Search for dissertations about: "dielectric effect"

Showing result 1 - 5 of 136 swedish dissertations containing the words dielectric effect.

2. 1. Structures and Properties of Ferroelectric Liquid Crystal Displays

   Author : Marek Matuszczyk; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; smectic; displays; dielectric anisotropy and biaxiality; surface-stabilized structure; dielectric; paraelectric; liquid crystal alignment; electroclinic effect; grey scale; polarization; multiplexing; liquid crystal LC ; orthogonal and tilted phases; chirality; aligning layer; ferroelectric; polyimide; rubbing; light valves and modulators; SSFLC;

   Abstract : Liquid crystals have unique physical properties as they combine the features of solids and liquids. In thermotropic liquid crystals the degree of order varies with temperature resulting in an appearance of intermediate phases. READ MORE

4. 2. Enhanced Dielectric Response Methods for the Characterization of Dielectric Materials

   Author : Jing Hao; Nathaniel Taylor; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; FDS; non-contact; dielectric response; combined AC and DC; space-charge polarization;

   Abstract : Dielectric response measurement is widely used for condition assessment of high voltage equipment and for characterizing candidate materials. Measurement with high accuracy and reliability is important in all stages of the lifetime of high voltage equipment, from manufacture to replacement decision. READ MORE

5. 3. Charge Accumulation in Hybrid High Voltage Insulation

   Author : Mats Sjöberg; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dielectric barrier; charge accumulation; high voltage; dielectric barrier discharge; dielectric coating; hybrid insulation; electric field distribution; discharge modelling; breakdown strength; charge conditioning;

   Abstract : This thesis deals with the novel idea of controlling the electric stress or field distribution in a hybrid air - solid-dielectric high voltage insulation by promoting accumulation of surface charges on the internal interfacial layers in the combined (hybrid) dielectric structure. Primarily, applications are expected to be found in high voltage dc systems and as a method to improve the resistance against insulation failure by overvoltages, e. READ MORE

6. 4. Studies of Dielectric Relaxation in Solid Polymers and Composites

   Author : Mohsen Safari Ardi; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dielectric permittivity; time-domain dielectric relaxation; composite; carbon black; poly vinylidene fluoride ; interfacial polarization; poly vinyl chloride ; coated carbon fibre; epoxy; poly methyl methacrylate ; nitrile butadiene rubber; ethylene-vinyl acetate copolymer; polyamide 6;

   Abstract : Non-linear characteristics of homogeneous solid polymers and solid polymer-based composites have been studied both experimentally and theoretically. In particular experimental studies of non-linear dielectric response of six homogeneous solid polymeric materials and the influence of the composition on the properties of solid polymer-based composites with high dielectric permittivities have been carried out and a theoretical study of dipole-dipole interaction in solids based on a formulation due to P. READ MORE

7. 5. Electron transport properties of graphene and graphene field-effect devices studied experimentally

   Author : Youngwoo Nam; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; dual-gated graphene field effect devices; thermopower; quantum Hall effect; graphene; Aharonov-Bohm effect; chemical vapour deposition;

   Abstract : This thesis contains experimental studies on electronic transport properties of graphene with the Aharonov-Bohm (AB) effect, thermopower (TEP) measurements, dual-gated graphene field effect devices, and quantum Hall effect (QHE). Firstly, in an effort to enhance the AB effect in graphene, we place superconducting-metal (aluminium) or normal-metal (gold) mirrors on the graphene rings. READ MORE