Search for dissertations about: "Twisting"

Showing result 1 - 5 of 36 swedish dissertations containing the word Twisting.

2. 1. Twisting and Gluing : On Topological Field Theories, Sigma Models and Vertex Algebras

   Author : Johan Källén; Maxim Zabzine; Mathias Blau; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Topological field theory; Chern-Simons theory; Contact geometry; Sigma models; Poisson vertex algebras; Vertex algebras; String theory; Theoretical Physics; Teoretisk fysik;

   Abstract : This thesis consists of two parts, which can be read separately. In the first part we study aspects of topological field theories. We show how to topologically twist three-dimensional N=2 supersymmetric Chern-Simons theory using a contact structure on the underlying manifold. READ MORE

4. 2. Twisting and Turning in Six Dimensions

   Author : Hampus Linander; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; 0 theory; 2; Yang-Mills theory; Topological twisting; Circle fibrations; Compactification; Supersymmetry; Topological field theory;

   Abstract : This thesis investigates certain aspects of a six-dimensional quantum theoryknown as (2,0) theory. This theory is maximally supersymmetric and conformal,making it the most symmetric higher dimensional quantum theory known. It hasresisted an explicit construction as a quantum field theory yet its existence can beinferred from string theory. READ MORE

5. 3. Bending, Twisting and Turning : Protein Modeling and Visualization from a Gauge-Invariance Viewpoint

   Author : Martin Lundgren; Antti Niemi; Jørgen Ellegaard Andersen; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; protein folding; discrete frenet frame; solitons; protein visualization; Physics and Astronomy specializing in Theoretical Physics; Fysik och astronomi med inriktning mot teoretisk fysik;

   Abstract : Proteins in nature fold to one dominant native structure. Despite being a heavily studied field, predicting the native structure from the amino acid sequence and modeling the folding process can still be considered unsolved problems. In this thesis I present a new approach to this problem with methods borrowed from theoretical physics. READ MORE

6. 4. Torque and Angle Controlled Tightening of Bolted Joints

   Author : Göran Toth; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; torque controlled tightening; deformation parameters; momentary elongation; deformation factor; torque; Bolted screwed joints; spring characteristic; Torx; torque and angle controlled tightening; hexalobular; final torque; snug torque; Taylor’s series expansions; preload; plastic deformation; permanent elongation; yield; friction diameter; plastic spring constant; clevis; turn-of-nut method; bearing surface pressure; twisting; Monte-Carlo simulations;

   Abstract : Reduced weight and fuel consumption, improved reliability and engine performance are the main requirements in the automotive industry of today. These requirements demand robust and optimized bolted joints, where a high amount of preload obtained by effective utilisation of the bolt is essential. READ MORE

7. 5. Exploring Organic Dyes for Grätzel Cells Using Time-Resolved Spectroscopy

   Author : Ahmed M. El-Zohry; Burkhard Zietz; Ana Morandeira; Leif Hammarström; Eric Vauthey; Uppsala universitet; []
   Keywords : Laser spectroscopy; DSSCs; DSC; Electron dynamics; Deactivation processes; Isomerization; Twisting; TICT; Quenching by protons; Semiconductor; Electrolyte; Electron injection; Regeneration; Recombination; Chemistry with specialization in Physical Chemistry; Kemi med inriktning mot fysikalisk kemi; Kemi med inriktning mot kemisk fysik; Chemistry with specialization in Chemical Physics;

   Abstract : Grätzel cells or Dye-Sensitized Solar Cells (DSSCs) are considered one of the most promising methods to convert the sun's energy into electricity due to their low cost and simple technology of production. The Grätzel cell is based on a photosensitizer adsorbed on a low band gap semiconductor. READ MORE