Browsing Faculty of Engineering and Technology by Title
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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) -
Kiravu, C.S.A.M. (University of Botswana, NaN, 2000)[more][less]
Abstract: Computer models are used to replicate the essential performance features of a physical element using convenient modeling and simulation programs. Within SPICE, an acronym for the Simulation Program with Integrated-Circuit Emphasis, a model for the twin-depencence of the machine's open circuit generated e.m.f. on the time-independent flux and machine speed has not been investigated. This paper describes a steady state model of an open circuit DC shunt machine using PSPICE, the PC version of SPICE packaged within the OrCAD programming environment. The model is based on characterization of the generated e.m.f.as field current dependent polymial voltage source whose coeffecients are generated within MATHCAD by applying a linear regression fit on a set of experimental laboratory data points. The simulation results are displayed using the inbuilt graphic postprocessor within PSPICE called PROBE. This results show good replicative model validity within the laboratory range of exciting currents used in the simulative. URI: http://hdl.handle.net/10311/621 Files in this item: 1
Kiravu_BJT_2000.pdf (849.3Kb) -
Stephenson, D.; Kgomotso, A.K.; Matladi, T. (University of Botswana, NaN, 2006)[more][less]
Abstract: Water reservoir storage requirements are a function of demand and variation in inflow. The greater the variation the greater the storage required to meet a specified draft. The selected recurrence interval of failure also affects the storage required. It is found that the variation in flow increases the lower the average flow. Arid countries such as Botswana are therefore more vulnerable to drought than low mean annual flows would indicate. Rainfall and river flow records for Botswana were analyzed to produce maps that show the coefficients of variation (COV's) over the country.Examples of the use of the charts are given.The COV of river flow is significantly higher than for rainfall. This means that it is theoritically more economic to harvest rain than to attempt to store river flow. There is also less evaporation from rain tanks owing to the smaller surface area to depth ratio. However, the scale of storage also affects economics and rain harvesting affects catchment water balance. URI: http://hdl.handle.net/10311/625 Files in this item: 1
Stephenson_BJT_2006.pdf (1.089Mb) -
Gizejowski, M.A.; Barszcz, A.M.; Branicki, C.J.; Uzoegbo, H.C. (Elsevier http://www.linkinghub.elsevier.com/retrieve/pii/S0143974X05001057, NaN, 2006)[more][less]
Abstract: Three groups of methods for the inelastic analysis of steel plane frames with semi-rigid joints are considered in this paper. The first one consists of simplified second-order (or P–Δ) plastic-hinge methods for the determination of member internal forces in semi-continuous frames subjected to moderate sway deformations. For these methods, a set of notional loads to simulate second-order effects in the first-order plastic-hinge analysis is used. The second group of methods presented in the paper refers to the general second-order methods of analysis. These methods are based on the concept of a refined plastic hinge in the form of a two-surface degradation model or a spring-in-series model. Refined plastic-hinge methods allow the simulation of the combined effect of gradual joint-stiffness degradation, and distributed plasticity along the member length as well as across the member sections. Finally, the third group consists of more general advanced analysis methods. They are based on second-order refined plastic-hinge methods of analysis in which the effects of residual stresses and geometric imperfections of individual members are accounted for in the global analysis. This type of analysis has recently become more important, since modern design codes (e.g. Eurocode 3: part 1.1) now require the structural engineer to address more rigorously instability problems of real structural systems. An illustrative example is presented. Conclusions are drawn regarding methods of analysis currently used in the design of sway frames, and their future development. URI: http://hdl.handle.net/10311/417 Files in this item: 1
Gizejowski_JCSR_2006.pdf (1.547Mb) -
Matshediso, I.B. (Elsevier http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6VBM-4HMXJJS-1-1&_cdi=5930&_user=778200&_orig=search&_coverDate=09%2F30%2F2005&_sk=999699996&view=c&wchp=dGLbVlz-zSkWb&md5=2b0e6a95538c49f439dba7e43fe1ee22&ie=/sdarticle.pdf, NaN, 2005)[more][less]
Abstract: Botswana’s mineral policy objective is primarily to maximize the national economic benefit from the development of mineral resources. In 1999, the government replaced the old mining code of 1977, which was out of tune with prevailing economic philosophies with a new mining code. Although, the old act had its shortcomings it served the country reasonably well for 20 years, during which time the country was transformed from being one of the poorest of the world’s poor to a middle income country. One of the cornerstones of the new and old mining codes is that government does not subscribe to privately owned minerals rights. The Botswana government attempts to provide a fair balance between the various stakeholders. There are, however, areas in the mineral policy and mining codes that need to be critically reviewed as outlined in this paper. URI: http://hdl.handle.net/10311/377 Files in this item: 1
Matshediso_RP_2005.pdf (616.8Kb) -
Matshediso, I.B. (University of Botswana, http://www.ub.bw, NaN, 2004)[more][less]
Abstract: Although most SADC countries have or were in the process of liberalizing their legislation and fiscal regimes some member states seemed to levy exorbitant tax rates. SADC members’ states need to note that in designing the optimum tax regime for their respective countries a balance will have to be struck between all the role-players including the investor, government and the community. It is imperative that the tax regimes are designed to provide stability over time and are transparent, easy to administer and internationally competitive. Mining investors view taxation systems as a cost of doing business in a particular country. The effects of taxes can influence company decisions. It is therefore of paramount importance for SADC governments to design tax regimes which will allow the mining sector to get a return on investments which is commensurate with the capital outlay and risk. It is equally important that the mining business should play a key role to the socio-economic developments of the host country in terms of job markets, secondary industries, hospital, schools, skills development and education. The taxation level in SADC countries should be both comparable and competitive with other countries with similar geological potential and this is currently not the case. Chile offered investors the best fiscal regime when compared to the twelve selected SADC countries. URI: http://hdl.handle.net/10311/1107 Files in this item: 1
Matshediso_BJT_2004.pdf (1.076Mb) -
Ngowi, A.B. (Elsevier Ltd; http://www.elsevier.com/wps/find/journaldescription.cws_home/296/description#description, NaN, 2007)[more][less]
Abstract: The ensuing globalization of the construction industry as well as the highly fragmented and divisive nature of the industry are among the forces that are influencing it to seek management approaches such as strategic alliances that could leverage the capabilities of the various participants. This paper reports on a study that investigated the factors considered by firms when selecting alliance partners, and the influence of trustworthiness in deciding the governance structures of the alliances. A study of key partners in existing and potential construction alliances in Botswana that was carried out using a postal questionnaire and structured interviews determined that firms consider complementarity, similar status, indirect prior alliance experience and reputation before they make a selection of an alliance partner. The study also determined that partner trustworthiness eliminates the need of contractual clauses in the operation of the alliances. The paper concludes that trustworthiness of a partner is an influencing factor in all stages of the alliance development. URI: http://hdl.handle.net/10311/260 Files in this item: 2
license.txt (1.998Kb) -
Ngowi, A.B. (Elsevier Ltd; www.elsevier.com/locate/buildenv, May 4, 2006)[more][less]
Abstract: The ensuing globalization of the construction industry as well as the highly fragmented and divisive nature of the industry are among the forces that are influencing it to seek management approaches such as strategic alliances that could leverage the capabilities of the various participants. This paper reports on a study that investigated the factors considered by firms when selecting alliance partners, and the influence of trustworthiness in deciding the governance structures of the alliances. A study of key partners in existing and potential construction alliances in Botswana that was carried out using a postal questionnaire and structured interviews determined that firms consider complementarity, similar status, indirect prior alliance experience and reputation before they make a selection of an alliance partner. The study also determined that partner trustworthiness eliminates the need of contractual clauses in the operation of the alliances. The paper concludes that trustworthiness of a partner is an influencing factor in all stages of the alliance development. URI: http://hdl.handle.net/10311/171 Files in this item: 2
license.txt (1.998Kb)ngowi2.pdf (118.4Kb) -
Aghdasi, F.; Bhasin, A. (University of Botswana, NaN, 2004)[more][less]
Abstract: Asynchronous sequential circuits offer improved speed of operation when compared to their synchronous counterparts. However, the standard methods of asynchronous design require careful examination of the flow table for possible critical races and hazards. This complicates the design procedure and often leads to extra states and additional hardware. A number of new design methodologies which involve locally generating a clock and using it to self synchronize the machine have been proposed. Such clock signals are generated wherever an input changes, or by controlled excitation whenever a change of inputs necessitates a change of state. All such designs, where the circuit is timed by locally generated clocks, are called Self-Clocked Sequential Circuits. This paper uses a design methodology for the State variable toggling through data driven clocks to implement a Direct Memory Access Controller (DMAC) as a design example. The design is simulated on software and also implemented using discrete hardware components. The methodology can be extended to parallel controllers for neutral networks and automated using state assignment techniques already for synchronous parallel controllers. URI: http://hdl.handle.net/10311/648 Files in this item: 1
Aghdasi_BJT_2004.pdf (1.145Mb) -
Ketlogetswe, C.; Fiszdon, J.K.; Seabe, O.O. (Elsevier Science Ltd. www.elsevier.com/locate/rser, NaN, 2007)[more][less]
Abstract: Import of a huge proportion of electrical energy from the Southern African Power Pool, and the geographical location and population distribution of Botswana stimulated the need to consider renewable energy as an alternative to imported power. The paper describes a systematic experimental study on a mini-solar chimney system. Particular attention is given to measurements of air velocity, temperature and solar radiation. The results for the selected 5 and 6 clear days of October and November, respectively, are presented. These results enable the relationship between average insolation, temperature difference and velocity for selected clear days to be discussed. URI: http://hdl.handle.net/10311/271 Files in this item: 1
Ketlogetswe_RSER12_2008.pdf (1.195Mb) -
Ketlogetswe, C.; Mothudi, T.H. (Elsevier Science Ltd. http://www.elsevier.com/locate/rser, NaN, 2009)[more][less]
Abstract: Lack of access to electricity grid form the main challenge facing majority of developing regions particularly in rural communities. The situation is driven mostly by the absence of electricity infrastructure in most of the developing countries particularly in rural communities. A number of developing countries are now encouraging the use of solar home systems in isolated areas. Botswana is not immune to this trend. Consequently, available evidence puts the overall contribution of solar energy to primary energy supply in Botswana to less than 1%. A plethora of factors are responsible for inhibiting rapid development of solar home systems in isolated areas in Botswana. Some major impediments often cited as causing low use of solar home systems by rural communities in Botswana include, among others, the following: (i) Low-income status of most rural inhabitants. (ii) Migration of house-owners from village status to lands, or cattle posts. This paper, therefore, analyses factors that impede the rapid development of photovoltaics power generation systems in rural environments in Botswana. The analysis is based on photovoltaic power generation pilot project which was carried out in three (3) villages in Botswana, namely Kudumatse, Lorolwana and Motlhabaneng. URI: http://hdl.handle.net/10311/327 Files in this item: 1
Ketlogetswe_RSER_2009.pdf (1.107Mb)