Sökning: "uppsala 2010"

Visar resultat 16 - 20 av 446 avhandlingar innehållade orden uppsala 2010.

  1. 16. Density Functional Theory Studies of Small Supported Gold Clusters and Related Questions : What a Difference an Atom Makes

    Författare :Martin Amft; Natalia Skorodumova; Olle Eriksson; Hannu Häkkinen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Gold clusters; CO oxidation; graphene; spin-orbit coupling; van der Waals interactions; thermally excited vibrations; Condensed matter physics; Kondenserade materiens fysik; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : During the last decades the specific manipulation of matter on the (sub-) nanometer scale, also known as nanoscience, became possible by technologies such as the scanning tunneling microscope. Nanocatalysts, i.e. catalytic active structures of up to a few nanometers in size, belong to this rather new class of materials. LÄS MER

  3. 17. Bacterial Degradation and Use of Chitin in Aquatic Habitats

    Författare :Sara Beier; Stefan Bertilsson; Ian Head; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chitin; organic matter degradation; microbial ecology; functional guild; Biology; Biologi;

    Sammanfattning : Chitin belongs to the most abundant biopolymers on earth where it has an important role as a structural element in crustaceans, insects, fungi and some phytoplankton. Missing evidence for long-term accumulation of chitin in nature implies fast turnover and as chitin is composed of aminosugar subunits it holds central roles in both carbon and nitrogen cycles. LÄS MER

  4. 18. Insights into Materials Properties from Ab Initio Theory : Diffusion, Adsorption, Catalysis & Structure

    Författare :Andreas Blomqvist; Rajeev Ahuja; Christopher Wolverton; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Density functional theory; Molecular dynamics; Diffusion; Catalysis; Adsorption; Random structure search; Hydrogen-storage materials; Phase-change materials; Defects and diffusion; Defekter och diffusion; Surfaces and interfaces; Ytor och mellanytor; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : In this thesis, density functional theory (DFT) calculations and DFT based ab initio molecular dynamics simulations have been employed in order to gain insights into materials properties like diffusion, adsorption, catalysis, and structure. In transition metals, absorbed hydrogen atoms self-trap due to localization of metal d-electrons. LÄS MER

  5. 19. Multipoles in Correlated Electron Materials

    Författare :Francesco Cricchio; Lars Nordström; Peter Oppeneer; Igor Solovyev; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; correlated electrons; magnetic ordering; multipoles; actinides; hidden order; high temperature superconductors; Fe pnictides; electronic structure calculations; Condensed matter physics; Kondenserade materiens fysik; Superconductivity; Supraledning; Electronic structure; Elektronstruktur; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : Electronic structure calculations constitute a valuable tool to predict the properties of materials. In this study we propose an efficient scheme to study correlated electron systems with essentially only one free parameter, the screening length of the Coulomb potential. LÄS MER

  7. 20. Processes of Magma-crust Interaction : Insights from Geochemistry and Experimental Petrology

    Författare :Frances M Deegan; Valentin R Troll; Luigi Dallai; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Canary Island magmatism; HP-HT experimental petrology; magma-crust interaction; Merapi volcano; radiogenic isotopes Sr; Nd; Pb ; stable isotopes O; B .; Solid earth geology and petrology; Berggrundsgeologi och petrologi; Geovetenskap med inriktning mot mineralogi; petrologi och tektonik; Earth Science with specialization in Mineral Chemistry; Petrology and Tectonics;

    Sammanfattning : This work focuses on crustal interaction in magmatic systems, drawing on experimental petrology and elemental and isotope geochemistry. Various magma-chamber processes such as magma-mixing, fractional crystallisation and magma-crust interaction are explored throughout the papers comprising the thesis. LÄS MER