Influence of Magnetic Field and Thermal Radiation on Steady Free Convective Flow in a Porous Medium

This paper investigated the influence of magnetic field and thermal radiation on steady free convective flow embedded in a porous medium with Soret effects. The governing equations are systems of nonlinear partial differential equations. Similarity variables were introduced on the set of governing equations and it was transformed into set of coupled nonlinear ordinary differential equations. The transformed coupled nonlinear ordinary differential equations are solved using the Spectral Homotopy Analysis Method (SHAM). Influence of pertinent flow parameters is displayed in figures and table. Comparisons were done with existing problems/models in literature and our results were in good agreement. The results revealed that as the magnetic parameter increased the velocity profile was found to decrease as a result of the magnetic field applied in the direction of the flow but negligible or has no effect on the velocity distribution. The results shows that increase in the suction/injection velocity and Magnetic field parameter enrich the temperature and concentration.KEYWORDS: Buoyancy; Free Convective Flow; Magnetic Field; Porous Medium; Soret; Suction/Injection

EVALUATION OF BIOGAS POTENTIALS OF Cymbopogon citratus AS ALTERNATIVE ENERGY IN NIGERIA

This research explored the potentials of Cymbopogon citratus (Lemon Grass) for biogas production as a cost effective alternative energy source in Nigeria. The Cymbopogon citratus was crushed to small sizes between 20 to 50mm and pre-fermented for 40 days in a PVC drum. Six (6) kg of the pre-fermented Cymbopogon citratus was mixed with water in ratio 1:1 w/v to form slurry and digested for 30 days. The floating drum gas collection system was used to collect the gas after it was passed through water and lime respectively for scrubbing. A total of 0.125m3 (6.95x10-4 m3/kg/day) and 0.0897m3 (4.98x10-4 m3/kg/day) of biogas was produced from the Cymbopogon citratus before and after scrubbing respectively. The gas produced was used for cooking test. The scrubbed gas had higher cooking rates for both water and rice respectively (0.12L/min and 0.0052L/min) while the cooking rates for unscrubbed gas were 0.079L/min and 0.0036L/min respectively. During this period, daily ambient temperatures of the research environment varied from 310C to 420C while the digester temperature fluctuated between 28oC and 36.70C. The pH of the medium fluctuated optimally between 6.5 and 7.8. The research demonstrated that Biogas could be produced from Cymbopogon citratus in quantity and quality comparative with those in literatures

Tax Audit and Investigation: A Panacea to Increase Revenue Generation in Nigeria

The research work examines the effect of tax audit and investigation on revenue generation in Nigeria. The essence of the study is to determine the effect of tax audit and investigation, which is a viable instrument of relevant tax authority on revenue generation in Nigeria using the tools of tax audit and investigation as measuring indicators. Primary data were sourced through the administration of a structured questionnaire on 162 samples drawn from the total population of Federal Inland Revenue staff in the South-western zone of Nigeria, using Taro Yamane sample size calculator. Descriptive and inferential methods of data analysis were employed to measure the effect of tax audit and investigation’s indictors (desk/office audit, field audit, and audit investigation) on revenue generation. Findings revealed that about 38% variation in revenue generation in Nigeria is due to change in tax audit and investigation’s indicators/variables of DOA, FA, and ANINV, which implies that applications of these variables of tax audit and investigation will improve tax revenue generation in Nigeria as shown from the contributory regression coefficients of 0.576, 0.407, and 0.151 respectively. The study therefore recommends that effective and efficient tax audit and investigation habit should be encouraged by the relevant tax authorities as this will help in curbing taxpayers rendering false returns, reduce tax evasion and eventually improve tax revenue generation in Nigeria. Keywords: Tax Audit, Tax investigation, Field Audit, Office/Desk Audit, Revenue Generation, DOI: 10.7176/RJFA/13-18-05 Publication date:September 30th 202

Application of Split Desktop Image Analysis and Kuz-Ram Empirical Model for Evaluation of Blast Fragmentation Efficiency in a Typical Granite Quarry

Evaluation of fragmentation efficiency is an integral aspect of blasting operation. This study therefore assesses the efficiency of fragmentation size at Eminent granite quarry, Ibadan, Nigeria using Split Desktop software and Kuz-Ram empirical model. Five muckpiles of blasted rocks with the same blast design were analysed. The muckpile images were captured using smart high precision digital camera and uploaded into computer for Split Desktop analysis. The results of the fragment size distribution obtained from Kuz-Ram vary slightly with that of the Split Desktop but follow similar trend. The average values of F80 and F90 from the Split Desktop image analysis were 90.96 cm and 98.24 cm respectively. The Kuz-Ram model values for F80 and F90 were 88.52 cm and 92.95 cm respectively. The results of the Split Desktop were compared to the results obtained from the Kuz-Ram experiential model. The findings showed that the results obtained from Kuz-Ram empirical model were in conformity with the results from the Split Desktop software based on empirical relationship. Hence, the model is good for preliminary evaluation of blast design.   Keywords: Blasting, Particle Size Distribution, Split Desktop Software, Muckpile, Fragmentation Indicato

Generalized Adaptive Backstepping Synchronization for Non-Identical Parametrically Excited Systems

In this paper, we investigate the synchronization of chaotic systems consisting of non-identical parametrically excited oscillators. The backstepping design, which is a recursive procedure that combines the choice of a Lyapunov function with the design of a controller is generalized and employed so as to achieve global chaos synchronization between a parametrically excited gyroscope and each of the parametrically excited pendulum and Duffing oscillator. Numerical simulations are implemented to verify the results

Comparative study of the macroinvertebrate community composition and water quality of Ona and Opa rivers, Southwestern Nigeria

Macroinvertebrate samples of Ona and Opa rivers were taken fortnightly between April and August, 2013 with the aid of a dip net of 500µm mesh size with the aim of evaluating the macroinvertebrate community composition and the water quality of the rivers. A total of 617 individuals macroinvertebrate belonging to 29 species were collected. Ona River was dominated by Chironomid larvae while Opa River was dominated by Trichoptera species. Margalef’ species richness and Shannon-wiener’s species diversity indices both revealed that Opa River is higher in terms of species richness and diversity. The physico-chemical parameters of the two water bodies showed a slightly marked variation, especially for Dissolved Oxygen, Conductivity and Total Dissolved Solids. Ona River was relatively lower in DO level but showed a higher TDS level than Opa River. The species composition and the water quality both indicated that Ona River is more stressed than Opa River due to greater impacts of anthropogenic activities which brought about the observed organically-induced pollution in the water body

Career preferences among final year medical students and house officers: A multicentre survey in Southwest Nigeria

Objective: Career preferences of medical trainees have the potential to shape the future of the healthcareworkforce of any nation. This study aimed to determine the factors that influence career choices ofmedical students and house officers (interns) in two institutions located in Southwest Nigeria.Methods: A cross-sectional study was carried out amongst final year medical students and interns in twomedical universities and their corresponding teaching hospitals in Southwest Nigeria. A questionnairewas used to obtain socio-demographic data, career choices, reasons behind career choices and thepresence and influence of mentorship on career choices. Responses were analyzed using the StatisticalPackage for Social Sciences Version 21, and descriptive statistics generated.Results: Obstetrics & Gynecology and Surgical specialties were the most preferred career choices by themedical students, while Surgical and Medical specialties were most preferred by the interns. Personalinterest and other personal reasons were the top motivating factors for the career choices amongst themedical students of both institutions, while personal interest and future job opportunities were the topreasons for the career choices amongst the interns of both institutions. Mentorship was lacking for most ofthe medical students and house officers, except in one of the teaching hospitals, where over half of theinterns had career mentors.Conclusion: Attention should be paid to the reasons behind career choices, in order to channel effortstowards making clinical specialties become attractive to young medical trainees, as the future of the healthworkforce in the nation depends on it.Keywords: Career Choices, Medical Students, House officers, Medical Education, Nigeri

Shortened versus standard post-partum maintenance therapy of magnesium sulphate in severe pre-eclampsia: a randomised control trial

Background: Pre-eclampsia is a pregnancy-associated multi-organ disorder caused by altered trophoblastic invasion and endothelial cell dysfunction. It is associated with significant maternal and perinatal morbidity and mortality, especially in developing countries. Magnesium sulphate (MgSO4) is effective in the management of severe pre-eclampsia/eclampsia. Objective of this study was to compare the effectiveness of a shortened course of MgSO4 to the Pritchard regimen in patients with severe pre-eclampsiaMethods: This study was carried out at the obstetrics and gynecology department of the Obafemi Awolowo University Teaching Hospital, Ile-Ife. It was a randomised control study of 116 patients, 58 in each group. Group A received the standard Pritchard regimen: a loading dose of MgSO4 4g slow IV bolus plus 10 g IM (5 g in each buttock), followed by maintenance dose of 5g MgSO4 IM 4-hourly into alternate buttocks until 24 hours after delivery. Group B received same loading dose, but the maintenance dose was limited to three doses of 5g MgSO4 IM four hours apart after delivery. In both regimens, 2g MgSO4 was given IV for breakthrough fit. Data were analyzed using SPSS version 20.Results: This study revealed that twelve-hour postpartum MgSO4 was as effective as the Pritchard regime with no statistically difference in occurrence of seizures (X2 = 0.341, df = 1, p = 0.514). The average total dose of magnesium sulphate used was lower in the study Group B.Conclusions: Twelve-hour postpartum MgSO4 is as effective as the standard 24-hour Pritchard regime

Injection-induced Sciatic Nerve Injury Among Children Managed in a Nigerian Physiotherapy Clinic: A Five-Year Review

Injection-induced sciatic nerve injury is a well-known complication of intra-muscular gluteus muscle injections. Affected individuals usually present with foot drop and this results in varying degrees of motor disability depending on the timing, quality and duration of the remedial measures instituted. This study was carried out to evaluate the pattern of cases of injection-induced sciatic nerve injury among children referred to the Outpatient Physiotherapy Clinic of the Federal Medical Centre, Ido-Ekiti, Nigeria. A retrospective review of the case notes of all paediatric patients referred to the physiotherapy clinic on account of injection-induced sciatic nerve injury from November 2005 to October 2010 was done. Information obtained included age, gender, side affected, personnel/place where injection was administered, the mode of physiotherapy intervention, number of sessions, impairment variables at presentation and underlying indication for injection administration. A total of 33 (19.64%) cases of sciatic nerve palsy out of 168 paediatric patients managed at the physiotherapy clinic within this 5-year period were reviewed. The ages of the participants ranged from 0-14 years. Sixteen (48.5%) of the patients were male while 17 (51.6%) were female. The side affected in 17 (51.6%) of the patients was the right while the left was affected in 16 (48.5%) patients. The right side was more affected in the females (12) while the left side was more affected in the males (11). Most incidences of injection-induced sciatic nerve palsy occurred in private hospitals (45.5%). A majority of the patients (69.7%), as reported by their carers and relatives, had the injections administered by nurses. The results revealed that a lot of effort should be made by the relevant authorities to ensure that medical and health professionals who administer injections adhere strictly to safe ethical practices and that unqualified personnel are not allowed to operate. Keywords: children, sciatic nerve palsy, injectio