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Domestic use of electrical energy from wind energy in Botswana

Dimitrova, J.; Slivkov, G. (University of Botswana, Faculty of Engineering and Technology, http://ajol.info/index.php/bjt, April NaN, 1998)

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Abstract:

This paper presents an examination of the possibility of using wind turbines generating electricity for households in the remote rural areas of Botswana. On the basis of theoretical consideration of the wind system generating electricity, and the power demands of a typical Botswana rural household, some types of possible advanced systems are recommended. Comparative information is given about the costs of solar (photovoltatic) and wind power systems. From an analysis of the magnitude and the distribution of the wind in Botswana, conclusions are made about the areas where the wind system for electricity generation could be used during the whole or part of the year.

URI:

http://hdl.handle.net/10311/664

Files in this item: 1

Dimitrova_BJT_1998.pdf (2.728Mb)

Draught requirements of enamel coated animal drawn mouldboard plough

Loukanov, I. A.; Uziak, J.; Michalek, J. (Czech Academy of Agricultural Sciences http://agriculturejournals.cz/web/RAE.htm, NaN, 2005)

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Abstract:

The power requirement of tillage implements is an important design consideration particularly for animal-drawn implements where the power is limited. The paper presents the possibility of reduction in the draught requirements of animal-drawn mouldboard plough by using enamel coating on the soil-engaged components such as the mouldboard, share and the landside. Trials were conducted to compare enamel-coated Maun Series single mouldboard plough (manufactured by Zimplow Limited, Bulawayo, Zimbabwe) with similar uncoated plough, both animal-drawn, under comparable working conditions. Experiments were done at 25% and 32% d.b. soil moisture content on a red clay soil in Zimbabwe. The parameters measured in evaluating the draught performance of both ploughs were the tractive effort(pull),speed of ploughing,depth and width of ploughing,and soil conditions(i.e.soil moisture content,soil bulk density and soil penetration resistance). It was found that for similar working conditions the enamel coating reduced the specific draught by 20 to 26% depending upon soil moisture content.

URI:

http://hdl.handle.net/10311/705

Files in this item: 1

Uziak_RAE_2005.pdf (504.4Kb)

Energy and exergy analyses of energy consumptions in the industrial sector in South Africa

Oladiran, M.T.; Meyer, J.P. (Elsevier http://www.elsevier.com, NaN, 2007)

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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/10311/957

Files in this item: 1

Oladiran_AP_2007.pdf (792.0Kb)

Energy and exergy analyses of energy consumptions in the industrial sector in South Africa

Meyer, J.P. (Elsevier Science Ltd, http://www.elsevier.com/locate/apenergy, NaN, 2007)

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Abstract:

URI:

http://hdl.handle.net/10311/668

Files in this item: 1

Oladiran_AE_2007.pdf (589.3Kb)

Energy applications in Botswana

Oladiran, M.T. (Elsevier Science Ltd, http://www.elsevier.com/wps/find/journaldescription.cws_home/269/description#description, NaN, 1995)

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Abstract:	Botswana depends heavily on imported petroleum products for all premium applications. However, there is an abundant reserve of coal and other alternative sources of energy. This paper presents the energy trends and the various options for harnessing the resources. The importance of energy conservation is also discussed.
URI:	http://hdl.handle.net/10311/670

Files in this item: 1

Oladiran_ECM_1995.pdf (958.6Kb)

Energy losses in a ram press machine for vegetable oil expression

Uziak, J.; Loukanov, I. A. (Dalhousie University, NaN, 2009)

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URI: http://hdl.handle.net/10311/617

Files in this item: 1

Uziak_CANCAM_2009.pdf (664.5Kb)

Engineering education in Botswana

Foster, J. D. G. (Tempus Publications http://www.ijee.ie/, NaN, 2002)

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Abstract:

The economy of Botswana has grown rapidly since it became independent in 1966, but the population is only 1.7 million. Engineering construction projects are of large scale. The University of Botswana offers engineering degrees in four disciplines, under programs that cover ten semesters. The particular challenges to engineering education in Botswana, as well as the structure of the present and future University of Botswana programs, are described in this paper. Emphasis is placed on a wide range of student individual investigation and design work, and the benefits of a particular project to the student and the program are stated in an illustration.

URI:

http://hdl.handle.net/10311/704

Files in this item: 1

Uziak_IJEE_2002.pdf (769.0Kb)

A fourier method of determining the speed fluctuation coefficient of a general slideer-crank mechanism

Uziak, J.; Foster, J.D.G. (University of Botswana, Faculty of Engineering and Technology, http://ajol.info/index.php/bjt, October NaN, 2001)

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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)

A fourier method of determining the speed fluctuation coefficient of a general slider-crank mechanism

Uziak, J.; Foster, J.D.G. (University of Botswana, NaN, 2001)

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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)

Fundamentals of coal gasification technology and its relevance to Botswana coal industry

Khartchenko, N.V.; Oladiran, M.T.; Douglass, G.W. (University of Botswana, http://www.ub.bw, NaN, 1999)

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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)

Introduction to general education courses to engineering programmes at the University of Botswana

Uziak, J.; Oladiran, M. T. (Tempus Publications http://www.ijee.ie/, NaN, 2009)

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Abstract:

Complementary studies are fundamental for accreditation of engineering programmes in line with the Washington Accord. This paper presents the experiences of the University of Botswana in introducing General Education Courses (GECs) for the purpose of broadening the educational experience of all students, with particular reference to engineering students. Students registration data captured in the Integrated Tertiary Software (ITS) were analysed using Excel software. The five-year study period was from 2002 to 2007. Results indicate that engineering students mainly took GECs offered by the science and technology disciplines. It is concluded that GECs should be retained within the engineering programmes but the student advisory system should be improved and skills (e.g. IT competencies) that are important for professional development should be embedded in core courses instead of in general education.

URI:

http://hdl.handle.net/10311/700

Files in this item: 1

Uziak_IJEE2_2009.pdf (886.3Kb)

Investigating the pumping process of a resonance-vibrating pump for medium-depth boreholes

Loukanov, I. A. (Research in Agricultural Engineering http://journals.uzpi.cz/web/RAE.htm, NaN, 2007)

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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)

The level of recycling operations in Botswana

Ketlogetswe, C.; Kemoeng, L.L.; Nato, L.T. (University of Botswana, www.ub.bw, NaN, 2004)

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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)

Management of waste oil in Botswana and the possibilities of energy recovery from waste oil

Ketlogetswe, C. (University of Botswana, NaN, 1998)

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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)

Management of waste oil in Botswana and the possibilities of energy recovery from waste oil

Ketlogetswe, C. (University of Botswana, Faculty of Engineering and Technology, http://ajol.info/index.php/bjt, April NaN, 1998)

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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)

Mean global radiation captured by inclined collectors at various surface azimuth angles in Nigeria

Oladiran, M.T. (Elsevier Science Ltd, http://www.elsevier.com/wps/find/journaldescription.cws_home/405891/description#description, NaN, 1995)

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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)

Measurement of operating forces in a ram press crushing sunflower seed

Foster, J.D.G.; Uziak, J.; Loukanov, I.A. (Blackwell Publishing Ltd, http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1475-1305, NaN, 2009)

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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)

Modelling and simulation of an air motor system using extended radial basis algorithm

Marumo, R.; Tokhi, M.O. (University of Botswana, Faculty of Engineering and Technology, http://ajol.info/index.php/bjt, April NaN, 2007)

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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)

A new and innovative look at anti-insulation behaviour in building energy consumption

Masoso, O.T. (Elsevier http://www.linkinghub.elsevier.com/retrieve/pii/S0378778808000923, NaN, 2008)

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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)

Oxide of nitrogen in diesel engines: formation, effects and control

Inambao, F.L.; Mosweu, M. (University of Botswana, NaN, 2001)

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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)

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