Search for dissertations about: "permittivity"

Showing result 11 - 15 of 89 swedish dissertations containing the word permittivity.

2. 11. Dielectric properties of poly(ethyelene-co-butyl acrylate) filled with Alumina nanoparticles

   Author : Nadejda Jäverberg; Hans Edin; Eva Mårtensson; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nanocomposites; poly ethylene-co-butyl acrylate ; EBA; alumina; dielectric permittivity; absorbed water; humidity; temperature; dielectric spectroscopy; partial discharge; electrical treeing; Electrical engineering; Elektroteknik;

   Abstract : In this work dielectric properties of the poly(ethylene-co-butyl acrylate)filled with alumina nanoparticles are evaluated. These nanocomposite materialswere manufactured at the department of Fibre and Polymer Technology,KTH.This study is limited to the properties of general importance for the AC applications. READ MORE

4. 12. Microfluidics at High Pressures : Understanding, Sensing, and Control

   Author : Martin Andersson; Lena Klintberg; Cyril Aymonier; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High-pressure microfluidics; supercritical CO2; compressible flow; relative permittivity; integrated electrodes; Teknisk fysik med inriktning mot mikrosystemteknik; Engineering Science with specialization in Microsystems Technology;

   Abstract : This thesis explores understanding, sensing, and control in high-pressure microfluidics. The high-pressure regime allows fluids to be forced through narrow channels at substantial speed and creates conditions for fluids of high density and low viscosity—features desired in flow-based chemical analyses. READ MORE

5. 13. Electrical Insulating Properties of Poly(Ethylene-co-Butyl Acrylate) Filled with Alumina Nanoparticles

   Author : Nadejda Jäverberg; Hans Edin; John Fothergill; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nanocomposites; poly ethylene-co-butyl acrylate ; EBA; alumina; dielectric permittivity; absorbed water; humidity; temperature; dielectric spectroscopy; breakdown strength; pre-breakdown current;

   Abstract : In this work the electrical insulating properties of the nanocomposite materials based on poly(ethylene-co-butyl acrylate) filled with alumina nanoparticles are studied. The dielectric properties chosen for the evaluation are the dielectric permittivity and loss as well as the breakdown strength and the pre-breakdown currents. READ MORE

6. 14. 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

7. 15. 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