School of Engineering (SEng.)

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Activated carbon from cassava peels for removal of active pharmaceutical ingredients from wastewater.

(Makerere University, 2022-08) Kayiwa, Ronald

Over the past decade, cassava production has been accelerated, ranking as the 5th most produced food crop at an estimated global production of 298.8 million metric tons by 2020 as per the Food and Agriculture Organization (FAO). With the 10-20% peel composition of the tuber weight, the implied cassava peel production ranges between 29.88 to 59.76 million metric tons. The main application of cassava peels is Papering animal feeds. However, this is limited due to the peels’ low protein content (<6%). Throughout the past decade, cassava peels have been valorized into activated carbons with qualities able to curb recalcitrant adsorbates like heavy metals, dyes, and arsenics. However, the application of cassava peel-based activated carbon in the adsorption of pharmaceuticals from wastewater has not been explicitly studied. This study aimed at modifying the valorization processes of cassava peels into activated carbon capable of removing active pharmaceutical ingredients from wastewater. This involved, (i) characterization of peels of six predominant cassava varieties (NAROCAS 1, NAROCAS 2, NASE 1, NASE 3, NASE 14, and NASE 19) grown in Uganda for production of activated carbon (ii) optimization of activated carbon production conditions from the most viable peel variety, (iii) characterization of the wastewater from effluents of pharmaceutical manufacturing plants (PMPs) and wastewater treatment plants (WWTPs) in Kampala for active pharmaceutical ingredients (APIs), and (iv) determination of the performance of the produced activated carbon towards the removal of active pharmaceutical ingredients from wastewater. All the six cassava peel varieties were potential activated carbon AC precursors with ash contents as low as <5% dry basis and fixed carbon of 13.78–15.34%. NAROCAS 1 cassava peel variety was the most suitable due to its lowest ash content (1.93%), high elemental carbon content (59.40%), balanced volatile matter (81.93%), and fixed carbon content (13.78%). Pre-leaching of the peels using 1– 4% NaOH revealed a more remarkable effect on the increase of volatile matter and fixed carbon (1.00% and 3.56% respectively) than ash content reduction (0.51%). The optimal process conditions for the production of physically activated carbon were found to be a temperature of 782 °C and a heating time of 148 mins resulting in a specific surface area of 756.42 m2g-1, and a yield of 4.57%. The best chemically activated carbon resulted from a 4.0%w/v NaOH pre-leaching at 50 °C and a 5:2 KOH: peel ratio of 5:2 (mass basis) activation at 60 °C for 3 hours. This was followed by carbonization at 780 °C for 2 hours resulting in a 42% yield, total pore volume of 0.756 cm3g-1, and the highest ever reported specific surface area for cassava peel activated carbon (CPAC) of 1684 m2g-1. The concentration ranges of the selected APIs targeted in this study were
Adaptation of the smart methodology to value management of the Uganda School Facilities Grant programme

(Makerere University, 2010-10) Kivumbi, A.D.

In any construction project, the aim of the developer is to maximize profit at minimum cost within the context of the quality possible as per the required specifications. Therefore, loss of resources should be minimized as much as possible, especially in such a crucial project as the School Facilities Grant (SFG) project, so that there is perceived cost-effectiveness. This dissertation considers the adaptation of the Simple Multi-Attribute Rating Technique (SMART) methodology, which is easy and useful for varied decision makers, to Value Management (VM) of the Uganda SFG primary school classroom construction programme in Mukono and Kampala districts. Application of SMART involves interacting with various stakeholders and then holding a key stakeholder workshop through which a shared understanding of the issues under consideration can be reached. This understanding is translated into an information pack developed for use in the workshop. A Value Tree is used as the tool for consideration of opinions by the stakeholders. The allocation of importance weights to the lower – order attributes of the tree provides a rational basis for determining the best-valued Design Option. Each Option is assessed against each of the identified attributes in the evaluation, the assessment being performed by a process of scoring the n Option against each attribute. A Standard Analysis Form is used and the ratio of Aggregated Utility Rating to Estimated Capital Cost, U / C of the ith Design Option calculated, with the highest value of U /C providing the rational choice. The testing of the sensitivity of the outcome of the rating process to marginal changes in the key variables, or Sensitivity Analysis, is then carried out. This was applied to Value Management of the SFG school construction in the two mentioned districts. A brainstorming session was later held to generate a variety of ideas that would also enable the evaluation of the practicality of the identified Option. The SMART methodology was found to be applicable to the SFG programme with the stakeholders being easily comfortable with the common understanding reached. They were also able to make some rational decisions/evaluations of the SFG Design Options. A new policy could be formulated for the programme and the model that has been obtained could be adapted for use for other projects.
An Advanced protection scheme to avert blackouts due to transmission network overload.

( 2018-08-24) Rwendeire, Andrew

The transmission and distribution networks suffer various overloads which have reduced power availability and utility income generation. Some networks employ frequency monitoring with Under Frequency Load Shedding to ensure system stability. However, other conditions that threaten power system stability like the loss of a tie line, overload trip of power transformers, distribution and transmission lines need to be monitored and prevented by implementing protection schemes which automatically shed off the extra load. This will not only improve reliability and continuity of service but also fast decision making to reduce the blackout zone and downtime. This paper presents a load management scheme that performs automatic load shedding and feeder restoration by strictly following the set threshold values using PCM600, an ABB tool. The logic configuration from PCM600 was validated and the Generic Object Oriented Substation Events (GOOSE) report published. The Configured IED Description (CID) file from each IED (in PCM600) was saved in Substation Configuration Language (SCL) format and imported into IEDScout to simulate the IEC61850 communication. The developed model was applied to a case study on the Ugandan transmission network to achieve a 500ms GOOSE messaging sequence on the station bus. IEDScout demonstrated a station-bus traffic data flow rate of 2 kbps responsible for CB commands and status update. The traffic on the Ethernet cable was captured and analyzed using WireShark, a graphic user interface network protocol, two data packets were sent every second through the Ethernet cable and 464 k bytes of data packets were sent as messages on the station bus during the simulation. The model was tested and was able to send a CB open command with in 2ms of overload threshold violation and when the transformer load was reduced, CB close command for load re-connection was sent with in 2ms. A cost benefit ratio of 1.647 was obtained. This model caters for very rare, non-continuous but possible and very catastrophic occurrences on the power system. Therefore, this paper provides an efficient solution to transmission line and transformer overload by automating downstream load-shedding and load restoration.
Analysis of human EMF exposure in close proximity scenarios to cellular system transmitters

(Makerere University, 2024-12-02) Kyemba Kitimbo, Ben

Wireless communication systems, particularly cellular network system, are the primary sources of Non-Ionizing Radiation (NIR) due to their radiofrequency electromagnetic fields (RF-EMF) emission. Excessive exposure of human body to the RF-EMF has been associated with various potential health risks, including nerve stimulation, skin cancer, and alterations in cell membrane permeability. To safeguard human health and the environment, international regulatory bodies such as the International Commission on Non-Ionizing Radiation Protection (ICNIRP) have established guidelines that define the maximum permissible levels of RF-EMF exposure. These guidelines are essential for ensuring that radiation levels remain within safe limits. This study references the ICNIRP 2020 guidelines to evaluate the whole-body exposure compliance of cellular system deployments in Kampala against the permissible levels. Uganda’s telecommunications landscape has experienced rapid growth, marked by the introduction of 5G technology, a 64% internet penetration rate, 34.9 million mobile subscriptions, and over 4,963 base transceiver stations (BTSs). For this assessment, points of investigation (POIs) were strategically selected near radiating antennas at each identified cellular deployment site. The goal of this study was to characterize the RF-EMF exposure from cellular system transmitters in close proximity scenarios. This was achieved by measuring the Power Density (PD) from all the frequency bands in use today. At each POI, PD measurements were taken by directly aligning a spectrum analyzer with the radiating sector antenna. The study utilized an Aaronia AG spectrum analyzer (Spectran HF 60105, 700MHz - 2.5GHz) paired with an omnidirectional antenna (Omni log 90200) to accurately measure PD levels. Across 46 sites, a total of 639 measurements were taken across 8 different frequency bands at 127 POIs. The results indicated an average overall exposure level of only 0.19% of the ICNIRP threshold, demonstrating minimal exposure. Notably, 5G technology contributed 37.56% to the total RF-EMF measured in Kampala. This translates to an overall average exposure of just 0.244% from 5G deployments, further emphasizing its low impact on overall exposure levels. However, the study also identified a few isolated sites with slightly elevated exposure levels, highlighting the need for ongoing monitoring to ensure they remain within safe limits. Keywords: RF-EMF, NIR, INCNIRP, Exposure
An Analysis of Time overruns during the construction of the Uganda Hotel and Tourism Training Institute (UHTTI) in Jinja, Uganda

(Makerere University, 2024-05-31) Nanyanzi, Maria Gorreti

Many construction projects in developing countries including Uganda suffer from time and budget overruns. Generally, time overrun is inevitable in construction projects. There are various factors responsible for the time overrun which require serious attention to understand and address in order to achieve successful completion of projects on time. This is because time overrun has great impact to construction cost which can never be recovered. This paper focused on the discussion of the analysis of time overruns that occurred during the construction of the Uganda Hotel and Tourism Training Institute in Jinja, Uganda. The study in this report is a practical problem developed through experience and observation of the construction of the UHTTI project. This study presents a customized root cause analysis approach to identify the causes of delay, use of the schedule performance index to analyze the schedule performance of the project and provide improvements measures for the causes of the delays identified. From the literature review and project data, the delay factors were categorized into four main causes of delay by responsibility to the contract parties including; contractor, client, consultant and external- related factors. The approach is an analytical approach that uses actual technical data from the project documentation. Various analysis tools are embedded in the approach including: data collection, fishbone diagram, Pareto chart, Pie chart and S-curves. As a result, it was found that the main cause behind the schedule deviations was contractor-related factors. To ameliorate the effects of time overrun, the research recommends that clients engage competent hands to manage projects sites while ensuring they fulfill their own obligation of prompt payment to contractors thereby improving time performance
Analyzing the effectiveness of gasifier-produced biochar as a soil amendment in the humid tropics

(Makerere University, 2009-05) Deal, Christopher William

Biochar is the solid, carbonaceous byproduct from thermal treatment of biomass that is produced specifically for application to soils. Studies have shown that when biochar is added to soils it is able to increase yields, prevent erosion, and effectively store carbon for hundreds to thousands of years. Sizeable research has been conducted using biochar from traditional charcoal kilns as this is the method that maximizes biochar production. Biochar from gasification, however, has been relatively unexamined. The intent of this research, therefore, was to determine if gasifier-produced biochar would act as an effective soil amendment. The motivation behind this study was to create a valuable byproduct from gasification that would also allow the entire process to be considered “carbon-negative.” This investigation was designed to analyze the effectiveness of gasifier-produced biochar through a comparison with kiln-produced biochar. Two types of biomass – maize cobs and eucalyptus wood chunks – were used in the creation of biochar from a gasifier and traditional charcoal kiln. The biochar samples were combined with undisturbed soil from the Makerere University Agricultural Research Institute at Kabanyolo in a 45 day pot experiment to compare effects on plant growth. The experimental results show that, on average, soils amended with gasifier-produced biochar have higher yields than soils amended with kiln-produced biochar. The magnitude of this increase, however, was varied, and this variance was indicative of the sample‟s composition. Biochar composition varied across feedstocks, production methods, and even within samples from the same feedstock and production method. Results indicated that the characteristic with the greatest influence on soil productivity was the soluble ash content in the biochar. Soluble ash, when introduced to soils, helped to increase pH levels. Ugandan soils, like most soils in the humid tropics, are strongly acidic, and this increase in pH allowed for more favorable growing conditions and higher nutrient availability. This study indicates that gasifier-produced biochar has significant potential for use as a soil amendment in the humid tropics. However, further research
Application of gas path analysis for performance monitoring and maintenance evaluation of a turbofan gas turbine

(Makerere University, 2023) Mukoka, Gidion

The aftermarket maintenance service of gas turbines came with a lot of technical challenges that included; low availability of the power plant (33.2) %, poor reliability (66%), and high maintenance costs (28.6%). This was because the guaranteed performance deteriorated even under strict adherence to the manufacturer’s recommended maintenance program. This deterioration was managed by condition-based maintenance (CBM), which was applied through Gas Path Analysis and performance monitoring. The Condition-Based Maintenance strategy was always applied rigidly without assessing the availability, reliability, and need for real-time maintenance requirements. The gas turbines were always subjected to unnecessary major maintenance and overhauls when still in good operating condition and also at times, failing before the guaranteed manufacturer’s approved safety margin of operation. This, therefore, called for an urgent need to develop a performance monitoring approach, that quantifies degradation and evaluates the realtime maintenance effectiveness. This performance monitoring approach used operational data from real installation and a novel model-free data analytics method. This had the advantage of the ease of applicability within the industrial setting. Five performance indices were proposed to be used and tested using the Anova Tool. Performance patterns for Parameter-dependent models were developed using the polynomial curve fitting methods. The maintenance system was evaluated and optimized regarding availability and reliability (safety margin) and overall effectiveness. These gas path parameters were Revolution per minute (N), Air inlet angle (A), Jet nozzle throat area (F), Turbine exhaust Temperature (T), and Vibrations (V). Results showed that Condition-based maintenance could be pushed to 6.3 weeks’ intervals with a range of (5.65±0.65) weeks instead of weekly intervals, however without forgetting the need for pre-post run inspections. This increased availability, and reliability by 26.2% that is to say (71.4 to 97.6) %, and lowered maintenance cost from 28.6% down to 2.5%. A higher performance level of up to 88.5% was achieved from 66.8%. For maintenance cost-effectiveness, a statistical selection method was a function of p-value and its weighted rank, percent error-value (E)and its weighted rank, and Restoration coefficient value (C) and its weighted rank. These were used to select the most effective and responsive parameters for performance indication and monitoring that had a percentage weighted index of above 80%. This boosted the maintenance effectiveness by 20.7% (from 68.8 to 89± 0.5) %.
Application of nanotechnology in the development of briquettes from selected biomass in Uganda

(Makerere University, 2024) Ayaa, Fildah

The development of biomass briquettes remains relevant to communities in developing nations, as they offer a cost-effective and sustainable means of producing energy from solid waste. However, the low quality of the briquettes in comparison to traditional cooking fuels hampers their widespread adoption. The main objective of this research was to develop nanocomposite briquettes with improved ignition and combustion properties. The biochar matrix was obtained from Senna spectabilis, a fast-growing invasive species, while the nanocomposite binder incorporated Cellulose nanocrystals (CNC) from yellow thatching grass (Hyparrhenia filipendula) and Poly-vinyl alcohol (PVA). Novel biochar-CNC-PVA nanocomposite briquettes were developed using the solution casting method, with the CNC/PVA nanocomposite serving as a binder. A total of five biochar/binder nanocomposite briquette ratios were developed: 90:10, 80:20, 70:30, 60:40, and 50:50 and designated BCP (9/1), BCP (8/2), BCP (7/3), BCP (6/4), and BCP (5/5) respectively. The nanocomposite briquettes were characterized for thermal stability, mechanical properties, elemental composition, surface morphology, proximate composition, and combustion characteristics using standard scientific techniques. Thermogravimetric analysis was used to study the combustion characteristics of the nanocomposite briquette decomposition in an oxygen atmosphere at three heating rates of 5,10 and 20 °C/min. The kinetic parameters were determined using the Coats–Redfern method. A production facility for the nanocomposite fuels was modeled using ASPEN Plus software and the economic evaluation conducted using net present value (NPV) and Internal rate of return (IRR) analysis. The briquettes produced had a very low ash contents of less than 2 %, and low moisture content average of 8 %. The fixed carbon and volatile matter content of the briquettes were also within acceptable standards for biomass briquettes. The surface morphology of the briquettes showed a well-distributed nanocomposite binder in the biochar matrix. The nanocomposite fuel blends exhibited calorific values in the range of 16 to 27 MJ/kg, surpassing the calorific values of most organic binder-based biomass briquettes developed earlier. The ignition performance and combustibility indexes in oxy-combustion conditions were highest for the BCP (6/4) blend followed by BCP (8/2) nanocomposite blend. Therefore up to 40 % of the PVA-CNC binder can be added in the biochar matrix without affecting combustion performance. The kinetic studies also showed that the apparent activation energy was lowest for BCP (7/3), with a value of 13.30 kJmol-1 at a heating rate of 5 °C/min. The activation energy at a low heating rate was considered because the heating of the biomass particles occurs gradually, leading to a more effective heat transfer to the material bed and between the particles. The selling price of the nanocomposite fuel, as determined from the techno-economic analysis, was $3/kg, accompanied by an NPV of $13.5 million and a projected payback period of 4.65 years. The calculated Internal rate of return (IRR) of the project is 82 %, indicating a robust level of economic viability. In conclusion, this study provides a detailed protocol for the development of a nanocomposite briquette with improved ignition and combustion properties using locally available biomass and nanomaterials. The use of such briquettes can potentially offer a cost-effective and sustainable means of producing energy from solid waste in developing nations. Further research can focus on optimizing the fuel blends, conducting feasibility studies for scaling up production of nanocomposite briquettes and devising strategies to enhance consumer adoption.
Application of process technologies for improved salt production from Lake Katwe, Uganda

(Makerere University, 2021-12-22) Lwanyaga, Joseph Ddumba

More than 90% of salt used in Uganda is imported from neighboring countries despite the existence of over 22.5 million tons of mineral deposit at Lake Katwe. This is due to the current traditional mining techniques employed at the salt deposit that yield low quantity and quality salt. To avert this, a salt extraction process unique to the brine of Lake Katwe is needed to reduce Uganda’s dependency on imported salt. This study therefore, aimed at application of process technologies for improved salt production from Lake Katwe, Uganda. This involved, a) determining the phase chemistry of the ternary and quaternary systems of Lake Katwe brine particularly considering the effects of temperature, b) developing an extraction process for the various domestic and commercial salts from Katwe brine and c) modeling and validating the salt pan for increased salt productivity in terms of quantity and quality. The Pitzer model embedded in PHREEQC software was used to predict the precipitating salts, their respective yield, and the order in which they crystallize from Lake Katwe brine. This was supplemented by computing the phase diagram using the Extended UNIQUAC employed in the MATLAB environment. To validate the thermodynamic calculations, isothermal evaporation experiments were done. The mineralogy and morphology of the precipitates from the isothermal experiments were determined by the XRD and SEM techniques, respectively. Furthermore, by using the Taguchi experimental design method, the parameters affecting the crystallization of halite from brine were investigated. The salt pan, an integral part of the solar salt works was modeled to optimize its dimensions in OpenFOAM. A techno-economic analysis followed in SuperPro Designer where the process flow sheets were modeled. The precipitation sequence mainly started with sulfate followed by chlorides and lastly carbonates at all temperatures after the precipitation of the carbonates of calcium and magnesium. Halite emerged the most dominant mineral, with thernadite, trona and glaserite following respectively. Thenardite, glaserite, and burkeite precipitation flourished at lower temperatures (30 & 40 ℃) whereas soda ash precipitation flourished at higher temperatures (60 & 70 ℃). Halite equally precipitated at all temperatures thus not showing temperature preference. The signal-to-noise analysis aimed at determining the effects of several parameters on halite crystallization. The results showed that the optimum conditions for maximum crystal yield were achieved when the feed concentration, mixer speed, residence time, and heating load are 0.248 g of NaCl/g of solution, 830 rpm, 50 min, and 1400 W, respectively. Moreover, the ANOVA results indicated that the residence time and heating load are the most significant parameters influencing the salt crystal yield with a contribution of 57.11% and 20.07%, respectively. The mixer speed and feed concentration had the smallest effect on the crystal yield with a contribution of 19.55% and 3.3%, respectively. Efforts were made to enhance the salt pan performance, the model results from OpenFOAM revealed that a depth of 0.1 m produced the highest brine temperature. Thus, the salt pan should be as shallow as practically possible. Results from the techno-economic analysis showed that halite of purity >99% was produced after the flotation of burkeite and trona. Additionally, soda ash and sodium sulfate were produced by a combination of flotation, carbonation, and calcination techniques. The unit production cost of halite was 0.2629 and 0.4724 $/kg with an NPV of $2,447,853 and -12,085,796 of the solar salt and mechanical evaporation processes respectively. As a result, the solar salt extraction process proved feasible from both engineering and economic standpoints and thus can be scaled up to a pilot-scale using conventional industrial equipment.
Architecture and materials implications on energy efficiency in buildings

(Makerere University, 2014) Kawuki, Joseph

Materials and architecture have a big effect on the energy consumption of buildings. Poor architecture and material selection has led to an increase in energy demand for buildings hence Energy efficiency has become the key driver for the construction industry. This study aimed at investigating the effect of architecture and building material selection on the energy efficiency of buildings. This was accomplished by studying the relationship between the thermal properties of the building materials and the energy consumption of the building in relation to the building design for with office buildings as case study. Architectural design plays a great role in the accommodation of day lighting and solar radiation in the building which contribute to lighting and cooling load. The study of the materials used in the construction and the architecture of the two office buildings in the same location serving the same purpose gave a good comparison of the effect of the materials and architecture on energy efficiency of buildings. The thermal properties and energy data of both building gave the following; Amber house had an average of 342.5 lux day lighting as compared to 335.60lux for Workers’ House. The inside temperature of the buildings were measured and an average of 260C was obtained for both building although these buildings have different cooling systems which require different amount of energy, ventilation and air conditioning load are dependent on the orientations and materials used the building. Building (Workers’ House) with tinted glass materials for the window require a less of artificial lighting because of the window to door ratio and a lot of cooling energy. While buildings (Amber House) with concrete finish material have envelope thermal transfer value of 83.02W/m2 compared to 183.03W/m2 of marble tiles finish. It’s from this basis that the model was developed. The model compares the wall to window ratio, materials used in construction (windows and opaque walls) and the orientation of the building to solar radiation. The glass materials for the windows must be in such a way that it allows in less direct solar heat gain but allows a lot of day lighting. The orientation of the model has been in such a way that the building is zoned with respect to activities to be carried out in the building. Since the temperature ranges of the Kampala are between 180C and 350C, the architectural model is oriented in such a way to minimum solar radiation is gained in the buildings to provide temperatures comfortable for human beings. The architectural model was developed to set a benchmark for the architectural and materials selection for an energy efficient office building in Kampala.
Assessing Ecosystem service values due to land use and land cover changes in the forested landscapes of Hoima District.

(Makerere University, 2022-02-02) Naggayi, Phiona

Land use and Land cover change (LULCC) attributed to natural factors and human activities has led to the loss of ecosystem services, making the quantitative valuation of ecosystem services the scientific focal point for sustainable development. This study assessed changes in the ecosystem services values (ESVs) due to LULCC during the period 1990–2020 in the forested landscapes of Hoima district, located in Western Uganda. Moderate resolution Landsat images from 1990, 2000,2011 and 2020 were obtained and analyzed using a random forest (RF) algorithm for classification, and ArcGIS Desktop software (version 10.5, Esri,) for mapping to assess the LULCC. The ESVs were estimated based on the benefit transfer approach using modified local value coefficients. The results revealed that the aggregated ESVs of the Forests, Grassland, Wetlands, and Water had decreased, consequently leading to a total loss of US$ 27.8 million (3.4%) in ESVs over the past 30 years. Moreover, the loss in the ESV was attributed to the decreased values of water regulation, climate regulation, erosion control, nutrient cycling, habitat/refugia, and water supply, with the exception of the values of food production and biological control, which gradually increased during the study period. This study provided minimum estimates of the ecosystem service values, which will contribute to the formulation of policy actions and strategies for sustainable management of the study area and other similar landscapes and inform various stakeholders on the tradeoffs involved in the use of land resources. Hence, to enhance the continuous supply of ES and economic development, an integrated approach to managing land and water resources is recommended. Moreover, Payment for ES is also a potential remedy for ES loss at the regional and local scale.
Assessing the compliance of kombucha beverage to Uganda national standards

(Makerere University, 2024-09) Mwandha, Anthony

Kombucha, a popular fermented beverage in Uganda, has been embraced for its perceived nutritional and health benefits, despite limited scientific evidence supporting these claims. This study aimed to assess the compliance of Kombucha processing with national standards and therefore the quality of Kombucha products available in the Ugandan market was evaluated. Thirty randomly collected sample product brands from wholesale shops, retail stores, and supermarkets portioned into alcoholic Kombucha (n=21) and non- alcoholic Kombucha (n=9) were analyzed for microbiological, chemical, and physical labeling characteristics. The certification status of each brand was verified against Uganda National Bureau of Standards (UNBS) Quality distinctive mark and presence on the list of registered manufacturers. A descriptive survey consisting of structured questionnaires, interviews, observations, and inspections was utilized to obtain quantitative data in order to find any gaps in the application of the US 2037:2019 Kombucha specification. Regression analysis was used to analyze only the independent variables (p<0.05) that showed bivariate correlation in order to investigate the relationship between industry quality management factors, such as material inputs, Good Manufacturing Practices (GMP), Good Hygiene Practices (GHP),human elements and methods, equipment technology, training, employee satisfaction, and customer satisfaction, and product quality. Microbiological analysis revealed that all 30 brands met the requirements for Staphylococcus aureus, Escherichia coli, and Salmonella spp. The descriptive data for the non-alcoholic Kombucha, when subjected to a t-test, indicated a significant difference (p<0.05) in the test parameters of acidity (acetic acid and lactic acid),alcohol content, yeasts and moulds, suggesting that the product differed from the UNBS requirements. In contrast alcoholic Kombucha t-test revealed that only lactic acid content and alcohol content did not have a significant difference (p> 0.05) implying they were meeting the UNBS specification. The PlanDo-Check-Act (PDCA) cycle was used to create a standardization framework for Kombucha drinks by comparing current practices with ISO 22000 standards. Experts in the field who demonstrated its applicability and effectiveness for ongoing improvement within the Kombucha business validated the framework. Overall, this study shows that Ugandan Kombucha manufacturers do not adhere to national regulatory standards, which raises serious concerns about consumer food safety. To get substandard and noncompliant products off the Ugandan market, the regulatory body should step up its efforts to enforce the market.
Assessing the effectiveness of technical vocational education and training in promoting industrial growth.

(Makerere University, 2024-11-05) Obini, Denis

In recent times, the industrial sector has emerged as a crucial catalyst for economic expansion, employment generation, and technological progress. In order to fortify the longevity and competitive edge of this industrial domain, the spotlight has turned to vocational education programs as a pivotal avenue for nurturing a proficient workforce capable of addressing evolving industry requirements. This study endeavors to evaluate the efficacy of vocational education within Uganda's central region in fostering the growth of the industrial sector. This assessment encompasses a holistic analysis spanning across diverse dimensions, aiming to provide comprehensive insights into the matter. The research utilized a mixed-methods framework, synergizing quantitative data analysis with qualitative interviews, to meticulously evaluate the influence of vocational education on the maturation and progress of the industrial sector. This investigative approach encompasses the collection of primary data via surveys and in-depth interviews involving a spectrum of stakeholders, including industry experts, policy formulators, educators, and students. Moreover, supplementary data from pertinent reservoirs like government records, scholarly literature, and industry digests underwent scrutiny to furnish a comprehensive backdrop for the study's evaluation. The study thoroughly examined factors like classroom facilities, instructor qualifications, workshops, labs, industry ties, and quality controls. Using statistical analysis, it identified a Center of Excellence in vocational education through the Simple Additive Weighting Technique within Multi-Criteria Decision Making. Results revealed varied compliance levels: Low (63.2%), Moderate (8.5%), High (21.8%), Very High (6.5%) and no non-compliance. This highlights room for improvement, especially in workshops due to resource constraints and tutor expertise. The study's insights benefit policymakers, educators, and industry stakeholders, pinpointing strengths and weaknesses using SWOT analysis, while advancing understanding of vocational education's link to industrial growth. It offers data-driven recommendations for vocational education program enhancement amidst changing technological and labor market landscapes.1
Assessing the efficiency of indigenous soil and water conservation methods used in Mountainous regions of Uganda (case study of Nyamiyaga village Kisoro District)

(Makerere University, 2024-01-12) Monday, Gideon

Water and soil are basic natural resources that support life in all forms. These resources are scarce to meet the increasing demands of man, which calls for their conservation. The purpose of the study was therefore to assess the efficiency of indigenous/traditional practices of soil and water conservation (SWC) in mountainous regions of Uganda, case of Nyamiyaga village Kisoro District and design appropriate SWC measures for sustainable management of these resources. The specific objectives of the study were; Assessing the farmers’ perspective on causes and effects of soil erosion in the study area, examining indigenous SWC practices and designing appropriate measures for SWC in moutaineous regions utilising the local knowledge. Primary data was collected using slit trap experiments, taking measurements of existing SWC structures and using a structured questionnaire, while secondary data was obtained from Uganda National Meteorological Authority, United States Geological Survey and literature. Analysis was done using Excel, SPSS and Arc GIS 10.5. Soil Conservation Service (SCS) method was used to determine total annual runoff volume while soil erosion potential was assessed using the Revised Universal Soil Loss Equation. The study revealed that average annual soil erosion rate for the micro catchments was 318 tons ha- 1 yr-1 (classified as very severe), while averege annual runnoff volume at a 2 year return period was estimated at 1,497m3. This affects the design, construction and operation of hydraulic structures (such as dams, reservoirs and waterways to manage water resources for domestic and agriculture), watershed management (such water quality and quantity management, flood control, and sustainable use of natural resources), environmental impact assessment of development projects (such as roads, housing, mines, and industrial facilities) and agricultural productivity of farmers, in absence of improved SWC measures. Major traditional practices of SWC were identified as soil erosion control fences, terrace with fanya juu, water retention trenches, erosion control stone bunds, fallowing and rainwater harvesting tanks. Using slit traps, the study examined the efficiency of the the major indigenous SWC structures and came up with improved structural designs of these structures to enhence their performance. Modifications made include; introducing a foundation trench for stone bunds of 15cm and adjusting their cross sectional area from 0.07m2 to 0.10m2, reducing the spacing between stakes for erosion fences from 4m to 3m and introducing fodder trees between them, increasingxiii the cross sectional area of water retention trenches from 0.16m2 to 0.25m2, increasing cross sectional area of a bench terrace from 0.12m2 to 0.18m2 and increasing the capacity of a RWHT from 3m3 to 7.5m3. The efficiency of the improved measures was found to be 95% as compared to 75% of the indigenous methods. Finally, the study recommended similar studies on other slopes of Kisoro and Uganda in general, studies on gender in relation to SWC and studies into factors affecting the adoption of modern methods of SWC in the catchment.
Assessing the impacts of climate change on rain fed agriculture and the use of rainwater harvesting for mitigating its effects in Teso sub-region.

(Makerere University, 2023-05-19) Nampala, Jesca Sserwanga

The most severe effect of climate change is the alteration of the hydrological cycle and extreme events which in turn affect rainfed agriculture. It impacts the quantity and quality of water resources at both spatial and temporal scale, according to IPCC 2001, African countries are more vulnerable to these changes due to lack of institutional capacity and low levels of economic development. In Uganda, most of the population depends on rainfed agriculture. The study assessed the impacts of climate change on rainfed agriculture in Teso sub-region. In this study, the impacts of climate change were assessed using the downscaled climate projected data from the NorESM1 General Circulation Model (GCM) in two scenarios RCP4.5 and RCP 8.5 for 2040-2060 period in Teso subregion. The study applied the Man-Kendall (MK) test using the XLSTAT software 2019, to calculate the variation in the rainfall and temperature in the observed and predicated data (trends) over the region and the detection of the magnitude of the trend (slope) was calculated using the Sen’s slope estimator method (change per year). The variability in precipitation was calculated using the coefficient of variability and the variability index to determine the dry years and the severity of the droughts, the FAO CROPWAT 8.0 and CLIMWAT 2.0 simulation software’s were used to calculate the crop water demand and the available future runoff. The analysis showed generally, the temperature was projected to increase by 1.18oC at RCP 4.5 and 2.7oC at RCP 8.5. There is an insignificant decrease in total annual precipitation in the projected 21-year period of 26% and 23.9% at RCP 4.5 and 8.5 respectively. The inter annual variability was calculated as 14% in the baseline, and 17% and 19% at RCP 8.5and 4.5 respectively. The projected dry years where 2041, 2042, 2046, 2057 and 2041, 2046, 2048, 2052, 2060 for RCP8.5 and 4.5 respectively. The potential rainfall runoffs were 614mm, 728mm, and 781mm per year while the crop water demand was 301.5mm, 555.6mm and 544.4mm per year under the baseline and RCP4.5 and RCP8.5 scenarios respectively. From these results, it was evident that the temperature in sub-region is rising, and this leads to an increase to crop water demand thus affecting agriculture. There is both a horizontal and vertical shift in the rainfall patterns especially the start dates of the rainy seasons and the associated extreme weather events. The projected increase in temperature was 1.18oC at RCP 4.5 and 2.7oC at RCP 8.5, However, the increase in precipitation statistically insignificant overtime. The potential rainfall runoff is higher than the crop water demand in all the scenarios and therefore, sufficient rainwater runoff can be harvested to satisfy the crop water demand.
Assessing the impacts of land use and land cover change on stream flows of river Kyambura

(Makerere University, 2022-03) Galabuzi, Dennis Ssozi

The impacts of land-use land cover changes on hydrological systems has received considerable attention from researchers and practitioners world over. At catchment level, land-cover changes and their effects on the hydrologic processes remain a major challenge. River Kyambura catchment located in the western part of Uganda has experienced noticeable land use and land cover changes but their impact on hydrological processes are not yet well understood. This study aimed at assessing the impacts of land use and land cover changes on the streamflows of River Kyambura using a modelling approach. A Soil Water Assessment Tool (SWAT) model of River Kyambura was set up, calibrated and validated using daily streamflow data obtained from the Directorate of Water Resources Management for the Kyambura gauging station located at lat. 00011'22"S, lon. 030006'11"E. Coefficient of Determination (R2) was used as the objective function as a measure of model performance during calibration and validation. The model calibration and validation processes gave R2 values of 0.78 and 0.688 respectively. ArcSWAT was also used to classify the land use-cover maps from Landsat satellite images acquired for the year 1989, 2009 and 2019 respectively using the Maximum Likelihood Algorithm for Supervised Classification. The Kappa coefficient objective was used to determine the classification accuracy for the different landuse images. Coefficients of 0.86, 0.96 and 0.96 were obtained for the 1989, 2009 and 2019 imagery respectively. The land use maps of 1989, 2009 and 2019 were analysed for land cover changes. The results showed that more significant land cover changes occurred after 2009 with an increase in vegetation cover of 24.53% and a decrease in barren land of 27.69%. Built up areas had a 3.50% increment whereas open water decreased by 0.33%. The effects of land-use changes on stream flow were assessed by using the calibrated SWAT model. The model results showed a reduction in water yield for both the first (1989–2009) and second (2009–2019) periods. These periods were marked with an increase in vegetation cover. The water yield was also found to be directly proportional to precipitation, surface runoff, lateral flow, groundwater flow, percolation and evapotranspiration in the period of 1989 to 2019. The results obtained in this study can provide useful information for water resource planning and management as well as soil and water conservation in the Kyambura catchment.
Assessing the integrated impact of climate and land use/cover changes on groundwater recharge

(Makerere University, 2023-11-09) Lukwago, Geoffrey

Climate and land use/cover (LULC) change affects groundwater recharge through alteration of the hydrological cycles especially in major agricultural and rapid population growth areas. However, studies on the combined effect of climate and LULC changes on groundwater recharge are scanty. Therefore, this study applied SWAT–MODFLOW to assess the combined impact of changing climate and LULC on groundwater recharge in Sezibwa sub-catchment, Uganda. The model was calibrated using River Sezibwa records and average static groundwater levels. Climate projections for the MIROC5 global circulation model (GCM) under RCP 4.5 and RCP 8.5 were downscaled for the period 2020–2070 and used to model impacts of future climate changes in the catchment. The Cellular Automata-Markov model was used to project LULC changes for the periods 2020-2040 and 2040-2070. Relative to the baseline scenario (1999 – 2019), The results showed that in the study period (2020 – 2070), minimum (18.3 °C) and maximum (30.29 °C) temperatures are projected to increase between 0.54 °C - 1.02°C and 0.56°C-1.7°C for RCP4.5. While for RCP 8.5 temperatures increased between 0.47°C- 1.07°C and 0.55°C-1.75°C for both minimum and maximum temperatures. The average daily precipitation relatively remains unchanged for the 2020 – 2039 under both RCP 4.5 and RCP 8.5 scenarios, however, it decreases by –1.22% for the time period 2040 – 2070 in comparison with baseline average daily precipitation of 3.5 mm/day. The dominant LULC was small scale farming in 2019 (1446.5 km2). LULC projections from 2019 to 2070 showed that built-up areas are expected to increase by 48.7%. Woodlands on the other hand will reduce by 63.3%. The calibrated SWAT-MODFLOW model showed that under the baseline scenario, the average groundwater recharge was 198 mm/year. Considering only climate changes, the average annual ground water recharge is expected to reduce between 9.53- 11.5% for RCP 4.5 while for RCP 8.5 the decrease will be between 6-9.68% relative to baseline scenario of the study period 2020-2070. However, if land use/cover change is considered only, the recharge decrease for study period will vary between 0.05 – 1.06%. When the integrated climate and LULC changes are considered, average annual ground water recharge is expected to decrease recharge between 4.05%- 18.17% under RCP 4.5, while for RCP 8.5, recharge is expected to reduce between 2.16% - 17.70% for the study period. Climate and LULC changes individually impacts ground water recharge. However, the effects are more pronounced when both drivers are combined. Therefore, authorities responsible for water resource management should consider combined effects of climate and LULC changes in planning and management of groundwater systems.
Assessing the relative influence of future climate and land use changes on flow Dynamics in the upper Rwizi catchment

(Makerere University, 2024) Kyeyune, Joseph

This study addresses the relative influence of future climate and land use changes on River Rwizi’s hydrology, a currently water-stressed catchment in western Uganda. Although many studies have evaluated these factors separately, few have considered their combined effects or quantitatively distinguished their relative contributions. Using an ensemble of six CORDEX Regional Climate Models (RCMs), the study projected future temperature and precipitation changes under moderate (RCP 4.5) and high (RCP 8.5) emissions scenarios. The Cellular Automata-Artificial Neural Network (CA-ANN) model was applied to predict land use changes by 2048. Hydrological simulations were then performed using the Soil and Water Assessment Tool (SWAT) under three scenarios: land use change alone, climate change alone, and a combined scenario. Results showed that land use change alone would increase River Rwizi’s total annual flow by 47.3%, while climate change alone would decrease it by 9.8%. The combined scenario showed a 20.9% increase in annual flow, highlighting the stronger influence of land use changes on total annual runoff. All scenarios projected increases in high-flow events, based on 10-year flow quantiles, with the combined scenario producing the highest increases: 77.7% under RCP 4.5 and 75.05% under RCP 8.5. Climate change alone also significantly increased high flows, with rises of 64.7% (RCP 4.5) and 73.5% (RCP 8.5). In contrast, low flow quantiles decreased under both land use and climate change scenarios, particularly under the combined scenario, suggesting potential low-flow challenges for water supply. Attribution analysis identified climate change as the primary driver of increased high flows, heightening flood risks, while land use changes were more influential on total annual and extreme low flows, impacting water availability for Mbarara. The findings underscore the importance of integrated water management that addresses both factors. To ensure sustainable water resources, a dual approach is recommended. First, implement stringent land use policies to help regulate annual and low flows critical for consistent water supply. Second, adopt climate adaptation strategies, such as flood management, to mitigate the risks posed by increased peak flows. This balanced approach is essential for sustaining water supply in Mbarara and maintaining the River Rwizi’s hydrological balance.
Assessment of Uganda's internet Ecosystem through internet measurements.

(Makerere University, 2023-12-15) Galiwango, Martin

Internet connectivity has proved to be beneficial to the end users in terms of economic, educational and social opportunities as well as health, which has increased the number of Ugandans accessing the Internet. Unfortunately, information about the Internet connectivity topology between the different Autonomous Systems (AS) in Uganda is limited and only known to the ASes themselves and a few people. Therefore, few people are aware of the source and destination of the information they are accessing over the Internet and the paths this information takes as it is traversing through the Internet. In order to reveal the topological information about the connectivity of ASes in Uganda such as latency, Internet measurement campaigns need to be intensified and the number of vantage points where this information can be captured need to be increased. This research aimed at carrying out Internet measurements on ASes in Uganda focusing on five ASes. The research analysed the Internet paths between the different ASes in Uganda and key selected points across the world. The data collected was supplemented by additional data from Centre for Applied Internet Data Analysis (CAIDA), Reseaux IP Europeens (RIPE) Atlas and Measurement Lab (M-Lab). The results from the research indicate that Kenya plays a vital role in providing access to the undersea cables at the East African coast to Ugandan Internet Service Providers (ISPs). It is observed from the results that the Uganda Internet eXchange Point (UIXP) promoted local peering and reduced latency towards access to Google services. The results further demonstrate the dominance of companies outside of Uganda hosting government websites and most of the popular websites in Uganda in 2018. This is counter to principles in the Data Protection and Privacy Act which became law in 2019. However, this trend changed in 2020 where most of the Ministries Departments Agencies (MDA) websites where hosted in Uganda. It was further noted that .ug domain name server hosted in Uganda had the lowest query time as compared to name servers hosted outside of the country.
Assessment and modeling of grid related factors that influence quality of supply to industrial customers

( 2018-11) Oola, Jimmy Noel Sande

Industrial development is directly linked to the growth of a country’s economy. As Uganda claims to approach middle income status by 2020, it was imperative to look at grid related factors that influence quality of supply to industrial customers. This is because industrial customers constitute 9% of the customer base but consume 74% of the power produced. Hence when the quality of supply improves for the minority group of customers, then this will ensure sustainable economic growth. The research involved soliciting responses from customers using questionnaires, observation of network assets in the field and analysis of existing data on the performance of the power supply. An electrical model was developed to simulate the impact of changes in asset management practices on power quality. Reliability of power supply was analysed using Monte Carlo Simulation in Matlab programme. The research was conducted on Umeme Limited network of Natete District. Findings from the research revealed that 19% of the transformers were leaking and required preventive maintenance and 18% had one or more surge arrestors missing hence not properly protected against lightning. Of all the structures inspected, 2% had rotten poles and 11% required line clearance due to tree branches approaching or touching the power lines. These findings reveal signs of poor asset management practices which negatively affects the quality of supply to industrial customers. It was demonstrated that poor asset management practices due to inadequate maintenance negatively impact on power quality for industrial customers due to increase in contact resistance as a result of poor fusing, poorly made jumpers and joints. When resistances changes by 0.01ohms, voltage for medium industrial customer changes from 237.8V to 234.5V representing 1% drop in voltage. However further increase in resistance is likely to cause the voltage to drop below 6% which is the grid code threshold. The change in resistance significantly affect medium industrial and commercial customers compared to heavy industrial customers. Poor asset management practices reduce the mean time to failure of electrical components which reduces the overall reliability of the supply. A component which takes 1 year (8760 hours) to operate without breaking down will have a reliability of 0.977. However due to poor asset management practices, the component may break down say after 6000 hours which then reduces its reliability to 0.964. Good asset management practices therefore improves power quality by minimizing contact resistance and reliability by good maintenance practices for industrial customers.

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