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ItemInvestigations into moisture damage resistance of Nano-Modified Asphalt mixtures using granitic aggregates and 50/70 Penetration Grade Binder(Makerere University, 2026)Moisture-induced damage is a major concern in asphalt mixtures because water infiltration weakens the bitumen–aggregate bond and reduces mixture strength and durability. This study investigated the influence of nano-modification on the mechanical and moisture-resistance properties of hot-mix asphalt (HMA) prepared using 50/70 penetration-grade bitumen and crushed granitic aggregates from three quarry sources in Northern Uganda. Nano-bentonite, nano-calcium carbonate (nano-CaCO₃), and liquid ZycoTherm were evaluated at 2%, 4%, and 6%; 3%, 6%, and 9%; and 0.1%, 0.2%, and 0.3%, respectively, by weight of bitumen. An unmodified mixture served as the control. The experimental program evaluated bulk density, Marshall Stability, Marshall Flow, Marshall Quotient (MQ), air voids, Voids in Mineral Aggregates (VMA), Voids Filled with Asphalt (VFA), indirect tensile strength (ITS), and Tensile Strength Ratio (TSR). Moisture susceptibility was assessed by comparing conditioned and unconditioned specimens, while analysis of variance (ANOVA) was used to determine the significance of the investigated factors. The results showed that nano-modification generally improved the mechanical and moisture-resistance properties of the HMA mixtures, although responses varied with nanomaterial type, dosage, and aggregate source. The most favorable overall responses within the investigated ranges were obtained at 4% nano-bentonite, 6% nano-CaCO₃, and 0.2% liquid ZycoTherm. Liquid ZycoTherm produced the most favorable TSR response, while nano-bentonite and nano-CaCO₃ generally produced stronger mechanical responses. Aggregate source significantly affected TSR but not Marshall Stability or MQ. ANOVA showed that factors with p < 0.05 were statistically significant. However, statistical significance did not imply high explanatory power. The R² values were 0.397 for Marshall Stability, 0.236 for MQ, and 0.229 for TSR, indicating that the models explained 39.7%, 23.6%, and 22.9% of the observed variability, respectively. The relatively low R² values, particularly for MQ and TSR, indicate limited explanatory power and support further investigation using additional material, mixture, conditioning, and performance-related variables.
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ItemDeveloping a pedestrian route choice model for university students in Kampala : case study of Makerere University(Makerere University, 2025)Universities in African cities are intensely walkable, yet evidence on how route features shape pedestrian choices is scarce. This study models student route choice at Makerere University in Kampala using both stated preferences from 106 respondents and revealed preferences for 309 trips from 105 participants captured with a mobile GPS application. Choice sets were generated with Yen’s k-shortest paths on the OSM campus network, and the route attributes such as length, greenery, sidewalk availability, slope, and amenity presence were computed in ArcGIS. Multinomial and path-size logit models were estimated using Apollo package in R software. Whereas the SP model indicates disutility for time and slope and positive utilities for greenery and amenities, the RP model revealed that, students frequently choose longer, greener, off-street routes, avoiding busy routes with high amenity counts and sidewalks. Joint SP and RP estimation tightened model inference with five of six coefficients significant at 5% level of confidence and recovered a large SP scaling parameter, consistent with lower SP error variance and efficient experiment design. Out-of-sample validation with repeated 70/30 holdouts showed small estimation–validation gaps with the joint model exhibiting the best generalisation. Policy-wise, greening internal connectors and reducing pedestrian exposure to traffic appear more effective than adding sidewalks along busy corridors. The study’s convenience sample and the controlled campus environment limit external validity, but results provide actionable evidence for institutional hubs and a foundation for larger, city-scale studies enriched with situational variables such as time of day, weather, lighting, safety and volume of traffic.
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ItemA techno-economic feasibility study of pv systems application in the telecommunication industry in Burundi(Makerere University, 2026)Burundi’s telecommunication industry faces persistent energy challenges due to unreliable grid infrastructure and heavy reliance on diesel generators, particularly in off-grid regions. These constraints have led to elevated operational costs and hindered service reliability. This study evaluated the techno-economic feasibility of deploying photovoltaic (PV) systems to sustainably power telecom infrastructure in Burundi, using selected sites in Burundi. A combination of site surveys, solar resource assessments, and simulation tools (PVGIS and HOMER Pro) was used to model energy output, system performance, and economic viability under PV-only and hybrid (PV+diesel) configurations. Load profile analysis revealed average daily energy demands of 67 kWh, 44 kWh, and 33 kWh for the hub, up, and end sites, respectively. Solar resource assessment showed an average annual global horizontal irradiance (GHI) of 4.9 to 5.4 kWh/m²/day, indicating strong solar energy potential. Optimised hybrid simulations indicated full load coverage with excess electricity < 9%, while PV-only systems produced up to 58% excess energy but with unmet load ranging from 0.05% to 0.37% due to shading and variability. Economic analysis demonstrated superior performance for hybrid systems, with an average Return on Investment (ROI) of 157%, a Net Present Value (NPV) of USD 91,000, and a Levelized Cost of Energy (LCOE) of US Dollar cents 36/kWh, significantly lower than US Dollar cents 75/kWh for PV-only setups. Sensitivity analysis indicated that system efficiency was influenced by battery sizing, load variation, and sitespecific shading. The findings allude to the fact that PV-diesel hybrid systems present the most viable solution for reducing fuel consumption, enhancing energy reliability, and lowering operational costs in Burundi’s telecom sector. The study recommends a phased roadmap for PV integration and policy reforms to enable broader adoption. These results underscore PV’s transformative role in supporting resilient, affordable, and sustainable energy systems across critical industrial sectors in Burundi.
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Item3D Electrospun poly L-lactic acid nanofibrous structures coated with regenerated silk fibroin and silver nitrate for burn wounds(Makerere University, 2026)Pediatric burn victims, who are the majority in Uganda, are treated with cotton gauze embedded with topical creams that require painful, frequent changes because of their adherence tendency due to absorption properties. This research developed a 3D-ES poly L-lactic acid (PLLA) nanofibrous structure coated with antibacterial properties that is also biocompatible and biodegradable. An optimized pristine 3D-ES structure had a height of 23.58 mm and a fiber diameter of 0.77 ± 0.05 µm (p > 0.05), suggesting uniform fiber diameters. It had a contact angle of 120°, 40.3% in vitro degradation, and 480.29% fluid take-up on Day 4. No cytotoxicity was observed by Lactate dehydrogenase (LDH) release assay, and cells adhered and grew, indicating biocompatibility. The 3D-ES structure was coated with regenerated silk fibroin (RSF), whose optimized extraction process was based on Activity-Based Costing (ABC) accounting for the total cost of producing 1 g of RSF, which cost $ 100.06 compared to the $379.58 cost of 1 g of Lyophilized RSF. With optimized spray parameters, silver nitrate (AgNO3) was coated onto the 3D-ES structure. Prior, the minimum inhibitory concentration (MIC) and maximum bactericidal concentration (MBC) of 0.5 mg mL-1 AgNO3 were analyzed and recorded as the 1st and Neat for all standard and clinical isolates for S. aureus and E. coli. The zone of inhibition (ZOI) decreased with increasing serial dilution, with the widest clearance being 24 mm for SE. coli clinical isolate. Overall, the 3D-ES PLLA structure coated with RSF and AgNO3 was biodegradable, biocompatible, and had antibacterial properties. This research introduces the potential of using 3D-ES drug-loaded structures as potential wound dressings.
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ItemModelling of the Behavior of the Heated Crude oil in the East African Crude oil Pipeline.(Makerere University, 2026)The East African Crude Oil Pipeline (EACOP) is designed to transport waxy crude oil from Uganda to the port of Tanga, Tanzania. Uganda's crude oil has a uniquely high pour point of 40°C, making active heating necessary for flow assurance. This research developed an integrated numerical model (Finite Element Method (FEM) and Computational Fluid Dynamics (CFD) in ANSYS) to simulate the behavior of heated crude oil in the East African Crude Oil Pipeline (EACOP) under normal and failure scenarios. The specific objectives were to quantify radial heat loss across the pipe cross‑section for different crude oil fill levels (full, ¾, ½, ¼ bore) and ambient soil temperatures (18 °C to 35 °C), to simulate temperature, velocity, and viscosity profiles along an 18 m pipeline section for five scenarios (normal operation: 50 °C inlet temperature with 70 °C heat trace , heating failure at 50 °C and 40 °C inlet temperature) and to assess the impact of a 20 mm wax layer on those profiles under heating failure at the same two inlet temperatures. The key findings were firstly, the polyurethane foam (PUF) layer contributed 97.8 % of the total thermal resistance, heat loss varied by 32.8 % across the soil temperature range and fill level had a negligible effect when crude oil was present in the pipe. Secondly, under normal heating, the temperature drop was only 2‑3 °C over 18 m and viscosity remained constant; without heating and with a 40 °C inlet, the crude oil cool ed below its pour point (36.5 °C) and viscosity increased by 300 %. Thirdly, a 20 mm wax layer caused a 31‑47 % velocity increase: however, while offering a minor thermal insulation (10 % reduction in cooling rate). The FEM cross‑sectional results were validated against the analytical multi‑layer conduction solution with a deviation <0.2 %. The study concluded that EACOP’s heated and insulated design is sound, but operational success requires maintaining the inlet temperature above 50 °C, proactive pigging before wax reaches 20 mm, and dynamically adjusting heating power according to soil temperature variations.