Masters Degree Dissertations

Permanent URI for this collectionhttp://localhost:4000/handle/20.500.12504/84

Browse

Now showing 1 - 20 of 80

Assessing occupational safety and health hazards at workplaces in Uganda : a case of four engineering materials testing laboratories
(Kyambogo University (Unpublished work), 2024-06) Lusundo, Fred Moses
Workplaces in Uganda are mandated to satisfy the requirements of the Occupational Safety and Health Act (OSHA), 2006 regarding the Occupational Safety and Health of workers. Despite of the above, many workplaces in Uganda including Engineering Materials Testing Laboratories have continued not to satisfy the above requirements. Although different strategies to manage OSH risks have been devised and several entities like Safety committees and Ministry of Gender Labour and Social development (MoGLSD) empowered by the act to ensure compliance of work places, OSH in engineering materials testing laboratories has remained a challenge; thereby exposing staff and visitors to the laboratories to serious OSH hazards including physical injuries and long-term health risks like cancer. It is these compliance gaps that this study is set to examine, using the case of Engineering Materials Laboratory (EML), Central Materials Laboratory (CML), Geotechnical Foundation Services Ltd (GFS) and Geotechnical Engineering and Technology Laboratory Ltd (GET). The study used both quantitative and qualitative research designs. Quantitative data collection was supported by the use of questionnaires with closed ended questions administered to 60 respondents and then qualitative data, by use of an interview guide. The study findings indicate that for all laboratories, risks due to chemical hazards ranked highest, followed by risks due to accident hazards. Risks due to physical hazards ranked third for EML as opposed to risks due to ergonomics and psychosocial factors that ranked third for CML, GFS and GET. Risks due to ergonomics and psycho-social factors ranked lowest for EML as opposed to risks due to physical hazards factors that ranked lowest for CML, GFS and GET. Consequently, the assessment of the level of compliance to Uganda’s OSH regulatory framework indicated that GET, GFS, EML and CML were 88%, 83.4%, 79.7% and 76% compliant respectively, implying that there are still gaps in the implementation of OSHA, 2006. In conclusion, the study attributes these gaps to inadequate financial resources allocated for OSH operations and laxity in implementing OSH management strategies by the various key players among others.
Assessing occupational safety and health hazards at workplaces in Uganda : a case of four engineering materials testing laboratories
(Kyambogo University (Unpublished work), 2024-07) Lusundo, Moses Fred
Workplaces in Uganda are mandated to satisfy the requirements of the Occupational Safety and Health Act (OSHA), 2006 regarding the Occupational Safety and Health of workers. Despite of the above, many workplaces in Uganda including Engineering Materials Testing Laboratories have continued not to satisfy the above requirements. Although different strategies to manage OSH risks have been devised and several entities like Safety committees and Ministry of Gender Labour and Social OSH in engineering materials testing laboratories has remained a challenge; thereby exposing staff and visitors to the laboratories to serious OSH hazards including physical injuries and long-term health risks like cancer. It is these compliance gaps that this study is set to examine, using the case of Engineering Materials Laboratory EML), Central Materials Laboratory (CML), Geotechnical Foundation Services Ltd (GFS) and Geotechnical Engineering and Technology Laboratory Ltd (GET). The study used both quantitative and qualitative research designs. Quantitative data collection was supported by the use of questionnaires with closed ended questions administered to 60 respondents and then qualitative data, by use of an interview guide. The study findings indicate that for all laboratories, risks due to chemical hazards ranked highest, followed by risks due to accident hazards. Risks due to physical hazards ranked third for EML as opposed to risks due to ergonomics and psychosocial factors that ranked third for CML, GFS and GET. Risks due to ergonomics and social factors ranked lowest for EML as opposed to risks due to physical hazards factors that ranked lowest for CML, GFS and GET. Consequently, the assessment of the level of compliance to Uganda’s OSH regulatory framework indicated that GET, GFS, EML and CML were 88%, 83.4%, 79.7% and 76% compliant respectively, implying that there are still gaps in the implementation of OSHA, 2006. In conclusion, the study attributes these gaps to inadequate financial resources allocated for OSH operations and laxity in implementing OSH management strategies by the various key players among others.
Mutagenic potential of selected industrial effluents and their effects on germination, growth and yield parameters of cowpeas (Vigna Unguiculata L)
(Kyambogo University (Unpublished work), 2024-11) Aliobe, Caku Semi
Increasing industrialization in the developing world especially Uganda has been inevitable leading to build up of industrial effluents. The Industrial effluent composition varies depending on activity in the manufacturing process at a specific time. These industrial effluents possess temporal toxicity of unknown magnitude due to the chemical reactions that take place and this has possible mutagenic risk to the ecosystem. The study assessed the mutagenic potential of selected industrial effluents in Kinawataka Area, Kampala Uganda and their effects on germination, growth and yield parameters of Cowpeas (Vigna unguiculata L). The selected industrial effluents were assessed for mutagenicity using Ame’s test, the effluents were then used to intoxicate the seeds of cowpeas and thereafter, the germination, growth and yield parameters were determined on the plants in randomised experimental design. The industrial effluent from the plastic and mattress industry had the highest mutagenic potential with undiluted effluent having 32.0 (1.41) and 27.0 (1.14) revartants respectively. Aluminium products industry had the lowest mutagenicity with 12 (1.41) revartants. Regarding the germination and seedling parameters, the undiluted effluent from mattress industry caused the highest reduction in germination rate by 50 %, shoot length by 75 %, root length by 55 % and wet weight by 47 % of the seedling. The dry weight of the seedling was reduced by 22 % by effluent from pharmaceutical industry. The 25 % dilution plastic industry effluent increased shoot significantly by 38 %. The undiluted mattress effluent registered a significant reduction effect on growth and yield parameters as follows; root nodules by 26 %, number of seeds per pod by 28 % and dry weight of seeds by 18 %. The paint effluent also significantly reduced number of root nodule per plant and dry weight of seeds at dilutions of 75 % and above. Aluminium waste also registered significant effect on number of root nodules per plant and number of seeds per plant. The other effluents had no significant effect on growth and yield parameters of cowpeas at p ≤ 5 %. It was therefore established that all the industrial effluent assessed were mutagenic with varying potential. These observations were due to the fact that industrial effluents contain toxicants with varying chemicals that interact to cause such mutagenic effects, such as propylene oxide in mattress effluent which interfere with the DNA bases in order of Guanine > Adenine > Cytosine > Thymine. The government should therefore, increase surveillance of industrial effluents so as to enhance compliance and protect the environment.
Development and evaluation of a sustainable solar cooker for operations in Uganda
(Kyambogo University (Unpublished work), 2024-10) Sebunya, Steven
The high level of increasing technological advancements and human population globally have resulted into escalated energy demands. With cooking accounting for almost 90% of all the household energy consumption in developing countries, traditional firewood stoves and improved charcoal stove are still dominant regardless of their negative impact. In Uganda, there is need of adopting clean and renewable non-depleting alternative energy sources among which includes solar cooking technologies. Many regional areas across Uganda and especially in the Northern and Eastern, receive approximately 4–5 kWh/m² per day of solar energy which is commendable for most solar cooking technologies. This study deals with the development and evaluation of a novel box-type direct solar cooker while putting in to consideration the existing cooking dynamics, solar irradiation and locally available materials for operation in Ugandan. For optimization, the cooking energy requirements for common foods like rice, matoke, and cassava, along with the average solar irradiation in Uganda, were considered to determine the cooker’s aperture area, which was calculated to be 0.1897 m². The cooker was further developed with internal side-wall reflectors to improve its performance efficiency and these were calculated as 340, 560, 430, and 430 due to south, north, west, and east respectively. Solar data and geographical data for Mbarara city (Having the lowest amount of daily Global Horizontal Irradiation (GHI) among the selected regional areas) were considered in the module design and simulation for performance feasibility. Using COMSOL Multiphysics 5.5 software, thermal analysis and optical analysis were conducted for the systems performance validation. Finally, locally available materials were considered for costing and construction of the developed solar for both economic and manufacturing feasibility. The cooker was costed at 210 USD with a payback period of 1 and 1.3 years while transitioning from cooking using charcoal and electricity respectively.
Introducing value based maintenance management to satisfy buildings’ stakeholders in Uganda : a case study of prisons in Lango sub region
(Kyambogo University (Unpublished work), 2024-03) Ochen, Ceasor
A maintenance service is successful if the end users of a building are satisfied with the maintained building. However, the state of the prisons’ buildings in Uganda doesn’t satisfy the prisons’ staff. Therefore, this study explored the use of value-based maintenance management in order to develop a maintenance framework for assessing prisons’ stakeholder’s satisfaction. Questionnaire surveys and key informants interviews were used to collect data which were quantitatively and qualitatively analysed respectively to deduce inferences. Quantitative analysis was done by relative importance index and multi regression analysis whereas qualitative analysis was done by content analysis. Study findings revealed that, among the prisons buildings; maintenance of inmates wards yielded the highest stakeholders’ satisfaction. For every element of inmates wards addressed at planning, design and construction stages of maintenance, stakeholders’ satisfaction increased by 0.448, 0.360 and 0.568 respectively. Whereas considering conditioned based maintenance at design and construction stages of maintenance yielded the highest stakeholders’ satisfaction, with increases in satisfaction of 0.583 and 0.468 respectively for every element of conditioned based maintenance considered. As regards risk factors, stakeholders’ participation was the most important risk factor; for every improvement in participation by stakeholders at planning, design and construction stages of maintenance, stakeholders’ satisfaction increased by 0.619, 0.623 and 0.666 respectively. Therefore, the key components of a maintenance framework for assessing prisons’ stakeholders’ satisfaction are; prioritising maintaining inmates’ wards, developing designs and construction methods after assessing the condition of the wards for fitness for purpose and full participation of all the prisons’ stakeholders at all stages of maintenance.
Investigating the cost of mechanized unpaved road maintenance operations in Uganda
(Kyambogo University (Unpublished work), 2024-06) Obeti, Moses Andrew
Force Account Mechanism (FAM) is the predominant road maintenance system in Uganda’s local government setting and also in some private sector plantation agriculture setups. With previous research citing challenges in cost management and efficiency of the FAM method, it becomes paramount to analyse how FAM is implemented in both the private sector and government led operations alongside proposing possible solutions to these challenges. This research offered to analyse unpaved road maintenance cost factors alongside providing a cost model solution to improve on cost prediction of the FAM system. Gulu District Local Government (DLG) and Kakira Sugar Limited (KSL) were selected as case study areas. Cost data from the Uganda National Roads Authority (UNRA) was chosen for cost comparison purposes. Two descriptive research methods were used: observations and case study approach. The selected case study areas were accessible and reachable in terms of data collection. Control parameters affecting unpaved mechanized road maintenance were identified as, machine repair costs, maintenance costs, machine depreciation costs, worker’s salaries, machine insurance costs, and machine fuel costs. The study recommends the need for an effective electronic cost database system for unpaved road maintenance works with emphasis on mechanized road maintenance cost driver analytics and management, alongside improvement in aspects of maintenance processes. Further research can be conducted on equipment condition level prediction and analytics at the DLG.
Analysing the factors affecting the performance of local construction companies in Uganda
(Kyambogo University (Unpublished work), 2024-07) Mutekanga, Zadock
Even though the local construction business is rapidly growing, poor performance has hurt the industry's reputation, therefore the study analyzed the factors affecting the performance of local construction companies, specifically looking at challenges faced, characteristics of local construction companies and establishing ways of improving their performance. Data was gathered using a cross-sectional study design that combined qualitative and quantitative methods with semi-structured questionnaires and interview guides. The study's target sample was 132 heads of departments and directors, however only 119 of them responded (a response rate of 90.2% for the questionnaire and 85.7% for the interviews). The respondents were selected by purposive and stratified random sampling. The data was presented and analyzed using percentages, frequencies, tables, and charts. The relative importance index (RII) was used to rate the difficulties experienced by local construction enterprises, their characteristics, and the steps taken to increase their productivity and competitiveness. The findings showed that the primary difficulties faced by local construction enterprises are insufficient funding and restricted capability, inadequate skilled man power, high interest rates, political and donor directives and limited advanced technology. Some characteristics of local construction companies are; being too many and small in size, labour intensive techniques and that has led to low quality output of the projects, abandoned projects, time and cost overruns. The measures to improve the performance of local construction companies majorly are continuous benchmarking, aligning national and international standards, merging and pooling resources together as well as further training in advanced technology. The study therefore, recommended that local construction companies need to pool resources together in order to have sufficient working capital, foster the development of workforce skills through instruction in cutting-edge and sophisticated technology.
A framework to mitigate impacts of contract termination on construction projects in Uganda
(Kyambogo University (Unpublished work), 2024-04) Mafabi, Micheal
Construction projects in Uganda are faced with a challenge of resorting to termination of contract as a remedy for contract breach by either party to contract. The study aimed developing a frame work to mitigate impacts of construction contract termination on projects. Fifty-eight causes and twenty impacts of construction contract termination were identified through detailed literature review, questionnaire surveys and interviews administered to all key stakeholder categories in the industry who included: project beneficiaries, clients, contractors and consultants. The study categorized the causes of contract termination into five: contractor-related; client-related; financial and business environment-related; project-related; and, political-related causes. Thereafter, the impacts of contract termination on stake holder were analyzed using relative importance index (RII). The computed RII for each of the causes and impacts was used to rank them. Findings from the study revealed that contractor- related causes with RII=0.760 ranked the most critical among the five categories. The most significant causes of contract termination were revealed to be abandonment of work, client’s bankruptcy, delays in completion of works, contractor bankruptcy or insolvency, and, lack of resources. The most significant impacts of contract termination were identified as loss of income to the contractor, loss of reputation, delays in project completion, abandonment of project, cost overruns. The study concluded that contract termination is inevitable in the construction industry but can be prevented when the causes are properly identified, analyzed and managed during the project life cycle. A framework to mitigate contract termination in the construction industry was developed as a solution otherwise the adverse effects would continue occurring. The study recommended proper planning and provision of affordable credit facilities as mitigation measures.
Examining factors affecting effective force account implementation in Uganda district local governments
(Kyambogo University (Unpublished work), 2024-08) Lukungu, Hussein
This study examined the implementation of the force account mechanism (FAM) in ten Uganda District Local Governments (UDLGs). The study was instigated by a policy shift in June 2012, where the government transitioned from using contractors to FAM to achieve SDG 9 on building resilient infrastructure. The study objectives were; to examine the current practices of force account implementation in UDLGs, to determine the impact of current practices in implementation of Force Account in UDLGs, to examine the challenges of current practices in implementation of force account in UDLGs and to develop an effective force account implementation tool for construction projects in UDLGs. The descriptive research design with quantitative and qualitative research methods was employed. The study focused on the ten lowest-performing road fund-funded districts in Uganda, selected based on performance constraints and data availability. Data was collected from 57 participants who play various roles within these districts. Questionnaire data was analyzed with SPSS version 20 and content analysis for interviews for this study. The findings of the study unveiled strong support for the utilization of force account methods (FAM) in emergency work, particularly supported with force account practices of preparation expenditure and implementation schedule, procurement and annual work plan had high relative importance index where risk of work interruptions was effectively managed by the procuring entity or public authority. The budget, work supervision, and adherence to supervisor instructions attracted significant support. Challenges emerged were limited resource availability, incompetent personnel, suitability of equipment, and additional work during project implementation. Nonetheless, respondents expressed adherence to regulations, effective monitoring and supervision of project. Correlation results indicated that current force account practices were significant. Yet, regression results indicated that preparation of expenditure schedule (βeta = 0.518), implementation schedule (βeta = 0.489), procurement annual plan (βeta = 0.509) have significant effect on implementation of force account mechanism, unlike annual work plan which was insignificant. Compliance to regulatory framework, monitoring and supervision supported with increased budget and competent personnel enhanced implementation of force account mechanism (FAM). It was concluded that preparation of expenditure, implementation schedule and procurement annual plan supported by regulatory policy, budget and competent personnel enhanced implementation of FAM as displayed by the research established framework. The study recommended that preparation, approval, verification of expenditure and implementation schedule as well as annual procurement plan aligned with the budget supported with availability of qualified personnel, monitoring and evaluation, compliance to regulations enhanced project completion using force account implementation and it was upon this that a maintenance force account implementation frame work for the UDLGs was established.
Quantitative assessment of non-revenue water prevalence in Nyarwodho GFS in Uganda
(Kyambogo University (Unpublished work), 2024-11) Ocen, Charles
Studies that were conducted reported on impacts of Non-Revenue Water (NRW) on the sustainability of piped water supply systems. Millennium development goal No.7 (MDG 7) and sustainable development goal No. 6 (SDG 6) are among the many strategies adopted globally to ensure access to safe water by the global population and particularly developing countries including Africa. However, water utilities across nations have their efforts hampered by Non-Revenue Water prevalence. Narwodho GFS is a gravity flow system that abstract water from the river Namrwodho at the border between DRC and Nebbi District, and a convenctional treatment facility with 4000m3/day treatment capacity before transporting to the 9 supply zones in Nebbi and Pakwach Districts. The system is experiencing high NRW prevalence which affects service delivery. An investigation was conducted to assess and quantify NRW prevalence in the scheme in order to understand the causes of NRW hence develop mitigating strategies. Field surveys were conducted to evaluate the real situation hence develop strategies for mitigation. Billing data were obtained from the records of scheme operator while water production records were obtained from the treatment plant superintendent. Pipes were inspected to understand their characteristics including the pressure ratings and the trenching depths and their contribution to NRW prevalence in the scheme, Hydraulic modeling and analysis was conducted to understand the pipe flow behavior in contributing to NRW, and amongst the software’s used were; AutoCAD Civil 3, EpaCAD, and EPANET 2.2 for data manipulations and analysis. The employees of the scheme and water users were interviewed in order to understand the impacts of NRW on them. The findings revealed that the NRW trend in Nyarwodho GFS were; 2018 (93.36%), 2019 (80.25%), 2020 (77.79%) and 2021 (75.34%) contrary to the 39% reported by the scheme through Utility Performance Monitoring information system (UPMIS) portal, with an 18% NRW reduction was recorded in a period of four years. Pipe bursts on the transmission pipeline was observed to have contributed the most to NRW in the scheme, and this was particularly exuberated by; over supply at night, installation of low pressure rating uPVC pipes in some sections, and shallow trenching that has been made even shallower by soil erosion amongst others. Users reported intermittent supply where they spend days or weeks without water, while the scheme staffs have low remunerations due to low revenue collections. Mitigation measures were recommended to water utility providers which among others include but not limited to; regulating night supply, financial support to the utility, adopting preventive measures, good asset management, timely supply of repair materials, replacing pipes of low pressure ratings, staff capacity building, motivation of employees, rewards for reporting vandalism, regular user sensitization and engagements, involvement of local leadership and users in the affairs of water supply, and creating customer what sup group for reporting breakdowns.
Evaluation of the factors influencing performance of building construction projects in Uganda : a case study of Masaka city
(Kyambogo University (Unpublished work), 2024-08) Hakizimana, Venust
In Uganda, over twelve percent (12%) of the gross domestic product (GDP) is contributed by building construction sector and is of great significance in current economy. Despite this contribution to the sector, building construction fail due to performance issues and limited research exists on the major factors contributing to this trend resulting in project delays and potential compromises in project quality. Finding ways to make building construction projects in Ugandan cities more effective was the aim of this study. a case study on the city of Masaka. Using the Krejcie and Morgan table for sample size determination, a sample of 201 respondents were chosen from the population of 420 participants in the study, which used a survey research design. A set of interview guidelines and a questionnaire were used to gather data. Excel and SPSS version 21 were utilized for the data analysis. Cost considerations, health and safety factors, time factors, productivity factors, quality factors, project stakeholders' factors, environmental factors, and resource variables were all identified. The findings of the regression analysis showed that the time factors (RII 0.751), quality factors (RII 0.717), and cost factors (RII 0.706) had a substantial influence on the performance of building construction projects in Masaka city. To enhance the performance of building construction projects, a framework was developed based on time, quality, and cost variables (factors with major influence). These findings highlight the need to prioritize these factors with significant impact when evaluating and managing building construction projects in Masaka City.
Comparative analysis of force account mechanism and contracting in implementation of road projects in central Uganda
(Kyambogo University (Unpublished work), 2024-10) Gamubaka, Fred Cedric
A well-maintained road network is critical to the transformation of a country’s economic development. This study compared the unit costs for implementing road improvements in Uganda using the force account mechanism versus contracting. Both quantitative and qualitative research designs were used in the study. The use of questionnaires with closed-ended questions helped collect quantitative data, and interview guides helped collect qualitative data. Stata (V13) was used to analyze the primary data that were gathered from the field, while Excel spreadsheets were used to analyze the secondary data. The findings on the influences for effective implementation of force account mechanism on implementation of road projects found that the cost per unit of the road was the most important, followed by employee skills, the availability of road equipment, and human resource costs. The study also found that the biggest barriers to the effective implementation of FAM were a lack of equipment, accountability for funds, and insufficient funding for road upgrades. The findings further, on comparison of the Unit cost for FAM and Contracting revealed that the unit cost incurred under contracting was five times higher than that incurred under force account mechanism. While on the strategies, the most significant strategy was adherence to public procurement laws followed by establishment of a supervision committee. In conclusion, FAM has saved the implementation costs of road projects in local governments though it still faces challenges most especially funding and equipment that the government has to solve. The study recommends that the government doubles the funding for implementation, buy enough equipment for districts, outfit the areas without workshops, evaluate the procedures for routine manual maintenance, conduct personnel training, and raise worker pay.
Assessment of moisture related defects in masonry walls
(Kyambogo University (Unpublished work), 2024-04) Elem, Joel
Moisture intrusion into walls continues to be one of the top challenges in the building construction industry in Uganda. The study assessed and investigated moisture related defects in masonry walls, materials and construction methods to mitigate moisture rise and related defects in masonry. This study made an assessment on moisture related defects in masonry walls, together with; carrying out a baseline survey on the building industry practice to find the cement to sand mix commonly used, and to assess prevalence of capillary water rise in buildings, determining the height of water rise by capillarity in masonry walls from damp proof course level, and finding out the materials and construction methods that can be used to mitigate moisture rise and related defects in masonry walls, as the specific objectives. Experimental masonry wall models measuring; 1.6m wide x 1.9m height x 230mm thick for the study. The models were built of ordinary clay bricks, well plastered and built with cement sand mortar / plaster of mix ratios; 1:1, 1:2, 1:3, & 1:4. Selected vertical points on the wall surface were cored and tested for moisture content. It was found that the masonry walls were susceptible to moisture rise, and it was also observed that; the stronger the mortar mix, the less the capillary rise of moisture in the wall. The height of water / dampness is highest at the bottom, just above the damp proof course levels, and moisture rise ranged between 0 – 0.6m above dpc levels. The study further investigated the efficiency of various water proofing materials that can be applied on the external walls to minimise capillary rise. The percentage reduction in moisture content was as follows; overlapping dpc 95, stone slates 94.1, glazed tiles 82.3, cement sand mortar in plaster with 4% clay giving 66.8, bituminous paint 44, facing bricks 43.7, and finally weep holes in plaster 30.5. All the three objectives were observed to be realistic, and true. And the study therefore concluded that water proofing treatment of masonry walls should be done to heights of not less than 0.70m above DPC level to improve durability of masonry walls against related effects. This provides knowledge, and innovation to the construction industry. And this study also recommends; the use of overlapping of damp proof course, together with slates, as some of the best water proofing materials. There is also need for conducting more research on the areas of; variation of strength of building units with moisture content, and failure mechanism of most water proofing materials.
Compression Index for cohesive soils from Quasi-static Cone Tests
(Kyambogo University (Unpublished work), 2024-04) Bivako, Richard
Compression indexiisiani important soili parameter in the design of foundations of structures yeti the Oedometer test used for its determination is time consuming, cumbersome and very costly. This prompted a number of studies to be done toi address the above limitations by relating Atterberg limits to compression index. However, determination of Atterberg limits has limitations which include stress-strain effects during penetration for the fall cone human reliability errors for the Casagrande method of liquid limits determination and Health & safety issues in handling contaminated soili material for Plastic limits. The aim of this research was toi develop ai simple, fast and accurate method of determining the compression index of cohesive soils using the Quasi-static cone test which addresses all the above limitations. 51i soili samples were collected from three districts of Uganda (Area = 1230km2) and tested for the compression index using Oedometer test, liquid limit using fall cone and Plastic limit using thread rolling. The Atterbergi limits were correlated toi compression index using regression analysis. The same soili samples were tested using the quasiistatic method and forces close toi 1020gfi and 60gfi were obtained for plastic and liquid limit respectively at 20mmi penetration depth. The empirical relationships relating the force from the quasiistatic method and compression index was found toi be 98%i accurate compared toi the compression index from Oedometer test.
Undrained shear strength based on piezocone and laboratory tests for tropical soils
(Kyambogo University (Unpublished work), 2024-06) Mubiru, David
This paper presents a study on the geotechnical properties of two residual soil sites (Buloba a less seismic zone and Buliisa an extreme seismic zone in Uganda) to characterize, propose and recommend models for the estimation of Undrained shear strength (Su). The analysis utilized data from 32 (Thirty-Two) piezocone penetration tests, Twenty-Eight (28) Liquid Limit tests, Twenty-Eight (28) Plastic Limit tests, Twenty-Eight (28) Linear Shrinkage tests, Twelve (12) Consolidation tests, 13 (Thirteen) Consolidated Undrained Triaxial tests. The results showed that the fine content, natural moisture content, liquid limit, plasticity index, and linear shrinkage varied within each site. Furthermore, the undrained shear strength, internal friction, and cohesive values also varied between sites. The study proposed appropriate empirical correlations for obtaining the Su of residual soils, and observed that Nkt value of 56 is proposed for slightly consolidated residual soils while Nkt = 288 should be used for heavily consolidated residual soils during the obtaining of the Su. Furthermore, the study concluded that SHANSEP constants of s = 0.07 and m = 0.82 should be appropriate for estimating the undrained shear strength of residual soils. However, caution should be taken as these empirical relationships are site-specific and considerate of uncertainties. Overall, this paper provides valuable insights for geotechnical engineers to consider for residual soil analysis.
The effect of cow dung ash and banana peels ash as a filler on marshall and volumetric properties of hot mix asphalt
(Kyambogo University (Unpublished work), 2024-05) Ntwirenabo, Coleb
Increased cost of construction materials for flexible pavements has urged researchers to opt for alternative filler materials instead of the conventional cement filler towards greener materials. In this work, cow dung ash (CDA) and banana peels ash (BPA) were investigated as potential substitutes at varied percentage filler contents. The first approach involved replacing the 4 % cement filler content with 25 %, 50 %, 75 % and 100 % with either BPA or CDA filler materials in the Hot Mix Asphalt (HMA). Secondly, the cement filler material within the prepared HMA was fully replaced with either BPA or CDA filler materials at varied amounts of 2 %, 4 %, 6 % and 8 % each. Marshal and volumetric properties including voids in the mix, flow, voids in the mineral aggregate, stability, and voids filled with bitumen in both scenarios were evaluated. Indirect tensile strength (ITS) was obtained for the full cement filler material replacement condition. For partially replacing the cement filler material, optimum parameters were revealed at 50 % CDA and 50 % BPA. For 50 % CDA, voids in the mix, voids in the mineral aggregate (VMA), voids filled with bitumen (VFB), stability and flow were 4.4 %, 16.2 %, 72 %, 16.7 kN, and 3.6 mm respectively. Meanwhile, for 50% BPA, voids in the mix, VMA, VFB, stability and flow were 4.4 %, 16.1 %,72.7 %, 10.63 kN and 3.37 mm. On the other hand, optimum parameters for fully replacing the cement filler material were obtained at 4 % CDA and 4 % BPA. For 4 % CDA, voids in the mix, VMA, VFB, stability and flow were 3.89 %, 16.9 %, 77 %, 13.9 kN, and 3.61 mm respectively. Meanwhile, for 4% BPA, voids in the mix, VMA, VFB, stability and flow were 4.06 %, 16.98 %,76.08 %, 10.7 kN and 3.31 mm. An ITS of 93 % and 98 % for 4 % CDA and 4 % BPA were noted respectively. From the test results, the developed CDA and BPA materials met the Uganda MoWT general specifications for roads and bridges for lighter traffic loading less than 1x106 Equivalent standard axle (ESAS). Thus, the green filler materials portrayed a viable potentiality to substitute the cement filler in the HMA which fosters reduction in the overall cost of road construction materials. This will have a positive impact on the Sustainable Development Goals, specifically targeting SDG 9 (pertaining to Industry, Innovation, and Infrastructure), SDG 11 (focusing on Sustainable Cities and Communities), and SDG 13 (centered around Climate Action).
Investigating the performance of precipitation products and outputs of cmip6 gcms in reproducing precipitation extremes observed across Uganda
(Kyambogo University (Unpublished work), 2024-11) Nakabugo, Joanita Irene
Precipitation products are increasingly being utilized as substitutes for observed precipitation data. This study evaluated the performance of five well-known precipitation products including CFSR, CHIRPS, JRA-55, ERA-5, and PGF and outputs from the CMIP6 General Circulation Models (GCMs) in replicating observed precipitation extremes across Uganda. Annual precipitation extreme events observed at 20 meteorological stations were compared with those from the precipitation products and GCMs outputs over the period 1979-2022. Utilized 6 precipitation extreme indices i.e. total precipitation (TPREC1), annual maxima series (AMS), number of dry days (NDD1), maximum dry spell (MWS1), number of wet days (NWD1), and maximum wet spell (MWS1) using a threshold of 1mm/day. To compare observed data with precipitation products, frequency analysis and bias ratios were applied. Correlation analysis and Taylor diagrams were utilized for comparing observed data with GCMs outputs. The quantile mapping bias correction method, implemented using the qmap package in R Studio, was applied to downscale GCM outputs with both observed data and precipitation products. This approach facilitated the determination of future climate change projections for the SSP2- 8.5 and SSP5-8.5 scenarios for the 2050s and 2080s. PGF systematically overestimated observed AMS at all the selected stations. Contrastingly, JRA-55, ERA-5, and CHIRPS datasets consistently underestimated observed AMS quantiles across all stations and return periods. The regression line for AMS when plotted against log-transformed return period exhibited a steeper slope for CFSR than that of the observed data. The null hypothesis (H0) of no correlation between observed and GCMs-based historical AMS, was rejected in varying proportions of the 20 meteorological stations. For instance, the H0 was rejected (p < 0.05) in 10% of the 20 precipitation stations across Uganda when observed AMS was compared with that of NOR_ESM2. For each of the three GCMs including CESSM_WACCM, INM_CM5, MRI_ESM2, the H0 was rejected (p < 0.05) in 5% of the 20 stations considered. The extent to which GCMs capture precipitation extremes varies due to their coarse spatial resolution. Bias correction of GCM outputs using quantile mapping method yielded different climate change signals in the cases when observations and precipitation products were considered. For instance, climate change impact on the total of precipitation above 1 mm/day intensity were over the ranges 40-170%, 20-61%, 15-41%, 5-36%, 8-67%, and 20-55% when bias correction of GCMs outputs were done using CFSR, PGF, CHIRPS, ERA-5, JRA-55, and observed precipitation, respectively. The choice of precipitation product significantly impacts climate projections. Thus, there is a need for careful selection of which precipitation product should be used for bias correction of GCMs’ outputs in absence of observed precipitation when analysis is being done for planning water resource management and climate change impact assessments.
Exploring the implications of community engagements in ensuring access to safe borehole water in rural setting in Uganda
(Kyambogo University (Unpublished work), 2024-09) Edhaya, David
Groundwater is essential for human consumption, agriculture and industry, traditionally deemed safe due to natural filtration. However, increasing pollution and limited community participation in borehole development have raised contamination concerns in Uganda's rural districts like Arua, Nakaseke, Lyantonde and Bugweri, where this study was conducted. This research examined the relationship between community engagement and borehole water quality using a mixed-methods approach, including surveys, water quality testing and geographical mapping. It assesses how community involvement in borehole site selection, construction, monitoring and maintenance influences water source protection and quality. A total of 530 structured questionnaires were analyzed to gauge engagement levels, while direct water quality analysis was conducted in Bugweri, with secondary data from Nakaseke, Lyantonde and Arua. Results show a significant link between community engagement and water quality, with better quality maintained in districts with higher community involvement. Factors like inadequate drainage and cracks around boreholes contributed to water contamination. For instance, Arua district showed a reduction in E. coli contamination with higher community adherence to borehole maintenance instructions. This study highlights the importance of active community participation in borehole development and maintenance for ensuring safe water access and improving public health, particularly during the wet season.
Investigating factors affecting contractors’ response to local government construction bids in Uganda
(Kyambogo University (Unpublished work), 2024-10) Bafaki, Gilvazio
Bidding is critical in identifying the best bidder for construction projects. More than 55% of Uganda’s national budget is spent through public procurement processes although the execution of the construction projects is not appeasing. This study aimed to investigate factors affecting contractors’ response to Local Government bids in selected districts in south western Uganda. It added new insights to the existing body of knowledge about contractors’ response to LG bids in Uganda which was scanty in literature. Descriptive study design was used and data was collected using questionnaire survey and interview method from a sample of 126 respondents who were randomly and purposively selected from a population of 188 comprised of contractors and community members in the selected districts. To analyse data, SPSS version 20 was used. The study revealed that there is a positive strong relationship between characteristics of construction bids and contractor’s response to LG bids (Pearson = 0.784; P-value = 0.00 < 0.05). The study also found out that there is a positive strong relationship between Factors (capacity, time and contract type) and contractor’s response to LG bids (Pearson value of 0.879; P-value 0.000 < 0.05). A proposed decision model for proficient bidding revealed that if the mark up is ≥ 62% then bidding process must be undertaken. The proposed framework developed showed a coordination gap among actors that can be included in the bid evaluation process. Standard construction bids in Uganda are mainly characterised by high bid security thus local governments should from time to time review the impact of bid security measures on contractor participation in local government construction bids.
Performance evaluation of waste stabilization ponds in the removal of pharmaceutically active compounds : a case of Lubigi wastewater treatment plant
(Kyambogo University (Unpublished work), 2024-11) Asiimwe, Brendah Patience
Waste stabilization ponds (WSPs) have been extensively used for the treatment of wastewater due to their simplicity and cost-effectiveness. This study evaluated the performance of WSPs in removing Pharmaceutically Active Compounds (PhACs) at the Lubigi sewage and wastewater treatment plant. Three wastewater streams were sampled; the inlet for the domestic wastewater stream, the point of discharge for cesspool empties containing faecal sludge from septic tanks, and the gulper station receiving faecal sludge from pit latrines. Additionally, samples were collected at different treatment stages i.e. the inlet to the anaerobic pond, the outlet from the anaerobic pond, and the discharge point to the facultative pond. Fresh and dried sludge samples were also collected. Sample analysis was performed using Liquid Chromatography Mass spectrometry (LC-MS-MS). PhACs were present in median concentrations of 19.223 μgL-1 in wastewater from the sewer network, 13.429 μgL-1 in septage and 18.641 μgL-1 in faecal sludge from pit latrines respectively, with average concentrations of in the three source streams of up to 5300 μgL-1. WSPs exhibited the ability to remove a variety of PhACs from wastewater at an overall removal efficiency of 76.15% with the highest removal efficiency of 70-99.99% for chlortetracycline, sulfapyridine, ampicillin, gentamicin, albendazole, ibuprofen, sulfachloropyridazine, sulfaquinoxaline, and penicillin, the moderate removal efficiency was 50-70% for like paracetamol, chloramphenicol and enrofloxacin, and the lowest removal efficiency of 1-40% for sulfadiazine, oxytetracycline, diclofenac, and ciprofloxacin. PhACs like sulfamethoxazole sulfamerazine and amoxicillin were more recalcitrant exhibiting negative removal efficiencies. The study found that faecal sludge (FS) from pit latrines (3.35 ton/year) and conventional sewer network systems (1.63 ton/year), contribute to substantial volumes of wastewater entering the Lubigi sewage treatment plant and therefore consequently reduce the treatment efficiency of WSPs in removing these PhACs as compared to septic tanks (0.74 ton/year). This study recommends the substitution of pit latrines with source-separated technologies, the addition of maturation ponds and other tertiary treatment mechanisms and the use of advanced treatment technologies to effectively remove PhACs, routine monitoring of PhACs, proper disposal and management of pharmaceutical waste, and further research on the behaviour and fate of PhACs particularly regarding their transformation and potential impacts when discharged into wetland environments.

Browse

Recent Submissions