National Library of Energy BETA

Sample records for limestone mo magnesium

  1. AEC Lowman Station FGD conversion from limestone to magnesium-enhanced lime scrubbing

    SciTech Connect (OSTI)

    Inkenhaus, W.; Babu, M.; Smith, K.; Loper, L.

    1996-12-31

    AEC`s Lowman Station is located in Leroy, Alabama. Units 2 and 3, with a total of 516 MW output capacity, were switched from the limestone FGD operation in January of 1996. Prior to switching, personnel from AEC and Dravo Lime Company conducted a four week test on magnesium-enhanced lime and obtained scrubber performance data including SO{sub 2} removal efficiencies on the modulus while burning higher sulfur coal. It was determined that the plant could take advantage of the higher SO{sub 2} removal efficiency of the magnesium-enhanced lime system. Major benefits resulting from this conversion were AEC`s ability to switch to a lower cost high sulfur coal while meeting the stringent SO{sub 2} emission requirements. Power cost savings resulted from the lower liquid to gas ratio required by the magnesium-enhanced lime process. Three recirculation pumps per module were reduced to a single operating pump per module, lowering the scrubber pressure drop. Significant cost reduction in the operating costs of the ball mill was realized due to modifications made to slake lime instead of grinding limestone. This paper discusses the plant modifications that were needed to make the switch, cost justifications, and AEC`s operating experiences to date. AEC and Dravo Lime Company working together as a team conducted detailed cost studies that followed with extended field tests and implementing plant modifications. This plant continues to operate in the magnesium-enhanced lime FGD mode to date.

  2. Recent advances in use of magnesium-enhanced FGD processes include a natural oxidation limestone scrubber conversion and the first commercial ThioClear{reg{underscore}sign} application

    SciTech Connect (OSTI)

    Smith, K.; Babu, M; Inkenhaus, W.

    1998-07-01

    The magnesium-enhanced Thiosorbic FGD process, originally developed by the Dravo Lime Company (DLC) in the early 1970's, is used by over 1,400 MW of power generation in the US primarily by high sulfur coal burning utilities. The excellent SO{sub 2} removal efficiencies, high reliability, and cost effectiveness are the hallmarks of this process. DLC personnel working with Alabama Electric Cooperative's (AEC) personnel converted AEC's Units 2 and 3 at the Lowman Station in Alabama from limestone scrubbing to magnesium-enhanced lime scrubbing process in early 1996. These units totaling 516 MW have been in continuous operation, enabling AEC to save on fuel costs by switching to a lower cost, higher sulfur containing coal, made possible by the higher removal efficiency Thiosorbic process modification. The first part of this paper details the modification that were made and compares the performance differences between the limestone and Thiosorbic FGD processes. ThioClear{reg{underscore}sign} FGD is a forced oxidized magnesium-enhanced lime scrubbing process that produces high quality gypsum and magnesium hydroxide as by-products. The recycle liquor in this process is nearly clear and the capability for SO{sub 2} removal is as high as the Thiosorbic process. DLC working with Applied Energy Systems (AES) of Monaca, Pennsylvania, is currently constructing a 130 Mwe station modification to convert from the natural oxidation Thiosorbic process to the forced oxidation ThioClear{reg{underscore}sign} process. The plant is scheduled to start up by the end of the third quarter of this year. The second part oft his paper details the ThioClear process modifications at AES and describes the by-products and their potential uses.

  3. Recent advances in use of magnesium-enhanced FGD processes include a natural oxidation limestone scrubber conversion and the first commercial ThioClear{reg_sign} application

    SciTech Connect (OSTI)

    Smith, K.; Babu, M.; Inkenhaus, W.

    1998-04-01

    The magnesium-enhanced Thiosorbic FGD process, originally developed by the Dravo Lime Company (DLC) in the early 1970`s, is used by over 1400 MW of power generation in the US primarily by high sulfur coal burning utilities. The excellent SO{sub 2} removal efficiencies, high reliability, and cost effectiveness are the hallmarks of this process. DLC personnel working with Alabama Electric Cooperative`s (AEC) personnel converted AEC`s Units 2 and 3 at the Lowman Station in Alabama from limestone scrubbing to magnesium-enhanced lime scrubbing process in early 1996. These units totaling 516 MW have been in continuous operation, enabling AEC to save on fuel costs by switching to a lower cost, higher sulfur containing coal, made possible by the higher removal efficiency Thiosorbic process modification. The first part of this paper details the modifications that were made and compares the performance differences between the limestone and Thiosorbic FGD processes. ThioClear{reg_sign} FGD is a forced oxidized magnesium-enhanced lime scrubbing process that produces high quality gypsum and magnesium hydroxide as by-products. The recycle liquor in this process is nearly clear and the capability for SO{sub 2} removal is as high as the Thiosorbic process. DLC working with Applied Energy Systems (AES) of Monaca, Pennsylvania, is currently constructing a 130 Mwe station modification to convert from the natural oxidation Thiosorbic process to the forced oxidation ThioClear{reg_sign} process. The plant is scheduled to start up by the end of the third quarter of this year. The second part of this paper details the ThioClear process modifications at AES and describes the by-ducts and their potential uses.

  4. Indiana's Trenton limestone geology

    SciTech Connect (OSTI)

    Keith, B.D.

    1981-03-01

    The term Trenton limestone is the stratigraphic designation for a unit in northern Indiana composed of both limestone and dolomite. The Trenton is Middle Ordovician (Champlainian) in age and related clearly to the position of the Cincinnati arch. The limestone is thickest in northern Indiana and thins toward the southeast. Isopach maps of the Trenton limestone and the Maquoketa group above it indicate that the Cincinnati arch did not exist as a positive structural influence to sedimentation until after Ordovician time. Preliminary results of an ongoing study of the Trenton reservoir suggest that second and tertiary recovery there will be limited. Because of the low density of drilling on the Trenton's north flank, however, large areas remain virtually untested; more structural or stratigraphic traps similar to those of the Urbana field could exist. A better definition of the distribution of the dolomite facies will lead to a more accurate assessment of the Trenton's potential.

  5. Production of magnesium metal

    DOE Patents [OSTI]

    Blencoe, James G. [Harriman, TN; Anovitz, Lawrence M. [Knoxville, TN; Palmer, Donald A. [Oliver Springs, TN; Beard, James S. [Martinsville, VA

    2010-02-23

    A process of producing magnesium metal includes providing magnesium carbonate, and reacting the magnesium carbonate to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The carbon dioxide is used as a reactant in a second process. In another embodiment of the process, a magnesium silicate is reacted with a caustic material to produce magnesium hydroxide. The magnesium hydroxide is reacted with a source of carbon dioxide to produce magnesium carbonate. The magnesium carbonate is reacted to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The invention further relates to a process for production of magnesium metal or a magnesium compound where an external source of carbon dioxide is not used in any of the reactions of the process. The invention also relates to the magnesium metal produced by the processes described herein.

  6. Production of magnesium metal

    DOE Patents [OSTI]

    Blencoe, James G.; Anovitz, Lawrence M.; Palmer, Donald A.; Beard, James S.

    2012-04-10

    A process of producing magnesium metal includes providing magnesium carbonate, and reacting the magnesium carbonate to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The carbon dioxide is used as a reactant in a second process. In another embodiment of the process, a magnesium silicate is reacted with a caustic material to produce magnesium hydroxide. The magnesium hydroxide is reacted with a source of carbon dioxide to produce magnesium carbonate. The magnesium carbonate is reacted to produce a magnesium-containing compound and carbon dioxide. The magnesium-containing compound is reacted to produce magnesium metal. The invention also relates to the magnesium metal produced by the processes described herein.

  7. The relative merits of dolomitic and calcitic limestone in detoxifying and revegetating acidic, nickel- and copper-contaminated soils in the Sudbury mining and smelting region of Canada

    SciTech Connect (OSTI)

    McHale, D.; Winterhalder, K.

    1996-12-31

    Soils in the Sudbury mining and smelting region have been rendered phytotoxic and barren by acidification and Particulate metal contamination, but can be detoxified revegetated by the surface application of an growth is better on soil treated ground limestone. On certain barren sites, plant growth is better on soil treated with dolomitic limestone than with calcitic limestone and greenhouse experiments using mung beans (Vigna radiata) have shown superior root and shoot growth on certain contaminated soils when the limestone is dolomitic rather than calcitic. Results of experiments with species used in revegetation (Agrostis gigantea and Lotus corniculatus) suggest that leguminous species are more sensitive to Ca:Mg ratio than grasses, that the plant response to this ratio is greater at lowering liming levels, and that the response is more marked on more toxic soils. The effects of calcium:magnesium ratio of the limestone used in revegetating acidic, metal-contaminated soils are clearly complex, interactive and difficult to interpret. Further studies are needed, but meanwhile it is recommended that the practice of using dolomitic limestone to detoxify barren Sudbury soils be continued, since there is a risk of induced magnesium deficiency at certain sites when calcitic limestone is used.

  8. Mo-99

    National Nuclear Security Administration (NNSA)

    its project for domestic production of molybdenum-99 (Mo-99) without highly enriched uranium (HEU).

    Mo-99 is the parent isotope of technetium-99m, which is the most widely...

  9. Method for production of magnesium

    DOE Patents [OSTI]

    Diaz, Alexander F. (Cambridge, MA); Howard, Jack B. (Winchester, MA); Modestino, Anthony J. (Hanson, MA); Peters, William A. (Lexington, MA)

    1998-01-01

    A continuous process for the production of elemental magnesium is described. Magnesium is made from magnesium oxide and a light hydrocarbon gas. In the process, a feed stream of the magnesium oxide and gas is continuously fed into a reaction zone. There the magnesium oxide and gas are reacted at a temperature of about 1400.degree. C. or greater in the reaction zone to provide a continuous product stream of reaction products, which include elemental magnesium. The product stream is continuously quenched after leaving the reaction zone, and the elemental magnesium is separated from other reaction products.

  10. Method for production of magnesium

    DOE Patents [OSTI]

    Diaz, A.F.; Howard, J.B.; Modestino, A.J.; Peters, W.A.

    1998-07-21

    A continuous process for the production of elemental magnesium is described. Magnesium is made from magnesium oxide and a light hydrocarbon gas. In the process, a feed stream of the magnesium oxide and gas is continuously fed into a reaction zone. There the magnesium oxide and gas are reacted at a temperature of about 1400 C or greater in the reaction zone to provide a continuous product stream of reaction products, which include elemental magnesium. The product stream is continuously quenched after leaving the reaction zone, and the elemental magnesium is separated from other reaction products. 12 figs.

  11. Electrodeposition of magnesium and magnesium/aluminum alloys

    DOE Patents [OSTI]

    Mayer, Anton

    1988-01-01

    Electrolytes and plating solutions for use in processes for electroplating and electroforming pure magnesium and alloys of aluminum and magnesium and also electrodeposition processes. An electrolyte of this invention is comprised of an alkali metal fluoride or a quaternary ammonium halide, dimethyl magnesium and/or diethyl magnesium, and triethyl aluminum and/or triisobutyl aluminum. An electrolyte may be dissolved in an aromatic hydrocarbon solvent to form a plating solution. The proportions of the component compounds in the electrolyte are varied to produce essentially pure magnesium or magnesium/aluminum alloys having varying selected compositions.

  12. Electrodeposition of magnesium and magnesium/aluminum alloys

    DOE Patents [OSTI]

    Mayer, A.

    1988-01-21

    Electrolytes and plating solutions for use in processes for electroplating and electroforming pure magnesium and alloys of aluminum and magnesium and also electrodeposition processes. An electrolyte of this invention is comprised of an alkali metal fluoride or a quaternary ammonium halide, dimethyl magnesium and/or diethyl magnesium, and triethyl aluminum and/or triisobutyl aluminum. An electrolyte may be dissolved in an aromatic hydrocarbon solvent to form a plating solution. The proportions of the component compounds in the electrolyte are varied to produce essentially pure magnesium or magnesium/aluminum alloys having varying selected compositions.

  13. Mo-99

    National Nuclear Security Administration (NNSA)

    NorthStar Medical Radioisotopes to further develop its technology to produce Mo-99 via neutron capture, bringing the total NNSA support to this project to the maximum of 25...

  14. AEC Lowman Station - coal switching and magnesium-enhanced lime scrubbing to lower operating costs

    SciTech Connect (OSTI)

    Inkenhaus, W.; Babu, M.; Smith, K.; Loper, L.

    1997-12-31

    AEC`s Lowman Station is located in Leroy, Alabama. There are three coal-fired boilers at this station. Unit 1 is capable of generating 85 MW without a flue gas desulfurization, FGD, system. Units 2 and 3, with a total of 516 MW output capacity, are equipped with FGD systems. The FGD plant was designed for wet limestone FGD with natural oxidation. Lowman Station burned low sulfur, 1.3 to 1.8% sulfur, coal. In January of 1996 AEC switched Units 2 and 3 from limestone to magnesium-enhanced lime FGD operation. It was determined that the plant could take advantage of the higher SO{sub 2} removal efficiency of the magnesium-enhanced lime system. Major benefits resulting from this conversion were AEC`s ability to switch to a lower cost high sulfur coal while meeting the stringent SO{sub 2} emission requirements. Power cost savings resulted from the lower liquid to gas ratio required by the magnesium-enhanced lime process. Three recirculation pumps per module were reduced to a single operating pump per module, lowering the scrubber pressure drop. Significant cost reduction in the operating costs of the ball mill was realized due to modifications made to slake lime instead of grinding limestone. Prior to switching, personnel from AEC and Dravo Lime Company ran a four week test on magnesium-enhanced lime to obtain scrubber performance data including SO{sub 2} removal efficiencies on the modules while burning a 1.8% sulfur coal. This paper discusses the plant modifications that were needed to make the switch, cost justifications due to coal switching, and AEC`s operating experiences to date. AEC and Dravo Lime Company working together as a team conducted detailed cost studies, followed by extensive field tests and implemented the plant modifications. This plant continues to operate burning higher sulfur coal with the magnesium-enhanced lime FGD system.

  15. Limestone County, Texas: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Datasets Community Login | Sign Up Search Page Edit with form History Limestone County, Texas: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates...

  16. [Analysis of trace elements in limestone for archeological functions

    SciTech Connect (OSTI)

    Blanc, A.; Holmes, L.; Harbottle, G.

    1998-12-31

    Numerous quarries in the Lutetian limestone formations of the Paris Basin provided stone for the building and the decoration of monuments from antiquity to the present. To determine the origin of stone used for masonry and sculptures in these monuments, a team of geologists and archaeologists has investigated 300 quarries and collected 2,300 samples. Petrographic and paleontologic examination of thin sections allows geologists to distinguish Lutetian limestones from Jurassic and Cretaceous limestones. Geologists also seek to formulate hypotheses regarding the origin of Lutetian limestones used for building and sculpture in the Paris region. In the search for the sources of building and sculptural stone, the analytical methods of geologists are limited because often several quarries produce the same lithofacies. A new tool is now available, however, to attack questions of provenance raised by art historians. Because limestones from different sources have distinctive patterns of trace-element concentrations, compositional analysis by neutron activation allows one to compare building or sculptural stone from one monument with stone from quarries or other monuments. This analytical method subjects a powdered limestone sample to standard neutron activation analysis procedures at Brookhaven National Laboratory. With the help of computer programs, the compositional fingerprints of Lutetian limestones can be determined and stored in a database. The limestone database contains data for approximately 2,100 samples from monuments, sculptures and quarries. It is particularly rich in samples from the Paris Basin.

  17. Magnesium fluoride recovery method

    DOE Patents [OSTI]

    Gay, Richard L.; McKenzie, Donald E.

    1989-01-01

    A method of obtaining magnesium fluoride substantially free from radioactive uranium from a slag containing the same and having a radioactivity level of at least about 7000 pCi/gm. The slag is ground to a particle size of about 200 microns or less. The ground slag is contacted with an acid under certain prescribed conditions to produce a liquid product and a particulate solid product. The particulate solid product is separated from the liquid and treated at least two more times with acid to produce a solid residue consisting essentially of magnesium fluoride substantially free of uranium and having a residual radioactivity level of less than about 1000 pCi/gm. In accordance with a particularly preferred embodiment of the invention a catalyst and an oxidizing agent are used during the acid treatment and preferably the acid is sulfuric acid having a strength of about 1.0 Normal.

  18. Synthesis of magnesium diboride by magnesium vapor infiltration process (MVIP)

    DOE Patents [OSTI]

    Serquis, Adriana C.; Zhu, Yuntian T.; Mueller, Frederick M.; Peterson, Dean E.; Liao, Xiao Zhou

    2003-01-01

    A process of preparing superconducting magnesium diboride powder by heating an admixture of solid magnesium and amorphous boron powder or pellet under an inert atmosphere in a Mg:B ratio of greater than about 0.6:1 at temperatures and for time sufficient to form said superconducting magnesium diboride. The process can further include exposure to residual oxygen at high synthesis temperatures followed by slow cooling. In the cooling process oxygen atoms dissolved into MgB.sub.2 segregated to form nanometer-sized coherent Mg(B,O) precipitates in the MgB.sub.2 matrix, which can act as flux pinning centers.

  19. Promising Magnesium Battery Research at ALS

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

    Promising Magnesium Battery Research at ALS Promising Magnesium Battery Research at ALS Print Wednesday, 23 January 2013 16:59 toyota battery a) Cross-section of the in situ ...

  20. Synthesis of superconducting magnesium diboride objects

    DOE Patents [OSTI]

    Finnemore, Douglas K.; Canfield, Paul C.; Bud'ko, Sergey L.; Ostenson, Jerome E.; Petrovic, Cedomir; Cunningham, Charles E.; Lapertot, Gerard

    2003-08-15

    A process to produce magnesium diboride objects from boron objects with a similar form is presented. Boron objects are reacted with magnesium vapor at a predetermined time and temperature to form magnesium diboride objects having a morphology similar to the boron object's original morphology.

  1. Synthesis Of Superconducting Magnesium Diboride Objects.

    DOE Patents [OSTI]

    Finnemore, Douglas K.; Canfield, Paul C.; Bud'ko, Sergey L.; Ostenson, Jerome E.; Petrovic, Cedomir; Cunningham, Charles E.; Lapertot, Gerard

    2003-07-08

    A process to produce magnesium diboride objects from boron objects with a similar form is presented. Boron objects are reacted with magnesium vapor at a predetermined time and temperature to form magnesium diboride objects having a morphology similar to the boron object's original morphology.

  2. Modified dry limestone process for control of sulfur dioxide emissions

    DOE Patents [OSTI]

    Shale, Correll C.; Cross, William G.

    1976-08-24

    A method and apparatus for removing sulfur oxides from flue gas comprise cooling and conditioning the hot flue gas to increase the degree of water vapor saturation prior to passage through a bed of substantially dry carbonate chips or lumps, e.g., crushed limestone. The reaction products form as a thick layer of sulfites and sulfates on the surface of the chips which is easily removed by agitation to restore the reactive surface of the chips.

  3. Method for magnesium sulfate recovery

    DOE Patents [OSTI]

    Gay, R.L.; Grantham, L.F.

    1987-08-25

    A method is described for obtaining magnesium sulfate substantially free from radioactive uranium from a slag containing the same and having a radioactivity level of at least about 7,000 pCi/gm. The slag is ground to a particle size of about 200 microns or less. The ground slag is then contacted with a concentrated sulfuric acid under certain prescribed conditions to produce a liquid product and a solid product. The particulate solid product and a minor amount of the liquid is then treated to produce a solid residue consisting essentially of magnesium sulfate substantially free of uranium and having a residual radioactivity level of less than 1,000 pCi/gm. In accordance with the preferred embodiment of the invention, a catalyst and an oxidizing agent are used during the initial acid treatment and a final solid residue has a radioactivity level of less than about 50 pCi/gm.

  4. Method for magnesium sulfate recovery

    DOE Patents [OSTI]

    Gay, Richard L.; Grantham, LeRoy F.

    1987-01-01

    A method of obtaining magnesium sulfate substantially free from radioactive uranium from a slag containing the same and having a radioactivity level of at least about 7000 pCi/gm. The slag is ground to a particle size of about 200 microns or less. The ground slag is then contacted with a concentrated sulfuric acid under certain prescribed conditions to produce a liquid product and a solid product. The particulate solid product and a minor amount of the liquid is then treated to produce a solid residue consisting essentially of magnesium sulfate substantially free of uranium and having a residual radioactivity level of less than 1000 pCi/gm. In accordance with the preferred embodiment of the invention, a catalyst and an oxidizing agent are used during the initial acid treatment and a final solid residue has a radioactivity level of less than about 50 pCi/gm.

  5. Method for removing magnesium from aluminum-magnesium alloys with engineered scavenger compound

    SciTech Connect (OSTI)

    Riley, W.D.; Jong, B.W.

    1994-12-31

    The invention relates to a method for removal and production of high purity magnesium from aluminum-magnesium alloys using an engineered scanvenger compound. In particular, the invention relates to a method for removal and production of high purity magnesium from aluminum-magnesium alloys using the engineered scanvenger compound (ESC) lithium titanate (Li2O3TiO2). The removal of magnesium from the aluminum-magnesium alloys is performed at about 600-750 C in a molten salt bath of KCl or KCl-MgCl2 using lithium titanate (Li2O3TiO2) as the engineered scavenger compound (ESC). Electrode deposition of magnesium from the loaded ESC onto a stainless steel electrode is accomplished in a second step, and provides a clean magnesium electrode deposit for recycling. The second step also prepares the ESC for reuse.

  6. Substrate and method for the formation of continuous magnesium diboride and doped magnesium diboride wire

    DOE Patents [OSTI]

    Suplinskas, Raymond J.; Finnemore, Douglas; Bud'ko, Serquei; Canfield, Paul

    2007-11-13

    A chemically doped boron coating is applied by chemical vapor deposition to a silicon carbide fiber and the coated fiber then is exposed to magnesium vapor to convert the doped boron to doped magnesium diboride and a resultant superconductor.

  7. IMPROVED MAGNESIUM OXIDE SLIP CASTING METHOD

    DOE Patents [OSTI]

    Stoddard, S.D.; Nuckolls, D.E.

    1963-12-31

    A process for making an aqueous magnesium oxide slip casting slurry comprising the steps of mixing finely ground fused magnesium oxide with water, milling the slurry for at least 30 hours at a temperature of 2-10 deg C (the low temperature during milling inhibiting the formation of hydrated magnesium oxide), discharging the slurry from the mill, adding hydrochloric acid as a deflocculent, and adding a scum inhibitor is presented. (AEC)

  8. Coordination Chemistry in Magnesium Battery Electrolytes: How...

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

    March 3, 2014, Research Highlights Coordination Chemistry in Magnesium Battery Electrolytes: How Ligands Affect Their Performance (Top) Schematic illustration of the solution ...

  9. Stable magnesium peroxide at high pressure (Journal Article)...

    Office of Scientific and Technical Information (OSTI)

    Stable magnesium peroxide at high pressure Citation Details In-Document Search Title: Stable magnesium peroxide at high pressure Authors: Lobanov, Sergey S. ; Zhu, Qiang ; ...

  10. New Electrode Materials for Magnesium Batteries and Metal Anodes...

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

    Return to Search New Electrode Materials for Magnesium Batteries and Metal Anodes Beyond ... Technology Marketing Summary Magnesium ion batteries present a viable alternative to ...

  11. MoS2

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

    ... mechanisms for its eventual aging and demise. Figure 3: Typical x-ray diffraction of the poorly crystalline MoS phase. (reference 5) Often transmission electron microscopy (TEM) ...

  12. SLAM: a sodium-limestone concrete ablation model

    SciTech Connect (OSTI)

    Suo-Anttila, A.J.

    1983-12-01

    SLAM is a three-region model, containing a pool (sodium and reaction debris) region, a dry (boundary layer and dehydrated concrete) region, and a wet (hydrated concrete) region. The model includes a solution to the mass, momentum, and energy equations in each region. A chemical kinetics model is included to provide heat sources due to chemical reactions between the sodium and the concrete. Both isolated model as well as integrated whole code evaluations have been made with good results. The chemical kinetics and water migration models were evaluated separately, with good results. Several small and large-scale sodium limestone concrete experiments were simulated with reasonable agreement between SLAM and the experimental results. The SLAM code was applied to investigate the effects of mixing, pool temperature, pool depth and fluidization. All these phenomena were found to be of significance in the predicted response of the sodium concrete interaction. Pool fluidization is predicted to be the most important variable in large scale interactions.

  13. Tape casting of magnesium oxide.

    SciTech Connect (OSTI)

    Ayala, Alicia; Corral, Erica L.; Loehman, Ronald E.; Bencoe, Denise Nora; Reiterer, Markus; Shah, Raja A.

    2008-02-01

    A tape casting procedure for fabricating ceramic magnesium oxide tapes has been developed as a method to produce flat sheets of sintered MgO that are thin and porous. Thickness of single layer tapes is in the range of 200-400 {micro}m with corresponding surface roughness values in the range of 10-20 {micro}m as measured by laser profilometry. Development of the tape casting technique required optimization of pretreatment for the starting magnesium oxide (MgO) powder as well as a detailed study of the casting slurry preparation and subsequent heat treatments for sintering and final tape flattening. Milling time of the ceramic powder, plasticizer, and binder mixture was identified as a primary factor affecting surface morphology of the tapes. In general, longer milling times resulted in green tapes with a noticeably smoother surface. This work demonstrates that meticulous control of the entire tape casting operation is necessary to obtain high-quality MgO tapes.

  14. Hydration mechanisms of ternary Portland cements containing limestone powder and fly ash

    SciTech Connect (OSTI)

    De Weerdt, K.; Haha, M. Ben; Le Saout, G.; Kjellsen, K.O.; Justnes, H.; Lothenbach, B.

    2011-03-15

    The effect of minor additions of limestone powder on the properties of fly ash blended cements was investigated in this study using isothermal calorimetry, thermogravimetry (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) techniques, and pore solution analysis. The presence of limestone powder led to the formation of hemi- and monocarbonate and to a stabilisation of ettringite compared to the limestone-free cements, where a part of the ettringite converted to monosulphate. Thus, the presence of 5% of limestone led to an increase of the volume of the hydrates, as visible in the increase in chemical shrinkage, and an increase in compressive strength. This effect was amplified for the fly ash/limestone blended cements due to the additional alumina provided by the fly ash reaction.

  15. Magnesium doping of boron nitride nanotubes

    SciTech Connect (OSTI)

    Legg, Robert; Jordan, Kevin

    2015-06-16

    A method to fabricate boron nitride nanotubes incorporating magnesium diboride in their structure. In a first embodiment, magnesium wire is introduced into a reaction feed bundle during a BNNT fabrication process. In a second embodiment, magnesium in powder form is mixed into a nitrogen gas flow during the BNNT fabrication process. MgB.sub.2 yarn may be used for superconducting applications and, in that capacity, has considerably less susceptibility to stress and has considerably better thermal conductivity than these conventional materials when compared to both conventional low and high temperature superconducting materials.

  16. Preliminary microfacies analysis and cyclicity of the Wahoo Limestone, Lisburne Field, North Slope, Alaska

    SciTech Connect (OSTI)

    Morgan, S.K.; Watts, K.F.

    1995-05-01

    A well from the Lisburne field near Prudhoe Bay was examined in core, thin section, and on well logs for comparison with Wahoo Limestone in the Arctic National Wildlife Refuge (ANWR). Carbonate cycles (parasequences) are well developed in both areas but the greater abundance of terrigenous sediment and associated carbonate facies indicate that the study well is located in a more landward position on the Wahoo carbonate ramp, closer to a source of terrigenous sediment. This report presents the preliminary results of microfacies analyses that have been conducted on 424 of a total 1,115 thin sections from the study well. The stratigraphic nomenclature extended from ANWR (the type locality of the Wahoo Limestone) is different that the terminology previously used for the subsurface Lisburne Group near Prudhoe Bay. We distinguish informal lower and upper members within the Mississippian to Pennsylvanian Wahoo Limestone which overlies the Mississippian Alapah Limestone. Our upper Alapah corresponds to the middle Alapah of previous workers. Our lower Wahoo Limestone member corresponds to the upper Alapah of previous workers. Our upper Wahoo Limestone member corresponds to the previous Wahoo Limestone and is the major hydrocarbon reservoir at the Lisburne field, which is characterized by well-developed carbonate cycles (parasequences).

  17. LOST FOAM CASTING OF MAGNESIUM ALLOYS

    SciTech Connect (OSTI)

    Han, Qingyou [ORNL; Dinwiddie, Ralph Barton [ORNL; Sklad, Philip S [ORNL; Currie, Kenneth [Tennessee Technological University; Abdelrahman, Mohamed [Tennessee Technological University; Vondra, Fred [Tennessee Technological University; Walford, Graham [Walford Technologies; Nolan, Dennis J [Foseco-Morval

    2007-01-01

    The lost foam casting process has been successfully used for making aluminum and cast iron thin walled castings of complex geometries. Little work has been carried out on cast magnesium alloys using the lost foam process. The article describes the research activities at Oak Ridge National Laboratory and Tennessee Technological University on lost foam casting of magnesium alloys. The work was focused on castings of simple geometries such as plate castings and window castings. The plate castings were designed to investigate the mold filling characteristics of magnesium and aluminum alloys using an infrared camera. The pate castings were then characterized for porosity distribution. The window castings were made to test the castability of the alloys under lost foam conditions. Significant differences between lost foam aluminum casting and lost foam magnesium casting have been observed.

  18. Nuclear reactor shield including magnesium oxide

    DOE Patents [OSTI]

    Rouse, Carl A.; Simnad, Massoud T.

    1981-01-01

    An improvement in nuclear reactor shielding of a type used in reactor applications involving significant amounts of fast neutron flux, the reactor shielding including means providing structural support, neutron moderator material, neutron absorber material and other components as described below, wherein at least a portion of the neutron moderator material is magnesium in the form of magnesium oxide either alone or in combination with other moderator materials such as graphite and iron.

  19. Magnesium phosphate glass cements with ceramic-type properties

    DOE Patents [OSTI]

    Sugama, Toshifumi; Kukacka, Lawrence E.

    1984-03-13

    Rapid setting magnesium phosphate (Mg glass) cementitious materials consisting of magnesium phosphate cement paste, polyborax and water-saturated aggregate exhibiting rapid setting and high early strength characteristics. The magnesium glass cement is prepared from a cation-leachable powder and a bivalent metallic ion-accepting liquid such as an aqueous solution of diammonium phosphate and ammonium polyphosphate. The cation-leachable powder includes a mixture of two different magnesium oxide powders processed and sized differently which when mixed with the bivalent metallic ion-accepting liquid provides the magnesium glass cement consisting primarily of magnesium ortho phosphate tetrahydrate, with magnesium hydroxide and magnesium ammonium phosphate hexahydrate also present. The polyborax serves as a set-retarder. The resulting magnesium mono- and polyphosphate cements are particularly suitable for use as a cementing matrix in rapid repair systems for deteriorated concrete structures as well as construction materials and surface coatings for fireproof structures.

  20. Magnesium-phosphate-glass cements with ceramic-type properties

    DOE Patents [OSTI]

    Sugama, T.; Kukacka, L.E.

    1982-09-23

    Rapid setting magnesium phosphate (Mg glass) cementitious materials consisting of magnesium phosphate cement paste, polyborax and water-saturated aggregate, exhibits rapid setting and high early strength characteristics. The magnesium glass cement is prepared from a cation-leachable powder and a bivalent metallic ion-accepting liquid such as an aqueous solution of diammonium phosphate and ammonium polyphosphate. The cation-leachable powder includes a mixture of two different magnesium oxide powders processed and sized differently which when mixed with the bivalent metallic ion-accepting liquid provides the magnesium glass cement consisting primarily of magnesium ortho phosphate tetrahydrate, with magnesium hydroxide and magnesium ammonium phosphate hexahydrate also present. The polyborax serves as a set-retarder. The resulting magnesium mono- and polyphosphate cements are particularly suitable for use as a cementing matrix in rapid repair systems for deteriorated concrete structures as well as construction materials and surface coatings for fireproof structures.

  1. US WNC MO Site Consumption

    Gasoline and Diesel Fuel Update (EIA)

    WNC MO Site Consumption million Btu 0 500 1,000 1,500 2,000 2,500 US WNC MO ... 9,000 12,000 15,000 US WNC MO Site Consumption kilowatthours 0 300 600 900 1,200 ...

  2. Friction Stir and Ultrasonic Solid State Joining of Magnesium...

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

    FSW & USW Solid State Joining of Magnesium to Steel Formability of Direct Cast Mg Sheet and Friction Stir and Ultrasonic Joining of Magnesium to Steel FY 2009 Progress Report for ...

  3. SOLID STATE JOINING OF MAGNESIUM TO STEEL

    SciTech Connect (OSTI)

    Jana, Saumyadeep; Hovanski, Yuri; Pilli, Siva Prasad; Field, David P.; Yu, Hao; Pan, Tsung-Yu; Santella, M. L.

    2012-06-04

    Friction stir welding and ultrasonic welding techniques were applied to join automotive magnesium alloys to steel sheet. The effect of tooling and process parameters on the post-weld microstructure, texture and mechanical properties was investigated. Static and dynamic loading were utilized to investigate the joint strength of both cast and wrought magnesium alloys including their susceptibility and degradation under corrosive media. The conditions required to produce joint strengths in excess of 75% of the base metal strength were determined, and the effects of surface coatings, tooling and weld parameters on weld properties are presented.

  4. Promising Magnesium Battery Research at ALS

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

    Promising Magnesium Battery Research at ALS Promising Magnesium Battery Research at ALS Print Wednesday, 23 January 2013 16:59 toyota battery a) Cross-section of the in situ electrochemical/XAS cell with annotations. b) Drawing and c) photograph of the assembled cell. Alternatives to the current lithium-ion-based car batteries are at the forefront of the automotive industry's research agenda-manufacturers want to build cars with longer battery life, and to do that they're going to have to find

  5. The occurrence of freshwater limestones in the Upper Pennsylvanian and lower Permian of the northern Appalachian basin

    SciTech Connect (OSTI)

    Eggleston, J.R. ); Ferdinand, L.F. )

    1990-05-01

    Freshwater limestones comprise a significant portion of the Upper Pennsylvanian and Lower Permian strata of the northern Appalachian basin. In some areas, the Monogahela Group consists of as much as 50% freshwater limestones. These limestones are clayey to silty, iron-bearing, sparsely fossiliferous, micritic, and thinly bedded or nodular and are presumed to be lacustrine in origin. They are part of a recurring sequence of beds that include coal, sandstone, shale/clay, and marine limestone. The initial goals of this study are to develop a stratigraphic framework for these freshwater limestones and to determine, their lateral continuity, thickness variability, and relation to other beds in this section, in particular the coals, on a regional scale. The Pittsburgh coal and Ames limestone are very persistent regionally and are used as a datum. Regional correlations show that possibly 20 freshwater limestone beds are persistent and widespread; some cover at least 5,000 mi{sup 2} in eastern Ohio, western Pennsylvania, northern West Virginia and western Maryland. Cross sections and fence diagrams constructed from drill logs and measured sections indicate that the thickness of these limestone beds varies laterally and between beds, ranging from less than 1 to 150 ft thick. Correlations also show stratigraphic and paleogeographic relationships between the coals and freshwater limestones. Many of the limestones underlie coal beds, directly in some places. The coals and limestones are better developed in the northern part of the Appalachian basin. These associations may hold significant clues to the depositional and the paleoclimatic setting of the freshwater limestones and the coals.

  6. Stratigraphy and diagenesis of the Mississippian Lodgepole Limestone, Williston Basin, North Dakota

    SciTech Connect (OSTI)

    Grover, P.W. )

    1996-01-01

    Stratigraphic correlation of the Lodgepole Limestone (Bottineau Interval) indicates a sequence of three clinoform-shaped wedges that filled in the early Williston Basin. To date four productive 100m thick mounds have been discovered in the Lodgepole Limestone at Dickinson Field. The mounds seem to have nucleated at the toe of slope of the first highstand system tract and were subsequently buried by the second highstand systems tract. By isopaching each of the systems tracts one can predict were other mounds might have nucleated. Burial depth of the Bakken Shale-Lodgepole Limestone contact grade from 0.6 km at the edge of the Williston Basin to 3.4 km in the center. With increased depth the basal Lodgepole Limestone shows three phases of dolomitization, which are: small clear early dolomite; later iron rich fracture filling saddle dolomite and a later iron rich dolomite that seems to follow stylolites. Pre-oil migration mineralization of the overlying limestone include minor amounts of: anhydrite, pyrite, iron poor sphalerite, late iron rich sphalerite, chalcopyrite and celestite.

  7. Stratigraphy and diagenesis of the Mississippian Lodgepole Limestone, Williston Basin, North Dakota

    SciTech Connect (OSTI)

    Grover, P.W.

    1996-12-31

    Stratigraphic correlation of the Lodgepole Limestone (Bottineau Interval) indicates a sequence of three clinoform-shaped wedges that filled in the early Williston Basin. To date four productive 100m thick mounds have been discovered in the Lodgepole Limestone at Dickinson Field. The mounds seem to have nucleated at the toe of slope of the first highstand system tract and were subsequently buried by the second highstand systems tract. By isopaching each of the systems tracts one can predict were other mounds might have nucleated. Burial depth of the Bakken Shale-Lodgepole Limestone contact grade from 0.6 km at the edge of the Williston Basin to 3.4 km in the center. With increased depth the basal Lodgepole Limestone shows three phases of dolomitization, which are: small clear early dolomite; later iron rich fracture filling saddle dolomite and a later iron rich dolomite that seems to follow stylolites. Pre-oil migration mineralization of the overlying limestone include minor amounts of: anhydrite, pyrite, iron poor sphalerite, late iron rich sphalerite, chalcopyrite and celestite.

  8. Porosity development in the Copper Ridge Dolomite and Maynardville Limestone, Bear Creek Valley and Chestnut Ridge, Tennessee

    SciTech Connect (OSTI)

    Goldstrand, P.M.; Menefee, L.S.; Dreier, R.B.

    1995-12-01

    Matrix porosity data from deep core obtained in Bear Creek Valley indicate that porosities in the Maynardville Limestone are lithology and depth dependent. Matrix porosities are greater in the Cooper Ridge Dolomite than in the Maynardville Limestone, yet there is no apparent correlation with depth. Two interrelated diagenetic processes are the major controlling factors on porosity development in the Copper Ridge Dolomite and Maynardville Limestone; dissolution of evaporate minerals and dedolomitization. Both of these diagenetic processes produce matrix porosities between 2.1 and 1.3% in the Copper Ridge Dolomite and upper part of the Maynardville Limestone (Zone 6) to depths of approximately 600 ft bgs. Mean matrix porosities in Zones 5 through 2 of the Maynardville Limestone range from 0.8 to 0.5%. A large number of cavities have been intersected during drilling activities in nearly all zones of the Maynardville Limestone in Bear Creek Valley. Therefore, any maynardville Limestone zone within approximately 200 ft of the ground surface is likely to contain cavities that allow significant and rapid flow of groundwater. Zone 6 could be an important stratigraphic unit in the Maynardville Limestone for groundwater flow and contaminant transport because of the abundance of vuggy and moldic porosities. There are large variations in the thickness and lithology in the lower part of the Maynardville (Zones 2, 3, and 4 in the Burial Grounds region). The direction and velocity of strike-parallel groundwater flow may be altered in this area within the lower Maynardville Limestone.

  9. Exploratory and basic fluidized-bed combustion studies. Quarterly report, April-June 1980. [Limestone and dolomite; USA

    SciTech Connect (OSTI)

    Johnson, I.; Myles, K.M.; Swift, W.M.

    1980-12-01

    This work supports the development studies for both atmospheric and pressurized fluidized-bed coal combustion. Laboratory and process development studies are aimed at providing needed information on limestone utilization, removal of particles and alkali metal compounds from the flue gas, control of SO/sub 2/ and trace pollutant emissions, and other aspects of fluidized-bed coal combustion. This report presents information on: (1) the development of a sorbent utilization prediction methodology, (2) studies of factors which affect limestone breakup and elutriation, (3) basic studies of limestone sulfation under combustion conditions, and (4) studies of the kinetics of the hydration of spent limestone.

  10. Early Permian deep-water allochthonous limestone facies and reservoir, west Texas

    SciTech Connect (OSTI)

    Hobson, J.P.; Caldwell, C.D.; Toomey, D.F.

    1985-12-01

    Conventional cores from six wells in southwest Reagan and northern Crockett Counties, Texas, recovered interbedded limestone conglomerate, intraclast and bioclast limestone, calcarenite, and shale. Twenty-one lithologies are grouped into six lithofacies based on study of slabbed core surfaces. The limestone facies are interpreted on the basis of petrologic characteristics, biota regional stratigraphic setting, and facies stratigraphy as deep water and allochthonous. Biotic constituents within the lithoclasts and matrix indicate an Early Permian (Wolfcamp) age. Age and facies determinations from cores in the Gunnx area significantly alter earlier stratigraphic interpretations made with wireline logs alone. Late Paleozoic allochthonous carbonate facies may provide significant new reserves in the Permian basin. 19 figures, 2 tables.

  11. Rapid method to determine actinides and 89/90Sr in limestone and marble samples

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

    Maxwell, Sherrod L.; Culligan, Brian; Hutchison, Jay B.; Utsey, Robin C.; Sudowe, Ralf; McAlister, Daniel R.

    2016-04-12

    A new method for the determination of actinides and radiostrontium in limestone and marble samples has been developed that utilizes a rapid sodium hydroxide fusion to digest the sample. Following rapid pre-concentration steps to remove sample matrix interferences, the actinides and 89/90Sr are separated using extraction chromatographic resins and measured radiometrically. The advantages of sodium hydroxide fusion versus other fusion techniques will be discussed. Lastly, this approach has a sample preparation time for limestone and marble samples of <4 hours.

  12. Development of Integrated Die Casting Process for Large Thin-Wall Magnesium Applications Enabling Production of Lightweight Magnesium Parts for Near-Term Automotive Applications

    Office of Energy Efficiency and Renewable Energy (EERE)

    Development of Integrated Die Casting Process for Large Thin-Wall Magnesium Applications Enabling Production of Lightweight Magnesium Parts for Near-Term Automotive Applications

  13. Lithium-aluminum-magnesium electrode composition

    DOE Patents [OSTI]

    Melendres, Carlos A.; Siegel, Stanley

    1978-01-01

    A negative electrode composition is presented for use in a secondary, high-temperature electrochemical cell. The cell also includes a molten salt electrolyte of alkali metal halides or alkaline earth metal halides and a positive electrode including a chalcogen or a metal chalcogenide as the active electrode material. The negative electrode composition includes up to 50 atom percent lithium as the active electrode constituent and a magnesium-aluminum alloy as a structural matrix. Various binary and ternary intermetallic phases of lithium, magnesium, and aluminum are formed but the electrode composition in both its charged and discharged state remains substantially free of the alpha lithium-aluminum phase and exhibits good structural integrity.

  14. Lead magnesium niobate actuator for micropositioning

    DOE Patents [OSTI]

    Swift, C.D.; Bergum, J.W.

    1994-10-25

    An improved lead magnesium niobate actuator is disclosed comprising a cylindrical lead magnesium niobate crystal stack mounted in a cylindrical casing wherein a bias means, such as one or more belleville washers, is located between one end of the crystal stack and a partially closed end of the casing; and adjustment means are provided which bear against the opposite end of the crystal stack, whereby an adjustable compressive force is constantly applied against the crystal stack, whether the crystal stack is actuated in an extended position, or is in an unactuated contracted position. In a preferred embodiment, cooling ports are provided for the circulation of coolant in the actuator to cool the crystal stack, and provision is made for removal and replacement of the crystal stack without disconnecting the actuator from the external device being actuated. 3 figs.

  15. Lead magnesium niobate actuator for micropositioning

    SciTech Connect (OSTI)

    Swift, Charles D.; Bergum, John W.

    1994-01-01

    An improved lead magnesium niobate actuator is disclosed comprising a cylindrical lead magnesium niobate crystal stack mounted in a cylindrical casing wherein a bias means, such as one or more belleville washers, is located between one end of the crystal stack and a partially closed end of the casing; and adjustment means are provided which bear against the opposite end of the crystal stack, whereby an adjustable compressive force is constantly applied against the crystal stack, whether the crystal stack is actuated in an extended position, or is in an unactuated contracted position. In a preferred embodiment, cooling ports are provided for the circulation of coolant in the actuator to cool the crystal stack, and provision is made for removal and replacement of the crystal stack without disconnecting the actuator from the external device being actuated.

  16. Impurity control and corrosion resistance of magnesium-aluminum alloy

    SciTech Connect (OSTI)

    Liu, M. [GM China Lab] [GM China Lab; Song, GuangLing [ORNL] [ORNL

    2013-01-01

    The corrosion resistance of magnesium alloys is very sensitive to the contents of impurity elements such as iron. In this study, a series of diecast AXJ530 magnesium alloy samples were prepared with additions of Mn and Fe. Through a comprehensive phase diagram calculation and corrosion evaluation, the mechanisms for the tolerance limit of Fe in magnesium alloy are discussed. This adds a new dimension to control the alloying impurity in terms of alloying composition design and casting conditions.

  17. MAGNESIUM-BASED METHODS, SYSTEMS, AND DEVICES - Energy Innovation...

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

    Materials for Magnesium Batteries and Metal Anodes Abstract: An aspect of the present invention is an electrical device, where the device includes a current collector and a porous...

  18. Shear Rolling of Magnesium Sheet for Automotive, Defense, and...

    Office of Scientific and Technical Information (OSTI)

    Shear Rolling of Magnesium Sheet for Automotive, Defense, and Energy Applications Citation ... Visit OSTI to utilize additional information resources in energy science and technology. A ...

  19. Shear Rolling of Magnesium Sheet for Automotive, Defense, and...

    Office of Scientific and Technical Information (OSTI)

    Title: Shear Rolling of Magnesium Sheet for Automotive, Defense, and Energy Applications Authors: Muralidharan, Govindarajan 1 ; Muth, Thomas R 1 ; Peter, William H 1 ; ...

  20. Scale-Up of Magnesium Production by Fully Stabilized Zirconia...

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

    More Documents & Publications Solid Oxide Membrane (SOM) Electrolysis of Magnesium: Scale-Up Research and Engineering for Light-Weight Vehicles Vehicle Technologies Office Merit ...

  1. Demonstration of Magnesium Intercalation into a High-Voltage...

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

    17, 2015, Research Highlights Demonstration of Magnesium Intercalation into a High-Voltage ... Scientific Achievement First demonstration of reversible insertion of multivalent ...

  2. Rechargeable Magnesium Batteries: Low-Cost Rechargeable Magnesium Batteries with High Energy Density

    SciTech Connect (OSTI)

    2010-10-01

    BEEST Project: Pellion Technologies is developing rechargeable magnesium batteries that would enable an EV to travel 3 times farther than it could using Li-ion batteries. Prototype magnesium batteries demonstrate excellent electrochemical behavior; delivering thousands of charge cycles with very little fade. Nevertheless, these prototypes have always stored too little energy to be commercially viable. Pellion Technologies is working to overcome this challenge by rapidly screening potential storage materials using proprietary, high-throughput computer models. To date, 12,000 materials have been identified and analyzed. The resulting best materials have been electrochemically tested, yielding several very promising candidates.

  3. Petrography study of two siliceous limestones submitted to alkali-silica reaction

    SciTech Connect (OSTI)

    Monnin, Y. . E-mail: monnin@ensm-douai.fr; Degrugilliers, P.; Bulteel, D.; Garcia-Diaz, E.

    2006-08-15

    This study presents the contribution of petrography to the comprehension of the alkali-silica reaction mechanism applied to two siliceous limestones. A petrography study was made on the two aggregates before reaction to define their relative proportions and types of reactive silica and to observe their distribution in the microstructure. Then a model reactor, constituted by the reactive siliceous limestone aggregate, portlandite and NaOH, was used to measure the swelling due to reaction of the silica with alkalis and the free expansion of the aggregates. The volume evolution between both aggregates was very different and could be explained by the preliminary petrographic study. It appears that the swelling of the aggregates is conditioned by the microstructure of the carbonated matrix, the quantity and the distribution of the reactive silica.

  4. A Novel Treatment for Acid Mine Drainage Utilizing Reclaimed Limestone Residual

    SciTech Connect (OSTI)

    Horace K. Moo-Young; Charles E. Ochola

    2004-08-31

    The viability of utilizing Reclaimed Limestone Residual (RLR) to remediate Acid Mine Drainage (AMD) was investigated. Physical and chemical characterization of RLR showed that it is composed of various minerals that contain significant quantities of limestone or calcium bearing compounds that can be exploited for acid neutralization. Acid Neutralization Potential (ANP) test results showed that RLR has a neutralization potential of approximately 83% as calcium carbonate (CaCO{sub 3}). Neutralization tests with most of the heavy metals associated with AMD showed removal efficiencies of over 99%. An unexpected benefit of utilizing RLR was the removal of hexavalent chromium Cr (VI) from the aqueous phase. Due to an elevation in pH by RLR most AMD heavy metals are removed from solution by precipitation as their metal hydroxides. Cr (VI) however is not removed by pH elevation and therefore subsequent ongoing tests to elucidate the mechanism responsible for this reaction were conducted.

  5. Large-scale exploratory tests of sodium/limestone concrete interactions. [LMFBR

    SciTech Connect (OSTI)

    Randich, E.; Smaardyk, J.E.; Acton, R.U.

    1983-02-01

    Eleven large-scale tests examining the interaction of molten sodium and limestone (calcite) concrete were performed. The tests typically used between 100 and 200 kg of sodium at temperatures between 723 K and 973 K and a total sodium/concrete contact area of approx. 1.0m/sup 2/. The results show that energetic reactions can occur between sodium and limestone concrete. Delay times of less than 30 minutes were observed before the onset of the energetic phase. Not all tests exhibited energetic reactions and the results indicate that there is a sodium temperature threshold of 723 K to 773 K which is necessary to initiate the energetic phase. Maximum heat fluxes during the energetic phase were measured at 3.6 x 10/sup 5/ J/m/sup 2/-s. Maximum penetration rates were 4 mm/min. Total concrete erosion varied from 1 to 15 cm.

  6. Intermediate-scale sodium-concrete reaction tests with basalt and limestone concrete

    SciTech Connect (OSTI)

    Hassberger, J.A.; Muhlestein, L.D.

    1981-01-01

    Ten tests were performed to investigate the chemical reactions and rate and extent of attack between sodium and basalt and limestone concretes. Test temperatures ranged from 510 to 870/sup 0/C (950 to 1600/sup 0/F) and test times from 2 to 24 hours. Sodium hydroxide was added to some of the tests to assess the impact of a sodium hydroxide-aided reaction on the overall penetration characteristics. Data suggest that the sodium penetration of concrete surfaces is limited. Penetration of basalt concrete in the presence of sodium hydroxide is shown to be less severe than attack by the metallic sodium alone. Presence of sodium hydroxide changes the characteristics of sodium penetration of limestone concrete, but no major differences in bulk penetration were observed as compared to penetration by metallic sodium.

  7. Casting Porosity-Free Grain Refined Magnesium Alloys

    SciTech Connect (OSTI)

    Schwam, David

    2013-08-12

    The objective of this project was to identify the root causes for micro-porosity in magnesium alloy castings and recommend remedies that can be implemented in production. The findings confirm the key role played by utilizing optimal gating and risering practices in minimizing porosity in magnesium castings. 

  8. DOE - Office of Legacy Management -- St Louis Airport - MO 01

    Office of Legacy Management (LM)

    - MO 01 FUSRAP Considered Sites St. Louis Airport, MO Alternate Name(s): Airport Site St. Louis Airport Storage Site (SLAPS) Former Robertson Storage Area Robertson Airport MO.01-1 MO.01-2 Location: Brown Road, Robertson, Missouri MO.01-2 Historical Operations: Stored uranium process residues containing uranium, radium, and thorium for the MED and AEC. MO.01-2 MO.01-3 MO.01-4 Eligibility Determination: Eligible MO.01-1 MO.01-7 Radiological Survey(s): Assessment Surveys MO.01-4 MO.01-5 Site

  9. Mo-Si alloy development

    SciTech Connect (OSTI)

    Liu, C.T.; Heatherly, L.; Wright, J.L.

    1996-06-01

    The objective of this task is to develop new-generation corrosion-resistant Mo-Si intermetallic alloys as hot components in advanced fossil energy conversion and combustion systems. The initial effort is devoted to Mo{sub 5}-Si{sub 3}-base (MSB) alloys containing boron additions. Three MSB alloys based on Mo-10.5Si-1.1B (wt %), weighing 1500 g were prepared by hot pressing of elemental and alloy powders at temperatures to 1600{degrees}C in vacuum. Microporosities and glassy-phase (probably silicate phases) formations are identified as the major concerns for preparation of MSB alloys by powder metallurgy. Suggestions are made to alleviate the problems of material processing.

  10. Synthesis of nanoscale magnesium diboride powder

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

    Finnemore, D. K.; Marzik, J. V.

    2015-12-18

    A procedure has been developed for the preparation of small grained magnesium diboride (MgB2) powder by reacting nanometer size boron powder in a magnesium vapor. Plasma synthesized boron powder that had particle sizes ranging from 20 to 300nm was mixed with millimeter size chunks of Mg by rolling stoichiometric amounts of the powders in a sealed cylindrical container under nitrogen gas. This mixture then was placed in a niobium reaction vessel, evacuated, and sealed by e-beam welding. The vessel was typically heated to approximately 830°C for several hours. The resulting MgB2 particles have a grain size in the 200 nmmore » to 800 nm range. Agglomerates of loosely bound particles could be broken up by light grinding in a mortar and pestle. At 830°C, many particles are composed of several grains grown together so that the average particle size is about twice the average grain size. Furthermore, experiments were conducted primarily with undoped boron powder, but carbon-doped boron powder showed very similar results.« less

  11. Synthesis of nanoscale magnesium diboride powder

    SciTech Connect (OSTI)

    Finnemore, D. K.; Marzik, J. V.

    2015-12-18

    A procedure has been developed for the preparation of small grained magnesium diboride (MgB2) powder by reacting nanometer size boron powder in a magnesium vapor. Plasma synthesized boron powder that had particle sizes ranging from 20 to 300nm was mixed with millimeter size chunks of Mg by rolling stoichiometric amounts of the powders in a sealed cylindrical container under nitrogen gas. This mixture then was placed in a niobium reaction vessel, evacuated, and sealed by e-beam welding. The vessel was typically heated to approximately 830°C for several hours. The resulting MgB2 particles have a grain size in the 200 nm to 800 nm range. Agglomerates of loosely bound particles could be broken up by light grinding in a mortar and pestle. At 830°C, many particles are composed of several grains grown together so that the average particle size is about twice the average grain size. Furthermore, experiments were conducted primarily with undoped boron powder, but carbon-doped boron powder showed very similar results.

  12. Optimization of the Processing of Mo Disks

    SciTech Connect (OSTI)

    Tkac, Peter; Rotsch, David A.; Stepinski, Dominique; Makarashvili, Vakhtang; Harvey, James; Vandegrift, George F.

    2016-01-01

    The objective of this work is to decrease the processing time for irradiated disks of enriched Mo for the production of 99Mo. Results are given for the dissolution of nonirradiated Mo disks, optimization of the process for large-scale dissolution of sintered disks, optimization of the removal of the main side products (Zr and Nb) from dissolved targets, and dissolution of irradiated Mo disks.

  13. SSL Demonstration: Street Lighting, Kansas City, MO

    SciTech Connect (OSTI)

    2013-08-01

    GATEWAY program report brief summarizing an SSL street lighting demonstration at nine separate installations in Kansas City, MO.

  14. Process for converting magnesium fluoride to calcium fluoride

    DOE Patents [OSTI]

    Kreuzmann, A.B.; Palmer, D.A.

    1984-12-21

    This invention is a process for the conversion of magnesium fluoride to calcium fluoride whereby magnesium fluoride is decomposed by heating in the presence of calcium carbonate, calcium oxide or calcium hydroxide. Magnesium fluoride is a by-product of the reduction of uranium tetrafluoride to form uranium metal and has no known commercial use, thus its production creates a significant storage problem. The advantage of this invention is that the quality of calcium fluoride produced is sufficient to be used in the industrial manufacture of anhydrous hydrogen fluoride, steel mill flux or ceramic applications.

  15. Magnesium Replacement of Aluminum Cast Components in a Production...

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

    Replacement of Aluminum Cast Components in a Production V6 Engine to Effect Cost-Effective Mass Reduction Magnesium Replacement of Aluminum Cast Components in a Production V6 ...

  16. Ames Lab 101: BAM (Boron-Aluminum-Magnesium)

    ScienceCinema (OSTI)

    Bruce Cook

    2013-06-05

    Materials scientist, Bruce Cook, discusses the super hard, low friction, and lubricious alloy know as BAM (Boron-Aluminum-Magnesium). BAM was discovered by Bruce Cook and his team a

  17. Water quality changes in acid mine drainage streams in Gangneung, Korea, 10 years after treatment with limestone

    SciTech Connect (OSTI)

    Shim, Moo Joon; Choi, Byoung Young; Lee, Giehyeon; Hwang, Yun Ho; Yang, Jung-Seok; O'Loughlin, Edward J.; Kwon, Man Jae

    2015-12-01

    To determine the long-term effectiveness of the limestone treatment for acid mine drainage (AMD) in Gangneung, Korea, we investigated the elemental distribution in streams impacted by AMD and compared the results of previous studies before and approximately 10 years after the addition of limestone. Addition of limestone in 1999 leads to a pH increase in 2008, and with the exception of Ca, the elemental concentrations (e.g., Fe, Mn, Mg, Sr, Ni, Zn, S) in the streams decreased. The pH was 2.5–3 before the addition of limestone and remained stable at around 4.5–5 from 2008 to 2011, suggesting the reactivity of the added limestone was diminished and that an alternative approach is needed to increase the pH up to circumneutral range and maintain effective long-term treatment. To identify the processes causing the decrease in the elemental concentrations, we also examined the spatial (approximately 7 km) distribution over three different types of streams affected by the AMD. The elemental distribution was mainly controlled by physicochemical processes including redox reactions, dilution on mixing, and co-precipitation/adsorption with Fe (hydr)oxides.

  18. Water-rock interaction during meteoric flushing of a limestone: Implications for porosity development in karstified petroleum reservoirs

    SciTech Connect (OSTI)

    Smalley, P.C. ); Bishop, P.K. . School of Earth Sciences); Dickson, J.A.D. . Dept. of Earth Sciences); Emery, D. )

    1994-04-01

    The Lincolnshire Limestone, comprising a succession of Jurassic wackestones, packstones, and oolitic grainstones, forms an important carbonate aquifer in eastern England. Meteoric waters enter at outcrop and penetrate between confining strata at least 25 km down-dip. This water dissolves and interacts with the limestone, and even water samples collected at or near outcrop are calcite-saturated. Net limestone dissolution is thus a process that is most dominant in the near-surface environment. Water samples taken at increasing distances from outcrop have increasing Sr and Mg contents, and [delta][sup 13]C values of dissolved bicarbonate increase from [minus]15[per thousand] to [minus]8[per thousand] (PDB), while [sup 87]Sr/[sup 86]Sr falls from 0.7082 to 0.7077. Isotopically light bulk-rock carbon near joint surfaces suggests that reprecipitation of calcite in the form of cement could be concentrated preferentially in and near joints. The Lincolnshire Limestone may be used as an analogue for karstified petroleum reservoirs, specifically those which have been buried and lost their unstable carbonate minerals (aragonite, high-Mg calcite) prior to uplift and karstification. The present water chemical data suggest that, in such reservoirs, influx of meteoric water at an unconformity creates porosity and enhances permeability through limestone dissolution, but this may be concentrated close (tens of meters) to the unconformity. Such factors should be taken into account when exploring for, and appraising, karstified petroleum reservoirs.

  19. Reversible Magnesium Intercalation into a Layered Oxyfluoride Cathode -

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

    Joint Center for Energy Storage Research December 18, 2015, Research Highlights Reversible Magnesium Intercalation into a Layered Oxyfluoride Cathode Powder diffraction of oxyfluoridecathode with intercalated Mg and capacities of oxyfluorideand oxide cathodes Scientific Achievement Magnesium was reversibly intercalated at room temperature into an oxyfluoride cathode without the co-intercalation of electrolytes or protons and without the formation of unwanted side-products that commonly

  20. Interface-Induced Renormalization of Electrolyte Energy Levels in Magnesium

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

    Batteries - Joint Center for Energy Storage Research February 17, 2016, Research Highlights Interface-Induced Renormalization of Electrolyte Energy Levels in Magnesium Batteries Renormalization of solvent HOMO (green lines) and LUMO (red lines) levels due to interactions with Mg (0001) and MgO (001). The shaded region in the center of the figure represents the electrochemical window of a hypothetical 4V magnesium battery Scientific Achievement Interface-induced changes to the stability of

  1. Formation of chemically bonded ceramics with magnesium dihydrogen phosphate binder

    DOE Patents [OSTI]

    Wagh, Arun S.; Jeong, Seung-Young

    2004-08-17

    A new method for combining magnesium oxide, MgO, and magnesium dihydrogen phosphate to form an inexpensive compactible ceramic to stabilize very low solubility metal oxides, ashes, swarfs, and other iron or metal-based additives, to create products and waste forms which can be poured or dye cast, and to reinforce and strengthen the ceramics formed by the addition of fibers to the initial ceramic mixture.

  2. BACKGROUND REVIEW OF THE BRUSH BERYLLIUM AND DIAMOND MAGNESIUM PLANTS

    Office of Legacy Management (LM)

    BACKGROUND REVIEW OF THE BRUSH BERYLLIUM AND DIAMOND MAGNESIUM PLANTS IN LUCKEY, OHIO October 27, 1989 Prepared for: U.S. Department of Energy Formerly Utilized Sites Remedial Action Program Prepared by: R.F. Weston/Office of Technical Services BACKGROUND REVIEW OF THE BRUSH BERYLLIUM AND DIAMOND MAGNESIUM PLANTS IN LUCKEY, OHIO INTRODUCTION The Department of Energy (DOE) is conducting a program to identify and examine the radiological conditions at sites used in the early years of nuclear

  3. Measurement of the direct CP -violating parameter ACP in the decay D<mo>+ stretchy='false'>→mo>K<mo>-mo>π<mo>+mo>π+>

    SciTech Connect (OSTI)

    Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Agnew, J. P.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Borysova, M.; Brandt, A.; Brandt, O.; Brock, R.; Bross, A.; Brown, D.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C. P.; Camacho-Pérez, E.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M. -C.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dubey, A.; Dudko, L. V.; Duperrin, A.; Dutt, S.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, V. N.; Fauré, A.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garbincius, P. H.; Garcia-Bellido, A.; García-González, J. A.; Gavrilov, V.; Geng, W.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Gogota, O.; Golovanov, G.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph.; Grivaz, J. -F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hogan, J.; Hohlfeld, M.; Holzbauer, J. L.; Howley, I.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jayasinghe, A.; Jeong, M. S.; Jesik, R.; Jiang, P.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kajfasz, E.; Karmanov, D.; Katsanos, I.; Kaur, M.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kiselevich, I.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kumar, A.; Kupco, A.; Kurča, T.; Kuzmin, V. A.; Lammers, S.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lei, X.; Lellouch, J.; Li, D.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V. L.; Mansour, J.; Martínez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Mulhearn, M.; Nagy, E.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nguyen, H. T.; Nunnemann, T.; Orduna, J.; Osman, N.; Osta, J.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Pleier, M. -A.; Podstavkov, V. M.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Ratoff, P. N.; Razumov, I.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Sajot, G.; Sánchez-Hernández, A.; Sanders, M. P.; Santos, A. S.; Savage, G.; Savitskyi, M.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shaw, S.; Shchukin, A. A.; Simak, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.; Soustruznik, K.; Stark, J.; Stoyanova, D. A.; Strauss, M.; Suter, L.; Svoisky, P.; Titov, M.; Tokmenin, V. V.; Tsai, Y. -T.; Tsybychev, D.; Tuchming, B.; Tully, C.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Van Kooten, R.; van Leeuwen, W. M.; Varelas, N.; Varnes, E. W.; Vasilyev, I. A.; Verkheev, A. Y.; Vertogradov, L. S.; Verzocchi, M.; Vesterinen, M.; Vilanova, D.; Vokac, P.; Wahl, H. D.; Wang, M. H. L. S.; Warchol, J.; Watts, G.; Wayne, M.; Weichert, J.; Welty-Rieger, L.; Williams, M. R. J.; Wilson, G. W.; Wobisch, M.; Wood, D. R.; Wyatt, T. R.; Xie, Y.; Yamada, R.; Yang, S.; Yasuda, T.; Yatsunenko, Y. A.; Ye, W.; Ye, Z.; Yin, H.; Yip, K.; Youn, S. W.; Yu, J. M.; Zennamo, J.; Zhao, T. G.; Zhou, B.; Zhu, J.; Zielinski, M.; Zieminska, D.; Zivkovic, L.

    2014-12-01

    We measure the direct CP-violating parameter ACP for the decay of the charged charm meson, Dmo>+ stretchy="false">→mo>Kmo>-mo>πmo>+mo>πmo>+> (and charge conjugate), using the full 10.4 fbmo>->1 sample of ppmo accent="true" stretchy="false">¯mo> collisions at smo>=>1.96 TeV collected by the D0 detector at the Fermilab Tevatron collider. We extract the raw reconstructed charge asymmetry by fitting the invariant mass distributions for the sum and difference of charge-specific samples. This quantity is then corrected for detector-related asymmetries using data-driven methods and for possible physics asymmetries (from Bmo stretchy="false">→mo

  4. Layered materials with improved magnesium intercalation for rechargeable magnesium ion cells

    DOE Patents [OSTI]

    Doe, Robert Ellis; Downie, Craig Michael; Fischer, Christopher; Lane, George Hamilton; Morgan, Dane; Nevin, Josh; Cedar, Gerbrand; Persson, Kristin Aslaug; Eaglesham, David

    2015-11-05

    Electrochemical devices which incorporate cathode materials that include layered crystalline compounds for which a structural modification has been achieved which increases the diffusion rate of multi-valent ions into and out of the cathode materials. Examples in which the layer spacing of the layered electrode materials is modified to have a specific spacing range such that the spacing is optimal for diffusion of magnesium ions are presented. An electrochemical cell comprised of a positive intercalation electrode, a negative metal electrode, and a separator impregnated with a nonaqeuous electrolyte solution containing multi-valent ions and arranged between the positive electrode and the negative electrode active material is described.

  5. Layered materials with improved magnesium intercalation for rechargeable magnesium ion cells

    DOE Patents [OSTI]

    Doe, Robert Ellis; Downie, Craig Michael; Fischer, Christopher; Lane, George Hamilton; Morgan, Dane; Nevin, Josh; Ceder, Gerbrand; Persson, Kristin Aslaug; Eaglesham, David

    2015-10-27

    Electrochemical devices which incorporate cathode materials that include layered crystalline compounds for which a structural modification has been achieved which increases the diffusion rate of multi-valent ions into and out of the cathode materials. Examples in which the layer spacing of the layered electrode materials is modified to have a specific spacing range such that the spacing is optimal for diffusion of magnesium ions are presented. An electrochemical cell comprised of a positive intercalation electrode, a negative metal electrode, and a separator impregnated with a nonaqeuous electrolyte solution containing multi-valent ions and arranged between the positive electrode and the negative electrode active material is described.

  6. Layered materials with improved magnesium intercalation for rechargeable magnesium ion cells

    DOE Patents [OSTI]

    Doe, Robert E.; Downie, Craig M.; Fischer, Christopher; Lane, George H.; Morgan, Dane; Nevin, Josh; Ceder, Gerbrand; Persson, Kristin A.; Eaglesham, David

    2016-01-19

    Electrochemical devices which incorporate cathode materials that include layered crystalline compounds for which a structural modification has been achieved which increases the diffusion rate of multi-valent ions into and out of the cathode materials. Examples in which the layer spacing of the layered electrode materials is modified to have a specific spacing range such that the spacing is optimal for diffusion of magnesium ions are presented. An electrochemical cell comprised of a positive intercalation electrode, a negative metal electrode, and a separator impregnated with a nonaqueous electrolyte solution containing multi-valent ions and arranged between the positive electrode and the negative electrode active material is described.

  7. DOE - Office of Legacy Management -- Washington University - MO 07

    Office of Legacy Management (LM)

    Washington University - MO 07 FUSRAP Considered Sites Site: WASHINGTON UNIVERSITY (MO.07 ) Eliminated from consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: St. Louis , Missouri MO.07-1 Evaluation Year: 1987 MO.07-1 Site Operations: Activities were limited to programs involving relatively small quantities of radionuclides and chemicals in a controlled environment. MO.07-3 MO.07-1 Site Disposition: Eliminated - Potential for contamination remote MO.07-1

  8. The Unexpected Discovery of the Mg(HMDS)2/MgCl2 Complex as a Magnesium

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

    Electrolyte for Rechargeable Magnesium Batteries - Joint Center for Energy Storage Research February 2, 2015, Research Highlights The Unexpected Discovery of the Mg(HMDS)2/MgCl2 Complex as a Magnesium Electrolyte for Rechargeable Magnesium Batteries NMR confirms formation of new species Scientific Achievement A simple mixture of magnesium compounds: magnesium hexamethyldisilazide (Mg(HMDS)2) and magnesium chloride (MgCl2) was prepared to achieve reversible Mg deposition/dissolution, a wide

  9. DOE - Office of Legacy Management -- Latty Avenue Site - MO 04

    Office of Legacy Management (LM)

    Latty Avenue Site - MO 04 FUSRAP Considered Sites Latty Avenue Site, MO Alternate Name(s): Futura Coatings Futura Chemical Company Facility Hazelwood Interim Storage Site (HISS) Former Cotter Site, Latty Avenue Properties Contemporary Metals Corp. Continental Mining and Milling MO.04-1 MO.04-2 MO.04-5 MO.04-6 MO.06-8 MO.06-11 Location: 9200 Latty Avenue, Hazelwood, Missouri MO.04-1 Historical Operations: Received, stored, and processed uranium residues for the AEC. Storage and processing were

  10. Laboratory evaluation of limestone and lime neutralization of acidic uranium mill tailings solution. Progress report

    SciTech Connect (OSTI)

    Opitz, B.E.; Dodson, M.E.; Serne, R.J.

    1984-02-01

    Experiments were conducted to evaluate a two-step neutralization scheme for treatment of acidic uranium mill tailings solutions. Tailings solutions from the Lucky Mc Mill and Exxon Highland Mill, both in Wyoming, were neutralized with limestone, CaCO/sub 3/, to an intermediate pH of 4.0 or 5.0, followed by lime, Ca(OH)/sub 2/, neutralization to pH 7.3. The combination limestone/lime treatment methods, CaCO/sub 3/ neutralization to pH 4 followed by neutralization with Ca(OH)/sub 2/ to pH 7.3 resulted in the highest quality effluent solution with respect to EPA's water quality guidelines. The combination method is the most cost-effective treatment procedure tested in our studies. Neutralization experiments to evaluate the optimum solution pH for contaminant removal were performed on the same two tailings solutions using only lime Ca(OH)/sub 2/ as the neutralizing agent. The data indicate solution neutralization above pH 7.3 does not significantly increase removal of pH dependent contaminants from solution. Column leaching experiments were performed on the neutralized sludge material (the precipitated solid material which forms as the acidic tailings solutions are neutralized to pH 4 or above). The sludges were contacted with laboratory prepared synthetic ground water until several effluent pore volumes were collected. Effluent solutions were analyzed for macro ions, trace metals and radionuclides in an effort to evaluate the long term effectiveness of attenuating contaminants in sludges formed during solution neutralization. Neutralized sludge leaching experiments indicate that Ca, Na, Mg, Se, Cl, and SO/sub 4/ are the only constituents which show solution concentrations significantly higher than the synthetic ground water in the early pore volumes of long-term leaching studies.

  11. Development of High-Volume Warm Forming of Low-Cost Magnesium...

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

    High-Volume Warm Forming of Low-Cost Magnesium Sheet Development of High-Volume Warm Forming of Low-Cost Magnesium Sheet 2009 DOE Hydrogen Program and Vehicle Technologies Program ...

  12. Development of High-Volume Warm Forming of Low-Cost Magnesium...

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

    Development of High-Volume Warm Forming of Low-Cost Magnesium Sheet Development of High-Volume Warm Forming of Low-Cost Magnesium Sheet 2010 DOE Vehicle Technologies and Hydrogen ...

  13. Phase Diagram and Equation of State of Magnesium to High Pressures...

    Office of Scientific and Technical Information (OSTI)

    Phase Diagram and Equation of State of Magnesium to High Pressures and High Temperatures Citation Details In-Document Search Title: Phase Diagram and Equation of State of Magnesium ...

  14. Mo99 Production Plant Layout

    SciTech Connect (OSTI)

    Woloshun, Keith Albert; Dale, Gregory E.; Naranjo, Angela Carol

    2015-06-25

    The NorthStar Medical Technologies 99Mo production facility configuration is envisioned to be 8 accelerator pairs irradiating 7 100Mo targets (one spare accelerator pair undergoing maintenance while the other 7 pairs are irradiating targets). The required shielding in every direction for the accelerators is initially estimated to be 10 feet of concrete. With the accelerator pairs on one (ground) level and spaced with the required shielding between adjacent pairs, the only practical path for target insertion and removal while minimizing floor space is vertical. The current scheme then requires a target vertical lift of nominally 10 feet through a shield stack. It is envisioned that the lift will be directly into a hot cell where an activated target can be removed from its holder and a new target attached and lowered. The hot cell is on a rail system so that a single hot cell can service all active target locations, as well as deliver the ready targets to the separations lab. On this rail system, coupled to the hot cell, will be a helium recovery and clean-up system. All helium coolant equipment is located on the upper level near to the target removal point.

  15. A Lewis Acid-free and Phenolate-based Magnesium Electrolyte for

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

    Rechargeable Magnesium Batteries - Joint Center for Energy Storage Research March 2, 2015, Research Highlights A Lewis Acid-free and Phenolate-based Magnesium Electrolyte for Rechargeable Magnesium Batteries X-ray single crystal isolated from the electrolyte containing the prototype [Mg2Cl3(THF)6]+ cation Scientific Achievement A novel Lewis acid-free all magnesium electrolyte containing 2,6-di-tert-butylphenoxidemagnesium chloride ((DTBP)MgCl + MgCl2) has been deliberately developed. The

  16. Nanostructured material for advanced energy storage : magnesium battery cathode development.

    SciTech Connect (OSTI)

    Sigmund, Wolfgang M.; Woan, Karran V.; Bell, Nelson Simmons

    2010-11-01

    Magnesium batteries are alternatives to the use of lithium ion and nickel metal hydride secondary batteries due to magnesium's abundance, safety of operation, and lower toxicity of disposal. The divalency of the magnesium ion and its chemistry poses some difficulties for its general and industrial use. This work developed a continuous and fibrous nanoscale network of the cathode material through the use of electrospinning with the goal of enhancing performance and reactivity of the battery. The system was characterized and preliminary tests were performed on the constructed battery cells. We were successful in building and testing a series of electrochemical systems that demonstrated good cyclability maintaining 60-70% of discharge capacity after more than 50 charge-discharge cycles.

  17. Extreme ultraviolet spectra of highly ionized Ge, Kr and Mo emitted by imploding plasmas

    SciTech Connect (OSTI)

    Goldsmith, S.; Feldman, U.; Cohen, L.; Behring, W.E.

    1984-01-01

    Spectra of highly ionized Ge, Kr and Mo in the spectral region of 10 to 80A were excited in laser-produced plasmas. The plasma was obtained by focusing the energy of the 24 laser beams of the University of Rochester Omega system on 0.4 mm diameter microballoon targets. The laser pulse duration was in the range of 0.87 to 1.09 ns, with total energy in the range of 1.8 to 2.2 kJ. The observed spectral lines include n = 2-2 transitions in the oxygen and fluorine isoelectronic sequences and n = 3 to 4 transitions in the sodium, magnesium and aluminum isoelectronic sequences. The present observations are compared with previous experimental and theoretical studies.

  18. DOE - Office of Legacy Management -- Petrolite Corp - MO 08

    Office of Legacy Management (LM)

    Petrolite Corp - MO 08 FUSRAP Considered Sites Site: PETROLITE CORP (MO.08) Eliminated from further consideration under FUSRAP Designated Name: Not Designated Alternate Name: None Location: St. Louis , Missouri MO.08-1 Evaluation Year: 1987 MO.08-4 Site Operations: Research involving test quantities of radioactive materials. MO.08-2 Site Disposition: Eliminated - Licensed - Potential for contamination remote MO.08-3 Radioactive Materials Handled: Yes Primary Radioactive Materials Handled:

  19. Missouri Department of National Resources Energy Center Mo DNR...

    Open Energy Info (EERE)

    Department of National Resources Energy Center Mo DNR Jump to: navigation, search Name: Missouri Department of National Resources Energy Center (Mo DNR) Place: Jefferson City,...

  20. Tuning the electronic structure of monolayer graphene/ Mo S 2...

    Office of Scientific and Technical Information (OSTI)

    Tuning the electronic structure of monolayer graphene Mo S 2 van der Waals ... Title: Tuning the electronic structure of monolayer graphene Mo S 2 van der Waals ...

  1. Update to M&O Contractor Model Subcontract entitled "Standard...

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

    M&O Contractor Model Subcontract entitled "Standard Research Subcontract (Educational Institution or Nonprofit Organization)" Update to M&O Contractor Model Subcontract entitled ...

  2. DOE - Office of Legacy Management -- West Lake Landfill - MO...

    Office of Legacy Management (LM)

    Lake Landfill - MO 05 FUSRAP Considered Sites Site: West Lake Landfill (MO.05) Designated Name: Alternate Name: Location: Evaluation Year: Site Operations: Site Disposition:...

  3. Demonstration of LED Street Lighting in Kansas City, MO (Technical...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Demonstration of LED Street Lighting in Kansas City, MO Citation Details In-Document Search Title: Demonstration of LED Street Lighting in Kansas City, MO Nine ...

  4. REGENERATION OF FISSION-PRODUCT-CONTAINING MAGNESIUM-THORIUM ALLOYS

    DOE Patents [OSTI]

    Chiotti, P.

    1964-02-01

    A process of regenerating a magnesium-thorium alloy contaminated with fission products, protactinium, and uranium is presented. A molten mixture of KCl--LiCl-MgCl/sub 2/ is added to the molten alloy whereby the alkali, alkaline parth, and rare earth fission products (including yttrium) and some of the thorium and uranium are chlorinated and

  5. Magnesium oxide inserts for the LECO Carbon Analyzer

    SciTech Connect (OSTI)

    Bagaasen, L.M.; Jensen, C.M.

    1991-01-16

    LECO carbon analysis of plutonium metal and plutonium oxide at the Rocky Flats Plant generates several hundred kilograms of high silica residues each year. The plutonium in these residues is difficult and expensive to recover using production dissolution processes. A magnesium oxide (MgO) insert has been developed that significantly lowers the plutonium recovery costs without adversely affecting accuracy of the carbon analysis.

  6. Computational Model of Magnesium Deposition and Dissolution for Property

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

    Determination via Cyclic Voltammetry - Joint Center for Energy Storage Research June 23, 2016, Research Highlights Computational Model of Magnesium Deposition and Dissolution for Property Determination via Cyclic Voltammetry Top: Example distributions of the charge transfer coefficient and standard heterogeneous rate constant, obtained from fitting Bottom: Comparison between experimental and simulated voltammograms, demonstrating good agreement Scientific Achievement A computationally

  7. Thermophysical Properties of U-10MO Alloy

    SciTech Connect (OSTI)

    A. M. Phillips; G. S. Mickum; D. E. Burkes

    2010-11-01

    This report provides an overview of thermophysical properties of unirradiated uranium alloyed with ten weight percent molybdenum (U 10Mo), with particular focus on those material properties needed for modeling of new fuels for HPRRs (High Performance Research Reactors). The report contains both historical data available in the literature on U-10Mo, as well as more recent results conducted by the Global Threat Reduction Initiative fuel development program. The main use of the report is intended as a standard U-10Mo alloy properties reference for reactor models and simulations.

  8. The Mississippian Leadville Limestone Exploration Play, Utah and Colorado-Exploration Techniques and Studies for Independents

    SciTech Connect (OSTI)

    Thomas Chidsey

    2008-09-30

    The Mississippian (late Kinderhookian to early Meramecian) Leadville Limestone is a shallow, open-marine, carbonate-shelf deposit. The Leadville has produced over 53 million barrels (8.4 million m{sup 3}) of oil/condensate from seven fields in the Paradox fold and fault belt of the Paradox Basin, Utah and Colorado. The environmentally sensitive, 7500-square-mile (19,400 km{sup 2}) area that makes up the fold and fault belt is relatively unexplored. Only independent producers operate and continue to hunt for Leadville oil targets in the region. The overall goal of this study is to assist these independents by (1) developing and demonstrating techniques and exploration methods never tried on the Leadville Limestone, (2) targeting areas for exploration, (3) increasing deliverability from new and old Leadville fields through detailed reservoir characterization, (4) reducing exploration costs and risk especially in environmentally sensitive areas, and (5) adding new oil discoveries and reserves. The final results will hopefully reduce exploration costs and risks, especially in environmentally sensitive areas, and add new oil discoveries and reserves. The study consists of three sections: (1) description of lithofacies and diagenetic history of the Leadville at Lisbon field, San Juan County, Utah, (2) methodology and results of a surface geochemical survey conducted over the Lisbon and Lightning Draw Southeast fields (and areas in between) and identification of oil-prone areas using epifluorescence in well cuttings from regional wells, and (3) determination of regional lithofacies, description of modern and outcrop depositional analogs, and estimation of potential oil migration directions (evaluating the middle Paleozoic hydrodynamic pressure regime and water chemistry). Leadville lithofacies at Libon field include open marine (crinoidal banks or shoals and Waulsortian-type buildups), oolitic and peloid shoals, and middle shelf. Rock units with open-marine and restricted

  9. Diagenetic features of Trenton Limestone in northern Indiana: petrographic evidence for Late (Mesogenetic) Dolostone

    SciTech Connect (OSTI)

    Fara, D.R.

    1986-08-01

    Three conventional cores of the entire Trenton section were examined in detail by in-depth visual description, analysis of more than 250 thin sections, scanning electron microscopy, and x-ray diffraction. The cores are located in the northern half of Indiana where they span the major dolostone pinch-out that is the trap for the prolific Trenton oil and gas field. The Trenton Limestone is completely dolomitized in northern Indiana. Dolostone abundance decreases to the south where the dolostone is restricted to the upper few feet of the formation. Two major types of dolostone are recognized. The top 5-20 ft of the Trenton cores consists of medium crystalline nonporous xenotopic ferroan dolostone. Mesogenetic dewatering of the overlying Maquoketa shale is the proposed dolomitizing mechanisms for this ferroan dolostone cap. Below the ferroan dolostone cap in northern Indiana is coarsely crystalline dolostone, which consists of thin intercalated subfacies of porous idiotopic and nonporous xenotopic dolostone. This is the dominant dolostone type and is the reservoir in the Trenton field. The coarsely crystalline dolostone postdates the ferroan dolostone cap, chert nodule formation, and initial pressure solution. Therefore, this dolostone is considered to have formed relatively late in the diagenetic history of the Trenton under mesogenetic conditions. In the northernmost core, nearly all of the secondary dolomitic porosity is plugged by poikilotopic gypsum and minor amounts of calcite and celestite. Other diagenetic features observed in Trenton are also discussed, including silicification, ferroan calcite cement, upper Trenton contact formation, hardgrounds, and pressure solution.

  10. Re-examination of laminated osagid grains from a Lower Permian midcontinent limestone

    SciTech Connect (OSTI)

    Toomey, D.F. ); Lowenstein, T.K. ); Mitchell, R.W. )

    1989-02-01

    Osagid grains from the Lower Permian (Wolfcamp) Winfield Limestone of southern Kansas-northern Oklahoma are small accretionary structures formed in shallow, well-agitated waters on a carbonate shelf. Osagid grains consist of small shell fragments serving as nuclei, which during formation were rolled about and coated by roughly concentric algal-foraminiferal laminations. Their shapes range from round to subround to elliptical, dependent primarily on the size and shape of the shell nuclei. Grain laminae are dark micrite which in places contain tubules of the blue-green alga Girvanella, and/or various encrusting foraminifers, with either calcareous or agglutinated tests, or intermixtures of all three components. Formic acid etching of individual osagid grains indicates that the agglutinated foraminiferal component is of greater importance than previously believed and can be their principal biotic component. Girvanella tubules appear to be most susceptible to diagenetic alteration, with the end-product generally a dark, micritic groundmass of algal dust. Since these accretionary structures are not true biological species, the generic term Osagia should be dropped and these structures should be called osgid grains.

  11. Cycle stratigraphy and porosity in Pennsylvanian and Lower Permian shelf limestones, eastern Central Basin Platform, Texas

    SciTech Connect (OSTI)

    Saller, A.H.; Dickson, J.A.D.; Boyd, S.A.

    1994-12-01

    Pennyslvanian and Lower Permian shelfal limestones were studied in core and wireline logs on the eastern side of the Central Basin platform in west Texas. Sixty-three (63) cycles were delineated in the study interval, which includes 200-250 m of Canyon (Missourian), Cisco (Virgilian), and Wolfcamp strata. Four general lithofacies are present: fossiliferous wackestones and packstones, grainstones, phylloid algal boundstones, and shales. These lithologies typically occur in 1-18-m-thick cycles bounded by subaerial exposure surfaces. Grainstones in the upper part of some cycles indicate a shallowing of environments prior to subaerial exposure. Many cycles have subaerial exposure surfaces developed on subtidal fossiliferous wackestones or packstones suggesting rapid falls in sea level. Long-term transgressive intervals (transgressive systems tracts or TST) are dominated by thick (>4 m) cycles, whereas long-term regressive intervals (highstand systems tract or HST) are dominated by thinner cycles. Stable carbon isotope data suggest that thick cycles in TSTs were subjected to short periods of subaerial exposure, whereas thin cycles in the HSTs were subjected to much longer subaerial exposure. Where present, reservoir-grade porosity occurs in the upper part of cycles, 0.3-5 m below subaerial exposure surfaces. Prolonged subaerial exposure apparently reduced matrix porosity by allowing more time for calcite precipitation, which was especially effective in reducing porosity in micritic strata below exposure surfaces.

  12. Mo Year Report Period: EIA ID NUMBER:

    U.S. Energy Information Administration (EIA) Indexed Site

    Mo Year Report Period: EIA ID NUMBER: http:www.eia.govsurveyformeia14instructions.pdf Mailing Address: Secure File Transfer option available at: (e.g., PO Box, RR) https:...

  13. The economic impact of removing chloride from closed-loop wet limestone FGD systems. Volume 1. Final report

    SciTech Connect (OSTI)

    Phillips, J.L.; Horton, W.M.

    1995-01-01

    High chloride concentrations in wet limestone FGD systems increase the corrosion rates of certain materials and decrease SO{sub 2} removal efficiency and limestone utilization. This study revealed four different technologies that could be used to control chloride concentrations in closed-loop wet limestone FGD systems: reverse osmosis, electrodialysis reversal, vapor compression evaporation, and duct injection. This two-volume report describes each option in detail, discusses the basis for selecting the chloride threshold levels along with approximate cost estimates for combined chloride removal and waste disposal options, and presents flow sheets and detailed material balances for the least-cost combined options. The total annualized costs for chloride removal and waste disposal estimated in this study for a 300-MW plant range from 0.8 to 1.3 mils/kWh for controlling chloride at 3000 ppm to prevent corrosion and range from 0.3 to 0.7 mils/kWh for controlling chloride at 15,000 ppm to prevent decreased SO{sub 2} removal. The design coal has a relatively high chloride-to-sulfur ratio; costs for other coals would be lower.

  14. The economic impact of removing chloride from closed-loop wet limestone GFD systems. Volume 2. Final report

    SciTech Connect (OSTI)

    Phillips, J.L.; Horton, W.M.

    1995-01-01

    High chloride concentrations in wet limestone FGD systems increase the corrosion rates of certain materials and decrease SO{sub 2} removal efficiency and limestone utilization. This study revealed four different technologies that could be used to control chloride concentrations in closed-loop wet limestone FGD systems: reverse osmosis, electrodialysis reversal, vapor compression evaporation, and duct injection. This two-volume report describes each option in detail, discusses the basis for selecting the chloride threshold levels along with approximate cost estimates for combined chloride removal and waste disposal options, and presents flow sheets and detailed material balances for the least-cost combined options. The total annualized costs for chloride removal and waste disposal estimated in this study for a 300-MW plant range from 0.8 to 1.3 mils/kWh for controlling chloride at 3000 ppm to prevent corrosion and range from 0.3 to 0.7 mils/kWh for controlling chloride at 15,000 ppm to prevent decreased SO{sub 2} removal. The design coal has a relatively high chloride-to-sulfur ratio; costs for other coals would be lower.

  15. Electrolytic conditioning of a magnesium aluminum chloride complex for reversible magnesium deposition

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

    Barile, Christopher J.; Barile, Elizabeth C.; Zavadil, Kevin R.; Nuzzo, Ralph G.; Gewirth, Andrew A.

    2014-12-04

    We describe in this report the electrochemistry of Mg deposition and dissolution from the magnesium aluminum chloride complex (MACC). The results define the requirements for reversible Mg deposition and definitively establish that voltammetric cycling of the electrolyte significantly alters its composition and performance. Elemental analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy (SEM-EDS) results demonstrate that irreversible Mg and Al deposits form during early cycles. Electrospray ionization-mass spectrometry (ESI-MS) data show that inhibitory oligomers develop in THF-based solutions. These oligomers form via the well-established mechanism of a cationic ring-opening polymerization of THF during the initial synthesis of the MACC andmore » under resting conditions. In contrast, MACC solutions in 1,2-dimethoxyethane (DME), an acyclic solvent, do not evolve as dramatically at open circuit potential. Furthermore, we propose a mechanism describing how the conditioning process of the MACC in THF improves its performance by both tuning the Mg:Al stoichiometry and eliminating oligomers.« less

  16. Electrolytic conditioning of a magnesium aluminum chloride complex for reversible magnesium deposition

    SciTech Connect (OSTI)

    Barile, Christopher J.; Barile, Elizabeth C.; Zavadil, Kevin R.; Nuzzo, Ralph G.; Gewirth, Andrew A.

    2014-12-04

    We describe in this report the electrochemistry of Mg deposition and dissolution from the magnesium aluminum chloride complex (MACC). The results define the requirements for reversible Mg deposition and definitively establish that voltammetric cycling of the electrolyte significantly alters its composition and performance. Elemental analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy (SEM-EDS) results demonstrate that irreversible Mg and Al deposits form during early cycles. Electrospray ionization-mass spectrometry (ESI-MS) data show that inhibitory oligomers develop in THF-based solutions. These oligomers form via the well-established mechanism of a cationic ring-opening polymerization of THF during the initial synthesis of the MACC and under resting conditions. In contrast, MACC solutions in 1,2-dimethoxyethane (DME), an acyclic solvent, do not evolve as dramatically at open circuit potential. Furthermore, we propose a mechanism describing how the conditioning process of the MACC in THF improves its performance by both tuning the Mg:Al stoichiometry and eliminating oligomers.

  17. 3D mapping of water in oolithic limestone at atmospheric and vacuum saturation using X-ray micro-CT differential imaging

    SciTech Connect (OSTI)

    Boone, M.A.; De Kock, T.; Bultreys, T.; De Schutter, G.; Vontobel, P.; Van Hoorebeke, L.; Cnudde, V.

    2014-11-15

    Determining the distribution of fluids in porous sedimentary rocks is of great importance in many geological fields. However, this is not straightforward, especially in the case of complex sedimentary rocks like limestone, where a multidisciplinary approach is often needed to capture its broad, multimodal pore size distribution and complex pore geometries. This paper focuses on the porosity and fluid distribution in two varieties of Massangis limestone, a widely used natural building stone from the southeast part of the Paris basin (France). The Massangis limestone shows locally varying post-depositional alterations, resulting in different types of pore networks and very different water distributions within the limestone. Traditional techniques for characterizing the porosity and pore size distribution are compared with state-of-the-art neutron radiography and X-ray computed microtomography to visualize the distribution of water inside the limestone at different imbibition conditions. X-ray computed microtomography images have the great advantage to non-destructively visualize and analyze the pore space inside of a rock, but are often limited to the larger macropores in the rock due to resolution limitations. In this paper, differential imaging is successfully applied to the X-ray computed microtomography images to obtain sub-resolution information about fluid occupancy and to map the fluid distribution in three dimensions inside the scanned limestone samples. The detailed study of the pore space with differential imaging allows understanding the difference in the water uptake behavior of the limestone, a primary factor that affects the weathering of the rock. - Highlights: • The water distribution in a limestone was visualized in 3D with micro-CT. • Differential imaging allowed to map both macro and microporous zones in the rock. • The 3D study of the pore space clarified the difference in water uptake behavior. • Trapped air is visualized in the moldic

  18. Chemical conversion coating for protecting magnesium alloys from corrosion

    DOE Patents [OSTI]

    Bhargava, Gaurang; Allen, Fred M.; Skandan, Ganesh; Hornish, Peter; Jain, Mohit

    2016-01-05

    A chromate-free, self-healing conversion coating solution for magnesium alloy substrates, composed of 10-20 wt. % Mg(NO.sub.3).sub.2.6H.sub.2O, 1-5 wt. % Al(NO.sub.3).sub.3.9H.sub.2O, and less than 1 wt. % of [V.sub.10O.sub.28].sup.6- or VO.sub.3.sup.- dissolved in water. The corrosion resistance offered by the resulting coating is in several hundreds of hours in salt-spray testing. This prolonged corrosion protection is attributed to the creation of a unique structure and morphology of the conversion coating that serves as a barrier coating with self-healing properties. Hydroxoaluminates form the backbone of the barrier protection offered while the magnesium hydroxide domains facilitate the "slow release" of vanadium compounds as self-healing moieties to defect sites, thus providing active corrosion protection.

  19. Efficient One-Step Electrolytic Recycling of Low-Grade and Post-Consumer Magnesium Scrap

    SciTech Connect (OSTI)

    Adam C. Powell, IV

    2012-07-19

    Metal Oxygen Separation Technologies, Inc. (abbreviated MOxST, pronounced most) and Boston University (BU) have developed a new low-cost process for recycling post-consumer co-mingled and heavily-oxidized magnesium scrap, and discovered a new chemical mechanism for magnesium separations in the process. The new process, designated MagReGenTM, is very effective in laboratory experiments, and on scale-up promises to be the lowest-cost lowest-energy lowest-impact method for separating magnesium metal from aluminum while recovering oxidized magnesium. MagReGenTM uses as little as one-eighth as much energy as today's methods for recycling magnesium metal from comingled scrap. As such, this technology could play a vital role in recycling automotive non-ferrous metals, particularly as motor vehicle magnesium/aluminum ratios increase in order to reduce vehicle weight and increase efficiency.

  20. Low-Cost Magnesium Sheet Production using the Twin Roll Casting...

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

    More Documents & Publications Low-Cost Magnesium Sheet Production using the Twin Roll Casting Process and Asymmetric Rolling Materials Characterization Capabilities at the High ...

  1. Low-Cost Magnesium Sheet Production using the Twin Roll Casting...

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

    Magnesium Sheet Production using the Twin Roll Casting Process and Asymmetric Rolling Materials Characterization Capabilities at the High Temperature Materials Laboratory:...

  2. Elevated Temperature Tensile Tests on DU–10Mo Rolled Foils

    SciTech Connect (OSTI)

    Schulthess, Jason

    2014-09-01

    Tensile mechanical properties for uranium-10 wt.% molybdenum (U–10Mo) foils are required to support modeling and qualification of new monolithic fuel plate designs. It is expected that depleted uranium-10 wt% Mo (DU–10Mo) mechanical behavior is representative of the low enriched U–10Mo to be used in the actual fuel plates, therefore DU-10Mo was studied to simplify material processing, handling, and testing requirements. In this report, tensile testing of DU-10Mo fuel foils prepared using four different thermomechanical processing treatments were conducted to assess the impact of foil fabrication history on resultant tensile properties.

  3. Regional analysis of rhythmic bedding in the Fort Hays limestone member, Niobrara Formation (Upper Cretaceous), US western interior

    SciTech Connect (OSTI)

    Laferriere, A.P.

    1987-01-01

    Results of a regional stratigraphic investigation of the rhythmically bedded Fort Hays limestone member of Kansas, Colorado, and New Mexico indicate at least two levels of cyclicity. Regional development of these cycles strongly supports the hypothesis that they are climatic in origin. Departures from simple cyclical patterns resulted from sedimentary effects of Late Cretaceous orogenic activity, erosional events associated with eustatic sea level changes, diagenetic modification, and possibly from interference between orbital parameters having different periodicities. The vulnerability of Milankovitch-type cyclicity to overprinting by tectono-sedimentologic effects makes units such as the Fort Hays useful as indicators of subtle tectonic activity. Regional thickness changes in groups of shale-limestone couplets were identified, correlated, and mapped in the subsurface using geophysical well log information in order to locate subtle structural elements that influenced Fort Hays sedimentation. In the Denver-Julesburg Basin of Colorado and western Kansas, thinning of the section between Fort Hays marker horizons occurs dominantly along northeastwardly trending belts that resulted apparently from Late Cretaceous reactivation of the Transcontinental Arch. Isotopic and petrographic analyses were conducted on pelagic (carbonate matrix) and benthic (inoceramid bivalve) constituents of selected shale/limestone couplets. These data suggest that there was little difference in temperature or salinity between times of terrigenous detrital input and times of nearly pure carbonate deposition. Isotopic information from matrix samples suggests a westward decrease in salinity of surface water in the Western Interior Sea. Isotopic data from largely unaltered inoceramid bivalves indicate bottom-water conditions of near-normal marine salinity.

  4. Hydrothermal dolomitization of Jurassic-Cretaceous limestones in the southern Alps (Italy): Relation to tectonics and volcanism

    SciTech Connect (OSTI)

    Cervato, C. )

    1990-05-01

    Dolomitization has affected up to 750m of the Jurassic and Cretaceous pelagic carbonate sequence of the southern continental margin of the Alpine Tethys; the sequence crops out in the southern Alps of Italy (Monti Lessini). Late Paleocene to Miocene extrusion of basaltic tuffs, breccias, and lavas was contemporaneous with the dolomitization was was associated with extensive tectonism in an ancient back-arc basin. More than 200 samples were analyzed by X-ray diffraction, cathodoluminescence, scanning electron microscopy, stable isotope ratios (carbon, oxygen, strontium), and clay mineralogy. The dolomite contains 40% to 50% MgCO{sub 3}. In thin sections, the crystal size distribution is unimodal (about 100 {mu}m), possibly indicating a single nucleation for the main crystallization phase. The {delta}{sup 13}C of the dolomite is not appreciably different from the undolomitized pelagic limestone (+1.0{per thousand} to +2.0{per thousand} Peedee belemnite (PDB)). The {delta}{sup 18}O variation (-5.0{per thousand} to -13.0{per thousand} PDB) is due to temperature variation in the system. The {sup 87}Sr/{sup 86}Sr ratio in the dolomite (0.70839-0.70867) is consistent with the ratio in late Oligocene-Miocene marine water. Clay minerals in limestone and dolomite differ in the presence of neoformed Mg-chlorite, indicating a maximum temperature of about 150C for dolomitization. The dolomite is suggested to have a hydrothermal origin. The heat flow associated with the volcanism allowed marine water to penetrate the system and circulate in convective cells through the tectonic breccias, locally dolomitizing the limestone.

  5. Oxidation, Reduction, and Condensation of Alcohols over (MO3)3 (M=Mo, W) Nanoclusters

    SciTech Connect (OSTI)

    Fang, Zongtang; Li, Zhenjun; Kelley, Matthew S.; Kay, Bruce D.; Li, Shenggang; Hennigan, Jamie M.; Rousseau, Roger J.; Dohnalek, Zdenek; Dixon, David A.

    2014-10-02

    The reactions of deuterated methanol, ethanol, 1-propanol, 1-butanol, 2-propanol, 2-butanol and t-butanol over cyclic (MO3)3 (M = Mo, W) clusters were studied experimentally with temperature programmed desorption (TPD) and theoretically with coupled cluster CCSD(T) theory and density functional theory. The reactions of two alcohols per M3O9 cluster are required to provide agreement with experiment for D2O release, dehydrogenation and dehydration. The reaction begins with the elimination of water by proton transfers and forms an intermediate dialkoxy species which can undergo further reaction. Dehydration proceeds by a ? hydrogen transfer to a terminal M=O. Dehydrogenation takes place via an ? hydrogen transfer to an adjacent MoVI = O atom or a WVI metal center with redox involved for M = Mo and no redox for M = W. The two channels have comparable activation energies. H/D exchange to produce alcohols can take place after olefin is released or via the dialkoxy species depending on the alcohol and the cluster. The Lewis acidity of the metal center with WVI being larger than MoVI results in the increased reactivity of W3O9 over Mo3O9 for dehydrogenation and dehydration.

  6. Elastic modulus of phases in Ti–Mo alloys

    SciTech Connect (OSTI)

    Zhang, Wei-dong; Liu, Yong; Wu, Hong; Song, Min; Zhang, Tuo-yang; Lan, Xiao-dong; Yao, Tian-hang

    2015-08-15

    In this work, a series of binary Ti–Mo alloys with the Mo contents ranging from 3.2 to 12 at.% were prepared using non-consumable arc melting. The microstructures were investigated by X-ray diffraction and transmission electron microscope, and the elastic modulus was evaluated by nanoindentation testing technique. The evolution of the volume fractions of ω phase was investigated using X-ray photoelectron spectroscopy. The results indicated that the phase constitution and elastic modulus of the Ti–Mo alloys are sensitive to the Mo content. Ti–3.2Mo and Ti–8Mo alloys containing only α and β phases, respectively, have a low elastic modulus. In contrast, Ti–4.5Mo, Ti–6Mo, Ti–7Mo alloys, with different contents of ω phase, have a high elastic modulus. A simple micromechanical model was used to calculate the elastic modulus of ω phase (E{sub ω}), which was determined to be 174.354 GPa. - Highlights: • Ti–Mo alloys with the Mo contents ranging from 3.2 to 12 at.% were investigated. • XPS was used to investigate the volume fractions of ω phase. • The elastic modulus of Ti–Mo alloys is sensitive to the Mo content. • The elastic modulus of ω phase was determined to be 174.354 GPa.

  7. Accelerator Production Options for 99MO

    SciTech Connect (OSTI)

    Bertsche, Kirk; /SLAC

    2010-08-25

    Shortages of {sup 99}Mo, the most commonly used diagnostic medical isotope, have caused great concern and have prompted numerous suggestions for alternate production methods. A wide variety of accelerator-based approaches have been suggested. In this paper we survey and compare the various accelerator-based approaches.

  8. Advanced Hybrid Batteries with a Magnesium Metal Anode and Spinel

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

    LiMn₂O₄ Cathode - Joint Center for Energy Storage Research July 11, 2016, Research Highlights Advanced Hybrid Batteries with a Magnesium Metal Anode and Spinel LiMn₂O₄ Cathode Two Mg-Li dual salt hybrid electrolytes were successfully developed and can enable rechargeable Mg-LiMn2O4 batteries Scientific Achievement Two Mg-Li dual salt hybrid electrolytes were developed with excellent oxidative stability up to around 3.8 V (vs Mg/Mg2+) on a aluminum current collector, enabling the

  9. Electrochemistry of Magnesium Electrolytes in Ionic Liquids for Secondary

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

    Batteries - Joint Center for Energy Storage Research 23, 2014, Research Highlights Electrochemistry of Magnesium Electrolytes in Ionic Liquids for Secondary Batteries Cyclic voltammograms of neat DEME-BF4 (light gray) and 100 mM Mg(BH4)2 in DEME-BF4 (black). CV scan limits are chosen to represent the electrochemical stability window. Inset: magnified view with voltage range restricted to -1.5 to 1.5 V vs. Mg/Mg2+. Scientific Achievement Ionic liquids (ILs) have wide electrochemical stability

  10. High Performance Batteries Based on Hybrid Magnesium and Lithium Chemistry

    SciTech Connect (OSTI)

    Cheng, Yingwen; Shao, Yuyan; Zhang, Jiguang; Sprenkle, Vincent L.; Liu, Jun; Li, Guosheng

    2014-01-01

    Magnesium and lithium (Mg/Li) hybrid batteries that combine Mg and Li electrochemistry, consisting of a Mg anode, a lithium-intercalation cathode and a dual-salt electrolyte with both Mg2+ and Li+ ions, were constructed and examined in this work. Our results show that hybrid (Mg/Li) batteries were able to combine the advantages of Li-ion and Mg batteries, and delivered outstanding rate performance (83% for capacities at 15C and 0.1C) and superior cyclic stability (~5% fade after 3000 cycles).

  11. Copper-silicon-magnesium alloys for latent heat storage

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

    Gibbs, P. J.; Withey, E. A.; Coker, E. N.; Kruizenga, A. M.; Andraka, C. E.

    2016-06-21

    The systematic development of microstructure, solidification characteristics, and heat of solidification with composition in copper-silicon-magnesium alloys for thermal energy storage is presented. Differential scanning calorimetry was used to relate the thermal characteristics to microstructural development in the investigated alloys and clarifies the location of one of the terminal three-phase eutectics. Repeated thermal cycling highlights the thermal storage stability of the transformation through multiple melting events. In conclusion, two near-terminal eutectic alloys display high enthalpies of solidification, relatively narrow melting ranges, and stable transformation hysteresis behaviors suited to thermal energy storage.

  12. Novel, electrolyte solutions comprising fully inorganic salts with high anodic stability for rechargeable magnesium batteries

    SciTech Connect (OSTI)

    Doe, RE; Han, R; Hwang, J; Gmitter, AJ; Shterenberg, I; Yoo, HD; Pour, N; Aurbach, D

    2014-01-01

    Herein the first inorganic magnesium salt solution capable of highly reversible magnesium electrodeposition is presented. Synthesized by acid-base reaction of MgCl2 and Lewis acidic compounds such as AlCl3, this salt class demonstrates upwards of 99% Coulombic efficiency, deposition overpotential of <200 mV, and anodic stability of 3.1 V.

  13. Intermetallic phase formation and breakdown of Mo diffusion barriers in Ni-Mo-Cu and Ni-Mo-Monel 400 diffusion triads

    SciTech Connect (OSTI)

    Shueh, Y.

    1988-01-01

    The purpose of this research was to study the kinetics of compound formation and the interdiffusion behavior of a sacrificial type diffusion barrier in a model system. Ni-Mo diffusion couples were annealed in an inert atmosphere at 950-1050{degree}C for 5-300 hours. Ni-Mo-Cu and Ni-Mo-Monel 400 diffusion triads with varied thicknesses of Mo layers sandwiched by Ni and C or Monel 400 disks were annealed under the same conditions. Parabolic growth of the intermetallic phase, {beta}, was observed at 1000{degree}C and 1050{degree}C in the semi-infinite Ni-Mo diffusion couple an din the Ni-Mo-Cu diffusion triad when a finite thickness of the Mo layer remained. The {beta} phase exhibited more or less planar morphology except in the case of some extremely rugged interfaces which were associated with grain boundaries adjacent to these interfaces. Dissociation and recession of the compound layer in Ni-Mo-Cu diffusion triads initiated when the Mo layer was nearly consumed. The product phases of the dissociation reaction are consistent with those predicted from the Ni-Mo-Cu ternary phase diagram. Numerical methods based on a finite difference technique, and an analytical solution based on diffusion controlled parabolic growth and quasi-steady-state approximation in the {beta} phase region were used to analyze the results.

  14. Carbon dioxide adsorbents containing magnesium oxide suitable for use at high temperatures

    DOE Patents [OSTI]

    Mayorga, Steven Gerard; Weigel, Scott Jeffrey; Gaffney, Thomas Richard; Brzozowski, Jeffrey Richard

    2001-01-01

    Adsorption of carbon dioxide from gas streams at temperatures in the range of 300 to 500.degree. C. is carried out with a solid adsorbent containing magnesium oxide, preferably promoted with an alkali metal carbonate or bicarbonate so that the atomic ratio of alkali metal to magnesium is in the range of 0.006 to 2.60. Preferred adsorbents are made from the precipitate formed on addition of alkali metal and carbonate ions to an aqueous solution of a magnesium salt. Atomic ratios of alkali metal to magnesium can be adjusted by washing the precipitate with water. Low surface area adsorbents can be made by dehydration and CO.sub.2 removal of magnesium hydroxycarbonate, with or without alkali metal promotion. The process is especially valuable in pressure swing adsorption operations.

  15. Pilot-scale Limestone Emission Control (LEC) process: A development project. Volume 1, Main report and appendices A, B, C, and D: Final report

    SciTech Connect (OSTI)

    Prudich, M.E.; Appell, K.W.; McKenna, J.D.

    1994-03-01

    ETS, Inc., a pollution consulting firm with headquarters in Roanoke, Virginia, has developed a dry, limestone-based flue gas desulfurization (FGD) system. This SO{sub 2} removal system, called Limestone Emission Control (LEC), can be designed for installation on either new or existing coal-fired boilers. In the LEC process, the SO{sub 2} in the flue gas reacts with wetted granular limestone that is contained in a moving bed. A surface layer of principally calcium sulfate (CaSO{sub 4}) is formed on the limestone. Periodic removal of this surface layer by mechanical agitation allows high utilization of the limestone granules. A nominal 5,000 acfm LEC pilot plant has been designed, fabricated and installed on the slipstream of a 70,000 pph stoker boiler providing steam to Ohio University`s Athens, Ohio campus. A total of over 90 experimental trials have been performed using the pilot-scale moving-bed LEC dry scrubber as a part of this research project with run times ranging up to a high of 125 hours. SO{sub 2} removal efficiencies as high as 99.9% were achievable for all experimental conditions studied during which sufficient humidification was added to the LEC bed. The LEC process and conventional limestone scrubbing have been compared on an equatable basis using flue gas conditions that would be expected at the outlet of the electrostatic precipitator (ESP) of a 500 MW coal-fired power plant. The LEC was found to have a definite economic advantage in both direct capital costs and operating costs. Based on the success and findings of the present project, the next step in LEC process development will be a full-scale commercial demonstration unit.

  16. Role of SrMoO{sub 4} in Sr{sub 2}MgMoO{sub 6} synthesis

    SciTech Connect (OSTI)

    Vasala, S.; Yamauchi, H.; Karppinen, M.

    2011-05-15

    Here we investigate the elemental and phase compositions during the solid-state synthesis of the promising SOFC-anode material, Sr{sub 2}MgMoO{sub 6}, and demonstrate that molybdenum does not notably evaporate under the normal synthesis conditions with temperatures up to 1200 {sup o}C due to the formation of SrMoO{sub 4} as an intermediate product at low temperatures, below 600 {sup o}C. However, partial decomposition of the Sr{sub 2}MgMoO{sub 6} phase becomes evident at the higher temperatures ({approx}1500 {sup o}C). The effect of SrMoO{sub 4} on the electrical conductivity of Sr{sub 2}MgMoO{sub 6} is evaluated by preparing a series of Sr{sub 2}MgMoO{sub 6} samples with different amounts of additional SrMoO{sub 4}. Under the reducing operation conditions of an SOFC anode the insulating SrMoO{sub 4} phase is apparently reduced to the highly conductive SrMoO{sub 3} phase. Percolation takes place with 20-30 wt% of SrMoO{sub 4} in a Sr{sub 2}MgMoO{sub 6} matrix, with a notable increase in electrical conductivity after reduction. Conductivity values of 14, 60 and 160 S/cm are determined at 800 {sup o}C in 5% H{sub 2}/Ar for the Sr{sub 2}MgMoO{sub 6} samples with 30, 40 and 50 wt% of added SrMoO{sub 4}, respectively. -- Graphical abstract: SrMoO{sub 4} is formed at low temperatures during the synthesis of Sr{sub 2}MgMoO{sub 6}, which prevents the volatilization of Mo from typical precursor mixtures of this promising SOFC anode material. SrMoO{sub 4} is insulating and it is often found as an impurity in Sr{sub 2}MgMoO{sub 6} samples. It is however readily reduced to highly conducting SrMoO{sub 3}. Composites of Sr{sub 2}MgMoO{sub 6} and SrMoO{sub 3} show increased electrical conductivities compared to pure Sr{sub 2}MgMoO{sub 6} under the reductive operation conditions of an SOFC anode. Display Omitted Highlights: {yields} Sr{sub 2}MgMoO{sub 6} is a promising SOFC anode material. {yields} During the Sr{sub 2}MgMoO{sub 6} synthesis SrMoO{sub 4} is formed at low

  17. Mo-99 | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Mo-99 DOE/NNSA Successfully Establishes Uranium Lease and Takeback Program to Support Critical Medical Isotope Production In January 2016, the U.S. Department of Energy's National Nuclear Security Administration (DOE/NNSA) successfully established the Uranium Lease and Take-Back (ULTB) program, as directed in the American Medical Isotopes Production Act of 2012, to support the commercial production of the medical... NNSA's work aids in fight against cancer World Cancer Day encourages citizens

  18. Effect of pore pressure on the elastic moduli, porosity and permeability of Berea sandstone and Leuders limestone

    SciTech Connect (OSTI)

    Thompson, T.W.; Kelkar, S.M.; Gray, K.E.

    1983-02-01

    The behavior of Berea sandstone and Leuders limestone under atmospheric and elevated pore pressures is reported. The porosity and the permeability changes, along with the static and dynamic moduli for these rocks have been determined under various conditions. The existing theoretical background pertinent to the study is reviewed along with the previous experimental work. The detailed descriptions and the discussions on the experimental procedure involved and the equipment utilized are presented. A discussion on the sources of experimental errors is included. It also includes the error propagation equations and relevant discussions on the data acquisition and analysis. The findings are summarized together with a discussion of the results. The conclusions drawn from these results are included. The bulk of the data acquired and the results computed from it are presented.

  19. System for removing solids from a used lime or limestone slurry scrubbing liquor in flue gas desulfurization

    SciTech Connect (OSTI)

    Randolph, A.D.

    1981-10-13

    The flue gas desulfurization process using a lime or limestone slurry scrubbing solution produces used liquor containing calcium sulfite or sulfate (Typically gypsum). Precipitated particles are removed by feeding the used scrubbing liquor to an agitated crystallization zone to grow crystals and directing part of the used scrubbing liquor from that zone to a quiescent crystallization zone, in which particles are settled back into the agitated zone. An underflow stream from the agitated zone containing large crystals is combined with an overflow stream from the quiescent zone, which combined stream is clarified with the fines being returned to the scrubber and the large crystals being removed as a waste product. Apparatus for performing the above process in which the agitated and quiescent crystallization zones form part of a single crystallization vessel, and the two zones are separated by a baffle.

  20. Retrofit costs for lime/limestone FGD and lime spray drying at coal-fired utility boilers

    SciTech Connect (OSTI)

    Emmel, T.E.; Jones, J.W.

    1990-01-01

    The paper gives results of a research program the objective of which was to significantly improve engineering cost estimates currently being used to evaluate the economic effects of applying SO2 controls to existing coal-fired utility boilers. The costs of retrofitting conventional lime/limestone wet flue gas desulfurization (L/LS FGD) and lime spray drying (LSD) FGD at 100-200 coal-fired power plants are being estimated under this program. The retrofit capital cost estimating procedures used for L/LS FGD and LSD FGD make two cost adjustments to current procedures used to estimate FGD costs: cost adders (for items not normally included in FGD system costs; e.g., demolition and relocation of existing facilities) and cost multipliers (to adjust capital costs for site access, congestion, and underground obstructions).

  1. DOE - Office of Legacy Management -- St Louis Downtown Site - MO 02

    Office of Legacy Management (LM)

    Downtown Site - MO 02 FUSRAP Considered Sites St. Louis Downtown, MO Alternate Name(s): Destrehan Street Plant Downtown Site Mallinckrodt Chemical Plant Mallinckrodt Chemical Works MO.02-1 MO.02-3 Location: 65 Destrehan Street, St. Louis, Missouri MO.02-5 Historical Operations: Conducted uranium metal and uranium oxides research, development, and production for MED and AEC. MO.02-6 MO.02-7 Eligibility Determination: Eligible MO.02-1 Radiological Survey(s): Assessment Surveys MO.02-2 MO.02-3 Site

  2. Synthesis and optical study of barium magnesium aluminate blue phosphors

    SciTech Connect (OSTI)

    Jeet, Suninder Pandey, O. P.; Sharma, Manoj

    2015-05-15

    Europium doped barium magnesium aluminate (BaMgAl{sub 10}O{sub 17}:Eu{sup 2+}) phosphor was prepared via solution combustion method at 550C using urea as a fuel. Morphological and optical properties of the prepared sample was studied by X-ray diffraction (XRD), Transmission electron microscopy (TEM) and Photoluminescence spectroscopy (PL). XRD result showed the formation of pure phase BaMgAl{sub 10}O{sub 17}(JCPDS 26-0163) along with an additional phase BaAl{sub 2}O{sub 4}(JCPDS 01-082-1350). TEM image indicated the formation of faceted particles with average particle size 40?nm. From PL spectra, a broad emission band obtained at about 450?nm attributes to 4f{sup 6} 5d ? 4f{sup 7} transition of Eu{sup 2+} which lies in the blue region of the visible spectrum.

  3. Appendix MgO: Magnesium Oxide as an Engineered Barrier

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

    MgO-2014 Magnesium Oxide as an Engineered Barrier United States Department of Energy Waste Isolation Pilot Plant Carlsbad Field Office Carlsbad, New Mexico Compliance Recertification Application 2014 Appendix MgO-2014 Table of Contents MgO-1.0 Introduction MgO-2.0 Description of the Engineered Barrier System MgO-2.1 Emplacement of MgO MgO-2.1.1 Supersacks MgO-2.1.2 Minisacks MgO-2.1.3 Use of Racks to Emplace Additional MgO MgO-2.1.4 Changes since the CRA-2009 MgO-2.2 MgO Vendors MgO-3.0

  4. Pilot-scale limestone emission control (LEC) process: A development project. Volume 1: Main report and appendices A, B, C, and D. Final report

    SciTech Connect (OSTI)

    Not Available

    1994-03-01

    ETS, Inc., a pollution consulting firm with headquarters in Roanoke, Virginia, has developed a dry, limestone-based flue gas desulfurization (FGD) system. This SO{sub 2} removal system, called Limestone Emission Control (LEC), can be designed for installation on either new or existing coal-fired boilers. In the LEC process, the SO{sub 2} in the flue gas reacts with wetted granular limestone that is contained in a moving bed. A surface layer of principally calcium sulfate (CaSO{sub 4}) is formed on the limestone. Periodic removal of this surface layer by mechanical agitation allows high utilization of the limestone granules. The primary goal of the current study is the demonstration of the techno/economic capability of the LEC system as a post-combustion FGD process capable of use in both existing and future coal-fired boiler facilities burning high-sulfur coal. A nominal 5,000 acfm LEC pilot plant has been designed, fabricated and installed on the slipstream of a 70,000 pph stoker boiler providing steam to Ohio University`s Athens, Ohio campus. The pilot plant was normally operated on the slipstream of the Ohio Univ. boiler plant flue gas, but also had the capability of operating at higher inlet SO{sub 2} concentrations (typically equivalent to 3-1/2% sulfur coal) than those normally available from the flue gas slipstream. This was accomplished by injecting SO{sub 2} gas into the slipstream inlet. The pilot plant was instrumented to provide around-the-clock operation and was fully outfitted with temperature, SO{sub 2}, gas flow and pressure drop monitors.

  5. Vehicle Technologies Office Merit Review 2015: Magnesium-Intensive Front End Sub-Structure Development

    Broader source: Energy.gov [DOE]

    Presentation given by USAMP at 2015 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about magnesium-intensive front end sub...

  6. NNSA Awards Mo-99 Cooperative Agreement to General Atomics | National

    National Nuclear Security Administration (NNSA)

    Nuclear Security Administration | (NNSA) Awards Mo-99 Cooperative Agreement to General Atomics September 30, 2015 WASHINGTON, DC - Today, the Department of Energy's National Nuclear Security Administration (DOE/NNSA) announced that it will award a cooperative agreement to General Atomics (GA) to support its project for domestic production of molybdenum-99 (Mo-99) without highly enriched uranium (HEU). Mo-99 is the parent isotope of technetium-99m, which is the most widely used radioisotope

  7. Novel Nonflammable Electrolytes for Secondary Magnesium Batteries and High Voltage Electrolytes for Electrochemcial Supercapacitors

    SciTech Connect (OSTI)

    Dr. Brian Dixon

    2008-12-30

    Magnesium has been used successfully in primary batteries, but its use in rechargeable cells has been stymied by the lack of suitable non-aqueous electrolyte that can conduct Mg+2 species, combined with poor stripping and plating properties. The development of a suitable cathode material for rechargeable magnesium batteries has also been a roadblock, but a nonflammable electrolyte is key. Likewise, the development of safe high voltage electrochemical supercapaitors has been stymied by the use of flammable solvents in the liquid electrolyte; to wit, acetonitrile. The purpose of the research conducted in this effort was to identify useful compositions of magnesium salts and polyphosphate solvents that would enable magnesium ions to be cycled within a secondary battery design. The polyphosphate solvents would provide the solvent for the magnesium salts while preventing the electrolyte from being flammable. This would enable these novel electrolytes to be considered as an alternative to THF-based electrolytes. In addition, we explored several of these solvents together with lithium slats for use as high voltage electrolytes for carbon-based electrochemical supercapacitors. The research was successful in that: 1) Magnesium imide dissolved in a phosphate ester solvent that contains a halogented phosphate ester appears to be the preferred electrolyte for a rechargeable Mg cell. 2) A combination of B-doped CNTs and vanadium phosphate appear to be the cathode of choice for a rechargeable Mg cell by virtue of higher voltage and better reversibility. 3) Magnesium alloys appear to perform better than pure magnesium when used in combination with the novel polyphosphate electrolytes. Also, this effort has established that Phoenix Innovation??s family of phosphonate/phosphate electrolytes together with specific lithium slats can be used in supercapacitor systems at voltages of greater than 10V.

  8. MoRu/Be multilayers for extreme ultraviolet applications

    DOE Patents [OSTI]

    Bajt, Sasa C.; Wall, Mark A.

    2001-01-01

    High reflectance, low intrinsic roughness and low stress multilayer systems for extreme ultraviolet (EUV) lithography comprise amorphous layers MoRu and crystalline Be layers. Reflectance greater than 70% has been demonstrated for MoRu/Be multilayers with 50 bilayer pairs. Optical throughput of MoRu/Be multilayers can be 30-40% higher than that of Mo/Be multilayer coatings. The throughput can be improved using a diffusion barrier to make sharper interfaces. A capping layer on the top surface of the multilayer improves the long-term reflectance and EUV radiation stability of the multilayer by forming a very thin native oxide that is water resistant.

  9. Demonstration of LED Street Lighting in Kansas City, MO Kinzey...

    Office of Scientific and Technical Information (OSTI)

    Street Lighting in Kansas City, MO Kinzey, Bruce R.; Royer, Michael P.; Hadjian, M.; Kauffman, Rick LED streetlighting; field illuminance measurement LED streetlighting; field...

  10. Predicting sigma formation in mo-bearing stainless steels. (Conference...

    Office of Scientific and Technical Information (OSTI)

    Title: Predicting sigma formation in mo-bearing stainless steels. No abstract prepared. Authors: Perricone, Matthew ; Dupont, John Neuman ; Anderson, T. D. 1 ; Robino, Charles ...

  11. DOE - Office of Legacy Management -- Rogers Iron Works Co - MO 10

    Office of Legacy Management (LM)

    Rogers Iron Works Co - MO 10 FUSRAP Considered Sites Site: ROGERS IRON WORKS CO. (MO.10 ) Elimination from consideration under FUSRAP Designated Name: Not Designated Alternate Name: Rogers Iron Co. MO.10-1 Location: Joplin , Missouri MO.10-1 Evaluation Year: 1990 MO.10-2 MO.10-3 Site Operations: Tested C-liner crushing methods. MO.10-1 Site Disposition: Eliminated - Potential for contamination considered remote based on limited quantities of material handled MO.10-3 MO.10-4 Radioactive Materials

  12. Structure and electronic properties of Cu nanoclusters supported on Mo2C(001) and MoC(001) surfaces

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

    Posada-Pérez, Sergio; Viñes, Francesc; Rodríguez, José A.; Illas, Francesc

    2015-09-15

    In this study, the atomic structure and electronic properties of Cun nanoclusters (n = 4, 6, 7, and 10) supported on cubic nonpolar δ-MoC(001) and orthorhombic C- or Mo-terminated polar β-Mo2C(001) surfaces have been investigated by means of periodic density functional theory based calculations. The electronic properties have been analyzed by means of the density of states, Bader charges, and electron localization function plots. The Cu nanoparticles supported on β-Mo2C(001), either Mo- or C-terminated, tend to present a two-dimensional structure whereas a three-dimensional geometry is preferred when supported on δ-MoC(001), indicating that the Mo:C ratio and the surface polarity playmore » a key role determining the structure of supported clusters. Nevertheless, calculations also reveal important differences between the C- and Mo-terminated β-Mo2C(001) supports to the point that supported Cu particles exhibit different charge states, which opens a way to control the reactivity of these potential catalysts.« less

  13. Recovery and utilization of gypsum and limestone from scrubber sludge. Final technical report, September 1, 1992--August 31, 1993

    SciTech Connect (OSTI)

    Kawatra, S.K.; Eisele, T.C.

    1993-12-31

    Wet flue-gas desulfurization units in coal-fired power plants produce a large amount of sludge which must be disposed of, and which is currently landfilled in most cases. Increasing landfill costs are gradually forcing utilities to find other alternatives. In principle, this sludge can be used to make gypsum (CaSO{sub 4}{center_dot}2H{sub 2}O) for products such as plaster-of-Paris and wallboard, but only if impurities such as unreacted limestone and soluble salts are removed, and the calcium sulfite (CaSO{sub 3}) is oxidized to calcium sulfate (CaSO{sub 4}). This project investigated methods for removing the impurities from the sludge so that high-quality, salable gypsum products can be made. Two processes were studied, both separately and in combination: Water-only cycloning, and froth flotation. A large fraction (30--40%) of the impurities in the sludge are contained in the coarser, higher-density particles, which are readily removed using a water-only cyclone. Much of the remaining impurities are hydrophobic, and can be removed by froth flotation. A combined cyclone/froth flotation process has been found to be suitable for producing a high-purity product from scrubber sludge at low cost.

  14. MOED_of_the_Italian_Republic.PDF | Department of Energy

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

    MOED_of_the_Italian_Republic.PDF MOED_of_the_Italian_Republic.PDF (209.56 KB) More Documents & Publications Scanned_Agreement.pdf International_Agreements_January_2001_December_2004.pdf Implementing Arrangement Between DOE and METI on R&D Cooperation on Clean Energy Technology - April 2015

  15. Oxide Film and Porosity Defects in Magnesium Alloy AZ91

    SciTech Connect (OSTI)

    Wang, Liang [Mississippi State University (MSU); Rhee, Hongjoo [Mississippi State University (MSU); Felicelli, Sergio D. [Mississippi State University (MSU); Sabau, Adrian S [ORNL; Berry, John T. [Mississippi State University (MSU)

    2009-01-01

    Porosity is a major concern in the production of light metal parts. This work aims to identify some of the mechanisms of microporosity formation in magnesium alloy AZ91. Microstructure analysis was performed on several samples obtained from gravity-poured ingots in graphite plate molds. Temperature data during cooling was acquired with type K thermocouples at 60 Hz at three locations of each casting. The microstructure of samples extracted from the regions of measured temperature was then characterized with optical metallography. Tensile tests and conventional four point bend tests were also conducted on specimens cut from the cast plates. Scanning electron microscopy was then used to observe the microstructure on the fracture surface of the specimens. The results of this study revealed the existence of abundant oxide film defects, similar to those observed in aluminum alloys. Remnants of oxide films were detected on some pore surfaces, and folded oxides were observed in fracture surfaces indicating the presence of double oxides entrained during pouring.

  16. Durability of concrete materials in high-magnesium brine

    SciTech Connect (OSTI)

    Wakeley, L.D.; Poole, T.S.; Burkes, J.P.

    1994-03-01

    Cement pastes and mortars representing 11 combinations of candidate concrete materials were cast in the laboratory and monitored for susceptibility to chemical deterioration in high-magnesium brine. Mixtures were selected to include materials included in the current leading candidate concrete for seals at the Waste Isolation Pilot Plant (WIPP). Some materials were included in the experimental matrix to answer questions that had arisen during study of the concrete used for construction of the liner of the WIPP waste-handling shaft. Mixture combinations compared Class C and Class F fly ashes, presence or absence of an expansive component, and presence or absence of salt as a mixture component. Experimental conditions exposed the pastes and mortars to extreme conditions, those being very high levels of Mg ion and an effectively unlimited supply of brine. All pastes and mortars showed deterioration with brine exposure. In general, mortars deteriorated more extensively than the corresponding pastes. Two-inch cube specimens of mortar were not uniformly deteriorated, but showed obvious zoning even after a year in the brine, with a relatively unreacted zone remaining at the center of each cube. Loss of calcium from the calcium hydroxide of paste/aggregate interfaces caused measurable strength loss in the reacted zone comprising the outer portion of every mortar specimen. The current candidate mass concrete for WIPP seals includes salt as an initial component, and has a relatively closed initial microstructure. Both of these features contribute to its suitability for use in large placements within the Salado Formation.

  17. Ab Initio Thermodynamic Model for Magnesium Carbonates and Hydrates

    SciTech Connect (OSTI)

    Chaka, Anne M.; Felmy, Andrew R.

    2014-03-28

    An ab initio thermodynamic framework for predicting properties of hydrated magnesium carbonate minerals has been developed using density-functional theory linked to macroscopic thermodynamics through the experimental chemical potentials for MgO, water, and CO2. Including semiempirical dispersion via the Grimme method and small corrections to the generalized gradient approximation of Perdew, Burke, and Ernzerhof for the heat of formation yields a model with quantitative agreement for the benchmark minerals brucite, magnesite, nesquehonite, and hydromagnesite. The model shows how small differences in experimental conditions determine whether nesquehonite, hydromagnesite, or magnesite is the result of laboratory synthesis from carbonation of brucite, and what transformations are expected to occur on geological time scales. Because of the reliance on parameter-free first principles methods, the model is reliably extensible to experimental conditions not readily accessible to experiment and to any mineral composition for which the structure is known or can be hypothesized, including structures containing defects, substitutions, or transitional structures during solid state transformations induced by temperature changes or processes such as water, CO2, or O2 diffusion. Demonstrated applications of the ab initio thermodynamic framework include an independent means to evaluate differences in thermodynamic data for lansfordite, predicting the properties of Mg analogs of Ca-based hydrated carbonates monohydrocalcite and ikaite which have not been observed in nature, and an estimation of the thermodynamics of barringtonite from the stoichiometry and a single experimental observation.

  18. Fragile structural transition in Mo3Sb7

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

    Yan, Jiaqiang -Q.; McGuire, Michael A; May, Andrew F; Parker, David S.; Mandrus, D. G.; Sales, Brian C.

    2015-01-01

    Mo3Sb7 single crystals lightly doped with Cr, Ru, or Te are studied in order to explore the interplay between superconductivity, magnetism, and the cubic-tetragonal structural transition. The structural transition at 53 K is extremely sensitive to Ru or Te substitution which introduces additional electrons, but robust against Cr substitution. We observed no sign of a structural transition in superconducting Mo2.91Ru0.09Sb7 and Mo3Sb6.975Te0.025. In contrast, 3 at.% Cr doping only slightly suppresses the structural transition to 48 K while leaving no trace of superconductivity above 1.8 K. Analysis of magnetic properties suggests that the interdimer interaction in Mo3Sb7 is near amore » critical value and essential for the structural transition. Futhermore, all dopants suppress the superconductivity of Mo3Sb7. The tetragonal structure is not necessary for superconductivity.« less

  19. Irradiation induced structural change in Mo2Zr intermetallic phase

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

    Gan, J.; Keiser, Jr., D. D.; Miller, B. D.; Eriksson, N.; Sohn, Y. H.; Kirk, M.

    2016-05-14

    The Mo2Zr phase has been identified as a major interaction product at the interface of U-10Mo and Zr. Transmission electron microscopy in-situ irradiation with Kr ions at 200 °C with doses up to 2.0E + 16 ions/cm2 was carried out to investigate the radiation stability of the Mo2Zr. The Mo2Zr undergoes a radiation-induced structural change, from a large cubic (cF24) to a small cubic (cI2), along with an estimated 11.2% volume contraction without changing its composition. The structural change begins at irradiation dose below 1.0E + 14 ions/cm2. Furthermore, the transformed Mo2Zr phase demonstrates exceptional radiation tolerance with the developmentmore » of dislocations without bubble formation.« less

  20. Neutrino scattering off the stable even-even Mo isotopes

    SciTech Connect (OSTI)

    Balasi, K. G.; Kosmas, T. S.; Divari, P. C. [Theoretical Physics Section, University of Ioannina, GR 45110 Ioannina (Greece)

    2009-11-09

    Inelastic neutrino-nucleus reaction cross sections are studied focusing on the neutral current processes. Particularly, we investigate the angular and initial neutrino-energy dependence of the differential and integrated cross sections for low and intermediate energies of the incoming neutrino. The nuclear wave functions for the initial and final nuclear states are constructed in the context of the quasi-particle random phase approximation (QRPA) tested on the reproducibility of the low-lying energy spectrum. The results presented here refer to the isotopes Mo{sup 92}, Mo{sup 94}, Mo{sup 96}, Mo{sup 98} and Mo{sup 100}. These isotopes could play a significant role in supernova neutrino detection in addition to their use in double-beta and neutrinoless double-beta decay experiments (e.g. MOON, NEMO III)

  1. DOE - Office of Legacy Management -- United Nuclear Corp - MO 0-03

    Office of Legacy Management (LM)

    Nuclear Corp - MO 0-03 FUSRAP Considered Sites Site: UNITED NUCLEAR CORP. (MO.0-03) Eliminated from further consideration under FUSRAP Designated Name: Not Designated Alternate Name: Mallinckrodt Chemical Works Mallinckrodt Nuclear Corporation MO.0-03-1 MO.0-03-2 Location: Hematite , Missouri MO.0-03-1 Evaluation Year: Circa 1987 MO.0-03-3 Site Operations: Commercial fuel fabrication operation. Licensed to reclaim unirradiated enriched uranium from scrap generated in fuel fabrication and fuel

  2. Structure of Mo(VI) complexes. VI. Mo(VI) oxodiperoxo complexes with urea and some of its derivatives

    SciTech Connect (OSTI)

    Timosheva, A.P.; Kazakova, E.K.; Vul`fson, S.G.

    1995-05-20

    Procedures for synthesizing Mo(VI) oxodiperoxo complexes with urea and some of its derivatives have been described. The dipole moment of the peroxo molybdenum complex with hexametapol and urea, [MoO{sub 5}(HMPT)CO(NH{sub 2}){sub 2}], has been determined, and its structure has been proposed. 10 refs.

  3. NNSA NPO M&O Contract Placement Team receives DOE 2015 Secretary...

    National Nuclear Security Administration (NNSA)

    NPO M&O Contract Placement Team receives DOE 2015 Secretary's Achievement Award Wednesday, ... (NPO) Management and Operating (M&O) Contract Placement team recently received the ...

  4. DOE - Office of Legacy Management -- Spencer Chemical Co - MO 0-01

    Office of Legacy Management (LM)

    MO 0-01 FUSRAP Considered Sites Site: SPENCER CHEMICAL CO. (MO.0-01) Eliminated from further consideration under FUSRAP - an AEC licensed operation Designated Name: Not Designated Alternate Name: Jayhawk Works MO.0-01-1 Location: Joplin , Missouri MO.0-01-1 Evaluation Year: 1985 MO.0-01-2 Site Operations: Processed enriched uranium (UF-6) and scrap to produce primarily uranium dioxide (UO-2) under AEC licenses. MO.0-01-3 MO.0-01-4 Site Disposition: Eliminated - No Authority MO.0-01-2 Radioactive

  5. Catalytic activity in lithium-treated core–shell MoOx/MoS2 nanowires

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

    Cummins, Dustin R.; Martinez, Ulises; Kappera, Rajesh; Voiry, Damien; Martinez-Garcia, Alejandro; Jasinski, Jacek; Kelly, Dan; Chhowalla, Manish; Mohite, Aditya D.; Sunkara, Mahendra K.; et al

    2015-09-22

    Significant interest has grown in the development of earth-abundant and efficient catalytic materials for hydrogen generation. Layered transition metal dichalcogenides present opportunities for efficient electrocatalytic systems. Here, we report the modification of 1D MoOx/MoS2 core–shell nanostructures by lithium intercalation and the corresponding changes in morphology, structure, and mechanism of H2 evolution. The 1D nanowires exhibit significant improvement in H2 evolution properties after lithiation, reducing the hydrogen evolution reaction (HER) onset potential by ~50 mV and increasing the generated current density by ~600%. The high electrochemical activity in the nanowires results from disruption of MoS2 layers in the outer shell, leadingmore » to increased activity and concentration of defect sites. This is in contrast to the typical mechanism of improved catalysis following lithium exfoliation, i.e., crystal phase transformation. As a result, these structural changes are verified by a combination of Raman and X-ray photoelectron spectroscopy (XPS).« less

  6. Mo-O bond doping and related-defect assisted enhancement of photoluminescence in monolayer MoS{sub 2}

    SciTech Connect (OSTI)

    Wei, Xiaoxu; Yu, Zhihao; Cheng, Ying; Yu, Linwei; Wang, Junzhuan Wang, Xinran; Shi, Yi; Hu, Fengrui; Wang, Xiaoyong; Xiao, Min

    2014-12-15

    In this work, we report a strong photoluminescence (PL) enhancement of monolayer MoS{sub 2} under different treatments. We find that by simple ambient annealing treatment in the range of 200?C to 400?C, the PL emission can be greatly enhanced by a factor up to two orders of magnitude. This enhancement can be attributed to two factors: first, the formation of Mo-O bonds during ambient exposure introduces an effective p-doping in the MoS{sub 2} layer; second, localized electrons formed around Mo-O bonds related defective sites where the electrons can be effectively localized with higher binding energy resulting in efficient radiative excitons recombination. Time resolved PL decay measurement showed that longer lifetime of the treated sample consistent with the higher quantum efficiency in PL. These results give more insights to understand the luminescence properties of the MoS{sub 2}.

  7. Unusual behavior in magnesium-copper cluster matter produced by helium droplet mediated deposition

    SciTech Connect (OSTI)

    Emery, S. B. Little, B. K.; Xin, Y.; Ridge, C. J.; Lindsay, C. M.; Buszek, R. J.; Boatz, J. A.; Boyle, J. M.

    2015-02-28

    We demonstrate the ability to produce core-shell nanoclusters of materials that typically undergo intermetallic reactions using helium droplet mediated deposition. Composite structures of magnesium and copper were produced by sequential condensation of metal vapors inside the 0.4 K helium droplet baths and then gently deposited onto a substrate for analysis. Upon deposition, the individual clusters, with diameters ∼5 nm, form a cluster material which was subsequently characterized using scanning and transmission electron microscopies. Results of this analysis reveal the following about the deposited cluster material: it is in the un-alloyed chemical state, it maintains a stable core-shell 5 nm structure at sub-monolayer quantities, and it aggregates into unreacted structures of ∼75 nm during further deposition. Surprisingly, high angle annular dark field scanning transmission electron microscopy images revealed that the copper appears to displace the magnesium at the core of the composite cluster despite magnesium being the initially condensed species within the droplet. This phenomenon was studied further using preliminary density functional theory which revealed that copper atoms, when added sequentially to magnesium clusters, penetrate into the magnesium cores.

  8. MAGNESIUM MONO POTASSIUM PHOSPHATE GROUT FOR P-REACTOR VESSEL IN-SITU DECOMISSIONING

    SciTech Connect (OSTI)

    Langton, C.; Stefanko, D.

    2011-01-05

    The objective of this report is to document laboratory testing of magnesium mono potassium phosphate grouts for P-Reactor vessel in-situ decommissioning. Magnesium mono potassium phosphate cement-based grout was identified as candidate material for filling (physically stabilizing) the 105-P Reactor vessel (RV) because it is less alkaline than portland cement-based grout (pH of about 12.4). A less alkaline material ({<=} 10.5) was desired to address a potential materials compatibility issue caused by corrosion of aluminum metal in highly alkaline environments such as that encountered in portland cement grouts. Information concerning access points into the P-Reactor vessel and amount of aluminum metal in the vessel is provided elsewhere. Fresh and cured properties were measured for: (1) commercially blended magnesium mono potassium phosphate packaged grouts, (2) commercially available binders blended with inert fillers at SRNL, (3) grouts prepared from technical grade MgO and KH{sub 2}PO{sub 4} and inert fillers (quartz sands, Class F fly ash), and (4) Ceramicrete{reg_sign} magnesium mono potassium phosphate-based grouts prepared at Argonne National Laboratory. Boric acid was evaluated as a set retarder in the magnesium mono potassium phosphate mixes.

  9. A novel three dimensional semimetallic MoS{sub 2}

    SciTech Connect (OSTI)

    Tang, Zhen-Kun; Zhang, Hui; Liu, Li-Min; Liu, Hao; Lau, Woon-Ming

    2014-05-28

    Transition metal dichalcogenides (TMDs) have many potential applications, while the performances of TMDs are generally limited by the less surface active sites and the poor electron transport efficiency. Here, a novel three-dimensional (3D) structure of molybdenum disulfide (MoS{sub 2}) with larger surface area was proposed based on first-principle calculations. 3D layered MoS{sub 2} structure contains the basal surface and joint zone between the different nanoribbons, which is thermodynamically stable at room temperature, as confirmed by first principles molecular dynamics calculations. Compared the two-dimensional layered structures, the 3D MoS{sub 2} not only owns the large surface areas but also can effectively avoid the aggregation. Interestingly, although the basal surface remains the property of the intrinsic semiconductor as the bulk MoS{sub 2}, the joint zone of 3D MoS{sub 2} exhibits semimetallic, which is derived from degenerate 3d orbitals of the Mo atoms. The high stability, large surface area, and high conductivity make 3D MoS{sub 2} have great potentials as high performance catalyst.

  10. MAGNESIUM ISOTOPE RATIOS IN {omega} CENTAURI RED GIANTS

    SciTech Connect (OSTI)

    Da Costa, G. S.; Norris, John E.; Yong, David

    2013-05-20

    We have used the high-resolution observations obtained at the Anglo-Australian Telescope with Ultra-High Resolution Facility (R {approx} 100,000) and at Gemini-S with b-HROS (R {approx} 150,000) to determine magnesium isotope ratios for seven {omega} Cen red giants that cover a range in iron abundance from [Fe/H] = -1.78 to -0.78 dex, and for two red giants in M4 (NGC 6121). The {omega} Cen stars sample both the ''primordial'' (i.e., O-rich, Na- and Al-poor) and the ''extreme'' (O-depleted, Na- and Al-rich) populations in the cluster. The primordial population stars in both {omega} Cen and M4 show ({sup 25}Mg, {sup 26}Mg)/{sup 24}Mg isotopic ratios that are consistent with those found for the primordial population in other globular clusters with similar [Fe/H] values. The isotopic ratios for the {omega} Cen extreme stars are also consistent with those for extreme population stars in other clusters. The results for the extreme population stars studied indicate that the {sup 26}Mg/{sup 24}Mg ratio is highest at intermediate metallicities ([Fe/H] < -1.4 dex), and for the highest [Al/Fe] values. Further, the relative abundance of {sup 26}Mg in the extreme population stars is notably higher than that of {sup 25}Mg, in contrast to model predictions. The {sup 25}Mg/{sup 24}Mg isotopic ratio in fact does not show any obvious dependence on either [Fe/H] or [Al/Fe] nor, intriguingly, any obvious difference between the primordial and extreme population stars.

  11. Lightning arrestor connector lead magnesium niobate qualification pellet test procedures.

    SciTech Connect (OSTI)

    Tuohig, W.; Mahoney, Patrick A.; Tuttle, Bruce Andrew; Wheeler, Jill Susanne

    2009-02-01

    Enhanced knowledge preservation for DOE DP technical component activities has recently received much attention. As part of this recent knowledge preservation effort, improved documentation of the sample preparation and electrical testing procedures for lead magnesium niobate--lead titanate (PMN/PT) qualification pellets was completed. The qualification pellets are fabricated from the same parent powders used to produce PMN/PT lightning arrestor connector (LAC) granules at HWF&T. In our report, the procedures for fired pellet surface preparation, electrode deposition, electrical testing and data recording are described. The dielectric measurements described in our report are an information only test. Technical reasons for selecting the electrode material, electrode size and geometry are presented. The electrical testing is based on measuring the dielectric constant and dissipation factor of the pellet during cooling from 280 C to 220 C. The most important data are the temperature for which the peak dielectric constant occurs (Curie Point temperature) and the peak dielectric constant magnitude. We determined that the peak dielectric constant for our procedure would be that measured at 1 kHz at the Curie Point. Both the peak dielectric constant and the Curie point parameters provide semi-quantitative information concerning the chemical and microstructural homogeneity of the parent material used for the production of PMN/PT granules for LACs. Finally, we have proposed flag limits for the dielectric data for the pellets. Specifically, if the temperature of the peak dielectric constant falls outside the range of 250 C {+-} 30 C we propose that a flag limit be imposed that will initiate communication between production agency and design agency personnel. If the peak dielectric constant measured falls outside the range 25,000 {+-} 10,000 we also propose that a flag limit be imposed.

  12. Structural studies of magnesium nitride fluorides by powder neutron diffraction

    SciTech Connect (OSTI)

    Brogan, Michael A.; Hughes, Robert W.; Smith, Ronald I.; Gregory, Duncan H.

    2012-01-15

    Samples of ternary nitride fluorides, Mg{sub 3}NF{sub 3} and Mg{sub 2}NF have been prepared by solid state reaction of Mg{sub 3}N{sub 2} and MgF{sub 2} at 1323-1423 K and investigated by powder X-ray and powder neutron diffraction techniques. Mg{sub 3}NF{sub 3} is cubic (space group: Pm3m) and has a structure related to rock-salt MgO, but with one cation site vacant. Mg{sub 2}NF is tetragonal (space group: I4{sub 1}/amd) and has an anti-LiFeO{sub 2} related structure. Both compounds are essentially ionic and form structures in which nitride and fluoride anions are crystallographically ordered. The nitride fluorides show temperature independent paramagnetic behaviour between 5 and 300 K. - Graphical abstract: Definitive structures of the ternary magnesium nitride fluorides Mg{sub 3}NF{sub 3} and the lower temperature polymorph of Mg{sub 2}NF have been determined from powder neutron diffraction data. The nitride halides are essentially ionic and exhibit weak temperature independent paramagnetic behaviour. Highlights: Black-Right-Pointing-Pointer Definitive structures of Mg{sub 3}NF{sub 3} and Mg{sub 2}NF were determined by neutron diffraction. Black-Right-Pointing-Pointer Nitride and fluoride anions are crystallographically ordered in both structures. Black-Right-Pointing-Pointer Both compounds exhibit weak, temperature independent paramagnetic behaviour. Black-Right-Pointing-Pointer The compounds are essentially ionic with ionicity increasing with F{sup -} content.

  13. Permitting and solid waste management issues for the Bailly Station wet limestone Advanced Flue Gas Desulfurization (AFGD) system

    SciTech Connect (OSTI)

    Bolinsky, F.T. (Pure Air, Allentown, PA (United States)); Ross, J. (Northern Indiana Public Service Co., Hammond, IN (United States)); Dennis, D.S. (United Engineers and Constructors, Inc., Denver, CO (United States). Stearns-Roger Div.); Huston, J.S. (Environmental Alternatives, Inc., Warren NJ (USA))

    1991-01-01

    Pure Air (a general partnership between Air Products and Chemicals, Inc., and Mitsubishi Heavy Industries America, Inc.). is constructing a wet limestone co-current advanced flue gas desulfurization (AFGD) system that has technological and commercial advantages over conventional FGD systems in the United States. The AFGD system is being installed at the Northern Indiana Public Service Company's Bailly Generating Station near Gary, Indiana. The AFGD system is scheduled to be operational by the Summer, 1992. The AFGD system will remove at least 90 percent of the sulfur dioxide (SO{sub 2}) in the flue gas from Boilers 7 and 8 at the Station while burning 3.2 percent sulfur coal. Also as part of testing the AFGD system, 95 percent removal of SO{sub 2} will be demonstrated on coals containing up to 4.5 percent sulfur. At the same time that SO{sub 2} is removed from the flue gas, a gypsum by-product will be produced which will be used for wallboard manufacturing. Since the AFGD system is a pollution control device, one would expect its installation to be received favorably by the public and regulatory agencies. Although the project was well received by regulatory agencies, on public group (Save the Dunes Council) was initially concerned since the project is located adjacent to the Indiana Dunes National Lakeshore. The purpose of this paper is to describe the project team's experiences in obtaining permits/approvals from regulatory agencies and in dealing with the public. 1 ref., 1 fig., 2 tabs.

  14. Polystyrene/MoS{sub 2}@oleylamine nanocomposites

    SciTech Connect (OSTI)

    Altavilla, Claudia; Ciambelli, Paolo; Fedi, Filippo; Sorrentino, Andrea; Iannace, Salvatore

    2014-05-15

    The effects of adding different concentrations of MoS{sub 2}@oleylamine nano particles on the thermal and mechanical properties of polystyrene (PS) nanocomposites have been investigated. X-ray diffraction and optical microscopy were used to characterize the morphology of the resulting nanocomposites. The thermal stability of the nanocomposites has been characterized by thermogravimetric analysis. It has been found that the MoS{sub 2}@oleylamine nanoparticles have a good compatibility with the PS matrix forming homogeneous dispersion even at high concentrations. The PS/MoS{sub 2}@oleylamine nanocomposites showed enhanced thermal stability in comparison with neat polystyrene.

  15. Slow Mo Guys and Cold Spray | GE Global Research

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

    Slow Mo Guys and Cold Spray Click to email this to a friend (Opens in new window) Share on Facebook (Opens in new window) Click to share (Opens in new window) Click to share on LinkedIn (Opens in new window) Click to share on Tumblr (Opens in new window) Slow Mo Guys and Cold Spray ) The Slow Mo Guys came to GE Global Research in Niskayuna to film our researchers demonstrate a process called "cold spray", in which metal powders are sprayed at high velocities to build a part or add

  16. Coordination Chemistry in magnesium battery electrolytes: how ligands affect their performance

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

    Shao, Yuyan; Liu, Tianbiao L.; Li, Guosheng; Gu, Meng; Nie, Zimin; Engelhard, Mark H.; Xiao, Jie; Lu, Dongping; Wang, Chong M.; Zhang, Jiguang; et al

    2013-11-04

    Magnesium battery is potentially a safe, cost-effective, and high energy density technology for large scale energy storage. However, the development of magnesium battery has been hindered by the limited performance and the lack of fundamental understandings of electrolytes. Here, we present a coordination chemistry study of Mg(BH4)2 in ethereal solvents. The O donor denticity, i.e. ligand strength of the ethereal solvents which act as ligands to form solvated Mg complexes, plays a significant role in enhancing coulombic efficiency of the corresponding solvated Mg complex electrolytes. A new and safer electrolyte is developed based on Mg(BH4)2, diglyme and optimized LiBH4 additive.more » The new electrolyte demonstrates 100% coulombic efficiency, no dendrite formation, and stable cycling performance with the cathode capacity retention of ~90% for 300 cycles in a prototype magnesium battery.« less

  17. Laser beam welding of AZ31B-H24 magnesium alloy.

    SciTech Connect (OSTI)

    Leong, K. H.

    1998-09-29

    The laser beam weldability of AZ31B magnesium alloy was examined with high power CW CO{sub 2} and pulsed Nd:YAG lasers. The low viscosity and surface tension of the melt pool make magnesium more difficult to weld than steel. Welding parameters necessary to obtain good welds were determined for both CW CO{sub 2} and pulsed Nd:YAG lasers. The weldability of the magnesium alloy was significantly better with the Nd:YAG laser. The cause of this improvement was attributed to the higher absorption of the Nd:YAG beam. A lower threshold beam irradiance was required for welding, and a more stable weldpool was obtained.

  18. Coordination Chemistry in magnesium battery electrolytes: how ligands affect their performance

    SciTech Connect (OSTI)

    Shao, Yuyan; Liu, Tianbiao L.; Li, Guosheng; Gu, Meng; Nie, Zimin; Engelhard, Mark H.; Xiao, Jie; Lu, Dongping; Wang, Chong M.; Zhang, Jiguang; Liu, Jun

    2013-11-04

    Magnesium battery is potentially a safe, cost-effective, and high energy density technology for large scale energy storage. However, the development of magnesium battery has been hindered by the limited performance and the lack of fundamental understandings of electrolytes. Here, we present a coordination chemistry study of Mg(BH4)2 in ethereal solvents. The O donor denticity, i.e. ligand strength of the ethereal solvents which act as ligands to form solvated Mg complexes, plays a significant role in enhancing coulombic efficiency of the corresponding solvated Mg complex electrolytes. A new and safer electrolyte is developed based on Mg(BH4)2, diglyme and optimized LiBH4 additive. The new electrolyte demonstrates 100% coulombic efficiency, no dendrite formation, and stable cycling performance with the cathode capacity retention of ~90% for 300 cycles in a prototype magnesium battery.

  19. Development of a Thin-Wall Magnesium side door Inner Panel for Automobiles

    SciTech Connect (OSTI)

    Jekl, J.; Auld, J.; Sweet, C.; Carter, Jon; Resch, Steve; Klarner, A.; Brevick, J.; Luo, A.

    2015-05-17

    Cast magnesium side door inner panels can provide a good combination of weight, functional, manufacturing and economical requirements. However, several challenges exist including casting technology for thin-wall part design, multi-material incompatibility and relatively low strength vs steel. A project has been initiated, supported by the US Department of Energy, to design and develop a lightweight frame-under-glass door having a thin-wall, full die-cast, magnesium inner panel. This development project is the first of its kind within North America. Phase I of the project is now complete and the 2.0mm magnesium design, through casting process enablers, has met or exceeded all stiffness requirements, with significant mass reduction and part consolidation. In addition, a corrosion mitigation strategy has been established using industry-accepted galvanic isolation methods and coating technologies.

  20. Diffusion Barrier Selection from Refractory Metals (Zr, Mo and Nb) via Interdiffusion Investigation for U-Mo RERTR Fuel Alloy

    SciTech Connect (OSTI)

    K. Huang; C. Kammerer; D. D. Keiser, Jr.; Y. H. Sohn

    2014-04-01

    U-Mo alloys are being developed as low enrichment monolithic fuel under the Reduced Enrichment for Research and Test Reactor (RERTR) Program. Diffusional interactions between the U-Mo fuel alloy and Al-alloy cladding within the monolithic fuel plate construct necessitate incorporation of a barrier layer. Fundamentally, a diffusion barrier candidate must have good thermal conductivity, high melting point, minimal metallurgical interaction, and good irradiation performance. Refractory metals, Zr, Mo, and Nb are considered based on their physical properties, and the diffusion behavior must be carefully examined first with U-Mo fuel alloy. Solid-to-solid U-10wt.%Mo vs. Mo, Zr, or Nb diffusion couples were assembled and annealed at 600, 700, 800, 900 and 1000 degrees C for various times. The interdiffusion microstructures and chemical composition were examined via scanning electron microscopy and electron probe microanalysis, respectively. For all three systems, the growth rate of interdiffusion zone were calculated at 1000, 900 and 800 degrees C under the assumption of parabolic growth, and calculated for lower temperature of 700, 600 and 500 degrees C according to Arrhenius relationship. The growth rate was determined to be about 10 3 times slower for Zr, 10 5 times slower for Mo and 10 6 times slower for Nb, than the growth rates reported for the interaction between the U-Mo fuel alloy and pure Al or Al-Si cladding alloys. Zr, however was selected as the barrier metal due to a concern for thermo- mechanical behavior of UMo/Nb interface observed from diffusion couples, and for ductile-to-brittle transition of Mo near room temperature.

  1. Anisotropy of heat conduction in Mo/Si multilayers

    SciTech Connect (OSTI)

    Medvedev, V. V.; Yakshin, A. E.; Kruijs, R. W. E. van de; Bijkerk, F.; Yang, J.; Schmidt, A. J.; Zoethout, E.

    2015-08-28

    This paper reports on the studies of anisotropic heat conduction phenomena in Mo/Si multilayers with individual layer thicknesses selected to be smaller than the mean free path of heat carriers. We applied the frequency-domain thermoreflectance technique to characterize the thermal conductivity tensor. While the mechanisms of the cross-plane heat conduction were studied in detail previously, here we focus on the in-plane heat conduction. To analyze the relative contribution of electron transport to the in-plane heat conduction, we applied sheet-resistance measurements. Results of Mo/Si multilayers with variable thickness of the Mo layers indicate that the net in-plane thermal conductivity depends on the microstructure of the Mo layers.

  2. Structural Insights into FeMo Cofactor Biosynthesis

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

    a catalytic component and a specific reductase, which, in the standard system, are referred to as the MoFe protein and the Fe protein. At the active site of the...

  3. CO2ReMoVe | Open Energy Information

    Open Energy Info (EERE)

    of industrial, research and service organizations with experience in CO2 geological storage. References: CO2ReMoVe1 This article is a stub. You can help OpenEI by expanding...

  4. Support effects on hydrotreating activity of NiMo catalysts

    SciTech Connect (OSTI)

    Dominguez-Crespo, M.A. Arce-Estrada, E.M.; Torres-Huerta, A.M.

    2007-10-15

    The effect of the gamma alumina particle size on the catalytic activity of NiMoS{sub x} catalysts prepared by precipitation method of aluminum acetate at pH = 10 was studied. The structural characterization of the supports was measured by using XRD, pyridine FTIR-TPD and nitrogen physisorption. NiMo catalysts were characterized during the preparation steps (annealing and sulfidation) using transmission electron microscopy (TEM). Hydrogen TPR studies of the NiMo catalysts were also carried out in order to correlate their hydrogenating properties and their catalytic functionality. Catalytic tests were carried out in a pilot plant at 613, 633 and 653 K temperatures. The results showed that the rate constants of hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and hydrodearomatizing (HDA) at 613-653 K decreased in the following order: A > B > C corresponding to the increase of NiMoS particle size associated to these catalysts.

  5. 9 Cr-- 1 Mo steel material for high temperature application

    DOE Patents [OSTI]

    Jablonski, Paul D; Alman, David; Dogan, Omer; Holcomb, Gordon; Cowen, Christopher

    2012-11-27

    One or more embodiments relates to a high-temperature, titanium alloyed, 9 Cr-1 Mo steel exhibiting improved creep strength and oxidation resistance at service temperatures up to 650.degree. C. The 9 Cr-1 Mo steel has a tempered martensite microstructure and is comprised of both large (0.5-3 .mu.m) primary titanium carbides and small (5-50 nm) secondary titanium carbides in a ratio of. from about 1:1.5 to about 1.5:1. The 9 Cr-1 Mo steel may be fabricated using exemplary austenizing, rapid cooling, and tempering steps without subsequent hot working requirements. The 9 Cr-1 Mo steel exhibits improvements in total mass gain, yield strength, and time-to-rupture over ASTM P91 and ASTM P92 at the temperature and time conditions examined.

  6. Co-Mo Electric Cooperative- Energy Efficiency Rebate Program

    Broader source: Energy.gov [DOE]

    Co-Mo Electric Cooperative provides rebates to its residential and commercial members who install air source, dual fuel, and/or geothermal heat pumps, and certain energy efficient appliances. Heat...

  7. M.O. Wascko, LSU NuInt05...

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

    O. Wascko, LSU NuInt05 26 September, 2005 MiniBooNE CC + CCQE Ratio M.O. Wascko, LSU J.R. Monroe, Columbia CC interactions Quasi-Elastic (CCQE) Inclusive Single +...

  8. Ethanol Conversion on Cyclic (MO3)3 (M = Mo, W) Clusters

    SciTech Connect (OSTI)

    Li, Zhenjun; Fang, Zongtang; Kelley, Matthew S.; Kay, Bruce D.; Rousseau, Roger J.; Dohnalek, Zdenek; Dixon, David A.

    2014-03-06

    Oxides of molybdenum and tungsten are an important class of catalytic materials with applications ranging from isomerization of alkanes and alkenes, partial oxidation of alcohols, selective reduction of nitric oxide and metathesis of alkeness.[1-10] While many studies have focused on the structure - function relationships, the nature of high catalytic activity is still being extensively investigated. There is a general agreement that the activity of supported MOx (M = W, Mo) catalysts is correlated with the presence of acidic sites, where the catalytic activity is strongly affected by the type of oxide support, delocalization of electron density, structures of tungsten oxide domains and presence of protons

  9. DOE - Office of Legacy Management -- Medart Co - MO 09

    Office of Legacy Management (LM)

    Medart Co - MO 09 FUSRAP Considered Sites Site: MEDART CO. (MO.09 ) Eliminated from consideration under FUSRAP - Facility believed to be torn down and the original site built over Designated Name: Not Designated Alternate Name: None Location: 180 Potomoc Street , St. Louis , Missouri MA.09-4 Evaluation Year: Circa 1990 MA.09-3 Site Operations: Conducted test machining operations on uranium bar stock during the early 1950s. MA.09-2 Site Disposition: Eliminated - Potential for contamination

  10. Microstructures in rapidly solidified Ni-Mo alloys

    SciTech Connect (OSTI)

    Jayaraman, N.; Tewari, S.N.; Hemker, K.J.; Glasgow, T.K.

    1985-01-01

    Ni-Mo alloys of compositions ranging from pure Ni to Ni-40 at % Mo were rapidly solidified by chill block melt spinning in vacuum and were examined by optical metallography, x-ray diffraction and transmission electron microscopy. Rapid solidification resulted in an extension of molybdenum solubility in nickel from 28 to 37.5 at %. A number of different phases and microstructures were seen at different depths (solidification conditions) from the quenched surface of the melt spun ribbons.

  11. DOE - Office of Legacy Management -- St Louis University - MO 0-02

    Office of Legacy Management (LM)

    University - MO 0-02 FUSRAP Considered Sites Site: ST. LOUIS UNIVERSITY (MO.0-02) Eliminated from consideration under FUSRAP - As of 1987 the facility operated under an NRC license Designated Name: Not Designated Alternate Name: None Location: St. Louis , Missouri MO.0-02-1 Evaluation Year: 1987 MO.0-02-1 Site Operations: Performed research activities involving small quantities of radioactive materials in a controlled environment. MO.0-02-1 Site Disposition: Eliminated - No Authority - Potential

  12. Coated U(Mo) Fuel: As-Fabricated Microstructures

    SciTech Connect (OSTI)

    Emmanuel Perez; Dennis D. Keiser, Jr.; Ann Leenaers; Sven Van den Berghe; Tom Wiencek

    2014-04-01

    As part of the development of low-enriched uranium fuels, fuel plates have recently been tested in the BR-2 reactor as part of the SELENIUM experiment. These fuel plates contained fuel particles with either Si or ZrN thin film coating (up to 1 µm thickness) around the U-7Mo fuel particles. In order to best understand irradiation performance, it is important to determine the starting microstructure that can be observed in as-fabricated fuel plates. To this end, detailed microstructural characterization was performed on ZrN and Si-coated U-7Mo powder in samples taken from AA6061-clad fuel plates fabricated at 500°C. Of interest was the condition of the thin film coatings after fabrication at a relatively high temperature. Both scanning electron microscopy and transmission electron microscopy were employed. The ZrN thin film coating was observed to consist of columns comprised of very fine ZrN grains. Relatively large amounts of porosity could be found in some areas of the thin film, along with an enrichment of oxygen around each of the the ZrN columns. In the case of the pure Si thin film coating sample, a (U,Mo,Al,Si) interaction layer was observed around the U-7Mo particles. Apparently, the Si reacted with the U-7Mo and Al matrix during fuel plate fabrication at 500°C to form this layer. The microstructure of the formed layer is very similar to those that form in U-7Mo versus Al-Si alloy diffusion couples annealed at higher temperatures and as-fabricated U-7Mo dispersion fuel plates with Al-Si alloy matrix fabricated at 500°C.

  13. The cluster compound In{sub 4}Ti{sub 1.5}Mo{sub 0.5}Mo{sub 14}O{sub 26} containing Mo{sub 14} clusters and the new mono- and bi-capped trioctahedral Mo{sub 15} and Mo{sub 16} clusters: Synthesis, crystal structure, and electrical and magnetic properties

    SciTech Connect (OSTI)

    Gall, Philippe; Guizouarn, Thierry; Gougeon, Patrick

    2015-07-15

    Single crystals of the new quaternary compound In{sub 4}Ti{sub 1.5}Mo{sub 0.5}Mo{sub 14}O{sub 26} were obtained by solid state reaction. The crystal structure was determined by single-crystal X-ray diffraction. In{sub 4}Ti{sub 1.5}Mo{sub 0.5}Mo{sub 14}O{sub 26} crystallizes in the orthorhombic space group Pbca with unit-cell parameters a=9.4432(14) Å, b=11.4828(12) Å, c=20.299(4) Å and Z=4. Full-matrix least-squares refinement on F{sup 2} using 3807 independent reflections for 219 refinable parameters resulted in R{sub 1}=0.0259 and wR{sub 2}=0.0591. The crystal structure contains in addition to Mo{sub 14} clusters the first examples of mono- and bi-capped trioctahedral Mo{sub 14} i.e. Mo{sub 15} and Mo{sub 16} clusters. The oxygen framework derives from a stacking along the a direction of close-packed layers with sequence (…ABAC…). The Mo–Mo distances range between 2.6938(5) and 2.8420(6) Å and the Mo–O distances between 1.879(5) and 2.250(3) Å, as usually observed in molybdenum oxide clusters. The indium atoms form In{sub 4}{sup 6+} bent chains with In–In distances of 2.6682(5) and 2.6622(8) Å and the Ti atoms are in highly distorted octahedral sites of oxygen atoms with Ti–O distances ranging between 1.865(4) and 2.161(4) Å. Magnetic susceptibility measurements confirm the presence of Ti{sup 4+} cations and the absence of localized moments on the Mo network. Electrical resistivity measurements on a single crystal of In{sub 4}Ti{sub 1.5}Mo{sub 0.5}Mo{sub 14}O{sub 26} show a semimetallic behavior. - Graphical abstract: We present here the synthesis, the crystal structure, and the electrical and magnetic properties of the new compound In{sub 4}Ti{sub 1.5}Mo{sub 0.5}Mo{sub 14}O{sub 26} in which Mo{sub 14} clusters coexist statistically with mono- and bi-capped trioctahedral Mo{sub 14} that is Mo{sub 15} and Mo{sub 16} clusters. - Highlights: • Single crystals of In{sub 4}Ti{sub 1.5}Mo{sub 0.5}Mo{sub 14}O{sub 26} were obtained by solid state

  14. Multiphonon resonant Raman scattering in MoS{sub 2}

    SciTech Connect (OSTI)

    Gołasa, K. Grzeszczyk, M.; Wysmołek, A.; Babiński, A.; Leszczyński, P.; Faugeras, C.; Nicolet, A. A. L.; Potemski, M.

    2014-03-03

    Optical emission spectrum of a resonantly (λ = 632.8 nm) excited molybdenum disulfide (MoS{sub 2}) is studied at liquid helium temperature. More than 20 peaks in the energy range spanning up to 1400 cm{sup −1} from the laser line, which are related to multiphonon resonant Raman scattering processes, are observed. The attribution of the observed lines involving basic lattice vibrational modes of MoS{sub 2} and both the longitudinal (LA(M)) and the transverse (TA(M) and/or ZA(M)) acoustic phonons from the vicinity of the high-symmetry M point of the MoS{sub 2} Brillouin zone is proposed.

  15. Ligand Bridging-Angle-Driven Assembly of Molecular Architectures Based on Quadruply Bonded Mo-Mo Dimers

    SciTech Connect (OSTI)

    Li, Jian-Rong; Yakovenko, Andrey A; Lu, Weigang; Timmons, Daren J; Zhuang, Wenjuan; Yuan, Daqiang; Zhou, Hong-Cai

    2010-12-15

    A systematic exploration of the assembly of Mo?(O?C-)?-based metalorganic molecular architectures structurally controlled by the bridging angles of rigid organic linkers has been performed. Twelve bridging dicarboxylate ligands were designed to be of different sizes with bridging angles of 0, 60, 90, and 120 while incorporating a variety of nonbridging functional groups, and these ligands were used as linkers. These dicarboxylate linkers assemble with quadruply bonded MoMo clusters acting as nodes to give 13 molecular architectures, termed metalorganic polygons/polyhedra with metal cluster node arrangements of a linear shape, triangle, octahedron, and cuboctahedron/anti-cuboctahedron. The syntheses of these complexes have been optimized and their structures determined by single-crystal X-ray diffraction. The results have shown that the shape and size of the resulting molecular architecture can be controlled by tuning the bridging angle and size of the linker, respectively. Functionalization of the linker can adjust the solubility of the ensuing molecular assembly but has little or no effect on the geometry of the product. Preliminary gas adsorption, spectroscopic, and electrochemical properties of selected members were also studied. The present work is trying to enrich metal-containing supramolecular chemistry through the inclusion of well-characterized quadruply bonded MoMo units into the structures, which can widen the prospect of additional electronic functionality, thereby leading to novel properties.

  16. Synthesis and Structural Characterization of Magnesium Based Coordination Networks in Different Solvents

    SciTech Connect (OSTI)

    Banerjee, Debasis; Finkelstein, Jeffrey; Smirnov, A.; Forster, Paul M.; Borkowski, Lauren A.; Teat, Simon J.; Parise, John B.

    2015-10-15

    Three magnesium based metal-organic frameworks, Mg{sub 3}(3,5-PDC){sub 3}(DMF){sub 3} {center_dot} DMF [1], Mg(3,5-PDC)(H{sub 2}O) {center_dot} (H{sub 2}O) [3], and Mg4(3,5-PDC)4(DMF){sub 2}(H{sub 2}O){sub 2} {center_dot} 2DMF {center_dot} 4.5H{sub 2}O [4], and a 2-D coordination polymer, [Mg(3,5-PDC)(H{sub 2}O){sub 2}] [2] [PDC = pyridinedicarboxylate], were synthesized using a combination of DMF, methanol, ethanol, and water. Compound 1 [space group P2{sub 1}/n, a = 12.3475(5) {angstrom}, b = 11.1929(5) {angstrom}, c = 28.6734(12) {angstrom}, {beta} = 98.8160(10){sup o}, V = 3916.0(3) {angstrom}{sup 3}] consists of a combination of isolated and corner-sharing magnesium octahedra connected by the organic linkers to form a 3-D network with a 12.2 {angstrom} x 4.6 {angstrom} 1-D channel. The channel contains coordinated and free DMF molecules. In compound 2 [space group C2/c, a = 9.964(5) {angstrom}, b = 12.0694(6) {angstrom}, c = 7.2763(4) {angstrom}, {beta} = 106.4970(6){sup o}, V = 836.70(6) {angstrom}{sup 3}], PDC connects isolated seven coordinated magnesium polyhedra into a layered structure. Compound 3 [space group P6{sub 1}22, a = 11.479(1) {angstrom}, c = 14.735(3) {angstrom}, V = 1681.7(4) {angstrom}{sup 3}] (previously reported) contains isolated magnesium octahedra connected by the organic linker with each other forming a 3D network. Compound 4 [space group P2{sub 1}/c, a = 13.7442(14) {angstrom}, b = 14.2887(15) {angstrom}, c = 14.1178(14) {angstrom}, {beta} = 104.912(2){sup o}, V = 2679.2(5) {angstrom}{sup 3}] also exhibits a 3D network based on isolated magnesium octahedra with square cavities containing both disordered DMF and water molecules. The structural topologies originate due to the variable coordination ability of solvent molecules with the metal center. Water molecules coordinate with the magnesium metal centers preferably over other polar solvents (DMF, methanol, ethanol) used to synthesize the coordination networks. Despite testing

  17. Vehicle Technologies Office Merit Review 2014: Scale-Up of Magnesium Production by Fully Stabilized Zirconia Electrolysis

    Broader source: Energy.gov [DOE]

    Presentation given by INFINIUM, Inc. at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about scale-up of magnesium...

  18. Vehicle Technologies Office Merit Review 2015: Scale-Up of Magnesium Production by Fully Stabilized Zirconia Electrolysis

    Broader source: Energy.gov [DOE]

    Presentation given by INFINIUM, Inc. at 2015 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about scale-up of magnesium...

  19. U-Mo Plate Blister Anneal Interim Report

    SciTech Connect (OSTI)

    Francine J. Rice; Daniel M. Wachs; Adam B. Robinson; Dennis D. Keiser Jr.; Jan-Fong Jue; Danielle M. Perez; Ross Finlay

    2010-10-01

    Blister thresholds in fuel elements have been a longstanding performance parameter for fuel elements of all types. This behavior has yet to be fully defined for the RERTR U-Mo fuel types. Blister anneal studies that began in 2007 have been expanded to include plates from more recent RERTR experiments. Preliminary data presented in this report encompasses the early generations of the U-Mo fuel systems and the most recent but still developing fuel system. Included is an overview of relevant dispersion fuel systems for the purposes of comparison.

  20. LICENSE HISTORY MO.8 Petrolite Corporation, St. Louis

    Office of Legacy Management (LM)

    LICENSE HISTORY MO.8 Petrolite Corporation, St. Louis 07,16/93 l See attached Document and Pile Sumnary for MO.8 l License History: l 24-10452-01, 30-051175, 08/13/79. Loose H-3, I-131, P-32. l 24-10452-1, 10/30/64. K66 R. R. Annand et al Multiple. . 70-621, 12-15-61, SNM license for 0.5 kg. of U-235, 93% enriched as a fuel loading and star-up ~curce for Webster Groves, Missouri reactor. l Discussion: Historical documents for this site are limited. The only information available on work done

  1. Sol-Gel Preparation Of Lead Magnesium Ni Obate (Pmn) Powdersand Thin Films

    DOE Patents [OSTI]

    Boyle, Timothy J.

    1999-01-12

    A method of preparing a lead magnesium niobium oxide (PMN), Pb(Mg.sub.1/3 Nb.sub.2/3)O.sub.3, precursor solution by a solvent method wherein a liquid solution of a lead-complex PMN precursor is combined with a liquid solution of a niobium-complex PMN precursor, the combined lead- and niobium-complex liquid solutions are reacted with a magnesium-alkyl solution, forming a PMN precursor solution and a lead-based precipitate, and the precipitate is separated from the reacted liquid PMN precursor solution to form a precipitate-free PMN precursor solution. This precursor solution can be processed to form both ferroelectric powders and thin films.

  2. Sol-gel preparation of lead magnesium niobate (PMN) powders and thin films

    DOE Patents [OSTI]

    Boyle, T.J.

    1999-01-12

    A method of preparing a lead magnesium niobium oxide (PMN), Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}, precursor solution by a solvent method wherein a liquid solution of a lead-complex PMN precursor is combined with a liquid solution of a niobium-complex PMN precursor, the combined lead- and niobium-complex liquid solutions are reacted with a magnesium-alkyl solution, forming a PMN precursor solution and a lead-based precipitate, and the precipitate is separated from the reacted liquid PMN precursor solution to form a precipitate-free PMN precursor solution. This precursor solution can be processed to form both ferroelectric powders and thin films. 3 figs.

  3. The effect of rare earth elements on the texture and formability of asymmetrically rolled magnesium sheet

    SciTech Connect (OSTI)

    Alderman, Dr. Martyn; Cavin, Odis Burl; Davis, Dr. Bruce; Muralidharan, Govindarajan; Muth, Thomas R; Peter, William H; Randman, David; Watkins, Thomas R

    2011-01-01

    The lack of formability is a serious issue when considering magnesium alloys for various applications. Standard symmetric rolling introduces a strong basal texture that decreases the formability; however, asymmetric rolling has been put forward as a possible route to produce sheet with weaker texture and greater ductility. It has also been shown in recent work that weaker textures can be produced through the addition of rare earth elements to magnesium alloys. Therefore, this study has been carried out to investigate the effect of rare earth additions on the texture changes during asymmetric rolling. Two alloys have been used, AZ31B and ZEK100. The effect that the rare earth additions have on the texture of asymmetrically rolled sheet and the subsequent changes in formability will be discussed.

  4. Large scale two-dimensional arrays of magnesium diboride superconducting quantum interference devices

    SciTech Connect (OSTI)

    Cybart, Shane A. Dynes, R. C.; Wong, T. J.; Cho, E. Y.; Beeman, J. W.; Yung, C. S.; Moeckly, B. H.

    2014-05-05

    Magnetic field sensors based on two-dimensional arrays of superconducting quantum interference devices were constructed from magnesium diboride thin films. Each array contained over 30?000 Josephson junctions fabricated by ion damage of 30?nm weak links through an implant mask defined by nano-lithography. Current-biased devices exhibited very large voltage modulation as a function of magnetic field, with amplitudes as high as 8?mV.

  5. Letter on the Office of Science M&O Contract Study and the Univerisity...

    Office of Environmental Management (EM)

    of Science M&O Contract Study and the Univerisity of Minnesota 's Institute for Mathematics and its Applications Letter on the Office of Science M&O Contract Study and the ...

  6. Policy Flash 2013-71 AL 2013-11 NON M&O CONTRACTOR BUSINESS SYSTEMS...

    Energy Savers [EERE]

    Policy Flash 2013-71 AL 2013-11 NON M&O CONTRACTOR BUSINESS SYSTEMS CLAUSES FOR SECTION H Policy Flash 2013-71 AL 2013-11 NON M&O CONTRACTOR BUSINESS SYSTEMS CLAUSES FOR SECTION H...

  7. Domestic production of medical isotope Mo-99 moves a step closer

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

    Domestic production of medical isotope Mo-99 Domestic production of medical isotope Mo-99 moves a step closer Irradiated uranium fuel has been recycled and reused for molybdenum-99 ...

  8. CO{sub 2} laser beam welding of magnesium-based alloys

    SciTech Connect (OSTI)

    Weisheit, A.; Galun, R.; Mordike, B.L.

    1998-04-01

    Magnesium has gained increased attention in recent years as a structural metal--especially in the automotive industry--necessitating the development of welding techniques qualified for this new application. Lasers are known to be an excellent tool for joining metals. This paper presents results of recent investigations on the weldability of several cast and wrought magnesium-based alloys. Plates with a thickness of 2.5--8 mm were butt joint welded with and without filler metal using a 2.5-kW CO{sub 2} laser. The investigations showed that magnesium alloys can be easily laser welded in similar and dissimilar joints. The beam characteristics of the laser leads to small welds and a deep penetration depth. Crackfree welds exhibiting low porosity and good surface finish can be achieved with appropriate process parameters. Generally, the laser welding leads to either no change or a small increase in hardness in the fusion zone (FZ) and in the heat-affected zone (HAZ) relative to the base metal. Less promising results were obtained for the cast alloy QE22, in which cracking in the age-hardened condition and a significant decrease in hardness occurred. Laser welded die cast alloys showed an extremely high level of porosity in the weld.

  9. Process for CO.sub.2 capture using a regenerable magnesium hydroxide sorbent

    DOE Patents [OSTI]

    Siriwardane, Ranjani V; Stevens, Jr., Robert W

    2013-06-25

    A process for CO.sub.2 separation using a regenerable Mg(OH).sub.2 sorbent. The process absorbs CO.sub.2 through the formation of MgCO.sub.3 and releases water product H.sub.2O. The MgCO.sub.3 is partially regenerated through direct contact with steam, which acts to heat the magnesium carbonate to a higher temperature, provide heat duty required to decompose the magnesium carbonate to yield MgO and CO.sub.2, provide an H.sub.2O environment over the magnesium carbonate thereby shifting the equilibrium and increasing the potential for CO.sub.2 desorption, and supply H.sub.2O for rehydroxylation of a portion of the MgO. The mixture is polished in the absence of CO.sub.2 using water product H.sub.2O produced during the CO.sub.2 absorption to maintain sorbent capture capacity. The sorbent now comprised substantially of Mg(OH).sub.2 is then available for further CO.sub.2 absorption duty in a cyclic process.

  10. Characterization of fold defects in AZ91D and AE42 magnesium alloy permanent mold castings

    SciTech Connect (OSTI)

    Bichler, L. [Centre for Near-net-shape Processing of Materials, Ryerson University, 101 Gerrard St. E., Toronto, M5B 2K3 (Canada); Ravindran, C., E-mail: rravindr@ryerson.ca [Centre for Near-net-shape Processing of Materials, Ryerson University, 101 Gerrard St. E., Toronto, M5B 2K3 (Canada)

    2010-03-15

    Casting premium-quality magnesium alloy components for aerospace and automotive applications poses unique challenges. Magnesium alloys are known to freeze rapidly prior to filling a casting cavity, resulting in misruns and cold shuts. In addition, melt oxidation, solute segregation and turbulent metal flow during casting contribute to the formation of fold defects. In this research, formation of fold defects in AZ91D and AE42 magnesium alloys cast via the permanent mold casting process was investigated. Computer simulations of the casting process predicted the development of a turbulent metal flow in a critical casting region with abrupt geometrical transitions. SEM and light optical microscopy examinations revealed the presence of folds in this region for both alloys. However, each alloy exhibited a unique mechanism responsible for fold formation. In the AZ91D alloy, melt oxidation and velocity gradients in the critical casting region prevented fusion of merging metal front streams. In the AE42 alloy, limited solubility of rare-earth intermetallic compounds in the {alpha}-Mg phase resulted in segregation of Al{sub 2}RE particles at the leading edge of a metal front and created microstructural inhomogeneity across the fold.

  11. Manufacturing of SiCp Reinforced Magnesium Composite Tubes by Hot Extrusion Processes

    SciTech Connect (OSTI)

    Hwang, Yeong-Maw; Huang, Song-Jeng; Huang, Yu-San

    2011-05-04

    Magnesium alloys have higher specific strength compared with other metals, such as aluminum, copper and steel. Nevertheless, their ductility is still not good for further metal forming and their strength is not large enough for real structure applications. The aim of this paper is to develop magnesium alloy composite tubes reinforced with SiC particulates by the stir-casting method and hot extrusion processes. At first, AZ61/SiCp composite ingots reinforced with 5 wt% SiC particulates are fabricated by the melt-stirring technique. Then, finite element simulations are conducted to analyze the plastic flow of magnesium alloy AZ61 within the die and the temperature distribution of the products. AZ61/SiCp composite tubes are manufactured by hot extrusion using a specially designed die-set for obtaining uniform thickness distribution tubes. Finally, the mechanical properties of the reinforced AZ61/SiCp composite and Mg alloy AZ61 tubes are compared with those of the billets to manifest the advantages of extrusion processes and reinforcement of SiC particulates. The microstructures of the billet and extruded tubes are also observed. Through the improvement of the strength of the tube product, its life cycle can be extended and the energy consumption can be reduced, and eventually the environmental sustainability is achieved.

  12. Magnesite Step Growth Rates as a Function of the Aqueous Magnesium:Carbonate Ratio

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

    Bracco, Jacquelyn N.; Stack, Andrew G.; Higgins, Steven R.

    2014-10-01

    Step velocities of monolayer-height steps on the (101⁻4) magnesite surface have been measured as functions of the aqueous magnesium-to-carbonate ratio and saturation index (SI) using a hydrothermal atomic force microscope (HAFM). At SI ≤ 1.9 and 80-90 °C, step velocities were found to be invariant with changes in the magnesium-to-carbonate ratio, an observation in contrast with standard models for growth and dissolution of ionically-bonded, multi-component crystals. However, at high saturation indices (SI = 2.15), step velocities displayed a ratio dependence, maximized at magnesium-to-carbonate ratios slightly greater than 1:1. Traditional affinity-based models were unable to describe growth rates at the highermore » saturation index. Step velocities also could not be modeled solely through nucleation of kink sites, in contrast to other minerals whose bonding between constituent ions is also dominantly ionic in nature, such as calcite and barite. Instead, they could be described only by a model that incorporates both kink nucleation and propagation. Based on observed step morphological changes at these higher saturation indices, the step velocity maximum at SI = 2.15 is likely due to the rate of attachment to propagating kink sites overcoming the rate of detachment from kink sites as the latter becomes less significant under far from equilibrium conditions.« less

  13. Corrosion report for the U-Mo fuel concept

    SciTech Connect (OSTI)

    Henager, Jr., Charles H.; Bennett, Wendy D.; Doherty, Ann L.; Fuller, E. S.; Hardy, John S.; Omberg, Ronald P.

    2014-08-28

    The Fuel Cycle Research and Development (FCRD) program of the Office of Nuclear Energy (NE) has implemented a program to develop a Uranium-Molybdenum (U-Mo) metal fuel for Light Water Reactors (LWR)s. Uranium-Molybdenum fuel has the potential to provide superior performance based on its thermo-physical properties, which includes high thermal conductivity for less stored heat energy. With sufficient development, it may be able to provide the Light Water industry with a melt-resistant accident tolerant fuel with improved safety response. However, the corrosion of this fuel in reactor water environments needs to be further explored and optimized by additional alloying. The Pacific Northwest National Laboratory has been tasked with performing ex-reactor corrosion testing to characterize the performance of U-Mo fuel. This report documents the results of the effort to characterize and develop the U-Mo metal fuel concept for LWRs with regard to corrosion testing. The results of a simple screening test in buffered water at 30°C using surface alloyed U-10Mo is documented and discussed. The screening test was used to guide the selection of several potential alloy improvements that were found and are recommended for further testing in autoclaves to simulate PWR water conditions more closely.

  14. Defects Engineered Monolayer MoS2 for Improved Hydrogen Evolution Reaction

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

    Ye, Gonglan; Gong, Yongji; Lin, Junhao; Li, Bo; He, Yongmin; Pantelides, Sokrates T.; Zhou, Wu; Vajtai, Robert; Ajayan, Pulickel M.

    2016-01-13

    MoS2 is a promising, low-cost material for electrochemical hydrogen production due to its high activity and stability during the reaction. Our work represents an easy method to increase the hydrogen production in electrochemical reaction of MoS2 via defect engineering, and helps to understand the catalytic properties of MoS2.

  15. Tuning magnetism of monolayer MoS{sub 2} by doping vacancy and applying strain

    SciTech Connect (OSTI)

    Zheng, Huiling; Yang, Baishun; Han, Ruilin; Du, Xiaobo; Yan, Yu; Wang, Dingdi

    2014-03-31

    In view of important role of inducing and manipulating the magnetism in two-dimensional materials for the development of low-dimensional spintronic devices, the influences of strain on electronic structure and magnetic properties of commonly observed vacancies doped monolayer MoS{sub 2} are investigated using first-principles calculations. It is shown that unstrained V{sub S}, V{sub S2}, and V{sub MoS3} doped monolayer MoS{sub 2} systems are nonmagnetic, while the ground state of unstrained V{sub MoS6} doped system is magnetic and the magnetic moment is contributed mainly by six Mo atoms around V{sub MoS6}. In particular, tensile strain can induce magnetic moments in V{sub S}, V{sub S2}, and V{sub MoS3} doped monolayer MoS{sub 2} due to the breaking of Mo–Mo metallic bonds around the vacancies, while the magnetization induced by V{sub MoS6} can be effectively manipulated by equibiaxial strain due to the change of Mo–Mo metallic bonds around V{sub MoS6} under strains.

  16. Structure and electronic properties of Cu nanoclusters supported on Mo2C(001) and MoC(001) surfaces

    SciTech Connect (OSTI)

    Posada-Pérez, Sergio; Viñes, Francesc; Rodríguez, José A.; Illas, Francesc

    2015-09-15

    In this study, the atomic structure and electronic properties of Cun nanoclusters (n = 4, 6, 7, and 10) supported on cubic nonpolar δ-MoC(001) and orthorhombic C- or Mo-terminated polar β-Mo2C(001) surfaces have been investigated by means of periodic density functional theory based calculations. The electronic properties have been analyzed by means of the density of states, Bader charges, and electron localization function plots. The Cu nanoparticles supported on β-Mo2C(001), either Mo- or C-terminated, tend to present a two-dimensional structure whereas a three-dimensional geometry is preferred when supported on δ-MoC(001), indicating that the Mo:C ratio and the surface polarity play a key role determining the structure of supported clusters. Nevertheless, calculations also reveal important differences between the C- and Mo-terminated β-Mo2C(001) supports to the point that supported Cu particles exhibit different charge states, which opens a way to control the reactivity of these potential catalysts.

  17. Structure and electronic properties of Cu nanoclusters supported on Mo{sub 2}C(001) and MoC(001) surfaces

    SciTech Connect (OSTI)

    Posada-Pérez, Sergio; Viñes, Francesc; Illas, Francesc

    2015-09-21

    The atomic structure and electronic properties of Cu{sub n} nanoclusters (n = 4, 6, 7, and 10) supported on cubic nonpolar δ-MoC(001) and orthorhombic C- or Mo-terminated polar β-Mo{sub 2} C(001) surfaces have been investigated by means of periodic density functional theory based calculations. The electronic properties have been analyzed by means of the density of states, Bader charges, and electron localization function plots. The Cu nanoparticles supported on β-Mo{sub 2} C(001), either Mo- or C-terminated, tend to present a two-dimensional structure whereas a three-dimensional geometry is preferred when supported on δ-MoC(001), indicating that the Mo:C ratio and the surface polarity play a key role determining the structure of supported clusters. Nevertheless, calculations also reveal important differences between the C- and Mo-terminated β-Mo{sub 2} C(001) supports to the point that supported Cu particles exhibit different charge states, which opens a way to control the reactivity of these potential catalysts.

  18. Thermal transport properties of metal/MoS{sub 2} interfaces from first principles

    SciTech Connect (OSTI)

    Mao, Rui; Kong, Byoung Don; Kim, Ki Wook, E-mail: kwk@ncsu.edu [Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, North Carolina 27695-7911 (United States)

    2014-07-21

    Thermal transport properties at the metal/MoS{sub 2} interfaces are analyzed by using an atomistic phonon transport model based on the Landauer formalism and first-principles calculations. The considered structures include chemisorbed Sc(0001)/MoS{sub 2} and Ru(0001)/MoS{sub 2}, physisorbed Au(111)/MoS{sub 2}, as well as Pd(111)/MoS{sub 2} with intermediate characteristics. Calculated results illustrate a distinctive dependence of thermal transfer on the details of interfacial microstructures. More specifically, the chemisorbed case with a stronger bonding exhibits a generally smaller interfacial thermal resistance than the physisorbed. Comparison between metal/MoS{sub 2} and metal/graphene systems suggests that metal/MoS{sub 2} is significantly more resistive. Further examination of lattice dynamics identifies the presence of multiple distinct atomic planes and bonding patterns at the interface as the key origins of the observed large thermal resistance.

  19. MoS2 Heterojunctions by Thickness Modulation

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

    Tosun, Mahmut; Fu, Deyi; Desai, Sujay B.; Ko, Changhyun; Seuk Kang, Jeong; Lien, Der-Hsien; Najmzadeh, Mohammad; Tongay, Sefaattin; Wu, Junqiao; Javey, Ali

    2015-06-30

    In this work, we report lateral heterojunction formation in as-exfoliated MoS2 flakes by thickness modulation. Kelvin probe force microscopy is used to map the surface potential at the monolayer-multilayer heterojunction, and consequently the conduction band offset is extracted. Scanning photocurrent microscopy is performed to investigate the spatial photocurrent response along the length of the device including the source and the drain contacts as well as the monolayer-multilayer junction. The peak photocurrent is measured at the monolayer-multilayer interface, which is attributed to the formation of a type-I heterojunction. Finally, the work presents experimental and theoretical understanding of the band alignment andmore » photoresponse of thickness modulated MoS2 junctions with important implications for exploring novel optoelectronic devices.« less

  20. Undercooled and rapidly quenched Ni-Mo alloys

    SciTech Connect (OSTI)

    Tewari, S.N.; Glasgow, T.K.

    1986-01-01

    Hypoeutectic, eutectic, and hypereutectic nickel-molybdenum alloys were rapidly solidified by both bulk undercooling and melt spinning techniques. Alloys were undercooled in both electromagnetic levitation and differential thermal analysis equipment. The rate of recalescence depended upon the degree of initial undercooling and the nature (faceted or nonfaceted) of the primary nucleating phase. Alloy melts were observed to undercool more in the presence of primary Beta (NiMo intermetallic) phase than in gamma (fcc solid solution) phase. Melt spinning resulted in an extension of molybdenum solid solubility in gamma nickel, from 28 to 37.5 at % Mo. Although the microstructures observed by undercooling and melt spinning were similar the microsegregation pattern across the gamma dendries was different. The range of microstructures evolved was analyzed in terms of the nature of the primary phase to nucleate, its subsequent dendritic growth, coarsening and fragmentation, and final solidification of interfenderitic liquid.

  1. Development of uranium metal targets for {sup 99}Mo production

    SciTech Connect (OSTI)

    Wiencek, T.C.; Hofman, G.L.

    1993-10-01

    A substantial amount of high enriched uranium (HEU) is used for the production of medical-grade {sup 99}Mo. Promising methods of producing irradiation targets are being developed and may lead to the reduction or elimination of this HEU use. To substitute low enriched uranium (LEU) for HEU in the production of {sup 99}Mo, the target material may be changed to uranium metal foil. Methods of fabrication are being developed to simplify assembly and disassembly of the targets. Removal of the uranium foil after irradiation without dissolution of the cladding is a primary goal in order to reduce the amount of liquid radioactive waste material produced in the process. Proof-of-concept targets have been fabricated. Destructive testing indicates that acceptable contact between the uranium foil and the cladding can be achieved. Thermal annealing tests, which simulate the cladding/uranium diffusion conditions during irradiation, are underway. Plans are being made to irradiate test targets.

  2. IRRADIATION PERFORMANCE OF U-Mo MONOLITHIC FUEL

    SciTech Connect (OSTI)

    M.K. Meyer; J. Gan; J.-F. Jue; D.D. Keiser; E. Perez; A. Robinson; D.M. Wachs; N. Woolstenhulme; G.L. Hofman; Y.-S. Kim

    2014-04-01

    High-performance research reactors require fuel that operates at high specific power to high fission density, but at relatively low temperatures. Research reactor fuels are designed for efficient heat rejection, and are composed of assemblies of thin-plates clad in aluminum alloy. The development of low-enriched fuels to replace high-enriched fuels for these reactors requires a substantially increased uranium density in the fuel to offset the decrease in enrichment. Very few fuel phases have been identified that have the required combination of very-high uranium density and stable fuel behavior at high burnup. UMo alloys represent the best known tradeoff in these properties. Testing of aluminum matrix U-Mo aluminum matrix dispersion fuel revealed a pattern of breakaway swelling behavior at intermediate burnup, related to the formation of a molybdenum stabilized high aluminum intermetallic phase that forms during irradiation. In the case of monolithic fuel, this issue was addressed by eliminating, as much as possible, the interfacial area between U-Mo and aluminum. Based on scoping irradiation test data, a fuel plate system composed of solid U-10Mo fuel meat, a zirconium diffusion barrier, and Al6061 cladding was selected for development. Developmental testing of this fuel system indicates that it meets core criteria for fuel qualification, including stable and predictable swelling behavior, mechanical integrity to high burnup, and geometric stability. In addition, the fuel exhibits robust behavior during power-cooling mismatch events under irradiation at high power.

  3. Terrace-like morphology of the boundary created through basal-prismatic transformation in magnesium

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

    Liu, Bo -Yu; Wan, Liang; Wang, Jian; Ma, Evan; Shan, Zhi -Wei

    2015-01-24

    Here, the boundaries created through basal-prismatic transformation in submicron-sized single crystal magnesium have been investigated systematically using in situ transmission electron microscopy. We found that these boundaries not only deviated significantly from the twin plane associated with {101¯2} twin, but also possessed a non-planar morphology. After the sample was thinned to be less than 90 nm, aberration-corrected scanning transmission electron microscopy observation found that the basic components of these boundaries are actually terrace-like basal-prismatic interfaces.

  4. A systematic multiscale modeling and experimental approach to protect grain boundaries in magnesium alloys from corrosion

    SciTech Connect (OSTI)

    Horstemeyer, Mark R.; Chaudhuri, Santanu

    2015-09-30

    A multiscale modeling Internal State Variable (ISV) constitutive model was developed that captures the fundamental structure-property relationships. The macroscale ISV model used lower length scale simulations (Butler-Volmer and Electronics Structures results) in order to inform the ISVs at the macroscale. The chemomechanical ISV model was calibrated and validated from experiments with magnesium (Mg) alloys that were investigated under corrosive environments coupled with experimental electrochemical studies. Because the ISV chemomechanical model is physically based, it can be used for other material systems to predict corrosion behavior. As such, others can use the chemomechanical model for analyzing corrosion effects on their designs.

  5. High voltage rechargeable magnesium batteries having a non-aqueous electrolyte

    DOE Patents [OSTI]

    Doe, Robert Ellis; Lane, George Hamilton; Jilek, Robert E.; Hwang, Jaehee

    2016-03-22

    A rechargable magnesium battery having an non-aqueous electrolyte is provided. The properties of the electrolyte include high conductivity, high Coulombic efficiency, and an electrochemical window that can exceed 3.5 V vs. Mg/Mg.sup.+2. The use of the electrolyte promotes the electrochemical deposition and dissolution of Mg without the use of any Grignard reagents, other organometallic materials, tetraphenyl borate, or tetrachloroaluminate derived anions. Other Mg-containing electrolyte systems that are expected to be suitable for use in secondary batteries are also described.

  6. Orientation influence on grain size-effects in ultrafine-grained magnesium

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

    Fan, Haidong; Aubry, Sylvie; Arsenlis, A.; El-Awady, Jaafar

    2014-11-08

    The mechanical behavior of ultrafine-grained magnesium was studied by discrete dislocation dynamics (DDD) simulations. Our results show basal slip yields a strong size effect, while prismatic and pyramidal slips produce a weak one. We developed a new size-strength model that considers dislocation transmission across grain boundaries. Good agreement between this model, current DDD simulations and previous experiments is observed. These results reveal that the grain size effect depends on 3 factors: Peierls stress, dislocation source strength and grain boundary strength.

  7. Single Phase Melt Processed Powellite (Ba,Ca) MoO{sub 4} For The Immobilization Of Mo-Rich Nuclear Waste

    SciTech Connect (OSTI)

    Brinkman, Kyle; Marra, James; Fox, Kevin; Reppert, Jason; Crum, Jarrod; Tang, Ming

    2012-09-17

    Crystalline and glass composite materials are currently being investigated for the immobilization of combined High Level Waste (HLW) streams resulting from potential commercial fuel reprocessing scenarios. Several of these potential waste streams contain elevated levels of transition metal elements such as molybdenum (Mo). Molybdenum has limited solubility in typical silicate glasses used for nuclear waste immobilization. Under certain chemical and controlled cooling conditions, a powellite (Ba,Ca)MoO{sub 4} crystalline structure can be formed by reaction with alkaline earth elements. In this study, single phase BaMoO{sub 4} and CaMoO{sub 4} were formed from carbonate and oxide precursors demonstrating the viability of Mo incorporation into glass, crystalline or glass composite materials by a melt and crystallization process. X-ray diffraction, photoluminescence, and Raman spectroscopy indicated a long range ordered crystalline structure. In-situ electron irradiation studies indicated that both CaMoO{sub 4} and BaMoO{sub 4} powellite phases exhibit radiation stability up to 1000 years at anticipated doses with a crystalline to amorphous transition observed after 1 X 10{sup 13} Gy. Aqueous durability determined from product consistency tests (PCT) showed low normalized release rates for Ba, Ca, and Mo (<0.05 g/m{sup 2}).

  8. Single phase melt processed powellite (Ba,Ca)MoO4 for the immobilization of Mo-rich nuclear waste

    SciTech Connect (OSTI)

    Brinkman, Kyle; Fox, Kevin M.; Marra, James C.; Reppert, Jason; Crum, Jarrod V.; Tang, Ming

    2012-10-02

    Crystalline and glass composite materials are currently being investigated for the immobilization of combined High Level Waste (HLW) streams resulting from potential commercial fuel reprocessing scenarios. Several of these potential waste streams contain elevated levels of transition metal elements such as molybdenum (Mo). Molybdenum has limited solubility in typical silicate glasses used for nuclear waste immobilization. Under certain chemical and controlled cooling conditions, a powellite (Ba,Ca)MoO4 crystalline structure can be formed by reaction with alkaline earth elements. In this study, single phase BaMoO4 and CaMoO4 were formed from carbonate and oxide precursors demonstrating the viability of Mo incorporation into glass, crystalline or glass composite materials by a melt and crystallization process. X-ray diffraction, photoluminescence, and Raman spectroscopy indicated a long range ordered crystalline structure. In situ electron irradiation studies indicated that both CaMoO4 and BaMoO4 powellite phases exhibit radiation stability up to 1000 years at anticipated doses with a crystalline to amorphous transition observed after 1 x 1013 Gy. Aqueous durability determined from product consistency tests (PCT) showed low normalized release rates for Ba, Ca, and Mo (<0.05 g/m2).

  9. Structure-dielectric properties relationships in copper-substituted magnesium ferrites

    SciTech Connect (OSTI)

    Druc, A.C.; Borhan, A.I.; Nedelcu, G.G.; Leontie, L.; Iordan, A.R.; Palamaru, M.N.

    2013-11-15

    Graphical abstract: - Highlights: • Synthesis of copper substituted magnesium ferrites materials is reported. • A shift from cubic to tetragonal structure starting with x = 0.84 was observed. • The dielectric properties are influenced by Cu-substitution. - Abstract: Nanocrystalline powders of copper-substituted magnesium ferrites with general formula Mg{sub 1−x}Cu{sub x}Fe{sub 2}O{sub 4} (x = 0.00, 0.17, 0.34, 0.50, 0.67, 0.84, 1.00) were prepared for the first time by sol–gel auto-combustion method, using glycine as fuel agent. Solid phase chemical reactions and the occurrence of spinel structure were monitored by using infrared spectroscopy. X-ray diffraction analysis confirmed the spinel single-phase formation. A shift from cubic structure to tetragonal structure starting with x = 0.84 was also observed. Microstructure of the samples was analyzed by scanning electron microscopy and particle size was estimated from the micrographs. Analysis of dielectric properties revealed very low values of dielectric loss at frequencies over 10 MHz.

  10. Manufacture of gradient micro-structures of magnesium alloys using two stage extrusion dies

    SciTech Connect (OSTI)

    Hwang, Yeong-Maw; Huang, Tze-Hui [Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University, No. 70, Lien-Hai Rd., Kaohsiung, 804, Taiwan (China); Alexandrov, Sergei [Institute for Problems in Mechanics, Russian Academy of Sciences, Moscow (Russian Federation); Naimark, Oleg Borisovich [Institute of Continuous Media Mechanics, Russian Academy of Sciences, Perm (Russian Federation); Jeng, Yeau-Ren [Department of Mechanical Engineering and Advanced Institute of Manufacturing with High-tech Innovations, National Chung Cheng University, Ming-Hsiung, Chia-Yi 621, Taiwan (China)

    2013-12-16

    This paper aims to manufacture magnesium alloy metals with gradient micro-structures using hot extrusion process. The extrusion die was designed to have a straight channel part combined with a conical part. Materials pushed through this specially-designed die generate a non-uniform velocity distribution at cross sections inside the die and result in different strain and strain rate distributions. Accordingly, a gradient microstructure product can be obtained. Using the finite element analysis, the forming temperature, effective strain, and effective strain rate distributions at the die exit were firstly discussed for various inclination angles in the conical die. Then, hot extrusion experiments with a two stage die were conducted to obtain magnesium alloy products with gradient micro-structures. The effects of the inclination angle on the grain size distribution at cross sections of the products were also discussed. Using a die of an inclination angle of 15, gradient micro-structures of the grain size decreasing gradually from 17 ?m at the center to 4 ?m at the edge of product were achieved.

  11. Synthesis, deposition and characterization of magnesium hydroxide nanostructures on zeolite 4A

    SciTech Connect (OSTI)

    Koh, Pei-Yoong; Yan, Jing; Ward, Jason; Koros, William J.; Teja, Amyn S.; Xu, Bo

    2011-03-15

    Research highlights: {yields} Reports a simple precipitation-growth method to produce nanostructures of Mg(OH){sub 2} on the surface of zeolite 4A. {yields} Able to control the growth of the nanostructures by manipulating the experimental procedure. {yields} Able to deposit Mg(OH){sub 2} onto specific sites namely bridging hydroxyl protons (SiOHAl) on the surface of zeolite 4A. -- Abstract: The precipitation and self-assembly of magnesium hydroxide Mg(OH){sub 2} nanopetals on dispersed zeolite 4A particles was investigated. Mg(OH){sub 2}/zeolite nanocomposites were produced from magnesium chloride solutions and characterized via X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Fourier transform infrared analysis (FTIR), and solid state NMR. It was determined that Mg(OH){sub 2} interacted with bridging hydroxyl protons (SiOHAl) on the zeolite surface, but not with silanol or aluminol groups. NMR analysis showed that 13% of the tetrahedral Al sites on the zeolite were converted to octahedral Al. The zeolite structure and crystallinity remained intact after treatment, and no dealumination reactions were detected. This suggests that the deposition-precipitation process at ambient conditions is a facile method for controlling Mg(OH){sub 2} nanostructures on zeolites.

  12. Dynamical behaviors of structural, constrained and free water in calcium- and magnesium-silicate-hydrate gels

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

    Le, Peisi; Fratini, Emiliano; Ito, Kanae; Wang, Zhe; Mamontov, Eugene; Baglioni, Piero; Chen, Sow-Hsin

    2016-01-28

    We present the hypothesis that the mechanical properties of cement pastes depend strongly on their porosities. In a saturated paste, the porosity links to the free water volume after hydration. Structural water, constrained water, and free water have different dynamical behavior. Hence, it should be possible to extract information on pore system by exploiting the water dynamics. With our experiments we investigated the slow dynamics of hydration water confined in calcium- and magnesium-silicate-hydrate (C-S-H and M-S-H) gels using high-resolution quasi-elastic neutron scattering (QENS) technique. C-S-H and M-S-H are the chemical binders present in calcium rich and magnesium rich cements. Wemore » measured three M-S-H samples: pure M-S-H, M-S-H with aluminum-silicate nanotubes (ASN), and M-S-H with carboxyl group functionalized ASN (ASN-COOH). A C-S-H sample with the same water content (i.e. 0.3) is also studied for comparison. We found that structural water in the gels contributes to the elastic component of the QENS spectrum, while constrained water and free water contribute the quasi-elastic component. The quantitative analysis suggests that the three components vary for different samples and indicate the variance in the system porosity, which controls the mechanical properties of cement pastes.« less

  13. Computational Examination of Orientation-Dependent Morphological Evolution during the Electrodeposition and Electrodissolution of Magnesium

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

    DeWitt, S.; Hahn, N.; Zavadil, K.; Thornton, K.

    2015-12-30

    Here a new model of electrodeposition and electrodissolution is developed and applied to the evolution of Mg deposits during anode cycling. The model captures Butler-Volmer kinetics, facet evolution, the spatially varying potential in the electrolyte, and the time-dependent electrolyte concentration. The model utilizes a diffuse interface approach, employing the phase field and smoothed boundary methods. Scanning electron microscope (SEM) images of magnesium deposited on a gold substrate show the formation of faceted deposits, often in the form of hexagonal prisms. Orientation-dependent reaction rate coefficients were parameterized using the experimental SEM images. Three-dimensional simulations of the growth of magnesium deposits yieldmore » deposit morphologies consistent with the experimental results. The simulations predict that the deposits become narrower and taller as the current density increases due to the depletion of the electrolyte concentration near the sides of the deposits. Increasing the distance between the deposits leads to increased depletion of the electrolyte surrounding the deposit. Two models relating the orientation-dependence of the deposition and dissolution reactions are presented. Finally, the morphology of the Mg deposit after one deposition-dissolution cycle is significantly different between the two orientation-dependence models, providing testable predictions that suggest the underlying physical mechanisms governing morphology evolution during deposition and dissolution.« less

  14. Formation of magnesium silicate hydrate (M-S-H) cement pastes using sodium hexametaphosphate

    SciTech Connect (OSTI)

    Zhang, Tingting; Vandeperre, Luc J.; Cheeseman, Christopher R.

    2014-11-15

    Magnesium silicate hydrate (M-S-H) gel is formed by the reaction of brucite with amorphous silica during sulphate attack in concrete and M-S-H is therefore regarded as having limited cementing properties. The aim of this work was to form M-S-H pastes, characterise the hydration reactions and assess the resulting properties. It is shown that M-S-H pastes can be prepared by reacting magnesium oxide (MgO) and silica fume (SF) at low water to solid ratio using sodium hexametaphosphate (NaHMP) as a dispersant. Characterisation of the hydration reactions by x-ray diffraction and thermogravimetric analysis shows that brucite and M-S-H gel are formed and that for samples containing 60 wt.% SF and 40 wt.% MgO all of the brucites react with SF to form M-S-H gel. These M-S-H cement pastes were found to have compressive strengths in excess of 70 MPa.

  15. Design and experimental activities supporting commercial U.S. electron accelerator production of Mo-99

    SciTech Connect (OSTI)

    Dale, Gregory E.; Woloshun, Keith A.; Kelsey IV, Charles T.; Olivas, Eric R.; Holloway, Michael A.; Hurtle, Ken P.; Romero, Frank P.; Dalmas, Dale A.; Chemerisov, Sergey D.; Vandegrift, George F.; Tkac, Peter; Makarashvili, Vakho; Jonah, Charles D.; Harvey, James T.

    2013-04-19

    {sup 99m}Tc, the daughter isotope of {sup 99}Mo, is the most commonly used radioisotope for nuclear medicine in the United States. Under the direction of the National Nuclear Security Administration (NNSA), Los Alamos National Laboratory (LANL) and Argonne National Laboratory (ANL) are partnering with North Star Medical Technologies to demonstrate the viability of large-scale {sup 99}Mo production using electron accelerators. In this process, {sup 99}Mo is produced in an enriched {sup 100}Mo target through the {sup 100}Mo({gamma},n){sup 99}Mo reaction. Five experiments have been performed to date at ANL to demonstrate this process. This paper reviews the current status of these activities, specifically the design and performance of the helium gas target cooling system.

  16. Characterization of modified 9 Cr-1 Mo steel extruded pipe

    SciTech Connect (OSTI)

    Sikka, V.K.; Hart, M.D.

    1985-04-01

    The fabrication of hot-extruded pipe of modified 9 Cr-1 Mo steel at Cameron Iron Works is described. The report also deals with the tempering response; tensile, Charpy impact, and creep properties; and microstructure of the hot-extruded pipe. The tensile properties of the pipe are compared with the average and average -1.65 standard error of estimate curves for various product forms of several commercial heats of this alloy. The creep-rupture properties are compared with the average curve for various product forms of the commercial heats.

  17. Greenfield Alternative Study LEU-Mo Fuel Fabrication Facility

    SciTech Connect (OSTI)

    Washington Division of URS

    2008-07-01

    This report provides the initial “first look” of the design of the Greenfield Alternative of the Fuel Fabrication Capability (FFC); a facility to be built at a Greenfield DOE National Laboratory site. The FFC is designed to fabricate LEU-Mo monolithic fuel for the 5 US High Performance Research Reactors (HPRRs). This report provides a pre-conceptual design of the site, facility, process and equipment systems of the FFC; along with a preliminary hazards evaluation, risk assessment as well as the ROM cost and schedule estimate.

  18. Recovery of Mo/Si multilayer coated optical substrates

    DOE Patents [OSTI]

    Baker, S.L.; Vernon, S.P.; Stearns, D.G.

    1997-12-16

    Mo/Si multilayers are removed from superpolished ZERODUR and fused silica substrates with a dry etching process that, under suitable processing conditions, produces negligible change in either the substrate surface figure or surface roughness. The two step dry etching process removes SiO{sub 2} overlayer with a fluroine-containing gas and then moves molybdenum and silicon multilayers with a chlorine-containing gas. Full recovery of the initial normal incidence extreme ultra-violet (EUV) reflectance response has been demonstrated on reprocessed substrates. 5 figs.

  19. Recovery of Mo/Si multilayer coated optical substrates

    DOE Patents [OSTI]

    Baker, Sherry L.; Vernon, Stephen P.; Stearns, Daniel G.

    1997-12-16

    Mo/Si multilayers are removed from superpolished ZERODUR and fused silica substrates with a dry etching process that, under suitable processing conditions, produces negligible change in either the substrate surface figure or surface roughness. The two step dry etching process removes SiO.sub.2 overlayer with a fluroine-containing gas and then moves molybdenum and silicon multilayers with a chlorine-containing gas. Full recovery of the initial normal incidence extreme ultra-violet (EUV) reflectance response has been demonstrated on reprocessed substrates.

  20. Microsoft Word - chapter FeCrMo_ver2.doc

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

    Reference on Hydrogen Compatibility of Materials Low-Alloy Ferritic Steels: Tempered Fe-Cr-Mo Alloys (code 1211) Prepared by: B.P. Somerday, Sandia National Laboratories Editors C. San Marchi B.P. Somerday Sandia National Laboratories This report may be updated and revised periodically in response to the needs of the technical community; up-to-date versions can be requested from the editors at the address given below or downloaded at http://www.ca.sandia.gov/matlsTechRef/ . The success of this

  1. Synthesis of molybdenum disulfide (MoS{sub 2}) for lithium ion battery applications

    SciTech Connect (OSTI)

    Feng Chuanqi; Ma Jun; Li Hua; Zeng Rong; Guo Zaiping; Liu Huakun

    2009-09-15

    This paper reports the use of a rheological phase reaction method for preparing MoS{sub 2} nanoflakes. The characterization by powder X-ray diffraction indicated that MoS{sub 2} had been formed. High resolution electron microscopy observation revealed that the as-prepared MoS{sub 2} nanoflakes had started to curve and partly form MoS{sub 2} nanotubes. The lithium intercalation/de-intercalation behavior of as-prepared MoS{sub 2} nanoflake electrode was also investigated. It was found that the MoS{sub 2} nanoflake electrode exhibited higher specific capacity, with very high cycling stability, compared to MoS{sub 2} nanoparticle electrode. The possible reasons for the high electrochemical performance of the nanoflakes electrodes are also discussed. The outstanding electrochemical properties of MoS{sub 2} nanoflakes obtained by this method make it possible for MoS{sub 2} to be used as a promising anode material.

  2. Acquisition Guide Chapter 7.3:Acquisition Planning in the M&O Environment

    Broader source: Energy.gov [DOE]

    Acquisition Letter 2013-03, Acquisition Planning Considerations for M&O Contracts, has been moved to the Acquisition Guide as chapter (7.3).

  3. First-principles characterization of potassium intercalation in the hexagonal 2H-MoS2

    SciTech Connect (OSTI)

    Andersen, Amity; Kathmann, Shawn M.; Lilga, Michael A.; Albrecht, Karl O.; Hallen, Richard T.; Mei, Donghai

    2012-01-12

    Periodic density functional theory calculations were performed to study the structural and electronic properties of potassium intercalated into hexagonal MoS{sub 2} (2H-MoS{sub 2}). Metallic potassium (K) atoms are incrementally loaded in the hexagonal sites of the interstitial spaces between MoS2 sheets of the 2H-MoS{sub 2} bulk structure generating 2H-KxMoS2 (0.125 {<=} x {<=} 1.0) structures. To accommodate the potassium atoms, the interstitial spacing c parameter in the 2H-MoS{sub 2} bulk expands from 12.816 {angstrom} in 2H-MoS{sub 2} to 16.086 {angstrom} in 2H-K{sub 0.125}MoS{sub 2}. The second lowest potassium loading concentration (K{sub 0.25}MoS{sub 2}) results in the largest interstitial spacing expansion (to c = 16.726 {angstrom}). Our calculations show that there is a small gradual contraction of the interstitial spacing as the potassium loading increases with c = 14.839 {angstrom} for KMoS{sub 2}. This interstitial contraction is correlated with an in-plane expansion of the MoS{sub 2} sheets, which is in good agreement with experimental X-ray diffraction (XRD) measurements. The electronic analysis shows that potassium readily donates its 4s electron to the conduction band of the 2H-K{sub x}MoS{sub 2}, and is largely ionic in character. As a result of the electron donation, the 2H-K{sub x}MoS{sub 2} system changes from a semiconductor to a more metallic system with increasing potassium intercalation. For loadings 0.25 {<=} x {<=} 0.625, triangular Mo-Mo-Mo moieties are prominent and tend to form rhombitrihexagonal motifs. Intercalation of H{sub 2}O molecules that solvate the K atoms is likely to occur in catalytic conditions. The inclusion of two H{sub 2}O molecules per K atom in the K{sub 0.25}MoS{sub 2} structure shows good agreement with XRD measurements.

  4. Experimental activities supporting commercial U.S. accelerator production of 99-Mo

    SciTech Connect (OSTI)

    Dale, Gregory E; Chemerisov, Sergey D; Vandegrift, George F

    2010-01-01

    {sup 99m}Tc, the daughter product of {sup 99}Mo, is the most commonly used radioisotope for nuclear medicine in the U.S. Experiments are being performed at Los Alamos National Laboratory and Argonne National Laboratory to demonstrate production of {sup 99}Mo using accelerators. The {sup 100}Mo({gamma},n){sup 99}Mo reaction in an enriched {sup 100}Mo target is currently under investigation. Three scaled low-power production experiments using a 20-MeV electron linac at Argonne have been performed to date. Two of these experiments used natural Mo targets and produced a total of 613 {mu}C of {sup 99}Mo. The third experiment used an enriched {sup 100}Mo target and produced 10.5 mCi of {sup 99}Mo. Following irradiation the targets were dissolved and the low specific activity solution was processed through an ARSII generator from NorthStar Medical Radioisotopes. Yields of {sup 99m}Tc >95% have been observed.

  5. Defects Engineered Monolayer MoS2 for Improved Hydrogen Evolution...

    Office of Scientific and Technical Information (OSTI)

    Hydrogen Evolution Reaction This content will become publicly available on January 13, 2017 Prev Next Title: Defects Engineered Monolayer MoS2 for Improved Hydrogen ...

  6. Conceptual design of a new homogeneous reactor for medical radioisotope Mo-99/Tc-99m production

    SciTech Connect (OSTI)

    Liem, Peng Hong; Tran, Hoai Nam; Sembiring, Tagor Malem; Arbie, Bakri

    2014-09-30

    To partly solve the global and regional shortages of Mo-99 supply, a conceptual design of a nitrate-fuel-solution based homogeneous reactor dedicated for Mo-99/Tc-99m medical radioisotope production is proposed. The modified LEU Cintichem process for Mo-99 extraction which has been licensed and demonstrated commercially for decades by BATAN is taken into account as a key design consideration. The design characteristics and main parameters are identified and the advantageous aspects are shown by comparing with the BATAN's existing Mo-99 supply chain which uses a heterogeneous reactor (RSG GAS multipurpose reactor)

  7. Mechanically Activated Combustion Synthesis of MoSi2-Based Composites

    SciTech Connect (OSTI)

    Shafirovich, Evgeny

    2015-09-30

    The thermal efficiency of gas-turbine power plants could be dramatically increased by the development of new structural materials based on molybdenum silicides and borosilicides, which can operate at temperatures higher than 1300 °C with no need for cooling. A major challenge, however, is to simultaneously achieve high oxidation resistance and acceptable mechanical properties at high temperatures. One approach is based on the fabrication of MoSi2-Mo5Si3 composites that combine high oxidation resistance of MoSi2 and good mechanical properties of Mo5Si3. Another approach involves the addition of boron to Mo-rich silicides for improving their oxidation resistance through the formation of a borosilicate surface layer. In particular, materials based on Mo5SiB2 phase are promising materials that offer favorable combinations of high temperature mechanical properties and oxidation resistance. However, the synthesis of Mo-Si-B multi-phase alloys is difficult because of their extremely high melting temperatures. Mechanical alloying has been considered as a promising method, but it requires long milling times, leading to large energy consumption and contamination of the product by grinding media. In the reported work, MoSi2-Mo5Si3 composites and several materials based on Mo5SiB2 phase have been obtained by mechanically activated self-propagating high-temperature synthesis (MASHS). Short-term milling of Mo/Si mixture in a planetary mill has enabled a self-sustained propagation of the combustion front over the mixture pellet, leading to the formation of MoSi2-T1 composites. Combustion of Mo/Si/B mixtures for the formation of T2 phase becomes possible if the composition is designed for the addition of more exothermic reactions leading to the formation of MoB, TiC, or TiB2. Upon ignition, Mo/Si/B and Mo/Si/B/Ti mixtures exhibited spin combustion, but the products were porous, contained undesired secondary phases, and had low oxidation resistance. It has been shown that use of

  8. Magnesium Projects

    Broader source: Energy.gov [DOE]

    2010 DOE Vehicle Technologies and Hydrogen Programs Annual Merit Review and Peer Evaluation Meeting, June 7-11, 2010 -- Washington D.C.

  9. Characterization of U-Mo Foils for AFIP-7

    SciTech Connect (OSTI)

    Edwards, Danny J.; Ermi, Ruby M.; Schemer-Kohrn, Alan L.; Overman, Nicole R.; Henager, Charles H.; Burkes, Douglas; Senor, David J.

    2012-11-07

    Twelve AFIP in-process foil samples, fabricated by either Y-12 or LANL, were shipped from LANL to PNNL for potential characterization using optical and scanning electron microscopy techniques. Of these twelve, nine different conditions were examined to one degree or another using both techniques. For this report a complete description of the results are provided for one archive foil from each source of material, and one unirradiated piece of a foil of each source that was irradiated in the Advanced Test Reactor. Additional data from two other LANL conditions are summarized in very brief form in an appendix. The characterization revealed that all four characterized conditions contained a cold worked microstructure to different degrees. The Y-12 foils exhibited a higher degree of cold working compared to the LANL foils, as evidenced by the highly elongated and obscure U-Mo grain structure present in each foil. The longitudinal orientations for both of the Y-12 foils possesses a highly laminar appearance with such a distorted grain structure that it was very difficult to even offer a range of grain sizes. The U-Mo grain structure of the LANL foils, by comparison, consisted of a more easily discernible grain structure with a mix of equiaxed and elongated grains. Both materials have an inhomogenous grain structure in that all of the characterized foils possess abnormally coarse grains.

  10. Evaluation of Mo catalyst precursors for hydrotreating coal derived liquids

    SciTech Connect (OSTI)

    Anderson, R.K.; Gibb, D.R.; Kimber, G.M.; Derbyshire, F.J.

    1997-04-01

    Numerous studies have examined the use of dispersed catalysts for promoting the dissolution of coal and upgrading high-boiling and residual liquids. Catalysts have been added in various forms, including oil soluble organometallics and carbonyls, with industrial interest for application to a spectrum of residual feedstocks, and demonstration in coal liquefaction at the pilot plant scale. Dispersed catalysts offer certain advantages over supported catalysts for hydroprocessing such feedstocks. Because of their large molecular size, many of the feed constituents cannot access the internal pore structure of supported catalysts, and hence upgrading must proceed by an indirect process, probably involving H-transfer via lower molecular weight species. Another major deficiency of supported catalysts is their susceptibility to deactivation by reactions which cause the deposition of carbon and metals. Dispersed catalysts can overcome the first of these obstacles and may be less susceptible to deactivation. At the same time, there are also difficulties in the utilization of dispersed catalysts. These include: attaining and maintaining adequate dispersion; and converting the precursor to the active phase. Moreover, the effective catalyst metals, such as Mo, are expensive and their application is only economically viable if they can be used at very low concentrations or efficiently recycled. In direct coal liquefaction, the presence of mineral matter and undissolved coal in the products of coal solubilization mean that a solids separation step is necessary and, inevitably, catalyst will be removed with the reject stream. This program studied the effectiveness of dispersed Mo catalysts for hydroprocessing solids-free residual coal liquids.

  11. Suspension- and current-deposit reservoirs in the Delaware basin: Trends and cycles in siltstones of the Permian Bone Spring Limestone

    SciTech Connect (OSTI)

    Lorenz, J.C. ); Brooks, L.L. )

    1990-05-01

    Cores show that siltstone to very fine-grained sandstone oil reservoirs within the Permian Bone Spring Limestone are composed of submillimeter- to centimeter-thick sedimentation laminae. Blanketing of small-scale topography suggests that the laminae were deposited over wide areas as sediment settled vertical to the sea floor. Superimposed on the event laminae, were (1) background sedimentation of dolomitic, organic-rich, mudstone, (2) invertebrate burrowing, and (3) reworking by gentle bottom currents. Currents produced wispy ripply bedding and starved ripple forms that were draped by later deposits. Paleoflow was subparallel to the basin margin. Several sedimentation patterns occur within the formation. Three clastic intervals 25-50-m thick are interbedded with dolomitic mudstones of similar thickness. The clastic intervals are composed of three to six siltstone beds, each up to 25-m thick. Upsection within the beds increases in event-laminae, thickness, bioturbation, and current reworking. Other reports have suggested that these are turbidite-fan deposits, but locally, paleocurrent orientations and the lack of diagnostic assemblages and sequences of sedimentary structures argue against this interpretation. Rather, some of these deposits compare favorably with the few existing sedimentologic descriptions of Quaternary dust storm deposition in marine basins. The siltstone beds may also record deflation of the exposed adjacent shelf during lowered sea level. Very fine grain size and extensive carbonate cementation produce 5-10 pd permeability and 4-15% porosity. Sedimentary laminations cause significantly reduced vertical permeability where they are not disrupted by bioturbation, but permeability may be enhanced by natural fractures. Some reservoir thickenings are attributed to the formation of giant ripples by bottom currents, dictating a different exploration rationale than the turbidite-fan model.

  12. Solidification, growth mechanisms, and associated properties of Al-Si and magnesium lightweight casting alloys

    SciTech Connect (OSTI)

    Hosch, Timothy

    2010-01-01

    Continually rising energy prices have inspired increased interest in weight reduction in the automotive and aerospace industries, opening the door for the widespread use and development of lightweight structural materials. Chief among these materials are cast Al-Si and magnesium-based alloys. Utilization of Al-Si alloys depends on obtaining a modified fibrous microstructure in lieu of the intrinsic flake structure, a process which is incompletely understood. The local solidification conditions, mechanisms, and tensile properties associated with the flake to fiber growth mode transition in Al-Si eutectic alloys are investigated here using bridgman type gradient-zone directional solidification. Resulting microstructures are examined through quantitative image analysis of two-dimensional sections and observation of deep-etched sections showing three-dimensional microstructural features. The transition was found to occur in two stages: an initial stage dominated by in-plane plate breakup and rod formation within the plane of the plate, and a second stage where the onset of out-of-plane silicon rod growth leads to the formation of an irregular fibrous structure. Several microstructural parameters were investigated in an attempt to quantify this transition, and it was found that the particle aspect ratio is effective in objectively identifying the onset and completion velocity of the flake to fiber transition. The appearance of intricate out-of-plane silicon instability formations was investigated by adapting a perturbed-interface stability analysis to the Al-Si system. Measurements of silicon equilibrium shape particles provided an estimate of the anisotropy of the solid Si/liquid Al-Si system and incorporation of this silicon anisotropy into the model was found to improve prediction of the instability length scale. Magnesium alloys share many of the benefits of Al-Si alloys, with the added benefit of a 1/3 lower density and increased machinability. Magnesium castings

  13. Evaluation of the Magnesium Hydroxide Treatment Process for Stabilizing PFP Plutonium/Nitric Acid Solutions

    SciTech Connect (OSTI)

    Gerber, Mark A.; Schmidt, Andrew J.; Delegard, Calvin H.; Silvers, Kurt L.; Baker, Aaron B.; Gano, Susan R.; Thornton, Brenda M.

    2000-09-28

    This document summarizes an evaluation of the magnesium hydroxide [Mg(OH)2] process to be used at the Hanford Plutonium Finishing Plant (PFP) for stabilizing plutonium/nitric acid solutions to meet the goal of stabilizing the plutonium in an oxide form suitable for storage under DOE-STD-3013-99. During the treatment process, nitric acid solutions bearing plutonium nitrate are neutralized with Mg(OH)2 in an air sparge reactor. The resulting slurry, containing plutonium hydroxide, is filtered and calcined. The process evaluation included a literature review and extensive laboratory- and bench-scale testing. The testing was conducted using cerium as a surrogate for plutonium to identify and quantify the effects of key processing variables on processing time (primarily neutralization and filtration time) and calcined product properties.

  14. Characterizing the boundary lateral to the shear direction of deformation twins in magnesium

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

    Liu, Y.; Li, N.; Shao, S.; Gong, M.; Wang, J.; McCabe, R. J.; Jiang, Y.; Tomé, C. N.

    2016-06-01

    The three-dimensional nature of twins, especially the atomic structures and motion mechanisms of the boundary lateral to the shear direction of the twin, has never been characterized at the atomic level, because such boundary is, in principle, crystallographically unobservable. We thus refer to it here as the dark side of the twin. Here, using high-resolution transmission electron microscopy and atomistic simulations, we characterize the dark side of {101⁻2} deformation twins in magnesium. It is found that the dark side is serrated and comprised of {101⁻2} coherent twin boundaries and semi-coherent twist prismatic–prismatic {211⁻0} boundaries that control twin growth. The conclusionsmore » we find in this work apply to the same twin mode in other hexagonal close-packed materials, and the conceptual ideas discussed here should hold for all twin modes in crystalline materials.« less

  15. Tension-compression-tension tertiary twins in coarse-grained polycrystalline pure magnesium at room temperature

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

    Yu, Qin; Jiang, Yanyao; Wang, Jian

    2015-04-07

    Using electron backscatter diffraction, the microstructural features of tension–compression–tension (T–C–T) tertiary twins are studied in coarse-grained pure polycrystalline magnesium subjected to monotonic compression along the extrusion direction in ambient air. T–C–T tertiary twins are developed due to the formation of a compression–tension double twin inside a primary tension twin. All the observed T–C–T twin variants are of TiCjTj type. TiCi+1Ti+1 (or TiCi–1Ti–1) variants are observed more frequently than TiCi+2Ti+2 (or TiCi–2Ti–2) variants. Moreover, the number of tertiary twin lamellae increases with the applied compressive strain.

  16. THE HYDROLYSIS AND OXIDATION BEHAVIOR OF LITHIUM BOROHYDRIDE AND MAGNESIUM HYDRIDE DETERMINED BY CALORIMETRY

    SciTech Connect (OSTI)

    Brinkman, K; Donald Anton, D; Joshua Gray, J; Bruce Hardy, B

    2008-03-13

    Lithium borohydride, magnesium hydride and the 2:1 'destabilized' ball milled mixtures (2LiBH{sub 4}:MgH{sub 2}) underwent liquid phase hydrolysis, gas phase hydrolysis and air oxidation reactions monitored by isothermal calorimetry. The experimentally determined heats of reaction and resulting products were compared with those theoretically predicted using thermodynamic databases. Results showed a discrepancy between the predicted and observed hydrolysis and oxidation products due to both kinetic limitations and to the significant amorphous character of observed reaction products. Gas phase and liquid phase hydrolysis were the dominant reactions in 2LiBH{sub 4}:MgH{sub 2} with approximately the same total energy release and reaction products; liquid phase hydrolysis displayed the maximum heat flow for likely environmental exposure with a peak energy release of 6 (mW/mg).

  17. Analysis of the potential for new automotive uses of wrought magnesium

    SciTech Connect (OSTI)

    Gaines, L.; Cuenca, R.; Wu, S.; Stodolsky, F.

    1996-02-01

    The Center for Transportation Research at Argonne National Laboratory has performed a study for the Lightweight Materials Program within the US Department of Energy`s Office of Transportation Materials to evaluate the suitability of wrought magnesium and its alloys to replace steel or aluminum for automotive structural and sheet applications. Vehicle weight reduction is one of the major means available for improving automotive fuel efficiency. Although high-strength steels, Al, and polymers are already being used to achieve significant weight reductions, substantial additional weight reductions could be achieved by increased use of Mg (whose density is less than one-fourth that of steel and only two-thirds that of Al). This study shows that Mg sheet could be used in automotive body nonstructural and semistructural applications, whereas extrusions could be used in such structural applications as spaceframes. The primary barrier to such uses of wrought Mg is high cost.

  18. Individual and combined effects of chloride, sulfate, and magnesium ions on hydrated Portland-cement paste

    SciTech Connect (OSTI)

    Poole, T.S.; Wakeley, L.D.; Young, C.L.

    1994-03-01

    Ground water with a high concentration of magnesium ion is known to cause deterioration to portland cement concretes. A proposed mechanism for this deterioration process published previously involves an approximate 1:1 replacement of Ca ions by Mg ions in the crystalline phases of hydrated cement. The current study was undertaken to determine which ions, among magnesium, chloride, and sulfate, cause deterioration; whether their deleterious action is individual or interdependent; and to relate this mechanism of deterioration to the outlook for a 100-yr service life of concretes used in mass placements at the Waste Isolation Pilot Plant. Loss of Ca ion by cement pastes was found to be strongly related to the concentration of Mg ion in simulated ground-water solutions in which the paste samples were aged. This was true of both salt- containing and conventional cement pastes. No other ion in the solutions exerted a strong effect on Ca loss. Ca ion left first from calcium hydroxide in the pastes, depleting all calcium hydroxide by 60 days. Some calcium silicate hydrate remained even after 90 days in the solutions with the highest concentration of Mg ion, while the paste samples deteriorated noticeably. The results indicated a mechanism that involves dissolution of Ca phases and transport of Ca ions to the surface of the sample, followed by formation of Mg-bearing phases at this reaction surface rather than directly by substitution within the microstructure of hydrated cement. Given that calcium hydroxide and calcium silicate hydrate are the principal strength-giving phases of hydrated cement, this mechanism indicates the likelihood of significant loss of integrity of a concrete exposed to Mg-bearing ground water at the WIPP. The rate of deterioration ultimately will depend on Mg-ion concentration, the microstructure materials of the concrete exposed to that groundwater, and the availability of brine.

  19. Broadband ultra-high transmission of terahertz radiation through monolayer MoS{sub 2}

    SciTech Connect (OSTI)

    Deng, Xue-Yong; Deng, Xin-Hua; Su, Fu-Hai; Liu, Nian-Hua; Liu, Jiang-Tao

    2015-12-14

    In this study, the terahertz (THz) absorption and transmission of monolayer MoS{sub 2} with different carrier concentrations were investigated theoretically. The calculation shows that the THz absorption of monolayer MoS{sub 2} is very low even under high carrier concentrations and large incident angles. The sum of reflection and absorption losses of monolayer MoS{sub 2} is lower than that of graphene by one to three orders of magnitude. The transmission of monolayer MoS{sub 2} is higher than that of two-dimensional electron gases in traditional GaAs and InAs. The field-effect tube structure formed by monolayer MoS{sub 2}-insulation-layer-graphene is also studied. The THz absorption of graphene can reach saturation under low voltage by tuning the voltage between MoS{sub 2} and graphene layers in the structure. The maximum THz absorption of monolayer MoS{sub 2} is approximately 5%. Thus, monolayer MoS{sub 2} is a promising candidate for THz transparent electrodes.

  20. A Solution-Based Approach for Mo-99 Production: Considerations for Nitrate versus Sulfate Media

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

    Youker, Amanda J.; Chemerisov, Sergey D.; Kalensky, Michael; Tkac, Peter; Bowers, Delbert L.; Vandegrift, George F.

    2013-01-01

    Molybdenum-99 is the parent of Technetium-99m, which is used in nearly 80% of all nuclear medicine procedures. The medical community has been plagued by Mo-99 shortages due to aging reactors, such as the NRU (National Research Universal) reactor in Canada. There are currently no US producers of Mo-99, and NRU is scheduled for shutdown in 2016, which means that another Mo-99 shortage is imminent unless a potential domestic Mo-99 producer fills the void. Argonne National Laboratory is assisting two potential domestic suppliers of Mo-99 by examining the effects of a uranyl nitrate versus a uranyl sulfate target solution configuration onmore » Mo-99 production. Uranyl nitrate solutions are easier to prepare and do not generate detectable amounts of peroxide upon irradiation, but a high radiation field can lead to a large increase in pH, which can lead to the precipitation of fission products and uranyl hydroxides. Uranyl sulfate solutions are more difficult to prepare, and enough peroxide is generated during irradiation to cause precipitation of uranyl peroxide, but this can be prevented by adding a catalyst to the solution. A titania sorbent can be used to recover Mo-99 from a highly concentrated uranyl nitrate or uranyl sulfate solution; however, different approaches must be taken to prevent precipitation during Mo-99 production.« less

  1. New Generation of MoSx Based Solid Lubricant Coatings: Recent Developments and Applications

    SciTech Connect (OSTI)

    Haider, Julfikar; Hashmi, M. S. J.

    2011-01-17

    In recent times, there is a growing interest in applying Molybdenum disulphide (MoS{sub x}) solid lubricant coatings on components to improve the tribological performance (i.e. lower friction coefficient and wear rate). The tribological performance of MoS{sub x} coating is strongly dependent on coating properties and tribological environment. MoS{sub x} coatings are highly successful in certain applications such as in space/vacuum technology, but its effectiveness is questioned in other terrestrial applications such as in cutting tool industry due to its lower hardness and poor oxidation resistance leading to shorter life. In order to circumvent this drawback, the paper identifies that current research is being concentrated on developing MoS{sub x} based coatings using three different approaches: (1) Metal or compound addition in MoS{sub x} coating (2)MoS{sub x} layer on hard coating and (3)MoS{sub x} addition in hard coating matrix. Although the primary objective is same in all three cases, the third approach is considered to be more effective in improving the tribological properties of the coating. Finally, the potential applications of MoS{sub x} based coatings in different industrial sectors have been briefly outlined.

  2. Photo-oxidation method using MoS2 nanocluster materials

    DOE Patents [OSTI]

    Wilcoxon, Jess P.

    2001-01-01

    A method of photo-oxidizing a hydrocarbon compound is provided by dispersing MoS.sub.2 nanoclusters in a solvent containing a hydrocarbon compound contaminant to form a stable solution mixture and irradiating the mixture to photo-oxide the hydrocarbon compound. Hydrocarbon compounds of interest include aromatic hydrocarbon and chlorinated hydrocarbons. MoS.sub.2 nanoclusters with an average diameter less than approximately 10 nanometers are shown to be effective in decomposing potentially toxic aromatic and chlorinated hydrocarbons, such as phenol, pentachlorophenol, chlorinated biphenols, and chloroform, into relatively non-toxic compounds. The irradiation can occur by exposing the MoS.sub.2 nanoclusters and hydrocarbon compound mixture with visible light. The MoS.sub.2 nanoclusters can be introduced to the toxic hydrocarbons as either a MoS.sub.2 solution or deposited on a support material.

  3. Thermal properties of U–Mo alloys irradiated to moderate burnup and power

    SciTech Connect (OSTI)

    Burkes, Douglas E.; Casella, Andrew M.; Casella, Amanda J.; Buck, Edgar C.; Pool, Karl N.; MacFarlan, Paul J.; Edwards, Matthew K.; Smith, Frances N.

    2015-09-01

    A variety of physical and thermal property measurements as a function of temperature and fission density were performed on irradiated U-Mo alloy monolithic fuel samples with a Zr diffusion barrier and clad in aluminum alloy 6061. The U-Mo alloy density, thermal diffusivity, and thermal conductivity are strongly influenced by increasing burnup, mainly as the result of irradiation induced recrystallization and fission gas bubble formation and coalescence. U-Mo chemistry, specifically Mo content, and specific heat capacity was not as sensitive to increasing burnup. Measurements indicated that thermal conductivity of the U-Mo alloy decreased approximately 30% for a fission density of 2.88 × 1021 fissions cm-3 and approximately 45% for a fission density of 4.08 × 1021 fissions cm-3 from unirradiated values at 200 oC. An empirical thermal conductivity degradation model developed previously and summarized here agrees well with the experimental measurements.

  4. Detection of a MoSe{sub 2} secondary phase layer in CZTSe by spectroscopic ellipsometry

    SciTech Connect (OSTI)

    Demircioğlu, Özden; Riedel, Ingo; Gütay, Levent; Mousel, Marina; Redinger, Alex; Rey, Germain; Weiss, Thomas; Siebentritt, Susanne

    2015-11-14

    We demonstrate the application of Spectroscopic Ellipsometry (SE) for identification of secondary phase MoSe{sub 2} in polycrystalline Cu{sub 2}ZnSnSe{sub 4} (CZTSe) samples. A MoSe{sub 2} reference sample was analyzed, and its optical constants (ε{sub 1} and ε{sub 2}) were extracted by SE analysis. This dataset was implemented into an optical model for analyzing SE data from a glass/Mo/CZTSe sample containing MoSe{sub 2} at the back side of the absorber. We present results on the n and k values of CZTSe and show the extraction of the thickness of the secondary phase MoSe{sub 2} layer. Raman spectroscopy and scanning electron microscopy were applied to confirm the SE results.

  5. Synthesis and characterization of model MgO supported catalyst with Pt-Mo interactions.

    SciTech Connect (OSTI)

    Alexeev, O.; Kawi, S.; Gates, B.C. [Univ. of California, Davis, CA (United States)] [Univ. of California, Davis, CA (United States); Shelef, M. [Ford Motor Co., Dearborn, MI (United States)] [Ford Motor Co., Dearborn, MI (United States)

    1996-01-04

    MgO supported platinum and platinum-molybdenum catalysts were prepared from organometallic precursors and charaterized structurally to determine how the nature of the bimetallic precursors and the treatment conditions affected the interaction between the two metals. Samples were prepared from [PtCl{sub 2}(PhCN){sub 2}], [PtCl{sub 2}(PhCN){sub 2}] + [Mo(CO){sub 6}], and [C@Pt[Mo(CO){sub 3}(C{sub 5}H{sub 5})]{sub 2}(PhCN){sub 2}] BC@ characterized by infrared and extended X-ray absorption fine structure (EXAFS) spectroscopies, tranmission electron microscopy, and chemisorption of H{sub 2}, CO, and O{sub 2}. The samples were treated in H{sub 2} at 400{degree}C prior to most of the characterizatons. Incorporation of Mo reduced the chemisorption of CO and of H{sub 2}. EXAFS spectra measured at the Pt L{sub III} edge and at the Mo K edge showed substantial Pt-Mo contributions with a Pt-Mo cordination number of about 2 and an average distance of 2.63 A for the sample prepared from [C@Pt[Mo(CO){sub 3}(C{sub 5}H{sub 5})]{sub 2}(PhCN){sub 2}] BC@. In constract, no significant Pt-Mo contribution was observed for the sample prepared from [PtCl{sub 2}(PhCN){sub 2}]+ [Mo(CO){sub 6}]. Electron micrographs and EXAFS results show that interaction between Pt and Mo ions in the former sample helped to maintain the platinum in a highly dispersed form, with supported platinum clusters being smaller than about 10 A. 53 refs., 9 figs., 9 tabs.

  6. Nitrogenase MoFe protein from Clostridium pasteurianum at 1.08 Å resolution: comparison with the Azotobacter vinelandii MoFe protein

    SciTech Connect (OSTI)

    Zhang, Li-Mei; Morrison, Christine N.; Kaiser, Jens T.; Rees, Douglas C.

    2015-02-01

    Determination of the nitrogenase MoFe protein from C. pasteurianum at 1.08 Å resolution and comparison to its distinct ortholog from A. vinelandii at atomic resolution reveals conserved structural arrangements that are significant to the function of nitrogenase. The X-ray crystal structure of the nitrogenase MoFe protein from Clostridium pasteurianum (Cp1) has been determined at 1.08 Å resolution by multiwavelength anomalous diffraction phasing. Cp1 and the ortholog from Azotobacter vinelandii (Av1) represent two distinct families of nitrogenases, differing primarily by a long insertion in the α-subunit and a deletion in the β-subunit of Cp1 relative to Av1. Comparison of these two MoFe protein structures at atomic resolution reveals conserved structural arrangements that are significant to the function of nitrogenase. The FeMo cofactors defining the active sites of the MoFe protein are essentially identical between the two proteins. The surrounding environment is also highly conserved, suggesting that this structural arrangement is crucial for nitrogen reduction. The P clusters are likewise similar, although the surrounding protein and solvent environment is less conserved relative to that of the FeMo cofactor. The P cluster and FeMo cofactor in Av1 and Cp1 are connected through a conserved water tunnel surrounded by similar secondary-structure elements. The long α-subunit insertion loop occludes the presumed Fe protein docking surface on Cp1 with few contacts to the remainder of the protein. This makes it plausible that this loop is repositioned to open up the Fe protein docking surface for complex formation.

  7. Abnormal macropore formation during double-sided gas tungsten arc welding of magnesium AZ91D alloy

    SciTech Connect (OSTI)

    Shen Jun You Guoqiang; Long Siyuan; Pan Fusheng

    2008-08-15

    One of the major concerns during gas tungsten arc (GTA) welding of cast magnesium alloys is the presence of large macroporosity in weldments, normally thought to occur from the presence of gas in the castings. In this study, a double-sided GTA welding process was adopted to join wrought magnesium AZ91D alloy plates. Micropores were formed in the weld zone of the first side that was welded, due to precipitation of H{sub 2} as the mushy zone freezes. When the reverse side was welded, the heat generated caused the mushy zone in the initial weld to reform. The micropores in the initial weld then coalesced and expanded to form macropores by means of gas expansion through small holes that are present at the grain boundaries in the partially melted zone. Macropores in the partially melted zone increase with increased heat input, so that when a filler metal is used the macropores are smaller in number and in size.

  8. Surface Structures of Cubo-octahedral Pt-Mo Catalyst Nanoparticles from Monte Carlo Simulations

    SciTech Connect (OSTI)

    Wang, Guofeng; Van Hove, M.A.; Ross, P.N.; Baskes, M.I.

    2005-03-31

    The surface structures of cubo-octahedral Pt-Mo nanoparticles have been investigated using the Monte Carlo method and modified embedded atom method potentials that we developed for Pt-Mo alloys. The cubo-octahedral Pt-Mo nanoparticles are constructed with disordered fcc configurations, with sizes from 2.5 to 5.0 nm, and with Pt concentrations from 60 to 90 at. percent. The equilibrium Pt-Mo nanoparticle configurations were generated through Monte Carlo simulations allowing both atomic displacements and element exchanges at 600 K. We predict that the Pt atoms weakly segregate to the surfaces of such nanoparticles. The Pt concentrations in the surface are calculated to be 5 to 14 at. percent higher than the Pt concentrations of the nanoparticles. Moreover, the Pt atoms preferentially segregate to the facet sites of the surface, while the Pt and Mo atoms tend to alternate along the edges and vertices of these nanoparticles. We found that decreasing the size or increasing the Pt concentration leads to higher Pt concentrations but fewer Pt-Mo pairs in the Pt-Mo nanoparticle surfaces.

  9. Surface composition, microstructure and corrosion resistance of AZ31 magnesium alloy irradiated by high-intensity pulsed ion beam

    SciTech Connect (OSTI)

    Li, P., E-mail: pli@sqnc.edu.cn [Department of Physics and Information Engineering, Shangqiu Normal University, Shangqiu 476000 (China); Surface Engineering Laboratory, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Lei, M.K., E-mail: surfeng@dlut.edu.cn [Surface Engineering Laboratory, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Zhu, X.P. [Surface Engineering Laboratory, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)

    2011-06-15

    High-intensity pulsed ion beam (HIPIB) irradiation of AZ31 magnesium alloy is performed and electrochemical corrosion experiment of irradiated samples is carried out by using potentiodynamic polarization technology in order to explore the effect of HIPIB irradiation on corrosion resistance of magnesium alloy. The surface composition, cross-sectional morphology and microstructure are characterized by using electron probe microanalyzer, optical microscope and transmission electron microscope, respectively. The results indicated that HIPIB irradiation leads to a significant improvement in corrosion resistance of magnesium alloy, in terms of the considerable increase in both corrosion potential and pitting breakdown potential. The microstructural refinement and surface purification induced by HIPIB irradiation are responsible for the improved corrosion resistance. - Research Highlights: {yields} A modified layer about 30 {mu}m thick is obtained by HIPIB irradiation. {yields} Selective ablation of element/impurity phase having lower melting point is observed. {yields} More importantly, microstructural refinement occurred on the irradiated surface. {yields} The modified layer exhibited a significantly improved corrosion resistance. {yields} Improved corrosion resistance is ascribed to the combined effect induced by HIPIB.

  10. Energy and Technolgy Assessment of Zinc and Magnesium Casting Plants, Technical Report Close-out, August 25,2006

    SciTech Connect (OSTI)

    Twin City Die Castings Company; Tom Heider; North American Die Castings Association

    2006-08-25

    Twin City Die Castings Company of Minneapolis, Minnesota, Twin City Die Castings Company was awarded project No. DE-FG36-05GO15097 to perform plant wide assessments of ten (10) die casting facilities that produce zinc and magnesium alloy castings in order to determine improvements and potential cost savings in energy use. Mr. Heider filled the role of team leader for the project and utilized the North American Die Casting Association (NADCA) to conduct audits at team participant plants so as to hold findings specific to each plant proprietary. The intended benefits of the project were to improve energy use through higher operational and process efficiency for the plants assessed. An improvement in energy efficiency of 5 15% was targeted. The primary objectives of the project was to: 1) Expand an energy and technology tool developed by the NADCA under a previous DOE project titled, Energy and Technology Assessment for Die Casting Plants for assessing aluminum die casting plants to be more specifically applicable to zinc and magnesium die casting facilities. 2) Conduct ten (10) assessments of zinc and magnesium die casting plants, within eight (8) companies, utilizing the assessment tool to identify, evaluate and recommend opportunities to enhance energy efficiency, minimize waste, and improve productivity. 3) Transfer the assessment tool to the die casting industry at large.

  11. Spectroscopic signatures of AA' and AB stacking of chemical vapor deposited bilayer MoS2

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

    Xia, Ming; Li, Bo; Yin, Kuibo; Capellini, Giovanni; Niu, Gang; Gong, Yongji; Zhou, Wu; Ajayan, Pulickel M.; Xie, Ya -Hong

    2015-11-04

    We discuss prominent resonance Raman and photoluminescence spectroscopic differences between AA'and AB stacked bilayer molybdenum disulfide (MoS2) grown by chemical vapor deposition are reported. Bilayer MoS2 islands consisting of the two stacking orders were obtained under identical growth conditions. Also, resonance Raman and photoluminescence spectra of AA' and AB stacked bilayer MoS2 were obtained on Au nanopyramid surfaces under strong plasmon resonance. Both resonance Raman and photoluminescence spectra show distinct features indicating clear differences in interlayer interaction between these two phases. The implication of these findings on device applications based on spin and valley degrees of freedom.

  12. Distributed Production of Radionuclide Mo-99 Charles A. Gentile, Adam B.

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

    Cohen and George Ascione | Princeton Plasma Physics Lab Distributed Production of Radionuclide Mo-99 Charles A. Gentile, Adam B. Cohen and George Ascione This invention is for the production of Technetium-99m (Tc-99m), a widely used medical isotope in a distributed and in-situ fashion. Tc-99m results when Molybdenum 99 (Mo-99) decays. Mo-99 is typically produced in a nuclear reactor, but it can be produced from naturally occurring Molybdenum 100 or from Molybdenum 98 using either neutrons or

  13. Understanding Low-cycle Fatigue Life Improvement Mechanisms in a Pre-twinned Magnesium Alloy

    SciTech Connect (OSTI)

    Wu, Wei; An, Ke

    2015-10-03

    The mechanisms of fatigue life improvement by pre-twinning process in a commercial rolled magnesium (Mg) alloy have been investigated using real-time in situ neutron diffraction under a continuous-loading condition. It is found that by introducing the excess twinned grains through pre-compression along the rolling direction the fatigue life was enhanced approximately 50%, mainly resulting from the prolonged detwinning process and inhibited dislocation slip during reverse tension. Moreover, after pre-twinning process, the removal of the rapid strain hardening during reverse tension leads to a compressive mean stress value and more symmetric shape of stress-strain hysteresis loop. The pre-twinning has significant impacts on the twinning-detwinning characteristics and deformation modes during cyclic loading and greatly facilitates the twinning-detwinning activities in plastic deformation. The cyclic straining leads to the increase of contribution of tensile twinning deformation in overall plastic deformation in both the as-received and pre-deformed sample. The mechanisms of load partitioning in different groups of grains are closely related to the deformation modes in each deformation stage, while the fatigue cycling has little influence on the load sharing. The pre-twinning process provides an easy and cost-effective route to improve the low-cycle fatigue life through manufacturing and processing, which would advance the wide application of light-weight wrought Mg alloys as structural materials.

  14. Effects of Pore Distributions on Ductility of Thin-Walled High Pressure Die-Cast Magnesium

    SciTech Connect (OSTI)

    Choi, Kyoo Sil; Li, Dongsheng; Sun, Xin; Li, Mei; Allison, John

    2013-06-01

    In this paper, a microstructure-based three-dimensional (3D) finite element modeling method is adopted to investigate the effects of porosity in thin-walled high pressure die-cast (HPDC) Magnesium alloys on their ductility. For this purpose, the cross-sections of AM60 casting samples are first examined using optical microscope and X-ray tomography to obtain the general information on the pore distribution features. The experimentally observed pore distribution features are then used to generate a series of synthetic microstructure-based 3D finite element models with different pore volume fractions and pore distribution features. Shear and ductile damage models are adopted in the finite element analyses to induce the fracture by element removal, leading to the prediction of ductility. The results in this study show that the ductility monotonically decreases as the pore volume fraction increases and that the effect of skin region on the ductility is noticeable under the condition of same local pore volume fraction in the center region of the sample and its existence can be beneficial for the improvement of ductility. The further synthetic microstructure-based 3D finite element analyses are planned to investigate the effects of pore size and pore size distribution.

  15. A Rac1--GDP trimer complex binds zinc with tetrahedral and octahedral coordination, displacing magnesium

    SciTech Connect (OSTI)

    Prehna, G.; Stebbins, C

    2007-01-01

    The Rho family of small GTPases represent well characterized signaling molecules that regulate many cellular functions such as actin cytoskeletal arrangement and the cell cycle by acting as molecular switches. A Rac1-GDP-Zn complex has been crystallized in space group P3221 and its crystal structure has been solved at 1.9 {angstrom} resolution. These trigonal crystals reveal the unexpected ability of Rac1 to coordinate Zn atoms in a tetrahedral fashion by use of its biologically relevant switch I and switch II regions. Upon coordination of zinc, the switch I region is stabilized in the GDP-bound conformation and contributes to a Rac1 trimer in the asymmetric unit. Zinc coordination causes switch II to adopt a novel conformation with a symmetry-related molecule. Additionally, zinc was found to displace magnesium from its octahedral coordination at switch I, although GDP binding remained stable. This structure represents the first reported Rac1-GDP-Zn complex, which further underscores the conformational flexibility and versatility of the small GTPase switch regions.

  16. A Rac1-GDP Trimer Complex Binds Zinc with Tetrahedral and Octahedral Coordination, Displacing Magnesium

    SciTech Connect (OSTI)

    Prehna,G.; Stebbins, E.

    2007-01-01

    The Rho family of small GTPases represent well characterized signaling molecules that regulate many cellular functions such as actin cytoskeletal arrangement and the cell cycle by acting as molecular switches. A Rac1-GDP-Zn complex has been crystallized in space group P3{sub 2}21 and its crystal structure has been solved at 1.9 {angstrom} resolution. These trigonal crystals reveal the unexpected ability of Rac1 to coordinate Zn atoms in a tetrahedral fashion by use of its biologically relevant switch I and switch II regions. Upon coordination of zinc, the switch I region is stabilized in the GDP-bound conformation and contributes to a Rac1 trimer in the asymmetric unit. Zinc coordination causes switch II to adopt a novel conformation with a symmetry-related molecule. Additionally, zinc was found to displace magnesium from its octahedral coordination at switch I, although GDP binding remained stable. This structure represents the first reported Rac1-GDP-Zn complex, which further underscores the conformational flexibility and versatility of the small GTPase switch regions.

  17. Tension-compression-tension tertiary twins in coarse-grained polycrystalline pure magnesium at room temperature

    SciTech Connect (OSTI)

    Yu, Qin; Jiang, Yanyao; Wang, Jian

    2015-04-07

    Using electron backscatter diffraction, the microstructural features of tension–compression–tension (T–C–T) tertiary twins are studied in coarse-grained pure polycrystalline magnesium subjected to monotonic compression along the extrusion direction in ambient air. T–C–T tertiary twins are developed due to the formation of a compression–tension double twin inside a primary tension twin. All the observed T–C–T twin variants are of TiCjTj type. TiCi+1Ti+1 (or TiCi–1Ti–1) variants are observed more frequently than TiCi+2Ti+2 (or TiCi–2Ti–2) variants. Moreover, the number of tertiary twin lamellae increases with the applied compressive strain.

  18. CHARACTERIZATION AND FORMABILITY OF CONTINUOUS-CAST AZ31B MAGNESIUM ALLOY SHEETS

    SciTech Connect (OSTI)

    Rohatgi, Aashish; Herling, Darrell R.; Nyberg, Eric A.

    2009-09-24

    The goal of this work is to understand the inter-relationship between the initial properties of continuous-cast magnesium alloy (AZ31B) sheets and their subsequent formability and post-formed mechanical performance for use in cost-effective, lightweight, automotive body panels. As-received sheets, provided by the Automotive Metals Division (AMD-602) team, were characterized by surface roughness measurements using mechanical profilometry. The arithmetic mean deviation of profile (Ra) and the maximum two-point height of profile (Ry) of the as-received sheets ranged from ~0.2-2 ?m and ~2-15 ?m, respectively. Several commercial lubricants were evaluated by thermal analysis and the liquid phase of the lubricants was found to evaporate/decompose upon heating leaving behind a solid residue upon heating to temperatures exceeding ~125-150C. Elevated temperature bending-under-tension (BUT) friction tests were conducted at 350C and the coefficient-of-friction values ranged from a minimum of ~0.1 (for tungsten disulfide lubricant) to ~0.7 when no lubricant was used. These results, in conjunction with those from the forming trials conducted by the AMD-602 team, will be eventually used to determine the role of sheet-die friction in determining the formability of AZ31B sheets.

  19. Characterisation of magnesium potassium phosphate cements blended with fly ash and ground granulated blast furnace slag

    SciTech Connect (OSTI)

    Gardner, Laura J.; Bernal, Susan A.; Walling, Samuel A.; Corkhill, Claire L.; Provis, John L.; Hyatt, Neil C.

    2015-08-15

    Magnesium potassium phosphate cements (MKPCs), blended with 50 wt.% fly ash (FA) or ground granulated blast furnace slag (GBFS) to reduce heat evolution, water demand and cost, were assessed using compressive strength, X-ray diffraction (XRD), scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR) spectroscopy on {sup 25}Mg, {sup 27}Al, {sup 29}Si, {sup 31}P and {sup 39}K nuclei. We present the first definitive evidence that dissolution of the glassy aluminosilicate phases of both FA and GBFS occurred under the pH conditions of MKPC. In addition to the main binder phase, struvite-K, an amorphous orthophosphate phase was detected in FA/MKPC and GBFS/MKPC systems. It was postulated that an aluminium phosphate phase was formed, however, no significant Al–O–P interactions were identified. High-field NMR analysis of the GBFS/MKPC system indicated the potential formation of a potassium-aluminosilicate phase. This study demonstrates the need for further research on these binders, as both FA and GBFS are generally regarded as inert fillers within MKPC.

  20. Passivation dynamics in the anisotropic deposition and stripping of bulk magnesium electrodes during electrochemical cycling

    SciTech Connect (OSTI)

    Wetzel, David J.; Malone, Marvin A.; Haasch, Richard T.; Meng, Yifei; Vieker, Henning; Hahn, Nathan; Golzhauser, Armin; Zuo, Jian-Min; Zavadil, Kevin R.; Gewirth, Andrew A.; Nuzzo, Ralph G.

    2015-08-10

    Rechargeable magnesium (Mg) batteries show promise for use as a next generation technology for high-density energy storage, though little is known about the Mg anode solid electrolyte interphase and its implications for the performance and durability of a Mg-based battery. We explore in this report passivation effects engendered during the electrochemical cycling of a bulk Mg anode, characterizing their influences during metal deposition and dissolution in a simple, nonaqueous, Grignard electrolyte solution (ethylmagnesium bromide, EtMgBr, in tetrahydrofuran). Scanning electron microscopy images of Mg foil working electrodes after electrochemical polarization to dissolution potentials show the formation of corrosion pits. The pit densities so evidenced are markedly potential-dependent. When the Mg working electrode is cycled both potentiostatically and galvanostatically in EtMgBr these pits, formed due to passive layer breakdown, act as the foci for subsequent electrochemical activity. Detailed microscopy, diffraction, and spectroscopic data show that further passivation and corrosion results in the anisotropic stripping of the Mg {0001} plane, leaving thin oxide-comprising passivated side wall structures that demark the {0001} fiber texture of the etched Mg grains. Upon long-term cycling, oxide side walls formed due to the pronounced crystallographic anisotropy of the anodic stripping processes, leading to complex overlay anisotropic, columnar structures, exceeding 50 μm in height. Finally, the passive responses mediating the growth of these structures appear to be an intrinsic feature of the electrochemical growth and dissolution of Mg using this electrolyte.

  1. Understanding Low-cycle Fatigue Life Improvement Mechanisms in a Pre-twinned Magnesium Alloy

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

    Wu, Wei; An, Ke

    2015-10-03

    The mechanisms of fatigue life improvement by pre-twinning process in a commercial rolled magnesium (Mg) alloy have been investigated using real-time in situ neutron diffraction under a continuous-loading condition. It is found that by introducing the excess twinned grains through pre-compression along the rolling direction the fatigue life was enhanced approximately 50%, mainly resulting from the prolonged detwinning process and inhibited dislocation slip during reverse tension. Moreover, after pre-twinning process, the removal of the rapid strain hardening during reverse tension leads to a compressive mean stress value and more symmetric shape of stress-strain hysteresis loop. The pre-twinning has significant impactsmore » on the twinning-detwinning characteristics and deformation modes during cyclic loading and greatly facilitates the twinning-detwinning activities in plastic deformation. The cyclic straining leads to the increase of contribution of tensile twinning deformation in overall plastic deformation in both the as-received and pre-deformed sample. The mechanisms of load partitioning in different groups of grains are closely related to the deformation modes in each deformation stage, while the fatigue cycling has little influence on the load sharing. The pre-twinning process provides an easy and cost-effective route to improve the low-cycle fatigue life through manufacturing and processing, which would advance the wide application of light-weight wrought Mg alloys as structural materials.« less

  2. Magnesium and Manganese Silicides For Efficient And Low Cost Thermo-Electric Power Generation

    SciTech Connect (OSTI)

    Trivedi, Sudhir B.; Kutcher, Susan W.; Rosemeier, Cory A.; Mayers, David; Singh, Jogender

    2013-12-02

    Thermoelectric Power Generation (TEPG) is the most efficient and commercially deployable power generation technology for harvesting wasted heat from such things as automobile exhausts, industrial furnaces, and incinerators, and converting it into usable electrical power. We investigated the materials magnesium silicide (Mg2Si) and manganese silicide (MnSi) for TEG. MgSi2 and MnSi are environmentally friendly, have constituent elements that are abundant in the earth's crust, non-toxic, lighter and cheaper. In Phase I, we successfully produced Mg2Si and MnSi material with good TE properties. We developed a novel technique to synthesize Mg2Si with good crystalline quality, which is normally very difficult due to high Mg vapor pressure and its corrosive nature. We produced n-type Mg2Si and p-type MnSi nanocomposite pellets using FAST. Measurements of resistivity and voltage under a temperature gradient indicated a Seebeck coefficient of roughly 120 V/K on average per leg, which is quite respectable. Results indicated however, that issues related to bonding resulted in high resistivity contacts. Determining a bonding process and bonding material that can provide ohmic contact from room temperature to the operating temperature is an essential part of successful device fabrication. Work continues in the development of a process for reproducibly obtaining low resistance electrical contacts.

  3. Passivation dynamics in the anisotropic deposition and stripping of bulk magnesium electrodes during electrochemical cycling

    SciTech Connect (OSTI)

    Wetzel, David J.; Malone, Marvin A.; Haasch, Richard T.; Meng, Yifei; Vieker, Henning; Hahn, Nathan; Golzhauser, Armin; Zuo, Jian-Min; Zavadil, Kevin R.; Gewirth, Andrew A.; Nuzzo, Ralph G.

    2015-08-10

    Rechargeable magnesium (Mg) batteries show promise for use as a next generation technology for high-density energy storage, though little is known about the Mg anode solid electrolyte interphase and its implications for the performance and durability of a Mg-based battery. We explore in this report passivation effects engendered during the electrochemical cycling of a bulk Mg anode, characterizing their influences during metal deposition and dissolution in a simple, nonaqueous, Grignard electrolyte solution (ethylmagnesium bromide, EtMgBr, in tetrahydrofuran). Scanning electron microscopy images of Mg foil working electrodes after electrochemical polarization to dissolution potentials show the formation of corrosion pits. The pit densities so evidenced are markedly potential-dependent. When the Mg working electrode is cycled both potentiostatically and galvanostatically in EtMgBr these pits, formed due to passive layer breakdown, act as the foci for subsequent electrochemical activity. Detailed microscopy, diffraction, and spectroscopic data show that further passivation and corrosion results in the anisotropic stripping of the Mg {0001} plane, leaving thin oxide-comprising passivated side wall structures that demark the {0001} fiber texture of the etched Mg grains. Upon long-term cycling, oxide side walls formed due to the pronounced crystallographic anisotropy of the anodic stripping processes, leading to complex overlay anisotropic, columnar structures, exceeding 50 ?m in height. Finally, the passive responses mediating the growth of these structures appear to be an intrinsic feature of the electrochemical growth and dissolution of Mg using this electrolyte.

  4. Chemical and mechanical consequences of environmental barrier coating exposure to calcium-magnesium-aluminosilicate.

    SciTech Connect (OSTI)

    Harder, B.; Ramirez-Rico, J.; Almer, J. D.; Kang, L.; Faber, K.

    2011-06-01

    The success of Si-based ceramics as high-temperature structural materials for gas turbine applications relies on the use of environmental barrier coatings (EBCs) with low silica activity, such as Ba{sub 1-x}Sr{sub x}Al{sub 2}Si{sub 2}O{sub 8} (BSAS), which protect the underlying components from oxidation and corrosion in combustion environments containing water vapor. One of the current challenges concerning EBC lifetime is the effect of sandy deposits of calcium-magnesium-aluminosilicate (CMAS) glass that melt during engine operation and react with the EBC, changing both its composition and stress state. In this work, we study the effect of CMAS exposure at 1300 C on the residual stress state and composition in BSAS-mullite-Si-SiC multilayers. Residual stresses were measured in BSAS multilayers exposed to CMAS for different times using high-energy X-ray diffraction. Their microstructure was studied using a combination of scanning electron microscopy and transmission electron microscopy techniques. Our results show that CMAS dissolves the BSAS topcoat preferentially through the grain boundaries, dislodging the grains and changing the residual stress state in the topcoat to a nonuniform and increasingly compressive stress state with increasing exposure time. The presence of CMAS accelerates the hexacelsian-to-celsian phase transformation kinetics in BSAS, which reacts with the glass by a solution-reprecipitation mechanism. Precipitates have crystallographic structures consistent with Ca-doped celsian and Ba-doped anorthite.

  5. Assessment of Computer Simulation Software and Process Data for High Pressure Die Casting of Magnesium

    SciTech Connect (OSTI)

    Sabau, Adrian S; Hatfield, Edward C; Dinwiddie, Ralph Barton; Kuwana, Kazunori; Viti, Valerio; Hassan, Mohamed I; Saito, Kozo

    2007-09-01

    Computer software for the numerical simulation of solidification and mold filling is an effective design tool for cast structural automotive magnesium components. A review of commercial software capabilities and their validation procedures was conducted. Aside form the software assessment, the program addressed five main areas: lubricant degradation, lubricant application, gate atomization, and heat transfer at metal mold interfaces. A test stand for lubricant application was designed. A sensor was used for the direct measurement of heat fluxes during lubricant application and casting solidification in graphite molds. Spray experiments were conducted using pure deionized water and commercial die lubricants. The results show that the sensor can be used with confidence for measuring heat fluxes under conditions specific to the die lube application. The data on heat flux was presented in forms suitable for use in HPDC simulation software. Severe jet breakup and atomization phenomena are likely to occur due to high gate velocities in HPDC. As a result of gate atomization, droplet flow affects the mold filling pattern, air entrapment, skin formation, and ensuing defects. Warm water analogue dies were designed for obtaining experimental data on mold filling phenomena. Data on break-up jet length, break-up pattern, velocities, and droplet size distribution were obtained experimentally and was used to develop correlations for jet break-up phenomena specific to die casting gate configurations.

  6. Elevated temperature stability of a 6% Mo superaustenitic stainless alloy

    SciTech Connect (OSTI)

    Grubb, J.F.

    1996-11-01

    A 6% Mo superaustenitic stainless alloy (UNS N08367) was exposed at temperatures in the 1,000 to 1,900 F (538 to 1,038 C) range for times up to 10,000 hours. The effect of these exposures on mechanical properties and corrosion resistance has been examined. Exposure of N08367 alloy at 1,900 F (1,056 C) for 1 to 10 hours does not result in precipitation of intermetallic phases, does not embrittle it, and does not degrade its corrosion resistance. Exposure of N08367 alloy at 1,300 to 1,800 F (704 to 982 C) does precipitate intermetallic phases, does embrittle it, and does degrade its corrosion resistance. Short-term exposure of N08367 alloy at 1,000 or 1,100 F (538 to 593 C) does not cause precipitation of intermetallic phases, with consequent embrittlement and loss of corrosion resistance, but long-term exposures do. Extrapolation of the embrittlement time vs. temperature curves shows that the current 800 F (427 C) use temperature limit for N08367 alloy is safe.

  7. Electrochemical Testing of Ni-Cr-Mo-Gd Alloys

    SciTech Connect (OSTI)

    T. E. Lister; R. E. Mizia; H. Tian

    2005-10-01

    The waste package site recommendation design specified a boron-containing stainless steel, Neutronit 976/978, for fabrication of the internal baskets that will be used as a corrosion-resistant neutron-absorbing material. Recent corrosion test results gave higher-than-expected corrosion rates for this material. The material callout for these components has been changed to a Ni-Cr-Mo-Gd alloy (ASTM-B 932-04, UNS N06464) that is being developed at the Idaho National Laboratory. This report discusses the results of initial corrosion testing of this material in simulated in-package environments that could contact the fuel baskets after breach of the waste package outer barrier. The corrosion test matrix was executed using the potentiodynamic and potentiostatic electrochemical test techniques. The alloy performance shows low rates of general corrosion after initial removal of a gadolinium-rich second phase that intersects the surface. The high halide-containing test solutions exhibited greater tendencies toward initiation of crevice corrosion.

  8. Thermo-physical Properties of DU-10 wt.% Mo Alloys

    SciTech Connect (OSTI)

    Douglas E. Burkes; Cynthia A. Papesch; Andrew P. Maddison; Thomas Hartmann; Francine J. Rice

    2010-08-01

    Low-enriched uranium alloyed with 10 wt% molybdenum is under consideration by the Global Threat Reduction Initiative reactor convert program as a very high density fuel to enable the conversion of high-performance research reactors away from highly-enriched uranium fuels. As with any fuel development program, the thermophysical properties of the fuel as a function of temperature are extremely important and must be well characterized in order to effectively model and predict fuel behavior under normal and off-normal irradiation conditions. For the alloy system under investigation, there is a lack of thermophysical property data, and in most cases, the data is relatively inconsistent and lacks sufficient explanation. Available literature on this alloy system comes mainly from studies done during the 1960s and 1970s, and often does not include sufficient information on fabrication history or conditions to draw conclusions for the current application. The current paper has investigated specific heat capacity, coefficient of linear thermal expansion, density, and thermal diffusivity that were then used to calculate alloy thermal conductivity as a function of temperature. The data obtained from this investigation was compared to available literature on similar U-Mo alloys, and in most cases are in good agreement.

  9. File:USDA-CE-Production-GIFmaps-MO.pdf | Open Energy Information

    Open Energy Info (EERE)

    MO.pdf Jump to: navigation, search File File history File usage Missouri Ethanol Plant Locations Size of this preview: 776 600 pixels. Full resolution (1,650 1,275 pixels,...

  10. DE-EM-0001971 WIPP M&O J-8 PART III - LIST OF DOCUMENTS, EXHIBITS...

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

    AND MEASUREMENT PLAN (PEMP) DE-EM-0001971 WIPP M&O J-9 Draft PERFORMANCE EVALUATION AND MEASUREMENT PLAN (PEMP) OCTOBER 1 (2012) through SEPTEMBER 30, (2013) Contract No. ...

  11. Giant and tunable valley degeneracy splitting in MoTe 2 (Journal...

    Office of Scientific and Technical Information (OSTI)

    This content will become publicly available on September 7, 2016 Title: Giant and tunable valley degeneracy splitting in MoTe 2 Authors: Qi, Jingshan ; Li, Xiao ; Niu, Qian ; Feng, ...

  12. Microscopic origin of low frequency noise in MoS{sub 2} field-effect transistors

    SciTech Connect (OSTI)

    Ghatak, Subhamoy; Jain, Manish; Ghosh, Arindam; Mukherjee, Sumanta; Sarma, D. D.

    2014-09-01

    We report measurement of low frequency 1/f noise in molybdenum di-sulphide (MoS{sub 2}) field-effect transistors in multiple device configurations including MoS{sub 2} on silicon dioxide as well as MoS{sub 2}-hexagonal boron nitride (hBN) heterostructures. All as-fabricated devices show similar magnitude of noise with number fluctuation as the dominant mechanism at high temperatures and density, although the calculated density of traps is two orders of magnitude higher than that at the SiO{sub 2} interface. Measurements on the heterostructure devices with vacuum annealing and dual gated configuration reveals that along with the channel, metal-MoS{sub 2} contacts also play a significant role in determining noise magnitude in these devices.

  13. Surface confined quantum well state in MoS{sub 2}(0001) thin...

    Office of Scientific and Technical Information (OSTI)

    Our findings of scQWS in MoSsub 2 shed some light on understanding the electronic properties of 2D materials with implications in future 2D electronic devices. Authors: Sun, ...

  14. Substrate interactions with suspended and supported monolayer MoS2: Angle-resolved photoemission spectroscopy

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

    Jin, Wencan; Yeh, Po -Chun; Zaki, Nader; Zhang, Datong; Liou, Jonathan T.; Dadap, Jerry I.; Barinov, Alexey; Yablonskikh, Mikhail; Sadowski, Jerzy T.; Sutter, Peter; et al

    2015-03-17

    We report the directly measured electronic structure of exfoliated monolayer molybdenum disulfide (MoS₂) using micrometer-scale angle-resolved photoemission spectroscopy. Measurements of both suspended and supported monolayer MoS₂ elucidate the effects of interaction with a substrate. Thus, a suggested relaxation of the in-plane lattice constant is found for both suspended and supported monolayer MoS₂ crystals. For suspended MoS₂, a careful investigation of the measured uppermost valence band gives an effective mass at Γ¯ and Κ¯ of 2.00m₀ and 0.43m₀, respectively. We also measure an increase in the band linewidth from the midpoint of Γ¯Κ¯ to the vicinity of Κ¯ and briefly discussmore » its possible origin.« less

  15. Large theoretical thermoelectric power factor of suspended single-layer MoS{sub 2}

    SciTech Connect (OSTI)

    Babaei, Hasan E-mail: babaei@auburn.edu; Khodadadi, J. M.; Sinha, Sanjiv

    2014-11-10

    We have calculated the semi-classical thermoelectric power factor of suspended single-layer (SL)- MoS{sub 2} utilizing electron relaxation times derived from ab initio calculations. Measurements of the thermoelectric power factor of SL-MoS{sub 2} on substrates reveal poor power factors. In contrast, we find the thermoelectric power factor of suspended SL-MoS{sub 2} to peak at ∼2.8 × 10{sup 4} μW/m K{sup 2} at 300 K, at an electron concentration of 10{sup 12} cm{sup −2}. This figure is higher than that in bulk Bi{sub 2}Te{sub 3}, for example. Given its relatively high thermal conductivity, suspended SL-MoS{sub 2} may hold promise for in-plane thin-film Peltier coolers, provided reasonable mobilities can be realized.

  16. Nanoscale Phase Separation In Epitaxial Cr-Mo and Cr-V Alloy...

    Office of Scientific and Technical Information (OSTI)

    In Epitaxial Cr-Mo and Cr-V Alloy Thin Films Studied Using Atom Probe Tomography. ... Therefor laser assisted atom probe tomography (APT) was utilized to study the phase ...

  17. A pseudo binary y-Gd solidification diagram for Ni-Cr-Mo-Gd alloys...

    Office of Scientific and Technical Information (OSTI)

    Title: A pseudo binary y-Gd solidification diagram for Ni-Cr-Mo-Gd alloys. No abstract prepared. Authors: Dupont, John Neuman 1 ; Minicozzi, Michael J. 1 ; Robino, Charles ...

  18. Bonding between graphene and MoS{sub 2} monolayers without and...

    Office of Scientific and Technical Information (OSTI)

    layer and in-gap states with linear dispersion contributed mostly by the graphene layer. ... Moreover, we calculate the dielectric function of the Li intercalated grapheneMoSsub 2 ...

  19. AB INITIO Modeling of Thermomechanical Properties of Mo-Based Alloys for Fossil Energy Conversion

    SciTech Connect (OSTI)

    Ching, Wai-Yim

    2013-12-31

    In this final scientific/technical report covering the period of 3.5 years started on July 1, 2011, we report the accomplishments on the study of thermo-mechanical properties of Mo-based intermetallic compounds under NETL support. These include computational method development, physical properties investigation of Mo-based compounds and alloys. The main focus is on the mechanical and thermo mechanical properties at high temperature since these are the most crucial properties for their potential applications. In particular, recent development of applying ab initio molecular dynamic (AIMD) simulations to the T1 (Mo{sub 5}Si{sub 3}) and T2 (Mo{sub 5}SiB{sub 2}) phases are highlighted for alloy design in further improving their properties.

  20. Microsoft Word - chapter FeNiCrMo_ver4.doc

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

    The carbon and alloy steel categories selected for the Technical Reference for Hydrogen ... Since a full range of data is not available for each steel, data for all Ni-Cr-Mo steels ...

  1. Monolayers of MoS{sub 2} as an oxidation protective nanocoating material

    SciTech Connect (OSTI)

    Sen, H. Sener; Sahin, H.; Peeters, F. M.; Durgun, E.

    2014-08-28

    First-principle calculations are employed to investigate the interaction of oxygen with ideal and defective MoS{sub 2} monolayers. Our calculations show that while oxygen atoms are strongly bound on top of sulfur atoms, the oxygen molecule only weakly interacts with the surface. The penetration of oxygen atoms and molecules through a defect-free MoS{sub 2} monolayer is prevented by a very high diffusion barrier indicating that MoS{sub 2} can serve as a protective layer for oxidation. The analysis is extended to WS{sub 2} and similar coating characteristics are obtained. Our calculations indicate that ideal and continuous MoS{sub 2} and WS{sub 2} monolayers can improve the oxidation and corrosion-resistance of the covered surface and can be considered as an efficient nanocoating material.

  2. Exceptionally high glass-forming ability of an FeCoCrMoCBY alloy...

    Office of Scientific and Technical Information (OSTI)

    Citation Details In-Document Search Title: Exceptionally ... Here we report the exceptionally high GFA of an FeCoCrMoCBY ... OSTI Identifier: 20702296 Resource Type: Journal Article ...

  3. A WSe{sub 2}/MoSe{sub 2} heterostructure photovoltaic device

    SciTech Connect (OSTI)

    Flöry, Nikolaus; Jain, Achint; Bharadwaj, Palash; Parzefall, Markus; Novotny, Lukas; Taniguchi, Takashi; Watanabe, Kenji

    2015-09-21

    We report on the photovoltaic effect in a WSe{sub 2}/MoSe{sub 2} heterojunction, demonstrating gate tunable current rectification with on/off ratios of over 10{sup 4}. Spatially resolved photocurrent maps show the photovoltaic effect to originate from the entire overlap region. Compared to WSe{sub 2}/MoS{sub 2} heterostructures, our devices perform better at long wavelengths and yield higher quantum efficiencies, in agreement with Shockley-Queisser theory.

  4. Climate Action Champions: Mid-America Regional Council, KS and MO |

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

    Department of Energy Mid-America Regional Council, KS and MO Climate Action Champions: Mid-America Regional Council, KS and MO The Mid-America Regional Council (MARC) is a nonprofit association of city and county governments and the metropolitan planning organization for the bistate Kansas City region. They provide a forum for the region to work together to advance social, economic and environmental progress. MARC received the Climate Action Champion designation in consortium with the City

  5. Demonstration of LED Street Lighting in Kansas City, MO (Technical Report)

    Office of Scientific and Technical Information (OSTI)

    | SciTech Connect Demonstration of LED Street Lighting in Kansas City, MO Citation Details In-Document Search Title: Demonstration of LED Street Lighting in Kansas City, MO Nine different streetlighting products were installed on various streets in Kansas City, Missouri during February, 2011, to evaluate their performance relative to the incumbent high-pressure sodium (HPS) lighting. The applications investigated included 100 W, 150 W, 250 W, and 400 W HPS installations. Initial measurements

  6. DOE - Office of Legacy Management -- Weldon Spring Chemical Co - MO 03

    Office of Legacy Management (LM)

    Weldon Spring Chemical Co - MO 03 FUSRAP Considered Sites Site: Weldon Spring Chemical Co. (MO.03) Designated Name: Alternate Name: Location: Evaluation Year: Site Operations: Site Disposition: Radioactive Materials Handled: Primary Radioactive Materials Handled: Radiological Survey(s): Site Status: Also see Weldon Spring, Missouri, Site Documents Related to Weldon Spring Chemical Co. Summary of Work Session - Focus Area: Monitoring and Maintenance. Summary of Weldon Spring Long-Term Stewardship

  7. U-EXTRACTION--IMPROVEMENTS IN ELIMINATION OF Mo BY USE OF FERRIC ION

    DOE Patents [OSTI]

    Clark, H.M.; Duffey, D.

    1958-06-10

    An improved solvent extraction process is described whereby U may be extracted by a water immiscible organic solvent from an aqueous solution of uranyl nitrate. It has been found that Mo in the presence of phosphate ions appears to form a complex with the phosphate which extracts along with the U. This extraction of Mo may be suppressed by providing ferric ion in the solution prior to the extraction step. The ferric ion is preferably provided in the form of ferric nitrate.

  8. Thermal stability of intermetallic phases in Fe-rich Fe-Cr-Ni-Mo alloys

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

    Yang, Ying; Tan, Lizhen; Busby, Jeremy T.

    2015-06-12

    Understanding the stability of precipitate phases in the Fe-rich Fe-Cr-Ni-Mo alloys is critical to the alloy design and application of Mo-containing Austenitic steels. Coupled with thermodynamic modeling, stability of the chi and Laves phases in two Fe-Cr-Ni-Mo alloys were investigated at 1000, 850 and 700 °C for different annealing time. The morphologies, compositions and crystal structures of the matrix and precipitate phases were carefully examined by Scanning Electron Microscopy, Electron Probe Microanalysis, X-ray diffraction and Transmission Electron Microscopy. The two key findings resulted from this work. One is that the chi phase is stable at high temperature and transformed intomore » the Laves phase at low temperature. The other is that both the chi and Laves phases have large solubilites of Cr, Mo and Ni, among which the Mo solubility has a major role on the relative stability of the precipitate phases. The developed thermodynamic models were then applied to evaluating the Mo effect on the stability of precipitate phases in AISI 316 and NF709 alloys.« less

  9. Thermal stability of intermetallic phases in Fe-rich Fe-Cr-Ni-Mo alloys

    SciTech Connect (OSTI)

    Yang, Ying; Tan, Lizhen; Busby, Jeremy T.

    2015-06-12

    Understanding the stability of precipitate phases in the Fe-rich Fe-Cr-Ni-Mo alloys is critical to the alloy design and application of Mo-containing Austenitic steels. Coupled with thermodynamic modeling, stability of the chi and Laves phases in two Fe-Cr-Ni-Mo alloys were investigated at 1000, 850 and 700 °C for different annealing time. The morphologies, compositions and crystal structures of the matrix and precipitate phases were carefully examined by Scanning Electron Microscopy, Electron Probe Microanalysis, X-ray diffraction and Transmission Electron Microscopy. The two key findings resulted from this work. One is that the chi phase is stable at high temperature and transformed into the Laves phase at low temperature. The other is that both the chi and Laves phases have large solubilites of Cr, Mo and Ni, among which the Mo solubility has a major role on the relative stability of the precipitate phases. The developed thermodynamic models were then applied to evaluating the Mo effect on the stability of precipitate phases in AISI 316 and NF709 alloys.

  10. MoS{sub 2} nanotube exfoliation as new synthesis pathway to molybdenum blue

    SciTech Connect (OSTI)

    Visic, B.; Gunde, M. Klanjsek; Kovac, J.; Iskra, I.; Jelenc, J.; Remskar, M.; Centre of Excellence Namaste, Jamova cesta 39, SI-1000 Ljubljana

    2013-02-15

    Graphical abstract: . Display Omitted Highlights: ? New synthesis approach to obtaining molybdenum blue via exfoliated MoS{sub 2} nanotubes. ? Material is prone to self assembly and is stable in high vacuum. ? Molecules are as small as 2 nm and their clusters are up to tens of nanometers. ? Change in absorption and oxidation states from the precursor MoS{sub 2}. -- Abstract: Molybdenum blue-type materials are usually obtained by partially reducing Mo{sup VI+} in acidic solutions, while in the presented method it is formed in ethanol solution of exfoliated MoS{sub 2} nanotubes, where the MoS{sub 2} flakes are the preferential location for their growth. Material was investigated by means of scanning electron and atomic force microscopy, showing the structure and self assembly, while also confirming that it is stable in high vacuum with molecules as small as 1.6 nm and the agglomerates of few tens of nanometres. The ultravioletvisible and photoelectron spectrometry show the change in absorption properties and oxidation states from MoS{sub 2} structure to molybdenum blue, while the presence of sulphur suggests that this is a new type of molybdenum blue material.

  11. High reflectance and low stress Mo2C/Be multilayers

    DOE Patents [OSTI]

    Bajt, Sasa; Barbee, Jr., Troy W.

    2001-01-01

    A material for extreme ultraviolet (EUV) multilayers that will reflect at about 11.3 nm, have a high reflectance, low stress, and high thermal and radiation stability. The material consists of alternating layers of Mo.sub.2 C and Be deposited by DC magnetron sputtering on a substrate, such as silicon. In one example a Mo.sub.2 C/Be multilayer gave 65.2% reflectance at 11.25 nm measured at 5 degrees off normal incidence angle, and consisted of 70 bilayers with a deposition period of 5.78 nm, and was deposited at 0.83 mTorr argon (Ar) sputtering pressure, with the first and last layers being Be. The stress of the multilayer is tensile and only +88 MPa, compared to +330 MPa of a Mo/Be multilayers of the same thickness. The Mo.sub.2 C/Be multilayer was capped with carbon which produced an increase in reflectivity of about 7% over a similar multilayer with no carbon capping material, thus raising the reflectivity from 58.3% to over 65%. The multilayers were formed using either Mo.sub.2 C or Be as the first and last layers, and initial testing has shown the formation of beryllium carbide at the interfaces between the layers which both stabilizes and has a smoothing effect, and appear to be smoother than the interfaces in Mo/Be multilayers.

  12. Effects of thermal treatment on the co-rolled U-Mo fuel foils

    SciTech Connect (OSTI)

    Dennis D. Keiser, Jr.; Tammy L. Trowbridge; Cynthia R. Breckenridge; Brady L. Mackowiak; Glenn A. Moore; Barry H. Rabin; Mitchell K. Meyer

    2014-11-01

    A monolithic fuel type is being developed to convert US high performance research and test reactors such as Advanced Test Reactor (ATR) at Idaho National Laboratory from highly enriched uranium (HEU) to low-enriched uranium (LEU). The interaction between the cladding and the U-Mo fuel meat during fuel fabrication and irradiation is known to have negative impacts on fuel performance, such as mechanical integrity and dimensional stability. In order to eliminate/minimize the direct interaction between cladding and fuel meat, a thin zirconium diffusion barrier was introduced between the cladding and U-Mo fuel meat through a co-rolling process. A complex interface between the zirconium and U-Mo was developed during the co-rolling process. A predictable interface between zirconium and U-Mo is critical to achieve good fuel performance since the interfaces can be the weakest link in the monolithic fuel system. A post co-rolling annealing treatment is expected to create a well-controlled interface between zirconium and U-Mo. A systematic study utilizing post co-rolling annealing treatment has been carried out. Based on microscopy results, the impacts of the annealing treatment on the interface between zirconium and U-Mo will be presented and an optima annealing treatment schedule will be suggested. The effects of the annealing treatment on the fuel performance will also be discussed.

  13. Atomic oxygen interaction with nickel multilayer and antimony oxide doped MoS{sub 2} films

    SciTech Connect (OSTI)

    Dugger, M.T.

    1994-12-31

    Sputtered MoS{sub 2} is a solid lubricant capable of ultralow friction coefficients (below 0.05) load-bearing capacity. Since it exhibits low friction in vacuum, low outgassing rate, is non-migrating and lacks organic binders, this material is an attractive lubricant for space mechanisms. To exploit these new materials to their fullest potential, designers of space-based motion systems require data on the effects of atomic oxygen exposure on dense, sputtered MoS{sub 2}. This paper describes the effects of atomic oxygen in low earth orbit on the friction and surface composition of sputtered MoS{sub 2} films. Sputtered multilayer films of MoS{sub 2} with nickel (0.7 nm Ni per 10 nm MoS{sub 2}, for 1 {mu}m total film thickness), and MoS{sub 2} cosputtered with antimony oxide (nominally 2 {mu}m thick) were exposed to 2.2 to 2.5 x 10{sup 20} oxygen/cm{sup 2} over a period of 42.25 hours in earth orbit on the United States space shuttle. Identical specimens were kept as controls in desiccated storage for the duration of the mission, and another set was exposed to an equivalent fluence of atomic oxygen in the laboratory. The friction coefficient in air and vacuum, and the composition of worn surfaces, were determined prior to the shuttle flight and again after the shuttle flight. Results are described.

  14. Stability of precipitate phases in Fe-rich Fe-Cr-Ni-Mo alloys

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

    Yang, Ying; Tan, Lizhen; Busby, Jeremy T

    2015-01-01

    Understanding the stability of precipitate phases in the Fe-rich Fe-Cr-Ni-Mo alloys is critical to the alloy design and application of Mo-containing Austenitic steels. Coupled with thermodynamic modeling, stability of the and phases in two Fe-Cr-Ni-Mo alloys were investigated at 1000, 850 and 700 C for different annealing time. The morphologies, compositions and crystal structures of the matrix and precipitate phases were carefully examined by Scanning Electron Microscopy, Electron Probe Microanalysis, X-ray diffraction and Transmission Electron Microscopy. Two key findings resulted from this work. One is that the phase is stable at high temperature and transformed into the phase at lowmoretemperature. The other is that both the and phases have large solubilites of Cr, Mo and Ni, among which the Mo solubility has a major role on the relative stability of the precipitate phases. The developed thermodynamic models were then applied to evaluating the Mo effect on the stability of precipitate phases in AISI 316 and NF709 alloys.less

  15. Synthesis of MoO{sub 3} nanoparticles for azo dye degradation by catalytic ozonation

    SciTech Connect (OSTI)

    Manivel, Arumugam; Lee, Gang-Juan; Chen, Chin-Yi; Chen, Jing-Heng; Ma, Shih-Hsin; Horng, Tzzy-Leng; Wu, Jerry J.

    2015-02-15

    Highlights: • Synthesis of one-dimensional MoO{sub 3} nanostructures using hydrothermal, microwave, and sonochemical methods. • Sonochemical synthesized MoO{sub 3} presents the best efficiency for the dye removal by catalytic ozonation. • Efficient environmental remediation process. - Abstract: One-dimensional molybdenum trioxide nanostructures were prepared in three different approaches, including thermal, microwave, and sonochemical methods. The physicochemical properties of the obtained MoO{sub 3} nanoparticles were investigated by diffused reflectance spectroscopy, X-ray diffraction analysis, field emission scanning electron microscopy, high resolution transmission electron microscopy, and Brunauer–Emmett–Teller surface area analysis. Among the methods as investigated, sonochemical synthesis gave well-dispersed fine MoO{sub 3} nanoparticles compared with the other approaches. All the synthesized MoO{sub 3} nanostructures were examined for the catalytic ozonation to degrade azo dye in aqueous environment. Different performances were obtained for the catalyst prepared in different methods and the catalytic efficiencies were found to be the order of sonochemical, microwave, and then thermal methods. The sonochemical MoO{sub 3} catalyst allowed the total dye removal within 20 min and its good performance was justified according to their higher surface area with higher number of active sites that provide effective dye interaction for better degradation.

  16. Thermal stability of intermetallic phases in Fe-rich Fe-Cr-Ni-Mo alloys

    SciTech Connect (OSTI)

    Yang, Ying; Tan, Lizhen; Busby, Jeremy T.

    2015-06-12

    Understanding the stability of precipitate phases in the Fe-rich Fe-Cr-Ni-Mo alloys is critical to the alloy design and application of Mo-containing Austenitic steels. Coupled with thermodynamic modeling, stability of the chi and Laves phases in two Fe-Cr-Ni-Mo alloys were investigated at 1000, 850 and 700 C for different annealing time. The morphologies, compositions and crystal structures of the matrix and precipitate phases were carefully examined by Scanning Electron Microscopy, Electron Probe Microanalysis, X-ray diffraction and Transmission Electron Microscopy. The two key findings resulted from this work. One is that the chi phase is stable at high temperature and transformed into the Laves phase at low temperature. The other is that both the chi and Laves phases have large solubilites of Cr, Mo and Ni, among which the Mo solubility has a major role on the relative stability of the precipitate phases. The developed thermodynamic models were then applied to evaluating the Mo effect on the stability of precipitate phases in AISI 316 and NF709 alloys.

  17. Collective electronic behaviors of laterally heterostructured armchair MoS{sub 2}-NbS{sub 2} nanoribbons

    SciTech Connect (OSTI)

    Wu, Nannan; Zhou, Wenzhe; Zou, Hui; Chen, Yu; Yang, Zhixiong; Xiong, Xiang; Ouyang, Fangping

    2015-08-28

    Based on density functional theory, we have investigated the electronic properties of molybdenum disulfide-niobium disulfide hybrid nanoribbons (MoS{sub 2}-NbS{sub 2} NRs). It is found that the MoS{sub 2} edge, MoS{sub 2} center, NbS{sub 2} edge, and NbS{sub 2} center have distinct contributions to the collective electronic behaviors of MoS{sub 2}-NbS{sub 2} NRs. Its behavior, metallic or semiconductor, depends on whether the central area of NR contains NbS{sub 2} chain or not. This dependence has been also revealed in the electronic structures of NbS{sub 2}-MoS{sub 2}-NbS{sub 2} NR and MoS{sub 2}-NbS{sub 2}-MoS{sub 2} NR, of which the former is semiconductor and the latter is metal. In comparison with MoS{sub 2} NR of the same width, the hybrid has a different bandgap that was caused by the coupled effects between NbS{sub 2} edge and MoS{sub 2} edge. This fact makes MoS{sub 2}-NbS{sub 2} NRs a possible candidate for nanoelectronic devices based on heterostructured transition-metal dichalcogenide.

  18. Microstructure evolution of Li uptake/removal in MoO{sub 2}@C nanoparticles with high lithium storage performance

    SciTech Connect (OSTI)

    Liu, Yulong; Zhang, Hong; Ouyang, Pan; Chen, Wenhao [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Li, Zhicheng, E-mail: zhchli@mail.csu.edu.cn [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China)

    2014-02-01

    Highlights: The carbon-coated MoO{sub 2} (MoO{sub 2}@C) ultra fine nanoparticles are synthesized by one-pot hydrothermal method. MoO{sub 2}@C nanoparticles have high specific capacity, excellent cycling performance and rate performance. Phase transformations for lithium ion uptake/removal are examined carefully by TEM. Phase transformations are highly reversible during the redox process. - Abstract: A facile one pot strategy of a hydrothermal methodology was applied to synthesize the carbon coated MoO{sub 2} (MoO{sub 2}@C) nanostructured particles, which are composed of ultra fine nanoparticles with homogeneous carbon coating about several nanometers. As an electrode in lithium ion batteries, the MoO{sub 2}@C shows a high specific capacity and reversible capacity (730 mA h g{sup ?1} after 60 cycles). Microstructure investigations, by using a high resolution transmission electron microscopy, of the MoO{sub 2}@C based electrodes employed at various states during the first discharge/charge cycle were conducted to elucidate the lithium ion uptake/removal mechanism and cycling behavior. In the lithium uptake process, the original MoO{sub 2} phase transfers into Li{sub 0.98}MoO{sub 2} through an addition type reaction, and then nanosized metallic Mo emerges as a result of a conversion reaction. In turn, Mo could be oxidized to the intermediate Li{sub 0.98}MoO{sub 2} before converting to hyperfine MoO{sub 2} phase on upcoming lithium removal process.

  19. A Double-Blind Placebo-Controlled Randomized Clinical Trial With Magnesium Oxide to Reduce Intrafraction Prostate Motion for Prostate Cancer Radiotherapy

    SciTech Connect (OSTI)

    Lips, Irene M.; Gils, Carla H. van; Kotte, Alexis N.T.J.; Leerdam, Monique E. van; Franken, Stefan P.G.; Heide, Uulke A. van der; Vulpen, Marco van

    2012-06-01

    Purpose: To investigate whether magnesium oxide during external-beam radiotherapy for prostate cancer reduces intrafraction prostate motion in a double-blind, placebo-controlled randomized trial. Methods and Materials: At the Department of Radiotherapy, prostate cancer patients scheduled for intensity-modulated radiotherapy (77 Gy in 35 fractions) using fiducial marker-based position verification were randomly assigned to receive magnesium oxide (500 mg twice a day) or placebo during radiotherapy. The primary outcome was the proportion of patients with clinically relevant intrafraction prostate motion, defined as the proportion of patients who demonstrated in {>=}50% of the fractions an intrafraction motion outside a range of 2 mm. Secondary outcome measures included quality of life and acute toxicity. Results: In total, 46 patients per treatment arm were enrolled. The primary endpoint did not show a statistically significant difference between the treatment arms with a percentage of patients with clinically relevant intrafraction motion of 83% in the magnesium oxide arm as compared with 80% in the placebo arm (p = 1.00). Concerning the secondary endpoints, exploratory analyses demonstrated a trend towards worsened quality of life and slightly more toxicity in the magnesium oxide arm than in the placebo arm; however, these differences were not statistically significant. Conclusions: Magnesium oxide is not effective in reducing the intrafraction prostate motion during external-beam radiotherapy, and therefore there is no indication to use it in clinical practice for this purpose.

  20. A magnesium-carboxylate framework showing luminescent sensing for CS{sub 2} and nitroaromatic compounds

    SciTech Connect (OSTI)

    Wu, Zhao-Feng; Tan, Bin; Feng, Mei-Ling; Du, Cheng-Feng; Huang, Xiao-Ying

    2015-03-15

    A magnesium metal-organic framework compound, namely [NH{sub 2}(CH{sub 3}){sub 2}][Mg{sub 3}(NDC){sub 2.5}(HCO{sub 2}){sub 2}(DMF){sub 0.75}(H{sub 2}O){sub 0.25}]·1.25DMF·0.75H{sub 2}O (1) (H{sub 2}NDC=1,4-naphthalene dicarboxylic acid, DMF=N,N′-dimethylformamide), has been synthesized in solvothermal conditions and structurally characterized. It features a three-dimensionally anionic framework with aligned channels parallel to the b-axis. Luminescent studies indicated that it showed significant luminescence quenching for carbon disulfide (CS{sub 2}) and nitrobenzene after being activated, at a content of only 3.0 and 0.1 vol% in DMF, respectively. In addition, the activated sample showed sensitive luminescence quenching for 1,3,5-trinitrophenol with a low concentration of 5×10{sup −5} mol/L. - Graphical abstract: Presented is a microporous 3D Mg-MOF, namely, [NH{sub 2}(CH{sub 3}){sub 2}][Mg{sub 3}(NDC){sub 2.5}(HCO{sub 2}){sub 2}(DMF){sub 0.75}(H{sub 2}O){sub 0.25}]·1.25DMF·0.75H{sub 2}O (1) (H{sub 2}NDC=1,4-naphthalene dicarboxylic acid) showing significant luminescence quenching for carbon disulfide and nitrobenzene. - Highlights: • A microporous 3D metal-organic framework based on Mg. • The compound shows significant luminescence quenching for CS{sub 2} and nitrobenzene after activated. • The compound shows sensitive luminescence quenching for 1,3,5-trinitrophenol with a low concentration of 5×10{sup −5} mol/L.

  1. Passivation dynamics in the anisotropic deposition and stripping of bulk magnesium electrodes during electrochemical cycling

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

    Wetzel, David J.; Malone, Marvin A.; Haasch, Richard T.; Meng, Yifei; Vieker, Henning; Hahn, Nathan; Golzhauser, Armin; Zuo, Jian-Min; Zavadil, Kevin R.; Gewirth, Andrew A.; et al

    2015-08-10

    Rechargeable magnesium (Mg) batteries show promise for use as a next generation technology for high-density energy storage, though little is known about the Mg anode solid electrolyte interphase and its implications for the performance and durability of a Mg-based battery. We explore in this report passivation effects engendered during the electrochemical cycling of a bulk Mg anode, characterizing their influences during metal deposition and dissolution in a simple, nonaqueous, Grignard electrolyte solution (ethylmagnesium bromide, EtMgBr, in tetrahydrofuran). Scanning electron microscopy images of Mg foil working electrodes after electrochemical polarization to dissolution potentials show the formation of corrosion pits. The pitmore » densities so evidenced are markedly potential-dependent. When the Mg working electrode is cycled both potentiostatically and galvanostatically in EtMgBr these pits, formed due to passive layer breakdown, act as the foci for subsequent electrochemical activity. Detailed microscopy, diffraction, and spectroscopic data show that further passivation and corrosion results in the anisotropic stripping of the Mg {0001} plane, leaving thin oxide-comprising passivated side wall structures that demark the {0001} fiber texture of the etched Mg grains. Upon long-term cycling, oxide side walls formed due to the pronounced crystallographic anisotropy of the anodic stripping processes, leading to complex overlay anisotropic, columnar structures, exceeding 50 μm in height. Finally, the passive responses mediating the growth of these structures appear to be an intrinsic feature of the electrochemical growth and dissolution of Mg using this electrolyte.« less

  2. Cyclopentadienyl-bis(oxazoline) magnesium and zirconium complexes in aminoalkene hydroaminations

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

    Eedugurala, Naresh; Hovey, Megan; Ho, Hung -An; Jana, Barun; Lampland, Nicole L.; Ellern, Arkady; Sadow, Aaron D.

    2015-11-25

    Here, a new class of cyclopentadiene-bis(oxazoline) compounds and their piano-stool-type organometallic complexes have been prepared as catalysts for hydroamination of aminoalkenes. The two compounds MeC(OxMe2)2C5H5 (BoMCpH; OxMe2 = 4,4-dimethyl-2-oxazoline) and MeC(OxMe2)2C5Me4H (BoMCptetH) are synthesized from C5R4HI (R = H, Me) and MeC(OxMe2)2Li. These cyclopentadiene-bis(oxazolines) are converted into ligands that support a variety of metal centers in piano-stool-type geometries, and here we report the preparation of Mg, Tl, Ti, and Zr compounds. BoMCpH and BoMCptetH react with MgMe2(O2C4H8)2 to give the magnesium methyl complexes {BoMCp}MgMe and {BoMCptet}MgMe. BoMCpH and BoMCptetH are converted to BoMCpTl and BoMCptetTl by reaction with TlOEt. Themore » thallium derivatives react with TiCl3(THF)3 to provide [{BoMCp}TiCl(μ-Cl)]2 and [{BoMCptet}TiCl(μ-Cl)]2, the former of which is crystallographically characterized as a dimeric species. BoMCpH and Zr(NMe2)4 react to eliminate dimethylamine and afford {BoMCp}Zr(NMe2)3, which is crystallographically characterized as a monomeric four-legged piano-stool compound. {BoMCp}Zr(NMe2)3, {BoMCp}MgMe, and {BoMCptet}MgMe are efficient catalysts for the hydroamination/cyclization of aminoalkenes under mild conditions.« less

  3. Color-Center Production and Formation in Electron-Irradiated Magnesium Aluminate Spinel and Ceria

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

    Costantini, Jean-Marc; Lelong, Gerald; Guillaumet, Maxime; Weber, William J.; Takaki, Seiya; Yasuda, Kazuhiro

    2016-06-20

    Single crystals of magnesium aluminate spinel (MgAl2O4) with (100) or (110) orientations and cerium dioxide or ceria (CeO2) were irradiated by 1.0-MeV and 2.5-MeV electrons in a high fluence range. Point-defect production was studied by off-line UV-visible optical spectroscopy after irradiation. For spinel, regardless of both crystal orientation and electron energy, two characteristic broad bands centered at photon energies of 5.4 eV and 4.9 eV were assigned to F and F+ centers (neutral and singly-ionized oxygen vacancies), respectively, on the basis of available literature data. No clear differences in colour-centre formation were observed for the two crystal orientations. Using calculationsmore » of displacement cross sections by elastic collisions, these results are consistent with a very large threshold displacement energy (200 eV) for oxygen atoms at RT. A third very broad band centered at 3.7 eV might be attributed either to an oxygen hole center (V-type center) or an F2 dimer center (oxygen di-vacancy). The onset of recovery of these color centers took place at 200°C with almost full bleaching at 600°C. Activation energies (~0.3-0.4 eV) for defect recovery were deduced from the isochronal annealing data by using a first-order kinetics analysis. For ceria, a sub band-gap absorption feature peaked at ~3.1 eV was recorded for 2.5-MeV electron irradiation only. Assuming a ballistic process, we suggest that the latter defect might result from cerium atom displacement on the basis of computed cross sections.« less

  4. MCNPX-CINDER'90 Simulation of Photonuclear Mo-99 Production Experiments

    SciTech Connect (OSTI)

    Kelsey, Charles T. IV [Los Alamos National Laboratory; Chemerizov, Sergey D. [Argonne National Laboratory; Dale, Gregory E. [Los Alamos National Laboratory; Harvey, James T. [NorthStar Medical Radioisotopes; Tkac, Peter [Argonne National Laboratory; Vandegrift, George R III [Argonne National Laboratory

    2011-01-01

    The MCNPX and CINDER'90 codes were used to support design of experiments investigating Mo-99 production with a 20-MeV electron beam. Bremsstrahlung photons produced by the electron beam interacting with the target drive the desired Mo-100({gamma},n)Mo-99 reaction, as well as many undesired reactions important to accurate prediction of radiation hazards. MCNPX is a radiation transport code and CINDER'90 is a transmutation code. They are routinely used together for accelerator activation calculations. Low energy neutron fluxes and production rates for nonneutron and high energy neutron induced reactions computed using MCNPX are inputs to CINDER'90. CINDER'90 presently has only a neutron reaction cross section library up to 25 MeV and normally the other reaction rates come from MCNPX physics models. For this work MCNPX photon flux tallies modified by energy response functions prepared from evaluated photonuclear cross section data were used to tally the reaction rates for CINDER'90 input. The cross section evaluations do not provide isomer to ground state yield ratios so a spin based approximation was used. Post irradiation dose rates were calculated using MCNPX with CINDER'90 produced decay photon spectra. The sensitivity of radionuclide activities and dose rates to beam parameters including energy, position, and profile, as well as underlying isomer assumptions, was investigated. Three experimental production targets were irradiated, two natural Mo and one Mo-100 enriched. Natural Mo foils upstream of the targets were used to analyze beam position and profile by exposing Gafchromic film to the foils after each irradiation. Activation and dose rate calculations were rerun after the experiments using measured beam parameters for comparison with measured Mo-99 activities and dose rates.

  5. Doping against the native propensity of MoS₂: Degenerate hole doping by cation substitution

    SciTech Connect (OSTI)

    Suh, Joonki; Park, Tae-Eon; Lin, Der-Yuh; Fu, Deyi; Park, Joonsuk; Jung, Hee Joon; Chen, Yabin; Ko, Changhyun; Jang, Chaun; Sun, Yinghui; Sinclair, Robert; Chang, Joonyeon; Tongay, Sefaattin; Wu, Junqiao

    2014-12-10

    Layered transition metal dichalcogenides (TMDs) draw much attention as the key semiconducting material for two-dimensional electrical, optoelectronic, and spintronic devices. For most of these applications, both n- and p-type materials are needed to form junctions and support bipolar carrier conduction. However, typically only one type of doping is stable for a particular TMD. For example, molybdenum disulfide (MoS₂) is natively an n-type presumably due to omnipresent electron-donating sulfur vacancies, and stable/controllable p-type doping has not been achieved. The lack of p-type doping hampers the development of charge-splitting p–n junctions of MoS₂, as well as limits carrier conduction to spin-degenerate conduction bands instead of the more interesting, spin-polarized valence bands. Traditionally, extrinsic p-type doping in TMDs has been approached with surface adsorption or intercalation of electron-accepting molecules. However, practically stable doping requires substitution of host atoms with dopants where the doping is secured by covalent bonding. In this work, we demonstrate stable p-type conduction in MoS₂ by substitutional niobium (Nb) doping, leading to a degenerate hole density of ~3 × 10¹⁹ cm⁻³. Structural and X-ray techniques reveal that the Nb atoms are indeed substitutionally incorporated into MoS₂ by replacing the Mo cations in the host lattice. van der Waals p–n homojunctions based on vertically stacked MoS₂ layers are fabricated, which enable gate-tunable current rectification. A wide range of microelectronic, optoelectronic, and spintronic devices can be envisioned from the demonstrated substitutional bipolar doping of MoS₂. From the miscibility of dopants with the host, it is also expected that the synthesis technique demonstrated here can be generally extended to other TMDs for doping against their native unipolar propensity.

  6. Gas sensing properties of magnesium doped SnO{sub 2} thin films in relation to AC conduction

    SciTech Connect (OSTI)

    Deepa, S.; Skariah, Benoy Thomas, Boben; Joseph, Anisha

    2014-01-28

    Conducting magnesium doped (0 to 1.5 wt %) tin oxide thin films prepared by Spray Pyrolysis technique achieved detection of 1000 ppm of LPG. The films deposited at 304 C exhibit an enhanced response at an operating temperature of 350 C. The microstructural properties are studied by means of X-ray diffraction. AC conductivity measurements are carried out using precision LCR meter to analyze the parameters that affect the variation in sensing. The results are correlated with compositional parameters and the subsequent modification in the charge transport mechanism facilitating an enhanced LPG sensing action.

  7. Zinc, iron, manganese, and magnesium accumulation in crayfish populations near copper-nickel smelters at Sudbury, Ontario, Canada

    SciTech Connect (OSTI)

    Bagatto, G.; Alikhan, M.A.

    1987-06-01

    The Sudbury basin has been subjected to extreme ecological disturbances from logging, mining and smelting activities. Elevated concentrations of copper, cadmium, and nickel have been reported in crayfish populations close to the Sudbury smelting works. The present study compares concentrations of zinc (Zn), iron (Fe), manganese (Mn) and magnesium (Mg) in freshwater crayfish at selected distances of the habitat from the emission source. These metals were selected since they are known to be emitted in moderately high quantities into the Sudbury environment as byproduct of the smelting process. Various tissue concentrations in crayfish were also examined to determined specific tissue sites for these accumulations.

  8. In Situ Time-Resolved Characterization of Ni-MoO2 Catalysts for the Water-Gas Shift Reaction

    SciTech Connect (OSTI)

    Wen,W.; Calderon, J.; Brito, J.; Marinkovic, N.; Hanson, J.; Rodriquez, J.

    2008-01-01

    Active catalysts for the water-gas shift (WGS, CO + H2O ? H2 + CO2) reaction were synthesized from nickel molybdates ({beta}-NiMoO4 and nH2O{center_dot}NiMoO4) as precursors, and their structural transformations were monitored using in situ time-resolved X-ray diffraction and X-ray absorption near-edge spectroscopy. In general, the nickel molybdates were not stable and underwent partial reduction in the presence of CO or CO/H2O mixtures at high temperatures. The interaction of {beta}-NiMoO4 with the WGS reactants at 500 C led to the formation of a mixture of Ni (24 nm particle size) and MoO2 (10 nm particle size). These Ni-MoO2 systems displayed good catalytic activity at 350, 400, and 500 C. At 350 and 400 C, catalytic tests revealed that the Ni-MoO2 system was much more active than isolated Ni (some activity) or isolated MoO2 (negligible activity). Thus, cooperative interactions between the admetal and oxide support were probably responsible for the high WGS activity of Ni-MoO2. In a second synthetic approach, the NiMoO4 hydrate was reduced to a mixture of metallic Ni, NiO, and amorphous molybdenum oxide by direct reaction with H2 gas at 350 C. In the first pass of the water-gas shift reaction, MoO2 appeared gradually at 500 C with a concurrent increase of the catalytic activity. For these catalysts, the particle size of Ni (4 nm) was much smaller than that of the MoO2 (13 nm). These systems were found to be much more active WGS catalysts than Cu-MoO2, which in turn is superior to commercial low-temperature Cu-ZnO catalysts.

  9. Method for the production of .sup.99m Tc compositions from .sup.99 Mo-containing materials

    DOE Patents [OSTI]

    Bennett, Ralph G.; Christian, Jerry D.; Grover, S. Blaine; Petti, David A.; Terry, William K.; Yoon, Woo Y.

    1998-01-01

    An improved method for producing .sup.99m Tc compositions from .sup.99 Mo compounds. .sup.100 Mo metal or .sup.100 MoO.sub.3 is irradiated with photons in a particle (electron) accelerator to ultimately produce .sup.99 MoO.sub.3. This composition is then heated in a reaction chamber to form a pool of molten .sup.99 MoO.sub.3 with an optimum depth of 0.5-5 mm. A gaseous mixture thereafter evolves from the molten .sup.99 MoO.sub.3 which contains vaporized .sup.99 MoO.sub.3, vaporized .sup.99m TcO.sub.3, and vaporized .sup.99m TcO.sub.2. This mixture is then combined with an oxidizing gas (O.sub.2(g)) to generate a gaseous stream containing vaporized .sup.99m Tc.sub.2 O.sub.7 and vaporized .sup.99 MoO.sub.3. Next, the gaseous stream is cooled in a primary condensation stage in the reaction chamber to remove vaporized .sup.99 MoO.sub.3. Cooling is undertaken at a specially-controlled rate to achieve maximum separation efficiency. The gaseous stream is then cooled in a sequential secondary condensation stage to convert vaporized .sup.99m Tc.sub.2 O.sub.7 into a condensed .sup.99m Tc-containing reaction product which is collected.

  10. Method for the production of {sup 99m}Tc compositions from {sup 99}Mo-containing materials

    DOE Patents [OSTI]

    Bennett, R.G.; Christian, J.D.; Grover, S.B.; Petti, D.A.; Terry, W.K.; Yoon, W.Y.

    1998-09-01

    An improved method is described for producing {sup 99m}Tc compositions from {sup 99}Mo compounds. {sup 100}Mo metal or {sup 100}MoO{sub 3} is irradiated with photons in a particle (electron) accelerator to ultimately produce {sup 99}MoO{sub 3}. This composition is then heated in a reaction chamber to form a pool of molten {sup 99}MoO{sub 3} with an optimum depth of 0.5--5 mm. A gaseous mixture thereafter evolves from the molten {sup 99}MoO{sub 3} which contains vaporized {sup 99}MoO{sub 3}, vaporized {sup 99m}TcO{sub 3}, and vaporized {sup 99m}TcO{sub 2}. This mixture is then combined with an oxidizing gas (O{sub 2(g)}) to generate a gaseous stream containing vaporized {sup 99m}Tc{sub 2}O{sub 7} and vaporized {sup 99}MoO{sub 3}. Next, the gaseous stream is cooled in a primary condensation stage in the reaction chamber to remove vaporized {sup 99}MoO{sub 3}. Cooling is undertaken at a specially-controlled rate to achieve maximum separation efficiency. The gaseous stream is then cooled in a sequential secondary condensation stage to convert vaporized {sup 99m}Tc{sub 2}O{sub 7} into a condensed {sup 99m}Tc-containing reaction product which is collected. 1 fig.

  11. Elementary Steps of Syngas Reactions on Mo2C(001): Adsorption Thermochemistry and Bond Dissociation

    SciTech Connect (OSTI)

    Medford, Andrew

    2012-02-16

    Density functional theory (DFT) and ab initio thermodynamics are applied in order to investigate the most stable surface and subsurface terminations of Mo{sub 2}C(001) as a function of chemical potential and in the presence of syngas. The Mo-terminated (001) surface is then used as a model surface to evaluate the thermochemistry and energetic barriers for key elementary steps in syngas reactions. Adsorption energy scaling relations and Broensted-Evans-Polanyi relationships are established and used to place Mo{sub 2}C into the context of transition metal surfaces. The results indicate that the surface termination is a complex function of reaction conditions and kinetics. It is predicted that the surface will be covered by either C{sub 2}H{sub 2} or O depending on conditions. Comparisons to transition metals indicate that the Mo-terminated Mo{sub 2}C(001) surface exhibits carbon reactivity similar to transition metals such as Ru and Ir, but is significantly more reactive towards oxygen.

  12. FeAl and Mo-Si-B Intermetallic Coatings Prepared by Thermal Spraying

    SciTech Connect (OSTI)

    Totemeier, T.C.; Wright, R.N.; Swank, W.D.

    2003-04-22

    FeAl and Mo-Si-B intermetallic coatings for elevated temperature environmental resistance were prepared using high-velocity oxy-fuel (HVOF) and air plasma spray (APS) techniques. For both coating types, the effect of coating parameters (spray particle velocity and temperature) on the microstructure and physical properties of the coatings was assessed. Fe-24Al (wt.%) coatings were prepared using HVOF thermal spraying at spray particle velocities varying from 540 m/s to 700 m/s. Mo-13.4Si-2.6B coatings were prepared using APS at particle velocities of 180 and 350 m/s. Residual stresses in the HVOF FeAl coatings were compressive, while stresses in the APS Mo-Si-B coatings were tensile. In both cases, residual stresses became more compressive with increasing spray particle velocity due to increased peening imparted by the spray particles. The hardness and elastic moduli of FeAl coatings also increased with increasing particle velocity, again due to an increased peening effect. For Mo-Si-B coatings, plasma spraying at 180 m/s resulted in significant oxidation of the spray particles and conversion of the T1 phase into amorphous silica and {alpha}-Mo. The T1 phase was retained after spraying at 350 m/s.

  13. Fragile structural transition in Mo3Sb7

    SciTech Connect (OSTI)

    Yan, Jiaqiang -Q.; McGuire, Michael A; May, Andrew F; Parker, David S.; Mandrus, D. G.; Sales, Brian C.

    2015-08-10

    Mo3Sb7 single crystals lightly doped with Cr, Ru, or Te are studied in order to explore the interplay between superconductivity, magnetism, and the cubic-tetragonal structural transition. The structural transition at 53 K is extremely sensitive to Ru or Te substitution which introduces additional electrons, but robust against Cr substitution. We observed no sign of a structural transition in superconducting Mo2.91Ru0.09Sb7 and Mo3Sb6.975Te0.025. In contrast, 3 at.% Cr doping only slightly suppresses the structural transition to 48 K while leaving no trace of superconductivity above 1.8 K. Analysis of magnetic properties suggests that the interdimer interaction in Mo3Sb7 is near a critical value and essential for the structural transition. Futhermore, all dopants suppress the superconductivity of Mo3Sb7. The tetragonal structure is not necessary for superconductivity.

  14. TEM Characterization of High Burn-up Microstructure of U-7Mo Alloy

    SciTech Connect (OSTI)

    Jian Gan; Brandon Miller; Dennis Keiser; Adam Robinson; James Madden; Pavel Medvedev; Daniel Wachs

    2014-04-01

    As an essential part of global nuclear non-proliferation effort, the RERTR program is developing low enriched U-Mo fuels (< 20% U-235) for use in research and test reactors that currently employ highly enriched uranium fuels. One type of fuel being developed is a dispersion fuel plate comprised of U-7Mo particles dispersed in Al alloy matrix. Recent TEM characterizations of the ATR irradiated U-7Mo dispersion fuel plates include the samples with a local fission densities of 4.5, 5.2, 5.6 and 6.3 E+21 fissions/cm3 and irradiation temperatures of 101-136?C. The development of the irradiated microstructure of the U-7Mo fuel particles consists of fission gas bubble superlattice, large gas bubbles, solid fission product precipitates and their association to the large gas bubbles, grain subdivision to tens or hundreds of nanometer size, collapse of bubble superlattice, and amorphisation. This presentation will describe the observed microstructures specifically focusing on the U-7Mo fuel particles. The impact of the observed microstructure on the fuel performance and the comparison of the relevant features with that of the high burn-up UO2 fuels will be discussed.

  15. Surface oxidation energetics and kinetics on MoS{sub 2} monolayer

    SciTech Connect (OSTI)

    KC, Santosh; Longo, Roberto C.; Wallace, Robert M.; Cho, Kyeongjae

    2015-04-07

    In this work, surface oxidation of monolayer MoS{sub 2} (one of the representative semiconductors in transition-metal dichalcogenides) has been investigated using density functional theory method. Oxygen interaction with MoS{sub 2} shows that, thermodynamically, the surface tends to be oxidized. However, the dissociative absorption of molecular oxygen on the MoS{sub 2} surface is kinetically limited due to the large energy barrier at low temperature. This finding elucidates the air stability of MoS{sub 2} surface in the atmosphere. Furthermore, the presence of defects significantly alters the surface stability and adsorption mechanisms. The electronic properties of the oxidized surface have been examined as a function of oxygen adsorption and coverage as well as substitutional impurities. Our results on energetics and kinetics of oxygen interaction with the MoS{sub 2} monolayer are useful for the understanding of surface oxidation, air stability, and electronic properties of transition-metal dichalcogenides at the atomic scale.

  16. Atomistic modeling of nanowires, small-scale fatigue damage in cast magnesium, and materials for MEMS.

    SciTech Connect (OSTI)

    Dunn, Martin L.; Talmage, Mellisa J.; McDowell, David L., 1956- (,-Georgia Institute of Technology, Atlanta, GA); West, Neil (University of Colorado, Boulder, CO); Gullett, Philip Michael (Mississippi State University , MS); Miller, David C. (University of Colorado, Boulder, CO); Spark, Kevin (University of Colorado, Boulder, CO); Diao, Jiankuai (University of Colorado, Boulder, CO); Horstemeyer, Mark F. (Mississippi State University , MS); Zimmerman, Jonathan A.; Gall, K

    2006-10-01

    titled 'Atomistic Modeling of Nanowires, Small-scale Fatigue Damage in Cast Magnesium, and Materials for MEMS'. This project supported a strategic partnership between Sandia National Laboratories and the University of Colorado at Boulder by providing funding for the lead author, Ken Gall, and his students, while he was a member of the University of Colorado faculty.

  17. Cyclopentadienyl-bis(oxazoline) magnesium and zirconium complexes in aminoalkene hydroaminations

    SciTech Connect (OSTI)

    Eedugurala, Naresh; Hovey, Megan; Ho, Hung -An; Jana, Barun; Lampland, Nicole L.; Ellern, Arkady; Sadow, Aaron D.

    2015-11-25

    Here, a new class of cyclopentadiene-bis(oxazoline) compounds and their piano-stool-type organometallic complexes have been prepared as catalysts for hydroamination of aminoalkenes. The two compounds MeC(OxMe2)2C5H5 (BoMCpH; OxMe2 = 4,4-dimethyl-2-oxazoline) and MeC(OxMe2)2C5Me4H (BoMCptetH) are synthesized from C5R4HI (R = H, Me) and MeC(OxMe2)2Li. These cyclopentadiene-bis(oxazolines) are converted into ligands that support a variety of metal centers in piano-stool-type geometries, and here we report the preparation of Mg, Tl, Ti, and Zr compounds. BoMCpH and BoMCptetH react with MgMe2(O2C4H8)2 to give the magnesium methyl complexes {BoMCp}MgMe and {BoMCptet}MgMe. BoMCpH and BoMCptetH are converted to BoMCpTl and BoMCptetTl by reaction with TlOEt. The thallium derivatives react with TiCl3(THF)3 to provide [{BoMCp}TiCl(μ-Cl)]2 and [{BoMCptet}TiCl(μ-Cl)]2, the former of which is crystallographically characterized as a dimeric species. BoMCpH and Zr(NMe2)4 react to eliminate dimethylamine and afford {BoMCp}Zr(NMe2)3, which is crystallographically characterized as a monomeric four-legged piano-stool compound. {BoMCp}Zr(NMe2)3, {BoMCp}MgMe, and {BoMCptet}MgMe are efficient catalysts for the hydroamination/cyclization of aminoalkenes under mild conditions.

  18. The role of twinning deformation on the hardening response of polycrystalline magnesium from discrete dislocation dynamics simulations

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

    Fan, Haidong; Aubry, Sylvie; Arsenlis, Athanasios; El-Awady, Jaafar A.

    2015-04-13

    The mechanical response of micro-twinned polycrystalline magnesium was studied through three-dimensional discrete dislocation dynamics (DDD). A systematic interaction model between dislocations and (1012) tension twin boundaries (TBs) was proposed and introduced into the DDD framework. In addition, a nominal grain boundary (GB) model agreeing with experimental results was also introduced to mimic the GB’s barrier effect. The current simulation results show that TBs act as a strong obstacle to gliding dislocations, which contributes significantly to the hardening behavior of magnesium. On the other hand, the deformation accommodated by twinning plays a softening role. Therefore, the concave shape of the Mgmore » stress-strain curve results from the competition between dislocation-TB induced hardening and twinning deformation induced softening. At low strain levels, twinning deformation induced softening dominates and a decreasing hardening rate is observed in Stage-I. In Stage-II, both the hardening and softening effects decline, but twinning deformation induced softening declines faster, which leads to an increasing hardening rate.« less

  19. Controlling the metal to semiconductor transition of MoS2 and WS2 in solution

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

    Chou, Stanley Shihyao; Yi-Kai Huang; Kim, Jaemyung; Kaehr, Bryan James; Foley, Brian M.; Lu, Ping; Conner Dykstra; Hopkins, Patrick E.; Brinker, C. Jeffrey; Jiaxing Huang; et al

    2015-01-22

    Lithiation-exfoliation produces single to few-layered MoS2 and WS2 sheets dispersible in water. However, the process transforms them from the pristine semiconducting 2H phase to a distorted metallic phase. Recovery of the semiconducting properties typically involves heating of the chemically exfoliated sheets at elevated temperatures. Therefore, it has been largely limited to sheets deposited on solid substrates. We report the dispersion of chemically exfoliated MoS2 sheets in high boiling point organic solvents enabled by surface functionalization and the controllable recovery of their semiconducting properties directly in solution. Ultimately, this process connects the scalability of chemical exfoliation with the simplicity of solutionmore » processing, enabling a facile method for tuning the metal to semiconductor transitions of MoS2 and WS2 within a liquid medium.« less

  20. Observation of localized states in atomically thin MoS{sub 2} field effect transistor

    SciTech Connect (OSTI)

    Ghatak, Subhamoy; Pal, Atindra Nath; Ghosh, Arindam

    2013-12-04

    We present electrical transport and low frequency (1/f) noise measurements on mechanically exfoliated single, bi and trilayer MoS{sub 2}-based FET devices on Si/SiO{sub 2} substrate. We find that the electronic states in MoS{sub 2} are localized at low temperatures (T) and conduction happens through variable range hopping (VRH). A steep increase of 1/f noise with decreasing T, typical for localized regime was observed in all of our devices. From gate voltage dependence of noise, we find that the noise power is inversely proportional to square of the number density (? 1/n{sup 2}) for a wide range of T, indicating number density fluctuations to be the dominant source of 1/f noise in these MoS{sub 2} FETs.

  1. Exciton-dominant electroluminescence from a diode of monolayer MoS{sub 2}

    SciTech Connect (OSTI)

    Ye, Yu; Ye, Ziliang; Gharghi, Majid; Zhu, Hanyu; Wang, Yuan; Zhao, Mervin; Yin, Xiaobo; Zhang, Xiang

    2014-05-12

    In two-dimensional monolayer MoS{sub 2}, excitons dominate the absorption and emission properties. However, the low electroluminescent efficiency and signal-to-noise ratio limit our understanding of the excitonic behavior of electroluminescence. Here, we study the microscopic origin of the electroluminescence from a diode of monolayer MoS{sub 2} fabricated on a heavily p-type doped silicon substrate. Direct and bound-exciton related recombination processes are identified from the electroluminescence. At a high electron-hole pair injection rate, Auger recombination of the exciton-exciton annihilation of the bound exciton emission is observed at room temperature. Moreover, the efficient electrical injection demonstrated here allows for the observation of a higher energy exciton peak of 2.255?eV in the monolayer MoS{sub 2} diode, attributed to the excited exciton state of a direct-exciton transition.

  2. Electronic and magnetic properties of Mo doped graphene; full potential approach

    SciTech Connect (OSTI)

    Thakur, Jyoti Kashyap, Manish K.; Singh, Mukhtiyar; Saini, Hardev S.

    2015-05-15

    The electronic and magnetic properties of Pristine and Mo doped Graphene have been calculated using WIEN2k implementation of full potential linearized augmented plane wave (FPLAPW) method based on Density Functional Theory (DFT). The exchange and correlation (XC) effects were taken into account by generalized gradient approximation (GGA). The calculated results show that Mo doping creates magnetism in Graphene by shifting the energy levels at E{sub F} and opens up a channel for Graphene to be used in real nanoscale device applications. The unpaired d-electrons of Mo atom are responsible for induced magnetism in Graphene. Magnetic ordering created in Graphene in this way makes it suitable for recording media, magnetic sensors, magnetic inks and spintronic devices.

  3. Highly conducting SrMoO{sub 3} thin films for microwave applications

    SciTech Connect (OSTI)

    Radetinac, Aldin Mani, Arzhang; Ziegler, Jürgen; Alff, Lambert; Komissinskiy, Philipp; Melnyk, Sergiy; Nikfalazar, Mohammad; Zheng, Yuliang; Jakoby, Rolf

    2014-09-15

    We have measured the microwave resistance of highly conducting perovskite oxide SrMoO{sub 3} thin film coplanar waveguides. The epitaxial SrMoO{sub 3} thin films were grown by pulsed laser deposition and showed low mosaicity and smooth surfaces with a root mean square roughness below 0.3 nm. Layer-by-layer growth could be achieved for film thicknesses up to 400 nm as monitored by reflection high-energy electron diffraction and confirmed by X-ray diffraction. We obtained a constant microwave resistivity of 29 μΩ·cm between 0.1 and 20 GHz by refining the frequency dependence of the transmission coefficients. Our result shows that SrMoO{sub 3} is a viable candidate as a highly conducting electrode material for all-oxide microwave electronic devices.

  4. Thermal stability of fission gas bubble superlattice in irradiated U10Mo fuel

    SciTech Connect (OSTI)

    Gan, J.; Keiser, D. D.; Miller, B. D.; Robinson, A. B.; Wachs, D. M.; Meyer, M. K.

    2015-09-01

    To investigate the thermal stability of the fission gas bubble superlattice, a key microstructural feature in both irradiated U-7Mo dispersion and U-10Mo monolithic fuel plates, a FIB-TEM sample of the irradiated U-10Mo fuel with a local fission density of 3.51021 fissions/cm3 was used for an in-situ heating TEM experiment. The temperature of the heating holder was raised at a ramp rate of approximately 10 C/min up to ~700 C, kept at that temperature for about 34 min, continued to 850 C with a reduced rate of 5 C/min. The result shows a high thermal stability of the fission gas bubble superlattice. The implication of this observation on the fuel microstructural evolution and performance under irradiation is discussed.

  5. Research update: Spin transfer torques in permalloy on monolayer MoS2

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

    Zhang, Wei; Sklenar, Joseph; Hsu, Bo; Jiang, Wanjun; Jungfleisch, Matthias B.; Xiao, Jiao; Fradin, Frank Y.; Liu, Yaohua; Pearson, John E.; Ketterson, John B.; et al

    2016-03-03

    We observe current induced spin transfertorque resonance in permalloy (Py) grown on monolayer MoS2. By passing rf current through the Py/MoS2 bilayer, field-like and damping-like torques are induced which excite the ferromagnetic resonance of Py. The signals are detected via a homodyne voltage from anisotropic magnetoresistance of Py. In comparison to other bilayer systems with strong spin-orbit torques, the monolayer MoS2 cannot provide bulk spin Hall effects and thus indicates the purely interfacial nature of the spin transfer torques. Furthermore, our results indicate the potential of two-dimensional transition-metal dichalcogenide for the use of interfacial spin-orbitronics applications.

  6. Thermal aging modeling and validation on the Mo containing Fe-Cr-Ni alloys

    SciTech Connect (OSTI)

    Yang, Ying; Tan, Lizhen; Busby, Jeremy T.

    2015-04-01

    Thermodynamics of intermetallic phases in Fe-rich Fe-Cr-Ni-Mo alloys is critical knowledge to understand thermal aging effect on the phase stability of Mo-containing austenitic steels, which subsequently facilitates alloy design/improvement and degradation mitigation of these materials for reactor applications. Among the intermetallic phases, Chi (χ), Laves, and Sigma (σ) are often of concern because of their tendency to cause embrittlement of the materials. The focus of this study is thermal stability of the Chi and Laves phases as they were less studied compared to the Sigma phase. Coupled with thermodynamic modeling, thermal stability of intermetallic phases in Mo containing Fe-Cr-Ni alloys was investigated at 1000, 850 and 700 C for different annealing times. The morphologies, compositions and crystal structures of the precipitates of the intermetallic phases were carefully examined by scanning electron microscopy, electron probe microanalysis, X-ray diffraction, and transmission electron microscopy. Three key findings resulted from this study. First, the Chi phase is stable at high temperature, and with decreasing temperature it transforms into the Laves phase that is stable at low temperature. Secondly, Cr, Mo, Ni are soluble in both the Chi and Laves phases, with the solubility of Mo playing a major role in the relative stability of the intermetallic phases. Thirdly, in situ transformation from Chi phase to Laves phase was directly observed, which increased the local strain field, generated dislocations in the intermetallic phases, and altered the precipitate phase orientation relationship with the austenitic matrix. The thermodynamic models that were developed and validated were then applied to evaluating the effect of Mo on the thermal stability of intermetallic phases in type 316 and NF709 stainless steels.

  7. Electrical and photovoltaic characteristics of MoS{sub 2}/Si p-n junctions

    SciTech Connect (OSTI)

    Hao, Lanzhong Liu, Yunjie Gao, Wei; Han, Zhide; Xue, Qingzhong; Zeng, Huizhong; Wu, Zhipeng; Zhu, Jun; Zhang, Wanli

    2015-03-21

    Bulk-like molybdenum disulfide (MoS{sub 2}) thin films were deposited on the surface of p-type Si substrates using dc magnetron sputtering technique and MoS{sub 2}/Si p-n junctions were formed. The vibrating modes of E{sup 1}{sub 2g} and A{sub 1g} were observed from the Raman spectrum of the MoS{sub 2} films. The current density versus voltage (J-V) characteristics of the junction were investigated. A typical J-V rectifying effect with a turn-on voltage of 0.2 V was shown. In different voltage range, the electrical transporting of the junction was dominated by diffusion current and recombination current, respectively. Under the light illumination of 15 mW cm{sup −2}, the p-n junction exhibited obvious photovoltaic characteristics with a short-circuit current density of 3.2 mA cm{sup −2} and open-circuit voltage of 0.14 V. The fill factor and energy conversion efficiency were 42.4% and 1.3%, respectively. According to the determination of the Fermi-energy level (∼4.65 eV) and energy-band gap (∼1.45 eV) of the MoS{sub 2} films by capacitance-voltage curve and ultraviolet-visible transmission spectra, the mechanisms of the electrical and photovoltaic characteristics were discussed in terms of the energy-band structure of the MoS{sub 2}/Si p-n junctions. The results hold the promise for the integration of MoS{sub 2} thin films with commercially available Si-based electronics in high-efficient photovoltaic devices.

  8. Two-step growth of two-dimensional WSe2/MoSe2 heterostructures

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

    Gong, Yongji; Lei, Sidong; Lou, Jun; Liu, Zheng; Vajtai, Robert; Zhou, Wu; Ajayan, Pullikel M.; Ye, Gonglan; Li, Bo; He, Yongmin; et al

    2015-08-03

    Two dimensional (2D) materials have attracted great attention due to their unique properties and atomic thickness. Although various 2D materials have been successfully synthesized with different optical and electrical properties, a strategy for fabricating 2D heterostructures must be developed in order to construct more complicated devices for practical applications. Here we demonstrate for the first time a two-step chemical vapor deposition (CVD) method for growing transition-metal dichalcogenide (TMD) heterostructures, where MoSe2 was synthesized first and followed by an epitaxial growth of WSe2 on the edge and on the top surface of MoSe2. Compared to previously reported one-step growth methods, thismore » two-step growth has the capability of spatial and size control of each 2D component, leading to much larger (up to 169 μm) heterostructure size, and cross-contamination can be effectively minimized. Furthermore, this two-step growth produces well-defined 2H and 3R stacking in the WSe2/MoSe2 bilayer regions and much sharper in-plane interfaces than the previously reported MoSe2/WSe2 heterojunctions obtained from one-step growth methods. The resultant heterostructures with WSe2/MoSe2 bilayer and the exposed MoSe2 monolayer display rectification characteristics of a p-n junction, as revealed by optoelectronic tests, and an internal quantum efficiency of 91% when functioning as a photodetector. As a result, a photovoltaic effect without any external gates was observed, showing incident photon to converted electron (IPCE) efficiencies of approximately 0.12%, providing application potential in electronics and energy harvesting.« less

  9. SEM and TEM Characterization of As-Fabricated U-7Mo Disperson Fuel Plates

    SciTech Connect (OSTI)

    D. D. Keiser, Jr.; B. Yao; E. Perez; Y. H. Sohn

    2009-11-01

    The starting microstructure of a dispersion fuel plate can have a dramatic impact on the overall performance of the plate during irradiation. To improve the understanding of the as-fabricated microstructures of dispersion fuel plates, SEM and TEM analysis have been performed on RERTR-9A archive fuel plates, which went through an additional hot isostatic procsssing (HIP) step during fabrication. The fuel plates had depleted U-7Mo fuel particles dispersed in either Al-2Si or 4043 Al alloy matrix. For the characterized samples, it was observed that a large fraction of the ?-phase U-7Mo alloy particles had decomposed during fabrication, and in areas near the fuel/matrix interface where the transformation products were present significant fuel/matrix interaction had occurred. Relatively thin Si-rich interaction layers were also observed around the U-7Mo particles. In the thick interaction layers, (U)(Al,Si)3 and U6Mo4Al43 were identified, and in the thin interaction layers U(Al,Si)3, U3Si3Al2, U3Si5, and USi1.88-type phases were observed. The U3Si3Al2 phase contained some Mo. Based on the results of this work, exposure of dispersion fuel plates to relatively high temperatures during fabrication impacts the overall microstructure, particularly the nature of the interaction layers around the fuel particles. The time and temperature of fabrication should be carefully controlled in order to produce the most uniform Si-rich layers around the U-7Mo particles.

  10. Morgan Wascko Imperial College London M.O. Wascko FNAL User's Meeting

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

    from the BooNEs Morgan Wascko Imperial College London M.O. Wascko FNAL User's Meeting M. Sorel Goals of the BooNEs * MiniBooNE: Confirm or rule out LSND * SciBooNE: * Near detector measurements for MiniBooNE * Precise cross section measurements * Especially useful for T2K 2 M.O. Wascko FNAL User's Meeting Goals of the BooNEs * MiniBooNE: Confirm or rule out LSND * SciBooNE: * Near detector measurements for MiniBooNE * Precise cross section measurements * Especially useful for T2K 2 W + ν µ n p

  11. Neutrino-nucleus scattering of {sup 95,97}Mo and {sup 116}Cd

    SciTech Connect (OSTI)

    Ydrefors, E.; Almosly, W.; Suhonen, J.

    2013-12-30

    Accurate knowledge about the nuclear responses to supernova neutrinos for relevant nuclear targets is important both for neutrino detection and for astrophysical applications. In this paper we discuss the cross sections for the charged-current neutrino-nucleus scatterings off {sup 95,97}Mo and {sup 116}Cd. The microscopic quasiparticle-phonon model is adopted for the odd-even nuclei {sup 95,97}Mo. In the case of {sup 116}Cd we present cross sections both for the Bonn one-boson-exchange potential and self-consistent calculations based on modern Skyrme interactions.

  12. Primary arm spacing in chill block melt spun Ni-Mo alloys

    SciTech Connect (OSTI)

    Tewari, S.N.; Glasgow, T.K.

    1986-01-01

    Chill block melt spun ribbons of Ni-Mo binary alloys containing 8.0 to 41.8 wt % Mo have been prepared under carefully controlled processing conditions. The growth velocity has been determined as a function of distance from the quench surface from the observed ribbon thickness dependence on the melt puddle residence time. Primary arm spacings measured at the midribbon thickness locations show a dependence on growth velocity and alloy composition which is expected from dendritic growth models for binary alloys directionally solidified in a positive temperature gradient.

  13. Persistent photoconductivity in two-dimensional Mo1-xW xSe2–MoSe2 van der Waals heterojunctions

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

    Puretzky, Alexander A.; Basile, Leonardo; Idrobo, Juan Carlos; Rouleau, Christopher M.; Geohegan, David B.; Xiao, Kai; Li, Xufan; Lin, Ming -Wei; Wang, Kei

    2016-02-16

    Van der Waals (vdW) heterojunctions consisting of vertically-stacked individual or multiple layers of two-dimensional (2D) layered semiconductors, especially the transition metal dichalcogenides (TMDs), are fascinating new artificial solids just nanometers-thin that promise novel optoelectronic functionalities due to the sensitivity of their electronic and optical properties to strong quantum confinement and interfacial interactions. Here, monolayers of n-type MoSe2 and p-type Mo1-xW xSe2–MoSe2 are grown by vapor transport methods, then transferred and stamped to form artificial vdW heterostructures with different interlayer orientations. Atomic-resolution Z-contrast electron microscopy and electron diffraction are used to characterize both the individual monolayers and the atomic registry betweenmore » layers in the bilayer vdW heterostructures. These measurements are compared with photoluminescence and low-frequency Raman spectroscopy, which indicates strong interlayer coupling in heterostructures. Remarkably, the heterojunctions exhibit an unprecedented photoconductivity effect that persists at room temperature for several days. This persistent photoconductivity is shown to be tunable by applying a gate bias that equilibrates the charge distribution. Furthermore, these measurements indicate that such ultrathin vdW heterojunctions can function as rewritable optoelectronic switches or memory elements under time-dependent photo-illumination, an effect which appears promising for new monolayer TMDs-based optoelectronic devices applications.« less

  14. Catalytic activity in lithium-treated core–shell MoOx/MoS2 nanowires

    SciTech Connect (OSTI)

    Cummins, Dustin R.; Martinez, Ulises; Kappera, Rajesh; Voiry, Damien; Martinez-Garcia, Alejandro; Jasinski, Jacek; Kelly, Dan; Chhowalla, Manish; Mohite, Aditya D.; Sunkara, Mahendra K.; Gupta, Gautam

    2015-09-22

    Significant interest has grown in the development of earth-abundant and efficient catalytic materials for hydrogen generation. Layered transition metal dichalcogenides present opportunities for efficient electrocatalytic systems. Here, we report the modification of 1D MoOx/MoS2 core–shell nanostructures by lithium intercalation and the corresponding changes in morphology, structure, and mechanism of H2 evolution. The 1D nanowires exhibit significant improvement in H2 evolution properties after lithiation, reducing the hydrogen evolution reaction (HER) onset potential by ~50 mV and increasing the generated current density by ~600%. The high electrochemical activity in the nanowires results from disruption of MoS2 layers in the outer shell, leading to increased activity and concentration of defect sites. This is in contrast to the typical mechanism of improved catalysis following lithium exfoliation, i.e., crystal phase transformation. As a result, these structural changes are verified by a combination of Raman and X-ray photoelectron spectroscopy (XPS).

  15. Photoelectron imaging spectroscopy of MoC{sup −} and NbN{sup −} diatomic anions: A comparative study

    SciTech Connect (OSTI)

    Liu, Qing-Yu; Li, Zi-Yu; He, Sheng-Gui E-mail: chenh@iccas.ac.cn; Hu, Lianrui; Chen, Hui E-mail: chenh@iccas.ac.cn; Ning, Chuan-Gang; Ma, Jia-Bi

    2015-04-28

    The isoeletronic diatomic MoC{sup −} and NbN{sup −} anions have been prepared by laser ablation and studied by photoelectron imaging spectroscopy combined with quantum chemistry calculations. The photoelectron spectra of NbN{sup −} can be very well assigned on the basis of literature reported optical spectroscopy of NbN. In contrast, the photoelectron spectra of MoC{sup −} are rather complex and the assignments suffered from the presence of many electronically hot bands and limited information from the reported optical spectroscopy of MoC. The electron affinities of NbN and MoC have been determined to be 1.450 ± 0.003 eV and 1.360  ±  0.003 eV, respectively. The good resolution of the imaging spectroscopy provided a chance to resolve the Ω splittings of the X{sup 3}Σ{sup −} (Ω = 0 and 1) state of MoC and the X{sup 4}Σ{sup −} (Ω = 1/2 and 3/2) state of MoC{sup −} for the first time. The spin-orbit splittings of the X{sup 2}Δ state of NbN{sup −} and the a{sup 2}Δ state of MoC{sup −} were also determined. The similarities and differences between the electronic structures of the NbN and MoC systems were discussed.

  16. Single-layer MoS{sub 2} roughness and sliding friction quenching by interaction with atomically flat substrates

    SciTech Connect (OSTI)

    Quereda, J.; Castellanos-Gomez, A.; Agrat, N.; Rubio-Bollinger, G.

    2014-08-04

    We experimentally study the surface roughness and the lateral friction force in single-layer MoS{sub 2} crystals deposited on different substrates: SiO{sub 2}, mica, and hexagonal boron nitride (h-BN). Roughness and sliding friction measurements are performed by atomic force microscopy. We find a strong dependence of the MoS{sub 2} roughness on the underlying substrate material, being h-BN the substrate which better preserves the flatness of the MoS{sub 2} crystal. The lateral friction also lowers as the roughness decreases, and attains its lowest value for MoS{sub 2} flakes on h-BN substrates. However, it is still higher than for the surface of a bulk MoS{sub 2} crystal, which we attribute to the deformation of the flake due to competing tip-to-flake and flake-to-substrate interactions.

  17. High blue-near ultraviolet photodiode response of vertically stacked graphene-MoS{sub 2}-metal heterostructures

    SciTech Connect (OSTI)

    Wi, Sungjin; Chen, Mikai; Nam, Hongsuk; Liu, Amy C.; Meyhofer, Edgar; Liang, Xiaogan

    2014-06-09

    We present a study on the photodiode response of vertically stacked graphene/MoS{sub 2}/metal heterostructures in which MoS{sub 2} layers are doped with various plasma species. In comparison with undoped heterostructures, such doped ones exhibit significantly improved quantum efficiencies in both photovoltaic and photoconductive modes. This indicates that plasma-doping-induced built-in potentials play an important role in photocurrent generation. As compared to indium-tin-oxide/ MoS{sub 2}/metal structures, the presented graphene/MoS{sub 2}/metal heterostructures exhibit greatly enhanced quantum efficiencies in the blue-near ultraviolet region, which is attributed to the low density of recombination centers at graphene/MoS{sub 2} heterojunctions. This work advances the knowledge for making photo-response devices based on layered materials.

  18. Research and Education of CO{sub 2} Separation from Coal Combustion Flue Gases with Regenerable Magnesium Solutions

    SciTech Connect (OSTI)

    Lee, Joo-Youp

    2013-09-30

    A novel method using environment-friendly chemical magnesium hydroxide (Mg(OH){sub 2}) solution to capture carbon dioxide from coal-fired power plants flue gas has been studied under this project in the post-combustion control area. The project utilizes the chemistry underlying the CO{sub 2}-Mg(OH){sub 2} system and proven and well-studied mass transfer devices for high levels of CO{sub 2} removal. The major goals of this research were to select and design an appropriate absorber which can absorb greater than 90% CO{sub 2} gas with low energy costs, and to find and optimize the operating conditions for the regeneration step. During the project period, we studied the physical and chemical characteristics of the scrubbing agent, the reaction taking place in the system, development and evaluation of CO{sub 2} gas absorber, desorption mechanism, and operation and optimization of continuous operation. Both batch and continuous operations were performed to examine the effects of various parameters including liquid-to-gas ratio, residence time, lean solvent concentration, pressure drop, bed height, CO{sub 2} partial pressure, bubble size, pH, and temperature on the absorption. The dissolution of Mg(OH){sub 2} particles, formation of magnesium carbonate (MgCO{sub 3}), and vapor-liquid-solid equilibrium (VLSE) of the system were also studied. The dissolution of Mg(OH){sub 2} particles and the steady release of magnesium ions into the solution was a crucial step to maintain a level of alkalinity in the CO{sub 2} absorption process. The dissolution process was modeled using a shrinking core model, and the dissolution reaction between proton ions and Mg(OH){sub 2} particles was found to be a rate-controlling step. The intrinsic surface reaction kinetics was found to be a strong function of temperature, and its kinetic expression was obtained. The kinetics of MgCO{sub 3} formation was also studied in terms of different pH values and temperatures, and was enhanced under high p

  19. The Microstructure of Rolled Plates from Cast Billets of U-10Mo Alloys

    SciTech Connect (OSTI)

    Nyberg, Eric A.; Joshi, Vineet V.; Burkes, Douglas; Lavender, Curt A.

    2015-03-01

    This report covers the examination of 13 samples of rolled plates from three separate castings of uranium, alloyed with 10 wt% molybdenum (U-10Mo) which were sent from the Y-12 National Security Complex (Y12) to the Pacific Northwest National Laboratory (PNNL).

  20. A New Molybdenum Nitride Catalyst with Rhombohedral MoS2 Structure for Hydrogenation Applications

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

    Wang, Shanmin; Ge, Hui; Sun, Shouli; Zhang, Jianzhong; Liu, Fangming; Wen, Xiaodong; Yu, Xiaohui; Wang, Liping; Zhang, Yi; Xu, Hongwu; et al

    2015-03-23

    Nitrogen-rich transition-metal nitrides hold great promise to be the next-generation catalysts for clean and renewable energy applications. However, incorporation of nitrogen into the crystalline lattices of transition metals is thermodynamically unfavorable at atmospheric pressure; most of the known transition metal nitrides are nitrogen-deficient with molar ratios of N:metal less than a unity. In this work, we have formulated a high-pressure route for the synthesis of a nitrogen-rich molybdenum nitride through a solid-state ion-exchange reaction. The newly discovered nitride, 3R-MoN2, adopts a rhombohedral R3m structure, isotypic with MoS2. This new nitride exhibits catalytic activities that are three times more active thanmore » the traditional catalyst MoS2 for the hydrodesulfurization of dibenzothiophene and more than twice as high in the selectivity to hydrogenation. The nitride is also catalytically active in sour methanation of syngas with >80% CO and H2 conversion at 723 K. Lastly, our formulated route for the synthesis of 3R-MoN2 is at a moderate pressure of 3.5 GPa and, thus, is feasible for industrial-scale catalyst production.« less

  1. MoS{sub 2} functionalization for ultra-thin atomic layer deposited dielectrics

    SciTech Connect (OSTI)

    Azcatl, Angelica; McDonnell, Stephen; Santosh, K.C.; Peng, Xin; Dong, Hong; Qin, Xiaoye; Addou, Rafik; Lu, Ning; Kim, Moon J.; Cho, Kyeongjae; Wallace, Robert M.; Mordi, Greg I.; Kim, Jiyoung

    2014-03-17

    The effect of room temperature ultraviolet-ozone (UV-O{sub 3}) exposure of MoS{sub 2} on the uniformity of subsequent atomic layer deposition of Al{sub 2}O{sub 3} is investigated. It is found that a UV-O{sub 3} pre-treatment removes adsorbed carbon contamination from the MoS{sub 2} surface and also functionalizes the MoS{sub 2} surface through the formation of a weak sulfur-oxygen bond without any evidence of molybdenum-sulfur bond disruption. This is supported by first principles density functional theory calculations which show that oxygen bonded to a surface sulfur atom while the sulfur is simultaneously back-bonded to three molybdenum atoms is a thermodynamically favorable configuration. The adsorbed oxygen increases the reactivity of MoS{sub 2} surface and provides nucleation sites for atomic layer deposition of Al{sub 2}O{sub 3}. The enhanced nucleation is found to be dependent on the thin film deposition temperature.

  2. Ferromagnetic superexchange in insulating Cr2MoO6 by controlling orbital hybridization

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

    Zhu, M.; Do, D.; Dela Cruz, Clarina R.; Dun, Zhiling; Cheng, J. -G.; Goto, H.; Uwatoko, Yoshiya; Zou, T.; Zhou, Haidon D.; Mahanti, Subhendra D.; et al

    2015-09-11

    We report the magnetic and electronic structures of the newly synthesized inverse-trirutile compound Cr2MoO6. Despite the same crystal symmetry and similar bond-lengths and bond-angles to Cr2TeO6, Cr2MoO6 possesses a magnetic structure of the Cr2MoO6 type, different from that seen in Cr2TeO6. Ab-initio electronic structure calculations show that the sign and strength of the Cr-O-Cr exchange coupling is strongly influenced by the hybridization between Mo 4d and O 2p orbitals. This result further substantiates our recently proposed mechanism for tuning the exchange interaction between two magnetic atoms by modifying the electronic states of the non-magnetic atoms in the exchange path throughmore » orbital hybridization. This approach is fundamentally different from the conventional methods of controlling the exchange interaction by either carrier injection or through structural distortions.« less

  3. Equation of state of bcc-Mo by static volume compression to 410 GPa

    SciTech Connect (OSTI)

    Akahama, Yuichi; Hirao, Naohisa; Ohishi, Yasuo; Singh, Anil K.

    2014-12-14

    Unit cell volumes of Mo and Pt have been measured simultaneously to ≈400 GPa by x-ray powder diffraction using a diamond anvil cell and synchrotron radiation source. The body-centered cubic (bcc) phase of Mo was found to be stable up to 410 GPa. The equation of state (EOS) of bcc-Mo was determined on the basis of Pt pressure scale. A fit of Vinet EOS to the volume compression data gave K{sub 0} = 262.3(4.6) GPa, K{sub 0}′ = 4.55(16) with one atmosphere atomic volume V{sub 0} = 31.155(24) A{sup 3}. The EOS was in good agreement with the previous ultrasonic data within pressure difference of 2.5%–3.3% in the multimegabar range, though the EOS of Mo proposed from a shock compression experiment gave lower pressure by 7.2%–11.3% than the present EOS. The agreement would suggest that the Pt pressure scale provides an accurate pressure value in an ultra-high pressure range.

  4. EIS-0475: Disposition of the Bannister Federal Complex, Kansas City, MO

    Office of Energy Efficiency and Renewable Energy (EERE)

    NNSA/DOE announces its intent to prepare an EIS for the disposition of the Bannister Federal Complex, Kansas City, MO. NNSA previously decided in a separate NEPA review (EA-1592) to relocate its operations from the Bannister Federal Complex to a newly constructed industrial campus eight miles from the current location.

  5. MoSi 2 Oxidation in 670-1498 K Water Vapor

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

    Sooby Wood, Elizabeth; Parker, Stephen S.; Nelson, Andrew T.; Maloy, Stuart A.; Butt, D.

    2016-03-08

    Molybdenum disilicide (MoSi2) has well documented oxidation resistance at high temperature (T > 1273 K) in dry O2 containing atmospheres due to the formation of a passive SiO2 surface layer. But, its behavior under atmospheres where water vapor is the dominant species has received far less attention. Oxidation testing of MoSi2 was performed at temperatures ranging from 670–1498 K in both 75% water vapor and synthetic air (Ar-O2, 80%–20%) containing atmospheres. Here the thermogravimetric and microscopy data describing these phenomena are presented. Over the temperature range investigated, MoSi2 displays more mass gain in water vapor than in air. The oxidationmore » kinetics observed in water vapor differ from that of the air samples. Two volatile oxides, MoO2(OH)2 and Si(OH)4, are thought to be the species responsible for the varied kinetics, at 670–877 K and at 1498 K, respectively. Finally, we observed an increase in oxidation (140–300 mg/cm2) from 980–1084 K in water vapor, where passivation is observed in air.« less

  6. A novel Mo-W interlayer approach for CVD diamond deposition on steel

    SciTech Connect (OSTI)

    Kundrát, Vojtěch; Sullivan, John; Ye, Haitao; Zhang, Xiaoling; Cooke, Kevin; Sun, Hailin

    2015-04-15

    Steel is the most widely used material in engineering for its cost/performance ratio and coatings are routinely applied on its surface to further improve its properties. Diamond coated steel parts are an option for many demanding industrial applications through prolonging the lifetime of steel parts, enhancement of tool performance as well as the reduction of wear rates. Direct deposition of diamond on steel using conventional chemical vapour deposition (CVD) processes is known to give poor results due to the preferential formation of amorphous carbon on iron, nickel and other elements as well as stresses induced from the significant difference in the thermal expansion coefficients of those materials. This article reports a novel approach of deposition of nanocrystalline diamond coatings on high-speed steel (M42) substrates using a multi-structured molybdenum (Mo) – tungsten (W) interlayer to form steel/Mo/Mo-W/W/diamond sandwich structures which overcome the adhesion problem related to direct magnetron sputtering deposition of pure tungsten. Surface, interface and tribology properties were evaluated to understand the role of such an interlayer structure. The multi-structured Mo-W interlayer has been proven to improve the adhesion between diamond films and steel substrates by acting as an effective diffusion barrier during the CVD diamond deposition.

  7. On the combined gradient-stochastic plasticity model: Application to Mo-micropillar compression

    SciTech Connect (OSTI)

    Konstantinidis, A. A.; Zhang, X.; Aifantis, E. C.

    2015-02-17

    A formulation for addressing heterogeneous material deformation is proposed. It is based on the use of a stochasticity-enhanced gradient plasticity model implemented through a cellular automaton. The specific application is on Mo-micropillar compression, for which the irregularities of the strain bursts observed have been experimentally measured and theoretically interpreted through Tsallis' q-statistics.

  8. Magnetic Force Microscopy Study of Zr2Co11 -Based Nanocrystalline Materials: Effect of Mo Addition

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

    Yue, Lanping; Jin, Yunlong; Zhang, Wenyong; Sellmyer, David J.

    2015-01-01

    Tmore » he addition of Molybdenum was used to modify the nanostructure and enhance coercivity of rare-earth-free Zr2Co11-based nanocrystalline permanent magnets. he effect of Mo addition on magnetic domain structures of melt spun nanocrystalline Zr16Co84-xMox(x=0, 0.5, 1, 1.5, and 2.0) ribbons has been investigated. It was found that magnetic properties and local domain structures are strongly influenced by Mo doping. he coercivity of the samples increases with the increase in Mo content (x≤1.5). he maximum energy product(BH)maxincreases with increasingxfrom 0.5 MGOe forx=0to a maximum value of 4.2 MGOe forx=1.5. he smallest domain size with a relatively short magnetic correlation length of 128 nm and largest root-mean-square phase shiftΦrmsvalue of 0.66° are observed for thex=1.5. he optimal Mo addition promotes magnetic domain structure refinement and thus leads to a significant increase in coercivity and energy product in this sample.« less

  9. Effect of mechanical strain on electronic properties of bulk MoS{sub 2}

    SciTech Connect (OSTI)

    Kumar, Sandeep Kumar, Jagdish Sastri, O. S. K. S.

    2015-05-15

    Ab-initio density functional theory based calculations of electronic properties of bulk and monolayer Molybdenum di-Sulfide (MoS{sub 2}) have been performed using all electron Full Potential Linearised Augmentad Plane Wave (FPLAPW) method using Elk code. We have used Generalised Gradient Approximation (GGA) for exchange and correlation functionals and performed calculaitons of Lattice parameters, Density Of States (DOS) and Band Structure (BS). Band structure calculations revealed that bulk MoS{sub 2} has indirect band gap of 0.97 eV and mono-layer MoS{sub 2} has direct band gap which has increased to 1.71 eV. These are in better agreement with experimental values as compared with the other calculations using pseudo-potential code. The effect of mechanical strain on the electronic properties of bulk MoS{sub 2} has also been studied. For the different values of compressive strain (varying from 2% to 8% in steps of 2%) along the c-axis, the corresponding DOS and BS are obtained. We observed that the band gap decreases by about 15% for every 2% increase in strain along the c-axis.

  10. Effect of Na-doped Mo on Selenization Pathways for CuGa/In Metallic Precursors

    SciTech Connect (OSTI)

    Krishnan, Rangarajan; Tong, Gabriel; Kim, Woo Kyoung; Payzant, E Andrew; Adelhelm, Christoph; Franzke, Enrico; Winkler, Jörg; Anderson, Timothy J

    2013-01-01

    Reaction pathways were followed for selenization of CuGa/In precursor structures using in-situ high temperature X-ray diffraction (HTXRD). Precursor films were deposited on Na-free and Na-doped Mo (3 and 5 at %)/Na-free glass. The precursor film was constituted with CuIn, In, Cu9Ga4, Cu3Ga, Cu16In9 and Mo. HTXRD measurements during temperature ramp selenization showed CIS formation occurs first, followed by CGS formation, and then mixing on the group III sub-lattice to form CIGS. CIGS formation was observed to be complete at ~450 C for samples deposited on 5 at % Na-doped Mo substrates. MoSe2 formation was evidenced after the CIGS synthesis reaction was complete. The Ga distribution in the annealed CIGS was determined by Rietveld refinement. Isothermal reaction studies were conducted for CIGS (112) formation in the temperature range 260-320 C to estimate the rate constants.

  11. Electric contributions to magnetic force microscopy response from graphene and MoS{sub 2} nanosheets

    SciTech Connect (OSTI)

    Li, Lu Hua Chen, Ying

    2014-12-07

    Magnetic force microscopy (MFM) signals have recently been detected from whole pieces of mechanically exfoliated graphene and molybdenum disulfide (MoS{sub 2}) nanosheets, and magnetism of the two nanomaterials was claimed based on these observations. However, non-magnetic interactions or artefacts are commonly associated with MFM signals, which make the interpretation of MFM signals not straightforward. A systematic investigation has been done to examine possible sources of the MFM signals from graphene and MoS{sub 2} nanosheets and whether the MFM signals can be correlated with magnetism. It is found that the MFM signals have significant non-magnetic contributions due to capacitive and electrostatic interactions between the nanosheets and conductive cantilever tip, as demonstrated by electric force microscopy and scanning Kevin probe microscopy analyses. In addition, the MFM signals of graphene and MoS{sub 2} nanosheets are not responsive to reversed magnetic field of the magnetic cantilever tip. Therefore, the observed MFM response is mainly from electric artefacts and not compelling enough to correlate with magnetism of graphene and MoS{sub 2} nanosheets.

  12. Interaction Layer Characteristics in U-xMo Dispersion/Monolithic Fuels

    SciTech Connect (OSTI)

    D. L. Porter

    2010-11-01

    Published data concerning the interaction layer (IL) formed between U-xMo fuel alloy and aluminum (Al)-based matrix or cladding materials was reviewed, including the effects of silicon (Si) content in the matrix/cladding, molybdenum (Mo) content in the fuel, pre irradiation thermal treatments, irradiation, and test temperature. The review revealed that tests conducted in the laboratory produce results different from those conducted in an irradiation environment. However, the laboratory testing relates well to thermal treatments performed prior to irradiation and helps in understanding the effects that these pre irradiation treatments have on in reactor performance. A pre-formed, Si-enriched IL seems to be important in delaying the onset of rapid growth of fission gas bubbles at low irradaiiation temperatures. Several other conclusions can be drawn: 1. An IL with phases akin to UAl3 is desired for optimum fuel performance, but at low temperatures, and especially in an irradiation atmosphere, the desired (Al+Si)/(U+Mo) ratio of three is difficult to produce. When the fuel operating temperature is low, it is important to create a pre-irradiation IL, enriched in Si. This pre-formed IL is relatively stable, performs well in terms of swelling resistance, and prevents rapid IL growth during irradiation. 2. At higher operating temperatures (>150–170°C), IL formation in reactor may not be so dependent on pre-irradiation IL formation, especially at high burnup; a pre-fabricated IL seems to be less stable at high burnup and high operating temperature. Moreover, the (Al+SI)/(U+Mo) ratio of three occurs more often at higher temperature. For these two reasons, it is important at high operating temperature to also have a matrix with significant Si content to create an IL in reactor with the right characteristics. 3. Out-of-reactor testing seems to indicate that Si in the matrix material is required in some concentration (2%, 5%, ?) to provide for a thin, Si-enriched IL formed

  13. Effects of Variations in Salt-Spray Conditions on the Corrosion Mechanisms of an AE44 Magnesium Alloy

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

    Martin, Holly J.; Horstemeyer, M. F.; Wang, Paul T.

    2010-01-01

    The understanding of how corrosion affects magnesium alloys is of utmost importance as the automotive and aerospace industries have become interested in the use of these lightweight alloys. However, the standardized salt-spray test does not produce adequate corrosion results when compared with field data, due to the lack of multiple exposure environments. This research explored four test combinations through three sets of cycles to determine how the corrosion mechanisms of pitting, intergranular corrosion, and general corrosion were affected by the environment. Of the four test combinations, Humidity-Drying was the least corrosive, while the most corrosive test condition was Salt Spray-Humidity-Drying.more » The differences in corrosivity of the test conditions are due to the various reactions needed to cause corrosion, including the presence of chloride ions to cause pit nucleation, the presence of humidity to cause galvanic corrosion, and the drying phase which trapped chloride ions beneath the corrosion by-products.« less

  14. Novel Processing of mo-si-b Intermetallics for improved efficiency of power systems

    SciTech Connect (OSTI)

    M.J. Kramer; O. Degirmen; A.J. Thom; M. Akinc

    2004-09-30

    Multiphase composite alloys based on the Mo-Si-B system are candidate materials for ultra-high temperature applications. In non load-bearing applications such as thermal barrier coatings or heat exchangers in fossil fuel burners, these materials may be ideally suited. Alloys based on the Mo{sub 5}Si{sub 3}B{sub x} phase (Tl phase) possess excellent oxidation resistance to at least 1600 C in synthetic air atmospheres. However, the ability of Tl-based alloys to resist aggressive combustion environments has not yet been determined. The present work seeks to investigate the resistance of these Mo-Si-B alloys to simulated combustion atmospheres. Material was pre-alloyed by combustion synthesis, and samples for testing were prepared by classic powder metallurgical processing techniques. Precursor material synthesized by self-heating-synthesis was sintered to densities exceeding 98% in an argon atmosphere at 1800 C. The approximate phase assemblage of the material was 57% Tl, 29% MoB, 14% MoSi{sub 2} (wt%). The alloy was oxidized from 1000-1100 C in flowing air containing water vapor at 18 Torr. At 1000 C the material achieved a steady state mass loss, and at 1100 C the material undergoes a steady state mass gain. The oxidation rate of these alloys in this temperature regime was accelerated by the presence of water vapor compared to oxidation in dry air. The results of microstructural analysis of the tested alloys will be discussed. Techniques and preliminary results for fabricating near-net-shaped parts will also be presented.

  15. Modeling of Interaction Layer Growth Between U-Mo Particles and an Al Matrix

    SciTech Connect (OSTI)

    Yeon Soo Kim; G. L. Hofman; Ho Jin Ryu; Jong Man Park; A. B. Robinson; D. M. Wachs

    2013-12-01

    Interaction layer growth between U-Mo alloy fuel particles and Al in a dispersion fuel is a concern due to the volume expansion and other unfavorable irradiation behavior of the interaction product. To reduce interaction layer (IL) growth, a small amount of Si is added to the Al. As a result, IL growth is affected by the Si content in the Al matrix. In order to predict IL growth during fabrication and irradiation, empirical models were developed. For IL growth prediction during fabrication and any follow-on heating process before irradiation, out-of-pile heating test data were used to develop kinetic correlations. Two out-of-pile correlations, one for the pure Al matrix and the other for the Al matrix with Si addition, respectively, were developed, which are Arrhenius equations that include temperature and time. For IL growth predictions during irradiation, the out-of-pile correlations were modified to include a fission-rate term to consider fission enhanced diffusion, and multiplication factors to incorporate the Si addition effect and the effect of the Mo content. The in-pile correlation is applicable for a pure Al matrix and an Al matrix with the Si content up to 8 wt%, for fuel temperatures up to 200 degrees C, and for Mo content in the range of 6 10wt%. In order to cover these ranges, in-pile data were included in modeling from various tests, such as the US RERTR-4, -5, -6, -7 and -9 tests and Koreas KOMO-4 test, that were designed to systematically examine the effects of the fission rate, temperature, Si content in Al matrix, and Mo content in U-Mo particles. A model converting the IL thickness to the IL volume fraction in the meat was also developed.

  16. The carburization of transition metal molybdates (MxMoO?, M= Cu, Ni or Co) and the generation of highly active metal/carbide catalysts for CO? hydrogenation

    SciTech Connect (OSTI)

    Rodriguez, Jose A.; Xu, Wenqian; Ramirez, Pedro J.; Stachiola, Dario; Brito, Joaquin L.

    2015-05-06

    A new approach has been tested for the preparation of metal/Mo?C catalysts using mixed-metal oxide molybdates as precursors. Synchrotron-based in situ time-resolved X-ray diffraction was used to study the reduction and carburization processes of Cu?(MoO?)?(OH)?, a-NiMoO? and CoMoO?nH?O by thermal treatment under mixtures of hydrogen and methane. In all cases, the final product was ?-Mo?C and a metal phase (Cu, Ni, or Co), but the transition sequence varied with the different metals, and it could be related to the reduction potential of the Cu?, Ni? and Co? cations inside each molybdate. The synthesized Cu/Mo?C, Ni/Mo?C and Co/Mo?C catalysts were highly active for the hydrogenation of CO?. The metal/Mo?C systems exhibited large variations in the selectivity towards methanol, methane and CnH?n?? (n > 2) hydrocarbons depending on the nature of the supported metal and its ability to cleave C-O bonds. Cu/Mo?C displayed a high selectivity for CO and methanol production. Ni/Mo?C and Co/Mo?C were the most active catalysts for the activation and full decomposition of CO?, showing high selectivity for the production of methane (Ni case) and CnH?n?? (n > 2) hydrocarbons (Co case).

  17. MoS{sub 2}@ZnO nano-heterojunctions with enhanced photocatalysis and field emission properties

    SciTech Connect (OSTI)

    Tan, Ying-Hua; Yu, Ke Li, Jin-Zhu; Fu, Hao; Zhu, Zi-Qiang

    2014-08-14

    The molybdenum disulfide (MoS{sub 2})@ZnO nano-heterojunctions were successfully fabricated through a facile three-step synthetic process: prefabrication of the ZnO nanoparticles, the synthesis of MoS{sub 2} nanoflowers, and the fabrication of MoS{sub 2}@ZnO heterojunctions, in which ZnO nanoparticles were uniformly self-assembled on the MoS{sub 2} nanoflowers by utilizing polyethyleneimine as a binding agent. The photocatalytic activities of the composite samples were evaluated by monitoring the photodegradation of methylene blue (MB). Compared with pure MoS{sub 2} nanoflowers, the composites show higher adsorption capability in dark and better photocatalytic efficiency due to the increased specific surface area and improved electron-hole pair separation. After irradiation for 100?min, the remaining MB in solution is about 7.3%. Moreover, the MoS{sub 2}@ZnO heterojunctions possess enhanced field emission properties with lower turn-on field of 3.08?V ?m{sup ?1}and lower threshold field of 6.9?V ?m{sup ?1} relative to pure MoS{sub 2} with turn-on field of 3.65?V ?m{sup ?1} and threshold field of 9.03?V ?m{sup ?1}.

  18. Microstructural Characterization of U-7Mo/Al-Si Alloy Matrix Dispersion Fuel Plates Fabricated at 500°C

    SciTech Connect (OSTI)

    Dennis D. Keiser, Jr.; Jan-Fong Jue; Bo Yao; Emmanuel Perez; Yongho Sohn; Curtis R. Clark

    2011-05-01

    The starting microstructure of a dispersion fuel plate will impact the overall performance of the plate during irradiation. To improve the understanding of the as-fabricated microstructures of U–Mo dispersion fuel plates, particularly the interaction layers that can form between the fuel particles and the matrix, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses have been performed on samples from depleted U–7Mo (U–7Mo) dispersion fuel plates with either Al–2 wt.% Si(Al–2Si) or AA4043 alloy matrix. It was observed that in the thick interaction layers, U(Al, Si)3 and U6Mo4Al43 were present, and in the thin interaction layers, (U, Mo) (Al, Si)3, U(Al, Si)4, U3Si3Al2, U3Si5, and possibly USi-type phases were observed. The U3Si3Al2 phase contained some Mo. Based on the results of this investigation, the time that a dispersion fuel plate is exposed to a relatively high temperature during fabrication will impact the nature of the interaction layers around the fuel particles. Uniformly thin, Si-rich layers will develop around the U–7Mo particles for shorter exposure times, and thicker, Si-depleted layers will develop for the longer exposure times.

  19. Theoretical study on strain induced variations in electronic properties of 2H-MoS{sub 2} bilayer sheets

    SciTech Connect (OSTI)

    Dong, Liang; Dongare, Avinash M.; Namburu, Raju R.; O'Regan, Terrance P.; Dubey, Madan

    2014-02-03

    The strain dependence of the electronic properties of bilayer sheets of 2H-MoS{sub 2} is studied using ab initio simulations based on density functional theory. An indirect band gap for bilayer MoS{sub 2} is observed for all variations of strain along the basal plane. Several transitions for the indirect band gap are observed for various strains for the bilayer structure. The variation of the band gap and the carrier effective masses for the holes and the electrons for the bilayer MoS{sub 2} structure under conditions of uniaxial strain, biaxial strain, as well as uniaxial stress is investigated.

  20. AMoRE: Collaboration for searches for the neutrinoless double-beta decay of the isotope of {sup 100}Mo with the aid of {sup 40}Ca{sup 100}MoO{sub 4} as a cryogenic scintillation detector

    SciTech Connect (OSTI)

    Khanbekov, N. D., E-mail: xanbekov@gmail.com [Institute of Theoretical and Experimental Physics (Russian Federation)

    2013-09-15

    The AMoRE (Advanced Mo based Rare process Experiment) Collaboration is planning to employ {sup 40}Ca{sup 100}MoO{sub 4} single crystals as a cryogenic Scintillation detector for studying the neutrinoless double-beta decay of the isotope {sup 100}Mo. A simultaneous readout of phonon and scintillation signals is performed in order to suppress the intrinsic background. The planned sensitivity of the experiment that would employ 100 kg of {sup 40}Ca{sup 100}MoO{sub 4} over five years of data accumulation would be T{sub 1/2}{sup 0{nu}} = 3 Multiplication-Sign 10{sup 26} yr, which corresponds to values of the effective Majorana neutrino mass in the range of Left-Pointing-Angle-Bracket m{sub {nu}} Right-Pointing-Angle-Bracket {approx} 0.02-0.06 eV.

  1. Analysis of irradiated U-7wt%Mo dispersion fuel microstructures using automated image processing

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

    Collette, R.; King, J.; Buesch, C.; Keiser, Jr., D. D.; Williams, W.; Miller, B. D.; Schulthess, J.

    2016-04-01

    The High Performance Research Reactor Fuel Development (HPPRFD) program is responsible for developing low enriched uranium (LEU) fuel substitutes for high performance reactors fueled with highly enriched uranium (HEU) that have not yet been converted to LEU. The uranium-molybdenum (U-Mo) fuel system was selected for this effort. In this study, fission gas pore segmentation was performed on U-7wt%Mo dispersion fuel samples at three separate fission densities using an automated image processing interface developed in MATLAB. Pore size distributions were attained that showed both expected and unexpected fission gas behavior. In general, it proved challenging to identify any dominant trends whenmore » comparing fission bubble data across samples from different fuel plates due to varying compositions and fabrication techniques. Here, the results exhibited fair agreement with the fission density vs. porosity correlation developed by the Russian reactor conversion program.« less

  2. Microstructure evolution in solution treated Ti15Mo alloy processed by high pressure torsion

    SciTech Connect (OSTI)

    Jane?ek, Milo; ?ek, Jakub; Strsk, Josef; Vclavov, Kristna; Hruka, Petr; Polyakova, Veronika; Gatina, Svetlana; Semenova, Irina

    2014-12-15

    Microstructure evolution and mechanical properties of ultra-fine grained Ti15Mo alloy processed by high pressure torsion were investigated. High pressure torsion straining resulted in strong grain refinement as-observed by transmission electron microscopy. Microhardness and light microscopy showed two distinct regions (i) a central region with radial material flow and low microhardness (340 HV) and (ii) a peripheral region with rotational material flow and high microhardness (430 HV). Positron annihilation spectroscopy showed that the only detectable defects in the material are dislocations, whose density increases with the radial distance and the number of high pressure torsion revolutions. The local chemical environment around defects does not differ significantly from the average composition. - Highlights: Beta-Ti alloy Ti15Mo was processed by high pressure torsion (HPT). Lateral inhomogeneity of the microstructure and microhardness was found. Dislocations are the only lattice defects detectable by positron annihilation. Molybdenum is not preferentially segregated along dislocation cores.

  3. Handbook for electron beam welding of 8-inch thick 2-1/4 Cr-1 Mo

    SciTech Connect (OSTI)

    Weber, Charles M.

    1980-08-01

    Purpose of this handbook is to provide a detailed procedure for electron beam welding 8 in. thick SA387 Grade 22 Class 2. Adherence to the procedure will allow others to produce electron beam welds in 8 in. thick 2-1/4 Cr-1 Mo. A justification or description of the effects of alterations of the welding procedure is not included in this report. These effects, along with a metallographic characterization and the mechanical properties produced by the welding procedure, etc., are described in report DOE/10244-10, Electron Beam Welding of 8-in. thick 2-1/4 Cr-1 Mo, Final Report under Contract DE-AC05-77OR10244.

  4. Bimetallic Nb-Mo carbide hydroprocessing catalysts: Synthesis, characterization, and activity studies

    SciTech Connect (OSTI)

    Yu, C.C.; Ramanathan, S.; Dhandapani, B.; Oyama, S.T.; Chen, J.G.

    1997-01-23

    A series of bimetallic carbides, Nb{sub 1.0}Mo{sub x}OC (x = 0.67-2.0), hydroprocessing catalysts, were synthesized from oxide precursors and were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure, elemental analysis, CO chemisorption, surface area measurements, and temperature-programmed reduction. The catalysts were active for quinoline hydrodenitrogenation and showed highest hydrodesulfurization at Nb{sub 1.0}Mo{sub 1.75}OC. The bimetallic compounds showed enhancement in activity and stability as compared with their monometallic carbides. The spent catalysts did not show any sulfide, oxide, or metal peaks, indicating that the catalysts were stable and tolerant to sulfur. 35 refs., 10 figs., 5 tabs.

  5. Improved performance of U-Mo dispersion fuel by Si addition in Al matrix.

    SciTech Connect (OSTI)

    Kim, Y S; Hofman, G L

    2011-06-01

    The purpose of this report is to collect in one publication and fit together work fragments presented in many conferences in the multi-year time span starting 2002 to the present dealing with the problem of large pore formation in U-Mo/Al dispersion fuel plates first observed in 2002. Hence, this report summarizes the excerpts from papers and reports on how we interpreted the relevant results from out-of-pile and in-pile tests and how this problem was dealt with. This report also provides a refined view to explain in detail and in a quantitative manner the underlying mechanism of the role of silicon in improving the irradiation performance of U-Mo/Al.

  6. LANL Experience Rolling Zr-Clad LEU-10Mo Foils for AFIP-7

    SciTech Connect (OSTI)

    Hammon, Duncan L.; Clarke, Kester D.; Alexander, David J.; Kennedy, Patrick K.; Edwards, Randall L.; Duffield, Andrew N.; Dombrowski, David E.

    2015-05-29

    The cleaning, canning, rolling and final trimming of Low Enriched Uranium-10 wt. pct. Molybdenum (LEU-10Mo) foils for ATR (Advanced Test Reactor) fuel plates to be used in the AFIP-7 (ATR Full Size Plate In Center Flux Trap Position) experiments are summarized. Six Zr-clad foils were produced from two LEU-10Mo castings supplied to Los Alamos National Laboratory (LANL) by Y-12 National Security Complex. Details of cleaning and canning procedures are provided. Hot- and cold-rolling results are presented, including rolling schedules, images of foils in-process, metallography and local compositions of regions of interest, and details of final foil dimensions and process yield. This report was compiled from the slides for the presentation of the same name given by Duncan Hammon on May 12, 2011 at the AFIP-7 Lessons Learned meeting in Salt Lake City, UT, with Los Alamos National Laboratory document number LA-UR 11-02898.

  7. A multiscale method for the analysis of defect behavior in MO during electron irradiation

    SciTech Connect (OSTI)

    Rest, J.; Insepov, Z.; Ye, B.; Yun, D.

    2014-10-01

    In order to overcome a lack of experimental information on values for key materials properties and kinetic coefficients, a multiscale modeling approach is applied to defect behavior in irradiated Mo where key materials properties, such as point defect (vacancy and interstitial) migration enthalpies as well as kinetic factors such as dimer formation, defect recombination, and self interstitial–interstitial loop interaction coefficients, are obtained by molecular dynamics calculations and implemented into rate-theory simulations of defect behavior. The multiscale methodology is validated against interstitial loop growth data obtained from electron irradiation of pure Mo. It is shown that the observed linear behavior of the loop diameter vs. the square root of irradiation time is a direct consequence of the 1D migration of self-interstitial atoms.

  8. Determination of the direct double- β -decay Q value of Zr 96 and atomic masses of Zr 90 <mo>-> 92 <mo>,> 94 <mo>,> 96 and Mo 92 <mo>,> 94 <mo>-> 98 <mo>,> 100

    SciTech Connect (OSTI)

    Gulyuz, K.; Ariche, J.; Bollen, G.; Bustabad, S.; Eibach, M.; Izzo, C.; Novario, S. J.; Redshaw, M.; Ringle, R.; Sandler, R.; Schwarz, S.; Valverde, A. A.

    2015-05-06

    Experimental searches for neutrinoless double-β decay offer one of the best opportunities to look for physics beyond the standard model. Detecting this decay would confirm the Majorana nature of the neutrino, and a measurement of its half-life can be used to determine the absolute neutrino mass scale. Important to both tasks is an accurate knowledge of the Q value of the double-β decay. The LEBIT Penning trap mass spectrometer was used for the first direct experimental determination of the ⁹⁶Zr double-β decay Q value: Qββ=3355.85(15) keV. This value is nearly 7 keV larger than the 2012 Atomic Mass Evaluation [M. Wang et al., Chin. Phys. C 36, 1603 (2012)] value and one order of magnitude more precise. The 3-σ shift is primarily due to a more accurate measurement of the ⁹⁶Zr atomic mass: m(⁹⁶Zr)=95.90827735(17) u. Using the new Q value, the 2νββ-decay matrix element, |M|, is calculated. Improved determinations of the atomic masses of all other zirconium (90-92,94,96Zr) and molybdenum (92,94-98,100Mo) isotopes using both ¹²C₈ and ⁸⁷Rb as references are also reported.

  9. Graphitic encapsulation of MgO and Fe{sub 3}C nanoparticles in the reaction of iron pentacarbonyl with magnesium

    SciTech Connect (OSTI)

    Dyjak, Sławomir; Cudziło, Stanisław; Polański, Marek; Budner, Bogusław; Bystrzycki, Jerzy

    2013-07-15

    A simple method to produce highly ordered carbon nanostructures by combustion synthesis is presented. Graphite-encapsulated magnesium oxide, iron carbide nanoparticles and carbon nanobelts were synthesized by the one-step reduction of iron pentacarbonyl with magnesium. High-resolution transmission electron microscopy analysis of the products revealed nanocrystalline MgO and Fe{sub 3}C particles surrounded by a well-crystallized, tight graphite film. The possible formation mechanism is presented and discussed. - Highlights: • We present a simple method to produce highly ordered carbon nanostructures by combustion synthesis. • The cubic MgO particles are completely coated by tight graphitic shells. • The mechanism of formation a distant carbon film on MgO surface has been discussed. • The presented method can be applied to synthesis of other core-shell structures.

  10. NNSA Works to Establish a Reliable Supply of Mo-99 Produced Without Highly

    National Nuclear Security Administration (NNSA)

    Enriched Uranium | National Nuclear Security Administration | (NNSA) NNSA Works to Establish a Reliable Supply of Mo-99 Produced Without Highly Enriched Uranium October 29, 2014 As part of its nuclear nonproliferation mission, and in support of the American Medical Isotopes Production Act of 2012 (AMIPA), the Department of Energy's National Nuclear Security Administration (DOE/NNSA) is working to develop a reliable and sustainable means of producing the life-saving medical isotope

  11. Chemical isolation of .sup.82 Sr from proton-irradiated Mo targets

    DOE Patents [OSTI]

    Grant, Patrick M.; Kahn, Milton; O'Brien, Jr., Harold A.

    1976-01-01

    Spallation reactions are induced in Mo targets with 200-800 MeV protons to produce microcurie to millicurie amounts of a variety of radionuclides. A six-step radiochemical procedure, incorporating precipitation, solvent extractions, and ion exchange techniques, has been developed for the separation and purification of Sr radioactivities from other spallation products and the bulk target material. Radiostrontium can be quantitatively recovered in a sufficiently decontaminated state for use in biomedical generator development.

  12. High strength Sn-Mo-Nb-Zr alloy tubes and method of making same

    DOE Patents [OSTI]

    Cheadle, Brian A.

    1977-01-01

    Tubes for use in nuclear reactors fabricated from a quaternary alloy comprising 2.5-4.0 wt% Sn, 0.5-1.5 wt% Mo, 0.5-1.5 wt% Nb, balance essentially Zr. The tubes are fabricated by a process of hot extrusion, heat treatment, cold working to size and age hardening, so as to produce a microstructure comprising elongated .alpha. grains with an acicular transformed .beta. grain boundary phase.

  13. Production and Characterization of Atomized U-Mo Powder by the Rotating Electrode Process

    SciTech Connect (OSTI)

    C.R. Clark; B.R. Muntifering; J.F. Jue

    2007-09-01

    In order to produce feedstock fuel powder for irradiation testing, the Idaho National Laboratory has produced a rotating electrode type atomizer to fabricate uranium-molybdenum alloy fuel. Operating with the appropriate parameters, this laboratory-scale atomizer produces fuel in the desired size range for the RERTR dispersion experiments. Analysis of the powder shows a homogenous, rapidly solidified microstructure with fine equiaxed grains. This powder has been used to produce irradiation experiments to further test adjusted matrix U-Mo dispersion fuel.

  14. Co-Rolled U10Mo/Zirconium-Barrier-Layer Monolithic Fuel Foil Fabrication Process

    SciTech Connect (OSTI)

    G. A. Moore; M. C. Marshall

    2010-01-01

    Integral to the current UMo fuel foil processing scheme being developed at Idaho National Laboratory (INL) is the incorporation of a zirconium barrier layer for the purpose of controlling UMo-Al interdiffusion at the fuel-meat/cladding interface. A hot “co-rolling” process is employed to establish a ~25-µm-thick zirconium barrier layer on each face of the ~0.3-mm-thick U10Mo fuel foil.

  15. Crystal structure of the spin-glass pyrochlore, Y/sub 2/Mo/sub 2/O/sub 7/

    SciTech Connect (OSTI)

    Reimers, J.N.; Greedan, J.E.; Sato, M.

    1988-02-01

    The crystal structure of the spin-glass material, Y/sub 2/Mo/sub 2/O/sub 7/, has been determined from powder neutron diffraction data using profile (Rietveld) methods. The data are consistent with the fully ordered cubic pyrochlore structure, a/sub 0/ = 10.230(1) A with Y in 16d, Mo in 16c, O in 48f(x = 0.3382(1), and O' in 8b of Fd3m. Attempts to refine models with O' disordered over the 32e sites or between the 8a and 8b sites resulted in convergence to the 8b positions. Derived Y-O and Mo-O distances are in excellent agreement with those found in isostructural materials giving indirect evidence for Y-Mo ordering over the cation sites.

  16. DEGRADATION OF SM2ZR2O7 THERMAL BARRIER COATING CAUSED BY CALCIUM-MAGNESIUM-ALUMINUM-SILICON OXIDE (CMAS) DEPOSITION

    SciTech Connect (OSTI)

    Wang, Honglong; Sheng, Zhizhi; Tarwater, Emily; Zhang, Xingxing; Dasgupta, Sudip; Fergus, Jeffrey

    2015-03-16

    Rare earth zirconates are promising materials for use as thermal barrier coatings in gas turbine engines. Among the lanthanide zirconate materials, Sm2Zr2O7 with the pyrochlore structure has lower thermal conductivity and better corrosion resistance against calcium-magnesium-aluminum-silicon oxide (CMAS). In this work, after reaction with CMAS, the pyrochlore structure transforms to the cubic fluorite structure and Ca2Sm8(SiO4)6O2 forms in elongated grain.

  17. Tribological properties of self-lubricating NiAl/Mo-based composites containing AgVO{sub 3} nanowires

    SciTech Connect (OSTI)

    Liu, Eryong; Gao, Yimin; Bai, Yaping; Yi, Gewen; Wang, Wenzhen; Zeng, Zhixiang; Jia, Junhong

    2014-11-15

    Silver vanadate (AgVO{sub 3}) nanowires were synthesized by hydrothermal method and self-lubricating NiAl/Mo-AgVO{sub 3} composites were fabricated by powder metallurgy technique. The composition and microstructure of NiAl/Mo-based composites were characterized and the tribological properties were investigated from room temperature to 900 C. The results showed that NiAl/Mo-based composites were consisted of nanocrystalline B2 ordered NiAl matrix, Al{sub 2}O{sub 3}, Mo{sub 2}C, metallic Ag and vanadium oxide phase. The appearance of metallic Ag and vanadium oxide phase can be attributed to the decomposition of AgVO{sub 3} during sintering. Wear testing results confirmed that NiAl/Mo-based composites have excellent tribological properties over a wide temperature range. For example, the friction coefficient and wear rate of NiAl/Mo-based composites containing AgVO{sub 3} were significantly lower than the composites containing only metallic Mo or AgVO{sub 3} lubricant when the temperature is above 300 C, which can be attributed to the synergistic lubricating action of metallic Mo and AgVO{sub 3} lubricants. Furthermore, Raman results indicated that the composition on the worn surface of NiAl-based composites was self-adjusted after wear testing at different temperatures. For example, Ag{sub 3}VO{sub 4} and Fe{sub 3}O{sub 4} lubricants were responsible for the improvement of tribological properties at 500 C, AgVO{sub 3}, Ag{sub 3}VO{sub 4} and molybdate for 700 C, and AgVO{sub 3} and molybdate for 900 C of NiAl-based composites with the addition of metallic Mo and AgVO{sub 3}. - Highlights: NiAl/Mo-AgVO{sub 3} nanocomposites were prepared by mechanical alloying and sintering. AgVO{sub 3} decomposed to metallic Ag and vanadium oxide during the sintering process. NiAl/Mo-AgVO{sub 3} exhibited superior tribological properties at a board temperature range. Phase composition on the worn surface was varied with temperatures. Self-adjusted action was responsible

  18. Exciton-dominated dielectric function of atomically thin MoS2 films

    SciTech Connect (OSTI)

    Yu, Yiling; Yu, Yifei; Cai, Yongqing; Li, Wei; Gurarslan, Alper; Peelaers, Hartwin; Aspnes, David E.; Van de Walle, Chris G.; Nguyen, Nhan V.; Zhang, Yong -Wei; Cao, Linyou

    2015-11-24

    We systematically measure the dielectric function of atomically thin MoS2 films with different layer numbers and demonstrate that excitonic effects play a dominant role in the dielectric function when the films are less than 5–7 layers thick. The dielectric function shows an anomalous dependence on the layer number. It decreases with the layer number increasing when the films are less than 5–7 layers thick but turns to increase with the layer number for thicker films. We show that this is because the excitonic effect is very strong in the thin MoS2 films and its contribution to the dielectric function may dominate over the contribution of the band structure. We also extract the value of layer-dependent exciton binding energy and Bohr radius in the films by fitting the experimental results with an intuitive model. The dominance of excitonic effects is in stark contrast with what reported at conventional materials whose dielectric functions are usually dictated by band structures. Lastly, the knowledge of the dielectric function may enable capabilities to engineer the light-matter interactions of atomically thin MoS2 films for the development of novel photonic devices, such as metamaterials, waveguides, light absorbers, and light emitters.

  19. Exciton-dominated dielectric function of atomically thin MoS2 films

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

    Yu, Yiling; Yu, Yifei; Cai, Yongqing; Li, Wei; Gurarslan, Alper; Peelaers, Hartwin; Aspnes, David E.; Van de Walle, Chris G.; Nguyen, Nhan V.; Zhang, Yong -Wei; et al

    2015-11-24

    We systematically measure the dielectric function of atomically thin MoS2 films with different layer numbers and demonstrate that excitonic effects play a dominant role in the dielectric function when the films are less than 5–7 layers thick. The dielectric function shows an anomalous dependence on the layer number. It decreases with the layer number increasing when the films are less than 5–7 layers thick but turns to increase with the layer number for thicker films. We show that this is because the excitonic effect is very strong in the thin MoS2 films and its contribution to the dielectric function maymore » dominate over the contribution of the band structure. We also extract the value of layer-dependent exciton binding energy and Bohr radius in the films by fitting the experimental results with an intuitive model. The dominance of excitonic effects is in stark contrast with what reported at conventional materials whose dielectric functions are usually dictated by band structures. Lastly, the knowledge of the dielectric function may enable capabilities to engineer the light-matter interactions of atomically thin MoS2 films for the development of novel photonic devices, such as metamaterials, waveguides, light absorbers, and light emitters.« less

  20. Study on Shielding Requirements for Radioactive Waste Transportation in a Mo-99 Production Plant - 13382

    SciTech Connect (OSTI)

    Melo Rego, Maria Eugenia de; Kazumi Sakata, Solange; Vicente, Roberto; Hiromoto, Goro

    2013-07-01

    Brazil is currently planning to produce {sup 99}Mo from fission of low enriched uranium (LEU) targets. The planned end of irradiation activity of {sup 99}Mo is about 185 TBq (5 kCi) per week to meet the present domestic demand of {sup 99m}Tc generators. The radioactive wastes from the production plant will be transferred to a waste treatment facility at the same site. The total activity of the actinides, fission and activation products present in the wastes can be predicted based on the yields of fission and activation data for the irradiation conditions, such as composition and mass of uranium targets, irradiation time, neutron flux, production schedule, etc., which were in principle already established by the project management. The transportation of the wastes from the production plant to the treatment facility will be done by means of special shielded packages. An assessment of the shielding required for the packages has been done and the results are presented here, aiming at contributing to the design of the waste management facility for the {sup 99}Mo production plant. (authors)

  1. Gate controlled electronic transport in monolayer MoS{sub 2} field effect transistor

    SciTech Connect (OSTI)

    Zhou, Y. F.; Wang, B.; Yu, Y. J.; Wei, Y. D. E-mail: jianwang@hku.hk; Xian, H. M.; Wang, J. E-mail: jianwang@hku.hk

    2015-03-14

    The electronic spin and valley transport properties of a monolayer MoS{sub 2} are investigated using the non-equilibrium Green's function formalism combined with density functional theory. Due to the presence of strong Rashba spin orbit interaction (RSOI), the electronic valence bands of monolayer MoS{sub 2} are split into spin up and spin down Zeeman-like texture near the two inequivalent vertices K and K′ of the first Brillouin zone. When the gate voltage is applied in the scattering region, an additional strong RSOI is induced which generates an effective magnetic field. As a result, electron spin precession occurs along the effective magnetic field, which is controlled by the gate voltage. This, in turn, causes the oscillation of conductance as a function of the magnitude of the gate voltage and the length of the gate region. This current modulation due to the spin precession shows the essential feature of the long sought Datta-Das field effect transistor (FET). From our results, the oscillation periods for the gate voltage and gate length are found to be approximately 2.2 V and 20.03a{sub B} (a{sub B} is Bohr radius), respectively. These observations can be understood by a simple spin precessing model and indicate that the electron behaviors in monolayer MoS{sub 2} FET are both spin and valley related and can easily be controlled by the gate.

  2. Supercondutivity at 9K in Mo5PB2 with evidence for multiple gaps

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

    McGuire, Michael A.; Parker, David S.

    2016-02-09

    Superconductivity is observed with critical temperatures near 9 K in the tetragonal compound Mo5PB2. This material adopts the Cr5B3 structure type common to superconducting Nb5Si3–xBx, Mo5SiB2, and W5SiB2, which have critical temperatures of 5.8–7.8 K. We have synthesized polycrystalline samples of the compound, made measurements of electrical resistivity, magnetic susceptibility, and heat capacity, and performed first-principles electronic structure calculations. The highest Tc value (9.2 K) occurs in slightly phosphorus rich samples, with composition near Mo5P1.1B1.9, and the upper critical field Hc2 at T = 0 is estimated to be ≈17 kOe. Together, the measurements and band-structure calculations indicate intermediate couplingmore » (λ=1.0), phonon mediated superconductivity. Here, the temperature dependence of the heat capacity and upper critical field Hc2 below Tc suggest multiple superconducting gaps may be present.« less

  3. Electrical properties of a-C:Mo films produced by dual-cathode filtered cathodic arc plasma deposition

    SciTech Connect (OSTI)

    Sansongsiri, Sakon; Anders, Andre; Yodsombat, Banchob

    2008-01-20

    Molybdenum-containing amorphous carbon (a-C:Mo) thin films were prepared using a dual-cathode filtered cathodic arc plasma source with a molybdenum and a carbon (graphite) cathode. The Mo content in the films was controlled by varying the deposition pulse ratio of Mo and C. Film sheet resistance was measured in situ at process temperature, which was close to room temperature, as well as ex situ as a function of temperature (300-515 K) in ambient air. Film resistivity and electrical activation energy were derived for different Mo and C ratios and substrate bias. Film thickness was in the range 8-28 nm. Film resistivity varied from 3.55x10-4 Omega m to 2.27x10-6 Omega m when the Mo/C pulse ratio was increased from 0.05 to 0.4, with no substrate bias applied. With carbon-selective bias, the film resistivity was in the range of 4.59x10-2 and 4.05 Omega m at a Mo/C pulse ratio of 0.05. The electrical activation energy decreased from 3.80x10-2 to 3.36x10-4 eV when the Mo/C pulse ratio was increased in the absence of bias, and from 0.19 to 0.14 eV for carbon-selective bias conditions. The resistivity of the film shifts systematically with the amounts of Mo and upon application of substrate bias voltage. The intensity ratio of the Raman D-peak and G-peak (ID/IG) correlated with the pre-exponential factor (sigma 0) which included charge carrier density and density of states.

  4. Two-dimensional GaSe/MoSe2 misfit bilayer heterojunctions by van der Waals epitaxy

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

    Li, Xufan; Lin, Ming-Wei; Lin, Junhao; Huang, Bing; Puretzky, Alexander A.; Ma, Cheng; Wang, Kai; Zhou, Wu; Pantelides, Sokrates T.; Chi, Miaofang; et al

    2016-04-01

    Two-dimensional (2D) heterostructures hold the promise for future atomically-thin electronics and optoelectronics due to their diverse functionalities. While heterostructures consisting of different transition metal dichacolgenide monolayers with well-matched lattices and novel physical properties have been successfully fabricated via van der Waals (vdW) or edge epitaxy, constructing heterostructures from monolayers of layered semiconductors with large lattice misfits still remains challenging. Here, we report the growth of monolayer GaSe/MoSe2 heterostructures with large lattice misfit by two-step chemical vapor deposition (CVD). Both vertically stacked and lateral heterostructures are demonstrated. The vertically stacked GaSe/MoSe2 heterostructures exhibit vdW epitaxy with well-aligned lattice orientation between themore » two layers, forming an incommensurate vdW heterostructure. However, the lateral heterostructures exhibit no lateral epitaxial alignment at the interface between GaSe and MoSe2 crystalline domains. Instead of a direct lateral connection at the boundary region where the same lattice orientation is observed between GaSe and MoSe2 monolayer domains in lateral GaSe/MoSe2 heterostructures, GaSe monolayers are found to overgrow MoSe2 during CVD, forming a stripe of vertically stacked vdW heterostructure at the crystal interface. Such vertically-stacked vdW GaSe/MoSe2 heterostructures are shown to form p-n junctions with effective transport and separation of photo-generated charge carriers between layers, resulting in a gate-tunable photovoltaic response. In conclusion, these GaSe/MoSe2 vdW heterostructures should have applications as gate-tunable field-effect transistors, photodetectors, and solar cells.« less

  5. Superconducting and structural properties of {delta}-MoC{sub 0.681} cubic molybdenum carbide phase

    SciTech Connect (OSTI)

    Sathish, C.I. [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan) [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan); Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Guo, Yanfeng, E-mail: GUO.Yanfeng@nims.go.jp [Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)] [Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Wang, Xia [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan) [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan); Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Tsujimoto, Yoshihiro [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)] [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Li, Jun [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan) [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan); Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Zhang, Shoubao [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)] [International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Matsushita, Yoshitaka [Synchrotron X-ray Station at SPring-8, National Institute for Materials Science, 1-1-1 Kouto, Sayo-cho, Hyogo 679-5148 (Japan)] [Synchrotron X-ray Station at SPring-8, National Institute for Materials Science, 1-1-1 Kouto, Sayo-cho, Hyogo 679-5148 (Japan); Shi, Youguo; Tian, Huanfang; Yang, Huaixin; Li, Jianqi [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)] [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Yamaura, Kazunari, E-mail: YAMAURA.Kazunari@nims.go.jp [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan) [Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810 (Japan); Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

    2012-12-15

    The superconducting and lattice properties of {delta}-MoC{sub 0.681} were studied by electromagnetic measurements, synchrotron X-ray diffraction, neutron diffraction, and electron diffraction. The superconducting properties (T{sub c}=12 K) of {delta}-MoC{sub 0.681} were well characterized by a weak coupling model. The carbon vacancies present in the host cubic structure were found to be robust, although the material was synthesized from stoichiometric carbon and Mo powder under a high-pressure of 6 GPa. A thermodynamically-stable structure with ordered vacancies did not account for the robust features of {delta}-MoC{sub 0.681} since the vacancies are unlikely to be ordered in long range in the host structure. A model based on inherent phonon instability theoretically predicted for a stoichiometric MoC phase might be responsible for the robust features of {delta}-MoC{sub 0.681}. - Graphical Abstract: The cubic molybdenum carbide shows an excellent superconductivity with robust carbon vacancies. Inherent phonon instability theoretically predicted for a stoichiometric MoC phase might be responsible for the vacancies rather than a thermodynamically-stable structure with vacancies ordering. Highlights: Black-Right-Pointing-Pointer The 12 K superconductivity is well characterized by a weakly coupling model. Black-Right-Pointing-Pointer Carbon vacancies are robust and disordered in the cubic host structure. Black-Right-Pointing-Pointer Inherent phonon instability might be responsible for the robust carbon vacancies in {delta}-MoC{sub 0.681}.

  6. Low-frequency 1/f noise in MoS{sub 2} transistors: Relative contributions of the channel and contacts

    SciTech Connect (OSTI)

    Renteria, J.; Jiang, C.; Samnakay, R.; Rumyantsev, S. L.; Goli, P.; Balandin, A. A.; Shur, M. S.

    2014-04-14

    We report on the results of the low-frequency (1/f, where f is frequency) noise measurements in MoS{sub 2} field-effect transistors revealing the relative contributions of the MoS{sub 2} channel and Ti/Au contacts to the overall noise level. The investigation of the 1/f noise was performed for both as fabricated and aged transistors. It was established that the McWhorter model of the carrier number fluctuations describes well the 1/f noise in MoS{sub 2} transistors, in contrast to what is observed in graphene devices. The trap densities extracted from the 1/f noise data for MoS{sub 2} transistors, are 2??10{sup 19}?eV{sup ?1}cm{sup ?3} and 2.5??10{sup 20}?eV{sup ?1}cm{sup ?3} for the as fabricated and aged devices, respectively. It was found that the increase in the noise level of the aged MoS{sub 2} transistors is due to the channel rather than the contact degradation. The obtained results are important for the proposed electronic applications of MoS{sub 2} and other van der Waals materials.

  7. Preparation of Al{sub 2}O{sub 3}/Mo nanocomposite powder via chemical route and spray drying

    SciTech Connect (OSTI)

    Lo, M.; Cheng, F.; Wei, W.J.

    1996-08-01

    A route to prepare nanometer-sized Mo particulates in Al{sub 2}O{sub 3} was attempted by a combination of solution reactions in molecular scale and forcing precipitation by a spray-drying technique. MoO{sub 3} was first dissolved in ammonia water and then added in the slurry with high purity, submicrometer Al{sub 2}O{sub 3} powder. Mixed suspension was spray-dried, and then the dried granules were reduced by hydrogen gas and further hot-pressing to a bulky composite at various temperatures. Dissolution of Mo oxide, adsorption reactions on alumina surface, and surface potential of alumina particles in homogeneous ammonia suspension were studied. Characterization of the granules, including compactability, flowing properties, surface morphology, grain growth of Mo and Al{sub 2}O{sub 3}, and mixing homogeneity, were examined. Homogeneity of the spray-dried granules was determined by the calculation of mixing index and the observation of the microstructure of sintered body. The existence of intergranular, intragranular, and nanosized Mo particulates within Al{sub 2}O{sub 3} grains was observed by transmission electron microscopy (TEM). All the evidences revealed that homogeneous composites with nanometer-sized Mo had been successfully prepared by this attempt with the proposed chemical route and following spray-drying process. {copyright}{ital 1996 Materials Research Society.}

  8. Kinetic study of hydrogen evolution reaction on Ni{sub 30} Mo{sub 70}, Co{sub 30}Mo{sub 70}, Co{sub 30}Ni{sub 70} and Co{sub 10}Ni{sub 20}Mo{sub 70} alloy electrodes

    SciTech Connect (OSTI)

    Dominguez-Crespo, M.A.; Plata-Torres, M.; Torres-Huerta, A.M.; Arce-Estrada, E.M. . E-mail: earce@ipn.mx; Hallen-Lopez, J.M.

    2005-07-15

    The hydrogen evolution reaction on nanocrystalline Ni{sub 30}Mo{sub 70}, Co{sub 30}Mo{sub 70}, Co{sub 30}Ni{sub 70}, and Co{sub 10}Ni{sub 20}Mo{sub 70}, metallic powders prepared by mechanical alloying was investigated with linear polarization and ac impedance methods, in 30 wt.% KOH aqueous solution at room temperature. The formation process and structural properties of these nanocrystalline materials were characterized by X-ray diffraction and transmission electron microscopy. Alloyed powders showed the presence of two phases: an fcc solid solution and intermetallic compounds of Ni, Co and Mo. Based on polarization and ac impedance measurements, an improved electrocatalytic activity for hydrogen evolution reaction was observed in mechanically alloyed Co{sub 30}Ni{sub 70} powders, which is slightly higher than milled metallic Ni powders.

  9. Characterization of few-layer 1T-MoSe{sub 2} and its superior performance in the visible-light induced hydrogen evolution reaction

    SciTech Connect (OSTI)

    Gupta, Uttam; Naidu, B. S.; Maitra, Urmimala; Rao, C. N. R.; Singh, Anjali; Shirodkar, Sharmila N.; Waghmare, Umesh V.

    2014-09-01

    Based on earlier results on the photocatalytic properties of MoS{sub 2}, the 1T form of MoSe{sub 2}, prepared by lithium intercalation and exfoliation of bulk MoSe{sub 2}, has been employed for the visible-light induced generation of hydrogen. 1T-MoSe{sub 2} is found to be superior to both 2H and 1T MoS{sub 2} as well as 2H-MoSe{sub 2} in producing hydrogen from water, the yield being in the 6075 mmol?h{sup ?1}?g{sup ?1} range with a turn over frequency of 1519 h{sup ?1}. First principles calculations reveal that 1T-MoSe{sub 2} has a lower work function than 2H-MoSe{sub 2} as well as 1T and 2H-MoS{sub 2}, making it easier to transfer an electron from 1T-MoSe{sub 2} for the production of H{sub 2}.

  10. Li3Mo4P5O24: A two-electron cathode for lithium-ion batteries with three-dimensional diffusion pathways

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

    Wen, Bohua; Khalifah, Peter G.; Liu, Jue; Chernova, Natasha A.; Wang, Xiaoya; Janssen, Yuri; Omenya, Fredrick; Whittingham, M. Stanley

    2016-03-05

    The structure of the novel compound Li3Mo4P5O24 has been solved from single crystal X-ray diffraction data. The Mo cations in Li3Mo4P5O24 are present in four distinct types of MoO6 octahedra, each of which has one open vertex at the corner participating in a Mo=O double bond and whose other five corners are shared with PO4 tetrahedra. On the basis of a bond valence sum difference map (BVS-DM) analysis, this framework is predicted to support the facile diffusion of Li+ ions, a hypothesis that is confirmed by electrochemical testing data, which show that Li3Mo4P5O24 can be utilized as a rechargeable batterymore » cathode material. It is found that Li can both be removed from and inserted into Li3Mo4P5O24. The involvement of multiple redox processes occurring at the same Mo site is reflected in electrochemical plateaus around 3.8 V associated with the Mo6+/Mo5+ redox couple and 2.2 V associated with the Mo5+/Mo4+ redox couple. The two-electron redox properties of Mo cations in this structure lead to a theoretical capacity of 198 mAh/g. When cycled between 2.0 and 4.3 V versus Li+/Li, an initial capacity of 113 mAh/g is observed with 80% of this capacity retained over the first 20 cycles. Lastly, this compound therefore represents a rare example of a solid state cathode able to support two-electron redox capacity and provides important general insights about pathways for designing next-generation cathodes with enhanced specific capacities.« less

  11. A practical grinding-assisted dry synthesis of nanocrystalline NiMoO{sub 4} polymorphs for oxidative dehydrogenation of propane

    SciTech Connect (OSTI)

    Chen Miao; Wu Jialing; Liu Yongmei; Cao Yong; Guo Li; He Heyong; Fan Kangnian

    2011-12-15

    A practical two-stage reactive grinding-assisted pathway waste-free and cost-effective for the synthesis of NiMoO{sub 4} has been successfully developed. It was demonstrated that proper design in synthetic strategy for grinding plays a crucial role in determining the ultimate polymorph of NiMoO{sub 4}. Specifically, direct grinding (DG) of MoO{sub 3} and NiO rendered {alpha}-NiMoO{sub 4} after annealing, whereas sequential grinding (SG) of the two independently pre-ground oxides followed by annealing generated {beta}-NiMoO{sub 4} solid solution. Characterizations in terms of Raman and X-ray diffraction suggest the creation of {beta}-NiMoO{sub 4} precursor in the latter alternative is the key aspect for the formation of {beta}-NiMoO{sub 4}. The DG-derived {alpha}-NiMoO{sub 4} tested by oxidative dehydrogenation of propane exhibited superior activity in contrast to its analog synthesized via conventional coprecipitation. It is suggested that the favorable chemical composition facilely obtained via grinding in contrast to that by coprecipitation was essential for achieving a more selective production of propylene. - Graphical Abstract: Grinding-assisted synthesis of NiMoO{sub 4} offers higher and more reproducible activities in contrast to coprecipitation for oxidative dehydrogenation of propane, and both {alpha}- and {beta}-NiMoO{sub 4} can be synthesized. Highlights: Black-Right-Pointing-Pointer NiMoO{sub 4} was prepared through grinding-assisted pathway. Black-Right-Pointing-Pointer Direct/sequential grinding rendered {alpha}-, {beta}-NiMoO{sub 4}, respectively. Black-Right-Pointing-Pointer Grinding-derived {alpha}-NiMoO{sub 4} showed high and reproducible activity for oxidative dehydrogenation of propane.

  12. Transmission Electron Microscope In Situ Straining Technique to Directly Observe Defects and Interfaces During Deformation in Magnesium

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

    Morrow, Benjamin M.; Cerreta, E. K.; McCabe, R. J.; Tomé, C. N.

    2015-05-14

    In-situ straining was used to study deformation behavior of hexagonal close-packed (hcp) metals.Twinning and dislocation motion, both essential to plasticity in hcp materials, were observed.Typically, these processes are characterized post-mortem by examining remnant microstructural features after straining has occurred. By imposing deformation during imaging, direct observation of active deformation mechanisms is possible. This work focuses on straining of structural metals in a transmission electron microscope (TEM), and a recently developed technique that utilizes familiar procedures and equipment to increase ease of experiments. In-situ straining in a TEM presents several advantages over conventional post-mortem characterization, most notably time-resolution of deformation andmore » streamlined identification of active deformation mechanisms. Drawbacks to the technique and applicability to other studies are also addressed. In-situ straining is used to study twin boundary motion in hcp magnesium. A {101¯2} twin was observed during tensile and compressive loading. Twin-dislocation interactions are directly observed. Notably, dislocations are observed to remain mobile, even after multiple interactions with twin boundaries, a result which suggests that Basinki’s dislocation transformation mechanism by twinning is not present in hcp metals. The coupling of in-situ straining with traditional post-mortem characterization yields more detailed information about material behavior during deformation than either technique alone.« less

  13. Mechanical properties and microstructures of a magnesium alloy gas tungsten arc welded with a cadmium chloride flux

    SciTech Connect (OSTI)

    Zhang, Z.D.; Liu, L.M. Shen, Y.; Wang, L.

    2008-01-15

    Gas tungsten arc (GTA) welds were prepared on 5-mm thick plates of wrought magnesium AZ31B alloy, using an activated flux. The microstructural characteristics of the weld joint were investigated using optical and scanning microscopy, and the fusion zone microstructure was compared with that of the base metal. The elemental distribution was also investigated by electron probe microanalysis (EPMA). Mechanical properties were determined by standard tensile tests on small-scale specimens. The as-welded fusion zone prepared using a CdCl{sub 2} flux exhibited a larger grain size than that prepared without flux; the microstructure consisted of matrix {alpha}-Mg, eutectic {alpha}-Mg and {beta}-Al{sub 12}Mg{sub 17}. The HAZ was observed to be slightly wider for the weld prepared with a CdCl{sub 2} flux compared to that prepared without flux; thus the tensile strength was lower for the flux-prepared weld. The fact that neither Cd nor Cl was detected in the weld seam by EPMA indicates that the CdCl{sub 2} flux has a small effect on convection in the weld pool.

  14. Film Breakdown and Nano-Porous Mg(OH)2 Formation from Corrosion of Magnesium Alloys in Salt Solutions

    SciTech Connect (OSTI)

    Brady, Michael P; Rother, Gernot; Anovitz, Lawrence {Larry} M; Littrell, Ken; Unocic, Kinga A; Elsentriecy, Hassan H; Song, GuangLing; Thomson, Jeffery K; Gallego, Nidia C; Davis, Dr. Bruce

    2015-01-01

    Small angle neutron scattering (SANS) and cross-section scanning transmission electron microscopy (STEM) were used to study film formation by magnesium alloys AZ31B (Mg-3Al-1Zn base) and ZE10A (Elektron 717, E717: Mg-1Zn + Nd, Zr) in H2O and D2O with and without 1 or 5 wt.% NaCl. No SANS scattering changes were observed after 24 h D2O or H2O exposures compared with unreacted alloy, consistent with relatively dense MgO-base film formation. However, exposure to 5 wt.% NaCl resulted in accelerated corrosion, with resultant SANS scattering changes detected. The SANS data indicated both particle and rough surface scattering, but with no preferential size features. The films formed in 5 wt.% NaCl consisted of a thin, inner MgO-base layer, and a nano-porous and filamentous Mg(OH)2 outer region tens of microns thick. Chlorine was detected extending to the inner MgO-base film region, with segregation of select alloying elements also observed in the inner MgO, but not the outer Mg(OH)2. Modeling of the SANS data suggested that the outer Mg(OH)2 films had very high surface areas, consistent with loss of film protectiveness. Implications for the NaCl corrosion mechanism, and the potential utility of SANS for Mg corrosion, are discussed.

  15. Transmission Electron Microscope In Situ Straining Technique to Directly Observe Defects and Interfaces During Deformation in Magnesium

    SciTech Connect (OSTI)

    Morrow, Benjamin M.; Cerreta, E. K.; McCabe, R. J.; Tom, C. N.

    2015-05-14

    In-situ straining was used to study deformation behavior of hexagonal close-packed (hcp) metals.Twinning and dislocation motion, both essential to plasticity in hcp materials, were observed.Typically, these processes are characterized post-mortem by examining remnant microstructural features after straining has occurred. By imposing deformation during imaging, direct observation of active deformation mechanisms is possible. This work focuses on straining of structural metals in a transmission electron microscope (TEM), and a recently developed technique that utilizes familiar procedures and equipment to increase ease of experiments. In-situ straining in a TEM presents several advantages over conventional post-mortem characterization, most notably time-resolution of deformation and streamlined identification of active deformation mechanisms. Drawbacks to the technique and applicability to other studies are also addressed. In-situ straining is used to study twin boundary motion in hcp magnesium. A {1012} twin was observed during tensile and compressive loading. Twin-dislocation interactions are directly observed. Notably, dislocations are observed to remain mobile, even after multiple interactions with twin boundaries, a result which suggests that Basinkis dislocation transformation mechanism by twinning is not present in hcp metals. The coupling of in-situ straining with traditional post-mortem characterization yields more detailed information about material behavior during deformation than either technique alone.

  16. Transmission Electron Microscope In Situ Straining Technique to Directly Observe Defects and Interfaces During Deformation in Magnesium

    SciTech Connect (OSTI)

    Morrow, Benjamin M.; Cerreta, E. K.; McCabe, R. J.; Tomé, C. N.

    2015-05-14

    In-situ straining was used to study deformation behavior of hexagonal close-packed (hcp) metals.Twinning and dislocation motion, both essential to plasticity in hcp materials, were observed.Typically, these processes are characterized post-mortem by examining remnant microstructural features after straining has occurred. By imposing deformation during imaging, direct observation of active deformation mechanisms is possible. This work focuses on straining of structural metals in a transmission electron microscope (TEM), and a recently developed technique that utilizes familiar procedures and equipment to increase ease of experiments. In-situ straining in a TEM presents several advantages over conventional post-mortem characterization, most notably time-resolution of deformation and streamlined identification of active deformation mechanisms. Drawbacks to the technique and applicability to other studies are also addressed. In-situ straining is used to study twin boundary motion in hcp magnesium. A {101¯2} twin was observed during tensile and compressive loading. Twin-dislocation interactions are directly observed. Notably, dislocations are observed to remain mobile, even after multiple interactions with twin boundaries, a result which suggests that Basinki’s dislocation transformation mechanism by twinning is not present in hcp metals. The coupling of in-situ straining with traditional post-mortem characterization yields more detailed information about material behavior during deformation than either technique alone.

  17. Effects of Potassium Doping on CO Hydrogenation Over MoS2 Catalysts: A First-Principles Investigation

    SciTech Connect (OSTI)

    Andersen, Amity; Kathmann, Shawn M.; Lilga, Michael A.; Albrecht, Karl O.; Hallen, Richard T.; Mei, Donghai

    2014-07-01

    Periodic density functional theory calculations were performed to explore the effects of doping potassium (K) on the reactivity of CO hydrogenation to mixed higher alcohols over MoS2 catalysts. We found that the doped K species over the model MoS2(100) catalyst surface acts as a unique site for CO adsorption where either the K-C or the K-O bonding is allowed. The charge transfer from the K 4s electron to the conduction band of the MoS2(100) surface slightly enhances CO adsorption at the edge Mo sites. Due to the large electropositive nature, the presence of the surface K species, however, will hinder the dissociative adsorption of hydrogen. As a result, the doping K species drive CO hydrogenation selectivity toward the C2+ alcohols instead of hydrocarbons by increasing CO and decreasing hydrogen coverages on the MoS2 catalysts. To further elucidate the effect of doping K on the shifting of the selectivity toward CO hydrogenation, we calculated several key reaction steps leading to the H2CCO precursor formation, i.e., CO hydrogenation, the C-O bond scission and the C-C coupling (CH2+CO). The C-C coupling step is favorable for both the Mo and S edges. However, the undoped S edge has an overall more thermodynamically favorable reaction profile up to C-O scission compared with the Mo edge. This work was funded by a CRADA project (No. PNNL/297) with Range Fuels. The research was performed using EMSL, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. The work involving the results analysis and mansucript writing was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences.

  18. Martensitic transformation behaviors of rapidly solidified TiNiMo powders

    SciTech Connect (OSTI)

    Kim, Yeon-wook

    2012-10-15

    For the fabrication of bulk near-net-shape shape memory alloys and porous metallic biomaterials, consolidation of TiNiMo alloy powders is more useful than that of elemental powders of Ti, Ni and Mo. Ti{sub 50}Ni{sub 49.9}Mo{sub 0.1} shape memory alloy powders were prepared by gas atomization, and transformation temperatures and microstructures of those powders were investigated as a function of powder size. XRD analysis showed that the B2RB19 martensitic transformation occurred in powders smaller than 150 ?m. According to DSC analysis of the as-atomized powders, the B2R transformation temperature (T{sub R}) of the 2550 ?m powders was 18.4 C. The T{sub R} decreased with increasing powder size, however, the difference in T{sub R} between 2550 ?m powders and 100150 ?m powders is only 1 C. Evaluation of powder microstructures was based on SEM examination of the surface and the polished and etched powder cross sections and the typical images of the rapidly solidified powders showed cellular morphology. Porous cylindrical foams of 10 mm diameter and 1.5 mm length were fabricated by spark plasma sintering (SPS) at 800 C and 5 MPa. Finally these porous TiNi alloy samples are heat-treated for 1 h at 850 C, and then quenched in ice water. The bulk samples have 23% porosity and 4.6 g/cm{sup 3} density and their T{sub R} is 17.8 C.

  19. MO: ZL

    Office of Legacy Management (LM)

    2. "Radiological Survey of the Ashland Oil Co. (Former Waist Property), Tonewanda, Kew ... It should be noted that a nearby second property belonging to Ashland Oil Company is not ...

  20. Hydrofining of Athabasca derived heavy gas oil over Ni-W and Co-Mo catalysts

    SciTech Connect (OSTI)

    Mann, R.S.; Diaz-real, R.

    1987-01-01

    The hydrotreatment of heavy gas oil derived from Athabasca bitumen was studied in a trickle bed reactor over Ni-W and Co-Mo zeolite catalyst at 350-425/sup 0/C, 3.55 to 10.44 MPa, and LHSV of 1-4. The effects of temperature and liquid flow rates on the product were investigated. ASTM distillation, aniline point, viscosities and densities of the product oil were measured and correlated with various parameters. Activity of the catalysts for hydrodenitrogenation is compared.

  1. Corrosion and degradation of a polyurethane/Co-Ni-Cr-Mo pacemaker lead

    SciTech Connect (OSTI)

    Sung, P.; Fraker, A.C.

    1987-12-01

    An investigation to study changes in the metal surfaces and the polyurethane insulation of heart pacemaker leads under controlled in vitro conditions was conducted. A polyurethane (Pellethane 2363-80A)/Co-Ni-Cr-Mo (MP35N) wire lead was exposed in Hanks' physiological saline solution for 14 months and then analyzed using scanning electron microscopy, x-ray energy dispersive analysis, and small angle x-ray scattering. Results showed that some leakage of solution into the lead had occurred and changes were present on both the metal and the polyurethane surfaces.

  2. FULL SIZE U-10MO MONOLITHIC FUEL FOIL AND FUEL PLATE FABRICATION-TECHNOLOGY DEVELOPMENT

    SciTech Connect (OSTI)

    G. A. Moore; J-F Jue; B. H. Rabin; M. J. Nilles

    2010-03-01

    Full-size U10Mo foils are being developed for use in high density LEU monolithic fuel plates. The application of a zirconium barrier layer too the foil is applied using a hot co-rolling process. Aluminum clad fuel plates are fabricated using Hot Isostatic Pressing (HIP) or a Friction Bonding (FB) process. An overview is provided of ongoing technology development activities, including: the co-rolling process, foil shearing/slitting and polishing, cladding bonding processes, plate forming, plate-assembly swaging, and fuel plate characterization. Characterization techniques being employed include, Ultrasonic Testing (UT), radiography, and microscopy.

  3. Pairing correlations and thermodynamical quantities in {sup 96,97}Mo

    SciTech Connect (OSTI)

    Kargar, Z.

    2007-06-15

    The nuclear level densities of {sup 96,97}Mo are calculated in the framework of superconducting theory. The parameters of nuclear level density are so chosen that the saddle point conditions are satisfied and the best fit to the experimental data yields. Then, using these parameters the energy, the entropy and the spin cut-off factor are calculated as a function of temperature. The curves show structures, reflecting the phase transition from a correlated to an uncorrelated phase. The critical temperature for quenching of pairing correlations is found at T{sub c}{approx}0.7-0.9 MeV.

  4. In Situ Time-Resolved Characterization of Novel Cu-MoO2 Catalysts During the Water-Gas Shift Reaction

    SciTech Connect (OSTI)

    Wen ,W.; Liu, J.; White, M.; Marinkovic, N.; Hanson, J.; Rodriguez, J.

    2007-01-01

    A novel and active Cu-MoO{sub 2} catalyst was synthesized by partial reduction of a precursor CuMoO{sub 4} mixed-metal oxide with CO or H{sub 2} at 200-250 C. The phase transformations of Cu-MoO{sub 2} during H{sub 2} reduction and the water-gas shift reaction could be followed by In situ time resolved XRD techniques. During the reduction process the diffraction pattern of the CuMoO{sub 4} collapsed and the copper metal lines were observed on an amorphous material background that was assigned to molybdenum oxides. During the first pass of water-gas shift (WGS) reaction, diffraction lines for Cu{sub 6}Mo{sub 5}O{sub 18} and MoO{sub 2} appeared around 350 C and Cu{sub 6}Mo{sub 5}O{sub 18} was further transformed to Cu/MoO{sub 2} at higher temperature. During subsequent passes, significant WGS catalytic activity was observed with relatively stable plateaus in product formation around 350, 400 and 500 C. The interfacial interactions between Cu clusters and MoO{sub 2} increased the water-gas shift catalytic activities at 350 and 400 C.

  5. Extraordinary selectivity of CoMo{sub 3}S{sub 13} chalcogel for C{sub 2}H{sub 6} and CO{sub 2} adsorption.

    SciTech Connect (OSTI)

    Shafaei-Fallah, M.; Rothenberger, Z.; Katsoulidis, A. P.; He, J.; Malliakas, C. D.; Kanatzidis, M. G.

    2011-11-09

    The chalcogel CoMo{sub 3}S{sub 13} is obtained from the reaction of (NH{sub 4}){sub 2}[Mo{sub 3}S{sub 13}] with cobalt acetate in solution. The chalcogel has a BET surface area of 570 m{sup 2} g{sup -1}, and pair distribution function analysis (PDF) and infrared spectroscopy indicate that the [Mo{sub 3}S{sub 13}]{sup 2-} cluster is a building block in the porous network. The CoMo{sub 3}S{sub 13} chalcogel exhibits high selectivity for separating ethane and carbon dioxide from hydrogen and methane.

  6. Defect-mediated transport and electronic irradiation effect in individual domains of CVD-grown monolayer MoS2

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

    Durand, Corentin; Zhang, Xiaoguang; Fowlkes, Jason; Najmaei, Sina; Lou, Jun; Li, An -Ping

    2015-01-16

    We study the electrical transport properties of atomically thin individual crystalline grains of MoS2 with four-probe scanning tunneling microscopy. The monolayer MoS2 domains are synthesized by chemical vapor deposition on SiO2/Si substrate. Temperature dependent measurements on conductance and mobility show that transport is dominated by an electron charge trapping and thermal release process with very low carrier density and mobility. The effects of electronic irradiation are examined by exposing the film to electron beam in the scanning electron microscope in an ultrahigh vacuum environment. The irradiation process is found to significantly affect the mobility and the carrier density of themore » material, with the conductance showing a peculiar time-dependent relaxation behavior. It is suggested that the presence of defects in active MoS2 layer and dielectric layer create charge trapping sites, and a multiple trapping and thermal release process dictates the transport and mobility characteristics. The electron beam irradiation promotes the formation of defects and impact the electrical properties of MoS2. Finally, our study reveals the important roles of defects and the electron beam irradiation effects in the electronic properties of atomic layers of MoS2.« less

  7. Advanced characterization study of commercial conversion and electrocoating structures on magnesium alloys AZ31B and ZE10A

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

    Brady, Michael P.; Leonard, Donovan N.; Meyer, III, Harry M.; Song, Guang -Ling; Kitchen, Kris; Davis, Bruce; Thompson, J. K.; Unocic, K. A.; Elsentriecy, H. H.

    2016-03-31

    The local metal-coating interface microstructure and chemistry formed on commercial magnesium alloys Mg–3Al–1Zn (AZ31B) and Mg–1Zn–0.25Zr–<0.5Nd (ZE10A, ZEK100 type) were analyzed as-chemical conversion coated with a commercial hexafluoro-titanate/zirconate type + organic polymer based treatment (Bonderite® 5200) and a commercial hexafluoro-zirconate type + trivalent chromium Cr3 + type treatment (Surtec® 650), and after the same conversion coatings followed by electrocoating with an epoxy based coating, Cathoguard® 525. Characterization techniques included scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and cross-section scanning transmission electron microscopy (STEM). Corrosion behavior was assessed in room temperature saturated aqueous Mg(OH)2 solution with 1 wt.% NaCl. Themore » goal of the effort was to assess the degree to which substrate alloy additions become enriched in the conversion coating, and how the conversion coating was impacted by subsequent electrocoating. Key findings included the enrichment of Al from AZ31B and Zr from ZE10A, respectively, into the conversion coating, with moderate corrosion resistance benefits for AZ31B when Al was incorporated. Varying degrees of increased porosity and modification of the initial conversion coating chemistry at the metal-coating interface were observed after electrocoating. These changes were postulated to result in degraded electrocoating protectiveness. As a result, these observations highlight the challenges of coating Mg, and the need to tailor electrocoating in light of potential degradation of the initial as-conversion coated Mg alloy surface.« less

  8. Film breakdown and nano-porous Mg(OH)2 formation from corrosion of magnesium alloys in salt solutions

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

    Brady, M. P.; Rother, G.; L. M. Anovitz; Littrell, K. C.; Unocic, K. A.; Elsentriecy, H. H.; Song, G. -L.; Thomson, J. K.; Gallego, N. C.; Davis, B.

    2015-01-21

    In this paper, small angle neutron scattering (SANS) and scanning transmission electron microscopy (STEM) were used to study film formation by magnesium alloys AZ31B (Mg-3Al-1Zn base) and ZE10A (Elektron 717, E717: Mg-1Zn + Nd, Zr) in H2O and D2O with and without 1 or 5 wt% NaCl. No SANS scattering changes were observed after 24 h D2O or H2O exposures compared with as-received (unreacted) alloy, consistent with relatively dense MgO-base film formation. However, exposure to 5 wt% NaCl resulted in accelerated corrosion, with resultant SANS scattering changes detected. The SANS data indicated both particle and rough surface (internal and external)more » scattering, but with no preferential size features. The films formed in 5 wt% NaCl consisted of a thin, inner MgO-base layer, and a nano-porous and filamentous Mg(OH)2 outer region tens of microns thick. Chlorine was detected extending to the inner MgO-base film region, with segregation of select alloying elements also observed in the inner MgO, but not the outer Mg(OH)2. Modeling of the SANS data suggested that the outer Mg(OH)2 films had very high surface areas, consistent with loss of film protectiveness. Finally, implications for the NaCl corrosion mechanism, and the potential utility of SANS for Mg corrosion, are discussed.« less

  9. Low temperature synthesis of nanocrystalline magnesium aluminate with high surface area by surfactant assisted precipitation method: Effect of preparation conditions

    SciTech Connect (OSTI)

    Mosayebi, Zeinab; Rezaei, Mehran; Catalyst and Advanced Materials Research Laboratory, Chemical Engineering Department, Faculty of Engineering, University of Kashan, Kashan ; Hadian, Narges; Kordshuli, Fazlollah Zareie; Meshkani, Fereshteh

    2012-09-15

    Highlights: ► MgAl{sub 2}O{sub 4} showed a high surface area and nanocrystalline structure. ► Addition of polymeric surfactant affected the structural properties of MgAl{sub 2}O{sub 4}. ► MgAl{sub 2}O{sub 4} prepared with surfactant showed a hollow cylindrical shape. -- Abstract: A surfactant assisted co-precipitation method was employed for the low temperature synthesis of magnesium aluminate spinel with nanocrystalline size and high specific surface area. Pluronic P123 triblock copolymer and ammonia solution were used as surfactant and precipitation agent, respectively. The prepared samples were characterized by thermal gravimetric and differential thermal gravimetric analyses (TG/DTG), X-ray diffraction (XRD), N{sub 2} adsorption (BET) and transmission electron microscopy (TEM) techniques. The effects of several process parameters such as refluxing temperature, refluxing time, pH, P123 to metals mole ratio (P123/metals) and calcination temperature on the structural properties of the samples were investigated. The obtained results showed that, among the process parameters pH and refluxing temperature have a significant effect on the structural properties of samples. The results revealed that increase in pH from 9.5 to 11 and refluxing temperature from 40 °C to 80 °C increased the specific surface area of prepared samples in the range of 157–188 m{sup 2} g{sup −1} and 162–184 m{sup 2} g{sup −1}, respectively. The XRD analysis showed the single-phase MgAl{sub 2}O{sub 4} was formed at 700 °C.

  10. Experimental study of the electric dipole strength in the even Mo nuclei and its deformation dependence

    SciTech Connect (OSTI)

    Erhard, M.; Junghans, A. R.; Nair, C.; Schwengner, R.; Beyer, R.; Klug, J.; Kosev, K.; Wagner, A.; Grosse, E.

    2010-03-15

    Two methods based on bremsstrahlung were applied to the stable even Mo isotopes for the experimental determination of the photon strength function covering the high excitation energy range above 4 MeV with its increasing level density. Photon scattering was used up to the neutron separation energies S{sub n} and data up to the maximum of the isovector giant resonance (GDR) were obtained by photoactivation. After a proper correction for multistep processes the observed quasicontinuous spectra of scattered photons show a remarkably good match to the photon strengths derived from nuclear photoeffect data obtained previously by neutron detection and corrected in absolute scale by using the new activation results. The combined data form an excellent basis to derive a shape dependence of the E1 strength in the even Mo isotopes with increasing deviation from the N=50 neutron shell (i.e., with the impact of quadrupole deformation and triaxiality). The wide energy coverage of the data allows for a stringent assessment of the dipole sum rule and a test of a novel parametrization developed previously which is based on it. This parametrization for the electric dipole strength function in nuclei with A>80 deviates significantly from prescriptions generally used previously. In astrophysical network calculations it may help to quantify the role the p-process plays in cosmic nucleosynthesis. It also has impact on the accurate analysis of neutron capture data of importance for future nuclear energy systems and waste transmutation.

  11. Spin and valley transport in monolayers of MoS{sub 2}

    SciTech Connect (OSTI)

    Sun, J. F.; Cheng, F.

    2014-04-07

    We investigate theoretically quantum transport and Goos-Hnchen (GH) effect of electrons in a p-n-p junction on monolayers of MoS{sub 2}. We find that the transmission properties of spin-up (spin-down) electrons in K valley are the same with spin-down (spin-up) electrons in K? valley due to the time-reversal symmetry. The GH shifts for the transmitted K and K? beams in the n-p interface are in the opposite direction, and GH shifts for the spin-up and spin-down electron beams at the same valley have different values in the same direction due to the different group velocities. Therefore, the spin-up and spin-down electrons can be separated after passing a sufficiently long channel created by a p-n-p junction. These features provide us a new way to generate a fully spin- and valley-polarized current in monolayers of MoS{sub 2}.

  12. Raman shifts in electron-irradiated monolayer MoS2

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

    Parkin, William M.; Balan, Adrian; Liang, Liangbo; Das, Paul Masih; Lamparski, Michael; Naylor, Carl H.; Rodríguez-Manzo, Julio A.; Johnson, A. T. Charlie; Meunier, Vincent; Drndic, Marija

    2016-03-21

    Here, we report how the presence of electron-beam-induced sulfur vacancies affects first-order Raman modes and correlate the effects with the evolution of the in situ transmission-electron microscopy (TEM) two-terminal conductivity of monolayer MoS2 under electron irradiation. We observe a redshift in the E Raman peak and a less pronounced blueshift in the A'1 peak with increasing electron dose. Using energy-dispersive X-ray spectroscopy (EDS), we show that irradiation causes partial removal of sulfur and correlate the dependence of the Raman peak shifts with S vacancy density (a few %), which is confirmed by first-principles density functional theory calculations. In situ devicemore » current measurements show exponential decrease in channel current upon irradiation. Our analysis demonstrates that the observed frequency shifts are intrinsic properties of the defective systems and that Raman spectroscopy can be used as a quantitative diagnostic tool to characterize MoS2-based transport channels.« less

  13. On the bonding nature of electron states for the Fe-Mo double perovskite

    SciTech Connect (OSTI)

    Carvajal, E.; Cruz-Irisson, M.; Oviedo-Roa, R.; Navarro, O.

    2014-05-15

    The electronic transport as well as the effect of an external magnetic field has been investigated on manganese-based materials, spinels and perovskites. Potential applications of double perovskites go from magnetic sensors to electrodes in solid-oxide fuel cells; besides the practical interests, it is known that small changes in composition modify radically the physical properties of double perovskites. We have studied the Sr{sub 2}FeMoO{sub 6} double perovskite compound (SFMO) using first-principles density functional theory. The calculations were done within the generalized gradient approximation (GGA) scheme with the Perdew-Burke-Ernzerhof (PBE) functional. We have made a detailed analysis of each electronic state and the charge density maps around the Fermi level. For the electronic properties of SFMO it was used a primitive cell, for which we found the characteristic half-metallic behavior density of states composed by e{sub g} and t{sub 2g} electrons from Fe and Mo atoms. Those peaks were tagged as bonding or antibonding around the Fermi level at both, valence and conduction bands.

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

    SciTech Connect (OSTI)

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

    2008-05-14

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

  15. Localized Corrosion of a Neutron Absorbing Ni-Cr-Mo-Gd Alloy

    SciTech Connect (OSTI)

    R.E. Mizia; T. E. Lister; P. J. Pinhero; T. L. Trowbridge

    2005-04-01

    The National Spent Nuclear Fuel Program, located at the Idaho National Laboratory (INL), has developed a new nickel-chromium-molybdenum-gadolinium structural alloy for storage and long-term disposal of spent nuclear fuel (SNF). The new alloy will be used for SNF storage container inserts for nuclear criticality control. Gadolinium has been chosen as the neutron absorption alloying element due to its high thermal neutron absorption cross section. This alloy must be resistant to localized corrosion when exposed to postulated Yucca Mountain in-package chemistries. The corrosion resistance properties of three experimental heats of this alloy are presented. The alloys performance are be compared to Alloy 22 and borated stainless steel. The results show that initially the new Ni-Cr-Mo-Gd alloy is less resistant to corrosion as compared to another Ni-Cr-Mo-Gd alloy (Alloy 22); but when the secondary phase that contains gadolinium (gadolinide) is dissolved, the alloy surface becomes passive. The focus of this work is to qualify these gadolinium containing materials for ASME code qualification and acceptance in the Yucca Mountain Repository.

  16. Consent to Subcontracts on Management and Operating (M&O) Contracts

    Broader source: Energy.gov [DOE]

    This is to provide notice that an Acquisition Letter (AL) will be issued addressing the establishment of subcontract review thresholds on M&O contracts. Currently, DEAR 970.4401-1 and 970.4401-2 require Heads of the Contracting Activities (HCAs) to establish thresholds, by subcontract type and dollar level, for the review and approval of proposed subcontracting actions by each M&O contractor under their cognizance. The AL will seek to improve Consent to Subcontract efficiency and to ensure we apply our resources to those subcontract actions that truly pose the most risk. The AL will state that the HCA should determine appropriate tiers for subcontract review thresholds, as a result of a risk assessment. This tiered approach may result in different thresholds being established for different sites as well as different thresholds at a given site, taking into consideration the best interests of DOE and the following factors: approval status of the contractor's purchasing system results of Independent Peer Review Program for Contractors' Purchasing Systems (e.g., PERT results) results of Contractor Balanced Scorecard Self-assessment size, experience, ability, reliability, and organization of the contractor's purchasing function internal controls, procedures, and organizational stature of the contractor's purchasing function subcontract type (fixed price vs. cost reimbursement) degree of competition value nature of the work/complexity whether the subcontract needs special surveillance

  17. Spatially Resolved Photoexcited Charge-Carrier Dynamics in Phase-Engineered Monolayer MoS2

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

    Yamaguchi, Hisato; Blancon, Jean-Christophe; Kappera, Rajesh; Lei, Sidong; Najmaei, Sina; Mangum, Benjamin D.; Gupta, Gautam; Ajayan, Pulickel M.; Lou, Jun; Chhowalla, Manish; et al

    2015-01-27

    A fundamental understanding of the intrinsic optoelectronic properties of atomically thin transition metal dichalcogenides (TMDs) is crucial for its integration into high performance semiconductor devices. We investigate the transport properties of chemical vapor deposition (CVD) grown monolayer molybdenum disulfide (MoS2) under photo-excitation using correlated scanning photocurrent microscopy and photoluminescence imaging. We examined the effect of local phase transformation underneath the metal electrodes on the generation of photocurrent across the channel length with diffraction-limited spatial resolution. While maximum photocurrent generation occurs at the Schottky contacts of semiconducting (2H-phase) MoS2, after the metallic phase transformation (1T-phase), the photocurrent peak is observed towardsmore » the center of the device channel, suggesting a strong reduction of native Schottky barriers. Analysis using the bias and position dependence of the photocurrent indicates that the Schottky barrier heights are few meV for 1T- and ~200 meV for 2H-contacted devices. We also demonstrate that a reduction of native Schottky barriers in a 1T device enhances the photo responsivity by more than one order of magnitude, a crucial parameter in achieving high performance optoelectronic devices. The obtained results pave a pathway for the fundamental understanding of intrinsic optoelectronic properties of atomically thin TMDs where Ohmic contacts are necessary for achieving high efficiency devices with low power consumption.« less

  18. Analysis of a new MoO transition in the near-IR: A combined theoretical and experimental study

    SciTech Connect (OSTI)

    Harms, Jack C.; Womack, Kaitlin A.; O’Brien, Leah C.; Zou, Wenli

    2014-10-07

    The near-infrared electronic spectrum of MoO has been recorded in emission using the Fourier transform spectrometer associated with the National Solar Observatory at Kitt Peak, AZ. The gas phase MoO molecules were produced in a neon-based electric discharge using a molybdenum hollow cathode and a trace amount of oxygen. One MoO molecular band was observed in the spectrum with a red-degraded bandhead at 6735 cm{sup −1} and is assigned as the (0,0) band of the c {sup 3}Π{sub 1} − a {sup 3}Σ{sup −}{sub 0+} transition. The assignment is based upon isotopologue shifts and ab initio calculations. Results from the ab initio calculations and analysis are presented. The new calculations support the assignment of the observed transition and have led to reassignment of several electronic states from previous work.

  19. Spectroscopic signatures of AA' and AB stacking of chemical vapor deposited bilayer MoS2

    SciTech Connect (OSTI)

    Xia, Ming; Li, Bo; Yin, Kuibo; Capellini, Giovanni; Niu, Gang; Gong, Yongji; Zhou, Wu; Ajayan, Pulickel M.; Xie, Ya -Hong

    2015-11-04

    We discuss prominent resonance Raman and photoluminescence spectroscopic differences between AA'and AB stacked bilayer molybdenum disulfide (MoS2) grown by chemical vapor deposition are reported. Bilayer MoS2 islands consisting of the two stacking orders were obtained under identical growth conditions. Also, resonance Raman and photoluminescence spectra of AA' and AB stacked bilayer MoS2 were obtained on Au nanopyramid surfaces under strong plasmon resonance. Both resonance Raman and photoluminescence spectra show distinct features indicating clear differences in interlayer interaction between these two phases. The implication of these findings on device applications based on spin and valley degrees of freedom.

  20. Imaging findings and pharmacokinetics of 111-indium ZME-018 monoclonal antibody (MoAb) in malignant melanoma

    SciTech Connect (OSTI)

    Murray, J.L.; Rosenblum, M.; Lamki, L.; Haynie, T.P.; Glenn, H.; Jahns, M.; Plager, C.; Hersh, E.M.; Unger, M.; Carlo, D.L.

    1985-05-01

    13 patients with metastatic melanoma were studied using 5 mCi of In-111 labeled MoAb ZME-018 which reacts with GP 240 melanoma-associated antigen. The MoAb was infused over 2 h at doses of 2.5 mg (5 pts), 5 mg (5 pts), and 10 mg (3 pts). Total body tomograms and planar spot views with region of interest analysis were performed at 4, 24 and 72 hours post infusion. No adverse side effects were noted. There was rapid distribution to spleen, bone, bone marrow, liver, and testes. Tumor sites could be visualized as early as 24 hours but were more easily seen at 72 hours when the background activity was less. 20 of 46 (43%) previously documented metastases were identified. More sites imaged with increasing concentrations of MoAB, I.E., 25% at 2.5 mg; 67% at 5 mg; 70% at 10 mg. Tumor localization occurred in a significant number of patients especially at MoAb doses above 2.5 mg. In two instances, uptake of 111-In occurred in previously undiagnosed sites. The pharmacokinetics of MoAb were analyzed at each dose level. At the 5 mg dose, the terminal phase half-life for 111-In in plasma was 24.5 +- 2.7 hours. The apparent volume of distribution (Vd) was 4.03 +- 5iota similar to the plasma value, and the calculated clearance rate for 111-In label was 0.0259 + 0.002 ml/kg/min. Mean urinary excretion of 111-In label was 8.7 +- 0.6% of the administered dose over 48 hours after administration. The calculated pharmacokinetic parameters were independent of antibody dose. ZME 018 was cleared more rapidly from plasma, compared to previous studies with P97 antimelanoma MoAb.

  1. Preparation and immunoreactivity of high specific activity indium-111-DTPA labeled monoclonal antibody (MoAb) using ultrapure indium-111

    SciTech Connect (OSTI)

    Zoghbi, S.S.; Neumann, R.D.; Gottschalk, A.

    1986-10-01

    The preparation of high-specific activity /sup 111/In-DTPA-MoAb without increasing the number of DTPA molecules per Ab was investigated. Instant thin layer chromatography was used to assay the relationship between labeling efficiencies and specific activities. With ultrapurified /sup 111/In, the specific activity of the radiolabeled MoAb approached the expected theoretic maximum of 100 muCi/microgram. The bioactivity of such high-specific activity preparation showed no degradation as measured by in vitro cell binding assay.

  2. Comparison of Two Preparation Methods on Catalytic Activity and Selectivity of Ru-Mo/HZSM5 for Methane Dehydroaromatization

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

    Petkovic, Lucia M.; Ginosar, Daniel M.

    2014-01-01

    Catalytic performance of Mo/HZSM5 and Ru-Mo/HZSM5 catalysts prepared by vaporization-deposition of molybdenum trioxide and impregnation with ammonium heptamolybdate was analyzed in terms of catalyst activity and selectivity, nitrogen physisorption analyses, temperature-programmed oxidation of carbonaceous residues, and temperature-programmed reduction. Vaporization-deposition rendered the catalyst more selective to ethylene and coke than the catalyst prepared by impregnation. This result was assigned to lower interaction of molybdenum carbide with the zeolite acidic sites.

  3. Enhancing the photocurrent and photoluminescence of single crystal monolayer MoS{sub 2} with resonant plasmonic nanoshells

    SciTech Connect (OSTI)

    Sobhani, Ali [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Lauchner, Adam [Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States); Najmaei, Sina; Lou, Jun [Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States); Ayala-Orozco, Ciceron; Wen, Fangfang [Department of Chemistry, Rice University, Houston, Texas 77005 (United States); Halas, Naomi J., E-mail: halas@rice.edu [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States)

    2014-01-20

    Monolayer molybdenum disulfide (MoS{sub 2}) produced by controlled vapor-phase synthesis is a commercially promising new two-dimensional material for optoelectronics because of its direct bandgap and broad absorption in the visible and ultraviolet regimes. By tuning plasmonic core-shell nanoparticles to the direct bandgap of monolayer MoS{sub 2} and depositing them sparsely (<1% coverage) onto the material's surface, we observe a threefold increase in photocurrent and a doubling of photoluminescence signal for both excitonic transitions, amplifying but not altering the intrinsic spectral response.

  4. In situ phase transformation of Laves phase from Chi-phase in Mo-containing Fe–Cr–Ni alloys

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

    Tan, L.; Yang, Y.

    2015-11-01

    For an in situ phase transformation of the Chi (χ) phase to the Laves phase we observed in a Fe–Cr–Ni–Mo model alloy. The morphology, composition, and crystal structure of the χ and Laves phases, and their orientation relationship with the matrix austenite phase were investigated. The resulted Laves phase has larger lattice mismatch with the matrix phase than the χ phase, leading to the increase of local strain fields and the formation of dislocations. Moreover, this finding is helpful to understand the precipitation behavior of the intermetallic phases in the Mo-containing austenitic stainless steels.

  5. MoO3 as combined hole injection layer and tapered spacer in combinatorial multicolor microcavity organic light emitting diodes

    SciTech Connect (OSTI)

    Liu, R.; Xu, Chun; Biswas, Rana; Shinar, Joseph; Shinar, Ruth

    2011-09-01

    Multicolor microcavity ({mu}C) organic light-emitting diode (OLED) arrays were fabricated simply by controlling the hole injection and spacer MoO{sub 3} layer thickness. The normal emission was tunable from {approx}490 to 640 nm and can be further expanded. A compact, integrated spectrometer with two-dimensional combinatorial arrays of {mu}C OLEDs was realized. The MoO{sub 3} yields more efficient and stable devices, revealing a new breakdown mechanism. The pixel current density reaches {approx}4 A/cm{sup 2} and a maximal normal brightness {approx}140 000 Cd/m{sup 2}, which improves photoluminescence-based sensing and absorption measurements.

  6. Preparation and structural study from neutron diffraction data of Pr{sub 5}Mo{sub 3}O{sub 16}

    SciTech Connect (OSTI)

    Martinez-Lope, M.J.; Alonso, J.A.; Sheptyakov, D.; Pomjakushin, V.

    2010-12-15

    The title compound has been prepared as polycrystalline powder by thermal treatments of mixtures of Pr{sub 6}O{sub 11} and MoO{sub 2} in air. In the literature, an oxide with a composition Pr{sub 2}MoO{sub 6} has been formerly described to present interesting catalytic properties, but its true stoichiometry and crystal structure are reported here for the first time. It is cubic, isostructural with CdTm{sub 4}Mo{sub 3}O{sub 16} (space group Pn-3n, Z=8), with a=11.0897(1) A. The structure contains MoO{sub 4} tetrahedral units, with Mo-O distances of 1.788(2) A, fully long-range ordered with PrO{sub 8} polyhedra; in fact it can be considered as a superstructure of fluorite (M{sub 8}O{sub 16}), containing 32 MO{sub 2} fluorite formulae per unit cell, with a lattice parameter related to that of cubic fluorite (a{sub f}=5.5 A) as a{approx}2a{sub f}. A bond valence study indicates that Mo exhibits a mixed oxidation state between 5+ and 6+ (perhaps accounting for the excellent catalytic properties). One kind of Pr atoms is trivalent whereas the second presents a mixed Pr{sup 3+}-Pr{sup 4+} oxidation state. The similarity of the XRD pattern with that published for Ce{sub 2}MoO{sub 6} suggests that this compound also belongs to the same structural type, with an actual stoichiometry Ce{sub 5}Mo{sub 3}O{sub 16}. -- Graphical Abstract: Formerly formulated as Pr{sub 2}MoO{sub 6}, the title compound is a cubic superstructure of fluorite (a=11.0897(1) A, space group Pn-3n) due to the long-range ordering of PrO{sub 8} scalenohedra and MoO{sub 4} tetrahedral units, showing noticeable shifts of the oxygen positions in order to provide a tetrahedral coordination for Mo ions. A mixed valence Mo{sup 5+}-Mo{sup 6+} is identified, which could account for the excellent catalytic properties of this material. Display Omitted

  7. Toward epitaxially grown two-dimensional crystal hetero-structures: Single and double MoS{sub 2}/graphene hetero-structures by chemical vapor depositions

    SciTech Connect (OSTI)

    Lin, Meng-Yu [Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, Taiwan (China); Research Center for Applied Sciences, Academia Sinica, Nankang, Taipei, Taiwan (China); Chang, Chung-En [Department of Photonics, National Chiao-Tung University, Hsinchu, Taiwan (China); Wang, Cheng-Hung [Institute of Display, National Chiao-Tung University, Hsinchu, Taiwan (China); Su, Chen-Fung; Chen, Chi [Research Center for Applied Sciences, Academia Sinica, Nankang, Taipei, Taiwan (China); Lee, Si-Chen [Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, Taiwan (China); Lin, Shih-Yen, E-mail: shihyen@gate.sinica.edu.tw [Graduate Institute of Electronics Engineering, National Taiwan University, Taipei, Taiwan (China); Research Center for Applied Sciences, Academia Sinica, Nankang, Taipei, Taiwan (China); Department of Photonics, National Chiao-Tung University, Hsinchu, Taiwan (China)

    2014-08-18

    Uniform large-size MoS{sub 2}/graphene hetero-structures fabricated directly on sapphire substrates are demonstrated with layer-number controllability by chemical vapor deposition (CVD). The cross-sectional high-resolution transmission electron microscopy (HRTEM) images provide the direct evidences of layer numbers of MoS{sub 2}/graphene hetero-structures. Photo-excited electron induced Fermi level shift of the graphene channel are observed on the single MoS{sub 2}/graphene hetero-structure transistors. Furthermore, double hetero-structures of graphene/MoS{sub 2}/graphene are achieved by CVD fabrication of graphene layers on top of the MoS{sub 2}, as confirmed by the cross-sectional HRTEM. These results have paved the possibility of epitaxially grown multi-hetero-structures for practical applications.

  8. Energy-Saving Melting and Revert Reduction Technology (E-SMARRT): Lost Foam Thin Wall - Feasibility of Producing Lost Foam Castings in Aluminum and Magnesium Based Alloys

    SciTech Connect (OSTI)

    Fasoyinu, Yemi; Griffin, John A.

    2014-03-31

    With the increased emphasis on vehicle weight reduction, production of near-net shape components by lost foam casting will make significant inroad into the next-generation of engineering component designs. The lost foam casting process is a cost effective method for producing complex castings using an expandable polystyrene pattern and un-bonded sand. The use of un-bonded molding media in the lost foam process will impose less constraint on the solidifying casting, making hot tearing less prevalent. This is especially true in Al-Mg and Al-Cu alloy systems that are prone to hot tearing when poured in rigid molds partially due to their long freezing range. Some of the unique advantages of using the lost foam casting process are closer dimensional tolerance, higher casting yield, and the elimination of sand cores and binders. Most of the aluminum alloys poured using the lost foam process are based on the Al-Si system. Very limited research work has been performed with Al-Mg and Al-Cu type alloys. With the increased emphasis on vehicle weight reduction, and given the high-strength-to-weight-ratio of magnesium, significant weight savings can be achieved by casting thin-wall (≤ 3 mm) engineering components from both aluminum- and magnesium-base alloys.

  9. Role of Si on the Diffusional Interactions between U-Mo and Al-Si Alloys at 823 K (550 degrees C)

    SciTech Connect (OSTI)

    E. Perez; Y.H. Sohn; D.D. Keiser, Jr.

    2013-01-01

    U-Mo dispersions in Al-alloy matrix and monolithic fuels encased in Al-alloy are under development to fulfill the requirements for research and test reactors to use low-enriched molybdenum stabilized uranium alloys fuels. Significant interaction takes place between the U-Mo fuel and Al during manufacturing and in-reactor irradiation. The interactions products are Al-rich phases with physical and thermal characteristics that adversely affect fuel performance and lead to premature failure. Detailed analysis of the interdiffusion and microstructural development of this system was carried through diffusion couples consisting of U-7wt.%Mo, U-10wt.%Mo and U-12wt.%Mo in contact with pure Al, Al-2wt.%Si, and Al-5wt.%Si, annealed at 823K for 1, 5 and 20 hours. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed for the analysis. Diffusion couples consisting of U-Mo vs. pure Al contained UAl3, UAl4, U6Mo4Al43, and UMo2Al20 phases. The addition of Si to the Al significantly reduced the thickness of the interdiffusion zone. The interdiffusion zones developed Al and Si enriched regions, whose locations and size depended on the Si and Mo concentrations in the terminal alloys. In the couples, the (U,Mo)(Al,Si)3 phase was observed throughout interdiffusion zone, and the U6Mo4Al43 and UMo2Al20 phases were observed only where the Si concentrations were low.

  10. High-temperature behavior of dicesium molybdate Cs{sub 2}MoO{sub 4}: Implications for fast neutron reactors

    SciTech Connect (OSTI)

    Wallez, Gilles; Raison, Philippe E.; Smith, Anna L.; Clavier, Nicolas

    2014-07-01

    Dicesium molybdate (Cs{sub 2}MoO{sub 4})'s thermal expansion and crystal structure have been investigated herein by high temperature X ray diffraction in conjunction with Raman spectroscopy. This first crystal-chemical insight at high temperature is aimed at predicting the thermostructural and thermomechanical behavior of this oxide formed by the accumulation of Cs and Mo fission products at the periphery of nuclear fuel rods in sodium-cooled fast reactors. Within the temperature range of the fuel's rim, Cs{sub 2}MoO{sub 4} becomes hexagonal P6{sub 3}/mmc, with disordered MoO{sub 4} tetrahedra and 2D distribution of CsO bonds that makes thermal axial expansion both large (50??{sub l}?70 10{sup ?6} C{sup ?1}, 500800 C) and highly anisotropic (?{sub c}??{sub a}=6710{sup ?6} C{sup ?1}, hexagonal form). The difference with the fuel's expansion coefficient is of potential concern with respect to the cohesion of the Cs{sub 2}MoO{sub 4} surface film and the possible release of cesium radionuclides in accidental situations. - Graphical abstract: The weakness of the CsO bonds and the disordering of the MoO{sub 4} tetrahedra array in the high-temperature form are responsible for the huge thermal expansion of Cs{sub 2}MoO{sub 4} along the c-axis. - Highlights: Thermomechanical behavior of Cs{sub 2}MoO{sub 4} fission products compound is studied. High-temperature form of Cs{sub 2}MoO{sub 4} is characterized by XRD and Raman. Thermal expansion appears very high and anisotropic. Cohesion between Cs{sub 2}MoO{sub 4} and nuclear fuel seems questionable, and Cs release is expected.

  11. Weldability of a RS-PM Al-8Fe-2Mo alloy

    SciTech Connect (OSTI)

    Sampath, K. ); Baeslack, W.A. III )

    1993-08-01

    The weldability of a dispersion-strengthened Al-8Fe-2Mo (wt-%) alloy produced via rapid solidification-powder metallurgy (RS-PM) processing was investigated. Electron beam (EB) and pulsed Nd:YAG laser welding conditions were found to have a significant effect on weld solidification behavior, microstructural development and mechanical properties. Microstructural analysis revealed an influence of local thermal conditions (i.e., temperature gradient and cooling rate), macroscopic solid/liquid interface growth rate and the presence of undissolved/unmelted base metal dispersoid particles on solidification phenomena in the fusion zone. Three different types of solidification microstructures, each of which could be observed to varying degrees within a single weld fusion zone, were observed. Superior weld mechanical properties, including joint efficiencies of 100% in pulsed Nd:YAG laser welds, were achieved when high energy density welding conditions produced increasingly refined microstructures.

  12. Insulator to correlated metal transition in V_1-xMo_xO_2

    SciTech Connect (OSTI)

    Klimczuk, Tomasz; Ronning, Filip; Holman, Katherine; Mcqueen, Tyrel M; Williams, Anthony J; Stephens, P W; Zandbergen, Henny W; Xu, Q; Cava, Robert J

    2009-01-01

    The change from metallic to insulating states is one of the most dramatic transitions that solids undergo on cooling or chemical doping. Many materials display this transition, but only a handful have the right combination of crystal structure and physical properties to serve as model systems. VO{sub 2} is one of those materials. Using Mo as a chemical dopant in VO{sub 2}, we find unanticipated phenomenology for both the electronic and structural characteristics of the resulting insulator to metal transition. The results support a complex, previously proposed scenario involving the coexistence of both electron repulsion and electron pairing for yielding an insulator in VO{sub 2}, but not simply; many issues are raised about local versus itinerant behavior and structure-property correlations in this most iconic ofdoped correlated electron systems.

  13. H-point exciton transitions in bulk MoS{sub 2}

    SciTech Connect (OSTI)

    Saigal, Nihit; Ghosh, Sandip

    2015-05-04

    Reflectance and photoreflectance spectrum of bulk MoS{sub 2} around its direct bandgap energy have been measured at 12?K. Apart from spectral features due to the A and B ground state exciton transitions at the K-point of the Brillouin zone, one observes additional features at nearby energies. Through lineshape analysis the character of two prominent additional features are shown to be quite different from that of A and B. By comparing with reported electronic band structure calculations, these two additional features are identified as ground state exciton transitions at the H-point of the Brillouin zone involving two spin-orbit split valance bands. The excitonic energy gap at the H-point is 1.965?eV with a valance bands splitting of 185?meV. While at the K-point, the corresponding values are 1.920?eV and 205?meV, respectively.

  14. Intense femtosecond photoexcitation of bulk and monolayer MoS{sub 2}

    SciTech Connect (OSTI)

    Paradisanos, I.; Fotakis, C.; Kymakis, E.; Kioseoglou, G.; Stratakis, E.

    2014-07-28

    The effect of femtosecond laser irradiation on bulk and single-layer MoS{sub 2} on silicon oxide is studied. Optical, field emission scanning electron microscopy and Raman microscopy were used to quantify the damage. The intensity of A{sub 1g} and E{sub 2g}{sup 1} vibrational modes was recorded as a function of the number of irradiation pulses. The observed behavior was attributed to laser-induced bond breaking and subsequent atoms removal due to electronic excitations. The single-pulse optical damage threshold was determined for the monolayer and bulk under 800 nm and 1030 nm pulsed laser irradiation, and the role of two-photon versus one photon absorption effects is discussed.

  15. Thermodynamic modeling and experimental validation of the Fe-Al-Ni-Cr-Mo alloy system

    SciTech Connect (OSTI)

    Teng, Zhenke; Zhang, F; Miller, Michael K; Liu, Chain T; Huang, Shenyan; Chou, Y.T.; Tien, R; Chang, Y A; Liaw, Peter K

    2012-01-01

    NiAl-type precipitate-strengthened ferritic steels have been known as potential materials for the steam turbine applications. In this study, thermodynamic descriptions of the B2-NiAl type nano-scaled precipitates and body-centered-cubic (BCC) Fe matrix phase for four alloys based on the Fe-Al-Ni-Cr-Mo system were developed as a function of the alloy composition at the aging temperature. The calculated phase structure, composition, and volume fraction were validated by the experimental investigations using synchrotron X-ray diffraction and atom probe tomography. With the ability to accurately predict the key microstructural features related to the mechanical properties in a given alloy system, the established thermodynamic model in the current study may significantly accelerate the alloy design process of the NiAl-strengthened ferritic steels.

  16. Heat treated 9 Cr-1 Mo steel material for high temperature application

    DOE Patents [OSTI]

    Jablonski, Paul D.; Alman, David; Dogan, Omer; Holcomb, Gordon; Cowen, Christopher

    2012-08-21

    The invention relates to a composition and heat treatment for a high-temperature, titanium alloyed, 9 Cr-1 Mo steel exhibiting improved creep strength and oxidation resistance at service temperatures up to 650.degree. C. The novel combination of composition and heat treatment produces a heat treated material containing both large primary titanium carbides and small secondary titanium carbides. The primary titanium carbides contribute to creep strength while the secondary titanium carbides act to maintain a higher level of chromium in the finished steel for increased oxidation resistance, and strengthen the steel by impeding the movement of dislocations through the crystal structure. The heat treated material provides improved performance at comparable cost to commonly used high-temperature steels such as ASTM P91 and ASTM P92, and requires heat treatment consisting solely of austenization, rapid cooling, tempering, and final cooling, avoiding the need for any hot-working in the austenite temperature range.

  17. UPDATE ON FRICTION BONDING OF MONOLITHIC U-MO FUEL PLATES

    SciTech Connect (OSTI)

    D. E. Burkes; N. P. Hallinan; J. M. Wight; M. D. Chapple

    2007-09-01

    Friction Bonding (FB), formerly referred to as Friction Stir Welding, is an alternative plate fabrication technique to encapsulate monolithic U-Mo fuel foils inside 6061-T6 aluminum alloy cladding. Over the past year, significant progress has been made in the area of FB, including improvements in tool material, tool design, process parameters, cooling capability and capacity and modeling, all of which improve and enhance the quality of fabricated fuel plates, reproducibility of the fabrication process and bond quality of the fuel plates. Details of this progress and how it relates to the observed improvements and enhancements are discussed. In addition, details on how these improvements have been implemented into the last two RERTR mini-plate irradiation campaigns are also discussed.

  18. High reflectance-low stress Mo-Si multilayer reflective coatings

    DOE Patents [OSTI]

    Montcalm, Claude; Mirkarimi, Paul B.

    2000-01-01

    A high reflectance-low stress Mo-Si multilayer reflective coating particularly useful for the extreme ultraviolet (EUV) wavelength region. While the multilayer reflective coating has particular application for EUV lithography, it has numerous other applications where high reflectance and low stress multilayer coatings are utilized. Multilayer coatings having high near-normal incidence reflectance (R.gtoreq.65%) and low residual stress (.ltoreq.100 MPa) have been produced using thermal and non-thermal approaches. The thermal approach involves heating the multilayer coating to a given temperature for a given time after deposition in order to induce structural changes in the multilayer coating that will have an overall "relaxation" effect without reducing the reflectance significantly.

  19. Process for fabricating high reflectance-low stress Mo--Si multilayer reflective coatings

    DOE Patents [OSTI]

    Montcalm, Claude; Mirkarimi, Paul B.

    2001-01-01

    A high reflectance-low stress Mo--Si multilayer reflective coating particularly useful for the extreme ultraviolet (EUV) wavelength region. While the multilayer reflective coating has particular application for EUV lithography, it has numerous other applications where high reflectance and low stress multilayer coatings are utilized. Multilayer coatings having high near-normal incidence reflectance (R.gtoreq.65%) and low residual stress (.ltoreq.100 MPa) have been produced using thermal and non-thermal approaches. The thermal approach involves heating the multilayer coating to a given temperature for a given time after deposition in order to induce structural changes in the multilayer coating that will have an overall "relaxation" effect without reducing the reflectance significantly.

  20. Microstructural Characterization of Irradiated U-7Mo/Al-5Si Dispersion to High Fission Density

    SciTech Connect (OSTI)

    J. Gan; B. D. Miller; D. D. Keiser, Jr.; A. B. Robinson; J. W. Madden; P. G. Medvedev; D. M. Wachs

    2014-11-01

    The fuel development program for research and test reactors calls for improved knowledge on the effect of microstructure on fuel performance in reactors. This work summarizes the recent TEM microstructural characterization of an irradiated U-7Mo/Al-5Si dispersion fuel plate (R3R050) irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory to 5.21021 fissions/cm3. While a large fraction of the fuel grains is decorated with large bubbles, there is no evidence showing interlinking of these large bubbles at the specified fission density. The attachment of solid fission product precipitates to the bubbles is likely the result of fission product diffusion into these bubbles. The process of fission gas bubble superlattice collapse appears through bubble coalescence. The results are compared with the previous TEM work of the dispersion fuels irradiated to lower fission density from the same fuel plate.

  1. Prediction of U-Mo dispersion nuclear fuels with Al-Si alloy using artificial neural network

    SciTech Connect (OSTI)

    Susmikanti, Mike; Sulistyo, Jos

    2014-09-30

    Dispersion nuclear fuels, consisting of U-Mo particles dispersed in an Al-Si matrix, are being developed as fuel for research reactors. The equilibrium relationship for a mixture component can be expressed in the phase diagram. It is important to analyze whether a mixture component is in equilibrium phase or another phase. The purpose of this research it is needed to built the model of the phase diagram, so the mixture component is in the stable or melting condition. Artificial neural network (ANN) is a modeling tool for processes involving multivariable non-linear relationships. The objective of the present work is to develop code based on artificial neural network models of system equilibrium relationship of U-Mo in Al-Si matrix. This model can be used for prediction of type of resulting mixture, and whether the point is on the equilibrium phase or in another phase region. The equilibrium model data for prediction and modeling generated from experimentally data. The artificial neural network with resilient backpropagation method was chosen to predict the dispersion of nuclear fuels U-Mo in Al-Si matrix. This developed code was built with some function in MATLAB. For simulations using ANN, the Levenberg-Marquardt method was also used for optimization. The artificial neural network is able to predict the equilibrium phase or in the phase region. The develop code based on artificial neural network models was built, for analyze equilibrium relationship of U-Mo in Al-Si matrix.

  2. Mesoporous carbon-containing MoS{sub 2} materials formed from the in situ decomposition of tetraalkylammonium thiomolybdates

    SciTech Connect (OSTI)

    Alonso, Gabriel; Berhault, Gilles; Paraguay, Francisco; Rivera, Eric; Fuentes, Sergio; Chianelli, Russell R

    2003-05-26

    Molybdenum disulfide with unique mesoporous structure was synthesized from tetraalkylammonium thiometallate precursors in situ decomposed in a batch reactor in the presence of dibenzothiophene (DBT). The precursors used in this study were tetraalkylammonium thiomolybdates with alkyl groups ranging from propyl to octyl. Molybdenum disulfide thus prepared presents high surface area (from 255 up to 329 m{sup 2}/g), high content of carbon (C/Mo=2.7-4.0) and type IV nitrogen adsorption-desorption isotherms when decomposed from tetrahexyl-, tetraheptyl- or tetraoctylammonium thiomolybdates. The as-formed materials are poorly crystallized with a very weak intensity of the (0 0 2) peak of the 2H-MoS{sub 2} structure. Such diffraction patterns are characteristic of exfoliated samples. Characterization by TEM shows a disordered layered structure with no long range order for the MoS{sub 2} catalysts. Therefore, the nature of the alkyl group in the precursor affects both the surface area and the pore size distribution of the final MoS{sub 2} catalysts with a progressive morphological modification up to a mesoporous organization.

  3. A New Molybdenum Nitride Catalyst with Rhombohedral MoS2 Structure for Hydrogenation Applications

    SciTech Connect (OSTI)

    Wang, Shanmin; Ge, Hui; Sun, Shouli; Zhang, Jianzhong; Liu, Fangming; Wen, Xiaodong; Yu, Xiaohui; Wang, Liping; Zhang, Yi; Xu, Hongwu; Neuefeind, Joerg C.; Qin, Zhangfeng; Chen, Changfeng; Jin, Changqin; Li, Yongwang; He, Duanwei; Zhao, Yusheng

    2015-03-23

    Nitrogen-rich transition-metal nitrides hold great promise to be the next-generation catalysts for clean and renewable energy applications. However, incorporation of nitrogen into the crystalline lattices of transition metals is thermodynamically unfavorable at atmospheric pressure; most of the known transition metal nitrides are nitrogen-deficient with molar ratios of N:metal less than a unity. In this work, we have formulated a high-pressure route for the synthesis of a nitrogen-rich molybdenum nitride through a solid-state ion-exchange reaction. The newly discovered nitride, 3R-MoN2, adopts a rhombohedral R3m structure, isotypic with MoS2. This new nitride exhibits catalytic activities that are three times more active than the traditional catalyst MoS2 for the hydrodesulfurization of dibenzothiophene and more than twice as high in the selectivity to hydrogenation. The nitride is also catalytically active in sour methanation of syngas with >80% CO and H2 conversion at 723 K. Lastly, our formulated route for the synthesis of 3R-MoN2 is at a moderate pressure of 3.5 GPa and, thus, is feasible for industrial-scale catalyst production.

  4. Ferromagnetic superexchange in insulating Cr2MoO6 by controlling orbital hybridization

    SciTech Connect (OSTI)

    Zhu, M.; Do, D.; Dela Cruz, Clarina R.; Dun, Zhiling; Cheng, J. -G.; Goto, H.; Uwatoko, Yoshiya; Zou, T.; Zhou, Haidon D.; Mahanti, Subhendra D.; Ke, Xianglin

    2015-09-11

    We report the magnetic and electronic structures of the newly synthesized inverse-trirutile compound Cr2MoO6. Despite the same crystal symmetry and similar bond-lengths and bond-angles to Cr2TeO6, Cr2MoO6 possesses a magnetic structure of the Cr2MoO6 type, different from that seen in Cr2TeO6. Ab-initio electronic structure calculations show that the sign and strength of the Cr-O-Cr exchange coupling is strongly influenced by the hybridization between Mo 4d and O 2p orbitals. This result further substantiates our recently proposed mechanism for tuning the exchange interaction between two magnetic atoms by modifying the electronic states of the non-magnetic atoms in the exchange path through orbital hybridization. This approach is fundamentally different from the conventional methods of controlling the exchange interaction by either carrier injection or through structural distortions.

  5. Crystal structure, electronic structure, and photoluminescent properties of SrMoO{sub 4}:Tb{sup 3+} phosphors

    SciTech Connect (OSTI)

    Park, Sung Wook; Moon, Byung Kee; Jeong, Jung Hyun; Bae, Jong Seong; Kim, Jung Hwan

    2015-10-15

    Highlights: • SrMoO{sub 4}:Tb{sup 3+} phosphor samples were synthesized at different temperatures. • The crystal and electronic structures, and luminescence properties were studied. • The excitation peak shifts to red with increasing the sintering temperature. • The luminescence mechanism of SrMoO{sub 4}:Tb{sup 3+} was suggested. - Abstract: The experimental and theoretical studies of the optical properties of SrMoO{sub 4}:Tb{sup 3+} phosphors were carried out. The structural, optical, and electronical properties of the phosphors were systematically studied. The phosphor samples were crystallized at different temperatures via a sol–gel method. Excitation spectra of SrMoO{sub 4}:Tb{sup 3+} powder samples exhibited gradual red shift and luminescent intensity changed with increasing the sintering temperature. Such spectral changes depend strongly on the crystallographic properties such as lattice parameters and crystallinity. The shift of the excitation spectra is mainly ascribed to the covalent bond interaction between Mo−O bonds. An energy band model was demonstrated to describe the luminescence mechanism in the material.

  6. Concept Feasibility Report for Using Co-Extrusion to Bond Metals to Complex Shapes of U-10Mo

    SciTech Connect (OSTI)

    Lavender, Curt A.; Paxton, Dean M.; Smith, Mark T.; Soulami, Ayoub; Joshi, Vineet V.; Burkes, Douglas

    2013-12-30

    In support of the Convert Program of the U.S. Department of Energys National Nuclear Security Administration (DOE/NNSA) Global Threat Reduction Initiative (GTRI), Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum (U-10Mo) alloy plate fuel for the U.S. high-performance research reactors (USHPRR). This report documents the results of PNNLs efforts to develop the extrusion process for this concept. The approach to the development of a co-extruded complex-shaped fuel has been described and an extrusion of DU-10Mo was made. The initial findings suggest that given the extrusion forces required for processing U-10Mo, the co-extrusion process can meet the production demands of the USHPRR fuel and may be a viable production method. The development activity is in the early stages and has just begun to identify technical challenges to address details such as dimensional tolerances and shape control. New extrusion dies and roll groove profiles have been developed and will be assessed by extrusion and rolling of U-10Mo during the next fiscal year. Progress on the development and demonstration of the co-extrusion process for flat and shaped fuel is reported in this document

  7. The photocatalysis of Bi{sub 2}MoO{sub 6} under the irradiation of blue LED

    SciTech Connect (OSTI)

    Sun, Yuanyuan; Wang, Wenzhong Zhang, Ling; Sun, Songmei

    2013-10-15

    Graphical abstract: - Highlights: • ·OH trap and hole sink were involved to investigate the active radicals. • Holes play a more important role in the degradation of RhB. • The ·OH were related to the decomposition of phenol. • The ·O{sub 2}-played a leading role in the photodegradation of phenol. • Blue LED is competitive and promising alternative for the future application. - Abstract: Bi{sub 2}MoO{sub 6} has been reported as a promising photocatalyst in wastewater treatment. The active radicals generated over the Bi{sub 2}MoO{sub 6} during the photocatalytic process were thought to be hydroxyl radical (·OH) but have not been proved. Herein, Bi{sub 2}MoO{sub 6} with nanoplate like morphology was synthesized and its photocatalytic performances in the degradation of rhodamine B (RhB) and phenol as colored and colorless model pollutants respectively were evaluated under the irradiation of blue light emitting diode (LED). The tert-butyl alcohol (TBA) as a ·OH trap and ethylene diamine tetraacetic acid (EDTA) as a hole sink were involved to investigate the main active groups that are generated on Bi{sub 2}MoO{sub 6} and function during the photodegradation of RhB and phenol. In addition, it is a competitive and promising alternative plan to use blue LED as light source for the future practical application in environmental remediation.

  8. Thermomechanical process optimization of U-10wt% Mo Part 2: The effect of homogenization on the mechanical properties and microstructure

    SciTech Connect (OSTI)

    Joshi, Vineet V.; Nyberg, Eric A.; Lavender, Curt A.; Paxton, Dean M.; Burkes, Douglas E.

    2015-07-09

    Low-enriched uranium alloyed with 10 wt% molybdenum (U-10Mo) is currently being investigated as an alternative fuel for the highly enriched uranium used in several of the United States high performance research reactors. Development of the methods to fabricate the U-10Mo fuel plates is currently underway and requires fundamental understanding of the mechanical properties at the expected processing temperatures. In the first part of this series, it was determined that the as-cast U-10Mo had a dendritic microstructure with chemical inhomogeneity and underwent eutectoid transformation during hot compression testing. In the present (second) part of the work, the as-cast samples were heat treated at several temperatures and times to homogenize the Mo content. Like the previous as-cast material, the homogenized materials were then tested under compression between 500 and 800C. The as-cast samples and those treated at 800C for 24 hours had grain sizes of 25-30 ?m, whereas those treated at 1000C for 16 hours had grain sizes around 250 ?m before testing. Upon compression testing, it was determined that the heat treatment had effects on the mechanical properties and the precipitation of the lamellar phase at sub-eutectoid temperatures.

  9. Irradiation Performance of U-Mo Alloy Based ‘Monolithic’ Plate-Type Fuel – Design Selection

    SciTech Connect (OSTI)

    A. B. Robinson; G. S. Chang; D. D. Keiser, Jr.; D. M. Wachs; D. L. Porter

    2009-08-01

    A down-selection process has been applied to the U-Mo fuel alloy based monolithic plate fuel design, supported by irradiation testing of small fuel plates containing various design parameters. The irradiation testing provided data on fuel performance issues such as swelling, fuel-cladding interaction (interdiffusion), blister formation at elevated temperatures, and fuel/cladding bond quality and effectiveness. U-10Mo (wt%) was selected as the fuel alloy of choice, accepting a somewhat lower uranium density for the benefits of phase stability. U-7Mo could be used, with a barrier, where the trade-off for uranium density is critical to nuclear performance. A zirconium foil barrier between fuel and cladding was chosen to provide a predictable, well-bonded, fuel-cladding interface, allowing little or no fuel-cladding interaction. The fuel plate testing conducted to inform this selection was based on the use of U-10Mo foils fabricated by hot co-rolling with a Zr foil. The foils were subsequently bonded to Al-6061 cladding by hot isostatic pressing or friction stir bonding.

  10. Development and validation of capabilities to measure thermal properties of layered monolithic U-Mo alloy plate-type fuel

    SciTech Connect (OSTI)

    Burkes, Douglas; Casella, Andrew M.; Buck, Edgar C.; Casella, Amanda J.; Edwards, Matthew K.; MacFarlan, Paul J.; Pool, Karl N.; Smith, Frances N.; Steen, Franciska H.

    2014-07-19

    The uranium-molybdenum (U-Mo) alloy in a monolithic form has been proposed as one fuel design capable of converting some of the world’s highest power research reactors from the use of high enriched uranium (HEU) to low enriched uranium (LEU). One aspect of the fuel development and qualification process is to demonstrate appropriate understanding of thermal conductivity behavior of the fuel system as a function of temperature and expected irradiation conditions. The purpose of this paper is to verify and validate the functionality of equipment methods installed in hot cells for eventual measurements on irradiated uranium-molybdenum (U-Mo) monolithic fuel specimens, procedures to operate the equipment, and models to extract the desired thermal properties. The results presented here demonstrate the adequacy of the equipment, procedures and models that have been developed for this purpose based on measurements conducted on surrogate depleted uranium-molybdenum (DU-Mo) alloy samples containing a zirconium diffusion barrier and clad in aluminum alloy 6061 (AA6061). The results are in excellent agreement with thermal property data reported in the literature for similar U-Mo alloys as a function of temperature.

  11. Modification of polymer velvet cathode via metallic Mo coating for enhancement of high-current electron emission performances

    SciTech Connect (OSTI)

    Xiong, Ying; Wang, Bing; Yi, Yong; Xia, Liansheng; Zhang, Huang

    2013-09-15

    The effect of surface Mo coating on the high-current electron emission performances for polymer velvet cathode has been investigated in a diode with A-K gap of 11.5 cm by the combination of time-resolved electrical diagnostic and temporal pressure variation. Compared with uncoated polymer velvet cathode under the single-pulsed emission mode, the Mo-coated one shows lower outgassing levels (?0.40 Pa L), slower cathode plasma expansion velocity (?2.30 cm/?s), and higher emission stability as evidences by the change in cathode current, temporal pressure variation, and diode perveance. Moreover, after Mo coating, the emission consistency of the polymer velvet cathode between two adjacent pulses is significantly improved in double-pulsed emission mode with ?500 ns interval between two pulses, which further confirms the effectiveness of Mo coating for enhancement of electron emission performance of polymer velvet cathodes. These results should be of interest to the high-repetitive high-power microwave systems with cold cathodes.

  12. Four-point Bend Testing of Irradiated Monolithic U-10Mo Fuel

    SciTech Connect (OSTI)

    Rabin, B. H.; Lloyd, W. R.; Schulthess, J. L.; Wright, J. K.; Lind, R. P.; Scott, L.; Wachs, K. M.

    2015-03-01

    This paper presents results of recently completed studies aimed at characterizing the mechanical properties of irradiated U-10Mo fuel in support of monolithic base fuel qualification. Mechanical properties were evaluated in four-point bending. Specimens were taken from fuel plates irradiated in the RERTR-12 and AFIP-6 Mk. II irradiation campaigns, and tests were conducted in the Hot Fuel Examination Facility (HFEF) at Idaho National Laboratory (INL). The monolithic fuel plates consist of a U-10Mo fuel meat covered with a Zr diffusion barrier layer fabricated by co-rolling, clad in 6061 Al using a hot isostatic press (HIP) bonding process. Specimens exhibited nominal (fresh) fuel meat thickness ranging from 0.25 mm to 0.64 mm, and fuel plate average burnup ranged from approximately 0.4 x 1021 fissions/cm3 to 6.0 x 1021 fissions/cm3. After sectioning the fuel plates, the 6061 Al cladding was removed by dissolution in concentrated NaOH. Pre- and post-dissolution dimensional inspections were conducted on test specimens to facilitate accurate analysis of bend test results. Four-point bend testing was conducted on the HFEF Remote Load Frame at a crosshead speed of 0.1 mm/min using custom-designed test fixtures and calibrated load cells. All specimens exhibited substantially linear elastic behavior and failed in a brittle manner. The influence of burnup on the observed slope of the stress-strain curve and the calculated fracture strength is discussed.

  13. Low-Frequency Interlayer Raman Modes to Probe Interface of Twisted Bilayer MoS 2

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

    Huang, Shengxi; Liang, Liangbo; Ling, Xi; Puretzky, Alexander A.; Geohegan, David B.; Sumpter, Bobby G.; Kong, Jing; Meunier, Vincent; Dresselhaus, Mildred S.

    2016-02-21

    A variety of van der Waals homo- and hetero- structures assembled by stamping monolayers together present optoelectronic properties suitable for diverse applications. Understanding the details of the interlayer stacking and resulting coupling is crucial for tuning these properties. Twisted bilayer transition metal dichalcogenides offer a great platform for developing a precise understanding of the structure/property relationship. Here, we study the low-frequency interlayer shear and breathing Raman modes (<50 cm-1) in twisted bilayer MoS2 by Raman spectroscopy and first-principles modeling. Twisting introduces both rotational and translational shifts and significantly alters the interlayer stacking and coupling, leading to notable frequency and intensitymore » changes of low-frequency modes. The frequency variation can be up to 8 cm-1 and the intensity can vary by a factor of ~5 for twisting near 0 and 60 , where the stacking is a mixture of multiple high-symmetry stacking patterns and is thus especially sensitive to twisting. Moreover, for twisting angles between 20 and 40 , the interlayer coupling is nearly constant since the stacking results in mismatched lattices over the entire sample. It follows that the Raman signature is relatively uniform. Interestingly, unlike the breathing mode, the shear mode is extremely sensitive to twisting: it disappears between 20 and 40 as its frequency drops to almost zero due to the stacking-induced mismatch. Note that for some samples, multiple breathing mode peaks appear, indicating non-uniform coupling across the interface. In contrast to the low-frequency interlayer modes, high-frequency intralayer Raman modes are much less sensitive to interlayer stacking and coupling, showing negligible changes upon twisting. Our research demonstrates the effectiveness of low-frequency Raman modes for probing the interfacial coupling and environment of twisted bilayer MoS2, and potentially other two-dimensional materials and

  14. Development of an energy-use estimation methodology for the revised Navy Manual MO-303

    SciTech Connect (OSTI)

    Richman, E.E.; Keller, J.M.; Wood, A.G.; Dittmer, A.L.

    1995-01-01

    The U.S. Navy commissioned Pacific Northwest Laboratory (PNL) to revise and/or update the Navy Utilities Targets Manual, NAVFAC MO-303 (U.S. Navy 1972b). The purpose of the project was to produce a current, applicable, and easy-to-use version of the manual for use by energy and facility engineers and staff at all Navy Public Works Centers (PWCs), Public Works Departments (PWDs), Engineering Field Divisions (EFDs), and other related organizations. The revision of the MO-303 manual involved developing a methodology for estimating energy consumption in buildings and ships. This methodology can account for, and equitably allocate, energy consumption within Navy installations. The analyses used to develop this methodology included developing end-use intensities (EUIs) from a vast collection of Navy base metering and billing data. A statistical analysis of the metering data, weather data, and building energy-use characteristics was used to develop appropriate EUI values for use at all Navy bases. A complete Navy base energy reconciliation process was also created for use in allocating all known energy consumption. Initial attempts to use total Navy base consumption values did not produce usable results. A parallel effort using individual building consumption data provided an estimating method that incorporated weather effects. This method produced a set of building EUI values and weather adjustments for use in estimating building energy use. A method of reconciling total site energy consumption was developed based on a {open_quotes}zero-sum{close_quotes} principle. This method provides a way to account for all energy use and apportion part or all of it to buildings and other energy uses when actual consumption is not known. The entire text of the manual was also revised to present a more easily read understood and usable document.

  15. NUMERICAL SIMULATION FOR MECHANICAL BEHAVIOR OF U10MO MONOLITHIC MINIPLATES FOR RESEARCH AND TEST REACTORS

    SciTech Connect (OSTI)

    Hakan Ozaltun & Herman Shen

    2011-11-01

    This article presents assessment of the mechanical behavior of U-10wt% Mo (U10Mo) alloy based monolithic fuel plates subject to irradiation. Monolithic, plate-type fuel is a new fuel form being developed for research and test reactors to achieve higher uranium densities within the reactor core to allow the use of low-enriched uranium fuel in high-performance reactors. Identification of the stress/strain characteristics is important for understanding the in-reactor performance of these plate-type fuels. For this work, three distinct cases were considered: (1) fabrication induced residual stresses (2) thermal cycling of fabricated plates; and finally (3) transient mechanical behavior under actual operating conditions. Because the temperatures approach the melting temperature of the cladding during the fabrication and thermal cycling, high temperature material properties were incorporated to improve the accuracy. Once residual stress fields due to fabrication process were identified, solution was used as initial state for the subsequent simulations. For thermal cycling simulation, elasto-plastic material model with thermal creep was constructed and residual stresses caused by the fabrication process were included. For in-service simulation, coupled fluid-thermal-structural interaction was considered. First, temperature field on the plates was calculated and this field was used to compute the thermal stresses. For time dependent mechanical behavior, thermal creep of cladding, volumetric swelling and fission induced creep of the fuel foil were considered. The analysis showed that the stresses evolve very rapidly in the reactor. While swelling of the foil increases the stress of the foil, irradiation induced creep causes stress relaxation.

  16. Microstructural characterization of as-cast biocompatible Co-Cr-Mo alloys

    SciTech Connect (OSTI)

    Giacchi, J.V.; Morando, C.N.; Fornaro, O.; Palacio, H.A.

    2011-01-15

    The microstructure of a cobalt-base alloy (Co-Cr-Mo) obtained by the investment casting process was studied. This alloy complies with the ASTM F75 standard and is widely used in the manufacturing of orthopedic implants because of its high strength, good corrosion resistance and excellent biocompatibility properties. This work focuses on the resulting microstructures arising from samples poured under industrial environment conditions, of three different Co-Cr-Mo alloys. For this purpose, we used: 1) an alloy built up from commercial purity constituents, 2) a remelted alloy and 3) a certified alloy for comparison. The characterization of the samples was achieved by using optical microscopy (OM) with a colorant etchant to identify the present phases and scanning electron microscopy (SE-SEM) and energy dispersion spectrometry (EDS) techniques for a better identification. In general the as-cast microstructure is a Co-fcc dendritic matrix with the presence of a secondary phase, such as the M{sub 23}C{sub 6} carbides precipitated at grain boundaries and interdendritic zones. These precipitates are the main strengthening mechanism in this type of alloys. Other minority phases were also reported and their presence could be linked to the cooling rate and the manufacturing process variables and environment. - Research Highlights: {yields}The solidification microstructure of an ASTM-F75 type alloy were studied. {yields}The alloys were poured under an industrial environment. {yields}Carbides and sigma phase identified by color metallography and scanning microscopy (SEM and EDS). {yields}Two carbide morphologies were detected 'blocky type' and 'pearlite type'. {yields}Minority phases were also detected.

  17. Characterization of intergranular fission gas bubbles in U-Mo fuel.

    SciTech Connect (OSTI)

    Kim, Y. S.; Hofman, G.; Rest, J.; Shevlyakov, G. V.; Nuclear Engineering Division; SSCR RIAR

    2008-04-14

    This report can be divided into two parts: the first part, which is composed of sections 1, 2, and 3, is devoted to report the analyses of fission gas bubbles; the second part, which is in section 4, is allocated to describe the mechanistic model development. Swelling data of irradiated U-Mo alloy typically show that the kinetics of fission gas bubbles is composed of two different rates: lower initially and higher later. The transition corresponds to a burnup of {approx}0 at% U-235 (LEU) or a fission density of {approx}3 x 10{sup 21} fissions/cm{sup 3}. Scanning electron microscopy (SEM) shows that gas bubbles appear only on the grain boundaries in the pretransition regime. At intermediate burnup where the transition begins, gas bubbles are observed to spread into the intragranular regions. At high burnup, they are uniformly distributed throughout fuel. In highly irradiated U-Mo alloy fuel large-scale gas bubbles form on some fuel particle peripheries. In some cases, these bubbles appear to be interconnected and occupy the interface region between fuel and the aluminum matrix for dispersion fuel, and fuel and cladding for monolithic fuel, respectively. This is a potential performance limit for U-Mo alloy fuel. Microscopic characterization of the evolution of fission gas bubbles is necessary to understand the underlying phenomena of the macroscopic behavior of fission gas swelling that can lead to a counter measure to potential performance limit. The microscopic characterization data, particularly in the pre-transition regime, can also be used in developing a mechanistic model that predicts fission gas bubble behavior as a function of burnup and helps identify critical physical properties for the future tests. Analyses of grain and grain boundary morphology were performed. Optical micrographs and scanning electron micrographs of irradiated fuel from RERTR-1, 2, 3 and 5 tests were used. Micrographic comparisons between as-fabricated and as-irradiated fuel revealed

  18. Partial substitution of Mo{sup 6+} by S{sup 6+} in the fast oxide ion conductor La{sub 2}Mo{sub 2}O{sub 9}: Synthesis, structure and sulfur depletion

    SciTech Connect (OSTI)

    Mhadhbi, Noureddine; Corbel, Gwenaeel; Lacorre, Philippe; Bulou, Alain

    2012-06-15

    Powder-solid state reaction route using La{sub 2}(SO{sub 4}){sub 3} as sulfur source was used to prepare compositions of the solid solution La{sub 2}Mo{sub 2-y}S{sub y}O{sub 9}. Single phases were only obtained in the substitution range extending up to y=0.8 (40 mol% S) at the annealing temperature of 850 Degree-Sign C with regard to the limit of stability of the lanthanum sulphate reactant. Within the synthesis conditions, a stabilization of the high temperature {beta}-form is observed from and above y=0.1 (5 mol% S). Temperature-controlled X-ray diffraction and thermogravimetric analyses have shown that La{sub 2}Mo{sub 2-y}S{sub y}O{sub 9} raw powders undergo thermal decompositions in two steps. Heating above 900 Degree-Sign C, a sulfur depletion to the benefit of molybdenum in La{sub 2}Mo{sub 2-y}S{sub y}O{sub 9} raw powders leads to the formation of La{sub 2}SO{sub 6}. At higher temperature, the exsolved La{sub 2}SO{sub 6} phase then decomposes into La{sub 2}O{sub 3}, which in turn reacts with the sulfur-depleted La{sub 2}Mo{sub 2}O{sub 9} phase to form La{sub 2}MoO{sub 6}. The present study also reveals that depending on the substitution rate y, the sulfur depletion can be induced by ball-milling of raw powders. Along the La{sub 2}Mo{sub 2-y}S{sub y}O{sub 9} series, the isovalent substitution of molybdenum by sulfur tends to restrict in magnitude, or even to suppress above 400 Degree-Sign C, the distortive thermal expansion of the cubic {beta}-type structure, thus strongly decreasing the conductance at high temperature. - Graphical abstract: La{sub 2}O{sub 3}-MoO{sub 3}-'SO{sub 3}' ternary phase diagram showing the exsolution path at low temperature (white arrows) and the total decomposition path at high temperature (black arrows) of {beta}-La{sub 2}Mo{sub 2-y}S{sub y}O{sub 9} raw powders. Highlights: Black-Right-Pointing-Pointer Isovalent substitution of molybdenum by sulfur in La{sub 2}Mo{sub 2}O{sub 9} up to 40 mol%. Black

  19. Superconductivity of magnesium diboride

    SciTech Connect (OSTI)

    Bud’ko, Sergey L.; Canfield, Paul C.

    2015-07-15

    Over the past 14 years MgB2 has gone from a startling discovery to a promising, applied superconductor. In our article we present a brief overview of the synthesis and the basic superconducting properties of this remarkable compound. Specifically, the effect of pressure, substitutions and neutron irradiation on superconducting properties are discussed.

  20. Superconductivity of magnesium diboride

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

    Bud’ko, Sergey L.; Canfield, Paul C.

    2015-07-15

    Over the past 14 years MgB2 has gone from a startling discovery to a promising, applied superconductor. In our article we present a brief overview of the synthesis and the basic superconducting properties of this remarkable compound. Specifically, the effect of pressure, substitutions and neutron irradiation on superconducting properties are discussed.

  1. Magnesium Powertrain Cast Components

    Broader source: Energy.gov [DOE]

    2009 DOE Hydrogen Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C.

  2. Method for generating a crystalline {sup 99}MoO{sub 3} product and the isolation {sup 99m}Tc compositions therefrom

    DOE Patents [OSTI]

    Bennett, R.G.; Christian, J.D.; Kirkham, R.J.; Tranter, T.J.

    1998-09-01

    An improved method is described for producing {sup 99m}Tc compositions. {sup 100}Mo metal is irradiated with photons in a particle (electron) accelerator to produce {sup 99}Mo metal which is dissolved in a solvent. A solvated {sup 99}Mo product is then dried to generate a supply of {sup 99}MoO{sub 3} crystals. The crystals are thereafter heated at a temperature which will sublimate the crystals and form a gaseous mixture containing vaporized {sup 99m}TcO{sub 3} and vaporized {sup 99m}TcO{sub 2} but will not cause the production of vaporized {sup 99}MoO{sub 3}. The mixture is then combined with an oxidizing gas to generate a gaseous stream containing vaporized {sup 99m}Tc{sub 2}O{sub 7}. Next, the gaseous stream is cooled to a temperature sufficient to convert the vaporized {sup 99m}Tc{sub 2}O{sub 7} into a condensed {sup 99m}Tc-containing product. The product has high purity levels resulting from the use of reduced temperature conditions and ultrafine crystalline {sup 99}MoO{sub 3} starting materials with segregated {sup 99m}Tc compositions therein which avoid the production of vaporized {sup 99}MoO{sub 3} contaminants. 1 fig.

  3. Method for generating a crystalline .sup.99 MoO.sub.3 product and the isolation .sup.99m Tc compositions therefrom

    DOE Patents [OSTI]

    Bennett, Ralph G.; Christian, Jerry D.; Kirkham, Robert J.; Tranter, Troy J.

    1998-01-01

    An improved method for producing .sup.99m Tc compositions. .sup.100 Mo metal is irradiated with photons in a particle (electron) accelerator to produce .sup.99 Mo metal which is dissolved in a solvent. A solvated .sup.99 Mo product is then dried to generate a supply of .sup.99 MoO.sub.3 crystals. The crystals are thereafter heated at a temperature which will sublimate the crystals and form a gaseous mixture containing vaporized .sup.99m TcO.sub.3 and vaporized .sup.99m TcO.sub.2 but will not cause the production of vaporized .sup.99 MoO.sub.3. The mixture is then combined with an oxidizing gas to generate a gaseous stream containing vaporized .sup.99m Tc.sub.2 O.sub.7. Next, the gaseous stream is cooled to a temperature sufficient to convert the vaporized .sup.99m Tc.sub.2 O.sub.7 into a condensed .sup.99m Tc-containing product. The product has high purity levels resulting from the use of reduced temperature conditions and ultrafine crystalline .sup.99 MoO.sub.3 starting materials with segregated .sup.99m Tc compositions therein which avoid the production of vaporized .sup.99 MoO.sub.3 contaminants.

  4. Study of structure of the TiO{sub 2}–MoO{sub 3} bilayer films by Raman spectroscopy

    SciTech Connect (OSTI)

    Santos, Elias de Barros; Sigoli, Fernando Aparecido; Mazali, Italo Odone

    2014-12-15

    Highlights: • TiO{sub 2}–MoO{sub 3} bilayer thin films were easily prepared by dip-coating technique. • Ti and Mo metallo-organic compounds were used as source of its respective oxide. • TiO{sub 2} in anatase phase and orthorhombic phase of α-MoO{sub 3} were identified. • The bilayer structure was investigated by Raman spectroscopy. - Abstract: In this work, TiO{sub 2}–MoO{sub 3} films were easily prepared by dip-coating technique and metallo-organic decomposition process (MOD). Raman analyses indicate the formation of TiO{sub 2} in anatase phase and orthorhombic phase of α-MoO{sub 3}. It was observed that the Raman bands intensities attributed to TiO{sub 2} and MoO{sub 3} oxides were dependent on the number of decomposition–deposition cycles (DDC). The different number of DDC generates films with different thicknesses and the Raman signal was sensitive to this variation. Raman analyses provided qualitative information about the bilayer structure of the bi-component TiO{sub 2}–MoO{sub 3} films, which was confirmed by scanning electron microscopy. In this direction, the dip-coating technique and MOD process can be an efficient strategy to facile preparation of many samples to be used in applications.

  5. Synthesis and mechanical properties of CrMoC{sub x}N{sub 1-x} coatings deposited by a hybrid coating system

    SciTech Connect (OSTI)

    Yun, Ji Hwan; Heo, Su Jeong; Kim, Kwang Ryul; Kim, Kwang Ho

    2008-01-15

    Quaternary CrMoC{sub x}N{sub 1-x} coatings were deposited on steel substrates (AISI D2) and Si wafers by a hybrid coating system combining an arc-ion plating technique and a dc reactive magnetron sputtering technique using Cr and Mo targets in an Ar/N{sub 2}/CH{sub 4} gaseous mixture. The carbon content of CrMoC{sub x}N{sub 1-x} coatings was linearly increased with increasing CH{sub 4}/(CH{sub 4}+N{sub 2}) gas flow rate ratio. The maximum hardness of 44 GPa was obtained from the CrMoC{sub x}N{sub 1-x} coatings containing a carbon content of x=0.33 with a residual stress of -4.4 GPa. The average friction coefficient of Cr-Mo-N coatings was 0.42, and it is decreased to 0.31 after applying CrMoC{sub x}N{sub 1-x} coatings. This result was caused by the formation of a carbon-rich transfer layer that acted as a solid lubricant to reduce contact between the coating surface and steel ball. The microstructure of the coatings was investigated by x-ray diffraction, scanning electron microscopy, and x-ray photoelectron spectroscopy. In this work, the microstructure and mechanical properties of the CrMoC{sub x}N{sub 1-x} coatings were systematically investigated with the instrumental analyses.

  6. Facile deposition of Ag{sub 3}PO{sub 4} on graphene-like MoS{sub 2} nanosheets for highly efficient photocatalysis

    SciTech Connect (OSTI)

    Wang, Peifu; Shi, Penghui; Hong, Yuanchen; Zhou, Xuejun; Yao, Weifeng

    2015-02-15

    Graphical abstract: The photocatalytic performance of Ag{sub 3}PO{sub 4} was highly improved by the in situ deposition of Ag{sub 3}PO{sub 4} particles on graphene-like MoS{sub 2} nanosheets. - Highlights: A novel composite photocatalyst was synthesized by depositing Ag{sub 3}PO{sub 4} on the graphene-like MoS{sub 2} nanosheets. Ag{sub 3}PO{sub 4}/MoS{sub 2} photocatalyst exhibited a high photocatalytic activity for RhB degradation. Graphene-like MoS{sub 2} nanosheets. MoS{sub 2} nanosheets play an important role in photocatalytic activity by serving as an effective acceptor of the photogenerated carriers. - Abstract: A facile method for the in situ deposition of Ag{sub 3}PO{sub 4} on graphene-like MoS{sub 2} nanosheets was developed to improve the photocatalytic performance of Ag{sub 3}PO{sub 4} catalysts. The heterostructure of Ag{sub 3}PO{sub 4}/MoS{sub 2} composites was characterized by using X-ray diffraction spectra (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The prepared Ag{sub 3}PO{sub 4}/MoS{sub 2} photocatalyst exhibited a much higher photocatalytic activity than that of Ag{sub 3}PO{sub 4} for the degradation of Rhodamine B (RhB) under visible light irradiation (>400 nm). The improved photocatalytic activity of Ag{sub 3}PO{sub 4}/MoS{sub 2} is attributed to the efficient separation of photogenerated electronhole pairs in the composite. This result provides a new perspective on the design of high-performance photocatalysts which is promising for energy applications.

  7. Results of U-xMo (x=7, 10, 12 wt.%) Alloy versus Al-6061 Cladding Diffusion Couple Experiments Performed at 500, 550 and 600 Degrees C

    SciTech Connect (OSTI)

    Emmanuel Perez; Dennis D. Keiser, Jr.; Yongho Sohn

    2013-04-01

    The Reduced Enrichment for Research and Test Reactors (RERTR) program has been developing low enrichment fuel systems encased in Al 6061 for use in research and test reactors. U–Mo alloys in contact with Al and Al alloys can undergo diffusional interactions that can result in the development of interdiffusion zones with complex fine-grained microstructures composed of multiple phases. A monolithic fuel currently being developed by the RERTR program has local regions where the U–Mo fuel plate is in contact with the Al 6061 cladding and, as a result, the program finds information about interdiffusion zone development at high temperatures of interest. In this study, the microstructural development of diffusion couples consisting of U-7wt.%Mo, U-10wt.%Mo, and U-12wt.%Mo vs. Al 6061 (or 6061 aluminum) cladding, annealed at 500, 550, 600 degrees C for 1, 5, 20, 24, or 132 hours, was analyzed by backscatter electron microscopy and x-ray energy dispersive spectroscopy on a scanning electron microscope. Concentration profiles were determined by standardized wavelength dispersive spectroscopy and standardless x-ray energy dispersive spectroscopy. The results of this work shows that the presence of surface layers at the U–Mo/Al 6061 interface can dramatically impact the overall interdiffusion behavior in terms of rate of interaction and uniformity of the developed interdiffusion zones. It further reveals that relatively uniform interaction layers with higher Si concentrations can develop in U–Mo/Al 6061 couples annealed at shorter times and that longer times at temperature result in the development of more non-uniform interaction layers with more areas that are enriched in Al. At longer annealing times and relatively high temperatures, U–Mo/Al 6061 couples can exhibit more interaction compared to U–Mo/pure Al couples. The minor alloying constituents in Al 6061 cladding can result in the development of many complex phases in the interaction layer of U–Mo

  8. Low temperature carrier transport study of monolayer MoS{sub 2} field effect transistors prepared by chemical vapor deposition under an atmospheric pressure

    SciTech Connect (OSTI)

    Liu, Xinke E-mail: wujing026@gmail.com; He, Jiazhu; Tang, Dan; Lu, Youming; Zhu, Deliang; Liu, Wenjun; Cao, Peijiang; Han, Sun; Liu, Qiang; Wen, Jiao; Yu, Wenjie; Liu, Wenjun; Wu, Jing E-mail: wujing026@gmail.com; He, Zhubing; Ang, Kah-Wee

    2015-09-28

    Large size monolayer Molybdenum disulphide (MoS{sub 2}) was successfully grown by chemical vapor deposition method under an atmospheric pressure. The electrical transport properties of the fabricated back-gate monolayer MoS{sub 2} field effect transistors (FETs) were investigated under low temperatures; a peak field effect mobility of 59 cm{sup 2}V{sup −1}s{sup −1} was achieved. With the assist of Raman measurement under low temperature, this work identified the mobility limiting factor for the monolayer MoS{sub 2} FETs: homopolar phonon scattering under low temperature and electron-polar optical phonon scattering at room temperature.

  9. Cronifer 1925 hMo: A promising high-alloy steel for shelf oil and gas production

    SciTech Connect (OSTI)

    Rockel, M.; Jasner, M.

    1995-02-01

    The Cronifer 1925 hMo steel, which is known as a superaustenitic steel, possesses a high resistance toward pitting corrosion (PC), crevice corrosion (CC), and toward corrosion cracking (CoC) in media with a high chloride content and in hydrogen-sulfide-containing gases and condensates. The nominal chemical composition of Cronifer 1925 hMo is (%): < 0.02 C, 24.5-25.5 Ni, 20.0-21.0 Cr, < 1.0 Mn, < 0.5 Si, 0.8-1.0 Cu, 6.0-6.8 Mo, 0.18-0.20 N, < 0.005 S, and < 0.03 P. As a result of the high chromium and molybdenum content, the pitting resistance equivalent (PRE) is equal, according to the PRE equation to PRE = % Cr + 3.3% Mo - 30% N = 74%. A stainless steel is considered as corrosion-resisting in sea water at PRE {ge} 35%. The increased nickel content makes Cronifer 1925 hMo also resistant toward CoC under stress in sea water and in other media with high chloride contents, a well as in gas condensates which contain hydrogen sulfide. All this makes the steel effective for use in marine conditions and in media encountered in the shelf production of oil and gas. The addition of nickel preserves the austenitic structure and improves the passivation properties. Copper improves the resistance of the steel toward general corrosion in reducing media; however, too high a copper content is harmful when the steel is used in neutral chloride-containing solutions and must be limited (not higher than 1%). Cronifer 1925 hMo can be used in hydrocarbon production on the shelf in the following equipment: in fire-extinguishing systems which use fresh and sea water; in pipe systems which return the separated water and gases (with high chloride contents at high pressures and elevated temperatures) to the well in order to fill cavities or to maintain pressure; in separating and cooling equipment of gas and oil production platforms and in oil and gas refineries; and in underwater installations, collectors, and pipe systems, operating under pressure.

  10. Cobalt-doped Bi{sub 26}Mo{sub 10}O{sub 69}: Crystal structure and conductivity

    SciTech Connect (OSTI)

    Mikhailovskaya, Z.A.; Buyanova, E.S.; Petrova, S.A.; Morozova, M.V.; Zhukovskiy, V.M.; Zakharov, R.G.; Tarakina, N.V.; Berger, I.F.

    2013-08-15

    A series of cobalt-doped bismuth molybdates were synthesized and investigated using X-ray powder diffraction, transmission electron microscopy and impedance spectroscopy. The ranges of solid solution were determined. Two new compounds, Bi{sub 1?x}Co{sub x}[Bi{sub 12}O{sub 14}]Mo{sub 5}O{sub 34.5?} (x=0.2) and Bi[Bi{sub 12}O{sub 14}]Mo{sub 5?y}Co{sub y}O{sub 34.5?} (y=0.2), which crystallise in monoclinic unit cells have been examined in detail by diffraction methods. Impedance spectroscopy measurements show that the studied materials are good ionic conductors with conductivity values about 510{sup ?3} Scm{sup ?1} at 973 K and 1.710{sup ?4} Scm{sup ?1} at 623 K, which are similar to conductivity values of yttrium substituted zirconia and (YSZ) gadolinium doped ceria (CGO). - Graphical abstract: Measured and calculated diffraction spectra for Bi{sub 12.8}Co{sub 0.2}Mo{sub 5}O{sub 34?} and projection of the Bi{sub 12.8}Co{sub 0.2}Mo{sub 5}O{sub 34?} crystal structure onto the ac plane. Highlights: The limit of the Bi{sub 1?x}Co{sub x}[Bi{sub 12}O{sub 14}]Mo{sub 5}O{sub 34.5?} homogeneity range is equal to x=0.2. The limit of the Bi[Bi{sub 12}O{sub 14}]Mo{sub 5?y}Co{sub y}O{sub 34.5?} homogeneity range is equal to y=0.2. Solid solutions have monoclinic symmetry. No phase transition is observed. The conductivity at 700 for y=0.2 solid solutions is equal to ?lg ?, Scm{sup ?1}=2.23. The conductivity at 350 for y=0.2 solid solutions is equal to ?lg ?, Scm{sup ?1}=3.74.

  11. Development of an Immobilisation Technology for Radioactive Waste Solution from Mo-99 Production

    SciTech Connect (OSTI)

    Sizgek, G.D.; Sizgek, E.

    2006-07-01

    Australian Nuclear Science and Technology Organisation (ANSTO) developed a method to immobilize the Intermediate Level Liquid Waste (ILLW) arising from its Mo-99 production process. The immobilisation process involves impregnation of waste solution into ceramic precursor powders, drying, calcining and consolidation (Hot Isostatic Pressing, HIP) to produce final ceramic waste form. Ceramic precursor powder is produced by spray drying of a sol-gel based colloidal dispersion. These free-flowing, microspherical, 20-80 microns, precursors have porosity of 40-50%. An in-house custom designed and manufactured microwave-heated and mechanically fluidized mixer-drier was used for impregnation of the precursor powder with the simulated waste (Depleted Uranyl Nitrate Hexahydrate, DUNH, and inactive Cs, Sr nitrates as fission products) and drying. During impregnation an evaporation rate of 1 l/h water per kW microwave energy in steady state was achieved by matching the feed rate of DUNH to produce equivalent of 35% UO{sub 2} loading. It was demonstrated that the tuned microwave energy can be delivered to the mixer-drier during the entire impregnation process within very low reflection values. The samples of the waste loaded free-flowing powder were subsequently calcined at 750 deg. C under reducing atmosphere for thermal denitration and mineral phase nucleation. Calcined powders were filled into cans. After evacuation and sealing, the cans were isostatically pressed at 1260 deg. C. The consolidated ceramic waste form produced from the DUNH run has been assessed by durability and material characterization tests. Successful confirmation of each processing step at pilot and/or plant scale, has led to the design and construction of the overall process at full scale (equivalent of processing 8 kg U per batch) in a simulated hot-cell mock-up plant. The constructed plant mainly consists of a Microwave-heated Mechanical Fluidized Bed (MWMFB) mixer-drier a fluidized bed calciner, an off

  12. Microstructural evolution during solution treatment of Co-Cr-Mo-C biocompatible alloys

    SciTech Connect (OSTI)

    Giacchi, J.V.; Fornaro, O.; Palacio, H.

    2012-06-15

    Three different Co-Cr-Mo-C alloys conforming to ASTM F75 standard were poured in an industrial environment and subjected to a conventional solution treatment at 1225 Degree-Sign C for several time intervals. The microstructural changes and transformations were studied in each case in order to evaluate the way in which treatment time influences the secondary phase fraction and clarify the microstructural changes that could occur. To assess how treatment time affects microstructure, optical microscopy and image analyzer software, scanning electron microscopy and energy dispersion spectrometry analysis were employed. The main phases detected in the as-cast state were: {sigma}-phase, M{sub 6}C, and M{sub 23}C{sub 6} carbides. The latter presented two different morphologies, blocky type and lamellar type. Despite being considered the most detrimental feature to mechanical properties, {sigma}-phase and lamellar carbides dissolution took place in the early stages of solution treatment. M{sub 23}C{sub 6} carbides featured two different behaviors. In the alloy obtained by melting an appropriate quantity of alloyed commercial materials, a decrease in size, spheroidization and transformation into M{sub 6}C carbides were simultaneously observed. In the commercial ASTM F75 alloy, in turn, despite being the same phase, only a marked decrease in precipitates size was noticed. These different behaviors could be ascribed to the initial presence of other phases in the alloy obtained from alloyed materials, such as {sigma}-phase and 'pearlitic' carbides, or to the initial precipitate size which was much larger in the first than in the commercial ASTM F75 alloy studied. M{sub 6}C carbides dissolved directly in the matrix as they could not be detected in samples solution-treated for 15 min. - Highlights: Black-Right-Pointing-Pointer Three different Co-Cr-Mo alloys were poured under an industrial environment. Black-Right-Pointing-Pointer Transformation of existing phases followed during

  13. Production development and utilization of Zimmer Station wet FGD by-products. Final report. Volume 2, Product development of magnesium hydroxide, Phase 1

    SciTech Connect (OSTI)

    Smith, Kevin; Beeghly, Joel H.

    2000-11-30

    In the way of background information about 30 electric utility units with a combined total of 15,000 MW utilize magnesium enhanced lime flue gas desulfurization (FGD) systems. The first generation process begun in 1973, called the Thiosorbic® Process, was a technical breakthrough that offered significantly improved operating and performance characteristics compared with competing FGD technologies. The process is described as Flow Diagram "A" in figure 1. A disadvantage of this and other inhibited or natural oxidation wet FGD systems is the capital and operating cost associated with landfill disposal of the calcium sulfite based solids. Fixation to stabilize the sludge solids for compaction in a landfill also consumes fly ash that otherwise may be marketable.

  14. Fundamental studies of the metallurgical causes and mitigation of reheat cracking in 1{1/4}Cr-{1/2}Mo and 2{1/4}Cr-1Mo steels

    SciTech Connect (OSTI)

    Lundin, C.D.; Khan, K.K.

    1996-02-01

    Cr-Mo steels are considered to be susceptible to weld related reheat cracking. This study was instituted to determine the mechanisms for reheat cracking in these steels as well as to determine methods to successfully avoid reheat cracking. Two heats of 1{1/4}-{1/2}Mo were used, one being calcium treated. Also used were three heats of 2{1/4}Cr-1Mo, one being a conventional grade of 2{1/4}Cr-1Mo calcium treated; and the other two being modified (with {1/4}V) grades, one of which was calcium treated. The reheat cracking susceptibility of the materials was first determined by the Gleeble technique. Subsequently, a new simple and versatile test was developed--the spiral notch test. The materials were evaluated by this new test and a good correlation was found between the two tests. The results show a distinct difference in carbide evolution and segregation pattern for reheat crack susceptible and nonsusceptible heats. The M{sub 3}C type carbides persisted longer in reheat crack sensitive heats than in resistant heats. The M{sub 3}C type carbides transformed to M{sub 23}C{sub 6} type carbides earlier during PWHT. The prior austenite grain boundaries were enriched in P (susceptible) and in S (resistant) materials. Although the relation between the carbide evolution kinetics and the trace element segregation in affecting the reheat cracking susceptibility was not fully defined, it was obvious that the two were interlinked. The activation energy calculations revealed that diffusion of P was the rate controlling step for reheat cracking. Thus, all the results point to P as the principle element responsible for reheat cracking. 145 refs.

  15. Mass Measurements of Very Neutron-Deficient Mo and Tc Isotopes and Their Impact on rp Process Nucleosynthesis

    SciTech Connect (OSTI)

    Haettner, E.; Plass, W. R.; Scheidenberger, C.; Ackermann, D.; Block, M.; Eliseev, S.; Herfurth, F.; Hessberger, F. P.; Hofmann, S.; Kluge, H.-J.; Audi, G.; Blaum, K.; Ketter, J.; Fleckenstein, T.; Ketelaer, J.; Marx, G.; Schweikhard, L.; Mazzocco, M.; Novikov, Yu. N.; Vorobjev, G.

    2011-03-25

    The masses of ten proton-rich nuclides, including the N=Z+1 nuclides {sup 85}Mo and {sup 87}Tc, were measured with the Penning trap mass spectrometer SHIPTRAP. Compared to the Atomic Mass Evaluation 2003 a systematic shift of the mass surface by up to 1.6 MeV is observed causing significant abundance changes of the ashes of astrophysical x-ray bursts. Surprisingly low {alpha} separation energies for neutron-deficient Mo and Tc are found, making the formation of a ZrNb cycle in the rp process possible. Such a cycle would impose an upper temperature limit for the synthesis of elements beyond Nb in the rp process.

  16. Temperature dependent Raman spectroscopy of chemically derived few layer MoS{sub 2} and WS{sub 2} nanosheets

    SciTech Connect (OSTI)

    Thripuranthaka, M.; Kashid, Ranjit V.; Late, Dattatray J. E-mail: datta099@gmail.com; Sekhar Rout, Chandra

    2014-02-24

    We have systematically investigated the temperature dependent Raman spectroscopy behavior of a few layered MoS{sub 2} and WS{sub 2} nanosheets synthesized using simple hydrothermal method. Our result reveals A{sub 1g} and E{sup 1}{sub 2g} modes soften as temperature increases from 77 K to 623 K. This behavior can be explained in terms of a double resonance process which is active in single- and few layer thick nanosheets. The frequency shifts and peak broadening can provide unambiguous, nondestructive, and accurate information of a few layered MoS{sub 2} and WS{sub 2}. This mechanism can also be applicable in characterizing the structural, optical, electronic, and vibrational properties of other emerging layered materials.

  17. Excitons in a mirror: Formation of “optical bilayers” using MoS{sub 2} monolayers on gold substrates

    SciTech Connect (OSTI)

    Mertens, Jan; Baumberg, Jeremy J.; Shi, Yumeng; Yang, Hui Ying; Molina-Sánchez, Alejandro; Wirtz, Ludger

    2014-05-12

    We report coupling of excitons in monolayers of molybdenum disulphide to their mirror image in an underlying gold substrate. Excitons at the direct band gap are little affected by the substrate whereas strongly bound C-excitons associated with a van-Hove singularity change drastically. On quartz substrates only one C-exciton is visible (in the blue) but on gold substrates a strong red-shifted extra resonance in the green is seen. Exciton coupling to its image leads to formation of a “mirror biexciton” with enhanced binding energy. Estimates of this energy shift in an emitter-gold system match experiments well. The absorption spectrum of MoS{sub 2} on gold thus resembles a bilayer of MoS{sub 2} which has been created by optical coupling. Additional top-mirrors produce an “optical bulk.”.

  18. Feasibility study Part I - Thermal hydraulic analysis of LEU target for {sup 99}Mo production in Tajoura reactor

    SciTech Connect (OSTI)

    Bsebsu, F.M.; Abotweirat, F. E-mail: abutweirat@yahoo.com; Elwaer, S.

    2008-07-15

    The Renewable Energies and Water Desalination Research Center (REWDRC), Libya, will implement the technology for {sup 99}Mo isotope production using LEU foil target, to obtain new revenue streams for the Tajoura nuclear research reactor and desiring to serve the Libyan hospitals by providing the medical radioisotopes. Design information is presented for LEU target with irradiation device and irradiation Beryllium (Be) unit in the Tajoura reactor core. Calculated results for the reactor core with LEU target at different level of power are presented for steady state and several reactivity induced accident situations. This paper will present the steady state thermal hydraulic design and transient analysis of Tajoura reactor was loaded with LEU foil target for {sup 99}Mo production. The results of these calculations show that the reactor with LEU target during the several cases of transient are in safe and no problems will occur. (author)

  19. Characterization of mechanical nanocrystallization process of amorphous Fe{endash}Mo{endash}Si{endash}B alloy by transmission Moessbauer spectroscopy

    SciTech Connect (OSTI)

    Liu, X.D.; Lu, K.; Umemoto, M.

    1997-03-01

    The nanocrystallization process of the amorphous Fe{endash}Mo{endash}Si{endash}B alloy under ball milling is characterization by means of transmission M{umlt o}ssbauer spectroscopy in the present paper. It was found that a single {alpha}-Fe phase with the bcc structure is formed under ball-milling the amorphous Fe{endash}Mo{endash}Si{endash}B alloy. A significant increase in the relative area of the subspectra of 8 Fenn and 7 Fenn and a remarkable decrease in isomer shift and half linewidth of the subspectra of various Fe configurations, especially in the case of 6 Fenn, were observed during the ball milling process. The diffusion of metalloid atoms from the bcc {alpha}-Fe phase to the remaining amorphous phase and {alpha}-Fe/{alpha}-Fe grain boundaries is suggested to occur during the mechanical crystallization of the current amorphous alloy based on the above TMES investigations. {copyright} {ital 1997 Materials Research Society.}

  20. Discovery of an unconventional charge density wave at the surface of K0.9Mo6O17

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

    Mou, Daixiang; Sapkota, Aashish; Kung, H. -H.; Krapivin, Viktor; Wu, Yun; Kreyssig, A.; Zhou, Xingjiang; Goldman, A. I.; Blumberg, G.; Flint, Rebecca; et al

    2016-05-13

    In this study, we use angle resolved photoemission spectroscopy, Raman spectroscopy, low energy electron diffraction, and x-ray scattering to reveal an unusual electronically mediated charge density wave (CDW) in K0.9Mo6O17. Not only does K0.9Mo6O17 lack signatures of electron-phonon coupling, but it also hosts an extraordinary surface CDW, with TS_CDW = 220 K nearly twice that of the bulk CDW, TB_CDW = 115 K. While the bulk CDW has a BCS-like gap of 12 meV, the surface gap is 10 times larger and well in the strong coupling regime. Strong coupling behavior combined with the absence of signatures of strong electron-phononmore » coupling indicates that the CDW is likely mediated by electronic interactions enhanced by low dimensionality.« less