National Library of Energy BETA

Sample records for monazite sand ce

  1. PROCESSING OF MONAZITE SAND

    DOE Patents [OSTI]

    Calkins, G.D.; Bohlmann, E.G.

    1957-12-01

    A process for the recovery of thorium, uranium, and rare earths from monazite sands is presented. The sands are first digested and dissolved in concentrated NaOH, and the solution is then diluted causing precipitation of uranium, thorium and rare earth hydroxides. The precipitate is collected and dissolved in HCl, and the pH of this solution is adjusted to about 6, precipitating the hydroxides of thorium and uranium but leaving the rare earths in solution. The rare earths are then separated from the solution by precipitation at a still higher pH. The thorium and uranium containing precipitate is redissolved in HNO/sub 3/ and the two elements are separated by extraction into tributyl phosphate and back extraction with a weakly acidic solution to remove the thorium.

  2. METHOD OF PROCESSING MONAZITE SAND

    DOE Patents [OSTI]

    Welt, M.A.; Smutz, M.

    1958-08-26

    A process is described for recovering thorium, uranium, and rare earth values from monazite sand. The monazite sand is first digested with sulfuric acid and the resulting "monazite sulfate" solution is adjusted to a pH of between 0.4 and 3.0, and oxalate anions are added causing precipitation of the thorium and the rare earths as the oxalates. The oxalate precipitate is separated from the uranium containing supernatant solution, and is dried and calcined to the oxides. The thorium and rare earth oxides are then dissolved in nitric acid and the solution is contacted with tribntyl phosphate whereby an organic extract phase containing the cerium and thorium values is obtained, together with an aqueous raffinate containing the other rare earth values. The organic phase is then separated from the aqueous raffinate and the cerium and thorium are back extracted with an aqueous medium.

  3. METHOD OF PROCESSING MONAZITE SAND

    DOE Patents [OSTI]

    Calkins, G.D.

    1957-10-29

    A method is given for the pretreatment of monazite sand with sodium hydroxide. When momazite sand is reacted with sodium hydroxide, the thorium, uranium, and rare earths are converted to water-insoluble hydrous oxides; but in the case of uranium, the precipitate compound may at least partly consist of a slightly soluble uranate. According to the patent, monazite sand is treated with an excess of aqueous sodium hydroxide solution, and the insoluble compounds of thorium, uranium, and the rare earths are separated from the aqueous solution. This solution is then concentrated causing sodium phosphate to crystallize out. The crystals are removed from the remaining solution, and the solution is recycled for reaction with a mew supply of momazite sand.

  4. Phase transition and possible metallization in CeVO{sub 4} under pressure

    SciTech Connect (OSTI)

    Garg, Alka B.; Shanavas, K.V.; Wani, B.N.; Sharma, Surinder M.

    2013-07-15

    Phase stability of CeVO{sub 4} under pressure has been investigated using synchrotron based angle dispersive x-ray diffraction (ADXRD), electrical resistance and first principles calculations. The results indicate that the ambient zircon structure of the compound transforms to a low symmetry monoclinic monazite phase beyond 3.8 GPa with nearly 8.6% volume discontinuity. Beyond 11 GPa, the pattern could be fitted to a similar monazite structure which is about 12.7% denser and has a much larger monoclinic beta angle. On pressure release the first monoclinic phase is recovered. The electrical resistance data show a large drop in resistance with pressure indicating substantial narrowing down of the band gap. Electronic structure calculations support these observations and suggest possible pressure induced metallization in this material. - Pressure induced structural phase transition in CeVO{sub 4} as observed by x- ray diffraction (pressure vs. volume) and possible metallization in CeVO{sub 4} through electrical resistance and first principles electronic structure calculations. - Highlights: Structural and electrical behavior of CeVO{sub 4} under pressure studied using x-ray diffraction and electrical resistance measurements and first principles calculations. Two successive structural transitions confirmed by experiment and theory: zirconmonazite Imonazite II. Band gap collapse and possible metallization is indicated by electrical resistance measurements and electronic structure calculations under pressure. Novel observation of lower bulk modulus in the high pressure phase (both by experiment and calculations) explained through structural analysis.

  5. SAND78-1735

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

    printing a copy of any digitized SAND Report, you are required to update the markings to current standards. SAND 78-1735 Unlimited Release Printed February 1979 SOME VARIABILITY ...

  6. SAND2010-3950C

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

    is SAND2010-3950C. SAND2010-3950C Outline Outline * Performance Assessment methodology * Defining modeling objectives * Conceptual model development * Interface with site...

  7. Basaltic island sand provenance

    SciTech Connect (OSTI)

    Marsaglia, K.M. . Dept. of Geological Sciences)

    1992-01-01

    The Hawaiian Islands are an ideal location to study basaltic sand provenance in that they are a series of progressively older basaltic shield volcanoes with arid to humid microclimates. Sixty-two sand samples were collected from beaches on the islands of Hawaii, Maui, Oahu and Kauai and petrographically analyzed. The major sand components are calcareous bioclasts, volcanic lithic fragments, and monomineralic grains of dense minerals and plagioclase. Proportions of these components vary from island to island, with bioclastic end members being more prevalent on older islands exhibiting well-developed fringing reef systems and volcanic end members more prevalent on younger, volcanically active islands. Climatic variations across the island of Hawaii are reflected in the percentage of weathered detritus, which is greater on the wetter, northern side of the island. The groundmass of glassy, basaltic lithics is predominantly black tachylite, with lesser brown sideromelane; microlitic and lathwork textures are more common than holohyaline vitric textures. Other common basaltic volcanic lithic fragments are holocrystalline aggregates of silt-sized pyroxene or olivine, opaque minerals and plagioclase. Sands derived from alkalic lavas are texturally and compositionally indistinguishable from sands derived from tholeiitic lavas. Although Hawaiian basaltic sands overlap in composition with magmatic arc-derived sands in terms of their relative QFL, QmPK and LmLvLs percentages, they are dissimilar in that they lack felsic components and are more enriched in lathwork volcanic lithic fragments, holocrystalline volcanic lithic fragments, and dense minerals.

  8. SAND2008-2008

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

    SAND2008-2008 Unlimited Release Printed April 2008 Flatback Airfoil Wind Tunnel Experiment Jonathon P. Baker, C.P. "Case" van Dam, and Benson L. Gilbert Department of Mechanical ...

  9. SAND2009-2993

    Office of Scientific and Technical Information (OSTI)

    SAND2009-2993 Unlimited Release Printed May 2009 Radar Cross Section of Triangular Trihedral Reflector with Extended Bottom Plate Armin W. Doerry and Billy C. Brock Prepared by...

  10. Hydrocarbon rims on monazite in Permian-Triassic arenites, northern Perth Basin, Western Australia: Pointers to the former presence of oil

    SciTech Connect (OSTI)

    Rasmussen, B.; Glover, J.E. ); Alexander, R. )

    1989-02-01

    Black opaque hydrocarbon rims about 0.05 mm thick are preserved around detrital monazite grains in Permian-Triassic arenites of the norther Perth Basin, Western Australia. Chromatographic analysis indicates derivation from oil chemically like that elsewhere in the sequence, and the rims seem to be remnants of oil, which was largely flushed away. The hydrocarbon rims may have adhered to the monazite grains because of irradiation; they are not found on other grains. Monazite-rich heavy mineral bands are probably responsible for abnormally high radioactivity recorded locally by gamma-ray logs in wells penetrating the sandstones. A preliminary search has revealed similar rims around monazite in other Western Australian arenites ranging in age from Silurian to Cretaceous. Thin-section examination of heavy mineral concentrations may therefore be a useful, simple technique to indicate the former presence of hydrocarbons in dry arenites.

  11. CE Geothermal | Open Energy Information

    Open Energy Info (EERE)

    Geothermal Jump to: navigation, search Name: CE Geothermal Place: California Sector: Geothermal energy Product: CE Geothermal previously owned the assets of Western States...

  12. SAND92-7293

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

    CONTRACTOR REPORT SAND92-7293 Unlimited Release UC-235 Wind Effects on Convective Heat Loss From a Cavity Receiver for a Parabolic Concentrating Solar Collector Robert Y. Ma Department of Mechanical Engineering California State Polytechnic University Pomoma, CA 91768 Prepared by Sandia National Laboratories Albuquerque, New Mexico 87185 and Livermore, California 94550 for the United States Department of Energy under Contract DE-AC04-76DP00789 SANDIA NATIONAL LABORATORIES TECHNICAL LIBRARY

  13. SAND94-1057

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

    c.1 CONTRACTOR REPORT SAND94- 1057 Unlimited Release UC-276 The Interconnection of Photovoltaic Power Systems with the Utility Grid: An Overview for Utility Engineers Dr. Robert H. Wills, P.E. Principal Electrical Engineer Solar Design Associates, Inc. Architects and Engineers Harvard, MA Prepared by Sandia National Laboratories Albuquerque, New Mexico 87185 and Livermore, California 94550 for the United States Department of Energy under Contract DE-AC04-94AL85000 Printed June 1994 Approved for

  14. Compressive behavior of fine sand.

    SciTech Connect (OSTI)

    Martin, Bradley E.; Kabir, Md. E.; Song, Bo; Chen, Wayne

    2010-04-01

    The compressive mechanical response of fine sand is experimentally investigated. The strain rate, initial density, stress state, and moisture level are systematically varied. A Kolsky bar was modified to obtain uniaxial and triaxial compressive response at high strain rates. A controlled loading pulse allows the specimen to acquire stress equilibrium and constant strain-rates. The results show that the compressive response of the fine sand is not sensitive to strain rate under the loading conditions in this study, but significantly dependent on the moisture content, initial density and lateral confinement. Partially saturated sand is more compliant than dry sand. Similar trends were reported in the quasi-static regime for experiments conducted at comparable specimen conditions. The sand becomes stiffer as initial density and/or confinement pressure increases. The sand particle size become smaller after hydrostatic pressure and further smaller after dynamic axial loading.

  15. Sand Mountain Electric Coop | Open Energy Information

    Open Energy Info (EERE)

    Sand Mountain Electric Coop Jump to: navigation, search Name: Sand Mountain Electric Coop Place: Alabama Phone Number: Rainsville Area: 256---638---2153; Henagar Area:...

  16. SAND2012-8323P

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

    FUEL-ASSEMBLY SHAKER TEST PLAN Tests for Determining Loads on Used Nuclear Fuel under ... SAND2012-8323P Fuel Assembly Shaker Test ii September 2012 Sandia National ...

  17. SAND2010-3276C

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

    Albuquerque, NM, 2002. 9. Ong, C. H. and Tsai, S.W., "Design, Manufacture and Testing of a Bend-Twist D-Spar," SAND99-1324, Sandia National Laboratories, Albuquerque,...

  18. Tar Sands | Open Energy Information

    Open Energy Info (EERE)

    jobs are considered, an even larger job growth number is found. The net value of oil sands rose from 1.3 billion to 22.8 billion over that same period. This resulted in a...

  19. International Refrigeration: Order (2012-CE-1510) | Department...

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

    International Refrigeration: Order (2012-CE-1510) International Refrigeration: Order (2012-CE-1510) July 20, 2012 DOE ordered International Refrigeration Products to pay an 8,000 ...

  20. CE Solar | Open Energy Information

    Open Energy Info (EERE)

    Czech Republic Zip: 686 01 Product: Czech PV system integrator primarily building plants for Energy 21 in the Czech Republic. References: CE Solar1 This article is a stub....

  1. Treating tar sands formations with karsted zones

    DOE Patents [OSTI]

    Vinegar, Harold J.; Karanikas, John Michael

    2010-03-09

    Methods for treating a tar sands formation are described herein. The tar sands formation may have one or more karsted zones. Methods may include providing heat from one or more heaters to one or more karsted zones of the tar sands formation to mobilize fluids in the formation. At least some of the mobilized fluids may be produced from the formation.

  2. SAND 2004-0281P

    National Nuclear Security Administration (NNSA)

    SAND 2004-0281P March 2004 Issued by Sandia National Laboratories, operated for the United States Department of Energy by Sandia Corporation. Notice: This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for

  3. CRAD, NNSA - Conduct of Engineering (CE) | Department of Energy

    Office of Environmental Management (EM)

    Conduct of Engineering (CE) CRAD, NNSA - Conduct of Engineering (CE) CRAD for Conduct of Engineering (CE). Criteria Review and Approach Documents (CRADs) that can be used to...

  4. School Air: Proposed Penalty (2016-CE-43004) | Department of...

    Energy Savers [EERE]

    School Air: Proposed Penalty (2016-CE-43004) (15.74 KB) More Documents & Publications School Air: Order (2016-CE-43004) Temspec: Proposed Penalty (2016-CE-43002) Crane: Proposed ...

  5. Atosa: Proposed Penalty (2015-CE-42037) | Department of Energy

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

    Atosa: Proposed Penalty (2015-CE-42037) (15.43 KB) More Documents & Publications Atosa: Order (2015-CE-42037) Utility: Proposed Penalty (2016-CE-42007) Crane: Proposed Penalty ...

  6. RPI: Proposed Penalty (2015-CE-42065) | Department of Energy

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

    RPI: Proposed Penalty (2015-CE-42065) (16.14 KB) More Documents & Publications RPI: Order (2015-CE-42065) Utility: Proposed Penalty (2016-CE-42007) Crane: Proposed Penalty ...

  7. Almo: Order (2012-CE-1416) | Department of Energy

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

    PDF icon 2012-CE-1416AlmoOrder More Documents & Publications Almo: Proposed Penalty (2012-CE-1416) International Refrigeration: Order (2012-CE-1510) Commercial Display Systems: ...

  8. November 2015 | SAND2015-XXXX M

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

    | SAND2015-XXXX M Solar Basics for Homebuilders | Page 1 Solar photovoltaic (PV) energy systems are new in many residential real estate markets, and a growing number of ...

  9. Secure Fuels from Domestic Resources - Oil Shale and Tar Sands...

    Office of Environmental Management (EM)

    Secure Fuels from Domestic Resources - Oil Shale and Tar Sands Secure Fuels from Domestic Resources - Oil Shale and Tar Sands Profiles of Companies Engaged in Domestic Oil Shale ...

  10. CE: Proposed Penalty (2013-SE-1429)

    Broader source: Energy.gov [DOE]

    DOE alleged in a Notice of Proposed Civil Penalty that CE North America, LLC, privately labeled and distributed noncompliant freezers in the U.S.

  11. CE: Compromise Agreement (2013-SE-1429)

    Broader source: Energy.gov [DOE]

    DOE and CE North America entered into a Compromise Agreement to resolve a case involving the distribution in commerce of noncompliant freezers.

  12. Photoelectron spectra of CeO{sup −} and Ce(OH){sub 2}{sup −}

    SciTech Connect (OSTI)

    Ray, Manisha; Felton, Jeremy A.; Kafader, Jared O.; Topolski, Josey E.; Jarrold, Caroline Chick

    2015-02-14

    The photoelectron spectrum of CeO{sup −} exhibits what appears to be a single predominant electronic transition over an energy range in which numerous close-lying electronic states of CeO neutral are well known. The photoelectron spectrum of Ce(OH){sub 2}{sup −}, a molecule in which the Ce atom shares the same formal oxidation state as the Ce atom in CeO{sup −}, also exhibits what appears to be a single transition. From the spectra, the adiabatic electron affinities of CeO and Ce(OH){sub 2} are determined to be 0.936 ± 0.007 eV and 0.69 ± 0.03 eV, respectively. From the electron affinity of CeO, the CeO{sup −} bond dissociation energy was determined to be 7.7 eV, 0.5 eV lower than the neutral bond dissociation energy. The ground state orbital occupancies of both CeO{sup −} and Ce(OH){sub 2}{sup −} are calculated to have 4f 6s{sup 2} Ce{sup +} superconfigurations, with open-shell states having 4f5d6s superconfiguration predicted to be over 1 eV higher in energy. Low-intensity transitions observed at higher electron binding energies in the spectrum of CeO{sup −} are tentatively assigned to the {sup 1}Σ{sup +} (Ω = 0) state of CeO with the Ce{sup +2}⍰6s{sup 2} superconfiguration.

  13. Oil Sands Feedstocks | Department of Energy

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

    Sands Feedstocks Oil Sands Feedstocks Presentation given at DEER 2006, August 20-24, 2006, Detroit, Michigan. Sponsored by the U.S. DOE's EERE FreedomCar and Fuel Partnership and 21st Century Truck Programs. 2006_deer_fairbridge.pdf (1.94 MB) More Documents & Publications Energy Independence for North America - Transition to the Hydrogen Economy Emissions from Heavy-Duty Diesel Engine with EGR using Oil Sands Derived Fuels The Influence of Molecular Structure of Distillate Fuels on HFRR

  14. Microsoft Word - SAND2011-1094.docx

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

    ... The d States the best e 3 SAND2011-1094 Unlimited Release Printed March 2011 Wind Turbine ... 31. Emerging NDE Technology and Challenges at the beginning of the 3rd Millennium. ...

  15. SAND78-0962 VOL 3

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

    .( SAND78-0962 ECONOMIC ANALYSIS OF DARRIEUS VERTICAL-AXIS WIND TURBINE SYSTEMS FOR THE GENERATION OF UTILITY GRID ELECTRICAL POWER VOLUME III: POINT DESIGNS Robert D. Grover Emil...

  16. SAND78-0962 VOL 2

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

    SAND78-0962 ECONOMIC ANALYSIS OF DARRIEUS VERTICAL AXIS WIND TURBINE SYSTEMS FOR THE GENERATION OF UTILITY GRID ELECTRICAL POWER VOLUME II - THE ECONOMIC OPTIMIZATION MODEL W. N....

  17. SANDIA REPORT SAND93-1076

    Office of Scientific and Technical Information (OSTI)

    SAND93-1076 * uqo UnlimitedRelease 1 Pdnted November 1993 :ii l Standard Testing Procedures for Optical Fiber and Unshielded Twisted Pair at Sandia National Laboratories R. L. ...

  18. Treating tar sands formations with dolomite

    DOE Patents [OSTI]

    Vinegar, Harold J.; Karanikas, John Michael

    2010-06-08

    Methods for treating a tar sands formation are described herein. The tar sands formation may include dolomite and hydrocarbons. Methods may include providing heat at less than the decomposition temperature of dolomite from one or more heaters to at least a portion of the formation. At least some of the hydrocarbon fluids are mobilized in the formation. At least some of the hydrocarbon fluids may be produced from the formation.

  19. California Ethanol Power CE P | Open Energy Information

    Open Energy Info (EERE)

    Power CE P Jump to: navigation, search Name: California Ethanol & Power (CE+P) Place: Florida Product: US ethanol project developer. References: California Ethanol & Power...

  20. Palmetto Clean Energy (PaCE) Program

    Office of Energy Efficiency and Renewable Energy (EERE)

    PaCE funding comes from the customers of participating utilities who voluntarily choose to support the program through an additional charge on their monthly utility bills. Of the $4, $3.50 goes t...

  1. CeCap LLP | Open Energy Information

    Open Energy Info (EERE)

    Name: CeCap LLP Place: London, United Kingdom Zip: W1S 2LQ Product: London-based investment boutique which provides investment advice to, and invests in, small to mediun size...

  2. Creating fluid injectivity in tar sands formations

    DOE Patents [OSTI]

    Stegemeier, George Leo; Beer, Gary Lee; Zhang, Etuan

    2012-06-05

    Methods for treating a tar sands formation are described herein. Methods for treating a tar sands may include heating a portion of a hydrocarbon layer in the formation from one or more heaters located in the portion. The heat may be controlled to increase the permeability of at least part of the portion to create an injection zone in the portion with an average permeability sufficient to allow injection of a fluid through the injection zone. A drive fluid and/or an oxidizing fluid may be provided into the injection zone. At least some hydrocarbons including mobilized hydrocarbons are produced from the portion.

  3. Creating fluid injectivity in tar sands formations

    DOE Patents [OSTI]

    Stegemeier, George Leo; Beer, Gary Lee; Zhang, Etuan

    2010-06-08

    Methods for treating a tar sands formation are described herein. Methods for treating a tar sands may include heating a portion of a hydrocarbon layer in the formation from one or more heaters located in the portion. The heat may be controlled to increase the permeability of at least part of the portion to create an injection zone in the portion with an average permeability sufficient to allow injection of a fluid through the injection zone. A drive fluid and/or an oxidizing fluid may be provided into the injection zone. At least some hydrocarbons are produced from the portion.

  4. Future of heavy crude and tar sands

    SciTech Connect (OSTI)

    Meyer, R.F.; Steele, C.T.

    1981-01-01

    The 106 papers which were presented at the First International Conference on the Future of Heavy Crude and Tar Sands, held in Edmonton, Alberta are incorporated in this volume. They are grouped under the following sections: (1) role of heavy crude oils and tar sands in world energy; (2) major known occurrences; (3) chemistry and geochemistry; (4) geology; (5) resource evaluation techniques; (6) production research and pilot projects; (7) current production; (8) upgrading and refining; (9) transportation; (10) environmental research; (11) economics; (12) technological problems; (13) institutional factors; and (14) bibliography. All papers have been abstracted and indexed. (ATT)

  5. Wind profiles on the stoss slope of sand dunes: Implications for eolian sand transport

    SciTech Connect (OSTI)

    Frank, A.; Kocurek, G. (Univ. of Texas, Austin, TX (United States). Dept. of Geological Sciences)

    1993-04-01

    Starting with the work of R.A. Bagnold it has been recognized that the shear stress exerted by the wind on sand grains is the driving force for eolian sand transport. Calculation of accurate rates of sand transport is essential for prediction of migration rates of sand dunes in modern environments as well as reconstructing paleoclimates (wind speed and direction) from eolian deposits. Because a sand dune is a streamlined obstacle in the path of the wind, continuity necessitates that the flow field is compressed over the windward side of a dune and shear stress should progressively increase up the slope as the flow accelerates. However, airflow measurements over 14 dunes (at White Sands, New Mexico; Algodones, CA; and Padre Island, TX) show that compression of the flow field occurs very close to the surface and as a consequence, the overlying flow actually shows an overall decrease in shear stress up the slope. Measurements commonly collected in the overlying zone are not representative of the near-surface, sand-driving wind. Furthermore, near-surface compression of the flow field implies that a pressure gradient exists that would render the current transport models inappropriate for sloping surfaces that dominate natural sandy desert terrains.

  6. File:OilSands.pdf | Open Energy Information

    Open Energy Info (EERE)

    OilSands.pdf Jump to: navigation, search File File history File usage File:OilSands.pdf Size of this preview: 463 599 pixels. Other resolution: 464 600 pixels. Go to page 1 2...

  7. Well completion process for formations with unconsolidated sands

    DOE Patents [OSTI]

    Davies, David K.; Mondragon, III, Julius J.; Hara, Philip Scott

    2003-04-29

    A method for consolidating sand around a well, involving injecting hot water or steam through well casing perforations in to create a cement-like area around the perforation of sufficient rigidity to prevent sand from flowing into and obstructing the well. The cement area has several wormholes that provide fluid passageways between the well and the formation, while still inhibiting sand inflow.

  8. Hybridized Nature of Pseudogap in Kondo Insulators CeRhSb and CeRhAs

    SciTech Connect (OSTI)

    Kumigashira, H.; Takahashi, T.; Yoshii, S.; Kasaya, M.

    2001-08-06

    We studied the electronic structure of Kondo insulators CeRhSb and CeRhAs using high-resolution photoemission spectroscopy. We found that the 4f -derived density of states shows a depletion (pseudogap) at E{sub F} in contrast to metallic Kondo materials. It was found that the size of the f pseudogap is smaller than that of conduction electrons (c pseudogap) while both scale well with the Kondo temperature. The present results indicate that the hybridization between 4f and conduction electrons near E{sub F} is essential for the Kondo gap in the Ce-based compounds.

  9. SAND76-0260 Unlimited Release

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

    SAND76-0260 Unlimited Release Printed July 1976 . POWER SUPPLIES FOR SPACE SYSTEMS QUALITY ASSURANCE BY SANDIA LABORATORIES Robert L. Hannigan Robert R. Harnar Electronic and Electrical Devices Division 951 2 Sandia Laboratories Albuquerque, NM 87115 AB STRAC T This report summarizes the Sandia Laboratories participation in Quality Assurance programs for Radioisotopic Thermoelectric Generators which have been used i n space systems over the past 10 years. Basic elements of this QA program a r e

  10. EA-1581: Sand Hills Wind Project, Wyoming

    Broader source: Energy.gov [DOE]

    The Bureau of Land Management, with DOE’s Western Area Power Administration as a cooperating agency, was preparing this EA to evaluate the environmental impacts of a proposal to construct, operate, and maintain the Sand Hills Wind Energy Facility on private and federal lands in Albany County, Wyoming. If the proposed action had been implemented, Western would have interconnected the proposed facility to an existing transmission line. This project has been canceled.

  11. Solvent extraction of Southern US tar sands

    SciTech Connect (OSTI)

    Penney, W.R.

    1990-01-01

    The Department of Chemical Engineering at the University of Arkansas, in association with Diversified Petroleum Recovery, Inc. (DPR) of Little Rock, Arkansas, has been developing a solvent extraction process for the recovery of bitumen from tar sands for the past five years. The unique feature of the process is that the bitumen is recovered from the solvent by contacting with a co-solvent, which causes the bitumen to precipitate. The overall purpose of this project is to study both the technical and economic feasibility of applying this technology for recovery of bitumen from tar sands by (1) investigating the socioeconmic factors which affect (a) plant siting and (b) the market value of recovered bitumen; (2) operating a process demonstration unit at the rate of 1 lb/hr recovered bitumen while producing clean sand and recyclable solvents; and (3) determine the economic conditions which will make a bitumen recovery project economical. DPR has analyzed the historical trends of domestic production, consumption, discoveries and reserves of crude oil. They have started an investigation of the volatility in the price of crude oil and of gasoline prices and of the differential between gasoline and crude oil. DPR continues to analyze the geographical movement and demand for asphalt products. Utah does not appear economically attractive as a site for a bitumen from tar sands asphalt plant. Oklahoma sites are now being studied. This report also contains the quarterly progress report from a University of Nevada study to determine bitumen composition, oxygen uptake rates, and viscosities of Alabama and Utah bitumens. Both reports have been indexed separately for inclusion on the data base.

  12. CONTENTS Gas Hydrate-Bearing Sand

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

    CONTENTS Gas Hydrate-Bearing Sand Reservoir Systems in the Offshore of India: Results of the India National Gas Hydrate Program Expedition 02 ..............1 The Potential for Abiotic Methane in Arctic Gas Hydrates .................9 Coupled Thermo-Hydro-Chemo- Mechanical (THCM) Models for Hydrate-Bearing Sediments ....13 Emerging Issues in the Development of Geologic Models for Gas Hydrate Numerical Simulation ................19 Announcements ...................... 23 * DOE/NETL FY2016 Methane

  13. Guide to preparing SAND reports. Revised

    SciTech Connect (OSTI)

    Locke, T.K.

    1996-04-01

    This guide contains basic information needed to produce a SAND report. Its guidelines reflect DOE regulation and Sandia policy. The guide includes basic writing instructions in an annotated sample report; guidance for organization, format, and layout of reports produced by line organizations; and information about conference papers, journal articles, and brochures. The appendixes contain sections on Sandia`s preferred usage, equations, references, copyrights and permissions, and publishing terms.

  14. Goodman Manufacturing: Order (2012-CE-1509) | Department of Energy

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

    2-CE-1509) Goodman Manufacturing: Order (2012-CE-1509) August 7, 2012 DOE ordered Goodman Manufacturing Company L.P. to pay an 8,000 civil penalty after finding Goodman...

  15. Spin reorientation and Ce-Mn coupling in antiferromagnetic oxypnictide CeMnAsO

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

    Zhang, Qiang; Tian, Wei; Peterson, Spencer G.; Dennis, Kevin W.; Vaknin, David

    2015-02-18

    Structure and magnetic properties of high-quality polycrystlline CeMnAsO, a parent compound of the “1111”-type oxypnictides, have been investigated using neutron powder diffraction and magnetization measurements. We find that CeMnAsO undergoes a C-type antiferromagnetic order with Mn2+(S = 5/2) moments pointing along the c axis below a relatively high Néel temperature of TN = 347(1) K. Below TSR = 35 K, two simultaneous transitions occur where the Mn moments reorient from the c axis to the ab plane preserving the C-type magnetic order, and Ce moments undergo long-range AFM ordering with antiparallel moments pointing in the ab plane. Another transition tomore » a noncollinear magnetic structure occurs below 7 K. The ordered moments of Mn and Ce at 2 K are 3.32(4) μB and 0.81(4)μB, respectively. We find that CeMnAsO primarily falls into the category of a local-moment antiferromagnetic insulator in which the nearest-neighbor interaction (J1) is dominant with J2 < J1/2 in the context of J1 – J2 – Jc model. The spin reorientation transition driven by the coupling between Ce and the transition metal seems to be common to Mn, Fe, and Cr ions, but not to Co and Ni ions in the isostructural oxypnictides. As a result, a schematic illustration of magnetic structures in Mn and Ce sublattices in CeMnAsO is presented.« less

  16. RPI: Order (2015-CE-42065) | Department of Energy

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

    Order (2015-CE-42065) RPI: Order (2015-CE-42065) November 6, 2015 DOE ordered RPI Industries, Inc. to pay a $8,000 civil penalty after finding RPI had failed to certify that certain models of commercial refrigeration equipment comply with the applicable energy conservation standards. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and RPI. RPI: Order (2015-CE-42065) (21.12 KB) More Documents & Publications RPI: Proposed Penalty (2015-CE-42065) Wolverine

  17. Utility: Order (2016-CE-42007) | Department of Energy

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

    CE-42007) Utility: Order (2016-CE-42007) January 5, 2016 DOE ordered Utility Refrigerator to pay a $8,000 civil penalty after finding Utility had failed to certify that certain models of commercial refrigerator equipment comply with the applicable energy conservation standards. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Utility. Utility: Order (2016-CE-42007) (22.13 KB) More Documents & Publications Utility: Proposed Penalty (2016-CE-42007) Bu

  18. Policy Analysis of the Canadian Oil Sands Experience

    SciTech Connect (OSTI)

    None, None

    2013-09-01

    For those who support U.S. oil sands development, the Canadian oil sands industry is often identified as a model the U.S. might emulate, yielding financial and energy security benefits. For opponents of domestic oil sands development, the Canadian oil sands experience illustrates the risks that opponents of development believe should deter domestic policymakers from incenting U.S. oil sands development. This report does not seek to evaluate the particular underpinnings of either side of this policy argument, but rather attempts to delve into the question of whether the Canadian experience has relevance as a foundational model for U.S. oil sands development. More specifically, this report seeks to assess whether and how the Canadian oil sands experience might be predictive or instructive in the context of fashioning a framework for a U.S. oil sands industry. In evaluating the implications of these underpinnings for a prospective U.S. oil sands industry, this report concentrates on prospective development of the oil sands deposits found in Utah.

  19. Eolian cover sands: a sedimentologic model and paleoenvironmental implications

    SciTech Connect (OSTI)

    Lea, P.D.

    1985-01-01

    In periglacial areas, accumulations of eolian sand commonly form low-relief blankets without well-developed dunes. Internally, these sandsheet deposits exhibit subhorizontal lamination rather than high-angle cross-bedding. Such cover sands of late-Pleistocene age mantle extensive areas in northern Europe, but have been reported more rarely from North America. The processes by which cover sands, as opposed to dunes, accumulate have not yet been determined conclusively. Wind ripples and sand dunes do not form a continuum; flow separation and avalanching and negligible in the former and vital in the latter. Accretion of a sand patch into a mound sufficient to cause flow separation and dune growth requires a consistently available supply of loose sand. In cover-sand areas, sand may be immobilized prior to dune development by several factors: (1) a sparse vegetation cover, (2) moist ground conditions, (3) snow cover, and (4) a shallow permafrost table and/or an ice-cemented active layer. Detailed sedimentologic studies may allow discrimination among these various controls. The importance of the individual controlling factors can vary seasonally in a given deposit, as well as between deposits in different paleogeographic settings. However, all factors imply more mesic conditions than those associated with many dune deposits. The association of cover sands with paraboloid dunes is also consistent with somewhat moist conditions. The relatively mesic nature of cover sands controls their Pleistocene distribution; they become decreasingly important relative to dunes in maritime-to-continental transects across Alaska and northern Europe.

  20. Oil shale, tar sands, and related materials

    SciTech Connect (OSTI)

    Stauffer, H.C.

    1981-01-01

    This sixteen-chapter book focuses on the many problems and the new methodology associated with the commercialization of the oil shale and tar sand industry. Topics discussed include: an overview of the Department of Energy's oil shale R, D, and D program; computer simulation of explosive fracture of oil shale; fracturing of oil shale by treatment with liquid sulfur dioxide; chemistry of shale oil cracking; hydrogen sulfide evolution from Colorado oil shale; a possible mechanism of alkene/alkane production in oil shale retorting; oil shale retorting kinetics; kinetics of oil shale char gasification; a comparison of asphaltenes from naturally occurring shale bitumen and retorted shale oils: the influence of temperature on asphaltene structure; beneficiation of Green River oil shale by density methods; beneficiation of Green River oil shale pelletization; shell pellet heat exchange retorting: the SPHER energy-efficient process for retorting oil shale; retorted oil shale disposal research; an investigation into the potential economics of large-scale shale oil production; commercial scale refining of Paraho crude shale oil into military specification fuels; relation between fuel properties and chemical composition; chemical characterization/physical properties of US Navy shale-II fuels; relation between fuel properties and chemical composition: stability of oil shale-derived jet fuel; pyrolysis of shale oil residual fractions; synfuel stability: degradation mechanisms and actual findings; the chemistry of shale oil and its refined products; the reactivity of Cold Lake asphaltenes; influence of thermal processing on the properties of Cold Lake asphaltenes: the effect of distillation; thermal recovery of oil from tar sands by an energy-efficient process; and hydropyrolysis: the potential for primary upgrading of tar sand bitumen.

  1. Heating tar sands formations while controlling pressure

    DOE Patents [OSTI]

    Stegemeier, George Leo [Houston, TX; Beer, Gary Lee [Houston, TX; Zhang, Etuan [Houston, TX

    2010-01-12

    Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. A pressure in the majority of the section may be maintained below a fracture pressure of the formation. The pressure in the majority of the section may be reduced to a selected pressure after the average temperature reaches a temperature that is above 240.degree. C. and is at or below pyrolysis temperatures of hydrocarbons in the section. At least some hydrocarbon fluids may be produced from the formation.

  2. Heating tar sands formations to visbreaking temperatures

    DOE Patents [OSTI]

    Karanikas, John Michael; Colmenares, Tulio Rafael; Zhang, Etuan; Marino, Marian; Roes, Augustinus Wilhelmus Maria; Ryan, Robert Charles; Beer, Gary Lee; Dombrowski, Robert James; Jaiswal, Namit

    2009-12-22

    Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. The heat may be controlled so that at least a majority of the section reaches an average temperature of between 200.degree. C. and 240.degree. C., which results in visbreaking of at least some hydrocarbons in the section. At least some visbroken hydrocarbon fluids may be produced from the formation.

  3. SAND2011-9306 Unlimited Release

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

    SAND2011-9306 Unlimited Release Printed November 2011 Reference Model 2: "Rev 0" Rotor Design Matt Barone, Todd Griffith, and Jonathan Berg Sandia National Laboratories P.O. Box 5800 Albuquerque, New Mexico 87185-1124 Abstract The preliminary design for a three-bladed cross-flow rotor for a reference marine hydrokinetic turbine is presented. A rotor performance design code is described, along with modifications to the code to allow prediction of blade support strut drag as well as

  4. Testing the Delaware sand filter's effectiveness for treating stormwater runoff

    SciTech Connect (OSTI)

    Leszczynska, D.; Dzurik, A.

    1998-07-01

    The use of the Delaware Sand Filter for treatment of ultra-urban stormwater is investigated for Florida applications. An experimental Delaware filter is designed in conjunction with a typical sand filter as part of a street improvement project in Tallahassee, Florida. The design allows for testing of different filter media in an attempt to determine the suitability of the Delaware Sand Filter in hot climates with numerous heavy rainfall episodes.

  5. Oil Shale and Oil Sands Development Robert Keiter; John Ruple...

    Office of Scientific and Technical Information (OSTI)

    Conjunctive Surface and Groundwater Management in Utah: Implications for Oil Shale and Oil Sands Development Robert Keiter; John Ruple; Heather Tanana; Rebecca Holt 29 ENERGY...

  6. RFC Sand Creek Development LLC | Open Energy Information

    Open Energy Info (EERE)

    Colorado Zip: 80014 Product: Subsidiary of Republic Financial Corporation set up to invest in Sand Creek Energy LLC, a planned gas to liquid facility. Coordinates: 39.325162,...

  7. Sand Springs, Oklahoma: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Sand Springs, Oklahoma: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 36.1398102, -96.108891 Show Map Loading map... "minzoom":false,"mapping...

  8. Dynamic Behavior of Sand: Annual Report FY 11 (Technical Report...

    Office of Scientific and Technical Information (OSTI)

    ... Sponsoring Org: USDOE Country of Publication: United States Language: English Subject: 71 ... SAND; SENSITIVITY; SIMULATION; TARGETS; TESTING; WEAPONS Word Cloud More Like This Full ...

  9. Sand Dunes Hot Spring Aquaculture Low Temperature Geothermal...

    Open Energy Info (EERE)

    Dunes Hot Spring Aquaculture Low Temperature Geothermal Facility Jump to: navigation, search Name Sand Dunes Hot Spring Aquaculture Low Temperature Geothermal Facility Facility...

  10. Reuse of waste cutting sand at Lawrence Livermore National Laboratory

    SciTech Connect (OSTI)

    Mathews, S., LLNL

    1998-02-25

    Lawrence Livermore National Laboratory (LLNL) examined the waste stream from a water jet cutting operation, to evaluate the possible reuse of waste garnet sand. The sand is a cutting agent used to shape a variety of materials, including metals. Nearly 70,000 pounds of waste sand is generated annually by the cutting operation. The Environmental Protection Department evaluated two potential reuses for the spent garnet sand: backfill in utility trenches; and as a concrete constituent. In both applications, garnet waste would replace the sand formerly purchases by LLNL for these purposes. Findings supported the reuse of waste garnet sand in concrete, but disqualified its proposed application as trench backfill. Waste sand stabilized in ac concrete matrix appeared to present no metals-leaching hazard; however, unconsolidated sand in trenches could potentially leach metals in concentrations high enough to threaten ground water quality. A technical report submitted to the San Francisco Bay Regional Water Quality Control Board was reviewed and accepted by that body. Reuse of waste garnet cutting sand as a constituent in concrete poured to form walkways and patios at LLNL was approved.

  11. Montana Sand and Gravel Operations General Permit - Example Authorizat...

    Open Energy Info (EERE)

    OpenEI Reference LibraryAdd to library PermittingRegulatory Guidance - Supplemental Material: Montana Sand and Gravel Operations General Permit - Example AuthorizationPermitting...

  12. White Sands, New Mexico: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Sands, New Mexico: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 32.38319, -106.481499 Show Map Loading map... "minzoom":false,"mappingservic...

  13. TESTING OF TMR SAND MANTIS FINAL REPORT

    SciTech Connect (OSTI)

    Krementz, D; William Daugherty, W

    2007-06-12

    Screening tests of Sand Mantis candidate materials selected for erosion resistance have been completed. The results of this testing identified that over a relatively short period of operation (<1 hour), measurable erosion will occur in each of the candidate zoom tube materials given equal operating exposure. Additionally, this testing has shown that erosion of the rubber discharge hose directly downstream of the vehicle could be expected to limit the service life of the discharge hose. On the basis of these test results, SRNL recommends the following; {lg_bullet} redesign of critical system components (e.g., zoom tube, discharge hose) should be conducted to improve system characteristics relative to erosion and capitalize on the results of this testing, {lg_bullet} continued efforts to deploy the Sand Mantis should include testing to better define and optimize operating parameters, and gain an understanding of system dynamics, {lg_bullet} discontinue wear testing with the selected materials pending redesign of critical system components (1st recommendation) and inclusion of other candidate materials. The final selection of additional candidate materials should be made following design changes, but might include a Stellite alloy or zirconia.

  14. Water Dissociation on CeO2(100) and CeO2(111) Thin Films

    SciTech Connect (OSTI)

    Mullins, David R; Albrecht, Peter M; Chen, Tsung-Liang; Calaza, Florencia C; Biegalski, Micahel; Christen, Hans; Overbury, Steven {Steve} H

    2012-01-01

    This study reports and compares the adsorption and dissociation of water on oxidized and reduced CeO{sub 2}(100) and CeO{sub 2}(111) thin films. Water adsorbs dissociatively on both surfaces. On fully oxidized CeO{sub 2}(100) the resulting surface hydroxyls are relatively stable and recombine and desorb as water over a range from 200 to 600 K. The hydroxyls are much less stable on oxidized CeO{sub 2}(111), recombining and desorbing between 200 and 300 K. Water produces 30% more hydroxyls on reduced CeO{sub 1.7}(100) than on oxidized CeO{sub 2}(100). The hydroxyl concentration increases by 160% on reduced CeO{sub 1.7}(111) compared to oxidized CeO{sub 2}(111). On reduced CeO{sub 1.7}(100) most of the hydroxyls still recombine and desorb as water between 200 and 750 K. Most of the hydroxyls on reduced CeO{sub 1.7}(111) react to produce H{sub 2} at 560 K, leaving O on the surface. A relatively small amount of H{sub 2} is produced from reduced CeO{sub 1.7}(100) between 450 and 730 K. The differences in the adsorption and reaction of water on CeO{sub X}(100) and CeO{sub X}(111) are attributed to different adsorption sites on the two surfaces. The adsorption site on CeO{sub 2}(100) is a bridging site between two Ce cations. This adsorption site does not change when the ceria is reduced. The adsorption site on CeO{sub 2}(111) is atop a single Ce cation, and the proton is transferred to a surface O in a site between three Ce cations. When the CeO{sub X}(111) is reduced, vacancy sites are produced which allows the water to adsorb and dissociate on the 3-fold Ce cation sites.

  15. Role of Ce4+ in the scintillation mechanism of codoped Gd3Ga3Al2O12:Ce

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

    Wu, Yuntao; Meng, Fang; Li, Qi; Koschan, Merry; Melcher, Charles L.

    2014-10-17

    To control the time-response performance of widely used cerium-activated scintillators in cutting-edge medical-imaging devices, such as time-of-flight positron-emission tomography, a comprehensive understanding of the role of Ce valence states, especially stable Ce4+, in the scintillation mechanism is essential. However, despite some progress made recently, an understanding of the physical processes involving Ce4+ is still lacking. The aim of this work is to clarify the role of Ce4+ in scintillators by studying Ca2+ codoped Gd3Ga3Al2O12∶Ce (GGAG∶Ce). By using a combination of optical absorption spectra and x-ray absorption near-edge spectroscopies, the correlation between Ca2+codoping content and the Ce4+ fraction is seen. The energy-levelmore »diagrams of Ce3+ and Ce4+ in the Gd3Ga3Al2O12 host are established by using theoretical and experimental methods, which indicate a higher position of the 5d1 state of Ce4+ in the forbidden gap in comparison to that of Ce3+. Underlying reasons for the decay-time acceleration resulting from Ca2+ codoping are revealed, and the physical processes of the Ce4+-emission model are proposed and further demonstrated by temperature-dependent radioluminescence spectra under x-ray excitation.« less

  16. Role of Ce4+ in the scintillation mechanism of codoped Gd3Ga3Al2O12:Ce

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

    Wu, Yuntao; Meng, Fang; Li, Qi; Koschan, Merry; Melcher, Charles L.

    2014-10-17

    To control the time-response performance of widely used cerium-activated scintillators in cutting-edge medical-imaging devices, such as time-of-flight positron-emission tomography, a comprehensive understanding of the role of Ce valence states, especially stable Ce4+, in the scintillation mechanism is essential. However, despite some progress made recently, an understanding of the physical processes involving Ce4+ is still lacking. The aim of this work is to clarify the role of Ce4+ in scintillators by studying Ca2+ codoped Gd3Ga3Al2O12∶Ce (GGAG∶Ce). By using a combination of optical absorption spectra and x-ray absorption near-edge spectroscopies, the correlation between Ca2+codoping content and the Ce4+ fraction is seen. The energy-levelmore » diagrams of Ce3+ and Ce4+ in the Gd3Ga3Al2O12 host are established by using theoretical and experimental methods, which indicate a higher position of the 5d1 state of Ce4+ in the forbidden gap in comparison to that of Ce3+. Underlying reasons for the decay-time acceleration resulting from Ca2+ codoping are revealed, and the physical processes of the Ce4+-emission model are proposed and further demonstrated by temperature-dependent radioluminescence spectra under x-ray excitation.« less

  17. Zebra processes of oil recovery using fireflood and waterflood in alternate sands in a multi-sand environment

    SciTech Connect (OSTI)

    Chu, C.

    1995-12-31

    This paper presents a new process of oil recovery, namely, the zebra process, which is specifically advantageous to use in heavy oil reservoirs that exist in multiple sands. This process uses firefloods and waterfloods in alternate sands. The firefloods serve as formation preheaters which reduce the oil viscosities in the neighboring sands so that these sands, normally not amenable to waterfloods because of high viscosity, can be waterflooded with ease. The exciting news is that the air compression cost in firefloods can be reduced by a factor of three with a proper application of the zebra process. This great savings in air compression cost is possible because the heat that is normally lost to the overburden and underburden in firefloods is now being put to good use, by preheating the neighboring sands. Examples are given on zebraing several idealized sand-shale sequences involving three-, five-, six-, and seven-sand reservoirs, and also zebraing two actual sand-shale sequences, both involving five-sand reservoirs.

  18. The extraction of bitumen from western tar sands. Annual report

    SciTech Connect (OSTI)

    Oblad, A.G.; Bunger, J.W.; Deo, M.D.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1990-07-01

    Topics discussed include: characterization of bitumen impregnated sandstone, water based tar sand separation technology, electrophoretic characterization of bitumen and fine mineral particles, bitumen and tar sand slurry viscosity, the hot water digestion-flotation process, electric field use on breaking water-in-oil emulsions, upgrading of bitumens and bitumen-derived liquids, solvent extraction.

  19. The extraction of bitumen from western tar sands

    SciTech Connect (OSTI)

    Oblad, A.G.; Bunger, J.W.; Deo, M.D.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1990-07-01

    Topics discussed include: characterization of bitumen impregnated sandstone, water based tar sand separation technology, electrophoretic characterization of bitumen and fine mineral particles, bitumen and tar sand slurry viscosity, the hot water digestion-flotation process, electric field use on breaking water-in-oil emulsions, upgrading of bitumens and bitumen-derived liquids, solvent extraction.

  20. China shows increasing interest in heavy oil and oil sands

    SciTech Connect (OSTI)

    Not Available

    1986-12-01

    China and Canadian and US groups are cooperating in several areas to develop the heavy oil, asphalt, and oil sand deposits of China. The agreements dealing with exploration and upgrading are briefly described. The majority of the paper describes the occurrences of heavy oil, asphalt, and oil sands in China. 1 figure.

  1. Acoustic sand detector for fluid flowstreams

    DOE Patents [OSTI]

    Beattie, Alan G. (Corrales, NM); Bohon, W. Mark (Frisco, TX)

    1993-01-01

    The particle volume and particle mass production rate of particulate solids entrained in fluid flowstreams such as formation sand or fracture proppant entrained in oil and gas production flowstreams is determined by a system having a metal probe interposed in a flow conduit for transmitting acoustic emissions created by particles impacting the probe to a sensor and signal processing circuit which produces discrete signals related to the impact of each of the particles striking the probe. The volume or mass flow rate of particulates is determined from making an initial particle size distribution and particle energy distribution and comparing the initial energy distribution and/or the initial size distribution with values related to the impact energies of a predetermined number of recorded impacts. The comparison is also used to recalibrate the system to compensate for changes in flow velocity.

  2. Direct Production of Silicones From Sand

    SciTech Connect (OSTI)

    Larry N. Lewis; F.J. Schattenmann: J.P. Lemmon

    2001-09-30

    Silicon, in the form of silica and silicates, is the second most abundant element in the earth's crust. However the synthesis of silicones (scheme 1) and almost all organosilicon chemistry is only accessible through elemental silicon. Silicon dioxide (sand or quartz) is converted to chemical-grade elemental silicon in an energy intensive reduction process, a result of the exceptional thermodynamic stability of silica. Then, the silicon is reacted with methyl chloride to give a mixture of methylchlorosilanes catalyzed by cooper containing a variety of tract metals such as tin, zinc etc. The so-called direct process was first discovered at GE in 1940. The methylchlorosilanes are distilled to purify and separate the major reaction components, the most important of which is dimethyldichlorosilane. Polymerization of dimethyldichlorosilane by controlled hydrolysis results in the formation of silicone polymers. Worldwide, the silicones industry produces about 1.3 billion pounds of the basic silicon polymer, polydimethylsiloxane.

  3. Method and apparatus for hydrocarbon recovery from tar sands

    DOE Patents [OSTI]

    Westhoff, James D.; Harak, Arnold E.

    1989-01-01

    A method and apparatus for utilizing tar sands having a broad range of bitumen content is disclosed. More particularly, tar sands are pyrolyzed in a cyclone retort with high temperature gases recycled from the cyclone retort to produce oil and hydrocarbon products. The spent tar sands are then burned at 2000.degree. F. in a burner to remove residual char and produce a solid waste that is easily disposable. The process and apparatus have the advantages of being able to utilize tar sands having a broad range of bitumen content and the advantage of producing product gases that are free from combustion gases and thereby have a higher heating value. Another important advantage is rapid pyrolysis of the tar sands in the cyclone so as to effectively utilize smaller sized reactor vessels for reducing capitol and operating costs.

  4. Method and apparatus for hydrocarbon recovery from tar sands

    DOE Patents [OSTI]

    Westhoff, J.D.; Harak, A.E.

    1988-05-04

    A method and apparatus for utilizing tar sands having a broad range of bitumen content is disclosed. More particularly, tar sands are pyrolyzed in a cyclone retort with high temperature gases recycled from the cyclone retort to produce oil and hydrocarbon products. The spent tar sands are then burned at 2000/degree/F in a burner to remove residual char and produce a solid waste that is easily disposable. The process and apparatus have the advantages of being able to utilize tar sands having a broad range of bitumen content and the advantage of producing product gases that are free from combustion gases and thereby have a higher heating value. Another important advantage is rapid pyrolysis of the tar sands in the cyclone so as to effectively utilize smaller sized reactor vessels for reducing capitol and operating costs. 1 fig., 1 tab.

  5. Crane: Order (2016-CE-52001) | Department of Energy

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

    Order (2016-CE-52001) Crane: Order (2016-CE-52001) January 21, 2016 DOE ordered Crane Merchandising Systems, Inc. to pay a $16,000 civil penalty after finding Crane had failed to certify that certain models of refrigerated bottled or canned beverage vending machines comply with the applicable energy conservation standards. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Crane. Crane: Order (2016-CE-52001) (23.16 KB) More Documents & Publications

  6. Temspec: Order (2016-CE-43002) | Department of Energy

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

    Order (2016-CE-43002) Temspec: Order (2016-CE-43002) March 21, 2016 DOE ordered Temspec Incorporated to pay a $8,000 civil penalty after finding Temspec had failed to certify that certain models of single package vertical air conditioning and heating equipment comply with the applicable energy conservation standards. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Temspec. Temspec: Order (2016-CE-43002) (92.11 KB) More Documents & Publications

  7. Atosa: Order (2015-CE-42037) | Department of Energy

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

    Order (2015-CE-42037) Atosa: Order (2015-CE-42037) August 31, 2015 DOE ordered Atosa Catering Equipment, Inc. to pay a $8,000 civil penalty after finding Atosa had failed to certify that certain models of self-contained commercial refrigeration equipment with doors comply with the applicable energy conservation standards. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Atosa. Atosa: Order (2015-CE-42037) (26.71 KB) More Documents & Publications

  8. Herbeau: Order (2015-CE-28005) | Department of Energy

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

    Order (2015-CE-28005) Herbeau: Order (2015-CE-28005) March 9, 2016 DOE ordered Herbeau Creations of America, Inc. to pay a $8,000 civil penalty after finding Herbeau had failed to certify that certain models of faucets and showerheads comply with the applicable water conservation standards. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Herbeau. Herbeau: Order (2015-CE-28005) (16.61 KB) More Documents & Publications Herbeau: Proposed Penalty

  9. CE2 Capital Partners LLC | Open Energy Information

    Open Energy Info (EERE)

    Capital Partners LLC Jump to: navigation, search Name: CE2 Capital Partners LLC Place: Solana Beach, California Zip: 92075 Sector: Carbon, Renewable Energy Product:...

  10. PQL: Order (2013-CE-27001) | Department of Energy

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

    PQL: Order (2013-CE-27001) PQL: Order (2013-CE-27001) August 7, 2015 DOE ordered P.Q.L, Inc. to pay a $12,500 civil penalty after finding PQL had failed to certify that certain models of medium base compact fluorescent lamps comply with the applicable energy conservation standards. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and PQL. PQL: Order (2013-CE-27001) (17.34 KB) More Documents & Publications PQL: Proposed Penalty (2013-CE-27001) PQL: Order

  11. Thermoelectric Couple Demonstration of (In, Ce)-based Skutterudite...

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

    Presents recent accomplishments and couple test results with these (In, Ce)-based skutterudite TE materials and potential impacts TE power system performance in military and ...

  12. Lattice Disorder And Size-Induced Kondo Behavior in CeAl(2) And CePt(2+X)

    SciTech Connect (OSTI)

    Han, S.-W.; Booth, C.H.; Bauer, E.D.; Huang, P.H.; Chen, Y.Y.; Lawrence, J.M.; /LBL, Berkeley /Chonbuk Natl. U. /Los Alamos /Taiwan, Inst. Phys. /UC, Irvine

    2007-07-19

    When the particle size of CeAl{sub 2} and CePt{sub 2+x} samples is reduced to the nanometer scale, antiferromagnetism is suppressed and Kondo behavior dominates. We find that the Kondo temperature T{sub K} can either decrease (CeAl{sub 2}) or increase (CePt{sub 2+x}) in the nanoparticles relative to the bulk. Extended x-ray absorption fine-structure data show that the Ce-Al and Ce-Pt environments are significantly distorted in the nanoparticles. While such distortions should strongly affect magnetic and electronic properties, we find they cannot explain the observed changes in T{sub K}. Changes in the conduction density of states or other parameters must, therefore, play a significant role.

  13. Lattice disorder and size-induced Kondo behavior in CeAl2 andCePt2+x

    SciTech Connect (OSTI)

    Han, S.-W.; Booth, C.H.; Bauer, E.D.; Huang P.H.; Chen, Y.Y.; Lawrence, J.M.

    2006-03-14

    When the particle size of CeAl{sub 2} and CePt{sub 2+x} samples is reduced to the nanometer scale, antiferromagnetism is suppressed and Kondo behavior dominates. We find that the Kondo temperature T{sub K} can either decrease (CeAl{sub 2}) or increase (CePt{sub 2+x}) in the nanoparticles relative to the bulk. Extended x-ray absorption fine-structure data show that the Ce-Al and Ce-Pt environments are significantly distorted in the nanoparticles. While such distortions should strongly affect magnetic and electronic properties, we find they cannot explain the observed changes in T{sub K}. Changes in the conduction density of states or other parameters must, therefore, play a significant role.

  14. Montana Notice of Intent: Sand and Gravel General Permit (MDEQ...

    Open Energy Info (EERE)

    Form NOI) Jump to: navigation, search OpenEI Reference LibraryAdd to library Form: Montana Notice of Intent: Sand and Gravel General Permit (MDEQ Form NOI) Abstract Form to be...

  15. Heavy oil and tar sands recovery and upgrading. International technology

    SciTech Connect (OSTI)

    Schumacher, M.M.

    1982-01-01

    This work provides an in-depth assessment of international technology for the recovery and upgrading of heavy crude oil and tar sands. The technologies included are currently in use, under development, or planned; emphasis is placed on post-1978 activities. The heavy oil technologies and processes considered include methods relating to the exploitation of heavy oil reservoirs, such as production from underground workings, all types of improved or enhanced recovery, subsurface extraction, and well rate stimulation. The tar sands section includes sizing the resource base and reviewing and evaluating past, present, and planned research and field developments on processes for mining, producing, extracting, and upgrading very heavy oils recovered from tar sands, e.g., bitumen recovery from tar sands where primary production was impossible because of the oil's high viscosity. 616 references.

  16. SANDIA REPORT SAND2013-5238 Unlimited Release

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

    5238 Unlimited Release July 2013 Water Use and Supply Concerns for Utility-Scale Solar ... SAND2013-5238 Unlimited Release July 2013 Water Use and Supply Concerns for Utility-Scale ...

  17. Nondestructive Evaluation and Monitoring Projects NASA White Sands Test

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

    Facility (WSTF) | Department of Energy Nondestructive Evaluation and Monitoring Projects NASA White Sands Test Facility (WSTF) Nondestructive Evaluation and Monitoring Projects NASA White Sands Test Facility (WSTF) These slides were presented at the Onboard Storage Tank Workshop on April 29, 2010. nondestructiveevaluation_nasa_ostw.pdf (1.93 MB) More Documents & Publications Non Destructive Evaluation (NDE) Methods for Certification and Production/Performance Monitoring of Composite

  18. Western tight gas sands advanced logging workshop proceedings

    SciTech Connect (OSTI)

    Jennings, J B; Carroll, Jr, H B

    1982-04-01

    An advanced logging research program is one major aspect of the Western Tight Sands Program. Purpose of this workshop is to help BETC define critical logging needs for tight gas sands and to allow free interchange of ideas on all aspects of the current logging research program. Sixteen papers and abstracts are included together with discussions. Separate abstracts have been prepared for the 12 papers. (DLC)

  19. Creating and maintaining a gas cap in tar sands formations

    DOE Patents [OSTI]

    Vinegar, Harold J. (Bellaire, TX); Karanikas, John Michael (Houston, TX); Dinkoruk, Deniz Sumnu (Houston, TX); Wellington, Scott Lee (Bellaire, TX)

    2010-03-16

    Methods for treating a tar sands formation are disclosed herein. Methods for treating a tar sands formation may include providing heat to at least part of a hydrocarbon layer in the formation from one or more heaters located in the formation. Pressure may be allowed to increase in an upper portion of the formation to provide a gas cap in the upper portion. At least some hydrocarbons are produced from a lower portion of the formation.

  20. The extraction of bitumen from western tar sands. Annual report, July 1990--July 1991

    SciTech Connect (OSTI)

    Oblad, A.G.; Bunger, J.W.; Deo, M.D.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1992-04-01

    Contents of this report include the following: executive summary; characterization of the native bitumen from the Whiterocks oil sand deposit; influence of carboxylic acid content on bitumen viscosity; water based oil sand separation technology; extraction of bitumen from western oil sands by an energy-efficient thermal method; large- diameter fluidized bed reactor studies; rotary kiln pyrolysis of oil sand; catalytic upgrading of bitumen and bitumen derived liquids; ebullieted bed hydrotreating and hydrocracking; super critical fluid extraction; bitumen upgrading; 232 references; Appendix A--Whiterocks tar sand deposit bibliography; Appendix B--Asphalt Ridge tar sand deposit bibliography; and Appendix C--University of Utah tar sands bibliography.

  1. Processing of transparent polycrystalline AlON:Ce3+ scintillators

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

    Chen, Ching -Fong; Yang, Pin; King, Graham; Tegtmeier, Eric L.

    2015-10-23

    A new polycrystalline ceramic scintillator is reported for potential use in radiation detection and medical imaging applications. The goal was to develop cerium-activated aluminum oxynitride (AlON:Ce3+) ceramics, which can be produced using ceramic processes in comparison to the high-cost, low-yield single-crystal growth technique. A phase pure AlON:Ce3+ powder with cubic symmetry was successfully synthesized at high temperature under a reducing atmosphere to convert Ce4+ to Ce3+ in the solid solution. We explored two different activator concentrations (0.5 and 1.0 mol%). Fully dense and transparent AlON:Ce3+ ceramics were produced by a liquid-phase-assisted pressureless sintering. The crystal field splitting around the Ce3+more » activator in the AlON was comparable to the splitting induced by Br₋ and the Cl₋ ligands, which produced an emission spectrum perfectly matching the maximum quantum efficiency range of the photomultiplier tube for radiation detection. Both optical excitation and radiation ionizations in AlON:Ce3+ were demonstrated. Lastly, challenges and mechanisms related to the radioluminescence efficiency are discussed.« less

  2. Evidence of dynamical spin shielding in Ce from spin-resolved...

    Office of Scientific and Technical Information (OSTI)

    Evidence of dynamical spin shielding in Ce from spin-resolved photoelectron spectroscopy Citation Details In-Document Search Title: Evidence of dynamical spin shielding in Ce from ...

  3. Sedimentary structures and textures of Rio Orinoco channel sands, Venezuela and Colombia

    SciTech Connect (OSTI)

    McKee, E.D.

    1989-01-01

    The majority of the sedimentary structures in the channel sands of the Orinoco River are planar cross-strata that are products of sand-wave deposition. Sands in these deposits are mostly medium-grained. Eolian dunes form on top of the sand waves when they are exposed to the trade winds at low river stages. The windblown sands are typically fine-grained.

  4. Maxlite: Order (2010-CE-2701) | Department of Energy

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

    Maxlite: Order (2010-CE-2701) Maxlite: Order (2010-CE-2701) In the Matter of Maxlite, SK America, Inc. (general service flourescent lamps), DOE Case Number 2010-CE-2701, Adopting Order and Compromise Agreement. Order adopting accompanying Compromise Agreement. DOE found that Maxlite failed to submit compliance certifications for its products under 10 C.F.R. Section 430.62, and here assesses a civil penalty of $5,000 (if paid within 30 days) or of $10,000 (if paid between 31-60 days). Maxlite

  5. CE2 Carbon Capital LLC | Open Energy Information

    Open Energy Info (EERE)

    Carbon Capital LLC Jump to: navigation, search Name: CE2 Carbon Capital LLC Place: California Sector: Carbon, Renewable Energy Product: US-based carbon trader that looks to take...

  6. Paragon Sales: Order (2012-CE-1417) | Department of Energy

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

    Order (2012-CE-1417) July 30, 2012 DOE ordered Paragon Sales Co., Inc., to pay a 6,000 civil penalty after finding Paragon Sales had failed to certify that certain models of...

  7. Manitowoc Foodservice: Order (2012-CE-5309) | Department of Energy

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

    Order (2012-CE-5309) July 20, 2012 DOE ordered Manitowoc Foodservice to pay an 6,000 civil penalty after finding Manitowoc Foodservice had failed to certify that Manitowoc...

  8. Electrolux: Order (2012-CE-1901) | Department of Energy

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

    Order (2012-CE-1901) July 27, 2012 DOE ordered Electrolux North America to pay a 6,500 civil penalty after finding Electrolux had failed to certify that certain dishwashers comply...

  9. Haier: Order (2011-CE-2104) | Department of Energy

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

    Haier: Order (2011-CE-2104) June 12, 2012 DOE ordered Haier to pay an 20,000 civil penalty after finding Haier had failed to certify that Haier residential clothes...

  10. Danby Products: Order (2012-CE-1415) | Department of Energy

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

    Order (2012-CE-1415) August 9, 2012 DOE ordered Danby Products to pay a 9,900 civil penalty after finding Danby had failed to certify that certain models of refrigerators...

  11. Lochinvar: Order (2016-CE-24001) | Department of Energy

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

    Lochinvar: Order (2016-CE-24001) Lochinvar: Order (2016-CE-24001) November 2, 2015 DOE ordered Lochinvar, LLC, to pay a $8,000 civil penalty after finding Lochinvar had failed to certify that certain models of pool heaters comply with the applicable energy conservation standard. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Lochinvar. DOE regulations require a manufacturer (which includes importers) to submit reports certifying that its products have

  12. Fujitsu: Order (2015-CE-16014) | Department of Energy

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

    Fujitsu: Order (2015-CE-16014) Fujitsu: Order (2015-CE-16014) October 27, 2015 DOE ordered Fujitsu General America, Inc. to pay a $8,000 civil penalty after finding Fujitsu had failed to certify that certain models of central air conditioners and heat pumps comply with the applicable energy conservation standards prior to distributing them in commerce. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Fujitsu. DOE regulations require a manufacturer (which

  13. Systemair: Order (2016-CE-43003) | Department of Energy

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

    Systemair: Order (2016-CE-43003) Systemair: Order (2016-CE-43003) February 23, 2016 DOE ordered Systemair, Inc., to pay a $8,000 civil penalty after finding Systemair had failed to certify that its single package vertical air conditioning and heating equipment comply with the applicable energy conservation standards. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Systemair. DOE regulations require a manufacturer (which includes importers) to submit

  14. Temspec: Proposed Penalty (2016-CE-43002) | Department of Energy

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

    Proposed Penalty (2016-CE-43002) Temspec: Proposed Penalty (2016-CE-43002) February 5, 2016 DOE alleged in a Notice of Proposed Civil Penalty that Temspec Incorporated failed to certify various basic models of single package vertical air conditioning and heating equipment as compliant with the applicable energy conservation standards. DOE regulations require a manufacturer (which includes importers) to submit reports certifying that its products have been tested and meet the applicable energy

  15. Utility: Proposed Penalty (2016-CE-42007) | Department of Energy

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

    Proposed Penalty (2016-CE-42007) Utility: Proposed Penalty (2016-CE-42007) November 30, 2015 DOE alleged in a Notice of Proposed Civil Penalty that Utility Refrigerator failed to certify certain commercial refrigerator equipment as compliant with the applicable energy conservation standards. DOE regulations require a manufacturer (which includes importers) to submit reports certifying that its products have been tested and meet the applicable energy conservation standards. This civil penalty

  16. Ca2+-Doped CeBr3 Scintillating Materials

    SciTech Connect (OSTI)

    Guss, Paul; Foster, Michael E.; Wong, Bryan M.; Doty, F. Patrick; Shah, Kanai; Squillante, Michael R.; Shirwadkar, Urmila; Hawrami, Rastgo; Tower, Josh; Yuan, Ding

    2014-01-21

    Despite the outstanding scintillation performance characteristics of cerium tribromide (CeBr3) and cerium-activated lanthanum tribromide, their commercial availability and application are limited due to the difficulties of growing large, crack-free single crystals from these fragile materials. This investigation employed aliovalent doping to increase crystal strength while maintaining the optical properties of the crystal. One divalent dopant (Ca2+) was used as a dopant to strengthen CeBr3 without negatively impacting scintillation performance. Ingots containing nominal concentrations of 1.9% of the Ca2+ dopant were grown. Preliminary scintillation measurements are presented for this aliovalently doped scintillator. Ca2+-doped CeBr3 exhibited little or no change in the peak fluorescence emission for 371 nm optical excitation for CeBr3. The structural, electronic, and optical properties of CeBr3 crystals were studied using the density functional theory within the generalized gradient approximation. The calculated lattice parameters are in good agreement with the experimental data. The energy band structures and density of states were obtained. The optical properties of CeBr3, including the dielectric function, were calculated.

  17. Investigation of guided waves propagation in pipe buried in sand

    SciTech Connect (OSTI)

    Leinov, Eli; Cawley, Peter; Lowe, Michael J.S.

    2014-02-18

    The inspection of pipelines by guided wave testing is a well-established method for the detection of corrosion defects in pipelines, and is currently used routinely in a variety of industries, e.g. petrochemical and energy. When the method is applied to pipes buried in soil, test ranges tend to be significantly compromised because of attenuation of the waves caused by energy radiating into the soil. Moreover, the variability of soil conditions dictates different attenuation characteristics, which in-turn results in different, unpredictable, test ranges. We investigate experimentally the propagation and attenuation characteristics of guided waves in pipes buried in fine sand using a well characterized full scale experimental apparatus. The apparatus consists of an 8 inch-diameter, 5.6-meters long steel pipe embedded over 3 meters of its length in a rectangular container filled with fine sand, and an air-bladder for the application of overburden pressure. Longitudinal and torsional guided waves are excited in the pipe and recorded using a transducer ring (Guided Ultrasonics Ltd). Acoustic properties of the sand are measured independently in-situ and used to make model predictions of wave behavior in the buried pipe. We present the methodology and the systematic measurements of the guided waves under a range of conditions, including loose and compacted sand. It is found that the application of overburden pressure modifies the compaction of the sand and increases the attenuation, and that the measurement of the acoustic properties of sand allows model prediction of the attenuation of guided waves in buried pipes with a high level of confidence.

  18. Comparison of the high-pressure behavior of the cerium oxides Ce2O3 and CeO2

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

    Lipp, M. J.; Jeffries, J. R.; Cynn, H.; Park Klepeis, J. -H.; Evans, W. J.; Mortensen, D. R.; Seidler, G. T.; Xiao, Y.; Chow, P.

    2016-02-09

    We studied the high-pressure behavior of Ce2O3 using angle-dispersive x-ray diffraction to 70 GPa and compared with that of CeO2. Up to the highest pressure Ce2O3 remains in the hexagonal phase (space group 164, P ¯32/m1) typical for the lanthanide sesquioxides. We did not observe a theoretically predicted phase instability for 30 GPa. The isothermal bulk modulus and its pressure derivative for the quasihydrostatic case are B0 = 111 ± 2 GPa, B'0 = 4.7 ± 0.3, and for the case without pressure-transmitting medium B0 = 104 ±4 GPa, B'0 = 6.5 ± 0.4. Starting from ambient-pressure magnetic susceptibility measurementsmore » for both oxides in highly purified form,we find that the Ce atom in Ce2O3 behaves like a trivalent Ce3+ ion (2.57μB per Ce atom) in contrast to previously published data. Since x-ray emission spectroscopy of the Lγ (4d3/2 → 2p1/2) transition is sensitive to the 4f -electron occupancy, we also followed the high-pressure dependence of this line for both oxides up to 50 GPa. We observed no change of the respective line shape, indicating that the 4f -electron configuration is stable for both materials. We posit from this data that the 4f electrons do not drive the volume collapse of CeO2 from the high-symmetry, low-pressure fluorite structure to the lower-symmetry orthorhombic phase.« less

  19. Milling of Sand Blocks to Make Casting Moulds

    SciTech Connect (OSTI)

    Lopez de Lacalle, L. N.; Rodriguez, A.; Lamikiz, A.; Penafiel, F. J. [Department of Mechanical Engineering, University of the Basque Country, ETSII, c/Alameda de Urquijo s/n, 48013 Bilbao (Spain)

    2011-01-17

    In this paper a full procedure to make moulds in sand for direct casting of metallic parts is presented. The technology aims at unique pieces or art pieces, where only one prototype or components is required, but lead times are much reduced. The key of the procedure is to achieve enough tool life when milling with carbide tools, avoiding the risk of sand destruction or damage.The use of inverse techniques is a common input due to the industrial sectors where the direct milling is interesting. Two examples of moulds are presented, evaluating times and costs. A special study of tool wear is also presented.

  20. Case study of a multiple sand waterflood, Hewitt Unit, OK

    SciTech Connect (OSTI)

    Ruble, D.B.

    1982-03-01

    Twenty-two sands in the Hewitt field have been flooded simultaneously by Exxon Co. U.S.A.'s Hewitt Unit, and a case history of the operations is detailed. A multiple sand waterflood project requires special optimization methods to improve oil recovery. Injection and production surveillance programs and optimization methods used are highlighted. These include injection wellbore design, injection distribution, production stimulation, polymer augmented injection, and infill drilling. Successful application of these techniques has increased ultimate recovery from this waterflood operation. 3 refs.

  1. Western Gas Sands Project: stratigrapy of the Piceance Basin

    SciTech Connect (OSTI)

    Anderson, S.

    1980-08-01

    The Western Gas Sands Project Core Program was initiated by US DOE to investigate various low permeability, gas bearing sandstones. Research to gain a better geological understanding of these sandstones and improve evaluation and stimulation techniques is being conducted. Tight gas sands are located in several mid-continent and western basins. This report deals with the Piceance Basin in northwestern Colorado. This discussion is an attempt to provide a general overview of the Piceance Basin stratigraphy and to be a useful reference of stratigraphic units and accompanying descriptions.

  2. Heavy liquid beneficiation developed for Alabama tar sands

    SciTech Connect (OSTI)

    Not Available

    1986-12-01

    The tar sand deposits in the State of Alabama contain about 1.8 billion barrels of measured and more than 4 billion barrels of speculative in-place bitumen. A comprehensive research program is in progress for the separation of bitumen from these deposits. In general, Alabama tar sands are oil wetted, low grade and highly viscous in nature. In view of these facts, a beneficiation strategy has been developed to recover bitumen enriched concentrate which can be used as a feed material for further processing. Heavy liquid separation tests and results are discussed. A 77% zinc bromide solution, specific gravity of 2.4, was used for the tests. 2 figures.

  3. Patriotic Sands Form the Science of Summer | GE Global Research

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

    Patriotic Sands Form the Science of Summer Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click to share (Opens in new window) Click to share on LinkedIn (Opens in new window) Click to share on Tumblr (Opens in new window) Patriotic Sands Form the Science of Summer Adam Rasheed 2012.07.03 Happy 4th of July everyone! As we gear up to celebrate Independence Day with fireworks and barbecues in the sweltering heat, we wanted to figure out a fun way to

  4. Effects of CeO2 Support Facets on VOx/CeO2 Catalysts in Oxidative Dehydrogenation of Methanol

    SciTech Connect (OSTI)

    Li, Yan; Wei, Zhehao; Gao, Feng; Kovarik, Libor; Peden, Charles HF; Wang, Yong

    2014-05-13

    CeO2 supports with dominating facets, i.e., low index (100), (110) and (111) facets, are prepared. The facet effects on the structure and catalytic performance of supported vanadium oxide catalysts are investigated using oxidative dehydrogenation of methanol as a model reaction. In the presence of mixed facets, Infrared and Raman characterizations demonstrate that surface vanadia species preferentially deposit on CeO2 (100) facets, presumably because of its higher surface energy. At the same surface vanadium densities, VOx species on (100) facets show better dispersion, followed by (110) and (111) facets. The VOx species on CeO2 nanorods with (110) and (100) facets display higher activity and lower apparent activation energies compared to that on CeO2 nanopolyhedras with dominating (111) facets and CeO2 nanocubes with dominating (100) facets. The higher activity for VOx/CeO2(110) might be related to the more abundant oxygen vacancies present on the (110) facets, evidenced from Raman spectroscopic measurements.

  5. Ecology of Pacific Northwest coastal sand dunes: a community profile

    SciTech Connect (OSTI)

    Wiedemann, A.M.

    1984-03-01

    Sand dunes occur in 33 localities along the 950 km of North American Pacific coast between the Straits of Juan de Fuca (49/sup 0/N) and Cape Mendocino (40/sup 0/). The dune landscape is a mosaic of dune forms: transverse ridge, oblique dune, retention ridge, foredune, parabola dune, sand hummock, blowout, sand plain, deflation plain, dune ridge, swale, remnant forest, and ponds and lakes. These forms are the basic morphological units making up the four dune systems: parallel ridge, parabola dune, transverse ridge, and bay dune. Vegetation is well-developed on stabilized dunes. Of the 21 plant communities identified, nine are herbaceous, five are shrub, and seven are forest. A wide variety of vertebrate animals occur in seven distinct habitats: open dunes, grassland and meadow, shrub thicket, forest, marsh, riparian, and lakes and ponds. Urban development, increased rate of stabilization due to the introduction of European beachgrass (Ammophila arenaria (L.) Link), and massive disturbance resulting from heavy off-road vehicle traffic are the greatest threats to the long-term survival and stability of a number of sand dune habitats. Two animals and three plants dependent on dune habitats are listed as rare, threatened, or endangered. 93 references, 52 figures, 13 tables.

  6. Sediment volume in the north polar sand seas of Mars

    SciTech Connect (OSTI)

    Lancaster, N.; Greeley, R. (Arizona State Univ., Tempe (USA))

    1990-07-10

    Data from studies of the cross-sectional area of terrestrial transverse dunes have been combined with maps of dune morphometry derived from Viking orbiter images to generate new estimates of sediment thickness and dune sediment volume in the north polar sand seas of Mars. A relationship between dune spacing and equivalent sediment thickness (EST) was developed from field data on Namibian and North American dunes and was applied to data on dune spacing and dune cover measured on Viking orbiter images to generate maps of dune sediment thickness for Martian north polar sand seas. There are four major sand seas in the north polar region of Mars, covering an area of 6.8 x 10{sup 5} km{sup 2}. Equivalent sediment thickness ranges between 0.5 and 6.1 m with a mean of 1.8 m. The sand seas contain a total of 1158 km{sup 3} of dune sediment, which may have been derived by erosion of polar layered deposits and concentrated in its present location by winds that change direction seasonally.

  7. In situ recovery of oil from Utah tar sand: a summary of tar sand research at the Laramie Energy Technology Center

    SciTech Connect (OSTI)

    Marchant, L.C.; Westhoff, J.D.

    1985-10-01

    This report describes work done by the United States Department of Energy's Laramie Energy Technology Center from 1971 through 1982 to develop technology for future recovery of oil from US tar sands. Work was concentrated on major US tar sand deposits that are found in Utah. Major objectives of the program were as follows: determine the feasibility of in situ recovery methods applied to tar sand deposits; and establish a system for classifying tar sand deposits relative to those characteristics that would affect the design and operation of various in situ recovery processes. Contents of this report include: (1) characterization of Utah tar sand; (2) laboratory extraction studies relative to Utah tar sand in situ methods; (3) geological site evaluation; (4) environmental assessments and water availability; (5) reverse combustion field experiment, TS-1C; (6) a reverse combustion followed by forward combustion field experiment, TS-2C; (7) tar sand permeability enhancement studies; (8) two-well steam injection experiment; (9) in situ steam-flood experiment, TS-1S; (10) design of a tar sand field experiment for air-stream co-injection, TS-4; (11) wastewater treatment and oil analyses; (12) economic evaluation of an in situ tar sand recovery process; and (13) appendix I (extraction studies involving Utah tar sands, surface methods). 70 figs., 68 tabs.

  8. An Update on NiCE Support for BISON

    SciTech Connect (OSTI)

    McCaskey, Alex; Billings, Jay Jay; Deyton, Jordan H.; Wojtowicz, Anna

    2015-09-01

    The Nuclear Energy Advanced Modeling and Simulation program (NEAMS) from the Department of Energy s Office of Nuclear Energy has funded the development of a modeling and simulation workflow environment to support the various codes in its nuclear energy scientific computing toolkit. This NEAMS Integrated Computational Environment (NiCE) provides extensible tools and services that enable efficient code execution, input generation, pre-processing visualizations, and post-simulation data analysis and visualization for a large portion of the NEAMS Toolkit. A strong focus for the NiCE development team throughout FY 2015 has been support for the Multiphysics Object Oriented Simulation Environment (MOOSE) and the NEAMS nuclear fuel performance modeling application built on that environment, BISON. There is a strong desire in the program to enable and facilitate the use of BISON throughout nuclear energy research and industry. A primary result of this desire is the need for strong support for BISON in NiCE. This report will detail improvements to NiCE support for BISON. We will present a new and improved interface for interacting with BISON simulations in a variety of ways: (1) improved input model generation, (2) embedded mesh and solution data visualizations, and (3) local and remote BISON simulation launch. We will also show how NiCE has been extended to provide support for BISON code development.

  9. TO:

    Office of Legacy Management (LM)

    would buy from the Davison Chemical Company thorium hydrcxide which they had processed. ... would in turn supply the AEC the thorium hydroxide they processed from the monazite sands. ...

  10. The extraction of bitumen from western oil sands. Final report, July 1989--September 1993

    SciTech Connect (OSTI)

    Oblad, A.G.; Bunger, J.W.; Dahlstrom, D.A.; Deo, M.D.; Fletcher, J.V.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1994-03-01

    Research and development of surface extraction and upgrading processes of western tar sands are described. Research areas included modified hot water, fluidized bed, and rotary kiln pyrolysis of tar sands for extraction of bitumen. Bitumen upgrading included solvent extraction of bitumen, and catalytic hydrotreating of bitumen. Characterization of Utah tar sand deposits is also included.

  11. Homoleptic Ce(III) and Ce(IV) Nitroxide Complexes: Significant Stabilization of the 4+ Oxidation State

    SciTech Connect (OSTI)

    Bogart, Justin A.; Lewis, Andrew J.; Medling, Scott A.; Piro, Nicholas A.; Carroll, Patrick J.; Booth, Corwin H.; Schelter, Eric J.

    2014-06-25

    Electrochemical experiments performed on the complex Ce-IV[2-((BuNO)-Bu-t)py](4), where [2-((BuNO)-Bu-t)py](-) = N-tert-butyl-N-2-pyridylnitroxide, indicate a 2.51 V stabilization of the 4+ oxidation state of Ce compared to [(Bu4N)-Bu-n](2)[Ce(NO3)(6)] in acetonitrile and a 2.95 V stabilization compared to the standard potential for the ion under aqueous conditions. Density functional theory calculations suggest that this preference for the higher oxidation state is a result of the tetrakis(nitroxide) ligand framework at the Ce cation, which allows for effective electron donation into, and partial covalent overlap with, vacant 4f orbitals with delta symmetry. The results speak to the behavior of CeO2 and related solid solutions in oxygen uptake and transport applications, in particular an inherent local character of bonding that stabilizes the 4+ oxidation state. The results indicate a cerium(IV) complex that has been stabilized to an unprecedented degree through tuning of its ligand-field environment.

  12. SANDIA REPORT SAND2014-1535 Unlimited Release

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

    SANDIA REPORT SAND2014-1535 Unlimited Release Printed March 2014 The Advanced Microgrid Integration and Interoperability Ward Bower, Ward Bower Innovations LLC Dan Ton, U.S. Department of Energy; Office of Electricity Delivery & Energy Reliability Ross Guttromson, Sandia National Laboratories Steve Glover, Sandia National Laboratories Jason Stamp, Sandia National Laboratories Dhruv Bhatnagar, Sandia National Laboratories Jim Reilly, Reilly Associates Prepared by Sandia National Laboratories

  13. EA-1978: Sand Creek Winds, McCone County, Montana

    Office of Energy Efficiency and Renewable Energy (EERE)

    Western Area Power Administration (Western) is preparing an EA to analyze the potential environmental impacts of the proposed Sand Creek Winds Project, a 75-MW wind farm between the towns of Circle and Wolf Point in McCone County, Montana. The proposed wind farm would interconnect to Western’s existing Wolf Point to Circle 115-kV transmission line approximately 18 miles north of Wolf Point.

  14. SANDIA REPORT SAND2014-3416 Unlimited Release

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

    SANDIA REPORT SAND2014-3416 Unlimited Release Printed April 2014 Safety, Codes and Standards for Hydrogen Installations: Hydrogen Fueling System Footprint Metric Development A.P. Harris, Daniel E. Dedrick, Chris LaFleur, Chris San Marchi Prepared by Sandia National Laboratories Albuquerque, New Mexico 87185 and Livermore, California 94550 Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin

  15. Heavy oil and tar sands recovery and upgrading: international technology

    SciTech Connect (OSTI)

    Schumacher, M.M.

    1982-01-01

    This book provides an in-depth assessment of international technology for the recovery and upgrading of heavy crude oil and tar sands. The technologies included are currently in use, under development, or planned; emphasis is placed on post-1978 activities. The heavy oil technologies and processes considered in Part I include methods relating to the exploitation of heavy oil reservoirs, such as production from undergorun workings, all types of improved or enhanced recovery, subsurface extraction, and well rate stimulation. Furthermore, even though heavy crudes are understood to include only those liquid or semiliquid hydrocarbons with a gravity of 20/sup 0/API or less, technology applied to lighter crude oils with in situ viscosities of the same order of magnitude as some US heavy oils is also included. The scope of the tar sands section (Part II) includes sizing the resource base and reviewing and evaluatin past, present, and planned research and field developments on processes for mining, producing, extracting, and upgrading very heavy oils recovered from tar sands, e.g., bitumen recovery from tar sands where primary production was impossible because of the oil's high viscosity. On the production side, very heavy oil is defined as having a gravity less than 10/sup 0/ to 12/sup 0/API and greater than 100,000-centipoise viscosity at 50/sup 0/F. On the upgrading side, hydrocarbons whose characteristics dictated additional processing prior to conventional refining into salable products (1050+/sup 0/ material) were included, regardless of origin, in order to encompass all pertinent upgrading technologies.

  16. Numerical solution of sand transport in hydraulic fracturing

    SciTech Connect (OSTI)

    Daneshy, A.A.; Crichlow, H.B.

    1980-02-07

    A numerical solution is developed for the deposition of a propping agent inside a hydraulic fracture. Such parameters as fluid leak-off into the formation, increase in sand concentration caused by leak-off, non-Newtonian fracturing fluids, hindered settling velocity, and an up-to-date geometry are taken into consideration. Three examples investigate the proppant deposition for low-, medium-, and high-viscosity fracturing fluids.

  17. High resolution evaluation techniques in thinly laminated shaly sands

    SciTech Connect (OSTI)

    Coll, C.; Chacartegui, F.; Suarez, O.; Alvarez, G. ); Monsegui, G.; Lambertini, R.; Haines, P. )

    1993-02-01

    Significant hydrocarbon production may occur from thin layers which were previously considered non-economic. Improved processing methods for detecting and evaluating thin beds have shown these reservoirs to be attractive prospects. Such thinly bedded laminated shale-sand sequences exist within some of the producing formations in Venezuela. These shale sand packages may contain significant bypassed or undeveloped reserves. A new technique using deconvolution of the deep resistivity through the microresistivity curves (Microlog) identifies potential thinly bedded reservoirs. This methodology appears to be the most reliable permeability indicator of the prospective intervals within the Misoa Formation at Ceuta Field in Maracaibo Lake. The prospective intervals within this field have been calibrated with cores and with sedimentological information. This calibration shows only two lithofacies contained hydrocarbons previously not evaluated as oil saturated by traditional methods. These facies exhibited low values for deep resistivity curves which indicated high levels of water saturation. Deep resistivity deconvolution processing has been successfully applied to solve this problem in the Ceuta field. The resulting resistivity curve exhibits a vertical resolution of better than 1 ft., while retaining the essential advantages of deep resistivity curve. Laminated sand analyses were carried out and prove to be very useful in the integration of petrophysical and sedimentological data for detection of prospective intervals.

  18. Insulation from basaltic stamp sand. Final technical report

    SciTech Connect (OSTI)

    Williams, F. D.

    1981-04-01

    A Midwest Appropriate Technology Grant was awarded to determine the technical and economic feasibility of producing mineral-fiber insulation directly from extensive deposits of basaltic sand produced during former mining and milling operations in the Keweenaw Peninsula region of Michigan's Upper Peninsula. The amounts of local basaltic sands available and representative chemical compositions were determined. The variation of viscosity with temperature and chemical composition was estimated. Samples were melted and either pulled or blown into fiber. In all cases fiber could be made with a reasonable tensile strength to ensure usefulness. It was concluded that it was technically feasible to produce fibers from basaltic stamp sands of the Upper Peninsula of Michigan. A technical feasibility study using published data, a cost and design analysis of a basalt fiber production plant, a market survey of fiber needs, and an economic analysis for investing in a basalt fiber venture was undertaken. These studies concluded that the local production of basaltic insulation was both feasible and economically reasonable. It was suggested that the plant be located in a region of greater population density with lower utility costs. A representative one-third of these studies is included as appendices A, B, C, and D.

  19. Angle Resolved Thermal Conductivity of CeCoIn5 along the Nodal...

    Office of Scientific and Technical Information (OSTI)

    Angle Resolved Thermal Conductivity of CeCoIn5 along the Nodal Direction Citation Details In-Document Search Title: Angle Resolved Thermal Conductivity of CeCoIn5 along the Nodal ...

  20. Effect of Sodium on the Catalytic Properties of VOx/CeO2 Catalysts...

    Office of Scientific and Technical Information (OSTI)

    addition greatly alters the nature of the active sites by V-O-Ce bond cleavage and V-O-Na bond formation, leading to significantly reduced activity of the VOxCeO2 catalysts. ...

  1. Investigation of the physical properties of the tetragonal CeMAl4Si2...

    Office of Scientific and Technical Information (OSTI)

    the tetragonal CeMAl4Si2 (M Rh, Ir, Pt) compounds Prev Next Title: Investigation of the physical properties of the tetragonal CeMAl4Si2 (M Rh, Ir, Pt) compounds The ...

  2. NMR studies of field induced magnetism in CeCoIn5 (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: NMR studies of field induced magnetism in CeCoIn5 Citation Details In-Document Search Title: NMR studies of field induced magnetism in CeCoIn5 You are accessing ...

  3. DOI-BLM-ID-110-2009-3825-CE | Open Energy Information

    Open Energy Info (EERE)

    110-2009-3825-CE Jump to: navigation, search NEPA Document Collection for: DOI-BLM-ID-110-2009-3825-CE CX at Crane Creek Geothermal Area for GeothermalExploration Crane Creek...

  4. SEMI-ANNUAL REPORTS FOR CE FLNG, LLC (CAMBRIDGE) - DK. NO. 12...

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

    CE FLNG, LLC (CAMBRIDGE) - DK. NO. 12-123-LNG - ORDER 3193 SEMI-ANNUAL REPORTS FOR CE FLNG, LLC (CAMBRIDGE) - DK. NO. 12-123-LNG - ORDER 3193 PDF icon April 2013 PDF icon October...

  5. Evaluation of production samples of the scintillators LaBr3:Ce andLaCl3:Ce

    SciTech Connect (OSTI)

    Choong, Woon-Seng; Derenzo, Stephen E.; Moses, William W.

    2005-09-15

    We report on the evaluation of the performance of two recently developed scintillator materials, LaCl{sub 3}:Ce and LaBr{sub 3}:Ce, at the task of gamma ray spectroscopy. Their performance is compared to a standard scintillator used for gamma ray spectroscopy--a 25 mm diameter 25 mm tall cylinder of NaI:Tl. We measure the pulse height, energy resolution, and full-energy efficiency of production LaBr{sub 3}:Ce and LaCl{sub 3}:Ce scintillation crystals of different sizes and geometries for a variety of gamma-ray energies. Using production rather than specially selected crystals will establish whether immediate large-scale use is feasible. The crystal is excited by gamma rays from one of six isotopic sources ({sup 125}I, {sup 241}Am, {sup 57}Co, {sup 22}Na, {sup 137}Cs, and {sup 60}Co) placed 15 cm away from the scintillator. Our measurements show that both LaCl{sub 3} and LaBr{sub 3} outperform NaI:Tl in almost all cases. They outperform NaI:Tl at all energies for the photopeak fraction and counting rate measurements, and for energy resolution at higher energies (above 200 keV for LaCl{sub 3} and 75 keV for LaBr{sub 3}). The performance of production crystals is excellent and these scintillators should be considered for immediate use in systems where stopping power and energy resolution are crucial.

  6. Neutron scattering of CeNi at the SNS-ORNL: A preliminary report

    SciTech Connect (OSTI)

    Mirmelstein, A. [Russian Federal Nuclear Center VNIITF, Snezhinsk, Russia; Podlesnyak, Andrey A [ORNL; Kolesnikov, Alexander I [ORNL; Saporov, B. [Oak Ridge National Laboratory (ORNL); Sefat, A.S. [Oak Ridge National Laboratory (ORNL); Tobin, J. G. [Lawrence Livermore National Laboratory (LLNL)

    2014-01-01

    This is a preliminary report of a neutron scattering experiment used to investigate 4f electron behavior in Ce.

  7. CO Oxidation mechanism on CeO2-supported Au nanoclusters

    SciTech Connect (OSTI)

    Kim H. Y.; Henkelman, G.

    2013-09-08

    To reveal the richer chemistry of CO oxidation by CeO2 supported Au Nanoclusters(NCs)/Nanoparticles, we design Au13 and Au12 supported on a flat and a stepped-CeO2 model (Au/CeO2) and study various kinds of CO oxidation mechanisms at the Au-CeO2 interface and the Au NC as well.

  8. The extraction of bitumen from western oil sands: Volume 1. Final report

    SciTech Connect (OSTI)

    Oblad, A.G.; Dahlstrom, D.A.; Deo, M.D.; Fletcher, J.V.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1997-11-26

    The program is composed of 20 projects, of which 17 are laboratory bench or laboratory pilot scale processes or computer process simulations that are performed in existing facilities on the University of Utah campus in north-east Salt Lake City. These tasks are: (1) coupled fluidized-bed bitumen recovery and coked sand combustion; (2) water-based recovery of bitumen; (3) oil sand pyrolysis in a continuous rotary kiln reactor; (4) oil sand pyrolysis in a large diameter fluidized bed reactor; (5) oil sand pyrolysis in a small diameter fluidized bed reactor; (6) combustion of spent sand in a transport reactor; (7) recovery and upgrading of oil sand bitumen using solvent extraction methods; (8) fixed-bed hydrotreating of Uinta Basin bitumens and bitumen-derived hydrocarbon liquids; (9) ebullieted bed hydrotreating of bitumen and bitumen derived liquids; (10) bitumen upgrading by hydropyrolysis; (11) evaluation of Utah`s major oil sand deposits for the production of asphalt, high-energy jet fuels and other specialty products; (12) characterization of the bitumens and reservoir rocks from the Uinta Basin oil sand deposits; (13) bitumen upgrading pilot plant recommendations; (14) liquid-solid separation and fine tailings thickening; (15) in-situ production of heavy oil from Uinta Basin oil sand deposits; (16) oil sand research and development group analytical facility; and (17) process economics. This volume contains an executive summary and reports for five of these projects. 137 figs., 49 tabs.

  9. The extraction of bitumen from western oil sands: Volume 2. Final report

    SciTech Connect (OSTI)

    Oblad, A.G.; Dahlstrom, D.A.; Deo, M.D.; Fletcher, J.V.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1997-11-26

    The program is composed of 20 projects, of which 17 are laboratory bench or laboratory pilot scale processes or computer process simulations that are performed in existing facilities on the University of Utah campus in north-east Salt Lake City. These tasks are: (1) coupled fluidized-bed bitumen recovery and coked sand combustion; (2) water-based recovery of bitumen; (3) oil sand pyrolysis in a continuous rotary kiln reactor; (4) oil sand pyrolysis in a large diameter fluidized bed reactor; (5) oil sand pyrolysis in a small diameter fluidized bed reactor; (6) combustion of spent sand in a transport reactor; (7) recovery and upgrading of oil sand bitumen using solvent extraction methods; (8) fixed-bed hydrotreating of Uinta Basin bitumens and bitumen-derived hydrocarbon liquids; (9) ebullieted bed hydrotreating of bitumen and bitumen derived liquids; (10) bitumen upgrading by hydropyrolysis; (11) evaluation of Utah`s major oil sand deposits for the production of asphalt, high-energy jet fuels and other specialty products; (12) characterization of the bitumens and reservoir rocks from the Uinta Basin oil sand deposits; (13) bitumen upgrading pilot plant recommendations; (14) liquid-solid separation and fine tailings thickening; (15) in-situ production of heavy oil from Uinta Basin oil sand deposits; (16) oil sand research and development group analytical facility; and (17) process economics. This volume contains reports on nine of these projects, references, and a bibliography. 351 refs., 192 figs., 65 tabs.

  10. Assessment of the KE Basin Sand Filter Inventory In Support of Hazard Categorization

    SciTech Connect (OSTI)

    Ross, Steven B.; Young, Jonathan

    2005-09-28

    In 1978, the water cleaning system for the KE Basin was upgraded by adding a sand filter and ion exchange columns. Basin water containing finely divided solids is collected by three surface skimmers and pumped to the sand filter. Filtrate from the sand filter is further treated in the ion exchange modules. The suspended solids accumulate in the sand until the pressure drop across the filter reaches established operating limits, at which time the sand filter is backwashed. The backwash is collected in the NLOP, where the solids are allowed to settle as sludge. Figure 2-1 shows a basic piping and instrumentation diagram depicting the relationship among the basin skimmers, sand filter, and NLOP. During the course of deactivation and decommissioning (D&D) of the K-Basins, the sand filter and its media will need to be dispositioned. The isotopic distribution of the sludge in the sand filter has been estimated in KE Basin Sand Filter Monolith DQO (KBC-24705). This document estimates the sand filter contribution to the KE hazard categorization using the data from the DQO.

  11. Lattice Disorder and Size-Induced Kondo Behavior in CeAl{sub 2} and CePt{sub 2+x}

    SciTech Connect (OSTI)

    Han, S.-W.; Booth, C. H.; Bauer, E. D.; Huang, P. H.; Chen, Y. Y.; Lawrence, J. M.

    2006-09-01

    When the size of CeAl{sub 2} and CePt{sub 2+x} particles is reduced to the nanometer scale, antiferromagnetism is suppressed and Kondo behavior predominates, with the Kondo temperature T{sub K} either decreasing (CeAl{sub 2}) or increasing (CePt{sub 2+x}) relative to the bulk. Local structure measurements show that these nanoparticles are significantly distorted. While such distortions should strongly affect magnetic and electronic properties, we find they cannot explain the observed changes in T{sub K}. Other size-induced changes to the electronic structure must, therefore, play a significant role.

  12. Thermoelectric Couple Demonstration of (In, Ce)-based Skutterudite

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

    Powered Vehicle | Department of Energy Presentation given at the 16th Directions in Engine-Efficiency and Emissions Research (DEER) Conference in Detroit, MI, September 27-30, 2010. deer10_schock.pdf (2.44 MB) More Documents & Publications Thermoelectric Conversion of Waste Materials for Automotive Energy Recovery | Department of Energy

    Presents recent accomplishments and couple test results with these (In, Ce)-based skutterudite TE materials and potential impacts TE power system

  13. Renewable Energy Opportunities at White Sands Missile Range, New Mexico

    SciTech Connect (OSTI)

    Chvala, William D.; Solana, Amy E.; States, Jennifer C.; Warwick, William M.; Weimar, Mark R.; Dixon, Douglas R.

    2008-09-01

    The document provides an overview of renewable resource potential at White Sands Missile Range (WSMR) based primarily upon analysis of secondary data sources supplemented with limited on-site evaluations. The effort was funded by the U.S. Army Installation Management Command (IMCOM) as follow-on to the 2005 DoD Renewable Energy Assessment. This effort focuses on grid-connected generation of electricity from renewable energy sources and also ground source heat pumps (GSHPs) for heating and cooling buildings, as directed by IMCOM.

  14. User`s manual for SNL-SAND-II code

    SciTech Connect (OSTI)

    Griffin, P.J.; Kelly, J.G.; VanDenburg, J.W.

    1994-04-01

    Sandia National Laboratories, in the process of characterizing the neutron environments at its reactor facilities, has developed an enhanced version of W. McElroy`s original SAND-II code. The enhanced input, output, and plotting interfaces make the code much easier to use. The basic physics and operation of the code remain unchanged. Important code enhancements include the interfaces to the latest ENDF/B-VI and IRDF-90 dosimetry-quality cross sections and the ability to use silicon displacement-sensitive devices as dosimetry sensors.

  15. Production from multiple zones of a tar sands formation

    DOE Patents [OSTI]

    Karanikas, John Michael; Vinegar, Harold J

    2013-02-26

    A method for treating a tar sands formation includes providing heat to at least part of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. The heat is allowed to transfer from the heaters to at least a portion of the formation. Fluids are produced from the formation through at least one production well that is located in at least two zones in the formation. The first zone has an initial permeability of at least 1 darcy. The second zone has an initial of at most 0.1 darcy. The two zones are separated by a substantially impermeable barrier.

  16. Systems and methods for producing hydrocarbons from tar sands formations

    DOE Patents [OSTI]

    Li, Ruijian; Karanikas, John Michael

    2009-07-21

    A system for treating a tar sands formation is disclosed. A plurality of heaters are located in the formation. The heaters include at least partially horizontal heating sections at least partially in a hydrocarbon layer of the formation. The heating sections are at least partially arranged in a pattern in the hydrocarbon layer. The heaters are configured to provide heat to the hydrocarbon layer. The provided heat creates a plurality of drainage paths for mobilized fluids. At least two of the drainage paths converge. A production well is located to collect and produce mobilized fluids from at least one of the converged drainage paths in the hydrocarbon layer.

  17. Preliminary examination of oil bonding at sand surfaces and its influence on hot water separation

    SciTech Connect (OSTI)

    Hupka, J.; Budzich, M.; Miller, J.D.

    1991-01-01

    The efficiency of water-based separation of oil from sand particles is dependent on the nature of the oil-sand association and a preliminary examination of this bonding has been completed. The degree of hydration of the sand surface at the time of contact with oil was related to the subsequent efficiency of the oil-sand separation process. Variables which influence hot water separation were correlated by multiple linear regression, and a second order experimental model was obtained. The processing temperature appeared to be the most significant variable, followed by digestion time and pH. Oil-coated sand particles which had intrinsic water left on their surface during sample preparation were easily processed in hot water separation experiments, and 64 to 90% of the oil was removed. On the other hand, only 1 to 23% separation and oil recovery was possible when a calcinated sand-oil mixture was used.

  18. Preliminary examination of oil bonding at sand surfaces and its influence on hot water separation

    SciTech Connect (OSTI)

    Hupka, J.; Budzich, M.; Miller, J.D.

    1991-12-31

    The efficiency of water-based separation of oil from sand particles is dependent on the nature of the oil-sand association and a preliminary examination of this bonding has been completed. The degree of hydration of the sand surface at the time of contact with oil was related to the subsequent efficiency of the oil-sand separation process. Variables which influence hot water separation were correlated by multiple linear regression, and a second order experimental model was obtained. The processing temperature appeared to be the most significant variable, followed by digestion time and pH. Oil-coated sand particles which had intrinsic water left on their surface during sample preparation were easily processed in hot water separation experiments, and 64 to 90% of the oil was removed. On the other hand, only 1 to 23% separation and oil recovery was possible when a calcinated sand-oil mixture was used.

  19. Sand transport and deposition in horizontal multiphase trunklines of subsea satellite developments

    SciTech Connect (OSTI)

    Oudeman, P. )

    1993-11-01

    Gravel packing is unattractive as a way to protect against the effects of sand production in subsea wells because it involves additional completion costs, loss of productivity, and difficulties in subsequent recompletion/well servicing operations. On the other hand, omitting gravel packs means that subsea developments must be designed and operated so that they can tolerate sand production. An experimental study was carried out on sand transport and deposition in multiphase flow in modeled subsea flowlines to address the problem and sand collection in horizontal trunklines, which could lead to reduced line throughput, pigging problems, enhanced pipe-bottom erosion, or even blockage. This study led to the definition of a new model for sand transport in multiphase flow, which was used to establish the risk of sand deposition in trunklines connecting a subsea development to nearby production platform.

  20. Appraisal of the tight sands potential of the Sand Wash and Great Divide Basins. Final report, June 1989--June 1991

    SciTech Connect (OSTI)

    Not Available

    1993-08-01

    The volume of future tight gas reserve additions is difficult to estimate because of uncertainties in the characterization and extent of the resource and the performance and cost-effectiveness of stimulation and production technologies. Ongoing R&D by industry and government aims to reduce the risks and costs of producing these tight resources, increase the certainty of knowledge of their geologic characteristics and extent, and increase the efficiency of production technologies. Some basins expected to contain large volumes of tight gas are being evaluated as to their potential contribution to domestic gas supplies. This report describes the results of one such appraisal. This analysis addresses the tight portions of the Eastern Greater Green River Basin (Sand Wash and Great Divide Subbasins in Northwestern Colorado and Southwestern Wyoming, respectively), with respect to estimated gas-in-place, technical recovery, and potential reserves. Geological data were compiled from public and proprietary sources. The study estimated gas-in-place in significant (greater than 10 feet net sand thickness) tight sand intervals for six distinct vertical and 21 areal units of analysis. These units of analysis represent tight gas potential outside current areas of development. For each unit of analysis, a ``typical`` well was modeled to represent the costs, recovery and economics of near-term drilling prospects in that unit. Technically recoverable gas was calculated using reservoir properties and assumptions about current formation evaluation and extraction technology performance. Basin-specific capital and operating costs were incorporated along with taxes, royalties and current regulations to estimate the minimum required wellhead gas price required to make the typical well in each of unit of analysis economic.

  1. Determining sand-body geometries for waterflood reservoirs: Examples from Oklahoma

    SciTech Connect (OSTI)

    Kreisa, R.D.; Pinero, E. )

    1987-02-01

    Waterflood projects require an accurate knowledge of reservoir geometry and well-to-well continuity. However, sandstones with thin, multiple-pay zones can be extremely difficult to correlate with confidence. Two case studies of Pennsylvanian sandstones in Oklahoma illustrate how a model for the depositional history of such reservoirs can be an effective tool for determining reservoir continuity. In contrast, correlation criteria such as similar wireline log signatures and relative sand-body thicknesses are not reliable in many situations. In Southwest Logan field (Beaver County), 5 to 15-ft thick reservoir sands formed as shallow marine sand ridges. Their dimensions were approximated from height-to-width ratios of modern sand ridges. Then the reservoir sands were mapped using wireline logs and core data. Individual reservoir sands were approximately 1-2 km wide and stacked en echelon vertically. Thus, a line-drive waterflood pattern oriented parallel to the axes of the ridges is recommended. Tatums field (Carter County) consists of 5 to 50-ft thick sandstones deposited in various deltaic environments. Distributary channel sands have good continuity downdip, but are narrow and lenticular across depositional strike. Crevasse splay and other bay-fill sands were deposited marginal to the channels and are extremely discontinuous. This depositional model can be used to improve flood patterns for these sands, leading to improved sweep efficiency. In both examples, for effective mapping, the depositional facies models have been used to register reservoir quality and wireline log signatures.

  2. Non-Incineration Treatment to Reduce Benzene and VOC Emissions from Green Sand Molding Systems

    SciTech Connect (OSTI)

    Fred S. Cannon; Robert C. Voigt

    2002-06-28

    Final report describing laboratory, pilot scale and production scale evaluation of advanced oxidation systems for emissions and cost reduction in metal casting green sand systems.

  3. Preparation and thermochromic properties of Ce-doped VO{sub 2} films

    SciTech Connect (OSTI)

    Song, Linwei; Zhang, Yubo; Huang, Wanxia; Shi, Qiwu; Li, Danxia; Zhang, Yang; Xu, Yuanjie

    2013-06-01

    Graphical abstract: This effect of doping concentration on the phase transition temperature of VO{sub 2} films demonstrates that the phase transition temperature is decreasing along with the increase of the Ce dopant concentrations. After doping Ce, the transition temperature of VO{sub 2} film changes appreciably. Highlights: ► Ce-doped VO{sub 2} films were prepared on muscovite substrate by inorganic sol–gel method for the first time. ► The cerium existing in the VO{sub 2} films in the form of Ce{sup 4+} and Ce{sup 3+} was substituted for part of V atoms in the lattice. ► Ce doping could remarkably reduce the particle size of the Ce-doped films compared with undoped films. ► The phase transition temperature of Ce-doped VO{sub 2} films decreased appreciably with maintaining high-quality phase transition. - Abstract: Mixture of cerium (III) nitrate hexahydrate and vanadium pentaoxide powder were used as precursor to prepare Ce-doped VO{sub 2} films on the muscovite substrate by inorganic sol–gel method. SEM, XRD and XPS were used to investigate the morphologies and structures of VO{sub 2} films. The results show that the VO{sub 2} films grow on the muscovite substrate with preferred orientated (0 1 1) plane and the Ce exists in the form of Ce{sup 4+} and Ce{sup 3+} replacing part of V atoms in the lattice. The infrared transmittance change was measured from room temperature to the temperature above the metal–insulator transition. The films have excellent thermochromic performance. The metal–insulator transition temperature of VO{sub 2} films changes appreciably with Ce doped, which decreases by 4.5 °C per 1 at.% doping. Furthermore, Ce doping could remarkably reduce the particle size of VO{sub 2} films.

  4. Evaluation of water saturation in oil-bearing shaly sands

    SciTech Connect (OSTI)

    Martinovic, S.; Vojnovic, V. )

    1990-06-01

    The physical properties of shaly formations are difficult to evaluate because the shale component strongly affects geophysical well log and laboratory test data. This is particularly true in the case of water saturation. On the other hand, the accuracy of in-situ hydrocarbon estimates depends directly on the accuracy of water saturation values. The most important interpretation models for water saturation rely on double-layer models. These interpretation models compute highly probably water saturation values of oil-bearing shaly sands using sound mathematical and physical postulates. Certain disadvantages, such as the inability to evaluate some crucial parameters directly from geophysical well logs, simplifications along the system-model line, inherent deficiencies of logging techniques, etc., give rise to errors and other problems which are more or less solved at this stage of development. A simple program for water saturation of oil-bearing shaly sands was designed and tested. The program uses equations based on double layer models. Program listing and test results also are presented.

  5. Geology and resources of the Tar Sand Triangle, southeastern Utah

    SciTech Connect (OSTI)

    Dana, G.F.; Oliver, R.L.; Elliott, J.R.

    1984-05-01

    The Tar Sand Triangle is located in southeastern Utah between the Dirty Devil and Colorado Rivers and covers an area of about 200 square miles. The geology of the area consists of gently northwest dipping strata exposed in the box canyons and slopes of the canyonlands morphology. Strata in the area range in age from Jurassic to Permian. The majority of tar sand saturation is found in the Permian White Rim Sandstone Member of the Cutler Formation. The White Rim Sandstone Member consists of a clean, well-sorted sandstone which was deposited in a shallow marine environment. Resources were calculated from analytical data from the three coreholes drilled by the Laramie Energy Technology Center and other available data. The total in-place resources, determined from this study, are 6.3 billion barels. Previous estimates ranged from 2.9 to 16 million barrels. More coring and analyses will be necessary before a more accurate determination of resources can be attempted. 8 references, 11 figures, 7 tables.

  6. On the heat capacity of Ce{sub 3}Al

    SciTech Connect (OSTI)

    Singh, Durgesh Samatham, S. Shanmukharao Venkateshwarlu, D. Gangrade, Mohan Ganesan, V.

    2014-04-24

    Electrical resistivity and heat capacity measurements on Cerium based dense Kondo compound Ce{sub 3}Al have been reported. Clear signatures of first order structural transition at 108K, followed by a Kondo minimum and coherence are clearly seen in resistivity. The structural transition is robust and is not affected by magnetic fields. Heat capacity measurements reveal an anomalous enhancement in the heavy fermion character upon magnetic fields. Vollhardt invariance in specific heat C(T.H) curves have been observed at T=3.7K and at H ≈ 6T.

  7. Guide to Preparing SAND Reports and other communication products : quick reference guide.

    SciTech Connect (OSTI)

    Not Available

    2009-10-01

    This Quick Reference Guide supplements the more complete Guide to Preparing SAND Reports and Other Communication Products. It provides limited guidance on how to prepare SAND Reports at Sandia National Laboratories. Users are directed to the in-depth guide for explanations of processes.

  8. Wastewater treatment by sand filtration. (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect (OSTI)

    Not Available

    1993-09-01

    The bibliography contains citations concerning the use of sand filtration in the treatment of wastewaters. Treatment systems for both domestic and industrial effluents are discussed. Designs, processes, and performance evaluations of sand filters, columns, and mounds used as primary filtering mechanisms are included. (Contains a minimum of 244 citations and includes a subject term index and title list.)

  9. Wastewater treatment by sand filtration. (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect (OSTI)

    Not Available

    1994-04-01

    The bibliography contains citations concerning the use of sand filtration in the treatment of wastewaters. Systems and filtration processes for municipal, domestic, and industrial wastewater treatment are discussed. Designs and performance evaluations of sand filters are included. (Contains a minimum of 247 citations and includes a subject term index and title list.)

  10. Centrifuge modeling of LNAPL transport in partially saturated sand

    SciTech Connect (OSTI)

    Esposito, G.; Allersma, H.G.B.; Selvadurai, A.P.S.

    1999-12-01

    Model tests were performed at the Geotechnical Centrifuge Facility of Delft University of Technology, The Netherlands, to examine the mechanics of light nonaqueous phase liquid (LNAPL) movement in a partially saturated porous granular medium. The experiment simulated a 2D spill of LNAPL in an unsaturated sand prepared at two values of porosity. The duration of the centrifuge model tests corresponded to a prototype equivalent of 110 days. The choice of modeling a 2D flow together with the use of a transparent container enabled direct visual observation of the experiments. Scaling laws developed in connection with other centrifuge modeling studies were used to support the test results. Tests were conducted at two different centrifuge accelerations to verify, by means of the modeling of models technique, the similitude between the different experiments. The paper presents details of the experimental methodologies and the measuring techniques used to evaluate the final distribution of water and LNAPL content in the soils.

  11. Design of a sand filter for stormwater quality enhancement

    SciTech Connect (OSTI)

    Urbonas, B.R.

    1999-01-01

    The use of sand and other media filters is gaining acceptance in the field of urban stormwater structural best management practice. Much work has been done to develop local design guidance, such as in the State of Delaware and in Austin, Texas. Also, considerable field testing of these devices has occurred during the last 10 years. This paper consolidates much of the earlier work and provides the technical basis for the design of media filters for stormwater runoff treatment at any location in the US. The approach uses the unit processes known to exist in urban stormwater runoff and within filter devices. The suggested design is based on hydraulic capacity of the filter media, which, in turn, is a function of the total suspended particulates removed by the filter.

  12. Preliminary relative permeability estimates of methanehydrate-bearing sand

    SciTech Connect (OSTI)

    Seol, Yongkoo; Kneafsey, Timothy J.; Tomutsa, Liviu; Moridis,George J.

    2006-05-08

    The relative permeability to fluids in hydrate-bearingsediments is an important parameter for predicting natural gas productionfrom gas hydrate reservoirs. We estimated the relative permeabilityparameters (van Genuchten alpha and m) in a hydrate-bearing sand by meansof inverse modeling, which involved matching water saturation predictionswith observations from a controlled waterflood experiment. We used x-raycomputed tomography (CT) scanning to determine both the porosity and thehydrate and aqueous phase saturation distributions in the samples. X-rayCT images showed that hydrate and aqueous phase saturations arenon-uniform, and that water flow focuses in regions of lower hydratesaturation. The relative permeability parameters were estimated at twolocations in each sample. Differences between the estimated parametersets at the two locations were attributed to heterogeneity in the hydratesaturation. Better estimates of the relative permeability parametersrequire further refinement of the experimental design, and betterdescription of heterogeneity in the numerical inversions.

  13. Injury experience in sand and gravel mining, 1990

    SciTech Connect (OSTI)

    Not Available

    1991-12-31

    This Mine Safety and Health Administration (MSHA) informational report reviews in detail the occupational injury and illness experience of sand and gravel mining in the United States for 1990. Data reported by operators of mining establishments concerning work injuries are summarized by work location, accident classification, part of body injured, nature of injury, and occupation. Related information on employment, worktime, and operating activity also is presented. Data reported by independent contractors performing certain work at mining locations are depicted separately in this report. For ease of comparison with other metal and nonmetallic mineral mining industries and with coal mining, summary reference tabulations are included at the end of both the operator and the contractor sections of this report.

  14. Injury experience in sand and gravel mining, 1992

    SciTech Connect (OSTI)

    Reich, R.B.; Hugler, E.C.

    1994-05-01

    This Mine Safety and Health Administration (MSHA) informational report reviews in detail the occupational injury and illness experience of sand and gravel mining in the United States for 1992. Data reported by operators of mining establishments concerning work injuries are summarized by work location, accident classification, part of body injured, nature of injury, and occupation. Related information on employment, worktime, and operating activity also is presented. Data reported by independent contractors performing certain work at mining locations are depicted separately in this report. For ease of comparison with other metal and nonmetallic mineral mining industries and with coal mining, summary reference tabulations are included at the end of both the operator and the contractor sections of this report.

  15. Injury experience in sand and gravel mining, 1990

    SciTech Connect (OSTI)

    Not Available

    1991-01-01

    This Mine Safety and Health Administration (MSHA) informational report reviews in detail the occupational injury and illness experience of sand and gravel mining in the United States for 1990. Data reported by operators of mining establishments concerning work injuries are summarized by work location, accident classification, part of body injured, nature of injury, and occupation. Related information on employment, worktime, and operating activity also is presented. Data reported by independent contractors performing certain work at mining locations are depicted separately in this report. For ease of comparison with other metal and nonmetallic mineral mining industries and with coal mining, summary reference tabulations are included at the end of both the operator and the contractor sections of this report.

  16. Injury experience in sand and gravel mining, 1989

    SciTech Connect (OSTI)

    Not Available

    1990-01-01

    This Mine Safety and Health Administration (MSHA) informational report reviews in detail the occupational injury and illness experience of sand and gravel mining in the United States for 1989. Data reported by operators of mining establishments concerning work injuries are summarized by work location, accident classification, part of body injured, nature of injury, and occupation. Related information on employment, worktime, and operating activity also is presented. Data reported by independent contractors performing certain work at mining locations are depicted separately in this report. For ease of comparison with other metal and nonmetallic mineral mining industries and with coal mining, summary reference tabulations are included at the end of both the operator and the contractor sections of this report. 3 figs., 38 tabs.

  17. Preliminary relative permeability estimates of methanehydrate-bearing sand

    SciTech Connect (OSTI)

    Seol, Yongkoo; Kneafsey, Timothy J.; Tomutsa, Liviu; Moridis,George J.

    2006-05-08

    The relative permeability to fluids in hydrate-bearing sediments is an important parameter for predicting natural gas production from gas hydrate reservoirs. We estimated the relative permeability parameters (van Genuchten alpha and m) in a hydrate-bearing sand by means of inverse modeling, which involved matching water saturation predictions with observations from a controlled waterflood experiment. We used x-ray computed tomography (CT) scanning to determine both the porosity and the hydrate and aqueous phase saturation distributions in the samples. X-ray CT images showed that hydrate and aqueous phase saturations are non-uniform, and that water flow focuses in regions of lower hydrate saturation. The relative permeability parameters were estimated at two locations in each sample. Differences between the estimated parameter sets at the two locations were attributed to heterogeneity in the hydrate saturation. Better estimates of the relative permeability parameters require further refinement of the experimental design, and better description of heterogeneity in the numerical inversions.

  18. Injury experience in sand and gravel mining, 1991

    SciTech Connect (OSTI)

    Not Available

    1993-10-01

    This Mine Safety and Health Administration (MSHA) informational report reviews in detail the occupational injury and illness experience of sand and gravel mining in the United States for 1991. Data reported by operators of mining establishments concerning work injuries are summarized by work location, accident classification, part of body injured, nature of injury, and occupation. Related information on employment, worktime, and operating activity also is presented. Data reported by independent contractors performing certain work at mining locations are depicted separately in this report. For ease of comparison with other metal and nonmetallic mineral mining industries and with coal mining, summary reference tabulations are included at the end of both the operator and the contractor sections of this report.

  19. Measurement of Moisture Content in Sand, Slag, and Crucible Materials

    SciTech Connect (OSTI)

    Gray, J.H.

    1999-09-20

    The deinventory process at Rocky Flats (RFETS) has included moisture content measurements of sand, slag, and crucible (SSC) materials by performing weight loss measurements at 210 degrees - 220 degrees Celsius on representative samples prior to packaging for shipment. Shipping requirements include knowledge of the moisture content. Work at the Savannah River Technology Center (SRTC) showed that the measurement at 210 degrees - 220 degrees Celsius did not account for all of the moisture. The objective of the work in this report was to determine if the measurement at 210 degrees - 220 degrees Celsius at RFETS could be used to set upper bounds on moisture content and therefore, eliminate the need for RFETS to unpack, reanalyze and repack the material.

  20. Magnetic properties and photoabsorption of the Mn-doped CeO{sub 2} nanorods

    SciTech Connect (OSTI)

    Xia, Chuanhui; Science College of Chongqing Jiaotong University, Chongqing 400074 ; Hu, Chenguo; Chen, Peng; Wan, Buyong; He, Xiaoshan; Tian, Yongshu; Chongqing Communication College, Chongqing 400035

    2010-07-15

    Mn-doped CeO{sub 2} nanorods have been prepared from CeO{sub 2} particles through a facile composite-hydroxide-mediated (CHM) approach. The analysis from X-ray photoelectron spectroscopy indicates that the manganese doped in CeO{sub 2} exists as Mn{sup 2+}. The magnetic measurement of the Mn-doped CeO{sub 2} nanorods exhibits an enhanced ferromagnetic property at room temperature with a remanence magnetization (Mr) of 1.36 x 10{sup -3} emu/g and coercivity (Hc) of 22 Oe. Comparative UV-visible spectra reveal the shift of the absorption peak of the CeO{sub 2} from ultraviolet region to visible light region after being doped with Mn. The room temperature ferromagnetic properties and light absorption of the Mn-doped CeO{sub 2} nanorods would have potential applications in photocatalysis and building of photovoltaic devices.

  1. The influence of nano-architectured CeOx supports in RhPd/CeO₂ for the catalytic ethanol steam reforming reaction

    SciTech Connect (OSTI)

    Divins, N. J.; Senanayake, S. D.; Casanovas, A.; Xu, W.; Trovarelli, A.; Llorca, J.

    2015-01-19

    The ethanol steam reforming (ESR) reaction has been tested over RhPd supported on polycrystalline ceria in comparison to structured supports composed of nanoshaped CeO₂ cubes and CeO₂ rods tailored towards the production of hydrogen. At 650-700 K the hydrogen yield follows the trend RhPd/CeO₂-cubes > RhPd/CeO₂ -rods > RhPd/CeO₂- polycrystalline, whereas at temperatures higher than 800 K the catalytic performance of all samples is similar and close to the thermodynamic equilibrium. The improved performance of RhPd/CeO₂-cubes and RhPd/CeO₂ -rods for ESR at low temperature is mainly ascribed to higher water-gas shift activity and a strong interaction between the bimetallic - oxide support interaction. STEM analysis shows the existence of RhPd alloyed nanoparticles in all samples, with no apparent relationship between ESR performance and RhPd particle size. X-ray diffraction under operating conditions shows metal reorganization on {100} and {110} ceria crystallographic planes during catalyst activation and ESR, but not on {111} ceria crystallographic planes. The RhPd reconstructing and tuned activation over ceria nanocubes and nanorods is considered the main reason for better catalytic activity with respect to conventional catalysts based on polycrystalline ceria

  2. The influence of nano-architectured CeOx supports in RhPd/CeO₂ for the catalytic ethanol steam reforming reaction

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

    Divins, N. J.; Senanayake, S. D.; Casanovas, A.; Xu, W.; Trovarelli, A.; Llorca, J.

    2015-01-19

    The ethanol steam reforming (ESR) reaction has been tested over RhPd supported on polycrystalline ceria in comparison to structured supports composed of nanoshaped CeO₂ cubes and CeO₂ rods tailored towards the production of hydrogen. At 650-700 K the hydrogen yield follows the trend RhPd/CeO₂-cubes > RhPd/CeO₂ -rods > RhPd/CeO₂- polycrystalline, whereas at temperatures higher than 800 K the catalytic performance of all samples is similar and close to the thermodynamic equilibrium. The improved performance of RhPd/CeO₂-cubes and RhPd/CeO₂ -rods for ESR at low temperature is mainly ascribed to higher water-gas shift activity and a strong interaction between the bimetallic -more » oxide support interaction. STEM analysis shows the existence of RhPd alloyed nanoparticles in all samples, with no apparent relationship between ESR performance and RhPd particle size. X-ray diffraction under operating conditions shows metal reorganization on {100} and {110} ceria crystallographic planes during catalyst activation and ESR, but not on {111} ceria crystallographic planes. The RhPd reconstructing and tuned activation over ceria nanocubes and nanorods is considered the main reason for better catalytic activity with respect to conventional catalysts based on polycrystalline ceria« less

  3. Center for Excitonics (CE) | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    Center for Excitonics (CE) Energy Frontier Research Centers (EFRCs) EFRCs Home Centers EFRC External Websites Research Science Highlights News & Events Publications History Contact BES Home Centers Center for Excitonics (CE) Print Text Size: A A A FeedbackShare Page CE Header Director Marc Baldo Lead Institution Massachusetts Institute of Technology Year Established 2009 Mission To supersede traditional electronics with devices that use excitonics to mediate the flow of energy. Research

  4. Polymer treatments for D Sand water injection wells: Sooner D Sand Unit Weld County, Colorado. Final report, April 1997

    SciTech Connect (OSTI)

    Cannon, T.J.

    1998-10-01

    Polymer-gel treatments in injection wells were evaluated for improving sweep efficiency in the D Sandstone reservoir at the Sooner Unit, Weld County, Colorado. Polymer treatments of injection wells at the Sooner Unit were expected to improve ultimate recovery by 1.0 percent of original-oil-in-place of 70,000 bbl of oil. The Sooner D Sand Unit was a demonstration project under the US Department of Energy Class I Oil Program from which extensive reservoir data and characterization were obtained. Thus, successful application of polymer-gel treatments at the Sooner Unit would be a good case-history example for other operators of waterfloods in Cretaceous sandstone reservoirs in the Denver Basin.

  5. Proactive Design of n-Type (In, Ce) Filled Skutterudites Enabling...

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

    More Documents & Publications Proactive Design of n-Type (In, Ce) Filled Skutterudites Enabling High-Temperature Waste Heat Recovery Thermoelectric Couple Demonstration of (In, ...

  6. Ethanol Steam Reforming on Co/CeO2: The Effect of ZnO Promoter

    SciTech Connect (OSTI)

    Davidson, Stephen; Sun, Junming; Wang, Yong

    2013-12-02

    A series of ZnO promoted Co/CeO2 catalysts were synthesized and characterized using XRD, TEM, H2-TPR, CO chemisorption, O2-TPO, IR-Py, and CO2-TPD. The effects of ZnO on the catalytic performances of Co/CeO2 were studied in ethanol steam reforming. It was found that the addition of ZnO facilitated the oxidation of Co0 via enhanced oxygen mobility of the CeO2 support which decreased the activity of Co/CeO2 in C–C bond cleavage of ethanol. 3 wt% ZnO promoted Co/CeO2 exhibited minimum CO and CH4 selectivity and maximum CO2 selectivity. This resulted from the combined effects of the following factors with increasing ZnO loading: (1) enhanced oxygen mobility of CeO2 facilitated the oxidation of CHx and CO to form CO2; (2) increased ZnO coverage on CeO2 surface reduced the interaction between CHx/CO and Co/CeO2; and (3) suppressed CO adsorption on Co0 reduced CO oxidation rate to form CO2. In addition, the addition of ZnO also modified the surface acidity and basicity of CeO2, which consequently affected the C2–C4 product distributions.

  7. Luminescence properties of LaF{sub 3}:Ce nanoparticles encapsulated by oleic acid

    SciTech Connect (OSTI)

    Kim, Jaewoo; Lee, Jun-Hyung; An, Hyejin; Lee, Jungkuk; Park, Seong-Hee; Seo, Young-Soo; Miller, William H.

    2014-09-15

    Highlights: In-situ hydrophobization of water dispersible LaF{sub 3}:Ce nanoparticles was achieved. Oleic acid surface modification of the nanoparticles was verified by IR spectra. Quantum yields of LaF{sub 3}:Ce and OA-LaF{sub 3}:Ce nanoparticles were evaluated. Quantum yields of LaF{sub 3}:Ce are strongly dependent on OA surface modification. - Abstract: Cerium ions doped lanthanum fluoride (LaF{sub 3}:Ce) nanopowder as well as LaF{sub 3}:Ce nanopowder whose surfaces was modified by oleic acid (OA) were synthesized by using an in-situ hydrothermal process under the various doping concentrations. Based on the XRD spectra and TEM images, it was confirmed that the crystalline structured hexagonal LaF{sub 3}:Ce nanopowder was synthesized. Oleic acid was efficient for conversion of the water dispersible LaF{sub 3}:Ce nanoparticles to hydrophobic ones. Surface modification was verified by FTIR absorption spectrum as well as TEM images, showing no agglomeration between 5 and 10 nm scaled particles. Photoluminescence based on 5d ? 4f electronic transition of cerium ions excited at ?{sub ex} ?256 nm for both neat and OA encapsulated LaF{sub 3}:Ce nanoparticles decreases as the cerium concentration increases, while the quantum yields of OA encapsulated nanoparticles were much lower than the neat particles due to low photon transmittance of OA at the range longer than ?350 nm.

  8. Capillary electrophoresis-fluorescence line narrowing system (CE-FLNS) for on-line structural characterization

    DOE Patents [OSTI]

    Jankowiak, R.J.; Small, G.J.; Shields, P.A.

    1999-04-27

    Capillary electrophoresis (CE) is interfaced with low temperature fluorescence line-narrowing (FLN) spectroscopy for on-line structural characterization of separated molecular analytes. 21 figs.

  9. Capillary electrophoresis-fluorescence line narrowing system (CE-FLNS) for on-line structural characterization

    DOE Patents [OSTI]

    Jankowiak, Ryszard J.; Small, Gerald J.; Shields, Peter A.

    1999-04-27

    Capillary electrophoresis (CE) is interfaced with low temperature fluorescence line-narrowing (FLN) spectroscopy for on-line structural characterization of separated molecular analytes.

  10. Thermal Variation of Ce Valence in Mixed ValenceKondo Lattice Systems CeT2(Si1-xGex)2 with T= Mn and Ni

    SciTech Connect (OSTI)

    Liang,G.; Croft, M.

    2008-01-01

    The results on the thermal variation of Ce L3-valence in CeT2(Si1-xGex)2 series with 0{le}x{le}1 and T=Mn and Ni are reported. It is observed that for both series, the Ce valence increases with decreasing temperature and has little thermal variation for samples in the nearly trivalent regime. The magnitude of this thermal variation in the T=Mn series is much greater than in the T=Ni series. The results are explained by the degenerate Anderson model and correlated with the specific heat data.

  11. The record of sea level rise by tidal sand bodies of the English Channel

    SciTech Connect (OSTI)

    Berne, S; Lericolais, G. (Ifremer, Plouzane, (France)); Lafont, F. (Universite d'Orsay (France))

    1990-05-01

    Improvements of very high resolution seismic reflection provide new information about internal structures of modern sand bodies. This allows us to reconstruct their recent history, which is related to the Holocene sea level rise. A major distinction is found between inner shelf sand bodies, dominated by autocyclic processes, and outer shelf sand bodies, where allocyclic processes are invoked to explain the apparent contradiction between internal structures and present-day dynamics. On the inner shelf, evidence of the migration of tidal dunes (sand waves) has been obtained by repeated surveys using accurate positioning systems. Major bounding surfaces are thought to result from the action of tidal current and/or from episodic storms. A rough estimation of the age of these sand bodies can be proposed. On the outer shelf, some dunes of the English Channel exhibit cross-beds indicative of a past net bed-load transport at the opposite of present days dynamics, inherited from different tidal conditions when sea level was between 20 and 40 m lower. Some large tidal sand banks (e.g., the Sark Bank near the Channel Islands) display a more complicated pattern. The upper part of the sand bank is the result of the migration of very large dunes climbing at positive angles, whereas the lower part shows major erosional surfaces, attributed to the action of storms during lower sea levels.

  12. Magnetic structure of the antiferromagnetic Kondo lattice compounds CeRhAl4Si2 and CeIrAl4Si2

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

    Ghimire, N. J.; Calder, S.; Janoschek, M.; Bauer, E. D.

    2015-06-01

    In this article, we have investigated the magnetic ground state of the antiferromagnetic Kondo-lattice compounds CeMAl4Si2(M = Rh, Ir) using neutron powder diffraction. Although both of these compounds show two magnetic transitions TN1 and TN2 in the bulk properties measurements, evidence for magnetic long-range order was only found below the lower transition TN2. Analysis of the diffraction profiles reveals a commensurate antiferromagnetic structure with a propagation vector k = (0, 0, 1/2). The magnetic moment in the ordered state of CeRhAl4Si2 and CeIrAl4Si2 were determined to be 1.14(2) and 1.41(3) μB/Ce, respectively, and are parallel to the crystallographic c-axis inmore » agreement with magnetic susceptibility measurements.« less

  13. Excess Foundry Sand Characterization and Experimental Investigation in Controlled Low-Strength Material and Hot-Mixing Asphalt

    SciTech Connect (OSTI)

    Pauul J. Tikalsky

    2004-10-31

    This report provides technical data regarding the reuse of excess foundry sand. The report addresses three topics: (1) a statistically sound evaluation of the characterization of foundry sand, (2) a laboratory investigation to qualify excess foundry sand as a major component in controlled low-strength material (CLSM), and (3) the identification of the best methods for using foundry sand as a replacement for natural aggregates for construction purposes, specifically in asphalt paving materials. The survival analysis statistical technique was used to characterize foundry sand over a full spectrum of general chemical parameters, metallic elements, and organic compounds regarding bulk analysis and leachate characterization. Not limited to characterization and environmental impact, foundry sand was evaluated by factor analyses, which contributes to proper selection of factor and maximization of the reuse marketplace for foundry sand. Regarding the integration of foundry sand into CLSM, excavatable CLSM and structural CLSM containing different types of excess foundry sands were investigated through laboratory experiments. Foundry sand was approved to constitute a major component in CLSM. Regarding the integration of foundry sand into asphalt paving materials, the optimum asphalt content was determined for each mixture, as well as the bulk density, maximum density, asphalt absorption, and air voids at N{sub ini}, N{sub des}, and N{sub max}. It was found that foundry sands can be used as an aggregate in hot-mix asphalt production, but each sand should be evaluated individually. Foundry sands tend to lower the strength of mixtures and also may make them more susceptible to moisture damage. Finally, traditional anti-stripping additives may decrease the moisture sensitivity of a mixture containing foundry sand, but not to the level allowed by most highway agencies.

  14. Excess Foundry Sand Characterization and Experimental Investigation in Controlled Low-Strength Material and Hot-Mixing Asphalt

    SciTech Connect (OSTI)

    Tikalsky, Paul J.; Bahia, Hussain U.; Deng, An; Snyder, Thomas

    2004-10-15

    This report provides technical data regarding the reuse of excess foundry sand. The report addresses three topics: a statistically sound evaluation of the characterization of foundry sand, a laboratory investigation to qualify excess foundry sand as a major component in controlled low-strength material (CLSM), and the identification of the best methods for using foundry sand as a replacement for natural aggregates for construction purposes, specifically in asphalt paving materials. The survival analysis statistical technique was used to characterize foundry sand over a full spectrum of general chemical parameters, metallic elements, and organic compounds regarding bulk analysis and leachate characterization. Not limited to characterization and environmental impact, foundry sand was evaluated by factor analyses, which contributes to proper selection of factor and maximization of the reuse marketplace for foundry sand. Regarding the integration of foundry sand into CLSM, excavatable CLSM and structural CLSM containing different types of excess foundry sands were investigated through laboratory experiments. Foundry sand was approved to constitute a major component in CLSM. Regarding the integration of foundry sand into asphalt paving materials, the optimum asphalt content was determined for each mixture, as well as the bulk density, maximum density, asphalt absorption, and air voids at Nini, Ndes, and Nmax. It was found that foundry sands can be used as an aggregate in hot-mix asphalt production, but each sand should be evaluated individually. Foundry sands tend to lower the strength of mixtures and also may make them more susceptible to moisture damage. Finally, traditional anti-stripping additives may decrease the moisture sensitivity of a mixture containing foundry sand, but not to the level allowed by most highway agencies.

  15. Ternary ceramic alloys of Zr-Ce-Hf oxides

    DOE Patents [OSTI]

    Becher, P.F.; Funkenbusch, E.F.

    1990-11-20

    A ternary ceramic alloy is described which produces toughening of zirconia and zirconia composites through the stress transformation from tetragonal phase to monoclinic phase. This alloy, having the general formula Ce[sub x]Hf[sub y]Zr[sub 1[minus]x[minus]y]O[sub 2], is produced through the addition of appropriate amounts of ceria and hafnia to the zirconia. Typically, improved toughness is achieved with about 5 to about 15 mol % ceria and up to about 40 mol % hafnia. The preparation of alloys of these compositions are given together with data as to the densities, tetragonal phase content, hardness and fracture toughness. The alloys are useful in preparing zirconia bodies as well as reinforcing ceramic composites. 1 fig.

  16. Ternary ceramic alloys of ZR-CE-HF oxides

    DOE Patents [OSTI]

    Becher, Paul F.; Funkenbusch, Eric F.

    1990-01-01

    A ternary ceramic alloy which produces toughening of zirconia and zirconia composites through the stress transformation from tetragonal phase to monoclinic phase. This alloy, having the general formula Ce.sub.x Hf.sub.y Zn.sub.1-x-y O.sub.2, is produced through the addition of appropriate amounts of ceria and hafnia to the zirconia. Typically, improved toughness is achieved with about 5 to about 15 mol % ceria and up to about 40 mol % hafnia. The preparation of alloys of these compositions are given together with data as to the densities, tetragonal phase content, hardness and fracture toughness. The alloys are useful in preparing zirconia bodies as well as reinforcing ceramic composites.

  17. Inelastic magnetic neutron scattering in CePd{sub 3}.

    SciTech Connect (OSTI)

    Lawrence, J. M.; Fanelli, V. R.; Goremychkin, E. A.; Osborn, R.; Bauer, E. D.; McClellan, K. J.; Christianson, A. D.; Univ. of California at Irvine; LANL; ORNL

    2008-01-01

    We have performed time-of-flight neutron scattering measurements on a single crystal of the intermediate valence compound CePd{sub 3}. At 10 K, a Kondo-esque inelastic magnetic scattering peak occurs near {Delta}E = 60 meV with maximum intensity for momentum transfer Q near the (1/2, 1/2, 0) zone boundary. Spectral weight is transferred to lower energy as Q varies until at zone center the intensity at 60 meV is considerably weaker. These results are in qualitative accord with predictions of the Anderson lattice. The Q-dependence may resolve an older controversy concerning the low-temperature scattering. We discuss the relationship of these results to our recent results in YbAl{sub 3}.

  18. Preparation and properties of ce-doped TiO{sub 2} photocatalyst

    SciTech Connect (OSTI)

    Yan, Ningning; Zhu, Zhongqi; Zhang, Jin; Zhao, Zongyan; Liu, Qingju

    2012-08-15

    Highlights: ? The cerium ion doped TiO{sub 2} (Ce-TiO{sub 2}) powders were prepared and characterized. ? The spectrum absorption region of Ce-TiO{sub 2} is red-shifted to visible light. ? The recombination of photo-generated electron-hole pairs of Ce-TiO{sub 2} is inhibited. ? The photocatalytic activity was effected by Ce ion content and greatly improved. -- Abstract: TiO{sub 2} nanoparticles doped with different content of Ce ion were prepared by solgel method. The samples were characterized by XRD, XPS, TEM, UVVis, and PL, the photocatalytic activity was evaluated by photocatalytic degradation of methylene blue (MB) under the irradiation of fluorescent lamp. The results indicate that Ce ion is incorporated into the lattice of TiO{sub 2}, which can restrain the increase of grain size, broaden the absorption region to visible light, and inhibit the recombination of the photo-generated electron and hole pairs. Moreover, the photocatalytic activity of Ce-TiO{sub 2} in MB degradation is evidently enhanced. The MB degradation rate of the sample with Ce:Ti = 0.33% (molar ratio) in 8 h is 90.03%, which is much higher than that of P25 (68.19%).

  19. Ethanol Steam Reforming on Co/CeO2: The Effect of ZnO Promoter...

    Office of Scientific and Technical Information (OSTI)

    Ethanol Steam Reforming on CoCeO2: The Effect of ZnO Promoter Citation Details In-Document Search Title: Ethanol Steam Reforming on CoCeO2: The Effect of ZnO Promoter A series of ...

  20. Guide to preparing SAND reports and other communication products.

    SciTech Connect (OSTI)

    Not Available

    2011-09-01

    This guide describes the R&A process, Common Look and Feel requirements, and preparation and publishing procedures for communication products at Sandia National Laboratories. Samples of forms and examples of published communications products are provided. This guide takes advantage of the wealth of material now available on the Web as a resource. Therefore, it is best viewed as an electronic document. If some of the illustrations are too small to view comfortably, you can enlarge them on the screen as needed. The format of this document is considerably different than that usually expected of a SAND Report. It was selected to permit the large number of illustrations and examples to be placed closer to the text that references them. In the case of forms, covers, and other items that are included as examples, a link to the Web is provided so that you can access the items and download them for use. This guide details the processes for producing a variety of communication products at Sandia National Laboratories. Figure I-1 shows the general publication development process. Because extensive supplemental material is available from Sandia on the internal web or from external sources (Table I-1), the guide has been shortened to make it easy to find information that you need.

  1. CO Oxidation at the Interface of Au Nanoclusters and the Stepped-CeO2(111) Surface

    SciTech Connect (OSTI)

    Kim H. Y.; Henkelman, G.

    2013-01-14

    To reveal the richer chemistry of CO oxidation by CeO2 supported Au Nanoclusters NCs)/Nanoparticles, we design a Au12 supported on a stepped-CeO2 model (Au/CeO2-step) and study various kinds of CO oxidation mechanisms at the interface of the Au/CeO2-step: oxygen spillover from the CeO2 to the Au NCs;2 CO oxidation by the O2 bound to the Au-Ce3+ interface;3 and CO oxidation by the Mars-van Krevelen (M-vK) mechanism.4 DFT+U calculations show that lattice oxygen at the CeO2 step edge oxidizes CO bound to Au NCs by the M-vK mechanism. CO2 desorption determines the rate of CO oxidation and the vacancy formation energy (Evac) is a reactivity descriptor for CO oxidation. The maximum Evac that insures spontaneous CO2 production is higher for the Au/CeO2-step than the Au/CeO2-surface suggesting that the CeO2-step is a better supporting material than the CeO2-surface for CO oxidation by the Au/CeO2. Our results also suggest that for CO oxidation by Au NCs supported on nano- or meso-structured CeO2, which is the case of industrial catalysts, the M-vK mechanism accounts for a large portion of the total activity.

  2. High Curie temperature of Ce-Fe-Si compounds with ThMn12 structure

    SciTech Connect (OSTI)

    Zhou, C; Pinkerton, FE; Herbst, JF

    2015-01-15

    We report the discovery of ternary CeFe(12-x)Si(x)compounds possessing the ThMn12 structure. The samples were prepared by melt spinning followed by annealing. In contrast to other known Ce Fe-based binary and ternary compounds, CeFe12-xSix compounds exhibit exceptionally high Curie temperatures whose values increase with added Si substitution. The highest T. = 583 K in CeFe10Si2 rivals that of the well-established Nd2Fe14B compound. We ascribe the T-c behavior to a combination of Si-induced 3d band structure changes and partial Ce3+ stabilization. (C) 2014 Published by Elsevier Ltd.

  3. BETO-Funded Study Finds Increased Carbon Intensity from Canadian Oil Sands

    Office of Energy Efficiency and Renewable Energy (EERE)

    A recently released study from Argonne National Laboratory shows that gasoline and diesel refined from Canadian oil sands have a higher carbon impact than fuels derived from conventional domestic crude sources.

  4. Integration of High Temperature Gas-cooled Reactor Technology with Oil Sands Processes

    SciTech Connect (OSTI)

    L.E. Demick

    2011-10-01

    This paper summarizes an evaluation of siting an HTGR plant in a remote area supplying steam, electricity and high temperature gas for recovery and upgrading of unconventional crude oil from oil sands. The area selected for this evaluation is the Alberta Canada oil sands. This is a very fertile and active area for bitumen recovery and upgrading with significant quantities piped to refineries in Canada and the U.S Additionally data on the energy consumption and other factors that are required to complete the evaluation of HTGR application is readily available in the public domain. There is also interest by the Alberta oil sands producers (OSP) in identifying alternative energy sources for their operations. It should be noted, however, that the results of this evaluation could be applied to any similar oil sands area.

  5. APEX Workflows LANL, NERSC, SNL SAND2016-2371 O LA-UR-15-29113

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

    APEX Workflows LANL, NERSC, SNL SAND2016-2371 O LA-UR-15-29113 March 17, 2016 1 Introduction The Department of Energy (DOE) compute facilities operate as resources for the National ...

  6. EA-1978: Sand Creek Winds, McCone County, Montana | Department...

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

    analyze the potential environmental impacts of the proposed Sand Creek Winds Project, a 75-MW wind farm between the towns of Circle and Wolf Point in McCone County, Montana. The...

  7. Use of the dual-screen thru-tubing sand control method

    SciTech Connect (OSTI)

    Freiman, O.H.; Johnson, K.J.

    1995-12-31

    This paper will describe a new sand control method used in area of Ecuador, South America where workover rigs are not readily available. Sand production had been significantly affecting maintenance costs on surface and downhole production equipment and had impacted performance of the downhole jet pump, subsequently causing a decrease in well production. By installing a small-diameter, sintered metal gravel-pack screen across the perforation interval and placing the gravel-pack sand with coiled tubing, the sand production was successfully controlled. The procedure and equipment used to perform this technique as well as post job data that provide results obtained will also be presented. Noteworthy advantages, such as recompletion without removal of the existing production completion string and without use of a workover rig, will also be discussed.

  8. Use of the dual-screen thru-tubing sand control method

    SciTech Connect (OSTI)

    Freiman, O.H.; Johnson, K.J.

    1994-12-31

    This paper describes a new sand control method used in an area of Ecuador, South America where workover rigs are not readily available. Sand production had been significantly affecting maintenance costs on surface and downhole production equipment and had impacted performance of the downhole jet pump, subsequently causing a decrease in well production. By installing a small-diameter, sintered metal gravel-pack screen across the perforation interval and placing the gravel-pack sand with coiled tubing, the sand production was successfully controlled. The procedure and equipment used to perform this technique as well as post job data that provide results obtained is also presented. Noteworthy advantages, such as recompletion without removal of the existing production completion string and without use of a workover rig, is also discussed.

  9. Characterization Report on Sand, Slag, and Crucible Residues and on Fluoride Residues

    SciTech Connect (OSTI)

    Murray, A.M.

    1999-02-10

    This paper reports on the chemical characterization of the sand, slag, and crucible (SS and C) residues and the fluoride residues that may be shipped from the Rocky Flats Environmental Technology Site (RFETS) to Savannah River Site (SRS).

  10. Well-to-Wheels Greenhouse Gas Emissions of Canadian Oil Sands...

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

    This range can be compared to 4.4 g CO2eMJ for U.S. conventional crude oil recovery. Depending on the extraction technology and product type output of oil sands projects, the ...

  11. An Investigation for Disposal of Drill Cuttings into Unconsolidated Sandstones and Clayey Sands

    SciTech Connect (OSTI)

    Mese, Ali; Dvorkin, Jack; Shillinglaw, John

    2000-09-11

    This project include experimental data and a set of models for relating elastic moduli/porosity/texture and static-to-dynamic moduli to strength and failure relationships for unconsolidated sands and clayey sands. The results of the project should provide the industry with a basis for wider use of oil base drilling fluids in water sensitive formations by implementing drill cutting injection into existing wells at abandoned formations and controlling fracture geometry to prevent ground water contamination.

  12. Emissions from Heavy-Duty Diesel Engine with EGR using Oil Sands Derived

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

    Fuels | Department of Energy Heavy-Duty Diesel Engine with EGR using Oil Sands Derived Fuels Emissions from Heavy-Duty Diesel Engine with EGR using Oil Sands Derived Fuels 2003 DEER Conference Presentation: National Research Council Canada, Ottawa, Ontario, Canada 2003_deer_neill.pdf (860.57 KB) More Documents & Publications Development of Advanced Combustion Technologies for Increased Thermal Efficiency Biodiesel Research Update Effect of the Composition of Hydrocarbon Streams on HCCI

  13. Experience from topside and subsea use of the erosion based sand monitoring system

    SciTech Connect (OSTI)

    Braaten, N.A.; Blakset, T.J.; Morton, D.

    1995-12-31

    This paper describes the use of an erosion based on-line sand monitoring system, both for topside and subsea applications. It shows the practical use of the system, both from a safety point of view, with the probe giving early warning of sand production/erosion, in addition to being a tool for optimizing the production from the oil/gas wells. The probe works equally well in all flow regimes, single or multiphase flow.

  14. Paleontological overview of oil shale and tar sands areas in Colorado, Utah, and Wyoming.

    SciTech Connect (OSTI)

    Murphey, P. C.; Daitch, D.; Environmental Science Division

    2009-02-11

    In August 2005, the U.S. Congress enacted the Energy Policy Act of 2005, Public Law 109-58. In Section 369 of this Act, also known as the ''Oil Shale, Tar Sands, and Other Strategic Unconventional Fuels Act of 2005,'' Congress declared that oil shale and tar sands (and other unconventional fuels) are strategically important domestic energy resources that should be developed to reduce the nation's growing dependence on oil from politically and economically unstable foreign sources. In addition, Congress declared that both research- and commercial-scale development of oil shale and tar sands should (1) be conducted in an environmentally sound manner using management practices that will minimize potential impacts, (2) occur with an emphasis on sustainability, and (3) benefit the United States while taking into account concerns of the affected states and communities. To support this declaration of policy, Congress directed the Secretary of the Interior to undertake a series of steps, several of which are directly related to the development of a commercial leasing program for oil shale and tar sands. One of these steps was the completion of a programmatic environmental impact statement (PEIS) to analyze the impacts of a commercial leasing program for oil shale and tar sands resources on public lands, with an emphasis on the most geologically prospective lands in Colorado, Utah, and Wyoming. For oil shale, the scope of the PEIS analysis includes public lands within the Green River, Washakie, Uinta, and Piceance Creek Basins. For tar sands, the scope includes Special Tar Sand Areas (STSAs) located in Utah. This paleontological resources overview report was prepared in support of the Oil Shale and Tar Sands Resource Management Plan Amendments to Address Land Use Allocations in Colorado, Utah, and Wyoming and PEIS, and it is intended to be used by Bureau of Land Management (BLM) regional paleontologists and field office staff to support future projectspecific analyses

  15. Stability of nickel-coated sand as gravel-pack material for thermal wells

    SciTech Connect (OSTI)

    Sacuta, A.; Nguyen, D.M.; Kissel, G.A. )

    1988-11-01

    Laboratory flow tests have been carried out to study the stability of various nickel-coated sands under aqueous steam temperature and pH conditions that may exist in thermal recovery operations. Other gravel-pack materials tested include Ottawa sand, sintered bauxite, cement clinker, zirconium oxide, and nickel pellets. A comparison was made between the performances of these materials after exposure to identical thermal and hydrolytic conditions. Test results indicate that nickel-coated sands are highly resistant to dissolution at temperatures as high as 300/sup 0/C (570/sup 0/F) and to solution pH's from 4.75 to 11. Weight losses measured after a 72-hour period were less than 1%. In contrast, weight losses from sintered bauxite, zirconium oxide, and Ottawa sand dissolution tests were 30 to 70 times higher under the same conditions. Cement clinker losses were in the intermediate range under alkaline conditions. API standard crushing and acid-solubility tests for proppants also were performed on nickel-coated sands. These results were favorable in that they exceeded the recommended standards. This study of nickel-coated sand stability and mechanical strength has demonstrated its high potential for application as either a gravel-pack material or proppant in thermal recovery operations.

  16. FIELD TESTING & OPTIMIZATION OF CO2/SAND FRACTURING TECHNOLOGY

    SciTech Connect (OSTI)

    Raymond L. Mazza

    2004-11-30

    These contract efforts involved the demonstration of a unique liquid free stimulation technology which was, at the beginning of these efforts, in 1993 unavailable in the US. The process had been developed, and patented in Canada in 1981, and held promise for stimulating liquid sensitive reservoirs in the US. The technology differs from that conventionally used in that liquid carbon dioxide (CO{sub 2}), instead of water is the base fluid. The CO{sub 2} is pumped as a liquid and then vaporizes at reservoir conditions, and because no other liquids or chemicals are used, a liquid free fracture is created. The process requires a specialized closed system blender to mix the liquid CO{sub 2} with proppant under pressure. These efforts were funded to consist of up to 21 cost-shared stimulation events. Because of the vagaries of CO{sub 2} supplies, service company support and operator interest only 19 stimulation events were performed in Montana, New Mexico, and Texas. Final reports have been prepared for each of the four demonstration groups, and the specifics of those demonstrations are summarized. A summary of the demonstrations of a novel liquid-free stimulation process which was performed in four groups of ''Candidate Wells'' situated in Crockett Co., TX; San Juan Co., NM; Phillips Co., MT; and Blaine Co., MT. The stimulation process which employs CO{sub 2} as the working fluid and the production responses were compared with those from wells treated with conventional stimulation technologies, primarily N{sub 2} foam, excepting those in Blaine Co., MT where the reservoir pressure is too low to clean up spent stimulation liquids. A total of 19 liquid-free CO{sub 2}/sand stimulations were performed in 16 wells and the production improvements were generally uneconomic.

  17. Processing of transparent polycrystalline AlON:Ce3+ scintillators

    SciTech Connect (OSTI)

    Chen, Ching -Fong; Yang, Pin; King, Graham; Tegtmeier, Eric L.

    2015-10-23

    A new polycrystalline ceramic scintillator is reported for potential use in radiation detection and medical imaging applications. The goal was to develop cerium-activated aluminum oxynitride (AlON:Ce3+) ceramics, which can be produced using ceramic processes in comparison to the high-cost, low-yield single-crystal growth technique. A phase pure AlON:Ce3+ powder with cubic symmetry was successfully synthesized at high temperature under a reducing atmosphere to convert Ce4+ to Ce3+ in the solid solution. We explored two different activator concentrations (0.5 and 1.0 mol%). Fully dense and transparent AlON:Ce3+ ceramics were produced by a liquid-phase-assisted pressureless sintering. The crystal field splitting around the Ce3+ activator in the AlON was comparable to the splitting induced by Br₋ and the Cl₋ ligands, which produced an emission spectrum perfectly matching the maximum quantum efficiency range of the photomultiplier tube for radiation detection. Both optical excitation and radiation ionizations in AlON:Ce3+ were demonstrated. Lastly, challenges and mechanisms related to the radioluminescence efficiency are discussed.

  18. Studies on Ca2+-Doped CeBr3 Scintillating Materials

    SciTech Connect (OSTI)

    Guss, P. [NSTec; Foster, M. E. [SNL; Wong, B. M. [SNL; Doty, F. P. [SNL; Shah, K. [RMD; Squillante, M. [RMD; Glodo, J. [RMD; Yuan, D. [NSTec

    2013-07-03

    Despite the outstanding scintillation performance characteristics of cerium tribromide (CeBr3) and cerium-activated lanthanum tribromide (LaBr3:Ce), their commercial availability and application is limited due to the difficulties of growing large, crack-free single crystals from these fragile materials. The objective of this investigation was to employ aliovalent doping to increase crystal strength while maintaining the optical properties of the crystal. One divalent dopant (Ca2+) was investigated as a dopant to strengthen CeBr3 without negatively impacting scintillation performance. Ingots containing nominal concentrations of 1.9% of the Ca2+ dopant were grown. Preliminary scintillation measurements are presented for this aliovalently doped scintillator. Ca2+-doped CeBr3 exhibited little or no change in the peak fluorescence emission for 371 nm optical excitation for CeBr3. The structural, electronic, and optical properties of CeBr3 crystals were investigated using the density functional theory within generalized gradient approximation. The calculated lattice parameters are in good agreement with the experimental data. The energy band structures and density of states were obtained. The optical properties of CeBr3, including the dielectric function, were calculated.

  19. SEMI-ANNUAL REPORTS FOR CE FLNG, LLC (CAMBRIDGE) - DK. NO. 12-123-LNG -

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

    ORDER 3193 | Department of Energy CE FLNG, LLC (CAMBRIDGE) - DK. NO. 12-123-LNG - ORDER 3193 SEMI-ANNUAL REPORTS FOR CE FLNG, LLC (CAMBRIDGE) - DK. NO. 12-123-LNG - ORDER 3193 April 2013 (330.47 KB) October 2013 (475.93 KB) April 2014 (137.83 KB) October 2014 (455.98 KB) April 2015 (566.96 KB) October 2015 (125.7 KB) April 2016 (98.14 KB) More Documents & Publications CE FLNG, LLC - FE DKT. NO. 12-123-LNG - ORDER 3193 EIS-0497: Notice of Intent to Prepare an Environmental Impact

  20. Magnitude of the magnetic exchange interaction in the heavy-fermion antiferromagnet CeRhIn?

    SciTech Connect (OSTI)

    Das, Pinaki [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Lin, S. -Z. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Ghimire, N.? J. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Huang, K. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Univ. of California, San Diego, La Jolla, CA (United States); Ronning, F. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Bauer, E.? D. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Thompson, J.? D. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Batista, C.? D. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Ehlers, G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Janoschek, M. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

    2014-12-01

    We have used high-resolution neutron spectroscopy experiments to determine the complete spin wave spectrum of the heavy-fermion antiferromagnet CeRhIn?. The spin wave dispersion can be quantitatively reproduced with a simple frustrated J??J? model that also naturally explains the magnetic spin-spiral ground state of CeRhIn? and yields a dominant in-plane nearest-neighbor magnetic exchange constant J?=0.74(3)??meV. Our results pave the way to a quantitative understanding of the rich low-temperature phase diagram of the prominent CeTIn? (T = Co, Rh, Ir) class of heavy-fermion materials.

  1. Antiferromagnetic Kondo lattice in the layered compound CePd1-xBi₂ and

    Office of Scientific and Technical Information (OSTI)

    comparison to the superconductor LaPd1-xBi₂ (Journal Article) | SciTech Connect Antiferromagnetic Kondo lattice in the layered compound CePd1-xBi₂ and comparison to the superconductor LaPd1-xBi₂ Citation Details In-Document Search Title: Antiferromagnetic Kondo lattice in the layered compound CePd1-xBi₂ and comparison to the superconductor LaPd1-xBi₂ The layered compound CePd1-xBi₂ with the tetragonal ZrCuSi₂-type structure was obtained from excess Bi flux. Magnetic

  2. SOLVING THE SHUGART QUEEN SAND PENASCO UNIT DECLINING PRODUCTION PROBLEM

    SciTech Connect (OSTI)

    Lowell Deckert

    2000-08-25

    The Penasco Shugart Queen Sand Unit located in sections 8, 9, 16 & 17, T18S, 31E Eddy County New Mexico is operated by MNA Enterprises Ltd. Co. Hobbs, NM. The first well in the Unit was drilled in 1939 and since that time the Unit produced 535,000 bbl of oil on primary recovery and 375,000 bbl of oil during secondary recovery operations that commenced in 1973. The Unit secondary to primary ratio is 0.7, but other Queen waterfloods in the area had considerably larger S/P ratios. On June 25 1999 MNA was awarded a grant under the Department of Energy's ''Technology Development with Independents'' program. The grant was used to fund a reservoir study to determine if additional waterflood reserves could be developed. A total of 14 well bores that penetrate the Queen at 3150 ft are within the Unit boundaries. Eleven of these wells produced oil during the past 60 years. Production records were pieced together from various sources including the very early state production records. One very early well had a resistivity log, but nine of the wells had no logs, and four wells had gamma ray-neutron count-rate perforating logs. Fortunately, recent offset deep drilling in the area provided a source of modern logs through the Queen. The logs from these wells were used to analyze the four old gamma ray-neutron logs within the Unit. Additionally the offset well log database was sufficient to construct maps through the unit based on geostatistical interpolation methods. The maps were used to define the input parameters required to simulate the primary and secondary producing history. The history-matched simulator was then used to evaluate four production scenarios. The best scenario produces 51,000 bbl of additional oil over a 10-year period. If the injection rate is held to 300 BWPD the oil rate declines to a constant 15 BOPD after the first year. The projections are reasonable when viewed in the context of the historical performance ({approx}30 BOPD with a {approx}600 BWPD

  3. Dune-dammed lakes of the Nebraska Sand Hills: Geologic setting and paleoclimatic implications

    SciTech Connect (OSTI)

    Loope, D.B.; Swinehart, J.B. (Univ. of Nebraska, Lincoln, NE (United States))

    1992-01-01

    Within the western half of this grass-stabilized dunefield, about 1,000 interdune lakes are grouped into two clusters here named the Blue and Birdwood lake basins. In the lake basins, those parts of the valley not filled by dune sand are occupied by modern lakes and Holocene lake sediments. The Blue Creek dam is mounded transverse to flow; spill-over of the lake basin takes place over bedrock on the east side of the dam when lake level is 2 m higher than present. The permeability of dune sand prevents massive overflow, and thereby contributes to the integrity and longevity of the dam. Preserved lake sediments in the basin indicate that Blue Creek was obstructed prior to 13,000 yr BP, probably during glacial maximum (18,000 yr BP). Extensive peats dated at 1,500-1,000 yr BP lie directly on fluvial sand and gravel along the Calamus River, a stream that presently discharges a nearly constant 350 cfs. These sediments indicate blockage of streams also took place when linear dunes were active in the eastern Sand Hills in Late Holocene time. With the onset of an arid episode, dunes forming an interfluves curtail the severity of runoff events. As the regional water table drops, drainages go dry and dunes move uncontested into blocking positions. Although drainages of the eastern Sand Hills appear to have repeatedly broken through sand-blocked channels, the Blue and Birdwood lake basins are still blocked by Late Pleistocene dune dams. The repeated episodes of stream blockage and interbedded lake sediments and dune sands behind the extant dams record several strong fluctuations in Holocene climate. Recently proposed climatic models indicate that the northward flow of warm, moist air from the Gulf of Mexico is enhanced when the Gulf's surface temperature is low and the Bermuda high is intensified and in a western position. When the Bermuda high moves eastward, the core of the North American continent becomes desiccated.

  4. Lattice instabilities in heavy fermion superconductors. [CeCu/sub 2/Si/sub 2/; CeAl/sub 3/; CeCu/sub 6/; UBe/sub 13/; UPt/sub 3/

    SciTech Connect (OSTI)

    Wohlleben, D.

    1987-01-01

    This paper shows that while in nonsuperconducting HF systems such as CeCu/sub 6/, CeAl/sub 3/ and stoichiometric CeCu/sub 2/Si/sub 2/, the large electronic ..gamma.. is due to a very narrow f band, in the three HF superconductors UBe/sub 13/, UPt/sub 3/ and nonstochiometric CeCu/sub 2/Si/sub 2/, it is not. The f band of these systems, as measured by their response to magnetic fields in three different ways, is much wider than suggested by the large ..gamma... According to their actual f band width, the HF superconductors belong into the Bantam Fermion class. It is argued that most of the large ..gamma.. of the HF superconductors is not of electronic origin and that it is instead caused by the precursor of a martensitic phase transition of the lattice or by a crystallographic phase mixture, i.e., that it is due to the displacive degrees of freedom. This suggests that the superconductivity of all three HF superconductors is caused by some special, low energy phonons rather than by a narrow f band. 52 refs., 4 figs., 3 tabs.

  5. A comparison of the structure and localized magnetism in Ce{sub 2}PdGa{sub 12} with the heavy fermion CePdGa{sub 6}

    SciTech Connect (OSTI)

    Macaluso, Robin T. [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States); Millican, Jasmine N. [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States); Nakatsuji, Satoru [Department of Physics, Kyoto University, Kyoto, Japan 606-8502 (Japan); Lee, Han-Oh [Department of Physics, University of California, Davis, CA 95616 (United States); Carter, B. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Moreno, Nelson O. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Fisk, Zachary [Department of Physics, University of California, Davis, CA 95616 (United States); Chan, Julia Y. [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States)]. E-mail: jchan@lsu.edu

    2005-11-15

    Single crystals of Ce{sub 2}PdGa{sub 12} have been synthesized in Ga flux and characterized by X-ray diffraction. This compound crystallizes in the tetragonal P4/nbm space group, Z=2 with lattice parameters of a=6.1040(2)A and c=15.5490(6)A. It shows strongly anisotropic magnetism and orders antiferromagnetically at T{sub N}{approx}11K. A field-induced metamagnetic transition to the ferromagnetic state is observed below T{sub N}. Structure-property relationships with the related heavy-fermion antiferromagnet CePdGa{sub 6} are discussed.

  6. Switching of the Spin-Density-Wave in CeCoIn5 probed by Thermal...

    Office of Scientific and Technical Information (OSTI)

    Title: Switching of the Spin-Density-Wave in CeCoIn5 probed by Thermal Conductivity Authors: Kim, Duk Young 1 ; Lin, Shizeng 1 ; Weickert, Franziska 2 ; Bauer, Eric Dietzgen ...

  7. Pressure-Induced Structural Phase Transition in CeNi: X-ray and...

    Office of Scientific and Technical Information (OSTI)

    Pressure-Induced Structural Phase Transition in CeNi: X-ray and Neutron Scattering Studies and First-Principles Calculations Citation Details In-Document Search Title: ...

  8. Acetaldehyde Adsorption and Reaction onCeO2(100) Thin Films

    SciTech Connect (OSTI)

    Mullins, David R; Albrecht, Peter M

    2013-01-01

    This study reports and compares the adsorption and dissociation of acetaldehyde on oxidized and reduced CeOX(100) thin films. Acetaldehyde reacts and decomposes on fully oxidized CeO2(100) whereas it desorbs molecularly at low temperature on CeO2(111). The primary products are CO, CO2 and water along with trace amounts of crotonaldehyde and acetylene. The acetaldehyde adsorbs as the 2-acetaldehyde species, dioxyethylene. Decomposition proceeds by dehydrogenation through acetate and enolate intermediates. The reaction pathway is similar on the reduced CeO2-X(100) surface however the inability to react with surface O on the reduced surface results in H2 rather than H2O desorption and C is left on the surface rather than producing CO and CO2. C-O bond cleavage in the enolate intermediate followed by reaction with surface H results in ethylene desorption.

  9. Chemical stability and Ce doping of LiMgAlF6 neutron scintillator

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

    Du, M. H.

    2014-11-13

    We perform density functional calculations to investigate LiMgAlF6 as a potential neutron scintillator material. The calculations of enthalpy of formation and phase diagram show that single-phase LiMgAlF6 can be grown but it should be more difficult than growing LiCaAlF6 and LiSrAlF6. Moreover, the formation energy calculations for substitutional Ce show that the concentration of Ce on the Al site is negligible but a high concentration (>1 at.%) of Ce on the Mg site is attainable provided that the Fermi level is more than 5 eV lower than the conduction band minimum. Acceptor doping should promote Ce incorporation in LiMgAlF6.

  10. f-electron correlations in nonmagnetic Ce studied by means of...

    Office of Scientific and Technical Information (OSTI)

    f-electron correlations in nonmagnetic Ce studied by means of spin-resolved resonant photoemission Citation Details In-Document Search Title: f-electron correlations in nonmagnetic ...

  11. Hyperfine field and magnetic structure in the B phase of CeCoIn5...

    Office of Scientific and Technical Information (OSTI)

    We re-analyze Nuclear Magnetic Resonance (NMR) spectra observed at low temperatures and high magnetic fields in the field-induced B-phase of CeCoInsub 5. The NMR spectra are ...

  12. ASKO Appliances: Order (2012-CE-19/2004) | Department of Energy

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

    (2012-CE-192004) July 20, 2012 DOE ordered ASKO Appliances, Inc. to pay a 36,500 civil penalty after finding ASKO had failed to certify that certain models of residential...

  13. Determination of the Surface Structure of CeO2(111) by Low-Energy...

    Office of Scientific and Technical Information (OSTI)

    Title: Determination of the Surface Structure of CeO2(111) by Low-Energy Electron Diffraction. Abstract not provided. Authors: McCarty, Kevin F. ; Siegel, David A ; El Gabaly ...

  14. Switching of the Spin-Density-Wave in CeCoIn5 probed by Thermal...

    Office of Scientific and Technical Information (OSTI)

    Switching of the Spin-Density-Wave in CeCoIn5 probed by Thermal Conductivity Citation ... Visit OSTI to utilize additional information resources in energy science and technology. A ...

  15. Pressure tuning of competing magnetic interactions in intermetallic CeFe2

    SciTech Connect (OSTI)

    Wang, Jiyang; Feng, Yejun; Jaramillo, R.; van Wezel, Jasper; Canfield, Paul C.; Rosenbaum, T.F.

    2012-07-20

    We use high-pressure magnetic x-ray diffraction and numerical simulation to determine the low-temperature magnetic phase diagram of stoichiometric CeFe2. Near 1.5 GPa we find a transition from ferromagnetism to antiferromagnetism, accompanied by a rhombohedral distortion of the cubic Laves crystal lattice. By comparing pressure and chemical substitution we find that the phase transition is controlled by a shift of magnetic frustration from the Ce-Ce to the Fe-Fe sublattice. Notably the dominant Ce-Fe magnetic interaction, which sets the temperature scale for the onset of long-range order, remains satisfied throughout the phase diagram but does not determine the magnetic ground state. Our results illustrate the complexity of a system with multiple competing magnetic energy scales and lead to a general model for magnetism in cubic Laves phase intermetallic compounds.

  16. NMR studies of field induced magnetism in CeCoIn5 (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: NMR studies of field induced magnetism in CeCoIn5 Citation Details In-Document Search Title: ... Publication Date: 2009-01-01 OSTI Identifier: 972060 Report ...

  17. Magnetic Hardening of CeFe11Ti and the Effect of TiC Addition...

    Office of Scientific and Technical Information (OSTI)

    Magnetic Hardening of CeFe11Ti and the Effect of TiC Addition Citation ... Publication Date: 2015-04-01 OSTI Identifier: 1221660 Report Number(s): IS-J 8423 Journal ID: ISSN ...

  18. Reevaluation of Stevens sand potential - Maricopa depocenter, southern San Joaquin basin, California

    SciTech Connect (OSTI)

    Kolb, M.M.; Parks, S.L. )

    1991-02-01

    During the upper Miocene in the Southern San Joaquin basin surrounding highlands contributed coarse material to a deep marine basin dominated by fine grained silicious bioclastic deposition. these coarse deposits became reservoirs isolated within the silicious Antelope Shale Member of the Monterey Formation. In the southern Maricopa depocenter these Stevens sands are productive at Yowlumne, Landslide, Aqueduct, Rio Viejo, San Emidio Nose, Paloma, and Midway-Sunset fields, and are major exploration targets in surrounding areas. In the ARCO Fee lands area of the southern Maricopa depocenter, Stevens sands occur as rapidly thickening lens-shaped bodies that formed as channel, levee, and lobe deposits of deep-marine fan systems. These fans were fed from a southerly source, with apparent transport in a north-northwesterly direction. Sands deflect gently around present-day structural highs indicating that growth of structures influenced depositional patterns. Correlations reveal two major fan depositional intervals bounded by regional N, O, and P chert markers. Each interval contains numerous individual fan deposits, with many lobes and channels recognizable on three-dimensional seismic data. In addition to these basinal sand plays presently being evaluated, ARCO is pursuing a relatively new trend on Fee lands along the southern basin margin, where correlation to mountain data reveals Stevens sands trend into the steeply dipping beds of the mountain front. This area, the upturned Stevens,' has large reserve potential and producing analogies at Metson, Leutholtz, Los Lobos, and Pleito Ranch fields.

  19. The extraction of bitumen from western oil sands. Annual report, July 1991--July 1992

    SciTech Connect (OSTI)

    Oblad, A.G.; Bunger, J.W.; Dahlstrom, D.A.; Deo, M.D.; Hanson, F.V.; Miller, J.D.; Seader, J.D.

    1992-08-01

    The University of Utah tar sand research and development program is concerned with research and development on Utah is extensive oil sands deposits. The program has been intended to develop a scientific and technological base required for eventual commercial recovery of the heavy oils from oil sands and processing these oils to produce synthetic crude oil and other products such as asphalt. The overall program is based on mining the oil sand, processing the mined sand to recover the heavy oils and upgrading them to products. Multiple deposits are being investigated since it is believed that a large scale (approximately 20,000 bbl/day) plant would require the use of resources from more than one deposit. The tasks or projects in the program are organized according to the following classification: Recovery technologies which includes thermal recovery methods, water extraction methods, and solvent extraction methods; upgrading and processing technologies which covers hydrotreating, hydrocracking, and hydropyrolysis; solvent extraction; production of specialty products; and environmental aspects of the production and processing technologies. These tasks are covered in this report.

  20. Regional aeolian dynamics and sand mixing in the Gran Desierto: Evidence from Landsat thematic mapper images

    SciTech Connect (OSTI)

    Blount, G.; Greeley, R.; Christensen, P.R. (Arizona State Univ., Tempe (USA)); Smith, M.O.; Adams, J.B. (Univ. of Washington, Seattle (USA))

    1990-09-10

    Spatial variations in sand composition were mapped on a regional scale in a terrestrial sand sea, the Gran Desierto of Sonora, Mexico. Mesoscale mapping on a satellite image base allowed quantitative interpretation of the dynamic development of sand sheets and dunes. The results were used to interpret the Quaternary geologic history of the tectonically active region at the mouth of the Colorado River. Landsat thematic mapper multispectral images were used to predict the abundance of different mineralogies of sand grains in a mixed aeolian terrain. A spectral mixing model separated the effects of vegetation and topographically induced shading and shadow from the effects produced by different mineral and rock types. Compositions determined remotely agreed well with samples from selected areas within the spectral limitations of the thematic mapper. A simple discrimination capability for active versus inactive sand surfaces is demonstrated based upon differences in the percentage of low-albedo accessory grains occurring on dormant aeolian surfaces. A technique for discriminating between low-albedo materials and macroscopic shade is implemented by combing thermal images with the results of the spectral mixing model. The image analysis revealed important compositional variations over large areas that were not readily apparent in the field.

  1. Ex Parte Communications in Connection with Docket No EERE-2014-BT-CE-0019

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

    Energy Conservation Program: Certification, Compliance, Labeling, and Enforcement for Electric Motors and Small Electric Motors; Proposed Rule | Department of Energy No EERE-2014-BT-CE-0019 Energy Conservation Program: Certification, Compliance, Labeling, and Enforcement for Electric Motors and Small Electric Motors; Proposed Rule Ex Parte Communications in Connection with Docket No EERE-2014-BT-CE-0019 Energy Conservation Program: Certification, Compliance, Labeling, and Enforcement for

  2. Structure and magnetic properties of LnMnSbO ( Ln=La and Ce)

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

    Zhang, Qiang; Kumar, C. M. N.; Tian, Wei; Dennis, Kevin W.; Goldman, Alan I.; Vaknin, David

    2016-03-11

    Here, a neutron powder diffraction (NPD) study of LnMnSbO (Ln = La or Ce) reveals differences between the magnetic ground state of the two compounds due to the strong Ce-Mn coupling compared to La-Mn. The two compounds adopt the P4/nmm space group down to 2 K, and whereas magnetization measurements do not show obvious anomaly at high temperatures, NPD reveals a C-type antiferromagnetic (AFM) order below TN = 255K for LaMnSbO and 240 K for CeMnSbO. While the magnetic structure of LaMnSbO is preserved to base temperature, a sharp transition at TSR = 4.5K is observed in CeMnSbO due tomore » a spin-reorientation (SR) transition of the Mn2+ magnetic moments from pointing along the c axis to the ab plane. The SR transition in CeMnSbO is accompanied by a simultaneous long-range AFM ordering of the Ce moments, which indicates that the Mn SR transition is driven by the Ce-Mn coupling. The ordered moments are found to be somewhat smaller than those expected for Mn2+ (S = 5/2) in insulators, but large enough to suggest that these compounds belong to the class of local-moment antiferromagnets. The lower TN found in these two compounds compared to the As-based counterparts (TN = 317 for LaMnAsO, TN = 347K for CeMnAsO) indicates that the Mn-Pn (Pn=As or Sb) hybridization that mediates the superexchange Mn-Pn-Mn coupling is weaker for the Sb-based compounds.« less

  3. Results for aliovalent doping of CeBr{sub 3} with Ca{sup 2+}

    SciTech Connect (OSTI)

    Guss, Paul; Foster, Michael E.; Wong, Bryan M.; Patrick Doty, F.; Shah, Kanai; Squillante, Michael R.; Shirwadkar, Urmila; Hawrami, Rastgo; Tower, Joshua; Yuan, Ding

    2014-01-21

    Despite the outstanding scintillation performance characteristics of cerium tribromide (CeBr{sub 3}) and cerium-activated lanthanum tribromide, their commercial availability and application are limited due to the difficulties of growing large, crack-free single crystals from these fragile materials. This investigation employed aliovalent doping to increase crystal strength while maintaining the optical properties of the crystal. One divalent dopant (Ca{sup 2+}) was used as a dopant to strengthen CeBr{sub 3} without negatively impacting scintillation performance. Ingots containing nominal concentrations of 1.9% of the Ca{sup 2+} dopant were grown, i.e., 1.9% of the CeBr{sub 3} molecules were replaced by CaBr{sub 2} molecules, to match our target replacement of 1 out of 54 cerium atoms be replaced by a calcium atom. Precisely the mixture was composed of 2.26 g of CaBr{sub 2} added to 222.14 g of CeBr{sub 3}. Preliminary scintillation measurements are presented for this aliovalently doped scintillator. Ca{sup 2+}-doped CeBr{sub 3} exhibited little or no change in the peak fluorescence emission for 371?nm optical excitation for CeBr{sub 3}. The structural, electronic, and optical properties of CeBr{sub 3} crystals were studied using the density functional theory within the generalized gradient approximation. Calculated lattice parameters are in agreement with the experimental data. The energy band structures and density of states were obtained. The optical properties of CeBr{sub 3}, including the dielectric function, were calculated.

  4. Mitsubishi Electric: Consent Decree (2011-CE-01/0202) | Department of

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

    Energy Mitsubishi Electric: Consent Decree (2011-CE-01/0202) Mitsubishi Electric: Consent Decree (2011-CE-01/0202) May 7, 2010 In this consent degree, the Air-Conditioning, Heating and Refrigeration Institute (AHRI) agrees to pay $5,000 on behalf of Mitsubishi Electric & Electronics, USA, Inc. Mitsubishi Electric agreed that the required certification reports were not filed with DOE; however, Mitsubishi had an agreement with AHRI for AHRI to submit those reports on Mitsubishi's behalf.

  5. An Update on Improvements to NiCE Support for RELAP-7

    SciTech Connect (OSTI)

    McCaskey, Alex; Wojtowicz, Anna; Deyton, Jordan H.; Patterson, Taylor C.; Billings, Jay Jay

    2015-01-01

    The Multiphysics Object-Oriented Simulation Environment (MOOSE) is a framework that facilitates the development of applications that rely on finite-element analysis to solve a coupled, nonlinear system of partial differential equations. RELAP-7 represents an update to the venerable RELAP-5 simulator that is built upon this framework and attempts to model the balance-of-plant concerns in a full nuclear plant. This report details the continued support and integration of RELAP-7 and the NEAMS Integrated Computational Environment (NiCE). RELAP-7 is fully supported by the NiCE due to on-going work to tightly integrate NiCE with the MOOSE framework, and subsequently the applications built upon it. NiCE development throughout the first quarter of FY15 has focused on improvements, bug fixes, and feature additions to existing MOOSE-based application support. Specifically, this report will focus on improvements to the NiCE MOOSE Model Builder, the MOOSE application job launcher, and the 3D Nuclear Plant Viewer. This report also includes a comprehensive tutorial that guides RELAP-7 users through the basic NiCE workflow: from input generation and 3D Plant modeling, to massively parallel job launch and post-simulation data visualization.

  6. Antiferromagnetic ordering in the doped Kondo insulator CeRhSb

    SciTech Connect (OSTI)

    Menon, L.; Malik, S.K.

    1997-06-01

    CeRhSb, the so-called {open_quotes}Kondo insulator,{close_quotes} is a mixed-valent compound showing a gap formation in the electronic density of states. On the other hand, CePdSb is ferromagnetically ordered with a Curie temperature of {approximately}17 K. We have carried out magnetic susceptibility and electrical resistivity measurements on CeRh{sub 1{minus}x}Pd{sub x}Sb (0{le}x{le}1.0), to study the ground-state properties of this system. For small Pd doping in CeRhSb, up to 20{percent}, the gap continually diminishes and no magnetic ordering is observed down to 2 K. In the region 0.3{le}x{le}0.4, as soon as the gap is suppressed, an antiferromagnetic ground state is observed. In the region 0.5{le}x{lt}0.7, the compounds are not single phase. At the CePdSb end, in the region 0.7{le}x{le}1, the ground state is ferromagnetic. The observation of an antiferromagnetic phase in the phase diagram of CeRh{sub 1{minus}x}Pd{sub x}Sb, where neither end is antiferromagnetic, is interesting and is discussed in the light of some recent theoretical models. {copyright} {ital 1997} {ital The American Physical Society}

  7. Structure and scintillation yield of Ce-doped AlGa substituted yttrium garnet

    SciTech Connect (OSTI)

    Sidletskiy, Oleg; Kononets, Valerii; Lebbou, Kheirreddine; Neicheva, Svetlana; Voloshina, Olesya; Bondar, Valerii; Baumer, Vyacheslav; Belikov, Konstantin; Gektin, Alexander; Grinyov, Boris; Joubert, Marie-France

    2012-11-15

    Highlights: ? Range of Y{sub 3}(Al{sub 1?x}Ga{sub x}){sub 5}O{sub 12}:Ce solid solution crystals are grown from melt by the Czochralski method. ? Light yield of mixed crystals reaches 130% of the YAG:Ce value at x ? 0.4. ? ?1% of antisite defects is formed in YGG:Ce, but no evidence of this is obtained for the rest of crystals. -- Abstract: Structure and scintillation yield of Y{sub 3}(Al{sub 1?x}Ga{sub x}){sub 5}O{sub 12}:Ce solid solution crystals are studied. Crystals are grown from melt by the Czochralski method. Distribution of host cations in crystal lattice is determined. Quantity of antisite defects in crystals is evaluated using XRD and atomic emission spectroscopy data. Trend of light output at Al/Ga substitution in Y{sub 3}(Al{sub 1?x}Ga{sub x}){sub 5}O{sub 12}:Ce is determined for the first time. Light output in mixed crystals reaches 130% comparative to Ce-doped yttriumaluminum garnet. Luminescence properties at Al/Ga substitution are evaluated.

  8. Effects of placement method on geotechnical behavior of hydraulic fill sands

    SciTech Connect (OSTI)

    Lee, K.M.; Shen, C.K.; Leung, D.H.K.; Mitchell, J.K.

    1999-10-01

    Results of an investigation of the geotechnical behavior of a hydraulic sand placed at a land reclamation site in Hong Kong are presented and interpreted. The study was conducted to aid in developing guidelines for quality control of hydraulic landfill placement. The work described consisted of: (1) field investigations; (2) static and cyclic triaxial testing; and (3) calibration chamber tests to study the cone penetration test versus D, relationships for marine sands obtained from the reclamation sites. The results of this study clearly indicate that the placement technique is the single most important factor controlling the geotechnical behavior of a given type of sand when placed as a hydraulic fill. The weakest zone is generally located just beneath the water level where fill deposition is placed by pipeline discharge.

  9. Luminescence properties and electronic structure of Ce{sup 3+}-doped gadolinium aluminum garnet

    SciTech Connect (OSTI)

    Dotsenko, V.P.; Berezovskaya, I.V.; Voloshinovskii, A.S.; Zadneprovski, B.I.; Efryushina, N.P.

    2015-04-15

    Highlights: • The luminescence properties of Ce{sup 3+} ions in (Y, Gd){sub 3}Al{sub 5}O{sub 12} are analyzed. • The Gd{sup 3+} → Y{sup 3+} substitution leads to increasing of Ce{sup 3+} noncubic crystal field splitting parameter. • The excitation spectra for the Ce{sup 3+} emission in GdAG contain bands at 6.67, 7.75, and 9.76 eV. • These features are due to the Ce{sup 3+}-bound exciton formation and O 2p → Al 3s, 3p transitions. • Contributions from Al atoms to the conduction-band density of states are quite essential. - Abstract: Yttrium-gadolinium aluminum garnets (YGdAG) doped with Ce{sup 3+} ions have been prepared by co-precipitation method. The luminescent properties of Ce{sup 3+} ions in Gd{sub 3(1−x)}Ce{sub 3x}Al{sub 5}O{sub 12} (x = 0.01) have been studied upon excitation in the 2–20 eV region. The substitution of Gd{sup 3+} for Y{sup 3+} in the garnet structure results in broadening the emission band and shifting its maximum towards the longer wavelengths. It was found that in addition to the 4f → 5d excitation bands of Ce{sup 3+} ions, the excitation spectra for the Ce{sup 3+} emission contain bands at 6.67, 7.75, and 9.76 eV. These bands are attributed to the Ce{sup 3+}-bound exciton formation and O 2p → Al 3s, 3p transitions, respectively. Although gadolinium states dominate near the bottom of the conduction band of Gd{sub 3}Al{sub 5}O{sub 12}, contributions from Al{sub tetr} and Al{sub oct} atoms to the conduction-band density of states are evaluated as quite essential.

  10. Clean and Secure Energy from Domestic Oil Shale and Oil Sands Resources

    SciTech Connect (OSTI)

    Spinti, Jennifer; Birgenheier, Lauren; Deo, Milind; Facelli, Julio; Hradisky, Michal; Kelly, Kerry; Miller, Jan; McLennan, John; Ring, Terry; Ruple, John; Uchitel, Kirsten

    2015-09-30

    This report summarizes the significant findings from the Clean and Secure Energy from Domestic Oil Shale and Oil Sands Resources program sponsored by the Department of Energy through the National Energy Technology Laboratory. There were four principle areas of research; Environmental, legal, and policy issues related to development of oil shale and oil sands resources; Economic and environmental assessment of domestic unconventional fuels industry; Basin-scale assessment of conventional and unconventional fuel development impacts; and Liquid fuel production by in situ thermal processing of oil shale Multiple research projects were conducted in each area and the results have been communicated via sponsored conferences, conference presentations, invited talks, interviews with the media, numerous topical reports, journal publications, and a book that summarizes much of the oil shale research relating to Utah’s Uinta Basin. In addition, a repository of materials related to oil shale and oil sands has been created within the University of Utah’s Institutional Repository, including the materials generated during this research program. Below is a listing of all topical and progress reports generated by this project and submitted to the Office of Science and Technical Information (OSTI). A listing of all peer-reviewed publications generated as a result of this project is included at the end of this report; Geomechanical and Fluid Transport Properties 1 (December, 2015); Validation Results for Core-Scale Oil Shale Pyrolysis (February, 2015); and Rates and Mechanisms of Oil Shale Pyrolysis: A Chemical Structure Approach (November, 2014); Policy Issues Associated With Using Simulation to Assess Environmental Impacts (November, 2014); Policy Analysis of the Canadian Oil Sands Experience (September, 2013); V-UQ of Generation 1 Simulator with AMSO Experimental Data (August, 2013); Lands with Wilderness Characteristics, Resource Management Plan Constraints, and Land Exchanges

  11. Response of Oil Sands Derived Fuels in Diesel HCCI Operation | Department

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

    of Energy Response of Oil Sands Derived Fuels in Diesel HCCI Operation Response of Oil Sands Derived Fuels in Diesel HCCI Operation Presentation given at the 2007 Diesel Engine-Efficiency & Emissions Research Conference (DEER 2007). 13-16 August, 2007, Detroit, Michigan. Sponsored by the U.S. Department of Energy's (DOE) Office of FreedomCAR and Vehicle Technologies (OFCVT). deer07_bunting.pdf (3.17 MB) More Documents & Publications APBF Effects on Combustion Statistical Overview of

  12. In situ heat treatment of a tar sands formation after drive process treatment

    DOE Patents [OSTI]

    Vinegar, Harold J.; Stanecki, John

    2010-09-21

    A method for treating a tar sands formation includes providing a drive fluid to a hydrocarbon containing layer of the tar sands formation to mobilize at least some hydrocarbons in the layer. At least some first hydrocarbons from the layer are produced. Heat is provided to the layer from one or more heaters located in the formation. At least some second hydrocarbons are produced from the layer of the formation. The second hydrocarbons include at least some hydrocarbons that are upgraded compared to the first hydrocarbons produced by using the drive fluid.

  13. Western Gas Sands Project: production histories of the Piceance and Uinta basins of Colorado and Utah

    SciTech Connect (OSTI)

    Anderson, S.; Kohout, J.

    1980-11-20

    Current United States geological tight sand designations in the Piceance and Uinta Basins' Western Gas Sands Project include the Mesaverde Group, Fort Union and Wasatch Formations. Others, such as the Dakota, Cedar Mountain, Morrison and Mancos may eventually be included. Future production from these formations will probably be closely associated with existing trends. Cumulative gas production through December 1979, of the Mesaverde Group, Fort Union and Wasatch Formations in the Piceance and Uinta Basins is less than 275 billion cubic feet. This contrasts dramatically with potential gas in place estimates of 360 trillion cubic feet. If the geology can be fully understood and engineering problems surmounted, significant potential reserves can be exploited.

  14. High-pressure coiled-tubing technology solves resin-sand-control problems

    SciTech Connect (OSTI)

    1997-06-01

    Operators of high-pressure offshore gas wells (> 5,000 psi) have had few options for controlling sand production. Sand-control (SC) processes can be economically prohibitive when they involve extensive mobilization, demobilization, and rig-up cost of the conventional offshore rig or hydraulic workover unit. Bullheading SC chemicals from the surface can damage the formation and prohibit production. Coiled-tubing (CT) technology now allows an offshore operator to remove extensive cement residue effectively from the wellbore and place chemical SC treatments in a high-pressure-gas environment. An example from the Gulf of Mexico illustrates the technology.

  15. Mineral resources of the Buffalo Hump and Sand Dunes Addition Wilderness Study Areas, Sweetwater County, Wyoming

    SciTech Connect (OSTI)

    Gibbons, A.B.; Barbon, H.N.; Kulik, D.M. (Geological Survey, Reston, VA (USA)); McDonnell, J.R. Jr. (US Bureau of Mines (US))

    1990-01-01

    The authors present a study to assess the potential for undiscovered mineral resources and appraise the identified resources of the Buffalo Hump and Sand Dunes Addition Wilderness Study Areas, southwestern Wyoming, There are no mines, prospects, or mineralized areas nor any producing oil or gas wells; however, there are occurrences of coal, claystone and shale, and sand. There is a moderate resource potential for oil shale and natural gas and a low resource potential for oil, for metals, including uranium, and for geothermal sources.

  16. Structure and Reactivity of Alkyl Ethers Adsorbed on CeO2(111) Model Catalysts

    SciTech Connect (OSTI)

    F Calaza; T Chen; D Mullins; S Overbury

    2011-12-31

    The effect of surface hydroxyls on the adsorption of ether on ceria was explored. Adsorption of dimethyl ether (DME) and diethyl ether (DEE) on oxidized and reduced CeO{sub 2}(111) films was studied and compared with Ru(0001) using RAIRS and sXPS within a UHV environment. On Ru(0001) the ethers adsorb weakly with the molecular plane close to parallel to the surface plane. On the ceria films, the adsorption of the ethers was stronger than on the metal surface, presumably due to stronger interaction of the ether oxygen lone pair electrons with a cerium cation. This interaction causes the ethers to tilt away from the surface plane compared to the Ru(0001) surface. No pronounced differences were found between oxidized (CeO{sub 2}) and reduced (CeOx) films. The adsorption of the ethers was found to be perturbed by the presence of OH groups on hydroxylated CeOx. In the case of DEE, the geometry of adsorption resembles that found on Ru, and in the case of dimethyl ether DME is in between that one found on clean CeOx and the metal surface. Decomposition of the DEE was observed on the OH/CeOx surface following high DEE exposure at 300 K and higher temperatures. Ethoxides and acetates were identified as adsorbed species on the surface by means of RAIRS and ethoxides and formates by s-XPS. No decomposition of dimethyl ether was observed on the OH/CeOx at these higher temperatures, implying that the dissociation of the C-O bond from ethers requires the presence of {beta}-hydrogen.

  17. Structure and Reactivity of Alkyl Ethers Adsorbed on CeO(2)(111) Model Catalysts

    SciTech Connect (OSTI)

    Calaza, Florencia C; Chen, Tsung-Liang; Mullins, David R; Overbury, Steven {Steve} H

    2011-01-01

    The effect of surface hydroxyls on the adsorption of ether on ceria was explored. Adsorption of dimethyl ether (DME) and diethyl ether (DEE) on oxidized and reduced CeO{sub 2}(111) films was studied and compared with Ru(0001) using RAIRS and sXPS within a UHV environment. On Ru(0001) the ethers adsorb weakly with the molecular plane close to parallel to the surface plane. On the ceria films, the adsorption of the ethers was stronger than on the metal surface, presumably due to stronger interaction of the ether oxygen lone pair electrons with a cerium cation. This interaction causes the ethers to tilt away from the surface plane compared to the Ru(0001) surface. No pronounced differences were found between oxidized (CeO{sub 2}) and reduced (CeOx) films. The adsorption of the ethers was found to be perturbed by the presence of OH groups on hydroxylated CeOx. In the case of DEE, the geometry of adsorption resembles that found on Ru, and in the case of dimethyl ether DME is in between that one found on clean CeOx and the metal surface. Decomposition of the DEE was observed on the OH/CeOx surface following high DEE exposure at 300 K and higher temperatures. Ethoxides and acetates were identified as adsorbed species on the surface by means of RAIRS and ethoxides and formates by s-XPS. No decomposition of dimethyl ether was observed on the OH/CeOx at these higher temperatures, implying that the dissociation of the C-O bond from ethers requires the presence of {beta}-hydrogen.

  18. U. S. Department of Energy (DOE) research and development programs for heavy oil and tar sand recovery

    SciTech Connect (OSTI)

    Anderson, H.R.

    1981-01-01

    The main emphasis of the DOE tar sand program described is to develop in situ techniques capable of recovering bitumen from domestic tar sand deposits. This program primarily involves field experiments of in situ techniques (in situ combustion and steam drive). Supporting activities include resource assessment, upgrading and surface processing research, and environmental permitting and control. 5 refs.

  19. Reduced graphene oxide/CeO{sub 2} nanocomposite with enhanced photocatalytic performance

    SciTech Connect (OSTI)

    Kaur, Jasmeet Anand, Kanika; Singh, Gurpreet; Hastir, Anita; Virpal,; Singh, Ravi Chand; Anand, Kanica

    2015-05-15

    In this work, reduced graphene oxide /cerium oxide (RGO/CeO{sub 2}) nanocomposite was synthesized by in situ reduction of cerium nitrate Ce(NO{sub 3}){sub 3}6H{sub 2}O in the presence of graphene oxide by hydrazine hydrate (N{sub 2}H{sub 4}.H{sub 2}O). The intrinsic characteristics of as-prepared nanocomposite were studied using powder x-ray diffraction (XRD), Raman spectroscopy and field-emission scanning electron microscopy (FESEM). The photocatalytic degradation of methylene blue (MB) was employed as a model reaction to evaluate the photocatalytic activity of the RGO/CeO{sub 2} nanocomposite. The as-obtained RGO/CeO{sub 2} nanocomposite displays a significantly enhanced photocatalytic degradation of MB dye in comparison with bare CeO{sub 2} nanoparticles under sunlight irradiation, which can be attributed to the improved separation of electron-hole pairs and enhanced adsorption performance due to presence of RGO.

  20. Ionic liquid-assisted sonochemical preparation of CeO2 nanoparticles for CO oxidation

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

    Alammar, Tarek; Noei, Heshmat; Wang, Yuemin; Grünert, Wolfgang; Mudring, Anja -Verena

    2014-10-10

    CeO2 nanoparticles were synthesized via a one-step ultrasound synthesis in different kinds of ionic liquids based on bis(trifluoromethanesulfonylamide, [Tf2N]–, in combination with various cations including 1-butyl-3-methylimidazolium ([C4mim]+), 1-ethyl-2,3-dimethylimidazolium ([Edimim]+), butyl-pyridinium([Py4]+), 1-butyl-1-methyl-pyrrolidinium ([Pyrr14]+), and 2-hydroxyethyl-trimethylammonium ([N1112OH]+). Depending on synthetic parameters, such as ionic liquid, Ce(IV) precursor, heating method, and precipitator, formed ceria exhibits different morphologies, varying from nanospheres, nanorods, nanoribbons, and nanoflowers. The morphology, crystallinity, and chemical composition of the obtained materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), Raman spectroscopy, and N2 adsorption. The structural and electronic propertiesmore » of the as-prepared CeO2 samples were probed by CO adsorption using IR spectroscopy under ultrahigh vacuum conditions. The catalytic activities of CeO2 nanoparticles were investigated in the oxidation of CO. CeO2 nanospheres obtained sonochemically in [C4mim][Tf2N] exhibit the best performance for low-temperature CO oxidation. As a result, the superior catalytic performance of this material can be related to its mesoporous structure, small particle size, large surface area, and high number of surface oxygen vacancy sites.« less

  1. Use of Brazilian sugarcane bagasse ash in concrete as sand replacement

    SciTech Connect (OSTI)

    Sales, Almir; Lima, Sofia Araujo

    2010-06-15

    Sugarcane today plays a major role in the worldwide economy, and Brazil is the leading producer of sugar and alcohol, which are important international commodities. The production process generates bagasse as a waste, which is used as fuel to stoke boilers that produce steam for electricity cogeneration. The final product of this burning is residual sugarcane bagasse ash (SBA), which is normally used as fertilizer in sugarcane plantations. Ash stands out among agroindustrial wastes because it results from energy generating processes. Many types of ash do not have hydraulic or pozzolanic reactivity, but can be used in civil construction as inert materials. The present study used ash collected from four sugar mills in the region of Sao Carlos, SP, Brazil, which is one of the world's largest producers of sugarcane. The ash samples were subjected to chemical characterization, sieve analysis, determination of specific gravity, X-ray diffraction, scanning electron microscopy, and solubilization and leaching tests. Mortars and concretes with SBA as sand replacement were produced and tests were carried out: compressive strength, tensile strength and elastic modulus. The results indicated that the SBA samples presented physical properties similar to those of natural sand. Several heavy metals were found in the SBA samples, indicating the need to restrict its use as a fertilizer. The mortars produced with SBA in place of sand showed better mechanical results than the reference samples. SBA can be used as a partial substitute of sand in concretes made with cement slag-modified Portland cement.

  2. Production of Natural Gas and Fluid Flow in Tight Sand Reservoirs

    SciTech Connect (OSTI)

    Maria Cecilia Bravo

    2006-06-30

    This document reports progress of this research effort in identifying relationships and defining dependencies between macroscopic reservoir parameters strongly affected by microscopic flow dynamics and production well performance in tight gas sand reservoirs. These dependencies are investigated by identifying the main transport mechanisms at the pore scale that should affect fluids flow at the reservoir scale. A critical review of commercial reservoir simulators, used to predict tight sand gas reservoir, revealed that many are poor when used to model fluid flow through tight reservoirs. Conventional simulators ignore altogether or model incorrectly certain phenomena such as, Knudsen diffusion, electro-kinetic effects, ordinary diffusion mechanisms and water vaporization. We studied the effect of Knudsen's number in Klinkenberg's equation and evaluated the effect of different flow regimes on Klinkenberg's parameter b. We developed a model capable of explaining the pressure dependence of this parameter that has been experimentally observed, but not explained in the conventional formalisms. We demonstrated the relevance of this, so far ignored effect, in tight sands reservoir modeling. A 2-D numerical simulator based on equations that capture the above mentioned phenomena was developed. Dynamic implications of new equations are comprehensively discussed in our work and their relative contribution to the flow rate is evaluated. We performed several simulation sensitivity studies that evidenced that, in general terms, our formalism should be implemented in order to get more reliable tight sands gas reservoirs' predictions.

  3. BIOTIGER, A NATURAL MICROBIAL PRODUCT FOR ENHANCED HYDROCARBON RECOVERY FROM OIL SANDS.

    SciTech Connect (OSTI)

    Brigmon, R; Topher Berry, T; Whitney Jones, W; Charles Milliken, C

    2008-05-27

    BioTiger{trademark} is a unique microbial consortia that resulted from over 8 years of extensive microbiology screening and characterization of samples collected from a century-old Polish waste lagoon. BioTiger{trademark} shows rapid and complete degradation of aliphatic and aromatic hydrocarbons, produces novel surfactants, is tolerant of both chemical and metal toxicity and shows good activity at temperature and pH extremes. Although originally developed and used by the U.S. Department of Energy for bioremediation of oil-contaminated soils, recent efforts have proven that BioTiger{trademark} can also be used to increase hydrocarbon recovery from oil sands. This enhanced ex situ oil recovery process utilizes BioTiger{trademark} to optimize bitumen separation. A floatation test protocol with oil sands from Ft. McMurray, Canada was used for the BioTiger{trademark} evaluation. A comparison of hot water extraction/floatation test of the oil sands performed with BioTiger{trademark} demonstrated a 50% improvement in separation as measured by gravimetric analysis in 4 h and a five-fold increase at 25 hr. Since BioTiger{trademark} performs well at high temperatures and process engineering can enhance and sustain metabolic activity, it can be applied to enhance recovery of hydrocarbons from oil sands or other complex recalcitrant matrices.

  4. Rock matrix and fracture analysis of flow in western tight gas sands: Annual report, Phase 3

    SciTech Connect (OSTI)

    Dandge, V.; Graham, M.; Gonzales, B.; Coker, D.

    1987-12-01

    Tight gas sands are a vast future source of natural gas. These sands are characterized as having very low porosity and permeability. The main resource development problem is efficiently extracting the gas from the reservoir. Future production depends on a combination of gas price and technological advances. Gas production can be enhanced by fracturing. Studies have shown that many aspects of fracture design and gas production are influenced by properties of the rock matrix. Computer models for stimulation procedures require accurate knowledge of flow properties of both the rock matrix and the fractured regions. In the proposed work, these properties will be measured along with advanced core analysis procedure aimed at understanding the relationship between pore structure and properties. The objective of this project is to develop reliable core analysis techniques for measuring the petrophysical properties of tight gas sands. Recent research has indicated that the flow conditions in the reservoir can be greatly enhanced by the presence of natural fractures, which serve as a transport path for gas from the less permeable matrix. The study is mainly concerned with the dependence of flow in tight gas matrix and healed tectonic fractures on water saturation and confining pressure. This dependency is to be related to the detailed pore structure of tight sands as typified by cores recovered in the Multi-Well experiment. 22 refs., 34 figs., 9 tabs.

  5. Increasing reserves through improved evaluation of low contrast pay sands: Lower Lagunillas, Bloque IV, Lake Maracaibo

    SciTech Connect (OSTI)

    Bryant, I.D.; Herron, M.; Matteson, A.; Ramamoorthy, R.

    1996-08-01

    Pay sands have traditionally been defined in the Lower Lagunillas reservoir by applying porosity and saturation cutoffs following a Waxman-Smits evaluation. This strategy has proven useful to identify sands which historically provided prolific production when completed over multiple zones in vertical wells. However, zones that were not attractive completion targets in vertical wells have been shown to be attractive targets for dedicated horizontal infill wells. The mineralogy of samples from old cores has been determined by Fourier Transform infrared spectroscopy. This mineralogical model has been implemented to provide improved evaluations of the shaly sands. This evaluation suggests that in-place oil volumes may be up to 23% higher. In new infill wells, FMI logs indicate that non-traditional pay zones comprise thinly laminated sands and shales. Incorporation of the these high resolution logs into high resolution petrophysical evaluations yields further increases in evaluated oil volumes of 44% in these zones. A recently drilled infill well has established that these zones can produce oil at economic rates in a horizontal drainhole.

  6. Deposition of carbonate mud beds within high-energy subtidal sand Dunes, Bahamas

    SciTech Connect (OSTI)

    Dill, R.F.; Steinen, R.P.

    1988-01-01

    Laminated, carbonate mud beds are being deposited in the interisland channels of the Exuma Cays in the Bahamas. They are associated with stromatolites and interbedded with ooid sands that form large migrating subtidal dunes on flood tidal deltas and bars. Currents up to 3 knots sweep in and out of the 4-8 m deep channels 3 hours out of every 6 hours, creating a high-energy bank margin environment not usually considered to be the site of mud-sized particle deposition. Mud deposits reach thicknesses of 1 m and have individual beds 2-5 cm thick. When exposed to flowing seawater, bed surfaces become encrusted with carbonate cement and algal mats. The white interior of mud beds between the crusts appears homogeneous, is soft, and has the consistency of ''tooth paste.'' Loose uncemented ooid sand is found above and below the mud beds, showing that both are occupying the same depositional environment. Rip-up clasts of the crusted mud beds, formed by scour of underlying sands, are carried throughout the channels and accumulate as a lag deposit within the troughs of migrating dunes. Some clasts are colonized by algal mats that trap ooid and skeletal sands forming stromatolite structures that can grow up to 2 m high.

  7. Structural and magnetic phase transitions in CeCu6-xTx (T = Ag,Pd)

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

    Poudel, Lekhanath N.; De la cruz, Clarina; Payzant, E. Andrew; Koehler, Michael R.; May, Andrew F.; Garlea, Vasile O.; Taylor, Alice E.; Parker, David S.; Cao, Huibo B.; McGuire, Michael A.; et al

    2015-12-15

    The structural and the magnetic properties of CeCu6-xAgx (0 ≤ x ≤ 0.85) and CeCu6-xPdx (0 ≤ x ≤ 0.4) have been studied using neutron diffraction, resonant ultrasound spectroscopy (RUS), x-ray diffraction measurements, and first principles calculations. The structural and magnetic phase diagrams of CeCu6-xAgx and CeCu6-xPdx as a function of Ag/Pd composition are reported. The end member, CeCu6, undergoes a structural phase transition from an orthorhombic (Pnma) to a monoclinic (P21/c) phase at 240 K. In CeCu6-xAgx, the structural phase transition temperature (Ts) decreases linearly with Ag concentration and extrapolates to zero at xS ≈ 0.1. The structural transitionmore » in CeCu6-xPdx remains unperturbed with Pd substitution within the range of our study. The lattice constant b slightly decreases with Ag/Pd doping, whereas a and c increase with an overall increase in the unit cell volume. Both systems, CeCu6-xAgx and CeCu6-xPdx, exhibit a magnetic quantum critical point (QCP), at x ≈ 0.2 and x ≈ 0.05, respectively. Near the QCP, long range antiferromagnetic ordering takes place at an incommensurate wave vector (δ1 0 δ2), where δ1 ~ 0.62, δ2 ~ 0.25, x = 0.125 for CeCu6-xPdx and δ1 ~ 0.64, δ2 ~ 0.3, x = 0.3 for CeCu6-xAgx. As a result, the magnetic structure consists of an amplitude modulation of the Ce moments which are aligned along the c axis of the orthorhombic unit cell.« less

  8. Proactive Design of n-Type (In, Ce) Filled Skutterudites Enabling High-Temperature Waste Heat Recovery

    Broader source: Energy.gov [DOE]

    Thermoelectric and structural properties of n-type (In, Ce) filled skutterudites including power factors and ZT as a function of temperature are presented

  9. La-Ce and Sm-Nd systematics of siliceous sedimentary rocks: A clue to marine environment in their deposition

    SciTech Connect (OSTI)

    Hiroshi Shimizu; Masayo Amano; Akimasa Masuda )

    1991-04-01

    La-Ce isotopic data, together with Sm-Nd isotopic data, were determined on siliceous sedimentary rocks (cherts) in order to elucidate the rare earth element (REE) character of their sources and the nature of their depositional environments. The cherts studied are a late Archean chert from the Gorge Creek Group in the Pilbara block of Western Australia, Triassic cherts from central Japan, and Cretaceous and Paleogene deep-sea cherts from the central Pacific and the Caribbean Sea. The Archean chert from the Gorge Creek Group shows chondritic Ce and Nd isotope ratios at its sedimentation age which indicate that its sources had a time-integrated chondritic REE pattern. Triassic cherts from Japan have initial Ce and Nd isotope ratios that show a direct derivation from their continental source. On the other hand, for Cretaceous and Paleogene deep-sea cherts having negative Ce anomalies in their REE patterns, two different sources for Ce and Nd are revealed from their initial Ce and Nd isotope data: Ce from long-term light-REE-depleted oceanic volcanic rocks and Nd from light-REE-enriched continental rocks. The reverse nature observed for deep-sea cherts is considered to be a reflection of their depositional environment far from a continent. These results confirm that the La-Ce isotope system is highly useful in determining the nature and cause of Ce anomalies observed in marine sedimentary rocks such as chert.

  10. Occurrence of gas hydrate in Oligocene Frio sand: Alaminos Canyon Block 818: Northern Gulf of Mexico

    SciTech Connect (OSTI)

    Boswell, R.D.; Shelander, D.; Lee, M.; Latham, T.; Collett, T.; Guerin, G.; Moridis, G.; Reagan, M.; Goldberg, D.

    2009-07-15

    A unique set of high-quality downhole shallow subsurface well log data combined with industry standard 3D seismic data from the Alaminos Canyon area has enabled the first detailed description of a concentrated gas hydrate accumulation within sand in the Gulf of Mexico. The gas hydrate occurs within very fine grained, immature volcaniclastic sands of the Oligocene Frio sand. Analysis of well data acquired from the Alaminos Canyon Block 818 No.1 ('Tigershark') well shows a total gas hydrate occurrence 13 m thick, with inferred gas hydrate saturation as high as 80% of sediment pore space. Average porosity in the reservoir is estimated from log data at approximately 42%. Permeability in the absence of gas hydrates, as revealed from the analysis of core samples retrieved from the well, ranges from 600 to 1500 millidarcies. The 3-D seismic data reveals a strong reflector consistent with significant increase in acoustic velocities that correlates with the top of the gas-hydrate-bearing sand. This reflector extends across an area of approximately 0.8 km{sup 2} and delineates the minimal probable extent of the gas hydrate accumulation. The base of the inferred gas-hydrate zone also correlates well with a very strong seismic reflector that indicates transition into units of significantly reduced acoustic velocity. Seismic inversion analyses indicate uniformly high gas-hydrate saturations throughout the region where the Frio sand exists within the gas hydrate stability zone. Numerical modeling of the potential production of natural gas from the interpreted accumulation indicates serious challenges for depressurization-based production in settings with strong potential pressure support from extensive underlying aquifers.

  11. A comparison of general circulation model predictions to sand drift and dune orientations

    SciTech Connect (OSTI)

    Blumberg, D.G.; Greeley, R.

    1996-12-01

    The growing concern over climate change and decertification stresses the importance of aeolian process prediction. In this paper the use of a general circulation model to predict current aeolian features is examined. A GCM developed at NASA/Goddard Space Flight Center was used in conjunction with White`s aeolian sand flux model to produce a global potential aeolian transport map. Surface wind shear stress predictions were used from the output of a GCM simulation that was performed as part of the Atmospheric Model Intercomparison Project on 1979 climate conditions. The spatial resolution of this study (as driven by the GCM) is 4{degrees} X 5{degrees}; instantaneous 6-hourly wind stress data were saved by the GCM and used in this report. A global map showing potential sand transport was compared to drift potential directions as inferred from Landsat images from the 1980s for several sand seas and a coastal dune field. Generally, results show a good correlation between the simulated sand drift direction and the drift direction inferred for dune forms. Discrepancies between the drift potential and the drift inferred from images were found in the North American deserts and the Arabian peninsula. An attempt to predict the type of dune that would be formed in specific regions was not successful. The model could probably be further improved by incorporating soil moisture, surface roughness, and vegetation information for a better assessment of sand threshold conditions. The correlation may permit use of a GCM to analyze {open_quotes}fossil{close_quotes} dunes or to forecast aeolian processes. 48 refs., 8 figs.

  12. Vortexlike excitations in the heavy-fermion superconductor CeIrIn5

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

    Luo, Yongkang; Rosa, P. F. S.; Bauer, E. D.; Thompson, J. D.

    2016-05-05

    Here, we report a systematic study of temperature- and field-dependent charge (ρ) and entropy (S) transport in the heavy-fermion superconductor CeIrIn5. Its large positive thermopower Sxx is typical of Ce-based Kondo lattice systems, and strong electronic correlations play an important role in enhancing the Nernst signal Sxy. By separating the off-diagonal Peltier coefficient αxy from Sxy, we find that αxy becomes positive and greatly enhanced at temperatures well above the bulk Tc. Compared with the nonmagnetic analog LaIrIn5, these results suggest vortexlike excitations in a precursor state to unconventional superconductivity in CeIrIn5. This study sheds light on the similarity ofmore » heavy-fermion and cuprate superconductors and on the possibility of states not characterized by the amplitude of an order parameter.« less

  13. Structural and photoluminescence properties of Ce, Dy, Er-doped ZnO nanoparticles

    SciTech Connect (OSTI)

    Jayachandraiah, C.; Kumar, K. Siva; Krishnaiah, G.

    2015-06-24

    Undoped ZnO and rare earth elements (Ce, Dy and Er with 2 at. %) doped nanoparticles were synthesized by wet chemical co-precipitation method at 90°C with Polyvinylpyrrolidone (PVP) as capping agent. The structural, morphological, compositional and photoluminescence studies were performed with X-ray diffraction (XRD), Transmission electron microscopy (TEM), Energy dispersive spectroscopy (EDS), FTIR spectroscopy and Photoluminescence (PL) respectively. XRD results revealed hexagonal wurtzite structure with average particle size around 18 nm - 14 nm and are compatible with TEM results. EDS confirm the incorporation of Ce, Dy and Er elements into the host ZnO matrix and is validated by FTIR analysis. PL studies showed a broad intensive emission peak at 558 nm in all the samples. The intensity for Er- doped ZnO found maximum with additional Er shoulder peaks at 516nm and 538 nm. No Ce, Dy emission centers were found in spectra.

  14. A Comparative Study of the Water Gas Shift Reaction Over Platinum Catalysts Supported on CeO2, TiO2 and Ce-Modified TiO2

    SciTech Connect (OSTI)

    Gonzalez, I.; Navarro, R; Wen, W; Marinkovic, N; Rodriguez, J; Rosa, F; Fierro, J

    2010-01-01

    WGS reaction has been investigated on catalysts based on platinum supported over CeO{sub 2}, TiO{sub 2} and Ce-modified TiO{sub 2}. XPS and XANES analyses performed on calcined catalysts revealed a close contact between Pt precursors and cerium species on CeO{sub 2} and Ce-modified TiO{sub 2} supports. TPR results corroborate the intimate contact between Pt and cerium entities in the Pt/Ce-TiO{sub 2} catalyst that facilitates the reducibility of the support at low temperatures while the Ce-O-Ti surface interactions established in the Ce-modified TiO{sub 2} support decreases the reduction of TiO{sub 2} at high temperature. The changes in the support reducibility leads to significant differences in the WGS activity of the studied catalysts. Pt supported on Ce-modified TiO{sub 2} support exhibits better activity than those corresponding to individual CeO{sub 2} and TiO{sub 2}-supported catalysts. Additionally, the Ce-TiO{sub 2}-supported catalyst displays better stability at reaction temperatures higher than 573 K that observed on pure TiO{sub 2}-supported counterpart. Activity measurements, when coupled with the physicochemical characterization of catalysts suggest that the modifications in the surface reducibility of the support play an essential role in the enhancement of activity and stability observed when Pt is supported on the Ce-modified TiO{sub 2} substrate.

  15. Structural and spectroscopic properties of pure and doped LiCe(PO{sub 3}){sub 4}

    SciTech Connect (OSTI)

    Abdelhedi, M.; Horchani-Naifer, K.; Dammak, M.; Ferid, M.

    2015-10-15

    Graphical abstract: Emission and excitation and spectra of Eu{sup 3+} doped LiCe(PO{sub 3}){sub 4} host lattice with 1, 2, 3 and 4 mol%. - Highlights: • Europium–doped LiCe(PO{sub 3}){sub 4} were prepared by flux method. • It was analyzed by infrared and Raman spectroscopy, and luminescence spectroscopy. • LiCe(PO{sub 3}){sub 4} doped with Eu{sup 3+} ions as luminophore host materials to produce an intense red. - Abstract: Single crystals of LiCe(PO{sub 3}){sub 4} polyphosphate have been synthesized by the flux method and its structural and luminescence properties have been investigated. This compound crystallizes in the space group C2/c with unit cell dimensions a = 16.52(7) Å, b = 7.09(4) Å, c = 9.83 (4)Å, β = 126.29(4)°, Z = 8 and V = 927.84(3) Å{sup 3}. The obtained polytetraphosphate exhibits very small crystals and the dopant Eu{sup 3+} ions were successfully incorporated into the sites of Ce{sup 3+} ions of the host lattice. The spectroscopy properties confirm the potentiality of present LiCe(PO{sub 3}){sub 4} doped with Eu{sup 3+} ions as luminophore host materials to produce an intense red luminescence at 628 nm corresponding to {sup 5}D{sub 0} → {sup 7}F{sub 2} emission level and have significant importance in the development of emission optical systems.

  16. Magnetic properties of Ce{sup 3+} in Pb{sub 1{minus}x}Ce{sub x}Se: Kondo and crystal-field effect

    SciTech Connect (OSTI)

    Gratens, X.; Charar, S.; Averous, M.; Isber, S.; Deportes, J.; Golacki, Z.

    1997-10-01

    Electron paramagnetic resonance (EPR) experiments were performed on a Pb{sub 1{minus}x}Ce{sub x}Se crystal at liquid-helium temperatures and show very clearly that the doublet {Gamma}{sub 7} is the ground state for cerium ions. The cubic symmetry is shown and the effective Land{acute e} factor for the Ce{sup 3+} is determined to be 1.354{plus_minus}0.003. An orbital reduction factor is introduced to explain the g experimental value. High-field magnetization results are in good agreement with the EPR results. The nominal Ce composition in PbSe deduced from saturation of the magnetization, x=0.0405{plus_minus}0.0003, is very closed to the value determined by microprobe analysis (x=0.04). At 1.5 K, an antiferromagnetic interaction between the nearest-neighbor cerium atoms is found, J{sub ex}/k{sub B}={minus}0.715thinspK. The low-field magnetic-susceptibility results show that the magnetic moment of cerium impurities is strongly temperature dependent, explained by the presence of the crystal-field effect and the Kondo effect. {copyright} {ital 1997} {ital The American Physical Society}

  17. Comparative Study on Redox Properties of Nanosized CeO2 and CuO/Ce2 Under CO/O2

    SciTech Connect (OSTI)

    Martinez-Arias,A.; Gamarra, D.; Fernandez-Garcia, M.; Wang, X.; Hanson, J.; Rodriguez, J.

    2006-01-01

    Nanosized CeO{sub 2} and CuO/CeO{sub 2} samples, active for CO-PROX or related processes were comparatively examined by O{sub 2} probe electron paramagnetic resonance and in situ Raman and X-ray diffraction techniques. Their behavior toward CO reduction, as well as the oxygen-handling properties of the CO-reduced samples, was explored. An appreciable reduction of the ceria bulk was detected on treatment under CO at 473 K. On the basis of the analysis of the evolution of different oxygen-derived species (superoxide, peroxide, O-) on low-temperature (77-300 K) oxygen chemisorption on the CO-reduced samples, a general picture of the redox properties of the samples is presented. Results demonstrate that the presence of copper promotes completion of the redox cycle under CO/O{sub 2} by favoring both ceria reduction and oxidation. This can be relevant to explaining the remarkable oxidation activity and synergetic effects observed for catalysts combining CuO and CeO{sub 2}.

  18. Interplay of structural, optical and magnetic properties in Gd doped CeO{sub 2}

    SciTech Connect (OSTI)

    Soni, S.; Dalela, S.; Kumar, Sudish; Meena, R. S.; Vats, V. S.

    2015-06-24

    In this research wok systematic investigation on the synthesis, characterization, optical and magnetic properties of Ce{sub 1-x}Gd{sub x}O{sub 2} (where x=0.02, 0.04, 0.06, and 0.10) synthesized using the Solid-state method. Structural, Optical and Magnetic properties of the samples were investigated by X-ray diffraction (XRD), UV-VIS-NIR spectroscopy and VSM. Fluorite structure is confirmed from the XRD measurement on Gd doped CeO{sub 2} samples. Magnetic studies showed that the Gd doped polycrystalline samples display room temperature ferromagnetism and the ferromagnetic ordering strengthens with the Gd concentration.

  19. Mechanism of Methane Chemical Looping Combustion with Hematite Promoted with CeO2

    SciTech Connect (OSTI)

    Miller, Duane D.; Siriwardane, Ranjani

    2013-08-01

    Chemical looping combustion (CLC) is a promising technology for fossil fuel combustion that produces sequestration-ready CO{sub 2} stream, reducing the energy penalty of CO{sub 2} separation from flue gases. An effective oxygen carrier for CLC will readily react with the fuel gas and will be reoxidized upon contact with oxygen. This study investigated the development of a CeO{sub 2}-promoted Fe{sub 2}O{sub 3}?hematite oxygen carrier suitable for the methane CLC process. Composition of CeO{sub 2} is between 5 and 25 wt % and is lower than what is generally used for supports in Fe{sub 2}O{sub 3} carrier preparations. The incorporation of CeO{sub 2} to the natural ore hematite strongly modifies the reduction behavior in comparison to that of CeO{sub 2} and hematite alone. Temperature-programmed reaction studies revealed that the addition of even 5 wt % CeO{sub 2} enhances the reaction capacity of the Fe{sub 2}O{sub 3} oxygen carrier by promoting the decomposition and partial oxidation of methane. Fixed-bed reactor data showed that the 5 wt % cerium oxides with 95 wt % iron oxide produce 2 times as much carbon dioxide in comparison to the sum of carbon dioxide produced when the oxides were tested separately. This effect is likely due to the reaction of CeO{sub 2} with methane forming intermediates, which are reactive for extracting oxygen from Fe{sub 2}O{sub 3} at a considerably faster rate than the rate of the direct reaction of Fe{sub 2}O{sub 3} with methane. These studies reveal that 5 wt % CeO{sub 2}/Fe{sub 2}O{sub 3} gives stable conversions over 15 reduction/oxidation cycles. Lab-scale reactor studies (pulsed mode) suggest the methane reacts initially with CeO{sub 2} lattice oxygen to form partial oxidation products (CO + H{sub 2}), which continue to react with oxygen from neighboring Fe{sub 2}O{sub 3}, leading to its complete oxidation to form CO{sub 2}. The reduced cerium oxide promotes the methane decomposition reaction to form C + H{sub 2}, which continue to

  20. Ferromagnetic Kondo lattice CeRuSi{sub 2} with non-Fermi-liquid behavior

    SciTech Connect (OSTI)

    Nikiforov, V. N.; Baran, M.; Irkhin, V. Yu.

    2013-05-15

    The structure, electronic, thermodynamic, and magnetic properties of the CeRuSi{sub 2} Kondo lattice with ferromagnetic ordering characterized by a small moment of the ground state are investigated. Anomalies in the temperature dependences of heat capacity and resistivity (unusual power or logarithmic behavior) observed in the low-temperature range indicate a non-Fermi-liquid behavior. The results are compared with those for other Ce{sub l}Ru{sub n}X{sub m} compounds and anomalous systems based on rare-earth elements and actinides that had been studied earlier.

  1. {ital Ab Initio} Calculation of Crystalline Electric Fields and Kondo Temperatures in Ce Compounds

    SciTech Connect (OSTI)

    Han, J.; Alouani, M.; Cox, D.; Han, J.; Cox, D.; Alouani, M.

    1997-02-01

    We have calculated the band-f hybridizations for Ce{sub x}La{sub 1-x}M{sub 3} compounds (x=1 and x{r_arrow}0; M=Pb,In,Sn,Pd) within the local density approximation and fed this into a noncrossing approximation for the Anderson impurity model applied to both dilute and concentrated limits. Our calculations produce crystalline electric field splittings and Kondo temperatures with trends in good agreement with experiment and demonstrate the need for detailed electronic structure information on hybridization to describe the diverse behaviors of these Ce compounds. {copyright} {ital 1997} {ital The American Physical Society}

  2. (U) Analysis of shock-initiated PBX-9501 through porous CeO2

    SciTech Connect (OSTI)

    Fredenburg, David A.; Dattelbaum, Dana Mcgraw; Dennis-Koller, Darcie

    2015-07-24

    The attenuation properties of an impact initiated PBX-9501 explosive through several thicknesses of CeO2 powder is investigated. The CeO2 is at an initial porous density of 4.0 g/cm3 , roughly 55 % of theoretical maximum density. Measurements of the input (into the powder) and propagated (through the powder) wave profiles are measured using optical velocimetry. Results show a reduction of the average wave speed, CX, and peak steady-state material velocity, uP , with increasing powder thickness from 1.5 - 5.0 mm.

  3. Thermodynamic and Transport Properties of YTe3, LaTe3 and CeTe3

    SciTech Connect (OSTI)

    Ru, N.

    2011-08-19

    Measurements of heat capacity, susceptibility, and electrical resistivity are presented for single crystals of the charge density wave compounds YTe{sub 3}, LaTe{sub 3}, and CeTe{sub 3}. The materials are metallic to low temperatures, but have a small density of states due to the charge density wave gapping large portions of the Fermi surface. CeTe{sub 3} is found to be a weak Kondo lattice, with an antiferromagnetic ground state and T{sub N} = 2.8 K. The electrical resistivity of all three compounds is highly anisotropic, confirming the weak dispersion perpendicular to Te planes predicted by band structure calculations.

  4. Optical properties of the Ce and La ditelluride charge density wave compounds

    SciTech Connect (OSTI)

    Lavagnini, M.; Sacchetti, A.; Degiorgi, L.; Shin, K.Y.; Fisher, I.R.; /Stanford U., Geballe Lab. /Stanford U., Appl. Phys. Dept.

    2010-02-15

    The La and Ce di-tellurides LaTe{sub 2} and CeTe{sub 2} are deep in the charge-density-wave (CDW) ground state even at 300 K. We have collected their electrodynamic response over a broad spectral range from the far infrared up to the ultraviolet. We establish the energy scale of the single particle excitation across the CDW gap. Moreover, we find that the CDW collective state gaps a very large portion of the Fermi surface. Similarly to the related rare earth tri-tellurides, we envisage that interactions and Umklapp processes play a role in the onset of the CDW broken symmetry ground state.

  5. Meso-scale cooling effects of high albedo surfaces: Analysis of meteorological data from White Sands National Monument and White Sands Missile Range

    SciTech Connect (OSTI)

    Fishman, B.; Taha, H.; Akbari, H.

    1994-05-20

    Urban summer daytime temperatures often exceed those of the surrounding rural areas. Summer ``urban heat islands`` are caused by dark roofs and paved surfaces as well as the lack of vegetation. Researchers at Lawrence Berkeley Laboratory are interested in studying the effects of increasing the albedo of roof tops and paved surfaces in order to reduce the impacts of summer urban heat islands. Increasing the albedo of urban surfaces may reduce this heat island effect in two ways, directly and indirectly. The direct effect involves reducing surface temperature and, therefore, heat conduction through the building envelope. This effect of surface albedo on surface temperatures is better understood and has been quantified in several studies. The indirect effect is the impact of high albedo surfaces on the near surface air temperatures. Although the indirect effect has been modeled for the Los Angeles basin by Sailor, direct field observations are required. The objective of this report is to investigate the meso-scale climate of a large high albedo area and identify the effects of albedo on the near surface air temperature. To accomplish this task, data from several surface weather stations at White Sands, New Mexico were analyzed. This report is organized into six sections in addition to this introduction. The first gives the general geological, topographic, and meteorological background of White Sands. The second is a discussion of the basic surface meteorology of the White Sands region. This section is followed by a general discussion of the instrumentation and available data. The fourth section is a description of the method used for data analyis. The fifth section which presents the results of this analysis. Finally, the last section is the summary and conclusion, where a discussion of the results is presented.

  6. X-ray computed-tomography observations of water flow through anisotropic methane hydrate-bearing sand

    SciTech Connect (OSTI)

    Seol, Yongkoo; Kneafsey, Timothy J.

    2009-06-01

    We used X-ray computed tomography (CT) to image and quantify the effect of a heterogeneous sand grain-size distribution on the formation and dissociation of methane hydrate, as well as the effect on water flow through the heterogeneous hydrate-bearing sand. A 28 cm long sand column was packed with several segments having vertical and horizontal layers with sands of different grain-size distributions. During the hydrate formation, water redistribution occurred. Observations of water flow through the hydrate-bearing sands showed that water was imbibed more readily into the fine sand, and that higher hydrate saturation increased water imbibition in the coarse sand due to increased capillary strength. Hydrate dissociation induced by depressurization resulted in different flow patterns with the different grain sizes and hydrate saturations, but the relationships between dissociation rates and the grain sizes could not be identified using the CT images. The formation, presence, and dissociation of hydrate in the pore space dramatically impact water saturation and flow in the system.

  7. The synthesis and optical property of solid-state-prepared YAG:Ce phosphor by a spray-drying method

    SciTech Connect (OSTI)

    Lee, H.-M.; Cheng, C.-C.; Huang, C.-Y.

    2009-05-06

    Ce{sup 3+}-activated yttrium aluminum garnet (Y{sub 3}Al{sub 5}O{sub 12}:Ce, YAG:Ce) powder as luminescent phosphor was synthesized by the solid-state reaction method. The phase identification, microstructure and photoluminescent properties of the products were investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), absorption spectrum and photoluminescence (PL) analysis. Spherical phosphor particle is considered better than irregular-shaped particle to improve PL property and application, so this phosphor was granulated into a sphere-like shape by a spray-drying device. After calcinating at 1500 deg. C for 0, 4, and 8 h, the product was identified as YAG and CeO{sub 2} phases. The CeO{sub 2} phase content is decreased by increasing the calcination time or decreasing the Ce{sup 3+} doping content. The product showed higher emission intensity resulted from more Ce{sup 3+} content and larger grain size. The product with CeO{sub 2} was found to have lower emission intensity. This paper presents the crystal structures of Rietveld refinement results of powder XRD data.

  8. Influence of Electron Doping on Magnetic Order in CeRu2Al10

    SciTech Connect (OSTI)

    Kobayashi, Riki; Kaneko, Koji; Saito, Kotaro; Mignot, Jean-Michel; Andre, Gilles; Robert, Julien; Wakimoto, Shuichi; Matsuda, Masaaki; Chi, Songxue; Haga, Yoshinori; Matsuda, Tatsuma; Yamamoto, Etsuji; Nishioka, Takashi; Tanida, Hiroshi; Sera, Masafumi

    2014-01-01

    The effect of electron doping by the substitution of Rh for Ru on unconventional magnetic order in CeRu2Al10 was investigated via neutron powder diffraction. In Ce(Ru1 xRhx)2Al10 with x = 0.05, 0.12, and 0.2, reorientation of the ordered moment from the c-axis as in pure CeRu2Al10 to the a-axis takes place in all samples, while the ordering vector q 0; 1; 0 remains unchanged within this concentration range. The moment reorientation is accompanied by an increase in its size by a factor of 2.4, from = 0.43 B at x = 0 to = 1.06, 1.04, and 1.02 B for x = 0.05, 0.12, and 0.2, respectively. The continuous decrease in the N el temperature T0(TN), despite an abrupt increase in , underlines the strong anisotropy in the exchange interaction in CeRu2Al10 and the fact that this anisotropy is easily suppressed by electron doping. 1.

  9. CE IGCC Repowering plant sulfuric acid plant. Topical report, June 1993

    SciTech Connect (OSTI)

    Chester, A.M.

    1993-12-01

    A goal of the CE IGCC Repowering project is to demonstrate a hot gas clean-up system (HGCU), for the removal of sulfur from the product gas stream exiting the gasifier island. Combustion Engineering, Inc. (ABB CE) intends to use a HGCU developed by General Electric Environmental Services (GEESI). The original design of this system called for the installation of the HGCU, with a conventional cold gas clean-up system included as a full-load operational back-up. Each of these systems removes sulfur compounds and converts them into an acid off-gas. This report deals with the investigation of equipment to treat this off-gas, recovering these sulfur compounds as elemental sulfur, sulfuric acid or some other form. ABB CE contracted ABB Lummus Crest Inc. (ABB LCI) to perform an engineering evaluation to compare several such process options. This study concluded that the installation of a sulfuric acid plant represented the best option from both a technical and economic point of view. Based on this evaluation, ABB CE specified that a sulfuric acid plant be installed to remove sulfur from off-gas exiling the gas clean-up system. ABB LCI prepared a request for quotation (RFQ) for the construction of a sulfuric acid production plant. Monsanto Enviro-Chem Inc. presented the only proposal, and was eventually selected as the EPC contractor for this system.

  10. Charge dynamics of Ce-based compounds: Connection between the mixed valent and Kondo-insulator states

    SciTech Connect (OSTI)

    Bucher, B. [Laboratorium fuer Festkoerperphysik, Eidgenoessische Technische Hochschule Zuerich, 8093 Zuerich (Switzerland)] [Laboratorium fuer Festkoerperphysik, Eidgenoessische Technische Hochschule Zuerich, 8093 Zuerich (Switzerland); Schlesinger, Z. [IBM, Thomas J. Watson Research Center, Yorktown Heights, New York 10958 (United States)] [IBM, Thomas J. Watson Research Center, Yorktown Heights, New York 10958 (United States); Mandrus, D.; Fisk, Z.; Sarrao, J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); DiTusa, J.F.; Oglesby, C.; Aeppli, G.; Bucher, E. [AT& T Bell Laboratories, Murray Hill, New Jersey 07974 (United States)] [AT& T Bell Laboratories, Murray Hill, New Jersey 07974 (United States)

    1996-02-01

    The reflectivities of the mixed-valent compounds CeSn{sub 3} and CePd{sub 3} have been measured to obtain the optical conductivity as a function of temperature. Both compounds show a renormalization of the low-energy Drude conductivity at low temperatures. In addition, for the low-carrier-density compound CePd{sub 3}, but not for high-carrier-density CeSn{sub 3}, substantial spectral weight lost from the conductivity below 1000 cm{sup {minus}1} reappears in the frequency range 2000{endash}10000 cm{sup {minus}1}, indicating that CePd{sub 3} can be considered a lightly doped Kondo insulator. {copyright} {ital 1996 The American Physical Society.}

  11. Photocatalytic degradation mechanisms of self-assembled rose-flower-like CeO{sub 2} hierarchical nanostructures

    SciTech Connect (OSTI)

    Sabari Arul, N.; Department of Nanoscience and Technology, Bharathiar University, Coimbatore-641 046 ; Mangalaraj, D.; Whan Kim, Tae

    2013-06-03

    Hierarchical rose-flower-like CeO{sub 2} nanostructures were formed by using solvothermal and thermal annealing processes. The CeCO{sub 3}OH thin film was transformed into CeO{sub 2} roses due to thermal annealing. CeO{sub 2} nanostructured roses exhibited excellent photocatalytic activity with a degradation rate of 65% for the azo dye acid orange 7 (AO7) under ultraviolet illumination. The fitting of the absorbance maximum versus time showed that the degradation of AO7 obeyed pseudo-first-order reaction kinetics. The enhancement of the photocatalytic activity for the CeO{sub 2} roses was attributed to the high adsorptivity resulting from the surface active sites and special 4f electron configuration.

  12. Method of producing drive fluid in situ in tar sands formations

    DOE Patents [OSTI]

    Mudunuri, Ramesh Raju (Houston, TX); Jaiswal, Namit (Houston, TX); Vinegar, Harold J. (Bellaire, TX); Karanikas, John Michael (Houston, TX)

    2010-03-23

    Methods of treating a tar sands formation are described herein. Methods for treating a tar sands may include providing heat to at least part of a hydrocarbon layer in the formation from one or more heaters located in the formation. The heat may be allowed to transfer from the heaters to at least a portion of the formation such that a drive fluid is produced in situ in the formation. The drive fluid may move at least some mobilized, visbroken, and/or pyrolyzed hydrocarbons from a first portion of the formation to a second portion of the formation. At least some of the mobilized, visbroken, and/or pyrolyzed hydrocarbons may be produced from the formation.

  13. Controlling and assessing pressure conditions during treatment of tar sands formations

    SciTech Connect (OSTI)

    Zhang, Etuan; Beer, Gary Lee

    2015-11-10

    A method for treating a tar sands formation includes providing heat to at least part of a hydrocarbon layer in the tar sands formation from a plurality of heaters located in the formation. Heat is allowed to transfer from the heaters to at least a portion of the formation. A pressure in the portion of the formation is controlled such that the pressure remains below a fracture pressure of the formation overburden while allowing the portion of the formation to heat to a selected average temperature of at least about 280.degree. C. and at most about 300.degree. C. The pressure in the portion of the formation is reduced to a selected pressure after the portion of the formation reaches the selected average temperature.

  14. Advanced secondary recovery project for the Sooner D Sand Unit, Weld County, Colorado: Final report

    SciTech Connect (OSTI)

    Sippel, M.A.; Cammon, T.J.

    1986-06-01

    The objective of this project was to increase production at the Sooner D Sand Unit through geologically targeted infill drilling and improved reservoir management of waterflood operations. The Sooner D Sand Unit demonstration project should be an example for other operators to follow for reservoir characterization and exploitation methodologies to increase production by waterflood from the Cretaceous D Sandstone in the Denver-Julesburg (D-J) Basin. This project involved multi-disciplinary reservoir characterization using high-density 3D seismic, detailed stratigraphy and reservoir simulation studies. Infill drilling, water-injection conversion and re-completing some wells to add short-radius laterals were based on the results of the reservoir characterization studies. Production response were evaluated using reservoir simulation and production tests. Technology transfer utilized workshops, presentations and technical papers which emphasized the economic advantages of implementing the demonstrated technologies.

  15. Postmortem analysis of sand grain crushing from pile interface using X-ray tomography

    SciTech Connect (OSTI)

    Silva, I. Matias; Combe, Gaeel; Foray, Pierre; Flin, Frederic; Lesaffre, Bernard [Universite de Grenoble, 3SR Lab, UMR 5521 Grenoble-INP, UJF-Grenoble 1, CNRS, Grenoble, France CEN, CNRM-GAME UMR 3589, Meteo France - CNRS, Grenoble (France)

    2013-06-18

    Pile foundations of offshore platforms, wind and water turbines are typically subjected to a variety of cyclic loading paths due to their complex environment. While many studies focus on global pile behaviour, the soil-pile interface is explored here by a micromechanical study of the soil layer in contact with the pile surface. This work is devoted to the analysis of frozen post-mortem silica sand samples recovered at the pile interface following installation and cyclic loading tests in a calibration chamber using x-ray tomography. An experimental procedure developed for three dimensional (3D) snow imaging was adapted for the recovery of the in-situ sand samples to preserve their structure during tomography scans. 3D images at a pixel size of 7 {mu}m were then obtained using a cryogenic cell. Results confirm the presence of a shear band at the pile surface as well as void ratios changes in the direction of the pile's radius.

  16. Nondestructive Evaluation and Monitoring Projects NASA White Sands Test Facility (WSTF)

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

    Workshop Sandia National Laboratories Livermore, CA Nondestructive Evaluation and Monitoring Projects NASA White Sands Test Facility (WSTF) POCs: NASA WSTF: Regor Saulsberry (575) 524-5518 Overview * Background and Projects Overview * Survey of Test Projects of Interest * NASA Nondestructive Evaluation (NDE) Working Group (NNWG) Testing * Orbiter Testing - NNWG Piggyback Efforts 2 Background and Issues * Safe applications of Composite Pressure Vessels (CPVs) is major concern - The NASA

  17. Annual Groundwater Monitoring Report SANDIA REPORT SAND2008-0972P

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

    Groundwater Monitoring Report SANDIA REPORT SAND2008-0972P Unlimited Release Printed March 2008 Fiscal Year 2007 Prepared by Sandia National Laboratories, Albuquerque, New Mexico Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94A185000 Approved for public release; further dissemination unlimited Editor/Document Production: Rebecca Sanchez

  18. Experimental study of effective stress response of sand under water wave loading

    SciTech Connect (OSTI)

    Clukey, E.C.; Kulhawy, F.H.; Liu, P.L.F.; Turcotte, B.R.

    1984-05-01

    This paper presents experimental wave-sediment interaction data obtained in a 17.1 m long wave tank facility. Pore water pressures as well as total stresses were measured to determine the effective stress response of a medium grained sand subjected to wave heights up to 0.28 m. The results were compared with the theory presented by Yamamoto at the 1978 OTC.

  19. II international conference on heavy crude and tar sands. Summary report

    SciTech Connect (OSTI)

    Not Available

    1982-01-01

    The Second International Conference on Heavy Crude and Tar Sands clearly demonstrated that the world has abundant heavy and extra heavy crudes that will sustain the petroleum age for decades. Perhaps even more important for many developed and developing countries is that these resources are widely distributed throughout the world, for deposits are known to exist in at least forty-nine countries. Moreover, the rapid expansion over the last two and a half years of knowledge of the magnitude of these resources suggests there is much more to be added to the world's list of useful energy assets. The current ample supply of crude oil does not appear to have lessened the resolve to develop heavy crude and tar sands. Major industrial countries are eager to develop their heavy oil resources to free themselves from dependence on OPEC and the developing nations hope to reduce their cash outflows for imported oil which they can ill afford. Venezuela and Canada, which both have massive heavy crude reserves, are intent on developing their resources to supplement declining supplies of light oil. Despite the weakening international price of oil, the economics for many heavy crude ventures seem favorable. Statistics quoted at the conference suggest considerable heavy crude production can be brought on stream at costs approaching the finding costs of light conventional crude. At the same time, it has to be acknowledged that those large tar sands projects, like Alberta's multi-billion dollar ventures, are sufficiently marginal that they may be held back by current soft oil demand. This summary report covers the following areas: resources; international cooperation; production; environment; technological developments; upgrading and refining; marketing; and future of heavy crude oil and tar sands.

  20. Kauai Test Facility, Hawaii Sandia Report SAND2014-16456R Unlimited Release

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

    annual site environmental report for sandia national laboratories, Tonopah Test range, Nevada & Kauai Test Facility, Hawaii Sandia Report SAND2014-16456R Unlimited Release Printed September 2014 Prepared by Sandia National Laboratories Albuquerque, New Mexico 87185 Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security

  1. Western Gas Sands Project status report, 1 February-29 February 1980

    SciTech Connect (OSTI)

    Not Available

    1980-01-01

    This edition of the WGSP Status Report summarizes the progress during February 1980, of the government-sponsored projects directed toward increasing gas production from low-permeability gas sands of the western United States. The National Laboratories and Energy Technology Centers continued research and experiments toward enhanced gas recovery. The field test and demonstration program continued with various projects, including test data collection by the DOE Well Test Facility at CIG's Miller No. 1 site.

  2. for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. SAND No. SAND2016-4688 M

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

    SAND No. SAND2016-4688 M SOLAR GLARE HAZARD ANALYSIS TOOL (SGHAT) v. 3.0 Sandia Copyright #1567.2 Technology Readiness Level:8 Actual technology is completed and qualified through test and demonstration TECHNOLOGY DESCRIPTION With growing numbers of solar energy systems being proposed and installed throughout the United States, the potential impact of glint and glare from photovoltaic modules, concentrating solar collectors, receivers, and other components is receiving increased attention as a

  3. Fundamental Understanding of the Interaction of Acid Gases with CeO2 : From Surface Science to Practical Catalysis

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

    Tumuluri, Uma; Rother, Gernot; Wu, Zili

    2016-03-21

    Acid gases including CO2, SO2, and NOx are ubiquitous in large-scale energy applications including heterogeneous catalysis. The adverse environmental and health effects of these acid gases have resulted in high interest in the research and development of technologies to remove or convert these acid gases. The main challenge for the development of these technologies is to develop catalysts that are highly efficient, stable, and cost-effective, and many catalysts have been reported in this regard. CeO2 and CeO2-based catalysts have gained prominence in the removal and conversion of CO2, SO2, and NOx because of their structural robustness and redox and acid–basemore » properties. In this article, we provide a brief overview of the application of CeO2 and CeO2-based catalysts for the removal of CO2, SO2, and NOx gases with an emphasis on the fundamental understanding of the interactions of these acid gases with CeO2. The studies summarized in this review range from surface science using single crystals and thin films with precise crystallographic planes to practical catalysis applications of nanocrystalline and polycrystalline CeO2 materials with defects and dopants. After an introduction to the properties of CeO2 surfaces, their catalytic properties for conversions of different acid gases are reviewed and discussed. Lastly, we find that the surface atomic structure, oxygen vacancies, and surface acid–base properties of CeO2 play vital roles in the surface chemistry and structure evolution during the interactions of acid gases with CeO2 and CeO2-based catalysts.« less

  4. (U) Equation of State and Compaction Modeling for CeO2

    SciTech Connect (OSTI)

    Fredenburg, David A.; Chisolm, Eric D.

    2014-10-20

    Recent efforts have focused on developing a solid-liquid and three-phase equation of state (EOS) for CeO2, while parallel experimental efforts have focused on obtaining high-fidelity Hugoniot measurements on CeO2 in the porous state. The current work examines the robustness of two CeO2 SESAME equations of state, a solid-liquid EOS, 96170, and a three-phase EOS, 96171, by validating the EOS against a suite of high-pressure shock compression experiments on initially porous CeO2. At lower pressures compaction is considered by incorporating a two-term exponential form of the P-compaction model, using three separate definitions for ?(P). Simulations are executed spanning the partially compacted and fully compacted EOS regimes over the pressure range 0.5 - 109 GPa. Comparison of calculated Hugoniot results with those obtained experimentally indicate good agreement for all definitions of ?(P) with both the solid-liquid and three-phase EOS in the low-pressure compaction regime. At higher pressures the three-phase EOS does a better job at predicting the measured Hugoniot response, though at the highest pressures EOS 96171 predicts a less compliant response than is observed experimentally. Measured material velocity profiles of the shock-wave after it has transmitted through the powder are also compared with those simulated using with solid-liquid and three-phase EOS. Profiles lend insight into limits of the current experimental design, as well as the threshold conditions for the shock-induced phase transition in CeO2.

  5. Oil shale, tar sand, coal research advanced exploratory process technology, jointly sponsored research

    SciTech Connect (OSTI)

    Speight, J.G.

    1992-01-01

    Accomplishments for the past quarter are presented for the following five tasks: oil shale; tar sand; coal; advanced exploratory process technology; and jointly sponsored research. Oil shale research covers oil shale process studies. Tar sand research is on process development of Recycle Oil Pyrolysis and Extraction (ROPE) Process. Coal research covers: coal combustion; integrated coal processing concepts; and solid waste management. Advanced exploratory process technology includes: advanced process concepts;advanced mitigation concepts; and oil and gas technology. Jointly sponsored research includes: organic and inorganic hazardous waste stabilization; CROW field demonstration with Bell Lumber and Pole; development and validation of a standard test method for sequential batch extraction fluid; PGI demonstration project; operation and evaluation of the CO[sub 2] HUFF-N-PUFF Process; fly ash binder for unsurfaced road aggregates; solid state NMR analysis of Mesaverde Group, Greater Green River Basin, tight gas sands; flow-loop testing of double-wall pipe for thermal applications; characterization of petroleum residue; shallow oil production using horizontal wells with enhanced oil recovery techniques; surface process study for oil recovery using a thermal extraction process; NMR analysis of samples from the ocean drilling program; in situ treatment of manufactured gas plant contaminated soils demonstration program; and solid state NMR analysis of naturally and artificially matured kerogens.

  6. New opportunities in Lower B sands VLC-100/949 reservoirs, Block III, Lake Maracaibo

    SciTech Connect (OSTI)

    Gonzalez, G.; Coll, C.; Mora, J.L. )

    1996-01-01

    The Lower B Misoa Formation of Middle Eocene age is characterized by massive sand bodies. These sands were successfully tested in the northern part of Block III in Lake Maracaibo in 1956. Subsequent drilling during the next 27 years has failed to locate any productive pay zones. Only during the past 8 years, new seismic and well data have delineated a number of minor oil reservoirs resulting in extensive production from Misoa Lower B sands. The oil production came primarily from small structural traps located on the hanging walls of normal listric faults. Fault diagnosis and locations were more accurately mapped with the availability of 3-D seismic data. Consequently, VLC-100 and VLC-949 reservoirs are now considered to be part of the same trap instead of being separated. A careful review of the fluid distribution and material balance calculations has confirmed that the wells from these reservoirs have, in fact, been producing from the same accumulation thereby validating the new geological model. The new model has defined new opportunities of oil exploitation. Firstly, it has led to the drilling of 4 new wells and increased production by 4,500 STB/D. Secondly, it has indicated additional recovery opportunities in the form of drilling horizontal wells in the updip area. Finally, the new model indicates the existence of an aquifer of much lower strength than was previously thought. This has caused a revision in our reservoir management strategy and we now recommend water injection to supplement the aquifer support and enhance oil recovery.

  7. Reservoir characterization of the Lower B sands VLC 100/949 Reservoirs, Block III, Lake Maracaibo

    SciTech Connect (OSTI)

    Gonzalez, G.; Coll, C.; Mora, J.L.; Meza, E.

    1996-08-01

    The Lower B Misoa Formation of Middle Eocene age is characterized by massive sand bodies. These sands were successfully tested in the northern part of Block III in Lake Maracaibo in 1956. Subsequent drilling during the next 27 years has failed to locate any productive pay zones. Only during the past 8 years, new seismic and well data have delineated a number of minor oil reservoirs resulting in extensive production from Misoa Lower B sands. The oil production came primarily from small structural traps located on the hanging walls of normal listric faults. Fault diagnosis and locations were more accurately mapped with the availability of 3-D seismic data. Consequently VLC-100 and VLC-949 reservoirs are now considered to be part of the same trap instead of being separated. A careful review of the fluid distribution and material balance calculations has confirmed that the wells from these reservoirs have, in fact, been producing from the same accumulation thereby validating the new geological model. The new model has defined new opportunities of oil exploitation. Firstly, it has led to the drilling of 4 new wells and increased production by 4500 STB/D. Secondly, it has indicated additional recovery opportunities in the form of drilling horizontal wells in the updip area. Finally, the new model indicates the existence of an aquifer of much lower strength than was previously thought. This has caused a revision in our reservoir management strategy, and we now recommend water injection to supplement the aquifer support and enhance oil recovery.

  8. New opportunities in Lower B sands VLC-100/949 reservoirs, Block III, Lake Maracaibo

    SciTech Connect (OSTI)

    Gonzalez, G.; Coll, C.; Mora, J.L.

    1996-12-31

    The Lower B Misoa Formation of Middle Eocene age is characterized by massive sand bodies. These sands were successfully tested in the northern part of Block III in Lake Maracaibo in 1956. Subsequent drilling during the next 27 years has failed to locate any productive pay zones. Only during the past 8 years, new seismic and well data have delineated a number of minor oil reservoirs resulting in extensive production from Misoa Lower B sands. The oil production came primarily from small structural traps located on the hanging walls of normal listric faults. Fault diagnosis and locations were more accurately mapped with the availability of 3-D seismic data. Consequently, VLC-100 and VLC-949 reservoirs are now considered to be part of the same trap instead of being separated. A careful review of the fluid distribution and material balance calculations has confirmed that the wells from these reservoirs have, in fact, been producing from the same accumulation thereby validating the new geological model. The new model has defined new opportunities of oil exploitation. Firstly, it has led to the drilling of 4 new wells and increased production by 4,500 STB/D. Secondly, it has indicated additional recovery opportunities in the form of drilling horizontal wells in the updip area. Finally, the new model indicates the existence of an aquifer of much lower strength than was previously thought. This has caused a revision in our reservoir management strategy and we now recommend water injection to supplement the aquifer support and enhance oil recovery.

  9. Synthesis and crystal structure of two new cerium rhodium oxides: Ce{sub 2/3-x}Rh{sup 3+}{sub 2}O{sub 4} (x{approx}0.12) with Ce mixed valency and Ce{sup 4+}Rh{sup 3+}{sub 2}O{sub 5}

    SciTech Connect (OSTI)

    Mizoguchi, Hiroshi; Zakharov, L.N.; Bhuvanesh, N.S.P.; Sleight, A.W.; Subramanian, M.A.

    2011-06-15

    The new compounds Ce{sub 2/3-x}Rh{sub 2}O{sub 4} (x{approx}0.11-0.14) and CeRh{sub 2}O{sub 5} have been prepared. Their structures were determined from single crystal X-ray diffraction data. Electrical and magnetic properties were also evaluated. Based on the structural analysis and physical properties, oxidation states for CeRh{sub 2}O{sub 5} can be assigned as Ce{sup 4+}Rh{sup 3+}{sub 2}O{sub 5}. A small variation in x was detected for Ce{sub 2/3-x}Rh{sub 2}O{sub 4} indicating a formula ranging from Ce{sup 3.64+}{sub 0.55}Rh{sup 3+}{sub 2}O{sub 4} to Ce{sup 3.81+}{sub 0.525}Rh{sup 3+}{sub 2}O{sub 4}. - Graphical abstract: The new compounds Ce{sub 2/3-x}Rh{sub 2}O{sub 4} (x{approx}0.11-0.14) and CeRh{sub 2}O{sub 5} have been prepared and their structures were determined from single crystal X-ray diffraction data. Electrical and magnetic properties were also evaluated. Highlights: > The new compounds CeRh{sub 2}O{sub 5} and Ce{sub 2/3-x}Rh{sub 2}O{sub 4} (x{approx}0.11-0.14) have been prepared. > Their structures were determined from single crystal X-ray diffraction data. > Valence picture is Ce{sup 4+}Rh{sup 3+}{sub 2}O{sub 5} and Ce{sup 3.64+}{sub 0.55}Rh{sup 3+}{sub 2}O{sub 4} to Ce{sup 3.81+}{sub 0.525}Rh{sup 3+}{sub 2}O{sub 4}.

  10. Assessment of environmental health and safety issues associated with the commercialization of unconventional gas recovery: Tight Western Sands

    SciTech Connect (OSTI)

    Riedel, E.F.; Cowan, C.E.; McLaughlin, T.J.

    1980-02-01

    Results of a study to identify and evaluate potential public health and safety problems and the potential environmental impacts from recovery of natural gas from Tight Western Sands are reported. A brief discussion of economic and technical constraints to development of this resource is also presented to place the environmental and safety issues in perspective. A description of the resource base, recovery techniques, and possible environmental effects associated with tight gas sands is presented.

  11. Temporal and spatial variability of ooid sand shoals: Comparison of Mississippian of Kentucky and Quaternary of Bahamas

    SciTech Connect (OSTI)

    Boardman, M.R. (Miami Univ., Oxford, OH (USA))

    1989-08-01

    An examination of the lithology and topography of Andros Island, Bahamas, reveals it is a Pleistocene ooid sand shoal. A comparison with Joulters Cays (a modern ooid sand shoal directly to the north) shows that much of the original depositional topography is preserved through at least one cycle of sea level highstand and lowstand. Both the Pleistocene and the Holocene ooid sand bodies are a few kilometers to tens of kilometers wide. The total vertical relief of a single episode of Quaternary ooid sand deposition is more than 10 m and includes accumulation in tidal channels, shallow flat areas, and eolian dunes. Today, much of Andros Island is within 2 m of present sea level and is the site of a belt several kilometers wide consisting of muddy tidal flat sediments overlying an exposure surface. The site of ooid sand deposition and shoal complex formation is not continuous along shorelines, especially windward margins, but shifts abruptly along the margins of platforms as a result of minor fluctuations of sea level. Thus, it should be expected that ooid sand shoals (ancient and modern) should be in direct lateral and vertical contact with lagoons, tidal flats, and reefs. The Mississippian Slade Formation contains many of the features of Quaternary ooid sand accumulation: abrupt vertical and lateral gradations between oolitic grainstones, packstones, and lime mudstones, vertical relief of individual oolitic sedimentary packages up to 30 m (perhaps with eolian dunes) and numerous exposure surfaces of varying intensities. These characteristics suggest that this formation represents a time of rapid fluctuations of relative sea level and abrupt shifts in the sites of ooid sand shoal complexes.

  12. Wall-Friction Support of Vertical Loads in Submerged Sand and Gravel Columns

    SciTech Connect (OSTI)

    Walton, O. R.; Vollmer, H. J.; Hepa, V. S.

    2015-08-25

    Laboratory studies of the ‘floor-loads’ under submerged vertical columns of sand and/or gravel indicate that such loads can be approximated by a buoyancy-corrected Janssen-silo-theory-like relationship. Similar to conditions in storage silos filled with dry granular solids, most of the weight of the sand or gravel is supported by wall friction forces. Laboratory measurements of the loads on the floor at the base of the water-filled columns (up to 25-diameters tall) indicate that the extra floor-load from the addition of the granular solid never exceeded the load that would exist under an unsupported (wide) bed of submerged sand or gravel that has a total depth corresponding to only two column-diameters. The measured floorloads reached an asymptotic maximum value when the depth of granular material in the columns was only three or four pipe-diameters, and never increased further as the columns were filled to the top (e.g. up to heights of 10 to 25 diameters). The floor-loads were stable and remained the same for days after filling. Aggressive tapping (e.g. hitting the containing pipe on the outside, manually with a wrench up and down the height and around the circumference) could increase (and occasionally decrease) the floor load substantially, but there was no sudden collapse or slumping to a state without significant wall friction effects. Considerable effort was required, repeatedly tapping over almost the entire column wall periphery, in order to produce floor-loads that corresponded to the total buoyancy-corrected weight of granular material added to the columns. Projecting the observed laboratory behavior to field conditions would imply that a stable floor-load condition, with only a slightly higher total floor pressure than the preexisting hydrostatic-head, would exist after a water-filled bore-hole is filled with sand or gravel. Significant seismic vibration (either a large nearby event or many micro-seismic events over an extended period) would likely

  13. Magnitude of the magnetic exchange interaction in the heavy-fermion antiferromagnet CeRhIn5

    SciTech Connect (OSTI)

    Das, Pinaki; Lin, S. -Z.; Ghimire, N. J.; Huang, K.; Ronning, F.; Bauer, E. D.; Thompson, J. D.; Batista, C. D.; Ehlers, G.; Janoschek, M.

    2014-12-08

    We have used high-resolution neutron spectroscopy experiments to determine the complete spin wave spectrum of the heavy-fermion antiferromagnet CeRhIn?. The spin wave dispersion can be quantitatively reproduced with a simple frustrated J?-J? model that also naturally explains the magnetic spin-spiral ground state of CeRhIn? and yields a dominant in-plane nearest-neighbor magnetic exchange constant J?=0.74(3) meV. Our results lead the way to a quantitative understanding of the rich low-temperature phase diagram of the prominent CeTIn? (T = Co, Rh, Ir) class of heavy-fermion materials.

  14. Magnitude of the magnetic exchange interaction in the heavy-fermion antiferromagnet CeRhIn5

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

    Das, Pinaki; Lin, S. -Z.; Ghimire, N. J.; Huang, K.; Ronning, F.; Bauer, E. D.; Thompson, J. D.; Batista, C. D.; Ehlers, G.; Janoschek, M.

    2014-12-08

    We have used high-resolution neutron spectroscopy experiments to determine the complete spin wave spectrum of the heavy-fermion antiferromagnet CeRhIn₅. The spin wave dispersion can be quantitatively reproduced with a simple frustrated J₁-J₂ model that also naturally explains the magnetic spin-spiral ground state of CeRhIn₅ and yields a dominant in-plane nearest-neighbor magnetic exchange constant J₀=0.74(3) meV. Our results lead the way to a quantitative understanding of the rich low-temperature phase diagram of the prominent CeTIn₅ (T = Co, Rh, Ir) class of heavy-fermion materials.

  15. SAND REPORT

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

    ... Slot ...... 20 9 . Bolt Termination Detail . . . . . . . . . . . . ... Faraday Cage 11 Non-metallic Plunger Bolt Metal Lid Metal Can Figure 2. Example ...

  16. Preparation of new morphological ZnO and Ce-doped ZnO

    SciTech Connect (OSTI)

    Chelouche, A.; Djouadi, D.; Aksas, A.

    2013-12-16

    ZnO micro-tori and cerium doped hexangulars ZnO have been prepared by the sol-gel method under methanol hypercritical conditions of temperature and pressure. X-ray diffraction (XRD) measurement has revealed the high crystalline quality and the nanometric size of the samples. Scanning electron microscopy (SEM) has shown that the ZnO powder has a torus-like shape while that of ZnO:Ce has a hexangular-like shape, either standing free or inserted into the cores of ZnO tori. Transmission electron microscopy (TEM) has revealed that the ZnO particles have sizes between 25 and 30 nm while Ce-doped ZnO grains have diameters ranging from 75 nm to 100 nm. Photoluminescence spectra at room temperature of the samples have revealed that the introduction of cerium in ZnO reduces the emission intensity lines, particularly the ZnO red and green ones.

  17. Reactivity and reaction intermediates for acetic acid adsorbed on CeO2(111)

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

    Calaza, Florencia C.; Chen, Tsung -Liang; Mullins, David R.; Xu, Ye; Steven H. Overbury

    2015-05-02

    Adsorption and reaction of acetic acid on a CeO2(1 1 1) surface was studied by a combination of ultra-highvacuum based methods including temperature desorption spectroscopy (TPD), soft X-ray photoelectronspectroscopy (sXPS), near edge X-ray absorption spectroscopy (NEXAFS) and reflection absorption IRspectroscopy (RAIRS), together with density functional theory (DFT) calculations. TPD shows that thedesorption products are strongly dependent upon the initial oxidation state of the CeO2 surface, includingselectivity between acetone and acetaldehyde products. The combination of sXPS and NEXAFS demon-strate that acetate forms upon adsorption at low temperature and is stable to above 500 K, above whichpoint ketene, acetone and acetic acidmore » desorb. Furthermore, DFT and RAIRS show that below 500 K, bridge bondedacetate coexists with a moiety formed by adsorption of an acetate at an oxygen vacancy, formed bywater desorption.« less

  18. Momentum-resolved photoemission of the Kondo peak in an ordered Ce-containing alloy

    SciTech Connect (OSTI)

    Garnier, M.; Purdie, D.; Breuer, K.; Hengsberger, M.; Baer, Y.

    1997-11-01

    A comparison of uv-photoemission spectra recorded from the surface alloys Pt(111)({radical}(3){times}{radical}(3))R30{degree}Ce and Pt(111)(2{times}2)La allows the contribution from the 4f electrons to be seen easily. The valence-band structure of these two surfaces is very similar, and the most obvious 4f contribution in high-resolution photoemission spectra of the Ce-containing alloy is the tail of the Kondo peak cut at E{sub F}. Within the limits of our measurement, no dispersion of this feature in the occupied regime is detected. The Kondo peak displays a marked intensity dependence on the emission angle, suggesting that hybridization is present in only a limited part of reciprocal space. The temperature dependence of this near-E{sub F} feature supports this interpretation. {copyright} {ital 1997} {ital The American Physical Society}

  19. Single to Multiquasiparticle Excitations in the Itinerant Helical Magnet CeRhIn5

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

    Stock, C.; Rodriguez-Rivera, J. A.; Schmalzl, K.; Rodriguez, E. E.; Stunault, A.; Petrovic, C.

    2015-06-19

    Neutron scattering is used to measure the quantum spin fluctuations in CeRhIn5 - the parent material of the eXIn5 superconducting series. Out-of-plane spin fluctuations are gapped and localized in momentum, similar to the spin excitons in CeCoIn5. The in-plane fluctuations consist of sharp spin-wave excitations parameterized by a nearest neighbor exchange JRKKY =0.88 ± 0.05 meV that crossover to a temporally and spatially broad multiparticle spectrum with energies of ~ 2 × JRKKY . This continuum represents composite fluctuations that illustrate the breakdown of single magnons originating from the delicate energy balance between localized 4f and itinerant behavior in amore » heavy metal. The experiment therefore shows how quasiparticle behavior is changed by the close proximity of quantum criticality.« less

  20. Reactivity and reaction intermediates for acetic acid adsorbed on CeO2(111)

    SciTech Connect (OSTI)

    Calaza, Florencia; Chen, Tsung-Liang; Mullins, David R; Xu, Ye; Overbury, Steven {Steve} H

    2015-01-01

    Adsorption and reaction of acetic acid on a CeO2(1 1 1) surface was studied by a combination of ultra-highvacuum based methods including temperature desorption spectroscopy (TPD), soft X-ray photoelectronspectroscopy (sXPS), near edge X-ray absorption spectroscopy (NEXAFS) and reflection absorption IRspectroscopy (RAIRS), together with density functional theory (DFT) calculations. TPD shows that thedesorption products are strongly dependent upon the initial oxidation state of the CeO2surface, includingselectivity between acetone and acetaldehyde products. The combination of sXPS and NEXAFS demon-strate that acetate forms upon adsorption at low temperature and is stable to above 500 K, above whichpoint ketene, acetone and acetic acid desorb. DFT and RAIRS show that below 500 K, bridge bondedacetate coexists with a moiety formed by adsorption of an acetate at an oxygen vacancy, formed bywater desorption.

  1. Single to Multiquasiparticle Excitations in the Itinerant Helical Magnet CeRhIn5

    SciTech Connect (OSTI)

    Stock, C.; Rodriguez-Rivera, J. A.; Schmalzl, K.; Rodriguez, E. E.; Stunault, A.; Petrovic, C.

    2015-06-19

    Neutron scattering is used to measure the quantum spin fluctuations in CeRhIn5 - the parent material of the eXIn5 superconducting series. Out-of-plane spin fluctuations are gapped and localized in momentum, similar to the spin excitons in CeCoIn5. The in-plane fluctuations consist of sharp spin-wave excitations parameterized by a nearest neighbor exchange JRKKY =0.88 ± 0.05 meV that crossover to a temporally and spatially broad multiparticle spectrum with energies of ~ 2 × JRKKY . This continuum represents composite fluctuations that illustrate the breakdown of single magnons originating from the delicate energy balance between localized 4f and itinerant behavior in a heavy metal. The experiment therefore shows how quasiparticle behavior is changed by the close proximity of quantum criticality.

  2. Synthesis of Transient Climate Evolution of the last 21-kyr (SynTraCE-21)

    SciTech Connect (OSTI)

    Zhengyu Liu

    2011-05-06

    Climate evolution in the last 21,000 years provides critical observations for testing state-of-the-art climate models on the simulation of climate evolution and abrupt climate changes. Proxy evidences and new modeling activities have led to rapid advances in our understanding of climate change for this past time period. This funding helps to support the first international SynTraCE-21k workshop at Mount Hood, Oregon from 10-13 October, 2010.

  3. DOE 10 CFR Part 429, Docket Number: EERE-2010-BT-CE-0014, RIN

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

    1904-AC23, Federal Register Vol. 76, No. 75, 21813-15 (Tuesday, April 19, 2011), Notice of Proposed Rule for Energy Conservation Program: Certification, Compliance, and Enforcement fo | Department of Energy Part 429, Docket Number: EERE-2010-BT-CE-0014, RIN 1904-AC23, Federal Register Vol. 76, No. 75, 21813-15 (Tuesday, April 19, 2011), Notice of Proposed Rule for Energy Conservation Program: Certification, Compliance, and Enforcement fo DOE 10 CFR Part 429, Docket Number:

  4. Investigation into Nanostructured Lanthanum Halides and CeBr{sub 3} for Nuclear Radiation Detection

    SciTech Connect (OSTI)

    Guss, P., Guise, R., Mukhopadhyay, S., Yuan, D.

    2011-06-22

    This slide-show presents work on radiation detection with nanostructured lanthanum halides and CeBr{sub 3}. The goal is to extend the gamma energy response on both low and high-energy regimes by demonstrating the ability to detect low-energy x-rays and relatively high-energy activation prompt gamma rays simultaneously using the nano-structured lanthanum bromide, lanthanum fluoride, cerium bromide, or other nanocrystal material. Homogeneous and nano structure cases are compared.

  5. Class I cultural resource overview for oil shale and tar sands areas in Colorado, Utah and Wyoming.

    SciTech Connect (OSTI)

    O'Rourke, D.; Kullen, D.; Gierek, L.; Wescott, K.; Greby, M.; Anast, G.; Nesta, M.; Walston, L.; Tate, R.; Azzarello, A.; Vinikour, B.; Van Lonkhuyzen, B.; Quinn, J.; Yuen, R.; Environmental Science Division

    2007-11-01

    In August 2005, the U.S. Congress enacted the Energy Policy Act of 2005, Public Law 109-58. In Section 369 of this Act, also known as the 'Oil Shale, Tar Sands, and Other Strategic Unconventional Fuels Act of 2005', Congress declared that oil shale and tar sands (and other unconventional fuels) are strategically important domestic energy resources that should be developed to reduce the nation's growing dependence on oil from politically and economically unstable foreign sources. The Bureau of Land Management (BLM) is developing a Programmatic Environmental Impact Statement (PEIS) to evaluate alternatives for establishing commercial oil shale and tar sands leasing programs in Colorado, Wyoming, and Utah. This PEIS evaluates the potential impacts of alternatives identifying BLM-administered lands as available for application for commercial leasing of oil shale resources within the three states and of tar sands resources within Utah. The scope of the analysis of the PEIS also includes an assessment of the potential effects of future commercial leasing. This Class I cultural resources study is in support of the Draft Oil Shale and Tar Sands Resource Management Plan Amendments to Address Land Use Allocations in Colorado, Utah, and Wyoming and Programmatic Environmental Impact Statement and is an attempt to synthesize archaeological data covering the most geologically prospective lands for oil shale and tar sands in Colorado, Utah, and Wyoming. This report is based solely on geographic information system (GIS) data held by the Colorado, Utah, and Wyoming State Historic Preservation Offices (SHPOs). The GIS data include the information that the BLM has provided to the SHPOs. The primary purpose of the Class I cultural resources overview is to provide information on the affected environment for the PEIS. Furthermore, this report provides recommendations to support planning decisions and the management of cultural resources that could be impacted by future oil shale and tar

  6. Remarkably robust and correlated coherence and antiferromagnetism in (Ce1-x Lax)Cu?Ge?

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

    Hodovanets, H.; Budko, S.? L.; Straszheim, W.? E.; Taufour, V.; Mun, E.? D.; Kim, H.; Flint, R.; Canfield, P.? C.

    2015-06-08

    We present magnetic susceptibility, resistivity, specific heat, and thermoelectric power measurements on (Ce1-x Lax)Cu?Ge? single crystals (0 ? x ? 1). With La substitution, the antiferromagnetic temperature TN is suppressed in an almost linear fashion and moves below 0.36 K, the base temperature of our measurements for x > 0.8. Surprisingly, in addition to robust antiferromagnetism, the system also shows low temperature coherent scattering below Tcoh up to ~ 0.9 of La, indicating a small percolation limit ~ 9% of Ce. Tcoh as a function of magnetic field was found to have different behavior for x more> 0.9. Remarkably, (Tcoh) at H = 0 was found to be linearly proportional to TN. The jump in the magnetic specific heat ?Cm at TN as a function of TK/TN for (Ce1-x Lax)Cu?Ge? follows the theoretical prediction based on the molecular field calculation for the S = 1/2 resonant level model.less

  7. Complex magnetism and strong electronic correlations in Ce2PdGe3

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

    Baumbach, R. E.; Gallagher, A.; Besara, T.; Sun, J.; Siegrist, T.; Singh, D. J.; Thompson, J. D.; Ronning, F.; Bauer, E. D.

    2015-01-05

    Single-crystal x-ray diffraction, magnetic susceptibility, magnetization, heat capacity, and electrical resistivity measurements are reported for the new tetragonal compound Ce2PdGe3, which forms in the space group P42/mmc (No. 131)—a relative of the α₋ThSi2-type structure. Measurements reveal a two-part antiferromagnetic phase transition at TN,1=10.7 K and TN,2=9.6 K and subsequent ferromagnetlike ordering near TC≈2.25 K. The ordered ground state emerges from a lattice of Ce ions that are hybridized with the conduction electrons, as revealed by the enhanced electronic coefficient of the specific heat γ≈50 mJ/mol-Ce-K2 (extrapolated to T=0 for T < TC). Lastly, electronic structure calculations reveal a Fermi surfacemore » that includes sheets with distinct nesting vectors. We find chemical/structural disorder also plays an important role, as evidenced by results from single-crystal x-ray diffraction, the width of the peaks in the heat capacity at TN and TC, and the small residual resistivity ratio RRR=ρ300K/ρ0=1.8.« less

  8. Adsorption and Reaction of C1-C3 Alcohols over CeOx(111) Thin Films

    SciTech Connect (OSTI)

    D Mullins; S Senanayake; T Chen

    2011-12-31

    This study reports the interaction of methanol, ethanol, 1-propanol, and 2-propanol with well-ordered CeO{sub 2}(111) thin film surfaces. All of the alcohols adsorb at low temperature by forming alkoxy and hydroxyl species on the surface. On fully oxidized CeO{sub 2}(111), recombination occurs between some of the alkoxys and hydroxyls, resulting in alcohol desorption near 220 K. At the same temperature, some of the surface hydroxyls disproportionate to produce water and the loss of lattice O. The remaining alkoxys react above 550 K. The primary alcohols favor dehydrogenation products (aldehydes). There is a net loss of O from the system, resulting in a reduction of the ceria. The secondary alcohol, 2-propanol, undergoes primarily dehydration, producing propene with no net change in the cerium oxidation state. Reduced CeO{sub x}(111) competes with the gaseous products for available O. Little or no water is produced. The reaction selectivity for the C{sub 2} and C{sub 3} alcohols shifts toward favoring dehydration products. The loss of O from the alcohols leads to oxidation of the reduced ceria. Compared with the oxidized surface, the alkene desorption shifts to lower temperature, whereas the aldehyde desorption shifts to higher temperature. This indicates that, on the reduced surface, it is easier to break the C-O bond but more difficult to break the O-substrate bond.

  9. Mesoporous MnCeOx solid solutions for low temperature and selective oxidation of hydrocarbons

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

    Zhang, Pengfei; Lu, Hanfeng; Zhou, Ying; Zhang, Li; Wu, Zili; Yang, Shize; Shi, Hongliang; Zhu, Qiulian; Chen, Yinfei; Dai, Sheng

    2015-10-15

    The development of noble-metal-free heterogeneous catalysts that can realize the aerobic oxidation of C–H bonds at low temperature is a profound challenge in the catalysis community. Here we report the synthesis of a mesoporous Mn0.5Ce0.5Ox solid solution that is highly active for the selective oxidation of hydrocarbons under mild conditions (100–120 °C). Notably, the catalytic performance achieved in the oxidation of cyclohexane to cyclohexanone/cyclohexanol (100 °C, conversion: 17.7%) is superior to those by the state-of-art commercial catalysts (140–160 °C, conversion: 3-5%). Finally, the high activity can be attributed to the formation of a Mn0.5Ce0.5Ox solid solution with an ultrahigh manganesemore » doping concentration in the CeO2 cubic fluorite lattice, leading to maximum active surface oxygens for the activation of C–H bonds and highly reducible Mn4+ ions for the rapid migration of oxygen vacancies from the bulk to the surface.« less

  10. Influence of Electron Doping on Magnetic Order in CeRu2Al10

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

    Kobayashi, Riki; Kaneko, Koji; Saito, Kotaro; Mignot, Jean-Michel; André, Gilles; Robert, Julien; Wakimoto, Shuichi; Matsuda, Masaaki; Chi, Songxue; Haga, Yoshinori; et al

    2014-09-17

    The effect of electron doping by the substitution of Rh for Ru on unconventional magnetic order in CeRu2Al10 was investigated via neutron powder diffraction. In Ce(Ru1-xRhx)2Al10 with x = 0.05, 0.12, and 0.2, reorientation of the ordered moment from the c- to the a-axis takes place in all samples, while the ordering vector q=(0 1 0) remains unchanged within this concentration range. The moment reorientation is accompanied by an enhancement in its size by a factor of ~2.4, from μ=0.43 μB at x=0 to μ =1.06, 1.04, and 1.02 μB for x=0.05, 0.12 and 0.2, respectively. The continuous decrease inmore » N´eel temperature T0(TN), despite an abrupt increase in μ , underlines the strong anisotropy in the exchange interaction in CeRu2Al10, and the fact that this anisotropy is easily suppressed by electron doping.« less

  11. Momentum-space structure of quasielastic spin fluctuations in Ce3Pd20Si6

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

    Portnichenko, P. Y.; Cameron, A. S.; Surmach, M. A.; Deen, Pascale P.; Paschen, S.; Prokofiev, A.; Mignot, Jean-Michel; Strydom, A. M.; Telling, Mark T. F.; Podlesnyak, Andrey A.; et al

    2015-01-01

    Surrounded by heavy-fermion metals, Ce3Pd20Si6 is one of the heaviest-electron systems known to date. Here we used high-resolution neutron spectroscopy to observe low-energy magnetic scattering from a single crystal of this compound in the paramagnetic state. We investigated its temperature dependence and distribution in momentum space, which was not accessible in earlier measurements on polycrystalline samples. At low temperatures, a quasielastic magnetic response with a half-width Γ ≈ 0.1 meV persists with varying intensity all over the Brillouin zone. It forms a broad hump centered at the (111) scattering vector, surrounded by minima of intensity at (002), (220), and equivalentmore » wave vectors. The momentum-space structure distinguishes this signal from a simple crystal-field excitation at 0.31 meV, suggested previously, and rather lets us ascribe it to short-range dynamical correlations between the neighboring Ce ions, mediated by the itinerant heavy f electrons via the Ruderman-Kittel-Kasuya-Yosida mechanism. With increasing temperature, the energy width of the signal follows the conventional T1/2 law, Γ(T)=Γ0+A√T. Lastly, the momentum-space symmetry of the quasielastic response suggests that it stems from the simple-cubic Ce sublattice occupying the 8c Wyckoff site, whereas the crystallographically inequivalent 4a site remains magnetically silent in this material.« less

  12. Accurate reservoir evaluation from borehole imaging techniques and thin bed log analysis: Case studies in shaly sands and complex lithologies in Lower Eocene Sands, Block III, Lake Maracaibo, Venezuela

    SciTech Connect (OSTI)

    Coll, C.; Rondon, L.

    1996-08-01

    Computer-aided signal processing in combination with different types of quantitative log evaluation techniques is very useful for predicting reservoir quality in complex lithologies and will help to increase the confidence level to complete and produce a reservoir. The Lower Eocene Sands in Block III are one of the largest reservoirs in Block III and it has produced light oil since 1960. Analysis of Borehole Images shows the reservoir heterogeneity by the presence of massive sands with very few shale laminations and thinnly bedded sands with a lot of laminations. The effect of these shales is a low resistivity that has been interpreted in most of the cases as water bearing sands. A reduction of the porosity due to diagenetic processes has produced a high-resistivity behaviour. The presence of bed boundaries and shales is detected by the microconductivity curves of the Borehole Imaging Tools allowing the estimation of the percentage of shale on these sands. Interactive computer-aided analysis and various image processing techniques are used to aid in log interpretation for estimating formation properties. Integration between these results, core information and production data was used for evaluating producibility of the reservoirs and to predict reservoir quality. A new estimation of the net pay thickness using this new technique is presented with the consequent improvement on the expectation of additional recovery. This methodology was successfully applied in a case by case study showing consistency in the area.

  13. Reduced coated-tubing failures cut costs at Dickinson Heath Sand Unit

    SciTech Connect (OSTI)

    Brus, K.R. )

    1990-03-01

    In the Dickinson Heath Sand Unit waterflood, corrosion-related failures of coated injection tubing began accelerating in 1979 with the increased water production attributed to waterflood response. The trend peaked in 1984 when $164,000 was spent pulling failed tubing (34 workovers). Starting in 1983, the selection of coatings, coating-application-process quality control, and handling/installation procedures were examined, modified, and refined. The author discusses how these changes and improvements resulted in fewer pulling jobs and less money spent on associated workovers during 1988.

  14. In situ heat treatment from multiple layers of a tar sands formation

    DOE Patents [OSTI]

    Vinegar, Harold J. (Bellaire, TX)

    2010-11-30

    A method for treating a tar sands formation is disclosed. The method includes providing a drive fluid to a first hydrocarbon containing layer of the formation to mobilize at least some hydrocarbons in the first layer. At least some of the mobilized hydrocarbons are allowed to flow into a second hydrocarbon containing layer of the formation. Heat is provided to the second layer from one or more heaters located in the second layer. At least some hydrocarbons are produced from the second layer of the formation.

  15. Western gas sands project. Status report, 1 July-31 July, 1980

    SciTech Connect (OSTI)

    Not Available

    1980-01-01

    The progress of the government-sponsored projects, directed towards increasing gas production from the low permeability gas sands of the western United States, is summarized. A subcontract was approved between Gas Research Institute and M.D. Wood, Inc. to obtain information on hydraulic fracture length. A meeting was held with Superior Oil Company during July to discuss possible sites for the multi-well experiment. Bartlesville Energy Technology Center continued work toward the assessment of fracture fluid effects on post fracture test times. A full report of the Seismic Formation Mapping Program will be issued by Sandia after review and editing have been completed.

  16. Geotechnical performance of a highway embankment constructed using waste foundry sand. Final report

    SciTech Connect (OSTI)

    Fox, P.J.; Mast, D.G.

    1998-11-23

    The purpose of this study was to evaluate the use of waste foundry sand (WFS) as a highway embankment material in a full-scale field demonstration project. This evaluation included geotechnical concerns, such as deformation, strength, hydraulic conductivity, and ease of construction. The report presents an introduction and previous research concerning WFS use in highway construction. A geotechnical laboratory testing program characterized the WFS used in the project, which was a waste product of Auburn Foundry, Inc., located in Auburn, Indiana. The project site was a 275 m section of the Country Route 206 highway project near Butler, Indiana.

  17. AVTA Federal Fleet PEV Readiness Data Logging and Characterization Study for NASA White Sands Test Facility

    SciTech Connect (OSTI)

    Stephen Schey; Jim Francfort

    2014-10-01

    This report focuses on the NASA White Sands Test Facility (WSTF) fleet to identify daily operational characteristics of select vehicles and report findings on vehicle and mission characterizations to support the successful introduction of plug-in electric vehicles (PEVs) into the agencies’ fleets. Individual observations of these selected vehicles provide the basis for recommendations related to electric vehicle adoption and whether a battery electric vehicle (BEV) or plug-in hybrid electric vehicle (PHEV) (collectively plug-in electric vehicles, or PEVs) can fulfill the mission requirements.

  18. Method of condensing vaporized water in situ to treat tar sands formations

    DOE Patents [OSTI]

    Hsu, Chia-Fu

    2010-03-16

    Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. Heat may be allowed to transfer from the heaters to at least a first portion of the formation. Conditions may be controlled in the formation so that water vaporized by the heaters in the first portion is selectively condensed in a second portion of the formation. At least some of the fluids may be produced from the formation.

  19. Western gas sands project. Status report, 1 June-30 June 1980

    SciTech Connect (OSTI)

    Not Available

    1980-01-01

    Progress of the government-sponsored projects during June 1980, that are directed towards increasing gas production from the low permeability gas sands of the western United States, is summarized. Northwest Exploration declined use of their site for the multi-well experiment; additional sites are being contemplated. Experiments began at Bartlesville Energy Technology Center designed to examine fracture closure and crushing strength of bauxite. At Lawrence Livermore Laboratory, work is progressing on the code to calculate fluid motion in an expanding propagation crack.

  20. 2575 Sand Hill Road * Mail Stop 103 * Menlo Park, CA 94025-7015

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

    575 Sand Hill Road * Mail Stop 103 * Menlo Park, CA 94025-7015 650-926-2288 * Fax 650-926-4695 SLAC is operated by Stanford University for the U.S. Department of Energy SLAC National Accelerator Laboratory LCLS Users' Newsletter, Issue 1, April 8, 2009 Dear Colleagues: We would like to present to you the first issue of the LCLS Users' Newsletter. We are pleased to report that we have recruited Henia Kamil as the LCLS User Research Administrator Manager. Please join me in welcoming Henia and feel

  1. Emission properties and back-bombardment for CeB{sub 6} compared to LaB{sub 6}

    SciTech Connect (OSTI)

    Bakr, Mahmoud; Kawai, M.; Kii, T.; Zen, H.; Masuda, K.; Ohgaki, H.

    2015-02-14

    The emission properties of CeB{sub 6} compared to LaB{sub 6} thermionic cathodes have been measured using an electrostatic DC gun. Obtaining knowledge of the emission properties is the first step in understanding the back-bombardment effect that limits wide usage of thermionic radio-frequency electron guns. The effect of back-bombardment electrons on CeB{sub 6} compared to LaB{sub 6} was studied using a numerical simulation model. The results show that for 6 μs pulse duration with input radio-frequency power of 8 MW, CeB{sub 6} should experience 14% lower temperature increase and 21% lower current density rise compared to LaB{sub 6}. We conclude that CeB{sub 6} has the potential to become the future replacement for LaB{sub 6} thermionic cathodes in radio-frequency electron guns.

  2. Investigation of chemical composition and crystal structure in sintered Ce{sub 15}Nd{sub 15}Fe{sub bal}B{sub 1} magnet

    SciTech Connect (OSTI)

    Huang, Shu-lin; Feng, Hai-bo; Zhu, Ming-gang; Li, An-hua; Li, Wei; Zhang, Yue

    2014-10-15

    The substitution of cerium, a more abundant rare-earth element, for sintered Nd-Fe-B magnets has drawn intense interest. In the present work, nominal composition of Ce{sub 15}Nd{sub 15}Fe{sub bal}B{sub 1} (wt. %), with cerium constitutes increased to 50% of the total rare-earth content, was used. And Ce-free Nd{sub 30}Fe{sub bal}B{sub 1} (wt. %) was prepared by the same preparation process as comparison. The microstructure of the sintered magnets has been investigated by means of X-ray diffraction and transmission electron microscope. The results show that there are three kinds of RE-rich phases in the same magnet, i.e., fcc-(Ce,Nd)O{sub x} (a=0.547nm), hcp-(Ce,Nd){sub 2}O{sub 3} (a=0.386nm, c=0.604nm) and bcc-(Ce,Nd){sub 2}O{sub 3} (a=1.113nm). Ors of (140)(Ce,Nd){sub 2}Fe{sub 14}B// (1-21)bcc-(Ce,Nd){sub 2}O{sub 3}(∼3°), [001](Ce,Nd){sub 2}Fe{sub 14}B// [-214]bcc-(Ce,Nd){sub 2}O{sub 3}; (01-1)(Ce,Nd){sub 2}Fe{sub 14}B// (101)fcc- (Ce,Nd)O{sub x}(∼2°), [101](Ce,Nd){sub 2}Fe14B// [12-1]fcc-(Ce,Nd)O{sub x} were found through selected area electron diffraction (SAED) analysis. According to the analysis, it can be concluded that cerium has partly substituted for neodymium by occupying the corresponding atom sites in the Ce{sub 15}Nd{sub 15}Fe{sub bal}B{sub 1} magnet, without changing the crystal configuration.

  3. Effect of oxygen vacancy on half metallicity in Ni-doped CeO{sub 2} diluted magnetic semiconductor

    SciTech Connect (OSTI)

    Saini, Hardev S. Saini, G. S. S.; Singh, Mukhtiyar; Kashyap, Manish K.

    2015-05-15

    The electronic and magnetic properties of Ni-doped CeO{sub 2} diluted amgentic semiconductor (DMS) including the effect of oxygen vacancy (V{sub o}) with doping concentration, x = 0.125 have been calculated using FPLAPW method based on Density Functional Theory (DFT) as implemented in WIEN2k. In the present supercell approach, the XC potential was constructed using GGA+U formalism in which Coulomb correction is applied to standard GGA functional within the parameterization of Perdew-Burke-Ernzerhof (PBE). We have found that the ground state properties of bulk CeO{sub 2} compound have been modified significantly due to the substitution of Ni-dopant at the cation (Ce) site with/without V{sub O} and realized that the ferromagnetism in CeO{sub 2} remarkably depends on the V{sub o} concentrations. The presence of V{sub o}, in Ni-doped CeO{sub 2}, can leads to strong ferromagnetic coupling between the nearest neighboring Ni-ions and induces a HMF in this compound. Such ferromagnetic exchange coupling is mainly attributed to spin splitting of Ni-d states, via electrons trapped in V{sub o}. The HMF characteristics of Ni-doped CeO{sub 2} including V{sub o} makes it an ideal material for spintronic devices.

  4. Kondo behavior, ferromagnetic correlations, and crystal fields in the heavy Fermion compounds Ce3X (X=In, Sn)

    SciTech Connect (OSTI)

    Wang, C. H.; Lawrence, J. M.; Christianson, Andrew D; Goremychkin, E. A.; Fanelli, V. R.; Gofryk, K.; Bauer, E. D.; Ronning, F.; Thompson, J. D.; De Souza, N. R.; Kolesnikov, Alexander I

    2010-01-01

    We report measuerments of the inelastic neutron scattering, the magnetic susceptibility, the magnetization, and the magnetic field dependence of the specific heat for the heavy Fermion compounds Ce3In and Ce3Sn. The neutron scattering results show that the excited crystal field levels have energies E1=13.2 meV, E2-44.8 meV for Ce3In and E1=18.5 meV, E2=36.1 meV for Ce3Sn. The Kondo temperature deduced from the quasielastic linewidth is 17 K for Ce3In and 40 K for Ce3Sn. The low temperature behavior of teh specific heat, magnetization, and susceptibility can not be well-described by J=1.2 Kondo physics alone, but require calculations that include contributions from the Kondo effect, broadened crystal fields, and ferromagnetic correlations, all of which are known to be important in these compounds. We find that the ferromagnetic fluctuation makes a 10-15% contribution to the ground state entropy and magnetization. The large in this heavy Fermion system thus arises more from the ferromagnetic correlations than from the Kondo behavior.

  5. Soft chemistry synthesis of high-crystalline orthogermanate CeGeO{sub 4}: A new photocatalyst

    SciTech Connect (OSTI)

    Xing Jun; Yang Chen; Li Weikun; Gong Xueqing; Yang Huagui

    2013-01-15

    A new orthogermanate phase of CeGeO{sub 4} was studied and the corresponding nanocrystals have been successfully synthesized via a facile hydrothermal method without adding any capping agent. The pH value of the solution and the reaction time were also further investigated, respectively. The as-prepared CeGeO{sub 4} nanocrystals with a uniform size of 15 nm have been characterized by using XRD/TEM/TGA/UV-vis techniques, and their electronic structures and band gap were calculated based on a plane wave density function theory (DFT). The promising photocatalytic properties of CeGeO{sub 4} have been confirmed through monitoring reactive oxidative species generated in photocatalytic reactions of terephthalic acid as a fluorescence probe. - Graphical Abstract: A novel photocatalyst CeGeO{sub 4} was prepared. Highlights: Black-Right-Pointing-Pointer CeGeO{sub 4} as a novel photocatalyst was successfully synthesized by a hydrothermal method. Black-Right-Pointing-Pointer Electronic structure and band gap were calculated based on DFT. Black-Right-Pointing-Pointer CeGeO{sub 4} exhibited a promising photocatalytic performance.

  6. High thermoelectric performance of In, Yb, Ce multiple filled CoSb{sub 3} based skutterudite compounds

    SciTech Connect (OSTI)

    Ballikaya, Sedat; Department of Physics, University of Michigan, Ann Arbor, MI, 48109 ; Uzar, Neslihan; Yildirim, Saffettin; Salvador, James R.; Uher, Ctirad

    2012-09-15

    Filling voids with rare earth atoms is an effective way to lowering thermal conductivity which necessarily enhances thermoelectric properties of skutterudite compounds. Yb atom is one of the most effective species among the rare earth atoms for filling the voids in the skutterudite structure due to a large atomic mass, radius and it is intermediate valence state. In this work, we aim to find the best filling partners for Yb using different combinations of Ce and In as well as to optimize actual filling fraction in order to achieve high values of ZT. The traditional method of synthesis relying on melting-annealing and followed by spark plasma sintering was used to prepare all samples. The thermoelectric properties of four samples of Yb{sub 0.2}In{sub 0.2}Co{sub 4}Sb{sub 12}, Yb{sub 0.2}Ce{sub 0.15}Co{sub 4}Sb{sub 12}, Yb{sub 0.2}Ce{sub 0.15}In{sub 0.2}Co{sub 4}Sb{sub 12}, and Yb{sub 0.3}Ce{sub 0.15}In{sub 0.2}Co{sub 4}Sb{sub 12} (nominal) were examined based on the Seebeck coefficient, electrical conductivity, thermal conductivity, and Hall coefficient. Hall coefficient and Seebeck coefficient signs confirm that all samples are n-type skutterudite compounds. Carrier density increases with the increasing Yb+Ce content. A high power factor value of 57.7 {mu}W/K{sup 2}/cm for Yb{sub 0.2}Ce{sub 0.15}Co{sub 4}Sb{sub 12} and a lower thermal conductivity value of 2.82 W/m/K for Yb{sub 0.2}Ce{sub 0.15}In{sub 0.2}Co{sub 4}Sb{sub 12} indicate that small quantities of Ce with In may be a good partner to Yb to reduce the thermal conductivity further and thus enhance the thermoelectric performance of skutterudites. The highest ZT value of 1.43 was achieved for Yb{sub 0.2}Ce{sub 0.15}In{sub 0.2}Co{sub 4}Sb{sub 12} triple-filled skutterudite at 800 K. - Graphical abstract: Thermoelectric figure of merit of Yb{sub x}In{sub y}Ce{sub z}Co{sub 4}Sb{sub 12} (0{<=}x,y,z{<=}0.18 actual) compounds versus temperature. Highlights: Black-Right-Pointing-Pointer TE properties of Yb,In,Ce

  7. Mineral Dissolution and Secondary Precipitation on Quartz Sand in Simulated Hanford Tank Solutions Affecting Subsurface Porosity

    SciTech Connect (OSTI)

    Wang, Guohui; Um, Wooyong

    2012-11-23

    Highly alkaline nuclear waste solutions have been released from underground nuclear waste storage tanks and pipelines into the vadose zone at the U.S. Department of Energys Hanford Site in Washington, causing mineral dissolution and re-precipitation upon contact with subsurface sediments. High pH caustic NaNO3 solutions with and without dissolved Al were reacted with quartz sand through flow-through columns stepwise at 45, 51, and 89C to simulate possible reactions between leaked nuclear waste solution and primary subsurface mineral. Upon reaction, Si was released from the dissolution of quartz sand, and nitrate-cancrinite [Na8Si6Al6O24(NO3)2] precipitated on the quartz surface as a secondary mineral phase. Both steady-state dissolution and precipitation kinetics were quantified, and quartz dissolution apparent activation energy was determined. Mineral alteration through dissolution and precipitation processes results in pore volume and structure changes in the subsurface porous media. In this study, the column porosity increased up to 40.3% in the pure dissolution column when no dissolved Al was present in the leachate, whereas up to a 26.5% porosity decrease was found in columns where both dissolution and precipitation were observed because of the presence of Al in the input solution. The porosity change was also confirmed by calculation using the dissolution and precipitation rates and mineral volume changes.

  8. Self-Shielding Correlation of Foil Activation Neutron Spectra Analysis by SAND-II.

    Energy Science and Technology Software Center (OSTI)

    2008-11-21

    Version 00 SELFS-3 corrects for the influence of the self-shielding effect in neutron spectrum determinations by means of the multifoil activation method. It is used in combination with the SAND-II program for unfolding the responses of an irradiated set of activation detectors in 620 groups. The program SELFS can calculate a corrected 620 group cross section data set for specified reactions used in the SAND-II library, and for specified foil thicknesses. This procedure requires nomore » additional assumption on the shape of the neutron spectrum and on other experimental conditions, but only some foil characteristics (reaction type, material composition, foil thickness). Application of this procedure is possible when multigroup unfolding programs are used with suitably small energy intervals. This code system was developed in the 1970’s at Reactor Centrum Nederland, Petten, The Netherlands, and was contributed to RSICC through the NEA Data Bank. No changes were made to the package when it was released by RSICC in 2008. Modifications will be required to run SELFS-3 on current computer systems.« less

  9. Performance and operation of the Hamm Minnelusa Sand Unit, Campbell County, Wyoming

    SciTech Connect (OSTI)

    Doll, T.E.; Hanson, M.T.

    1987-12-01

    The Hamm Minnelusa Sand Unit was discovered in 1966 and produced from the Minnelusa B sand. The field was under fluid-expansion primary recovery until water injection began in Dec. 1972. Waterflood response peaked at a higher monthly rate than that of primary recovery. Water production indicated channeling through high-permeability zones. In Oct. 1975, a volumetric-sweep improvement program was initiated into the single-injection wellbore. Anionic polyacrylamide and aluminum citrate were injected to provide in-depth vertical conformance. A second well was converted to injection in April 1976, and sweep improvement started 26 months later. The third well was converted to injection and the chemical-oil-recovery program began in Aug. 1982. The first two injectors were converted to produce water disposal at that date. The polymer-augmented waterflood was terminated in Jan. 1985. Water injection continues. This paper details flood performance up to July, 1985. Cumulative water injection is 76.6% of the total PV. A 39.5% PV chemical slug has been injected. Total recovery to data is 48.7% of the original oil in place (OOIP).

  10. Model for the formation of longshore sand ridges on the continental shelf

    SciTech Connect (OSTI)

    Restrepo, J.M.; Bona, J.L.

    1994-01-05

    A model is proposed for the formation and evolution of three- dimensional sedimentary structures such as longshore sand ridges on the continental shelf in water deeper than that of the shoaling region. Owing to the striking similarity between the bar spacing and the length scales in which interactions among the most energetic modes of shallow water waves take place, we argue that these bars are formed slowly by flows in the turbulent boundary layer generated by weakly nonlinear, dispersive waves. Hence the model is based on the interaction between surficial, weakly nonlinear shallow water waves, having weak spanwise spatial dependence, and the bottom topography. While such underwater structures are not the result of a single formative agent, it is argued that the mechanism proposed in this study does contribute significantly to their generation and evolution. Comparisons of this model with oceanographic data must wait for sufficient data to become available. In conjunction with developing the sand ridge model, this study proposes new mathematical equations of interest in their own right.

  11. Oil shale, tar sand, coal research, advanced exploratory process technology, jointly sponsored research

    SciTech Connect (OSTI)

    Not Available

    1992-01-01

    Progress made in five research programs is described. The subtasks in oil shale study include oil shale process studies and unconventional applications and markets for western oil shale.The tar sand study is on recycle oil pyrolysis and extraction (ROPE) process. Four tasks are described in coal research: underground coal gasification; coal combustion; integrated coal processing concepts; and sold waste management. Advanced exploratory process technology includes: advanced process concepts; advanced mitigation concepts; and oil and gas technology. Jointly sponsored research covers: organic and inorganic hazardous waste stabilization; CROW field demonstration with Bell Lumber and Pole; development and validation of a standard test method for sequential batch extraction fluid; PGI demonstration project; operation and evaluation of the CO[sub 2] HUFF-N-PUFF process; fly ash binder for unsurfaced road aggregates; solid state NMR analysis of Mesaverde group, Greater Green River Basin, tight gas sands; flow-loop testing of double-wall pipe for thermal applications; shallow oil production using horizontal wells with enhanced oil recovery techniques; NMR analysis of sample from the ocean drilling program; and menu driven access to the WDEQ hydrologic data management system.

  12. Lattice, Ce-L{sub 3}valence, transport, and magnetic results on mixed-valent/Kondo system Ce{sub 1{minus}x}La{sub x}Mn{sub 2}Si{sub 2}

    SciTech Connect (OSTI)

    Liang, G.; Xi, H.; Roberts, E.; Binford, T.; Mochizuki, K.; Markert, J.T.; Croft, M.

    1997-04-01

    Lattice, Ce-L{sub 3} edge, resistivity, and magnetic susceptibility measurements have been carried out on the polycrystalline Ce{sub 1{minus}x}La{sub x}Mn{sub 2}Si{sub 2} system (0{le}x{le}1) to study the interplay between Mn 3d-host magnetism and Kondo-type Ce-spin fluctuations. As x increases, the system varies gradually from a Ce mixed-valent system with 3d-host antiferromagnetism (at x=0) to a nearly trivalent system with strong 3d-host ferromagnetism (near x=1). In the antiferromagnetic (AF) phase region (0{le}x{le}0.5), the Neel temperature T{sub N} decreases with the increase of x, manifesting the weakening of the host AF field. Impurity Kondo behavior is observed at x=0.05, indicating that the low-temperature coherence state in CeMn{sub 2}Si{sub 2} can be destroyed by {open_quotes}Kondo holes{close_quotes} which are created by very small substitution of La for Ce. The susceptibility and resistivity results suggest that the impurity Kondo effect in the 0.1{le}x{le}0.5 samples is partially suppressed by a nonvanishing ferromagnetic (FM) field component; whereas the phononlike behavior of the resistivity curves in the Mn-host FM-phase region (0.5{lt}x{le}1.0) supports our previous proposal that the Kondo-type Ce-spin fluctuations can be effectively quenched by a strong 3d-host FM field. {copyright} {ital 1997 American Institute of Physics.}

  13. The effects of interim flow operations from Glen Canyon Dam on Colorado River sand bars in the Grand Canyon, Arizona

    SciTech Connect (OSTI)

    Kaplinski, M.A.; Hazel, J.E.; Beus, S.S. . Geology Dept.); Stevens, L.E. . NPS Cooperative Parks Studies Unit); Mayes, H.B. )

    1993-04-01

    Discharges from Glen Canyon Dam (GCD) affect the geomorphology and stability of downstream alluvial sediment deposits. To protect downstream resources, the US DOI mandated interim flow criteria (IFC) on 1 August, 1991. The IFC consist of reduced daily fluctuations (226--566 m[sup 3]/s) and reduced ramping rates (42.5--57 m[sup 3]/s/hr), the primary objective of which is to maintain sediment storage in the river system by minimizing sediment transport. This study was initiated to determine the effectiveness of the IFC in achieving this objective. The authors examined whether reduced daily fluctuations lead to subaerial sand bar erosion and increased subaqueous sediment storage. They collected and analyzed topographic and bathymetric survey data from sand bars throughout the Colorado River corridor in Sept/Oct, 1991 and in Oct/Nov, 1992 to compare changes in sand bar morphology. They examined changing topography due to GCD operation in what they termed the hydrologically active zone (HAZ), that portion of the sand bar exposed to daily dam operations (142--900 m[sup 3]/s stage elevations). Volumes within the HAZ and profiles across this zone were generated from these sediment deposits. Their preliminary results show that, in general, erosion of sediment at higher bar elevations was coincident with deposition along lower parts of the bar platform. The observed response to IFC elevation in order to maintain sediment deposits for Colorado River corridor bio-diversity (e.g., fisheries habitats). 88% of sand bars that showed significant volume gain were preceded by significant volume loss, implying that antecedent conditions are an important factor in sand bar response to GCD operations. Sediment transport capacity was reduced as evidenced by increased sediment storage in recirculation zones and sediment infilling of eddy return channels. The authors conclude that IFC are achieving their primary objective of maintaining sediment storage within the river corridor.

  14. Optical properties of {gamma}- and {alpha}-Ce by spectroscopic ellipsometry

    SciTech Connect (OSTI)

    Joo Yull, Rhee

    1992-07-20

    A rotating analyzer type ellipsometer with an ultra high vacuum sample chamber was built. The dielectric functions of {gamma}- and {alpha}-Ce were measured in the energy range from 1.5 to 5.4 eV to investigate the role of the 4f electron in the isostructural phase transition. {gamma}- and {alpha}-Ce were made by evaporation of Ce on sapphire substrates at room temperature and 25 K. All measurements were performed inside a UHV chamber at pressures lower than l {times} 10{sup {minus}10}Torr. The measured dielectric functions showed a thickness dependence. The thicker sample has the smaller optical conductivities. Both overlayer thickness and void fraction increase as sample thickness increases. Repeating cooling-heating-cooling or heating-cooling-heating cycles causes the sample surface to become rougher but the relative volume fractions of both phases and the void fraction in the bulk remain unchanged. The optical conductivity increases upon entering the a-phase but the number of electrons per atom, N{sub eff}/N{sub A}, contributing to the optical conductivity does not change. The valence electrons lose oscillator strength in the above energy range due to volume collapse. This reduces N{sub eff}/NA but the increased 4f-sd valence band hybridization exactly compensates the reduced oscillator strength. Therefore the net effects of the {gamma}{yields}{alpha} isostructural phase transition are an increase of optical conductivity and constancy of N{sub eff}/N{sub A}.

  15. Surface-structure sensitivity of CeO2 nanocrystals in photocatalysis and enhancing the reactivity with nanogold

    SciTech Connect (OSTI)

    Lei, Wanying; Zhang, Tingting; Gu, Lin; Liu, Ping; Rodriguez, José A.; Liu, Gang; Liu, Minghua

    2015-06-19

    Structure–function correlations are a central theme in heterogeneous (photo)catalysis. In this research, using aberration-corrected scanning transmission electron microscopy (STEM), the atomic surface structures of well-defined one-dimensional (1D) CeO2 nanorods (NRs) and 3D nanocubes (NCs) are directly visualized at subangstrom resolution. CeO2 NCs predominantly expose the {100} facet, with {110} and {111} as minor cutoff facets at the respective edges and corners. Notably, the outermost surface layer of the {100} facet is nearly O-terminated. Neither surface relaxations nor reconstructions on {100} are observed, indicating unusual polarity compensation, which is primarily mediated by near-surface oxygen vacancies. The surface of CeO2 NRs is highly stepped, with the enclosed {110} facet exposing Ce cations and O anions on terraces. On the basis of STEM profile-view imaging and electronic structure analysis, the photoreactivity of CeO2 nanocrystals toward aqueous methyl orange degradation under UV is revealed to be surface-structure-sensitive, following the order: {110} >> {100}. The underlying surface-structure sensitivity can be attributed to the variation in low-coordinate surface cerium cations between {110} and {100} facets. To further enhance light absorption, Au nanoparticles (NPs) are deposited on CeO2 NRs to form Au/CeO2 plasmonic nanocomposites, which dramatically promotes the photoreactivity that is Au particle size- and excitation light wavelength-dependent. The mechanisms responsible for the enhancement of photocatalytic activity are discussed, highlighting the crucial role of photoexcited charge carrier transfer.

  16. Kondo-lattice behavior and multiple characteristic temperatures in CeIr{sub 2}Ge{sub 2}

    SciTech Connect (OSTI)

    Mallik, R.; Sampathkumaran, E.V.; Paulose, P.L.; Dumschat, J.; Wortmann, G.

    1997-02-01

    The results of electrical-resistivity {rho} measurements (1.4{endash}300 K) on the alloys, Ce{sub 1{minus}x}La{sub x}Ir{sub 2}Ge{sub 2} (0{le}x{le}1), CeIr{sub 2{minus}x}(Rh,Pt){sub x}Ge{sub 2} (x=0.2 and 0.4), and CeIr{sub 2}Ge{sub 2{minus}x}(Si,Sn){sub x} (x=0.2 and 0.4), are reported in order to understand the Kondo effect in CeIr{sub 2}Ge{sub 2}. There is a significant decrease in {rho} as the temperature is lowered from 100 to 4.2 K for x = 0.0. This feature disappears for a small replacement of Ce by La (x = 0.3), thereby resulting in a single-ion Kondo effect for higher values of x. This finding establishes that the temperature T{sub coh}, characterizing the coherent scattering among the Kondo centers for x=0 is as large as about 100 K. The coherent scattering is not destroyed by small substitutions at the Ir or Ge site. The observed sensitivity of this coherence effect to a small disruption of Ce sublattice periodicity alone by La substitution is uncommon among trivalent Ce alloys. Such a large T{sub coh} value enables us to emphasize the need to invoke three characteristic temperatures for nonmagnetic Kondo lattices. {copyright} {ital 1997} {ital The American Physical Society}

  17. Surface-structure sensitivity of CeO2 nanocrystals in photocatalysis and enhancing the reactivity with nanogold

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

    Lei, Wanying; Zhang, Tingting; Gu, Lin; Liu, Ping; Rodriguez, José A.; Liu, Gang; Liu, Minghua

    2015-06-19

    Structure–function correlations are a central theme in heterogeneous (photo)catalysis. In this research, using aberration-corrected scanning transmission electron microscopy (STEM), the atomic surface structures of well-defined one-dimensional (1D) CeO2 nanorods (NRs) and 3D nanocubes (NCs) are directly visualized at subangstrom resolution. CeO2 NCs predominantly expose the {100} facet, with {110} and {111} as minor cutoff facets at the respective edges and corners. Notably, the outermost surface layer of the {100} facet is nearly O-terminated. Neither surface relaxations nor reconstructions on {100} are observed, indicating unusual polarity compensation, which is primarily mediated by near-surface oxygen vacancies. The surface of CeO2 NRs ismore » highly stepped, with the enclosed {110} facet exposing Ce cations and O anions on terraces. On the basis of STEM profile-view imaging and electronic structure analysis, the photoreactivity of CeO2 nanocrystals toward aqueous methyl orange degradation under UV is revealed to be surface-structure-sensitive, following the order: {110} >> {100}. The underlying surface-structure sensitivity can be attributed to the variation in low-coordinate surface cerium cations between {110} and {100} facets. To further enhance light absorption, Au nanoparticles (NPs) are deposited on CeO2 NRs to form Au/CeO2 plasmonic nanocomposites, which dramatically promotes the photoreactivity that is Au particle size- and excitation light wavelength-dependent. The mechanisms responsible for the enhancement of photocatalytic activity are discussed, highlighting the crucial role of photoexcited charge carrier transfer.« less

  18. Structure and magnetic properties of Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15}, a new 10H-polytype in the Ba-Ce-Mn-O system

    SciTech Connect (OSTI)

    Macias, Mario A.; Mentre, Olivier; Cuello, Gabriel J.; Gauthier, Gilles H.

    2013-02-15

    Based on the peculiar magnetic properties that are observed in pseudo one-dimensional manganites, we decided to synthesize the new Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15} compound. The preparation was performed by solid state reaction in air at about 1350 Degree-Sign C, for which we found that the compound crystallizes in a hexagonal symmetry with space group P6{sub 3}/mmc (No-194) and cell parameters a=b=5.7861(2) A and c=23.902(1) A. The structural description was correlated with neutron diffraction and bond valence calculations, confirming the presence of Ce{sup 4+} and Mn{sup 4+} segregated in the different crystallographic positions. Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15} displays evidence for strong AFM couplings already set at room temperature. The main arrangement of Mn{sup 4+} in magnetically isolated tetramers of face-sharing octahedra is responsible for a metamagnetic-like transition around 50 K. - Graphical abstract: The new Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15} polytype shows strong AFM couplings in magnetically isolated [Ce{sub 0.25}Mn{sub 3.75}O{sub 15}] tetramers of face-sharing octahedral, resulting in a metamagnetic-like transition around 50 K. Highlights: Black-Right-Pointing-Pointer Ba{sub 5}Ce{sub 1.25}Mn{sub 3.75}O{sub 15}, a new 10H polytype, has been prepared in the Ba-Ce-Mn-O system. Black-Right-Pointing-Pointer The compound crystallizes in the P6{sub 3}/mmc space group with (cchhh){sub 2} stacking sequence. Black-Right-Pointing-Pointer [Ce{sub 0.25}Mn{sub 3.75}O{sub 15}] tetramers are separated by [CeO{sub 6}] octahedra in the structure. Black-Right-Pointing-Pointer Instead of robust AFM ordering, a metamagnetic-like transition is found around 50 K.

  19. Analysis of FEL-based CeC amplification at high gain limit

    SciTech Connect (OSTI)

    Wang, G.; Litvinenko, V.; Jing, Y.

    2015-05-03

    An analysis of Coherent electron Cooling (CeC) amplifier based on 1D Free Electron Laser (FEL) theory was previously performed with exact solution of the dispersion relation, assuming electrons having Lorentzian energy distribution. At high gain limit, the asymptotic behavior of the FEL amplifier can be better understood by Taylor expanding the exact solution of the dispersion relation with respect to the detuning parameter. In this work, we make quadratic expansion of the dispersion relation for Lorentzian energy distribution and investigate how longitudinal space charge and electrons’ energy spread affect the FEL amplification process.

  20. Disorder and size effects on Kondo interactions and magneticcorrelations in CePt2 nanoscrystals

    SciTech Connect (OSTI)

    Chen, Y.Y.; Huang, P.H.; Ou, M.N.; Wang, C.R.; Yao, Y.D.; Lee,T.K.; Ho, M.Y.; Lawrence, J.M.; Booth, C.H.

    2006-12-12

    The evolution of the Kondo effect and magnetic correlations with size reduction in CePt{sub 2} nanoparticles (3.1-26 nm) is studied by analysis of the temperature-dependent specific heat and magnetic susceptibility. The antiferromagnetic correlations diminish with size reduction. The Kondo effect predominates at small particle size with trivalent, small Kondo temperature (T{sub K}) magnetic regions coexisting with strongly mixed valent, large T{sub K} nonmagnetic regions. We discuss the role of structural disorder, background density of states and the electronic quantum size effect on the results.

  1. Nanostructured LaF{sub 3}:Ce Quantum Dot Nuclear Radiation Detector

    SciTech Connect (OSTI)

    Guss, P., Guise, R., Reed, M., Mukhopadhyay, S., Yuan, D.

    2010-11-01

    Many radioactive isotopes have low energy X-rays and high energy gamma rays of interest for detection. The goal of the work presented was to demonstrate the possibility of measuring both low-energy X-rays and relatively high-energy gamma rays simultaneously using the nano-structured lanthanum bromide, lanthanum fluoride, or cerium bromide. The key accomplishments of the project was the building and acquisition of the LaF3:Ce nanocomposite detectors. Nanocomposite detectors are sensitive to {gamma}s as well as ns and X-rays.

  2. High-pressure, transport, and thermodynamic properties of CeTe3

    SciTech Connect (OSTI)

    Zocco, D.A.

    2010-02-24

    We have performed high-pressure, electrical resistivity, and specific heat measurements on CeTe3 single crystals. Two magnetic phases with nonparallel magnetic easy axes were detected in electrical resistivity and specific heat at low temperatures. We also observed the emergence of an additional phase at high pressures and low temperatures and a possible structural phase transition detected at room temperature and at 45 kbar, which can possibly be related with the lowering of the charge-density wave transition temperature known for this compound.

  3. DOE 10 CFR Parts 430 and 431, Docket No. EERE-2010-BT-CE-0014 RIN

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

    1904-AC23, Federal Register Vol. 75, No. 88, 25121-24 (Friday, May 7, 2010), Revisions to Energy Efficiency Enforcement Regulations, Request for Information (RFI);request for comm | Department of Energy Parts 430 and 431, Docket No. EERE-2010-BT-CE-0014 RIN 1904-AC23, Federal Register Vol. 75, No. 88, 25121-24 (Friday, May 7, 2010), Revisions to Energy Efficiency Enforcement Regulations, Request for Information (RFI);request for comm DOE 10 CFR Parts 430 and 431, Docket No.

  4. Pore-scale mechanisms of gas flow in tight sand reservoirs

    SciTech Connect (OSTI)

    Silin, D.; Kneafsey, T.J.; Ajo-Franklin, J.B.; Nico, P.

    2010-11-30

    Tight gas sands are unconventional hydrocarbon energy resource storing large volume of natural gas. Microscopy and 3D imaging of reservoir samples at different scales and resolutions provide insights into the coaredo not significantly smaller in size than conventional sandstones, the extremely dense grain packing makes the pore space tortuous, and the porosity is small. In some cases the inter-granular void space is presented by micron-scale slits, whose geometry requires imaging at submicron resolutions. Maximal Inscribed Spheres computations simulate different scenarios of capillary-equilibrium two-phase fluid displacement. For tight sands, the simulations predict an unusually low wetting fluid saturation threshold, at which the non-wetting phase becomes disconnected. Flow simulations in combination with Maximal Inscribed Spheres computations evaluate relative permeability curves. The computations show that at the threshold saturation, when the nonwetting fluid becomes disconnected, the flow of both fluids is practically blocked. The nonwetting phase is immobile due to the disconnectedness, while the permeability to the wetting phase remains essentially equal to zero due to the pore space geometry. This observation explains the Permeability Jail, which was defined earlier by others. The gas is trapped by capillarity, and the brine is immobile due to the dynamic effects. At the same time, in drainage, simulations predict that the mobility of at least one of the fluids is greater than zero at all saturations. A pore-scale model of gas condensate dropout predicts the rate to be proportional to the scalar product of the fluid velocity and pressure gradient. The narrowest constriction in the flow path is subject to the highest rate of condensation. The pore-scale model naturally upscales to the Panfilov's Darcy-scale model, which implies that the condensate dropout rate is proportional to the pressure gradient squared. Pressure gradient is the greatest near the matrix

  5. Model for the formation of longshore sand ridges on the Continental Shelf: The interaction of internal waves and the bottom topography

    SciTech Connect (OSTI)

    Restrepo, J.M. [Argonne National Lab., IL (United States); Bona, J.L. [Pennsylvania State Univ., University Park, PA (United States)

    1994-01-05

    Longshore sand ridges are frequently observed to occur on the continental shelf where the overlying ocean is stratified. This study formulates a model for the formation and evolution of three-dimensional longshore sand ridges on the continental shelf. The model is based on the interaction of interfacial, weakly nonlinear waves in a stratified ocean with the sedimentary bottom topography.

  6. Pulse studies to decipher the role of surface morphology in CuO/CeO₂ nanocatalysts for the water gas shift reaction

    SciTech Connect (OSTI)

    Rodriguez, Jose A.; Zhao, Fuzhen; Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; Si, Rui; Johnston-Peck, Aaron C.; Martinez-Arias, Arturo; Hanson, Jonathan C.; Senanayake, Sanjaya D.

    2015-01-23

    The water-gas shift reaction (WGS, CO + H₂O → CO₂) was studied over CuO/CeO₂ catalysts with two different ceria particle morphohologies, in the form of nanospheres (ns) and nanocubes (nc). To understand the strong dependence of the WGS reaction activity on the ceria nanoshapes, pulses of CO (without and with water vapor) were employed during in situ X-ray diffraction (XRD) and X-ray absoprtion near edge structure (XANES) measurements done to characterize the catalysts. The results showed that CuO/CeO₂ (ns) exhibited a substantially better activity than CuO/CeO₂ (nc). The higher activity was associated with the unique properties of CuO/CeO₂ (ns), such as the easier reduction of highly dispersed CuO to metallic Cu, the stability of metallic Cu and a larger concentration Ce³⁺ in CeO₂ (ns).

  7. Pulse studies to decipher the role of surface morphology in CuO/CeO₂ nanocatalysts for the water gas shift reaction

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

    Rodriguez, Jose A.; Zhao, Fuzhen; Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; Si, Rui; Johnston-Peck, Aaron C.; Martinez-Arias, Arturo; Hanson, Jonathan C.; Senanayake, Sanjaya D.

    2015-01-23

    The water-gas shift reaction (WGS, CO + H₂O → CO₂) was studied over CuO/CeO₂ catalysts with two different ceria particle morphohologies, in the form of nanospheres (ns) and nanocubes (nc). To understand the strong dependence of the WGS reaction activity on the ceria nanoshapes, pulses of CO (without and with water vapor) were employed during in situ X-ray diffraction (XRD) and X-ray absoprtion near edge structure (XANES) measurements done to characterize the catalysts. The results showed that CuO/CeO₂ (ns) exhibited a substantially better activity than CuO/CeO₂ (nc). The higher activity was associated with the unique properties of CuO/CeO₂ (ns), suchmore » as the easier reduction of highly dispersed CuO to metallic Cu, the stability of metallic Cu and a larger concentration Ce³⁺ in CeO₂ (ns).« less

  8. Varying properties of in situ heat treatment of a tar sands formation based on assessed viscosities

    DOE Patents [OSTI]

    Karanikas, John Michael; Vinegar, Harold J

    2014-03-04

    A method for treating a tar sands formation includes providing heat to at least part of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. The heat is allowed to transfer from the heaters to at least a portion of the formation. A viscosity of one or more zones of the hydrocarbon layer is assessed. The heating rates in the zones are varied based on the assessed viscosities. The heating rate in a first zone of the formation is greater than the heating rate in a second zone of the formation if the viscosity in the first zone is greater than the viscosity in the second zone. Fluids are produced from the formation through the production wells.

  9. Moving hydrocarbons through portions of tar sands formations with a fluid

    DOE Patents [OSTI]

    Stegemeier, George Leo; Mudunuri, Ramesh Raju; Vinegar, Harold J.; Karanikas, John Michael; Jaiswal, Namit; Mo, Weijian

    2010-05-18

    A method for treating a tar sands formation is disclosed. The method includes heating a first portion of a hydrocarbon layer in the formation from one or more heaters located in the first portion. The heat is controlled to increase a fluid injectivity of the first portion. A drive fluid and/or an oxidizing fluid is injected and/or created in the first portion to cause at least some hydrocarbons to move from a second portion of the hydrocarbon layer to a third portion of the hydrocarbon layer. The second portion is between the first portion and the third portion. The first, second, and third portions are horizontally displaced from each other. The third portion is heated from one or more heaters located in the third portion. Hydrocarbons are produced from the third portion of the formation. The hydrocarbons include at least some hydrocarbons from the second portion of the formation.

  10. Western Gas Sands Project. Status report, 1 March-31 March 1980

    SciTech Connect (OSTI)

    Not Available

    1980-01-01

    The March, 1980 progress of the government-sponsored projects directed towards increasing gas production from the low permeability gas sands of the western United States is summarized in this report. A site for the multi-well experiment was approved by the industry review committee; drilling is expected by mid-summer. Bartlesville Energy Technology Center continued work on fracture conductivity, rock/fluid interaction, and log evaluation and interpretation techniques. Lawrence Livermore Laboratory continued experimental and theoretical work on hydraulic fracturing mechanics and analysis of well test data. Analysis of data obtained from a test of the borehole seismic unit by Sandia Laboratories continued. The DOE Well Test Facility continued bottom-hole pressure buildup measurements at the Colorado Interstate Gas Company Miller No. 1 well.

  11. Western Gas Sands Project. Status report, 1 May-31 May, 1980

    SciTech Connect (OSTI)

    Not Available

    1980-01-01

    This report summarizes the progress of the government-sponsored project directed towards increasing gas production from the low permeability gas sands of the western United States. The planning activities for the multi-well experiment continued in May. Bartlesville Energy Technology Center continued formation evaluation and reservoir simulation studies. Lawrence Livermore Laboratory continued calculations of fracturing near interfaces. Los Alamos Scientific Laboratory focused work on the permanent magnet system for NMR logging. Results of the 3-D Seismic Reflection Survey were presented by Sandia Laboratories. Production and injection experiments continued for the Colorado Interstate Gas Company Miller No. 1 and Sprague No. 1 wells. The DOE Well Test Facility was transported to Las Vegas for repairs and modifications. In situ testing continued at the Nevada Test Site for the Sandia Mineback program.

  12. Weak hybridization and isolated localized magnetic moments in the compounds CeT2Cd20 (T = Ni, Pd)

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

    White, B. D.; Yazici, D.; Ho, P. -C.; Kanchanavatee, N.; Pouse, N.; Fang, Y.; Breindel, A. J.; Friedman, A. J.; Maple, M. B.

    2015-07-20

    Here, we report the physical properties of single crystals of the compounds CeT2Cd20 (T = Ni, Pd) that were grown in a molten Cd flux. Large separations of ~6.7- 6.8 Å between Ce ions favor the localized magnetic moments that are observed in measurements of the magnetization. The strength of the Ruderman-Kittel-Kasuya- Yosida magnetic exchange interaction between the localized moments is severely limited by the large Ce-Ce separations and by weak hybridization between localized Ce 4f and itinerant electron states. Measurements of electrical resistivity performed down to 0.138 K were unable to observe evidence for the emergence of magnetic order;more » however, magnetically-ordered ground states with very low transition temperatures are still expected in these compounds despite the isolated nature of the localized magnetic moments. Such a fragile magnetic order could be highly susceptible to tuning via applied pressure, but evidence for the emergence of magnetic order has not been observed so far in our measurements up to 2.5 GPa.« less

  13. Nickel deficiency in RENi2-xP2 (RE=La, Ce, Pr). Combined crystallographic and physical property studies

    SciTech Connect (OSTI)

    Bauer, Eric D; Ronning, Filip; Thompson, Joe D; Sarrao, John L; Bobev, S; Xia, S

    2008-01-01

    Large single crystals from RENi{sub 2-x}P{sub 2} (RE = La, Ce, Pr) were synthesized from the pure elements using Sn as a metal flux, and their structures were established by X-ray crystallography. The title compounds were confirmed to crystallize in the body-centered tetragonal ThCr{sub 2}Si{sub 2} structure type (space group I4/mmm (No. 139); Pearson's symbol tI10), but with a significant stoichiometry breadth with respect to the transition metal. Systematic synthetic work, coupled with accurate structure refinements indicated strong correlation between the degree of Ni-deficiency and the reaction conditions. For four different PrNi{sub 2-x}P{sub 2} (x {le} 0.5) samples, temperature dependent dc magnetization measurements indicated typical local moment 4f-magnetism and a stable Pr{sup 3+} ground state. Field-dependent heat capacity data confirmed a ferromagnetic order at low temperature, and the variations of T{sub c} with the concentration of Ni defects are discussed. LaNi{sub 2-x}P{sub 2}, as expected was found to be Pauli-like paramagnetic in the studied temperature regime, while the Ce-analog CeNi{sub 2-x}P{sub 2} (x = 0.28(1)) showed the characteristics of a mixed valent Ce{sup 3+}/Ce{sup 4+} system with a possible Kondo temperature on the order of 230 K.

  14. High thermal stability of La2O3 and CeO2-stabilized tetragonal ZrO2

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

    Wang, Shichao; Xie, Hong; Lin, Yuyuan; Poeppelmeier, Kenneth R.; Li, Tao; Winans, Randall E.; Cui, Yanran; Ribeiro, Fabio H.; Canlas, Christian P.; Elam, Jeffrey W.; et al

    2016-02-15

    Catalyst support materials of tetragonal ZrO2, stabilized by either La2O3 (La2O3-ZrO2) or CeO2 (CeO2-ZrO2), were synthesized under hydrothermal conditions at 200 °C with NH4OH or tetramethylammonium hydroxide as the mineralizer. From In Situ synchrotron powder X-ray diffraction and small-angle X-ray scattering measurements, the calcined La2O3-ZrO2 and CeO2-ZrO2 supports were nonporous nanocrystallites that exhibited rectangular shapes with thermal stability up to 1000 °C in air. These supports had an average size of ~10 nm and a surface area of 59-97 m2/g. The catalysts Pt/La2O3-ZrO2 and Pt/CeO2-ZrO2 were prepared by using atomic layer deposition with varying Pt loadings from 6.3-12.4 wt %.more » Mono-dispersed Pt nanoparticles of ~3 nm were obtained for these catalysts. As a result, the incorporation of La2O3 and CeO2 into the t-ZrO2 structure did not affect the nature of the active sites for the Pt/ZrO2 catalysts for the water-gas-shift (WGS) reaction.« less

  15. Policy Analysis of Water Availability and Use Issues for Domestic Oil Shale and Oil Sands Development

    SciTech Connect (OSTI)

    Ruple, John; Keiter, Robert

    2010-12-31

    Oil shale and oil sands resources located within the intermountain west represent a vast, and as of yet, commercially untapped source of energy. Development will require water, and demand for scarce water resources stands at the front of a long list of barriers to commercialization. Water requirements and the consequences of commercial development will depend on the number, size, and location of facilities, as well as the technologies employed to develop these unconventional fuels. While the details remain unclear, the implication is not – unconventional fuel development will increase demand for water in an arid region where demand for water often exceeds supply. Water demands in excess of supplies have long been the norm in the west, and for more than a century water has been apportioned on a first-come, first-served basis. Unconventional fuel developers who have not already secured water rights stand at the back of a long line and will need to obtain water from willing water purveyors. However, uncertainty regarding the nature and extent of some senior water claims combine with indeterminate interstate river management to cast a cloud over water resource allocation and management. Quantitative and qualitative water requirements associated with Endangered Species protection also stand as barriers to significant water development, and complex water quality regulations will apply to unconventional fuel development. Legal and political decisions can give shape to an indeterminate landscape. Settlement of Northern Ute reserved rights claims would help clarify the worth of existing water rights and viability of alternative sources of supply. Interstate apportionment of the White River would go a long way towards resolving water availability in downstream Utah. And energy policy clarification will help determine the role oil shale and oil sands will play in our nation’s future.

  16. Headspace solid-phase microextraction (HS-SPME) for the determination of benzene, toluene, ethylbenzene, and xylenes (BTEX) in foundry molding sand

    SciTech Connect (OSTI)

    Dungan, R.S. [USDA ARS, Beltsville, MD (United States). Environmental Management & Byproducts Utilization Laboratory

    2005-07-01

    The use of headspace solid-phase microextraction (HS-SPME) to determine benzene, toluene, ethylbenzene, and xylenes (BTEX) in foundry molding sand, specifically a 'green sand' (clay-bonded sand) was investigated. The BTEX extraction was conducted using a 75 {mu} M carboxen-polydimethylsiloxane (CAR-PDMS) fiber, which was suspended above 10 g of sample. The SPME fiber was desorbed in a gas chromatograph injector port (280{sup o}C for 1 min) and the analytes were characterized by mass spectrometry. The effects of extraction time and temperature, water content, and clay and bituminous coal percentage on HS-SPME of BTEX were investigated. Because green sands contain bentonite clay and carbonaceous material such as crushed bituminous coal, a matrix effect was observed. The detection limits for BTEX were determined to be {lt}= 0.18 ng g{sup -1} of green sand.

  17. Theoretical Study of Trimethylacetic Acid Adsorption on CeO 2 (111) Surface

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

    Wang, Weina; Thevuthasan, S.; Wang, Wenliang; Yang, Ping

    2016-01-11

    We investigated trimethylacetic acid (TMAA) adsorption on stoichiometric and oxygen-deficient CeO2(111) surfaces using density functional theory that accounts for the on-site Coulomb interaction via a Hubbard term (DFT+U) and long-range dispersion correction. Both the molecular state and dissociative state (TMAA → TMA– + H+) were identified on stoichiometric and oxygen-deficient CeO2(111) surfaces. For the stoichiometric surface, two thermodynamically favorable configurations with adsorption energies of the order of -30 kcal/mol are identified; one is a molecule adsorption state, and the other one is a dissociative state. For the oxygen-deficient surface, dissociative states are more favorable than molecular states. Moreover, the mostmore » favorable configuration is the dissociative adsorption of TMAA with the adsorption energy of the order of -77 kcal/mol. The dissociated TMA moiety takes the position of oxygen vacancy, forming three Ce–O bonds. The signature vibrational frequencies for these thermodynamically stable structures are reported as well as their electronic structures. The effects of long-range dispersion interactions are found to be negligible for geometries but important for adsorption energies.« less

  18. IDENTIFICATION OF APPROPRIATE QUALIFICATION TESTING AND END-OF-LIFE WASTE STORAGE CONSIDERATIONS FOR DEEP BED SAND FILTERS

    SciTech Connect (OSTI)

    Matthews, K.

    2010-06-02

    Deep bed sand (DBS) filters have filtered radioactive particulates at two United States Department of Energy (DOE) sites since 1948. Some early DBS filters experienced issues with chemical attack on support tiles, requiring significant repairs. Designs of DBS filters constructed since 1970 paid greater attention to chemical compatibility, resulting in decades of reliable performance since 1975.

  19. Hydrogenation of CO2 to methanol on CeOx/Cu(111) and ZnO/Cu(111) catalysts: Role of the metal-oxide interface and importance of Ce3+ sites

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

    Sanjaya D. Senanayake; Ramirez, Pedro J.; Waluyo, Iradwikanari; Kundu, Shankhamala; Mudiyanselage, Kumudu; Liu, Zongyuan; Liu, Zhi; Axnanda, Stephanus; Stacchiola, Dario J.; Evans, Jaime; et al

    2016-01-06

    The role of the interface between a metal and oxide (CeOx–Cu and ZnO–Cu) is critical to the production of methanol through the hydrogenation of CO2 (CO2 + 3H2 → CH3OH + H2O). The deposition of nanoparticles of CeOx or ZnO on Cu(111), θoxi < 0.3 monolayer, produces highly active catalysts for methanol synthesis. The catalytic activity of these systems increases in the sequence: Cu(111) < ZnO/Cu(111) < CeOx/Cu(111). The apparent activation energy for the CO2 → CH3OH conversion decreases from 25 kcal/mol on Cu(111) to 16 kcal/mol on ZnO/Cu(111) and 13 kcal/mol on CeOx/Cu(111). The surface chemistry of the highlymore » active CeOx–Cu(111) interface was investigated using ambient pressure X-ray photoemission spectroscopy (AP-XPS) and infrared reflection absorption spectroscopy (AP-IRRAS). Both techniques point to the formation of formates (HCOO–) and carboxylates (CO2δ–) during the reaction. Our results show an active state of the catalyst rich in Ce3+ sites which stabilize a CO2δ– species that is an essential intermediate for the production of methanol. Furthermore, the inverse oxide/metal configuration favors strong metal–oxide interactions and makes possible reaction channels not seen in conventional metal/oxide catalysts.« less

  20. Electronic structure of the heavy-fermion caged compound Ce?Pd??X? (X = Si, Ge) studied by density functional theory and photoelectron spectroscopy

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

    Yamaoka, Hitoshi; Jarrige, Ignace; Schwier, Eike F.; Arita, Masashi; Shimada, Kenya; Tsujii, Naohito; Jiang, Jian; Hayashi, Hirokazu; Iwasawa, Hideaki; Namatame, Hirofumi; et al

    2015-03-30

    The electronic structure of Ce?Pd??X? (X = Si, Ge) has been studied using detailed density functional theory (DFT) calculations and high-resolution photoelectron spectroscopy (PES) measurements. The orbital decomposition of the electronic structure by DFT calculations indicates that Ce atoms at the (8c) site surrounded by 16 Pd atoms have a more localized nature and a tendency to be magnetic. Ce atoms in the (4a) site surrounded by 12 Pd and 6 X atoms, on the other, show only a negligible magnetic moment. In the photoemission valence-band spectra we observe a strong f? (Ce??) component with a small fraction of fmore(Ce?) component. The spectral weight of f component near the Fermi level Ce?Pd??Si? is stronger than that for Ce?Pd??Ge? at the 4d-4f resonance, suggesting stronger c-f hybridization in the former. This may hint to the origin of the large electronic specific coefficient of Ce?Pd??Si? compared to Ce?Pd??Ge?.less

  1. Influence of solvent on the morphology and photocatalytic properties of ZnS decorated CeO{sub 2} nanoparticles

    SciTech Connect (OSTI)

    Raubach, Cristiane W. Polastro, Lisnias; Ferrer, Mateus M.; Perrin, Andre; Perrin, Christiane; Albuquerque, Anderson R.; Buzolin, Prescila G. C.; Sambrano, Julio R.; Santana, Yuri B. V. de; Varela, Jos A.; Longo, Elson

    2014-06-07

    Herein, we report a theoretical and experimental study on the photocatalytic activity of CeO{sub 2} ZnS, and ZnS decorated CeO{sub 2} nanoparticles prepared by a microwave-assisted solvothermal method. Theoretical models were established to analyze electron transitions primarily at the interface between CeO{sub 2} and ZnS. As observed, the particle morphology strongly influenced the photocatalytic degradation of organic dye Rhodamine B. A model was proposed to rationalize the photocatalytic behavior of the prepared decorated systems taking into account different extrinsic and intrinsic defect distributions, including order-disorder effects at interfacial and intra-facial regions, and vacancy concentration.

  2. Update on the CeC PoP 704 MHz 5-cell cavity cryomodule design and fabrication

    SciTech Connect (OSTI)

    Brutus, J. C.; Belomestnykh, S.; Ben-Zvi, I.; Grimm, T.; Huang, Y.; Jecks, R.; Kelly, M.; Litvinenko, V.; Pinayev, I.; Reid, T.; Skaritka, J.; Snydstrup, L.; Than, R.; Tuozzolo, J.; Xu, W.; Yancey, J.; Gerbick, S.

    2015-05-03

    A 5-cell SRF cavity operating at 704 MHz will be used for the Coherent Electron Cooling Proof of Principle (CeC PoP) system under development for the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The CeC PoP experiment will demonstrate the new technique of cooling proton and ion beams that may increase the beam luminosity in certain cases, by as much as tenfold. The 704 MHz cavity will accelerate 2 MeV electrons from a 112 MHz SRF gun up to 22MeV. This paper provides an overview of the design, the project status and schedule of the 704 MHz 5-cell SRF for CeC PoP experiment.

  3. Temperature Dependence of the Kondo Resonance and Its Satellites in CeCu{sub 2}Si{sub 2}

    SciTech Connect (OSTI)

    Reinert, F.; Ehm, D.; Schmidt, S.; Nicolay, G.; Huefner, S.; Kroha, J.; Trovarelli, O.; Geibel, C.

    2001-09-03

    We present high-resolution photoemission spectroscopy studies on the Kondo resonance of the strongly correlated Ce system CeCu{sub 2}Si {sub 2} . By exploiting the thermal broadening of the Fermi edge we analyze position, spectral weight, and temperature dependence of the low-energy 4f spectral features, whose major weight lies above the Fermi level E{sub F} . We also present theoretical predictions based on the single-impurity Anderson model using an extended noncrossing approximation, including all spin-orbit and crystal field splittings of the 4f states. The excellent agreement between theory and experiment provides strong evidence that the spectral properties of CeCu{sub 2}Si {sub 2} can be described by single-impurity Kondo physics down to T{approx}5 K .

  4. Selectivity loss of Pt/CeO{sub 2} PROX catalysts at low CO concentrations: mechanism and active site study.

    SciTech Connect (OSTI)

    Polster, C. S.; Zhang, R.; Cyb, M. T.; Miller, J. T.; Baertsch, C. D.

    2010-07-01

    CO and H{sub 2} oxidation were studied over a series of Pt/CeO{sub 2} catalysts with differing Pt loadings and dispersions. Kinetic rate analysis confirms the presence of dual Langmuir-Hinshelwood (L-H) and Mars and van Krevelen (M-vK) pathways and is used to explain the loss in CO oxidation selectivity at low CO concentrations. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) shows the strong CO coverage dependence on both CO and O{sub 2} concentrations and explains the transition from L-H to M-vK reaction character. Redox site measurements are performed on Pt/CeO{sub 2} catalysts by anaerobic titrations under conditions where the M-vK pathway dominates the reaction rate. Similar redox site densities per interfacial Pt atom suggest that interfacial Pt-O-Ce sites are responsible for M-vK redox activity.

  5. 6450-01-P, DOE 10 CFR Parts 430 and 431, Docket No. EERE-2010-BT-CE-0014

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

    RIN 1904-AC23, Draft Submission to Federal Register, Notice of Revisions to Energy Efficiency Enforcement Regulations, Request for Information/comment. | Department of Energy 6450-01-P, DOE 10 CFR Parts 430 and 431, Docket No. EERE-2010-BT-CE-0014 RIN 1904-AC23, Draft Submission to Federal Register, Notice of Revisions to Energy Efficiency Enforcement Regulations, Request for Information/comment. 6450-01-P, DOE 10 CFR Parts 430 and 431, Docket No. EERE-2010-BT-CE-0014 RIN 1904-AC23, Draft

  6. Unusual Kondo-hole effect and crystal-field frustration in Nd-doped CeRhIn

    Office of Scientific and Technical Information (OSTI)

    5 (Journal Article) | SciTech Connect Unusual Kondo-hole effect and crystal-field frustration in Nd-doped CeRhIn 5 Citation Details In-Document Search This content will become publicly available on July 5, 2017 Title: Unusual Kondo-hole effect and crystal-field frustration in Nd-doped CeRhIn 5 Authors: Rosa, P. F. S. ; Oostra, A. ; Thompson, J. D. ; Pagliuso, P. G. ; Fisk, Z. Publication Date: 2016-07-05 OSTI Identifier: 1260297 Type: Publisher's Accepted Manuscript Journal Name: Physical

  7. QUANTITATIVE METHODS FOR RESERVOIR CHARACTERIZATION AND IMPROVED RECOVERY: APPLICATION TO HEAVY OIL SANDS

    SciTech Connect (OSTI)

    James W. Castle; Fred J. Molz; Ronald W. Falta; Cynthia L. Dinwiddie; Scott E. Brame; Robert A. Bridges

    2002-10-30

    Improved prediction of interwell reservoir heterogeneity has the potential to increase productivity and to reduce recovery cost for California's heavy oil sands, which contain approximately 2.3 billion barrels of remaining reserves in the Temblor Formation and in other formations of the San Joaquin Valley. This investigation involves application of advanced analytical property-distribution methods conditioned to continuous outcrop control for improved reservoir characterization and simulation, particularly in heavy oil sands. The investigation was performed in collaboration with Chevron Production Company U.S.A. as an industrial partner, and incorporates data from the Temblor Formation in Chevron's West Coalinga Field. Observations of lateral variability and vertical sequences observed in Temblor Formation outcrops has led to a better understanding of reservoir geology in West Coalinga Field. Based on the characteristics of stratigraphic bounding surfaces in the outcrops, these surfaces were identified in the subsurface using cores and logs. The bounding surfaces were mapped and then used as reference horizons in the reservoir modeling. Facies groups and facies tracts were recognized from outcrops and cores of the Temblor Formation and were applied to defining the stratigraphic framework and facies architecture for building 3D geological models. The following facies tracts were recognized: incised valley, estuarine, tide- to wave-dominated shoreline, diatomite, and subtidal. A new minipermeameter probe, which has important advantages over previous methods of measuring outcrop permeability, was developed during this project. The device, which measures permeability at the distal end of a small drillhole, avoids surface weathering effects and provides a superior seal compared with previous methods for measuring outcrop permeability. The new probe was used successfully for obtaining a high-quality permeability data set from an outcrop in southern Utah. Results obtained

  8. Magnetic structure of the antiferromagnetic Kondo lattice compounds CeRhAl4Si2 and CeIrAl4Si2

    SciTech Connect (OSTI)

    Ghimire, N. J.; Calder, S.; Janoschek, M.; Bauer, E. D.

    2015-06-01

    In this article, we have investigated the magnetic ground state of the antiferromagnetic Kondo-lattice compounds CeMAl4Si2(M = Rh, Ir) using neutron powder diffraction. Although both of these compounds show two magnetic transitions TN1 and TN2 in the bulk properties measurements, evidence for magnetic long-range order was only found below the lower transition TN2. Analysis of the diffraction profiles reveals a commensurate antiferromagnetic structure with a propagation vector k = (0, 0, 1/2). The magnetic moment in the ordered state of CeRhAl4Si2 and CeIrAl4Si2 were determined to be 1.14(2) and 1.41(3) ?B/Ce, respectively, and are parallel to the crystallographic c-axis in agreement with magnetic susceptibility measurements.

  9. Magnetic structure of the antiferromagnetic Kondo lattice compounds CeRhAl4Si2 and CeIrAl4Si2

    SciTech Connect (OSTI)

    Ghimire, N. J.; Calder, S.; Janoschek, M.; Bauer, E. D.

    2015-06-01

    In this article, we have investigated the magnetic ground state of the antiferromagnetic Kondo-lattice compounds CeMAl4Si2(M = Rh, Ir) using neutron powder diffraction. Although both of these compounds show two magnetic transitions TN1 and TN2 in the bulk properties measurements, evidence for magnetic long-range order was only found below the lower transition TN2. Analysis of the diffraction profiles reveals a commensurate antiferromagnetic structure with a propagation vector k = (0, 0, 1/2). The magnetic moment in the ordered state of CeRhAl4Si2 and CeIrAl4Si2 were determined to be 1.14(2) and 1.41(3) μB/Ce, respectively, and are parallel to the crystallographic c-axis in agreement with magnetic susceptibility measurements.

  10. Vortex Lattice Studies in CeCoIn₅ with H⊥c

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

    Das, P.; White, J. S.; Holmes, A. T.; Gerber, S.; Forgan, E. M.; Bianchi, A. D.; Kenzelmann, M.; Zolliker, M.; Gavilano, J. L.; Bauer, E. D.; et al

    2012-02-23

    We present small angle neutron scattering studies of the vortex lattice (VL) in CeCoIn₅ with magnetic fields applied parallel (H) to the antinodal [100] and nodal [110] directions. For H II 100], a single VL orientation is observed, while a 90° reorientation transition is found for H II [110]. For both field orientations and VL configurations we find a distorted hexagonal VL with an anisotropy, Γ=2.0±0.05. The VL form factor shows strong Pauli paramagnetic effects similar to what have previously been reported for H II [001]. At high fields, above which the upper critical field (Hc2) becomes a first-order transition,more » an increased disordering of the VL is observed.« less

  11. Nanostructured Lanthanum Halides and CeBr3 for Nuclear Radiation and Detection

    SciTech Connect (OSTI)

    Paul Guss, Sanjoy Mukhopadhyay, Ron Guise, Ding Yuan

    2010-06-09

    Scintillator materials are used to detect, and in some cases identify, gamma rays. Higher performance scintillators are expensive, hard to manufacture, fragile, and sometimes require liquid nitrogen or cooling engines. But whereas lower-quality scintillators are cheap, easy to manufacture, and more rugged, their performance is lower. At issue: can the desirable qualities of high-and low-performance scintillators be combined to achieve better performance at lower cost? Preliminary experiments show that a LaF{sub 3}:Ce oleic acid-based nanocomposite exhibits a photopeak when exposed to {sup 137}Cs source gamma-radiation. The chemical synthesis of the cerium-doped lanthanum halide nanoparticles are scalable and large quantities of material can be produced at a time, unlike typical crystal growth processes such as the Bridgeman process. Using a polymer composite (Figure 1), produced by LANL, initial measurements of the unloaded and 8% LaF{sub 3}:Ce-loaded sample have been made using {sup 137}Cs sources. Figure 2 shows an energy spectrum acquired for CeF{sub 3}. The lighter plot is the measured polymer-only spectrum and the black plot is the spectrum from the nanocomposite scintillator. As the development of this material continues, the energy resolution is expected to improve and the photopeak-to-Compton ratio will become greater at higher loadings. These measurements show the expected Compton edge in the polymer-only sample, and the Compton edge and photo-peak expected in the nanophosphor composites that LANL has produced. Using a porous VYCORR with CdSe/ZnS core shell quantum dots, Letant has demonstrated that he has obtained signatures of the 241Am photopeak with energy resolution as good at NaI (Figure 3). We begin with the fact that CeBr{sub 3} crystals do not have a self-activity component as strong as the lanthanum halides. The radioactive 0.090% {sup 138}La component of lanthanum leads to significant self-activity, which will be a problem for very large

  12. Differential conductance and defect states in the heavy-fermion superconductor CeCoIn5

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

    John S. Van Dyke; Davis, James C.; Morr, Dirk K.

    2016-01-22

    We demonstrate that the electronic band structure extracted from quasiparticle interference spectroscopy [Nat. Phys. 9, 468 (2013)] and the theoretically computed form of the superconducting gaps [Proc. Natl. Acad. Sci. USA 111, 11663 (2014)] can be used to understand the dI/dV line shape measured in the normal and superconducting state of CeCoIn5 [Nat. Phys. 9, 474 (2013)]. In particular, the dI/dV line shape, and the spatial structure of defect-induced impurity states, reflects the existence of multiple superconducting gaps of dx2–y2 symmetry. As a result, these results strongly support a recently proposed microscopic origin of the unconventional superconducting state.

  13. Theoretical studies of Ir5Th and Ir5Ce nanoscale precipitates in Ir

    SciTech Connect (OSTI)

    Morris, James R; Averill, Frank; Cooper, Valentino R

    2014-01-01

    Experimentally, it is known that very small amounts of thorium and/or cerium added to iridium metal form a precipitate, Ir5Th / Ir5Ce, which improves the high temperature mechanical properties of the resulting alloys. We demonstrate that there are low-energy configurations for nano-scale precipitates of these phases in Ir, and that these coherent arrangements may assist in producing improved mechanical properties. One precipitate/matrix orientation gives a particularly low interfacial energy, and a low lattice misfit. Nanolayer precipitates with this orientation are found to be likely to form, with little driving force to coarsen. The predicted morphology of the precipitates and their orientation with the matrix phase provide a potential experiment that could be used to test these predictions.

  14. Improved thermoelectric performance of n-type Ca and Ca-Ce filled skutterudites

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

    Thompson, Daniel R.; Liu, Chang; Ellison, Nicole D.; Salvador, James R.; Meyer, Martin S.; Haddad, Daad B.; Wang, Hsin; Cai, W.

    2014-12-28

    Thermoelectric (TE) technology for use in automotive waste heat recovery is being advanced by General Motors with support from the US Department of Energy. Skutterudites are a very promising material for this application of TE technology due to their superior mechanical properties and good TE performance. Double-filled YbxBayCo4Sb12 with ZT values around 1.1 at 750K are the best performing n-type skutterudites produced on a large scale using an economically viable approach of melt spinning (MS) in conjunction with spark plasma sintering (SPS). Another economical production method on the tons scale, the melt quench annealing (MQA) technique, has been recently claimedmore » by Treibacher Industrie AG, further information is available [G. Rogl et al., Acta Mater. 76, 434-448 (2014)]. A possible hurdle to commercial implementation of these materials is the use of rare earths as the fillers to reduce thermal conductivity and improve the electrical transport properties. It will be shown herein that skutterudites double-filled with Ca and Ce, both of which are lower-cost fillers, display markedly different TE properties depending on whether they are produced by MQA or MS + SPS synthesis techniques. Finally, Ca and Ce double-filled skutterudites prepared by MS + SPS have TE properties that are superior to the same compositions prepared by MQA and that are comparable to the best performing Yb and Ba filled materials. Furthermore, the results of this study suggest that the unusually poor transport properties of MQA Ca-filled skutterudites can be ascribed to deleterious secondary phases, which is contrary to reports in the literature attempting to explain these irregularities via band structure features.« less

  15. Improved thermoelectric performance of n-type Ca and Ca-Ce filled skutterudites

    SciTech Connect (OSTI)

    Thompson, Daniel R.; Liu, Chang; Ellison, Nicole D.; Salvador, James R.; Meyer, Martin S.; Haddad, Daad B.; Wang, Hsin; Cai, W.

    2014-12-28

    Thermoelectric (TE) technology for use in automotive waste heat recovery is being advanced by General Motors with support from the US Department of Energy. Skutterudites are a very promising material for this application of TE technology due to their superior mechanical properties and good TE performance. Double-filled YbxBayCo4Sb12 with ZT values around 1.1 at 750K are the best performing n-type skutterudites produced on a large scale using an economically viable approach of melt spinning (MS) in conjunction with spark plasma sintering (SPS). Another economical production method on the tons scale, the melt quench annealing (MQA) technique, has been recently claimed by Treibacher Industrie AG, further information is available [G. Rogl et al., Acta Mater. 76, 434-448 (2014)]. A possible hurdle to commercial implementation of these materials is the use of rare earths as the fillers to reduce thermal conductivity and improve the electrical transport properties. It will be shown herein that skutterudites double-filled with Ca and Ce, both of which are lower-cost fillers, display markedly different TE properties depending on whether they are produced by MQA or MS + SPS synthesis techniques. Finally, Ca and Ce double-filled skutterudites prepared by MS + SPS have TE properties that are superior to the same compositions prepared by MQA and that are comparable to the best performing Yb and Ba filled materials. Furthermore, the results of this study suggest that the unusually poor transport properties of MQA Ca-filled skutterudites can be ascribed to deleterious secondary phases, which is contrary to reports in the literature attempting to explain these irregularities via band structure features.

  16. Improved thermoelectric performance of n-type Ca and Ca-Ce filled skutterudites

    SciTech Connect (OSTI)

    Thompson, Daniel R.; Liu, Chang; Ellison, Nicole D.; Salvador, James R.; Meyer, Martin S.; Haddad, Daad B.; Wang, Hsin; Cai, W.

    2014-12-28

    Thermoelectric (TE) technology for use in automotive waste heat recovery is being advanced by General Motors with support from the US Department of Energy. Skutterudites are a very promising material for this application of TE technology due to their superior mechanical properties and good TE performance. Double-filled Yb{sub x}Ba{sub y}Co{sub 4}Sb{sub 12} with ZT values around 1.1 at 750?K are the best performing n-type skutterudites produced on a large scale using an economically viable approach of melt spinning (MS) in conjunction with spark plasma sintering (SPS). Another economical production method on the tons scale, the melt quench annealing (MQA) technique, has been recently claimed by Treibacher Industrie AG, further information is available [G. Rogl et al., Acta Mater. 76, 434448 (2014)]. A possible hurdle to commercial implementation of these materials is the use of rare earths as the fillers to reduce thermal conductivity and improve the electrical transport properties. It will be shown herein that skutterudites double-filled with Ca and Ce, both of which are lower-cost fillers, display markedly different TE properties depending on whether they are produced by MQA or MS + SPS synthesis techniques. Ca and Ce double-filled skutterudites prepared by MS + SPS have TE properties that are superior to the same compositions prepared by MQA and that are comparable to the best performing Yb and Ba filled materials. Furthermore, the results of this study suggest that the unusually poor transport properties of MQA Ca-filled skutterudites can be ascribed to deleterious secondary phases, which is contrary to reports in the literature attempting to explain these irregularities via band structure features.

  17. Transport properties of Ce{sub 2}Ni{sub 2}Sn and Ce{sub 2}Pd{sub 2.05}Sn{sub 0.95} Kondo lattice systems

    SciTech Connect (OSTI)

    Pinto, R.P.; Amado, M.M.; Braga, M.E.; de Azevedo, M.M.; Sousa, J.B.; Chevalier, B.; Etourneau, J.

    1997-04-01

    We report experimental data on thermoelectric power S, electrical resistivity {rho}, and the magnetoresistivity of the antiferromagnet Kondo stannides Ce{sub 2}Ni{sub 2}Sn (T{sub N}=4.7 K) and Ce{sub 2}Pd{sub 2.05}Sn{sub 0.95} (T{sub N}=4.7 K). The essential features of the S(T) curves resemble those of heavy fermion systems such as CeCu{sub 2}Si{sub 2}: a broad and positive maximum at intermediate temperatures, followed by a sharper negative minimum at lower temperatures. S values are is considerably smaller in Ce{sub 2}Pd{sub 2.05}Sn{sub 0.95} than in Ce{sub 2}Ni{sub 2}Sn. The positive peak originates from the incoherent Kondo scattering by the excited crystal field levels of the Ce ion ground state. The negative peak might be related to the shape of the density of states associated with the Abrikosov{endash}Suhl resonance. The change of sign in S(T) between its minimum and maximum at T{sup {asterisk}} can be assigned to the fact that the Fermi level sinks below the upper band at T{gt}T{sup {asterisk}}. This behavior and the maximum observed in the {rho}(T) curve at this temperature can be discussed in terms of the electron polaron model, although one must also take into account the crystal field effect. The role played by the crystal field effect, which is more important in Ce{sub 2}Pd{sub 2.05}Sn{sub 0.95}, is analyzed for this compound, providing the magnitude of the crystal field splitting. Magnetoresistivity was also measured in both compounds. The results are consistent with the important role of the Kondo effect at low temperatures and suggest the splitting of the double degenerate bands at T{gt}T{sup {asterisk}}. {copyright} {ital 1997 American Institute of Physics.}

  18. The effect of Au and Ni doping on the heavy fermion state of the Kondo lattice antiferromagnet CePtZn

    SciTech Connect (OSTI)

    Dhar, S. K.; Aoki, Y.; Suemitsu, B.; Miyazaki, R.; Provino, A.; Manfrinetti, P.

    2014-05-07

    We have probed the effect of doping CePtZn with Au and Ni and also investigated in detail the magnetic behavior of the iso-structural CeAuZn. A magnetic ground state is observed in both CePt{sub 0.9}Au{sub 0.1}Zn and CePt{sub 0.9}Ni{sub 0.1}Zn with T{sub N}?=?2.1 and 1.1?K and the coefficient of the linear term of electronic heat capacity ??=?0.34 and 0.9?J/mol K{sup 2}, respectively. The corresponding values for CePtZn are 1.7?K and 0.6?J/mol K{sup 2}. The altered values of T{sub N} and ? show that the electronic correlations in CePtZn are affected by doping with Au and Ni. CeAuZn orders magnetically near 1.7?K and its electrical resistivity shows a normal metallic behavior. Together with a ? of 0.022?J/mol K{sup 2} the data indicate a weak 4f-conduction electron hybridization in CeAuZn characteristic of normal trivalent cerium based systems.

  19. Investigation of the physical properties of the tetragonal CeMAl4Si2 (M = Rh, Ir, Pt) compounds

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

    Ghimire, N. J.; Ronning, F.; Williams, D. J.; Scott, B. L.; Luo, Yongkang; Thompson, J. D.; Bauer, E. D.

    2014-12-15

    The synthesis, crystal structure and physical properties studied by means of x-ray diffraction, magnetic, thermal and transport measurements of CeMAl4Si2 (M = Rh, Ir, Pt) are reported, along with the electronic structure calculations for LaMAl4Si2 (M = Rh, Ir, Pt). These materials adopt a tetragonal crystal structure (space group P4/mmm) comprised of BaAl4 blocks, separated by MAl2 units, stacked along the c-axis. Both CeRhAl4Si2 and CeIrAl4Si2 order antiferromagnetically below TN1 = 14 and 16 K, respectively, and undergo a second antiferromagnetic transitition at lower temperature (TN2 = 9 and 14 K, respectively). CePtAl4Si2 orders ferromagnetically below TC = 3 Kmore » with an ordered moment of μsat = 0.8 μB for a magnetic field applied perpendicular to the c-axis. Electronic structure calculations reveal quasi-2D character of the Fermi surface.« less

  20. The effect of Ce{sup 4+} incorporation on structural, morphological and photocatalytic characters of ZnO nanoparticles

    SciTech Connect (OSTI)

    Kannadasan, N.; Shanmugam, N. Cholan, S.; Sathishkumar, K.; Viruthagiri, G.; Poonguzhali, R.

    2014-11-15

    We report a simple chemical precipitation method for the preparation of undoped and cerium doped ZnO nanocrystals. The concentration of cerium in the products can be controlled in the range of 0.0250.125 mol. The structure and chemical compositions of the products were characterized by X-ray diffraction, X-ray photoelectron spectroscopy; energy dispersive spectrum and Fourier transform infrared spectroscopy. The results demonstrate that Ce{sup 4+} ions were successfully incorporated into the lattice position of Zn{sup 2+} ions in ZnO. The morphology of the products was analyzed by field emission scanning electron microscopy and confirmed by high resolution transmission electron microscope analysis. The optical properties of the products were studied by ultravioletvisible and room temperature photoluminescence measurements. The photoluminescence emission spectra of Ce-doped ZnO showed enhanced visible emissions as a result of 5d ? 4f transition of cerium. In particular, a novel photocatalytic activity of the products was assessed using methylene blue. The obtained result reveals that Ce-doped products show higher reduction efficiency for methylene blue than the undoped ZnO. - Highlights: Nanocrystals of ZnO and ZnO:Ce{sup 4+} were grown. XPS results confirmed the incorporated cerium in tetravalence. PL emission exhibited 5d ? 4f transition on cerium doping. Doped ZnO decolorizes MB faster than undoped ZnO.

  1. Kondo lattice and antiferromagnetic behavior in quaternary CeTAl4Si2 (T = Rh, Ir) single crystals

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

    Maurya, Arvind; Kulkarni, Ruta; Thamizhavel, Arumugam; Paudyal, Durga; Dhar, Sudesh Kumar

    2016-02-26

    Here, we have explored in detail the anisotropic magnetic properties of CeRhAl4Si2 and CeIrAl4Si2, which undergo two antiferromagnetic transitions, at TN1 = 12.6 and 15.5 K, followed by a second transition at TN2 = 9.4 and 13.8 K, respectively, with the [001]-axis as the relatively easy axis of magnetization. The electrical resistivity at ambient and applied pressure provides evidence of Kondo interaction in both compounds, further supported by a reduced value of the entropy associated with the magnetic ordering. The Sommerfeld coefficient γ is inferred to be 195.6 and 49.4 mJ/(mol K2) for CeRhAl4Si2 and CeIrAl4Si2, respectively, classifying these materialsmore » as moderate heavy-fermion compounds. The crystal electric field energy levels are derived from the peak seen in the Schottky heat capacity. Furthermore, we have also performed electronic structure calculations by using the local spin density approximation + U [LSDA+U] approach, which provide physical insights on the observed magnetic behavior of these two compounds.« less

  2. Superior performance of Ni-W-Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

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

    Rodriguez, Jose A.; Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; Johnson-Peck, Aaron C.; Zhao, Fuzhen; Michorczyk, Piotr; Kubacka, Anna; Stach, Eric A.; Fernandez-Garica, Marcos; et al

    2014-11-26

    The ethanol steam reforming (ESR) reaction was studied over a series of Ni-W-Ce oxide catalysts. The structures of the catalysts were characterized using in-situ techniques including X-ray diffraction, Pair Distribution Function, X-ray absorption fine structure and transmission electron microscopy; while possible surface intermediates for the ESR reaction were investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy. In these materials, all the W and part of the Ni were incorporated into the CeO? lattice, with the remaining Ni forming highly dispersed nano NiO (moreThe Ni-W-Ce systeme exhibited a much larger lattice strain than those seen for Ni-Ce and W-Ce. Synergistic effects between Ni and W inside ceria produced a substantial amount of defects and O vacancies that led to high catalytic activity, selectivity and stability (i.e. resistance to coke formation) during ethanol steam reforming.less

  3. Soil erosion rates caused by wind and saltating sand stresses in a wind tunnel

    SciTech Connect (OSTI)

    Ligotke, M.W.

    1993-02-01

    Wind erosion tests were performed in a wind tunnel in support of the development of long-term protective barriers to cap stabilized waste sites at the Hanford Site. Controlled wind and saltating sand erosive stresses were applied to physical models of barrier surface layers to simulate worst-case eolian erosive stresses. The goal of these tests was to provide information useful to the design and evaluation of the surface layer composition of an arid-region waste site barrier concept that incorporates a deep fine-soil reservoir. A surface layer composition is needed that will form an armor resistant to eolian erosion during periods of extreme dry climatic conditions, especially when such conditions result in the elimination or reduction of vegetation by water deprivation or wildfire. Because of the life span required of Hanford waste barriers, it is important that additional work follow these wind tunnel studies. A modeling effort is planned to aid the interpretation of test results with respect to the suitability of pea gravel to protect the finite-soil reservoir during long periods of climatic stress. It is additionally recommended that wind tunnel tests be continued and field data be obtained at prototype or actual barrier sites. Results wig contribute to barrier design efforts and provide confidence in the design of long-term waste site caps for and regions.

  4. Geologic report on the Sand Wash Drilling Project, Moffat and Routt Counties, Colorado

    SciTech Connect (OSTI)

    Carter, T.E.; Wayland, T.E.

    1981-09-01

    The Sand Wash Basin Drilling Project comprises twenty-seven (27) drill holes located in Moffat and Routt Counties, northwest Colorado, having an aggregate depth of 26,107.5 feet (7957.6 m). The holes penetrate the Browns Park Formation of Miocene age, which is a tuffaceous continental sandstone deposited in fluvial, eolian, and lacustrine environments. Partly based on project drilling results, uranium potential resource estimates for this formation in the $50/lb U/sub 3/O/sub 8/ forward-cost category have been increased by 34,476 tons U/sub 3/O/sub 8/ (35,036 metric tons). Three areas between Maybell and Craig, Colorado, considered favorable for uranium occurrences were verified as favorable by project drilling, and a fourth favorable area northwest of Maybell has been expanded. In addition, project drilling results indicate two new favorable areas, one north and northwest and one south of Steamboat Springs, Colorado. Anomalous radioactivity was detected in drill holes in all six study areas of the project. The most important factor in concentrating significant amounts of uranium in the target formation appears to be the availability of gaseous or liquid hydrocarbons and/or hydrogen sulfide gas as reductants. Where subjacent formations supply these reductants to the Browns Park Formation, project drilling encountered 0.05 percent to 0.01 percent uranium concentrations. Potential, though unproven, sources of these reductants are believed to underlie parts of all six project study areas.

  5. Experimental results of single screw mechanical tests: a follow-up to SAND2005-6036.

    SciTech Connect (OSTI)

    Lee, Sandwook; Lee, Kenneth L.; Korellis, John S.; McFadden, Sam X.

    2006-08-01

    The work reported here was conducted to address issues raised regarding mechanical testing of attachment screws described in SAND2005-6036, as well as to increase the understanding of screw behavior through additional testing. Efforts were made to evaluate fixture modifications and address issues of interest, including: fabrication of 45{sup o} test fixtures, measurement of the frictional load from the angled fixture guide, employment of electromechanical displacement transducers, development of a single-shear test, and study the affect of thread start orientation on single-shear behavior. A286 and 302HQ, No.10-32 socket-head cap screws were tested having orientations with respect to the primary loading axis of 0{sup 0}, 45{sup o}, 60{sup o}, 75{sup o} and 90{sup o} at stroke speeds 0,001 and 10 in/sec. The frictional load resulting from the angled screw fixture guide was insignificant. Load-displacement curves of A286 screws did not show a minimum value in displacement to failure (DTF) for 60{sup o} shear tests. Tests of 302HQ screws did not produce a consistent trend in DTF with load angle. The effect of displacement rate on DTF became larger as shear angle increased for both A286 and 302HQ screws.

  6. Engineering report on drilling in the Sand Wash Basin intermediate grade project

    SciTech Connect (OSTI)

    1980-09-01

    The Sand Wash Basin Intermediate Grade Drilling Project was conducted by Bendix Field Engineering Corporation in support of the US Department of Energy (DOE) National Uranium Resource Evaluation (NURE) program. This project consisted of 19 drill holes ranging in depth from 275 to 1220 feet (83.9 to 372.1 m). A total of 11,569 feet (3528.5 m) was rotary drilled and 130 feet (39.7 m) were cored for a total of 11,699 feet (3568.2 m) for the project. The project objective was to provide comprehensive subsurface geologic data relevant to Intermediate Grade uranium mineralization of the Browns Park Formation in the Sugar Loaf Peak Site A, and the Little Juniper Mountain Site B areas. All boreholes are located on the USGS Juniper Hot Springs and the Lay 7.5-Minute Series (Topographic) Quadrangles. The project began May 2, 1980; drilling was completed June 3, 1980. Site restoration and clean up was initiated immediately upon the completion of the last borehole and was completed June 8, 1980.

  7. Engineering report on drilling in the Sand Wash Basin, Colorado. [In support of NURE program

    SciTech Connect (OSTI)

    Callihan, M C

    1980-01-01

    The Sand Wash Basin Drilling project was conducted by Bendix Field Engineering Corporation in support of the US Department of Energy (DOE) National Uranium Resource Evaluation (NURE) program. This project consisted of 27 drill holes ranging in depth from 110 feet (33.5 m) to 1,995 feet (608.1 m). A total of 25,514 feet (7,471.9 m) was rotary drilled, and 1,593.5 feet (485.7 m) were cored resulting in a total of 26,107.5 feet (7,957.6 m) drilled for the project. The objective of the project was to provide comprehensive subsurface geologic data relevant to uranium mineralization. This was accomplished by drilling in major outcrop areas of the Browns Park Formation in Moffat and Routt Counties, Colorado. The project began May 18, 1979; drilling was completed November 4, 1979. Most site restoration and cleanup was completed during the fall of 1979 with the remainder to be completed during the spring of 1980.

  8. Stratigraphy and petroleum potential of Trout Creek and Twentymile sandstones (Upper Cretaceous), Sand Wash Basin, Colorado

    SciTech Connect (OSTI)

    Siepman, B.R.

    1985-05-01

    The Trout Creek and Twentymile Sandstones (Mesaverde Group) in Moffat and Routt Counties, Colorado, are thick, upward-coarsening sequences that were deposited along the western margin of the Western Interior basin during Campanian time. These units trend northeast-southwest and undergo a facies change to coal-bearing strata on the northwest. Surface data collected along the southeastern rim of the Sand Wash basin were combined with well-log data from approximately 100 drill holes that have penetrated the Trout Creek or Twentymile in the subsurface. The sandstones exhibit distinctive vertical profiles with regard to grain size, sedimentary structures, and biogenic structures. A depositional model that incorporates the key elements of the modern Nile River (northeast Africa) and Nayarit (west-central Mexico) coastal systems is proposed for the Trout Creek and Twentymile sandstones and associated strata. The model depicts a wave-dominated deltaic, strand-plain, and barrier-island system. Depositional cycles are asymmetrical in cross section as they are largely progradational and lack significant transgressive deposits. Source rock-reservoir rock relationships are ideal as marine shales underlie, and coal-bearing strata overlie sheetlike reservoir sandstones. Humic coal, the dominant source of Mesaverde gas, generates major quantities of methane upon reaching thermal maturity. Existing Mesaverde gas fields are largely structural traps, but stratigraphic and combination traps may prove to be equally important. The sparsely drilled deeper part of the basin warrants testing as large, overpressured-gas accumulations in tight-sandstone reservoirs are likely to be found.

  9. Future directions in advanced exploratory research related to oil, gas, shale and tar sand resources

    SciTech Connect (OSTI)

    Not Available

    1987-01-01

    The Office of Technical Coordination (OTC) is responsible for long-range, high-risk research that could provide major advances in technologies for the use of fossil fuels. In late 1986, OTC was given responsibility for an existing program of research in Advanced Process Technology (APT) for oil, gas, shale, and tar sands. To meet these challenges and opportunities, the OTC approached the National Research Council with a request to organize an advisory panel to examine future directions in fundamental research appropriate for sponsorship by the Advanced Process Technology program. An advisory group was formed with broad representation from the geosciences, physical sciences, and engineering disciplines to accomplish this task. The charge to the panel was to prepare a report for the director of the Office of Technical Coordination, identifying critical research areas. This report contains the findings and recommendations of the panel. It is written both to advise the research management of the Department of Energy on research opportunities and needs, and to stimulate interest and involvement in the research community in fundamental research related to fossil energy, and in particular, oil and gas resources. 1 tab.

  10. Qualitative risk assessment of Sandia`s rocket preparation and launch facility at Barking Sands, Kauai

    SciTech Connect (OSTI)

    Mahn, J.A.

    1997-12-31

    This paper demonstrates the application of a qualitative methodology for performing risk assessments using the consequence and probability binning criteria of DOE Order 5481.1B. The particular application that is the subject of this paper is a facility risk assessment conducted for Sandia National Laboratories` Kauai Test Facility (KTF). The KTF is a rocket preparation and launch facility operated by Sandia National Laboratories for the Department of Energy and is located on the US Navy`s Pacific Missile Range Facility (PMRF) at Barking Sands on the western side of the island of Kauai, Hawaii. The KTF consists of an administrative compound and main launch facility located on the north end of the PMRF, as well as the small Kokole Point launch facility located on the south end of the PMRF. It is classified as a moderate hazard facility in accordance with DOE Order 5481.1B. As such, its authorization basis for operations necessitates a safety/risk assessment. This paper briefly addresses the hazards associated with KTF operations and the accidents selected for evaluation, introduces the principal elements of the accident assessment methodology, presents analysis details for two of the selected accidents, and provides a summary of results for all of the accidents evaluated.

  11. Impact of early diagenesis of Eolian reservoirs, Great Sand Dunes National Monument, Colorado

    SciTech Connect (OSTI)

    Krystinik, L.F.; Andrews, S.; Fryberger, S.G.

    1985-02-01

    Dune and associated alluvial and playa deposits at Great Sand Dunes National Monument, Colorado, provide an excellent opportunity to study early diagenetic development of vertical and horizontal permeability barriers in recent eolian deposits (> 10 ka). Cements observed include calcite, aragonite, protodolomite(.), amorphous silica, iron hydroxide, smectite, trona, and halite. Cementation is controlled by the availability of water, with several hydrologic subenvironments producing different cements. Evaporative cementation in dunes adjacent to playas is commonly dominated by trona and halite, but calcite, aragonite, and amorphous silica also bind the sediment. These cements are generally most concentrated in fine laminations where capillary action has pulled water into dunes. Iron hydroxides, calcite, and amorphous silica precipitate at the interface between ground water and streams or lakes, where the pH gradient may exceed 5 pH units (pH 5.7-11.5). Subsequent movement of the ground-water table can result in cross-cutting cement zones. Early cementation in dunes prevents deflation and provides a mechanism for preservation of the reservoir unit. Intense cementation may permanently occlude porosity, or leaching may reestablish well-interconnected porosity. An understanding of the extent and composition of early cement zones can be used to improve hydrodynamic models for production and enhanced recovery.

  12. Synthesis, Structures, and Magnetic Properties of Rare-Earth Cobalt Arsenides, RCo2As2 (R = La, Ce, Pr, Nd)

    SciTech Connect (OSTI)

    Thompson, Corey; Tan, Xiaoyan; Kovnir, Kirill; Garlea, Vasile O; Shatruk, Michael

    2014-01-01

    Four rare-earth cobalt arsenides, RCo2As2 (R = La, Ce, Pr, Nd), were obtained by reactions of constituent elements in molten Bi. The use of Bi flux also allowed the growth of representative single crystals. All compounds are isostructural and belong to the ThCr2Si2 structure type (space group I4/mmm). The formation of Co vacancies is observed in all structures, while the structures of La- and Ce-containing compounds also show incorporation of minor Bi defects next to the R crystallographic site. Correspondingly, the general formula of these materials can be written as R1 xBixCo2 As2, with x/ = 0.03/0.1, 0.05/0.15, 0/0.2, and 0/0.3 for R = La, Ce, Pr, and Nd, respectively. All compounds exhibit high-temperature ferromagnetic ordering of Co magnetic moments in the range of 150-200 K. Electronic band structure calculations revealed a high peak in the density of states at the Fermi level, thus supporting the itinerant nature of magnetism in the Co sublattice. The magnetic ordering in the lanthanide sublattice takes place at lower temperatures, with the R moments aligning antiparallel to the Co moments to give a ferrimagnetic ground state. The measurements on oriented single crystals demonstrated significant magnetic anisotropy in the ferrimagnetic state, with the preferred moment alignment along the c axis of the tetragonal lattice. Neutron powder diffraction failed to reveal the structure of magnetically ordered states, but confirmed the presence of Co vacancies. X-ray absorption near-edge structure spectroscopy on Ce1.95Bi0.05Co1.85As2 showed the average oxidation state of Ce to be +3.06. Solid state NMR spectroscopy revealed a substantially reduced hyperfine field on the Co atoms in the vicinity of Bi defects.

  13. Ionic liquid-assisted sonochemical preparation of CeO2 nanoparticles for CO oxidation

    SciTech Connect (OSTI)

    Alammar, Tarek; Noei, Heshmat; Wang, Yuemin; Grünert, Wolfgang; Mudring, Anja -Verena

    2014-10-10

    CeO2 nanoparticles were synthesized via a one-step ultrasound synthesis in different kinds of ionic liquids based on bis(trifluoromethanesulfonylamide, [Tf2N], in combination with various cations including 1-butyl-3-methylimidazolium ([C4mim]+), 1-ethyl-2,3-dimethylimidazolium ([Edimim]+), butyl-pyridinium([Py4]+), 1-butyl-1-methyl-pyrrolidinium ([Pyrr14]+), and 2-hydroxyethyl-trimethylammonium ([N1112OH]+). Depending on synthetic parameters, such as ionic liquid, Ce(IV) precursor, heating method, and precipitator, formed ceria exhibits different morphologies, varying from nanospheres, nanorods, nanoribbons, and nanoflowers. The morphology, crystallinity, and chemical composition of the obtained materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), Raman spectroscopy, and N2 adsorption. The structural and electronic properties of the as-prepared CeO2 samples were probed by CO adsorption using IR spectroscopy under ultrahigh vacuum conditions. The catalytic activities of CeO2 nanoparticles were investigated in the oxidation of CO. CeO2 nanospheres obtained sonochemically in [C4mim][Tf2N] exhibit the best performance for low-temperature CO oxidation. As a result, the superior catalytic performance of this material can be related to its mesoporous structure, small particle size, large surface area, and high number of surface oxygen vacancy sites.

  14. FMM NEAMS Project Report/ SAND Report 2010-6707P Upscaling Atomistic Mechanisms to Continuum Models For Nuclear Waste Glass

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

    FMM NEAMS Project Report/ SAND Report 2010-6707P Upscaling Atomistic Mechanisms to Continuum Models For Nuclear Waste Glass Dissolution September 2010 Louise J. Criscenti and David Sassani Sandia National Laboratories, MS 0754, PO Box 5800, Albuquerque, NM 98185 Abstract - The aim of this report is to extend understanding and capability for linking atomistic understanding of glass corrosion mechanisms to continuum models of reaction and transport in the subsurface environment. The focus of this

  15. Studies of the terrestrial O{sub 2} and carbon cycles in sand dune gases and in biosphere 2

    SciTech Connect (OSTI)

    Severinghaus, J.P.

    1995-12-31

    Molecular oxygen in the atmosphere is coupled tightly to the terrestrial carbon cycle by the processes of photosynthesis, respiration, and burning. This dissertation examines different aspects of this coupling in four chapters. Chapter 1 explores the feasibility of using air from sand dunes to reconstruct atmospheric O{sub 2} composition centuries ago. Such a record would reveal changes in the mass of the terrestrial biosphere, after correction for known fossil fuel combustion, and constrain the fate of anthropogenic CO{sub 2}.

  16. Bioprocessing-Based Approach for Bitumen/Water/Fines Separation and Hydrocarbon Recovery from Oil Sands Tailings

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

    Brigmon, Robin L.; Berry, Christopher J.; Wade, Arielle; Simpson, Waltena

    2016-05-04

    Oil sands are a major source of oil, but their industrial processing generates tailings ponds that are an environmental hazard. The main concerns are mature fine tailings (MFT) composed of residual hydrocarbons, water, and fine clay. Tailings ponds include toxic contaminants such as heavy metals, and toxic organics including naphthenics. Naphthenic acids and polyaromatic hydrocarbons (PAHs) degrade very slowly and pose a long-term threat to surface and groundwater, as they can be transported in the MFT. Research into improved technologies that would enable densification and settling of the suspended particles is ongoing. In batch tests, BioTiger™, a microbial consortium thatmore » can metabolize PAHs, demonstrated improved oil sands tailings settling from a Canadian tailings pond. Results also showed, depending on the timing of the measurements, lower suspended solids and turbidity. Elevated total organic carbon was observed in the first 48 hours in the BioTiger™-treated columns and then decreased in overlying water. Oil sands tailings mixed with BioTiger™ showed a two-fold reduction in suspended solids within 24 hours as compared to abiotic controls. The tailings treated with BioTiger™ increased in microbial densities three orders of magnitude from 8.5 × 105 CFU/mL to 1.2 × 108 CFU/mL without any other carbon or energy source added, indicating metabolism of hydrocarbons and other available nutrients. Results demonstrated that bioaugmentation of BioTiger™ increased separation of organic carbon from particles in oil sands and enhanced settling with tailings with improved water quality.« less

  17. Safety-analysis report for packaging - corrugated steel container (SAND Box) for DOT specification 7A packaging

    SciTech Connect (OSTI)

    Brugger, R.P.

    1983-05-16

    Department of Transportation (DOT) Specification 7A, Type A corrugated steel containers for shipment and storage of Transuranic (TRU) solid waste have been developed. The containers are made entirely of 14 gauge (0.0747-in.) low carbon steel. All seams including the closure are welded to produce a leak-tight container. Four sizes of the SAND Box container have successfully met all Specification 7A, Type A requirements.

  18. Safety analysis report for packaging-corrugated steel container (SAND Box) for DOT Specification 7A packaging

    SciTech Connect (OSTI)

    Brugger, R.P.

    1983-01-24

    Department of Transportation (DOT) Specification 7A, Type A corrugated steel containers for shipment and storage of Transuranic (TRU) solid waste have been developed. The containers are made entirely of 14 gauge (0.0747-in.) low carbon steel. All seams including the closure are welded to produce a leaktight container. Four sizes of the SAND Box container have successfully met all Specification 7A, Type A requirements.

  19. Dependence of waterflood remaining oil saturation on relative permeability, capillary pressure, and reservoir parameters in mixed wet, turbidite sands

    SciTech Connect (OSTI)

    Hirasaki, G.J.

    1995-12-31

    The dependence of waterflood oil recovery on relative permeability, capillary pressure, and reservoir parameters was investigated by numerical simulation. The relative permeability and capillary pressure curves were based on laboratory measurements on unconsolidated sands and were evaluated for water-wet and mixed wet states. The reservoir model was a prototype turbidite sand with a range of thickness and permeability values. The economic oil recovery was based on an economic limit water cut of 50%. The remaining oil saturation in the swept region for the water-wet cases was close to the residual oil saturation. The remaining oil saturation of the mixed wet cases ranged from low values near the residual oil saturation to far above the residual oil saturation. It is dependent on the reservoir parameters that govern: (1) the vertical {open_quotes}film surface drainage{close_quotes} of oil by gravity, (2) accumulation of a high oil saturation and thus a high relative permeability under the cap rock, (3) updip migration of the oil that accumulated under the cap rock. The dependence on the reservoir parameters can be summarized by dimensionless groups. There is a dimensionless time for the vertical displacement of oil by gravity. The accumulation of a high oil saturation under the cap rock is dependent on the ratio of the capillary transition zone and the sand thickness. The updip migration is dependent on a combination of the gravity number and the end point mobility ratio.

  20. A methodology to assess the radionuclide migration parameters through bentonite-sand backfill in a short experimental duration

    SciTech Connect (OSTI)

    Gurumoorthy, C.; Kusakabe, O.

    2007-07-01

    Bentonite-Sand Backfill is a part of Engineered Barrier System (EBS) widely used in a Near Surface Disposal Facility (NSDF) to delay migration of radionuclides from the disposed nuclear waste in a geo environment. Laboratory migration experiments have been conducted to understand the advection/diffusion mechanisms of various radionuclides through backfill and to evaluate their migration rates in order to assess the performance of EBS. Migration through backfill is an extremely slow process and the experiments are time consuming. Also, these experiments have limitations to simulate the field stress conditions. Various researchers have experienced the advantages of centrifuge modeling technique to model contaminant transport problems of geo-environment. However, no such studies have been carried out adopting this technique to model the behaviour of bentonite-sand mixture as backfill in NSDF. An attempt has been made in the present study to investigate the validity of this technique to carry out such studies. Significance of geotechnical centrifuge modeling to simulate the prototype radionuclide migration mechanisms through backfill is highlighted. This paper presents the dimensional analysis of various scale factors to construct a physical model for centrifuge tests to monitor online the migration phenomena of radionuclides through bentonite-sand mixture. Studies reveal the feasibility of the technique to evaluate the migration parameters in a short experimental duration. Such studies help in improving EBS design and assessing the long-term performance of EBS in NSDF. (authors)

  1. Permeability of laboratory-formed methane-hydrate-bearing sand: Measurements and observations using x-ray computed tomography

    SciTech Connect (OSTI)

    Kneafsey, T. J.; Seol, Y.; Gupta, A.; Tomutsa, L.

    2010-09-15

    Methane hydrate was formed in two moist sands and a sand/silt mixture under a confining stress in an X-ray-transparent pressure vessel. Three initial water saturations were used to form three different methane-hydrate saturations in each medium. X-ray computed tomography (CT) was used to observe location-specific density changes caused by hydrate formation and flowing water. Gas-permeability measurements in each test for the dry, moist, frozen, and hydrate-bearing states are presented. As expected, the effective permeabilities (intrinsic permeability of the medium multiplied by the relative permeability) of the moist sands decreased with increasing moisture content. In a series of tests on a single sample, the effective permeability typically decreased as the pore space became more filled, in the order of dry, moist, frozen, and hydrate-bearing. In each test, water was flowed through the hydrate-bearing medium and we observed the location-specific changes in water saturation using CT scanning. We compared our data to a number of models, and our relative permeability data compare most favorably with models in which hydrate occupies the pore bodies rather than the pore throats. Inverse modeling (using the data collected from the tests) will be performed to extend the relative permeability measurements.

  2. Reverse micelles directed synthesis of TiO{sub 2}-CeO{sub 2} mixed oxides and investigation of their crystal structure and morphology

    SciTech Connect (OSTI)

    Matejova, Lenka; Vales, Vaclav; Fajgar, Radek; Matej, Zdenek; Holy, Vaclav; Solcova, Olga

    2013-02-15

    The synthesis of TiO{sub 2}-CeO{sub 2} mixed oxides based on the sol-gel process controlled within reverse micelles of non-ionic surfactant Triton X-114 in cyclohexane is reported. The crystallization, phase composition, trends in nanoparticles growth and porous structure properties are studied as a function of Ti:Ce molar composition and annealing temperature by in-situ X-ray diffraction, Raman spectroscopy and physisorption. The brannerite-type CeTi{sub 2}O{sub 6} crystallizes as a single crystalline phase at Ti:Ce molar composition of 70:30 and in the mixture with cubic CeO{sub 2} and anatase TiO{sub 2} for composition 50:50. At Ti:Ce molar ratios 90:10 and 30:70 the mixtures of TiO{sub 2} anatase, rutile and cubic CeO{sub 2} appear. In these mixtures TiO{sub 2} rutile is formed at higher temperatures than conventionally. Additionally, the amount of a present amorphous phase in individual mixtures was estimated from diffraction data. The porous structure morphology depends both on molar composition and annealing temperature. This is correlated with the presence of carbon impurities of different character. - Graphical abstract: The phase composition of Ti90--Ce10 and Ti50--Ce50 oxide mixtures as a function of annealing temperature. The amount of the amorphous phase was estimated and attributed to TiO{sub 2}. Highlights: Black-Right-Pointing-Pointer Ti/Ce oxides were prepared using reverse micelles of Triton X-114. Black-Right-Pointing-Pointer Crystallization of TiO{sub 2}, CeO{sub 2} or CeTi{sub 2}O{sub 6} depends on Ti:Ce molar ratio. Black-Right-Pointing-Pointer Amorphous phase attributed to TiO{sub 2} was identified. Black-Right-Pointing-Pointer Metal oxides surface area is influenced by the character of present carbon impurities.

  3. Design and Implementation of Energized Fracture Treatment in Tight Gas Sands

    SciTech Connect (OSTI)

    Mukul Sharma; Kyle Friehauf

    2009-12-31

    Hydraulic fracturing is essential for producing gas and oil at an economic rate from low permeability sands. Most fracturing treatments use water and polymers with a gelling agent as a fracturing fluid. The water is held in the small pore spaces by capillary pressure and is not recovered when drawdown pressures are low. The un-recovered water leaves a water saturated zone around the fracture face that stops the flow of gas into the fracture. This is a particularly acute problem in low permeability formations where capillary pressures are high. Depletion (lower reservoir pressures) causes a limitation on the drawdown pressure that can be applied. A hydraulic fracturing process can be energized by the addition of a compressible, sometimes soluble, gas phase into the treatment fluid. When the well is produced, the energized fluid expands and gas comes out of solution. Energizing the fluid creates high gas saturation in the invaded zone, thereby facilitating gas flowback. A new compositional hydraulic fracturing model has been created (EFRAC). This is the first model to include changes in composition, temperature, and phase behavior of the fluid inside the fracture. An equation of state is used to evaluate the phase behavior of the fluid. These compositional effects are coupled with the fluid rheology, proppant transport, and mechanics of fracture growth to create a general model for fracture creation when energized fluids are used. In addition to the fracture propagation model, we have also introduced another new model for hydraulically fractured well productivity. This is the first and only model that takes into account both finite fracture conductivity and damage in the invaded zone in a simple analytical way. EFRAC was successfully used to simulate several fracture treatments in a gas field in South Texas. Based on production estimates, energized fluids may be required when drawdown pressures are smaller than the capillary forces in the formation. For this field

  4. Movement of tagged dredged sand at thalweg disposal sites in the Upper Mississippi River. Volume 3. Additional results at Gordon's Ferry and Whitney Island sites

    SciTech Connect (OSTI)

    McCown, D.L.; Paddock, R.A.

    1985-04-01

    During routine channel maintenance, hydraulically dredged sand was tagged with sand coated with fluorescent dye before being deposited as a pile in the thalweg at three sites on the Upper Mississippi River. As discussed in the first two volumes of this report, bathymetry was measured and surface sediments were sampled to study changes in the topography of the disposal pile and the downstream movement of the tagged sand. At all three sites, topographic evidence of the pile disappeared after the first period of high river flow, which was followed by redevelopment of dunes in the disposal area. The tagged sand did not migrate into nearby border areas, backwaters, or sloughs, remaining in the main channel as it moved downstream. This volume presents the results of additional surveys at the Gordon's Ferry and Whitney Island sites. At Gordon's Ferry, 25 bottom cores were taken to examine the three-dimensional distribution of tagged sand in the bottom sediments. The core analyses indicated that much of the tagged sand had been incorporated into the dune structure and that it resided primarily in the crests of the dunes.

  5. Molybdenum carbide nanoparticles as catalysts for oil sands upgrading: Dynamics and free-energy profiles

    SciTech Connect (OSTI)

    Liu, Xingchen; Salahub, Dennis R.

    2015-12-31

    There is no doubt that a huge gap exists in understanding heterogeneous catalysis between a cluster model of a few atoms and a bulk model of periodic slabs. Nanoparticles, which are crucial in heterogeneous catalysis in industry, lie in the middle of the gap. We present here our work on the computational modelling of molybdenum carbide nanoparticles (MCNPs) as the catalysts for the upgrading of oil sands in the in-situ environment, using benzene hydrogenation as a model reaction. With a cluster model, efforts were first made to understand the mechanism of the reaction with a density functional theory (DFT) study on the adsorption of benzene and its hydrogenation product – cyclohexane, as well as the cyclic hydrogenation reaction intermediates on the Mo{sub 2}C(0001) surface. From the thermodynamic data, along with literature information, it was found that the benzene hydrogenation reaction on molybdenum carbide happens most likely through a Langmuir-Hinshelwood mechanism with the gradual lifting up of the benzene molecule. The electron localization function (ELF) was then used to help understand the nature of the interactions between the MCNPs, identifying strong multi-center interactions between the adsorbates and the MCNPs. To enable the treatment of larger nanoparticles, a fast semi-empirical density functional tight-binding (DFTB) method was parameterized. With this method, the potential energy profiles of benzene hydrogenation reactions on different sizes of MCNPs are calculated. The study was then extended to consider a MCNP embedded in solvent (benzene), using a quantum mechanical (DFTB) / molecular mechanical approach. Calculations on the free energies profiles with the umbrella sampling method show that the entropy of the MCNPs and the solvent are essential in understanding the catalytic activity of the transition metal related nanoparticles for solid/liquid heterogeneous catalysis.

  6. Statistical planning and analysis for treatments of tar sand wastewater. Final report

    SciTech Connect (OSTI)

    Pirie, W.R.

    1984-03-01

    The first part of this report discusses the overall statistical planning, coordination and design for several tar sand wastewater treatment projects contracted by the Laramie Energy Technology Center (LETC) of the Department of Energy. A general discussion of the benefits of consistent statistical design and analysis for data-oriented projects is included, with recommendations for implementation. A detailed outline of the principles of general linear models design is followed by an introduction to recent developments in general linear models by ranks (GLMR) analysis and a comparison to standard analysis using Gaussian or normal theory (GLMN). A listing of routines contained in the VPI Nonparametric Statistics Package (NPSP), installed on the Cyber computer system at the University of Wyoming is included. Part 2 describes in detail the design and analysis for treatments by Gas Flotation, Foam Separation, Coagulation, and Ozonation, with comparisons among the first three methods. Rank methods are used for most analyses, and several detailed examples are included. For optimization studies, the powerful tools of response surface analysis (RSA) are employed, and several sections contain discussion on the benefits of RSA. All four treatment methods proved to be effective for removal of TOC and suspended solids from the wastewater. Because the processes and equipment designs were new, optimum removals were not achieved by these initial studies and reasons for that are discussed. Pollutant levels were nevertheless reduced to levels appropriate for recycling within the process, and for such reuses as steam generation, according to the DOE/LETC project officer. 12 refs., 8 figs., 21 tabs.

  7. Synthesis and characterization of black, red and yellow nanoparticles pigments from the iron sand

    SciTech Connect (OSTI)

    Mufti, Nandang Atma, T. Fuad, A.; Sutadji, E.

    2014-09-25

    The aim of this research is to synthesize nanoparticles of black pigment of Magnetite (Fe{sub 3}O{sub 4}), red pigment of hematite (α-Fe{sub 2}O{sub 3}), and yellow pigment of ghoetite (α-FeOOH) from the iron sand. The black pigment of Fe{sub 3}O{sub 4} and the yellow pigment α-FeOOH nanoparticles were synthesized by coprecipitation method with variation of pH. Whereas, the red pigment Fe{sub 2}O{sub 3} was synthesized by sintering Fe{sub 3}O{sub 4} nanoparticles at temperature between 400 °C and 700 7°C for 1 hour. All the pigments has been characterized using X-ray diffraction and SEM. The XRD results shown that the particle size of the black pigmen Fe{sub 3}O{sub 4}, red pigment Fe{sub 3}O{sub 4} and yellow pigment α-FeOOH are around 12, 32, and 30 nm respectively. The particle size of Fe{sub 2}O{sub 3} nanoparticles increase by increasing sintering temperature from 32 nm at 400 °C to 39 nm at 700 °C. For yellow pigment of α-FeOOH, the particle size increase by increasing pH from 30,54 nm at pH 4 to 48,60 nm at pH 7. The SEM results shown that the morphologies of black, yellow and red pigments are aglomarated.

  8. Western gas sands project. Status report, July-August-September 1981

    SciTech Connect (OSTI)

    1981-03-01

    The progress during July, August and September 1981 on increasing gas production from low permeability gas sands of the Western United States, is summarized in this edition of the WGSP Quarterly Status Report. During the quarter, CK GeoEnergy completed the field work in the Rifle Gap area near Rifle, Colorado, as well as the Draft Phase VI report covering the prognosis about reservoir geometry in the Multi-Well site area. The improved pressure coring system project, officially terminated Sept. 30. Accomplishments included increased capabilities for the pressure core barrel, improvements in the low invasion fluid plus various laboratory core intrusion studies and improved designs for PDC drill bits. At Lawrence Livermore National Laboratory, the P/sup 2/L/sup 2/ system described last quarter was evaluated further and the decision has been made to abandon further investigation. The Los Alamos National Laboratory Ceramics Materials Group is preparing to fabricate a ceramic sample with cylindrical pores of specified diameters. The NMR data on this type sample will contribute to a better understanding of the parameters affecting NMR relaxation rates in porous media. During the quarter, modifications were made in the operating and application software of the DOE Well Test Facility, which will support additions to the PDP-11/10 computer system. The Multi-Well Experiment well was spudded on Sept. 13 and by Sept. 30, total depth was 3358 ft. Coring operations are expected to begin at a depth of 4150 ft. At the Nevada Test Site, Sandia National Laboratories completed four additional coreholes for the Fluid Mechanics/ Proppant Transport Experiments.

  9. Expansion of decline curve parameters for tight gas sands with massive hydraulic fractures

    SciTech Connect (OSTI)

    Schaefer, T.

    1995-12-31

    With the advances in modern hydrocarbon technology and expansion of geologic settings for development, it is necessary to make changes to the conventional wisdoms that accompany production technology. This paper discusses some possible changes that necessitate implementation as observed both empirically and analytically. Specifically it discusses the time at which a decline curve can be implemented for production forecasting, the need for a dual decline model, and the severity of the decline variable that may be used for this model. It is the point of this paper to prove that for fight gas sands with massive hydraulic fractures that it is not only feasible to use decline variables that are greater than the traditional limit of harmonic or 1.0, but that the decline curve may also be implemented in the transient flow period of the well and decline both hyperbolically and exponentially. These ideas were not only proven through field study, but were additionally modeled with a fracture flow simulator. In order to prove these points this paper first introduces the Red Fork Formation and the development of an initial field model curve for this formation. After the initial model was developed, questions arose as to its feasibility. These questions were first addressed with a literature survey and further comparisons were made to test the models accuracy using pressure decline analysis and a fracture flow simulator. All of these methods were used to justify the implementation of a decline exponent as high as 2.1 for a hyperbolic curve during the early transient flow period, and regressing this hyperbolic into an exponential decline in the pseudo-steady state period.

  10. Structural and magnetic phase transitions in CeCu6-xTx (T = Ag,Pd)

    SciTech Connect (OSTI)

    Poudel, Lekhanath N.; De la cruz, Clarina; Payzant, E. Andrew; Koehler, Michael R.; May, Andrew F.; Garlea, Vasile O.; Taylor, Alice E.; Parker, David S.; Cao, Huibo B.; McGuire, Michael A.; Tian, Wei; Matsuda, Masaaki; Jeen, Hyoung Jeen; Lee, Ho Nyung; Hong, Tao; Calder, Stuart A.; Lumsden, Mark D.; Zhou, Haidong; Keppens, Veerle; Mandrus, D.; Christianson, Andrew D.

    2015-12-15

    The structural and the magnetic properties of CeCu6-xAgx (0 ≤ x ≤ 0.85) and CeCu6-xPdx (0 ≤ x ≤ 0.4) have been studied using neutron diffraction, resonant ultrasound spectroscopy (RUS), x-ray diffraction measurements, and first principles calculations. The structural and magnetic phase diagrams of CeCu6-xAgx and CeCu6-xPdx as a function of Ag/Pd composition are reported. The end member, CeCu6, undergoes a structural phase transition from an orthorhombic (Pnma) to a monoclinic (P21/c) phase at 240 K. In CeCu6-xAgx, the structural phase transition temperature (Ts) decreases linearly with Ag concentration and extrapolates to zero at xS ≈ 0.1. The structural transition in CeCu6-xPdx remains unperturbed with Pd substitution within the range of our study. The lattice constant b slightly decreases with Ag/Pd doping, whereas a and c increase with an overall increase in the unit cell volume. Both systems, CeCu6-xAgx and CeCu6-xPdx, exhibit a magnetic quantum critical point (QCP), at x ≈ 0.2 and x ≈ 0.05, respectively. Near the QCP, long range antiferromagnetic ordering takes place at an incommensurate wave vector (δ1 0 δ2), where δ1 ~ 0.62, δ2 ~ 0.25, x = 0.125 for CeCu6-xPdx and δ1 ~ 0.64, δ2 ~ 0.3, x = 0.3 for CeCu6-xAgx. As a result, the magnetic structure consists of an amplitude modulation of the Ce moments which are aligned along the c axis of the orthorhombic unit cell.

  11. Kondo hole behavior in Ce{sub 0.97} La{sub 0.03}Pd{sub 3}

    SciTech Connect (OSTI)

    Lawrence, J.M.; Graf, T.; Hundley, M.F.; Mandrus, D.; Thompson, J.D. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Lacerda, A.; Torikachvili, M.S. [National High Magnetic Field Laboratory, Pulse Facility, Los Alamos, New Mexico 87545 (United States)] [National High Magnetic Field Laboratory, Pulse Facility, Los Alamos, New Mexico 87545 (United States); Sarrao, J.L.; Fisk, Z. [National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306 (United States)] [National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306 (United States)

    1996-05-01

    We present results for the resistivity, the magnetoresistance, and the specific heat of Ce{sub 0.97}La{sub 0.03}Pd{sub 3} and CePd{sub 3}. The impurity contributions to these measurements follow the predictions of the single-impurity Kondo model for a Kondo temperature {ital T}{sub {ital L}}{approx_equal}65 K, assuming that the impurity behaves as a crystal-field split ({Gamma}{sub 7}) doublet. Assuming a {ital J}=5/2 impurity, the value of {ital T}{sub {ital L}} needed to fit these experiments varies from 65 to 125 K. The contribution to the susceptibility may be too small to be explained by the model. These results address whether the nonmagnetic impurity behaves as a Kondo hole. {copyright} {ital 1996 The American Physical Society.}

  12. Combined local-density and dynamical mean field theory calculations for the compressed lanthanides Ce, Pr, and Nd

    SciTech Connect (OSTI)

    McMahan, A K

    2005-03-30

    This paper reports calculations for compressed Ce (4f{sup 1}), Pr (4f{sup 2}), and Nd (4f{sup 3}) using a combination of the local-density approximation (LDA) and dynamical mean field theory (DMFT), or LDA+DMFT. The 4f moment, spectra, and the total energy among other properties are examined as functions of volume and atomic number for an assumed face-centered cubic (fcc) structure. These materials are seen to be strongly localized at ambient pressure and for compressions up through the experimentally observed fcc phases ({gamma} phase for Ce), in the sense of having fully formed Hund's rules moments and little 4f spectral weight at the Fermi level. Subsequent compression for all three lanthanides brings about significant deviation of the moments from their Hund's rules values, a growing Kondo resonance at the fermi level, an associated softening in the total energy, and quenching of the spin orbit since the Kondo resonance is of mixed spin-orbit character while the lower Hubbard band is predominantly j = 5/2. while the most dramatic changes for Ce occur within the two-phase region of the {gamma}-{alpha} volume collapse transition, as found in earlier work, those for Pr and Nd occur within the volume range of the experimentally observed distorted fcc (dfcc) phase, which is therefore seen here as transitional and not part of the localized trivalent lanthanide sequence. The experimentally observed collapse to the {alpha}-U structure in Pr occurs only on further compression, and no such collapse is found in Nd. These lanthanides start closer to the localized limit for increasing atomic number, and so the theoretical signatures noted above are also offset to smaller volume as well, which is possibly related to the measured systematics of the size of the volume collapse being 15%, 9%, and none for Ce, Pr, and Nd, respectively.

  13. Crystal structure and thermal expansion of a CsCe2Cl7 scintillator

    SciTech Connect (OSTI)

    Zhuravleva, M.; Lindsey, A.; Chakoumakos, B. C.; Custelcean, R.; Meilleur, F.; Hughes, R. W.; Kriven, W. M.; Melcher, C. L.

    2015-04-06

    Here we used single-crystal X-ray diffraction data to determine crystal structure of CsCe2Cl7. It crystallizes in a P1121/b space group with a = 19.352(1) Å, b = 19.352(1) Å, c = 14.838(1) Å, γ = 119.87(2) ° , and V = 4818.6(5) Å3. Differential scanning calorimetry measurements combined with the structural evolution of CsCe2Cl7 via X-ray diffractometry over a temperature range from room temperature to the melting point indicates no obvious intermediate solid-solid phase transitions. The anisotropy in the average linear coefficient of thermal expansion of the a axis (21.3 10-6/ °C) with respect to the b and c axes (27.0 10-6/ °C) was determined through lattice parameter refinement of the temperature dependent diffraction patterns. Lastly, these findings suggest that the reported cracking behavior during melt growth of CsCe2Cl7 bulk crystals using conventional Bridgman and Czochralski techniques may be largely attributed to the anisotropy in thermal expansion.

  14. One-, two-, and three-channel Kondo effects for a model Ce{sup 3+} impurity in a metal

    SciTech Connect (OSTI)

    Kim, T.; Cox, D.L.

    1997-05-01

    We present studies of a simple Anderson model Hamiltonian for Ce{sup 3+} ions in cubic symmetry with three configurations (f{sup 0},f{sup 1},f{sup 2}). In different parameter regimes, our model Hamiltonian maps to the one-, two-, and three-channel spin-1/2 Kondo models. Using third-order scaling (perturbative renormalization group) analysis, we study the stability of the non-Fermi-liquid fixed point of the two-channel Kondo model for Ce{sup 3+} ions in cubic symmetry against the one-channel Kondo interaction. Using the noncrossing approximation (NCA), we also report detailed studies for our simplified model of the competition between the Fermi-liquid fixed point of the one-channel Kondo model and the non-Fermi fixed points of the two- and three-channel Kondo models. We provide the phase diagram in the model parameter space and study the thermodynamics and the transport properties of our simplified model Hamiltonian. Thermodynamics and transport coefficients show distinct behaviors for different numbers of channels. We confirm in detail that the NCA is a valid numerical method for the overcompensated multichannel S{sub I}=1/2 Anderson models. Our model study might be relevant to the non-Fermi-liquid alloy Ce{sub 1{minus}x}La{sub x}Cu{sub 2.2}Si{sub 2}. {copyright} {ital 1997} {ital The American Physical Society}

  15. Strongly enhanced oxygen ion transport through samarium-doped CeO2 nanopillars in nanocomposite films

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

    Yang, Sang Mo; Lee, Shinbuhm; Jian, Jie; Zhang, Wenrui; Lu, Ping; Jia, Quanxi; Wang, Haiyan; Won Noh, Tae; Kalinin, Sergei V.; MacManus‐Driscoll, Judith L.

    2015-10-08

    Enhancement of oxygen ion conductivity in oxides is important for low-temperature (<500 °C) operation of solid oxide fuel cells, sensors and other ionotronic devices. While huge ion conductivity has been demonstrated in planar heterostructure films, there has been considerable debate over the origin of the conductivity enhancement, in part because of the difficulties of probing buried ion transport channels. Here we create a practical geometry for device miniaturization, consisting of highly crystalline micrometre-thick vertical nanocolumns of Sm-doped CeO2 embedded in supporting matrices of SrTiO3. The ionic conductivity is higher by one order of magnitude than plain Sm-doped CeO2films. Then bymore » using scanning probe microscopy, we show that the fast ion-conducting channels are not exclusively restricted to the interface but also are localized at the Sm-doped CeO2 nanopillars. Furthermore, this work offers a pathway to realize spatially localized fast ion transport in oxides of micrometre thickness.« less

  16. Influence of Electron Doping on Magnetic Order in CeRu2Al10

    SciTech Connect (OSTI)

    Kobayashi, Riki; Kaneko, Koji; Saito, Kotaro; Mignot, Jean-Michel; André, Gilles; Robert, Julien; Wakimoto, Shuichi; Matsuda, Masaaki; Chi, Songxue; Haga, Yoshinori; Matsuda, Tatsuma D.; Yamamoto, Etsuji; Nishioka, Takashi; Matsumura, Masahiro; Tanida, Hiroshi; Sera, Masafumi

    2014-09-17

    The effect of electron doping by the substitution of Rh for Ru on unconventional magnetic order in CeRu2Al10 was investigated via neutron powder diffraction. In Ce(Ru1-xRhx)2Al10 with x = 0.05, 0.12, and 0.2, reorientation of the ordered moment from the c- to the a-axis takes place in all samples, while the ordering vector q=(0 1 0) remains unchanged within this concentration range. The moment reorientation is accompanied by an enhancement in its size by a factor of ~2.4, from μ=0.43 μB at x=0 to μ =1.06, 1.04, and 1.02 μB for x=0.05, 0.12 and 0.2, respectively. The continuous decrease in N´eel temperature T0(TN), despite an abrupt increase in μ , underlines the strong anisotropy in the exchange interaction in CeRu2Al10, and the fact that this anisotropy is easily suppressed by electron doping.

  17. Strongly enhanced oxygen ion transport through samarium-doped CeO2 nanopillars in nanocomposite films

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

    Yang, Sangmo; Lee, Shinbuhm; Jian, Jie; Zhang, Wenrui; Lu, Ping; Jia, Quanxi; Wang, Haiyan; Noh, Tae Won; Kalinin, Sergei V.; MacManus-Driscoll, Judith L.

    2015-10-08

    Enhancement of oxygen ion conductivity in oxides is important for low-temperature (<500 °C) operation of solid oxide fuel cells, sensors and other ionotronic devices. While huge ion conductivity has been demonstrated in planar heterostructure films, there has been considerable debate over the origin of the conductivity enhancement, in part because of the difficulties of probing buried ion transport channels. Here we create a practical geometry for device miniaturization, consisting of highly crystalline micrometre-thick vertical nanocolumns of Sm-doped CeO2 embedded in supporting matrices of SrTiO3. The ionic conductivity is higher by one order of magnitude than plain Sm-doped CeO2 films. Bymore » using scanning probe microscopy, we show that the fast ion-conducting channels are not exclusively restricted to the interface but also are localized at the Sm-doped CeO2 nanopillars. This work offers a pathway to realize spatially localized fast ion transport in oxides of micrometre thickness.« less

  18. Strongly enhanced oxygen ion transport through samarium-doped CeO2 nanopillars in nanocomposite films

    SciTech Connect (OSTI)

    Yang, Sang Mo; Lee, Shinbuhm; Jian, Jie; Zhang, Wenrui; Lu, Ping; Jia, Quanxi; Wang, Haiyan; Won Noh, Tae; Kalinin, Sergei V.; MacManus?Driscoll, Judith L.

    2015-10-08

    Enhancement of oxygen ion conductivity in oxides is important for low-temperature (<500 C) operation of solid oxide fuel cells, sensors and other ionotronic devices. While huge ion conductivity has been demonstrated in planar heterostructure films, there has been considerable debate over the origin of the conductivity enhancement, in part because of the difficulties of probing buried ion transport channels. Here we create a practical geometry for device miniaturization, consisting of highly crystalline micrometre-thick vertical nanocolumns of Sm-doped CeO2 embedded in supporting matrices of SrTiO3. The ionic conductivity is higher by one order of magnitude than plain Sm-doped CeO2films. Then by using scanning probe microscopy, we show that the fast ion-conducting channels are not exclusively restricted to the interface but also are localized at the Sm-doped CeO2 nanopillars. Furthermore, this work offers a pathway to realize spatially localized fast ion transport in oxides of micrometre thickness.

  19. Remarkably robust and correlated coherence and antiferromagnetism in (Ce1-xLax)Cu2Ge2

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

    Hodovanets, H.; Bud’ko, S. L.; Straszheim, W. E.; Taufour, V.; Mun, E. D.; Kim, H.; Flint, R.; Canfield, P. C.

    2015-06-08

    We present magnetic susceptibility, resistivity, specific heat, and thermoelectric power measurements on (Ce1-xLax)Cu2Ge2 single crystals (0 ≤ x ≤ 1). With La-substitution, the antiferromagnetic temperature TN is suppressed in an almost linear fashion and moves below 0.36 K, the base temperature of our measurements for x > 0.8. Surprisingly, in addition to robust antiferromagnetism, the system also shows low temperature coherent scattering below Tcoh up to ~0.9 of La, indicating a small percolation limit ~9% of Ce. Tcoh as a function of magnetic field was found to have different behavior for x < 0.9 and x > 0.9. Remarkably, (Tcoh)2more » at H = 0 was found to be linearly proportional to TN. In conclusion, the jump in the magnetic specific heat δCm at TN as a function of TK/TN for (Ce1-xLax)Cu2Ge2 follows the theoretical prediction based on the molecular field calculation for the S = 1/2 resonant level model.« less

  20. Effect of Oxygen Defects on the Catalytic Performance of VOx/CeO2 Catalysts for Oxidative Dehydrogenation of Methanol

    SciTech Connect (OSTI)

    Li, Yan; Wei, Zhehao; Gao, Feng; Kovarik, Libor; Baylon, Rebecca A.; Peden, Charles HF; Wang, Yong

    2015-05-01

    In this work, CeO2 nanocubes with controlled particle size and dominating (100) facets are synthesized as supports for VOx catalysts. Combined TEM, SEM, XRD, and Raman study reveals that the oxygen vacancy density of CeO2 supports can be tuned by tailoring the particle sizes without altering the dominating facets, where smaller particle sizes result in larger oxygen vacancy densities. At the same vanadium coverage, the VOx catalysts supported on small-sized CeO2 supports with higher oxygen defect densities exhibit promoted redox property and lower activation energy for methoxyl group decomposition, as evidenced by H2-TPR and methanol TPD study. These results further confirm that the presence of oxygen vacancies plays an important role in promoting the activity of VOx species in methanol oxidation. We gratefully acknowledge financial support from the U.S. Department of Energy (DOE), Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. Part of this work was conducted in the William R. Wiley Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by DOE’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory (PNNL). PNNL is a multiprogram national laboratory operated for the DOE by Battelle.

  1. Dependence of waterflood remaining oil saturation on relative permeability, capillary pressure, and reservoir parameters in mixed-wet turbidite sands

    SciTech Connect (OSTI)

    Hirasaki, G.J.

    1996-05-01

    The dependence of waterflood oil recovery on relative permeability, capillary pressure, and reservoir parameters was investigated by numerical simulation. The relative permeability and capillary pressure curves were based on laboratory measurements on unconsolidated sands. The water-wet case is based on the assumption that the system is water-wet and measurements were made with refined oil. The mixed-wet case assumed that the system is mixed-wet and restored-state measurements were made with crude oil. The reservoir model was a prototype turbidite sand with a range of thickness and permeability values. The economic oil recovery was based on an economic limit water cut of 50%. The remaining oil saturation (ROS) in the swept region for the water-wet cases was close to the residual oil saturation. The ROS of the mixed-wet cases ranged from low values near the residual oil saturation to far above the residual oil saturation. It is dependent on the reservoir parameters that govern (1) the vertical film surface drainage of oil by gravity, (2) accumulation of a high oil saturation and thus a high relative permeability under the caprock, and (3) up-dip migration of the oil that accumulated under the caprock. The dependence on the reservoir parameters can be summarized by dimensionless groups. There is a dimensionless time for the vertical displacement of oil by gravity. The accumulation of a high oil saturation under the caprock is dependent on the ratio of the capillary transition zone and the sand thickness. The updip migration is dependent on a combination of the gravity number and the endpoint mobility ratio.

  2. Heavy crude and tar sands: Hydrocarbons for the 21st century. Volume 4, Upgrading, government and environment

    SciTech Connect (OSTI)

    Meyer, R.F.

    1991-12-31

    The 46 reports in Volume 4 begin with a section in the all-important subject of upgrading. Seventeen papers deals with upgrading of heavy oil and bitumen involving either of two basic processes, hydrogen addition or carbon rejection. Another five reports deal with the treatment of the oil in upgrading process through demetallization and by coprocessing with coal or lignite. The two papers on the Imulsion process present both the technology and the field experiences developed to transport and produce ORIMULSION{trademark}, the fuel developed with the bitumen from the Orinoco Belt. Seven papers in the section on environmental impacts are directed specifically to heavy oil. These deal mostly with the upgrading process, although one addresses the vexing problems of the refusal of extraction fines to settle out of tailings ponds in oil sand processing. A principal objective of the Centre is the fostering of technical cooperation between countries and the transfer of technological expertise in the area of heavy oil and natural bitumens from countries with advanced technology to those with undeveloped resources. The five reports in the section on Marketing and Economics carefully consider the demand in the context of world oil supply. Economic incentives is the stage for the final section of the volume, Government Policies and Legal Considerations. One of these reports presents an excellent review of the Venezuelan oil industry and its major efforts to promote the exploitation and utilization of heavy crude oil. Another of the reports describes ways in which the leasing procedures in Alberta may be modified to make the development of oil sands more effective. A third paper outlines procedures a company may usefully follow in order to most efficiently undertake the entire process of obtaining and developing oil sands leases. Individual papers have been processed separately for the database.

  3. Dust Plume Modeling from Ranges and Maneuver Areas on Fort Bliss and the White Sands Missile Range: Final Report

    SciTech Connect (OSTI)

    Chapman, Elaine G.; Barnard, James C.; Rutz, Frederick C.; Pekour, Mikhail S.; Rishel, Jeremy P.; Shaw, William J.

    2009-05-04

    The potential for air quality impacts from heavy mechanized vehicles operating on and between the unpaved main supply routes at Fort Bliss and White Sands Missile Range was investigated. This report details efforts by the staff of Pacific Northwest National Laboratory for the Fort Bliss Directorate of Environment in this investigation. Dust emission and dispersion from typical move-out activities occurring on the installations were simulated using the atmospheric modeling system DUSTRAN. Major assumptions associated with designing the modeling scenarios are summarized and results of simulations conducted under these assumptions are presented for four representative meteorological periods.

  4. SESAME 96170, a solid-liquid equation of state for CeO2

    SciTech Connect (OSTI)

    Chisolm, Eric D.

    2014-05-02

    I describe an equation of state (EOS) for the low-pressure solid phase and liquid phase of cerium (IV) oxide, CeO2. The models and parameters used to calculate the EOS are presented in detail, and I compare with data for the full-density crystal. Hugoniot data are available only for high-porosity powders, and I discuss difficulties in comparing with such data. I have constructed SESAME 96170, an EOS for cerium (IV) oxide that includes the ambient solid and liquid phases. The EOS extends over the full standard SESAME range, but should not be used at low temperatures and high densities because of the lack of a high-pressure solid phase. I have described the models used to compute the three terms of the EOS (cold curve, nuclear, and thermal electronic), and I have given the parameters used in the models. They were determined by comparison with experimental data at P = 1 atm, including the constant-pressure specific heat, coefficient of thermal expansion, and melting and boiling points. The EOS compares well with data in its intended range of validity, but the presence of high-frequency optical modes in its phonon spectrum limits the agreement of our models with thermal data. The next step is to construct a multiphase EOS that includes the low- and high-pressure solid phases and the liquid. The DAC data from Duclos will most strongly constrain the parameters of the high-pressure solid. A remaining issue is the comparison of the crystal-density EOS with experimental Hugoniot data, which are taken at much lower initial data because the samples are porous powders. A satisfactory means of modeling porosity, allowing comparison of theory and experiment, has not yet been produced.

  5. Methanol conversion to light olefins over nanostructured CeAPSO-34 catalyst: Thermodynamic analysis of overall reactions and effect of template type on catalytic properties and performance

    SciTech Connect (OSTI)

    Aghamohammadi, Sogand; Haghighi, Mohammad; Charghand, Mojtaba

    2014-02-01

    Graphical abstract: In this research nanostructured CeAPSO-34 was synthesized to explore the effect of TEAOH and morpholine on its physiochemical properties and MTO performance. Prepared catalysts were characterized with XRD, FESEM, BET, FTIR and NH3-TPD techniques. The results indicated that the nature of the template determines the physiochemical properties of CeAPSO-34 due to different rate of crystal growth. The catalyst obtained by using morpholine showed longer life time as well as sustaining light olefins selectivity at higher values. Furthermore, a comprehensive thermodynamic analysis of overall reactions network was carried out to address the major channels of methanol to olefins conversion. - Highlights: • Introduction of Ce into SAPO-34 framework. • Comparison of CeAPSO-34 synthesized using morpholine and TEAOH. • The nature of the template determines the physiochemical properties of CeAPSO-34. • Morpholine enhances catalyst lifetime in MTO process. • Presenting a complete reaction network for MTO process. - Abstract: TEAOH and morpholine were employed in synthesis of nanostructured CeAPSO-34 molecular sieve and used in methanol to olefins conversion. Prepared samples were characterized by XRD, FESEM, EDX, BET, FTIR and NH{sub 3}-TPD techniques. XRD patterns reflected the higher crystallinity of the catalyst synthesized with morpholine. The FESEM results indicated that the nature of the template determines the morphology of nanostructured CeAPSO-34 due to different rate of crystal growth. There was a meaningful difference in the strength of both strong and weak acid sites for CeAPSO-34 catalysts synthesized with TEAOH and morpholine templates. The catalyst synthesized with morpholine showed higher desorption temperature of both weak and strong acid sites evidenced by NH{sub 3}-TPD characterization. The catalyst obtained using morpholine template had the longer lifetime and sustained desired light olefins at higher values. A comprehensive

  6. Structural characterization of the CeO{sub 2}/Gd{sub 2}O{sub 3} mixed system by synchrotron X-ray diffraction

    SciTech Connect (OSTI)

    Artini, Cristina; Costa, Giorgio A.; Pani, Marcella; Lausi, Andrea; Plaisier, Jasper

    2012-06-15

    The structural determination of the CeO{sub 2}/Gd{sub 2}O{sub 3} mixed system is a non-trivial problem because of the close resemblance between the ionic sizes of Ce{sup 4+} and Gd{sup 3+} and between the crystal structures of CeO{sub 2} and Gd{sub 2}O{sub 3}. (Ce{sub 1-x}Gd{sub x})O{sub 2-x/2} powder samples with x ranging between 0 and 1 have been synthesized by coprecipitation of mixed oxalates and subsequent thermal decomposition in air at 1200 Degree-Sign C followed by slow cooling. Synchrotron powder X-ray diffraction data were collected and refined by the Rietveld method. Lattice parameters do not follow Vegard's law and no peak splitting has been observed for any composition, meaning that no biphasic regions exist over the whole compositional range. The same hybrid structural model - a proper mixture of the structures of the two pure oxides - was used for the refinements, allowing to account for the data observed. - graphical abstract: Substituting Ce{sup 4+} by Gd{sup 3+}, a gradual transition from the F structure (typical of CeO{sub 2}) to the C structure (typical of Gd{sub 2}O{sub 3}) takes place. The lattice parameters do not follow Vegard's law. Highlights: Black-Right-Pointing-Pointer A structural study of Ce-Gd mixed oxides has been performed. Black-Right-Pointing-Pointer In (Ce{sub 1-x}Gd{sub x})O{sub 2-x/2} a solid solution forms for 0{<=}x{<=}0.3. Black-Right-Pointing-Pointer For x>0.3 a gradual transition from the C to the F structure is observed. Black-Right-Pointing-Pointer Lattice parameters do not follow Vegard's law.

  7. A ferromagnetic quantum critical point in heavy-fermion iron oxypnictide CeFe{sub 1?x}Cr{sub x}PO

    SciTech Connect (OSTI)

    Okano, T.; Matoba, M.; Kamihara, Y.; Kitao, S.; Seto, M.; Atou, T.; Itoh, M.

    2015-05-07

    We report crystallographic and magnetic properties of layered iron oxypnictide CeFe{sub 1?x}Cr{sub x}PO (x?=?0.0000.692). Interlayer distances between Ce{sub 2}O{sub 2} and (Fe{sub 1?x}Cr{sub x}){sub 2}P{sub 2} layers increase as a function of x, suggesting suppression of Kondo coupling among hybridized conducting orbitals and localized Ce 4f orbitals. CeFe{sub 1?x}Cr{sub x}PO (x?=?0.1000.384) exhibits finite ferromagnetic transition temperatures (T{sub curie}) obtained by Arrott plots, although {sup 57}Fe Mssbauer spectra reveal paramagnetic Fe sublattice at T???4.2?K. These results indicate that the ferromagnetic phase transitions of samples are mainly due to Ce sublattice. For the samples with x???0.500, no ferromagnetic order is observed down to 2?K. These results verify that ferromagnetic quantum critical points of CeFe{sub 1?x}Cr{sub x}PO appear at 0.045???x???0.100 and 0.384???x???0.500.

  8. Superior performance of Ni–W–Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

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

    Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; Johnson-Peck, Aaron C.; Zhao, Fuzhen; Michorczyk, Piotr; Kubacka, Anna; Stach, Eric A.; Fernández-García, Marcos; Senanayake, Sanjaya D.; et al

    2014-11-26

    In this study, the ethanol steam reforming (ESR) reaction was examined over a series of Ni-W-Ce oxide catalysts. The structures of the catalysts were characterized using in-situ techniques including X-ray diffraction, Pair Distribution Function, X-ray absorption fine structure and transmission electron microscopy; while possible surface intermediates for the ESR reaction were investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy. In these materials, all the W and part of the Ni were incorporated into the CeO₂ lattice, with the remaining Ni forming highly dispersed nano NiO (< 2 nm) outside the Ni-W-Ce oxide structure. The nano NiO was reduced to Nimore » under ESR conditions. The Ni-W-Ce systeme exhibited a much larger lattice strain than those seen for Ni-Ce and W-Ce. Synergistic effects between Ni and W inside ceria produced a substantial amount of defects and O vacancies that led to high catalytic activity, selectivity and stability (i.e. resistance to coke formation) during ethanol steam reforming.« less

  9. Superior performance of Ni–W–Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

    SciTech Connect (OSTI)

    Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; Johnson-Peck, Aaron C.; Zhao, Fuzhen; Michorczyk, Piotr; Kubacka, Anna; Stach, Eric A.; Fernández-García, Marcos; Senanayake, Sanjaya D.; Rodriguez, José A.

    2014-11-26

    In this study, the ethanol steam reforming (ESR) reaction was examined over a series of Ni-W-Ce oxide catalysts. The structures of the catalysts were characterized using in-situ techniques including X-ray diffraction, Pair Distribution Function, X-ray absorption fine structure and transmission electron microscopy; while possible surface intermediates for the ESR reaction were investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy. In these materials, all the W and part of the Ni were incorporated into the CeO₂ lattice, with the remaining Ni forming highly dispersed nano NiO (< 2 nm) outside the Ni-W-Ce oxide structure. The nano NiO was reduced to Ni under ESR conditions. The Ni-W-Ce systeme exhibited a much larger lattice strain than those seen for Ni-Ce and W-Ce. Synergistic effects between Ni and W inside ceria produced a substantial amount of defects and O vacancies that led to high catalytic activity, selectivity and stability (i.e. resistance to coke formation) during ethanol steam reforming.

  10. Superior performance of Ni-W-Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

    SciTech Connect (OSTI)

    Rodriguez, Jose A.; Liu, Zongyuan; Xu, Wenqian; Yao, Siyu; Johnson-Peck, Aaron C.; Zhao, Fuzhen; Michorczyk, Piotr; Kubacka, Anna; Stach, Eric A.; Fernandez-Garica, Marcos; Senanayake, Sanjaya D.

    2014-11-26

    The ethanol steam reforming (ESR) reaction was studied over a series of Ni-W-Ce oxide catalysts. The structures of the catalysts were characterized using in-situ techniques including X-ray diffraction, Pair Distribution Function, X-ray absorption fine structure and transmission electron microscopy; while possible surface intermediates for the ESR reaction were investigated by Diffuse Reflectance Infrared Fourier Transform Spectroscopy. In these materials, all the W and part of the Ni were incorporated into the CeO? lattice, with the remaining Ni forming highly dispersed nano NiO (< 2 nm) outside the Ni-W-Ce oxide structure. The nano NiO was reduced to Ni under ESR conditions. The Ni-W-Ce systeme exhibited a much larger lattice strain than those seen for Ni-Ce and W-Ce. Synergistic effects between Ni and W inside ceria produced a substantial amount of defects and O vacancies that led to high catalytic activity, selectivity and stability (i.e. resistance to coke formation) during ethanol steam reforming.

  11. Crystalline Electric Field as a Probe for Long-Range Antiferromagnetic Order and Superconducting State of CeFeAsO1-xFx

    SciTech Connect (OSTI)

    Chi, Songxue; Adroja, D. T.; GUIDI, T.; Bewley, Robert I.; Li, Shiliang; Zhao, Jun; Lynn, J. W.; Brown, C. M.; Qiu, Y.; Chen, G. F,; Luo, J. L.; Wang, N. L.; Dai, Pengcheng

    2008-01-01

    We use inelastic neutron scattering to study the crystalline electric field (CEF) excitations of Ce{sup 3+} in CeFeAsO{sub 1-x}F{sub x} (x=0, 0.16). For nonsuperconducting CeFeAsO, the Ce CEF levels have three magnetic doublets in the paramagnetic state, but these doublets split into six singlets when the Fe ions order antiferromagnetically. For superconducting CeFeAsO{sub 0.84}F{sub 0.16} (T{sub c} = 41 K), where the static antiferromagnetic order is suppressed, the Ce CEF levels have three magnetic doublets at {h_bar}{sub {omega}} = 0, 18.7, 58.4 meV at all temperatures. Careful measurements of the intrinsic linewidth {Lambda} and the peak position of the 18.7 meV mode reveal a clear anomaly at T{sub c}, consistent with a strong enhancement of local magnetic susceptibility {chi}{double_prime}({h_bar}{sub {omega}}) below T{sub c}. These results suggest that CEF excitations in the rare-earth oxypnictides can be used as a probe of spin dynamics in the nearby FeAs planes.

  12. Advanced stimulation technology deployment program, Chevron USA Production Company, Wolfcamp A2 Sand, Pakenham Field, Val Verde Basin. Topical report, July 1995-March 1996

    SciTech Connect (OSTI)

    Wright, C.A.; Weijers, L.; Minner, W.A.

    1996-07-01

    This report describes the results from Chevron`s Pakenham Field effort at fracture stimulation engineering which incorporated, to the greatest extent possible, the results of actual measured field data. Measurement of the sand-shale closure stress contrast around the Wolfcamp A2 sand and the relatively high net fracturing pressures (compared to the closure stress contrast) that were observed during real-data (net pressure) fracture treatment analysis revealed that fractures obtained in most of the treatments were much shorter and less confined than originally expected: the fracture half-length was about 200 to 300 ft (instead of about 600 ft), which is consistent with estimates from post-fracture pressure build-up tests. Based on these measurements, Chevron`s fracturing practices in the Pakenham Field could be carefully reviewed to enhance fracture economics. Supported by the real-data fracture treatment analysis, several changes in completion, fracture treatment design and data-collection procedures were made, such as: (1) using cheaper 20/40 Ottawa sand instead of pre-cured 20/40 resin coated sand; (2) reducing the pad fluid size, as fluid leakoff from the fracture into the formation was relatively low; and, (3) utilizing stepdown tests and proppant slugs to minimize near-wellbore screen-out potential (in the Wolfcamp D sand).

  13. Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+}: A novel blue emitting phosphor for white LEDs

    SciTech Connect (OSTI)

    Li, Panlai Wang, Zhijun Yang, Zhiping; Guo, Qinglin

    2014-12-15

    Graphical abstract: Under the 350 nm radiation excitation, Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} has a broad blue emission band. When the temperature turned up to 150 C, the emission intensity of Ba{sub 1.97}B{sub 2}O{sub 5}:0.03Ce{sup 3+} is 63.4% of the initial value at room temperature. The activation energy ?E is calculated to be 0.25 eV, which prove the good thermal stability of Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+}. All the properties indicate that Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} may have potential application in white LEDs. - Highlights: Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} has a broad blue emission band under the 350 nm radiation excitation. Emission intensity of Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} is 63.4% (150 C) of the initial value (30 C). The activation energy ?E for thermal quenching is 0.25 eV. - Abstract: A novel blue emitting phosphor Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} is synthesized by a high temperature solid state method. The luminescent property and the thermal stability of Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} are investigated. Under the 350 nm radiation excitation, Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} has a broad blue emission band, and the peak locates at 417 nm which is assigned to the 5d{sup 1}4f{sup 1} transition of Ce{sup 3+}. It is further proved that the dipoledipole interaction results in the concentration quenching of Ce{sup 3+} in Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+}. When the temperature turned up to 150 C, the emission intensity of Ba{sub 1.97}B{sub 2}O{sub 5}:0.03Ce{sup 3+} is 63.4% of the initial value at room temperature. The activation energy ?E is calculated to be 0.25 eV, which prove the good thermal stability of Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+}. All the properties indicate that Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+} may have potential application in white LEDs.

  14. Hierarchical heterogeneity at the CeOx-TiO? interface: Electronic and geometric structural influence on the photocatalytic activity of oxide on oxide nanostructures

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

    None

    2015-01-13

    Mixed oxide interfaces are critical for delivering active components of demanding catalytic processes such as the photo-catalytic splitting of water. We have studied CeOxTiO? catalysts with low ceria loadings of 1 wt%, 3 wt% and 6 wt% that were prepared with wet impregnation methods to favor a strong interaction between CeOx and TiO?. In these materials the interfaces between CeOx-TiO? have been sequentially loaded (1%, 3% and 6%), with and without Pt (0.5 wt%). The structure and properties of the catalysts were characterized using several X-ray and electron based techniques including XRD, XPS, UPS, NEXAFS, UV-Vis and HR-STEM/STEM-EELS, to unravelmorethe local morphology, bulk structure, surface states and electronic structure. The combination of all these techniques allow us to analyze in a systematic way the complete structural and electronic properties that prevail at the CeOx-TiO? interface. Fluorite structured nano crystallites of ceria on anatase-structured titania were identified by both XRD and NEXAFS. A sequential increasing of the CeOx loading led to the formation of clusters, then plates and finally nano particles in a hierarchical manner on the TiO? support. The electronic structures of these catalysts indicate that the interaction between TiO? and CeO? is closely related to the local morphology of nanostructured CeO?. Ce? cations were detected at the surface of CeO? and at the interface of the two oxides. In addition, the titania is perturbed by the interaction with ceria and also with Pt. The photocatalytic activity for the splitting of H?O using UV light was measured for these materials and correlated with our understanding of the electronic and structural properties. Optimal catalytic performance and photo response results were found for the 1 wt% CeOx-TiO? catalyst where low dimensional geometry of the ceria provided ideal electronic and geometrical properties. The structural and electronic properties of the interface were critical for the

  15. Hierarchical Heterogeneity at the CeO x –TiO 2 Interface: Electronic and Geometric Structural Influence on the Photocatalytic Activity of Oxide on Oxide Nanostructures

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

    Luo, Si; Nguyen-Phan, Thuy-Duong; Johnston-Peck, Aaron C.; Barrio, Laura; Sallis, Shawn; Arena, Dario A.; Kundu, Shankhamala; Xu, Wenqian; Piper, Louis F. J.; Stach, Eric A.; et al

    2015-01-13

    Mixed oxide interfaces are critical for delivering active components of demanding catalytic processes such as the photo-catalytic splitting of water. We have studied CeOxTiO₂ catalysts with low ceria loadings of 1 wt%, 3 wt% and 6 wt% that were prepared with wet impregnation methods to favor a strong interaction between CeOx and TiO₂. In these materials the interfaces between CeOx-TiO₂ have been sequentially loaded (1%, 3% and 6%), with and without Pt (0.5 wt%). The structure and properties of the catalysts were characterized using several X-ray and electron based techniques including XRD, XPS, UPS, NEXAFS, UV-Vis and HR-STEM/STEM-EELS, to unravelmore » the local morphology, bulk structure, surface states and electronic structure. The combination of all these techniques allow us to analyze in a systematic way the complete structural and electronic properties that prevail at the CeOx-TiO₂ interface. Fluorite structured nano crystallites of ceria on anatase-structured titania were identified by both XRD and NEXAFS. A sequential increasing of the CeOx loading led to the formation of clusters, then plates and finally nano particles in a hierarchical manner on the TiO₂ support. The electronic structures of these catalysts indicate that the interaction between TiO₂ and CeO₂ is closely related to the local morphology of nanostructured CeO₂. Ce³⁺ cations were detected at the surface of CeO₂ and at the interface of the two oxides. In addition, the titania is perturbed by the interaction with ceria and also with Pt. The photocatalytic activity for the splitting of H₂O using UV light was measured for these materials and correlated with our understanding of the electronic and structural properties. Optimal catalytic performance and photo response results were found for the 1 wt% CeOx-TiO₂ catalyst where low dimensional geometry of the ceria provided ideal electronic and geometrical properties. The structural and electronic properties of the interface

  16. Chemistry of sands from the modern Indus River and the Archean Witwatersrand basin: Implications for the composition of the Archean atmosphere

    SciTech Connect (OSTI)

    Maynard, J.B.; Ritger, S.D. ); Sutton, S.J. )

    1991-03-01

    Both the Indus River and the Witwatersrand basin contain sand with grains of detrital uraninite. Because this mineral is easily oxidized, its presence in Archean strata as a detrital particle has been used as evidence for a low-oxygen atmosphere before 2.5 Ga. However, its presence in modern sand from the Indus River system has been used to argue that detrital uraninite does not provide information about the oxygen concentration of Earth's early atmosphere. Petrographic and chemical study of sand from these two sources reveals differences that suggest the modern Indus sand cannot be used as an analog for the Archean Witwatersrand occurrences. The Witwatersrand quartzites are depleted in Ca, Mg, and Na, indicating that the original sand from which they formed had been subjected to intense weathering. The chemical index of alteration (CIA), a commonly used indicator of degree of weathering, yields an average value of about 0.80 for Witwatersrand quartzites, comparable to modern tropical streams such as the Orinoco that drain deeply weathered terrains under tropical conditions (CIA=0.75). In contrast, the CIA for Indus sand is 0.45, indicating virtually no chemical weathering. The significance of Archean quartz-pebble conglomerates is not just that they contain unstable detrital phases like uraninite and pyrite, but that these particles are associated with rocks whose compositions suggest intense weathering. These conglomerates must have been subjected to intense weathering under tropical conditions, either in their source area or at the site of deposition, and the preservation of minerals like uraninite such conditions is indeed strong evidence for a low-oxygen atmosphere.

  17. Heavy fermion Ce{sub 3}Co{sub 4}Sn{sub 13} compound under pressure

    SciTech Connect (OSTI)

    Collave, J. R.; Borges, H. A.; Ramos, S. M.; Hering, E. N.; Mendona-Ferreira, L.; Pagliuso, P. G.

    2015-05-07

    The non-magnetic heavy fermion compound Ce{sub 3}Co{sub 4}Sn{sub 13} was studied under pressure. We report single crystalline measurements of electrical resistivity as a function of temperature ?(T) under pressure. Some characteristic features related to a structural transition (T{sub S}), crystalline field effects (T{sub CEF}), and a low temperature maximum (T{sub max}), possibly connected simultaneously to the onset of Kondo lattice coherence and short range magnetic correlations, were identified in the ?(T) data. A pressure-temperature phase diagram with T{sub S} and T{sub max} was constructed by mapping these features. Like for most Ce-based heavy fermion compounds, T{sub max} moves to higher temperatures with pressure, indicating that it is related to the Kondo energy scale, due to the increase of hybridization induced by pressure. On the other hand, T{sub S}, associated to a superlattice distortion and probably combined with a charge density wave transition, decreases as a function of pressure. However, differently from the Sr{sub 3?x}Ca{sub x}Ir{sub 4}Sn{sub 13} system, where a superlattice quantum phase transition is observed [L. E. Klintberg et al., Phys. Rev. Lett. 109, 237?008 (2012)], in Ce{sub 3}Co{sub 4}Sn{sub 13} T{sub S}???154?K, at ambient pressure (P?=?0), seems to stabilize at around 143?K for P???19 kilobars. We also investigated ?(T) in external magnetic fields, at P?=?0. Negative magnetoresistance and increase of T{sub max} are observed, suggesting suppression of low temperature short range magnetic correlations.

  18. Comparative Gamma Spectroscopy with SrI2(Eu), GYGAG(Ce) and Bi-loaded Plastic Scintillators

    SciTech Connect (OSTI)

    Cherepy, N J

    2010-11-19

    We are developing new scintillator materials that offer potential for high resolution gamma ray spectroscopy at low cost. Single crystal SrI{sub 2}(Eu) offers {approx}3% resolution at 662 keV, in sizes of {approx}1 in{sup 3}. We have developed ceramics processing technology allowing us to achieve cubic inch scale transparent ceramic scintillators offering gamma spectroscopy performance superior to NaI(Tl). We fabricated a bismuth-loaded plastic scintillator that demonstrates energy resolution of {approx}8% at 662 keV in small sizes. Gamma ray spectroscopy can be used to identify the presence of weak radioactive sources within natural background. The ability to discriminate close-lying spectral lines is strongly dependent upon the energy resolution of the detector. In addition to excellent energy resolution, large volume detectors are needed to acquire sufficient events, for example, to identify a radioactive anomaly moving past a detector. We have employed a 'directed search' methodology for identifying potential scintillator materials candidates, resulting in the discovery of Europium-doped Strontium Iodide, SrI{sub 2}(Eu), Cerium-doped Gadolinium Garnet, GYGAG(Ce), and Bismuth-loaded Polymers. These scintillators possess very low self-radioactivity, offer energy resolution of 3-8% at 662 keV, and have potential to be grown cost-effectively to sizes similar to the most widely deployed gamma spectroscopy scintillator, Thallium-doped Sodium Iodide, NaI(Tl). In this study, gamma ray spectra of a variety of sources, were obtained employing SrI{sub 2}(Eu), GYGAG(Ce), Bi-loaded polymers, LaBr{sub 3}(Ce), and NaI(Tl). The effects of detector size, energy resolution, and background radioactivity (including self-radioactivity) on the ability to distinguish weak sources is quantified, based on a simple model, and qualitatively compared to laboratory data.

  19. Fabrication and microstructure of cerium doped lutetium aluminum garnet (Ce:LuAG) transparent ceramics by solid-state reaction method

    SciTech Connect (OSTI)

    Li, Junlang; Xu, Jian; Shi, Ying; Qi, Hongfang; Xie, Jianjun; Lei, Fang

    2014-07-01

    Highlights: We fabricate Ce doped lutetium aluminum garnet ceramics by solid-state method. The raw materials include Lu{sub 2}O{sub 3} nanopowders synthesized by co-precipitation method. The density of the transparent ceramics reach 99.7% of the theoretical value. The optical transmittance of the bulk ceramic at 550 nm was 57.48%. Some scattering centers decrease the optical characteristic of the ceramic. - Abstract: Polycrystalline Ce{sup 3+} doped lutetium aluminum garnet (Ce:LuAG) transparent ceramics fabricated by one step solid-state reaction method using synthetic nano-sized Lu{sub 2}O{sub 3}, commercial ?-Al{sub 2}O{sub 3} and CeO{sub 2} powders were investigated in this paper. The green compacts shaped by the mixed powders were successfully densified into Ce:LuAG transparent ceramics after vacuum sintering at 1750 C for 10 h. The in-line optical transmittance of the Ce:LuAG ceramic made by home-made Lu{sub 2}O{sub 3} powders could reach 57.48% at 550 nm, which was higher than that of the ceramic made by commercial Lu{sub 2}O{sub 3} powders (22.96%). The microstructure observation showed that light scattering centers caused by micro-pores, aluminum segregation and refraction index inhomogeneities induced the decrease of optical transparency of the Ce:LuAG ceramics, which should be removed and optimized in the future work.

  20. Synthesis of mesoporous Bi{sub 2}O{sub 3}/CeO{sub 2} microsphere for photocatalytic degradation of Orange II dye

    SciTech Connect (OSTI)

    Hsieh, Shu-Han; Manivel, Arumugam; Lee, Gang-Juan; Wu, Jerry J.

    2013-10-15

    Graphical abstract: - Highlights: • Bi{sub 2}O{sub 3}/CeO{sub 2} microspheres were successfully synthesized by a hydrothermal procedure. • Bi{sub 2}O{sub 3}/CeO{sub 2} microspheres were used to remove wastewater pollutant containing azo dye. • The activity of Bi{sub 2}O{sub 3}/CeO{sub 2} is synergically enhanced compared to its pristine forms. - Abstract: We report on the visible-light responsive porous assembly of Bi{sub 2}O{sub 3}/CeO{sub 2} microspheres, which were synthesized via a simple hydrothermal reaction between Bi(NO{sub 3}){sub 3}·5H{sub 2}O and Ce(NO{sub 3}){sub 3}·6H{sub 2}O in the presence of ethylene glycol and ethanol. Systematic structural (X-ray diffraction (XRD)), morphological (field emission scanning electron microscopy (FE-SEM) and transmission electron microscopic (TEM)), BET surface area and diffuse reflectance spectral (DRS) analyses were carried out to characterize the formed product. The effects of experimental parameters on the microstructural and morphological behavior of Bi{sub 2}O{sub 3}/CeO{sub 2} composites were discussed. The semiconductor material as obtained was evaluated as a heterogeneous photocatalyst for the photolytic degradation of an azo dye in water and the degradation was found to follow pseudo-first-order rate kinetics. The study compares the rate constants of the new hybrid catalyst to a pristine Bi{sub 2}O{sub 3} and CeO{sub 2}, which has excellent catalytic properties under visible light irradiation for the degradation of Orange II dye.

  1. Response of LaBr{sub 3}(Ce) scintillators to 2.5 MeV fusion neutrons

    SciTech Connect (OSTI)

    Cazzaniga, C.; Nocente, M.; Gorini, G.; Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, Via Roberto Cozzi 53, Milano 20125 ; Tardocchi, M.; Croci, G.; Giacomelli, L.; Angelone, M.; Pillon, M.; Villari, S.; Weller, A.; Petrizzi, L.; Collaboration: ASDEX Upgrade Team; JET-EFDA Contributors

    2013-12-15

    Measurements of the response of LaBr{sub 3}(Ce) to 2.5 MeV neutrons have been carried out at the Frascati Neutron Generator and at tokamak facilities with deuterium plasmas. The observed spectrum has been interpreted by means of a Monte Carlo model. It is found that the main contributor to the measured response is neutron inelastic scattering on {sup 79}Br, {sup 81}Br, and {sup 139}La. An extrapolation of the count rate response to 14 MeV neutrons from deuterium-tritium plasmas is also presented. The results are of relevance for the design of ?-ray diagnostics of fusion burning plasmas.

  2. Effect of magnetic fields on the Kondo insulator CeRhSb: Magnetoresistance and high-field heat capacity measurements

    SciTech Connect (OSTI)

    Malik, S.K.; Menon, L.; Pecharsky, V.K.; Gschneidner, K.A. Jr.

    1997-05-01

    The compound CeRhSb is a mixed valent Ce-based compound which shows a gap in the electronic density of states at low temperatures. The gap manifests by a rise in electrical resistivity{emdash}below about 8 K from which the gap energy is estimated to be about 4 K. We have carried out heat capacity measurements on this compound in various applied fields up to 9.85 T. The magnetic contribution to the heat capacity, {Delta}C, is found to have a maximum in {Delta}C/T vs T at 10 K, below which {Delta}C/T is linear with T. This is attributed to the fact that below this temperature, in the gapped state, the electronic density of states decreases linearly with decreasing temperature. On application of a magnetic field, the electronic specific heat coefficient {gamma} in the gapped state increases by {approximately}4mJ/molK{sup 2}. The maximum in {Delta}C/T vs T is observed in all fields, which shifts to lower temperatures {approximately}1K at 5.32 T and raises again at 9.85 T to about the same values as at H=0T. This suggests that the gap exists for all fields up to 9.85 T. Above 10 K, in the mixed-valent state, {Delta}C/T vs T decreases with increasing temperature in zero field. There is hardly any effect of application of field in the mixed-valent state. We have also carried out magnetoresistance measurements on CeRhSb up to fields of 5.5 T at 2, 4.5, 10, 20, and 30 K. The magnetoresistance in CeRhSb is positive at temperatures of 4.5 K and above, in applied fields up to 5.5 T. At 5.5 T, the magnetoresistance is maximum at 4.5 K (6{percent}) and decreases with increasing temperature. The observation of the maximum is consistent with the observation of a maximum in {Delta}C/T vs T and is due to a change in the density of states. At a temperature of 2 K, a negative magnetoresistance is observed for magnetic fields greater than {approximately}3.5T which suggests reduction in the gap. {copyright} {ital 1997} {ital The American Physical Society}

  3. Generation and reactivity of putative support systems, Ce-Al neutral binary oxide nanoclusters: CO oxidation and CH bond activation

    SciTech Connect (OSTI)

    Wang, Zhe-Chen; Yin, Shi; Bernstein, Elliot R.

    2013-11-21

    Both ceria (CeO{sub 2}) and alumina (Al{sub 2}O{sub 3}) are very important catalyst support materials. Neutral binary oxide nanoclusters (NBONCs), Ce{sub x}Al{sub y}O{sub z}, are generated and detected in the gas phase and their reactivity with carbon monoxide (CO) and butane (C{sub 4}H{sub 10}) is studied. The very active species CeAlO{sub 4}{sup } can react with CO and butane via O atom transfer (OAT) and H atom transfer (HAT), respectively. Other Ce{sub x}Al{sub y}O{sub z} NBONCs do not show reactivities toward CO and C{sub 4}H{sub 10}. The structures, as well as the reactivities, of Ce{sub x}Al{sub y}O{sub z} NBONCs are studied theoretically employing density functional theory (DFT) calculations. The ground state CeAlO{sub 4}{sup } NBONC possesses a kite-shaped structure with an O{sub t}CeO{sub b}O{sub b}AlO{sub t} configuration (O{sub t}, terminal oxygen; O{sub b}, bridging oxygen). An unpaired electron is localized on the O{sub t} atom of the AlO{sub t} moiety rather than the CeO{sub t} moiety: this O{sub t} centered radical moiety plays a very important role for the reactivity of the CeAlO{sub 4}{sup } NBONC. The reactivities of Ce{sub 2}O{sub 4}, CeAlO{sub 4}{sup }, and Al{sub 2}O{sub 4} toward CO are compared, emphasizing the importance of a spin-localized terminal oxygen for these reactions. Intramolecular charge distributions do not appear to play a role in the reactivities of these neutral clusters, but could be important for charged isoelectronic BONCs. DFT studies show that the reaction of CeAlO{sub 4}{sup } with C{sub 4}H{sub 10} to form the CeAlO{sub 4}HC{sub 4}H{sub 9}{sup } encounter complex is barrierless. While HAT processes have been previously characterized for cationic and anionic oxide clusters, the reported study is the first observation of a HAT process supported by a ground state neutral oxide cluster. Mechanisms for catalytic oxidation of CO over surfaces of Al{sub x}O{sub y}/M{sub m}O{sub n} or M{sub m}O{sub n}/Al{sub x}O{sub y

  4. Antiferromagnetic Kondo lattice in the layered compound CePd1–xBi₂ and comparison to the superconductor LaPd1–xBi₂

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

    Han, Fei; Wan, Xiangang; Phelan, Daniel; Stoumpos, Constantinos C.; Sturza, Mihai; Malliakas, Christos D.; Li, Qing'an; Han, Tian-Heng; Zhao, Qingbiao; Chung, Duck Young; et al

    2015-07-13

    The layered compound CePd1–xBi₂ with the tetragonal ZrCuSi₂-type structure was obtained from excess Bi flux. Magnetic susceptibility data of CePd1–xBi₂ show an antiferromagnetic ordering below 6 K and are anisotropic along the c axis and the ab plane. The anisotropy is attributed to crystal-electric-field (CEF) effects and a CEF model which is able to describe the susceptibility data is given. An enhanced Sommerfeld coefficient γ of 0.191 J mol Ce⁻¹ K⁻² obtained from specific-heat measurement suggests a moderate Kondo effect in CePd1–xBi₂. Other than the antiferromagnetic peak at 6 K, the resistivity curve shows a shoulderlike behavior around 75 Kmore » which could be attributed to the interplay between Kondo and CEF effects. Magnetoresistance and Hall-effect measurements suggest that the interplay reconstructs the Fermi-surface topology of CePd1–xBi₂ around 75 K. Electronic structure calculations reveal that the Pd vacancies are important to the magnetic structure and enhance the CEF effects which quench the orbital moment of Ce at low temperatures.« less

  5. Electronic and optical properties of layered RE{sub 2}Ti{sub 2}O{sub 7} (RE = Ce and Pr) from first principles

    SciTech Connect (OSTI)

    Sayede, A.; Khenata, R.; Chahed, A.; Benhelal, O.

    2013-05-07

    We have studied the structural and electronic properties of Ce{sub 2}Ti{sub 2}O{sub 7} (CeTO) and Pr{sub 2}Ti{sub 2}O{sub 7} (PrTO) by first-principles density functional theory calculations. The computed structural parameters are in fairly good agreement with the available experimental findings. Band structure calculations using the GGA+U approach predict an insulating ground state for the herein studied compounds. The insulating band gaps of 2.00 eV and 2.83 eV are found for CeTO and PrTO, respectively. The analysis of the density of states reveals that the strongly localized RE 4f levels act as charge-trapping sites, predicting a lower photocatalytic activity for CeTO. We have also calculated the optical properties for both CeTO and PrTO. Based on these properties, it is predicted that these titanates are insensitive to ultra-violet radiation, while they are more sensitive to frequencies of the radiation in visible and early UV regions.

  6. Weak hybridization and isolated localized magnetic moments in the compounds CeT2Cd20 (T = Ni, Pd)

    SciTech Connect (OSTI)

    White, B. D.; Yazici, D.; Ho, P. -C.; Kanchanavatee, N.; Pouse, N.; Fang, Y.; Breindel, A. J.; Friedman, A. J.; Maple, M. B.

    2015-07-20

    Here, we report the physical properties of single crystals of the compounds CeT2Cd20 (T = Ni, Pd) that were grown in a molten Cd flux. Large separations of ~6.7- 6.8 Å between Ce ions favor the localized magnetic moments that are observed in measurements of the magnetization. The strength of the Ruderman-Kittel-Kasuya- Yosida magnetic exchange interaction between the localized moments is severely limited by the large Ce-Ce separations and by weak hybridization between localized Ce 4f and itinerant electron states. Measurements of electrical resistivity performed down to 0.138 K were unable to observe evidence for the emergence of magnetic order; however, magnetically-ordered ground states with very low transition temperatures are still expected in these compounds despite the isolated nature of the localized magnetic moments. Such a fragile magnetic order could be highly susceptible to tuning via applied pressure, but evidence for the emergence of magnetic order has not been observed so far in our measurements up to 2.5 GPa.

  7. Universal heat conduction in Ce1-xYbxCoIn5: Evidence for robust nodal d-wave superconducting gap

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

    Xu, Y.; Petrovic, C.; Dong, J. K.; Lum, I. K.; Zhang, J.; Hong, X. C.; He, L. P.; Wang, K. F.; Ma, Y. C.; Maple, M. B.; et al

    2016-02-01

    In the heavy-fermion superconductor Ce1-xYbxCoIn5, Yb doping was reported to cause a possible change from nodal d-wave superconductivity to a fully gapped d-wave molecular superfluid of composite pairs near x ≈ 0.07 (nominal value xnom = 0.2). Here we present systematic thermal conductivity measurements on Ce1-xYbxCoIn5 (x = 0.013, 0.084, and 0.163) single crystals. The observed finite residual linear term κ0/T is insensitive to Yb doping, verifying the universal heat conduction of the nodal d-wave superconducting gap in Ce1-xYbxCoIn5. Similar universal heat conduction is also observed in the CeCo(In1–yCdy)5 system. Furthermore, these results reveal a robust nodal d-wave gap inmore » CeCoIn5 upon Yb or Cd doping.« less

  8. Effect of Doping on Surface Reactivity and Conduction Mechanism in Sm-doped CeO2 Thin Films

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

    Yang, Nan; Belianinov, Alex; Strelcov, Evgheni; Tebano, Antonello; Daniele, Di Castro; Schlueter, Christoph; Lee, Tien-Lin; Baddorf, Arthur P.; Wisinger, Nina; Jesse, Stephen; et al

    2014-11-21

    Scanning probe microscopy measurements show irreversible surface electrochemistry in Sm-doped CeO2 thin films, which depends on humidity, temperature and doping concentration. A systematic study by electrochemical strain microscopy (ESM) in samples with two different Sm content and in several working conditions allows disclosing the microscopic mechanism underlying the difference in water adsorption and splitting with subsequent proton liberation. We measure the behavior of the hysteresis loops by changing temperature and humidity, both in standard ESM configuration and using the first order reversal curve (FORC) method. Complementing our study with spectroscopic measurements by hard x-ray photoemission spectroscopy we find that watermore » incorporation is favored until the doping with Sm is too high to allow the presence of Ce3+. The influence of doping on the surface reactivity and conduction mechanism clearly emerges from all of our experimental results. We find that at lower Sm concentration proton conduction is prevalent, featured by lower activation energy and higher mobility. Defect concentrations determine the type of the prevalent charge carrier in a doping dependent manner.« less

  9. Rapid Microwave Preparation of Highly Efficient Ce[superscript 3+]-Substituted Garnet Phosphors for Solid State White Lighting

    SciTech Connect (OSTI)

    Birkel, Alexander; Denault, Kristin A.; George, Nathan C.; Doll, Courtney E.; Hry, Bathylle; Mikhailovsky, Alexander A.; Birkel, Christina S.; Hong, Byung-Chul; Seshadri, Ram (UCSB); (Mitsubishi)

    2012-04-30

    Ce{sup 3+}-substituted aluminum garnet compounds of yttrium (Y{sub 3}Al{sub 5}O{sub 12}) and lutetium (Lu{sub 3}Al{sub 5}O{sub 12}) - both important compounds in the generation of (In,Ga)N-based solid state white lighting - have been prepared using a simple microwave heating technique involving the use of a microwave susceptor to provide the initial heat source. Carbon used as the susceptor additionally creates a reducing atmosphere around the sample that helps stabilize the desired luminescent compound. High quality, phase-pure materials are prepared within a fraction of the time and using a fraction of the energy required in a conventional ceramic preparation; the microwave technique allows for a reduction of about 95% in preparation time, making it possible to obtain phase pure, Ce{sup 3+}-substituted garnet compounds in under 20 min of reaction time. It is estimated that the overall reduction in energy compared with ceramic routes as practiced in the lab is close to 99%. Conventionally prepared material is compared with material prepared using microwave heating in terms of structure, morphology, and optical properties, including quantum yield and thermal quenching of luminescence. Finally, the microwave-prepared compounds have been incorporated into light-emitting diode 'caps' to test their performance characteristics in a real device, in terms of their photon efficiency and color coordinates.

  10. Pressure-tuned quantum criticality in the antiferromagnetic Kondo semimetal CeNi2–δAs2

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

    Luo, Yongkang; Ronning, F.; Wakeham, N.; Lu, Xin; Park, Tuson; Xu, Z. -A.; Thompson, J. D.

    2015-10-19

    The easily tuned balance among competing interactions in Kondo-lattice metals allows access to a zero-temperature, continuous transition between magnetically ordered and disordered phases, a quantum-critical point (QCP). Indeed, these highly correlated electron materials are prototypes for discovering and exploring quantum-critical states. Theoretical models proposed to account for the strange thermodynamic and electrical transport properties that emerge around the QCP of a Kondo lattice assume the presence of an indefinitely large number of itinerant charge carriers. Here, we report a systematic transport and thermodynamic investigation of the Kondo-lattice system CeNi2–δAs2 (δ ≈ 0.28) as its antiferromagnetic order is tuned by pressuremore » and magnetic field to zero-temperature boundaries. These experiments show that the very small but finite carrier density of ~0.032 e–/formular unit in CeNi2–δAs2 leads to unexpected transport signatures of quantum criticality and the delayed development of a fully coherent Kondo-lattice state with decreasing temperature. Here, the small carrier density and associated semimetallicity of this Kondo-lattice material favor an unconventional, local-moment type of quantum criticality and raises the specter of the Nozières exhaustion idea that an insufficient number of conduction-electron spins to separately screen local moments requires collective Kondo screening.« less

  11. Use of Computed X-ray Tomographic Data for Analyzing the Thermodynamics of a Dissociating Porous Sand/Hydrate Mixture

    DOE R&D Accomplishments [OSTI]

    Freifeld, Barry M.; Kneafsey, Timothy J.; Tomutsa, Liviu; Stern, Laura A.; Kirby, Stephen H.

    2002-02-28

    X-ray computed tomography (CT) is a method that has been used extensively in laboratory experiments for measuring rock properties and fluid transport behavior. More recently, CT scanning has been applied successfully to detect the presence and study the behavior of naturally occurring hydrates. In this study, we used a modified medical CT scanner to image and analyze the progression of a dissociation front in a synthetic methane hydrate/sand mixture. The sample was initially scanned under conditions at which the hydrate is stable (atmospheric pressure and liquid nitrogen temperature, 77 K). The end of the sample holder was then exposed to the ambient air, and the core was continuously scanned as dissociation occurred in response to the rising temperature. CT imaging captured the advancing dissociation front clearly and accurately. The evolved gas volume was monitored as a function of time. Measured by CT, the advancing hydrate dissociation front was modeled as a thermal conduction problem explicitly incorporating the enthalpy of dissociation, using the Stefan moving-boundary-value approach. The assumptions needed to perform the analysis consisted of temperatures at the model boundaries. The estimated value for thermal conductivity of 2.6 W/m K for the remaining water ice/sand mixture is higher than expected based on conduction alone; this high value may represent a lumped parameter that incorporates the processes of heat conduction, methane gas convection, and any kinetic effects that occur during dissociation. The technique presented here has broad implications for future laboratory and field testing that incorporates geophysical techniques to monitor gas hydrate dissociation.

  12. An NMR (Nuclear Magnetic Resonance) Investigation of the Chemical Association and Molecular Dynamics in Asphalt Ridge Tar Sand Ore and Bitumen

    DOE R&D Accomplishments [OSTI]

    Netzel, D. A.; Coover, P. T.

    1987-09-01

    Preliminary studies on tar sand bitumen given in this report have shown that the reassociation of tar sand bitumen to its original molecular configuration after thermal stressing is a first-order process requiring nearly a week to establish equilibrium. Studies were also conducted on the dissolution of tar sand bitumen in solvents of varying polarity. At a high-weight fraction of solute to solvent the apparent molecular weight of the bitumen molecules was greater than that of the original bitumen when dissolved in chloroform-d{sub 1} and benzene-d{sub 6}. This increase in the apparent molecular weight may be due to micellar formation or a weak solute-solvent molecular complex. Upon further dilution with any of the solvents studied, the apparent molecular weight of the tar sand bitumen decreased because of reduced van der Waals forces of interaction and/or hydrogen bonding. To define the exact nature of the interactions, it will be necessary to have viscosity measurements of the solutions.

  13. Chemical Reduction of Nd1.85Ce0.15CuO4??Powders in Supercritical Sodium Ammonia Solutions

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

    Dias, Yasmin; Wang, Hui; Zhou, Haiqing; Lin, Feng; Lan, Yucheng

    2015-01-01

    Nd1.85Ce0.15CuO4??powders are chemically reduced in supercritical sodium ammonia solutions from room temperature to 350C. The crystallographic structure of the reduced powders is investigated from Rietveld refinement of X-ray powder diffraction. The atomic positions are maintained constant within experimental errors while temperature factors of all atoms increase significantly after the chemical treatments, especially of Nd/Ce atoms. The ammonothermally reduced Nd1.85Ce0.15CuO4??powders show diamagnetic below 24?K which is contributed to the lower oxygen content and higher temperature factors of atoms in the treated compound. The ammonothermal method paves a new way to reduce oxides in supercritical solutions near room temperature.

  14. Pressure-Induced Structural Phase Transition in CeNi: X-ray and Neutron Scattering Studies and First-Principles Calculations

    SciTech Connect (OSTI)

    Mirmelstein, A.; Podlesnyak, Andrey A.; dos Santos, Antonio M.; Ehlers, Georg; Kerbel, O.; Matvienko, V.; Sefat, A. S.; Saporov, B.; Halder, G. J.; Tobin, J. G.

    2015-08-03

    The pressure-induced structural phase transition in the intermediate-valence compound CeNi has been investigated by x-ray and neutron powder diffraction techniques. It is shown that the structure of the pressure-induced CeNi phase (phases) can be described in terms of the Pnma space group. Equations of state for CeNi on both sides of the phase transition are derived and an approximate P-T phase diagram is suggested for P<8 GPa and T<300 K. The observed Cmcm→Pnma structural transition is then analyzed using density functional theory calculations, which successfully reproduce the ground state volume, the phase transition pressure, and the volume collapse associated with the phase transition.

  15. Pressure-Induced Structural Phase Transition in CeNi: X-ray and Neutron Scattering Studies and First-Principles Calculations

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

    Mirmelstein, A.; Podlesnyak, Andrey A.; dos Santos, Antonio M.; Ehlers, Georg; Kerbel, O.; Matvienko, V.; Sefat, A. S.; Saporov, B.; Halder, G. J.; Tobin, J. G.

    2015-08-03

    The pressure-induced structural phase transition in the intermediate-valence compound CeNi has been investigated by x-ray and neutron powder diffraction techniques. It is shown that the structure of the pressure-induced CeNi phase (phases) can be described in terms of the Pnma space group. Equations of state for CeNi on both sides of the phase transition are derived and an approximate P-T phase diagram is suggested for P<8 GPa and T<300 K. The observed Cmcm→Pnma structural transition is then analyzed using density functional theory calculations, which successfully reproduce the ground state volume, the phase transition pressure, and the volume collapse associated withmore » the phase transition.« less

  16. Chemical Reduction of Nd 1.85 Ce 0.15 CuO 4− δ Powders in Supercritical Sodium Ammonia Solutions

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

    Dias, Yasmin; Wang, Hui; Zhou, Haiqing; Lin, Feng; Lan, Yucheng

    2015-01-01

    Nd 1.85 Ce 0.15 CuO 4− δ powders are chemically reduced in supercritical sodium ammonia solutions from room temperature to 350°C. The crystallographic structure of the reduced powders is investigated from Rietveld refinement of X-ray powder diffraction. The atomic positions are maintained constant within experimental errors while temperature factors of all atoms increase significantly after the chemical treatments, especially of Nd/Ce atoms. The ammonothermally reduced Nd 1.85 Ce 0.15 CuO 4− δ powders show diamagnetic below 24 K which is contributed to the lower oxygen content and higher temperature factors of atoms in the treated compound.more » The ammonothermal method paves a new way to reduce oxides in supercritical solutions near room temperature.« less

  17. Magnetic hardening of Ce1+xFe11–yCoyTi with ThMn12 structure by melt spinning

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

    Zhou, Chen; Sun, Kewei; Pinkerton, Frederick E.; Kramer, M. J.

    2015-04-15

    A recent study on the intrinsic magnetic properties of CeFe11–yCoyTi has revealed that substituting one Co for Fe retains the favorable magnetocrystalline anisotropy Ha found in the ternary Fe end member, while enhancing the Curie temperature Tc and saturation magnetization 4πMs. These findings warrant further optimization around Co substitution y = 1 to try to exploit the hard magnetic properties of these Ce-based magnets. Both Ce and Co concentrations in Ce1+xFe11–yCoyTi have been optimized in the range of x = 0 – 0.2 and y = 0 –1.5. It was found that Co substitution effectively enhances all hard magnetic properties,more »although the values are still lower than those predicted from the intrinsic magnetic properties. Specifically, Tc increases from 210 °C to 285 – 350 °C; 4πM19 (magnetization at 19 kOe) from 8.9 kG to 10.5 – 11.5 kG, remanence Br from 3.1 kG to 4.1 – 4.5 kG, and most importantly, Hci from 1.1 kOe to 1.5 kOe. As a result, the room temperature energy product (BH)max has been increased by over 100% from 0.7 MGOe in Ce1.1Fe11Ti to 1.5 MGOe in Ce1.05Fe9.75Co1.25Ti. Microscopy analysis indicates that the addition of Co refines the grain size and promotes chemical homogeneity at the microscopic scale. As a result, the beneficial effect of Co on the microstructure contributes to the improved hard magnetic properties.« less

  18. Magnetic hardening of Ce1+xFe11–yCoyTi with ThMn12 structure by melt spinning

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

    Zhou, Chen; Sun, Kewei; Pinkerton, Frederick E.; Kramer, M. J.

    2015-04-15

    A recent study on the intrinsic magnetic properties of CeFe11–yCoyTi has revealed that substituting one Co for Fe retains the favorable magnetocrystalline anisotropy Ha found in the ternary Fe end member, while enhancing the Curie temperature Tc and saturation magnetization 4πMs. These findings warrant further optimization around Co substitution y = 1 to try to exploit the hard magnetic properties of these Ce-based magnets. Both Ce and Co concentrations in Ce1+xFe11–yCoyTi have been optimized in the range of x = 0 – 0.2 and y = 0 –1.5. It was found that Co substitution effectively enhances all hard magnetic properties,more » although the values are still lower than those predicted from the intrinsic magnetic properties. Specifically, Tc increases from 210 °C to 285 – 350 °C; 4πM19 (magnetization at 19 kOe) from 8.9 kG to 10.5 – 11.5 kG, remanence Br from 3.1 kG to 4.1 – 4.5 kG, and most importantly, Hci from 1.1 kOe to 1.5 kOe. As a result, the room temperature energy product (BH)max has been increased by over 100% from 0.7 MGOe in Ce1.1Fe11Ti to 1.5 MGOe in Ce1.05Fe9.75Co1.25Ti. Microscopy analysis indicates that the addition of Co refines the grain size and promotes chemical homogeneity at the microscopic scale. As a result, the beneficial effect of Co on the microstructure contributes to the improved hard magnetic properties.« less

  19. Reactivity of pulverized coals during combustion catalyzed by CeO{sub 2} and Fe{sub 2}O{sub 3}

    SciTech Connect (OSTI)

    Gong, Xuzhong; Guo, Zhancheng; Wang, Zhi

    2010-02-15

    Effects of CeO{sub 2} and Fe{sub 2}O{sub 3} on combustion reactivity of several fuels, including three ranks of coals, graphite and anthracite chars, were investigated using thermo-gravimetric analyzer. The results indicated that the combustion reactivity of all the samples except lignite was improved with CeO{sub 2} or Fe{sub 2}O{sub 3} addition. It was interesting to note that the ignition temperatures of anthracite were decreased by 50 C and 53 C, respectively, with CeO{sub 2} and Fe{sub 2}O{sub 3} addition and that its combustion rates were increased to 15.4%/min and 12.2%/min. Ignition temperatures of lignite with CeO{sub 2} and Fe{sub 2}O{sub 3} addition were 250 C and 226 C, and the combustion rates were 12.8% and 19.3%/min, respectively. When compared with those of lignite without catalysts, no obvious catalytic effects of the two catalysts on its combustion reactivity were revealed. The results from the combustion of the three rank pulverized coals catalyzed by CeO{sub 2} and Fe{sub 2}O{sub 3} indicated significant effects of the two catalysts on fixed carbon combustion. And it was found that the higher the fuel rank, the better the catalytic effect. The results of combustion from two kinds of anthracite chars showed obvious effects of anthracite pyrolysis catalyzed by CeO{sub 2} and Fe{sub 2}O{sub 3} on its combustion reactivity. (author)

  20. Lu.sub.1-xI.sub.3:Ce.sub.x-a scintillator for gamma-ray spectroscopy and time-of-flight pet

    DOE Patents [OSTI]

    Shah, Kanai S.

    2008-02-12

    The present invention includes very fast scintillator materials including lutetium iodide doped with Cerium (Lu.sub.1-xI.sub.3:Ce.sub.x; LuI.sub.3:Ce). The LuI.sub.3 scintillator material has surprisingly good characteristics including high light output, high gamma-ray stopping efficiency, fast response, low cost, good proportionality, and minimal afterglow that the material is useful for gamma-ray spectroscopy, medical imaging, nuclear and high energy physics research, diffraction, non-destructive testing, nuclear treaty verification and safeguards, and geological exploration.

  1. Magnetic properties of CeFe11-xCoxTi with ThMn12 structure

    SciTech Connect (OSTI)

    Zhou, C; Pinkerton, FE; Herbst, JF

    2014-05-07

    A series of novel alloys CeFe11-xCoxTi (0 <= x <= 11) with ThMn12 structure has been successfully prepared by melt-spinning. The Curie temperature T-c increases with Co content x, reaching a maximum of 689 degrees C at x = 9 and declining to 664 degrees C at complete Co filling (x = 11). The room temperature saturation magnetization 4 pi M-s and magnetocrystalline anisotropy H-a have been estimated by fitting the first quadrant demagnetization curve with the Stoner-Wohlfarth model. 4 pi M-s first increases with increasing Co up to x = 3, then decrease. H-a has a complex dependence on Co content, which is indicative of a change in the easy magnetization direction from axis to plane and back as the Co content increases. (C) 2014 AIP Publishing LLC.

  2. Response of Cs2LiYCl6:Ce (CLYC) to High Energy Protons

    SciTech Connect (OSTI)

    Coupland, Daniel David Schechtman; Stonehill, Laura Catherine; Goett, John Jerome III

    2015-11-23

    Cs2LiYCl6:Ce (CLYC) is a promising new inorganic scintillator for gamma and neutron detection. As a gamma-ray detector, it exhibits bright light output and better resolution and proportionality of response than traditional gamma-ray scintillators such as NaI. It is also highly sensitive to thermal neutrons through capture on 6Li, and recent experiments have demonstrated sensitivity to fast neutrons through interactions with 35Cl. The response of CLYC to other forms of radiation has not been reported. We have performed the first measurements of the response of CLYC to several-hundred MeV protons. We have collected digitized waveforms from proton events, and compare to those produced by gammas and thermal neutrons. Finally, we discuss the potential for pulse shape discrimination between them.

  3. High pressures and the Kondo gap in Ce{sub 3}Bi{sub 4}Pt{sub 3}

    SciTech Connect (OSTI)

    Cooley, J.C.; Aronson, M.C.; Canfield, P.C.

    1997-03-01

    We have measured the electrical resistivity {rho}(T) of single crystals of Ce{sub 3}Bi{sub 4}Pt{sub 3} for temperatures from 1.2 to 300 K, and pressures from 1 bar to 145 kbar. The transport is dominated at high temperatures by excitations across a small activation gap {Delta}, which increases rapidly with pressure. The low-temperature transport involves variable range hopping among extrinsic states in the gap. The spatial extent of the in-gap states reflects coupling to conduction-electron states, and is strongly modified as pressure enhances {Delta}. Despite the strong pressure dependence of {Delta}, a direct correspondence between single-ion energetics and the measured gap is maintained, and the role of valence fluctuations is minimal even at the highest pressures. {copyright} {ital 1997} {ital The American Physical Society}

  4. Low pressure CO₂ hydrogenation to methanol over gold nanoparticles activated on a CeOx/TiO₂ interface

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

    Yang, Xiaofang; Boscoboinik, J. Anibal; Kattel, Shyam; Senanayake, Sanjaya D.; Nie, Xiaowa; Graciani, Jesus; Rodriguez, Jose A.; Liu, Ping; Stacchiola, Dario J.; Chen, Jingguang G.

    2015-07-28

    Capture and recycling of CO₂ into valuable chemicals such as alcohols could help mitigate its emissions into the atmosphere. Due to its inert nature, the activation of CO₂ is a critical step in improving the overall reaction kinetics during its chemical conversion. Although pure gold is an inert noble metal and cannot catalyze hydrogenation reactions, it can be activated when deposited as nanoparticles on the appropriate oxide support. In this combined experimental and theoretical study, it is shown that an electronic polarization at the metal–oxide interface of Au nanoparticles anchored and stabilized on a CeOx/TiO₂ substrate generates active centers formore » CO₂ adsorption and its low pressure hydrogenation, leading to a higher selectivity toward methanol. In conclusion, this study illustrates the importance of localized electronic properties and structure in catalysis for achieving higher alcohol selectivity from CO₂ hydrogenation.« less

  5. Coadsorbed species explain the mechanism of methanol temperature-desorption on CeO2(111)

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

    Sutton, Jonathan E.; Steven H. Overbury; Beste, Ariana

    2016-03-24

    Here, we have used density functional theory calculations to investigate the temperature-programmed desorption (TPD) of methanol from CeO2(111). For the first time, low-temperature water formation and high-temperature methanol desorption are explained by our calculations. High coverages of methanol, which correspond to experimental conditions, are required to properly describe these features of the TPD spectrum. We identify a mechanism for the low-temperature formation of water involving the dissociation of two methanol molecules on the same surface O atom and filling of the resulting surface vacancy with one of the methoxy products. After water desorption, methoxy groups are stabilized on the surfacemore » and react at higher temperatures to form methanol and formaldehyde by a disproportionation mechanism. Alternatively, the stabilized methoxy groups undergo sequential C–H scission reactions to produce formaldehyde. Calculated energy requirements and methanol/formaldehyde selectivity agree with the experimental data.« less

  6. High Catalytic Activity of Au/CeOx/TiO2(110) Controlled by the Nature of the Mixed Metal Oxide at the Nanometer Level

    SciTech Connect (OSTI)

    Park, J.; Graciani, J; Evans, J; Stacchiola, D; Ma, S; Liu, P; Nambu, A; Sanz, J; Hrbek, J; et. al.

    2009-01-01

    Mixed-metal oxides play a very important role in many areas of chemistry, physics, materials science, and geochemistry. Recently, there has been a strong interest in understanding phenomena associated with the deposition of oxide nanoparticles on the surface of a second (host) oxide. Here, scanning tunneling microscopy, photoemission, and density-functional calculations are used to study the behavior of ceria nanoparticles deposited on a TiO2(110) surface. The titania substrate imposes nontypical coordination modes on the ceria nanoparticles. In the CeOx/TiO2(110) systems, the Ce cations adopt an structural geometry and an oxidation state (+3) that are quite different from those seen in bulk ceria or for ceria nanoparticles deposited on metal substrates. The increase in the stability of the Ce3+ oxidation state leads to an enhancement in the chemical and catalytic activity of the ceria nanoparticles. The codeposition of ceria and gold nanoparticles on a TiO2(110) substrate generates catalysts with an extremely high activity for the production of hydrogen through the water-gas shift reaction (H2O + CO ? H2 + CO2) or for the oxidation of carbon monoxide (2CO + O2 ? 2CO2). The enhanced stability of the Ce3+ state is an example of structural promotion in catalysis described here on the atomic level. The exploration of mixed-metal oxides at the nanometer level may open avenues for optimizing catalysts through stabilization of unconventional surface structures with special chemical activity.

  7. Mechanistic insights of ethanol steam reforming over Ni-CeOx(111): The importance of hydroxyl groups for suppressing coke formation

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

    Liu, Zongyuan; Senanayake, Sanjaya D.; Duchon, Tomas; Wang, Huanru; Peterson, Erik W.; Zhou, Yinghui; Luo, Si; Zhou, Jing; Matolin, Vladimir; Stacchiola, Dario J.; et al

    2015-07-10

    We have studied the reaction of ethanol and water over NiCeO2-x(111) model surfaces to elucidate the mechanistic steps associated with the ethanol steam reforming (ESR) reaction. Our results provide insights about the importance of hydroxyl groups to the ESR reaction over Ni-based catalysts. Systematically, we have investigated the reaction of ethanol on NiCeO2-x(111) at varying Ce? concentrations (CeO1.82.0) with absence/presence of water using a combination of soft X-ray photoelectron spectroscopy (sXPS) and temperature-programmed desorption (TPD). Consistent with previous reports, upon annealing, metallic Ni formed on reduced ceria while NiO was the main component on fully oxidized ceria. Ni? is themoreactive phase leading to both the CC and CH cleavage of ethanol but is also responsible for carbon accumulation or coking. We have identified a Ni?C phase that formed prior to the formation of coke. At temperatures above 600K, the lattice oxygen from ceria and the hydroxyl groups from water interact cooperatively in the removal of coke, likely through a strong metalsupport interaction between nickel and ceria that facilitates oxygen transfer.less

  8. UV absorption properties of ceria-modified compositions within the fluorite-type solid solution CeO{sub 2}-Y{sub 6}WO{sub 12}

    SciTech Connect (OSTI)

    Chevire, Francois; Munoz, Francisco; Baker, Charles F.; Tessier, Franck . E-mail: Franck.Tessier@univ-rennes1.fr; Larcher, Olivier; Boujday, Souhir; Colbeau-Justin, Christophe; Marchand, Roger

    2006-10-15

    A new fluorite-type solid solution domain has been evidenced in the system (1-x) CeO{sub 2}-x/7 Y{sub 6}WO{sub 12}{open_square}{sub 2} using the amorphous citrate route. All the studied phases (0{<=}x{<=}1) crystallize in a cubic-type symmetry. Diffuse reflectance spectra reveal a strong optical absorption between 380 and 400 nm. All substituted compositions spectral selectivities are estimated suitable for application as inorganic UV absorbers. The non linear variation observed in the optical gap values between Y{sub 6}WO{sub 12} and CeO{sub 2} is attributed to the presence of the cerium 4f-block band. Additionally, Time Resolved Microwave Conductivity (TRMC) experiment and phenol photodegradation analyses carried out on the Ce{sub 0.81}Y{sub 0.16}W{sub 0.03}O{sub 1.95}{open_square}{sub 0.05} (x=0.19) composition do not indicate any photocalatytic activity for this material. - Graphical abstract: Diffuse reflectance spectra of the Ce-Y-W-O samples calcined at 1000 deg. C.

  9. Inverse magnetocaloric effect in Ce(Fe{sub 0.96}Ru{sub 0.04}){sub 2}: Effect of fast neutron irradiation

    SciTech Connect (OSTI)

    Dube, V.; Mishra, P. K.; Prajapat, C. L.; Singh, M. R.; Ravikumar, G.; Rajarajan, A. K.; Sastry, P. U.; Thakare, S. V.

    2013-02-05

    We have shown the effect of fast neutron irradiation on the magnetic phase transition and magnetocaloric effect (MCE) in a doped Ce(Fe{sub 0.96}Ru{sub 0.04}){sub 2}, intermettalic. We show that this leads to suppression of MCE and a to a disordered ferromagnetic phase.

  10. Mechanistic Insights of Ethanol Steam Reforming over Ni–CeO x (111): The Importance of Hydroxyl Groups for Suppressing Coke Formation

    SciTech Connect (OSTI)

    Liu, Zongyuan; Duchoň, Tomáš; Wang, Huanru; Peterson, Erik W.; Zhou, Yinghui; Luo, Si; Zhou, Jing; Matolín, Vladimir; Stacchiola, Dario J.; Rodriguez, José A.; Senanayake, Sanjaya D.

    2015-07-30

    We have studied the reaction of ethanol and water over Ni–CeO2-x(111) model surfaces to elucidate the mechanistic steps associated with the ethanol steam reforming (ESR) reaction. Our results provide insights about the importance of hydroxyl groups to the ESR reaction over Ni-based catalysts. Systematically, we have investigated the reaction of ethanol on Ni–CeO2-x(111) at varying Ce³⁺ concentrations (CeO1.8–2.0) with absence/presence of water using a combination of soft X-ray photoelectron spectroscopy (sXPS) and temperature-programmed desorption (TPD). Consistent with previous reports, upon annealing, metallic Ni formed on reduced ceria while NiO was the main component on fully oxidized ceria. Ni⁰ is the active phase leading to both the C–C and C–H cleavage of ethanol but is also responsible for carbon accumulation or coking. We have identified a Ni₃C phase that formed prior to the formation of coke. At temperatures above 600K, the lattice oxygen from ceria and the hydroxyl groups from water interact cooperatively in the removal of coke, likely through a strong metal–support interaction between nickel and ceria that facilitates oxygen transfer.

  11. Mechanistic Insights of Ethanol Steam Reforming over Ni–CeO x (111): The Importance of Hydroxyl Groups for Suppressing Coke Formation

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

    Liu, Zongyuan; Duchoň, Tomáš; Wang, Huanru; Peterson, Erik W.; Zhou, Yinghui; Luo, Si; Zhou, Jing; Matolín, Vladimir; Stacchiola, Dario J.; Rodriguez, José A.; et al

    2015-07-30

    We have studied the reaction of ethanol and water over Ni–CeO2-x(111) model surfaces to elucidate the mechanistic steps associated with the ethanol steam reforming (ESR) reaction. Our results provide insights about the importance of hydroxyl groups to the ESR reaction over Ni-based catalysts. Systematically, we have investigated the reaction of ethanol on Ni–CeO2-x(111) at varying Ce³⁺ concentrations (CeO1.8–2.0) with absence/presence of water using a combination of soft X-ray photoelectron spectroscopy (sXPS) and temperature-programmed desorption (TPD). Consistent with previous reports, upon annealing, metallic Ni formed on reduced ceria while NiO was the main component on fully oxidized ceria. Ni⁰ is themore » active phase leading to both the C–C and C–H cleavage of ethanol but is also responsible for carbon accumulation or coking. We have identified a Ni₃C phase that formed prior to the formation of coke. At temperatures above 600K, the lattice oxygen from ceria and the hydroxyl groups from water interact cooperatively in the removal of coke, likely through a strong metal–support interaction between nickel and ceria that facilitates oxygen transfer.« less

  12. Data:F3d511d9-6321-49ce-b5b2-a0d21fd28d52 | Open Energy Information

    Open Energy Info (EERE)

    d9-6321-49ce-b5b2-a0d21fd28d52 No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading... 1....

  13. Crystal Chemistry and Luminescence of Ce3+ -Doped Lu2CaMg2(Si,Ge)3O12 and Its Use in LED Based Lighting

    SciTech Connect (OSTI)

    Setlur,A.; Heward, W.; Gao, Y.; Srivastava, A.; Chandron, R.; Shankar, M.

    2006-01-01

    In this paper, we describe the formation and luminescence of a new garnet phosphor for light emitting diode (LED) based lighting, Lu{sub 2}CaMg{sub 2}(Si,Ge){sub 3}O{sub 12}:Ce{sup 3+}.The regions for garnet phase formation are initially described with respect to larger rare earth substitution and show reasonable correlation to previous crystal chemistry studies for the garnet parent structure. While the pure silicate phosphor also has apatite second phases, a significant amount of Ce{sup 3+} enters the garnet phase, giving Ce{sup 3+} luminescence that is significantly redder when compared to typical Al{sup 3+} garnet phosphors with quantum efficiencies comparable to commercial Ce{sup 3+} garnet phosphors. Potential reasons for the emission red shift and the high quantum efficiency are discussed. Finally, the performance of these new phosphors is tested within LED based lamps. Lamps using these phosphors can reach color temperatures required for general illumination lighting and also have comparable phosphor conversion efficiencies when compared to lamps using typical garnet phosphors.

  14. Constitutive models for the Etchegoin Sands, Belridge Diatomite, and overburden formations at the Lost Hills oil field, California

    SciTech Connect (OSTI)

    FOSSUM,ARLO F.; FREDRICH,JOANNE T.

    2000-04-01

    This report documents the development of constitutive material models for the overburden formations, reservoir formations, and underlying strata at the Lost Hills oil field located about 45 miles northwest of Bakersfield in Kern County, California. Triaxial rock mechanics tests were performed on specimens prepared from cores recovered from the Lost Hills field, and included measurements of axial and radial stresses and strains under different load paths. The tested intervals comprise diatomaceous sands of the Etchegoin Formation and several diatomite types of the Belridge Diatomite Member of the Monterey Formation, including cycles both above and below the diagenetic phase boundary between opal-A and opal-CT. The laboratory data are used to drive constitutive parameters for the Extended Sandler-Rubin (ESR) cap model that is implemented in Sandia's structural mechanics finite element code JAS3D. Available data in the literature are also used to derive ESR shear failure parameters for overburden formations. The material models are being used in large-scale three-dimensional geomechanical simulations of the reservoir behavior during primary and secondary recovery.

  15. A New Stochastic Modeling of 3-D Mud Drapes Inside Point Bar Sands in Meandering River Deposits

    SciTech Connect (OSTI)

    Yin, Yanshu

    2013-12-15

    The environment of major sediments of eastern China oilfields is a meandering river where mud drapes inside point bar sand occur and are recognized as important factors for underground fluid flow and distribution of the remaining oil. The present detailed architectural analysis, and the related mud drapes' modeling inside a point bar, is practical work to enhance oil recovery. This paper illustrates a new stochastic modeling of mud drapes inside point bars. The method is a hierarchical strategy and composed of three nested steps. Firstly, the model of meandering channel bodies is established using the Fluvsim method. Each channel centerline obtained from the Fluvsim is preserved for the next simulation. Secondly, the curvature ratios of each meandering river at various positions are calculated to determine the occurrence of each point bar. The abandoned channel is used to characterize the geometry of each defined point bar. Finally, mud drapes inside each point bar are predicted through random sampling of various parameters, such as number, horizontal intervals, dip angle, and extended distance of mud drapes. A dataset, collected from a reservoir in the Shengli oilfield of China, was used to illustrate the mud drapes' building procedure proposed in this paper. The results show that the inner architectural elements of the meandering river are depicted fairly well in the model. More importantly, the high prediction precision from the cross validation of five drilled wells shows the practical value and significance of the proposed method.

  16. Investigation of the hydrothermal crystallisation of the perovskite solid solution NaCe{sub 1?x}La{sub x}Ti{sub 2}O{sub 6} and its defect chemistry

    SciTech Connect (OSTI)

    Harunsani, Mohammad H.; Woodward, David I.; Peel, Martin D.; Ashbrook, Sharon E.; Walton, Richard I.

    2013-11-15

    Perovskites of nominal composition NaCe{sub 1?x}La{sub x}Ti{sub 2}O{sub 6} (0?x?1) crystallise directly under hydrothermal conditions at 240 C. Raman spectroscopy shows distortion from the ideal cubic structure and Rietveld analysis of powder X-ray and neutron diffraction reveals that the materials represent a continuous series in rhombohedral space group R3-bar c. Ce L{sub III}-edge X-ray absorption near edge structure spectroscopy shows that while the majority of cerium is present as Ce{sup 3+} there is evidence for Ce{sup 4+}. The paramagnetic Ce{sup 3+} affects the chemical shift and line width of {sup 23}Na MAS NMR spectra, which also show with no evidence for A-site ordering. {sup 2}H MAS NMR of samples prepared in D{sub 2}O shows the inclusion of deuterium, which IR spectroscopy shows is most likely to be as D{sub 2}O. The deuterium content is highest for the cerium-rich materials, consistent with oxidation of some cerium to Ce{sup 4+} to provide charge balance of A-site water. - Graphical abstract: A multi-element A-site perovskite crystallises directly from aqueous, basic solutions at 240 C; while the paramagnetic effect of Ce{sup 3+} on the {sup 23}Na NMR shows a homogeneous solid-solution, the incorporation of A-site water is also found from {sup 2}H NMR and IR, with oxidation of some cerium to charge balance proved by XANES spectroscopy. Display Omitted - Highlights: Direct hydrothermal synthesis allows crystallisation of a perovskite solid-solution. XANES spectroscopy shows some oxidation of Ce{sup 3+} to Ce{sup 4+}. The paramagnetism of Ce{sup 3+} shifts and broadens the {sup 23}Na solid-state NMR. The perovskite materials incorporate water as an A-site defect.

  17. Water–gas shift reaction over gold nanoparticles dispersed on nanostructured CeOx–TiO2(110) surfaces: Effects of high ceria coverage

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

    Grinter, D. C.; Park, J. B.; Agnoli, S.; Evans, J.; Hrbek, J.; Stacchiola, D. J.; Senanayake, S. D.; Rodriguez, J. A.

    2016-08-01

    We used scanning tunnelling microscopy to study the morphology of an overlayer of ceria in contact with a TiO2(110) substrate. Two types of domains were observed after ceria deposition. An ordered ceria film covered half of the surface and high-resolution imaging suggested a near-c(6 × 2) relationship to the underlying TiO2(110)-(1 × 1). For the other half of the surface, it comprised CeOx nanoparticles and reconstructed TiOx supported on TiO2(110)-(1 × 1). Exposure to a small amount of gold resulted in the formation of isolated gold atoms and small clusters on the ordered ceria film and TiO2(110)-(1 × 1) areas,more » which exhibited significant sintering at 500 K and showed strong interaction between the sintered gold clusters and the domain boundaries of the ceria film. The Au/CeOx/TiO2(110) model system proved to be a good catalyst for the water–gas shift (WGS) exhibiting much higher turnover frequencies (TOFs) than Cu(111) and Pt(111) benchmarks, or the individual Au/TiO2(110) and Au/CeO2(111) systems. Finally, for Au/CeOx/TiO2(110) catalysts, there was a decrease in catalytic activity with increasing ceria coverage that correlates with a reduction in the concentration of Ce3 + formed during WGS reaction conditions.« less

  18. System and process for the abatement of casting pollution, reclaiming resin bonded sand, and/or recovering a low BTU fuel from castings

    DOE Patents [OSTI]

    Scheffer, Karl D.

    1984-07-03

    Air is caused to flow through the resin bonded mold to aid combustion of the resin binder to form a low BTU gas fuel. Casting heat is recovered for use in a waste heat boiler or other heat abstraction equipment. Foundry air pollution is reduced, the burned portion of the molding sand is recovered for immediate reuse and savings in fuel and other energy is achieved.

  19. System and process for the abatement of casting pollution, reclaiming resin bonded sand, and/or recovering a low Btu fuel from castings

    DOE Patents [OSTI]

    Scheffer, K.D.

    1984-07-03

    Air is caused to flow through the resin bonded mold to aid combustion of the resin binder to form a low Btu gas fuel. Casting heat is recovered for use in a waste heat boiler or other heat abstraction equipment. Foundry air pollutis reduced, the burned portion of the molding sand is recovered for immediate reuse and savings in fuel and other energy is achieved. 5 figs.

  20. Laboratory Enrichment of Radioactive Assemblages and Estimation of Thorium and Uranium Radioactivity in Fractions Separated from Placer Sands in Southeast Bangladesh

    SciTech Connect (OSTI)

    Sasaki, Takayuki; Rajib, Mohammad; Akiyoshi, Masafumi; Kobayashi, Taishi; Takagi, Ikuji; Fujii, Toshiyuki; Zaman, Md. Mashrur

    2015-06-15

    The present study reports the likely first attempt of separating radioactive minerals for estimation of activity concentration in the beach placer sands of Bangladesh. Several sand samples from heavy mineral deposits located at the south-eastern coastal belt of Bangladesh were processed to physically upgrade their radioactivity concentrations using plant and laboratory equipment. Following some modified flow procedure, individual fractions were separated and investigated using gamma-ray spectrometry and powder-XRD analysis. The radioactivity measurements indicated contributions of the thorium and uranium radioactive series and of {sup 40}K. The maximum values of {sup 232}Th and {sup 238}U, estimated from the radioactivity of {sup 208}Tl and {sup 234}Th in secular equilibrium, were found to be 152,000 and 63,300 Bq/kg, respectively. The fraction of the moderately conductive part in electric separation contained thorium predominantly, while that of the non-conductive part was found to be uranium rich. The present arrangement of the pilot plant cascade and the fine tuning of setting parameters were found to be effective and economic separation process of the radioactive minerals from placer sands in Bangladesh. Probable radiological impacts and extraction potentiality of such radioactive materials are also discussed.