156 research outputs found
Thinlayer Chromatography (TLC) and GC-MS Analysis of Somes Medicinal Plants Used in the Treatent of Haemorrhoids
Medicinal plant is one in which, one or more of its organs contains substances that can be used for therapeutic purposes or which are precursors for the synthesis of useful drugs The present study aimed at investigating the lipid composition of Axonopus compressus, Anogeiessus leiocarpus and Senna fistula commonly used in the management of haemorrhoids. The lipid analysis of the three plants was determined by TLC and GC-MS and the GC-MS analysis revealed the presence of some saturated fatty acids such as myristic, palmitic, linoleic, stearic, oleic and lauric acid in all the three extracts. In addition A. compressus contained linoleic and palmitoleic acids, S. fistula contained linolenic acid and A. leiocarpus contained linoleic, linolenic and behenic acids. However, palmitic (C16:0)) and stearic acid (C18:0) were observed to be the predominant fatty acids present in all the three plan extracts. The results showed that many active principles are present in the three plants which could contribute to their usefulness in the management of haemorrhoids. Keywords: Haemorrhoids,Medicinal plants,lipids, TLC,GC-M
Effect of frozen period on the chemical, microbiological and sensory quality of frozen tilapia fish (Sarotherodun galiaenus)
The study was designed to investigate the effect of duration of frozen storage on the chemical, microbiological and sensory profile of Tilapia fish (Sarotherodun galiaenus) collected from a research pond of the Agricultural Development Project, Akure, Nigeria and were subjected to sixty days of frozen storage and analyzed at intervals of ten days. Protein content (%) ranges from 43.70 ± 1.17-60.65 ± 2.40. Protein decreases with increasing duration of frozen storage with the fresh samples (not frozen) having the highest protein content (60.65 ± 2.40) while the least (43.70 ۫.17) was recorded for fish samples that were frozen for sixty days. Similar results were obtained for the fat content (%) where the highest fat content (9.72 ± 0.25) was recorded for the fresh samples and the least value was recorded for those stored for sixty days. Ash content (%) and moisture content (%) do not show any significant change during storage. Mineral composition (Fe, Ca, Mg, P and Zn in mg/100g) and iodine content (µg/100g) of the samples showed a slight change with respect to duration of storage. pH values ranges between 5.20-6.90 while the total coliform count range was between 3.0 x103-7.5 x 106 with increasing values, as the duration of torage increases. Sensory evaluation of the fish samples on storage revealed that quality of the fish samples with respect to taste decreases with increasing duration of storage with the best quality (texture, odor and color) when freshly prepared; and that better quality during storage is obtainable during the first ten days of storage. These, by implication simply mean that fish should be stored for a short period of time to retain the taste, and provide both the protein and fat at optimal level. Key words: Frozen period, chemical, microbiological, sensory quality, tilapia fish.African Journal of Biotechnology Vol. 4 (8), pp. 852-85
Analysis of heat absorption viscoelastic exothermic chemical reactive fluid with temperature dependent viscosity under bimolecular kinetic
This study examines the boundary layer flow of variable viscosity, incompressible exothermic chemical reactive fluid with thermal radiation and asymmetric convective cooling under Bimolecular kinetic. The viscoelastic fluid flow along a vertical channel in the presence of a thermal buoyancy force and pressure gradient. Rosseland approximation is defined for the thick radiation heat flux in the energy equation with gray radiating liquid, non-scattering but with heat absorbing depending on wavelength. The convective heat exchange with the sorrounding temperature at the channel surface satisfied Newton’s law of cooling. The computational analysis of the dimensionless nonlinear governing equations is obtained using Weighted residual method (WRM). The solutions are employed to obtain the velocity field, energy profile, skin friction and Nusselt number of the flow. These are graphically presented and discussed to show the effect of some pertinent fluid parameters on the non-Newtonian liquid flow. It is observed that the heat source reaction terms need to be cautiously monitored and controlled to avoid reaction solution blow up
Variable Viscosity and Thermal Conductivity Effect of Soret and Dufour on Inclined Magnetic Field in Non-Darcy Permeable Medium with Dissipation
The analysis of thermal-diffusion (Soret) and diffusion-thermo (Dufour) effects on variable thermal conductivity and viscosity in a dissipative heat and mass transfer of an inclined magnetic field in a permeable medium past a continuously stretching surface for power-law difference in the concentration and temperature are examined. The flow is incompressible with the thermal conductivity and fluid viscosity are assumed to be temperature dependent. The local similarity variables for various values of the parameters are considered for the momentum, heat and mass equations. The dimensionless equations are solved numerically using fourth order Runge-Kutta scheme coupled with shooting method. It was noticed that an increase in the values of m enhances the temperature profiles as heat moves from the plate surface to the ambient medium when 0fm, otherwise it flows away from the medium to the stretching sheet. Finally, the influences of Skin friction, Nusselt and Sherwood numbers are also presented and discusse
Mineral Profile of \u3ci\u3ePanicum maximum\u3c/i\u3e var. Ntchisi as Influenced by Organic Nitrogen Rate and Age at Harvest
The study was aimed at profiling the mineral contents of Panicum maximum var Ntchisi as influenced by organic (poultry) nitrogen rate and age at harvest. The study was carried out at the organic research farm of the Federal University of Agriculture, Abeokuta, Nigeria in 2016. The experiment was laid in a 4 x 3 factorial arrangement in a split plot design with four (4) organic nitrogen rate (0, 100, 200 and 300 kgNha-1) as the main plot and three (3) age at harvest (4, 8 and 12 weeks after cutback) as the subplot which amounts to twelve (12) treatment combinations with four replicates. The macro mineral contents were significantly (P\u3c 0.05) influenced by the nitrogen rate. The calcium (Ca) content was up to 4.35 gkg-1DM for the grass at 0 KgNha-1 which was the highest value. The magnesium (5.59 – 8.43 gkg-1DM) content had a linear increment with increased nitrogen rate. The potassium content ranged from 15.58 to 30.80 gkg-1 DM with the grass fertilized at 0 KgNha-1 having the highest K content. The phosphorus was linearly (P\u3c 0.05) influenced with the grass fertilized at 300 KgNha-1 with the highest (1.78 gkg-1DM) content. The micro mineral contents were significantly (P\u3c 0.05) influenced by the nitrogen rate though without a definite pattern. The macro and micro mineral contents were significantly (P\u3c 0.05) influenced by age at harvest except for the copper content. The macro mineral contents decreased with advancement in age at harvest. It was concluded that the grass harvested at younger age will make a good feed resource in terms of mineral requirement of ruminants in the tropics
Approximation of the Cox survival regression model by MCMC Bayesian hierarchical Poisson modelling of factors associated with childhood mortality in Nigeria
The need for more pragmatic approaches to achieve sustainable development goal on childhood mortality reduction necessitated this study. Simultaneous study of the influence of where the children live and the censoring nature of children survival data is scarce. We identified the compositional and contextual factors associated with under-five (U5M) and infant (INM) mortality in Nigeria from 5 MCMC Bayesian hierarchical Poisson regression models as approximations of the Cox survival regression model. The 2018 DHS data of 33,924 under-five children were used. Life table techniques and the Mlwin 3.05 module for the analysis of hierarchical data were implemented in Stata Version 16. The overall INM rate (INMR) was 70 per 1000 livebirths compared with U5M rate (U5MR) of 131 per 1000 livebirth. The INMR was lowest in Ogun (17 per 1000 live births) and highest in Kaduna (106), Gombe (112) and Kebbi (116) while the lowest U5MR was found in Ogun (29) and highest in Jigawa (212) and Kebbi (248). The risks of INM and U5M were highest among children with none/low maternal education, multiple births, low birthweight, short birth interval, poorer households, when spouses decide on healthcare access, having a big problem getting to a healthcare facility, high community illiteracy level, and from states with a high proportion of the rural population in the fully adjusted model. Compared with the null model, 81% vs 13% and 59% vs 35% of the total variation in INM and U5M were explained by the state- and neighbourhood-level factors respectively. Infant- and under-five mortality in Nigeria is influenced by compositional and contextual factors. The Bayesian hierarchical Poisson regression model used in estimating the factors associated with childhood deaths in Nigeria fitted the survival data.Publisher PDFPeer reviewe
Optimization of Absorber Layer and Operating Temperature of Copper Indium Gallium Selenide Solar Cells Using Different Metal Contacts
Device simulation was employed to investigate the effect of metal back contact electrodes on the performance of n-type CdS/p-CIGS thin film solar cells using varying thicknesses of absorber layer at operating temperature of 300K. The effect of working temperatures was also studied from 300K to 400K in steps of 10K. The simulations were carried out using standard solar cell capacitance simulator (SCAPS) 3.3.03 version software. The results showed better efficiencies at the optimized thickness of 3µm for all the back contact electrodes under study. The maximum efficiencies of 17.5 %, 15.5 %, 11.5 %, 3.5 % and 3 % were estimated for CIGS thin film solar cell at 300 K for platinum, gold, cobalt, silver and copper back contact electrodes respectively. The efficiency decreases as the operating temperatures increases from 300 K to 400 K. It is recommended that the optimized thickness of 3 µm is appropriate as absorber layer for efficient and cost effective CIGS thin film solar cells for economic reasons
Accessing the Impact of E-Learning on Tertiary Education Management Amidst the Global Wave of Covid -19 Pandemic in Nigeria: Issues and Prospects
Tertiary education is an important tool for jumpstarting development in almost all nations of the world. It serves as a lever for other sectors of the economy, with far-reaching imperativeness aimed at economic, technological, and governmental growth. The unfortunate outbreak of Coronavirus in 2019 has had devastating effects on every sector of the economy, from which tertiary education is not exempted. E-learning naturally becomes an option in order to grapple with and cope with the changes occasioned by the outbreak of the COVID-19 pandemic. This study is an attempt to logically investigate the nature and dynamics of the challenges pursued by the adoption of the e-learning method as an avenue for coping with the enormous challenges associated with the effective delivery of tertiary education in emergencies. This is more expedient because e-learning has become a veritable tool for the global advancement of tertiary education. Mixed date method research was employed in the conduct of this research, and a sum of fourth (40) forms was distributed to the target audience, and the hypothesis was tested using chi-square. The findings of the study reveal that e-learning has aided the continuation of education amidst the SARS-19. The paper recommends that both stakeholders in the private and public education sectors of Nigeria should provide conducive e-learning facilities amidst and beyond covid -19 pandemic in Nigeria
Damage identification in a concrete beam using curvature difference ratio
Previous studies utilising changes in mode shape or curvature to locate damage rely on the fact that the greatest change occurs around the defect. However, in concrete beams this fact is undermined due to the nature of the defect as distributed multi-site cracks. In addition, differences in mode shape and curvature as ways to locate the damage is unstable because of occurrence of modal nodes and inflection points. In this paper, one interesting solution to this problem is being tested by establishing a new non-dimensional expression designated the 'Curvature Difference Ratio (CDR)'. This parameter exploits the ratio of differences in curvature of a specific mode shape for a damaged stage and another reference stage. The expression CDR is reasonably used to locate the damage and estimate the dynamic bending stiffness in a successively loaded 6m concrete beam. Results obtained by the proposed technique are tested and validated with a case study results done by Ren and De Roeck [1] also by Maeck and De Roeck [2]. Another contribution of this work is that relating changes in vibration properties to the design bending moment at beam sections as defined in Eurocode 2 specifications [3]. Linking between a beam section condition and the change in vibration data will help to give a better comprehension on the beam condition than the applied load
Material Selection and Processing Techniques: Crucial Factors for Gear Engineering
Gear drives are susceptible to consistent wear due to repeated cyclic stress around the teeth while in the application. The repeated cyclic loadings have effects on the tribological performance of the components. Also, the downtime data from bottling plants showed that there is a significant increase in gear failure, which resulted in maintenance costs. The contact between a pair of gear in the mesh is complex, which leads to several failure modes like; micropitting, scuffing, micro pitting, and wear as a result of rotation. Materials formed the fundamental elements in which production/manufacturing processes depend on. The selection of materials for high-quality manufacturing depends significantly on the complicated relationship between their properties and manufacturing techniques. Recently, great varieties of materials and processing techniques are available to a gear designer. However, the choice of material and processing methods at a minimized cost poses a challenge to gear designers. In the present study, the importance of material selection and processing methods towards efficient gear design and transmission have been enumerated. Failures associated with materials and processing techniques have also been established as well as the methods of improving the mechanical properties. It is expected that the adoption of the highlighted findings into gear design would result in a reduction of failures and efficient gear transmission
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