Sökning: "DENSITY-FUNCTIONAL-THEORY"

Visar resultat 16 - 20 av 581 avhandlingar innehållade ordet DENSITY-FUNCTIONAL-THEORY.

1. 16. Materials Engineering Using Density Functional Theory

   Författare :Adrian Taga; KTH; []
   Nyckelord :condensed matter; electricity and magnetism;

   Sammanfattning : This doctoral thesis presents density functionalcalculations applied in several domains of interest in solidstate physics and materials science. Non-collinear magnetismhas been studied both in an artificial multi-layer structure,which could have technological relevance as a magnetic sensordevice, and as excitations in 3d ferromagnets. LÄS MER

3. 17. Density functional theory applied to phosphorescence

   Författare :Ingvar Tunell; KTH; []
   Nyckelord :;

   Sammanfattning : .... LÄS MER

4. 18. Vibrational and Structural Characterisation in Two Perovskite Challenges: A Density Functional Theory Study

   Författare :Erik Jedvik Granhed; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; phonon; chemical expansion; materials modelling; oxyhydride; polaron; vibrational analysis; BaTiO3; BaZrO3; anti-ferrodistortive; density functional theory;

   Sammanfattning : The modelling of perovskites using density functional theory (DFT) can sometimes be a challenge with many different states very close in energy. In particular, the tilting of the inscribed octahedron, as well as the formation of electron polarons, leads to states with energy differences in the meV range. LÄS MER

5. 19. Interfacial properties of calcium montmorillonite in aqueous solutions : Density functional theory and classical molecular dynamics studies on the electric double layer

   Författare :Guomin Yang; Göran Lindbergh; Ivars Neretnieks; Michael Holmboe; Jan Forsman; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Clay minerals; Bentonite; density functional theory; molecular dynamics; GROMACS; electric double layer; electrolytes; ionic liquids; primitive model; CLAYFF forcefield.; Chemical Engineering; Kemiteknik;

   Sammanfattning : The swelling properties of Bentonite are highly affected by clay content and the clay-water interactions that arise from the ion distribution in the diffuse double layer formed near the charged montmorillonite (or smectite) surfaces. Existing continuum models describing the electric double layers, such as classical Poisson-Boltzmann and DLVO theory, ignore the ion-ion correlations, which are especially important for multivalent ions at high surface charge and ionic strength. LÄS MER

7. 20. Micro-reaction Mechanism Study of the Biomass Thermal Conversion Process using Density Functional Theory

   Författare :Xiaolei Zhang; Weihong Yang; Linda J. Broadbelt; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; biomass thermal conversion; cellulose pyrolysis; char steam gasification; adsorption; interaction; mechanism; quantum chemistry; density functional theory;

   Sammanfattning : Biomass, or bio-energy, is one of the most important alternative energies because of environmental concerns and the future shortage of fossil fuels. Multi-scaled bioenergy studies have been performed in the division of Energy and Furnace Technology, which included studies of macroscopic systems such as systems and reactors, modeling of computational fluid dynamics (CFD), and atomic/molecular level studies. LÄS MER