Browsing Faculty of Engineering and Technology by Title
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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) -
Ganesan, C.T. (University of Botswana, http://www.ub.bw, NaN, 1998)[more][less]
Abstract: This paper is the outcome of students'project guided by the author. An attempt has been made to design and develop a solar still for rose production in India. This unit has the following features:i) possibility of tilt adjustments to suit different altitudes of sun,ii) specially designed steep basin for conveniently keeping the rose petals and water in an inclined position and iii)cover which can be opened to facilitate the cleaning operations. This unit supplied 3.7 litres of rose water in three days during winter in Madras, in India. The sunshine and solar radiation particulars of Botswana are shown to indicate that a better climatic conditions prevail here for a higher production rate. URI: http://hdl.handle.net/10311/684 Files in this item: 1
Gaesan_bJT_1998.pdf (2.287Mb) -
Ganesan, C.T. (University of Botswana, NaN, 1998)[more][less]
Abstract: This paper is the outcome of students'project work guided by the author. An attempt has been made to design and develop a solar still for rose water production in India. This unit has the following features:i) possibility of tilt adjustments to suit the different altitudes of sun,ii)specially designed stepped basin for conveniently keeping the rose petals and water in an inclined position and iii)cover which can be opened to facilitate the cleaning operations.This unit supplied 3.7litres of rose water in three days during winter in Madras, in India. The sunshine and solar radiation particulars of Botswana are shown to indicate that a better climatic conditions prevail here for a higher production rate. URI: http://hdl.handle.net/10311/640 Files in this item: 1
Ganesan_BJT_1998.pdf (345.3Kb) -
Oladiran, M.T.; Pheko, H. (Elsevier Science Ltd, http://journals.elsevier.com/00014575/accident-analysis-and-prevention/, NaN, 1995)[more][less]
Abstract: In many African countries, including Botswana, the driving schools and instruction given to pupils are uncontrolled. Thus, this paper presents the results of an investigation into the level of professional training offered by the driving schools in Gaborone. A total of 400 randomly selected drivers completed questionnaires on their training, accident records, and L-tests. Male trainee drivers received more instruction than females, and there was some indication that the pass rate on L-tests was lower for female drivers. Also, the pickup van forms the majority of the national vehicle population. It accounts for almost 40% of the accidents but is presently not used for training in the commercial driving schools. It is concluded that the quality of professional instruction in driving schools needs improvement so that learners can be encouraged to take training from these institutes. URI: http://hdl.handle.net/10311/669 Files in this item: 1
Oladiran_AAP_1995.pdf (1.673Mb) -
Kanyarusoke, K.E.; Uziak, J. (Wiley Periodicals Inc. http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1099-0542, NaN, 2009)[more][less]
Abstract: Formal Engineering Education has traditionally been delivered using the low technology—high touch lecturing method, in which the lecturer and student meet face to face. Distance education in this field has been quite slow to develop primarily because of difficulty in delivery of practical based instructions and problems on integrity of assessments. Developments in information technology and the increased demand for further education by people already in employment have however changed this even in developing countries. It puts extra demand on Lecturers to guide distance learners in handling numerical computations so prevalent in Engineering. At the campuses, computer based methods are available in the high touch—high tech lecture method. High level and efficient computer software is used to help the student to simulate and solve some problems. However, such software is expensive—and therefore—not readily available to the distant learner. Spreadsheets on the other hand are almost universal on today’s computers and they bridge the gap between hand calculations and high level programme computations. This paper therefore makes a case for the use of spreadsheets in Distance Engineering Education. An example in Spring Design, Selection and Adaptation is used to illustrate the simplification and other advantages of their use by practicing distance learners. URI: http://hdl.handle.net/10311/603 Files in this item: 1
Kanyarusoke_CAEE_2009.pdf (1.031Mb) -
Moalosi, R.; Popovic, V.; Hickling-Hudson, A. (Design Education Forum of South Africa (DEFSA), http://www.defsa.org.za, January 1, 2007)[more][less]
Abstract: There is little in-depth research that can assist designers to use culture as a catalyst for designing innovative products within Botswana’s context. This is supported by evidence from the literature which indicate that from an African perspective, there is no solid theoretical framework which can assist designers to consciously integrate users culture in designing products. This challenges designers to gain a deeper understanding of users culture and find strategies on how they can use culture as a resource in product development. The concept of culture and design are intertwined, thus modification in the former evolution both reflect and determine developments in the latter. For example, design changes culture and at the same time is shaped by it. The paper discusses an experimental design study conducted at the University of Botswana. Participants were challenged to transform a set of socio-cultural factors and encode them into recognised product design features that reflect Botswana's culture. The data generated by participants was analysed using the qualitative content analysis methodology. The paper concludes by discussing a culture-oriented design model which has shown one way on how to consciously specify, analyse and integrate socio-cultural factors in the early stages of the design process. The design model challenges the way products are designed for different cultures and supports the use of local content in solving design problems. URI: http://hdl.handle.net/10311/597 Files in this item: 1
Moalosi_DEFSA_2007.pdf (1.151Mb) -
Moalosi, R.; Popovic, V.; Hickling-Hudson, A.R. (Design Education Forum of South Africa (DEFSA) http://www.defsa.org.za, NaN, 2007)[more][less]
Abstract: There is little in-depth research that can assist designers to use culture as a catalyst for designing innovative products within Botswana’s context. This is supported by evidence from the literature which indicate that from an African perspective, there is no solid theoretical framework which can assist designers to consciously integrate users culture in designing products. This challenges designers to gain a deeper understanding of users culture and find strategies on how they can use culture as a resource in product development. The concept of culture and design are intertwined, thus modification in the former evolution both reflect and determine developments in the latter. For example, design changes culture and at the same time is shaped by it. The paper discusses an experimental design study conducted at the University of Botswana. Participants were challenged to transform a set of socio-cultural factors and encode them into recognised product design features that reflect Botswana’s culture. The data generated by participants was analysed using the qualitative content analysis methodology. The paper concludes by discussing a culture-oriented design model which has shown one way on how to consciously specify, analyse and integrate socio-cultural factors in the early stages of the design process. The design model challenges the way products are designed for different cultures and supports the use of local content in solving design problems. URI: http://hdl.handle.net/10311/579 Files in this item: 1
Moalosi_DEFSA_2007.pdf (1.151Mb) -
Bolaane, B. (University of Botswana, NaN, 2006)[more][less]
Abstract: Public support for source separation schemes in developing countries is still subject to continuing debate and limited work has been directed at understanding its manifestations. The purpose of this survey was to assess existing and potential levels of household participation in waste source separation as well as establishing the role they could play in future source separation schemes in Gaborone. Questionnaire based surveys were used to elicity information from households about their awareness of recycling and recycling initiatives, attitudes and willingness to participate in source separation schemes. The survey involved 17 households who participated in a pilot source separation scheme and 284 households who did not. The results showed that the majority of households are aware of recycling and recycling initiatives, but this awareness does not necessarily translate into participation in recycling activities in the absence of incentives and visible systems. It was also found that the majority of households are willing to participate in future source separation schemes, however, such willingness was primarily limited to separating materials that at the time had known available markets and were easy to separate. URI: http://hdl.handle.net/10311/678 Files in this item: 1
Bolaane_BJT_2006.pdf (3.020Mb) -
Ntshwene, K.; Kashiwagi, J.; Kashiwagi, D. (Royal Institute of Chartered Surveyors http://www.rics.org fileID=4956&fileExtension=PDF, NaN, 2009)[more][less]
Abstract: The Project Management Section at the University of Botswana has been undergoing a test to transform the section from an education based faculty to a research based faculty. The test was initiated by a Fulbright Scholar (FS) from the Performance Based Studies Research Group (PBSRG), bringing a new research model, a new risk management (RM)/project management (PM) model, and a concept of a research based graduate education that had been very successful at PBSRG. They proposed increasing the level of research activity of the UB PM section by merging the graduate MPM program and the industry research effort. They proposed using a research based graduate program, treating the graduate students from industry as a resource instead of a student, and their organizations as a potential testing laboratory. The mechanism to make the effort a success is the very powerful technology of the Performance Information Procurement System (PIPS) and the deductive logic of the Information Measurement Theory (IMT). This paper captures the case study results and future potential of the concept, highlighting the operational model to sustain the research platform in an underdeveloped country in a resource starved environment. URI: http://hdl.handle.net/10311/477 Files in this item: 1
Ntshwene.RICSCOBRA_2009.pdf (1.199Mb) -
Loukanov, I. A.; Uziak, J. (International Symposium on Theory of Machines and Mechanisms (IFToMM), NaN, 2001)[more][less]
Abstract: The single-stroke ram press machine is widely used for sunflower oil extraction in African countries. It is manually operated, low speed machine constructed on the basis of slider-crank mechanism. The paper presents a detailed theoritical analysis of the mechanism of the linkage system. The analysis is done for different positions of the driving lever (handle) nad other parameters, which influence the performance of the machine. Based on that analysis conclusions on the optimal performance of the mechanism are drawn. URI: http://hdl.handle.net/10311/667 Files in this item: 1
Loukanov_IFToMM_2001.pdf (993.1Kb) -
Oladiran, M.T. (Elsevier Science Ltd, http://www.elsevier.com/wps/find/journaldescription.cws_home/405891/description#description, NaN, 1994)[more][less]
Abstract: Solar energy is finding wide application via several energy-saving devices and systems. Its use, especially in rural areas, can often be limited by the non-availability of complete information on insolation data. In this investigation, both the mean extraterrestrial and terrestrial radiations were calculated for three zones in Nigeria. These zones were assumed to be dependent mainly on the latitude, L. The isotropic model was employed for the computation of the diffuse and ground reflected components of radiation. Consequently, the total insolation was obtained for various inclinations of the collector surface. It was found that three solar energy seasons exist for each zone. For maximum total incident radiation, a different collector inclination is ideal for each solar energy season. However, for all year round applications, a fixed inclination varying between L and (L+10) degrees is recommended. URI: http://hdl.handle.net/10311/672 Files in this item: 1
Oladiran_AE_1994.pdf (1.391Mb)