Sökning: "Teknisk fysik med inriktning mot atmosfäriska urladdningar"
Visar resultat 1 - 5 av 9 avhandlingar innehållade orden Teknisk fysik med inriktning mot atmosfäriska urladdningar.
1. Broadband and HF Radiation from Cloud Flashes and Narrow Bipolar Pulses
Sammanfattning : Remote measurement of electric field generated by lightning has played a major role in understanding the lightning phenomenon. Even though other measurements such as photographic and channel base current have contributed to this research field, due to practical reasons remote measurements of electric field is considered as the most useful tool in lightning research. LÄS MER
2. Positive streamer discharges in air and along insulating surfaces: experiment and simulation
Sammanfattning : The power quality of modern society relies on the electrical properties of the dielectric insulators used in the power industry. Much research work has been conducted with an aim to understand and predict the insulating behaviour of such materials under different kinds of atmospheric conditions, but still there are many unsolved problems. LÄS MER
3. Interaction of Lightning Flashes with Wireless Communication Networks : Special Attention to Narrow Bipolar Pulses
Sammanfattning : In this thesis, the features of electric field signatures of narrow bipolar pulses (NBPs) generated by cloud flashes are investigated and their effects on wireless communication systems are studied. A handful amount of NBPs (14.5%) have been observed to occur as part of cloud-to-ground flashes in South Malaysia. LÄS MER
4. Numerical Simulations of Long Spark and Lightning Attachment
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
5. Characterizations of ground flashes from tropic to northern region
Sammanfattning : This thesis portrays new information concerning the cloud-to-ground (CG) lightning flashes or ground flashes produced by thunderclouds. It emphasizes the importance of characterizing lightning studies as the relationship between lightning mechanisms, and of incorporating the influence of geographical location, latitude and storm type. LÄS MER