Open Journal of Engineering Science (ISSN: 2734-2115)

Journal Information
EISSN : 2734-2115
Published by: African Researchers Magazine (10.52417)
Total articles ≅ 7

Articles in this journal

J. C. Orjiewulu, D. C. Chukwuemeka, C. E. Jesusblessing, A. Ibrahim
Open Journal of Engineering Science (ISSN: 2734-2115), Volume 1, pp 1-19; doi:10.52417/ojes.v1i2.142

Unreliability and interruptions facing power supply are evidence of the excessive heat generated in power systems, as a result of the inefficiency of oil cooling medium employed in distribution transformers. The design and implementation of a prototype automatic temperature control system is to be employed as a method towards solving the above stated problem of excessive temperature rise in distribution transformers. The prototype design consists of a PIC microcontroller programmed in C language, an LM35 temperature sensor, an electric fan and other diverse electronic component. It operates a mechanism that detects temperature rise in the transformer and automatically turns on the cooling fan at extreme temperature conditions. A 16x2 LCD is employed as the medium for temperature display unit of the transformer. The resulting prototype functions in a way that it has the ability to detect every 1ºC rise and reduction in the temperature of the transformer. Thus, at extreme temperature conditions, the automatic temperature control system diminishes the excessive heat generated in the transformer to the appropriate working temperature condition. Orjiewulu, J. C. | Department of Electrical Electronics Engineering, University of Benin, Benin City, Edo State, Nigeria.
T. O. Suoware, S. O. Edelugo, C. O. Amgbari, F. L. Sorgbara
Open Journal of Engineering Science (ISSN: 2734-2115), Volume 1, pp 30-39; doi:10.52417/ojes.v1i2.151

The high yielding of oil pam fibre reinforced composite (OPFC) to fire has necessitated research to improve and develop fire retardants (FR) to mitigate the spread of fire. Researchers relied on Flame Retardants (FR) classified as either halogenated or non-halogenated based FR to improve the performance of composites with emphasis on flammability properties (FP). The main object of this paper is to evaluate the effect of six non-halogenated FR species in OPFC to meet required fire safety standards for building purposes. The six FR species comprising aluminum tri-hydroxide (ATH), ammonium polyphosphate (APP), Gum Arabic powder (GAP) and carbon black (CB) were processed with OPFC at 0, 15 and 18% loading ratio using hand lay-up compression moulding technique. Specimens cut from the OPFC panels were tested for flammability and thermal properties using thermogravimetric analysis (TGA/DSC Metlar Toledo) and cone calorimeter apparatus respectively. The result obtained for thermal analysis shows that the panel was thermally stable at 391.6OC before degradation began compared to those without FR while peak flammability properties obtained for heat released rates, mass loss rates and smoke production rates showed the OPFC panels rapid fire response were significantly reduced respectively by 67.4%, 50.9% and 37.5% compared to those without FR. It can be concluded that the hybrid FR comprising APP-GAP showed a stable char structure during fire and thus prevented the escape of combustible volatiles which reduced the peak FP values of the OPFC panels. These flammability properties could be said to meet required fire safety standards for building applications.
T. O. Suoware, S. O Edelugo, C. O. Amgbari, F. L. Sorgbara
Open Journal of Engineering Science (ISSN: 2734-2115), Volume 1, pp 20-29; doi:10.52417/ojes.v1i2.141

Composite laminates have distinct interface comprising reinforcements from both synthetic or natural sources and polymers which make them favourable in the world of composites due to the intrinsic benefits they possess. Composite laminates from natural sources have shown to be highly susceptible to flame and have been improved by the addition of flame retardants (FR) during processing. The effect of the FR on the mechanical behaviour of these composite laminates is quite unclear and has not been given the in-depth attention. In this paper, the effect of FR of two set of composite laminates on mechanical failure was assessed. The two set of composite laminates comprising oil palm fibre composite (OPFC) and wood sawdust composite (WSC) were processed with polyester resin and six (6) FR using hand-lay compression moulding. The FRs were derived from aluminium tri-hydroxide (ATH), ammonium polyphosphate (APP), gum Arabic powder (GAP) and carbon black (CB) at 12%, 15% and 18% loading ratios. Specimen cut from the composite laminates were tested for failure under tensile and flexural loading using the universal testing machine (UTM). The results obtained shows that the addition of 15%APP-GAP/CB in WSC and 12%APP-GAP in WSC exhibited an outstanding performance in improving tensile and flexural strength of the composite laminates by 154% (from 9.67MPa to 24.56MPa) and 103.4% (from 42.14MPa to 85.7MPa) respectively compared to those without FR while the FR in OPFC did not show any significant improvements. It can be concluded that FR with particulate reinforcement could improve the mechanical behaviour of composite laminates as a suitable reinforcement. Suoware, T. O. | Department of Mechanical Engineering Technology, Federal Polytechnic, Ekowe, Bayelsa State, Nigeria
S. Okotie, A. E. Fasanya
Open Journal of Engineering Science (ISSN: 2734-2115), Volume 1, pp 14-25; doi:10.52417/ojes.v1i1.81

Reservoir fluid properties are very important in reservoir engineering computations such as material balance calculation, well test analysis, reserves estimate and numerical reservoir simulations. Ideally, these properties should be obtained from laboratory pressure-volume-temperature (PVT) analysis. Quite often, however, these measurements are either not available, or very costly to obtain. In such cases, empirically derived correlations are used to estimate the needed properties, all computation therefore, will depend on the accuracy of the correlations used for estimating the fluid properties. Hence in this study, Standing’s correlation for estimating the solution gas-oil ratio was optimized using a particle swarm optimization (PSO) algorithm to minimize the error associated in estimating solution gas-oil ratio from correlation at various depletion pressure. The optimized correlation was taken as a function of bubble point pressure, API gravity, gas gravity and reservoir temperature. PVT data from differential liberation test was used to validate this study’s correlation and the result obtained shows that the optimized correlation for this study matches closely with the experimental values, also the newly optimized correlation was validated with other models and the results gave the least average relative error of 3.34 and a correlation coefficient of 0.998 after 216th successive iterations by the particle swarm optimization algorithm. Okotie, S. | Department of Petroleum Engineering, Federal University of Petroleum Resources (FUPRE), Effurun, Delta State, Nigeria
E. O. Iyasele
Open Journal of Engineering Science (ISSN: 2734-2115), Volume 1, pp 26-52; doi:10.52417/ojes.v1i1.82

Perovskite solar cells (PSCs) though in its development stage, has been of interest to Scientists receiving considerable attention in recent years as a promising material capable of developing high performance photovoltaic devices at low cost. Owing to their solution processability, broad spectrum solar absorption, low non-radiative recombination losses, etc., PSCs provide numerous advantages over most thin film absorber materials. Due to the substantial improvement of Power Conversion Efficiency (PCE) of these materials, photovoltaic efficiency has reached prestigious position (approx. 20.1 %) within the last 5 years. In this review article, we discuss the current state of the Art for photovoltaic devices based on Perovskites, highlighting the underlying phenomenon, synthesis, challenges, comparison to other technologies and future outlook. We emphasized the importance of Perovskite film formation and qualities in achieving highly efficient photovoltaic devices. The flexibility and simplicity of Perovskite fabrication methods allows the use of mesoporous and planar device architectures. A variety of processing techniques are currently employed to form the highest quality CH3NH3PbX3 films resulting to high performance PSC devices which include stoichiometry, thermal annealing, solvent engineering, additives and environmental control. In this review, we outlined and discussed the challenges of PSCs including its stability issues, hysteresis effects, and ion migration effects. Possible ways overcoming these challenges and improvement on the stability of PSCs so far were also addressed. Iyasele, E. O. | Mechanical Engineering Department, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria
J. C. Nnaji
Open Journal of Engineering Science (ISSN: 2734-2115), Volume 1, pp 53-71; doi:10.52417/ojes.v1i1.83

Biodiesel is a renewable, clean-burning, and biodegradable fuel which can be synthesized from readily available domestic and natural sources, such as edible, non-edible and waste cooking oils, which may serve as a substitute to petro-diesel. It is produced by catalytic transesterification of fats and oils. A number of researches has been devoted to discovering a benign catalyst, especially heterogeneous acid catalyst that could convert non-edible and waste cooking oils with high free fatty acid into biodiesel, in an attempt to reduce the cost of production. The cost of production of biodiesel is still far higher than that of conventional petro-diesel, owing to the cost of edible oil currently being used, processes involved, and cost of conventional heterogeneous catalysts employed. This study assessed the role of various catalysts; homogeneous, heterogenous and enzyme-catalyzed transesterification reactions, in terms of their advantages and disadvantages in biodiesel production in order to establish very promising catalysts. Some methods of heterogeneous acid catalysts were also highlighted. Amongst the common heterogeneous catalyst, carbon-based solid acid catalysts were recommended as very promising solid acid catalyst that can utilize the non-edible oils in biodiesel production. The advantages of carbon-based solid acid catalysts include cheap readily available raw materials for their synthesis, easier production processes, relative stability, high reusability and potential for utilizing waste and non-edible oils for biodiesel production. Nnaji, J. C. | Department of Chemistry, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria
S. Okotie, N. O. Ogbarode
Open Journal of Engineering Science (ISSN: 2734-2115), Volume 1, pp 1-13; doi:10.52417/ojes.v1i1.80

To effectively evaluate a gas condensate reservoir performance, the reservoir engineer must have a reasonable amount of knowledge about the reservoir to adequately analyze the reservoir performance and predict future production under various modes of operation. Due to the multiphase flow that exists in the reservoir, characterization of gas condensate reservoirs is often a difficult task with the variation of its overall composition in both space and time during production which complicates well deliverability analysis and the sizing of surface facilities. This study is primarily concern with the evaluation of a gas condensate reservoir performance of Akpet GT 9 Reservoir in the Niger Delta region of Nigeria with material balance analysis tool “MBal” without having to run numerical simulations. The result obtained with MBal on the analysis of Akpet GT 9 reservoir gave 23.934 Bscf of gas initially in place which compares favorably with the volume obtained from volumetric techniques. Results also shows that the most likely aquifer model is the Hurst–Van Everdingen - Dake radial aquifer and the reservoir is supported by a combined drive of water influx and fluid expansion. Okotie, S. | Department of Petroleum Engineering, Federal University of Petroleum Resources (FUPRE), Effurun, Delta State, Nigeria.
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