Search for dissertations about: "dielectric permittivity"

Showing result 11 - 15 of 56 swedish dissertations containing the words dielectric permittivity.

  2. 11. Enhancements in Dielectric Response Characterization of Insulation Materials

    Author : Xiangdong Xu; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; harmonic limited waveform; air reference method; contact-free electrode; geometric corrections.; frequency domain spectroscopy; Dielectric characterization;

    Abstract : The increasing demand of integrating various renewable energy recourses in power system requires extensive use of power electronic solutions, such as HVDC and FACTS, as these techniques allow energy conversion between different frequencies and serves to stabilize the network. Consequently, electric stresses other than traditional 50/60 Hz sinusoidal voltage stress are acting on high voltage insulation materials. READ MORE

  4. 12. Microwave Measurement Systems for In-line 3D Monitoring of Pharmaceutical Processes

    Author : Livia Cerullo; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; permittivity; moisture content; microcrystalline cellulose; Pharmaceutical processes; dispersive media; finite element method; microwave measurements;

    Abstract : The monitoring and understanding of pharmaceutical processes are important in order to achieve high-quality products at a low-production cost. The presence of water, e.g. as moisture content in the solid-state pharmaceutical material, is ofparticular interest and importance. READ MORE

  5. 13. Electrical Characterization of Partial Discharge Resistant Enamel Insulation

    Author : Tuan Anh Hoang; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Enamel wire insulation; dipolar polarization; charge injection; charge transport; chromium oxide; dc conductivity; partial discharge; twisted pair.; dielectric permittivity;

    Abstract : Adjustable speed drives for rotating machines have become increasingly popular as they provide possibilities of smooth and accurate process control as well as for energy savings. In such systems, due to the fact that the voltage applied at terminals of motor windings is no longer purely sinusoidal but characterized by a high content of harmonics, the appearing electrical and thermal stresses yield premature failures of the winding insulation, mainly because of an increased partial discharge (PD) activity. READ MORE

  6. 14. On-chip terahertz characterisation of liquids

    Author : Juan Cabello Sánchez; Chalmers tekniska högskola; []
    Keywords : 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;

    Abstract : 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. READ MORE

  7. 15. Optical and electrical properties of some inhomogeneous materials used for energy efficient applications

    Author : Torbjörn M. J. Nilsson; Chalmers tekniska högskola; []
    Keywords : 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;

    Abstract : .... READ MORE