Pub Date : 2018-08-09DOI: 10.1504/IJMSI.2018.10014944
Yanfang Zhao, Wei Ding, Hongcheng Wang, Qiao Dai
The effect of Mg doping on the electrical properties of pure ZnO and Al-doped ZnO, Al-2N co-doped ZnO have been investigated. It was found that after Mg doping, the bandgap values increased with the increase of Mg doping concentration. After Mg was doped into the Al doped ZnO structure, it was found that as the Mg doping contents increased, the CBM gradually moved toward the higher energy direction, the VBM gradually moved toward the lower energy direction, resulting in an increase of the band gap. After Mg was doped into the Al-2N co-doped structure, the band structure of Al-2N-Mg co-doped ZnO had a shallow acceptor level, indicating that the incorporation of Mg is beneficial for the electrical properties of p-type ZnO. The absorption of Al-2N-Mg co-doped ZnO is higher than that of Al-2N co-doped ZnO in the range of the visible region, which has a significant meaning for the applications on solar cell devices.
{"title":"Impact of Mg doping contents on the n-type and p-type ZnO by first-principles calculations","authors":"Yanfang Zhao, Wei Ding, Hongcheng Wang, Qiao Dai","doi":"10.1504/IJMSI.2018.10014944","DOIUrl":"https://doi.org/10.1504/IJMSI.2018.10014944","url":null,"abstract":"The effect of Mg doping on the electrical properties of pure ZnO and Al-doped ZnO, Al-2N co-doped ZnO have been investigated. It was found that after Mg doping, the bandgap values increased with the increase of Mg doping concentration. After Mg was doped into the Al doped ZnO structure, it was found that as the Mg doping contents increased, the CBM gradually moved toward the higher energy direction, the VBM gradually moved toward the lower energy direction, resulting in an increase of the band gap. After Mg was doped into the Al-2N co-doped structure, the band structure of Al-2N-Mg co-doped ZnO had a shallow acceptor level, indicating that the incorporation of Mg is beneficial for the electrical properties of p-type ZnO. The absorption of Al-2N-Mg co-doped ZnO is higher than that of Al-2N co-doped ZnO in the range of the visible region, which has a significant meaning for the applications on solar cell devices.","PeriodicalId":39035,"journal":{"name":"International Journal of Materials and Structural Integrity","volume":"12 1","pages":"194"},"PeriodicalIF":0.0,"publicationDate":"2018-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45337035","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}
Pub Date : 2018-08-09DOI: 10.1504/IJMSI.2018.10014931
S. Dauji
In the past, a few researchers predicted the compressive strength of concrete from its ingredients by employing artificial neural network (ANN). Evaluation of the models with different performance metrics, such as correlation coefficient and errors of estimation, indicated that there was scope for improvement in the prediction performance of ANN. In this paper development of prediction models has been carried out for superior performance with two concepts: single ANN and modular ANN. Experimental data from literature have been utilised for the study. Better overall performance of the developed ANN models than reported in the literature was ascertained by higher correlation, less root mean square error and mean absolute error. The performance of the modular ANN concept was superior to that of single ANN concept for the present application.
{"title":"Neural prediction of concrete compressive strength","authors":"S. Dauji","doi":"10.1504/IJMSI.2018.10014931","DOIUrl":"https://doi.org/10.1504/IJMSI.2018.10014931","url":null,"abstract":"In the past, a few researchers predicted the compressive strength of concrete from its ingredients by employing artificial neural network (ANN). Evaluation of the models with different performance metrics, such as correlation coefficient and errors of estimation, indicated that there was scope for improvement in the prediction performance of ANN. In this paper development of prediction models has been carried out for superior performance with two concepts: single ANN and modular ANN. Experimental data from literature have been utilised for the study. Better overall performance of the developed ANN models than reported in the literature was ascertained by higher correlation, less root mean square error and mean absolute error. The performance of the modular ANN concept was superior to that of single ANN concept for the present application.","PeriodicalId":39035,"journal":{"name":"International Journal of Materials and Structural Integrity","volume":"12 1","pages":"17"},"PeriodicalIF":0.0,"publicationDate":"2018-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45837232","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}
Pub Date : 2018-08-09DOI: 10.1504/IJMSI.2018.10014947
Chunquan Li, Ming Zhang, Y. Shang, Hua Yuwei
Cable assembly problem is formulated as searching for cable routes and the cable routing problem is one of the most challenging optimisation problems. Cable routing is the process of searching for obstacle-free path, which is constrained by the assembly points. Before routing, the routing environment is simplified to a two-dimensional grid map for computing reduction. In order to get the optimisation routing path, a novel approach of hybrid intelligent water drop algorithm (HIWDA) for cable routing is proposed, which is the hybridisation of particle swarm optimisation (PSO) and intelligent water drop algorithm (IWDA) for global searching and local searching respectively. In addition, B-spline curves are employed for smoothing routes obtained by HIWDA and making it more practical and more feasible for assembly. The result of HIWDA is verified by comparison with other algorithms in simulation on experiments.
{"title":"Research on the cable routing optimisation by hybrid intelligent water drop algorithm","authors":"Chunquan Li, Ming Zhang, Y. Shang, Hua Yuwei","doi":"10.1504/IJMSI.2018.10014947","DOIUrl":"https://doi.org/10.1504/IJMSI.2018.10014947","url":null,"abstract":"Cable assembly problem is formulated as searching for cable routes and the cable routing problem is one of the most challenging optimisation problems. Cable routing is the process of searching for obstacle-free path, which is constrained by the assembly points. Before routing, the routing environment is simplified to a two-dimensional grid map for computing reduction. In order to get the optimisation routing path, a novel approach of hybrid intelligent water drop algorithm (HIWDA) for cable routing is proposed, which is the hybridisation of particle swarm optimisation (PSO) and intelligent water drop algorithm (IWDA) for global searching and local searching respectively. In addition, B-spline curves are employed for smoothing routes obtained by HIWDA and making it more practical and more feasible for assembly. The result of HIWDA is verified by comparison with other algorithms in simulation on experiments.","PeriodicalId":39035,"journal":{"name":"International Journal of Materials and Structural Integrity","volume":"12 1","pages":"208"},"PeriodicalIF":0.0,"publicationDate":"2018-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42833243","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}
Pub Date : 2018-08-09DOI: 10.1504/IJMSI.2018.10014930
L. Fuyun, Wu Jianwei, Zhang Zhicong, Lu Hao, Li Kuan
To overcome the problem in currently studying train energy saving operation optimisation, the speed is selected as the design variable to establish the objective and constraint functions and train energy saving operation optimisation model. Taking a route optimisation as an example, the program of train energy saving operation optimisation based on MATLAB language is developed, and optimisation solution is accomplished by using the sequential quadratic programming (SQP) algorithm. Then, the distribution of each interval endpoint speed is obtained and the optimum speed-distance curve is designed. Optimisation results show that this handling research method is feasible and effective.
{"title":"Operation optimisation of urban rail transit train base on energy saving","authors":"L. Fuyun, Wu Jianwei, Zhang Zhicong, Lu Hao, Li Kuan","doi":"10.1504/IJMSI.2018.10014930","DOIUrl":"https://doi.org/10.1504/IJMSI.2018.10014930","url":null,"abstract":"To overcome the problem in currently studying train energy saving operation optimisation, the speed is selected as the design variable to establish the objective and constraint functions and train energy saving operation optimisation model. Taking a route optimisation as an example, the program of train energy saving operation optimisation based on MATLAB language is developed, and optimisation solution is accomplished by using the sequential quadratic programming (SQP) algorithm. Then, the distribution of each interval endpoint speed is obtained and the optimum speed-distance curve is designed. Optimisation results show that this handling research method is feasible and effective.","PeriodicalId":39035,"journal":{"name":"International Journal of Materials and Structural Integrity","volume":"12 1","pages":"1"},"PeriodicalIF":0.0,"publicationDate":"2018-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49538005","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}
Pub Date : 2018-08-09DOI: 10.1504/IJMSI.2018.10014949
Syed Abou Iltaf Hussain, S. Shabnam, U. Mandal, S. Mondal
After the discovery of carbon nanotubes (CNTs), a vast research is conducted on their application because of their unique mechanical and electronic properties. The comprehensive intention of this study is to propose a robust mathematical model to select the most suitable form of CNT in mechanical engineering application. One unique aspect of CNTs is that they exhibit different values for a mechanical property with maximum and minimum limits. For this reason the rating of the alternatives is in the form of interval values with respect to the criteria. The alternatives are the different forms of CNTs available that are used for mechanical engineering purposes, whereas the criteria are the different mechanical properties. Hence, selection of the most suitable CNT is a multi-criteria decision making (MCDM) problem under grey environment. Analytical hierarchy process (AHP) coupled with complex proportional assessment (COPRAS) and a technique for order preference by similarity to ideal solution (TOPSIS) method is proposed for the selection under grey environment. In order to test the robustness of the model, a sensitivity analysis for the proposed model is conducted.
{"title":"AHP coupled multi-criteria decision making approach for selection of carbon nanotube applied in mechanical engineering under grey-environment","authors":"Syed Abou Iltaf Hussain, S. Shabnam, U. Mandal, S. Mondal","doi":"10.1504/IJMSI.2018.10014949","DOIUrl":"https://doi.org/10.1504/IJMSI.2018.10014949","url":null,"abstract":"After the discovery of carbon nanotubes (CNTs), a vast research is conducted on their application because of their unique mechanical and electronic properties. The comprehensive intention of this study is to propose a robust mathematical model to select the most suitable form of CNT in mechanical engineering application. One unique aspect of CNTs is that they exhibit different values for a mechanical property with maximum and minimum limits. For this reason the rating of the alternatives is in the form of interval values with respect to the criteria. The alternatives are the different forms of CNTs available that are used for mechanical engineering purposes, whereas the criteria are the different mechanical properties. Hence, selection of the most suitable CNT is a multi-criteria decision making (MCDM) problem under grey environment. Analytical hierarchy process (AHP) coupled with complex proportional assessment (COPRAS) and a technique for order preference by similarity to ideal solution (TOPSIS) method is proposed for the selection under grey environment. In order to test the robustness of the model, a sensitivity analysis for the proposed model is conducted.","PeriodicalId":39035,"journal":{"name":"International Journal of Materials and Structural Integrity","volume":"12 1","pages":"224"},"PeriodicalIF":0.0,"publicationDate":"2018-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48884053","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}
Pub Date : 2018-08-09DOI: 10.1504/IJMSI.2018.10014950
W. Ma, Xiao fen Li
In order to have a clear understanding for the mechanical mechanism and cracking rules of steel lined reinforced concrete penstock laid on downstream surface of dam, this paper adopts nonlinear finite element theory to carry out force analysis. The research object of the paper chooses steel lined reinforced concrete penstock laid on downstream surface of dam for Longkaikou Hydropower Station, and a nonlinear finite element calculation model is built by the finite element software. Research results show that when the internal water pressure is smaller, the steel lined bears full load, when the internal water pressure increases to a certain value, the steel lined and reinforced concrete pipes bear the load jointly. With the increase of internal water pressure, the circumferential stress and radial stress of the steel lined and reinforced concrete pipes increase obviously, the bearing ratio of reinforced concrete pipe is gradually increasing, but the growth of bearing ratio is small. When the internal water pressure gradually increases, the circumferential stress value is significantly greater than the radial stress value, normally tensile damage along the radius direction of the reinforced concrete pipe happens.
{"title":"Nonlinear finite element analysis of steel lined reinforced concrete penstock laid on downstream surface of dam","authors":"W. Ma, Xiao fen Li","doi":"10.1504/IJMSI.2018.10014950","DOIUrl":"https://doi.org/10.1504/IJMSI.2018.10014950","url":null,"abstract":"In order to have a clear understanding for the mechanical mechanism and cracking rules of steel lined reinforced concrete penstock laid on downstream surface of dam, this paper adopts nonlinear finite element theory to carry out force analysis. The research object of the paper chooses steel lined reinforced concrete penstock laid on downstream surface of dam for Longkaikou Hydropower Station, and a nonlinear finite element calculation model is built by the finite element software. Research results show that when the internal water pressure is smaller, the steel lined bears full load, when the internal water pressure increases to a certain value, the steel lined and reinforced concrete pipes bear the load jointly. With the increase of internal water pressure, the circumferential stress and radial stress of the steel lined and reinforced concrete pipes increase obviously, the bearing ratio of reinforced concrete pipe is gradually increasing, but the growth of bearing ratio is small. When the internal water pressure gradually increases, the circumferential stress value is significantly greater than the radial stress value, normally tensile damage along the radius direction of the reinforced concrete pipe happens.","PeriodicalId":39035,"journal":{"name":"International Journal of Materials and Structural Integrity","volume":"12 1","pages":"261"},"PeriodicalIF":0.0,"publicationDate":"2018-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47960229","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}
Pub Date : 2018-08-09DOI: 10.1504/IJMSI.2018.10014937
Cuiying Yu, J. Xiang, Yang Zhou, Jianhong Mao, Kai Gong
To explore the influence of gap on deformation and deterioration stress of track structure, a finite element model of CRTS-I slab ballastless track with gap is established by ABAQUS on the basis of plastic damage constitutive relation of concrete. The effects of different sizes and different positions of gap on displacement and stress of the track structure are calculated and analysed. The influence law of gap on deformation and deterioration stress is drawn by comparison with the calculation of normal track structure. The results show that increasing gap size sharply increases vertical displacement of both rails and slab and also seriously deteriorates transversal and longitudinal stress on the track slab to a great extent. Moreover, the effect of gap at slab centre on deteriorated stress and deformation is less than that of gap at slab end. The study can obviously provide theoretical reference for the maintenance standard.
{"title":"Effect of gap on vertical deformation and deterioration stress of CRTS-I ballastless track","authors":"Cuiying Yu, J. Xiang, Yang Zhou, Jianhong Mao, Kai Gong","doi":"10.1504/IJMSI.2018.10014937","DOIUrl":"https://doi.org/10.1504/IJMSI.2018.10014937","url":null,"abstract":"To explore the influence of gap on deformation and deterioration stress of track structure, a finite element model of CRTS-I slab ballastless track with gap is established by ABAQUS on the basis of plastic damage constitutive relation of concrete. The effects of different sizes and different positions of gap on displacement and stress of the track structure are calculated and analysed. The influence law of gap on deformation and deterioration stress is drawn by comparison with the calculation of normal track structure. The results show that increasing gap size sharply increases vertical displacement of both rails and slab and also seriously deteriorates transversal and longitudinal stress on the track slab to a great extent. Moreover, the effect of gap at slab centre on deteriorated stress and deformation is less than that of gap at slab end. The study can obviously provide theoretical reference for the maintenance standard.","PeriodicalId":39035,"journal":{"name":"International Journal of Materials and Structural Integrity","volume":"12 1","pages":"76"},"PeriodicalIF":0.0,"publicationDate":"2018-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44839991","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}
Pub Date : 2018-08-09DOI: 10.1504/IJMSI.2018.10014943
Zhi-an Huang, Shanlin Xiao, W. Lu, Yukun Gao, Yinghua Zhang, Wang Hui
Spontaneous coal combustion poses serious threats to the world and especially to China, the world's largest coal producer and user. Apart from spurring monetary losses in national exchequers and resource losses for countries, spontaneous coal combustion results in a loss of life, which cannot be measured based on costs. Innumerable researchers and scholars in China and abroad have paid considerable attention to studying means of protecting materials from spontaneous coal combustion. A variety of materials that prevent spontaneous coal combustion have been developed. The goal of this paper is reveal the academic literature on spontaneous coal combustion. In this comprehensive review, mechanisms of spontaneous coal combustion, research findings and advantages and shortcomings of materials that prevent spontaneous coal combustion are explored. In view of different coal mining conditions and material properties, materials that prevent spontaneous coal combustion are classified in accordance with material phases. The development of various coal fire extinguishing materials is discussed. Our comprehensive review can thus be used to prevent and control spontaneous coal combustion and to curtail the currently frequent disasters resulting from spontaneous coal combustion.
{"title":"Means of protecting materials from spontaneous coal combustion: current developments, mechanisms, classifications, and prospects","authors":"Zhi-an Huang, Shanlin Xiao, W. Lu, Yukun Gao, Yinghua Zhang, Wang Hui","doi":"10.1504/IJMSI.2018.10014943","DOIUrl":"https://doi.org/10.1504/IJMSI.2018.10014943","url":null,"abstract":"Spontaneous coal combustion poses serious threats to the world and especially to China, the world's largest coal producer and user. Apart from spurring monetary losses in national exchequers and resource losses for countries, spontaneous coal combustion results in a loss of life, which cannot be measured based on costs. Innumerable researchers and scholars in China and abroad have paid considerable attention to studying means of protecting materials from spontaneous coal combustion. A variety of materials that prevent spontaneous coal combustion have been developed. The goal of this paper is reveal the academic literature on spontaneous coal combustion. In this comprehensive review, mechanisms of spontaneous coal combustion, research findings and advantages and shortcomings of materials that prevent spontaneous coal combustion are explored. In view of different coal mining conditions and material properties, materials that prevent spontaneous coal combustion are classified in accordance with material phases. The development of various coal fire extinguishing materials is discussed. Our comprehensive review can thus be used to prevent and control spontaneous coal combustion and to curtail the currently frequent disasters resulting from spontaneous coal combustion.","PeriodicalId":39035,"journal":{"name":"International Journal of Materials and Structural Integrity","volume":"12 1","pages":"125"},"PeriodicalIF":0.0,"publicationDate":"2018-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42497322","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}
Pub Date : 2018-08-09DOI: 10.1504/IJMSI.2018.10014938
Haiyan Hu, C. Tian, Jiandong Yang
Burrs on cross hole on automobile brake master cylinder have an impact on service life and stability of the hydraulic braking system. Therefore, as for how to remove burrs on cross hole, this paper provides a flexible machining technology for deburring with the liquid impact-based fatigue fracture method. Firstly, a reasonable 3D model was established. Then Fluent software was used to conduct a numerical simulation analysis on inner flow passage of brake master cylinder in order to calculate the force condition of burrs surrounded by hydraulic oil. Next, modal analysis and harmonic response analysis on burrs were further conducted to calculate and analyse resonant frequency of burrs and verify feasibility of this method, which provides a reliable theoretical foundation for deburring methods for automobile brake master cylinder. In addition, machining technology of this method was optimised and a more reasonable machining plan was put forward, which was then applied on a machining platform and achieved great machining effect.
{"title":"Research on deburring technology for cross hole on automobile brake master cylinder","authors":"Haiyan Hu, C. Tian, Jiandong Yang","doi":"10.1504/IJMSI.2018.10014938","DOIUrl":"https://doi.org/10.1504/IJMSI.2018.10014938","url":null,"abstract":"Burrs on cross hole on automobile brake master cylinder have an impact on service life and stability of the hydraulic braking system. Therefore, as for how to remove burrs on cross hole, this paper provides a flexible machining technology for deburring with the liquid impact-based fatigue fracture method. Firstly, a reasonable 3D model was established. Then Fluent software was used to conduct a numerical simulation analysis on inner flow passage of brake master cylinder in order to calculate the force condition of burrs surrounded by hydraulic oil. Next, modal analysis and harmonic response analysis on burrs were further conducted to calculate and analyse resonant frequency of burrs and verify feasibility of this method, which provides a reliable theoretical foundation for deburring methods for automobile brake master cylinder. In addition, machining technology of this method was optimised and a more reasonable machining plan was put forward, which was then applied on a machining platform and achieved great machining effect.","PeriodicalId":39035,"journal":{"name":"International Journal of Materials and Structural Integrity","volume":"12 1","pages":"110"},"PeriodicalIF":0.0,"publicationDate":"2018-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43896706","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}
The regulation of methane occurrence is critical for gas control. Through liquid nitrogen adsorption, isothermal adsorption/desorption of methane and electrical experiments with undeformed and deformed coal, this paper studies the microscopic characteristics of methane occurrence. The results show: the median-pore-dominant deformed coal has less specific surface area and pore volume than the undeformed coal, which has mainly micropores and small pores; the deformed coal has greater methane absorption ability than the undeformed coal, and the negative influence of temperature on the former is more notable; the resistivity of deformed coal is three to seven times that of undeformed coal, and when adsorbing the resistivity of both coals decreases before being stable, whereas their dielectric constant rises first, then slightly declines. The results of the three experiments are in good accordance. The research is basic for coalbed gas and may provide a new thought for gas control.
{"title":"Microscopic characteristics of the methane occurrence state in coal","authors":"Zhi-an Huang, Zhenzheng Ma, Rui Yang, Yukun Gao, Yinghua Zhang, X. Gong","doi":"10.1504/IJMSI.2018.10014945","DOIUrl":"https://doi.org/10.1504/IJMSI.2018.10014945","url":null,"abstract":"The regulation of methane occurrence is critical for gas control. Through liquid nitrogen adsorption, isothermal adsorption/desorption of methane and electrical experiments with undeformed and deformed coal, this paper studies the microscopic characteristics of methane occurrence. The results show: the median-pore-dominant deformed coal has less specific surface area and pore volume than the undeformed coal, which has mainly micropores and small pores; the deformed coal has greater methane absorption ability than the undeformed coal, and the negative influence of temperature on the former is more notable; the resistivity of deformed coal is three to seven times that of undeformed coal, and when adsorbing the resistivity of both coals decreases before being stable, whereas their dielectric constant rises first, then slightly declines. The results of the three experiments are in good accordance. The research is basic for coalbed gas and may provide a new thought for gas control.","PeriodicalId":39035,"journal":{"name":"International Journal of Materials and Structural Integrity","volume":"12 1","pages":"151"},"PeriodicalIF":0.0,"publicationDate":"2018-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44438319","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}
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