Browsing Faculty of Engineering and Technology by Title
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Oladiran, M.T. (Elsevier Science Ltd, http://www.elsevier.com/wps/find/journaldescription.cws_home/405891/description#description, NaN, 1995)[more][less]
Abstract: The use of solar energy is well established for low-grade thermal applications such as water heating and purification. In many of the solar systems, the collector surface located in the Northern Hemisphere faces the true south direction. However, there are occasions in which the radiation received by the collector at various orientations is desirable, such as a collector incorporated with a tracking system. The data for such situations are not available for several solar farms in Nigeria. Consequently, in this study, the average global radiation on flat surfaces was determined for three zones in Nigeria. The total insolation was obtained while the surface azimuth angle was varied between 0° and 75° at 15° intervals. The results are presented for three inclinations of the collector surface, namely L − 10, L, and L + 10 degrees respectively. URI: http://hdl.handle.net/10311/671 Files in this item: 1
Oladiran_AE_1995.pdf (1.847Mb) -
Foster, J.D.G.; Uziak, J.; Loukanov, I.A. (Blackwell Publishing Ltd, http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1475-1305, NaN, 2009)[more][less]
Abstract: This study presents the experimental setup and results of measurement of forces and moments in a manually operated ram press machine. Tests were conducted on a BP30 ram press using electrical resistance strain gauges to measure forces present in the machine under operating conditions. The forces were obtained by capturing data for the strains in six channels, using a digital instrument system, and later calculated by using the sensitivity factors. A method was proposed to estimate the tension force and bending moment in the connecting rods based on the sums and differences of measured strains. Results obtained were converted into spreadsheet data and presented in graphs versus the position angle of the operating lever. URI: http://hdl.handle.net/10311/633 Files in this item: 1
Foster_SIJEM_2009.pdf (460.1Kb) -
Garg, A.K.; Joubert, R.J.O.; Pellissier, R. (College of Economic and Management Sciences, University of South Africa. http://www.unisa.ac.za/default.asp?Cmd=ViewContent&ContentID=16434, NaN, 2004)[more][less]
Abstract: Most studies consider business performance to be a multidimensional construct. Four dimensions (namely, business growth, profitability, image and customer loyalty, and product service innovativeness) were hypothesised to validate a measure for business performance in the South African context. Using partial least squares, 22 responses from top executives of banks in South Africa were analysed to test the validity of the four dimensions of business performance. The results of the study suggest that the nonfinancial dimensions (namely, image and customer loyalty, and product service innovation) are not valid dimensions for measuring business performance, while the other two dimensions (namely, business growth and profitability) show a high degree of correlation. This indicates that business growth is aligned with profitability, that growth for profitability is a major concern, and that profitability still remains the key measure of business performance in the South African banking sector. Parameters such as customer loyalty and innovativeness are not regarded as important for business performance, although these could be pressing issues for banks. The paper also validates a questionnaire that can be used to measure business performance and reviews various methods for measuring business performance. URI: http://hdl.handle.net/10311/296 Files in this item: 1
Garg_SAJBR_2004.pdf (188.9Kb) -
Malumbela, G.; Alexander, M.; Moyo, P. (Elsevier http://www.elsevier.com/locate/conbuildmat, NaN, 2011)[more][less]
Abstract: Cracking of the cover concrete due to steel corrosion is considered by many researchers to indicate the end-of-service life of corrosion-affected reinforced concrete (RC) structures. Numerous models have been developed to predict the time from corrosion initiation to cracking of the cover concrete. In the previous models, concrete with corroding steel bars was assumed to behave like a thick-walled cylinder under uniform internal pressure. Recent research publications have however, shown that steel corrosion is often concentrated on the surface of the steel that faces the direction of ingress of corrosion agents. This paper presents a model that relates the level of partial surface steel corrosion with the transverse and vertical strains measured on the exterior faces of corrosion-affected RC beams. The model assumes that the remaining section of the steel after corrosion is elliptical shaped. Finally, the model is calibrated with experimental data in the literature and it is shown that assuming uniform steel corrosion underestimates the internal pressure applied by the expansive corrosion products. URI: http://hdl.handle.net/10311/682 Files in this item: 1
Malumbela2_CBM_2011.pdf (481.3Kb) -
Marumo, R.; Tokhi, M.O. (University of Botswana, Faculty of Engineering and Technology, http://ajol.info/index.php/bjt, April NaN, 2007)[more][less]
Abstract: This article proposes a new modeling scheme using extended radial basis function (RBF) and adaptive neuro-fuzzy filter for handling nonlinear uncertainties of an air motor servo valve. This model combines the fast model development ability of RBF and the adaptation capability of adaptive neuro-fuzzy inference system (ANFIS) used instead of the well known conventional modeling techniques. The ANFIS structure provided parameter partitioning and better performance under transient response to handle the problem of disturbance attenuation. The pneumatic H-bridge, characterizing a pneumatic servo valve has been devised for speed and direction control of the motor and the system characteristics conveniently divided into three main regions; of low speed (below 390 rev/min), medium speed (390 to 540 rev/min) and high speed (540 to 680 rev/min). The system is highly non-linear in the low speed region and hence the need to use an adaptive intelligent based modeling technique arises. Simulation results has proven that for an air motor system with uncertainty and perturbed noise, the RBF-ANFIS model scheme performed well and out past its conventional counterpart by far. URI: http://hdl.handle.net/10311/657 Files in this item: 1
Marumo_BJT_2007.pdf (5.657Mb) -
Mark, M. (University of Botswana, http://ub.bw, NaN, 2007)[more][less]
Abstract: Botswana is facing one of its greatest development challenges at the moment. It is facing an HIV/AIDS pandemic of immense proportions. It is among the countries in the world that have been hard hit by this scourge. A lot of stakeholders including government, private companies, international donor agencies, and civil society have come up with interventions to respond to challenge of fighting this pandemic. Among the key players in this fight against HIV/AIDS are civil society organizations, commonly known as NGOs. These organizations play a crucial role of bringing HIV/AIDS services to the communities where the other players may not reach or may not be effective. The services the NGOs offer to communities are normally delivered as projects. Effective monitoring and evaluation of projects is usually one of the ingredients of good project performance and provides means of accountability, demonstrating transparency to the stakeholders and facilitates organizational learning for benefit of future projects. This study sought to determine how effectively the HIV/AIDS projects implemented by Gaborone based local NGOs are monitored and evaluated. The study investigated the monitoring and evaluation practices of the NGOs and compared them with the best practices. It also sought to identify the challenges the NGOs faced in carrying out this function. Data for the study was collected using the descriptive survey method where a questionnaire was administered to project managers and monitoring and evaluation officials of the NGOs. The results of the study show that most of the NGOs (66.7%) were implementing Behavioral Change Communication projects. The study also determined that the monitoring and evaluation practices of the local NGOs fell short of the best practices. Most of the best practices were inconsistently done and others were not done at all. Planning for monitoring and evaluation was inadequately done and inconsistently by respondents. Implementing the monitoring and evaluation process was not effectively done by the respondents. The study also identified quite a number of challenges the NGOs faced in carrying out monitoring and evaluation of the projects they faced. These challenges made it hard for the NGOs to effectively monitor and evaluate the projects they implemented. The most significant ones included; inadequate finances, lack of expertise, stringent and multi-donor reporting requirements, lack of baseline data. The study made some recommendations in order to mitigate the challenges faced by the NGOs. The study found out that, all in all the projects implemented by the local NGOs were not effectively monitored and evaluated. URI: http://hdl.handle.net/10311/991 Files in this item: 1
Mark-MEPC_2007.pdf (7.970Mb) -
Malumbela, G.; Sebusang, N. (Faculty of Engineering and Technology, University of Botswana, www.ub.bw, April NaN, 2011)[more][less]
Abstract: Concrete is the widely used construction material worldwide. Therefore, for structural safety as well as to provide economic design, it is essential to understand well, its performance. Whilst in most developed countries extensive research has been done to characterise concrete, little is known about the performance of concrete in Botswana. This paper reviews previous work carried out in other countries to assess performance of their concrete. Focus is on influence of aggregate type. It is shown from the review that there is great need to study influence of aggregate on performance of concrete in Botswana, particularly comprehensive strength. A brief description of the needed research is outlined. URI: http://hdl.handle.net/10311/889 Files in this item: 1
Malumbela_BJT_2011.pdf (934.5Kb) -
Masoso, O.T. (Elsevier http://www.linkinghub.elsevier.com/retrieve/pii/S0378778808000923, NaN, 2008)[more][less]
Abstract: This paper presents the findings of a case study with building simulation using EnergyPlus dynamic thermal simulation software, in which wall insulation was varied together with cooling set-point temperature in a hot and dry climate of Botswana. Against the established norm that adding wall insulation reduces annual fuel consumption, it is shown in this paper that this is not always the case: there are instances where adding wall insulation directly increases annual fuel consumption. Initial cost of insulation aside, as the cooling set-point temperature is gradually increased, the building switches from an ‘‘insulation reduces cooling load’’ to an ‘‘insulation increases cooling load’’ behaviour. In other words, the well established knowledge that ‘‘the lower the u-value the better’’ gets overridden by ‘‘the higher the u-value the better’’. We termed this a ‘‘point of thermal inflexion’’. Simple graphical demonstration of the existence of this point is presented in the paper. According to the findings, design engineers and building economics related professionals who quantify investment on insulation can get disastrous results if they assume that all buildings behave pro-insulation since a building may behave anti-insulation. URI: http://hdl.handle.net/10311/673 Files in this item: 1
Masoso_EB_2008.pdf (867.2Kb) -
Nedović-Budić, Z.; Knaap, G.; Budhathoki, R.N.; Cavrić, B. (Urban and Regional Information Systems Association, http://www.urisa.org/, NaN, 2009)[more][less]
Abstract: This paper presents an assessment of the regional capacity in implementing geographic information systems (GIS) and databases. We draw on a Web survey to determine the availability and assembly of spatial data at the metropolitan level in the United States. Information was sought from 388 planning organizations and regional agencies located in 349 metropolitan areas. Based on 116 responses (30 percent response rate), we generate descriptive statistics and run a regression model addressing the following aspects of the regional GIS capacity: data (contents, update, and assembly); technology (compatibility of software and data formats, data access, and the use of standards); people (staff, leadership commitment and support, regional communication and cooperation); policy (data sharing, funding, rules and responsibilities, and mandates/programs); and context (urban and regional issues and affluence). Although the survey reveals only a snapshot of a dynamic and evolving phenomenon, the results indicate that the status of metropolitan GIS in the United States may not be matching what is technically feasible. While the capacity is getting better over time, the process is relatively slow and the challenges of creating the base for building the National Spatial Data Infrastructure (NSDI) are persistent. Future research and practice should place more emphasis on the relationship between the NSDI and its installed base. Nurturing of networks and compatibilities among organizational entities at various levels, local and regional in particular, should be given priority in devising policies and programs for a useful and sustainable spatial data infrastructure. URI: http://hdl.handle.net/10311/1022 Files in this item: 1
cavric2009BUILDINGBLOCKS.pdf (2.681Mb) -
Raju, V.C.C. (University of Botswana, NaN, 1998)[more][less]
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Inambao, F.L.; Mosweu, M. (University of Botswana, NaN, 2001)[more][less]
Abstract: Diesel engines are used in heavy duty applications because of their high effeciency an reliability. However, oxides of nitrogen emissions remain a major concern. In diesel engines, fuel combustion is responsible for a major proportion of oxides of nitrogen emissions. Four sources of the oxides have been identified. The range of possible types of damage to environment and health, as well as effective methods for reduction of oxides of nitrogen, have been analysed. URI: http://hdl.handle.net/10311/620 Files in this item: 1
Inambao_BJT_2001.pdf (1.720Mb) -
Cavrić, B.I.; Toplek, S.; Šiljeg, A. (Clanak, NaN, 2008)[more][less]
Abstract: Over the last two decades, there has been an intensive discourse and research about measuring sustainable urban development. Many cities, regions and countries have decided to introduce indicators for monitoring and measuring the progress towards sustainability. Today there is a wide spread perception that information on the environment in general, and urban environment in particular, is the determinant of effective rational decisions and allocation of resources. Such information would enable planners and decision makers to formulate redistributive policies and programmes to address some of the disparities that exist in a post-socialist city. Cities of the post-socialist world characterized by sharp disparities, socio-economic contrasts and environmental degradation provide an excellent laboratory for tracing information on the quality of urban life. The current situation in the emerging Croatian coastal city of Zadar reflects the diversity of the post-socialist urban change in a very fragile Mediterranean landscape. This paper takes a critical look at sustainable development and its measurements. It describes the participatory approach through which different local communities in Zadar were evaluating quality of life based on basic pillars of sustainable development. The identification and collection of their opinions provide valuable data base and community input into urban governance and development planning decision making. URI: http://hdl.handle.net/10311/641 Files in this item: 1
cavric2008SPATIUM.pdf (2.200Mb) -
Kalabamu, F. (Elsevier www.elsevier.com/locate/landusepol, NaN, 2006)[more][less]
Abstract: Patriarchy has been defined as a gendered power system: a network of social, political and economic relationships through which men dominate and control female labour, reproduction and sexuality as well as define women’s status, privileges and rights in a society. Taking Botswana as a case study, this essay examines the effects of patriarchy on women’s access, control and ownership of land in southern Africa. It notes that while women were largely excluded from land ownership during the pre-colonial era, patriarchy has since been selective on the type and nature of land rights that women may enjoy. The essay argues that the weakening of traditional patriarchal structures, attitudes and practices in Botswana is a result of women’s self-empowerment, economic transformations and the replacement of chieftainship with democratic institutions. It ends by noting that despite the apparent weakening of pre-colonial institutions and attitudes, there have emerged new forms of female subordination, which require vigilance and constant exposure. URI: http://hdl.handle.net/10311/630 Files in this item: 1
kalamu2006PATRIARCHY.pdf (967.9Kb) -
Uziak, J.; Loukanov, I. A. (CIGR Journal http://www.cigrjournal.org/, NaN, 2007)[more][less]
Abstract: The ram-press technology for oil expression has received a lot of attention in many African countries during the last two decades. The technology is based on manually operated mechanical presses, which employ a slider-crank mechanism in two different configurations. The original machine was invented by Karl Bielenberg in 1985 and since then continuous design improvements have been made to improve their performance and ease of operation. This paper deals with the performance of some commonly used ram press machines such as BP-35, BP-30 and FI-32, in order to establish their suitability for small rural oil expression technology. The available oil-seed processing techniques were discussed, including their suitability for locally grown sunflower varieties, and the characteristics of the ram press machines. The machines were tested by using three varieties of sunflower seeds, namely PNR 7225, PNR 7369, and Peredovik. The machines were compared by their outputs obtained when conducting a high production and high expression tests. Based on the above analysis the Camartec design (BP-30) was found to have the best performance. The machine had the highest efficiency and also the highest expression rate in comparison to CAPU design (BP-35) and RAM design (FI-32) machines. The FI-32 machine was found to be ineffective, having in the high expression test an expression rate below 20% irrespective of the type of seeds used. In terms of the speed of oil production the CAPU (BP-35) design performed better then the other machines. However in the high production test its performance was similar to that of Camartec machine. URI: http://hdl.handle.net/10311/697 Files in this item: 1
Uziak_AEI2_2007.pdf (989.2Kb) -
Garg, A.K.; Van Tonder, R.; Joubert, R.J.O. (Inderscience Enterprises Ltd. http://www.inderscience.com/browse/index.php?journalID=235, NaN, 2007)[more][less]
Abstract: In order to analyse the strategic issues with regard to the South African Platinum Group of Metals (PGM) industry, a risk analysis and an assessment of the competitiveness of the industry were conducted. The analysis of risk related to market conditions indicates a relatively low risk rating driven by increased demand for jewellery and autocatalysts, while the industry is exposed to moderate risk for raw materials and supporting services, which is expected to remain moderate in future. Overall, the current risk for production factors was found to be moderate and is expected to remain moderate over the medium term. The results of industry risk analysis indicate that the PGM industry is currently exposed to moderate risk. Applying Porter’s diamond model (Porter, 1990), the research found that the South Africa’s PGM industry has a very strong platform and is expected to become more competitive in future, although increased cooperation will still be evident. The competitiveness of South African producers is expected to increase over the medium term, since most of the expansion will come on stream in the near future. The paper also discusses the development potential of South Africa in line with the exploitation of PGM. URI: http://hdl.handle.net/10311/295 Files in this item: 1
Garg_IGICBM_2007.pdf (2.472Mb) -
Mothibi, J.; Kutua, S. (University of Botswana, www.ub.bw, NaN, 2001)[more][less]
Abstract: One of the critical elements that determine the competitiveness of nations is the population density of, and quality of its engineers. This view has been corroborated by researchers such as Biluch (1989), Garelli et al (1997), and Gharajedaghi (1986). Unfortunately most African countries are not performing well on this front. Engineering education institutions, entrusted with the task of improving the measures, find themselves in the uneviable position of attempting to operate in environments in which governments are continuously reducing funding to education in general. The objective of this paper is to develop conceptual models which can aid engineering institution overcome the financial constraints, increase throughput of engineers, and improve the quality of engineering education. The model is based on the cybernetics paradigm and is validated through structural and multiplicative corroboration. URI: http://hdl.handle.net/10311/825 Files in this item: 1
Mothibi_BJT_2001.pdf (725.3Kb) -
Mothibi, J.; Kutua, S. (University of Botswana, Faculty of Engineering and Technology, http://ajol.info/index.php/bjt, October NaN, 2001)[more][less]
Abstract: One of the critical elements that determine the competitiveness of nations is the population density of, and quality of, its engineers. This view has been corroborated by researchers such as Bilich (1989), Garelli et al (1997), and Gharajedaghi (1986). Unfortunately, most African countries are not performing well on this front. Engineering education institutions, entrusted with the task of improving these measures, find themselves in the unenviable position of attempting to operate in environments in which governments are continuously reducing funding to education in general. The objective of this paper is to develop a conceptual model which can aid engineering institutions overcome the financial constraints, increase throughput of engineers, and improve the quality of engineering education. The model is based on the cybernetics paradigm and is validated through structural and multiplicative corroboration. URI: http://hdl.handle.net/10311/663 Files in this item: 1
Mothibi_BJT_2001.pdf (3.126Mb) -
Kanyeto, O.J.; Fried, A.N. (Faculty of Engineering and Technology, University of Botswana, www.ub.bw, April NaN, 2011)[more][less]
Abstract: The paper aims to compare predictions by different methods of analysis of the lateral load capacity of unreinforced masonry walls, and to determine whether a relationship can be drawn between theory and experiments. Several analysis methods were employed to predict failure loads of a number of wall panels, and the results were compared with test values. It is concluded that boundary conditions play a major role in the accuracy of analytical methods. When the boundary conditions assumed in the analysis most nearly match the real conditions of the test panels, predictions are most accurate. The authors conclude that finding a rational analysis and design procedure for laterally loaded masonry walls is possible. URI: http://hdl.handle.net/10311/890 Files in this item: 1
Kanyeto_BJT_2011.pdf (1.581Mb) -
Moalosi, R.; Popovic, V.; Hickling-Hudson, A.R. (Chinese Institute of Design, http://www.ijdesign.org, NaN, 2007)[more][less]
Abstract: Products designed and manufactured in any country are influenced by local factors, such as the availability of raw materials, human skills, tradition, and socio-cultural values. The tendency to use available natural resources is in harmony with the eco-system. It is expected that culture plays a crucial role in designing contemporary, socially-acceptable products. This paper describes a comprehensive experimental study analysing several products made in Botswana and identifying the underlying socio-cultural factors that influenced their design. The study was conducted in collaboration with design students at the University of Botswana. Visual and textual data were collected. The results indicate that materials, emotional socio-cultural factors, and social practices have not yet been incorporated convincingly in contemporary product design. The paper proposes how designers can integrate socio-cultural factors by 'conscious design efforts' rather than by 'accident,' thereby leading to innovative, culturally-oriented and cherishable products with wider product acceptance. URI: http://hdl.handle.net/10311/614 Files in this item: 1
Moalosi_IJD_2007.pdf (344.7Kb) -
Moalosi, Richie; Popovic, Vesna; Hickling-Hudson, Anne (Creative Commons. www.ijdesign.org, August 1, 2007)[more][less]
Abstract: Products designed and manufactured in any country are influenced by local factors, such as the availability of raw materials, human skills, tradition, and socio-cultural values. The tendency to use available natural resources is in harmony with the eco-system. It is expected that culture plays a crucial role in designing contemporary, socially-acceptable products. This paper describes a comprehensive experimental study analysing several products made in Botswana and identifying the underlying socio-cultural factors that influenced their design. The study was conducted in collaboration with design students at the University of Botswana. Visual and textual data were collected. The results indicate that materials, emotional socio-cultural factors, and social practices have not yet been incorporated convincingly in contemporary product design. The paper proposes how designers can integrate socio-cultural factors by ‘conscious design efforts’ rather than by ‘accident,’ thereby leading to innovative, culturally-oriented and cherishable products with wider product acceptance. URI: http://hdl.handle.net/10311/404 Files in this item: 1
Moalosi_IJD_2007.pdf (1.437Mb)