Search for dissertations about: "variational calculations"

Showing result 1 - 5 of 16 swedish dissertations containing the words variational calculations.

2. 1. Statistical Mechanical Studies of Titrating Polyelectrolytes

   Author : Magnus Ullner; Kemiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; integral equation theory; variational calculations; Monte Carlo simulations; end-to-end separation; apparent dissociation constant; titrating polyelectrolytes; electrostatic interactions; Physical chemistry; Fysikalisk kemi;

   Abstract : Different models and statistical mechanical approximations for titrating polyelectrolytes are studied and the results compared with Monte Carlo simulations and experimental data. Three types of models have been used in the simulations: i) rigid structures and freely jointed chains with ii) rigid bonds and iii) flexible, harmonic bonds. READ MORE

4. 2. New Approaches to Large-Scale Electronic Structure Calculations

   Author : Francesco Aquilante; Beräkningskemi; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Theoretical chemistry; orbital localization; electron correlation; analytic gradients; Cholesky decomposition; density fitting; quantum chemistry; Teoretisk kemi; kvantkemi;

   Abstract : Recent years have witnessed a growing interest of the scientific community for the use of ab initio and density functional theory methods in theoretical studies of molecules containing many atoms. However, the `scaling wall' of some of the most accurate of such methods is often an obstacle for their applicability to systems of real-life interest, e. READ MORE

5. 3. Static and Dynamic Correlation Effects in Atoms

   Author : Nils-Erik Dahlen; Matematisk fysik; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; magnetic and optical properties; electrical; Condensed matter:electronic structure; relaxation; magnetic resonance; supraconductors; spectroscopy; Kondenserade materiens egenskaper:elektronstruktur; Atom- och molekylärfysik; Atomic and molecular physics; spektroskopi; magnetisk resonans; egenskaper elektriska; supraledare; magnetiska och optiska ; variational energies; double ionization; Electron correlation; laser-atom interaction; Fysicumarkivet A:2002:Dahlen; conserving approximations; Green s functions; GW-approximation;

   Abstract : The thesis considers the effects of electron correlation by studying the two opposite limits of atoms in the ground state and atoms in strong laser pulses. Computational methods and theoretical approaches differ significantly due to the different physical processes that are studied in these two cases. READ MORE

6. 4. Adaptive Finite Element Methods for the Reynolds Thin Film Model with Cavitation

   Author : Bertil Nilsson; Sweden Gothenburg Chalmers University of Technology Department of Applied Mechanics; []
   Keywords : tribology; Reynolds equation; cavitation; FEM; adaptivity; variational inequality; penalty formulation; error estimation; residual; duality;

   Abstract : The main purpose of this thesis is to use modern goal-oriented adaptive finite element techniques in order to improve the numerical simulation of tribology. Two novel adaptive finite element methods for the Reynolds thin film model including cavitation are presented and their different strategies are compared. READ MORE

7. 5. Finite element procedures for virtual tribology

   Author : Bertil Nilsson; Göteborgs universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Tribology; Reynolds equation; Stokes equation; cavitation; FEM; adaptivity; variational inequality; penalty formulation; error estima- tion; residual; duality.;

   Abstract : The main purpose of this thesis is to use modern goal-oriented adap- tive finite element techniques in order to improve the numerical simulation of tribology. Two novel adaptive finite element methods for the Reynolds thin film model, and Stokes model including cavitation are presented and their different strategies are compared. READ MORE