Sökning: "physical model"

Visar resultat 1 - 5 av 3585 avhandlingar innehållade orden physical model.

  1. 1. Atomic Scale Degradation of Zirconium Alloys for Nuclear Applications

    Författare :Gustav Sundell; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Irradiation damage; Hydrogen microanalysis; Hydrogen pick-up; Zirconium alloys; Atom probe tomography; Corrosion;

    Sammanfattning : Due to their low thermal neutron capture cross-section, zirconium alloys are widely used in the nuclear industry as fuel cladding and for structural components. The lifetime of the fuel assemblies in the reactors is primarily dictated by the ability of the cladding to withstand oxidation and hydrogen pick-up from the coolant water and radiation damage induced by the neutron flux. LÄS MER

  3. 2. Nanostructured Model Electrodes for Studies of Fuel Cell Reactions

    Författare :Björn Wickman; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Oxygen Reduction; Hydrogen Oxidation; Degradation; PEMFC; Model System; Nanofabrication; Fuel Cell; Catalyst; Electrode;

    Sammanfattning : There is currently a general need for alternative and sustainable energy systems. As part of such a system, the polymer electrolyte fuel cell (PEMFC) offers efficient and emission free energy conversion. LÄS MER

  4. 3. Microkinetic Modeling of Nanoparticle Catalysis using Density Functional Theory

    Författare :Mikkel Jørgensen; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Density Functional Theory; Methane oxidation; Mean-field approximation; Microkinetic modeling; Kinetic Monte Carlo; Nanoparticles; Entropy; CO oxidation; Catalysis;

    Sammanfattning : Heterogeneous catalysis is vitally important to modern society, and one path towardsrational catalyst design is through atomistic scale understanding. The atomistic scalecan be linked to macroscopic observables by microkinetic models based on first-principlescalculations. LÄS MER

  5. 4. Hydrological aspects of the carbon balance in a boreal catchment: A model study

    Författare :Alla Yurova; Institutionen för naturgeografi och ekosystemvetenskap; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cartography; pedology; geomorphology; Physical geography; boreal peatland; dissolved organic carbon; ecohydrology; model; climatology; Fysisk geografi; geomorfologi; marklära; kartografi; klimatologi;

    Sammanfattning : AbstractThe cycling of carbon in its gaseous, solid and dissolved forms is of central importance to ecosystem science, particularly, when the natural carbon cycle has been perturbed by human activity. Mathematical models are commonly used to asses and predict global and regional patterns of terrestrial carbon exchange. LÄS MER

  7. 5. The Role of Molecular Heterogeneity in the Structural Dynamics of Aqueous Solutions

    Författare :Sharon Berkowicz; Fivos Perakis; Giulio Monaco; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Water; Aqueous solutions; X-ray scattering; X-ray photon correlation spectroscopy; Dynamic light scattering; kemisk fysik; Chemical Physics;

    Sammanfattning : The liquid-liquid critical point hypothesis suggests that liquid water exists in two liquid states with different local structures, so-called high- and low-density liquid (HDL, LDL). At ambient pressure water locally fluctuates between these two states, with the fluctuations becoming more pronounced as the liquid is supercooled. LÄS MER