Browsing by Author "Moses Kiwanuka"

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Enhancing properties of unfired clay bricks using palm fronds and palm seeds
(Results in Engineering. Science direct, 2025-02-11) John Bosco Niyomukiza; Karen Cathy Nabitaka; Moses Kiwanuka; Paul Tiboti; Joseph Akampulira
The building industry has been thriving all around the world. With global advancement, particularly in technology, real estate development is evolving with the ongoing adoption of new tactics. The current study investigates the performance of palm fronds and palm seeds in enhancing the properties of unfired clay bricks as construction materials. The methodologies used to attain the study’s objectives were; determining particle size distribution and Atterberg limits of clay soil, efflorescence, compressive strength, water absorption, and fire resistance of bricks, which were used to give the most appropriate percent of palm fronds and palm seeds for robust bricks. The study required experimental research of the materials used and samples made. Using particle size distribution and Atterberg limits, the soil was classified as clayey soil and low to medium plasticity soil. Batching by weight was achieved using a weighing scale and substitution technique to obtain the proportions of contents in samples. Sample 5, which contained 80% clay, and 20% palm fronds, and sample 6, which contained 65% clay, 25% palm seeds, and 10% palm fronds, passed all the tests. Samples 5 and 6, under efflorescence check, confirmed slight responses where 10% of the brick was covered with a skinny deposit of salts. Under compressive strength, samples 5 and 6 recorded 4.23 N/mm2 and 3.85 N/mm2, respectively, which were more significant than the required minimum compressive strength of fired bricks. For water absorption, they attained a moisture content of 18.1% and 16.1%, respectively, which was in the range of 16–20% under second-class bricks. All bricks passed the fire resistance test, which confirmed that they had a reasonable safety factor. In conclusion, mixes of samples 5 and 6 are recommended to produce robust bricks.
Flood analysis and hydraulic competence of drainage structures along Addis Ababa light rail transit
(Journal of Environmental Science and Sustainable Development, 2025-02-11) Moses Kiwanuka; Seleshi Yilma; Joel Webster Mbujje; John Bosco Niyomukiza
The occurrence of flooding events and the associated risks are increasing in the urban areas of most developing countries. Flooding in any circumstance causes major stresses on affected area’s economic, social and environmental regimes. Therefore, the current study presents a flood analysis and hydraulic competence of existing drainage structures on some selected roads of Addis Ababa City, after integration with Addis Ababa Light Rail Transit (AALRT) Drainage Systems. The existing side drains and cross drainage structures located within the study area were inspected and assessed to ascertain different aspects relating to their performance. Different watersheds were delineated. Hydrological analysis was then carried out using Geospatial tools such as ARCGIS, ARCSWAT, and HEC GEOHMS to determine the different watersheds contributing to the flows. The flows were obtained from the rational method for areas less than 0.5 km2 and HEC HMS for areas greater than 0.5 km2. The hydraulic analysis was carried out using HY-8 for the culvert and the Hydraulic toolbox for side drains. It was found from field surveys and measurements that the existing side drain of 900 mm circular pipe could not convey the maximum flow. The existing box culvert, which comprised of one barrel was able to convey the design flow of 29.52 m3/s with a headwater elevation of 2300.94 m. The existing box culvert was sufficient in conveying the designed flow since its headwater elevation was lower than that of the roadway elevation. However, observations like the presence of accumulated silt, debris within most side drains, and an undersized side drain reduced its hydraulic competence. The undersized side drain was redesigned by increasing its diameter to 1200 mm. The study acts as a yardstick for drainage assessment, especially for existing structures, an indicator for identifying the most flood-prone areas along the railway track. It recommended an intermediate cross culvert before Lancha, regular desilting, and putting screens at inlets of side drains and some distance before the entrance of the culverts. Periodic maintenance of the existing drainage structures and widening of the pipe conduits for the side drains to about 1200 mm for easy maintenance is also necessary
Investigation on the potential use of waste paper to produce papercrete bricks
(AIP Conference Proceedings, 2025-02-17) John Bosco Niyomukiza; Bernard Joseph Odeke; David Owori; Paul Tiboti; Moses Kiwanuka; Joel Webster Mbujje
A significant demand has been placed on the building material industry, especially in the last decade due to the increasing population, which causes a chronic shortage of building materials. The current study aims at utilizing waste paper to produce papercrete bricks and study their engineering properties, a step towards sustainable development. Papercrete is rapidly gaining popularity in the building construction industry worldwide because of its environmental friendliness, low-cost and lightweight. The study considered literature and related ideas up to conceptualization and design of the trial ratio used in testing. Trial mixes of paper sludge, sand, and cement at different proportions made papercrete bricks of dimensions 220×110×102 mm. The tests conducted included compressive strength and water absorption. The mixes of paper sludge, sand, and cement in the ratio of 50, 35, and 15%, respectively, gave the best results. The compressive strength increased with the increase in the curing period. The rate at which the papercrete bricks absorbed water reduced as the curing period increased for all the papercrete trial mixes. It was concluded that percentages of paper sludge less than 50% are recommended for non-load bearing walls such as parapet walls and partition walls.
Temporal trends of water quality parameters, heavy metals, microplastics, and emerging organic pollutants in Lake Victoria and its basin: knowns, knowledge gaps, and future directions
(Environmental Nanotechnology, Monitoring & Management, 2025-02-17) Ivan Oyege; Richard Katwesigye; Moses Kiwanuka; Hosea Eridadi Mutanda; John Bosco Niyomukiza; Dafrosa John Kataraihya; Solomon Kica; Moses Egor
The deteriorating water quality and increasing pollution of Lake Victoria, Africa’s most important and world’s second-largest freshwater lake, is threatening the critical resource within East Africa, which has profound ecological and socio-economic significance. This comprehensive review investigates the environmental dynamics of the lake, exploring temporal trends in water quality, heavy metals, microplastics, and emerging organic pollutants in Kenyan, Tanzanian, and Ugandan waters. Assessing the period from January 2000 to December 2022, the analysis integrates research findings from Lake Victoria and its basin. A complex interaction between natural processes and human activity causes fluctuations in the water quality of Lake Victoria. The study reveals substantial variations in key parameters, reflecting the impacts of industrial discharges, agricultural practices, urbanization, and wastewater inputs. Noteworthy among these variations are heavy metal concentrations, with lead consistently surpassing the acceptable levels in Kenyan and Ugandan waters. Zinc concentrations showed varying patterns, and chromium levels in sediments raise concerns by surpassing EPA guidelines in specific locations. The investigation of organic pollutants identified over 170 contaminants, highlighting the dominance of dichlorodiphenyltrichloroethane (DDT) and its derivatives. Microplastics, recognized in the guts of vital fish species and surface water, merge as a growing concern, posing risks to the aquatic ecosystem. This review illuminates the nature of pollutants in Lake Victoria and identifies knowledge gaps in research attention, especially in the northwestern, western, and southwestern lake basins, and the islands of Lake Victoria, overlooked for more than two decades. Scrutinizing existing research, it serves as a compass, pointing towards areas necessitating further investigation and thereby charting future directions in the research community