Sökning: "hydrogen exchange"

Visar resultat 1 - 5 av 105 avhandlingar innehållade orden hydrogen exchange.

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

    Författare :Pia Lindberg; Peter Lindblad; Kornél Kovács; Uppsala universitet; []
    Nyckelord :MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; 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

  2. 2. Modelling of a proton exchange membrane fuel cell system for automotive applications

    Författare :Kristina Johansson; KTH; []
    Nyckelord :Proton exchange membrane PEM; Fuel cell vehicle; Hydrogen; Hydrogen storage; Fuel consumption; Electric vehicles; Drive;

    Sammanfattning : .... LÄS MER

  3. 3. On direct hydrogen fuel cell vehicles : modelling and demonstration

    Författare :Kristina Haraldsson; Per Alvfors; Dougal J. Nelson; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Chemical engineering; direct hydrogen; Proton Exchange Membrane; PEM; fuel cell; fuel cell vehicle; fuel cell hybrid vehicles; on-board hydrogen storage; Kemiteknik; Chemical engineering; Kemiteknik;

    Sammanfattning : In this thesis, direct hydrogen Proton Exchange Membrane (PEM) fuel cell systems in vehicles are investigated through modelling, field tests and public acceptance surveys. A computer model of a 50 kW PEM fuel cell system was developed. The fuel cell system efficiency is approximately 50% between 10 and 45% of the rated power. LÄS MER

  4. 4. Small-Scale Production of Fuel-Cell Hydrogen

    Författare :Christian Hulteberg; Institutionen för kemiteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hydrogen; Chemical Engineering; Catalysis; Small-Scale;

    Sammanfattning : The work presented here aims at producing hydrogen for proton-exchange fuel-cell applications from hydrocarbons. This thesis describes an integrated catalytic converter comprising a steam-reforming reactor (heat of reaction supplied by catalytic combustion), a water-gas shift reactor and a preferential oxidation of carbon monoxide reactor, and the work performed on the fuel processing catalysts therein. LÄS MER

  5. 5. Ruthenium-Catalyzed Hydrogen Transfer Reactions : Mechanistic Studies and Chemoenzymatic Dynamic Kinetic Resolutions

    Författare :Madeleine Warner; Jan-Erling Bäckvall; Andreas Pfaltz; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Hydrogen transfer; ruthenium catalysis; kinetic resolution; dynamic kinetic resolution; racemization; asymmetric synthesis; Organic Chemistry; organisk kemi;

    Sammanfattning : The main focus of this thesis lies on transition metal-catalyzed hydrogen transfer reactions. In the first part of the thesis, the mechanism for racemization of sec-alcohols with a ruthenium complex, Ru(CO)2Cl(η5-C5Ph5) was studied. LÄS MER