Thesis (M.S.)--University of Michigan, 1977.

Thesis (M.S.)--University of Michigan, 1976.

Thesis (Ph. D.)--Lehigh University, 2000. / Includes bibliographical references and vita.

Thesis (M.S.)--University of Michigan, 1981.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 50-54). Also available via the Internet.

Thesis--University of Missouri, School of Mines and Metallurgy, 1916. / The entire thesis text is included in file. Typescript. Illustrated by author. Title from title screen of thesis/dissertation PDF file (viewed April 21, 2009)

M.Ing. / In the highly competitive environment in which all companies have to operate, it is becoming more and more important to optimise the amount of time a piece of equipment is down for scheduled repairs and the scheduling of these repairs. In this dissertation the equipment that is considered are the seventeen Babcock Borsig designed boilers situated on the Sasol Secunda site. A schematic drawing of these boilers is shown in figure 1. This drawing does not include the Electrostatic Precipitator that is located at the outlet of the boiler. The main function of the seventeen boilers on the Secunda site is to supply process steam to the rest of the factory. With each of the plants that are supplied with process steam having its own needs at any point in time, ensuring that enough steam is available in the system becomes an extremely important issue. The reason for this is that the plants that are supplied with process steam form a train and if one of the plants can not produce to full capacity, the down stream plants are also affected. The secondary function of the boilers is to supply steam to ten turbines for the generation of electricity. This means that any steam that the factory is not using is used for the generation of electricity. The ten generators can not supply the full need of the factory and the rest is drawn in from the national electricity supplier. It is thus best to generate as much electricity as possible. With the price of electricity varying during the year, winter being more expensive, the time when a boiler is off becomes critical. To ensure that the necessary process steam is available the long term plan of the factory is used to calculate the year budget for steam required by the factory. But as with everything plans do change and a short term plan is used to ensure that enough process steam is available for the factory.

Submitted for t he MASTERS OF SCIENCE Chemistry in the Department of Chemistry UNIVERSITY of the Witwatersrand December 1995

The design of a point focus, distributed receiver solar power system is presented. It is shown that a two axis concentrator, with a two axis solar tracker and drive, has significant advantages over other possible optical systems. It is further shown that each concentrator should have its own optical receiver attached. A new dish and mount design is presented. This design provides a much stronger, lower cost dish. It further provides an easy way to attach a cheap drive system. The new mount is a gimbal, or cradle, in which the dish is mounted. The cradle provides a polar axis mount for the dish. The dish and cradle are very strong and will survive high winds in any orientation. Several other significant improvements to other parts of the solar energy collection system are presented. These include an improvement to the receiver cavity design, a thermal shield and secondary reflector to be added to the receiver, an improved steam output system for the receiver, a plumbing system that eliminates the need for flexible couplings in the water lines, and a water distribution system that eliminates nearly half of the thermal insulation needed on the pipes going through the collector array. Two economic optimizations are presented. The first analyses the return on investment for various dish spacings. The second analyses the cost per unit area of the concentrator dish and mount. It is found that the optimum dish diameter is ten meters and the optimum packing density in a conventional array is about 13%. / Graduation date: 1995

Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 84-85). Also available on the World Wide Web.