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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.
1

The Creation of Long Distance Directional Plasma Discharges via the Exploding Wire Technique

Smith, David William Robin January 2008 (has links)
This thesis describes the work completed to create long distance directional discharge using the exploding wire technique. A historical literature review gives the previous works completed on exploding wires dating back to 1780. The review also gives the current understanding of the exploding wire phenomena. The design and construction of a test set to create long distance exploding wires is outlined. A capacitor bank, high voltage switch, charging circuit, hand earths design and construction methods are given. The measurement of the impulse and charging voltage and current is explored and solutions found. Design and construction of a Rogowski Coil and associated circuitry is outlined. Development of software made for reconstruction of Rogowski signals is outlined. Results of testing of different wire explosions is given. It is found that if the charge voltage of the capacitors is to high the wire explodes to fast to remove all charge from the capacitors. If the charge is too low the wire may not have enough energy to explode. Conditions for maximum energy discharged by a plasma shrouded exploding wire are found for varying wire diameters and lengths up to 10m.
2

Long Distance Exploding Wires

Sinton, Rowan Peter William January 2011 (has links)
Electrical arcs are usually created with the breakdown of air, requiring an average electric field (AEF) of at least 100 kV/m in long spark gaps. This thesis explores a novel method of creating long electrical arcs using exploding wires (EWs). Arcs up to 60 m long have been produced with AEFs of just 4.5 kV/m. Extensive observations of the EW process are presented, which demonstrate that the arcs, which are a type of ‘restrike', form via the seldom-reported ‘plasma bead' restrike mechanism. Beads of plasma appear to form at sites of wire fragmentation, and can expand and coalesce into a continuous plasma column. There are strict conditions under which the plasma beads, and hence restrike channels, are produced. A restrike prediction model has been developed to provide a reliable method of producing restrike. The model was derived from the improved understanding of the restrike mechanism, and uses the wire's length and the energy supply voltage and characteristics as inputs. Capability diagrams are then constructed, which allow researchers to easily design experiments that will produce restrike. Extensive descriptions are provided of the experimental environments that were designed and constructed to facilitate long distance EW experiments. Experiments have been performed inside a high voltage laboratory, in the laboratory's outdoor compound, off the laboratory's earth grid and completely off-site. The off-site location allowed vertical experiments, suspended by a weather balloon, to be performed. This led to a theory on artificially triggered lightning, which is one of many exciting future applications that are suggested. It is also predicted that other research groups will be able to create arcs of several hundred metres long.
3

The creation of long distance directional plasma discharges via the exploding wire technique : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Engineering in Electrical and Computer Engineering at the University of Canterbury, Christchurch, New Zealand /

Smith, David January 2008 (has links)
Thesis (M.E.)--University of Canterbury, 2008. / Typescript (photocopy). Includes bibliographical references (p. [153]-155). Also available via the World Wide Web.
4

Processing Microstructure Evolution and Properties of Nanoscale Aluminum Alloys

Han, Jixiong 26 September 2005 (has links)
No description available.

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