Browsing Civil Engineering by Title
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Ngowi, A.B. (Elsevier, NaN, 1997)[more][less]
Abstract: The traditional developed earth as one of the most important construction materials by taking cognizance of the strength requirements, durability of resulting structures and the environmental concern in processing and using the material. Overthe years, however, modern earth construction has replaced the traditional methods. Unfortunately,these methods are also accompanied by high energy consumption and environmental degradation.This paper examines the methods of improving earth construction in two major villages in Botswana.Tests with different stabilizers showed that only certain proportions were effective and it was concluded that the traditional earth construction may be improved by using certain ratios of cement and lime as stabilizers. URI: http://hdl.handle.net/10311/606 Files in this item: 1
Ngowi_CBM_1997.pdf (968.2Kb) -
Malumbela, G.; Moyo, P.; Alexander, M. (Elsevier http://www.elsevier.com/locate/conbuiltmat, NaN, 2011)[more][less]
Abstract: Corrosion crack widths are often used by structural engineers in the field to predict level of steel corrosion as well as residual load-bearing capacities of corroding RC structures. This paper presents further work on this matter but with focus on corrosion crack patterns and how they affect rate of crack widening. It is based on results from a research where 17 quasi-full-scale (153 254 3000 mm) RC beams were corroded under various levels of sustained loads. The rate of widening of corrosion crack widths was found to be very much dependent on crack patterns. Deformation of cover concrete under each crack pattern was discussed. It was found that at maximum crack widths below 0.6 mm, the majority of beams exhibited nearly similar crack patterns as well as rate of widening of corrosion cracks. A mass loss of steel of 1% corresponded to a maximum crack width between 0.14 and 0.22 mm. At large crack widths (>0.6 mm), various beams exhibited very different rates of crack widening. It was shown that at crack widths above 0.6 mm, to be conservative an increase in mass loss of steel of 1% corresponded to corrosion crack widening of 0.02 mm. URI: http://hdl.handle.net/10311/676 Files in this item: 1
Malumbela1_CBM_2010.pdf (1.399Mb) -
Ssegawa, J.K.; Samman, J.; Kgatlegang, J. (University of Botswana, NaN, 2001)[more][less]
Abstract: Without cost information, project planning is difficult for clients just as pricing of tenders is difficult for construction firms. No agency or organization in Botswana has endeavoured to collect, compile and analyze construction data with a view to establish a cost/price database and a subsequent building index. This paper reports an investigation into the possibility of establishing a building index and a related cost database of building items. It is based on previous studies in Botswana, which indicated that no such information exists anywhere in the public domain and many firms have a tough time during the planning of projects and pricing of project tenders. By producing a price database of common building and a building index the study shows the possibility of establishing a fully-fledged data bank for both items. Recommendations are made on how to improve the current situation and the results of the study. URI: http://hdl.handle.net/10311/623 Files in this item: 1
Ssegawa_BJT_2001.pdf (2.314Mb) -
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) -
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) -
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) -
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) -
Raju, V.C.C. (University of Botswana, NaN, 1998)[more][less]
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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) -
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) -
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) -
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) -
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)