Browsing by Author "Onukwuli, O. D."

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    Effect of mahogany filler on mechanical properties of reinforced polyethylene matrix
    (SAVAP International, 2013-07) Olaitan, S. A.; Azeez, T. O.; Atuanya, C. U.; Onukwuli, O. D.; Officha, M. C.; Menkiti, M. C.
    The effect of mahogany filler as an agricultural waste material used in thermoplastic polymer composite was investigated. Polyethylene (PE), as the matrix, and mahogany sawdust, as the filler, were prepared in five levels of filler loading (10, 20, 25, 30, and 35 wt %) to form thermoplastic composites.Two forms of composite samples were prepared with a recycled polyethylene and mahogany wood filler called recycled polyethylene (RPE) composite and 20 percent of virgin polyethylene with recycled polyethylene wood filler called virgin polyethylene recycled polyethylene (VRPE)composite and their mechanical properties were studied. Test results show that the tensile strengths, tensile modulus, flexural strengths, flexural modulus and hardness properties increased while impact strength, decreased with increase in filler loading for the mixed polyethylene composites but tensile strength of there cycled polyethylene composite decreased with increased filler loading. The appreciable improvement on the tensile strength indicates that mahogany can be used as a reinforced material of the mixed polyethylene composite. Again the presence of 20 percent of virgin PE has significant effects (p < 0.05) on mechanical properties of the mahogany filler – recycled polyethylene composite.
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    Optimization of bioremediation of cheese whey with the activity of klebsiella pneumonia using response surface methodology
    (U. P., 2013) Azeez, T. O.; Onukwuli, O. D.; Araromi, D. O.; Arinkoola, A. O.; Salam, K. K.; Iwuji, S. C.; Ejeta, K. O.; Dawodu, B. F.; Ayinde, K. A.; Nwacha, R.; Azeez, F. O.
    Response surface methodology was used to study the optimization of bioconversion of cheese whey to 2,3-Butanediol using Klebsiella pneumonia at room temperature. 3-Level factorial design was employed to correlate the bioremediation parameters with the biomass of K. pneumonia and concentration of 2,3-BD as response. Quadratic polynomial equation was developed to achieve optimal performance of the process. The result showed that the optimum condition for the bioremediation process in unaerated and airlifted batch reactors for concentration of cheese was 39.98g/L and 39.94g/L, and fermentation time was 95.5hours which resulted in biomass of k. pneumonia 1.4633mg/L and 3.6580mg/L, and 2,3-BD production of 10.696g/L and 17.997g/L respectively. 2,3-BD production in unaerated and airlifted batch reactors amounted to 36.88% and 62.06% respectively. The study has shown that k. pneumonia not only utilized cheese whey as a source of food and energy but optimally better for remediation of cheese whey in airlift batch reactors.
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    Tensile response of treated cissus populnea fibers
    (U. P., 2018-01) Azeez, T. O.; Onukwuli, O. D.
    Improvement and effectiveness of polymers through reinforced materials coupled with environmental nuisance of the Cissus populnea fiber remains an area of concern. Tensile responses of chemically treated C. populnea fibers were investigated. Gravimetric analysis was used to determine the composition of C. populnea fibers. Sodium hydroxide (NaOH), acetic anhydride (AC) and ethylene diaminetetra-acetic acid (EDTA), respectively, were used for fiber treatment and optimized with variable parameters (concentration and time) using response surface methodology (RSM) with central composite design. Scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) were studied. At optimum treatment conditions, NaOH, AC and EDTA, respectively, increased the tensile strength of C. populnea fiber by 33.49, 274 and 194.52% as well as tensile modulus by 793.43, 20799.43 and 855%. Hence acetic anhydride treatment gave the best tensile properties of C. populnea fibers as corroborated by SEM with EDS. Thus, the effective use of C. populnea fiber in composite applications can be improved by chemical surface modifications.