Sökning: "electric breakdown"

Visar resultat 6 - 10 av 60 avhandlingar innehållade orden electric breakdown.

1. 6. Multipactor in low pressure gas and in nonuniform rf field structures

   Författare :Richard Udiljak; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; detection methods; iris; low pressure gas; coax; nonuniform fields; Multipactor; microwave discharge; breakdown; discharge;

   Sammanfattning : Resonant electron multiplication in vacuum, multipactor, is analysed for several geometries where the RF electric field is nonuniform. In particular, it is shown that the multipactor behaviour in a coaxial line is both qualitatively and quantitatively different from that observed with the conventionally used simple parallel-plate model. LÄS MER

3. 7. Numerical Simulations of Long Spark and Lightning Attachment

   Författare :Liliana Arevalo; Vernon Cooray; Dan Windmar; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; breakdown; discharge; leader channel; lightning attachment; negative discharge; positive discharge; streamer; Electrical engineering; Elektroteknik; Engineering Science with specialization in Atmospheric Discharges; Teknisk fysik med inriktning mot atmosfäriska urladdningar;

   Sammanfattning : The research work presented here is concerned with numerical simulations of two different electrical phenomena: Long gap electrical discharges under switching impulses and the lightning attachment process associated with positive upward leaders. The development of positive upward leaders and the progression of discharges in long gaps are attributable to two intertwined physical phenomena, namely, the leader channel and the streamer zone. LÄS MER

4. 8. Theoretical and Experimental Studies of the Formation of Ionized Gases in Spark Ignition Engines

   Författare :Raymond Reinmann; Förbränningsfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Thermal Ionization; Calorimetry; Interferometry; Spark Ignition Engine; Current and Voltage Measurements; Engine Control.; fluid dynamics; Gases; plasmas; Gaser; plasma; fluiddynamik; Breakdown; Arc; Glow; Flame Ionization; Chemi-Ionization; Spark; Townsend; Fysicumarkivet A:1998:Reinmann;

   Sammanfattning : The processes that govern the formation, existence and consumption of ions in gases have been studied both experimentally and theoretically. The aim of the work is targeted at increasing the understanding of these phenomena in the working gases inside an engine. LÄS MER

5. 9. Business Value Assessment of IT Investments : An Evaluation Method Applied to the Electric Power

   Författare :Magnus Gammelgård; Tosten Cegrell; Robert Winter; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; IT-investments; IT-investment evaluation; Business value assessments; Enterprise architecture; Technical evaluation of IT systems; Electric power industry; Industrial organisation; administration and economics; Industriell organisation; administration och ekonomi;

   Sammanfattning : s the dependence of IS/IT has grown in modern organizations, IT investments have soared in the last couple of decades. Large amounts of money are spent with the hope that the investments will generate value for the business organizations using the systems. LÄS MER

7. 10. Topographical Impact on Space Charge Injection, Accumulation and Breakdown in Polymeric HVDC Cable Interfaces

   Författare :Espen Doedens; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; interfaces; XLPE; roughness; cable peelings; polymer surfaces; space charge; field enhancement factor; PEA; DC breakdown; extruded cable; roughness enhanced charge injection; HVDC; charge injection;

   Sammanfattning : Extruded HVDC cable systems feature a variety of interface types, for which physio-chemical properties will depend on the type of application. Such applications can be joints, terminations or the cable itself, all introducing different material combinations and manufacturing methods. LÄS MER