Wilson R. Nyemba

Wilson R. Nyemba
University of Johannesburg | uj · Department of Mechanical Engineering Science

Doctor of Engineering (Mechanical)

About

81
Publications
43,052
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178
Citations
Citations since 2017
60 Research Items
174 Citations
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201720182019202020212022202301020304050

Publications

Publications (81)
Chapter
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Polyethylene terephthalate is majorly used for packaging of various products because of its resistance to chemical attack and environmental degradation, but the proper disposal of this non-biodegradable material has been a major challenge. Pyrolysis is the melting of plastic in the absence of oxygen. Currently pyrolysis of polyethylene terephthalat...
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Over the years, there has been growing calls for academia to work closely with industry and several models have been developed such as the Triple Helix framework. Generally, such models were premised on the basis of close collaboration of academia, governments and industry in such a way that academia provided the tuition and development of human re...
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The direct and dynamic relationship linking academia with industry has been the ability by academia to provide practical solutions and innovations to solve industry’s challenges. In recent years and in response to the rapid changes in technology, higher education institutions have invested in innovation hubs for incubating novel ideas as well as te...
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The ultimate expectation from any innovations that are nurtured through incubation and product development was to commercialise them for wealth creation, entrepreneurships and industrialisation. Several centres of excellence have been established in Southern Africa, either housed at or in collaboration with tertiary institutions, some of which have...
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Systems thinking has been an effective approach to managing organisations going through changes as synthesis allowed the observation of how different entities interacted and influenced how an overall system operated. The rapid changes in technology due to the fourth Industrial Revolution demanded regular and corresponding changes in skills to cope...
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Several studies carried out in Sub-Saharan Africa have pointed to the perennial and persistent shortage of skills, let alone the access to modern equipment and technology by engineering academics, resulting in the compromised quality of engineering graduates and mismatch of skills required by industry and those that tertiary institutions produced....
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Industrial operations have evolved through massive transformations and in recent years, the rate of change has been so rapid, equally requiring rapid transformations in the engineering education system. This chapter focusses on the various industrial transformations, particularly the current Industry 4.0, its impact and implications on the educatio...
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While collaborations between polytechnics and industry existed and were well pronounced in the earlier revolutions where apprenticeship training was key to driving industry, the relationship between industry and universities was not well pronounced. The transformations in the engineering education sector, especially from the third to the fourth Ind...
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Unlike during the earlier industrial transformations, tertiary institutions have adopted a new pedagogy of problem-based learning (PBL) in which practical industry problems are used as case studies in lectures to quicken the students’ understanding of industrial operations. Industry-based learning (IBL) involves the professional placement of underg...
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The provision of solutions for industry in terms of modelling and simulations, ultimately leading to optimisation of manufacturing, mining or other engineering processes, is usually the preserve of production and process engineers. However, the shortage of such professionals often force companies to engage foreign expertise, which is usually quite...
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Collaborations among tertiary institutions for research and other related activities have never been more important, particularly in this era of dynamic and rapid changes in technology. Performance of institutions have also become topical as more ranking organisations have been created to assess the integrity and competitiveness of tertiary institu...
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Despite rapid and dynamic changes in technology and the disruptive but necessary innovations orchestrated by the fourth Industrial Revolution that required the production of goods and services in industry to be driven by technology and knowledge transfer from tertiary institutions, the gap between academia and industry remained wide. This has been...
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There are several underlying factors that are sometimes ignored while diagnosing companies with low capacity utilisation such as sustainability strategies for continuity and holistic approaches to engineering change management in this era of dynamism in technology. This chapter focusses on establishing the failures that contributed to low capacity...
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The research on bridging the gap between academia and industry in Southern Africa in collaboration with UK institutions was executed during the decade spanning from 2010 to 2020, a period in which many challenges such as the aftermath of the global financial crisis and the COVID-19 pandemic were witnessed. This was coupled with rapid changes in tec...
Book
This book is the result of years of research following a realization of the mismatch of engineering skills produced by universities and those that industry required, based on the situation in Sub-Saharan Africa, equally applicable to other regions in Africa and indeed worldwide. The book is meant to assist engineering academics and engineers in ind...
Article
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Wall plastering is a laborious and often time-consuming process for the construction industry. Mortar spraying is the rendering of mortar at high velocity to achieve compaction and placement at the same time. This research aimed at conceptualizing various options, leading to the development, design and fabrication of a semi-automated machine to red...
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Sub-Saharan Africa suffers from a persistent shortage of engineering skills required to drive industry in this dynamic era of rapid technological changes. This has been exacerbated by the mismatch of skills produced by universities and those required by industry, partly attributed to lack of access to modern equipment and technology by engineering...
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Southern Africa and indeed Zimbabwe, which is in the center of this region, is endowed with a plethora of natural resources including abundant exposure to solar radiation throughout the year. However, the potential to harness this resource remains untapped largely due to lack of capacity and technology. This research aimed at developing an intellig...
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This paper describes the design of a manually operated granite stone crushing machine. This machine is targeted for people who are currently in the stone crushing business and use manual methods like the hammer and anvil. Due to the expensive nature of available stone crushers in Zimbabwe small-scale crushing business people cannot afford these mac...
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Energy shortages and rapid increase in its demand are amongst the major problems facing the world today. In response to the rapid depletion of fossils fuels, other alternative energy sources have been explored. One of the methods of generating energy is converting plastics into usable fuel. Two major problems facing the world today prompting to pyr...
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A reliable and sustainable means of human transportation is vital for the world’s increasing pollution emissions and congestions on the motorways. The research aimed at and focused on developing an affordable electric drive train for cycles using the principle of Continuously Variable Transmission (CVT) to provide an interminable number of speed ra...
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The appropriate handling of materials in manufacturing is essential for the realization of reductions in direct and indirect costs. This research was carried out at a plastic manufacturing company in Zimbabwe where polymer pellets are used to produce plastic packaging. An in-depth work study was carried out at the plant followed by the feasibility,...
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The general decline in the retention of professionally qualified engineers in academia and industry vary from country to country and has been attributed to different reasons for industrialized and industrializing states. This paper focuses on the outcome from a Royal Academy of Engineering (RAEng) initiative in Sub-Saharan Africa, aimed at enrichin...
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The demand for electricity has escalated and cannot be fulfilled by conventional energy sources alone. There has been a rising demand to seek new renewable energy sources. Although solar and wind energy are the most cost effective renewable energy sources, they are unreliable due to the sporadic nature of their occurrence, if implemented as standal...
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Conventional refrigerators impact on the environment contributing to ozone depletion and global warming. Common refrigeration methods make use of Chlorofluorocarbons (CFCs), Hydro chlorofluorocarbons (HCFCs) and Hydrofluorocarbons (HFCs) which all have negative effects on the environment. Legislation in some countries has been enforced to ban the u...
Conference Paper
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Frequent breakdowns of the pebble crusher at a platinum processing company in Zimbabwe prompted the need to evaluate and optimize its operations which had evidently become the bottleneck for the processing plant. The research focused on analysis and optimization of the crushing mechanism by way of identifying the major causes of failure, which incl...
Conference Paper
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Power plant steam condensers use cooling water for condensation of exhaust steam from turbines. Depending on the concentration of cations in the cooling water, changes in temperature result in the precipitation of insoluble metal salts on the tube walls hence impeding heat transfer, leading to fouling, a threat on the heat transfer efficiency of th...
Conference Paper
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Fossil fuels have been the main source of energy for many years hence the depletion of resource. There is therefore a need for alternative cleaner energy sources of fuel to be explored. The use of these conventional fuels led to land degradation global warming and air pollution. A wood gasifier machine which produces combustible gas from solid fuel...
Chapter
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Documenting process flows in a manufacturing environment provides a guide to understanding how processes are interconnected and how materials are handled, thus forming the basis for modelling and optimization in order to simplify the otherwise complex systems particularly in multi-product manufacturing. Research was carried out at a furniture manuf...
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The various stages in the manufacture of furniture, from cutting through processing to polishing, produces a lot of sawdust of varying grades. The extraction and disposal of such waste in a developing country such as Zimbabwe, with no established or sustainable ways to handle waste, is a growing concern, often posing environmental challenges. Resea...
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Zimbabwe is endowed with a plethora of natural resources sufficient to provide raw materials and inputs to its engineering, mining and processing companies. Despite having inherited functional industries at independence, over the last 15 -20 years, the country has been grappling with recession, low capacity utilization, liquidation of companies and...
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Excess waste is common in foundry die-casting processes due to a number of factors. These include sizes of runners and gates, heat and pressure that may result in expanded sizes of runners and oversized products that require more time for fettling after solidifying and removal from moulds. The gating system, runners and handling of the molten metal...
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Southern Africa has been grappling with power shortages over the last decade due to reduced generating capacities from the region’s few hydroelectric power plants and depleted coal reserves for thermal power generation. This forced many companies to operate below capacity, although potential and resources abound. Research was carried out at one of...
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Appropriate arrangement of machinery in a manufacturing environment can have a positive impact on the productivity of a company. A detailed work study carried out at a furniture manufacturing company revealed that parts travelled long distances before the final product is produced owing to the positions of machinery and crisscrossing process flows....
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Lack of proper inventory control usually leads to high stock-outs resulting in ‘firefighting’. This paper looks at the engineering and technical services required to maintain smooth production with the aim of developing an inventory control system for the efficient utilization of resources. A work study was carried out at a tube and pipe manufactur...
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Various dynamic factors impact the movement of materials within a manufacturing environment, increasingly becoming complex for multi-product assembling plants owing to the multiplicity and interconnectedness of these factors. Analyzing these factors can be equally complex, requiring modelling and simulation tools. This paper looks at the modelling...
Conference Paper
Full-text available
Foundry industry technologies have evolved over the years largely due to rapid changes in technology resulting in complexities that require careful planning and organization. materials in the foundry industry pass through various stages and a number of factors, ranging from preparation of charges, materials handling and routing, furnace and product...
Conference Paper
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Most mineral processing companies are energy intensive especially if smelting is used in extraction. After processing, the energy is correspondingly dissipated as heat and toxic gases, requiring stringent controls for sustainability and safety. In recent years, Southern Africa has grappled with power shortages resulting in the scaling down of compa...
Conference Paper
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One of the most critical requirements for safety in vehicles is the availability of reliable braking systems. Most heavy vehicles in Zimbabwe employ the conventional hydraulic braking system. However changes and improvements in technology have seen the introduction of retarders that make use of magnets and eddy currents. The new technology is frict...
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Engineering equipment in some Higher Education Institutions (HEIs) in Sub-Saharan Africa is underutilized, obsolete or in poor working condition owing to lack of expertise, aging or maintenance-related challenges respectively. A research initiated by the Network of Users of Scientific Equipment in Eastern and Southern Africa (NUSESA) and funded by...
Conference Paper
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Production of engineering drawings have evolved from manual to Computer Aided Design (CAD), primarily for the speed and accuracy presented by CAD. Unlike modelling and simulation packages that are equipped with building blocks, CAD packages are generally supplied with no pre-drawn symbols. From best practices in industrial engineering and working f...
Conference Paper
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Proprietary softwares are often used for structural control in engineering. Nonlinear structural control researches often uses nonlinear finite element toolbox (NLFET) code which was specifically developed for coding and simulations of structures. This paper provides an overview of the use of NLFET including the data structures and algorithms used...
Conference Paper
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Customer perceptions of products continuously change over time. Marketing specialists are generally tasked with the responsibility of rebranding and product changes. However this is normally technology driven, with inputs from engineering designers and manufacturers providing the designs and feasibilities for either modifying existing designs or de...
Conference Paper
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Systems that are simulated are generally made up of one or more elements that have some uncertainty associated with them. These systems may eventually evolve in a manner that is not completely predictable and thus become stochastic in nature. Simulation of stochastic systems requires that the variability of the elements in the system be characteriz...
Conference Paper
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The proper layout and efficient utilization of resources; human, machinery and space can have a positive bearing on the productivity of manufacturing companies. A case study was carried out at a furniture manufacturing plant in Harare, Zimbabwe and this paper presents the findings and proposals for an optimized plant layout and materials handling s...
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Grade 5 titanium alloy (Ti6Al4V) is considered as the workhorse material when it comes to automotive and aerospace applications. It is widely referred to as an aerospace alloy and is a relatively new engineering material. The main attraction of this material is its high strengthto-weight ratio when compared to such common engineering materials as s...
Conference Paper
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An acute shortage of appropriately-skilled engineers constrains economic growth and hinders sustainable development. This challenge is shared by most countries in Southern Africa, albeit at different scales. Recession in the region at the turn of the new millennium led to an exodus of experienced professionals, including engineers, seeking work abr...
Conference Paper
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Research has found out that southern Africa lacks in engineering capacity. This is attributed not only to low numbers of qualified engineers but insufficient skills and experience held by some of the few local engineers. This is compounded by the fact that the majority of institutions that offer engineering training in Southern Africa have out date...
Conference Paper
Full-text available
Southern Africa suffers from a serious and persistent lack of engineering capacity according to studies conducted in Malawi, Mozambique, Rwanda, South Africa, Tanzania and Zimbabwe. This is attributed not only to low numbers of qualified engineers but insufficient skills and experience held by some of the few local engineers. This is compounded by...
Article
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The application and use of EdenLISP in mechanism design and analysis is demonstrated on the tipping mechanism of a dump truck. The foundation for mechanical engineering design is centred on mechanisms, their design operation and strength. Several design programs have been developed to assist the engineer in the product development cycle. This paper...
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Persistent fatigue failure observed in vibrating screen side plates motivated this investigation to determine the effects of plasma cutting on the surface integrity and hence fatigue performance of mild steel plates. Fatigue crack initiation and propagation was reported to have occurred in a number of vibrating screen side plates in which bolt hole...
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This research study seeks to examine the improvements accrued by adopting production planning for a food processing organization in Zimbabwe. Relevant key performance indicators (KPIs) were considered to achieve set goals and targets. Production planning and control recommendations synchronized inputs, processes and out outputs to achieve greater l...
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Advanced and modern manufacturing systems are often characterised by a high degree of automation and are usually quite complex. This complexity is mainly due to the numerous possible interactions between the system’s components, and the difficulty of determining the optimum set of parameters to satisfy system requirements. This invariably creates p...
Conference Paper
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The SADC regional programme of WaterNet draws its membership from university departments and research institutions from 17 countries in Eastern and Southern Africa that are involved in education, training, research and outreach in Integrated Water Resources Management. WaterNet is governed by its members through the WaterNet Trust and managed on a...
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A facility for the automatic generation of bills of materials from CAD drawings under development is proposed and has been tried out at a vehicle manufacturing plant in Zimbabwe. Most engineering and manufacturing companies’ design and estimation functions are operated independently, leading to costly delays before completed drawings and estimation...
Conference Paper
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Modelling and simulation tools are critical for understanding system complexities, predicting system performance and are often valuable for system management. This paper reviews the techniques and role of modelling and simulation in assisting decision-makers in the manufacturing sector. Manufacturing organisations, the world over, are continuously...
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The use of 2 dimensional sketching as a modelling tool is assumed to be well understood as it is the base on which engineering and technical drawing are taught, but the potential of 3 dimensional modelling is much less exploited. This paper reviews the basics of three-dimensional modelling in general and then delves into the aspects of one of the m...
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Mechanical engineering design is mainly centered on mechanisms, their design operation and strength. Hence programs for aiding the design process are continually being developed. This paper demonstrates on how a mechanism can be modelled and analysed using AutoLISP, an interface language as well as an integral part of AutoCAD. Initially the mechani...

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