ABSTRACT Energy crisis occasioned by a decline in the availability of fossil fuels and increasing carbon dioxide emissions that are causing global warming has enhanced interest in the development of clean and renewable sources of energy. Solar energy has a great potential of meeting a large fraction of energy needs using photovoltaics. While most PV cells in use today are Silicon-based, cells of other semiconductor materials have been manufactured. Considerable research has been focused in se...
ABSTRACT Phase change materials have been widely used in optical and electronic storage due to rapid and reversible phase transition between amorphous and crystalline states with remarkable resistivity and optical contrasts. More recently these materials have been identified as suitable candidates for phase change random access memory (PCRAM) applications due to their potential for high scalability, low power and fast speed operation. Despite these superior properties and enormous potential, ...
Abstract In this research an n-type CdxZn1-xS and p-type PbS thin films were optimised for solar cell applications employing chemical bath deposition technique. The thin films were prepared using thiourea and nitrates of cadmium, zinc and lead. Deposition of optimised CdxZn1-xS was done by CBD at 820 C and in alkaline conditions while that of PbS was done at room temperature and both films at normal atmospheric pressure utilizing aqueous conditions. This study concentrated on optimising...
ABSTRACT The Energy - Exergy based performance analysis of the Solid Adsorption Solar Refrigerator is presented. The system comprises the collector/generator/adsorber, the condenser and the evaporator. It utilizes activated carbon/methanol as its adsorbent/adsorbate working combination. The exergy performance analysis of this refrigerator involves detailed assessment of all the following sub-processes that make up the refrigeration cycle, which are isosteric heat-up phase, desorption phase, ...
Abstract Effects of liquid holdup on hydrocarbon production in tapered tubing string using Niger Delta fluid properties was undertaken in this work. Oil reservoir fluids flow to the surface as a multicomponent fluid in pipes during production. Multiphase flow occurs due to the density of different phases involved in reservoir fluid and each fluid phase flow at different velocity. In this study, analytically developed equations and existing fluid correlations were used for determination of pr...
ABSTRACT The effect of cooling rate and modification on the microstructure and tensile properties of Al-Si-Mg alloys was carried out. Castings were produced using a stepped pattern that has different section thicknesses. Sand casting technique was used. A thermocouple inserted into the mould cavity recorded the cooling rates for the different sections. The Al5.43%Si3.83%Mg which was melted in the crucible furnace was modified with sodium (Na) and strontium (Sr) in separate cases. The molten ...
ABSTRACT The purpose of this study is to develop an innovative technique for optimized gas lift design for marginal fields of the Niger Delta. This study used well data from mature fields located southwest of the Niger Delta to develop optimized gas lift design techniques using the single point continuous gas lift approach. A total of fifty-nine (59) wells from the fields were selected for preliminary screening as potential gas lift candidates. The screening process involved; reviewing well ...
ABSTRACT The dynamic simulation is one of the key steps in the validation of the design process of the motor drive systems and it is needed for eliminating inadvertent design mistakes and the resulting error in the prototype construction and testing. A quality mathematical model of induction machine based on the dynamic equations and D-Q transformation technique is presented in rotor reference frame and a computer simulation of a 7.5kW three phase induction motor was carried out based on thi...
ABSTRACT In the design of flood control structures, there is need for rainfall intensity estimation for design discharge computation. To make the rainfall intensity values easily available in south-east and south-south Nigeria, this research developed rainfall models. Dimensional and Regression analyses were used to produce models of rainfall intensities. The dimensional models are dimensionally balanced as opposed to the other models which are based on Talbot, Benard and Quotient equations....
ABSTRACT Simplified predictive numerical models have been developed for diffusion rate of crude oil spilled into Niger Delta soils. The proposed model equations were developed using Fourier transformation, and Green’s function. The induction principles as well as the indicial matrix method of dimensional analysis were adopted in determining the functional parameters that could possibly influence their diffusion rates. These mathematical models correctly predict one – dimensional longitud...
ABSTRACT New Biodegradable drilling fluids were developed using Brachystegia eurycoma (achi), Detarium microcarpum (ofo) and Pleurotus (osu). The drilling properties such as yield point, apparent viscosity, low shear rate yield point and fluid loss were determined.The field polymer muds that are currently in use namely; PAC-R and PAC-L were formulated and used as control samples to the new proposed product. Herschel –Buckley model was used to obtain the yield stress. Cutting transport rati...
ABSTRACT In this work, an expert system for energy management in community based microgrid was developed. This was necessitated in a bid to address the inadequate power supply predominant in sub-Saharan African countries, while also addressing the problem of energy wastage that comes from individuals supplying their own energy demands. To achieve this, an architecture for a microgrid network was developed by adopting existing standards in the geographical region of interest. An energy manage...
ABSTRACT This thesis examines the development of a gas propellant rocket motor using cheap local materials. The fabrication of the prototype rocket engine was achieved by using machine tools like the lathe and drilling machines. The internal radius around the nozzle throat area was made without using any special tools for curves. The engine was tested twice and readings or data taken for pressure and temperature. Two thermocouples were damaged because the temperature exceeded their temperatu...
ABSTRACT The development of a Cathodic Protection System for a mild steel pipe using a magnesium anode was investigated. The pipe was externally coated with three layers of polykene tape wrapping and the soil resistivity was determined using the Wenner four pin method; a value of 2177Ωcm was obtained. The design parameters for the developed Cathodic Protection System were: total current of 0.0153mA; current density of 0.01mA/m 2 ; protection current of 0.0153mA; protection voltage of 0.95V...
ABSTRACT A non-weighing lysimeter was designed, fabricated, tested and installed at Arochukwu, Abia State, Nigeria, where the farmers who engage in dry season vegetable production do so with no knowledge of irrigation water requirements. This method tends to either over-irrigation or under-irrigation below the vegetable water requirements. Too much water can leach costly fertilizers to depths below the root zone, where both the water and fertilizer are permanently lost. Too little water caus...