National Library of Energy BETA

Sample records for mineral gadolinite ce

  1. Ce Yang | Argonne National Laboratory

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Ce Yang Postdoctoral Appointee Telephone (630) 252-640

  2. CE Geothermal | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

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

  3. 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 ...

  4. Clay Minerals

    SciTech Connect

    Mueller, Karl T.; Sanders, Rebecca L.; Washton, Nancy M.

    2014-03-14

    Clay minerals are important components of the environment and are involved or implicated in processes such as the uptake of pollutants and the release of nutrients and as potential platforms for a number of chemical reactions. Owing to their small particle sizes (typically, on the order of microns or smaller) and mixing with a variety of other minerals and soil components, advanced characterization methods are needed to study their structures, dynamics, and reactivities. In this article, we describe the use of solid-state NMR methods to characterize the structures and chemistries of clay minerals. Early one-pulse magic-angle spinning (MAS) NMR studies of 27Al and 29Si have now been enhanced and extended with new studies utilizing advanced methodologies (such as Multiple Quantum MAS) as well as studies of less-sensitive nuclei. In additional work, the issue of reactivity of clay minerals has been addressed, including studies of reactive surface area in the environment. Utilizations of NMR-sensitive nuclides within the clay minerals themselves, and in molecules that react with speci?c sites on the clay mineral surfaces, have aided in understanding the reactivity of these complex aluminosilicate systems.

  5. CE Solar | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    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....

  6. Mineral Magnetism

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Mineral Magnetism 1663 Los Alamos science and technology magazine Latest Issue:July 2016 past issues All Issues » submit Mineral Magnetism By understanding what makes a material magnetic, scientists want to create new strongly magnetic materials that don't rely on hard-to-get precursor elements. March 8, 2016 Small piles of rare earth elements In the United States, rare-earth elements used in strong magnets, such as neodymium and samarium, are scarce due to limits on foreign sources. CREDIT:

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

    Energy.gov [DOE] (indexed site)

    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 ...

  8. 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 ...

  9. 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...

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

    Energy.gov [DOE] (indexed site)

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

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

    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.

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

    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.

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

    SciTech Connect

    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.

  14. Effect of rare earth Ce on the far infrared radiation property of iron ore tailings ceramics

    SciTech Connect

    Liu, Jie; Meng, Junping; Liang, Jinsheng; Duan, Xinhui; Huo, Xiaoli; Tang, Qingguo

    2015-06-15

    Highlights: • Detailed process proposed for preparation of iron ore tailings ceramics. • Replace natural minerals with iron ore tailings as raw materials for preparing functional ceramics. • Impact mechanism of Ce on far infrared ceramics, as well as its optimum addition amounts can be obtained. • Propose a new perspective on considering the mechanism of far infrared radiation. - Abstract: A kind of far infrared radiation ceramics was prepared by using iron ore tailings, CaCO{sub 3} and SiO{sub 2} as main raw materials, and Ce as additive. The result of Fourier transform infrared spectroscopy showed that the sample exhibits excellent radiation value of 0.914 when doping 7 wt.% Ce. Ce{sup 4+} dissolved into iron diopside and formed interstitial solid solution with it sintered at 1150 °C. The oxidation of Fe{sup 2+} to Fe{sup 3+} caused by Ce{sup 4+} led to a decrease of crystallite sizes and enhancement of Mg–O and Fe–O vibration in iron diopside, which consequently improved the far infrared radiation properties of iron ore tailings ceramics.

  15. California Ethanol Power CE P | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

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

  16. CeCap LLP | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    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...

  17. 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...

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

    SciTech Connect

    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.

  19. 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...

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

    DOE PAGES [OSTI]

    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

  1. 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

  2. High thermal stability of La2O3 and CeO2-stabilized tetragonal ZrO2

    DOE PAGES [OSTI]

    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

  3. Minerals Technologies | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Technologies Jump to: navigation, search Name: Minerals Technologies Place: Bethlehem, PA Website: www.mineralstechnologies.com References: Minerals Technologies1 Information...

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

    SciTech Connect

    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.

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

    DOE PAGES [OSTI]

    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

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

    DOE PAGES [OSTI]

    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

  7. Oak Ridge Field O%ce

    Office of Legacy Management (LM)

    DOC F ' ;fz; , NiJlo-2- - ' U ' ted St tes Go e e t kh&~~durn Der>artment of Energy rm jl# Oak Ridge Field O%ce DATE: June 21, 1993 REPLY TO ATTW Of: EW-93:Hartman SUBJECT: WAYNE INTERIM STORAGE SITE - TERMINATION OF SITE ENVIRONMENTAL REPORT TO: Peter 3. Gross, Director, Environmental Protection Division, SE-31 The Wayne Interim Storage Site (WISS) is part of the Formerly Utilized Sites Remedial Action Program. Based upon our surveillance efforts at WISS since 1984, the data for all

  8. 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

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

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Atosa: 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 &

  10. 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

  11. Bioleaching of Minerals

    SciTech Connect

    F. Roberto

    2002-02-01

    Bioleaching is the term used to describe the microbial dissolution of metals from minerals. The commercial bioleaching of metals, particularly those hosted in sulfide minerals, is supported by the technical disciplines of biohydrometallurgy, hydrometallurgy, pyrometallurgy, chemistry, electrochemistry, and chemical engineering. The study of the natural weathering of these same minerals, above and below ground, is also linked to the fields of geomicrobiology and biogeochemistry. Studies of abandoned and disused mines indicate that the alterations of the natural environment due to man's activities leave as remnants microbiological activity that continues the biologically mediated release of metals from the host rock (acid rock drainage; ARD). A significant fraction of the world's copper, gold and uranium is now recovered by exploiting native or introduced microbial communities. While some members of these unique communities have been extensively studied for the past 50 years, our knowledge of the composition of these communities, and the function of the individual species present remains relatively limited. Nevertheless, bioleaching represents a major strategy in mineral resource recovery whose importance will increase as ore reserves decline in quality, become more difficult to process (due to increased depth, increased need for comminution, for example), and as environmental considerations eliminate traditional physical processes such as smelting, which have served the mining industry for hundreds of years.

  12. CE2 Capital Partners LLC | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

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

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  15. Taxation of mineral resources

    SciTech Connect

    Conrad, R.F.; Hool, R.B.

    1980-01-01

    There has been a substantial increase in recent years in the level of taxation imposed on mining firms by state and local governments. This increase can be attributed to three factors: (1) a heightened awareness that resources are limited in quantity; (2) environmental damage resulting from mining operations has brought demands for just compensations; and (3) significant price increases for some minerals have often been viewed by states as an opportunity to collect additional tax revenue. The broad aim of this book is to provide a comprehensive economic analysis of the effects of mining taxation on the extraction of mineral resources and to offer a set of recommendations for tax policy. The primary objective of this design is to minimize the distortionary incentives created by the taxation. From a practical standpoint, however, one must also recognize the degrees of difficulty in the administration of the various taxes. 90 references, 1 figure, 14 tables.

  16. Nevada Division of Minerals | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Logo: Nevada Division of Minerals Name: Nevada Division of Minerals Address: 400 W. King St. 106 Place: Carson City, Nevada Zip: 89703 Website: minerals.state.nv.us...

  17. Hearing protection for miners

    SciTech Connect

    Schulz, T.

    2008-10-15

    A NIOSH analysis showed that at age 50 approximately 90% of coal miners have a hearing impairment, yet noise included hearing loss is 100% preventable. The article discusses requirements of the MSHA regulations, 30 CFR Part 62 - occupational noise exposure (2000) and a 2008-MSHA document describing technologically achievable and promising controls for several types of mining machinery. Hearing protection is still required for exposure to greater than 90 dBA. These are now commercially available ways to determine how much attenuation an individual gets from a given hearing protector, known as 'fit testing'. 3 refs., 1 fig., 1 tab., 1 photo.

  18. 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 ...

  19. Processing of transparent polycrystalline AlON:Ce3+ scintillators

    DOE PAGES [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+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

  20. Mineral industries of Australia, Canada, and Oceania (including a discussion of Antarctica's mineral resources). Mineral perspective

    SciTech Connect

    Kimbell, C.L.; Lyday, T.Q.; Newman, H.H.

    1985-12-01

    The Bureau of Mines report gives the mineral industry highlights of two of the world's major mineral producing countries, Australia and Canada, and seven Pacific island nations or territories--Fiji, New Caledonia, New Zealand, Papua New Guinea, Republic of Nauru, Solomon Islands, and Vanuatu. The mineral resources of Antarctica are also discussed. Because of the size of the Australian and Canadian mineral industries, summary reviews are presented for each of the States, Provinces, or Territories. The most current information available from all nations is given on major minerals or mineral-commodity production, share of world production, and reserves. Reported also are significant mining companies, locations and capacities of their main facilities, and their share of domestic production. Other information is provided on mineral-related trade with the United States, government mineral policy, energy production-consumption and trade, the mining industry labor force, and prospects for the mineral industry. Maps show the locations of selected mineral deposits, oilfields and gasfields, mines, and processing facilities including iron and steel plants, nonferrous smelters and refineries, and cement plants, as well as infrastructure pertinent to the mineral industry.

  1. 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

  2. School Air: Order (2016-CE-43004) | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Order (2016-CE-43004) School Air: Order (2016-CE-43004) March 9, 2016 DOE ordered School Air Mfg. Corp. d/b/a School Air, Inc. to pay a $8,000 civil penalty after finding School Air 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 School Air. School Air: Order (2016-CE-43004) (21.86 KB) More

  3. Minerals Yearbook: Minerals in the world economy. 1988 International review

    SciTech Connect

    Kimbell, C.L.; Zajac, W.L.

    1988-01-01

    In overview, 1988 appeared to be the best year for the world's mineral industry since 1980, although the all-important petroleum component suffered severely from low prices. With this notable exception, the traditional statistical measures of mineral industry performance, namely production, trade, and consumption, reflected growth in most elements of the world mineral industry from crude material extraction through the gamut of downstream processing. Moreover, the growth was reasonably well distributed geographically, with many countries sharing in the substantial upturn in activity. The report discusses production, trade, consumption, investment, transportation, prices, and statistical summary of world production and trade of major mineral commodities.

  4. CE2 Carbon Capital LLC | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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

  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. Equator: Order (2015-CE-20007) | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Equator: Order (2015-CE-20007) Equator: Order (2015-CE-20007) August 9, 2016 DOE ordered Equator Advanced Appliances to pay a $8,000 civil penalty after finding Equator had failed to certify that certain residential clothes washers and residential clothes dryers comply with the applicable energy conservation standards. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Equator. DOE alleged in a March 1, 2016 Notice of Proposed Civil Penalty that Equator

  13. Ritemp Refrigeration: Order (2016-CE-53014) | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Ritemp Refrigeration: Order (2016-CE-53014) Ritemp Refrigeration: Order (2016-CE-53014) July 19, 2016 DOE ordered Ritemp Refrigeration, Inc. to pay a $6,000 civil penalty after finding Ritemp Refrieration had failed to certify that certain walk-in cooler and freezer components comply with the applicable energy conservation standards. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Ritemp Refrigeration. DOE alleged in a June 6, 2016 Notice of Proposed

  14. Sanyo Electric: Order (2010-CE-1210) | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Sanyo Electric: Order (2010-CE-1210) Sanyo Electric: Order (2010-CE-1210) October 13, 2010 DOE issued an Order and entered into a Compromise Agreement with Sanyo E&E Corp. after finding Sanyo had used an improper method to submit its certification that certain models of residential refrigerators, refrigerator-freezers, and freezers comply with the applicable energy conservation standards. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Sanyo. Sanyo

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

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Proposed Penalty (2016-CE-43004) School Air: Proposed Penalty (2016-CE-43004) February 5, 2016 DOE alleged in a Notice of Proposed Civil Penalty that School Air Mfg. Corp. d/b/a School Air, Inc. failed to certify 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

  16. 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

  17. 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

  18. General Restaurant Equipment: Order (2016-CE-53010) | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Restaurant Equipment: Order (2016-CE-53010) General Restaurant Equipment: Order (2016-CE-53010) July 15, 2016 DOE ordered General Restaurant Equipment Co. to pay a $16,000 civil penalty after finding General Restaurant Equipment had failed to certify that certain models of walk-in cooler and freezer components comply with the applicable energy conservation standards. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and General Restaurant Equipment. DOE

  19. 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

  20. Ca2+-Doped CeBr3 Scintillating Materials

    SciTech Connect

    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.

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

    DOE PAGES [OSTI]

    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

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

    SciTech Connect

    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.

  3. Universal ripper miner

    DOEpatents

    Morrell, Roger J.; Larson, David A.

    1991-01-01

    A universal ripper miner used to cut, collect and transfer material from an underground mine working face includes a cutter head that is vertically movable in an arcuate cutting cycle by means of drive members, such as hydraulically actuated pistons. The cutter head may support a circular cutter bit having a circular cutting edge that may be indexed to incrementally expose a fresh cutting edge. An automatic indexing system is disclosed wherein indexing occurs by means of a worm gear and indexing lever mechanism. The invention also contemplates a bi-directional bit holder enabling cutting to occur in both the upstroke and the downstroke cutting cycle. Another feature of the invention discloses multiple bits arranged in an in-line, radially staggered pattern, or a side-by-side pattern to increase the mining capacity in each cutting cycle. An on-board resharpening system is also disclosed for resharpening the cutting edge at the end of cutting stroke position. The aforementioned improvement features may be used either singly, or in any proposed combination with each other.

  4. An Update on NiCE Support for BISON

    SciTech Connect

    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.

  5. Property:MineralManager | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    MineralManager Jump to: navigation, search Property Name MineralManager Property Type Page Pages using the property "MineralManager" Showing 25 pages using this property. (previous...

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

    SciTech Connect

    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.

  7. A highly conspicuous mineralized composite photonic architecture...

    Office of Scientific and Technical Information (OSTI)

    A highly conspicuous mineralized composite photonic architecture in the translucent shell of the blue-rayed limpet Title: A highly conspicuous mineralized composite photonic ...

  8. China Gengsheng Minerals Inc | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Gengsheng Minerals Inc Jump to: navigation, search Name: China Gengsheng Minerals Inc Place: Henan Province, China Product: China-based material technology company. References:...

  9. Minerals in the world economy. Minerals yearbook Volume 3. 1991 international review

    SciTech Connect

    Kimbell, C.L.

    1991-12-31

    This edition of the Minerals Yearbook - International Review records the performance of the worldwide minerals industry during 1991 and provides background information to assist in interpreting that performance. Volume III, International Review, contains the latest available mineral data on more than 150 foreign countries and discusses the importance of minerals to the economies of these nations. The 1991 review is presented as five area reports and one world overview: Mineral Industries of Africa, Mineral Industries of Asia and the Pacific, Mineral Industries of Latin America and Canada, Mineral Industries of Europe and the U.S.S.R., Mineral Industries of the Middle East, and Minerals in the World Economy.

  10. CRYSTAL CHEMISTRY OF HYDROUS MINERALS

    SciTech Connect

    Y. ZHAO; ET AL

    2001-02-01

    Hydrogen has long been appreciated for its role in geological processes of the Earth's crust. However, its role in Earth's deep interior has been neglected in most geophysical thinking. Yet it is now believed that most of our planet's hydrogen may be locked up in high pressure phases of hydrous silicate minerals within the Earth's mantle. This rocky interior (approximately 7/8 of Earth's volume) is conjectured to contain 1-2 orders of magnitude more water than the more obvious oceans (the ''hydrosphere'') and atmosphere. This project is aimed at using the capability of neutron scattering from hydrogen to study the crystal chemistry and stability of hydrogen-bearing minerals at high pressures and temperatures. At the most basic level this is a study of the atomic position and hydrogen bond itself. We have conducted experimental runs on hydrous minerals under high pressure and high temperature conditions. The crystallographic structure of hydrous minerals at extreme conditions and its structural stability, and hydrogen bond at high P-T conditions are the fundamental questions to be addressed. The behavior of the hydrous minerals in the deep interior of the Earth has been discussed.

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

    OpenEI (Open Energy Information) [EERE & EIA]

    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...

  12. 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 ...

  13. 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. ...

  14. 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 April 2013 (330.47 KB) October 2013 ...

  15. 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...

  16. 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 ...

  17. 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 ...

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  20. CO Oxidation mechanism on CeO2-supported Au nanoclusters

    SciTech Connect

    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.

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  3. Ukrainian mineral wax from brown coal

    SciTech Connect

    Shabad, T.

    1986-07-01

    An unusual mineral enterprise is the mineral wax plant of Semenovskoye in the Aleksandriya brown coal basin of the Ukraine. The only plant of its kind in the Soviet Union, it has been in operation since 1959, extracting mineral wax from the local bitumen-rich brown coal. The plant yields about 7.5 tons of mineral wax a day (about 2700 tons a year), for use in a variety of applications.

  4. Review of 1989 international mineral industry activities

    SciTech Connect

    Kimbell, C.L. (US Bureau of Mines, Washington, DC (US))

    1990-07-01

    This article reviews global mineral industry activities for 1989. Production of coal, natural gas, and petroleum, as well as non-fuel minerals, is detailed regionally and for individual countries. The problems of changes in technology, economic and political systems are discussed where they have affected mineral production.

  5. LOW TEMPERATURE GEOTHERMAL MINERAL RECOVERY PROGRAM 02/11/2014...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    LOW TEMPERATURE GEOTHERMAL MINERAL RECOVERY PROGRAM 02112014 LOW TEMPERATURE GEOTHERMAL MINERAL RECOVERY PROGRAM 02112014 mineral-webinar.pdf (3.45 MB) More Documents & ...

  6. Oregon Department of Geology and Mineral Industries | Open Energy...

    OpenEI (Open Energy Information) [EERE & EIA]

    Geology and Mineral Industries Jump to: navigation, search Logo: Oregon Department of Geology and Mineral Industries Name: Oregon Department of Geology and Mineral Industries...

  7. New Mexico Energy, Minerals and Natural Resources Department...

    OpenEI (Open Energy Information) [EERE & EIA]

    Minerals and Natural Resources Department Jump to: navigation, search Logo: New Mexico Energy, Minerals and Natural Resources Department Name: New Mexico Energy, Minerals...

  8. Immobilization of actinides in stable mineral type and ceramic materials (high temperature synthesis)

    SciTech Connect

    Starkov, O.; Konovalov, E.

    1996-05-01

    Alternative vitrification technologies are being developed in the world for the immobilization of high radioactive waste in materials with improved thermodynamic stability, as well as improved chemical and thermal stability and stability to radiation. Oxides, synthesized in the form of analogs to rock-forming minerals and ceramics, are among those materials that have highly stable properties and are compatible with the environment. In choosing the appropriate material, we need to be guided by its geometric stability, the minimal number of cations in the structure of the material and the presence of structural elements in the mineral that are isomorphs of uranium and thorium, actinoids found in nature. Rare earth elements, yttrium, zirconium and calcium are therefore suitable. The minerals listed in the table (with the exception of the zircon) are pegatites by origin, i.e. they are formed towards the end of the magma crystallization of silicates form the residual melt, enriched with Ta, Nb, Ti, Zr, Ce, Y, U and Th. Uranium and thorium in the form of isomorphic admixtures form part of the lattice of the mineral. These minerals, which are rather simple in composition and structure and are formed under high temperatures, may be viewed as natural physio-chemical systems that are stable and long-lived in natural environments. The similarity of the properties of actinoids and lanthanoids plays an important role in the geochemistry of uranium and thorium; however, uranium (IV) is closer to the {open_quotes}heavy{close_quotes} group of lanthanoids (the yttrium group) while thorium (IV) is closer to the {open_quotes}light{close_quotes} group (the cerium group). That is why rare earth minerals contain uranium and thorium in the form of isomorphic admixtures.

  9. Mineralization of Carbon Dioxide: Literature Review

    SciTech Connect

    Romanov, V; Soong, Y; Carney, C; Rush, G; Nielsen, B; O'Connor, W

    2015-01-01

    CCS research has been focused on CO2 storage in geologic formations, with many potential risks. An alternative to conventional geologic storage is carbon mineralization, where CO2 is reacted with metal cations to form carbonate minerals. Mineralization methods can be broadly divided into two categories: in situ and ex situ. In situ mineralization, or mineral trapping, is a component of underground geologic sequestration, in which a portion of the injected CO2 reacts with alkaline rock present in the target formation to form solid carbonate species. In ex situ mineralization, the carbonation reaction occurs above ground, within a separate reactor or industrial process. This literature review is meant to provide an update on the current status of research on CO2 mineralization. 2

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  12. Strata control in mineral engineering

    SciTech Connect

    Bieniawski, Z.T.

    1986-01-01

    This book covers the state-of-the-art of strata control practice both in the United States and abroad with respect to strata reinforcement by rock bolting, long wall mining technology and innovations in energy development, such as mining for oil and tunneling for storage of high-level nuclear waste in deep underground repositories. It features coverage of design concepts in rock engineering and rockbolt systems, stability of rock pillars, rockbursts, shaft design and construction and a detailed consideration of mineral and energy needs in the United States.

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

    Office of Science (SC)

    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

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

    SciTech Connect

    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

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

    DOE PAGES [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 -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

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

    SciTech Connect

    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.

  17. Thermoelectric Couple Demonstration of (In, Ce)-based Skutterudite Materials for Automotive Energy Recovery

    Energy.gov [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 commercial applications

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

    Energy.gov [DOE] (indexed site)

    Thermoelectric and structural properties of n-type (In, Ce) filled skutterudites including ... High-Temperature Waste Heat Recovery Thermoelectric Couple Demonstration of (In, ...

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

    SciTech Connect

    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.

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

    DOEpatents

    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.

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

    DOEpatents

    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.

  2. Mineral Resource Information System for Field Lab in the Osage Mineral Reservation Estate

    SciTech Connect

    Carroll, H.B.; Johnson, William I.

    1999-04-27

    The Osage Mineral Reservation Estate is located in Osage County, Oklahoma. Minerals on the Estate are owned by members of the Osage Tribe who are shareholders in the Estate. The Estate is administered by the Osage Agency, Branch of Minerals, operated by the U.S. Bureau of Indian Affairs (BIA). Oil, natural gas, casinghead gas, and other minerals (sand, gravel, limestone, and dolomite) are exploited by lessors. Operators may obtain from the Branch of Minerals and the Osage Mineral Estate Tribal Council leases to explore and exploit oil, gas, oil and gas, and other minerals on the Estate. Operators pay a royalty on all minerals exploited and sold from the Estate. A mineral Resource Information system was developed for this project to evaluate the remaining hydrocarbon resources located on the Estate. Databases on Microsoft Excel spreadsheets of operators, leases, and production were designed for use in conjunction with an evaluation spreadsheet for estimating the remaining hydrocarbons on the Estate.

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

    SciTech Connect

    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.

  4. Interface Induced Carbonate Mineralization: A Fundamental Geochemical

    Office of Scientific and Technical Information (OSTI)

    Interface Induced Carbonate Mineralization: A Fundamental Geochemical Process Relevant to Carbon Sequestration Teng, H. Henry PI, The George Washington University PI, The George...

  5. Geology and Minerals | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Jump to: navigation, search Retrieved from "http:en.openei.orgwindex.php?titleGeologyandMinerals&oldid612244" Feedback Contact needs updating Image needs updating...

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

    DOE PAGES [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 inmore » agreement with magnetic susceptibility measurements.« less

  7. Minerals Yearbook, 1988. The mineral industries of the Arabian Peninsula and Persian Gulf countries. International review

    SciTech Connect

    Michalski, B.; Antonides, L.E.; Morgan, G.A.

    1988-01-01

    The document contains commodity reviews (metals, mineral fuels, industrial minerals where applicable) for the following countries: Bahrain, Iran, Iraq, Kuwait, Oman, Qatar, Saudi Arabia, United Arab Emirates, People's Democratic Republic of Yeman, and Yeman Arab Republic.

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

    SciTech Connect

    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}.

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

    DOEpatents

    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.

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

    DOEpatents

    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.

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

    SciTech Connect

    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%).

  12. 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 ...

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  15. Adsorption of polyacrylamides on mineral surfaces

    SciTech Connect

    Lecourtier, J.; Lee, L.T.; Chauveteau, G.

    1987-01-01

    The adsorption of neutral and hydrolyzed polyacrylamides, which are currently used in enhanced oil recovery, on minerals the surfaces of which carry silanol and aluminol groups such as siliceous minerals and akolinite is studied. All experiments are conducted in batch on powdered minerals. The conditions for the elimination of detrimental effects of both mechanical degradation of polymers and flocculation of mineral particles during the batch experiments have been determined, leading to a reliable methodology for the adsorption measurements. The surface sites responsible for adsorption are identified, and a change in surface charge by thermal pretreatment of minerals is found to alter the polymer adsorption accordingly. The two main results thus derived from this study are: a methodology providing reliable and reproducible data, and, the identification of the mechanisms of polymer adsorption and the major parameters governing the process.

  16. Minerals Yearbook, 1988 international review. The mineral industries of Bolivia, Ecuador, and Peru

    SciTech Connect

    Torres, I.E.; Gurmendi, A.C.; Velasco, P.

    1988-01-01

    All three countries in this Andean group have diversified mineral industries that play an important role in their respective domestic economies. Peru, as the largest country with a population of over 21 million, is the most diversified mineral producer with the highest value of total output. The values added by the mineral industries in 1988 were $2.78 billion for Peru, $1.98 billion for Ecuador, and $0.64 billion for Bolivia. Each value encompasses production of petroleum, natural gas, metals, and industrial minerals. During the period 1980-88, Ecuador's mineral output in terms of value expanded while that of Bolivia and Peru contracted.

  17. Minerals yearbook: Mineral industries of Europe and central Eurasia. Volume 3. 1992 international review

    SciTech Connect

    Not Available

    1992-01-01

    Volume III, Minerals Yearbook -- International Review contains the latest available mineral data on more than 175 foreign countries and discusses the importance of minerals to the economies of these nations. Since the 1989 International Review, the volume has been presented as six reports. The report presents the Mineral Industries of Europe and Central Eurasia. The report incorporates location maps, industry structure tables, and an outlook section previously incorporated in the authors' Minerals Perspectives Series quinquennial regional books, which are being discontinued. This section of the Minerals Yearbook reviews the minerals industries of 45 countries: the 12 nations of the European Community (EC); 6 of the 7 nations of the European Free Trade Association (EFTA); Malta; the 11 Eastern European economies in transition (Albania, Bosnia and Hercegovina, Bulgaria, Croatia, Czechoslovakia, Hungary, Macedonia, Poland, Romania, Serbia and Montenegro, and Slovenia); and the countries of Central Eurasia (Armenia, Azerbaijan, Belarus, Estonia, Georgia, Kazakhstan, Kyrgystan, Latvia, Lithuania, Moldova, Russia, Tajikistan, Turkmenistan, Ukraine, and Uzbekistan).

  18. Mineral Selection for Multicomponent Equilibrium Geothermometry

    DOE PAGES [OSTI]

    Plamer, C. D.; Ohly, S. R.; Smith, R. W.; Neupane, G.; McLing, T.; Mattson, E.

    2015-04-01

    Multicomponent geothermometry requires knowledge of the mineral phases in the reservoir with which the geothermal fluids may be equilibrated. These minerals phases are most often alteration products rather than primary minerals. We have reviewed the literature on geothermal systems representing most major geologic environments typically associated with geothermal activity and identified potential alteration products in various environments. We have included this information in RTEst, a code we have developed to estimate reservoir conditions (temperature, CO2 fugacity) from the geochemistry of near-surface geothermal waters. The information has been included in RTEst through the addition of filters that decrease the potential numbermore » of minerals from all possibilities based on the basis species to those that are more relevant to the particular conditions in which the user is interested. The three groups of filters include host rock type (tholeiitic, calc-alkaline, silicic, siliciclastic, carbonate), water type (acidic, neutral), and the temperature range over which the alteration minerals were formed (low, medium, high). The user-chosen mineral assemblage is checked to make sure that it does not violate the Gibbs phase rule. The user can select one of three mineral saturation weighting schemes that decrease the chance the optimization from being skewed by reaction stoichiometry or analytical uncertainty.« less

  19. Mineral Selection for Multicomponent Equilibrium Geothermometry

    SciTech Connect

    Plamer, C. D.; Ohly, S. R.; Smith, R. W.; Neupane, G.; McLing, T.; Mattson, E.

    2015-04-01

    Multicomponent geothermometry requires knowledge of the mineral phases in the reservoir with which the geothermal fluids may be equilibrated. These minerals phases are most often alteration products rather than primary minerals. We have reviewed the literature on geothermal systems representing most major geologic environments typically associated with geothermal activity and identified potential alteration products in various environments. We have included this information in RTEst, a code we have developed to estimate reservoir conditions (temperature, CO2 fugacity) from the geochemistry of near-surface geothermal waters. The information has been included in RTEst through the addition of filters that decrease the potential number of minerals from all possibilities based on the basis species to those that are more relevant to the particular conditions in which the user is interested. The three groups of filters include host rock type (tholeiitic, calc-alkaline, silicic, siliciclastic, carbonate), water type (acidic, neutral), and the temperature range over which the alteration minerals were formed (low, medium, high). The user-chosen mineral assemblage is checked to make sure that it does not violate the Gibbs phase rule. The user can select one of three mineral saturation weighting schemes that decrease the chance the optimization from being skewed by reaction stoichiometry or analytical uncertainty.

  20. Studies on Ca2+-Doped CeBr3 Scintillating Materials

    SciTech Connect

    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.

  1. Processing of transparent polycrystalline AlON:Ce3+ scintillators

    SciTech Connect

    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.

  2. Process for the physical segregation of minerals

    DOEpatents

    Yingling, Jon C.; Ganguli, Rajive

    2004-01-06

    With highly heterogeneous groups or streams of minerals, physical segregation using online quality measurements is an economically important first stage of the mineral beneficiation process. Segregation enables high quality fractions of the stream to bypass processing, such as cleaning operations, thereby reducing the associated costs and avoiding the yield losses inherent in any downstream separation process. The present invention includes various methods for reliably segregating a mineral stream into at least one fraction meeting desired quality specifications while at the same time maximizing yield of that fraction.

  3. World mineral exploration trends and economic issues

    SciTech Connect

    Tilton, J.E.; Eggert, R.G. . Dept. of Mineral Economics); Landsberg, H.H. )

    1988-01-01

    The subjects and methodologies presented in this book vary from the presentation of a heretofore unavailable collection of data on worldwide mineral exploration to case studies of mineral exploration in the developing countries of Botswana and Papua New Guinea to a study of the economic productivity of base metal exploration in Australia and Canada. Some authors concentrate on particular actors or participants in the exploration process, such as major mining companies, while other focus on a particular country such as the Soviet Union, France, or South Africa. Most chapters deal with exploration for nonfuel minerals, and particularly metals, although some take in uranium and coal exploration; oil and gas exploration is specifically excluded.

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

    SciTech Connect

    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.

  5. 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) | DOE PAGES Publisher's Accepted Manuscript: Antiferromagnetic Kondo lattice in the layered compound CePd1-xBi₂ and comparison to the superconductor LaPd1-xBi₂ 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 susceptibility data

  6. 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

  7. Division of Energy and Mineral Resources Management - Projects

    Energy Saver

    ... BIA BIA - - Division of Energy and Mineral Division of Energy and Mineral Resources Management Resources Management 19 19 Nez Perce Nez Perce * * Biodiesel Plant Biodiesel Plant ...

  8. Buckhorn Mineral Wells Pool & Spa Low Temperature Geothermal...

    OpenEI (Open Energy Information) [EERE & EIA]

    Buckhorn Mineral Wells Pool & Spa Low Temperature Geothermal Facility Jump to: navigation, search Name Buckhorn Mineral Wells Pool & Spa Low Temperature Geothermal Facility...

  9. Indian Mineral Leasing Act of 1938 | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Provides for leasing of minerals on tribal lands References IMLA1 United States v. Navajo Nation2 The Indian Mineral Leasing Act of 1938 (IMLA) provides that "unallotted...

  10. Geology and Mineral Deposits of Churchill County, Nevada | Open...

    OpenEI (Open Energy Information) [EERE & EIA]

    Mineral Deposits of Churchill County, Nevada Jump to: navigation, search OpenEI Reference LibraryAdd to library Report: Geology and Mineral Deposits of Churchill County, Nevada...

  11. H. R. S. 182 - Reservation and Disposition of Government Mineral...

    OpenEI (Open Energy Information) [EERE & EIA]

    Mineral Rights (2012). Retrieved from "http:en.openei.orgwindex.php?titleH.R.S.182-ReservationandDispositionofGovernmentMineralRights&oldid801574" ...

  12. Uranium-Bearing Evaporite Mineralization Influencing Plume Persistence...

    Energy.gov [DOE] (indexed site)

    Uranium-Bearing Evaporite Mineralization Influencing Plume Persistence: Literature Review and DOE-LM Site Surveys Uranium-Bearing Evaporite Mineralization Influencing Plume ...

  13. Vietnam National Coal Mineral Industries Group Vinacomin | Open...

    OpenEI (Open Energy Information) [EERE & EIA]

    National Coal Mineral Industries Group Vinacomin Jump to: navigation, search Name: Vietnam National Coal-Mineral Industries Group (Vinacomin) Place: Vietnam Product: Vietnam-based...

  14. Bashfords Hot Mineral Spa Pool & Spa Low Temperature Geothermal...

    OpenEI (Open Energy Information) [EERE & EIA]

    Bashfords Hot Mineral Spa Pool & Spa Low Temperature Geothermal Facility Jump to: navigation, search Name Bashfords Hot Mineral Spa Pool & Spa Low Temperature Geothermal Facility...

  15. ITP Mining: Mining Industry of the Future Mineral Processing...

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    of the Future Mineral Processing Technology Roadmap ITP Mining: Mining Industry of the Future Mineral Processing Technology Roadmap mptroadmap.pdf (293.48 KB) More Documents & ...

  16. Relations Of Ammonium Minerals At Several Hydrothermal Systems...

    OpenEI (Open Energy Information) [EERE & EIA]

    to mineralization. Submicroscopic analysis of ammonium minerals from two mercury- and gold-bearing hot-springs deposits at Ivanhoe, Nevada and McLaughlin, California shows that...

  17. Mineral Leasing Act for Acquired Lands of 1947 | Open Energy...

    OpenEI (Open Energy Information) [EERE & EIA]

    of the Mineral Leasing Act and the authority of the Secretary of the Interior over oil and gas operations to federal "acquired lands." References Mineral Leasing Act for...

  18. Recovery of minerals from US coals

    SciTech Connect

    Vanderborgh, N.E.

    1982-01-01

    Projections show that domestic coal will serve for the majority of energy supplies during the next decades. Thorough chemical cleaning of this coal can be accomplished in long residence time, slurry transport systems to produce high-quality fuel product. Concurrently, mineral recovery from coals will supplement existing ores. This paper describes this concept and given preliminary engineering considerations for mineral recovery during transport operations.

  19. Crystal structure, electronic structure, temperature-dependent optical and scintillation properties of CsCe2Br7

    DOE PAGES [OSTI]

    Wu, Yuntao; Shi, Hongliang; Chakoumakos, Bryan C.; Zhuravleva, Mariya; Du, Mao-Hua; Melcher, Charles L.

    2015-10-05

    CsCe2Br7 is a self-activated inorganic scintillator that shows promising performance, but the understanding of the important structure-property relationships is lacking. In this work, we conduct a comprehensive study on CCsCe2Br7. The crystal structure of CsCe2Br7 is refined using single crystal X-ray study for the first time. It crystallizes into the orthorhombic crystal system with Pmnb space group. Its electronic structure is revealed by Density Functional Theory (DFT) calculations. Two cerium emission centers are identified and the energy barriers related to the thermal quenching to 4f ground states of Ce3+ for these two Ce centers are evaluated. CsCe2Br7 single crystal hasmore » better light yield and energy resolution than CsCe2Cl7, but with an additional slow decay component of 1.7 s. The existence of a deep trap with a depth of 0.9 eV in CsCe2Cl7 contributes to its higher afterglow level in comparison to that of CsCe2Br7. The most possible point defects in CsCe2Cl7 and CsCe2Br7 are proposed by considering the vapour pressure in the growth atmosphere upon melting point.« less

  20. 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

    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.

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

    SciTech Connect

    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.

  2. 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 ...

  3. 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: ...

  4. Chemical stability and Ce doping of LiMgAlF6 neutron scintillator

    DOE PAGES [OSTI]

    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.

  5. Chemical stability and Ce doping of LiMgAlF6 neutron scintillator

    SciTech Connect

    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.

  6. Luminescent down shifting effect of Ce-doped yttrium aluminum garnet thin films on solar cells

    SciTech Connect

    Shao, Guojian; Lou, Chaogang; Kang, Jian; Zhang, Hao

    2015-12-21

    Ce-doped yttrium aluminum garnet (YAG:Ce) thin films as luminescent down shifting (LDS) materials are introduced into the module of crystalline silicon solar cells. The films are deposited by RF magnetron sputtering on the lower surface of the quartz glass. They convert ultraviolet and blue light into yellow light. Experiments show that the introduction of YAG:Ce films improves the conversion efficiency from 18.45% of the cells to 19.27% of the module. The increasing efficiency is attributed to LDS effect of YAG:Ce films and the reduced reflection of short wavelength photons. Two intentionally selected samples with similar reflectivities are used to evaluate roughly the effect of LDS alone on the solar cells, which leads to a relative increase by 2.68% in the conversion efficiency.

  7. 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 ...

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

    SciTech Connect

    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. Pressure tuning of competing magnetic interactions in intermetallic CeFe2

    SciTech Connect

    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.

  10. 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 ...

  11. 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 ...

  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. 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 ...

  14. 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 ...

  15. 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 ...

  16. 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.

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

    DOE PAGES [OSTI]

    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

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

    SciTech Connect

    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.

  19. Antiferromagnetic ordering in the doped Kondo insulator CeRhSb

    SciTech Connect

    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}

  20. Structure and scintillation yield of Ce-doped Al–Ga substituted yttrium garnet

    SciTech Connect

    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 yttrium–aluminum garnet. Luminescence properties at Al/Ga substitution are evaluated.

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

    SciTech Connect

    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.

  2. LOW TEMPERATURE GEOTHERMAL MINERAL RECOVERY PROGRAM | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    LOW TEMPERATURE GEOTHERMAL MINERAL RECOVERY PROGRAM LOW TEMPERATURE GEOTHERMAL MINERAL RECOVERY PROGRAM mineral-webinar.pdf (3.45 MB) More Documents & Publications LOW TEMPERATURE GEOTHERMAL MINERAL RECOVERY PROGRAM 02/11/2014 Geothermal Play Fairway Analysis Geothermal Play Fairway Analysis

  3. Low-Temperature Mineral Recovery Program FOA Selections

    Office of Energy Efficiency and Renewable Energy (EERE)

    Energy Department's geothermal technologies office awarded nine projects in low-temperature and mineral recovery.

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

    SciTech Connect

    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.

  5. MINER{nu}A Test Beam Commissioning

    SciTech Connect

    Higuera, A.; Castorena, J.; Urrutia, Z.; Felix, J.; Zavala, G.

    2009-12-17

    MINER{nu}A Main INjector ExpeRiment {nu}-A is a high-statistic neutrino scattering experiment that will ran in the NuMI Beam Hall at Fermilab. To calibrate the energy response of the MINER{nu}A detector, a beamline is being designed for the MINER{nu}A Test Beam Detector (TBD). The TBD is a replica of the full MINER{nu}A detector at small scale for calibration studies of the main detector. The beamline design consists of the following parts: a copper target, used to generate tertiaries from an incoming secondary beam; a steel collimator for tertiaries, which also serves as a dump for the incoming beam; a time of fight system (scintillator planes); four wire chambers, for angle measurements and tracking; and two dipole magnets, used as an spectrometer. During last October, the first commissioning run of the MINER{nu}A Test Beam took place in the Meson Test Beam Facility at Fermilab. We commissioned the target and collimator of the new tertiary beamline.

  6. Injury experience in metallic mineral mining, 1992

    SciTech Connect

    Not Available

    1994-05-01

    This Mine Safety and Health Administration (MSHA) informational report reviews in detail the occupational injury and illness experience of metallic mineral 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, occupation, and principal type of mineral. 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.

  7. Injury experience in metallic mineral mining, 1991

    SciTech Connect

    Not Available

    1993-10-01

    This Mine Safety and Health Administration (MSHA) informational report reviews in detail the occupational injury and illness experience of metallic mineral 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, occupation, and principal type of mineral. 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.

  8. Injury experience in metallic mineral mining, 1987

    SciTech Connect

    Not Available

    1988-01-01

    This Mine Safety and Health Administration (MSHA) informational report reviews in detail the occupational injury and illness experience of metallic mineral mining in the United States for 1987. Data reported by operators of mining establishments concerning work injuries are summarized by work location, accident classification, part of body injured, nature of injury, occupation, and principal type of mineral. 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., 44 tabs.

  9. Injury experience in metallic mineral mining, 1990

    SciTech Connect

    Not Available

    1991-12-31

    This Mine Safety and Health Administration (MSHA) informational report reviews in detail the occupational injury and illness experience of metallic mineral 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, occupation, and principal type of mineral. 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.

  10. Injury experience in metallic mineral mining, 1988

    SciTech Connect

    Not Available

    1989-01-01

    This Mine Safety and Health Administration (MSHA) informational report reviews in detail the occupational injury and illness experience of metallic mineral mining in the United States of 1988. Data reported by operators of mining establishments concerning work injuries are summarized by work location, accident classification, part of body injured, nature of injury, occupation, and principal type of mineral. 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., 46 refs.

  11. Injury experience in metallic mineral mining, 1990

    SciTech Connect

    Not Available

    1991-01-01

    This Mine Safety and Health Administration (MSHA) informational report reviews in detail the occupational injury and illness experience of metallic mineral 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, occupation, and principal type of mineral. 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.

  12. Injury experience in metallic mineral mining, 1986

    SciTech Connect

    Not Available

    1987-01-01

    This Mine Safety and Health Administration (MSHA) informational report reviews in detail the occupational injury and illness experience of metallic mineral mining in the United States for 1986. Data reported by operators of mining establishments concerning work injuries are summarized by work location, accident classification, part of body injured, natured of injury, occupation, and principal type of mineral. 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., 46 tabs.

  13. Injury experience in metallic mineral mining, 1989

    SciTech Connect

    Not Available

    1990-01-01

    This Mine Safety and Health Administration (MSHA) informational report reviews in detail the occupational injury and illness experience of metallic mineral mining in the 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, occupation, and principal type of mineral. 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., 46 tabs.

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

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

    DOE PAGES [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.; 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

  17. Fischer-Tropsch Synthesis. Reduction Behavior and Catalytic Activity of Fe-Ce Systems

    SciTech Connect

    Perez-Alonso, F.J.; Ojeda, M.; Herranz, T.; Fierro, J.L.G.

    2005-04-26

    Several Fe-Ce catalysts for FT synthesis were prepared following two different methods: coprecipitation from Fe and Ce nitrate solutions and a physical mixture of pure Fe and Ce precursors. The iron phases present in the activated catalysts were identified by XRD and Moessbauer spectroscopy. A good correlation between both techniques was found. The results revealed that the cerium oxide in the samples prepared by coprecipitation produces two effects: (i), stabilization of metastable species (Fe1-xO), and (ii), a decrease in the crystallite size of the iron species upon increasing Ce-contents, as inferred from an increase in superparamagnetic species. The catalysts were tested in CO hydrogenation in a flow reactor. It was found that selectivity towards light olefins increases for the coprecipitated Ce-containing catalysts, whereas CO conversion followed the opposite trend. Since the Fe1-xO phase was detected in these catalysts, it is suggested that the formation of the Fe1-xO phase would be responsible for the drop in catalytic activity.

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

    DOE PAGES [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 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

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

    SciTech Connect

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

    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

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

    SciTech Connect

    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.

  2. Injury experience in metallic mineral mining, 1985

    SciTech Connect

    Not Available

    1987-01-01

    This Mine Safety and Health Administration (MSHA) informational report reviews in detail the occupational injury and illness experience of metallic mineral mining in the United States for 1985. Data reported by operators of mining establishments concerning work injuries are summarized by work location, accident classification, part of body injured, nature of injury, occupation, and principal type of mineral. 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. Data used in compiling this report were reported by operators of metallic mineral mines and preparation plants on a mandatory basis as required under the Federal Mine Safety and Health Act of 1977, Public Law 91-173 as amended by Law 95-164. Since January 1, 1978, operators of mines or preparation plants or both which are subject to the Act have been required under 30 CFR, Part 50, to submit reports of injuries, occupational illnesses, and related data. 3 figs., 46 tabs.

  3. Iron oxyhydroxide mineralization on microbial extracellular polysaccharides

    SciTech Connect

    Chan, Clara S.; Fakra, Sirine C.; Edwards, David C.; Emerson, David; Banfield, Jillian F.

    2010-06-22

    Iron biominerals can form in neutral pH microaerophilic environments where microbes both catalyze iron oxidation and create polymers that localize mineral precipitation. In order to classify the microbial polymers that influence FeOOH mineralogy, we studied the organic and mineral components of biominerals using scanning transmission X-ray microscopy (STXM), micro X-ray fluorescence ({mu}XRF) microscopy, and high-resolution transmission electron microscopy (HRTEM). We focused on iron microbial mat samples from a creek and abandoned mine; these samples are dominated by iron oxyhydroxide-coated structures with sheath, stalk, and filament morphologies. In addition, we characterized the mineralized products of an iron-oxidizing, stalk-forming bacterial culture isolated from the mine. In both natural and cultured samples, microbial polymers were found to be acidic polysaccharides with carboxyl functional groups, strongly spatially correlated with iron oxyhydroxide distribution patterns. Organic fibrils collect FeOOH and control its recrystallization, in some cases resulting in oriented crystals with high aspect ratios. The impact of polymers is particularly pronounced as the materials age. Synthesis experiments designed to mimic the biomineralization processes show that the polysaccharide carboxyl groups bind dissolved iron strongly but release it as mineralization proceeds. Our results suggest that carboxyl groups of acidic polysaccharides are produced by different microorganisms to create a wide range of iron oxyhydroxide biomineral structures. The intimate and potentially long-term association controls the crystal growth, phase, and reactivity of iron oxyhydroxide nanoparticles in natural systems.

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  6. Vortexlike excitations in the heavy-fermion superconductor CeIrIn5

    DOE PAGES [OSTI]

    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

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

    SciTech Connect

    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.

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

    SciTech Connect

    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

  9. Neutron Scattering of CeNi at the SNS-ORNL: A Preliminary Report

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Conference: Neutron Scattering of CeNi at the SNS-ORNL: A Preliminary Report Citation Details In-Document Search Title: Neutron Scattering of CeNi at the SNS-ORNL: A Preliminary Report Authors: Mirmelstein, A V ; Podlesnyak, A ; Kolesnikov, A I ; Saporov, B ; Sefat, A S ; Tobin, J G Publication Date: 2014-04-13 OSTI Identifier: 1132013 Report Number(s): LLNL-PROC-653272 DOE Contract Number: DE-AC52-07NA27344 Resource Type: Conference Resource Relation:

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

    SciTech Connect

    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.

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

    SciTech Connect

    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}

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  16. Molecular Characterization of Bacterial Respiration on Minerals

    SciTech Connect

    Blake, Robert C.

    2013-04-26

    The overall aim of this project was to contribute to our fundamental understanding of proteins and biological processes under extreme environmental conditions. We sought to define the biochemical and physiological mechanisms that underlie biodegradative and other cellular processes in normal, extreme, and engineered environments. Toward that end, we sought to understand the substrate oxidation pathways, the electron transport mechanisms, and the modes of energy conservation employed during respiration by bacteria on soluble iron and insoluble sulfide minerals. In accordance with these general aims, the specific aims were two-fold: To identify, separate, and characterize the extracellular biomolecules necessary for aerobic respiration on iron under strongly acidic conditions; and to elucidate the molecular principles whereby these bacteria recognize and adhere to their insoluble mineral substrates under harsh environmental conditions. The results of these studies were described in a total of nineteen manuscripts. Highlights include the following: 1. The complete genome of Acidithiobacillus ferrooxidans ATCC 23270 (type strain) was sequenced in collaboration with the DOE Joint Genome Institute; 2. Genomic and mass spectrometry-based proteomic methods were used to evaluate gene expression and in situ microbial activity in a low-complexity natural acid mine drainage microbial biofilm community. This was the first effort to successfully analyze a natural community using these techniques; 3. Detailed functional and structural studies were conducted on rusticyanin, an acid-stable electron transfer protein purified from cell-free extracts of At. ferrooxidans. The three-dimensional structure of reduced rusticyanin was determined from a combination of homonuclear proton and heteronuclear 15N- and 13C-edited NMR spectra. Concomitantly, the three-dimensional structure of oxidized rusticyanin was determined by X-ray crystallography to a resolution of 1.9 A by multiwavelength

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

    SciTech Connect

    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}

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

    SciTech Connect

    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}.

  19. Observation of Strong Resonant Behavior in the Inverse Photoelectron Spectroscopy of Ce Oxide

    SciTech Connect

    Tobin, J G; Yu, S W; Chung, B W; Waddill, G D; Damian, E; Duda, L; Nordgren, J

    2009-12-15

    X-ray Emission Spectroscopy (XES) and Resonant Inverse Photoelectron Spectroscopy (RIPES) have been used to investigate the photon emission associated with the Ce3d5/2 and Ce3d3/2 thresholds. Strong resonant behavior has been observed in the RIPES of Ce Oxide near the 5/2 and 3/2 edges. Inverse Photoelectron Spectroscopy (IPES) and its high energy variant, Bremstrahlung Isochromat Spectroscopy (BIS), are powerful techniques that permit a direct interrogation of the low-lying unoccupied electronic structure of a variety of materials. Despite being handicapped by counting rates that are approximately four orders of magnitude less that the corresponding electron spectroscopies (Photoelectron Spectroscopy, PES, and X-ray Photoelectron Spectroscopy, XPS) both IPES and BIS have a long history of important contributions. Over time, an additional variant of this technique has appeared, where the kinetic energy (KE) of the incoming electron and photon energy (hv) of the emitted electron are roughly the same magnitude as the binding energy of a core level of the material in question. Under these circumstances and in analogy to Resonant Photoelectron Spectroscopy, a cross section resonance can occur, giving rise to Resonant Inverse Photoelectron Spectroscopy or RIPES. Here, we report the observation of RIPES in an f electron system, specifically the at the 3d{sub 5/2} and 3d{sub 3/2} thresholds of Ce Oxide. The resonant behavior of the Ce4f structure at the 3d thresholds has been addressed before, including studies of the utilization of the technique as a probe of electron correlation in a variety of Ce compounds. Interestingly, the first RIPES work on rare earths dates back to 1974, although under conditions which left the state of the surface and near surface regions undefined. Although they did not use the more modern terminology of 'RIPES,' it is clear that RIPES was actually first performed in 1974 by Liefeld, Burr and Chamberlain on both La and Ce based materials. In

  20. Detection and Retrieval of Mineral Dust Aerosol Using AERI during...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Detection and Retrieval of Mineral Dust Aerosol Using AERI during the UAE2 Field Campaign: ... A method for detecting and retrieving airborne mineral dust using the surface-based ...

  1. Mineral Recovery Creates Revenue Stream for Geothermal Energy Development

    Office of Energy Efficiency and Renewable Energy (EERE)

    Find out more about Notice to Issue Financial Opportunity Announcement on "Low-Temperature Mineral Recovery Program," a targeted GTO initiative focused on strategic mineral extraction as a path to optimize the value stream of low-to-moderate-tempe

  2. Indian Mineral Development Act of 1982 | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    agreements with DOI approval References Indian Mineral Development Act of 19821 Bureau of Indian Affairs2 The Indian Mineral Development Act of 1982 (IMDA) 25 U.S.C. Secs....

  3. File:03AKDStateNoncompetitiveMineralLeasingProcess.pdf | Open...

    OpenEI (Open Energy Information) [EERE & EIA]

    3AKDStateNoncompetitiveMineralLeasingProcess.pdf Jump to: navigation, search File File history File usage Metadata File:03AKDStateNoncompetitiveMineralLeasingProcess.pdf Size of...

  4. Title 11 Alaska Administrative Code 82 Mineral Leasing Procedures...

    OpenEI (Open Energy Information) [EERE & EIA]

    2 Mineral Leasing Procedures Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- RegulationRegulation: Title 11 Alaska Administrative Code 82 Mineral...

  5. Title 36 CFR 228 Minerals | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Regulation: Title 36 CFR 228 MineralsLegal Abstract Part 228 Minerals under Title 36: Parks, Forests, and Public Property of the U.S. Code of Federal Regulations, current as of...

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

    SciTech Connect

    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.

  7. Superhydrophobic Coating for Evaporative Purification and Minerals

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Extraction - Energy Innovation Portal Energy Storage Energy Storage Early Stage R&D Early Stage R&D Advanced Materials Advanced Materials Find More Like This Return to Search Superhydrophobic Coating for Evaporative Purification and Minerals Extraction Oak Ridge National Laboratory Contact ORNL About This Technology Publications: PDF Document Publication 12-G00204_2744_2400.pdf (845 KB) Technology Marketing SummaryResearchers at ORNL are using their superhydrophobic coating

  8. IEED Energy and Mineral Development Grants

    Energy.gov [DOE]

    The Secretary of the Interior, through the Office of lndian Energy and Economic Development (IEED), is soliciting grant proposals from federally recognized Indian tribes and tribal energy resource development organizations for projects that assess, evaluate, or otherwise promote the processing, use, or development of energy and mineral resources on Indian lands. Grant awards are subject to the availability of funds as appropriated by Congress and allotted to IEED.

  9. H. R. S. 182 - Reservation and Disposition of Government Mineral...

    OpenEI (Open Energy Information) [EERE & EIA]

    (Redirected from Hawaii Revised Statute 182-1, Definitions for Reservation and Disposition of Government Mineral Rights)...

  10. Uranium-Bearing Evaporite Mineralization Influencing Plume Persistence...

    Office of Scientific and Technical Information (OSTI)

    ... Subject: 58 GEOSCIENCES; 54 ENVIRONMENTAL SCIENCES; EVAPORITES; URANIUM; REVIEWS; PLUMES; CHLORIDES; GEOLOGIC DEPOSITS; NUCLEAR FACILITIES; MINERALIZATION; TAILINGS; SITE ...

  11. Uranium-Bearing Evaporite Mineralization Influencing Plume Persistence:

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Literature Review and DOE-LM Site Surveys | Department of Energy Uranium-Bearing Evaporite Mineralization Influencing Plume Persistence: Literature Review and DOE-LM Site Surveys Uranium-Bearing Evaporite Mineralization Influencing Plume Persistence: Literature Review and DOE-LM Site Surveys Uranium-Bearing Evaporite Mineralization Influencing Plume Persistence: Literature Review and DOE-LM Site Surveys Uranium-Bearing Evaporite Mineralization Influencing Plume Persistence: Literature Review

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

    SciTech Connect

    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.}

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

    SciTech Connect

    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.

  14. Influence of Electron Doping on Magnetic Order in CeRu2Al10

    SciTech Connect

    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.

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  17. Tribology of earthmoving, mining, and minerals processing

    SciTech Connect

    Hawk, Jeffrey A.; Wilson, Rick D.

    2001-01-01

    Earthmoving, mining, and minerals processing each involve frequent, and often severe, mechanical interactions between metals, and between metals and abrasive nonmetallic and metallic materials (i.e., mineral bearing ores). The abrasive nature of ores causes significant wear to extracting, handling, and processing equipment. Consequently, wear in earthmoving, mining, and minerals processing operations results in the removal of large amounts of material from the wear surfaces of scraping, digging, and ore processing equipment. From an energy point of view, material wear of this nature is classified as an indirect tribological loss (Imhoff et al., 1985). Additionally, a significant amount of energy is expended to overcome frictional forces in the operation of all earthmoving, mining, and minerals processing machinery (i.e., a direct tribological loss). However, in these particular processes, wear losses are more than five times those of frictional losses. In general, the amount of material lost from a particular component in these operations, before it becomes unserviceable, is far greater than that which can be tolerated in typical metal-to-metal wear situations (e.g., lubricated bearing-shaft wear couples in machinery). Consequently, much of the equipment used in earthmoving, mining, and ore processing makes use of easily replaceable or repairable, and preferably low-cost, wear components. The mechanisms by which metal-to-metal and abrasive wear occurs, and the relationships between material properties and wear behavior, are reasonably well-understood in general terms. However, the specific wear mechanisms/wear material interactions that occur during earthmoving, digging, and the processing of ore are more complex, and depend on the wear material, and on the nature of abrasive, the type of loading, and the environment. As a result of this general knowledge, reliable predictions can be made regarding the performance of particular materials under a range of in

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

    DOE PAGES [OSTI]

    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

  19. 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

    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}.

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

    SciTech Connect

    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.

  1. Minerals yearbook: Mineral industries of Europe and the USSR. Volume 3. 1990 international review

    SciTech Connect

    Not Available

    1990-01-01

    The section of the Minerals Yearbook reviews the minerals industries of 29 countries: the 12 nations of the European Community (Belgium, France, the Federal Republic of Germany (FRG), Italy, Greece, the Netherlands, Denmark/Greenland, Spain, Portugal, Luxembourg, The United Kingdom, and Ireland); 6 of the 7 nations of the European Free Trade Association (Sweden, Norway, Finland, Iceland, Austria, and Switzerland); Malta; the 8 Centrally Planned Economies of Eastern Europe (the German Democratic Republic (GDR), Poland, Yugoslavia, Albania, Hungary, Czechoslovakia, Romania, and Bulgaria); and the USSR.

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

    SciTech Connect

    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.

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

    DOE PAGES [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 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.

  4. SkyMine Carbon Mineralization Pilot Project

    SciTech Connect

    Christenson, Norm; Walters, Jerel

    2014-12-31

    This Topical Report addresses accomplishments achieved during Phase 2b of the SkyMine® Carbon Mineralization Pilot Project. The primary objectives of this project are to design, construct, and operate a system to capture CO2 from a slipstream of flue gas from a commercial coal-fired cement kiln, convert that CO2 to products having commercial value (i.e., beneficial use), show the economic viability of the CO2 capture and conversion process, and thereby advance the technology to the point of readiness for commercial scale demonstration and deployment. The overall process is carbon negative, resulting in mineralization of CO2 that would otherwise be released into the atmosphere. The project will also substantiate market opportunities for the technology by sales of chemicals into existing markets, and identify opportunities to improve technology performance and reduce costs at the commercial scale. The project is being conducted in two phases. The primary objectives of Phase 1 were to evaluate proven SkyMine® process chemistry for commercial pilot-scale operation and complete the preliminary design for the pilot plant to be built and operated in Phase 2, complete a NEPA evaluation, and develop a comprehensive carbon life cycle analysis. The objective of Phase 2b was to build the pilot plant to be operated and tested in Phase 2c.

  5. New mineral occurrences and mineralization processes: Wuda coal-fire gas vents of Inner Mongolia

    SciTech Connect

    Stracher, G.B.; Prakash, A.; Schroeder, P.; McCormack, J.; Zhang, X.M.; Van Dijk, P.; Blake, D.

    2005-12-01

    Five unique mineral assemblages that include the sulfates millosevichite, alunogen, anhydrite, tschermigite, coquimbite, voltaite, and godovikovite, as well as the halide salammoniac and an unidentified phase, according to X-ray diffraction and EDS data, were found as encrustations on quartzofeldspathic sand and sandstone adjacent to coal-fire gas vents associated with underground coal fires in the Wuda coalfield of Inner Mongolia. The mineral assemblage of alunogen, coquimbite, voltaite, and the unidentified phase collected front the same gas vent, is documented for the first time. Observations suggest that the sulfates millosevichite, alunogen, coquimbite, voltaite, godovikovite, and the unidentified phase, crystallized in response to a complex sequence of processes that include condensation, hydrothermal alteration, crystallization from solution, fluctuating vent temperatures, boiling, and dehydration reactions, whereas the halide salammoniac crystallized during the sublimation of coal-fire gas. Tschermigite and anhydrite formed by the reaction of coal-fire gas with quartzofelds pathic rock or by hydrothermal alteration of this rock and crystallization from an acid-rich aqueous solution. These minerals have potentially important environmental significance and may be vectors for the transmission of toxins. Coal fires also provide insight for the recognition in the geologic record of preserved mineral assemblages that are diagnostic of ancient fires.

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

    DOE PAGES [OSTI]

    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

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

    SciTech Connect

    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}

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

    SciTech Connect

    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.

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

    DOE PAGES [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 amore » heavy metal. The experiment therefore shows how quasiparticle behavior is changed by the close proximity of quantum criticality.« less

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  12. 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:

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  15. Selective flotation of phosphate minerals with hydroxamate collectors

    DOEpatents

    Miller, Jan D.; Wang, Xuming; Li, Minhua

    2002-01-01

    A method is disclosed for separating phosphate minerals from a mineral mixture, particularly from high-dolomite containing phosphate ores. The method involves conditioning the mineral mixture by contacting in an aqueous in environment with a collector in an amount sufficient for promoting flotation of phosphate minerals. The collector is a hydroxamate compound of the formula; ##STR1## wherein R is generally hydrophobic and chosen such that the collector has solubility or dispersion properties it can be distributed in the mineral mixture, typically an alkyl, aryl, or alkylaryl group having 6 to 18 carbon atoms. M is a cation, typically hydrogen, an alkali metal or an alkaline earth metal. Preferably, the collector also comprises an alcohol of the formula, R'--OH wherein R' is generally hydrophobic and chosen such that the collector has solubility or dispersion properties so that it can be distributed in the mineral mixture, typically an alkyl, aryl, or alkylaryl group having 6 to 18 carbon atoms.

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

    DOE PAGES [OSTI]

    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

  17. Complex magnetism and strong electronic correlations in Ce2PdGe3

    DOE PAGES [OSTI]

    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

  18. Influence of Electron Doping on Magnetic Order in CeRu2Al10

    DOE PAGES [OSTI]

    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

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

    DOE PAGES [OSTI]

    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

  20. An Update on Improvements to NiCE Support for PROTEUS

    SciTech Connect

    Bennett, Andrew; McCaskey, Alexander J.; Billings, Jay Jay

    2015-09-01

    The Department of Energy Office of Nuclear Energy s Nuclear Energy Advanced Modeling and Simulation (NEAMS) program has supported the development of the NEAMS Integrated Computational Environment (NiCE), a modeling and simulation workflow environment that provides services and plugins to facilitate tasks such as code execution, model input construction, visualization, and data analysis. This report details the developement of workflows for the reactor core neutronics application, PROTEUS. This advanced neutronics application (primarily developed at Argonne National Laboratory) aims to improve nuclear reactor design and analysis by providing an extensible and massively parallel, finite-element solver for current and advanced reactor fuel neutronics modeling. The integration of PROTEUS-specific tools into NiCE is intended to make the advanced capabilities that PROTEUS provides more accessible to the nuclear energy research and development community. This report will detail the work done to improve existing PROTEUS workflow support in NiCE. We will demonstrate and discuss these improvements, including the development of flexible IO services, an improved interface for input generation, and the addition of advanced Fortran development tools natively in the platform.

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

    SciTech Connect

    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.

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

    DOE PAGES [OSTI]

    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

  3. CMI Course Inventory: Mineral Economics and Business | Critical Materials

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    Institute Mineral Economics and Business Mineral Economics and Business Of the six CMI Team members that are educational institutions, two offer courses in Mineral Economics and Business. These are Colorado School of Mines and Brown University. The following links go to the class list on the CMI page for that school. Colorado School of Mines offers a major in these areas At Brown University, the Institute of Environment and Society offers several courses on economics and policy CMI Education

  4. Uranium-Bearing Evaporite Mineralization Influencing Plume Persistence.

    Office of Scientific and Technical Information (OSTI)

    Literature Review and DOE-LM Site Surveys (Technical Report) | SciTech Connect Uranium-Bearing Evaporite Mineralization Influencing Plume Persistence. Literature Review and DOE-LM Site Surveys Citation Details In-Document Search Title: Uranium-Bearing Evaporite Mineralization Influencing Plume Persistence. Literature Review and DOE-LM Site Surveys This report on evaporite mineralization was completed as an Ancillary Work Plan for the Applied Studies and Technology program under the U.S.

  5. Emission properties and back-bombardment for CeB{sub 6} compared to LaB{sub 6}

    SciTech Connect

    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.

  6. Respiratory disease in Utah coal miners

    SciTech Connect

    Rom, W.N.; Kanner, R.E.; Renzetti, A.D. Jr.; Shigeoka, J.W.; Barkman, H.W.; Nichols, M.; Turner, W.A.; Coleman, M.; Wright, W.E.

    1981-04-01

    Two hundred forty-two Utah underground coal miners volunteered to participate in a respiratory disease study. They were an older group (mean, 56 years of age) and had spent a mean of 29 years in the coal-mining industry. The prevalence of chronic bronchitis was 57%, and that of coal worker's pneumoconiosis, 25%; only one worker had progressive massive fibrosis. Significant impairment of pulmonary function was found among those with a history of cigarette smoking. Chronic bronchitis or coal worker's penumoconiosis among nonsmokers did not impair pulmonary function. There was a significant association among the nonsmokers between increasing exposure to coal dust and coal worker's pneumoconiosis, but not for changes in pulmonary function. Coal mine dust had a significant influence in causing the symptom complex of chronic cough and sputum production, and coal worker's pneumoconiosis.

  7. Respiratory disease in Utah coal miners

    SciTech Connect

    Rom, W.N.; Kanner, R.E.; Renzetti, A.D. Jr.; Shigeoka, J.W.; Barkman, H.W.; Nichols, M.; Turner, W.A.; Coleman, M.; Wright, W.E.

    1981-04-01

    Two hundred forty-two Utah underground coal miners volunteered to participate in a respiratory disease study. They were an older group (mean, 56 years of age) and had spent a mean of 29 years in the coal-mining industry. The prevalence of chronic bronchitis was 57%, and that of coal worker's pneumoconiosis, 25%; only one worker had progressive massive fibrosis. Significant impairment of pulmonary function was found among those with a history of cigarette smoking. Chronic bronchitis or coal worker's pneumoconiosis among nonsmokers did not impair pulmonary function. There was a significant association among the nonsmokers between increasing exposure to coal dust and coal worker's pneumoconiosis, but not for changes in pulmonary function. Coal mine dust had a significant influence in causing the symptom complex of chronic cough and sputum production, and coal worker's pneumoconiosis.

  8. Molecular Simulation of Carbon Dioxide, Brine, and Clay Mineral...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Molecular Simulation of Carbon Dioxide, Brine, and Clay Mineral Citation Details In-Document Search Title: Molecular Simulation of Carbon Dioxide, Brine, and Clay ...

  9. Molecular Simulation of Carbon Dioxide Brine and Clay Mineral...

    Office of Scientific and Technical Information (OSTI)

    of Carbon Dioxide Brine and Clay Mineral Interactions and Determination of Contact Angles. Citation Details In-Document Search Title: Molecular Simulation of Carbon Dioxide ...

  10. National Mineral Development Corporation Ltd NMDC | Open Energy...

    OpenEI (Open Energy Information) [EERE & EIA]

    Corporation Ltd NMDC Jump to: navigation, search Name: National Mineral Development Corporation Ltd. (NMDC) Place: Hyderabad, Andhra Pradesh, India Zip: 500028 Sector: Solar, Wind...

  11. Mining and Minerals Policy Act of 1970 | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Act, this statute encompasses both hard rock mining and oil and gas and established modern federal policy regarding mineral resources in the United States. The Act articulates a...

  12. Division of Energy and Mineral Development | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    in Lakewood, Colorado. The Division assists Tribes with the exploration, development and management of their energy and mineral resources to create sustainable economies for...

  13. Mineral Association Changes the Secondary Structure and Dynamics...

    Office of Scientific and Technical Information (OSTI)

    materials.1 The structure of these proteins is often implicated in the control of the mineral properties, however very little structural data is available for the bulk of ...

  14. Cooperative Reorganization of Mineral and Template during Directed...

    Office of Scientific and Technical Information (OSTI)

    prepared from organic thiol molecules on metal substrates are known to exert substantial influence over mineralization and, as such, provide model systems for investigating the...

  15. Clay Minerals Related To The Hydrothermal Activity Of The Bouillante...

    OpenEI (Open Energy Information) [EERE & EIA]

    Minerals Related To The Hydrothermal Activity Of The Bouillante Geothermal Field (Guadeloupe) Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article:...

  16. Buckhorn Mineral Wells Space Heating Low Temperature Geothermal...

    OpenEI (Open Energy Information) [EERE & EIA]

    Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Buckhorn Mineral Wells Space Heating Low Temperature Geothermal Facility Facility Buckhorn...

  17. Stewart Mineral Springs Pool & Spa Low Temperature Geothermal...

    OpenEI (Open Energy Information) [EERE & EIA]

    Pool & Spa Low Temperature Geothermal Facility Jump to: navigation, search Name Stewart Mineral Springs Pool & Spa Low Temperature Geothermal Facility Facility Stewart...

  18. Hyperspectral Mineral Mapping In Support Of Geothermal Exploration...

    OpenEI (Open Energy Information) [EERE & EIA]

    CA and Dixie Valley, NV, USA Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Hyperspectral Mineral Mapping In Support Of Geothermal...

  19. Astoria Mineral Hot Springs Pool & Spa Low Temperature Geothermal...

    OpenEI (Open Energy Information) [EERE & EIA]

    Astoria Mineral Hot Springs Sector Geothermal energy Type Pool and Spa Location Jackson, Wyoming Coordinates 43.4799291, -110.7624282 Show Map Loading map......

  20. Radioactive Mineral Occurences in Nevada | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Radioactive Mineral Occurences in Nevada Abstract Abstract unavailable. Author Larry J. Garside Organization Nevada Bureau of Mines and Geology Published Nevada Bureau of...

  1. Hawaii Revised Statute 523A-2, Definition of Mineral Resources...

    OpenEI (Open Energy Information) [EERE & EIA]

    Not provided DOI Not Provided Check for DOI availability: http:crossref.org Online Internet link for Hawaii Revised Statute 523A-2, Definition of Mineral Resources Citation...

  2. Thermally Speciated Mercury in Mineral Exploration | Open Energy...

    OpenEI (Open Energy Information) [EERE & EIA]

    Speciated Mercury in Mineral Exploration Abstract Abstract unavailable. Author S.C. Smith Conference IGES; Dublin, CA; 20030901 Published IGES, 2003 DOI Not Provided Check...

  3. Mineral County, West Virginia: Energy Resources | Open Energy...

    OpenEI (Open Energy Information) [EERE & EIA]

    West Virginia Keyser, West Virginia Piedmont, West Virginia Ridgeley, West Virginia Wiley Ford, West Virginia Retrieved from "http:en.openei.orgwindex.php?titleMineralCou...

  4. An active atmospheric methane sink in high Arctic mineral cryosols...

    Office of Scientific and Technical Information (OSTI)

    conditions coupled with -omics analysis indicate (1) mineral cryosols in the Canadian high Arctic contain atmospheric CH-oxidizing bacteria; (2) the atmospheric CH uptake ...

  5. Mineral Recovery Creates Revenue Stream for Geothermal Energy...

    Energy.gov [DOE] (indexed site)

    produced from the Earth's subsurface by geothermal and other energy or mining projects. ... that these minerals could be found in fluids produced by oil, gas or mining operations. ...

  6. Oxygen And Carbon Isotope Ratios Of Hydrothermal Minerals From...

    OpenEI (Open Energy Information) [EERE & EIA]

    Oxygen And Carbon Isotope Ratios Of Hydrothermal Minerals From Yellowstone Drill Cores Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Oxygen...

  7. Discovery of bridgmanite, the most abundant mineral in Earth...

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Search Results Journal Article: Discovery of bridgmanite, the most abundant mineral in Earth, in a shocked meteorite Citation Details In-Document Search Title: ...

  8. Are mineral investments by energy companies on the ebb

    SciTech Connect

    Prast, W.G.

    1984-01-01

    Despite differences between the most recent round of acquisitions and previous minerals investments by the petroleum industry, the current trend of takeovers builds upon the history of oil's involvement in mining. In particular, takeovers continue to concentrate on uranium, coal, and copper. A number of petroleum firms also have obtained gold, silver, molybdenum, nickel, and other minerals assets. There is no discernible pattern to oil industry ownership of these incidental holdings, the markets for which are not much affected by the activities of petroleum companies. The vast bulk of the minerals investments of oil producers are in the mineral fuels and copper. 5 tables.

  9. Mineral Leasing Act of 1920 | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Leasing Act established the authority of the Secretary of the Interior to oversee oil and gas operations on federal land. References Federal Oil and Gas Statutes1 Mineral...

  10. Diagenesis and clay mineral formation at Gale Crater, Mars (Journal...

    Office of Scientific and Technical Information (OSTI)

    On the basis of the observed host rock and alteration minerals, we present results of equilibrium thermochemical modeling of the Sheepbed mudstones of Yellowknife Bay in order to ...

  11. Australasian Code for Reporting of Exploration Results, Mineral...

    OpenEI (Open Energy Information) [EERE & EIA]

    (JORC) Published The Joint Ore Reserves Committee of The Australasian Institute of Mining and Metallurgy, Australian Institute of Geoscientists, and Minerals Council of...

  12. Investigation of chemical composition and crystal structure in sintered Ce{sub 15}Nd{sub 15}Fe{sub bal}B{sub 1} magnet

    SciTech Connect

    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.

  13. Effect of oxygen vacancy on half metallicity in Ni-doped CeO{sub 2} diluted magnetic semiconductor

    SciTech Connect

    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.

  14. Kondo behavior, ferromagnetic correlations, and crystal fields in the heavy Fermion compounds Ce3X (X=In, Sn)

    SciTech Connect

    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.

  15. Soft chemistry synthesis of high-crystalline orthogermanate CeGeO{sub 4}: A new photocatalyst

    SciTech Connect

    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.

  16. High thermoelectric performance of In, Yb, Ce multiple filled CoSb{sub 3} based skutterudite compounds

    SciTech Connect

    Ballikaya, Sedat; 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

  17. Mineral resources and mineral resource potential of the Panamint Dunes Wilderness Study Area, Inyo County, California

    SciTech Connect

    Kennedy, G.L.; Kilburn, J.E.; Conrad, J.E.; Leszcykowski, A.M.

    1984-01-01

    This report presents the results of a mineral survey of the Panamint Dunes Wilderness Study Area (CDCA-127), California Desert Conservation Area, Inyo County, California. The Panamint Dunes Wilderness Study Area has an identified volcanic cinder resource and few areas with mineral resource potential. Hydrothermal deposits of lead-zinc-silver occur in veins and small replacement bodies along and near the Lemoigne thrust fault on the eastern side of the wilderness study area. Two workings, the Big Four mine with 35,000 tons of inferred subeconomic lead-zinc-silver resources and a moderate potential for additional resources, and the Apple 1 claim with low potential for lead-zinc-silver resources, are surrounded by the study area but are specifically excluded from it. A low resource potential for lead-zinc-silver is assigned to other exposures along the Lemoigne thrust, although metallic minerals were not detected at these places. The Green Quartz prospect, located near the northern tip of the study area, has low resource potential for copper in quartz pegmatities in quartz monzonite of the Hunter Mountain batholith. Nonmetallic mineral resources consist of volcanic cinders and quartz sand. An estimated 900,000 tons of inferred cinder reserves are present at Cal Trans borrow pit MS 242, on the southern margin of the study area. The Panamint Valley dune field, encompassing 480 acres in the north-central part of the study area, has only low resource potential for silica because of impurities. Other sources of silica and outside the study area are of both higher purity and closer to possible markets. 19 refs., 2 figs., 1 tab.

  18. 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

    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.}

  19. Kondo-lattice behavior and multiple characteristic temperatures in CeIr{sub 2}Ge{sub 2}

    SciTech Connect

    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}

  20. Surface-structure sensitivity of CeO2 nanocrystals in photocatalysis and enhancing the reactivity with nanogold

    SciTech Connect

    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.

  1. Surface-structure sensitivity of CeO2 nanocrystals in photocatalysis and enhancing the reactivity with nanogold

    DOE PAGES [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 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

  2. Integrating Steel Production with Mineral Carbon Sequestration

    SciTech Connect

    Klaus Lackner; Paul Doby; Tuncel Yegulalp; Samuel Krevor; Christopher Graves

    2008-05-01

    The objectives of the project were (i) to develop a combination iron oxide production and carbon sequestration plant that will use serpentine ores as the source of iron and the extraction tailings as the storage element for CO2 disposal, (ii) the identification of locations within the US where this process may be implemented and (iii) to create a standardized process to characterize the serpentine deposits in terms of carbon disposal capacity and iron and steel production capacity. The first objective was not accomplished. The research failed to identify a technique to accelerate direct aqueous mineral carbonation, the limiting step in the integration of steel production and carbon sequestration. Objective (ii) was accomplished. It was found that the sequestration potential of the ultramafic resource surfaces in the US and Puerto Rico is approximately 4,647 Gt of CO2 or over 500 years of current US production of CO2. Lastly, a computer model was developed to investigate the impact of various system parameters (recoveries and efficiencies and capacities of different system components) and serpentinite quality as well as incorporation of CO2 from sources outside the steel industry.

  3. SkyMine Carbon Mineralization Pilot Project

    SciTech Connect

    Joe Jones; Clive Barton; Mark Clayton; Al Yablonsky; David Legere

    2010-09-30

    This Topical Report addresses accomplishments achieved during Phase 1 of the SkyMine{reg_sign} Carbon Mineralization Pilot Project. The primary objectives of this project are to design, construct, and operate a system to capture CO{sub 2} from a slipstream of flue gas from a commercial coal-fired cement kiln, convert that CO{sub 2} to products having commercial value (i.e., beneficial use), show the economic viability of the CO{sub 2} capture and conversion process, and thereby advance the technology to a point of readiness for commercial scale demonstration and proliferation. The project will also substantiate market opportunities for the technology by sales of chemicals into existing markets, and identify opportunities to improve technology performance and reduce costs at commercial scale. The primary objectives of Phase 1 of the project were to elaborate proven SkyMine{reg_sign} process chemistry to commercial pilot-scale operation and complete the preliminary design ('Reference Plant Design') for the pilot plant to be built and operated in Phase 2. Additionally, during Phase 1, information necessary to inform a DOE determination regarding NEPA requirements for the project was developed, and a comprehensive carbon lifecycle analysis was completed. These items were included in the formal application for funding under Phase 2. All Phase 1 objectives were successfully met on schedule and within budget.

  4. 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

    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.

  5. Optical properties of {gamma}- and {alpha}-Ce by spectroscopic ellipsometry

    SciTech Connect

    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}.

  6. Disorder and size effects on Kondo interactions and magneticcorrelations in CePt2 nanoscrystals

    SciTech Connect

    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.

  7. Nanostructured LaF{sub 3}:Ce Quantum Dot Nuclear Radiation Detector

    SciTech Connect

    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.

  8. High-pressure, transport, and thermodynamic properties of CeTe3

    SciTech Connect

    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.

  9. Analysis of FEL-based CeC amplification at high gain limit

    SciTech Connect

    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.

  10. 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.

  11. Chemically Accelerated Carbon Mineralization: Chemical and Biological Catalytic Enhancement of Weathering of Silicate Minerals as Novel Carbon Capture and Storage

    SciTech Connect

    2010-07-01

    IMPACCT Project: Columbia University is developing a process to pull CO2 out of the exhaust gas of coal-fired power plants and turn it into a solid that can be easily and safely transported, stored above ground, or integrated into value-added products (e.g. paper filler, plastic filler, construction materials, etc.). In nature, the reaction of CO2 with various minerals over long periods of time will yield a solid carbonate—this process is known as carbon mineralization. The use of carbon mineralization as a CO2 capture and storage method is limited by the speeds at which these minerals can be dissolved and CO2 can be hydrated. To facilitate this, Columbia University is using a unique process and a combination of chemical catalysts which increase the mineral dissolution rate, and the enzymatic catalyst carbonic anhydrase which speeds up the hydration of CO2.

  12. The estimation of the number of underground coal miners and the annual dose to coal miners in China

    SciTech Connect

    Liu, F.D.; Pan, Z.Q.; Liu, S.L.; Chen, L.; Ma, J.Z.; Yang, M.L.; Wang, N.P.

    2007-08-15

    This paper introduces an estimation method for the number of underground coal miners and the annual dose to coal miners in China. It shows that there are about 6 million underground miners at present and the proportion is about 1, 1 and 4 million for national key coal mines, state-owned local coal mines, and township and private-ownership coal mines, respectively. The collective dose is about 1.65 X 10{sup 4} person-Sv y{sup -1}, of which township and private-ownership coal mines contribute about 91%. This paper also points out that the 2000 UNSCEAR report gives the number of miners of coal production and their collective dose, which are underestimated greatly because the report only includes the number of underground miners in national key coal mines, which only accounts for 1/6 of the workers all working under the best ventilation conditions in China.

  13. Pulse studies to decipher the role of surface morphology in CuO/CeO₂ nanocatalysts for the water gas shift reaction

    DOE PAGES [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), 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

  14. Pulse studies to decipher the role of surface morphology in CuO/CeO₂ nanocatalysts for the water gas shift reaction

    SciTech Connect

    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).

  15. Assessment of industrial minerals and rocks in the controlled area

    SciTech Connect

    Castor, S.B.; Lock, D.E.

    1996-08-01

    Yucca Mountain in Nye County, Nevada, is a potential site for a permanent repository for high-level nuclear waste in Miocene ash flow tuff. The Yucca Mountain controlled area occupies approximately 98 km{sup 2} that includes the potential repository site. The Yucca Mountain controlled area is located within the southwestern Nevada volcanic field, a large area of Miocene volcanism that includes at least four major calderas or cauldrons. It is sited on a remnant of a Neogene volcanic plateau that was centered around the Timber Mountain caldera complex. The Yucca Mountain region contains many occurrences of valuable or potentially valuable industrial minerals, including deposits with past or current production of construction aggregate, borate minerals, clay, building stone, fluorspar, silicate, and zeolites. The existence of these deposits in the region and the occurrence of certain mineral materials at Yucca Mountain, indicate that the controlled area may have potential for industrial mineral and rock deposits. Consideration of the industrial mineral potential within the Yucca Mountain controlled area is mainly based on petrographic and lithologic studies of samples from drill holes in Yucca Mountain. Clay minerals, zeolites, fluorite, and barite, as minerals that are produced economically in Nevada, have been identified in samples from drill holes in Yucca Mountain.

  16. Nickel deficiency in RENi2-xP2 (RE=La, Ce, Pr). Combined crystallographic and physical property studies

    SciTech Connect

    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.

  17. Weak hybridization and isolated localized magnetic moments in the compounds CeT2Cd20 (T = Ni, Pd)

    DOE PAGES [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;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

  18. Impact of antitrust enforcement on the Country's minerals posture

    SciTech Connect

    Not Available

    1981-10-07

    This review found that there have not been a significant number of nonfuel-minerals-industry-related antitrust cases litigated at FTC or Justice over the last several years. In addition, officials interviewed in the nonfuel minerals industries generally do not view antitrust enforcement as a serious obstacle to their activities. The Department of Justice and FTC's Bureau of Competition comments on this report are included in enclosure II. Enclosure I presents a background discussion on antitrust enforcement, followed by detailed findings and conclusions. Enclosure III summarizes several antitrust investigations and cases cited by minerals industry spokesmen as examples of antitrust problems. (PSB)

  19. Electronic structure of the heavy-fermion caged compound Ce?Pd??X? (X = Si, Ge) studied by density functional theory and photoelectron spectroscopy

    DOE PAGES [OSTI]

    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

  20. Theoretical Study of Trimethylacetic Acid Adsorption on CeO 2 (111) Surface

    DOE PAGES [OSTI]

    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

  1. 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 PAGES [OSTI]

    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

  2. A NOVEL APPROACH TO MINERAL CARBONATION: ENHANCING CARBONATION WHILE AVOIDING MINERAL PRETREATMENT PROCESS COST

    SciTech Connect

    Michael J. McKelvy; Andrew V.G. Chizmeshya; Kyle Squires; Ray W. Carpenter; Hamadallah Bearat

    2005-10-01

    Known fossil fuel reserves, especially coal, can support global energy demands for centuries to come, if the environmental problems associated with CO{sub 2} emissions can be overcome. Unlike other CO{sub 2} sequestration candidate technologies that propose long-term storage, mineral sequestration provides permanent disposal by forming geologically stable mineral carbonates. Carbonation of the widely occurring mineral olivine (e.g., forsterite, Mg{sub 2}SiO{sub 4}) is a large-scale sequestration process candidate for regional implementation, which converts CO{sub 2} into the environmentally benign mineral magnesite (MgCO{sub 3}). The primary goal is cost-competitive process development. As the process is exothermic, it inherently offers low-cost potential. Enhancing carbonation reactivity is key to economic viability. Recent studies at the U.S. DOE Albany Research Center have established that aqueous-solution carbonation using supercritical CO{sub 2} is a promising process; even without olivine activation, 30-50% carbonation has been achieved in an hour. Mechanical activation (e.g., attrition) has accelerated the carbonation process to an industrial timescale (i.e., near completion in less than an hour), at reduced pressure and temperature. However, the activation cost is too high to be economical and lower cost pretreatment options are needed. Herein, we report our first year progress in exploring a novel approach that offers the potential to substantially enhance carbonation reactivity while bypassing pretreatment activation. We have discovered that robust silica-rich passivating layers form on the olivine surface during carbonation. As carbonation proceeds, these passivating layers thicken, fracture and eventually exfoliate, exposing fresh olivine surfaces during rapidly-stirred/circulating carbonation. We are exploring the mechanisms that govern carbonation reactivity and the impact that (1) modeling/controlling the slurry fluid-flow conditions, (2) varying the

  3. Influence of solvent on the morphology and photocatalytic properties of ZnS decorated CeO{sub 2} nanoparticles

    SciTech Connect

    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.

  4. Temperature Dependence of the Kondo Resonance and Its Satellites in CeCu{sub 2}Si{sub 2}

    SciTech Connect

    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 .

  5. Selectivity loss of Pt/CeO{sub 2} PROX catalysts at low CO concentrations: mechanism and active site study.

    SciTech Connect

    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.

  6. Update on the CeC PoP 704 MHz 5-cell cavity cryomodule design and fabrication

    SciTech Connect

    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.

  7. Removal of mineral matter including pyrite from coal

    DOEpatents

    Reggel, Leslie; Raymond, Raphael; Blaustein, Bernard D.

    1976-11-23

    Mineral matter, including pyrite, is removed from coal by treatment of the coal with aqueous alkali at a temperature of about 175.degree. to 350.degree. C, followed by acidification with strong acid.

  8. Iron speciation in minerals and glasses probed by M [subscript...

    Office of Scientific and Technical Information (OSTI)

    Title: Iron speciation in minerals and glasses probed by M subscript 23 -edge X-ray Raman scattering spectroscopy Authors: Nyrow, A. ; Sternemann, C. ; Wilke, M. ; Gordon, R. A. ...

  9. DOE - Office of Legacy Management -- Foote Mineral Co - PA 27

    Office of Legacy Management (LM)

    PA.27-1 - MemorandumChecklist; C. Young to the File; Subject: Elimination Recommendation of Foote Mineral Company; December 7, 1987 PA.27-2 - AEC Memorandum; Pearson to Reactor ...

  10. Mercury Contents of Natural Thermal and Mineral Fluids, In- U...

    OpenEI (Open Energy Information) [EERE & EIA]

    Paper 713 Jump to: navigation, search OpenEI Reference LibraryAdd to library Book Section: Mercury Contents of Natural Thermal and Mineral Fluids, In- U.S. Geological...

  11. Hyperspectral Mineral Mapping In Support Of Geothermal Exploration...

    OpenEI (Open Energy Information) [EERE & EIA]

    Ca And Dixie Valley, Nv, Usa Jump to: navigation, search OpenEI Reference LibraryAdd to library Book: Hyperspectral Mineral Mapping In Support Of Geothermal Exploration- Examples...

  12. A Review Of Water Contents Of Nominally Anhydrous Natural Minerals...

    OpenEI (Open Energy Information) [EERE & EIA]

    Of Water Contents Of Nominally Anhydrous Natural Minerals In The Mantles Of Earth, Mars And The Moon Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal...

  13. Evolution of a Mineralized Geothermal System, Valles Caldera...

    OpenEI (Open Energy Information) [EERE & EIA]

    Journal Article: Evolution of a Mineralized Geothermal System, Valles Caldera, New Mexico Abstract The 20-km-diam Valles caldera formed at 1.13 Ma and had continuous...

  14. ORS 516 - Department of Geology and Mineral Industries | Open...

    OpenEI (Open Energy Information) [EERE & EIA]

    6 - Department of Geology and Mineral Industries Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: ORS 516 - Department of Geology...

  15. H.R.S. 182-1 - Reservation and Disposition of Government Mineral...

    OpenEI (Open Energy Information) [EERE & EIA]

    Government Mineral Rights, DefinitionsLegal Abstract Hawaii statute governing the administration of government mineral rights, including rights for geothermal resources. Published...

  16. Fundamental study of CO2-H2O-mineral interactions for carbon...

    Office of Scientific and Technical Information (OSTI)

    sequestration, with emphasis on the nature of the supercritical fluid-mineral interface. ... sequestration, with emphasis on the nature of the supercritical fluid-mineral interface. ...

  17. ITP Mining: Mining Industry of the Future Mineral Processing Technology

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Roadmap | Department of Energy of the Future Mineral Processing Technology Roadmap ITP Mining: Mining Industry of the Future Mineral Processing Technology Roadmap mptroadmap.pdf (293.48 KB) More Documents & Publications ITP Mining: Mining Industry Roadmap for Crosscutting Technologies ITP Mining: Water Use in Industries of the Future: Mining Industry ITP Mining: Energy and Environmental Profile of the U.S. Mining Industry

  18. Inducing Mineral Precipitation in Groundwater by Addition of Phosphate

    SciTech Connect

    Karen E. Wright; Yoshiko Fujita; Thomas Hartmann; Mark Conrad

    2011-10-01

    Induced precipitation of phosphate minerals to scavenge trace metals and radionuclides from groundwater is a potential remediation approach for contaminated aquifers. Phosphate minerals can sequester trace elements by primary mineral formation, solid solution formation and/or adsorption, and they are poorly soluble under many environmental conditions, making them attractive for long-term sustainable remediation. The success of such engineered schemes will depend on the particular mineral phases generated, their rates of formation, and their long term stability. The purpose of this study was to examine the precipitation of calcium phosphate minerals under conditions representative of a natural groundwater. Because microorganisms are present in groundwater, and because some proposed schemes for induced phosphate mineral precipitation rely on the stimulation of native groundwater populations, we also tested the effect of bacterial cells (initial densities of 105 and 107 ml-1) within the precipitation medium. We also tested the effect of a trace mixture of propionic, isovaleric, formic and butyric acids (total concentration 0.035 mM). The experiments showed that the general progression of mineral precipitation was similar under all of the conditions, with initial formation of amorphous calcium carbonate, and transformation to poorly crystalline hydroxyapatite (HAP) by the end of the week-long experiments. The presence of the bacterial cells appeared to delay precipitation, although by the end of 7 days the overall extent of precipitation was similar for all of the treatments. The stoichiometry of the final precipitates as well as results of Rietveld refinement of x-ray diffraction data indicated that the treatments including organic acids and bacterial cells resulted in increased distortion of the HAP crystal lattice, with the higher concentration of cells resulting in the greatest distortion. Uptake of Sr into the phosphate minerals was decreased in the treatments

  19. 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

  20. Unusual Kondo-hole effect and crystal-field frustration in Nd-doped CeRhIn

    Office of Scientific and Technical Information (OSTI)

    5 (Journal Article) | DOE PAGES Publisher's Accepted Manuscript: Unusual Kondo-hole effect and crystal-field frustration in Nd-doped CeRhIn 5 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 Review B

  1. 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

  2. Crystal structure, electronic structure, temperature-dependent optical and scintillation properties of CsCe2Br7

    SciTech Connect

    Wu, Yuntao; Shi, Hongliang; Chakoumakos, Bryan C.; Zhuravleva, Mariya; Du, Mao-Hua; Melcher, Charles L.

    2015-10-05

    CsCe2Br7 is a self-activated inorganic scintillator that shows promising performance, but the understanding of the important structure-property relationships is lacking. In this work, we conduct a comprehensive study on CCsCe2Br7. The crystal structure of CsCe2Br7 is refined using single crystal X-ray study for the first time. It crystallizes into the orthorhombic crystal system with Pmnb space group. Its electronic structure is revealed by Density Functional Theory (DFT) calculations. Two cerium emission centers are identified and the energy barriers related to the thermal quenching to 4f ground states of Ce3+ for these two Ce centers are evaluated. CsCe2Br7 single crystal has better light yield and energy resolution than CsCe2Cl7, but with an additional slow decay component of 1.7 s. The existence of a deep trap with a depth of 0.9 eV in CsCe2Cl7 contributes to its higher afterglow level in comparison to that of CsCe2Br7. The most possible point defects in CsCe2Cl7 and CsCe2Br7 are proposed by considering the vapour pressure in the growth atmosphere upon melting point.

  3. A Novel Approach To Mineral Carbonation: Enhancing Carbonation While Avoiding Mineral Pretreatment Process Cost

    SciTech Connect

    Michael J. McKelvy; Andrew V. G. Chizmeshya; Kyle Squires; Ray W. Carpenter; Hamdallah Bearat

    2006-06-21

    Known fossil fuel reserves, especially coal, can support global energy demands for centuries to come, if the environmental problems associated with CO{sub 2} emissions can be overcome. Unlike other CO{sub 2} sequestration candidate technologies that propose long-term storage, mineral sequestration provides permanent disposal by forming geologically stable mineral carbonates. Carbonation of the widely occurring mineral olivine (e.g., forsterite, Mg{sub 2}SiO{sub 4}) is a large-scale sequestration process candidate for regional implementation, which converts CO{sub 2} into the environmentally benign mineral magnesite (MgCO{sub 3}). The primary goal is cost-competitive process development. As the process is exothermic, it inherently offers low-cost potential. Enhancing carbonation reactivity is key to economic viability. Recent studies at the U.S. DOE Albany Research Center have established that aqueous-solution carbonation using supercritical CO{sub 2} is a promising process; even without olivine activation, 30-50% carbonation has been achieved in an hour. Mechanical activation (e.g., attrition) has accelerated the carbonation process to an industrial timescale (i.e., near completion in less than an hour), at reduced pressure and temperature. However, the activation cost is too high to be economical and lower cost pretreatment options are needed. Herein, we report our second year progress in exploring a novel approach that offers the potential to substantially enhance carbonation reactivity while bypassing pretreatment activation. As our second year progress is intimately related to our earlier work, the report is presented in that context to provide better overall understanding of the progress made. We have discovered that robust silica-rich passivating layers form on the olivine surface during carbonation. As carbonation proceeds, these passivating layers thicken, fracture and eventually exfoliate, exposing fresh olivine surfaces during rapidly

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  6. 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

    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.}

  7. Vortex Lattice Studies in CeCoIn₅ with H⊥c

    DOE PAGES [OSTI]

    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

  8. Theoretical studies of Ir5Th and Ir5Ce nanoscale precipitates in Ir

    SciTech Connect

    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.

  9. Differential conductance and defect states in the heavy-fermion superconductor CeCoIn5

    DOE PAGES [OSTI]

    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.

  10. Nanostructured Lanthanum Halides and CeBr3 for Nuclear Radiation and Detection

    SciTech Connect

    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

  11. The effect of Au and Ni doping on the heavy fermion state of the Kondo lattice antiferromagnet CePtZn

    SciTech Connect

    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.

  12. Improved thermoelectric performance of n-type Ca and Ca-Ce filled skutterudites

    DOE PAGES [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 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

  13. Improved thermoelectric performance of n-type Ca and Ca-Ce filled skutterudites

    SciTech Connect

    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, 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. 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.

  14. Improved thermoelectric performance of n-type Ca and Ca-Ce filled skutterudites

    SciTech Connect

    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.

  15. Microbial mineral colonization across a subsurface redox transition zone

    DOE PAGES [OSTI]

    Converse, Brandon J.; McKinley, James P.; Resch, Charles T.; Roden, Eric E.

    2015-08-28

    Here our study employed 16S rRNA gene amplicon pyrosequencing to examine the hypothesis that chemolithotrophic Fe(II)-oxidizing bacteria (FeOB) would preferentially colonize the Fe(II)-bearing mineral biotite compared to quartz sand when the minerals were incubated in situ within a subsurface redox transition zone (RTZ) at the Hanford 300 Area site in Richland, WA, USA. The work was motivated by the recently documented presence of neutral-pH chemolithotrophic FeOB capable of oxidizing structural Fe(II) in primary silicate and secondary phyllosilicate minerals in 300 Area sediments and groundwater (Benzine et al., 2013). Sterilized portions of sand+biotite or sand alone were incubated in situ formore » 5 months within a multilevel sampling (MLS) apparatus that spanned a ca. 2-m interval across the RTZ in two separate groundwater wells. Parallel MLS measurements of aqueous geochemical species were performed prior to deployment of the minerals. Contrary to expectations, the 16S rRNA gene libraries showed no significant difference in microbial communities that colonized the sand+biotite vs. sand-only deployments. Both mineral-associated and groundwater communities were dominated by heterotrophic taxa, with organisms from the Pseudomonadaceae accounting for up to 70% of all reads from the colonized minerals. These results are consistent with previous results indicating the capacity for heterotrophic metabolism (including anaerobic metabolism below the RTZ) as well as the predominance of heterotrophic taxa within 300 Area sediments and groundwater. Although heterotrophic organisms clearly dominated the colonized minerals, several putative lithotrophic (NH4+, H2, Fe(II), and HS- oxidizing) taxa were detected in significant abundance above and within the RTZ. Such organisms may play a role in the coupling of anaerobic microbial metabolism to oxidative pathways with attendant impacts on elemental cycling and redox-sensitive contaminant behavior in the vicinity of the RTZ.« less

  16. Superior performance of Ni-W-Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

    DOE PAGES [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; 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

  17. The effect of Ce{sup 4+} incorporation on structural, morphological and photocatalytic characters of ZnO nanoparticles

    SciTech Connect

    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.

  18. Kondo lattice and antiferromagnetic behavior in quaternary CeTAl4Si2 (T = Rh, Ir) single crystals

    DOE PAGES [OSTI]

    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

  19. Investigation of the physical properties of the tetragonal CeMAl4Si2 (M = Rh, Ir, Pt) compounds

    DOE PAGES [OSTI]

    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. LOW TEMPERATURE GEOTHERMAL MINERAL RECOVERY PROGRAM 02/11/2014 | Department

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    of Energy LOW TEMPERATURE GEOTHERMAL MINERAL RECOVERY PROGRAM 02/11/2014 LOW TEMPERATURE GEOTHERMAL MINERAL RECOVERY PROGRAM 02/11/2014 mineral-webinar.pdf (3.45 MB) More Documents & Publications LOW TEMPERATURE GEOTHERMAL MINERAL RECOVERY PROGRAM Geothermal Play Fairway Analysis Geothermal Play Fairway Analysis

  1. Hydrothermal Phase Relations Among Uranyl Minerals at the Nopal I Analog Site

    SciTech Connect

    Murphy, William M.

    2007-07-01

    Uranyl mineral paragenesis at Nopal I is an analog of spent fuel alteration at Yucca Mountain. Petrographic studies suggest a variety of possible hydrothermal conditions for uranium mineralization at Nopal I. Calculated equilibrium phase relations among uranyl minerals show uranophane stability over a broad range of realistic conditions and indicate that uranyl mineral variety reflects persistent chemical potential heterogeneity. (author)

  2. Diagenesis and clay mineral formation at Gale Crater, Mars

    DOE PAGES [OSTI]

    Bridges, J. C.; Schwenzer, S. P.; Leveille, R.; Westall, F.; Wiens, R. C.; Mangold, N.; Bristow, T.; Edwards, P.; Berger, G.

    2015-01-18

    The Mars Science Laboratory rover Curiosity found host rocks of basaltic composition and alteration assemblages containing clay minerals at Yellowknife Bay, Gale Crater. On the basis of the observed host rock and alteration minerals, we present results of equilibrium thermochemical modeling of the Sheepbed mudstones of Yellowknife Bay in order to constrain the formation conditions of its secondary mineral assemblage. Building on conclusions from sedimentary observations by the Mars Science Laboratory team, we assume diagenetic, in situ alteration. The modeling shows that the mineral assemblage formed by the reaction of a CO₂-poor and oxidizing, dilute aqueous solution (Gale Portage Water)more » in an open system with the Fe-rich basaltic-composition sedimentary rocks at 10–50°C and water/rock ratio (mass of rock reacted with the starting fluid) of 100–1000, pH of ~7.5–12. Model alteration assemblages predominantly contain phyllosilicates (Fe-smectite, chlorite), the bulk composition of a mixture of which is close to that of saponite inferred from Chemistry and Mineralogy data and to that of saponite observed in the nakhlite Martian meteorites and terrestrial analogues. To match the observed clay mineral chemistry, inhomogeneous dissolution dominated by the amorphous phase and olivine is required. We therefore deduce a dissolving composition of approximately 70% amorphous material, with 20% olivine, and 10% whole rock component.« less

  3. Synthesis, Structures, and Magnetic Properties of Rare-Earth Cobalt Arsenides, RCo2As2 (R = La, Ce, Pr, Nd)

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  5. An active atmospheric methane sink in high Arctic mineral cryosols

    SciTech Connect

    Lau, Maggie C.Y.; Stackhouse, B.; Layton, Alice C.; Chauhan, Archana; Vishnivetskaya, T. A.; Chourey, Karuna; Mykytczuk, N. C.S.; Bennett, Phil C.; Lamarche-Gagnon, G.; Burton, N.; Renholm, J.; Hettich, R. L.; Pollard, W. H.; Omelon, C. R.; Medvigy, David M.; Pffifner, Susan M.; Whyte, L. G.; Onstott, T. C.

    2015-04-14

    The transition of Arctic carbon-rich cryosols into methane (CH₄)-emitting wetlands due to global warming is a rising concern. However, the spatially predominant mineral cryosols and their CH₄ emission potential are poorly understood. Fluxes measured in situ and estimated under laboratory conditions coupled with -omics analysis indicate (1) mineral cryosols in the Canadian high Arctic contain atmospheric CH₄-oxidizing bacteria; (2) the atmospheric CH⁺ uptake flux increases with ground temperature; and, as a result, (3) the atmospheric CH₄ sink strength will increase by a factor of 5-30 as the Arctic warms by 5-15 °C over a century. We demonstrated that acidic mineral cryosols have previously unrecognized potential of negative CH₄ feedback.

  6. An active atmospheric methane sink in high Arctic mineral cryosols

    SciTech Connect

    Lau, Maggie C.Y.; Stackhouse, B.; Layton, Alice C.; Chauhan, Archana; Vishnivetskaya, T. A.; Chourey, Karuna; Mykytczuk, N. C.S.; Bennett, Phil C.; Lamarche-Gagnon, G.; Burton, N.; Renholm, J.; Hettich, R. L.; Pollard, W. H.; Omelon, C. R.; Medvigy, David M.; Pffifner, Susan M.; Whyte, L. G.; Onstott, T. C.

    2015-01-01

    The transition of Arctic carbon-rich cryosols into methane (CH₄)-emitting wetlands due to global warming is a rising concern. However, the spatially predominant mineral cryosols and their CH₄ emission potential are poorly understood. Fluxes measured in situ and estimated under laboratory conditions coupled with -omics analysis indicate (1) mineral cryosols in the Canadian high Arctic contain atmospheric CH₄-oxidizing bacteria; (2) the atmospheric CH⁺ uptake flux increases with ground temperature; and, as a result, (3) the atmospheric CH₄ sink strength will increase by a factor of 5-30 as the Arctic warms by 5-15 °C over a century. We demonstrated that acidic mineral cryosols have previously unrecognized potential of negative CH₄ feedback.

  7. Reverse micelles directed synthesis of TiO{sub 2}-CeO{sub 2} mixed oxides and investigation of their crystal structure and morphology

    SciTech Connect

    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.

  8. Structures and thermoelectric properties of double-filled (Ca{sub x}Ce{sub 1−x})Fe{sub 4}Sb{sub 12} skutterudites

    SciTech Connect

    Yan, Y.G.; Wong-Ng, W.; Li, L.; Levin, I.; Kaduk, J.A.; Suchomel, M.R.; Sun, X.; Tan, G.J.; Tang, X.F.

    2014-10-15

    The structures and thermoelectric properties of the double-filled (Ca{sub x}Ce{sub 1−x})Fe{sub 4}Sb{sub 12} series (x=0, 0.25, 0.5, 0.75, and 1) have been studied using a combined experimental and computational methods. Compounds of (Ca{sub x}Ce{sub 1−x})Fe{sub 4}Sb{sub 12} were obtained only for x=0, 0.5, and 1. Composition with x=0.25 was found to be a mixture of x=0 and 0.5 compounds, and composition with x=0.75 was found to be a mixture of x=1 and 0.5 compounds, respectively. Our conclusions on phase formation are supported by density functional theory (DFT) calculations. In Ca{sub 0.5}Ce{sub 0.5}Fe{sub 4}Sb{sub 12,} Ca substitution in the Ce site of CeFe{sub 4}Sb{sub 12} leads to high hole concentrations, resulting in stronger semimetal transport as compared to CeFe{sub 4}Sb{sub 12}. Ca{sub 0.5}Ce{sub 0.5}Fe{sub 4}Sb{sub 12} yields a slightly higher ZT value than that of CeFe{sub 4}Sb{sub 12}, which is attributed to its lower lattice thermal conductivity. Phonon mode calculations adopting a three-particle bending model suggest that thermal conductivity is reduced upon Ca substitution because of an additional vibration mode which involves both Ca and Ce atoms. - Graphical abstract: Detailed structural information to correlate with thermoelectric properties in a series of double-filled (Ca{sub x}Ce{sub 1−x})Fe{sub 4}Sb{sub 12} skutterudite samples were obtained using synchrotron X-ray diffraction and first principle calculations. - Highlights: • Research focus on phase stability of CaCe double-filled p-type skutterudite. • Stable structure forms for an equiatomic occupancy of the voids by Ca and Ce. • Samples feature two-phase mixtures with variations of filling atoms ratio. • Phase stablility is investigated by DFT total energy calculations. • Sample with Equiatomic occupancy of Ca and Ce show higher ZT.

  9. "Terrywallaceite" now in official roster of known minerals

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    » June » "Terrywallaceite" Now In Official Roster Of Known Minerals "Terrywallaceite" now in official roster of known minerals The slender, needle-like metallic-black crystals of Terrywallaceite were found in the Julcani Mining District of Peru. June 8, 2011 The mineral "Terrywallaceite" The mineral "Terrywallaceite" I am honored and humbled that a group of geoscientists and peers would suggest naming a mineral after me and that the international

  10. A Novel Approach to Mineral Carbonation: Enhancing Carbonation While Avoiding Mineral Pretreatment Process Cost

    SciTech Connect

    Andrew V. G. Chizmeshya; Michael J. McKelvy; Kyle Squires; Ray W. Carpenter; Hamdallah Bearat

    2007-06-21

    Known fossil fuel reserves, especially coal, can support global energy demands for centuries to come, if the environmental problems associated with CO{sub 2} emissions can be overcome. Unlike other CO{sub 2} sequestration candidate technologies that propose long-term storage, mineral sequestration provides permanent disposal by forming geologically stable mineral carbonates. Carbonation of the widely occurring mineral olivine (e.g., forsterite, Mg{sub 2}SiO{sub 4}) is a large-scale sequestration process candidate for regional implementation, which converts CO{sub 2} into the environmentally benign mineral magnesite (MgCO{sub 3}). The primary goal is cost-competitive process development. As the process is exothermic, it inherently offers low-cost potential. Enhancing carbonation reactivity is key to economic viability. Recent studies at the U.S. DOE Albany Research Center have established that aqueous-solution carbonation using supercritical CO{sub 2} is a promising process; even without olivine activation, 30-50% carbonation has been achieved in an hour. Mechanical activation (e.g., attrition) has accelerated the carbonation process to an industrial timescale (i.e., near completion in less than an hour), at reduced pressure and temperature. However, the activation cost is too high to be economical and lower cost pretreatment options are needed. We have discovered that robust silica-rich passivating layers form on the olivine surface during carbonation. As carbonation proceeds, these passivating layers thicken, fracture and eventually exfoliate, exposing fresh olivine surfaces during rapidly-stirred/circulating carbonation. We are exploring the mechanisms that govern carbonation reactivity and the impact that (1) modeling/controlling the slurry fluid-flow conditions, (2) varying the aqueous ion species/size and concentration (e.g., Li+, Na+, K+, Rb+, Cl-, HCO{sub 3}{sup -}), and (3) incorporating select sonication offer to enhance exfoliation and carbonation. Thus

  11. Iowa State Mining and Mineral Resources Research Institute

    SciTech Connect

    Not Available

    1990-08-01

    This final report describes the activities of the Iowa State Mining and Mineral Resources Research Institute (ISMMRRI) at Iowa State University for the period July 1, 1989, to June 30, 1990. Activities include research in mining- and mineral-related areas, education and training of scientists and engineers in these fields, administration of the Institute, and cooperative interactions with industry, government agencies, and other research centers. During this period, ISMMRRI has supported research efforts to: (1) Investigate methods of leaching zinc from sphalerite-containing ores. (2) Study the geochemistry and geology of an Archean gold deposit and of a gold-telluride deposit. (3) Enchance how-quality aggregates for use in construction. (4) Pre-clean coal by triboelectric charging in a fluidized-bed. (5) Characterize the crystal/grain alignment during processing of yttrium-barium-copper-perovskite (1-2-3) superconductors. (5) Study the fluid inclusion properties of a fluorite district. (6) Study the impacts of surface mining on community planning. (7) Assess the hydrophobicity of coal and pyrite for beneficiation. (8) Investigate the use of photoacoustic absorption spectroscopy for monitoring unburnt carbon in the exhaust gas from coal-fired boilers. The education and training program continued within the interdepartmental graduate minor in mineral resources includes courses in such areas as mining methods, mineral processing, industrial minerals, extractive metallurgy, coal science and technology, and reclamation of mined land. In addition, ISMMRRI hosted the 3rd International Conference on Processing and Utilization of High-Sulfur Coals in Ames, Iowa. The Institute continues to interact with industry in order to foster increased cooperation between academia and the mining and mineral community.

  12. Low Temperature Geothermal Mineral Recovery Program | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Low Temperature Geothermal Mineral Recovery Program Low Temperature Geothermal Mineral Recovery Program February 4, 2014 - 2:59pm Addthis Funding: Total Amount to be Awarded $3,000,000, EERE anticipates making awards that range from $200,000 to $500,000. Open Date: 02/04/2014 Close Date: 05/02/2014 Funding Organization: Department of Energy Geothermal Technologies Office Funding Number: DE-FOA-0001016 Summary: The intention of this FOA is to have awardees examine the feasibility of extracting

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

    SciTech Connect

    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.

  14. Detection of trisomy 7 in bronchial cells from uranium miners

    SciTech Connect

    Lechner, J.F.; Neft, R.E.; Belinsky, S.A.

    1995-12-01

    New Mexico was the largest producer of uranium in the western world during 1960s and 1970s. Investigators at the University of New Mexico School of Medicine`s Epidemiology and Cancer Control Program have been conducting epidemiological studies on uranium miners over the past 2 decades. Currently, this cohort includes more than 3600 men who had completed at least 1 y of underground work experience in New Mexico by December 31, 1976. These miners, who are now in their 5th through 7th decades, the age when lung cancer incidence is highest, are at high risk for developing this disease because they were exposed to high levels of radon progeny in the mines, and they also smoked tobacco. However, not all people comparably exposed develop lung cancer; in fact, the lifetime risk of lung cancer for the smoking uranium miners has been projected by epidemiological analyses to be no higher than 50%. Therefore, the identification of gene alterations in bronchial epithelium would be a valuable tool to ascertain which miners are at greatest risk for lung cancer. The underlying significance of the current effort confirms the hypothesis that chronic exposure to high concentrations of {alpha}-particles and tobacco smoke produces genetically altered lung epithelial cells throughout the respiratory tract of some susceptible individuals before they develop clinical disease.

  15. Mineral density volume gradients in normal and diseased human tissues

    DOE PAGES [OSTI]

    Djomehri, Sabra I.; Candell, Susan; Case, Thomas; Browning, Alyssa; Marshall, Grayson W.; Yun, Wenbing; Lau, S. H.; Webb, Samuel; Ho, Sunita P.; Aikawa, Elena

    2015-04-09

    Clinical computed tomography provides a single mineral density (MD) value for heterogeneous calcified tissues containing early and late stage pathologic formations. The novel aspect of this study is that, it extends current quantitative methods of mapping mineral density gradients to three dimensions, discretizes early and late mineralized stages, identifies elemental distribution in discretized volumes, and correlates measured MD with respective calcium (Ca) to phosphorus (P) and Ca to zinc (Zn) elemental ratios. To accomplish this, MD variations identified using polychromatic radiation from a high resolution micro-computed tomography (micro-CT) benchtop unit were correlated with elemental mapping obtained from a microprobe X-raymore » fluorescence (XRF) using synchrotron monochromatic radiation. Digital segmentation of tomograms from normal and diseased tissues (N=5 per group; 40-60 year old males) contained significant mineral density variations (enamel: 2820-3095mg/cc, bone: 570-1415mg/cc, cementum: 1240-1340mg/cc, dentin: 1480-1590mg/cc, cementum affected by periodontitis: 1100-1220mg/cc, hypomineralized carious dentin: 345-1450mg/cc, hypermineralized carious dentin: 1815-2740mg/cc, and dental calculus: 1290-1770mg/cc). A plausible linear correlation between segmented MD volumes and elemental ratios within these volumes was established, and Ca/P ratios for dentin (1.49), hypomineralized dentin (0.32-0.46), cementum (1.51), and bone (1.68) were observed. Furthermore, varying Ca/Zn ratios were distinguished in adapted compared to normal tissues, such as in bone (855-2765) and in cementum (595-990), highlighting Zn as an influential element in prompting observed adaptive properties. Hence, results provide insights on mineral density gradients with elemental concentrations and elemental footprints that in turn could aid in elucidating mechanistic processes for pathologic formations.« less

  16. Mineral density volume gradients in normal and diseased human tissues

    SciTech Connect

    Djomehri, Sabra I.; Candell, Susan; Case, Thomas; Browning, Alyssa; Marshall, Grayson W.; Yun, Wenbing; Lau, S. H.; Webb, Samuel; Ho, Sunita P.; Aikawa, Elena

    2015-04-09

    Clinical computed tomography provides a single mineral density (MD) value for heterogeneous calcified tissues containing early and late stage pathologic formations. The novel aspect of this study is that, it extends current quantitative methods of mapping mineral density gradients to three dimensions, discretizes early and late mineralized stages, identifies elemental distribution in discretized volumes, and correlates measured MD with respective calcium (Ca) to phosphorus (P) and Ca to zinc (Zn) elemental ratios. To accomplish this, MD variations identified using polychromatic radiation from a high resolution micro-computed tomography (micro-CT) benchtop unit were correlated with elemental mapping obtained from a microprobe X-ray fluorescence (XRF) using synchrotron monochromatic radiation. Digital segmentation of tomograms from normal and diseased tissues (N=5 per group; 40-60 year old males) contained significant mineral density variations (enamel: 2820-3095mg/cc, bone: 570-1415mg/cc, cementum: 1240-1340mg/cc, dentin: 1480-1590mg/cc, cementum affected by periodontitis: 1100-1220mg/cc, hypomineralized carious dentin: 345-1450mg/cc, hypermineralized carious dentin: 1815-2740mg/cc, and dental calculus: 1290-1770mg/cc). A plausible linear correlation between segmented MD volumes and elemental ratios within these volumes was established, and Ca/P ratios for dentin (1.49), hypomineralized dentin (0.32-0.46), cementum (1.51), and bone (1.68) were observed. Furthermore, varying Ca/Zn ratios were distinguished in adapted compared to normal tissues, such as in bone (855-2765) and in cementum (595-990), highlighting Zn as an influential element in prompting observed adaptive properties. Hence, results provide insights on mineral density gradients with elemental concentrations and elemental footprints that in turn could aid in elucidating mechanistic processes for pathologic formations.

  17. Kondo hole behavior in Ce{sub 0.97} La{sub 0.03}Pd{sub 3}

    SciTech Connect

    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.}

  18. Combined local-density and dynamical mean field theory calculations for the compressed lanthanides Ce, Pr, and Nd

    SciTech Connect

    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.

  19. Fundamental study of CO2-H2O-mineral interactions for carbon sequestration,

    Office of Scientific and Technical Information (OSTI)

    with emphasis on the nature of the supercritical fluid-mineral interface. (Technical Report) | SciTech Connect Fundamental study of CO2-H2O-mineral interactions for carbon sequestration, with emphasis on the nature of the supercritical fluid-mineral interface. Citation Details In-Document Search Title: Fundamental study of CO2-H2O-mineral interactions for carbon sequestration, with emphasis on the nature of the supercritical fluid-mineral interface. In the supercritical CO2-water-mineral

  20. Effect of Oxygen Defects on the Catalytic Performance of VOx/CeO2 Catalysts for Oxidative Dehydrogenation of Methanol

    SciTech Connect

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

    SciTech Connect

    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 manganese 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.

  2. One-, two-, and three-channel Kondo effects for a model Ce{sup 3+} impurity in a metal

    SciTech Connect

    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}

  3. Strongly enhanced oxygen ion transport through samarium-doped CeO2 nanopillars in nanocomposite films

    DOE PAGES [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 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

  4. Crystal structure and thermal expansion of a CsCe2Cl7 scintillator

    SciTech Connect

    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.

  5. Influence of Electron Doping on Magnetic Order in CeRu2Al10

    SciTech Connect

    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.

  6. Strongly enhanced oxygen ion transport through samarium-doped CeO2 nanopillars in nanocomposite films

    DOE PAGES [OSTI]

    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

  7. Remarkably robust and correlated coherence and antiferromagnetism in (Ce1-xLax)Cu2Ge2

    DOE PAGES [OSTI]

    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

  8. Strongly enhanced oxygen ion transport through samarium-doped CeO2 nanopillars in nanocomposite films

    SciTech Connect

    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.

  9. Structural characterization of the CeO{sub 2}/Gd{sub 2}O{sub 3} mixed system by synchrotron X-ray diffraction

    SciTech Connect

    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.

  10. 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

    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

  11. SESAME 96170, a solid-liquid equation of state for CeO2

    SciTech Connect

    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.

  12. A ferromagnetic quantum critical point in heavy-fermion iron oxypnictide CeFe{sub 1?x}Cr{sub x}PO

    SciTech Connect

    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.

  13. Superior performance of Ni–W–Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

    SciTech Connect

    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.

  14. Crystalline Electric Field as a Probe for Long-Range Antiferromagnetic Order and Superconducting State of CeFeAsO1-xFx

    SciTech Connect

    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.

  15. Superior performance of Ni-W-Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

    SciTech Connect

    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.

  16. Superior performance of Ni–W–Ce mixed-metal oxide catalysts for ethanol steam reforming: Synergistic effects of W- and Ni-dopants

    DOE PAGES [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.; 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

  17. File:Land sale mineral release complete.pdf | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    Land sale mineral release complete.pdf Jump to: navigation, search File File history File usage File:Land sale mineral release complete.pdf Size of this preview: 463 599 pixels....

  18. File:03HIAReservedLandMineralLeasingProcess.pdf | Open Energy...

    OpenEI (Open Energy Information) [EERE & EIA]

    HIAReservedLandMineralLeasingProcess.pdf Jump to: navigation, search File File history File usage Metadata File:03HIAReservedLandMineralLeasingProcess.pdf Size of this preview: 463...

  19. File:03HIBStateMineralLeasingProcess.pdf | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    3HIBStateMineralLeasingProcess.pdf Jump to: navigation, search File File history File usage Metadata File:03HIBStateMineralLeasingProcess.pdf Size of this preview: 463 599...

  20. File:03AKAStateCompetitiveMineralLeasingProcess.pdf | Open Energy...

    OpenEI (Open Energy Information) [EERE & EIA]

    3AKAStateCompetitiveMineralLeasingProcess.pdf Jump to: navigation, search File File history File usage Metadata File:03AKAStateCompetitiveMineralLeasingProcess.pdf Size of this...

  1. Geophysical technique for mineral exploration and discrimination based on electromagnetic methods and associated systems

    DOEpatents

    Zhdanov; Michael S.

    2008-01-29

    Mineral exploration needs a reliable method to distinguish between uneconomic mineral deposits and economic mineralization. A method and system includes a geophysical technique for subsurface material characterization, mineral exploration and mineral discrimination. The technique introduced in this invention detects induced polarization effects in electromagnetic data and uses remote geophysical observations to determine the parameters of an effective conductivity relaxation model using a composite analytical multi-phase model of the rock formations. The conductivity relaxation model and analytical model can be used to determine parameters related by analytical expressions to the physical characteristics of the microstructure of the rocks and minerals. These parameters are ultimately used for the discrimination of different components in underground formations, and in this way provide an ability to distinguish between uneconomic mineral deposits and zones of economic mineralization using geophysical remote sensing technology.

  2. Rend Lake College celebrates the opening of a new coal miner training facility

    SciTech Connect

    Buchsbaum, L.

    2009-09-15

    The Coal Miner Training Center at Rend Lake College recently hosted the Illinois Mining Institute's annual conference and a regional mine rescue competition. The article gives an outline of the coal miner training and refresher course offered. 3 photos.

  3. Abiotic/Biotic Degradation and Mineralization of N-Nitrosodimethylamine in Aquifer Sediments

    SciTech Connect

    Szecsody, James E.; McKinley, James P.; Breshears, Andrew T.; Crocker, Fiona H.

    2008-10-14

    The N-nitrosodimethylamine (NDMA) degradation rate and mineralization rate were measured in two aquifer sediments that received treatments to create oxic, reducing, and sequential reducing/oxic environments. Chemically reduced sediments rapidly abiotically degraded NDMA to nontoxic dimethylamine (DMA) to parts per trillion levels, then degraded to further products. NDMA was partially mineralized in reduced sediments (6 to 28 percent) at a slow rate (half-life 3,460 h) by an unknown abiotic/biotic pathway. In contrast, NDMA was mineralized more rapidly (half-life 342 h) and to a greater extent (30 to 81 percent) in oxic sediments with propane addition, likely by a propane monooxygenase pathway. NDMA mineralization in sequential reduced sediment followed by oxic sediment treatment did result in slightly more rapid mineralization and a greater mineralization extent relative to reduced systems. These increases were minor, so aerobic NDMA mineralization with oxygen and propane addition was the most viable in situ NDMA mineralization strategy.

  4. RCW 79.14 Mineral, Coal, Oil and Gas Leases | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    79.14 Mineral, Coal, Oil and Gas Leases Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: RCW 79.14 Mineral, Coal, Oil and Gas...

  5. An active atmospheric methane sink in high Arctic mineral cryosols

    DOE PAGES [OSTI]

    Lau, Maggie C.Y.; Stackhouse, B.; Layton, Alice C.; Chauhan, Archana; Vishnivetskaya, T. A.; Chourey, Karuna; Mykytczuk, N. C.S.; Bennett, Phil C.; Lamarche-Gagnon, G.; Burton, N.; et al

    2015-01-01

    The transition of Arctic carbon-rich cryosols into methane (CH₄)-emitting wetlands due to global warming is a rising concern. However, the spatially predominant mineral cryosols and their CH₄ emission potential are poorly understood. Fluxes measured in situ and estimated under laboratory conditions coupled with -omics analysis indicate (1) mineral cryosols in the Canadian high Arctic contain atmospheric CH₄-oxidizing bacteria; (2) the atmospheric CH⁺ uptake flux increases with ground temperature; and, as a result, (3) the atmospheric CH₄ sink strength will increase by a factor of 5-30 as the Arctic warms by 5-15 °C over a century. We demonstrated that acidic mineralmore » cryosols have previously unrecognized potential of negative CH₄ feedback.« less

  6. Method of analysis of asbestiform minerals by thermoluminescence

    DOEpatents

    Fisher, Gerald L.; Bradley, Edward W.

    1980-01-01

    A method for the qualitative and quantitative analysis of asbestiform minerals, including the steps of subjecting a sample to be analyzed to the thermoluminescent analysis, annealing the sample, subjecting the sample to ionizing radiation, and subjecting the sample to a second thermoluminescent analysis. Glow curves are derived from the two thermoluminescent analyses and their shapes then compared to established glow curves of known asbestiform minerals to identify the type of asbestiform in the sample. Also, during at least one of the analyses, the thermoluminescent response for each sample is integrated during a linear heating period of the analysis in order to derive the total thermoluminescence per milligram of sample. This total is a measure of the quantity of asbestiform in the sample and may also be used to identify the source of the sample.

  7. Calc-silicate mineralization in active geothermal systems

    SciTech Connect

    Bird, D.K.; Schiffman, P.; Elders, W.A.; Williams, A.E.; McDowell, S.D.

    1983-01-01

    The detailed study of calc-silicate mineral zones and coexisting phase relations in the Cerro Prieto geothermal system were used as examples for thermodynamic evaluation of phase relations among minerals of variable composition and to calculate the chemical characteristics of hydrothermal solutions compatible with the observed calc-silicate assemblages. In general there is a close correlation between calculated and observed fluid compositions. Calculated fugacities of O{sub 2} at about 320{degrees}C in the Cerro Prieto geothermal system are about five orders of magnitude less than that at the nearby Salton Sea geothermal system. This observation is consistent with the occurrence of Fe{sup 3+} rich epidotes in the latter system and the presence of prehnite at Cerro Prieto.

  8. Radiolysis of alanine adsorbed in a clay mineral

    SciTech Connect

    Aguilar-Ovando, Ellen Y.; Negron-Mendoza, Alicia

    2013-07-03

    Optical activity in molecules is a chemical characteristic of living beings. In this work, we examine the hypothesis of the influence of different mineral surfaces on the development of a specific chirality in organic molecules when subjected to conditions simulating the primitive Earth during the period of chemical evolution. By using X-ray diffraction techniques and HPLC/ELSD to analyze aqueous suspensions of amino acids adsorbed on minerals irradiated in different doses with a cobalt-60 gamma source, the experiments attempt to prove the hypothesis that some solid surfaces (like clays and meteorite rocks) may have a concentration capacity and protective role against external sources of ionizing radiation (specifically {gamma}-ray) for some organic compounds (like some amino acids) adsorbed on them. Preliminary results show a slight difference in the adsorption and radiolysis of the D-and L-alanine.

  9. Investigating Radiation Shielding Properties of Different Mineral Origin Heavyweight Concretes

    SciTech Connect

    Basyigit, Celalettin; Uysal, Volkan; Kilincarslan, Semsettin; Akkas, Ayse; Mavi, Betuel; Guenoglu, Kadir; Akkurt, Iskender

    2011-12-26

    The radiation although has hazardous effects for human health, developing technologies bring lots of usage fields to radiation like in medicine and nuclear power station buildings. In this case protecting from undesirable radiation is a necessity for human health. Heavyweight concrete is one of the most important materials used in where radiation should be shielded, like those areas. In this study, used heavyweight aggregates of different mineral origin (Limonite, Siderite), in order to prepare different series in concrete mixtures and investigated radiation shielding properties. The experimental results on measuring the radiation shielding, the heavyweight concrete prepared with heavyweight aggregates of different mineral origin show that, are useful radiation absorbents when they used in concrete mixtures.

  10. Hydrodesulfurization and hydrodenitrogenation catalysts obtained from coal mineral matter

    DOEpatents

    Liu, Kindtoken H. D.; Hamrin, Jr., Charles E.

    1982-01-01

    A hydrotreating catalyst is prepared from coal mineral matter obtained by low temperature ashing coals of relatively low bassanite content by the steps of: (a) depositing on the low temperature ash 0.25-3 grams of an iron or nickel salt in water per gram of ash and drying a resulting slurry; (b) crushing and sizing a resulting solid; and (c) heating the thus-sized solid powder in hydrogen.

  11. Ba{sub 2}B{sub 2}O{sub 5}:Ce{sup 3+}: A novel blue emitting phosphor for white LEDs

    SciTech Connect

    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.

  12. Hierarchical Heterogeneity at the CeO x –TiO 2 Interface: Electronic and Geometric Structural Influence on the Photocatalytic Activity of Oxide on Oxide Nanostructures

    DOE PAGES [OSTI]

    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

  13. Hierarchical heterogeneity at the CeOx-TiO? interface: Electronic and geometric structural influence on the photocatalytic activity of oxide on oxide nanostructures

    DOE PAGES [OSTI]

    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

  14. Fabrication and microstructure of cerium doped lutetium aluminum garnet (Ce:LuAG) transparent ceramics by solid-state reaction method

    SciTech Connect

    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.

  15. Synthesis of mesoporous Bi{sub 2}O{sub 3}/CeO{sub 2} microsphere for photocatalytic degradation of Orange II dye

    SciTech Connect

    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.

  16. Heavy fermion Ce{sub 3}Co{sub 4}Sn{sub 13} compound under pressure

    SciTech Connect

    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.

  17. Comparative Gamma Spectroscopy with SrI2(Eu), GYGAG(Ce) and Bi-loaded Plastic Scintillators

    SciTech Connect

    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.

  18. Response of LaBr{sub 3}(Ce) scintillators to 2.5 MeV fusion neutrons

    SciTech Connect

    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.

  19. Effect of magnetic fields on the Kondo insulator CeRhSb: Magnetoresistance and high-field heat capacity measurements

    SciTech Connect

    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}

  20. Generation and reactivity of putative support systems, Ce-Al neutral binary oxide nanoclusters: CO oxidation and CH bond activation

    SciTech Connect

    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

  1. NOVEL IN-SITU METAL AND MINERAL EXTRACTION TECHNOLOGY

    SciTech Connect

    Glenn O'Gorman; Hans von Michaelis; Gregory J. Olson

    2004-09-22

    This white paper summarizes the state of art of in-situ leaching of metals and minerals, and describes a new technology concept employing improved fragmentation of ores underground in order to prepare the ore for more efficient in-situ leaching, combined with technology to continuously improve solution flow patterns through the ore during the leaching process. The process parameters and economic benefits of combining the new concept with chemical and biological leaching are described. A summary is provided of the next steps required to demonstrate the technology with the goal of enabling more widespread use of in-situ leaching.

  2. Rare earth element patterns in biotite, muscovite and tourmaline minerals

    SciTech Connect

    Laul, J.C.; Lepel, E.A.

    1986-04-21

    Rare earth element concentrations in the minerals biotite and muscovite from the mica schist country rocks of the Etta pegmatite and tourmalines from the Bob Ingersoll pegmatite have been measured by INAA and CNAA. The concentrations range from 10/sup -4/ g/g to 10/sup -10g//sub g/. The REE patterns of biotite, muscovite and tourmaline reported herein are highly fractionated from light to heavy REE. The REE concentrations in biotite and muscovite are high and indigenous. The pegmatite tourmalines contain low concentrations of REE. Variations in tourmaline REE patterns reflect the geochemical evolution of pegmatite melt/fluid system during crystallization.

  3. Antiferromagnetic Kondo lattice in the layered compound CePd1–xBi₂ and comparison to the superconductor LaPd1–xBi₂

    DOE PAGES [OSTI]

    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

  4. Weak hybridization and isolated localized magnetic moments in the compounds CeT2Cd20 (T = Ni, Pd)

    SciTech Connect

    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.

  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

    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. Universal heat conduction in Ce1-xYbxCoIn5: Evidence for robust nodal d-wave superconducting gap

    DOE PAGES [OSTI]

    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

  7. Effect of Doping on Surface Reactivity and Conduction Mechanism in Sm-doped CeO2 Thin Films

    DOE PAGES [OSTI]

    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

  8. Pressure-tuned quantum criticality in the antiferromagnetic Kondo semimetal CeNi2–δAs2

    DOE PAGES [OSTI]

    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

  9. Rapid Microwave Preparation of Highly Efficient Ce[superscript 3+]-Substituted Garnet Phosphors for Solid State White Lighting

    SciTech Connect

    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. Amyloid-like ribbons of amelogenins in enamel mineralization

    DOE PAGES [OSTI]

    Carneiro, Karina M. M.; Zhai, Halei; Zhu, Li; Horst, Jeremy A.; Sitlin, Melody; Nguyen, Mychi; Wagner, Martin; Simpliciano, Cheryl; Milder, Melissa; Chen, Chun-Long; et al

    2016-03-24

    We report that enamel, the outermost layer of teeth, is an acellular mineralized tissue that cannot regenerate; the mature tissue is composed of high aspect ratio apatite nanocrystals organized into rods and inter-rod regions. Amelogenin constitutes 90% of the protein matrix in developing enamel and plays a central role in guiding the hierarchical organization of apatite crystals observed in mature enamel. To date, a convincing link between amelogenin supramolecular structures and mature enamel has yet to be described, in part because the protein matrix is degraded during tissue maturation. Here we show compelling evidence that amelogenin self-assembles into an amyloid-likemore » structure in vitro and in vivo. We show that enamel matrices stain positive for amyloids and we identify a specific region within amelogenin that self-assembles into β-sheets. Lastly, we propose that amelogenin nanoribbons template the growth of apatite mineral in human enamel. This is a paradigm shift from the current model of enamel development.« less

  11. Active Layer Soil Carbon and Nutrient Mineralization, Barrow, Alaska, 2012

    DOE Data Explorer

    Stan D. Wullschleger; Holly M. Vander Stel; Colleen Iversen; Victoria L. Sloan; Richard J. Norby; Mallory P. Ladd; Jason K. Keller; Ariane Jong; Joanne Childs; Deanne J. Brice

    2015-10-29

    This data set consists of bulk soil characteristics as well as carbon and nutrient mineralization rates of active layer soils manually collected from the field in August, 2012, frozen, and then thawed and incubated across a range of temperatures in the laboratory for 28 day periods in 2013-2015. The soils were collected from four replicate polygons in each of the four Areas (A, B, C, and D) of Intensive Site 1 at the Next-Generation Ecosystem Experiments (NGEE) Arctic site near Barrow, Alaska. Soil samples were coincident with the established Vegetation Plots that are located in center, edge, and trough microtopography in each polygon. Data included are 1) bulk soil characteristics including carbon, nitrogen, gravimetric water content, bulk density, and pH in 5-cm depth increments and also by soil horizon, 2) carbon, nitrogen, and phosphorus mineralization rates for soil horizons incubated aerobically (and in one case both aerobically and anaerobically) for 28 days at temperatures that included 2, 4, 8, and 12 degrees C. Additional soil and incubation data are forthcoming. They will be available when published as part of another paper that includes additional replicate analyses.

  12. Fly ash and coal mineral matter surface transformations during heating

    SciTech Connect

    Baer, D R; Smith, R D

    1982-05-01

    A study is reported of surface segregation phenomena for fly ash and aluminosilicates representative of coal mineral matter during heating. The materials studied included a 20-..mu..m average diameter fly ash powder, a glass prepared from the fly ash, and Ca- and K-rich aluminosilicate minerals. The samples were heated both in air and under vacuum for extended periods at temperatures up to 1100/sup 0/C. XPS, Auger and SIMS methods were used to obtain relative surface elemental concentrations for major and minor components and depth profiles for some of the samples. Major differences were noted between samples heated in air (oxidizing) and those heated in vacuum (reducing) environments. For the fly ash glass heated in air Fe, Ti and Mg become enriched on the surfaces while heating in vacuum leads to Si surface segregation. Different trends upon heating were also observed for the Ca- and K-rich aluminosilicates. The results indicate two levels of surface enrichment upon the fly ash glass; a thin (< 500 A) layer and a thicker (1- to 2-..mu..m) layer most evident for heating in air where an Fe-rich layer is formed. The present results indicate that the rates of surface segregation may not be sufficiently fast on the time scale of fly ash formation to result in equilibrium surface segregation. It is concluded that condensation processes during fly ash formation probably play a major role in the observed fly ash surface enrichments.

  13. Np and Pu Sorption to Manganese Oxide Minerals

    SciTech Connect

    Zhao, P; Johnson, M R; Roberts, S K; Zavarin, M

    2005-08-30

    Manganese oxide minerals are a significant component of the fracture lining mineralogy at Yucca Mountain (Carlos et al., 1993) and within the tuff-confining unit at Yucca Flat (Prothro, 1998), Pahute Mesa (Drellack et al., 1997), and other locations at the Nevada Test Site (NTS). Radionuclide sorption to manganese oxide minerals was not included in recent Lawrence Livermore National Laboratory (LLNL) hydrologic source term (HST) models which attempt to predict the migration behavior of radionuclides away from underground nuclear tests. However, experiments performed for the Yucca Mountain Program suggest that these minerals may control much of the retardation of certain radionuclides, particularly Np and Pu (Triay et al., 1991; Duff et al., 1999). As a result, recent HST model results may significantly overpredict radionuclide transport away from underground nuclear tests. The sorption model used in HST calculations performed at LLNL includes sorption to iron oxide, calcite, zeolite, smectite, and mica minerals (Zavarin and Bruton 2004a; 2004b). For the majority of radiologic source term (RST) radionuclides, we believe that this accounts for the dominant sorption processes controlling transport. However, for the case of Np, sorption is rather weak to all but the iron and manganese oxides (Figure 1). Thus, we can expect to significantly reduce predicted Np transport by accounting for Np sorption to manganese oxides. Similarly, Pu has been shown to be predominantly associated with manganese oxides in Yucca Mountain fractured tuffs (Duff et al., 1999). Recent results on colloid-facilitated Pu transport (Kersting and Reimus, 2003) also suggest that manganese oxide coatings on fracture surfaces may compete with colloids for Pu, thus reducing the effects of colloid-facilitated Pu transport (Figure 1b). The available data suggest that it is important to incorporate Np and Pu sorption to manganese oxides in reactive transport models. However, few data are available for

  14. Chemical Reduction of Nd1.85Ce0.15CuO4??Powders in Supercritical Sodium Ammonia Solutions

    DOE PAGES [OSTI]

    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.

  15. Pressure-Induced Structural Phase Transition in CeNi: X-ray and Neutron Scattering Studies and First-Principles Calculations

    SciTech Connect

    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.

  16. Chemical Reduction of Nd 1.85 Ce 0.15 CuO 4− δ Powders in Supercritical Sodium Ammonia Solutions

    DOE PAGES [OSTI]

    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. Pressure-Induced Structural Phase Transition in CeNi: X-ray and Neutron Scattering Studies and First-Principles Calculations

    SciTech Connect

    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.

  18. Pressure-Induced Structural Phase Transition in CeNi: X-ray and Neutron Scattering Studies and First-Principles Calculations

    DOE PAGES [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 withmore » the phase transition.« less

  19. Magnetic hardening of Ce1+xFe11–yCoyTi with ThMn12 structure by melt spinning

    DOE PAGES [OSTI]

    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

  20. Reactivity of pulverized coals during combustion catalyzed by CeO{sub 2} and Fe{sub 2}O{sub 3}

    SciTech Connect

    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)

  1. Magnetic hardening of Ce1+xFe11–yCoyTi with ThMn12 structure by melt spinning

    DOE PAGES [OSTI]

    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

  2. Lu.sub.1-xI.sub.3:Ce.sub.x-a scintillator for gamma-ray spectroscopy and time-of-flight pet

    DOEpatents

    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.

  3. Quantitative determination of mineral composition by powder X-ray diffraction

    DOEpatents

    Pawloski, Gayle A.

    1986-01-01

    An external standard intensity ratio method is used for quantitatively determining mineralogic compositions of samples by x-ray diffraction. The method uses ratios of x-ray intensity peaks from a single run. Constants are previously determined for each mineral which is to be quantitatively measured. Ratios of the highest intensity peak of each mineral to be quantified in the sample and the highest intensity peak of a reference mineral contained in the sample are used to calculate sample composition.

  4. Quantitative determination of mineral composition by powder x-ray diffraction

    DOEpatents

    Pawloski, G.A.

    1984-08-10

    An external standard intensity ratio method is used for quantitatively determining mineralogic compositions of samples by x-ray diffraction. The method uses ratios of x-ray intensity peaks from a single run. Constants are previously determined for each mineral which is to be quantitatively measured. Ratios of the highest intensity peak of each mineral to be quantified in the sample and the highest intensity peak of a reference mineral contained in the sample are used to calculate sample composition.

  5. Osage oil: Mineral law, murder, mayhem, and manipulation

    SciTech Connect

    Strickland, R.

    1995-12-31

    The greatest of the 20th century Osage chiefs, Fred Lookout, feared what the rich oil bonanza under tribal lands would do to his people. He forsaw that oil wealth could turn into a curse as well as a blessing, and it was both. The story of Osage oil is a case history in the failure of law, the failure of Indian policy and the struggle for survival of the indomitable spirit of a great Native people force to deal with both the curse and the blessing of black gold. This article examines law and policy as seen in Osage oil regulation, outlining the legal controls of the land and mineral regulatory system and briefly exploring the breakdowns of the system.

  6. MINER{nu}A, a Neutrino--Nucleus Interaction Experiment

    SciTech Connect

    Solano Salinas, C. J.; Chamorro, A.; Romero, C.

    2007-10-26

    With the fantastic results of KamLAND and SNO for neutrino physics, a new generation of neutrino experiments are being designed and build, specially to study the neutrino oscillations to resolve most of the incognita still we have in the neutrino physics. At FERMILAB we have the experiments MINOS and, in a near future, NO{nu}A, to study this kind of oscillations. One big problem these experiments will have is the lack of a good knowledge of the Physics of neutrino interactions with matter, and this will generate big systematic errors. MINER{nu}A, also at FERMILAB, will cover this space studying with high statistics and great precision the neutrino--nucleus interactions.

  7. Catalytic effects of minerals on NOx emission from coal combustion

    SciTech Connect

    Yao, M.Y.; Che, D.F.

    2007-07-01

    The catalytic effects of inherent mineral matters on NOx emissions from coal combustion have been investigated by a thermo-gravimetric analyzer (TGA) equipped with a gas analyzer. The effect of demineralization and the individual effect of Na, K, Ca, Mg, and Fe on the formation of NOx are studied as well as the combined catalytic effects of Ca + Na and Ca + Ti. Demineralization causes more Fuel-N to retain in the char, and reduction of NOx mostly. But the mechanistic effect on NOx formation varies from coal to coal. Ca and Mg promote NOx emission. Na, K, Fe suppress NOx formation to different extents. The effect of transition element Fe is the most obvious. The combination of Ca + Na and Ca + Ti can realize the simultaneous control of sulfur dioxide and nitrogen oxides emissions.

  8. Utilization of coal-associated minerals. Final report

    SciTech Connect

    Slonaker, J. F.; Akers, D. J.; Alderman, J. K.

    1980-01-01

    Under contract number DE-AS21-77ET10533 with the US-DOE several methods of utilizing coal associated by-products were examined for potential commercial use. Such use could transform a costly waste disposal situation into new materials for further use and could provide incentive for the adoption of new coal utilization processes. Several utilization processes appear to have merit and are recommended for further study. Each process is discussed separately in the text of this report. Common coal cleaning processes were also examined to determine the effect of such processes on the composition of by-products. Data obtained in this portion of the research effort are reported in the Appendix. Information of this type is required before utilization processes can be considered. A knowledge of the mineral composition of these materials is also required before even simple disposal methods can be considered.

  9. Plutonium Oxidation and Subsequent Reduction by Mn (IV) Minerals

    SciTech Connect

    KAPLAN, DANIEL

    2005-09-13

    Plutonium sorbed to rock tuff was preferentially associated with manganese oxides. On tuff and synthetic pyrolusite (Mn{sup IV}O{sub 2}), Pu(IV) or Pu(V) was initially oxidized, but over time Pu(IV) became the predominant oxidation state of sorbed Pu. Reduction of Pu(V/VI), even on non-oxidizing surfaces, is proposed to result from a lower Gibbs free energy of the hydrolyzed Pu(IV) surface species versus that of the Pu(V) or Pu(VI) surface species. This work suggests that despite initial oxidation of sorbed Pu by oxidizing surfaces to more soluble forms, the less mobile form of Pu, Pu(IV), will dominate Pu solid phase speciation during long term geologic storage. The safe design of a radioactive waste or spent nuclear fuel geologic repository requires a risk assessment of radionuclides that may potentially be released into the surrounding environment. Geochemical knowledge of the radionuclide and the surrounding environment is required for predicting subsurface fate and transport. Although difficult even in simple systems, this task grows increasingly complicated for constituents, like Pu, that exhibit complex environmental chemistries. The environmental behavior of Pu can be influenced by complexation, precipitation, adsorption, colloid formation, and oxidation/reduction (redox) reactions (1-3). To predict the environmental mobility of Pu, the most important of these factors is Pu oxidation state. This is because Pu(IV) is generally 2 to 3 orders of magnitude less mobile than Pu(V) in most environments (4). Further complicating matters, Pu commonly exists simultaneously in several oxidation states (5, 6). Choppin (7) reported Pu may exist as Pu(IV), Pu(V), or Pu(VI) oxic natural groundwaters. It is generally accepted that plutonium associated with suspended particulate matter is predominantly Pu(IV) (8-10), whereas Pu in the aqueous phase is predominantly Pu(V) (2, 11-13). The influence of the character of Mn-containing minerals expected to be found in subsurface

  10. Effective flocculation of fine mineral suspensions using Moringa oleifera seeds

    SciTech Connect

    Pickett, T.M.

    1995-12-31

    The purpose of this research was to investigate the feasibility of using Moringa oleifera seeds, or the active components of the seeds, in the clarification of waters containing suspended mineral fines. In comparative testing using a hematite suspension, the flocculating activity of Moringa oleifera seeds was better than alum. Twenty milligrams of seed powder was sufficient to clarify the hematite to near zero turbidity, while the same amount of alum had a minimal effect on turbidity. Extracts were prepared from the seeds in an attempt to separate the proteins. A crude protein extract was enriched by lowering the pH to 6.0. Only 0.08 mg/L of the enriched extract was required to flocculate a minusil suspension. Environmentally friendly protein flocculants could theoretically be produced and enhanced with recombinant DNA techniques as an alternative to chemical flocculants currently used in water treatment.

  11. Fundamental study of CO2-H2O-mineral interactions for carbon...

    Office of Scientific and Technical Information (OSTI)

    E.; Wang, Yifeng; Matteo, Edward N.; Meserole, Stephen P.; Tallant, David Robert In the supercritical CO2-water-mineral systems relevant to subsurface CO2 sequestration,...

  12. The role of mineral aerosol as a reactive surface in the global...

    Office of Scientific and Technical Information (OSTI)

    Dust storms have become a distinct feature in many regions around the globe, including east Asia, west Africa, and South America. The mineral aerosols, uplifted in these storms, ...

  13. Composition and method for self-assembly and mineralization of peptide-amphiphiles

    DOEpatents

    Stupp, Samuel I.; Beniash, Elia; Hartgerink, Jeffrey D.

    2012-02-28

    The present invention is directed to a composition useful for making homogeneously mineralized self assembled peptide-amphiphile nanofibers and nanofiber gels. The composition is generally a solution comprised of a positively or negatively charged peptide-amphiphile and a like signed ion from the mineral. Mixing this solution with a second solution containing a dissolved counter-ion of the mineral and/or a second oppositely charged peptide amphiphile, results in the rapid self assembly of the peptide-amphiphiles into a nanofiber gel and templated mineralization of the ions. Templated mineralization of the initially dissolved mineral cations and anions in the mixture occurs with preferential orientation of the mineral crystals along the fiber surfaces within the nanofiber gel. One advantage of the present invention is that it results in homogenous growth of the mineral throughout the nanofiber gel. Another advantage of the present invention is that the nanofiber gel formation and mineralization reactions occur in a single mixing step and under substantially neutral or physiological pH conditions. These homogeneous nanostructured composite materials are useful for medical applications especially the regeneration of damaged bone in mammals. This invention is directed to the synthesis of peptide-amphiphiles with more than one amphiphilic moment and to supramolecular compositions comprised of such multi-dimensional peptide-amphiphiles. Supramolecular compositions can be formed by self assembly of multi-dimensional peptide-amphiphiles by mixing them with a solution comprising a monovalent cation.

  14. Composition and method for self-assembly and mineralization of peptide amphiphiles

    DOEpatents

    Stupp, Samuel I.; Beniash, Elia; Hartgerink, Jeffrey D.

    2009-06-30

    The present invention is directed to a composition useful for making homogeneously mineralized self assembled peptide-amphiphile nanofibers and nanofiber gels. The composition is generally a solution comprised of a positively or negatively charged peptide-amphiphile and a like signed ion from the mineral. Mixing this solution with a second solution containing a dissolved counter-ion of the mineral and/or a second oppositely charged peptide amphiphile, results in the rapid self assembly of the peptide-amphiphiles into a nanofiber gel and templated mineralization of the ions. Templated mineralization of the initially dissolved mineral cations and anions in the mixture occurs with preferential orientation of the mineral crystals along the fiber surfaces within the nanofiber gel. One advantage of the present invention is that it results in homogenous growth of the mineral throughout the nanofiber gel. Another advantage of the present invention is that the nanofiber gel formation and mineralization reactions occur in a single mixing step and under substantially neutral or physiological pH conditions. These homogeneous nanostructured composite materials are useful for medical applications especially the regeneration of damaged bone in mammals. This invention is directed to the synthesis of peptide-amphiphiles with more than one amphiphilic moment and to supramolecular compositions comprised of such multi-dimensional peptide-amphiphiles. Supramolecular compositions can be formed by self assembly of multi-dimensional peptide-amphiphiles by mixing them with a solution comprising a monovalent cation.

  15. Method for the Production of Mineral Wool and Iron from Serpentine...

    U.S. Department of Energy (DOE) - all webpages (Extended Search)

    fiber in collector Mineral wool fiber in collector Blowing fiber Blowing fiber Technology Marketing Summary This invention discloses a method to fabricate a product that has the...

  16. Uranium mineralization in fluorine-enriched volcanic rocks

    SciTech Connect

    Burt, D.M.; Sheridan, M.F.; Bikun, J.; Christiansen, E.; Correa, B.; Murphy, B.; Self, S.

    1980-09-01

    Several uranium and other lithophile element deposits are located within or adjacent to small middle to late Cenozoic, fluorine-rich rhyolitic dome complexes. Examples studied include Spor Mountain, Utah (Be-U-F), the Honeycomb Hills, Utah (Be-U), the Wah Wah Mountains, Utah (U-F), and the Black Range-Sierra Cuchillo, New Mexico (Sn-Be-W-F). The formation of these and similar deposits begins with the emplacement of a rhyolitic magma, enriched in lithophile metals and complexing fluorine, that rises to a shallow crustal level, where its roof zone may become further enriched in volatiles and the ore elements. During initial explosive volcanic activity, aprons of lithicrich tuffs are erupted around the vents. These early pyroclastic deposits commonly host the mineralization, due to their initial enrichment in the lithophile elements, their permeability, and the reactivity of their foreign lithic inclusions (particularly carbonate rocks). The pyroclastics are capped and preserved by thick topaz rhyolite domes and flows that can serve as a source of heat and of additional quantities of ore elements. Devitrification, vapor-phase crystallization, or fumarolic alteration may free the ore elements from the glassy matrix and place them in a form readily leached by percolating meteoric waters. Heat from the rhyolitic sheets drives such waters through the system, generally into and up the vents and out through the early tuffs. Secondary alteration zones (K-feldspar, sericite, silica, clays, fluorite, carbonate, and zeolites) and economic mineral concentrations may form in response to this low temperature (less than 200 C) circulation. After cooling, meteoric water continues to migrate through the system, modifying the distribution and concentration of the ore elements (especially uranium).

  17. Magnetic properties of CeFe11-xCoxTi with ThMn12 structure

    SciTech Connect

    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.

  18. High pressures and the Kondo gap in Ce{sub 3}Bi{sub 4}Pt{sub 3}

    SciTech Connect

    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}

  19. Low pressure CO₂ hydrogenation to methanol over gold nanoparticles activated on a CeOx/TiO₂ interface

    DOE PAGES [OSTI]

    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

  20. Response of Cs2LiYCl6:Ce (CLYC) to High Energy Protons

    SciTech Connect

    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.

  1. Coadsorbed species explain the mechanism of methanol temperature-desorption on CeO2(111)

    DOE PAGES [OSTI]

    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

  2. Pulse-shape discrimination and energy quenching of alpha particles in Cs2LiLaBr6:Ce3+

    DOE PAGES [OSTI]

    Mesick, Katherine Elizabeth; Coupland, Daniel David S.; Stonehill, Laura Catherine

    2016-10-19

    Cs2LiLaBr6:Ce3+ (CLLB) is an elpasolite scintillator that offers excellent linearity and gamma-ray energy resolution and sensitivity to thermal neutrons with the ability to perform pulse-shape discrimination (PSD) to distinguish gammas and neutrons. Our investigation of CLLB has indicated the presence of intrinsic radioactive alpha background that we have determined to be from actinium contamination of the lanthanum component. We measured the pulse shapes for gamma, thermal neutron, and alpha events and determined that PSD can be performed to separate the alpha background with a moderate figure of merit of 0.98. Here, we also measured the electron-equivalent-energy of the alpha particlesmore » in CLLB and simulated the intrinsic alpha background from 227Ac to determine the quenching factor of the alphas.« less

  3. Crystal Chemistry and Luminescence of Ce3+ -Doped Lu2CaMg2(Si,Ge)3O12 and Its Use in LED Based Lighting

    SciTech Connect

    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.

  4. Inverse magnetocaloric effect in Ce(Fe{sub 0.96}Ru{sub 0.04}){sub 2}: Effect of fast neutron irradiation

    SciTech Connect

    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.

  5. Data:F3d511d9-6321-49ce-b5b2-a0d21fd28d52 | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    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....

  6. Mechanistic Insights of Ethanol Steam Reforming over Ni–CeO x (111): The Importance of Hydroxyl Groups for Suppressing Coke Formation

    DOE PAGES [OSTI]

    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

  7. High Catalytic Activity of Au/CeOx/TiO2(110) Controlled by the Nature of the Mixed Metal Oxide at the Nanometer Level

    SciTech Connect

    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.

  8. Mechanistic insights of ethanol steam reforming over Ni-CeOx(111): The importance of hydroxyl groups for suppressing coke formation

    DOE PAGES [OSTI]

    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

  9. UV absorption properties of ceria-modified compositions within the fluorite-type solid solution CeO{sub 2}-Y{sub 6}WO{sub 12}

    SciTech Connect

    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.

  10. Electronic Structure of CeFeAsO1-xFx (x=0, 0.11/x=0.12) compounds

    SciTech Connect

    Bondino, F.; Magnano, E.; Booth, C. H.; Offi, F.; Panaccione, G.; Malvestuto, M.; Paolicelli, G.; Simonelli, L.; Parmigiani, F.; McGuire, M. A.; Sefat, A. S.; Sales, B. C.; Jin, R.; Vilmercati, P.; Mandrus, D.; Singh, D. J.; Mannella, N.

    2011-01-25

    We report an extensive study on the intrinsic bulk electronic structure of the high-temperature superconductor CeFeAsO{sub 0.89}F{sub 0.11} and its parent compound CeFeAsO by soft and hard x-ray photoemission, x-ray absorption and soft-x-ray emission spectroscopies. The complementary surface/bulk probing depth, and the elemental and chemical sensitivity of these techniques allows resolving the intrinsic electronic structure of each element and correlating it with the local structure, which has been probed by extended-x-ray absorption fine structure spectroscopy. The measurements indicate a predominant 4f{sup 1} (i.e. Ce{sup 3+}) initial state configuration for Cerium and an effective valence-band-to-4f charge-transfer screening of the core hole. The spectra also reveal the presence of a small Ce f{sup 0} initial state configuration, which we assign to the occurrence of an intermediate valence state. The data reveal a reasonably good agreement with the partial density of states as obtained in standard density functional calculations over a large energy range. Implications for the electronic structure of these materials are discussed.

  11. Mechanistic Insights of Ethanol Steam Reforming over Ni–CeO x (111): The Importance of Hydroxyl Groups for Suppressing Coke Formation

    SciTech Connect

    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.

  12. 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

    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.

  13. A Novel Approach to Experimental Studies of Mineral Dissolution Kinetics

    SciTech Connect

    Chen Zhu

    2006-08-31

    Currently, DOE is conducting pilot CO{sub 2} injection tests to evaluate the concept of geological sequestration. One strategy that potentially enhances CO{sub 2} solubility and reduces the risk of CO{sub 2} leak back to the surface is dissolution of indigenous minerals in the geological formation and precipitation of secondary carbonate phases, which increases the brine pH and immobilizes CO{sub 2}. Clearly, the rates at which these dissolution and precipitation reactions occur directly determine the efficiency of this strategy. However, one of the fundamental problems in modern geochemistry is the persistent two to five orders of magnitude discrepancy between laboratory measured and field derived feldspar dissolution rates. To date, there is no real guidance as to how to predict silicate reaction rates for use in quantitative models. Current models for assessment of geological carbon sequestration have generally opted to use laboratory rates, in spite of the dearth of such data for compositionally complex systems, and the persistent disconnect between laboratory and field applications. Therefore, a firm scientific basis for predicting silicate reaction kinetics in CO2 injected geological formations is urgently needed to assure the reliability of the geochemical models used for the assessments of carbon sequestration strategies. The funded experimental and theoretical study attempts to resolve this outstanding scientific issue by novel experimental design and theoretical interpretation to measure silicate dissolution rates and iron carbonate precipitation rates at conditions pertinent to geological carbon sequestration. In the second year of the project, we completed CO{sub 2}-Navajo sandstone interaction batch and flow-through experiments and a Navajo sandstone dissolution experiment without the presence of CO{sub 2} at 200 C and 250-300 bars, and initiated dawsonite dissolution and solubility experiments. We also performed additional 5-day experiments at the

  14. Regulatory approaches to reduce human health risks associated with exposures to mineral fibers

    SciTech Connect

    Vu, V.T.

    1993-12-31

    This paper provides an overview of past and current regulatory activities relating to mineral fibers. Various approaches have been utilized by the federal agencies in the USA to reduce health risks associated with exposures to asbestos and other mineral fibers. These approaches are generally in the form of regulations, enforceable consent orders, negotiated voluntary actions, advisories, hazard communication, and guidance documents. 40 refs.

  15. An epidemiological study of salt miners in diesel and nondiesel mines

    SciTech Connect

    Gamble, J.; Jones, W.; Hudak, J.

    1983-01-01

    A cross-sectional study of 5 NaCl mines and 259 miners addressed the following questions: 1) Is there an association of increased respiratory symptoms, radiographic findings, and reduced pulmonary function with exposure to nitrogen dioxide (NO2) and/or respirable particulate (RP) among these miners. 2) Is there increased morbidity of these miners compared to other working populations. Personal samples of NO2 and respirable particulate for jobs in each mine were used to estimate cumulative exposure. NO2 is used as a surrogate measure of diesel exposure. Cough was associated with age and smoking, dyspnea with age; neither symptom was associated with exposure (years worked, estimated cumulative NO2 or RP exposure). Phlegm was associated with age, smoking, and exposure. Reduced pulmonary function (FVC, FEV1, peak, flow, FEF50, FEF75) showed no association with exposure. There was one case of small rounded and one case of small irregular opacities; pneumoconiosis was not analyzed further. Compared to underground coal miners, above ground coal miners, potash miners, and nonmining workers, the study population after adjustment for age and smoking generally showed no increased prevalence of cough, phlegm, dyspnea, or obstruction (FEV1/FVC less than 0.7). Obstruction in younger salt miners and phlegm in older salt miners was elevated compared to nonmining workers. Mean predicted pulmonary function was reduced 2-4% for FEV1 and FVC, 7-13% for FEF50, and 18-22% for FEF75 below all comparison populations.

  16. Applications of scanning electron microscopy to the study of mineral matter in peat

    SciTech Connect

    Raymond, R. Jr.; Andrejko, M.J.; Bardin, S.W.

    1983-01-01

    Scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) have been used for in situ analysis of minerals in peats by combining methods for producing oriented microtome sections of peat with methods for critical point drying. The combined technique allows SEM analysis of the inorganic components and their associated botanical constituents, along with petrographic identification of the botanical constituents. In peat deposits with abundant fluvial- or marine-derived minerals, one may use the above technique and/or medium- or low-temperature ashing followed by x-ray diffraction to readily identify the various mineral components. However, in some freshwater environments the scarcity of non-silica minerals makes the above techniques impractical. By separating the inorganic residues from the peat, one can isolate the non-silica mineral matter in the SEM for analysis by EDS. Furthermore, such separation allows SEM analysis of features and textures of both silica and non-silica mineral particles that might otherwise be unidentifiable. Results indicate the occurrence of detritial minerals in both Okefenokee and Snuggedy Swamp peats, the presence of authigenic or diagenetic minerals growing within peats, and dissolution features on freshwater sponge spicules that may account for the absence of spicules in Tertiary lignites.

  17. Water–gas shift reaction over gold nanoparticles dispersed on nanostructured CeOx–TiO2(110) surfaces: Effects of high ceria coverage

    DOE PAGES [OSTI]

    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. Degradation of dome cutting minerals in Hanford waste

    SciTech Connect

    Reynolds, Jacob G.; Huber, Heinz J.; Cooke, Gary A.

    2013-01-11

    At the Hanford Tank Farms, recent changes in retrieval technology require cutting new risers in several single-shell tanks. The Hanford Tank Farm Operator is using water jet technology with abrasive silicate minerals such as garnet or olivine to cut through the concrete and rebar dome. The abrasiveness of these minerals, which become part of the high-level waste stream, may enhance the erosion of waste processing equipment. However, garnet and olivine are not thermodynamically stable in Hanford waste, slowly degrading over time. How likely these materials are to dissolve completely in the waste before the waste is processed in the Waste Treatment and Immobilization Plant can be evaluated using theoretical analysis for olivine and collected direct experimental evidence for garnet. Based on an extensive literature study, a large number of primary silicates decompose into sodalite and cancrinite when exposed to Hanford waste. Given sufficient time, the sodalite also degrades into cancrinite. Even though cancrinite has not been directly added to any Hanford tanks during process times, it is the most common silicate observed in current Hanford waste. By analogy, olivine and garnet are expected to ultimately also decompose into cancrinite. Garnet used in a concrete cutting demonstration was immersed in a simulated supernate representing the estimated composition of the liquid retrieving waste from Hanford tank 241-C-107 at both ambient and elevated temperatures. This simulant was amended with extra NaOH to determine if adding caustic would help enhance the degradation rate of garnet. The results showed that the garnet degradation rate was highest at the highest NaOH concentration and temperature. At the end of 12 weeks, however, the garnet grains were mostly intact, even when immersed in 2 molar NaOH at 80 deg C. Cancrinite was identified as the degradation product on the surface of the garnet grains. In the case of olivine, the rate of degradation in the high-pH regimes

  19. Analysis of stream sediment reconnaissance data for mineral resources from the Montrose NTMS Quadrangle, Colorado

    SciTech Connect

    Beyth, M.; Broxton, D.; McInteer, C.; Averett, W.R.; Stablein, N.K.

    1980-06-01

    Multivariate statistical analysis to support the National Uranium Resource Evaluation and to evaluate strategic and other commercially important mineral resources was carried out on Hydrogeochemical and Stream Sediment Reconnaissance data from the Montrose quadrangle, Colorado. The analysis suggests that: (1) the southern Colorado Mineral Belt is an area favorable for uranium mineral occurrences; (2) carnotite-type occurrences are likely in the nose of the Gunnison Uplift; (3) uranium mineral occurrences may be present along the western and northern margins of the West Elk crater; (4) a base-metal mineralized area is associated with the Uncompahgre Uplift; and (5) uranium and base metals are associated in some areas, and both are often controlled by faults trending west-northwest and north.

  20. Taxation of unmined minerals; Current developments in the Commonwealth of Kentucky

    SciTech Connect

    Bremberg, B.P. )

    1989-01-01

    This paper reports on the Kentucky Revenue Cabinet which began implementing its controversial unmined minerals tax program. The Revenue Cabinet should complete its first annual assessment under this program in December, 1989. The Revenue Cabinet's initial efforts to collect basic data concerning the Commonwealth's coal bearing lands has yielded data coverage for 5 million of Kentucky's 10 million acres of coal lands. Approximately 1000 detailed information returns have been filed. The returns will be used to help create an undeveloped mineral reserves inventory, determine mineral ownership, and value mineral reserves. This new program is run by the Revenue Cabinet's Mineral Valuation Section, under the Division of Technical Support, Department of Property Taxation. It has been in business since September of 1988.

  1. Future US energy supply: constraints by nonfuel mineral resources

    SciTech Connect

    Goeller, H.E.

    1980-12-01

    A continuing supply of energy for the domestic scene is of vital concern to our nation and is determined to a significant extent by the availability of sufficient nonfuel resources used in the production and utilization of various forms of energy. This report, taking a very comprehensive view, first establishes the current energy-related requirements for the various elements and mineral products. It then assesses domestic and world reserves and resources for each nonrenewable resource and determines a ranking of impending domestic scarcities by using resource-to-demand ratios. Special problems on by-products production are noted, followed by a discussion on import dependency. The roles of recycle and substitution are then assessed, and the possibilities for synthesis of nonelement commodities are reviewed. Detailed requirements for the more widely used materials in a large number of energy supply systems are then provided, followed by newer future requirements for more advanced energy systems anticipated to be in widespread use in the next century. Finally, the various problems associated with 16 elements deemed most likely to become scarce within the next 50 years are resummarized, and the general conclusions of this study are provided.

  2. Metals attenuation in minerally-enhanced slurry walls

    SciTech Connect

    Evans, J.C.; Prince, M.J.; Adams, T.L.

    1997-12-31

    In current practice, a soil-bentonite slurry trench cutoff wall is a mixture of water, soil, and bentonite that is designed to serve as a passive barrier to ground water and contaminant transport. This study evaluated the transformation of a passive slurry trench cutoff wall barrier to an active barrier system. Conventional soil-bentonite vertical barriers presently serve as passive barriers to contaminated ground water. An active barrier will not only fulfill the functions of the present passive barrier system, but also retard contaminant transport by adsorptive processes. Attapulgite, Na-chabazite, and Ca-chabazite were added to {open_quotes}activate{close_quotes} the conventional soil-bentonite backfill. Batch extraction tests were performed to determine the partitioning coefficients of cadmium and zinc between the liquid and solid phase when in contact with the backfill mixes. Batch extraction and mathematical modeling results demonstrate the ability of an active barrier to retard the transport of cadmium and zinc. The reactivity of the soil-bentonite vertical barrier depends heavily on the inorganic being adsorbed. The reactivity of the barrier also depends on the adsorptive capabilities of the clay minerals added to the conventional soil-bentonite vertical barrier. The results of laboratory studies suggest that passive barrier systems can be transformed to active systems. Further, the data suggests that although conventional soil-bentonite vertical barriers are presently designed as passive barriers, they already have adsorptive capacity associated with active barriers.

  3. Electrical properties of dispersions of graphene in mineral oil

    SciTech Connect

    Monteiro, O. R.

    2014-02-03

    Dispersions of graphene in mineral oil have been prepared and electrical conductivity and permittivity have been measured. The direct current (DC) conductivity of the dispersions depends on the surface characteristics of the graphene platelets and followed a percolation model with a percolation threshold ranging from 0.05 to 0.1?wt. %. The difference in DC conductivities can be attributed to different states of aggregation of the graphene platelets and to the inter-particle electron transfer, which is affected by the surface radicals. The frequency-dependent conductivity (?(?)) and permittivity (?(?)) were also measured. The conductivity of dispersions with particle contents much greater than the percolation threshold remains constant and equal to the DC conductivity at low frequencies ? with and followed a power-law ?(?)???{sup s} dependence at very high frequencies with s?0.9. For dispersions with graphene concentration near the percolation threshold, a third regime was displayed at intermediate frequencies indicative of interfacial polarization consistent with Maxwell-Wagner effect typically observed in mixtures of two (or more) phases with very distinct electrical and dielectric properties.

  4. Geothermal Geodatabase for Wagon Wheel Hot Springs, Mineral County, Colorado

    DOE Data Explorer

    Zehner, Richard

    2012-11-01

    Geothermal Geodatabase for Wagon Wheel Hot Springs, Mineral County, Colorado By Richard “Rick” Zehner Geothermal Development Associates Reno Nevada USA 775.737.7806 rzehner@gdareno.com For Flint Geothermal LLC, Denver Colorado Part of DOE Grant EE0002828 2013 This is an ESRI geodatabase version 10, together with an ESRI MXD file version 10.2 Data is in UTM Zone 13 NAD27 projection North boundary: approximately 4,189,000 South boundary: approximately 4,170,000 West boundary: approximately 330,000 East boundary: approximately 351,000 This geodatabase was built to cover several geothermal targets developed by Flint Geothermal in 2012 during a search for high-temperature systems that could be exploited for electric power development. Several of the thermal springs at Wagon Wheel Gap have geochemistry and geothermometry values indicative of high-temperature systems. The datasets in the geodatabase are a mixture of public domain data as well as data collected by Flint Geothermal, now being made public. It is assumed that the user has internet access, for the mxd file accesses ESRI’s GIS servers. Datasets include: 1. Results of reconnaissance shallow (2 meter) temperature surveys 2. Air photo lineaments 3. Groundwater geochemistry 4. Power lines 5. Georeferenced geologic map of Routt County 6. Various 1:24,000 scale topographic maps

  5. Substitution effect on the magnetic and transport properties of CeNi{sub 0.8−x}Mn{sub x}Bi{sub 2}

    SciTech Connect

    Kim, Soo-Whan; Lee, Kyujoon; Jung, Myung-Hwa; Adroja, D. T.; Demmel, F.; Taylor, J. W.

    2014-08-21

    We report the results of Mn substitution for Ni in CeNi{sub 0.8}Bi{sub 2} (i.e., CeNi{sub 0.8−x}Mn{sub x}Bi{sub 2}). All the samples have an antiferromagnetic ordered state below T{sub N} = 5.0 K due to localized 4f-magnetic moment on the Ce ions. Besides this antiferromagnetic ordering caused by Ce, the magnetic and transport properties are abruptly changed with increasing Mn contents at the boundary composition of x = 0.4. The magnetic state is changed into a ferromagnetic state around 200 K for x > 0.4, where the electrical resistivity is strongly suppressed to become simple metallic. These results of ferromagnetism and metallicity can be explained by the double exchange mechanism, rather than the simple picture of Doniach phase diagram. The mixed valence states of Ni and Mn ions are confirmed by X-ray photoelectron spectroscopy. For x ≤ 0.4, the initial Ni{sup 3+} state gradually changes to the Ni{sup 2+} state with increasing x up to 0.4. On further increase of x > 0.4, the Ni{sup 2+} state is replaced by the Mn{sup 2+} state, which gradually changes to the final Mn{sup 3+} state. We also present an inelastic neutron scattering (INS) measurements on CeNi{sub 0.8}Bi{sub 2} (i.e., x = 0) between 1.2 and 12 K. The high energy INS study reveals the presence of two well-defined crystal electric field (CEF) excitations near 9 meV and 19 meV at 1.2 K and 6 K, while the low energy INS study reveals the presence of quasielastic scattering above 4 K. We will discuss our INS results of CeNi{sub 0.8}Bi{sub 2} based on the CEF model.

  6. Bone mineral density and blood metals in premenopausal women

    SciTech Connect

    Pollack, A.Z.; Mumford, S.L.; Wactawski-Wende, J.; Yeung, E.; Mendola, P.; Mattison, D.R.; Schisterman, E.F.

    2013-01-15

    Exposure to metals, specifically cadmium, lead, and mercury, is widespread and is associated with reduced bone mineral density (BMD) in older populations, but the associations among premenopausal women are unclear. Therefore, we evaluated the relationship between these metals in blood and BMD (whole body, total hip, lumbar spine, and non-dominant wrist) quantified by dual energy X-ray absorptiometry in 248 premenopausal women, aged 18-44. Participants were of normal body mass index (mean BMI 24.1), young (mean age 27.4), 60% were white, 20% non-Hispanic black, 15% Asian, and 6% other race group, and were from the Buffalo, New York region. The median (interquartile range) level of cadmium was 0.30 {mu}g/l (0.19-0.43), of lead was 0.86 {mu}g/dl (0.68-1.20), and of mercury was 1.10 {mu}g/l (0.58-2.00). BMD was treated both as a continuous variable in linear regression and dichotomized at the 10th percentile for logistic regression analyses. Mercury was associated with reduced odds of decreased lumbar spine BMD (0.66, 95% confidence interval: 0.44, 0.99), but overall, metals at environmentally relevant levels of exposure were not associated with reduced BMD in this population of healthy, reproductive-aged women. Further research is needed to determine if the blood levels of cadmium, lead, and mercury in this population are sufficiently low that there is no substantive impact on bone, or if effects on bone can be expected only at older ages.

  7. Micro-Analysis of Actinide Minerals for Nuclear Forensics and Treaty Verification

    SciTech Connect

    M. Morey, M. Manard, R. Russo, G. Havrilla

    2012-03-22

    Micro-Raman spectroscopy has been demonstrated to be a viable tool for nondestructive determination of the crystal phase of relevant minerals. Collecting spectra on particles down to 5 microns in size was completed. Some minerals studied were weak scatterers and were better studied with the other techniques. A decent graphical software package should easily be able to compare collected spectra to a spectral library as well as subtract out matrix vibration peaks. Due to the success and unequivocal determination of the most common mineral false positive (zircon), it is clear that Raman has a future for complementary, rapid determination of unknown particulate samples containing actinides.

  8. Utilization of coal associated minerals. Quarterly report No. 11, April 1-June 30, 1980

    SciTech Connect

    Slonaker, J. F.; Akers, D. J.; Alderman, J. K.

    1980-08-29

    The purpose of this research program is to examine the effects of coal mineral materials on coal waste by-product utilization and to investigate new and improved methods for the utilization of waste by-products from cleaning, combustion and conversion processing of coal. The intermediate objectives include: (1) the examination of the effects of cleaning, gasification and combustion on coal mineral materials; and (2) the changes which occur in the coal wastes as a result of both form and distribution of mineral materials in feed coals in conjunction with the coal treatment effects resulting from coal cleaning or either gasification or combustion.

  9. Principal deposits of strategic and critical minerals in Arizona Special pub

    SciTech Connect

    Sawyer, M.B.; Gurmendi, A.C.; Daley, M.R.; Howell, S.B.

    1993-01-01

    The Bureau of Mines publication provides locational, geological, and operational data in abstracted format for about 200 mineral deposits representing 16 commodities that are considered to be important to the economies of the United States and Arizona. Each of these commodities is discussed in terms of its history, physical and chemical properties, uses, and occurrence in Arizona. Institutional and infrastructural factors that affect mineral development in Arizona are also presented. These factors include regulation, taxation, and availability of utilities, transportation, and mineral processing facilities.

  10. Low temperature specific heat of the Kondo-semimetal CeNiSn in zero and applied magnetic fields

    SciTech Connect

    Brueckl, A.; Neumaier, K.; Einzel, D.; Andres, K.; Flaschin, S.; Kalvius, G.M.; Nakamoto, G.; Takabatake, T.

    1999-06-01

    The specific heat of several CeNiSn single crystals of various purity has been measured in the temperature range from 25 mK to 5 K and in magnetic fields from zero to 7 Tesla. At very low temperatures (below {approximately} 200 mK) the specific heat is found to vary linearly with temperature (C = {gamma}T), the coefficient {gamma} decreasing with increasing purity. Above 200 mK, the specific heat is well described as the sum of a linear and a quadratic term. An applied magnetic field affects mostly the linear term, which first slightly decreases, then strongly increases with field. In magnetic fields, a nuclear hyperfine specific heat contribution is superimposed, which is due mostly to the bare Zeeman-splitting of the {sup 115}Sn, {sup 117}Sn, {sup 119}Sn nuclei (all with spin I = 1/2 and with abundances of 0.35, 7.61, and 8.58% respectively) in the externally applied field. The results on the specific heat at very low temperatures in applied fields fit into the model of an enhanced (heavy-fermion type) density of states which is modified by coherent antiferromagnetic fluctuations into a V-shaped density of states at the Fermi energy.

  11. Nodal to nodeless superconducting energy gap structure change concomitant with Fermi surface reconstruction in the heavy-fermion CeCoIn?

    DOE PAGES [OSTI]

    Kim, Hyunsoo; Petrovic, C.; Tanatar, M. A.; Flint, R.; Hu, Rongwei; White, B. D.; Lum, I. K.; Maple, M. B.; Prozorov, R.

    2015-01-15

    The London penetration depth ?(T) was measured in single crystals of Ce1xRxCoIn?, R=La, Nd, and Yb down to Tmin ? 50 mK (Tc/Tmin ~50) using a tunnel-diode resonator. In the cleanest samples ??(T) is best described by the power law, ??(T) ? Tn, with n ~ 1, consistent with line nodes. Substitutions of Ce with La, Nd, and Yb lead to similar monotonic suppressions of Tc, however, the effects on ??(T) differ. While La and Nd dopings lead to increase of the exponent n and saturation at n ~ 2, as expected for a dirty nodal superconductor, Yb doping leadsmoreto n > 3, suggesting a change from nodal to nodeless superconductivity. This superconducting gap structure change happens in the same doping range where changes of the Fermi surface topology were reported, implying that the nodal structure and Fermi surface topology are closely linked.less

  12. Lu.sub.1-xI.sub.3:Ce.sub.x--a scintillator for gamma ray spectroscopy and time-of-flight PET

    DOEpatents

    Shah, Kanai S.

    2007-02-06

    The present invention concerns very fast scintillator materials comprising 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. The timing resolution of the scintillators of the present invention provide compositions capable of resolving the position of an annihilation event within a portion of a human body cross-section.

  13. Powder preparation and UV absorption properties of selected compositions in the CeO{sub 2}-Y{sub 2}O{sub 3} system

    SciTech Connect

    Tessier, Franck Chevire, Francois; Munoz, Francisco; Merdrignac-Conanec, Odile; Marchand, Roger; Bouchard, Michel; Colbeau-Justin, Christophe

    2008-05-15

    Several approaches have been investigated to prepare fluorite-type compositions within the (1-x) CeO{sub 2}-xYO{sub 1.5} system. The optical properties of the resulting modified-ceria materials have been characterized in order to evaluate their potential abilities as inorganic UV absorbers. Diffuse reflectance analyses reveal a strong optical absorption between 390 and 400 nm for all substituted compositions and the spectral selectivities are estimated suitable for the targeted application. Additionally, time resolved microwave conductivity (TRMC) and phenol photodegradation analyses do not indicate any photocalatytic activity for these compositions. Aqueous colloidal suspensions of the Ce{sub 0.7}Y{sub 0.3}O{sub 1.85} UV absorber have been carried out. - Graphical abstract: Comparison between diffuse reflectance spectra of ceria (x=0) and yttrium modified ceria (x=0.3)

  14. Electrochemical Study on the Electrodeposition of U, Nd, Ce, La and Y on a Liquid Cadmium Cathode in a LiCl-KCl Eutectic Salt

    SciTech Connect

    Sung Bin Park; Jong Hyeon Lee; Sung Chan Hwang; Young Ho Kang; Joon Bo Shim; Han Soo Lee; Eung Ho Kim; Seong Won Park

    2007-07-01

    Electro-depositions of U, Nd, Ce, La and Y on a liquid cadmium cathode in a LiCl-KCl eutectic salt were studied by using an electrolytic cell. For the LiCl-KCl-UCl{sub 3}- NdCl{sub 3}-CeCl{sub 3}-LaCl{sub 3}-YCl{sub 3}/Cd system, cyclic voltammograms and polarization curves were measured and the electrochemical properties of the system were discussed. From the results of the electro-depositions of U and rare earth metals on the LCC, separation factors and recovery ratios of U and REs were obtained and co-electro-depositions of U and REs were investigated. (authors)

  15. Controllable synthesis of Ce{sub 1-x}Zr{sub x}O{sub 2} hollow nanospheres via supercritical anti-solvent precipitation

    SciTech Connect

    Jiang Haoxi; Huang Pan; Liu Lin; Zhang Minhua

    2012-01-15

    Nanocrystalline Ce{sub 1-x}Zr{sub x}O{sub 2} hollow nanospheres were successfully synthesized via supercritical anti-solvent precipitation using supercritical CO{sub 2} as the anti-solvent. It was found that the as-produced samples exhibited hollow spherical structures with uniform diameters ranging from 30 to 50 nm and the sphere walls were composed of various oriented nanocrystallites, with sizes of 3-7 nm. The results of high-resolution transmission electron microscopy showed that the formation of the hollow structures could be controlled by adjusting the solution concentration. The results of temperature-programmed reduction and oxygen storage capacity measurements showed that the hollow nanospheres had enhanced redox properties. A possible mechanism for the formation of Ce{sub 1-x}Zr{sub x}O{sub 2} hollow nanospheres has also been proposed and experimental investigated.

  16. High Activity of Ce1-xNixO2-y for H2 Production through Ethanol Steam Reforming: Tuning Catalytic Performance through Metal-Oxide Interactions

    SciTech Connect

    G Zhou; L Barrio; S Agnoli; S Senanayake; J Evans; A Kubacka; M Estrella; J Hanson; A Martinez-Arias; et al.

    2011-12-31

    The importance of the oxide: Ce{sub 0.8}Ni{sub 0.2}O{sub 2-y} is an excellent catalyst for ethanol steam reforming. Metal-oxide interactions perturb the electronic properties of the small particles of metallic nickel present in the catalyst under the reaction conditions and thus suppress any methanation activity. The nickel embedded in ceria induces the formation of O vacancies, which facilitate cleavage of the OH bonds in ethanol and water.

  17. Preparation and thermoelectric properties of Ga-substituted p-type fully filled skutterudites CeFe{sub 4-x}Ga{sub x}Sb{sub 12}

    SciTech Connect

    Tan, Gangjian; Wang, Shanyu; Tang, Xinfeng; Li, Han; Uher, Ctirad

    2012-12-15

    We demonstrate a successful substitution of Ga at the Fe sites with a solubility limit of -0.11 in the p-type filled skutterudite compounds CeFe{sub 4-x}Ga{sub x}Sb{sub 12}. With increasing Ga content, the electrical conductivity declines while the Seebeck coefficient improves gradually, consistent with the expected decrease in hole concentration due to the extra electrons introduced by Ga. Moreover, the resemblances in electrical transport properties between Ga- and Co-substituted systems with similar composition indicate that Ga doping exerts little influence on the electronic structure near the top of the valence band. The phonon transport is scarcely affected by the introduction of Ga because of negligible differences in atomic masses and sizes of Ga and Fe. The thermoelectric performance of Ga-substituted samples is slightly improved in the temperature range of 600 K to 800 K with respect to that of Ga-free sample, revealing a favorable effect of Ga-substitution on the intermediate temperature power generation application of this promising p-type material. - Graphical abstract: (a-c) Ga successfully substitutes Fe atoms up to x=0.11 in the CeFe{sub 4-x}Ga{sub x}Sb{sub 12}. (d) The introduction of Ga barely affects the electronic structure near E{sub F}. Highlights: Black-Right-Pointing-Pointer Ga as an effective substitute for Fe in p-type skutterudites CeFe{sub 4-x}Ga{sub x}Sb{sub 12}. Black-Right-Pointing-Pointer The solubility limit of Ga at Fe sites is -0.11 in CeFe{sub 4-x}Ga{sub x}Sb{sub 12}. Black-Right-Pointing-Pointer Ga barely affects the electronic structure near the Fermi level.

  18. Commissioning of the 112 MHz SRF Gun and 500 MHz bunching cavities for the CeC PoP Linac

    SciTech Connect

    Belomestnykh, S.; Ben-Zvi, I.; Brutus, J. C.; Litvinenko, V.; McIntosh, P.; Moss, A.; Narayan, G.; Orfin, P.; Pinayev, I.; Rao, T.; Skaritka, J.; Smith, K.; Than, R.; Tuozzolo, J.; Wang, E.; Wheelhouse, A.; Wu, Q.; Xiao, B.; Xin, T.; Xu, W.; Zaltsman, A.

    2015-05-03

    The Coherent electron Cooling Proof-of-Principle (CeC PoP) experiment at BNL includes a short electron linac. During Phase 1, a 112 MHz superconducting RF photo-emission gun and two 500 MHz normal conducting bunching cavities were installed and are under commissioning. The paper describes the Phase1 linac layout and presents commissioning results for the cavities and associated RF, cryogenic and other sub-systems

  19. Multivariate statistical analysis of stream sediments for mineral resources from the Craig NTMS Quadrangle, Colorado

    SciTech Connect

    Beyth, M.; McInteer, C.; Broxton, D.E.; Bolivar, S.L.; Luke, M.E.

    1980-06-01

    Multivariate statistical analyses were carried out on Hydrogeochemical and Stream Sediment Reconnaissance data from the Craig quadrangle, Colorado, to support the National Uranium Resource Evaluation and to evaluate strategic or other important commercial mineral resources. A few areas for favorable uranium mineralization are suggested for parts of the Wyoming Basin, Park Range, and Gore Range. Six potential source rocks for uranium are postulated based on factor score mapping. Vanadium in stream sediments is suggested as a pathfinder for carnotite-type mineralization. A probable northwest trend of lead-zinc-copper mineralization associated with Tertiary intrusions is suggested. A few locations are mapped where copper is associated with cobalt. Concentrations of placer sands containing rare earth elements, probably of commercial value, are indicated for parts of the Sand Wash Basin.

  20. Diffraction Studies from Minerals to Organics - Lessons Learned from Materials Analyses

    SciTech Connect

    Whitfield, Pamela S

    2014-01-01

    In many regards the study of materials and minerals by powder diffraction techniques are complimentary, with techniques honed in one field equally applicable to the other. As a long-time materials researcher many of the examples are of techniques developed for materials analysis applied to minerals. However in a couple of cases the study of new minerals was the initiation into techniques later used in materials-based studies. Hopefully they will show that the study of new minerals structures can provide opportunities to add new methodologies and approaches to future problems. In keeping with the AXAA many of the examples have an Australian connection, the materials ranging from organics to battery materials.

  1. H.R.S. 182-6 - Mineral Exploration | Open Energy Information

    OpenEI (Open Energy Information) [EERE & EIA]

    search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: H.R.S. 182-6 - Mineral ExplorationLegal Published NA Year Signed or Took Effect 2012 Legal...

  2. Revenue ruling 73-538: the service's assault on percentage depletion for ''D'' miners

    SciTech Connect

    Barnes, D.A.

    1983-01-01

    In this article, the author examines the Internal Revenue Service's ruling that storage and loading for shipment at the mine site are nonmining processes for ores and minerals described in section 613(c)(4)(D) of the Internal Revenue Code. He explains the tax consequences of the ruling and discusses the correctness of the position taken by the Internal Revenue Service in light of the relevant case law and the language and legislative history of the statute. The effect of the ruling is to reduce the percentage depletion deduction available to many miners of ores and minerals described in section 613(c)(4)(D), including miners of lead, zinc, copper, gold, silver, uranium, fluorspar, potash, soda ash, garnet and tungsten. (JMT)

  3. Application Of Fluid Inclusion And Rock-Gas Analysis In Mineral...

    OpenEI (Open Energy Information) [EERE & EIA]

    to analyze these gases in fluid inclusions in jasperoid around the Pueblo Viejo gold-silver deposit, in vein minerals from the Creede silver-lead-zinc deposit, and from...

  4. Cal. PRC Section 6910 - Oil and Gas and Mineral Leases | Open...

    OpenEI (Open Energy Information) [EERE & EIA]

    PRC Section 6910 - Oil and Gas and Mineral Leases Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: Cal. PRC Section 6910 - Oil and...

  5. Cal. PRC Section 6909 - Oil and Gas and Mineral Leases: Geothermal...

    OpenEI (Open Energy Information) [EERE & EIA]

    09 - Oil and Gas and Mineral Leases: Geothermal Resources Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- StatuteStatute: Cal. PRC Section 6909 -...

  6. Title 25 CFR 225 Oil and Gas, Geothermal, and Solid Minerals...

    OpenEI (Open Energy Information) [EERE & EIA]

    5 Oil and Gas, Geothermal, and Solid Minerals Agreements Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- Federal RegulationFederal Regulation:...

  7. Magnetic order and heavy fermion behavior in CePd{sub 1+x}Al{sub 6-x}: Synthesis, structure, and physical properties

    SciTech Connect

    Tobash, Paul H., E-mail: ptobash@lanl.go [Materials Physics and Application Division, MPA-10, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716 (United States); Ronning, Filip; Thompson, J.D. [Materials Physics and Application Division, MPA-10, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Bobev, Svilen [Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716 (United States); Bauer, Eric D. [Materials Physics and Application Division, MPA-10, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2010-03-15

    The physical properties including magnetic susceptibility, specific heat, and electrical resistivity of single crystals are reported for the compound CePd{sub 1+x}Al{sub 6-x} (x=0.5) which crystallizes in the tetragonal SrAu{sub 2}Ga{sub 5}-type structure (space group P4/mmm). The compound was grown from an excess of molten Al flux from the respective elements and the crystal structure was established from single-crystal X-ray diffraction. Anomalies in the low temperature specific heat C{sub p}(T) and electrical resistivity rho(T) show that the compound undergoes ferromagnetic order at T{sub C}=2.8 K. In the ordered state, CePd{sub 1.5}Al{sub 5.5} displays heavy fermion behavior with a Sommerfeld coefficient of ca. 500 mJ/mol-K{sup 2}. - Graphical abstract: The compound CePd{sub 1+x}Al{sub 6-x} (x=0.5) has been synthesized and structurally characterized by single-crystal X-ray diffraction. The measured physical properties of temperature and field dependent magnetic susceptibility, specific heat, and electrical resistivity suggests that the compound undergoes ferromagnetic order at ca. 2.8 K and further exhibits relatively heavy fermion behavior with a Sommerfeld coefficient of 500 mJ/mol-K2.

  8. Resolution of the discrepancy between the variation of the physical properties of Ce1-xYbxCoIn5 single crystals and thin films with Yb composition

    DOE PAGES [OSTI]

    Jang, S.; White, B. D.; Lum, I. K.; Kim, H.; Tanatar, M. A.; Straszheim, W. E.; Prozorov, R.; Keiber, T.; Bridges, F.; Shu, L.; et al

    2014-11-18

    The extraordinary electronic phenomena including an Yb valence transition, a change in Fermi surface topology, and suppression of the heavy fermion quantum critical field at a nominal concentration x≈0.2 have been found in the Ce1-xYbxCoIn5 system. These phenomena have no discernable effect on the unconventional superconductivity and normal-state non-Fermi liquid behaviour that occur over a broad range of x up to ~0.8. However, the variation of the coherence temperature T* and the superconducting critical temperature Tc with nominal Yb concentration x for bulk single crystals is much weaker than that of thin films. To determine whether differences in the actualmore » Yb concentration of bulk single crystals and thin film samples might be responsible for these discrepancies, we employed Vegard’s law and the spectroscopically determined values of the valences of Ce and Yb as a function of x to determine the actual composition xact of bulk single crystals. This analysis is supported by energy-dispersive X-ray spectroscopy, wavelength-dispersive X-ray spectroscopy, and transmission X-ray absorption edge spectroscopy measurements. The actual composition xact is found to be about one-third of the nominal concentration x up to x~0.5, and resolves the discrepancy between the variation of the physical properties of Ce1-xYbxCoIn5 single crystals and thin films with Yb concentration.« less

  9. Remarkably robust and correlated coherence and antiferromagnetism in (Ce1-xLax)Cu2Ge2

    SciTech Connect

    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-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)2 at H = 0 was found to be linearly proportional to TN. In conclusion, the jump in the magnetic specific heat ?Cm 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.

  10. Spin-glass freezing above the ordering temperature for the Kondo ferromagnet CeNi{sub 0.4}Cu{sub 0.6}

    SciTech Connect

    Gomez Sal, J.C.; Garcia Soldevilla, J.; Blanco, J.A.; Espeso, J.I.; Rodriguez Fernandez, J.; Luis, F.; Bartolome, F.; Bartolome, J.

    1997-11-01

    The low-temperature magnetic and transport properties of the orthorhombic CeNi{sub 0.4}Cu{sub 0.6} compound have been determined from the analysis of specific heat, ac magnetic susceptibility, electrical resistivity, elastic and inelastic neutron scattering. These measurements present intriguing experimental results that could not be explained within the usual phenomenology of Ce-based compounds. C{sub p} and {chi}{sub ac} present anomalies around 1 K corresponding to ferromagnetic order as confirmed by neutron diffraction. The magnetic structure is collinear with very reduced moments, 0.6{mu}{sub B}/Ce lying in the b direction. Additionally, a clear Kondo behavior is observed with a Kondo temperature T{sub K}=1.9K estimated from quasielastic neutron scattering. Above the ordering temperature, further anomalies are observed in C{sub p} and {chi}{sub ac} that could not be explained as originating from crystal electric field or Kondo effects. From the frequency and field dependence of the {chi}{sub ac}, above T{sub c}, a spin-glass state with a freezing temperature T{sub f}=2K is proposed for this compound. This unusual magnetic behavior is discussed in terms of mixed (positive and negative) Ruderman-Kittel-Kasuya-Yosida interactions, randomness (structural disorder), large hybridization (Kondo effect), and strong magnetocrystalline anisotropy (crystal electric field effects). {copyright} {ital 1997} {ital The American Physical Society}

  11. Electronic structure of the heavy-fermion caged compound Ce3Pd20X6(X=Si,Ge) studied by density functional theory and photoelectron spectroscopy

    DOE PAGES [OSTI]

    Yamaoka, Hitoshi; Schwier, Eike F.; Arita, Masashi; Shimada, Kenya; Tsujii, Naohito; Jarrige, Ignace; Jiang, Jian; Hayashi, Hirokazu; Iwasawa, Hideaki; Namatame, Hirofumi; et al

    2015-03-30

    The electronic structure of Ce₃Pd₂₀X₆ (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 f⁰ (Ce⁴⁺) component with a small fraction of f¹more » (Ce³⁺) component. The spectral weight of f¹ component near the Fermi level Ce₃Pd₂₀Si₆ is stronger than that for Ce₃Pd₂₀Ge₆ 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 Ce₃Pd₂₀Si₆ compared to Ce₃Pd₂₀Ge₆.« less

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

    SciTech Connect

    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.; Inosov, D. S.

    2015-03-13

    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 equivalent 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.

  13. Remarkably robust and correlated coherence and antiferromagnetism in (Ce1-xLax)Cu2Ge2

    SciTech Connect

    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)2 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.

  14. Microbial and Chemical Enhancement of In-Situ Carbon Mineralization in

    Office of Scientific and Technical Information (OSTI)

    Geological Formation (Technical Report) | SciTech Connect Technical Report: Microbial and Chemical Enhancement of In-Situ Carbon Mineralization in Geological Formation Citation Details In-Document Search Title: Microbial and Chemical Enhancement of In-Situ Carbon Mineralization in Geological Formation Predictions of global energy usage suggest a continued increase in carbon emissions and rising concentrations of CO{sub 2} in the atmosphere unless major changes are made to the way energy is

  15. FLUIDIZED BED STEAM REFORMED MINERAL WASTE FORMS: CHARACTERIZATION AND DURABILITY TESTING

    SciTech Connect

    Jantzen, C; Troy Lorier, T; John Pareizs, J; James Marra, J

    2007-03-31

    Fluidized Bed Steam Reforming (FBSR) is being considered as a potential technology for the immobilization of a wide variety of high sodium low activity wastes (LAW) such as those existing at the Hanford site, at the Idaho National Laboratory (INL), and the Savannah River Site (SRS). The addition of clay, charcoal, and a catalyst as co-reactants with the waste denitrates the aqueous wastes and forms a granular mineral waste form that can subsequently be made into a monolith for disposal if necessary. The waste form produced is a multiphase mineral assemblage of Na-Al-Si (NAS) feldspathoid minerals with cage and ring structures and iron bearing spinel minerals. The mineralization occurs at moderate temperatures between 650-750 C in the presence of superheated steam. The cage and ring structured feldspathoid minerals atomically bond radionuclides like Tc-99 and Cs-137 and anions such as SO4, I, F, and Cl. The spinel minerals stabilize Resource Conservation and Recovery Act (RCRA) hazardous species such as Cr and Ni. Granular mineral waste forms were made from (1) a basic Hanford Envelope A low-activity waste (LAW) simulant and (2) an acidic INL simulant commonly referred to as sodium bearing waste (SBW) in pilot scale facilities at the Science Applications International Corporation (SAIC) Science and Technology Applications Research (STAR) facility in Idaho Falls, ID. The FBSR waste forms were characterized and the durability tested via ASTM C1285 (Product Consistency Test), the Environmental Protection Agency (EPA) Toxic Characteristic Leaching Procedure (TCLP), and the Single Pass Flow Through (SPFT) test. The results of the SPFT testing and the activation energies for dissolution are discussed in this study.

  16. FLUIDIZED BED STEAM REFORMED MINERAL WASTE FORMS: CHARACTERIZATION AND DURABILITY TESTING

    SciTech Connect

    Jantzen, C; Troy Lorier, T; John Pareizs, J; James Marra, J

    2006-12-06

    Fluidized Bed Steam Reforming (FBSR) is being considered as a potential technology for the immobilization of a wide variety of high sodium low activity wastes (LAW) such as those existing at the Hanford site, at the Idaho National Laboratory (INL), and the Savannah River Site (SRS). The addition of clay, charcoal, and a catalyst as co-reactants with the waste denitrates the aqueous wastes and forms a granular mineral waste form that can subsequently be made into a monolith for disposal if necessary. The waste form produced is a multiphase mineral assemblage of Na-Al-Si (NAS) feldspathoid minerals with cage and ring structures and iron bearing spinel minerals. The mineralization occurs at moderate temperatures between 650-750 C in the presence of superheated steam. The cage and ring structured feldspathoid minerals atomically bond radionuclides like Tc-99 and Cs-137 and anions such as SO{sub 4}, I, F, and Cl. The spinel minerals stabilize Resource Conservation and Recovery Act (RCRA) hazardous species such as Cr and Ni. Granular mineral waste forms were made from (1) a basic Hanford Envelope A low activity waste (LAW) simulant and (2) an acidic INL simulant commonly referred to as sodium bearing waste (SBW) in pilot scale facilities at the Science Applications International Corporation (SAIC) Science and Technology Applications Research (STAR) facility in Idaho Falls, ID. The FBSR waste forms were characterized and the durability tested via ASTM C1285 (Product Consistency Test), the Environmental Protection Agency (EPA) Toxic Characteristic Leaching Procedure (TCLP), and the Single Pass Flow Through (SPFT) test. The results of the SPFT testing and the activation energies for dissolution are discussed in this study.

  17. Injury experience in nonmetallic mineral mining (except stone and coal), 1984

    SciTech Connect

    Not Available

    1986-01-01

    This report reviews in detail the occupational injury and illness experience of nonmetallic mineral mining (except stone and coal) in the United States for 1984. Data reported by operators of mining establishments concerning work injuries are summarized by work location, accident classification, part of body injured, nature of injury, occupation, and principal type of mineral. 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.

  18. In vivo measurements of lead-210 for assessing cumulative radon exposure in uranium miners

    SciTech Connect

    Guilmette, R.A.; Laurer, G.R.; Lambert, W.E.; Gilliland, F.D.

    1995-12-01

    It has long been recognized that a major contributor to the uncertainty in risk analysis of lung cancer in uranium and other hard rock miners is the estimation of total radon progeny exposure of individual miners under study. These uncertainties arise from the fact that only a limited number of measurements of airborne {sup 222}Rn progeny concentrations were made in the mines during the times that the miners were being exposed, and that dosimeters capable of integrating the Rn progeny exposures of the miners did not exist. Historically, the cumulative exposures for individual uranium and other hard rock miners have been calculated by combining the employee`s work history, which may or may not have included time spent at different jobs within the mines and at different locations within the mines, with whatever periodic measurements of Rn and Rn progeny were available. The amount and quality of the measurement data varied enormously from mine to mine and from population to population. Because the quality of the exposure data collected during the period of active mining in the United STates cannot now be altered substantially, significant improvement in individual miner exposure estimates is only likely to be achieved if a new cumulative exposure metric is developed and implemented. The decay chain of Rn includes the production of {sup 210}Pb, which can accumulate in the skeleton in amounts proportional to the intake of Rn progeny. We hypothesize that the in vivo measurement of {sup 210}Pb in the skulls of miners will provide such a metric. In summary, the primary purpose of this pilot study to demonstrate the feasibility of measuring {sup 210}Pb in the heads of former uranium miners has been accomplished.

  19. Evaluation of Mineral Deposits Along the Little Wind River, Riverton, WY, Processing Site

    SciTech Connect

    Campbell, Sam; Dam, Wiliam

    2014-12-01

    In 2012, the U.S.Department of Energy (DOE) began reassessing the former Riverton, Wyoming, Processing Site area for potential contaminant sources impacting groundwater. A flood in 2010 along the Little Wind River resulted in increases in groundwater contamination (DOE 2013).This investigation is a small part of continued efforts by DOE and other stakeholders to update human health and ecological risk assessments, to make a comprehensive examination of all exposure pathways to ensure that the site remains protective through established institutional controls. During field inspections at the Riverton Site in 2013, a white evaporitic mineral deposit was identified along the bank of the Little Wind River within the discharge zone of the groundwater contamination plume. In December 2013, Savannah River National Laboratory (SRNL) personnel collected a sample for analysis by X-ray fluorescence (Figure 1 shows the type of material sampled). The sample had a uranium concentration of approximately 64 to 73 parts per million. Although the uranium in this mineral deposit is within the expected range for evaporatic minerals in the western United States (SRNL 2014), DOE determined that additional assessment of the mineral deposit was warranted. In response to the initial collection and analysis of a sample of the mineral deposit, DOE developed a work plan (Work Plan to Sample Mineral Deposits Along the Little Wind River, Riverton, Wyoming, Processing Site [DOE 2014]) to further define the extent of these mineral deposits and the concentration of the associated contaminants (Appendix A). The work plan addressed field reconnaissance, mapping, sampling, and the assessment of risk associated with the mineral deposits adjacent to the Little Wind River.

  20. DE-FOA-0001376: Mineral Recovery Phase II: Geothermal Concepts and

    Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)

    Approaches to Validate Extraction Technologies | Department of Energy DE-FOA-0001376: Mineral Recovery Phase II: Geothermal Concepts and Approaches to Validate Extraction Technologies DE-FOA-0001376: Mineral Recovery Phase II: Geothermal Concepts and Approaches to Validate Extraction Technologies December 1, 2015 - 2:58pm Addthis Open Date: 12/01/2015 Close Date: 02/29/2016 Funding Organization: Office of Energy Efficiency and Renewable Energy Funding Number: DE-FOA-0001376 Summary: The