South Africa produces alternative fuels from a number of different sources. The properties of a fuel are known to affect the nature of combustion in compression-ignition engines significantly, and have occasionally resulted in engine failures. Combustion analyses have been conducted on a wide range of fuels and combustion has been thoroughly quantified. However, the role played by the different combustion variables in failures was not known. The result was that it was not possible to predict the implications of variations in the nature of combustion. There was thus a need to investigate the relative role of combustion variables in the failure of engines. The mechanisms of combustion and engine failure were studied. All the variables required to determine combustion and engine durability were measured simultaneously. This research required the development of a complete engine research facility as well as specialized transducers. Fast response surface thermocouples were designed and constructed in order to monitor transient surface temperatures. Heat transfer rates were then calculated with the aid of Fourier analysis. Dynamic stresses were monitored by strain-gauges applied to the engine. A special high speed data acquisition system was developed. An existing heat release model was modified and used to calculate combustion rates. A comprehensive finite element model was developed to calculate piston temperatures and stresses. The role of each combustion variable in stress and durability was investigated by statistical analysis. The results successfully identified the causes of combustion related engine failures. The primary cause of engine failure was found to be thermal loading. The principal cause of any variation in thermal loading and thus engine durability was maximum cylinder pressure. The life of the engine was proved to be determined almost entirely by peak cylinder pressure. The role of the rate of pressure rise was proved to be insignificant. All the implications of variations in the nature of combustion can now be determined accurately. It will thus be possible to optimise engine modifications and fuel properties before validation by durability testing. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1989.

The South African Revenue Services fulfils a number of roles in the reform process of South African Society through its collection of revenue to fund Government programmes, the facilitation of trade and economic security and contributing to an economy that supports growth and development. As the key revenue collector of government, SARS is mandated to collect revenue from all taxes. These tax types include Income Tax, VAT, PAYE, and Skills development, Levy, Customs Duty and Excise Tax. One of the taxes administered by the SARS on behalf of the Ministry Of Finance is Excise Duty. The Customs and Excise Act 91 of 1964 defines Excise duty as any duty leviable on certain locally manufactured goods. The tax on these goods is commonly referred to as sin taxes by the Ministry of Finance as these goods are seen as luxury goods. Products on which Excise Duty in levied include alcohol, fuel, beer, cigarette, tobacco, spirits and wine. Prior to 2 April 2003 the system used by the Oil industry to account for the sales of fuel was a sales based system. This effectively meant that excise duty could be deferred for a period of up to two years. This manner of taxation allowed the fuel industry to only pay tax once there had been a sale of the fuel. It therefore reduced the tax liability at the time of manufacture. The Duty at Source initiative of the SARS was aimed at ensuring that all excise duties be collected at the time of manufacture rather than the time of sale. Duty at source for the fuel industry was implemented on 2 April 03. Duty at source requires that the duty is paid at source i.e. at the time of manufacture of fuel in the refineries. The purpose of the new system was to facilitate the easier collection of revenue and to introduce greater efficiency both for the South African Revenue Services as well as the external role players. The implementation of this new system of assessing duty created a series of administrative and compliance burdens for both parties i.e. for SARS and taxpayers. The implementation was further not supported by a strategic framework. Due to the lack of the strategic perspective, this study undertakes to identify, suggest and evaluate strategies to manage the cost of compliance as a result of the duty at source implementation. To support the suggested strategies an operational framework will also be developed to facilitate successful implementation. / Thesis (MBA)-University of KwaZulu-Natal, 2005.

No description available.

The manufacturing process for solventless extruded double base propellants involves a number of rolling and reworking stages. Throughout these processes a decrease in weight average molecular weight was observed, this was attributed to denitration. Differential scanning calorimetery data indicated that the reworking stages of extruded double base propellant manufacture were crucial to the homogenisation of the propellant mixture. To determine the homogeneity of the final extruded product, a sample was analysed across its diameter. No variations in stabiliser concentration, molecular weight, or Vickers hardness were detected. An accelerated thermal ageing trial simulating up to 8 years of ageing at 25°C was carried out to evaluate the storage characteristics. Reductions in stabiliser concentration, number average molecular weight, weight average molecular weight and polydispersity compared with un-aged samples were observed. The glass transition temperature measured using differential scanning calorimetery decreased by ~3°C. The decrease was attributed to the initial denitration reducing the energy of bond rotation and shortening the polymer chains, both factors reducing the energy required for movement. Modulus values determined from dynamic mechanical analysis temperature scanning experiments, did not detect significant variation between un-aged and aged samples. Though it was considered that variations would be likely if a more extensive ageing program was completed. In order to evaluate propellant behaviour at very high and low frequencies, time temperature superposition (TTS) and creep testing were carried out. The TTS technique superpositioned data well, allowing future investigation of high frequency propellant properties. Creep testing was considered to be an appropriate approach, though the equipment available was not optimised for such testing. This thesis is concerned with understanding how propellants are manufactured from nitrocellulose, nitroglycerine and other constituents. It is also about how the propellants decompose during long periods of time in storage, and how these changes can be measured using thermal and mechanical methods. It is about how the physical, chemical and thermal properties of the propellant composition change throughout the manufacture. This is relevant as it could be used to develop more efficient manufacturing processes, allow operators to adjust processes to tailor product properties or be used to re-design manufacturing to compensate for a different starting material. The thesis also considers how and why the properties of the product change over the course of years of storage. A specific focus on whether changes in mechanical and thermal properties occur, and if so how they can be detected.

No description available.

Thesis (Ph. D.)--Texas A&M University, 2007. / "Major Subject: Agricultural Economics" Title from author supplied metadata (automated record created on Nov. 2, 2007.) Vita. Abstract. Includes bibliographical references.

Thesis (Ph. D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on November 26, 2007 Vita. Includes bibliographical references.

Thesis (M.S.)--University of Nevada, Reno, 2007. / "December, 2007." Includes bibliographical references (leaves 25-28). Online version available on the World Wide Web.

Thesis (M.U.R.P. 1979) from the Department of Architecture, University of Adelaide. / Includes bibliographical references (p. 165-188).

Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 69-73). Also available on the World Wide Web.