Nigerian Journal of Technological Development最新文献_第10页

Impact of shunt capacitor penetration level in radial distribution system considering techno-economic benefits 考虑技术经济效益的径向配电系统并联电容器渗透水平的影响

Nigerian Journal of Technological Development Pub Date : 2022-08-01 DOI: 10.4314/njtd.v19i2.1

S. Salimon, G. Adepoju, I. Adebayo, S. O. Ayanlade

{"title":"Impact of shunt capacitor penetration level in radial distribution system considering techno-economic benefits","authors":"S. Salimon, G. Adepoju, I. Adebayo, S. O. Ayanlade","doi":"10.4314/njtd.v19i2.1","DOIUrl":"https://doi.org/10.4314/njtd.v19i2.1","url":null,"abstract":"Shunt Capacitor (SC) integration in radial distribution networks is a method utilized to minimize power losses and huge voltage drops. In other to obtain these maximum benefits, they should be optimally allocated. To this effect, researchers have used various optimization methods for solving SC allocation problems but most have not considered how the penetration level of SC into the radial distribution system affects these benefits. The goal of the paper, therefore, is to determine the most sensitive buses to reactive compensation and investigate the effect of the penetration level of SC on the techno-economic benefits. Load flow was performed for the base case to determine the steady-state performance of the system and the most sensitive buses were selected using New Voltage Stability Index (NVSI) technique. The size of the SC was increased in step of these buses, in turn, to determine SC penetration level impact on the techno-economic benefits. The approach was implemented on IEEE 33-bus and practical Nigerian radial distribution networks. The results showed that appropriate penetration of SC on networks leads to reduction of power losses, voltage profile improvement as well cost reduction resulting in high net savings.","PeriodicalId":31273,"journal":{"name":"Nigerian Journal of Technological Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48008155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Object detection for robot coordination in robotics soccer 机器人足球中机器人协调的目标检测

Nigerian Journal of Technological Development Pub Date : 2022-08-01 DOI: 10.4314/njtd.v19i2.5

C. Yinka-banjo, O. Ugot, E. Ehiorobo

{"title":"Object detection for robot coordination in robotics soccer","authors":"C. Yinka-banjo, O. Ugot, E. Ehiorobo","doi":"10.4314/njtd.v19i2.5","DOIUrl":"https://doi.org/10.4314/njtd.v19i2.5","url":null,"abstract":"In June 2018, iCog Labs held its second annual robosoccer competition which featured groups of humanoid robots playing soccer against each other. The authors were members of a team called upon to represent Nigeria with the University of Lagos at the competition which took place in Ethiopia. The work here presents a review of the approach taken to address the problem of automating robot coordination in real-world soccer applications. The design methodology relies on the Robot Operating System (ROS) as the platform upon which an asynchronous communication network between each robot and a central server is built. On the network, each robot is a node that consists of sub nodes for object detection and motion control. For object detection the work makes use of the you only look once (YOLO)v2 deep learning algorithm, and a simple decision-making algorithm for controlling vcv the robot based on the objects detected is devised. To quantify the object detection results, the common objects in context (COCO) evaluation metric is used. The results indicate an average recall and precision of 84% across different IOU. For qualitative results on the robot coordination in the ball’s direction, a reference to the open-source implementation of the work has been provided.","PeriodicalId":31273,"journal":{"name":"Nigerian Journal of Technological Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43172341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Analysis of decomposing wood wastes in the Lagos Lagoon using terminal-restriction fragment length polymorphism and illumina sequencing platform 利用末端限制性片段长度多态性和illumina测序平台分析Lagos泻湖木材废弃物

Nigerian Journal of Technological Development Pub Date : 2022-08-01 DOI: 10.4314/njtd.v19i2.3

O. M. Buraimoh, G. Adewumi, N. Akinyemi, O. Amund, M. O. Ilori, F. C. Michel Jr.

{"title":"Analysis of decomposing wood wastes in the Lagos Lagoon using terminal-restriction fragment length polymorphism and illumina sequencing platform","authors":"O. M. Buraimoh, G. Adewumi, N. Akinyemi, O. Amund, M. O. Ilori, F. C. Michel Jr.","doi":"10.4314/njtd.v19i2.3","DOIUrl":"https://doi.org/10.4314/njtd.v19i2.3","url":null,"abstract":"Indiscriminate disposal of wood shavings and sawdust into the Lagos lagoon usually constitute environmental hazard and varying degree of threats to marine biotic communities. In this study we applied terminal-restriction fragment length polymorphism (T-RFLP) and illumina sequencing of 16S ribosomal RNA gene, to describe the microbial ecology of decomposing wood wastes in the Lagos lagoon, Nigeria. The terminal restriction fragments (TRFs) generated corresponds to over 100 bacterial genera and numerous uncultured bacterial clones. Phylogenetic analysis of the TRFs of 16S rRNA gene sequences and cultured bacterial sequences established genetic relatedness and divergent relationships. T-RFLP in combination with illumina sequencing platform identified bacterial species (Acinetobacter sp., Clostridium sp., Planctomyces sp., Escherichia coli, Pantoea agglomerans, Dyella japonica, Ochrobactrum sp., Prevotella sp., Runella slithyformis, Enterobacter aerogenes, Gordonia amicalis, Klebsiella sp., Thalassospira sp. and Serratia sp.) not previously accounted for in culture-dependent analysis. Bacterial strains such as Ruminococcus flavefaciens, Fibrobacter succinogenes, Simiduia agarivorans, Microbulbifer sp. and Cellulomonas fimi further identified in illumina sequences were found to be involved in the biodegradation of lignin and lignin derivatives. Hence, understanding of the diverse autochthonous microbiota of decomposing wood wastes in the Lagos lagoon is essential in the development of effective biotechnology programme, to tackling the menace of sawdust pollution.","PeriodicalId":31273,"journal":{"name":"Nigerian Journal of Technological Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46738530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Capacitively-excited single-phase asynchronous generator for autonomous applications 自主应用的电容激励单相异步发电机

Nigerian Journal of Technological Development Pub Date : 2022-08-01 DOI: 10.4314/njtd.v19i2.4

K. Sanusi, L. Olatomiwa, A. Mohammed, K. A. Sodiq

引用次数: 0

Extraction and physicochemical characterization of cashew nut-shell liquid in metal forming 金属成型腰果果壳液的提取及理化性质研究

Nigerian Journal of Technological Development Pub Date : 2022-08-01 DOI: 10.4314/njtd.v19i2.2

O. Sekunowo, G. U. Uduh

{"title":"Extraction and physicochemical characterization of cashew nut-shell liquid in metal forming","authors":"O. Sekunowo, G. U. Uduh","doi":"10.4314/njtd.v19i2.2","DOIUrl":"https://doi.org/10.4314/njtd.v19i2.2","url":null,"abstract":"ABSTRACT: Effective lubrication during metal working is critical to mitigating undesirable tool wear and poor surface finish of formed components. This paper investigated the physicochemical characteristics of cashew nut-shell-liquid (CNSL) with a view of determining its suitability for the development of an eco-friendly lubricant used in metal forming. The cashew nut shell oil (CNSO) was extracted by soxhlet method and characterised to determine its physicochemical properties including density, free fatty acid (FFA), and viscosity. In addition, the saponification value, iodine value, pH, flash point and friction coefficient were determined using relevant analytical tools. The results showed that CNSL yield from soxhlet solvent extraction is 45.6%, which is adjudged to be relatively substantial with regard to other extraction processes. Furthermore, the CNSL exhibited critical lubrication characteristics in terms of density (0.94 g/cm3), moisture content (3.96%), acid value (11.32 mg.KOH/g), FFA (3.7%), ester value (127.92 mg.KOH/g), saponification value (139.24 mg.KOH/g), pH value (4.61), iodine value (40.21 gI2/100 g), viscosity at 100 oC (14.12 Pa.s), friction coefficient (0.001) and flash point of 286.63 oC. Given these outcomes in comparison with commercial Chevron soluble oil, it is concluded that CNSL is suitable for use as a viable metal forming lubrication fluid.","PeriodicalId":31273,"journal":{"name":"Nigerian Journal of Technological Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48465698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Estimation of losses and efficiency of double-stator switched flux permanent magnet machines 双定子开关磁通永磁电机的损耗和效率估算

Nigerian Journal of Technological Development Pub Date : 2022-08-01 DOI: 10.4314/njtd.v19i2.7

C. Awah, O. Okoro, A. Onah, G. Diyoke

{"title":"Estimation of losses and efficiency of double-stator switched flux permanent magnet machines","authors":"C. Awah, O. Okoro, A. Onah, G. Diyoke","doi":"10.4314/njtd.v19i2.7","DOIUrl":"https://doi.org/10.4314/njtd.v19i2.7","url":null,"abstract":"Losses such as rotor iron and stator iron losses, magnet eddy current loss, as well as efficiency of a double stator permanent magnet machine having varying rotor pole numbers is estimated and presented in this study. This current investigation would be vital for electrical machine designers in quantifying the amount of losses in the various sections of a given double stator electric machine and as well provide better insight on resulting output efficiency of the machine. Time-stepping finite element analysis (TS-FEA) procedure is adopted in the calculations using ANSYS-MAXWELL simulation software. The compared machines having the same stator teeth/pole number (Ps) and different rotor pole (Pr) numbers are designated as: 6Ps/10Pr, 6Ps/11Pr, 6Ps/13Pr and 6Ps/14Pr. The predicted total loss values at rated current and operating base speed is 13.02 Watts, 13.13 Watts, 13.539 Watts, 13.537 Watts, from the 6Ps/10Pr, 6Ps/11Pr, 6Ps/13Pr and 6Ps/14Pr machine types, respectively. The corresponding efficiency of the machine types at rated working conditions is: 81.76%, 88.17%, 86.95% and 78.61%, respectively. The results show that magnitude of losses in a given machine would largely depend upon factors such as number of rotor poles and hence, the machine’s operating speed, electric loading and angular rotor position of the machine, etc. It is also found that the number of loss waveform cycles (Nc) in an electric revolution of the investigated machine would depend upon its stator and rotor arrangements. The most performing compared machine types are the ones that have 11- and 13-rotor pole numbers, while the least amount of efficiency is obtained from the machine type that has 14-rotor pole number. Above all, the 6Ps/10Pr and 6Ps/14Pr are characterized with high amount of pulsations or ripples and this is detrimental to the overall performance of the machines.","PeriodicalId":31273,"journal":{"name":"Nigerian Journal of Technological Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44285316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical investigation of thermal performance of a combined heat sink with various microchannel shapes 不同微通道形状组合散热器热性能的数值研究

Nigerian Journal of Technological Development Pub Date : 2022-08-01 DOI: 10.4314/njtd.v19i2.9

A. Lawal, O. Adewumi, O. T. Olakoyejo

引用次数: 2

Optimization approaches to generation dispatch problems: Review of Nigerian power system 发电调度问题的优化方法：尼日利亚电力系统综述

Nigerian Journal of Technological Development Pub Date : 2022-08-01 DOI: 10.4314/njtd.v19i2.

M. A. Tijani, G. Adepoju, M. Okelola

引用次数: 0

Identification of pharming in communication networks using ensemble learning 使用集成学习识别通信网络中的群集

Nigerian Journal of Technological Development Pub Date : 2022-08-01 DOI: 10.4314/njtd.v19i2.10

N. Azeez, S. Oladele, O. Ologe

{"title":"Identification of pharming in communication networks using ensemble learning","authors":"N. Azeez, S. Oladele, O. Ologe","doi":"10.4314/njtd.v19i2.10","DOIUrl":"https://doi.org/10.4314/njtd.v19i2.10","url":null,"abstract":"Pharming scams are carried out by exploiting the DNS as the main weapon while phishing attacks employ spoofed websites that appear to be legitimate to internet users. Phishing makes use of baits such as fake links but pharming leverages and negotiates on the DNS server to move and redirect internet users to a fake and simulated website.Having seen several challenges through pharming resulting into vulnerable websites, personal emails and accounts on social media, the usage and reliability on internet calls for caution. Against this backdrop, this work aims at enhancing pharming detection strategies by adopting machine learning classification algorithms. To further obtain the best classification results, an ensemble learning approach was adopted. The algorithms used include K-Nearest Neighbors (KNN), Decision Tree, Random Forest, Gaussian Naive Bayes, Logistic Regression, Support Vector Machine, Adaptive Boosting, Gradient Boosting, and Extra Trees Classifier. During the testing process, the classifiers were tested against four popular metrics: accuracy, recall, precision, F1 score, and Log loss. The results demonstrate the performance of all algorithms used, as well as their relationships. The ensemble model that included Logistic Regression, K-Nearest Neighbors, Decision Tree, Support Vector Machine, Gradient Boosting Classifier, AdaBoost Classifier, Extra Trees Classifier, and Random Forest produced the best results after evaluating them on the two datasets. Random Forest Classifiers showed a better performance of the classifiers, with mean accuracies of 0.932 and 0.939, respectively for each of the datasets when compared to 0.476 and 0.519 obtained for Naive Bayes.","PeriodicalId":31273,"journal":{"name":"Nigerian Journal of Technological Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44555026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Production of natural gas and liquefied petroleum gas from flare gas using methanol based process 用甲醇法从火炬气生产天然气和液化石油气

Nigerian Journal of Technological Development Pub Date : 2022-06-06 DOI: 10.4314/njtd.v19i1.7

P. U. Ndunagu, O. Joel, O. Akuma, E. E. Alaike

{"title":"Production of natural gas and liquefied petroleum gas from flare gas using methanol based process","authors":"P. U. Ndunagu, O. Joel, O. Akuma, E. E. Alaike","doi":"10.4314/njtd.v19i1.7","DOIUrl":"https://doi.org/10.4314/njtd.v19i1.7","url":null,"abstract":"Flare gas utilization has been a topic of discussion among stakeholders of the Nigerian Petroleum Industry and one of the simplest technical and commercial strategies is to send these gases to an existing gas pipeline with spare capacity. Peculiarities of flare gas can pose different challenges but the feasibility of the project depends on exogenous factors such as proximity to gas pipeline and availability of markets. In this work, an energy integrated methanol-based gas processing method for treatment and recovery of Liquefied Petroleum Gas (LPG) is presented using a high flaring intensity Nigerian Marginal oilfield close to an existing gas pipeline. A capacity of 60 MMscfd was determined using the flaring profile of the oilfield and a propane refrigeration system was selected as the cold process. ASPEN HYSYS V9 Cubic Plus Association (CPA) equation of state was used to optimally predict methanol (used as a hydrate inhibitor) partitioning in the methanol-hydrocarbon system. This process produced 57.15 MMscfd of natural gas, 163.7 tonne/day of LPG, and 33.19 tonne/day of stabilized condensate in line with Nigerian gas transport code specifications. The equipment count in comparison to other gas processing schemes, operational flexibility, and ease of scalability indicates that it is an economic technology that will be well suited for solving the gas flare scenario in the Niger Delta region by converting these wasted gas into more useful products.","PeriodicalId":31273,"journal":{"name":"Nigerian Journal of Technological Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43246193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0