Browsing by Author "Kajjumba, George William"

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    A facile polymerisation of magnetic coal to enhanced phosphate removal from solution
    (Journal of Environmental Management, 2019-10-28) Kajjumba, George William; Aydın, Serdar; Osra, Faisal; Wasswa, Joseph
    Globally, there are increased threats to available freshwater resources due to pollution, climate change, and increased demand from population growth. Phosphorus is one of the essential nutrients required for animal and plant growth. However, when it is released into freshwater resources in excess amounts, it can become a pollutant through eutrophication. This study aimed to enhance the removal of phosphate from water using modified coal. The coal was magnetised by in-situ synthesis using a precipitation technique. To obtain functional groups and mechanical stability, magnetised coal particles were coated with polyaniline, via the polymerisation of aniline to form Magnetised Unburnt Coal Polyaniline (MUC-PANI). The properties of MUC-PANI were investigated using TGA, BET, XRD, Raman spectroscopy, SEM, and FTIR. TGA reviewed MUC-PANI as 58% magnetised coal and 42% polyaniline, while the specific surface area increased from 30.0 to 42.2 m2/g after modification. SEM indicated a cauliflower structure on the surface of MUC-PANI due to the successful polymerisation of polyaniline. The FTIR spectrum showed successful adsorption of phosphate due to the formation of incipient peak at1008 cm−1. The adsorption kinetic data are better fitted to the Elovich model. The Langmuir adsorption capacity of MUC-PANI is 147.1 mg PO43−/g at 25 °C and pH 5.0 (initial concentration 10-200 mg/L, dose 0.8 g/L). MUC-PANI is a cost-efficient compound for removal of phosphate because it is made from readily available coal.
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    Adsorption isotherms and kinetics of vanadium by shale and coal waste
    (Adsorption Science & Technology, 2018-09-26) Kajjumba, George William; Serdar, Aydın; Sinan, Gu¨neysu
    The use of adsorption using nanomaterials has become a very competitive method for removal of hazardous materials from wastewater. With increasing consumption of fossil fuels and development of energy storage systems, the levels of vanadium pollution are expected to increase. Utilizing natural shale and coal waste as adsorbents, batch adsorption, isotherms, and kinetics of vanadium was studied. The adsorption characteristics of shale and coal waste were studied using Fourier Transform Infrared spectroscope and Scanning Electron Microscopy. The effect of pH, the amount of adsorbent, vanadium concentration, temperature, and contact time between adsorbate and adsorbents were also studied to obtain optimum conditions for maximum adsorption of vanadium. The Fourier Transform Infrared results show little distortion in the vibration of bands, and hence the surface properties remain unchanged for both sorbents after adsorption. The adsorption kinetics are best described by pseudo-second order, while Langmuir model fits the adsorption isotherm for both adsorbents. Maximum sorption capacity is 67.57 mg/g for shale while that of coal is 59.88 mg/g at 298 K and pH 3. For both adsorbents, the adsorption process is spontaneous, endothermic, and chemisorption in nature. Both adsorbents can effectively be recycled twice.
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    The Relationship Between Market Environment Dimensions and Availability of Malaria Pills in Uganda
    (Global Advances in Health and Medicine, 2021) Nagitta Oluka, Pross; Mkansi, Marcia; Kajjumba, George William
    This study sought to examine the contribution of relationship building (in terms of collaboration, information sharing and supply chain interdependence) on the availability of malaria treatment pills in public hospitals in Sub-Saharan Africa using data from Uganda. Methods: By means of a cross-sectional survey research design, the study used a questionnaire strategy to collect quantitative data. Out of the 320 questionnaires that were distributed in 40 public hospitals, 283 were answered and returned, which yielded an 88% response rate. Structural equation modelling (SEM) was used to establish the relationship between measured variables and latent constructs. Results: Drawing on the survey results, the confirmatory factor analysist and the Structural Equation Modelling clearly demonstrate that relationship building (in terms of collaboration, information sharing and supply chain interdependence) significantly influences the availability of Artemisinin-based combination therapies in public general hospitals in Uganda. Conclusion: Policy-makers should focus on developing cheaper information technology tools to exchange information regarding stock levels, forecasting, quantification, orders, and dispensing. This study developed a measurement model for an inter-hospital relationship, using relational view theory, and it employs dimensions in terms of information sharing and supply chain interdependence to predict and explain the availability of malaria pills in government hospitals.
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    A structural equation modeling of supply chain strategies for artemisinin-based combination therapies in Ugand
    (Medicine Access, 2021) Nagitta, Oluka Pross; Mkansi, Marcia ,; Nyesiga, Sylvia Desire; Kajjumba, George William
    Malaria is a killer disease in the tropical environment; artemisinin-based combination therapies (ACTs) play a central role in treating malaria. Thus, the supply and presence of ACT drugs in hospitals are a key feature in the fight against malaria. Supply chain management literature has focused on the private sector, and less attention has been paid to the public sector, especially hospitals. Aim: This study uses an interdisciplinary lens in investigating how to boost the supply and distribution of ACTs to save lives in low-income countries, specifically in Uganda. Methodology: The study adopted a quantitative research design using a questionnaire as the data collection instrument. Of the 440-population size, 304 of the sample population participated in the study. The model was estimated using structural equation modeling (SEM) to establish the causal relationship among the variables. Results: From the SEM analysis, all the hypotheses were significant at p<0.05. The availability of ACTs is strongly affected by strategic dimensions (0.612), followed by operation dimensions (0.257); strategic determinants significantly affect operational determinants by a magnitude of 0.599. The indirect influence of the strategic determinants via operational determinants on the availability of ACTs is not significant. Overall, the factors explained 63.9% of the observed variance in the availability of ACTs, and the ACT availability can be predicted as follows: ACT availability=0.612×strategic determinants+0.256×operation determinants. Top management commitment and organizational responsiveness are among the items that positively affect the availability of ACTs. Conclusion: Strategically, hospital management should invest in cheap technology and software to minimize the unavailability of medicines. Our research suggests that strategic and operational determinants should be integrated into the hospitals’ core business and implemented by the top management. The article contributes to theoretical and policy direction in the public sector medicine supply chain, specifically in public hospitals.