Climate Change Dynamics and Imperatives for Food Security in Nigeria

Decadal variability in African rainfall is projected from General Circulation Models (GCMs) to continue under elevated greenhouse gas scenarios. Effects on rain intensity, spatio-temporal variability of growing seasons, flooding, drought, and land-use change impose feedbacks at regional-local scales. Yet, empirical knowledge of associated impacts on crop yield is limited; thus, we examined the imperatives for food security in Nigeria. Bivariate correlation and multiple regression suggests impending drought in the northern region where livestock farming is predominant. Relative contributions of climate independent variables in determining crop yield by backward selection procedures with stepwise approach indexed the impacts of annual climate variability by a parameter computed as annual yield minus mean annual yield divided by the standard deviation. Results show Z-distribution approximately 5 to + 5, when 3 indicate impacts significant at 95% confidence levels. In conclusion, we established the interwoven relationship between climatic change and food security

A steepest descent algorithm for the optimal control of a cascaded hydropower system

Optimal power generation along the cascaded Kainji-Jebba hydroelectric power system had been very difficult to achieve. The reservoirs operating heads are being affected by possible variation in impoundments upstream, stochastic factors that are weather-related, availability of the turbo-alternators and power generated at any time. Proposed in this paper, is an algorithm for solving the optimal release of water on the cascaded hydropower system based on steepest descent method. The uniqueness of this work is the conversion of the infinite dimensional control problem to a finite one, the introduction of clever techniques for choosing the steepest descent step size in each iteration and the nonlinear penalty embedded in the procedure. The control algorithm was implemented in an Excel VBA® environment to solve the ormulated Lagrange problem within an accuracy of 0.03%. It is recommended for use in system studies and control design for the optimal power generation in the cascaded hydropower system

Evaluation of Railway Level Crossing Attributes on Accident Causation in Lagos, Nigeria.

Abstract The study examines the contribution of Railway Level Crossing (RLC)physical attributes to accident occurrence using the12 major level crossings within the Lagos metropolis. The 48km single track mainline section under consideration which barely make up 1.1% of the entire narrow gauge track network of the country within a 5 year period contributed about 45% of the total National crossing accidents recorded in Nigeria. The method of investigation involved recording the individual attributes of each RLC such asgates, pedestrian traffic, car traffic light, proximity of signage to crossing, vehicular traffic as dummy variables.The regression analysis  was used to measure their effect on accidents.The result indicates gates, pedestrians and the location of signage had significant impact on accidents occurrence at level crossings within Lagos metropolis. Based on the findings, enhancement of active warning systems among other recommendations was suggested as potent counter measures for RLC accident reduction.Abstrak Penelitian menguji tingkat kontribusi atribut fisik dari perlintasan jalan kereta api terhadap kejadian kecelakaan menggunakan 12 perlintasan utama dalam kota metropolis Lagos. 48 km jalan utama tunggal menjadi pertimbangan yang hampir meningkat 1.1% dari seluruh trek sempit jaringan negara dalam jangka waktu 5 tahun menyumbang sekitar 45% dari total kecelakaan perlintasan secara Nasional di Nigeria. Metode penelitian melibatkan catatan dari masing-masing atribut RLC seperti pintu gerbang, pejalan kaki, lampu lalu lintas mobil, kedekatan tanda penyebarangan, lalu lintas kendaraan sebagai variabel dumi. Analisis regresi digunakan untuk mengukur pengaruh dari atribut terhadap kecelakaan. Hasilnya menunjukkan pintu gerbang, pejalan kaki, dan lokasi tanda perlintasan mempunyai dampak signifikan pada kecelakaan dalam kota metropolis Lagos.Berdasarkan penemuan tersebut, perbaikan dari sistem peringatan aktif disarankan sebagai upaya mengurangi kecelakaan RLC. 

A control model of the operating head dynamics of Jebba hydropower system

Electricity availability in Nigeria has been very poor over the years, underscoring the need for a better approach for managing generating resources. This paper presents the development of a dynamical model of the operating head of Jebba hydroelectric power plants for system studies and control system design. The mathematical model of the plant was developed from flow continuity conditions, some model parameters were obtained from the source while others were estimated from observations and analysis of the measured data. The developed dynamical equation was validated by comparing the response produced with values obtained by measurement. Upon integrating the model equation in Microsoft EXCEL VBA® environment, a deviation of 2% from measured values was observed. Operators can therefore use the model as a decision support system, while control engineers can find the model directly applicable for optimal and robust control system design for the station.Keywords: Control, Dynamical model, Hydropower, Inflow, Operating head