http://repository.unn.edu.ng/handle/123456789/464 2026-09-02T19:57:22Z 2026-09-02T19:57:22Z Udom, I. J. Ugwuishiwu, B. O. http://repository.unn.edu.ng/handle/123456789/8548 2019-06-19T12:06:44Z 2013-01-01T00:00:00Z

Economic Benefit of Land Reclamation of Mined Flood Plains for Agricultural Development in Nigeria Udom, I. J.; Ugwuishiwu, B. O. The economic benefit of land reclamation was appraised in a 2-ha floodplain farm by comparing irrigation cost, land preparation charges and vegetable yield before and after reclamation. 99% of the time was saved in land preparation and 25% in irrigation with corresponding reductions of 85% and 50% as cost of land preparation and irrigation, respectively. Vegetable yield also increased by 53% as a result of increase in cropped area, convenient application of cultural operation and optimization of mechanization possibilities. A benefit cost ratio (CBR) of 1.73 was recorded, but when cost of soil replacement was added to the overall cost, the CBR reduced to 0.60, a 65% reduction in the economic benefit of the farm enterprise and a confirmation that neglect Mining operators to reclaim mined lands in conformity with the mineral Act, is negatively affecting farm enterprise returns.

2013-01-01T00:00:00Z Okoro, Ing O. I. Madueme, T. C. http://repository.unn.edu.ng/handle/123456789/7672 2019-03-08T13:18:44Z 2004-01-01T00:00:00Z

Solar Energy: A Necessary Investment in a Developing Economy Okoro, Ing O. I.; Madueme, T. C. Electrical Energy is the pivot of all developmental efforts in both the developed and the developing nations. Due to the fact that sources or conventional means of energy generation arc finite and fast depleting, most industrialized countries have started research on solar energy as a renewable sources or energy. This paper presents the present state of conventional energy generation in a developing economy like Nigeria. The efforts made in solar energy research and utilization arc highlighted. A case is made for a systematic and coordinated financial investment in solar energy research and adaptation to complement the generation from conventional sources.

2004-01-01T00:00:00Z Ogbuka, Cosmas Uchenna Nwosu, Cajethan Abuchi http://repository.unn.edu.ng/handle/123456789/7671 2019-03-08T13:16:14Z 2009-01-01T00:00:00Z

A Generalized Vector Method of Induction Motor Transient and Steady State Analysis. Ogbuka, Cosmas Uchenna; Nwosu, Cajethan Abuchi The qd transformation theory has been used by many authors for the study of both the steady state and the transient behaviors of induction machines. It has, however, been observed that the complexity of the approaches adopted often reduce the ease of comprehension of this concept, especially by young researchers. This paper, therefore, sets out to utilize the elegant vector approach in arriving at the machine models. The steady state and transient behaviors of a sample motor is examined in the synchronously rotating reference, as a case study, and presented in MATLAB/SIMULINK®.

2009-01-01T00:00:00Z Nwosu, Cajethan Abuchi Ogbuka, Cosmas Uchenna http://repository.unn.edu.ng/handle/123456789/7670 2019-03-08T13:15:17Z 2011-01-01T00:00:00Z

Analysis and Verification of the Effects of Active Damping on the Dynamic Performance of a Grid-Side Converter Nwosu, Cajethan Abuchi; Ogbuka, Cosmas Uchenna One of the most important aspects for large scale integration of wind power systems is the fault ride through (FRT) capability with frequency and voltage stabilization. Large voltage sags induce high voltages in the rotor circuit of the DFIG and thus the rotor current rises and could exceed the current capability of the converter switches. Dynamic performances of a grid-side converter (GSC) to grid voltage sags and fault conditions with active damping and without active damping are presented. Under the same control platform, a faster dynamic response is achieved for the DC-link voltage when active damping is considered as against a sluggish and ripple-infested response without active damping. Under fault condition, a 42% decrease in DC-link voltage is realized when active damping is considered. This is against 136% increase in the DC-link voltage that may excite the protective system to disconnect the grid-side converter subsystem from the rest of the network and thus disenable the ride-through capability of the GSC subsystem when active damping is not considered.

2011-01-01T00:00:00Z