Browsing by Author "Eloka-Eboka, Andrew Chukwudum."

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Experimental optimization of nanostructured nickel oxide deposited by spray pyrolysis for solar cells application.
(Research India Publications., 2018) Ukoba, Kingsley Ogheneovo.; Eloka-Eboka, Andrew Chukwudum.; Inambao, Freddie Liswaniso.
Abstract available in PDF file.
Experimental optimization of nanostructured nickel oxide deposited by spray pyrolysis for solar cells application.
(Research India Publications., 2018) Ukoba, Kingsley Ogheneovo.; Inambao, Freddie Liswaniso.; Eloka-Eboka, Andrew Chukwudum.
This study focused on the experimental optimization of nanostructured nickel oxide (NiO) for solar cell applications. The optimization procedure involved the variation of the precursor concentrations of nickel acetate with attendant measurement of the properties of nickel oxide films. The films were spray deposited on glass substrate. Nickel acetate precursor was used at a substrate temperature of 350 oC. Precursor concentrations were: 0.025 M, 0.05 M, 0.075 M and 0.1 M respectively. The surface morphology revealed nanostructured film with particles densely distributed across the substrate’s surface. The films are homogeneous, smooth, well adherent and devoid of pinholes and cracks. The morphology became grainier as the precursor solution increased. Elemental composition exposes the presence of Ni and O elements in NiO film. Oxygen concentration decreases as precursor solution increases. The film structural property reveals that deposited NiO film has an amorphous structure at 0.025 M while the other concentrations are polycrystalline in nature with cubic structure. X-ray diffractometry (XRD) further reveals that the intensity of NiO films increases with increased molarity. Preferred orientation was along the (1 1 1) peak with minor intensity along the (2 0 0) peak. XRD patterns have peak diffraction at (2θ = 37 o and 43 o) for the (1 1 1) and (2 0 0) planes respectively, and 64 o for the (2 2 0) plane for 0.1 M. Crystallite size was obtained at 63.77 nm maximum. Film thickness increased with increasing precursor concentration from 6.277 μm to 11.57 μm. Film micro strain was observed to have compression for all precursor solutions. Optical studies showed that transmittance decreased with increasing concentration from 80 % to 71 %. Optical band gap energy was between 3.94 eV to 3.38 eV as precursor concentration increased, revealing the effect of varied concentrations on NiO film properties. Optimized results obtained are precursors in the development of low cost, efficient, durable solar cell fabrication for developing countries.
Exploring the effectiveness of separation of pith/fibre fractions in sugarcane bagasse briquetting.
(2019) Madlala, Nkosinathi Emmanuel.; Eloka-Eboka, Andrew Chukwudum.; Lokhat, David.
Abstract available in the PDF.
Fabrication of affordable and sustainable solar cells using NiO/TiO2 P-N heterojunction.
(Hindawi., 2018) Ukoba, Kingsley Ogheneovo.; Inambao, Freddie Liswaniso.; Eloka-Eboka, Andrew Chukwudum.
The need for affordable, clean, efficient, and sustainable solar cells informed this study. Metal oxide TiO²/NiO heterojunction solar cells were fabricated using the spray pyrolysis technique. The optoelectronic properties of the heterojunction were determined. The fabricated solar cells exhibit a short-circuit current of 16.8 mA, open-circuit voltage of 350 mV, fill factor of 0.39, and conversion efficiency of 2.30% under 100mW/cm² illumination. This study will help advance the course for the development of low-cost, environmentally friendly, and sustainable solar cell materials from metal oxides.
Influence of concentration on properties of spray deposited nickel oxide films for solar cells.
(Elsevier., 2017) Ukoba, Kingsley Ogheneovo.; Eloka-Eboka, Andrew Chukwudum.; Inambao, Freddie Liswaniso.
Spray pyrolysis technique was used to deposit various concentration of nickel oxide films on glass substrate. The Effect of varying precursor concentration on elemental, morphological and structural properties was investigated on the deposited NiO films. Nickel (II) acetate tetrahydrate precursor was used at substrate temperature of 350 oC. Precursor concentrations were 0.025, 0.05, 0.075 and 0.1 M. Scanning Electron Microscope (SEM) surface morphology revealed nanostructured films with particles densely distributed across substrates surface. Increased in surface grains was observed as the precursor solution increased. Elemental composition of NiO films revealed presence of Ni and O element. There was reduction in oxygen concentration as precursor solution increases. Amorphous structure was observed at concentration of 0.025 M while polycrystalline with cubic structure was observed at higher concentrations. Preferred orientation was along (1 1 1) peak with small intensity along (2 0 0) peak. XRD patterns have peak diffraction at (2θ = 37 o and 43 o) for (1 1 1) and (2 0 0) planes respectively and 64 o for (2 2 0) plane for 0.1 M. Film thickness grew with increase in precursor concentration. Film micro strain was observed to have compression for all precursor solution conspicuously revealing the effect of varied concentration on NiO films properties
Production, evaluation and testing of biodiesel : case studies of Moringa oleifera and selected tropical seed oils.
(2015) Eloka-Eboka, Andrew Chukwudum.; Inambao, Freddie Liswaniso.
Production, evaluation and comparative testing of biodiesel from Moringa oleifera seed oil and selected tropical feedstock oils were undertaken in this study. From studies, Moringa oil has higher oil yields and excellent fuel properties and as a result is a good choice as feedstock to produce biodiesel as well as being an optimizer through the process of hybridisation with other feedstocks, to produce hybrid biodiesel fuels. Production processes were therefore designed to extract oils from the seeds of Moringa, Jatropha, Sandbox tree and Yellow oleander. Transesterification, a biodiesel production process, was deployed using methanol in the presence of NaOH, KOH as catalysts. The use of residual ash from plantain peels as a local catalyst was evaluated as an established production variable. The study also determined production model protocols for transesterification and optimization of production variables (alcohol/oil ratios, reaction temperatures, reaction time and agitation). The hybridization process was developed to improve the quality of biodiesel produced from other feedstocks. Hybridization is the co-mingling of oils of different feedstocks before and after transesterification. This became a major contribution of the study. Hybridisation was carried out using two process pathways termed in situ and ex situ hybridization. Fuel properties of oil feedstocks vary depending on sources and chemo-physical composition and with hybridization, the output is improved and standardized. Oils and biodiesel from the feedstocks were analyzed and their properties determined; namely, chemo-physical, rheological, thermal and gaseous emission properties. The methodologies used and results obtained were evaluated in accordance with ASTM, AOAC, IP and SANS standards. The produced biodiesel and hybrids were further subjected to engine performance tests and analysis using a four strokes diesel engine (TD 302). The observations were simulated and computed, evaluated and analyzed. As new players in the alternative fuel market, the biodiesel potential of these feedstocks is huge as a source of fuel for automobiles and other energy needs. Improved specific fuel properties are: viscosity, specific gravity, refractive index, cetane index, fatty acid composition, free and total glycerides, acid value, peroxide value, oxidative stability, density, flash points, pour points and calorific values.
Review of solar energy inclusion in Africa : a case study of Nigeria.
(2017) Ukoba, Kingsley Ogheneovo.; Eloka-Eboka, Andrew Chukwudum.; Inambao, Freddie Liswaniso.
This work reviews solar energy inclusion in Africa using Nigeria as a case study. It reviewed studies made on viability, challenges and solutions associated with making solar energy a viable energy option in Nigeria. The study highlighted data on current industry capacity of solar energy, installed PV capacity, and solar energy application distribution. It sheds light on solar energy initiatives and projects in Nigeria and solar energy capacity development in Nigeria. Success stories of solar energy and solar cell fabrication in Nigeria are presented. Existing government policies and legislation are discussed. The authors consider the challenges faced and the current and future prospects of solar power in Nigeria, and make recommendations regarding the speedy and seamless inclusion of solar energy in Nigeria and Africa as a whole.