Sökning: "stoichiometric"

Visar resultat 11 - 15 av 187 avhandlingar innehållade ordet stoichiometric.

  1. 11. Calculations of Linear and Nonlinear Optical Properties of Ionic Crystal Surfaces and Fullerenes

    Författare :Erik Westin; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Electronic and optical properties of ionic crystal surfaces and fullerenes have been studied by means of cluster calculations based on the Local Density Approximation (LDA) method using a numerical LCAO approach. The calculations for the bulk, stoichiometric and non-stoichiometric (111) surfaces of the divalent ionic crystals, CaF2 and BaF2, were based on the construction of an appropriate cluster of Ba++/Ca++ and F- ions representing a local environment of the specific system. LÄS MER

  3. 12. Nutrient Stoichiometry in Benthic Food Webs – Interactions Between Algae, Herbivores and Fish

    Författare :Antonia Liess; Peter Eklöv; Dag Hessen; Uppsala universitet; []
    Nyckelord :Ecology; ecologial stoichiometry; periphyton; grazer; benthos; trophic interactions; nutrient; algae; Ekologi;

    Sammanfattning : The aim of this thesis was to identify general structuring mechanisms in benthic food webs within the framework of ecological stoichiometry theory. Ecological stoichiometry is defined as the balance of multiple chemical substances in ecological interactions and explicitly considers the combined dynamics of key elements such as carbon (C), nitrogen (N) and phosphorus (P). LÄS MER

  4. 13. Experimental studies of radiation-induced dissolution of UO2 : The effect of intrinsic solid phase properties and external factors

    Författare :Alexandre Barreiro Fidalgo; Mats Jonsson; David Shoesmith; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Oxidation; dissolution; uranium dioxide; gadolinium; bentonite; sulfide; hydrogen; gamma radiation; radiolysis; hydrogen peroxide; hydroxyl radical; repository; Kemi; Chemistry;

    Sammanfattning : Dissolution of the UO2 matrix is one of the potential routes for radionuclide release in a future deep geological repository for spent nuclear fuel. This doctoral thesis focuses on interfacial reactions of relevance in radiation-induced dissolution of UO2 and is divided in two parts:In the first part, we sought to explore the effects of solid phase composition:The impact of surface stoichiometry on the reactivity of UO2 towards aqueous radiolytic oxidants was studied. LÄS MER

  5. 14. Structure and Properties of Perovskite SrTiO3 and Na0.5K0.5NbO3 Thin Films Fabricated by rf Magnetron Sputtering

    Författare :Xin Wang; Eric Cross; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Functional oxide thin films are getting more and more attention due to their unique dielectric, piezoelectric, ferroelectric, magnetic, superconducting properties. This thesis focuses on the growth, compositional control, and structure-property relationships of SrTiO3 and Na0.5K0.5NbO3 thin films. LÄS MER

  7. 15. Diluted Operation of a Heavy-Duty Natural-gas Engine

    Författare :Mehrzad Kaiadi; Förbränningsmotorer; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Fuel economy and emissions are the two central parameters in heavy duty engines; most of the existing heavy duty engines are run with diesel. The overall efficiency of diesel engines is good however they suffer from high levels of emissions mainly NOX and soot. LÄS MER