Modelling the Dynamics of a Hypereutrophication Process in Ruguma Ponds in Rumuosi-Akpor, Nigeria

In this work, Experimental results were monitored for a period of eight months on certain variables parameter in great Ruguma eutrophication site with Fugro International Laboratory to observe the profiles of the simultaneous variations of these parameters with time. Some parameters show the approach or eminence of hypereutrophication. Cox et al (2009) model for recovering from hypereutrophication was modified to accommodate phosphate concentration variation in the great Ruguma hypereutrophication. Numerical values of constraints, initial and boundary conditions were culled in from the works of Cox et al (2009) in solving the system of ODEs modified.From the analysis made on the results obtained, the Great Ruguma Seasonal Ponds may be said to be recovering from hypereutrophication.The findings of this work can be applied in any trophic study especially when it is entering or recovering from hypereutrophication

Curve-Fitting of Bioremediation of Polycyclic Aromatic Hydrocarbons (PAHs) By Co-Composting Using Roost Manure

In this work, ten polluted sites with oil were obtained from Niger Delta, mixed homogenously with compost manure and sent to FUGRO International Laboratory PortHarcourt Nigeria, for bioremediation experiments and analyses. The 4800g sample was divided into twelve (12) equal parts of 400g for bioremediation; 6 parts for the experiments and 6 parts for the control. Particular ringed PAH was isolatedly tested for bioremediation for each of the five ringed PAHs (1 to 5 rings) and the 800g sample was used for respiration test of compost incubation. It was found that the efficiency of bioremediation increased from one to three rings and decreased exponentially for the rest of the rings, showing that bioremediation is not effective for higher ring PAHs. It was also found that bioremediation yields best (optimum) result between two and three ringed PAHs. The respiration of the compost microorganisms improved during incubation by more than two-third i.e 67.7%. The result of this work can be used in bioremediation studies when trying to isolate or choose a particular ringed PAHs for such bioremediation job

Mathematical analysis of interconnected photovoltaic arrays under different shading conditions

A comprehensive mathematical analysis of interconnected photovoltaic arrays under different shading conditions (opacity) and patterns (column, row, diagonal and corner) has been carried out in this work. The equivalent circuit models for the different shading conditions and patterns, and pseudocode algorithm were developed upon which the performance characteristics of the interconnected arrays were analyzed. Five different interconnections were inclusively considered in this work: series-parallel, total-cross-tied (TCT), bridge-linked, ladder and honey-comb interconnection. The emerging analytical results revealed that TCT is most dominant interconnection and shading patterns across the strings (row and diagonal) have detrimental effect on output power, especially when the opacity is one (signifying perfect shading condition) but shading patterns along the string (column or corner shadings) are less severe to power generation. The formation of double peaks sequel to the presence of shadings are inimical to power generated from the interconnected arrays. Moreover, increasing the interconnections enhances the output power and further serves as a means of bypassing current in the event of threats to the modules. Thus, the results obtained provide vital information for smooth operation and maximization of output power in interconnected arrays by avoiding shades on the strings