Search for dissertations about: "electrostatic potential charges"

Showing result 1 - 5 of 18 swedish dissertations containing the words electrostatic potential charges.

  2. 1. Theoretical studies of porphyrin proteins

    Author : Emma Sigfridsson; Beräkningskemi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; molecular mechanics; quantum chemical calculations; electrostatic potential charges; atomic charges; ferrochelatase; cytochrome; myoglobin; Porphyrin; haem; QM MM; reorganisation energy; Theoretical chemistry; quantum chemistry; Teoretisk kemi; kvantkemi;

    Abstract : Different aspects of porphyrin proteins have been studied with theoretical methods. For example, we have studied: - The importance of hydrogen bonds for the discrimination between carbon monoxide and molecular oxygen by myoglobin, the oxygen carrier in muscles, modelling the active site both in vacuum and in the protein matrix - The inner-sphere reorganisation energy during electron transfer for cytochromes compared to other electron-transfer proteins, such as blue copper proteins and Fe-S clusters - The role of porphyrin distortions in the reaction mechanism of ferrochelatase, the enzyme that inserts an iron ion into protoporphyrin IX to make haem - The interaction between different metal sites in ferrochelatase In these studies we have used density functional theory, classical force field methods, and a combination of quantum chemistry and molecular mechanics. READ MORE

  4. 2. Structural, Kinetic and Thermodynamic Aspects of the Crystal Polymorphism of Substituted Monocyclic Aromatic Compounds

    Author : Michael Svärd; Åke Rasmuson; Hugo Meekes; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Polymorphism; crystallization; thermodynamics; kinetics; nucleation; crystallography; solubility; phase equilibria; polymorphic transformation; solution history; metastable zone; classical theory of nucleation; two-step theory of nucleation; cluster; crystal structure prediction; lattice energy; molecular mechanics; force field; electrostatic potential; potential energy hypersurface; m-aminobenzoic acid; m-hydroxybenzoic acid; Chemical engineering; Kemiteknik;

    Abstract : This work concerns the interrelationship between thermodynamic, kinetic and structural aspects of crystal polymorphism. It is both experimental and theoretical, and limited with respect to compounds to substituted monocyclic aromatics. READ MORE

  5. 3. Surface potential dynamics on insulating polymers for HVDC applications

    Author : Shahid Alam; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dielectric spectroscopy; silicone rubber; intrinsic conduction; surface potential decay; activation energy; electric conductivity; HVDC insulation;

    Abstract : The use of high voltage direct current (HVDC) technology in power transmission systems is continuously expanding. Nowadays, HVDC transmissions operate at voltages up to 800 kV and higher levels are being developed. READ MORE

  6. 4. The Klimontovich description of complex plasma systems : Low frequency electrostatic modes, spectral densities of fluctuations and collision integrals

    Author : Panagiotis Tolias; Lars Blomberg; Carmine Castaldo; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; complex plasmas; dusty plasmas; Klimontovich equations; kinetic theory; dust acoustic waves; collision integrals;

    Abstract : Plasmas seeded with solid particulates of nanometer to micron sizes (complex plasma systems) are a ubiquitous feature of intergalactic, interstellar and planetary environments but also of plasma processing applications or even fusion devices. Their novel aspects compared with ideal multi-component plasmas stem from (i) the large number of elementary charges residing on the grain surface, (ii) the variability of the charge over mass ratio of the dust component, (iii) the inherent openness and dissipative nature of such systems. READ MORE

  7. 5. Development of Protein-Functionalized Magnetic Iron Oxide Nanoparticles: Potential Application in Water Treatment

    Author : Chuka Okoli; Gunaratna Kuttuva Rajarao; M. Arturo López-Quintela; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : The treatment of water to make it safe for human consumption is a problem of immense concern, both in developing and developed countries. However, the production of clean water with chemicals as coagulants has several drawbacks associated with cost, health risks and complexity in sludge management. READ MORE