Papers by Prof Stephen A . Akinlabi (Associate Professor)
E3S Web of Conferences
The massive increase in energy consumption, especially over the past several years, has raised fe... more The massive increase in energy consumption, especially over the past several years, has raised fears that the world’s fuel and other resource reserves would be drained in the coming years. Over the years, low-cost, long-term energy has been viewed as the foundation of any country’s social and economic success. Nonetheless, in recent decades, a bigger section of the population of developing economies has had limited access to inexpensive and sustainable energy, contributing greatly to these countries’ poor economic and social growth. This study was therefore a review of the various sources of energy and their applications.
E3S Web of Conferences
This paper focused on the short review of biopolymer based composite for tissue regeneration. Bio... more This paper focused on the short review of biopolymer based composite for tissue regeneration. Biopolymers have been slowly introduced into medical applications as a result of their ability to be bio-degradable and to be easily made. By selecting the appropriate biopolymer containing the selected additives to facilitate the polymer-filler interaction, composites with the desired properties can be obtained. Interfacial interactions between biopolymers, and thus Nano-fillers, significantly control the mechanical properties of biopolymer composites and these biopolymer composites such as bone, cartilage, vascular implants, and others.
E3S Web of Conferences
Nanoparticles have recently attracted huge attention as an engineering alternative in various fie... more Nanoparticles have recently attracted huge attention as an engineering alternative in various fields. This is not unconnected with its established ability to perform better when used to replace some conventional systems or used as an enhancement for the system. Hence, this study reviewed the viability of nanofluids developed from nanoparticles as a possible replacement for conventional refrigerants available. In this review, focus was placed on refrigerants and refrigeration types, Nanoparticles and Nanofluids, Synthesis, Characterization and properties of Nanoparticles and finally on Nano-refrigerants and their viability. Conclusions were reached based on findings of the review.
Mathematical Modelling of Engineering Problems
Starch-containing foods such as bread, pastries, and cakes are usually baked at a moderately high... more Starch-containing foods such as bread, pastries, and cakes are usually baked at a moderately high temperature in an oven. When these products are later exposed to room temperature, the associated gelatinized starch begins to harden which causes retrogradation and molecular realignment. Due to this circumstance, manufacturers need to have a fairly accurate estimate of products demand in order to determine the precise amount of baking powder and additives for use in their production so as not to incur losses in their business arising from the stale and consequentially unsalable products. This research was therefore focused on selecting the best forecasting model using a prominent confectionery firm in Abeokuta, Ogun State, Nigeria as a case study. The study was based on 24-week operational period sales data collected from the company. The moving average model and the exponential smoothing model were the two forecasting models considered in this research. The data obtained was thoroughly reviewed and the results of the forecasting models were compared. The most effective model was the exponential smoothing model as it produced the lowest mean absolute percentage error on the average of 3.7347 for the cumulative days of sales under review as against the 15.1713 for the moving average model. However, the exponential smoothing model was considered the best forecasting model for minimizing forecasting error in this study.
TECHNOLOGIES AND MATERIALS FOR RENEWABLE ENERGY, ENVIRONMENT AND SUSTAINABILITY: TMREES21Gr
Scientific African
This study investigates the combined effect of the Tungsten Inert Gas (TIG) and Metal Inert Gas (... more This study investigates the combined effect of the Tungsten Inert Gas (TIG) and Metal Inert Gas (MIG) arcs in achieving improved mechanical and microstructural properties compared with the standalone TIG and MIG arcs based on optimum parameters setting for the TIG and MIG welding processes. TIG and MIG Miller welding machines with a maximum capacity of 400 A were used as the combined heat source. The welds produced by the TIG-MIG, TIG and MIG welding processes were characterized via tensile and hardness testing, macrostructural investigations, microstructural analysis, and X-ray diffraction analysis. The results from the characterization show that the TIG-MIG hybrid joint had better tensile strength, yield strength and percentage elongation properties than the standalone MIG and TIG welded joints, respectively. The fractograph of the TIG-MIG joint was characterized with uniform fine dimples showing a more ductile failure characteristic. Macrostructural evaluation revealed that the heat-affected zone of the TIG-MIG hybrid joint was larger than those of the individual TIG and MIG processes. The microstructure of the TIG-MIG joint showed an abundant presence of acicular ferrite with cementite on the boundaries of ferrite grain. Martensite phases diffracted at higher intensity peaks in the TIG weld while iron phases diffracting at high-intensity peaks in the MIG weld, and lastly, the TIG-MIG welded joint showed only iron phases which accounted for its lowest hardness value when compared with standalone MIG and TIG joints.
Attribution-You must give appropriate credit, provide a link to the license, and indicate if chan... more Attribution-You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. o NonCommercial-You may not use the material for commercial purposes. o ShareAlike-If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original. How to cite this thesis Surname, Initial(s). (2012). Title of the thesis or dissertation (Doctoral Thesis / Master's Dissertation). Johannesburg: University of Johannesburg.
Revue des composites et des matériaux avancés, 2021
Parameters optimization has become a gateway to achieving quality welds with improved properties ... more Parameters optimization has become a gateway to achieving quality welds with improved properties desirable for construction and industrial applications. The complex interaction of welding input parameters requires process optimization to achieve optimal responses (s). This study reports the optimization of input parameters for Gas Metal Arc Welding (GMAW) for optimal ultimate tensile strength in AISI 1008 steel joints. Three levels of arc voltage, welding current, and gas flow rate were selected as input parameters, while the targeted output response is the ultimate tensile strength. Taguchi’s method with an L-9 orthogonal matrix was adopted for the process optimization. The MINITAB 17 software was used to analyze the response through analysis of variance and signal-to-noise ratio. The result revealed that the parameter settings for optimal tensile strength for the GMA welding of 6 mm thick AISI 1008 steel joint are arc voltage set at 30 V, current at 180 A, and gas flow rate set at...
Lecture Notes in Mechanical Engineering, 2020
Energy consumption and environmental problems have been the major consideration for comfort syste... more Energy consumption and environmental problems have been the major consideration for comfort systems manufacturers. This research work investigated a varied mass charge of R600a, an eco-friendly refrigerant with a low concentration of 0.4 and 0.6 g/L of CNT nanolubricant concentration in a domestic vapor compression refrigerating system working with pure mineral oil as the base lubricant. The experimental test performance of the system was studied considering pull-down time, COP, power consumption, and cooling capacity. The result showed that CNT nanolubricant had lower evaporator air temperature with higher COP and cooling capacity with a reduction in power consumption compared to R600a in the base lubricant in the system.
International Journal of Scientific & Technology Research, 2019
The suppression of the high risks involved in the Nuclear energy venture tremendously depends on ... more The suppression of the high risks involved in the Nuclear energy venture tremendously depends on the safety culture of all stakeholders. Despite the commendable efforts that have been made towards nuclear security, there are still some significant loopholes which could retard this progress if not addressed. This paper reviews the global effort towards nuclear security and safety; focusing on the activities of International Atomic Energy Agency (IAEA) and of participating Nations as entangled factors to determine the sustainability of a secured and safe nuclear energy future. The authors presented the two possible global nuclear security scenarios in the nearest future; highlighting the nuclear security culture and action plans which could enhance the global nuclear security and prevent the world from the high-risk scenario were proffered. The recommended actions are expected to provide a breakdown insight to what is expected of individual Nuclear Energy countries as an entity to contribute to a strong safety climate in the world of Nuclear Energy.
Professor Akinlabi’s research and her team has focused on the field of advanced and modern manufa... more Professor Akinlabi’s research and her team has focused on the field of advanced and modern manufacturing processes like Laser Additive Manufacturing (AM), in particular laser material processing. Her other research work is focused on laser metal deposition and functionally graded materials of titanium-based alloys and other materials. Some of the studies she has been involved in focus on cladding titanium with titanium carbide for enhanced wear properties, the cladding of titanium alloy biological implants with hydroxyapatite (HAP) for improved osteo-integration, and the cladding of Grade 5 titanium alloy with copper for improved corrosion properties for marine applications. Akinlabi focuses her investigations on the development of advanced metallic coatings on Ti-6Al-4V substrate using additive manufacturing technology for improved surface performance; with targeted applications in the aerospace, automotive, and shipbuilding industries. This work makes a substantial contribution to...
Laser cladding is a material processing method which utilizes the high-power density available fr... more Laser cladding is a material processing method which utilizes the high-power density available from defocused laser beam to melt both metal coatings and a part of the underlying substrate. A theoretical method based on a numerical simulation using experimental results is anticipated as a contribution to the study of laser metal deposition (LMD). The aim of this research is to simulate the temperature distribution at various points during the laser cladding process of Ti-6Al-4V alloy. A 3D model was developed using COMSOL Multiphysics to solve the governing equations of the occurring fluid flows and heat transfers. The model is based on the experimental work of laser deposited Al-Si-Sn coatings on Ti-6Al-4V alloy. The model was developed to obtain insights on the behaviour of laser melted pools subjected to various process parameters. Simulation with 3D model with different values of various significant processing parameters such as laser power, scanning speed and powder feed rate influences the geometry and dynamics of the melt pool, and cooling rates. The melt pool flow, thermal and solidification characteristics had profound effects on the microstructure of the coatings.
E3S Web of Conferences, 2021
ASTM A36 is the most used type of mild steel especially in construction and manufacturing industr... more ASTM A36 is the most used type of mild steel especially in construction and manufacturing industry. Welding process is regularly employed to fix the crack that usually occurs in low carbon mild steel after a long time use especially in construction industry. In this study, the effects of heat treatment on the mechanical properties on mild steel [ASTM A36] lap welded joint were investigated. Seven pieces of 60 mm × 300 mm mild steel bar were used for this research. Five samples were heat treated in an electric muffle furnace and soaked at 6000C for 65 minutes. Two samples were cooled in air and furnace while the remaining three were rapidly quenched in water, spent engine oil and diesel oil each.Hardness and Impact tests specimens were made from the control (as received) sample and the various heat-treated samples. The specimens were joined together using E6361 mild steel arch welding electrode, lap welding joints and Shielded Metal Arc Welding (SMAW). Hardness test and impact test a...
Annals of Dunarea de Jos University of Galati Fascicle XII Welding Equipment and Technology, 2020
Additive manufacturing (AM) is an important manufacturing technology that has changed the way pro... more Additive manufacturing (AM) is an important manufacturing technology that has changed the way products are designed and manufactured. Laser Metal Deposition (LMD), an AM technology, has the capability of producing components using a 3-Dimensional CAD model, through a layer by layer formation process just like any other AM technology. In this study, the influence of the scanning speed on the corrosion property of Titanium alloy-Ti6Al4V using LMD process was investigated. The scanning speed varied between 0.02 m/s and 0.14 m/s while other processing parameters were kept constant. The electrochemical corrosion test was conducted in sodium chloride (NaCl) solution. The result revealed that the corrosion resistance property was found to increase with the scanning speed.
Mathematical Modelling of Engineering Problems, 2020
This present paper focused on the numerical modelling and simulation of the influence of friction... more This present paper focused on the numerical modelling and simulation of the influence of friction and drawing tension while validating it with experimental results for both symmetric and axisymmetric plane deformations in stranded and unstranded wire drawing of pure aluminium. It must be noted that several methods have been deployed in recent years such as empirical, numerical, mathematical, analytical, as well as experimental in analyzing and optimizing forces and stresses in wire drawing and there are no definite solutions yet in solving the numerical complexities involved as a result of enormous number of factors during the wire drawing operation. On this note, modelling and simulation with different cases had been established. In this study, 9.50 mm was drawn into different diameters having 4.4 mm as entry and 1.7 mm as exit with intermediate sizes. It was established in the study that half conical angle must be kept as moderate as possible, it must not be too high or too low. A...
International Journal of Energy for a Clean Environment, 2020
Energy Reports, 2020
The use of graphene nanolubricant to enhance the performance of eco-friendly refrigerant (R600a) ... more The use of graphene nanolubricant to enhance the performance of eco-friendly refrigerant (R600a) in a vapour compression system was investigated. The graphene nanoparticles were dispersed in the base lubricant and prepared for three different samples of graphene nanolubricant concentration of 0.2, 0.4 and 0.6 g/L, the nanolubricant concentrations were investigated in 50, 60 and 70g of R600a refrigerant each. The performances were compared with the base lubricant (mineral oil). The result showed that R600a performed better in graphene nanolubricant compared to the base lubricant in terms of pull-down time, COP, power consumption, cooling capacity. Therefore, graphene nanolubricant can be used as a drop-in replacement for pure mineral oil in the vapour compression system. c
Energy Reports, 2020
Vapour compression refrigerator systems working with R134a are associated with high energy demand... more Vapour compression refrigerator systems working with R134a are associated with high energy demand and environmental problems and refrigerator consumers' prioritise energy consumption in choosing their choice of refrigerator systems. Therefore, this research work investigated R600a in MWCNT-nanolubricant (0.4 g/L and 0.6 g/L) as a drop in replacement for R134a refrigerant in a household refrigerator system with varied mass charge of R600a (50, 60 and 70 g). The refrigerator was instrumented at the inlet and outlet of the refrigerator compressor, condenser, expansion valve and evaporator. Two bourdon type pressure gauges were connected to the compressor inlet and outlet of the system. The results were taken and evaluated and compared with the result obtained through R134a refrigerant in the system. The result showed that R600a perform better in terms of COP, power consumption and cooling capacity compared to R134a in the system with lower evaporator temperature of −11 • C and power consumption of 0.0639 kW and highest COP in the system. Therefore, R6000a/MWCNT-nanolubricant can serve as a drop in replacement for R134a in the household refrigerator. c
Annals of Dunarea de Jos University of Galati Fascicle XII Welding Equipment and Technology, 2019
Additive manufacturing (AM) also known as three dimensional (3D) printing is an important advance... more Additive manufacturing (AM) also known as three dimensional (3D) printing is an important advanced manufacturing method that will change the way machines and consumer good are made. This technology is where the human creativity meets technology. AM allows product to be fabricated from the 3D computer aided design (CAD) model of the part, no matter the complexity, through addition of materials one layer at a time until the building is completed. In this article, the seven classes of AM, the advantages in the additively manufactured products as compared to the existing counterparts are highlighted and some of the research efforts in this technology are presented. Some of the problems and the future research need in this field are also presented.
Procedia Manufacturing, 2019
The quest for the conservation of energy resources and production of energy systems that are more... more The quest for the conservation of energy resources and production of energy systems that are more efficient have introduced the use of nanoparticles in heat transfer fluids. The study investigated the effect of Al2O3 nanoparticles on the working fluids of a vapour compression refrigeration system (VCRS) when used with refrigerant R134a. The nanorefrigerant was used in the vapour compression system without system retrofit. The system's performance analyses were carried out via the freeze capacity tests and energy consumption analysis. The outcome showed that the performance of the Al2O3-dispersed nano-working fluid outperformed that of the conventional working fluid mixture. Specifically, the outcome demonstrated that the system with the nanorefrigerant achieved faster cooling, better performance and improved energy consumption. Thus, using Al2O3 nanoparticles in combination with the working fluids of domestic refrigerators was shown to be feasible. Further to this, based on the performance results, it was necessary to find out the very reason behind the improved thermal performance of the nanoparticle dispersed working fluid. This led to the determination of the thermophysical property of the nanolubricant. The results indicate better thermal conductivity and salinity, implying that the nanolubricant has better heat transfer ability than the base oil (Capella D). In addition to this, the results of the viscosity test showed that the presence of the nanoparticles caused a reduction in the lubricant's viscosity thus portraying a reduction in the energy consumption. However, the pH test results indicate that there may be the need for an improved compressor material selection if the nanorefrigerant will be employed for vapour compression refrigeration purposes in the future.
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Papers by Prof Stephen A . Akinlabi (Associate Professor)