B. Milenković, Danilo Karličić, Mladen Krstić, Đorđe E Jovanović
Free transverse vibration of a Rayleigh double-beam system with the effect of compressive axial load with a Keer layer in-between is studied in this paper. It is assumed that the two beams of the system are continuously joined by the Keer layer. The equations of the motion for this system are described by a set of three homogenous differential equations. The classic Bernoulli-Fourier method was used for solving this system of differential equations. In the research found in literature on the subject of the Keer model, the most common methods used are the theories of Timoshenko and Euler-Bernoulli. It is for that exact reason that the research goal of this paper is determining analytical and numerical characteristics (natural frequency, associated amplitude ratio) of the considered model by applying the Rayleigh theory. What is also researched is the effect of elastic in-between layer on system's frequency and amplitudes. The numerical analysis of the system was performed using software tools. The numerical results obtained are shown in the form of a plot diagram. Presented numerical results in this paper confirm those obtained in the literature.
{"title":"Free transverse vibration analysis of a Rayleigh double-beam system with a Keer middle layer subjected to compressive axial load","authors":"B. Milenković, Danilo Karličić, Mladen Krstić, Đorđe E Jovanović","doi":"10.5937/str2102036m","DOIUrl":"https://doi.org/10.5937/str2102036m","url":null,"abstract":"Free transverse vibration of a Rayleigh double-beam system with the effect of compressive axial load with a Keer layer in-between is studied in this paper. It is assumed that the two beams of the system are continuously joined by the Keer layer. The equations of the motion for this system are described by a set of three homogenous differential equations. The classic Bernoulli-Fourier method was used for solving this system of differential equations. In the research found in literature on the subject of the Keer model, the most common methods used are the theories of Timoshenko and Euler-Bernoulli. It is for that exact reason that the research goal of this paper is determining analytical and numerical characteristics (natural frequency, associated amplitude ratio) of the considered model by applying the Rayleigh theory. What is also researched is the effect of elastic in-between layer on system's frequency and amplitudes. The numerical analysis of the system was performed using software tools. The numerical results obtained are shown in the form of a plot diagram. Presented numerical results in this paper confirm those obtained in the literature.","PeriodicalId":33842,"journal":{"name":"Scientific Technical Review","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71085134","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}
Biologically inspired algorithms are becoming powerful in modern optimization. In this paper, the principles of a metaheuristic algorithm based on Harris hawks behavior are shown. The Harris Hawks Optimizer (HHO in short) was used for solving problems in applied mechanics (car side impact, cone clutch, three-dimensional beam and I beam optimization). In the end, a comparison of the results obtained by HHO and results obtained by other methods is given.
{"title":"The use of the biological algorithm in solving applied mechanics design problems","authors":"B. Milenković, Đorđe E Jovanović","doi":"10.5937/str2101038m","DOIUrl":"https://doi.org/10.5937/str2101038m","url":null,"abstract":"Biologically inspired algorithms are becoming powerful in modern optimization. In this paper, the principles of a metaheuristic algorithm based on Harris hawks behavior are shown. The Harris Hawks Optimizer (HHO in short) was used for solving problems in applied mechanics (car side impact, cone clutch, three-dimensional beam and I beam optimization). In the end, a comparison of the results obtained by HHO and results obtained by other methods is given.","PeriodicalId":33842,"journal":{"name":"Scientific Technical Review","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71085111","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}
Imaging sensor development results, achieved in the past four decades, provide increased camera capabilities both in day and night conditions. Due to advanced camera performances, we are experiencing a wide application of the imaging sensors in various areas, e.g. machine vision, mobile technology, autonomous vehicle driving, smart city scenarios, and scientific imaging. Low light level sensitivity, supporting camera night vision capability, leads to new applications in the security systems. Accordingly, the new needs of the camera testing procedures appear. Advanced camera performances also require a new approach to imaging sensor and camera testing and parameter definition. The short review of the current achievements in the area of low light camera technology developments is presented as a basis to illustrate the importance of their application and proper metrological support development. The review of the most important low light camera parameters and related measurement and testing methods is set to point out the needs for new low light camera testing procedures development.
{"title":"Low light level digital camera quality assessment","authors":"B. Livada, D. Peric, S. Vujic","doi":"10.5937/str2102003l","DOIUrl":"https://doi.org/10.5937/str2102003l","url":null,"abstract":"Imaging sensor development results, achieved in the past four decades, provide increased camera capabilities both in day and night conditions. Due to advanced camera performances, we are experiencing a wide application of the imaging sensors in various areas, e.g. machine vision, mobile technology, autonomous vehicle driving, smart city scenarios, and scientific imaging. Low light level sensitivity, supporting camera night vision capability, leads to new applications in the security systems. Accordingly, the new needs of the camera testing procedures appear. Advanced camera performances also require a new approach to imaging sensor and camera testing and parameter definition. The short review of the current achievements in the area of low light camera technology developments is presented as a basis to illustrate the importance of their application and proper metrological support development. The review of the most important low light camera parameters and related measurement and testing methods is set to point out the needs for new low light camera testing procedures development.","PeriodicalId":33842,"journal":{"name":"Scientific Technical Review","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71085179","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}
Younes Djemaoune, Branimir Krstic, Daniel Radulović, Stefan Rasic, Marjan Dodić
In the present study, a numerical investigation of three-point bending test of the open-hole damaged sandwich structures with Nomex TM honeycomb core and aluminium alloy skins is carried out. In order to evaluate the degradation of the mechanical properties of these damaged structures, a finite element model is realized and tested using Abaqus/Explicit. To validate the accuracy of the numerical model, the obtained numerical results of the intact panels are calibrated with the experimental results. The load-displacement curves of the damaged structures showed a significant decrease of the peak force and the flexural elastic modulus compared to the intact ones. The study indicated that the degradation level of these mechanical parameters is in a direct relationship with the damage size. In addition, the energy absorption of the damaged panels is calculated and compared to the intact one.
{"title":"Numerical investigation of open-hole damaged Nomex™ honeycomb panel under three-point bending load","authors":"Younes Djemaoune, Branimir Krstic, Daniel Radulović, Stefan Rasic, Marjan Dodić","doi":"10.5937/str2102014d","DOIUrl":"https://doi.org/10.5937/str2102014d","url":null,"abstract":"In the present study, a numerical investigation of three-point bending test of the open-hole damaged sandwich structures with Nomex TM honeycomb core and aluminium alloy skins is carried out. In order to evaluate the degradation of the mechanical properties of these damaged structures, a finite element model is realized and tested using Abaqus/Explicit. To validate the accuracy of the numerical model, the obtained numerical results of the intact panels are calibrated with the experimental results. The load-displacement curves of the damaged structures showed a significant decrease of the peak force and the flexural elastic modulus compared to the intact ones. The study indicated that the degradation level of these mechanical parameters is in a direct relationship with the damage size. In addition, the energy absorption of the damaged panels is calculated and compared to the intact one.","PeriodicalId":33842,"journal":{"name":"Scientific Technical Review","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71085287","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}
Marko Radovanović, A. Petrovski, Vinko Žindrašič, Aca Ranđelović
Unmanned aerial vehicles represent an indispensable segment in the range of weapons of both military and police units. The expansion in development of unmanned aerial vehicles for both commercial and military purposes has created a need for constant improvement of drones and anti-drone means. A wide range of possibilities opens up a wide range of uses for them. The paper presents the choice of an unmanned aerial vehicle as an important combat system for the needs of tactical units of the army and police. The complexity of the problem is conditioned by various tactical-technical and economic characteristics of unmanned aerial vehicles, it has conditioned the use of different methods of multicriteria decision making. A hybrid model of multicriteria decision making fuzzy AHP-VIKOR was used to select the unmanned aerial vehicle for the needs of tactical units. Criteria of importance for the selection of an unmanned aerial vehicle for the needs of tactical units have been defined on the basis of which the most optimal solution (unmanned aerial vehicle) has been selected. The criteria are defined on the basis of tactical-technical and economic characteristics of unmanned aerial vehicles. The calculation of the weight coefficients of the defined criteria was performed using the fuzzy AHP method, while the selection of the drone (the most favorable alternative) based on the defined criteria was performed using the VIKOR method. The obtained result represents the starting point for further research and implementation of unmanned aerial vehicles in tactical units of the army and police.
{"title":"Application of the Fuzzy AHP -VIKOR hybrid model in the selection of an unmanned aircraft for the needs of tactical units of the armed forces","authors":"Marko Radovanović, A. Petrovski, Vinko Žindrašič, Aca Ranđelović","doi":"10.5937/str2102026r","DOIUrl":"https://doi.org/10.5937/str2102026r","url":null,"abstract":"Unmanned aerial vehicles represent an indispensable segment in the range of weapons of both military and police units. The expansion in development of unmanned aerial vehicles for both commercial and military purposes has created a need for constant improvement of drones and anti-drone means. A wide range of possibilities opens up a wide range of uses for them. The paper presents the choice of an unmanned aerial vehicle as an important combat system for the needs of tactical units of the army and police. The complexity of the problem is conditioned by various tactical-technical and economic characteristics of unmanned aerial vehicles, it has conditioned the use of different methods of multicriteria decision making. A hybrid model of multicriteria decision making fuzzy AHP-VIKOR was used to select the unmanned aerial vehicle for the needs of tactical units. Criteria of importance for the selection of an unmanned aerial vehicle for the needs of tactical units have been defined on the basis of which the most optimal solution (unmanned aerial vehicle) has been selected. The criteria are defined on the basis of tactical-technical and economic characteristics of unmanned aerial vehicles. The calculation of the weight coefficients of the defined criteria was performed using the fuzzy AHP method, while the selection of the drone (the most favorable alternative) based on the defined criteria was performed using the VIKOR method. The obtained result represents the starting point for further research and implementation of unmanned aerial vehicles in tactical units of the army and police.","PeriodicalId":33842,"journal":{"name":"Scientific Technical Review","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71085481","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}
Aluminum alloys of 7xxx series have the highest strength among all aluminium alloys, but they are prone to the corrosion-induced damage. The retrogression and re-aging heat treatment (RRA) is a heat treatment process applied on the 7xxx series aluminum alloy in T6 temper condition to provide a significant improvement of the corrosion resistance with or without small loss in its strength. The paper presents the influence of RRA treatment on the electrical conductivity and mechanical properties of the aluminum EN AW 7049A-T6 alloy. The retrogression heat treatment was performed at various temperatures (from 180 C to 280 C) and times (from 3 min to 45 min), while re-aging was performed at 120 °C for 24 hours. It has been found that with increasing both temperature and time of retrogression, hardness and strength decrease but the toughness of the alloy increases in comparison to the initial T6 temper. Contrary to hardness values, electrical conductivity rises with an increase in holding time and temperature of retrogression.
{"title":"Influence of retrogression and re-aging treatment on mechanical properties of the alloy EN AW 7049A-T6","authors":"J. Marinković, L. Radović","doi":"10.5937/str2101008m","DOIUrl":"https://doi.org/10.5937/str2101008m","url":null,"abstract":"Aluminum alloys of 7xxx series have the highest strength among all aluminium alloys, but they are prone to the corrosion-induced damage. The retrogression and re-aging heat treatment (RRA) is a heat treatment process applied on the 7xxx series aluminum alloy in T6 temper condition to provide a significant improvement of the corrosion resistance with or without small loss in its strength. The paper presents the influence of RRA treatment on the electrical conductivity and mechanical properties of the aluminum EN AW 7049A-T6 alloy. The retrogression heat treatment was performed at various temperatures (from 180 C to 280 C) and times (from 3 min to 45 min), while re-aging was performed at 120 °C for 24 hours. It has been found that with increasing both temperature and time of retrogression, hardness and strength decrease but the toughness of the alloy increases in comparison to the initial T6 temper. Contrary to hardness values, electrical conductivity rises with an increase in holding time and temperature of retrogression.","PeriodicalId":33842,"journal":{"name":"Scientific Technical Review","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71084750","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 paper presents the selection of the most accurate and precise automatic rifle, as a significant weapon primarily for the realization of combat tasks of the army. The size of the image of the scattering of shots and its distance from the target determine the degree of accuracy and precision of the automatic rifle. These indicators determine the probability of hitting, which affects the efficiency of solving fire tasks with an automatic rifle. The complexity of the problem is due to the different tactical and technical characteristics of automatic rifles and different shooting results. The paper presents and describes the results of shooting automatic rifles of domestic production, as follows: AR 7.62 mm M70 AB2, AR M21 5.56 mm, MAR M17 6.5 mm. Using the AHP method, the calculation of the weight coefficients of the criteria was performed. Using the AHP method, an analysis of the accuracy and precision of automatic rifle shooting was performed and a conclusion was made about the rifle that has the best results depending on the shooting distance. The obtained results enable the definition of proposals for equipping the Serbian Armed Forces units with an adequate automatic rifle.
本文介绍了选择最精确、最精密的自动步枪，主要是为了实现军队的作战任务。射击散射图像的大小及其与目标的距离决定了自动步枪的精度和精度的高低。这些指标决定了命中概率，影响着自动步枪解决射击任务的效率。问题的复杂性是由于自动步枪不同的战术技术特点和不同的射击效果造成的。本文介绍了国产自动步枪的射击效果:ar7.62 mm M70 AB2, arm21 5.56 mm, marm17 6.5 mm。采用层次分析法计算各指标的权重系数。运用层次分析法对自动步枪射击精度和精度进行了分析，得出了随射击距离变化的最佳射击效果。所取得的结果使我们能够确定为塞族武装部队装备适当的自动步枪的建议。
{"title":"Analysis of accuracy and precision of shooting with home: Made automatic rifles using the AHP method","authors":"Marko Radovanović, A. Milic, A. Petrovski","doi":"10.5937/str2101030r","DOIUrl":"https://doi.org/10.5937/str2101030r","url":null,"abstract":"The paper presents the selection of the most accurate and precise automatic rifle, as a significant weapon primarily for the realization of combat tasks of the army. The size of the image of the scattering of shots and its distance from the target determine the degree of accuracy and precision of the automatic rifle. These indicators determine the probability of hitting, which affects the efficiency of solving fire tasks with an automatic rifle. The complexity of the problem is due to the different tactical and technical characteristics of automatic rifles and different shooting results. The paper presents and describes the results of shooting automatic rifles of domestic production, as follows: AR 7.62 mm M70 AB2, AR M21 5.56 mm, MAR M17 6.5 mm. Using the AHP method, the calculation of the weight coefficients of the criteria was performed. Using the AHP method, an analysis of the accuracy and precision of automatic rifle shooting was performed and a conclusion was made about the rifle that has the best results depending on the shooting distance. The obtained results enable the definition of proposals for equipping the Serbian Armed Forces units with an adequate automatic rifle.","PeriodicalId":33842,"journal":{"name":"Scientific Technical Review","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71085467","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}
Concept of an active protection system on combat vehicles with high-explosive fragmentation interceptor projectile is presented in this paper. Development process and characteristics of the active protection system are highly dependent on performance characteristics of an interceptor projectile. The interceptor projectile generating frontal spray of steel spherical fragments was considered. The research on design features of contemporary rocket-propelled anti-tank projectiles was done in order to define required capabilities of the projectile for active protection systems. Vulnerability of an anti-tank projectile was analyzed according to its dimensions and design of main subsystems. Representative models of different types of anti-tank projectiles were considered for vulnerability assessment. Results of minimal fragment number density and minimal impact velocity are presented and the most significant conclusions are made.
{"title":"Required capabilities of a high-explosive projectile for active protection systems","authors":"J. Bogdanov, Anas Chabane","doi":"10.5937/str2101019b","DOIUrl":"https://doi.org/10.5937/str2101019b","url":null,"abstract":"Concept of an active protection system on combat vehicles with high-explosive fragmentation interceptor projectile is presented in this paper. Development process and characteristics of the active protection system are highly dependent on performance characteristics of an interceptor projectile. The interceptor projectile generating frontal spray of steel spherical fragments was considered. The research on design features of contemporary rocket-propelled anti-tank projectiles was done in order to define required capabilities of the projectile for active protection systems. Vulnerability of an anti-tank projectile was analyzed according to its dimensions and design of main subsystems. Representative models of different types of anti-tank projectiles were considered for vulnerability assessment. Results of minimal fragment number density and minimal impact velocity are presented and the most significant conclusions are made.","PeriodicalId":33842,"journal":{"name":"Scientific Technical Review","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71084998","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}
S. Petronic, K. Čolić, Arko Jarić, N. Ćurčić, Z. Burzić, Svetozar Sofijanić
Gas rectification columns are a very important part of each onshore plant. Their sudden failures cause huge losses on a daily basis, while fluid leakage can be very dangerous to people and environment. For that reason, the proper design of the column is of huge importance, among the others safety factors as well. In this paper, the wall thickness measure is presented with the aim to calculate corrosion rate and remaining life of rectification columns. The minimum required column wall thickness was calculated according to the most commonly used international standard and the obtained difference was analyzed.
{"title":"Safety factors in wall thickness calculation of rectification columns","authors":"S. Petronic, K. Čolić, Arko Jarić, N. Ćurčić, Z. Burzić, Svetozar Sofijanić","doi":"10.5937/str2101003p","DOIUrl":"https://doi.org/10.5937/str2101003p","url":null,"abstract":"Gas rectification columns are a very important part of each onshore plant. Their sudden failures cause huge losses on a daily basis, while fluid leakage can be very dangerous to people and environment. For that reason, the proper design of the column is of huge importance, among the others safety factors as well. In this paper, the wall thickness measure is presented with the aim to calculate corrosion rate and remaining life of rectification columns. The minimum required column wall thickness was calculated according to the most commonly used international standard and the obtained difference was analyzed.","PeriodicalId":33842,"journal":{"name":"Scientific Technical Review","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71084633","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}
S. Prvulović, J. Tolmač, E. Desnica, M. Josimović, Ivana Bicok
In this paper the analysis and description of the operation of the Premix station for dosing the substrate into existing digesters whose location is in the system of the device for processing of liquid waste are described. Apart from the capacity and other entry parameters, the necessary diameter of the pipeline with the length of the section for supplying the devices of the PreMix system is calculated, as it is given in the appropriate tables, the connection of the existing equipment and digesters is presented. The appropriate dependence of the volume flow, the velocity of circulation and power at constant pressure as well as the dependence of the volume flow, pressure and power at constant velocity of circulation are presented by diagrams.
{"title":"The station for dosing the substratum into existing digesters: PreMix","authors":"S. Prvulović, J. Tolmač, E. Desnica, M. Josimović, Ivana Bicok","doi":"10.5937/str2101015p","DOIUrl":"https://doi.org/10.5937/str2101015p","url":null,"abstract":"In this paper the analysis and description of the operation of the Premix station for dosing the substrate into existing digesters whose location is in the system of the device for processing of liquid waste are described. Apart from the capacity and other entry parameters, the necessary diameter of the pipeline with the length of the section for supplying the devices of the PreMix system is calculated, as it is given in the appropriate tables, the connection of the existing equipment and digesters is presented. The appropriate dependence of the volume flow, the velocity of circulation and power at constant pressure as well as the dependence of the volume flow, pressure and power at constant velocity of circulation are presented by diagrams.","PeriodicalId":33842,"journal":{"name":"Scientific Technical Review","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71084922","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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