Browsing Faculty of Engineering and Technology by Title
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Sahu, B.K.; Jayaram, S. (University of Botswana, NaN, 2000)[more][less]
Abstract: Alarmingly high accumulation of fly ash has led geochemical engineers into finding a solution for the use of flyash as a construction material in the recent past. As of now, although the material has been used in a limited way in the construction of roads, embarkments,dykes and by cement industries, most of it is still dumped as a waste material. There is a general opinion mongst teh Geochemical engineers that fly ash is a non-hazardous material. However, the authors felt that it may not be entirely true due to the fact that fly ash does contain quite a significant proportion of soluble salts. These salts would leak into water if fly ash comes into contact with water or if the ground water leaked through a bed of fly ash. The investigation revealed that Dissolved Oxygen of fly ash polluted tap and clean water is reduced to a level far below the permissible limit for aquatic life. The author would like to emphasise that the findings of the present investigation are being submitted to open an agenda on the issue of water pollution by the fly ash leachate, may it be ground water, water in the vicinity of the ash being used in the construction of dykes,dams, river training structures or for reclamation on sea shores. URI: http://hdl.handle.net/10311/601 Files in this item: 1
Sahu_BJT_2000.pdf (863.8Kb) -
Daka, J.S.J. (University of Botswana, NaN, 1998)[more][less]
Abstract: There are many instances where a telephone call charge needs to be avaialable immediately after a call is made. Usually, for a fee a telecommunication provider can provide call charge for a particular call. Call charging systems provide this information automatically without recourse to a telecommunications service provider. The application of call charging systems include private automatic branch exchange line cards, home telephone bill monitoring, monitoring telephones in a telephone cafe booth or payphones. This paper examines the design of hardware and software of the sub-systems for a subscriber based call charging system. URI: http://hdl.handle.net/10311/616 Files in this item: 1
Daka_BJT_1998.pdf (1.141Mb) -
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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Ssegawa, J.K.; Masambaji, C.N. (Faculty of Engineering and Technology, University of Botswana, www.ub.bw, April NaN, 2011)[more][less]
Abstract: To deliver project effectively is of paramount importance because most of the world population depend on services delivered by projects. Reports from various countries around the world, including Botswana, still indicate poor project delivery. Several causes may be advanced including ineffective project control. Devising means to alleviate the control problem is therefore, of great importance. Scholars and practitioners have suggested various techniques that monitor and keep track of projects. One of them is the earned value analysis(EVA) which touted by many as an efficient yet effective control system because of its ability to control scope, cost and time. Based on this premise, the study reported in this paper investigated possible use of EVA in building projects in Botswana. The investigation was two fold, firstly, through a questionnaire, quantity surveyors (QSs) were requested to indicate whether they have use the EVA on any building project in Botswana. Results from this survey indicated that EVA is not used at all in Botswana. In fact, majority (63%) of the QSs have not heard of the system before. The second phase of the study investigated its possible use, that is, if using EVA is more adventageous than the convectional control method (CCM). Results indicated that EVA system provide quality information that was well structured, more objective, and easily accessible to all key stakeholders in a timely and understandable manner. However, to use EVA system several challenges were also indentified which included firstly, the need to train the key players in the EVA technique.; the need to change the project regime from arms-length to a cooperative on to allow transfer and sharing of information in the design and construction phases of a project; increasing the use of IT; completing design before tendering even for other trades; and nominating sub-contractors as soon as the main contract is appointed. URI: http://hdl.handle.net/10311/875 Files in this item: 1
Ssegawa_BJT_2011.pdf (2.489Mb) -
Kanyeto, O.J. (University of Botswana, NaN, 1999)[more][less]
Abstract: Advantages of using Finite Element Method (FEM)in structural engineering practice are presented in this paper.A brief description of the method is given with the aim to illustrate the rich solid mathematical basis that makes its foundation.The paper then presents some guidelines on how to build a good model for Finite Element Analysis (FEA) purposes. The guideline emphasises the need for the analyst to have a clear understanding of the physical problem and of the behaviour of the elements he employs to carry out the analysis.A practical example presented in order to illustrate the type of analysis and results that can be obtained from a commercial FE software package. This example forms part of the research work that was carried out by the author.And finally, it is recommended that all practicing structural engineers must learn the basics of finite element method, and be equiped with some FE software packagess. Since it is the most commonly used and trusted method in the world of engineering today. In order to keep up with the rest of the world in engineering advancements, the author finds it vital to equip all engineers with the latest engineering software packages and to elevate continuing engineering education. URI: http://hdl.handle.net/10311/681 Files in this item: 1
kanyeto_BJT_1999.pdf (1.860Mb) -
Uziak, J.; Foster, J.D.G. (University of Botswana, Faculty of Engineering and Technology, http://ajol.info/index.php/bjt, October NaN, 2001)[more][less]
Abstract: In this paper a method is presented which enables the solution of the equation of motion of the slider-crank mechanism. Expansion of functions into Fourier series is used in this method, whereby the solution of the equation of motion is also obtained in the form of Fourier series. This method enables also the determination of the coefficient of speed fluctuation of the slider-crank mechanism. The method creates the basis for an analysis of the influence of various factors, e.g. the working conditions or the construction parameters of the system, on the coefficient of speed fluctuation. URI: http://hdl.handle.net/10311/665 Files in this item: 1
Uziak_BJT_2001.pdf (2.257Mb) -
Uziak, J.; Foster, J.D.G. (University of Botswana, NaN, 2001)[more][less]
Abstract: In this paper a method is presented which enables the solution of the equation of motion of the slider-crank mechanism. Expansion of functions into Fourier series is used in this method, whereby the solution of the equation is also Fourier series. This method enables also the determination of the coefficient of speed fluctuation of the slider-crank mechanism. The methods create the basis for an analysis of the influence of various factors, e.g. the working conditions or the construction parameters of the system, on the coefficient of speed fluctuation. URI: http://hdl.handle.net/10311/702 Files in this item: 1
Uziak_BJT_2001.pdf (999.6Kb) -
Khartchenko, N.V.; Oladiran, M.T.; Douglass, G.W. (University of Botswana, http://www.ub.bw, NaN, 1999)[more][less]
Abstract: Coal is plentiful in many parts of the world but its combustion can create severe environmental and aesthetic problems.In the past three decades, the cost of crude oil and natural gas has been unstable and the reserves of these fuels are exhaustible. Other non-conventional energy resources, for example, solar, wind and tidal energy are only making a small contribution to the energy mix in few countries. Consequently, coal still has an important role to play to satisfy the energy demand, especially when it can be converted before combustion to other less environmentally objectionable forms, e.g. coal gas/producer gas. This paper describes the basic principles of coal gasification process and compares the performance of different gasifiers. The fundamentals of the raw gas cleaning methods are presented and experience to date of coal gasification in Botswana is discussed.It seems certain that coal gasification in tanderm with combined cycle power plant will be a principal technique for electricity generation in the next century. The paper recommends that Botswana takes necessary actions to gain maximum advantage from these developments. URI: http://hdl.handle.net/10311/710 Files in this item: 1
Khartchenko_BJT_1999.pdf (1.810Mb) -
McQuillan, J. (University of Chicago Press www.springerlink.com/index/K8T8573317636045.pdf, NaN, 2006)[more][less]
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Mbewe, D.D. (University of Botswana, NaN, 1998)[more][less]
Abstract: This paper describes the fundamental principles of production and accomplishment of High Definition Television (HDTV)-the television system of the future.It looks at the parameters of high definition television (HDTV),and shows how the values of these parameters can be derived from consideration of the performance of the viewer's visual system. Bandwidth requirements for various TV and HDTV systems are compared, and a number of optical fibre transmission techniques are considered for HDTV. In conclusion it is stated that the large bandwidths demands of uncompressed HDTV can be met by emerging technology in optical fibre transmission systems-in particular, wavelength division multiplexing (WDM). The paper is as a result of a project study conducted by the author and a colleage when he studied for his degree at Essex University,England. It makes no reference to the development and relevance of HDTV in the African context. URI: http://hdl.handle.net/10311/627 Files in this item: 1
Mbewe_bjt_1998.pdf (1.386Mb) -
Ngowi, A.B. (Taylor and Francis, http://www.pdfserve.informaworld.com/940578_73138570, NaN, 1997)[more][less]
Abstract: This paper examines the strategy of employing a hybrid combination of indigenous and modern housing construction technologies. Using a Botswana village as a case study, this paper examines four traditional house types in relation to the household income, skills, materials and aspects which could be improved by adapting industrialized methods. Using experimental houses, the case study provides the costs, benefits, potential problems and implementation considerations. The paper discusses the weaknesses and virtues of traditional construction technologies, how appropriate aspects from modern technologies can be incorporated or adapted into traditional methods and the implications for developing appropriate, affordable housing technologies URI: http://hdl.handle.net/10311/370 Files in this item: 1
Ngowi_1997_BRI.pdf (800.7Kb) -
Ngowi, A.B. (MCB University Press, http://www.emerald-library.com, NaN, 2000)[more][less]
Abstract: Total quality management (TQM) as an integrated approach to management that represents a holistic management philosophy, rather than a series of techniques, is embedded with cultural values and assumptions that are consistent with its culture of origin. This study aims to determine the outcome of implementing TQM in a place that does not share its cultural base. A survey of 100 construction firms in Botswana found that, although the values embedded in TQM could be adopted within the organisations into which it is implemented, the cultural context of the greater society resisted some of the values. It was concluded that, for TQM to be successful in a particular cultural setting, it has to take on some of the host cultural values URI: http://hdl.handle.net/10311/350 Files in this item: 1
Ngowi_2000_JEIM.pdf (915.4Kb) -
Ngowi, A.B. (MCB University Press; Emerald Publishing Group Ltd; http://www.mcbup.com/research_registers/quality.asp, NaN, 2000)[more][less]
Abstract: Total quality management (TQM) as an integrated approach to management that represents a holistic management philosophy, rather than a series of techniques, is embedded with cultural values and assumptions that are consistent with its culture of origin. This study aims to determine the outcome of implementing TQM in a place that does not share its cultural base. A survey of 100 construction firms in Botswana found that, although the values embedded in TQM could be adopted within the organisations into which it is implemented, the cultural context of the greater society resisted some of the values. It was concluded that, for TQM to be successful in a particular cultural setting, it has to take on some of the host cultural values. URI: http://hdl.handle.net/10311/170 Files in this item: 2
license.txt (1.998Kb)ngowi1.pdf (97.37Kb) -
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) -
Uys, P.; Kiravu, C.; Mothibi, J. (Emerald http://www.emeraldinsight.com, NaN, 2004)[more][less]
Abstract: This paper reports on the process of developing a blended online engineering course at the Faculty of Engineering and Technology of the University of Botswana. It presents the actual development process in terms of its management, the University's preferred pedagogical approach to student-centred learning and the consequent technological choices and deployment. In that regard, the paper will demonstrate the development of the Electrical principles course (EEB211) focusing attention on what was done, how and what result was achieved. This paper will be a useful reference for all those staff expected to develop their online courses alongside their normal face-to-face lectures. URI: http://hdl.handle.net/10311/460 Files in this item: 1
Uys_CWIS_2004.pdf (702.2Kb) -
Litchev, A.I.; Yanev, K.M. (University of Botswana, NaN, 1999)[more][less]
Abstract: Electromagnets are essentials for the operation of relays, contactors and other electromagnetic apparatus and take part in driving control and protective circuits of industrial processes and power systems. Performance of each electromagnet affects the driving time and the stability of operation of such circuits. This paper examines the improvement of the performance of AC electromagnets by using two diodes. The theoritical analysis lead to expressions for calculating the maximum, average and minimum values of coil-currents. Due to the electromagnetic processes in the coil, the current becomes pulsating but unidirectional and better force-gap characteristics are achieved. Consideration are made for reduction of the mass ferromagnetic and copper materials in the electromagnets and for decreasing teh responding time. URI: http://hdl.handle.net/10311/683 Files in this item: 1
Litchev_BJT_1999.pdf (924.8Kb) -
Sahu, B.K.; Mathur, S.; Kemsley, B. (University of Botswana, NaN, 2004)[more][less]
Abstract: The national road network continues to play a fundamental and catalytic role in the promotion of social and economic development of Botswana. However, a combination of adverse climatic and geological factors, such as scarcity of conventional road building materials, near absence of a non saline surface water, and climatic extremes have dictated the need for innovative engineering approaches to highway design, construction and maintenance. In recent years application of fly ash has been considered in road construction with great interest. Fly ash is a pozzolanic material, which in the presence of water combines with lime to produce a cementetious material with excellent structural properties. Attempts have, therefore, been made at Botswana Roads Department in collaboration with University of Botswana to explore the feasibility of utilizing fly ash alone to improve the physical and strength characteristics of locally available non-standard marginal materials. The results indicate that with the addition of fly ash plasticity dereases while California Bearing Ration (CBR) increases for calcrete and other locally available marginal materials for road construction. With appropriate amount of fly ash and an adequate curing the material can be improved to meet the requirement of base and sub-base coarse. URI: http://hdl.handle.net/10311/644 Files in this item: 1
Sahu_BJT_2004.pdf (606.5Kb) -
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) -
Daka, J.S.J. (http://ijedict.dec.uwi.edu/viewarticle.php?id=555., NaN, 2008)[more][less]
Abstract: In August 2002, the University of Botswana changed from a yearlong to a semester based academic system. However, the progression regulations were not be fully implemented on the information system mainly due to problems of interpretation. Due to this, a manual system was used. The manual system could not cope in making recommendations for all students leading to some regulations not being applied. To address this, a revision of the regulations was undertaken in 2007. These regulations require implementation on the information system. This paper discusses the main aspects of the 2007 regulations and their implementation via a computer program. The paper shows that a complete implementation of the regulations is possible using a computer program. The program was applied to sample students' academic results to provide progression recommendations that were found to agree with expected results. The paper concludes that an information system based implementation ensures uniform application of regulations. URI: http://hdl.handle.net/10311/470 Files in this item: 1
DAka_IJEDICT_2008.pdf (154.8Kb)