Mechanical & Marine Engineering

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Now showing 1 - 3 of 3
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    (2020-04) Moongo, Thomas E.
    Continuous quality improvement by applying statistical process control has been long recognized in the processing industry. Effectively monitoring and controlling of process variability can result in sustained process stability and maximized process efficiencies. The electrowinning process is an energy-intensive process, and the cost of electrical energy is ever increasing. The effectiveness of utilizing electrical energy in the electrowinning process is best measured by current efficiency. Although substantial research has been done to improve current efficiency, no evidence on improving current efficiency from a quality perspective or by applying statistical process control has been found in the reviewed literature. This identified knowledge/research gap needs to be filled. This research project intends to contribute to the existing knowledge by filling the identified knowledge/research gap. The research aims to design a continuous quality improvement framework for improving electrowinning current efficiency. The objectives of the research are as follow: (i) to explore factors that influence current efficiency, (ii) to evaluate the factor that has the most significant effect on current efficiency, by applying statistical process control, and (iii) to develop a continuous quality improvement framework for improving current efficiency, by applying statistical process control. A sequential mixed research methodology was applied in this research. In this case, a qualitative research approach was followed by a quantitative research approach. Questionnaires were utilized to establish factors influencing current efficiency and best practices for improving current efficiency. The quantitative research approach was accomplished by collecting and analyzing electrolyte samples and instrument data. This is in addition to gathering historical data from an instrument database and analytical laboratory database. The established research strategy includes exploring current efficiency factors, analyzing historical data, establishing current efficiency improvement best practice and finally designing a continuous quality improvement framework for improving electrowinning current efficiency.
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    Development of a sun tracking system for a small solar concentrator.
    (NUST, 2010) Mutaleni, C.; Bishi, Isabel; Zulu, Andrew; Swaminathan, Rajaram
    An automatic sun tracking system was extended to a parabolic dish solar concentrator which can be used to cook or heat water. Parabolic dish solar concentrator has been in use couple of decades ago but has been tracking the sun manually. The automatic sun tracking system was incorporated on the parabolic dish with success and it works satisfactory. Every time the dish was left in the sun, it was found facing the sun as expected. These systems has been researched and developed before and applied on large scale applications like solar power generation plants and small electricity generation projects for remote areas which are not connected to national power grids.
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    Design and development of solar concentrator for thermal applications.
    (NUST, 2010) Bishi, Isabel; Zulu, Andrew; Swaminathan, Rajaram
    Parabolic mirror surfaces are found wherever energy needs to be focused effectively and accurately. They are found built into car headlights, spotlights as well as astronomical telescopes. This research concerns the study of transformation of solar energy into thermal energy and focusing this energy at a point to heat water. In this document the parabola was explored to design a simple, cheap and effective solar water heater. Local communities in Namibia can produce similar water heaters using available materials and the fuel; sunlight is abundant throughout the year in most areas. The main part of the heater, the collector can have any shiny material as long as it refracts the sun’s rays. In this project a parabolic solar concentrator was designed and constructed to heat water at the focal point, which is then stored in a tank for use.