Sökning: "Yttrium"

Visar resultat 21 - 25 av 55 avhandlingar innehållade ordet Yttrium.

  1. 21. Novel Insights into the Oxidation of High Temperature Alloys - The Role of Environment, Microstructure and Reactive elements

    Författare :Nooshin Mortazavi Seyedeh; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; reactive elements; nitridation; High temperature materials; nitrides; alumina; hydrides; microstructure; chromia; oxidation;

    Sammanfattning : The properties of materials can be deteriorated, when they react with an environment at high temperature and form various types of corrosion products, such as oxides and nitrides. In order to perform successfully at elevated temperatures, all these materials are required to be protected by a slow-growing, continuous and adherent surface oxide layer. LÄS MER

  3. 22. Reactive Sputtering of Complex Multi-component Nitride Thin Films

    Författare :Kristina von Fieant; Erik Lewin; Ulf Jansson; Jean-Francois Pierson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The ever-increasing demand on improvement of protective nitride thin films has led to an expansion of the research field into multi-element based materials. The work in this thesis has focused on exploring new complex, multi-component nitride thin films based on three different material systems: Al-Ge-N, Hf-Nb-Ti-V-Zr-N and Al-Cr-Nb-Y-Zr-N. LÄS MER

  4. 23. Bismuth iron garnet films for magneto-optical photonic crystals

    Författare :Sören Kahl; KTH; []
    Nyckelord :Faraday effect; iron garnet; pulsed laser deposition; photonic crystals;

    Sammanfattning : The thesis explores preparation and properties of bismuthiron garnet (BIG) films and the incorporation of BIG films intoone-dimensional magneto-optical photonic crystals (MOPCs). Films were prepared by pulsed laser deposition. LÄS MER

  5. 24. Robust Multi-objective Optimization of Rare Earth Element Chromatography

    Författare :Hans-Kristian Knutson; Avdelningen för kemiteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Chromatography; Rare earth elements; Modeling; Multi-objective optimization; Robust optimization; Chromatography; Rare earth elements; Modeling; Multi-objective optimization; Robust optimization;

    Sammanfattning : Rare earth elements comprise the metallic elements known as lanthanides as well as scandium and yttrium. They are extensively used in modern technological industries and are considered as strategic commodities in many countries. LÄS MER

  7. 25. Microbially mediated formation of birnessite-type manganese oxides and subsequent incorporation of rare earth elements, Ytterby mine, Sweden

    Författare :Susanne Sjöberg; Christophe Dupraz; Rienk Smittenberg; Volker Brüchert; Helena Filipsson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; microbial diversity; manganese oxides; birnessite; rare earth elements; subterranean; Ytterby mine; geokemi; Geochemistry;

    Sammanfattning : Microbes exert extensive control on redox element cycles. They participate directly orindirectly in the concentration and fractionation of elements by influencing the partitioningbetween soluble and insoluble species. LÄS MER