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Sample records for rocksalt copper monoxide

  1. A DFT study of rocksalt proxy copper monochalcogenide structures - Implications for possible high-Tc superconductivity

    NASA Astrophysics Data System (ADS)

    Grant, P. M.; Hammond, R. H.; W2AGZ Technologies/GLAM, Stanford University Collaboration

    2014-03-01

    We report findings derived from a series of DFT calculations on the structural stability and paramagnetic ground states of four idealized copper monochalcogenide (CuO, CuS, CuSe, CuTe) rocksalt structures. Note that none of these target compounds occur naturally, but can possibly be fabricated using ``forced epitaxy'' MBE methods, as has been done to grow CuO tetragonal rocksalt films 5-6 monolayers thick.[1,2] Therefore, we treat all examples we report herein as proxies intended to explore candidate implications for possible future high-TC materials. In particular, we find, as might be expected from the long accepted Van Vleck-Anderson-Hubbard formalism describing antiferromagnetic insulators, the Neel temperature scales upward roughly as the width of the spin-carrying bands near or adjacent to the Fermi level or energy gap. We conclude such trend might result in higher superconducting transition temperatures should this be mediated by carrier-spin excitation/fluctuation driven pairing scaled by TN. Finally, we briefly discuss synthetic paths to realizing actual embodiments of our proxy exercises.

  2. Cobalt promoted copper manganese oxide catalysts for ambient temperature carbon monoxide oxidation.

    PubMed

    Jones, Christopher; Taylor, Stuart H; Burrows, Andrew; Crudace, Mandy J; Kiely, Christopher J; Hutchings, Graham J

    2008-04-14

    Low levels of cobalt doping (1 wt%) of copper manganese oxide enhances its activity for carbon monoxide oxidation under ambient conditions and the doped catalyst can display higher activity than current commercial catalysts.

  3. Analysis of S-nitrosothiols via Copper Cysteine (2C) and Copper Cysteine - Carbon Monoxide (3C) Methods

    PubMed Central

    Rogers, Stephen C.; Gibbons, Lindsey B.; Griffin, Sherraine; Doctor, Allan

    2012-01-01

    This chapter summarizes the principles of RSNO measurement in the gas phase, utilizing ozone-based chemiluminescence and the copper cysteine (2C) ± carbon monoxide (3C) reagent. Although an indirect method for quantifying RSNOs, this assay represents one of the most robust methodologies available. It exploits the NO• detection sensitivity of ozone based chemiluminscence, which is within the range required to detect physiological concentrations of RSNO metabolites. Additionally, the specificity of the copper cysteine (2C and 3C) reagent for RSNOs negates the need for sample pretreatment, thereby minimizing the likelihood of sample contamination (false positive results), NO species inter-conversion, or the loss of certain highly labile RSNO species. Herein, we outline the principles of this methodology, summarizing key issues, potential pitfalls and corresponding solutions. PMID:23116707

  4. Carbon monoxide oxidation over three different states of copper: Development of a model metal oxide catalyst

    SciTech Connect

    Jernigan, Glenn Geoffrey

    1994-10-01

    Carbon monoxide oxidation was performed over the three different oxidation states of copper -- metallic (Cu), copper (I) oxide (Cu2O), and copper (II) oxide (CuO) as a test case for developing a model metal oxide catalyst amenable to study by the methods of modern surface science and catalysis. Copper was deposited and oxidized on oxidized supports of aluminum, silicon, molybdenum, tantalum, stainless steel, and iron as well as on graphite. The catalytic activity was found to decrease with increasing oxidation state (Cu > Cu2O > CuO) and the activation energy increased with increasing oxidation state (Cu, 9 kcal/mol < Cu2O, 14 kcal/mol < CuO, 17 kcal/mol). Reaction mechanisms were determined for the different oxidation states. Lastly, NO reduction by CO was studied. A Cu and CuO catalyst were exposed to an equal mixture of CO and NO at 300--350 C to observe the production of N2 and CO2. At the end of each reaction, the catalyst was found to be Cu2O. There is a need to study the kinetics of this reaction over the different oxidation states of copper.

  5. A DFT study of electron-phonon coupling in proxy rocksalt CuX (X = S, Se, Te) structures and its relationship to possible manifestation of superconductivity

    NASA Astrophysics Data System (ADS)

    Grant, Paul; Hammond, Robert

    2015-03-01

    We have previously reported our computational studies on idealized copper monochalcogenide rocksalt structures, both cubic and tetragonal, focusing on their possible antiferromagnetic properties as determined within a Van Vleck-Mott-Anderson-Hubbard framework. For all values of Hubbard U in the range 0-7 eV, only copper monoxide exhibits a Mott-Hubbard electronic structure, the remainder (S, Se, Te) yielding metallic states characterized by nesting Fermi surfaces arising from Jahn-Teller degenerate s-p overlap. These results suggest exploring possible manifestation of superconductivity via electron-phonon mediated Cooper pairing. We will disclose our results to date applying the Eliashberg-McMillan-Allen-Dynes strong coupling framework to the DFT -derived electronic and vibrational states of CuS, CuSe and CuTe.

  6. Copper-catalyzed extended Pummerer reactions of ketene dithioacetal monoxides with alkynyl sulfides and ynamides with an accompanying oxygen rearrangement.

    PubMed

    Murakami, Kei; Imoto, Junichi; Matsubara, Hiroshi; Yoshida, Suguru; Yorimitsu, Hideki; Oshima, Koichiro

    2013-04-26

    The first examples of metal-catalyzed extended Pummerer reactions through the activation of sulfoxides are described. The copper-catalyzed reactions of ketene dithioacetal monoxides with alkynyl sulfides and ynamides provided a wide variety of γ,γ-disulfanyl-β,γ-unsaturated carbonyl compounds with an accompanying oxygen rearrangement. The products can be easily converted into 1,4-dicarbonyl compounds and substituted heteroaromatics. DFT calculations and mechanistic experiments revealed a new interesting stepwise addition/oxygen rearrangement mechanism.

  7. Electroreduction of carbon monoxide to liquid fuel on oxide-derived nanocrystalline copper.

    PubMed

    Li, Christina W; Ciston, Jim; Kanan, Matthew W

    2014-04-24

    The electrochemical conversion of CO2 and H2O into liquid fuel is ideal for high-density renewable energy storage and could provide an incentive for CO2 capture. However, efficient electrocatalysts for reducing CO2 and its derivatives into a desirable fuel are not available at present. Although many catalysts can reduce CO2 to carbon monoxide (CO), liquid fuel synthesis requires that CO is reduced further, using H2O as a H(+) source. Copper (Cu) is the only known material with an appreciable CO electroreduction activity, but in bulk form its efficiency and selectivity for liquid fuel are far too low for practical use. In particular, H2O reduction to H2 outcompetes CO reduction on Cu electrodes unless extreme overpotentials are applied, at which point gaseous hydrocarbons are the major CO reduction products. Here we show that nanocrystalline Cu prepared from Cu2O ('oxide-derived Cu') produces multi-carbon oxygenates (ethanol, acetate and n-propanol) with up to 57% Faraday efficiency at modest potentials (-0.25 volts to -0.5 volts versus the reversible hydrogen electrode) in CO-saturated alkaline H2O. By comparison, when prepared by traditional vapour condensation, Cu nanoparticles with an average crystallite size similar to that of oxide-derived copper produce nearly exclusive H2 (96% Faraday efficiency) under identical conditions. Our results demonstrate the ability to change the intrinsic catalytic properties of Cu for this notoriously difficult reaction by growing interconnected nanocrystallites from the constrained environment of an oxide lattice. The selectivity for oxygenates, with ethanol as the major product, demonstrates the feasibility of a two-step conversion of CO2 to liquid fuel that could be powered by renewable electricity.

  8. Electroreduction of carbon monoxide to liquid fuel on oxide-derived nanocrystalline copper

    NASA Astrophysics Data System (ADS)

    Li, Christina W.; Ciston, Jim; Kanan, Matthew W.

    2014-04-01

    The electrochemical conversion of CO2 and H2O into liquid fuel is ideal for high-density renewable energy storage and could provide an incentive for CO2 capture. However, efficient electrocatalysts for reducing CO2 and its derivatives into a desirable fuel are not available at present. Although many catalysts can reduce CO2 to carbon monoxide (CO), liquid fuel synthesis requires that CO is reduced further, using H2O as a H+ source. Copper (Cu) is the only known material with an appreciable CO electroreduction activity, but in bulk form its efficiency and selectivity for liquid fuel are far too low for practical use. In particular, H2O reduction to H2 outcompetes CO reduction on Cu electrodes unless extreme overpotentials are applied, at which point gaseous hydrocarbons are the major CO reduction products. Here we show that nanocrystalline Cu prepared from Cu2O (`oxide-derived Cu') produces multi-carbon oxygenates (ethanol, acetate and n-propanol) with up to 57% Faraday efficiency at modest potentials (-0.25 volts to -0.5 volts versus the reversible hydrogen electrode) in CO-saturated alkaline H2O. By comparison, when prepared by traditional vapour condensation, Cu nanoparticles with an average crystallite size similar to that of oxide-derived copper produce nearly exclusive H2 (96% Faraday efficiency) under identical conditions. Our results demonstrate the ability to change the intrinsic catalytic properties of Cu for this notoriously difficult reaction by growing interconnected nanocrystallites from the constrained environment of an oxide lattice. The selectivity for oxygenates, with ethanol as the major product, demonstrates the feasibility of a two-step conversion of CO2 to liquid fuel that could be powered by renewable electricity.

  9. Interfacial Cu+ promoted surface reactivity: Carbon monoxide oxidation reaction over polycrystalline copper-titania catalysts

    DOE PAGES

    Senanayake, S. D.; Pappoe, N. A.; Nguyen-Phan, T. -D.; ...

    2016-10-01

    We have studied the catalytic carbon monoxide (CO) oxidation (CO+0.5O2 → CO2) reaction using a powder catalyst composed of both copper (5wt% loading) and titania (CuOx-TiO2). Our study was focused on revealing the role of Cu, and the interaction between Cu and TiO2, by systematic comparison between two nanocatalysts, CuOx-TiO2 and pure CuOx. We interrogated these catalysts under in situ conditions using X-ray Diffraction (XRD), X-ray Absorption Fine Structure (XAFS) and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) to probe the structure and electronic properties of the catalyst at all stages of the reaction and simultaneously probe the surface statesmore » or intermediates of this reaction. With the aid of several ex situ characterization techniques including Transmission Electron Microscopy (TEM), the local catalyst morphology and structure was also studied. Our results show that a CuOx-TiO2 system is more active than bulk CuOx for the CO oxidation reaction due to its lower onset temperature and better stability at higher temperatures. Our results also suggests that a surface Cu+ species observed in the CuOx-TiO2 interface are likely to be a key player in the CO oxidation mechanism, while implicating that the stabilization of this species is probably associated with the oxide-oxide interface. Both in situ DRIFTS and XAFS measurements reveal that there is likely to be a Cu(Ti)-O mixed oxide at this interface. We discuss the nature of this Cu(Ti)-O interface and interpret its role on the CO oxidation reaction.« less

  10. Interfacial Cu+ promoted surface reactivity: Carbon monoxide oxidation reaction over polycrystalline copper-titania catalysts

    NASA Astrophysics Data System (ADS)

    Senanayake, Sanjaya D.; Pappoe, Naa Adokaley; Nguyen-Phan, Thuy-Duong; Luo, Si; Li, Yuanyuan; Xu, Wenqian; Liu, Zongyuan; Mudiyanselage, Kumudu; Johnston-Peck, Aaron C.; Frenkel, Anatoly I.; Heckler, Ilana; Stacchiola, Dario; Rodriguez, José A.

    2016-10-01

    We have studied the catalytic carbon monoxide (CO) oxidation (CO + 0.5O2 → CO2) reaction using a powder catalyst composed of both copper (5 wt.% loading) and titania (CuOx-TiO2). Our study was focused on revealing the role of Cu, and the interaction between Cu and TiO2, by systematic comparison between two nanocatalysts, CuOx-TiO2 and pure CuOx. We interrogated these catalysts under in situ conditions using X-ray diffraction (XRD), X-ray absorption fine structure (XAFS) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) to probe the structure and electronic properties of the catalyst at all stages of the reaction and simultaneously probe the surface states or intermediates of this reaction. With the aid of several ex situ characterization techniques including transmission electron microscopy (TEM), the local catalyst morphology and structure were also studied. Our results show that a CuOx-TiO2 system is more active than bulk CuOx for the CO oxidation reaction due to its lower onset temperature and better stability at higher temperatures. Our results also suggest that surface Cu+ species observed in the CuOx-TiO2 interface are likely to be a key player in the CO oxidation mechanism, while implicating that the stabilization of this species is probably associated with the oxide-oxide interface. Both in situ DRIFTS and XAFS measurements reveal that there is likely to be a Cu(Ti)-O mixed oxide at this interface. We discuss the nature of this Cu(Ti)-O interface and interpret its role on the CO oxidation reaction.

  11. Catalysts on the basis of activated aluminum alloys: II. Study of carbon monoxide oxidation on copper-containing catalysts by the transient response method

    SciTech Connect

    Subbotin, A.N.; Gudkov, B.S.; Yakerson, V.I.

    1995-03-01

    Specific features of the mechanism of CO oxidation on copper-containing catalysts prepared from copper-aluminum alloys are studied by the transient-response method using mass-spectrometric analysis of the reaction mixture. Two forms of oxygen, related to the copper component of the catalyst, are found to take part in the reaction. Carbon monoxide interacts either from the gas phase or from a very weakly bonded adsorption complex at the surface.

  12. Substitution of silver for copper in the binuclear Mo/Cu center of carbon monoxide dehydrogenase from Oligotropha carboxidovorans.

    PubMed

    Wilcoxen, Jarett; Snider, Samantha; Hille, Russ

    2011-08-24

    Carbon monoxide dehydrogenase from Oligotropha carboxidovorans catalyzes the aerobic oxidation of carbon monoxide to carbon dioxide, providing the organism both a carbon source and energy for growth. The active site of the native enzyme is a unique binuclear molybdenum- and copper-containing center. Here we show that silver can be substituted for copper in the active site to yield a functional enzyme. The characteristic hyperfine coupling of the I = ½ nucleus of Ag is evident in the EPR signal of the binuclear active site observed upon reduction with CO, indicating both the incorporation of silver into the active site and, remarkably, retention of the catalytic activity. The silver-substituted enzyme is reduced by CO with an observed limiting rate constant of 8.1 s(-1), which can be compared with the value of 51 s(-1) for the wild-type enzyme. Steady-state kinetics for the Ag-substituted enzyme yielded k(cat) = 8.2 s(-1) and K(m) = 2.95 μM at pH 7.2.

  13. Catalytic reduction of nitric oxide with carbon monoxide on copper-cobalt oxides supported on nano-titanium dioxide.

    PubMed

    Chen, Xia; Zhang, Junfeng; Huang, Yan; Tong, Zhiquan; Huang, Ming

    2009-01-01

    A series of copper-cobalt oxides supported on nano-titanium dioxide were prepared for the reduction of nitric oxide with carbon monoxide and characterized using techniques such as XRD, BET and TPR. Catalyst CuCoOx/TiO2 with Cu/Co molar ratio of 1/2, Cu-Co total loading of 30% at the calcination temperature of 350 degrees C formed CuCo2O4 spinel and had the highest activity. NO conversion reached 98.9% at 200 degrees C. Mechanism of the reduction was also investigated, N2O was mainly yielded below 100 degrees C, while N2 was produced instead at higher temperature. O2 was supposed to accelerate the reaction between NOx and CO for its oxidation of NO to give more easily reduced NO2, but the oxidation of CO by O2 to CO2 decreased the speed of the reaction greatly. Either SO2 or H2O had no adverse impact on the activity of NO reduction; however, in the presence of both SO2 and H2O, the catalyst deactivated quickly.

  14. Interfacial Cu+ promoted surface reactivity: Carbon monoxide oxidation reaction over polycrystalline copper-titania catalysts

    SciTech Connect

    Senanayake, S. D.; Pappoe, N. A.; Nguyen-Phan, T. -D.; Luo, S.; Li, Y.; Xu, W.; Liu, Z.; Mudiyanselage, K.; Johnston-Peck, A. C.; Frenkel, A. I.; Heckler, I.; Stacchiola, D.; Rodriguez, J. A.

    2016-10-01

    We have studied the catalytic carbon monoxide (CO) oxidation (CO+0.5O2 → CO2) reaction using a powder catalyst composed of both copper (5wt% loading) and titania (CuOx-TiO2). Our study was focused on revealing the role of Cu, and the interaction between Cu and TiO2, by systematic comparison between two nanocatalysts, CuOx-TiO2 and pure CuOx. We interrogated these catalysts under in situ conditions using X-ray Diffraction (XRD), X-ray Absorption Fine Structure (XAFS) and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) to probe the structure and electronic properties of the catalyst at all stages of the reaction and simultaneously probe the surface states or intermediates of this reaction. With the aid of several ex situ characterization techniques including Transmission Electron Microscopy (TEM), the local catalyst morphology and structure was also studied. Our results show that a CuOx-TiO2 system is more active than bulk CuOx for the CO oxidation reaction due to its lower onset temperature and better stability at higher temperatures. Our results also suggests that a surface Cu+ species observed in the CuOx-TiO2 interface are likely to be a key player in the CO oxidation mechanism, while implicating that the stabilization of this species is probably associated with the oxide-oxide interface. Both in situ DRIFTS and XAFS measurements reveal that there is likely to be a Cu(Ti)-O mixed oxide at this interface. We discuss the nature of this Cu(Ti)-O interface and interpret its role on the CO oxidation reaction.

  15. Interfacial Cu+ promoted surface reactivity: Carbon monoxide oxidation reaction over polycrystalline copper-titania catalysts

    SciTech Connect

    Senanayake, S. D.; Pappoe, N. A.; Nguyen-Phan, T. -D.; Luo, S.; Li, Y.; Xu, W.; Liu, Z.; Mudiyanselage, K.; Johnston-Peck, A. C.; Frenkel, A. I.; Heckler, I.; Stacchiola, D.; Rodriguez, J. A.

    2016-10-01

    We have studied the catalytic carbon monoxide (CO) oxidation (CO+0.5O2 → CO2) reaction using a powder catalyst composed of both copper (5wt% loading) and titania (CuOx-TiO2). Our study was focused on revealing the role of Cu, and the interaction between Cu and TiO2, by systematic comparison between two nanocatalysts, CuOx-TiO2 and pure CuOx. We interrogated these catalysts under in situ conditions using X-ray Diffraction (XRD), X-ray Absorption Fine Structure (XAFS) and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) to probe the structure and electronic properties of the catalyst at all stages of the reaction and simultaneously probe the surface states or intermediates of this reaction. With the aid of several ex situ characterization techniques including Transmission Electron Microscopy (TEM), the local catalyst morphology and structure was also studied. Our results show that a CuOx-TiO2 system is more active than bulk CuOx for the CO oxidation reaction due to its lower onset temperature and better stability at higher temperatures. Our results also suggests that a surface Cu+ species observed in the CuOx-TiO2 interface are likely to be a key player in the CO oxidation mechanism, while implicating that the stabilization of this species is probably associated with the oxide-oxide interface. Both in situ DRIFTS and XAFS measurements reveal that there is likely to be a Cu(Ti)-O mixed oxide at this interface. We discuss the nature of this Cu(Ti)-O interface and interpret its role on the CO oxidation reaction.

  16. Hydrocarbon reservoirs with rocksalt caprocks: time dependence of subsidence effects and the influence of the rocksalt creep model

    NASA Astrophysics Data System (ADS)

    Marketos, George; Govers, Rob; Spiers, Chris

    2015-04-01

    Rocksalt is the caprock for a large number of hydrocarbon reservoirs. Understanding its response to extraction-induced stress perturbations can therefore be very important when calculating the resulting deformation and associated subsidence above such fields. We investigate how flow in the rocksalt leads to time-dependent deformation of the ground surface using numerical models that simulate the mechanical response of the subsurface. Rock mechanical experiments have demonstrated that rocksalt can flow by linear creep or power-law creep, depending on stress and grain size among others. Given that we often do not have data from cores that constrain these quantities, we investigate the two rocksalt flow laws as alternatives. Here, we focus specifically on differences in the surface imprints of these two types of flow. Mechanical models for linear creep show that the rocksalt exhibits two time scales in response to the reservoir pumping. The first, and shortest, time scale reflects flow that is driven by relaxation of stresses in the vicinity of the reservoir. At the surface, this results in maximum subsidence that is increasing with time. The second time scale reflects closed-conduit flow within the rocksalt layer that is driven by mean stresses equilibration. Interestingly, this results in a decrease in the maximum subsidence above the reservoir.

  17. Stability of a new cubic monoxide of Thorium under pressure

    PubMed Central

    Sun, Weiwei; Luo, Wei; Ahuja, Rajeev

    2015-01-01

    Density functional theory has been applied to elucidate the stability of thorium monoxide (ThO). It is found out that the pressure can stabilize the rocksalt phase of ThO, and the transition pressure is estimated between 14 and 22 GPa. The stability of ThO can be attributed due to the gradually filling 5f orbitals at the expense of 7s and 6d electrons in Th metal. For ThO, the pressure induces stronger Th-O bond reflected by the newly established 6d-2p hybridization which is the dominant cause of its stability. The phonon dispersion curves of the rocksalt phase show the positive frequencies which indicates its dynamical stability. Our successful prediction of the stabilization of the metallic ThO has proposed a route to synthesize novel actinide monoxides. PMID:26337015

  18. Magnetic coupling at perovskite and rock-salt structured interfaces

    SciTech Connect

    Matvejeff, M.; Ahvenniemi, E.; Takahashi, R.; Lippmaa, M.

    2015-10-05

    We study magnetic coupling between hole-doped manganite layers separated by either a perovskite or a rock-salt barrier of variable thickness. Both the type and the quality of the interface have a strong impact on the minimum critical barrier thickness where the manganite layers become magnetically decoupled. A rock-salt barrier layer only 1 unit cell (0.5 nm) thick remains insulating and is able to magnetically de-couple the electrode layers. The technique can therefore be used for developing high-performance planar oxide electronic devices such as magnetic tunnel junctions and quantum well structures that depend on magnetically and electronically sharp heterointerfaces.

  19. A DFT study of electron-phonon mediated superconductivity in doped Mott-Hubbard proxy cubic-tetragonal copper monoxide

    NASA Astrophysics Data System (ADS)

    Grant, Paul

    We report our preliminary study of electron-phonon mediated Cooper pairing as a component underlying high temperature superconductivity, in the presence of a Hubbard U driven antiferromagnetic ground state, subject to itinerant carrier doping, in the copper oxide perovskites. Our model is based on a proxy CuO fcc cubic-tetragonal structure that contains the basic physics of the electronic structure of copper oxide perovskites readily amenable to numerical analysis. We explore its phase diagram as a function of carrier concentration and coulomb repulsion ranging from the pure Mott-Hubbard AF insulating state to that of a metallic Fermi liquid, focusing on those conditions which might manifest high temperature superconducting behavior. In the Fermi liquid state, we find clear evidence that superconductivity arises from Jahn-Teller instabilities in the CuO bond which guided Bednorz and Mueller on the path to their 1986 discovery.

  20. Electroreduction of carbon monoxide over a copper nanocube catalyst: Surface structure and pH dependence on selectivity

    SciTech Connect

    Roberts, F. Sloan; Kuhl, Kendra P.; Nilsson, Anders

    2016-02-16

    The activity and selectivity for CO2/CO reduction over copper electrodes is strongly dependent on the local surface structure of the catalyst and the pH of the electrolyte. Here we investigate a unique, copper nanocube surface (CuCube) as a CO reduction electrode under neutral and basic pH, using online electrochemical mass spectroscopy (OLEMS) to determine the onset potentials and relative intensities of methane and ethylene production. To relate the unique selectivity to the surface structure, the CuCube surface reactivity is compared to polycrystalline copper and three single crystals under the same reaction conditions. Here, we find that the high selectivity for ethylene over the CuCube surface is most comparable to the Cu(100) surface, which has the cubic unit cell. However, the suppression of methane production over CuCube is unique to that particular surface. Basic pH is also shown to enhance ethylene selectivity on all surfaces, again with the CuCube surface being unique.

  1. Electroreduction of carbon monoxide over a copper nanocube catalyst: Surface structure and pH dependence on selectivity

    DOE PAGES

    Roberts, F. Sloan; Kuhl, Kendra P.; Nilsson, Anders

    2016-02-16

    The activity and selectivity for CO2/CO reduction over copper electrodes is strongly dependent on the local surface structure of the catalyst and the pH of the electrolyte. Here we investigate a unique, copper nanocube surface (CuCube) as a CO reduction electrode under neutral and basic pH, using online electrochemical mass spectroscopy (OLEMS) to determine the onset potentials and relative intensities of methane and ethylene production. To relate the unique selectivity to the surface structure, the CuCube surface reactivity is compared to polycrystalline copper and three single crystals under the same reaction conditions. Here, we find that the high selectivity formore » ethylene over the CuCube surface is most comparable to the Cu(100) surface, which has the cubic unit cell. However, the suppression of methane production over CuCube is unique to that particular surface. Basic pH is also shown to enhance ethylene selectivity on all surfaces, again with the CuCube surface being unique.« less

  2. Acetaldehyde as an Intermediate in the Electroreduction of Carbon Monoxide to Ethanol on Oxide‐Derived Copper

    PubMed Central

    Bertheussen, Erlend; Verdaguer‐Casadevall, Arnau; Ravasio, Davide; Montoya, Joseph H.; Trimarco, Daniel B.; Roy, Claudie; Meier, Sebastian; Wendland, Jürgen; Nørskov, Jens K.

    2015-01-01

    Abstract Oxide‐derived copper (OD‐Cu) electrodes exhibit unprecedented CO reduction performance towards liquid fuels, producing ethanol and acetate with >50 % Faradaic efficiency at −0.3 V (vs. RHE). By using static headspace‐gas chromatography for liquid phase analysis, we identify acetaldehyde as a minor product and key intermediate in the electroreduction of CO to ethanol on OD‐Cu electrodes. Acetaldehyde is produced with a Faradaic efficiency of ≈5 % at −0.33 V (vs. RHE). We show that acetaldehyde forms at low steady‐state concentrations, and that free acetaldehyde is difficult to detect in alkaline solutions using NMR spectroscopy, requiring alternative methods for detection and quantification. Our results represent an important step towards understanding the CO reduction mechanism on OD‐Cu electrodes. PMID:26692282

  3. Acetaldehyde as an intermediate in the electroreduction of carbon monoxide to ethanol on oxide-derived copper

    SciTech Connect

    Bertheussen, Erlend; Verdaguer-Casadevall, Arnau; Ravasio, Davide; Montoya, Joseph H.; Trimarco, Daniel B.; Roy, Claudie; Meier, Sebastian; Wendland, Jürgen; Nørskov, Jens K.; Stephens, Ifan E. L.; Chorkendorff, Ib

    2015-12-21

    Oxide-derived copper (OD-Cu) electrodes exhibit unprecedented CO reduction performance towards liquid fuels, producing ethanol and acetate with >50 % Faradaic efficiency at -0.3 V (vs. RHE). By using static headspace-gas chromatography for liquid phase analysis, we identify acetaldehyde as a minor product and key intermediate in the electroreduction of CO to ethanol on OD-Cu electrodes. Acetaldehyde is produced with a Faradaic efficiency of ≈5 % at -0.33 V (vs. RHE). We show that acetaldehyde forms at low steady-state concentrations, and that free acetaldehyde is difficult to detect in alkaline solutions using NMR spectroscopy, requiring alternative methods for detection and quantification. Our results indicate an important step towards understanding the CO reduction mechanism on OD-Cu electrodes.

  4. Acetaldehyde as an intermediate in the electroreduction of carbon monoxide to ethanol on oxide-derived copper

    DOE PAGES

    Bertheussen, Erlend; Verdaguer-Casadevall, Arnau; Ravasio, Davide; ...

    2015-12-21

    Oxide-derived copper (OD-Cu) electrodes exhibit unprecedented CO reduction performance towards liquid fuels, producing ethanol and acetate with >50 % Faradaic efficiency at -0.3 V (vs. RHE). By using static headspace-gas chromatography for liquid phase analysis, we identify acetaldehyde as a minor product and key intermediate in the electroreduction of CO to ethanol on OD-Cu electrodes. Acetaldehyde is produced with a Faradaic efficiency of ≈5 % at -0.33 V (vs. RHE). We show that acetaldehyde forms at low steady-state concentrations, and that free acetaldehyde is difficult to detect in alkaline solutions using NMR spectroscopy, requiring alternative methods for detection and quantification.more » Our results indicate an important step towards understanding the CO reduction mechanism on OD-Cu electrodes.« less

  5. Crystal chemistry of ordered rocksalt-type Ca2NF

    NASA Astrophysics Data System (ADS)

    Al-Azzawi, Mohanad; Zeller, Matthias; Li, Dingqiang; Wagner, Timothy R.

    2017-10-01

    Ordered rocksalt-type Ca2NF has a cubic unit cell that is doubled along [100] relative to the rocksalt-type polymorph due to N/F ordering. Crystals for the present study were prepared from a pure, dry KCuF3 precursor by reaction with Ca metal under nitrogen, and analyzed via high resolution single crystal X-ray diffraction. From this analysis, as well as qualitative compositional analysis using energy dispersive spectroscopy, it was determined that interstitial fluoride ions previously interpreted as Frenkel defects are actually due to a non-stoichiometric defect. The refined composition is Ca2N0.925F1.23, and the ordered cubic phase has space group Fd 3 bar m (No. 227) with a = 10.0301(5) Å and Z = 16.

  6. New insights on the rheological properties of a rocksalt

    NASA Astrophysics Data System (ADS)

    Speranza, G.; Vinciguerra, S.; Di Genova, D.; Romano, C.; Vona, A.; Mollo, S.; Iarocci, A.

    2013-12-01

    The importance and economic interest on rocksalt deposits and salt bodies are well known and extensively studied. The physical and mechanical properties of salt have a profound influence on the tectonics as well as they are considered to be vital for applicative purposes such as mining, petroleum and nuclear waste storage. However, previous scientific works have mainly focused on synthetic rocksalt or commercial salt, whereas natural salt facies have been scarcely investigated. In this view, we present new data on the role of natural heterogeneities (i.e., relative abundance of primary salt crystals and impurities) on the rheological parameters of a rocksalt. This rock belongs to the Saline di Volterra formation (Volterra basin, Tuscany, central Italy) that was deposited during the Messinian Salinity Crisis. The 49-metre-thick salt sequence (intersected by the S1113 borehole of the Solvay company) is characterized by a high salt facies variability. In particular, three end-members have been recognized: the first contains abundant primary salt crystals, with minor or no recrystallizazion; the second member is extensively recrystallized, with scarce primary crystal remnants; the third shows a great abundance of clay impurities. Rheological parameters, such as static and dynamic Young's Modulus and coefficient of linear expansion, were measured for the three rocksalt end-members throughout P and S seismic velocities, uniaxial compressive strength and thermal expansion measurements. Seismic velocity has been measured on cubic samples with a side ranging from 4 to 7 cm. A clear effect of the salt facies was found: the average velocity is faster in mostly recrystallized salt samples (4500 m/s), slower in primary salt-rich samples (4300 m/s), and intermediate (4350 m/s) in presence of clay impurities. Dynamic Young's Modulus calculated on velocities (average value ≈ 38 GPa) mirrors this behavior, with lowest values related to primary salt. The anisotropic effect induced

  7. Infrared spectroscopic and theoretical studies on the reactions of copper atoms with carbon monoxide and nitric oxide molecules in rare-gas matrices.

    PubMed

    Jiang, Ling; Xu, Qiang

    2007-04-12

    Reactions of laser-ablated Cu atoms with CO and NO mixtures in solid argon and neon have been investigated using matrix-isolation infrared spectroscopy. Copper carbonyls and copper nitrosyls have been observed, whereas copper carbonyl nitrosyl complexes are absent from the present experiments. New products, (CuCO)2, [NO]Cu[NO], Cu2(mu2-NO), and Cu(NO)2Cu, have been formed in the copper experiments and characterized using infrared spectroscopy on the basis of the results of the isotopic shifts, mixed isotopic splitting patterns, stepwise annealing, the change of reagent concentration and laser energy, and comparison with theoretical predictions. Density functional theory calculations have been performed on these copper carbonyls and copper nitrosyls, which support the identification of these products from the matrix infrared spectrum. A plausible reaction mechanism has been proposed to account for the formation of copper carbonyls and copper nitrosyls. Similar matrix experiments with Ag and Au produce no new species.

  8. Intrinsic low thermal conductivity in weakly ionic rocksalt structures

    DOE PAGES

    Zhang, Yi; Dong, Jianjun; Kent, Paul R. C.; ...

    2015-07-06

    A fundamental challenge in thermoelectric (TE) material research is meeting the simultaneous requirements of high carrier mobility and low thermal conductivity. Simple crystal structures are ideal for maintaining high carrier mobility, but they usually have high thermal conductivity. In this paper, we show by first-principles lattice dynamics and Boltzmann transport calculations that weakly ionic rocksalt structures exhibit strong lattice anharmonicity and low acoustic-phonon group velocity, which combine to produce intrinsic low thermal conductivity. Finally, we unveil microscopic mechanisms that explain experimental observations and provide insights for TE material design and discovery.

  9. Maximum probability domains in crystals: the rock-salt structure.

    PubMed

    Causà, Mauro; Savin, Andreas

    2011-11-17

    The present paper studies MX crystals in rock-salt structure (M: Li, Na, K; X: F, Cl, Br, I). They are often described as being formed by ions. Pictures based on quantum mechanical calculations sustain and quantify it. The tools used are (i) the Quantum Theory of Atoms in Molecules, (ii) the Electron Localization Function, and (iii) the maximization of the probability to find in a spatial domain a number of electrons equal to that of the ion under consideration. The present paper shows that the images provided by these three different tools to analyze the quantum mechanical calculations yield, for these systems, very similar results, in the sense that the spatial domains and probability distributions are close. While results for the first two methods are already present in the literature, the last of the methods is applied for the first time to these systems, and details about the method of calculation and program are also given.

  10. Waste disposal in a German rock-salt mine

    SciTech Connect

    Wegener, W. )

    1993-04-01

    A worked-out area of the operating Helibronn rock-salt mine is being used as a repository for fly-ash waste from incineration plants. The waste is packed in large bags, handled by fork-lifts, trucks, and cranes, and stacked 11-m-high. In addition insolubles from the re-saturation of brine for electrolysis using rock salt are stowed in bulk. Special care is taken to isolate waste-disposal activities from the salt mining and hoisting operations. Considerable interest is being shown in the underground disposal of waste in Germany, particularly as existing landfill sites are approaching the end of their lives and the establishment of new sites is meeting strong opposition from local populations. The problems encountered in the disposal of fly ash in salt mines are discussed.

  11. Copper

    Integrated Risk Information System (IRIS)

    Copper ; CASRN 7440 - 50 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effects )

  12. Carbon monoxide binding to the heme group at the dimeric interface modulates structure and copper accessibility in the Cu,Zn superoxide dismutase from Haemophilus ducreyi: in silico and in vitro evidences.

    PubMed

    Chillemi, Giovanni; De Santis, Serena; Falconi, Mattia; Mancini, Giordano; Migliorati, Valentina; Battistoni, Andrea; Pacello, Francesca; Desideri, Alessandro; D'Angelo, Paola

    2012-01-01

    X-ray absorption near-edge structure (XANES) spectroscopy and molecular dynamics (MD) simulations have been jointly applied to the study of the Cu,Zn superoxide dismutase from Haemophilus ducreyi (HdSOD) in interaction with the carbon monoxide molecule. The configurational flexibility of the Fe(II)-heme group, intercalated between the two subunits, has been sampled by MD simulations and included in the XANES data analysis without optimization in the structural parameter space. Our results provide an interpretation of the observed discrepancy in the Fe-heme distances as detected by extended X-ray absorption fine structure (EXAFS) spectroscopy and the classical XANES analysis, in which the structural parameters are optimized in a unique structure. Moreover, binding of the CO molecule to the heme induces a long range effect on the Cu,Zn active site, as evidenced by both MD simulations and in vitro experiments. MD simulation of the CO bound system, in fact, highlighted a structural rearrangement of the protein-protein hydrogen bond network in the region of the Cu,Zn active site, correlated with an increase in water accessibility at short distance from the copper atom. In line, in vitro experiments evidenced an increase of copper accessibility to a chelating agent when the CO molecule binds to the heme group, as compared to a heme deprived HdSOD. Altogether, our results support the hypothesis that the HdSOD is a heme-sensor protein, in which binding to small gaseous molecules modulates the enzyme superoxide activity as an adaptive response to the bacterial environment.

  13. Instrumental carbon monoxide dosimetry.

    PubMed

    Stetter, J R; Rutt, D R

    1980-10-01

    Modern technology for the ambient monitoring of carbon monoxide has been developed to produce a portable electrochemical instrument capable of the personal exposure to carbon monoxide. The performance characteristics of this device have been studied so that the unambiguous interpretation of field data could be performed. A study of the carbon monoxide exposure in a light manufacturing facility illustrate that effective dosimetry can be performed with expectations of accuracy typically better than +/- 15%, and that voluntary carbon monoxide exposures such as smoking were a significant contribution to the individual's exposure. Significant definition of the carbon monoxide exposure profile can be achieved with an instrument approach to the collection of the dosimetric data.

  14. Strained rocksalt ScN: ab initio studies of electronic structure and lattice-dynamical properties

    NASA Astrophysics Data System (ADS)

    Ahmad, Sohail; Bouarissa, Nadir

    2017-05-01

    Generalized gradient approximation calculations are performed to determine electronic and lattice vibration properties of unstrained and strained rocksalt scandium nitride (ScN). In agreement with earlier studies, our results reveal that unstrained rocksalt ScN is an indirect gap semiconductor from the valence band at Γ point to the conduction band at the X point. The effect of strain is found to have a large variation of energy band gaps and optical phonon frequencies. A large longitudinal and transverse optical phonon frequencies splitting is noted for the material of interest suggesting thus a remarkable dynamic ionicity of rocksalt ScN which varies significantly when ScN is strained. This can lead to engineering novel behaviors and holds promise for new technological applications.

  15. Reactions of monodithiolene tungsten(VI) sulfido complexes with copper(I) in relation to the structure of the active site of carbon monoxide dehydrogenase.

    PubMed

    Groysman, Stanislav; Majumdar, Amit; Zheng, Shao-Liang; Holm, R H

    2010-02-01

    Reactions directed at the synthesis of structural analogues of the active site of molybdenum-containing carbon monoxide dehydrogenase have been investigated utilizing [WO(2)S(bdt)](2-) (1) and [WOS(2)(bdt)](2-) (2) and sterically hindered [Cu(R)L] or [Cu(SSiR'(3))(2)](-) as reactants. All successful reactions of 2 afford the binuclear W(VI)/Cu(I) products [WO(bdt)(mu(2)-S)(2)Cu(L)](2-/-) with L = carbene (3), Ar*S (4), Ar* (7), SSiR(3) (R = Ph (5), Pr(i) (6)). Similarly, [W(bdt)(OSiPh(3))S(2)](-) leads to [W(bdt)(OSiPh(3))(mu(2)-S)(2)Cu(SAr*)](-) (8). These complexes, with apical oxo and basal dithiolato and sulfido coordination (excluding 8), terminal thiolate ligation at Cu(I) (4-6, 8), and W-(mu(2)-S)-Cu bridging, bear a structural resemblance to the enzyme site. Differences include two bridges instead of one and the absence of basal oxo/hydroxo ligation. Complex 8 differs from the others by utilizing apical and basal sulfido ligands in bridge formation. Related reaction systems based on 1 gave 4 in small yield or product mixtures in which the desired monobridged complex [WO(2)(bdt)(mu(2)-S)Cu(R)](2-) was not detected. Mass spectrometric analysis of the reaction system with L = carbene suggests that any monobridged species forms may converted to the dibridged form by disproportionation. In these experiments, the use of W(VI) preserves the structural integrity of Mo(VI), whose analogues of 1 and 2 have not been isolated. (Ar* = 2,6-bis(2,4,6-triisopropylphenyl)phenyl, bdt = benzene-1,2-dithiolate(2-)).

  16. Permeability Development at Layer Interfaces in Bedded Rocksalt

    NASA Astrophysics Data System (ADS)

    Muhammad, N.; Spiers, C. J.; Peach, C. J.; De Bresser, J. H. P.; Liu, W.

    2016-12-01

    Solution mined salt caverns are of great interest for storage of fluids such as compressed air, natural gas or hydrogen fuel, and are expected to show excellent healing and sealing capacity. However, it is of utmost importance to be able to reliably quantify the permeability of salt cavern walls, so that potential loss of the stored asset may be assessed. Data on dilatancy, permeability and damage development are readily available for pure rocksalt undergoing deformation, but little is known about the permeability development at the bedding interfaces within layered salt under varying differential stresses. Layered salt samples were obtained from the walls of a pilot well in Hubei province China. The natural salt shows alternating layers of rock salt, anhydrite, mudstone and glauberite. Cylindrical samples, 50 mm diameter and 85 mm long, were prepared with layer interfaces oriented vertical, horizontal or obliquely to the core axis. Tests were conducted at room temperature and a confining pressure of 20 and (for shallower depth) 10 MPa, representing in-situ conditions. Axial deformation was performed using a triaxial machine in the HPT-laboratory at Utrecht. Compaction/dilation was measured using a servo control dilatometer for confining pressure control, and, in conjunction, the permeability was measured using Argon gas transient step permeameter. The samples were deformed at a constant displacement rate of 1 µm/s. After reaching 10, 20 and 30 MPa differential stress, deformation was halted and permeability was measured parallel to the compositional interfaces for each of the three geometries. Overall, it was found that during deformation, no shear slippage occurred at interface and the bulk permeability of most specimens decreased, where the absolute permeability value (found in the range 10-15 to <10-21 m2) depending upon the orientation of the bedding interface and composition of the sample. All samples showed a decrease in volume with axial strain

  17. Carbon monoxide sensor and method of use

    DOEpatents

    Dutta, Prabir K.; Swartz, Scott L.; Holt, Christopher T.; Revur, Ramachandra Rao

    2006-01-10

    A sensor and method of use for detection of low levels of carbon monoxide in gas mixtures. The approach is based on the change in an electrical property (for example: resistance) that occurs when carbon monoxide is selectively absorbed by a film of copper chloride (or other metal halides). The electrical property change occurs rapidly with both increasing and decreasing CO contents, varies with the amount of CO from the gas stream, and is insensitive to the presence of hydrogen. To make a sensor using this approach, the metal halide film will deposited onto an alumina substrate with electrodes. The sensor may be maintained at the optimum temperature with a thick film platinum heater deposited onto the opposite face of the substrate. When the sensor is operating at an appropriate (and constant) temperature, the magnitude of the electrical property measured between the interdigital electrodes will provide a measure of the carbon monoxide content of the gas.

  18. Vacancy Structures and Melting Behavior in Rock-Salt GeSbTe.

    PubMed

    Zhang, Bin; Wang, Xue-Peng; Shen, Zhen-Ju; Li, Xian-Bin; Wang, Chuan-Shou; Chen, Yong-Jin; Li, Ji-Xue; Zhang, Jin-Xing; Zhang, Ze; Zhang, Sheng-Bai; Han, Xiao-Dong

    2016-05-03

    Ge-Sb-Te alloys have been widely used in optical/electrical memory storage. Because of the extremely fast crystalline-amorphous transition, they are also expected to play a vital role in next generation nonvolatile microelectronic memory devices. However, the distribution and structural properties of vacancies have been one of the key issues in determining the speed of melting (or amorphization), phase-stability, and heat-dissipation of rock-salt GeSbTe, which is crucial for its technological breakthrough in memory devices. Using spherical aberration-aberration corrected scanning transmission electron microscopy and atomic scale energy-dispersive X-ray mapping, we observe a new rock-salt structure with high-degree vacancy ordering (or layered-like ordering) at an elevated temperature, which is a result of phase transition from the rock-salt phase with randomly distributed vacancies. First-principles calculations reveal that the phase transition is an energetically favored process. Moreover, molecular dynamics studies suggest that the melting of the cubic rock-salt phases is initiated at the vacancies, which propagate to nearby regions. The observation of multi-rock-salt phases suggests another route for multi-level data storage using GeSbTe.

  19. Vacancy structures and melting behavior in rock-salt GeSbTe

    SciTech Connect

    Zhang, Bin; Wang, Xue -Peng; Shen, Zhen -Ju; Li, Xian -Bin; Wang, Chuan -Shou; Chen, Yong -Jin; Li, Ji -Xue; Zhang, Jin -Xing; Zhang, Ze; Zhang, Sheng -Bai; Han, Xiao -Dong

    2016-05-03

    Ge-Sb-Te alloys have been widely used in optical/electrical memory storage. Because of the extremely fast crystalline-amorphous transition, they are also expected to play a vital role in next generation nonvolatile microelectronic memory devices. However, the distribution and structural properties of vacancies have been one of the key issues in determining the speed of melting (or amorphization), phase-stability, and heat-dissipation of rock-salt GeSbTe, which is crucial for its technological breakthrough in memory devices. Using spherical aberration-aberration corrected scanning transmission electron microscopy and atomic scale energy-dispersive X-ray mapping, we observe a new rock-salt structure with high-degree vacancy ordering (or layered-like ordering) at an elevated temperature, which is a result of phase transition from the rock-salt phase with randomly distributed vacancies. First-principles calculations reveal that the phase transition is an energetically favored process. Furthermore, molecular dynamics studies suggest that the melting of the cubic rock-salt phases is initiated at the vacancies, which propagate to nearby regions. The observation of multi-rock-salt phases suggests another route for multi-level data storage using GeSbTe.

  20. Vacancy structures and melting behavior in rock-salt GeSbTe

    DOE PAGES

    Zhang, Bin; Wang, Xue -Peng; Shen, Zhen -Ju; ...

    2016-05-03

    Ge-Sb-Te alloys have been widely used in optical/electrical memory storage. Because of the extremely fast crystalline-amorphous transition, they are also expected to play a vital role in next generation nonvolatile microelectronic memory devices. However, the distribution and structural properties of vacancies have been one of the key issues in determining the speed of melting (or amorphization), phase-stability, and heat-dissipation of rock-salt GeSbTe, which is crucial for its technological breakthrough in memory devices. Using spherical aberration-aberration corrected scanning transmission electron microscopy and atomic scale energy-dispersive X-ray mapping, we observe a new rock-salt structure with high-degree vacancy ordering (or layered-like ordering) atmore » an elevated temperature, which is a result of phase transition from the rock-salt phase with randomly distributed vacancies. First-principles calculations reveal that the phase transition is an energetically favored process. Furthermore, molecular dynamics studies suggest that the melting of the cubic rock-salt phases is initiated at the vacancies, which propagate to nearby regions. The observation of multi-rock-salt phases suggests another route for multi-level data storage using GeSbTe.« less

  1. Vacancy Structures and Melting Behavior in Rock-Salt GeSbTe

    PubMed Central

    Zhang, Bin; Wang, Xue-Peng; Shen, Zhen-Ju; Li, Xian-Bin; Wang, Chuan-Shou; Chen, Yong-Jin; Li, Ji-Xue; Zhang, Jin-Xing; Zhang, Ze; Zhang, Sheng-Bai; Han, Xiao-Dong

    2016-01-01

    Ge-Sb-Te alloys have been widely used in optical/electrical memory storage. Because of the extremely fast crystalline-amorphous transition, they are also expected to play a vital role in next generation nonvolatile microelectronic memory devices. However, the distribution and structural properties of vacancies have been one of the key issues in determining the speed of melting (or amorphization), phase-stability, and heat-dissipation of rock-salt GeSbTe, which is crucial for its technological breakthrough in memory devices. Using spherical aberration-aberration corrected scanning transmission electron microscopy and atomic scale energy-dispersive X-ray mapping, we observe a new rock-salt structure with high-degree vacancy ordering (or layered-like ordering) at an elevated temperature, which is a result of phase transition from the rock-salt phase with randomly distributed vacancies. First-principles calculations reveal that the phase transition is an energetically favored process. Moreover, molecular dynamics studies suggest that the melting of the cubic rock-salt phases is initiated at the vacancies, which propagate to nearby regions. The observation of multi-rock-salt phases suggests another route for multi-level data storage using GeSbTe. PMID:27140674

  2. Accidental carbon monoxide poisoning.

    PubMed

    Zeller, W P; Miele, A; Suarez, C; Hannigan, J; Hurley, R M

    1984-12-01

    In this case report of an accidental automobile carbon monoxide poisoning, we identify the following risk factors: freezing temperature, young passenger age, location in the rear of the auto, smaller patient mass, and auto disrepair. The pathogenesis of carbon monoxide poisoning is reviewed. Emergency treatment and suggested criteria for hyperbaric oxygen use in pediatric patients are discussed.

  3. Novel superstructure of the rocksalt type and element distribution in germanium tin antimony tellurides

    SciTech Connect

    Rosenthal, Tobias; Welzmiller, Simon; Neudert, Lukas; Urban, Philipp; Fitch, Andy; Oeckler, Oliver

    2014-11-15

    A superstructure of the rocksalt-type observed in quenched CVT-grown single crystals of Ge{sub 3.25(7)}Sn{sub 1.10(3)}Sb{sub 1.10(3)}Te{sub 6} was elucidated by X-ray diffraction using fourfold twinned crystals (space group P3{sup ¯}m1, a=4.280(1) Å, c=20.966(3) Å). The structure is built up of distorted rocksalt-type building blocks typical for long-range ordered GST materials and substitution variants thereof. In contrast to those phases, an exclusive ABC-type cubic stacking sequence of the Te-atom layers is present. High-resolution electron microscopy reveals spheroidal domains with this structure (average diameter 25 nm) whose stacking direction is perpendicular to the 〈1 1 1〉 directions of the basic rocksalt-type structure. Additional slab-like domains with a lateral extension up to 1 µm occasionally result in a hierarchical structure motif. Due to the similar electron counts of the elements involved, resonant diffraction was used in order to elucidate the element distribution in rocksalt-type building blocks of the stable layered compound 39R-Ge{sub 3}SnSb{sub 2}Te{sub 7} (R3{sup ¯}m, a=4.24990(4) Å, c=73.4677(9) Å). Sb tends to occupy the atom site close to the van der Waals gaps while Ge concentrates in the center of the building blocks. - Graphical abstract: High-resolution transmission electron micrograph, SAED pattern and reciprocal lattice section of X-ray single crystal data of Ge{sub 3.25}Sn{sub 1.1}Sb{sub 1.1}Te{sub 6} with an 11P-type superstructure of the rocksalt type. - Highlights: • A novel superstructure of the rocksalt-type in the system Ge–Sn–Sb–Te is elucidated. • It combines the cubic stacking of the HT phase with building blocks of the RT phase. • It indicates the ordering mechanism during the phase transition of GST materials. • A hierarchical structure motif is promising with respect to the reduction of κ{sub L}. • Resonant diffraction reveals the element distribution in 39R-Ge{sub 3}SnSb{sub 2}Te{sub 7}.

  4. Disordered lithium niobate rock-salt materials prepared by hydrothermal synthesis.

    PubMed

    Modeshia, Deena R; Walton, Richard I; Mitchell, Martin R; Ashbrook, Sharon E

    2010-07-14

    An investigation of the one-step hydrothermal crystallisation of lithium niobates reveals that reaction between Nb(2)O(5) and aqueous LiOH at 240 degrees C yields materials with a disordered rock-salt structure where the metals are statistically distributed over the cation sites. This contrasts with the well-studied reaction between Nb(2)O(5) and NaOH or KOH that produces ANbO(3) (A = Na, K) perovskites. Powder neutron diffraction shows that materials prepared at short reaction times and lower LiOH concentration (2.5 M) are lithium deficient and have a slight excess of niobium, but that at longer periods of reaction in 5 M LiOH, close to the ideal, stoichiometric Li(0.75)Nb(0.25)O composition is produced. Upon annealing this phase cleanly transforms into the known ordered rock-salt material Li(3)NbO(4), a process we have followed using thermodiffractometry, which indicates that transformation begins at approximately 700 degrees C. Solid-state (93)Nb and (7)Li NMR of the disordered and ordered rock-salt phases shows that both contain single metal sites but there is clear evidence for local disorder in the disordered samples. For the ordered material, NMR parameters derived from experiment are also compared to those calculated using density functional theory and are shown to be in good agreement.

  5. Carbon Monoxide Poisoning

    MedlinePlus

    ... related Carbon Monoxide Exposures Additional Resources Quick Links Air Pollution & Respiratory Health Air Quality Asthma Mold What's New ... KB] Tiếng Việt [PDF - 89 KB] Quick Links Air Pollution & Respiratory Health Air Quality Asthma Mold What's New ...

  6. Carbon monoxide intoxication

    SciTech Connect

    Kales, S.N. )

    1993-11-01

    Carbon monoxide poisoning usually results from inhalation of exhaust fumes from motor vehicles, smoke from fires or fumes from faulty heating systems. Carbon monoxide has a high affinity for hemoglobin, with which it forms carboxyhemoglobin. The resulting decrease in both oxygen-carrying capacity and oxygen release can lead to end-organ hypoxia. The clinical presentation is nonspecific. Headache, dizziness, fatigue and nausea are common in mild to moderate carbon monoxide poisoning. In more severe cases, tachycardia, tachypnea and central nervous system depression occur. When carbon monoxide intoxication is suspected, empiric treatment with 100 percent oxygen should be initiated immediately. The diagnosis is confirmed by documenting an elevated carboxyhemoglobin level. Hyperbaric oxygen therapy is recommended in patients with neurologic dysfunction, cardiac dysfunction or a history of unconsciousness. 26 refs.

  7. Carbon Monoxide Safety

    MedlinePlus

    ... Media Fire Protection Technology Carbon monoxide safety outreach materials Keep your community informed about the dangers of ... muscular coordination Loss of consciousness Ultimately death Outreach materials from the U.S. Fire Administration Handout: portable generators ...

  8. Estimating carbon monoxide exposure

    NASA Technical Reports Server (NTRS)

    Edgerley, R. H.

    1971-01-01

    Method predicts effects of carbon monoxide on astronauts confined in spacecraft cabin atmospheres. Information on need for low toxicity level also applies to confined spaces. Benefits are applicable to industry and public health.

  9. Ground motions induced by a producing hydrocarbon reservoir that is overlain by a viscoelastic rocksalt layer: a numerical model

    NASA Astrophysics Data System (ADS)

    Marketos, G.; Govers, R.; Spiers, C. J.

    2015-10-01

    Hydrocarbon reservoir pressure depletion leads to stress changes inside the reservoir and ground deformation which is registered at the surface as subsidence. As reservoirs are often overlain by layers of rocksalt (or other evaporites), which are materials that flow so as to relax stresses inside them, there is the potential for time-varying surface subsidence. This work focuses on understanding the macroscopic mechanisms that lead to rocksalt flow-induced ground displacements. A Finite Element Model is used for this purpose in which the rocksalt layer is represented by a viscoelastic Maxwell material. Two distinct mechanisms that lead to displacement are observed. These are active during different stages of the deformation and have different timescales associated with them. An important observation is that the timescale for deformation that is measured at the ground surface is not equal to the timescale for deformation of a viscoelastic material element, but can be many times larger than that. The sensitivity of the response to the thickness and location of the rocksalt layer is also presented. Conclusions are drawn which allow for the relative importance of the presence of the rocksalt layer to be assessed and for a framework for understanding time-dependent subsidence above producing hydrocarbon reservoirs to be developed. Finally the changes in stress distribution around a producing reservoir are also briefly discussed.

  10. High temperature thermoelectric properties of rock-salt structure PbS

    DOE PAGES

    Parker, David S.; Singh, David J.

    2013-12-18

    We present an analysis of the high temperature transport properties of rock-salt structure PbS, a sister compound to the better studied lead chalcogenides PbSe and PbTe. In this study, we find thermopower magnitudes exceeding 200 V/K in a wide doping range for temperatures of 800 K and above. Based on these calculations, and an analysis of recent experimental work we find that this material has a potential for high thermoelectric performance. Also, we find favorable mechanical properties, based on an analysis of published data.

  11. High temperature thermoelectric properties of rock-salt structure PbS

    SciTech Connect

    Parker, David S.; Singh, David J.

    2013-12-18

    We present an analysis of the high temperature transport properties of rock-salt structure PbS, a sister compound to the better studied lead chalcogenides PbSe and PbTe. In this study, we find thermopower magnitudes exceeding 200 V/K in a wide doping range for temperatures of 800 K and above. Based on these calculations, and an analysis of recent experimental work we find that this material has a potential for high thermoelectric performance. Also, we find favorable mechanical properties, based on an analysis of published data.

  12. Transmissivity of carbon monoxide

    NASA Technical Reports Server (NTRS)

    Drayson, S. R.; Tallamraju, R.; Chaney, L. W.

    1973-01-01

    The line strengths and self- and nitrogen-broadened half widths for selected lines of the 4.6 micron fundamental band of carbon monoxide were determined. The band strength determined at stp. is higher than previously reported measurements. The half widths agree well with other measurements and calculations.

  13. Observation of laser-induced stress waves and mechanism of structural changes inside rock-salt crystals.

    PubMed

    Sakakura, Masaaki; Tochio, Takaya; Eida, Masaaki; Shimotsuma, Yasuhiko; Kanehira, Shingo; Nishi, Masayuki; Miura, Kiyotaka; Hirao, Kazuyuki

    2011-08-29

    The structural changes inside rock-salt crystals after femtosecond (fs) laser irradiation are investigated using a microscopic pump-probe technique and an elastic simulation. The pump-probe imaging shows that a squircle-shaped stress wave is generated after the fs laser irradiation as a result of the relaxation of thermal stress in the photoexcited region. Pump-probe crossed-Nicols imaging and elastic simulation elucidate that shear stresses and tensile stresses are concentrated in specific regions during the propagation of the stress wave. The shear stresses and tensile stresses observed in this study can explain the characteristic laser-induced structural changes inside rock-salt crystals.

  14. Solid State Carbon Monoxide Sensor

    NASA Technical Reports Server (NTRS)

    Upchurch, Billy T. (Inventor); Wood, George M. (Inventor); Schryer, David R. (Inventor); Leighty, Bradley D. (Inventor); Oglesby, Donald M. (Inventor); Kielin, Erik J. (Inventor); Brown, Kenneth G. (Inventor); DAmbrosia, Christine M. (Inventor)

    1999-01-01

    A means for detecting carbon monoxide which utilizes an un-heated catalytic material to oxidize carbon monoxide at ambient temperatures. Because this reaction is exothermic, a thermistor in contact with the catalytic material is used as a sensing element to detect the heat evolved as carbon monoxide is oxidized to carbon dioxide at the catalyst surface, without any heaters or external heating elements for the ambient air or catalytic element material. Upon comparison to a reference thermistor, relative increases in the temperature of the sensing thermistor correspond positively with an increased concentration of carbon monoxide in the ambient medium and are thus used as an indicator of the presence of carbon monoxide.

  15. Optical properties, structural parameters, and bonding of highly textured rocksalt tantalum nitride films

    SciTech Connect

    Matenoglou, G. M.; Koutsokeras, L. E.; Lekka, Ch. E.; Patsalas, P.; Abadias, G.; Camelio, S.; Evangelakis, G. A.; Kosmidis, C.

    2008-12-15

    Tantalum nitride is an interesting solid with exceptional properties and it might be considered as a representative model system of the d{sup 3}s{sup 2} transition metal nitrides. In this work highly textured, stoichiometric, rocksalt TaN(111) films have been grown on Si(100) by pulsed laser deposition. The films were under a triaxial stress, which has been determined by the sin{sup 2} {psi} method. The stress-free lattice parameter was found to be 0.433{+-}0.001 nm, a value which has been also determined by ab initio calculations within the local spin density approximation. The optical properties of TaN have been studied using spectroscopic ellipsometry and detailed band structure calculations. The electron conductivity of TaN is due to the Ta 5dt{sub 2g} band that intercepts the Fermi level and is the source of intraband absorption. The plasma energies of fully dense rocksalt TaN were found to be 9.45 and 9.7 eV based on the experimental results and ab initio calculations, respectively. Additional optical absorption bands were also observed around 1.9 and 7.3 eV and attributed to be due to crystal field splitting of the Ta 5d band (t{sub 2g}{yields}e{sub g} transition) and the N p{yields}Ta d interband transition, respectively.

  16. Ordered rock-salt related nanoclusters in CaMnO2.

    PubMed

    Varela, Aurea; de Dios, Susana; Parras, Marina; Hernando, María; Fernández-Díaz, M Teresa; Landa-Cánovas, Angel R; González-Calbet, José M

    2009-06-24

    Oxygen engineering techniques performed under adequate controlled atmosphere show that the CaMnO(3)-CaMnO(2) topotactic reduction-oxidation process proceeds via oxygen diffusion while the cationic sublattice remains almost unaltered. Extra superlattice reflections in selected area electron diffraction patterns indicate doubling of the CaMnO(2) rock-salt cell along the cubic directions of a distorted rhombohedral cell originated by ordering of Ca(2+) and Mn(2+) ions distributed in nanoclusters into a NaCl-type matrix, as evidenced by dark field electron microscope images. The local nature of the information provided by the transmission electron microscopy techniques used to characterize the rock-salt type Ca(1-x)Mn(x)O(2) solid solution clearly hints at the existence of subtle extra ordering in other upper oxides of the Ca-Mn-O system. The combination of local characterization techniques like electron microscopy with more average ones like powder X-ray and neutron diffraction allows a very complete characterization of the system.

  17. Thermoelastic properties of rock-salt NaCl at high pressures and temperatures

    NASA Astrophysics Data System (ADS)

    Santos, M. L. M.; Shukla, G.; Wentzcovitch, R. M.

    2014-12-01

    Rock-salt NaCl is an important mineral in our daily lives, in high pressure science/technology, and in the oil/gas industry. The latter has come to prominence since the discovery of deep water pre-salt structures containing great hydrocarbon reserves out of the SE coast of Brazil. The unique aspects of these regions, such as deep water (greater than 2 km below sea level) and deep hydrocarbon reserves (more than 5 km deep) are challenging for oil/gas explorations. Oil/gas field imaging algorithms require good velocity models for seismic wave-propagation within the salt layer. Despite its importance, there is still insufficient information on the elasticity of and sound velocities in NaCl at relevant P,T conditions. Here we report such properties in rock-salt NaCl at relevant P,T conditions as obtained by first principles (DFT) quasiharmonic calculations. We compare intermediate and final results with available experimental data on thermodynamics and thermoelastic properties and combine them for optimum accuracy. These results should be useful for and facilitate imaging pre-salt hydrocarbon reserves. Research supported by CAPES from Brazil, NSF/DMR, and NSF/EAR.

  18. Electronic structures of rocksalt, litharge, and herzenbergite SnO by density functional theory

    NASA Astrophysics Data System (ADS)

    Walsh, Aron; Watson, Graeme W.

    2004-12-01

    Density functional theory calculations have been performed on SnO in the litharge, herzenbergite, and rocksalt crystal structures. An asymmetric electron distribution was found around the Sn atoms in litharge and herzenbergite SnO which could be ascribed to a Sn5s2 sterically active “lone pair.” Analysis of the electronic structure shows that the states responsible for the asymmetric Sn electron distribution are due to the coupling of unfilled Sn(5p) with the antibonding combination arising from interaction of Sn(5s) and O(2p) . The coupling of Sn(5p) was found to be active in both the formation of the asymmetric density and the stabilization of the litharge and herzenbergite phases. Due to the symmetry of the interaction the coupling of Sn(5p) with the antibonding states can only take place on distorted Sn sites, explaining the absence of an asymmetry in the rocksalt structure. In contrast to the classical view that the Sn(II) “lone pair” forms directly through hybridization of Sn5s and 5p , our calculations confirm for the first time, through COOP analysis, that it is only through the interaction of the oxygen 2p states that formation of the asymmetric density is achieved.

  19. Carbon Monoxide Targeting Mitochondria

    PubMed Central

    Queiroga, Cláudia S. F.; Almeida, Ana S.; Vieira, Helena L. A.

    2012-01-01

    Mitochondria present two key roles on cellular functioning: (i) cell metabolism, being the main cellular source of energy and (ii) modulation of cell death, by mitochondrial membrane permeabilization. Carbon monoxide (CO) is an endogenously produced gaseoustransmitter, which presents several biological functions and is involved in maintaining cell homeostasis and cytoprotection. Herein, mitochondrion is approached as the main cellular target of carbon monoxide (CO). In this paper, two main perspectives concerning CO modulation of mitochondrial functioning are evaluated. First, the role of CO on cellular metabolism, in particular oxidative phosphorylation, is discussed, namely, on: cytochrome c oxidase activity, mitochondrial respiration, oxygen consumption, mitochondrial biogenesis, and general cellular energetic status. Second, the mitochondrial pathways involved in cell death inhibition by CO are assessed, in particular the control of mitochondrial membrane permeabilization. PMID:22536507

  20. Analysis of carbon monoxide.

    PubMed

    Widdop, Brian

    2002-07-01

    The degree of exposure to carbon monoxide is most often assessed by measuring the blood carboxyhaemoglobin saturation. This measurement is relevant to investigations of acute accidental or deliberate poisoning and of chronic exposure in a domestic or work place environment. Simple spectrophotometric methods based on differential protein precipitation or dithionite reduction are prone to interference from other haemoglobin pigments and are imprecise for low-level estimations. Automated spectrophotometric devices (CO-oximeters) that estimate simultaneously total haemoglobin, percentage oxyhaemoglobin and percentage carboxyhaemoglobin have acceptable accuracy for carboxyhaemoglobin saturation levels of > 5% and are recommended for most clinical purposes. For the investigation of low-level exposure and the detection of increased haemolysis in neonates, more sensitive methods involving the release of carbon monoxide and its measurement by gas chromatography are required. Gas chromatographic methods are also appropriate when examining post-mortem blood samples where putrefaction or heat stress has resulted in a significant change in haemoglobin composition.

  1. Modeling the (Sub)surface Deformation Field Evolution Due to Production from a Hydrocarbon Reservoir Overlain by Rocksalt

    NASA Astrophysics Data System (ADS)

    Marketos, G.; Govers, R. M. A.; Spiers, C. J.

    2014-12-01

    Rocksalt is an important caprock for sealing or trapping hydrocarbons. Given its relatively low viscosity, it may flow during and after production and result in time-dependent surface deformation. To predict the consequences of alternative production strategies, we seek to understand the primary controls on stress-driven flow and surface deformation of hydrocarbon extraction from a reservoir topped by rocksalt. The mechanical properties of rock salt are a key influence, but complicated. Depending on grain size, temperature, and stress, salt can deform mainly elastically, by power law viscous creep, and/or by linear viscous diffusion creep. In this study, we evaluate the evolution of production induced deformation using generic geo-mechanical models. Our strategy is to start with simplified geometries, rheologies, and forcing, and to increase model complexity slowly. Our results show that there are two distinctly different time scales that dominate the evolution of the models: short term subsidence and longer term partial rebound. The shortest time scale corresponds to stress-driven flow in the vicinity of the reservoir. The longest time scale is controlled by resistance to viscous flow and stress relaxation within a wider region of the rocksalt layer. We discuss the sensitivity to the thickness of the rocksalt seal, the geometry of the reservoir, and the distance between the source and the seal.

  2. Relating natural heterogeneities and rheological properties of rocksalt: New insights from microstructural observations and petrophyisical parameters on Messinian halites from the Italian Peninsula

    NASA Astrophysics Data System (ADS)

    Speranza, Giulio; Vona, Alessandro; Vinciguerra, Sergio; Romano, Claudia

    2016-01-01

    The importance and economic interest of rocksalt as well as its influence on tectonics and applicative purposes such as mining, hydrocarbons extraction, and nuclear waste storage are well known. Careful characterization of physical and chemical properties of rocksalt is fundamental as the rocksalt behavior may influence its potential use for applicative purposes. Mechanical and rheological properties of rocksalt have been extensively studied in the past. However, the role of natural heterogeneities within rocksalt and their effect on salt rheology have not been investigated quantitatively. Here we present a comprehensive salt facies study on Messinian rocksalt from several Italian sites (Volterra Basin, Tuscany, Caltanissetta Basin, Sicily and Crotone Basin, Calabria). Four salt facies end members have been identified and analyzed by optical analyses. The main facies-defining characteristics resulted to be the primary salt crystal abundance, crystal size, roundness and orientation, as well as the clay inclusion contents. Three out of four facies were placed on an evolutionary path from an "immature," with respect to the deformation history, to a "mature," rocksalt. So we observed, with increasing rocksalt maturity, a progressive disappearing of primary crystal remnants, increasing crystals elongation and iso-orientation and decreasing in crystal size. This trend has been confirmed by differential stress calculation from subgrain size. Through seismic waves velocity measurements and uniaxial compressive runs, specific salt facies were tested. Results of the investigations demonstrate that the facies parameters have a distinct influence on the rocksalt petrophysical parameters like P- and S-waves velocity, dynamic and static Young Modulus, elastic limit, and strain at peak. Finally, this study allowed to suggest the subdivision of Volterra's salt sequence in three different units that have been subjected to variable deformation degree in response to the different

  3. Controlling spin-dependent tunneling by bandgap tuning in epitaxial rocksalt MgZnO films

    SciTech Connect

    Li, D. L.; Ma, Q. L.; Wang, S. G.; Ward, R. C. C.; Hesjedal, T.; Zhang, X. -G.; Kohn, A.; Amsellem, E.; Yang, G.; Liu, J. L.; Jiang, J.; Wei, H. X.; Han, X. F.

    2014-12-02

    Widespread application of magnetic tunnel junctions (MTJs) for information storage has so far been limited by the complicated interplay between tunnel magnetoresistance (TMR) ratio and the product of resistance and junction area (RA). An intricate connection exists between TMR ratio, RA value and the bandgap and crystal structure of the barrier, a connection that must be unravelled to optimise device performance and enable further applications to be developed. In this paper, we demonstrate a novel method to tailor the bandgap of an ultrathin, epitaxial Zn-doped MgO tunnel barrier with rocksalt structure. This structure is attractive due to its good Δ1 spin filtering effect, and we show that MTJs based on tunable MgZnO barriers allow effective balancing of TMR ratio and RA value. Finally, in this way spin-dependent transport properties can be controlled, a key challenge for the development of spintronic devices.

  4. Controlling spin-dependent tunneling by bandgap tuning in epitaxial rocksalt MgZnO films

    DOE PAGES

    Li, D. L.; Ma, Q. L.; Wang, S. G.; ...

    2014-12-02

    Widespread application of magnetic tunnel junctions (MTJs) for information storage has so far been limited by the complicated interplay between tunnel magnetoresistance (TMR) ratio and the product of resistance and junction area (RA). An intricate connection exists between TMR ratio, RA value and the bandgap and crystal structure of the barrier, a connection that must be unravelled to optimise device performance and enable further applications to be developed. In this paper, we demonstrate a novel method to tailor the bandgap of an ultrathin, epitaxial Zn-doped MgO tunnel barrier with rocksalt structure. This structure is attractive due to its good Δ1more » spin filtering effect, and we show that MTJs based on tunable MgZnO barriers allow effective balancing of TMR ratio and RA value. Finally, in this way spin-dependent transport properties can be controlled, a key challenge for the development of spintronic devices.« less

  5. Controlling spin-dependent tunneling by bandgap tuning in epitaxial rocksalt MgZnO films

    PubMed Central

    Li, D. L.; Ma, Q. L.; Wang, S. G.; Ward, R. C. C.; Hesjedal, T.; Zhang, X.-G.; Kohn, A.; Amsellem, E.; Yang, G.; Liu, J. L.; Jiang, J.; Wei, H. X.; Han, X. F.

    2014-01-01

    Widespread application of magnetic tunnel junctions (MTJs) for information storage has so far been limited by the complicated interplay between tunnel magnetoresistance (TMR) ratio and the product of resistance and junction area (RA). An intricate connection exists between TMR ratio, RA value and the bandgap and crystal structure of the barrier, a connection that must be unravelled to optimise device performance and enable further applications to be developed. Here, we demonstrate a novel method to tailor the bandgap of an ultrathin, epitaxial Zn-doped MgO tunnel barrier with rocksalt structure. This structure is attractive due to its good Δ1 spin filtering effect, and we show that MTJs based on tunable MgZnO barriers allow effective balancing of TMR ratio and RA value. In this way spin-dependent transport properties can be controlled, a key challenge for the development of spintronic devices. PMID:25451163

  6. First-principles studies of phonon softening in rocksalt AgF under pressure

    NASA Astrophysics Data System (ADS)

    Li, Y.; Zhang, L. J.; Cui, T.; Li, Y. W.; Ma, Y. M.; He, Z.; Zou, G. T.

    2007-10-01

    Ab initio calculations within the framework of density-functional perturbation theory employing the generalized gradient approximation have been performed to study the lattice dynamics and elastic properties for rocksalt (RS) silver monofluoride (AgF) under pressure. The longitudinal and transverse acoustic phonon modes at the zone boundary X (0.0 0.0 1.0) point were predicted to be completely softened at 4.7 GPa. This softening behavior is suggested to be the physical driving force for the phase transition from the RS structure to the CsCl structure. Moreover, a pressure-induced softening of the shear modulus in C44 is also verified. However, instead of C44 instability, it is found that the phonon instability dominates the pressure-induced structural phase transition for AgF.

  7. Medical helicopters: carbon monoxide risk?

    PubMed

    Poulton, T J

    1987-02-01

    Carbon monoxide exposure of medical personnel working beneath the turning rotor of a medical helicopter appeared to cause mild clinical illness. We measured the carbon monoxide levels found in various locations beneath the rotor of a jet helicopter under two different conditions. Carbon monoxide levels ranged from 8-76 ppm depending on location of sampling and speed of operation of the engine. This level of carbon monoxide is potentially a problem, as is the inhalation of jet fuel vapor, when working beneath the rotors of an operating helicopter.

  8. Carbon monoxide poisoning.

    PubMed

    Guzman, Jorge A

    2012-10-01

    Carbon monoxide (CO) poisoning is the leading cause of death as a result of unintentional poisoning in the United States. CO toxicity is the result of a combination of tissue hypoxia-ischemia secondary to carboxyhemoglobin formation and direct CO-mediated damage at a cellular level. Presenting symptoms are mostly nonspecific and depend on the duration of exposure and levels of CO. Diagnosis is made by prompt measurement of carboxyhemoglobin levels. Treatment consists of the patient's removal from the source of exposure and the immediate administration of 100% supplemental oxygen in addition to aggressive supportive measures. The use of hyperbaric oxygen is controversial.

  9. Nature of copper active sites in the carbon monoxide oxidation on CuAl{sub 2}O{sub 4} and CuCr{sub 2}O{sub 4} spinel type catalysts

    SciTech Connect

    Severino, F.; Brito, J.L.; Laine, J.; Fierro, J.L.G.; Agudo, A.L.

    1998-07-01

    Unsupported copper-aluminum and copper-chromium oxides were prepared by mixing solutions of the nitrates and calcining at 1223 K, followed by treatment with washing solutions of either ammonium carbonate or nitric acid in order to extract uncombined copper oxide. Ammonium carbonate was only effective for removal of dispersed CuO, whereas nitric acid removed both dispersed a/nd crystalline CuO. Catalyst activity for CO oxidation increased with the extraction treatments, particularly with the nitric acid washing solution, indicating that the active sites are copper species derived from CuAl{sub 2}O{sub 4} and CuCr{sub 2}O{sub 4} spinels rather than from CuO. The CuCr{sub 2}O{sub 4} catalyst exhibited higher activity, suggesting that Cu species in tetrahedral coordination lead to higher activity. Also, pre-reduction with H{sub 2} produced higher activity than prereduction with CO, which can be attributed to a higher surface concentration of active species or their precursors after the former treatment. Activity results, together with TPR and XPS characterization point out that both Cu{sup 0} and Cu{sup +} species are involved in the mechanism of CO oxidation.

  10. Effect the conditions of the acid-thermal modification of clinoptilolite have on the catalytic properties of palladium-copper complexes anchored on it in the reaction of carbon monoxide oxidation

    NASA Astrophysics Data System (ADS)

    Rakitskaya, T. L.; Kiose, T. A.; Ennan, A. A.; Golubchik, K. O.; Oleksenko, L. P.; Gerasiova, V. G.

    2016-06-01

    The dependence of the physicochemical and structural-adsorption properties of natural and acid-thermal modified clinoptilolite, and of Pd(II)-Cu(II) catalysts based on them, on the duration of acid-thermal modification is investigated. The samples under study are described via XRD and thermal gravimetric (DTG and DTA) analysis, IR, DR UV-Vis, EPR spectroscopy, and water vapor adsorption. Values of both the specific surface area ( S sp) and pH of aqueous suspensions are determined. The resulting catalysts are tested in the reaction of low-temperature carbon monoxide oxidation with air oxygen. A conclusion is drawn about the nature of surface bimetallic Pd(II)-Cu(II) complexes. The greatest catalytic activity is shown by complexes based on clinoptilolite and modified with 3 M HNO3 for 0.5 and 1 h.

  11. Half-metallic ferromagnetism in rocksalt and zinc-blende MS (M=Li, Na and K): A first-principles study

    NASA Astrophysics Data System (ADS)

    Gao, G. Y.; Yao, K. L.; Song, M. H.; Liu, Z. L.

    2011-11-01

    First-principles full-potential linearized augmented plane-wave method is used to investigate the electronic structure and magnetic properties of hypothetical zinc-blende and rocksalt LiS, NaS and KS. We find that all the compounds except rocksalt LiS exhibit half-metallic ferromagnetism with an integer magnetic moment of 1.00 μ B per formula unit. The ferromagnetism results from the spin-polarization of p states of anion S. Total energies calculations indicate the rocksalt phase is lower in energy than the zinc-blende one. The total energy differences are about 0.38, 0.36 and 0.32 eV per formula unit for LiS, NaS and KS, respectively. Meanwhile, it is shown that rocksalt NaS and KS have the half-metallic gaps of 0.22 and 0.41 eV, respectively, and the half-metallic gaps are 0.03, 0.46 and 0.65 eV for zinc-blende LiS, NaS and KS, respectively. We also find the half-metallicity is robust against the lattice contraction up to 7% and 13% for rocksalt NaS and KS, respectively. Although rocksalt LiS is nonmagnetic and metallic at the equilibrium lattice constant, it shows half-metallic ferromagnetism when the lattice constant is larger than 5.40 Å.

  12. In situ tracking the reversible spinel-rocksalt structural transformation between Mn3O4 and MnO.

    PubMed

    San, Xingyuan; Zhang, Bo; Wang, Jing; Wu, Bo; Ma, Xiuliang

    2017-01-01

    Electron beam irradiation is well known to induce damage in materials. The structural transformation involved in the damage is usually believed to be an irreversible solid state chemical reaction. Here we use in situ transmission electron microscopy (TEM) combined electron-energy loss spectroscopy (EELS) technique in an aberration-corrected TEM to track the structural transformation in spinel Mn3O4 induced by electron beam irradiation. It is clarified that spinel Mn3O4 is transformed to rocksalt structured MnO by irradiation and the reversed recovering transition from rocksalt MnO to spinel Mn3O4 can occur by aging in the gentle electron beam circumstance. The mechanisms including the role of O desorption/adsorption and the displacement of Mn and O involved in the reversible transformation processes are discussed. The work presents an implication that electron beam can modify the structure at atomic dimension yielding diverse assemblies of surfaces, interfaces and colorful properties.

  13. [Acute carbon monoxide poisoning].

    PubMed

    Raphaël, Jean-Claude

    2008-04-30

    Carbon monoxide (CO) poisoning is still complicated by a high mortality and morbidity rate. Diagnosis can be obvious but is most of time difficult and sometimes remained unknown. It is usually based on clinical signs and must be confirmed by assessment of CO level in room air or in patient's expired breathing or blood and detection of a source. Mild neurological sequelae are very common. Normobaric oxygen is the first line treatment. Comatose and pregnant patients must undergo hyperbaric oxygen. All CO poisoning has to be declared to sanitary authority, which will in turn conduct a technical inspection to remove the source. The patient must be informed that he is at risk of new poisoning and of neurological complications. Progress in prevention and research in therapeutics are needed in order to reduce CO related morbidity.

  14. Carbon Monoxide Sensor

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The fuel cell is a system which employs an electrochemical process to convert gases- J such as hydrogen and oxygen directly into electricity. Under NASA sponsorship, GE's Aircraft Equipment Division developed fuel cells to supply electrical power for the Gemini and Biosatellite spacecraft of the sixties and is currently working on advanced fuel cell development. This long-term effort has resulted in a series of spinoff applications using the same general technology for a variety of purposes, among them the recently marketed Dosimeter. The Dosimeter is designed to help users meet safety requirements for industrial atmospheres, as specified by the Occupational Safety and Health Administration and other regulatory agencies. The compact, pocket-sized sensor measures personnel exposure to carbon monoxide and provides both a visual and an audible alarm if the concentration of the gas exceeds present levels. The Dosimeter offers substantial improvement in measuring accuracy over earlier warning indicators.

  15. High-pressure lattice dynamics in wurtzite and rocksalt indium nitride investigated by means of Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Ibáñez, J.; Oliva, R.; Manjón, F. J.; Segura, A.; Yamaguchi, T.; Nanishi, Y.; Cuscó, R.; Artús, L.

    2013-09-01

    We present an experimental and theoretical lattice-dynamical study of InN at high hydrostatic pressures. We perform Raman scattering measurements on five InN epilayers, with different residual strain and free electron concentrations. The experimental results are analyzed in terms of ab initio lattice-dynamical calculations on both wurtzite InN (w-InN) and rocksalt InN (rs-InN) as a function of pressure. Experimental and theoretical pressure coefficients of the optical modes in w-InN are compared, and the role of residual strain on the measured pressure coefficients is analyzed. In the case of the LO band, we analyze and discuss its pressure behavior considering the double-resonance mechanism responsible for the selective excitation of LO phonons with large wave vectors in w-InN. The pressure behavior of the L- coupled mode observed in a heavily doped n-type sample allows us to estimate the pressure dependence of the electron effective mass in w-InN. The results thus obtained are in good agreement with k·p theory. The wurtzite-to-rocksalt phase transition on the upstroke cycle and the rocksalt-to-wurtzite backtransition on the downstroke cycle are investigated, and the Raman spectra of both phases are interpreted in terms of DFT lattice-dynamical calculations.

  16. Thermoelectric properties of rocksalt ZnO from first-principles calculations

    DOE PAGES

    Alvarado, Andrew; Attapattu, Jeevake; Zhang, Yi; ...

    2015-10-22

    Zinc oxide (ZnO) undergoes a pressure-induced structural transition from its normal ambient-pressure wurtzite (WZ) phase to a rocksalt (RS) phase around 10 GPa. A recent experiment shows that the high-pressure RS ZnO phase can be recovered and stabilized at ambient conditions, which raises exciting prospects of expanding the range of properties of ZnO. For a fundamental understanding of the RS ZnO phase, we have performed first-principles calculations to determine its electronic, phonon, and thermodynamic properties at high (20 GPa) and ambient (0 GPa) pressure. Furthermore, we have calculated its electrical and thermal transport properties, which allow an evaluation of itsmore » thermoelectric figure of merit ZT at different temperature and doping levels. Our calculations show that the ambient-pressure RS ZnO phase can reach ZT values of 0.25 to 0.3 under both n-type and p-type doping in a large temperature range of 400 K to 800 K, which is considerably lower than the temperature range of 1400 K to 1600 K where WZ ZnO reaches similar ZT values. Lastly, these results establish RS ZnO as a promising material for thermoelectric devices designed to operate at temperatures desirable for many heat recovery applications.« less

  17. Thermoelectric properties of rocksalt ZnO from first-principles calculations

    SciTech Connect

    Alvarado, Andrew; Attapattu, Jeevake; Zhang, Yi; Chen, Changfeng

    2015-10-28

    Zinc oxide (ZnO) undergoes a pressure-induced structural transition from its normal ambient-pressure wurtzite (WZ) phase to a rocksalt (RS) phase around 10 GPa. A recent experiment shows that the high-pressure RS ZnO phase can be recovered and stabilized at ambient conditions, which raises exciting prospects of expanding the range of properties of ZnO. For a fundamental understanding of the RS ZnO phase, we have performed first-principles calculations to determine its electronic, phonon, and thermodynamic properties at high (20 GPa) and ambient (0 GPa) pressure. Furthermore, we have calculated its electrical and thermal transport properties, which allow an evaluation of its thermoelectric figure of merit ZT at different temperature and doping levels. Our calculations show that the ambient-pressure RS ZnO phase can reach ZT values of 0.25 to 0.3 under both n-type and p-type doping in a large temperature range of 400 K to 800 K, which is considerably lower than the temperature range of 1400 K to 1600 K where WZ ZnO reaches similar ZT values. These results establish RS ZnO as a promising material for thermoelectric devices designed to operate at temperatures desirable for many heat recovery applications.

  18. Structure and evolution of a rocksalt-mudrock-tectonite: The haselgebirge in the Northern Calcareous Alps

    PubMed Central

    Leitner, Christoph; Neubauer, Franz; Urai, János L.; Schoenherr, Johannes

    2011-01-01

    The Northern Calcareous Alps are part of the Eastern Alps in Austria and Germany. The Mesozoic units of this fold-and-thrust belt were detached, thrusted and stacked along the evaporitic Haselgebirge Formation. Exposed in salt mines, rocksalt and mudrock form a two component tectonite: The rock type “haselgebirge” consists of 10–70 wt % halite with silt- to gravel- or block-sized components within a halite matrix, and the “kerngebirge” with >70 wt % halite. All rock types studied are fault rocks. By use of a temperature-independent subgrain size piezometer, the paleo-differential stress of halite was calculated at ca. 2.5 MPa in Altaussee and ca. 4.5 MPa in Berchtesgaden. Including data from a grain-size piezometer, temperatures were estimated at ca. 150 ± 20 °C and 110 ± 10 °C. This implies very high strain rates, which are about 10−10–10−9 s−1. During the tectonic movement, the halite deformed, recrystallized, and crystallized as veins in mudrock fractures. We interpret high overpressure of the pore fluid to have significantly contributed to fracturing of the mudrock. PMID:26523077

  19. Thermoelectric properties of rocksalt ZnO from first-principles calculations

    SciTech Connect

    Alvarado, Andrew; Attapattu, Jeevake; Zhang, Yi; Chen, Changfeng

    2015-10-22

    Zinc oxide (ZnO) undergoes a pressure-induced structural transition from its normal ambient-pressure wurtzite (WZ) phase to a rocksalt (RS) phase around 10 GPa. A recent experiment shows that the high-pressure RS ZnO phase can be recovered and stabilized at ambient conditions, which raises exciting prospects of expanding the range of properties of ZnO. For a fundamental understanding of the RS ZnO phase, we have performed first-principles calculations to determine its electronic, phonon, and thermodynamic properties at high (20 GPa) and ambient (0 GPa) pressure. Furthermore, we have calculated its electrical and thermal transport properties, which allow an evaluation of its thermoelectric figure of merit ZT at different temperature and doping levels. Our calculations show that the ambient-pressure RS ZnO phase can reach ZT values of 0.25 to 0.3 under both n-type and p-type doping in a large temperature range of 400 K to 800 K, which is considerably lower than the temperature range of 1400 K to 1600 K where WZ ZnO reaches similar ZT values. Lastly, these results establish RS ZnO as a promising material for thermoelectric devices designed to operate at temperatures desirable for many heat recovery applications.

  20. Formation of titanium monoxide (001) single-crystalline thin film induced by ion bombardment of titanium dioxide (110)

    NASA Astrophysics Data System (ADS)

    Pabón, B. M.; Beltrán, J. I.; Sánchez-Santolino, G.; Palacio, I.; López-Sánchez, J.; Rubio-Zuazo, J.; Rojo, J. M.; Ferrer, P.; Mascaraque, A.; Muñoz, M. C.; Varela, M.; Castro, G. R.; de La Fuente, O. Rodríguez

    2015-02-01

    A plethora of technological applications justify why titanium dioxide is probably the most studied oxide, and an optimal exploitation of its properties quite frequently requires a controlled modification of the surface. Low-energy ion bombardment is one of the most extended techniques for this purpose and has been recently used in titanium oxides, among other applications, to favour resistive switching mechanisms or to form transparent conductive layers. Surfaces modified in this way are frequently described as reduced and defective, with a high density of oxygen vacancies. Here we show, at variance with this view, that high ion doses on rutile titanium dioxide (110) induce its transformation into a nanometric and single-crystalline titanium monoxide (001) thin film with rocksalt structure. The discovery of this ability may pave the way to new technical applications of ion bombardment not previously reported, which can be used to fabricate heterostructures and interfaces.

  1. Composite catalyst for carbon monoxide and hydrocarbon oxidation

    DOEpatents

    Liu, Wei; Flytzani-Stephanopoulos, Maria

    1996-01-01

    A method and composition for the complete oxidation of carbon monoxide and/or hydrocarbon compounds. The method involves reacting the carbon monoxide and/or hydrocarbons with an oxidizing agent in the presence of a metal oxide composite catalyst. The catalyst is prepared by combining fluorite-type oxygen ion conductors with active transition metals. The fluorite oxide, selected from the group consisting of cerium oxide, zirconium oxide, thorium oxide, hafnium oxide, and uranium oxide, and may be doped by alkaline earth and rare earth oxides. The transition metals, selected from the group consisting of molybdnum, copper, cobalt, maganese, nickel, and silver, are used as additives. The atomic ratio of transition metal to fluorite oxide is less than one.

  2. Composite catalyst for carbon monoxide and hydrocarbon oxidation

    DOEpatents

    Liu, W.; Flytzani-Stephanopoulos, M.

    1996-03-19

    A method and composition are disclosed for the complete oxidation of carbon monoxide and/or hydrocarbon compounds. The method involves reacting the carbon monoxide and/or hydrocarbons with an oxidizing agent in the presence of a metal oxide composite catalyst. The catalyst is prepared by combining fluorite-type oxygen ion conductors with active transition metals. The fluorite oxide, selected from the group consisting of cerium oxide, zirconium oxide, thorium oxide, hafnium oxide, and uranium oxide, and may be doped by alkaline earth and rare earth oxides. The transition metals, selected from the group consisting of molybdenum, copper, cobalt, manganese, nickel, and silver, are used as additives. The atomic ratio of transition metal to fluorite oxide is less than one.

  3. Emergent nanoscale fluctuations in high rock-salt PbTe

    NASA Astrophysics Data System (ADS)

    Billinge, Simon

    2013-03-01

    Lead Telluride is one of the most promising thermoelectric materials in the temperature range just above room temperature. It is a narrow band gap semiconductor with a high Seebeck coefficient and a low thermal conductivity. It is structurally much simpler than many other leading candidates for high performance thermoelectrics being a binary rock-salt, isostructural to NaCl. The thermoelectric figure of merit, ZT, can be markedly improved by alloying with various other elements by forming quenched nanostructures. The undoped endmember, PbTe, does not have any such quenched nanostructure, yet has a rather low intrinsic thermal conductivity. There are also a number of interesting and non-canonical behaviors that it exhibits, such as an increasing measured band-gap with increasing temperature, exactly opposite to what is normally seen due to Fermi smearing of the band edge, and an unexpected non-monotonicity of the band gap in the series PbTe - PbSe - PbS. The material is on the surface simple, but hides some interesting complexity. We have investigated in detail the PbTe endmember using x-ray and neutron diffraction and neutron inelastic scattering. To our surprise, using the atomic pair distribution function (PDF) analysis of neutron powder diffraction data we found that an interesting and non-trivial local structure that appears on warming. with the Pb atoms moving off the high-symmetry rock-salt positions towards neighboring Te ions. No evidence for the off-centering of the Pb atoms is seen at low temperature. The crossover from the locally undistorted to the locally distorted state occurs on warming between 100 K and 250 K. This unexpected emergence of local symmetry broken distortions from an undistorted ground-state we have called emphanisis, from the Greek for appearing from nothing. We have also investigated the lattice dynamics of the system to search for a dynamical signature of this behavior and extended the studies to doped systems and I will also

  4. Carbon monoxide intoxication.

    PubMed

    Bleecker, Margit L

    2015-01-01

    Carbon monoxide (CO) is a colorless, odorless, nonirritant gas that accounts for numerous cases of CO poisoning every year from a variety of sources of incomplete combustion of hydrocarbons. These include poorly functioning heating systems, indoor propane-powered forklifts, indoor burning of charcoal burning briquettes, riding in the back of pick-up trucks, ice skating rinks using propane-powered resurfacing machines, and gasoline-powered generators that are not in correct locations. Once CO is inhaled it binds with hemoglobin to form carboxyhemoglobin (COHb) with an affinity 200 times greater than oxygen that leads to decreased oxygen-carrying capacity and decreased release of oxygen to tissues leading to tissue hypoxia. Ischemia occurs with CO poisoning when there is loss of consciousness that is accompanied by hypotension and ischemia in the arterial border zones of the brain. Besides binding to many heme-containing proteins, CO disrupts oxidative metabolism leading to the formation of free radicals. Once hypotension and unconsciousness occur with CO poisoning, lipid peroxidation and apoptosis follow. Because COHb has a short half-life, examination of other biomarkers of CO neurotoxicity that reflect inflammation or neuronal damage has not demonstrated consistent results. The initial symptoms with CO exposure when COHb is 15-30% are nonspecific, namely, headache, dizziness, nausea, fatigue, and impaired manual dexterity. However individuals with ischemic heart disease may experience chest pain and decreased exercise duration at COHb levels between 1% and 9%. COHb levels between 30% and 70% lead to loss of consciousness and eventually death. Following resolution of acute symptoms there may be a lucid interval of 2-40 days before the development of delayed neurologic sequelae (DNS), with diffuse demyelination in the brain accompanied by lethargy, behavior changes, forgetfulness, memory loss, and parkinsonian features. Seventy-five percent of patients with DNS

  5. First-principles calculations of the structural, elastic, electronic, chemical bonding and optical properties of zinc-blende and rocksalt GeC

    NASA Astrophysics Data System (ADS)

    Liu, Qi-Jun; Liu, Zheng-Tang; Che, Xing-Sen; Feng, Li-Ping; Tian, Hao

    2011-12-01

    Structural parameters, elastic, electronic, bonding and optical properties of zinc-blende and rocksalt GeC have been investigated using the plane-wave ultrasoft pseudopotential technique based on the first-principles density-functional theory (DFT). The ground-state properties obtained by minimizing the total energy are in favorable agreement with the previous work. Two phases of GeC are found to be elastically stable and we have obtained the bulk, shear and Young's modulus, Poisson's coefficient and Lamé's constants for zinc-blende and rocksalt GeC. We estimated the Debye temperature of zinc-blende and rocksalt GeC from the acoustic velocity. Electronic and chemical bonding properties have been studied. Moreover, the complex dielectric function, refractive index, extinction coefficient, optical reflectivity, absorption coefficient, energy-loss spectrum and the complex conductivity function are calculated.

  6. [Carbon monoxide intoxications in Portugal].

    PubMed

    Sá, Márcia Christel; Rodrigues, Rui Paulo; Moura, Daniel

    2011-01-01

    The prevalence of carbon monoxide intoxication in the World shows that this is a common situation. In Portugal, there are no concrete data available in literature and its incidence remains unknown. Currently, the use of hyperbaric oxygen is a valid therapeutic for carbon monoxide poisoning management. However, its effectiveness and its proper handling are still controversial. The first aim of this study was to estimate the incidence of carbon monoxide intoxication in Portugal and to analyze its demographic characteristics. The second objective of this work was to evaluate the possible change in the type of treatment applied in areas near de hyperbaric chamber of Unidade Local de Saúde de Matosinhos, since its opening in June 2006. To achieve these objectives, we conducted a survey on admissions data for carbon monoxide intoxication occured between January first, 2000 and December 31, 2007. These data was collected in seven hospitals and in the Administração Central do Sistema de Saúde, I.P. Nationally, 621 hospitalizations were recorded, which represents an incidence of 5,86/100000 in 8 years. In the seven hospitals, there were 93 hospitalizations due to carbon monoxide intoxication during the same period of time. There was a peak of incidence during winter, between November and March and there was a similar distribution in men (47,3%) and women (52,7%). Since June 2006, date of opening of the hyperbaric chamber, the Unidade Local de Saúde de Matosinhos, E.P.E. recorded a sharp increase in the number of hospitalization for carbon monoxide intoxication. The number of admissions in the 19 months after the chamber opening was double the number of all cases occurred in that institution in the 65 months prior. We concluded that, in Portugal, carbon monoxide intoxication is an uncommon situation but it´s still an important cause of hospitalization. The referral of cases to the Unidade Local de Saúde de Matosinhos, E.P.E. since the opening of hyperbaric chamber

  7. (Carbon monoxide metabolism by photosynthetic bacteria)

    SciTech Connect

    Not Available

    1989-01-01

    Research continued on the metabolism of carbon monoxide by Rhodospirillum rubrum. This report discusses progress on the activity, induction, inhibition, and spectroscopic analysis of the enzyme Carbon Monoxide Dehydrogenase. (CBS)

  8. 29 CFR 1917.24 - Carbon monoxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Carbon monoxide. 1917.24 Section 1917.24 Labor Regulations...) MARINE TERMINALS Marine Terminal Operations § 1917.24 Carbon monoxide. (a) Exposure limits. The carbon... employees shall be removed from the enclosed space if the carbon monoxide concentration exceeds a ceiling...

  9. 29 CFR 1917.24 - Carbon monoxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Carbon monoxide. 1917.24 Section 1917.24 Labor Regulations...) MARINE TERMINALS Marine Terminal Operations § 1917.24 Carbon monoxide. (a) Exposure limits. The carbon... employees shall be removed from the enclosed space if the carbon monoxide concentration exceeds a ceiling...

  10. 29 CFR 1917.24 - Carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Carbon monoxide. 1917.24 Section 1917.24 Labor Regulations...) MARINE TERMINALS Marine Terminal Operations § 1917.24 Carbon monoxide. (a) Exposure limits. The carbon... employees shall be removed from the enclosed space if the carbon monoxide concentration exceeds a ceiling...

  11. 29 CFR 1917.24 - Carbon monoxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Carbon monoxide. 1917.24 Section 1917.24 Labor Regulations...) MARINE TERMINALS Marine Terminal Operations § 1917.24 Carbon monoxide. (a) Exposure limits. The carbon... employees shall be removed from the enclosed space if the carbon monoxide concentration exceeds a ceiling...

  12. 29 CFR 1917.24 - Carbon monoxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Carbon monoxide. 1917.24 Section 1917.24 Labor Regulations...) MARINE TERMINALS Marine Terminal Operations § 1917.24 Carbon monoxide. (a) Exposure limits. The carbon... employees shall be removed from the enclosed space if the carbon monoxide concentration exceeds a ceiling...

  13. Understanding the Rocksalt-to-Wurtzite phase transformation through microstructural analysis of (Al,Sc)N epitaxial thin films

    NASA Astrophysics Data System (ADS)

    Saha, Bivas; Saber, Sammy; Stach, Eric A.; Kvam, Eric P.; Sands, Timothy D.

    2016-10-01

    Rocksalt-to-wurtzite structural phase transitions in semiconducting materials (such as III-V nitrides, ZnO, CdSe, and others) have been studied for several decades. Almost all experimental works related to this phase transition involve diamond anvil cells to apply hydrostatic pressure, and as a result, direct observation of the microstructural transformation during the phase transition has not been possible. In this article, we have addressed and uncovered the intimate microstructural details and epitaxial relationships between phases by capturing what is essentially a thin-film snapshot of the transformation after growth of AlxSc1-xN films with a composition chosen to be close to the equilibrium phase boundary between wurtzite and rocksalt. The results support the hypothesis that the transformation is triggered by defects at rs- {0 1 ¯ 1 } growth fronts that offer a nearly invariant plane with respect to the parallel w- {2 1 ¯ 1 ¯0 } planes. The intermediate crystal structures and their epitaxial relationships are consistent with theoretical models that predict a transformation pathway involving homogeneous orthorhombic shear strain.

  14. Carbon monoxide and lethal arrhythmias

    SciTech Connect

    Farber, J.P.; Schwartz, P.J.; Vanoli, E.; Stramba-Badiale, M.; De Ferrari, G.M. )

    1990-12-01

    The effect of acute exposure to carbon monoxide on ventricular arrhythmias was studied in a previously described chronically maintained animal model of sudden cardiac death. In 60 percent of dogs with a healed anterior myocardial infarction, the combination of mild exercise and acute myocardial ischemia induces ventricular fibrillation. The events in this model are highly reproducible, thus allowing study by internal control analysis. Dogs that develop ventricular fibrillation during the test of exercise and acute myocardial ischemia are considered at high risk for sudden death and are defined as 'susceptible'; dogs that survive the test without a fatal arrhythmia are considered at low risk for sudden death and are defined as 'resistant.' In the current study, the effects of carboxyhemoglobin levels ranging from 5 to 15 percent were tested in resistant and susceptible dogs. A trend toward higher heart rates was observed at all levels of carboxyhemoglobin, although significant differences were observed only with 15 percent carboxyhemoglobin. This trend was observed at rest and during exercise in both resistant and susceptible dogs. In resistant animals, in which acute myocardial ischemia is typically associated with bradycardia even under the control condition, this reflex response occurred earlier and was augmented after exposure to carbon monoxide. This effect may depend on the increased hypoxic challenge caused by carbon monoxide, and thus on an augmentation of the neural reflex activation or a sensitization of the sinus node to acetylcholine induced by hypoxia. In both resistant and susceptible dogs, carbon monoxide exposure induced a worsening of ventricular arrhythmias in a minority of cases. This worsening was not reproducible in subsequent trials. These data indicate that acute exposure to carbon monoxide is seldom arrhythmogenic in dogs that have survived myocardial infarction. (Abstract Truncated)

  15. Carbon Monoxide from Biomass Burning

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This pair of images shows levels of carbon monoxide at the atmospheric pressure level of 700 millibars (roughly 12,000 feet in altitude) over the continent of South America, as observed by the Measurements Of Pollution In The Troposphere (MOPITT) sensor flying aboard NASA's Terra spacecraft. Data for producing the image on the left were acquired on March 3, 2000, and for the image on the right on September 7, 2000. Blue pixels show low values, yellows show intermediate values, and the red to pink and then white pixels are progressively higher values. In the lefthand image (March 3), notice the fairly low levels of carbon monoxide over the entire continent. The slightly higher equatorial values are the result of burning emissions in sub-Saharan Africa that are convected at the Intertropical Convergence Zone (ITCZ) and spread by the trade winds. Also, notice the effect of the elevated surface topography across the Andes Mountains running north to south along the western coastline. (In this region, white pixels show no data.) In the righthand image (September 7), a large carbon monoxide plume is seen over Brazil, produced primarily by biomass burning across Amazonia and lofted into the atmosphere by strong cloud convection. The generally higher carbon monoxide levels as compared to March are both the result of South American fire emissions and the transport of carbon monoxide across the Atlantic Ocean from widespread biomass burning over Southern Africa. These images were produced using MOPITT data, which are currently being validated. These data were assimilated into an atmospheric chemical transport model using wind vectors provided by the National Center for Environmental Prediction (NCEP). Although there is good confidence in the relative seasonal values and geographic variation measured by MOPITT, that team anticipates their level of confidence will improve further with ongoing intensive validation campaigns and comparisons with in situ and ground

  16. Carbon Monoxide from Biomass Burning

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This pair of images shows levels of carbon monoxide at the atmospheric pressure level of 700 millibars (roughly 12,000 feet in altitude) over the continent of South America, as observed by the Measurements Of Pollution In The Troposphere (MOPITT) sensor flying aboard NASA's Terra spacecraft. Data for producing the image on the left were acquired on March 3, 2000, and for the image on the right on September 7, 2000. Blue pixels show low values, yellows show intermediate values, and the red to pink and then white pixels are progressively higher values. In the lefthand image (March 3), notice the fairly low levels of carbon monoxide over the entire continent. The slightly higher equatorial values are the result of burning emissions in sub-Saharan Africa that are convected at the Intertropical Convergence Zone (ITCZ) and spread by the trade winds. Also, notice the effect of the elevated surface topography across the Andes Mountains running north to south along the western coastline. (In this region, white pixels show no data.) In the righthand image (September 7), a large carbon monoxide plume is seen over Brazil, produced primarily by biomass burning across Amazonia and lofted into the atmosphere by strong cloud convection. The generally higher carbon monoxide levels as compared to March are both the result of South American fire emissions and the transport of carbon monoxide across the Atlantic Ocean from widespread biomass burning over Southern Africa. These images were produced using MOPITT data, which are currently being validated. These data were assimilated into an atmospheric chemical transport model using wind vectors provided by the National Center for Environmental Prediction (NCEP). Although there is good confidence in the relative seasonal values and geographic variation measured by MOPITT, that team anticipates their level of confidence will improve further with ongoing intensive validation campaigns and comparisons with in situ and ground

  17. Remarkable transition from rocksalt/perovskite layered structure to fluorite/rocksalt layered structure in rapidly cooled Ln₂CuO₄.

    PubMed

    Patabendige, Chami N K; Azad, Abul K; Connor, Paul A; Rolle, Aurélie; Irvine, John T S

    2013-01-01

    Lanthanide cuprates of formula Ln₂CuO₄ exist in two principal forms, T and T' which are renowned for their exhibition at low temperatures of hole and electronic types of superconductivity, respectively. These structures differ primarily in the arrangement of oxygen between the perovskite layers and also in nature of the copper oxygen planes. The Cu-O distance in the T structure (~1.90 Å) is much shorter than the T' (1.97Å), reflecting a transition between partial Cu⁺and partial Cu³⁺ character. In seeking to find compositions that bridge these two structure/electron carrier types, we observed the transition from a T structure to a T' type structure, resulting in the metastable form T″ with slightly larger volume but similar character to T'. This transition from T to T″ is associated with 5% increase in a and a 5% decrease in c parameters of the tetragonal unit cells, which results in disintegration of ceramic bodies.

  18. Four-electron deoxygenative reductive coupling of carbon monoxide at a single metal site

    NASA Astrophysics Data System (ADS)

    Buss, Joshua A.; Agapie, Theodor

    2016-01-01

    Carbon dioxide is the ultimate source of the fossil fuels that are both central to modern life and problematic: their use increases atmospheric levels of greenhouse gases, and their availability is geopolitically constrained. Using carbon dioxide as a feedstock to produce synthetic fuels might, in principle, alleviate these concerns. Although many homogeneous and heterogeneous catalysts convert carbon dioxide to carbon monoxide, further deoxygenative coupling of carbon monoxide to generate useful multicarbon products is challenging. Molybdenum and vanadium nitrogenases are capable of converting carbon monoxide into hydrocarbons under mild conditions, using discrete electron and proton sources. Electrocatalytic reduction of carbon monoxide on copper catalysts also uses a combination of electrons and protons, while the industrial Fischer-Tropsch process uses dihydrogen as a combined source of electrons and electrophiles for carbon monoxide coupling at high temperatures and pressures. However, these enzymatic and heterogeneous systems are difficult to probe mechanistically. Molecular catalysts have been studied extensively to investigate the elementary steps by which carbon monoxide is deoxygenated and coupled, but a single metal site that can efficiently induce the required scission of carbon-oxygen bonds and generate carbon-carbon bonds has not yet been documented. Here we describe a molybdenum compound, supported by a terphenyl-diphosphine ligand, that activates and cleaves the strong carbon-oxygen bond of carbon monoxide, enacts carbon-carbon coupling, and spontaneously dissociates the resulting fragment. This complex four-electron transformation is enabled by the terphenyl-diphosphine ligand, which acts as an electron reservoir and exhibits the coordinative flexibility needed to stabilize the different intermediates involved in the overall reaction sequence. We anticipate that these design elements might help in the development of efficient catalysts for

  19. A Mixed-Basis Band Structure Interpolation Scheme Applied to the Rocksalt Structure Compounds TiC, TiN and TiO.

    DTIC Science & Technology

    1986-10-15

    I . BaMiltonian of the rocksalt structure is identical to that of the fcc ... structure . 4 The parameters of the NBBSIS for a particular system were determined by applying a nonlinear least squares method1 3 to fit the energy

  20. Optical and electron transport properties of rock-salt Sc1-xAlxN

    NASA Astrophysics Data System (ADS)

    Deng, Ruopeng; Zheng, P. Y.; Gall, D.

    2015-07-01

    Epitaxial single-crystal Sc1-xAlxN ternary alloy layers deposited by magnetron co-sputtering on MgO(001) substrates at 950 °C exhibit a solid solution rock-salt phase for x = 0-0.2 without decomposition. Optical absorption indicates a linear increase in the optical gap from 2.51 eV for ScN to 3.05 eV for Sc0.8Al0.2N and, after correction due to the Moss-Burstein shift, a direct X point interband transition energy Eg(X) = 2.15 + 2.75 x (eV). Correspondingly, the direct transition at the zone center increases with Al concentration according to Eg(Γ) = 3.80 + 1.45 x (eV), as determined from a feature in the reflection spectra. All layers are degenerate n-type semiconductors with a room temperature mobility that decreases from 22 to 6.7 to 0.83 cm2/V s as x increases from 0 to 0.11 to 0.20. The corresponding carrier densities are 9.2 × 1020, 7.9 × 1020, and 0.95 × 1020 cm-3 as determined from Hall measurements and consistent with optical free carrier absorption below photon energies of 1 eV. Temperature dependent transport measurements indicate metallic conduction for ScN, but weak localization that leads to a resistivity minimum at 85 and 210 K for x = 0.051 and 0.15, respectively, and a negative temperature coefficient over the entire measured 4-300 K range for Sc0.8Al0.2N. The decreasing mobility is attributed to alloy scattering at randomly distributed Al atoms on cation sites, which also cause the weak localization. The carrier density is primarily due to unintentional F doping from the Sc target and decreases strongly for x > 0.15, which is attributed to trapping in defect states due to the deterioration of the crystalline quality, as evidenced by the x-ray diffraction peak width that exhibits a minimum of 0.14° for x = 0.11 but increases to 0.49° for x = 0.20. This is consistent with asymmetric x-ray diffraction analyses, indicating a relaxed lattice constant that decreases from 4.511 ± 0.005 to 4.411 ± 0.004 Å for x = 0-0.2, and a biaxial in

  1. Anthropogenic emissions of carbon monoxide.

    PubMed

    Horner, J M

    2000-01-01

    Carbon monoxide (CO) is a colorless, nonirritating, odorless and tasteless gas. Carbon monoxide combines with hemoglobin far more readily than does oxygen, leading to tissue hypoxia. Thousands of people die annually from CO poisoning, and those recovering from acute exposure commonly suffer brain damage. Chronic poisoning is of particular concern to sufferers of coronary heart disease, pregnant women, and people with certain hematological disorders. Indoor emission sources, notably fuel-burning heating appliances, cause most unintentional deaths and cases of illness and should be the main focus of concern. Motor vehicle emissions pose a chronic health risk for occupationally exposed groups. Smoking is a major source of personal exposure. Recent exposure to CO is commonly evaluated by measuring blood carboxyhemoglobin levels, which are related to the concentration of atmospheric CO. Monitoring methods are reviewed here, and monitoring is considered in relation to air quality standards and guidelines. Finally, control measures for motor vehicles and indoor heating appliances are suggested.

  2. Half metallicity and magnetic stability of sp-electron superlattices in rock-salt structure: A first-principles study

    NASA Astrophysics Data System (ADS)

    Zhou, Baozeng; Dong, Shengjie; Chen, Shanxing; Zhang, Zidan; Zhao, Hui; Wu, Ping

    2014-08-01

    Density functional calculations were performed to study the structural, electronic, and magnetic properties of sp-electron half-metallic superlattices (KS)1/(CaS)1, (RbS)1/(SrS)1, and (CsS)1/(BaS)1 (001) in rock-salt structure. All the superlattices are found to be spin polarized, and the calculated band structure suggests a 100% polarization of the conduction carriers. The p-p hybridization is shown to be essential for the formations of localized orbitals and spin-splitting. The half-metallic electronic structure will be destroyed upon an excessive lattice compression, accompanying with a metallic transition. Moreover, the analysis of the orbital-decomposed partial density of states and spin density reveal that S atoms in different layers of the superlattice show distinct polarization directions. Discussion of volume-conserving deformations further demonstrates the stability of half metallicity in sp-electron superlattices.

  3. Zinc-blende to rocksalt transition in SiC in a laser-heated diamond-anvil cell

    NASA Astrophysics Data System (ADS)

    Daviau, Kierstin; Lee, Kanani K. M.

    2017-04-01

    We explore the stability of the ambient pressure zinc-blende polymorph (B3) structure of silicon carbide (SiC) at high pressures and temperatures where it transforms to the rocksalt (B1) structure. We find that the transition occurs ˜40 GPa lower than previously measured when heated to moderately high temperatures. A lower transition pressure is consistent with the transition pressures predicted in numerous ab initio computations. We find a large volume decrease across the transition of ˜17%, with the volume drop increasing at higher formation pressures, suggesting this transition is volume driven yielding a nearly pressure-independent Clapeyron slope. Such a dramatic density increase occurring at pressure is important to consider in applications where SiC is exposed to extreme conditions, such as in industrial applications or planetary interiors.

  4. Zinc-blende to rock-salt structural phase transition of BP and BAs under high pressure

    NASA Astrophysics Data System (ADS)

    Sarwan, Madhu; Bhardwaj, Purvee; Singh, Sadhna

    2013-11-01

    In the present paper, we have investigated the pressure induced phase transition and thermophysical properties of BP and BAs by means of modified interaction potential model (MIPM). The MIPM consists of Coulomb interaction, three-body interaction (TBI) modified by taking covalency effect, van-der Waal interaction (vdW), short range overlap repulsive interaction and zero point energy effect. These compounds crystallize in zinc-blende (ZB) structure at ambient condition and transform to rock-salt (RS) structure at pressures 111 and 93 GPa and their equation of state show volume collapse of 14% and 4% respectively for BP and BAs. The second order elastic constants have also been computed at zero and high pressures. Our results are in good agreement with the experimental results. The mechanical and thermophysical properties in ZB structure are also predicted.

  5. Energy-polarization behaviors of AA'BB'O6 perovskites with double rock-salt order

    NASA Astrophysics Data System (ADS)

    Roy, Anindya; Vanderbilt, David

    2010-03-01

    Using first-principles methods, we study the energy-polarization relation of double perovskites AA'BB'O6 where atoms in both A and B sites are arranged in rock-salt order. The high-symmetry structure in this case is the tetrahedral F43m space group. If a ferroelectric instability occurs, the energy-vs.-polarization landscape E(P) will tend to have minima for P along tetrahedral directions leading to a rhombohedral space group R3m, with two different values of spontaneous polarization and associated energy along opposite body-diagonal directions; or along Cartesian directions, leading to orthorhombic space group Imm2. We search for polar soft modes at the γ point of the high-symmetry F43m structure and analyze its eigenvectors to identify ferroelectric instabilities, which we find in CaBaTiZrO6, KCaZrNbO6 and PbSnTiZrO6. The results of the first-principle calculations are modeled with a Landau-Devonshire expansion that is truncated at either 4th or 5th order in P, and its predictions are found to agree favorably with our calculation. The 5th-order calculation improves the agreement further except in PSTZ. Recently, synthesis of SrCaTiMnO6 in rock-salt order has been reported.footnotetextJ.L Blok, G. Rijnders and D.H.A. Blank, private communication. Unfortunately, preliminary results do not seem to indicate any polarized structure.

  6. Carbon monoxide kinetics following simulated cigarette smoking

    SciTech Connect

    Karnik, A.S.; Coin, E.J.

    1980-05-01

    Carbon monoxide kinetics were measured in the blood (% carboxyhemoglobin) and alveolar phase (ppM carbon monoxide) after simulated cigarette smoking. Cigarette smoking was siumlated using the same amount of carbon monoxide that 2R1F cigarettes manufactured by the Tobacco Research Institute would contain. Ten boluses of air containing carbon monoxide equivalent to smoking one cigarette were inhaled by six healthy nonsmoker volunteers. Carbon monoxide in the air phase was measured by an Ecolyzer and carboxyhemoglobin was measured by a CO-Oximeter. The mean rise in alveolar carbon monoxide immediately and 20 min after inhaling the last bolus was 3.3 and 3.1 ppM, respectively (p<.005). The mean rise in carboxyhemoglobin immediately and 20 min after inhalation of the last bolus was 0.8 and 0.5% respectively (P<.005). The changes in carboxyhemoglobin were found to be similar to changes that occur when one cigarette is actually smoked.

  7. The Albuquerque carbon monoxide source apportionment study

    SciTech Connect

    Einfeld, W.

    1988-07-01

    At the request of the New Mexico Environmental Improvement Division, a study was carried out to examine, in detail, the relative contribution of various combustion sources to ambient carbon monoxide in Albuquerque during the winter season evening hours. The two-month field study (January--February 1985) included aerosol and gas monitoring at two sites in the Albuquerque area. Source contributions to ambient carbon monoxide were determined by regression techniques using tracer elements and by carbon isotope measurements on collected carbon monoxide. Results from isotopic carbon analysis of carbon monoxide show that, on average, mobile sources contributed 68 percent and wood burning sources 32 percent to ambient carbon monoxide levels during winter season evening hours. Good agreement was found between results from carbon isotope and linear regression techniques used to estimate average source strengths. The study results point to the significance of both mobile and residential wood burning sources as contributors to ambient carbon monoxide levels. 1 ref., 10 figs., 19 tabs.

  8. Carbon monoxide hazards in rural Alaskan homes.

    PubMed

    Howell, J; Keiffer, M P; Berger, L R

    1997-01-01

    Alaska has the highest age-adjusted death rate from unintentional carbon monoxide poisoning in the nation. We conducted a study in five villages to determine carbon monoxide levels and sources. Nearly 10% (10/105) of the homes had elevated levels. Improperly vented propane Paloma water heaters were most commonly responsible and produced the highest levels of carbon monoxide. Other sources were leaking pipes from wood stoves and stoves that had been left on for several hours. We recommend that Paloma water heaters not be used where freezing temperatures create a risk for carbon monoxide poisoning, fires, and explosion. Safety education campaigns should note the risks of Paloma water heaters and defective stove pipes, and the need for increased kitchen ventilation during prolonged cooking. Medical workers need to be informed of the prevalence of carbon monoxide exposures. Homeowners can install carbon monoxide detectors, although expense and false alarms remain barriers to their use.

  9. 21 CFR 862.3220 - Carbon monoxide test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon monoxide test system. 862.3220 Section 862....3220 Carbon monoxide test system. (a) Identification. A carbon monoxide test system is a device intended to measure carbon monoxide or carboxyhemoglobin (carbon monoxide bound to the hemoglobin in...

  10. 21 CFR 862.3220 - Carbon monoxide test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carbon monoxide test system. 862.3220 Section 862....3220 Carbon monoxide test system. (a) Identification. A carbon monoxide test system is a device intended to measure carbon monoxide or carboxyhemoglobin (carbon monoxide bound to the hemoglobin in...

  11. 21 CFR 862.3220 - Carbon monoxide test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbon monoxide test system. 862.3220 Section 862....3220 Carbon monoxide test system. (a) Identification. A carbon monoxide test system is a device intended to measure carbon monoxide or carboxyhemoglobin (carbon monoxide bound to the hemoglobin in...

  12. 21 CFR 862.3220 - Carbon monoxide test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carbon monoxide test system. 862.3220 Section 862....3220 Carbon monoxide test system. (a) Identification. A carbon monoxide test system is a device intended to measure carbon monoxide or carboxyhemoglobin (carbon monoxide bound to the hemoglobin in...

  13. 21 CFR 862.3220 - Carbon monoxide test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carbon monoxide test system. 862.3220 Section 862....3220 Carbon monoxide test system. (a) Identification. A carbon monoxide test system is a device intended to measure carbon monoxide or carboxyhemoglobin (carbon monoxide bound to the hemoglobin in...

  14. The dependence on pressure of the plastic flow of rocksalt in the temperature range 25-250° C: implications for the rate controlling mechanism

    NASA Astrophysics Data System (ADS)

    Muhammad, Nawaz; Spiers, Chris; De Bresser, Hans; Peach, Colin

    2014-05-01

    Despite the large body of data that already exists, the question what microphysical mechanisms govern plastic flow of natural rocksalt at in situ conditions has not yet been answered to full satisfaction. In particular, the exact mechanism controlling dislocation motion at relatively low temperature is still insufficiently understood. As a result, uncertainties exist regarding the appropriate mechanism-based flow-law for low temperature, hampering reliable extrapolation of lab creep data to in situ strain rates. Such extrapolation is required for the modelling of the long term behaviour of salt for geomechanical purposes (e.g. subsidence prognosis). Several dislocation models have been proposed to control plastic flow of rocksalt, such as dislocation climb, cross-slip and (impurity-controlled) glide, but none of these have been rigorously verified. One way to test which model is appropriate is by investigating the pressure dependence of flow of rocksalt. Dislocation glide is expected to be hardly affected by pressure, cross slip (controlled by constriction of partial dislocations) will become easier with increasing pressure, and dislocation climb will become more difficult. We performed conventional axi-symmetric compression tests on synthetic polycrystalline salt samples with an average grain size of 300 μm. The samples were dry, in order to eliminate the possible influence of pressure solution creep. The experiments were carried out at temperatures in the range 25-250° C, i.e. 0.28-0.48Tm, and at pressure ranging 50-600 MPa, which is a range not previously covered for polycrystalline rocksalt. Argon gas was used as the pressure medium. With confining pressure increasing from 50 to 600 MPa, the rocksalt remained of the same strength at RT, but became about 60% stronger at 125oC and about 80% stronger at 250oC at strain rate 10-6 s-1 (at 15% strain). Using a conventional (Dorn-type) power law to describe the mechanical behaviour, stress exponents (n) were found

  15. Environmental carbon monoxide related to pregnancy hypertension.

    PubMed

    Vigeh, Mohsen; Yunesian, Masoud; Shariat, Mamak; Niroomanesh, Shireen; Ramezanzadeh, Fateme

    2011-11-30

    Carbon monoxide pollution frequently occurs due to auto exhaust, industrial emissions, and/or cigarette smoke. Exogenous and endogenous carbon monoxide affects blood pressure; however, the relation of carbon monoxide exposure to pregnancy hypertension has not been systematically examined. For the present study the authors recruited a total of 2,707 apparently healthy, non-obese, non-smoking mothers, aged between 15 and 40 years, who had singleton births, and who lived within two miles of the selected air monitoring stations in Tehran, Iran, to study the relation of ambient carbon monoxide to pregnancy hypertension (>140 mmHg systolic and/or >90 mmHg diastolic after the 20th week of gestation). A relatively small but statistically significant elevation in mean postpartum diastolic blood pressure (mean ± SD, 69.5 ± 9.8 mmHg) was observed in the mothers' who were exposed to relatively high ambient carbon monoxide (mean = 14.1 ppm) compared to mothers exposed to lower carbon monoxide (mean = 1.8 ppm) concentrations (mean ± SD, 68.0 ± 8.3 mmHg, p < 0.01). The authors found twice the rate of pregnancy hypertension in the relatively higher carbon monoxide exposed mothers than the mothers with lower exposure (adjusted odds ratio = 2.02, 95% CI 1.35-3.03). Findings of the present study suggest that high level ambient carbon monoxide exposure is associated with pregnancy hypertension.

  16. Method of removing carbon monoxide from gases

    DOEpatents

    Gerstein, Bernard C.; Macaulay, David B.

    1976-06-01

    A process and catalyst are disclosed for purifying an atmosphere containing carbon monoxide by passing the atmosphere through a bed of a catalyst of TbO.sub.x, where x = 1.8 to 1.5, which oxidizes the carbon monoxide to carbon dioxide.

  17. Mars - Microwave detection of carbon monoxide

    NASA Technical Reports Server (NTRS)

    Kakar, R. K.; Walters, J. W.; Wilson, W. J.

    1977-01-01

    The 115-gigahertz microwave line of carbon monoxide has been detected in the spectrum of Mars. The measurement is sensitive to carbon monoxide between the surface and an altitude of approximately 50 kilometers in the Martian atmosphere. This extends the altitude region to well above that previously sensed.

  18. Lattice dynamics of wurtzite and rocksalt AlN under high pressure: Effect of compression on the crystal anisotropy of wurtzite-type semiconductors

    NASA Astrophysics Data System (ADS)

    Manjón, Francisco Javier; Errandonea, Daniel; Romero, Aldo Humberto; Garro, Núria; Serrano, Jorge; Kuball, Martin

    2008-05-01

    Raman spectra of aluminum nitride (AlN) under pressure have been measured up to 25GPa , i.e., beyond the onset of the wurtzite-to-rocksalt phase transition around 20GPa . The experimental pressure coefficients for all the Raman-active modes of the wurtzite phase are reported and compared to those obtained from ab initio lattice dynamical calculations, as well as to previous experimental and theoretical results. The pressure coefficients of all the Raman-active modes in wurtzite-type semiconductors (AlN, GaN, InN, ZnO, and BeO), as well as the relatively low bulk modulus and phase transition pressure in wurtzite AlN, are discussed in the light of the pressure dependence of the structural crystal anisotropy in wurtzite semiconductors. On pressure release, AlN partially returns to the wurtzite phase below 1.3GPa but the presence of a rocksalt phase in AlN was observed at pressures as low as 1.3GPa , as evidenced by comparing the experimental Raman spectra to calculated one- and two-phonon densities of states of the rocksalt phase.

  19. Carbon monoxide: a role in carotid body chemoreception.

    PubMed

    Prabhakar, N R; Dinerman, J L; Agani, F H; Snyder, S H

    1995-03-14

    Carbon monoxide (CO), produced endogenously by heme oxygenase, has been implicated as a neuronal messenger. Carotid bodies are sensory organs that regulate ventilation by responding to alterations of blood oxygen, CO2, and pH. Changes in blood gases are sensed by glomus cells in the carotid body that synapse on afferent terminals of the carotid sinus nerve that projects to respiratory-related neurons in the brainstem. Using immunocytochemistry, we demonstrate that heme oxygenase 2 is localized to glomus cells in the cat and rat carotid bodies. Physiological studies show that zinc protoporphyrin IX, a potent heme oxygenase inhibitor, markedly increases carotid body sensory activity, while copper protoporphyrin IX, which does not inhibit the enzyme, is inactive. Exogenous CO reverses the stimulatory effects of zinc protoporphyrin IX. These results suggest that glomus cells are capable of synthesizing CO and endogenous CO appears to be a physiologic regulator of carotid body sensory activity.

  20. Copper hypersensitivity.

    PubMed

    Fage, Simon W; Faurschou, Annesofie; Thyssen, Jacob P

    2014-10-01

    The world production of copper is steadily increasing. Although humans are widely exposed to copper-containing items on the skin and mucosa, allergic reactions to copper are only infrequently reported. To review the chemistry, biology and accessible data to clarify the implications of copper hypersensitivity, a database search of PubMed was performed with the following terms: copper, dermatitis, allergic contact dermatitis, contact hypersensitivity, contact sensitization, contact allergy, patch test, dental, IUD, epidemiology, clinical, and experimental. Human exposure to copper is relatively common. As a metal, it possesses many of the same qualities as nickel, which is a known strong sensitizer. Cumulative data on subjects with presumed related symptoms and/or suspected exposure showed that a weighted average of 3.8% had a positive patch test reaction to copper. We conclude that copper is a very weak sensitizer as compared with other metal compounds. However, in a few and selected cases, copper can result in clinically relevant allergic reactions.

  1. Electronic Transitions of Yttrium Monoxide

    NASA Astrophysics Data System (ADS)

    Ng, Y. W.; Wang, Na; Clark, Andrew B.; Cheung, A. S.-C.

    2013-06-01

    The electronic transition spectrum of yttrium monoxide (YO) in the spectral region between 284nm and 307nm has been recorded using laser ablation/reaction free-jet expansion and laser induced fluorescence (LIF) spectroscopy. The YO molecule was produced by reacting laser-ablated yttrium atoms with O_{2} seeded in argon. Twenty transition bands were observed in that region and a few bands were selected for further study using optical-optical double resonance (OODR) spectroscopy. The excited C^{2} Π state has been reached via the intermediate B^{2} Σ^{+} state from the ground X^{2} Σ^{+} state. The excited sub-states observed so far have Ω = 0.5 and 1.5. A least squares fit of the measured rotational lines yielded molecular constants for the newly observed excited states.

  2. The Carbon Monoxide Tape Recorder

    NASA Technical Reports Server (NTRS)

    Schoeberl, M. R.; Duncan, B. N.; Douglass, A. R.; Waters, J.; Livesey, N.; Read, W.; Filipiak, M.

    2006-01-01

    Using Aura MLS data we have identified the stratospheric tape recorder in carbon monoxide (CO). Unlike the water vapor tape recorder, which is controlled by upper troposphere processes, the CO tape recorder is linked to seasonal biomass burning. Since CO has a lifetime of only a few months, the CO tape recorder barely extends above 20 km. The tape head for CO appears to be close to 360K near the same location as the water vapor tape head [Read et al, 20041. Both tape heads are below the equatorial cold point tropopause but above the base of the tropical tropopause layer. The tape recorder signal becomes more distinct from 360K to 380K suggesting that convective detrainment of plays a decreasingly important role with altitude. The Global Modeling Initiative chemical transport model forced by the climatology of biomass burning reproduces the CO tape recorder.

  3. Size-controlled synthesis of bifunctional magnetic and ultraviolet optical rock-salt MnS nanocube superlattices.

    PubMed

    Yang, Xinyi; Wang, Yingnan; Sui, Yongming; Huang, Xiaoli; Cui, Tian; Wang, Chunzhong; Liu, Bingbing; Zou, Guangtian; Zou, Bo

    2012-12-21

    Wide-band-gap rock-salt (RS) MnS nanocubes were synthesized by the one-pot solvent thermal approach. The edge length of the nanocubes can be easily controlled by prolonging the reaction time (or aging time). We systematically explored the formation of RS-MnS nanocubes and found that the present synthetic method is virtually a combination of oriented aggregation and intraparticle ripening processes. Furthermore, these RS-MnS nanocubes could spontaneously assemble into ordered superlattices via the natural cooling process. The optical and magnetic properties were investigated using measured by UV-vis absorption, photoluminescence spectra, and a magnetometer. The obtained RS-MnS nanocubes exhibit good ultraviolet optical properties depending on the size of the samples. The magnetic measurements suggest that RS-MnS nanocubes consist of an antiferromagnetic core and a ferromagnetic shell below the blocking temperatures. Furthermore, the hysteresis measurements indicate these RS-MnS nanocubes have large coercive fields (e.g., 1265 Oe for 40 nm nanocubes), which is attributed to the size and self-assembly of the samples.

  4. Attainable high capacity in Li-excess Li-Ni-Ru-O rock-salt cathode for lithium ion battery

    NASA Astrophysics Data System (ADS)

    Wang, Xingbo; Huang, Weifeng; Tao, Shi; Xie, Hui; Wu, Chuanqiang; Yu, Zhen; Su, Xiaozhi; Qi, Jiaxin; Rehman, Zia ur; Song, Li; Zhang, Guobin; Chu, Wangsheng; Wei, Shiqiang

    2017-08-01

    Peroxide structure O2n- has proven to appear after electrochemical process in many lithium-excess precious metal oxides, representing extra reversible capacity. We hereby report construction of a Li-excess rock-salt oxide Li1+xNi1/2-3x/2Ru1/2+x/2O2 electrode, with cost effective and eco-friendly 3d transition metal Ni partially substituting precious 4d transition metal Ru. It can be seen that O2n- is formed in pristine Li1.23Ni0.155Ru0.615O2, and stably exists in subsequent cycles, enabling discharge capacities to 295.3 and 198 mAh g-1 at the 1st/50th cycle, respectively. Combing ex-situ X-ray absorption near edge spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, high resolution transmission electron microscopy and electrochemical characterization, we demonstrate that the excellent electrochemical performance comes from both percolation network with disordered structure and cation/anion redox couples occurring in charge-discharge process. Li-excess and substitution of common element have been demonstrated to be a breakthrough for designing novel high performance commercial cathodes in rechargeable lithium ion battery field.

  5. Carbon monoxide and the burning earth

    SciTech Connect

    Newell, R.E.; Reichle, H.G. Jr.; Seiler, W.

    1989-10-01

    Carbon monoxide is one of many gases whose presence in the atmosphere is blamed largely on industrial activity in the Northern Hemisphere. Data collected by the authors show that the gas is also abundant in the Southern Hemisphere, where it comes mainly from the burning of tropical rain forests and savannas. The high levels of carbon monoxide confirm other evidence that the rain forests are being diminished rapidly, which may affect the climates of these regions as well as globally. Increases in carbon monoxide could also encourage the accumulation of pollutant gases such as ozone and methane. The first is highly toxic to plants and the second would add to the greenhouse effect.

  6. Tests confirm gas heat as monoxide source

    SciTech Connect

    Besch, E.

    1984-03-01

    Six tests were conducted to demonstrate the potential for natural gas or oil-fired forced warm air heating equipment to produce carbon monoxide emission when the combustion process is impeded by typical causes found in households. In the case of the gas-fired units, impeded combustion produced a smell of aldehyde and various levels of carbon monoxide emission; all within the level dangerous to health. It was concluded that oil-fired warm air systems do not pose a carbon monoxide danger but that natural gas warm air systems do pose a real danger and should be so identified.

  7. 40 CFR 52.1682 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) Approval—The November 13, 1992 revision to the carbon monoxide state implementation... attainment of the National Ambient Air Quality Standard for carbon monoxide through the year 2003....

  8. 40 CFR 52.2353 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. Determination. EPA has determined that the Provo carbon monoxide “moderate” nonattainment area attained the carbon monoxide national ambient air quality standard by December 31, 1995....

  9. 40 CFR 91.317 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Carbon monoxide analyzer calibration... Provisions § 91.317 Carbon monoxide analyzer calibration. (a) Calibrate the NDIR carbon monoxide analyzer... service and annually thereafter, check the NDIR carbon monoxide analyzer for response to water vapor...

  10. 21 CFR 177.1312 - Ethylene-carbon monoxide copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ethylene-carbon monoxide copolymers. 177.1312... Use Food Contact Surfaces § 177.1312 Ethylene-carbon monoxide copolymers. The ethylene-carbon monoxide... of this section, ethylene-carbon monoxide copolymers (CAS Reg. No. 25052-62-4) consist of the...

  11. 40 CFR 52.1682 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) Approval—The November 13, 1992 revision to the carbon monoxide state implementation... attainment of the National Ambient Air Quality Standard for carbon monoxide through the year 2003....

  12. 40 CFR 52.1682 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) Approval—The November 13, 1992 revision to the carbon monoxide state implementation... attainment of the National Ambient Air Quality Standard for carbon monoxide through the year 2003....

  13. 40 CFR 52.2353 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. Determination. EPA has determined that the Provo carbon monoxide “moderate” nonattainment area attained the carbon monoxide national ambient air quality standard by December 31, 1995....

  14. 40 CFR 52.1682 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) Approval—The November 13, 1992 revision to the carbon monoxide state implementation... attainment of the National Ambient Air Quality Standard for carbon monoxide through the year 2003....

  15. 40 CFR 52.2353 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. Determination. EPA has determined that the Provo carbon monoxide “moderate” nonattainment area attained the carbon monoxide national ambient air quality standard by December 31, 1995....

  16. 40 CFR 52.1682 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) Approval—The November 13, 1992 revision to the carbon monoxide state implementation... attainment of the National Ambient Air Quality Standard for carbon monoxide through the year 2003....

  17. 40 CFR 52.2353 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 5 2014-07-01 2014-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. Determination. EPA has determined that the Provo carbon monoxide “moderate” nonattainment area attained the carbon monoxide national ambient air quality standard by December 31, 1995....

  18. 40 CFR 91.317 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Carbon monoxide analyzer calibration... Provisions § 91.317 Carbon monoxide analyzer calibration. (a) Calibrate the NDIR carbon monoxide analyzer... service and annually thereafter, check the NDIR carbon monoxide analyzer for response to water vapor...

  19. 40 CFR 52.2353 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. Determination. EPA has determined that the Provo carbon monoxide “moderate” nonattainment area attained the carbon monoxide national ambient air quality standard by December 31, 1995....

  20. Conversion of carbon-containing materials to carbon monoxide

    SciTech Connect

    Davis, G. D.; Hill, J. C.; Mcminn, T. D.; Rooks, C. W.

    1981-06-09

    Carbon-containing materials are gasified to produce high purity carbon monoxide in a three zone unified system (Oxidizer, reducer and gasifier) using a metal oxide as the oxygen and heat source for the gasification with carbon monoxide. Carbon monoxide contacts the metal oxide prior to the gasification to release the oxygen and convert the carbon monoxide to carbon dioxide as the gasification medium.

  1. Copper transport.

    PubMed

    Linder, M C; Wooten, L; Cerveza, P; Cotton, S; Shulze, R; Lomeli, N

    1998-05-01

    In adult humans, the net absorption of dietary copper is approximately 1 mg/d. Dietary copper joins some 4-5 mg of endogenous copper flowing into the gastrointestinal tract through various digestive juices. Most of this copper returns to the circulation and to the tissues (including liver) that formed them. Much lower amounts of copper flow into and out of other major parts of the body (including heart, skeletal muscle, and brain). Newly absorbed copper is transported to body tissues in two phases, borne primarily by plasma protein carriers (albumin, transcuprein, and ceruloplasmin). In the first phase, copper goes from the intestine to the liver and kidney; in the second phase, copper usually goes from the liver (and perhaps also the kidney) to other organs. Ceruloplasmin plays a role in this second phase. Alternatively, liver copper can also exit via the bile, and in a form that is less easily reabsorbed. Copper is also present in and transported by other body fluids, including those bathing the brain and central nervous system and surrounding the fetus in the amniotic sac. Ceruloplasmin is present in these fluids and may also be involved in copper transport there. The concentrations of copper and ceruloplasmin in milk vary with lactational stage. Parallel changes occur in ceruloplasmin messenger RNA expression in the mammary gland (as determined in pigs). Copper in milk ceruloplasmin appears to be particularly available for absorption, at least in rats.

  2. Aging Factsheets: Carbon Monoxide Poisoning Prevention

    EPA Pesticide Factsheets

    Everyone is at risk of being poisoned by carbon monoxide exposure. Older adults with pre-existing conditions, such as chronic heart disease, anemia, or respiratory problems, are even more susceptible to the effects of this odorless, colorless gas.

  3. Polymer-Based Carbon Monoxide Sensors

    NASA Technical Reports Server (NTRS)

    Homer, M. L.; Shevade, A. V.; Zhou, H.; Kisor, A. K.; Lara, L. M.; Yen, S.-P. S.; Ryan, M. A.

    2010-01-01

    Polymer-based sensors have been used primarily to detect volatile organics and inorganics; they are not usually used for smaller, gas phase molecules. We report the development and use of two types of polymer-based sensors for the detection of carbon monoxide. Further understanding of the experimental results is also obtained by performing molecular modeling studies to investigate the polymer-carbon monoxide interactions. The first type is a carbon-black-polymer composite that is comprised of a non-conducting polymer base that has been impregnated with carbon black to make it conducting. These chemiresistor sensors show good response to carbon monoxide but do not have a long lifetime. The second type of sensor has a non-conducting polymer base but includes both a porphyrin-functionalized polypyrrole and carbon black. These sensors show good, repeatable and reversible response to carbon monoxide at room temperature.

  4. Polymer-Based Carbon Monoxide Sensors

    NASA Technical Reports Server (NTRS)

    Homer, M. L.; Shevade, A. V.; Zhou, H.; Kisor, A. K.; Lara, L. M.; Yen, S.-P. S.; Ryan, M. A.

    2010-01-01

    Polymer-based sensors have been used primarily to detect volatile organics and inorganics; they are not usually used for smaller, gas phase molecules. We report the development and use of two types of polymer-based sensors for the detection of carbon monoxide. Further understanding of the experimental results is also obtained by performing molecular modeling studies to investigate the polymer-carbon monoxide interactions. The first type is a carbon-black-polymer composite that is comprised of a non-conducting polymer base that has been impregnated with carbon black to make it conducting. These chemiresistor sensors show good response to carbon monoxide but do not have a long lifetime. The second type of sensor has a non-conducting polymer base but includes both a porphyrin-functionalized polypyrrole and carbon black. These sensors show good, repeatable and reversible response to carbon monoxide at room temperature.

  5. A Fluorescent Source NDIR Carbon Monoxide Analyzer

    NASA Technical Reports Server (NTRS)

    Link, W. T.; McClatchie, E. A.; Watson, D. A.; Compher, A. B.

    1971-01-01

    This paper describes a new technique for measuring trace quantities of carbon monoxide by the nondispersive infrared (NDIR) methods. The technique uses the property of infrared fluorescence in a gas to generate a specific source of radiation which is an exact match of the absorption spectrum of the fundamental band of carbon monoxide. This results in an instrument with high sensitivity and specificity for CO. A novel method of referencing using an isotopic species of CO confers great stability on the instrument.

  6. Carbon-monoxide Indicators for Aircraft

    NASA Technical Reports Server (NTRS)

    Womack, S H J; Peterson, J B

    1936-01-01

    Several improvements that have been made on commercially available carbon-monoxide indicators to make them more suitable for aircraft use are described. These improvements include an automatic flow regulator, which permits the use of a simplified instrument on aircraft where a source of suction is available, and a more reliable alarm attachment. A field method for testing instruments on standard samples of carbon monoxide is described. Performance data and instructions in operation and maintenance are given.

  7. Carbon monoxide fixed point continuous monitor

    SciTech Connect

    Not Available

    1981-10-01

    This instrument is to monitor carbon monoxide concentration in underground mines. A carbon monoxide fixed-point continuous monitor consists of two modules. A line-powered control module is designed to power a remote transducer module; provide continuous readouts, visual and audible alarms, operational checks; and activate fans and equipment shutdown circuits if present CO concentration levels are exceeded. Details are given for the workings of each module. (DP)

  8. Device for staged carbon monoxide oxidation

    DOEpatents

    Vanderborgh, Nicholas E.; Nguyen, Trung V.; Guante, Jr., Joseph

    1993-01-01

    A method and apparatus for selectively oxidizing carbon monoxide in a hydrogen rich feed stream. The method comprises mixing a feed stream consisting essentially of hydrogen, carbon dioxide, water and carbon monoxide with a first predetermined quantity of oxygen (air). The temperature of the mixed feed/oxygen stream is adjusted in a first the heat exchanger assembly (20) to a first temperature. The mixed feed/oxygen stream is sent to reaction chambers (30,32) having an oxidation catalyst contained therein. The carbon monoxide of the feed stream preferentially absorbs on the catalyst at the first temperature to react with the oxygen in the chambers (30,32) with minimal simultaneous reaction of the hydrogen to form an intermediate hydrogen rich process stream having a lower carbon monoxide content than the feed stream. The elevated outlet temperature of the process stream is carefully controlled in a second heat exchanger assembly (42) to a second temperature above the first temperature. The process stream is then mixed with a second predetermined quantity of oxygen (air). The carbon monoxide of the process stream preferentially reacts with the second quantity of oxygen in a second stage reaction chamber (56) with minimal simultaneous reaction of the hydrogen in the process stream. The reaction produces a hydrogen rich product stream having a lower carbon monoxide content than the process stream. The product stream is then cooled in a third heat exchanger assembly (72) to a third predetermined temperature. Three or more stages may be desirable, each with metered oxygen injection.

  9. Electronic Transitions of Ruthenium Monoxide

    NASA Astrophysics Data System (ADS)

    Wang, Na; Ng, Y. W.; Cheung, A. S.-C.

    2013-06-01

    The electronic transition spectrum of ruthenium monoxide (RuO) molecule in the spectral region between 545nm to 640nm has been recorded and analyzed using laser ablation/reaction free-jet expansion and laser induced fluorescence spectroscopy. The RuO molecule was produced by reacting laser- ablated ruthenium atoms with N_{2}O seeded in argon. Nine vibrational bands were recorded and they are identified to be belonging to four electronic transition systems, namely the [18.1]Ω = 4 - X^{5} Δ_4 transition, [16.0]^{5} Φ_5 - X^{5} Δ_4 transition, [18.1]Ω = 3 - X^{5} Δ_3, and [15.8] ^{5} Φ_4 - X^{5} Δ_3 transition. RuO has been determined to have a X^{5} Δ_4 ground state. A least squares fit of the measured rotational lines yielded molecular constants for the ground and the low-lying electronic states. A molecular orbital energy level diagram has been used to help with the assignment of the observed electronic states.

  10. Intercalation and Push-Out Process with Spinel-to-Rocksalt Transition on Mg Insertion into Spinel Oxides in Magnesium Batteries.

    PubMed

    Okamoto, Shinya; Ichitsubo, Tetsu; Kawaguchi, Tomoya; Kumagai, Yu; Oba, Fumiyasu; Yagi, Shunsuke; Shimokawa, Kohei; Goto, Natsumi; Doi, Takayuki; Matsubara, Eiichiro

    2015-08-01

    On the basis of the similarity between spinel and rocksalt structures, it is shown that some spinel oxides (e.g., MgCo2O4, etc) can be cathode materials for Mg rechargeable batteries around 150 °C. The Mg insertion into spinel lattices occurs via "intercalation and push-out" process to form a rocksalt phase in the spinel mother phase. For example, by utilizing the valence change from Co(III) to Co(II) in MgCo2O4, Mg insertion occurs at a considerably high potential of about 2.9 V vs. Mg(2+)/Mg, and similarly it occurs around 2.3 V vs. Mg(2+)/Mg with the valence change from Mn(III) to Mn(II) in MgMn2O4, being comparable to the ab initio calculation. The feasibility of Mg insertion would depend on the phase stability of the counterpart rocksalt XO of MgO in Mg2X2O4 or MgX3O4 (X = Co, Fe, Mn, and Cr). In addition, the normal spinel MgMn2O4 and MgCr2O4 can be demagnesiated to some extent owing to the robust host structure of Mg1-xX2O4, where the Mg extraction/insertion potentials for MgMn2O4 and MgCr2O4 are both about 3.4 V vs. Mg(2+)/Mg. Especially, the former "intercalation and push-out" process would provide a safe and stable design of cathode materials for polyvalent cations.

  11. Intercalation and Push‐Out Process with Spinel‐to‐Rocksalt Transition on Mg Insertion into Spinel Oxides in Magnesium Batteries

    PubMed Central

    Okamoto, Shinya; Kawaguchi, Tomoya; Kumagai, Yu; Oba, Fumiyasu; Yagi, Shunsuke; Shimokawa, Kohei; Goto, Natsumi; Doi, Takayuki; Matsubara, Eiichiro

    2015-01-01

    On the basis of the similarity between spinel and rocksalt structures, it is shown that some spinel oxides (e.g., MgCo2O4, etc) can be cathode materials for Mg rechargeable batteries around 150 °C. The Mg insertion into spinel lattices occurs via “intercalation and push‐out” process to form a rocksalt phase in the spinel mother phase. For example, by utilizing the valence change from Co(III) to Co(II) in MgCo2O4, Mg insertion occurs at a considerably high potential of about 2.9 V vs. Mg2+/Mg, and similarly it occurs around 2.3 V vs. Mg2+/Mg with the valence change from Mn(III) to Mn(II) in MgMn2O4, being comparable to the ab initio calculation. The feasibility of Mg insertion would depend on the phase stability of the counterpart rocksalt XO of MgO in Mg2X2O4 or MgX3O4 (X = Co, Fe, Mn, and Cr). In addition, the normal spinel MgMn2O4 and MgCr2O4 can be demagnesiated to some extent owing to the robust host structure of Mg1−xX2O4, where the Mg extraction/insertion potentials for MgMn2O4 and MgCr2O4 are both about 3.4 V vs. Mg2+/Mg. Especially, the former “intercalation and push‐out” process would provide a safe and stable design of cathode materials for polyvalent cations. PMID:27980965

  12. Catalytic hydrogenation of carbon monoxide

    SciTech Connect

    Wayland, B.B.

    1992-12-01

    This project is focused on developing strategies to accomplish the reduction and hydrogenation of carbon monoxide to produce organic oxygenates at mild conditions. Our approaches to this issue are based on the recognition that rhodium macrocycles have unusually favorable thermodynamic values for producing a series of intermediate implicated in the catalytic hydrogenation of CO. Observations of metalloformyl complexes produced by reactions of H{sub 2} and CO, and reductive coupling of CO to form metallo {alpha}-diketone species have suggested a multiplicity of routes to organic oxygenates that utilize these species as intermediates. Thermodynamic and kinetic-mechanistic studies are used in constructing energy profiles for a variety of potential pathways, and these schemes are used in guiding the design of new metallospecies to improve the thermodynamic and kinetic factors for individual steps in the overall process. Variation of the electronic and steric effects associated with the ligand arrays along with the influences of the reaction medium provide the chemical tools for tuning these factors. Emerging knowledge of the factors that contribute to M-H, M-C and M-O bond enthalpies is directing the search for ligand arrays that will expand the range of metal species that have favorable thermodynamic parameters to produce the primary intermediates for CO hydrogenation. Studies of rhodium complexes are being extended to non-macrocyclic ligand complexes that emulate the favorable thermodynamic features associated with rhodium macrocycles, but that also manifest improved reaction kinetics. Multifunctional catalyst systems designed to couple the ability of rhodium complexes to produce formyl and diketone intermediates with a second catalyst that hydrogenates these imtermediates are promising approaches to accomplish CO hydrogenation at mild conditions.

  13. Wurtzite to rocksalt phase transformation of cadmium selenide nanocrystals via laser-induced shock waves: transition from single to multiple nucleation.

    PubMed

    Wittenberg, Joshua S; Merkle, Maxwell G; Alivisatos, A Paul

    2009-09-18

    The behavior of CdSe nanocrystals shocked to stresses of 2-3.75 GPa has been studied. Above 3 GPa a near-complete disappearance of the first excitonic feature and broadening of the low-energy absorption edge were observed, consistent with a wurtzite to rocksalt structural transformation. The transformation pressure is reduced relative to hydrostatic compression in a diamond anvil cell, and the rate increases, attributed to shock induced shear stress along the reaction coordinate. The especially rapid rate observed for a 3.75 GPa shock suggests multiple nucleation events per particle.

  14. Study of structural and electronic properties of ScN and ScAs in rocksalt and zincblende structure: A DFT approach

    SciTech Connect

    Nayak, Vikas Verma, U. P.

    2015-08-28

    In this paper, we have studied the structural and electronic properties of ScN and ScAs in zincblende (ZB) and rocksalt (RS) phases. We have employed the full potential linearized augmented plane wave (FP-APW) method within the density functional theory (DFT). Generalized gradient approximation (GGA), due to Perdew-Burke-Ernzerhof (PBE) has been used to estimate the exchange-correlation functional. Our band structure results for ScN shows the metallic nature, whereas ScAs shows the semiconducting behavior. The obtained results are in excellent agreement with earlier reported data.

  15. [Carbon monoxide contamination: an environmental health problem].

    PubMed

    Téllez, Jairo; Rodríguez, Alba; Fajardo, Alvaro

    2006-01-01

    Carbon monoxide is considered to be a major factor contaminating earth's atmosphere. The main sources producing this contamination are cars using gasoline or diesel fuel and industrial processes using carbon compounds; these two are responsible for 80% of carbon monoxide being emitted to the atmosphere. This substance has a well-known toxic effect on human beings and its acute poisonous effects (including death) have been widely studied; however, its long-term chronic effects are still not known. During the last few years, experimental research on animals and studies of human epidemiology have established the relationship between chronic exposure to low and middle levels of carbon monoxide in breathable air and adverse effects on human health, especially on organs consuming large amounts of oxygen such as the heart and brain. Harmful cardiovascular and neuropsychological effects have been documented in carbon monoxide concentration in air of less than 25 ppm and in carboxyhaemoglobin levels in blood of less than 10%. The main cardiac damage described to date has been high blood pressure, cardiac arrhythm and electrocardiograph signs of ischemia. Lack of memory, attention, concentration and Parkinson-type altered movement are the neuropsychological changes most frequently associated with chronic exposure to low levels of carbon monoxide and carboxyhaemoglobin.

  16. POLICY ASSESSMENT FOR THE CARBON MONOXIDE ...

    EPA Pesticide Factsheets

    As part of the NAAQS review process, a Risk/Exposure Assessment (REA) has been developed by OAQPS and has receieved inital review by the Clean Air Scientific Advisory Committee (CASAC). A second review of the REA will be conducted in March 2010. The Policy Assessment for the Carbon monoxide NAAQS Review is being developed and will include summaries of the findings of recent key scientific studies reviewed in the Integrated Science Assessment (ISA), will draw conclusions as to the adequacy of the existing carbon monoxide NAAQS for protection of public health, and will make recommendations regarding revision or reaffirmation of the carbon monoxide NAAQS. This work will be reviewed by the CASAC in March 2010. CASAC provides independent advice to the EPA Administrator on the technical bases for EPA's NAAQS. Presents implications for any needed changes to the carbon monoxide NAAQS, including human health risks and human population exposure associated with the carbon monoxide NAAQS and potential alternative ambient standards. (This work will be reviewed by the Clean Air Scientific Advisory Committee (CASAC). CASAC provides independent advice to the EPA Administrator on the technical bases for EPA's national ambient air quality standards. Established in 1977 under the Clean Air Act (CAA) Amendments of 1977 (see 42 U.S.C. § 7409(d)(2)), CASAC also addresses research related to air quality, sources of air pollution, and the strategies to attain and maintain air quality

  17. Engineering evidence for carbon monoxide toxicity cases.

    PubMed

    Galatsis, Kosmas

    2016-07-01

    Unintentional carbon monoxide poisonings and fatalities lead to many toxicity cases. Given the unusual physical properties of carbon monoxide-in that the gas is odorless and invisible-unorganized and erroneous methods in obtaining engineering evidence as required during the discovery process often occurs. Such evidence gathering spans domains that include building construction, appliance installation, industrial hygiene, mechanical engineering, combustion and physics. In this paper, we attempt to place a systematic framework that is relevant to key aspects in engineering evidence gathering for unintentional carbon monoxide poisoning cases. Such a framework aims to increase awareness of this process and relevant issues to help guide legal counsel and expert witnesses. © The Author(s) 2015.

  18. Dispersion strengthened copper

    DOEpatents

    Sheinberg, Haskell; Meek, Thomas T.; Blake, Rodger D.

    1990-01-01

    A composition of matter comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide, and a method for making this composition of matter.

  19. Dispersion strengthened copper

    DOEpatents

    Sheinberg, Haskell; Meek, Thomas T.; Blake, Rodger D.

    1989-01-01

    A composition of matter comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide, and a method for making this composition of matter.

  20. Optically Pumped Carbon Monoxide Cascade Laser

    DTIC Science & Technology

    2005-07-01

    absorption problems it poses. Instead, a 2.3 gtm GaSb diode laser could be used as a 1st overtone optically pumped source. The absorption cross section at...OPTICALLY PUMPED CARBON MONOXIDE CASCADE LASER BY NICHOLAS W. SAWRUK B.S., PHYSICS, US AIR FORCE ACADEMY, 2001 B.S., MATHEMATICS, US AIR FORCE...SUBTITLE 5. FUNDING NUMBERS OPTICALLY PUMPED CARBON MONOXIDE CASCADE LASER 6. AUTHOR(S) 1ST LT SAWRUK NICHOLAS W 7. PERFORMING ORGANIZATION NAME(S) AND

  1. [Carbon monoxide poisoning in children: never trivialize].

    PubMed

    Scalfaro, P; Haenggi, M H; Roulet, E; Gehri, M; Stucki, P; Schaller, M D; Cotting, J

    2000-03-01

    The risks linked to tissular hypoxemia after carbon monoxide (CO) poisoning are well known. Unawareness of CO exposure and of its complex pathophysiology may delay appropriate treatment and lead to long term neuropsychological sequelae. We report two cases of children treated in our institution and review the main issues regarding the optimal management. A high index of suspicion for carbon monoxide poisoning when dealing with an unclear neurological clinical presentation is mandatory. Classical therapy with normobaric 100% oxygen has to be instaured immediately. Hyperbaric oxygen therapy must be considered when anamnestic symptoms or clinical signs suggest neurological involvement even when carboxyhemoglobin values are low or already normalized.

  2. CPSC Warns of Carbon Monoxide Poisoning with Camping Equipment

    MedlinePlus

    ... Warns of Carbon Monoxide Poisoning Hazard with Camping Equipment The U.S. Consumer Product Safety Commission (CPSC) warns ... about the carbon monoxide (CO) hazard with camping equipment. CO can kill you! From 2002–2006, CPSC ...

  3. [Carbon monoxide metabolism by photosynthetic bacteria]. Progress report

    SciTech Connect

    Not Available

    1989-12-31

    Research continued on the metabolism of carbon monoxide by Rhodospirillum rubrum. This report discusses progress on the activity, induction, inhibition, and spectroscopic analysis of the enzyme Carbon Monoxide Dehydrogenase. (CBS)

  4. Half-metallic properties in rocksalt and zinc-blende M N ( M=Na, K): A first-principles study

    NASA Astrophysics Data System (ADS)

    Yan, E.

    2012-03-01

    Pseudopotentials and plane-wave basis set method is used to investigate the electronic structure and magnetic properties for state-of-the-art zinc-blende and rocksalt M N ( M=K, Na) alloys. We find that these compounds exhibit half-metallic characters with an integer magnetic moment of 2.00μB. The half-metallic properties result from a fully spin-polarization of s and p states. The origin of energy gap mainly comes from the hybridization both s and p states. Total energies calculations indicate the rocksalt phase is lower in energy than the zinc-blende one. The difference of total energy are about 0.035 Ry per formula unit for KN and NaN, respectively. For these compounds, Slater-Pauling curve Mt=(Zt-4) (in μB unit) is obeyed between valence electrons and total magnetic moment. Meanwhile, we also find the preservation of half metallic characters when the lattice parameter is moderate compressed.

  5. Copper Metallochaperones

    PubMed Central

    Robinson, Nigel J.; Winge, Dennis R.

    2014-01-01

    The current state of knowledge on how copper metallochaperones support the maturation of cuproproteins is reviewed. Copper is needed within mitochondria to supply the CuA and intramembrane CuB sites of cytochrome oxidase, within the trans-Golgi network to supply secreted cuproproteins and within the cytosol to supply superoxide dismutase 1 (Sod1). Subpopulations of copper-zinc superoxide dismutase also localize to mitochondria, the secretory system, the nucleus and, in plants, the chloroplast, which also requires copper for plastocyanin. Prokaryotic cuproproteins are found in the cell membrane and in the periplasm of gram-negative bacteria. Cu(I) and Cu(II) form tight complexes with organic molecules and drive redox chemistry, which unrestrained would be destructive. Copper metallochaperones assist copper in reaching vital destinations without inflicting damage or becoming trapped in adventitious binding sites. Copper ions are specifically released from copper metallochaperones upon contact with their cognate cuproproteins and metal transfer is thought to proceed by ligand substitution. PMID:20205585

  6. 40 CFR 52.376 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... submitted a revision to the carbon monoxide State Implementation Plan for the 1990 base year emission... a revision to the carbon monoxide State Implementation Plan for the 1993 periodic emission inventory...-level carbon monoxide evaluations of transportation projects in each area are carried out as part of...

  7. 40 CFR 52.376 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... submitted a revision to the carbon monoxide State Implementation Plan for the 1990 base year emission... a revision to the carbon monoxide State Implementation Plan for the 1993 periodic emission inventory...-level carbon monoxide evaluations of transportation projects in each area are carried out as part of...

  8. 40 CFR 52.1528 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... maintenance plan include a base year (1990 attainment year) emission inventory for carbon monoxide, a demonstration of maintenance of the carbon monoxide NAAQS with projected emission inventories to the year 2010... of 55.83 tons per day for carbon monoxide to be used in determining transportation conformity for the...

  9. 21 CFR 868.1430 - Carbon monoxide gas analyzer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carbon monoxide gas analyzer. 868.1430 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1430 Carbon monoxide gas analyzer. (a) Identification. A carbon monoxide gas analyzer is a device intended to measure the concentration of...

  10. 40 CFR 89.320 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Carbon monoxide analyzer calibration... Test Equipment Provisions § 89.320 Carbon monoxide analyzer calibration. (a) Calibrate the NDIR carbon... introduction into service and annually thereafter, the NDIR carbon monoxide analyzer shall be checked...

  11. 40 CFR 52.1185 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) Approval—On November 24, 1994, the Michigan Department of Natural Resources submitted a revision to the carbon monoxide State Implementation Plan. The submittal pertained to a plan...

  12. 21 CFR 177.1312 - Ethylene-carbon monoxide copolymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-carbon monoxide copolymers. 177.1312... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1312 Ethylene-carbon monoxide copolymers. The ethylene-carbon monoxide copolymers identified in paragraph (a) of this section may be...

  13. 40 CFR 52.349 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Control strategy: Carbon monoxide. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.349 Control strategy: Carbon monoxide. (a) Revisions to the Colorado State Implementation Plan, Carbon Monoxide Redesignation...

  14. 21 CFR 177.1312 - Ethylene-carbon monoxide copolymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ethylene-carbon monoxide copolymers. 177.1312... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1312 Ethylene-carbon monoxide copolymers. The ethylene-carbon monoxide copolymers identified in paragraph (a) of this section may be...

  15. 40 CFR 52.1373 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) On July 8, 1997, the Governor of Montana submitted revisions to the SIP narrative for the Missoula carbon monoxide control plan. (b) Revisions to the Montana State Implementation...

  16. 40 CFR 52.1185 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) Approval—On November 24, 1994, the Michigan Department of Natural Resources submitted a revision to the carbon monoxide State Implementation Plan. The submittal pertained to a plan...

  17. 40 CFR 52.1373 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) On July 8, 1997, the Governor of Montana submitted revisions to the SIP narrative for the Missoula carbon monoxide control plan. (b) Revisions to the Montana State Implementation...

  18. 75 FR 4815 - Integrated Science Assessment for Carbon Monoxide

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-29

    ... AGENCY Integrated Science Assessment for Carbon Monoxide AGENCY: Environmental Protection Agency (EPA... availability of a final document titled, ``Integrated Science Assessment for Carbon Monoxide'' (EPA/600/R-09... standards (NAAQS) for carbon monoxide. DATES: The document will be available on January 29, 2010....

  19. 21 CFR 868.1430 - Carbon monoxide gas analyzer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carbon monoxide gas analyzer. 868.1430 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1430 Carbon monoxide gas analyzer. (a) Identification. A carbon monoxide gas analyzer is a device intended to measure the concentration of...

  20. 40 CFR 86.522-78 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Carbon monoxide analyzer calibration... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.522-78 Carbon monoxide analyzer... thereafter the NDIR carbon monoxide analyzer shall be checked for response to water vapor and CO2: (1)...

  1. 40 CFR 86.122-78 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Carbon monoxide analyzer calibration... Complete Heavy-Duty Vehicles; Test Procedures § 86.122-78 Carbon monoxide analyzer calibration. The NDIR carbon monoxide analyzer shall receive the following initial and periodic calibrations: (a) Initial...

  2. 40 CFR 86.522-78 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Carbon monoxide analyzer calibration... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.522-78 Carbon monoxide analyzer... thereafter the NDIR carbon monoxide analyzer shall be checked for response to water vapor and CO2: (1)...

  3. 40 CFR 52.1373 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) On July 8, 1997, the Governor of Montana submitted revisions to the SIP narrative for the Missoula carbon monoxide control plan. (b) Revisions to the Montana State Implementation...

  4. 40 CFR 52.1373 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) On July 8, 1997, the Governor of Montana submitted revisions to the SIP narrative for the Missoula carbon monoxide control plan. (b) Revisions to the Montana State Implementation...

  5. 40 CFR 52.1185 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) Approval—On November 24, 1994, the Michigan Department of Natural Resources submitted a revision to the carbon monoxide State Implementation Plan. The submittal pertained to a plan...

  6. 40 CFR 89.320 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Carbon monoxide analyzer calibration... Test Equipment Provisions § 89.320 Carbon monoxide analyzer calibration. (a) Calibrate the NDIR carbon... introduction into service and annually thereafter, the NDIR carbon monoxide analyzer shall be checked...

  7. 21 CFR 868.1430 - Carbon monoxide gas analyzer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carbon monoxide gas analyzer. 868.1430 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1430 Carbon monoxide gas analyzer. (a) Identification. A carbon monoxide gas analyzer is a device intended to measure the concentration of...

  8. 21 CFR 868.1430 - Carbon monoxide gas analyzer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carbon monoxide gas analyzer. 868.1430 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1430 Carbon monoxide gas analyzer. (a) Identification. A carbon monoxide gas analyzer is a device intended to measure the concentration of...

  9. 40 CFR 52.1373 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) On July 8, 1997, the Governor of Montana submitted revisions to the SIP narrative for the Missoula carbon monoxide control plan. (b) Revisions to the Montana State Implementation...

  10. 40 CFR 52.1887 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) Part D—Approval—The following portions of the Ohio plan are approved: (1) The carbon...) The carbon monoxide attainment and reasonable further progress demonstrations for the following...

  11. 40 CFR 52.1887 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) Part D—Approval—The following portions of the Ohio plan are approved: (1) The carbon...) The carbon monoxide attainment and reasonable further progress demonstrations for the following...

  12. 40 CFR 52.1185 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) Approval—On November 24, 1994, the Michigan Department of Natural Resources submitted a revision to the carbon monoxide State Implementation Plan. The submittal pertained to a plan...

  13. 40 CFR 89.320 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Carbon monoxide analyzer calibration... Test Equipment Provisions § 89.320 Carbon monoxide analyzer calibration. (a) Calibrate the NDIR carbon... introduction into service and annually thereafter, the NDIR carbon monoxide analyzer shall be checked...

  14. 40 CFR 86.522-78 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Carbon monoxide analyzer calibration... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.522-78 Carbon monoxide analyzer... thereafter the NDIR carbon monoxide analyzer shall be checked for response to water vapor and CO2: (1)...

  15. 40 CFR 52.1185 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) Approval—On November 24, 1994, the Michigan Department of Natural Resources submitted a revision to the carbon monoxide State Implementation Plan. The submittal pertained to a plan...

  16. 40 CFR 52.349 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Control strategy: Carbon monoxide. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.349 Control strategy: Carbon monoxide. (a) Revisions to the Colorado State Implementation Plan, Carbon Monoxide Redesignation...

  17. 40 CFR 86.522-78 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Carbon monoxide analyzer calibration... Regulations for 1978 and Later New Motorcycles; Test Procedures § 86.522-78 Carbon monoxide analyzer... thereafter the NDIR carbon monoxide analyzer shall be checked for response to water vapor and CO2: (1)...

  18. 40 CFR 52.349 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Control strategy: Carbon monoxide. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.349 Control strategy: Carbon monoxide. (a) Revisions to the Colorado State Implementation Plan, Carbon Monoxide Redesignation...

  19. 40 CFR 90.317 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Carbon monoxide analyzer calibration... Emission Test Equipment Provisions § 90.317 Carbon monoxide analyzer calibration. (a) Calibrate the NDIR carbon monoxide analyzer as described in this section. (b) Initial and periodic interference. Prior...

  20. 21 CFR 868.1430 - Carbon monoxide gas analyzer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carbon monoxide gas analyzer. 868.1430 Section 868...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1430 Carbon monoxide gas analyzer. (a) Identification. A carbon monoxide gas analyzer is a device intended to measure the concentration of...

  1. 40 CFR 86.1322-84 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Carbon monoxide analyzer calibration... Exhaust Test Procedures § 86.1322-84 Carbon monoxide analyzer calibration. The NDIR carbon monoxide... interference check. Prior to its introduction into service and annually thereafter, the NDIR carbon...

  2. 21 CFR 177.1312 - Ethylene-carbon monoxide copolymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ethylene-carbon monoxide copolymers. 177.1312... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1312 Ethylene-carbon monoxide copolymers. The ethylene-carbon monoxide copolymers identified in paragraph (a) of this section may be...

  3. 40 CFR 52.349 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Control strategy: Carbon monoxide. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.349 Control strategy: Carbon monoxide. (a) Revisions to the Colorado State Implementation Plan, Carbon Monoxide Redesignation...

  4. 40 CFR 90.317 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Carbon monoxide analyzer calibration... Emission Test Equipment Provisions § 90.317 Carbon monoxide analyzer calibration. (a) Calibrate the NDIR carbon monoxide analyzer as described in this section. (b) Initial and periodic interference. Prior...

  5. 21 CFR 177.1312 - Ethylene-carbon monoxide copolymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ethylene-carbon monoxide copolymers. 177.1312... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1312 Ethylene-carbon monoxide copolymers. The ethylene-carbon monoxide copolymers identified in paragraph (a) of this section may be...

  6. 40 CFR 52.1887 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) Part D—Approval—The following portions of the Ohio plan are approved: (1) The carbon...) The carbon monoxide attainment and reasonable further progress demonstrations for the following...

  7. Graphite cloth facilitates vacuum evaporation of silicon monoxide

    NASA Technical Reports Server (NTRS)

    Carithers, M. D.

    1968-01-01

    Woven graphite cloth facilitates the vacuum deposition of thin films of silicon monoxide on substrate surfaces. The cloth serves both as a container and electric heating element for the silicon monoxide. It minimizes and prevents the silicon monoxide particle ejection, provides uniform heat distribution, and cools rapidly by radiation.

  8. Neurological manifestation of carbon monoxide poisoning.

    PubMed Central

    Hart, I. K.; Kennedy, P. G.; Adams, J. H.; Cunningham, N. E.

    1988-01-01

    The clinical signs and post-mortem findings in a case of carbon monoxide poisoning are described, and correlated with the computer tomographic (CT) scan appearances. The value of serial CT scanning as a diagnostic tool is highlighted. Images Figure 1 Figure 2 PMID:3174539

  9. Removing Silicon Monoxide From Nickel Mirrors

    NASA Technical Reports Server (NTRS)

    Zaniewski, John J.

    1987-01-01

    Combination of polishing tool and polishing mixture used to remove adherent fragments of silicon monoxide protective coatings from nickel/aluminum mirrors without altering shapes or harming polishes of mirror surfaces. Polishing technique developed to prepare stained mirrors for recoating to restore high reflectance.

  10. Carbon Monoxide Poisoning in an Elementary School

    ERIC Educational Resources Information Center

    Comfort, Robert J.; Daveler, Jay

    1977-01-01

    Described is an investigation conducted by municipal inspection and code enforcement personnel following an episode of carbon monoxide poisoning among elementary school children in a small eastern Pennsylvania community in 1975. The need for a reevaluation of existing building code standards is emphasized. (BT)

  11. Carbon Monoxide, A Bibliography With Abstracts.

    ERIC Educational Resources Information Center

    Cooper, Anna Grossman

    Included is a review of the carbon monoxide related literature published from 1880 to 1966. The 983 references with abstracts are grouped into these broad categories: Analysis, Biological Effects, Blood Chemistry, Control, Criteria and Standards, Instruments and Techniques, Sampling and Network Operations, and Sources. The Biological Effects group…

  12. Carbon Monoxide, A Bibliography With Abstracts.

    ERIC Educational Resources Information Center

    Cooper, Anna Grossman

    Included is a review of the carbon monoxide related literature published from 1880 to 1966. The 983 references with abstracts are grouped into these broad categories: Analysis, Biological Effects, Blood Chemistry, Control, Criteria and Standards, Instruments and Techniques, Sampling and Network Operations, and Sources. The Biological Effects group…

  13. Method and apparatus for selective removal of carbon monoxide

    DOEpatents

    Borup, Rodney L.; Skala, Glenn W.; Brundage, Mark A.; LaBarge, William J.

    2000-01-01

    There is provided a method and apparatus for treatment of a hydrogen-rich gas to reduce the carbon monoxide content thereof by reacting the carbon monoxide in the gas with an amount of oxygen sufficient to oxidize at least a portion of the carbon monoxide in the presence of a catalyst in a desired temperature range without substantial reaction of hydrogen. The catalyst is an iridium-based catalyst dispersed on, and supported on, a carrier. In the presence of the catalyst, carbon monoxide in a hydrogen-rich feed gas is selectively oxidized such that a product stream is produced with a very low carbon monoxide content.

  14. Rock-salt structure lithium deuteride formation in liquid lithium with high-concentrations of deuterium: a first-principles molecular dynamics study

    SciTech Connect

    Chen, Mohan; Abrams, T.; Jaworski, M. A.; Carter, Emily A.

    2015-12-17

    Because of lithium's possible use as a first wall material in a fusion reactor, a fundamental understanding of the interactions between liquid lithium (Li) and deuterium (D) is important. Here, we predict structural and dynamical properties of liquid Li samples with high concentrations of D, as derived from first-principles molecular dynamics simulations. Liquid Li samples with four concentrations of inserted D atoms (LiD$_{\\beta}$ , $\\beta =0.25$ , 0.50, 0.75, and 1.00) are studied at temperatures ranging from 470 to 1143 K. Densities, diffusivities, pair distribution functions, bond angle distribution functions, geometries, and charge transfer between Li and D atoms are calculated and analyzed. The analysis suggests liquid–solid phase transitions can occur at some concentrations and temperatures, forming rock-salt LiD within liquid Li. Finally, we observed the formation of some D2 molecules at high D concentrations.

  15. Rock-salt structure lithium deuteride formation in liquid lithium with high-concentrations of deuterium: a first-principles molecular dynamics study

    DOE PAGES

    Chen, Mohan; Abrams, T.; Jaworski, M. A.; ...

    2015-12-17

    Because of lithium's possible use as a first wall material in a fusion reactor, a fundamental understanding of the interactions between liquid lithium (Li) and deuterium (D) is important. Here, we predict structural and dynamical properties of liquid Li samples with high concentrations of D, as derived from first-principles molecular dynamics simulations. Liquid Li samples with four concentrations of inserted D atoms (LiDmore » $$_{\\beta}$$ , $$\\beta =0.25$$ , 0.50, 0.75, and 1.00) are studied at temperatures ranging from 470 to 1143 K. Densities, diffusivities, pair distribution functions, bond angle distribution functions, geometries, and charge transfer between Li and D atoms are calculated and analyzed. The analysis suggests liquid–solid phase transitions can occur at some concentrations and temperatures, forming rock-salt LiD within liquid Li. Finally, we observed the formation of some D2 molecules at high D concentrations.« less

  16. Enhanced hardness in epitaxial TiAlScN alloy thin films and rocksalt TiN/(Al,Sc)N superlattices

    SciTech Connect

    Saha, Bivas; Lawrence, Samantha K.; Bahr, David F.; Schroeder, Jeremy L.; Birch, Jens; Sands, Timothy D.

    2014-10-13

    High hardness TiAlN alloys for wear-resistant coatings exhibit limited lifetimes at elevated temperatures due to a cubic-AlN to hexagonal-AlN phase transformation that leads to decreasing hardness. We enhance the hardness (up to 46 GPa) and maximum operating temperature (up to 1050 °C) of TiAlN-based coatings by alloying with scandium nitride to form both an epitaxial TiAlScN alloy film and epitaxial rocksalt TiN/(Al,Sc)N superlattices on MgO substrates. The superlattice hardness increases with decreasing period thickness, which is understood by the Orowan bowing mechanism of the confined layer slip model. These results make them worthy of additional research for industrial coating applications.

  17. Growth of rocksalt-structured Mg x Zn1- x O (x > 0.5) films on MgO substrates and their deep-ultraviolet luminescence

    NASA Astrophysics Data System (ADS)

    Kaneko, Kentaro; Onuma, Takeyoshi; Tsumura, Keiichi; Uchida, Takayuki; Jinno, Riena; Yamaguchi, Tomohiro; Honda, Tohru; Fujita, Shizuo

    2016-11-01

    Single-phase rocksalt-structured Mg x Zn1- x O (x > 0.5) alloy films were grown on MgO substrates using the mist chemical vapor deposition method. A specular surface with a step and terrace structure was obtained. The bandgap was tuned from 5.9 to 7.8 eV as x varied from 0.5 to 1. Deep ultraviolet cathodoluminescence, stemming from near band edge transitions, was observed for Mg0.57Zn0.43O in the 4.8-5.5 eV range, peaking at ˜5.1 eV (˜240 nm) in the 12-100 K range.

  18. Triaxial-compression tests on rocksalt at temperatures from 50° to 200°c and strain rates from 10-4 to 10-9/s

    NASA Astrophysics Data System (ADS)

    Horseman, S. T.; Handin, J.

    Using screw-driven machines with exceptionally reliable data-acquisition and confining-pressure systems and an uninterruptible power-supply, we have tested 10 by 20-cm specimens of Avery Island rocksalt at constant strain-rates down to 10-9/s. At strains between 0.05 and 0.10, steady-state flow is achieved at about 6.8 MPa at 200°C and 10-7/s and 9.4 MPa at 100°C and 10-8/s. At 10-9/s a strain of only 0.03 has so far been reached after 3 × 107s (about 350 days); tests at 50° and 100°C are to continue for another 100 days unless steady-state flow is surely observed sooner.

  19. Density functional study of the optical response of FeN and CoN nitrides with zinc-blend and rock-salt structures

    NASA Astrophysics Data System (ADS)

    Cheballah, Y.; Ziane, A.; Bouarab, S.; Vega, A.

    2017-01-01

    We investigated the optical properties of iron and cobalt mono-nitrides in rock-salt and zinc-blende crystal structures. Density functional theoretic calculations were performed using the linear muffin tin orbital method in the generalized gradient approximation for exchange and correlation. The optical response was characterized by means of the dielectric function, calculated for each structural phase in the different magnetic arrangements found experimentally and theoretically. The origin of the main absorption peaks was traced back to particular interband transitions after a careful analysis of the band structures and orbital- and atom- projected electronic densities of states. The optical response of both nitrides with this structure in the nomagnetic state is very similar at photon frequencies below 2 eV, but differ at high frequencies. In zinc-blende structure, both compounds are nomagnetic and present an optical gap of about 0.5 eV for interband transitions in their optical response.

  20. Synthesis and characterization of novel rocksalt-type oxynitrides, LiTi nO xN y ( n=1, 2, 3, 4 and 8)

    NASA Astrophysics Data System (ADS)

    Katsumata, Tetsuhiro; Takaki, Seiko; Inaguma, Yoshiyuki; Shan, Yue Jin

    2004-12-01

    Novel oxynitrides, LiTi nO xN y ( n=1, 2, 3, 4 and 8) were synthesized by sintering under NH 3 gas atmosphere. These compounds have rocksalt-type structure and the existence of cation vacancies is suggested. While the lattice parameters of these compound slightly vary, obvious tendency for the Li or nitride content is not found. For these compounds, the temperature dependence of the electronic conductivity shows the semiconducting behavior. However, the measurement of magnetic susceptibility and the Seebeck coefficient suggest that the transport in these compound is metallic. The electric conductivity seems to be dominated by the resistance of the grain boundary and the transport property of these compounds is metallic.

  1. Basal ganglia lesions following carbon monoxide poisoning.

    PubMed

    Hopkins, Ramona O; Fearing, Michael A; Weaver, Lindell K; Foley, John F

    2006-03-01

    Carbon monoxide (CO) is the most common cause of poisoning and may result in basal ganglia lesions. This study reviewed the literature of carbon monoxide poisoning and basal ganglia lesions and prospectively assessed the prevalence of basal ganglia lesions in a cohort of patients with CO poisoning. Literature review and prospective cohort study. This study conducted a comprehensive review of the literature and assessed 73 CO-poisoned patients for basal ganglia lesions on sequential MR scans. Magnetic resonance scans were obtained on day 1, 2 weeks and 6 months post-CO poisoning. The literature review found basal ganglia lesions occur in 4-88% of subjects. Only one patient was found with globus pallidus lesions at 2 weeks and 6 months following CO poisoning, that were not present on the initial day 1 MR scan. Basal ganglia lesions, including lesions of the globus pallidus, may be less common than previously reported.

  2. Enhanced carbon monoxide utilization in methanation process

    DOEpatents

    Elek, Louis F.; Frost, Albert C.

    1984-01-01

    Carbon monoxide - containing gas streams are passed over a catalyst to deposit a surface layer of active surface carbon thereon essentially without the formation of inactive coke. The active carbon is subsequently reacted with steam or hydrogen to form methane. Surprisingly, hydrogen and water vapor present in the feed gas do not adversely affect CO utilization significantly, and such hydrogen actually results in a significant increase in CO utilization.

  3. Detection of carbon monoxide in Jupiter

    NASA Technical Reports Server (NTRS)

    Beer, R.

    1975-01-01

    New, ground-based, 5-micron spectra of Jupiter have revealed the presence of a trace quantity of carbon monoxide in the lower atmosphere of the planet. A preliminary analysis suggests a number mixing ratio in the neighborhood of 10 to the minus ninth power and a column abundance of roughly 5 times 10 to the 17th power molecules per sq cm to a depth of at least 2 atmospheres. It is suggested that the observation might be confirmed by microwave techniques.

  4. The oxidation of carbon monoxide on polycrystalline rhodium under knudsen conditions. II. Reaction with nitrogen monoxide

    NASA Astrophysics Data System (ADS)

    Lintz, Hans-Günther; Weisker, Tilman

    1985-09-01

    The reaction between carbon monoxide and nitrogen monoxide on a polycrystalline rhodium ribbon under stationary conditions is followed by mass spectrometry. In the temperature range 300 to 1100 K the ratio of the partial pressures of the reactants varies between 0.1 < pNO/ pCO < 100 at values of the total pressure in the reactor from 10 -4 to 10 -5 Torr. The results can be interpreted qualitatively by a simple elementary reaction sequence. Simulation using literature values of the kinetic constants leads to semi-quantitative agreement with experimental results. No isothermal oscillations of the reaction rate could be observed under the stated conditions.

  5. 40 CFR 86.522-78 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the manufacturer's instructions for instrument startup and operation. Adjust the analyzer to optimize... carbon monoxide analyzer shall be calibrated. (1) Adjust the analyzer to optimize performance. (2) Zero...

  6. Copper cyanide

    Integrated Risk Information System (IRIS)

    Copper cyanide ; CASRN 544 - 92 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  7. Carbon Monoxide Exposure in Youth Ice Hockey.

    PubMed

    Macnow, Theodore; Mannix, Rebekah; Meehan, William P

    2016-11-02

    To examine the effect of ice resurfacer type on carboxyhemoglobin levels in youth hockey players. We hypothesized that players in arenas with electric resurfacers would have normal, stable carboxyhemoglobin levels during games, whereas those in arenas with internal combustion engine (IC) resurfacers would have an increase in carboxyhemoglobin levels. Prospective cohort study. Enclosed ice arenas in the northeastern United States. Convenience sample of players aged 8 to 18 years old in 16 games at different arenas. Eight arenas (37 players) used an IC ice resurfacer and 8 arenas (36 players) an electric resurfacer. Carboxyhemoglobin levels (SpCO) were measured using a pulse CO-oximeter before and after the game. Arena air was tested for carbon monoxide (CO) using a metered gas detector. Players completed symptom questionnaires. The change in SpCO from pregame to postgame was compared between players at arenas with electric versus IC resurfacers. Carbon monoxide was present at 6 of 8 arenas using IC resurfacers, levels ranged from 4 to 42 parts per million. Carbon monoxide was not found at arenas with electric resurfacers. Players at arenas with IC resurfacers had higher median pregame SpCO levels compared with those at electric arenas (4.3% vs 1%, P < 0.01). Players in the IC group also had a significant increase in their SpCO level during a hockey game compared with those in the electric group (2.8% vs 1%, P = 0.01). There were no significant differences in symptom scores. Players at arenas operating IC resurfacers had significantly higher SpCO levels. Youth hockey players in arenas with IC resurfacers have an increase in carboxyhemoglobin during games and have elevated baseline carboxyhemoglobin levels compared with players at arenas with electric resurfacers. Electric resurfacers decrease the risk of CO exposure.

  8. Carbon monoxide poisoning in racing car drivers.

    PubMed

    Holley, J E; Butler, J W; Mahoney, J M

    1999-03-01

    To determine if carbon monoxide (CO) exposure during competition racing is significant enough to cause post-racing symptoms among professional racing drivers. Closed vehicle professional racing drivers were questioned after competition regarding symptoms consistent with heat exposure, dehydration, and carbon monoxide poisoning. All drivers, regardless of symptoms, underwent expired CO monitoring using a breath analyzer both before and after competition events. CO measurements were performed prior to any post-race interviews. Driver smoking history, laps at low speed (under caution), cockpit fire or damage to the exhaust system were also noted. An association between driver symptoms, track and vehicle condition, and increases in expired CO levels during racing was sought. Twenty-eight drivers completed the study. Each driver was tested both before and after each competition event, and some drivers were tested at different tracks. All of the tested drivers experienced an increase in carboxyhemoglobin concentrations during the competition event. Drivers who smoked had higher baseline levels than non-smokers, but were no more likely to have symptoms. The driver with the highest post-race CO level was exposed to a fire which completely destroyed the vehicle, but he complained of no symptoms after the race. Most drivers complained of post-race symptoms or appeared symptomatic, but no correlation could be shown between post-race CO levels and symptoms. There is a mild increase in driver CO levels during professional road racing competition, however, no correlation with CO level and driver symptomatology can be demonstrated. Carbon monoxide does not appear to be a significant cause of post-race driver symptoms such as fatigue, nausea, headache, and weakness.

  9. Optically Pumped Carbon Monoxide Cascade Laser

    DTIC Science & Technology

    2005-06-30

    bother with the small absorption cross-sections of 2nd overtone pumping and the absorption problems it poses. Instead, a 2.3 µm GaSb diode laser ...could be used as a 1 st overtone optically pumped source. The absorption cross section at 2.3 µm is over 100 times larger. The 2.3 µm diode laser is...AFRL-DE-PS- AFRL-DE-PS- TR-2005-1093 TR-2005-1093 OPTICALLY PUMPED CARBON MONOXIDE CASCADE LASER NICHOLAS W. SAWRUK 30 June 2005 Final Report

  10. Accidental carbon monoxide poisoning in our homes.

    PubMed

    Sharma, Shruti; Gupta, Rahul; Paul, Barinder S; Puri, Sandeep; Garg, Shuchita

    2009-01-01

    Carbon monoxide (CO) is a colorless, odorless, tasteless, nonirritating, but significantly toxic gas. It is a product of combustion of organic matter in presence of insufficient oxygen supply. Symptoms of mild poisoning include headaches, vertigo and flu like effects, whereas larger exposures can lead to significant toxicity of the central nervous system (CNS), heart, and even death. We are reporting two cases that presented to us in the winter months of December to January with history, sign, symptoms, and radiological evidence of suspected CO poisoning.

  11. CO (Carbon Monoxide Mixing Ratio System) Handbook

    SciTech Connect

    Biraud, S

    2011-02-23

    The main function of the CO instrument is to provide continuous accurate measurements of carbon monoxide mixing ratio at the ARM SGP Central Facility (CF) 60-meter tower (36.607 °N, 97.489 °W, 314 meters above sea level). The essential feature of the control and data acquisition system is to record signals from a Thermo Electron 48C and periodically calibrate out zero and span drifts in the instrument using the combination of a CO scrubber and two concentrations of span gas (100 and 300 ppb CO in air). The system was deployed on May 25, 2005.

  12. [Carbon monoxide poisoning by a heating system].

    PubMed

    Dietz, Eric; Gehl, Axel; Friedrich, Peter; Kappus, Stefan; Petter, Franz; Maurer, Klaus; Püschel, Klaus

    2016-01-01

    A case of accidental carbon monoxide poisoning in several occupants of two neighboring residential buildings in Hamburg-Harburg (Germany) caused by a defective gas central heating system is described. Because of leaks in one of the residential buildings and the directly adjacent wall of the neighboring house, the gas could spread and accumulated in both residential buildings, which resulted in a highly dangerous situation. Exposure to the toxic gas caused mild to severe intoxication in 15 persons. Three victims died still at the site of the accident. Measures to protect the occupants were taken only with a great delay. As symptoms were unspecific, it was not realized that the various alarms given by persons involved in the accident were related to the same cause. In order to take appropriate measures in time it is indispensible to recognize, assess and check potential risks, which can be done by using carbon monoxide warning devices and performing immediate COHb measurements with special pulse oximeters on site. Moreover, the COHb content in the blood should be routinely determined in all patients admitted to an emergency department with unspecific symptoms.

  13. Hyperbaric oxygen therapy for carbon monoxide poisoning.

    PubMed

    Weaver, Lindell K

    2014-01-01

    Despite established exposure limits and safety standards, and the availability of carbon monoxide (CO) alarms, each year 50,000 people in the United States visit emergency departments for CO poisoning. Carbon monoxide poisoning can occur from brief exposures to high levels of CO, or from longer exposures to lower levels. Common symptoms include headaches, nausea and vomiting, dizziness, general malaise, and altered mental status. Some patients may have chest pain, shortness of breath and myocardial ischemia, and may require mechanical ventilation and treatment of shock. Individuals poisoned by CO often go on to develop neurological problems, including cognitive sequelae, anxiety and depression, persistent headaches, dizziness, sleep problems, motor weakness, vestibular and balance problems, gaze abnormalities, peripheral neuropathies, hearing loss, tinnitus and Parkinsonian-like syndrome. While breathing oxygen hastens the removal of carboxyhemoglobin (COHb), hyperbaric oxygen (HBO2) hastens COHb elimination and favorably modulates inflammatory processes instigated by CO poisoning, an effect not observed with breathing normobaric oxygen. Hyperbaric oxygen improves mitochondrial function, inhibits lipid peroxidation transiently, impairs leukocyte adhesion to injured microvasculature, and reduces brain inflammation caused by the CO-induced adduct formation of myelin basic protein. Based upon three supportive randomized clinical trials in humans and considerable evidence from animal studies, HBO2 should be considered for all cases of acute symptomatic CO poisoning. Hyperbaric oxygen is indicated for CO poisoning complicated by cyanide poisoning, often concomitantly with smoke inhalation.

  14. Carbon Monoxide Dehydrogenase Activity in Bradyrhizobium japonicum

    PubMed Central

    Lorite, María J.; Tachil, Jörg; Sanjuán, Juán; Meyer, Ortwin; Bedmar, Eulogio J.

    2000-01-01

    Bradyrhizobium japonicum strain 110spc4 was capable of chemolithoautotrophic growth with carbon monoxide (CO) as a sole energy and carbon source under aerobic conditions. The enzyme carbon monoxide dehydrogenase (CODH; EC 1.2.99.2) has been purified 21-fold, with a yield of 16% and a specific activity of 58 nmol of CO oxidized/min/mg of protein, by a procedure that involved differential ultracentrifugation, anion-exchange chromatography, hydrophobic interaction chromatography, and gel filtration. The purified enzyme gave a single protein and activity band on nondenaturing polyacrylamide gel electrophoresis and had a molecular mass of 230,000 Da. The 230-kDa enzyme was composed of large (L; 75-kDa), medium (M; 28.4-kDa), and small (S; 17.2-kDa) subunits occurring in heterohexameric (LMS)2 subunit composition. The 75-kDa polypeptide exhibited immunological cross-reactivity with the large subunit of the CODH of Oligotropha carboxidovorans. The B. japonicum enzyme contained, per mole, 2.29 atoms of Mo, 7.96 atoms of Fe, 7.60 atoms of labile S, and 1.99 mol of flavin. Treatment of the enzyme with iodoacetamide yielded di(carboxamidomethyl)molybdopterin cytosine dinucleotide, identifying molybdopterin cytosine dinucleotide as the organic portion of the B. japonicum CODH molybdenum cofactor. The absorption spectrum of the purified enzyme was characteristic of a molybdenum-containing iron-sulfur flavoprotein. PMID:10788353

  15. Volcanic iodine monoxide observed from satellite

    NASA Astrophysics Data System (ADS)

    Schönhardt, Anja; Richter, Andreas; Theys, Nicolas; Burrows, John P.

    2016-04-01

    Halogen species are injected into the atmosphere by volcanic eruptions. Previous studies have reported observations of chlorine and bromine oxides in volcanic plumes. These emissions have a significant impact on the chemistry within the plume as well as on upper troposphere and lower stratosphere composition, e.g. through ozone depletion. Volcanic halogen oxides have been observed from different platforms, from ground, aircraft and from satellite. The present study reports on satellite observations of iodine monoxide, IO, following the eruption of the Kasatochi volcano, Alaska, in August 2008. Satellite measurements from the SCIAMACHY sensor onboard ENVISAT are used. In addition, the volcanic IO plume is also retrieved from GOME-2 / MetOP-A measurements. Largest IO column amounts reach up to more than 4×1013 molec/cm2, the results from both instruments being consistent. The IO plume has a very similar shape as the BrO plume and is observed for several days following the eruption. The present observations are the first evidence that besides chlorine and bromine oxides also iodine oxides can be emitted by volcanic eruptions. This has important implications for atmospheric composition and background iodine levels. Together with the simultaneous observations of BrO and SO2, iodine monoxide columns can possibly provide insights into the composition of the magma.

  16. Boron monoxide-hydrogen peroxide fuel cell

    SciTech Connect

    Struthers, R.C.

    1985-01-08

    A primary fuel cell including an elongate case defining a central ion exchange compartment with opposite ends and containing a liquid ionolyte. The case next defines an anode section at one end of the case and including a gas compartment containing boron monoxide gas fuel, a liquid compartment between the gas compartment and the ion exchange compartment and containing a liquid anolyte. The ionolyte and anolyte are separated by a cationic membrane. The gas and liquid compartments are separated by an anode plate including an electron collector part, a catalyst material carried by said part and a gas permeable hydrophobic membrane between the boron monoxide gas and the catalyst material. The cell further includes a cathode section at the other end of the case defining a cathode fuel compartment containing a fluid cathode fuel and a cathode plate between and separating the cathode fuel and the ionolyte in the ion exchange compartment. The cathode plate includes an electron distributor part and a catalyst material carried by the distributor part. If the cathode fuel is a gas fuel, the cathode plate also includes a gas permeable hydrophobic membrane between the catalyst material carried by the distributor part and the cathode fuel. The cathode and anode plates have terminals connected with a related external electric circuit.

  17. Integrated Science Assessment (ISA) for Carbon Monoxide ...

    EPA Pesticide Factsheets

    EPA announced the availability of the final report, Integrated Science Assessment (ISA) for Carbon Monoxide (CO). This report is EPA’s latest evaluation of the scientific literature on the potential human health and welfare effects associated with ambient exposures to CO. The development of this document is part of the Agency's periodic review of the national ambient air quality standards (NAAQS) for CO. The recently completed CO ISA and supplementary annexes, in conjunction with additional technical and policy assessments developed by EPA’s Office of Air and Radiation, will provide the scientific basis to inform EPA decisions related to the review of the current CO NAAQS. The integrated Plan for Review of the National Ambient Air Quality Standards for Carbon Monoxide (U.S. EPA, 2008, 193995) identifies key policy-relevant questions that provide a framework for this assessment of the scientific evidence. These questions frame the entire review of the NAAQS for CO and thus are informed by both science and policy considerations. The ISA organizes, presents, and integrates the scientific evidence which is considered along with findings from risk analyses and policy considerations to help the U.S. Environmental Protection Agency (EPA) address these questions during the NAAQS review.

  18. Carbon monoxide dehydrogenase activity in Bradyrhizobium japonicum.

    PubMed

    Lorite, M J; Tachil, J; Sanjuán, J; Meyer, O; Bedmar, E J

    2000-05-01

    Bradyrhizobium japonicum strain 110spc4 was capable of chemolithoautotrophic growth with carbon monoxide (CO) as a sole energy and carbon source under aerobic conditions. The enzyme carbon monoxide dehydrogenase (CODH; EC 1.2.99.2) has been purified 21-fold, with a yield of 16% and a specific activity of 58 nmol of CO oxidized/min/mg of protein, by a procedure that involved differential ultracentrifugation, anion-exchange chromatography, hydrophobic interaction chromatography, and gel filtration. The purified enzyme gave a single protein and activity band on nondenaturing polyacrylamide gel electrophoresis and had a molecular mass of 230,000 Da. The 230-kDa enzyme was composed of large (L; 75-kDa), medium (M; 28.4-kDa), and small (S; 17.2-kDa) subunits occurring in heterohexameric (LMS)(2) subunit composition. The 75-kDa polypeptide exhibited immunological cross-reactivity with the large subunit of the CODH of Oligotropha carboxidovorans. The B. japonicum enzyme contained, per mole, 2.29 atoms of Mo, 7.96 atoms of Fe, 7.60 atoms of labile S, and 1.99 mol of flavin. Treatment of the enzyme with iodoacetamide yielded di(carboxamidomethyl)molybdopterin cytosine dinucleotide, identifying molybdopterin cytosine dinucleotide as the organic portion of the B. japonicum CODH molybdenum cofactor. The absorption spectrum of the purified enzyme was characteristic of a molybdenum-containing iron-sulfur flavoprotein.

  19. 40 CFR 52.1179 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... enforceable emission limitations for stationary sources, transportation control measures, or a vehicle... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) Approval—On March 18, 1999, the Michigan Department of Environmental Quality...

  20. 40 CFR 52.1179 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... enforceable emission limitations for stationary sources, transportation control measures, or a vehicle... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) Approval—On March 18, 1999, the Michigan Department of Environmental Quality...

  1. 40 CFR 52.1887 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) Part D—Approval—The following portions of the Ohio plan are approved: (1) The carbon... Administrative Code. (2) The transportation control plans for the following urban areas: Akron (ozone component...

  2. 40 CFR 52.1887 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Control strategy: Carbon monoxide. 52...: Carbon monoxide. (a) Part D—Approval—The following portions of the Ohio plan are approved: (1) The carbon... Administrative Code. (2) The transportation control plans for the following urban areas: Akron (ozone component...

  3. 40 CFR 52.2089 - Control strategy: carbon monoxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Control strategy: carbon monoxide. 52... strategy: carbon monoxide. (a) Approval—On September 22, 2008, the Rhode Island Department of Environmental Management submitted a request to establish a limited maintenance plan for the Providence Rhode Island...

  4. 40 CFR 52.729 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Control strategy: Carbon monoxide. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Illinois> § 52.729 Control strategy: Carbon..., Illinois be granted a carbon monoxide (CO) state implementation plan (SIP) revision with...

  5. 40 CFR 52.1179 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Control strategy: Carbon monoxide. 52.1179 Section 52.1179 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...: Carbon monoxide. (a) Approval—On March 18, 1999, the Michigan Department of Environmental...

  6. 40 CFR 52.729 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Control strategy: Carbon monoxide. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Illinois> § 52.729 Control strategy: Carbon..., Illinois be granted a carbon monoxide (CO) state implementation plan (SIP) revision with...

  7. 40 CFR 52.2089 - Control strategy: carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: carbon monoxide. 52... strategy: carbon monoxide. (a) Approval—On September 22, 2008, the Rhode Island Department of Environmental Management submitted a request to establish a limited maintenance plan for the Providence Rhode Island...

  8. 40 CFR 52.1340 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Control strategy: Carbon monoxide. 52.1340 Section 52.1340 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...: Carbon monoxide. Approval—A maintenance plan and redesignation request for the St. Louis, Missouri,...

  9. 40 CFR 60.263 - Standard for carbon monoxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for carbon monoxide. 60.263... Production Facilities § 60.263 Standard for carbon monoxide. (a) On and after the date on which the... furnace any gases which contain, on a dry basis, 20 or greater volume percent of carbon...

  10. 40 CFR 52.1179 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Control strategy: Carbon monoxide. 52.1179 Section 52.1179 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...: Carbon monoxide. (a) Approval—On March 18, 1999, the Michigan Department of Environmental...

  11. 40 CFR 52.2089 - Control strategy: carbon monoxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 5 2012-07-01 2012-07-01 false Control strategy: carbon monoxide. 52... strategy: carbon monoxide. (a) Approval—On September 22, 2008, the Rhode Island Department of Environmental Management submitted a request to establish a limited maintenance plan for the Providence Rhode Island...

  12. 40 CFR 52.1340 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Control strategy: Carbon monoxide. 52.1340 Section 52.1340 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...: Carbon monoxide. Approval—A maintenance plan and redesignation request for the St. Louis, Missouri,...

  13. 40 CFR 52.729 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy: Carbon monoxide. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Illinois> § 52.729 Control strategy: Carbon..., Illinois be granted a carbon monoxide (CO) state implementation plan (SIP) revision with...

  14. 40 CFR 52.785 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Control strategy: Carbon monoxide. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Indiana § 52.785 Control strategy: Carbon... for attainment and maintenance of the national standards for carbon monoxide in the...

  15. 40 CFR 52.376 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Control strategy: Carbon monoxide. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Connecticut § 52.376 Control strategy: Carbon... submitted a revision to the carbon monoxide State Implementation Plan for the 1990 base year...

  16. 40 CFR 52.1340 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Control strategy: Carbon monoxide. 52.1340 Section 52.1340 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...: Carbon monoxide. Approval—A maintenance plan and redesignation request for the St. Louis, Missouri,...

  17. 40 CFR 52.1340 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Control strategy: Carbon monoxide. 52.1340 Section 52.1340 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...: Carbon monoxide. Approval—A maintenance plan and redesignation request for the St. Louis, Missouri,...

  18. 40 CFR 52.2089 - Control strategy: carbon monoxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 5 2013-07-01 2013-07-01 false Control strategy: carbon monoxide. 52... strategy: carbon monoxide. (a) Approval—On September 22, 2008, the Rhode Island Department of Environmental Management submitted a request to establish a limited maintenance plan for the Providence Rhode Island...

  19. 40 CFR 52.2089 - Control strategy: carbon monoxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 5 2014-07-01 2014-07-01 false Control strategy: carbon monoxide. 52... strategy: carbon monoxide. (a) Approval—On September 22, 2008, the Rhode Island Department of Environmental Management submitted a request to establish a limited maintenance plan for the Providence Rhode Island...

  20. 40 CFR 52.376 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Control strategy: Carbon monoxide. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Connecticut § 52.376 Control strategy: Carbon... submitted a revision to the carbon monoxide State Implementation Plan for the 1990 base year...

  1. 40 CFR 52.1179 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Control strategy: Carbon monoxide. 52.1179 Section 52.1179 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...: Carbon monoxide. (a) Approval—On March 18, 1999, the Michigan Department of Environmental...

  2. 40 CFR 52.785 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Control strategy: Carbon monoxide. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Indiana § 52.785 Control strategy: Carbon... for attainment and maintenance of the national standards for carbon monoxide in the...

  3. 40 CFR 52.785 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy: Carbon monoxide. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Indiana § 52.785 Control strategy: Carbon... for attainment and maintenance of the national standards for carbon monoxide in the...

  4. 40 CFR 52.376 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Control strategy: Carbon monoxide. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Connecticut § 52.376 Control strategy: Carbon... submitted a revision to the carbon monoxide State Implementation Plan for the 1990 base year...

  5. 40 CFR 52.1340 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Control strategy: Carbon monoxide. 52.1340 Section 52.1340 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...: Carbon monoxide. Approval—A maintenance plan and redesignation request for the St. Louis, Missouri,...

  6. 40 CFR 52.785 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Control strategy: Carbon monoxide. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Indiana § 52.785 Control strategy: Carbon... for attainment and maintenance of the national standards for carbon monoxide in the...

  7. 40 CFR 52.785 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Control strategy: Carbon monoxide. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Indiana § 52.785 Control strategy: Carbon... for attainment and maintenance of the national standards for carbon monoxide in the...

  8. 40 CFR 60.263 - Standard for carbon monoxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for carbon monoxide. 60.263... Production Facilities § 60.263 Standard for carbon monoxide. (a) On and after the date on which the... furnace any gases which contain, on a dry basis, 20 or greater volume percent of carbon...

  9. 40 CFR 52.729 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Control strategy: Carbon monoxide. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Illinois> § 52.729 Control strategy: Carbon..., Illinois be granted a carbon monoxide (CO) state implementation plan (SIP) revision with...

  10. 40 CFR 52.729 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Control strategy: Carbon monoxide. 52... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Illinois> § 52.729 Control strategy: Carbon..., Illinois be granted a carbon monoxide (CO) state implementation plan (SIP) revision with...

  11. 40 CFR 60.263 - Standard for carbon monoxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for carbon monoxide. 60.263... Production Facilities § 60.263 Standard for carbon monoxide. (a) On and after the date on which the... furnace any gases which contain, on a dry basis, 20 or greater volume percent of carbon...

  12. Carbon monoxide metabolism by photosynthetic bacteria: Progress report

    SciTech Connect

    Ludden, P.W.; Roberts, G.P.

    1988-01-01

    The photosynthetic bacterium, Rhodospirillum rubrum, is capable of converting carbon monoxide to CO/sub 2/ and cellular material. Because carbon monoxide is a major industrial pollutant in this country and a product of the biological oxidation of CO is the product of H/sub 2/, a major industrial feedstock, this process has practical importance. The oxidation of carbon monoxide to CO/sub 2/ by microorganisms is a major component of the carbon monoxide cycle on earth. We have isolated the enzyme responsible for this process from Rhodospirillum rubrum. Carbon monoxide dehydrogenase is an iron - sulfur, nickel- and zinc-containing enzyme. The enzyme is quite stable to heat and amendable to purification, however, it is very labile to oxygen, and all experiments must be conducted anaerobically. We are studying the activities of this enzyme, its regulation and its induction by its substrate carbon monoxide. The enzyme is absent in cells that have not been exposed to carbon monoxide, but cells produce the enzyme at a maximal rate upon exposure to carbon monoxide for as little as ten minutes. Oxygen, a potent and irreversible inhibitor of the enzyme, represses the synthesis of this enzyme. 1 tab.

  13. Real World of Industrial Chemistry: Organic Chemicals from Carbon Monoxide.

    ERIC Educational Resources Information Center

    Kolb, Kenneth E.; Kolb, Doris

    1983-01-01

    Carbon Monoxide obtained from coal may serve as the source for a wide variety of organic compounds. Several of these compounds are discussed, including phosgene, benzaldehyde, methanol, formic acid and its derivatives, oxo aldehydes, acrylic acids, and others. Commercial reactions of carbon monoxide are highlighted in a table. (JN)

  14. Real World of Industrial Chemistry: Organic Chemicals from Carbon Monoxide.

    ERIC Educational Resources Information Center

    Kolb, Kenneth E.; Kolb, Doris

    1983-01-01

    Carbon Monoxide obtained from coal may serve as the source for a wide variety of organic compounds. Several of these compounds are discussed, including phosgene, benzaldehyde, methanol, formic acid and its derivatives, oxo aldehydes, acrylic acids, and others. Commercial reactions of carbon monoxide are highlighted in a table. (JN)

  15. Carbon monoxide oxidation rates computed for automobile thermal reactor conditions

    NASA Technical Reports Server (NTRS)

    Brokaw, R. S.; Bittker, D. A.

    1972-01-01

    Carbon monoxide oxidation rates in thermal reactors for exhaust manifolds are computed by integrating differential equations for system of twenty-nine reversible chemical reactions. Reactors are noncatalytic replacements for conventional exhaust manifolds and are a system for reducing carbon monoxide and hydrocarbons in automobile exhausts.

  16. Fatal carbon monoxide intoxication after acetylene gas welding of pipes.

    PubMed

    Antonsson, Ann-Beth; Christensson, Bengt; Berge, Johan; Sjögren, Bengt

    2013-06-01

    Acetylene gas welding of district heating pipes can result in exposure to high concentrations of carbon monoxide. A fatal case due to intoxication is described. Measurements of carbon monoxide revealed high levels when gas welding a pipe with closed ends. This fatality and these measurements highlight a new hazard, which must be promptly prevented.

  17. Study on the deterioration mechanism of layered rock-salt electrodes using epitaxial thin films - Li(Ni, Co, Mn)O2 and their Zr-O surface modified electrodes

    NASA Astrophysics Data System (ADS)

    Abe, Machiko; Iba, Hideaki; Suzuki, Kota; Minamishima, Hiroaki; Hirayama, Masaaki; Tamura, Kazuhisa; Mizuki, Jun'ichiro; Saito, Tomohiro; Ikuhara, Yuichi; Kanno, Ryoji

    2017-03-01

    Deterioration mechanism of Li(Ni, Co, Mn)O2 and Zr-O surface modified electrodes has been elucidated using epitaxial thin films synthesized by pulsed laser deposition. The electrodes comprise a mixture of layered rock-salt and spinel phases. The deterioration mechanism is analyzed using cyclic voltammetry, in situ X-ray diffraction measurements, and in situ neutron reflectometry. The spinel phase in the electrodes has low electrochemical activity and is not involved in Li insertion/extraction. The amount of Li participating in the charge-discharge reactions in the layered rock-salt phase increases with cycling, inducing a phase change at the electrode surface, lowering the reversibility. In contrast, in the Zr-O surface modified electrode, the spinel phase does not increase on charging/discharging. Thus, the Zr-O modification stabilizes the surface of layered rock-salt structure, thereby improving the cycling characteristics. Also, after the Zr-O modification, the Li concentration in the liquid electrolyte near the electrode/electrolyte interface increases during charging/discharging. The Zr-O surface modification not only stabilizes the electrode surface but also causes changes on the electrolyte side. Using the mixed model electrodes, we elucidate the mechanism of electrode deterioration and the origin of the improvement in cycling characteristics occurring on surface modification.

  18. Dispersion strengthened copper

    DOEpatents

    Sheinberg, H.; Meek, T.T.; Blake, R.D.

    1990-01-09

    A composition of matter is described which is comprised of copper and particles which are dispersed throughout the copper, where the particles are comprised of copper oxide and copper having a coating of copper oxide. A method for making this composition of matter is also described. This invention relates to the art of powder metallurgy and, more particularly, it relates to dispersion strengthened metals.

  19. Unintentional carbon monoxide poisoning in Colorado, 1986 through 1991.

    PubMed Central

    Cook, M; Simon, P A; Hoffman, R E

    1995-01-01

    Unintentional carbon monoxide poisonings were identified through death certificates, by hyperbaric chambers, and by laboratories required to report carboxyhemoglobin levels greater than 12%. From 1986 to 1991, 981 cases were reported, including 174 deaths. Deaths most often resulted from fire-related carbon monoxide intoxication (36.2%), followed by motor vehicle exhaust (34.5%), and furnaces (10.3%). Among nonfatal cases, furnaces were the leading source of carbon monoxide exposure (44.3%), followed by motor vehicle exhaust (22.8%). The importance of furnaces and other home heating devices in carbon monoxide intoxication may be underappreciated if only mortality data are examined. Surveillance of carbon monoxide-related morbidity is a useful adjunct to mortality surveillance in guiding prevention efforts. PMID:7604927

  20. Search of medical literature for indoor carbon monoxide exposure

    SciTech Connect

    Brennan, T.; Ivanovich, M.

    1995-12-01

    This report documents a literature search on carbon monoxide. The search was limited to the medical and toxicological databases at the National Library of Medicine (MEDLARS). The databases searched were Medline, Toxline and TOXNET. Searches were performed using a variety of strategies. Combinations of the following keywords were used: carbon, monoxide, accidental, residential, occult, diagnosis, misdiagnosis, heating, furnace, and indoor. The literature was searched from 1966 to the present. Over 1000 references were identified and summarized using the following abbreviations: The major findings of the search are: (1) Acute and subacute carbon monoxide exposures result in a large number of symptoms affecting the brain, kidneys, respiratory system, retina, and motor functions. (2) Acute and subacute carbon monoxide (CO) poisonings have been misdiagnosed on many occasions. (3) Very few systematic investigations have been made into the frequency and consequences of carbon monoxide poisonings.

  1. Atomic-scale disproportionation in amorphous silicon monoxide

    PubMed Central

    Hirata, Akihiko; Kohara, Shinji; Asada, Toshihiro; Arao, Masazumi; Yogi, Chihiro; Imai, Hideto; Tan, Yongwen; Fujita, Takeshi; Chen, Mingwei

    2016-01-01

    Solid silicon monoxide is an amorphous material which has been commercialized for many functional applications. However, the amorphous structure of silicon monoxide is a long-standing question because of the uncommon valence state of silicon in the oxide. It has been deduced that amorphous silicon monoxide undergoes an unusual disproportionation by forming silicon- and silicon-dioxide-like regions. Nevertheless, the direct experimental observation is still missing. Here we report the amorphous structure characterized by angstrom-beam electron diffraction, supplemented by synchrotron X-ray scattering and computer simulations. In addition to the theoretically predicted amorphous silicon and silicon-dioxide clusters, suboxide-type tetrahedral coordinates are detected by angstrom-beam electron diffraction at silicon/silicon-dioxide interfaces, which provides compelling experimental evidence on the atomic-scale disproportionation of amorphous silicon monoxide. Eventually we develop a heterostructure model of the disproportionated silicon monoxide which well explains the distinctive structure and properties of the amorphous material. PMID:27172815

  2. Atomic-scale disproportionation in amorphous silicon monoxide.

    PubMed

    Hirata, Akihiko; Kohara, Shinji; Asada, Toshihiro; Arao, Masazumi; Yogi, Chihiro; Imai, Hideto; Tan, Yongwen; Fujita, Takeshi; Chen, Mingwei

    2016-05-13

    Solid silicon monoxide is an amorphous material which has been commercialized for many functional applications. However, the amorphous structure of silicon monoxide is a long-standing question because of the uncommon valence state of silicon in the oxide. It has been deduced that amorphous silicon monoxide undergoes an unusual disproportionation by forming silicon- and silicon-dioxide-like regions. Nevertheless, the direct experimental observation is still missing. Here we report the amorphous structure characterized by angstrom-beam electron diffraction, supplemented by synchrotron X-ray scattering and computer simulations. In addition to the theoretically predicted amorphous silicon and silicon-dioxide clusters, suboxide-type tetrahedral coordinates are detected by angstrom-beam electron diffraction at silicon/silicon-dioxide interfaces, which provides compelling experimental evidence on the atomic-scale disproportionation of amorphous silicon monoxide. Eventually we develop a heterostructure model of the disproportionated silicon monoxide which well explains the distinctive structure and properties of the amorphous material.

  3. Copper peroxide

    NASA Technical Reports Server (NTRS)

    Moser, L.

    1988-01-01

    A number of oxidizing agents, including chlorine, bromine, ozone and other peroxides, were allowed to act on copper solutions with the intention of forming copper peroxide. The only successful agent appears to be hydrogen peroxide. It must be used in a neutral 50 to 30 percent solution at a temperature near zero. Other methods described in the literature apparently do not work. The excess of hydrogen must be quickly sucked out of the brown precipitate, which it is best to wash with alcohol and ether. The product, crystalline under a microscope, can be analyzed only approximately. It approaches the formula CuO2H2O. In alkaline solution it appears to act catalytically in causing the decomposition of other peroxides, so that Na2O2 cannot be used to prepare it. On the addition of acids the H2O2 is regenerated. The dry substance decomposes much more slowly than the moist but is not very stable.

  4. Copper metallothioneins.

    PubMed

    Calvo, Jenifer; Jung, Hunmin; Meloni, Gabriele

    2017-04-01

    Metallothioneins (MTs) are a class of low molecular weight and cysteine-rich metal binding proteins present in all the branches of the tree of life. MTs efficiently bind with high affinity several essential and toxic divalent and monovalent transition metals by forming characteristic polynuclear metal-thiolate clusters within their structure. MTs fulfil multiple biological functions related to their metal binding properties, with essential roles in both Zn(II) and Cu(I) homeostasis as well as metal detoxification. Depending on the organism considered, the primary sequence, and the specific physiological and metabolic status, Cu(I)-bound MT isoforms have been isolated, and their chemistry and biology characterized. Besides the recognized role in the biochemistry of divalent metals, it is becoming evident that unique biological functions in selectively controlling copper levels, its reactivity as well as copper-mediated biochemical processes have evolved in some members of the MT superfamily. Selected examples are reviewed to highlight the peculiar chemical properties and biological functions of copper MTs. © 2016 IUBMB Life, 69(4):236-245, 2017. © 2017 International Union of Biochemistry and Molecular Biology.

  5. Carbon monoxide exposure of subjects with documented cardiac arrhythmias

    SciTech Connect

    Chaitman, B.R.; Dahms, T.E.; Byers, S.; Carroll, L.W.; Younis, L.T.; Wiens, R.D. )

    1992-09-01

    The impact of low-level carbon monoxide exposure on ventricular arrhythmia frequency in patients with ischemic heart disease has not been thoroughly studied. The issue is of concern because of the potential proarrhythmic effect of carbon monoxide in patients with ischemic heart disease. We studied 30 subjects with well-documented coronary artery disease who had an average of at least 30 ventricular ectopic beats per hour over a 20-hour monitoring interval. By using appropriate inclusion and exclusion criteria, subjects were selected and enrolled in a randomized double-blind study to determine the effects of carbon monoxide exposure on ventricular arrhythmia frequency at rest, during exercise, and during ambulatory activities. The carbon monoxide exposure was designed to result in 3% or 5% carboxyhemoglobin levels, as measured by gas chromatography. The carbon monoxide exposure protocol produced target levels in 60 minutes, and the levels were maintained for an additional 90 minutes to provide adequate time to assess the impact of carbon monoxide on the frequency of ventricular ectopic beats. The data on total and repetitive ventricular arrhythmias were analyzed for seven specific time intervals: (1) two hours before carbon monoxide exposure; (2) during the two-hour carbon monoxide or air exposure; (3) during a two-hour rest period; (4) during an exercise period; (5) during an exercise recovery period; (6) six hours after carbon monoxide or air exposure; and (7) approximately 10 hours after exposure, or the remaining recording interval on the Holter monitor. There was no increase in ventricular arrhythmia frequency after carbon monoxide exposure, regardless of the level of carboxyhemoglobin or the type of activity.

  6. Element-resolved atomic structure imaging of rocksalt Ge{sub 2}Sb{sub 2}Te{sub 5} phase-change material

    SciTech Connect

    Zhang, Bin; Chen, Yongjin; Han, Xiaodong E-mail: ema@jhu.edu; Zhang, Wei E-mail: ema@jhu.edu; Shen, Zhenju; Li, Jixue; Zhang, Shengbai; Zhang, Ze; Wuttig, Matthias; Mazzarello, Riccardo; and others

    2016-05-09

    Disorder-induced electron localization and metal-insulator transitions (MITs) have been a very active research field starting from the seminal paper by Anderson half a century ago. However, pure Anderson insulators are very difficult to identify due to ubiquitous electron-correlation effects. Recently, an MIT has been observed in electrical transport measurements on the crystalline state of phase-change GeSbTe compounds, which appears to be exclusively disorder driven. Subsequent density functional theory simulations have identified vacancy disorder to localize electrons at the Fermi level. Here, we report a direct atomic scale chemical identification experiment on the rocksalt structure obtained upon crystallization of amorphous Ge{sub 2}Sb{sub 2}Te{sub 5}. Our results confirm the two-sublattice structure resolving the distribution of chemical species and demonstrate the existence of atomic disorder on the Ge/Sb/vacancy sublattice. Moreover, we identify a gradual vacancy ordering process upon further annealing. These findings not only provide a structural underpinning of the observed Anderson localization but also have implications for the development of novel multi-level data storage within the crystalline phases.

  7. Laser ablation synthesis of Si-overdoped Ni1- x O with rocksalt-type derived superstructures and tailored optical properties

    NASA Astrophysics Data System (ADS)

    Chang, Yu-Ling; Lin, Shih-Siang; Zheng, Yuyuan; Shen, Pouyan; Chen, Shuei-Yuan

    2017-04-01

    Si-overdoped Ni1- x O nanocondensates/particulates with novel superstructures were fabricated by pulsed laser ablation (PLA) of Ni in tetraethyl orthosilicate and characterized using electron microscopy and optical spectroscopy. The Si-overdoped and C-H-mediated Ni1- x O turned out to have two kinds of rocksalt-type derived superstructures, i.e., (1) 2 × 2 × 2 type of high-pressure stabilized Ni2SiO4 spinel which occurred as platy domains in the particles with {135} facets and (2) 3 × 3 × 3 type intimately mixed with 1D 6 × (100) throughout the particles with {100}, {110}, and {111} facets. Such shaped and superstructured particles, more or less encapsulated with graphitic carbon and siliceous amorphous phase, showed phase and dopant-tailored optical properties, in particular violet and green photoluminescence and UV-visible absorbance for potential engineering applications and shed light on their occurrence in natural dynamic settings.

  8. Structural, electronic and magnetic properties of the (001), (110) and (111) surfaces of rocksalt sodium sulfide: A first-principles study

    NASA Astrophysics Data System (ADS)

    Afshari, M.; Moradi, M.; Rostami, M.

    2015-01-01

    First principles study of the structural, electronic and magnetic properties of the (111), (110) and (001) surfaces of rocksalt sodium sulfide (rs-NaS) are reported. The results show that the bulk half-metallicity of this compound is well preserved on the surfaces considered here except for Na-terminated (111) surface. The spin-flip gap at the S-terminated (111), (001) and (110) surfaces are close to the bulk value. Using ab-initio atomistic thermodynamics, we calculate the surface energies as a function of chemical potential to find the most stable surface. We find that the Na-terminated (111) surface is the most stable one over the whole allowed range of chemical potential, while the surface energies of the (001) and (110) surfaces approach the most stable surface energy at the sulfur rich environment. We have also calculated the interlayer exchange interaction in bulk and Na-terminated (111) surface by classical Heisenberg model and we found that the surface effects do not change these kinds of interactions significantly.

  9. Rocksalt versus layered ordering in double perovskites: A case study with La2CuSnO6 and La2CuIrO6

    NASA Astrophysics Data System (ADS)

    Samanta, Kartik; Saha-Dasgupta, Tanusri

    2017-06-01

    The nature of ordering of B and B ' transition metal ions in double perovskite compounds of general composition A2BB 'O6 is an important topic, since the physical properties crucially depend on it. In the present study, considering the specific cases of La2CuSnO6 and La2CuIrO6 , we carry out first-principles calculations with an aim to obtain microscopic understanding on this issue. Our study reveals the presence of Jahn-Teller distorted B ion, like Cu2 + helps in band energy stabilization of the layered ordering over the rocksalt ordering. However, introduction of magnetism may reverse this trend, especially in the presence of a second magnetic ion at B ' site, which may introduce a strong superexchange path involving B-O-B ' , as found in the case of La2CuIrO6 . We further find the spin-orbit coupling at Ir site drives the La2CuIrO6 compound to be a spin-orbit assisted Mott insulator.

  10. [Students knowledge on carbon monoxide toxicity].

    PubMed

    Pach, Janusz; Ogonowska, Dorota; Targosz, Dorota; Dziuban, Agata; Brzyski, Piotr; Pach, Dorota

    2010-01-01

    The results of questionnaire research on carbon monoxide (CO) poisoning in students of State Higher Vocational School in Nowy Sacz (Institutes of Economy, Pedagogic, Technical and Health) are presented in the study. The mean age of the group examined, with a female predomination (77.6%) was 22.7 +/- 4.94 years. The questionnaire covered demographic data and knowledge on CO source, exposure, most frequent and most severe symptoms, most severe sequels, risky behavior and risk groups in CO poisoning. The results obtained indicate on inadequate knowledge on CO poisoning even in young students population. The proper education and prophylaxis activity is necessary to avoid accidental CO poisoning, especially that they also occur in spring-summer season.

  11. Integrated Science Assessment (ISA) for Carbon Monoxide ...

    EPA Pesticide Factsheets

    EPA announced that the First External Review Draft of the Integrated Science Assessment (ISA) for Carbon Monoxide (CO) and related Annexes was made available for independent peer review and public review. This draft ISA document represents a concise synthesis and evaluation of the most policy-relevant science and will ultimately provide the scientific bases for EPA's decision regarding whether the current standards for CO sufficiently protect public health and the environment. The Integrated Plan for Review of the NAAQS for CO {U.S. EPA, 2008 #8615} identifies key policy-relevant questions that provide a framework for this review of the scientific evidence. These questions frame the entire review of the NAAQS, and thus are informed by both science and policy considerations. The ISA organizes and presents the scientific evidence such that it, when considered along with findings from risk analyses and policy considerations, will help the EPA address these questions during the NAAQS review:

  12. Analysis of GASP carbon monoxide data

    NASA Technical Reports Server (NTRS)

    Wu, M. F.

    1981-01-01

    Atmospheric carbon monoxide in the upper troposphere and lower stratosphere for the period March 1977 through October 1978 was analyzed. The CO data are summarized and the distribution and variations in space and time of this gas are presented. The data show that the CO mixing ratios are higher in the troposphere than those in the stratosphere. In the Northern Hemisphere the highest value of CO mixing ratio occurs in spring, although more data are needed to verify these findings. Correlation coefficients among CO, O3, air temperature (T) and winds were calculated for different regions under different seasons. It was found that the CO correlates negatively with O3 above 20 degrees latitude and positively below that latitude. Case studies using the data of CO, O3, and T measured simultaneously were performed. Discussions and suggestions are made. Ozone data on seasonal basis is also summarized.

  13. Reduction of Carbon Monoxide. Past Research Summary

    DOE R&D Accomplishments Database

    Schrock, R. R.

    1982-01-01

    Research programs for the year on the preparation, characterization, and reactions of binuclear tantalum complexes are described. All evidence to date suggest the following of these dimeric molecules: (1) the dimer does not break into monomers under mild conditions; (2) intermolecular hydride exchange is not negligible, but it is slow; (3) intermolecular non-ionic halide exchange is fast; (4) the ends of the dimers can rotate partially with respect to one another. The binuclear tantalum hydride complexes were found to react with carbon monoxide to give a molecule which is the only example of reduction of CO by a transition metal hydride to give a complex containing a CHO ligand. Isonitrides also reacted in a similar manner with dimeric tantalum hydride. (ATT)

  14. Carbon monoxide in the treatment of sepsis.

    PubMed

    Nakahira, Kiichi; Choi, Augustine M K

    2015-12-15

    Carbon monoxide (CO), a low-molecular-weight gas, is endogenously produced in the body as a product of heme degradation catalyzed by heme oxygenase (HO) enzymes. As the beneficial roles of HO system have been elucidated in vitro and in vivo, CO itself has also been reported as a potent cytoprotective molecule. Whereas CO represents a toxic inhalation hazard at high concentration, low-dose exogenous CO treatment (~250-500 parts per million) demonstrates protective functions including but not limited to the anti-inflammatory and antiapoptotic effects in preclinical models of human diseases. Of note, CO exposure confers protection in animal models of sepsis by inhibiting inflammatory responses and also enhancing bacterial phagocytosis in leukocytes. These unique functions of CO including both dampening inflammation and promoting host defense mechanism are mediated by multiple pathways such as autophagy induction or biosynthesis of specialized proresolving lipid mediators. We suggest that CO gas may represent a novel therapy for patients with sepsis.

  15. Mass spectrometry provides warning of carbon monoxide exposure via trifluoromethane.

    PubMed

    Woehick, H J; Dunning, M; Nithipatikom, K; Kulier, A H; Henry, D W

    1996-06-01

    The chemical breakdown of isoflurane, enflurane, or desflurane in dried carbon dioxide absorbents may produce carbon monoxide. Some mass spectrometers can give false indications of enflurane during anesthetic breakdown. During clinical anesthesia with isoflurane or desflurane, the presence of carbon monoxide in respiratory gas was confirmed when enflurane was inappropriately indicated by a clinical mass spectrometer that identified enflurane at mass to charge ratio = 69. In vitro, isoflurane, enflurane, or desflurane in oxygen was passed through dried carbon dioxide absorbents at 35, 45, and 55 degrees C. Gases were analyzed by gas chromatography and by mass spectrometry. Mass spectrometry identified several clinical incidents in which 30-410 ppm carbon monoxide was measured in respiratory gas. Trifluoromethane was produced during in vitro breakdown of isoflurane or desflurane. Although these inappropriately indicated quantities of "enflurane" correlated (r2 > 0.95) to carbon monoxide concentrations under a variety of conditions, this ratio varied with temperature, anesthetic agent, absorbent type, and water content. Trifluoromethane causes the inappropriate indication of enflurane by mass spectrometry, and indicates isoflurane and desflurane breakdown. Because the ratio of carbon monoxide to trifluoromethane varies with conditions, this technique cannot be used to quantitatively determine the amount of carbon monoxide to which a patient is exposed. If any warning of anesthetic breakdown results from this technique then remedial steps should be taken immediately to stop patient exposure to carbon monoxide. No warning can be provided for the breakdown of enflurane by this technique.

  16. Carbon monoxide sensor and method of use thereof

    DOEpatents

    McDaniel; Anthony H. , Medlin; J. Will , Bastasz; Robert J.

    2007-09-04

    Carbon monoxide sensors suitable for use in hydrogen feed streams and methods of use thereof are disclosed. The sensors are palladium metal/insulator/semiconductor (Pd-MIS) sensors which may possess a gate metal layer having uniform, Type 1, or non-uniform, Type 2, film morphology. Type 1 sensors display an increased sensor response in the presence of carbon monoxide while Type 2 sensors display a decreased response to carbon monoxide. The methods and sensors disclosed herein are particularly suitable for use in proton exchange membrane fuel cells (PEMFCs).

  17. Mars in situ propellants: Carbon monoxide and oxygen ignition experiments

    NASA Technical Reports Server (NTRS)

    Linne, Diane L.; Roncace, James; Groth, Mary F.

    1990-01-01

    Carbon monoxide and oxygen were tested in a standard spark-torch igniter to identify the ignition characteristics of this potential Mars in situ propellant combination. The ignition profiles were determined as functions of mixture ratio, amount of hydrogen added to the carbon monoxide, and oxygen inlet temperature. The experiments indicated that the carbon monoxide and oxygen combination must have small amounts of hydrogen present to initiate reaction. Once the reaction was started, the combustion continued without the presence of hydrogen. A mixture ratio range was identified where ignition occurred, and this range varied with the oxygen inlet temperature.

  18. Copper allergy from dental copper amalgam?

    PubMed

    Gerhardsson, Lars; Björkner, Bert; Karlsteen, Magnus; Schütz, Andrejs

    2002-05-06

    A 65-year-old female was investigated due to a gradually increasing greenish colour change of her plastic dental splint, which she used to prevent teeth grinding when sleeping. Furthermore, she had noted a greenish/bluish colour change on the back of her black gloves, which she used to wipe her tears away while walking outdoors. The investigation revealed that the patient had a contact allergy to copper, which is very rare. She had, however, had no occupational exposure to copper. The contact allergy may be caused by long-term exposure of the oral mucosa to copper from copper-rich amalgam fillings, which were frequently used in childhood dentistry up to the 1960s in Sweden. The deposition of a copper-containing coating on the dental splint may be caused by a raised copper intake from drinking water, increasing the copper excretion in saliva, in combination with release of copper due to electrochemical corrosion of dental amalgam. The greenish colour change of the surface of the splint is probably caused by deposition of a mixture of copper compounds, e.g. copper carbonates. Analysis by the X-ray diffraction technique indicates that the dominant component is copper oxide (Cu2O and CuO). The corresponding greenish/bluish discoloration observed on the back of the patient's gloves may be caused by increased copper excretion in tears.

  19. 49 CFR 392.66 - Carbon monoxide; use of commercial motor vehicle when detected.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 5 2011-10-01 2011-10-01 false Carbon monoxide; use of commercial motor vehicle... SAFETY REGULATIONS DRIVING OF COMMERCIAL MOTOR VEHICLES Prohibited Practices § 392.66 Carbon monoxide... monoxide; (2) Where carbon monoxide has been detected in the interior of the commercial motor vehicle; (3...

  20. 40 CFR 52.243 - Interim approval of the Carbon Monoxide plan for the South Coast.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Interim approval of the Carbon Monoxide... § 52.243 Interim approval of the Carbon Monoxide plan for the South Coast. The Carbon Monoxide plan for... such earlier date the State has submitted as a SIP revision a demonstration that the carbon monoxide...

  1. 40 CFR 52.243 - Interim approval of the Carbon Monoxide plan for the South Coast.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Interim approval of the Carbon Monoxide... § 52.243 Interim approval of the Carbon Monoxide plan for the South Coast. The Carbon Monoxide plan for... such earlier date the State has submitted as a SIP revision a demonstration that the carbon monoxide...

  2. 49 CFR 392.66 - Carbon monoxide; use of commercial motor vehicle when detected.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Carbon monoxide; use of commercial motor vehicle... SAFETY REGULATIONS DRIVING OF COMMERCIAL MOTOR VEHICLES Prohibited Practices § 392.66 Carbon monoxide... monoxide; (2) Where carbon monoxide has been detected in the interior of the commercial motor vehicle; (3...

  3. COPPER CORROSION RESEARCH UPDATE

    EPA Science Inventory

    Copper release and corrosion related issues continue to be important to many water systems. The objective of this presentation is to discuss the current state of copper research at the USEPA. Specifically, the role of aging on copper release, use of phosphates for copper corrosio...

  4. Carbon monoxide poisoning in the United Arab Emirates.

    PubMed

    Al Kaabi, Juma M; Wheatley, Andrew D; Barss, Peter; Al Shamsi, Mariam; Lababidi, Anis; Mushtaq, Ahmed

    2011-01-01

    Carbon monoxide (CO) poisoning is rare in the Arabian Peninsula and occurs almost exclusively during the winter months. Knowledge and perception of the hazards of carbon monoxide is limited. Migrant workers from warm climates appear particularly at risk. We investigated 46 cases of carbon monoxide poisoning presenting at emergency departments from 2007-2009 of the two main hospitals in Al Ain city, United Arab Emirates. Interviews, hospital records, and administered questionnaires were used to collect the data. Among the 46 cases investigated, 24 (52%) were males. Foreign nationals compromised 80% of the cases and the incidence was 3.1 cases per 100,000 residents per year. Burning charcoal in poorly ventilated residences was the predominant source of the carbon monoxide poisoning. Almost all cases (98%) were admitted during the winter months, most in the early morning hours. Carboxyhaemoglobin (COHb) was significantly increased in cases with loss of consciousness and depressed consciousness. There were no reported fatalities.

  5. Concentration and Transport of Carbon Monoxide from the California Wildfires

    NASA Image and Video Library

    2009-09-04

    Carbon monoxide in the smoke from the Station fire was lofted high into the atmosphere, where it was observed by JPL Atmospheric Infrared Sounder instrument onboard NASA Aqua satellite. Animation available at the Photojournal.

  6. Measuring Carbon Monoxide in Auto Exhaust by Gas Chromatography.

    ERIC Educational Resources Information Center

    Jaffe, Dan; Herndon, Scott

    1995-01-01

    Presents a simple and reliable technique using commonly available equipment for monitoring carbon monoxide in automobile exhaust. The experiment utilizes a gas chromatograph and a thermal conductivity detector (TCD). (DDR)

  7. Atmospheric analyzer, carbon monoxide monitor and toluene diisocyanate monitor

    NASA Technical Reports Server (NTRS)

    Shannon, A. V.

    1977-01-01

    The purpose of the atmospheric analyzer and the carbon monoxide and toluene diisocyanate monitors is to analyze the atmospheric volatiles and to monitor carbon monoxide and toluene diisocyanate levels in the cabin atmosphere of Skylab. The carbon monoxide monitor was used on Skylab 2, 3, and 4 to detect any carbon monoxide levels above 25 ppm. Air samples were taken once each week. The toluene diisocyanate monitor was used only on Skylab 2. The loss of a micrometeoroid shield following the launch of Skylab 1 resulted in overheating of the interior walls of the Orbital Workshop. A potential hazard existed from outgassing of an isocyanate derivative resulting from heat-decomposition of the rigid polyurethane wall insulation. The toluene diisocyanate monitor was used to detect any polymer decomposition. The atmospheric analyzer was used on Skylab 4 because of a suspected leak in the Skylab cabin. An air sample was taken at the beginning, middle, and the end of the mission.

  8. Measuring Carbon Monoxide in Auto Exhaust by Gas Chromatography.

    ERIC Educational Resources Information Center

    Jaffe, Dan; Herndon, Scott

    1995-01-01

    Presents a simple and reliable technique using commonly available equipment for monitoring carbon monoxide in automobile exhaust. The experiment utilizes a gas chromatograph and a thermal conductivity detector (TCD). (DDR)

  9. 40 CFR 60.263 - Standard for carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... provisions of this subpart shall cause to be discharged in to the atmosphere from any electric submerged arc furnace any gases which contain, on a dry basis, 20 or greater volume percent of carbon monoxide...

  10. 40 CFR 60.263 - Standard for carbon monoxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... provisions of this subpart shall cause to be discharged in to the atmosphere from any electric submerged arc furnace any gases which contain, on a dry basis, 20 or greater volume percent of carbon monoxide...

  11. An interesting cause of pulmonary emboli: Acute carbon monoxide poisoning

    SciTech Connect

    Sevinc, A.; Savli, H.; Atmaca, H.

    2005-07-01

    Carbon monoxide poisoning, a public health problem of considerable significance, is a relatively frequent event today, resulting in thousands of hospitalizations annually. A 70-year-old lady was seen in the emergency department with a provisional diagnosis of carbon monoxide poisoning. The previous night, she slept in a tightly closed room heated with coal ember. She was found unconscious in the morning with poor ventilation. She had a rare presentation of popliteal vein thrombosis, pulmonary emboli, and possible tissue necrosis with carbon monoxide poisoning. Oxygen treatment with low-molecular-weight heparin (nadroparine) and warfarin therapy resulted in an improvement in both popliteal and pulmonary circulations. In conclusion, the presence of pulmonary emboli should be sought in patients with carbon monoxide poisoning.

  12. High-capacity electrode materials for rechargeable lithium batteries: Li3NbO4-based system with cation-disordered rocksalt structure

    PubMed Central

    Yabuuchi, Naoaki; Takeuchi, Mitsue; Nakayama, Masanobu; Shiiba, Hiromasa; Ogawa, Masahiro; Nakayama, Keisuke; Ohta, Toshiaki; Endo, Daisuke; Ozaki, Tetsuya; Inamasu, Tokuo; Sato, Kei; Komaba, Shinichi

    2015-01-01

    Rechargeable lithium batteries have rapidly risen to prominence as fundamental devices for green and sustainable energy development. Lithium batteries are now used as power sources for electric vehicles. However, materials innovations are still needed to satisfy the growing demand for increasing energy density of lithium batteries. In the past decade, lithium-excess compounds, Li2MeO3 (Me = Mn4+, Ru4+, etc.), have been extensively studied as high-capacity positive electrode materials. Although the origin as the high reversible capacity has been a debatable subject for a long time, recently it has been confirmed that charge compensation is partly achieved by solid-state redox of nonmetal anions (i.e., oxide ions), coupled with solid-state redox of transition metals, which is the basic theory used for classic lithium insertion materials, such as LiMeO2 (Me = Co3+, Ni3+, etc.). Herein, as a compound with further excess lithium contents, a cation-ordered rocksalt phase with lithium and pentavalent niobium ions, Li3NbO4, is first examined as the host structure of a new series of high-capacity positive electrode materials for rechargeable lithium batteries. Approximately 300 mAh⋅g−1 of high-reversible capacity at 50 °C is experimentally observed, which partly originates from charge compensation by solid-state redox of oxide ions. It is proposed that such a charge compensation process by oxide ions is effectively stabilized by the presence of electrochemically inactive niobium ions. These results will contribute to the development of a new class of high-capacity electrode materials, potentially with further lithium enrichment (and fewer transition metals) in the close-packed framework structure with oxide ions. PMID:26056288

  13. High-capacity electrode materials for rechargeable lithium batteries: Li3NbO4-based system with cation-disordered rocksalt structure.

    PubMed

    Yabuuchi, Naoaki; Takeuchi, Mitsue; Nakayama, Masanobu; Shiiba, Hiromasa; Ogawa, Masahiro; Nakayama, Keisuke; Ohta, Toshiaki; Endo, Daisuke; Ozaki, Tetsuya; Inamasu, Tokuo; Sato, Kei; Komaba, Shinichi

    2015-06-23

    Rechargeable lithium batteries have rapidly risen to prominence as fundamental devices for green and sustainable energy development. Lithium batteries are now used as power sources for electric vehicles. However, materials innovations are still needed to satisfy the growing demand for increasing energy density of lithium batteries. In the past decade, lithium-excess compounds, Li2MeO3 (Me = Mn(4+), Ru(4+), etc.), have been extensively studied as high-capacity positive electrode materials. Although the origin as the high reversible capacity has been a debatable subject for a long time, recently it has been confirmed that charge compensation is partly achieved by solid-state redox of nonmetal anions (i.e., oxide ions), coupled with solid-state redox of transition metals, which is the basic theory used for classic lithium insertion materials, such as LiMeO2 (Me = Co(3+), Ni(3+), etc.). Herein, as a compound with further excess lithium contents, a cation-ordered rocksalt phase with lithium and pentavalent niobium ions, Li3NbO4, is first examined as the host structure of a new series of high-capacity positive electrode materials for rechargeable lithium batteries. Approximately 300 mAh ⋅ g(-1) of high-reversible capacity at 50 °C is experimentally observed, which partly originates from charge compensation by solid-state redox of oxide ions. It is proposed that such a charge compensation process by oxide ions is effectively stabilized by the presence of electrochemically inactive niobium ions. These results will contribute to the development of a new class of high-capacity electrode materials, potentially with further lithium enrichment (and fewer transition metals) in the close-packed framework structure with oxide ions.

  14. Copper and Copper Proteins in Parkinson's Disease

    PubMed Central

    Rivera-Mancia, Susana; Diaz-Ruiz, Araceli; Tristan-Lopez, Luis; Rios, Camilo

    2014-01-01

    Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson's disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson's disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased protein-bound copper in brain may enhance iron accumulation and the associated oxidative stress. The function of other copper-binding proteins such as Cu/Zn-SOD and metallothioneins is also beneficial to prevent neurodegeneration. Copper may regulate neurotransmission since it is released after neuronal stimulus and the metal is able to modulate the function of NMDA and GABA A receptors. Some of the proteins involved in copper transport are the transporters CTR1, ATP7A, and ATP7B and the chaperone ATOX1. There is limited information about the role of those biomolecules in the pathophysiology of Parkinson's disease; for instance, it is known that CTR1 is decreased in substantia nigra pars compacta in Parkinson's disease and that a mutation in ATP7B could be associated with Parkinson's disease. Regarding copper-related therapies, copper supplementation can represent a plausible alternative, while copper chelation may even aggravate the pathology. PMID:24672633

  15. Copper and copper proteins in Parkinson's disease.

    PubMed

    Montes, Sergio; Rivera-Mancia, Susana; Diaz-Ruiz, Araceli; Tristan-Lopez, Luis; Rios, Camilo

    2014-01-01

    Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson's disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson's disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased protein-bound copper in brain may enhance iron accumulation and the associated oxidative stress. The function of other copper-binding proteins such as Cu/Zn-SOD and metallothioneins is also beneficial to prevent neurodegeneration. Copper may regulate neurotransmission since it is released after neuronal stimulus and the metal is able to modulate the function of NMDA and GABA A receptors. Some of the proteins involved in copper transport are the transporters CTR1, ATP7A, and ATP7B and the chaperone ATOX1. There is limited information about the role of those biomolecules in the pathophysiology of Parkinson's disease; for instance, it is known that CTR1 is decreased in substantia nigra pars compacta in Parkinson's disease and that a mutation in ATP7B could be associated with Parkinson's disease. Regarding copper-related therapies, copper supplementation can represent a plausible alternative, while copper chelation may even aggravate the pathology.

  16. Arizona Copper

    NASA Image and Video Library

    2017-09-27

    Arizona produces 60% of the total copper mined in the US; in 2007, 750,000 tons of copper came out of the state. One of the major mining districts is located about 30 km south of Tucson. Starting around 1950, open-pit mining replaced underground operations, and the ASARCO-Mission complex, Twin Buttes, and Sierrita mines became large open pit operations. Accompanying copper mineralization, silver, molybdenum, zinc, lead and gold are extracted. In addition to the pits themselves, enormous leach ponds and tailings piles surround the pits. The image was acquired May 31, 2012, covers an area of 22 by 28 km, and is located at 31.9 degrees north, 111 degrees west. With its 14 spectral bands from the visible to the thermal infrared wavelength region and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched Dec. 18, 1999, on Terra. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate, Washington, D.C. More information about ASTER is available at asterweb.jpl.nasa.gov/ Credit: NASA

  17. Carbon Monoxide | Air Quality Planning Unit | Ground-level ...

    EPA Pesticide Factsheets

    2017-04-10

    Carbon monoxide (CO) is a colorless, odorless gas that can increase the severity of lung ailments, cause dizziness, fatigue, nausea, and even death. EPA has defined the national ambient air quality standard (NAAQS) for carbon monoxide as nine parts per million averaged over an eight-hour period, and this threshold cannot be exceeded more than once a year or an area would be violating the standard.

  18. [Exposure to carbon monoxide in wildland firefighters during wildfires suppression].

    PubMed

    Carballo Leyenda, Belén; Rodríguez-Marroyo, José A; López-Satué, Jorge; Avila Ordás, Concepción; Pernía Cubillo, Raúl; Villa Vicente, José Gerardo

    2010-01-01

    Health and occupational performance in wildland firefighters are mainly impaired for the carbon monoxide inhalation. Therefore, the aim of this study was to analyze the personal exposure to carbon monoxide in wildland firefighters during wildfires suppression. Carbon monoxide exposure was monitorized in 44 subjects during 58 real wildfires. Moreover, we analyzed the time weighted average exposure for an 8h shift (VA-ED). The wildfires were classified according to the work done (direct attack, indirect attack and mixed attack) and the current fuel (grass, bush, understory and mixed). The mean exposure to carbon monoxide was of 18,4 ± 1,7 ppm, what supposed a VA-ED of 7,0 ± 1,0 ppm. The highest exposures to carbon monoxide were found during the mixed attack (20,4 ± 2,3 ppm) and direct attack (17,5 ± 2,7 ppm). We only obtained significant differences (p < 0.05) between bush (19,8 ± 2,2) and understory (17,2 ± 3,9) and grass (12,0 ± 5,6). Exposures to carbon monoxide were influenced for the work done during the wildfires suppression and the type of fuel involved. Mean values obtained in this study were within safety limits described by different Spanish (INSHT) and international (NIOSH, OSHA) occupational safety and health agencies.

  19. Effect of carbon monoxide on the cardiorespiratory system: carbon monoxide toxicity, physiology and biochemistry

    SciTech Connect

    Turino, G.M.

    1981-01-01

    Exposure to carbon monoxide compromises function of the cardiovascular system primarily by decreasing oxygen-carrying capacity in the blood and decreasing venous and tissue oxygen tension. In normal individuals, with concentrations of approximately 18 to 20% COHb, there is a reduction in the oxygen consumption during high levels of exercise, a higher than predicted cardiac output, and abnormally high concentrations of lactic acid. However, in patients with coronary artery atherosclerosis, concentrations of COHb of 3 to 5% significantly curtailed exercise tolerance before the onset of angina. In addition, there is suggestive evidence in animals that the hypoxia induced by increased levels of COHb induces atherosclerosis.

  20. Carbon Monoxide: An Essential Signalling Molecule

    NASA Astrophysics Data System (ADS)

    Mann, Brian E.

    Carbon monoxide (CO), like nitric oxide (NO), is an essential signalling molecule in humans. It is active in the cardiovascular system as a vasodilator. In addition, CO possesses anti-inflammatory, anti-apoptotic and anti-proliferative properties and protects tissues from hypoxia and reperfusion injury. Some of its applications in animal models include suppression of organ graft rejection and safeguarding the heart during reperfusion after cardiopulmonary bypass surgery. CO also suppresses arteriosclerotic lesions following angioplasty, reverses established pulmonary hypertension and mitigates the development of post-operative ileus in the murine small intestine and the development of cerebral malaria in mice as well as graft-induced intimal hyperplasia in pigs. There have been several clinical trials using air-CO mixtures for the treatment of lung-, heart-, kidney- and abdominal-related diseases. This review examines the research involving the development of classes of compounds (with particular emphasis on metal carbonyls) that release CO, which could be used in clinically relevant conditions. The review is drawn not only from published papers in the chemical literature but also from the extensive biological literature and patents on CO-releasing molecules (CO-RMs).

  1. Vehicle occupant exposure to carbon monoxide.

    PubMed

    Koushki, P A; al-Dhowalia, K H; Niaizi, S A

    1992-12-01

    This paper focuses on the auto commuting micro-environment and presents typical carbon monoxide (CO) concentrations to which auto commuters in central Riyadh, Saudi Arabia were exposed. Two test vehicles traveling over four main arterial roadways were monitored for inside and outside CO levels during eighty peak and off-peak hours extending over an eight-month period. The relative importance of several variables which explained the variability in CO concentrations inside autos was also assessed. It was found that during peak hours auto commuters were exposed to mean CO levels that ranged from 30 to 40 ppm over trips that typically took between 25 to 40 minutes. The mean ratio of inside to outside CO levels was 0.84. Results of variance component analyses indicated that the most important variables affecting CO concentrations inside autos were, in addition to the smoking of vehicle occupants, traffic volume, vehicle speed, period of day and wind velocity. An increase in traffic volume from 1,000 to 5,000 vehicles per hour (vph) increased mean CO level exposure by 71 percent. An increase in vehicle speed from 14 to 55 km/h reduced mean CO exposure by 36 percent. The number of traffic interruptions had a moderate effect on mean concentrations of CO inside vehicles.

  2. Effects of carbon monoxide on myocardial ischemia

    SciTech Connect

    Allred, E.N.; Pagano, M. ); Bleecker, E.R.; Walden, S.M. ); Chaitman, B.R.; Dahms, T.E. ); Hackney, J.D.; Selvester, R.H. ); Warren, J. ); Gottlieb, S.O.

    1991-02-01

    The purpose of this study was to determine whether low doses of carbon monoxide (CO) exacerbate myocardial ischemia during a progressive exercise test. The effect of CO exposure was evaluated using the objective measure of time to development of electrocardiographic changes indicative of ischemia and the subjective measure of time to onset of angina. Sixty-three male subjects (41-75 years) with well-documented coronary artery disease, who had exertional angina pectoris and ischemic ST-segment changes in their electrocardiograms, were studied. Results from three randomized, double-blind test visits (room air, low and high CO) were compared. The effect of CO exposure was determined from the percent difference in the end points obtained on exercise tests performed before and after a 1-hr exposure to room air or CO. A significant dose-response relationship was found for the individual differences in the time to ST end point and angina for the pre-versus postexposure exercise test at the three carboxyhemoglobin levels. These findings demonstrate that low doses of CO produce significant effects on cardiac function during exercise in subjects with coronary artery disease.

  3. Carbon monoxide exposure in blast furnace workers.

    PubMed

    Lewis, S; Mason, C; Srna, J

    1992-09-01

    This study investigated the occupational exposure to carbon monoxide (CO) of a group of blast furnace workers from an integrated steelworks, compared to a control group having no significant occupational CO exposure from other areas in the same works. The study was undertaken in 1984 at Port Kembla, New South Wales. Carboxyhaemoglobin (COHb) levels before and after an eight-hour work shift were measured in 98 male steelworkers: 52 from two CO-exposed iron blast furnaces and 46 controls from production areas in the same steelworks. The sample was stratified by smoking habits. Environmental air CO levels had been found to be consistently higher on one furnace than on the other. Absorption of CO from the working environment occurred in workers on the blast furnace with higher CO levels, regardless of smoking habits. On this blast furnace, some readings of COHb levels after a workshift in nonsmokers approached the proposed Australian occupational limit of 5 per cent COHb saturation. Overall, workers with the highest occupational exposure who smoked most heavily had the highest absorption of CO over a work shift. Biological monitoring gives an accurate measure of individual worker 'dose' of CO from all sources. Both environmental monitoring and biological monitoring need to be included as part of a program for controlling occupational CO exposure.

  4. Carbon monoxide studies at high altitude.

    PubMed

    McGrath, J J

    1988-01-01

    In high altitude areas, ambient carbon monoxide (CO) concentrations are rising because of the increasing number of new residents and tourists, and their concomitant use of motor vehicles and heating appliances. There are, however, comparatively few studies of the acute or chronic physiological effects that may be caused by inhaling CO at high altitude. There are data supporting the concept that the effects of breathing CO at high altitude are additive, and data suggesting that the effects may be more than additive. Visual sensitivity and flicker fusion frequency are reduced in humans inhaling CO at high altitude. One provocative study suggests that the increase in coronary capillarity seen with chronic altitude exposure may be blocked by CO. We exposed male, laboratory rats for 6 weeks to 100 ppm CO, 4676 m (15,000 ft) simulated high altitude (SHA), and CO at SHA. SHA increase hematocrit ratio (Hct) and right ventricle weight, but decreased body weight. CO increased Hct and left ventricle weight. Our results indicate that 100 ppm CO does not exacerbate the effects produced by exposure to 4676 m altitude.

  5. Integrated Science Assessment (ISA) for Carbon Monoxide ...

    EPA Pesticide Factsheets

    EPA announced that the Second External Review Draft of the Integrated Science Assessment (ISA) for Carbon Monoxide (CO) and related Annexes was made available for independent peer review and public review. This draft ISA document represents a concise synthesis and evaluation of the most policy-relevant science and will ultimately provide the scientific bases for EPA's decision regarding whether the current standards for CO sufficiently protect public health and the environment. Section 108(a) of the Clean Air Act directs the EPA Administrator to identify certain pollutants that “cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare” and to issue air quality criteria for them. These air quality criteria are to “accurately reflect the latest scientific knowledge useful in indicating the kind and extent of all identifiable effects on public health or welfare which may be expected from the presence of such pollutant in the ambient air….” Under section 109 of the Act, EPA is to establish national ambient air quality standards (NAAQS) for each pollutant for which EPA has issued criteria. Section 109(d) of the Act requires periodic review and, if appropriate, revision of existing air quality criteria to reflect advances in scientific knowledge on the effects of the pollutant on public health or welfare. EPA is also to revise the NAAQS, if appropriate, based on the revised air quality criteria.

  6. Review: hemodynamic response to carbon monoxide

    SciTech Connect

    Penney, D.G.

    1988-04-01

    Historically, and at present, carbon monoxide is a major gaseous poison responsible for widespread morbidity and mortality. From threshold to maximal nonlethal levels, a variety of cardiovascular changes occur, both immediately and in the long term, whose homeostatic function it is to renormalize tissue oxygen delivery. However, notwithstanding numerous studies over the past century, the literature remains equivocal regarding the hemodynamic responses in animals and humans, although CO hypoxia is clearly different in several respects from hypoxic hypoxia. Factors complicating interpretation of experimental findings include species, CO dose level and rate, route of CO delivery, duration, level of exertion, state of consciousness, and anesthetic agent used. Augmented cardiac output usually observed with moderate COHb may be compromised in more sever poisoning for the same reasons, such that regional or global ischemia result. The hypotension usually seen in most animal studies is thought to be a primary cause of CNS damage resulting from acute CO poisoning, yet the exact mechanism(s) remains unproven in both animals and humans, as does the way in which CO produces hypotension. This review briefly summarizes the literature relevant to the short- and long-term hemodynamic responses reported in animals and humans. It concludes by presenting an overview using data from a single species in which the most complete work has been done to date.

  7. Elevated carboxyhemoglobin: sources of carbon monoxide exposure.

    PubMed

    Buchelli Ramirez, Herminia; Fernández Alvarez, Ramón; Rubinos Cuadrado, Gemma; Martinez Gonzalez, Cristina; Rodriguez Jerez, Francisco; Casan Clara, Pere

    2014-11-01

    Inhalation of carbon monoxide (CO) can result in poisoning, with symptoms ranging from mild and nonspecific to severe, or even death. CO poisoning is often underdiagnosed because exposure to low concentrations goes unnoticed, and threshold values for normal carboxyhemoglobin vary according to different authors. The aim of our study was to analyze carboxyhemoglobin (COHb) levels in an unselected population and detect sources of CO exposure In a cross-sectional descriptive study, we analyzed consecutive arterial blood gas levels processed in our laboratory. We selected those with COHb≥2.5% in nonsmokers and ≥5% in smokers. In these cases a structured telephone interview was conducted. Elevated levels of COHb were found in 64 (20%) of 306 initial determinations. Of these, data from 51 subjects aged 65±12 years, 31 (60%) of which were men, were obtained. Mean COHb was 4.0%. Forty patients (78%) were non-smokers with mean COHb of 3.2%, and 11 were smokers with COHb of 6.7%. In 45 patients (88.2%) we detected exposure to at least one source of ambient CO other than cigarette smoke. A significant proportion of individuals from an unselected sample had elevated levels of COHb. The main sources of CO exposure were probably the home, so this possibility should be explored. The population should be warned about the risks and encouraged to take preventive measures. Copyright © 2013 SEPAR. Published by Elsevier Espana. All rights reserved.

  8. Carbon monoxide measurements at Mace Head, Ireland

    NASA Technical Reports Server (NTRS)

    Doddridge, Bruce G.; Dickerson, Russell R.; Spain, T. Gerard; Oltmans, Samuel J.; Novelli, Paul C.

    1994-01-01

    The North Atlantic Ocean is bordered by continents which may each, under the influence of seasonal weather patterns, act as sources of natural and anthropogenic trace gas and particulate species. Photochemically active species such as carbon monoxide (CO) react to form ozone (O3), a species of critical importance in global climate change. CO is sparingly soluble in water, and the relatively long lifetime of CO in the troposphere makes this species an ideal tracer of air masses with origin over land. We have measured CO using a nondispersive infrared gas filter correlation analyzer at Mace Head on the west coast of Ireland nearly continuously since August 9, 1991. Measurements of CO were acquired at 20-sec resolution and recorded as 60-sec averages. Daily, monthly, and diurnal variation data characteristics of CO mixing ratios observed at this site are reported. Depending on source regions of air parcels passing over this site, 60-min concentrations of CO range from clean air values of approximately 90 ppbv to values in excess of 300 ppbv. Data characterizing the correlation between 60-min CO and O3 mixing ratio data observed at this site are reported also.

  9. Integrated Science Assessment (ISA) for Carbon Monoxide ...

    EPA Pesticide Factsheets

    EPA announced that the Second External Review Draft of the Integrated Science Assessment (ISA) for Carbon Monoxide (CO) and related Annexes was made available for independent peer review and public review. This draft ISA document represents a concise synthesis and evaluation of the most policy-relevant science and will ultimately provide the scientific bases for EPA's decision regarding whether the current standards for CO sufficiently protect public health and the environment. Section 108(a) of the Clean Air Act directs the EPA Administrator to identify certain pollutants that “cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare” and to issue air quality criteria for them. These air quality criteria are to “accurately reflect the latest scientific knowledge useful in indicating the kind and extent of all identifiable effects on public health or welfare which may be expected from the presence of such pollutant in the ambient air….” Under section 109 of the Act, EPA is to establish national ambient air quality standards (NAAQS) for each pollutant for which EPA has issued criteria. Section 109(d) of the Act requires periodic review and, if appropriate, revision of existing air quality criteria to reflect advances in scientific knowledge on the effects of the pollutant on public health or welfare. EPA is also to revise the NAAQS, if appropriate, based on the revised air quality criteria.

  10. Myth busting in carbon monoxide poisoning.

    PubMed

    Hampson, Neil B

    2016-02-01

    The evidence supporting many beliefs in medicine is based upon opinion, personal experience, hearsay, or "common knowledge." When one searches for the data supporting oft-quoted facts in medicine, they are sometimes found to be old, incorrect, or nonexistent. Such unsupported facts or beliefs can be termed myths. This minireview will summarize 4 examples of "myth busting" by the author when he has discovered widely held beliefs regarding carbon monoxide (CO) poisoning to be untrue during a 25-year career of research in the field. These include the mistaken beliefs that (1) symptoms correlate with presenting blood carboxyhemoglobin levels, (2) residents are safe from CO poisoning if their home does not contain fuel-burning appliances, (3) carboxyhemoglobin levels must be measured rapidly and on arterial blood, and (4) CO poisoning predisposes to premature long-term death from cardiac disease. In addition to providing the evidence disproving these myths, the importance of going back to the original reference when citing prior work is emphasized. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Carbon monoxide and anesthesia-induced neurotoxicity☆

    PubMed Central

    Levy, Richard J.

    2016-01-01

    The majority of commonly used anesthetic agents induce widespread neuronal degeneration in the developing mammalian brain. Downstream, the process appears to involve activation of the oxidative stress-associated mitochondrial apoptosis pathway. Targeting this pathway could result in prevention of anesthetic toxicity in the immature brain. Carbon monoxide (CO) is a gas that exerts biological activity in the developing brain and low dose exposures have the potential to provide neuroprotection. In recent work, low concentration CO exposures limited isoflurane-induced neuronal apoptosis in a dose-dependent manner in newborn mice and modulated oxidative stress within forebrain mitochondria. Because infants and children are routinely exposed to low levels of CO during low-flow general endotracheal anesthesia, such anti-oxidant and pro-survival cellular effects are clinically relevant. Here we provide an overview of anesthesia-related CO exposure, discuss the biological activity of low concentration CO, detail the effects of CO in the brain during development, and provide evidence for CO-mediated inhibition of anesthesia-induced neurotoxicity. PMID:27616667

  12. Overabundance of carbon monoxide in calorimetry tests

    SciTech Connect

    Ree, F.H.; Pitz, W.J.; Thiel, M. van; Souers, P.C.

    1996-04-04

    The amount of carbon monoxide recovered from calorimetry tests of high explosives is far larger than the amount predicted by equilibrium calculations. The present kinetics study of PETN [(nitro(oxy)methyl]-propanediol dinitrate) has revealed that the cooling of the calorimetry bomb after detonation of a PETN sample sufficiently slows those reactions that would otherwise lead to equilibrium so that these reactions are effectively frozen in the time scale of recovery of detonation products. Among these reactions, those that can create CH{sub 4} are the most important ones. Their rates are generally slow at all temperatures relevant to calorimetry tests. This and the slowing down of a reaction, CO + H{sub 2}O {yields} H{sub 2} + CO{sub 2} at temperatures below 1500 K are the main caus of the freeze-out of CO. A possible slow rate of the soot formation (i.e., condensed carbon) is not responsible for it. The sensitivity of the present result to the cooling rate of the detonation products and to free radicals is also examined. 10 refs., 5 figs., 2 tabs.

  13. A peroxynitrite complex of copper: formation from a copper-nitrosyl complex, transformation to nitrite and exogenous phenol oxidative coupling or nitration.

    PubMed

    Park, Ga Young; Deepalatha, Subramanian; Puiu, Simona C; Lee, Dong-Heon; Mondal, Biplab; Narducci Sarjeant, Amy A; del Rio, Diego; Pau, Monita Y M; Solomon, Edward I; Karlin, Kenneth D

    2009-11-01

    Reaction of nitrogen monoxide with a copper(I) complex possessing a tridentate alkylamine ligand gives a Cu(I)-(*NO) adduct, which when exposed to dioxygen generates a peroxynitrite (O=NOO(-))-Cu(II) species. This undergoes thermal transformation to produce a copper(II) nitrito (NO(2) (-)) complex and 0.5 mol equiv O(2). In the presence of a substituted phenol, the peroxynitrite complex effects oxidative coupling, whereas addition of chloride ion to dissociate the peroxynitrite moiety instead leads to phenol ortho nitration. Discussions include the structures (including electronic description) of the copper-nitrosyl and copper-peroxynitrite complexes and the formation of the latter, based on density functional theory calculations and accompanying spectroscopic data.

  14. Carbon monoxide. Toxic gas and fuel for anaerobes and aerobes: carbon monoxide dehydrogenases.

    PubMed

    Jeoung, Jae-Hun; Fesseler, Jochen; Goetzl, Sebastian; Dobbek, Holger

    2014-01-01

    Carbon monoxide (CO) pollutes the atmosphere and is toxic for respiring organisms including man. But CO is also an energy and carbon source for phylogenetically diverse microbes living under aerobic and anaerobic conditions. Use of CO as metabolic fuel for microbes relies on enzymes like carbon monoxide dehydrogenase (CODH) and acetyl-CoA synthase (ACS), which catalyze conversions resembling processes that eventually initiated the dawn of life.CODHs catalyze the (reversible) oxidation of CO with water to CO2 and come in two different flavors with unprecedented active site architectures. Aerobic bacteria employ a Cu- and Mo-containing CODH in which Cu activates CO and Mo activates water and takes up the two electrons generated in the reaction. Anaerobic bacteria and archaea use a Ni- and Fe-containing CODH, where Ni activates CO and Fe provides the nucleophilic water. Ni- and Fe-containing CODHs are frequently associated with ACS, where the CODH component reduces CO2 to CO and ACS condenses CO with a methyl group and CoA to acetyl-CoA.Our current state of knowledge on how the three enzymes catalyze these reactions will be summarized and the different strategies of CODHs to achieve the same task within different active site architectures compared.

  15. Determination of the atherogenic potential of inhaled carbon monoxide

    SciTech Connect

    Penn, A. )

    1993-05-01

    he effects of chronic exposure to moderate levels of carbon monoxide upon the augmentation of arteriosclerotic plaque development were investigated in a series of in vivo studies in the cockerel (young rooster). This animal model has been well characterized, especially regarding the role of environmental agents in exacerbating early stages of plaque development. Cockerels injected with subtumorigenic doses of carcinogens exhibit markedly accelerated development of aortic arteriosclerotic plaques. Inhalation of mainstream smoke from two packs of cigarettes (100 minutes/day for 16 weeks) causes small but statistically significant increases in plaque size. As is the case with many animal models of plaque development, raised fat-proliferative plaques also appear in these animals following cholesterol feeding. Carbon monoxide is a ubiquitous pollutant in urban environments, where it is derived largely from mobile sources and cigarette smoke. Exposure to chronically elevated carbon monoxide levels has been implicated in a number of health-related problems. Whether such exposure plays a role in the development of arteriosclerosis has not been determined conclusively. In the present study, three questions were posed: 1. Will inhaled carbon monoxide at levels of 50 to 200 parts per million (ppm)* (two hours/day for 16 weeks) be sufficient to augment arteriosclerotic plaque development in cockerels, in the absence of other plaque-promoting agents 2. Will the inhalation of 100 ppm carbon monoxide (two hours/day for 16 weeks), concomitant with the feeding of low levels (0.1%) of cholesterol, yield larger plaques than those obtained with either of these agents administered alone 3. Will inhalation of 100 ppm carbon monoxide (two hours/day for 11 or 22 weeks), by cockerels in whom plaques have already appeared, further augment plaque development Cockerels were exposed to carefully regulated levels of carbon monoxide in stainless-steel and Plexiglas dynamic exposure chambers.

  16. Acute effects of carbon monoxide on cardiac electrical stability

    SciTech Connect

    Verrier, R.L.; Mills, A.K.; Skornik, W.A. )

    1990-10-01

    The objective of this project was to determine the effects of acute carbon monoxide exposure on cardiac electrical stability. To obtain a comprehensive assessment, diverse biological models were employed. These involved cardiac electrical testing in the normal and ischemic heart in anesthetized and conscious dogs. The experimental plan was designed both to examine the direct effects of carbon monoxide exposure on the myocardium and to evaluate possible indirect influences through alterations in platelet aggregability or changes in central nervous system activity in the conscious animal. Our results indicate that exposure to relatively high levels of carbon monoxide, leading to carboxyhemoglobin concentrations of up to 20 percent, is without significant effect on ventricular electrical stability. This appears to be the case in the acutely ischemic heart as well as in the normal heart. It is important to note that the total exposure period was in the range of 90 to 124 minutes. The possibility that longer periods of exposure or exacerbation from nicotine in cigarette smoke could have a deleterious effect cannot be excluded. We also examined whether or not alterations in platelet aggregability due to carbon monoxide exposure could be a predisposing factor for cardiac arrhythmias. A model involving partial coronary artery stenosis was used to simulate the conditions under which platelet plugs could lead to myocardial ischemia and life-threatening arrhythmias. We found no changes either in the cycle frequency of coronary blood flow oscillations or in platelet aggregability during carbon monoxide exposure. Thus, carbon monoxide exposure does not appear to alter platelet aggregability or its effect on coronary blood flow during stenosis. In the final series of experiments, we examined the effects of carbon monoxide exposure in the conscious state.

  17. Carbon Monoxide Oxidation by Clostridium thermoaceticum and Clostridium formicoaceticum

    PubMed Central

    Diekert, Gabriele B.; Thauer, Rudolf K.

    1978-01-01

    Cultures of Clostridium formicoaceticum and C. thermoaceticum growing on fructose and glucose, respectively, were shown to rapidly oxidize CO to CO2. Rates up to 0.4 μmol min−1 mg of wet cells−1 were observed. Carbon monoxide oxidation by cell suspensions was found (i) to be dependent on pyruvate, (ii) to be inhibited by alkyl halides and arsenate, and (iii) to stimulate CO2 reduction to acetate. Cell extracts catalyzed the oxidation of carbon monoxide with methyl viologen at specific rates up to 10 μmol min−1 mg of protein−1 (35°C, pH 7.2). Nicotinamide adenine dinucleotide, nicotinamide adenine dinucleotide phosphate and ferredoxin from C. pasteurianum were ineffective as electron acceptors. The catalytic mechanism of carbon monoxide oxidation was “ping-pong,” indicating that the enzyme catalyzing carbon monoxide oxidation can be present in an oxidized and a reduced form. The oxidized form was shown to react reversibly with cyanide, and the reduced form was shown to react reversibly with alkyl halides: cyanide inactivated the enzyme only in the absence of carbon monoxide, and alkyl halides inactivated it only in the presence of carbon monoxide. Extracts inactivated by alkyl halides were reactivated by photolysis. The findings are interpreted to indicate that carbon monoxide oxidation in the two bacteria is catalyzed by a corrinoid enzyme and that in vivo the reaction is coupled with the reduction of CO2 to acetate. Cultures of C. acidi-urici and C. cylindrosporum growing on hypoxanthine were found not to oxidize CO, indicating that clostridia mediating a corrinoid-independent total synthesis of acetate from CO2 do not possess a CO-oxidizing system. PMID:711675

  18. Carbon Monoxide Poisoning from Portable Electrical Generators.

    PubMed

    Hampson, Neil B; Dunn, Susan L

    2015-08-01

    Portable electrical generators have been responsible for over 800 accidental carbon monoxide (CO) poisoning deaths in the United States from 1999-2012. Because mortality figures are typically the only data reported with regard to the adverse effects of generators, we describe a nonfatal segment of the poisoned population to further emphasize the significance of the problem. Unidentifiable information about patients treated in the United States with hyperbaric oxygen for acute CO poisoning was prospectively reported by participating centers. Those patients poisoned by portable generators were selected for analysis. Of 1604 patients reported from August 1, 2008 to July 31, 2011, there were 264 accidentally poisoned by portable generators. Exposures occurred in 151 incidents in 33 states. In 99 incidents, poisoning occurred in a residence. Average patient age was 37 ± 20 years (range 1 to 90+ years). Of those poisoned, 146 (55%) were non-Hispanic white, 57 (22%) were black, 52 (20%) were Hispanic white, 4 (2%) were Asian, and 4 (2%) were Native American. English was spoken by 96%. The most common symptoms included headache (62%), dizziness (52%), and loss of consciousness (50%). Blood carboxyhemoglobin levels averaged 22.7 ± 9.0% (range 2.3-48.3%). Thirty-six patients demonstrated evidence of cardiac ischemia. Acute, severe CO poisoning from portable electric generators is common in the United States, likely affecting an estimated 4000 individuals annually, occurring predominantly in residential settings, and affecting English language-speaking individuals. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Ambulatory measurement of ambient carbon monoxide levels.

    PubMed

    Hampson, Neil B; Courtney, Todd G; Holm, James R

    2015-01-01

    Measurement of air pollutant levels in the environment is traditionally performed using monitors in fixed locations so that changes over time can be directly compared. Such measurements do not necessarily correlate with the level of exposure to the individual because of distance to the monitoring site and other factors. In the case of carbon monoxide (CO), portable personal monitors are available for industrial use, some of which do not just alarm, but also record measured values. First, it was the purpose of this study to test the feasibility of continuously measuring ambient CO levels in an ambulatory fashion. The second objective was to compare measurements made in a country with significant air pollution to one without to determine the degree to which differences might be observed. Ambient CO levels were measured and recorded every 10 minutes during 13 days of travel in Vietnam. A parallel study was performed in the United States for comnarison. Continuous ambient CO levels at an individual level were successfully measured and recorded. Mean ambient CO level throughout Vietnam was 3.5 ± 4.4 ppm, as compared to 0.9 ± 0.8 ppm in the U.S. (p < 0.001). In Vietnam, 36 CO measurements (2% of total) were 15 ppm or greater vs. none in the U.S. Higher mean levels, as well as number and magnitude of peaks, were highly associated with proximity to traffic. Personal exposures to CO can be measured easily over time and may be more relevant to the individual with underlying disease than data from fixed monitoring stations. Such information may prove useful to potential travelers. Additionally, governmental agencies may find ambulatory measurement to be complimentary to data from fixed monitoring stations when attempting to estimate how traditionally collected data relate to exposure of the individual. The technique could also be used for evaluation of vague complaints suggestive of intermittent CO exposure in the home or workplace.

  20. The Carbon Monoxide Dehydrogenase from Desulfovibrio vulgaris.

    PubMed

    Hadj-Saïd, Jessica; Pandelia, Maria-Eirini; Léger, Christophe; Fourmond, Vincent; Dementin, Sébastien

    2015-12-01

    Ni-containing Carbon Monoxide Dehydrogenases (CODHs) catalyze the reversible conversion between CO and CO₂and are involved in energy conservation and carbon fixation. These homodimeric enzymes house two NiFeS active sites (C-clusters) and three accessory [4Fe-4S] clusters. The Desulfovibrio vulgaris (Dv) genome contains a two-gene CODH operon coding for a CODH (cooS) and a maturation protein (cooC) involved in nickel insertion in the active site. According to the literature, the question of the precise function of CooC as a chaperone folding the C-cluster in a form which accommodates free nickel or as a mere nickel donor is not resolved. Here, we report the biochemical and spectroscopic characterization of two recombinant forms of the CODH, produced in the absence and in the presence of CooC, designated CooS and CooS(C), respectively. CooS contains no nickel and cannot be activated, supporting the idea that the role of CooC is to fold the C-cluster so that it can bind nickel. As expected, CooS(C) is Ni-loaded, reversibly converts CO and CO₂, displays the typical Cred1 and Cred2 EPR signatures of the C-cluster and activates in the presence of methyl viologen and CO in an autocatalytic process. However, Ni-loaded CooS(C) reaches maximum activity only upon reductive treatment in the presence of exogenous nickel, a phenomenon that had not been observed before. Surprisingly, the enzyme displays the Cred1 and Cred2 signatures whether it has been activated or not, showing that this activation process of the Ni-loaded Dv CODH is not associated with structural changes at the active site.

  1. Pulmonary Phototherapy for Treating Carbon Monoxide Poisoning

    PubMed Central

    Zazzeron, Luca; Liu, Chen; Franco, Walfre; Nakagawa, Akito; Farinelli, William A.; Bloch, Donald B.; Anderson, R. Rox

    2015-01-01

    Rationale: Carbon monoxide (CO) exposure is a leading cause of poison-related mortality. CO binds to Hb, forming carboxyhemoglobin (COHb), and produces tissue damage. Treatment of CO poisoning requires rapid removal of CO and restoration of oxygen delivery. Visible light is known to effectively dissociate CO from Hb, with a single photon dissociating one CO molecule. Objectives: To determine whether illumination of the lungs of CO-poisoned mice causes dissociation of COHb from blood transiting the lungs, releasing CO into alveoli and thereby enhancing the rate of CO elimination. Methods: We developed a model of CO poisoning in anesthetized and mechanically ventilated mice to assess the effects of direct lung illumination (phototherapy) on the CO elimination rate. Light at wavelengths between 532 and 690 nm was tested. The effect of lung phototherapy administered during CO poisoning was also studied. To avoid a thoracotomy, we assessed the effect of lung phototherapy delivered to murine lungs via an optical fiber placed in the esophagus. Measurements and Main Results: In CO-poisoned mice, phototherapy of exposed lungs at 532, 570, 592, and 628 nm dissociated CO from Hb and doubled the CO elimination rate. Phototherapy administered during severe CO poisoning limited the blood COHb increase and improved the survival rate. Noninvasive transesophageal phototherapy delivered to murine lungs via an optical fiber increased the rate of CO elimination while avoiding a thoracotomy. Conclusions: Future development and scaling up of lung phototherapy for patients with CO exposure may provide a significant advance for treating and preventing CO poisoning. PMID:26214119

  2. Pulmonary vascular stress from carbon monoxide.

    PubMed

    Thom, S R; Ohnishi, S T; Fisher, D; Xu, Y A; Ischiropoulos, H

    1999-01-01

    Studies were conducted with rats to investigate whether exposure to carbon monoxide (CO) at concentrations frequently found in the environment caused lung injury mediated by nitric oxide (*NO)-derived oxidants. Lung capillary leakage was significantly increased 18 h after rats had been exposed to CO at concentrations of 50 ppm or more for 1 h. An elevation of *NO during CO exposure was demonstrated by electron paramagnetic resonance spectroscopy. There was a 2.6-fold increase of *NO over control in the lungs of rats exposed to 100 ppm CO. A qualitative increase in the concentration of H2O2 was also detected in lungs during CO exposure, and this change was caused by *NO as it was inhibited in rats pretreated with the nitric oxide synthase inhibitor, Nomega nitro-l-arginine methyl ester (l-NAME). Production of *NO-derived oxidants during CO exposure was indicated by an elevated concentration of nitrotyrosine in lung homogenates. The CO-associated elevations in lung capillary leakage and nitrotyrosine concentration did not occur when rats were pretreated with l-NAME. CO exposure did not change the concentrations of endothelial or inducible nitric oxide synthase in lung and leukocyte sequestration was not detected as a consequence of CO exposure. CO-mediated lung leak and nitrotyrosine elevation were not affected by neutropenia. We conclude that CO exposure elevates the steady-state concentration of *NO in lungs. Consequences from this change include increases in the concentration of reactive oxygen species, production of *NO-derived oxidants such as peroxynitrite, and physiological evidence of lung injury.

  3. Investigating carbon monoxide exposure on Denali.

    PubMed

    Roscoe, Clay; Baker, Ed; Gustafson, Caitlin; Arndt, Todd; Dow, Jennifer; Johnston, Emily; Brillhart, Aaron

    2006-01-01

    This exploratory study assessed a potential relationship between elevated carboxyhemoglobin (COHb) levels and acute mountain sickness (AMS) at 4300 m on Denali. Additional analysis assessed the relationship among COHb levels, AMS, and climber characteristics and behaviors. Participants were screened for AMS with the Lake Louise Self-Report questionnaire and answered questions focusing on AMS symptoms, prevention, and previous altitude illness. Levels of COHb were measured by serum cooximetry. Additional questions assessed stove practices, climbing practices, and climber behaviors. Nonparametric statistical analyses were performed to examine potential relationships among COHb levels, AMS symptoms, and climber behaviors. A total of 146 climbers participated in the study. Eighteen climbers (12.5%) were positive for carbon monoxide (CO) exposure and 20 (13.7%) met criteria for AMS. No significant relationship was observed between positive CO exposure and positive criteria for AMS. Climbers descending the mountain were 3.6 times more likely to meet the study criteria for positive CO exposure compared with those ascending the mountain (P = .42). In addition, COHb levels were significantly higher for those descending the mountain (P = .012) and for those taking prophylactic medications (P = .010). Climbers meeting positive criteria for AMS operated their stoves significantly longer (P = .047). No significant relationship between AMS symptoms and CO exposure was observed. This may have been affected by the low percentage of climbers reporting AMS symptoms, as well as limited power. Descending climbers had a 3.6 times increased risk of CO exposure compared with ascending climbers and had significantly higher COHb scores. Increased hours of stove operation was significantly linked to climbers who also met criteria for AMS.

  4. Decadal Record of Satellite Carbon Monoxide Observations

    NASA Astrophysics Data System (ADS)

    Worden, Helen; Deeter, Merritt; Frankenberg, Christian; George, Maya; Nichitiu, Florian; Worden, John; Aben, Ilse; Bowman, Kevin; Clerbaux, Cathy; Coheur, Pierre-Francois; de Laat, Jos; Warner, Juying; Drummond, James; Edwards, David; Gille, John; Hurtmans, Daniel; Ming, Luo; Martinez-Alonso, Sara; Massie, Steven; Pfister, Gabriele

    2013-04-01

    Atmospheric carbon monoxide (CO) distributions are controlled by anthropogenic emissions, biomass burning, chemical production, transport and oxidation by reaction with the hydroxyl radical (OH). Quantifying trends in CO is therefore important for understanding changes related to all of these contributions. Here we present a comprehensive record of satellite observations from 2000 through 2011 of total column CO using the available measurements from nadir-viewing thermal infrared instruments: MOPITT, AIRS, TES and IASI. We examine trends for CO in the Northern and Southern hemispheres along with regional trends for E. China, E. USA, Europe and India. Measurement and sampling methods for each of the instruments are discussed, and we show diagnostics for systematic errors in MOPITT trends. We find that all the satellite observations are consistent with a modest decreasing trend around -1%/year in total column CO over the Northern hemisphere for this time period. Decreasing trends in total CO column are observed for the United States, Europe and E. China with more than 2σ significance. For India, the trend is also decreasing, but smaller in magnitude and less significant. Decreasing trends in surface CO have also been observed from measurements in the U.S. and Europe. Although less information is available for surface CO in China, there is a decreasing trend reported for Beijing. Some of the interannual variability in the observations can be explained by global fire emissions, and there may be some evidence of the global financial crisis in late 2008 to early 2009. But the overall decrease needs further study to understand the implications for changes in anthropogenic emissions.

  5. Synthesis and electrochemical properties of nanosized LiFeO{sub 2} particles with a layered rocksalt structure for lithium batteries

    SciTech Connect

    Hirayama, Masaaki; Tomita, Hiroki; Kubota, Kei; Ido, Hidekazu; Kanno, Ryoji

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer 40-nm-sized O3-LiFeO{sub 2} exhibits higher discharge capacities and rate characteristics than 400-nm-sized O3-LiFeO{sub 2}. Black-Right-Pointing-Pointer The cation disorder of Li and Fe ions might have affected the electrochemical activity of the O3-LiFeO{sub 2} nanoparticles. Black-Right-Pointing-Pointer A phase change from a layered structure to a cubic structure during electrochemical cycling. Black-Right-Pointing-Pointer The new cubic phase allowed a stable electrochemical reaction between 4.5 and 1.0 V. -- Abstract: Layered rocksalt-type LiFeO{sub 2} particles (O3-LiFeO{sub 2}) with average particle sizes of ca. 40 and 400 nm were synthesized by an ion exchange reaction from {alpha}-NaFeO{sub 2} precursors. X-ray diffraction (XRD) patterns and scanning electron microscopy (SEM) images confirmed the formation of nanosized O3-LiFeO{sub 2}. 40-nm LiFeO{sub 2} exhibited a higher discharge capacity (115 mAh g{sup -1}) than 400-nm LiFeO{sub 2} (80 mAh g{sup -1}), and also had better rate characteristics. The downsizing effect and cation disorder between the lithium and iron layers may have improved the electrochemical activity of the LiFeO{sub 2} particles. Transmission electron microscopy (TEM) observation indicated a phase transition from O3-LiFeO{sub 2} to a cubic lattice system during the electrochemical process. The cubic lithium iron oxide exhibited stable electrochemical reactions based on the Fe{sup 2+}/Fe{sup 3+} and Fe{sup 2+}/Fe{sup 0} redox couples at voltages between 4.5 and 1.0 V. The discharge capacities of 40-nm LiFeO{sub 2} were ca. 115, 210, and 390 mAh g{sup -1} under cutoff voltages of 4.5-2.0 V, 4.5-1.5 V, and 4.5-1.0 V, respectively.

  6. Synthesis of monodispersed bimetallic palladium-copper nanoscale colloids

    SciTech Connect

    Bradley, J.S.; Hill, E.W.; Klein, C. ); Chaudret, B.; Duteil, A. )

    1993-03-01

    Bimetallic clusters have been the subject of many studies of the surface chemistry and catalytic properties of metal crystallites on solid supports. Mixtures of palladium acetate and copper acetate were refluxed in 2-ethoxyethanol in the presence of poly(vinylpyrrolidone) to give 40-[angstrom] alloy nanoclusters. TEM and EDAX analysis showed that the particles were homogeneously bimetallic and crystalline, with a composition determined by the ratio of the metal acetates used. Carbon monoxide adsorbed on the colloidal particles binds reversibly to both metals. 9 refs., 3 figs.

  7. Carbon monoxide binding to human hemoglobin A0.

    PubMed

    Di Cera, E; Doyle, M L; Connelly, P R; Gill, S J

    1987-10-06

    The carbon monoxide binding curve to human hemoglobin A0 has been measured to high precision in experimental conditions of 600 microM heme, 0.1 M N-(2-hydroxyethyl)piperazine-N'-2-ethanesulfonic acid, 0.1 M NaCl, 10 mM inositol hexaphosphate, 1 mM disodium ethylenediaminetetraacetic acid, pH 6.94, and 25 degrees C. Comparison to the oxygen binding curve in the same experimental conditions demonstrates that the two curves are not parallel. This result invalidates Haldane's two laws for the partitioning between carbon monoxide and oxygen to human hemoglobin. The partition coefficient is found to be 263 +/- 27 at high saturation, in agreement with previous studies, but is lowered substantially at low saturation. Although the oxygen and carbon monoxide binding curves are not parallel, both show the population of the triply ligated species to be negligible. The molecular mechanism underlying carbon monoxide binding to hemoglobin is consistent with the allosteric model [Di Cera, E., Robert, C. H., & Gill, S. J. (1987) Biochemistry 26, 4003-4008], which accounts for the negligible contribution of the triply ligated species in the oxygen binding reaction to hemoglobin [Gill, S. J., Di Cera, E., Doyle, M. L., Bishop, G. A., & Robert, C. H. (1987) Biochemistry 26, 3995-4002]. The nature of the different binding properties of carbon monoxide stems largely from the lower partition coefficient of the T state (123 +/- 34), relative to the R state (241 +/- 19).(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Encapsulation kinetics and dynamics of carbon monoxide in clathrate hydrate

    PubMed Central

    Zhu, Jinlong; Du, Shiyu; Yu, Xiaohui; Zhang, Jianzhong; Xu, Hongwu; Vogel, Sven C.; Germann, Timothy C.; Francisco, Joseph S.; Izumi, Fujio; Momma, Koichi; Kawamura, Yukihiko; Jin, Changqing; Zhao, Yusheng

    2014-01-01

    Carbon monoxide clathrate hydrate is a potentially important constituent in the solar system. In contrast to the well-established relation between the size of gaseous molecule and hydrate structure, previous work showed that carbon monoxide molecules preferentially form structure-I rather than structure-II gas hydrate. Resolving this discrepancy is fundamentally important to understanding clathrate formation, structure stabilization and the role the dipole moment/molecular polarizability plays in these processes. Here we report the synthesis of structure-II carbon monoxide hydrate under moderate high-pressure/low-temperature conditions. We demonstrate that the relative stability between structure-I and structure-II hydrates is primarily determined by kinetically controlled cage filling and associated binding energies. Within hexakaidecahedral cage, molecular dynamic simulations of density distributions reveal eight low-energy wells forming a cubic geometry in favour of the occupancy of carbon monoxide molecules, suggesting that the carbon monoxide–water and carbon monoxide–carbon monoxide interactions with adjacent cages provide a significant source of stability for the structure-II clathrate framework. PMID:24936712

  9. Effects of substitution, pressure, and temperature on the phonon mode in layered-rocksalt-type Li(1-x/2)Ga(1-x/2)ZnxO (x = 0.036-0.515) alloys

    NASA Astrophysics Data System (ADS)

    Tan, Lijie; Hu, Qiwei; Lei, Li; Jiang, Xiaodong; Gao, Shangpan; He, Duanwei

    2015-11-01

    ZnO-based semiconductor alloys, Li(1-x/2)Ga(1-x/2)ZnxO (x = 0.036-0.515) with a layered-rocksalt-type structure, have been prepared under high pressure. The composition, pressure, and temperature dependence of phonons have been studied by Raman spectroscopy. We observe two disorder-activated Raman (DAR) modes when the Zn composition x increases: a broad Raman peak at ca. 400 cm-1 and a left-shoulder peak at ca. 530 cm-1 on the low-frequency side of A1g mode at ca. 580 cm-1, which can be explained by reference to the phonon density of states for rocksalt-type ZnO. With the increase of the pressure and temperature, the left-shoulder DAR mode induced by substitution does not change at the same pace with the A1g mode at Brillouin-zone center. We find that ion substitution can be seen as a kind of chemical pressure, and the chemical pressure caused by internal substitution and the physical pressure caused by external compression have equivalent effects on the shortening of correlation length, the distortion of crystal lattice, and the change of atomic occupation.

  10. Order, miscibility, and electronic structure of Ag(Bi,Sb)Te2 alloys and (Ag,Bi,Sb)Te precipitates in rocksalt matrix. A first-principles study

    SciTech Connect

    Barabash, V.; Ozolins, Vidvuds

    2010-02-23

    Using first-principles density-functional theory calculations and cluster expansion, we predict that AgBiTe2 -AgSbTe2 alloys exhibit D4 cation order at all temperatures below melting and are fully miscible down to the room temperature and below. We also discuss the miscibility and ordering on the cation sublattice in quasiternary (Ag,Bi,Sb)Te alloys with general composition, within the subclass of structures with rocksalt topology (relevant for the case of coherent precipitates in a rocksalt matrix, e.g., in PbTe). The band structures of the AgBiTe2 and AgSbTe2 compounds and the evolution of the Fermi-surface topology at low hole dopings are presented. We use these results to refine the interpretation of the recent experimental measurements on naturally doped AgSbTe2 samples reported by Jovovic and Heremans [Phys. Rev. B 77, 245204 (2008)] and present a simplified model of the band dispersion near the valence-band maximum.

  11. Copper:caeruloplasmin ratio

    PubMed Central

    Twomey, Patrick J; Viljoen, Adie; House, Ivan M; Reynolds, Timothy M; Wierzbicki, Anthony S

    2007-01-01

    Investigation of copper status can be a diagnostic challenge. The non‐caeruloplasmin‐bound copper (NCC) has deficiencies; accordingly, the copper:caeruloplasmin ratio has been suggested as an alternative index of copper status. A reference interval for this index was derived. In addition to making the interpretation of copper easier, the copper:caeruloplasmin ratio should also enable adjustment for relatively high caeruloplasmin concentrations without recourse to producing gender‐ and age‐derived intervals. The copper:caeruloplasmin ratio has weaknesses similar to those identified for NCC in that immunological methods used for caeruloplasmin can cross react with apocaeruloplasmin and there is no standardised method for caeruloplasmin. Caeruloplasmin assays also have uncertainty from precision, bias and specificity and, accordingly, method‐related differences may have a large effect on the copper:caeruloplasmin ratio in a manner similar to the NCC. PMID:17405985

  12. Aquatic Life Criteria - Copper

    EPA Pesticide Factsheets

    Documents pertain to Aquatic Life Ambient Water Quality criteria for Copper (2007 Freshwater, 2016 Estuarine/marine). These documents contain the safe levels of Copper in water that should protect to the majority of species.

  13. Subsurface Oxygen in Oxide-Derived Copper Electrocatalysts for Carbon Dioxide Reduction

    DOE PAGES

    Eilert, Andre; Cavalca, Filippo; Roberts, F. Sloan; ...

    2016-12-16

    Copper electrocatalysts derived from an oxide have shown extraordinary electrochemical properties for the carbon dioxide reduction reaction (CO2RR). Using in situ ambient pressure X-ray photoelectron spectroscopy and quasi in situ electron energy-loss spectroscopy in a transmission electron microscope, we show that there is a substantial amount of residual oxygen in nanostructured, oxide-derived copper electrocatalysts but no residual copper oxide. On the basis of these findings in combination with density functional theory simulations, we propose that residual subsurface oxygen changes the electronic structure of the catalyst and creates sites with higher carbon monoxide binding energy. If such sites are stable undermore » the strongly reducing conditions found in CO2RR, these findings would explain the high efficiencies of oxide-derived copper in reducing carbon dioxide to multicarbon compounds such as ethylene.« less

  14. Subsurface Oxygen in Oxide-Derived Copper Electrocatalysts for Carbon Dioxide Reduction

    SciTech Connect

    Eilert, Andre; Cavalca, Filippo; Roberts, F. Sloan; Osterwalder, Jurg; Liu, Chang; Favaro, Marco; Crumlin, Ethan J.; Ogasawara, Hirohito; Friebel, Daniel; Pettersson, Lars G. M.; Nilsson, Anders

    2016-12-16

    Copper electrocatalysts derived from an oxide have shown extraordinary electrochemical properties for the carbon dioxide reduction reaction (CO2RR). Using in situ ambient pressure X-ray photoelectron spectroscopy and quasi in situ electron energy-loss spectroscopy in a transmission electron microscope, we show that there is a substantial amount of residual oxygen in nanostructured, oxide-derived copper electrocatalysts but no residual copper oxide. On the basis of these findings in combination with density functional theory simulations, we propose that residual subsurface oxygen changes the electronic structure of the catalyst and creates sites with higher carbon monoxide binding energy. If such sites are stable under the strongly reducing conditions found in CO2RR, these findings would explain the high efficiencies of oxide-derived copper in reducing carbon dioxide to multicarbon compounds such as ethylene.

  15. Performance and Emission Analysis of Diesel Engine by Copper Coating Over Piston Crown and Cylinder Head

    NASA Astrophysics Data System (ADS)

    Yuvaraja, S.; Mathiselvan, G.; Gobinath, R.

    2017-05-01

    The major toxins emitted from SI engine are carbon monoxide (CO) and unburnt hydrocarbons (UHC). These are harmful and create health problems to human beings, and hence control of these pollutants calls for instant attention. It has been recognized from the literature review that copper coating inside the cylinder head and over the piston crown will reduce the emission and increase the overall performance. Hence, in this Project work piston crown and engine head are coated using copper and experiment are conducted. A Kirloskar AV1 engine is used for conducting experiment. The copper coated piston crown and engine head is used to reduce the emission (HC, CO, O2, and CO2). The performance and characteristics of the copper coated engine has been studied.

  16. Effects of carbon monoxide on myocardial ischemia.

    PubMed Central

    Allred, E N; Bleecker, E R; Chaitman, B R; Dahms, T E; Gottlieb, S O; Hackney, J D; Pagano, M; Selvester, R H; Walden, S M; Warren, J

    1991-01-01

    The purpose of this study was to determine whether low doses of carbon monoxide (CO) exacerbate myocardial ischemia during a progressive exercise test. The effect of CO exposure was evaluated using the objective measure of time to development of electrocardiographic changes indicative of ischemia and the subjective measure of time to onset of angina. Sixty-three male subjects (41-75 years) with well-documented coronary artery disease, who had exertional angina pectoris and ischemic ST-segment changes in their electrocardiograms, were studied. Results from three randomized, double-blind test visits (room air, low and high CO) were compared. The effect of CO exposure was determined from the percent difference in the end points obtained on exercise tests performed before and after a 1-hr exposure to room air or CO. The exposures resulted in postexercise carboxyhemoglobin (COHb) levels of 0.6% +/- 0.3%, 2.0% +/- 0.1%, and 3.9% +/- 0.1%. The results obtained on the 2%-COHb day and 3.9%-COHb day were compared to those on the room air day. There were 5.1% (p = 0.01) and 12.1% (p less than or equal to 0.0001) decreases in the time to development of ischemic ST-segment changes after exposures producing 2.0 and 3.9% COHb, respectively, compared to the control day. In addition, there were 4.2% (p = 0.027) and 7.1% (p = 0.002) decreases in time to the onset of angina after exposures producing 2.0 and 3.9% COHb, respectively, compared to the control day. A significant dose-response relationship was found for the individual differences in the time to ST end point and angina for the pre- versus postexposure exercise tests at the three carboxyhemoglobin levels. These findings demonstrate that low doses of CO produce significant effects on cardiac function during exercise in subjects with coronary artery disease. PMID:2040254

  17. Carbon monoxide on Jupiter and implications for atmospheric convection

    NASA Technical Reports Server (NTRS)

    Prinn, R. G.; Barshay, S. S.

    1977-01-01

    A study of the equilibrium and disequilibrium thermochemistry of the recently discovered carbon monoxide on Jupiter suggests that the presence of this gas in the visible atmosphere is a direct result of very rapid upward mixing from levels in the deep atmosphere where the temperature is about 1100 K and where carbon monoxide is thermodynamically much more stable. As a consequence the observed carbon monoxide mixing ratio is a sensitive function of the vertical eddy mixing coefficient. We infer a value for this latter coefficient which is about three to four orders of magnitude greater than that in the earth's troposphere. This result directly supports existing structural and dynamical theories implying very rapid convection in the deep Jovian atmosphere, driven by an internal heat source.

  18. Demystifying Controlling Copper Corrosion

    EPA Science Inventory

    The LCR systematically misses the highest health and corrosion risk sites for copper. Additionally, there are growing concerns for WWTP copper in sludges and discharge levels. There are many corrosion control differences between copper and lead. This talk explains the sometimes c...

  19. Demystifying Controlling Copper Corrosion

    EPA Science Inventory

    The LCR systematically misses the highest health and corrosion risk sites for copper. Additionally, there are growing concerns for WWTP copper in sludges and discharge levels. There are many corrosion control differences between copper and lead. This talk explains the sometimes c...

  20. Copper-tantalum alloy

    DOEpatents

    Schmidt, Frederick A.; Verhoeven, John D.; Gibson, Edwin D.

    1986-07-15

    A tantalum-copper alloy can be made by preparing a consumable electrode consisting of an elongated copper billet containing at least two spaced apart tantalum rods extending longitudinally the length of the billet. The electrode is placed in a dc arc furnace and melted under conditions which co-melt the copper and tantalum to form the alloy.

  1. [Copper IUDs (author's transl)].

    PubMed

    Thiery, M

    1983-10-01

    Following initial development of the Grafenberg ring in the 1920's, IUDs fell into disuse until the late 1950s, when plastic devices inserted using new technology began to gain worldwide acceptance. Further research indicated that copper had a significant antifertility effect which increased with increasing surface area, and several copper IUDs were developed and adapted, including the Copper T 200, the Copper T 220C, and the Copper T 380 A, probably the most effective yet. The Gravigard and Multiload are 2 other copper devices developed according to somewhat different principles. Copper devices are widely used not so much because of their great effectiveness as because of their suitability for nulliparous patients and their ease of insertion, which minimizes risk of uterine perforation. Records of 2584 women using Copper IUDs for 7190 women-years and 956 women using devices without copper for 6059 women-years suggest that the copper devices were associated with greater effectiveness and fewer removals for complications. Research suggests that the advantages of copper IUDs become more significant with increased duration of use. Contraindications to copper devices include allergy to copper and hepatolenticular degeneration. No carcinogenic or teratogenic effect of copper devices has been found, but further studies are needed to rule out other undesirable effects. Significant modifications of copper devices in recent years have been developed to increase their effectiveness, prolong their duration of usefulness, facilitate insertion and permit insertion during abortion or delivery. The upper limit of the surface area of copper associated with increased effectiveness appears to be between 200-300 sq mm, and at some point increases in copper exposure may provoke expulsion of the IUD. The duration of fertility inhibition of copper IUDs is usually estimated at 2-3 years, but recent research indicates that it may be 6-8 years, and some devices may retain copper surface

  2. Carbon monoxide metabolism by the photosynthetic bacterium Rhodospirillum rubrum

    SciTech Connect

    Ludden, P.W.; Roberts, G.P.

    1991-01-01

    Research continued on carbon monoxide metabolism by Rhodospirillum rubrum. In the past year, progress was made in: (1) the identification and isolation of the physiological electron carrier from monoxide dehydrogenase (CODH) to hydrogenase in R. rubrum; (2) the isolation, sequencing and mutagenesis of the genes encoding the components of the CO oxidation system in R. rubrum, (3) the purification and characterization of the CO-induced hydrogenase activity of R. rubrum; (4) the spectroscopic investigation of the cobalt-substituted form of the enzyme.

  3. The oxidation of carbon monoxide using tin oxide based catalysts

    NASA Technical Reports Server (NTRS)

    Sampson, Christopher F.; Jorgensen, Norman

    1990-01-01

    The preparation conditions for precious metal/tin oxide catalysts were optimized for maximum carbon monoxide/oxygen recombination efficiency. This was achieved by controlling the tin digestion, the peptization to form the sol, the calcination process and the method of adding the precious metals. Extensive studies of the tin oxide structure were carried out over the temperature range 20 to 500 C in air or hydrogen environments using Raman scattering and X ray diffraction. Adsorbed species on tin oxide, generated in an environment containing carbon monoxide, gave rise to a Raman band at about 1600 cm(exp -1) which was assigned to carbonaceous groups, possible carbonate.

  4. Terpolymerization of ethylene, sulfur dioxide and carbon monoxide

    DOEpatents

    Johnson, Richard; Steinberg, Meyer

    1981-01-01

    This invention relates to a high molecular weight terpolymer of ethylene, sulfur dioxide and carbon monoxide stable to 280.degree. C. and containing as little as 36 mol % ethylene and about 41-51 mol % sulfur dioxide; and to the method of producing said terpolymer by irradiation of a liquid and gaseous mixture of ethylene, sulfur dioxide and carbon monoxide by means of Co-60 gamma rays or an electron beam, at a temperature of about 10.degree.-50.degree. C., and at a pressure of about 140 to 680 atmospheres, to initiate polymerization.

  5. Terpolymerization of ethylene, sulfur dioxide and carbon monoxide

    DOEpatents

    Johnson, R.; Steinberg, M.

    This invention relates to high molecular weight terpolymer of ethylene, sulfur dioxide and carbon monoxide stable to 280/sup 0/C and containing as little as 36 mo1% ethylene and about 41 to 51 mo1% sulfur dioxide, and to the method of producing said terpolymer by irradiation of a liquid and gaseous mixture of ethylene, sulfur dioxide and carbon monoxide by means of Co-60 gamma rays or an electron beam, at a temperature of about 10 to 50/sup 0/C, and at a pressure of about 140 to 680 atmospheres, to initiate polymerization.

  6. Oxide nucleation on thin films of copper during in situ oxidation in an electron microscope

    NASA Technical Reports Server (NTRS)

    Heinemann, K.; Rao, D. B.; Douglass, D. L.

    1975-01-01

    Single-crystal copper thin films were oxidized at an isothermal temperature of 425 C and at an oxygen partial pressure of 0.005 torr. Specimens were prepared by epitaxial vapor deposition onto polished faces of rocksalt and were mounted in a hot stage inside the ultrahigh-vacuum chamber of a high-resolution electron microscope. An induction period of roughly 30 min was established which was independent of the film thickness but depended strongly on the oxygen partial pressure and to exposure to oxygen prior to oxidation. Neither stacking faults nor dislocations were found to be associated with the Cu2O nucleation sites. The experimental data, including results from oxygen dissolution experiments and from repetitive oxidation-reduction-oxidation sequences, fit well into the framework of an oxidation process involving the formation of a surface charge layer, oxygen saturation of the metal with formation of a supersaturated zone near the surface, and nucleation followed by surface diffusion of oxygen and bulk diffusion of copper for lateral and vertical oxide growth, respectively.

  7. Oxide nucleation on thin films of copper during in situ oxidation in an electron microscope

    NASA Technical Reports Server (NTRS)

    Heinemann, K.; Rao, D. B.; Douglass, D. L.

    1975-01-01

    Single-crystal copper thin films were oxidized at an isothermal temperature of 425 C and at an oxygen partial pressure of 0.005 torr. Specimens were prepared by epitaxial vapor deposition onto polished faces of rocksalt and were mounted in a hot stage inside the ultrahigh-vacuum chamber of a high-resolution electron microscope. An induction period of roughly 30 min was established which was independent of the film thickness but depended strongly on the oxygen partial pressure and to exposure to oxygen prior to oxidation. Neither stacking faults nor dislocations were found to be associated with the Cu2O nucleation sites. The experimental data, including results from oxygen dissolution experiments and from repetitive oxidation-reduction-oxidation sequences, fit well into the framework of an oxidation process involving the formation of a surface charge layer, oxygen saturation of the metal with formation of a supersaturated zone near the surface, and nucleation followed by surface diffusion of oxygen and bulk diffusion of copper for lateral and vertical oxide growth, respectively.

  8. Preferential Carbon Monoxide Oxidation over Copper-Based Catalysts under In Situ Ball Milling.

    PubMed

    Eckert, Rene; Felderhoff, Michael; Schüth, Ferdi

    2017-02-20

    In situ ball milling of solid catalysts is a promising yet almost unexplored concept for boosting catalytic performance. The continuous preferential oxidation of CO (CO-PROX) under in situ ball milling of Cu-based catalysts such as Cu/Cr2 O3 is presented. At temperatures as low as -40 °C, considerable activity and more than 95 % selectivity were achieved. A negative apparent activation energy was observed, which is attributed to the mechanically induced generation and subsequent thermal healing of short-lived surface defects. In situ ball milling at sub-zero temperatures resulted in an increase of the CO oxidation rate by roughly 4 orders of magnitude. This drastic and highly selective enhancement of CO oxidation showcases the potential of in situ ball milling in heterogeneous catalysis. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Antimicrobial applications of copper.

    PubMed

    Vincent, Marin; Hartemann, Philippe; Engels-Deutsch, Marc

    2016-10-01

    Copper has long been known to have antimicrobial activity and is used in drinking water treatment and transportation. It has been recognized by the American Environmental Protection Agency as the first metallic antimicrobial agent in 2008. With ongoing waterborne hospital-acquired infections and antibiotic resistance, research on copper as an antimicrobial agent is again very attractive. Many studies have shown that the use of copper surface and copper particles could significantly reduce the environmental bioburden. This review highlights in its first part all the conditions described in the literature to enhance copper antimicrobial activity. Secondly, the different antimicrobial applications of copper in water treatment, hospital care units and public applications are presented. Finally, the future research needs on copper as an antimicrobial agent are discussed. Copyright © 2016 Elsevier GmbH. All rights reserved.

  10. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Carbon monoxide and carbon dioxide... Test Procedures § 86.316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made with nondispersive infrared (NDIR) an analyzers. (b...

  11. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Carbon monoxide and carbon dioxide... Test Procedures § 86.316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made with nondispersive infrared (NDIR) an analyzers. (b...

  12. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Carbon monoxide and carbon dioxide... Test Procedures § 86.316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made with nondispersive infrared (NDIR) an analyzers. (b...

  13. 40 CFR 86.316-79 - Carbon monoxide and carbon dioxide analyzer specifications.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Carbon monoxide and carbon dioxide... Test Procedures § 86.316-79 Carbon monoxide and carbon dioxide analyzer specifications. (a) Carbon monoxide and carbon dioxide measurements are to be made with nondispersive infrared (NDIR) an analyzers. (b...

  14. 40 CFR 52.1627 - Control strategy and regulations: Carbon monoxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...: Carbon monoxide. 52.1627 Section 52.1627 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... § 52.1627 Control strategy and regulations: Carbon monoxide. (a) Part D Approval. The Albuquerque/Bernalillo County carbon monoxide maintenance plan as adopted on April 13, 1995, meets the requirements...

  15. 40 CFR 52.1627 - Control strategy and regulations: Carbon monoxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...: Carbon monoxide. 52.1627 Section 52.1627 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... § 52.1627 Control strategy and regulations: Carbon monoxide. (a) Part D Approval. The Albuquerque/Bernalillo County carbon monoxide maintenance plan as adopted on April 13, 1995, meets the requirements...

  16. 40 CFR 52.1627 - Control strategy and regulations: Carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...: Carbon monoxide. 52.1627 Section 52.1627 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... § 52.1627 Control strategy and regulations: Carbon monoxide. (a) Part D Approval. The Albuquerque/Bernalillo County carbon monoxide maintenance plan as adopted on April 13, 1995, meets the requirements...

  17. 40 CFR 52.1627 - Control strategy and regulations: Carbon monoxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...: Carbon monoxide. 52.1627 Section 52.1627 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... § 52.1627 Control strategy and regulations: Carbon monoxide. (a) Part D Approval. The Albuquerque/Bernalillo County carbon monoxide maintenance plan as adopted on April 13, 1995, meets the requirements...

  18. 40 CFR 52.1627 - Control strategy and regulations: Carbon monoxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...: Carbon monoxide. 52.1627 Section 52.1627 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... § 52.1627 Control strategy and regulations: Carbon monoxide. (a) Part D Approval. The Albuquerque/Bernalillo County carbon monoxide maintenance plan as adopted on April 13, 1995, meets the requirements...

  19. 40 CFR 50.8 - National primary ambient air quality standards for carbon monoxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... standards for carbon monoxide. 50.8 Section 50.8 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... ambient air quality standards for carbon monoxide. (a) The national primary ambient air quality standards for carbon monoxide are: (1) 9 parts per million (10 milligrams per cubic meter) for an 8-hour average...

  20. 40 CFR 50.8 - National primary ambient air quality standards for carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... standards for carbon monoxide. 50.8 Section 50.8 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... ambient air quality standards for carbon monoxide. (a) The national primary ambient air quality standards for carbon monoxide are: (1) 9 parts per million (10 milligrams per cubic meter) for an 8-hour average...

  1. 77 FR 8252 - Adequacy Status of the Anchorage, Alaska, Carbon Monoxide Maintenance Plan for Transportation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-14

    ... AGENCY Adequacy Status of the Anchorage, Alaska, Carbon Monoxide Maintenance Plan for Transportation... budget (MVEB) in the Anchorage, Alaska, Carbon Monoxide (CO) Maintenance Plan, submitted by the State of... monoxide Maintenance Plan for Anchorage, Alaska. EPA's finding was made pursuant to the adequacy review...

  2. Acute copper toxicity following copper glycinate injection.

    PubMed

    Oon, S; Yap, C-H; Ihle, B U

    2006-11-01

    We present a patient who developed multi-organ failure due to severe copper toxicity following attempted suicide by s.c. injection of copper glycinate. Acute copper toxicity is rare in the developed world, although it occurs more frequently in developing world countries, where it is a common mode of suicide. Acute toxicity usually results from oral ingestion and there are several local and systemic effects. Specific management can be difficult as there is little evidence regarding the efficacy of chelating agents in acute toxicity.

  3. Optical and electron transport properties of rock-salt Sc{sub 1−x}Al{sub x}N

    SciTech Connect

    Deng, Ruopeng; Zheng, P. Y.; Gall, D.

    2015-07-07

    Epitaxial single-crystal Sc{sub 1−x}Al{sub x}N ternary alloy layers deposited by magnetron co-sputtering on MgO(001) substrates at 950 °C exhibit a solid solution rock-salt phase for x = 0–0.2 without decomposition. Optical absorption indicates a linear increase in the optical gap from 2.51 eV for ScN to 3.05 eV for Sc{sub 0.8}Al{sub 0.2}N and, after correction due to the Moss-Burstein shift, a direct X point interband transition energy E{sub g}(X) = 2.15 + 2.75 x (eV). Correspondingly, the direct transition at the zone center increases with Al concentration according to E{sub g}(Γ) = 3.80 + 1.45 x (eV), as determined from a feature in the reflection spectra. All layers are degenerate n-type semiconductors with a room temperature mobility that decreases from 22 to 6.7 to 0.83 cm{sup 2}/V s as x increases from 0 to 0.11 to 0.20. The corresponding carrier densities are 9.2 × 10{sup 20}, 7.9 × 10{sup 20}, and 0.95 × 10{sup 20 }cm{sup −3} as determined from Hall measurements and consistent with optical free carrier absorption below photon energies of 1 eV. Temperature dependent transport measurements indicate metallic conduction for ScN, but weak localization that leads to a resistivity minimum at 85 and 210 K for x = 0.051 and 0.15, respectively, and a negative temperature coefficient over the entire measured 4–300 K range for Sc{sub 0.8}Al{sub 0.2}N. The decreasing mobility is attributed to alloy scattering at randomly distributed Al atoms on cation sites, which also cause the weak localization. The carrier density is primarily due to unintentional F doping from the Sc target and decreases strongly for x > 0.15, which is attributed to trapping in defect states due to the deterioration of the crystalline quality, as evidenced by the x-ray diffraction peak width that exhibits a minimum of 0.14° for x = 0.11 but increases to 0.49° for x = 0.20. This is consistent with asymmetric x

  4. Tita: discovery of carbon monoxide in its atmosphere

    NASA Technical Reports Server (NTRS)

    Lutz, B. L.; Debergh, C.; Owen, T.

    1982-01-01

    The 3-D rotation-vibration band of carbon monoxide was identified in the near-infrared spectrum of Titan. A preliminary mixing ratio of CO/N2 = 0.00006 was determined. This result supports the probable detection of CO2 by Samuelson et al and strengthens possible analogies between the atmosphere of Titan and conditions on the primitive Earth.

  5. Effect of carbon monoxide on Swiss albino mice

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Cumming, H. J.

    1977-01-01

    Times to incapacitation and death and LC50 values were determined for male Swiss albino mice exposed to different concentrations of carbon monoxide in a 4.2 liter hemispherical chamber. These values are compared to values reported in the literature. The LC50 for a 30 minute exposure was 3570 ppm CO.

  6. 40 CFR 89.320 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Emission Test Equipment Provisions § 89.320 Carbon monoxide analyzer calibration. (a) Calibrate the NDIR carbon... on the zero, concentration values may be calculated by use of a single calibration factor for that...

  7. 40 CFR 89.320 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Emission Test Equipment Provisions § 89.320 Carbon monoxide analyzer calibration. (a) Calibrate the NDIR carbon... on the zero, concentration values may be calculated by use of a single calibration factor for that...

  8. Carbon Monoxide Poisoning - Multiple Languages: MedlinePlus

    MedlinePlus

    ... on this page, please enable JavaScript. Amharic (amarunya) Arabic (العربية) Chinese - Traditional (繁體中文) French (français) German (Deutsch) ... Amharic) PDF Centers for Disease Control and Prevention Arabic (العربية) Carbon Monoxide Poisoning English (Arabic) العربية PDF ...

  9. Integrated Science Assessment for Carbon Monoxide (Second External Review Draft)

    EPA Science Inventory

    EPA has announced that the Second External Review Draft of the Integrated Science Assessment (ISA) for Carbon Monoxide (CO) and related Annexes have been made available for independent peer review and public review. This draft ISA document represents a concise synthesis and evalu...

  10. 40 CFR 86.222-94 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Carbon monoxide analyzer calibration. 86.222-94 Section 86.222-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.222-94 Carbon...

  11. 40 CFR 86.222-94 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Carbon monoxide analyzer calibration. 86.222-94 Section 86.222-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.222-94 Carbon...

  12. 40 CFR 86.222-94 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Carbon monoxide analyzer calibration. 86.222-94 Section 86.222-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.222-94 Carbon...

  13. 40 CFR 86.222-94 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Carbon monoxide analyzer calibration. 86.222-94 Section 86.222-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... New Medium-Duty Passenger Vehicles; Cold Temperature Test Procedures § 86.222-94 Carbon...

  14. 40 CFR 52.1528 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Environmental Services submitted a request to redesignate the City of Manchester carbon monoxide nonattainment... maintenance plan as required by 175A of the Clean Air Act, as amended in 1990. Elements of the section 175A... effect through the year 2020, as required by the Clean Air Act. If the area records a violation of the...

  15. 40 CFR 52.1528 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Environmental Services submitted a request to redesignate the City of Manchester carbon monoxide nonattainment... maintenance plan as required by 175A of the Clean Air Act, as amended in 1990. Elements of the section 175A... effect through the year 2020, as required by the Clean Air Act. If the area records a violation of the...

  16. 40 CFR 52.1528 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Environmental Services submitted a request to redesignate the City of Manchester carbon monoxide nonattainment... maintenance plan as required by 175A of the Clean Air Act, as amended in 1990. Elements of the section 175A... effect through the year 2020, as required by the Clean Air Act. If the area records a violation of the...

  17. 40 CFR 52.1528 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Environmental Services submitted a request to redesignate the City of Manchester carbon monoxide nonattainment... maintenance plan as required by 175A of the Clean Air Act, as amended in 1990. Elements of the section 175A... effect through the year 2020, as required by the Clean Air Act. If the area records a violation of the...

  18. Carbon monoxide detector. [electrochemical gas detector for spacecraft use

    NASA Technical Reports Server (NTRS)

    Holleck, G. L.; Bradspies, J. L.; Brummer, S. B.; Nelsen, L. L.

    1973-01-01

    A sensitive carbon monoxide detector, developed specifically for spacecraft use, is described. An instrument range of 0 to 60 ppm CO in air was devised. The fuel cell type detector is used as a highly sensitive electrolysis cell for electrochemically detecting gases. The concept of an electrochemical CO detector is discussed and the CO oxidation behavior in phosphoric and sulfuric acid electrolytes is reported.

  19. Photoproduction of Carbon Monoxide from Natural Organic Matter

    EPA Science Inventory

    Pioneering studies by Valentine provided early kinetic results that used carbon monoxide (CO) production to evaluate the photodecomposition of aquatic natural organic matter (NOM) . (ES&T 1993 27 409-412). Comparatively few kinetic studies have been conducted of the photodegradat...

  20. AIR QUALITY CRITERIA CARBON MONOXIDE, EXTERNAL REVIEW DRAFT

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) promulgates the National Ambient Air Quality Standards (NAAQS) on the basis of scientific information contained in criteria documents. The last air quality criteria document for carbon monoxide (CO) was completed by EPA in 1991. This...

  1. 40 CFR 90.317 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... carbon monoxide analyzer as described in this section. (b) Initial and periodic interference. Prior to... corrective action which may be taken.) (c) Initial and periodic calibration. Prior to its initial use and... (64 percent) is required (see following table). Example calibration points (%) Acceptable...

  2. Mechanism of Ethylene and Carbon Monoxide Production by Septoria musiva

    Treesearch

    Susan K. Brown-Skrobot; Lewis R. Brown; Ted H. Filer

    1985-01-01

    S. musiva, a causative agent of premature defoliation of cottonwood trees, has been shown previously to produce ethylene and carbon monoxide (CO) on media containing glucose, methionine, and iron. Chemical analyses have shown that all three substances are present in the cottonwood leaves. Of seven carbohydrates tested, none supported the production...

  3. 40 CFR 90.317 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... carbon monoxide analyzer as described in this section. (b) Initial and periodic interference. Prior to... corrective action which may be taken.) (c) Initial and periodic calibration. Prior to its initial use and... (64 percent) is required (see following table). Example calibration points (%) Acceptable for...

  4. 40 CFR 90.317 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... carbon monoxide analyzer as described in this section. (b) Initial and periodic interference. Prior to... corrective action which may be taken.) (c) Initial and periodic calibration. Prior to its initial use and... (64 percent) is required (see following table). Example calibration points (%) Acceptable for...

  5. 40 CFR 86.1322-84 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (CONTINUED) Emission Regulations for New Otto-Cycle and Diesel Heavy-Duty Engines; Gaseous and Particulate... be used. (2) Zero the carbon monoxide analyzer with either zero-grade air or zero-grade nitrogen. (3... either zero-grade air or zero-grade nitrogen. (3) Calibrate on each used operating range with a...

  6. 40 CFR 86.1322-84 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) Emission Regulations for New Otto-Cycle and Diesel Heavy-Duty Engines; Gaseous and Particulate... be used. (2) Zero the carbon monoxide analyzer with either zero-grade air or zero-grade nitrogen. (3... either zero-grade air or zero-grade nitrogen. (3) Calibrate on each used operating range with a...

  7. 40 CFR 86.1322-84 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) Emission Regulations for New Otto-Cycle and Diesel Heavy-Duty Engines; Gaseous and Particulate... be used. (2) Zero the carbon monoxide analyzer with either zero-grade air or zero-grade nitrogen. (3... either zero-grade air or zero-grade nitrogen. (3) Calibrate on each used operating range with a...

  8. 40 CFR 86.1522 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 19 2011-07-01 2011-07-01 false Carbon monoxide analyzer calibration...) Emission Regulations for Otto-Cycle Heavy-Duty Engines, New Methanol-Fueled Natural Gas-Fueled, and Liquefied Petroleum Gas-Fueled Diesel-Cycle Heavy-Duty Engines, New Otto-Cycle Light-Duty Trucks, and...

  9. 40 CFR 86.1522 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 20 2012-07-01 2012-07-01 false Carbon monoxide analyzer calibration...) Emission Regulations for Otto-Cycle Heavy-Duty Engines, New Methanol-Fueled Natural Gas-Fueled, and Liquefied Petroleum Gas-Fueled Diesel-Cycle Heavy-Duty Engines, New Otto-Cycle Light-Duty Trucks, and...

  10. 40 CFR 86.1522 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 20 2013-07-01 2013-07-01 false Carbon monoxide analyzer calibration...) Emission Regulations for Otto-Cycle Heavy-Duty Engines, New Methanol-Fueled Natural Gas-Fueled, and Liquefied Petroleum Gas-Fueled Diesel-Cycle Heavy-Duty Engines, New Otto-Cycle Light-Duty Trucks, and...

  11. 40 CFR 86.1522 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Carbon monoxide analyzer calibration...) Emission Regulations for Otto-Cycle Heavy-Duty Engines, New Methanol-Fueled Natural Gas-Fueled, and Liquefied Petroleum Gas-Fueled Diesel-Cycle Heavy-Duty Engines, New Otto-Cycle Light-Duty Trucks, and...

  12. 40 CFR 86.1522 - Carbon monoxide analyzer calibration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Carbon monoxide analyzer calibration... Regulations for Otto-Cycle Heavy-Duty Engines, New Methanol-Fueled Natural Gas-Fueled, and Liquefied Petroleum Gas-Fueled Diesel-Cycle Heavy-Duty Engines, New Otto-Cycle Light-Duty Trucks, and New...

  13. Photoproduction of Carbon Monoxide from Natural Organic Matter

    EPA Science Inventory

    Pioneering studies by Valentine provided early kinetic results that used carbon monoxide (CO) production to evaluate the photodecomposition of aquatic natural organic matter (NOM) . (ES&T 1993 27 409-412). Comparatively few kinetic studies have been conducted of the photodegradat...

  14. Carbon Monoxide Isotopes: On the Trail of Galactic Chemical Evolution

    NASA Technical Reports Server (NTRS)

    Langer, W.

    1995-01-01

    From the early days of the discovery of radio emission from carbon monoxide it was realized that it offered unusual potential for under- standing the chemical evolution of the Galaxy and external galaxies through measurements of molecular isotopes. These results bear on stellar nucleosynthesis, star formation, and gases in the interstellar medium. Progress in isotopic radio measurements will be reviewed.

  15. Production of Ethylene and Carbon Monoxide by Microorganisms

    Treesearch

    T. H. Filer; L. R. Brown; S. Brown-Sarobot; S. Martin

    1984-01-01

    Various quantities of ethylene and carbon monoxide were produced on PDA by Fusicladium effusum, Pestilotia nucicola, Alternaria tenuis, and Fusarium oxysporum subcultured from diseased pecan shucks. Repeated subculturing of these fungi on potato dextrose broth supplemented with iron powder produced ethylene. The production of...

  16. Measurements of carbon monoxide from space using the MOPITT instrument

    NASA Astrophysics Data System (ADS)

    Drummond, J.; Kar, J.; Liu, J.; Zou, J.; Nichitiu, F.; Edwards, D.; Gille, J.

    The Measurements Of Pollution in The Troposphere MOPITT instrument was launched on December 19 th 1999 and has now completed over six years of measurements of carbon monoxide from space providing the most extensive and complete data set of a tropospheric minor constituent over the planet in both space and time During the mission -- which is still continuing -- events have been observed at many time and space scales ranging from planetary-scale changes from extensive forest fires persisting for many months to sharp concentration changes over 100km persisting only for a few days This wealth of phenomena has given us a new view of the troposphere and its chemical and dynamical behavior With such an extensive dataset it is now possible to try to assess the average behaviour of carbon monoxide over the planet The intriguing result is that the average proves very elusive and the typical year has yet to be determined Random surface events are frequent enough that carbon monoxide is frequently perturbed from its background state This has implications for modeling and forecasting of future concentrations This paper will highlight some of the events that perturb the carbon monoxide concentration drawing from examples over the MOPITT mission time frame and discuss how these feed into the global picture We will also discuss what implications this has for future missions to continue the dataset The MOPITT instrument has been supported by the Canadian Space Agency MOPITT data processing is supported by NASA MOPITT data analysis has

  17. Some usual and unusual poisonings due to carbon monoxide.

    PubMed

    Kaye, Sidney

    2003-01-01

    Carbon monoxide poisoning is a frequent occurrence in both developed and under developed countries of the world. Carbon monoxide can be produced in fires, automobile engine exhausts and the incomplete combustion of organic matter. It is a "silent killer" that initially produces a mild progressive frontal headache, drowsiness and sleep that is usually ignored as common place. Continued low-level CO exposure for a long period of time in a confined space is cumulative and these accidental deaths are frequent but should be avoidable. Several usual and unusual poisonings are reported to illustrate its various forms of exposure. It all began many years ago when a bolt of lightening hit a fallen tree and produced a fire. Early cave man later learned to enjoy some of the benefits of this new discovery. They could now see at night, they could keep warm, keep the predators at bay, cook their food and make it taste better and be more gentle to their teeth. Also meat could be preserved and eaten at a later date especially if it were dried and smoked. They learned by trial and error that it was dangerous to bring their fire deep into their cave without a chimney. Carbon monoxide (CO) also can be easily produced by many other sources besides fire. Very common today is the incomplete combustion of gasoline in the engine of an automobile which can produce about 6% carbon monoxide.

  18. AIR QUALITY CRITERIA CARBON MONOXIDE, EXTERNAL REVIEW DRAFT

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) promulgates the National Ambient Air Quality Standards (NAAQS) on the basis of scientific information contained in criteria documents. The last air quality criteria document for carbon monoxide (CO) was completed by EPA in 1991. This...

  19. Removal of phosphine contaminant from carbon monoxide gas mixtures

    SciTech Connect

    Goldstein, D.; Munday, T.F.; Walden, J.

    1980-01-22

    A method is claimed for removing small concentrations of phosphine contained in a carbon monoxide gas mixture by preferentially oxidizing the phosphine, in which the phosphine is oxidized with air at a temperature of from 500 to 800 to form phosphorus pentoxide, which is recovered from the gas mixture preferably as phosphoric acid.

  20. Integrated Science Assessment for Carbon Monoxide (First External Review Draft)

    EPA Science Inventory

    EPA has announced that the First External Review Draft of the Integrated Science Assessment (ISA) for Carbon Monoxide (CO) and related Annexes have been made available for independent peer review and public review. This draft ISA document represents a concise synthesis and evalua...

  1. Carbon Monoxide Isotopes: On the Trail of Galactic Chemical Evolution

    NASA Technical Reports Server (NTRS)

    Langer, W.

    1995-01-01

    From the early days of the discovery of radio emission from carbon monoxide it was realized that it offered unusual potential for under- standing the chemical evolution of the Galaxy and external galaxies through measurements of molecular isotopes. These results bear on stellar nucleosynthesis, star formation, and gases in the interstellar medium. Progress in isotopic radio measurements will be reviewed.

  2. CARBON MONOXIDE POISONING--A PUBLIC HEALTH PERSPECTIVE.

    EPA Science Inventory

    Carbon monoxide (CO) may be the cause of more than one-half of the fatal poisonings reported in many countries: fatal cases also are grossly under-reported or mis-diagnosed by medical professionals. Therefore, the precise number of individuals who have suffered from CO intoxicat...

  3. Poisoning by carbon monoxide in Morocco from 1991 to 2008.

    PubMed

    Aghandous, Rachida; Chaoui, Hanane; Rhalem, Naima; Semllali, Ilham; Badri, Mohamed; Soulaymani, Abdelmajid; Ouammi, Lahcen; Soulaymani-Bencheikh, Rachida

    2012-04-01

    To describe the characteristics relating to the provenance of statements, patients and to evaluate the spatiotemporal evolution of carbon monoxide poisoning reported to Poison Control Center and Pharmacovigilance of Morocco (CAPM). This is a retrospective study over a period of 18 years from 1991 to 2008, for all cases of poisoning by carbon monoxide reported to CAPM. The epidemiological study focused on 12 976 cases of carbon monoxide poisoning reported to CAPM between 1991 and 2008. The average age of patients was 25.5 +/- 15.6 years, sex ratio was 0.5. The poisoning occurred by accident in 98.7% of cases, especially at home (96.7%) and in cold months. The urban population was the most affected (89.0%). The region of Meknes Tafilalt was the most concerned with 16.6% of cases. The symptomatology was characterized by the predominance of gastrointestinal tract diseases (37.1%). Deaths have reached a percentage of 0.9%. These qualitative and quantitative information is useful to highlight warnings and plan a strategy against carbon monoxide poisoning in Morocco.

  4. 2010 Final Assessment: Integrated Science Assessment for Carbon Monoxide

    EPA Science Inventory

    EPA released the final Integrated Science Assessment (ISA) for Carbon Monoxide (CO). This is EPA’s latest evaluation of the scientific literature on the potential human health and welfare effects associated with ambient exposures to CO. The development of this document i...

  5. CARBON MONOXIDE POISONING--A PUBLIC HEALTH PERSPECTIVE.

    EPA Science Inventory

    Carbon monoxide (CO) may be the cause of more than one-half of the fatal poisonings reported in many countries: fatal cases also are grossly under-reported or mis-diagnosed by medical professionals. Therefore, the precise number of individuals who have suffered from CO intoxicat...

  6. Cross Sections for Electron Collisions with Carbon Monoxide

    SciTech Connect

    Itikawa, Yukikazu

    2015-03-15

    Cross section data are collected and reviewed for electron collisions with carbon monoxide. Collision processes included are total scattering, elastic scattering, momentum transfer, excitations of rotational, vibrational and electronic states, ionization, and dissociation. For each process, recommended values of the cross sections are presented, when possible. The literature has been surveyed through to the end of 2013.

  7. School Bus Carbon Monoxide Intrusion. NHTSA Technical Report.

    ERIC Educational Resources Information Center

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    This report presents the findings of a voluntary program conducted over a 10-month period during which school buses were tested for carbon monoxide (CO) levels under different climatological conditions. The objective of the test program was to determine whether or not there are any serious CO intrusion problems or indications of potential problems…

  8. 2010 Final Assessment: Integrated Science Assessment for Carbon Monoxide

    EPA Science Inventory

    Cover of the Integrated Science Assessment (ISA) for Carbon <span class=Monoxide" vspace = "5" hspace="5" align="right" border="1" /> EPA has released the final Integrated Science Assessment (ISA) for ...

  9. 40 CFR 52.349 - Control strategy: Carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... and Maintenance Plan for Greeley, as adopted by the Colorado Air Quality Control Commission on... Plan, Carbon Monoxide Redesignation Request and Maintenance Plan for Colorado Springs, as adopted by... Longmont, as adopted by the Colorado Air Quality Control Commission on December 18, 1997, State effective...

  10. Ethylene and Carbon Monoxide Production by Septoria musiva

    Treesearch

    S. Brown-Skrobot; L. R. Brown; T. H. Filer

    1984-01-01

    An investigation into the mechanism by which Septoria musiva causes the premature defoliation of cottonwood trees was undertaken. Gas-chromatograpic analysis of the atmosphere overlying the original culture indicated that this fungus produced significant quantities of ethylene and carbon monoxide. Subcultures failed to produce either gas on a variety...

  11. Copper in developmental stuttering.

    PubMed

    Alm, Per A

    2005-01-01

    It has previously been reported that men with developmental stuttering showed reduced concentration of copper in the blood, and a negative correlation between the copper level and the severity of stuttering. Disorders of copper metabolism may result in dysfunction of the basal ganglia system and dystonia, a motor disorder sharing some traits of stuttering. It has been shown that copper ions affect the dopamine and the GABA systems. With this background we investigated the plasma level of copper, the copper binding protein ceruloplasmin, and the estimated level of free copper in stuttering adults. Sixteen men with developmental stuttering were compared with 16 men without speech problems. The samples were assayed in one batch in a pseudorandom and counterbalanced order. No significant differences were found between stuttering men and the control group in any of the biological variables, and no negative correlation between copper and the general severity of stuttering was shown. On the contrary, an explorative analysis resulted in a positive correlation between high plasma copper and superfluous muscular activity during stuttering (r=0.51, p=0.04). This result indicates that there is no relation between developmental stuttering and low plasma copper in the main population of stuttering adults.

  12. Handling of Copper and Copper Oxide Nanoparticles by Astrocytes.

    PubMed

    Bulcke, Felix; Dringen, Ralf

    2016-02-01

    Copper is an essential trace element for many important cellular functions. However, excess of copper can impair cellular functions by copper-induced oxidative stress. In brain, astrocytes are considered to play a prominent role in the copper homeostasis. In this short review we summarise the current knowledge on the molecular mechanisms which are involved in the handling of copper by astrocytes. Cultured astrocytes efficiently take up copper ions predominantly by the copper transporter Ctr1 and the divalent metal transporter DMT1. In addition, copper oxide nanoparticles are rapidly accumulated by astrocytes via endocytosis. Cultured astrocytes tolerate moderate increases in intracellular copper contents very well. However, if a given threshold of cellular copper content is exceeded after exposure to copper, accelerated production of reactive oxygen species and compromised cell viability are observed. Upon exposure to sub-toxic concentrations of copper ions or copper oxide nanoparticles, astrocytes increase their copper storage capacity by upregulating the cellular contents of glutathione and metallothioneins. In addition, cultured astrocytes have the capacity to export copper ions which is likely to involve the copper ATPase 7A. The ability of astrocytes to efficiently accumulate, store and export copper ions suggests that astrocytes have a key role in the distribution of copper in brain. Impairment of this astrocytic function may be involved in diseases which are connected with disturbances in brain copper metabolism.

  13. Nitrogen monoxide and carbon monoxide transfer interpretation: state of the art.

    PubMed

    Martinot, Jean Benoit; Guénard, Hervé; Dinh-Xuan, Anh-Tuan; Gin, Henri; Dromer, Claire

    2015-11-17

    Just a few clinicians routinely measure the subcomponents of the lung diffusing capacity for Carbone monoxide (DLCO ). This is because the measurement of membrane and blood conductances for CO (DmCO and DbCO  = θCO  × Vc , respectively) by the classic Roughton and Forster method is complicated and time consuming. In addition, it mistakenly assumes a close relationship between alveolar oxygen partial pressure (PAO2 ) and mean intracapillary oxygen partial pressure (PcapO2 ) which is the true determinant of specific conductance of haemoglobin for CO (θCO ). Besides that, the critical multistep oxygenation method along with different linear equations relating 1/θCO to PcapO2 gave highly scattered DmCO and Vc values. The Dm and Vc can also be derived from a simultaneous measurement of DLNO and DLCO with the blood resistance for NO assumed to be negligible. However, recent in vitro and in vivo experiments point towards a finite value of θNO (about 4·5 mlNO  × mlblood(-1)  × min(-1)  × mmHg(-1) ). Putting together the arguments and our clinical data allows us to report here the state of the art in partitioning the CO diffusing capacity into its constitutive components, with the goal to encourage further studies examining the sensitivity of DmCO and Vc to alterations observed in parenchymal diseases.

  14. Biological signaling by carbon monoxide and carbon monoxide-releasing molecules.

    PubMed

    Motterlini, Roberto; Foresti, Roberta

    2017-03-01

    Carbon monoxide (CO) is continuously produced in mammalian cells during the degradation of heme. It is a stable gaseous molecule that reacts selectively with transition metals in a specific redox state, and these characteristics restrict the interaction of CO with defined biological targets that transduce its signaling activity. Because of the high affinity of CO for ferrous heme, these targets can be grouped into heme-containing proteins, representing a large variety of sensors and enzymes with a series of diverse function in the cell and the organism. Despite this notion, progress in identifying which of these targets are selective for CO has been slow and even the significance of elevated carbonmonoxy hemoglobin, a classical marker used to diagnose CO poisoning, is not well understood. This is also due to the lack of technologies capable of assessing in a comprehensive fashion the distribution and local levels of CO between the blood circulation, the tissue, and the mitochondria, one of the cellular compartments where CO exerts its signaling or detrimental effects. Nevertheless, the use of CO gas and CO-releasing molecules as pharmacological approaches in models of disease has provided new important information about the signaling properties of CO. In this review we will analyze the most salient effects of CO in biology and discuss how the binding of CO with key ferrous hemoproteins serves as a posttranslational modification that regulates important processes as diverse as aerobic metabolism, oxidative stress, and mitochondrial bioenergetics. Copyright © 2017 the American Physiological Society.

  15. Carbon monoxide rich methanation kinetics on supported rhodium and nickel catalysts. Final report

    SciTech Connect

    Keehan, D.

    1988-08-01

    The utilization of carbon dioxide reforming of methane in a solar-based Chemical Energy Transmission System (CETS) relies greatly upon the development of suitable catalysts for both the endothermic and exothermic reactions. Carbon dioxide reforming of methane produces hydrogen and carbon monoxide at a ratio of about one, thus requiring the methanation reaction on the other side of the closed loop CETS to utilize this feed. H/sub 2//CO ratios lower than three favor the formation of carbon with industrial methanation catalysts. Preliminary tests performed on methanation with rhodium and nickel catalysts produced two, 0.5% Rh/A1/sub 2/O/sub 3/ and Ni/A1/sub 2/O/sub 3/, for further study. Kinetic experiments were conducted in an isothermal continuous stirred tank reactor constructed of a copper alloy which prevented carbon formation on reactor parts. These experiments were performed on pelleted 0.5% Rh/A1/sub 2/O/sub 3/ in the 400 to 500 C range and pelleted 70% Ni/A1/sub 2/O/sub 3/ in the 300 to 500 C temperature range. In most experiments steam was added to the reactor feed to inhibit carbon formation.

  16. Copper-Silicon Bronzes

    DTIC Science & Technology

    1933-05-11

    copper alloys which have good static properties are disa:cinting in their endurance properties. The silicide allo~rs that are given high tensile strength...notched endurance tests and on cast alloys of this type, are lacking. uowever, preliminary reports state that a copper beryllium alloy of about 2 1/2...properties re- main almost the same. Grain size increases with sil- icon. III A study of hardening copper by heat treating its alloys with silicides

  17. Hair copper in intrauterine copper device users.

    PubMed

    Thiery, M; Heyndrickx, A; Uyttersprot, C

    1984-03-01

    The antifertility effect of copper-bearing IUDs is based on continuous release of copper, which is a result of the reaction between the metal and the uterine secretions. Released cupric ions collect in the endometrium and in the uterine fluid but significant accumulation has not been found in the bloodstream or elsewhere. Following Laker's suggestion that hair be used for monitoring essential trace elements, e.g., copper, we checked the copper content of the hair of women wearing copper-bearing IUDs. Samples of untreated pubic hair removed by clipping before diagnostic curettage were obtained from 10 young (24-34 years old), white caucasian females who until then had been wearing an MLCu250 IUD for more than 1 year. Pubes from 10 comparable (sex, age, race) subjects who had never used a Cu-containing device served as controls. The unwashed material was submitted to the toxicology laboratory, where the copper content was assessed by flameless atomic absorption, a technique whose lower limit of measurement lies at a concentration of 0.05 mcg Cu/ml fluid (50 ppb). Hair samples were washed to remove extraneous traces of metal according to the prescriptions of the International Atomic Energy Agency, weighed, and mineralized, after which a small volume (10 mcl) of the diluted fluid was fed into the graphite furnace. Each sample (75-150 mg) was analyzed 4 times, both before and after washing. Since the cleaning procedure reduces the weight of the sample (mainly by the removal of fat, dust, etc.) this explains why the percentage copper content of washed hair is higher than that of unwashed hair belonging to the same subject. The results indicate that there was no significant difference (Mann-Whitney U test) between the mean copper levels of both unwashed and washed pubes from women who were using or had never used an MLCu250 IUD. We therefore conclude that the use of this copper-containing device is not associated with significant accumulation of copper in (pubic) hair.

  18. High adherence copper plating process

    DOEpatents

    Nignardot, Henry

    1993-01-01

    A process for applying copper to a substrate of aluminum or steel by electrodeposition and for preparing an aluminum or steel substrate for electrodeposition of copper. Practice of the invention provides good adhesion of the copper layer to the substrate.

  19. Biogenic nanoparticles: copper, copper oxides, copper sulphides, complex copper nanostructures and their applications.

    PubMed

    Rubilar, Olga; Rai, Mahendra; Tortella, Gonzalo; Diez, Maria Cristina; Seabra, Amedea B; Durán, Nelson

    2013-09-01

    Copper nanoparticles have been the focus of intensive study due to their potential applications in diverse fields including biomedicine, electronics, and optics. Copper-based nanostructured materials have been used in conductive films, lubrification, nanofluids, catalysis, and also as potent antimicrobial agent. The biogenic synthesis of metallic nanostructured nanoparticles is considered to be a green and eco-friendly technology since neither harmful chemicals nor high temperatures are involved in the process. The present review discusses the synthesis of copper nanostructured nanoparticles by bacteria, fungi, and plant extracts, showing that biogenic synthesis is an economically feasible, simple and non-polluting process. Applications for biogenic copper nanoparticles are also discussed.

  20. Multiphase separation of copper nanowires.

    PubMed

    Qian, Fang; Lan, Pui Ching; Olson, Tammy; Zhu, Cheng; Duoss, Eric B; Spadaccini, Christopher M; Han, T Yong-Jin

    2016-09-22

    This communication reports a new method to purify copper nanowires with nearly 100% yield from undesired copper nanoparticle side-products formed during batch processes of copper nanowire synthesis. This simple separation method can yield large quantities of long, uniform, high-purity copper nanowires to meet the requirements of nanoelectronics applications as well as provide an avenue for purifying copper nanowires in the industrial scale synthesis of copper nanowires, a key step for commercialization and application of nanowires.

  1. Multiphase separation of copper nanowires

    DOE PAGES

    Qian, Fang; Lan, Pui Ching; Olson, Tammy; ...

    2016-01-01

    This communication reports a new method to purify copper nanowires with nearly 100% yield from undesired copper nanoparticle side-products formed during batch processes of copper nanowire synthesis. This simple separation method can yield large quantities of long, uniform, high-purity copper nanowires to meet the requirements of nanoelectronics applications as well as provide an avenue for purifying copper nanowires in the industrial scale synthesis of copper nanowires, a key step for commercialization and application of nanowires.

  2. Multiphase separation of copper nanowires

    SciTech Connect

    Qian, Fang; Lan, Pui Ching; Olson, Tammy; Zhu, Cheng; Duoss, Eric B.; Spadaccini, Christopher M.; Han, T. Yong-Jin

    2016-09-01

    Here, this communication reports a new method to purify copper nanowires with nearly 100% yield from undesired copper nanoparticle side-products formed during batch processes of copper nanowire synthesis. Also, this simple separation method can yield large quantities of long, uniform, high-purity copper nanowires to meet the requirements of nanoelectronics applications as well as provide an avenue for purifying copper nanowires in the industrial scale synthesis of copper nanowires, a key step for commercialization and application of nanowires.

  3. Copper-containing zeolite catalysts

    DOEpatents

    Price, G.L.; Kanazirev, V.

    1996-12-10

    A catalyst useful in the conversion of nitrogen oxides or in the synthesis of nitriles or imines from amines, is formed by preparing an intimate mechanical mixture of a copper (II)-containing species, such as CuO or CuCl{sub 2}, or elemental copper, with a zeolite having a pore mouth comprising 10 oxygen atoms, such as ZSM-5, converting the elemental copper or copper (II) to copper (I), and driving the copper (I) into the zeolite.

  4. Copper-containing zeolite catalysts

    SciTech Connect

    Price, Geoffrey L.; Kanazirev, Vladislav

    1996-01-01

    A catalyst useful in the conversion of nitrogen oxides or in the synthesis of nitriles or imines from amines, formed by preparing an intimate mechanical mixture of a copper (II)-containing species, such as CuO or CuCl.sub.2, or elemental copper, with a zeolite having a pore mouth comprising 10 oxygen atoms, such as ZSM-5, converting the elemental copper or copper (II) to copper (I), and driving the copper (I) into the zeolite.

  5. Copper Delivery by Metallochaperone Proteins

    SciTech Connect

    Rosenzweig, A.C.

    2010-03-08

    Copper is an essential element in all living organisms, serving as a cofactor for many important proteins and enzymes. Metallochaperone proteins deliver copper ions to specific physiological partners by direct protein-protein interactions. The Atx1-like chaperones transfer copper to intracellular copper transporters, and the CCS chaperones shuttle copper to copper,zinc superoxide dismutase. Crystallographic studies of these two copper chaperone families have provided insights into metal binding and target recognition by metallochaperones and have led to detailed molecular models for the copper transfer mechanism.

  6. Carbon monoxide sensors. January 1970-April 1989 (Citations from the COMPENDEX data base). Report for January 1970-April 1989

    SciTech Connect

    Not Available

    1989-04-01

    This bibliography contains citations concerning the measurement and sensing of carbon monoxide. Carbon monoxide sensors used to prevent asphyxiation, combustion, and explosion are discussed. Carbon monoxide sensors used to measure combustion efficiency and gas levels in the atmosphere are included. Designs for gas sensors that measure several gases or carbon monoxide alone are presented. Extraterrestrial applications of carbon monoxide sensors are excluded. (Contains 140 citations fully indexed and including a title list.)

  7. Improved Electroformed Structural Copper and Copper Alloys

    NASA Technical Reports Server (NTRS)

    Malone, G. A.; Hudson, W.; Babcock, B.; Edwards, R.

    1998-01-01

    Electroforming offers a superior means for fabricating internally cooled heat exchangers and structures subjected to thermal environments. Copper is deposited from many such applications because of the good thermal conductivity. It suffers from mediocre yield strength as a structural material and loses mechanical strength at intermediate temperatures. Mechanical properties similar to those of electroformed nickel are desired. Phase 1 examined innovative means to improve deposited copper structural performance. Yield strengths as high as 483 MPa (70 ksi) were obtained with useful ductility while retaining a high level of purity essential to good thermal conductivity. Phase 2 represents a program to explore new additive combinations in copper electrolytes to produce a more fine, equiaxed grain which can be thermally stabilized by other techniques such as alloying in modest degrees and dispersion strengthening. Evaluation of new technology - such as the codeposition of fullerness (diamond-like) particles were made to enhance thermal conductivity in low alloys. A test fire quality tube-bundle engine was fabricated using these copper property improvement concepts to show the superiority of the new coppers and fabrications methods over competitive technologies such as brazing and plasma deposition.

  8. Carbon monoxide poisoning during natural disasters: the Hurricane Rita experience.

    PubMed

    Cukor, Jeffrey; Restuccia, Marc

    2007-10-01

    We report the incidence and mechanisms of carbon monoxide exposure during the first 5 days after Hurricane Rita, as experienced by a Disaster Medical Assistance Team staffing the only open health care facility in the Beaumont, Texas region after the storm. Improper placement of portable generators in indoor locations or proximate to home air conditioning intake systems were completely responsible for the 21 exposures including 5 fatalities, 1 brain dead, 2 transfers for hospitalization, and 13 treated and released. We discuss the clinical presentations and treatment approaches, provide a brief overview of carbon monoxide and offer novel preventive recommendations. Portable generator use after disasters represents a predictable risk to the public. Proper ventilation requirements for generators are not adequately appreciated and engineered safeties should be explored to mitigate illness.

  9. Retrograde amnesia following carbon monoxide poisoning: a case report.

    PubMed

    Acland, Peter R; Heaver, Catriona

    2008-07-01

    Retrograde amnesia is a recognised neurological complication of carbon monoxide poisoning. This article describes the case of a female found dead in her bath where initial post-mortem findings and the surrounding circumstances raised strong suspicions of homicide, especially when there was contradictory evidence from her husband who was the only other person present. He was later diagnosed as having retrograde amnesia between his two visits to the bathroom to attend to his wife which caused him to merge them into one event, thus arousing suspicions of foul play. The discussion explores the current clinical views on non-fatal carbon monoxide poisoning as well as problems of interpretation of information derived from case work.

  10. Effect of carbon monoxide and nitrogen dioxide on ICR mice

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Cumming, H. J.

    1977-01-01

    Times to incapacitation and death and LC(50) values were determined for male ICR mice exposed to different concentration of carbon monoxide for 30 min and of nitrogen dioxide for 10 min in a 4.2 liter hemispherical chamber. The data indicate that ICR mice are more resistant to these two toxicants than Swiss albino mice. The carbon monoxide LC(50) for a 30-min exposure was about 8,000 ppm for ICR mice compared to 3,570 ppm for Swiss albino mice. The nitrogen dioxide LC(50) for a 10-min exposure was above 2,000 ppm for ICR mice compared to about 1,000 ppm for Swiss albino mice.

  11. Measurement of Strontium Monoxide in Methane-Air Flames.

    PubMed

    Wimberly, Bobby J; Hornkohl, James O; Parigger, Christian G

    2017-02-01

    The spectroscopy of alkaline earth metal compounds is stimulated by the use of these compounds in practical areas ranging from technology to medicine. Applications in the field of pyrotechnics were the motivation for a series of flame emission spectroscopy experiments with strontium-containing compounds. Specifically, strontium monoxide (SrO) was studied as a candidate radiator for the diagnosis of methane-air flames. Strontium monoxide emissions have been observed in flames with temperatures in the range 1200 K to 1600 K for two compounds: strontium hydroxide and strontium chloride. Comparisons are made of the measured SrO spectra to simulated spectra in the near-infrared region of 700 nm to 900 nm.

  12. Exergy parametric study of carbon monoxide oxidation in moist air

    NASA Astrophysics Data System (ADS)

    Souidi, Ferhat; Benmalek, Toufik; Yesaad, Billel; Baik, Mouloud

    2015-12-01

    This study aims to analyze the oxidation of carbon monoxide in moist air from the second thermodynamic law aspect. A mathematical model of laminar premixed flame in a stagnation point flow has been achieved by numerical solution of the boundary layer equation using a self-made code. The chemical kinetic mechanism for flameless combustion of fuel, which is a mixture of carbon monoxide, oxygen, and water vapor, is modeled by 34 elementary reactions that incorporate (09) nine chemical species: CO, O, CO2, O2, H2O, H, H2, HO2, and OH. The salient point is that for all the parameters we considered, the exergy of the process is completely destroyed by irreversibilities. From the chemical viewpoint, the OH radical plays an essential role in CO oxidation. This latter point has already been mentioned by previous investigators.

  13. Catalysis of carbon monoxide methanation by deep sea manganate minerals

    NASA Technical Reports Server (NTRS)

    Cabrera, A. L.; Maple, M. B.; Arrhenius, G.

    1990-01-01

    The catalytic activity of deep sea manganese nodule minerals for the methanation of carbon monoxide was measured with a microcatalytic technique between 200 and 460 degrees C. The manganate minerals were activated at 248 degrees C by immersion into a stream of hydrogen in which pulses of carbon monoxide were injected. Activation energies for the methanation reaction and hydrogen desorption from the manganate minerals were obtained and compared with those of pure nickel. Similar energy values indicate that the activity of the nodule materials for the reaction appears to be related to the amount of reducible transition metals present in the samples (ca. 11 wt.-%). Since the activity of the nodule minerals per gram is comparable to that of pure nickel, most of the transition metal ions located between manganese oxide layers appear to be exposed and available to catalyze the reaction.

  14. Catalyst for the methanation of carbon monoxide in sour gas

    DOEpatents

    Kustes, William A.; Hausberger, Arthur L.

    1985-01-01

    The invention involves the synergistic effect of the specific catalytic constituents on a specific series of carriers for the methanation of carbon monoxide in the presence of sulfur at relatively high temperatures and at low steam to gas ratios in the range of 0.2:1 or less. This effect was obtained with catalysts comprising the mixed sulfides and oxides of nickel and chromium supported on carriers comprising magnesium aluminate and magnesium silicate. Conversion of carbon monoxide to methane was in the range of from 40 to 80%. Tests of this combination of metal oxides and sulfides on other carriers and tests of other metal oxides and sulfides on the same carrier produced a much lower level of conversion.

  15. Ab initio simulations of liquid carbon monoxide at high pressure

    NASA Astrophysics Data System (ADS)

    Leonhardi, Tanis C.; Militzer, Burkhard

    2017-03-01

    Carbon monoxide occurs as a volatile species in the interiors of terrestrial planets, and as a disequilibrium atmospheric constituent in the giant planets. It plays an important role during the accretionary stages of planet formation reacting with gases to form compounds such as CH4 and H2O. The structure of carbon monoxide is unknown over the majority of the temperature and pressure regime in giant planet interiors. Here we perform ab initio molecular dynamics simulations to characterize CO to 140 GPa and 5,000 K. We find that CO is stable as a molecular liquid at lower P-T conditions, as a polymeric liquid at higher P-T conditions found in ice giant interiors, and as a plasma at high-T.

  16. Effect of carbon monoxide and nitrogen dioxide on ICR mice

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Cumming, H. J.

    1977-01-01

    Times to incapacitation and death and LC(50) values were determined for male ICR mice exposed to different concentration of carbon monoxide for 30 min and of nitrogen dioxide for 10 min in a 4.2 liter hemispherical chamber. The data indicate that ICR mice are more resistant to these two toxicants than Swiss albino mice. The carbon monoxide LC(50) for a 30-min exposure was about 8,000 ppm for ICR mice compared to 3,570 ppm for Swiss albino mice. The nitrogen dioxide LC(50) for a 10-min exposure was above 2,000 ppm for ICR mice compared to about 1,000 ppm for Swiss albino mice.

  17. Diffusing capacity and anatomic dead space for carbon-18 monoxide.

    NASA Technical Reports Server (NTRS)

    Wagner, P. D.; Mazzone, R. W.; West, J. B.

    1971-01-01

    Carbon monoxide (CO) is difficult to measure with a respiratory mass spectrometer because of the similar mass numbers of CO and nitrogen, but this is possible using carbon-18 monoxide. The mass resolution, signal-to-noise ratio, linearity, and background were all found to be adequate. The measurement of the single-breath diffusing capacity was examined. Unless the mean alveolar volume during breath holding is used in the calculation, the value for Dco obtained depends on which portion of the alveolar sample is analyzed. The anatomic dead space for CO was found to be almost the same as that for argon suggesting that the diffusion rate at the dead space-alveolar gas interface was not greatly affected by the alveolar concentration of the gas.

  18. Catalysis of carbon monoxide methanation by deep sea manganate minerals

    NASA Technical Reports Server (NTRS)

    Cabrera, A. L.; Maple, M. B.; Arrhenius, G.

    1990-01-01

    The catalytic activity of deep sea manganese nodule minerals for the methanation of carbon monoxide was measured with a microcatalytic technique between 200 and 460 degrees C. The manganate minerals were activated at 248 degrees C by immersion into a stream of hydrogen in which pulses of carbon monoxide were injected. Activation energies for the methanation reaction and hydrogen desorption from the manganate minerals were obtained and compared with those of pure nickel. Similar energy values indicate that the activity of the nodule materials for the reaction appears to be related to the amount of reducible transition metals present in the samples (ca. 11 wt.-%). Since the activity of the nodule minerals per gram is comparable to that of pure nickel, most of the transition metal ions located between manganese oxide layers appear to be exposed and available to catalyze the reaction.

  19. Titan - Discovery of carbon monoxide in its atmosphere

    NASA Technical Reports Server (NTRS)

    Lutz, B. L.; De Bergh, C.; Owen, T.

    1983-01-01

    The 3-0 rotation-vibration band of carbon monoxide was identified in the near-infrared spectrum of Titan. A preliminary mixing ratio of CO/N2 = 0.00006 was determined. This result supports the probable detection of CO by Samuelson et al and strengthens possible analogies between the atmosphere of Titan and conditions on the primitive earth. Previously announced in STAR as N83-14039

  20. Residential Carbon Monoxide Detector Failure Rates in the United States

    PubMed Central

    Arnold, Katherine J.

    2011-01-01

    There are more than 38 million residential carbon monoxide detectors installed in the United States. We tested 30 detectors in use and found that more than half failed to function properly, alarming too early or too late. Forty percent of detectors failed to alarm in hazardous concentrations, despite outward indications that they were operating as intended. Public health professionals should consider community education concerning detector use and should work with stakeholders to improve the reliability and accuracy of these devices. PMID:21852643

  1. Guideline for modeling carbon monoxide from roadway intersections

    SciTech Connect

    DiCristofaro, D.C.

    1992-11-01

    The guideline is designed to evaluate air quality impacts at one or more roadway intersections where vehicular traffic will cause or contribute to increased emissions of carbon monoxide (CO). The explicit purpose of the guideline is to provide a consistent, scientifically acceptable method for estimating the air quality impacts of vehicular traffic at intersections to determine if such impacts may exceed the National Ambient Air Quality Standards (NAAQS) for CO.

  2. CRISM Observations of Water Vapor and Carbon Monoxide

    NASA Technical Reports Server (NTRS)

    Smith, Michael D.; Wolff, Michael J.; Clancy, R. Todd

    2008-01-01

    Near-infrared spectra returned by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM, [1]) on-board the Mars Reconnaissance Orbiter (MRO) contain the clear spectral signature of several atmospheric gases including carbon dioxide (CO2), water vapor (H2O), and carbon monoxide (CO). Here we describe the seasonal and spatial mapping of water vapor and carbon dioxide for one full Martian year using CRISM spectra.

  3. COPPER RESEARCH UPDATE

    EPA Science Inventory

    This presentation provides an update and overview of new research results and remaining research needs with respect to copper corrosion control issues. The topics to be covered include: occurrence of elevated copper release in systems that meet the Action Level; impact of water c...

  4. Mobile Carbon Monoxide Monitoring System Based on Arduino-Matlab for Environmental Monitoring Application

    NASA Astrophysics Data System (ADS)

    Azieda Mohd Bakri, Nur; Junid, Syed Abdul Mutalib Al; Razak, Abdul Hadi Abdul; Idros, Mohd Faizul Md; Karimi Halim, Abdul

    2015-11-01

    Nowadays, the increasing level of carbon monoxide globally has become a serious environmental issue which has been highlighted in most of the country globally. The monitoring of carbon monoxide content is one of the approaches to identify the level of carbon monoxide pollution towards providing the solution for control the level of carbon monoxide produced. Thus, this paper proposed a mobile carbon monoxide monitoring system for measuring the carbon monoxide content based on Arduino-Matlab General User Interface (GUI). The objective of this project is to design, develop and implement the real-time mobile carbon monoxide sensor system and interfacing for measuring the level of carbon monoxide contamination in real environment. Four phases or stages of work have been carried out for the accomplishment of the project, which classified as sensor development, controlling and integrating sensor, data collection and data analysis. As a result, a complete design and developed system has been verified with the handheld industrial standard carbon monoxide sensor for calibrating the sensor sensitivity and measurement in the laboratory. Moreover, the system has been tested in real environments by measuring the level of carbon monoxide in three different lands used location; industrial area; residential area and main road (commercial area). In this real environment test, the industrial area recorded the highest reading with 71.23 ppm and 82.59 ppm for sensor 1 and sensor 2 respectively. As a conclusion, the mobile realtime carbon monoxide system based on the Arduino-Matlab is the best approach to measure the carbon monoxide concentration in different land-used since it does not require a manual data collection and reduce the complexity of the existing carbon monoxide level concentration measurement practise at the same time with a complete data analysis facilities.

  5. DO3-type cubic structure of nonstoichiometric vanadium monoxide

    NASA Astrophysics Data System (ADS)

    Davydov, D. A.; Gusev, A. I.

    2010-03-01

    An X-ray diffraction study indicates that nonstoichiometric vanadium monoxide VO y ≡ V x O z ( y = z/x) has a cubic structure of the DO3 type (space group Fm bar 3 m), where vanadium atoms are not only at the 4( a) sites of the metal fcc sublattice, but also at the tetrahedral 8( c) sites. This circumstance fundamentally distinguishes monoxide VO y from strongly nonstoichiometric MX y compounds with the B1 structure and the same space group, where atoms M and X and structural vacancies ▪ and ▭ of the metal and nonmetal sublattices, respectively, are distributed over the 4( a) and 4( b) sites. The dependence of the filling factor q of the tetrahedral interstices by vanadium atoms on the relative content y of oxygen in VO y has been obtained. It has been shown that the composition of cubic vanadium monoxide should be represented as VO y ≡ V x O z ≡ V x - 2 q V{2/q ( t)}▪1 - x + 2 q O z ▭1 - z , taking into account the structure.

  6. Carbon monoxide fractions in cigarette and hookah (hubble bubble) smoke.

    PubMed

    Sajid, K M; Akhter, M; Malik, G Q

    1993-09-01

    We studied the carbon monoxide (CO) fractions in hookah and cigarette smoke, using a carbon monoxide micro smokerlyzer (model EC50, BEDFONT, U.K.). Mean carbon monoxide fractions (% by volume) of hookah smoke, using domestic charcoal were 0.38 +/- 0.07 (large hookah; unfiltered); 1.40 +/- 0.43 (small hookah; unfiltered); 0.34 +/- 0.06 (large hookah; filtered); 1.36 +/- 0.35 (small hookah; filtered) and 0.41 +/- 0.08 (cigarette smoke). The highest fractions were obtained with small size hookah and increase in size of hookah (i.e., volume of air in water base, fire bowl volume, pipe length, etc.) reduced the CO fraction significantly (P < 0.001). The fractions of cigarette lie between large and small hookah. The fractions vary slightly with different varieties of tobacco, e.g., CO fractions with Dera wala tobacco are significantly low (P < 0.05). Use of commercial charcoal gives significant rise in CO fractions (P < 0.001). Comparison of filtered and unfiltered smoke shows no significant difference in values. We conclude that the CO hazard is as high with hookah smoking as with cigarette smoking.

  7. Molecular dynamics simulation of photodissociation of carbon monoxide from hemoglobin

    SciTech Connect

    Henry, E.R.; Levitt, M.; Eaton, W.A.

    1985-04-01

    A molecular dynamics simulation of the photodissociation of carbon monoxide from the alpha subunit of hemoglobin is described. To initiate photodissociation, trajectories of the liganded molecule were interrupted, the iron-carbon monoxide bond was broken, and the parameters of the iron-nitrogen bonds were simultaneously altered to produce a deoxyheme conformation. Heme potential functions were used that reproduce the energies and forces for the iron out-of-plane motion obtained from quantum mechanical calculations. The effect of the protein on the rate and extent of the displacement of the iron from the porphyrin plane was assessed by comparing the results with those obtained for an isolated complex of heme with imidazole and carbon monoxide. The half-time for the displacement of the iron from the porphyrin plane was found to be 50-150 fs for both the protein and the isolated complex. These results support the interpretation of optical absorption studies using 250-fs laser pulses that the iron is displaced from the porphyrin plane within 350 fs in both hemoglobin and a free heme complex in solution.

  8. Green Luminescent Copper Nanoparticles

    NASA Astrophysics Data System (ADS)

    Suresh, Y.; Annapurna, S.; Bhikshamaiah, G.; Singh, A. K.

    2016-09-01

    Copper nanoparticles are synthesized by a green chemical reduction method using Gum Kondagogu extract as stabilizer. The as-prepared powder samples are characterized by Transmission Electron Microscopy (TEM), Small Angle X-Ray Scattering (SAXS), UV-Visible Spectroscopy, X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) techniques. The as-prepared copper nanoparticles are found to be FCC crystalline and nearly monodispersed with particles size 19 nm. Photoluminescence (PL) measurement showed strong green visible emission and PL intensity was found enhanced with the presence of natural extract on copper nanoparticle surface. The increase in the PL intensity was mainly due to copper nanoparticles. Photoluminescence spectra of copper nanoparticles show an emission peak at 430 nm when illuminated at 325 nm.

  9. Bioaccessibility and Solubility of Copper in Copper-Treated Lumber

    EPA Science Inventory

    Micronized copper (MC)-treated lumber is a recent replacement for Chromated Copper Arsenate (CCA) and Ammonium Copper (AC)-treated lumbers; though little is known about the potential risk of copper (Cu) exposure from incidental ingestion of MC-treated wood. The bioaccessibility o...

  10. Bioaccessibility and Solubility of Copper in Copper-Treated Lumber

    EPA Science Inventory

    Micronized copper (MC)-treated lumber is a recent replacement for Chromated Copper Arsenate (CCA) and Ammonium Copper (AC)-treated lumbers; though little is known about the potential risk of copper (Cu) exposure from incidental ingestion of MC-treated wood. The bioaccessibility o...

  11. Killing of bacteria by copper surfaces involves dissolved copper.

    PubMed

    Molteni, Cristina; Abicht, Helge K; Solioz, Marc

    2010-06-01

    Bacteria are rapidly killed on copper surfaces. However, the mechanism of this process remains unclear. Using Enterococcus hirae, the effect of inactivation of copper homeostatic genes and of medium compositions on survival and copper dissolution was tested. The results support a role for dissolved copper ions in killing.

  12. The Effect of Copper Addition on the Activity and Stability of Iron-Based CO₂ Hydrogenation Catalysts.

    PubMed

    Bradley, Matthew J; Ananth, Ramagopal; Willauer, Heather D; Baldwin, Jeffrey W; Hardy, Dennis R; Williams, Frederick W

    2017-09-20

    Iron-based CO₂ catalysts have shown promise as a viable route to the production of olefins from CO₂ and H₂ gas. However, these catalysts can suffer from low conversion and high methane selectivity, as well as being particularly vulnerable to water produced during the reaction. In an effort to improve both the activity and durability of iron-based catalysts on an alumina support, copper (10-30%) has been added to the catalyst matrix. In this paper, the effects of copper addition on the catalyst activity and morphology are examined. The addition of 10% copper significantly increases the CO₂ conversion, and decreases methane and carbon monoxide selectivity, without significantly altering the crystallinity and structure of the catalyst itself. The FeCu/K catalysts form an inverse spinel crystal phase that is independent of copper content and a metallic phase that increases in abundance with copper loading (>10% Cu). At higher loadings, copper separates from the iron oxide phase and produces metallic copper as shown by SEM-EDS. An addition of copper appears to increase the rate of the Fischer-Tropsch reaction step, as shown by modeling of the chemical kinetics and the inter- and intra-particle transport of mass and energy.

  13. Embedding of copper sulfate and copper oxide on multipurpose paper

    NASA Astrophysics Data System (ADS)

    Almanza, D. L. V.; de Luna, J. L. A.; Herrera, M. U.

    2017-05-01

    Copper sulfate salts were embedded on multipurpose paper using simple soaking technique while copper oxide particles were embedded using in-situ technique. In simple soaking technique, the papers were simply soaked in copper sulfate solution in order for the copper salts to be incorporated in the paper. In the in-situ technique, the copper sulfate-embedded papers were soaked in sodium hydroxide solution for reactions to occur that will lead to the formation of copper oxide. Copper sulfate-embedded papers have blue green color while copper oxide-embedded papers have brown color. The copper sulfate-embedded paper shows excellent antimicrobial property against Staphylococcus aureus. Meanwhile, the copper oxide-embedded paper shows small zone of inhibition against Escherichia coli and Staphylococcus aureus.

  14. Central Diabetes Insipidus and Hyperglycemic Hyperosmolar State Following Accidental Carbon Monoxide Poisoning.

    PubMed

    Ul Abideen, Zain; Mahmud, Syed Nayer; Rasheed, Amna; Farooq Qasim, Yusaf; Ali, Furqan

    2017-06-03

    Carbon monoxide poisoning is common and carries significant morbidity and mortality. The nervous system, particularly the brain, is frequently affected by it, owing to its high metabolic activity and oxygen requirements. Carbon monoxide damages the nervous system by both hypoxic and inflammatory mechanisms. Central diabetes insipidus is an extremely rare complication of carbon monoxide poisoning. Herein, we report the case of a young lady, who developed this complication and severe hypernatremia after accidental carbon monoxide poisoning. She also developed a hyperglycemic hyperosmolar state during the treatment for hypernatremia. To the best of our knowledge, both these entities have not been reported together in association with carbon monoxide poisoning. The purpose of this article is to emphasize the anticipation and early recognition of central diabetes insipidus in carbon monoxide poisoning. This can prevent severe hypernatremia and complications associated with its presence and treatment.

  15. Gas geyser--a cause of fatal domestic carbon monoxide poisoning.

    PubMed

    Mohankumar, T S; Kanchan, Tanuj; Pinakini, K S; Menezes, Ritesh G; Singh, Manisha; Sirohi, Parmendra; Anwar, Naureen

    2012-11-01

    Carbon monoxide is responsible for a large number of accidental domestic poisoning and deaths throughout the world. Domestic carbon monoxide poisoning is rarely reported in India and remains an under recognized problem. The diagnosis of carbon monoxide poisoning is usually based on autopsy findings, circumstantial evidence and estimation of carboxy-haemoglobin in blood. We report a case of fatal accidental carbon monoxide poisoning in a bathroom where an LPG gas water heater was installed recently. Cherry pink discolouration of the body and organs on autopsy suggested carbon monoxide poisoning. Laboratory analysis of blood by UV visible spectrophotometry revealed presence of dangerous levels of carboxy-haemoglobin. Effective preventive measures can help in bringing down the mortality and morbidity associated with carbon monoxide poisoning.

  16. Experimental evaluation of the ignition process of carbon monoxide and oxygen in a rocket engine

    NASA Technical Reports Server (NTRS)

    Linne, Diane L.

    1996-01-01

    Carbon monoxide and oxygen ignition boundaries were determined in a spark torch igniter as a function of propellant inlet temperatures. The oxygen temperature was varied from ambient to -258 F, and the carbon monoxide temperature was varied from ambient to -241 F. With the oxygen and carbon monoxide at -253 F and -219 F, respectively, they successfully ignited between mixture ratios of 2.42 and 3.10. Analysis of the results indicated that the lower ignition boundary was more sensitive to oxygen temperature than to carbon monoxide temperature. Another series of tests was performed in a small simulated rocket engine with oxygen at -197 F and carbon monoxide at -193 F. An oxygen/hydrogen flame was used to initiate combustion of the oxygen and carbon monoxide. Tests performed at the optimum operating mixture ratio of 0.55 obtained steady-state combustion in every test.

  17. Fabricating Copper Nanotubes by Electrodeposition

    NASA Technical Reports Server (NTRS)

    Yang, E. H.; Ramsey, Christopher; Bae, Youngsam; Choi, Daniel

    2009-01-01

    Copper tubes having diameters between about 100 and about 200 nm have been fabricated by electrodeposition of copper into the pores of alumina nanopore membranes. Copper nanotubes are under consideration as alternatives to copper nanorods and nanowires for applications involving thermal and/or electrical contacts, wherein the greater specific areas of nanotubes could afford lower effective thermal and/or electrical resistivities. Heretofore, copper nanorods and nanowires have been fabricated by a combination of electrodeposition and a conventional expensive lithographic process. The present electrodeposition-based process for fabricating copper nanotubes costs less and enables production of copper nanotubes at greater rate.

  18. Structures of late transition metal monoxides from Jahn-Teller instabilities in the rock salt lattice.

    PubMed

    Derzsi, Mariana; Piekarz, Przemysław; Grochala, Wojciech

    2014-07-11

    Most late transition metal (LTM) monoxides crystallize in other than a rock salt structure, which is so common in the earlier transition metal monoxides. Here we present theoretical evidence based on density functional theory that an electron-phonon coupling involving a single soft mode in the cubic cell is responsible for the onset of the experimentally observed structures of the late transition metal monoxides.

  19. Cardiovascular effects of chronic carbon monoxide and high-altitude exposure

    SciTech Connect

    McGrath, J.J. )

    1989-07-01

    At higher altitudes, ambient carbon monoxide levels are increasing with the number of residents and tourists and their use of motor vehicles and heating devices (such as fireplaces, furnaces, and stoves). Although chronic exposure to carbon monoxide or high altitude causes pronounced cardiovascular changes in humans as well as in animals, there is little information on the effects elicited by these stressors combined. Data from acute studies and theoretical considerations suggest that carbon monoxide inhaled at altitude may be more detrimental than carbon monoxide inhaled at sea level. It is not known, however, if the cardiovascular system adapts or deteriorates with continuous, concurrent exposure to carbon monoxide and high altitude. Male laboratory rats were exposed for six weeks in steel barometric chambers to altitudes ranging from 3,300 ft (ambient) to 18,000 ft and to concentrations ranging from 0 to 500 parts per million (ppm)2. Carbon monoxide had no effect on body weight at any altitude. There was a tendency for hematocrit to increase even at the lowest concentration of carbon monoxide (9 ppm), but the increase did not become significant until 100 ppm. At 10,000 ft, there was a tendency for total heart weight to increase in rats inhaling 100 ppm carbon monoxide. Although its effects on the heart at altitude are complex, carbon monoxide, in concentrations of 500 ppm or less, had little effect on the right ventricle; it did not exacerbate any effects due to altitude. There was a tendency for the left ventricle weight to increase with exposure to 35 ppm carbon monoxide at altitude, but the increase was not significant until 100 ppm carbon monoxide. Heart rate, blood pressure, cardiac output, and peripheral resistance were unaffected by exposure to 35 ppm carbon monoxide or 10,000-ft altitude singly or in combination.

  20. TES/Aura L2 Carbon Monoxide (CO) Lite Nadir V6 (TL2COLN)

    Atmospheric Science Data Center

    2017-07-20

    TES/Aura L2 Carbon Monoxide (CO) Lite Nadir (TL2COLN) News:  TES News ... Level:  L2 Instrument:  TES/Aura L2 Carbon Monoxide Spatial Coverage:  5.3 km nadir ... OPeNDAP Access:  OPeNDAP Parameters:  Carbon Monoxide Order Data:  Earthdata Search:   Order Data ...

  1. COPPER CABLE RECYCLING TECHNOLOGY

    SciTech Connect

    Chelsea Hubbard

    2001-05-01

    The United States Department of Energy (DOE) continually seeks safer and more cost-effective technologies for use in deactivation and decommissioning (D&D) of nuclear facilities. The Deactivation and Decommissioning Focus Area (DDFA) of the DOE's Office of Science and Technology (OST) sponsors large-scale demonstration and deployment projects (LSDDPs). At these LSDDPs, developers and vendors of improved or innovative technologies showcase products that are potentially beneficial to the DOE's projects and to others in the D&D community. Benefits sought include decreased health and safety risks to personnel and the environment, increased productivity, and decreased costs of operation. The Idaho National Engineering and Environmental Laboratory (INEEL) generated a list of statements defining specific needs and problems where improved technology could be incorporated into ongoing D&D tasks. One such need is to reduce the volume of waste copper wire and cable generated by D&D. Deactivation and decommissioning activities of nuclear facilities generates hundreds of tons of contaminated copper cable, which are sent to radioactive waste disposal sites. The Copper Cable Recycling Technology separates the clean copper from contaminated insulation and dust materials in these cables. The recovered copper can then be reclaimed and, more importantly, landfill disposal volumes can be reduced. The existing baseline technology for disposing radioactively contaminated cables is to package the cables in wooden storage boxes and dispose of the cables in radioactive waste disposal sites. The Copper Cable Recycling Technology is applicable to facility decommissioning projects at many Department of Energy (DOE) nuclear facilities and commercial nuclear power plants undergoing decommissioning activities. The INEEL Copper Cable Recycling Technology Demonstration investigated the effectiveness and efficiency to recycle 13.5 tons of copper cable. To determine the effectiveness of separating

  2. [Copper and the human body].

    PubMed

    Krízek, M; Senft, V; Motán, J

    1997-11-19

    Copper is one of the essential trace elements. It is part of a number of enzymes. Deficiency of the element is manifested by impaired haematopoesis, bone metabolism, disorders of the digestive, cardiovascular and nervous system. Deficiency occurs in particular in patients suffering from malnutrition, malabsorption, great copper losses during administration of penicillamine. Sporadically copper intoxications are described (suicidal intentions or accidental ingestion of beverages with a high copper content). Acute exposure to copper containing dust is manifested by metal fume fever. Copper salts can produce local inflammations. Wilson's disease is associated with inborn impaired copper metabolism. In dialyzed patients possible contaminations of the dialyzate with copper must be foreseen as well as the possible release of copper from some dialyzation membranes. With the increasing amount of copper in the environment it is essential to monitor the contamination of the environment.

  3. Carbon monoxide poisoning - Immediate diagnosis and treatment are crucial to avoid complications.

    SciTech Connect

    Rosenthal, L.D.

    2006-03-15

    Carbon monoxide is an odorless, colorless, tasteless gas produced by the incomplete combustion of carbon-containing fuels (oil, kerosene, coal, wood) or the inadequate ventilation of natural gas. When carbon monoxide is introduced into the bloodstream, it binds to hemoglobin, reducing the number of binding sites available for oxygen. Carbon monoxide also changes the structure of the hemoglobin molecule, which makes it even more difficult for oxygen that has attached to be released into tissues. The resulting tissue ischemia can lead to organ failure, permanent changes in cognition, or death. Carbon monoxide poisoning is the leading cause of death by poisoning in industrialized countries.

  4. Abnormal fingernail beds following carbon monoxide poisoning: a case report and review of the literature

    PubMed Central

    2014-01-01

    Introduction Carbon monoxide poisoning is a very common cause of death in accidental, suicidal, or homicidal cases throughout the world. Fingernail bed manifestation is reported in survivors of carbon monoxide poisoning. Case presentation A 40-year-old Caucasian woman was exposed to carbon monoxide when she was sleeping alone in her one-bedroom apartment; fortunately, the beeps from her First Alert combination smoke and carbon monoxide detector woke her and she was saved from any extensive health issues. The most indicative symptoms experienced were a severe headache, blurred vision, agitation, and confusion. Following contact with the Emergency Responses Services, she was promptly transferred to the hospital via ambulance and was treated with high-flow oxygen on the way. She was discharged from the emergency department on the same day, but carbon monoxide exposure had already had adverse effects on her fingernail beds. The fingernail tips were altered and appeared as if a bite had been taken out of their distal borders. The changes in the tips of her fingernails were significant, but they completely disappeared eight weeks later without any additional treatment. Conclusions Worldwide, carbon monoxide poisoning is a potentially lethal condition that is preventable with educational programs and installation of carbon monoxide detectors in the home setting. Exposure to carbon monoxide frequently goes unrecognized until it is too late and causes silent death. To the best of the authors’ knowledge, this is the first report in the literature of fingernail bed manifestations in a survivor of carbon monoxide poisoning. PMID:25073414

  5. Ambient carbon monoxide and the risk of hospitalization due to chronic obstructive pulmonary disease.

    PubMed

    Tian, Linwei; Ho, Kin-fai; Wang, Tong; Qiu, Hong; Pun, Vivian C; Chan, Chi Sing; Louie, Peter K K; Yu, Ignatius T S

    2014-12-15

    Data from recent experimental and clinical studies have indicated that lower concentrations of inhaled carbon monoxide might have beneficial antiinflammatory effects. Inhaled carbon monoxide has the potential to be a therapeutic agent for chronic obstructive pulmonary diseases (COPD). However, population-based epidemiologic studies of environmentally relevant carbon monoxide exposure have generated mixed findings. We conducted a time-series study in Hong Kong to estimate the association of short-term exposure to ambient carbon monoxide with emergency hospitalizations for COPD. We collected daily emergency hospital admission data and air pollution data from January 2001 to December 2007. We used log-linear Poisson models to estimate the associations between daily hospital admissions for COPD and the average daily concentrations of carbon monoxide while controlling for the traffic-related co-pollutants nitrogen dioxide and particulate matter with an aerodynamic diameter less than 2.5 μm. Results showed that ambient carbon monoxide was negatively associated with the risk of hospitalizations for COPD. After adjustment for levels nitrogen dioxide or particulate matter with an aerodynamic diameter less than 2.5 μm, the negative associations of carbon monoxide with COPD hospitalizations became stronger. The risk estimates were similar for female and male subjects. In conclusion, short-term exposure to ambient carbon monoxide was associated with a decreased risk of hospitalization for COPD, which suggests that carbon monoxide exposure provides some acute protection of against exacerbation of COPD.

  6. Targeting copper in cancer therapy: 'Copper That Cancer'.

    PubMed

    Denoyer, Delphine; Masaldan, Shashank; La Fontaine, Sharon; Cater, Michael A

    2015-11-01

    Copper is an essential micronutrient involved in fundamental life processes that are conserved throughout all forms of life. The ability of copper to catalyze oxidation-reduction (redox) reactions, which can inadvertently lead to the production of reactive oxygen species (ROS), necessitates the tight homeostatic regulation of copper within the body. Many cancer types exhibit increased intratumoral copper and/or altered systemic copper distribution. The realization that copper serves as a limiting factor for multiple aspects of tumor progression, including growth, angiogenesis and metastasis, has prompted the development of copper-specific chelators as therapies to inhibit these processes. Another therapeutic approach utilizes specific ionophores that deliver copper to cells to increase intracellular copper levels. The therapeutic window between normal and cancerous cells when intracellular copper is forcibly increased, is the premise for the development of copper-ionophores endowed with anticancer properties. Also under investigation is the use of copper to replace platinum in coordination complexes currently used as mainstream chemotherapies. In comparison to platinum-based drugs, these promising copper coordination complexes may be more potent anticancer agents, with reduced toxicity toward normal cells and they may potentially circumvent the chemoresistance associated with recurrent platinum treatment. In addition, cancerous cells can adapt their copper homeostatic mechanisms to acquire resistance to conventional platinum-based drugs and certain copper coordination complexes can re-sensitize cancer cells to these drugs. This review will outline the biological importance of copper and copper homeostasis in mammalian cells, followed by a discussion of our current understanding of copper dysregulation in cancer, and the recent therapeutic advances using copper coordination complexes as anticancer agents.

  7. Micromachining with copper lasers

    NASA Astrophysics Data System (ADS)

    Knowles, Martyn R. H.; Bell, Andy; Foster-Turner, Gideon; Rutterford, Graham; Chudzicki, J.; Kearsley, Andrew J.

    1997-04-01

    In recent years the copper laser has undergone extensive development and has emerged as a leading and unique laser for micromachining. The copper laser is a high average power (10 - 250 W), high pulse repetition rate (2 - 32 kHz), visible laser (511 nm and 578 nm) that produces high peak power (typically 200 kW), short pulses (30 ns) and very good beam quality (diffraction limited). This unique set of laser parameters results in exceptional micro-machining in a wide variety of materials. Typical examples of the capabilities of the copper laser include the drilling of small holes (10 - 200 micrometer diameter) in materials as diverse as steel, ceramic, diamond and polyimide with micron precision and low taper (less than 1 degree) cutting and profiling of diamond. Application of the copper laser covers the electronic, aerospace, automotive, nuclear, medical and precision engineering industries.

  8. Volatility of copper

    SciTech Connect

    Palmer, D.A.; Simonson, J.M.; Joyce, D.B.

    1996-08-01

    The relevant aqueous thermodynamics of copper and its oxides are evaluated and summarized with emphasis on solubility, hydrolysis, and complexation. The solubilities of metallic copper, solid cuprous and cupric oxides in steam measured by Pocock and Stewart in 1963 are discussed and the latter data are fitted in the form of established empirical equations and compared to other existing results. No other sources of data were found for the solubility of copper and cupric oxide in steam and even these data are very limited. Discussion of corresponding available solubility data on both oxide phases in liquid water is given. The possible effects of complexing agents are considered. A brief discussion is provided of the role of surface adsorption in determining the fate of dissolved copper in the boiler. 37 refs., 5 figs., 3 tabs.

  9. Mixing ratios of carbon monoxide in the troposphere

    SciTech Connect

    Novelli, P.C.; Steele, L.P. ); Tans, P.P. )

    1992-12-20

    Carbon monoxide (CO) mixing ratios were measured in air samples collected weekly at eight locations. The air was collected as part of the CMDL/NOAA cooperative flask sampling program (Climate Monitoring and Diagnostics Laboratory, formerly Geophysical Monitoring for Climatic Change, Air Resources Laboratory/National Oceanic and Atmospheric Administration) at Point Barrow, Alaska, Niwot Ridge, Colorado, Mauna Loa and Cape Kumakahi, Hawaii, Guam, Marianas Islands, Christmas Island, Ascension Island and American Samoa. Half-liter or 3-L glass flasks fitted with glass piston stopcocks holding teflon O rings were used for sample collection. CO levels were determined within several weeks of collection using gas chromatography followed by mercuric oxide reduction detection, and mixing ratios were referenced against the CMDL/NOAA carbon monoxide standard scale. During the period of study (mid-1988 through December 1990) CO levels were greatest in the high latitudes of the northern hemisphere (mean mixing ratio from January 1989 to December 1990 at Point Barrow was approximately 154 ppb) and decreased towards the south (mean mixing ratio at Samoa over a similar period was 65 ppb). Mixing ratios varied seasonally, the amplitude of the seasonal cycle was greatest in the north and decreased to the south. Carbon monoxide levels were affected by both local and regional scale processes. The difference in CO levels between northern and southern latitudes also varied seasonally. The greatest difference in CO mixing ratios between Barrow and Samoa was observed during the northern winter (about 150 ppb). The smallest difference, 40 ppb, occurred during the austral winter. The annually averaged CO difference between 71[degrees]N and 14[degrees]S was approximately 90 ppb in both 1989 and 1990; the annually averaged interhemispheric gradient from 71[degrees]N to 41[degrees]S is estimated as approximately 95 ppb. 66 refs., 5 figs., 5 tabs.

  10. Pathways and Bioenergetics of Anaerobic Carbon Monoxide Fermentation

    PubMed Central

    Diender, Martijn; Stams, Alfons J. M.; Sousa, Diana Z.

    2015-01-01

    Carbon monoxide can act as a substrate for different modes of fermentative anaerobic metabolism. The trait of utilizing CO is spread among a diverse group of microorganisms, including members of bacteria as well as archaea. Over the last decade this metabolism has gained interest due to the potential of converting CO-rich gas, such as synthesis gas, into bio-based products. Three main types of fermentative CO metabolism can be distinguished: hydrogenogenesis, methanogenesis, and acetogenesis, generating hydrogen, methane and acetate, respectively. Here, we review the current knowledge on these three variants of microbial CO metabolism with an emphasis on the potential enzymatic routes and bio-energetics involved. PMID:26635746

  11. Comparison between carbon monoxide measurements from spaceborne and airborne platforms

    NASA Technical Reports Server (NTRS)

    Connors, V. S.; Cahoon, D. R.; Reichle, H. G., Jr.; Scheel, H. E.

    1991-01-01

    The measurements of air pollution from satellites (MAPS) experiment measured the distribution of middle tropospheric carbon monoxide (CO) from the Space Shuttle during October 1984. A critical area of the experiment is the assessment of experimental error of the MAPS data. This error is determined by the comparison between the space-based CO data and concurrent, direct CO measurements taken aboard aircraft. Because of the variability in the CO measurements near land sources, a strategy for comparing the tropospheric CO measurements over the remote oceans is presented.

  12. Thermal Degradation of Lead Monoxide Filled Polymer Composite Radiation Shields

    SciTech Connect

    Harish, V.; Nagaiah, N.

    2011-07-15

    Lead monoxide filled Isophthalate resin particulate polymer composites were prepared with different filler concentrations and investigated for physical, thermal, mechanical and gamma radiation shielding characteristics. This paper discusses about the thermo gravimetric analysis of the composites done to understand their thermal properties especially the effect of filler concentration on the thermal stability and degradation rate of composites. Pristine polymer exhibits single stage degradation whereas filled composites exhibit two stage degradation processes. Further, the IDT values as well as degradation rates decrease with the increased filler content in the composite.

  13. Compact carbon monoxide sensor utilizing a confocal optical cavity.

    NASA Technical Reports Server (NTRS)

    Scott, B.; Magyar, J.; Weyant, R.; Hall, J.

    1973-01-01

    The carbon monoxide sensor discussed in this paper utilizes a unique confocal cavity which allows the complete system to be packaged in a small volume suitable for hand-held use. The optical system is the heart of the instrument with equal emphasis placed on the electronics support circuitry, consisting essentially of a thermal infrared pyroelectric detector and lock-in amplifier. The pyroelectric detector offers a major advantage over other thermal detectors, providing a signal-to-noise ratio and detectivity that remain nearly constant over the frequency range from dc to 2000 Hz. Since bias voltage is not required, low frequency noise is not generated in the detector.

  14. Comparison between carbon monoxide measurements from spaceborne and airborne platforms

    NASA Technical Reports Server (NTRS)

    Connors, V. S.; Cahoon, D. R.; Reichle, H. G., Jr.; Scheel, H. E.

    1991-01-01

    The measurements of air pollution from satellites (MAPS) experiment measured the distribution of middle tropospheric carbon monoxide (CO) from the Space Shuttle during October 1984. A critical area of the experiment is the assessment of experimental error of the MAPS data. This error is determined by the comparison between the space-based CO data and concurrent, direct CO measurements taken aboard aircraft. Because of the variability in the CO measurements near land sources, a strategy for comparing the tropospheric CO measurements over the remote oceans is presented.

  15. Transient PrOx carbon monoxide measurement, control, and optimization

    SciTech Connect

    Inbody, M. A.; Borup, R. L.; Tafoya, J.

    2002-01-01

    Fuel processing systems for low temperature polymer electrolyte membrane (PEM) fuel cell systems require control of the carbon monoxide concentration to less than 100 ppm to 10 ppm in the anode feed. Conventional hydrocarbon fuel processors use a water-gas shift (WGS) reactor to react CO with water to form H2 and reduce the CO concentration. The CO conversion is limited by equilibrium at the outlet temperature of the WGS reactor. The WGS outlet CO concentration can range from over 1% to 2000 ppm depending on the system and its operating parameters. At these concentrations, CO poisons low temperature PEM fuel cells and the concentrations needs to be reduced further.

  16. Relativistic spinless rotation-vibrational energies of carbon monoxide

    NASA Astrophysics Data System (ADS)

    Tang, Bin; Jia, Chun-Sheng

    2017-09-01

    We solve the Klein-Gordon equation with the simplified Pöschl-Teller potential model by employing the shape invariance technique, and present the relativistic spinless rotation-vibrational energy equation for diatomic molecules with nuclear spin of zero. It is found that the relativistic effects subject to the relative motion of the ions increase slightly the spinless vibrational energies of the ground electronic state of the carbon monoxide molecule in comparison to the nonrelativistic results. We observe that the variation of the relativistic spinless rotation-vibrational energies with respect to the vibrational quantum number in larger rotational quantum numbers holds similar to that with rotational quantum number of zero.

  17. Detecting the dipole moment of a single carbon monoxide molecule

    SciTech Connect

    Schwarz, A. Köhler, A.; Grenz, J.; Wiesendanger, R.

    2014-07-07

    Using non-contact atomic force microscopy with metallic tips enabled us to detect the electrostatic dipole moment of single carbon monoxide (CO) molecules adsorbed on three very different substrates. The observed distance dependent contrast can be explained by an interplay between the attractive van der Waals interaction and the repulsive electrostatic interaction, respectively, with the latter stemming from antiparallel aligned dipoles in tip and molecule. Our results suggest that metallic as well as CO-functionalized tips are able to probe electrostatic properties of polar molecules and that repulsive dipole-dipole interactions have to be considered when interpreting complex contrast patterns.

  18. OMI Observations of Bromine Monoxide Emissions from Volcanoes

    NASA Astrophysics Data System (ADS)

    Suleiman, R. M.; Chance, K.; Liu, X.; Gonzalez Abad, G.; Kurosu, T. P.

    2016-12-01

    We analyze bromine monoxide (BrO) data from the Ozone Monitoring Instrument (OMI) for emissions from various volcanoes. We use OMI data from 2005 to 2014 to investigate BrO signatures from Galapagos, Kasatochi and Eyjafjallajökull volcanoes. Elevated signatures of BrO daily averages were found over Eyjafjallajökull. SO2 cross sections are updated in the operational BrO algorithm and their effect on the volcanic BrO signature is studied. Comparison between two different sets of SO2 cross sections is made and results still show BrO enhancement over the Eyjafjallajökull region.

  19. Compact carbon monoxide sensor utilizing a confocal optical cavity.

    NASA Technical Reports Server (NTRS)

    Scott, B.; Magyar, J.; Weyant, R.; Hall, J.

    1973-01-01

    The carbon monoxide sensor discussed in this paper utilizes a unique confocal cavity which allows the complete system to be packaged in a small volume suitable for hand-held use. The optical system is the heart of the instrument with equal emphasis placed on the electronics support circuitry, consisting essentially of a thermal infrared pyroelectric detector and lock-in amplifier. The pyroelectric detector offers a major advantage over other thermal detectors, providing a signal-to-noise ratio and detectivity that remain nearly constant over the frequency range from dc to 2000 Hz. Since bias voltage is not required, low frequency noise is not generated in the detector.

  20. THE EQUILIBRIUM BETWEEN CYTOCHROME OXIDASE AND CARBON MONOXIDE

    PubMed Central

    Wald, George; Allen, David W.

    1957-01-01

    An evolution argument which attempted to trace the development of hemoglobins from such respiratory pigments as cytochrome oxidase presupposed that the latter possesses, in addition to its high affinity for oxygen, an approximately hyperbolic equilibrium function, and little if any Bohr effect (decline in affinity for oxygen with rise in acidity). Since cytochrome oxidase, unlike hemoglobin, is irreversibly oxidized by oxygen, the present experiments examine its combination with carbon monoxide, with which, like hemoglobin, it yields a true equilibrium. In all known hemoglobins the form of the equilibrium function and the vigor of the Bohr effect are similar with carbon monoxide and with oxygen, so that observations involving the former gas are relevant to the relations of the latter. The equilibrium function of cytochrome oxidase with carbon monoxide—percentage saturation vs. partial pressure of CO—is slightly inflected (in the Hill equation n = 1.26; for a hyperbola, n = 1). No Bohr effect is present in the range of pH 7–8. The pressure of carbon monoxide at which half-saturation occurs (p50) is about 0.17 mm. at 10–13°C. The affinity for carbon monoxide is therefore higher than commonly supposed. These properties are consistent with the evolution argument. They are important also for the physiological functioning of cytochrome oxidase, the nearly hyperbolic equilibrium function facilitating a high degree of saturation, and the lack of Bohr effect making this enzyme impervious to hyperacidity. The slight inflection of the equilibrium function shows that the Fe-porphyrin units of cytochrome oxidase interact to a degree, hence that the enzyme must contain more than one such unit per molecule. It is suggested that in cytochrome oxidase two Fe-porphyrin groups may unite with one oxygen in the manner Fe++-O2-Fe++; and that the evolution of hemoglobins proceeded over a first stage in which the hemes were separated so that each combines with only one molecule