109 research outputs found

    MODELING THE PERFORMANCE OF A BAOBAB SEED DECORTICATOR USING RESPONSE SURFACE METHODOLOGY

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    Decortication of baobab seed manually after soaking or roasting is time consuming, labour-intensive and uneconomical. The demand for baobab kernel as a source of protein is increasing for use as supplement for animal protein ration, for edible oil consumption and for other industrial uses. To ameliorate this problem, a baobab seed decorticator has been developed. This study therefore focused on the effects of process parameters; moisture content of seed, speed of decorticator and concave-shaft clearance on percentage clean kernel (Pck), percentage broken kernel (Pbk), percentage whole seed (Pws) and decorticating efficiency (DE), using Response Surface Methodology (RSM). In designing the experiments, Box-Behnken Design (BBD) was selected. Analysis of Variance (ANOVA) was carried out to evaluate and select the appropriate dependent (Pck Pbk, Pws and DE) and independent variables using both the F and P-values calculated at 95% confidence level (a=0.05). Mathematical models relating the process parameters to the responses were developed. The developed models were validated by comparing the predicted and actual experimental values. The selected quadratic models were adequate for predicting the performance of the developed decorticator. It was observed that a decrease in percentage clean kernel recovery would result if concave-shaft clearance and moisture content were increased. Likewise, the concave-shaft clearance had the highest positive effect while moisture content had the highest negative effect on percentage of broken kernel. All the three factors (process parameters) had positive effects on decorticating efficiency

    GEOELECTRIC PARAMETERS AND ELEMENTAL COMPOSITIONS OF THE TOP SOIL OF CAMP AREA, ABEOKUTA, SOUTH WESTERN NIGERIA

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    Vertical Electrical Sounding (VES) and elemental composition surveys were carried out at twenty-two (22) sites atª¤? Camp Area, Alabata Road, Abeokuta, Southwestern Nigeria. This was with a view to determining depth to water«¤??bearing zones and extent of soil contamination thereby saving residents not just the pain of recurrent losses incurred for investing in dry wells, but also not to invest in contaminated waters. The study area is underlain by associated rock suites which includes pegmatite and quartz veins. Field data obtained was modeled and interpreted to obtain the geophysical parameters of the area and delineate the groundwater potential zones. Soil samples were also collected at the 22 VES points, at depths of 10 cm and 100 cm; the Global Positioning Satellite (GPS) equipment was used to obtain the geographical position of each sample point. Determination of the elemental composition of soil samples collected at the 10 cm and 100 cm depths was made using Atomic Absorption Spectrophotometer. Two heavy metals (Pb, and Cr), five major elements (K, Ca, N, P and Mg) and five trace elements (Zn, Mn, Cu, Al and Fe) were detected. It was observed that the values, representing the amount of the heavy metals, the major elements, and the trace elements were far less, mostly insignificant, at the 100 cm depth representing about the interface between the first and second layers in majority of the VES stations sampled, than at the 10 cm depth, representing the topsoil of the first layer. The implication of this is that the elements are not strictly domiciled within the area studied but may be due to runoffs as the area slopes down. Moreover, going by the values at the 100 cm depth, the elements may not be capable of percolating into the underground water zones in the area of study, and thus might not have contaminated the underground water. Thus, at the current level, the underground water can be adjudged safe for human consumption.ª¤

    NUMERICAL SOLUTION OF VOLTERRA INTEGRO-DIFFERENTIAL EQUATIONS BY AKBARI-GANJI’S METHOD

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    In this study, Akbari-Ganji’s Method (AGM) was applied to solve Volterra Integro-Differential Difference Equations (VIDDE) using Legendre polynomials as basis functions. Here, a trial solution function of unknown constants that conform with the differential equations together with the initial conditions were assumed and substituted into the equations under consideration. The unknown coefficients are solved for using the new proposed approach, AGM which principally involves the application of the boundary conditions on successive derivatives and integrals of the problem to obtain a system of equations. The system of equation is solved using any appropriate computer software, Maple 18. Some examples were solved and the results compared to the exact solutions

    Motion estimation of an aircraft model using computer vision

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    Dynamic wind tunnel tests are used to investigate the flight dynamics of aircraft. Currently contact measurement systems are used which increase friction and require on-board instrumentation. A vision-based method is proposed in this paper. The method uses a sequential process of Harris corner detection, Kanade-Lucas-Tomasi tracking, and Euler angles to identify the Euler angles from a pair of cameras, one with a top-view and the other with a side-view. The method is tested by simulating a 3D CAD model for a single degree of freedom rotational motion. The results have been quantified through numerical analysis and the proposed method is analysed analytically. The developed method is effective when integrated with another method of instrumentation such as an IMU

    Metabolic adaptation via regulated enzyme degradation in the pathogenic yeast Candida albicans

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    The virulence of Candida albicans is dependent upon fitness attributes as well as virulence factors. These attributes include robust stress responses and metabolic flexibility. The assimilation of carbon sources is important for growth and essential for the establishment of infections by C. albicans. Previous studies showed that the C. albicans ICL1 genes, which encode the glyoxylate cycle enzymes isocitratelyase are required for growth on non-fermentable carbon sources such as lactate and oleic acid and were repressed by 2% glucose. In contrast to S. cerevsiae, the enzyme CaIcl1 was not destabilised by glucose, resulting with its metabolite remaining at high levels. Further glucose addition has caused CaIcl1 to lose its signal and mechanisms that trigger destabilization in response to glucose. Another purpose of this study was to test the stability of the Icl1 enzyme in response to the dietary sugars, fructose, and galactose. In the present study, the ICL1 mRNAs expression was quantified using Quantitative Real Time PCR, whereby the stability of protein was measured and quantified using Western blot and phosphoimager, and the replacing and cloning of ICL1 ORF by gene recombination and ubiquitin binding was conducted via co-immuno-precipitation. Following an analogous experimental approach, the analysis was repeated using S. cerevisiaeas a control. Both galactose and fructose were found to trigger the degradation of the ICL1 transcript in C. albicans. The Icl1 enzyme was stable following galactose addition but was degraded in response to fructose. C. albicans Icl1 (CaIcl1) was also subjected to fructose-accelerated degradation when expressed in S. cerevisiae, indicating that, although it lacks a ubiquitination site, CaIcl1 is sensitive to fructose-accelerated protein degradation. The addition of an ubiquitination site to CaIcl1 resulted in this enzyme becoming sensitive to galactose-accelerated degradation and increases its rate of degradation in the presence of fructose. It can be concluded that ubiquitin-independent pathways of fructose-accelerated enzyme degradation exist in C. albicans

    Macroeconomic Reforms and Labour Market Performance: Evidence from Nigeria

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    The Nigerian government has introduced various macroeconomic reforms, policies and programmes that are not consistent and have not yielded the desired result, given the high unemployment rate. This study investigates macroeconomic reforms on labour market performance in pre and postreform eras using statistical analysis and Vector Error Correction Model. The findings show that using the ‘comparison of the mean employment ratio analysis’ between the pre-reform era and post-reform, the macroeconomic reforms targeting key variables have not promoted employment. More so, evidence from the long-run employment equation indicates that employment has a negative relationship with output in the long-run. However, the study shows joint long and short-run causality using employment as a dependent variable. Also, the forecast error shock from government expenditure affects output more than any other variable, with minimal employment effect. Mismanagement of resource is mainly an indicator of a fundamental weakness in policies and institutions. Therefore, to improve the situation, the study suggests that among others, strengthening fiscal capacities and institutions to ensure the restructuring of property rights and to ensure political stability regarding economic reforms.

    Demographic attributes of COVID-19 patients in an Infectious Disease Center of Nigeria

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    Background: As part of our contribution to the growing pool of knowledge on the prevention and control of the COVID-19 pandemic, this study describes the demographic features of patients with COVID-19 hospitalized at Infectious Disease Center (IDC), Olodo, Ibadan, Oyo State, Nigeria.Methodology: This was a descriptive cross-sectional study of COVID-19 patients whose data were collected during admission between April 27, 2020 and June 20, 2020. SARS-CoV-2 infection was diagnosed on nasopharyngeal specimen using a real-time reverse transcription–polymerase chain reaction (rRT-PCR) assay. Data were analysed using the Statistical Package for Social Sciences (SPSS Inc., USA) version 20.0Results: Among 131 patients, 58% were between age 18 and 35 years, 48.1% were employees of private establishments, and 64.1% were males. High proportion (84.3%) of the patients spent less than 14 days on admission. As at June 20, 2020, the overall COVID-19 mortality in the IDC was 0.0%.Conclusion: This study concluded that COVID-19 was common among male Nigerians, those working in private establishments, and those aged 18-35 years. Future researches on COVID-19 in Nigeria must put gender and age into consideration. Keywords: SARS-COV2; COVID-19; age; gender; occupation French Title: Attributs démographiques des patients atteints de COVID-19dans un centre de maladies infectieuses du Nigéria Contexte: Dans le cadre de notre contribution au pool croissant de connaissances sur la prévention et le contrôle de la pandémie COVID-19, cette étude décrit les caractéristiques démographiques des patients atteints de COVID19 hospitalisés au Centre des maladies infectieuses (IDC), Olodo, Ibadan, État d'Oyo, Nigéria. Méthodologie: Il s'agissait d'une étude transversale descriptive de patients atteints de COVID-19 dont lesdonnées ont été collectées lors de l'admission entre le 27 avril 2020 et le 20 juin 2020. L'infection par le  SRASCoV-2 a été diagnostiquée sur un échantillon nasopharyngé à l'aide d'une transcription inverse en temps réel–Test de réaction en chaîne par polymérase (rRT-PCR). Les données ont été analysées à l'aide du StatisticalPackage for Social Sciences (SPSS Inc., USA) version 20.0 Résultats: Parmi 131 patients, 58% avaient entre 18 et 35 ans, 48,1% étaient des employés d'établissementsprivés et 64,1% étaient des hommes. Une forte proportion (84,3%) des patients ont passé moins de 14 jours àl'admission. Au 20 juin 2020, la mortalité globale par COVID-19 dans l'IDC était de 0,0%. Conclusion: Cette étude a conclu que le COVID-19 était courant chez les hommes Nigérians, ceux travaillantdans des établissements privés et ceux âgés de 18 à 35 ans. Les futures recherches sur le COVID-19 au Nigériadoivent prendre en compte le sexe et l'âge. Mots clés: SRAS-COV2; COVID-19; âge; le sexe; occupatio
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