DEPARTMENT OF INDUSTRIAL AND PRODUCTION ENGINEERING

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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.
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.
Occupational lead exposure in printing presses: an analytical approach
(Akamai University, 2008) Oke, S. A.; Phillips, T. E; Kolawole, A.; Ofiabulu, C. E.; Adeyeye, D. A.
Lead absorption poses a great threat to the health of workers in printing presses where commercial publishing is done. A case example is the commercial printing operations in Lagos, Nigeria. Since regular exposure to lead dusts could result in lead poisoning, complications that could cause death of victims, monitoring and controlling lead absorption of operators is essential for the maintenance of workers’ health and for the avoidance of the risk of incurring heavy losses due to litigation. The purpose of this paper is to model the process, rate, and quantity of lead absorption in operators of printing presses. Measurements of lead absorption are made and compared to standards in individuals for control purposes. Two approaches are used. The first shows the risk of being poisoned by lead. The second approach relates lead poisoning to the rates of intake of lead into the body and its elimination out of the body. This model viewed the absorption of lead as a cycle and applied the continuity equation to this cycle.