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Engineering（科研） 2015年第7期7卷 434-445页

作者： Joseph Babalola agboola Oladiran Abubakre Kamardeen Edeki Mudiare Michael Bolaji Adeyemi Department of Mechanical Engineering Federal University of Technology Minna Nigeria

Theoretical analysis of the effects of velocity of impact using suitable heat transfer equations expressed in forms of finite difference method was developed and used to determine their effects on the characteristic cooling parameters during quenching process. Various velocities of impact obtained by varying the heights of specimen drops were also used to experimentally determine their effects on characteristic cooling parameters and mechanical properties of medium carbon steel using water as the quenching medium. At height of drop of 0.5 m, 1.0 m, 1.5 m, and 2.0 m, the tensile strength of the material is 410.4, 496.12, 530.56, and 560.40 N/mm2 respectively. The corresponding hardness values are 42.4, 45.2, 46.2, 50.5 HRC respectively. It is found that as the velocity of impact increases, maximum cooling rate increases. Hardness and ultimate tensile strength also increase. There are good agreements between theoretical and experimentally determined values of critical cooling parameters of water during quenching operations.

关键词： Quenching Modeling Velocity Impact Mechanical Properties Steel

Assessment of Activity Concentration of Radionuclides in Sediment from Oil Producing Communities of Delta State, Nigeria

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Journal of Environmental Protection 2015年第6期6卷 640-650页

作者： Caroline Nihinlola Iwetan Ibiyinka agboola Fuwape Adeseye Muyiwa Arogunjo Ganiyu Obor Physics Department Federal University of Technology Akure Nigeria Biochemistry Department Federal University of Technology Akure Nigeria

Activity concentrations of twenty-six (26) samples of sediment collected from rivers from eleven (11) oil-producing communities and two (2) non-oil producing communities in Delta state of Nigeria were studied. Hyper Purity Germanium (HPGe) Detector was used for counting and detection of radionuclide content of all samples. Results of the samples analysed showed that the radioactivity concentrations of K40, Th232 and U238 in the sediment samples from oil-producing areas range from 32.47 Bq·kg-1 to 525.1 Bq·kg-1 with an average of 302.15 Bq·kg-1, 6.31 Bq·kg-1 to 19.33 Bq·kg-1 with an average of 11.66 Bq·kg-1, and 4.45 Bq·kg-1 to 18.69 Bq·kg-1 with an average of 8.66 Bq·kg-1 respectively. Activity concentrations at the control site ranged from 3.15 Bq·kg-1 to 4.80 Bq·kg-1, 2.27 Bq·kg-1 to 4.18 Bq·kg-1 and 1.15 Bq·kg-1 to 1.76 Bq·kg-1 for K40, Th232 and U238. These values are within the world average;natural radioactivity mapping of the study area is carried out using the Surfer software. Statistical analysis of the results showed that there is a significant difference between the radionuclide concentrations of the sediment samples from rivers in the oil producing site compared to results from non-oil producing communities, except for one of the oil producing site samples (Idumuesah) which has values that are close to those from the control sites for K40. The values of the radiological assessment indices obtained were observed to be within the permissible maximum values;hence the radiation hazard at study areas are negligible. However, concentration values of studied radionuclide at the oil-producing study areas were observed to be higher than values from the non-oil producing sites in most cases. It could therefore be reported that the operations of the oil companies in Delta state of Nigeria may have contributed to the high radioactivity level of the river sediments. Although the concentration at the time of this study poses no risk, further industrial activities in t

关键词： Sediment Natural Radioactivity TENORM HPGe Detector

Fundamentals of electric circuits 影印版

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Chemical composition and antimicrobial activities of essential oil extracted from Tithonia diversifolia(Asteraceae)flower

丛书名：国际知名大学原版教材

2000年

作者： Charles K. Alexander Matthew N. O. sadiku

Reprint. Originally published: Boston : McGraw-Hill, c2000.

ISBN: (纸本)7900630988

Reprint. Originally published: Boston : McGraw-Hill, c2000.

关键词： Electric circuits.

来源：畅想之星图书光盘版（南... 畅想之星图书光盘版（南... 评论

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Journal of Bioresources and Bioproducts 2016年第4期1卷 169-176页

作者： Oludare O.agboola Stephen Oyedeji Joshua O Olowoyo Abdulwakeel Ajao Oladipo Aregbesola Department of Biology Sefako Makgatho Health Sciences UniversityPretoriaSouth Africa. Department of Botany University of LagosAkokaYabaLagos StateNigeria. Department of Plant Biology University of IlorinIlorin240003 Nigeria. Department of Botany Obafemi Awolowo UniversityIle-IfeOsun StateNigeria Department of Microbiology Obafemi Awolowo UniversityIle-IfeOsun StateNigeria

The upsurge in the prevalence of side effects of many synthetic antimicrobial agents and incidence of multidrug resistant bacteria has spurred scientists on the search for plant based antimicrobial of therapeutic *** study extracted essential oils from the flowers of Tithonia diversifolia(Hemsl)***(Mexican sunflower)and assayed it for antimicrobial *** oils were extracted(hydro-distillation),characterized(GC-MS)and tested for antibacterial and antifungal activities.α-Pinene(34.42%),β-Caryophyllene(22.34%),β-Pinene(11.14%),Germacrene-D(11.13%)and 1,8-Cineole(8.76%)were the major constituents of the forty-five compounds *** characterized compounds were general monoterpenes(44.44%),sesquiterpenes(26.67%),including alcohols and aldehydes which accounted for 28.89%.The extract concentrations of 8-120 mg/ml in Potato Dextrose Agar(PDA)medium effectively inhibited the tested fungi in *** 5 mg/ml,only Bacillus megaterium and Bacillus cereus were inhibited of all gram-positive bacteria while Streptococcus pyrogens was *** gram-negative bacteria were *** inhibition of the gram-positive and gram-negative species increases with increased concentration of the essential *** 40 mg/ml,all the tested bacteria species were inhibited and the growth inhibition for the species followed the order;***>Proteus mirabi>Bacillus megaterium>Klebsiella pneumonia>Bacillus cereus>*** oil concentration of 72 mg/ml totally inhibited the growth of all three fungal species-Cochliobolus lunatus,Fusarium solani,Fusarium *** secondary metabolites in the oil of *** proved effective against the tested bacteria and fungi *** finding of this study unlocks the potentials of this essential oil of Mexican sunflower for bio-pesticide production.

关键词： Essential oils Flower Gas chromatography Monoterpenes Sesquiterpenes

Probing the Dynamics of Primary Science Classrooms in Nigeria in Relation to Pupils＇ Interest in Science

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Psychology Research 2014年第8期4卷 635-650页

作者： Tunde Owolabi Peter A. Okebukola Jimmy Avoseh Wasiu Otun Ojo sadiku Sunday O. Banjoko Lagos State University Lagos USA

Seminal Fluid Characteristics of Men Attending Infertility Clinic of a Teaching Hospital

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Open Journal of Medical Microbiology 2013年第1期3卷 1-4页

作者： Festus Abiose Olajubu Deji-agboola Mope Olubunmi Adetokunbo Osinupebi Olusoji Edward Jagun Department of Medical Microbiology & Parasitology Obafemi Awolowo College of Health Sciences Olabisi Onabanjo University Sagamu Nigeria Department of Medical Microbiology & Parasitology Obafemi Awolowo College of Health SciencesOlabisi Onabanjo University Sagamu Nigeria Department of Medical Microbiology & Parasitology Olabisi Onabanjo University Teaching Hospital Sagamu Nigeria Department of Obstetrics and Gynaecology College of Health Sciences Olabisi Onabanjo University Sagamu Nigeria

The semen quality of 479 men in infertile marriages, who attended the infertility clinic of OOUTH, Sagamu between May 2004 and April 2009 were analyzed. The semen samples were physically examined, microscopically analyzed and aerobically cultured. The result showed that out of 51.5% oligospermic cases recorded, 39.8% could be classified severe. Cryptozoospermia were diagnosed in 72 (15%) cases. Bacteriospermia and Necrozoospermia were found in 149 and 6 cases respectively. The predominant organism isolated was Staphylococcus aureus (50.32%) while Neisseria gonorrhoea was isolated in only 2 cases. Highest infection of 62.4% was noticed among the group with 1% - 19% motility. From the studied population, 8.8% were azoospermic. The commonest morphological defects were pin and ragged heads (48%). It is therefore obvious that the assessment of semen quality remains one of the important steps in infertility interventions.

关键词： Sperm Concentration OOUTH Infertile Marriages Motility Bacteriospermia

Markov Chain Monte Carlo Solution of Laplace’s Equation in Axisymmetric Homogeneous Domain

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Open Journal of Modelling and Simulation 2019年第4期7卷 203-216页

作者： Adebowale E. Shadare Matthew N. O. sadiku Sarhan M. Musa Department of Electrical/Computer Engineering Prairie View A&M University Prairie View TX USA

With increasing complexity of today’s electromagnetic problems, the need and opportunity to reduce domain sizes, memory requirement, computational time and possibility of errors abound for symmetric domains. With several competing computational methods in recent times, methods with little or no iterations are generally preferred as they tend to consume less computer memory resources and time. This paper presents the application of simple and efficient Markov Chain Monte Carlo (MCMC) method to the Laplace’s equation in axisymmetric homogeneous domains. Two cases of axisymmetric homogeneous problems are considered. Simulation results for analytical, finite difference and MCMC solutions are reported. The results obtained from the MCMC method agree with analytical and finite difference solutions. However, the MCMC method has the advantage that its implementation is simple and fast.

关键词： Laplace’s Equation Axisymmetric Problem Inhomogeneous Dirichlet Boundary Conditions Markov Chain Monte Carlo (MCMC)

Agricultural Sector and HIV/AIDS Pandemic in Africa: The Economic Retrogression Model

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Agricultural Sciences 2016年第4期7卷 206-224页

作者： Temidayo Gabriel Apata Moshood Olatunde Oladapo Adetunji Lawrence Kehinde Olasimbo Motunrayo Apata Timothy Olusola agboola Department of Agricultural Economics & Extension Federal University Oye-Ekiti Oye-Ekiti Nigeria Department of Agricultural Economics & Extension Osun State University Ejigbo Campus Ejigbo Nigeria Department of Agricultural Economics & Extension Ekiti State University Ado Ekiti Nigeria

Objective: Agricultural activities in most African countries demand human labour, the supply of labour to agriculture may be threatened if humans could no longer farm because of HIV/AIDS pandemic. Past studies have identified the alarming situation and challenges the spread of HIV/AIDS endemic poses to human existence and agricultural growth. Examining these interactions, and their direction, is useful for informing policy directives. Therefore, the general objective of this study is to examine interactions between HIV/AIDS pandemic and agricultural growth in Africa using a model of retrogression. Methods: Twenty countries in Africa identified as HIV/AIDS ravaged countries were taken as the areas of study. These countries are spread over four zones of the Northern Africa, the Eastern, the Southern and the Sub-Saharan Africa. A combination of analytical tools was employed to meet the study objectives. Results: The results revealed that long run economic cost of HIV/AIDS had a statistical positive significant relationship with agricultural/economic growth. The results suggest that there is a curvilinear relationship between the course of the HIV/AIDS epidemic and agricultural/economic growth in terms of human capita development. Conclusions: HIV/AIDS pandemic interactions and agricultural growth have demonstrated that a more balanced approach is necessary for effective policy.

关键词： HIV/AIDS Plague Human Capita Development Risky Sex Etiquette Agricultural Policy Africa

A Comparison Study of Phenolic Contents and <i>in Vitro</i>Antioxidant Activities of Australian Grown Faba Beans (<i>Vicia faba</i>L.) Varying in Seed Coat Colours as Affected by Extraction Solvents

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American Journal of Analytical Chemistry 2019年第6期10卷 227-245页

作者： Siem Doo Siah Samson agboola Jennifer A. Wood Izabela Konczak Christopher L. Blanchard Graham Centre for Agricultural Innovation Wagga Wagga Agricultural Institute Wagga Wagga Australia Australian Export Grains Innovation Centre (AEGIC) North Ryde NSW Australia School of Biomedical Sciences Charles Sturt University Wagga Wagga Australia Food Futures Flagship CSIRO Animal Food and Health Sciences North Ryde NSW Australia School of Agricultural and Wine Sciences Charles Sturt University Wagga Wagga Australia Tamworth Agricultural Institute NSW Department of Primary Industries Calala Australia Food Science and Technology School of Chemical Sciences and Engineering University of New South Wales Sydney Australia ARC Industrial Transformation Training Centre for Functional Grains Charles Sturt University Wagga Wagga NSW Australia

Twelve Australian grown faba bean genotypes with seed colour ranging from white, different shades of buff/beige, green, red and purple, were extracted using 80% methanol (v/v) or 70% acetone (v/v). The findings showed that commonly consumed buff-coloured genotypes have comparable phenolic contents and antioxidant activities to those with exotic seed coat colour (red, green and purple). In general, the extraction yield for methanol and acetone extracts of faba bean genotypes were similar. However, the acetone extracts of faba bean varieties with coloured seed coats exhibited higher antioxidant activities than their methanol extracts counterparts. Phenolic compounds and antioxidant activities of the genotypes were compared in an array of chemical-based assays and profiled using an on-line high-performance liquid chromatography-post column derivatization (HPLC-PCD) system. The total phenolic content (TPC) and total flavonoid content (TFC) of acetone extracts were approximately twice those of methanol extracts. The acetone extracts contained six times higher levels of di(phenyl)-(2,4,6-trinitrophenyl) imi- noazanium radical scavenging activity (DPPH), six times higher Total Equivalent Antioxidant Capacity (TEAC) and two times higher Ferric Reducing Antioxidant Power (FRAP) than those of methanol extracts. In general, the methanol extracts of white-coloured faba bean genotype exhibited comparable phenolic contents and antioxidant activities to varieties with coloured seed coats. However, the TPC, TFC, DPPH, TEAC and FRAP of acetone extracts from white-coloured genotype were 2 - 4, 1 - 2, 5 - 9, 2 - 3 and 1 - 2 times lower than those of faba bean varieties with coloured seed coats. HPLC-PCD analyses showed substantial antioxidant responses, represented as a dense “hump” of peaks in the HPLC chromatograms of acetone extracts from coloured-genotypes. This “hump” was not detected in the chromatograms of white-genotype acetone extracts, or in chromatograms of methanol extract

关键词： Vicia faba Extraction Solvent Phenolic Compound Antioxidant

Performance Assessment of Selected Nigerian Vegetable Oils as Quenching Media in Hardening Process for Medium Carbon Steel

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Journal of Minerals and Materials Characterization and Engineering 2015年第2期3卷 85-93页

作者： Joseph Babalola agboola Oladiran Abubakre Kamardeen Edeki Mudiare Michael Bolaji Adeyemi Samuel Ayo Afolabi Department of Mechanical Engineering Federal University of Technology Minna Nigeria Department of Civil and Chemical Engineering University of South Africa (Unisa) Johannesburg South Africa

A comparative study was carried out to investigate the suitability of some selected Nigerian vegetable oils as alternative quenchant to SAE40 engine oil for industrial heat treatment of Medium Carbon steels. The study involved the characterization of physicochemical properties and fatty acid profile of cotton seed oil, palm kernel oil, neem seed oil and palm oil. The quenching performance of these vegetable oils was conducted at quenchant bath temperatures of 34oC, 50oC, 70oC, and 100oC. SAE40 engine oil (Standard quenchant) and tap water served as control. The effect of cooling rates of the quenching media on mechanical properties and microstructure of the quenched steel samples were investigated. The results obtained show that the different vegetable oils have different viscosity and viscosity-temperature behavior just as their molecular structures were different. The mechanical properties of the as-quenched specimens in these oils show that the hardness of steel quenched in palm kernel oil was highest 40.85HRC. As received sample absorbed the highest amount of energy (183 J) before fracture while sample quenched in water absorbs least energy (28 J). Hence vegetable oil is suitable as alternative quenchant to petroleum based SAE40 engine oil for quenching medium carbon steels, without cracking or distortion, the most suitable among them being palm kernel oil.

关键词： Quenching Vegetable Oil Fatty Acid Mechanical Properties Microstructure