Browsing by Author "Dankwah, Joseph"

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    Concentration of some heavy metals (Cu, Zn, Cd, Hg, As) in the water and sediment of lake Tadee at Ashanti Mampong in Ashanti Region of Ghana
    (2011-06-20) Dankwah, Joseph
    The aim of this research was to assess the water quality of Lake Tadee with respect to heavy metals pollution. The water and sediment samples were collected from Lake Tadee at Ashanti Mampong in the Ashanti Region of Ghana during October, 2010 and February, 2011. The water and sediment samples were analyzed for Zn, Cu, Cd, Hg and As, using Instrumental Neutron Activation Analysis (INAA). The results of this study showed that there were significant differences in concentrations of the metals in the surface water and bottom sediment of Lake Tadee except mercury in which there was insignificant different. The higher concentrations of heavy metals in the sediment of the Lake Tadee than its overlying water may be due to factors such as changes in temperature, pH, sediment matrix, and redox condition as well as effluent from domestic, municipal and agricultural waste might have contributed to the release of higher contaminants in the bottom of the sediment. The mean concentration of heavy metals (mg/L) in the water ranged from 0.066 to 0.174 for zinc, 0.021 to 0.036 for copper, less than 0.001 to 0.015 for cadmium, and those mercury and arsenic were below detection limits. The concentration (mg/Kg) of the heavy metals in the sediment ranged from 8.683 to 10.041 for zinc, 8.560 to 10.072 for copper, 0.036 to 0.096 for cadmium, 0.553 to 0.658 for arsenic, and that of mercury was below detection limit. Heavy metals concentration in the Lake Tadee was significantly higher than that of Kyiremfa. However, Concentrations of heavy metals in the two water bodies are currently within acceptable limits of USEPA and WHO recommended guidelines. Care must be taken to reduce the amount of pollutants released into the Lake to prevent future increase in heavy metals concentration in the Lake so that its concentrations would not exceed the national and international standards.
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    Optimal production scheduling, case study: Guiness Ghana Brewery limited, Kumasi
    (2011) Dankwah, Joseph
    As Production systems expand, there is a tendency for the scheduling activities to become complex, or at least more demanding with respect to the time required for their performance Previous production scheduling involves complicated iterative procedures. A new approach brings out the basic principle involved and leads to a simple solution. Production of a given commodity is to be scheduled for a regular and capacity to meet known future requirements while minimizing total production and inventory costs. For the objective function, I intend to find the optimum production schedule by minimizing the total production and inventory cost calculated through the production schedules of orders. The Northwest Corner Rule, the Least Cost Method, and the Vogel’s Approximation Method (VAM) were used to obtain an initial basic feasible solution (bfs). Improving solution to optimality was carried out using The Modified Distribution Method (MODI). The production was modelled as a balanced transportation problem and solved using an excel solver to obtain the optimal production schedule and the results reported. Results from the analysis indicated that the company need not carry out overtime production throughout the year but should apply scheduling to their production activities to ensure cost reduction, optimum utilization of capacity, proper inventory control management, overall quality output and above all optimality.