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Omu Aran, Nigeria

Olufemi Adebesin B.,Landmark University
Indian Journal of Radio and Space Physics | Year: 2012

The present work emphasizes on foF2, the critical frequency of the F2 layer, variations during peak geomagnetic disturbances (Dst ≤ -100 nT) at the rise of solar cycle 23. Geomagnetic, interplanetary and solar wind parameters have been studied as well as foF2 data from five ionosonde stations in the Asian sector. The study shows that: (i) the observed enhancement immediately after sunset at Petropavlovsk compared with foF2 upwelling after sunrise at Magadan after the storm on 12 February 2000 revealed that there is no simultaneity in foF2 during the activity, (ii) the variation of foF2 along a line of fixed latitude, as it occurs at four stations during the 12 August 2000 storm, shows the diurnal anomaly, which depends on the season and epoch of the solar cycle, reaching maximum before sunrise, and (iii) at any latitude, factors other than solar radiance play an important role in determining the foF2 variations. The results seem to agree with earlier works. The morphology of both positive and negative phase storms is also discussed. Source

There is paucity of information on quality and cheap feedstuffs for snail production in the Tropics. The performance, nutrient digestibility, carcass analysis and organoleptic qualities of snailets of Archachatina marginata fed diets containing graded levels of dried lettuce (DL) were assessed in a 20 week trial. 180 snailets with average weight of 9.18 ± 2.67 g were allotted to 4 diets of 45 snailets per treatment and each treatment replicated thrice with 15 snails per replicate. Snailets were randomly distributed into 4 dietary treatments consisting of 0% DL(T1), 25%DL(T2), 50%DL(T3) and 100%DL(T4) with DL replacing maize in a completely randomized design. Water and feed were presented ad libitum while feed intake and weight gain were measured on daily and weekly basis respectively. Shell length and width were measured with vernier caliper while shell thickness was measured with a micrometer screw gauge on weekly basis. The body weight gain, feed per gain and nutrient digestibility of snailets on T1, T2 and T3 were similar, higher and significantly different (P < 0.05) from those of snailets on T4. The dressing percentages in all the treatments were similar. The organoleptic assessment revealed that the dietary treatments had no significant effect (P > 0.05) on the color, taste, flavor, texture and overall acceptability of the snail meat. Snailets on diet T3 were the best in terms of economy of production by having a feed cost savings of 9.16% when compared with the control diet with no dried lettuce. In conclusion, it can be stated that diet T3 containing 50% DL replacement for maize was the best in terms of performance, nutrient digestibility and economy of production amongst the tested diets. © 2016 Elsevier B.V. Source

Adeyemi O.S.,Landmark University | Sulaiman F.A.,University Of Ilorin
Journal of Biomedical Research | Year: 2015

Diminazene aceturate is a trypanocide with unwanted toxicity and limited efficacy. It was reasoned that conjugating diminazene aceturate to functionalized nanoparticle would lower untoward toxicity while improving selectivity and therapeutic efficacy. Silver and gold nanoparticles were evaluated for their capacities to serve as carriers for diminazene aceturate. The silver and gold nanoparticles were synthesized, functionalized and coupled to diminazene aceturate following established protocols. The nanoparticle conjugates were characterized. The free diminazene aceturate and drug conjugated nanoparticles were subsequently evaluated for cytotoxicity in vitro. The characterizations by transmission electron microscopy or UV/Vis spectroscopy revealed that conjugation of diminazene aceturate to silver or gold nanoparticles was successful. Evaluation for cytotoxic actions in vitro demonstrated no significance difference between free diminazene aceturate and the conjugates. Our data suggest that surface modified metal nanoparticles could be optimized for drug delivery systems. © 2015 by the Journal of Biomedical Research. Source

Owamah H.I.,Landmark University | Izinyon O.C.,University of Benin
Bioresource Technology | Year: 2015

Biogas kinetic models are often used to characterize substrate degradation and prediction of biogas production potential. Most of these existing models are however difficult to apply to substrates they were not developed for since their applications are usually substrate specific. Biodegradability kinetic (BIK) model and maximum biogas production potential and stability assessment (MBPPSA) model were therefore developed in this study for better understanding of the anaerobic co-digestion of food waste and maize husk for biogas production. Biodegradability constant (k) was estimated as 0.11d-1 using the BIK model. The results of maximum biogas production potential (A) obtained using the MBPPSA model were found to be in good correspondence, both in value and trend with the results obtained using the popular but complex modified Gompertz model for digesters B-1, B-2, B-3, B-4, and B-5. The (If) value of MBPPSA model also showed that digesters B-3, B-4, and B-5 were stable, while B-1 and B-2 were inhibited/unstable. Similar stability observation was also obtained using the modified Gompertz model. The MBPPSA model can therefore be used as an alternative model for anaerobic digestion feasibility studies and plant design. © 2015 Elsevier Ltd. Source

Betiku E.,Obafemi Awolowo University | Adepoju T.F.,Landmark University
International Journal of Energy and Environmental Engineering | Year: 2013

Statistical approach was employed to optimize biodiesel production from sesame oil in this work. Precisely, response surface methodology was applied, and the effects of four variables, viz. reaction temperature, catalyst amount, reaction time, and methanol/oil molar ratio, and their reciprocal interactions were determined. Central composite rotatable design was used to generate a total of 30 individual experiments, which were designed to study the effects of these variables during alkali-catalyzed methanolysis of sesame oil. A statistical model predicted the highest conversion yield of sesame biodiesel to be 99.71% at the following optimized variable conditions: reaction temperature of 63°C, catalyst amount of 1.04 wt.%, and methanol/oil molar ratio of 6.24, with a reaction time of 51.09 min. Using these variables under experimental condition in four independent replicates, an actual biodiesel yield of 98.36% was accomplished. The fuel properties of biodiesel produced were found to be within the ASTM D6751 and DIN EN 14214 biodiesel specifications. © 2013 Betiku and Adepoju. Source

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