Engineering

Publication Search Results

Sort
Results per page
Now showing 1 - 10 of 430
  • Electrolyte optimization and electrode material evaluation for the vanadium redox battery
    (1989) Kazacos, Michael
    Thesis
    In this project the preparation of the electrolyte for the all vanadium redox flow battery was investigated using both chemical and electrolytic reduction of ^O,- powder. Oxalic acid and SO^ reduction were found to be unsuitable as only the V(IV) state could be produced directly. With suspended powder hydrolysis, however, vanadium sulphate of any oxidation state, in this case 50% V(IV) plus 50% V(III) in sulphuric acid can readily be prepared from V^O^ powder, thus allowing a significant reduction in the cost of the vanadium battery electrolyte. Results from conductivity and electrolyte stability tests at elevated temperature have led to modification of the electrolyte composition for the vanadium redox cell, from the 2 M V plus 2 M H^SO^, originally employed, to the use of 3 M H^SO^, much higher energy efficiencies and greater electrolyte stability was demonstrated with the 3 M H^SO^ supporting electrolyte. Spectroscopy and electrolyte conductivity have been demonstrated as suitable techniques for state-of-charge monitoring. A number of electrode materials were also evaluated and a Toray graphite bonded to a carbon plastic electrode was selected for further prototype development. Energy efficiencies of between 83 and 86% were obtained for a current density of 30 mA/cm for a temperature range 5 to 45'C, and between 0 and 100% state-of-charge. A wide range of construction materials was tested for long term stability in the vanadium redox electrolyte.
  • Harmoniac - a digital signal processor
    (1981) Connor, Philip Michael
    Thesis
  • Oil pressure effects in H.V. underground cables
    (1980) Walker, Graham P.
    Thesis
    The basis of the design of the oil system of a H.V. oil filled cable circuit is considered in particular the choice of oil feed locations along the cable route. Methods are established for determining the oil pressure tank requirements and the oil pressure response on application of step or pulse loads for typical oil sections of a single core H.V. oil filled cable circuit. These methods are applied to an existing 132 KV installation and minimum oil pressure tankage requirements and the maximum and minimum transient oil pressures considering various loading conditions determined. To establish the minimum transient oil pressure the oil pressures occurring on switching off various continuous loads are compared to that occurring on switching off load shortly after having switched on. Recommendations are made for similar circuits based on the loading condition giving the minimum transient oil pressure. Possible ways of verifying the theoretical methods and en electrical analogue of the oil system are considered.
  • A basis for optimal irrigation systems design, operation and evaluation
    (1984) Chalomba, Christopher Mukundanji
    Thesis
  • Digital full duplex on two wire subscriber line
    (1981) Hardadi, Moehamad
    Thesis