Browsing by Author "OGUNLEYE, O. O."

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    FACTORIAL DESIGN BASED OPTIMISATION OF CREVICE CORROSION FOR TYPE 304 STAINLESS STEEL IN CHLORIDE SOLUTIONS
    (ADVANCES IN MATERIALS SCIENCE (De Gruyter), 2016-06-01) OGUNLEYE, O. O.; Adeniyi, A. G.; Durowoju, M. O.
    The effects of chloride concentration, creviced scaling factor and immersion time on the percentage area and maximum depth of attack for Type 304 stainless steel (SS304) in chloride solutions were investigated. The crevice assembly comprised of coupon (SS-304), polytetrafluoroethylene (crevice former) and fasteners (titanium bolt, nut and washers). The full immersion tests were based on ASTM G-78 using full factorial design to study the effects of chloride concentration (1.5, 3.0 and 4.5 w/w%), crevice scaling factor (8, 16 and 24) and immersion time ( 15, 30 and 45 days) on the percentage area of attack (Y1) and maximum depth of attack (Y2) of SS-304. Data obtained was used to develop and optimize the models of Y1 and Y2 in terms of the three factors using Response Surface Methodology (RSM). The R2 of Y1 and Y2 were 0.98 and 0.91, respectively. The minimum Y1 (5.63%) and Y2 (3.32x10-7 mm) were obtained at 4.5% chloride concentration, 20 scaling factor and 15 days immersion time. The predicted optimal conditions agreed with the experimental results for validation with a maximum absolute relative error of 5.75%.
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    Identification and Characterisation of Major Hydrocarbons in Thermally Degraded Low Density Polyethylene Films
    (J. Appl. Sci. Environ. Manage, 2017-10-21) ELETTA, O. A. A.; AJAYI, O. A.; OGUNLEYE, O. O.; TIJANI, I. A.; ADENIYI, A. G.; AGBANA, A. S.
    The vast application of Low Density Polyethylene (LDPE) in packaging, greenhouses, homes etc has led to its huge accumulation as a municipal solid waste with monumental health, economic and environmental consequences. Since these are non-biodegradable and their photodegradation occurs only over a very long period, their economic conversion to energy products through pyrolysis is the thrust of this study. LDPE sample collected from the University of Ilorin Community was thermally degraded in a pyrolyser at temperatures ranging from 203 – 400 oC. The products of pyrolysis were in three (3) states of matter and both the liquid and solid products were analysed using FTIR to determine the functional groups and GC- MS for the hydrocarbons present in the products. For the GC-MS analysis, the peaks that had 90% above quality when compared with the compounds in the installed NIST11 library were reported. There were alkanes, alkenes, halogenated alkanes, and very few aromatics in the liquid product and, the hydrocarbons were observed to range between C10 - C27. The FTIR and GC-MS results show the potential of the oil obtained as renewable source of energy while that for residue shows its inherent energy content. The liquid product was refluxed over molecular sieve catalyst (US 2882244A) and the calorific value was found to increase from 13,974 kJ/kg to 15,815.52 kJ/kg and this is found to be comparable to the range for lignite and dry wood.