Browsing by Author "Uba, Felix"

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    CFD modelling and analysis of the trajectory and behaviour of oil pollutant particles in the ghanaian territorial waters
    (Scientific African, 2020-04-28) Uba, Felix; Fiagbe, Yesuenyeagbe A.K.; Opoku, Richard
    Petroleum activities like production, transportation and storage have placed Ghanaian waters among zones negatively impacted by human activities. These places are occupied by human occupations and its associated risks. Oil pollution in the environment affects biota and degrades human health. Predictive and descriptive tools have made the assessment of this situation possible for water quality management. In addition, these tools help in contingency planning in dealing with potential threats in the environment. In this research, the MOHID hydrodynamic numerical model was used to render forecast capacity for the possibility of finding susceptible areas to spilled oil particles in the Ghanaian waters from human activities around the region. The concept of nesting domains was used to reduce the cost and processing time (i.e. CPU) time, for computation. The hydrodynamics was modelled under three levels and validated with an average deviation of 14.00% and correlation factors above 0.80 from measured results. To locate possible shorelines susceptible to oil particles, random locations and oil exploration sites were used as discharge points for the simulations. In all, about 8 locations were included for the research and they are as follows: (2.9 oE, 4.4oN), (1.7oE, 4.6oN), (0.9oE, 4.9oN), (0.9oE, 4.6oN), (0.3oE, 5.2oN), (0.3oE, 4.6oN), (0.5oE, 5.5oN) and (0.5oE, 4.6oN). In conclusion, it took the oil particles 2 days, 6 hours; 1 day, 17 hours; 3 days; 4 days; 1 day; 4 days, 1 hour; and 22 hours for the first seven locations to get beached at the shore. For particles located at (0.5oE, 5.5oN), they were beached outside the Exclusive Economic Zone (EEZ) of Ghana. The study has revealed that the territorial waters of Ghana acts as beaching sites for oil pollutants independent of the discharge location.
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    Physical and mechanical properties of locally cultivated tomatoes in Sunyani, Ghana
    (Scientific African, 2020-10-28) Uba, Felix; Esandoh, Eric Osei; Zogho, Donatus
    The physical and mechanical properties of tomato fruits are very pertinent and crucial in the design of mechanised equipment for harvesting, cleaning, sorting, grading, storing and packaging for transportation from farms to processing plants or market centres. The concept of physical and mechanical properties can be applied to prevent the degradation of tomato fruits during harvesting and processing. The objective of this research is to establish the physical and mechanical properties of locally cultivated tomatoes (Eva F1 variety) in the Bono Region of Ghana. The 3-Dimensional linear characteristics of the samples obtained from linear measurement lead to the conclusion that Eva F1 is spherical and as a result it can undergo both sliding and rolling motions because of the aspect ratio which is between 77.54 to 95.18 and sphericity values above 83.00. The linear measurements also revealed that handling and sorting devices should have an aperture size between 34 and 77 mm for outlet or inlet dimension for mechanisation. An ELE compression machine was used to determine the firmness of different grades of Eva F1 tomatoes (red and yellow). An average compressive force of 16.88 N was found to cause fracture to the cell wall of a ripe (red) tomato while the yellow grade experienced an average force of 21.77 N. An inclined plane was used to determine the coefficient of friction for two different wooden surfaces (smooth and rough wawa boards). Average coefficient of friction values higher than 0.22 are recommended for mechanised material handling equipment and 0.21 or lower for packing boxes suitable for transportation. The research also showed that the best stage for the transportation of tomato is when they are at the yellow stage with low coefficient of friction and can absorb more energy before rupture.
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    Thermal Performance of Flat Plate Solar Collectors for Humid and Unpredicted Weather using Air Properties and Energy Method
    (International Journal of Technology and Management Research, 2020-12-31) Uba, Felix; Essandoh, Eric Osei; Akolgo, Gilbert Ayine
    Devising technologies to make use of renewable energy such as solar energy is very innovative and progressive since tapping energy from a free source is cost effective in the long-term and totally ecologically friendly. The main aim of solar drying of crops is to preserve them by removing the excess moisture that will cause their deterioration in order to improve their shelf life. Solar drying though found to be a mature, cost-effective and an efficient method of drying especially crops, it has not been widely deployed for crop drying both at the commercial and industrial level in Ghana. The purpose of this research is to produce a solar heat collector for space heating using cheap and available materials and also to demonstrate the importance of incorporating obstacle/fins on plates to improve the efficiency of solar collectors. This study investigates the effect of increased air contact area of various configuration on the efficiency of solar air heaters. Nine different absorber plates (with and without fins) were considered by this research in an experimental study to select the best design that will be suitable for absorbing or providing a high fraction of heat for conditioning humid atmospheric air (lowest relative humidity of the collector air). The best designs of this study had an efficiency between 58% to 72% and maximum absorber temperatures above 80oC, collector air temperature above 70oC and collector air relative humidity below 20% while the worst design had an efficiency between 35% and 50%, collector air temperature bellow 45oC and the lowest collector air relative humidity of 26%. The findings of this research have revealed that increasing the contact area of the air current or circulation and the shapes of the fins attached to flat absorber plates increase their air contact areas and affect the thermal efficiency of the solar collectors. Also, it has revealed that the arrangement of fins contributes positively to the efficiency of solar collectors