Masters Dissertations (FET)Masters dissertations approved by the Faculty of Engineering and Technologyhttp://hdl.handle.net/10311/14172024-03-28T21:12:16Z2024-03-28T21:12:16ZDesign and implementation of an automated irrigation control system for optimal water usage and enhanced agricultural productivityNcube, Innocenthttp://hdl.handle.net/10311/24522022-07-27T00:01:50Z2018-01-01T00:00:00ZDesign and implementation of an automated irrigation control system for optimal water usage and enhanced agricultural productivity
Ncube, Innocent
Irrigation of crops is essential for profitable crop production in most arid regions. The “million dollar” question is: when to water, and how much water is needed? The answer to this question lies in the development of innovative ways of irrigation control. In most irrigation installations in developing countries, the trend is to irrigate or to water the crop at the farmer’s hunch without relying on scientific data. They do not use accurate data logging systems that gather data about the condition of the crop. This traditional approach of irrigation results in too much or too little water being delivered to the crop resulting in crop stress and reduced yield. This document outlines the design, development and implementation of a ‘smart’ and innovative automatic irrigation control system with Internet capability. The system makes use of accurate scientific methods of finding out if plants need water. If plants are found to be in need of water, the controller automatically triggers the system to deliver the right amounts of water to the crop. The design employs the Internet of Things (IoT) applications to automatically connect and download weather data and weather-forecast information from the OpenWeatherMap Internet server. The OpenWeatherMap is a Meteorological services provider company which is situated in London in the United Kingdom. OpenWeatherMap collects, stores and automatically disseminates on request, weather data about any geographical location in the world over the Internet. Through the automatic irrigation control system, the farmer is able to receive weather updates and weather forecast information covering the next thirteen days. The received weather data comprises ambient temperature, barometric pressure, ambient humidity, wind speed, sunrise and sunset times. The automatic irrigation control system’s ability to combine data from agricultural sensors and weather forecast information available on the Internet allows for optimisation of irrigation activities, thereby saving water and improving crop yield. To cater for situations where there are internet outages, the system has an in-built mini-weather station which measures local ambient temperature, ambient humidity and barometric pressure. The Internet capability of the system also enables the manufacturer to easily render remote technical assistance to the farmer. The system allows the farmer to use a smartphone or a personal computer to remotely monitor system parameters and crop performance from anywhere in the world through the Internet. The prototype was subjected to several validation tests and the results suggest that the system may reduce irrigation water consumption by 26%. It was concluded that the smart automatic irrigation control system results in optimised water usage and increased crop yield.
A dissertation submitted to the Dept. of Electrical Engineering, Faculty of Engineering and Technology, University of Botswana in partial fulfillment of the requirement of the degree of Masters in Science (Electrical & Electronic Engineering). Citation: Ncube, I. (2018) Design and implementation of an automated irrigation control system for optimal water usage and enhanced agricultural productivity, University of Botswana.
2018-01-01T00:00:00ZThe effectiveness of management of lessons learned from Botswana Tourism Organisation (BTO) projectsChika, Patiencehttp://hdl.handle.net/10311/23752022-04-22T00:03:07Z2019-08-01T00:00:00ZThe effectiveness of management of lessons learned from Botswana Tourism Organisation (BTO) projects
Chika, Patience
Learning from past projects, be it to make the most of good practice or to avoid repetition of past mistakes, is one of the major success factors for continuous project accomplishment in organisations. Many researchers and project management practitioners underscore the need for organisations to effectively manage project learning, to ensure that organisations’ harvest lessons and apply them for the improvement of subsequent projects. That notwithstanding many organisations do not benefit from project learning, either because they do not have clear project learning processes in place, or the processes are not effectively implemented. Botswana Tourism Organisation (BTO) is one organisation that executes part of its mandate through the execution of construction projects in partnership with identified communities. This research embarked on assessing the effectiveness of the management of lessons learned by BTO for its construction projects. The research is a case study of five (5) projects that BTO has constructed since the organisation was established. The research was undertaken through a detailed review of the projects ‘documentation, distribution of questionnaires, follow-up interviews as well as focus group discussions with selected respondents. The results were analysed using various statistical, including rubric assessments, and non-statistical methods. The findings suggest that management of lessons learned for the projects is largely ineffective since some lessons learned processes i.e. capturing, storage and dissemination are minimally developed, while other processes i.e. analysis and infusion are virtually non-existent. Recommendations on key processes to be improved as well as key success factors for improvement have been put forth.
A dissertation submitted to the Dept. of Civil Engineering, Faculty of Engineering and Technology, University of Botswana in partial fulfillment of the requirement of the degree of Masters in Project Management. Citation: Chika, P. (2019) The effectiveness of management of lessons learned from Botswana Tourism Organisation (BTO) projects, University of Botswana.
2019-08-01T00:00:00ZExperimental and numerical evaluation of a solar dryer for drying banana (Musa spp)Mutabilwa, Philemon Xaveryhttp://hdl.handle.net/10311/20892021-05-12T00:00:55Z2019-10-01T00:00:00ZExperimental and numerical evaluation of a solar dryer for drying banana (Musa spp)
Mutabilwa, Philemon Xavery
A forced convection indirect type solar dryer having a double pass flat collector that can be used for drying bananas was designed, constructed and tested experimentally and numerically evaluated. The study mainly tried to address the problem associated with losses of bananas due to the average distance from neighboring countries to the market and the failure of market to consume the product within its shelf life. Hence, preservation method of bananas through solar drying technology was evaluated in this study so that to extend their shelf life.
The descriptions of the design methodology, development and operation of the newly constructed solar dryer are reported. The physical properties of banana fruits and relevant environmental factors of Botswana were considered in the development of the dryer. The dryer comprises of solar panel, flexible pipe, solar collector and drying chamber. The solar collector is made up of two glasses of 5 mm thickness and 1.6mm black painted aluminum absorber plate, all are enclosed in a casing made from plywood. The drying chamber is made from plywood with 20mm thickness. The dryer features a unique arrangement as the drying chamber is underneath the solar collector and the solar collector itself can be adjusted to an angle of 00 up to 350 at an interval of 50. The drying chamber is incorporated with a fan that sucks hot air from the collector on to the product for drying.
To investigate its performance, the solar collector was tested and achieved an optimal peak outlet temperature of 345K with a maximum efficiency of 72.5%, whereas the maximum useful heat gained by the solar collector from the solar radiation was 828.21W. The minimum and maximum ambient temperature, relative humidity and solar insolation recorded were 306.8K and 313K, 13.6% and 44.5% and 529 W/m2 and 983W/m2 respectively. Approximately 3.69kg of banana pulps sliced to a thickness of 3 to 5mm with moisture content of up to 82% dried within 8-13hrs to the final moisture content of >20%.
The geometry of the developed solar dryer was modeled using CFD software and 3D CFD simulations for the solar collector and drying chamber were performed using ANSYS 18.2. The fluid flow was characterized by RNG k-𝜀 turbulent viscous model and Discrete Transfer Radiation Model (DTRM) to allow radiation within the flow domain. A total number of 3,816,337 elements with nodes of 746,255 were generated in order to enhance smooth convergence of the simulation. The CFD results were compared with experimental results, and a good correlation was established between the two approaches particularly on airflow and the maximum temperatures of both the absorber plate and top glass. During the experiment, the maximum temperature of the absorber plate was 374K while that of CFD results was 384K. The maximum temperature reached on the top glass of the collector from the experimental result was 330K, while for CFD the result was approximately 325K-331K.
A dissertation submitted to the Dept. of Mechanical Engineering, Faculty of Engineering and Technology, University of Botswana in partial fulfilment of the requirement of the degree of Master of Science in Mechanical Engineering. Citation: Mutabilwa, P.X. (2019) Experimental and numerical evaluation of a solar dryer for drying banana, University of Botswana
2019-10-01T00:00:00ZEvaluating factors causing time and cost overruns in road projects in Roads department, BotswanaMokote, Palesahttp://hdl.handle.net/10311/20092020-03-18T00:01:32Z2016-01-01T00:00:00ZEvaluating factors causing time and cost overruns in road projects in Roads department, Botswana
Mokote, Palesa
Successful performance in a construction projects help to deliver a good product to the client. Poor time and cost performance on projects has become the key concern in Roads Department, Botswana. This is evidenced by records from some previous projects implemented between 1999 to 2013 which incurred time and cost overruns resulting in poor project delivery. This research has mainly been devoted to evaluating factors causing time
and cost overruns in the execution of the projects. Secondary data was obtained from the literature review which provided the researcher with time and cost factors to use in evaluating the situation in Roads Departments, Botswana. A structured questionnaire was given to 38 officers (15 comprising top management and project managers, 17 project officers and 6 officers in the project team) from Project Implementing Unit; Their responses were evaluated to establish the extend in which the factors were occurring as well as their severity, the higher
the occurrence, the more severe the factor. There were nineteen time factors and eleven cost factors identified, some from previous researches and some were brought up by the researcher. Non statistical analysis was used, which was the ranking of the factors on the frequency of their occurrence from respondents. Only those factors ranking 55% and above were found to be significant and severe. Statistical data analysis was applied using SPSS software package to determine the pattern of relationship on time and cost factors.
Techniques used were Exploratory Factor Analysis through the factor extraction technique, The Kaiser- meyer-Olkin & the Bartlett’s Test of Sphericity technique, Regression Coefficient, Analysis of Variance (ANOVA) and Pearson Correlation Coefficient. The findings depicted that six time factors and four cost factors were found significant and severe as they rated beyond 55%. It was again found out that there is a strong relationship between time and cost in achieving high or low project performance; four time factors were found most predictable to cost performance, while two cost factors were found most predictable factors to time performance. The mitigation measures have been given to ensure acceptable time and cost performance on project implementation. The study has given recommendations on the time and cost factors that were found severe and impacting projects negatively. These mitigations and the recommendations would assist the project team towards expected performance on output and delivery.
A dissertation submitted to the Dept. of Civil Engineering, Faculty of Engineering and Technology, University of Botswana in partial fulfillment of the requirements of the degree of Masters in Project Management. Citation: Mokote, P. (2016) Evaluating factors causing time and cost overruns in road projects in roads department, Botswana, University of Botswana
2016-01-01T00:00:00Z