Nigerian Journal of Technology最新文献_第10页

An assessment of the implications of gravity reduction methods on local geoid modelling over Ado Ekiti Ado Ekiti上重力折减方法对局部大地水准面建模影响的评估

Nigerian Journal of Technology Pub Date : 2023-03-14 DOI: 10.4314/njt.v41i6.6

R. Ehigiator - Irughe, O. A. Abiodun, J. Odumosu

引用次数: 0

Effect of sugarcane bagasse ash and plantain leaf ash on geotechnical properties of clay soil from Efab Estate, Awka, Anambra State 甘蔗渣灰和车前草叶灰对阿南布拉州Efab Estate粘土岩土性能的影响

Nigerian Journal of Technology Pub Date : 2023-03-14 DOI: 10.4314/njt.v41i6.4

N. Ezema, B. Adinna, C. Anayo

{"title":"Effect of sugarcane bagasse ash and plantain leaf ash on geotechnical properties of clay soil from Efab Estate, Awka, Anambra State","authors":"N. Ezema, B. Adinna, C. Anayo","doi":"10.4314/njt.v41i6.4","DOIUrl":"https://doi.org/10.4314/njt.v41i6.4","url":null,"abstract":"This study investigated the feasibility of using agricultural wastes: sugarcane bagasse ash and plantain leaves ash for clay soil stabilization. The sample was mixed using five trial mixes: 0%BA:10%PLA, 3%BA:7%PLA, 5%BA:5%PLA, 7%BA :3%PLA, 10%BA:0%PLA and a control mix. Characterization of these ashes was done using the X-ray fluorescence testing method. Specific gravity, sieve analysis, Atterberg limits, compaction and California bearing ratio tests were also assessed. The clay soil was described as A-7-6 (AASHTO). After X-ray characterization, BA and PLA possessed 61.97% and 28.27% pozzolanic content respectively. From the liquid limit results, on addition of 3%BA :7%PLA, a significant decrease in values of 47.0%, 32.0% and 15.0% to 36.0%, 26.0% and 10.0% for LL, PL and PI was documented. Also, the addition of plantain leaves alone significantly decreases atterberg limit values. For compaction, 3%BA and 7%PLA recorded the least MDD value of 18.44kN/ m3 and peak value of 19.42kN/m3 at 0%BA: 10%PLA. 10%PLA and 10%BA recorded CBR soaked values of 57.8% and 62.1% whilst 7%BA:3%PLA yielded best results of 51.3% CBR soaked values. These findings reveal significant improvements in strength and index properties of the clay soil. In conclusion, bagasse ash and plantain leaves ash produce an eco-friendly stabilizer that can be utilized as subbase material in the stabilization of clay soils","PeriodicalId":33360,"journal":{"name":"Nigerian Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41890624","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

Matlab-based simulations of a three-phase induction motor for dynamic studies 基于matlab的三相感应电机仿真动态研究

Nigerian Journal of Technology Pub Date : 2023-03-14 DOI: 10.4314/njt.v41i6.10

N. Yaabari, O. Okoro, E. Akpama

{"title":"Matlab-based simulations of a three-phase induction motor for dynamic studies","authors":"N. Yaabari, O. Okoro, E. Akpama","doi":"10.4314/njt.v41i6.10","DOIUrl":"https://doi.org/10.4314/njt.v41i6.10","url":null,"abstract":"The aim of this paper is to develop a generalized MATLAB program to study the dynamic behavior of a three-phase induction motor. The d-q axis transformation theory is applied in rotor reference frame to study the motor dynamics. A general-purpose MATLAB program is developed and used for the dynamic simulation of a 5HP, 460V, 60Hz, 4-poles induction motor. The developed program is used to study the effect of variation of Stator Resistance (Rs), Moment of Inertia (J), and Load Torque (TL) at t=0.7sec during transient state. The results obtained show that, the torque-speed characteristic curve and mechanical rotor speed-time characteristics of induction motor depend upon the rotor resistance and the moment of inertia. Also, during the simulation of the motor under loaded torque at t=0.7sec, the results showed an increase in the initial starting torque and it reduces from 2000Nm – 0Nm as the operating time progressed. A sudden residual increase occurred in the torque from 0-1000Nm at the loaded time t=0.7sec, and the mechanical rotor speed increased at starting time from 0-1800rpm with respect to operating time and suddenly experienced a drop from 1800rpm to about 1700rpm at the loaded time of t=0.7 sec. The developed program is particularly useful for machine designers in the manufacture of various types of induction machines.","PeriodicalId":33360,"journal":{"name":"Nigerian Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42478620","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

Burning characteristics of briquette produced from sawdust of Ficus exasperata and cassava peel using different binders 不同粘结剂对榕树木屑和木薯皮成型煤燃烧特性的影响

Nigerian Journal of Technology Pub Date : 2023-03-14 DOI: 10.4314/njt.v41i6.15

K. M. Ogunjobi, M. Chikwendu, A. T. Ogunfowodu, A. Adetogun

{"title":"Burning characteristics of briquette produced from sawdust of Ficus exasperata and cassava peel using different binders","authors":"K. M. Ogunjobi, M. Chikwendu, A. T. Ogunfowodu, A. Adetogun","doi":"10.4314/njt.v41i6.15","DOIUrl":"https://doi.org/10.4314/njt.v41i6.15","url":null,"abstract":"Energy used for domestic application is expensive and utilization of an alternative energy has become imperative. The study evaluated the combustion properties of briquettes produced from sawdust particles of Ficus exasperata and Cassava peel using different binders. Sawdust was mixed with the binders at a ratio (60 : 40) top bond, (40 : 60) starch and (60 : 40) cow dung, while the cassava peel mixed with the binders at a ratio (40:60) top bond, (60 : 40) starch and (40 : 60) cattle dung. This is followed by admixture of sawdust and cassava peel with the binders at ratio (25 : 25 : 50) top bond, (25 : 25 : 50) sawdust and (25 : 25 : 50) cattle dung, and substrate mixed with binders at ratio (20 : 20 : 20 : 20 : 20) respectively. Data analysis was carried out using a two-way analysis of variance. The proximate composition result reveals that the percentage ash content was significant at p<0.05. Results on binders revealed that heating value (HV) was highest at starch (32.48Mj/kg) and lowest in cattle dung (30.9Mj/kg) while result on substrate reveals highest HV at sawdust (32.79Mj/kg) and lowest in cassava peel (30.39) with significant higher % ash content (9.5). Therefore, this study reveals that briquette of admixture of sawdust and cassava peel bonded with starch had the best burning characteristics and could be maximized as alternative source to energy.","PeriodicalId":33360,"journal":{"name":"Nigerian Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43076675","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

Assessment of potable water accessibility in Ikole-Ekiti, Nigeria 尼日利亚Ikole Ekiti饮用水可及性评估

Nigerian Journal of Technology Pub Date : 2023-03-14 DOI: 10.4314/njt.v41i6.14

A. Oloye, O. Ilesanmi, B. Alabadan, O. Omofunmi, K. Oni, M. Ebong

{"title":"Assessment of potable water accessibility in Ikole-Ekiti, Nigeria","authors":"A. Oloye, O. Ilesanmi, B. Alabadan, O. Omofunmi, K. Oni, M. Ebong","doi":"10.4314/njt.v41i6.14","DOIUrl":"https://doi.org/10.4314/njt.v41i6.14","url":null,"abstract":"Water occurred naturally and it is used widely for drinking, cooking, washing, agricultural activities, population expansion, urbanization, generation of power, and industrialization. Availability and accessibility are used to estimate the percentage of the population using safe water sources. However, potable water is inaccessible and unavailable for use in most of the communities in Nigeria. Therefore, this study access safe potable water sources available for use in three towns in Ikole LGA of Ekiti State, Nigeria. A random sampling approach was adopted by selecting households and respondents for participation in the study. Questionnaires were administered to 40 respondents in each of the three communities chosen giving a total of 120 respondents for this study. Data collected were analyzed using descriptive statistics. The results showed that available water sources were streams, rivers, rain, wells, boreholes, and lakes. 41.67 % of the respondents have access to safe water sources and also use water filters. There is the urgent need for Nigeria to invest more in accessing safe water sources for its citizens to achieve the Sustainable Development Goals.","PeriodicalId":33360,"journal":{"name":"Nigerian Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41475279","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

An android based home automation system with Internet of Things 基于android的物联网家庭自动化系统

Nigerian Journal of Technology Pub Date : 2023-03-14 DOI: 10.4314/njt.v41i6.13

T. Adepoju, O. K. Orimogunje, A. A. Akanni, D. O. Oluwuyi

{"title":"An android based home automation system with Internet of Things","authors":"T. Adepoju, O. K. Orimogunje, A. A. Akanni, D. O. Oluwuyi","doi":"10.4314/njt.v41i6.13","DOIUrl":"https://doi.org/10.4314/njt.v41i6.13","url":null,"abstract":"Home automation is the introduction of technology within the environment to provide convenience, comfort, security and energy efficiency to its occupants. The management and control of our home appliances is germane to living and having a better quality of life, hence the need to design a system that automates the control of home appliances to ease the stress of having to manually control household appliances. An Android based home automation system with Internet of Things (IOT) was designed and implemented to control electrical appliances The hardware module consists of the power and control sections. The system draws power from the mains outlet and is converted to 5V by the AC-DC converter circuit. The software section comprises of the ESP8266 WiFi Microcontroller code, the Android application which controls the microcontroller wirelessly, the web server and WiFi connection. The designed home automation system was effective in remotely controlling electrical appliances. It also displays the weather information in the application in digital format. The system is portable and practicable due to its compact size. The system can be used to ensure efficient usage of electrical energy as well as maintain a good atmospheric condition.","PeriodicalId":33360,"journal":{"name":"Nigerian Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47545835","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

A mobility aware handover scheme for 4G LTE system 一种适用于4G LTE系统的移动感知切换方案

Nigerian Journal of Technology Pub Date : 2023-03-14 DOI: 10.4314/njt.v41i6.8

O. Ojesanmi, O. R. Vincent, M. A. Kassim, O. Osinuga

{"title":"A mobility aware handover scheme for 4G LTE system","authors":"O. Ojesanmi, O. R. Vincent, M. A. Kassim, O. Osinuga","doi":"10.4314/njt.v41i6.8","DOIUrl":"https://doi.org/10.4314/njt.v41i6.8","url":null,"abstract":"Reduction in cell size in an ultra-dense network faces the challenge of increase in frequency of handovers and signaling overhead (mobility management) as well as inter-cell interference. Such frequent handovers leads to increased packet loss and blocking rate if the handover latency is very high, which have adverse effect on connectivity and performance. However, most existing schemes have the common characteristics of increasing spectral and energy efficiency due to increase in the number of micro cell on a network, thus decreases the general network performance. In this study, an improved scheme was developed for fixed mobility management pattern (FMP). A comparison module was established and an identifier algorithm that uses the user equipment international mobile equipment identity (IMEI) as a decisive component of its cell selection camping process was designed. Network simulator (NS-3) was used to study the impact of macro cell and inter site distance (ISD) on user throughput and battery life usage using mobility pattern of 3km/h, with A3 event based measurement for ISD 50, 150, 300, 500, and 1000 respectively. The performance evaluation metrics used are; reference signal received power (RSRP), flow monitor and handover time. The FMP results were compared with micro cell performance in an ultra-dense network. The RSRP result from FMP was higher than that of micro cell at ISD 50 and 150 respectively (-71.36, -73.97 and 83.77, 85.13). The handover time for FMP was higher than that of micro cell except for ISD 50 which was 50s and 51s respectively. The flow monitor of FMP showed a packet loss ratio of 0.0001 compare to 0.21 of micro cell. The battery life usage shows that FMP used 5943±8.7mw compare to micro cell which used 1680.2±15.7 mw. These results showed that FMP is efficient in managing the frequency of handover and battery life consumption for better connectivity and performance.","PeriodicalId":33360,"journal":{"name":"Nigerian Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47659935","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

Reactive power model reference adaptive speed-sensorless system with direct torque control tuned with fuzzy neural networks for improved speed control in induction motor drives 基于模糊神经网络的无功模型参考自适应无速度传感器直接转矩控制系统用于改进异步电动机的速度控制

Nigerian Journal of Technology Pub Date : 2023-03-14 DOI: 10.4314/njt.v41i6.9

O. E. Ozoemena, E. Ashigwuike

{"title":"Reactive power model reference adaptive speed-sensorless system with direct torque control tuned with fuzzy neural networks for improved speed control in induction motor drives","authors":"O. E. Ozoemena, E. Ashigwuike","doi":"10.4314/njt.v41i6.9","DOIUrl":"https://doi.org/10.4314/njt.v41i6.9","url":null,"abstract":"This article investigates a reactive power based Model Reference Adaptive System (Q-MRAS) with Fuzzy Neural Network (FNN) facilitated Direct Torque Control for improved speed control of an Induction Motor Drive. A key component of the conventional DTC control scheme is the use of PID controllers and its derivatives. PID controllers were found to be a source of ripples. To mitigate its effect, in this work, a novel idea of replacing all the PI controls in the conventional speed control DTC models with FNN based controllers is investigated. The goal is to reduce complexity, reduce ripples in speed and boost low speed operation suitable for industrial needs. The proposed FNN controllers-based model is implemented using Matlab/Simulink. Comparisons are made between the results obtained from the proposed model and that from conventional models (Switching Table based DTC and SVM-DTC). Results showed that in the proposed FNN based DTC model, low speed operation (100 rpm) had 0.13 % speed ripple compared to 0.94 % in the conventional Switching Table based DTC and 0.23 % in the conventional SVM-DTC. This represents a reduction in speed ripple by 86.17 % in the proposed scheme compared to the Switching-Table DTC and by 43.48 % in the proposed scheme compared to the SVM-DTC scheme.","PeriodicalId":33360,"journal":{"name":"Nigerian Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43018694","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

Detection of Distributed Denial of Service (DDoS) attacks using convolutional neural networks 使用卷积神经网络检测分布式拒绝服务（DDoS）攻击

Nigerian Journal of Technology Pub Date : 2023-03-14 DOI: 10.4314/njt.v41i6.12

A. Akinwumi, A. Akingbesote, O. O. Ajayi, F. Aranuwa

引用次数: 0

Comparative evaluation of spectrum occupancy of the broadcasting bands in urban, sub-urban and rural environments 城市、次城市和农村环境中广播频带频谱占用率的比较评估

Nigerian Journal of Technology Pub Date : 2023-03-14 DOI: 10.4314/njt.v41i6.11

E. A. Ubom, U. Ukommi

{"title":"Comparative evaluation of spectrum occupancy of the broadcasting bands in urban, sub-urban and rural environments","authors":"E. A. Ubom, U. Ukommi","doi":"10.4314/njt.v41i6.11","DOIUrl":"https://doi.org/10.4314/njt.v41i6.11","url":null,"abstract":"Wireless services are at high demand all over the world, leading to increased bandwidth requirement and exhausted spectrum. In response, efforts are on-going to find ways to allow secondary access to spectrum without causing unacceptable interference issues to the Primary Users. In the fore-front of these efforts is the attempt to allow for secondary access on the TV spectrum, hence this analysis on spectrum usage measured outdoors in three locations namely Calabar in Cross River State representing an urban environment, Eket and Asong in Akwa Ibom State representing semi-urban and rural communities in Nigeria respectively. The UHF band percentage utilizations for the three locations were 98%, 76% and 33% with available cumulative bandwidths of 8MHz, 96MHz, and 264MHz respectively. Further validation of urban spectrum condition was done at Uyo in Akwa Ibom State. Findings showed that the spectrums are relatively busy in the urban and semi-urban areas whereas the economically challenging rural areas have free spectrum that can be deployed to enhance cellular broadband services at affordable rates to uplift the living standard of the dwellers.","PeriodicalId":33360,"journal":{"name":"Nigerian Journal of Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44502995","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