Sökning: "surface charge"

Visar resultat 1 - 5 av 592 avhandlingar innehållade orden surface charge.

1. 1. Electrical Charges on Polymeric Insulator Surfaces and their Impact on Flashover Performance

   Författare :Sarath Kumara; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; streamer criterion; polymeric insulation; flashover voltage; surface potential; bulk conductivity; surface conduction; humidity; bulk neutralization; charge decay; Surface charge; silicone rubber; corona charging; gas neutralization;

   Sammanfattning : Utilization of remotely located sustainable energy resources such as solar, wind and hydro calls for further developments of long-distance electric power transmissions operating at ultra-high voltage (UHV) levels which may exceed 1000 kV ac and 800 kV dc utilized today. It is foreseen that insulation of such transmission systems is to be based on polymeric materials that can provide a number of technical benefits over traditionally used glass and porcelain based insulation. LÄS MER

3. 2. 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

4. 3. Adsorption of surface active elements on the iron (100) surface : A study based on ab initio calculations

   Författare :Weimin Cao; Seshadri Seetharaman; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sulfur; oxygen; surface adsorption; iron surface; ab initio calculations; adsorption energy; work function; difference charge density; thermodynamic stability; average velocity; Materials science; Teknisk materialvetenskap;

   Sammanfattning : In the present work, the structural, electronic properties, thermodynamic stability and adatom surface movements of oxygen and sulfur adsorption on the Fe surface were studied based on the ab initio method. Firstly, the oxygen adsorbed on the iron (100) surface is investigated at the three adsorption sites top, bridge and hollow sites, respectively. LÄS MER

5. 4. Charge transport in polymer-based insulating materials for high voltage applications: effect of single- and multi-layered structures

   Författare :Tuan Anh Hoang; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; charge trapping and de-trapping; polyethylene; surface potential decay; enamel insulation; charge transport; charging current; charge injection; charge mobility; DC conductivity; nanocomposite;

   Sammanfattning : Polymer composites have been widely employed as electrical insulating materials for high voltage components and devices such as power cables, gas-insulated systems, rotating machines, line and post insulators, etc. Such materials are usually made by introducing inorganic oxides (SiO2, TiO2, Al2O3, MgO) into polymeric matrices e.g. LÄS MER

7. 5. Surface harpooning Johan Strömquist

   Författare :Johan Strömquist; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; molecular affinity; charge transfer; surface harpooning; chemiluminescence; electron emission; dissociation;

   Sammanfattning : .... LÄS MER