Sökning: "diffusion theory"

Visar resultat 1 - 5 av 309 avhandlingar innehållade orden diffusion theory.

  1. 1. 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

  3. 2. Theory of Hydrogen Quantum Diffusion

    Författare :Thomas Mattsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; path-integrals; isotope effect; transition state theory; quantum; diffusion; hydrogen; first-principles calculations; nickel;

    Sammanfattning : Atomic hydrogen adsorbed on a metal surface is one of the simplest possible examples of chemisorption, yet it is very challenging. The adsorption and the very elementary process of surface diffusion, a single atomic jump, have been investigated theoretically using several methods. LÄS MER

  4. 3. Ecostrategies in theory and practice : Farmer's perspectives on water, nutrients and sustainability in low-resource agriculture in the dry zone of Sri Lanka

    Författare :Klas Sandell; Linköpings universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Attitudes towards nature; Alternative development; Carrying capacity; Development strategies; Development theory; Diffusion; Dry zone of Sri Lanka; Ecodevelopment; Ethnoperspective; Fertilizers; Green revolution; Human ecology; Human geography; Low-resource agriculture; Small-scale farming; Sustainable development; Village irrigation.; INTERDISCIPLINARY RESEARCH AREAS; TVÄRVETENSKAPLIGA FORSKNINGSOMRÅDEN;

    Sammanfattning : PROBLEMThe need for a sustainable man - nature relationship has long been a neglected aspect of development theory. The increasing awareness of this negligence has led to a search for development strategies alternative to conventional industrial growth. LÄS MER

  5. 4. Energy Storage Materials: Insights From ab Initio Theory : Diffusion, Structure, Thermodynamics and Design

    Författare :Rafael Barros Neves de Araújo; Rajeev Ahuja; Graeme Henkelman; Uppsala universitet; []
    Nyckelord :Density Functional Theory; Defects Diffusion; Thermodynamics and Batteries.;

    Sammanfattning : The development of science and technology have provided a lifestyle completely dependent on energy consumption. Devices such as computers and mobile phones are good examples of how our daily life depends on electric energy. LÄS MER

  7. 5. Quantitative methods for diffusion measurements in fluorescence microscopy

    Författare :Marco Longfils; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cross-validation.; single particle tracking; Confocal laser scanning microscopy; raster scan; correlation spectroscopy; mixture models; diffusion;

    Sammanfattning : In this work, statistical methods are developed for mapping mass transport locally based on images collected using a confocal laser scanning microscope. Besides presenting raster image correlation spectroscopy as an established method in fluorescence microscopy, we introduce a single particle tracking method which takes advantage of the raster scanning of the image in a confocal microscope. LÄS MER