scholarly works
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Item Mutli-objective methods for welding flux performance optimization(Faculty of Natural Science and Engineering, Univeristy of Ljubljana, 2010) Adeyeye, D. A.; Oyawale, F. A.The traditional welding flux development is by lengthy and costly trial and error experiments and the optimum welding flux formulation is not guaranteed. This paper presents discussions on promising multi- objective decision making (MODM) methods that can mitigate the limi- tations of the traditional approach to welding flux design. The methods are weighted-sum scalarization (WSS), desirability indices, goal pro- gramming and compromise programming. The steps a welding flux de- signer (WFD) may follow to determine the best compromise welding flux, welding flux design situations where each may be useful and trade- off explorations were mentioned. No attempt was made to determine the relative merits of the approaches because the usefulness of each depends on the welding flux design situation. The descriptions only serve as a guide for the WFD to decide which method best suits his needs.Item Mixture Experiments and their applications in welding flux design(Associação Brasileira de Engenharia e Ciências Mecânicas - ABCM, 2008) Adeyeye, D. A.; Oyawale, F. A.The traditional welding flux development has been by cost, material, time and labour intensive experiments. The extensive and expensive trial and error experimentation is needed because it is often difficult to know a priori how the flux ingredients interact to determine the operational characteristics of the flux and the final performance of the welded structure. The limitation of the traditional approach includes: (1) long lead-time (2) expensive experiments in terms of materials and energy consumption and labour requirements (3) the flux developed can not be guaranteed to be optimal and (4) inability to identify and quantify direct and interaction effects of flux ingredients. These constraints are due to the paucity of statistical modelling tools in welding flux technology. Since prediction models are derived from designed experiments, flux researchers need other methods by which flux experiments may be designed. This paper discusses a statistical modelling tool known as mixture experiment which has the potential to revolutionize welding flux development technology. Mixture design is discussed but not fully developed. The procedure of mixture experiment, analytical model forms and the sequence of model fitting are discussed. Areas of welding flux research where the various mixture designs may be useful are suggested.Item Quality characteristics of basic hand tools sold in Nigeria(Trans Tech Publications, 2009) Oyawale, F. A.; Ogunmolati, M. A.Hand tools sold in Nigeria have become increasingly unreliable due to critical failures during use. The objective of this study is to test samples of these tools vis-a-vis manufacturer's claims. A total of fifteen (15) hand tools from six (6) different countries available on the Nigerian market were tested for their quality characteristics. The tested tools included spanners, hammers, screwdrivers, pliers and chisels. Three samples of each of the groups of hand tools were ranked in accordance to their impact energy which is a major property of percussion tools. The results showed that built-in mechanical properties of these hand tools were largely controlled by their alloying elements, manufacturing processes and heat-treatment. Five (5) of the fifteen (15) selected hand tools conformed to BS 876, 1981 and were adjudged safe and reliable.Item Manpower planning using decision analysis: case of crown company(Akamai University, Hilo, Hawaii, 2008) Oyawale, F. A.; Adegboyega, O. A.This study addresses the analytic approach to decision making and its application to manpower planning in the crown section of a bottling company in Nigeria. The company produces crowns for several bottling companies and was faced with the challenge of meeting customer's demand, which varied from month to month. A work sampling technique was used to investigate the discrepancy between the level of the work force and their output. The result of the work sampling study showed that all of the departments were overstaffed with idle time and that overtime, rather than additional shifts, would reduce manpower cost. The results have been applied to the management policies that can be employed to meet increasing short term demand.Item Local sourcing of raw materials for the manufacturing of manual metal arc welding electrodes: a case for locally produced steel wire in Nigeria(Dincan Science Company, 2008) Oyawale, F. A.Since early 1995 when pressure was mounted on the Raw Materials Research and Development Council in Nigeria, with a view to sourcing wire, flux and binder locally, little or no success has been recorded. As at 1998, all the raw materials including core wire for electrode manufacture in Nigeria were still being imported. The aim of this project is therefore to explore the possibility of using locally sourced wire in electrode production. In this research, wire drawn at the Oshogbo rolling company in South Western Nigeria from billets produced at Delta Steel Company Aladja in Delta state, Nigeria was used with commercial flux in a production run by a local electrode manufacturing outfit. Mechanical tests and microstructure show that the quality of electrodes produced compared favourobly with E6010 standards.Item Investigation of the grain structure of the fusion zone of single pass arc welding of structural steel (NST 34 L-C)(Akamai University, Hilo, Hawaii, 2008-06) Oyawale, F. A.; Sanusi, K. O.Some welded structures show poor mechanical properties at the weld and the adjacent zones. This has led to the collapse of structures when subjected to various torques. This research investigates the grain structure of the fusion zone of a single pass arc welding of structural steel to identify the mode of growth and grain transition of the zone and adjacent weld. Two parameters -temperature gradient in the direction of solidification and rate of advance of solidification were studied vis-a-vis welding speed, arc current and plate thickness. The results showed that chances in the welding variables affected the mechanical properties of the welded structure.Item Evaluation of safety practices and performance in a brewery industry in Nigeria between 2000 - 2007(World bank assisted National Agricultural Research Project (NARP)- University of Port Harcourt and supported by the Institute of Petroleum Studies(IPS) and Swets Information Services BV, The Netherlands., 2011) Oyawale, F. A.; ODior, A. O.; Bolanle, R. O.Safety practices and performance in a brewery industry in Nigeria was evaluated for a period of eight years between 2000 - 2007 using the principles of statistical expectation and efficiency index. The number of prevented accidents and the corresponding values of lives and property saved were estimated annually for the same period of eight years. The type of input resource, total number of input resources, total number or prevented accidents by class, the unit cost of each of the accident class, the cost of input resources, quantity of each type of input resources and the targeted period were identified. The study revealed that a total of 156 accidents were prevented in the period of the safety programme which translates to an average of 19.45 per year. The safety programme also saved lives and property worth N20.2 million for the eight year period which is at an average of N2.5 million annually. The computation of efficiency indices due to the use of all the input resources when compared with the standard period and it was discovered that all the resources were well utilised. The significance and benefits of the work to the local community and other industries is that the principles of statistical expectation and efficiency index can be easily applied to analyse the performance of safety programme in the industries.Item Ethanol extraction from wheat(Uyo, Akwa Ibom State, Nigeria : International Research and Development Institute, in association with Kan Educational Books, 2009) Oyawale, F. A.; Olawale, O.Current hike in the price of crude oil in the world market has produced ripples in the economy of nations. Research has therefore been in the area of renewable energy to break the monopoly of fossil fuel. One of such renewable fuels is ethanol. Ethanol has been produced from various feedstock. The objective of this project therefore is to produce ethanol using wheat as the feedstock. Fermentation was carried out to convert glucose (C6H12O6) to ethanol (C2H5OH) and carbon dioxide gas (CO2). 12 liters of fermented mash was heated in the boiler and the first condensate which was 60% water was collected in the receiver between 77°C and 82°C. After discarding the residue in the boiler, the first run distillation was reheated to 95.5° C, when 70% ethanol plus by- products was obtained. This process was repeated a third time. The distillate collected was (E85) i. e. 85% ethanol which was about 170 proof . This ethanol was very flammable.Item Development of FeO, TiO2-SiO2-CaCO3 system as a welding flux(2004) Oyawale, F. A.; Ibhadode, A. O. A.Using local raw materials, various metal-arc welding fluxes were formulated. A ternary system of FeO, TiO2- SiO2-CaCO3 gave satisfactory results. Average values of 546 N/mm2 ultimate tensile strength and 10% elongation were obtained from all-weld metal tensile specimen. The formulation also gave a metal deposition efficiency of 88.9%Item Design and prototype development of a mini-electric arc furnace(Akamai University, Hilo, Hawaii, 2007-05) Oyawale, F. A.; Olawale, D. O.Electric arc furnaces (EAF) have the capabilities required for furnaces used for metallurgical research. An electric arc furnace was designed and constructed to melt approximately 5kg of steel/cast iron scraps, using locally produced Soderberg electrodes. Tests carried out showed that it required about 60 minutes to heat up the furnace to the melting temperature of cast Iron (1150C - 1400C). It took about 95 minutes to melt the first charge of 2kg resulting in a melting rate of 21.05g/minute. The average electrode consumption rate was 0.0467cm/minute. A transformer efficiency of about 83% was also achieved.