Browsing Faculty of Engineering and Technology by Title
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Shuma-Iwisi, M.V. (University of Botswana, NaN, 1998)[more][less]
Abstract: One of the application areas of digital multiplexers is in implementation of logic equations. Truth tables can be used as a design tool, but they become very limited when design details are explored.It will be shown in this paper that the Karnaugh map (K-map) is an essential tool in the systematic detailed design of combinational circuits using multiplexers. The K-map will be used in two ways.First as a visual tool and secondly as a tool for decision making criteria. URI: http://hdl.handle.net/10311/619 Files in this item: 1
Suma-Iwisi_BJT_1998.pdf (1.304Mb) -
Muatjetjeja, B.; Chalique, C.M. (Elsevier http://www.sciencedirect.com/science?_ob=ArticleListURL&_method=list&_ArticleListID=1120288190&view=c&_acct=C000043160&_version=1&_urlVersion=0&_userid=778200&md5=2911144ac0b419d4936d24596384b313, NaN, 2009)[more][less]
Abstract: This paper aims to classify a generalized coupled Lane–Emden system and to compute the Noether operators corresponding to a Lagrangian for a generalized coupled Lane–Emden system which occurs in the modelling of several physical phenomena such as pattern formation, population evolution and chemical reactions. In addition the first integrals for the Lane–Emden system are constructed with respect to Noether operators. URI: http://hdl.handle.net/10311/416 Files in this item: 1
Muatjetjetja_CNSNS_2009.pdf (467.2Kb) -
Ketlogetswe, C. (Bentham Open http://www.bentham-open.org, January 1, 2009)[more][less]
Abstract: A number of photovoltaic pilot projects have been started in Botswana since 1990. The first photovoltaic project was Manyana PV project which started in 1992. The Japanese International Cooperation Agency (JICA) PV solar pilot project is the most recent PV solar project in Botswana, which was launched in 2003 at Kudumatse, Motlhabaneng, and Lorolwana villages. The primary objective of all these projects was to access the viability and sustainability of solar energy technology as an alternative source of energy especially for rural based communities. Depending on the findings, such projects were also intended to be replicated in other parts of the country. Despite all these efforts by the government of Botswana and donor agencies, the level of use of PV solar systems for power generation in Botswana, particularly in isolated communities, is very low. This paper, therefore, discusses the factors that impede the rapid development of photovoltaics power generation systems in the rural environment of Botswana. The study is focused on the photovoltaic power generation project which was carried out in three villages in Botswana, namely Kudumatse, Lorolwana and Motlhabaneng. URI: http://hdl.handle.net/10311/695 Files in this item: 1
Ketlogetswe_OREJ_2009.pdf (455.1Kb) -
Ketlogetswe, C.; Kemoeng, L.L.; Nato, L.T. (University of Botswana, www.ub.bw, NaN, 2004)[more][less]
Abstract: This paper describes a case study that evaluated the level of recycling operations in Botswana. Recycling operations are now recommended as effective waste management strategies for reducing the amount of municipal solid waste disposed at landfill. In assesing the level of recycling operations in Botswana, two companies which are effectively involved in the recycling operation were selected as the focus of the evaluation process. Then data from the two companies is complemented by the data collected from Gaborone landfill site. Finally the role of non-governmental organisations particularly environmental watch Botswana (somarelang Tikologo) is discussed. URI: http://hdl.handle.net/10311/822 Files in this item: 1
Ketlogetswe_BJT-2004.pdf (799.8Kb) -
Khalique, C.M.; Muatjetjeja, B. (Elsevier http://dx.doi.org/10.1016/j.amc.2009.01.008, NaN, 2009)[more][less]
Abstract: We carry out the Lie group classification of the generalized Lane–Emden equation xu00 þ nu0 þ xHðuÞ ¼ 0, which has many applications in mathematical physics and astrophysics. We show that the equation admits a three-dimensional equivalence Lie algebra. It is also shown that the principal Lie algebra, which in this case is trivial, has seven possible extensions. Three new cases arise for which the Lie point symmetry algebra is nontrivial. Comparison is then made of these cases with the Noether symmetry cases as well as the partial Noether operators. URI: http://hdl.handle.net/10311/415 Files in this item: 1
Khalique_AMC_2009.pdf (532.1Kb) -
Ganesan, C.T. (University of Botswana, NaN, 1999)[more][less]
Abstract: Water scarcity in arid and semi-arid countries such as Botswana; call for judicious planning and economic use. In this connection many water saving components and appliances have been devised. One such system for example is the partial flushing unit fitted to water closets, which cause the volume and flow of water in the drainage system decrease, compared with the ordinary systems. To maintain a sufficient transportation in drainage pipes connected to low flush water closets (water closets with a flow less than 6 litres per flush)it is necessary to follow a set of rules used in conventional systems. Author suggests that in countries like Botswana where availability of water is unpredictable only 4 litres per flush can be allowed for successful operations. In this paper certain rules for design and dimensioning drainage pipes for water saving systems are proposed. Besides the paper presents a complete general survey of the influence of branches and bends illustrated by means of drawings and descriptions. URI: http://hdl.handle.net/10311/618 Files in this item: 1
Ganesan_BJT_1999.pdf (1.079Mb) -
Ketlogetswe, C. (University of Botswana, NaN, 1998)[more][less]
Abstract: Since independence, the economy of Botswana has been undergoing a rapid transition from one in which the majority of the people depend on traditional agriculture and pastoralism to one in which formal sector employment predominates. This is partly reflected by rapid increase in vehicle population. Because of these changes,the country started to experience environmental problems. Unfortunately from the time of independence until late eighties, the level of environmental awareness in the country was very low, and therefore waste minimisation and reduction of environmental impact procedures were never in place.To date, many organizations in the country still seem not to be committed to reducing and disposing their wastes in environmentally friendly manner. The need to reconcile development with environmental concern, thus sustainable development, is vital. For the country to achieve that, an introduction of an environmental impact assessment in Botswana is essential, and thus, the main thrust of the current investigation is to determine the level of concern about environmental problems posed by waste engine oil in various organizations in the country. Management of various organizations were interviewed on their methods of waste of engine oil disposal. It was found that the disposal of waste engine oil by many organizations is resulting in serious environmental problems. URI: http://hdl.handle.net/10311/675 Files in this item: 1
Ketlogetswe_BJT_1998.pdf (1.028Mb) -
Ketlogetswe, C. (University of Botswana, Faculty of Engineering and Technology, http://ajol.info/index.php/bjt, April NaN, 1998)[more][less]
Abstract: Since independence, the economy of Botswana has been undergoing a rapid transition from one in which the majority of the people depend on traditional agriculture and pastoralism to one in which formal sector employment predominates. This is partly reflected by rapid increase in vehicle population. Because of these changes, the country started to experience environmental problems. Unfortunately from the time of independence until late eighties, the level of environmental awareness in the country was very low, and therefore waste minimisation and reduction of environmental impact procedures were never in place. To date, many organisations in the country still seem not to be committed to reducing and disposing their wastes in environmentally friendly manner. The need to reconcile development with environmental concern, thus sustainable development, is vital. For the country to achieve that, an introduction of environmental impact assessment in Botswana is essential, and thus, the main thrust of the current investigation is to determine the level of concern about environmental problems posed by waste engine oil in various organisations in the country. Management of various organisations were interviewed on their methods of waste engine oil disposal. It was found that the disposal of waste engine oil by many organizations is resulting in serious environmental problems. URI: http://hdl.handle.net/10311/659 Files in this item: 1
Ketlogetswe_BJT_1998.pdf (3.285Mb) -
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)