Engineering and Technology

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Evaluation and Improvement of Production Technology in Uganda: Case Studies of Small-Holder Cage Culture in Watershed Reservoirs and as an Alternative Livelihood for Fishers
(National Fisheries Resources Research Institute, 2011) Stutzman Jones, Emily; Molnar, Joseph J.; Atukunda, Gertrude; Walakira, John
Aquaculture development commentary supports the formation of fish farmer associations or producer organizations as avenues for cultivating small- and medium-scale commercial farmers. However, little is known about the types of associations that facilitate commercialization. This research presents four qualitative case studies, based on semi-structured interviews, profiling existing associations of commercial fish farmers in Uganda. We conclude that the umbrella organizations under which local fish farmer associations vertically align themselves have important implications for fish farmer production. Aquaculture-specific umbrella organizations contribute to the success of local member associations more than general umbrella organizations do. Successful fish farmer associations accept government assistance only when it directly improves their fish farm operations. Other farmer groups seemed to wait for direct subsidization. Training fish farmers, providing quality information, cost sharing, and advocating for the aquaculture sector, not donor seeking, are the top priorities in productive fish farmer associations. Part I of this report summarizes the four case studies; Part II summarizes the results of the cage culture trials.
Development of Low-cost Captive Breeding and Hatching Technologies for the African Lungfish (Protopterus aethiopicus and P. amphibius) to Improve Livelihoods, Nutrition, and Income for Vulnerable Communities in Uganda
(Aquaculture Research and Development Center, 2015) Walakira, John; Boyd, Claude; Molnar, Joseph J.
Culturing resilient species in the prevalent variable climate conditions will be beneficial to African aquaculture. Air breathing fish like the African lungfish (Protopterus sp.) will be desirable, but fish farmers lack aquaculture technologies to propagate and manage this fish. This report summarizes experimental results on diversity, breeding, and management of lungfish reared in aquaculture systems. Relatively higher survival and maturity rates were achieved when lungfish is kept in captivity. A novel SNP panel that will guide a comprehensive lungfish-breeding program is partially generated. Hermaphroditism in lungfish is first reported in this investigation study. These results will guide the generation low-cost technologies for propagating and producing cultured African lungfish to improve household nutrition, food security, and income. Consequently, natural stocks will be protected through this intervention.
X-ray diffraction and thermodynamics kinetics of SiB6 under gamma irradiation dose
(Silicon, 2019) Mirzayev, M. N.; Jabarov, S. H.; Asgerov, E. B.; Mehdiyeva, R. N.; Thabethe, T. T.; Biira, S.; Tiep, N. V.
The silicide hexaboride (B6Si) was irradiated with 60Co at room temperature to study the structural changes and weight kinetics. The B6Si samples were irradiated using a gamma source with a dose rate (D) of 0.27 Gy/s. At adsorption dose range of 9.7, 48.5, 97, 145.5 and 194 kGy. The samples were analysed using X-ray diffraction (XRD) and Energy dispersive spectroscopy (EDS) to study the microstructural and composition changes. The XRD results showed the crystalline structure for the sample before and after irradiation (with gamma irradiation dose 9.7, 48.5 and 97 kGy). Amorphization of the sample began at the gamma irradiation dose of 145.5 kGy. Increase in gamma irradiation dose had an inverse effect on the activation energy and had a directly proportional effect on the lattice volume.
Trends and status of women in physics in Uganda
(AIP Publishing LLC, 2019) D’ujanga, Florence M.; Biira, Saphina; Akoba, Rashida
Most women in Uganda with an advanced degree in physics find employment at a university, teaching and conducting research. Very few take jobs in by industry or at government research laboratories. This paper discusses the trends in Uganda in women’s participation in the field of physics and their status. The paper also highlights factors that hinder girls from pursuing the study of physics and describes interventions the government is initiating to alleviate the situation.
Thermodynamics kinetics of boron carbide under gamma irradiation dose
(International Journal of Modern Physics B, 2019) Mirzayev, Matlab; Demir, Ertugrul; Mammadov, Khagani; Mehdiyeva, Ravan; Jabarov, Sakin; Tugrul, A. Beril; Biira, Saphina; Tiep, Nguyen; Thabethe, Thabsile
In this paper, high purity boron carbide samples were irradiated by 60Co gamma radioisotope source (0.27 Gy/s dose rate) with 50, 100, 150 and 200 irradiation hours at room-temperature. The unirradiated and irradiated boron carbide samples were heated from 30 C to 1000 C at a heating rate of 5 C/min under the argon gas atmosphere of ow rate 20 ml/min. Thermogravimetric (TG) and Differential Scanning Calorimetry (DSC) were carried out in order to understand the thermodynamic kinetics of boron carbide samples. The weight kinetics, activation energy and specific heat capacity of the unirradiated and irradiated boron carbide samples were examined in two parts, T 650 C and T 650 C, according to the temperature. The dynamic of quantitative changes in both ranges is different depending on the irradiation time. While the phase transition of unirradiated boron carbide samples occurs at 902 C, this value shifts upto 940 C in irradiated samples depending on the irradiation time. The activation energy of the unirradiated boron carbide samples decreased from 214 to 46 J/mol in the result of 200 h gamma irradiation. The reduction of the activation energy after the irradiation compared to the initial state shows that the dielectric properties of the irradiated boron carbide samples have been improved. After the gamma irradiation, two energy barrier states depending on the absorption dose of samples were formed in the irradiated samples. The rest and second energy barriers occurred in 0.56{0.80 and 0.23{0.36 eV energy intervals, respectively. The existence of two energy levels in the irradiated boron carbide indicates that the point defects are at deep levels, close to the valence band.
Thermal Performance Evaluation of the Funnel Solar Cooker of Different Funnel Lengths Implemented in Nagongera, Uganda
(Tanzania Journal of Science, 2020) Chepkurui, Jonah; Biira, Saphina
The aim of this study was to evaluate the thermal performance of a funnel solar cooker with different funnel lengths. Four funnel solar cookers of varying funnel lengths were constructed at Nagongera, in Tororo District, Uganda from cheap locally available materials. After construction, four blacked cooking pots of the same size filled with 1 kg of water were each placed in a cooker from 09:00 to 17:00 hrs. The temperature of the water in the pots was recorded after every 2 hours. The maximum temperatures of 93 °C, 84 °C, 68 °C and 58 °C for the funnel lengths of 50 cm, 42.6 cm, 32 cm and 23.3 cm, respectively were achieved at 13: 00 hrs for the average solar intensity of 684 W/m2 and ambient temperature of 27.9 °C. Similarly, as the funnel lengths increased from 23.3 cm to 50 cm, the thermal efficiency of the cooker increased from to 29.2% to 33.2% due to increased solar collecting surface. This indicates that the cooking temperature and thermal efficiency depended on the funnel lengths of the cooker and the time of the day. The results obtained were suitable and therefore the funnel solar cooker can be introduced to the community.
The role of ZrCl4 partial pressure on the growth characteristics of chemical vapour deposited ZrC layers
(Ceramics International, 2017) Biira, S.; Crouse, P.L.; Bissett, H.; Hlatshwayo, T.T.; Njoroge, E.G.; Nel, J.T.; Ntsoane, T.P.; Malherbe, J.B.
ZrC layers were deposited in a chemical vapour deposition (CVD) reactor on graphite substrates using a ZrCl4- Ar-CH4-H2 precursor mixture. The deposition was conducted at different ZrCl4 partial pressures at a constant substrate temperature of 1400 °C for 2 h at atmospheric pressure. The deposited ZrC layers were characterised using X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The effect of ZrCl4 partial pressure on the growth rate, microstructure and surface morphology of the deposited layers was studied. The ZrCl4 partial pressure was manipulated by changing the flow rate of the argon carrier gas through the sublimation chamber. The boundary layer thickness decreased as ZrCl4 partial pressures increased due increased argon flows. The increased ZrCl4 partial pressure increased the growth rate of ZrC layers linearly. It was found that the transport process of the source materials was laminar and forced convection flow. The flow process of source materials through the boundary layer to the reacting surface was also illustrated using a model. The average crystallite size increased with ZrCl4 partial pressures, whereas the lattice parameter, lattice strain and dislocation density decreased as ZrCl4 partial pressure increased. The surface morphology of the asdeposited ZrC layers varied with the ZrCl4 partial pressure. The size of crystals grew larger and the cavities surrounding them decreased in number and size as the ZrCl4 partial pressure increased.
Quantification and characterization of cocoa pod husks for electricity generation in Uganda
(Sustainability and Society, 2019) Kilama, George; Lating, Peter O.; Byaruhanga, Joseph; Biira, Saphina
Due to limited coverage, the electricity power supply in Uganda is an obstacle to the country’s economic development. Utility firms in Uganda either lack the financial capacity to expand their grids to isolated rural areas or choose not to do so due to the low return on investment. Therefore, connecting households to minigrids represents an effective solution to providing power to remote/rural areas. This study evaluates the resource and technology of generating electrical energy from cocoa pod husks (CPHs), an agricultural residue/waste, generated in Uganda. The use of agricultural waste for energy generation is the most suitable option for the rural population in Uganda because of the availability of a raw material (biomass) for its production, which is pollutionfree (renewable and clean) and does not have competition for use. The inability to convert these solid wastes into useful products culminates into environmental related challenges, such as landfilling, climate change, pests, and diseases. Therefore, the aim of this study is to quantify the amount of generated CPHs and evaluate its potential for electricity generation in Uganda. Subsequently, we have been looking into the potential of CPHs as a feedstock for a thermochemical conversion process and the feasibility of a direct combustion technology. Results: The amount of CPHs generated in Uganda has been estimated. The physiochemical analysis has shown that the proportion of CPHs in the fresh pods is about 74%, which is nearly the same as in other studies. The dry matter content of CPHs has been found to be on an average of 19%, whereas ash content, moisture content, and the gross caloric value have been recorded to be 12.3%, 12.58%, and 17.5%, respectively. It seems therefore likely that 41.7 GJ of energy might be produced each year from CPHs in Uganda. Conclusion: This study has demonstrated that the CPHs are an important energy source. As there is an increasing trend in cocoa and CPH production in Uganda per year, the electricity production based on CPHs is sustainable and can be upgraded. The use of CPHs for energy conversion is therefore feasible, cost-efficient, and a solution to some environmental challenges.
Overcoming Policy and Practice Fragility and Enhancing Security of Science, Technology and Innovation Educational Achievement for Females in Uganda
(Journal of the National Council for Higher Education, 2022) Okwakol, Mary N.; Suubi Ujeyo, Margaret Stella; Zami Atibuni, Dennis; Saphina, Biira; Waako, Paul
The Sustainable Development Goals 2030 (SDG 4 and 5) provide for the attainment of quality education for all, including women. Africa Agenda 2063, Uganda Vision 2040, the Third National Development Plan (NDP III) similarly all provide unequivocal reiterations on the need for the provision of quality inclusive education that will drive national socio-economic transformation. This is particularly envisioned through a robust science, technology, engineering and mathematics (STEM) education that fosters relevant science, technology and innovation (STI) knowledge, skills, values, attitudes and competences to constitute the epicentre of the transformation. Promoting the achievement of women in equal measure to men in STEM and STI is critical to the socio-economic transformation agenda. However, there exist gaps in the policy framework and the implementation of STEM education that undermine STI educational achievement, especially for women. This conceptual paper is aimed at examining the fragility of legal and policy frameworks for STEM/STI education and the strategies for enhancing STI educational achievement for females in the Ugandan context. We argue that strengthening the policy implementation of gender-responsive STEM/STI education is a precursor of socio-economic transformation of nations and the entire world. The paper adopts a semi-systematic literature review methodology to examine legal and policy documents for strengths, flaws and implementation gaps with the aim of recommending strategies for enhancing STEM/STI educational achievement for females in Uganda.
Optimisation of the synthesis of ZrC coatings in a radio frequency induction-heating chemical vapour deposition system using response surface methodology
(Thin Solid Films, 2017) Biira, S.; Crouse, P. L.; Bissett, H.; Alawada, B. A. B; Hlatshwayo, T. T.; Nel, J. T.; Malherbe, J. B.
A chemical vapour deposition process using radio frequency induction heating operating at atmospheric pressure was developed for the deposition of ZrC coatings. The precursors utilised in this process were zirconium tetrachloride and methane as zirconium and carbon sources respectively, in an excess of hydrogen. Additionally, a stream of argon was used to, first, remove oxygen from the reactor and then to sweep the vapourised ZrCl4 at 300 °C to the reaction chamber. The ZrC coatings were deposited on graphite substrates at substrate temperatures in the range of 1200 °C–1600 °C. The molar ratio of CH4/ZrCl4 was varied from 6.04 to 24.44. Before the start of the deposition process, thermodynamic feasibility analysis for the growth of ZrC at atmospheric pressure was also carried out. Response surface methodology was applied to optimise the process parameters for the deposition of ZrC coatings. A central composite design was used to investigate the effects of temperature and molar ratio of CH4/ZrCl4 on the growth rate, atomic ratio of C/Zr and crystallite size of ZrC coatings. Quadratic statistical models for growth rate and crystallite size were established. The atomic ratio of C/Zr followed a linear trend. It was found that an increase in substrate temperature and CH4/ZrCl4 ratio resulted in increased growth rate of ZrC coatings. The carbon content (and concomitantly the atomic ratio of C/Zr) in the deposited coatings increased with temperature and molar ratio of CH4/ZrCl4. The substrate temperature of 1353.3 °C and the CH4/ZrCl4 molar ratio of 10.41were determined as the optimal condition for growing near-stoichiometry ZrC coatings. The values were 1.03, 6.05 μm/h and 29.8 nm for C/Zr atomic percentage ratio, growth rate and average crystallite size respectively
A Comprehensive Set of Interpolated Climate Data for Alberta
(Alberta Sustainable Resource Development, 2010) Mbogga, Michael; Wang, Tongli; Hansen, Christine; Hamann, Andreas
We present an easily accessible database of interpolated climate data for Alberta that includes monthly, annual, decadal, and 30-year normal climate data for the last 106 years (1901 to 2006), as well as climate change projections for the 21st century from 23 general circulation models. The database builds on the Alberta Climate Model (Alberta Environment 2005) and a set of five future projections that are recommended and widely used by Alberta government agencies (Barrow and Yu 2005). We added 15,000 historical and projected climate surfaces that include variables relevant for biological research and infrastructure planning, such as growing and chilling degree days, heating and cooling degree days, growing season length descriptors, frost free days and extreme minimum temperature. The database can be queried through a provided software package ClimateAB. A representative subset of these climate surfaces has been thoroughly checked against observed weather station data. We report error estimates for historical climate data and discuss the strengths and limitations of this database for use by natural resource managers and researchers.
Model-Based Analysis of Adoption Factors for Software Visualization Tools in Corrective Maintenance
(2010) Sensalire, Mariam; Ogao, Patrick; Telea, Alexandru
Several classification models exist for software visualization (SoftVis) tools. Such models can be used to compare the features provided by several tools to the requirements of a given use case, in the process of selecting optimally fitting tools. However, it is not easy to predict how such models will perform when used to predict the adoption of SoftVis tools at large, especially for tools which were not considered during the model design. Here, we consider an existing classification model that aims to provide generic guidelines for comparing SoftVis tools for corrective maintenance (CM) based of their features perceived as desirable by users. Although this model explicitly captures several such features, it is not evident that tools that fit the model will be found effective by users in practice. This paper tests the above hypothesis by presenting a comparative evaluation of four software visualization (SoftVis) tools used in CM. The tools were selected to fit well the desirable criteria captured by the model under evaluation. Four independent groups of professional software devel- opers participated in the evaluation, each group using a different tool to solve the same CM task on a real-world code base under typical industry conditions. The results show matches between the features described by the model as highly desirable and and those observed in practice to be essential for tool acceptance, e.g. IDE integration, extended search capabilities, multiple views, scalability, and the need for both dynamic and static visualizations; weakly relevant features, e.g. the commercial tool status; and features which do not influence acceptance, e.g. 3D and anima- tion. Besides showing the correlation between the classification model and observed practice, our study further refines the model’s criteria seen as important for industrial acceptance of software visualization tools.
Description of Selected Technologies Generated in the EAAPP Phase I Programme
(Association for Strengthening Agricultural Research in Eastern and Central Africa (ASARECA), 2016) Nampala, Michael Paul
The conceptualization of the Eastern Africa Agricultural Productivity Programme (EAAPP), stemmed from the recognition by New Partnership for Africa Development (NEPAD) that in order for Africa to achieve its Millennium Development Goals of halving hunger and poverty by 2015, there was need for a sustained economic growth of about 6 percent annually for a period of 12 years. For countries in Eastern Africa and indeed the other regions of Africa, that largely depend on agriculture, this meant generating and sustaining growth of the agricultural sector. It also meant identifying sub-sectors that had the greatest potential to drive growth and reduce poverty. That potential lies in commodities that have a large production base and a large and growing demand in the region. NEPAD through its Comprehensive Africa Agriculture Development Programme (CAADP) recommended that African countries should devote at least 2% of their GDP to agricultural research and development (R&D). It also called for greater focus on improving agricultural productivity and increasing the effectiveness of technology generation and dissemination.
Properties of a class of preconditioners for weighted least squares problems
(University of Berg, 1999) Baryamureeba, Venansius; Steihaug, Trond; Zhan, Yin
A sequence of weighted linear least squares problems arises from interior-point methods for linear programming where the changes from one problem to the next are the weights and the right hand side One approach for solving such a weighted linear least squares problem is to apply a preconditioned conjugate gradient method to the normal equations where the preconditioner is based on a low rank correction to the Cholesky factorization of a previous coefficient matrix In this paper, we establish theoretical results for such preconditioners that provide guidelines for the construction of preconditioners of this kind We also present preliminary numerical experiments to validate our theoretical results and to demonstrate the effectiveness of this approach

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