Sökning: "MOLECULAR-HYDROGEN"

Visar resultat 1 - 5 av 22 avhandlingar innehållade ordet MOLECULAR-HYDROGEN.

  1. 1. Adsorption of Molecular Hydrogen on Cu, Pd and Ni Surfaces

    Författare :Krister Svensson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; electron energy loss spectroscopy; nickel; molecular chemisorption; hydrogen; palladium; physisorption; photodesorption; copper;

    Sammanfattning : This thesis is devoted to spectroscopic studies of molecular hydrogen adsorbed on metal surfaces. Hydrogen is the simplest molecule available and is a very valuable model adsorbate. From a spectroscopic point of view there are also three easily accessible molecular isotopes, H2, HD and D2, with widely different masses. LÄS MER

  3. 2. Cyanobacterial Hydrogen Metabolism - Uptake Hydrogenase and Hydrogen Production by Nitrogenase in Filamentous Cyanobacteria

    Författare :Pia Lindberg; Peter Lindblad; Kornél Kovács; Uppsala universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Microbiology; cyanobacteria; biohydrogen; Nostoc; hydrogen production; hydrogen evolution; hydrogen metabolism; nitrogenase; hydrogenase; hydrogen; uptake hydrogenase; hupSL; hydrogen uptake mutant; uptake hydrogenase mutant; photobioreactor; hydrogenase accessory genes; hyp; transcription; RT-PCR; NtcA; mass spectrometry; heterocyst; Mikrobiologi; Microbiology; immunology; infectious diseases; Mikrobiologi; immunologi; infektionssjukdomar;

    Sammanfattning : Molecular hydrogen is a potential energy carrier for the future. Nitrogen-fixing cyanobacteria are a group of photosynthetic microorganisms with the inherent ability to produce molecular hydrogen via the enzyme complex nitrogenase. This hydrogen is not released, however, but is recaptured by the bacteria using an uptake hydrogenase. LÄS MER

  4. 3. Mechanistic Approach to Corrosion of Zirconium by Water - A First Principle Study

    Författare :Mikaela Lindgren; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; zirconium; hydrogen pick-up; corrosion; oxygen vacancy; DFT;

    Sammanfattning : Zirconium and zirconium oxides are of major technological importance. There are broad applications for these materials, from fuel cell electrolyte to semiconductors and in hip-implants. In nuclear power plants, zirconium alloys are widely used as cladding material to contain the fission fuel in the reactor cores. LÄS MER

  5. 4. Cyanobacterial Hydrogen Metabolism : Transcriptional Regulation of the Hydrogenases in Filamentous Strains

    Författare :Rikard Axelsson; Peter Lindblad; Tomás Ruiz-Argüeso; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Molecular biology; Molekylärbiologi; Molecular biology; Molekylärbiologi;

    Sammanfattning : Cyanobacteria are a heterogeneous group of phototrophic microorganisms. Many cyanobacteria have the capacity to fix atmospheric nitrogen. During the process of nitrogen fixation, molecular hydrogen is produced. Three enzymes are directly involved in hydrogen metabolism in cyanobacteria. LÄS MER

  7. 5. Low temperature olivine alteration ; an experimental approach

    Författare :Anna Neubeck; Nils Holm; Gretchen Früh-Green; Stockholms universitet; []
    Nyckelord :Olivine alteration; hydrogen; methane; serpentinization; geokemi; Geochemistry;

    Sammanfattning : Water reacting with minerals to alter or dissolve them is a common phenomenon on Earth, leading to a unique chemical composition of the oceans and continents. The continuous circulation of elements and the chemical reactions between them creates the extraordinary environment prevailing on our Earth today and was probably an important requirement for the onset of life on our planet. LÄS MER