This paper presents the effects of the several factors that influence lateral-torsional buckling on freestanding circular arches. The studied factors that attribute to the effects of lateral-torsional buckling include cross section type, included angle, slender ratio, imperfection, loading, and boundary conditions. From the reviewed studies, the misrepresentation of these factors to a certain extent may yield inaccurate results. Several studies and design codes have proposed different solutions to account for these factors in designs against lateral-torsional buckling for some structural elements. However, there were no studies reported on the out-of-plane lateral-torsional buckling of fixed circular arches made of structural aluminum channel sections subjected to central concentrated load. Therefore, there is a need for further research on the lateral-torsional buckling real behavior of fixed circular arches of structural aluminum channels.

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Three-dimensional finite element analyses were performed on closed-ended thick-walled cylinders with a radial cross bore under internal pressure. The aim of this study was to determine the behaviour of the hoop stress as well as to establish the optimal Stress Concentration Factors (SCF). Cylinders of thickness ratios of 3.0 down to 1.4 with cross bore size ratios (cross bore to main bore ratio) ranging from 0.1 to 1.0 were studied. The maximum hoop stress was found to increase with the increase in the cross bore size. Amongst the five different circular radial cross bore size ratios studied, the smallest cross bore size ratio of 0.1, gave the lowest hoop stress while the highest stress occurred with a cross bore size of 1.0. Moreover, the lowest SCF occurred in the smallest cross bore size ratio of 0.1 at a thickness ratio of 2.25 with a SCF magnitude of 2.836. This SCF magnitude indicated a reduction of pressure-carrying capacity of 64. 7% in comparison to a similar plain cylinder without a cross bore.

We live in the world that is completely entangled on energy and thus, Humankind can no longer do without it, power. With electricity being the main form of energy today, this has increased the complexity of our life today. In Uganda, electricity generation is mainly through hydropower which put the country in the bottleneck of over dependence on one source of energy. Yet, there are many energy systems out there that country can diversify its electricity generation. Therefore, the need to understand, the level of development and utilization of various energy systems has been the underlying question for this present study. Comprehensive literature survey was conducted from the electronic databases including ScienceDirect, Wiley, Sage, Scopus, Taylor & Francis, and Google Scholar. The publications in form of reports, conference papers, working papers, discussion papers, journal articles, book sections and textbooks were considered in this study. In total, 11 energy systems including human and animal energy, solid biomass (firewood), hydropower, wind, geothermal, solar, nuclear, peat, coal, petroleum, and non-solid biomass (methanol, hydrogen, ethanol, biodiesel, and biogas) are described. The current and the future development and utilization of these energy systems has been described. The challenges with their development and utilization were elaborated and the solution the challenges were presented. The hydropower with River Nile being the main river for large hydropower plant construction is the dominance energy system in Uganda. Nuclear energy will be the salvation for the country’s electric energy supply in the near future. Therefore, Uganda needs to bet big on nuclear energy.

Sisal nanofibres and Rice husks nanoparticles are valuable biodegradable nanofibre materials which are used in many applications around the world. Polymer composites with naanocellulosic fibres as reinforcing materials are widely used due to their high strength to weight ratio and their strong tensile properties. This study focused on the tensile properties of mono and hybrid nanocellulosic polymer composites using both the experimental and the finite element method. The experimental method was used to validate the finite element analysis results. The experimental and numerical results show that the tensile properties of both the mono and the hybrid composites increase up to an optimal point, beyond which they begin to reduce. It was also evident that the hybrid composites had higher tensile properties than the mono composites.