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Hybrid neurofuzzy wind power forecast and wind turbine location for embedded generation

  • Authors: Adedeji, Paul A. , Akinlabi, Stephen A. , Madushele, Nkosinathi , Olatunji, Obafemi O.
  • Date: 2020
  • Subjects: ANFIS , Embedded generation genetic algorithm , Genetic algorithm
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/436546 , uj:37871
  • Description: Abstract: , Wind energy uptake in South Africa is significantly increasing both at the micro‐ and macro‐level and the possibility of embedded generation cannot be undermined considering the state of electricity supply in the country. This study identifies a wind hotspot site in the Eastern Cape province, performs an in silico deployment of three utility‐scale wind turbines of 60 m hub height each from different manufacturers, develops machine learning models to forecast very short‐term power production of the three wind turbine generators (WTG) and investigates the feasibility of embedded generation for a potential livestock industry in the area. Windographer software was used to characterize and simulate the net output power from these turbines using the wind speed of the potential site. Two hybrid models of adaptive neurofuzzy inference system (ANFIS) comprising genetic algorithm and particle swarm optimization (PSO) each for a turbine were developed to forecast very short‐term power output. The feasibility of embedded generation for typical medium‐scale agricultural industry was investigated using a weighted Weber facility location model. The analytical hierarchical process (AHP) was used for weight determination. From our findings, the WTG‐1 was selected based on its error performance metrics (root mean square error of 0.180, mean absolute SD of 0.091 and coefficient of determination of 0.914 and CT = 702.3 seconds) in the optimal model (PSO‐ANFIS). Criteria were ranked based on their order of significance to the agricultural industry as proximity to water supply, labour availability, power supply and road network. Also, as a proof of concept, the optimal location of the industrial facility relative to other criteria was X = 19.24 m, Y = 47.11 m. This study reveals the significance of resource forecasting and feasibility of embedded generation, thus improving the quality of preliminary resource assessment and facility location among site developers.
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Neuro-fuzzy resource forecast in site suitability assessment for wind and solar energy: a mini review

  • Authors: Adedeji, Paul A. , Akinlabi, Stephen A. , Madushele, Nkosinathi , Olatunji, Obafemi O.
  • Date: 2020
  • Subjects: ANFIS-based modeling , GIS , MCDM
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/436562 , uj:37873 , Adedeji, P.A. 2020:Neuro-fuzzy resource forecast in site suitability assessment for wind and solar energy: a mini review. DOI: https://doi.org/10.1016/j.jclepro.2020.122104
  • Description: Abstract: , Site suitability problems in renewable energy studies have taken a new turn since the advent of geographical information system (GIS). GIS has been used for site suitability analysis for renewable energy due to its prowess in processing and analyzing attributes with geospatial components. Multi-criteria decision making (MCDM) tools are further used for criteria ranking in the order of influence on the study. Upon location of most appropriate sites, the need for intelligent resource forecast to aid in strategic and operational planning becomes necessary if viability of the investment will be enhanced and resource variability will be better understood. One of such intelligent models is the adaptive neuro-fuzzy inference system (ANFIS) and its variants. This study presents a mini-review of GIS-based MCDM facility location problems in wind and solar resource site suitability analysis and resource forecast using ANFIS-based models. We further present a framework for the integration of the two concepts in wind and solar energy studies. Various MCDM techniques for decision making with their strengths and weaknesses were presented. Country specific studies which apply GIS-based method in site suitability were presented with criteria considered. Similarly, country-specific studies in ANFIS-based resource forecasts for wind and solar energy were also presented. From our findings, there has been no technically valid range of values for spatial criteria and the analytical hierarchical process (AHP) has been commonly used for criteria ranking leaving other techniques less explored. Also, hybrid ANFIS models are more effective compared to standalone ANFIS models in resource forecast, and ANFIS optimized with population-based models has been mostly used. Finally, we present a roadmap for integrating GIS-MCDM site suitability studies with ANFIS-based modeling for improved strategic and operational planning.
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Prediction of municipal solid waste generation : an investigation of the effect of clustering techniques and parameters on ANFIS model performance

  • Authors: Adeleke, Oluwatobi , Akinlabi, Stephen A. , Jen, Tien-Chien , Dunmade, Israel
  • Date: 2020
  • Subjects: Waste generation , Adaptive Neuro-Fuzzy Inference System , Clustering-techniques
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/461246 , uj:41074 , Citation: Adeleke, O. et al. 2020. Prediction of municipal solid waste generation : an investigation of the effect of clustering techniques and parameters on ANFIS model performance.
  • Description: Abstract: The present waste management system and facilities in most developing countries are insufficient to combat the challenge of increasing rate of solid waste generation. To achieve success in sustainable solid waste management, planning plays a crucial role. Accurate prediction of waste quantities generated will immensely help to overcome the challenge of deficient-planning of sustainable waste management. This challenge has necessitated the need for modelling approach. In modelling the complexity within a system, a paradigm-shift from classical-model to artificial intelligent model has been necessitated. Previous researches which used Adaptive Neuro-Fuzzy Inference System (ANFIS) for waste generation forecast did not investigate the effect of clustering-techniques and parameters on the performance of the model despite its significance in achieving accurate prediction. This study therefore investigates the impact of the parameters of three clustering-technique namely: Fuzzy c-means (FCM), Grid-Partitioning (GP) and Subtractive-Clustering (SC) on the performance of the ANFIS model in predicting waste generation using South Africa as a case study. Socio-economic and demographic provincial-data for the period 2008-2016 were used as input-variables and provincial waste quantities as output-variable. ANFIS model clustered with GP using triangular input membership-function (tri-MF) and a linear type output membership-function (ANFIS-GP1) is the optimal model with Mean Absolute Percentage Error (MAPE), Mean Absolute Deviation (MAD), Root Mean Square Error (RMSE) and Correlation Co-efficient (R2) values of 12.6727, 0.6940, 1.2372 and 0.9392 respectively. Based on the result in this study, ANFIS-GP with a triangular membership-function is recommended for modelling waste generation. The tool presented in this study can be utilized for the national repository of waste generation data by the South Africa Waste Information Centre (SAWIC) in South Africa and it is also applicable to waste-planners in developing countries for reliable and accurate prediction of annual waste generation.
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Data showing the effects of disc milling time on the composition and morphological transformation of (aþb) titanium alloy (Tie6Ale2Sne2Moe2Cre2Zr-0.25Si) grade

Effect of punch stroke on deformation during sheet forming through finite element

  • Authors: Akinlabi, Stephen A. , Akinlabi, Esther Titilayo
  • Date: 2017
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/243839 , uj:25207 , Citation: Akinlabi, S. & Akinlabi, E.T. 2017. Effect of punch stroke on deformation during sheet forming through finite element.
  • Description: Abstract: Forming is one of the traditional methods of making shapes, bends and curvature in metallic components during a fabrication process. Mechanical forming, in particular, employs the use of a punch, which is pressed against the sheet material to be deformed into a die by the application of an external force. This study reports on the finite element analysis of the effects of punch stroke on the resulting sheet deformation, which is directly a function of the structural integrity of the formed components for possible application in the automotive industry. The results show that punch stroke is directly proportional to the resulting bend angle of the formed components. It was further revealed that the developed plastic strain increases as the punch stroke increases.
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The influence of scanning speed on laser metal deposition of Ti/TiC powders

  • Authors: Sobiyi, K. K. , Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
  • Date: 2017
  • Subjects: Titanium , Lasers , Metal deposition
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/241302 , uj:24840 , Citation: Sobiyi, K.K. 2017. The influence of scanning speed on laser metal deposition of Ti/TiC powders.
  • Description: Abstract: This paper describes the experimental work performed on laser metal deposition (LMD) of titanium carbide powders on pure titanium substrate. The understanding the effect of LMD processing parameters is vital in controlling the properties of the final product fabricated from the LMD process. The objective of the study is to characterize the influence of laser scanning speed of metal deposition of titanium and titanium carbide powders on pure titanium substrate. Microstructural characterization results showed that the substrate is characterized by two-phase morphology; alpha and beta phase. Deposit zone microstructures showed that the grains are of continuous columnar in nature. Heat affected zone region grain areas appear to decrease with increasing in scanning speed for different samples at different scanning speeds. The height of samples at different scanning was observed to decrease with increase in scanning speed. Microhardness results showed that the hardness of the deposits is greater than the hardness of the substrate. Wear resistance performance results showed that the coefficient of friction of substrate is greater than the coefficient of friction of the deposit samples. Wear volume loss of material of the substrate is higher than the deposits. The deposit contains titanium carbide and, as such, this powder has improved the wear resistance performance of the substrate.
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Advanced coating: laser metal deposition of aluminium powder on titanium substrate

  • Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
  • Date: 2016
  • Subjects: Heat affected zone , Laser metal deposition , Powder metallurgy
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/93266 , uj:20325 , Citation: Akinlabi, E.T. & Akinlabi, S.A. 2016. Advanced coating: laser metal deposition of aluminium powder on titanium substrate.
  • Description: Abstract: Laser Metal Deposition (LMD) is an additive manufacturing technique, which can be used to produce solid components from a Computer Aided Design (CAD) model. The LMD process makes use of feeding powder, which is supported by the shielding gas, into the melt pool that is produced by sharply focused collimated laser beam on the substrate. This study employs aluminium powder in its molten state on titanium substrate through the LMD process. The aluminium powder was deposited at varying laser scanning speeds while the laser power and gas flow rate were kept constant. The presence of alpha phase grains were observed in the microstructures of samples at a lower scanning speed and the beta phase grains at a higher laser scanning speed. It was found that the geometrical properties of the deposits, that is; the width, height and the Heat Affected Zone (HAZ) of each sample decreased as the scan speed increases resulting from the laser-material interaction. The microhardness and the corrosion rates of each sample increased as the laser scanning speed increases.
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Comparison of quality infrastructure of the Republic of South Africa and Sweden

Effect of rotational speed on joint inegrity of friction stir lap welded aluminium

  • Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
  • Date: 2016
  • Subjects: Friction stir welding , Aluminum , Rotational speed
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/93262 , uj:20326 , Citation: Akinlabi, E.T. & Akinlabi, S.A. 2016. Effect of rotational speed on joint inegrity of friction stir lap welded aluminium.
  • Description: Abstract: Friction stir welding is a newly developed solid state welding process, which was developed by The Welding Institute in the year 1991. The development of FSW has allowed the process to be used in different applications for different industries, which include aerospace and automobile industry. Due to the increase in the demand of high strength and low weight components in different manufacturing applications, there is a need for using pure aluminium and its alloys in lap configuration. Research studies are required to characterize and obtain optimum process parameters, which can be used to produce good quality lap welds. This paper reports lap welded 1050 Aluminium Alloy using friction stir welding process and established the effect of rotational speed on the joint integrity of the welds. The welds were produced by varying the rotational speed in the range of 1200 and 2000 rpm, and maintaining the traverse speed constant at 150 mm/min. The welds were characterized through microstructural evaluation, microhardness profiling and tensile testing in order to determine the joint integrity of the welds. The results from the macrograph of the welded joints, show a basin shaped nugget resulting from the stirring of the tool during the welding process. Fine and equiaxed grains characterized the microstructure in the stirred zone, which was a result of a dynamic recrystallization. The tensile test data revealed that as the tool rotational speed was increased, the fracture strength also increases, the highest value of the fracture strength was 195 N/mm and was found on the welds produced at 2000 rpm. High Vickers microhardness values were measured at the nugget zone with the highest value found to be 31.88 HV. It was revealed that the welds produced at the rotational speed of 2000 rpm exhibited the optimum welding parameters to join 1050 Aluminium Alloy.
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Evaluating operational challenges of road freight system

Evaluating operational efficiency of rail freight volumes

  • Authors: Madubanya, Julliet , Akinlabi, Stephen A. , Mbohwa, Charles
  • Date: 2016
  • Subjects: Operational efficiency , Freight volumes
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/215037 , uj:21356 , Citation: Madubanya, J., Akinlabi, S & Mbohwa, C. 2016. Evaluating operational efficiency of rail freight volumes.
  • Description: Abstract: South African roads are congested with trucks on every highway in the country leading to traffic congestion, damaged roads and pollution. Railway transportation can assist in eliminating or reducing these problems occurring on our roads. Rail traffic is decreasing because of the operational inefficiencies and this make customers unhappy and taking their business to road transportation. This paper is about how freight volumes are lost from rail to road organizations. This was conducted by looking at the operational inefficiencies experienced at both rail and road organizations. Any organization has its own plan or strategy on how to satisfy the customer and reach its target, but it is the service that they render to their customers that will determine if the organization will reach its target and at the same time satisfy the customer.
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Evaluation of structural integrity of laser formed steel sheets for possible load bearing applications

  • Authors: Akinlabi, Stephen A. , Shukla, M.
  • Date: 2016
  • Subjects: Structural integrity , Laser forming , Microstructural evolution
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/215436 , uj:21417 , Citation: Akinlabi, S.A & Shukla, M. 2016. Evaluation of structural integrity of laser formed steel sheets for possible load bearing applications.
  • Description: Abstract: Steel is a well-known material for various manufacturing applications because of its unique properties such as great formability and durability, good tensile and yield strength and good thermal conductivity. This paper reports on the evaluation of the structural integrity of laser formed steel sheets for possible load carrying applications. The tensile tests conducted revealed 46% elongation while the yield strength of the laser formed components were enhanced with about 18%. Furthermore, elongated grain structures were observed in the micrographs of the three components formed at the maximum parameter setting. It was revealed that this elongation varied indirectly to the applied line energy. The measured grain sizes further showed that the components formed at the optimized maximum process parameter window were characterized by smaller grain structures with about 60% of the grain sizes of the parent material. A progressive increase in the micro Vickers hardness of about 40% was also observed in the three laser formed components in comparison to the parent material. The analysis of the residual stresses conducted in this study revealed that the changes in the residual stresses are a function of the process condition to which the samples were subjected...
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Inspection of market products : a case study

Methods of improving turnaround time of iron ore wagon utilisation

Mitigating backdrop in operational efficiency : a case study

  • Authors: Akinlabi, Stephen A. , Mbohwa, Charles
  • Date: 2016
  • Subjects: Planning , Scheduling , Rail freight
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/215025 , uj:21355 , Citation: Akinlabi, S.A & Mbohwa, C. 2016. Mitigating backdrop in operational efficiency : a case study.
  • Description: Abstract: The main focus of this investigation was to identify the backdrop in the operational efficiency of a rail company in South Africa - Transnet Freight Railways (TFR) and profer solutions. Qualitative approach was adopted through the administering of questionnaires to respondents in Transnet company. Even though Transnet makes effort to resolve the problems, the outcome of the results still show that the system of schedling is not consistent to a specifc standard and the turnaround time is still between poor and fair. In addition, wagon and locomotives failures is identified as one of the factors contributing to the backdrop in the operational efficiency of the TFR system. It is therefore recommended that adopting a good maintenenace system to the wagon and locomotive may help to reduce if not eliminate failures of the wagons and the locomotive. This will consequently help to improve the backdrop in the operational efficiency of the TFR system.
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Powder flow rate influence on laser metal deposited tic on ti-6al-4v

  • Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
  • Date: 2016
  • Subjects: Powder flow rate , Tic , Ti-6al-4v
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/93277 , uj:20328 , Citation: Akinlabi, E.T. & Akinlabi, S.A. 2016. Powder flow rate influence on laser metal deposited tic on ti-6al-4v.
  • Description: Abstract: Laser metal deposition (LMD) presents a suitable substitute for conventional machining of titanium products. It is an additive manufacturing technology used to build prototypes, models, tools, dies and end products. The process is used to manufacture components from materials, which are difficult to machine through conventional methods. Titanium and its alloys are one of the difficult materials to machine since they cause galling on the cutting tool. This paper reports on the material characterization of Laser Metal deposited TiC on Titanium alloy grade 5 and the effect of varying the powder flow rate on the evolving properties of the material. The clads were characterized through microstructural analysis, hardness and degree of porosity. The physical appearances of the samples appeared sound without defect. However, the surfaces of the samples were rough. Furthermore, the average microhardness decreased as the powder flow rate was increased. The microstructural evaluation revealed that the grain size in the deposit zone becomes shorter as the powder flow rate was increased. The microstructure in the heat-affected zone had smaller grain sizes relative to the grain sizes in the deposit zone. In addition, the porosity characterization revealed that the number of pores increases when the powder flow rate increases.
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Characterization of functionally graded commercially pure titanium (CPTI) and titanium carbide (TiC) powders

  • Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
  • Date: 2015-07-01
  • Subjects: Functional graded materials , Laser metal deposition , Titanium , Titanium carbide
  • Type: Article
  • Identifier: uj:5136 , ISBN 9789881404701 , http://hdl.handle.net/10210/14102
  • Description: Functionally Graded Materials (FGM) are advanced materials fabricated using additive manufacturing techniques. It belongs to a class of advanced material characterization in which the properties of the material composition is varied. The resulting property of the composite is always different from the properties of the individual material employed in the formation of the composite. They are known to also exhibit good mechanical and chemical properties and as such, are used for different industrial applications. One of the techniques employed in the fabrication of FGMs is called Laser Metal Deposition (LMD) technique. It uses laser beam to melt powder material on a substrate forming a melt pool that solidifies upon cooling. This paper reports on the material characterization of functionally graded Titanium and Titanium Carbide (TiC) powders deposited on Titanium substrate by laser metal deposition approach. The formed deposits were fabricated by varying the processing parameters such as laser power, scanning speed and the powder flow rate. From the result obtained, the microstructures showed that the laser power has much influence on the grain growth of the material. In addition, with the SEM analysis of the microstructure since the percentages of the titanium and titanium carbide were varied, it was observed that the sharp boundaries of the Titanium Carbide were reduced greatly and this resulting effect can be attributed to the thermal effect of the laser. The microstructures further revealed that as the percentage of TiC decreases, it becomes more difficult to see the TiC as a different material in the composite, emphasizing this as one of the best characteristics of functionally graded materials, which is the elimination of sharp interfaces and layers. Furthermore, it was observed that the laser power has great influence on the evolving hardness of the material compared to the TiC content.
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Characterising the effects of heat treatment on 3CR12 and AISI 316 stainless steels

  • Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
  • Date: 2014
  • Subjects: Stainless steel - Heat treatment
  • Type: Article
  • Identifier: uj:4736 , http://hdl.handle.net/10210/11722
  • Description: This paper reports on the effects of heat treatment on 3CR12 and AISI 316 stainless steel grades. Heat treatment was conducted on the steel grades and cooled using two different media; air and water in order to study the effect of each medium on the evolving properties of the samples. The heat treated samples were characterized through the evolving microstructure and hardness. It was found that there was a significant grain size reduction in both the heat treated stainless steel specimens compared to the parent materials. The finer grain sizes were achieved as a result of impediment to growth of one phase by the other. The Vickers microhardness values of the heat treated samples were higher compared to the parent materials due to the fact that each of the steel grades had a proportion of martensitic structures in their microstructures thereby improving the integrity of the material.
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Effect of number of laser scans on the corrosion behavior of laser formed titanium alloy

Friction stir welding of aluminium and copper : fracture surface characterizations

  • Authors: Akinlabi, Esther Titilayo , Akinlabi, Stephen A.
  • Date: 2014
  • Subjects: Aluminium , Copper , Fracture surfaces , Friction stir welding
  • Type: Article
  • Identifier: uj:4745 , ISSN 2078-0966 , http://hdl.handle.net/10210/11731
  • Description: Butt welds of aluminium alloy and copper alloy were produced by Friction Stir Welding by varying the feed rate and keeping all other parameters constant. The final weld matrix was composed of welds produced by a constant rotational speed of 600 rpm and the feed rate varied between 50 and 300mm/min. The microstructure and fracture surfaces of the joint interfaces were investigated. The results revealed that the joint interface was characterised with mixed layers of both materials joined. The strongest weld was produced at the highest feed rate employed at 300 mm/min. The fracture surfaces were characterised with thin layers of intermetallic compounds and can be considered fit for practical applications.
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