Browsing Faculty of Engineering and Technology by Issue Date
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Daka, J.S.J.; Isaac, J.S. (Science Publications http://www.doaj.org/doaj?func=abstract&id=116222, NaN, 2005)[more][less]
Abstract: This study proposes a technique of accessing applications from multiple file servers in a computer network that caters for a large user community. The technique is a step towards creating a computer network system that is simple to implement, scalable, easy to manage, transparent to the user and suitable for a university type environment. The proposed technique has some features of a distributed system, but is not as complex. It is built around a very popular commercial network operating system called Netware. URI: http://hdl.handle.net/10311/461 Files in this item: 1
Daka_JCS_2005.pdf (563.1Kb) -
McQuillan, J. (University of Chicago Press www.springerlink.com/index/K8T8573317636045.pdf, NaN, 2006)[more][less]
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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) -
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) -
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) -
Nedovic-Budic, Z.; Cavric, B. (Routledge, NaN, 2006)[more][less]
Abstract: With increasing internationalization of urban planning throughout the twentieth century and in the past several decades in particular, planning ideas and practices have been exported from a few, and imported in many countries. However, this ‘trade’ happens without clear expectations about the ensuing dynamics between the internal context and external influences. This paper attempts to enhance understanding of how planning systems evolve and which factors affect them. The conceptual frameworks and typologies used to characterize planning systems and their determinants are reviewed. Building on previous work, an integrated framework is proposed that captures the process, factors and outcomes of urban planning systems. The history of planning in Serbia and Montenegro is used to illustrate how a planning system evolves under changing circumstances and influences and to demonstrate the complexity of such process. The case study is not intended to provide a detailed historical account of the country’s planning trajectory, but to highlight the applicability of elements of the framework in a real setting. In particular, the focus is on conditions of imposition versus voluntary adoption of planning ideas as a way of examining the interaction between the local context and imported models, as well as the implications of such interaction. The article concludes with several pointers about the necessary research on the nature of planning exports and imports and their effects on the resultant urban systems, processes, environments and quality of life. URI: http://hdl.handle.net/10311/738 Files in this item: 1
cavric2006WAVES.pdf (4.557Mb) -
Litchev, A.I.; Yanev, K.M. (University of Botswana, NaN, 2006)[more][less]
Abstract: Analysis of the induction motor failures show, that a significant number of motors are damaged due to single phasing.At such conditions the current increases rapidly and the motor is subjected to burnouts and consequently to long downfalls in the corresponding industry.Normally all motors are protected against thermal overloading by bimetal relays, but they are not always capable to ensure protection at single phasing.A secure protection is needed to trip the motor off in any case of single phasing especially for high power motors. The problems related to the motor protection against single phasing are discussed in this paper paper and for ensuring of such protection an electronic circuit is proposed and described. The circuit reacts immediately whenever a motor line current gets zero.A signal from this circuit switches off the motor starter on failures of anyone of the three phases. In such way the motor burnouts and downfalls are prevented. URI: http://hdl.handle.net/10311/622 Files in this item: 1
Litchev_BJT_2006.pdf (1.753Mb) -
Chuma, J.M. (University of Botswana, NaN, 2006)[more][less]
Abstract: A dielectric loaded rectangular cavity for the design and realisation of different elliptic function filters topologies is presented. The 3-D Transmission Linee modelling method (TLM) is applied to the analysis of the cavity to obtain the resonant frequencies and couplings between the rectangular cavities. As an application to the analysis, a 4-pole elliptic function filter is designed and measured results presented. URI: http://hdl.handle.net/10311/701 Files in this item: 1
Chuma_BJT_2006.pdf (800.6Kb) -
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) -
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) -
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) -
Mosha, A.C. (United Nations Centre for Regional Development, http://www.uncrd.or.jp, NaN, 2007)[more][less]
Abstract: Botswana, with a population of nearly two million is a democratic, landlocked and prosperous country with one of the highest economic growth rates in the world with the bulk of its economy coming from minerals and cattle. Social and line infrastructure has reached most people in the country. This development has been brought about through careful national development planning as well as through sub national planning. Sub national planning, the subject of this paper, has been through the preparation of economic development plans (district development plans), spatial regional plans (district settlement strategic plans, regional plans and land use plans) and specific subject area plans. Through these plans, in which rural communities fully participate in their planning and implementation, the rural areas have seen marked change and natural resources have been carefully exploited for the benefit of all people. However, in spite of these achievements, their implementation has faced limitations, constraints and challenges which are difficult to overcome. The constraints relate to plan formulation, implementation and monitoring, administrative guidance and problems with vertical and horizontal communication that has created a gap between the intention and reality of bottom-up planning. The paper concludes by putting forward suggestions on how to overcome these problems and chart a way forward for rural development. URI: http://hdl.handle.net/10311/646 Files in this item: 1
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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) -
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) -
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) -
Loukanov, I.A.; Uziak, J. (Akademiai Kiado, NaN, 2007)[more][less]
Abstract: The effect of enamel-coating on the draught performance of an animal-drawn mouldboard plough was studied. A single furrow swing mouldboard plough-Maun Series, and the same type enamel-coated plough both ox-drawn, are compared under similar working conditions such as soil moisture content, depth and width of cut and approximately constant speed of ploughing. It was found that the enamel-coating reduces both the plough draught and the specific draught. The percentage reduction of the plough draught for enamel-coated plough compared to uncoated plough varied from 12.7% at 25% soil moisture content to 18.1% at 32% soil moisture content (dry basis). It was also found that the percentage reduction of the specific draught achieved with the enamel-coated plough in comparison with the uncoated plough varied from 20.3% at 32% soil moisture content to 25.7% at 25% soil moisture content (dry basis). URI: http://hdl.handle.net/10311/632 Files in this item: 1
Loukanov_PAES_2007.pdf (692.2Kb) -
Meyer, J.P. (Elsevier Science Ltd, http://www.elsevier.com/locate/apenergy, NaN, 2007)[more][less]
Abstract: The energy-utilization over a 10-year period (1994–2003) has been analysed for the South African industrial sector, which consumes more primary energy than any other sector of the economy. Four principal sub-sectors, namely iron and steel, chemical and petrochemical, mining and quarrying, and non-ferrous metals/non-metallic minerals were considered in this study. Primary-energy utilization data were used to calculate the weighted mean energy and exergy efficiencies for the sub-sectors and then overall values for the industrial sector were obtained. The results indicate that exergy efficiency is considerably lower than energy efficiency in all the sub-sectors, particularly in mining and quarrying processes, for which the values were approximately 83% and 16%, respectively. The performance of exergy utilization in the industrial sector can be improved by introducing various conservation strategies. Results from this study were compared with those for other countries. URI: http://hdl.handle.net/10311/668 Files in this item: 1
Oladiran_AE_2007.pdf (589.3Kb) -
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) -
Loukanov, I. A. (Research in Agricultural Engineering http://journals.uzpi.cz/web/RAE.htm, NaN, 2007)[more][less]
Abstract: This paper deals with the pumping process of a resonance-vibrating pump, which utilizes the resonance vibrations of one degree-of-freedom oscillating system. The pump is powered by a mechanical shaker consisting of two counter rotating offset masses and operating in resonance. The study investigates the nature of the pumping process and conditions required to achieve pumping action. Equations for the flow rate, pressure developed at ground level or any height above it, the pump efficiency, and the power delivered by the shaker are derived. The analysis of the pumping process revealed that the flow rate of the pump may be maximized either by increasing the acceleration imparted on the oscillating system, and/or by reducing the resonance frequency. It was found that the pressure developed by the pump is independent of the depth of pumping, provided that the same acceleration is imparted, and its efficiency may be increased either by reducing the resonance frequency and/or by increasing the depth of pumping. The preliminary test results about the flow rate and pressure developed at ground level appeared to be close to the values predicted by the proposed theory. Based on the analysis of the theoretical and experimental findings it is concluded that the equations derived in this study may be employed in designing resonance vibrating pumps for a desirable flow rate, pressure, and efficiency in pumping water from a specified depth. URI: http://hdl.handle.net/10311/693 Files in this item: 1
Loukanov_RAE_2007.pdf (792.9Kb) -
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)