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Search Results: 1 - 10 of 32506 matches for " Peter Olusola Adewale "
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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.
Effect of Carboxylmethyl Cellulose Coating and Osmotic Dehydration on Freeze Drying Kinetics of Apple Slices
Jamshid Rahimi,Ashutosh Singh,Peter Olusola Adewale,Akinbode A. Adedeji,Michael O. Ngadi,Vijaya Raghavan
Foods , 2013, DOI: 10.3390/foods2020170
Abstract: The effect of different concentrations of sugar solution (hypertonic) (30%, 45% and 60% w/v) and carboxyl methyl cellulose (CMC) (0%, 1% and 2% w/v) coating on freeze drying of apple slices was studied. In total, nine treatments with respect to concentrations of hypertonic solution and coating layer were prepared to analyze their influence on the physical and chemical properties of freeze dried apple slices. It was observed that increase in the sugar solution concentration, decreased the moisture content of the apple slices significantly impacting its water activity, texture and sugar gain. Application of different concentrations of CMC coating had no significant effect on the properties of dried apple slices. A significant change was observed for color of CMC coated freeze dried apple slices pretreated with 60% sugar solution. Drying kinetics of pretreated apple slices were fitted by using two drying models, Newton’s and Page’s. Page’s model showed higher R-square and lower root mean square error (RSME) compared to Newton’s model.
Palynostratigraphy and Paleoclimate of the Sequences Penetrated by Meren 31 Side Tract-2 Well, Offshore Niger Delta  [PDF]
Peter S. Ola, Bamisile K. Adewale
International Journal of Geosciences (IJG) , 2014, DOI: 10.4236/ijg.2014.510100
Abstract: Palynological study of an offshore well in the Niger delta was carried out to document the palynomorphs assemblage and subsequently date and establish paleoclimatic conditions in a portion of the Niger delta. One hundred and thirty seven cutting samples provided by Chevron Nigeria Plc were composited at 27 m interval for the study. The samples yielded forty six palynomorphs, which include Racemonocolpites hians, Zonocostites ramonae, Monoporites annulatus, Botryococcusbraunii, dinocyst Lycopodiumsporites spp., Pachydermitesdiederixi and Psilatricolporitescrassus. A Middle-Late Miocene age belonging to P800 and P700 zones of Germeraad was established for the interval studied. There were clear crests and troughs in the microfloral abundance indicative of alternations of dry and wet climatic conditions during the deposition of the Agbada Formation.
Comparative Antioxidant, Phytochemical and Proximate Analysis of Aqueous and Methanolic Extracts of Vernonia amygdalina and Talinum triangulare
God`swill Nduka Anyasor,Kayode Olusola Ogunwenmo,Adewale Ayodele Ogunnowo,Olabisi Alao-Sanni
Pakistan Journal of Nutrition , 2010,
Abstract: This study evaluated and compared in vitro antioxidant activity, phytochemical constituent and proximate analysis of aqueous and methanolic leaf extracts of Vernonia amygdalina and Talinum triangulare to determine their acceptability in folkloric medicine. The total phenolic content of aqueous and methanolic extracts of V. amygdalina (0.822±0.050 and 0.681±0.050 mg gallic acid equivalent GAE/g respectively) was higher than aqueous and methanolic extract of T. triangulare (0.456±0.040 and 0.288±0.020 mg GAE/g respectively). Furthermore, DPPH scavenging activity of V. amygdalina was significantly higher (p<0.05) than T. triangulare at all levels of concentration (100, 200 and 300 μg/ml). Lipid peroxidation was inhibited by all samples, although there was no significant difference (p>0.05). Aqueous extracts of leaf tested positive to tannin, phlobatannins, cardiac glycosides, saponins, phenols, flavonoids and alkaloids. The proximate composition of V. amygdalina leaf showed higher percentage crude fibre, fat, protein and total carbohydrate content than T. triangulare except moisture and ash contents. Methanolic and aqueous leaf extracts of V. amygdalina possess higher antioxidant properties, phyto-nutrients and longer shelf life than T. triangulare and hence it’s pervading use and acceptability in folkloric and trado-medicine.
Evaluation of the Influence of Fossil Fuel on Corrosion Resistance of Brass  [PDF]
Olayide Rasaq Adetunji, Peter Olaitan Aiyedun, Sidikat Ibiyemi Kuye, Dauda Adewale Lateef
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2014, DOI: 10.4236/jmmce.2014.23022
Abstract: Brass is an excellent material choice for use in most industrial and agricultural application. Brass offers much better thermal conductivity and corrosion resistance than carbon or even stainless steel. Brass is an excellent material for use in both hot and cold water industrial and residential system including those carrying portable water. This study was carried out to investigate and evaluate the influence of fossil fuel like petrol, kerosene and diesel on the corrosion performance of brass. The samples were prepared for the study by cutting brass into 1 cm2 coupons and soaking them in different small plastic containers containing petrol, kerosene and diesel. The corrosion rate of each sample for a specific period of immersion (120, 240, 360, and 480, 600 and 720 hours) was determined on average of three samples exposed under the same condition and test media in different container. The finding showed that brass is resistant to corrosion after long hours of contact in chosen liquid fossil fuels. Brass has the highest corrosion rate in petrol, followed by kerosene and least in diesel. The photomicrographs of the samples after ten days of immersion also confirmed this.
Synthesis and Characterization of a Heteroleptic Ru(II) Complex of Phenanthroline Containing Oligo-Anthracenyl Carboxylic Acid Moieties
Adewale O. Adeloye,Peter A. Ajibade
International Journal of Molecular Sciences , 2010, DOI: 10.3390/ijms11093158
Abstract: In an effort to develop new ruthenium(II) complexes, this work describes the design, synthesis and characterization of a ruthenium(II) functionalized phenanthroline complex with extended π-conjugation. The ligand were L 1 (4,7-bis(2,3-dimethylacrylic acid)-1,10-phenanthroline), synthesized by a direct aromatic substitution reaction, and L 2 (4,7-bis(trianthracenyl-2,3-dimethylacrylic acid)-1,10-phenanthroline), which was synthesized by the dehalogenation of halogenated aromatic compounds using a zero-valent palladium cross-catalyzed reaction in the absence of magnesium-diene complexes and/or cyclooctadienyl nickel (0) catalysts to generate a new carbon-carbon bond (C-C bond) polymerized hydrocarbon units. The ruthenium complex [RuL 1L 2(NCS) 2] showed improved photophysical properties (red-shifted metal-to-ligand charge-transfer transition absorptions and enhanced molar extinction coefficients), luminescence and interesting electrochemical properties. Cyclic and square wave voltammetry revealed five major redox processes. The number of electron(s) transferred by the ruthenium complex was determined by chronocoulometry in each case. The results show that processes I, II and III are multi-electron transfer reactions while processes IV and V involved one-electron transfer reaction. The photophysical property of the complex makes it a promising candidate in the design of chemosensors and photosensitizers, while its redox-active nature makes the complex a potential mediator of electron transfer in photochemical processes.
Synthesis and Characterization of a Ru(II) Complex with Functionalized Phenanthroline Ligands Having Single-Double Linked Anthracenyl and 1-Methoxy-1-buten-3-yne Moieties
Adewale O. Adeloye,Peter A. Ajibade
Molecules , 2010, DOI: 10.3390/molecules15117570
Abstract: Two series of bidentate polypyridine ligands, made of phenanthroline chelating subunits having substituted mono-and di-anthracenyl groups, and 1-methoxy-1-buten-3-yne at the 4 and 7-positions with the corresponding heteroleptic Ru(II) complex have been synthesized and characterized. The complex is formulated as [(Ru(L1)(L2)(NCS)2)], (where L1 = 4-(9-dianthracenyl-10-(2,3-dimethylacrylic acid)-7-(9-anthracenyl-10-(2,3-dimethylacrylic acid)-1,10-phenanthroline and L2 = 4,7-bis(1-methoxy-1-buten-3-yne)-1,10-phenanthroline). The Ru(II) complex shows characteristic broad and intense metal-to-ligand charge transfer (MLCT) bands absorption and appreciable photoluminescence spanning the visible region. The ligands and complex were characterized by FT-IR, 1H, 13C NMR spectroscopy, UV-Vis, photoluminescence and elemental analysis (see in supplementary materials). The anchoring groups in both ligands have allowed an extended delocalization of acceptor orbital of the metal-to-ligand charge-transfer (MLCT) excited state.
A High Molar Extinction Coefficient Mono-Anthracenyl Bipyridyl Heteroleptic Ruthenium(II) Complex: Synthesis, Photophysical and Electrochemical Properties
Adewale O. Adeloye,Peter A. Ajibade
Molecules , 2011, DOI: 10.3390/molecules16064615
Abstract: In our quest to develop good materials as photosensitizers for photovoltaic dye-sensitized solar cells (DSSCs), cis-dithiocyanato-4-(2,3-dimethylacrylic acid)-2,2'-bipyridyl-4-(9-anthracenyl-(2,3-dimethylacrylic)-2,2'-bipyridyl ruthenium(II) complex, a high molar extinction coefficient charge transfer sensitizer, was designed, synthesized and characterized by spectroscopy and electrochemical techniques. Earlier studies on heteroleptic ruthenium(II) complex analogues containing functionalized oligo-anthracenyl phenanthroline ligands have been reported and documented. Based on a general linear correlation between increase in the length of π-conjugation bond and the molar extinction coefficients, herein, we report the photophysical and electrochemical properties of a Ru(II) bipyridyl complex analogue with a single functionalized anthracenyl unit. Interestingly, the complex shows better broad and intense metal-to ligand charge transfer (MLCT) band absorption with higher molar extinction coefficient (λmax = 518 nm, e = 44900 M?1cm?1), and appreciable photoluminescence spanning the visible region than those containing higher anthracenyl units. It was shown that molar absorption coefficient of the complexes may not be solely depended on the extended π-conjugation but are reduced by molecular aggregation in the molecules.
Hybrid Online Labs: Making Remote Laboratories Usable Under Unfavorable Bandwidth Conditions
Kayode Peter Ayodele,Lawrence O. Kehinde,Olusola A. Komolafe
International Journal of Online Engineering (iJOE) , 2012, DOI: 10.3991/ijoe.v8i4.2158
Abstract: One of few limitations of remote laboratory technology is the fact that access and usability of such laboratories depend largely on the existence of favorable bandwidth conditions between the remote user and the system under test. This dependence is regrettable because some of the institutions likely to find remote laboratories attractive are also those most likely to have severe bandwidth limitations. Also, a typical remote laboratory will be completely unusable to remote students in the event of an outright network downtime. In this paper, we propose a hybrid online laboratory architecture that allows the automatic generation of accurate software models of remote laboratories. Such models can be hosted closer to the student and during periods of unfavorable bandwidth conditions, students can successfully interact with such models in lieu of the real hardware. We identify the challenges that need to be resolved for such a scheme to be useful and discuss the process by which suitable modeling bases were chosen. Finally we present and discuss data from a first test of the system and conclude that such a scheme holds considerable promise in changing the way remote laboratories are used and viewed.
Assessment of liver function, bile secretory rate and liver histological changes in type 1 diabetes mellitus rats treated with ocimum gratissimum
Okon Akpan Uduak, Peter Imo Aniekan, Esther Olusola Aluko
Asian Journal of Medical Sciences , 2015, DOI: 10.3126/ajms.v6i3.9960
Abstract: Background: The liver plays an important role in nutrient metabolism and alterations in the liver function, biliary secretion and cytoachitecture are common in diabetes mellitus (DM). Aim: Ocimum gratissimum (OG) has been reported to exert hypoglycaemic effect in DM, the need to assess the impact of its treatment on these diabetic complications became imperative. Material and Methods: Phytochemical and toxicity test were conducted. Eighteen rats into three groups of six rats each were used. Group 1 was the control and given normal feed only. Group 2 was diabetic untreated rats (DM) while group 3 was OG treated diabetic rats (DMT) at a dose of 1500 mg/kg. All groups had access to food and water ad libitum. After 28 days, serum was obtained for analysis of Alkaline phosphatase (ALP), Alanine aminotransferase (ALT) and Aspartate aminotranferase (AST). The bile content was collected at 3 hours interval to determine the bile secretory rate. Routine biopsy method was employed for histological studies. Results: Results showed that AST in the DM and DMT groups were significantly higher (P < 0.001) than the control group; DM was significantly higher (P < 0.001) than the DMT. ALT and ALP levels in DM and DMT groups were significantly (P < 0.001) higher than the control; DM was significantly higher (P < 0.001) than DMT. Conclusion: There was structural and functional hepatic impairment in DM. OG treatment appears to effectively ameliorate these complications including enhancement of bile secretion. DOI: http://dx.doi.org/10.3126/ajms.v6i3.9960 Asian Journal of Medical Sciences Vol.6(3) 2015 16-21 ?
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