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Journal of Minerals and Materials Characterization and Engineering 2024年第2期12卷 91-99页

作者： Oluwole Oladele ayodele adedeke Olajesu Olanrewaju Samuel Olusunle Department of Metallurgical and Materials Engineering Federal University of Technology Akure Ondo State Nigeria Engineering Materials Development Institute NASENI Akure Ondo State Nigeria Department of Materials Science and Engineering Iowa State University Ames IA USA NASENI Abuja Nigeria

This research considered the effect of non-natural aging on the microstructural characteristics and mechanical properties of as-cast aluminum 6063 alloys. The samples were developed through a sand casting process and machined into tensile and impact test samples before carrying out solution heat treatment at 550?C (0.83 Tm) on two parts of the samples while retaining one part as the control. The two parts were further divided into sets denoted A and B and were aged at 180?C (0.27 Tm) and 160?C (0.24 Tm), respectively, for 12 hours. The results showed that sample A has the optimal yield strength and ultimate tensile strength of 192 and 206 MPa, respectively. Likewise, the sample gave the highest impact strength value of about 9.63 J/mm2. The observed results were supported by the optical micrograph, which revealed that the sample has evenly dispersed precipitates in its microstructure. This is deemed responsible for the observed increase in strength of the sample.

关键词： Aluminum Alloy Non-Natural Ageing Mechanical Properties Microstructural Features

Modulation effects of Cu modification and ligands (oxalate and borohydride) functionalization on Pt d-band center, upper d-band edge, and alloyed PtCe support acidity on semihydrogenation of acetylene

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Journal of Energy Chemistry 2022年第9期31卷 495-508,I0014页

作者： Olumide Bolarinwa ayodele International Iberian Nanotechnology Laboratory Braga 4715-330Portugal Department of Civil and Chemical Engineering University of Tennessee ChattanoogaTN 37403United States

The modulating effects of Cu modification and oxalate or borohydride ligands functionalization on the structure,catalyst d-band center(εd),upper d-band edge(εu),and acetylene partial hydrogenation of expediently synthesized Ce alloyed Pt supported catalysts were ***,a 5 wt%Pt alloyed Ce was synthesized via flame spray *** PtCe sample was further supported on zeolite Y,ZY,(PtCe/ZY)and copper modified ZY(PtCe/Cu-ZY).Furthermore,the PtCe was supported on two other oxalate and borohydride ligands functionalized copper modified ZY(PtCe/CuX-ZY and PtCe/CuB-ZY,respectively).The high-angle annular darkfield scanning transmission electron microscopy(HAADF/STEM)data showed a reduction in the PtO average particle size from 2.65 nm in PtCeO_(2) to average 1.73,0.64,and 0.30 nm in PtCe/Cu-ZY,PtCe/CuX-ZY,and PtCe/CuB-ZY,which was corroborated by the electron energy-loss spectroscopy(EELS)results wherein nonhomogeneous mixing of elements was seen with segregated Pt clusters in the non-functionalized ***,both PtCe/CuX-ZY and PtCe/CuBZY samples showed near-perfect homogeneity with no distinct Pt *** measuredεu values for PtCe,PtCe/Cu-ZY,PtCe/CuX-ZY,and PtCe/CuB-ZY are+1.85,+0.40,-0.15,and-0.19 eV,*** positive values indicated strong metal-adsorbate bonding typical of large Pt sizes while the negative values indicated weak metal-adsorbate bonding due to highly downsized Pt *** ethylene yield(YC2H4)over the PtCe sample showed depletion as the reaction temperature increased,while it reflected maxima at 120℃ with 55.3%YC2H4 over PtCe/*** maxima shifted to 180℃ with enhanced YC2H4 of 71.4%in PtCe/*** the contrary,both PtCe/CuX-ZY and PtCe/CuB-ZY exhibited a monotonous increase in YC2H4 up to the maximum C_(2)H_(2)conversion with YC2H4 of 81.9%and 92.1%at 180 and 160℃,*** results showed that both the Cu modification and ligands functionalization were highly invaluable to enhance the properties and

关键词： Acetylene Semihydrogenation Ethylene Pt d-band center Upper d-band edge

Interactive Effect of Blackeye cowpea mosaic virus and Cucumber mosaic virus on Vigna unguiculata

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Horticultural Plant Journal 2019年第2期5卷 88-92页

作者： ayodele Anthony Fajinmi Faculty of Agriculture Department of Crop Science and Horticulture Federal UniversityOye-Ekiti P.M.B. 374 Nigeria

This research tries to demonstrate physiological effect of combined infection of two viruses on growth parameter of cowpea plant as demonstrated through symptom expression. Blackeye cowpea mosaic virus(BlCMV) and Cucumber mosaic virus(CMV) were transmitted to cowpea plants by mechanical rub inoculation. This study showed that the differences in stem height and final aboveground fresh weight of cowpea plants inoculated with mixed infection with CMV and BlCMV were significantly less than those of plants inoculated with a single virus. Likewise cowpea plants inoculated with either virus alone or with CMV and BlCMV mixed infection had less stem height and aboveground fresh weight than the control. The mixed infection of BlCMV and CMV caused significant increase in the severity of symptoms in cowpea and also in the height using factors analysis and Abbott's equation. Symptom severity rating scale used, demonstrated statistical proof for physiological effect based on symptom severity for co-infection. A three phase disease symptom severity expression revealed disease severity for each viral treatment associated with host plant.

关键词： cowpea virus mixed infection interaction severity symptom

Catalysis of semihydrogenation of acetylene to ethylene: current trends, challenges, and outlook

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Frontiers of Chemical Science and Engineering 2022年第7期16卷 1031-1059页

作者： Toyin D.Shittu Olumide B.ayodele Department of Chemical and Petroleum Engineering United Arab Emirates UniversityAl-Ain 15551United Arab Emirates Department of Micro and Nanofabrication International Iberian Nanotechnology LaboratoryBraga 4715-330Portugal School of Chemical Engineering Engineering CampusUniversity of Science MalaysiaNibong Tebal 14300Malaysia

Ethylene is an important feedstock for various industrial processes, particularly in the polymer industry. Unfortunately, during naphtha cracking to produce ethylene, there are instances of acetylene presence in the product stream, which poisons the Ziegler–Natta polymerization catalysts. Thus, appropriate process modification, optimization, and in particular, catalyst design are essential to ensure the production of highly pure ethylene that is suitable as a feedstock in polymerization reactions. Accordingly, carefully selected process parameters and the application of various catalyst systems have been optimized for this purpose. This review provides a holistic view of the recent reports on the selective hydrogenation of acetylene. Previously published reviews were limited to Pd catalysts. However, effective new metal and non-metal catalysts have been explored for selective acetylene hydrogenation. Updates on this recent progress and more comprehensive computational studies that are now available for the reaction are described herein. In addition to the favored Pd catalysts, other catalyst systems including mono, bimetallic, trimetallic, and ionic catalysts are presented. The specific role(s) that each process parameter plays to achieve high acetylene conversion and ethylene selectivity is discussed. Attempts have been made to elucidate the possible catalyst deactivation mechanisms involved in the reaction. Extensive reports suggest that acetylene adsorption occurs through an active single-site mechanism rather than via dual active sites. An increase in the reaction temperature affords high acetylene conversion and ethylene selectivity to obtain reactant streams free of ethylene. Conflicting findings to this trend have reported the presence of ethylene in the feed stream. This review will serve as a useful resource of condensed information for researchers in the field of acetylene-selective hydrogenation.

关键词： selectivity hydrogenation acetylene ethylene palladium

Biochar-Induced Changes in Soil Resilience:Effects of Soil Texture and Biochar Dosage

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Pedosphere 2017年第2期27卷 236-247页

作者： ayodele Ebenezer AJAYI Rainer HORN Department of Agricultural and Environmental Engineering Federal University of Technology 340252 Akure Ondo State (Nigeria) Institute for Plant Nutrition and Soil Science CAU Kiel 24118 Kiel (Germany)

Biochars are, amongst other available amendment materials, considered as an attractive tool in agriculture for carbon sequestration and improvement of soil functions. The latter is widely discussed as a consequence of improved physical quality of the amended ***, the mechanisms for this improvement are still poorly understood. This study investigated the effect of woodchip biochar amendment on micro-structural development, micro-and macro-structural stability, and resilience of two differently textured soils,fine sand(FS) and sandy loam(SL). Test substrates were prepared by adding 50 or 100 g kg^(-1) biochar to FS or SL. Total porosity and plant available water were significantly increased in both soils. Moreover, compressive strength of the aggregates was significantly decreased when biochar amount was doubled. Mechanical resilience of the aggregates at both micro-and macro-scale was improved in the biochar-amended soils, impacting the cohesion and compressive behavior. A combination of these effects will result in an improved pore structure and aeration. Consequently, the physicochemical environment for plants and microbes is improved. Furthermore, the improved stability properties will result in better capacity of the biochar-amended soil to recover from the myriad of mechanical stresses imposed under arable systems, including vehicle traffic, to the weight of overburden soil. However, it was noted that doubling the amendment rate did not in any case offer any remarkable additional improvement in these properties, suggesting a further need to investigate the optimal amendment rate.

关键词： aggregate stability amendment material compressive strength rheometry shear properties total porosity

A Cuckoo Search Detector Generation-based Negative Selection Algorithm

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Computer Systems Science & Engineering 2021年第8期38卷 183-195页

作者： ayodele Lasisi Ali M.Aseere Department of Mathematical Sciences Faculty of ScienceAugustine UniversityIlara-EpeLagosNigeria Department and College of Computer Science King Khalid UniversityAbhaKingdom of Saudi Arabia

The negative selection algorithm(NSA)is an adaptive technique inspired by how the biological immune system discriminates the self from *** asserts itself as one of the most important algorithms of the artificial immune system.A key element of the NSA is its great dependency on the random detectors in monitoring for any ***,these detectors have limited *** detectors are generated,leading to difficulties for detectors to effectively occupy the non-self *** alleviate this problem,we propose the nature-inspired metaheuristic cuckoo search(CS),a stochastic global search algorithm,which improves the random generation of detectors in the *** characteristics such as mutation,crossover,and selection operators make the CS attain global *** the use of Lévy flight and a distance measure,efficient detectors are *** results show that integrating CS into the negative selection algorithm elevated the detection performance of the NSA,with an average increase of 3.52%detection rate on the tested *** proposed method shows superiority over other models,and detection rates of 98%and 99.29%on Fisher’s IRIS and Breast Cancer datasets,***,the generation of highest detection rates and lowest false alarm rates can be achieved.

关键词： Negative selection algorithm detector generation cuckoo search optimization

Inter-cluster Voltage Balancing Control of Modular Multilevel Cascaded Converter Under Unbalanced Grid Voltage

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Journal of Modern Power Systems and Clean Energy 2022年第2期10卷 515-523页

作者： Oghenewvogaga Oghorada Li Zhang ayodele Esan Dickson Egbune Julius Uwagboe the Department of Electrical&Information Engineering Landmark UniversityOmu-AranKwara StateNigeria University of Leeds LeedsUnited Kingdom

This paper presents a novel inter-cluster direct current(DC)capacitor voltage balancing control scheme for the single-star configured modular multilevel cascaded converter(MMCC)-based static synchronous compensator(STATCOM)under unbalanced grid *** negative-sequence component of grid voltage at the point of common connection(PCC)causes unbalanced active power flow in the phase limbs of *** leads to the imbalance of DC voltages of the sub-module capacitors across the MMCC phases,and consequently,the malfunction of *** proposed solution is to inject both negative-sequence current(NSC)and zero-sequence voltage(ZSV)into the phase limbs of MMCC.A quantification factor Qf is used to achieve the sharing of inter-cluster active pow-er between the NSC and ZSV injection *** determination of the quantification factor has been *** addition to maintaining the DC voltages of sub-module capacitor across the MMCC phases balanced,it also prevents the overcurrent and overvoltage of converter by injecting NSC and ZSV with the right *** control scheme is validated on a 3.54 kV 1.2 MVA power system using MMCC-based STATCOM with 3-level bridge cells as *** results show that the proposed scheme provides superior effectiveness in eliminating the voltage imbalance of DC capacitor in the phase limb while maintaining low voltage and current ratings.

关键词： Low-voltage ride through(LVRT) single-star bridge converter(SSBC) static synchronous compensator(STATCOM) modular multilevel cascaded converter(MMCC) quantification factor

Direct radiative forcing of urban aerosols over Pretoria(25.75°S, 28.28°E) using AERONET Sunphotometer data:First scientific results and environmental impact

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Journal of Environmental Sciences 2014年第12期26卷 2459-2474页

作者： ayodele Joseph Adesina Kanike Raghavendra Kumar Venkataraman Sivakumar Derek Griffith Discipline of Physics School of Chemistry and Physics College of Agriculture Engineering and Science Westville CampusUniversity of Kwa Zulu–Natal Durban 4000 South Africa Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration School of Atmospheric PhysicsNanjing University of Information Science and Technology Optronic Sensor Systems Council for Scientific and Industrial Research (CSIR)–DPSS Pretoria 0001 South Africa

The present study uses the data collected from Cimel Sunphotometer of Aerosol Robotic Network（AERONET） for the period from January to December, 2012 over an urban site,Pretoria（PTR; 25.75°S, 28.28°E, 1449 m above sea level）, South Africa. We found that monthly mean aerosol optical depth（AOD, τa） exhibits two maxima that occurred in summer（February） and winter（August） having values of 0.36 ± 0.19 and 0.25 ± 0.14,respectively, high-to-moderate values in spring and thereafter, decreases from autumn with a minima in early winter（June） 0.12 ± 0.07. The Angstrom exponents（α440–870） likewise,have its peak in summer（January） 1.70 ± 0.21 and lowest in early winter（June） 1.38 ± 0.26,while the columnar water vapor（CWV） followed AOD pattern with high values（summer） at the beginning of the year（February, 2.10 ± 0.37 cm） and low values（winter） in the middle of the year（July, 0.66 ± 0.21 cm）. The volume size distribution（VSD） in the fine-mode is higher in the summer and spring seasons, whereas in the coarse mode the VSD is higher in the winter and lower in the summer due to the hygroscopic growth of aerosol *** single scattering albedo（SSA） ranged from 0.85 to 0.96 at 440 nm over PTR for the entire study period. The averaged aerosol radiative forcing（ARF） computed using SBDART model at the top of the atmosphere（TOA） was- 8.78 ± 3.1 W/m2, while at the surface it was- 25.69 ± 8.1 W/m2 leading to an atmospheric forcing of ＋ 16.91 ± 6.8 W/m2, indicating significant heating of the atmosphere with a mean of 0.47 K/day.

关键词： Pretoria AERONET Aerosol optical depth Single scattering albedo Radiative forcing

Optimal placement of wind turbines within a wind farm considering multi-directional wind speed using two-stage genetic algorithm

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Frontiers in Energy 2021年第1期15卷 240-255页

作者： A.S.O.OGUNJUYIGBE T.R.ayodele O.D.BAMGBOJE Power Energy Machines and Drives(PEMD)Research Group Department of Electrical and Electronic EngineeringUniversity of IbadanNigeria

Most wind turbines within wind farms are set up to face a pre-determined wind ***,wind directions are intermittent in nature,leading to less electricity production *** paper proposes an algorithm to solve the wind farm layout optimization problem considering multi-angular(MA)wind direction with the aim of maximizing the total power generated on wind farms and minimizing the cost of installation.A twostage genetic algorithm(GA)equipped with complementary sampling and uniform crossover is used to evolve a MA layout that will yield optimal output regardless of the wind *** the first stage,the optimal wind turbine layouts for 8 different major wind directions were determined while the second stage allows each of the previously determined layouts to compete and inter-breed so as to evolve an optimal MA wind farm *** proposed MA wind farm layout is thereafter compared to other layouts whose turbines have focused site specific wind turbine *** results reveal that the proposed wind farm layout improves wind power production capacity with minimum cost of installation compared to the layouts with site specific wind turbine *** paper will find application at the planning stage of wind farm.

关键词： optimal placement wind turbines wind direction genetic algorithm wake effect

Type 1 diabetes in a Nigerian family-occurrence in three out of four siblings: A case report

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World Journal of Diabetes 2019年第10期10卷 511-516页

作者： Michael Adeyemi Olamoyegun Oluwabukola ayodele Ala Department of Internal Medicine EndocrinologyDiabetes&Metabolism UnitCollege of Health SciencesLadoke Akintola University of Technology(LAUTECH)/LAUTECH Teaching HospitalOgbomoso 240222Oyo StateNigeria Department of Internal Medicine EndocrinologyDiabetes&Metabolism UnitBOWEN University Teaching Hospitaland College of Health SciencesBOWEN UniversityIwo 232101Osun StateNigeria

BACKGROUND Most occurrences of type 1 diabetes cases in any population are sporadic rather than ***,type 1 diabetes among siblings is a rare *** more rare is for three or more siblings to develop type 1 *** this report,we describe a case of a Nigerian family in which type 1 diabetes occurred in three siblings among four children with neither parent having *** three siblings are positive for glutamic acid decarboxylase and anti-islet cell *** SUMMARY There were four siblings(three males and one female)born to a couple without a diagnosis of *** eldest child(male)was diagnosed with diabetes at the age of 15,the second child(female)was diagnosed at the age of 11 and the fourth child(male)was diagnosed at the age of *** the siblings presented with similar osmotic symptoms and were diagnosed of diabetic *** of them had markedly reduced serum C-peptide levels with high levels of glutamic acid decarboxylase and insulinoma-associated protein-2 *** could not perform genetic analysis of HLA-DR,DQ and CTLA4 in the siblings as well as the parents;hence haplotypes could not be *** parents of the probands have no prior history of diabetes,and their blood glucose and glycated hemoglobin levels were within normal *** third child(male)has no history suggestive of diabetes,and his blood glucose and glycated hemoglobin have remained within normal *** Although the occurrence of type 1 diabetes in proband siblings is uncommon,screening for diabetes among siblings especially with islet autoantibodies should be encouraged.

关键词： Type 1 diabetes Siblings Case report Nigerian Family