Bukola Olalekan Bolaji

Federal University Oye-Ekiti · Department of Mechanical Engineering

In dealing with productivity within the manufacturing operations, the first focus is efficiency improvement. Efficiency improvement can be operational efficiency or asset efficiency. Asset efficiency is best explained by Overall Equipment Effectiveness (OEE). Equipment efficiency has been one of the major perennial problems of the cocoa processing...

A thermoelectric Refrigerator is a semiconductor-based electronic component that functions as a small heat compressor. This research focused on thermoelectric refrigerators that use forward biasing to improve the Coefficient of Performance. The constant cooling load was used to investigate its performance with special consideration for the fruit us...

In this study, an attempt was made to develop a cooling system with an internal heat exchanger using a mixture of carbon dioxide (CO2) and liquefied petroleum gas (LPG) as refrigerants to help eliminate the global warming potential and other harmful environmental effects caused by conventional refrigerants'. The CO2 and LPG refrigeration experiment...

An overview of thermodynamic energy and exergy analysis is provided in this work with the goal of developing, constructing, and improving a cascade cooling apparatus for extremely low-temperature managing goods and gas-efficient building operations. A review of the classes of cascade systems was carried out, stating the benefits and setbacks. Every...

The research work is focused on the extraction and characterization of the oil and biodiesel obtained from Achee (Blighia sapida) seeds. N-hexane was used as solvent in the extraction of oil from ackee apple seed. The oil was characterized for yield, relative density, free fatty acid value, acid value, iodine value, and saponification value. The va...

This paper presents a workable vapour compression system (VCS) for evaluating the performance of a refrigeration system with an integrated condenser that uses a long-term alternative refrigerant to halocarbon as a heat transfer medium (R600a). India's refrigeration system uses halocarbon refrigerants due to their excellent thermophysical and thermo...

This paper focused on the characterization of oils and biodiesels derived from Ackee apple seeds and African star apple seeds obtained from local markets. The oils from individual seeds and their mixtures at varying ratios were characterised for relative density, free fatty acid, acid, iodine, and saponification, which yielded 0.91 g/cm3, 1.06 mg-K...

Liquefied petroleum gas (LPG), like other hydrocarbon gases, has good thermo-physical and ecological properties, but its high-flammability has limited its direct use in refrigeration applications. Therefore, this paper investigates the thermodynamic performance of low flammable and ecological-save mixtures of LPG and tetrafluoroethane refrigerant i...

Brass Nanofluid is a substance made from synthetic copper and zinc powder. It has outstanding mechanical, electrical, thermal and optical qualities employed in a variety of applications including, solar, touch screen, bison. The nanoparticles used in this study were developed from brass alloy which was locally sourced and machined to the required n...

The global need for blood product safety and availability in emergencies far outstrips supply, thus attracting the attention of both academia and industry for more technological advancement. The paper examined cascade refrigeration system applications for efficient blood plasma management in energy-deficient communities. Fresh animal plasma was uti...

A cascade refrigeration cycle is a multistage refrigeration system for ultra-low freezing application utilizing two stage vapour compression refrigeration system. Many refrigeration applications require low temperature for quick freezing medical items, production of ice, petroleum vapour liquefaction, pharmaceutical products preservation and storag...

Daily life-saving transfusions rely on the usage of blood products in clinical and research settings. With its proteins used for replacement treatment, human blood plasma serves as the main source for a variety of therapeutic transfusions. During the COVID-19 pandemic, plasma-based therapy was one of the treatment modalities used to treat infectiou...

. The research was conducted to enhance and solve the issues associated with low wettability and insufficient bonding between aluminum and silicon carbide that usually associated with stir casting process. The study used magnesium, heat treatment of SiCp and metallic (SiO2) coating on SiCp for improved Al-SiCp wettability in the manufacture of comp...

The use of refrigerants with a global warming potential (GWP) greater than 150 is banned in small and medium-sized refrigerators in accordance with the European F-Gas policy. Therefore, the suitability of retrofitting an existing refrigerator using a low GWP working fluid (R152a), as a replacement for the usual refrigerant (R134a) that is harmful t...

— Hand washing has become a new normal in our society to prevent the spread of COVID-19 and other viruses. As a result of the need to comply with World Health Organization (WHO) guidelines on hand washing to reduce the risk of infection transmission, an automated hand washing system with an installed water recycling device was developed. The integr...

Research on alternative refrigerants has recently drawn increased attention due to the growing public awareness of global warming and the ozone depleting effect. Numerous research organizations have made significant progress in the replacement of refrigerants, looking for a refrigerant substitute in the low temperature cycle (LTC) and high temperat...

The literature revealed that composites developed through stir casting process suffer some limitations such as low wettability and insufficient bonding between the molten Al and SiCp and the formation of aluminium carbide (Al4C3) at the interface which degrades mechanical performances of the composites. To overcome these challenges, this study used...

Poultry birds de-feathering has a daunting challenge. This study aimed at developing a low cost poultry de-feathering machine (DM) that will promote food hygiene; and the safety of operators. The machine consist of a hard plastic drum on which rubber pluckers were fixed and was powered with a 1.5kW electric motor. The DM was developed according to...

In this paper, the mixture of CO2 and LPG is being investigated, and the salient properties of the refrigerants were the main pointer to the development of a mixed refrigerant. Since CO2 offers a much higher volumetric capacity, the problem of the higher working pressure can be overcome by mixing it with a lower pressure refrigerant. LPG on the oth...

Airconditioning and refrigeration systems are electrical appliances that use a huge amount of energy and contribute indirectly to global warming. Also, R410A which was initially developed as a substitute for ozone-depleting refrigerants in the airconditioning systems has been phase-out due to its high global warming potential (GWP) and the resultin...

The urge for a sustainable and non-polluting industry has raised the need for a search for an alternative insulating fluid that could be used in transformers, because of the negative environmental effect of mineral-based insulating fluids. Natural esters from non-edible oil seeds showed to be feasible alternative, unfortunately they possess poor th...

Composite material is made up of at least two distinct materials functioning together to provide material properties that are different and unique to their own, with quality superior than its constituents. Generally, metal matrix composite materials consist of a matrix (bulk material) and a reinforcement of some type, which are combined primarily t...

Some concerns had been expressed over the success rate of the De-feathering machine (DM) in Nigeria. Therefore, it is imperative to evaluate DM in selected poultry farms in Ekiti State, Nigeria, and consider the factors that inhibit their viability. This study seeks to verify the success rate and identify factors that pose challenges to DM and prov...

Mobile robots experience a lot of challenges with path tracking because of the significant problem with DC motor speed control. The particle swarm optimization (PSO) tuned proportional integral derivative (PID) controller is commonly used to control DC motor speed. However, it fails to reach the optimal solution quickly. Therefore, this paper demon...

Improved path planning algorithms should minimize algorithm processing time, increase path smoothness, and shorten path length, all of which will be extremely beneficial for mobile robot traversal in large workspaces. As a result, an improved multi-objective A-star (IMOA-star) algorithm for mobile robot path planning in a large workspace was design...

COVID-19 pandemic lockdown effect is a global phenomenon that affects every sector of the world economy. Therefore, it is necessary to determine the extent to which COVID-19 lockdown impacted on Engineering education output in Nigeria and relate it vis-a-vis the ratio of government owned universities to private universities (PU) that graduated engi...

Some concerns had been expressed over the success rate of E-learning (EL) in the faculty of engineering in Nigeria Universities since the outbreak of COVID-19. Therefore, there is a need to evaluate EL in the faculty of engineering and consider the factors that hinders its effectiveness. This study seeks to verify success rate and identify factors...

The effect of heat transfer medium (HTM) on the environment is associated with ozone layer depletion and global warming. The role of HTM (working fluid) in the heating and air conditioning industries is paramount, which cannot be underestimated. The conventional refrigerant has been predominantly used over decades due to their thermodynamic propert...

Abstract- Farming in Nigeria should grow away from its predominance in subsistence practice into majorly mechanized system of farming which implies moving to another dimension on the implementation processes. Farming has over a long time being subsistence for obvious reasons, the need for efficient health monitoring mechatronics devices in the are...

This paper study the performance evaluation of a refrigeration system that operates on solar energy as alternative source of power to enhance the refrigerating effect, coefficient of performance (COP), preservation of perishable items and short time drug such as vaccine, to remote communities and parts of the urban settlement around the developing...

In this paper, experimental analysis was carried out on a vapour compression system by varying the parallel tube condenser fins spacing under the same atmospheric condition in a selected Refrigeration and Air-conditioning laboratory to examine the performance characteristics of the refrigeration system. The fins spacing were 2, 4 and 6 mm using Liq...

Unconventional biodiesel characterization techniques using thermophysical and transport properties have been receiving increasing attention due to its advantages over fundamental combustion and simulation of heat transfer in solving heat transfer, chemical, and bioenergy characteristics of biodiesel combustion. In this study, the optimum production...

Substituting Hydrofluorocarbons with natural refrigerants in domestic refrigerators will significantly reduce the direct contributions of fluorinated gases to global warming which will be of great environmental benefit. In this study, the performances of dimethyl-ether (RE170) and its azeotropic mixtures (R510A and R511A) in a refrigeration system...

The diminishing accessibility of wood fuel and the danger of desertification and deforestation call for interest in the use of alternative energy sources. Herein, we studied the properties of bio-briquettes produced from Onyeama coal in Nigeria and groundnut shell used as the desulphurizer, while cassava starch was used as binder with Snail shell....

Refrigerants of low global warming potentials (GWPs) of ≤ 150 are required by regulations as working fluids in domestic refrigeration systems. Therefore, this study theoretically investigated the performance of five new refrigerant mixtures (R440A, R441A, R444A, R445A and R451A) with zero ODP and GWPs of less than 150. The results showed that all t...

Unconventional biodiesel characterization techniques using thermophysical and transport properties have been receiving increasing attention due to its advantages over fundamental combustion and simulation of heat transfer in solving heat transfer, chemical, and bioenergy characteristics of biodiesel combustion. In this study, the optimum production...

The research on the production of transformer oil from biodegradable oil is the focus of this work. Biobased transformer oil was produced from calabash seed oil. The oil was extracted from the seed, then was purified using a modified Dijkstra and Opstal purification method. After the produced purified oil was degummed. The oil characteristics obtai...

This paper presents numerical study and analysis of a novel application of a proposed solar chimney system to help solve the problem of ventilation (thermal comfort) and energy management (inadequate power supply) of buildings in the tropics. The main objective of the study is to determine the feasibility of the proposed system vis-à-vis the airflo...

The negative influence of refrigerants on the climate and the immediate environment in terms of their higher global warming potential (GWP) and ozone depletion potential (ODP) has prompted this study. Currently, natural refrigerants are the preferred alternative refrigerants and hydrocarbon is numbered among these natural refrigerants with zero ODP...

This study used Artificial Neural Network (ANN) for the prediction of power required to inflate different tyre sizes and inflation times. ANN is a widely accepted machine learning method that uses past data to predict future trend. An existing database obtained experimentally from a tyre pressure control test rig was optimized using genetic algorit...

This paper presents performance analysis of a domestic refrigeration system using R600a as refrigerant. Investigation was conducted experimentally to select an appropriate refrigerant mass charge for the system and to compute the cooling system performance characteristics under ambient temperature of 29 oC. The choice of the hydrocarbon refrigerant...

Sustainable development turns out to be more and more central in the last few decades, in view of the fact that valiant steps are essential to guarantee the needs of future generations. The use of renewable sources for producing energy plays an important role to achieve sustainable development. There is a need to focus on non-edible oils for biodie...

This paper presents theoretical investigation of the energy-saving potentials of the eco-friendly R430A, R440A and R450A refrigerant mixtures in a domestic refrigerator. The results showed that R440A refrigerant mixture produced the highest coefficient of performance (COP). The COPs obtained for R430A and R440A were 5.57 and 10.70% higher, respecti...

The solution(s) to issues of power availability is a great concern in developing countries, especially in the tropics. The periods of high temperatures and humidity experienced in these countries make the room/living conditions become unsuitable for human comfort. A proposed novel concept of a solar chimney that will produce power while also servin...

Solar energy is the most promising among the available green energy sources and also the remedy to the increasing global warming potential and ozone depletion. This paper presents an experimental evaluation of an adsorption refrigeration system uses solar energy as a source of heat gain to drive the refrigeration system. It consists of a solar coll...

This paper presents the design, construction and performance evaluation of a locally fabricated motorized citrus juice extractor for small and medium scale industry. The fabrication materials for the machine comprises of stainless steel aluminum alloy which is used for the construction of the hopper, compression chamber and collector or receiver. T...

This paper presents the design, construction and performance evaluation of a locally fabricated motorized citrus juice extractor for small and medium scale industry. The fabrication materials for the machine comprises of stainless steel aluminum alloy which is used for the construction of the hopper, compression chamber and collector or receiver. T...

Halocarbon refrigerants have been scheduled for total phase out because they contributed significantly to the two major global environmental problems -ozone layer depletion and global warming. In this study, the performances of the environmentally friendly R510A and R600a in a retrofitted domestic refrigerating system were investigated experimental...

This paper analyses the major noise producing machines, the effects of the noise, its control methods and the extent of the utilisation of these methods by the Nigerian manufacturing companies. Nine companies were chosen as models to represent the overall manufacturing sectors in Nigeria. The noise produced by the various machines and equipment use...

This paper analyses the major noise producing machines, the effects of the noise, its control methods and the extent of the utilisation of these methods by the Nigerian manufacturing companies. Nine companies were chosen as models to represent the overall manufacturing sectors in Nigeria. The noise produced by the various machines and equipment use...

Water absorption kinetics of Ofada and Nerica (L1) paddy grains were investigated by soaking in water at different temperatures in a thermostatically controlled water bath at soaking times ranging from 40 to 180 min. Soaking temperatures were obtained from the gelatinization temperature measured with a Rapid Visco Analyzer (RVA) prior to soaking. D...

The synthetic chlorofluorocarbon (CFC) and hydro-chlorofluorocarbon (HCFC) refrigerants are being phased out due to their high Ozone depletion Potentials (ODPs) and Global Warming Potentials (GWPs). In this study, the effects of sub-cooling on the energy performance of two eco-friendly refrigerants (R435A and R161) with zero ODP and negligible GWP...

Ozone depletion and global warming are presently the most serious global environmental problems and they have led to drastic changes in the refrigeration technology. Therefore, environment-friendly refrigerants have attracted a significant attention. This paper presents the thermodynamic study of non-ozone depleting R429A, R435A and R457A refrigera...

We report the hybridization of ZnO with natural dyes [Laali, Zobo] or synthetic dye [methyl red] forming ZnO – laali, ZnO – zobo and ZnO – methyl red nanocomposites in bright colours. The structural, optical and dye photosensitization influence of the hybrid nanocomposites were studied by X – ray diffraction (XRD), scanning electron microscope (SEM...

Existing water-based engine coolants (WBEC) are produced by adding corrosion inhibitors (CI) and anti-freezing agents (AFA) to de-ionized water. Water is first deionized to remove corrosion factors (CF) before the additives are introduced. This study seeks to determine whether water-extract from fermented ground maize (WEFGM) can be a better altern...

Production of biogas from animal wastes could lessen the problems of energy shortage and indiscriminate animal waste disposal. A study of anaerobic digestion of selected ratios of cattle, swine and poultry wastes was carried out to evaluate their biogas yields. Cattle (C), swine (S), and poultry (P) wastes were mixed in the ratio C:S:P of 1:0:0 (co...

In this paper, the effect of the Lumped Mass Matrices (LMM) on the dynamic response of beams under uniformly distributed moving loads is investigated. The analysis was done by using finite element method. In this study, material properties, throughout the length of the beams under consideration are assumed to be homogeneous. The elements stiffness,...

The design and construction of a refrigerator as a test rig, in investigating the performance of Liquefied Petroleum Gas (LPG), which has zero ozone depleting potential and very low global warming potential, as working fluid in vapour compression refrigerating system as a possible alternative. The design was made with these assumptions:(a) steady s...

Water has so far been regarded as the best cutting fluid but its corrosion-influence on the work piece has necessitated searching for an alternative. Meanwhile, water-extract from fermented ground maize (WEFGM) processed from two (western yellow and kewesoke white) maize varieties have been considered having been previously found to contain corrosi...

The study was undertaken to assess the heat released of briquettes produced from waste paper and groundnut shell admixture in five mixing ratios (90:10; 80:20; 70:30; 60:40; and 50:50). The briquettes were prepared on an existing motorized briquetting machine. The suitability of briquetted fuel as domestic fuel was studied in terms of flame propaga...

In this study, performances of the ozone-friendly hydro-fluorocarbon and hydrocarbon refrigerant mixtures (R413A, R417A and R422A) were investigated theoretically as alternatives to ozone depleting R22 refrigerant. Thermodynamic properties of these refrigerants were analysed using the REFPROP software and the vapour compression refrigeration cycle....

Current energy shortage and environmental issues resulting from the use of fossil fuels have lead to exploitation of renewable energy resources that includes municipal waste and agricultural residues. These residues are available, indigenous and are environmental friendly but some can not be used directly in combustion process due high moisture con...