Papers by John Baptist Kirabira
Kajjoba et al., (2025), 2025
Buildings contribute approximately 40% of global energy consumption and 15% of direct CO 2 emissi... more Buildings contribute approximately 40% of global energy consumption and 15% of direct CO 2 emissions from enduse sectors, primarily due to heating and cooling needs, typically met by grid electricity. This study assessed the thermal comfort and its role in enhancing energy efficiency in tropical buildings. This review examines thermal comfort parameters, building materials, and design strategies suited for tropical environments, focusing on factors like air circulation, thermal mass, and sustainable materials. It identifies critical gaps in current building codes and emphasizes the need for integrated approaches that align energy efficiency with occupant comfort. Passive design strategies and renewable energy technologies are explored as innovative solutions to achieve substantial energy savings and improved indoor environments, particularly in low-income housing. The study also addresses socioeconomic barriers to energy-efficient solutions in low-income settings and proposes stakeholder engagement strategies involving government bodies, NGOs, and local communities. This research highlights the critical role of optimizing thermal comfort in achieving energy efficiency in low-income tropical buildings. By focusing on occupant well-being and energy performance, the study provides a pathway for policymakers, architects, and urban planners to advance sustainable, economically viable, and environmentally friendly built environments in tropical regions. The study aligns with SDGs 3, 7, 9, 11, 12, 13, and 17, contributing to environmental sustainability and climate resilience. It promotes health, well-being, and economic benefits for vulnerable populations by integrating technological innovations, sustainable design practices, and effective policy measures, fostering a comprehensive approach to energy efficiency and thermal comfort in low-income tropical buildings. Highlights 1. Tropical buildings lack thermal comfort considerations leading to energy poverty. 2. Passive cooling strategies enhance comfort and reduce building energy demand. 3. The absence of energy codes limits energy efficiency in tropical buildings. 4. Policy should enforce energy codes and promote climate-resilient low-cost homes.
Characterization and treatment effects on Mutaka kaolin for additive in coatings: Mineral composition, thermal and structural modifications
Heliyon, Dec 31, 2023
Hoslundia opposita vahl; a potential source of bioactive compounds with antioxidant and antibiofilm activity for wound healing
BMC complementary medicine and therapies, Jun 17, 2024
The purpose of this study is to examine the relationships of master production scheduling (MPS), ... more The purpose of this study is to examine the relationships of master production scheduling (MPS), total quality management (TQM), blood production (BP) and blood transfusion sustainability in the blood bank sector of Uganda. This study considers MPS as an independent variable and examines its relationship with BTS through TQM and BP. Based on the dynamic capability theory, this study concurrently incorporates and considers TQM and BP as independent and serial mediators. Data was collected from 213 blood bank respondents using a self-administered questionnaire. Random simple sampling was used to draw the sample. SEM approach was used in the study to assess the model. The major findings are positive total effect relationship between MPS and BTS; BP was found to be an independent mediator, TQM was found not to be an independent mediator, and TQM and BP mediated the MPS and BTS relationship serially. The findings suggest that MPS is related to BTS through a serial mediation model with two mediators. Therefore, blood banks in Uganda need to pay attention to develop and maintain a better MPS program so that positive perceptions of blood transfusion can be attained. Future research should investigate the mediating effect of other TQM and BP dimensions in the link between MPS and BTS in other countries.
Water Boiling Test of carbonized briquettes produced from charcoal fines using African Elemi (Canarium schweinfurthii) resin as an organic binder
Biomass Conversion and Biorefinery, Oct 10, 2021
IntechOpen eBooks, Mar 4, 2020
Advanced materials have offered the materials designer a wide range of options in the specificati... more Advanced materials have offered the materials designer a wide range of options in the specification and selection of materials for various applications. Material properties are continually being improved to meet safety and operational standards in line with prevailing technological developments. Modern technological requirements, together with the consumers' demands for systems and machines that are more energy efficient, stronger, light-weight, cost-effective, etc., dictate that the search for new and advanced materials will remain a subject of interest all the time. The difficulty in designing materials for such stringent specifications cannot be overstated, owing to the conflicting nature of these specifications. Aluminium metal matrix composites (AlMMCs) are a class of materials that have proven successful in meeting most of the rigorous specifications in applications where light-weight, high stiffness and moderate strength are the requisite properties. With a variety of reinforcement materials and flexibility in their primary processing, AlMMCs offer great potential for the development of composites with the desired properties for certain applications. In this review, the development, utilisation and future potential of AlMMCs in various industrial and commercial applications is discussed, together with the existing challenges hindering their full market penetration.
Advances in Fiber Materials
Development of products which can be produced from a country's natural resources is very importan... more Development of products which can be produced from a country's natural resources is very important as far as the industrialization of a nation and saving foreign exchange is concerned. Presently, industries in Uganda and the other states in the Lake Victoria region import all refractory-relatedconsumables, as the demand cannot be met locally. Based on the abundance of ceramic raw materials for high temperature applications in the region and the demand for refractories by industries it is pertinent to develop and manufacture firebricks by exploiting the locally available raw materials. This thesis thus, concerns the characterisation of ceramic raw mineral powders from the Lake Victoria region, more particularly, Uganda, with the aim of developing firebrick refractories from the minerals. Two main deposits of kaolin and a ball clay deposit were investigated to assess their potential in the manufacture of refractory bricks. Raw-and processed sample powders were investigated by means of X-ray diffraction (XRD), thermal analysis (DTA-TG) and Scanning Electron Microscopy (SEM). In addition, the chemical composition, particle size distribution, density, and surface area of the powders were determined.
Biomass and Bioenergy, 2011
Carbon dioxide is one of the main compounds pointed as a cause for climate changes, mainly due to... more Carbon dioxide is one of the main compounds pointed as a cause for climate changes, mainly due to the accelerated use of fossil fuels. In order to measure the consumption of the resources that generate carbon dioxide and verify these compounds emissions, quantitative studies aren't sufficient, but it is needed a proportion relation with the environmental impact. Hence, Life cycle analysis (LCA) studies are used to establish parameters to this relation, orientating which is the best way to be followed and also estimating, as close as possible to the reality, the degree of impacts that can be caused. In this paper a biodiesel plant LCA study is realized, using the model described in ISO 14040 groups. Biodiesel is an alternative renewable fuel to the common diesel. Despite been considered a "clean" fuel, its fabrication process involves environmental impacts. This paper quantifies those impacts, from a theoretical biodiesel plant data, and compares them with those generated on the biodiesel production. The conclusions achieved are that the carbon dioxide generated is greater than the consumed during the entire biodiesel life cycle. However, the biodiesel production generates about 174 times less carbon dioxide than the refining to obtain diesel. Besides, both diesel and biodiesel are responsible for Nitrogen oxide emissions (qualitatively) and it is possible estimate that the environmental impact generated by those emissions is similar between these fuels.
Energy Reports, 2024
Ventilation is pivotal in mitigating indoor pollutants and ensuring comfortable Indoor Air Qualit... more Ventilation is pivotal in mitigating indoor pollutants and ensuring comfortable Indoor Air Quality (IAQ) levels globally. The outdoor environment and ventilation mechanisms significantly impact indoor air quality and occupant health. This research investigated the impact of natural ventilation (NV) and outdoor environment (OE) on indoor air quality (AQ) and occupant health (HI) in low-income housing in Kampala City, Uganda. The study followed a mixed methodology approach by employing self-administered questionnaires and statistical modeling using IBM® SPSS® Amos V24 to analyze the relationships between Natural Ventilation (NV), indoor Air Quality (AQ), Outdoor Environment (OE), and occupant health (HI). The research reveals a strong correlation (0.76) between NV and AQ. In contrast, correlations between AQ and OE (0.16) and NV and OE (0.08) are weak. Model comparative fit indices (CFI: 0.984, SRMR: 0.029, RMSEA: 0.053) indicate an excellent fit. Reliability is high with Cronbach's alpha (NV: 0.800, AQ: 0.862, OE: 0.782) and AVE values (NV: 0.832, AQ: 0.869, OE: 0.786). Significant positive relationships were found between NV and AQ and AQ and HI, highlighting the importance of natural ventilation in improving indoor air quality and occupant health. The study supports SDGs 3, 11, and 13, promoting sustainable building practices and promoting health, enhanced living conditions, and lower greenhouse gas emissions.
Characterization and treatment effects on Mutaka kaolin for additive in coatings: Mineral composition, thermal and structural modifications
Heliyon, Dec 31, 2023
Steel Research International, Aug 1, 2006
In the present work, two deposits, one of kaolin and the other of ball clay, located in Uganda we... more In the present work, two deposits, one of kaolin and the other of ball clay, located in Uganda were investigated for the possibility of manufacturing fireclay refractories. Kaolin from the Mutaka deposit was used as the main source of alumina while ball clay from Mukono was the main plasticizer and binder material. The formulated green body was consolidated by wet pressing and fired at 1350°C in a tunnel kiln. Characterization of the sintered articles was done by X-ray diffraction, scanning electron microscopy, and chemical composition (ICP-AES). In addition, technological properties related to thermal conductivity, thermal shock, alkali resistance, water absorption, porosity, shrinkage, permanent linear change, linear thermal expansion, refractoriness under load, and cold crushing strength were determined. The properties of the articles manufactured from these naturally occurring raw minerals reveal that they compare favorably with those of parallel types. Thus, the raw materials can be exploited for industrial production.
Laboratory Benefication And Evaluation of Mutaka Kaolin from the Lake Victoria Region, Uganda
Applied Clay Science, 2010
Laboratory Benefication And Evaluation of Mutaka Kaolin from the Lake Victoria Region, Uganda
International Journal of Scientific & Technology Research, Aug 25, 2017
In this study, the parameters affecting the crystallization of sodium chloride from brine were in... more In this study, the parameters affecting the crystallization of sodium chloride from brine were investigated. Taguchi experimental design method was applied to study the most influential controlling parameters such as feed concentration, mixer speed, heating load, and residence time on the crystallization yield of salt. An L9 (34) orthogonal array experimental design, consisting of four parameters, each with three levels, was employed to examine the effect of the simultaneous variation of these parameters as control factors on the mass yield. Statistical analysis of variance (ANOVA) was also used to determine the relationship between the experimental conditions and salt yield levels. The results from the signal-to-noise (S/N) analysis 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 minutes, 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.
Characterization of Biogas Digestate for Solid Biofuel Production in Uganda
Scientific African, Jul 1, 2021
Abstract In this study, suitability of digestate from anaerobic digestion of cow dung, pig dung, ... more Abstract In this study, suitability of digestate from anaerobic digestion of cow dung, pig dung, and human waste feedstock as a solid fuel for thermal applications was investigated. The digestate was obtained at different retention times from laboratory scale and household digesters and later characterized. Carbonized briquettes were produced from the digestate followed by their physico-chemical characterization and assessment for combustion and mechanical properties. Results of the proximate analysis of the digestate were: moisture content (6.1 to 18.3%), volatile matter (27.9 to 47.7%), ash (15.0 to 48.9%), and fixed carbon (9.1 to 17.1%). The ultimate analysis results for the digestate were: carbon (19.5%), hydrogen (3.3%), oxygen (20.8%), and nitrogen (7.0%). The developed briquettes showed a moisture content, volatile matter, ash, and fixed carbon in the range of 3.7 to 8.9%, 9.9 to 21.5%, 45.6 to 76.4%, and 8.2 to 22.8%, respectively. Their ultimate analysis results were: carbon (21.1%), hydrogen (1.3%), oxygen (1.8%), and nitrogen (1.9%). The briquette combustion properties revealed an ignition time, burning rate, and water boiling time of 5.35 seconds, 0.16 g/min, 31.1 minutes, respectively with higher and lower heating values of 14.87 and 7.88 MJ/kg, respectively. The briquette ash compounds were sodium 1718.5 ppm, potassium 20017.8 ppm, copper 6.12 ppm, cadmium 1.22 ppm, and lead 25.6 ppm. TGA/ DTG analysis indicated high mass loss rates at 105°C and maximum energy release between 600 and 900°C. The mechanical compressive strength was between 19 and 50 MPa, with bulk density between 1.82 and 2.02 g/cm3. Thus, the briquettes from the biogas digestate demonstrate potential for domestic thermal applications in Uganda.
Characterization of brines and evaporites of Lake Katwe, Uganda
Journal of African Earth Sciences, Mar 1, 2014
ABSTRACT Lake Katwe brines and evaporites were investigated to determine their chemical, mineralo... more ABSTRACT Lake Katwe brines and evaporites were investigated to determine their chemical, mineralogical and morphological composition. 30 brine samples and 3 solid salt samples (evaporites) were collected from different locations of the lake deposit. Several analytical techniques were used to determine the chemical composition of the samples including Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES), Inductively Coupled Plasma-Sector Field Mass Spectrometry (ICP-SFMS), ion chromatography, and potentiometric titration. The mineralogical composition and morphology of the evaporites was determined using X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Physical parameters of the lake brines such as density, electrical conductivity, pH, and salinity were also studied. The results show that the lake brines are highly alkaline and rich in Na+, Cl-, CO32-, SO42-, and HCO3- with lesser amounts of K+, Mg2+, Ca2+, Br-, and F- ions. The brines show an intermediate transition between Na-Cl and Na-HCO3 water types. Among the trace metals, the lake brines were found to be enriched in B, I, Sr, Fe, Mo, Ba, and Mn. The solid salts are composed of halite mixed with other salts such as hanksite, burkeite and trona. It was also observed that the composition of the salts varies considerably even within the same grades
Current Journal of Applied Science and Technology, Mar 19, 2019
This work was carried out in collaboration among all authors. Author JDL initiated the idea, desi... more This work was carried out in collaboration among all authors. Author JDL initiated the idea, designed the study and wrote the first draft of the manuscript. Author HK co-initiated the idea, developed it, selected the materials and methods for the study. Author JBK assisted in data analysis as well as giving technical guidance during the study. All authors read and approved the final manuscript.
Numerical modelling of a solar salt pan for improved salt production at Lake Katwe, Uganda
Case Studies in Thermal Engineering, Feb 1, 2023
State of the art paper on development and manufacture of firebrick refractories from locally available alumnia-rich clays in Uganda
State of the art paper on development and manufacture of firebrick refractories from locally avai... more State of the art paper on development and manufacture of firebrick refractories from locally available alumnia-rich clays in Uganda.
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Papers by John Baptist Kirabira