Browsing by Author "Mohammed, F."

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    Optimization of Process Parameters for Catalytic Pyrolysis of Waste Tyre using Reactivated Fluid Catalytic Cracking Catalyst
    (Department of Chemical Engineering, Nasarawa State University Keffi, 2023-05-11) Obi, M. Bisong; Abubakar, A.; Yunusa, Suleiman; Mohammed, F.
    This work investigated the optimization of process parameters for catalytic pyrolysis of waste tyre using reactivated spent Fluid catalytic cracking (FCC) catalyst. The waste tyre pyrolysis used design expert software as the optimization tool for this study. A 3-factor level CCD with 20 experimental runs was used with temperature, time and catalyst as the input parameters while oil yield, density and viscosity were the output variables. Thereafter, an experimental validation of the optimized parameters, which were not among the original experimental runs, was carried out. Pyrolysis was also carried out at the optimized conditions with un-reactivated catalyst and without catalyst to ascertain the contributions of the catalyst and its reactivation. Based on the optimum parameters, 48.5 wt. % oil (0.79 g/ml and 2.05 cSt) was produced with the reactivated catalyst, 43.4 wt. % (0.86 g/ml and 3.52 cSt) was produced with spent catalyst, and 51 wt. % oil (0.95 g/ml and 4.24 cSt) was produced without catalyst. The oil yield without catalyst was higher than with reactivated catalyst (R-CAT); but it however had the lowest fuel qualities while oil produced with catalyst in turn had higher quantity and quality compared to oil produced with catalyst. Therefore, the incorporation of density and viscosity of the oil in the optimization of the catalytic pyrolysis of waste tyre enhanced the improvement of yield and quality of the oil produced.
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    Phytochemical and Antibiofilm Activity of Aloe barbadensismiller (Aloe vera) on Candida albicans Isolated from Urinary Catheter
    (Department of Microbiology, Nasarawa State University Keffi, 2021-03-06) Galleh, Raphael Peter; Nwosisi, Favour C.; Mohammed, F.; Aisha, F.
    Aims: To screen for phytochemicals present in Aloe barbadensismiller (Aloe vera) growing within the Main Campus of Nasarawa State University Keffi (NSUK), determine biofilm forming ability, and to investigate the antibiofilm activity of the plant extracts on biofilm formed by clinical isolates of Candida isolated from urinary catheters. Study Design: The leaf of Aloe vera were collected and maceration method was used to extract the plant materials used for the screening of bioactive components. Swab samples were collected from the surfaces of patients’ urinary catheters presenting at Federal Medical Centre and Nagari Hospital, Keffi respectively, irrespective of their ages and sexes. Biofilm forming ability of the isolates was investigated and the antibiofilm activity of the plant extracts determined. Ordinary one-way ANOVA was used to analyze the data where P = .05. Place and Duration of Study: The research was carried out in the Microbiology Laboratory of NSUK, using the Aloe vera plant collected within the University community and the biofilm analysis was conducted at National Veterinary Research Institute, Vom Plateau State, between October 2018 to March 2019. Methodology: Both the aqueous and ethanolic extracts were screened for aloin, tannins, saponins, glycosides, flavonoids, phenols, alkaloids etc, and the Candida species were subjected to biofilm formation in a flat bottom 96-well microtiter polystyrene plate using crystal violet assay. Broth microdilution method was used to determine the minimum inhibitory concentrations (MIC) of the extracts whereas, antibiofilm activity of the extracts was investigated by growing biofilms in the presence of Aloe vera leaf extracts. Results: The presence of tannin, saponins, phenols, reducing sugars and aloin were found in the leaf aqueous extract while alkaloid, flavonoid, glycoside, tannin, phenols, reducing sugars, terpenoids, quinones and aloin in the ethanolic extract. Clinical isolates of Candida were found to be strong biofilm formers (70%). Both the aqueous and ethanolic extracts had significant effects on initial cell attachment where P = .05, however, none was able to achieve complete biofilm eradication, including the positive control ketoconazole. Ethanolic extract inhibits C. albicans cell attachment by 54.25%, aqueous extract 25.68% and ketoconazole has 48.54% percentage inhibition, respectively. Interestingly, ethanolic extracts showed a better antibiofilm property (37.38%) compared to ketoconazole that had 33.98% biofilm inhibition. Conclusion: The leaf extracts of Aloe barbadensismiller has significantly reduced biofilm formed by clinical isolates of Candida. Coating of urinary catheters with A. vera extracts can decrease nosocomial infections, morbidity, and high mortality as well as financial burden, hence, serving as an alternative treatment for urinary tract infections.