V vs. the normal hydrogen electrode (NHE) and ~35% that of the Pt/C catalyst at 0.2 V vs. NHE. Results from X-ray photoelectron spectroscopy analysis indicated that the tungsten cations in the composite catalysts exist in the +6 oxidation state, while the tantalum displays an average valence of +5, suggesting that the addition of tungsten likely creates an oxygen excess in the tantalum oxide structure that influences its oxygen absorption kinetics. When the 32mol% tungsten doped catalyst loading on the working electrode was increased to five times that of the original loading (which was equivalent to that of the baseline Pt/C catalyst), the area specific current density improved four fold, achieving an area specific current density ~35% that of the Pt/C catalyst at 0.6 V vs. NHE.

  11. Microstructure evolution of Al/Mg butt joints welded by gas tungsten arc with Zn filler metal

    SciTech Connect (OSTI)

    Liu Fei; Zhang Zhaodong; Liu Liming, E-mail: liulm@dlut.edu.cn

    2012-07-15T23:59:59.000Z

    Based on the idea of alloying welding seam, Gas tungsten arc welding method with pure Zn filler metal was chosen to join Mg alloy and Al alloy. The microstructures, phases, element distribution and fracture morphology of welding seams were examined. The results indicate that there was a transitional zone in the width of 80-100 {mu}m between the Mg alloy substrate and fusion zone. The fusion zone was mainly composed of MgZn{sub 2}, Zn-based solid solution and Al-based solid solution. The welding seam presented distinct morphology in different location owning to the quite high cooling rate of the molten pool. The addition of Zn metal could prevent the formation of Mg-Al intermetallics and form the alloyed welding seam during welding. Therefore, the tensile strengths of joints have been significantly improved compared with those of gas tungsten arc welded joints without Zn metal added. Highlights: Black-Right-Pointing-Pointer Mg alloy AZ31B and Al alloy 6061 are welded successfully. Black-Right-Pointing-Pointer Zinc wire is employed as a filler metal to form the alloyed welding seam. Black-Right-Pointing-Pointer An alloyed welding seam is benefit for improving of the joint tensile strength.

  12. Fabrication of Tungsten-Rhenium Cladding materials via Spark Plasma Sintering for Ultra High Temperature Reactor Applications

    SciTech Connect (OSTI)

    Charit, Indrajit; Butt, Darryl; Frary, Megan; Carroll, Mark

    2012-11-05T23:59:59.000Z

    This research will develop an optimized, cost-effective method for producing high-purity tungsten-rhenium alloyed fuel clad forms that are crucial for the development of a very high-temperature nuclear reactor. The study will provide critical insight into the fundamental behavior (processing-microstructure- property correlations) of W-Re alloys made using this new fabrication process comprising high-energy ball milling (HEBM) and spark plasma sintering (SPS). A broader goal is to re-establish the U.S. lead in the research field of refractory alloys, such as W-Re systems, with potential applications in very high-temperature nuclear reactors. An essential long-term goal for nuclear power is to develop the capability of operating nuclear reactors at temperatures in excess of 1,000K. This capability has applications in space exploration and some special terrestrial uses where high temperatures are needed in certain chemical or reforming processes. Refractory alloys have been identified as being capable of withstanding temperatures in excess of 1,000K and are considered critical for the development of ultra hightemperature reactors. Tungsten alloys are known to possess extraordinary properties, such as excellent high-temperature capability, including the ability to resist leakage of fissile materials when used as a fuel clad. However, there are difficulties with the development of refractory alloys: 1) lack of basic experimental data on thermodynamics and mechanical and physical properties, and 2) challenges associated with processing these alloys.

  13. Measurement of Leakage Neutron Spectra for Tungsten with D-T Neutrons and Validation of Evaluated Nuclear Data

    E-Print Network [OSTI]

    S. Zhanga; Z. Chen; Y. Nie; R. Wada; X. Ruan; R. Han; X. Liu; W. Lin; J. Liu; F. Shi; P. Ren; G. Tian; F. Luo; J. Ren; J. Bao

    2014-11-20T23:59:59.000Z

    Integral neutronics experiments have been investigated at Institute of Modern Physics, Chinese Academy of Sciences (IMP, CAS) in order to validate evaluated nuclear data related to the design of Chinese Initiative Accelerator Driven Systems (CIADS). In present paper, the accuracy of evaluated nuclear data for Tungsten has been examined by comparing measured leakage neutron spectra with calculated ones. Leakage neutron spectra from the irradiation of D-T neutrons on Tungsten slab sample were experimentally measured at 60$^{\\circ}$ and 120$^{\\circ}$ by using a time-of-flight method. Theoretical calculations are carried out by Monte Carlo neutron transport code MCNP-4C with evaluated nuclear data of the ADS-2.0, ENDF/B-VII.0, ENDF/B-VII.1, JENDL-4.0 and CENDL-3.1 libraries. From the comparisons, it is found that the calculations with ADS-2.0 and ENDF/B-VII.1 give good agreements with the experiments in the whole energy regions at 60$^{\\circ}$, while a large discrepancy is observed at 120$^{\\circ}$ in the elastic scattering peak, caused by a slight difference in the oscillation pattern of the elastic angular distribution at angles larger than 20$^{\\circ}$. However, the calculated spectra using data from ENDF/B-VII.0, JENDL-4.0 and CENDL-3.1 libraries showed larger discrepancies with the measured ones, especially around 8.5-13.5 MeV. Further studies are presented for these disagreements.

  14. Preparation of hexagonal WO{sub 3} from hexagonal ammonium tungsten bronze for sensing NH{sub 3}

    SciTech Connect (OSTI)

    Szilagyi, Imre Miklos [Materials Structure and Modeling Research Group of the Hungarian Academy of Sciences, Budapest University of Technology and Economics, H-1111 Budapest, Szt. Gellert ter 4 (Hungary)], E-mail: imre.szilagyi@mail.bme.hu; Wang Lisheng; Gouma, Pelagia-Irene [Department of Materials Science and Engineering, 314 Old Engineering Building, SUNY, Stony Brook, NY 11794-2275 (United States); Balazsi, Csaba [Ceramics and Nanocomposites Laboratory, Research Institute for Technical Physics and Materials Science, H-1121 Budapest, Konkoly-Thege ut 29-33 (Hungary); Madarasz, Janos; Pokol, Gyoergy [Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, H-1111 Budapest, Szt. Gellert ter 4 (Hungary)

    2009-03-05T23:59:59.000Z

    Hexagonal tungsten oxide (h-WO{sub 3}) was prepared by annealing hexagonal ammonium tungsten bronze, (NH{sub 4}){sub 0.07}(NH{sub 3}){sub 0.04}(H{sub 2}O){sub 0.09}WO{sub 2.95}. The structure, composition and morphology of h-WO{sub 3} were studied by XRD, XPS, Raman, {sup 1}H MAS (magic angle spinning) NMR, scanning electron microscopy (SEM), and BET-N{sub 2} specific surface area measurement, while its thermal stability was investigated by in situ XRD. The h-WO{sub 3} sample was built up by 50-100 nm particles, had an average specific surface area of 8.3 m{sup 2}/g and was thermally stable up to 450 deg. C. Gas sensing tests showed that h-WO{sub 3} was sensitive to various levels (10-50 ppm) of NH{sub 3}, with the shortest response and recovery times (1.3 and 3.8 min, respectively) to 50 ppm NH{sub 3}. To this NH{sub 3} concentration, the sensor had significantly higher sensitivity than h-WO{sub 3} samples prepared by wet chemical methods.

  15. Protonation Studies of a Tungsten Dinitrogen Complex Supported by a Diphosphine Ligand Containing a Pendant Amine

    SciTech Connect (OSTI)

    Weiss, Charles J.; Egbert, Jonathan D.; Chen, Shentan; Helm, Monte L.; Bullock, R. Morris; Mock, Michael T.

    2014-05-12T23:59:59.000Z

    Treatment of trans-[W(N2)2(dppe)(PEtNMePEt)] (dppe = Ph2PCH2CH2PPh2; PEtNMePEt = Et2PCH2N(Me)CH2PEt2) with three equivalents of tetrafluoroboric acid (HBF4?Et2O) at -78 °C generated the seven-coordinate tungsten hydride trans-[W(N2)2(H)(dppe)(PEtNMePEt)][BF4]. Depending on the temperature of the reaction, protonation of a pendant amine is also observed, affording trans-[W(N2)2(H)(dppe)(PEtNMe(H)PEt)][BF4]2, with formation of the hydrazido complex, [W(NNH2)(dppe)(PEtNMe(H)PEt)][BF4]2, as a minor product. Similar product mixtures were obtained using triflic acid (HOTf). Upon acid addition to the carbonyl analogue, cis-[W(CO)2(dppe)(PEtNMePEt)], the seven-coordinate carbonyl-hydride complex, trans-[W(CO)2(H)(dppe)(PEtN(H)MePEt)][OTf]2 was generated. The mixed diphosphine complex without the pendant amine in the ligand backbone, trans-[W(N2)2(dppe)(depp)] (depp = Et2P(CH2)3PEt2), was synthesized and treated with HBF4?Et2O, selectively generating a hydrazido complex, [W(NNH2)(F)(dppe)(depp)][BF4]. Computational analysis was used to probe proton affinity of three sites of protonation, the metal, pendant amine, and N2 ligand in these complexes. Room temperature reactions with 100 equivalents of HOTf produced NH4+ from reduction of the N2 ligand (electrons come from W). The addition of 100 equivalents HOTf to trans-[W(N2)2(dppe)(PEtNMePEt)] afforded 0.88 ± 0.02 equivalents NH4+, while 0.36 ± 0.02 equivalents of NH4+was formed upon treatment of trans-[W(N2)2(dppe)(depp)], the complex without the pendant amine. This work was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy Office of Science, Office of Basic Energy Sciences. Computational resources were provided by the National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory. Pacific Northwest National Laboratory is operated by Battelle for DOE.

  16. Advance Digital Imaging Process for Tungsten Alloys Liquid-Phase Sintered in Microgravity W. B Goodwin, University of Tennessee, SURF 2009 Fellow

    E-Print Network [OSTI]

    Li, Mo

    Advance Digital Imaging Process for Tungsten Alloys Liquid-Phase Sintered in Microgravity W. B is to develop a digital image processing algorithm to rapidly detect and measure dihedral angles in binary. This geometric parameter greatly affects the liquid-phase sintering (LPS) process which is commonly used

  17. Crystalline mesoporous tungsten oxide nanoplate monoliths synthesized by directed soft template method for highly sensitive NO{sub 2} gas sensor applications

    SciTech Connect (OSTI)

    Hoa, Nguyen Duc, E-mail: ndhoa@itims.edu.vn [International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST) (Viet Nam); Duy, Nguyen Van [International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST) (Viet Nam)] [International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST) (Viet Nam); Hieu, Nguyen Van, E-mail: hieu@itims.edu.vn [International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST) (Viet Nam)

    2013-02-15T23:59:59.000Z

    Graphical abstract: Display Omitted Highlights: ? Mesoporous WO{sub 3} nanoplate monoliths were obtained by direct templating synthesis. ? Enable effective accession of the analytic molecules for the sensor applications. ? The WO{sub 3} sensor exhibited a high performance to NO{sub 2} gas at low temperature. -- Abstract: Controllable synthesis of nanostructured metal oxide semiconductors with nanocrystalline size, porous structure, and large specific surface area is one of the key issues for effective gas sensor applications. In this study, crystalline mesoporous tungsten oxide nanoplate-like monoliths with high specific surface areas were obtained through instant direct-templating synthesis for highly sensitive nitrogen dioxide (NO{sub 2}) sensor applications. The copolymer soft template was converted into a solid carbon framework by heat treatment in an inert gas prior to calcinations in air to sustain the mesoporous structure of tungsten oxide. The multidirectional mesoporous structures of tungsten oxide with small crystalline size, large specific surface area, and superior physical characteristics enabled the rapid and effective accession of analytic gas molecules. As a result, the sensor response was enhanced and the response and recovery times were reduced, in which the mesoporous tungsten oxide based gas sensor exhibited a superior response of 21,155% to 5 ppm NO{sub 2}. In addition, the developed sensor exhibited selective detection of low NO{sub 2} concentration in ammonia and ethanol at a low temperature of approximately 150 °C.

  18. Effect of tungsten addition on the toughness and hardness of Fe{sub 2}B in wear-resistant Fe-B-C cast alloy

    SciTech Connect (OSTI)

    Huang, Zhifu, E-mail: hzf@mail.xjtu.edu.cn; Xing, Jiandong; Lv, Liangliang

    2013-01-15T23:59:59.000Z

    The effects of tungsten additions of 0%, 1.12%, 2.04%, and 3.17% (in wt.%) on the morphology, fracture toughness and micro-hardness of Fe{sub 2}B in Fe-B-C cast alloy were investigated. The results indicate that, with the increase of tungsten addition, the morphology and distribution of Fe{sub 2}B have no change and a new W-containing phase, except the (Fe, W){sub 2}B with a certain tungsten solution, does not form, and that the fracture toughness of Fe{sub 2}B increases first and then decreases, while the hardness increases first and then has a little change. Compared with the fracture toughness (3.8 MPa{center_dot}m{sup 1/2}) of Fe{sub 2}B without tungsten addition, the toughness at 2.04 wt.% tungsten can be improved by about above 80% and achieves about 6.9 MPa{center_dot}m{sup 1/2}, and variation characteristics of hardness and toughness of Fe{sub 2}B were also testified by viewing the indentation marks and cracks on the Fe{sub 2}B, respectively. - Highlights: Black-Right-Pointing-Pointer Poor toughness of Fe2B decreases obviously the wear resistance of the alloy. Black-Right-Pointing-Pointer As W content increases, Fe2B's toughness increases first and then decreases. Black-Right-Pointing-Pointer As W content increases, Fe2B's hardness first increases and then has little change. Black-Right-Pointing-Pointer The toughness at 2.04 % W can be improved by above 80% more than that at 0% W.

  19. Tungsten carbide/porous carbon composite as superior support for platinum catalyst toward methanol electro-oxidation

    SciTech Connect (OSTI)

    Jiang, Liming [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); Fu, Honggang, E-mail: fuhg@vip.sina.com [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); Key Laboratory of Functional Inorganic Material Chemistry, Heilongjiang University, Harbin 150080 (China); Wang, Lei; Mu, Guang; Jiang, Baojiang; Zhou, Wei; Wang, Ruihong [Key Laboratory of Functional Inorganic Material Chemistry, Heilongjiang University, Harbin 150080 (China)

    2014-01-01T23:59:59.000Z

    Graphical abstract: The WC nanoparticles are well dispersed in the carbon matrix. The size of WC nanoparticles is about 30 nm. It can be concluded that tungsten carbide and carbon composite was successfully prepared by the present synthesis conditions. - Highlights: • The WC/PC composite with high specific surface area was prepared by a simple way. • The Pt/WC/PC catalyst has superior performance toward methanol electro-oxidation. • The current density for methanol electro-oxidation is as high as 595.93 A g{sup ?1} Pt. • The Pt/WC/PC catalyst shows better durability and stronger CO electro-oxidation. • The performance of Pt/WC/PC is superior to the commercial Pt/C (JM) catalyst. - Abstract: Tungsten carbide/porous carbon (WC/PC) composites have been successfully synthesized through a surfactant assisted evaporation-induced-assembly method, followed by a thermal treatment process. In particular, WC/PC-35-1000 composite with tungsten content of 35% synthesized at the carbonized temperature of 1000 °C, exhibited a specific surface area (S{sub BET}) of 457.92 m{sup 2} g{sup ?1}. After loading Pt nanoparticles (NPs), the obtained Pt/WC/PC-35-1000 catalyst exhibits the highest unit mass electroactivity (595.93 A g{sup ?1} Pt) toward methanol electro-oxidation, which is about 2.6 times as that of the commercial Pt/C (JM) catalyst. Furthermore, the Pt/WC/PC-35-1000 catalyst displays much stronger resistance to CO poisoning and better durability toward methanol electrooxidation compared with the commercial Pt/C (JM) catalyst. The high electrocatalytic activity, strong poison-resistivity and good stability of Pt/WC/PC-35-1000 catalyst are attributed to the porous structures and high specific surface area of WC/PC support could facilitate the rapid mass transportation. Moreover, synergistic effect between WC and Pt NPs is favorable to the higher catalytic performance.

  20. Light scattering from ,,K0.5Na0.5...0.2,,Sr0.75Ba0.25...0.9Nb2O6 with the tungsten bronze structure: An analogy with relaxor ferroelectrics

    E-Print Network [OSTI]

    Light scattering from ,,K0.5Na0.5...0.2,,Sr0.75Ba0.25...0.9Nb2O6 with the tungsten bronze structure a complex single crystal from the tungsten­bronze family, K0.5Na0.5 0.2 Sr0.75Ba0.25 0.9Nb2O6 doped with Cu2 photorefractive material.1 KNSBN originates from the tungsten­bronze family of ferroelectrics. KNSBN has two close