ABSTRACT The efficiency of mixing processes in impeller agitated tanks depends highly on the hydrodynamics. Computational fluids dynamics (CFD) provides a method of predicting the complex tlow structures in stirred tanks. As with any approximate numerical method, CFD methods are subject to errors due to assumptions in the underlying mathematical models, as well as errors due to the numerical solution procedures. The aim of this thesis was to present a CFD method that accurately models the hy...
ABSTRACT Continuum and finite element formulations ofthe static and dynamic initial-boundaryvalue evolution (elastoplastic) problems are considered in terms of both the classical and internal variable frameworks. The latter framework is employed to develop algorithms in the form of convex mathematical programming and Newton-Raphson schemes. This latter scheme is shown to be linked to the former in the sense that it expresses the conditions under which the convex non-linear function can be m...
ABSTRACT Several theories of creep and creep rupture are reviewed. Specific attention is devoted to the brittle damage theory proposed by Kachanov. Creep, damage and life predictions for rectangular or circular cross section beams under bending and tensile loads are presented. Comparison with data for a Ni Superalloy showed life predictions could be 30X in excess of experimental values. This beam model also revealed that it is imperative that no bending moments be inadvertently applied during...
ABSTRACT Coal is one of the most importa~t energy resources in South Africa. It covers 80% of the country's energy needs and provides valuable foreign exchange and employment. The purpose of this thesis is to provide an analytical framework for the examination of the demand for coal for the generation of electricity where more than 50% of the coal produced in the country is consumed. More specifically, the aim of the thesis is to identify the factors influencing the demand for steam-coal, dis...
ABSTRACT Energy benchmarking and carbon footprint reduction opportunities in Portland cement manufacturing processes in Nigeria are presented. Life Cycle Assessment (LCA) is used to estimate the environmental impact of three cement manufacturing processes in Nigeria. The energy consumption of the cement manufacturing processes are evaluated using energy Benchmarking and Energy Savings Tool for cement (BEST-Cement). BEST-Cement evaluates and compares the energy consumption of the cement manuf...
Abstract The Design of an Efficient Solid Waste Management and Disposal Scheduling System in a metropolis is hereby presented. The design employed ten landfill sites in contrast to the existing one landfill site in the metropolis. The metropolis was divided into ten zones and a Hungarian mathematical model was used to get the optimal assignment of the proposed landfill sites to the zones. This model was applied to the field data obtained from the road net-work of Enugu metropolis and Enugu S...
ABSTRACT This study is about the production and characterization of epoxy-rice husk ash composite. Composites were produced at 10%,20%,30%,40% and 50% volume fraction of Rice Husk Ash(RHA) fillers and the epoxy was cast neat at 0%RHA which served as the control .The microstructure of the composites were studied with Scanning Electron Microscopy(SEM) and Energy Dispersive X-ray Spectroscopy(EDX).Mechanical properties of the composites such as tensile properties(tensile stress, tensile strain,...
ABSTRACT Energy benchmarking and carbon footprint reduction opportunities in Portland cement manufacturing processes in Nigeria are presented. Life Cycle Assessment (LCA) is used to estimate the environmental impact of three cement manufacturing processes in Nigeria. The energy consumption of the cement manufacturing processes are evaluated using energy Benchmarking and Energy Savings Tool for cement (BEST-Cement). BEST-Cement evaluates and compares the energy consumption of the cement manuf...
ABSTRACT In this work, the state of stress between adhesively bonded single lap-joints was determined. The state of stress between adhesively bonded single lap-joints was determined by using a linear elastic analysis and experimental testing. In the analysis part of this work, the shear and normal stresses in an adhesively bonded single lap –joints were predicted by subjecting the joint to tension; shear force, and bending moments. Differential equations were used to model the problem and ...
ABSTRACT A working inventory model is developed to incorporate the partial back ordering inventory with references to the back ordering inventory model by Jonah and Chukwu. The re-order point models of maximum expected cost and service level approach were also established. Data, covering the demand, set-up cost, and the Holding cost were obtained from the Champion Breweries Plc, other related data were estimated. These enabled the application of the models to obtain, the review period, ...
Abstract In general, the electrowinning process consumes substantial electrical energy. Considering the ever-increasing unit cost of electrical power there is a need to improve current efficiency so that electrical energy is utilised efficiently. In light of the research/knowledge gap identified, this research aims to design a continuous quality improvement framework for improving electrowinning current efficiency. The objectives of this research are as follow: (i) To explore factors that inf...
ABSTRACT Energy benchmarking and carbon footprint reduction opportunities in Portland cement manufacturing processes in Nigeria are presented. Life Cycle Assessment (LCA) is used to estimate the environmental impact of three cement manufacturing processes in Nigeria. The energy consumption of the cement manufacturing processes are evaluated using energy Benchmarking and Energy Savings Tool for cement (BEST-Cement). BEST-Cement evaluates and compares the energy consumption of the cement manufa...
ABSTRACT The use of quality control techniques such as Statistical Process Control (SPC) has become essential for any business to thrive in the modern industry. Statistical quality control is one of the reasons why the Japanese had a significant advantage over their competitors. However, many organizations are still not yet applying this powerful quality control technique (Ben & Jiju, 2000; Helm, 2018). In addition to that, although substantial research has been done to improve electrowinnin...
Abstract: Each hydropower plant is usually designed for specific amount of discharge and gross head. This paper presents the methods used to measure the discharge and gross head variables with additional of assessment tools. Discharge measurement methods covered include bucket, float, velocity-area, dilution, hydraulic structure and advanced discharge measurement while gross head measurement methods covered include topographic and DEM maps, hose level with pressure gauge, sight level, spirit ...
Abstract. The hydropower resources have become an attractive means of generating electricity to the off-grid network, especially in rural areas. This article assesses the small, mini and large hydropower resources and identified to reach 5.3GW for electricity generation in Tanzania. The technology development discussed comprises of hydro turbine manufacturers, classification and turbine selection. The barriers presented include the presence of sediment in the hydropower reservoirs, financial ...