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Life cycle assessment of a coal-fired old thermal power plant

- Mbohwa, Charles

  • Authors: Mbohwa, Charles
  • Date: 2013
  • Subjects: Greenhouse gas reduction , Life cycle assessment , Thermal power plants - Environmental aspects , Environmental impact assessments
  • Type: Article
  • Identifier: uj:4870 , ISBN 978-988-19251-0-7 , http://hdl.handle.net/10210/12546
  • Description: This paper discusses a life cycle analysis of a thermal power plant to quantify environmental impacts of thermal power production at an old power plant. Coal is used in electricity generation worldwide and many power plants in developing countries are very old. Knowing the life cycle environmental impacts of such power plants is very important since they produce a lot of greenhouse gases. This paper develops life cycle inventories for an old power plant in Africa and identifies ways to minimize coal consumption for the same capacity of power output. A life cycle assessment (LCA) was done for the power plant. The emitted carbon dioxide, sulphur dioxide, nitrous oxides and solid waste have adverse effects on flora, fauna, water bodies and humans. A number of environmental metrics were obtained for the thermal power plant and these form the basis for future comparative and extended studies.
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The effect of human capital investment and motivation on miners’ productivity at a South African Platinum mine

- Makhubedu, Lucky Boy Tebogo, Nwobodo-Anyadiegwu, Eveth Nkeiruka, Mbohwa, Charles

Biogas use as fuel in spark ignition engines

- Kukoyi, T.O., Muzenda, E., Akinlabi, Esther Titilayo, Mashamba, A., Mbohwa, Charles, Mahlatsi, T.

Value addition of coal fines and sawdust to briquettes using molasses as a binder

- Manyuchi, M. M., Mbohwa, Charles, Muzenda, E.

Barriers of sharing tacit knowledge : A case of Gauteng agricultural SMMEs, South Africa

- Seseni, Lawrance, Mbohwa, Charles

Feasibility study of the materials handling and development of a sustainable conveying system in plastics recycling and manufacture

- Chinguwa, Simon, Nyemba, Wilson R., Boora, Kudzai, Mbohwa, Charles

Method of lines based on finite element technique to analyse electromagnetic problems

- Mushiri, Tawanda, Mbohwa, Charles

  • Authors: Mushiri, Tawanda , Mbohwa, Charles
  • Date: 2015-03-03
  • Subjects: Method of lines , Computational electromagnetics , Variational analysis , Finite element method
  • Type: Article
  • Identifier: uj:5159 , http://hdl.handle.net/10210/14291
  • Description: A hybrid scheme called finite element method of lines is described and proposed for modelling and analysis of generalized computational electromagnetic problems with emphasis on a number of irregular waveguide. This finite element based method of lines is developed by combining finite element method and the method of lines, so that it not only has high flexibility to treat geometrically and compositionally complex problems but also maintains high accuracy of semi-analytical technique. Analytical and numerical algorithmic building blocks of this new scheme are discussed such as geometry discretization, element mapping, element trial functions, reformulation and computational issues of non-linear ordinary differential equations. The results therefore show that this new technique is able to efficiently solve complex problems as compared with the conventional method of lines. MATLAB was used to compute the solutions of various problems.
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Home care staff planning and scheduling an integrated operations management perspective

- Mutingi, M., Mbohwa, Charles

  • Authors: Mutingi, M. , Mbohwa, Charles
  • Date: 2013
  • Subjects: Health care management , Healthcare staff scheduling , Home health care scheduling
  • Type: Article
  • Identifier: uj:6173 , http://hdl.handle.net/10210/13780
  • Description: The Home Health Care (HHC) sector continues to grow at an increasing rate across the globe. As such, developing proper health care management systems and operations strategies is essential for survivability, growth and competitiveness of healthcare systems. As labor is the most critical asset in the home care organizations, it is crucial to obtain an in-depth understanding of HHC operations, from an operations management view point, with specific emphasis on staff planning and scheduling. The aim of this paper is to provide a taxonomic analysis of HHC staff planning and scheduling decisions, from an operations management perspective. We identify from various cases in the literature, the core activities characterizing staff planning and scheduling. We then present a taxonomic analysis of these activities, and propose an integrated approach to decision making. A conceptual modeling framework is then proposed to assist the decision maker in solving problems in HHC staff planning and scheduling.
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Design of a ferrochrome – slag mechanical separator : case study

- Gudukeya, Loice Keresia, Mushiri, Tawanda, Mbohwa, Charles

Ore processing by PGM concentration process and assessment of CO2 equivalent emissions and environmental damage directly involved

- Mabiza-ma-Mabiza, Junior, Mbohwa, Charles

  • Authors: Mabiza-ma-Mabiza, Junior , Mbohwa, Charles
  • Date: 2016
  • Subjects: Bushveld complex , Direct environmental damages , Platinum group metals
  • Language: English
  • Type: Book Chapter
  • Identifier: http://hdl.handle.net/10210/124047 , uj:20867 , Citation: Mabiza-ma-Mabiza, J. & Mbohwa, C. 2016. Ore processing by PGM concentration process and assessment of CO2 equivalent emissions and environmental damage directly involved.
  • Description: Abstract: Platinum group metals are more and more pointed out as key players to contribute to addressing the making headway issues of environmental damage impacts through technological innovations. Of immediate past, interest in hydrogen has grown rapidly resulting to the development of the concept of hydrogen economy to address two growingly noticed challenges namely climate change impacts due to GHG emissions and the need for clean energy, security and sustainability supply. The recognitions to PGM are of without a doubt, but goings-on around PGM recovery process are reported with environmental concerns; the best known are identified as land transformation, livestock and wildlife affected by use of chemicals and other non-renewable resources. Life cycle assessment analysis of ore-concentration was developed and equivalent carbon dioxide emissions quantified. One tonne of Ore-based PGM Concentrates, a total amount of equivalent carbon dioxide of about 1.574,96 kg CO2-eq was associated with this process. In an annual initiative, the concentrator can process up to 36,547 million metric tons of ore milled accounting for 57.5 million kg CO2-eq. Important emissions in this phase are waterborne and emissions to soil.
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Environmental impacts assessment of the platinum nanophase composite electrode by Eco-indicator 99 methodology

- Mabiza, Junior M., Mbohwa, Charles, Mutingi, Michael

  • Authors: Mabiza, Junior M. , Mbohwa, Charles , Mutingi, Michael
  • Date: 2012
  • Subjects: Environmental impact assessments , Eco-indicator 99 , Platinum nanophase composite electrodes
  • Type: Article
  • Identifier: uj:6018 , http://hdl.handle.net/10210/10033
  • Description: Platinum nanophase composite electrode for hydrogen generation by water electrolysis process has to meet sustainable development requirements even in its development phase by reducing GHG emissions to irrelevance. It is therefore important to determine possible emissions, to estimate the energy consumption and identify key parameters in the improvement of the process used to develop the electrode. Eco indicator 99 was used to assess and determine the types of impacts on the environment of the process of the preparation of the composite electrode and Umberto software was used to develop life cycle assessment inventory (LCIA).
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The impact of technology on small, micro and medium scale enterprises in Gauteng South Africa

- Agwa-Ejon, John, Mbohwa, Charles

Identifying the effects of excessive deflection in reinforced concrete beam

- Ogbeifun, E, Pretorius, J. H., Mbohwa, Charles

  • Authors: Ogbeifun, E , Pretorius, J. H. , Mbohwa, Charles
  • Date: 2014
  • Subjects: Reinforced concrete construction , Concrete beams , Floors, Concrete - Design and construction
  • Type: Article
  • Identifier: uj:5084 , http://hdl.handle.net/10210/13655
  • Description: In framed reinforced concrete structure, the beams transfers the dead and live loads to the column and then to the foundation. When there are observed structural failure in the systems supported by the beam, especially where the beam has a large unsupported clear span at a lower level, before any further detailed investigations are initiated, the functional state of the beams should be ascertained. The correct diagnosis of the source of problem is essential for the design of effective rehabilitation scheme. Simple visual inspection corroborated with field test for true horizontality of the beam can provide the lead information that will guide the client on the scope of further investigations. The case study method of qualitative research was adopted to address the research questions, while the research data was collected by reviewing previous investigation reports on a three-storey building, physical inspection and conducting simple site experiment to identify the lead information. The research outcome reveals that the multiple cracks observed in the partition walls especially in the second floors were as a result of excessive deflections in the beams supporting the first and second floors. Based on recommendation, subsequent investigation confirmed this lead information and appropriate rehabilitation scheme was adopted.
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Application of Total Quality Management (TQM) in the South African banking sector : the case of First National Bank (FNB) in South Africa

- Edoun, Emmanuel Innocents, Mabisa, Junior, Mbohwa, Charles, Pelser, Ruan

Used Vegetable Oil (UVO) as a feedstock for biodiesel production in South Africa

- Thaba, Sebonkile Cynthia, Mbohwa, Charles

Production planning and control of a master churn mixer for the manufacture of margarine using fuzzy logic at an oil company in Zimbabwe

- Nyemba, Wilson R., Mushiri, Tawanda, Mugwindiri, Kumbi, Mushonga, Roy, Mbohwa, Charles

Business process re-engineering : a look at the business account opening process at MNM Bank

- Flowers, Vincent, Mbohwa, Charles

  • Authors: Flowers, Vincent , Mbohwa, Charles
  • Date: 2013
  • Subjects: Business process reengineering , Reengineering (Management) , Total quality management , Banks and banking - Customer services
  • Type: Article
  • Identifier: uj:4888 , http://hdl.handle.net/10210/12602
  • Description: The account opening process is recognised as the most critical service if banks want to retain and build long term relationships with clients. An unsatisfactory customer experience during this process can influence the customer’s perception of the organisations overall service. Organisations are under increased pressure to deliver products in an efficient and effective manner with a reduction in cost. Having a competitive advantage in the account opening process will attract customers and create future sales opportunities. Future sales opportunities lead to growth and growth leads to increased profits. The research provides an insight on the current account opening process and challenges encountered within the process. The objective of the research is to examine literature and improve the account opening process at MNM bank. The existing account opening process takes 7.5 days before the customer can transact on their account, which results in customers seeking an account at a competitor bank.
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Evaluating Maintenance Strategies Effectiveness on Overall Equipment Utilization

- Bupe, G Mwanza, Mbohwa, Charles

  • Authors: Bupe, G Mwanza , Mbohwa, Charles
  • Date: 2016
  • Subjects: Maintenance , Equipment Utilization , Effectiveness
  • Language: English
  • Type: Conference Proceedings
  • Identifier: http://hdl.handle.net/10210/93052 , uj:20303 , Citation:Mbohwa, C. & Mwanza, B.G. Evaluating Maintenance Strategies Effectiveness on Overall Equipment Utilization.
  • Description: Abstract: The performance and competitiveness of manufacturing companies is dependent on the reliability, availability and productivity of their facilities. To ensure the plant performance achievability, maintenance managers need to have a good understanding about the maintenance systems’ effectiveness. The company understudy had been experiencing frequent breakdowns of critical machines, which negatively affected productivity. The researchers set objectives to establish the causes of machine breakdown, determine the level of plant utilization and availability, evaluate the percentage of sales lost due to downtime and determine the level of Mean-Time To Repair (MTTR). The hypothesis tests developed were based on the mentioned objectives as the major indicators of maintenance effectiveness. Direct observations, structured interviews, company records and published work were used to collect data. Spreadsheet modelling and Mega Stat were used for analysing the data. The results came double folded indicating that breakdown maintenance was not effective as it underutilized the plant’s equipment, lowered plant availability, decreased the sales and increased the level of MTTR.
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Management of the humanitarian supply chain in Zimbabwe

- Chingono, Tatenda T., Mbohwa, Charles

  • Authors: Chingono, Tatenda T. , Mbohwa, Charles
  • Date: 2015
  • Subjects: HIV/AIDS , Humanitarian supply chain , Zimbabwe
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/72192 , uj:18249 , Citation: Chingono, T.T. & Mbohwa, C. 2015. Management of the humanitarian supply chain in Zimbabwe.
  • Description: Abstract: These The supply chain management system is also not well defined (UNIDO, 2011) interruption of supply of antiretroviral is a major challenge to the national program. Supply interruption will increase the risk of treatment failure and development of ARV resistance, hence there is a need to strengthen the current supply chain and logistics so as to reduce the risk of stock outs and to also strengthen the capacity of the government of Zimbabwe to absorb the high volumes of HIV/ AIDS commodities from the global fund and other donors according to the UNIDO (2011) global project report The study mainly used primary data collection method including a survey and interview. Secondary data from the literature review, was also complimented by semi-structured interviews with management and personnel in the organizations studied. Solutions and recommendations were then identified in order to attend to the identified deficiencies, problems and challenges.
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Design of a mechanical cleaning device P.I.G (pipeline intervention gadget) connecting two transfer lines in Zimbabwe

- Mushiri, Tawanda, Ndlovu, Stephen, Mbohwa, Charles

  • Authors: Mushiri, Tawanda , Ndlovu, Stephen , Mbohwa, Charles
  • Date: 2016
  • Subjects: Pipeline intervention gadget , Pipeline , Design
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/213988 , uj:21222 , Citation: Mushiri, T., Ndlovu, S & Mbohwa, C. 2016. Design of a mechanical cleaning device P.I.G (pipeline intervention gadget) connecting two transfer lines in Zimbabwe.
  • Description: Abstract: In the Oil and Gas Industry, maintenance is done using a device or tool called a pig, chiefly to remove solids, dirt, and liquids from the pipelines. The aim of this work is to design and retrofit a pig which will clean 3 identical underground transfer pipelines linking 2 depots The movement of this tool is basically through the action of the fluid in the pipeline pushing it along as it is pumped from one point to another, hence no external power is needed in the device to help in its movement. Calculation based model analysis of the tool together with Solidworks simulations and results are included in detail, with all assumptions and limitations clearly stated and listed. The results show that the pig will move inside the pipe at a lower speed than the mean flow velocity which is good for the performance of the electronic systems installed on its body for pipeline inspection. Bypass hole is added on the central part of the pig body to control the speed as well as keep the cleaned dirt stirred and moving, being pushed by the pig as it performs its cleaning process.
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