Sökning: "bulk conductivity"

Visar resultat 11 - 15 av 105 avhandlingar innehållade orden bulk conductivity.

  1. 11. Development and Characterisation of Cathode Materials for the Molten Carbonate Fuel Cell

    Författare :Athula Wijayasinghe; KTH; []
    Nyckelord :molten carbonate fuel cell MCFC ; MCFC cathode; LiFeO2-LiCoO2-NiO ternary compositions; electrical conductivity; porous gas diffusion electrodes; polarization; electrochemical performance; post-cell characterization;

    Sammanfattning : Among the obstacles for the commercialization of the MoltenCarbonate Fuel Cell (MCFC), the dissolution of thestate-of-the-art lithiated NiO cathode is considered as aprimary lifetime limiting constraint. Development ofalternative cathode materials is considered as a main strategyfor solving the cathode dissolution problem. LÄS MER

  3. 12. Surface potential dynamics on insulating polymers for HVDC applications

    Författare :Shahid Alam; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dielectric spectroscopy; silicone rubber; intrinsic conduction; surface potential decay; activation energy; electric conductivity; HVDC insulation;

    Sammanfattning : The use of high voltage direct current (HVDC) technology in power transmission systems is continuously expanding. Nowadays, HVDC transmissions operate at voltages up to 800 kV and higher levels are being developed. LÄS MER

  4. 13. Surface Charge Dynamics on Polymeric Insulating Materials for High Voltage Applications

    Författare :Shahid Alam; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HVDC insulation.; gas neutralization; decay rate; Surface charging; electrical conductivity; surface potential; charge transport; ambient pressure;

    Sammanfattning : To meet increasing demands in electric energy, it is essential to enhance production of electricity from renewable energy sources (solar, wind and hydro). Such generation sites, however, are usually separated from consumption sites by long distances. LÄS MER

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

    Författare :Tuan Anh Hoang; Chalmers tekniska högskola; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  7. 15. Conceptualization of solute transport using time domain reflectometry. A combined laboratory and field study

    Författare :Magnus Persson; Avdelningen för Teknisk vattenresurslära; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hydrogeologi; geographical and geological engineering; Hydrogeology; electrical conductivity; Solute transport; unsaturated zone; teknisk geologi; teknisk geografi; Geophysics; physical oceanography; meteorology; Geofysik; fysisk oceanografi; meteorologi;

    Sammanfattning : Solute transport in the unsaturated zone is a complex process. The first of the two objectives for this study was to examine how it could be conceptualized under different flow conditions. LÄS MER