scholarly works
Permanent URI for this collectionhttps://repository.ui.edu.ng/handle/123456789/473
Browse
20 results
Search Results
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 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 Design and fabrication of a water distiller(Scholarlink Research Institute, 2010) Oyawale, F. A.; Odior, A. O.; Ismaila, M. M.The objective of this project is to design and fabricate a low cost water distiller capable of producing water that is pure in all ramifications for domestic and commercial consumers. The critical components of the distiller are made of stainless steel. These parts include the tank, the lid/condenser and the distilled water collector. Selection of material used is based on both their physical and chemical properties. The tank has a square base and the opening end of the tank is slanted. This will make the condensate to trickle downward for collection at the end of the lid. The lid is continuously cooled by water at room temperature that runs from a tap. The distiller is able to produce 29.4 x 10-3 litres (29.4 ml) of distilled water in 10 minutes. Once the water is boiled, the heater can be switched off and continuous cooling of the condenser/lid could last 30 minutes. The volume of water produced is approximately 105.3ml. Distillation continues until the temperature drops to room temperature i.e. 25°C by which time, the volume of distilled water will drop since the production of steam will decrease due to the drop in temperature of water in the tank. The water distiller is designed and fabricated from locally sourced materials and this makes it cheap and affordable to the common man in our society.Item Optimisation of weld-metal chemical composition from welding flux ingredients: A non-pre-emptive goal programming approach(Maejo University, San Sai, Chiang Mai, 50290 Thailand., 2010) Adeyeye, A. D.; Oyawale, F. A.A non-pre-emptive goal programming (NGP) model for weld-metal chemical composition optimization from welding-flux ingredients is proposed. The proposed model, which is the first multi-objective mathematical programming approach to welding-flux formulation, provides increased flexibility to the welding-flux formulator in several ways: (1) several conflicting objectives can be simultaneously considered, (2) the best compromise for welding-flux formulation can be achieved with minimal expenditure of resources and experimental efforts, (3) the welding-flux designer can explore various trade-off options, and (4) the lead time and cost of developing welding consumables can be drastically reduced. This paper has extended the work of Kanjilal and co-investigators by coupling it with the NGP optimisation technique so as to prescribe the welding-flux ingredient levels that will achieve optimum performance for the flux at minimum experimental efforts and cost. The feasibility and suitability of the model is illustrated with data from the literature.Item Multi-objective methods for welding flux performance optimization(Faculty of Natural Science and Engineering, Ljubljana, Velenje Coal Mine and Institute for Mining, Geotechnology and Environment (IRGO), Ljubljana, 2010) Adeyeye, A. D.; 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 limitations of the traditional approach to welding flux design. The methods are weighted-sum scalarization (WSS), desirability indices, goal programming and compromise programming. The steps a welding flux designer (WFD) may follow to determine the best compromise welding flux, welding flux design situations where each may be useful and tradeoff 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 A model for tracking temperature variation in cold and, hot metal working conditions during machining operations(Springer International Publishing, 2010-01) Oke, S.A.; Oyedokun, I. O.; Momodu, O. S.; Akanbi, O. G.; Oyawale, F. A.This paper presents a mathematical model that could assist in measuring, monitoring and controlling temperature variation in cold and 'red-hot' metal working conditions of machining. A numerical analysis technique of the temperature distribution, based on the theory of complex applied potential, was carried out using the principles of relationship analysis between the paths of heat supply in Cartesian plane when the heat path supplied to the material is orthogonal. The high level of temperature involved may effectively be predicted if a mathematical relationship that predicts the pattern of temperature distribution in a material is available. A case study example in a machine workshop is given. Simulation experiments are then carried out using Monte Carlo to increase the confidence in decision-making and provide data for significance testing. This was used as an input for testing for significance. Sensitivity analyses were also carried out in order to observe the degree of responsiveness of model parameters to changes in value. In all, five pairs of comparison were carried out among different workpiece materials. There are significant differences between workpiece materials made of steel and copper, copper and zinc, copper and aluminum. However, no significant differences exist in the model behavior of steel and aluminum, steel and zinc. It was observed that parameters are highly sensitive to changes in value. The framework could possibly be applied to milling and surfacing activities in the engineering workshop. This contribution may be helpful to small-scale enterprises that could not afford sophisticated and very expensive facilities.Item Some operations of electric power supply system in Benin City area of Nigeria(Science Hub, 2010) Odior, A. O.; Oyawale, F. A.; Ovuworie, G. C.The Power Holding Company of Nigeria (PHCN) is responsible for generating, transmitting, distributing and selling electric power to the various consumers throughout the country. The paper presents the results of an investigation conducted on some of the operations of Power Holding Company of Nigeria (PHCN) to determine some of the major factors affecting the availability of power supply to consumers in Benin City area of Nigeria. The average number of operating transformers in various substations and their percentage loadings were also studied. It was discovered that the average power supply to Government Reservation Area (GRA) was more regular and stable than that of Siluko area of Benin City.Item Some grinding factors affecting locally formulated silicon carbide abrasive wheels(Nigerian Institution of Production Engineers, 2010-04) Odior, A. O.; Oyawale, F. A.; Akpobi, J. A.; Charles-Owaba, E.O.A grinding wheel is an expendable wheel which is made of very small, sharp and hard silicon carbide abrasive particles or grits held together by strong porous bond. This paper presents a study on some factors and parameters of silicon carbide abrasive grinding wheels which were developed and formulated from locally sourced raw materials in Nigeria. Six local raw material substitutes were identified through pilot study and a systematic search for an optimal formulation of silicon carbide was conducted using the Taguchi method. The produced silicon carbide abrasive grains were used to manufacture grinding wheels. Some of the grinding factors of locally manufacture grinding wheel include: wheel wear, wheel grinding ratio, wheel hardness, bond strength, size and grade of the manufactured silicon carbide abrasive grains.Item Manufacture of abrasive grinding wheel using silicon carbide abrasive materials(2010-04) Odior, A. O.; Oyawale, F. A.; Charles-Owaba, O. E.; Akpobi, J. A.Abrasive materials are materials of extreme hardness that are used to shape other materials by a grinding or abrading action and they are used either as loose grains, as grinding wheels, or as coatings on cloth or paper. A grinding wheel is made of very small, sharp and hard silicon carbide abrasive particles or grits held together by strong porous bond. The manufacture of silicon carbide abrasives and grinding wheel in Nigeria has been severely impeded by the difficulty of identifying suitable local raw materials and the associated local formulation for abrasives and grinding wheel with global quality standards. This paper presents a study on the formulation and manufacture of abrasive grinding wheel using silicon carbide abrasive grains in Nigeria. Six local raw material substitutes were identified through pilot study and with the initial mix of the identified materials, a systematic search for an optimal formulation of silicon carbide, the intermediate product, was conducted using the Taguchi method. The mixture was fired in a furnace to 1800°C for 6 hours forming silicon carbide chunks, which were crushed and sieved into coarse and fine grades of abrasive grains. Combining each grade with appropriate proportion of latex binder to form paste in a compressed mould cavity of desired shape and size, coarse and fine grinding wheels of international standard were produced.Item Manufacture of abrasive grains from locally sourced raw materials in Nigeria(Scholarlink Research Institute, 2010) Odior, A. O.; Oyawale, F. A.The manufacture of abrasive grains in Nigeria has been severely impeded by the difficulty of identifying suitable local raw materials and the associated local formulation for abrasives with global quality standards. This paper presents study on the formulation and manufacture of silicon carbide abrasives using locally sourced raw materials in Nigeria. Five local raw material substitutes were identified through pilot study and with the initial mix of the identified materials a systematic search for an optimal formulation of silicon carbide abrasive grains was conducted. The mixture was fired in a furnace to 1600⁰C for 6 hours forming silicon carbide chunks which were crushed and sieved into coarse and fine grades of abrasive grains of international standard