Nigerian Journal of Technological Development最新文献_第8页

Nonlinear Time History Analysis for Seismic Effects on Reinforced Concrete Building 钢筋混凝土建筑地震作用的非线性时程分析

Nigerian Journal of Technological Development Pub Date : 2023-01-28 DOI: 10.4314/njtd.v19i4.12

A. Hasan, K. Iqbal, S. Ahammed, A. Ghosh

{"title":"Nonlinear Time History Analysis for Seismic Effects on Reinforced Concrete Building","authors":"A. Hasan, K. Iqbal, S. Ahammed, A. Ghosh","doi":"10.4314/njtd.v19i4.12","DOIUrl":"https://doi.org/10.4314/njtd.v19i4.12","url":null,"abstract":"A typical Reinforced Concrete (RC) building frame comprising of RC columns and connecting beams that participates in resisting the earthquake forces. Due to earthquake, reversal tension generates at both faces of a beam and column; and hence damage occur in the frame for the disability of tension carrying capacity of concrete. Therefore, the structural performance of RC building for seismic load has been analyzed by nonlinear time history analysis method for this study. A residential building located in Dhaka, Bangladesh subjected to various types of gravity load and seismic load was considered to analyze using ETABS software as per the guideline of BNBC (2020). According to the guideline of ATC 40 (1996), the seismic performances like maximum displacement and story drift for RC building were evaluated both at structural and element levels by applying El Centro (1940) ground motion at the base of the structure. Formation of plastic hinges is used as the basis to evaluate the local performance and story drift is used to evaluate the global performance. At first, the considered building was designed only for gravity load, and then for both gravity and seismic load according to BNBC (2020). Further studies have been performed on that building considering double height column at a story level. It was observed that the maximum displacement and story drift exceeds the allowable limit for all the considered cases if seismic load is applied on the structure.","PeriodicalId":31273,"journal":{"name":"Nigerian Journal of Technological Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48199706","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

Effect of Thermal Screen Position on Greenhouse Microclimate and Impact on Crop Growth and Yield 热屏位置对温室小气候的影响及其对作物生长和产量的影响

Nigerian Journal of Technological Development Pub Date : 2023-01-28 DOI: 10.4314/njtd.v19i4.15

E. Zakir, Q. O. Ogunlowo, T. D. Akpenpuun, W. Na, M. A. Adesanya, A. Rabiu, O. Adedeji, H. Kim, H-W. Lee

{"title":"Effect of Thermal Screen Position on Greenhouse Microclimate and Impact on Crop Growth and Yield","authors":"E. Zakir, Q. O. Ogunlowo, T. D. Akpenpuun, W. Na, M. A. Adesanya, A. Rabiu, O. Adedeji, H. Kim, H-W. Lee","doi":"10.4314/njtd.v19i4.15","DOIUrl":"https://doi.org/10.4314/njtd.v19i4.15","url":null,"abstract":"Worldwide, researchers are developing methods in which producers can obtain higher yields and conserve more energy in greenhouse crop cultivation. To achieve this, thermal screens are deployed during cold nights and rolled up during the daytime. The positioning of these screens causes a reduction in the amount of solar radiation (SR) received by greenhouses, especially the single span. The impact of thermal screen position on the receipt of SR, temperature, relative humidity (RH), vapour pressure deficit (VPD), fuel consumption, and the consequent effects on crop yield and growth were investigated in this study. Two greenhouses with similar dimensions and structure but different thermal screen positions were designed, namely R-greenhouse (RGH) with thermal screens at the centre of the roof and Q-greenhouse (QGH) at five degrees (5o) Northward. Strawberries were cultivated as study crops. Statistical analysis of the recorded data of greenhouse microclimate parameters, crop growth, and yield showed that both greenhouses performed similarly in energy savings, and there was no significant difference regarding temperature, RH, and VPD. However, there were significant differences in the crop growth and yield obtained in the QGH compared to RGH. This can be attributed to the higher amount of SR received by the QGH than the SR that was received by the RGH, which was achieved because the thermal screen was installed on the north side of the Q greenhouse.","PeriodicalId":31273,"journal":{"name":"Nigerian Journal of Technological Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41468428","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

Effects of Geometric Ratios on Heat Transfer in Heated Cylinders: Modelling and Simulation 几何比对加热圆柱体传热的影响:建模与仿真

Nigerian Journal of Technological Development Pub Date : 2023-01-28 DOI: 10.4314/njtd.v19i4.1

O. Olayemi, A. Obalalu, S. E. Ibitoye, A. Salaudeen, M. Ibiwoye, B. E. Anyaegbuna, I. K. Adegun

{"title":"Effects of Geometric Ratios on Heat Transfer in Heated Cylinders: Modelling and Simulation","authors":"O. Olayemi, A. Obalalu, S. E. Ibitoye, A. Salaudeen, M. Ibiwoye, B. E. Anyaegbuna, I. K. Adegun","doi":"10.4314/njtd.v19i4.1","DOIUrl":"https://doi.org/10.4314/njtd.v19i4.1","url":null,"abstract":"The application of fluid and heat transfer in electronic and nuclear technology is gaining popularity, particularly in equipment's life span and risk management. However, further study is required for applications involving rectangular cylinders placed inside a square cavity. This study investigates the effects of height ratio (𝐻𝑅), and width ratio (𝑊𝑅) for Prandtl number 𝑃𝑟=0.71 on natural convective heat transfer and the flow field around the annulus of a square domain fitted internally with a heated rectangular cylinder. The square enclosure and the inner rectangular cylinder walls were respectively maintained at cold and hot isothermal conditions. COMSOL Multiphysics (Version 5.6) software was adopted to implement the governing equations and boundary conditions. The results are presented in the form of streamlines, isothermal contours, and Nusselt number (Nu). The study reveals that the combined average Nu of the rectangular cylinder walls improves with 𝐻𝑅, 𝑊𝑅, and Rayleigh number (Ra). The maximum Nu occurred at 𝐻𝑅=0.7, and 𝑊𝑅=0.7; however, height variation at peak average Nu was 37.7% greater than width variation at peak average Nu. This study finds applications in the cooling of electronic chips and aerospace engines.","PeriodicalId":31273,"journal":{"name":"Nigerian Journal of Technological Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42636007","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 Forced Convection Heat Transfer, Fluid Flow and Entropy Generation Analyses of Al2O3- Water Nanofluid in Elliptical Channels 椭圆通道中Al2O3-水纳米流体的数值强制对流换热、流体流动和熵产分析

Nigerian Journal of Technological Development Pub Date : 2023-01-28 DOI: 10.4314/njtd.v19i4.9

O. T. Olakoyejo, A. O. Adelaja, S. M. Abolarin, O. Adewumi, M. Oyekeye, A. Oluwo, O. Oluwatusin, A. Mweigye

{"title":"Numerical Forced Convection Heat Transfer, Fluid Flow and Entropy Generation Analyses of Al2O3- Water Nanofluid in Elliptical Channels","authors":"O. T. Olakoyejo, A. O. Adelaja, S. M. Abolarin, O. Adewumi, M. Oyekeye, A. Oluwo, O. Oluwatusin, A. Mweigye","doi":"10.4314/njtd.v19i4.9","DOIUrl":"https://doi.org/10.4314/njtd.v19i4.9","url":null,"abstract":"This study investigates a three-dimensional elliptical microchannel heat sink for heat dissipation in laminar forced convection. The study seeks to improve thermal performance and overcome overheating associated with excessive temperature commonly experienced in heat-generating equipment, which is beyond the temperature usually specified by the manufacturer. The objective of the study is to evaluate the heat transfer, fluid flow, and entropy generation characteristics of Al2O3-water nanofluid in an elliptical cooling channel. The numerical analysis is investigated on the structure experiencing constant volumetric heat generation. The parameters considered are Reynolds number of 100 ≤ Re ≤ 500, nanoparticle concentration ϕ, from 0% to 4% with channel aspect ratio Ar from 1 to 3. The impacts of these parameters on the maximum temperature, heat transfer coefficient, friction factor, and volumetric entropy generation are reported. The study demonstrates that heat transfer is enhanced in the elliptical cooling channel at different aspect ratios, nanoparticle concentrations, and Reynold numbers. The results showed that as the nanoparticle concentration, channel aspect ratio, and Reynolds number (Re) increase, the maximum temperature, and total entropy generation decrease. As the channel aspect ratio increases at a specified Re = 200 and nanofluid concentration, ɸ = 3%, the maximum temperature, and total entropy generation decrease by up to 62% while the heat transfer coefficient increases by up to 78% and the friction factor increase by less than 2% with aspect ratio. However, the friction factor is not sensitive to the nanofluid concentration as a coolant.","PeriodicalId":31273,"journal":{"name":"Nigerian Journal of Technological Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42109076","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

Assessing Social Sustainability Performance in Textile Industry using Integrated Fuzzy Best-Worst Method and Fuzzy Inference System 基于模糊最优-最差综合评判法和模糊推理系统的纺织工业社会可持续性评价

Nigerian Journal of Technological Development Pub Date : 2023-01-28 DOI: 10.4314/njtd.v19i4.7

T. G. Fadara, K. Y. Wong

引用次数: 0

Morphology and Physico-Mechanical Properties of Resin-bonded Palm Kernel Shell and Coconut Shell Grain-based Sandpaper Composites 树脂粘合棕榈果壳和椰子果壳颗粒基砂纸复合材料的形态和物理力学性能

Nigerian Journal of Technological Development Pub Date : 2023-01-28 DOI: 10.4314/njtd.v19i4.11

H. A. Ajimotokan, A. A. Samuel, T. Ajiboye, T. Ogedengbe, I. O. Alabi

{"title":"Morphology and Physico-Mechanical Properties of Resin-bonded Palm Kernel Shell and Coconut Shell Grain-based Sandpaper Composites","authors":"H. A. Ajimotokan, A. A. Samuel, T. Ajiboye, T. Ogedengbe, I. O. Alabi","doi":"10.4314/njtd.v19i4.11","DOIUrl":"https://doi.org/10.4314/njtd.v19i4.11","url":null,"abstract":"Due to the challenges associated with using crude oil-derived phenolic- or thermoplastics-based materials, agro-based composites have been used as alternative abrasive grains for abrasive tool manufacturing. This paper examines the morphology and physico-mechanical properties of resin-bonded palm kernel shell (PKS) and coconut shell (CNS) grain-based sandpaper composites and their wear performance. The PKS and CNS were collected, pulverised and screened into 250 and 500 μm grainsizes and mixed at ratios of 1:1, 1:2 and 2:1, respectively. Methyl-ethyl-ketone-peroxide and cobalt naphthalene of 1.5 wt. % each were utilised as hardener and catalyst, respectively for proper bonding of the aggregates with unsaturated polyester resin of compositions 12, 15, 18, 21 and 24 wt. %, respectively. To produce the sandpaper samples, the aggregates were compacted at a pressure of 15 MPa and the samples were cured and their morphology, mechanical, and wear properties were investigated.The shatter index, hardness, and compressive strength varied from 66.36% to 95.76%, 6.52 to 11.3 HRB, and 4.41 to 7.24 MPa, respectively. The wear resistance varied from 0.94 to 1.54 mg/m at 50 oC, and 1.02 to 2.09 mg/m at 150 oC. The properties of the aggregates made from PKS and CNS were found to have much influence on the performance parameters of sandpaper composites.","PeriodicalId":31273,"journal":{"name":"Nigerian Journal of Technological Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44085750","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

Selection of Wireless Communication Technologies for Embedded Devices using Multi-criteria Approach and Expert Opinion 基于多准则方法和专家意见的嵌入式设备无线通信技术选择

Nigerian Journal of Technological Development Pub Date : 2023-01-28 DOI: 10.4314/njtd.v19i4.10

J. Adebisi, O. Babatunde

{"title":"Selection of Wireless Communication Technologies for Embedded Devices using Multi-criteria Approach and Expert Opinion","authors":"J. Adebisi, O. Babatunde","doi":"10.4314/njtd.v19i4.10","DOIUrl":"https://doi.org/10.4314/njtd.v19i4.10","url":null,"abstract":"Emerging research has shown the significance of communication technologies in the development of embedded systems and devices. Since there are various communication technologies with varying advantages and disadvantages in embedded systems, decision makers in identifying the best alternative can be prejudiced by various features. Hence, making the selection of the most suitable wireless communication technology a multi-criteria problem. To rank the common wireless communication technologies relevant to the development of embedded systems, this paper presents a multi-criteria decision making (MCDM) approach for analyzing experts opinion on the most preferred wireless communication technologies for embedded devices. To accommodate the subjective nature of experts’ responses, a Fuzzy-TOPSIS MCDM approach is proposed for the ranking wireless communication technologies that can be adopted in the development of embedded systems. Based on the aggregation of responses from experts, the results show that the most preferred wireless communication alternative for embedded application is Wi-Fi with a closeness coefficient (𝐶𝐶𝑖) of 0.52, while the least preferred alternative is Long-Term Evolution (LTE) with a (𝐶𝐶𝑖) 0.32.","PeriodicalId":31273,"journal":{"name":"Nigerian Journal of Technological Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42953251","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: 5

Short-term Study of the Influence of Aggregate Size on the Fire Resistance of Concrete 骨料粒径对混凝土耐火性能影响的短期研究

Nigerian Journal of Technological Development Pub Date : 2023-01-28 DOI: 10.4314/njtd.v19i4.5

F. Ayodele, O. R. Olulope, I. Ayeni

{"title":"Short-term Study of the Influence of Aggregate Size on the Fire Resistance of Concrete","authors":"F. Ayodele, O. R. Olulope, I. Ayeni","doi":"10.4314/njtd.v19i4.5","DOIUrl":"https://doi.org/10.4314/njtd.v19i4.5","url":null,"abstract":"This study aims to investigate the effect of aggregate size on the fire resistance of concrete. The binder for this investigation was 42.5R CEM II/A-L Portland limestone cement, and the crushed granite sizes were 20mm, 12.5mm, and a blend (20 mm + 12.5 mm). The concrete was designed with a mix ratio of 1:2:4 (batching by weight) and 0.55w/c. The workability of the concrete was determined using the slump method. The concrete specimens were cured for 7, 14, and 28 days by immersion and later exposed to heat temperatures of 26.8 °C (Room temperature), 60 °C, 120 °C, 180 °C, and 240 °C. The compressive strength of normal concrete (without heating) had the optimum with concrete produced with blended aggregate size and conversely the least with 20mm aggregate size concrete. When subjected to heat, the optimal performance noted for the influence of aggregate size on fire resistance was also with concrete produced with combined blend (20 mm + 12.5 mm) sizes. The p-value (Prob > F) for the whole model test is less than 0.05, indicating that there is a significant relationship between the grain size, temperature, and strength loss. The use of blended sizes of 12.5 mm and 20 mm is therefore recommended for concrete works and especially when fire resistance is a requirement.","PeriodicalId":31273,"journal":{"name":"Nigerian Journal of Technological Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46115048","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

Valorization of Sugarcane Bagasse for Hydrogen-Rich Gas Production using Thermodynamic Modeling Approach 利用热力学建模方法对甘蔗渣富氢气产气进行数值模拟

Nigerian Journal of Technological Development Pub Date : 2023-01-28 DOI: 10.4314/njtd.v19i4.14

S. Mustapha, I. Mohammed, F. Aderibigbe, T. L. Adewoye, F. O. Omoarukhe, A. O. Sowole

{"title":"Valorization of Sugarcane Bagasse for Hydrogen-Rich Gas Production using Thermodynamic Modeling Approach","authors":"S. Mustapha, I. Mohammed, F. Aderibigbe, T. L. Adewoye, F. O. Omoarukhe, A. O. Sowole","doi":"10.4314/njtd.v19i4.14","DOIUrl":"https://doi.org/10.4314/njtd.v19i4.14","url":null,"abstract":"Hydrothermal gasification also known as supercritical water gasification (SWG) has been considered a promising approach for converting wet biomass such as sugarcane bagasse into high-quality syngas. This study presents the thermodynamic modeling of the hydrothermal gasification of sugarcane bagasse using Aspen Plus. The effects of process parameters on the composition and yield of product gases were also investigated. It was found that the effect of temperature and biomass concentration were significant in the production of hydrogen-rich gas, while less impact was observed with pressure. The hydrogen gas (H2) produced with the highest mole fraction (56.70 mol%) and yield (103.26 kmol/kg) was obtained at 750°C and low biomass concentration of 10 wt%, while the lowest yield (1.52 kmol/kg) and mole fraction (2.45 mol%) of H2 were obtained at 450°C and high biomass concentration of 50 wt%. Findings from this study also showed that the highest net calorific value (17.55MJ/kg) was reached at 450˚C and 50 wt% of biomass concentration. This study would help to consolidate research on hydrothermal gasification of sugarcane bagasse and optimization of experimental processes and also serve as an important benchmark in the utilization of biomass as a clean energy source for future projects.","PeriodicalId":31273,"journal":{"name":"Nigerian Journal of Technological Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43263364","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

Determination of Aquifer Hydraulic Characteristics from Surface Electrical and Borehole Measurements in Ozoro, Nigeria 根据尼日利亚Ozoro的地面电和钻孔测量确定含水层水力特征

Nigerian Journal of Technological Development Pub Date : 2022-09-23 DOI: 10.4314/njtd.v19i3.6

Merrious Oviri Ofomola, O. P. Otheremu, O. Ohwoghere-Asuma, O. Anomohanran

{"title":"Determination of Aquifer Hydraulic Characteristics from Surface Electrical and Borehole Measurements in Ozoro, Nigeria","authors":"Merrious Oviri Ofomola, O. P. Otheremu, O. Ohwoghere-Asuma, O. Anomohanran","doi":"10.4314/njtd.v19i3.6","DOIUrl":"https://doi.org/10.4314/njtd.v19i3.6","url":null,"abstract":"Surface electrical and borehole measurements were undertaken in order to establish the hydraulic characteristics of alluvial aquifer in Ozoro, Delta State. Ten vertical electrical sounding data were acquired using Schlumberger Configuration. Borehole measurements which included pumping test, well logging and the distribution of grain size analysis were also carried out. The results of the electrical sounding indicate that the aquiferous layer is located between the fourth and fifth layers with resistivity ranged from 53.5 Ωm - 1279 Ωm. The aquifer thickness ranged from 7.67 m - 49.4 m and transmissivity values ranged from 41.4 - 330.5 𝑚2/day. The average hydraulic conductivity (k) value obtained is 6.2 m/day. The borehole lithology, resistivity and spontaneous potential log indicate the subsurface lithology to consists of top soil (brownish), clayey sand, clay, fine sand and gravelly sand. The Cooper Jacob solution was used in the analysis of the borehole pumping experiment and the obtained hydraulic conductivity, transmissivity, storativity and specific capacity are 6.8 m/day, 0.067 m2/min (96.48 𝑚2/day), 25.47 and 0.364 m2/min (524.6 m2/day) respectively. Also, the grain size distribution analysis using the Hazen approximation gave hydraulic conductivity as 11.55 m/day. The results showed that all three methods are applicable for determining aquifer hydraulic parameters.","PeriodicalId":31273,"journal":{"name":"Nigerian Journal of Technological Development","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47216542","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