Sökning: "permittivity"

Visar resultat 16 - 20 av 90 avhandlingar innehållade ordet permittivity.

1. 16. Studies of Dielectric Relaxation in Solid Polymers and Composites

   Författare :Mohsen Safari Ardi; Chalmers tekniska högskola; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

3. 17. On-chip terahertz characterisation of liquids

   Författare :Juan Cabello Sánchez; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dielectric permittivity; Through-Reflect-Line TRL calibration; vector network analyzers VNA ; terahertz spectroscopy; isopropyl alcohol IPA ; coplanar waveguides CPW ; water; on-wafer measurements; planar Goubau line; Chip; liquids; microfluidic channels; scattering parameters; material properties;

   Sammanfattning : Spectroscopy at terahertz frequencies can be used in a wide range of applications including radio-astronomy, pharmaceutical manufacturing control, and the study of processes in molecular biology. Biomolecular samples should preferably be studied in their native environment, water, however, water poses extreme attenuation for THz-frequency waves, deteriorating or even impeding analysis using these waves. LÄS MER

4. 18. Optical and electrical properties of some inhomogeneous materials used for energy efficient applications

   Författare :Torbjörn M. J. Nilsson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; inhomogenous material; optical characterisation; thin film technology; energy-efficiency; scattering; pigmented foil; equivalent cirquit; sputtering; selective film; impedence spectroscopy; optical properties; pigment; dielectric permittivity; four flux theory; radiative cooling; smart window; electrochromism; polaron; Lorenz-Mie; nickeloxide; selective coating; Maxwell Garnett;

   Sammanfattning : .... LÄS MER

5. 19. Dielectric and Conductivity Studies of Polymer Electrolytes

   Författare :Ingvar Albinsson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Dielectric and conductivity studies has been performed in order to study the microscopic structure and dynamics of ion conducting polymers. The investigated systems are various salts, e.g. LiCF3SO3, dissolved in poly(ethylene glycol), poly(propylene glycol) or copolymers which partly consists of these polymers. LÄS MER

7. 20. Efficient Adaptive Algorithms for an Electromagnetic Coefficient Inverse Problem

   Författare :John Bondestam Malmberg; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; coefficient inverse problem; inverse scattering; Maxwell’s equations; approximate global convergence; finite element method; adaptivity; ; a posteriori error analysis;

   Sammanfattning : This thesis comprises five scientific papers, all of which are focusing on the inverse problem of reconstructing a dielectric permittivity which may vary in space inside a given domain. The data for the reconstruction consist of time-domain observations of the electric field, resulting from a single incident wave, on a part of the boundary of the domain under consideration. LÄS MER