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Search Results: 1 - 10 of 277 matches for " Afolabi Ayeni "
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The Effects of Blends of Enugu Coal and Anthracite on Tin Smelting Using Nigerian Dogo Na Hauwa Cassiterite  [PDF]
Fatai Afolabi Ayeni, OladunniOyelola Alabi, Rose Okara
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2013, DOI: 10.4236/jmmce.2013.16052
Abstract: The effects of blending Enugu coal and anthracite on tin smelting using Nigerian Dogo Na Hauwa cassiterite have been studied. The work utilized various blends ranging from 100% to 0% anthracite. The content of the Enugu coal in the blend varied from 5% to 100%. The various tin metal recovery percentage for each batch of smelting using various blends was noted. Anthracite alone had the highest recovery of 71.90% followed by 5% blend of Enugu with anthracite. The result, however, showed that as the Enugu Coal was increased in the blend, the recovery was also decreasing. This equally affected the quality of tin metal recovered by increasing the grade. The work recommended that since the cost of production is the critical issue, 5% - 15% range of Enugu Coal should be used in preparing blends to bring down the cost of imported anthracite which is put at $906.69 per ton. The use of 15% Enugu coal will result in lowering the cost of imported anthracite by $136.0.
Evaluation of the Refractory Properties of Nigerian Ozanagogo Clay Deposit  [PDF]
Alexander Asanja Jock, Fatai Afolabi Ayeni, Abdulkarin Salawu Ahmed, Umar Adeiza Sullayman
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2013, DOI: 10.4236/jmmce.2013.16048
Abstract: In this paper, the refractory properties of clay from Ozanagogo had been studied for possible utilization in refractory production. The clay had a specific gravity of 2.57, linear firing shrinkage of 1.01%, 2.14 g/cm3 bulk density and porosity of 20.4%. A cold crushing strength of 17.48 MN/m2 was obtained with modulus of rupture of 8.28 MN/m2. The thermal shock resistance exceeded 30 cycles and the refractoriness was 1750℃. The sample was analysed for its chemical composition, and it was revealed that it contained 38.07% alumina (Al2O3), 46.00% silica (SiO2) and iron impurities (Fe2O3) of 0.78%. The results generally showed that Ozanagogo clay could be used as a refractory material.
Electrochemical Study of Redox Reaction of Various Gold III Chloride Concentrations in Acidic Solution  [PDF]
Afolabi Ayeni, Shafiq Alam, Georges Kipouros
Journal of Materials Science and Chemical Engineering (MSCE) , 2018, DOI: 10.4236/msce.2018.61009
Abstract: The redox reaction of gold III chloride in acid solutions has been electro-chemically investigated using a cyclic voltammetry technique. This paper emphasizes the current and potential sites at which gold III chloride is reduced in hydrochloric acid that is vital to electrochemical evaluation of gold recovery. The solutions were prepared by reacting HCl with AuCl3 in various concentrations thus 30 and 60 mg/L AuCl3 in 0.1 and 0.5 M HCl, respectively. Solutions of 0.1 and 0.5 M HCl containing 0, 30 and 60 mg/L AuCl3, respectively were tested for possible reduction and oxidation reactions by cyclic voltammogram experiment using a glassy carbon, a saturated calomel and a platinum wire mesh as working, reference and counter electrodes, respectively. The results showed no peak in the case of the absence of AuCl3 in the solutions, but appreciable cathodic and anodic peaks for the reduction and oxidation of various concentrations of AuCl3 in acid solutions. The reaction between AuCl3 and HCl was found to be reversible because the ratio of oxidation peak current and reduction peak current was 1. The concentration of AuCl-4 on the surface of the working electrode at the reduction site for each AuCl3 concentration using Nernst equation was 1.22 × 109 ppm and 2.44 × 109 ppm. The reduction potentials were independent of concentration, while the current was highly dependent of concentration.
New trends in under-five mortality determinants and their effects on child survival in Nigeria: A review of childhood mortality data from 1990-2008
Joshua O. Akinyemi,E. Afolabi Bamgboye,Olusola Ayeni
African Population Studies , 2013, DOI: 10.11564/27-1-5
Abstract: Under-five mortality in Nigeria has been reported to be on the decline, but the dynamics are yet to receiveadequate attention. Thus the main objective of this study was to assess these factors and quantify their relativecontributions to under-five mortality between 1990 and 2008. The Nigeria Demographic and HealthSurvey data for 1990, 2003 and 2008 were re-analysed to assess the trends in determinants of under-fivemortality.Cox Regression model was applied to determine the relative contributions of each factor to theunder-five mortality risk.The results showed there were improvements in maternal education (8.6%), childhoodvaccination (17.7%), use of oral rehydration therapy (13.9%) and medical treatment of childhood illnesses(17.5%) over the 19-year period. There were declines in proportions with birth interval less than 24months (3.9%), access to improved sources of drinking water (24.2%), improved toilet facilities (9.0%)antenatal care (4.5%), skilled delivery (3.0%) while maternal age at childbirth remained unchanged. Thesefactors increased the death hazards by 4.6% between 1990-2003 but decreased them by 12% between2003 and 2008. It was concluded that Nigeria has recorded very minimal improvements in birth spacing andantenatal/delivery care. Poor access to potable drinking water and sewage disposal, and short birth intervals,are among the factors fuelling childhood mortality risks. Further improvements in these environmental andhealth practices as well as other factors are recommended as strategies for promoting child survival inNigeria.
Institutional Collaboration as Essential Ingredient for Efficient and Effective Service Delivery: A Critical Focus on the Tripodic Super-bureaucracies and Bureaucrats in Ekiti State, Nigeria
Sunday Tunde Akindele,Oluwadare Ojo Ayeni,Yakibi Ayodele Afolabi
Journal of Politics and Law , 2012, DOI: 10.5539/jpl.v5n4p111
Abstract: This paper, using Ekiti State, Nigeria as a case study examines the issue of collaboration and its nexus with effective and efficient responsive service delivery to the citizenry. It takes off with a discussion of the relevant concepts that give both theoretical and practical expressions to the Offices of the SSG; HOS and; CSC vis-à-vis their coordinate relational partnerships. In the process, the deep-seated history; functions as well as the problems and challenges of these offices were concretely highlighted. While the benefits of collaboration among them were identified and critically examined, the need for the super-bureaucracies and bureaucrats in the state to create conducive atmospheres for the continuous sustenance of collaboration was stressed as the only avenue for the civil service to regain its lost glory and attain relevance in today’s global village in line with the ethos of public administration of the 21st century.
Investigation of Sida acuta (Wire Weed) Plant Extract as Corrosion Inhibitor for Aluminium-Copper-Magnessium Alloy in Acidic Medium  [PDF]
Fatai Afolabi Ayeni, Saheed Alawode, Dorcas Joseph, Patrick Sukop, Victoria Olawuyi, Temitope Emmanuel Alonge, Oladuuni Oyelola Alabi, Oluwakayode Oluwabunmi, Francis Ireti Alo
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2014, DOI: 10.4236/jmmce.2014.24033
Abstract: This work is an investigation of the aqueous corrosion inhibition of Al-Cu-Mg Alloy in acidic medium using extract of Sida acuta (wire weed) plant as corrosion inhibitor at 10%, 20%, 30% and 40% v/v of the extract. After exposing the alloy to the medium, the results showed that the plant extract inhibited the acid induced corrosion. The presence of Sida acuta plant extract reduces corrosion rate from 0.0012 to 0.0001 MPY and percentage protection increases from 37.42% to 93.63% within a ten-day period with increase in percentage volume of the extract. The result has clearly shown that Sida acuta plant extract can be used as a corrosion inhibitor in the part of chemical plant that is made of Al-Cu-Mg Alloy where acid is used for descaling and cleaning.
2k Factorial Experiments on Factors that Influence the Recovery of Gold during the Upgrade of Ilesha-Itagunmodi Gold Ore through Froth Flotation  [PDF]
Kayode Emmanuel Oluwabunmi, Abraham Adewale Adeleke, Adelana Razak Adetunji, Samson Olaitan Jeje, Abiodun Ayodeji Abioye, Olusola Adedayo Adesina, Fatai Afolabi Ayeni, Folahan Peter Ibitoye
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2014, DOI: 10.4236/jmmce.2014.21006
Abstract: A low-grade gold ore from Ilesha-Itagunmodi, south western Nigeria was panned, dried and ball-milled before sieving into fractions. The morphological, mineralogical and chemical composition was studied by optical micro-scopy (Reflected and Transmission), X-ray diffraction (XRD) and Energy Dispersive X-ray fluorescence (XRF), respectively. The sieved fractions were subjected to chemical analysis (AAS). The +106 μm sieve had the highest concentration of the mineral and was then selected for the upgrade through froth flotation using standard reagents. In this paper a report on a 2k factorial experiment that provides an understanding of the impact of operational variables on the quantity of gold mineral obtained from the ore during froth flotation is presented. Analysis results showed that Ilesha-Itagunmodi gold ore is non-refractory with fine grain particles, amenable to froth flotation and contained about 20 other associated minerals, gold had a concentration of about 0.0024%. A com-bination of P-Xanthate and amine glycol collectors at a pH of 9.2 only produced a considerable increase in gold yield. This translated to about 87.13% increase in recovery of gold from the ore. Analysis of variance (ANOVA) was carried out and the model equation obtained was subsequently optimised to obtain a model equation that could be used in predicting the recoverable quantity of gold, indicating that F11,1-values for Collector concentration, Frother concentration, pH and Conditioning time were 156.86, 6.96, 43.81, and 56.77 respectively. A model with an F value of 88.41 was obtained which indicated that the model was significant. The model equation obtained was subsequently optimised to be able to predict the recoverable quantity of gold. A “Pred R-Squared” value of 0.9365 (93.65%) was also obtained and is in reasonable agreement with the “Adj R-Squared” value of 0.9534 (95.34%). It was established that Ilesha placer gold ore is amenable to froth flotation using standard reagents.
Chemical qualities of oils from some fresh and market vegetable crops within Kwara State of Nigeria
IS Afolabi
Biokemistri , 2008,
Abstract: The potential of Nigeria leading Africa and the world in the area of biofuel and oleochemical production was examined by evaluating the oil yield and chemical qualities of oil extracted from fresh and market sample of some naturally abundant vegetables (Mangifera indica, Prunus dulcis Miller, Ricinnus communis, and Elaeis guineensis) in Nigeria. Moisture, ash, and crude fat composition, including the free fatty acid, acid and saponification values of the oils were determined, high mineral composition of almond was observed compared to other vegetables. Moisture content of 5.006, 3.500, 4.870, 37.002, 9.147, and 63.650%; crude fat of 59.195, 67.807, 33.490, 32.303, and 12.511, and 0.939%; and ash levels of 4.605, 2.833, 1.903, 1.728, and 1.305% were reported for seeds obtained from almond, castor, palm kernel, groundnut, mango and kola nuts respectively. Polymerization and esterification of fatty acids induced by the hot ambient storage conditions used by our marketer was attributed to the higher molecular weight of fatty acids in market sample for groundnut and palm oil over the corresponding fresh sample. High level of ash content (4.605%) for almond seed was observed, making a good source of mineral nutrition to consumers. Due to their high oil yield and abundance, oils from almond seed and castor seed, in addition to palm oil and groundnut oil may be considered as Nigeria potential asset for biofuel and oleochemical production.
Status of clean gene (selection marker-free)technology
AS Afolabi
African Journal of Biotechnology , 2007,
Abstract: The ever-increasing world population has created two major problems: more mouths to feed and less land to farm. While classical breeding has enormously helped in providing more food, a lot still needs to be done. Transformation biotechnology can also help especially where classical breeding lacks solution (e.g. limited availability of stable and durable genetic source of resistance). However, plant transformation technologies require selectable marker genes to produce transgenic plants but such genes are of no value thereafter; in fact, marker genes in transgenic plants are perceived to pose potential bio-safety problems. In all genetic transformation technologies based on direct gene transfer (electroporation of protoplasts, particle bombardment etc) the selectable marker genes generally cointegrate with the gene of interest(s) in one Mendelian locus in the plant genome; hence, their removal is highly desirable. This may also help in the acceptability of transgenic plants by society. Transgenic plants that contain the desired gene of interest but lack the selection marker gene used in its production are termed “clean” and the methods utilized in their production are referred to as “clean gene” technology. There are several proved methods of eliminating selectable marker genes and these include: (A) Marker gene excision consisting of (1) intra-genomic relocation of transgenes via transposable elements, (2) site-specific recombination systems and (3) intra-chromosomal recombination. (B) Gene replacement or Targeted gene replacement; and (C) transformation with multiple T-DNAs, which could result in linked and/or unlinked co-integration of transgenes. Unlinked transgenes are then segregated out during meiosis.
The preservative efficacies of bemul-wax coatings in combination with calcium chloride dip on low temperature stored Citrus O. sinensis
IS Afolabi
Biokemistri , 2009,
Abstract: The capacity of developing countries for citrus fruits exportation is limited by the lack of adequate storage techniques. In studying this problem citrus sinensis Osbeck was treated with, a locally developed bemul-wax, calcium chloride dip, and a combination of the two. The treated fruits were assessed during four month low temperature storage (7.0 ± 3.0oC; 90-94% RH.) for their biochemical and sensory qualities. Fruits treated with bemul-wax and the combination manifested significantly reduced (p<0.05) physiological weight, delayed ripening, and texture values. All the treated oranges showed significantly reduced titratable acidity. Combined treatment significantly reduced (p<0.05) ascorbic acid level, while the combined and calcium chloride dip treatments reduced, and increased significantly (p<0.05) the density of the juice respectively. All treatments showed significantly increased (p<0.05) pH and -amylase activities but no effects on total sugar levels, pectin esterase activities, taste and flavor of the juice. In conclusion, the combined and bemul-wax treatments preserved the nutritional, biochemical, and sensory qualities of the stored oranges for the four month storage period considered adequate to cover the orange off-season period in Nigeria as well as sufficient to export orange from Nigeria to other parts of the world.
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