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Sample records for measures miec oxides

  1. AP-XPS Measures MIEC Oxides in Action

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

    AP-XPS Measures MIEC Oxides in Action Print Oxide materials with mixed ionic-electronic conductivity (MIEC) can conduct both electrons and oxygen ions. MIEC oxides have broad...

  2. AP-XPS Measures MIEC Oxides in Action

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

    AP-XPS Measures MIEC Oxides in Action AP-XPS Measures MIEC Oxides in Action Print Wednesday, 25 May 2011 00:00 Oxide materials with mixed ionic-electronic conductivity (MIEC) can conduct both electrons and oxygen ions. MIEC oxides have broad applications, including use in solid-oxide fuel cells, high-temperature electrolysis for synthetic fuel production, and oxygen-separating membranes for chemical processes or NOx-free combustion; however, their surface activity under reaction conditions has

  3. AP-XPS Measures MIEC Oxides in Action

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

    Measures MIEC Oxides in Action Print Wednesday, 25 May 2011 00:00 Oxide materials with mixed ionic-electronic conductivity (MIEC) can conduct both electrons and oxygen ions....

  4. AP-XPS Measures MIEC Oxides in Action

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

    AP-XPS Measures MIEC Oxides in Action Print Oxide materials with mixed ionic-electronic conductivity (MIEC) can conduct both electrons and oxygen ions. MIEC oxides have broad applications, including use in solid-oxide fuel cells, high-temperature electrolysis for synthetic fuel production, and oxygen-separating membranes for chemical processes or NOx-free combustion; however, their surface activity under reaction conditions has been difficult, if not impossible, to ascertain, until recently. A

  5. AP-XPS Measures MIEC Oxides in Action

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

    AP-XPS Measures MIEC Oxides in Action Print Oxide materials with mixed ionic-electronic conductivity (MIEC) can conduct both electrons and oxygen ions. MIEC oxides have broad applications, including use in solid-oxide fuel cells, high-temperature electrolysis for synthetic fuel production, and oxygen-separating membranes for chemical processes or NOx-free combustion; however, their surface activity under reaction conditions has been difficult, if not impossible, to ascertain, until recently. A

  6. AP-XPS Measures MIEC Oxides in Action

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

    AP-XPS Measures MIEC Oxides in Action Print Oxide materials with mixed ionic-electronic conductivity (MIEC) can conduct both electrons and oxygen ions. MIEC oxides have broad applications, including use in solid-oxide fuel cells, high-temperature electrolysis for synthetic fuel production, and oxygen-separating membranes for chemical processes or NOx-free combustion; however, their surface activity under reaction conditions has been difficult, if not impossible, to ascertain, until recently. A

  7. AP-XPS Measures MIEC Oxides in Action

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

    AP-XPS Measures MIEC Oxides in Action Print Oxide materials with mixed ionic-electronic conductivity (MIEC) can conduct both electrons and oxygen ions. MIEC oxides have broad applications, including use in solid-oxide fuel cells, high-temperature electrolysis for synthetic fuel production, and oxygen-separating membranes for chemical processes or NOx-free combustion; however, their surface activity under reaction conditions has been difficult, if not impossible, to ascertain, until recently. A

  8. AP-XPS Measures MIEC Oxides in Action

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

    AP-XPS Measures MIEC Oxides in Action Print Oxide materials with mixed ionic-electronic conductivity (MIEC) can conduct both electrons and oxygen ions. MIEC oxides have broad applications, including use in solid-oxide fuel cells, high-temperature electrolysis for synthetic fuel production, and oxygen-separating membranes for chemical processes or NOx-free combustion; however, their surface activity under reaction conditions has been difficult, if not impossible, to ascertain, until recently. A

  9. AP-XPS Measures MIEC Oxides in Action

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

    for synthetic fuel production, and oxygen-separating membranes for chemical processes or NOx-free combustion; however, their surface activity under reaction conditions has been...

  10. AP-XPS Measures MIEC Oxides in Action

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

    model materials that may be used in high-temperature water splitting to make hydrogen gas (H2). Understanding how the surfaces react under different conditions provides a...

  11. AP-XPS Measures MIEC Oxides in Action

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

    improved strategies and materials to move these technologies forward for clean power generation and fuel production. Research conducted by C. Zhang, S. DeCaluwe, G. Jackson,...

  12. AP-XPS Measures MIEC Oxides in Action

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

    like electrolysis, from renewable power sources, like water, allowing for either a sustainable hydrogen economy or sustainable production of synthetic hydrocarbon fuels. The...

  13. AP-XPS Measures MIEC Oxides in Action

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

    of active electrode surfaces using x-ray photoelectron spectroscopy (XPS); therefore, the research community has lacked quantitative data on these materials' surface redox cycles...

  14. Measuring and modeling the lifetime of nitrous oxide including...

    Office of Scientific and Technical Information (OSTI)

    Published Article: Measuring and modeling the lifetime of nitrous oxide including its variability: NITROUS OXIDE AND ITS CHANGING LIFETIME Prev Next Title: Measuring and ...

  15. Measuring Real-time Biological and Abiotic Manganese Oxide Reduction |

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

    Stanford Synchrotron Radiation Lightsource Measuring Real-time Biological and Abiotic Manganese Oxide Reduction Tuesday, May 31, 2016 Manganese(IV) oxides are powerful scavengers of toxins and trace metals, but they are also strong oxidants in the environment (1). Certain common microbes can also 'breathe' manganese oxides, in a process known as anaerobic respiration (2). During these environmental -commonly with sulfur or iron species- and biological interactions, manganese oxides are often

  16. The role of probe oxide in local surface conductivity measurements

    SciTech Connect (OSTI)

    Barnett, C. J.; Kryvchenkova, O.; Wilson, L. S. J.; Maffeis, T. G. G.; Cobley, R. J.; Kalna, K.

    2015-05-07

    Local probe methods can be used to measure nanoscale surface conductivity, but some techniques including nanoscale four point probe rely on at least two of the probes forming the same low resistivity non-rectifying contact to the sample. Here, the role of probe shank oxide has been examined by carrying out contact and non-contact I V measurements on GaAs when the probe oxide has been controllably reduced, both experimentally and in simulation. In contact, the barrier height is pinned but the barrier shape changes with probe shank oxide dimensions. In non-contact measurements, the oxide modifies the electrostatic interaction inducing a quantum dot that alters the tunneling behavior. For both, the contact resistance change is dependent on polarity, which violates the assumption required for four point probe to remove probe contact resistance from the measured conductivity. This has implications for all nanoscale surface probe measurements and macroscopic four point probe, both in air and vacuum, where the role of probe oxide contamination is not well understood.

  17. Reporting central tendencies of chamber measured surface emission and oxidation

    SciTech Connect (OSTI)

    Abichou, Tarek; Clark, Jeremy; Chanton, Jeffery

    2011-05-15

    Methane emissions, concentrations, and oxidation were measured on eleven MSW landfills in eleven states spanning from California to Pennsylvania during the three year study. The flux measurements were performed using a static chamber technique. Initial concentration samples were collected immediately after placement of the flux chamber. Oxidation of the emitted methane was evaluated using stable isotope techniques. When reporting overall surface emissions and percent oxidation for a landfill cover, central tendencies are typically used to report 'averages' of the collected data. The objective of this study was to determine the best way to determine and report central tendencies. Results showed that 89% of the data sets of collected surface flux have lognormal distributions, 83% of the surface concentration data sets are also lognormal. Sixty seven percent (67%) of the isotope measured percent oxidation data sets are normally distributed. The distribution of data for all eleven landfills provides insight of the central tendencies of emissions, concentrations, and percent oxidation. When reporting the 'average' measurement for both flux and concentration data collected at the surface of a landfill, statistical analyses provided insight supporting the use of the geometric mean. But the arithmetic mean can accurately represent the percent oxidation, as measured with the stable isotope technique. We examined correlations between surface CH{sub 4} emissions and surface air CH{sub 4} concentrations. Correlation of the concentration and flux values using the geometric mean proved to be a good fit (R{sup 2} = 0.86), indicating that surface scans are a good way of identifying locations of high emissions.

  18. An outline of positron measurements of superconducting oxides

    SciTech Connect (OSTI)

    Howell, R.H.; Fluss, M.J.

    1991-03-01

    Positron measurements on superconducting oxides have gone through an evolution from divergent results of low statistical precision on samples of suspect quality to convergent results of higher statistical precision on high quality samples. We outline the elements affecting the progress of these experiments and questions that can be addressed at our present state of the art. 11 refs.

  19. Solid oxide fuel cells having porous cathodes infiltrated with oxygen-reducing catalysts

    DOE Patents [OSTI]

    Liu, Meilin; Liu, Ze; Liu, Mingfei; Nie, Lifang; Mebane, David Spencer; Wilson, Lane Curtis; Surdoval, Wayne

    2014-08-12

    Solid-oxide fuel cells include an electrolyte and an anode electrically coupled to a first surface of the electrolyte. A cathode is provided, which is electrically coupled to a second surface of the electrolyte. The cathode includes a porous backbone having a porosity in a range from about 20% to about 70%. The porous backbone contains a mixed ionic-electronic conductor (MIEC) of a first material infiltrated with an oxygen-reducing catalyst of a second material different from the first material.

  20. Synthesis and characterization of R{sub 2}MnTiO{sub 7} (R = Y and Er) pyrochlores oxides

    SciTech Connect (OSTI)

    Martnez-Coronado, R.; Alonso, J.A.; Fernndez, M.T.

    2013-09-01

    Graphical abstract: - Abstract: New pyrochlore-like phases of composition R{sub 2}MnTiO{sub 7} (R = Er and Y) have been synthesized by a soft-chemistry procedure involving citrates of the different metal ions followed by thermal treatments at moderate temperatures (850 C for 12 h in air). A characterization by X-ray diffraction and neutron powder diffraction (NPD) has been carried out in order to determine the crystal structure features: these phyrochlores are cubic, space group Fd-3m, defining an intrinsically frustrated three-dimensional system. The Rietveld-refinement from NPD data at room temperature evidences an antisite cation disorder (distribution of Mn between A and B positions) that is accompanied by an increment of the oxygen-vacancy concentration due to the reduction of Mn{sup 4+} at the B position to Mn{sup 2+} at the A position. Thermogravimetric analysis (TGA) was useful to evaluate the stability of these oxides in reducing conditions up to 500 C. Magnetic susceptibility measurements indicate a ferromagnetic behavior, due to the random distribution of Mn{sup 4+} ions in the octahedral sublattice. At lower temperatures there is a polarization of the R{sup +3} magnetic moments, which also participate in the magnetic structure. Aiming to evaluate these materials as possible electrodes for solid oxide fuel cells (SOFC) we determined that the thermal expansion coefficients between 100 and 900 C perfectly match with those of the usual electrolytes; however, these pyrochlore oxides display a semiconductor-like behavior with poor conductivity values, e.g. 6 10{sup ?3} cm{sup ?1} at 850 C for Er, which would prevent its use as MIEC (mixed ionic-electronic conductors) oxides in SOFC devices.

  1. On-Board Measurement of Ammonia and Nitrous Oxide Using Feedback...

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

    Laser Spectroscopy Combined with Amplified Resonance and Low Pressure Sampling On-Board Measurement of Ammonia and Nitrous Oxide Using Feedback Absorption Laser ...

  2. Kinetics of visible light photo-oxidation of Ge nanocrystals:Theory and in situ measurement

    SciTech Connect (OSTI)

    Sharp, I.D.; Xu, Q.; Yuan, C.W.; Beeman, J.W.; Ager III, J.W.; Chrzan, D.C.; Haller, E.E.

    2006-11-14

    Photo-oxidation of Ge nanocrystals illuminated with visible laser light under ambient conditions was investigated. The photo-oxidation kinetics were monitored by in situ measurement of the crystalline Ge volume fraction by Raman spectroscopy. The effects of laser power and energy on the extent of oxidation were measured using both in situ and ex situ Raman scattering techniques. A mechanistic model in which the tunneling of photo-excited carriers to the oxide surface for electron activated molecular oxygen dissociation is proposed. This quantitative model successfully describes all experimental photo-oxidation observations using physical parameters.

  3. Hydrogen measurement during steam oxidation using coupled thermogravimetric analysis and quadrupole mass spectrometry

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

    Parkison, Adam J.; Nelson, Andrew Thomas

    2016-01-11

    An analytical technique is presented with the goal of measuring reaction kinetics during steam oxidation reactions for three cases in which obtaining kinetics information often requires a prohibitive amount of time and cost. The technique presented relies on coupling thermogravimetric analysis (TGA) with a quantitative hydrogen measurement technique using quadrupole mass spectrometry (QMS). The first case considered is in differentiating between the kinetics of steam oxidation reactions and those for simultaneously reacting gaseous impurities such as nitrogen or oxygen. The second case allows one to independently measure the kinetics of oxide and hydride formation for systems in which both ofmore » these reactions are known to take place during steam oxidation. The third case deals with measuring the kinetics of formation for competing volatile and non-volatile oxides during certain steam oxidation reactions. In order to meet the requirements of the coupled technique, a methodology is presented which attempts to provide quantitative measurement of hydrogen generation using QMS in the presence of an interfering fragmentation species, namely water vapor. This is achieved such that all calibrations and corrections are performed during the TGA baseline and steam oxidation programs, making system operation virtually identical to standard TGA. Benchmarking results showed a relative error in hydrogen measurement of 5.7–8.4% following the application of a correction factor. Lastly, suggestions are made for possible improvements to the presented technique so that it may be better applied to the three cases presented.« less

  4. On-Board Measurement of Ammonia and Nitrous Oxide Using Feedback Absorption

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

    Laser Spectroscopy Combined with Amplified Resonance and Low Pressure Sampling | Department of Energy Board Measurement of Ammonia and Nitrous Oxide Using Feedback Absorption Laser Spectroscopy Combined with Amplified Resonance and Low Pressure Sampling On-Board Measurement of Ammonia and Nitrous Oxide Using Feedback Absorption Laser Spectroscopy Combined with Amplified Resonance and Low Pressure Sampling A first set of results has found that LASAR and VLPS data in the laboratory closely

  5. Oxide

    SciTech Connect (OSTI)

    2014-07-15

    Oxide is a modular framework for feature extraction and analysis of executable files. Oxide is useful in a variety of reverse engineering and categorization tasks relating to executable content.

  6. Measurements of the oxidation state and concentration of plutonium in interstitial waters of the Irish Sea

    SciTech Connect (OSTI)

    Nelson, D.M.; Lovett, M.B.

    1980-01-01

    The question of plutonium movement in interstitial waters resulting from diffusion along concentration gradients or from advective flow is addressed. The results of measurements of both the concentration and the oxidation state of plutonium in interstitial water collected from sediments near the Windscale discharge, in the solid phases of these sediments and in seawater and suspended solids collected at the coring locations are discussed. (ACR)

  7. The underwater coincidence counter for plutonium measurements in mixed-oxide fuel assemblies manual

    SciTech Connect (OSTI)

    G. W. Eccleston; H. O. Menlove; M. Abhold; M. Baker; J. Pecos

    1999-05-01

    This manual describes the Underwater Coincidence Counter (UWCC) that has been designed for the measurement of plutonium in mixed-oxide (MOX) fuel assemblies prior to irradiation. The UWCC uses high-efficiency {sup 3}He neutron detectors to measure the spontaneous-fission and induced-fission rates in the fuel assembly. Measurements can be made on MOX fuel assemblies in air or underwater. The neutron counting rate is analyzed for singles, doubles, and triples time correlations to determine the {sup 240}Pu effective mass per unit length of the fuel assembly. The system can verify the plutonium loading per unit length to a precision of less than 1% in a measurement time of 2 to 3 minutes. System design, components, performance tests, and operational characteristics are described in this manual.

  8. O/M RATIO MEASUREMENT IN PURE AND MIXED OXIDE FULES - WHERE ARE WE NOW?

    SciTech Connect (OSTI)

    J. RUBIN; ET AL

    2000-12-01

    The oxygen-to-metal (O/M) ratio is one of the most critical parameters of nuclear fuel fabrication, and its measurement is closely monitored for manufacturing process control and to ensure the service behavior of the final product. Thermogravimetry is the most widely used method, the procedure for which has remained largely unchanged since its development some thirty years ago. It was not clear to us, however, that this method is still the optimum one in light of advances in instrumentation, and in the current regulatory environment, particularly with regard to waste management and disposal. As part of the MOX fuel fabrication program at Los Alamos, we conducted a comprehensive review of methods for O/M measurements in UO{sub 2}, PuO{sub 2} and mixed oxide fuels for thermal reactors. A concerted effort was made to access information not available in the open literature. We identified approximately thirty five experimental methods that (a) have been developed with the intent of measuring O/M, (b) provided O/M indirectly by suitable reduction of the measured data, or (c) could provide O/M data with suitable data reduction or when combined with other methods. We will discuss the relative strengths and weaknesses of these methods in their application to current routine and small-lot production environment.

  9. Method Evaluation And Field Sample Measurements For The Rate Of Movement Of The Oxidation Front In Saltstone

    SciTech Connect (OSTI)

    Almond, P. M.; Kaplan, D. I.; Langton, C. A.; Stefanko, D. B.; Spencer, W. A.; Hatfield, A.; Arai, Y.

    2012-08-23

    The objective of this work was to develop and evaluate a series of methods and validate their capability to measure differences in oxidized versus reduced saltstone. Validated methods were then applied to samples cured under field conditions to simulate Performance Assessment (PA) needs for the Saltstone Disposal Facility (SDF). Four analytical approaches were evaluated using laboratory-cured saltstone samples. These methods were X-ray absorption spectroscopy (XAS), diffuse reflectance spectroscopy (DRS), chemical redox indicators, and thin-section leaching methods. XAS and thin-section leaching methods were validated as viable methods for studying oxidation movement in saltstone. Each method used samples that were spiked with chromium (Cr) as a tracer for oxidation of the saltstone. The two methods were subsequently applied to field-cured samples containing chromium to characterize the oxidation state of chromium as a function of distance from the exposed air/cementitious material surface.

  10. Correlating hydrogen oxidation and evolution activity on platinum at different pH with measured hydrogen binding energy

    SciTech Connect (OSTI)

    Sheng, WC; Zhuang, ZB; Gao, MR; Zheng, J; Chen, JGG; Yan, YS

    2015-01-08

    The hydrogen oxidation/evolution reactions are two of the most fundamental reactions in distributed renewable electrochemical energy conversion and storage systems. The identification of the reaction descriptor is therefore of critical importance for the rational catalyst design and development. Here we report the correlation between hydrogen oxidation/evolution activity and experimentally measured hydrogen binding energy for polycrystalline platinum examined in several buffer solutions in a wide range of electrolyte pH from 0 to 13. The hydrogen oxidation/evolution activity obtained using the rotating disk electrode method is found to decrease with the pH, while the hydrogen binding energy, obtained from cyclic voltammograms, linearly increases with the pH. Correlating the hydrogen oxidation/evolution activity to the hydrogen binding energy renders a monotonic decreasing hydrogen oxidation/evolution activity with the hydrogen binding energy, strongly supporting the hypothesis that hydrogen binding energy is the sole reaction descriptor for the hydrogen oxidation/evolution activity on monometallic platinum.

  11. Oxidation growth stresses in an alumina-forming ferritic steel measured by creep deflection

    SciTech Connect (OSTI)

    Saunders, S.R.J.; Gohil, D.D.; Osgerby, S.

    1997-10-01

    Deflection tests have been used to estimate the stresses developed in the alumina layer formed during short-term oxidation of a Fe-22Cr-5Al-0.3Y Fecralloy steel at 1000{degrees}C. Elastic analysis of the deflecting specimen is inappropriate under these test conditions because of the low creep strength of the alloy. Accordingly, a recent creep analysis has been used in this work using currently determined creep properties of the alloy substrate. The results of the analysis show that for the thin oxides produced (< 1 {mu}m), the planar stress within the oxide layer is everywhere compressive. Average values are approximately 850 MPa after 0.5 hr oxidation but reduce to < 200 MPa after 6.5 hr. These values are very much less than would be expected under conditions of elastic deformation.

  12. Interagency nitric oxide measurement investigation: AEDC results for phase III (comparison of optical and probe measurements of nitric oxide concentration in combustors). Final report, October 1979-January 1980

    SciTech Connect (OSTI)

    Few, J.D.; Lowry, H.S. III; McGregor, W.K.

    1981-01-01

    The purpose of Phase III of this program was to measure NO concentration on three successively more complicated combustion systems using both optical and probe techniques. The results of all measurements, both probe and optical, were compared and analyzed. Generally, the NO concentrations determined by the optical method were no larger than 30 percent above the values obtained with probes for a methane/air flat-frame burner, a propane/air swirl combustor, and a liquid-fueled simulated jet engine combustor. Close examination of the data revealed that probe results were influenced by some chemical reaction. The probes were designed for subsonic, atmospheric pressure flows, and arguments are presented to show that the agreement found in these experiments need not be expected in near sonic or supersonic flow using the same probe designs.

  13. Note: Ion-induced secondary electron emission from oxidized metal surfaces measured in a particle beam reactor

    SciTech Connect (OSTI)

    Marcak, Adrian; Corbella, Carles Keudell, Achim von; Arcos, Teresa de los

    2015-10-15

    The secondary electron emission of metals induced by slow ions is characterized in a beam chamber by means of two coaxial semi-cylindrical electrodes with different apertures. The voltages of the outer electrode (screening), inner electrode (collector), and sample holder (target) were set independently in order to measure the effective yield of potential and kinetic electron emissions during ion bombardment. Aluminum samples were exposed to quantified beams of argon ions up to 2000 eV and to oxygen atoms and molecules in order to mimic the plasma-surface interactions on metallic targets during reactive sputtering. The variation of electron emission yield was correlated to the ion energy and to the oxidation state of Al surfaces. This system provides reliable measurements of the electron yields in real time and is of great utility to explore the fundamental surface processes during target poisoning occurring in reactive magnetron sputtering applications.

  14. Characterization of aluminum oxide tunnel barriers by combining transport measurements and transmission electron microscopy imaging

    SciTech Connect (OSTI)

    Aref, T.; Averin, A.; Nguyend, H. Q.; Pekola, J. P.; Dijken, S. van; Yao, L. D.; Ferring, A.; Koberidze, M.; Nieminen, R. M.

    2014-08-21

    We present two approaches for studying the uniformity of a tunnel barrier. The first approach is based on measuring single-electron and two-electron tunneling in a hybrid single-electron transistor. Our measurements indicate that the effective area of a conduction channel is about one order of magnitude larger than predicted by theoretical calculations. With the second method, transmission electron microscopy, we demonstrate that variations in the barrier thickness are a plausible explanation for the larger effective area and an enhancement of higher order tunneling processes.

  15. Thermodynamic behavior of high-T sub c oxide systems via EMF and related measurements

    SciTech Connect (OSTI)

    Tetenbaum, M.; Tumidajaski, P.; Bloom, I.D.; Brown, D.L.; Blander, M.

    1991-01-01

    EMF measurements of oxygen fugacities as a function of stoichiometry have been made in the YBa{sub 2}Cu{sub 3}O{sub x}, and NdBa{sub 2}Cu{sub 3}O{sub x}, and Nd{sub 1.81}Ce{sub 0.19}CuO{sub x} superconducting systems in the temperature range 400--750{degree}C by means of an oxygen titration technique with an yttria-stabilized zirconia electrolyte. The object of our current measurements is to investigate the effect of ionic size of Y, Gd and Nd on the thermodynamic behavior and structural transition in the LnBa{sub 2}Cu{sub 3}O{sub x} system. The shape of the 400{degree}C isotherm for NdBa{sub 2}Cu{sub 3}O{sub x} suggests the presence of a miscibility gap at lower temperatures, at values of x that are higher than those in the YBa{sub 2}Cu{sub 3}O{sub x} system. The locations of the miscibility gaps are consistent with the effects of ionic radii on the composition dependence of {Tc} for these systems. Our results explain the two plateaus in measured value of {Tc} as a function of composition for the YBa{sub 2}Cu{sub 3}O{sub x} system and appear to be consistent with the less pronounced {Tc} plateaus found for the NdBa{sub 2}Cu{sub 3}O{sub x} system higher stoichiometry values. For a given oxygen stoichiometry, partial pressures of oxygen above NdBa{sub 2}Cu{sub 3}O{sub x} are higher than for the YBa{sub 2}Cu{sub 3}O{sub x} system in accord with calculated partial molar thermodynamic quantities. The results of limited measurements on the n-type (electron-doped) superconducting Nd{sub 1.81}Ce{sub 0.19}CuO{sub x} system will be presented. A thermodynamic assessment and intercomparison of our oxygen partial pressure measurements with the results of other measurements will be presented. 34 refs., 9 figs., 1 tab.

  16. Direct Determination of Equilibrium Potentials for Hydrogen Oxidation/Production by Open Circuit Potential Measurements in Acetonitrile

    SciTech Connect (OSTI)

    Roberts, John A.; Bullock, R. Morris

    2013-03-14

    Open circuit potentials were measured for acetonitrile solutions of a variety of acids and their conjugate bases under 1 atm H2. Acids examined include triethylammonium, dimethylformamidium, 2,6-dichloroanilinium, 4-cyanoanilinium, 4-bromoanilinium, and 4-anisidinium salts. These potentials, together with the pKa values of the acids, establish the value of the standard hydrogen electrode (SHE) potential in acetonitrile as ?0.028(4) V vs the ferrocenium/ferrocene couple. Dimethylformamidium is shown to form homoconjugates and other aggregates with dimethylformamide; open circuit potentials are used to quantify the extent of these reactions. Overpotentials for electrocatalytic hydrogen production and oxidation were determined from open circuit potentials and voltammograms of acidic or basic catalyst solutions under H2. This method requires neither pKa values, homoconjugation constants, nor an estimate for the SHE potential and thus allows direct comparison of catalytic systems in different media.

  17. New Measurements of the Solubility of Metal Oxides at High Temperature

    SciTech Connect (OSTI)

    G.A. Palmer; P. Benezeth; D.J. Wesolowski; S.A. Wood; C. Xiao

    2000-06-30

    The results of high temperature solubility studies at ORNL are presented in which mainly direct pH measurements were made of aqueous solutions in contact with the crystalline solid phases: Al(OH){sub 3}, AlOOH, Fe{sub 3}O{sub 4}, Mg(OH){sub 2}, Nd(OH){sub 3}, and ZnO. Examples are highlighted of specific phenomena such as: the kinetics of gibbsite and boehmite dissolution and precipitation; the appearance of metastable equilibria in the dissolution of Fe{sub 3}O{sub 4}; the extremely rapid precipitation of crystalline brucite, Mg(OH){sub 2}; and anomalies in the apparent solubility profiles of AlO(OH) and ZnO. General trends associated with the effects of temperature and ionic strength are mentioned. Some of the potentiometric investigations were augmented by conventional batch [AlO(OH) and ZnO], and flow-through column (ZnO) experiments. In the additional case of ZnCr{sub 2}O{sub 4}, the extremely low solubility of this spinel permitted application of only the latter technique and these results are discussed in terms of the measured chromium levels that resulted from incongruent dissolution.

  18. In-situ DRIFTS measurements for the mechanistic study of NO oxidation over a commercial Cu-CHA catalyst

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

    Ruggeri, Maria Pia; Nova, Isabella; Tronconi, Enrico; Pihl, Josh A.; Toops, Todd J.; Partridge, Jr., William P.

    2014-11-03

    We report a mechanistic DRIFTS in-situ study of NO2, NO + O2 and NO adsorption on a commercial Cu-CHA catalyst for NH3-SCR of NOx. Both pre-reduced and pre-oxidized catalyst samples were investigated with the aim of clarifying mechanistic aspects of the NO oxidation to NO2 as a preliminary step towards the study of the Standard SCR reaction mechanism at low temperatures. Nitrosonium cations (NO+, N formal oxidation state = +3) were identified as key surface intermediates in the process of NO (+2) oxidation to NO2 (+4) and nitrates (+5). While NO+ and nitrates were formed simultaneously upon catalyst exposure tomore » NO2, nitrates evolved consecutively to NO+ when the catalyst was exposed to NO + O2, suggesting that nitrite-like species, and not NO2, are formed as the primary products of the NO oxidative activation over Cu-CHA. Upon catalyst exposure to NO only, i.e. in the absence of gaseous O2, NO+ and then nitrates were formed on a pre-oxidized sample but not on a pre-reduced one, which demonstrates the red-ox nature of the NO oxidation mechanism. The negative effect of H2O on NO+ and nitrates formation was also clearly established. Assuming Cu dimers as the active sites for NO oxidation to NO2, we propose a mechanism which reconciles all the experimental observations. Specifically, we show that such a mechanism also explains the observed kinetic effects of H2O, O2 and NO2 on the NO oxidation activity of the investigated Cu zeolite catalyst.« less

  19. In-situ DRIFTS measurements for the mechanistic study of NO oxidation over a commercial Cu-CHA catalyst

    SciTech Connect (OSTI)

    Ruggeri, Maria Pia; Nova, Isabella; Tronconi, Enrico; Pihl, Josh A.; Toops, Todd J.; Partridge, Jr., William P.

    2014-11-03

    We report a mechanistic DRIFTS in-situ study of NO2, NO + O2 and NO adsorption on a commercial Cu-CHA catalyst for NH3-SCR of NOx. Both pre-reduced and pre-oxidized catalyst samples were investigated with the aim of clarifying mechanistic aspects of the NO oxidation to NO2 as a preliminary step towards the study of the Standard SCR reaction mechanism at low temperatures. Nitrosonium cations (NO+, N formal oxidation state = +3) were identified as key surface intermediates in the process of NO (+2) oxidation to NO2 (+4) and nitrates (+5). While NO+ and nitrates were formed simultaneously upon catalyst exposure to NO2, nitrates evolved consecutively to NO+ when the catalyst was exposed to NO + O2, suggesting that nitrite-like species, and not NO2, are formed as the primary products of the NO oxidative activation over Cu-CHA. Upon catalyst exposure to NO only, i.e. in the absence of gaseous O2, NO+ and then nitrates were formed on a pre-oxidized sample but not on a pre-reduced one, which demonstrates the red-ox nature of the NO oxidation mechanism. The negative effect of H2O on NO+ and nitrates formation was also clearly established. Assuming Cu dimers as the active sites for NO oxidation to NO2, we propose a mechanism which reconciles all the experimental observations. Specifically, we show that such a mechanism also explains the observed kinetic effects of H2O, O2 and NO2 on the NO oxidation activity of the investigated Cu zeolite catalyst.

  20. QUALIFICATION OF THE SAVANNAH RIVER SITE 252CF SHUFFLER FOR RECEIPT VERIFICATION MEASUREMENTS OF MIXED U-PU OXIDES STORED IN 9975 SHIPPING CONTAINERS

    SciTech Connect (OSTI)

    Dubose, F.

    2011-05-26

    To extend their ability to perform accountability and verification measurements of {sup 235}U in a U-Pu oxide matrix, the K-Area Material Storage facility commissioned the development and construction of a Passive/Active {sup 252}Cf Shuffler. A series of {sup 252}Cf, PuO{sub 2}, and U-Pu oxide standards, in addition to a single U{sub 3}O{sub 8} standard, were measured to characterize and calibrate the shuffler. Accompanying these measurements were simulations using MCNP5/MCNPX, aimed at isolating the neutron countrate contributions for each of the isotopes present. Two calibration methods for determining the {sup 235}U content in mixed UPu oxide were then developed, yielding comparable results. The first determines the {sup 235}U mass by estimating the {sup 239}Pu/{sup 235}U ratio-dependent contributions from the primary delayed neutron contributors. The second defines an average linear response based on the {sup 235}U and {sup 239}Pu mass contents. In each case, it was observed that self-shielding due to {sup 235}U mass has a large influence on the observed rates, requiring bounds on the applicable limits of each calibration method.

  1. Chemistry of α-pinene and naphthalene oxidation products generated in a Potential Aerosol Mass (PAM) chamber as measured by acetate chemical ionization mass spectrometry

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

    Chhabra, P. S.; Lambe, A. T.; Canagaratna, M. R.; Stark, H.; Jayne, J. T.; Onasch, T. B.; Davidovits, P.; Kimmel, J. R.; Worsnop, D. R.

    2014-07-01

    Recent developments in high resolution, time-of-flight chemical ionization mass spectrometry (HR-ToF-CIMS) have made possible the direct detection of atmospheric organic compounds in real-time with high sensitivity and with little or no fragmentation, including low volatility, highly oxygenated organic vapors that are precursors to secondary organic aerosol formation. Here, for the first time, we examine gas-phase O3 and OH oxidation products of α-pinene and naphthalene formed in the PAM flow reactor with an HR-ToF-CIMS using acetate reagent ion chemistry. Integrated OH exposures ranged from 1.2 × 1011 to 9.7 × 1011 molec cm−3 s, corresponding to approximately 1.0 to 7.5 daysmore » of equivalent atmospheric oxidation. Measured gas-phase organic acids are similar to those previously observed in environmental chamber studies. For both precursors, we find that acetate-CIMS spectra capture both functionalization (oxygen addition) and fragmentation (carbon loss) as a function of OH exposure. The level of fragmentation is observed to increase with increased oxidation. We present a method that estimates vapor pressures of organic molecules using the measured O/C ratio, H/C ratio, and carbon number for each compound detected by the CIMS. The predicted condensed-phase SOA average acid yields and O/C and H/C ratios agree within uncertainties with previous AMS measurements and ambient CIMS results. While acetate reagent ion chemistry is used to selectively measure organic acids, in principle this method can be applied to additional reagent ion chemistries depending on the application.« less

  2. Application of high-resolution time-of-flight chemical ionization mass spectrometry measurements to estimate volatility distributions of α-pinene and naphthalene oxidation products

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

    Chhabra, P. S.; Lambe, A. T.; Canagaratna, M. R.; Stark, H.; Jayne, J. T.; Onasch, T. B.; Davidovits, P.; Kimmel, J. R.; Worsnop, D. R.

    2015-01-05

    Recent developments in high-resolution time-of-flight chemical ionization mass spectrometry (HR-ToF-CIMS) have made it possible to directly detect atmospheric organic compounds in real time with high sensitivity and with little or no fragmentation, including low-volatility, highly oxygenated organic vapors that are precursors to secondary organic aerosol formation. Here, using ions identified by high-resolution spectra from an HR-ToF-CIMS with acetate reagent ion chemistry, we develop an algorithm to estimate the vapor pressures of measured organic acids. The algorithm uses identified ion formulas and calculated double bond equivalencies, information unavailable in quadrupole CIMS technology, as constraints for the number of possible oxygen-containing functionalmore » groups. The algorithm is tested with acetate chemical ionization mass spectrometry (acetate-CIMS) spectra of O3 and OH oxidation products of α-pinene and naphthalene formed in a flow reactor with integrated OH exposures ranged from 1.2 × 1011 to 9.7 × 1011 molec s cm−3, corresponding to approximately 1.0 to 7.5 days of equivalent atmospheric oxidation. Measured gas-phase organic acids are similar to those previously observed in environmental chamber studies. For both precursors, we find that acetate-CIMS spectra capture both functionalization (oxygen addition) and fragmentation (carbon loss) as a function of OH exposure. The level of fragmentation is observed to increase with increased oxidation. The predicted condensed-phase secondary organic aerosol (SOA) average acid yields and O/C and H/C ratios agree within uncertainties with previous chamber and flow reactor measurements and ambient CIMS results. While acetate reagent ion chemistry is used to selectively measure organic acids, in principle this method can be applied to additional reagent ion chemistries depending on the application.« less

  3. The combustion chemistry of a fuel tracer: Measured flame speeds and ignition delays and a detailed chemical kinetic model for the oxidation of acetone

    SciTech Connect (OSTI)

    Pichon, S.; Black, G.; Simmie, J.M.; Curran, H.J.; Chaumeix, N.; Yahyaoui, M.; Donohue, R.

    2009-02-15

    Acetone ignition delay and stretch-free laminar flame speed measurements have been carried out and a kinetic model has been developed to simulate these and literature data for acetone and for ketene, which was found to be an important intermediate in its oxidation. The mechanism has been based on one originally devised for dimethyl ether and modified through validation of the hydrogen, carbon monoxide and methane sub-mechanisms. Acetone oxidation in argon was studied behind reflected shock waves in the temperature range 1340-1930 K, at 1 atm and at equivalence ratios of 0.5, 1 and 2; it is also shown that the addition of up to 15% acetone to a stoichiometric n-heptane mixture has no effect on the measured ignition delay times. Flame speeds at 298 K and 1 atm of pure acetone in air were measured in a spherical bomb; a maximum flame speed of {proportional_to}35 cm s{sup -1} at {phi}=1.15 is indicated. (author)

  4. Measurement

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

    magnetic fluctuation-induced particle flux "invited... a... W. X. Ding, D. L. Brower, and T. Y. Yates Department of Physics and Astronomy, University of California-Los Angeles, Los Angeles, California 90095, USA ͑Presented 13 May 2008; received 12 May 2008; accepted 16 May 2008; published online 31 October 2008͒ Magnetic field fluctuation-induced particle transport has been directly measured in the high-temperature core of the MST reversed field pinch plasma. Measurement of radial

  5. Photoionization mass spectrometric measurements of initial reaction pathways in low-temperature oxidation of 2,5-dimethylhexane

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

    Rotavera, Brandon; Zádor, Judit; Welz, Oliver; Sheps, Leonid; Scheer, Adam M.; Savee, John D.; Akbar Ali, Mohamad; Lee, Taek Soon; Simmons, Blake A.; Osborn, David L.; et al

    2014-09-19

    The product formation from R + O2 reactions relevant to low-temperature autoignition chemistry was studied for 2,5-dimethylhexane, a symmetrically branched octane isomer, at 550 and 650 K using Cl-atom initiated oxidation and multiplexed photoionization mass spectrometry (MPIMS). The interpretation of time- and photon-energy-resolved mass spectra led to three specific results important to characterizing the initial oxidation steps: (1) quantified isomer-resolved branching ratios for HO2 + alkene channels; (2) 2,2,5,5-tetramethyltetrahydrofuran is formed in substantial yield from addition of O2 to tertiary 2,5-dimethylhex-2-yl followed by isomerization of the resulting ROO adduct to tertiary hydroperoxyalkyl (QOOH) and exhibits a positive dependence on temperaturemore » over the range covered leading to a higher flux relative to aggregate cyclic ether yield. The higher relative flux is explained by a 1,5-hydrogen atom shift reaction that converts the initial primary alkyl radical (2,5-dimethylhex-1-yl) to the tertiary alkyl radical 2,5-dimethylhex-2-yl, providing an additional source of tertiary alkyl radicals. Furthermore, quantum-chemical and master-equation calculations of the unimolecular decomposition of the primary alkyl radical reveal that isomerization to the tertiary alkyl radical is the most favorable pathway, and is favored over O2-addition at 650 K under the conditions herein. The isomerization pathway to tertiary alkyl radicals therefore contributes an additional mechanism to 2,2,5,5-tetramethyltetrahydrofuran formation; (3) carbonyl species (acetone, propanal, and methylpropanal) consistent with β-scission of QOOH radicals were formed in significant yield, indicating unimolecular QOOH decomposition into carbonyl + alkene + OH.« less

  6. Photoionization mass spectrometric measurements of initial reaction pathways in low-temperature oxidation of 2,5-dimethylhexane

    SciTech Connect (OSTI)

    Rotavera, Brandon; Zádor, Judit; Welz, Oliver; Sheps, Leonid; Scheer, Adam M.; Savee, John D.; Akbar Ali, Mohamad; Lee, Taek Soon; Simmons, Blake A.; Osborn, David L.; Violi, Angela; Taatjes, Craig A.

    2014-09-19

    The product formation from R + O2 reactions relevant to low-temperature autoignition chemistry was studied for 2,5-dimethylhexane, a symmetrically branched octane isomer, at 550 and 650 K using Cl-atom initiated oxidation and multiplexed photoionization mass spectrometry (MPIMS). The interpretation of time- and photon-energy-resolved mass spectra led to three specific results important to characterizing the initial oxidation steps: (1) quantified isomer-resolved branching ratios for HO2 + alkene channels; (2) 2,2,5,5-tetramethyltetrahydrofuran is formed in substantial yield from addition of O2 to tertiary 2,5-dimethylhex-2-yl followed by isomerization of the resulting ROO adduct to tertiary hydroperoxyalkyl (QOOH) and exhibits a positive dependence on temperature over the range covered leading to a higher flux relative to aggregate cyclic ether yield. The higher relative flux is explained by a 1,5-hydrogen atom shift reaction that converts the initial primary alkyl radical (2,5-dimethylhex-1-yl) to the tertiary alkyl radical 2,5-dimethylhex-2-yl, providing an additional source of tertiary alkyl radicals. Furthermore, quantum-chemical and master-equation calculations of the unimolecular decomposition of the primary alkyl radical reveal that isomerization to the tertiary alkyl radical is the most favorable pathway, and is favored over O2-addition at 650 K under the conditions herein. The isomerization pathway to tertiary alkyl radicals therefore contributes an additional mechanism to 2,2,5,5-tetramethyltetrahydrofuran formation; (3) carbonyl species (acetone, propanal, and methylpropanal) consistent with β-scission of QOOH radicals were formed in significant yield, indicating unimolecular QOOH decomposition into carbonyl + alkene + OH.

  7. Agreement of central site measurements and land use regression modeled oxidative potential of PM{sub 2.5} with personal exposure

    SciTech Connect (OSTI)

    Yang, Aileen; Hoek, Gerard; Montagne, Denise; Leseman, Daan L.A.C.; Hellack, Bryan; Kuhlbusch, Thomas A.J.; Cassee, Flemming R.; Brunekreef, Bert; Janssen, Nicole A.H.

    2015-07-15

    Oxidative potential (OP) of ambient particulate matter (PM) has been suggested as a health-relevant exposure metric. In order to use OP for exposure assessment, information is needed about how well central site OP measurements and modeled average OP at the home address reflect temporal and spatial variation of personal OP. We collected 96-hour personal, home outdoor and indoor PM{sub 2.5} samples from 15 volunteers living either at traffic, urban or regional background locations in Utrecht, the Netherlands. OP was also measured at one central reference site to account for temporal variations. OP was assessed using electron spin resonance (OP{sup ESR}) and dithiothreitol (OP{sup DTT}). Spatial variation of average OP at the home address was modeled using land use regression (LUR) models. For both OP{sup ESR} and OP{sup DTT}, temporal correlations of central site measurements with home outdoor measurements were high (R>0.75), and moderate to high (R=0.49–0.70) with personal measurements. The LUR model predictions for OP correlated significantly with the home outdoor concentrations for OP{sup DTT} and OP{sup ESR} (R=0.65 and 0.62, respectively). LUR model predictions were moderately correlated with personal OP{sup DTT} measurements (R=0.50). Adjustment for indoor sources, such as vacuum cleaning and absence of fume-hood, improved the temporal and spatial agreement with measured personal exposure for OP{sup ESR}. OP{sup DTT} was not associated with any indoor sources. Our study results support the use of central site OP for exposure assessment of epidemiological studies focusing on short-term health effects. - Highlights: • Oxidative potential (OP) of PM was proposed as a health-relevant exposure metric. • We evaluated the relationship between measured and modeled outdoor and personal OP. • Temporal correlations of central site with personal OP are moderate to high. • Adjusting for indoor sources improved the agreement with personal OP. • Our results

  8. Measurement

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

    Neutrino Induced, Charged Current, Charged Pion Production by Michael Joseph Wilking B.Ch.E., University of Minnesota, 2001 M.S., University of Colorado, 2007 A thesis submitted to the Faculty of the Graduate School of the University of Colorado in partial fulfillment of the requirements for the degree of Doctor of Philosophy Department of Physics 2009 This thesis entitled: Measurement of Neutrino Induced, Charged Current, Charged Pion Production written by Michael Joseph Wilking has been

  9. Measurement

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

    core velocity fluctuations and the dynamo in a reversed-field pinch * D. J. Den Hartog, †,a) J. T. Chapman, b) D. Craig, G. Fiksel, P. W. Fontana, S. C. Prager, and J. S. Sarff Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706 ͑Received 16 November 1998; accepted 20 January 1999͒ Plasma flow velocity fluctuations have been directly measured in the high-temperature magnetically confined plasma in the Madison Symmetric Torus ͑MST͒

  10. Measurement

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

    1 H( 7 Be, 8 B)γ cross section by Ryan P. Fitzgerald A dissertation submitted to the faculty of the University of North Carolina at Chapel Hill in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Physics & Astronomy. Chapel Hill 2005 Approved: A. E. Champagne, Advisor J. C. Blackmon, Reader C. Iliadis, Reader ABSTRACT Ryan P. Fitzgerald: Measurement of the 1 H( 7 Be, 8 B)γ cross section (Under the Direction of A. E. Champagne) The fusion

  11. Measurement

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

    interpretation of micro benchmark and application energy use on the Cray XC30 Brian Austin, and Nicholas J. Wright ⇤ August 29, 2014 Abstract Understanding patterns of application energy use is key to reaching future HPC e ciency goals. We have measured the sensitivity of en- ergy use to CPU frequency for several microbenchmarks and applications on a Cray XC30. First order fits to the performance and power data are su cient to describe the energy used by these applications. Exam- ination of

  12. Measurement

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

    Electronegative Contaminants and Drift Electron Lifetime in the MicroBooNE Experiment The MicroBooNE Collaboration May 19, 2016 Abstract High-purity liquid argon is critical for the operation of a liquid argon time projec- tion chamber (LArTPC). At MicroBooNE, we have achieved an electron drift lifetime of at least 6 ms without evacuation of the detector vessel. Measurements of the elec- tronegative contaminants oxygen and water are described and shown as the gas and liquid argon stages of

  13. Time-Resolved Quantitative Measurement of OH HO2 and CH2O in Fuel Oxidation Reactions by High Resolution IR Absorption Spectroscopy.

    SciTech Connect (OSTI)

    Huang, Haifeng; Rotavera, Brandon; Taatjes, Craig A.

    2014-08-01

    Combined with a Herriott-type multi-pass slow flow reactor, high-resolution differential direct absorption spectroscopy has been used to probe, in situ and quantitatively, hydroxyl (OH), hydroperoxy (HO 2 ) and formaldehyde (CH 2 O) molecules in fuel oxidation reactions in the reactor, with a time resolution of about 1 micro-second. While OH and CH 2 O are probed in the mid-infrared (MIR) region near 2870nm and 3574nm respectively, HO 2 can be probed in both regions: near-infrared (NIR) at 1509nm and MIR at 2870nm. Typical sensitivities are on the order of 10 10 - 10 11 molecule cm -3 for OH at 2870nm, 10 11 molecule cm -3 for HO 2 at 1509nm, and 10 11 molecule cm -3 for CH 2 O at 3574nm. Measurements of multiple important intermediates (OH and HO 2 ) and product (CH 2 O) facilitate to understand and further validate chemical mechanisms of fuel oxidation chemistry.

  14. An improved characterization method for international accountancy measurements of fresh and irradiated mixed oxide (MOX) fuel: helping achieve continual monitoring and safeguards through the fuel cycle

    SciTech Connect (OSTI)

    Evans, Louise G; Croft, Stephen; Swinhoe, Martyn T; Tobin, S. J.; Boyer, B. D.; Menlove, H. O.; Schear, M. A.; Worrall, Andrew

    2010-11-24

    Nuclear fuel accountancy measurements are conducted at several points through the nuclear fuel cycle to ensure continuity of knowledge (CofK) of special nuclear material (SNM). Non-destructive assay (NDA) measurements are performed on fresh fuel (prior to irradiation in a reactor) and spent nuclear fuel (SNF) post-irradiation. We have developed a fuel assembly characterization system, based on the novel concept of 'neutron fingerprinting' with multiplicity signatures to ensure detailed CofK of nuclear fuel through the entire fuel cycle. The neutron fingerprint in this case is determined by the measurement of the various correlated neutron signatures, specific to fuel isotopic composition, and therefore offers greater sensitivity to variations in fissile content among fuel assemblies than other techniques such as gross neutron counting. This neutron fingerprint could be measured at the point of fuel dispatch (e.g. from a fuel fabrication plant prior to irradiation, or from a reactor site post-irradiation), monitored during transportation of the fuel assembly, and measured at a subsequent receiving site (e.g. at the reactor site prior to irradiation, or reprocessing facility post-irradiation); this would confirm that no unexpected changes to the fuel composition or amount have taken place during transportation and/or reactor operations. Changes may indicate an attempt to divert material for example. Here, we present the current state of the practice of fuel measurements for both fresh mixed oxide (MOX) fuel and SNF (both MOX and uranium dioxide). This is presented in the framework of international safeguards perspectives from the US and UK. We also postulate as to how the neutron fingerprinting concept could lead to improved fuel characterization (both fresh MOX and SNF) resulting in: (a) assured CofK of fuel across the nuclear fuel cycle, (b) improved detection of SNM diversion, and (c) greater confidence in safeguards of SNF transportation.

  15. An improved characterization method for international accountancy measurements of fresh and irradiated mixed oxide (MOX) fuel: helping achieve continual monitoring and safeguards through the fuel cycle

    SciTech Connect (OSTI)

    Evans, Louise G; Croft, Stephen; Swinhoe, Martyn T; Tobin, S. J.; Menlove, H. O.; Schear, M. A.; Worrall, Andrew

    2011-01-13

    Nuclear fuel accountancy measurements are conducted at several points through the nuclear fuel cycle to ensure continuity of knowledge (CofK) of special nuclear material (SNM). Non-destructive assay (NDA) measurements are performed on fresh fuel (prior to irradiation in a reactor) and spent nuclear fuel (SNF) post-irradiation. We have developed a fuel assembly characterization system, based on the novel concept of 'neutron fingerprinting' with multiplicity signatures to ensure detailed CofK of nuclear fuel through the entire fuel cycle. The neutron fingerprint in this case is determined by the measurement of the various correlated neutron signatures, specific to fuel isotopic composition, and therefore offers greater sensitivity to variations in fissile content among fuel assemblies than other techniques such as gross neutron counting. This neutron fingerprint could be measured at the point of fuel dispatch (e.g. from a fuel fabrication plant prior to irradiation, or from a reactor site post-irradiation), monitored during transportation of the fuel assembly, and measured at a subsequent receiving site (e.g. at the reactor site prior to irradiation, or reprocessing facility post-irradiation); this would confirm that no unexpected changes to the fuel composition or amount have taken place during transportation and/ or reactor operations. Changes may indicate an attempt to divert material for example. Here, we present the current state of the practice of fuel measurements for both fresh mixed oxide (MOX) fuel and SNF (both MOX and uranium dioxide). This is presented in the framework of international safeguards perspectives from the US and UK. We also postulate as to how the neutron fingerprinting concept could lead to improved fuel characterization (both fresh MOX and SNF) resulting in: (a) assured CofK of fuel across the nuclear fuel cycle, (b) improved detection of SNM diversion, and (c) greater confidence in safeguards of SNF transportation.

  16. Characterization and analysis methods for the examination of the heterogeneous solid oxide fuel cell electrode microstructure: Part 2. Quantitative measurement of the microstructure and contributions to transport losses

    SciTech Connect (OSTI)

    Grew, Kyle N.; Peracchio, Aldo A.; Chiu, W. K. S.

    2010-12-15

    Advanced characterization and analysis of multifunctional materials, such as the materials found in heterogeneous solid oxide fuel cell (SOFC) electrode architectures, can help to provide a qualitative and quantitative understanding of how these structures respond to different manufacturing and operating practices. Dense, opaque materials, which have large X-ray mass absorption coefficients and features on sub-micrometer length scales, can make characterization difficult. Advances in tomographic X-ray imaging can permit this level of detailed characterization, and complement stereographic scanning electron microscope measurements that have also been reported. In this second part of a two-part study, details regarding quantitative characterization methods that have been used to examine the SOFC anode microstructure are reported. The detailed formulation and validation of a phase size distributions for the three constitutive phases, as well as resistive loss microstructure-induced resistive loss distributions in the nickel (Ni) and yttria-stabilized zirconia (YSZ) phases are provided in this section.

  17. Development of Metal Oxide Nanostructure-based Optical Sensors for Fossil Fuel Derived Gases Measurement at High Temperature

    SciTech Connect (OSTI)

    Chen, Kevin

    2014-08-31

    This final technical report details research works performed supported by a Department of Energy grant (DE-FE0003859), which was awarded under the University Coal Research Program administrated by National Energy Technology Laboratory. This research program studied high temperature fiber sensor for harsh environment applications. It developed two fiber optical sensor platform technology including regenerative fiber Bragg grating sensors and distributed fiber optical sensing based on Rayleigh backscattering optical frequency domain reflectometry. Through the studies of chemical and thermal regenerative techniques for fiber Bragg grating (FBG) fabrication, high-temperature stable FBG sensors were successfully developed and fabricated in air-hole microstructured fibers, high-attenuation fibers, rare-earth doped fibers, and standard telecommunication fibers. By optimizing the laser processing and thermal annealing procedures, fiber grating sensors with stable performance up to 1100oC have been developed. Using these temperature-stable FBG gratings as sensor platform, fiber optical flow, temperature, pressure, and chemical sensors have been developed to operate at high temperatures up to 800oC. Through the integration of on-fiber functional coating, the use of application-specific air-hole microstructural fiber, and application of active fiber sensing scheme, distributed fiber sensor for temperature, pressure, flow, liquid level, and chemical sensing have been demonstrated with high spatial resolution (1-cm or better) with wide temperature ranges. These include the demonstration of 1) liquid level sensing from 77K to the room temperature, pressure/temperature sensing from the room temperature to 800C and from the 15psi to 2000 psi, and hydrogen concentration measurement from 0.2% to 10% with temperature ranges from the room temperature to 700C. Optical sensors developed by this program has broken several technical records including flow sensors with the highest

  18. Determination of active doping in highly resistive boron doped silicon nanocrystals embedded in SiO{sub 2} by capacitance voltage measurement on inverted metal oxide semiconductor structure

    SciTech Connect (OSTI)

    Zhang, Tian Puthen-Veettil, Binesh; Wu, Lingfeng; Jia, Xuguang; Lin, Ziyun; Yang, Terry Chien-Jen; Conibeer, Gavin; Perez-Wurfl, Ivan

    2015-10-21

    We investigate the Capacitance-Voltage (CV) measurement to study the electrically active boron doping in Si nanocrystals (ncSi) embedded in SiO{sub 2}. The ncSi thin films with high resistivity (200–400 Ω cm) can be measured by using an inverted metal oxide semiconductor (MOS) structure (Al/ncSi (B)/SiO{sub 2}/Si). This device structure eliminates the complications from the effects of lateral current flow and the high sheet resistance in standard lateral MOS structures. The characteristic MOS CV curves observed are consistent with the effective p-type doping. The CV modeling method is presented and used to evaluate the electrically active doping concentration. We find that the highly boron doped ncSi films have electrically active doping of 10{sup 18}–10{sup 19 }cm{sup −3} despite their high resistivity. The saturation of doping at about 1.4 × 10{sup 19 }cm{sup −3} and the low doping efficiency less than 5% are observed and discussed. The calculated effective mobility is in the order of 10{sup −3} cm{sup 2}/V s, indicating strong impurity/defect scattering effect that hinders carriers transport.

  19. Characterization and Analysis Methods for the Examination of the Heterogeneous Solid Oxide Fuel Cell Electrode Microstructure, Part 1: Volumetric Measurements of the Heterogeneous Structure

    SciTech Connect (OSTI)

    Grew, Kyle N.; Peracchio, Aldo A.; Joshi, Abhijit S.; Izzo, Jr., John R.; Chiu, W. K. S.

    2010-12-15

    Advanced imaging and characterization methods have permitted the 3-D and phase-specific reconstruction of dense and opaque samples with features that have a length scale on the order of tens of nanometers and comprised of materials with large X-ray mass absorption coefficients. Engineered materials, like those found in solid oxide fuel cell (SOFC) electrodes, use complex materials that have often limited opportunities to perform 3-D characterization and analysis. Still, characterization and analysis methods are needed to better understand these structures and their functional impact. The development, verification, and validation of methods used by the authors for the characterization and analysis of the heterogeneous SOFC anode are discussed in this work. These methods include the measurement of the volume fractions of the individual phases, contiguity or volumetric connectivity, tortuosity, and interfacial properties. A second and complementary part of this work will examine quantitative methods that provide detailed descriptions of the structure and its relations to the transport processes that it must support. These efforts are intended to describe the formulation of methods developed to provide insight into the SOFC anode nano/microstructure.

  20. The competing oxide and sub-oxide formation in metal-oxide molecular beam epitaxy

    SciTech Connect (OSTI)

    Vogt, Patrick; Bierwagen, Oliver

    2015-02-23

    The hetero-epitaxial growth of the n-type semiconducting oxides β-Ga{sub 2}O{sub 3}, In{sub 2}O{sub 3}, and SnO{sub 2} on c- and r-plane sapphire was performed by plasma-assisted molecular beam epitaxy. The growth-rate and desorbing flux from the substrate were measured in-situ under various oxygen to metal ratios by laser reflectometry and quadrupole mass spectrometry, respectively. These measurements clarified the role of volatile sub-oxide formation (Ga{sub 2}O, In{sub 2}O, and SnO) during growth, the sub-oxide stoichiometry, and the efficiency of oxide formation for the three oxides. As a result, the formation of the sub-oxides decreased the growth-rate under metal-rich growth conditions and resulted in etching of the oxide film by supplying only metal flux. The flux ratio for the exclusive formation of the sub-oxide (e.g., the p-type semiconductor SnO) was determined, and the efficiency of oxide formation was found to be the highest for SnO{sub 2}, somewhat lower for In{sub 2}O{sub 3}, and the lowest for Ga{sub 2}O{sub 3}. Our findings can be generalized to further oxides that possess related sub-oxides.

  1. Real-time measurements of secondary organic aerosol formation and aging from ambient air in an oxidation flow reactor in the Los Angeles area

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

    Ortega, Amber M.; Hayes, Patrick L.; Peng, Zhe; Palm, Brett B.; Hu, Weiwei; Day, Douglas A.; Li, Rui; Cubison, Michael J.; Brune, William H.; Graus, Martin; et al

    2016-06-15

    Field studies in polluted areas over the last decade have observed large formation of secondary organic aerosol (SOA) that is often poorly captured by models. The study of SOA formation using ambient data is often confounded by the effects of advection, vertical mixing, emissions, and variable degrees of photochemical aging. An oxidation flow reactor (OFR) was deployed to study SOA formation in real-time during the California Research at the Nexus of Air Quality and Climate Change (CalNex) campaign in Pasadena, CA, in 2010. A high-resolution aerosol mass spectrometer (AMS) and a scanning mobility particle sizer (SMPS) alternated sampling ambient andmore » reactor-aged air. The reactor produced OH concentrations up to 4 orders of magnitude higher than in ambient air. OH radical concentration was continuously stepped, achieving equivalent atmospheric aging of 0.8 days–6.4 weeks in 3 min of processing every 2 h. Enhancement of organic aerosol (OA) from aging showed a maximum net SOA production between 0.8–6 days of aging with net OA mass loss beyond 2 weeks. Reactor SOA mass peaked at night, in the absence of ambient photochemistry and correlated with trimethylbenzene concentrations. Reactor SOA formation was inversely correlated with ambient SOA and Ox, which along with the short-lived volatile organic compound correlation, indicates the importance of very reactive (τOH ~ 0.3 day) SOA precursors (most likely semivolatile and intermediate volatility species, S/IVOCs) in the Greater Los Angeles Area. Evolution of the elemental composition in the reactor was similar to trends observed in the atmosphere (O : C vs. H : C slope ~ –0.65). Oxidation state of carbon (OSc) in reactor SOA increased steeply with age and remained elevated (OSC ~ 2) at the highest photochemical ages probed. The ratio of OA in the reactor output to excess CO (ΔCO, ambient CO above regional background) vs. photochemical age is similar to previous studies at low to moderate ages and

  2. Magnetism of cuprate oxides

    SciTech Connect (OSTI)

    Shirane, G.

    1996-11-01

    A review is given of current neutron scattering experiments on cuprate oxides. We first discuss the extensive neutron measurements on high-Tc oxides: La{sub 2-x}Sr{sub x}CuO{sub 4} and related (La{sub 1.6-x}Nd{sub 0.4})Sr{sub x}CuO{sub 4}. The second topic is the spin- Peierls system Cu{sub 1-x}Zn{sub x}GeO{sub 3}, where a new type of antiferromagnetic phase has been discovered. 17 refs, 8 figs.

  3. Studies of Heterogeneously Catalyzed Liquid-Phase Alcohol Oxidation on Platinum bySum-frequency Generation Vibrational Spectroscopy and Reaction Rate Measurements

    SciTech Connect (OSTI)

    Thompson, Christopher

    2014-05-15

    Compared to many branches of chemistry, the molecular level study of catalytically active surfaces is young. Only with the invention of ultrahigh vacuum technology in the past half century has it been possible to carry out experiments that yield useful molecular information about the reactive occurrences at a surface. The reason is two-fold: low pressure is necessary to keep a surface clean for an amount of time long enough to perform an experiment, and most atomic scale techniques that are surface speci c (x-ray photoelectron spectroscopy, electron energy loss spectroscopy, Auger electron spectroscopy, etc.) cannot be used at ambient pressures, because electrons, which act as chemical probes in these techniques, are easily scattered by molecules. Sum-frequency generation (SFG) vibrational spectroscopy is one technique that can provide molecular level information from the surface without the necessity for high vacuum. Since the advent of SFG as a surface spectroscopic tool it has proved its worth in the studies of surface catalyzed reactions in the gas phase, with numerous reactions in the gas phase having been investigated on a multitude of surfaces. However, in situ SFG characterization of catalysis at the solid-liquid interface has yet to be thoroughly pursued despite the broad interest in the use of heterogeneous catalysts in the liquid phase as replacements for homogeneous counterparts. This work describes an attempt to move in that direction, applying SFG to study the solid-liquid interface under conditions of catalytic alcohol oxidation on platinum.

  4. Oxidation catalyst

    DOE Patents [OSTI]

    Ceyer, Sylvia T.; Lahr, David L.

    2010-11-09

    The present invention generally relates to catalyst systems and methods for oxidation of carbon monoxide. The invention involves catalyst compositions which may be advantageously altered by, for example, modification of the catalyst surface to enhance catalyst performance. Catalyst systems of the present invention may be capable of performing the oxidation of carbon monoxide at relatively lower temperatures (e.g., 200 K and below) and at relatively higher reaction rates than known catalysts. Additionally, catalyst systems disclosed herein may be substantially lower in cost than current commercial catalysts. Such catalyst systems may be useful in, for example, catalytic converters, fuel cells, sensors, and the like.

  5. The solubility of zinc oxide in 0.03 m NaTr as a function of temperature, with in situ pH measurement

    SciTech Connect (OSTI)

    Benezeth, P.; Palmer, D.A.; Wesolowski, D.J.

    1999-05-01

    The solubility of zincite (ZnO) has been measured in noncomplexing solutions over a wide range of pH{sub m} (4--11), and temperature (75--200 C) at 0.03 mol/kg ionic strength in NaTr media (sodium trifluoromethanesulfonate, a noncomplexing 1:1 electrolyte), in a hydrogen electrode concentration cell (HECC), which provided continuous in situ measurement of hydrogen ion molality. Total zinc content was analyzed by atomic absorption using graphite furnace, flame, and inductively coupled plasma (ICP) spectrometers. The direction of approach to the equilibrium saturation state was varied to demonstrate that the system was reversible thermodynamically. Separate experiments were performed in alkaline solutions (0.03 mol/kg NaOH) at 25 and 50 C in polypropylene syringes, and between 50 and 290 C in a Teflon-lined pressure vessel. The aim of these experiments was to reach higher pH{sub m} (>8 depending on the temperature) to determine the thermodynamic properties of the negatively charged species, Zn(OH){sub 3}{sup {minus}}. A least-squares regression of the results obtained at this ionic strength was used to determine the molal solubility products (Q{sub sn}) of zincite. The solubility products (Q{sub sn}) were extrapolated to infinite dilution (K{sub sn}), permitting calculation of the thermodynamic properties of aqueous species of zinc for comparison with previous work.

  6. Metal oxide composite dosimeter method and material

    DOE Patents [OSTI]

    Miller, Steven D.

    1998-01-01

    The present invention is a method of measuring a radiation dose wherein a radiation responsive material consisting essentially of metal oxide is first exposed to ionizing radiation. The metal oxide is then stimulating with light thereby causing the radiation responsive material to photoluminesce. Photons emitted from the metal oxide as a result of photoluminescence may be counted to provide a measure of the ionizing radiation.

  7. ARM - Measurement - Black carbon concentration

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

    of carbon in its very absorbing, elemental, non-organic, non-oxide form (e.g. graphite). Categories Aerosols, Atmospheric Carbon Instruments The above measurement is...

  8. Growth control of the oxidation state in vanadium oxide thin...

    Office of Scientific and Technical Information (OSTI)

    Growth control of the oxidation state in vanadium oxide thin films Prev Next Title: Growth control of the oxidation state in vanadium oxide thin films Authors: Lee, Shinbuhm ...

  9. The high pressure structure and equation of state of 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) up to 20 GPa: X-ray diffraction measurements and first principles molecular dynamics simulations

    SciTech Connect (OSTI)

    Stavou, Elissaios; Manaa, M. Riad; Zaug, Joseph M.; Kuo, I-Feng W.; Pagoria, Philip F.; Crowhurst, Jonathan C.; Armstrong, Michael R.; Kalkan, Bora

    2015-10-14

    Recent theoretical studies of 2,6-diamino-3,5-dinitropyrazine-1-oxide (C4H4N6O5 Lawrence Livermore Molecule No. 105, LLM-105) report unreacted high pressure equations of state that include several structural phase transitions, between 8 and 50 GPa, while one published experimental study reports equation of state (EOS) data up to a pressure of 6 GPa with no observed transition. Here we report the results of a synchrotron-based X-ray diffraction study and also ambient temperature isobaric-isothermal atomistic molecular dynamics simulations of LLM-105 up to 20 GPa. We find that the ambient pressure phase remains stable up to 20 GPa; there is no indication of a pressure induced phase transition. We do find a prominent decrease in b-axis compressibility starting at approximately 13 GPa and attribute the stiffening to a critical length where inter-sheet distance becomes similar to the intermolecular distance within individual sheets. The ambient temperature isothermal equation of state was determined through refinements of measured X-ray diffraction patterns. The pressure-volume data were fit using various EOS models to yield bulk moduli with corresponding pressure derivatives. As a result, we find very good agreement between the experimental and theoretically derived EOS.

  10. The high pressure structure and equation of state of 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) up to 20 GPa: X-ray diffraction measurements and first principles molecular dynamics simulations

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

    Stavou, Elissaios; Manaa, M. Riad; Zaug, Joseph M.; Kuo, I-Feng W.; Pagoria, Philip F.; Crowhurst, Jonathan C.; Armstrong, Michael R.; Kalkan, Bora

    2015-10-14

    Recent theoretical studies of 2,6-diamino-3,5-dinitropyrazine-1-oxide (C4H4N6O5 Lawrence Livermore Molecule No. 105, LLM-105) report unreacted high pressure equations of state that include several structural phase transitions, between 8 and 50 GPa, while one published experimental study reports equation of state (EOS) data up to a pressure of 6 GPa with no observed transition. Here we report the results of a synchrotron-based X-ray diffraction study and also ambient temperature isobaric-isothermal atomistic molecular dynamics simulations of LLM-105 up to 20 GPa. We find that the ambient pressure phase remains stable up to 20 GPa; there is no indication of a pressure induced phasemore » transition. We do find a prominent decrease in b-axis compressibility starting at approximately 13 GPa and attribute the stiffening to a critical length where inter-sheet distance becomes similar to the intermolecular distance within individual sheets. The ambient temperature isothermal equation of state was determined through refinements of measured X-ray diffraction patterns. The pressure-volume data were fit using various EOS models to yield bulk moduli with corresponding pressure derivatives. As a result, we find very good agreement between the experimental and theoretically derived EOS.« less

  11. lithium cobalt oxide cathode

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

    lithium cobalt oxide cathode - Sandia Energy Energy Search Icon Sandia Home Locations ... SunShot Grand Challenge: Regional Test Centers lithium cobalt oxide cathode Home...

  12. Photo-oxidation catalysts

    DOE Patents [OSTI]

    Pitts, J. Roland; Liu, Ping; Smith, R. Davis

    2009-07-14

    Photo-oxidation catalysts and methods for cleaning a metal-based catalyst are disclosed. An exemplary catalyst system implementing a photo-oxidation catalyst may comprise a metal-based catalyst, and a photo-oxidation catalyst for cleaning the metal-based catalyst in the presence of light. The exposure to light enables the photo-oxidation catalyst to substantially oxidize absorbed contaminants and reduce accumulation of the contaminants on the metal-based catalyst. Applications are also disclosed.

  13. Studies on supported metal oxide-oxide support interactions ...

    Office of Scientific and Technical Information (OSTI)

    Subject: 36 MATERIALS SCIENCE; 66 PHYSICS; CERIUM OXIDES; SURFACE PROPERTIES; ALUMINIUM OXIDES; COPPER OXIDES; BINDING ENERGY; X-RAY DIFFRACTION; INFRARED SPECTRA; VALENCE; ZINC ...

  14. Phase Discrimination through Oxidant Selection for Iron Oxide...

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

    Phase Discrimination through Oxidant Selection for Iron Oxide Ultrathin Films Home > Research > ANSER Research Highlights > Phase Discrimination through Oxidant Selection for Iron...

  15. Ferroelectricity in undoped hafnium oxide

    SciTech Connect (OSTI)

    Polakowski, Patrick; Müller, Johannes

    2015-06-08

    We report the observation of ferroelectric characteristics in undoped hafnium oxide thin films in a thickness range of 4–20 nm. The undoped films were fabricated using atomic layer deposition (ALD) and embedded into titanium nitride based metal-insulator-metal (MIM) capacitors for electrical evaluation. Structural as well as electrical evidence for the appearance of a ferroelectric phase in pure hafnium oxide was collected with respect to film thickness and thermal budget applied during titanium nitride electrode formation. Using grazing incidence X-Ray diffraction (GIXRD) analysis, we observed an enhanced suppression of the monoclinic phase fraction in favor of an orthorhombic, potentially, ferroelectric phase with decreasing thickness/grain size and for a titanium nitride electrode formation below crystallization temperature. The electrical presence of ferroelectricity was confirmed using polarization measurements. A remanent polarization P{sub r} of up to 10 μC cm{sup −2} as well as a read/write endurance of 1.6 × 10{sup 5} cycles was measured for the pure oxide. The experimental results reported here strongly support the intrinsic nature of the ferroelectric phase in hafnium oxide and expand its applicability beyond the doped systems.

  16. ARM - Measurements

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

    govMeasurementsAerosols

  17. ARM - Measurements

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

    govMeasurementsRadiometric

  18. Mixed Acid Oxidation

    SciTech Connect (OSTI)

    Pierce, R.A.

    1999-10-26

    Several non-thermal processes have been developed to destroy organic waste compounds using chemicals with high oxidation potentials. These efforts have focused on developing technologies that work at low temperatures, relative to incineration, to overcome many of the regulatory issues associated with obtaining permits for waste incinerators. One such technique with great flexibility is mixed acid oxidation. Mixed acid oxidation, developed at the Savannah River Site, uses a mixture of an oxidant (nitric acid) and a carrier acid (phosphoric acid). The carrier acid acts as a non-volatile holding medium for the somewhat volatile oxidant. The combination of acids allows appreciable amounts of the concentrated oxidant to remain in the carrier acid well above the oxidant''s normal boiling point.

  19. Growth control of the oxidation state in vanadium oxide thin...

    Office of Scientific and Technical Information (OSTI)

    Growth control of the oxidation state in vanadium oxide thin films Citation Details In-Document Search Title: Growth control of the oxidation state in vanadium oxide thin films ...

  20. Phase Discrimination through Oxidant Selection for Iron Oxide Ultrathin

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

    Films | ANSER Center | Argonne-Northwestern National Laboratory Phase Discrimination through Oxidant Selection for Iron Oxide Ultrathin Films Home > Research > ANSER Research Highlights > Phase Discrimination through Oxidant Selection for Iron Oxide Ultrathin Films

  1. NO2 oxidation reactivity and burning mode of diesel particulates

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

    Strzelec, Andrea; Vander Wal, Randy L.; Thompson, Thomas N.; Toops, Todd J.; Daw, C. Stuart

    2016-03-24

    The NO2 oxidation kinetics and burning mode for diesel particulate from light-duty and medium-duty engines fueled with either ultra low sulfur diesel or soy methyl ester biodiesel blends have been investigated and are shown to be significantly different from oxidation by O2. Oxidation kinetics were measured using a flow-through packed bed microreactor for temperature programmed reactions and isothermal differential pulsed oxidation reactions. The burning mode was evaluated using the same reactor system for flowing BET specific surface area measurements and HR-TEM with fringe analysis to evaluate the nanostructure of the nascent and partially oxidized particulates. The low activation energy measured,more » specific surface area progression with extent of oxidation, HR-TEM images and difference plots of fringe length and tortuosity paint a consistent picture of higher reactivity for NO2, which reacts indiscriminately immediately upon contact with the surface, leading to the Zone I or shrinking core type oxidation. In comparison, O2 oxidation is shown to have relatively lower reactivity, preferentially attacking highly curved lamella, which are more reactive due to bond strain, and short lamella, which have a higher proportion of more reactive edge sites. Furthermore, this preferential oxidation leads to Zone II type oxidation, where solid phase diffusion of oxygen via pores contributes significantly to slowing the overall oxidation rate, by comparison.« less

  2. Note on Graphite Oxidation by Oxygen and Moisture

    SciTech Connect (OSTI)

    Wichner, Robert; Burchell, Timothy D; Contescu, Cristian I

    2009-02-01

    Simplified equations of graphite oxidation are reviewed for semi-infinite slab, finite slab, and cylinder geometries, using the principal assumptions of linearized oxidation kinetics and quasi-steady state oxidation profile. All equations are coupled to a general surface mass transfer boundary condition. The equations include those for oxidant concentration distribution, surface oxidation rate, burnoff profile, and oxidation efficiency. This review also covers some areas that may not be well recognized. The key role of the effective diffusivity is highlighted, with a brief review of measured values. The temperature-dependence of the surface oxidation rate is shown to be more complex than usually shown for the diffusion-affected zone. Assumption of linear kinetics permits ready estimation of equilibration time for development of the quasi-steady burnoff profile. In addition, approximations for the time-steady hydrogen concentration profiles are developed for the case of oxidation by H2O. All cited methods can be readily evaluated by spreadsheet calculation.

  3. Partial oxidation catalyst

    DOE Patents [OSTI]

    Krumpelt, Michael; Ahmed, Shabbir; Kumar, Romesh; Doshi, Rajiv

    2000-01-01

    A two-part catalyst comprising a dehydrogenation portion and an oxide-ion conducting portion. The dehydrogenation portion is a group VIII metal and the oxide-ion conducting portion is selected from a ceramic oxide crystallizing in the fluorite or perovskite structure. There is also disclosed a method of forming a hydrogen rich gas from a source of hydrocarbon fuel in which the hydrocarbon fuel contacts a two-part catalyst comprising a dehydrogenation portion and an oxide-ion conducting portion at a temperature not less than about 400.degree. C. for a time sufficient to generate the hydrogen rich gas while maintaining CO content less than about 5 volume percent. There is also disclosed a method of forming partially oxidized hydrocarbons from ethanes in which ethane gas contacts a two-part catalyst comprising a dehydrogenation portion and an oxide-ion conducting portion for a time and at a temperature sufficient to form an oxide.

  4. ZIRCONIUM OXIDE NANOSTRUCTURES PREPARED BY ANODIC OXIDATION

    SciTech Connect (OSTI)

    Dang, Y. Y.; Bhuiyan, M.S.; Paranthaman, M. P.

    2008-01-01

    Zirconium oxide is an advanced ceramic material highly useful for structural and electrical applications because of its high strength, fracture toughness, chemical and thermal stability, and biocompatibility. If highly-ordered porous zirconium oxide membranes can be successfully formed, this will expand its real-world applications, such as further enhancing solid-oxide fuel cell technology. Recent studies have achieved various morphologies of porous zirconium oxide via anodization, but they have yet to create a porous layer where nanoholes are formed in a highly ordered array. In this study, electrochemical methods were used for zirconium oxide synthesis due to its advantages over other coating techniques, and because the thickness and morphology of the ceramic fi lms can be easily tuned by the electrochemical parameters, such as electrolyte solutions and processing conditions, such as pH, voltage, and duration. The effects of additional steps such as pre-annealing and post-annealing were also examined. Results demonstrate the formation of anodic porous zirconium oxide with diverse morphologies, such as sponge-like layers, porous arrays with nanoholes ranging from 40 to 75 nm, and nanotube layers. X-ray powder diffraction analysis indicates a cubic crystallographic structure in the zirconium oxide. It was noted that increased voltage improved the ability of the membrane to stay adhered to the zirconium substrate, whereas lower voltages caused a propensity for the oxide fi lm to fl ake off. Further studies are needed to defi ne the parameters windows that create these morphologies and to investigate other important characteristics such as ionic conductivity.

  5. Oxidation Resistant Graphite Studies

    SciTech Connect (OSTI)

    W. Windes; R. Smith

    2014-07-01

    The Very High Temperature Reactor (VHTR) Graphite Research and Development Program is investigating doped nuclear graphite grades exhibiting oxidation resistance. During a oxygen ingress accident the oxidation rates of the high temperature graphite core region would be extremely high resulting in significant structural damage to the core. Reducing the oxidation rate of the graphite core material would reduce the structural effects and keep the core integrity intact during any air-ingress accident. Oxidation testing of graphite doped with oxidation resistant material is being conducted to determine the extent of oxidation rate reduction. Nuclear grade graphite doped with varying levels of Boron-Carbide (B4C) was oxidized in air at nominal 740°C at 10/90% (air/He) and 100% air. The oxidation rates of the boronated and unboronated graphite grade were compared. With increasing boron-carbide content (up to 6 vol%) the oxidation rate was observed to have a 20 fold reduction from unboronated graphite. Visual inspection and uniformity of oxidation across the surface of the specimens were conducted. Future work to determine the remaining mechanical strength as well as graphite grades with SiC doped material are discussed.

  6. ARM - Measurements

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

    govMeasurementsCloud Properties

  7. ARM - Measurements

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

    govMeasurementsSurface Properties

  8. Barium oxide, calcium oxide, magnesia, and alkali oxide free glass

    DOE Patents [OSTI]

    Lu, Peizhen Kathy; Mahapatra, Manoj Kumar

    2013-09-24

    A glass composition consisting essentially of about 10-45 mole percent of SrO; about 35-75 mole percent SiO.sub.2; one or more compounds from the group of compounds consisting of La.sub.2O.sub.3, Al.sub.2O.sub.3, B.sub.2O.sub.3, and Ni; the La.sub.2O.sub.3 less than about 20 mole percent; the Al.sub.2O.sub.3 less than about 25 mole percent; the B.sub.2O.sub.3 less than about 15 mole percent; and the Ni less than about 5 mole percent. Preferably, the glass is substantially free of barium oxide, calcium oxide, magnesia, and alkali oxide. Preferably, the glass is used as a seal in a solid oxide fuel/electrolyzer cell (SOFC) stack. The SOFC stack comprises a plurality of SOFCs connected by one or more interconnect and manifold materials and sealed by the glass. Preferably, each SOFC comprises an anode, a cathode, and a solid electrolyte.

  9. METAL OXIDE NANOPARTICLES

    SciTech Connect (OSTI)

    FERNANDEZ-GARCIA,M.; RODGRIGUEZ, J.A.

    2007-10-01

    This chapter covers the fundamental science, synthesis, characterization, physicochemical properties and applications of oxide nanomaterials. Explains fundamental aspects that determine the growth and behavior of these systems, briefly examines synthetic procedures using bottom-up and top-down fabrication technologies, discusses the sophisticated experimental techniques and state of the art theory results used to characterize the physico-chemical properties of oxide solids and describe the current knowledge concerning key oxide materials with important technological applications.

  10. ARM - Oxides of Nitrogen

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

    Oxides of Nitrogen Outreach Home Room News Publications Traditional Knowledge Kiosks Barrow, Alaska Tropical Western Pacific Site Tours Contacts Students Study Hall About ARM Global Warming FAQ Just for Fun Meet our Friends Cool Sites Teachers Teachers' Toolbox Lesson Plans Oxides of Nitrogen Oxides of nitrogen, chlorofluorocarbons (CFCs), and ozone have a lesser effect on the atmosphere than carbon dioxide and methane, but as you will see they are important contributors to the greenhouse

  11. Superconductive ceramic oxide combination

    SciTech Connect (OSTI)

    Chatterjee, D.K.; Mehrotra, A.K.; Mir, J.M.

    1991-03-05

    This patent describes the combination of a superconductive ceramic oxide which degrades in conductivity upon contact of ambient air with its surface and, interposed between the ceramic oxide surface and ambient air in the amount of at least 1 mg per square meter of surface area of the superconductive ceramic oxide, a passivant polymer selected from the group consisting of a polyester ionomer and an alkyl cellulose.

  12. OXIDATION OF TRANSURANIC ELEMENTS

    DOE Patents [OSTI]

    Moore, R.L.

    1959-02-17

    A method is reported for oxidizing neptunium or plutonium in the presence of cerous values without also oxidizing the cerous values. The method consists in treating an aqueous 1N nitric acid solution, containing such cerous values together with the trivalent transuranic elements, with a quantity of hydrogen peroxide stoichiometrically sufficient to oxidize the transuranic values to the hexavalent state, and digesting the solution at room temperature.

  13. Mixed oxide solid solutions

    DOE Patents [OSTI]

    Magno, Scott; Wang, Ruiping; Derouane, Eric

    2003-01-01

    The present invention is a mixed oxide solid solution containing a tetravalent and a pentavalent cation that can be used as a support for a metal combustion catalyst. The invention is furthermore a combustion catalyst containing the mixed oxide solid solution and a method of making the mixed oxide solid solution. The tetravalent cation is zirconium(+4), hafnium(+4) or thorium(+4). In one embodiment, the pentavalent cation is tantalum(+5), niobium(+5) or bismuth(+5). Mixed oxide solid solutions of the present invention exhibit enhanced thermal stability, maintaining relatively high surface areas at high temperatures in the presence of water vapor.

  14. Investigation of NO2 Oxidation Kinetics and Burning Mode for Medium Duty

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

    Diesel Particulate: Contrasting O2 and NO2 Oxidation | Department of Energy NO2 Oxidation Kinetics and Burning Mode for Medium Duty Diesel Particulate: Contrasting O2 and NO2 Oxidation Investigation of NO2 Oxidation Kinetics and Burning Mode for Medium Duty Diesel Particulate: Contrasting O2 and NO2 Oxidation Reports on preliminary measurements of particulate reactivity and changes in microstructure upon exposure to NO2, which is often present at significant levels in diesel engine exhaust.

  15. Aromatics oxidation and soot formation in flames

    SciTech Connect (OSTI)

    Howard, J.B.; Pope, C.J.; Shandross, R.A.; Yadav, T.

    1993-12-01

    This project is concerned with the kinetics and mechanisms of aromatics oxidation and soot and fullerenes formation in flames. The scope includes detailed measurements of profiles of stable and radical species concentrations in low-pressure one-dimensional premixed flames. Intermediate species identifications and mole fractions, fluxes, and net reaction rates calculated from the measured profiles are used to test postulated reaction mechanisms. Particular objectives are to identify and to determine or confirm rate constants for the main benzene oxidation reactions in flames, and to characterize fullerenes and their formation mechanisms and kinetics.

  16. Analysis of uranium oxide weathering by molecular spectroscopy. Final report

    SciTech Connect (OSTI)

    Zickafoose, M.S.

    1997-11-01

    A preliminary study of the weathering of uranium oxide particles diluted in diamond dust at ambient environmental conditions is presented. The primary weathering reaction is oxidation of the uranium from the +4 to +6 oxidation state, although formation of compounds such as carbonates and hydroxides is possible. Identification of the state of uranium oxide has been attempted using luminescence spectroscopy and diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS). Luminescence spectra of nominal samples of three common oxides, UO3, U3O8, and UO2, have been measured showing significant spectral differences in peaks at 494 nm, 507 nm, 529 nm, and 553 nm. DRIFTS spectra of the same three oxides show significant differences in peaks at 960 /cm, 856 /cm, and 754 /cm. The differences in these peaks allow determination of the oxidation to the +6 state in these compounds.

  17. Reducible oxide based catalysts

    DOE Patents [OSTI]

    Thompson, Levi T.; Kim, Chang Hwan; Bej, Shyamal K.

    2010-04-06

    A catalyst is disclosed herein. The catalyst includes a reducible oxide support and at least one noble metal fixed on the reducible oxide support. The noble metal(s) is loaded on the support at a substantially constant temperature and pH.

  18. Stabilized chromium oxide film

    DOE Patents [OSTI]

    Nyaiesh, A.R.; Garwin, E.L.

    1986-08-04

    Stabilized air-oxidized chromium films deposited on high-power klystron ceramic windows and sleeves having a thickness between 20 and 150A are useful in lowering secondary electron emission yield and in avoiding multipactoring and window failure due to overheating. The ceramic substrate for the film is chosen from alumina, sapphire or beryllium oxide.

  19. Stabilized chromium oxide film

    DOE Patents [OSTI]

    Garwin, Edward L.; Nyaiesh, Ali R.

    1988-01-01

    Stabilized air-oxidized chromium films deposited on high-power klystron ceramic windows and sleeves having a thickness between 20 and 150.ANG. are useful in lowering secondary electron emission yield and in avoiding multipactoring and window failure due to overheating. The ceramic substrate for the film is chosen from alumina, sapphire or beryllium oxide.

  20. Nucleation and growth of oxide islands during the initial-stage oxidation of (100)Cu-Pt alloys

    SciTech Connect (OSTI)

    Luo, Langli; Zhou, Guangwen; Kang, Yihong; Yang, Judith C.

    2015-02-14

    The initial-stage oxidation of (100) Cu-Pt alloys has been examined by in situ environmental transmission electron microscopy and ex situ atomic force microscopy (AFM). It is shown that the oxidation proceeds via the nucleation and growth of Cu{sub 2}O islands that show dependence on the alloy composition and oxidation temperature. The kinetic measurements on the oxide nucleation reveal that both the nucleation density and surface coverage of Cu{sub 2}O islands can be promoted by alloying more Pt in the Cu-Pt alloys. Increasing the oxidation temperature above 700 °C results in the growth of large Cu{sub 2}O islands that transits to a dendritic growth morphology. The ex situ AFM studies reveal that the nucleation of oxide islands can occur on surface terraces and the subsequent oxide growth depletes local terrace Cu atoms that results in the formation of surface pits.

  1. ARM - Measurement - Trace gas concentration

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

    govMeasurementsTrace gas concentration ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Trace gas concentration The amount per unit volume of trace gases other than carbon dioxide, nitrogen oxides, ozone and water vapor, typically measured in conjunction with in situ aerosol measurements, e.g. carbon monoxide, and sulfur dioxide. Categories Atmospheric State, Atmospheric Carbon Instruments The above

  2. Magnetic interactions in manganese oxide

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

    Manganese oxide Magnetic interactions in manganese oxide Revealing the mechanism of 'superexchange' May 24, 2016 manganese oxide Manganese oxide Revealing the Nature of Magnetic Interactions in Manganese Oxide For nearly 60 years, scientists have been trying to determine how manganese oxide (MnO) achieves its long-range magnetic order of alternating up and down electron spins. Now, a team of scientists has used their recently developed mathematical approach to study the short-range magnetic

  3. NEPTUNIUM OXIDE PROCESSING

    SciTech Connect (OSTI)

    Jordan, J; Watkins, R; Hensel, S

    2009-05-27

    The Savannah River Site's HB-Line Facility completed a campaign in which fifty nine cans of neptunium oxide were produced and shipped to the Idaho National Laboratory in the 9975 shipping container. The neptunium campaign was divided into two parts: Part 1 which consisted of oxide made from H-Canyon neptunium solution which did not require any processing prior to conversion into an oxide, and Part 2 which consisted of oxide made from additional H-Canyon neptunium solutions which required processing to purify the solution prior to conversion into an oxide. The neptunium was received as a nitrate solution and converted to oxide through ion-exchange column extraction, precipitation, and calcination. Numerous processing challenges were encountered in order make a final neptunium oxide product that could be shipped in a 9975 shipping container. Among the challenges overcome was the issue of scale: translating lab scale production into full facility production. The balance between processing efficiency and product quality assurance was addressed during this campaign. Lessons learned from these challenges are applicable to other processing projects.

  4. Stress dependent oxidation of sputtered niobium and effects on superconductivity

    SciTech Connect (OSTI)

    David Henry, M. Wolfley, Steve; Monson, Todd; Clark, Blythe G.; Shaner, Eric; Jarecki, Robert

    2014-02-28

    We report on the suppression of room temperature oxidation of DC sputtered niobium films and the effects upon the superconductive transition temperature, T{sub c}. Niobium was sputter-deposited on silicon dioxide coated 150?mm wafers and permitted to oxidize at room temperature and pressure for up to two years. Resistivity and stress measurements indicate that tensile films greater than 400?MPa resist bulk oxidation with measurements using transmission electron microscope, electron dispersive X-ray spectroscopy, x-ray photoelectric spectroscopy, and secondary ion mass spectrometry confirming this result. Although a surface oxide, Nb{sub 2}O{sub 5}, consumed the top 610?nm, we measure less than 1 at.% oxygen and nitrogen in the bulk of the films after the oxidation period. T{sub c} measurements using a SQUID magnetometer indicate that the tensile films maintained a T{sub c} approaching the dirty superconductive limit of 8.4?K after two years of oxidation while maintaining room temperature sheet resistance. This work demonstrates that control over niobium film stress during deposition can prevent bulk oxidation by limiting the vertical grain boundaries ability to oxidize, prolonging the superconductive properties of sputtered niobium when exposed to atmosphere.

  5. Mixed Oxide Fuel Fabrication Facility

    National Nuclear Security Administration (NNSA)

    0%2A en Mixed Oxide (MOX) Fuel Fabrication Facility http:nnsa.energy.govfieldofficessavannah-river-field-officemixed-oxide-mox-fuel-fabrication-facility

  6. Oxidative Tritium Decontamination System

    DOE Patents [OSTI]

    Gentile, Charles A. , Guttadora, Gregory L. , Parker, John J.

    2006-02-07

    The Oxidative Tritium Decontamination System, OTDS, provides a method and apparatus for reduction of tritium surface contamination on various items. The OTDS employs ozone gas as oxidizing agent to convert elemental tritium to tritium oxide. Tritium oxide vapor and excess ozone gas is purged from the OTDS, for discharge to atmosphere or transport to further process. An effluent stream is subjected to a catalytic process for the decomposition of excess ozone to diatomic oxygen. One of two configurations of the OTDS is employed: dynamic apparatus equipped with agitation mechanism and large volumetric capacity for decontamination of light items, or static apparatus equipped with pressurization and evacuation capability for decontamination of heavier, delicate, and/or valuable items.

  7. Project Profile: High Performance Reduction/Oxidation Metal Oxides for

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

    Thermochemical Energy Storage | Department of Energy Project Profile: High Performance Reduction/Oxidation Metal Oxides for Thermochemical Energy Storage Project Profile: High Performance Reduction/Oxidation Metal Oxides for Thermochemical Energy Storage Sandia National Laboratory Logo Sandia National Lab (Sandia), through the Concentrating Solar Power: Efficiently Leveraging Equilibrium Mechanisms for Engineering New Thermochemical Storage (CSP: ELEMENTS) funding program, is systematically

  8. Metal atom oxidation laser

    DOE Patents [OSTI]

    Jensen, R.J.; Rice, W.W.; Beattie, W.H.

    1975-10-28

    A chemical laser which operates by formation of metal or carbon atoms and reaction of such atoms with a gaseous oxidizer in an optical resonant cavity is described. The lasing species are diatomic or polyatomic in nature and are readily produced by exchange or other abstraction reactions between the metal or carbon atoms and the oxidizer. The lasing molecules may be metal or carbon monohalides or monoxides. (auth)

  9. Metal atom oxidation laser

    DOE Patents [OSTI]

    Jensen, R.J.; Rice, W.W.; Beattie, W.H.

    1975-10-28

    A chemical laser which operates by formation of metal or carbon atoms and reaction of such atoms with a gaseous oxidizer in an optical resonant cavity is described. The lasing species are diatomic or polyatomic in nature and are readily produced by exchange or other abstraction reactions between the metal or carbon atoms and the oxidizer. The lasing molecules may be metal or carbon monohalides or monoxides.

  10. Controlled CO preferential oxidation

    DOE Patents [OSTI]

    Meltser, M.A.; Hoch, M.M.

    1997-06-10

    Method is described for controlling the supply of air to a PROX (PReferential OXidation for CO cleanup) reactor for the preferential oxidation in the presence of hydrogen wherein the concentration of the hydrogen entering and exiting the PROX reactor is monitored, the difference there between correlated to the amount of air needed to minimize such difference, and based thereon the air supply to the PROX reactor adjusted to provide such amount and minimize such difference. 2 figs.

  11. A New Route to Nanoscale Conducting Channels in Insulating Oxides

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

    interacting, electrons could hold the key to engineering novel functionality into a new generation of all-oxide electronic devices. ARPES measurements of a 2DEG in SrTiO3 and...

  12. Size Effect of Ruthenium Nanoparticles in Catalytic Carbon Monoxide Oxidation

    SciTech Connect (OSTI)

    Joo, Sang Hoon; Park, Jeong Y.; Renzas, J. Russell; Butcher, Derek R.; Huang, Wenyu; Somorjai, Gabor A.

    2010-04-04

    Carbon monoxide oxidation over ruthenium catalysts has shown an unusual catalytic behavior. Here we report a particle size effect on CO oxidation over Ru nanoparticle (NP) catalysts. Uniform Ru NPs with a tunable particle size from 2 to 6 nm were synthesized by a polyol reduction of Ru(acac){sub 3} precursor in the presence of poly(vinylpyrrolidone) stabilizer. The measurement of catalytic activity of CO oxidation over two-dimensional Ru NPs arrays under oxidizing reaction conditions (40 Torr CO and 100 Torr O{sub 2}) showed an activity dependence on the Ru NP size. The CO oxidation activity increases with NP size, and the 6 nm Ru NP catalyst shows 8-fold higher activity than the 2 nm catalysts. The results gained from this study will provide the scientific basis for future design of Ru-based oxidation catalysts.

  13. Growth of tungsten oxide on carbon nanowalls templates

    SciTech Connect (OSTI)

    Wang, Hua; Su, Yan; Chen, Shuo; Quan, Xie

    2013-03-15

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

  14. ARM - Measurement - Inorganic chemical composition

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

    govMeasurementsInorganic chemical composition ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Inorganic chemical composition The chemical composition of an aerosol, with the exception of those with hydrocarbons, and usually including carbides, oxides of carbon, metallic carbonates, carbon sulfur compounds, and carbon nitrogen compounds. Categories Aerosols Instruments The above measurement is

  15. Reference electrode for strong oxidizing acid solutions

    DOE Patents [OSTI]

    Rigdon, Lester P.; Harrar, Jackson E.; Bullock, Sr., Jack C.; McGuire, Raymond R.

    1990-01-01

    A reference electrode for the measurement of the oxidation-reduction potentials of solutions is especially suitable for oxidizing solutions such as highly concentrated and fuming nitric acids, the solutions of nitrogen oxides, N.sub.2 O.sub.4 and N.sub.2 O.sub.5, in nitric acids. The reference electrode is fabricated of entirely inert materials, has a half cell of Pt/Ce(IV)/Ce(III)/70 wt. % HNO.sub.3, and includes a double-junction design with an intermediate solution of 70 wt. % HNO.sub.3. The liquid junctions are made from Corning No. 7930 glass for low resistance and negligible solution leakage.

  16. Methanol partial oxidation reformer

    DOE Patents [OSTI]

    Ahmed, S.; Kumar, R.; Krumpelt, M.

    1999-08-24

    A partial oxidation reformer is described comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell. 7 figs.

  17. Methanol partial oxidation reformer

    DOE Patents [OSTI]

    Ahmed, Shabbir; Kumar, Romesh; Krumpelt, Michael

    1999-01-01

    A partial oxidation reformer comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell.

  18. Methanol partial oxidation reformer

    DOE Patents [OSTI]

    Ahmed, S.; Kumar, R.; Krumpelt, M.

    1999-08-17

    A partial oxidation reformer is described comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell. 7 figs.

  19. Methanol partial oxidation reformer

    DOE Patents [OSTI]

    Ahmed, Shabbir; Kumar, Romesh; Krumpelt, Michael

    2001-01-01

    A partial oxidation reformer comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell.

  20. Tape casting of magnesium oxide.

    SciTech Connect (OSTI)

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

    2008-02-01

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

  1. Thermally Oxidized Silicon

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

    4 Anneli Munkholm (Lumileds Lighting) and Sean Brennan (SSRL) Illustration of the silicon positions near the Si-SiO2 interface for a 4° miscut projected onto the ( ) plane. The silicon atoms in the substrate are blue and those in the oxide are red. The small black spots represent the translated silicon positions in the absence of static disorder. The silicon atoms in the oxide have been randomly assigned a magnitude and direction based on the static disorder value at that position in the

  2. Tetraalykylammonium polyoxoanionic oxidation catalysts

    DOE Patents [OSTI]

    Ellis, Paul E. (Downingtown, PA); Lyons, James E. (Wallingford, PA); Myers, Jr., Harry K. (Cochranville, PA); Shaikh, Shahid N. (Media, PA)

    1998-01-01

    Alkanes are catalytically oxidized in air or oxygen using iron-substituted polyoxoanions (POAs) of the formula: H.sub.e-z (n-C.sub.4 H.sub.9).sub.4 N!.sub.z (XM.sub.11 M'O.sub.39).sup.-e The M' (e.g., iron(III)/iron(II)) reduction potential of the POAs is affected by selection of the central atom X and the framework metal M, and by the number of tetrabutyl-ammonium groups. Decreased Fe(III)/Fe(II) reduction potential has been found to correlate to increased oxidation activity.

  3. Tetraalklylammonium polyoxoanionic oxidation catalysts

    DOE Patents [OSTI]

    Ellis, P.E.; Lyons, J.E.; Myers, H.K. Jr.; Shaikh, S.N.

    1998-10-06

    Alkanes are catalytically oxidized in air or oxygen using iron-substituted polyoxoanions (POAs) of the formula: H{sub e{minus}z}[(n-C{sub 4}H{sub 9}){sub 4}N]{sub z}(XM{sub 11}M{prime}O{sub 39}){sup {minus}e}. The M{prime} (e.g., iron(III)/iron(II)) reduction potential of the POAs is affected by selection of the central atom X and the framework metal M, and by the number of tetrabutyl-ammonium groups. Decreased Fe(III)/Fe(II) reduction potential has been found to correlate to increased oxidation activity.

  4. Tetraalykylammonium polyoxoanionic oxidation catalysts

    DOE Patents [OSTI]

    Ellis, Paul E.; Lyons, James E.; Myers, Jr., Harry K.; Shaikh, Shahid N.

    1998-01-01

    Alkanes are catalytically oxidized in air or oxygen using iron-substituted polyoxoanions (POAs) of the formula: H.sub.e-z ›(n-C.sub.4 H.sub.9).sub.4 N!.sub.z (XM.sub.11 M'O.sub.39).sup.-e The M' (e.g., iron(III)/iron(II)) reduction potential of the POAs is affected by selection of the central atom X and the framework metal M, and by the number of tetrabutyl-ammonium groups. Decreased Fe(III)/Fe(II) reduction potential has been found to correlate to increased oxidation activity.

  5. Molecular water oxidation catalyst

    DOE Patents [OSTI]

    Gratzel, Michael; Munavalli, Shekhar; Pern, Fu-Jann; Frank, Arthur J.

    1993-01-01

    A dimeric composition of the formula: ##STR1## wherein L', L", L'", and L"" are each a bidentate ligand having at least one functional substituent, the ligand selected from bipyridine, phenanthroline, 2-phenylpyridine, bipyrimidine, and bipyrazyl and the functional substituent selected from carboxylic acid, ester, amide, halogenide, anhydride, acyl ketone, alkyl ketone, acid chloride, sulfonic acid, phosphonic acid, and nitro and nitroso groups. An electrochemical oxidation process for the production of the above functionally substituted bidentate ligand diaqua oxo-bridged ruthenium dimers and their use as water oxidation catalysts is described.

  6. Elongational viscosity of photo-oxidated LDPE

    SciTech Connect (OSTI)

    Roln-Garrido, Vctor H. E-mail: manfred.wagner@tu-berlin.de; Wagner, Manfred H. E-mail: manfred.wagner@tu-berlin.de

    2014-05-15

    Sheets of low-density polyethylene (LDPE) were photo-oxidatively treated at room temperature, and subsequently characterized rheologically in the melt state by shear and uniaxial extensional experiments. For photo-oxidation, a xenon lamp was used to irradiate the samples for times between 1 day and 6 weeks. Linear-viscoelastic characterization was performed in a temperature range of 130 to 220C to obtain the master curve at 170C, the reference temperature at which the elongational viscosities were measured. Linear viscoelasticity is increasingly affected by increasing photo-oxidation due to crosslinking of LDPE, as corroborated by an increasing gel fraction as determined by a solvent extraction method. The elongational measurements reveal a strong enhancement of strain hardening until a saturation level is achieved. The elongational data are analyzed in the frame work of two constitutive equations, the rubber-like liquid and the molecular stress function models. Within the experimental window, timedeformation separability is confirmed for all samples, independent of the degree of photo-oxidation.

  7. A Porphyrin-Stabilized Iridium Oxide Water Oxidation Catalyst

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

    Authors: Sherman, B. D., Pillai, S., Kodis, G., Bergkamp, J., Mallouk, T. E., Gust, D., Moore, T. A., and Moore, A. L. Title: A Porphyrin-Stabilized Iridium Oxide Water Oxidation...

  8. Shifts in oxidation states of cerium oxide nanoparticles detected inside intact hydrated cells and organelles

    SciTech Connect (OSTI)

    Szymanski, Craig J.; Munusamy, Prabhakaran; Mihai, Cosmin; Xie, Yumei; Hu, Dehong; Gilles, Marry K.; Tyliszczak, T.; Thevuthasan, Suntharampillai; Baer, Donald R.; Orr, Galya

    2015-09-01

    Cerium oxide nanoparticles (CNPs) have been shown to induce diverse biological effects, ranging from toxic to beneficial. The beneficial effects have been attributed to the potential antioxidant activity of CNPs via certain redox reactions, depending on their oxidation state or Ce3+/Ce4+ ratio. However, this ratio is strongly dependent on the environment and age of the nanoparticles and it is unclear whether and how the complex intracellular environment impacts this ratio and the possible redox reactions of CNPs. To identify any changes in the oxidation state of CNPs in the intracellular environment and better understand their intracellular reactions, we directly quantified the oxidation states of CNPs outside and inside intact hydrated cells and organelles using correlated scanning transmission x-ray and super resolution fluorescence microscopies. By analyzing hundreds of small CNP aggregates, we detected a shift to a higher Ce3+/Ce4+ ratio in CNPs inside versus outside the cells, indicating a net reduction of CNPs in the intracellular environment. We further found a similar ratio in the cytoplasm and in the lysosomes, indicating that the net reduction occurs earlier in the internalization pathway. Together with oxidative stress and toxicity measurements, our observations identify a net reduction of CNPs in the intracellular environment, which is consistent with their involvement in potentially beneficial oxidation reactions, but also point to interactions that can negatively impact the health of cells.

  9. Oxidation of Mercury in Products of Coal Combustion

    SciTech Connect (OSTI)

    Peter Walsh; Giang Tong; Neeles Bhopatkar; Thomas Gale; George Blankenship; Conrad Ingram; Selasi Blavo Tesfamariam Mehreteab; Victor Banjoko; Yohannes Ghirmazion; Heng Ban; April Sibley

    2009-09-14

    Laboratory measurements of mercury oxidation during selective catalytic reduction (SCR) of nitric oxide, simulation of pilot-scale measurements of mercury oxidation and adsorption by unburned carbon and fly ash, and synthesis of new materials for simultaneous oxidation and adsorption of mercury, were performed in support of the development of technology for control of mercury emissions from coal-fired boilers and furnaces. Conversion of gas-phase mercury from the elemental state to water-soluble oxidized form (HgCl{sub 2}) enables removal of mercury during wet flue gas desulfurization. The increase in mercury oxidation in a monolithic V{sub 2}O{sub 5}-WO{sub 3}/TiO{sub 2} SCR catalyst with increasing HCl at low levels of HCl (< 10 ppmv) and decrease in mercury oxidation with increasing NH{sub 3}/NO ratio during SCR were consistent with results of previous work by others. The most significant finding of the present work was the inhibition of mercury oxidation in the presence of CO during SCR of NO at low levels of HCl. In the presence of 2 ppmv HCl, expected in combustion products from some Powder River Basin coals, an increase in CO from 0 to 50 ppmv reduced the extent of mercury oxidation from 24 {+-} 3 to 1 {+-} 4%. Further increase in CO to 100 ppmv completely suppressed mercury oxidation. In the presence of 11-12 ppmv HCl, increasing CO from 0 to {approx}120 ppmv reduced mercury oxidation from {approx}70% to 50%. Conversion of SO{sub 2} to sulfate also decreased with increasing NH{sub 3}/NO ratio, but the effects of HCl and CO in flue gas on SO{sub 2} oxidation were unclear. Oxidation and adsorption of mercury by unburned carbon and fly ash enables mercury removal in a particulate control device. A chemical kinetic mechanism consisting of nine homogeneous and heterogeneous reactions for mercury oxidation and removal was developed to interpret pilot-scale measurements of mercury oxidation and adsorption by unburned carbon and fly ash in experiments at pilot

  10. Highly oxidized superconductors

    DOE Patents [OSTI]

    Morris, D.E.

    1994-09-20

    Novel superconducting materials in the form of compounds, structures or phases are formed by performing otherwise known synthesis in a highly oxidizing atmosphere rather than that created by molecular oxygen at atmospheric pressure or below. This leads to the successful synthesis of novel superconducting compounds which are thermodynamically stable at the conditions under which they are formed. 16 figs.

  11. Conformations of organophosphine oxides

    SciTech Connect (OSTI)

    De Silva, Nuwan; Zahariev, Federico; Hay, Benjamin P.; Gordon, Mark S.; Windus, Theresa L.

    2015-07-17

    The conformations of a series of organophosphine oxides, OP(CH3)2R, where R = methyl, ethyl, isopropyl, tert-butyl, vinyl, and phenyl, are predicted using the MP2/cc-pVTZ level of theory. Comparison of potential energy surfaces for rotation about P–C bonds with crystal structure data reveals a strong correlation between predicted location and energetics of minima and histograms of dihedral angle distributions observed in the solid state. In addition, the most stable conformers are those that minimize the extent of steric repulsion between adjacent rotor substituents, and the torsional barriers tend to increase with the steric bulk of the rotating alkyl group. MM3 force field parameters were adjusted to fit the MP2 results, providing a fast and accurate model for predicting organophosphine oxides shapes—an essential part of understanding the chemistry of these compounds. As a result, the predictive power of the modified MM3 model was tested against MP2/cc-pVTZ conformations for triethylphosphine oxide, OP(CH2CH3)3, and triphenylphosphine oxide, OP(Ph)3.

  12. Conformations of organophosphine oxides

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

    De Silva, Nuwan; Zahariev, Federico; Hay, Benjamin P.; Gordon, Mark S.; Windus, Theresa L.

    2015-07-17

    The conformations of a series of organophosphine oxides, OP(CH3)2R, where R = methyl, ethyl, isopropyl, tert-butyl, vinyl, and phenyl, are predicted using the MP2/cc-pVTZ level of theory. Comparison of potential energy surfaces for rotation about P–C bonds with crystal structure data reveals a strong correlation between predicted location and energetics of minima and histograms of dihedral angle distributions observed in the solid state. In addition, the most stable conformers are those that minimize the extent of steric repulsion between adjacent rotor substituents, and the torsional barriers tend to increase with the steric bulk of the rotating alkyl group. MM3 forcemore » field parameters were adjusted to fit the MP2 results, providing a fast and accurate model for predicting organophosphine oxides shapes—an essential part of understanding the chemistry of these compounds. As a result, the predictive power of the modified MM3 model was tested against MP2/cc-pVTZ conformations for triethylphosphine oxide, OP(CH2CH3)3, and triphenylphosphine oxide, OP(Ph)3.« less

  13. Doped zinc oxide microspheres

    DOE Patents [OSTI]

    Arnold, Jr., Wesley D.; Bond, Walter D.; Lauf, Robert J.

    1993-01-01

    A new composition and method of making same for a doped zinc oxide microsphere and articles made therefrom for use in an electrical surge arrestor which has increased solid content, uniform grain size and is in the form of a gel.

  14. Doped zinc oxide microspheres

    DOE Patents [OSTI]

    Arnold, W.D. Jr.; Bond, W.D.; Lauf, R.J.

    1993-12-14

    A new composition and method of making same for a doped zinc oxide microsphere and articles made therefrom for use in an electrical surge arrestor which has increased solid content, uniform grain size and is in the form of a gel. 4 figures.

  15. Highly oxidized superconductors

    DOE Patents [OSTI]

    Morris, Donald E.

    1994-01-01

    Novel superconducting materials in the form of compounds, structures or phases are formed by performing otherwise known syntheses in a highly oxidizing atmosphere rather than that created by molecular oxygen at atmospheric pressure or below. This leads to the successful synthesis of novel superconducting compounds which are thermodynamically stable at the conditions under which they are formed.

  16. Nanostructured transition metal oxides useful for water oxidation catalysis

    DOE Patents [OSTI]

    Frei, Heinz M; Jiao, Feng

    2013-12-24

    The present invention provides for a composition comprising a nanostructured transition metal oxide capable of oxidizing two H.sub.2O molecules to obtain four protons. In some embodiments of the invention, the composition further comprises a porous matrix wherein the nanocluster of the transition metal oxide is embedded on and/or in the porous matrix.

  17. Staged membrane oxidation reactor system

    DOE Patents [OSTI]

    Repasky, John Michael; Carolan, Michael Francis; Stein, VanEric Edward; Chen, Christopher Ming-Poh

    2012-09-11

    Ion transport membrane oxidation system comprising (a) two or more membrane oxidation stages, each stage comprising a reactant zone, an oxidant zone, one or more ion transport membranes separating the reactant zone from the oxidant zone, a reactant gas inlet region, a reactant gas outlet region, an oxidant gas inlet region, and an oxidant gas outlet region; (b) an interstage reactant gas flow path disposed between each pair of membrane oxidation stages and adapted to place the reactant gas outlet region of a first stage of the pair in flow communication with the reactant gas inlet region of a second stage of the pair; and (c) one or more reactant interstage feed gas lines, each line being in flow communication with any interstage reactant gas flow path or with the reactant zone of any membrane oxidation stage receiving interstage reactant gas.

  18. Staged membrane oxidation reactor system

    DOE Patents [OSTI]

    Repasky, John Michael; Carolan, Michael Francis; Stein, VanEric Edward; Chen, Christopher Ming-Poh

    2013-04-16

    Ion transport membrane oxidation system comprising (a) two or more membrane oxidation stages, each stage comprising a reactant zone, an oxidant zone, one or more ion transport membranes separating the reactant zone from the oxidant zone, a reactant gas inlet region, a reactant gas outlet region, an oxidant gas inlet region, and an oxidant gas outlet region; (b) an interstage reactant gas flow path disposed between each pair of membrane oxidation stages and adapted to place the reactant gas outlet region of a first stage of the pair in flow communication with the reactant gas inlet region of a second stage of the pair; and (c) one or more reactant interstage feed gas lines, each line being in flow communication with any interstage reactant gas flow path or with the reactant zone of any membrane oxidation stage receiving interstage reactant gas.

  19. Staged membrane oxidation reactor system

    DOE Patents [OSTI]

    Repasky, John Michael; Carolan, Michael Francis; Stein, VanEric Edward; Chen, Christopher Ming-Poh

    2014-05-20

    Ion transport membrane oxidation system comprising (a) two or more membrane oxidation stages, each stage comprising a reactant zone, an oxidant zone, one or more ion transport membranes separating the reactant zone from the oxidant zone, a reactant gas inlet region, a reactant gas outlet region, an oxidant gas inlet region, and an oxidant gas outlet region; (b) an interstage reactant gas flow path disposed between each pair of membrane oxidation stages and adapted to place the reactant gas outlet region of a first stage of the pair in flow communication with the reactant gas inlet region of a second stage of the pair; and (c) one or more reactant interstage feed gas lines, each line being in flow communication with any interstage reactant gas flow path or with the reactant zone of any membrane oxidation stage receiving interstage reactant gas.

  20. Temperature estimates from zircaloy oxidation kinetics and microstructures. [PWR

    SciTech Connect (OSTI)

    Olsen, C.S.

    1982-10-01

    This report reviews state-of-the-art capability to determine peak zircaloy fuel rod cladding temperatures following an abnormal temperature excursion in a nuclear reactor, based on postirradiation metallographic analysis of zircaloy microstructural and oxidation characteristics. Results of a comprehensive literature search are presented to evaluate the suitability of available zircaloy microstructural and oxidation data for estimating anticipated reactor fuel rod cladding temperatures. Additional oxidation experiments were conducted to evaluate low-temperature zircaloy oxidation characteristics for postirradiation estimation of cladding temperature by metallographic examination. Results of these experiments were used to calculate peak cladding temperatures of electrical heater rods and nuclear fuel rods that had been subjected to reactor temperature transients. Comparison of the calculated and measured peak cladding temperatures for these rods indicates that oxidation kinetics is a viable technique for estimating peak cladding temperatures over a broad temperature range. However, further improvement in zircaloy microstructure technology is necessary for precise estimation of peak cladding temperatures by microstructural examination.

  1. Doped palladium containing oxidation catalysts

    DOE Patents [OSTI]

    Mohajeri, Nahid

    2014-02-18

    A supported oxidation catalyst includes a support having a metal oxide or metal salt, and mixed metal particles thereon. The mixed metal particles include first particles including a palladium compound, and second particles including a precious metal group (PMG) metal or PMG metal compound, wherein the PMG metal is not palladium. The oxidation catalyst may also be used as a gas sensor.

  2. Enzymatic Oxidation of Methane

    SciTech Connect (OSTI)

    Sirajuddin, S; Rosenzweig, AC

    2015-04-14

    Methane monooxygenases (MMOs) are enzymes that catalyze the oxidation of methane to methanol in methanotrophic bacteria. As potential targets for new gas-to-liquid methane bioconversion processes, MMOs have attracted intense attention in recent years. There are two distinct types of MMO, a soluble, cytoplasmic MMO (sMMO) and a membrane-bound, particulate MMO (pMMO). Both oxidize methane at metal centers within a complex, multisubunit scaffold, but the structures, active sites, and chemical mechanisms are completely different. This Current Topic review article focuses on the overall architectures, active site structures, substrate reactivities, proteinprotein interactions, and chemical mechanisms of both MMOs, with an emphasis on fundamental aspects. In addition, recent advances, including new details of interactions between the sMMO components, characterization of sMMO intermediates, and progress toward understanding the pMMO metal centers are highlighted. The work summarized here provides a guide for those interested in exploiting MMOs for biotechnological applications.

  3. Millisecond Oxidation of Alkanes

    Broader source: Energy.gov [DOE]

    This factsheet describes a project whose goal is to commercialize a production process for propylene and acrylic acid from propane using a catalytic auto-thermal oxydehydrogenation process operating at short contact times. Auto-thermal oxidation for conversion of propane to propylene and acrylic acid promises energy savings of 20 trillion Btu per year by 2020. In addition to reducing energy consumption, this technology can reduce manufacturing costs by up to 25 percent, and reduce a variety of greenhouse gas emissions.

  4. Controlled CO preferential oxidation

    DOE Patents [OSTI]

    Meltser, Mark A.; Hoch, Martin M.

    1997-01-01

    Method for controlling the supply of air to a PROX reactor for the preferential oxidation in the presence of hydrogen wherein the concentration of the hydrogen entering and exiting the PROX reactor is monitored, the difference therebetween correlated to the amount of air needed to minimize such difference, and based thereon the air supply to the PROX reactor adjusted to provide such amount and minimize such difference.

  5. Nonisostructural complex oxide heteroepitaxy

    SciTech Connect (OSTI)

    Wong, Franklin J. Ramanathan, Shriram

    2014-07-01

    The authors present an overview of the fundamentals and representative examples of the growth of epitaxial complex oxide thin films on structurally dissimilar substrates. The authors will delineate how the details of particular crystal structures and symmetry of different oxide surfaces can be employed for a rational approach to the synthesis of nonisostructural epitaxial heterostructures. The concept of oxygen eutaxy can be widely applied. Materials combinations will be split into three categories, and in all cases the films and substrates occur in different crystal structures: (1) common translational and rotational symmetry between the film and substrate planes; (2) translational symmetry mismatch between the substrates and films that is distinct from a simple mismatch in lattice parameters; and (3) rotational symmetry mismatch. In case (1), in principle single-crystalline thin films can be attained despite the films and substrates possessing different crystal structures. In case (2), antiphase boundaries will be prevalent in the thin films. In case (3), thin-film rotational variants that are joined by tilt boundaries will be present. Diffraction techniques to determine crystallographic alignment and epitaxial variants are discussed, and transmission electron microscopy studies to investigate extended defects in the thin films will also be reviewed. The authors end with open problems in this field regarding the structure of oxide interfaces that can be topics for future research.

  6. Hysteresis-free high rate reactive sputtering of niobium oxide, tantalum oxide, and aluminum oxide

    SciTech Connect (OSTI)

    Srhammar, Erik, E-mail: erik.sarhammar@angstrom.uu.se; Berg, Sren; Nyberg, Tomas [Department of Solid State Electronics, The ngstrm Laboratory, Uppsala University, Box 534, SE-751 21 Uppsala (Sweden)

    2014-07-01

    This work reports on experimental studies of reactive sputtering from targets consisting of a metal and its oxide. The composition of the targets varied from pure metal to pure oxide of Al, Ta, and Nb. This combines features from both the metal target and oxide target in reactive sputtering. If a certain relation between the metal and oxide parts is chosen, it may be possible to obtain a high deposition rate, due to the metal part, and a hysteresis-free process, due to the oxide part. The aim of this work is to quantify the achievable boost in oxide deposition rate from a hysteresis-free process by using a target consisting of segments of a metal and its oxide. Such an increase has been previously demonstrated for Ti using a homogeneous substoichiometric target. The achievable gain in deposition rate depends on transformation mechanisms from oxide to suboxides due to preferential sputtering of oxygen. Such mechanisms are different for different materials and the achievable gain is therefore material dependent. For the investigated materials, the authors have demonstrated oxide deposition rates that are 1.510 times higher than what is possible from metal targets in compound mode. However, although the principle is demonstrated for oxides of Al, Ta, and Nb, a similar behavior is expected for most oxides.

  7. Measuring Real-time Biological and Abiotic Manganese Oxide Reduction...

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

    Precipitate samples were also retrieved throughout the experiments to analyze with complimentary techniques including x-ray diffraction and Raman spectroscopy. These combined ...

  8. ARM - Measurement -

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

    govMeasurements ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Categories Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. Field Campaign Instruments UV-MFRSR : Ultraviolet

  9. Measurement of $\

    SciTech Connect (OSTI)

    Acciarri, R.; et al.

    2015-11-03

    The ArgoNeuT collaboration reports the first measurement of neutral current $\\pi^{0}$ production in $\

  10. Measuring circuit

    DOE Patents [OSTI]

    Sun, Shan C.; Chaprnka, Anthony G.

    1977-01-11

    An automatic gain control circuit functions to adjust the magnitude of an input signal supplied to a measuring circuit to a level within the dynamic range of the measuring circuit while a log-ratio circuit adjusts the magnitude of the output signal from the measuring circuit to the level of the input signal and optimizes the signal-to-noise ratio performance of the measuring circuit.

  11. PLATES WITH OXIDE INSERTS

    DOE Patents [OSTI]

    West, J.M.; Schumar, J.F.

    1958-06-10

    Planar-type fuel assemblies for nuclear reactors are described, particularly those comprising fuel in the oxide form such as thoria and urania. The fuel assembly consists of a plurality of parallel spaced fuel plate mennbers having their longitudinal side edges attached to two parallel supporting side plates, thereby providing coolant flow channels between the opposite faces of adjacent fuel plates. The fuel plates are comprised of a plurality of longitudinally extending tubular sections connected by web portions, the tubular sections being filled with a plurality of pellets of the fuel material and the pellets being thermally bonded to the inside of the tubular section by lead.

  12. Electrolytic oxide reduction system

    SciTech Connect (OSTI)

    Wiedmeyer, Stanley G; Barnes, Laurel A; Williamson, Mark A; Willit, James L; Berger, John F

    2015-04-28

    An electrolytic oxide reduction system according to a non-limiting embodiment of the present invention may include a plurality of anode assemblies, a plurality of cathode assemblies, and a lift system configured to engage the anode and cathode assemblies. The cathode assemblies may be alternately arranged with the anode assemblies such that each cathode assembly is flanked by two anode assemblies. The lift system may be configured to selectively engage the anode and cathode assemblies so as to allow the simultaneous lifting of any combination of the anode and cathode assemblies (whether adjacent or non-adjacent).

  13. Oxidation resistant alloys, method for producing oxidation resistant alloys

    DOE Patents [OSTI]

    Dunning, John S.; Alman, David E.

    2002-11-05

    A method for producing oxidation-resistant austenitic alloys for use at temperatures below 800 C. comprising of: providing an alloy comprising, by weight %: 14-18% chromium, 15-18% nickel, 1-3% manganese, 1-2% molybdenum, 2-4% silicon, 0% aluminum and the balance being iron; heating the alloy to 800 C. for between 175-250 hours prior to use in order to form a continuous silicon oxide film and another oxide film. The method provides a means of producing stainless steels with superior oxidation resistance at temperatures above 700 C. at a low cost

  14. Selective Oxidation of Organic Substrates to Partially Oxidized...

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

    Technology Brief (243 KB) Technology Marketing Summary Rapid and controlled rate of catalysis, utilizing ozone for oxidation of alcohols to ketones or aldehydes, is made possible...

  15. Oxidation resistant alloys, method for producing oxidation resistant alloys

    DOE Patents [OSTI]

    Dunning, John S.; Alman, David E.

    2002-11-05

    A method for producing oxidation-resistant austenitic alloys for use at temperatures below 800.degree. C. comprising of: providing an alloy comprising, by weight %: 14-18% chromium, 15-18% nickel, 1-3% manganese, 1-2% molybdenum, 2-4% silicon, 0% aluminum and the balance being iron; heating the alloy to 800.degree. C. for between 175-250 hours prior to use in order to form a continuous silicon oxide film and another oxide film. The method provides a means of producing stainless steels with superior oxidation resistance at temperatures above 700.degree. C. at a low cost

  16. PREPARATION OF REFRACTORY OXIDE MICROSPHERE

    DOE Patents [OSTI]

    Haws, C.C. Jr.

    1963-09-24

    A method is described of preparing thorium oxide in the form of fused spherical particles about 1 to 2 microns in diameter. A combustible organic solution of thorium nitrate containing additive metal values is dispersed into a reflected, oxygen-fed flame at a temperature above the melting point of the resulting oxide. The metal additive is aluminum at a proportion such as to provide 1 to 10 weight per cent aluminum oxide in the product, silicon at the same proportion, or beryllium at a proportion of 12 to 25 weight per cent beryllium oxide in the product. A minor proportion of uranium values may also be provided in the solution. The metal additive lowers the oxide melting point and allows fusion and sphere formation in conventional equipment. The product particles are suitable for use in thorium oxide slurries for nuclear reactors. (AEC)

  17. Polaron absorption in amorphous tungsten oxide films

    SciTech Connect (OSTI)

    Berggren, Lars; Azens, Andris; Niklasson, Gunnar A.

    2001-08-15

    Amorphous thin films of tungsten oxide were deposited by sputtering onto glass substrates covered by conductive indium--tin oxide. The density and stoichiometry were determined by Rutherford backscattering spectrometry. Lithium ions were intercalated electrochemically into the films. The optical reflectance and transmittance were measured in the wavelength range from 0.3 to 2.5 {mu}m, at a number of intercalation levels. The polaron absorption peak becomes more symmetric and shifts to higher energies until an intercalation level of 0.25 to 0.3 Li{sup +}/W, where a saturation occurs. The shape of the polaron peak is in very good agreement with the theory of Bryksin [Fiz. Tverd. Tela 24, 1110 (1982)]. Within this model, the shift of the absorption peak is interpreted as an increase in the Fermi level of the material as more Li ions are inserted. {copyright} 2001 American Institute of Physics.

  18. Zinc oxide varistors and/or resistors

    DOE Patents [OSTI]

    Arnold, W.D. Jr.; Bond, W.D.; Lauf, R.J.

    1993-07-27

    Varistors and/or resistors are described that include doped zinc oxide gel microspheres. The doped zinc oxide gel microspheres preferably have from about 60 to about 95% by weight zinc oxide and from about 5 to about 40% by weight dopants based on the weight of the zinc oxide. The dopants are a plurality of dopants selected from silver salts, boron oxide, silicon oxide and hydrons oxides of aluminum, bismuth, cobalt, chromium, manganese, nickel, and antimony.

  19. Zinc oxide varistors and/or resistors

    DOE Patents [OSTI]

    Arnold, Jr., Wesley D.; Bond, Walter D.; Lauf, Robert J.

    1993-01-01

    Varistors and/or resistors that includes doped zinc oxide gel microspheres. The doped zinc oxide gel microspheres preferably have from about 60 to about 95% by weight zinc oxide and from about 5 to about 40% by weight dopants based on the weight of the zinc oxide. The dopants are a plurality of dopants selected from silver salts, boron oxide, silicon oxide and hydrons oxides of aluminum, bismuth, cobalt, chromium, manganese, nickel, and antimony.

  20. Buried oxide layer in silicon

    DOE Patents [OSTI]

    Sadana, Devendra Kumar; Holland, Orin Wayne

    2001-01-01

    A process for forming Silicon-On-Insulator is described incorporating the steps of ion implantation of oxygen into a silicon substrate at elevated temperature, ion implanting oxygen at a temperature below 200.degree. C. at a lower dose to form an amorphous silicon layer, and annealing steps to form a mixture of defective single crystal silicon and polycrystalline silicon or polycrystalline silicon alone and then silicon oxide from the amorphous silicon layer to form a continuous silicon oxide layer below the surface of the silicon substrate to provide an isolated superficial layer of silicon. The invention overcomes the problem of buried isolated islands of silicon oxide forming a discontinuous buried oxide layer.

  1. Continuous lengths of oxide superconductors

    DOE Patents [OSTI]

    Kroeger, Donald M.; List, III, Frederick A.

    2000-01-01

    A layered oxide superconductor prepared by depositing a superconductor precursor powder on a continuous length of a first substrate ribbon. A continuous length of a second substrate ribbon is overlaid on the first substrate ribbon. Sufficient pressure is applied to form a bound layered superconductor precursor powder between the first substrate ribbon and the second substrate ribbon. The layered superconductor precursor is then heat treated to establish the oxide superconducting phase. The layered oxide superconductor has a smooth interface between the substrate and the oxide superconductor.

  2. Measurement Science

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

    wins 2016 Joseph F. Keithley Award for Advances in Measurement Science October 15, 2015 Honors to Albert Migliori, developer of resonant ultrasound spectroscopy LOS ALAMOS, N.M., Oct. 15, 2015-Los Alamos National Laboratory physicist Albert Migliori, having led the development of a powerful tool for important measurements in condensed matter physics including superconductivity, is being given the Joseph F. Keithley Award For Advances in Measurement Science, the top instrumentation prize of the

  3. ARM - Measurements

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

    Measurements Related Links MC3E Home News News & Press MC3E Backgrounder (PDF, 1.61MB) SGP Images ARM flickr site Field Blog ARM Data Discovery Browse Data Deployment Operations Measurements Science Plan (PDF, 3.85 MB) Featured Data Plots SGP Data Plots (all) Experiment Planning Steering Committee Science Questions MC3E Proposal Abstract and Related Campaigns Meetings Cloud Life Cycle Working Group Contacts Michael Jensen, Lead Scientist Measurements Ground-based Instruments Category

  4. ARM - Measurements

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

    Measurements Related Links SPARTICUS Home AAF Home Deployment Operations Measurements SGP Data Plots NASA Data Plots ARM Data Discovery Browse Data Experiment Planning SPARTICUS Proposal Abstract Science Questions Science and Operations (PDF, 1.01M) SPARTICUS Wiki News News & Press Backgrounder (PDF, 269K) Contacts Gerald Mace, Lead Scientist Measurements The SPARTICUS field campaign seeks to collect a substantial series of data sets-profiling cirrus ice crystal size and distribution-during

  5. Valence band offsets of two rare earth oxides on AlxGa1-xN (0≤x≤0...

    Office of Scientific and Technical Information (OSTI)

    earth oxides on AlxGa1-xN (0x0.67) as measured by photoelectron spectroscopy. Citation Details In-Document Search Title: Valence band offsets of two rare earth oxides on ...

  6. Operation of staged membrane oxidation reactor systems

    SciTech Connect (OSTI)

    Repasky, John Michael

    2012-10-16

    A method of operating a multi-stage ion transport membrane oxidation system. The method comprises providing a multi-stage ion transport membrane oxidation system with at least a first membrane oxidation stage and a second membrane oxidation stage, operating the ion transport membrane oxidation system at operating conditions including a characteristic temperature of the first membrane oxidation stage and a characteristic temperature of the second membrane oxidation stage; and controlling the production capacity and/or the product quality by changing the characteristic temperature of the first membrane oxidation stage and/or changing the characteristic temperature of the second membrane oxidation stage.

  7. Effects of Oxidation on Oxidation-Resistant Graphite

    SciTech Connect (OSTI)

    Windes, William; Smith, Rebecca; Carroll, Mark

    2015-05-01

    The Advanced Reactor Technology (ART) Graphite Research and Development Program is investigating doped nuclear graphite grades that exhibit oxidation resistance through the formation of protective oxides on the surface of the graphite material. In the unlikely event of an oxygen ingress accident, graphite components within the VHTR core region are anticipated to oxidize so long as the oxygen continues to enter the hot core region and the core temperatures remain above 400°C. For the most serious air-ingress accident which persists over several hours or days the continued oxidation can result in significant structural damage to the core. Reducing the oxidation rate of the graphite core material during any air-ingress accident would mitigate the structural effects and keep the core intact. Previous air oxidation testing of nuclear-grade graphite doped with varying levels of boron-carbide (B4C) at a nominal 739°C was conducted for a limited number of doped specimens demonstrating a dramatic reduction in oxidation rate for the boronated graphite grade. This report summarizes the conclusions from this small scoping study by determining the effects of oxidation on the mechanical strength resulting from oxidation of boronated and unboronated graphite to a 10% mass loss level. While the B4C additive did reduce mechanical strength loss during oxidation, adding B4C dopants to a level of 3.5% or more reduced the as-fabricated compressive strength nearly 50%. This effectively minimized any benefits realized from the protective film formed on the boronated grades. Future work to infuse different graphite grades with silicon- and boron-doped material as a post-machining conditioning step for nuclear components is discussed as a potential solution for these challenges in this report.

  8. Ultra Supercritical Steamside Oxidation

    SciTech Connect (OSTI)

    Holcomb, Gordon R.; Cramer, Stephen D.; Covino, Bernard S., Jr.; Bullard, Sophie J.; Ziomek-Moroz, Malgorzata

    2005-01-01

    Ultra supercritical (USC) power plants offer the promise of higher efficiencies and lower emissions, which are goals of the U.S. Department of Energy's Advanced Power Systems Initiatives. Most current coal power plants in the U.S. operate at a maximum steam temperature of 538 C. However, new supercritical plants worldwide are being brought into service with steam temperatures of up to 620 C. Current Advanced Power Systems goals include coal generation at 60% efficiency, which require steam temperatures of up to 760 C. This research examines the steamside oxidation of advanced alloys for use in USC systems, with emphasis placed on alloys for high- and intermediate-pressure turbine sections. Initial results of this research are presented.

  9. Complex oxides: Intricate disorder

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

    Uberuaga, Blas Pedro

    2016-02-29

    In this study, complex oxides such as pyrochlores have a myriad of potential technological applications, including as fast ion conductors and radiation-tolerant nuclear waste forms. They are also of interest for their catalytic and spin ice properties. Many of these functional properties are enabled by the atomic structure of the cation sublattices. Pyrochlores (A2B2O7) contain two different cations (A and B), typically a 3+ rare earth and a 4+ transition metal such as Hf, Zr, or Ti. The large variety of chemistries that can form pyrochlores leads to a rich space in which to search for exotic new materials. Furthermore,more » how cations order or disorder on their respective sublattices for a given chemical composition influences the functional properties of the oxide. For example, oxygen ionic conductivity is directly correlated with the level of cation disorder — the swapping of A and B cations1. Further, the resistance of these materials against amorphization has also been connected with the ability of the cations to disorder2, 3. These correlations between cation structure and functionality have spurred great interest in the structure of the cation sublattice under irradiation, with significant focus on the disordering mechanisms and disordered structure. Previous studies have found that, upon irradiation, pyrochlores often undergo an order-to-disorder transformation, in which the resulting structure is, from a diffraction point of view, indistinguishable from fluorite (AO2) (ref. 3). Shamblin et al. now reveal that the structure of disordered pyrochlore is more complicated than previously thought4.« less

  10. Ceramic oxide powders and the formation thereof

    DOE Patents [OSTI]

    Katz, Joseph L.; Hung, Cheng-Hung

    1993-01-01

    Ceramic oxide powders and a method for their preparation. Ceramic oxide powders are obtained using a flame process whereby two or more precursors of ceramic oxides are introduced into a counterflow diffusion flame burner wherein said precursors are converted into ceramic oxide powders. The morphology, particle size, and crystalline form of the ceramic oxide powders are determined by process conditions.

  11. Ceramic oxide powders and the formation thereof

    DOE Patents [OSTI]

    Katz, J.L.; Chenghung Hung.

    1993-12-07

    Ceramic oxide powders and a method for their preparation. Ceramic oxide powders are obtained using a flame process whereby two or more precursors of ceramic oxides are introduced into a counterflow diffusion flame burner wherein said precursors are converted into ceramic oxide powders. The morphology, particle size, and crystalline form of the ceramic oxide powders are determined by process conditions. 14 figures.

  12. Catalysts for low temperature oxidation

    DOE Patents [OSTI]

    Toops, Todd J.; Parks, III, James E.; Bauer, John C.

    2016-03-01

    The invention provides a composite catalyst containing a first component and a second component. The first component contains nanosized gold particles. The second component contains nanosized platinum group metals. The composite catalyst is useful for catalyzing the oxidation of carbon monoxide, hydrocarbons, oxides of nitrogen, and other pollutants at low temperatures.

  13. Metal oxide films on metal

    DOE Patents [OSTI]

    Wu, Xin D. (Los Alamos, NM); Tiwari, Prabhat (Los Alamos, NM)

    1995-01-01

    A structure including a thin film of a conductive alkaline earth metal oxide selected from the group consisting of strontium ruthenium trioxide, calcium ruthenium trioxide, barium ruthenium trioxide, lanthanum-strontium cobalt oxide or mixed alkaline earth ruthenium trioxides thereof upon a thin film of a noble metal such as platinum is provided.

  14. Ethane oxidative dehydrogenation pathways on vanadium oxide catalysts

    SciTech Connect (OSTI)

    Argyle, Morris; Chen, Kaidong; Bell, Alexis T.; Iglesia, Enrique

    2001-12-10

    Kinetic and isotopic tracer and exchange measurements were used to determine the identity and reversibility of elementary steps involved in ethane oxidative dehydrogenation (ODH) on VOx/Al2O3 and VOx/ZrO2. C2H6-C2D6-O2 and C2H6-D2O-O2 react to form alkenes and COx without concurrent formation of C2H6-xDx orC2H4-xDx isotopomers, suggesting that C-H bond cleavage in ethane and ethene is an irreversible and kinetically relevant step in ODH and combustion reactions. Primary ethane ODH reactions show normal kinetic isotopic effects (kC-H/kC-D) 2.4; similar values were measured for ethane and ethene combustion(1.9 and 2.8, respectively). 16O2-18O2-C2H6 reactions on supported V16Ox domains led to the initial appearance of 16O from the lattice in H2O, CO, and CO2, consistent with the involvement of lattice oxygen in C-H bond activation steps. Isotopic contents are similar in H2O, CO, and CO2, suggesting that ODH and combustion reactions use similar lattice oxygen sites. No 16O-18O isotopomer s were detected during reactions of 16O2-18O2-C2H6 mixtures, as expected if dissociative O2 chemisorption steps were irreversible. The alkyl species formed in these steps desorb irreversibly as ethene and the resulting O-H groups recombine to form H2O and reduced V centers in reversible desorption steps. These reduced V centers reoxidize by irreversible dissociative chemisorption of O2. A pseudo-steady state analysis of these elementary steps together with these reversibility assumptions led to a rate expression that accurately describes the observed inhibition of ODH rates by water and the measured kinetic dependence of ODH rates on C2H6 and O2 pressures. This kinetic analysis suggests that surface oxygen, OH groups, and oxygen vacancies are the most abundant reactive intermediates during ethane ODH on active VOx domains.

  15. Ethane oxidative dehydrogenation pathways on vanadium oxide catalysts

    SciTech Connect (OSTI)

    Argyle, Morris; Chen, Kaidong; Bell, Alexis T.; Iglesia, Enrique

    2001-12-10

    Kinetic and isotopic tracer and exchange measurements were used to determine the identity and reversibility of elementary steps involved in ethane oxidative dehydrogenation (ODH) on VOx/Al2O3 and VOx/ZrO2. C2H6-C2D6-O2 and C2H6-D2O-O2 react to form alkenes and COx without concurrent formation of C2H6-xDx orC2H4-xDx isotopomers, suggesting that C-H bond cleavage in ethane and ethene is an irreversible and kinetically relevant step in ODH and combustion reactions. Primary ethane ODH reactions show normal kinetic isotopic effects (kC-H/kC-D 2.4); similar values were measured for ethane and ethene combustion(1.9 and 2.8, respectively). 16O2-18O2-C2H6 reactions on supported V16Ox domains led to the initial appearance of 16O from the lattice in H2O, CO, and CO2, consistent with the involvement of lattice oxygen in C-H bond activation steps. Isotopic contents are similar in H2O, CO, and CO2, suggesting that ODH and combustion reactions use similar lattice oxygen sites. No 16O-18O isotopomer s were detected during reactions of 16O2-18O2-C2H6 mixtures, as expected if dissociative O2 chemisorption steps were irreversible. The alkyl species formed in these steps desorb irreversibly as ethene and the resulting O-H groups recombine to form H2O and reduced V centers in reversible desorption steps. These reduced V centers reoxidize by irreversible dissociative chemisorption of O2. A pseudo-steady state analysis of these elementary steps together with these reversibility assumptions led to a rate expression that accurately describes the observed inhibition of ODH rates by water and the measured kinetic dependence of ODH rates on C2H6 and O2 pressures. This kinetic analysis suggests that surface oxygen, OH groups, and oxygen vacancies are the most abundant reactive intermediates during ethane ODH on active VOx domains.

  16. Self-irradiation and oxidation effects on americium sesquioxide and Raman spectroscopy studies of americium oxides

    SciTech Connect (OSTI)

    Horlait, Denis; Delahaye, Thibaud

    2014-09-15

    Americium oxides samples were characterized by X-ray diffraction (XRD) and Raman spectroscopy, with an emphasis on their structural behavior under oxidation and self-irradiation. Raman spectra of americium dioxide (AmO{sub 2}) and sesquioxide (Am{sub 2}O{sub 3}) were obtained for the first time. With the help of literature data on isostructural oxides, Raman signatures of Ia-3 C-type Am{sub 2}O{sub 3} and P-3m1 A-type Am{sub 2}O{sub 3} are identified. For AmO{sub 2,} a clear band is noted at 390 cm{sup −1}. Its nature is compared to that of the other actinide dioxides. Am{sub 2}O{sub 3} evolution under ambient conditions and against {sup 241}Am α self-irradiation was monitored by powder XRD. The sample, initially composed of A-type Am{sub 2}O{sub 3} as major phase as well as C2/m B-type and C-type structures as minor phases, progressively oxidizes to Fm-3m AmO{sub 2−δ} over a few months. On the basis of diffractogram refinements, evolutions of unit cell volumes caused by self-irradiation are also determined and discussed. - Graphical abstract: The evolution of americium oxide under ambient conditions was monitored using XRD (X-ray diffraction) and Raman spectroscopy. After a thermal treatment under reducing conditions, a polyphasic sample mainly composed of A- and C-type americium sesquioxides is evidenced by XRD and Raman spectroscopy. The sample then evolves through two processes: oxidation and self-irradiation. The first one provokes the progressive appearance of F-type americium dioxide while the initial phases disappear, whereas the main effect of the second is a structural swelling with time. - Highlights: • The first Raman spectroscopy measurements on americium oxides were performed. • Observed Am{sub 2}O{sub 3} Raman bands were identified thanks to data on analogue compounds. • AmO{sub 2} assumed T{sub 2g} band presents a shift compared to the actinide dioxide series. • Am{sub 2}O{sub 3} evolution under self-irradiation and oxidation was also

  17. Graphene oxide as a photocatalytic material

    SciTech Connect (OSTI)

    Krishnamoorthy, Karthikeyan; Mohan, Rajneesh; Kim, S.-J.

    2011-06-13

    The photocatalytic characteristics of graphene oxide (GO) nanostructures synthesized by modified Hummer's method were investigated by measuring reduction rate of resazurin (RZ) into resorufin (RF) as a function of UV irradiation time. The progress of the photocatalytic reaction was monitored by change in color from blue (RZ) into pink (RF) followed by absorption spectra. It exhibited excellent photocatalytic activity, leading to the reduction of RZ in UV irradiation. The fitting of absorbance maximum versus time suggests that the reduction of RZ follow the pseudo first-order reaction kinetics. These results indicate that GO have great potential for use as a photocatalyst.

  18. MEASURING PROJECTOR

    DOE Patents [OSTI]

    Franck, J.V.; Broadhead, P.S.; Skiff, E.W.

    1959-07-14

    A semiautomatic measuring projector particularly adapted for measurement of the coordinates of photographic images of particle tracks as prcduced in a bubble or cloud chamber is presented. A viewing screen aids the operator in selecting a particle track for measurement. After approximate manual alignment, an image scanning system coupled to a servo control provides automatic exact alignment of a track image with a reference point. The apparatus can follow along a track with a continuous motion while recording coordinate data at various selected points along the track. The coordinate data is recorded on punched cards for subsequent computer calculation of particle trajectory, momentum, etc.

  19. Ethanol oxidation on metal oxide-supported platinum catalysts

    SciTech Connect (OSTI)

    L. M. Petkovic 090468; Sergey N. Rashkeev; D. M. Ginosar

    2009-09-01

    Ethanol is a renewable fuel that can be used as an additive to gasoline (or its substitute) with the advantage of octane enhancement and reduced carbon monoxide exhaust emissions. However, on Ethanol is a renewable fuel that can be used as an additive to gasoline (or its substitute) with the advantage of octane enhancement and reduced carbon monoxide exhaust emissions. However, on the standard three-way catalysts, the conversion of unburned ethanol is low because both ethanol and some of its partially oxidized derivatives are highly resistant to oxidation. A combination of first-principles density-functional theory (DFT) based calculations and in-situ diffuse reflectance infrared spectroscopy (DRIFTS) analysis was applied to uncover some of the fundamental phenomena associated with ethanol oxidation on Pt containing catalysts. In particular, the objective was to analyze the role of the oxide (i.e., ?-Al2O3 or SiO2) substrate on the ethanol oxidation activity. The results showed that Pt nanoparticles trap and accumulate oxygen at their surface and perimeter sites and play the role of stoves that burn ethanol molecules and their partially oxidized derivatives to the final products. The ?-Al2O3 surfaces provided higher mobility of the fragments of ethanol molecules than the SiO2 surface and hence increased the supply rate of these objects to the Pt particles. This will in turn produce a higher conversion rate of unburned ethanol.and some of its partially oxidized derivatives are highly resistant to oxidation. A combination of first-principles density-functional theory (DFT) based calculations and in-situ diffuse reflectance infrared spectroscopy (DRIFTS) analysis was applied to uncover some of the fundamental phenomena associated with ethanol oxidation on Pt containing catalysts. In particular, the objective was to analyze the role of the oxide (i.e., ?-Al2O3 or SiO2) substrate on the ethanol oxidation activity. The results showed that Pt nanoparticles trap and

  20. MEASURING CIRCUIT

    DOE Patents [OSTI]

    Mahoney, J.R.

    1963-01-29

    A measuring and balancing arrangement for mass spectrometers permits the ready determination of isotopic ratios and mole and weight percentages by employing a selection of amplifier input resistors to vary sensitivity in a bridge arrangement. (AEC)

  1. Measuring Radiation

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

    Measurement Activity SI Units and Prefixes Conversions Safety Around Radiation Sources Types of Radiation Exposure Managing Radiation Emergencies Procedure Demonstration Measurement Activity: How Much Is Present? The size or weight of a container or shipment does not indicate how much radioactivity is in it. The amount of radioactivity in a quantity of material can be determined by noting how many curies of the material are present. This information should be found on labels and/or shipping

  2. ARM - Measurements

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

    Project (BBOP)Measurements Related Links BBOP Home Outreach News & Press Backgrounder (PDF, 2.1MB) Images ARM flickr site ARM Data Discovery Browse Data Deployment Operations Airborne Measurements Science Plan (PDF, 2.2MB) BBOP wiki Login Required Data Sets Experiment Planning Proposal Abstract and Related Campaigns BBOP Breakout Session, ASR Science Team Meeting, March 2014 BBOP Breakout Session, ASR Science Team Meeting, March 2013 BNL BBOP Website Contacts Larry Kleinman, Lead Scientist

  3. ARM - Measurements

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

    Measurements Related Links RACORO Home AAF Home ARM Data Discovery Browse Data Post-Campaign Data Sets Data Guide (PDF, 1.4MB) Campaign Journal Flight Details Images ARM flickr site Deployment Operations Measurements Science & Operations Plan (PDF, 640K) SGP Data Plots RACORO wiki Login Required Experiment Planning Steering Committee Science Questions RACORO Proposal Abstract Full Proposal (PDF, 886K) Collaborations Meetings CLOWD Working Group News Discovery Channel Earth Live Blog News

  4. ARM - Measurements

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

    Measurements Related Links TCAP Home Outreach News & Press WCAI Interview with Dr. Berg (YouTube) Frequently Asked Questions Brochure Backgrounder (PDF, 1.5MB) AMF Poster, 2012 Images ARM flickr site ARM Data Discovery Browse Data Deployment Operations Data Sets Baseline Instruments and Data Plots at the Archive Airborne Measurements Airborne Data Sets Science Plan (PDF, 1.6 MB) G-1 Cabin Layout TCAP wiki Login Required Experiment Planning Proposal Abstract and Related Campaigns Poster at

  5. Higher Americium Oxidation State Research Roadmap (Technical...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Higher Americium Oxidation State Research Roadmap Citation Details In-Document Search Title: Higher Americium Oxidation State Research Roadmap The partitioning of ...

  6. Experimental Approach to Controllably Vary Protein Oxidation...

    Office of Scientific and Technical Information (OSTI)

    Vary Protein Oxidation While Minimizing Electrode Adsorption for Boron-Doped Diamond ... Vary Protein Oxidation While Minimizing Electrode Adsorption for Boron-Doped Diamond ...

  7. Controlling proton movement: electrocatalytic oxidation of hydrogen...

    Office of Scientific and Technical Information (OSTI)

    oxidation of hydrogen by a nickel( ii ) complex containing proton relays in the second ... oxidation of hydrogen by a nickel( ii ) complex containing proton relays in the second ...

  8. Transparent Conducting Oxide - Energy Innovation Portal

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

    ... dielectric permittivity when produced as an oxide, such as materials comprising certain metals, rare earth elements, and lathanides, and the oxides of these elements. ...

  9. NETL: Solid Oxide Fuel Cells Publications

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

    Solid Oxide Fuel Cells Publications This page provides links to SOFC Program related documents and reference materials. SOFC-logo Solid Oxide Fuel Cells Program 2016 Project ...

  10. Precise Application of Transparent Conductive Oxide Coatings...

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

    Precise Application of Transparent Conductive Oxide Coatings for Flat Panel Displays and Photovoltaic Cells Technology available for licensing: New transparent conducting oxide ...

  11. Manganese Oxide Composite Electrodes for Lithium Batteries |...

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

    Manganese Oxide Composite Electrodes for Lithium Batteries Technology available for licensing: Improved spinel-containing "layered-layered" lithium metal oxide electrodes Materials ...

  12. New manganese catalyst for light alkane oxidation

    DOE Patents [OSTI]

    Durante, Vincent A.; Lyons, James E.; Walker, Darrell W.; Marcus, Bonita K.

    1994-01-01

    Aluminophosphates containing manganese in the structural framework are employed for the oxidation of alkanes, for example the vapor phase oxidation of methane to methanol.

  13. Nanostructured Water Oxidation Catalysts - Energy Innovation...

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

    Find More Like This Return to Search Nanostructured Water Oxidation Catalysts Lawrence ... Berkeley Lab have developed a visible light driven catalytic system for oxidizing water. ...

  14. Mixed oxide fuel development

    SciTech Connect (OSTI)

    Leggett, R.D.; Omberg, R.P.

    1987-05-08

    This paper describes the success of the ongoing mixed-oxide fuel development program in the United States aimed at qualifying an economical fuel system for liquid metal cooled reactors. This development has been the cornerstone of the US program for the past 20 years and has proceeded in a deliberate and highly disciplined fashion with high emphasis on fuel reliability and operational safety as major features of an economical fuel system. The program progresses from feature testing in EBR-II to qualifying full size components in FFTF under fully prototypic conditions to establish a basis for extending allowable lifetimes. The development program started with the one year (300 EFPD) core, which is the FFTF driver fuel, continued with the demonstration of a two year (600 EFPD) core and is presently evaluating a three year (900 EFPD) fuel system. All three of these systems, consistent with other LMR fuel programs around the world, use fuel pellets gas bonded to a cladding tube that is assembled into a bundle and fitted into a wrapper tube or duct for ease of insertion into a core. The materials of construction progressed from austenitic CW 316 SS to lower swelling austenitic D9 to non swelling ferritic/martensitic HT9. 6 figs., 2 tabs.

  15. Electronically conductive ceramics for high temperature oxidizing environments

    DOE Patents [OSTI]

    Kucera, Gene H. (Downers Grove, IL); Smith, James L. (Lemont, IL); Sim, James W. (Evergreen Park, IL)

    1986-01-01

    A high temperature, ceramic composition having electronic conductivity as measured by resistivity below about 500 ohm-cm, chemical stability particularly with respect to cathode conditions in a molten carbonate fuel cell, and composed of an alkali metal, transition metal oxide containing a dopant metal in the crystalline structure to replace a portion of the alkali metal or transition metal.

  16. Interfacial electron transfer dynamics of photosensitized zinc oxide nanoclusters

    SciTech Connect (OSTI)

    Murakoshi, Kei; Yanagida, Shozo; Capel, M.

    1997-06-01

    The authors have prepared and characterized photosensitized zinc oxide (ZnO) nanoclusters, dispersed in methanol, using carboxylated coumarin dyes for surface adsorption. Femtosecond time-resolved emission spectroscopy allows the authors to measure the photo-induced charge carrier injection rate constant from the adsorbed photosensitizer to the n-type semiconductor nanocluster. These results are compared with other photosensitized semiconductors.

  17. Investigation of Mixed Oxide Catalysts for NO Oxidation

    SciTech Connect (OSTI)

    Szanyi, Janos; Karim, Ayman M.; Pederson, Larry R.; Kwak, Ja Hun; Mei, Donghai; Tran, Diana N.; Herling, Darrell R.; Muntean, George G.; Peden, Charles HF; Howden, Ken; Qi, Gongshin; Li, Wei

    2014-12-09

    The oxidation of engine-generated NO to NO2 is an important step in the reduction of NOx in lean engine exhaust because NO2 is required for the performance of the LNT technology [2], and it enhances the activities of ammonia selective catalytic reduction (SCR) catalysts [1]. In particular, for SCR catalysts an NO:NO2 ratio of 1:1 is most effective for NOx reduction, whereas for LNT catalysts, NO must be oxidized to NO2 before adsorption on the storage components. However, NO2 typically constitutes less than 10% of NOx in lean exhaust, so catalytic oxidation of NO is essential. Platinum has been found to be especially active for NO oxidation, and is widely used in DOC and LNT catalysts. However, because of the high cost and poor thermal durability of Pt-based catalysts, there is substantial interest in the development of alternatives. The objective of this project, in collaboration with partner General Motors, is to develop mixed metal oxide catalysts for NO oxidation, enabling lower precious metal usage in emission control systems. [1] M. Koebel, G. Madia, and M. Elsener, Catalysis Today 73, 239 (2002). [2] C. H. Kim, G. S. Qi, K. Dahlberg, and W. Li, Science 327, 1624 (2010).

  18. On-board Measurement of NO and NO2 using Non-dispersive Ultraviolet...

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

    More Documents & Publications On-Board Measurement of Ammonia and Nitrous Oxide Using Feedback Absorption Laser Spectroscopy Combined with Amplified Resonance and Low Pressure ...

  19. Oxides having high energy densities

    DOE Patents [OSTI]

    Ceder, Gerbrand; Kang, Kisuk

    2013-09-10

    Certain disclosed embodiments generally relate to oxide materials having relatively high energy and/or power densities. Various aspects of the embodiments are directed to oxide materials having a structure B.sub.i(M.sub.jY.sub.k)O.sub.2, for example, a structure Li.sub.j(Ni.sub.jY.sub.k)O.sub.2 such as Li(Ni.sub.0.5Mn.sub.0.5)O.sub.2. In this structure, Y represents one or more atoms, each independently selected from the group consisting of alkaline earth metals, transition metals, Group 14 elements, Group 15, or Group 16 elements. In some embodiments, such an oxide material may have an O3 crystal structure, and/or a layered structure such that the oxide comprises a plurality of first, repeating atomic planes comprising Li, and a plurality of second, repeating atomic planes comprising Ni and/or Y.

  20. Solid Oxide Fuel Cells FAQs

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

    SOLID OXIDE FUEL CELLS - BASICS Q: What is a fuel cell? A: A fuel cell is a power generation ... Program research is focused on developing low-cost and highly efficient SOFC power ...

  1. Nanostructured Metal Oxide Anodes (Presentation)

    SciTech Connect (OSTI)

    Dillon, A. C.; Riley, L. A.; Lee, S.-H.; Kim, Y.-H.; Ban, C.; Gillaspie, D. T.; Pesaran, A.

    2009-05-01

    This summarizes NREL's FY09 battery materials research activity in developing metal oxide nanostructured anodes to enable high-energy, durable and affordable li-ion batteries for HEVs and PHEVs.

  2. Millisecond Oxidation of Alkanes

    SciTech Connect (OSTI)

    Scott Han

    2011-09-30

    This project was undertaken in response to the Department of Energy's call to research and develop technologies 'that will reduce energy consumption, enhance economic competitiveness, and reduce environmental impacts of the domestic chemical industry.' The current technology at the time for producing 140 billion pounds per year of propylene from naphtha and Liquified Petroleum Gas (LPG) relied on energy- and capital-intensive steam crackers and Fluidized Catalytic Cracking (FCC) units. The propylene is isolated from the product stream in a costly separation step and subsequently converted to acrylic acid and other derivatives in separate production facilities. This project proposed a Short Contact Time Reactor (SCTR)-based catalytic oxydehydrogenation process that could convert propane to propylene and acrylic acid in a cost-effective and energy-efficient fashion. Full implementation of this technology could lead to sizeable energy, economic and environmental benefits for the U. S. chemical industry by providing up to 45 trillion BTUs/year, cost savings of $1.8 billion/year and a combined 35 million pounds/year reduction in environmental pollutants such as COx, NOx, and SOx. Midway through the project term, the program directive changed, which approval from the DOE and its review panel, from direct propane oxidation to acrylic acid at millisecond contact times to a two-step process for making acrylic acid from propane. The first step was the primary focus, namely the conversion of propane to propylene in high yields assisted by the presence of CO2. The product stream from step one was then to be fed directly into a commercially practiced propylene-to-acrylic acid tandem reactor system.

  3. Corporate Performance Measures Definitions

    Broader source: Energy.gov [DOE]

    Plutonium Metal or Oxide packaged for long-term storage (number of containers): Certified DOE storage/treatment/disposal (STD) 3013 containers (or equivalent) of plutonium metal or oxide packaged...

  4. High pressure effects on the iron iron oxide and nickel nickel...

    Office of Scientific and Technical Information (OSTI)

    and volume difference between the metal-oxide pairs Fe-FeO and Ni-NiO were measured using synchrotron X-ray diffraction in a multi-anvil press and laser heated diamond anvil cells. ...

  5. THERMAL EXPANSION AND PHASE INVERSION OF RARE-EARTH OXIDES (Technical...

    Office of Scientific and Technical Information (OSTI)

    Thermal expansion and phase inversion measurements are reported on oxides of Sc, Y, La, and 12 lanthanide series elements up to 1350 deg C. (J.R.D.) Authors: Stecura, S. ; Campbell...

  6. Synergistic interaction between oxides of copper and iron for production of fatty alcohols from fatty acids

    SciTech Connect (OSTI)

    Kandel, Kapil; Chaudhary, Umesh; Nelson, Nicholas C.; Slowing, Igor I.

    2015-10-08

    In this study, the selective hydrogenation of fatty acids to fatty alcohols can be achieved under moderate conditions (180 °C, 30 bar H2) by simultaneously supporting copper and iron oxides on mesoporous silica nanoparticles. The activity of the cosupported oxides is significantly higher than that of each supported metal oxide and of a physical mixture of both individually supported metal oxides. A strong interaction between both metal oxides is evident from dispersion, XRD, TPR, and acetic acid TPD measurements, which is likely responsible for the synergistic behavior of the catalyst. Copper oxide is reduced in situ to its metallic form and thereby activates hydrogen.

  7. Synergistic interaction between oxides of copper and iron for production of fatty alcohols from fatty acids

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

    Kandel, Kapil; Chaudhary, Umesh; Nelson, Nicholas C.; Slowing, Igor I.

    2015-10-08

    In this study, the selective hydrogenation of fatty acids to fatty alcohols can be achieved under moderate conditions (180 °C, 30 bar H2) by simultaneously supporting copper and iron oxides on mesoporous silica nanoparticles. The activity of the cosupported oxides is significantly higher than that of each supported metal oxide and of a physical mixture of both individually supported metal oxides. A strong interaction between both metal oxides is evident from dispersion, XRD, TPR, and acetic acid TPD measurements, which is likely responsible for the synergistic behavior of the catalyst. Copper oxide is reduced in situ to its metallic formmore » and thereby activates hydrogen.« less

  8. Thin film hydrous metal oxide catalysts

    DOE Patents [OSTI]

    Dosch, Robert G. (Albuquerque, NM); Stephens, Howard P. (Albuquerque, NM)

    1995-01-01

    Thin film (<100 nm) hydrous metal oxide catalysts are prepared by 1) synthesis of a hydrous metal oxide, 2) deposition of the hydrous metal oxide upon an inert support surface, 3) ion exchange with catalytically active metals, and 4) activating the hydrous metal oxide catalysts.

  9. Metal oxide nanostructures with hierarchical morphology

    DOE Patents [OSTI]

    Ren, Zhifeng; Lao, Jing Yu; Banerjee, Debasish

    2007-11-13

    The present invention relates generally to metal oxide materials with varied symmetrical nanostructure morphologies. In particular, the present invention provides metal oxide materials comprising one or more metallic oxides with three-dimensionally ordered nanostructural morphologies, including hierarchical morphologies. The present invention also provides methods for producing such metal oxide materials.

  10. Structure of graphene oxide dispersed with ZnO nanoparticles

    SciTech Connect (OSTI)

    Yadav, Rishikesh Pandey, Devendra K.; Khare, P. S.

    2014-10-15

    Graphene has been proposed as a promising two-dimensional nanomaterial with outstanding electronic, optical, thermal and mechanical properties for many applications. In present work a process of dispersion of graphene oxide with ZnO nanoparticles in ethanol solution with different pH values, have been studied. Samples have been characterized by XRD, SEM, PL, UV-visible spectroscopy and particles size measurement. The results analysis indicates overall improved emission spectrum. It has been observed that the average diameter of RGO (Reduced Graphene Oxide) decreases in presence of ZnO nanoparticles from 3.8?m to 0.41?m.

  11. Impact of Biodiesel on the Oxidation Kinetics and Morphology of Diesel Particulate

    SciTech Connect (OSTI)

    Strzelec, Andrea; Toops, Todd J; Daw, C Stuart

    2011-01-01

    We compare the oxidation characteristics of four different diesel particulates generated with a modern light-duty engine. The four particulates represent engine fueling with conventional ultra-low sulfur diesel (ULSD), biodiesel, and two intermediate blends of these fuels. The comparisons discussed here are based on complementary measurements implemented in a laboratory micro-reactor, including temperature programmed desorption and oxidation, pulsed isothermal oxidation, and BET surface area. From these measurements we have derived models that are consistent with the observed oxidation reactivity differences. When accessible surface area effects are properly accounted for, the oxidation kinetics of the fixed carbon components were found to consistently exhibit an Arrhenius activation energy of 113 6 kJ/mol. Release of volatile carbon from the as-collected particulate appears to follow a temperaturedependent rate law.

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

    SciTech Connect (OSTI)

    KAPLAN, DANIEL

    2005-09-13

    repository environments on Pu oxidation state distributions has been the subject of much recent research. Kenney-Kennicutt and Morse (14), Duff et al. (15), and Morgenstern and Choppin (16) observed oxidation of Pu facilitated by Mn(IV)-bearing minerals. Conversely, Shaughnessy et al. (17) used X-ray Absorption near-edge spectroscopy (XANES) to show reduction of Pu(VI) by hausmannite (Mn{sup II}Mn{sub 2}{sup III}O{sub 4}) and manganite ({gamma}-Mn{sup III}OOH) and Kersting et al., (18) observed reduction of Pu(VI) by pyrolusite (Mn{sup IV}O{sub 2}). In this paper, we attempt to reconcile the apparently conflicting datasets by showing that Mn-bearing minerals can indeed oxidize Pu, however, if the oxidized species remains on the solid phase, the oxidation step competes with the formation of Pu(IV) that becomes the predominant solid phase Pu species with time. The experimental approach we took was to conduct longer term (approximately two years later) oxidation state analyses on the Pu sorbed to Yucca Mountain tuff (initial analysis reported by Duff et al., (15)) and measure the time-dependant changes in the oxidation state distribution of Pu in the presence of the Mn mineral pyrolusite.

  13. Nitrous oxide production and methane oxidation by different ammonia-oxidizing bacteria

    SciTech Connect (OSTI)

    Jiang, Q.Q.; Bakken, L.R.

    1999-06-01

    Ammonia-oxidizing bacteria (AOB) are thought to contribute significantly to N{sub 2}O production and methane oxidation in soils. Most knowledge derives from experiments with Nitrosomonas europaea, which appears to be of minor importance in most soils compared to Nitrosospira spp. The authors have conducted a comparative study of levels of aerobic N{sub 2}O production in six phylogenetically different Nitrosospira strains newly isolated from soils and in two N. europaea and Nitrosospira multiformis type strains. The fraction of oxidized ammonium released as N{sub 2}O during aerobic growth was remarkably constant for all the Nitrosospira strains, irrespective of the substrate supply (urea versus ammonium), the pH, or substrate limitation. N. europaea and Nitrosospira multiformis released similar fractions of N{sub 2}O when they were supplied with ample amounts of substrates, but the fractions rose sharply when they were restricted by a low pH or substrate limitation. Phosphate buffer doubled the N{sub 2}O release for all types of AOB. No detectable oxidation of atmospheric methane was detected. Calculations based on detection limits as well as data in the literature on CH{sub 4} oxidation by AOB bacteria prove that none of the tested strains contribute significantly to the oxidation of atmospheric CH{sub 4} in soils.

  14. CO oxidation on gold-supported iron oxides: New insights into strong oxidemetal interactions

    SciTech Connect (OSTI)

    Yu, Liang; Liu, Yun; Yang, Fan; Evans, Jaime; Rodriguez, Jos A.; Liu, Ping

    2015-07-14

    Very active FeOxAu catalysts for CO oxidation are obtained after depositing nanoparticles of FeO, Fe3O4, and Fe2O3 on a Au(111) substrate. Neither FeO nor Fe2O3 is stable under the reaction conditions. Under an environment of CO/O2, they undergo oxidation (FeO) or reduction (Fe2O3) to yield nanoparticles of Fe3O4 that are not formed in a bulk phase. Using a combined experimental and theoretical approach, we show a strong oxidemetal interaction (SOMI) between Fe3O4 nanostructures and Au(111), which gives the oxide special properties, allows the formation of an active phase, and provides a unique interface to facilitate a catalytic reaction. This work highlights the important role that the SOMI can play in enhancing the catalytic performance of the oxide component in metaloxide catalysts.

  15. Measurement of $\

    SciTech Connect (OSTI)

    Aguilar-Arevalo, A.A.; Anderson, C.E.; Bazarko, A.O.; Brice, S.J.; Brown, B.C.; Bugel, L.; Cao, J.; Coney, L.; Conrad, J.M.; Cox, D.C.; Curioni, A.; /Yale U. /Columbia U.

    2010-10-01

    MiniBooNE reports the first absolute cross sections for neutral current single {pi}{sup 0} production on CH{sub 2} induced by neutrino and antineutrino interactions measured from the largest sets of NC {pi}{sup 0} events collected to date. The principal result consists of differential cross sections measured as functions of {pi}{sup 0} momentum and {pi}{sup 0} angle averaged over the neutrino flux at MiniBooNE. We find total cross sections of (4.76 {+-} 0.05{sub stat} {+-} 0.76{sub sys}) x 10{sup -40} cm{sup 2}/nucleon at a mean energy of E{sub {nu}} = 808 MeV and (1.48 {+-} 0.05{sub stat} {+-} 0.23{sub sys}) x 10{sup -40} cm{sup 2}/nucleon at a mean energy of E{sub {nu}} = 664 MeV for {nu}{sub {mu}} and {bar {nu}}{sub {mu}} induced production, respectively. In addition, we have included measurements of the neutrino and antineutrino total cross sections for incoherent exclusive NC 1{pi}{sup 0} production corrected for the effects of final state interactions to compare to prior results.

  16. Mesoporous metal oxide graphene nanocomposite materials

    DOE Patents [OSTI]

    Liu, Jun; Aksay, Ilhan A.; Kou, Rong; Wang, Donghai

    2016-05-24

    A nanocomposite material formed of graphene and a mesoporous metal oxide having a demonstrated specific capacity of more than 200 F/g with particular utility when employed in supercapacitor applications. A method for making these nanocomposite materials by first forming a mixture of graphene, a surfactant, and a metal oxide precursor, precipitating the metal oxide precursor with the surfactant from the mixture to form a mesoporous metal oxide. The mesoporous metal oxide is then deposited onto a surface of the graphene.

  17. Method for plating with metal oxides

    DOE Patents [OSTI]

    Silver, Gary L.; Martin, Frank S.

    1994-08-23

    A method of plating hydrous metal oxides on at least one substrate, which method is indifferent to the electrochemical properties of the substrate, and comprises reacting metallic ions in aqueous solution with an appropriate oxidizing agent such as sodium hypochlorite or calcium sulfite with oxygen under suitable conditions of pH and concentration such that oxidation and precipitation of metal oxide are sufficiently slow to allow satisfactory plating of metal oxide on the substrate.

  18. Method for plating with metal oxides

    DOE Patents [OSTI]

    Silver, G.L.; Martin, F.S.

    1994-08-23

    A method is disclosed of plating hydrous metal oxides on at least one substrate, which method is indifferent to the electrochemical properties of the substrate, and comprises reacting metallic ions in aqueous solution with an appropriate oxidizing agent such as sodium hypochlorite or calcium sulfite with oxygen under suitable conditions of pH and concentration such that oxidation and precipitation of metal oxide are sufficiently slow to allow satisfactory plating of metal oxide on the substrate. 1 fig.

  19. Transparent conducting oxides and production thereof

    DOE Patents [OSTI]

    Gessert, Timothy A.; Yoshida, Yuki; Coutts, Timothy J.

    2014-06-10

    Transparent conducting oxides and production thereof are disclosed. An exemplary method of producing a transparent conducting oxide (TCO) material may comprise: providing a TCO target doped with either a high-permittivity oxide or a low-permittivity oxide in a process chamber. The method may also comprise depositing a metal oxide on the target in the process chamber to form a thin film having enhanced optical properties without substantially decreasing electrical quality.

  20. Transparent conducting oxides and production thereof

    DOE Patents [OSTI]

    Gessert, Timothy A; Yoshida, Yuki; Coutts, Timothy J

    2014-05-27

    Transparent conducting oxides and production thereof are disclosed. An exemplary method of producing a transparent conducting oxide (TCO) material may comprise: providing a TCO target (110) doped with either a high-permittivity oxide or a low-permittivity oxide in a process chamber (100). The method may also comprise depositing a metal oxide on the target (110) to form a thin film having enhanced optical properties without substantially decreasing electrical quality.

  1. Solid oxide electrochemical reactor science.

    SciTech Connect (OSTI)

    Sullivan, Neal P.; Stechel, Ellen Beth; Moyer, Connor J.; Ambrosini, Andrea; Key, Robert J.

    2010-09-01

    Solid-oxide electrochemical cells are an exciting new technology. Development of solid-oxide cells (SOCs) has advanced considerable in recent years and continues to progress rapidly. This thesis studies several aspects of SOCs and contributes useful information to their continued development. This LDRD involved a collaboration between Sandia and the Colorado School of Mines (CSM) ins solid-oxide electrochemical reactors targeted at solid oxide electrolyzer cells (SOEC), which are the reverse of solid-oxide fuel cells (SOFC). SOECs complement Sandia's efforts in thermochemical production of alternative fuels. An SOEC technology would co-electrolyze carbon dioxide (CO{sub 2}) with steam at temperatures around 800 C to form synthesis gas (H{sub 2} and CO), which forms the building blocks for a petrochemical substitutes that can be used to power vehicles or in distributed energy platforms. The effort described here concentrates on research concerning catalytic chemistry, charge-transfer chemistry, and optimal cell-architecture. technical scope included computational modeling, materials development, and experimental evaluation. The project engaged the Colorado Fuel Cell Center at CSM through the support of a graduate student (Connor Moyer) at CSM and his advisors (Profs. Robert Kee and Neal Sullivan) in collaboration with Sandia.

  2. Oxidation behaviour of uranium and neptunium in stabilised zirconia

    SciTech Connect (OSTI)

    Walter, Marcus; Somers, Joseph; Bouexiere, Daniel; Gaczynski, Piotr; Brendebach, Boris

    2009-12-15

    Yttria stabilised zirconia (YSZ) based (Zr,Y,U)O{sub 2-x} and (Zr,Y,Np)O{sub 2-x} solid solutions with 6 and 20 mol% actinide were prepared with Y/Zr ratios ranging from 0.2 to 2.0 to investigate uranium and neptunium oxidation behaviour depending on the oxygen vacancies in the defect fluorite lattice. Sintering at 1600 deg. C in Ar/H{sub 2} yields a cubic, fluorite-type structure with U(IV) and Np(IV). Annealing (Zr,Y,U)O{sub 2-x} with Y/Zr=0.2 at 800 deg. C in air results in a tetragonal phase, whereas (Zr,Y,U)O{sub 2-x} with higher Y/Zr ratios and (Zr,Y,Np)O{sub 2-x} retain the cubic structure. XANES and O/M measurements indicate mixed U(V)-U(VI) and Np(IV)-Np(V) oxidation states after oxidation. Based on X-ray diffraction, O/M and EXAFS measurements, different oxidation mechanisms are identified for U- and Np-doped stabilised zirconia. In contrast to U, excess oxygen vacancies are needed to oxidise Np in (Zr,Y,Np)O{sub 2-x} as the oxidation process competes with Zr for oxygen vacancies. As a consequence, U(VI) and Np(V) can only be obtained in stabilised zirconia with Y/Zr=1 but not in YSZ with Y/Zr=0.2. - Graphical abstract: The O/U ratio in oxidised (Zr,Y,U)O{sub 2-x} depends on the Y/U ratio, whereas O/Np in (Zr,Y,Np)O{sub 2-x} correlates with the Y/(Zr+Np) ratio. This indicates that both Zr and Np compete for oxygen vacancies, which hinders the Np oxidation at low Y/Zr ratios. Display Omitted

  3. Patterning by area selective oxidation

    DOE Patents [OSTI]

    Nam, Chang-Yong; Kamcev, Jovan; Black, Charles T.; Grubbs, Robert

    2015-12-29

    Technologies are described for methods for producing a pattern of a material on a substrate. The methods may comprise receiving a patterned block copolymer on a substrate. The patterned block copolymer may include a first polymer block domain and a second polymer block domain. The method may comprise exposing the patterned block copolymer to a light effective to oxidize the first polymer block domain in the patterned block copolymer. The method may comprise applying a precursor to the block copolymer. The precursor may infuse into the oxidized first polymer block domain and generate the material. The method may comprise applying a removal agent to the block copolymer. The removal agent may be effective to remove the first polymer block domain and the second polymer block domain from the substrate, and may not be effective to remove the material in the oxidized first polymer block domain.

  4. PREPARATION OF REFRACTORY OXIDE CRYSTALS

    DOE Patents [OSTI]

    Grimes, W.R.; Shaffer, J.H.; Watson, G.M.

    1962-11-13

    A method is given for preparing uranium dioxide, thorium oxide, and beryllium oxide in the form of enlarged individual crystals. The surface of a fused alkali metal halide melt containing dissolved uranium, thorium, or beryllium values is contacted with a water-vapor-bearing inert gas stream at a rate of 5 to 10 cubic centimeters per minute per square centimeter of melt surface area. Growth of individual crystals is obtained by prolonged contact. Beryllium oxide-coated uranium dioxide crystals are prepared by disposing uranium dioxide crystals 5 to 20 microns in diameter in a beryllium-containing melt and contacting the melt with a water-vapor-bearing inert gas stream in the same manner. (AEC)

  5. Method for hot pressing beryllium oxide articles

    DOE Patents [OSTI]

    Ballard, Ambrose H.; Godfrey, Jr., Thomas G.; Mowery, Erb H.

    1988-01-01

    The hot pressing of beryllium oxide powder into high density compacts with little or no density gradients is achieved by employing a homogeneous blend of beryllium oxide powder with a lithium oxide sintering agent. The lithium oxide sintering agent is uniformly dispersed throughout the beryllium oxide powder by mixing lithium hydroxide in an aqueous solution with beryllium oxide powder. The lithium hydroxide is converted in situ to lithium carbonate by contacting or flooding the beryllium oxide-lithium hydroxide blend with a stream of carbon dioxide. The lithium carbonate is converted to lithium oxide while remaining fixed to the beryllium oxide particles during the hot pressing step to assure uniform density throughout the compact.

  6. Nitric oxide emissions from engineered soil systems

    SciTech Connect (OSTI)

    Peirce, J.J.; Aneja, V.P.

    2000-03-01

    Sophisticated laboratory equipment and procedures are developed and used in controlled experiments to measure nitric oxide (NO) emissions ranging from 42 to 75 ng N/m{sup 2}{center_dot}s from sludge-amended soil of concern to environmental engineers because nitric oxide emitted to the troposphere is a precursor to troublesome ozone formation and also of concern to agricultural engineers because valuable nitrogen as fertilizer is lost from the soil. Water-filled pore space is confirmed to be of critical importance to NO flux, and the upper layers of soil are determined to contribute the larger portion of the NO fluxing from the soil to the troposphere. More than 42% of the total NO flux comes from the top 1 cm of soil, with NO contributions decreasing exponentially with soil depth and very little if any tropospheric NO contributed from soil at a depth of 20 cm or greater. The results are discussed in terms of microbiological, chemical, and soil transport processes that influence NO flux from sludge-amended soil.

  7. Aromatic-radical oxidation chemistry

    SciTech Connect (OSTI)

    Glassman, I.; Brezinsky, K.

    1993-12-01

    The research effort has focussed on discovering an explanation for the anomalously high CO{sub 2} concentrations observed early in the reaction sequence of the oxidation of cyclopentadiene. To explain this observation, a number of plausible mechanisms have been developed which now await experimental verification. One experimental technique for verifying mechanisms is to probe the reacting system by perturbing the radical concentrations. Two forms of chemical perturbation of the oxidation of cyclopentadiene were begun during this past year--the addition of NO{sub 2} and CO to the reacting mixture.

  8. Solid oxide fuel cell generator

    DOE Patents [OSTI]

    Draper, R.; George, R.A.; Shockling, L.A.

    1993-04-06

    A solid oxide fuel cell generator has a pair of spaced apart tubesheets in a housing. At least two intermediate barrier walls are between the tubesheets and define a generator chamber between two intermediate buffer chambers. An array of fuel cells have tubes with open ends engaging the tubesheets. Tubular, axially elongated electrochemical cells are supported on the tubes in the generator chamber. Fuel gas and oxidant gas are preheated in the intermediate chambers by the gases flowing on the other side of the tubes. Gas leakage around the tubes through the tubesheets is permitted. The buffer chambers reentrain the leaked fuel gas for reintroduction to the generator chamber.

  9. Solid oxide fuel cell generator

    DOE Patents [OSTI]

    Draper, Robert; George, Raymond A.; Shockling, Larry A.

    1993-01-01

    A solid oxide fuel cell generator has a pair of spaced apart tubesheets in a housing. At least two intermediate barrier walls are between the tubesheets and define a generator chamber between two intermediate buffer chambers. An array of fuel cells have tubes with open ends engaging the tubesheets. Tubular, axially elongated electrochemical cells are supported on the tubes in the generator chamber. Fuel gas and oxidant gas are preheated in the intermediate chambers by the gases flowing on the other side of the tubes. Gas leakage around the tubes through the tubesheets is permitted. The buffer chambers reentrain the leaked fuel gas for reintroduction to the generator chamber.

  10. Corrosion of tin oxide at anodic potentials

    SciTech Connect (OSTI)

    Cachet, H.; Froment, M.; Zenia, F.

    1996-02-01

    Tin dioxide electrodes are used as anodes for the electrochemical destruction of organic pollutants in wastewater. The lifetime of such electrodes is limited because of corrosion phenomena which are shown to take place under anodic polarization. These corrosion processes are studied by quartz microbalance experiments, impedance measurements, transmission electron microscopy and scanning electron microscopy observations, carried out on sprayed SnO{sub 2} layers. Localized corrosion phenomena are observed and related to the reaction of radical species with the oxide surface. The extent and the morphology of the attack is shown to depend on the doping (F, Sb) of the SnO{sub 2} electrodes, the solution pH, and the concentration of chloride ions. it is also shown that because of corrosion the conduction band energy level is shifted toward much more positive potentials, allowing the SnO{sub 2} electrode to be activated for oxygen evolution.

  11. Zinc oxide thin film acoustic sensor

    SciTech Connect (OSTI)

    Mohammed, Ali Jasim; Salih, Wafaa Mahdi; Hassan, Marwa Abdul Muhsien; Nusseif, Asmaa Deiaa; Kadhum, Haider Abdullah; Mansour, Hazim Louis

    2013-12-16

    This paper reports the implementation of (750 nm) thickness of Zinc Oxide (ZnO) thin film for the piezoelectric pressure sensors. The film was prepared and deposited employing the spray pyrolysis technique. XRD results show that the growth preferred orientation is the (002) plane. A polycrystalline thin film (close to mono crystallite like) was obtained. Depending on the Scanning Electron Microscopy photogram, the film homogeneity and thickness were shown. The resonance frequency measured (about 19 kHz) and the damping coefficient was calculated and its value was found to be about (2.5538), the thin film be haves as homogeneous for under and over damped. The thin film pressure sensing was approximately exponentially related with frequency, the thin film was observed to has a good response for mechanical stresses also it is a good material for the piezoelectric properties.

  12. Corrective Measures Process

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

    Corrective Measures Process Corrective Measures Process We follow a stringent corrective measures process for legacy cleanup. August 1, 2013 Corrective measures process Corrective measures process

  13. Perovskite catalysts for oxidative coupling

    DOE Patents [OSTI]

    Campbell, Kenneth D.

    1991-01-01

    Perovskites of the structure A.sub.2 B.sub.2 C.sub.3 O.sub.10 are useful as catalysts for the oxidative coupling of lower alkane to heavier hydrocarbons. A is alkali metal; B is lanthanide or lanthanum, cerium, neodymium, samarium, praseodymium, gadolinium or dysprosium; and C is titanium.

  14. Solid oxide fuel cell generator

    DOE Patents [OSTI]

    Di Croce, A.M.; Draper, R.

    1993-11-02

    A solid oxide fuel cell generator has a plenum containing at least two rows of spaced apart, annular, axially elongated fuel cells. An electrical conductor extending between adjacent rows of fuel cells connects the fuel cells of one row in parallel with each other and in series with the fuel cells of the adjacent row. 5 figures.

  15. Formulations for iron oxides dissolution

    DOE Patents [OSTI]

    Horwitz, Earl P.; Chiarizia, Renato

    1992-01-01

    A mixture of a di- or polyphosphonic acid and a reductant wherein each is present in a sufficient amount to provide a synergistic effect with respect to the dissolution of metal oxides and optionally containing corrosion inhibitors and pH adjusting agents.

  16. Perovskite catalysts for oxidative coupling

    DOE Patents [OSTI]

    Campbell, K.D.

    1991-06-25

    Perovskites of the structure A[sub 2]B[sub 2]C[sub 3]O[sub 10] are useful as catalysts for the oxidative coupling of lower alkane to heavier hydrocarbons. A is alkali metal; B is lanthanide or lanthanum, cerium, neodymium, samarium, praseodymium, gadolinium or dysprosium; and C is titanium.

  17. Solid oxide fuel cell generator

    DOE Patents [OSTI]

    Di Croce, A. Michael; Draper, Robert

    1993-11-02

    A solid oxide fuel cell generator has a plenum containing at least two rows of spaced apart, annular, axially elongated fuel cells. An electrical conductor extending between adjacent rows of fuel cells connects the fuel cells of one row in parallel with each other and in series with the fuel cells of the adjacent row.

  18. METHOD AND APPARATUS FOR MEASURING RADIATION

    DOE Patents [OSTI]

    Reeder, S.D.

    1962-04-17

    A chemical dosimeter for measuring the progress of a radiation-induced oxidation-reduction reaction is described. The dosimeter comprises a container filled with an aqueous chemical oxidation-reduction system which reacts quantitatively to the radiation. An anode of the group consisting of antimony and tungsten and a cathode of the group consisting of gold and platnium are inserted into the system. Means are provided to stir the system and a potential sensing device is connected across the anode and cathode to detect voltage changes. (AEC)

  19. Vehicle Technologies Office Merit Review 2015: Metal Oxide Nano...

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

    Metal Oxide Nano-Array Catalysts for Low Temperature Diesel Oxidation Vehicle Technologies Office Merit Review 2015: Metal Oxide Nano-Array Catalysts for Low Temperature Diesel ...

  20. Understanding Interactions between Manganese Oxide and Gold That...

    Office of Scientific and Technical Information (OSTI)

    Water Oxidation Prev Next Title: Understanding Interactions between Manganese Oxide and Gold That Lead to Enhanced Activity for Electrocatalytic Water Oxidation ...

  1. Aerosol Oxidation Speeds Up in Smoggy Air

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

    Aerosol Oxidation Speeds Up in Smoggy Air Aerosol Oxidation Speeds Up in Smoggy Air Print Wednesday, 17 February 2016 11:37 Organic aerosols (nanometer-sized liquid or solid ...

  2. Structural Determination of Marine Bacteriogenic Manganese Oxides

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

    oxides precipitated around a spore (cell) of the marine Mn(II)-oxidizing bac-terium, Bacillus sp., strain SG-1. This cell is about 0.5 m diameter (small axis). Bacterial...

  3. Complex oxides useful for thermoelectric energy conversion

    SciTech Connect (OSTI)

    Majumdar, Arunava; Ramesh, Ramamoorthy; Yu, Choongho; Scullin, Matthew L.; Huijben, Mark

    2012-07-17

    The invention provides for a thermoelectric system comprising a substrate comprising a first complex oxide, wherein the substrate is optionally embedded with a second complex oxide. The thermoelectric system can be used for thermoelectric power generation or thermoelectric cooling.

  4. Dysprosium oxide and dysprosium-oxide-doped titanium oxide thin films grown by atomic layer deposition

    SciTech Connect (OSTI)

    Tamm, Aile Kozlova, Jekaterina; Aarik, Lauri; Aarik, Jaan; Kukli, Kaupo; Link, Joosep; Stern, Raivo

    2015-01-15

    Dysprosium oxide and dysprosium-oxide-doped titanium oxide thin films were grown by atomic layer deposition on silicon substrates. For depositing dysprosium and titanium oxides Dy(thd){sub 3}-O{sub 3} and TiCl{sub 4}-O{sub 3} were used as precursors combinations. Appropriate parameters for Dy(thd){sub 3}-O{sub 3} growth process were obtained by using a quartz crystal microbalance system. The Dy{sub 2}O{sub 3} films were deposited on planar substrates and on three-dimensional substrates with aspect ratio 1:20. The Dy/Ti ratio of Dy{sub 2}O{sub 3}-doped TiO{sub 2} films deposited on a planar silicon substrate ranged from 0.04 to 0.06. Magnetometry studies revealed that saturation of magnetization could not be observed in planar Dy{sub 2}O{sub 3} films, but it was observable in Dy{sub 2}O{sub 3} films on 3D substrates and in doped TiO{sub 2} films with a Dy/Ti atomic ratio of 0.06. The latter films exhibited saturation magnetization 10{sup −6} A cm{sup 2} and coercivity 11 kA/m at room temperature.

  5. Electronic structure of graphene oxide and reduced graphene oxide monolayers

    SciTech Connect (OSTI)

    Sutar, D. S.; Singh, Gulbagh; Divakar Botcha, V.

    2012-09-03

    Graphene oxide (GO) monolayers obtained by Langmuir Blodgett route and suitably treated to obtain reduced graphene oxide (RGO) monolayers were studied by photoelectron spectroscopy. Upon reduction of GO to form RGO C1s x-ray photoelectron spectra showed increase in graphitic carbon content, while ultraviolet photoelectron spectra showed increase in intensity corresponding to C2p-{pi} electrons ({approx}3.5 eV). X-ray excited Auger transitions C(KVV) and plasmon energy loss of C1s photoelectrons have been analyzed to elucidate the valence band structure. The effective number of ({pi}+{sigma}) electrons as obtained from energy loss spectra was found to increase by {approx}28% on reduction of GO.

  6. High quality oxide films on substrates

    DOE Patents [OSTI]

    Ruckman, M.W.; Strongin, M.; Gao, Y.L.

    1994-02-01

    A method is described for providing an oxide film of a material on the surface of a substrate using a reactive deposition of the material onto the substrate surface in the presence of a solid or liquid layer of an oxidizing gas. The oxidizing gas is provided on the substrate surface in an amount sufficient to dissipate the latent heat of condensation occurring during deposition as well as creating a favorable oxidizing environment for the material. 4 figures.

  7. High quality oxide films on substrates

    DOE Patents [OSTI]

    Ruckman, Mark W.; Strongin, Myron; Gao, Yong L.

    1994-01-01

    A method for providing an oxide film of a material on the surface of a substrate using a reactive deposition of the material onto the substrate surface in the presence of a solid or liquid layer of an oxidizing gas. The oxidizing gas is provided on the substrate surface in an amount sufficient to dissipate the latent heat of condensation occurring during deposition as well as creating a favorable oxidizing environment for the material.

  8. Vapor phase modifiers for oxidative coupling

    DOE Patents [OSTI]

    Warren, Barbara K.

    1991-01-01

    Volatilized metal compounds retard vapor phase alkane conversion reactions in oxidative coupling processes that convert lower alkanes to higher hydrocarbons.

  9. Effect of oxygen and oxidation on tensile properties of V-5Cr-5Ti alloy

    SciTech Connect (OSTI)

    Natesan, K.; Soppet, W.K.

    1995-09-01

    Oxidation studies were conducted on V-5Cr-5Ti alloy specimens in an air environment to evaluate the oxygen uptake behavior of the alloy as a function of temperature and exposure time. The oxidation rates calculated from parabolic kinetic measurements of thermogravimetric testing and confirmed by microscopic analyses of cross sections of exposed specimens were 5, 17, and 27 {mu}m per year after exposure at 300, 400, and 500{degrees}C, respectively. Uniaxial-tensile tests were conducted at room temperature and at 500C on preoxidized specimens of the alloy to examine the effects of oxidation and oxygen migration on tensile strength and ductility. Microstructural characteristics of several of the tested specimens were determined by electron optics techniques. Correlations were developed between tensile strength and ductility of the oxidized alloy and microstructural characteristics such as oxide thickness, depth of hardened layer, depth of intergranular fracture zone, and transverse crack length.

  10. Physical and electrochemical study of cobalt oxide nano- and microparticles

    SciTech Connect (OSTI)

    Alburquenque, D.; Vargas, E.; Denardin, J.C.; Escrig, J.; Marco, J.F.; Gautier, J.L.

    2014-07-01

    Cobalt oxide nanocrystals of size 17–21 nm were synthesized by a simple reaction between cobalt acetate (II) and dodecylamine. On the other hand, micrometric Co{sub 3}O{sub 4} was prepared using the ceramic method. The structural examination of these materials was performed using powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM and HRTEM). XRD studies showed that the oxides were pure, well-crystallized, spinel cubic phases with a-cell parameter of 0.8049 nm and 0.8069 nm for the nano and micro-oxide, respectively. The average particle size was 19 nm (nano-oxide) and 1250 μm (micro-oxide). Morphological studies carried out by SEM and TEM analyses have shown the presence of octahedral particles in both cases. Bulk and surface properties investigated by X-ray photoelectron spectroscopy (XPS), point zero charge (pzc), FTIR and cyclic voltammetry indicated that there were no significant differences in the composition on both materials. The magnetic behavior of the samples was determined using a vibrating sample magnetometer. The compounds showed paramagnetic character and no coercivity and remanence in all cases. Galvanostatic measurements of electrodes formed with nanocrystals showed better performance than those built with micrometric particles. - Highlights: • Spinel Co{sub 3}O{sub 4} nanoparticles and microparticles with same structure but with different cell parameters, particle size and surface area were synthesized. • Oxide nanoparticles showed better electrochemical behavior than micrometric ones due to area effect.