National Library of Energy BETA

Sample records for ther mal decomposition

  1. Step-by-step thermal transformations of a new porous coordination polymer [(H{sub 2}O){sub 5}CuBa(Me{sub 2}mal){sub 2}]{sub n} (Me{sub 2}mal{sup 2-}=dimethylmalonate): Thermal degradation to barium cuprate

    SciTech Connect (OSTI)

    Zauzolkova, Natalya; Dobrokhotova, Zhanna; Lermontov, Anatoly; Zorina, Ekaterina; Emelina, Anna; Bukov, Mikhail; Sidorov, Aleksey; Kiskin, Mikhail; Bogomyakov, Artem; Lytvynenko, Anton; Kolotilov, Sergey; Velikodnyi, Yuriy; Kovba, Maksim

    2013-01-15

    The reactions of CuSO{sub 4}{center_dot}5H{sub 2}O, dimethylmalonic acid and Ba(OH){sub 2}{center_dot}H{sub 2}O (Cu: H{sub 2}Me{sub 2}mal: Ba=1: 2: 2) in aqueous and aqueous-ethanol solutions (H{sub 2}O: EtOH=1: 1) resulted in formation of 3D-porous coordination polymers [(H{sub 2}O){sub 3}({mu}-H{sub 2}O){sub 2}CuBa({mu}{sub 3}-Me{sub 2}mal)(Me{sub 2}mal)]{sub n} (1) and [({mu}-H{sub 2}O)CuBa({mu}{sub 3}-Me{sub 2}mal)({mu}{sub 4}-Me{sub 2}mal)]{sub n} (2), respectively. It has been shown that compound 2 was an intermediate in the thermal degradation of compound 1. Thorough studies of solid-state thermolysis of 1 and 2 allowed to detect formation of coordination polymer [CuBa({mu}{sub 4}-Me{sub 2}mal)({mu}{sub 5}-Me{sub 2}mal)]{sub n} (3), structure of which was determined by X-ray powder diffraction. It has been found that the channels in polymer 3 were accessible for guest molecules (MeOH). Theoretical estimation of methanol diffusion barrier was carried out. Complete solid-phase thermolysis of 1 and 2 leads to a mixture of BaCuO{sub 2}, BaCO{sub 3}, and CuO. Special conditions for obtaining of a crystalline phase of pure cubic BaCuO{sub 2} were determined. - Graphical abstract: Step-by-step transformation of new coordination polymer [(H{sub 2}O){sub 5}CuBa(Me{sub 2}mal){sub 2}]{sub n} to [(H{sub 2}O)CuBa(Me{sub 2}mal){sub 2}]{sub n} and [CuBa(Me{sub 2}mal){sub 2}]{sub n} were performed. Dehydration of initial compound leads to structural changes of 12-membered ring fragment. All compounds have porous structure. The final product of thermal decomposition is crystalline phase of individual cubic BaCuO{sub 2}. Highlights: Black-Right-Pointing-Pointer New 3D-polymers [(H{sub 2}O){sub 5}CuBa(Me{sub 2}mal){sub 2}]{sub n} and [(H{sub 2}O)CuBa(Me{sub 2}mal){sub 2}]{sub n} were synthesized. Black-Right-Pointing-Pointer Thermal analysis showed step-by-step transformations of [(H{sub 2}O){sub 5}CuBa(Me{sub 2}mal){sub 2}]{sub n}. Black-Right-Pointing-Pointer Crystalline phase of pure cubic BaCuO{sub 2} is the product solid-phase thermolysis.

  2. Hydrogen iodide decomposition

    DOE Patents [OSTI]

    O'Keefe, Dennis R. (San Diego, CA); Norman, John H. (San Diego, CA)

    1983-01-01

    Liquid hydrogen iodide is decomposed to form hydrogen and iodine in the presence of water using a soluble catalyst. Decomposition is carried out at a temperature between about 350.degree. K. and about 525.degree. K. and at a corresponding pressure between about 25 and about 300 atmospheres in the presence of an aqueous solution which acts as a carrier for the homogeneous catalyst. Various halides of the platinum group metals, particularly Pd, Rh and Pt, are used, particularly the chlorides and iodides which exhibit good solubility. After separation of the H.sub.2, the stream from the decomposer is countercurrently extracted with nearly dry HI to remove I.sub.2. The wet phase contains most of the catalyst and is recycled directly to the decomposition step. The catalyst in the remaining almost dry HI-I.sub.2 phase is then extracted into a wet phase which is also recycled. The catalyst-free HI-I.sub.2 phase is finally distilled to separate the HI and I.sub.2. The HI is recycled to the reactor; the I.sub.2 is returned to a reactor operating in accordance with the Bunsen equation to create more HI.

  3. Erbium hydride decomposition kinetics.

    SciTech Connect (OSTI)

    Ferrizz, Robert Matthew

    2006-11-01

    Thermal desorption spectroscopy (TDS) is used to study the decomposition kinetics of erbium hydride thin films. The TDS results presented in this report are analyzed quantitatively using Redhead's method to yield kinetic parameters (E{sub A} {approx} 54.2 kcal/mol), which are then utilized to predict hydrogen outgassing in vacuum for a variety of thermal treatments. Interestingly, it was found that the activation energy for desorption can vary by more than 7 kcal/mol (0.30 eV) for seemingly similar samples. In addition, small amounts of less-stable hydrogen were observed for all erbium dihydride films. A detailed explanation of several approaches for analyzing thermal desorption spectra to obtain kinetic information is included as an appendix.

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

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

    Ghimire, N. J.; Ronning, F.; Williams, D. J.; Scott, B. L.; Luo, Yongkang; Thompson, J. D.; Bauer, E. D.

    2014-12-15

    The synthesis, crystal structure and physical properties studied by means of x-ray diffraction, magnetic, thermal and transport measurements of CeMAl4Si2 (M = Rh, Ir, Pt) are reported, along with the electronic structure calculations for LaMAl4Si2 (M = Rh, Ir, Pt). These materials adopt a tetragonal crystal structure (space group P4/mmm) comprised of BaAl4 blocks, separated by MAl2 units, stacked along the c-axis. Both CeRhAl4Si2 and CeIrAl4Si2 order antiferromagnetically below TN1 = 14 and 16 K, respectively, and undergo a second antiferromagnetic transitition at lower temperature (TN2 = 9 and 14 K, respectively). CePtAl4Si2 orders ferromagnetically below TC = 3 Kmore » with an ordered moment of μsat = 0.8 μB for a magnetic field applied perpendicular to the c-axis. Electronic structure calculations reveal quasi-2D character of the Fermi surface.« less

  5. Anisotropic decomposition of energetic materials

    SciTech Connect (OSTI)

    Pravica, Michael; Quine, Zachary; Romano, Edward; Bajar, Sean; Yulga, Brian; Yang Wenge; Hooks, Daniel

    2007-12-12

    Using a white x-ray synchrotron beam, we have dynamically studied radiation-induced decomposition in single crystalline PETN and TATB. By monitoring the integrated intensity of selected diffraction spots via a CCD x-ray camera as a function of time, we have found that the decomposition rate varies dramatically depending upon the orientation of the crystalline axes relative to polarized x-ray beam and for differing diffracting conditions (spots) within the same crystalline orientation. We suggest that this effect is due to Compton scattering of the polarized x-rays with electron clouds that is dependent upon their relative orientation. This novel effect may yield valuable insight regarding anisotropic detonation sensitivity in energetic materials such as PETN.

  6. Anisotropic Decomposition of Energetic Materials

    SciTech Connect (OSTI)

    Pravica, Michael; Quine, Zachary; Romano, Edward; Bajar, Sean; Yulga, Brian; Yang, Wenge; Hooks, Daniel

    2008-01-17

    Using a white x-ray synchrotron beam, we have dynamically studied radiation-induced decomposition in single crystalline PETN and TATB. By monitoring the integrated intensity of selected diffraction spots via a CCD x-ray camera as a function of time, we have found that the decomposition rate varies dramatically depending upon the orientation of the crystalline axes relative to polarized x-ray beam and for differing diffracting conditions (spots) within the same crystalline orientation. We suggest that this effect is due to Compton scattering of the polarized x-rays with electron clouds that is dependent upon their relative orientation. This novel effect may yield valuable insight regarding anisotropic detonation sensitivity in energetic materials such as PETN.

  7. Decomposition Studies of Tetraphenylborate Slurries

    SciTech Connect (OSTI)

    Crawford, C.L.

    1997-05-06

    This report details the decomposition of aqueous (K,Na) slurries in concentrated salt solutions using a more complete candidate catalyst recipe, extended testing temperatures (40-70 degrees C) and test durations of approximately 1500 hours (9 weeks). This study uses recently developed High-Pressure Liquid Chromatography (HPLC) methods for analysis of tetraphenylborate (TPB-), triphenylborane (3PB) and diphenylborinic acid (2PB). All of the present tests involve non-radioactive simulants and do not include investigations of radiolysis effects.

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

    SciTech Connect (OSTI)

    Ghimire, N. J.; Ronning, F.; Williams, D. J.; Scott, B. L.; Luo, Yongkang; Thompson, J. D.; Bauer, E. D.

    2014-12-15

    The synthesis, crystal structure and physical properties studied by means of x-ray diffraction, magnetic, thermal and transport measurements of CeMAl4Si2 (M = Rh, Ir, Pt) are reported, along with the electronic structure calculations for LaMAl4Si2 (M = Rh, Ir, Pt). These materials adopt a tetragonal crystal structure (space group P4/mmm) comprised of BaAl4 blocks, separated by MAl2 units, stacked along the c-axis. Both CeRhAl4Si2 and CeIrAl4Si2 order antiferromagnetically below TN1 = 14 and 16 K, respectively, and undergo a second antiferromagnetic transitition at lower temperature (TN2 = 9 and 14 K, respectively). CePtAl4Si2 orders ferromagnetically below TC = 3 K with an ordered moment of ?sat = 0.8 ?B for a magnetic field applied perpendicular to the c-axis. Electronic structure calculations reveal quasi-2D character of the Fermi surface.

  9. Modeling decomposition of rigid polyurethane foam

    SciTech Connect (OSTI)

    Hobbs, M.L.

    1998-01-01

    Rigid polyurethane foams are used as encapsulants to isolate and support thermally sensitive components within weapon systems. When exposed to abnormal thermal environments, such as fire, the polyurethane foam decomposes to form products having a wide distribution of molecular weights and can dominate the overall thermal response of the system. Decomposing foams have either been ignored by assuming the foam is not present, or have been empirically modeled by changing physical properties, such as thermal conductivity or emissivity, based on a prescribed decomposition temperature. The hypothesis addressed in the current work is that improved predictions of polyurethane foam degradation can be realized by using a more fundamental decomposition model based on chemical structure and vapor-liquid equilibrium, rather than merely fitting the data by changing physical properties at a prescribed decomposition temperature. The polyurethane decomposition model is founded on bond breaking of the primary polymer and formation of a secondary polymer which subsequently decomposes at high temperature. The bond breaking scheme is resolved using percolation theory to describe evolving polymer fragments. The polymer fragments vaporize according to individual vapor pressures. Kinetic parameters for the model were obtained from Thermal Gravimetric Analysis (TGA) from a single nonisothermal experiment with a heating rate of 20 C/min. Model predictions compare reasonably well with a separate nonisothermal TGA weight loss experiment with a heating rate of 200 C/min.

  10. Decomposition of amino diazeniumdiolates (NONOates): Molecular mechanisms

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

    Shaikh, Nizamuddin; Valiev, Marat; Lymar, Sergei V.

    2014-08-23

    Although diazeniumdiolates (X[N(O)NO]-) are extensively used in biochemical, physiological, and pharmacological studies due to their ability to release NO and/or its congeneric nitroxyl, the mechanisms of these processes remain obscure. In this work, we used a combination of spectroscopic, kinetic, and computational techniques to arrive at a quantitatively consistent molecular mechanism for decomposition of amino diazeniumdiolates (amino NONOates: R2N[N(O)NO]-, where R = —N(C2H5)2(1), —N(C3H4NH2)2(2), or —N(C2H4NH2)2(3)). Decomposition of these NONOates is triggered by protonation of their [NN(O)NO]- group with the apparent pKa and decomposition rate constants of 4.6 and 1 s-1 for 1; 3.5 and 0.083 s-1 for 2; andmore » 3.8 and 0.0033 s-1 for 3. Although protonation occurs mainly on the O atoms of the functional group, only the minor R2N(H)N(O)NO tautomer (population ~ 10-7, for 1) undergoes the N—N heterolytic bond cleavage (kd ~ 107 s-1 for 1) leading to amine and NO. Decompositions of protonated amino NONOates are strongly temperature-dependent; activation enthalpies are 20.4 and 19.4 kcal/mol for 1 and 2, respectively, which includes contributions from both the tautomerization and bond cleavage. Thus, the bond cleavage rates exhibit exceptional sensitivity to the nature of R substituents which strongly modulate activation entropy. At pH < 2, decompositions of all three NONOates that have been investigated are subject to additional acid catalysis that occurs through di-protonation of the [NN(O)NO]- group.« less

  11. Decomposition of Amino Diazeniumdiolates (NONOates): Molecular Mechanisms

    SciTech Connect (OSTI)

    Shaikh, Nizamuddin; Valiev, Marat; Lymar, Sergei V.

    2014-08-23

    Although diazeniumdiolates (X[N(O)NO]-) are extensively used in biochemical, physiological, and pharmacological studies due to their ability to slowly release NO and/or its congeneric nitroxyl, the mechanisms of these processes remain obscure. In this work, we used a combination of spectroscopic, kinetic, and computational techniques to arrive at a qualitatively consistent molecular mechanism for decomposition of amino diazeniumdiolates (amino NONOates: R2N[N(O)NO]-, where R = -N(C2H5)2 (1), -N(C3H4NH2)2 (2), or -N(C2H4NH2)2 (3)). Decomposition of these NONOates is triggered by protonation of their [NN(O)NO]- group with apparent pKa and decomposition rate constants of 4.6 and 1 s-1 for 1-H, 3.5 and 83 x 10-3 s-1 for 2-H, and 3.8 and 3.3 x 10-3 s-1 for 3-H. Although protonation occurs mainly on the O atoms of the functional group, only the minor R2N(H)N(O)NO tautomer (population ~0.01%, for 1) undergoes the N-N heterolytic bond cleavage (k ~102 s-1 for 1) leading to amine and NO. Decompositions of protonated amino NONOates are strongly temperature-dependent; activation enthalpies are 20.4 and 19.4 kcal/mol for 1 and 2, respectively, which includes contributions from both the tautomerization and bond cleavage. The bond cleavage rates exhibit exceptional sensitivity to the nature of R substituents which strongly modulate activation entropy. At pH < 2, decompositions of all these NONOates are subject to additional acid catalysis that occurs through di-protonation of the [NN(O)NO]- group.

  12. Adomian Decomposition Method for Quark Gluon Plasma Model

    SciTech Connect (OSTI)

    Constantinescu, Radu; Ionescu, Carmen; Stoicescu, Mihai

    2011-10-03

    The paper investigates the possibility of obtaining analytical solutions for the Quark Gluon Plasma model using the Adomian decomposition method.

  13. Manganese Reduction-Oxidation Drives Plant Debris Decomposition

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

    Manganese Reduction-Oxidation Drives Plant Debris Decomposition Manganese Reduction-Oxidation Drives Plant Debris Decomposition Print Monday, 22 February 2016 00:00 Microbial decomposition of plant debris ("litter") is a keystone ecosystem process because it regulates nutrient availability, ecosystem productivity, and carbon (C) cycling. Historically, climate (primarily temperature and precipitation) has been thought to regulate the rate of litter decomposition, which then influences

  14. ADVANCED OXIDATION: OXALATE DECOMPOSITION TESTING WITH OZONE

    SciTech Connect (OSTI)

    Ketusky, E.; Subramanian, K.

    2012-02-29

    At the Savannah River Site (SRS), oxalic acid is currently considered the preferred agent for chemically cleaning the large underground Liquid Radioactive Waste Tanks. It is applied only in the final stages of emptying a tank when generally less than 5,000 kg of waste solids remain, and slurrying based removal methods are no-longer effective. The use of oxalic acid is preferred because of its combined dissolution and chelating properties, as well as the fact that corrosion to the carbon steel tank walls can be controlled. Although oxalic acid is the preferred agent, there are significant potential downstream impacts. Impacts include: (1) Degraded evaporator operation; (2) Resultant oxalate precipitates taking away critically needed operating volume; and (3) Eventual creation of significant volumes of additional feed to salt processing. As an alternative to dealing with the downstream impacts, oxalate decomposition using variations of ozone based Advanced Oxidation Process (AOP) were investigated. In general AOPs use ozone or peroxide and a catalyst to create hydroxyl radicals. Hydroxyl radicals have among the highest oxidation potentials, and are commonly used to decompose organics. Although oxalate is considered among the most difficult organic to decompose, the ability of hydroxyl radicals to decompose oxalate is considered to be well demonstrated. In addition, as AOPs are considered to be 'green' their use enables any net chemical additions to the waste to be minimized. In order to test the ability to decompose the oxalate and determine the decomposition rates, a test rig was designed, where 10 vol% ozone would be educted into a spent oxalic acid decomposition loop, with the loop maintained at 70 C and recirculated at 40L/min. Each of the spent oxalic acid streams would be created from three oxalic acid strikes of an F-area simulant (i.e., Purex = high Fe/Al concentration) and H-area simulant (i.e., H area modified Purex = high Al/Fe concentration) after nearing dissolution equilibrium, and then decomposed to {le} 100 Parts per Million (ppm) oxalate. Since AOP technology largely originated on using ultraviolet (UV) light as a primary catalyst, decomposition of the spent oxalic acid, well exposed to a medium pressure mercury vapor light was considered the benchmark. However, with multi-valent metals already contained in the feed, and maintenance of the UV light a concern; testing was conducted to evaluate the impact from removing the UV light. Using current AOP terminology, the test without the UV light would likely be considered an ozone based, dark, ferrioxalate type, decomposition process. Specifically, as part of the testing, the impacts from the following were investigated: (1) Importance of the UV light on the decomposition rates when decomposing 1 wt% spent oxalic acid; (2) Impact of increasing the oxalic acid strength from 1 to 2.5 wt% on the decomposition rates; and (3) For F-area testing, the advantage of increasing the spent oxalic acid flowrate from 40 L/min (liters/minute) to 50 L/min during decomposition of the 2.5 wt% spent oxalic acid. The results showed that removal of the UV light (from 1 wt% testing) slowed the decomposition rates in both the F & H testing. Specifically, for F-Area Strike 1, the time increased from about 6 hours to 8 hours. In H-Area, the impact was not as significant, with the time required for Strike 1 to be decomposed to less than 100 ppm increasing slightly, from 5.4 to 6.4 hours. For the spent 2.5 wt% oxalic acid decomposition tests (all) without the UV light, the F-area decompositions required approx. 10 to 13 hours, while the corresponding required H-Area decompositions times ranged from 10 to 21 hours. For the 2.5 wt% F-Area sludge, the increased availability of iron likely caused the increased decomposition rates compared to the 1 wt% oxalic acid based tests. In addition, for the F-testing, increasing the recirculation flow rates from 40 liter/minute to 50 liter/minute resulted in an increased decomposition rate, suggesting a better use of ozone.

  15. conformal decomposition finite-element method

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

    conformal decomposition finite-element method - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Fuel Cycle Defense Waste

  16. Perspectives on Pentaerythritol Tetranitrate (PETN) Decomposition

    SciTech Connect (OSTI)

    Chambers, D; Brackett, C; Sparkman, D O

    2002-07-01

    This report evaluates the large body of work involving the decomposition of PETN and identifies the major decomposition routes and byproducts. From these studies it becomes apparent that the PETN decomposition mechanisms and the resulting byproducts are primarily determined by the chemical environment. In the absence of water, PETN can decompose through the scission of the O-NO{sup 2} bond resulting in the formation of an alkoxy radical and NO{sub 2}. Because of the relatively high reactivity of both these initial byproducts, they are believed to drive a number of autocatalytic reactions eventually forming (NO{sub 2}OCH{sub 2}){sub 3}CCHO, (NO{sub 2}OCH{sub 2}){sub 2}C=CHONO{sub 2}, NO{sub 2}OCH=C=CHONO{sub 2}, (NO{sub 2}OCH{sub 2}){sub 3}C-NO{sub 2}, (NO{sub 2}OCH{sub 2}){sub 2}C(NO{sub 2}){sub 2}, NO{sub 2}OCH{sub 2}C(NO{sub 2}){sub 3}, and C(NO{sub 2}){sub 4} as well as polymer-like species such as di-PEHN and tri-PEON. Surprisingly, the products of many of these proposed autocatalytic reactions have never been analytically validated. Conversely, in the presence of water, PETN has been shown to decompose primarily to mono, di, and tri nitrates of pentaerythritol.

  17. Decomposition of amino diazeniumdiolates (NONOates): Molecular mechanisms

    SciTech Connect (OSTI)

    Shaikh, Nizamuddin; Valiev, Marat; Lymar, Sergei V.

    2014-12-01

    Although diazeniumdiolates (X[N(O)NO]-) are extensively used in biochemical, physiological, and pharmacological studies due to their ability to release NO and/or its congeneric nitroxyl, the mechanisms of these processes remain obscure. In this work, we used a combination of spectroscopic, kinetic, and computational techniques to arrive at a quantitatively consistent molecular mechanism for decomposition of amino diazeniumdiolates (amino NONOates: R2N[N(O)NO]-, where R = N(C2H5)2(1), N(C3H4NH2)2(2), or N(C2H4NH2)2(3)). Decomposition of these NONOates is triggered by protonation of their [NN(O)NO]- group with the apparent pKa and decomposition rate constants of 4.6 and 1 s-1 for 1; 3.5 and 0.083 s-1 for 2; and 3.8 and 0.0033 s-1 for 3. Although protonation occurs mainly on the O atoms of the functional group, only the minor R2N(H)N(O)NO tautomer (population ~ 10-7, for 1) undergoes the NN heterolytic bond cleavage (kd ~ 107 s-1 for 1) leading to amine and NO. Decompositions of protonated amino NONOates are strongly temperature-dependent; activation enthalpies are 20.4 and 19.4 kcal/mol for 1 and 2, respectively, which includes contributions from both the tautomerization and bond cleavage. The bond cleavage rates exhibit exceptional sensitivity to the nature of R substituents which strongly modulate activation entropy. At pH < 2, decompositions of all three NONOates that have been investigated are subject to additional acid catalysis that occurs through di-protonation of the [NN(O)NO]- group.

  18. Radiation-induced decomposition of PETN and TATB under pressure

    SciTech Connect (OSTI)

    Giefers, Hubertus; Pravica, Michael; Liermann, Hanns-Peter; Yang, Wenge

    2008-10-02

    We have investigated decomposition of PETN and TATB induced by white synchrotron X-ray radiation in a diamond anvil cell at ambient temperature and two pressures, nearly ambient and about 6 GPa. The decomposition rate of TATB decreases significantly when it is pressurized to 5.9 GPa. The measurements were highly reproducible and allowed us to obtain decomposition rates and the order parameters of the reactions.

  19. Manganese Reduction-Oxidation Drives Plant Debris Decomposition

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

    Manganese Reduction-Oxidation Drives Plant Debris Decomposition Print Microbial decomposition of plant debris ("litter") is a keystone ecosystem process because it regulates nutrient availability, ecosystem productivity, and carbon (C) cycling. Historically, climate (primarily temperature and precipitation) has been thought to regulate the rate of litter decomposition, which then influences the rate at which nutrients become available and C contained in the litter is released back into

  20. Manganese Reduction-Oxidation Drives Plant Debris Decomposition

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

    Manganese Reduction-Oxidation Drives Plant Debris Decomposition Print Microbial decomposition of plant debris ("litter") is a keystone ecosystem process because it regulates nutrient availability, ecosystem productivity, and carbon (C) cycling. Historically, climate (primarily temperature and precipitation) has been thought to regulate the rate of litter decomposition, which then influences the rate at which nutrients become available and C contained in the litter is released back into

  1. Manganese Reduction-Oxidation Drives Plant Debris Decomposition

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

    Manganese Reduction-Oxidation Drives Plant Debris Decomposition Print Microbial decomposition of plant debris ("litter") is a keystone ecosystem process because it regulates nutrient availability, ecosystem productivity, and carbon (C) cycling. Historically, climate (primarily temperature and precipitation) has been thought to regulate the rate of litter decomposition, which then influences the rate at which nutrients become available and C contained in the litter is released back into

  2. Manganese Reduction-Oxidation Drives Plant Debris Decomposition

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

    Manganese Reduction-Oxidation Drives Plant Debris Decomposition Print Microbial decomposition of plant debris ("litter") is a keystone ecosystem process because it regulates nutrient availability, ecosystem productivity, and carbon (C) cycling. Historically, climate (primarily temperature and precipitation) has been thought to regulate the rate of litter decomposition, which then influences the rate at which nutrients become available and C contained in the litter is released back into

  3. Solid Double-Layered Hydroxide Catalysts for Lignin Decomposition...

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

    Biomass and Biofuels Biomass and Biofuels Find More Like This Return to Search Solid Double-Layered Hydroxide Catalysts for Lignin Decomposition National Renewable Energy...

  4. Effect of Palladium Form on Tetraphenylborate Decomposition Rate

    SciTech Connect (OSTI)

    Walker, D.D.

    1998-04-28

    Palladium catalyzes the decomposition of tetraphenylborate in alkaline solutions. Researchers postulate several decomposition mechanisms that differ in the form of the palladium catalyst. Potential forms include solid and soluble, different soluble species (such as aqueous or organic soluble), and different oxidation states (i.e., 0, II, and IV). Initial tests measured the reactivity and distribution of four Pd forms in tetraphenylborate slurries.

  5. Integrated Network Decompositions and Dynamic Programming for Graph Optimization (INDDGO)

    Energy Science and Technology Software Center (OSTI)

    2012-05-31

    The INDDGO software package offers a set of tools for finding exact solutions to graph optimization problems via tree decompositions and dynamic programming algorithms. Currently the framework offers serial and parallel (distributed memory) algorithms for finding tree decompositions and solving the maximum weighted independent set problem. The parallel dynamic programming algorithm is implemented on top of the MADNESS task-based runtime.

  6. Radiation-induced decomposition of explosives under extreme conditions

    SciTech Connect (OSTI)

    Giefers, Hubertus; Pravica, Michael; Yang, Wenge; Liermann, Peter

    2008-11-03

    We present high-pressure and high temperature studies of the synchrotron radiation-induced decomposition of powder secondary high explosives pentaerythritol tetranitrate (PETN) and 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) using white beam synchrotron radiation at the 16 BM-B and 16 BM-D sectors of the HP-CAT beamline at the Advanced Photon Source. The radiation-induced decomposition rate TATB showed dramatic slowing with pressure up to 26.6 GPa (the highest pressure studied), implying a positive activation volume of the activated complex. The decomposition rate of PETN varied little with pressure up to 15.7 GPa (the highest pressure studied). Diffraction line intensities were measured as a function of time using energy-dispersive methods. By measuring the decomposition rate as a function of pressure and temperature, kinetic and other constants associated with the decomposition reactions were extracted.

  7. Hydrogen production by the decomposition of water

    DOE Patents [OSTI]

    Hollabaugh, Charles M.; Bowman, Melvin G.

    1981-01-01

    How to produce hydrogen from water was a problem addressed by this invention. The solution employs a combined electrolytical-thermochemical sulfuric acid process. Additionally, high purity sulfuric acid can be produced in the process. Water and SO.sub.2 react in electrolyzer (12) so that hydrogen is produced at the cathode and sulfuric acid is produced at the anode. Then the sulfuric acid is reacted with a particular compound M.sub.r X.sub.s so as to form at least one water insoluble sulfate and at least one water insoluble oxide of molybdenum, tungsten, or boron. Water is removed by filtration; and the sulfate is decomposed in the presence of the oxide in sulfate decomposition zone (21), thus forming SO.sub.3 and reforming M.sub.r X.sub.s. The M.sub.r X.sub.s is recycled to sulfate formation zone (16). If desired, the SO.sub.3 can be decomposed to SO.sub.2 and O.sub.2 ; and the SO.sub.2 can be recycled to electrolyzer (12) to provide a cycle for producing hydrogen.

  8. Pressure Dependent Decomposition Kinetics of the Energetic Material...

    Office of Scientific and Technical Information (OSTI)

    Kinetics of the Energetic Material HMX up to 3.6 GPa The effect of pressure on the thermal decomposition rate of the energetic material HMX was studied. HMX was...

  9. Hydrogen production by the decomposition of water

    DOE Patents [OSTI]

    Hollabaugh, C.M.; Bowman, M.G.

    A process is described for the production of hydrogen from water by a sulfuric acid process employing electrolysis and thermo-chemical decomposition. The water containing SO/sub 2/ is electrolyzed to produce H/sub 2/ at the cathode and to oxidize the SO/sub 2/ to form H/sub 2/SO/sub 4/ at the anode. After the H/sub 2/ has been separated, a compound of the type M/sub r/X/sub s/ is added to produce a water insoluble sulfate of M and a water insoluble oxide of the metal in the radical X. In the compound M/sub r/X/sub s/, M is at least one metal selected from the group consisting of Ba/sup 2 +/, Ca/sup 2 +/, Sr/sup 2 +/, La/sup 2 +/, and Pb/sup 2 +/; X is at least one radical selected from the group consisting of molybdate (MoO/sub 4//sup 2 -/), tungstate (WO/sub 4//sup 2 -/), and metaborate (BO/sub 2//sup 1 -/); and r and s are either 1, 2, or 3 depending upon the valence of M and X. The precipitated mixture is filtered and heated to a temperature sufficiently high to form SO/sub 3/ gas and to reform M/sub r/X/sub s/. The SO/sub 3/ is dissolved in a small amount of H/sub 2/O to produce concentrated H/sub 2/SO/sub 4/, and the M/sub r/X/sub s/ is recycled to the process. Alternatively, the SO/sub 3/ gas can be recycled to the beginning of the process to provide a continuous process for the production of H/sub 2/ in which only water need be added in a substantial amount. (BLM)

  10. Urea Decomposition and SCR Performance at Low Temperature | Department of

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

    Energy Decomposition and SCR Performance at Low Temperature Urea Decomposition and SCR Performance at Low Temperature 2004 Diesel Engine Emissions Reduction (DEER) Conference Presentation: Oak Ridge National Laboratory PDF icon 2004_deer_sluder.pdf More Documents & Publications Fuel-Borne Reductants for NOx Aftertreatment: Preliminary EtOH SCR Study CLEERS Coordination & Joint Development of Benchmark Kinetics for LNT & SCR Development of Optimal Catalyst Designs and Operating

  11. In vivo subcellular localization of Mal de Rio Cuarto virus (MRCV) non-structural proteins in insect cells reveals their putative functions

    SciTech Connect (OSTI)

    Maroniche, Guillermo A.; Mongelli, Vanesa C.; Llauger, Gabriela; Alfonso, Victoria; Taboga, Oscar

    2012-09-01

    The in vivo subcellular localization of Mal de Rio Cuarto virus (MRCV, Fijivirus, Reoviridae) non-structural proteins fused to GFP was analyzed by confocal microscopy. P5-1 showed a cytoplasmic vesicular-like distribution that was lost upon deleting its PDZ binding TKF motif, suggesting that P5-1 interacts with cellular PDZ proteins. P5-2 located at the nucleus and its nuclear import was affected by the deletion of its basic C-termini. P7-1 and P7-2 also entered the nucleus and therefore, along with P5-2, could function as regulators of host gene expression. P6 located in the cytoplasm and in perinuclear cloud-like inclusions, was driven to P9-1 viroplasm-like structures and co-localized with P7-2, P10 and {alpha}-tubulin, suggesting its involvement in viroplasm formation and viral intracellular movement. Finally, P9-2 was N-glycosylated and located at the plasma membrane in association with filopodia-like protrusions containing actin, suggesting a possible role in virus cell-to-cell movement and spread.

  12. Thermal Decomposition of IMX-104: Ingredient Interactions Govern Thermal Insensitivity

    SciTech Connect (OSTI)

    Maharrey, Sean; Wiese-Smith, Deneille; Highley, Aaron M.; Steill, Jeffrey D.; Behrens, Richard; Kay, Jeffrey J.

    2015-04-01

    This report summarizes initial studies into the chemical basis of the thermal insensitivity of INMX-104. The work follows upon similar efforts investigating this behavior for another DNAN-based insensitive explosive, IMX-101. The experiments described demonstrate a clear similarity between the ingredient interactions that were shown to lead to the thermal insensitivity observed in IMX-101 and those that are active in IMX-104 at elevated temperatures. Specifically, the onset of decomposition of RDX is shifted to a lower temperature based on the interaction of the RDX with liquid DNAN. This early onset of decomposition dissipates some stored energy that is then unavailable for a delayed, more violent release.

  13. A coke oven model including thermal decomposition kinetics of tar

    SciTech Connect (OSTI)

    Munekane, Fuminori; Yamaguchi, Yukio; Tanioka, Seiichi

    1997-12-31

    A new one-dimensional coke oven model has been developed for simulating the amount and the characteristics of by-products such as tar and gas as well as coke. This model consists of both heat transfer and chemical kinetics including thermal decomposition of coal and tar. The chemical kinetics constants are obtained by estimation based on the results of experiments conducted to investigate the thermal decomposition of both coal and tar. The calculation results using the new model are in good agreement with experimental ones.

  14. Iterative image-domain decomposition for dual-energy CT

    SciTech Connect (OSTI)

    Niu, Tianye; Dong, Xue; Petrongolo, Michael; Zhu, Lei

    2014-04-15

    Purpose: Dual energy CT (DECT) imaging plays an important role in advanced imaging applications due to its capability of material decomposition. Direct decomposition via matrix inversion suffers from significant degradation of image signal-to-noise ratios, which reduces clinical values of DECT. Existing denoising algorithms achieve suboptimal performance since they suppress image noise either before or after the decomposition and do not fully explore the noise statistical properties of the decomposition process. In this work, the authors propose an iterative image-domain decomposition method for noise suppression in DECT, using the full variance-covariance matrix of the decomposed images. Methods: The proposed algorithm is formulated in the form of least-square estimation with smoothness regularization. Based on the design principles of a best linear unbiased estimator, the authors include the inverse of the estimated variance-covariance matrix of the decomposed images as the penalty weight in the least-square term. The regularization term enforces the image smoothness by calculating the square sum of neighboring pixel value differences. To retain the boundary sharpness of the decomposed images, the authors detect the edges in the CT images before decomposition. These edge pixels have small weights in the calculation of the regularization term. Distinct from the existing denoising algorithms applied on the images before or after decomposition, the method has an iterative process for noise suppression, with decomposition performed in each iteration. The authors implement the proposed algorithm using a standard conjugate gradient algorithm. The method performance is evaluated using an evaluation phantom (Catphan600) and an anthropomorphic head phantom. The results are compared with those generated using direct matrix inversion with no noise suppression, a denoising method applied on the decomposed images, and an existing algorithm with similar formulation as the proposed method but with an edge-preserving regularization term. Results: On the Catphan phantom, the method maintains the same spatial resolution on the decomposed images as that of the CT images before decomposition (8 pairs/cm) while significantly reducing their noise standard deviation. Compared to that obtained by the direct matrix inversion, the noise standard deviation in the images decomposed by the proposed algorithm is reduced by over 98%. Without considering the noise correlation properties in the formulation, the denoising scheme degrades the spatial resolution to 6 pairs/cm for the same level of noise suppression. Compared to the edge-preserving algorithm, the method achieves better low-contrast detectability. A quantitative study is performed on the contrast-rod slice of Catphan phantom. The proposed method achieves lower electron density measurement error as compared to that by the direct matrix inversion, and significantly reduces the error variation by over 97%. On the head phantom, the method reduces the noise standard deviation of decomposed images by over 97% without blurring the sinus structures. Conclusions: The authors propose an iterative image-domain decomposition method for DECT. The method combines noise suppression and material decomposition into an iterative process and achieves both goals simultaneously. By exploring the full variance-covariance properties of the decomposed images and utilizing the edge predetection, the proposed algorithm shows superior performance on noise suppression with high image spatial resolution and low-contrast detectability.

  15. Effects of oxygen and catalyst on tetraphenylborate decomposition rate

    SciTech Connect (OSTI)

    Walker, D.D.

    1999-12-15

    Previous studies indicate that palladium catalyzes rapid decomposition of alkaline tetraphenylborate slurries. Oxygen inhibits the reaction at low temperature (25 C), presumably by preventing activation of the catalyst. The present study investigated oxygen's inhibiting effectiveness at higher temperature (45 C) and catalyst concentrations.

  16. Roaming radical pathways for the decomposition of alkanes.

    SciTech Connect (OSTI)

    Harding, L. B.; Klippenstein, S. J.

    2010-01-01

    CASPT2 calculations predict the existence of roaming radical pathways for the decomposition of propane, n-butane, isobutane and neopentane. The roaming radical paths lead to the formation of an alkane and an alkene instead of the expected radical products. The predicted barriers for the roaming radical paths lie {approx}1 kcal/mol below the corresponding radical asymptotes.

  17. INDDGO: Integrated Network Decomposition & Dynamic programming for Graph Optimization

    SciTech Connect (OSTI)

    Groer, Christopher S; Sullivan, Blair D; Weerapurage, Dinesh P

    2012-10-01

    It is well-known that dynamic programming algorithms can utilize tree decompositions to provide a way to solve some \\emph{NP}-hard problems on graphs where the complexity is polynomial in the number of nodes and edges in the graph, but exponential in the width of the underlying tree decomposition. However, there has been relatively little computational work done to determine the practical utility of such dynamic programming algorithms. We have developed software to construct tree decompositions using various heuristics and have created a fast, memory-efficient dynamic programming implementation for solving maximum weighted independent set. We describe our software and the algorithms we have implemented, focusing on memory saving techniques for the dynamic programming. We compare the running time and memory usage of our implementation with other techniques for solving maximum weighted independent set, including a commercial integer programming solver and a semi-definite programming solver. Our results indicate that it is possible to solve some instances where the underlying decomposition has width much larger than suggested by the literature. For certain types of problems, our dynamic programming code runs several times faster than these other methods.

  18. Method for improved decomposition of metal nitrate solutions

    DOE Patents [OSTI]

    Haas, P.A.; Stines, W.B.

    1981-01-21

    A method for co-conversion of aqueous solutions of one or more heavy metal nitrates is described, wherein thermal decomposition within a temperature range of about 300 to 800/sup 0/C is carried out in the presence of about 50 to 500% molar concentration of ammonium nitrate to total metal.

  19. Method for improved decomposition of metal nitrate solutions

    DOE Patents [OSTI]

    Haas, Paul A. (Knoxville, TN); Stines, William B. (Knoxville, TN)

    1983-10-11

    A method for co-conversion of aqueous solutions of one or more heavy metal nitrates wherein thermal decomposition within a temperature range of about 300.degree. to 800.degree. C. is carried out in the presence of about 50 to 500% molar concentration of ammonium nitrate to total metal.

  20. Limited-memory adaptive snapshot selection for proper orthogonal decomposition

    SciTech Connect (OSTI)

    Oxberry, Geoffrey M.; Kostova-Vassilevska, Tanya; Arrighi, Bill; Chand, Kyle

    2015-04-02

    Reduced order models are useful for accelerating simulations in many-query contexts, such as optimization, uncertainty quantification, and sensitivity analysis. However, offline training of reduced order models can have prohibitively expensive memory and floating-point operation costs in high-performance computing applications, where memory per core is limited. To overcome this limitation for proper orthogonal decomposition, we propose a novel adaptive selection method for snapshots in time that limits offline training costs by selecting snapshots according an error control mechanism similar to that found in adaptive time-stepping ordinary differential equation solvers. The error estimator used in this work is related to theory bounding the approximation error in time of proper orthogonal decomposition-based reduced order models, and memory usage is minimized by computing the singular value decomposition using a single-pass incremental algorithm. Results for a viscous Burgers test problem demonstrate convergence in the limit as the algorithm error tolerances go to zero; in this limit, the full order model is recovered to within discretization error. The resulting method can be used on supercomputers to generate proper orthogonal decomposition-based reduced order models, or as a subroutine within hyperreduction algorithms that require taking snapshots in time, or within greedy algorithms for sampling parameter space.

  1. Quantitative and qualitative measures of decomposition: Is there a link?

    SciTech Connect (OSTI)

    Eaton, Robert, J.; Sanchez, Felipe, G.

    2009-03-01

    Decomposition rates of loblolly pine coarse woody debris (CWD) were determined by mass loss and wood density changes for trees that differed in source of mortality (natural, girdle-poison, and felling). Specifically, three treatments were examined: (1) control (CON): natural mortality; (2) CD: 5-fold increase in CWD compared with the CON; and (3) CS: 12-fold increase in snags compared with the CON. The additional CWD in the CD treatment plots and the additional snags in the CS plots were achieved by felling (for the CD plots) or girdling followed by herbicide injection (for the CS plots) select trees in these plots. Consequently,mortality on the CD plots is due to natural causes and felling. Likewise, mortality on the CS plots is due to natural causes and girdle-poison. In each treatment plot, mortality due to natural causes was inventoried since 1997, whereas mortality due to girdle-poison and felling were inventoried since 2001. No significant difference was detected between the rates of decomposition for the CWD on these treatment plots, indicating that source of the tree mortality did not influence rates of decomposition once the tree fell. These experimental measures of decomposition were compared with two decay classification systems (three- and five-unit classifications) to determine linkages. Changes in wood density did not correlate to any decay classification, whereas mass loss had a weak correlation with decay class. However, the large degree of variation limits the utility of decay classification systems in estimating mass loss.

  2. Optical ranked-order filtering using threshold decomposition

    DOE Patents [OSTI]

    Allebach, J.P.; Ochoa, E.; Sweeney, D.W.

    1987-10-09

    A hybrid optical/electronic system performs median filtering and related ranked-order operations using threshold decomposition to encode the image. Threshold decomposition transforms the nonlinear neighborhood ranking operation into a linear space-invariant filtering step followed by a point-to-point threshold comparison step. Spatial multiplexing allows parallel processing of all the threshold components as well as recombination by a second linear, space-invariant filtering step. An incoherent optical correlation system performs the linear filtering, using a magneto-optic spatial light modulator as the input device and a computer-generated hologram in the filter plane. Thresholding is done electronically. By adjusting the value of the threshold, the same architecture is used to perform median, minimum, and maximum filtering of images. A totally optical system is also disclosed. 3 figs.

  3. Optical ranked-order filtering using threshold decomposition

    DOE Patents [OSTI]

    Allebach, Jan P. (West Lafayette, IN); Ochoa, Ellen (Pleasanton, CA); Sweeney, Donald W. (Alamo, CA)

    1990-01-01

    A hybrid optical/electronic system performs median filtering and related ranked-order operations using threshold decomposition to encode the image. Threshold decomposition transforms the nonlinear neighborhood ranking operation into a linear space-invariant filtering step followed by a point-to-point threshold comparison step. Spatial multiplexing allows parallel processing of all the threshold components as well as recombination by a second linear, space-invariant filtering step. An incoherent optical correlation system performs the linear filtering, using a magneto-optic spatial light modulator as the input device and a computer-generated hologram in the filter plane. Thresholding is done electronically. By adjusting the value of the threshold, the same architecture is used to perform median, minimum, and maximum filtering of images. A totally optical system is also disclosed.

  4. Patched bimetallic surfaces are active catalysts for ammonia decomposition

    SciTech Connect (OSTI)

    Guo, Wei; Vlachos, Dionisios G.

    2015-10-07

    In this study, ammonia decomposition is often used as an archetypical reaction for predicting new catalytic materials and understanding the very reason of why some reactions are sensitive on material’s structure. Core–shell or surface-segregated bimetallic nanoparticles expose outstanding activity for many heterogeneously catalysed reactions but the reasons remain elusive owing to the difficulties in experimentally characterizing active sites. Here by performing multiscale simulations in ammonia decomposition on various nickel loadings on platinum (111), we show that the very high activity of core–shell structures requires patches of the guest metal to create and sustain dual active sites: nickel terraces catalyse N-H bond breaking and nickel edge sites drive atomic nitrogen association. The structure sensitivity on these active catalysts depends profoundly on reaction conditions due to kinetically competing relevant elementary reaction steps. We expose a remarkable difference in active sites between transient and steady-state studies and provide insights into optimal material design.

  5. Computational studies of polysiloxanes : oxidation potentials and decomposition reactions.

    SciTech Connect (OSTI)

    Assary, R. S.; Curtiss, L. A.; Redfern, P. C.; Zhang, Z.; Amine, K.

    2011-06-23

    Silicon-containing solvents have tremendous potential for application as electrolytes for electrical energy storage devices such as lithium-ion (air) batteries and supercapacitors. Quantum chemical methods were employed to investigate trends in oxidation potentials and decomposition reactions of a series of polysiloxanes. Various electron-donating and -withdrawing substituents can be used to tune the oxidation potential in shorter chain siloxanes but not in longer ones. Decomposition reactions of siloxanes in their oxidized states were investigated and compared against their carbon analogues. These studies suggest that the Si-O group provides added stability for siloxanes over their carbon analogues. Computational studies have also been performed for various disiloxanes and siloxanes with spacer groups to understand their thermochemical stability and oxidation potentials.

  6. Thermal decomposition of silane to form hydrogenated amorphous Si film

    DOE Patents [OSTI]

    Strongin, Myron; Ghosh, Arup K.; Wiesmann, Harold J.; Rock, Edward B.; Lutz, III, Harry A.

    1980-01-01

    This invention relates to hydrogenated amorphous silicon produced by thermally decomposing silano (SiH.sub.4) or other gases comprising H and Si, at elevated temperatures of about 1700.degree.-2300.degree. C., and preferably in a vacuum of about 10.sup.-8 to 10.sup.-4 torr, to form a gaseous mixture of atomic hydrogen and atomic silicon, and depositing said gaseous mixture onto a substrate outside said source of thermal decomposition to form hydrogenated amorphous silicon.

  7. Some studies on anaerobic decomposition of leucaena leucocephala leaves

    SciTech Connect (OSTI)

    Torane, J.V.; Lokhande, C.D.; Pawar, S.H. )

    1990-01-01

    Batch type anaerobic decomposition process in leucaena leucocephala plant material (leaves) has been carried out under mesophilic conditions (below 35{degrees}C). The results of studies involving variations in pH, conductivity, temperature, and optical density of digester slurry for four weeks are reported. The gas production rate was also studied which reveals that the use of leucaena leucocephala for biogas production will be helpful.

  8. Incremental k-core decomposition: Algorithms and evaluation

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

    Sariyuce, Ahmet Erdem; Gedik, Bugra; Jacques-SIlva, Gabriela; Wu, Kun -Lung; Catalyurek, Umit V.

    2016-02-15

    A k-core of a graph is a maximal connected subgraph in which every vertex is connected to at least k vertices in the subgraph. k-core decomposition is often used in large-scale network analysis, such as community detection, protein function prediction, visualization, and solving NP-hard problems on real networks efficiently, like maximal clique finding. In many real-world applications, networks change over time. As a result, it is essential to develop efficient incremental algorithms for dynamic graph data. In this paper, we propose a suite of incremental k-core decomposition algorithms for dynamic graph data. These algorithms locate a small subgraph that ismore » guaranteed to contain the list of vertices whose maximum k-core values have changed and efficiently process this subgraph to update the k-core decomposition. We present incremental algorithms for both insertion and deletion operations, and propose auxiliary vertex state maintenance techniques that can further accelerate these operations. Our results show a significant reduction in runtime compared to non-incremental alternatives. We illustrate the efficiency of our algorithms on different types of real and synthetic graphs, at varying scales. Furthermore, for a graph of 16 million vertices, we observe relative throughputs reaching a million times, relative to the non-incremental algorithms.« less

  9. Evaluation of microporous carbon filters as catalysts for ozone decomposition

    SciTech Connect (OSTI)

    Whinnery, L.; Coutts, D.; Shen, C.; Adams, R. [Sandia National Labs., Livermore, CA (United States); Quintana, C.; Showalter, S. [Sandia National Labs., Albuquerque, NM (United States)

    1994-12-31

    Ozone is produced in small quantities in photocopiers and laser printers in the workplace and large quantities in industrial waste water treatment facilities. Carbon filters are commonly used to decompose this unwanted ozone. The three most important factors in producing a filter for this purpose are flow properties, efficiency, and cost. Most ozone decomposition applications require very low back-pressure at modest flow rates. The tradeoff between the number of pores and the size of the pores will be discussed. Typical unfiltered emissions in the workplace are approximately 1 ppm. The maximum permissible exposure limit, PEL, for worker exposure to ozone is 0.1 ppm over 8 hours. Several methods have been examined to increase the efficiency of ozone decomposition. Carbon surfaces were modified with catalysts, the surface activated, and the surface area was increased, in attempts to decompose ozone more effectively. Methods to reduce both the processing and raw material costs were investigated. Several sources of microporous carbon were investigated as ozone decomposition catalysts. Cheaper processing routes including macropore templating, faster drying and extracting methods were also studied.

  10. Roaming radical kinetics in the decomposition of acetaldehyde.

    SciTech Connect (OSTI)

    Harding, L. B.; Georgievskii, Y.; Klippenstein, S. J.; Chemical Sciences and Engineering Division

    2010-01-01

    A novel theoretical framework for predicting the branching between roaming and bond fission channels in molecular dissociations is described and applied to the decomposition of acetaldehyde. This reduced dimensional trajectory (RDT) approach, which is motivated by the long-range nature of the roaming, bond fission, and abstraction dynamical bottlenecks, involves the propagation of rigid-body trajectories on an analytic potential energy surface. The analytic potential is obtained from fits to large-scale multireference ab initio electronic structure calculations. The final potential includes one-dimensional corrections from higher-level electronic structure calculations and for the effect of conserved mode variations along both the addition and abstraction paths. The corrections along the abstraction path play a significant role in the predicted branching. Master equation simulations are used to transform the microcanonical branching ratios obtained from the RDT simulations to the temperature- and pressure-dependent branching ratios observed in thermal decomposition experiments. For completeness, a transition-state theory treatment of the contributions of the tight transition states for the molecular channels is included in the theoretical analyses. The theoretically predicted branching between molecules and radicals in the thermal decomposition of acetaldehyde is in reasonable agreement with the corresponding shock tube measurement described in the companion paper. The prediction for the ratio of the tight to roaming contributions to the molecular channel also agrees well with results extracted from recent experimental and experimental/theoretical photodissociation studies.

  11. Volume Decomposition and Feature Recognition for Hexahedral Mesh Generation

    SciTech Connect (OSTI)

    GADH,RAJIT; LU,YONG; TAUTGES,TIMOTHY J.

    1999-09-27

    Considerable progress has been made on automatic hexahedral mesh generation in recent years. Several automatic meshing algorithms have proven to be very reliable on certain classes of geometry. While it is always worth pursuing general algorithms viable on more general geometry, a combination of the well-established algorithms is ready to take on classes of complicated geometry. By partitioning the entire geometry into meshable pieces matched with appropriate meshing algorithm the original geometry becomes meshable and may achieve better mesh quality. Each meshable portion is recognized as a meshing feature. This paper, which is a part of the feature based meshing methodology, presents the work on shape recognition and volume decomposition to automatically decompose a CAD model into meshable volumes. There are four phases in this approach: (1) Feature Determination to extinct decomposition features, (2) Cutting Surfaces Generation to form the ''tailored'' cutting surfaces, (3) Body Decomposition to get the imprinted volumes; and (4) Meshing Algorithm Assignment to match volumes decomposed with appropriate meshing algorithms. The feature determination procedure is based on the CLoop feature recognition algorithm that is extended to be more general. Results are demonstrated over several parts with complicated topology and geometry.

  12. Geochemical drivers of organic matter decomposition in Arctic tundra soils

    SciTech Connect (OSTI)

    Herndon, Elizabeth M.; Yang, Ziming; Graham, David E.; Wullschleger, Stan D.; Gu, Baohua; Liang, Liyuan; Bargar, John; Janot, Noemie; Regier, Tom Z.

    2015-12-07

    Climate change is warming tundra ecosystems in the Arctic, resulting in the decomposition of previously-frozen soil organic matter (SOM) and release of carbon (C) to the atmosphere; however, the processes that control SOM decomposition and C emissions remain highly uncertain. In this study, we evaluate geochemical factors that influence anaerobic production of carbon dioxide (CO2) and methane (CH4) in the active layers of four ice-wedge polygons. Surface and soil pore waters were collected during the annual thaw season over a two-year period in an area containing waterlogged, low-centered polygons and well-drained, high-centered polygons. We report spatial and seasonal patterns of dissolved gases in relation to the geochemical properties of Fe and organic C as determined using spectroscopic and chromatographic techniques. Iron was present as Fe(II) in soil solution near the permafrost boundary but enriched as Fe(III) in the middle of the active layer, similar to dissolved aromatic-C and organic acids. Dissolved CH4 increased relative to dissolved CO2 with depth and varied with soil moisture in the middle of the active layer in patterns that were positively correlated with the proportion of dissolved Fe(III) in transitional and low-centered polygon soils but negatively correlated in the drier flat- and high-centered polygons. These results suggest that microbial-mediated Fe oxidation and reduction influence respiration/fermentation of SOM and production of substrates (e.g., low-molecular-weight organic acids) for methanogenesis. As a result, we infer that geochemical differences induced by water saturation dictate microbial products of SOM decomposition, and Fe geochemistry is an important factor regulating methanogenesis in anoxic tundra soils.

  13. Geochemical drivers of organic matter decomposition in Arctic tundra soils

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

    Herndon, Elizabeth M.; Yang, Ziming; Graham, David E.; Wullschleger, Stan D.; Gu, Baohua; Liang, Liyuan; Bargar, John; Janot, Noemie; Regier, Tom Z.

    2015-12-07

    Climate change is warming tundra ecosystems in the Arctic, resulting in the decomposition of previously-frozen soil organic matter (SOM) and release of carbon (C) to the atmosphere; however, the processes that control SOM decomposition and C emissions remain highly uncertain. In this study, we evaluate geochemical factors that influence anaerobic production of carbon dioxide (CO2) and methane (CH4) in the active layers of four ice-wedge polygons. Surface and soil pore waters were collected during the annual thaw season over a two-year period in an area containing waterlogged, low-centered polygons and well-drained, high-centered polygons. We report spatial and seasonal patterns ofmore »dissolved gases in relation to the geochemical properties of Fe and organic C as determined using spectroscopic and chromatographic techniques. Iron was present as Fe(II) in soil solution near the permafrost boundary but enriched as Fe(III) in the middle of the active layer, similar to dissolved aromatic-C and organic acids. Dissolved CH4 increased relative to dissolved CO2 with depth and varied with soil moisture in the middle of the active layer in patterns that were positively correlated with the proportion of dissolved Fe(III) in transitional and low-centered polygon soils but negatively correlated in the drier flat- and high-centered polygons. These results suggest that microbial-mediated Fe oxidation and reduction influence respiration/fermentation of SOM and production of substrates (e.g., low-molecular-weight organic acids) for methanogenesis. As a result, we infer that geochemical differences induced by water saturation dictate microbial products of SOM decomposition, and Fe geochemistry is an important factor regulating methanogenesis in anoxic tundra soils.« less

  14. Signal evaluations using singular value decomposition for Thomson scattering diagnostics

    SciTech Connect (OSTI)

    Tojo, H., E-mail: tojo.hiroshi@jaea.go.jp; Yatsuka, E.; Hatae, T.; Itami, K. [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka 311-0193 (Japan); Yamada, I.; Yasuhara, R.; Funaba, H.; Hayashi, H. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan)

    2014-11-15

    This paper provides a novel method for evaluating signal intensities in incoherent Thomson scattering diagnostics. A double-pass Thomson scattering system, where a laser passes through the plasma twice, generates two scattering pulses from the plasma. Evaluations of the signal intensities in the spectrometer are sometimes difficult due to noise and stray light. We apply the singular value decomposition method to Thomson scattering data with strong noise components. Results show that the average accuracy of the measured electron temperature (T{sub e}) is superior to that of temperature obtained using a low-pass filter (<20 MHz) or without any filters.

  15. Active eutectoid decomposition in Zr-3 wt.% Fe

    SciTech Connect (OSTI)

    Kumar, L.; Ramanujan, R.V.; Tewari, R.; Mukhopadhyay, P.; Banerjee, S.

    1999-02-19

    In the work reported here, the microstructural features associated with the active eutectoid decomposition of a near eutectoid alloy (Zr-3 wt.%Fe) on {beta} quenching were examined. The effects of aging after {beta} quenching, and of furnace cooling from the {beta} phase field, on the microstructure of the alloy were also studied. The microstructural characterization was carried out using optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM). The room temperature mechanical properties corresponding to some of the microstructures were evaluated by mechanical testing.

  16. Cho decomposition of electrically charged one-half monopole

    SciTech Connect (OSTI)

    Ng, Ban-Loong; Teh, Rosy; Wong, Khai-Ming

    2014-03-05

    Recently we have carried out some work on the Cho decomposition of the electrically neutral, finite energy one-half monopole solution of the SU(2) Yang-Mills-Higgs field theory. In this paper, we performed the decomposition of the electrically charged solution using the same numerical procedure. The gauge potential of the one-half dyon solution is decomposed into Abelian and non-Abelian components. The semi-infinite string singularity in the gauge potential is a contribution of the Higgs field and hence topological in nature. The string singularity cannot be cancelled by the non-Abelian components of the gauge potential. However, the string singularity is integrable and the energy of the solution is finite. By decomposing the magnetic fields and covariant derivatives of the Higgs field into three isospin space directions, we are able to provide conclusive evidence that the constructed one-half dyon is certainly a non-BPS solution even in the limit of vanishing Higgs self-coupling constant and electric charge. Furthermore, we found that the time component of gauge function is parallel to the Higgs field in isospace only at large distances, elsewhere they are non-parallel.

  17. Patched bimetallic surfaces are active catalysts for ammonia decomposition

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

    Guo, Wei; Vlachos, Dionisios G.

    2015-10-07

    In this study, ammonia decomposition is often used as an archetypical reaction for predicting new catalytic materials and understanding the very reason of why some reactions are sensitive on material’s structure. Core–shell or surface-segregated bimetallic nanoparticles expose outstanding activity for many heterogeneously catalysed reactions but the reasons remain elusive owing to the difficulties in experimentally characterizing active sites. Here by performing multiscale simulations in ammonia decomposition on various nickel loadings on platinum (111), we show that the very high activity of core–shell structures requires patches of the guest metal to create and sustain dual active sites: nickel terraces catalyse N-Hmore » bond breaking and nickel edge sites drive atomic nitrogen association. The structure sensitivity on these active catalysts depends profoundly on reaction conditions due to kinetically competing relevant elementary reaction steps. We expose a remarkable difference in active sites between transient and steady-state studies and provide insights into optimal material design.« less

  18. Parallel Algorithms for Graph Optimization using Tree Decompositions

    SciTech Connect (OSTI)

    Sullivan, Blair D; Weerapurage, Dinesh P; Groer, Christopher S

    2012-06-01

    Although many $\\cal{NP}$-hard graph optimization problems can be solved in polynomial time on graphs of bounded tree-width, the adoption of these techniques into mainstream scientific computation has been limited due to the high memory requirements of the necessary dynamic programming tables and excessive runtimes of sequential implementations. This work addresses both challenges by proposing a set of new parallel algorithms for all steps of a tree decomposition-based approach to solve the maximum weighted independent set problem. A hybrid OpenMP/MPI implementation includes a highly scalable parallel dynamic programming algorithm leveraging the MADNESS task-based runtime, and computational results demonstrate scaling. This work enables a significant expansion of the scale of graphs on which exact solutions to maximum weighted independent set can be obtained, and forms a framework for solving additional graph optimization problems with similar techniques.

  19. Kinetics and mechanism of the thermal decomposition of dimethylzinc

    SciTech Connect (OSTI)

    Sokolovskii, A.E.; Baev, A.K.

    1985-05-01

    This paper studies the thermodecomposition of dimethylzinc in a vacuum in the temperature range 554.9-611.0 K and the concentration range 0.0027-0.0188 mole/liter. The investigations were conducted by the static method with a membrane wall manometer, an essential advantage of which is the possibility of the determination of the pressure in the reaction chamber with the complete absence of contact of the dimethylzinc with air and mercury. The results of the chromatographic study of the composition of the gas phase are presented. In the range of initial concentrations the content of the main decomposition products (methane, ethane, propane) scarcely changes, whereas at a concentration of 0.0027 mole/liter the yield of propane decreases somewhat.

  20. Hydroxylamine Nitrate Decomposition under Non-radiological Conditions

    SciTech Connect (OSTI)

    McFarlane, Joanna; Delmau, Laetitia Helene; DePaoli, David W.; Mattus, Catherine H.; Phelps, Clarice E.; Roach, Benjamin D.

    2015-07-01

    Hydroxylamine nitrate (HAN) is used to reduce Pu(IV) to Pu(III) in the separation of plutonium from uranium. HAN becomes unstable under certain conditions and has been known to explode, causing injury to humans including death. Hence, it is necessary to deactivate HAN once the reduction of plutonium is finished. This report reviews what is known about the chemistry of HAN and various methods to achieve a safe decomposition. However, there are areas where more information is needed to make a decision about the handling of HAN in reprocessing of nuclear fuel. Experiments have demonstrated a number of non-radiolytic ways to safely decompose HAN, including heating in HNO3, photolytic oxidation in the presence of H2O2, and the addition of a metal such as Fe(III) that will oxidize the HAN.

  1. Object detection with a multistatic array using singular value decomposition

    DOE Patents [OSTI]

    Hallquist, Aaron T.; Chambers, David H.

    2014-07-01

    A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across a surface and that travels down the surface. The detection system converts the return signals from a time domain to a frequency domain, resulting in frequency return signals. The detection system then performs a singular value decomposition for each frequency to identify singular values for each frequency. The detection system then detects the presence of a subsurface object based on a comparison of the identified singular values to expected singular values when no subsurface object is present.

  2. Palladium catalysts synthesized by atomic layer deposition for methanol decomposition.

    SciTech Connect (OSTI)

    Elam, J. W.; Feng, H.; Stair, P. C.; Libera, J. A.; Setthapun, W.; Northwestern Univ.

    2010-05-25

    Atomic layer deposition (ALD) palladium films were deposited at 200 C on various ALD metal oxide surfaces using sequential exposures to Pd(II) hexafluoroacetylacetonate (Pd(hfac)2) and formalin. In situ quartz crystal microbalance measurements as well as ex situ measurements performed on planar substrates revealed that the Pd growth begins with a relatively slow nucleation process and accelerates once an adequate amount of Pd has deposited on the surface. Furthermore, the Pd nucleation is faster on ALD ZnO surfaces compared to ALD Al2O3 surfaces. ALD was utilized to synthesize highly dispersed, uniform Pd nanoparticles (1 to 2 nm in diameter) on ALD ZnO and Al2O3 coated mesoporous silica gel, and the catalytic performances of these samples were compared in the methanol decomposition reaction. The ALD Pd-Al2O3 showed high activity and hydrogen selectivity at relatively low temperatures while the ALD Pd-ZnO showed very low activity as well as quick deactivation. In situ extended X-ray absorption fine structure (EXAFS) measurement revealed that the Pd supported on ZnO 'dissolves' into the substrate during the methanol decomposition reaction which accounts for the gradual disappearance of its catalytic activity. By applying one cycle of ALD Al2O3 on top of the Pd-ZnO catalyst, the activity was enhanced and the catalyst deactivation was mitigated. This Al2O3 overcoating method stabilizes the Pd-ZnO and effectively prevents the dissolution of Pd into the ZnO substrate.

  3. Breast tissue decomposition with spectral distortion correction: A postmortem study

    SciTech Connect (OSTI)

    Ding, Huanjun; Zhao, Bo; Baturin, Pavlo; Behroozi, Farnaz; Molloi, Sabee

    2014-10-15

    Purpose: To investigate the feasibility of an accurate measurement of water, lipid, and protein composition of breast tissue using a photon-counting spectral computed tomography (CT) with spectral distortion corrections. Methods: Thirty-eight postmortem breasts were imaged with a cadmium-zinc-telluride-based photon-counting spectral CT system at 100 kV. The energy-resolving capability of the photon-counting detector was used to separate photons into low and high energy bins with a splitting energy of 42 keV. The estimated mean glandular dose for each breast ranged from 1.8 to 2.2 mGy. Two spectral distortion correction techniques were implemented, respectively, on the raw images to correct the nonlinear detector response due to pulse pileup and charge-sharing artifacts. Dual energy decomposition was then used to characterize each breast in terms of water, lipid, and protein content. In the meantime, the breasts were chemically decomposed into their respective water, lipid, and protein components to provide a gold standard for comparison with dual energy decomposition results. Results: The accuracy of the tissue compositional measurement with spectral CT was determined by comparing to the reference standard from chemical analysis. The averaged root-mean-square error in percentage composition was reduced from 15.5% to 2.8% after spectral distortion corrections. Conclusions: The results indicate that spectral CT can be used to quantify the water, lipid, and protein content in breast tissue. The accuracy of the compositional analysis depends on the applied spectral distortion correction technique.

  4. Empirical and physics based mathematical models of uranium hydride decomposition kinetics with quantified uncertainties.

    SciTech Connect (OSTI)

    Salloum, Maher N.; Gharagozloo, Patricia E.

    2013-10-01

    Metal particle beds have recently become a major technique for hydrogen storage. In order to extract hydrogen from such beds, it is crucial to understand the decomposition kinetics of the metal hydride. We are interested in obtaining a a better understanding of the uranium hydride (UH3) decomposition kinetics. We first developed an empirical model by fitting data compiled from different experimental studies in the literature and quantified the uncertainty resulting from the scattered data. We found that the decomposition time range predicted by the obtained kinetics was in a good agreement with published experimental results. Secondly, we developed a physics based mathematical model to simulate the rate of hydrogen diffusion in a hydride particle during the decomposition. We used this model to simulate the decomposition of the particles for temperatures ranging from 300K to 1000K while propagating parametric uncertainty and evaluated the kinetics from the results. We compared the kinetics parameters derived from the empirical and physics based models and found that the uncertainty in the kinetics predicted by the physics based model covers the scattered experimental data. Finally, we used the physics-based kinetics parameters to simulate the effects of boundary resistances and powder morphological changes during decomposition in a continuum level model. We found that the species change within the bed occurring during the decomposition accelerates the hydrogen flow by increasing the bed permeability, while the pressure buildup and the thermal barrier forming at the wall significantly impede the hydrogen extraction.

  5. Theoretical rate coefficients for allyl + HO2 and allyloxy decomposition

    SciTech Connect (OSTI)

    Goldsmith, C. F.; Klippenstein, S. J.; Green, W. H.

    2011-01-01

    The kinetics of the allyl + HO{sub 2} bimolecular reaction, the thermal decomposition of C{sub 3}H{sub 5}OOH, and the unimolecular reactions of C{sub 3}H{sub 5}O are studied theoretically. High-level ab initio calculations of the C{sub 3}H{sub 5}OOH and C{sub 3}H{sub 5}O potential energy surfaces are coupled with RRKM master equation methods to compute the temperature- and pressure-dependence of the rate coefficients. Variable reaction coordinate transition state theory is used to characterize the barrierless transition states for the allyl + HO{sub 2} and C{sub 3}H{sub 5}O + OH reactions. The predicted rate coefficients for allyl + HO{sub 2} ? C{sub 3}H{sub 5}OOH ? products are in good agreement with experimental values. The calculations for allyl + HO{sub 2} ? C{sub 3}H{sub 6} + O{sub 2} underpredict the observed rate. The new rate coefficients suggest that the reaction of allyl + HO{sub 2} will promote chain-branching significantly more than previous models suggest.

  6. Asymmetric modes decomposition in an overmoded relativistic backward wave oscillator

    SciTech Connect (OSTI)

    Zhang, Dian; Zhang, Jun Zhong, Huihuang; Jin, Zhenxing; Ju, Jinchuan

    2014-09-15

    Most of the investigated overmoded relativistic backward wave oscillators (RBWOs) are azimuthally symmetric; thus, they are designed through two dimensional (2-D) particle-in-cell (PIC) simulations. However, 2-D PIC simulations cannot reveal the effect of asymmetric modes on beam-wave interaction. In order to investigate whether asymmetric mode competition needs to be considered in the design of overmoded RBWOs, a numerical method of determining the composition of both symmetric and asymmetric modes in three dimensional (3-D) PIC simulations is introduced in this paper. The 2-D and 3-D PIC simulation results of an X-band overmoded RBWO are analyzed. Our analysis indicates that the 2-D and 3-D PIC simulation results of our device are quite different due to asymmetric mode competition. In fact, asymmetric surface waves, especially EH{sub 11} mode, can lead to serious mode competition when electron beam propagates near the surface of slow wave structures (SWSs). Therefore, additional method of suppressing asymmetric mode competition, such as adjusting the reflections at both ends of SWSs to decrease the Q-factor of asymmetric modes, needs to be utilized in the design of overmoded RBWOs. Besides, 3-D PIC simulation and modes decomposition are essential for designing overmoded RBWOs.

  7. Radiation-Induced Decomposition of PETN and TATB under Extreme Conditions

    SciTech Connect (OSTI)

    Giefers, Hubertus; Pravica, Michael

    2008-11-03

    We conducted a series of experiments investigating decomposition of secondary explosives PETN and TATB at varying static pressures and temperatures using synchrotron radiation. As seen in our earlier work, the decomposition rate of TATB at ambient temperature slows systematically with increasing pressure up to at least 26 GPa but varies little with pressure in PETN at ambient temperature up to 15.7 GPa, yielding important information pertaining to the activation complex volume in both cases. We also investigated the radiation-induced decomposition rate as a function of temperature at ambient pressure and 26 GPa for TATB up to 403 K, observing that the decomposition rate increases with increasing temperature as expected. The activation energy for the TATB reaction at ambient temperature was experimentally determined to be 16 {+-} 3 kJ/mol.

  8. Mass-radius relations and core-envelope decompositions of super...

    Office of Scientific and Technical Information (OSTI)

    We perform this decomposition for both ''Earth-like'' rock-iron cores and pure ice cores, and find that the necessary gaseous envelope masses for this important sub-class of ...

  9. TU-F-18A-02: Iterative Image-Domain Decomposition for Dual-Energy CT

    SciTech Connect (OSTI)

    Niu, T; Dong, X; Petrongolo, M; Zhu, L

    2014-06-15

    Purpose: Dual energy CT (DECT) imaging plays an important role in advanced imaging applications due to its material decomposition capability. Direct decomposition via matrix inversion suffers from significant degradation of image signal-to-noise ratios, which reduces clinical value. Existing de-noising algorithms achieve suboptimal performance since they suppress image noise either before or after the decomposition and do not fully explore the noise statistical properties of the decomposition process. We propose an iterative image-domain decomposition method for noise suppression in DECT, using the full variance-covariance matrix of the decomposed images. Methods: The proposed algorithm is formulated in the form of least-square estimation with smoothness regularization. It includes the inverse of the estimated variance-covariance matrix of the decomposed images as the penalty weight in the least-square term. Performance is evaluated using an evaluation phantom (Catphan 600) and an anthropomorphic head phantom. Results are compared to those generated using direct matrix inversion with no noise suppression, a de-noising method applied on the decomposed images, and an existing algorithm with similar formulation but with an edge-preserving regularization term. Results: On the Catphan phantom, our method retains the same spatial resolution as the CT images before decomposition while reducing the noise standard deviation of decomposed images by over 98%. The other methods either degrade spatial resolution or achieve less low-contrast detectability. Also, our method yields lower electron density measurement error than direct matrix inversion and reduces error variation by over 97%. On the head phantom, it reduces the noise standard deviation of decomposed images by over 97% without blurring the sinus structures. Conclusion: We propose an iterative image-domain decomposition method for DECT. The method combines noise suppression and material decomposition into an iterative process and achieves both goals simultaneously. The proposed algorithm shows superior performance on noise suppression with high image spatial resolution and low-contrast detectability. This work is supported by a Varian MRA grant.

  10. Decomposition of calcium sulfate: a review of the literature. [62 refs]

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

    (Technical Report) | SciTech Connect Decomposition of calcium sulfate: a review of the literature. [62 refs] Citation Details In-Document Search Title: Decomposition of calcium sulfate: a review of the literature. [62 refs] × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in

  11. Examination of phase transformations and decomposition chemistry in thermally aged thin-film explosives

    SciTech Connect (OSTI)

    Erickson, K.L.; Trott, W.M.; Renlund, A.M.

    1993-09-01

    To develop predictive models for the response of weapon systems to abnormal thermal environments, such as cookoff, an improved understanding of temperature-dependent thermophysical phenomena (such as phase transformations) and decomposition chemistry in totally confined explosive samples is needed. It is particularly important to examine the effects of maintaining-intimate contact between the decomposition products and the remaining condensed-phase explosive during slow reaction at elevated temperatures since confinement of the decomposition products may significantly affect thermophysical phenomena and decomposition reaction rates. The purpose of this work has been to examine experimentally the effects on condensed-phase chemistry which result when decomposition products remain in intimate contact with the reacting explosive during isothermal aging experiments at temperatures below those of the DTA exotherm for the explosive. To provide confinement, minimize vapor space, and permit condensed-phase chemical analysis, experiments were done using thin-film samples of the explosive, which were pressed and sealed between two infrared-transmitting windows, so that condensed-phase chemistry could be monitored using infrared spectroscopy. Experiments were done with NC, HMX, HMX-NC composite, and RDX samples. Results from the experiments with NC showed that for some decomposition mechanisms, the reaction rates for confined samples compared favorably with published reaction rates from unconfined samples. However, the results also demonstrated that for other mechanisms, the reaction rates were significantly affected by confinement of the decomposition products. The experiments with HMX and RDX indicated that some decomposition occurred at temperatures well below the temperatures of the respective DTA exotherms, and the experiments with HMX-NC composite samples showed some interaction between NC and HMX at temperatures as low as 150{degrees}C.

  12. Theoretical study of isomerization and decomposition of propenal

    SciTech Connect (OSTI)

    Chin, Chih-Hao; Lee, Shih-Huang

    2011-01-28

    We investigated the dynamics of isomerization and multi-channel dissociation of propenal (CH{sub 2}CHCHO), methyl ketene (CH{sub 3}CHCO), hydroxyl propadiene (CH{sub 2}CH{sub 2}CHOH), and hydroxyl cyclopropene (cyclic-C{sub 3}H{sub 3}-OH) in the ground potential-energy surface using quantum-chemical calculations. Optimized structures and vibrational frequencies of molecular species were computed with method B3LYP/6-311G(d,p). Total energies of molecules at optimized structures were computed at the CCSD(T)/6-311+G(3df,2p) level of theory. We established the potential-energy surface for decomposition to CH{sub 2}CHCO + H, CH{sub 2}CH + HCO, CH{sub 2}CH{sub 2}/CH{sub 3}CH + CO, CHCH/CH{sub 2}C + H{sub 2}CO, CHCCHO/CH{sub 2}CCO + H{sub 2}, CHCH + CO + H{sub 2}, CH{sub 3}+ HCCO, CH{sub 2}CCH + OH, and CH{sub 2}CC/cyclic-C{sub 3}H{sub 2}+ H{sub 2}O. Microcanonical rate coefficients of various reactions of trans-propenal with internal energies 148 and 182 kcal mol{sup -1} were calculated using Rice-Ramsperger-Kassel-Marcus and Variational transition state theories. Product branching ratios were derivable using numerical integration of kinetic master equations and the steady-state approximation. The concerted three-body dissociation of trans-propenal to fragments C{sub 2}H{sub 2}+ CO + H{sub 2} is the prevailing channel in present calculations. In contrast, C{sub 3}H{sub 3}O + H, C{sub 2}H{sub 3}+ HCO and C{sub 2}H{sub 4}+ CO were identified as major channels in the photolysis of trans-propenal. The discrepancy between calculations and experiments in product branching ratios indicates that the three major photodissociation channels occur mainly on an excited potential-energy surface whereas the other channels occur mainly on the ground potential-energy surface. This work provides profound insight in the mechanisms of isomerization and multichannel dissociation of the system C{sub 3}H{sub 4}O.

  13. Ab Initio Kinetics and Thermal Decomposition Mechanism of Mononitrobiuret and 1,5- Dinitrobiuret

    SciTech Connect (OSTI)

    Sun, Hongyan; Vaghjiani, Ghanshyam G.

    2015-05-26

    Mononitrobiuret (MNB) and 1,5-dinitrobiuret (DNB) are tetrazole-free, nitrogen-rich, energetic compounds. For the first time, a comprehensive ab initio kinetics study on the thermal decomposition mechanisms of MNB and DNB is reported here. In particular, the intramolecular interactions of amine H-atom with electronegative nitro O-atom and carbonyl O-atom have been analyzed for biuret, MNB, and DNB at the M06-2X/aug-cc-pVTZ level of theory. The results show that the MNB and DNB molecules are stabilized through six-member-ring moieties via intramolecular H-bonding with interatomic distances between 1.8 and 2.0 , due to electrostatic as well as polarization and dispersion interactions. Furthermore, it was found that the stable molecules in the solid state have the smallest dipole moment amongst all the conformers in the nitrobiuret series of compounds, thus revealing a simple way for evaluating reactivity of fuel conformers. The potential energy surface for thermal decomposition of MNB was characterized by spin restricted coupled cluster theory at the RCCSD(T)/cc-pV? Z//M06-2X/aug-cc-pVTZ level. It was found that the thermal decomposition of MNB is initiated by the elimination of HNCO and HNN(O)OH intermediates. Intramolecular transfer of a H-atom, respectively, from the terminal NH2 group to the adjacent carbonyl O-atom via a six-member-ring transition state eliminates HNCO with an energy barrier of 35 kcal/mol and from the central NH group to the adjacent nitro O-atom eliminates HNN(O)OH with an energy barrier of 34 kcal/mol. Elimination of HNN(O)OH is also the primary process involved in the thermal decomposition of DNB, which processes C2v symmetry. The rate coefficients for the primary decomposition channels for MNB and DNB were quantified as functions of temperature and pressure. In addition, the thermal decomposition of HNN(O)OH was analyzed via RiceRamspergerKasselMarcus/multi-well master equation simulations, the results of which reveal the formation of (NO2 + H2O) to be the major decomposition path. Furthermore, we provide fundamental interpretations for the experimental results of Klaptke et al. [Combust. Flame 139, 358366 (2004)] regarding the thermal stability of MNB and DNB, and their decomposition products. Notably, a fundamental understanding of fuel stability, decomposition mechanism, and key reactions leading to ignition is essential in the design and manipulation of molecular systems for the development of new energetic materials for advanced propulsion applications.

  14. Ab initio kinetics and thermal decomposition mechanism of mononitrobiuret and 1,5-dinitrobiuret

    SciTech Connect (OSTI)

    Sun, Hongyan E-mail: ghanshyam.vaghjiani@us.af.mil; Vaghjiani, Ghanshyam L. E-mail: ghanshyam.vaghjiani@us.af.mil

    2015-05-28

    Mononitrobiuret (MNB) and 1,5-dinitrobiuret (DNB) are tetrazole-free, nitrogen-rich, energetic compounds. For the first time, a comprehensive ab initio kinetics study on the thermal decomposition mechanisms of MNB and DNB is reported here. In particular, the intramolecular interactions of amine H-atom with electronegative nitro O-atom and carbonyl O-atom have been analyzed for biuret, MNB, and DNB at the M06-2X/aug-cc-pVTZ level of theory. The results show that the MNB and DNB molecules are stabilized through six-member-ring moieties via intramolecular H-bonding with interatomic distances between 1.8 and 2.0 , due to electrostatic as well as polarization and dispersion interactions. Furthermore, it was found that the stable molecules in the solid state have the smallest dipole moment amongst all the conformers in the nitrobiuret series of compounds, thus revealing a simple way for evaluating reactivity of fuel conformers. The potential energy surface for thermal decomposition of MNB was characterized by spin restricted coupled cluster theory at the RCCSD(T)/cc-pV? Z//M06-2X/aug-cc-pVTZ level. It was found that the thermal decomposition of MNB is initiated by the elimination of HNCO and HNN(O)OH intermediates. Intramolecular transfer of a H-atom, respectively, from the terminal NH{sub 2} group to the adjacent carbonyl O-atom via a six-member-ring transition state eliminates HNCO with an energy barrier of 35 kcal/mol and from the central NH group to the adjacent nitro O-atom eliminates HNN(O)OH with an energy barrier of 34 kcal/mol. Elimination of HNN(O)OH is also the primary process involved in the thermal decomposition of DNB, which processes C{sub 2v} symmetry. The rate coefficients for the primary decomposition channels for MNB and DNB were quantified as functions of temperature and pressure. In addition, the thermal decomposition of HNN(O)OH was analyzed via RiceRamspergerKasselMarcus/multi-well master equation simulations, the results of which reveal the formation of (NO{sub 2} + H{sub 2}O) to be the major decomposition path. Furthermore, we provide fundamental interpretations for the experimental results of Klaptke et al. [Combust. Flame 139, 358366 (2004)] regarding the thermal stability of MNB and DNB, and their decomposition products. Notably, a fundamental understanding of fuel stability, decomposition mechanism, and key reactions leading to ignition is essential in the design and manipulation of molecular systems for the development of new energetic materials for advanced propulsion applications.

  15. Lattice QCD with Domain Decomposition on Intel Xeon Phi Co-Processors

    SciTech Connect (OSTI)

    Heybrock, Simon; Joo, Balint; Kalamkar, Dhiraj D.; Smelyanskiy, Mikhail; Vaidyanathan, Karthikeyan; Wettig, Tilo; Dubey, Pradeep

    2014-12-01

    The gap between the cost of moving data and the cost of computing continues to grow, making it ever harder to design iterative solvers on extreme-scale architectures. This problem can be alleviated by alternative algorithms that reduce the amount of data movement. We investigate this in the context of Lattice Quantum Chromodynamics and implement such an alternative solver algorithm, based on domain decomposition, on Intel Xeon Phi co-processor (KNC) clusters. We demonstrate close-to-linear on-chip scaling to all 60 cores of the KNC. With a mix of single- and half-precision the domain-decomposition method sustains 400-500 Gflop/s per chip. Compared to an optimized KNC implementation of a standard solver [1], our full multi-node domain-decomposition solver strong-scales to more nodes and reduces the time-to-solution by a factor of 5.

  16. Implementation of the singular-value decomposition on the Connection Machine CM-2

    SciTech Connect (OSTI)

    Chu, N.A.

    1991-04-11

    In modern digital signal processing, the singular value decomposition is increasingly recognized as an important mathematical tool. The true measure of usefulness of such a tool is very much dependent on the ability to compute it at supercomputer throughput rates. This report describes an implementation of the singular value decomposition (SVD) on the Connection Machine CM-2 using parallel Fortran. The algorithm is based on Hestenes's, which is a Jacobi iteration in which pairs of rows are rotated to become orthogonal. The Fortran implementation of this algorithm on a full CM-2 is comparable in execution speed to the Linpack implementation on a Convex C220 processor.

  17. Mass-radius relations and core-envelope decompositions of super-Earths and

    Office of Scientific and Technical Information (OSTI)

    sub-Neptunes (Journal Article) | SciTech Connect Mass-radius relations and core-envelope decompositions of super-Earths and sub-Neptunes Citation Details In-Document Search Title: Mass-radius relations and core-envelope decompositions of super-Earths and sub-Neptunes Many exoplanets have been discovered with radii of 1-4 R {sub ⊕}, between that of Earth and Neptune. A number of these are known to have densities consistent with solid compositions, while others are 'sub-Neptunes' likely to

  18. Oxidative decomposition of methanol on subnanometer palladium clusters : the effect of catalyst size and support composition.

    SciTech Connect (OSTI)

    Lee, S.; Lee, B.; Mehmood, F.; Seifert, S.; Libera, J. A.; Elam, J. W.; Greeley, J.; Zapol, P.; Curtiss, L. A.; Pellin, M. J.; Stair, P. C.; Winans, R. E; Vajda, S.; Northwestern Univ.

    2010-06-17

    Size and support effects in the oxidative decomposition of methanol on amorphous alumina supported subnanometer palladium clusters were studied under realistic reaction conditions of pressure and temperature. The smaller Pd{sub 8-12} clusters were found to promote the decomposition channel to CO and hydrogen, however with mediocre activity due to poisoning. The larger Pd{sub 15-18} clusters preferentially produce dimethyl ether and formaldehyde, without signs of posioning. A thin titania overcoat applied on the Pd{sub 15-18} improves the sintering-resistance of the catalyst. Accompanying density functional calculations confirm the posioning of small Pd clusters by CO.

  19. Oxidative Decomposition of Methanol on Subnanometer Palladium Clusters: The Effect of Catalyst Size and Support Composition

    SciTech Connect (OSTI)

    Lee, Sungsik; Lee, Byeongdu; Mehmood, Faisal; Seifert, Soenke; Libera, Joseph A.; Elam, J. W.; Greeley, Jeffrey P.; Zapol, Peter; Curtiss, Larry A.; Pellin, M. J.; Stair, Peter C.; Winans, R. E.; Vajda, S.

    2010-05-31

    Size and support effects in the oxidative decomposition of methanol on amorphous alumina supported subnanometer palladium clusters were studied under realistic reaction conditions of pressure and temperature. The smaller Pd8-12 clusters were found to promote the decomposition channel to CO and hydrogen, however with mediocre activity due to poisoning. The larger Pd15-18 clusters preferentially produce dimethyl ether and formaldehyde, without signs of posioning. A thin titania overcoat applied on the Pd15-18 improves the sintering-resistance of the catalyst. Accompanying density functional calculations confirm the posioning of small Pd clusters by CO.

  20. Decomposition of chlorinated ethylenes and ethanes in an electron beam generated plasma reactor

    SciTech Connect (OSTI)

    Vitale, S.A.

    1996-02-01

    An electron beam generated plasma reactor (EBGPR) is used to determine the plasma chemistry kinetics, energetics and decomposition pathways of six chlorinated ethylenes and ethanes: 1,1,1-trichloroethane, 1,1-dichloroethane, ethyl chloride, trichloroethylene, 1,1-dichloroethylene, and vinyl chloride. A traditional chemical kinetic and chemical engineering analysis of the data from the EBGPR is performed, and the following hypothesis was verified: The specific energy required for chlorinated VOC decomposition in the electron beam generated plasma reactor is determined by the electron attachment coefficient of the VOC and the susceptibility of the molecule to radical attack. The technology was demonstrated at the Hanford Reservation to remove VOCs from soils.

  1. Comparative Density Functional Study of Methanol Decomposition on Cu4 and Co4 Clusters

    SciTech Connect (OSTI)

    Mehmood, Faisal; Greeley, Jeffrey P.; Zapol, Peter; Curtiss, Larry A.

    2010-11-18

    A density functional theory study of the decomposition of methanol on Cu4 and Co4 clusters is presented. The reaction intermediates and activation barriers have been determined for reaction steps to form H2 and CO. For both clusters, methanol decomposition initiated by C-H and O-H bond breaking was investigated. In the case of a Cu4 cluster, methanol dehydrogenation through hydroxymethyl (CH2OH), hydroxymethylene (CHOH), formyl (CHO), and carbon monoxide (CO) is found to be slightly more favorable. For a Co4 cluster, the dehydrogenation pathway through methoxy (CH3O) and formaldehyde (CH2O) is slightly more favorable. Each of these pathways results in formation of CO and H2. The Co cluster pathway is very favorable thermodynamically and kinetically for dehydrogenation. However, since CO binds strongly, it is likely to poison methanol decomposition to H2 and CO at low temperatures. In contrast, for the Cu cluster, CO poisoning is not likely to be a problem since it does not bind strongly, but the dehydrogenation steps are not energetically favorable. Pathways involving C-O bond cleavage are even less energetically favorable. The results are compared to our previous study of methanol decomposition on Pd4 and Pd8 clusters. Finally, all reaction energy changes and transition state energies, including those for the Pd clusters, are related in a linear, Broensted-Evans-Polanyi plot.

  2. Hydrate decomposition conditions in the system hydrogen sulfide-methane, and propane

    SciTech Connect (OSTI)

    Schroeter, J.P.; Kobayashi, R.; Hildebrand, H.A.

    1982-12-01

    Experimental hydrate decomposition conditions are presented for 3 different H/sub 2/S-containing mixtures in the temperature region 0 C to 30 C. The 3 mixtures investigated were 4% H/sub 2/S, 7% propane, 89% methane; 12% H/sub 2/S, 7% propane, 81% methane; and 30% H/sub 2/S, 7% propane, 63% methane. Hydrate decomposition pressures and temperatures were obtained for each of these mixtures by observation of the pressure-temperature hysteresis curves associated with formation and decomposition of the hydrate crystals. A repeatable decomposition point was observed in every case, and this was identified as the hydrate point. The results for the 4% H/sub 2/S mixture were used to adjust parameters in a computer model based on the Parrish and Prausnitz statistical thermodynamics method, coupled with the BWRS equation of state. After the parameter adjustment, the computer model predicted the behavior of the 12% H/sub 2/S and the 30% H/sub 2/S mixtures to within 2 C. Experimental data for the 3 mixtures are given.

  3. Photogeneration of active formate decomposition catalysts to produce hydrogen from formate and water

    DOE Patents [OSTI]

    King, Jr., Allen D. (Athens, GA); King, Robert B. (Athens, GA); Sailers, III, Earl L. (Athens, GA)

    1983-02-08

    A process for producing hydrogen from formate and water by photogenerating an active formate decomposition catalyst from transition metal carbonyl precursor catalysts at relatively low temperatures and otherwise mild conditions is disclosed. Additionally, this process may be expanded to include the generation of formate from carbon monoxide and hydroxide such that the result is the water gas shift reaction.

  4. Decomposition of toluene in a steady-state atmospheric-pressure glow discharge

    SciTech Connect (OSTI)

    Trushkin, A. N.; Grushin, M. E.; Kochetov, I. V.; Trushkin, N. I.; Akishev, Yu. S.

    2013-02-15

    Results are presented from experimental studies of decomposition of toluene (C{sub 6}H{sub 5}CH{sub 3}) in a polluted air flow by means of a steady-state atmospheric pressure glow discharge at different water vapor contents in the working gas. The experimental results on the degree of C{sub 6}H{sub 5}CH{sub 3} removal are compared with the results of computer simulations conducted in the framework of the developed kinetic model of plasma chemical decomposition of toluene in the N{sub 2}: O{sub 2}: H{sub 2}O gas mixture. A substantial influence of the gas flow humidity on toluene decomposition in the atmospheric pressure glow discharge is demonstrated. The main mechanisms of the influence of humidity on C{sub 6}H{sub 5}CH{sub 3} decomposition are determined. The existence of two stages in the process of toluene removal, which differ in their duration and the intensity of plasma chemical decomposition of C{sub 6}H{sub 5}CH{sub 3} is established. Based on the results of computer simulations, the composition of the products of plasma chemical reactions at the output of the reactor is analyzed as a function of the specific energy deposition and gas flow humidity. The existence of a catalytic cycle in which hydroxyl radical OH acts a catalyst and which substantially accelerates the recombination of oxygen atoms and suppression of ozone generation when the plasma-forming gas contains water vapor is established.

  5. CPUF - a chemical-structure-based polyurethane foam decomposition and foam response model.

    SciTech Connect (OSTI)

    Fletcher, Thomas H. (Brigham Young University, Provo, UT); Thompson, Kyle Richard; Erickson, Kenneth L.; Dowding, Kevin J.; Clayton, Daniel (Brigham Young University, Provo, UT); Chu, Tze Yao; Hobbs, Michael L.; Borek, Theodore Thaddeus III

    2003-07-01

    A Chemical-structure-based PolyUrethane Foam (CPUF) decomposition model has been developed to predict the fire-induced response of rigid, closed-cell polyurethane foam-filled systems. The model, developed for the B-61 and W-80 fireset foam, is based on a cascade of bondbreaking reactions that produce CO2. Percolation theory is used to dynamically quantify polymer fragment populations of the thermally degrading foam. The partition between condensed-phase polymer fragments and gas-phase polymer fragments (i.e. vapor-liquid split) was determined using a vapor-liquid equilibrium model. The CPUF decomposition model was implemented into the finite element (FE) heat conduction codes COYOTE and CALORE, which support chemical kinetics and enclosure radiation. Elements were removed from the computational domain when the calculated solid mass fractions within the individual finite element decrease below a set criterion. Element removal, referred to as ?element death,? creates a radiation enclosure (assumed to be non-participating) as well as a decomposition front, which separates the condensed-phase encapsulant from the gas-filled enclosure. All of the chemistry parameters as well as thermophysical properties for the CPUF model were obtained from small-scale laboratory experiments. The CPUF model was evaluated by comparing predictions to measurements. The validation experiments included several thermogravimetric experiments at pressures ranging from ambient pressure to 30 bars. Larger, component-scale experiments were also used to validate the foam response model. The effects of heat flux, bulk density, orientation, embedded components, confinement and pressure were measured and compared to model predictions. Uncertainties in the model results were evaluated using a mean value approach. The measured mass loss in the TGA experiments and the measured location of the decomposition front were within the 95% prediction limit determined using the CPUF model for all of the experiments where the decomposition gases were vented sufficiently. The CPUF model results were not as good for the partially confined radiant heat experiments where the vent area was regulated to maintain pressure. Liquefaction and flow effects, which are not considered in the CPUF model, become important when the decomposition gases are confined.

  6. Kinetics of Methane Hydrate Decomposition Studied via in Situ Low Temperature X-ray Powder Diffraction

    SciTech Connect (OSTI)

    Everett, Susan M; Rawn, Claudia J; Keffer, David J.; Mull, Derek L; Payzant, E Andrew; Phelps, Tommy Joe

    2013-01-01

    Gas hydrates are known to have a slowed decomposition rate at ambient pressure and temperatures below the melting point of ice termed self-preservation or anomalous preservation. As hydrate exothermically decomposes, gas is released and water of the clathrate cages transforms into ice. Two regions of slowed decomposition for methane hydrate, 180 200 K and 230 260 K, were observed, and the kinetics were studied by in situ low temperature x-ray powder diffraction. The kinetic constants for ice formation from methane hydrate were determined by the Avrami model within each region and activation energies, Ea, were determined by the Arrhenius plot. Ea determined from the data for 180 200 K was 42 kJ/mol and for 230 260 K was 22 kJ/mol. The higher Ea in the colder temperature range was attributed to a difference in the microstructure of ice between the two regions.

  7. Controllable pneumatic generator based on the catalytic decomposition of hydrogen peroxide

    SciTech Connect (OSTI)

    Kim, Kyung-Rok; Kim, Kyung-Soo Kim, Soohyun

    2014-07-15

    This paper presents a novel compact and controllable pneumatic generator that uses hydrogen peroxide decomposition. A fuel micro-injector using a piston-pump mechanism is devised and tested to control the chemical decomposition rate. By controlling the injection rate, the feedback controller maintains the pressure of the gas reservoir at a desired pressure level. Thermodynamic analysis and experiments are performed to demonstrate the feasibility of the proposed pneumatic generator. Using a prototype of the pneumatic generator, it takes 6 s to reach 3.5 bars with a reservoir volume of 200 ml at the room temperature, which is sufficiently rapid and effective to maintain the repetitive lifting of a 1 kg mass.

  8. Spinodal Decomposition and Nucleation and Growth as a Means to Bulk

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

    Nanostructured Thermoelectrics: Enhanced Perfomance in Pb1-xSnxTe-PbS | Energy Frontier Research Centers Spinodal Decomposition and Nucleation and Growth as a Means to Bulk Nanostructured Thermoelectrics: Enhanced Perfomance in Pb1-xSnxTe-PbS Home Author: J. Androulakis, C. Uher, T. Hogan, M. G. Kanatzidis, et.al Year: 2007 Abstract: URL: Link to article - FTIR spectroscopy and Thermal Analysis labs Document: Download Document (PDF) - 6962.01kb

  9. A quasimechanism of melt acceleration in the thermal decomposition of crystalline organic solids

    SciTech Connect (OSTI)

    Henson, Bryan F

    2009-01-01

    It has been know for half a century that many crystalline organic solids undergo an acceleration in the rate of thermal decomposition as the melting temperature is approached. This acceleration terminates at the melting point, exhibiting an Arrhenius-like temperature dependence in the faster decomposition rate from the liquid phase. This observation has been modeled previously using various premelting behaviors based on e.g. freezing point depression induced by decomposition products or solvent impurities. These models do not, however, indicate a mechanism for liquid formation and acceleration which is an inherent function of the bulk thermodynamics of the molecule. Here we show that such an inherent thermodynamic mechanism for liquid formation exists in the form of the so-called quasi-liquid layer at the solid surface. We explore a kinetic mechanism which describes the acceleration of rate and is a function of the free energies of sublimation and vaporization. We construct a differential rate law from these thermodynamic free energies and a normalized progress variable. We further construct a reduced variable formulation of the model which is a simple function of the metastable liquid activity below the melting point, and show that it is applicable to the observed melt acceleration in several common organic crystalline solids. A component of the differential rate law, zero order in the progress variable, is shown to be proportional to the thickness of the quasiliquid layer predicted by a recent thermodynamic theory for this phenomenon. This work therefore serves not only to provide new insight into thermal decomposition in a broad class or organic crystalline solids, but also further validates the underlying thermodynamic nature of the phenomenon of liquid formation on the molecular surface at temperatures below the melting point.

  10. Pathways of anaerobic organic matter decomposition in tundra soils from Barrow, Alaska

    SciTech Connect (OSTI)

    Herndon, Elizabeth M.; Mann, Benjamin F.; Chowdhury, Taniya Roy; Wullschleger, Stan D.; Graham, David E.; Liang, Liyuan; Gu, Baohua; Yang, Ziming

    2015-11-23

    Arctic tundra soils store a large quantity of organic carbon that is susceptible to decomposition and release to the atmosphere as methane (CH4) and carbon dioxide (CO2) under a warming climate. Anaerobic processes that generate CH4 and CO2 remain unclear because previous studies have focused on aerobic decomposition pathways. To predict releases of CO2 and CH4 from tundra soils, it is necessary to identify pathways of soil organic matter decomposition under the anoxic conditions that are prevalent in Arctic ecosystems. Here molecular and spectroscopic techniques were used to monitor biological degradation of water-extractable organic carbon (WEOC) during anoxic incubation of tundra soils from a region of continuous permafrost in northern Alaska. Organic and mineral soils from the tundra active layer were incubated at 2, +4, or +8C for up to 60 days to mimic the short-term thaw season. Results suggest that, under anoxic conditions, fermentation converted complex organic molecules into simple organic acids that were used in concomitant Fe-reduction and acetoclastic methanogenesis reactions. Nonaromatic compounds increased over time as WEOC increased. Organic acid metabolites initially accumulated in soils but were mostly depleted by day 60 because organic acids were consumed to produce Fe(II), CO2, and CH4. We conclude that fermentation of nonprotected organic matter facilitates methanogenesis and Fe reduction reactions, and that the proportion of organic acids consumed by methanogenesis increases relative to Fe reduction with increasing temperature. As a result, the decomposition pathways observed in this study are important to consider in numerical modeling of greenhouse gas production in the Arctic.

  11. Pathways of anaerobic organic matter decomposition in tundra soils from Barrow, Alaska

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

    Herndon, Elizabeth M.; Mann, Benjamin F.; Chowdhury, Taniya Roy; Wullschleger, Stan D.; Graham, David E.; Liang, Liyuan; Gu, Baohua; Yang, Ziming

    2015-11-23

    Arctic tundra soils store a large quantity of organic carbon that is susceptible to decomposition and release to the atmosphere as methane (CH4) and carbon dioxide (CO2) under a warming climate. Anaerobic processes that generate CH4 and CO2 remain unclear because previous studies have focused on aerobic decomposition pathways. To predict releases of CO2 and CH4 from tundra soils, it is necessary to identify pathways of soil organic matter decomposition under the anoxic conditions that are prevalent in Arctic ecosystems. Here molecular and spectroscopic techniques were used to monitor biological degradation of water-extractable organic carbon (WEOC) during anoxic incubation ofmore » tundra soils from a region of continuous permafrost in northern Alaska. Organic and mineral soils from the tundra active layer were incubated at –2, +4, or +8°C for up to 60 days to mimic the short-term thaw season. Results suggest that, under anoxic conditions, fermentation converted complex organic molecules into simple organic acids that were used in concomitant Fe-reduction and acetoclastic methanogenesis reactions. Nonaromatic compounds increased over time as WEOC increased. Organic acid metabolites initially accumulated in soils but were mostly depleted by day 60 because organic acids were consumed to produce Fe(II), CO2, and CH4. We conclude that fermentation of nonprotected organic matter facilitates methanogenesis and Fe reduction reactions, and that the proportion of organic acids consumed by methanogenesis increases relative to Fe reduction with increasing temperature. As a result, the decomposition pathways observed in this study are important to consider in numerical modeling of greenhouse gas production in the Arctic.« less

  12. Dynamic load balancing algorithm for molecular dynamics based on Voronoi cells domain decompositions

    SciTech Connect (OSTI)

    Fattebert, J.-L.; Richards, D.F.; Glosli, J.N.

    2012-12-01

    We present a new algorithm for automatic parallel load balancing in classical molecular dynamics. It assumes a spatial domain decomposition of particles into Voronoi cells. It is a gradient method which attempts to minimize a cost function by displacing Voronoi sites associated with each processor/sub-domain along steepest descent directions. Excellent load balance has been obtained for quasi-2D and 3D practical applications, with up to 440106 particles on 65,536 MPI tasks.

  13. Hazardous materials: Microbiological decomposition. (Latest citations from the Biobusiness database). Published Search

    SciTech Connect (OSTI)

    Not Available

    1993-12-01

    The bibliography contains citations concerning the decomposition of toxic materials by biological means. Bacteria, enzymes, and bioluminescence are among the methods discussed. Bacteria and enzymes that digest toluene, polychlorinated biphenyls (PCBs), selenium wastes, oil shale waste, uranium, oil sludge, pesticides, rubber wastes, and pentachlorophenol are discussed. Flavobacterium and white rot fungus are among the biological agents highlighted. (Contains 250 citations and includes a subject term index and title list.)

  14. Hazardous materials: Microbiological decomposition. (Latest citations from the Biobusiness database). NewSearch

    SciTech Connect (OSTI)

    Not Available

    1994-10-01

    The bibliography contains citations concerning the decomposition of toxic materials by biological means. Bacteria, enzymes, and bioluminescence are among the methods discussed. Bacteria and enzymes that digest toluene, polychlorinated biphenyls (PCBs), selenium wastes, oil shale waste, uranium, oil sludge, pesticides, rubber wastes, and pentachlorophenol are discussed. Flavobacterium and white rot fungus are among the biological agents highlighted. (Contains 250 citations and includes a subject term index and title list.)

  15. Decomposition pathways of C2 oxygenates on Rh-modified tungsten carbide surfaces

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

    Kelly, Thomas G.; Ren, Hui; Chen, Jingguang G.

    2015-03-27

    Ethanol decomposition on tungsten monocarbide (WC) and Rh-modified WC was investigated using ultrahigh vacuum (UHV) surface science experiments and density functional theory (DFT) calculations. DFT calculations indicated that the binding energies of ethanol and its decomposition intermediates on WC(0001) were modified by Rh, with Rh/WC(0001) showing similar values to those on Rh(111). Through temperature-programmed desorption (TPD) experiments on polycrystalline WC and Rh-modified WC, it was shown that the selectivity for ethanol decomposition was different on these surfaces. On WC, the C-O bond of ethanol was preferentially broken to produce ethylene; on Rh-modified WC, the C-C bond was broken to producemore » carbon monoxide and methane. In addition, high-resolution electron energy loss spectroscopy (HREELS) was used to determine likely surface intermediates. On Rh-modified WC, ethanol first formed ethoxy through O-H scission, then reacted through an aldehyde intermediate to form the C1 products.« less

  16. Trends in Formic Acid Decomposition on Model Transition Metal Surfaces: A Density Functional Theory Study

    SciTech Connect (OSTI)

    Herron, Jeffrey A.; Scaranto, Jessica; Ferrin, Peter A.; Li, Sha; Mavrikakis, Manos

    2014-12-05

    We present a first-principles, self-consistent periodic density functional theory (PW91-GGA) study of formic acid (HCOOH) decomposition on model (111) and (100) facets of eight fcc metals (Au, Ag, Cu, Pt, Pd, Ni, Ir, and Rh) and (0001) facets of four hcp (Co, Os, Ru, and Re) metals. The calculated binding energies of key formic acid decomposition intermediates including formate (HCOO), carboxyl (COOH), carbon monoxide (CO), water (H2O), carbon dioxide (CO2), hydroxyl (OH), carbon (C), oxygen (O), and hydrogen (H; H2) are presented. Using these energetics, we develop thermochemical potential energy diagrams for both the carboxyl-mediated and the formate-mediated dehydrogenation mechanisms on each surface. We evaluate the relative stability of COOH, HCOO, and other isomeric intermediates (i.e., CO + OH, CO2 + H, CO + O + H) on these surfaces. These results provide insights into formic acid decomposition selectivity (dehydrogenation versus dehydration), and in conjunction with calculated vibrational frequency modes, the results can assist with the experimental search for the elusive carboxyl (COOH) surface intermediate. Results are compared against experimental reports in the literature.

  17. Decomposition pathways of C2 oxygenates on Rh-modified tungsten carbide surfaces

    SciTech Connect (OSTI)

    Kelly, Thomas G.; Ren, Hui; Chen, Jingguang G.

    2015-03-27

    Ethanol decomposition on tungsten monocarbide (WC) and Rh-modified WC was investigated using ultrahigh vacuum (UHV) surface science experiments and density functional theory (DFT) calculations. DFT calculations indicated that the binding energies of ethanol and its decomposition intermediates on WC(0001) were modified by Rh, with Rh/WC(0001) showing similar values to those on Rh(111). Through temperature-programmed desorption (TPD) experiments on polycrystalline WC and Rh-modified WC, it was shown that the selectivity for ethanol decomposition was different on these surfaces. On WC, the C-O bond of ethanol was preferentially broken to produce ethylene; on Rh-modified WC, the C-C bond was broken to produce carbon monoxide and methane. In addition, high-resolution electron energy loss spectroscopy (HREELS) was used to determine likely surface intermediates. On Rh-modified WC, ethanol first formed ethoxy through O-H scission, then reacted through an aldehyde intermediate to form the C1 products.

  18. Calculation of excitation energies from the CC2 linear response theory using Cholesky decomposition

    SciTech Connect (OSTI)

    Baudin, Pablo; qLEAP Center for Theoretical Chemistry, Department of Chemistry, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C ; Marn, Jos Snchez; Cuesta, Inmaculada Garca; Snchez de Mers, Alfredo M. J.

    2014-03-14

    A new implementation of the approximate coupled cluster singles and doubles CC2 linear response model is reported. It employs a Cholesky decomposition of the two-electron integrals that significantly reduces the computational cost and the storage requirements of the method compared to standard implementations. Our algorithm also exploits a partitioning form of the CC2 equations which reduces the dimension of the problem and avoids the storage of doubles amplitudes. We present calculation of excitation energies of benzene using a hierarchy of basis sets and compare the results with conventional CC2 calculations. The reduction of the scaling is evaluated as well as the effect of the Cholesky decomposition parameter on the quality of the results. The new algorithm is used to perform an extrapolation to complete basis set investigation on the spectroscopically interesting benzylallene conformers. A set of calculations on medium-sized molecules is carried out to check the dependence of the accuracy of the results on the decomposition thresholds. Moreover, CC2 singlet excitation energies of the free base porphin are also presented.

  19. Hydrogen-terminated silicon nanowire photocatalysis: Benzene oxidation and methyl red decomposition

    SciTech Connect (OSTI)

    Lian, Suoyuan; School of Chemical Engineering and Materials, Dalian Polytechnic University, Dalian 116034 ; Tsang, Chi Him A.; Centre of Super Diamond and Advanced Films, City University of Hong Kong, Hong Kong ; Kang, Zhenhui; Liu, Yang; Wong, Ningbew; Lee, Shuit-Tong; Centre of Super Diamond and Advanced Films, City University of Hong Kong, Hong Kong

    2011-12-15

    Graphical abstract: H-SiNWs can catalyze hydroxylation of benzene and degradation of methyl red under visible light irradiation. Highlights: Black-Right-Pointing-Pointer Hydrogen-terminated silicon nanowires were active photocatalyst in the hydroxylation of benzene under light. Black-Right-Pointing-Pointer Hydrogen-terminated silicon nanowires were also effective in the decomposition of methyl red dye. Black-Right-Pointing-Pointer The Si/SiO{sub x} core-shell structure is the main reason of the obtained high selectivity during the hydroxylation. -- Abstract: Hydrogen-terminated silicon nanowires (H-SiNWs) were used as heterogeneous photocatalysts for the hydroxylation of benzene and for the decomposition of methyl red under visible light irradiation. The above reactions were monitored by GC-MS and UV-Vis spectrophotometry, respectively, which shows 100% selectivity for the transformation of benzene to phenol. A complete decomposition of a 2 Multiplication-Sign 10{sup -4} M methyl red solution was achieved within 30 min. The high selectivity for the hydroxylation of benzene and the photodecomposition demonstrate the catalytic activity of ultrafine H-SiNWs during nanocatalysis.

  20. The response of the HMX-based material PBXN-9 to thermal insults: thermal decomposition kinetics and morphological changes

    SciTech Connect (OSTI)

    Glascoe, E A; Hsu, P C; Springer, H K; DeHaven, M R; Tan, N; Turner, H C

    2010-12-10

    PBXN-9, an HMX-formulation, is thermally damaged and thermally decomposed in order to determine the morphological changes and decomposition kinetics that occur in the material after mild to moderate heating. The material and its constituents were decomposed using standard thermal analysis techniques (DSC and TGA) and the decomposition kinetics are reported using different kinetic models. Pressed parts and prill were thermally damaged, i.e. heated to temperatures that resulted in material changes but did not result in significant decomposition or explosion, and analyzed. In general, the thermally damaged samples showed a significant increase in porosity and decrease in density and a small amount of weight loss. These PBXN-9 samples appear to sustain more thermal damage than similar HMX-Viton A formulations and the most likely reasons are the decomposition/evaporation of a volatile plasticizer and a polymorphic transition of the HMX from {beta} to {delta} phase.

  1. Decomposition of 1,1-Dichloroethane and 1,1-Dichloroethene in an electron beam generated plasma reactor

    SciTech Connect (OSTI)

    Vitale, S.A.; Hadidi, K.; Cohn, D.R.; Bromberg, L.

    1997-03-01

    An electron beam generated plasma reactor is used to decompose low concentrations (100{endash}3000 ppm) of 1,1-dichloroethane and 1,1-dichloroethene in atmospheric pressure air streams. The energy requirements for 90{percent} and 99{percent} decomposition of each compound are reported as a function of inlet concentration. Dichloroethene decomposition is enhanced by a chlorine radical propagated chain reaction. The chain length of the dichloroethene reaction is estimated to increase with dichloroethene concentration from 10 at 100 ppm initial dichloroethene concentration to 30 at 3000 ppm. Both the dichloroethane and dichloroethene reactions seem to be inhibited by electron scavenging decomposition products. A simple analytic expression is proposed for fitting decomposition data where inhibition effects are important and simple first order kinetics are not observed. {copyright} {ital 1997 American Institute of Physics.}

  2. Activation energy and enthalpy of decomposition for the Fe{sub 17}Sm{sub 2} nitride

    SciTech Connect (OSTI)

    Cabral, F.A.; Gama, S.; Ribeiro, C.A.

    1997-04-01

    Decomposition studies of the Fe{sub 17}Sm{sub 2}N{sub 3} compound were done using a Calvet-type microcalorimeter and a simultaneous gravimetric and differential thermal analyzer (DTA). The results show that the decomposition has onset temperature of 570{degree}C and proceeds up to 900{degree}C, and presents only one well determined exothermic thermal event. The calorimetric measurement shows that the enthalpy associated with the decomposition is 69 kJ/mol. The activation energy of the process was also determined using the Kissinger method applied to the DTA signal. It was observed that there was only one activation energy for the decomposition process, with a value of 339 kJ/mol. {copyright} {ital 1997 American Institute of Physics.}

  3. Second test of base hydrolysate decomposition in a 0.04 gallon per minute scale reactor

    SciTech Connect (OSTI)

    Cena, R.J.; Thorsness, C.B.; Coburn, T.T.; Watkins, B.E.

    1994-10-11

    LLNL has built and operated a pilot plant for processing oil shale using recirculating hot solids. This pilot plant, was adapted in 1993 to demonstrate the feasibility of decomposing base hydrolysate, a mixture of sodium nitrite, sodium formate and other constituents. This material is the waste stream from the base hydrolysis process for destruction of energetic materials. In the Livermore process, the waste feed is thermally treated in a moving packed bed of ceramic spheres, where constituents in the waste decompose, in the presence of carbon dioxide, to form solid sodium carbonate and a suite of gases including: methane, carbon monoxide, oxygen, nitrogen oxides, ammonia and possibly molecular nitrogen. The ceramic spheres are circulated and heated, providing the energy required for thermal decomposition. The spheres provide a large surface area for evaporation and decomposition to occur, avoiding sticking and agglomeration of the waste. We performed a 2.5 hour test of the solids recirculation system, with continuous injection of approximately 0.04 gal/min of waste. Gasses from the packed bed reactor were directed through the lift pipe and water was not condensed. Potassium carbonate (0.356 M) was added to the hydrolysate prior to its introduction to the retort. Continuous on-line gas analysis was invaluable in tracking the progress of the experiment and quantifying the decomposition products. Analyses showed the primary solid product, collected in the lift exit cyclone, was indeed sodium carbonate, as expected. For the reactor condition studied in this test, N{sub 2}O was found to be the primary nitrogen bearing gas species. In the test, approximately equal quantities of ammonia and nitrogen bearing oxide gases were produced. Under proper conditions, this ammonia and NO{sub x} can be recombined downstream to form N{sub 2} and O{sub 2} as the primary effluent gases.

  4. A quantitative acoustic emission study on fracture processes in ceramics based on wavelet packet decomposition

    SciTech Connect (OSTI)

    Ning, J. G.; Chu, L.; Ren, H. L.

    2014-08-28

    We base a quantitative acoustic emission (AE) study on fracture processes in alumina ceramics on wavelet packet decomposition and AE source location. According to the frequency characteristics, as well as energy and ringdown counts of AE, the fracture process is divided into four stages: crack closure, nucleation, development, and critical failure. Each of the AE signals is decomposed by a 2-level wavelet package decomposition into four different (from-low-to-high) frequency bands (AA{sub 2}, AD{sub 2}, DA{sub 2}, and DD{sub 2}). The energy eigenvalues P{sub 0}, P{sub 1}, P{sub 2}, and P{sub 3} corresponding to these four frequency bands are calculated. By analyzing changes in P{sub 0} and P{sub 3} in the four stages, we determine the inverse relationship between AE frequency and the crack source size during ceramic fracture. AE signals with regard to crack nucleation can be expressed when P{sub 0} is less than 5 and P{sub 3} more than 60; whereas AE signals with regard to dangerous crack propagation can be expressed when more than 92% of P{sub 0} is greater than 4, and more than 95% of P{sub 3} is less than 45. Geiger location algorithm is used to locate AE sources and cracks in the sample. The results of this location algorithm are consistent with the positions of fractures in the sample when observed under a scanning electronic microscope; thus the locations of fractures located with Geiger's method can reflect the fracture process. The stage division by location results is in a good agreement with the division based on AE frequency characteristics. We find that both wavelet package decomposition and Geiger's AE source locations are suitable for the identification of the evolutionary process of cracks in alumina ceramics.

  5. Optimal operational planning of cogeneration systems with thermal storage by the decomposition method

    SciTech Connect (OSTI)

    Yokoyama, R.; Ito, K.

    1995-12-01

    An optimal operational planning method is proposed for cogeneration systems with thermal storage. The daily operational strategy of constituent equipment is determined so as to minimize the daily operational cost subject to the energy demand requirement. This optimization problem is formulated as a large-scale mixed-integer linear programming one, and it is solved by means of the decomposition method. Effects of thermal storage on the operation of cogeneration systems are examined through a numerical study on a gas engine-driven cogeneration system installed in a hotel. This method is a useful tool for evaluating the economic and energy-saving properties of cogeneration systems with thermal storage.

  6. Integration of progressive hedging and dual decomposition in stochastic integer programs

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

    Watson, Jean -Paul; Guo, Ge; Hackebeil, Gabriel; Ryan, Sarah M.; Woodruff, David L.

    2015-04-07

    We present a method for integrating the Progressive Hedging (PH) algorithm and the Dual Decomposition (DD) algorithm of Carøe and Schultz for stochastic mixed-integer programs. Based on the correspondence between lower bounds obtained with PH and DD, a method to transform weights from PH to Lagrange multipliers in DD is found. Fast progress in early iterations of PH speeds up convergence of DD to an exact solution. As a result, we report computational results on server location and unit commitment instances.

  7. Effects of temperature on desiccant catalysis of refrigerant and lubricant decomposition. Final report

    SciTech Connect (OSTI)

    Rohatgi, N.D.T.

    1998-06-01

    Accelerated aging at high temperatures (149 C) for short aging times (28 days) is effective in screening the compatibility of different materials in refrigeration systems. However, in actual applications temperatures are usually lower and operating times much longer. Therefore plots to allow for interpolation or extrapolation of experimental data to actual operating conditions are needed. In the current study, aging of refrigerant/lubricant/desiccant/metal systems was conducted at five different temperatures, and for each temperature at four different aging times. The data collected from this study provided plots relating refrigerant or lubricant decomposition to aging time, aging temperature, and type of desiccant, which can be used for interpolation or extrapolation.

  8. Combined iterative reconstruction and image-domain decomposition for dual energy CT using total-variation regularization

    SciTech Connect (OSTI)

    Dong, Xue; Niu, Tianye; Zhu, Lei

    2014-05-15

    Purpose: Dual-energy CT (DECT) is being increasingly used for its capability of material decomposition and energy-selective imaging. A generic problem of DECT, however, is that the decomposition process is unstable in the sense that the relative magnitude of decomposed signals is reduced due to signal cancellation while the image noise is accumulating from the two CT images of independent scans. Direct image decomposition, therefore, leads to severe degradation of signal-to-noise ratio on the resultant images. Existing noise suppression techniques are typically implemented in DECT with the procedures of reconstruction and decomposition performed independently, which do not explore the statistical properties of decomposed images during the reconstruction for noise reduction. In this work, the authors propose an iterative approach that combines the reconstruction and the signal decomposition procedures to minimize the DECT image noise without noticeable loss of resolution. Methods: The proposed algorithm is formulated as an optimization problem, which balances the data fidelity and total variation of decomposed images in one framework, and the decomposition step is carried out iteratively together with reconstruction. The noise in the CT images from the proposed algorithm becomes well correlated even though the noise of the raw projections is independent on the two CT scans. Due to this feature, the proposed algorithm avoids noise accumulation during the decomposition process. The authors evaluate the method performance on noise suppression and spatial resolution using phantom studies and compare the algorithm with conventional denoising approaches as well as combined iterative reconstruction methods with different forms of regularization. Results: On the Catphan600 phantom, the proposed method outperforms the existing denoising methods on preserving spatial resolution at the same level of noise suppression, i.e., a reduction of noise standard deviation by one order of magnitude. This improvement is mainly attributed to the high noise correlation in the CT images reconstructed by the proposed algorithm. Iterative reconstruction using different regularization, including quadratic orq-generalized Gaussian Markov random field regularization, achieves similar noise suppression from high noise correlation. However, the proposed TV regularization obtains a better edge preserving performance. Studies of electron density measurement also show that our method reduces the average estimation error from 9.5% to 7.1%. On the anthropomorphic head phantom, the proposed method suppresses the noise standard deviation of the decomposed images by a factor of ?14 without blurring the fine structures in the sinus area. Conclusions: The authors propose a practical method for DECT imaging reconstruction, which combines the image reconstruction and material decomposition into one optimization framework. Compared to the existing approaches, our method achieves a superior performance on DECT imaging with respect to decomposition accuracy, noise reduction, and spatial resolution.

  9. Monitoring the formation of carbide crystal phases during the thermal decomposition of 3d transition metal dicarboxylate complexes

    SciTech Connect (OSTI)

    Huba, ZJ; Carpenter, EE

    2014-06-06

    Single molecule precursors can help to simplify the synthesis of complex alloys by minimizing the amount of necessary starting reagents. However, single molecule precursors are time consuming to prepare with very few being commercially available. In this study, a simple precipitation method is used to prepare Fe, Co, and Ni fumarate and succinate complexes. These complexes were then thermally decomposed in an inert atmosphere to test their efficiency as single molecule precursors for the formation of metal carbide phases. Elevated temperature X-ray diffraction was used to identify the crystal phases produced upon decomposition of the metal dicarboxylate complexes. Thermogravimetric analysis coupled with an infrared detector was used to identify the developed gaseous decomposition products. All complexes tested showed a reduction from the starting M2+ oxidation state to the M oxidation state, upon decomposition. Also, each complex tested showed CO2 and H2O as gaseous decomposition products. Nickel succinate, iron succinate, and iron fumarate complexes were found to form carbide phases upon decomposition. This proves that transition metal dicarboxylate salts can be employed as efficient single molecule precursors for the formation of metal carbide crystal phases.

  10. Theoretical Study of the Thermal Decomposition of Carboxylic Acids at Pyrolysis Temperature

    SciTech Connect (OSTI)

    Clark, J. M.; Robichaud, D. J.; Nimlos, M. R.

    2013-01-01

    Carboxylic acids are important in the processing of biomass into renewable fuels and chemicals. They are formed from the pretreatment and pyrolysis of hemicellulose biopolymers and are released from the decomposition of sugars. They result from the deconstruction of polyhydroxyalkanoates (bacterial carbon storage polymers) from fatty acids derived from algae, bacteria, and oil crops. The thermal deoxygenation of carboxylic acids is an important step in the conversion of biomass into aliphatic hydrocarbons suitable for use in renewable biofuels and as petrochemical replacements. Decarboxylation, a primary decomposition pathway under pyrolysis conditions, represents an ideal conversion process, because it eliminates two atoms of oxygen for every carbon atom removed. Problematically, additional deoxygenation processes exist (e.g. dehydration) that are in direct competition with decarboxylation and result in the formation of reactive and more fragmented end products. To better understand the competition between decarboxylation and other deoxygenation processes and to gain insight into possible catalysts that would favor decarboxylation, we have investigated the mechanisms and thermochemistry of the various unimolecular and bimolecular deoxygenation pathways for a family of C1-C4 organic acids using electronic structure calculations at the M06-2X/6-311++G(2df,p) level of theory.

  11. HYBRID SULFUR FLOWSHEETS USING PEM ELECTROLYSIS AND A BAYONET DECOMPOSITION REACTOR

    SciTech Connect (OSTI)

    Gorensek, M; William Summers, W

    2008-05-30

    A conceptual design is presented for a Hybrid Sulfur process for the production of hydrogen using a high-temperature nuclear heat source to split water. The process combines proton exchange membrane-based SO{sub 2}-depolarized electrolyzer technology being developed at Savannah River National Laboratory with silicon carbide bayonet decomposition reactor technology being developed at Sandia National Laboratories. Both are part of the US DOE Nuclear Hydrogen Initiative. The flowsheet otherwise uses only proven chemical process components. Electrolyzer product is concentrated from 50 wt% sulfuric acid to 75 wt% via recuperative vacuum distillation. Pinch analysis is used to predict the high-temperature heat requirement for sulfuric acid decomposition. An Aspen Plus{trademark} model of the flowsheet indicates 340.3 kJ high-temperature heat, 75.5 kJ low-temperature heat, 1.31 kJ low-pressure steam, and 120.9 kJ electric power are consumed per mole of H{sub 2} product, giving an LHV efficiency of 35.3% (41.7% HHV efficiency) if electric power is available at a conversion efficiency of 45%.

  12. Synthesis and in vacuo deposition of iron oxide nanoparticles by microplasma-assisted decomposition of ferrocene

    SciTech Connect (OSTI)

    Schaefer, Michael E-mail: axk650@case.edu E-mail: schlaf@mail.usf.edu; Kumar, Ajay E-mail: axk650@case.edu E-mail: schlaf@mail.usf.edu; Mohan Sankaran, R. E-mail: axk650@case.edu E-mail: schlaf@mail.usf.edu; Schlaf, Rudy E-mail: axk650@case.edu E-mail: schlaf@mail.usf.edu

    2014-10-07

    Microplasma-assisted gas-phase nucleation has emerged as an important new approach to produce high-purity, nanometer-sized, and narrowly dispersed particles. This study aims to integrate this technique with vacuum conditions to enable synthesis and deposition in an ultrahigh vacuum compatible environment. The ultimate goal is to combine nanoparticle synthesis with photoemission spectroscopy-based electronic structure analysis. Such measurements require in vacuo deposition to prevent surface contamination from sample transfer, which can be deleterious for nanoscale materials. A homebuilt microplasma reactor was integrated into an existing atomic layer deposition system attached to a surface science multi-chamber system equipped with photoemission spectroscopy. As proof-of-concept, we studied the decomposition of ferrocene vapor in the microplasma to synthesize iron oxide nanoparticles. The injection parameters were optimized to achieve complete precursor decomposition under vacuum conditions, and nanoparticles were successfully deposited. The stoichiometry of the deposited samples was characterized in situ using X-ray photoelectron spectroscopy indicating that iron oxide was formed. Additional transmission electron spectroscopy characterization allowed the determination of the size, shape, and crystal lattice of the particles, confirming their structural properties.

  13. METHANE HYDRATE STUDIES: DELINEATING PROPERTIES OF HOST SEDIMENTS TO ESTABLISH REPRODUCIBLE DECOMPOSITION KINETICS.

    SciTech Connect (OSTI)

    Mahajan, Devinder; Jones, Keith W.; Feng, Huan; Winters, William J.

    2004-12-01

    The use of methane hydrate as an energy source requires development of a reliable method for its extraction from its highly dispersed locations in oceanic margin sediments and permafrost. The high pressure (up to 70 MPa) and low temperature (272 K to 278 K) conditions under which hydrates are stable in the marine environment can be mimicked in a laboratory setting and several kinetic studies of pure methane hydrate decomposition have been reported. However, the effect of host sediments on methane hydrate occurrence and decomposition are required to develop reliable hydrate models. In this paper, we describe methods to measure sediment properties as they relate to pore-space methane gas hydrate. Traditional geotechnical techniques are compared to the micrometer level by use of the synchrotron Computed Microtomography (CMT) technique. CMT was used to measure the porosity at the micrometer level and to show pore-space pathways through field samples. Porosities for three sediment samples: one from a site on Georges Bank and two from the known Blake Ridge methane hydrate site, from different depths below the mud line were measured by traditional drying and by the new CMT techniques and found to be in good agreement. The integration of the two analytical approaches is necessary to enable better understanding of methane hydrate interactions with the surrounding sediment particles.

  14. Is the resilience of C{sub 60}{sup +} towards decomposition a question of time?

    SciTech Connect (OSTI)

    Lifshitz, C.; Sandler, P.; Gotkis, I.; Laskin, J.

    1993-12-31

    The authors have measured kinetic energy release distributions (KERDs) for the evaporation of C{sub 2} from C{sub 60}{sup +} and other fullerene cations. Through analysis of the KERDs by Klot`s theory the authors determined binding energies -- the C{sub 2} binding energy in C{sub 60}{sup +} is 5.23 eV. A thermochemical cycle gave 5.77 eV as the C{sub 2} binding energy in C{sub 60} neutral. Once these binding energies were known, it enabled calculations of time resolved breakdown curves for parent and daughter ions. These calculations included the option of energy relaxation through emission in the infra-red. It was found that C{sub 60}{sup +} is almost completely undissociated at t = 1 {mu}s at an internal energy of 30 eV. However, at t = 1s, it is completely dissociated. An intrinsic shift (IS) of 16.2 eV is predicted. These results explain SID (Surface Induced Decomposition) data by Whetten and coworkers. The applicability of Trouton`s Rule and evaporation to fullerene decompositions will be discussed. Alternative mechanisms, including the Rice {open_quotes}shrink wrap{close_quotes} mechanism, will be discussed in view of the apparent universality of the Gspann parameter, {gamma}=23.5.

  15. Trends in Methanol Decomposition on Transition Metal Alloy Clusters from Scaling and BrnstedEvansPolanyi Relationships

    SciTech Connect (OSTI)

    Mehmood, Faisal; Rankin, Rees B.; Greeley, Jeffrey P.; Curtiss, Larry A.

    2012-05-15

    A combination of ?rst principles Density Functional Theory calculations and thermochemical scaling relationships are employed to estimate the thermochemistry and kinetics of methanol decomposition on unsupported subnanometer metal clusters. The approach uses binding energies of various atomic and molecular species, determined on the pure metal clusters, to develop scaling relationships that are then further used to estimate the methanol decomposition thermodynamics for a series of pure and bimetallic clusters with four atoms per cluster. Additionally, activation energy barriers are estimated from BrnstedEvansPolanyi plots relating transition and ?nal state energies on these clusters. The energetic results are combined with a simple, microkineticallyinspired rate expression to estimate reaction rates as a function of important catalytic descriptors, including the carbon and atomic oxygen binding energies to the clusters. Based on these analyses, several alloy clusters are identi?ed as promising candidates for the methanol decomposition reaction.

  16. Hybrid and Parallel Domain-Decomposition Methods Development to Enable Monte Carlo for Reactor Analyses

    SciTech Connect (OSTI)

    Wagner, John C; Mosher, Scott W; Evans, Thomas M; Peplow, Douglas E.; Turner, John A

    2011-01-01

    This paper describes code and methods development at the Oak Ridge National Laboratory focused on enabling high-fidelity, large-scale reactor analyses with Monte Carlo (MC). Current state-of-the-art tools and methods used to perform real commercial reactor analyses have several undesirable features, the most significant of which is the non-rigorous spatial decomposition scheme. Monte Carlo methods, which allow detailed and accurate modeling of the full geometry and are considered the gold standard for radiation transport solutions, are playing an ever-increasing role in correcting and/or verifying the deterministic, multi-level spatial decomposition methodology in current practice. However, the prohibitive computational requirements associated with obtaining fully converged, system-wide solutions restrict the role of MC to benchmarking deterministic results at a limited number of state-points for a limited number of relevant quantities. The goal of this research is to change this paradigm by enabling direct use of MC for full-core reactor analyses. The most significant of the many technical challenges that must be overcome are the slow, non-uniform convergence of system-wide MC estimates and the memory requirements associated with detailed solutions throughout a reactor (problems involving hundreds of millions of different material and tally regions due to fuel irradiation, temperature distributions, and the needs associated with multi-physics code coupling). To address these challenges, our research has focused on the development and implementation of (1) a novel hybrid deterministic/MC method for determining high-precision fluxes throughout the problem space in k-eigenvalue problems and (2) an efficient MC domain-decomposition (DD) algorithm that partitions the problem phase space onto multiple processors for massively parallel systems, with statistical uncertainty estimation. The hybrid method development is based on an extension of the FW-CADIS method, which attempts to achieve uniform statistical uncertainty throughout a designated problem space. The MC DD development is being implemented in conjunction with the Denovo deterministic radiation transport package to have direct access to the 3-D, massively parallel discrete-ordinates solver (to support the hybrid method) and the associated parallel routines and structure. This paper describes the hybrid method, its implementation, and initial testing results for a realistic 2-D quarter core pressurized-water reactor model and also describes the MC DD algorithm and its implementation.

  17. Hybrid and Parallel Domain-Decomposition Methods Development to Enable Monte Carlo for Reactor Analyses

    SciTech Connect (OSTI)

    Wagner, John C; Mosher, Scott W; Evans, Thomas M; Peplow, Douglas E.; Turner, John A

    2010-01-01

    This paper describes code and methods development at the Oak Ridge National Laboratory focused on enabling high-fidelity, large-scale reactor analyses with Monte Carlo (MC). Current state-of-the-art tools and methods used to perform ''real'' commercial reactor analyses have several undesirable features, the most significant of which is the non-rigorous spatial decomposition scheme. Monte Carlo methods, which allow detailed and accurate modeling of the full geometry and are considered the ''gold standard'' for radiation transport solutions, are playing an ever-increasing role in correcting and/or verifying the deterministic, multi-level spatial decomposition methodology in current practice. However, the prohibitive computational requirements associated with obtaining fully converged, system-wide solutions restrict the role of MC to benchmarking deterministic results at a limited number of state-points for a limited number of relevant quantities. The goal of this research is to change this paradigm by enabling direct use of MC for full-core reactor analyses. The most significant of the many technical challenges that must be overcome are the slow, non-uniform convergence of system-wide MC estimates and the memory requirements associated with detailed solutions throughout a reactor (problems involving hundreds of millions of different material and tally regions due to fuel irradiation, temperature distributions, and the needs associated with multi-physics code coupling). To address these challenges, our research has focused on the development and implementation of (1) a novel hybrid deterministic/MC method for determining high-precision fluxes throughout the problem space in k-eigenvalue problems and (2) an efficient MC domain-decomposition (DD) algorithm that partitions the problem phase space onto multiple processors for massively parallel systems, with statistical uncertainty estimation. The hybrid method development is based on an extension of the FW-CADIS method, which attempts to achieve uniform statistical uncertainty throughout a designated problem space. The MC DD development is being implemented in conjunction with the Denovo deterministic radiation transport package to have direct access to the 3-D, massively parallel discrete-ordinates solver (to support the hybrid method) and the associated parallel routines and structure. This paper describes the hybrid method, its implementation, and initial testing results for a realistic 2-D quarter core pressurized-water reactor model and also describes the MC DD algorithm and its implementation.

  18. Sapphire decomposition and inversion domains in N-polar aluminum nitride

    SciTech Connect (OSTI)

    Hussey, Lindsay White, Ryan M.; Kirste, Ronny; Bryan, Isaac; Guo, Wei; Osterman, Katherine; Haidet, Brian; Bryan, Zachary; Bobea, Milena; Collazo, Ramn; Sitar, Zlatko; Mita, Seiji

    2014-01-20

    Transmission electron microscopy (TEM) techniques and potassium hydroxide (KOH) etching confirmed that inversion domains in the N-polar AlN grown on c-plane sapphire were due to the decomposition of sapphire in the presence of hydrogen. The inversion domains were found to correspond to voids at the AlN and sapphire interface, and transmission electron microscopy results showed a V-shaped, columnar inversion domain with staggered domain boundary sidewalls. Voids were also observed in the simultaneously grown Al-polar AlN, however no inversion domains were present. The polarity of AlN grown above the decomposed regions of the sapphire substrate was confirmed to be Al-polar by KOH etching and TEM.

  19. FETI Prime Domain Decomposition base Parallel Iterative Solver Library Ver.1.0

    Energy Science and Technology Software Center (OSTI)

    2003-09-15

    FETI Prime is a library for the iterative solution of linear equations in solid and structural mechanics. The algorithm employs preconditioned conjugate gradients, with a domain decomposition-based preconditioner. The software is written in C++ and is designed for use with massively parallel computers, using MPI. The algorithm is based on the FETI-DP method, with additional capabilities for handling constraint equations, as well as interfacing with the Salinas structural dynamics code and the Finite Element Interfacemore » (FEI) library. Practical Application: FETI Prime is designed for use with finite element-based simulation codes for solid and structural mechanics. The solver uses element matrices, connectivity information, nodal information, and force vectors computed by the host code and provides back the solution to the linear system of equations, to the user specified level of accuracy, The library is compiled with the host code and becomes an integral part of the host code executable.« less

  20. Method for hydroperoxide decomposition using novel porphyrins synthesized from dipyrromethanes and aldehydes

    DOE Patents [OSTI]

    Wijesekera, Tilak; Lyons, James E.; Ellis, Jr., Paul E.

    1998-01-01

    The invention comprises a method for the oxidation of alkanes to alcohols and for decomposition of hydroperoxides to alcohols utilizing new compositions of matter, which are metal complexes of porphyrins. Preferred complexes have hydrogen, haloalkyl or haloaryl groups in meso positions, two of the opposed meso atoms or groups being hydrogen or haloaryl, and two of the opposed meso atoms or groups being hydrogen or haloalkyl, but not all four of the meso atoms or groups being hydrogen. Other preferred complexes are ones in which all four of the meso positions are substituted with haloalkyl groups and the beta positions are substituted with halogen atoms. A new method of synthesizing porphyrinogens is also disclosed.

  1. Method for hydroperoxide decomposition using novel porphyrins synthesized from dipyrromethanes and aldehydes

    DOE Patents [OSTI]

    Wijesekera, T.; Lyons, J.E.; Ellis, P.E. Jr.

    1998-03-03

    The invention comprises a method for the oxidation of alkanes to alcohols and for decomposition of hydroperoxides to alcohols utilizing new compositions of matter, which are metal complexes of porphyrins. Preferred complexes have hydrogen, haloalkyl or haloaryl groups in meso positions, two of the opposed meso atoms or groups being hydrogen or haloaryl, and two of the opposed meso atoms or groups being hydrogen or haloalkyl, but not all four of the meso atoms or groups being hydrogen. Other preferred complexes are ones in which all four of the meso positions are substituted with haloalkyl groups and the beta positions are substituted with halogen atoms. A new method of synthesizing porphyrinogens is also disclosed.

  2. Optimization-based additive decomposition of weakly coercive problems with applications

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

    Bochev, Pavel B.; Ridzal, Denis

    2016-01-27

    In this study, we present an abstract mathematical framework for an optimization-based additive decomposition of a large class of variational problems into a collection of concurrent subproblems. The framework replaces a given monolithic problem by an equivalent constrained optimization formulation in which the subproblems define the optimization constraints and the objective is to minimize the mismatch between their solutions. The significance of this reformulation stems from the fact that one can solve the resulting optimality system by an iterative process involving only solutions of the subproblems. Consequently, assuming that stable numerical methods and efficient solvers are available for every subproblem,more » our reformulation leads to robust and efficient numerical algorithms for a given monolithic problem by breaking it into subproblems that can be handled more easily. An application of the framework to the Oseen equations illustrates its potential.« less

  3. Validation of Heat Transfer Thermal Decomposition and Container Pressurization of Polyurethane Foam.

    SciTech Connect (OSTI)

    Scott, Sarah Nicole; Dodd, Amanda B.; Larsen, Marvin E.; Suo-Anttila, Jill M.; Erickson, Kenneth L

    2014-09-01

    Polymer foam encapsulants provide mechanical, electrical, and thermal isolation in engineered systems. In fire environments, gas pressure from thermal decomposition of polymers can cause mechanical failure of sealed systems. In this work, a detailed uncertainty quantification study of PMDI-based polyurethane foam is presented to assess the validity of the computational model. Both experimental measurement uncertainty and model prediction uncertainty are examined and compared. Both the mean value method and Latin hypercube sampling approach are used to propagate the uncertainty through the model. In addition to comparing computational and experimental results, the importance of each input parameter on the simulation result is also investigated. These results show that further development in the physics model of the foam and appropriate associated material testing are necessary to improve model accuracy.

  4. Growth and stability of oxidation resistant Si nanocrystals formed by decomposition of alkyl silanes

    SciTech Connect (OSTI)

    Zaitseva, N; Hamel, S; Dai, Z R; Saw, C; Williamson, A J; Galli, G

    2007-01-12

    The synthesis and characterization of 1-10 nm Si nanocrystals highly resistant to oxidation is described. The nanocrystals were prepared by thermal decomposition of tetramethylsilane at 680 C, or in a gold- induced catalytic process at lower temperatures down to 400-450 C using trioctylamine as an initial solvent. Transmission electron microscopic analysis of samples obtained in the presence of gold show that the nanocrystals form via solid-phase epitaxial attachment of Si to the gold crystal lattice. The results of computational modeling performed using first principles density functional theory (DFT) calculations predict that the enhanced stability of nanocrystals to oxidation is due to the presence of N or N-containing groups on the surface of nanocrystals.

  5. Low-rank matrix decomposition and spatio-temporal sparse recovery for STAP radar

    SciTech Connect (OSTI)

    Sen, Satyabrata

    2015-08-04

    We develop space-time adaptive processing (STAP) methods by leveraging the advantages of sparse signal processing techniques in order to detect a slowly-moving target. We observe that the inherent sparse characteristics of a STAP problem can be formulated as the low-rankness of clutter covariance matrix when compared to the total adaptive degrees-of-freedom, and also as the sparse interference spectrum on the spatio-temporal domain. By exploiting these sparse properties, we propose two approaches for estimating the interference covariance matrix. In the first approach, we consider a constrained matrix rank minimization problem (RMP) to decompose the sample covariance matrix into a low-rank positive semidefinite and a diagonal matrix. The solution of RMP is obtained by applying the trace minimization technique and the singular value decomposition with matrix shrinkage operator. Our second approach deals with the atomic norm minimization problem to recover the clutter response-vector that has a sparse support on the spatio-temporal plane. We use convex relaxation based standard sparse-recovery techniques to find the solutions. With extensive numerical examples, we demonstrate the performances of proposed STAP approaches with respect to both the ideal and practical scenarios, involving Doppler-ambiguous clutter ridges, spatial and temporal decorrelation effects. As a result, the low-rank matrix decomposition based solution requires secondary measurements as many as twice the clutter rank to attain a near-ideal STAP performance; whereas the spatio-temporal sparsity based approach needs a considerably small number of secondary data.

  6. Low-rank matrix decomposition and spatio-temporal sparse recovery for STAP radar

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

    Sen, Satyabrata

    2015-08-04

    We develop space-time adaptive processing (STAP) methods by leveraging the advantages of sparse signal processing techniques in order to detect a slowly-moving target. We observe that the inherent sparse characteristics of a STAP problem can be formulated as the low-rankness of clutter covariance matrix when compared to the total adaptive degrees-of-freedom, and also as the sparse interference spectrum on the spatio-temporal domain. By exploiting these sparse properties, we propose two approaches for estimating the interference covariance matrix. In the first approach, we consider a constrained matrix rank minimization problem (RMP) to decompose the sample covariance matrix into a low-rank positivemore » semidefinite and a diagonal matrix. The solution of RMP is obtained by applying the trace minimization technique and the singular value decomposition with matrix shrinkage operator. Our second approach deals with the atomic norm minimization problem to recover the clutter response-vector that has a sparse support on the spatio-temporal plane. We use convex relaxation based standard sparse-recovery techniques to find the solutions. With extensive numerical examples, we demonstrate the performances of proposed STAP approaches with respect to both the ideal and practical scenarios, involving Doppler-ambiguous clutter ridges, spatial and temporal decorrelation effects. As a result, the low-rank matrix decomposition based solution requires secondary measurements as many as twice the clutter rank to attain a near-ideal STAP performance; whereas the spatio-temporal sparsity based approach needs a considerably small number of secondary data.« less

  7. Simulation of toluene decomposition in a pulse-periodic discharge operating in a mixture of molecular nitrogen and oxygen

    SciTech Connect (OSTI)

    Trushkin, A. N.; Kochetov, I. V.

    2012-05-15

    The kinetic model of toluene decomposition in nonequilibrium low-temperature plasma generated by a pulse-periodic discharge operating in a mixture of nitrogen and oxygen is developed. The results of numerical simulation of plasma-chemical conversion of toluene are presented; the main processes responsible for C{sub 6}H{sub 5}CH{sub 3} decomposition are identified; the contribution of each process to total removal of toluene is determined; and the intermediate and final products of C{sub 6}H{sub 5}CH{sub 3} decomposition are identified. It was shown that toluene in pure nitrogen is mostly decomposed in its reactions with metastable N{sub 2}(A{sub 3}{Sigma}{sub u}{sup +}) and N{sub 2}(a Prime {sup 1}{Sigma}{sub u}{sup -}) molecules. In the presence of oxygen, in the N{sub 2} : O{sub 2} gas mixture, the largest contribution to C{sub 6}H{sub 5}CH{sub 3} removal is made by the hydroxyl radical OH which is generated in this mixture exclusively due to plasma-chemical reactions between toluene and oxygen decomposition products. Numerical simulation showed the existence of an optimum oxygen concentration in the mixture, at which toluene removal is maximum at a fixed energy deposition.

  8. Decomposition of the scattering amplitude into shadow and surface components with inclusion of spin-orbit coupling

    SciTech Connect (OSTI)

    Melo, German; David, Jorge; Restrepo, Albeiro

    2008-09-15

    We propose a decomposition of the scattering amplitude into shadow and surface components for proton scattering against calcium isotopes as targets at 21 MeV. We account for spin-orbit coupling effects for the optical potential in the nonrelativistic limit. Our calculations show very good agreement with experimental trends.

  9. New bounding and decomposition approaches for MILP investment problems: Multi-area transmission and generation planning under policy constraints

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

    Munoz, F. D.; Hobbs, B. F.; Watson, J. -P.

    2016-02-01

    A novel two-phase bounding and decomposition approach to compute optimal and near-optimal solutions to large-scale mixed-integer investment planning problems is proposed and it considers a large number of operating subproblems, each of which is a convex optimization. Our motivating application is the planning of power transmission and generation in which policy constraints are designed to incentivize high amounts of intermittent generation in electric power systems. The bounding phase exploits Jensen’s inequality to define a lower bound, which we extend to stochastic programs that use expected-value constraints to enforce policy objectives. The decomposition phase, in which the bounds are tightened, improvesmore » upon the standard Benders’ algorithm by accelerating the convergence of the bounds. The lower bound is tightened by using a Jensen’s inequality-based approach to introduce an auxiliary lower bound into the Benders master problem. Upper bounds for both phases are computed using a sub-sampling approach executed on a parallel computer system. Numerical results show that only the bounding phase is necessary if loose optimality gaps are acceptable. But, the decomposition phase is required to attain optimality gaps. Moreover, use of both phases performs better, in terms of convergence speed, than attempting to solve the problem using just the bounding phase or regular Benders decomposition separately.« less

  10. Thermal Decomposition Characteristics of Orthorhombic Ammonium Perchlorate (o-AP) and an 0-AP/HTPB-Based Propellant

    SciTech Connect (OSTI)

    BEHRENS JR.,RICHARD; MINIER,LEANNA M.G.

    1999-10-25

    A study to characterize the low-temperature reactive processes for o-AP and an AP/HTPB-based propellant (class 1.3) is being conducted in the laboratory using the techniques of simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS) and scanning electron microscopy (SEM). The results presented in this paper are a follow up of the previous work that showed the overall decomposition to be complex and controlled by both physical and chemical processes. The decomposition is characterized by the occurrence of one major event that consumes up to {approx}35% of the AP, depending upon particle size, and leaves behind a porous agglomerate of AP. The major gaseous products released during this event include H{sub 2}O, O{sub 2}, Cl{sub 2}, N{sub 2}O and HCl. The recent efforts provide further insight into the decomposition processes for o-AP. The temporal behaviors of the gas formation rates (GFRs) for the products indicate that the major decomposition event consists of three chemical channels. The first and third channels are affected by the pressure in the reaction cell and occur at the surface or in the gas phase above the surface of the AP particles. The second channel is not affected by pressure and accounts for the solid-phase reactions characteristic of o-AP. The third channel involves the interactions of the decomposition products with the surface of the AP. SEM images of partially decomposed o-AP provide insight to how the morphology changes as the decomposition progresses. A conceptual model has been developed, based upon the STMBMS and SEM results, that provides a basic description of the processes. The thermal decomposition characteristics of the propellant are evaluated from the identities of the products and the temporal behaviors of their GFRs. First, the volatile components in the propellant evolve from the propellant as it is heated. Second, the hot AP (and HClO{sub 4}) at the AP-binder interface oxidize the binder through reactions that preferentially strip the hydrogen from the binder and yield HCl and H{sub 2}O with some oxidation of the carbon from the binder. Third, the o-AP in the propellant decomposes in the same manner as in neat o-AP. Finally, AP-derived gaseous products interact with other ingredients in the propellant.

  11. Synthesis of phase-pure and monodisperse iron oxide nanoparticles by thermal decomposition

    SciTech Connect (OSTI)

    Hufschmid, Ryan D.; Arami, Hamed; Ferguson, R. Matthew; Gonzales, Marcela; Teeman, Eric M.; Brush, Lucien N.; Browning, Nigel D.; Krishnan, Kannan M.

    2015-06-03

    We present a comprehensive template for the design and synthesis of iron oxide nanoparticles with control over size, size distribution, phase, and resulting properties. Monodisperse superparamagnetic iron oxide nanoparticles were synthesized by thermal decomposition of three different iron containing precursors (iron oleate, iron pentacarbonyl, and iron oxyhydroxide) in organic solvents under a variety of synthetic conditions. We compare the suitability of these three kinetically controlled synthesis protocols, which have in common the use of iron oleate as a starting precursor or reaction intermediate, for producing nanoparticles with specific size and magnetic properties. Monodisperse particles were produced over a tunable range of sizes from approximately 2-30 nm. Reaction parameters such as precursor concentration, addition of surfactant, temperature, ramp rate, and time were adjusted to kinetically control size and size-distribution. In particular, large quantities of excess surfactant (up to 25:1 molar ratio) alter reaction kinetics and result in larger particles with uniform size; however, there is often a trade-off between large particles and a narrow size distribution. Iron oxide phase is also critical for establishing magnetic properties. As an example, we show the importance of obtaining the required iron oxide phase for application to Magnetic Particle Imaging (MPI), and describe how phase purity can be controlled.

  12. Demonstration of base catalyzed decomposition process, Navy Public Works Center, Guam, Mariana Islands

    SciTech Connect (OSTI)

    Schmidt, A.J.; Freeman, H.D.; Brown, M.D.; Zacher, A.H.; Neuenschwander, G.N.; Wilcox, W.A.; Gano, S.R.; Kim, B.C.; Gavaskar, A.R.

    1996-02-01

    Base Catalyzed Decomposition (BCD) is a chemical dehalogenation process designed for treating soils and other substrate contaminated with polychlorinated biphenyls (PCB), pesticides, dioxins, furans, and other hazardous organic substances. PCBs are heavy organic liquids once widely used in industry as lubricants, heat transfer oils, and transformer dielectric fluids. In 1976, production was banned when PCBs were recognized as carcinogenic substances. It was estimated that significant quantities (one billion tons) of U.S. soils, including areas on U.S. military bases outside the country, were contaminated by PCB leaks and spills, and cleanup activities began. The BCD technology was developed in response to these activities. This report details the evolution of the process, from inception to deployment in Guam, and describes the process and system components provided to the Navy to meet the remediation requirements. The report is divided into several sections to cover the range of development and demonstration activities. Section 2.0 gives an overview of the project history. Section 3.0 describes the process chemistry and remediation steps involved. Section 4.0 provides a detailed description of each component and specific development activities. Section 5.0 details the testing and deployment operations and provides the results of the individual demonstration campaigns. Section 6.0 gives an economic assessment of the process. Section 7.0 presents the conclusions and recommendations form this project. The appendices contain equipment and instrument lists, equipment drawings, and detailed run and analytical data.

  13. Unveiling the proton spin decomposition at a future electron-ion collider

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

    Aschenauer, Elke C.; Sassot, Rodolfo; Stratmann, Marco

    2015-11-24

    We present a detailed assessment of how well a future electron-ion collider could constrain helicity parton distributions in the nucleon and, therefore, unveil the role of the intrinsic spin of quarks and gluons in the proton’s spin budget. Any remaining deficit in this decomposition will provide the best indirect constraint on the contribution due to the total orbital angular momenta of quarks and gluons. Specifically, all our studies are performed in the context of global QCD analyses based on realistic pseudodata and in the light of the most recent data obtained from polarized proton-proton collisions at BNL-RHIC that have providedmore » evidence for a significant gluon polarization in the accessible, albeit limited range of momentum fractions. We also present projections on what can be achieved on the gluon’s helicity distribution by the end of BNL-RHIC operations. As a result, all estimates of current and projected uncertainties are performed with the robust Lagrange multiplier technique.« less

  14. Orthogonal decomposition as a design tool: With application to a mixing impeller

    SciTech Connect (OSTI)

    Sloan, Benjamin

    2013-05-15

    Digital manufacturing eliminates the expense and time required to develop custom products. By utilizing this technology, designers can quickly create a customized product specifically for their performance needs. But the timescale and expense from the engineering design workflows used to develop these customized products have not been adapted from the workflows used in mass production. In many cases these customized designs build upon already successful mass-produced products that were developed using conventional engineering design workflows. Many times as part of this conventional design process significant time is spent creating and validating high fidelity models that accurately predict the performance of the final design. These existing validated high fidelity models used for the mass-produced design can be reused for analysis and design of unknown products. This thesis explores the integration of reduced order modeling and detailed analysis into the engineering design workflow developing a customized design using digital manufacturing. Specifically, detailed analysis is coupled with proper orthogonal decomposition to enable the exploration of the design space while simultaneously shaping the model representing the design. This revised workflow is examined using the design of a laboratory scale overhead mixer impeller. The case study presented here is compared with the design of the Kar Dynamic Mixer impeller developed by The Dow Chemical Company. The result of which is a customized design for a refined set of operating conditions with improved performance.

  15. Unveiling the proton spin decomposition at a future electron-ion collider

    SciTech Connect (OSTI)

    Aschenauer, Elke C.; Sassot, Rodolfo; Stratmann, Marco

    2015-11-24

    We present a detailed assessment of how well a future electron-ion collider could constrain helicity parton distributions in the nucleon and, therefore, unveil the role of the intrinsic spin of quarks and gluons in the protons spin budget. Any remaining deficit in this decomposition will provide the best indirect constraint on the contribution due to the total orbital angular momenta of quarks and gluons. Specifically, all our studies are performed in the context of global QCD analyses based on realistic pseudodata and in the light of the most recent data obtained from polarized proton-proton collisions at BNL-RHIC that have provided evidence for a significant gluon polarization in the accessible, albeit limited range of momentum fractions. We also present projections on what can be achieved on the gluons helicity distribution by the end of BNL-RHIC operations. As a result, all estimates of current and projected uncertainties are performed with the robust Lagrange multiplier technique.

  16. The surface quasiliquid melt acceleration and the role of thermodynamic phase in the thermal decomposition of crystalline organic explosives

    SciTech Connect (OSTI)

    Henson, Bryan F

    2010-01-01

    We show that melt acceleration in the thermal decomposition of crystalline organic solids is a manifestation of the surface quasiliquid phase. We derive a single universal rate law for melt acceleration that is a simple function of the metastable liquid activity below the melting point, and has a zero order term proportional to the quasiliquid thickness. We argue that the underlying mechanisms of this model will provide a molecular definition for the stability of the class of secondary explosives.

  17. A comparative density functional study of methanol decomposition on Cu{sub 4} and Co{sub 4} clusters.

    SciTech Connect (OSTI)

    Mehmood, F.; Greeley, J.; Zapol, P.; Curtiss, L. A.

    2010-08-12

    A density functional theory study of the decomposition of methanol on Cu{sub 4} and Co{sub 4} clusters is presented. The reaction intermediates and activation barriers have been determined for reaction steps to form H{sub 2} and CO. For both clusters, methanol decomposition initiated by C-H and O-H bond breaking was investigated. In the case of a Cu{sub 4} cluster, methanol dehydrogenation through hydroxymethyl (CH{sub 2}OH), hydroxymethylene (CHOH), formyl (CHO), and carbon monoxide (CO) is found to be slightly more favorable. For a Co{sub 4} cluster, the dehydrogenation pathway through methoxy (CH{sub 3}O) and formaldehyde (CH{sub 2}O) is slightly more favorable. Each of these pathways results in formation of CO and H{sub 2}. The Co cluster pathway is very favorable thermodynamically and kinetically for dehydrogenation. However, since CO binds strongly, it is likely to poison methanol decomposition to H{sub 2} and CO at low temperatures. In contrast, for the Cu cluster, CO poisoning is not likely to be a problem since it does not bind strongly, but the dehydrogenation steps are not energetically favorable. Pathways involving C-O bond cleavage are even less energetically favorable. The results are compared to our previous study of methanol decomposition on Pd{sub 4} and Pd{sub 8} clusters. Finally, all reaction energy changes and transition state energies, including those for the Pd clusters, are related in a linear, Broensted?Evans?Polanyi plot.

  18. Early stages of spinodal decomposition in Fe–Cr resolved by in-situ small-angle neutron scattering

    SciTech Connect (OSTI)

    Hörnqvist, M. Thuvander, M.; Steuwer, A.; King, S.; Odqvist, J.; Hedström, P.

    2015-02-09

    In-situ, time-resolved small-angle neutron scattering (SANS) investigations of the early stages of the spinodal decomposition process in Fe–35Cr were performed at 773 and 798 K. The kinetics of the decomposition, both in terms of characteristic distance and peak intensity, followed a power-law behaviour from the start of the heat treatment (a′{sup  }= 0.10–0.11 and a″ = 0.67–0.86). Furthermore, the method allows tracking of the high–Q slope, which is a sensitive measure of the early stages of decomposition. Ex-situ SANS and atom probe tomography were used to verify the results from the in-situ investigations. Finally, the in-situ measurement of the evolution of the characteristic distance at 773 K was compared with the predictions from the Cahn-Hilliard-Cook model, which showed good agreement with the experimental data (a′{sup  }= 0.12–0.20 depending on the assumed mobility)

  19. Thermal decomposition of 1,3,3-trinitroazetidine (TNAZ): A density functional theory and ab initio study

    SciTech Connect (OSTI)

    Veals, Jeffrey D.; Thompson, Donald L.

    2014-04-21

    Density functional theory and ab initio methods are employed to investigate decomposition pathways of 1,3,3-trinitroazetidine initiated by unimolecular loss of NO{sub 2} or HONO. Geometry optimizations are performed using M06/cc-pVTZ and coupled-cluster (CC) theory with single, double, and perturbative triple excitations, CCSD(T), is used to calculate accurate single-point energies for those geometries. The CCSD(T)/cc-pVTZ energies for NO{sub 2} elimination by NN and CN bond fission are, including zero-point energy (ZPE) corrections, 43.21 kcal/mol and 50.46 kcal/mol, respectively. The decomposition initiated by trans-HONO elimination can occur by a concerted H-atom and nitramine NO{sub 2} group elimination or by a concerted H-atom and nitroalkyl NO{sub 2} group elimination via barriers (at the CCSD(T)/cc-pVTZ level with ZPE corrections) of 47.00 kcal/mol and 48.27 kcal/mol, respectively. Thus, at the CCSD(T)/cc-pVTZ level, the ordering of these four decomposition steps from energetically most favored to least favored is: NO{sub 2} elimination by NN bond fission, HONO elimination involving the nitramine NO{sub 2} group, HONO elimination involving a nitroalkyl NO{sub 2} group, and finally NO{sub 2} elimination by CN bond fission.

  20. Succession of Phylogeny and Function During Plant Litter Decomposition (2013 DOE JGI Genomics of Energy and Environment 8th Annual User Meeting)

    SciTech Connect (OSTI)

    Brodie, Eoin

    2013-03-01

    Eoin Brodie of Berkeley Lab on "Succession of phylogeny and function during plant litter decomposition" at the 8th Annual Genomics of Energy & Environment Meeting on March 27, 2013 in Walnut Creek, Calif.

  1. Development of microbial-enzyme-mediated decomposition model parameters through steady-state and dynamic analyses

    SciTech Connect (OSTI)

    Wang, Gangsheng; Post, Wilfred M; Mayes, Melanie

    2013-01-01

    We developed a Microbial-ENzyme-mediated Decomposition (MEND) model, based on the Michaelis-Menten kinetics, that describes the dynamics of physically defined pools of soil organic matter (SOC). These include particulate, mineral-associated, dissolved organic matter (POC, MOC, and DOC, respectively), microbial biomass, and associated exoenzymes. The ranges and/or distributions of parameters were determined by both analytical steady-state and dynamic analyses with SOC data from the literature. We used an improved multi-objective parameter sensitivity analysis (MOPSA) to identify the most important parameters for the full model: maintenance of microbial biomass, turnover and synthesis of enzymes, and carbon use efficiency (CUE). The model predicted an increase of 2 C (baseline temperature =12 C) caused the pools of POC-Cellulose, MOC, and total SOC to increase with dynamic CUE and decrease with constant CUE, as indicated by the 50% confidence intervals. Regardless of dynamic or constant CUE, the pool sizes of POC, MOC, and total SOC varied from 8% to 8% under +2 C. The scenario analysis using a single parameter set indicates that higher temperature with dynamic CUE might result in greater net increases in both POC-Cellulose and MOC pools. Different dynamics of various SOC pools reflected the catalytic functions of specific enzymes targeting specific substrates and the interactions between microbes, enzymes, and SOC. With the feasible parameter values estimated in this study, models incorporating fundamental principles of microbial-enzyme dynamics can lead to simulation results qualitatively different from traditional models with fast/slow/passive pools.

  2. Decomposition Pathway of Ammonia Borane on the Surface of nano-BN

    SciTech Connect (OSTI)

    Neiner, Doinita; Luedtke, Avery T.; Karkamkar, Abhijeet J.; Shaw, Wendy J.; Wang, Julia; Browning, Nigel; Autrey, Thomas; Kauzlarich, Susan M.

    2010-08-19

    Ammonia borane (AB) is under significant investigation as a possible hydrogen storage material. While many chemical additives have been demonstrated to have a significant positive effect on hydrogen release from ammonia borane, many provide additional complications in the regeneration cycle. Mechanically alloyed hexagonal BN (nano-BN) has been shown to facilitate the release of hydrogen from AB at lower temperature, with minimal induction time, less exothermically, and inert nano-BN may be easily removed during any regeneration of the spent AB. The samples were prepared by mechanically alloying AB with nano-BN. Raman spectroscopy indicates that the AB:nano-BN samples are physical mixtures of AB and h-BN. The release of hydrogen from AB:nano-BN mixtures as well as the decomposition products were characterized by 11B magic angle spinning (MAS) solid state NMR, TGA/DSC/MS with 15N labeled AB, and solution 11B NMR spectroscopy. The 11B MAS solid state NMR spectrum shows that diammonate of diborane (DADB) is present in the mechanically alloyed mixture, which drastically shortens the induction period for hydrogen release from AB. Analysis of the TGA/DSC/MS spectra using 15N labeled AB shows that all the borazine (BZ) produced in the reaction comes from AB and that increasing nano-BN surface area results in increased amounts of BZ. However, under high temperature, 150?C, isothermal conditions, the amount of BZ released was the same as for neat AB. High resolution transmission electron microscopy (HRTEM), selected area diffraction (SAD), and electron energy loss spectroscopy (EELS) of the initial and final nano-BN additive provide evidence for crystallinity loss but not significant chemical changes. The higher concentration of BZ observed for low temperature dehydrogenation of AB:nano-BN mixtures versus neat AB is attributed to a surface interaction that favors the formation of precursors which ultimately result in BZ. This pathway can be avoided through isothermal heating at temperatures >150?C.

  3. ENERGY EFFICIENCY LIMITS FOR A RECUPERATIVE BAYONET SULFURIC ACID DECOMPOSITION REACTOR FOR SULFUR CYCLE THERMOCHEMICAL HYDROGEN PRODUCTION

    SciTech Connect (OSTI)

    Gorensek, M.; Edwards, T.

    2009-06-11

    A recuperative bayonet reactor design for the high-temperature sulfuric acid decomposition step in sulfur-based thermochemical hydrogen cycles was evaluated using pinch analysis in conjunction with statistical methods. The objective was to establish the minimum energy requirement. Taking hydrogen production via alkaline electrolysis with nuclear power as the benchmark, the acid decomposition step can consume no more than 450 kJ/mol SO{sub 2} for sulfur cycles to be competitive. The lowest value of the minimum heating target, 320.9 kJ/mol SO{sub 2}, was found at the highest pressure (90 bar) and peak process temperature (900 C) considered, and at a feed concentration of 42.5 mol% H{sub 2}SO{sub 4}. This should be low enough for a practical water-splitting process, even including the additional energy required to concentrate the acid feed. Lower temperatures consistently gave higher minimum heating targets. The lowest peak process temperature that could meet the 450-kJ/mol SO{sub 2} benchmark was 750 C. If the decomposition reactor were to be heated indirectly by an advanced gas-cooled reactor heat source (50 C temperature difference between primary and secondary coolants, 25 C minimum temperature difference between the secondary coolant and the process), then sulfur cycles using this concept could be competitive with alkaline electrolysis provided the primary heat source temperature is at least 825 C. The bayonet design will not be practical if the (primary heat source) reactor outlet temperature is below 825 C.

  4. Effect of moisture on leaf litter decomposition and its contribution to soil respiration in a temperate forest

    SciTech Connect (OSTI)

    Cisneros-Dozal, Luz Maria; Trumbore, Susan E.; Hanson, Paul J

    2007-01-01

    The degree to which increased soil respiration rates following wetting is caused by plant (autotrophic) versus microbial (heterotrophic) processes, is still largely uninvestigated. Incubation studies suggest microbial processes play a role but it remains unclear whether there is a stimulation of the microbial population as a whole or an increase in the importance of specific substrates that become available with wetting of the soil. We took advantage of an ongoing manipulation of leaf litter 14C contents at the Oak Ridge Reservation, Oak Ridge, Tennessee, to (1) determine the degree to which an increase in soil respiration rates that accompanied wetting of litter and soil, following a short period of drought, could be explained by heterotrophic contributions; and (2) investigate the potential causes of increased heterotrophic respiration in incubated litter and 0-5 cm mineral soil. The contribution of leaf litter decomposition increased from 6 3 mg C m 2 hr 1 during a transient drought, to 63 18 mg C m 2 hr 1 immediately after water addition, corresponding to an increase in the contribution to soil respiration from 5 2% to 37 8%. The increased relative contribution was sufficient to explain all of the observed increase in soil respiration for this one wetting event in the late growing season. Temperature (13 C versus 25 C) and moisture (dry versus field capacity) conditions did not change the relative contributions of different decomposition substrates in incubations, suggesting that more slowly cycling C has at least the same sensitivity to decomposition as faster cycling organic C at the temperature and moisture conditions studied.

  5. Synthesis of polycrystalline Co{sub 3}O{sub 4} nanowires with excellent ammonium perchlorate catalytic decomposition property

    SciTech Connect (OSTI)

    Zhou, Hai; Lv, Baoliang; Wu, Dong; Xu, Yao

    2014-12-15

    Graphical abstract: Co{sub 3}O{sub 4} nanowires with excellent ammonium perchlorate catalytic decomposition property were synthesized via a methanamide-assisted hydrolysis and subsequent dissolution–recrystallization process in the presence of methanamide. - Abstract: Co{sub 3}O{sub 4} nanowires, with the length of tens of micrometers and the width of several hundred nanometers, were produced by a hydrothermal treatment and a post-anneal process. X-ray diffraction (XRD) result showed that the Co{sub 3}O{sub 4} nanowires belong to cubic crystal system. Scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) analysis indicated that the Co{sub 3}O{sub 4} nanowires, composed by single crystalline nanoparticles, were of polycrystalline nature. On the basis of time-dependent experiments, methanamide-assisted hydrolysis and subsequent dissolution–recrystallization process were used to explain the precursors' formation process of the polycrystalline Co{sub 3}O{sub 4} nanowires. The TGA experiments showed that the as-obtained Co{sub 3}O{sub 4} nanowires can catalyze the thermal decomposition of ammonium perchlorate (AP) effectively.

  6. Thioozonide decomposition: sulfur and oxygen atom transfer. Evidence for the formation of a carbonyl O-sulfide intermediate

    SciTech Connect (OSTI)

    Matturro, M.G.; Reynolds, R.P.; Kastrup, R.V.; Pictroski, C.F.

    1986-05-14

    The chemistry of ozonides is of considerable interest from a practical and theoretical viewpoint. Thioozonide 1, formally the monosulfur-substituted ozonide of dimethylcyclobutadiene, has been proposed as an intermediate in the room temperature photooxidation of 2,5-dimethylthiophene. Subsequent low-temperature studies confirmed this structural assignment. When 1 is allowed to warm to room temperature, it rearranges to a mixture of sulfine 2 and cis- and trans-3-hexene-2,5-diones (3c and 3t). Recent examination of the thermal decomposition of 1 has led to a proposed mechanism involving a carbonyl sulfide 4 as an intermediate along the sulfur expulsion pathway to 3c; however, no experimental support for this hypothesis was given. Carbonyl O-sulfides have also been implicated as intermediates from the photolysis of oxathiiranes. The authors report evidence for the formation of 4 during the decomposition of 1 and that elemental sulfur (S/sub 8/) is formed during the reaction by concatenation of sulfur atoms or fragments (S/sub 2/, S/sub 3/, etc.).

  7. Identifying the Oil Price-Macroeconomy Relationship: An Empirical Mode Decomposition Analysis of U.S. Data

    SciTech Connect (OSTI)

    Oladosu, Gbadebo A

    2009-01-01

    This work applies the empirical mode decomposition (EMD) method to data on real quarterly oil price (West Texas Intermediate - WTI) and U.S. gross domestic product (GDP). This relatively new method is adaptive and capable of handling non-linear and non-stationary data. Correlation analysis of the decomposition results was performed and examined for insights into the oil-macroeconomy relationship. Several components of this relationship were identified. However, the principal one is that the medium-run cyclical component of the oil price exerts a negative and exogenous influence on the main cyclical component of the GDP. This can be interpreted as the supply-driven or supply-shock component of the oil price-GDP relationship. In addition, weak correlations suggesting a lagging demand-driven, an expectations-driven, and a long-run supply-driven component of the relationship were also identified. Comparisons of these findings with significant oil supply disruption and recession dates were supportive. The study identified a number of lessons applicable to recent oil market events, including the eventuality of persistent economic and price declines following a long oil price run-up. In addition, it was found that oil-market related exogenous events are associated with short- to medium-run price implications regardless of whether they lead to actual supply disruptions.

  8. A domain decomposition method of stochastic PDEs: An iterative solution techniques using a two-level scalable preconditioner

    SciTech Connect (OSTI)

    Subber, Waad Sarkar, Abhijit

    2014-01-15

    Recent advances in high performance computing systems and sensing technologies motivate computational simulations with extremely high resolution models with capabilities to quantify uncertainties for credible numerical predictions. A two-level domain decomposition method is reported in this investigation to devise a linear solver for the large-scale system in the Galerkin spectral stochastic finite element method (SSFEM). In particular, a two-level scalable preconditioner is introduced in order to iteratively solve the large-scale linear system in the intrusive SSFEM using an iterative substructuring based domain decomposition solver. The implementation of the algorithm involves solving a local problem on each subdomain that constructs the local part of the preconditioner and a coarse problem that propagates information globally among the subdomains. The numerical and parallel scalabilities of the two-level preconditioner are contrasted with the previously developed one-level preconditioner for two-dimensional flow through porous media and elasticity problems with spatially varying non-Gaussian material properties. A distributed implementation of the parallel algorithm is carried out using MPI and PETSc parallel libraries. The scalabilities of the algorithm are investigated in a Linux cluster.

  9. Shock tube and theoretical studies on the thermal decomposition of propane : evidence for a roaming radical channel.

    SciTech Connect (OSTI)

    Sivaramakrishnan, R.; Su, M.-C.; Michael, J. V.; Klippenstein, S. J.; Harding, L. B.; Ruscic, B.

    2011-04-21

    The thermal decomposition of propane has been studied using both shock tube experiments and ab initio transition state theory-based master equation calculations. Dissociation rate constants for propane have been measured at high temperatures behind reflected shock waves using high-sensitivity H-ARAS detection and CH{sub 3} optical absorption. The two major dissociation channels at high temperature are C{sub 3}H{sub 8} {yields} CH{sub 3} + C{sub 2}H{sub 5} (eq 1a) and C{sub 3}H{sub 8} {yields} CH{sub 4} + C{sub 2}H{sub 4} (eq 1b). Ultra high-sensitivity ARAS detection of H-atoms produced from the decomposition of the product, C{sub 2}H{sub 5}, in (1a), allowed measurements of both the total decomposition rate constants, k{sub total}, and the branching to radical products, k{sub 1a}/k{sub total}. Theoretical analyses indicate that the molecular products are formed exclusively through the roaming radical mechanism and that radical products are formed exclusively through channel 1a. The experiments were performed over the temperature range 1417-1819 K and gave a minor contribution of (10 {+-} 8%) due to roaming. A multipass CH{sub 3} absorption diagnostic using a Zn resonance lamp was also developed and characterized in this work using the thermal decomposition of CH{sub 3}I as a reference reaction. The measured rate constants for CH{sub 3}I decomposition agreed with earlier determinations from this laboratory that were based on I-atom ARAS measurements. This CH{sub 3} diagnostic was then used to detect radicals from channel 1a allowing lower temperature (1202-1543 K) measurements of k1a to be determined. Variable reaction coordinate-transition state theory was used to predict the high pressure limits for channel (1a) and other bond fission reactions in C{sub 3}H{sub 8}. Conventional transition state theory calculations were also used to estimate rate constants for other tight transition state processes. These calculations predict a negligible contribution (<1%) from all other bond fission and tight transition state processes, indicating that the bond fission channel (1a) and the roaming channel (1b) are indeed the only active channels at the temperature and pressure ranges of the present experiments. The predicted reaction exo- and endothermicities are in excellent agreement with the current version of the Active Thermochemical Tables. Master equation calculations incorporating these transition state theory results yield predictions for the temperature and pressure dependence of the dissociation rate constants for channel 1a. The final theoretical results reliably reproduce the measured dissociation rate constants that are reported here and in the literature. The experimental data are well reproduced over the 500-2500 K and 1 x 10{sup -4} to 100 bar range (errors of {approx}15% or less) by the following Troe parameters for Ar as the bath gas: k{sub {infinity}} = 1.55 x 10{sup 24}T{sup -2.034} exp(-45490/T) s{sup -1}, k{sub 0} = 7.92 x 10{sup 53}T{sup -16.67} exp(-50380/T) cm{sup 3} s{sup -1}, and F{sub c} = 0.190 exp(-T/3091) + 0.810 exp(-T/128) + exp(-8829/T).

  10. Properties of soil pore space regulate pathways of plant residue decomposition and community structure of associated bacteria

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

    Negassa, Wakene C.; Guber, Andrey K.; Kravchenko, Alexandra N.; Marsh, Terence L.; Hildebrandt, Britton; Rivers, Mark L.

    2015-07-01

    Physical protection of soil carbon (C) is one of the important components of C storage. However, its exact mechanisms are still not sufficiently lucid. The goal of this study was to explore the influence of soil structure, that is, soil pore spatial arrangements, with and without presence of plant residue on (i) decomposition of added plant residue, (ii) CO₂ emission from soil, and (iii) structure of soil bacterial communities. The study consisted of several soil incubation experiments with samples of contrasting pore characteristics with/without plant residue, accompanied by X-ray micro-tomographic analyses of soil pores and by microbial community analysis ofmore » amplified 16S–18S rRNA genes via pyrosequencing. We observed that in the samples with substantial presence of air-filled well-connected large (>30 µm) pores, 75–80% of the added plant residue was decomposed, cumulative CO₂ emission constituted 1,200 µm C g⁻¹ soil, and movement of C from decomposing plant residue into adjacent soil was insignificant. In the samples with greater abundance of water-filled small pores, 60% of the added plant residue was decomposed, cumulative CO₂ emission constituted 2,000 µm C g⁻¹ soil, and the movement of residue C into adjacent soil was substantial. In the absence of plant residue the influence of pore characteristics on CO₂ emission, that is on decomposition of the native soil organic C, was negligible. The microbial communities on the plant residue in the samples with large pores had more microbial groups known to be cellulose decomposers, that is, Bacteroidetes, Proteobacteria, Actinobacteria, and Firmicutes, while a number of oligotrophic Acidobacteria groups were more abundant on the plant residue from the samples with small pores. This study provides the first experimental evidence that characteristics of soil pores and their air/water flow status determine the phylogenetic composition of the local microbial community and directions and magnitudes of soil C decomposition processes.« less

  11. A full-spectral Bayesian reconstruction approach based on the material decomposition model applied in dual-energy computed tomography

    SciTech Connect (OSTI)

    Cai, C.; Rodet, T.; Mohammad-Djafari, A.; Legoupil, S.

    2013-11-15

    Purpose: Dual-energy computed tomography (DECT) makes it possible to get two fractions of basis materials without segmentation. One is the soft-tissue equivalent water fraction and the other is the hard-matter equivalent bone fraction. Practical DECT measurements are usually obtained with polychromatic x-ray beams. Existing reconstruction approaches based on linear forward models without counting the beam polychromaticity fail to estimate the correct decomposition fractions and result in beam-hardening artifacts (BHA). The existing BHA correction approaches either need to refer to calibration measurements or suffer from the noise amplification caused by the negative-log preprocessing and the ill-conditioned water and bone separation problem. To overcome these problems, statistical DECT reconstruction approaches based on nonlinear forward models counting the beam polychromaticity show great potential for giving accurate fraction images.Methods: This work proposes a full-spectral Bayesian reconstruction approach which allows the reconstruction of high quality fraction images from ordinary polychromatic measurements. This approach is based on a Gaussian noise model with unknown variance assigned directly to the projections without taking negative-log. Referring to Bayesian inferences, the decomposition fractions and observation variance are estimated by using the joint maximum a posteriori (MAP) estimation method. Subject to an adaptive prior model assigned to the variance, the joint estimation problem is then simplified into a single estimation problem. It transforms the joint MAP estimation problem into a minimization problem with a nonquadratic cost function. To solve it, the use of a monotone conjugate gradient algorithm with suboptimal descent steps is proposed.Results: The performance of the proposed approach is analyzed with both simulated and experimental data. The results show that the proposed Bayesian approach is robust to noise and materials. It is also necessary to have the accurate spectrum information about the source-detector system. When dealing with experimental data, the spectrum can be predicted by a Monte Carlo simulator. For the materials between water and bone, less than 5% separation errors are observed on the estimated decomposition fractions.Conclusions: The proposed approach is a statistical reconstruction approach based on a nonlinear forward model counting the full beam polychromaticity and applied directly to the projections without taking negative-log. Compared to the approaches based on linear forward models and the BHA correction approaches, it has advantages in noise robustness and reconstruction accuracy.

  12. Thermal decomposition of Mg/V hydrotalcites and catalytic performance of the products in oxidative dehydrogenation reactions

    SciTech Connect (OSTI)

    Holgado, M.J.; Labajos, F.M.; Montero, M.J.S.; Rives, V

    2003-11-26

    Layered double hydroxides with the hydrotalcite-type structure containing Mg{sup 2+} and V{sup 3+} in the brucite-like layers, possessing different V contents, have been prepared and characterised by elemental chemical analysis, powder X-ray diffraction, Fourier transform infrared (FT-IR) spectroscopy and specific surface area and porosity assessment by nitrogen adsorption; thermal decomposition was studied by Differential Thermal Analysis and Thermogravimetric Analysis. The solids obtained after calcination at 800 deg. C were tested as catalysts for oxidative dehydrogenation of propane and n-butane. Results indicate that the relative amounts of Mg{sub 3}(VO{sub 4}) and MgO, depending on the V content in the starting hydrotalcite, determines the performance of the catalysts in oxidative dehydrogenation of propane and n-butane.

  13. MHD Structure Analysis by Singular Value Decomposition as a Tool for ECRH RT-Control of Instabilities on FTU

    SciTech Connect (OSTI)

    Marchetto, C.; Cirant, S.; Granucci, G.; Lazzaro, E.; Gandini, F.; Esposito, B.

    2009-11-26

    In this work we present the results obtained applying Singular Value Decomposition (SVD) on a Mirnov coil array in FTU discharges where experiments on MHD stabilization or disruption avoidance via ECRH were performed. In these shots the mode analysis has been consolidated off line by means of FFT and SXR-tomography. Although the Mirnov setting was not necessarily optimised, results show that the algorithm based on SVD is able to detect the mode with a precision equal or better than the FFT, while acting on a smaller time interval. The short execution time required, even in the present preliminary form, suggests that this analysis can be a suitable tool to be implemented in a real time control chain.

  14. System and methods for determining masking signals for applying empirical mode decomposition (EMD) and for demodulating intrinsic mode functions obtained from application of EMD

    DOE Patents [OSTI]

    Senroy, Nilanjan; Suryanarayanan, Siddharth

    2011-03-15

    A computer-implemented method of signal processing is provided. The method includes generating one or more masking signals based upon a computed Fourier transform of a received signal. The method further includes determining one or more intrinsic mode functions (IMFs) of the received signal by performing a masking-signal-based empirical mode decomposition (EMD) using the at least one masking signal.

  15. Silver-mordenite for radiologic gas capture from complex streams. Dual catalytic CH3I decomposition and I confinement

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

    Nenoff, Tina M.; Rodriguez, Mark A.; Soelberg, Nick R.; Chapman, Karena W.

    2014-05-09

    The selective capture of radiological iodine (129I) is a persistent concern for safe nuclear energy. In these nuclear fuel reprocessing scenarios, the gas streams to be treated are extremely complex, containing several distinct iodine-containing molecules amongst a large variety of other species. Silver-containing mordenite (MOR) is a longstanding benchmark for radioiodine capture, reacting with molecular iodine (I2) to form AgI. However the mechanisms for organoiodine capture is not well understood. Here we investigate the capture of methyl iodide from complex mixed gas streams by combining chemical analysis of the effluent gas stream with in depth characterization of the recovered sorbent.more » Tools applied include infrared spectroscopy, thermogravimetric analysis with mass spectrometry, micro X-ray fluorescence, powder X-ray diffraction analysis, and pair distribution function analysis. Moreover, the MOR zeolite catalyzes decomposition of the methyl iodide through formation of surface methoxy species (SMS), which subsequently reacts with water in the mixed gas stream to form methanol, and with methanol to form dimethyl ether, which are both detected downstream in the effluent. The liberated iodine reacts with Ag in the MOR pore to the form subnanometer AgI clusters, smaller than the MOR pores, suggesting that the iodine is both physically and chemically confined within the zeolite.« less

  16. Blip decomposition of the path integral: Exponential acceleration of real-time calculations on quantum dissipative systems

    SciTech Connect (OSTI)

    Makri, Nancy

    2014-10-07

    The real-time path integral representation of the reduced density matrix for a discrete system in contact with a dissipative medium is rewritten in terms of the number of blips, i.e., elementary time intervals over which the forward and backward paths are not identical. For a given set of blips, it is shown that the path sum with respect to the coordinates of all remaining time points is isomorphic to that for the wavefunction of a system subject to an external driving term and thus can be summed by an inexpensive iterative procedure. This exact decomposition reduces the number of terms by a factor that increases exponentially with propagation time. Further, under conditions (moderately high temperature and/or dissipation strength) that lead primarily to incoherent dynamics, the “fully incoherent limit” zero-blip term of the series provides a reasonable approximation to the dynamics, and the blip series converges rapidly to the exact result. Retention of only the blips required for satisfactory convergence leads to speedup of full-memory path integral calculations by many orders of magnitude.

  17. Spontaneous formation of nanostructures by surface spinodal decomposition in GaAs{sub 1?x}Bi{sub x} epilayers

    SciTech Connect (OSTI)

    Luna, E. Wu, M.; Trampert, A.; Puustinen, J.; Guina, M.

    2015-05-14

    We report on the spontaneous formation of lateral composition modulations (LCMs) in Ga(As,Bi) epilayers grown by low-temperature (<300?C) molecular beam epitaxy (MBE) on GaAs(001). Both cross-section and plan-view transmission electron microscopy techniques are used to investigate the nature of the LCMs, consisting of Bi-rich cylinder-like nanostructures lying along the [001] growth direction. The observed LCMs are the consequence of a two-dimensional phase separation process occurring at the surface of the growing epilayers, and their columnar nature is consistent with a surface-directed spinodal decomposition process. Although LCMs are thermodynamically driven, we show how they can be kinetically controlled, in particular, through the As/Ga flux ratio and the substrate temperature. This is a result of LCMs developing from surface atomic diffusion processes, since the atomic dimer configurations on the surface alter adatom diffusivity. The significant role of the surface reconstructions is also discussed.

  18. Mass-radius relations and core-envelope decompositions of super-Earths and sub-Neptunes

    SciTech Connect (OSTI)

    Howe, Alex R.; Burrows, Adam; Verne, Wesley E-mail: burrows@astro.princeton.edu

    2014-06-01

    Many exoplanets have been discovered with radii of 1-4 R {sub ?}, between that of Earth and Neptune. A number of these are known to have densities consistent with solid compositions, while others are 'sub-Neptunes' likely to have significant H{sub 2}-He envelopes. Future surveys will no doubt significantly expand these populations. In order to understand how the measured masses and radii of such planets can inform their structures and compositions, we construct models both for solid layered planets and for planets with solid cores and gaseous envelopes, exploring a range of core masses, H{sub 2}-He envelope masses, and associated envelope entropies. For planets in the super-Earth/sub-Neptune regime for which both radius and mass are measured, we estimate how each is partitioned into a solid core and gaseous envelope, associating a specific core mass and envelope mass with a given exoplanet. We perform this decomposition for both ''Earth-like'' rock-iron cores and pure ice cores, and find that the necessary gaseous envelope masses for this important sub-class of exoplanets must range very widely from zero to many Earth masses, even for a given core mass. This result bears importantly on exoplanet formation and envelope evaporation processes.

  19. Spectroscopic study of reaction intermediates and mechanisms in nitramine decomposition and combustion. Final report, 20 March 1992-19 March 1995

    SciTech Connect (OSTI)

    Jacox, M.B.

    1995-05-20

    The infrared spectra of reaction intermediates trapped in solid neon were studied in order to support the development of diagnostics for short-lived species which are reaction carriers in nitramine decomposition and combustion and to derive information about reactions which are important in the condensed-phase decomposition of nitramines. Nitromethane and monomethylnitramine were used as model compounds in these studies. Evidence was obtained for the formation of water complexes with both of these species. The results support the water-catalyzed decomposition mechanism for nitramines that was proposed by Melius. Studies of the photodecomposition of isotopically substituted monomethylnitramine demonstrate that four different groups of products are formed. Tentative spectral assignments are made for the aci-isomer of monomethylnitramine and for CH3NHONO. The final photodecomposition products are CH4, NO, CH3OH, and N20. Other studies have provided evidence for the formation of a weakly bonded complex of H2 with H20, as well as spectral data for the HCC free radical and for the H20+, N02+, NO(2-), and NO(3-), molecular ions.

  20. Energy savings and structural changes in the U.S. economy: Evidence from disaggregated data using decomposition techniques

    SciTech Connect (OSTI)

    Murtishaw, Scott; Schipper, Lee

    2001-12-01

    During the period 1973 to 1985, the U.S. economy saved energy in virtually every sector. Much of this period of energy saving was also marked by a significant drop in the ratio of energy use to GDP. However, since 1985 there has been a slowdown in the rate of energy saving, as key energy intensities (space heating, automobile driving, etc.) have declined less rapidly since 1985 than before. This paper examines delivered (or final) energy consumption trends from the early 1970s to 1994 and provides a framework for measuring key changes that affect U.S. energy use. Starting with estimates of outputs or activity levels for thirty major energy end uses, and energy intensities of each end use, we use the Adaptive Weighted Divisia decomposition to measure the impact of changes in the structure of the U.S. economy. In contrast to many similar decomposition studies, we define measures of structural changes for both households and branches of transportation. We find that between 1973 and 1985, lower energy intensities (corrected to average winter heating demand) reduced U.S. energy uses by about 1.7% per year, while structural changes reduced energy uses by 0.4% per year. After 1985, when oil prices declined markedly, intensities fell by only 0.8% per year and structural changes actually increased energy use by 0.4% per year. In the 1990s energy intensities in some industries have even edged upward. Changes in the ratio of energy to GDP (E/GDP) are affected both by intensities and the changes in the demand for energy services relative to GDP. During the first period, from 1973 to 1985, GDP increased faster than the growth in key structural and activity parameters that determine demand for energy services (such as home area, appliance ownership, and motor vehicle use) by 1.5% per year. From 1985 to 1994 the difference dropped to less than 0.3% per year, largely due to the reversal of structural trends. Thus, the sharp fall in the rate of decline in E/GDP from -3.1% to -1.1% per year was due almost as much to structural changes as it was to the slowdown in energy intensity reduction. The analysis presented here shows why the E/GDP is an increasingly unreliable yardstick for making measurements of how the energy-economy relationship is changing: effects not related to energy efficiency per se may have roughly the same impact on that ratio as energy saving itself. Since these effects have different causes, and potentially different impacts over the long run, looking at them in the aggregate by considering only the ratio of energy use to GDP is misleading.

  1. Decomposition and vibrational relaxation in CH{sub 3}I and self-reaction of CH{sub 3} radicals.

    SciTech Connect (OSTI)

    Yang, X.; Goldsmith, C. F.; Tranter, R. S.

    2009-07-01

    Vibrational relaxation and dissociation of CH{sub 3}I, 2-20% in krypton, have been investigated behind incident shock waves in a diaphragmless shock tube at 20, 66, 148, and 280 Torr and 630-2200 K by laser schlieren densitometry. The effective collision energy obtained from the vibrational relaxation experiments has a small, positive temperature dependence, {Delta}E{sub down} = 63 x (T/298){sup 0.56} cm{sup -1}. First-order rate coefficients for dissociation of CH{sub 3}I show a strong pressure dependence and are close to the low-pressure limit. Restricted-rotor Gorin model RRKM calculations fit the experimental results very well with {Delta}E{sub down} = 378 x (T/298){sup 0.457} cm{sup -1}. The secondary chemistry of this reaction system is dominated by reactions of methyl radicals and the reaction of the H atom with CH{sub 3}I. The results of the decomposition experiments are very well simulated with a model that incorporates methyl recombination and reactions of methylene. Second-order rate coefficients for ethane dissociation to two methyl radicals were derived from the experiments and yield k = (4.50 {+-} 0.50) x 10{sup 17} exp(-32709/T) cm{sup 3} mol{sup -1} s{sup -1}, in good agreement with previous measurements. Rate coefficients for H + CH{sub 3}I were also obtained and give k = (7.50 {+-} 1.0) x 10{sup 13} exp(-601/T) cm{sup 3} mol{sup -1} s{sup -1}, in reasonable agreement with a previous experimental value.

  2. Synthesis and characterization of ZnO and Ni doped ZnO nanorods by thermal decomposition method for spintronics application

    SciTech Connect (OSTI)

    Saravanan, R.; Santhi, Kalavathy; Sivakumar, N.; Narayanan, V.; Stephen, A.

    2012-05-15

    Zinc oxide nanorods and diluted magnetic semiconducting Ni doped ZnO nanorods were prepared by thermal decomposition method. This method is simple and cost effective. The decomposition temperature of acetate and formation of oxide were determined by TGA before the actual synthesis process. The X-ray diffraction result indicates the single phase hexagonal structure of zinc oxide. The transmission electron microscopy and scanning electron microscopy images show rod like structure of ZnO and Ni doped ZnO samples with the diameter {approx} 35 nm and the length in few micrometers. The surface analysis was performed using X-ray photoelectron spectroscopic studies. The Ni doped ZnO exhibits room temperature ferromagnetism. This diluted magnetic semiconducting Ni doped ZnO nanorods finds its application in spintronics. - Highlights: Black-Right-Pointing-Pointer The method used is very simple and cost effective compared to all other methods for the preparation DMS materials. Black-Right-Pointing-Pointer ZnO and Ni doped ZnO nanorods Black-Right-Pointing-Pointer Ferromagnetism at room temperature.

  3. The thermal decomposition of NH{sub 2}OH and subsequent reactions : ab initio transition state theory and reflected shock tube experiments.

    SciTech Connect (OSTI)

    Klippenstein, S. J.; Harding, L. B.; Ruscic, B.; Sivaramakrishnan, R.; Srinivasan, N. K.; Su, M.-C.; Michael, J. V.; Chemical Sciences and Engineering Division; Sonoma State Univ.

    2009-01-01

    Primary and secondary reactions involved in the thermal decomposition of NH{sub 2}OH are studied with a combination of shock tube experiments and transition state theory based theoretical kinetics. This coupled theory and experiment study demonstrates the utility of NH{sub 2}OH as a high temperature source of OH radicals. The reflected shock technique is employed in the determination of OH radical time profiles via multipass electronic absorption spectrometry. O-atoms are searched for with atomic resonance absorption spectrometry. The experiments provide a direct measurement of the rate coefficient, k{sub 1}, for the thermal decomposition of NH{sub 2}OH. Secondary rate measurements are obtained for the NH{sub 2} + OH (5a) and NH{sub 2}OH + OH (6a) abstraction reactions. The experimental data are obtained for temperatures in the range from 1355 to 1889 K and are well represented by the respective rate expressions: log[k/(cm{sup 3} molecule{sup -1} s{sup -1})] = (?10.12 {+-} 0.20) + (?6793 {+-} 317 K/T) (k{sub 1}); log[k/(cm{sup 3} molecule{sup -1} s{sup -1})] = (?10.00 {+-} 0.06) + (?879 {+-} 101 K/T) (k{sub 5a}); log[k/(cm{sup 3} molecule{sup -1} s{sup -1})] = (?9.75 {+-} 0.08) + (?1248 {+-} 123 K/T) (k{sub 6a}). Theoretical predictions are made for these rate coefficients as well for the reactions of NH{sub 2}OH + NH{sub 2}, NH{sub 2}OH + NH, NH + OH, NH{sub 2} + NH{sub 2}, NH{sub 2} + NH, and NH + NH, each of which could be of secondary importance in NH{sub 2}OH thermal decomposition. The theoretical analyses employ a combination of ab initio transition state theory and master equation simulations. Comparisons between theory and experiment are made where possible. Modest adjustments of predicted barrier heights (i.e., by 2 kcal/mol or less) generally yield good agreement between theory and experiment. The rate coefficients obtained here should be of utility in modeling NO{sub x} in various combustion environments.

  4. Effect of internal noise on the oscillation of N{sub 2}O decomposition over Cu-ZSM-5 zeolites using a stochastic description

    SciTech Connect (OSTI)

    Liu, Fuliang; Li, Yaping Sun, Xiaoming

    2014-01-28

    When considering stochastic oscillations of heterogeneous catalyst systems, most researches have focused on the surface of a metal or its oxide catalysts, but there have been few studies on porous catalysts. In this work, the effects of internal noise on oscillations of N{sub 2}O decomposition over Cu-ZSM-5 zeolites are investigated, using the chemical Langevin equation and a mesoscopic stochastic model. Considering that Cu-ZSM-5 particles are finely divided particles, the number of Cu ions (N{sub s}) is proportional to the particle size at a certain Cu/Al, and the internal noise is inversely proportional to N{sub s}. Stochastic oscillations can be observed outside the deterministic oscillatory region. Furthermore, the performance of the oscillation characterized by the signal-to-noise ratio has a maximum within the optimal size range of 48 nm. This suggests that a nanometer-sized zeolite may be best for oscillations.

  5. Investigation of the Decomposition Mechanism of Lithium Bis(oxalate)borate (LiBOB) Salt in the Electrolyte of an Aprotic LiO2 Battery

    SciTech Connect (OSTI)

    Lau, Kah Chun; Lu, Jun; Low, John; Peng, Du; Wu, Huiming; Albishri, Hassan M.; Al-Hady, D. Abd; Curtiss, Larry A.; Amine, Khalil

    2014-04-01

    The stability of the lithium bis(oxalate) borate (LiBOB) salt against lithium peroxide (Li2O2) formation in an aprotic LiO2 (Liair) battery is investigated. From theoretical and experimental findings, we find that the chemical decomposition of LiBOB in electrolytes leads to the formation lithium oxalate during the discharge of a LiO2 cell. According to density functional theory (DFT) calculations, the formation of lithium oxalate as the reaction product is exothermic and therefore is thermodynamically feasible. This reaction seems to be independent of solvents used in the LiO2 cell, and therefore LiBOB is probably not suitable to be used as the salt in LiO2 cell electrolytes.

  6. Rate constants for the thermal decomposition of ethanol and its bimolecular reactions with OH and D : reflected shock tube and theoretical studies.

    SciTech Connect (OSTI)

    Sivaramakrishnan, R.; Su, M.-C.; Michael, J. V.; Klippenstein, S. J.; Harding, L. B.; Ruscic, B.

    2010-09-09

    The thermal decomposition of ethanol and its reactions with OH and D have been studied with both shock tube experiments and ab initio transition state theory-based master equation calculations. Dissociation rate constants for ethanol have been measured at high T in reflected shock waves using OH optical absorption and high-sensitivity H-atom ARAS detection. The three dissociation processes that are dominant at high T are: C{sub 2}H{sub 5}OH {yields} C{sub 2}H{sub 4} + H{sub 2}O; C{sub 2}H{sub 5}OH {yields} CH{sub 3} + CH{sub 2}OH; C{sub 2}H{sub 5}OH {yields} C{sub 2}H{sub 5} + OH. The rate coefficient for reaction C was measured directly with high sensitivity at 308 nm using a multipass optical White cell. Meanwhile, H-atom ARAS measurements yield the overall rate coefficient and that for the sum of reactions B and C, since H-atoms are instantaneously formed from the decompositions of CH{sub 2}OH and C{sub 2}H{sub 5} into CH{sub 2}O + H and C{sub 2}H{sub 4} + H, respectively. By difference, rate constants for reaction 1 could be obtained. One potential complication is the scavenging of OH by unreacted ethanol in the OH experiments, and therefore, rate constants for OH + C{sub 2}H{sub 5}OH {yields} products were measured using tert-butyl hydroperoxide (tBH) as the thermal source for OH. The present experiments can be represented by the Arrhenius expression k = (2.5 {+-} 0.43) x 10{sup -11} exp(- 911 {+-} 191 K/T) cm{sup 3} molecule{sup -1} s{sup -1} over the T range 857-1297 K. For completeness, we have also measured the rate coefficient for the reaction of D atoms with ethanol D + C{sub 2}H{sub 5}OH {yields} products whose H analogue is another key reaction in the combustion of ethanol. Over the T range 1054-1359 K, the rate constants from the present experiments can be represented by the Arrhenius expression, k = (3.98 {+-} 0.76) x 10{sup -10} exp(- 4494 {+-} 235 K/T) cm{sup 3} molecule{sup -1} s{sup -1}. The high-pressure rate coefficients for reactions B and C were studied with variable reaction coordinate transition state theory employing directly determined CASPT2/cc-pvdz interaction energies. Reactions A, D, and E were studied with conventional transition state theory employing QCISD(T)/CBS energies. For the saddle point in reaction A, additional high-level corrections are evaluated. The predicted reaction exo- and endothermicities are in good agreement with the current Active Thermochemical Tables values. The transition state theory predictions for the microcanonical rate coefficients in ethanol decomposition are incorporated in master equation calculations to yield predictions for the temperature and pressure dependences of reactions A-C. With modest adjustments (<1 kcal/mol) to a few key barrier heights, the present experimental and adjusted theoretical results yield a consistent description of both the decomposition (1-3) and abstraction kinetics (4 and 5). The present results are compared with earlier experimental and theoretical work.

  7. Meso/macroporous {gamma}-Al{sub 2}O{sub 3} fabricated by thermal decomposition of nanorods ammonium aluminium carbonate hydroxide

    SciTech Connect (OSTI)

    Li, Guang-Ci; Liu, Yun-Qi; Guan, Li-Li; Hu, Xiao-Fu; Liu, Chen-Guang

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer Rod-like AACH were synthesized by a hydrothermal treatment. Black-Right-Pointing-Pointer AACH was formed via a Al(OH){sub 3} {yields} (NH{sub 4}){sub 2}Al{sub 6}(CO{sub 3}){sub 3}(OH){sub 14}{center_dot}xH{sub 2}O {yields} NH{sub 4}Al(OH){sub 2}CO{sub 3}{center_dot}H{sub 2}O {yields} NH{sub 4}Al(OH){sub 2}CO{sub 3} path. Black-Right-Pointing-Pointer Alumina derived from AACH has a good thermal stability. Black-Right-Pointing-Pointer The obtained alumina possesses large pore volume and bimodal porosity. -- Abstract: Through exploring the reaction parameters during the synthesis of the AACH, rod-like ammonium aluminium carbonate hydroxide (AACH) with high crystallinity has been successfully prepared via a facile hydrothermal method. The synthesis parameters like time, the molar ratio of NH{sub 4}HCO{sub 3}/Al and the properties of starting materials were systematically investigated. The structure was characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), IR and transmission electron microscopy (TEM). The experimental results display that the obtained {gamma}-Al{sub 2}O{sub 3} materials possess meso/macroporosity and large pore volume, which are mainly attributed to the removal of gas molecules during the decomposition of AACH. Moreover, using the rod-like AACH as precursor, {gamma}-Al{sub 2}O{sub 3} nanorods were obtained via a low-temperature thermal decomposition method.

  8. The role of adsorption in decomposition of dyes on TiO{sub 2} and N-modified TiO{sub 2} photocatalysts under UV and visible light irradiations

    SciTech Connect (OSTI)

    Bubacz, Kamila; Tryba, Beata; Morawski, Antoni W.

    2012-11-15

    Graphical abstract: Influence of pH and zeta potential of TiO{sub 2} based photocatalysts on the adsorption and degradation of MB under UV irradiation. Highlights: ? Adsorption of dyes on TiO{sub 2}/N accelerated their decomposition under visible light. ? pH of solution and the PZC of the TiO{sub 2} surface influence the adsorption of dyes. ? Under UV irradiation oxidation of pollutants with OH radicals is the most powerful. -- Abstract: Photoactivities of TiO{sub 2} based photocatalysts towards dyes decomposition was studied by consider their adsorption abilities. It was proved that zeta potential and PZC (point zero charge) of photocatalyst surface as well as pH of solution strongly influenced adsorption of tested dyes, Methylene Blue (MB) and Reactive Red 198 (RR198). These dyes underwent the photocatalytic decomposition by two ways, OH radicals attack and direct oxidation with photogenerated holes. The latter one is more efficient in case of better contact of pollutant with the photocatalysts surface and is dominant under visible light irradiation, where insignificant amount of OH radicals is formed. The former one is powerful under UV irradiation and is a key factor in decomposition of dyes regardless of their adsorption abilities.

  9. Methanol Decomposition over Palladium Particles Supported on Silica: Role of Particle Size and Co-Feeding Carbon Dioxide on the Catalytic Properties

    SciTech Connect (OSTI)

    Hokenek, Selma; Kuhn, John N. (USF)

    2012-10-23

    Monodisperse palladium particles of six distinct and controlled sizes between 4-16 nm were synthesized in a one-pot polyol process by varying the molar ratios of the two palladium precursors used, which contained palladium in different oxidation states. This difference permitted size control by regulation of the nucleation rate because low oxidation state metals ions nucleate quickly relative to high oxidation state ions. After immobilization of the Pd particles on silica by mild sonication, the catalysts were characterized by X-ray absorption spectroscopy and applied toward catalytic methanol decomposition. This reaction was determined as structure sensitive with the intrinsic activity (turnover frequency) increasing with increasing particle size. Moreover, observed catalytic deactivation was linked to product (carbon monoxide) poisoning. Co-feeding carbon dioxide caused the activity and the amount of deactivation to decrease substantially. A reaction mechanism based on the formation of the {pi}-bond between carbon and oxygen as the rate-limiting step is in agreement with antipathetic structure sensitivity and product poisoning by carbon monoxide.

  10. Silver-mordenite for radiologic gas capture from complex streams. Dual catalytic CH3I decomposition and I confinement

    SciTech Connect (OSTI)

    Nenoff, Tina M.; Rodriguez, Mark A.; Soelberg, Nick R.; Chapman, Karena W.

    2014-05-09

    The selective capture of radiological iodine (129I) is a persistent concern for safe nuclear energy. In these nuclear fuel reprocessing scenarios, the gas streams to be treated are extremely complex, containing several distinct iodine-containing molecules amongst a large variety of other species. Silver-containing mordenite (MOR) is a longstanding benchmark for radioiodine capture, reacting with molecular iodine (I2) to form AgI. However the mechanisms for organoiodine capture is not well understood. Here we investigate the capture of methyl iodide from complex mixed gas streams by combining chemical analysis of the effluent gas stream with in depth characterization of the recovered sorbent. Tools applied include infrared spectroscopy, thermogravimetric analysis with mass spectrometry, micro X-ray fluorescence, powder X-ray diffraction analysis, and pair distribution function analysis. Moreover, the MOR zeolite catalyzes decomposition of the methyl iodide through formation of surface methoxy species (SMS), which subsequently reacts with water in the mixed gas stream to form methanol, and with methanol to form dimethyl ether, which are both detected downstream in the effluent. The liberated iodine reacts with Ag in the MOR pore to the form subnanometer AgI clusters, smaller than the MOR pores, suggesting that the iodine is both physically and chemically confined within the zeolite.

  11. A pseudo-spectral method for the simulation of poro-elastic seismic wave propagation in 2D polar coordinates using domain decomposition

    SciTech Connect (OSTI)

    Sidler, Rolf, E-mail: rsidler@gmail.com [Center for Research of the Terrestrial Environment, University of Lausanne, CH-1015 Lausanne (Switzerland)] [Center for Research of the Terrestrial Environment, University of Lausanne, CH-1015 Lausanne (Switzerland); Carcione, Jos M. [Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS), Borgo Grotta Gigante 42c, 34010 Sgonico, Trieste (Italy)] [Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS), Borgo Grotta Gigante 42c, 34010 Sgonico, Trieste (Italy); Holliger, Klaus [Center for Research of the Terrestrial Environment, University of Lausanne, CH-1015 Lausanne (Switzerland)] [Center for Research of the Terrestrial Environment, University of Lausanne, CH-1015 Lausanne (Switzerland)

    2013-02-15

    We present a novel numerical approach for the comprehensive, flexible, and accurate simulation of poro-elastic wave propagation in 2D polar coordinates. An important application of this method and its extensions will be the modeling of complex seismic wave phenomena in fluid-filled boreholes, which represents a major, and as of yet largely unresolved, computational problem in exploration geophysics. In view of this, we consider a numerical mesh, which can be arbitrarily heterogeneous, consisting of two or more concentric rings representing the fluid in the center and the surrounding porous medium. The spatial discretization is based on a Chebyshev expansion in the radial direction and a Fourier expansion in the azimuthal direction and a RungeKutta integration scheme for the time evolution. A domain decomposition method is used to match the fluidsolid boundary conditions based on the method of characteristics. This multi-domain approach allows for significant reductions of the number of grid points in the azimuthal direction for the inner grid domain and thus for corresponding increases of the time step and enhancements of computational efficiency. The viability and accuracy of the proposed method has been rigorously tested and verified through comparisons with analytical solutions as well as with the results obtained with a corresponding, previously published, and independently benchmarked solution for 2D Cartesian coordinates. Finally, the proposed numerical solution also satisfies the reciprocity theorem, which indicates that the inherent singularity associated with the origin of the polar coordinate system is adequately handled.

  12. Public Interest Energy Research (PIER) Program. Final Project Report. California Energy Balance Update and Decomposition Analysis for the Industry and Building Sectors

    SciTech Connect (OSTI)

    de la Rue du Can, Stephane; Hasanbeigi, Ali; Sathaye, Jayant

    2010-12-01

    This report on the California Energy Balance version 2 (CALEB v2) database documents the latest update and improvements to CALEB version 1 (CALEB v1) and provides a complete picture of how energy is supplied and consumed in the State of California. The CALEB research team at Lawrence Berkeley National Laboratory (LBNL) performed the research and analysis described in this report. CALEB manages highly disaggregated data on energy supply, transformation, and end-use consumption for about 40 different energy commodities, from 1990 to 2008. This report describes in detail California's energy use from supply through end-use consumption as well as the data sources used. The report also analyzes trends in energy demand for the "Manufacturing" and "Building" sectors. Decomposition analysis of energy consumption combined with measures of the activity driving that consumption quantifies the effects of factors that shape energy consumption trends. The study finds that a decrease in energy intensity has had a very significant impact on reducing energy demand over the past 20 years. The largest impact can be observed in the industry sector where energy demand would have had increased by 358 trillion British thermal units (TBtu) if subsectoral energy intensities had remained at 1997 levels. Instead, energy demand actually decreased by 70 TBtu. In the "Building" sector, combined results from the "Service" and "Residential" subsectors suggest that energy demand would have increased by 264 TBtu (121 TBtu in the "Services" sector and 143 TBtu in the "Residential" sector) during the same period, 1997 to 2008. However, energy demand increased at a lesser rate, by only 162 TBtu (92 TBtu in the "Services" sector and 70 TBtu in the "Residential" sector). These energy intensity reductions can be indicative of energyefficiency improvements during the past 10 years. The research presented in this report provides a basis for developing an energy-efficiency performance index to measure progress over time in the State of California.

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

    Office of Scientific and Technical Information (OSTI)

    Electronic structure calculations reveal quasi-2D character of the Fermi surface. Authors: Ghimire, N. J. 1 ; Ronning, F. 1 ; Williams, D. J. 1 ; Scott, B. L. 1 ; Luo, ...

  14. Short time proton dynamics in bulk ice and in porous anode solid oxide fuel cell materials

    SciTech Connect (OSTI)

    Basoli, Francesco; Senesi, Roberto; Kolesnikov, Alexander I; Licoccia, Silvia

    2014-01-01

    Oxygen reduction and incorporation into solid electrolytes and the reverse reaction of oxygen evolution play a cru-cial role in Solid Oxide Fuel Cell (SOFC) applications. However a detailed un derstanding of the kinetics of the cor-responding reactions, i.e. on reaction mechanisms, rate limiting steps, reaction paths, electrocatalytic role of materials, is still missing. These include a thorough characterization of the binding potentials experienced by protons in the lattice. We report results of Inelastic Neutron Scattering (INS) measurements of the vibrational state of the protons in Ni- YSZ highly porous composites (75% to 90% ), a ceramic-metal material showing a high electrical conductivity and ther mal stability, which is known to be most effectively used as anodes for solid ox ide fuel cells. The results are compared with INS and Deep Inelastic Neutron Scattering (DINS) experiments on the proton binding states in bulk ice.

  15. Collaborative Research: Process-Resolving Decomposition of the Global Temperature Response to Modes of Low Frequency Variability in a Changing Climate

    SciTech Connect (OSTI)

    Deng, Yi

    2014-11-24

    DOE-GTRC-05596 11/24/2104 Collaborative Research: Process-Resolving Decomposition of the Global Temperature Response to Modes of Low Frequency Variability in a Changing Climate PI: Dr. Yi Deng (PI) School of Earth and Atmospheric Sciences Georgia Institute of Technology 404-385-1821, yi.deng@eas.gatech.edu El Niño-Southern Oscillation (ENSO) and Annular Modes (AMs) represent respectively the most important modes of low frequency variability in the tropical and extratropical circulations. The projection of future changes in the ENSO and AM variability, however, remains highly uncertain with the state-of-the-science climate models. This project conducted a process-resolving, quantitative evaluations of the ENSO and AM variability in the modern reanalysis observations and in climate model simulations. The goal is to identify and understand the sources of uncertainty and biases in models’ representation of ENSO and AM variability. Using a feedback analysis method originally formulated by one of the collaborative PIs, we partitioned the 3D atmospheric temperature anomalies and surface temperature anomalies associated with ENSO and AM variability into components linked to 1) radiation-related thermodynamic processes such as cloud and water vapor feedbacks, 2) local dynamical processes including convection and turbulent/diffusive energy transfer and 3) non-local dynamical processes such as the horizontal energy transport in the oceans and atmosphere. In the past 4 years, the research conducted at Georgia Tech under the support of this project has led to 15 peer-reviewed publications and 9 conference/workshop presentations. Two graduate students and one postdoctoral fellow also received research training through participating the project activities. This final technical report summarizes key scientific discoveries we made and provides also a list of all publications and conference presentations resulted from research activities at Georgia Tech. The main findings include: 1) the distinctly different roles played by atmospheric dynamical processes in establishing surface temperature response to ENSO at tropics and extratropics (i.e., atmospheric dynamics disperses energy out of tropics during ENSO warm events and modulate surface temperature at mid-, high-latitudes through controlling downward longwave radiation); 2) the representations of ENSO-related temperature response in climate models fail to converge at the process-level particularly over extratropics (i.e., models produce the right temperature responses to ENSO but with wrong reasons); 3) water vapor feedback contributes substantially to the temperature anomalies found over U.S. during different phases of the Northern Annular Mode (NAM), which adds new insight to the traditional picture that cold/warm advective processes are the main drivers of local temperature responses to the NAM; 4) the overall land surface temperature biases in the latest NCAR model (CESM1) are caused by biases in surface albedo while the surface temperature biases over ocean are related to multiple factors including biases in model albedo, cloud and oceanic dynamics, and the temperature biases over different ocean basins are also induced by different process biases. These results provide a detailed guidance for process-level model turning and improvement, and thus contribute directly to the overall goal of reducing model uncertainty in projecting future changes in the Earth’s climate system, especially in the ENSO and AM variability.

  16. The influence of the iron content on the reductive decomposition of A{sub 3?x}Fe{sub x}Al{sub 2}Si{sub 3}O{sub 12} garnets (A = Mg, Mn; 0.47 ? x ? 2.85)

    SciTech Connect (OSTI)

    Aparicio, Claudia, E-mail: claudia.aparicio@upol.cz; Filip, Jan, E-mail: claudia.aparicio@upol.cz; Mashlan, Miroslav, E-mail: claudia.aparicio@upol.cz; Zboril, Radek, E-mail: claudia.aparicio@upol.cz [Regional Centre of Advanced Technologies and Materials, Departments of Experimental Physics and Physical Chemistry, Faculty of Science, Palacky University, 17. listopadu 1192/12, 77146 Olomouc (Czech Republic)

    2014-10-27

    Thermally-induced reductive decomposition of natural iron-bearing garnets of the almandine-pyrope and almandine-spessartine series were studied at temperatures up to 1200 C (heating rate of 10 C/min) under atmosphere of forming gas (10% of H{sub 2} in N{sub 2}). Crystallochemical formula of the studied garnet was calculated as {sup VIII}(A{sub 3?x}Fe{sub x}{sup 2+}){sup VI}(Al,Fe{sup 3+}){sub 2}Si{sub 3}O{sub 12}, where the amount of Fe{sup 3+} in the octahedral sites is negligible with the exception of pyrope, A = Mg, Mn, and 0.47 ? x ? 2.85. The observed decomposition temperature, determined from differential scanning calorimetry and thermogravimetry, is greater than 1000 C in all cases and showed almost linear dependence on the iron content in the dodecahedral sites of the studied garnets, with the exception of garnet with a near-pyrope composition (Prp{sub 80}Alm{sub 20}). The initial garnet samples and decomposition products were characterized in details by means of X-ray powder diffraction and {sup 57}Fe Mssbauer spectroscopy. We found that all studied garnets have common decomposition products such as metallic iron (in general, rounded particles below 4 ?m) and Fe-spinel; the other identified decomposition products depend on starting chemical composition of the garnet: Fe-cordierite, olivine (fayalite or tephroite), cristobalite, pyroxene (enstatite or pigeonite), and anorthite. Anorthite and pigeonite were only present in garnets with Ca in the dodecahedral site. All the identified phases were usually well crystallized.

  17. Thermoelectric and microstructural properties of Pb{sub 0.9-x}Sn{sub 0.1}Ge{sub x}Te compounds prepared by spinodal decomposition

    SciTech Connect (OSTI)

    Sondergaard, M.; Christensen, M.; Johnsen, S. [Center for Energy Materials, Department of Chemistry and iNANO, Aarhus University, DK-8000 Aarhus C (Denmark); Stiewe, C.; Dasgupta, T.; Mueller, E. [German Aerospace Center (DLR), Linder Hoehe, DE-51147 Cologne (Germany); Iversen, B.B., E-mail: bo@chem.au.d [Center for Energy Materials, Department of Chemistry and iNANO, Aarhus University, DK-8000 Aarhus C (Denmark)

    2011-05-15

    Three samples of Pb{sub 0.9-x}Sn{sub 0.1}Ge{sub x}Te with x=0.25, 0.35, 0.6 were prepared by heating the mixtures above the melting point of the constituent elements followed by quenching in water. The x=0.6 sample is close to the center of the immiscibility region, while the x=0.25 and 0.35 samples are in the Pb rich region inside the spinodal miscibility gap. Microstructural investigations using Powder X-ray Diffraction, Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy revealed both GeTe-rich and PbTe-rich phases. The samples were uniaxially hot pressed and the thermoelectric properties were characterized in the temperature range 2-400 K using a commercial apparatus and from 300 to 650 K with a custom designed setup. The best sample (x=0.6) reached zT{approx}0.6 at 650 K, while the x=0.25 and 0.35 samples showed thermal instability at elevated temperatures. -- Graphical abstract: Spinodal decomposition in the GeTe-SnTe-PbTe system demonstrated by SEM and EXS images. Display Omitted Highlights: {yields} Investigation of Pb-rich part of the spinodal miscibility gap in PbTe-SnTe-GeTe. {yields} zT=0.6 at 650 K reproduced for Pb{sub 0.3}Sn{sub 0.1}Ge{sub 0.6}Te. {yields} Pb-rich phases shown to be thermally instable. {yields} Thermoelectric property characterization at low and high temperature. {yields} Microstructural investigations using PXRD, SEM, EDX and PSM.

  18. Task Decomposition in Human Reliability Analysis

    SciTech Connect (OSTI)

    Boring, Ronald Laurids; Joe, Jeffrey Clark

    2014-06-01

    In the probabilistic safety assessments (PSAs) used in the nuclear industry, human failure events (HFEs) are determined as a subset of hardware failures, namely those hardware failures that could be triggered by human action or inaction. This approach is top-down, starting with hardware faults and deducing human contributions to those faults. Elsewhere, more traditionally human factors driven approaches would tend to look at opportunities for human errors first in a task analysis and then identify which of those errors is risk significant. The intersection of top-down and bottom-up approaches to defining HFEs has not been carefully studied. Ideally, both approaches should arrive at the same set of HFEs. This question remains central as human reliability analysis (HRA) methods are generalized to new domains like oil and gas. The HFEs used in nuclear PSAs tend to be top-down— defined as a subset of the PSA—whereas the HFEs used in petroleum quantitative risk assessments (QRAs) are more likely to be bottom-up—derived from a task analysis conducted by human factors experts. The marriage of these approaches is necessary in order to ensure that HRA methods developed for top-down HFEs are also sufficient for bottom-up applications.

  19. The Natural Helmholtz-Hodge Decomposition

    Energy Science and Technology Software Center (OSTI)

    2015-08-20

    nHHD is a C++ library to decompose a flow field into three components exhibiting specific types of behaviors. These components allow more targeted analysis of flow behavior and can be applied to a variety of application areas.

  20. Method for thermochemical decomposition of water

    DOE Patents [OSTI]

    Abraham, Bernard M.; Schreiner, Felix

    1977-01-11

    Water is thermochemically decomposed to produce hydrogen by the following sequence of reactions: KI, NH.sub.3, CO.sub. 2 and water in an organic solvent such as ethyl or propyl alcohol are reacted to produce KHCO 3 and NH.sub.4 I. The KHCO.sub.3 is thermally decomposed to K.sub.2 CO.sub.3, H.sub.2 O and CO.sub.2, while the NH.sub.4 I is reacted with Hg to produce HgI.sub.2, NH.sub.3 and H.sub.2. The K.sub.2 CO.sub.3 obtained by calcining KHCO.sub.3 is then reacted with HgI.sub.2 to produce Hg, KI, CO and O.sub.2. All products of the reaction are recycled except hydrogen and oxygen.

  1. Use of oxide decompositions in advanced thermochemical hydrogen cycles for solar heat sources. Experimental results on the low-temperature reactions for the tricobalt tetraoxide-cobalt monoxide pair

    SciTech Connect (OSTI)

    Jones, W.M.; Bowman, M.G.

    1982-01-01

    The concept of utilizing oxide decompositions in advanced thermochemical hydrogen cycles for solar heat sources is introduced. It has particular interest in allowing direct transmission of energy to the process through an air window. A cycle for the Co/sub 3/O/sub 4/-CoO pair would be, schematically: (1) Co/sub 3/O/sub 4/ = 3CoO + 1/2 O/sub 2/; (2) I/sub 2/(s,1) + Mg(OH)/sub 2/ + 3CoO = MgI/sub 2/(aq) + Co/sub 3/O/sub 4/ + H/sub 2/O(1); (3) H/sub 2/O + MgI/sub 2/(aq) = MgO + 2HI; (4) 2 HI = H/sub 2/ + I/sub 2/; (5) MgO + H/sub 2/O = Mg(OH)/sub 2/. Reaction (2) should give a high concentration of MgI/sub 2/ that would be favorable for (3). The solutions would also contain iodine dissolved as polyiodide, partly offsetting this advantage. Preliminary results indicate that reaction (2) is slow at 150/sup 0/C. It is surmised that the mechanism of (2) consists of the iodine disproportionation reaction (6), followed by reaction (7). (6) I/sub 2/(s,1) + Mg(OH)/sub 2/ = 5/6 MgI/sub 2/(aq) + 1/6 Mg(IO/sub 3/)/sub 2/(aq) + H/sub 2/O(1); (7) 1/6 Mg(IO/sub 3/)/sub 2/(aq) + 3 CoO = 1/6 MgI/sub 2/(aq) + Co/sub 3/O/sub 4/. Other workers have found (6) to be relatively fast and with a good yield at 150/sup 0/C. We have found the independently studied reaction (7) to be sufficiently slow at 150/sup 0/C to account for the slowness of (2). The yield of (7) was found to be proportional to the square root of the time, which suggests that iodate must diffuse through an adherent, accumulating Co/sub 3/O/sub 4/ layer. Since (7) is much faster when Mg(IO/sub 3/)/sub 2/ is replaced by KIO/sub 3/, the Mg/sup 2 +/ ion may catalyze formation of an adherent Co/sub 3/O/sub 4/ spinel layer. The reactivity of CoO in the KIO/sub 3/ analog of (7) is greatly decreased by exposure to high temperature.

  2. Pressure Dependent Decomposition Kinetics of the Energetic Material...

    Office of Scientific and Technical Information (OSTI)

    Sponsoring Org: USDOE Country of Publication: United States Language: English Subject: 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ACCELERATION; DIAMONDS; KINETICS;...

  3. Method for increasing steam decomposition in a coal gasification process

    DOE Patents [OSTI]

    Wilson, M.W.

    1987-03-23

    The gasification of coal in the presence of steam and oxygen is significantly enhanced by introducing a thermochemical water- splitting agent such as sulfuric acid, into the gasifier for decomposing the steam to provide additional oxygen and hydrogen usable in the gasification process for the combustion of the coal and enrichment of the gaseous gasification products. The addition of the water-splitting agent into the gasifier also allows for the operation of the reactor at a lower temperature.

  4. Spinodal Decomposition and Nucleation and Growth as a Means to...

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

    C. Uher, T. Hogan, M. G. Kanatzidis, et.al Year: 2007 Abstract: URL: Link to article - FTIR spectroscopy and Thermal Analysis labs Document: Download Document (PDF) - 6962.01kb...

  5. Thermal decomposition of silane to form hydrogenated amorphous Si

    DOE Patents [OSTI]

    Strongin, M.; Ghosh, A.K.; Wiesmann, H.J.; Rock, E.B.; Lutz, H.A. III

    Hydrogenated amorphous silicon is produced by thermally decomposing silane (SiH/sub 4/) or other gases comprising H and Si, at elevated temperatures of about 1700 to 2300/sup 0/C, in a vacuum of about 10/sup -8/ to 10/sup -4/ torr. A gaseous mixture is formed of atomic hydrogen and atomic silicon. The gaseous mixture is deposited onto a substrate to form hydrogenated amorphous silicon.

  6. Method of generating hydrogen by catalytic decomposition of water

    DOE Patents [OSTI]

    Balachandran, Uthamalingam (Hinsdale, IL); Dorris, Stephen E. (LaGrange Park, IL); Bose, Arun C. (Pittsburgh, PA); Stiegel, Gary J. (Library, PA); Lee, Tae-Hyun (Naperville, IL)

    2002-01-01

    A method for producing hydrogen includes providing a feed stream comprising water; contacting at least one proton conducting membrane adapted to interact with the feed stream; splitting the water into hydrogen and oxygen at a predetermined temperature; and separating the hydrogen from the oxygen. Preferably the proton conducting membrane comprises a proton conductor and a second phase material. Preferable proton conductors suitable for use in a proton conducting membrane include a lanthanide element, a Group VIA element and a Group IA or Group IIA element such as barium, strontium, or combinations of these elements. More preferred proton conductors include yttrium. Preferable second phase materials include platinum, palladium, nickel, cobalt, chromium, manganese, vanadium, silver, gold, copper, rhodium, ruthenium, niobium, zirconium, tantalum, and combinations of these. More preferably second phase materials suitable for use in a proton conducting membrane include nickel, palladium, and combinations of these. The method for generating hydrogen is preferably preformed in the range between about 600.degree. C. and 1,700.degree. C.

  7. Method for increasing steam decomposition in a coal gasification process

    DOE Patents [OSTI]

    Wilson, Marvin W. (Fairview, WV)

    1988-01-01

    The gasification of coal in the presence of steam and oxygen is significantly enhanced by introducing a thermochemical water-splitting agent such as sulfuric acid, into the gasifier for decomposing the steam to provide additional oxygen and hydrogen usable in the gasification process for the combustion of the coal and enrichment of the gaseous gasification products. The addition of the water-splitting agent into the gasifier also allows for the operation of the reactor at a lower temperature.

  8. Meson mass decomposition from lattice QCD (Journal Article) ...

    Office of Scientific and Technical Information (OSTI)

    This content will become publicly available on April 27, 2016 Title: Meson mass ... become publicly available on April 27, 2016 Publisher's Version of Record 10.1103...

  9. Decomposition of calcium sulfate: a review of the literature...

    Office of Scientific and Technical Information (OSTI)

    of regeneration of the various regeneration schemes. Authors: Swift, W M ; Panek, A F ; Smith, G W ; Vogel, G J ; Jonke, A A Publication Date: 1976-12-01 OSTI Identifier: 7224692...

  10. DECOMPOSITION OF CALCIUM SULFATE: A REVIEW OF THE LITERATURE

    Office of Scientific and Technical Information (OSTI)

    OF CALCIUM SULFATE: A REVIEW OF THE LITERATURE W. M. Swift, A. F. Panek, G. W. Smith, 0 . J. Vogel, and A. A. Jonke " . . " """ "--..- ARGONNE NATIONAL LABORATORY,...

  11. Integrated boiler, superheater, and decomposer for sulfuric acid decomposition

    DOE Patents [OSTI]

    Moore, Robert; Pickard, Paul S.; Parma, Jr., Edward J.; Vernon, Milton E.; Gelbard, Fred; Lenard, Roger X.

    2010-01-12

    A method and apparatus, constructed of ceramics and other corrosion resistant materials, for decomposing sulfuric acid into sulfur dioxide, oxygen and water using an integrated boiler, superheater, and decomposer unit comprising a bayonet-type, dual-tube, counter-flow heat exchanger with a catalytic insert and a central baffle to increase recuperation efficiency.

  12. Closed-form decomposition of one-loop massive amplitudes

    SciTech Connect (OSTI)

    Britto, Ruth; Feng Bo; Mastrolia, Pierpaolo

    2008-07-15

    We present formulas for the coefficients of 2-, 3-, 4-, and 5-point master integrals for one-loop massive amplitudes. The coefficients are derived from unitarity cuts in D dimensions. The input parameters can be read off from any unitarity-cut integrand, as assembled from tree-level expressions, after simple algebraic manipulations. The formulas presented here are suitable for analytical as well as numerical evaluation. Their validity is confirmed in two known cases of helicity amplitudes contributing to gg{yields}gg and gg{yields}gH, where the masses of the Higgs and the fermion circulating in the loop are kept as free parameters.

  13. Protermosolar | Open Energy Information

    Open Energy Info (EERE)

    Place: Sevilla, Spain Zip: 41092 Sector: Solar Product: Association of Solar Ther Electricity Generation (STEG) and equipment providers in Spain References:...

  14. Alliance to Save Energy | Open Energy Information

    Open Energy Info (EERE)

    Washington, DC Zip: 20036 Sector: Efficiency Product: String representation "Founded in 1977 ... ther countries." is too long. References: Alliance to Save Energy1 Information...

  15. Swatch Group | Open Energy Information

    Open Energy Info (EERE)

    Swatch Group Jump to: navigation, search Name: Swatch Group Place: Switzerland Product: String representation "The Swatch Grou ... ther industries" is too long. References: Swatch...

  16. A Flow-Channel Analysis for the Mars Hopper

    SciTech Connect (OSTI)

    W. Spencer Cooley

    2013-02-01

    The Mars Hopper is an exploratory vehicle designed to fly on Mars using carbon dioxide from the Martian atmosphere as a rocket propellant. The propellent gasses are thermally heated while traversing a radioisotope ther- mal rocket (RTR) engines core. This core is comprised of a radioisotope surrounded by a heat capacitive material interspersed with tubes for the propellant to travel through. These tubes, or flow channels, can be manu- factured in various cross-sectional shapes such as a special four-point star or the traditional circle. Analytical heat transfer and computational fluid dynamics (CFD) anal- yses were performed using flow channels with either a circle or a star cross- sectional shape. The nominal total inlet pressure was specified at 2,805,000 Pa; and the outlet pressure was set to 2,785,000 Pa. The CO2 inlet tem- perature was 300 K; and the channel wall was 1200 K. The steady-state CFD simulations computed the smooth-walled star shapes outlet temper- ature to be 959 K on the finest mesh. The smooth-walled circles outlet temperature was 902 K. A circle with a surface roughness specification at 0.01 mm gave 946 K and at 0.1 mm yielded 989 K. The The effects of a slightly varied inlet pressure were also examined. The analytical calculations were based on the mass flow rates computed in the CFD simulations and provided significantly higher outlet temperature results while displaying the same comparison trends. Research relating to the flow channel heat transfer studies was also done. Mathematical methods to geometrically match the cross-sectional areas of the circle and star, along with a square and equilateral triangle, were derived. A Wolfram Mathematica 8 module was programmed to analyze CFD results using Richardson Extrapolation and calculate the grid convergence index (GCI). A Mathematica notebook, also composed, computes and graphs the bulk mean temperature along a flow channels length while the user dynam- ically provides the input variables, allowing their effects on the temperature to be more easily observed.

  17. Fourier decomposition of polymer orientation in large-amplitude oscillatory shear flow

    SciTech Connect (OSTI)

    Giacomin, A. J.; Gilbert, P. H.; Schmalzer, A. M.

    2015-03-19

    In our previous work, we explored the dynamics of a dilute suspension of rigid dumbbells as a model for polymeric liquids in large-amplitude oscillatory shear flow, a flow experiment that has gained a significant following in recent years. We chose rigid dumbbells since these are the simplest molecular model to give higher harmonics in the components of the stress response. We derived the expression for the dumbbell orientation distribution, and then we used this function to calculate the shear stress response, and normal stress difference responses in large-amplitude oscillatory shear flow. In this paper, we deepen our understanding of the polymer motion underlying large-amplitude oscillatory shear flow by decomposing the orientation distribution function into its first five Fourier components (the zeroth, first, second, third, and fourth harmonics). We use three-dimensional images to explore each harmonic of the polymer motion. Our analysis includes the three most important cases: (i) nonlinear steady shear flow (where the Deborah number λω is zero and the Weissenberg number λγ 0 is above unity), (ii) nonlinear viscoelasticity (where both λω and λγ 0 exceed unity), and (iii) linear viscoelasticity (where λω exceeds unity and where λγ 0 approaches zero). We learn that the polymer orientation distribution is spherical in the linear viscoelastic regime, and otherwise tilted and peanut-shaped. We find that the peanut-shaping is mainly caused by the zeroth harmonic, and the tilting, by the second. The first, third, and fourth harmonics of the orientation distribution make only slight contributions to the overall polymer motion.

  18. Strain of alcaligenes latus bacteria used for the decomposition of polychlorinated biphenyls

    DOE Patents [OSTI]

    Dyadischev, Nikolai Romanovich (Moscow Region, RU); Zharikov, Gennady Alekseevich (Moscow Region, RU); Kapranov, Vladimir Vladimirovich (Moscow Region, RU)

    2001-09-11

    Alcaligenes latus bacterial strain TXD-13 VKPM B 75-05 is capable of degrading polychlorinated biphenyls (PCBs). The strain may be employed to detoxicate environment media and PCB-containing industrial waste. To produce biomass, the strain is incubated on media which contain carbon sources, nitrogen sources and mineral salts. The strain is cultivated by a subsurface method up to a titer from 6.0.multidot.10.sup.8 to 2.0.times.10.sup.9 cells per cu cm. The produced biomass is used for degrading PCBs in concentrations from 10.sup.7 to 10.sup.8 cells per cu cm. The strain ensures from 35 to 50% reduction in PCB content in soil and water.

  19. Unconstrained plastering : all-hexahedral mesh generation via advancing front geometry decomposition (2004-2008).

    SciTech Connect (OSTI)

    Blacker, Teddy Dean; Staten, Matthew L.; Kerr, Robert A.; Owen, Steven James

    2010-03-01

    The generation of all-hexahedral finite element meshes has been an area of ongoing research for the past two decades and remains an open problem. Unconstrained plastering is a new method for generating all-hexahedral finite element meshes on arbitrary volumetric geometries. Starting from an unmeshed volume boundary, unconstrained plastering generates the interior mesh topology without the constraints of a pre-defined boundary mesh. Using advancing fronts, unconstrained plastering forms partially defined hexahedral dual sheets by decomposing the geometry into simple shapes, each of which can be meshed with simple meshing primitives. By breaking from the tradition of previous advancing-front algorithms, which start from pre-meshed boundary surfaces, unconstrained plastering demonstrates that for the tested geometries, high quality, boundary aligned, orientation insensitive, all-hexahedral meshes can be generated automatically without pre-meshing the boundary. Examples are given for meshes from both solid mechanics and geotechnical applications.

  20. Fluctuation studies in the infinite interval matrix representations of operator products and their decompositions

    SciTech Connect (OSTI)

    Baykara, N. A.; Guervit, Ercan; Demiralp, Metin

    2012-12-10

    In this work a study on finite dimensional matrix approximations to products of quantum mechanical operators is conducted. It is emphasized that the matrix representation of the product of two operators is equal to the product of the matrix representation of each of the operators when all the fluctuation terms are ignored. The calculation of the elements of the matrices corresponding to the matrix representation of various operators, based on three terms recursive relation is defined. Finally it is shown that the approximation quality depends on the choice of higher values of n, namely the dimension of Hilbert space.

  1. Rapid hydrogen gas generation using reactive thermal decomposition of uranium hydride.

    SciTech Connect (OSTI)

    Kanouff, Michael P.; Van Blarigan, Peter; Robinson, David B.; Shugard, Andrew D.; Gharagozloo, Patricia E.; Buffleben, George M.; James, Scott Carlton; Mills, Bernice E.

    2011-09-01

    Oxygen gas injection has been studied as one method for rapidly generating hydrogen gas from a uranium hydride storage system. Small scale reactors, 2.9 g UH{sub 3}, were used to study the process experimentally. Complimentary numerical simulations were used to better characterize and understand the strongly coupled chemical and thermal transport processes controlling hydrogen gas liberation. The results indicate that UH{sub 3} and O{sub 2} are sufficiently reactive to enable a well designed system to release gram quantities of hydrogen in {approx} 2 seconds over a broad temperature range. The major system-design challenge appears to be heat management. In addition to the oxidation tests, H/D isotope exchange experiments were performed. The rate limiting step in the overall gas-to-particle exchange process was found to be hydrogen diffusion in the {approx}0.5 {mu}m hydride particles. The experiments generated a set of high quality experimental data; from which effective intra-particle diffusion coefficients can be inferred.

  2. Corrosion-resistant coating prepared by the thermal decomposition of lithium permanganate

    SciTech Connect (OSTI)

    Ferrando, W.A.

    1999-09-01

    A ceramic, metal, or metal alloy surface is covered with lithium permanganate which is then thermally decomposed to produce a corrosion resistant coating on the surface. This coating serves as a primer coating which is preferably covered with an overcoat of a sealing paint.

  3. Combinatorial evaluation of systems including decomposition of a system representation into fundamental cycles

    DOE Patents [OSTI]

    Oliveira, Joseph S. (Richland, WA); Jones-Oliveira, Janet B. (Richland, WA); Bailey, Colin G. (Wellington, NZ); Gull, Dean W. (Seattle, WA)

    2008-07-01

    One embodiment of the present invention includes a computer operable to represent a physical system with a graphical data structure corresponding to a matroid. The graphical data structure corresponds to a number of vertices and a number of edges that each correspond to two of the vertices. The computer is further operable to define a closed pathway arrangement with the graphical data structure and identify each different one of a number of fundamental cycles by evaluating a different respective one of the edges with a spanning tree representation. The fundamental cycles each include three or more of the vertices.

  4. Method for production of ceramic oxide and carbide bodies by polymer inclusion and decomposition

    DOE Patents [OSTI]

    Quinby, Thomas C. (Kingston, TN)

    1985-01-01

    A method for the preparation of thin, free-standing metal oxide films which are useful as nuclear accelerator target materials. Cations of any metal except those of Group IA and precious metals, such as, U, Zr, Nd, Ce, Th, pr or Cr, are absorbed on a thin film of polymeric material, such as, carboxymethylcellulose, viscose rayon or cellophane. The cation impregnated polymeric material is dried. Then the impregnated film is heated in an inert atmosphere to form a carbonized membrane. The carbonized membrane is oxidized to yield a thin, self-supporting, metal oxide membrane. Or, the membrane can be heated in an inert atmosphere to yield a thin, self-supporting, metal carbide-containing membrane.

  5. Method for production of ceramic oxide and carbide bodies by polymer inclusion and decomposition

    DOE Patents [OSTI]

    Quinby, T.C.

    1984-08-30

    A method for the preparation of thin, free-standing metal oxide films which are useful as nuclear accelerator target materials is described. Cations of any metal except those of Group IA and precious metals, such as, U, Zr, Nd, Ce, Th, Pr or Cr, are absorbed on a thin film of polymeric material, such as carboxymethylcellulose, viscose rayon or cellophane. The cation impregnated polymeric material is dried. Then the impregnated film is heated in an inert atmosphere to form a carbonized membrane. The carbonized membrane is oxidized to yield a thin, self-supporting, metal oxide membrane. Or, the membrane can be heated in an inert atmosphere to yield a thin, self-supporting, metal carbide-containing membrane.

  6. Fourier decomposition of polymer orientation in large-amplitude oscillatory shear flow

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

    Giacomin, A. J.; Gilbert, P. H.; Schmalzer, A. M.

    2015-03-19

    In our previous work, we explored the dynamics of a dilute suspension of rigid dumbbells as a model for polymeric liquids in large-amplitude oscillatory shear flow, a flow experiment that has gained a significant following in recent years. We chose rigid dumbbells since these are the simplest molecular model to give higher harmonics in the components of the stress response. We derived the expression for the dumbbell orientation distribution, and then we used this function to calculate the shear stress response, and normal stress difference responses in large-amplitude oscillatory shear flow. In this paper, we deepen our understanding of themore » polymer motion underlying large-amplitude oscillatory shear flow by decomposing the orientation distribution function into its first five Fourier components (the zeroth, first, second, third, and fourth harmonics). We use three-dimensional images to explore each harmonic of the polymer motion. Our analysis includes the three most important cases: (i) nonlinear steady shear flow (where the Deborah number λω is zero and the Weissenberg number λγ 0 is above unity), (ii) nonlinear viscoelasticity (where both λω and λγ 0 exceed unity), and (iii) linear viscoelasticity (where λω exceeds unity and where λγ 0 approaches zero). We learn that the polymer orientation distribution is spherical in the linear viscoelastic regime, and otherwise tilted and peanut-shaped. We find that the peanut-shaping is mainly caused by the zeroth harmonic, and the tilting, by the second. The first, third, and fourth harmonics of the orientation distribution make only slight contributions to the overall polymer motion.« less

  7. Novel Composite Hydrogen-Permeable Membranes for Nonthermal Plasma Reactors for the Decomposition of Hydrogen Sulfide

    SciTech Connect (OSTI)

    Morris Argyle; John Ackerman; Suresh Muknahallipatna; Jerry Hamann; Stanislaw Legowski; Gui-Bing Zhao; Sanil John; Ji-Jun Zhang; Linna Wang

    2007-09-30

    The goal of this experimental project was to design and fabricate a reactor and membrane test cell to dissociate hydrogen sulfide (H{sub 2}S) in a nonthermal plasma and to recover hydrogen (H{sub 2}) through a superpermeable multi-layer membrane. Superpermeability of hydrogen atoms (H) has been reported by some researchers using membranes made of Group V transition metals (niobium, tantalum, vanadium, and their alloys), but it was not achieved at the moderate pressure conditions used in this study. However, H{sub 2}S was successfully decomposed at energy efficiencies higher than any other reports for the high H{sub 2}S concentration and moderate pressures (corresponding to high reactor throughputs) used in this study.

  8. Hydrogen production from water decomposition by redox of Fe{sub...

    Office of Scientific and Technical Information (OSTI)

    DOI: 10.1016j.jssc.2010.03.017; PII: S0022-4596(10)00095-2; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved. Country of...

  9. On the formation and decomposition of C{sub 7}H{sub 8}.

    SciTech Connect (OSTI)

    Klippenstein, S. J.; Harding, L. B.; Georgievskii, Y.; Chemistry; SNL

    2007-01-01

    The kinetics of reactions on the C{sub 7}H{sub 8} surface were studied with state-of-the-art ab initio transition state theory (TST) and master equation methodologies. A priori predictions of the capture rate for C{sub 6}H{sub 5} + CH{sub 3} and for C{sub 7}H{sub 7} + H are obtained from direct variable reaction coordinate TST simulations. These simulations employ small basis set CASPT2 interaction energies coupled with one-dimensional reaction path corrections based on higher level simulations for related reactions. For the C{sub 7}H{sub 7} + H reaction, predictions are obtained for both the total rate and for the branching between toluene, o-isotoluene and p-isotoluene. A mapping of the low energy pathways for isomerization from these three C{sub 7}H{sub 8} isomers identifies a number of processes with barriers at or below the dissociation threshold. Nevertheless, at combustion temperatures the dissociation rates are predicted to exceed the isomerization rates, and it is reasonable to treat the kinetics of each isomer as a simple single well association/dissociation equilibrium. Master equation simulations yield predictions for the temperature and pressure dependence of each of the recombination and dissociation processes, as well as for the C{sub 7}H{sub 7} + H {yields} C{sub 6}H{sub 5} + CH{sub 3} bimolecular reaction. These simulations implement collisional energy transfer probabilities based on the work of Luther and co-workers. The theoretical predictions are found to be in satisfactory agreement with the available experimental data for the photodissociation of toluene, the temperature and pressure dependent dissociation of toluene, and the reaction of benzyl radical with H. For the C{sub 6}H{sub 5} + CH{sub 3} recombination, the theoretical predictions exceed the experimental measurements of Lin and coworkers by a factor of 2 or more for all temperatures.

  10. One Size Does Not Fit All: Human Failure Event Decomposition and Task Analysis

    SciTech Connect (OSTI)

    Ronald Laurids Boring, PhD

    2014-09-01

    In the probabilistic safety assessments (PSAs) used in the nuclear industry, human failure events (HFEs) are determined as a subset of hardware failures, namely those hardware failures that could be triggered or exacerbated by human action or inaction. This approach is top-down, starting with hardware faults and deducing human contributions to those faults. Elsewhere, more traditionally human factors driven approaches would tend to look at opportunities for human errors first in a task analysis and then identify which of those errors is risk significant. The intersection of top-down and bottom-up approaches to defining HFEs has not been carefully studied. Ideally, both approaches should arrive at the same set of HFEs. This question remains central as human reliability analysis (HRA) methods are generalized to new domains like oil and gas. The HFEs used in nuclear PSAs tend to be top-downdefined as a subset of the PSAwhereas the HFEs used in petroleum quantitative risk assessments (QRAs) are more likely to be bottom-upderived from a task analysis conducted by human factors experts. The marriage of these approaches is necessary in order to ensure that HRA methods developed for top-down HFEs are also sufficient for bottom-up applications. In this paper, I first review top-down and bottom-up approaches for defining HFEs and then present a seven-step guideline to ensure a task analysis completed as part of human error identification decomposes to a level suitable for use as HFEs. This guideline illustrates an effective way to bridge the bottom-up approach with top-down requirements.

  11. A Linked-Cell Domain Decomposition Method for Molecular Dynamics Simulation on a Scalable Multiprocessor

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

    Yang, L. H.; Brooks III, E. D.; Belak, J.

    1992-01-01

    A molecular dynamics algorithm for performing large-scale simulations using the Parallel C Preprocessor (PCP) programming paradigm on the BBN TC2000, a massively parallel computer, is discussed. The algorithm uses a linked-cell data structure to obtain the near neighbors of each atom as time evoles. Each processor is assigned to a geometric domain containing many subcells and the storage for that domain is private to the processor. Within this scheme, the interdomain (i.e., interprocessor) communication is minimized.

  12. Decomposition of PCBs in Oils Using Gamma Radiolysis A Treatability Study - Final Report

    SciTech Connect (OSTI)

    B. J. Mincher; R. E. Arbon

    1996-08-01

    Several legacy hydraulic oil waste streams contaminated with Aroclor 1260 and small amounts of Cesium-137 have been in storage at the Idaho National Engineering Laboratory (INEL) due to the lack of appropriate treatment facilities. The goal of this study was to demonstrate that polychlorinated biphenyls (PCBs) could be selectively decomposed in the oils. Removal of the PCB component to less than the 2 mg/L treatment standard should result in a waste oil that is not regulated by the Toxic Substances Control Act. Irradiation of the oils with high gamma-ray doses produces free electrons in the solution that react with PCBs. The reaction results in dechlorination of the PCBs to produce biphenyl. The gamma-ray source was spent reactor fuel stored in the Advanced Test Reactor canal at the INEL. A dry tube extends into the canal which allowed for positioning of samples in the proximity of the fuel. The gamma-ray dose rates at the samples varied from 10 to 30 kGy/h. This was measured using commercially available FWT-60 dosimeters. Irradiation of samples in a series of progressively increasing absorbed doses allowed the generation of rate constants used to predict absorbed doses necessary to meet the 2 mg/kg treatment standard. Three separate irradiation experiments were performed. The first irradiation used a maximum absorbed dose of 183 kGy. This experiment demonstrated that the PCB concentration decreased and allowed calculation of preliminary rate constants. The second irradiation used a maximum absorbed dose of 760 kGy. From this experiment, accurate rate constants were calculated, and the necessary absorbed dose to achieve the treatment standard was calculated. In the third irradiation of 2,242 kGy, all three waste streams were adequately decontaminated.

  13. Effect of Morphology of CdS thin film on the Photocatalytic Decomposition of Hydrogen Sulfide

    SciTech Connect (OSTI)

    Takahashi, A.; Ishiyama, T.; Takahashi, H.; Sato, Y.; Jeyadevan, B.; Tohji, K.

    2007-03-20

    Photocatalytic activity of the CdS thin film depended very much on the film density, adhesion between the CdS and substrate, and whether effective electron path existed or not. We have proposed the formation of a bridging layer of Cd metal to improve the film density, adhesivity and the electron conduction path. Here, we report the results of the study undertaken to develop CdS/Cd (dendrite)/Ti film with enhanced photocatalytic property to decompose hydrogen sulphide. CdS/Cd (dendrite)/Ti photocatalyst showed the highest photocatalytic activity and photocurrent, which was 1.4 times higher than the traditional CdS/Ti photocatalyst.

  14. Isospin Decomposition of the Photoproduced Sigma pi System Near the Lambda(1405)

    SciTech Connect (OSTI)

    Carnegie Mellon U.; Indiana U.

    2013-09-01

    Recent experimental results for the reaction \\gamma + p \\to K^+ + \\Sigma + \\pi\\ from CLAS at Jefferson Lab are discussed. It was found that the mass distributions or "line shapes" of the three charge combinations \\Sigma^+ \\pi^-, \\Sigma^0 \\pi^0 and \\Sigma^- \\pi^+ differ significantly. Our results show that the \\Lambda(1405), as the I=0 constituent of the reaction, must be accompanied by an I > 0 component. We discuss phenomenological fits to the data to test the possible forms and magnitudes of these amplitudes. A two-amplitude I=0 fit of Breit-Wigner form to the \\Sigma^0\\pi^0 channel alone works quite well. The addition of a single I=1 amplitude works fairly well to model all the line shapes simultaneously.

  15. Pulse-burst

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

    level of the active Nd ion in the rod also begins to be ther- mally populated from the ground state. 11 The rods in our laser should be well under this limit at the end of a...

  16. Ultralow-Power Silicon Microphotonic Communications Platform

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

    Other Applications O ther applications extend across the full spectrum of high-speed digital systems, from chip-to-chip to intra-chip applications. Examples include high-speed...

  17. BPA-2014-01328-FOIA Response

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

    0 Alarm 181 Auto Accident 0 Client Comp. 0 Emergency 0 Fire 0 Open SafeFile 0 Prop. Damage 0 Safety Hazard 0 Susp Person(s) 0 Theft 0 Water Leak 00ther Explain: Vehicle...

  18. Investigating the Mechanism of Catalytic Tetraphenylborate Decomposition Using Nuclear Magnetic Resonance Spectrometry: Initial Studies in FY00

    SciTech Connect (OSTI)

    Bonnesen, P.V.

    2001-01-30

    The key findings from this study can be summarized as follows: (1) palladium appears to be capable of catalyzing the degradation in the absence of mercury; (2) when mercury was added to the palladium system in the form of mercuric nitrate or phenylmercuric nitrate basic, the rate of TPB degradation was roughly the same as the rate without mercury present; (3) when mercury was added to the system in the form of diphenylmercury, the rate of TPB degradation was greatly accelerated; (4) no TPB degradation was observed for a system which contained phenylmercuric nitrate basic alone with no palladium present; (5) the distribution of lower phenylborates (1 PB, 2PB, and 3PB) varied as a function of the catalyst system; (6) no lower phenylborates were observed during the first 17 hours of reaction indicating that an ''induction period'' may be necessary; and (7) the appearance of precipitates in the reaction mixture varied with the catalyst system, possibly indicating that the active catalyst that is formed may vary with the chemical form of mercury added.

  19. Decomposition of tetraphenylborate precipitates used to isolate Cs-137 from Savannah River Site high-level waste

    SciTech Connect (OSTI)

    Ferrara, D.M.; Bibler, N.E.; Ha, B.C.

    1993-03-01

    This paper presents results of the radioactive demonstration of the Precipitate Hydrolysis Process (PHP) that will be performed in the Defense Waste Processing Facility (DWPF) at the Savannah River Site. The PHP destroys the tetraphenylborate precipitate that is used at SRS to isolate Cs-137 from caustic High-Level Waste (HLW) supernates. This process is necessary to decrease the amount of organic compounds going to the melter in the DWPF. Actual radioactive precipitate containing Cs-137 was used for this demonstration.

  20. Measurements of the Neutron Longitudinal Spin Asymmetry A1n and Flavor Decomposition in the Valence Quark Region

    SciTech Connect (OSTI)

    Flay, David J.

    2014-08-01

    The current data for the nucleon-virtual photon longitudinal spin asymmetry A1 on the proton and neutron have shown that the ratio of the polarized-to-unpolarized down-quarkparton distribution functions,Dd=d, tends towards -1/2 at large x, in disagreement with the perturbative QCD prediction that Dd/d approaches 1 but more in line with constituent quark models. As a part of experiment E06-014 in Hall A of Jefferson Lab, double-spin asymmetries were measured in the scattering of a longitudinally polarized electron beam of energies 4.74 and 5.89 GeV from a longitudinally and transversely polarized 3He target in the deep inelastic scattering and resonance region, allowing for the extraction of the neutron asymmetry An1 and the ratios Dd/d and Du/u. We will discuss our analysis of the data and present results for A1 and g1/F1 on both 3He and the neutron, and the resulting quark ratios for the up and down quarks in the kinematic range of 0.2

  1. 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.

  2. NOVEL COMPOSITE HYDROGEN-PERMEABLE MEMBRANES FOR NON-THERMAL PLASMA REACTORS FOR THE DECOMPOSITION OF HYDROGEN SULFIDE

    SciTech Connect (OSTI)

    Morris D. Argyle; John F. Ackerman; Suresh Muknahallipatna; Jerry C. Hamann; Stanislaw Legowski; Ji-Jun Zhang; Guibing Zhao; Robyn J. Alcanzare; Linna Wang; Ovid A. Plumb

    2004-07-01

    The goal of this experimental project is to design and fabricate a reactor and membrane test cell to dissociate hydrogen sulfide (H{sub 2}S) in a non-thermal plasma and recover hydrogen (H{sub 2}) through a superpermeable multi-layer membrane. Superpermeability of hydrogen atoms (H) has been reported by some researchers using membranes made of Group V transition metals (niobium, tantalum, vanadium, and their alloys), although it has yet to be confirmed in this study. Experiments involving methane conversion reactions were conducted with a preliminary pulsed corona discharge reactor design in order to test and improve the reactor and membrane designs using a non-toxic reactant. This report details the direct methane conversion experiments to produce hydrogen, acetylene, and higher hydrocarbons utilizing a co-axial cylinder (CAC) corona discharge reactor, pulsed with a thyratron switch. The reactor was designed to accommodate relatively high flow rates (655 x 10{sup -6} m{sup 3}/s) representing a pilot scale easily converted to commercial scale. Parameters expected to influence methane conversion including pulse frequency, charge voltage, capacitance, residence time, and electrode material were investigated. Conversion, selectivity and energy consumption were measured or estimated. C{sub 2} and C{sub 3} hydrocarbon products were analyzed with a residual gas analyzer (RGA). In order to obtain quantitative results, the complex sample spectra were de-convoluted via a linear least squares method. Methane conversion as high as 51% was achieved. The products are typically 50%-60% acetylene, 20% propane, 10% ethane and ethylene, and 5% propylene. First Law thermodynamic energy efficiencies for the system (electrical and reactor) were estimated to range from 38% to 6%, with the highest efficiencies occurring at short residence time and low power input (low specific energy) where conversion is the lowest (less than 5%). The highest methane conversion of 51% occurred at a residence time of 18.8 s with a flow rate of 39.4 x 10{sup -6} m{sup 3}/s (5 ft{sup 3}/h) and a specific energy of 13,000 J/l using niobium and platinum coated stainless steel tubes as cathodes. Under these conditions, the First Law efficiency for the system was 8%. Under similar reaction conditions, methane conversions were {approx}50% higher with niobium and platinum coated stainless steel cathodes than with a stainless steel cathode.

  3. The Investigation of Decomposition of Supersaturated Si Solid Solution by X-Ray Diffuse Scattering

    SciTech Connect (OSTI)

    Shcherbachev, Kirill; Privezentsev, Vladimir

    2010-04-06

    The results of investigation of microstructure of Zn doped n-type Si by X-ray Diffuse Scattering (XRDS) are presented. Experimental samples were made by a high-temperature Zn diffusion annealing with subsequent quenching and tempering. Reciprocal space maps of XRDS were obtained. They resulted in that crystal lattice of the samples contains spherical MDs of vacancy type and plane shape MDs of interstitial type. The MDs average radius and their type depend on Zn doping level and thermal treatment after Zn diffusion.

  4. Method of freezing living cells and tissues with improved subsequent survival

    DOE Patents [OSTI]

    Senkan, Selim M. (Oak Ridge, TN); Hirsch, Gerald P. (Oak Ridge, TN)

    1980-01-01

    This invention relates to an improved method for freezing red blood cells, ther living cells, or tissues with improved subsequent survival, wherein constant-volume freezing is utilized that results in significantly improved survival compared with constant-pressure freezing; optimization is attainable through the use of different vessel geometries, cooling baths and warming baths, and sample concentrations.

  5. Sandia National Laboratories is a multi-program laboratory managed...

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

    c ommands a re a vailable i n t he e xis(ng S ierra G UI e ditor tools t he s ame a s o ther S ierra c ommands. Minimal c hanges a re r equired t o a n e xis(ng E...

  6. Donald Frederick, LLNL

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

    o f t he n ext generaBon o f h igh---Z m aterials s imulaBons w hile a t t he s ame B me straighlorward f or o thers t o r eplicate a nd c ompare p erformance...

  7. Neaton.ppt

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

    a mount o f c ode c hanges a nd a llow c ode p ortability ( we w ant t o r un t he s ame code o n c ommodity m achines a nd o ther H PC c enters) * NERSC g enerally r efreshes...

  8. The Los Alamos Postdoc Career Fair is an

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

    m aterials t echnology, s uper---compu>ng, a nd m any other fi elds. L ANL h as a l ong---standing t radi>on o f p artnering with u niversi>es, i ndustries, a nd o ther n...

  9. Obtaining aluminas from the thermal decomposition of their different precursors: An {sup 27}Al MAS NMR and X-ray powder diffraction studies

    SciTech Connect (OSTI)

    Chagas, L.H.; De Carvalho, G.S.G.; San Gil, R.A.S.; Chiaro, S.S.X.; Leito, A.A.; Diniz, R.

    2014-01-01

    Graphical abstract: - Highlights: We synthesized three precursors of alumina from different methods. The calcination of the precursors generated several alumina polymorphs. XRD and NMR were used for structural investigation of the polymorphs. The synthesis route determines the structural and textural properties of the solids. - Abstract: A commercial sample of Boehmite was used as precursor of alumina polymorphs. For comparison, three other precursors were synthesized from different methods. Particularly, the use of excess of urea promoted a very crystalline form of basic aluminum carbonate. The characteristics of the four precursors were investigated by thermal, vibrational and X-ray powder diffraction (XRD) analysis. Additionally, the nuclear magnetic resonance, with magic angle spinning ({sup 27}Al MAS NMR), was used to verify the coordination of aluminum cations. Each precursor was calcined at various temperatures generating alumina polymorphs, which were structurally analyzed by XRD and {sup 27}Al MAS NMR. Due to interest in catalysis supports, special attention was given to the ?-Al{sub 2}O{sub 3} phase, which in addition to structural investigation was subjected to textural analysis. The results showed that, from different synthesis procedures and common route of calcination, one can obtain materials with the same composition but with different structural and textural properties, which in turn can significantly influence the performance of a supported catalyst.

  10. Molybdenum-based additives to mixed-metal oxides for use in hot gas cleanup sorbents for the catalytic decomposition of ammonia in coal gases

    DOE Patents [OSTI]

    Ayala, Raul E. (Clifton Park, NY)

    1993-01-01

    This invention relates to additives to mixed-metal oxides that act simultaneously as sorbents and catalysts in cleanup systems for hot coal gases. Such additives of this type, generally, act as a sorbent to remove sulfur from the coal gases while substantially simultaneously, catalytically decomposing appreciable amounts of ammonia from the coal gases.

  11. The effect of PECVD plasma decomposition on the wettability and dielectric constant changes in silicon modified DLC films for potential MEMS and low stiction applications

    SciTech Connect (OSTI)

    Ogwu, A. A.; Okpalugo, T. I. T.; McLaughlin, J. A. D.

    2012-09-15

    We have carried out investigations aimed at understanding the mechanism responsible for a water contact angle increase of up to ten degrees and a decrease in dielectric constant in silicon modified hydrogenated amorphous carbon films compared to unmodified hydrogenated amorphous carbon films. Our investigations based on surface chemical constituent analysis using Raman spectroscopy, x-ray photoelectron spectroscopy (XPS), SIMS, FTIR, contact angle / surface energy measurements and spectroscopic ellipsometry suggests the presence of hydrophobic chemical entities on the surface of the films. This observation is consistent with earlier theoretical plasma chemistry predictions and observed Raman peak shifts in the films. These surface hydrophobic entities also have a lower polarizability than the bonds in the un-modified films thereby reducing the dielectric constant of the silicon modified films measured by spectroscopic ellipsometry. Ellipsometric dielectric constant measurement is directly related to the surface energy through Hamaker's constant. Our current finding is expected to be of benefit to understanding stiction, friction and lubrication in areas that range from nano-tribology to microfluidics.

  12. Application of the base catalyzed decomposition process to treatment of PCB-contaminated insulation and other materials associated with US Navy vessels. Final report

    SciTech Connect (OSTI)

    Schmidt, A.J.; Zacher, A.H.; Gano, S.R.

    1996-09-01

    The BCD process was applied to dechlorination of two types of PCB-contaminated materials generated from Navy vessel decommissioning activities at Puget Sound Naval Shipyard: insulation of wool felt impregnated with PCB, and PCB-containing paint chips/debris from removal of paint from metal surfaces. The BCD process is a two-stage, low-temperature chemical dehalogenation process. In Stage 1, the materials are mixed with sodium bicarbonate and heated to 350 C. The volatilized halogenated contaminants (eg, PCBs, dioxins, furans), which are collected in a small volume of particulates and granular activated carbon, are decomposed by the liquid-phase reaction (Stage 2) in a stirred-tank reactor, using a high-boiling-point hydrocarbon oil as the reaction medium, with addition of a hydrogen donor, a base (NaOH), and a catalyst. The tests showed that treating wool felt insulation and paint chip wastes with Stage 2 on a large scale is feasible, but compared with current disposal costs for PCB-contaminated materials, using Stage 2 would not be economical at this time. For paint chips generated from shot/sand blasting, the solid-phase BCD process (Stage 1) should be considered, if paint removal activities are accelerated in the future.

  13. Photo-initiated reactions of 2,4,6 TCP on Degussa P25 formulation TiO{sub 2} : wavelength sensitive decomposition.

    SciTech Connect (OSTI)

    Hurum, D. C.; Gray, K. A.; Rajh, T.; Thurnauer, M. C.; Chemistry; Northwestern Univ.

    2004-10-21

    The photoinitiated oxidative reactions of 2,4,6 trichlorophenol (2,4,6 TCP) and 2,4,5 trichlorophenol (2,4,5 TCP) are studied on the titania photocatalyst Degussa P25. On this catalyst 2,4,6 TCP is used to confirm two distinct oxidative mechanisms that are triggered at different light-excitation wavelengths. A charge-transfer mechanism occurs at sub-bandgap energies of the photocatalyst leading to a phenoxyl radical product and an oxidative mechanism occurs at the bandgap leading to a semiquinone radical product. The wavelength dependence of these two mechanisms is discussed.

  14. A coupled transport and solid mechanics formulation with improved reaction kinetics parameters for modeling oxidation and decomposition in a uranium hydride bed.

    SciTech Connect (OSTI)

    Salloum, Maher N.; Shugard, Andrew D.; Kanouff, Michael P.; Gharagozloo, Patricia E.

    2013-03-01

    Modeling of reacting flows in porous media has become particularly important with the increased interest in hydrogen solid-storage beds. An advanced type of storage bed has been proposed that utilizes oxidation of uranium hydride to heat and decompose the hydride, releasing the hydrogen. To reduce the cost and time required to develop these systems experimentally, a valid computational model is required that simulates the reaction of uranium hydride and oxygen gas in a hydrogen storage bed using multiphysics finite element modeling. This SAND report discusses the advancements made in FY12 (since our last SAND report SAND2011-6939) to the model developed as a part of an ASC-P&EM project to address the shortcomings of the previous model. The model considers chemical reactions, heat transport, and mass transport within a hydride bed. Previously, the time-varying permeability and porosity were considered uniform. This led to discrepancies between the simulated results and experimental measurements. In this work, the effects of non-uniform changes in permeability and porosity due to phase and thermal expansion are accounted for. These expansions result in mechanical stresses that lead to bed deformation. To describe this, a simplified solid mechanics model for the local variation of permeability and porosity as a function of the local bed deformation is developed. By using this solid mechanics model, the agreement between our reacting bed model and the experimental data is improved. Additionally, more accurate uranium hydride oxidation kinetics parameters are obtained by fitting the experimental results from a pure uranium hydride oxidation measurement to the ones obtained from the coupled transport-solid mechanics model. Finally, the coupled transport-solid mechanics model governing equations and boundary conditions are summarized and recommendations are made for further development of ARIA and other Sandia codes in order for them to sufficiently implement the model.

  15. CSTEC Working Groups

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

    January 2 010 --- A ugust 2 010 Transport ( merged i nto o ther T hin F ilms, T E, a nd A bsorption a fter s ummer 2 010) February 1 Discussion a bout f ormat o f m eetings February 2 2 PC K u p resented h is r esearch June 11 Sung J oo K im p resenting July 3 0 Discussion o f O rtmann 2 009 P RB p aper o n c harge t ransport Theory ( merged i nto o ther w orking g roups) February 1 9 Discussion o n f ormat o f m eetings Thin F ilms February 9 Discussion o f f ormat o f m eetings March 2 Steve F

  16. GSA Office of Governmentwide Policy CIVILIAN AGENCY ACQUISITION LETTER 2013-03

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

    Policy CIVILIAN AGENCY ACQUISITION LETTER 2013-03 May 7, 2013 MEMORANDUM FOR Cl N AG THER THAN NASA FROM: -LAURAAULETTA CHAIR CIVILIAN AGENCY ACQUISITION COUNCIL (CAAC) SUBJECT: Class Deviation from the Federal Acquisition Regulation (FAR) to Remove the Dollar Limitation for Set-asides under the Women- owned Small Business (WOSB) Program Section 1697 of the National Defense Authorization Act (NDAA) for Fiscal Year (FY) 2013, Public Law 112-239, amended section 8(m) of the Small Business Act, (15

  17. Do financial investors destabilize the oil price?

    Gasoline and Diesel Fuel Update (EIA)

    ... Moreover, we test whether the ine cient ...nancial trading shock (iii) increased the ... To test for this, we generate the variance decomposition and the historical decomposition ...

  18. Microsoft Word - PNNL 24125 Probative Investigation of the Thermal...

    Office of Environmental Management (EM)

    ... Cronin, JT, et al. 1988. "Thermal decomposition of energetic materials 29-The fast thermal decomposition characteristics of a multicomponent material: liquid gun propellant 1845". ...

  19. Microsoft Word - Analysis WIPP Samples Integrated Summary Report...

    Office of Environmental Management (EM)

    ... Brill, T. B. Thermal Decomposition of Energetic Materials 29- The Fast Thermal Decomposition of Characteristics of a Multicomponent Material: Liquid Gun Propellant 1845. Combust. ...

  20. Water-splitting using photocatalytic porphyrin-nanotube composite devices

    DOE Patents [OSTI]

    Shelnutt, John A. (Tijeras, NM); Miller, James E. (Albuquerque, NM); Wang, Zhongchun (Albuquerque, NM); Medforth, Craig J. (Winters, CA)

    2008-03-04

    A method for generating hydrogen by photocatalytic decomposition of water using porphyrin nanotube composites. In some embodiments, both hydrogen and oxygen are generated by photocatalytic decomposition of water.

  1. Slide 1

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

    functional theory (DFT) calculations of ethylene glycol decomposition on Pt(111) and NiPt(111) reveal key differences between decomposition of highly functionalized oxygenates...

  2. A I K E N

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

    Donates Collection for Education AIKEN, S.C. (May 12, 2014) - When Dr. Carol Jantzen was just one year old; her fa- ther gave her a mineral pick. Even though she was barely able to hold the tool, it sparked a lifelong interest in rocks, minerals and fos- sils. Jantzen is now a Materials Scientist and Geochemist at the Savannah River National Laboratory (SRNL) and has donated her ex- tensive mineral collection to the Ruth Patrick Science Education Center at the University of South Carolina -

  3. ORNL/RASA-85/

    Office of Legacy Management (LM)

    e?Ll ( U o't /u/ / ORNL/RASA-85/ 4I 4 RESULTS 0FRADI0L0GICALMEASUREMENTSTMENNEA OF BUFFALO AVENUE A'ID HYffi PARK BLVD. IN NIAGARA FALLS' NET{ YORK Access to the inlormation in thit rtport ir limitcd to tho!' ino-icateo on tha distribution list and to oepartmsnt of Encrgy tnd Oepartment ol Enoqy Contracton F This report was prepared as an accountof work sponsored by an agency of the UnitedstatesGovernment.NeithertheUnitedstatesGovernmentnoranyagency thereo|, nor any o| the.r employees, makes any

  4. Tax Credits, Rebates & Savings | Department of Energy

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

    wind, solid waste, decomposition of organic wastes, geothermal, small hydropower plants, low-emission wood or... Eligibility: Commercial, Industrial, Residential,...

  5. INDDGO

    Energy Science and Technology Software Center (OSTI)

    002861MLTPL00 Integrated Network Decompositions and Dynamic Programming for Graph Optimization (INDDGO) http://github.org/bdsullivan/INDDGO

  6. Tax Credits, Rebates & Savings | Department of Energy

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

    waste, decomposition of organic wastes, geothermal, small hydropower plants, low-emission wood or... Eligibility: Commercial, Industrial, Residential, Agricultural, Multifamily...

  7. Tax Credits, Rebates & Savings | Department of Energy

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

    decomposition of organic wastes, geothermal, small hydropower plants, low-emission wood or... Eligibility: Commercial, Industrial, Residential, Agricultural, Multifamily...

  8. Tax Credits, Rebates & Savings | Department of Energy

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

    Technologies Renewable Energy Systems Exemption Recognized forms of energy generation include solar photovoltaics, passive solar, wind, solid waste, decomposition of...

  9. Tax Credits, Rebates & Savings | Department of Energy

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

    waste, decomposition of organic wastes, geothermal, small hydropower plants, low-emission wood or... Eligibility: Commercial, Industrial, Residential, Agricultural,...

  10. Nanosecond Time Resolved and Steady State Infrared Studies of Photoinduced

    Office of Scientific and Technical Information (OSTI)

    Decomposition of TATB at Ambient and Elevated Pressures (Journal Article) | SciTech Connect Journal Article: Nanosecond Time Resolved and Steady State Infrared Studies of Photoinduced Decomposition of TATB at Ambient and Elevated Pressures Citation Details In-Document Search Title: Nanosecond Time Resolved and Steady State Infrared Studies of Photoinduced Decomposition of TATB at Ambient and Elevated Pressures The timescale and/or products of photo-induced decomposition of

  11. NATIONAL GEOTHERMAL DATA SYSTEM (NGDS) GEOTHERMAL DATA DOMAIN: ASSESSMENT OF GEOTHERMAL COMMUNITY DATA NEEDS

    SciTech Connect (OSTI)

    Anderson, Arlene; Blackwell, David; Chickering, Cathy; Boyd, Toni; Horne, Roland; MacKenzie, Matthew; Moore, Joseph; Nickull, Duane; Richard, Stephen; Shevenell, Lisa A.

    2013-01-01

    To satisfy the critical need for geothermal data to ad- vance geothermal energy as a viable renewable ener- gy contender, the U.S. Department of Energy is in- vesting in the development of the National Geother- mal Data System (NGDS). This paper outlines efforts among geothermal data providers nationwide to sup- ply cutting edge geo-informatics. NGDS geothermal data acquisition, delivery, and methodology are dis- cussed. In particular, this paper addresses the various types of data required to effectively assess geother- mal energy potential and why simple links to existing data are insufficient. To create a platform for ready access by all geothermal stakeholders, the NGDS in- cludes a work plan that addresses data assets and re- sources of interest to users, a survey of data provid- ers, data content models, and how data will be ex- changed and promoted, as well as lessons learned within the geothermal community.

  12. Accelerating Geothermal Research (Fact Sheet), NREL (National Renewable Energy Laboratory)

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

    Accelerating Geothermal Research Supporting a Cleaner Environment NREL is a strategic partner of the U.S. Department of Energy (DOE) Geothermal Technologies Office (GTO). NREL teams are leading the research and deployment efforts through various projects. Summaries of a few key activities follow. Geothermal-Solar Hybrids: The objective is to examine the viability of using solar thermal heat combined with geother- mal energy to improve plant efficiency and reduce cost. This project, performed by

  13. Supporting Advanced Scientific Computing Research * Basic Energy Sciences * Biological

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

    Energy S ciences N etwork Enabling Virtual Science June 9, 2009 Steve C o/er steve@es.net Dept. H ead, E nergy S ciences N etwork Lawrence B erkeley N aDonal L ab The E nergy S ciences N etwork The D epartment o f E nergy's O ffice o f S cience i s o ne o f t he l argest s upporters o f basic r esearch i n t he p hysical s ciences i n t he U .S. * Directly s upports t he r esearch o f s ome 1 5,000 s cienDsts, p ostdocs a nd g raduate s tudents at D OE l aboratories, u niversiDes, o ther F

  14. Shreyas Cholia!

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

    Data and Analytics Services! NUG 2014! Data Transfer at NERSC --- 1 --- February 3 rd , 2014 What are the Data Transfer Nodes? * The D ata T ransfer N odes ( DTN) a re s ervers dedicated t o d ata t ransfer a t N ERSC. - Nodes - d tn[01---04].nersc.gov * DTNs h ave a ccess t o m ost o f t he N ERSC fi le systems, and are tuned to transfer data efficiently. * The D ata T ransfer N odes a re t uned f or t ransferring large v olumes o f d ata b etween N ERSC a nd o ther major f aciliJes ( ORNL, A

  15. MODEL REDUCTION WITH MAPREDUCE-ENABLED TALL AND SKINNY SINGULAR VALUE

    Office of Scientific and Technical Information (OSTI)

    DECOMPOSITION. (Journal Article) | SciTech Connect Journal Article: MODEL REDUCTION WITH MAPREDUCE-ENABLED TALL AND SKINNY SINGULAR VALUE DECOMPOSITION. Citation Details In-Document Search Title: MODEL REDUCTION WITH MAPREDUCE-ENABLED TALL AND SKINNY SINGULAR VALUE DECOMPOSITION. Abstract not provided. Authors: Templeton, Jeremy Alan ; Constantine, Paul G. ; Gleich, David F. ; Hou, Yangyang Publication Date: 2013-06-01 OSTI Identifier: 1110659 Report Number(s): SAND2013-4939J 456438 DOE

  16. Silver-Mordenite for Radiologic Gas Capture from Complex Streams: Dual

    Office of Scientific and Technical Information (OSTI)

    Catalytic CH3I Decomposition and I Confinement (Journal Article) | SciTech Connect Journal Article: Silver-Mordenite for Radiologic Gas Capture from Complex Streams: Dual Catalytic CH3I Decomposition and I Confinement Citation Details In-Document Search Title: Silver-Mordenite for Radiologic Gas Capture from Complex Streams: Dual Catalytic CH3I Decomposition and I Confinement The effective capture and storage of radiological iodine (129I) remains a strong concern for safe nuclear waste

  17. Using RSI format

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

    ... Fourier decomposition is employed to extract the toroi- dal harmonics of the magnetic ... By correlating the density fluctuations with individual toroidal harmonics of the magnetic ...

  18. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    permafrost soils of boreal forest ecosystems, where it is currently protected from decomposition. The surface organic horizons insulate the deeper soil from variations in...

  19. Tax Credits, Rebates & Savings | Department of Energy

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

    of energy generation include solar photovoltaics, passive solar, wind, solid waste, decomposition of organic wastes, geothermal, small hydropower plants, low-emission wood or......

  20. Final Technical Report to DOE for the Award DE-SC0004601 (Technical...

    Office of Scientific and Technical Information (OSTI)

    mechanistic understanding of the temperature sensitivity of soil carbon (C) decomposition to climate warming by using cutting-edge integrated metagenomic technologies....

  1. Consortium for Advanced Simulation of Light Water Reactors (CASL...

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

    The toolkit also provides run-time parallel domain decomposition with data-migration for both static and dynamic load-balancing. Linear algebra is handled through an...

  2. Tax Credits, Rebates & Savings | Department of Energy

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

    Renewable Energy Systems Exemption Recognized forms of energy generation include solar photovoltaics, passive solar, wind, solid waste, decomposition of organic wastes,...

  3. Process for remediation of plastic waste

    DOE Patents [OSTI]

    Pol, Vilas G; Thiyagarajan, Pappannan

    2013-11-12

    A single step process for degrading plastic waste by converting the plastic waste into carbonaceous products via thermal decomposition of the plastic waste by placing the plastic waste into a reactor, heating the plastic waste under an inert or air atmosphere until the temperature of about 700.degree. C. is achieved, allowing the reactor to cool down, and recovering the resulting decomposition products therefrom. The decomposition products that this process yields are carbonaceous materials, and more specifically carbon nanotubes having a partially filled core (encapsulated) adjacent to one end of the nanotube. Additionally, in the presence of a transition metal compound, this thermal decomposition process produces multi-walled carbon nanotubes.

  4. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... LLC New Brunswick Laboratory (NBL), Argonne, IL (United States) New York ... (1) corrosion (1) decomposition (1) evaluation (1) flowsheets (1) forecasting (1) ...

  5. Tax Credits, Rebates & Savings | Department of Energy

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

    forms of energy generation include solar photovoltaics, passive solar, wind, solid waste, decomposition of organic wastes, geothermal, small hydropower plants, low-emission...

  6. Tax Credits, Rebates & Savings | Department of Energy

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

    Geothermal Direct-Use Renewable Energy Systems Exemption Recognized forms of energy generation include solar photovoltaics, passive solar, wind, solid waste, decomposition of...

  7. Tax Credits, Rebates & Savings | Department of Energy

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

    Cells using Renewable Fuels Renewable Energy Systems Exemption Recognized forms of energy generation include solar photovoltaics, passive solar, wind, solid waste, decomposition of...

  8. Tax Credits, Rebates & Savings | Department of Energy

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

    passive solar, wind, solid waste, decomposition of organic wastes, geothermal, small hydropower plants, low-emission wood or... Eligibility: Commercial, Industrial, Residential,...

  9. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... decomposition of water into hydrogen gas using ultraviolet and visible solar radiation. ... TaON is considered as a potential candidate as a visible-light responsive photocatalyst. ...

  10. Tax Credits, Rebates & Savings | Department of Energy

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

    Fuels, Microturbines Renewable Energy Systems Exemption Recognized forms of energy generation include solar photovoltaics, passive solar, wind, solid waste, decomposition of...

  11. Tax Credits, Rebates & Savings | Department of Energy

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

    Hydroelectric (Small) Renewable Energy Systems Exemption Recognized forms of energy generation include solar photovoltaics, passive solar, wind, solid waste, decomposition of...

  12. Tax Credits, Rebates & Savings | Department of Energy

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

    Energy Systems Exemption Recognized forms of energy generation include solar photovoltaics, passive solar, wind, solid waste, decomposition of organic wastes, geothermal,...

  13. Tax Credits, Rebates & Savings | Department of Energy

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

    Exemption Recognized forms of energy generation include solar photovoltaics, passive solar, wind, solid waste, decomposition of organic wastes, geothermal, small hydropower plants,...

  14. Tax Credits, Rebates & Savings | Department of Energy

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

    Energy Systems Exemption Recognized forms of energy generation include solar photovoltaics, passive solar, wind, solid waste, decomposition of organic wastes, geothermal, small...

  15. Tax Credits, Rebates & Savings | Department of Energy

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

    Systems Exemption Recognized forms of energy generation include solar photovoltaics, passive solar, wind, solid waste, decomposition of organic wastes, geothermal, small hydropower...

  16. Tax Credits, Rebates & Savings | Department of Energy

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

    Recognized forms of energy generation include solar photovoltaics, passive solar, wind, solid waste, decomposition of organic wastes, geothermal, small hydropower plants,...

  17. Process for remediation of plastic waste

    DOE Patents [OSTI]

    Pol, Vilas G. (Westmont, IL); Thiyagarajan, Pappannan (Germantown, MD)

    2012-04-10

    A single step process for degrading plastic waste by converting the plastic waste into carbonaceous products via thermal decomposition of the plastic waste by placing the plastic waste into a reactor, heating the plastic waste under an inert or air atmosphere until the temperature of 700.degree. C. is achieved, allowing the reactor to cool down, and recovering the resulting decomposition products therefrom. The decomposition products that this process yields are carbonaceous materials, and more specifically egg-shaped and spherical-shaped solid carbons. Additionally, in the presence of a transition metal compound, this thermal decomposition process produces multi-walled carbon nanotubes.

  18. Tax Credits, Rebates & Savings | Department of Energy

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

    Systems Exemption Recognized forms of energy generation include solar photovoltaics, passive solar, wind, solid waste, decomposition of organic wastes, geothermal, small...

  19. The microbe-mediated mechanisms affecting topsoil carbon stock...

    Office of Scientific and Technical Information (OSTI)

    affecting topsoil carbon stock in Tibetan grasslands Warming has been shown to cause soil carbon (C) loss in northern grasslands owing to accelerated microbial decomposition...

  20. Renewable Energy Systems Exemption

    Broader source: Energy.gov [DOE]

    Recognized forms of energy generation include solar photovoltaics, passive solar, wind, solid waste, decomposition of organic wastes, geothermal, small hydropower plants, low-emission wood or...

  1. Visapult: A Prototype Remote and Distributed Visualization Application...

    Office of Scientific and Technical Information (OSTI)

    Our approach uses a pipelined-parallel decomposition composed of parallel computers and commodity desktop hardware. With our approach, desktop interactivity is divorced from the ...

  2. Computational and experimental techniques for coupled acoustic...

    Office of Scientific and Technical Information (OSTI)

    Domain decomposition and diagonal scaling preconditioners were investigated for parallel implementation. A formulation that includes fluid viscosity and that can simulate both ...

  3. Tax Credits, Rebates & Savings | Department of Energy

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

    Renewable Energy Systems Exemption Recognized forms of energy generation include solar photovoltaics, passive solar, wind, solid waste, decomposition of organic wastes, geothermal,...

  4. What Does? Scalable Resilience? Look Like

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

    Models 4 A Runtime System based on Over-decomposition and Migratability can support resilience effetively Runtime Systems can play a role * RTS based solutions to resilience are...

  5. Task Technical Plan for Studies of Oxygen Consumption in the Catalyzed Hydrolysis of Tetraphenylborate Ion

    SciTech Connect (OSTI)

    Fink, S.D.

    1996-12-20

    This document presents the plan for studies of how dissolved oxygen affects the catalytic decomposition of the tetraphenylborate ion in alkaline aqueous solution.

  6. Lawrence Livermore National Laboratory, P. O. Box

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

    Lawrence Livermore National Laboratory, P. O. Box 808, Livermore, CA 94551 Case Case Study DDCMP: Beyond Homogeneous Decomposition with ddcMD Scaling Long-Range Forces on...

  7. ARM - Publications: Science Team Meeting Documents: Advantages...

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

    an alternative T-mode decomposition. Whereas S-mode representation analyzes a dispersion matrix of inter-station covariancescorrelations, T-mode analysis transposes the...

  8. Nanosecond Time Resolved and Steady State Infrared Studies of...

    Office of Scientific and Technical Information (OSTI)

    Nanosecond Time Resolved and Steady State Infrared Studies of Photoinduced Decomposition of TATB at Ambient and Elevated Pressures Citation Details In-Document Search Title:...

  9. Tax Credits, Rebates & Savings | Department of Energy

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

    using Renewable Fuels Renewable Energy Systems Exemption Recognized forms of energy generation include solar photovoltaics, passive solar, wind, solid waste, decomposition of...

  10. PROBING THE INTERSTELLAR MEDIUM OF z {approx} 1 ULTRALUMINOUS...

    Office of Scientific and Technical Information (OSTI)

    The mid-IR spectra show strong polycyclic aromatic hydrocarbon (PAH) emission, and our spectral decomposition suggests that the AGN makes a minimal contribution (<25%) to the ...

  11. Tax Credits, Rebates & Savings | Department of Energy

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

    include solar photovoltaics, passive solar, wind, solid waste, decomposition of organic wastes, geothermal, small hydropower plants, low-emission wood or... Eligibility:...

  12. Method of manufacturing aerogel composites

    DOE Patents [OSTI]

    Cao, W.; Hunt, A.J.

    1999-03-09

    Disclosed herewith is a process of forming an aerogel composite which comprises introducing a gaseous material into a formed aerogel monolith or powder, and causing decomposition of said gaseous material in said aerogel in amounts sufficient to cause deposition of the decomposition products of the gas on the surfaces of the pores of the said aerogel.

  13. Method and apparatus for maintaining the pH in zinc-bromine battery systems

    DOE Patents [OSTI]

    Grimes, Patrick G.

    1985-09-10

    A method and apparatus for maintaining the pH level in a zinc-bromine battery features reacting decomposition hydrogen with bromine in the presence of a catalyst. The catalyst encourages the formation of hydrogen and bromine ions. The decomposition hydrogen is therefore consumed, alloying the pH of the system to remain substantially at a given value.

  14. Method of manufacturing aerogel composites

    DOE Patents [OSTI]

    Cao, Wanqing (Alameda, CA); Hunt, Arlon Jason (Oakland, CA)

    1999-01-01

    Disclosed herewith is a process of forming an aerogel composite which comprises introducing a gaseous material into a formed aerogel monolith or powder, and causing decomposition of said gaseous material in said aerogel in amounts sufficient to cause deposition of the decomposition products of the gas on the surfaces of the pores of the said aerogel.

  15. Benzene distribution in product streams from in-tank processing

    SciTech Connect (OSTI)

    Walker, D.D.

    1987-01-15

    Benzene is the major product of radiolytic decomposition of tetraphenylborate salts during in-tank salt decontamination. Its production rate has been measured at the Savannah River Laboratory (SR) and at the University of Florida under various conditions of importance to the in-tank process. Recent work has been concerned with the extent of decomposition for long storage periods, and the composition of the product streams from the process. The major results from this work are: the stored potassium tetraphenylborate precipitate will decompose at a rate of 7.3 {plus minus} 1.1% per year; the major products of the decomposition are benzene, phenol, biphenyl, and phenylboric acid; decomposition is directly proportional to the total dose and is unaffected by dose rate; the decomposition produces acidic compounds which will cause a decrease in the pH of the storage tank. 13 refs., 6 figs., 6 tabs.

  16. SUSANA MARTINEZ Governor JOHN A. SANCHEZ Lieutenant Governor

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

    ENVlRONMENTDEPARTMENT Hazardous Waste Bureau 2905 Rodeo Park Drive East, Building 1 Santa Fe, New Mexico 87505-6303 Phone (505) 476-6000 Fax (505) 476-6030 IVww.nmenv.state.nm.us DAVE MARTIN Secretary BUTCH TONGATE Deputy Secretary CERTIFIED MAlL - RETURN RECEIPT REQUESTED May 30,2012 Jose R. Franco, Manager Carlsbad Field Office Department of Energy P. O. Box 3090 Carlsbad, New Mexico 88221-3090 M. FarokSharif Washington TRU Solutions LLC P. O. Box 2078 Carlsbad, New Mexico 88221-5608 RE:

  17. pLS010 plasmid vector

    DOE Patents [OSTI]

    Lacks, Sanford A. (Brookhaven, NY); Balganesh, Tanjore S. (Upton, NY)

    1988-01-01

    Disclosed is recombinant plasmid pLS101, consisting essentially of a 2.0 Kb malM gene fragment ligated to a 4.4 Kb T.sub.c r DNA fragment, which is particularly useful for transforming Gram-positive bacteria. This plasmid contains at least four restriction sites suitable for inserting exogeneous gene sequences. Also disclosed is a method for plasmid isolation by penicillin selection, as well as processes for enrichment of recombinant plasmids in Gram-positive bacterial systems.

  18. Introduction

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

    diverse and complex mosaic of plant and animal communities are found at the Nevada National Security Site. Representative of both the Mojave and Great Basin deserts, approximately 1,500 ani- mal species, including 924 species of insects, and 750 different kinds of plants are documented at the site. The varying elevations and climatic conditions at the test site contribute to the distribution of plant and animal communities. On the south end of the site, Jackass Flats lies at a low 2,688 feet

  19. dI UNIVERSITY OF NEV\DA SYSTEM

    Office of Legacy Management (LM)

    g3t4 6 dI UNIVERSITY OF NEV\DA SYSTEM tw ?r@ D O E / D P / O 1 2 6 3 - 2 0 L , n z l t P ' " WATER RESOURCES CENTER itf.l This report was prepared as an aecount of work sponsore$ by the United States Government. Neither the United States nor the United States Department of Energy, nor any of their employees, mal assumes any legal liability or responsib usefulness of any informationr apparatus' I that its use would not infringe privately speeifie eommereial produetr proeesst ufacturen, or

  20. ; United States Government

    Office of Legacy Management (LM)

    Don F 1328.8 . . .449J ' Em wm ; United States Government , % - memorandum L c*m Al.)G 2 9 a34 yz;; EM-421 (If. A. Willlams, 427-1719) lq,iMAL Department of Energy m5 MA, \i& SUBJECT: Elimination of the Sites from the Formerly Utllized Sites Remedial A&Ion Prograa ' a The File In 1990, with the assistance of Hr. Doug Tonkay and Ms. Htchelle L&is, I reviewed a number of sites that had fomerly provided goods and/or services to the Fernald faclllty as subcontractors. For 24 of.these

  1. l[nterial &oratory the New York h'

    Office of Legacy Management (LM)

    l[nterial &oratory the New York h' ar&l Shipyard at Br&lyn, N. Y., to measure the neutron absorption chaxteristics ?f Tarious oyerlayys of fibergla& and resinous materials. R~TC&S Powder Co., Wilmington, Del., applied for a licerw to re- ceive and possess 25 gram3 of umnium (20 percent enrichment in uwnium 235) in the form of uranyl nitrate, for radiation chemistry osperiments. MalZnckrodt Chanical1Vork.q St. Low& ;Ilo., applied for 3 license to receive nnd possessup to

  2. T PamI J. I(. u!borekl

    Office of Legacy Management (LM)

    mr a. L. khbert - mchn:aal Director T PamI J. I(. u!borekl r&&r r.B.0. Produotlon Order Eo. 304 Sat' ional Lead Ia to furnieh Brld&eporf- Braem Company In Adrian, Ulchlmm, aachlned hollow &rtmelon bllleto for uev.;;: in prodaoing extruded hollow urenlum rod etodb , The extrwlon program oos ' . aleta of two parts; one, fabrloetion of nowal uranium hollow extrusion billet8 iroa WOW lqote and, two. fkbrlcatlon of both $10~ urenlm and n0ma.l ?reninm hollow extrusion billet8 from

  3. Relation between combustion heat and chemical wood composition during white and brown rot

    SciTech Connect (OSTI)

    Dobry, J.; Dziurzynski, A.; Rypacek, V.

    1986-01-01

    Samples of beech and spruce wood were incubated with the white rot fungi Pleurotus ostreatus and Lentinus tigrinus and the brown rot fungi Fomitopsis pinicola and Serpula lacrymans (S. lacrimans) for four months. Decomposition (expressed as percent weight loss) and amounts of holocellulose, lignin, humic acids (HU), hymatomelanic acids (HY) and fulvo acids (FU) were determined and expressed in weight percent. Combustion heat of holocellulose and lignin was determined in healthy wood and in specimens where decomposition was greater than 50%. During white rot decomposition, combustion heat was unchanged even at high decomposition and the relative amounts of holocellulose and lignin remained the same. Total amounts of HU, HY and FU increased during the initial stages and stabilized at 20%. The content of HU plus HY was negligible even at the highest degree of decomposition. During brown rot decomposition, combustion heat was unchanged only in the initial stages, it increased continously with increasing rot. Lignin content was unchanged in the initial stages and increased after 30% weight loss. Total amounts of HU, HY and FU increased continuously, reaching higher values than in white rot decomposition; there were differences between the two species. Biosynthesis of HU plus HY began when weight loss reached 30%; there were differences in absolute and relative amounts between species. 24 references.

  4. Anaerobic High-Throughput Cultivation Method for Isolation of Thermophiles Using Biomass-Derived Substrates

    SciTech Connect (OSTI)

    Hamilton-Brehm, Scott; Vishnivetskaya, Tatiana A; Allman, Steve L; Mielenz, Jonathan R; Elkins, James G

    2012-01-01

    Flow cytometry (FCM) techniques have been developed for sorting mesophilic organisms, but the difficulty increases if the target microbes are thermophilic anaerobes. We demonstrate a reliable, high-throughput method of screening thermophilic anaerobic organisms using FCM and 96-well plates for growth on biomass-relevant substrates. The method was tested using the cellulolytic thermophiles Clostridium ther- mocellum (Topt = 55 C), Caldicellulosiruptor obsidiansis (Topt = 78 C) and the fermentative hyperthermo- philes, Pyrococcus furiosus (Topt = 100 C) and Thermotoga maritima (Topt = 80 C). Multi-well plates were incubated at various temperatures for approximately 72 120 h and then tested for growth. Positive growth resulting from single cells sorted into individual wells containing an anaerobic medium was verified by OD600. Depending on the growth substrate, up to 80 % of the wells contained viable cultures, which could be transferred to fresh media. This method was used to isolate thermophilic microbes from Rabbit Creek, Yellowstone National Park (YNP), Wyoming. Substrates for enrichment cultures including crystalline cellulose (Avicel), xylan (from Birchwood), pretreated switchgrass and Populus were used to cultivate organisms that may be of interest to lignocellulosic biofuel production.

  5. CX-010329: Categorical Exclusion Determination

    Office of Energy Efficiency and Renewable Energy (EERE)

    Thermal-Chemical Decomposition of Graphite CX(s) Applied: B3.6 Date: 04/04/2013 Location(s): South Carolina Offices(s): Savannah River Operations Office

  6. CX-011510: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Thermal-Chemical Decomposition of Graphite CX(s) Applied: B3.6 Date: 10/17/2013 Location(s): South Carolina Offices(s): Savannah River Operations Office

  7. Nanocatalytic Conversion of Biomass into Second-Generation Biofuels

    SciTech Connect (OSTI)

    2009-04-01

    This factsheet describes a study whose focus is on unconventional feedstocks for ansportation fuel and commodity chemicals, primarily lignin, testing novel nanocatalytic pathways for the decomposition of refractory materials into useful building block chemicals.

  8. Porphyrins and metal complexes thereof having haloalkyl side chains

    DOE Patents [OSTI]

    Wijesekera, T.; Lyons, J.E.; Ellis, P.E. Jr.; Bhinde, M.V.

    1997-03-04

    Transition metal complexes of meso-haloalkylporphyrins, wherein the haloalkyl groups contain 2 to 8 carbon atoms have been found to be highly effective catalysts for oxidation of alkanes and for the decomposition of hydroperoxides. 7 figs.

  9. Porphyrins and metal complexes thereof having haloalkyl side chains

    DOE Patents [OSTI]

    Wijesekera, Tilak; Lyons, James E.; Ellis, Jr., Paul E.; Bhinde, Manoj V.

    1997-01-01

    Transition metal complexes of meso-haloalkylporphyrins, wherein the haloalkyl groups contain 2 to 8 carbon atoms have been found to be highly effective catalysts for oxidation of alkanes and for the decomposition of hydroperoxides.

  10. Alkane oxidation with porphyrins and metal complexes thereof having haloalkyl side chains

    DOE Patents [OSTI]

    Wijesekera, Tilak; Lyons, James E.; Ellis, Jr., Paul E.; Bhinde, Manoj V.

    1998-01-01

    Transition metal complexes of meso-haloalkylporphyrins, wherein the haloalkyl groups contain 2 to 8 carbon atoms have been found to be highly effective catalysts for oxidation of alkanes and for the decomposition of hydroperoxides.

  11. Alkane oxidation with porphyrins and metal complexes thereof having haloalkyl side chains

    DOE Patents [OSTI]

    Wijesekera, T.; Lyons, J.E.; Ellis, P.E. Jr.; Bhinde, M.V.

    1998-06-23

    Transition metal complexes of meso-haloalkylporphyrins are disclosed, wherein the haloalkyl groups contain 2 to 8 carbon atoms have been found to be highly effective catalysts for oxidation of alkanes and for the decomposition of hydroperoxides. 7 figs.

  12. Method of depositing buffer layers on biaxially textured metal...

    Office of Scientific and Technical Information (OSTI)

    eu; gd; tb; tm; resup1subx; resup2sub1-xsub2; osub3; buffer; layer; deposited; sol-gel; metal-organic; decomposition; laminate; article; layer; ybco; resup1subx; ...

  13. CX-012288: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Development of Reduced-Order Model for Gas-Solid Flow Using Proper Orthogonal Decomposition CX(s) Applied: A9 Date: 06/05/2014 Location(s): Texas Offices(s): National Energy Technology Laboratory

  14. CX-012287: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Development of Reduced-Order Model for Gas-Solid Flow Using Proper Orthogonal Decomposition CX(s) Applied: A9 Date: 06/05/2014 Location(s): Florida Offices(s): National Energy Technology Laboratory

  15. Flash photolysis-shock tube studies

    SciTech Connect (OSTI)

    Michael, J.V.

    1993-12-01

    Even though this project in the past has concentrated on the measurement of thermal bimolecular reactions of atomic species with stable molecules by the flash or laser photolysis-shock tube (FP- or LP-ST) method using atomic resonance absorption spectrometry (ARAS) as the diagnostic technique, during the past year the authors have concentrated on studies of the thermal decompositions of selected chlorocarbon molecules. These studies are necessary if the degradation of chlorine containing organic molecules by incineration are to be understood at the molecular level. Clearly, destruction of these molecules will not only involve abstraction reactions, when possible, but also thermal decomposition followed by secondary reactions of the initially formed atoms and radicals. Studies on the thermal decomposition of CH{sub 3}Cl are complete, and the curve-of-growth for Cl-atom atomic resonance absorption has been determined. The new thermal decomposition studies are similar to those already reported for CH{sub 3}Cl.

  16. RussiaLANLV3-web.indd

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

    Heterogeneous decomposition Radius, mm 2 1 0 Radius, mm 2 1 0 Radius, mm Aluminum Copper Modifi ed for the Web The task will be performed in two stages. In the fi rst stage (fi rst ...

  17. RussiaSNL2-web.indd

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

    ... On-Line FTIR Condenser Reactor Schematic large sample thermal decomposition. Modifi ed for the Web The project has signifi cantly benefi ted USDP, ASC, and the Russian Federation, ...

  18. S10: Scaling to Petascale and Beyond: Performance Analysis and...

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

    Don Frederick, LLNL IntrotoPetascaleDF-ddcMD.11.14.11.pdf | Adobe Acrobat PDF file Case Case Study DDCMP: Beyond Homogeneous Decomposition with ddcMD, Don Frederick, LLNL...

  19. Liquid composition having ammonia borane and decomposing to form hydrogen and liquid reaction product

    DOE Patents [OSTI]

    Davis, Benjamin L; Rekken, Brian D

    2014-04-01

    Liquid compositions of ammonia borane and a suitably chosen amine borane material were prepared and subjected to conditions suitable for their thermal decomposition in a closed system that resulted in hydrogen and a liquid reaction product.

  20. Method for preparing thermally cleavable surfactants without deprotonation

    DOE Patents [OSTI]

    McElhanon, James R. (Manteca, CA); Jamison, Gregory M. (Albuquerque, NM); Long, Timothy M. (Evanston, IL); Loy, Douglas A. (Tucson, AZ); Rahimian, Kamyar (Albuquerque, NM); Simmons, Blake A. (San Francisco, CA); Staiger, Chad L. (Albuquerque, NM); Wheeler, David R. (Albuquerque, NM); Zifer, Thomas (Manteca, CA)

    2008-05-27

    The present invention describes surfactants of formula (I), ##STR00001## wherein R, R.sub.N, and m are defined herein, processes for their preparation, and methods for their decomposition.

  1. Thermally cleavable surfactants without deprotonation

    DOE Patents [OSTI]

    McElhanon, James R. (Manteca, CA); Jamison, Gregory M. (Albuquerque, NM); Long, Timothy M. (Evanston, IL); Loy, Douglas A. (Tucson, AZ); Rahimian, Kamyar (Albuquerque, NM); Simmons, Blake A. (San Francisco, CA); Staiger, Chad L. (Albuquerque, NM); Wheeler, David R. (Albuquerque, NM); Zifer, Thomas (Manteca, CA)

    2008-04-01

    The present invention describes surfactants of formula (I), ##STR00001## wherein R, R.sub.N, and m are defined herein, processes for their preparation, and methods for their decomposition.

  2. Harnessing the Bacterial Power of Nanomagnets

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

    and 23 atom % Co (bottom). Right: The decomposition of the XMCD spectra into the Fe2+ Oh (purple), Fe3+ Td (blue), and Fe3+ Oh (green) components. The color-coded numbers indicate...

  3. Ni-Si Alloys for the S-I Reactor-Hydrogen Production Process Interface

    SciTech Connect (OSTI)

    Joseph W. Newkirk; Richard K. Brow

    2010-01-21

    The overall goal of this project was to develop Ni-Si alloys for use in vessels to contain hot, pressurized sulfuric acid. The application was to be in the decomposition loop of the thermochemical cycle for production of hydrogen.

  4. Modeling the effects of fire severity and climate warming on...

    Office of Scientific and Technical Information (OSTI)

    in permafrost to decomposition. In this study we ask how warming and fire regime may influence spatial and temporal changes in active layer and carbon dynamics across a boreal...

  5. My Title

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

    John C. Wagner and Scott W. Mosher and Thomas M. Evans and Douglas E. Peplow and John A. Turner (2011). Hybrid and Parallel Domain-Decomposition Methods Development to Enable...

  6. Adventures on the C3H5O potential energy surface: OH+propyne...

    Office of Scientific and Technical Information (OSTI)

    for the bimolecular reactions propyne + OH and allene + OH, and for the unimolecular decomposition of the CH3CCHOH, CH3C(OH)CH, CH2CCH2OH, CH2C(OH)CH2 primary adducts, ...

  7. Aerogel composites and method of manufacture

    DOE Patents [OSTI]

    Cao, Wanqing (Alameda, CA); Hunt, Arlon Jason (Oakland, CA)

    1999-01-01

    Disclosed herewith is a process of forming an aerogel composite which comprises introducing a gaseous material into a formed aerogel monolith or powder, and causing decomposition of said gaseous material in said aerogel in amounts sufficient to cause deposition of the decomposition products of the gas on the surfaces of the pores of the said aerogel. Also disclosed are the composites made by the process.

  8. ACTUAL-WASTE TESTING OF ULTRAVIOLET LIGHT TO AUGMENT THE ENHANCED CHEMICAL CLEANING OF SRS SLUDGE

    SciTech Connect (OSTI)

    Martino, C.; King, W.; Ketusky, E.

    2012-07-10

    In support of Savannah River Site (SRS) tank closure efforts, the Savannah River National Laboratory (SRNL) conducted Real Waste Testing (RWT) to evaluate Enhanced Chemical Cleaning (ECC), an alternative to the baseline 8 wt% oxalic acid (OA) chemical cleaning technology for tank sludge heel removal. ECC utilizes a more dilute OA solution (2 wt%) and an oxalate destruction technology using ozonolysis with or without the application of ultraviolet (UV) light. SRNL conducted tests of the ECC process using actual SRS waste material from Tanks 5F and 12H. The previous phase of testing involved testing of all phases of the ECC process (sludge dissolution, OA decomposition, product evaporation, and deposition tank storage) but did not involve the use of UV light in OA decomposition. The new phase of testing documented in this report focused on the use of UV light to assist OA decomposition, but involved only the OA decomposition and deposition tank portions of the process. Compared with the previous testing at analogous conditions without UV light, OA decomposition with the use of UV light generally reduced time required to reach the target of <100 mg/L oxalate. This effect was the most pronounced during the initial part of the decomposition batches, when pH was <4. For the later stages of each OA decomposition batch, the increase in OA decomposition rate with use of the UV light appeared to be minimal. Testing of the deposition tank storage of the ECC product resulted in analogous soluble concentrations regardless of the use or non-use of UV light in the ECC reactor.

  9. Solution mining dawsonite from hydrocarbon containing formations with a chelating agent

    DOE Patents [OSTI]

    Vinegar, Harold J. (Bellaire, TX)

    2009-07-07

    A method for treating an oil shale formation comprising dawsonite includes providing heat from one or more heaters to the formation to heat the formation. Hydrocarbon fluids are produced from the formation. At least some dawsonite in the formation is decomposed with the provided heat. A chelating agent is provided to the formation to dissolve at least some dawsonite decomposition products. The dissolved dawsonite decomposition products are produced from the formation.

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

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

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

    2015-06-01

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

  11. Reversible hydrogen storage materials

    DOE Patents [OSTI]

    Ritter, James A. (Lexington, SC); Wang, Tao (Columbia, SC); Ebner, Armin D. (Lexington, SC); Holland, Charles E. (Cayce, SC)

    2012-04-10

    In accordance with the present disclosure, a process for synthesis of a complex hydride material for hydrogen storage is provided. The process includes mixing a borohydride with at least one additive agent and at least one catalyst and heating the mixture at a temperature of less than about 600.degree. C. and a pressure of H.sub.2 gas to form a complex hydride material. The complex hydride material comprises MAl.sub.xB.sub.yH.sub.z, wherein M is an alkali metal or group IIA metal, Al is the element aluminum, x is any number from 0 to 1, B is the element boron, y is a number from 0 to 13, and z is a number from 4 to 57 with the additive agent and catalyst still being present. The complex hydride material is capable of cyclic dehydrogenation and rehydrogenation and has a hydrogen capacity of at least about 4 weight percent.

  12. CILJCU~ATI, QUO J. A. Qu~glw, M

    Office of Legacy Management (LM)

    lo&&-, : i e r : gtdlm FILLS March 12, 1956 ~'RII~~~~~I~~D~.,A~ICAW~~TMDRLBS, CILJCU~ATI, QUO J. A. Qu~glw, M .D. c. E. aahwun ObJcrativr oi THpt On !iUesd8y, Fabmerg 28,19!36, th@ lILQMetallurgMalD@p~rtJmnt beipn bzdquotting green ult-ll( blend on e 350 ton hydmulla prau 8t the Ura &i&nnrlug DivUiou of Ameria8n Steel muUdPae8, c&alMatl, Ohio. Approll'tely a,ooo pound8 of greeu ult ub briqumtte4 bw13ry 8 -rioa of mvea day,. Par the pwpou ofwalutlngexpo88mmmafpemmm8 linrelvmd

  13. James L. Liveman, Acting AssLBtaOt

    Office of Legacy Management (LM)

    1 - * -w : L i P / ' 5- . . . c James L. Liveman, Acting AssLBtaOt Secretay for 2nv??Onnur_nt ( IQ UZT'ZXSI~ OF :ZZ&JA On Dctezher 6, 1977, and ridtcr E. smitil, Edward J . Jaacwsky , De?ar+nent of hrgarme SaCanal Laborawry (AS.), _- _. - - -zatzgy (DOE), visited tlhe University of iJeva&, Ekekay ScMal of %iaes. The purpose ___ was to dLscu!38 tke -8: opcraZ4Qns of tbcse fuCti'I?-'n= **-A-- A e fl' the v?L&gl: ~~ BHIC --c-r &atic . - . dtselopxzeat studies on vsrlous tppes of

  14. Static and dynamic pressure effects on the thermolysis of nitroalkanes in solution

    SciTech Connect (OSTI)

    Brower, K.R. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States). Dept. of Chemistry; Davis, L.L.; Naud, D.L. [Los Alamos National Lab., NM (United States); Wang, J. [Univ. of Southern California, Los Angeles, CA (United States). Dept. of Chemistry

    1998-12-31

    The authors have measured the effects of static and shock-induced pressures on the decomposition rates and mechanisms of various nitroalkanes dissolved in different solvents with and without organic amine catalysts. While nitroalkanes without {alpha}-hydrogen decompose by homolysis of the C-NO{sub 2} bond over a wide range of conditions, the decomposition pathway of nitroalkanes having {alpha}-hydrogens (i.e., acidic nitroalkanes) is complicated and follows different decomposition mechanisms depending on the availability of organic base and reaction pressure. The Nef reaction is also an important reaction pathway. The five known decomposition pathways, homolysis of the C-NO{sub 2} bond, bimolecular reaction between the aci-form and aci-ion, cyclization of the aci-form, elimination of nitrous acid, and the Nef reaction, are highly dependent on the reaction conditions, such as pressure, presence of organic amines, water, alcohols, and polarity of solvent. The authors discuss the results of several tests used to support these various decomposition mechanisms.

  15. Thermal shock resistance ceramic insulator

    DOE Patents [OSTI]

    Morgan, Chester S. (Oak Ridge, TN); Johnson, William R. (Maynardville, TN)

    1980-01-01

    Thermal shock resistant cermet insulators containing 0.1-20 volume % metal present as a dispersed phase. The insulators are prepared by a process comprising the steps of (a) providing a first solid phase mixture of a ceramic powder and a metal precursor; (b) heating the first solid phase mixture above the minimum decomposition temperature of the metal precursor for no longer than 30 minutes and to a temperature sufficiently above the decomposition temperature to cause the selective decomposition of the metal precursor to the metal to provide a second solid phase mixture comprising particles of ceramic having discrete metal particles adhering to their surfaces, said metal particles having a mean diameter no more than 1/2 the mean diameter of the ceramic particles, and (c) densifying the second solid phase mixture to provide a cermet insulator having 0.1-20 volume % metal present as a dispersed phase.

  16. Method for the decontamination of soil containing solid organic explosives therein

    DOE Patents [OSTI]

    Radtke, Corey W. (Idaho Falls, ID); Roberto, Francisco F. (Idaho Falls, ID)

    2000-01-01

    An efficient method for decontaminating soil containing organic explosives ("TNT" and others) in the form of solid portions or chunks which are not ordinarily subject to effective bacterial degradation. The contaminated soil is treated by delivering an organic solvent to the soil which is capable of dissolving the explosives. This process makes the explosives more bioavailable to natural bacteria in the soil which can decompose the explosives. An organic nutrient composition is also preferably added to facilitate decomposition and yield a compost product. After dissolution, the explosives are allowed to remain in the soil until they are decomposed by the bacteria. Decomposition occurs directly in the soil which avoids the need to remove both the explosives and the solvents (which either evaporate or are decomposed by the bacteria). Decomposition is directly facilitated by the solvent pre-treatment process described above which enables rapid bacterial remediation of the soil.

  17. REDUCTION OF ACIDITY OF NITRIC ACID SOLUTIONS BY USE OF FORMALDEHYDE

    DOE Patents [OSTI]

    Healy, T.V.

    1958-05-20

    A continuous method is described of concentrating by evaporation and reducing the nitrate ion content of an aqueous solution of metallic salts containing nitric acid not in excess of 8N. It consists of heating the solution and then passing formaldehyde into the heated solution to bring about decomposition of the nitric acid. The evolved gases containing NO are contacted countercurrently with an aqueous metal salt solution containing nitric acid in excess of 8N so as to bring about decomposition of the nitric acid and lower the normality to at least 8N, whereupon it is passed into the body of heated solution.

  18. Radiolysis Concerns for Water Shielding in Fission Surface Power Applications

    SciTech Connect (OSTI)

    Schoenfeld, Michael P.; Anghaie, Samim

    2008-01-21

    This paper presents an overview of radiolysis concerns with regard to water shields for fission surface power. A review of the radiolysis process is presented and key parameters and trends are identified. From this understanding of the radiolytic decomposition of water, shield pressurization and corrosion are identified as the primary concerns. Existing experimental and modeling data addressing concerns are summarized. It was found that radiolysis of pure water in a closed volume results in minimal, if any net decomposition, and therefore reduces the potential for shield pressurization and corrosion.

  19. Alpha and gamma radioysis of nuclear solvent etxraction ligands used for An(III) and Ln(III) Separations

    SciTech Connect (OSTI)

    Stephen P. Mezyk; Bruce J. Mincher; Christian Ekberg; Gunnar Skarnemark

    2013-05-01

    The separation of the minor actinides from dissolved nuclear fuel remains a major challenge in developing large-scale waste separations processes. One important criterion is that all these processes must be robust under high acidity and radiation dose conditions. Here we have investigated the TRUEX ligand CMPO in dodecane, comparing the effects of gamma (60Co) with alpha irradiation using isotopic alpha sources (244Cm, 211At) experiments. The radiolytically-based CMPO decomposition efficiencies are approximately the same for both types of radiolysis, with the overall decomposition being significantly less when this formulation is irradiated in contact with aqueous acid.

  20. C%2B%2B tensor toolbox user manual.

    SciTech Connect (OSTI)

    Plantenga, Todd D.; Kolda, Tamara Gibson

    2012-04-01

    The C++ Tensor Toolbox is a software package for computing tensor decompositions. It is based on the Matlab Tensor Toolbox, and is particularly optimized for sparse data sets. This user manual briefly overviews tensor decomposition mathematics, software capabilities, and installation of the package. Tensors (also known as multidimensional arrays or N-way arrays) are used in a variety of applications ranging from chemometrics to network analysis. The Tensor Toolbox provides classes for manipulating dense, sparse, and structured tensors in C++. The Toolbox compiles into libraries and is intended for use with custom applications written by users.

  1. Antifoam degradation testing

    SciTech Connect (OSTI)

    Lambert, D. P.; Zamecnik, J. R.; Newell, D. D.; Williams, M. S.

    2015-08-20

    This report describes the results of testing to quantify the degradation products resulting from the dilution and storage of Antifoam 747. Antifoam degradation is of concern to the Defense Waste Processing Facility (DWPF) due to flammable decomposition products in the vapor phase of the Chemical Process Cell vessels, as well as the collection of flammable and organic species in the offgas condensate. The discovery that hexamethyldisiloxane is formed from the antifoam decomposition was the basis for a Potential Inadequacy in the Safety Analysis declaration by the DWPF.

  2. The FBI wavelet/scalar quantization standard for gray-scale fingerprint image compression

    SciTech Connect (OSTI)

    Bradley, J.N.; Brislawn, C.M. ); Hopper, T. )

    1993-01-01

    The FBI has recently adopted a standard for the compression of digitized 8-bit gray-scale fingerprint images. The standard is based on scalar quantization of a 64-subband discrete wavelet transform decomposition of the images, followed by Huffman coding. Novel features of the algorithm include the use of symmetric boundary conditions for transforming finite-length signals and a subband decomposition tailored for fingerprint images scanned at 500 dpi. The standard is intended for use in conjunction with ANSI/NBS-CLS 1-1993, American National Standard Data Format for the Interchange of Fingerprint Information, and the FBI's Integrated Automated Fingerprint Identification System.

  3. The FBI wavelet/scalar quantization standard for gray-scale fingerprint image compression

    SciTech Connect (OSTI)

    Bradley, J.N.; Brislawn, C.M.; Hopper, T.

    1993-05-01

    The FBI has recently adopted a standard for the compression of digitized 8-bit gray-scale fingerprint images. The standard is based on scalar quantization of a 64-subband discrete wavelet transform decomposition of the images, followed by Huffman coding. Novel features of the algorithm include the use of symmetric boundary conditions for transforming finite-length signals and a subband decomposition tailored for fingerprint images scanned at 500 dpi. The standard is intended for use in conjunction with ANSI/NBS-CLS 1-1993, American National Standard Data Format for the Interchange of Fingerprint Information, and the FBI`s Integrated Automated Fingerprint Identification System.

  4. Dispersion toughened ceramic composites and method for making same

    DOE Patents [OSTI]

    Stinton, David P. (Knoxville, TN); Lackey, Walter J. (Oak Ridge, TN); Lauf, Robert J. (Oak Ridge, TN)

    1986-01-01

    Ceramic composites exhibiting increased fracture toughness are produced by the simultaneous codeposition of silicon carbide and titanium disilicide by chemical vapor deposition. A mixture of hydrogen, methyltrichlorosilane and titanium tetrachloride is introduced into a furnace containing a substrate such as graphite or silicon carbide. The thermal decomposition of the methyltrichlorosilane provides a silicon carbide matrix phase and the decomposition of the titanium tetrachloride provides a uniformly dispersed second phase of the intermetallic titanium disilicide within the matrix phase. The fracture toughness of the ceramic composite is in the range of about 6.5 to 7.0 MPa.sqroot.m which represents a significant increase over that of silicon carbide.

  5. Dispersion toughened ceramic composites and method for making same

    DOE Patents [OSTI]

    Stinton, D.P.; Lackey, W.J.; Lauf, R.J.

    1984-09-28

    Ceramic composites exhibiting increased fracture toughness are produced by the simultaneous codeposition of silicon carbide and titanium disilicide by chemical vapor deposition. A mixture of hydrogen, methyltrichlorosilane and titanium tetrachloride is introduced into a furnace containing a substrate such as graphite or silicon carbide. The thermal decomposition of the methyltrichlorosilane provides a silicon carbide matrix phase and the decomposition of the titanium tetrachloride provides a uniformly dispersed second phase of the intermetallic titanium disilicide within the matrix phase. The fracture toughness of the ceramic composite is in the range of about 6.5 to 7.0 MPa..sqrt..m which represents a significant increase over that of silicon carbide.

  6. Parallel Computation of Persistent Homology using the Blowup Complex

    SciTech Connect (OSTI)

    Lewis, Ryan; Morozov, Dmitriy

    2015-04-27

    We describe a parallel algorithm that computes persistent homology, an algebraic descriptor of a filtered topological space. Our algorithm is distinguished by operating on a spatial decomposition of the domain, as opposed to a decomposition with respect to the filtration. We rely on a classical construction, called the Mayer--Vietoris blowup complex, to glue global topological information about a space from its disjoint subsets. We introduce an efficient algorithm to perform this gluing operation, which may be of independent interest, and describe how to process the domain hierarchically. We report on a set of experiments that help assess the strengths and identify the limitations of our method.

  7. Matrix Methods for Estimating the Coherence Functions from Estimates of the Cross-Spectral Density Matrix

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

    Smallwood, D. O.

    1996-01-01

    It is shown that the usual method for estimating the coherence functions (ordinary, partial, and multiple) for a general multiple-input! multiple-output problem can be expressed as a modified form of Cholesky decomposition of the cross-spectral density matrix of the input and output records. The results can be equivalently obtained using singular value decomposition (SVD) of the cross-spectral density matrix. Using SVD suggests a new form of fractional coherence. The formulation as a SVD problem also suggests a way to order the inputs when a natural physical order of the inputs is absent.

  8. Light-weight analyzer for odor recognition

    DOE Patents [OSTI]

    Vass, Arpad A; Wise, Marcus B

    2014-05-20

    The invention provides a light weight analyzer, e.g., detector, capable of locating clandestine graves. The detector utilizes the very specific and unique chemicals identified in the database of human decompositional odor. This detector, based on specific chemical compounds found relevant to human decomposition, is the next step forward in clandestine grave detection and will take the guess-work out of current methods using canines and ground-penetrating radar, which have historically been unreliable. The detector is self contained, portable and built for field use. Both visual and auditory cues are provided to the operator.

  9. nem_spread Ver. 5.10

    Energy Science and Technology Software Center (OSTI)

    2009-06-08

    Nem_spread reads it's input command file (default name nem_spread.inp), takes the named ExodusII geometry definition and spreads out the geometry (and optionally results) contained in that file out to a parallel disk system. The decomposition is taken from a scalar Nemesis load balance file generated by the companion utility nem_slice.

  10. Method and apparatus for pyrolysis of atactic polypropylene

    DOE Patents [OSTI]

    Staffin, H. Kenneth (New Brunswick, NJ); Roaper, R. B. (Martinsville, NJ)

    1986-09-23

    This invention relates to an apparatus and a method for pyrolytic decomposition of polymeric materials into lower molecular weight products involving the heat treatment of raw polymeric material within reactive conduits submerged in a fluidized bed furnace operated at pyrolizing temperatures.

  11. Competitive ion kinetics in direct mass spectrometric organic speciation: (Progress report, FY87-89)

    SciTech Connect (OSTI)

    Sieck, L.W.

    1987-01-01

    The following were studied: Stabilities of S...H/sup +/...X bonds, thermal decomposition of ions, stabilities of nitro anion association ions, stabilities of SF/sub 6//sup -/ association ions, proton affinities and cationic stabilization of tetraalkylhydrazines, adduct ion diagnostics in MS/MS, and anionic association ions incorporating RO/sup -/ or RCO/sub 2//sup -/.

  12. The behavior of matter under nonequilibrium conditions: Fundamental aspects and applications. Final report, April 15, 1991--July 14, 1994

    SciTech Connect (OSTI)

    NONE

    1994-12-31

    The authors have introduced an extended formulation of dynamics which allows a clear distinction between temporal behavior of stable systems on one hand, chaotic and unstable systems on the other. For stable systems, the evolution is deterministic and time reversible. For chaotic and unstable systems it is probabilistic and breaks time-symmetry. The new formulation of dynamics incorporates the second law of thermodynamics and leads therefore to a great unification of physics. More precisely: (1) the authors found that unstable dynamical systems have new spectral decompositions in extended functional spaces. These spectral decompositions incorporate new characteristics of the time evolution associated with irreversibility; (2) these new spectral decompositions can be in general obtained iteratively through a well-defined algorithm; and (3) the method provides spectral decompositions of the time evolutions operator in the Liouville space of density matrices or distribution functions which cannot be implemented in the Hilbert space (wave functions) or by trajectories. In summary, they obtain an extension of classical and quantum mechanics. This extension leads to the inclusion of irreversibility into the framework of dynamics. Moreover, it also provides the theoretical basis for probabilistic predictions and control methods for complex systems, where the conventional deterministic predictions and control methods do not work.

  13. Degradation chemistry of PETN and its homologues

    SciTech Connect (OSTI)

    Shepodd, T.; Behrens, R.; Anex, D.; Miller, D.; Anderson, K.

    1997-11-01

    Pentaerythritol tetranitrate (PETN) is used throughout the stockpile as an energetic material. The formulation of PETN into XTX8003 (80% PETN, 20% Sylgard 182) creates an extrudable energetic composite. PETN and XTX8003 are used in the firesets for the retired W68 (MC2370) and the W76 (MC3028). When faced with potential lifetime extensions, energetic materials are naturally suspect regarding their output after prolonged aging. The authors have studied PETN and XTX8003 by looking at 25-year-old samples from retired MC2370s and newer materials. Both the old and new materials have also been placed in various accelerated aging protocols to investigate any decomposition that might occur over time. PETN is known to decompose autocatalytically even in the early stages of decomposition, but the process is poorly understood. Published values for the activation energy of decomposition vary by >40 kcal/mol. The 12 million year half life predicted for room temperature PETN would be dramatically shortened by chemical influences that lead to lower energy decomposition pathways. Degree of confinement, purity, and crystal size all influence degradation rates. In this paper, the authors observe the effects of chemical and thermal aging on PETN. They anticipate changes in mechanism at higher temperature aging, and before trying to extrapolate to lower temperatures, they want to make sure that they understand the different chemical processed involved.

  14. Surface texture and specific adsorption sites of sol-gel synthesized anatase TiO{sub 2} nanoparticles

    SciTech Connect (OSTI)

    Zaki, Mohamed I.; Mekhemer, Gamal A.H.; Fouad, Nasr E.; Jagadale, Tushar C.; Ogale, Satishchandra B.

    2010-10-15

    The surface properties of sol-gel synthesized anatase titania (TiO{sub 2}) nanoparticles are probed by sorptiometry, infrared absorption spectroscopy, UV-vis diffuse reflectance spectroscopy and high resolution transmission electron microscopy. The results reveal strong correlations of the surface area, porosity, pyridine adsorption capacity and strength, and catalytic methylbutynol decomposition activity.

  15. Hydrogen-permeable composite metal membrane and uses thereof

    DOE Patents [OSTI]

    Edlund, D.J.; Friesen, D.T.

    1993-06-08

    Various hydrogen production and hydrogen sulfide decomposition processes are disclosed that utilize composite metal membranes that contain an intermetallic diffusion barrier separating a hydrogen-permeable base metal and a hydrogen-permeable coating metal. The barrier is a thermally stable inorganic proton conductor.

  16. Method of depositing wide bandgap amorphous semiconductor materials

    DOE Patents [OSTI]

    Ellis, Jr., Frank B. (Princeton Junction, NJ); Delahoy, Alan E. (Rocky Hill, NJ)

    1987-09-29

    A method of depositing wide bandgap p type amorphous semiconductor materials on a substrate without photosensitization by the decomposition of one or more higher order gaseous silanes in the presence of a p-type catalytic dopant at a temperature of about 200.degree. C. and a pressure in the range from about 1-50 Torr.

  17. Method of deposition of silicon carbide layers on substrates and product

    DOE Patents [OSTI]

    Angelini, Peter; DeVore, Charles E.; Lackey, Walter J.; Blanco, Raymond E.; Stinton, David P.

    1984-01-01

    A method for direct chemical vapor deposition of silicon carbide to substrates, especially nuclear waste particles, is provided by the thermal decomposition of methylsilane at about 800.degree. C. to 1050.degree. C. when the substrates have been confined within a suitable coating environment.

  18. Method and apparatus for pyrolysis of atactic polypropylene

    DOE Patents [OSTI]

    Staffin, H.K.; Roaper, R.B.

    1986-09-23

    This invention relates to an apparatus and a method for pyrolytic decomposition of polymeric materials into lower molecular weight products involving the heat treatment of raw polymeric material within reactive conduits submerged in a fluidized bed furnace operated at pyrolyzing temperatures. 1 fig.

  19. Silicone oil contamination and electrical contact resistance degradation of low-force gold contacts.

    SciTech Connect (OSTI)

    Dugger, Michael Thomas; Dickrell, Daniel John, III

    2006-02-01

    Hot-switched low-force gold electrical contact testing was performed using a nanomechanical test apparatus to ascertain the sensitivity of simulated microelectromechanical systems (MEMS) contact to silicone oil contamination. The observed cyclic contact resistance degradation was dependent on both closure rate and noncontact applied voltage. The decomposition of silicone oil from electrical arcing was hypothesized as the degradation mechanism.

  20. Chemical kinetics and oil shale process design

    SciTech Connect (OSTI)

    Burnham, A.K.

    1993-07-01

    Oil shale processes are reviewed with the goal of showing how chemical kinetics influences the design and operation of different processes for different types of oil shale. Reaction kinetics are presented for organic pyrolysis, carbon combustion, carbonate decomposition, and sulfur and nitrogen reactions.

  1. Accelerating Computation of the Unit Commitment Problem (Presentation)

    SciTech Connect (OSTI)

    Hummon, M.; Barrows, C.; Jones, W.

    2013-10-01

    Production cost models (PCMs) simulate power system operation at hourly (or higher) resolution. While computation times often extend into multiple days, the sequential nature of PCM's makes parallelism difficult. We exploit the persistence of unit commitment decisions to select partition boundaries for simulation horizon decomposition and parallel computation. Partitioned simulations are benchmarked against sequential solutions for optimality and computation time.

  2. pCamal

    Energy Science and Technology Software Center (OSTI)

    2009-06-29

    The Parallel CUBIT Adaptive Mesh Algorithm Library (pCAMAL) is a distributed-memory embarrassingly parallel hexahedral mesh generator. pCAMAL utilizes the sweeping method following a serial step of geometry decomposition conducted in the CUBIT geometry preparation and mesh generation tool. pCAMAL also reports mesh quality statistics as calculated in parallel from per-element quality metrics.

  3. The biomethanation of waste material; An example in Germany

    SciTech Connect (OSTI)

    Shin, K.C. )

    1991-01-01

    This paper reports that digester gas (biogas) can be generated from anaerobic decomposition of organic waste substances. In the municipal sewage treatment plants in Germany most of the gas production is used for heating and electric power generation. The major portion of solid waste shall be returned to the economical circuit as biogas, compost and recyclable materials.

  4. TiO2 nanotube arrays grown in ionic liquids: high-efficiency in photocatalysis and pore-widening

    SciTech Connect (OSTI)

    Li, Huaqing; Qu, Jun; Cui, Qingzhou; Xu, Hanbing; Luo, Huimin; Chi, Miaofang; Meisner, Roberta Ann; Wang, Wei; Dai, Sheng

    2011-01-01

    Debris-free, long, well-separated TiO2 nanotube arrays were obtained using an ionic liquid (IL) as electrolyte. The high conductivity of IL resulted in fast pore widening and few contaminants from electrolyte decomposition leading to high photocatalytic efficiency in water splitting.

  5. Method of deposition of silicon carbide layers on substrates

    DOE Patents [OSTI]

    Angelini, P.; DeVore, C.E.; Lackey, W.J.; Blanco, R.E.; Stinton, D.P.

    1982-03-19

    A method for direct chemical vapor deposition of silicon carbide to substrates, especially nuclear waste particles, is provided by the thermal decomposition of methylsilane at 800 to 1050/sup 0/C when the substrates have been confined within a suitable coating environment.

  6. Thermal stability of bimetallic Au/Fe nanoparticles in silica matrix

    SciTech Connect (OSTI)

    Pannu, Compesh Singh, Udai B. Hooda, Sonu Kabiraj, D. Avasthi, D. K.

    2014-04-24

    Thin silica film containing Au and Fe bimetallic nanoparticles were prepared by atom beam cosputtering. The samples were annealed at different temperatures from 400 to 800 C to study the thermal stability of bimetallic nanoparticles using X ray diffraction. It is observed that at 800 C strong structural rearrangement took place leading to thermal decomposition of bimetallic nanoparticles.

  7. Hydrogen Storage Properties of New Hydrogen-Rich BH3NH3-Metal Hydride (TiH2, ZrH2, MgH2, and/or CaH2) Composite Systems

    SciTech Connect (OSTI)

    Choi, Young Joon; Xu, Yimin; Shaw, Wendy J.; Ronnebro, Ewa

    2012-04-19

    Ammonia borane (AB = NH3BH3) is one of the most attractive materials for chemical hydrogen storage due to its high hydrogen contents of 19.6 wt.%, however, impurity levels of borazine, ammonia and diborane in conjunction with foaming and exothermic hydrogen release calls for finding ways to mitigate the decomposition reactions. In this paper we present a solution by mixing AB with metal hydrides (TiH2, ZrH2, MgH2 and CaH2) which have endothermic hydrogen release in order to control the heat release and impurity levels from AB upon decomposition. The composite materials were prepared by mechanical ball milling, and their H2 release properties were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The formation of volatile products from decomposition side reactions, such as borazine (N3B3H6) was determined by mass spectrometry (MS). Sieverts type pressure-composition-temperature (PCT) gas-solid reaction instrument was adopted to observe the kinetics of the H2 release reactions of the combined systems and neat AB. In situ 11B MAS-NMR revealed a destabilized decomposition pathway. We found that by adding specific metal hydrides to AB we can eliminate the impurities and mitigate the heat release.

  8. Method for the preparation of ferrous low carbon porous material

    SciTech Connect (OSTI)

    Miller, Curtis Jack

    2014-05-27

    A method for preparing a porous metal article using a powder metallurgy forming process is provided which eliminates the conventional steps associated with removing residual carbon. The method uses a feedstock that includes a ferrous metal powder and a polycarbonate binder. The polycarbonate binder can be removed by thermal decomposition after the metal article is formed without leaving a carbon residue.

  9. CuInSe/sub 2/-based photoelectrochemical cells: their use in characterization of thin CuInSe/sub 2/ films, and as photovoltaic cells per se

    SciTech Connect (OSTI)

    Cahen, D.; Chen, Y.W.; Ireland, P.J.; Noufi, R.; Turner, J.A.; Rincon, C.; Bachmann, K.J.

    1984-05-01

    Photoelectrochemistry has been employed to characterize the p-CuInSe/sub 2/ component of the CdS/CuInSe/sub 2/ on-metal and a nonaqueous electrolyte containing a redox couple not specifically adsorbed onto the semiconductor, we can test the films for photovoltaic activity and obtain effective electronic properties of them, before CdS deposition, in a nondestructive manner. Electrochemical decomposition of CuInSe/sub 2/ was investigated in acetonitrile solutions to determine the mechanism of decomposition (n and p) in the dark and under illumination. Electrochemical, solution chemical and surface analyses confirmed at the light-assisted decomposition of CuInSe/sub 2/ resulted in metal ions and elemental chalcogen. On the basis of the results from the electrochemical decomposition, and studies on the solid state chemistry of the (Cu/sub 2/Se)/sub x/(In/sub 2/Se/sub 3/)/sub 1-x/ system and surface analyses, the CuInSe/sub 2//polyiodide interface was stabilized and up to 11.7% conversion efficiencies were obtained.

  10. Evaluation of global horizontal irradiance to plane-of-array irradiance models at locations across the United States

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

    Lave, Matthew; Hayes, William; Pohl, Andrew; Hansen, Clifford W.

    2015-02-02

    We report an evaluation of the accuracy of combinations of models that estimate plane-of-array (POA) irradiance from measured global horizontal irradiance (GHI). This estimation involves two steps: 1) decomposition of GHI into direct and diffuse horizontal components and 2) transposition of direct and diffuse horizontal irradiance (DHI) to POA irradiance. Measured GHI and coincident measured POA irradiance from a variety of climates within the United States were used to evaluate combinations of decomposition and transposition models. A few locations also had DHI measurements, allowing for decoupled analysis of either the decomposition or the transposition models alone. Results suggest that decompositionmore » models had mean bias differences (modeled versus measured) that vary with climate. Transposition model mean bias differences depended more on the model than the location. Lastly, when only GHI measurements were available and combinations of decomposition and transposition models were considered, the smallest mean bias differences were typically found for combinations which included the Hay/Davies transposition model.« less

  11. Analysis of thermally-degrading, confined HMX

    SciTech Connect (OSTI)

    Hobbs, M.L.; Schmitt, R.G.; Renlund, A.M.

    1996-12-01

    The response of a thermally-degrading, confined HMX pellet is analyzed using a Reactive Elastic-Plastic (REP) constitutive model which is founded on the collapse and growth of internal inclusions resulting from physical and chemical processes such as forced displacement, thermal expansion, and/or decomposition. Axial stress predictions compare adequately to data. Deficiencies in the model and future directions are discussed.

  12. Exact mapping from singular value spectrum of a class of fractal images to entanglement spectrum of one-dimensional free fermions

    SciTech Connect (OSTI)

    Matsueda, Hiroaki; Lee, Ching Hua

    2015-03-10

    We examine singular value spectrum of a class of two-dimensional fractal images. We find that the spectra can be mapped onto entanglement spectra of free fermions in one dimension. This exact mapping tells us that the singular value decomposition is a way of detecting a holographic relation between classical and quantum systems.

  13. Thermal stability and oxygen-loss characteristics of Pt(O) films prepared by reactive sputtering

    SciTech Connect (OSTI)

    Saenger, K.L.; Cabral, C. Jr.; Lavoie, C.; Rossnagel, S.M.

    1999-12-01

    Pt(O) films having compositions ranging from pure Pt to amorphous platinum oxide a-PtO{sub x} (x{approximately}1.4) were prepared by reactive sputtering and examined during and after heating to temperatures used for deposition and processing of high-epsilon (HE) and ferroelectric (FE) materials (400{endash}650&hthinsp;{degree}C). A two stage decomposition process was observed for a-PtO{sub x} (x{approximately}1.4) films heated in N{sub 2}, with the first stage of decomposition beginning at temperatures well below 400&hthinsp;{degree}C. In an O{sub 2} ambient, decomposition was accompanied by formation of a crystalline Pt{sub 3}O{sub 4} phase prior to complete decomposition to metallic Pt. However, the relatively slow rate of oxygen loss from a-PtO{sub x} suggests that significant amounts of oxygen should remain in Pt(O) electrodes after HE/FE layer deposition. {copyright} {ital 1999 American Institute of Physics.}

  14. No reduction using sublimation of cyanuric acid

    DOE Patents [OSTI]

    Perry, Robert A.

    1990-01-01

    An arrangement for reducing the NO content of a gas stream comprises contacting the gas stream with NHCO into a temperature effective for heat induced decomposition of HNCO and for resultant lowering of the NO content of the gas stream. Preferably, the HNCO is generated by sublimation of cyanuric acid.

  15. System for NO reduction using sublimation of cyanuric acid

    DOE Patents [OSTI]

    Perry, Robert A.

    1989-01-01

    An arrangement for reducing the NO content of a gas stream comprises contacting the gas stream with HNCO at a temperature effective for heat induced decomposition of HNCO and for resultant lowering of the NO content of the gas stream. Preferably, the HNCO is generated by sublimation of cyanuric acid.

  16. System for NO reduction using sublimation of cyanuric acid

    DOE Patents [OSTI]

    Perry, R.A.

    1989-01-24

    An arrangement for reducing the NO content of a gas stream comprises contacting the gas stream with HNCO at a temperature effective for heat induced decomposition of HNCO and for resultant lowering of the NO content of the gas stream. Preferably, the HNCO is generated by sublimation of cyanuric acid. 1 fig.

  17. NO reduction using sublimation of cyanuric acid

    DOE Patents [OSTI]

    Perry, Robert A.

    1988-01-01

    An arrangement for reducing the NO content of a gas stream comprises contacting the gas stream with HNCO at a temperature effective for heat induced decomposition of HNCO and for resultant lowering of the NO content of the gas stream. Preferably, the HNCO is generated by sublimation of cyanuric acid.

  18. ENHANCED CHEMICAL CLEANING: EFFECTIVENESS OF THE UV LAMP TO DECOMPOSE OXALATES

    SciTech Connect (OSTI)

    Ketusky, E.; Huff, T.; Sudduth, C.

    2010-01-19

    Enhanced Chemical Cleaning is a new process scheduled to begin cleaning Savannah River Site High Level Waste Tanks in 2012. It is an improvement over the current chemical cleaning method, in that it minimizes downstream impacts on the High Level Waste System. It is based on a state of the art scale removal process used on the secondary side of nuclear power plants, with modifications to accommodate the unique constraints created by the tanks. Both Enhanced Chemical Cleaning and the scale removal process are founded on dissolving metal oxides/hydroxides using oxalic acid, with subsequent oxalate decomposition via hydroxylation using ozone or peroxide, and UV light as a catalyst. A divergence Enhanced Chemical Cleaning has from nuclear power scale removal is the significantly increased solids concentration during oxalate decomposition. These solids can limit the ability of the UV light to create hydroxyl radicals, either by limiting the ability of the light to penetrate through the solution, or by increasing the fouling rate on the UV light. Both will decrease the overall catalytic effectiveness, thereby decreasing the concentration of formed hydroxyl radicals. The hydroxyl radicals are the driving force behind the oxalate decomposition. To understand the impact of increased solids, testing was performed using a medium pressure UV light inside an ozone supplied Oxalate Decomposition Reactor. Using a dissolved metal sludge simulant with an initial oxalate concentration greater than 12,000 ppm, and an initial pH of about 2.0, the spent acid solution was recirculated through the reactor, while the UV light was allowed to foul. For the first few hours, the oxalate decomposition rate was about 1,300 ppm/hour. After about 3 hours, enough time for the UV lamp to foul, the oxalate decomposition rate decreased to about 500 ppm/hour. The decomposition rate then remained roughly constant for the next 16 hours. Overall, testing showed that the oxalate destruction rate decreased by about 2.8. Results from very similartests with similar chemistry suggest that the impact should be about 10. Based on the limited reaction pathwayfor the creation of hydroxyl radicals with iron, ozone, and no UV, the discrepancy suggests that initially, at 'time zero' the UV light failed to perform up to expectations. It is therefore concluded that regardless of the fouling rate, either the increased solids concentration is impacting the initial penetrability (i.e. to many solids), or the light is not adequately sized/configured to have the appropriate flux.

  19. GIS-and Web-based Water Resource Geospatial Infrastructure for Oil Shale Development

    SciTech Connect (OSTI)

    Zhou, Wei; Minnick, Matthew; Geza, Mengistu; Murray, Kyle; Mattson, Earl

    2012-09-30

    The Colorado School of Mines (CSM) was awarded a grant by the National Energy Technology Laboratory (NETL), Department of Energy (DOE) to conduct a research project en- titled GIS- and Web-based Water Resource Geospatial Infrastructure for Oil Shale Development in October of 2008. The ultimate goal of this research project is to develop a water resource geo-spatial infrastructure that serves as baseline data for creating solutions on water resource management and for supporting decisions making on oil shale resource development. The project came to the end on September 30, 2012. This final project report will report the key findings from the project activity, major accomplishments, and expected impacts of the research. At meantime, the gamma version (also known as Version 4.0) of the geodatabase as well as other various deliverables stored on digital storage media will be send to the program manager at NETL, DOE via express mail. The key findings from the project activity include the quantitative spatial and temporal distribution of the water resource throughout the Piceance Basin, water consumption with respect to oil shale production, and data gaps identified. Major accomplishments of this project include the creation of a relational geodatabase, automated data processing scripts (Matlab) for database link with surface water and geological model, ArcGIS Model for hydrogeologic data processing for groundwater model input, a 3D geological model, surface water/groundwater models, energy resource development systems model, as well as a web-based geo-spatial infrastructure for data exploration, visualization and dissemination. This research will have broad impacts of the devel- opment of the oil shale resources in the US. The geodatabase provides a baseline data for fur- ther study of the oil shale development and identification of further data collection needs. The 3D geological model provides better understanding through data interpolation and visualization techniques of the Piceance Basin structure spatial distribution of the oil shale resources. The sur- face water/groundwater models quantify the water shortage and better understanding the spatial distribution of the available water resources. The energy resource development systems model reveals the phase shift of water usage and the oil shale production, which will facilitate better planning for oil shale development. Detailed descriptions about the key findings from the project activity, major accomplishments, and expected impacts of the research will be given in the sec- tion of ACCOMPLISHMENTS, RESULTS, AND DISCUSSION of this report.

  20. SELECTIVE NOx RECIRCULATION FOR STATIONARY LEAN-BURN NATURAL GAS ENGINES

    SciTech Connect (OSTI)

    Nigel Clark; Gregory Thompson; Richard Atkinson; Chamila Tissera; Matt Swartz; Emre Tatli; Ramprabhu Vellaisamy

    2005-01-01

    The research program conducted at the West Virginia University Engine and Emissions Research Laboratory (EERL) is working towards the verification and optimization of an approach to remove nitric oxides from the exhaust gas of lean burn natural gas engines. This project was sponsored by the US Department of Energy, National Energy Technology Laboratory (NETL) under contract number: DE-FC26-02NT41608. Selective NOx Recirculation (SNR) involves three main steps. First, NOx is adsorbed from the exhaust stream, followed by periodic desorption from the aftertreatment medium. Finally the desorbed NOx is passed back into the intake air stream and fed into the engine, where a percentage of the NOx is decomposed. This reporting period focuses on the NOx decomposition capability in the combustion process. Although researchers have demonstrated NOx reduction with SNR in other contexts, the proposed program is needed to further understand the process as it applies to lean burn natural gas engines. SNR is in support of the Department of Energy goal of enabling future use of environmentally acceptable reciprocating natural gas engines through NOx reduction under 0.1 g/bhp-hr. The study of decomposition of oxides of nitrogen (NOx) during combustion in the cylinder was conducted on a 1993 Cummins L10G 240 hp lean burn natural gas engine. The engine was operated at different air/fuel ratios, and at a speed of 800 rpm to mimic a larger bore engine. A full scale dilution tunnel and analyzers capable of measuring NOx, CO{sub 2}, CO, HC concentrations were used to characterize the exhaust gas. Commercially available nitric oxide (NO) was used to mimic the NOx stream from the desorption process through a mass flow controller and an injection nozzle. The same quantity of NOx was injected into the intake and exhaust line of the engine for 20 seconds at various steady state engine operating points. NOx decomposition rates were obtained by averaging the peak values at each set point minus the baseline and finding the ratio between the injected NO amounts. It was observed that the air/fuel ratio, injected NO quantity and engine operating points affected the NOx decomposition rates of the natural gas engine. A highest NOx decomposition rate of 27% was measured from this engine. A separate exploratory tests conducted with a gasoline engine with a low air/fuel ratio yielded results that suggested, that high NOx decomposition rates may be possible if a normally lean burn engine were operated at conditions closer to stoichiometric, with high exhaust gas recirculation (EGR) for a brief period of time during the NOx decomposition phase and with a wider range of air/fuel ratios. Chemical kinetic model predictions using CHEMKIN were performed to relate the experimental data with the established rate and equilibrium models. NOx decomposition rates from 35% to 42% were estimated using the CHEMKIN software. This provided insight on how to maximize NOx decomposition rates for a large bore engine. In the future, the modeling will be used to examine the effect of higher NO{sub 2}/NO ratios that are associated with lower speed and larger bore lean burn operation.

  1. The Impact of Aluminum and Iron Substitution on the Structure and Electrochemistry of Li[Ni0.4Co0.2-yMyMn0.4]O2 Materials

    SciTech Connect (OSTI)

    WIlcox, James D.; Rodriguez, Efrain E.; Doeff, Marca M.

    2009-07-23

    Li[Ni0.4Co0.2-yMyMn0.4]O2 (0<_y<_0.2) (M=Al) and Li[Ni0.4Co0.15Fe0.05Mn0.4]O2 compounds were prepared in order to investigate the effect of replacement of all or part of the cobalt on the structural and electrochemical properties. The impact of substitution on the structure has been examined by both x-ray and neutron diffraction experiments. The incorporation of aluminum has minimal effect on the anti-site defect concentration, but leads to structural changes that affect electrochemical performance. The most important effect is an opening of the lithium slab dimension upon substitution, which results in improved rate performance compared to the parent compound. In contrast, the lithium slab dimension is not affected by iron substitution and no rate enhancement effect is observed. The cycling stability of aluminum containing materials is superior to both the parent material and iron-substituted materials.

  2. Cybersim: geographic, temporal, and organizational dynamics of malware propagation

    SciTech Connect (OSTI)

    Santhi, Nandakishore; Yan, Guanhua; Eidenbenz, Stephan

    2010-01-01

    Cyber-infractions into a nation's strategic security envelope pose a constant and daunting challenge. We present the modular CyberSim tool which has been developed in response to the need to realistically simulate at a national level, software vulnerabilities and resulting mal ware propagation in online social networks. CyberSim suite (a) can generate realistic scale-free networks from a database of geocoordinated computers to closely model social networks arising from personal and business email contacts and online communities; (b) maintains for each,bost a list of installed software, along with the latest published vulnerabilities; (d) allows designated initial nodes where malware gets introduced; (e) simulates, using distributed discrete event-driven technology, the spread of malware exploiting a specific vulnerability, with packet delay and user online behavior models; (f) provides a graphical visualization of spread of infection, its severity, businesses affected etc to the analyst. We present sample simulations on a national level network with millions of computers.

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

    SciTech Connect (OSTI)

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

    2015-06-01

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

  4. Modeling Improvements for Air Source Heat Pumps using Different Expansion Devices at Varied Charge Levels Part II

    SciTech Connect (OSTI)

    Shen, Bo [ORNL

    2011-01-01

    This paper describes steady-state performance simulations performed on a 3-ton R-22 split heat pump in heating mode. In total, 150 steady-state points were simulated, which covers refrigerant charge levels from 70 % to 130% relative to the nominal value, the outdoor temperatures at 17 F (-8.3 C), 35 F (1.7 C) and 47 F (8.3 C), indoor air flow rates from 60% to 150% of the rated air flow rate, and two types of expansion devices (fixed orifice and thermostatic expansion valve). A charge tuning method, which is to calibrate the charge inventory model based on measurements at two operation conditions, was applied and shown to improve the system simulation accuracy significantly in an extensive range of charge levels. In addition, we discuss the effects of suction line accumulator in modeling a heat pump system using either a fixed orifice or thermal expansion valve. Last, we identify the issue of refrigerant mass flow mal-distribution at low charge levels and propose an improved modeling approach.

  5. MCrAlY bond coat with enhanced Yttrium layer

    DOE Patents [OSTI]

    Jablonski, Paul D; Hawk, Jeffrey A

    2015-04-21

    One or more embodiments relates to an MCrAlY bond coat comprising an MCrAlY layer in contact with a Y--Al.sub.2O.sub.3 layer. The MCrAlY layer is comprised of a .gamma.-M solid solution, a .beta.-MAl intermetallic phase, and Y-type intermetallics. The Y--Al.sub.2O.sub.3 layer is comprised of Yttrium atoms coordinated with oxygen atoms comprising the Al.sub.2O.sub.3 lattice. Both the MCrAlY layer and the Y--Al.sub.2O.sub.3 layer have a substantial absence of Y--Al oxides, providing advantage in the maintainability of the Yttrium reservoir within the MCrAlY bulk. The MCrAlY bond coat may be fabricated through application of a Y.sub.2O.sub.3 paste to an MCrAlY material, followed by heating in a non-oxidizing environment.

  6. Structural, magnetic, and electronic properties of the Co-Fe-Al oxide spinel system: Density-functional theory calculations

    SciTech Connect (OSTI)

    Walsh, Aron; Wei, S.-H.; Yan Yanfa; Al-Jassim, M. M.; Turner, John A.; Woodhouse, Michael; Parkinson, B. A.

    2007-10-15

    A systematic study of nine binary and ternary spinel oxides formed from Co, Al, and Fe is presented by means of density functional theory. Analysis of the structural, magnetic, and electronic properties through the series of materials is carried out. Preference for the octahedral spinel sites are found in the order FeMAl{sub 2}O{sub 4} as the octahedral M metal sites are lost. However, for stoichiometric FeAl{sub 2}O{sub 4}, the unsatisfied valence state of Fe results in partial occupation of the conduction band. The results and chemical trends are discussed in terms of atomic site and orbital energies, and in relation to potential photoelectrolysis activity for the splitting of water as a renewable means of hydrogen production.

  7. Three-dimensional carbon fibers and method and apparatus for their production

    DOE Patents [OSTI]

    Muradov, Nazim Z.

    2012-02-21

    This invention relates to novel three-dimensional (3D) carbon fibers which are original (or primary) carbon fibers (OCF) with secondary carbon filaments (SCF) grown thereon, and, if desired, tertiary carbon filaments (TCF) are grown from the surface of SCF forming a filamentous carbon network with high surface area. The methods and apparatus are provided for growing SCF on the OCF by thermal decomposition of carbonaceous gases (CG) over the hot surface of the OCF without use of metal-based catalysts. The thickness and length of SCF can be controlled by varying operational conditions of the process, e.g., the nature of CG, temperature, residence time, etc. The optional activation step enables one to produce 3D activated carbon fibers with high surface area. The method and apparatus are provided for growing TCF on the SCF by thermal decomposition of carbonaceous gases over the hot surface of the SCF using metal catalyst particles.

  8. Method for the protection of extreme ultraviolet lithography optics

    DOE Patents [OSTI]

    Grunow, Philip A.; Clift, Wayne M.; Klebanoff, Leonard E.

    2010-06-22

    A coating for the protection of optical surfaces exposed to a high energy erosive plasma. A gas that can be decomposed by the high energy plasma, such as the xenon plasma used for extreme ultraviolet lithography (EUVL), is injected into the EUVL machine. The decomposition products coat the optical surfaces with a protective coating maintained at less than about 100 .ANG. thick by periodic injections of the gas. Gases that can be used include hydrocarbon gases, particularly methane, PH.sub.3 and H.sub.2S. The use of PH.sub.3 and H.sub.2S is particularly advantageous since films of the plasma-induced decomposition products S and P cannot grow to greater than 10 .ANG. thick in a vacuum atmosphere such as found in an EUVL machine.

  9. Spectroscopic studies of the 110{degree}C thermal aging of PETN

    SciTech Connect (OSTI)

    Dosser, L.R.; Seliskar, C.J.

    1992-07-30

    The 110{degrees}C thermal aging parameters, including initial rates of decomposition, of four types of pentaerythritol tetranitrate (PETN) over a period of ten months are presented. Both decomposition products nitric oxide, NO, and nitrogen dioxide, N0{sub 2} were monitored from multiple, hermetically-sealed, in vacuo samples. Nitric oxide appears to be the first nitrogen oxide product evolved. Nitrogen dioxide produced by abrupt thermal aging is more slowly converted to nitric oxide by a 1:1 process. The behavior of samples of RR5K PETN was significantly different from that of other powders studied. Further work is in progress to better define the thermal aging of RR5K PETN.

  10. Smooth local subspace projection for nonlinear noise reduction

    SciTech Connect (OSTI)

    Chelidze, David

    2014-03-15

    Many nonlinear or chaotic time series exhibit an innate broad spectrum, which makes noise reduction difficult. Local projective noise reduction is one of the most effective tools. It is based on proper orthogonal decomposition (POD) and works for both map-like and continuously sampled time series. However, POD only looks at geometrical or topological properties of data and does not take into account the temporal characteristics of time series. Here, we present a new smooth projective noise reduction method. It uses smooth orthogonal decomposition (SOD) of bundles of reconstructed short-time trajectory strands to identify smooth local subspaces. Restricting trajectories to these subspaces imposes temporal smoothness on the filtered time series. It is shown that SOD-based noise reduction significantly outperforms the POD-based method for continuously sampled noisy time series.

  11. Denitrification of combustion gases. [Patent application

    DOE Patents [OSTI]

    Yang, R.T.

    1980-10-09

    A method for treating waste combustion gas to remove the nitrogen oxygen gases therefrom is disclosed wherein the waste gas is first contacted with calcium oxide which absorbs and chemically reacts with the nitrogen oxide gases therein at a temperature from about 100/sup 0/ to 430/sup 0/C. The thus reacted calcium oxide (now calcium nitrate) is then heated at a temperature range between about 430/sup 0/ and 900/sup 0/C, resulting in regeneration of the calcium oxide and production of the decomposition gas composed of nitrogen and nitrogen oxide gas. The decomposition gases can be recycled to the calcium oxide contacting step to minimize the amount of nitrogen oxide gases in the final product gas.

  12. Signal processing method and system for noise removal and signal extraction

    DOE Patents [OSTI]

    Fu, Chi Yung (San Francisco, CA); Petrich, Loren (Lebanon, OR)

    2009-04-14

    A signal processing method and system combining smooth level wavelet pre-processing together with artificial neural networks all in the wavelet domain for signal denoising and extraction. Upon receiving a signal corrupted with noise, an n-level decomposition of the signal is performed using a discrete wavelet transform to produce a smooth component and a rough component for each decomposition level. The n.sup.th level smooth component is then inputted into a corresponding neural network pre-trained to filter out noise in that component by pattern recognition in the wavelet domain. Additional rough components, beginning at the highest level, may also be retained and inputted into corresponding neural networks pre-trained to filter out noise in those components also by pattern recognition in the wavelet domain. In any case, an inverse discrete wavelet transform is performed on the combined output from all the neural networks to recover a clean signal back in the time domain.

  13. Billion-atom synchronous parallel kinetic Monte Carlo simulations of critical 3D Ising systems

    SciTech Connect (OSTI)

    Martinez, E.; Monasterio, P.R.; Marian, J.

    2011-02-20

    An extension of the synchronous parallel kinetic Monte Carlo (spkMC) algorithm developed by Martinez et al. [J. Comp. Phys. 227 (2008) 3804] to discrete lattices is presented. The method solves the master equation synchronously by recourse to null events that keep all processors' time clocks current in a global sense. Boundary conflicts are resolved by adopting a chessboard decomposition into non-interacting sublattices. We find that the bias introduced by the spatial correlations attendant to the sublattice decomposition is within the standard deviation of serial calculations, which confirms the statistical validity of our algorithm. We have analyzed the parallel efficiency of spkMC and find that it scales consistently with problem size and sublattice partition. We apply the method to the calculation of scale-dependent critical exponents in billion-atom 3D Ising systems, with very good agreement with state-of-the-art multispin simulations.

  14. Methods and systems for producing syngas

    DOE Patents [OSTI]

    Hawkes, Grant L; O'Brien, James E; Stoots, Carl M; Herring, J. Stephen; McKellar, Michael G; Wood, Richard A; Carrington, Robert A; Boardman, Richard D

    2013-02-05

    Methods and systems are provided for producing syngas utilizing heat from thermochemical conversion of a carbonaceous fuel to support decomposition of at least one of water and carbon dioxide using one or more solid-oxide electrolysis cells. Simultaneous decomposition of carbon dioxide and water or steam by one or more solid-oxide electrolysis cells may be employed to produce hydrogen and carbon monoxide. A portion of oxygen produced from at least one of water and carbon dioxide using one or more solid-oxide electrolysis cells is fed at a controlled flow rate in a gasifier or combustor to oxidize the carbonaceous fuel to control the carbon dioxide to carbon monoxide ratio produced.

  15. Rapid formation of the Bi{sub 2{minus}x}Pb{sub x}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub y} high {Tc}-phase, using spray-dried nitrate precursor powders

    SciTech Connect (OSTI)

    Van Driessche, I.; Mouton, R.; Hoste, S.

    1996-08-01

    This study describes the use of spray-dried nitrate precursor powders in the synthesis of Bi-2223 high {Tc}-superconductors. The decomposition of the precursor powder is studied using TGA/DTA, XRD, IR, and nitrogen analyses. The particle size is determined using SEM. The low decomposition temperature of the nitrates ({approximately}600 C) and the small particle size of the spray dried powder ({approximately}3{center_dot}10{sup {minus}6} m), resulting in a lowering of the calcination temperature and a shortening of the sinter time, enabled the authors to synthesize a > 96% pure Bi-2223 phase (from XRD peak intensities) after a thermal process of 5h at 650 C and 60 h at 855 C.

  16. The effect of block copolymer on the phase behavior of a polymer blend

    SciTech Connect (OSTI)

    Sung, L.; Jackson, C.L.; Hess, D.

    1995-12-31

    The effect of an interfacial modifier on the phase behavior of a blend has been investigated using time-resolved fight scattering and small angle neutron scattering techniques. A low molecular weight binary blend of deuterated polystyrene/polybutadiene (PSD/PB) with PSD-PB diblock copolymer as the added interfacial modifier was studied. We observed that the critical temperature of the blend decreases with increasing copolymer content and the kinetics of the phase separation (via spinodal decomposition) slows down in the presence of the copolymer. The transition from early to late stage spinodal decomposition in a near critical mixture of the binary blend was analyzed and compared to available theories. In addition, transmission electron microscopy and optical microscopy studies were used to examine the morphology of the system under various temperature quench conditions.

  17. Silver manganese oxide electrodes for lithium batteries

    DOE Patents [OSTI]

    Thackeray, Michael M.; Vaughey, John T.; Dees, Dennis W.

    2006-05-09

    This invention relates to electrodes for non-aqueous lithium cells and batteries with silver manganese oxide positive electrodes, denoted AgxMnOy, in which x and y are such that the manganese ions in the charged or partially charged electrodes cells have an average oxidation state greater than 3.5. The silver manganese oxide electrodes optionally contain silver powder and/or silver foil to assist in current collection at the electrodes and to improve the power capability of the cells or batteries. The invention relates also to a method for preparing AgxMnOy electrodes by decomposition of a permanganate salt, such as AgMnO4, or by the decomposition of KMnO4 or LiMnO4 in the presence of a silver salt.

  18. High Temperature Heat Exchanger Project

    SciTech Connect (OSTI)

    Anthony E. Hechanova, Ph.D.

    2008-09-30

    The UNLV Research Foundation assembled a research consortium for high temperature heat exchanger design and materials compatibility and performance comprised of university and private industry partners under the auspices of the US DOE-NE Nuclear Hydrogen Initiative in October 2003. The objectives of the consortium were to conduct investigations of candidate materials for high temperature heat exchanger componets in hydrogen production processes and design and perform prototypical testing of heat exchangers. The initial research of the consortium focused on the intermediate heat exchanger (located between the nuclear reactor and hydrogen production plan) and the components for the hydrogen iodine decomposition process and sulfuric acid decomposition process. These heat exchanger components were deemed the most challenging from a materials performance and compatibility perspective

  19. Tracing explosive in solvent using quantum cascade laser with pulsed electric discharge system

    SciTech Connect (OSTI)

    Park, Seong-Wook; Tian, Chao; Martini, Rainer; Chen, Gang; Chen, I-chun Anderson

    2014-11-03

    We demonstrated highly sensitive detection of explosive dissolved in solvent with a portable spectroscopy system (Q-MACS) by tracing the explosive byproduct, N{sub 2}O, in combination with a pulsed electric discharge system for safe explosive decomposition. Using Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), the gas was monitored and analyzed by Q-MACS and the presence of the dissolved explosive clearly detected. While HMX presence could be identified directly in the air above the solutions even without plasma, much better results were achieved under the decomposition. The experiment results give an estimated detection limit of 10?ppb, which corresponds to a 15?pg of HMX.

  20. Phase Stability of t;#8242;-Zirconia-Based Thermal Barrier Coatings: Mechanistic Insights

    SciTech Connect (OSTI)

    Krogstad, Jessica A.; Krmer, Stephan; Lipkin, Don M.; Johnson, Curtis A.; Mitchell, David R.G.; Cairney, Julie M.; Levi, Carlos G.

    2011-11-07

    The temperature capability of yttria-stabilized zirconia thermal barrier coatings (TBCs) is ultimately tied to the rate of evolution of the 'nontransformable' t' phase into a depleted tetragonal form predisposed to the monoclinic transformation on cooling. The t' phase, however, has been shown to decompose in a small fraction of the time necessary to form the monoclinic phase. Instead, a modulated microstructure consisting of a coherent array of Y-rich and Y-lean lamellar phases develops early in the process, with mechanistic features suggestive of spinodal decomposition. Coarsening of this microstructure leads to loss of coherency and ultimately transformation into the monoclinic form, making the kinetics of this process, and not the initial decomposition, the critical factor in determining the phase stability of TBCs. Transmission electron microscopy is shown to be essential not only for characterizing the microstructure but also for proper interpretation of X-ray diffraction analysis.

  1. Small nickel nanoparticle arrays from long chain imidazolium ionic liquids

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

    Yang, Mei; Campbell, Paul S.; Santini, Catherine C.; Mudring, Anja -Verena

    2013-11-08

    A series of six long chain alkyl mono- and bi-cationic imidazolium based salts with bis(trifluoromethylsulfonyl)imide (NTf2–) as the anion were synthesized and characterized. Single crystal structure of 1-methyl-3-octadecylimidazolium bis(trifluoromethylsulfonyl)imide could be obtained by X-ray analysis. All these long chain alkyl imidazolium based ILs were applied in the synthesis of nickel nanoparticles via chemical decomposition of an organometallic precursor of nickel. In these media, spontaneous decomposition of Ni(COD)2 (COD = 1,5-cyclooctadiene) in the absence of H2 occurred giving small NPs (≤4 nm) with narrow size distributions. Interestingly, formation of regularly interspaced NP arrays was also observed in long chain ILs. Lastly,more » such array formation could be interesting for potential applications such as carbon nanotube growth.« less

  2. Gamma radiolysis of chlorinated hydrocarbons

    SciTech Connect (OSTI)

    Arbon, R.E.; Mincher, B.J.; Meikrantz, D.H.

    1992-01-01

    This program is the Idaho National Engineering Laboratory (INEL) component of a joint collarborative effort with Lawrence Livermore National Laboratory (LLNL). The purpose of this effort is to demonstrate a viable process for breaking down hazardous halogenated organic wastes to simpler, non-hazardous waste using high energy ionizing radiation. The INEL effort focuses on the use of spent reactor fuel gamma radiation sources to decompose complex wastes such as PCBs. At LLNL, halogenated solvents such as carbon tetrachloride and trichloroethylene are being studied using accelerator radiation sources. The INEL irradiation experiments concentrated on a single PCB congener so that a limited set of decomposition reactions could be studied. The congener 2,2{prime}, 3,3{prime},4,5{prime},6,6{prime} - octachlorobiphenyl was examined following exposure to various gamma doses at the Advanced Test Reactor (AIR) spent fuel pool. The decomposition rates and products in several solvents are discussed. 3 refs.

  3. Gamma radiolysis of chlorinated hydrocarbons

    SciTech Connect (OSTI)

    Arbon, R.E.; Mincher, B.J.; Meikrantz, D.H.

    1992-08-01

    This program is the Idaho National Engineering Laboratory (INEL) component of a joint collarborative effort with Lawrence Livermore National Laboratory (LLNL). The purpose of this effort is to demonstrate a viable process for breaking down hazardous halogenated organic wastes to simpler, non-hazardous waste using high energy ionizing radiation. The INEL effort focuses on the use of spent reactor fuel gamma radiation sources to decompose complex wastes such as PCBs. At LLNL, halogenated solvents such as carbon tetrachloride and trichloroethylene are being studied using accelerator radiation sources. The INEL irradiation experiments concentrated on a single PCB congener so that a limited set of decomposition reactions could be studied. The congener 2,2{prime}, 3,3{prime},4,5{prime},6,6{prime} - octachlorobiphenyl was examined following exposure to various gamma doses at the Advanced Test Reactor (AIR) spent fuel pool. The decomposition rates and products in several solvents are discussed. 3 refs.

  4. On computing stress in polymer systems involving multi-body potentials from molecular dynamics simulation

    SciTech Connect (OSTI)

    Fu, Yao E-mail: jhsong@cec.sc.edu; Song, Jeong-Hoon E-mail: jhsong@cec.sc.edu

    2014-08-07

    Hardy stress definition has been restricted to pair potentials and embedded-atom method potentials due to the basic assumptions in the derivation of a symmetric microscopic stress tensor. Force decomposition required in the Hardy stress expression becomes obscure for multi-body potentials. In this work, we demonstrate the invariance of the Hardy stress expression for a polymer system modeled with multi-body interatomic potentials including up to four atoms interaction, by applying central force decomposition of the atomic force. The balance of momentum has been demonstrated to be valid theoretically and tested under various numerical simulation conditions. The validity of momentum conservation justifies the extension of Hardy stress expression to multi-body potential systems. Computed Hardy stress has been observed to converge to the virial stress of the system with increasing spatial averaging volume. This work provides a feasible and reliable linkage between the atomistic and continuum scales for multi-body potential systems.

  5. Feature recognition applications in mesh generation

    SciTech Connect (OSTI)

    Tautges, T.J.; Liu, S.S.; Lu, Y.; Kraftcheck, J.; Gadh, R.

    1997-06-01

    The use of feature recognition as part of an overall decomposition-based hexahedral meshing approach is described in this paper. The meshing approach consists of feature recognition, using a c-loop or hybrid c-loop method, and the use of cutting surfaces to decompose the solid model. These steps are part of an iterative process, which proceeds either until no more features can be recognized or until the model has been completely decomposed into meshable sub-volumes. This method can greatly reduce the time required to generate an all-hexahedral mesh, either through the use of more efficient meshing algorithms on more of the geometry or by reducing the amount of manual decomposition required to mesh a volume.

  6. Laser assisted high entropy alloy coating on aluminum: Microstructural evolution

    SciTech Connect (OSTI)

    Katakam, Shravana; Joshi, Sameehan S.; Mridha, Sanghita; Mukherjee, Sundeep; Dahotre, Narendra B.

    2014-09-14

    High entropy alloy (Al-Fe-Co-Cr-Ni) coatings were synthesized using laser surface engineering on aluminum substrate. Electron diffraction analysis confirmed the formation of solid solution of body centered cubic high entropy alloy phase along with phases with long range periodic structures within the coating. Evolution of such type of microstructure was a result of kinetics associated with laser process, which generates higher temperatures and rapid cooling resulting in retention of high entropy alloy phase followed by reheating and/or annealing in subsequent passes of the laser track giving rise to partial decomposition. The partial decomposition resulted in formation of precipitates having layered morphology with a mixture of high entropy alloy rich phases, compounds, and long range ordered phases.

  7. The tensor hierarchy algebra

    SciTech Connect (OSTI)

    Palmkvist, Jakob

    2014-01-15

    We introduce an infinite-dimensional Lie superalgebra which is an extension of the U-duality Lie algebra of maximal supergravity in D dimensions, for 3 ? D ? 7. The level decomposition with respect to the U-duality Lie algebra gives exactly the tensor hierarchy of representations that arises in gauge deformations of the theory described by an embedding tensor, for all positive levels p. We prove that these representations are always contained in those coming from the associated Borcherds-Kac-Moody superalgebra, and we explain why some of the latter representations are not included in the tensor hierarchy. The most remarkable feature of our Lie superalgebra is that it does not admit a triangular decomposition like a (Borcherds-)Kac-Moody (super)algebra. Instead the Hodge duality relations between level p and D ? 2 ? p extend to negative p, relating the representations at the first two negative levels to the supersymmetry and closure constraints of the embedding tensor.

  8. Thermocatalytic CO{sub 2}-Free Production of Hydrogen from Hydrocarbon Fuels - Final Report for the Period August 1999 - September 2000

    SciTech Connect (OSTI)

    Nazim Muradov, Ph.D.

    2000-10-01

    The overall objective of this work is to develop a novel process for CO{sub 2}-free production of hydrogen via thermocatalytic decomposition (pyrolysis) of hydrocarbon fuels as a viable alternative to the conventional processes of methane steam reforming or partial oxidation. The objective of Phase I work was to demonstrate the technical feasibility of CO{sub 2}-free production of hydrogen and carbon from different hydrocarbons, including methane, propane and gasoline.

  9. Radiation chemistry in the reprocessing and recycling of spent nuclear fuels

    SciTech Connect (OSTI)

    Bruce J. Mincher

    2015-04-01

    The interaction of ionizing radiation with solvent extraction solutions results in the ionization, excitation, and decay to neutral radicals of mainly diluent molecules. These produced reactive species diffuse into the bulk solution to react with solvent extraction ligands. Ligand reactions often result in deleterious effects such as loss in ligand concentration or the production of decomposition products that may also be complexing agents. This often interferes with desired separations. The common radiolysis reactions and their potential effects on solvent extraction are reviewed here.

  10. Submission Format for IMS2004 (Title in 18-point Times font)

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

    Fault Signal Detection - Fourier Transformation vs. Wavelet Decomposition Techniques using Synthesized Data Zhan Wang 1 , Stephen McConnell 1 , Robert S. Balog 1 and Jay Johnson 2 1 Texas A&M University, College Station, Texas, 77843, USA 2 Sandia National Laboratory, Albuquerque, New Mexico, 87185, USA Abstract - Arc faults are a significant reliability and safety concern for photovoltaic (PV) systems and can cause intermittent operation, system failure, electrical shock hazard, and even

  11. Runtime System Library for Parallel Weather Modules

    Energy Science and Technology Software Center (OSTI)

    1997-07-22

    RSL is a Fortran-callable runtime library for use in implementing regular-grid weather forecast models, with nesting, on scalable distributed memory parallel computers. It provides high-level routines for finite-difference stencil communications and inter-domain exchange of data for nested forcing and feedback. RSL supports a unique point-wise domain-decomposition strategy to facilitate load-balancing.

  12. Cyanide treatment options in coke plants

    SciTech Connect (OSTI)

    Minak, H.P.; Lepke, P.

    1997-12-31

    The paper discusses the formation of cyanides in coke oven gas and describes and compares waste processing options. These include desulfurization by aqueous ammonia solution, desulfurization using potash solution, desulfurization in oxide boxes, decomposition of NH{sub 3} and HCN for gas scrubbing. Waste water treatment methods include chemical oxidation, precipitation, ion exchange, reverse osmosis, and biological treatment. It is concluded that biological treatment is the most economical process, safe in operation and requires a minimum of manpower.

  13. Effects of energy related activities on the stress-sensitive microbial processes in mangrove detrital food webs

    SciTech Connect (OSTI)

    Fell, J.W.

    1984-01-01

    Nutrient flows from leaf litter decomposition are evaluated in terms of their contributions to the ecosystem. The roles of the stress sensitive microbial processes are being determined. Emphasis is on the following aspects: (1) nitrogen immobilization; (2) transport of particulate carbon to the estuary; (3) role of flocculent materials produced from leachates; (4) invertebrate utilization of carbon and nitrogen flows; and (5) possible effects on these systems if the Gulf oil spill reaches the south Florida coast. 19 references. (ACR)

  14. Thermal Conversion of Methane to Acetylene Final Report

    SciTech Connect (OSTI)

    Fincke, J.R.; Anderson, R.P.; Hyde, T.; Wright, R.; Bewley, R.; Haggard, D.C.; Swank, W.D.

    2000-01-31

    This report describes the experimental demonstration of a process for the direct thermal conversion of methane to acetylene. The process utilizes a thermal plasma heat source to dissociation products react to form a mixture of acetylene and hydrogen. The use of a supersonic expansion of the hot gas is investigated as a method of rapidly cooling (quenching) the product stream to prevent further reaction or thermal decomposition of the acetylene which can lower the overall efficiency of the process.

  15. SREL Reprint #3028

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

    8 Detrital lipid dynamics in a blackwater stream: comparison of fast and slow decomposing leaves J. Vaun McArthur and Gary L. Mills Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802, USA Abstract: Temporal changes in eight different lipid classes (hydrocarbons, wax esters, triglycerides, fatty acids, alcohols, sterols, monoglycerides, diglycerides, and polar lipids) were followed during decomposition of two different species of leaves (water oak, Quercus nigra, and

  16. Soil Organic Carbon Degradation, Barrow, 2013-2014

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

    Gu, Baohua; Yang, Ziming

    2015-03-30

    This dataset provides information about soil organic carbon decomposition in Barrow soil incubation studies. The soil cores were collected from low-center polygon (Area A) and were incubated in the laboratory at different temperatures for up to 60 days. Transformations of soil organic carbon were characterized by UV and FT-IR, and small organic acids in water-soluble carbons were quantified by ion chromatography during the incubation

  17. SAND2014-4277C © Copyright 2013, First Solar, Inc.

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

    277C © Copyright 2013, First Solar, Inc. 2 © Copyright 2013, First Solar, Inc. Summary * This is a preview of work of forthcoming publications (PVSC 40 oral presentation and paper, Sandia technical report) * Estimating plane of array (POA) irradiance often requires a sequence of models: - Decomposition: GHI to direct normal irradiance (DNI) and diffuse horizontal irradiance (DHI) - Transposition: GHI, DNI and DHI to total irradiance in POA * Many choices are available for each step - E.g.,

  18. The wavelet/scalar quantization compression standard for digital fingerprint images

    SciTech Connect (OSTI)

    Bradley, J.N.; Brislawn, C.M.

    1994-04-01

    A new digital image compression standard has been adopted by the US Federal Bureau of Investigation for use on digitized gray-scale fingerprint images. The algorithm is based on adaptive uniform scalar quantization of a discrete wavelet transform image decomposition and is referred to as the wavelet/scalar quantization standard. The standard produces archival quality images at compression ratios of around 20:1 and will allow the FBI to replace their current database of paper fingerprint cards with digital imagery.

  19. ARM - Publications: Science Team Meeting Documents

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

    A Successive Order of Scattering Model for Vector (Polarized) Radiative Transfer Min, Q. and Duan, M., State University of New York at Albany Thirteenth Atmospheric Radiation Measurement (ARM) Science Team Meeting A full vector radiative transfer model for vertically inhomogeneous plane-parallel media has been developed by using the successive order of scattering approach. In this model, a fast analytical expansion of Fourier decomposition is implemented and an exponent-linear assumption is used

  20. Hydrolyzable polyester resins, varnishes and coating compositions containing the same

    DOE Patents [OSTI]

    Yamamori, Naoki (Minoo, JP); Yokoi, Junji (Nara, JP); Yoshikawa, Motoyoshi (Nara, JP)

    1984-01-01

    Preparation of hydrolyzable polyester resin comprising reacting polycarboxylic acid and polyhydric alcohol components, which is characterized by using, as at least part of said polyhydric alcohol component, a metallic salt of hydroxy carboxylic acid of the formula defined and effecting the polycondensation at a temperature which is no more than the decomposition temperature of said metallic salt. The polyester resins are useful as resinous vehicle of varnishes and antifouling paints.

  1. Catalytic destruction of perchlorate in ferric chloride and hydrochloric acid solution with control of temperature, pressure and chemical reagents

    DOE Patents [OSTI]

    Gu, Baohua; Cole, David R.; Brown, Gilbert M.

    2004-10-05

    A method is described to decompose perchlorate in a FeCl.sub.3 /HCl aqueous solution such as would be used to regenerate an anion exchange resin used to remove perchlorate. The solution is mixed with a reducing agent, preferably an organic alcohol and/or ferrous chloride, and can be heated to accelerate the decomposition of perchlorate. Lower temperatures may be employed if a catalyst is added.

  2. EIA - Greenhouse Gas Emissions Overview

    Gasoline and Diesel Fuel Update (EIA)

    A2. Glossary Acid stabilization: A circumstance where the pH of the waste mixture in an animal manure management system is maintained near 7.0, optimal conditions for methane production. Aerobic bacteria: Microorganisms living, active, or occurring only in the presence of oxygen. Aerobic decomposition: The breakdown of a molecule into simpler molecules or atoms by microorganisms under favorable conditions of oxygenation. Aerosols: Airborne particles. Afforestation: Planting of new forests on

  3. Hand-Held Analyzer Quickly Detects Buried Human Remains - Energy Innovation

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

    Portal Early Stage R&D Early Stage R&D Advanced Materials Advanced Materials Find More Like This Return to Search Hand-Held Analyzer Quickly Detects Buried Human Remains Oak Ridge National Laboratory Contact ORNL About This Technology Technology Marketing SummaryA lightweight hand-held analyzer invented by ORNL researchers uses visual and auditory cues to quickly alert investigators to the presence of buried human remains. The Lightweight Analyzer for Buried Remains And Decomposition

  4. Method of preparing silicon from sodium fluosilicate

    DOE Patents [OSTI]

    Schmidt, Frederick A. (Ames, IA); Rehbein, David (Ames, IA); Chiotti, Premo (Ames, IA)

    1984-01-01

    A process for preparing high purity silicon metal from Na.sub.2 SiF.sub.6 (sodium fluosilicate). The sodium fluosilicate is heated to decomposition temperature to form NaF, which retains most of the impurities, and gaseous SiF.sub.4. The SiF.sub.4 is then reduced by the bomb reduction method using a reductant having a low packing density.

  5. Lessons Learned: Devolping Thermochemical Cycles for Solar Heat Storage Applications

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

    Developing Thermochemical Cycles for Solar Heat Storage Applications General Atomics Bunsen Wong IFT\P2013-001 Workshop on TES for CSP - January 8, 2013 Outline * Introduction * Case Study I: Solid Oxide Decomposition * Case Study II: Sulfur Based Cycle * Conclusions 2 Solar heat is used to drive the reduction step of a thermochemical cycle 3 Thermal Reduction Chemical Storage Re- oxidation * Energy is stored in chemical bonds * Energy is recovered upon chemical re-oxidation heat heat

  6. Treating tar sands formations with dolomite

    DOE Patents [OSTI]

    Vinegar, Harold J.; Karanikas, John Michael

    2010-06-08

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

  7. A Reduced-Order Model of Transport Phenomena for Power Plant Simulation

    SciTech Connect (OSTI)

    Paul Cizmas; Brian Richardson; Thomas Brenner; Raymond Fontenot

    2009-09-30

    A reduced-order model based on proper orthogonal decomposition (POD) has been developed to simulate transient two- and three-dimensional isothermal and non-isothermal flows in a fluidized bed. Reduced-order models of void fraction, gas and solids temperatures, granular energy, and z-direction gas and solids velocity have been added to the previous version of the code. These algorithms are presented and their implementation is discussed. Verification studies are presented for each algorithm. A number of methods to accelerate the computations performed by the reduced-order model are presented. The errors associated with each acceleration method are computed and discussed. Using a combination of acceleration methods, a two-dimensional isothermal simulation using the reduced-order model is shown to be 114 times faster than using the full-order model. In the pursue of achieving the objectives of the project and completing the tasks planned for this program, several unplanned and unforeseen results, methods and studies have been generated. These additional accomplishments are also presented and they include: (1) a study of the effect of snapshot sampling time on the computation of the POD basis functions, (2) an investigation of different strategies for generating the autocorrelation matrix used to find the POD basis functions, (3) the development and implementation of a bubble detection and tracking algorithm based on mathematical morphology, (4) a method for augmenting the proper orthogonal decomposition to better capture flows with discontinuities, such as bubbles, and (5) a mixed reduced-order/full-order model, called point-mode proper orthogonal decomposition, designed to avoid unphysical due to approximation errors. The limitations of the proper orthogonal decomposition method in simulating transient flows with moving discontinuities, such as bubbling flows, are discussed and several methods are proposed to adapt the method for future use.

  8. Annealed CVD molybdenum thin film surface

    DOE Patents [OSTI]

    Carver, Gary E. (Tucson, AZ); Seraphin, Bernhard O. (Tucson, AZ)

    1984-01-01

    Molybdenum thin films deposited by pyrolytic decomposition of Mo(CO).sub.6 attain, after anneal in a reducing atmosphere at temperatures greater than 700.degree. C., infrared reflectance values greater than reflectance of supersmooth bulk molybdenum. Black molybdenum films deposited under oxidizing conditions and annealed, when covered with an anti-reflecting coating, approach the ideal solar collector characteristic of visible light absorber and infrared energy reflector.

  9. September 2015 Most Viewed Documents for Fossil Fuels | OSTI, US Dept of

    Office of Scientific and Technical Information (OSTI)

    Energy, Office of Scientific and Technical Information September 2015 Most Viewed Documents for Fossil Fuels EXPERIMENTAL AND THEORETICAL DETERMINATION OF HEAVY OIL VISCOSITY UNDER RESERVOIR CONDITIONS Dr. Jorge Gabitto; Maria Barrufet (2003) 141 Decomposition of calcium sulfate: a review of the literature. [62 refs] Swift, W M; Panek, A F; Smith, G W; Vogel, G J; Jonke, A A (1976) 122 Practical hot oiling and hot watering for paraffin control Mansure, A.J. [Sandia National Labs.,

  10. DIY2 () | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Software: DIY2 Citation Details Software Request Title: DIY2 DIY2 is a data parallel out-of-core library, written in C++. It provides facilities for domain decomposition into blocks and abstracts both neighborhood and global communication patterns to the level of blocks. DIY2 supports automatic threading. It also provides a data serialization mechanism, using which it allows for automatic movement of blocks in and out of core. Authors: Morozov, Dmitriy ; Peterka, Tom Publication Date: 2015-05-01

  11. Method for producing high carrier concentration p-Type transparent conducting oxides

    DOE Patents [OSTI]

    Li, Xiaonan (Evergreen, CO); Yan, Yanfa (Littleton, CO); Coutts, Timothy J. (Golden, CO); Gessert, Timothy A. (Conifer, CO); Dehart, Clay M. (Westminster, CO)

    2009-04-14

    A method for producing transparent p-type conducting oxide films without co-doping plasma enhancement or high temperature comprising: a) introducing a dialkyl metal at ambient temperature and a saturated pressure in a carrier gas into a low pressure deposition chamber, and b) introducing NO alone or with an oxidizer into the chamber under an environment sufficient to produce a metal-rich condition to enable NO decomposition and atomic nitrogen incorporation into the formed transparent metal conducting oxide.

  12. High temperature electrolysis for syngas production

    DOE Patents [OSTI]

    Stoots, Carl M.; O'Brien, James E.; Herring, James Stephen; Lessing, Paul A.; Hawkes, Grant L.; Hartvigsen, Joseph J.

    2011-05-31

    Syngas components hydrogen and carbon monoxide may be formed by the decomposition of carbon dioxide and water or steam by a solid-oxide electrolysis cell to form carbon monoxide and hydrogen, a portion of which may be reacted with carbon dioxide to form carbon monoxide. One or more of the components for the process, such as steam, energy, or electricity, may be provided using a nuclear power source.

  13. DE-FE0010160 | netl.doe.gov

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

    Advanced Hydrate Reservoir Modeling Using Rock Physics Techniques Last Reviewed 11/27/2015 DE-FE0010160 Goal The primary goal of this research is to develop analytical techniques capable of quantitatively evaluating the nature of methane hydrate reservoir systems through modeling of their acoustic response using techniques that integrate rock physics theory, amplitude analysis, and spectral decomposition. Performers Fugro GeoConsulting, Inc., Houston TX Background Past efforts under the

  14. Discovery of novel hydrogen storage materials: an atomic scale

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

    computational approach | Energy Frontier Research Centers Discovery of novel hydrogen storage materials: an atomic scale computational approach Home Author: C. Wolverton, D. J. Siegel, A. R. Akbarzadeh, V. Ozolins Year: 2008 Abstract: Practical hydrogen storage for mobile applications requires materials that exhibit high hydrogen densities, low decomposition temperatures, and fast kinetics for absorption and desorption. Unfortunately, no reversible materials are currently known that possess

  15. Energy Storage

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

    Energy Storage - Creation of 3D mesh from surface and background meshes using conformal decomposition finite-element method (CDFEM) for a LiCoO2 cathode: (a) reconstructed surface mesh from Avizo for particle phase, (b) background mesh for CDFEM, and (c) resultant 3D mesh for particle and electrolyte phases from CDFEM. Permalink Gallery Sandia Wins Funding for Two DOE-EERE Computer-Aided Battery-Safety R&D Projects Analysis, Capabilities, Computational Modeling & Simulation, Design,

  16. A Novel Method of Injection Molding Titanium Components

    SciTech Connect (OSTI)

    Nyberg, Eric A.; Simmons, Kevin L.; Weil, K. Scott

    2005-05-01

    We have developed a unique blend of powder injection molding feedstock materials in which only a small volume fraction of binder (< 8%) is required; the remainder of the mixture consists of the metal powder and a solid aromatic solvent. Because of the nature of the decomposition in the binder system and the relatively small amount used, the binder is eliminated almost completely from the pre-sintered component during the initial stage of a two-step heat treatment process.

  17. Two step novel hydrogen system using additives to enhance hydrogen release from the hydrolysis of alane and activated aluminum

    DOE Patents [OSTI]

    Zidan, Ragaiy; Teprovich, Joseph A.; Motyka, Theodore

    2015-12-01

    A system for the generation of hydrogen for use in portable power systems is set forth utilizing a two-step process that involves the thermal decomposition of AlH.sub.3 (10 wt % H.sub.2) followed by the hydrolysis of the activated aluminum (Al*) byproduct to release additional H.sub.2. Additionally, a process in which water is added directly without prior history to the AlH.sub.3:PA composite is also disclosed.

  18. NREL: Biomass Research - Seonah Kim, Ph.D.

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

    Seonah Kim, Ph.D. Photo of Seonah Kim Seonah Kim is a scientist in the Biochemical Process Research team in the National Bioenergy Center at the National Renewable Energy Laboratory (NREL). Her research background combines extensive experience in both classical molecular dynamics simulations and quantum mechanical modeling of transition states. She has been working on understanding and designing catalysts for the decomposition of both lignin and cellulose. At NREL she has developed catalytic

  19. Membrane for hydrogen recovery from streams containing hydrogen sulfide

    DOE Patents [OSTI]

    Agarwal, Pradeep K.

    2007-01-16

    A membrane for hydrogen recovery from streams containing hydrogen sulfide is provided. The membrane comprises a substrate, a hydrogen permeable first membrane layer deposited on the substrate, and a second membrane layer deposited on the first layer. The second layer contains sulfides of transition metals and positioned on the on a feed side of the hydrogen sulfide stream. The present invention also includes a method for the direct decomposition of hydrogen sulfide to hydrogen and sulfur.

  20. Co-Al mixed metal oxides/carbon nanotubes nanocomposite prepared via a precursor route and enhanced catalytic property

    SciTech Connect (OSTI)

    Fan Guoli; Wang Hui; Xiang Xu; Li Feng

    2013-01-15

    The present work reported the synthesis of Co-Al mixed metal oxides/carbon nanotubes (CoAl-MMO/CNT) nanocomposite from Co-Al layered double hydroxide/CNTs composite precursor (CoAl-LDH/CNT). The materials were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), low temperature nitrogen adsorption-desorption experiments, thermogravimetric and differential thermal analyses (TG-DTA), Raman spectra and X-ray photoelectron spectroscopy (XPS). The results revealed that in CoAl-MMO/CNT nanocomposite, the nanoparticles of cobalt oxide (CoO) and Co-containing spinel-type complex metal oxides could be well-dispersed on the surface of CNTs, thus forming the heterostructure of CoAl-MMO and CNTs. Furthermore, as-synthesized CoAl-MMO/CNT nanocomposite was utilized as additives for catalytic thermal decomposition of ammonium perchlorate (AP). Compared to those for pure AP and CoAl-MMO, the peak temperature of AP decomposition for CoAl-MMO/CNT was significantly decreased, which is attributed to the novel heterostructure and synergistic effect of multi-component metal oxides of nanocomposite. - Graphical abstract: Hybrid Co-Al mixed metal oxides/carbon nanotubes nanocomposite showed the enhanced catalytic activity in the thermal decomposition of ammonium perchlorate, as compared to carbon nanotubes and pure Co-Al mixed metal oxides. Highlights: Black-Right-Pointing-Pointer Co-Al mixed metal oxides/carbon nanotubes nanocomposite was synthesized. Black-Right-Pointing-Pointer Co-Al mixed metal oxides consisted of cobalt oxide and Co-containing spinels. Black-Right-Pointing-Pointer Nanocomposite exhibited excellent catalytic activity for the decomposition of AP. Black-Right-Pointing-Pointer The superior catalytic property is related to novel heterostructure and composition.

  1. Recent Advances and Future Challenges in the Modeling and Simulations of

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

    the injection of Urea-Water-Solution for Automotive SCR Systems | Department of Energy Advances and Future Challenges in the Modeling and Simulations of the injection of Urea-Water-Solution for Automotive SCR Systems Recent Advances and Future Challenges in the Modeling and Simulations of the injection of Urea-Water-Solution for Automotive SCR Systems The role of CFD modeling to optimize UWS injection and decomposition was presented. PDF icon deer09_aburamadan.pdf More Documents &

  2. EST-380-NEDA | netl.doe.gov

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

    EST-380-NEDA Characterization and Decomposition Kinetic Studies of Methane Hydrate in Host Sediments under Subsurface Mimic Conditions EST-380-NEDA Last Reviewed 02/17/2010 Project Goal The purpose of this study is to establish sediment lithology and quantification of methane in hydrates hosted in fine-grained sediments from the Gulf of Mexico (GoM), a marine site of methane hydrate occurrence. The results will help establish a correlation between laboratory data and hydrate accumulation field

  3. Science Highlights

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

    Highlights Science Highlights Science highlights feature research conducted by staff and users at the ALS. If a Power Point summary slide or a PDF handout of the highlight is available, you will find it linked beneath the highlight listing and on the highlight's page. You may also print a version of a highlight by clicking the print icon associated with each highlight. Manganese Reduction-Oxidation Drives Plant Debris Decomposition Print Monday, 22 February 2016 00:00 ALS research has shown that

  4. An approximation technique for jet impingement flow

    SciTech Connect (OSTI)

    Najafi, Mahmoud; Fincher, Donald; Rahni, Taeibi; Javadi, KH.; Massah, H.

    2015-03-10

    The analytical approximate solution of a non-linear jet impingement flow model will be demonstrated. We will show that this is an improvement over the series approximation obtained via the Adomian decomposition method, which is itself, a powerful method for analysing non-linear differential equations. The results of these approximations will be compared to the Runge-Kutta approximation in order to demonstrate their validity.

  5. Energy Intensity Indicators: Methodology Downloads | Department of Energy

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

    Indicators: Methodology Downloads Energy Intensity Indicators: Methodology Downloads The files listed below contain methodology documentation and related studies that support the information presented on this website. The files are available to view and/or download as Adobe Acrobat PDF files. PDF icon Energy Indicators System: Index Construction Methodology PDF icon Changing the Base Year for the Index PDF icon "A Note on the Fisher Ideal Index Decomposition for Structural Change in Energy

  6. Development and Field Demonstrations of the Low NO2 ACCRT’ System for

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

    Retrofit Applications | Department of Energy Demonstrations of the Low NO2 ACCRT’ System for Retrofit Applications Development and Field Demonstrations of the Low NO2 ACCRT’ System for Retrofit Applications The system reduces PM using a passively regenerating DPF and reduces NO2 by dosing a small quantity of fuel over a decomposition catalyst . PDF icon deer09_joshi.pdf More Documents & Publications Diesel Particulate Filter Technology for Low-Temperature and Low-NOx/PM Applications

  7. Surfactant process for promoting gas hydrate formation and application of the same

    DOE Patents [OSTI]

    Rogers, Rudy E. (Starkville, MS); Zhong, Yu (Brandon, MS)

    2002-01-01

    This invention relates to a method of storing gas using gas hydrates comprising forming gas hydrates in the presence of a water-surfactant solution that comprises water and surfactant. The addition of minor amounts of surfactant increases the gas hydrate formation rate, increases packing density of the solid hydrate mass and simplifies the formation-storage-decomposition process of gas hydrates. The minor amounts of surfactant also enhance the potential of gas hydrates for industrial storage applications.

  8. Soil Organic Carbon Degradation, Barrow, 2013-2014

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

    Gu, Baohua; Yang, Ziming

    This dataset provides information about soil organic carbon decomposition in Barrow soil incubation studies. The soil cores were collected from low-center polygon (Area A) and were incubated in the laboratory at different temperatures for up to 60 days. Transformations of soil organic carbon were characterized by UV and FT-IR, and small organic acids in water-soluble carbons were quantified by ion chromatography during the incubation

  9. Thermal shock resistance ceramic insulator (Patent) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Patent: Thermal shock resistance ceramic insulator Citation Details In-Document Search Title: Thermal shock resistance ceramic insulator Thermal shock resistant cermet insulators containing 0.1-20 volume % metal present as a dispersed phase. The insulators are prepared by a process comprising the steps of (a) providing a first solid phase mixture of a ceramic powder and a metal precursor; (b) heating the first solid phase mixture above the minimum decomposition temperature of the metal precursor

  10. Three-dimensional discrete ordinates reactor assembly calculations on GPUs

    SciTech Connect (OSTI)

    Evans, Thomas M; Joubert, Wayne; Hamilton, Steven P; Johnson, Seth R; Turner, John A; Davidson, Gregory G; Pandya, Tara M

    2015-01-01

    In this paper we describe and demonstrate a discrete ordinates sweep algorithm on GPUs. This sweep algorithm is nested within a multilevel comunication-based decomposition based on energy. We demonstrated the effectiveness of this algorithm on detailed three-dimensional critical experiments and PWR lattice problems. For these problems we show improvement factors of 4 6 over conventional communication-based, CPU-only sweeps. These sweep kernel speedups resulted in a factor of 2 total time-to-solution improvement.

  11. Microsoft PowerPoint - Sacci_ChemComm-2014.ppt [Compatibility Mode]

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

    Investigating Solid Electrolyte Formation and Growth at the Nano-scale" The SEI is a nm-scaled passivating layer that forms locally at the anode/electrolyte interface as a result of electrolyte decomposition during the initial charging cycle. The ongoing formation of radicals (due to the highly negative reduction potential of Li, -3 V) can lead to disordered SEIs. Controlling the SEI's properties essential to the development longer lasting and safer Li-ion batteries; however, its formation

  12. Visapult: A Prototype Remote and Distributed Visualization Application and

    Office of Scientific and Technical Information (OSTI)

    Framework (Conference) | SciTech Connect Conference: Visapult: A Prototype Remote and Distributed Visualization Application and Framework Citation Details In-Document Search Title: Visapult: A Prototype Remote and Distributed Visualization Application and Framework We describe an approach used for implementing a highly efficient and scalable method for direct volume rendering. Our approach uses a pipelined-parallel decomposition composed of parallel computers and commodity desktop hardware.

  13. Water Outgassing from PBX-9502 powder by isoconversional thermal analysis

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect Water Outgassing from PBX-9502 powder by isoconversional thermal analysis Citation Details In-Document Search Title: Water Outgassing from PBX-9502 powder by isoconversional thermal analysis Temperature programmed desorption/decomposition (TPD) were performed on PBX-9502 after 3 hours of vacuum pump. TPD data were analyzed by the technique of isoconversional analysis to obtain outgassing kinetics and moisture content of PBX-9502 powder as well as to

  14. Zeolite-templated Pt/C electrocatalysts (Journal Article) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Zeolite-templated Pt/C electrocatalysts Citation Details In-Document Search Title: Zeolite-templated Pt/C electrocatalysts In an effort to reduce the amount of platinum required in low temperature fuel cells, we have prepared electrocatalysts of platinum nanoparticles-on-carbon through zeolite-templating methods. Several different zeolite structure-types, as well as clays and mesoporous silicas were investigated as hosts for the preparation of small Pt clusters through thermal decomposition of

  15. ASC eNews Quarterly Newsletter

    National Nuclear Security Administration (NNSA)

    September 2014 Contents: (To go directly to an article, click on its title below.) The Meisner Minute New Modeling Code Accurately Calculates Opacity at Record Speeds New Fluid Model Offers Significant Improvement over Legacy Model A New Parallel Decomposition Tool for SIERRA Modeling Exploring the use of Topology Optimization for Component Designs Progress on the High-Order/Low-Order Algorithm for Thermal Radiative Transport Testing a New ASC Code Laser Package ASC Salutes Manuel Vigil Recent

  16. Hybrid sulfur cycle operation for high-temperature gas-cooled reactors

    DOE Patents [OSTI]

    Gorensek, Maximilian B

    2015-02-17

    A hybrid sulfur (HyS) cycle process for the production of hydrogen is provided. The process uses a proton exchange membrane (PEM) SO.sub.2-depolarized electrolyzer (SDE) for the low-temperature, electrochemical reaction step and a bayonet reactor for the high-temperature decomposition step The process can be operated at lower temperature and pressure ranges while still providing an overall energy efficient cycle process.

  17. Stanford Nitrogen Group | Department of Energy

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

    Stanford Nitrogen Group National Clean Energy Business Plan Competition Stanford Nitrogen Group Stanford University The Stanford Nitrogen Group developed a new wastewater treatment process for the removal and recovery of energy from waste nitrogen (i.e. ammonia). This process improves the efficiency and lowers the cost of nitrogen treatment. The process is termed the Coupled Aerobic-anoxic Nitrous Decomposition Operation (CANDO) and consists of 2 principal steps: biological conversion of ammonia

  18. NO reduction using sublimation of cyanuric acid

    DOE Patents [OSTI]

    Perry, R.A.

    1993-01-19

    A method of reducing the NO content of a gas stream comprises contacting the gas stream with an amount of HNCO at a temperature effective for heat-induced decomposition of HNCO, said amount and temperature being effective for resultant lowering of the NO content of the gas stream, said solid agent being particulate and having a particle size of less than 90 [mu]m.

  19. No reduction using sublimation of cyanuric acid

    DOE Patents [OSTI]

    Perry, Robert A.

    1993-01-01

    A method of reducing the NO content of a gas stream comprises contacting the gas stream with an amount of HNCO at a temperature effective for heat-induced decomposition of HNCO, said amount and temperature being effective for resultant lowering of the NO content of the gas stream, said solid agent being particulate and having a particle size of less than 90 .mu.m.

  20. NO reduction using sublimation of cyanuric acid

    DOE Patents [OSTI]

    Perry, R.A.

    1996-05-21

    A method of reducing the NO content of a gas stream comprises contacting the gas stream with an amount of HNCO at a temperature effective for heat-induced decomposition of cyanuric acid, said amount and temperature being effective for the resultant lowering of the NO content of the gas stream, said cyanuric acid being particulate and having a particle size of less than 90 {micro}m. 1 fig.

  1. No reduction using sublimination of cyanuric acid

    DOE Patents [OSTI]

    Perry, Robert A.

    1996-01-01

    A method of reducing the NO content of a gas stream comprises contacting the gas stream with an amount of HNCO at a temperature effective for heat-induced decomposition of cyanuric acid, said amount and temperature being effective for the resultant lowering of the NO content of the gas stream, said cyanuric acid being particulate and having a particle size of less than 90 .mu.m.

  2. No reduction using sublimation of cyanuric acid

    DOE Patents [OSTI]

    Perry, Robert

    1989-01-01

    An arrangement for reducing the NO content of a gas stream comprises contacting the gas stream with HNCO at a temperature effective for heat induced decomposition of HNCO and for resultant lowering of the NO content of the gas stream. Preferably, the HNCO is generated by sublimation of cyanuric acid and CO or other H-atom generating species is also present or added to the gas stream.

  3. Stanford Nitrogen Group | Department of Energy

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

    Stanford Nitrogen Group National Clean Energy Business Plan Competition Stanford Nitrogen Group Stanford University The Stanford Nitrogen Group developed a new wastewater treatment process for the removal and recovery of energy from waste nitrogen (i.e. ammonia). This process improves the efficiency and lowers the cost of nitrogen treatment. The process is termed the Coupled Aerobic-anoxic Nitrous Decomposition Operation (CANDO) and consists of 2 principal steps: biological conversion of ammonia

  4. Studies on the thermal breakdown of common Li-ion battery electrolyte components

    SciTech Connect (OSTI)

    Lamb, Joshua; Orendorff, Christopher J.; Roth, Emanuel Peter; Langendorf, Jill Louise

    2015-08-06

    While much attention is paid to the impact of the active materials on the catastrophic failure of lithium ion batteries, much of the severity of a battery failure is also governed by the electrolytes used, which are typically flammable themselves and can decompose during battery failure. The use of LiPF6 salt can be problematic as well, not only catalyzing electrolyte decomposition, but also providing a mechanism for HF production. This work evaluates the safety performance of the common components ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC) in the context of the gasses produced during thermal decomposition, looking at both the quantity and composition of the vapor produced. EC and DEC were found to be the largest contributors to gas production, both producing upwards of 1.5 moles of gas/mole of electrolyte. DMC was found to be relatively stable, producing very little gas regardless of the presence of LiPF6. EMC was stable on its own, but the addition of LiPF6 catalyzed decomposition of the solvent. As a result, while gas analysis did not show evidence of significant quantities of any acutely toxic materials, the gasses themselves all contained enough flammable components to potentially ignite in air.

  5. Studies on the thermal breakdown of common Li-ion battery electrolyte components

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

    Lamb, Joshua; Orendorff, Christopher J.; Roth, Emanuel Peter; Langendorf, Jill Louise

    2015-08-06

    While much attention is paid to the impact of the active materials on the catastrophic failure of lithium ion batteries, much of the severity of a battery failure is also governed by the electrolytes used, which are typically flammable themselves and can decompose during battery failure. The use of LiPF6 salt can be problematic as well, not only catalyzing electrolyte decomposition, but also providing a mechanism for HF production. This work evaluates the safety performance of the common components ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC) in the context of the gasses producedmore » during thermal decomposition, looking at both the quantity and composition of the vapor produced. EC and DEC were found to be the largest contributors to gas production, both producing upwards of 1.5 moles of gas/mole of electrolyte. DMC was found to be relatively stable, producing very little gas regardless of the presence of LiPF6. EMC was stable on its own, but the addition of LiPF6 catalyzed decomposition of the solvent. As a result, while gas analysis did not show evidence of significant quantities of any acutely toxic materials, the gasses themselves all contained enough flammable components to potentially ignite in air.« less

  6. Thermal Stability Of Formohydroxamic Acid

    SciTech Connect (OSTI)

    Fondeur, F. F.; Rudisill, T. S.

    2011-10-21

    The thermal stability of formohydroxamic acid (FHA) was evaluated to address the potential for exothermic decomposition during storage and its use in the uranium extraction process. Accelerating rate calorimetry showed rapid decomposition at a temperature above 65 {degree}?C; although, the rate of pressure rise was greater than two orders of magnitude less than the lower bound for materials which have no explosive properties with respect to transportation. FHA solutions in water and nitric acid did not reach runaway conditions until 150 {degree}?C. Analysis by differential scanning calorimetry showed that FHA melted at 67 {degree}?C and thermally decomposed at 90 {degree}?C with an enthalpy of -1924 J/g. The energics of the FHA thermal decomposition are comparable to those measured for aqueous solutions of hydroxylamine nitrate. Solid FHA should be stored in a location where the temperature does not exceed 20-25 {degree}?C. As a best practice, the solid material should be stored in a climate-controlled environment such as a refrigerator or freezer. FHA solutions in water are not susceptible to degradation by acid hydrolysis and are the preferred way to handle FHA prior to use.

  7. Studies of thin films and surfaces with optical harmonic generation and electron spectroscopy

    SciTech Connect (OSTI)

    Wilk, D.E.

    1996-01-01

    Optical second harmonic generation (SHG) and sum frequency generation (SFG) were used to study C{sup 60} thin solid films (low energy ED forbidden electronic excitations), and electron spectroscopy was used to study organic overlayers (xylenes) on Pt(111). Theory of SHG from a thin film is described in terms of surface and bulk contributions as well as local and nonlocal contributions to the optical nonlinearities. (1)In situ SHG data on C{sub 60} films during UHV film growth can be described in terms of only nonlocal contributions to both surface and bulk nonlinear susceptibilities. Microscopic origin of SHG response is discussed in terms of electric quadrupole and ED transitions of C{sub 60}. (2)Adsorption and thermal decomposition of ortho- and para-xylene on Pt(111) is studied using HREELS, LEED, AES, and thermal desorption spectroscopy. We have observed preferential decomposition of the methyl groups which leads to distinct decomposition pathways for ortho- and para-xylene on Pt(111).

  8. Molecular-Level Insights into the Reactivity of Siloxane-Based Electrolytes at a Lithium-Metal Anode

    SciTech Connect (OSTI)

    Assary, Rajeev S.; Lu, Jun; Luo, Xiangyi; Zhang, Xiaoyi; Ren, Yang; Wu, Huiming; Albishri, Hassan M.; El-Hady, D. A.; Al-Bogami, A. S.; Curtiss, Larry A.; Amine, Khalil

    2014-07-21

    A molecular-level understanding of the reactions that occur at the lithium-metal anode/electrolyte interphase is essential to improve the performance of LiO2 batteries. Experimental and computational techniques are applied to explore the reactivity of tri(ethylene glycol)-substituted trimethylsilane (1NM3), a siloxane-based ether electrolyte, at the lithium-metal anode. In situ/ex situ X-ray diffraction and Fourier-transform infrared spectroscopy studies provide evidence of the formation of lithium hydroxide and lithium carbonates at the anode upon gradual degradation of the metallic lithium anode and the solvent molecules in the presence of oxygen. Density functional calculations performed to obtain a mechanistic understanding of the reductive decomposition of 1NM3 indicate that the decomposition does not require any apparent barrier to produce lithium hydroxide and lithium carbonates when the reduced 1NM3 solvent molecules interact with the oxygen crossing over from the cathode. This study indicates that degradation may be more significant in the case of the 1NM3 solvent, compared to linear ethers such as tetraglyme or dioxalone, because of its relatively high electron affinity. Also, both protection of the lithium metal and prevention of oxygen crossover to the anode are essential for minimizing electrolyte and anode decomposition.

  9. Artificial Solid Electrolyte Interphase to Address the Electrochemical Degradation of Silicon Electrodes

    SciTech Connect (OSTI)

    Dudney, Nancy J; Nanda, Jagjit; Liang, Chengdu; Li, Juchuan

    2014-01-01

    Electrochemical degradation on Si anodes prevents them from being successfully used in lithium-ion full cells. Unlike the case of graphite anodes, natural solid electrolyte interphase (SEI) films generated from carbonate electrolyte do not self-passivate on Si and causes continuous electrolyte decomposition. In this work we aim at solving the issue of electrochemical degradation by fabricating artificial SEI films using a solid electrolyte material, lithium phosphor oxynitride (Lipon), that conducts Li ions and blocks electrons. For Si anodes coated with Lipon of 50 nm or thicker, significant effect is observed in suppressing the electrolyte decomposition, while Lipon of thinner than 40 nm has little effect. Ionic and electronic conductivity measurement reveals that the artificial SEI is effective when it is a pure ionic conductor, and the electrolyte decomposition is not suppressed when the artificial SEI is a mixed electronic-ionic conductor. The critical thickness for this transition in conducting behavior is found to be 40~50 nm. This work provides guidance for designing artificial SEI for high capacity lithium-ion battery electrodes using solid electrolyte materials.

  10. System for thermal energy storage, space heating and cooling and power conversion

    DOE Patents [OSTI]

    Gruen, Dieter M.; Fields, Paul R.

    1981-04-21

    An integrated system for storing thermal energy, for space heating and cong and for power conversion is described which utilizes the reversible thermal decomposition characteristics of two hydrides having different decomposition pressures at the same temperature for energy storage and space conditioning and the expansion of high-pressure hydrogen for power conversion. The system consists of a plurality of reaction vessels, at least one containing each of the different hydrides, three loops of circulating heat transfer fluid which can be selectively coupled to the vessels for supplying the heat of decomposition from any appropriate source of thermal energy from the outside ambient environment or from the spaces to be cooled and for removing the heat of reaction to the outside ambient environment or to the spaces to be heated, and a hydrogen loop for directing the flow of hydrogen gas between the vessels. When used for power conversion, at least two vessels contain the same hydride and the hydrogen loop contains an expansion engine. The system is particularly suitable for the utilization of thermal energy supplied by solar collectors and concentrators, but may be used with any source of heat, including a source of low-grade heat.

  11. Reactions catalyzed by haloporphyrins

    DOE Patents [OSTI]

    Ellis, Jr., Paul E.; Lyons, James E.

    1996-01-01

    The invention provides novel methods for the oxidation of hydrocarbons with oxygen-containing gas to form hydroxy-group containing compounds and for the decomposition of hydroperoxides to form hydroxygroup containing compounds. The catalysts used in the methods of the invention comprise transition metal complexes of a porphyrin ring having 1 to 12 halogen substituents on the porphyrin ring, at least one of said halogens being in a meso position and/or the catalyst containing no aryl group in a meso position. The catalyst compositions are prepared by halogenating a transition metal complex of a porphyrin. In one embodiment, a complex of a porphyrin with a metal whose porphyrin complexes are not active for oxidation of alkanes is halogenated, thereby to obtain a haloporphyrin complex of that metal, the metal is removed from the haloporphyrin complex to obtain the free base form of the haloporphyrin, and a metal such as iron whose porphyrin complexes are active for oxidation of alkanes and for the decomposition of alkyl hydroperoxides is complexed with the free base to obtain an active catalyst for oxidation of alkanes and decomposition of alkyl hydroperoxides.

  12. Haloporphyrins and their preparation and use as catalysts

    DOE Patents [OSTI]

    Ellis, P.E. Jr.; Lyons, J.E.

    1997-09-02

    The invention provides novel catalyst compositions, useful in the oxidation of hydrocarbons with air or oxygen to form hydroxy-group containing compounds and in the decomposition of hydroperoxides to form hydroxy-group containing compounds. The catalysts comprise transition metal complexes of a porphyrin ring having 1 to 12 halogen substituents on the porphyrin ring, at least one of said halogens being in a meso position and/or the catalyst containing no aryl group in a meso position. The compositions are prepared by halogenating a transition metal complex of a porphyrin. In one embodiment, a complex of a porphyrin with a metal whose porphyrin complexes are not active for oxidation of hydrocarbons is halogenated, thereby to obtain a haloporphyrin complex of that metal, the metal is removed from the haloporphyrin complex to obtain the free base form of the haloporphyrin, and a metal such as iron whose porphyrin complexes are active for oxidation of hydrocarbons and for the decomposition of alkyl hydroperoxides is complexed with the free base to obtain an active catalyst for oxidation of hydrocarbons and decomposition of alkyl hydroperoxides.

  13. Haloporphyrins and their preparation and use as catalysts

    DOE Patents [OSTI]

    Ellis, Jr., Paul E.; Lyons, James E.

    1997-01-01

    The invention provides novel catalyst compositions, useful in the oxidation of hydrocarbons with air or oxygen to form hydroxy-group containing compounds and in the decomposition of hydroperoxides to form hydroxy-group containing compounds. The catalysts comprise transition metal complexes of a porphyrin ring having 1 to 12 halogen substituents on the porphyrin ring, at least one of said halogens being in a meso position and/or the catalyst containing no aryl group in a meso position. The compositions are prepared by halogenating a transition metal complex of a porphyrin. In one embodiment, a complex of a porphyrin with a metal whose porphyrin complexes are not active for oxidation of hydrocarbons is halogenated, thereby to obtain a haloporphyrin complex of that metal, the metal is removed from the haloporphyrin complex to obtain the free base form of the haloporphyrin, and a metal such as iron whose porphyrin complexes are active for oxidation of hydrocarbons and for the decomposition of alkyl hydroperoxides is complexed with the free base to obtain an active catalyst for oxidation of hydrocarbons and decomposition of alkyl hydroperoxides.

  14. Reactions catalyzed by haloporphyrins

    DOE Patents [OSTI]

    Ellis, P.E. Jr.; Lyons, J.E.

    1996-02-06

    The invention provides novel methods for the oxidation of hydrocarbons with oxygen-containing gas to form hydroxy-group containing compounds and for the decomposition of hydroperoxides to form hydroxy-group containing compounds. The catalysts used in the methods of the invention comprise transition metal complexes of a porphyrin ring having 1 to 12 halogen substituents on the porphyrin ring, at least one of said halogens being in a meso position and/or the catalyst containing no aryl group in a meso position. The catalyst compositions are prepared by halogenating a transition metal complex of a porphyrin. In one embodiment, a complex of a porphyrin with a metal whose porphyrin complexes are not active for oxidation of alkanes is halogenated, thereby to obtain a haloporphyrin complex of that metal, the metal is removed from the haloporphyrin complex to obtain the free base form of the haloporphyrin, and a metal such as iron whose porphyrin complexes are active for oxidation of alkanes and for the decomposition of alkyl hydroperoxides is complexed with the free base to obtain an active catalyst for oxidation of alkanes and decomposition of alkyl hydroperoxides.

  15. Compatibility of Lithium Salts with Solvent of the Non-Aqueous Electrolyte in LiO2 Batteries

    SciTech Connect (OSTI)

    Du, Peng; Lu, Jun; Lau, Kah Chun; Luo, Xiangyi; Bareno, Javier; Zhang, Xiaoyi; Ren, Yang; Zhang, Zhengcheng; Curtiss, Larry A.; Sun, Yang-Kook; Amine, Khalil

    2013-02-20

    The stability of lithium salts, especially in the presence of reduced oxygen species, O2 and H2O (even in a small amount), plays an important role in the cyclability and capacity of LiO2 cells. This combined experimental and computational study provides evidence that the stability of the electrolyte used in LiO2 cells strongly depends on the compatibility of lithium salts with solvent. In the case of the LiPF61NM3 electrolyte, the decomposition of LiPF6 occurs in the cell as evidenced by in situ XRD, FT-IR and XPS analysis, which triggers the decomposition of 1NM3 solvent due to formation of HF from the decomposition of LiPF6. These reactions lead to degradation of the electrolyte and cause poor cyclability of the cell. The same reactions are not observed when LiTFSI and LiCF3SO3 are used as the lithium salts in 1NM3 solvent, or LiPF6 is used in TEGDME solvent.

  16. Permafrost carbonclimate feedback is sensitive to deep soil carbon decomposability but not deep soil nitrogen dynamics

    SciTech Connect (OSTI)

    Koven, Charles D.; Lawrence, David M.; Riley, William J.

    2015-03-09

    Permafrost soils contain enormous amounts of organic carbon whose stability is contingent on remaining frozen. With future warming, these soils may release carbon to the atmosphere and act as a positive feedback to climate change. Significant uncertainty remains on the postthaw carbon dynamics of permafrost-affected ecosystems, in particular since most of the carbon resides at depth where decomposition dynamics may differ from surface soils, and since nitrogen mineralized by decomposition may enhance plant growth. Here we show, using a carbonnitrogen model that includes permafrost processes forced in an unmitigated warming scenario, that the future carbon balance of the permafrost region is highly sensitive to the decomposability of deeper carbon, with the net balance ranging from 21 Pg C to 164 Pg C losses by 2300. Increased soil nitrogen mineralization reduces nutrient limitations, but the impact of deep nitrogen on the carbon budget is small due to enhanced nitrogen availability from warming surface soils and seasonal asynchrony between deeper nitrogen availability and plant nitrogen demands. The future carbon balance of this region is projected to hinge more on the rate and extent of permafrost thaw and soil decomposition than on enhanced nitrogen availability for vegetation growth resulting from permafrost thaw.

  17. High Cyclability of Ionic Liquid-Produced TiO2 Nanotube Arrays As an Anode Material for Lithium-Ion Batteries

    SciTech Connect (OSTI)

    Li, Huaqing; Martha, Surendra K; Unocic, Raymond R; Luo, Huimin; Dai, Sheng; Qu, Jun

    2012-01-01

    TiO{sub 2} nanotubes (NTs) are considered as a potential SEI-free anode material for Li-ion batteries to offer enhanced safety. Organic solutions, dominatingly ethylene glycol (EG)-based, have widely been used for synthesizing TiO{sub 2} NTs via anodization because of their ability to generate long tubes and well-aligned structures. However, it has been revealed that the EG-produced NTs are composited with carbonaceous decomposition products of EG, release of which during the tube crystallization process inevitably causes nano-scale porosity and cracks. These microstructural defects significantly deteriorate the NTs charge transport efficiency and mechanical strength/toughness. Here we report using ionic liquids (ILs) to anodize titanium to grow low-defect TiO{sub 2} NTs by reducing the electrolyte decomposition rate (less IR drop due to higher electrical conductivity) as well as the chance of the decomposition products mixing into the TiO{sub 2} matrix (organic cations repelled away). Promising electrochemical results have been achieved when using the IL-produced TiO{sub 2} NTs as an anode for Li-ion batteries. The ILNTs demonstrated excellent capacity retention without microstructural damage for nearly 1200 cycles of charge-discharge, while the NTs grown in a conventional EG solution totally pulverized in cycling, resulting in significant capacity fade.

  18. Parallel 3-D method of characteristics in MPACT

    SciTech Connect (OSTI)

    Kochunas, B.; Dovvnar, T. J.; Liu, Z.

    2013-07-01

    A new parallel 3-D MOC kernel has been developed and implemented in MPACT which makes use of the modular ray tracing technique to reduce computational requirements and to facilitate parallel decomposition. The parallel model makes use of both distributed and shared memory parallelism which are implemented with the MPI and OpenMP standards, respectively. The kernel is capable of parallel decomposition of problems in space, angle, and by characteristic rays up to 0(104) processors. Initial verification of the parallel 3-D MOC kernel was performed using the Takeda 3-D transport benchmark problems. The eigenvalues computed by MPACT are within the statistical uncertainty of the benchmark reference and agree well with the averages of other participants. The MPACT k{sub eff} differs from the benchmark results for rodded and un-rodded cases by 11 and -40 pcm, respectively. The calculations were performed for various numbers of processors and parallel decompositions up to 15625 processors; all producing the same result at convergence. The parallel efficiency of the worst case was 60%, while very good efficiency (>95%) was observed for cases using 500 processors. The overall run time for the 500 processor case was 231 seconds and 19 seconds for the case with 15625 processors. Ongoing work is focused on developing theoretical performance models and the implementation of acceleration techniques to minimize the number of iterations to converge. (authors)

  19. Differentiation of O-H and C-H Bond Scission Mechanisms of Ethylene Glycol on Pt and Ni/Pt Using Theory and Isotopic Labeling Experiments

    SciTech Connect (OSTI)

    Salciccioli, Michael [Univ. of Delaware, Newark, DE (United States). Catalysis Center for Energy Innovation (CCEI) and Center for Catalytic Science and Technology (CCST); Yu, Weiting [Univ. of Delaware, Newark, DE (United States). Catalysis Center for Energy Innovation (CCEI) and Center for Catalytic Science and Technology (CCST); Barteau, Mark A. [Univ. of Delaware, Newark, DE (United States). Catalysis Center for Energy Innovation (CCEI) and Center for Catalytic Science and Technology (CCST); Chen, Jingguang G. [Univ. of Delaware, Newark, DE (United States). Catalysis Center for Energy Innovation (CCEI) and Center for Catalytic Science and Technology (CCST); Vlachos, Dionisios G. [Univ. of Delaware, Newark, DE (United States). Catalysis Center for Energy Innovation (CCEI) and Center for Catalytic Science and Technology (CCST)

    2011-05-25

    Understanding and controlling bond-breaking sequences of oxygenates on transition metal catalysts can greatly impact the utilization of biomass feedstocks for fuels and chemicals. The decomposition of ethylene glycol, as the simplest representative of biomass-derived polyols, was studied via density functional theory (DFT) calculations to identify the differences in reaction pathways between Pt and the more active Ni/Pt bimetallic catalyst. Comparison of the computed transition states indicated three potentially feasible paths from ethylene glycol to C1 oxygenated adsorbates on Pt. While not important on Pt, the pathway to 1,2-dioxyethylene (OCH?CH?O) is favored energetically on the Ni/Pt catalyst. Temperature-programmed desorption (TPD) experiments were conducted with deuterated ethylene glycols for comparison with DFT results. These experiments confirmed that decomposition of ethylene glycol on Pt proceeds via initial OH bond cleavage, followed by CH and the second OH bond cleavages, whereas on the Ni/Pt surface, both OH bonds are cleaved initially. The results are consistent with vibrational spectra and indicate that tuning of the catalyst surface can selectively control bond breaking. Finally, the significant mechanistic differences in decomposition of polyols compared to that of monoalcohols and hydrocarbons serve to identify general trends in bond scission sequences.

  20. Theoretical investigation of HNgNH{sub 3}{sup +} ions (Ng = He, Ne, Ar, Kr, and Xe)

    SciTech Connect (OSTI)

    Gao, Kunqi; Sheng, Li

    2015-04-14

    The equilibrium geometries, harmonic frequencies, and dissociation energies of HNgNH{sub 3}{sup +} ions (Ng = He, Ne, Ar, Kr, and Xe) were investigated using the following method: Becke-3-parameter-Lee-Yang-Parr (B3LYP), Boese-Matrin for Kinetics (BMK), second-order Mller-Plesset perturbation theory (MP2), and coupled-cluster with single and double excitations as well as perturbative inclusion of triples (CCSD(T)). The results indicate that HHeNH{sub 3}{sup +}, HArNH{sub 3}{sup +}, HKrNH{sub 3}{sup +}, and HXeNH{sub 3}{sup +} ions are metastable species that are protected from decomposition by high energy barriers, whereas the HNeNH{sub 3}{sup +} ion is unstable because of its relatively small energy barrier for decomposition. The bonding nature of noble-gas atoms in HNgNH{sub 3}{sup +} was also analyzed using the atoms in molecules approach, natural energy decomposition analysis, and natural bond orbital analysis.

  1. Permafrost carbon—climate feedback is sensitive to deep soil carbon decomposability but not deep soil nitrogen dynamics

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

    Koven, Charles D.; Lawrence, David M.; Riley, William J.

    2015-03-09

    Permafrost soils contain enormous amounts of organic carbon whose stability is contingent on remaining frozen. With future warming, these soils may release carbon to the atmosphere and act as a positive feedback to climate change. Significant uncertainty remains on the postthaw carbon dynamics of permafrost-affected ecosystems, in particular since most of the carbon resides at depth where decomposition dynamics may differ from surface soils, and since nitrogen mineralized by decomposition may enhance plant growth. Here we show, using a carbon–nitrogen model that includes permafrost processes forced in an unmitigated warming scenario, that the future carbon balance of the permafrost regionmore » is highly sensitive to the decomposability of deeper carbon, with the net balance ranging from 21 Pg C to 164 Pg C losses by 2300. Increased soil nitrogen mineralization reduces nutrient limitations, but the impact of deep nitrogen on the carbon budget is small due to enhanced nitrogen availability from warming surface soils and seasonal asynchrony between deeper nitrogen availability and plant nitrogen demands. The future carbon balance of this region is projected to hinge more on the rate and extent of permafrost thaw and soil decomposition than on enhanced nitrogen availability for vegetation growth resulting from permafrost thaw.« less

  2. ?-Fe{sub 2}O{sub 3} nanoparticles: An easily recoverable effective photo-catalyst for the degradation of rose bengal and methylene blue dyes in the waste-water treatment plant

    SciTech Connect (OSTI)

    Dutta, Amit Kumar; Maji, Swarup Kumar; Adhikary, Bibhutosh

    2014-01-01

    Graphical abstract: - Highlights: ?-Fe{sub 2}O{sub 3} NPs from a single-source precursor and characterized by XRD, TEM, UVvis spectra. The NPs were tested as effective photocatalyst toward degradation of RB and MB dyes. The possible pathway of the photocatalytic decomposition process has been discussed. The active species, OH, was detected by TA photoluminescence probing techniques. - Abstract: ?-Fe{sub 2}O{sub 3} nanoparticles (NPs) were synthesized from a single-source precursor complex [Fe{sub 3}O(C{sub 6}H{sub 5}COO){sub 6}(H{sub 2}O){sub 3}]NO{sub 3} by a simple thermal decomposition process and have been characterized by X-ray diffraction analysis (XRD), transmission electron microscopy (TEM) and UVvis spectroscopic techniques. The NPs were highly pure and well crystallized having hexagonal morphology with an average particle size of 35 nm. The prepared ?-Fe{sub 2}O{sub 3} (maghemite) NPs show effective photo-catalytic activity toward the degradation of rose bengal (RB) and methylene blue (MB) dyes under visible light irradiation and can easily be recoverable in the presence of magnetic field for successive re-uses. The possible photo-catalytic decomposition mechanism is discussed through the detection of hydroxyl radical (OH) by terephthalic acid photo-luminescence probing technique.

  3. Integrated Technology Air Cleaners (ITAC): Design and Evaluation

    SciTech Connect (OSTI)

    Fisk, William J.; Cohn, Sebastian; Destaillats, Hugo; Henzel, Victor; Sidheswaran, Meera; Sullivan, Douglas P.

    2013-09-13

    The primary objective of this project was to design, build, and test an air cleaner for residential use with the potential to substantially improve indoor air quality, or maintain indoor air quality unchanged, when outdoor air ventilation rates are reduced to save energy. Two air cleaners were designed and fabricated. The design targets for airflow rate, fan power, and projected cost were met. In short term laboratory studies, both units performed as expected; however, during field studies in homes, the formaldehyde removal performance of the air cleaners was much lower than expected. In subsequent laboratory studies, incomplete decomposition of some indoor air volatile organic compounds, with formaldehyde as a product of partial decomposition of volatile organic compounds, was confirmed as the explanation for the poor formaldehyde removal performance in the field studies. The amount of formaldehyde produced per unit of decomposition of other volatile organic compounds was substantially diminished by increasing the amount of catalyst on the filter and also by decreasing the air velocity. Together, these two measures reduced formaldehyde production, per unit destruction of other volatile organic compounds, by a factor of four, while increasing the removal efficiency of volatile organic compounds by a factor of 1.4. A company with a southern California office is conducting studies in conjunction with Lawrence Berkeley National Laboratory, with the goal of incorporating the ITAC catalytic air cleaning technology in their future commercial products.

  4. First report on non-thermal plasma reactor scaling criteria and optimization models

    SciTech Connect (OSTI)

    Rosocha, L.A.; Korzekwa, R.A.

    1998-01-13

    The purpose of SERDP project CP-1038 is to evaluate and develop non-thermal plasma (NTP) reactor technology for Department of Defense (DoD) air emissions control applications. The primary focus is on oxides of nitrogen (NO{sub x}) and a secondary focus on hazardous air pollutants (HAPs), especially volatile organic compounds (VOCs). Example NO{sub x} sources are jet engine test cells (JETCs) and diesel engine powered electrical generators. Example VOCs are organic solvents used in painting, paint stripping, and parts cleaning. To design and build NTP reactors that are optimized for particular DoD applications, one must understand the basic decomposition chemistry of the target compound(s) and how the decomposition of a particular chemical species depends on the air emissions stream parameters and the reactor operating parameters. This report is intended to serve as an overview of the subject of reactor scaling and optimization and will discuss the basic decomposition chemistry of nitric oxide (NO) and two representative VOCs, trichloroethylene and carbon tetrachloride, and the connection between the basic plasma chemistry, the target species properties, and the reactor operating parameters (in particular, the operating plasma energy density). System architecture, that is how NTP reactors can be combined or ganged to achieve higher capacity, will also be briefly discussed.

  5. Efficacy of fixed filtration for rapid kVp-switching dual energy x-ray systems

    SciTech Connect (OSTI)

    Yao, Yuan; Wang, Adam S.; Pelc, Norbert J.; Department of Radiology, Stanford University, Stanford, California 94305; Department of Electrical Engineering, Stanford University, Stanford, California 94305

    2014-03-15

    Purpose: Dose efficiency of dual kVp imaging can be improved if the two beams are filtered to remove photons in the common part of their spectra, thereby increasing spectral separation. While there are a number of advantages to rapid kVp-switching for dual energy, it may not be feasible to have two different filters for the two spectra. Therefore, the authors are interested in whether a fixed added filter can improve the dose efficiency of kVp-switching dual energy x-ray systems. Methods: The authors hypothesized that a K-edge filter would provide the energy selectivity needed to remove overlap of the spectra and hence increase the precision of material separation at constant dose. Preliminary simulations were done using calcium and water basis materials and 80 and 140 kVp x-ray spectra. Precision of the decomposition was evaluated based on the propagation of the Poisson noise through the decomposition function. Considering availability and cost, the authors chose a commercial Gd{sub 2}O{sub 2}S screen as the filter for their experimental validation. Experiments were conducted on a table-top system using a phantom with various thicknesses of acrylic and copper and 70 and 125 kVp x-ray spectra. The authors kept the phantom exposure roughly constant with and without filtration by adjusting the tube current. The filtered and unfiltered raw data of both low and high energy were decomposed into basis material and the variance of the decomposition for each thickness pair was calculated. To evaluate the filtration performance, the authors measured the ratio of material decomposition variance with and without filtration. Results: Simulation results show that the ideal filter material depends on the object composition and thickness, and ranges across the lanthanide series, with higher atomic number filters being preferred for more attenuating objects. Variance reduction increases with filter thickness, and substantial reductions (40%) can be achieved with a 2 loss in intensity. The authors experimental results validate the simulations, yet were overall slightly worse than expectation. For large objects, conventional (non-K-edge) beam hardening filters perform well. Conclusions: This study demonstrates the potential of fixed K-edge filtration to improve the dose efficiency and material decomposition precision for rapid kVp-switching dual energy systems.

  6. Selective NOx Recirculation for Stationary Lean-Burn Natural Gas Engines

    SciTech Connect (OSTI)

    Nigel Clark; Gregory Thompson; Richard Atkinson; Richard Turton; Chamila Tissera; Emre Tatli; Andy Zimmerman

    2005-12-28

    Selective NOx Recirculation (SNR) involves cooling the engine exhaust gas and then adsorbing the oxides of nitrogen (NOx) from the exhaust stream, followed by the periodic desorption of NOx. By returning the desorbed, concentrated NOx into the engine intake and through the combustion chamber, a percentage of the NOx is decomposed during the combustion process. An initial study of NOx decomposition during lean-burn combustion was concluded in 2004 using a 1993 Cummins L10G 240hp natural gas engine. It was observed that the air/fuel ratio, injected NO (nitric oxide) quantity and engine operating points affected NOx decomposition rates of the engine. Chemical kinetic modeling results were also used to determine optimum NOx decomposition operating points and were published in the 2004 annual report. A NOx decomposition rate of 27% was measured from this engine under lean-burn conditions while the software model predicted between 35-42% NOx decomposition for similar conditions. A later technology 1998 Cummins L10G 280hp natural gas engine was procured with the assistance of Cummins Inc. to replace the previous engine used for 2005 experimental research. The new engine was equipped with an electronic fuel management system with closed-loop control that provided a more stable air/fuel ratio control and improved the repeatability of the tests. The engine was instrumented with an in-cylinder pressure measurement system and electronic controls, and was adapted to operate over a range of air/fuel ratios. The engine was connected to a newly commissioned 300hp alternating current (AC) motoring dynamometer. The second experimental campaign was performed to acquire both stoichiometric and slightly rich (0.97 lambda ratio) burn NOx decomposition rates. Effects of engine load and speed on decomposition were quantified, but Exhaust Gas Recirculation (EGR) was not varied independently. Decomposition rates of up to 92% were demonstrated. Following recommendations at the 2004 ARES peer review meeting at Argonne National Laboratories, in-cylinder pressure was measured to calculate engine indicated mean effective pressure (IMEP) changes due to NOx injections and EGR variations, and to observe conditions in the cylinder. The third experimental campaign gathered NOx decomposition data at 800, 1200 and 1800 rpm. EGR was added via an external loop, with EGR ranging from zero to the point of misfire. The air/fuel ratio was set at both stoichiometric and slightly rich conditions, and NOx decomposition rates were calculated for each set of runs. Modifications were made to the engine exhaust manifold to record individual exhaust temperatures. The three experimental campaigns have provided the data needed for a comprehensive model of NOx decomposition during the combustion process, and data have confirmed that there was no significant impact of injected NO on in-cylinder pressure. The NOx adsorption system provided by Sorbent Technologies Corp. (Twinsburg, OH), comprised a NOx adsorber, heat exchanger and a demister. These components were connected to the engine, and data were gathered to show both the adsorption of NOx from the engine, and desorption of NOx from the carbon-based sorbent material back into the engine intake, using a heated air stream. In order to quantify the NOx adsorption/desorption characteristics of the sorbent material, a bench top adsorption system was constructed and instrumented with thermocouples and the system output was fed into a NOx analyzer. The temperature of this apparatus was controlled while gathering data on the characteristics of the sorbent material. These data were required for development of a system model. Preliminary data were gathered in 2005, and will continue in early 2006. To assess the economic benefits of the proposed SNR technology the WVU research team has been joined in the last quarter by Dr Richard Turton (WVU-Chemical Engineering), who is modeling, sizing and costing the major components. The tasks will address modeling and preliminary design of the heat exchanger, demister and NOx sorbent chamber s

  7. Selective NOx Recirculation for Stationary Lean-Burn Natural Gas Engines

    SciTech Connect (OSTI)

    Nigel N. Clark

    2006-12-31

    Nitric oxide (NO) and nitrogen dioxide (NO2) generated by internal combustion (IC) engines are implicated in adverse environmental and health effects. Even though lean-burn natural gas engines have traditionally emitted lower oxides of nitrogen (NOx) emissions compared to their diesel counterparts, natural gas engines are being further challenged to reduce NOx emissions to 0.1 g/bhp-hr. The Selective NOx Recirculation (SNR) approach for NOx reduction involves cooling the engine exhaust gas and then adsorbing the NOx from the exhaust stream, followed by the periodic desorption of NOx. By sending the desorbed NOx back into the intake and through the engine, a percentage of the NOx can be decomposed during the combustion process. SNR technology has the support of the Department of Energy (DOE), under the Advanced Reciprocating Engine Systems (ARES) program to reduce NOx emissions to under 0.1 g/bhp-hr from stationary natural gas engines by 2010. The NO decomposition phenomenon was studied using two Cummins L10G natural gas fueled spark-ignited (SI) engines in three experimental campaigns. It was observed that the air/fuel ratio ({lambda}), injected NO quantity, added exhaust gas recirculation (EGR) percentage, and engine operating points affected NOx decomposition rates within the engine. Chemical kinetic model predictions using the software package CHEMKIN were performed to relate the experimental data with established rate and equilibrium models. The model was used to predict NO decomposition during lean-burn, stoichiometric burn, and slightly rich-burn cases with added EGR. NOx decomposition rates were estimated from the model to be from 35 to 42% for the lean-burn cases and from 50 to 70% for the rich-burn cases. The modeling results provided an insight as to how to maximize NOx decomposition rates for the experimental engine. Results from this experiment along with chemical kinetic modeling solutions prompted the investigation of rich-burn operating conditions, with added EGR to prevent preignition. It was observed that the relative air/fuel ratio, injected NO quantity, added EGR fraction, and engine operating points affected the NO decomposition rates. While operating under these modified conditions, the highest NO decomposition rate of 92% was observed. In-cylinder pressure data gathered during the experiments showed minimum deviation from peak pressure as a result of NO injections into the engine. A NOx adsorption system, from Sorbent Technologies, Inc., was integrated with the Cummins engine, comprised a NOx adsorbent chamber, heat exchanger, demister, and a hot air blower. Data were gathered to show the possibility of NOx adsorption from the engine exhaust, and desorption of NOx from the sorbent material. In order to quantify the NOx adsorption/desorption characteristics of the sorbent material, a benchtop adsorption system was constructed. The temperature of this apparatus was controlled while data were gathered on the characteristics of the sorbent material for development of a system model. A simplified linear driving force model was developed to predict NOx adsorption into the sorbent material as cooled exhaust passed over fresh sorbent material. A mass heat transfer analysis was conducted to analyze the possibility of using hot exhaust gas for the desorption process. It was found in the adsorption studies, and through literature review, that NO adsorption was poor when the carrier gas was nitrogen, but that NO in the presence of oxygen was adsorbed at levels exceeding 1% by mass of the sorbent. From the three experimental campaigns, chemical kinetic modeling analysis, and the scaled benchtop NOx adsorption system, an overall SNR system model was developed. An economic analysis was completed, and showed that the system was impractical in cost for small engines, but that economies of scale favored the technology.

  8. Flow distribution analysis on the cooling tube network of ITER thermal shield

    SciTech Connect (OSTI)

    Nam, Kwanwoo; Chung, Wooho; Noh, Chang Hyun; Kang, Dong Kwon; Kang, Kyoung-O; Ahn, Hee Jae; Lee, Hyeon Gon

    2014-01-29

    Thermal shield (TS) is to be installed between the vacuum vessel or the cryostat and the magnets in ITER tokamak to reduce the thermal radiation load to the magnets operating at 4.2K. The TS is cooled by pressurized helium gas at the inlet temperature of 80K. The cooling tube is welded on the TS panel surface and the composed flow network of the TS cooling tubes is complex. The flow rate in each panel should be matched to the thermal design value for effective radiation shielding. This paper presents one dimensional analysis on the flow distribution of cooling tube network for the ITER TS. The hydraulic cooling tube network is modeled by an electrical analogy. Only the cooling tube on the TS surface and its connecting pipe from the manifold are considered in the analysis model. Considering the frictional factor and the local loss in the cooling tube, the hydraulic resistance is expressed as a linear function with respect to mass flow rate. Sub-circuits in the TS are analyzed separately because each circuit is controlled by its own control valve independently. It is found that flow rates in some panels are insufficient compared with the design values. In order to improve the flow distribution, two kinds of design modifications are proposed. The first one is to connect the tubes of the adjacent panels. This will increase the resistance of the tube on the panel where the flow rate is excessive. The other design suggestion is that an orifice is installed at the exit of tube routing where the flow rate is to be reduced. The analysis for the design suggestions shows that the flow mal-distribution is improved significantly.

  9. Petascale Parallelization of the Gyrokinetic Toroidal Code

    SciTech Connect (OSTI)

    Ethier, Stephane; Adams, Mark; Carter, Jonathan; Oliker, Leonid

    2010-05-01

    The Gyrokinetic Toroidal Code (GTC) is a global, three-dimensional particle-in-cell application developed to study microturbulence in tokamak fusion devices. The global capability of GTC is unique, allowing researchers to systematically analyze important dynamics such as turbulence spreading. In this work we examine a new radial domain decomposition approach to allow scalability onto the latest generation of petascale systems. Extensive performance evaluation is conducted on three high performance computing systems: the IBM BG/P, the Cray XT4, and an Intel Xeon Cluster. Overall results show that the radial decomposition approach dramatically increases scalability, while reducing the memory footprint - allowing for fusion device simulations at an unprecedented scale. After a decade where high-end computing (HEC) was dominated by the rapid pace of improvements to processor frequencies, the performance of next-generation supercomputers is increasingly differentiated by varying interconnect designs and levels of integration. Understanding the tradeoffs of these system designs is a key step towards making effective petascale computing a reality. In this work, we examine a new parallelization scheme for the Gyrokinetic Toroidal Code (GTC) [?] micro-turbulence fusion application. Extensive scalability results and analysis are presented on three HEC systems: the IBM BlueGene/P (BG/P) at Argonne National Laboratory, the Cray XT4 at Lawrence Berkeley National Laboratory, and an Intel Xeon cluster at Lawrence Livermore National Laboratory. Overall results indicate that the new radial decomposition approach successfully attains unprecedented scalability to 131,072 BG/P cores by overcoming the memory limitations of the previous approach. The new version is well suited to utilize emerging petascale resources to access new regimes of physical phenomena.

  10. Behavior of carbonate-rich fuels in ACFBC and PFBC conditions

    SciTech Connect (OSTI)

    Ots, A.; Arro, H.; Pihu, T.; Prikk, A.

    1999-07-01

    Estonian oil shale is known as one of richest in carbonate fuels. High mineral matter content (60--75% in dry mass), moderate moisture (9--12%) and carbonate carbon dioxide content (17--19%), and low heating value (LHV 8--10 MJ/kg as received) are characteristic for Estonian oil shale. Approximately half of the mineral matter is in the carbonate form, mainly as calcium carbonate. The sulfur content of dry mass is 1.5--1.7% and Ca/S molar ratio is 8--10. Due to limestone present in oil shale, the additional sorbent for sulfur retention during combustion is not needed. The behavior of carbonates as well as the formation of ash at fluidized bed combustion (FBC) was the main topics to study. At Thermal Engineering Department (TED) of Tallinn Technical University a laboratory pressurized combustion facility was used for investigation the decomposition of soil shale carbonates in atmospheric and pressurized burning conditions. The experiments with oil shale were performed at pressures 0.1 MPa and 1.2 MPa and at the temperature 850 C. Based on the carbonate decomposition rate (CDR) 0.3--0.4 established experimentally at pressurized combustion, it may be concluded that the heating value of oil shale increases approximately by 5.5--8% and the carbon dioxide concentration in flue gas decreases by 13--20% compared with the conditions of the complete decomposition of carbonate. Combustion of oil shale was tested in 0.15--1.0 MW{sub th} test facilities. The tests confirmed the suitability of both ACFBC and PFBC technologies to utilize oil shale. The tests showed a nearly complete binding of sulfur by oil shale ash and a limited formation of NO{sub x} at combustion. Oil shale FBC is characterized by the formation of large amounts (40--85% from total) of fine-grained fly ash.

  11. Old and stable soil organic matter is not necessarily chemically recalcitrant: Implications for modeling concepts and temperature sensitivity

    SciTech Connect (OSTI)

    Kleber, M.; Nico, P.S.; Plante, A.; Filley, T.; Kramer, M.; Swanston, C.; Sollins, P.

    2010-03-01

    Soil carbon turnover models generally divide soil carbon into pools with varying intrinsic decomposition rates. Although these decomposition rates are modified by factors such as temperature, texture, and moisture, they are rationalized by assuming chemical structure is a primary controller of decomposition. In the current work, we use near edge X-ray absorption fine structure (NEXAFS) spectroscopy in combination with differential scanning calorimetry (DSC) and alkaline cupric oxide (CuO) oxidation to explore this assumption. Specifically, we examined material from the 2.3-2.6 kg L{sup -1} density fraction of three soils of different type (Oxisol, Alfisol, Inceptisol). The density fraction with the youngest {sup 14}C age (Oxisol, 107 years) showed the highest relative abundance of aromatic groups and the lowest O-alkyl C/aromatic C ratio as determined by NEXAFS. Conversely, the fraction with the oldest C (Inceptisol, 680 years) had the lowest relative abundance of aromatic groups and highest O-alkyl C/aromatic C ratio. This sample also had the highest proportion of thermally labile materials as measured by DSC, and the highest ratio of substituted fatty acids to lignin phenols as indicated by CuO oxidation. Therefore, the organic matter of the Inceptisol sample, with a {sup 14}C age associated with 'passive' pools of carbon (680 years), had the largest proportion of easily metabolizable organic molecules with low thermodynamic stability, whereas the organic matter of the much younger Oxisol sample (107 years) had the highest proportion of supposedly stable organic structures considered more difficult to metabolize. Our results demonstrate that C age is not necessarily related to molecular structure or thermodynamic stability, and we suggest that soil carbon models would benefit from viewing turnover rate as codetermined by the interaction between substrates, microbial actors, and abiotic driving variables. Furthermore, assuming that old carbon is composed of complex or 'recalcitrant' compounds will erroneously attribute a greater temperature sensitivity to those materials than they may actually possess.

  12. Syntheses and characterization of energetic compounds constructed from alkaline earth metal cations (Sr and Ba) and 1,2-bis(tetrazol-5-yl)ethane

    SciTech Connect (OSTI)

    Xia Zhengqiang; Chen Sanping; Wei Qing; Qiao Chengfang

    2011-07-15

    Two new energetic compounds, [M(BTE)(H{sub 2}O){sub 5}]{sub n} (M=Sr(1), Ba(2)) [H{sub 2}BTE=1,2-bis(tetrazol-5-yl)ethane], have been hydrothermally synthesized and structurally characterized. Single-crystal X-ray diffraction analyses reveal that they are isomorphous and exhibit 2D (4,4) net framework, generated by 4-connected Sr{sub 2}(H{sub 2}O){sub 10}/Ba{sub 2}(H{sub 2}O){sub 10} SBUs linked up by two independent binding modes of H{sub 2}BTE, and the resulting 2D structure is interconnected by hydrogen-bond and strong face to face {pi}-{pi} stacking interactions between two tetrazole rings to lead to a 3D supramolecular architecture. DSC measurements show that they have significant catalytic effects on thermal decomposition of ammonium perchlorate. Moreover, the photoluminescence properties, thermogravimetric analyses, and flame colors of the as-prepared compounds are also investigated in this paper. - Graphical abstract: Two novel 2D isomorphous alkaline earth metal complexes were assembled by 4-connected Sr{sub 2}(H{sub 2}O){sub 10}/Ba{sub 2}(H{sub 2}O){sub 10} SBUs and two independent binding modes of H{sub 2}BTE ligands, and the catalytic performances toward thermal decomposition of ammonium perchlorate and photoluminescent properties of them were investigated. Highlights: > Two novel alkaline earth energetic coordination polymers have been prepared.{yields} Both structures are layered based on 4-connected Sr{sub 2}(H{sub 2}O){sub 10}/Ba{sub 2}(H{sub 2}O){sub 10} SBUs and two distinct H{sub 2}BTE coordination modes.{yields} The dehydrated products of the compounds possess good thermostability and significant catalytic effects on thermal decomposition of AP.

  13. Large scale synthesis of nanostructured zirconia-based compounds from freeze-dried precursors

    SciTech Connect (OSTI)

    Gomez, A.; Villanueva, R.; Vie, D.; Murcia-Mascaros, S.; Martinez, E.; Beltran, A.; Sapina, F.; Vicent, M.; Sanchez, E.

    2013-01-15

    Nanocrystalline zirconia powders have been obtained at the multigram scale by thermal decomposition of precursors resulting from the freeze-drying of aqueous acetic solutions. This technique has equally made possible to synthesize a variety of nanostructured yttria or scandia doped zirconia compositions. SEM images, as well as the analysis of the XRD patterns, show the nanoparticulated character of those solids obtained at low temperature, with typical particle size in the 10-15 nm range when prepared at 673 K. The presence of the monoclinic, the tetragonal or both phases depends on the temperature of the thermal treatment, the doping concentration and the nature of the dopant. In addition, Rietveld refinement of the XRD profiles of selected samples allows detecting the coexistence of the tetragonal and the cubic phases for high doping concentration and high thermal treatment temperatures. Raman experiments suggest the presence of both phases also at relatively low treatment temperatures. - Graphical abstract: Zr{sub 1-x}A{sub x}O{sub 2-x/2} (A=Y, Sc; 0{<=}x{<=}0.12) solid solutions have been prepared as nanostructured powders by thermal decomposition of precursors obtained by freeze-drying, and this synthetic procedure has been scaled up to the 100 g scale. Highlights: Black-Right-Pointing-Pointer Zr{sub 1-x}A{sub x}O{sub 2-x/2} (A=Y, Sc; 0{<=}x{<=}0.12) solid solutions have been prepared as nanostructured powders. Black-Right-Pointing-Pointer The synthetic method involves the thermal decomposition of precursors obtained by freeze-drying. Black-Right-Pointing-Pointer The temperature of the thermal treatment controls particle sizes. Black-Right-Pointing-Pointer The preparation procedure has been scaled up to the 100 g scale. Black-Right-Pointing-Pointer This method is appropriate for the large-scale industrial preparation of multimetallic systems.

  14. X-rays structural analysis and thermal stability studies of the ternary compound {alpha}-AlFeSi

    SciTech Connect (OSTI)

    Roger, J.; Bosselet, F.; Viala, J.C.

    2011-05-15

    From literature data presently available, the decomposition temperature and the nature of the decomposition reaction of the ternary compound {alpha}-AlFeSi (also designated as {alpha}{sub H} or {tau}{sub 5}) are not clearly identified. Moreover, some uncertainties remain concerning its crystal structure. The crystallographic structure and thermochemical behaviour of the ternary compound {alpha}-AlFeSi were meticulously studied. The crystal structure of {alpha}-AlFeSi was examined at room temperature from X-ray single crystal intensity data. It presents hexagonal symmetry, space group P6{sub 3}/mmc with unit cell parameters (293 K) a=12.345(2) A and c=26.210(3) A (V=3459 A{sup 3}). The average chemical formula obtained from refinement is Al{sub 7.1}Fe{sub 2}Si. From isothermal reaction-diffusion experiments and Differential Thermal Analysis, the title compound decomposes peritectically upon heating into {theta}-Fe{sub 4}Al{sub 13}(Si), {gamma}-Al{sub 3}FeSi and a ternary Al-rich liquid. Under atmospheric pressure, the temperature of this reversible transformation has been determined to be 772{+-}12 {sup o}C. -- Graphical abstract: Partial representation of the crystal structure of the {alpha}-Al{sub 7.1}Fe{sub 2}Si compound. Display Omitted Highlights: The main findings of our work are: {yields} a detailed X-rays crystal structure determination of the ternary compound {alpha}-AlFeSi. {yields} The precision of the silicon atoms positions in the crystal structure. {yields} A precised determination of the decomposition temperature of this compound.

  15. Transition from cool flame to thermal flame in compression ignition process

    SciTech Connect (OSTI)

    Yamada, Hiroyuki; Suzaki, Kotaro; Goto, Yuichi; Tezaki, Atsumu

    2008-07-15

    The mechanism that initiates thermal flames in compression ignition has been studied. Experimentally, a homogeneous charge compression ignition (HCCI) engine was used with DME, n-heptane, and n-decane. Arrhenius plots of the heat release rate in the HCCI experiments showed that rates of heat release with DME, n-heptane, and n-decane exhibited a certain activation energy that is identical to that of the H{sub 2}O{sub 2} decomposition reaction. The same feature was observed in diesel engine operation using ordinary diesel fuel with advanced ignition timing to make ignition occur after the end of fuel injection. These experimental results were reproduced in nondimensional simulations using kinetic mechanisms for DME, n-heptane, and n-decane, the last being developed by extending the n-heptane mechanism. Methanol addition, which suppresses low-temperature oxidation (LTO) and delays the ignition timing, had no effect on the activation energy obtained from the Arrhenius plot of heat release rate. Nevertheless, methanol addition lowered the heat release rates during the prethermal flame process. This is because H{sub 2}O{sub 2} formation during cool flame was reduced by adding methanol. The mechanism during the transition process from cool flame to thermal flame can be explained quantitatively using thermal explosion theory, in which the rate-determining reaction is H{sub 2}O{sub 2} decomposition, assuming that heat release in this period is caused by partial oxidation of DME and HCHO initiated with the reaction with OH produced though H{sub 2}O{sub 2} decomposition. (author)

  16. Metathesis depolymerizable surfactants

    DOE Patents [OSTI]

    Jamison, Gregory M. (Albuquerque, NM); Wheeler, David R. (Albuquerque, NM); Loy, Douglas A. (Tucson, AZ); Simmons, Blake A. (San Francisco, CA); Long, Timothy M. (Evanston, IL); McElhanon, James R. (Manteca, CA); Rahimian, Kamyar (Albuquerque, NM); Staiger, Chad L. (Albuquerque, NM)

    2008-04-15

    A class of surfactant molecules whose structure includes regularly spaced unsaturation in the tail group and thus, can be readily decomposed by ring-closing metathesis, and particularly by the action of a transition metal catalyst, to form small molecule products. These small molecules are designed to have increased volatility and/or enhanced solubility as compared to the original surfactant molecule and are thus easily removed by solvent extraction or vacuum extraction at low temperature. By producing easily removable decomposition products, the surfactant molecules become particularly desirable as template structures for preparing meso- and microstructural materials with tailored properties.

  17. Two photon spectroscopy of UF6 in the near ultraviolet

    SciTech Connect (OSTI)

    Bernstein, E.R.; Kennedy, P.M.

    1981-03-01

    The two photon excited fluorescence excitation spectrum of UF6 was observed in the region 410 to 315 nm. The spectrum was virtually indistinguishable from the one photon absorption in this region. No vibronic structure was observed in absorption or dispersed emission. These data indicate a high density of u and g states for UF6 in this energy range and facile photochemical decomposition. Emission intensity was found to be proportional to laser power to the 3.0 to 3.6 power.

  18. Designer synthetic media for studying microbial-catalyzed biofuel production

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

    Tang, Xiaoyu; da Costa Sousa, Leonardo; Jin, Mingjie; Chundawat, Shishir; Chambliss, Charles; Lau, Ming W; Xiao, Zeyi; Dale, Bruce E; Balan, Venkatesh

    2015-01-01

    Background: The fermentation inhibition of yeast or bacteria by lignocellulose-derived degradation products, during hexose/pentose co-fermentation, is a major bottleneck for cost-effective lignocellulosic biorefineries. To engineer microbial strains for improved performance, it is critical to understand the mechanisms of inhibition that affect fermentative organisms in the presence of major components of a lignocellulosic hydrolysate. The development of a synthetic lignocellulosic hydrolysate (SH) media with a composition similar to the actual biomass hydrolysate will be an important advancement to facilitate these studies. In this work, we characterized the nutrients and plant-derived decomposition products present in AFEX™ pretreated corn stover hydrolysate (ACH). Themore » SH was formulated based on the ACH composition and was further used to evaluate the inhibitory effects of various families of decomposition products during Saccharomyces cerevisiae 424A (LNH-ST) fermentation. Results: The ACH contained high levels of nitrogenous compounds, notably amides, pyrazines, and imidazoles. In contrast, a relatively low content of furans and aromatic and aliphatic acids were found in the ACH. Though most of the families of decomposition products were inhibitory to xylose fermentation, due to their abundance, the nitrogenous compounds showed the most inhibition. From these compounds, amides (products of the ammonolysis reaction) contributed the most to the reduction of the fermentation performance. However, this result is associated to a concentration effect, as the corresponding carboxylic acids (products of hydrolysis) promoted greater inhibition when present at the same molar concentration as the amides. Due to its complexity, the formulated SH did not perfectly match the fermentation profile of the actual hydrolysate, especially the growth curve. However, the SH formulation was effective for studying the inhibitory effect of various compounds on yeast fermentation. Conclusions: The formulation of SHs is an important advancement for future multi-omics studies and for better understanding the mechanisms of fermentation inhibition in lignocellulosic hydrolysates. The SH formulated in this work was instrumental for defining the most important inhibitors in the ACH. Major AFEX decomposition products are less inhibitory to yeast fermentation than the products of dilute acid or steam explosion pretreatments; thus, ACH is readily fermentable by yeast without any detoxification.« less

  19. Carbonaceous film coating

    DOE Patents [OSTI]

    Maya, Leon

    1989-01-01

    A method of making a carbonaceous film comprising heating tris(1,3,2-benzodiazaborolo)borazine or dodecahydro tris[1,3,2]diazaborine[1,2-a:1'2'-c:1"2"-e]borazine in an inert atmosphere in the presence of a substrate to a temperature at which the borazine compound decomposes, and the decomposition products deposit onto the substrate to form a thin, tenacious, highly reflective conductive coating having a narrow band gap which is susceptible of modification and a relatively low coefficient of friction.

  20. Gas phase thermochemistry of organogermanium compounds

    SciTech Connect (OSTI)

    Engel, J.P.

    1993-12-07

    A variety of silyl- and alkyl-germylene precursors have been synthesized and subsequently pyrolyzed in the gas phase. Arrhenius parameters were obtained employing a pulsed-stirred flow reactor for these unimolecular decompositions. These precursors are divided into two major categories by mechanism of germylene extrusion: {alpha}-elimination precursors and germylacetylenes. The extrusion of germylenes from germylacetylene precursors is of primary interest. A mechanism is proposed employing a germacyclopropene intermediate. Evidence supporting this mechanism is presented. In the process of exploring germylacetylenes as germylene precursors, an apparent dyatropic rearrangement between germanium and silicon was observed. This rearrangement was subsequently explored.