Sökning: "Initial breakdown"

Visar resultat 1 - 5 av 50 avhandlingar innehållade orden Initial breakdown.

1. 1. Microwave Breakdown in Inhomogeneous Fields

   Författare :Joel Rasch; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; corona; inhomogeneous fields; Microwave breakdown; multipactor;

   Sammanfattning : Microwave breakdown continues to be a risk in many applications involving the transmission and reception of microwave frequency signals. Satellite communication is especially interesting from the research point of view because of the extreme costs, and limited testing possibilities. LÄS MER

3. 2. 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

4. 3. 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. 4. Temporal and Wavelet Characteristics of Initial Breakdown and Narrow Bipolar Pulses of Lightning Flashes

   Författare :Mona Riza Mohd Esa; Vernon Cooray; Mahbubur Rahman; Farhad Rachidi; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Initial breakdown; Lightning flash; Narrow bipolar pulse; Temporal-Wavelet characterization; Engineering Science with specialization in Atmospheric Discharges; Teknisk fysik med inriktning mot atmosfäriska urladdningar;

   Sammanfattning : Temporal and wavelet characteristics of initial breakdown pulses are meticulously studied especially during the earliest moment of lightning events. Any possible features during the earliest moment that may exist which lead to either negative cloud-to-ground (CG), positive cloud-to-ground, cloud or isolated breakdown flashes in Sweden are investigated. LÄS MER

7. 5. Signal transduction in the brain : modulation of receptor-mediated inositol phospholipid breakdown by potassium and fluoride ions

   Författare :Gunnar Tiger; Umeå universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Inositol phospholipid breakdown; muscarinic receptors; potassium; fluoride; rat brain; pig brain;

   Sammanfattning : Neurotransmitter receptor types mediating the generation of intracellular signals are of two types; ligand-gated ion channels and G protein coupled receptors. The effector enzyme phosphoinositide-specific phospholipase C (PLC) is modulated by stimulation of G protein coupled receptors, leading to an increased breakdown of inositol phospholipids ("Ptdlns breakdown"). LÄS MER