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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Pre-stroke radiation from thunderclouds

Zonge, Kenneth Lee, 1936- January 1965 (has links)
No description available.
32

Measurement of the charge transferred during the lightning discharge

Meese, Allen Douglas, 1937- January 1961 (has links)
No description available.
33

The determination of the excitation temperature of lightning

Prueitt, Melvin Lewis, 1932- January 1962 (has links)
No description available.
34

Identification and classification of lines in slitless spectra of lightning

Orville, Richard Edmonds, 1936- January 1963 (has links)
No description available.
35

Lightning activity of radar-observed storms.

Cominos, Theodore January 1972 (has links)
No description available.
36

Amplitude distribution of sferics signals from thunderstorms

Smith, Gary Kenneth January 1977 (has links)
No description available.
37

Location of lightning within thunderstorms.

Percy, James Ernest January 1973 (has links)
No description available.
38

A statistical lightning model.

Van Zyl, Marlie. 29 November 2013 (has links)
The detailed spatial and temporal influence of lightning on precipitation losses from the Earth's radiation belts is not yet well known. The precipitation is mainly due to the pitch angle scattering of electrons by lightning induced whistler mode waves. The World Wide Lightning Location Network (WWLLN) gives continuous real-time global lightning coverage with excellent time resolution. The detection effciency of WWLLN is unfortunately relatively low. This led to the normalisation of WWLLN with reference to Lightning Imaging Sensor (LIS)/Optical Transient Detector (OTD) data. LIS/OTD has very good detection effiency and spatial resolution. However, whereas WWLLN records strokes, LIS/OTD record flashes. Therefore the flash multiplicity had to be taken into account. The normalised WWLLN flash densities were compared to those of the South African Weather Service (SAWS) data, National Lightning Detection Network (NLDN) and the European LINET network. Then the average power per lightning flash was calculated to determine the energy flux incident on the ionosphere. Finally the WWLLN data was transformed to geomagnetic (MAG) coordinates using the Altitude Adapted Corrected Geomagnetic (AACGM) code. By applying absorption curves, the energy flux into the magnetosphere was estimated. These values were then compared to Trimpi produced Whistler-Induced Electron Precipitation (WEP) rates. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2012.
39

Multifractal analysis and modelling of lightning stroke maps for power systems

Faghfouri, Aram 27 September 2011 (has links)
Since electric power is one the most important necessities for today’s life and industry, its service reliability must be maintained in an extremely high level. Thunderstorms often reduce this quality of service. Since cloud-to-ground lightning strokes are among the most frequent yet least understood causes of service interruption, predicting the geographical and temporal distribution of the lightning strokes can help power system planners and designers improve the protection of new and existing transmission lines. Such a prediction needs a model that is based on physical properties of the phenomenon and acquired data. This approach requires several stages including modelling, simulation, and characterization. Characterization provides metrics for comparison between the physical and simulated data. The distributions of the lightning stroke densities (aka lightning stroke maps (LSMs)) have patterns that are highly nonlinear, nonstationary, and stochastic. Ordinary analyzes and metrics are insufficient to characterize such patterns. Multiscale analysis of these patterns indicates their self-affinity over multiple scales, which is an indication of their multifractality. Consequently, multifractal analysis methods such as the Rényi fractal dimension spectrum are appropriate candidates for characterization of these density maps. This work uses the lightning stroke data collected by Canadian lightning detection network for Manitoba from 1998 to 2006, employs a multifractal analysis of the lightning stroke maps, and investigates the consistency of such a characterization over time. The results indicate that the LSMs of Manitoba have multifractal distributions, both locally and globally. The results also indicate a convergence in statistical distribution for the LSMs and strong sensitivity of the Rényi spectra to the data variations. For modelling such data, multifractal approaches such as diffusion limited aggregation, percolation, or cellular automata are appropriate candidates. This work provides diffusion limited aggregate modelling and simulation for the maps and compares the physical and simulated lightning stroke maps through Rényi spectra, where the results indicate a high similarity, both visually and analytically. Since lightning strokes are global phenomena, the same methods and techniques can be used for LSMs anywhere in the world. In addition, the utilized methods and approaches for analysis and modelling can be used for similarly complicated phenomena.
40

Multifractal analysis and modelling of lightning stroke maps for power systems

Faghfouri, Aram 27 September 2011 (has links)
Since electric power is one the most important necessities for today’s life and industry, its service reliability must be maintained in an extremely high level. Thunderstorms often reduce this quality of service. Since cloud-to-ground lightning strokes are among the most frequent yet least understood causes of service interruption, predicting the geographical and temporal distribution of the lightning strokes can help power system planners and designers improve the protection of new and existing transmission lines. Such a prediction needs a model that is based on physical properties of the phenomenon and acquired data. This approach requires several stages including modelling, simulation, and characterization. Characterization provides metrics for comparison between the physical and simulated data. The distributions of the lightning stroke densities (aka lightning stroke maps (LSMs)) have patterns that are highly nonlinear, nonstationary, and stochastic. Ordinary analyzes and metrics are insufficient to characterize such patterns. Multiscale analysis of these patterns indicates their self-affinity over multiple scales, which is an indication of their multifractality. Consequently, multifractal analysis methods such as the Rényi fractal dimension spectrum are appropriate candidates for characterization of these density maps. This work uses the lightning stroke data collected by Canadian lightning detection network for Manitoba from 1998 to 2006, employs a multifractal analysis of the lightning stroke maps, and investigates the consistency of such a characterization over time. The results indicate that the LSMs of Manitoba have multifractal distributions, both locally and globally. The results also indicate a convergence in statistical distribution for the LSMs and strong sensitivity of the Rényi spectra to the data variations. For modelling such data, multifractal approaches such as diffusion limited aggregation, percolation, or cellular automata are appropriate candidates. This work provides diffusion limited aggregate modelling and simulation for the maps and compares the physical and simulated lightning stroke maps through Rényi spectra, where the results indicate a high similarity, both visually and analytically. Since lightning strokes are global phenomena, the same methods and techniques can be used for LSMs anywhere in the world. In addition, the utilized methods and approaches for analysis and modelling can be used for similarly complicated phenomena.

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