Pub Date : 2019-04-05DOI: 10.24423/ENGTRANS.1009.20190405
T. Matsuo, Daisuke Hatanaka
A monitoring system for fatigue crack propagation was developed using a non-contact acoustic emission (AE) monitoring system. The AE signals generated during the plane bending fatigue test were first monitored. The AE generation rate increased after approximately 0.5 of the fatigue life ratio. The maximum amplitude of the AE signals increased with a tendency similar to that of the crack propagation. The sensor sensitivities for the flat and arced surfaces were then compared. The sensitivity improved when the specimen surface was flat. The bar specimen with plane surfaces was used for the AE monitoring of the rotary bending fatigue test. From 0.715 of the fatigue life ratio, the AE generation rate increased after crack generation. The AE signals were detected at an earlier stage of the fatigue life in the flat surface specimen compared with the arc surface specimen during the rotary bending fatigue test. The detection of fatigue cracks in the rotary component at an early stage was possible using a non-contact AE monitoring system.
{"title":"Development of Non-Contact Fatigue Crack Propagation Monitoring Method Using Air-Coupled Acoustic Emission System","authors":"T. Matsuo, Daisuke Hatanaka","doi":"10.24423/ENGTRANS.1009.20190405","DOIUrl":"https://doi.org/10.24423/ENGTRANS.1009.20190405","url":null,"abstract":"A monitoring system for fatigue crack propagation was developed using a non-contact acoustic emission (AE) monitoring system. The AE signals generated during the plane bending fatigue test were first monitored. The AE generation rate increased after approximately 0.5 of the fatigue life ratio. The maximum amplitude of the AE signals increased with a tendency similar to that of the crack propagation. The sensor sensitivities for the flat and arced surfaces were then compared. The sensitivity improved when the specimen surface was flat. The bar specimen with plane surfaces was used for the AE monitoring of the rotary bending fatigue test. From 0.715 of the fatigue life ratio, the AE generation rate increased after crack generation. The AE signals were detected at an earlier stage of the fatigue life in the flat surface specimen compared with the arc surface specimen during the rotary bending fatigue test. The detection of fatigue cracks in the rotary component at an early stage was possible using a non-contact AE monitoring system.","PeriodicalId":38552,"journal":{"name":"Engineering Transactions","volume":"67 1","pages":"185-198"},"PeriodicalIF":0.0,"publicationDate":"2019-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47278471","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 : 2019-04-04DOI: 10.24423/ENGTRANS.979.20190404
I. Wstawska, K. Magnucki, P. Kȩdzia
The paper deals with a proposition of obtaining an analytical solution for a beam on elastic foundation. The main objective of presented work was stability analysis of the axially compressed beam. The analytical model was proposed. Shape function for inhomogeneous properties of the foundation was assumed. The Galerkin method was used to calculate the values of critical forces. Main conditions have been defined. The critical loads as a function of geometric and mechanical properties of the beam as well as inhomogeneous properties of the elastic foundation have been calculated.
{"title":"Approximate Estimation of Stability of Homogeneous Beam on Elastic Foundation","authors":"I. Wstawska, K. Magnucki, P. Kȩdzia","doi":"10.24423/ENGTRANS.979.20190404","DOIUrl":"https://doi.org/10.24423/ENGTRANS.979.20190404","url":null,"abstract":"The paper deals with a proposition of obtaining an analytical solution for a beam on elastic foundation. The main objective of presented work was stability analysis of the axially compressed beam. The analytical model was proposed. Shape function for inhomogeneous properties of the foundation was assumed. The Galerkin method was used to calculate the values of critical forces. Main conditions have been defined. The critical loads as a function of geometric and mechanical properties of the beam as well as inhomogeneous properties of the elastic foundation have been calculated.","PeriodicalId":38552,"journal":{"name":"Engineering Transactions","volume":"67 1","pages":"429-440"},"PeriodicalIF":0.0,"publicationDate":"2019-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47806614","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 : 2019-03-07DOI: 10.24423/ENGTRANS.909.20190308
V. Ri̇zov
The present paper investigates lengthwise crack behaviour in three-axial inhomogeneous non-linear elastic cantilever beams, i.e., beams which exhibit inhomogeneous material properties along the width, height and length. The non-linear mechanical behaviour of the inhomogeneous material is described by the Ramberg-Osgood equation assuming that the modulus of elasticity varies linearly along the width, height and length of beams. A solution to the strain energy release rate is derived by considering the balance of the energy. The results obtained in the present paper indicate that the three-axial inhomogeneous material properties have a significant influence on the strain energy release rate in non-linear elastic beams.
{"title":"Effects of Three-Axial Material Inhomogeneity on Lengthwise Cracks in Non-Linear Elastic Beams","authors":"V. Ri̇zov","doi":"10.24423/ENGTRANS.909.20190308","DOIUrl":"https://doi.org/10.24423/ENGTRANS.909.20190308","url":null,"abstract":"The present paper investigates lengthwise crack behaviour in three-axial inhomogeneous non-linear elastic cantilever beams, i.e., beams which exhibit inhomogeneous material properties along the width, height and length. The non-linear mechanical behaviour of the inhomogeneous material is described by the Ramberg-Osgood equation assuming that the modulus \u0000of elasticity varies linearly along the width, height and length of beams. A solution to the strain energy release rate is derived by considering the balance of the energy. The results obtained in the present paper indicate that the three-axial inhomogeneous material properties have a significant influence on the strain energy release rate in non-linear elastic beams.","PeriodicalId":38552,"journal":{"name":"Engineering Transactions","volume":"67 1","pages":"35-54"},"PeriodicalIF":0.0,"publicationDate":"2019-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41749484","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 : 2019-03-07DOI: 10.24423/ENGTRANS.955.20190214
I. Y. Seini
A numerical approach has been adopted to investigate the steady chemically mixed convection boundary layer flow from the right face of a vertical plate of finite thickness. Cold fluid flowing over the right face of the plate contains a heat generation that decays exponentially with a dimensionless distance from the surface. The left face of the plate is in contact with a hot flowing fluid. The heating process on that side is characterized by a convective boundary condition that takes into account the conduction resistance of the plate as well as a possible contact resistance between the hot fluid and the left face of the plate. Using a pseudo similarity approach, the governing equations for the mixed convective flow over the right face of the plate are transformed into a set of coupled ordinary differential equations which give local similarity solutions. The effects of local Grashof numbers (defined to represent a mixed convection parameter), Prandtl number, and the internal heat generation parameter on the velocity, temperature and concentration profiles are illustrated and interpreted in physical terms.
{"title":"HEAT AND MASS TRANSFER FROM A CONVECTIVELY HEATED VERTICAL SURFACE WITH CHEMICAL REACTION AND INTERNAL HEAT GENERATION","authors":"I. Y. Seini","doi":"10.24423/ENGTRANS.955.20190214","DOIUrl":"https://doi.org/10.24423/ENGTRANS.955.20190214","url":null,"abstract":"A numerical approach has been adopted to investigate the steady chemically mixed convection boundary layer flow from the right face of a vertical plate of finite thickness. Cold fluid flowing over the right face of the plate contains a heat generation that decays exponentially with a dimensionless distance from the surface. The left face of the plate is in contact with a hot flowing fluid. The heating process on that side is characterized by a convective boundary condition that takes into account the conduction resistance of the plate as well as a possible contact resistance between the hot fluid and the left face of the plate. Using a pseudo similarity approach, the governing equations for the mixed convective flow over the right face of the plate are transformed into a set of coupled ordinary differential equations which give local similarity solutions. The effects of local Grashof numbers (defined to represent a mixed convection parameter), Prandtl number, and the internal heat generation parameter on the velocity, temperature and concentration profiles are illustrated and interpreted in physical terms.","PeriodicalId":38552,"journal":{"name":"Engineering Transactions","volume":"67 1","pages":"101-118"},"PeriodicalIF":0.0,"publicationDate":"2019-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43162106","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 : 2019-03-07DOI: 10.24423/ENGTRANS.820.20190308
M. Bhuvaneswari, S. Eswaramoorthi, S. Sivasankaran, A. Hussein
In this paper, we investigate the Dufour and Soret effects on MHD mixed convection of a chemically reacting fluid over a stretching surface in a porous medium with convective boundary condition. The similarity transformation is used to reduce the governing non-linear partial differential equations into an ordinary differential equations. Then, they are solved analytically by using homotopy analysis method (HAM) and are solved numerically by Runge-Kutta fourth order method. The analytical and numerical results for the velocity, temperature, concentration, skin friction, Nusselt number and Sherwood number are discussed.
{"title":"Cross-diffusion Effects on MHD Mixed Convection over a Stretching Surface in a Porous Medium with Chemical Reaction and Convective Condition","authors":"M. Bhuvaneswari, S. Eswaramoorthi, S. Sivasankaran, A. Hussein","doi":"10.24423/ENGTRANS.820.20190308","DOIUrl":"https://doi.org/10.24423/ENGTRANS.820.20190308","url":null,"abstract":"In this paper, we investigate the Dufour and Soret effects on MHD mixed convection of a chemically reacting fluid over a stretching surface in a porous medium with convective boundary condition. The similarity transformation is used to reduce the governing non-linear partial differential equations into an ordinary differential equations. Then, they are solved analytically by using homotopy analysis method (HAM) and are solved numerically by Runge-Kutta fourth order method. The analytical and numerical results for the velocity, temperature, concentration, skin friction, Nusselt number and Sherwood number are discussed.","PeriodicalId":38552,"journal":{"name":"Engineering Transactions","volume":"67 1","pages":"3-19"},"PeriodicalIF":0.0,"publicationDate":"2019-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49159291","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 : 2019-03-01DOI: 10.24423/ENGTRANS.983.20190301
Paweł Bajerski, R. Pęcherski, D. Chudy
Virtual additive manufacturing (AM) is a one of the new directions of research that is necessary to improve AM technology. Abaqus/SIMULIA software allows to simulate the whole process using user subroutines to expand solver capabilities. Two of the most important subroutines are UepActivationVol and UMATHT. The UepActivationVol is related to an activation of elements in accordance with the defined path of the process. The second one the UMATHT is used to implement and combine thermal and crystallization process [2]. The presented investigations describe the dual crystallization kinetics model for considered high temperature thermoplastic material Polyetheretherketone (PEEK). Furthermore, it is shown how to analyse the overall process with use of Abaqus/SIMULIA software. The innovation of the presented approach lies in the proper interpreting of the G-Code from Computeraided manufacturing software (CAM), which is an input for the real machines dedicated to AM. The path (coordinates of discrete points) and time of particular steps of the manufacturing process are extracted from the G-Code and are included as input parameters in the simulation code. The discretized part is simplification of the Computer-aided design (CAD) geometry. The final results show the effect implemented in user subroutines. Additionally, Differential Scanning Calorimetry (DSC) test results are presented in order to calculate crystallization and melting parameters. The presented work is the basis of the following investigations covering prediction of residual stresses, volumetric shrinkage and deformations.
{"title":"Virtual Additive Manufacturing Based on Semicrystalline Polymer Polyetheretherketone (PEEK)","authors":"Paweł Bajerski, R. Pęcherski, D. Chudy","doi":"10.24423/ENGTRANS.983.20190301","DOIUrl":"https://doi.org/10.24423/ENGTRANS.983.20190301","url":null,"abstract":"Virtual additive manufacturing (AM) is a one of the new directions of research that is necessary to improve AM technology. Abaqus/SIMULIA software allows to simulate the whole process using user subroutines to expand solver capabilities. Two of the most important subroutines are UepActivationVol and UMATHT. The UepActivationVol is related to an activation of elements in accordance with the defined path of the process. The second one the UMATHT is used to implement and combine thermal and crystallization process [2]. \u0000 \u0000The presented investigations describe the dual crystallization kinetics model for considered high temperature thermoplastic material Polyetheretherketone (PEEK). Furthermore, it is shown how to analyse the overall process with use of Abaqus/SIMULIA software. The innovation of the presented approach lies in the proper interpreting of the G-Code from Computeraided manufacturing software (CAM), which is an input for the real machines dedicated to AM. The path (coordinates of discrete points) and time of particular steps of the manufacturing process are extracted from the G-Code and are included as input parameters in the simulation code. The discretized part is simplification of the Computer-aided design (CAD) geometry. The final results show the effect implemented in user subroutines. Additionally, Differential Scanning Calorimetry (DSC) test results are presented in order to calculate crystallization and melting parameters. \u0000 \u0000The presented work is the basis of the following investigations covering prediction of residual stresses, volumetric shrinkage and deformations.","PeriodicalId":38552,"journal":{"name":"Engineering Transactions","volume":"67 1","pages":"157-165"},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44324613","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 : 2019-02-22DOI: 10.24423/ENGTRANS.982.20190222
R. Grzejda
Modelling and calculations of unsymmetrical multi-bolted connections treated as a system for different bolt models and contact layer models between the joined parts are presented. The modelling refers to preloaded and externally loaded connections. The systemic models of the connection for two substitute models of bolts are shown. Between the joined parts two types of the Winkler model of a contact layer are taken into consideration. Calculations were made for an exemplary unsymmetrical connection. Its models were preloaded and externally loaded with normal forces. As a result of the calculations, distributions of normal contact pressure at the interface of the parts joined in the connection are shown.
{"title":"Study of the Distribution of Normal Contact Pressure Between Parts Joined in a Multi-Bolted System under Operational Loads","authors":"R. Grzejda","doi":"10.24423/ENGTRANS.982.20190222","DOIUrl":"https://doi.org/10.24423/ENGTRANS.982.20190222","url":null,"abstract":"Modelling and calculations of unsymmetrical multi-bolted connections treated as a system for different bolt models and contact layer models between the joined parts are presented. The modelling refers to preloaded and externally loaded connections. The systemic models of the connection for two substitute models of bolts are shown. Between the joined parts two types of the Winkler model of a contact layer are taken into consideration. Calculations were made for an exemplary unsymmetrical connection. Its models were preloaded and externally loaded with normal forces. As a result of the calculations, distributions of normal contact pressure at the interface of the parts joined in the connection are shown.","PeriodicalId":38552,"journal":{"name":"Engineering Transactions","volume":"67 1","pages":"147-155"},"PeriodicalIF":0.0,"publicationDate":"2019-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43727395","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 : 2019-02-14DOI: 10.24423/ENGTRANS.910.20190214
Harendra Singh, Devendra Kumar, Jagdev Singh, C. S. Singh
The key purpose of the present work is to introduce a numerical algorithm for the solution of the fractional Klein-Gordon equation (FKGE). The numerical algorithm is based on the applications of the operational matrices of the Legendre scaling functions. The main advantage of the numerical algorithm is that it reduces the FKGE into Sylvester form of algebraic equations which significantly simplify the problem. Numerical results derived by using suggested numerical scheme are compared with the exact solution. The results show that the suggested algorithm is very user friendly for solving FKGE and accurate.
{"title":"A Reliable Numerical Algorithm for the Fractional Klein-Gordon Equation","authors":"Harendra Singh, Devendra Kumar, Jagdev Singh, C. S. Singh","doi":"10.24423/ENGTRANS.910.20190214","DOIUrl":"https://doi.org/10.24423/ENGTRANS.910.20190214","url":null,"abstract":"The key purpose of the present work is to introduce a numerical algorithm for the solution of the fractional Klein-Gordon equation (FKGE). The numerical algorithm is based on the applications of the operational matrices of the Legendre scaling functions. The main advantage of the numerical algorithm is that it reduces the FKGE into Sylvester form of algebraic equations \u0000which significantly simplify the problem. Numerical results derived by using suggested numerical scheme are compared with the exact solution. The results show that the suggested algorithm is very user friendly for solving FKGE and accurate.","PeriodicalId":38552,"journal":{"name":"Engineering Transactions","volume":"67 1","pages":"21-34"},"PeriodicalIF":0.0,"publicationDate":"2019-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45184273","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 : 2019-02-14DOI: 10.24423/ENGTRANS.944.20190214
K. Fischer, A. Stolz, C. Roller
Besides the primary threats of a blast loading scenario, flying fragments from nonstructural elements could be a further threat to exposed humans. Point fixed corrugated metal sheets are often applied as facade elements. This paper focuses on the analysis of the dynamic bearing resistance and related pull-out behaviour of such elements. In a first step, the dynamic bearing capacity is investigated by an experimental study. Different sheet thicknesses and dimensions are examined for different loading levels using shock tube experiments. Based on the experimental results an engineering model is applied to predict the overall bearing capacity of the investigated corrugated metal sheet elements using mathematical optimisation methods. In a second step, the comparison to an analytical approach to quantify the prognostic capacity of the theoretical assessment method is addressed. Obtained results enable fast and effective quantification of expected damage effects and can be integrated into an overall risk and resilience analysis scheme.
{"title":"Experimental and Analytical Investigation of Point Fixed Corrugated Metal Sheets Subjected to Blast Loading","authors":"K. Fischer, A. Stolz, C. Roller","doi":"10.24423/ENGTRANS.944.20190214","DOIUrl":"https://doi.org/10.24423/ENGTRANS.944.20190214","url":null,"abstract":"Besides the primary threats of a blast loading scenario, flying fragments from nonstructural elements could be a further threat to exposed humans. Point fixed corrugated metal sheets are often applied as facade elements. This paper focuses on the analysis of the dynamic bearing resistance and related pull-out behaviour of such elements. \u0000 \u0000In a first step, the dynamic bearing capacity is investigated by an experimental study. Different sheet thicknesses and dimensions are examined for different loading levels using shock tube experiments. Based on the experimental results an engineering model is applied to predict the overall bearing capacity of the investigated corrugated metal sheet elements using mathematical optimisation methods. \u0000 \u0000In a second step, the comparison to an analytical approach to quantify the prognostic capacity of the theoretical assessment method is addressed. Obtained results enable fast and effective quantification of expected damage effects and can be integrated into an overall risk and resilience analysis scheme.","PeriodicalId":38552,"journal":{"name":"Engineering Transactions","volume":"67 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42464752","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 : 2019-02-14DOI: 10.24423/ENGTRANS.941.20190124
M. Pająk, J. Janiszewski, L. Kruszka
The behavior of concrete reinforced with the fibers obtained from the end-of-life tires under high compressive strain rates was the scope of this research. The laboratory investigations were performed using the Hopkinson Pressure Bar with a diameter of 40 mm. The waste fibers with untypical geometrical parameters were applied to concrete with a dosage of 30 kg/m3. The pronounced increase of compressive strength of the RSFRC, when subjected to high strain rates, was observed. The strain rate sensitivity of the RSFRC expressed by DIF was comparable to the other results presented in the literature.
{"title":"Behavior of Concrete Reinforced with Fibers from End-of-Life Tires Under High Compressive Strain Rates","authors":"M. Pająk, J. Janiszewski, L. Kruszka","doi":"10.24423/ENGTRANS.941.20190124","DOIUrl":"https://doi.org/10.24423/ENGTRANS.941.20190124","url":null,"abstract":"The behavior of concrete reinforced with the fibers obtained from the end-of-life tires under high compressive strain rates was the scope of this research. The laboratory investigations were performed using the Hopkinson Pressure Bar with a diameter of 40 mm. The waste fibers with untypical geometrical parameters were applied to concrete with a dosage of 30 kg/m3. The pronounced increase of compressive strength of the RSFRC, when subjected to high strain rates, was observed. The strain rate sensitivity of the RSFRC expressed by DIF was comparable to the other results presented in the literature.","PeriodicalId":38552,"journal":{"name":"Engineering Transactions","volume":"67 1","pages":"119-131"},"PeriodicalIF":0.0,"publicationDate":"2019-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48318286","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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