Sökning: "Hydrogen effect"

Visar resultat 16 - 20 av 439 avhandlingar innehållade orden Hydrogen effect.

  1. 16. Some aspects of hydrogen reduction of iron ore

    Författare :Oscar Hessling; Pär Jönsson; Du Sichen; Niklas Kojola; Henrik Saxén; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; hydrogen; reduction; iron ore; mechanisms; microstructure; Materials Science and Engineering; Teknisk materialvetenskap;

    Sammanfattning : Fines of hematite and magnetite were studied in the fluidized bed using a pure hydrogen atmosphere in the temperature range of 768 to 888 K. Hematite pellets were studied based on Thermogravimetric Analysis (TGA) experiments using hydrogen atmospheres containing 0–15 % pH2O, in the temperature range of 873 to 1173 K. LÄS MER

  3. 17. Point defects and ion conduction in solid oxides: a first-principles case study of La2Zr2O7

    Författare :Joakim Nyman; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; proton; self compensation; hydrogen economy; DFT; La2Zr2O7; acceptor doping; lanthanum zirconate; oxygen vacancy; SOFC; pyrochlore; point defect; trapping; computational methods; solid oxide; charge compensation; first principles; ion conduction; solid oxide fuel cell; ceramic electrolyte; defect cluster; fuel cell; hydrogen;

    Sammanfattning : In the endeavor to attain a clean environment and sustainable energy consumption, the notion of a future hydrogen economy stands out as one of the grandest visions. Striving for this vision, a critical task lies in optimizing the performance of the fuel-cell devices responsible for extracting electric power from the energy stored in hydrogen molecules. LÄS MER

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

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

    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

  5. 19. The Influence of Hydrogen on the Radiolytic Oxidation of UO2

    Författare :Niklas Hansson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; XPS; Dose-Rate; Radiolytic Oxidation; UO2; MOX; Hydrogen Effect;

    Sammanfattning : Spent nuclear fuel from the nuclear fuel cycle contains radiotoxic nuclides which must be safely stored for over 100 000 years. The Swedish final repository concept, KBS-3, is based on engineered and geological barriers that prevent the nuclear fuel from coming in contact with groundwater, which is the most credible vector to transport the radionuclides into the biosphere. LÄS MER

  7. 20. Phase Transitions and Phase Formation of Hydrogen in Quasi-2D Lattices

    Författare :Stefan Olsson; Björgvin Hjörvarsson; Yuh Fukai; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; hydrogen; finite-size effects; long-ranged interactions; superlattices; phase transitions; elastic interaction; Fysik; Physics; Fysik;

    Sammanfattning : The role of the dimensionality and strain state of metallic lattices on the phase behavior of dissolved hydrogen was explored. Metallic superlattices with well defined hydrogen absorption potential on the nm scale, were utilized as test systems. LÄS MER