Search for dissertations about: "first-principle calculations"

Showing result 11 - 15 of 38 swedish dissertations containing the words first-principle calculations.

  2. 11. Understanding Physical Reality via Virtual Experiments

    Author : Sergiu Arapan; Rajeev Ahuja; Börje Johansson; Chris Pickard; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; density functional theory; ab initio calculations; electronic structure; lattice dynamics; high-pressure phase transitions; high-temperature phase transitions; incommensurate structures; Condensed matter physics; Kondenserade materiens fysik;

    Abstract : In this thesis I have studied some problems of condensed matter at high pressures and temperatures by means of numerical simulations based on Density Functional Theory (DFT).The stability of MgCO3 and CaCO3 carbonates at the Earth's mantle conditions may play an important role in the global carbon cycle through the subduction of the oceanic crust. READ MORE

  4. 12. Chemical Transformation of Inorganic Species in Thermochemical Conversion of Waste-Derived Fuels - The Role of Oxygen Carriers

    Author : Ivana Stanicic; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; oxygen carriers; Waste-derived fuels; thermodynamic equilibrium calculations; heavy metals; chemical looping;

    Abstract : Waste-derived fuels are used increasingly in heat and power production systems in Sweden. Thermal conversion of waste-derived and biomass fuels offers the possibility of achieving carbon dioxide-neutral or even negative emissions. To limit global warming, it is essential to integrate these systems with carbon capture and storage. READ MORE

  5. 13. Helium in CERMET fuel - binding energies and diffusion

    Author : Odd Runevall; Janne Wallenius; Pavel Korzhavy; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Condensed matter physics; Kondenserade materiens fysik;

    Abstract : This thesis presents a first principle approach to model helium diffusionand retention in molybdenum. Results from electron structure calculations within the framework of density functional theory are used to assess parameters in a rate theory model. READ MORE

  6. 14. Formation stability and electronic structure of surfaces and interfaces from first principles

    Author : Jochen Rohrer; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; band structure; van der Waals interaction; electronic structure; graphane; graphene; atomic structure; growth; thin film; interface; density functional theory; CVD; Alumina; nucleation;

    Abstract : This thesis deals with two closely interwoven aspects of first-principle(density functional theory) materials modeling:(1)~prediction of atomic structure & chemical composition,and (2)~prediction of electronic properties.In the first part, we focus on atomic structure (AS) and chemical composition (CC) of surface and interface systems. READ MORE

  7. 15. Metastable YAlN and ScAlN thin films : growth and characterization

    Author : Agnė Žukauskaitė; Lars Hultman; Jens Birch; Anita Lloyd Spetz; Linköpings universitet; []
    Keywords : ;

    Abstract : ScxAl1-xN and YxAl1-xN thin films were deposited in a ultra high vacuum system using reactive magnetron co-sputtering from elemental Al, Sc and Y targets in Ar/N2. Their mechanical, electrical, optical, and piezoelectrical properties were investigated with the help of transmission electron microscopy, xray diffraction, ellipsometry, I-V and C-V measurements, and two different techniques for piezoelectric characterization: piezoresponse force microscopy and double beam interferometry. READ MORE