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Quantification of Metal Contaminants and Risk Assessment in Some Urban Watersheds

Journal of Water Resource and Protection 2020年第11期12卷 951-963页

作者： Adeleke Adeniyi Olumuyiwa Okedeyi Mutiu Sowemimo Kafeelah Yusuf ojo oluwole Bernadine Ejiogu Iyabode Ajibade Bamitale Fabiyi Olubunmi Adeniji Department of Chemistry Lagos State University Ojo Lagos Nigeria Department of Biochemistry Lagos State University Ojo Lagos Nigeria Centre for Environmental Studies and Sustainable Development (CESSED) Lagos State University Ojo Lagos Nigeria

Contamination by heavy metals is a serious threat to aquatic systems due to their level of toxicity at elevated levels. The pollution of urban watersheds is of particular concern because of its potential impact on the watershed ecosystem and the receiving larger water bodies. This study assessed the occurrence and distribution of cadmium, copper, nickel, lead and zinc in water and sediment samples collected from three urban watersheds in Lagos, Nigeria. The concentrations of metals were determined using atomic absorption spectrometry. The health risk index (HRI) of water usage was evaluated for both adults and children. HRI for cadmium and lead in some of the watersheds recorded HRI > 1 values, a cause for health concern. The pH of water ranged from 6.48 ± 0.28 - 6.54 ± 0.47 (2016) and 6.18 ± 0.56 - 6.53 ± 0.17 (2018) respectively while, for sediments, the pH values ranged from 6.14 ± 0.48 - 6.9 ± 0.15 and 5.38 ± 0.22 - 6.4 ± 0.38 for 2016 and 2018 respectively. The levels of metals in the water samples during the 2016 sampling cycle were found to be within the World Health Organization (WHO) guideline limits for drinking water. However, the 2018 cadmium, lead and zinc concentrations for Ira-Ipaye and Akesan watersheds exceed the WHO guideline limits. Cadmium was not detected in Ira-Ipaye and Akesan 2016 sediment samples. Statistical t-test and analysis of variance (ANOVA) were used to ascertain significant differences of metals concentration in the three watersheds. The pH and metal concentration values obtained for water and sediment for the year 2016 and 2018 were non-significantly different.

关键词： Metals Cadmium Lead Watersheds Health Risk

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Quantification of Metal Contaminants and Risk Assessment in Some Urban Watersheds

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Journal of Water Resource and Protection 2020年第11期

作者： Adeleke Adeniyi Olumuyiwa Okedeyi Mutiu Sowemimo Kafeelah Yusuf ojo oluwole Goodluck Odili Bernadine Ejiogu Iyabode Ajibade Bamitale Fabiyi Olubunmi Adeniji

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Effect of functional composite coating developed via sulphate and chloride process parameter on the UNS G10150 steel for structural and wear mitigation in defence application

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Defence Technology（防务技术） 2018年第3期14卷 196-203页

作者： ojo Sunday Isaac Fayomi Department of Mechanical Engineering Covenant University Department of Chemical Metallurgical and Materials Engineering Tshwane University of Technology

The major engineering challenge of materials in defence technologies is the vulnerability of based metals to structural and wears deformation in service. In this paper, structural formation, mechanical and thermal stability behavior of developed composite coating of Zn-30 Al-7%Ti/Sn chloride bath and Zn-30 Al-7%Ti/Sn sulphate bath was investigated and compared to provide mitigation against failure. The thermal ageing property was done for 2 h at 600C via isothermal furnace. The structural, interfacial effect and stability behaviors of the co-deposited alloys were evaluated using scanning electron microscope equipped with energy dispersive spectrometer(SEM/EDS), atomic force microscope(AFM) and Xray diffractometer(XRD). The hardness and wear properties of the deposited coatings were examined with diamond base micro-hardness tester and reciprocating sliding tester respectively. The result shows that Zn-30 Al-7%Ti/Sn sulphate co-deposition contributed to increase hardness and wear resistance than Zn-30 Al-7%Ti/Sn chloride bath alloy. The stable crystal growth and significant performance of Zn-30 Al-7%Ti/Sn sulphate are link to the intermetallic phase hybrid of Zn Al, Zn4 Ti Al2, Zn3 Al Ti. Besides, it was observed that Zn-30 Al-7%Ti/Sn sulphate has excellent thermomechanical stability at harsh temperature,due to the deposition of Sn/Ti on steel; leading to formation of super-hard interface. However, it was established that co-deposition of mild steel with Zn-30 Al-7%Ti/Sn in sulphate bath significantly improved the structural and wear performance. It was shown that the hardness and wear of the developed composite Zn-30 Al-7%Ti/Sn is increased by about 80% compared to as received sample and about 25% compared with Zn-30 Al-7%Ti/Sn chloride coating developed. The improvement was proved to be an interference of zinc-composite growth. Thus, this work shows that sulphate induced Zn-30 Al-7%Ti/Sn via generation of controllable process parameter can provide significant improv

关键词：防卫技术硫酸盐氯化物低碳钢结构涂层合成 UNS

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Additive manufacturing of 18%nickel maraging steels:Defect,structure and mechanical properties:A review

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Journal of Materials Science & Technology 2022年第25期120卷 227-252页

作者： Lulu Guo Lina Zhang Joel Andersson Olanrewaju ojo Department of Mechanical Engineering University of ManitobaWinnipeg R3T 5V6Canada Department of Engineering Science University WestTrollh tan 46186Sweden

This paper reviews the latest research progress in the additive manufacturing(AM)process of 18%nickel maraging steels,which involves laser-based powder bed fusion(L-PBF),laser-based directed energy deposition(L-DED),and wire arc additive manufacturing(WAAM).The emphasis is on the defects,structure,and mechanical properties of the additive manufactured 18%nickel maraging *** first,this article outlines the influences of the processing parameters of AM techniques on the defects formed in the fabricated parts,in terms of the L-PBF and *** macrostructure and microstructure characteristics of as-built and heat-treated 18%nickel maraging steel are then described in ***,the mechanical properties of as-built and heat-treated 18%nickel maraging steel are assessed,such as their tensile,hardness,impact toughness,and fatigue ***,future directions for work on the AM of 18%nickel maraging steel are provided.

关键词： Additive manufacturing 18%Nickel maraging steel Defects Macrostructure Microstructure Mechanical properties

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Defence Technology（防务技术） 2021年第2期17卷 531-544页

作者： Gui-ju Zhang Cai-yuan Xiao Olatunj Oladimeji ojo Key Laboratory of Hunan Province for Efficient Power System and Intelligent Manufacturing Shaoyang422000HunanChina College of Mechanical and Energy Engineering Shaoyang UniversityShaoyang422000HunanChina Department of Industrial and Production Engineering Federal University of Technology AkureAkureNigeria

This paper studies the friction stir spot welding of AA2024-T3/AA7075-T6 Al alloys in the ambient and underwater environments by clarifying the nugget features,microstructure,fracture and mechanical properties of the *** results show that the water-cooling medium exhibits a significant heat absorption capacity in the AA2024-T3/AA7075-T6 welded *** features such as stir zone width,circular imprints,average grain sizes,and angular inter-material hooking are reduced by the watercooling effect in the *** whitish(intercalated structures)bands are formed in the underwater joints while Mg2Si and Al2CuMg precipitates are formed in the ambient and the underwater welded joints *** increase in tool rotational speed(600e1400 rpm)and plunge depth(0.1 e0.5 mm)increases the tensile-shear force of the welded AA2024-T3/AA7075-T6 joints in both the ambient and underwater *** maximum tensile-shear forces of 5900 N and 6700 N were obtained in the ambient and the underwater welds respectively.

关键词： Friction stir spot welding Underwater friction stir spot welding Nugget characterization Microstructure Mechanical properties Fracture

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Anti-Corrosion and Tribo-Mechanical Properties of Co-deposited Zn–SnO_2 Composite Coating

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Acta Metallurgica Sinica(English Letters) 2015年第4期28卷 521-530页

作者： ojo Sunday Isaac Fayomi Abimbola Patricia Idowu Popoola Department of Chemical Metallurgical and Materials EngineeringTshwane University of Technology Department of Mechanical Engineering Covenant University

Zn-SnO2 composite coatings were prepared by direct potential using electrolytic co-deposition technique from sulfate solution. The effect of Zn2＋ and SnO2 concentrations in deposited bath on the mechanical properties and mor- phological characteristics of the composite coatings were examined. The characterizations of the sample were analyzed using scanning electron microscopy couple with energy dispersive spectroscopy （SEM/EDS）, X-ray diffraction （XRD） and atomic force microscopy （AFM）. The electrochemical degradation behavior of the samples in 3.65 wt.% NaCl solution was studied using potentiodynamic polarization technique and characterized by high-resolution optical microscope. From all the fabricated composite coatings, obvious diffraction peaks were observed with Zn-7Sn-S-0.3V film with Zn2Sn7, Sn, Zn2Sn5 and Zn phases, confirming the presence and formation of Zn-SnO2 coating. The XRD pattern shows that the presences of SnO2 particle remarkably play a major role in the precipitation and orientation of the alloy matrix. From the SEM/EDS and AFM results, the deposits show that composite particle and proper bath composition have strong influence on the microstructure. An enhanced corrosion resistance was attained as a result of the induced particles.

关键词： Metal matrix composite Co-deposition Mechanical property Corrosion resistance

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Re-Evaluation of Bovine Fiber Biomass as Exploitable Keratinous Bio-Resource for Biomedical and Industrial Applications

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Journal of Minerals and Materials Characterization and Engineering 2017年第1期5卷 1-17页

作者： Isiaka oluwole Oladele Jimmy Lolu Olajide Oluyemi ojo Daramola Kofi Bismarck Siaw Department of Metallurgical and Materials Engineering Federal University of Technology Akure Nigeria African Materials Science and Engineering Network (AMSEN) A Carnegie-IAS (RISE) Network (FUTA Node) Akure Nigeria Department of Mechanical Engineering Elizade University Ilara-Mokin Nigeria Division of Computational Materials Science and Prototype Engineering Development Quantum Simutech Enterprise Ilorin Nigeria

In claim of developing ecologically-friendly and low cost polymeric materials, some polymer scientists and engineers have focused on improving the properties of polymer composites with natural fibers. One typical example of these natural fibers currently used as reinforcements in low load-bearing polymer composites is bovine fiber which is traditionally a waste from slaughterhouse. However, nature has designed natural fibers with anisotropic properties which may not augur well for the development of polymer composites with guaranteed field-proven reliability. Nonetheless, unlike vegetal fibers, most animal fibers can be alternatively exploited for keratinous applications. In the present study, the tensile properties, crude protein contents and variations in elemental distribution of hair fibers obtained from three breeds of bovine found in Nigeria were investigated. The hair fibers were characterized by ultimate testing machine, proximate analysis and scanning electron microscopy with energy dispersive X-ray spectroscopy. Superlative Young’s modulus and tensile strength among the fibers were found to be 0.98989 GPa and 0.56158 MPa, respectively. The determined crude protein contents of the fibers ranged between 35% and 40%. Also, single hair fibers from each bovine breed showed significant variations in elemental distribution along their longitudinal sections which translates to anisotropic chemical and mechanical properties. However, the mean spectral values of the principal elements that constitute amino acids in the fibers are in the same range with that of human hair fibers with a successful record of keratinous applications.

关键词： Biological Materials Keratin Sources Fiber Chemistry Natural Fibers Ecological Welfare

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Friction stir welding of pure magnesium and polypropylene in a lap-joint configuration: Microstructure and mechanical properties

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International Journal of Minerals,Metallurgy and Materials 2019年第6期26卷 766-774页

作者： Amirhossein Moghanian Moslem Paidar Seyyed Salman Seyedafghahi Olatunji Oladimeji ojo Department of Materials Engineering Imam Khomeini International UniversityQazvin 34149-16818Iran Department of Material Engineering South Tehran BranchIslamic Azad UniversityTehran 14598-53849Iran Department of Engineering Faculty of Materials Science and EngineeringImam Hossein UniversityTehran 15816-18711Iran Department of Industrial and Production Engineering Federal University of Technology AkureAkurePMB 704Nigeria

A hybrid joint with a satisfactory mixture of pure magnesium and polypropylene(PP)was achieved via friction stir joining(FSW)in a lap-joint *** tool rotational and travel speeds used in this work were 500–700 r/min and 50–100 mm/min,*** mechanical properties and microstructural analysis of the resultant hybrid Mg/PP joint were *** results show that the maximum tensile shear strength(22.5 MPa)of the joint was attained at 700 r/min and 75 mm/min due to the optimum percentage fraction of mechanical interlocking(48%)and the presence of magnesium *** interfacial joint center exhibits the maximum microhardness values because of the presence of refined and intertwined Mg fragments and density dislocations in the matrix of the *** joint failed via two different modes:interfacial line and weld zone fractures,respectively.

关键词： welding microstructure pure magnesium polypropylene rotational speed

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Therapeutic potential of rutin in male infertility:A mini review

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Journal of Integrative Medicine 2023年第2期21卷 130-135页

作者： Damilare Emmanuel Rotimi Tobiloba Christiana Elebiyo Oluwafemi Adeleke ojo SDG 03 Group–Good Health&Well-being Landmark UniversityOmu-Aran 251101Kwara StateNigeria Department of Biochemistry Landmark UniversityOmu-Aran 251101Kwara StateNigeria Phytomedicine Molecular Toxicologyand Computational Biochemistry Research Laboratory(PMTCB-RL)Department of BiochemistryBowen UniversityIwo 232101Osun StateNigeria

Male infertility has become a problem worldwide,and recent research has emphasized the development of more effective therapy *** natural compounds,rutin has been widely studied for its potential to treat dysfunction related to male infertility,including a reduction in sperm quality,spermatogenesis disruption and structural disruption in the testis.A thorough review of scientific literature published in several databases,including Google Scholar,PubMed/MEDLINE and Scopus,was used to synthesize the present state of research on the role of rutin in male reproductive *** has been shown to possess antiapoptotic,antioxidant and anti-inflammatory activities,among others,which are crucial in the management of male *** investigations have shown that rutin protects against male infertility and have explored the underlying mechanisms *** present review,therefore,assesses the therapeutic mechanisms involved in male infertility treatment using *** was able to mitigate the induced oxidative stress,apoptosis,inflammation,and related physiological processes that can cause testicular dysfunction.

关键词： Antioxidant Inflammation Rutin Sperm Testicularfunction

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Diabetes self-management education:Benefits and challenges

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Journal of Integrative Nursing 2023年第2期5卷 93-101页

作者： Ibironke Cecilia ojo Elizabeth Olufunmilayo ojo Simeo Kayode OLUBIYI Department of Nursing College of Medicine and Health ScienceAfe Babalola UniversityAdo-EkitiEkiti StateNigeria

Diabetes mellitus has spread throughout many nations of the world and is now a serious threat.A lack of patient self‑management has been linked to this drain on global *** consequences of diabetic patients’poor self‑management have increased a variety of complications and lengthened hospital *** information and skill acquisition have been linked to poor self‑*** in a co‑operative approach known as diabetes self‑management education will help diabetes patients who want to successfully self‑manage their condition and any associated *** is one of the most important components of a diabetes management *** conclusion,numerous studies have shown that patients with diabetes have poor self‑management skills and knowledge in all areas,making training in diabetes self‑management necessary to minimize the complications that may result from diabetes mellitus among the *** review discussed the severity of diabetes mellitus,diabetes self‑management,and the benefits and challenges of diabetes self‑management,which may aid individuals in understanding the significance of diabetes self‑management and how it relates to diabetes self‑care.

关键词： Diabetes diabetes self‑care diabetes self‑management diabetes self‑management education and support education

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