Nigerian Journal of Technology最新文献_第4页

Sliding mode control for gasifier reactor temperature control 气化炉反应器温度控制的滑动模式控制

Nigerian Journal of Technology Pub Date : 2024-02-14 DOI: 10.4314/njt.v42i4.9

V.O. Ajah, E.T. Eke, K.E. Okoye, E.C. Ejiogu

{"title":"Sliding mode control for gasifier reactor temperature control","authors":"V.O. Ajah, E.T. Eke, K.E. Okoye, E.C. Ejiogu","doi":"10.4314/njt.v42i4.9","DOIUrl":"https://doi.org/10.4314/njt.v42i4.9","url":null,"abstract":"This paper presents a sliding mode control (SMC) design for gasifier reactor temperature control. Temperature control is a critical aspect of biomass gasification for quality syngas production. However, accurate modeling and effective control method are the major challenges of gasifier reactor temperature control. The gasification system processes are not yet well understood to model from the first principle due to the complex and nonlinear nature of the process. Also, conventional control methods such as proportional, integral, and derivative control have not been effective in controlling gasification systems. Hence, this work has used experimental data from a 500 kVA updraft gasifier reactor to develop a data-driven mathematical model. The system identification result predicts 86.36% goodness of fit on the model data and 88.26% on the validation data. Discrete time sliding mode control has been designed from the model and implemented in Simulink to investigate the performance of the control method on the gasifier. The result of the system time response shows that the controller effectively drives the temperature monotonically from 25°C to 700 °C in finite time (11.37 minutes). It also establishes a quasi-sliding motion with an ultimate band of ±1℃ for the remainder of the simulation time. Hence, the control technique guarantees optimal temperature control for any feedstock type which will result in higher conversion efficiency, more syngas yield, and improve syngas quality and durability of the gasifier reactor among others. ","PeriodicalId":33360,"journal":{"name":"Nigerian Journal of Technology","volume":"32 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139777610","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

Sliding mode control for gasifier reactor temperature control 气化炉反应器温度控制的滑动模式控制

Nigerian Journal of Technology Pub Date : 2024-02-14 DOI: 10.4314/njt.v42i4.9

V.O. Ajah, E.T. Eke, K.E. Okoye, E.C. Ejiogu

{"title":"Sliding mode control for gasifier reactor temperature control","authors":"V.O. Ajah, E.T. Eke, K.E. Okoye, E.C. Ejiogu","doi":"10.4314/njt.v42i4.9","DOIUrl":"https://doi.org/10.4314/njt.v42i4.9","url":null,"abstract":"This paper presents a sliding mode control (SMC) design for gasifier reactor temperature control. Temperature control is a critical aspect of biomass gasification for quality syngas production. However, accurate modeling and effective control method are the major challenges of gasifier reactor temperature control. The gasification system processes are not yet well understood to model from the first principle due to the complex and nonlinear nature of the process. Also, conventional control methods such as proportional, integral, and derivative control have not been effective in controlling gasification systems. Hence, this work has used experimental data from a 500 kVA updraft gasifier reactor to develop a data-driven mathematical model. The system identification result predicts 86.36% goodness of fit on the model data and 88.26% on the validation data. Discrete time sliding mode control has been designed from the model and implemented in Simulink to investigate the performance of the control method on the gasifier. The result of the system time response shows that the controller effectively drives the temperature monotonically from 25°C to 700 °C in finite time (11.37 minutes). It also establishes a quasi-sliding motion with an ultimate band of ±1℃ for the remainder of the simulation time. Hence, the control technique guarantees optimal temperature control for any feedstock type which will result in higher conversion efficiency, more syngas yield, and improve syngas quality and durability of the gasifier reactor among others. ","PeriodicalId":33360,"journal":{"name":"Nigerian Journal of Technology","volume":"12 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139837146","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

Development of passenger’s waiting time model at Bus Public Transit Terminal 开发公交总站乘客候车时间模型

Nigerian Journal of Technology Pub Date : 2024-02-14 DOI: 10.4314/njt.v42i4.3

M.N. Ibrahim, J.K. Ede

{"title":"Development of passenger’s waiting time model at Bus Public Transit Terminal","authors":"M.N. Ibrahim, J.K. Ede","doi":"10.4314/njt.v42i4.3","DOIUrl":"https://doi.org/10.4314/njt.v42i4.3","url":null,"abstract":"Passenger’s waiting time at terminal is a key constituent of travel time, as long waiting time increases the overall journey time. In Nigeria, urban-rural bus transit system is associated with long waiting time. This study evaluates bus transit users’ waiting times at terminal with perceived and actual waiting times (PWT and AWT) along with associated bus service frequency (BSF). Bus public transit operating from Enugu city (as origin) to 6 local government areas (Awgu, Isi-Uzo, Nkanu west, Nsukka, Oji River and Udenu) of the state as destinations was studied. Data were collected on AWT and PWT at Old Park, Enugu for 30 days from 8 am to 6 pm (5 days per route). Data on AWT and PWT were collected based on passenger’s observation and oral interview, respectively. The study discovered that transit users incurred long waiting times, with 80 – 90% of the users incurring AWT of 21 minutes to 1 hour and more, indicating a poor service quality. Also, 80 – 90% of the users overestimated their PWT by 25 – 60%. At 95% confidence level, PWT is significantly longer than AWT (P < 0.05) for all the routes. A passenger’s perceived waiting time model was developed for predicting PWT based on AWT. The model developed showed that PWT is strongly correlated with AWT, with an R2 = 0.9591 and F-significance < 0.05. This suggests that that AWT accounts for 96% variability in PWT. Consequently, the model developed exhibits a reasonable accuracy, hence, can be applied for prediction of passenger’s perceived waiting time. The mean BSF for Enugu – Nsukka and Enugu – Oji River routes were 30 and 21 buses per day, respectively. While, the other 4 routes recorded lower values of 7 – 9 buses per day, resulting in longer waiting times than the other 2 routes. The implication of long passengers’ waiting time suggests the need for shifting from unscheduled to scheduled operation and improved BSF by shortening bus headways to minimize waiting time. ","PeriodicalId":33360,"journal":{"name":"Nigerian Journal of Technology","volume":"42 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139837544","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 innovative simulation algorithm for optimising the cost of communal water supply systems using EPANET 利用 EPANET 优化公共供水系统成本的创新模拟算法

Nigerian Journal of Technology Pub Date : 2024-02-14 DOI: 10.4314/njt.v42i4.4

T.A. Fashanu, C. Ndunaga, M. A. Ogundero, O. Oluwatusin

{"title":"An innovative simulation algorithm for optimising the cost of communal water supply systems using EPANET","authors":"T.A. Fashanu, C. Ndunaga, M. A. Ogundero, O. Oluwatusin","doi":"10.4314/njt.v42i4.4","DOIUrl":"https://doi.org/10.4314/njt.v42i4.4","url":null,"abstract":"In this work, the EPANET software is used to parametrize the design, simulate and optimise the overall cost of building and running a reliable, sustainable and efficient communal Water Supply System. Considering a model community of forty houses with an average of six occupants per home, the developed optimization algorithm using the simulated annealing heuristics approach minimizes the total cost of continuous water distribution to the community through a system of pipe network in a way that satisfies the critical hydraulic rules and constraints for efficient water distribution. Thus, the controlled variables of the simulated system include volumetric flow, velocity and head loss. To realize the desired goal, the prototyped communal water distribution system was first simulated by water free fall i.e., only gravity feed under a peak demand flow condition. This facilitated the identification and localization of head-loss zones. Subsequently, virtual pump stations of various capacities were optimally introduced as boosters at identified nodal points to overcome critical head losses. The response of the system to varying capacities of the booster pumps was then used to analyse and determine the optimum capacity of the pump. Simulation outcome showed that the optimum least cost design for a sixtyyear system’s life cycle is achieved by using a combination of gravity and 5 hp (3.73 kW) pump with optimum pipe diameter ranging from 60 - 150mm. ","PeriodicalId":33360,"journal":{"name":"Nigerian Journal of Technology","volume":"2 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139777855","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

Box-Behnken optimization of pin-on-disc wear test process parameters 盒式贝肯（Box-Behnken）优化针盘磨损测试工艺参数

Nigerian Journal of Technology Pub Date : 2024-02-14 DOI: 10.4314/njt.v42i4.6

B. Aliemeke, H. A. Okwudibe, A. I. Omoakhalen, P. Major

引用次数: 0

Box-Behnken optimization of pin-on-disc wear test process parameters 盒式贝肯（Box-Behnken）优化针盘磨损测试工艺参数

Nigerian Journal of Technology Pub Date : 2024-02-14 DOI: 10.4314/njt.v42i4.6

B. Aliemeke, H. A. Okwudibe, A. I. Omoakhalen, P. Major

引用次数: 0

An innovative simulation algorithm for optimising the cost of communal water supply systems using EPANET 利用 EPANET 优化公共供水系统成本的创新模拟算法

Nigerian Journal of Technology Pub Date : 2024-02-14 DOI: 10.4314/njt.v42i4.4

T.A. Fashanu, C. Ndunaga, M. A. Ogundero, O. Oluwatusin

{"title":"An innovative simulation algorithm for optimising the cost of communal water supply systems using EPANET","authors":"T.A. Fashanu, C. Ndunaga, M. A. Ogundero, O. Oluwatusin","doi":"10.4314/njt.v42i4.4","DOIUrl":"https://doi.org/10.4314/njt.v42i4.4","url":null,"abstract":"In this work, the EPANET software is used to parametrize the design, simulate and optimise the overall cost of building and running a reliable, sustainable and efficient communal Water Supply System. Considering a model community of forty houses with an average of six occupants per home, the developed optimization algorithm using the simulated annealing heuristics approach minimizes the total cost of continuous water distribution to the community through a system of pipe network in a way that satisfies the critical hydraulic rules and constraints for efficient water distribution. Thus, the controlled variables of the simulated system include volumetric flow, velocity and head loss. To realize the desired goal, the prototyped communal water distribution system was first simulated by water free fall i.e., only gravity feed under a peak demand flow condition. This facilitated the identification and localization of head-loss zones. Subsequently, virtual pump stations of various capacities were optimally introduced as boosters at identified nodal points to overcome critical head losses. The response of the system to varying capacities of the booster pumps was then used to analyse and determine the optimum capacity of the pump. Simulation outcome showed that the optimum least cost design for a sixtyyear system’s life cycle is achieved by using a combination of gravity and 5 hp (3.73 kW) pump with optimum pipe diameter ranging from 60 - 150mm. ","PeriodicalId":33360,"journal":{"name":"Nigerian Journal of Technology","volume":"71 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139837617","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 exploratory investigation into the status of water, sanitation and hygiene (wash) of schools in Enugu State, Nigeria 对尼日利亚埃努古州学校的水、环境卫生和个人卫生状况进行探索性调查

Nigerian Journal of Technology Pub Date : 2023-11-03 DOI: 10.4314/njt.v42i3.15

C.C. Nnaji

{"title":"An exploratory investigation into the status of water, sanitation and hygiene (wash) of schools in Enugu State, Nigeria","authors":"C.C. Nnaji","doi":"10.4314/njt.v42i3.15","DOIUrl":"https://doi.org/10.4314/njt.v42i3.15","url":null,"abstract":"The status of water, sanitation and hygiene (WASH) facilities was investigated in sixty schools in seven local government areas of Enugu State, Nigeria. A total of sixty schools comprising of twenty-four (24) private schools, twenty (20) government schools and Sixteen (16) mission schools were investigated in this study. Using questionnaire and on-the-spot assessment, WASH facilities in the selected schools were subjected to in-depth scrutiny. The highest number of schools that do not have a water source within the school premises are government schools (10), followed by private schools (7) and then mission schools (2). About seventy-one percent (71%) of the schools investigated rely on self-help water supply sources such as water vendors, rainwater harvesting and private boreholes. Fifty-seven (57) or 95% of the sixty (60) schools of all the schools have toilet facilities ranging from improved pit latrine (10%), flush toilet (31.7%) and pour flush toilet (53.3%). With respect to toilet cleaning, 33%, 17% and 50% of private, government and mission school clean their toilets every day. Fifty-five percent (55%) of all schools always provide handwashing facilities while 13.3% never provide handwashing facilities. Based on school category, the distribution of schools that provide handwashing facilities are as follows: private schools – 54.2%, government schools – 40% and mission schools – 75%. There was a significant correlation (r = 0.85) between availability of toilet facilities and provision of handwashing facilities. There was also a significant correlation (r = 0.555) between the provision of handwashing facilities and the provision of soap.","PeriodicalId":33360,"journal":{"name":"Nigerian Journal of Technology","volume":"24 18","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135875274","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

Synthesis and characterization of alkyd resins from rubber seed/soybean oil blends 橡胶籽/大豆油共混醇酸树脂的合成与表征

Nigerian Journal of Technology Pub Date : 2023-11-03 DOI: 10.4314/njt.v42i3.4

I. Elabor, E.U. Ikhuoria, I.O. Bakare2, F.E. Okieimen, A.I. Aigbodion

{"title":"Synthesis and characterization of alkyd resins from rubber seed/soybean oil blends","authors":"I. Elabor, E.U. Ikhuoria, I.O. Bakare2, F.E. Okieimen, A.I. Aigbodion","doi":"10.4314/njt.v42i3.4","DOIUrl":"https://doi.org/10.4314/njt.v42i3.4","url":null,"abstract":"The polymerization and properties of environmentally friendly resin binders applicable in the surface-coating industry were studied. Rubber seed oil (RSO) and RSO blended with 10% and 20% soybean oil (SBO)-based alkyd resins were synthesized by alcoholysis- polyesterification of the oil with glycerol and phthalic anhydride. Physicochemical properties (such as colour, specific gravity, acid value, saponification value, iodine value, and drying schedule) of the alkyd resins were determined to establish the possible industrial potential of the resins. The saponification value and iodine value ranged from 250.19 mgKOH/g to 279.55 mgKOH/g and 29.58 gI2/100g to 33.77 gI2/100g respectively. The drying schedule and chemical resistance of the blended alkyd resins to water, salts, acids, and alkalis were also studied. The blended resins were found to be resistant to water, salt, and acid media, except for alkali media. The colour properties were enhanced as the percentage of the blend increased. FT-IR spectroscopic study of the oil and alkyd resin samples further corroborates our findings. Therefore, the potential of rubber seed oil blended with soybean oil to produce light-coloured alkyd resins could be exploited as raw materials for the Nigerian surface coating industry.","PeriodicalId":33360,"journal":{"name":"Nigerian Journal of Technology","volume":"24 14","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135875278","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

Groundwater quality assessment of aba urban area 阿坝市区地下水水质评价

Nigerian Journal of Technology Pub Date : 2023-11-03 DOI: 10.4314/njt.v42i3.3

B. Uwaoma, O.M. Ibearugbulem

{"title":"Groundwater quality assessment of aba urban area","authors":"B. Uwaoma, O.M. Ibearugbulem","doi":"10.4314/njt.v42i3.3","DOIUrl":"https://doi.org/10.4314/njt.v42i3.3","url":null,"abstract":"This work presents groundwater quality assessment of Aba Urban area and its sources of Contaminants within Aba Urban Area. Aba area was divided into nine parts using a 3x3 grid. Water samples were taken from each of these 9 parts of Aba. Five water samples were taken from household boreholes while four samples were taken from boreholes drilled and cased at the remaining four parts in the course of carrying out this research. Site and laboratory tests were conducted to determine the values water parameters in the samples. The parameters analysed in the laboratory include the Phosphate, ammonium, Lead, cadmium, Manganese, Copper, Mercury, Chromium, and magnesium, Electric conductivity (EC), Dissolved oxygen (DO), Total dissolved solid (TDS), Acidity, Turbidity, Alkalinity, oxidation- reduction potential (ORP), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD) and E-Coli. It was discovered that more than 75% of the water samples are contaminated by EColi. Umuagu sample has Manganese value of 0.775mg/l. This more than the limiting value of 0.4mg/l. The values 252, 524 and 472 mg/l of Magnesium in samples from Estate, Abia Polytechnic and Osisio Ngwa respectively are more than the limiting value of 150mg/l. The DO (mg/l) values of 6,4 and 9 from Ariaria Junction and Abia Polytechnic are outside the range limiting of 6.5mg/l – 8.0 mg/l. The values of TDS, ORP and BOD recorded in all the samples are below the limiting values of 600 mg/l, 357 mV and 1mg/l respectively.","PeriodicalId":33360,"journal":{"name":"Nigerian Journal of Technology","volume":"24 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135875283","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