Serbian conservationists could learn a lot from the revitalization example of the Old city of Bern. Analyses of this example show that the method of revitalization and protection of listed, but abandoned and inhabited, buildings depends on its future use. Alone analyses of future purpose of built heritage cannot be used as a method for its revitalization. The use of new ideas based on historical importance of the protected building generates the building's structures. The approach of revitalization through the process of building structuring and adaptation to new purpose has been tested through different analyses. It was found that the future purpose of building cannot be determined only by defining the revitalization method, set by public body, but in this process the future owner of building should actively participate. The recommendations for transferring this methodology in solving Serbian built heritage problems are given.
{"title":"Methods for determination of revitalization potential of built heritage: Lessons learned on the city of Bern","authors":"G. Stanišić, Nadja Kurtović-Folić","doi":"10.5937/GRMK1501025S","DOIUrl":"https://doi.org/10.5937/GRMK1501025S","url":null,"abstract":"Serbian conservationists could learn a lot from the revitalization example of the Old city of Bern. Analyses of this example show that the method of revitalization and protection of listed, but abandoned and inhabited, buildings depends on its future use. Alone analyses of future purpose of built heritage cannot be used as a method for its revitalization. The use of new ideas based on historical importance of the protected building generates the building's structures. The approach of revitalization through the process of building structuring and adaptation to new purpose has been tested through different analyses. It was found that the future purpose of building cannot be determined only by defining the revitalization method, set by public body, but in this process the future owner of building should actively participate. The recommendations for transferring this methodology in solving Serbian built heritage problems are given.","PeriodicalId":40707,"journal":{"name":"Gradevnski Materijiali I Konstrukcije-Building Materials and Structures","volume":"58 1","pages":"25-57"},"PeriodicalIF":0.4,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71225259","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}
Drvo je jedan od najstarijih građevinskih materijala i pored kamena je dugi niz godina bio osnovni materijal za građenje. Njegove karakteristike omogućavaju visok stepen prefabrikacije, brzu montažu na terenu i trenutnu useljivost. Zbog velike požarne otpornosti u požaru ne gubi nosiva svojstva, odnosno mehaničke karakteristike ne menjaju se bitno prilikom visokih temperatura. Drvene konstrukcije su pet puta lakše od armiranobetonskih, pa mogu lakše preuzeti seizmičke sile i predstavljaju dobar izbor u trusnim područjima. Objekti izgrađeni od drveta imaju visoku energetsku efikasnost. Poslednjih decenija, drvo se sve više primenjuje u izgradnji modernih arhitektonskih građevina (npr. sportskih objekata, stambenih zgrada, mostova) zahvaljujući boljem poznavanju drveta kao materijala, primeni savremenih drvenih konstrukcija i upotrebi kvalitetnih spojnih sredstava. Konstruktivni elementi savremenih drvenih konstrukcija bazirani su prvenstveno na savremenim proizvodima od drveta kao što su lepljeno lamelirano i unakrsno lamelirano drvo.
{"title":"Cross laminated timber elements in contemporary timber structures of buildings: Application and design","authors":"Kozarić Ljiljana, Prokić Aleksandar, B. Miroslav","doi":"10.5937/GRMK1504051K","DOIUrl":"https://doi.org/10.5937/GRMK1504051K","url":null,"abstract":"Drvo je jedan od najstarijih građevinskih materijala i pored kamena je dugi niz godina bio osnovni materijal za građenje. Njegove karakteristike omogućavaju visok stepen prefabrikacije, brzu montažu na terenu i trenutnu useljivost. Zbog velike požarne otpornosti u požaru ne gubi nosiva svojstva, odnosno mehaničke karakteristike ne menjaju se bitno prilikom visokih temperatura. Drvene konstrukcije su pet puta lakše od armiranobetonskih, pa mogu lakše preuzeti seizmičke sile i predstavljaju dobar izbor u trusnim područjima. Objekti izgrađeni od drveta imaju visoku energetsku efikasnost. Poslednjih decenija, drvo se sve više primenjuje u izgradnji modernih arhitektonskih građevina (npr. sportskih objekata, stambenih zgrada, mostova) zahvaljujući boljem poznavanju drveta kao materijala, primeni savremenih drvenih konstrukcija i upotrebi kvalitetnih spojnih sredstava. Konstruktivni elementi savremenih drvenih konstrukcija bazirani su prvenstveno na savremenim proizvodima od drveta kao što su lepljeno lamelirano i unakrsno lamelirano drvo.","PeriodicalId":40707,"journal":{"name":"Gradevnski Materijiali I Konstrukcije-Building Materials and Structures","volume":"58 1","pages":"51-69"},"PeriodicalIF":0.4,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71224886","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}
Laminar composites are modern engineering materials widely used in the mechanical and civil engineering. In the paper, some recent advances in a numerical analysis of laminated composite and sandwich plates and shells of different shapes, with existing zones of partial delamination, are presented. The layered finite elements, based on the extended version of the Generalized Laminated Plate Theory of Reddy, are applied for the numerical solution of several structural problems. After the verification of the proposed model for intact structures using the existing data from the literature, the effects of the size and the position of embedded delamination zones on the structural response of laminated structures are investigated numerically by means of a variety of numerical applications.
{"title":"Application of layered finite elements in the numerical analysis of laminated composite and sandwich structures with delaminations","authors":"Djordje Vuksanović, M. Marjanović","doi":"10.5937/grmk1501059v","DOIUrl":"https://doi.org/10.5937/grmk1501059v","url":null,"abstract":"Laminar composites are modern engineering materials widely used in the mechanical and civil engineering. In the paper, some recent advances in a numerical analysis of laminated composite and sandwich plates and shells of different shapes, with existing zones of partial delamination, are presented. The layered finite elements, based on the extended version of the Generalized Laminated Plate Theory of Reddy, are applied for the numerical solution of several structural problems. After the verification of the proposed model for intact structures using the existing data from the literature, the effects of the size and the position of embedded delamination zones on the structural response of laminated structures are investigated numerically by means of a variety of numerical applications.","PeriodicalId":40707,"journal":{"name":"Gradevnski Materijiali I Konstrukcije-Building Materials and Structures","volume":"58 1","pages":"59-76"},"PeriodicalIF":0.4,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71225270","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 deals with methodology developed and presented for analyzing the damage on structures exposed to accidental and seismic actions. The procedure is based on non-linear numerical analysis, taking into account the principles of Performance-Based Seismic Design (PBSD). The stiffness matrix of the effects of vertical action is used as the initial stiffness matrix in non-linear analysis which simulates the collapse of individual ground-floor columns, forming thereby a number of possible scenarios. By the end of the analysis that simulates the collapse of individual columns, the stiffness matrix is used as the initial stiffness matrix for Non-linear Static Pushover Analysis (NSPA) of bi-directional seismic action (X and Y directions). Target displacement analyses were conducted using the Capacity Spectrum Method (CSM). The structure's conditions/state was assessed based on the calculated global and inter-storey drifts and the damage coefficient developed. The damage level to the building was established using an integrated approach based on global and inter-storey drifts, so that, depending on the level of displacements for which the drifts are identified, a more reliable answer can be obtained. Applying the damage coefficient, a prompt, reliable and accurate indication can be obtained on the damage level to the entire structure in the capacitive domain, from elastic and non-linear to collapse state.
{"title":"Performance analysis of damaged buildings applying scenario of related non-linear analyses and damage coefficient","authors":"M. Ćosić, R. Folić","doi":"10.5937/GRMK1503003C","DOIUrl":"https://doi.org/10.5937/GRMK1503003C","url":null,"abstract":"The paper deals with methodology developed and presented for analyzing the damage on structures exposed to accidental and seismic actions. The procedure is based on non-linear numerical analysis, taking into account the principles of Performance-Based Seismic Design (PBSD). The stiffness matrix of the effects of vertical action is used as the initial stiffness matrix in non-linear analysis which simulates the collapse of individual ground-floor columns, forming thereby a number of possible scenarios. By the end of the analysis that simulates the collapse of individual columns, the stiffness matrix is used as the initial stiffness matrix for Non-linear Static Pushover Analysis (NSPA) of bi-directional seismic action (X and Y directions). Target displacement analyses were conducted using the Capacity Spectrum Method (CSM). The structure's conditions/state was assessed based on the calculated global and inter-storey drifts and the damage coefficient developed. The damage level to the building was established using an integrated approach based on global and inter-storey drifts, so that, depending on the level of displacements for which the drifts are identified, a more reliable answer can be obtained. Applying the damage coefficient, a prompt, reliable and accurate indication can be obtained on the damage level to the entire structure in the capacitive domain, from elastic and non-linear to collapse state.","PeriodicalId":40707,"journal":{"name":"Gradevnski Materijiali I Konstrukcije-Building Materials and Structures","volume":"58 1","pages":"3-27"},"PeriodicalIF":0.4,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71225279","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}
Cement based materials in the agricultural and other industrial structures are exposed to acid attack. That is the reason why the service life of structure depends on the durability of mortar or concrete elements in aggressive environment. Resistance to corrosion caused by sulphate, nitrate, carbamide, lactic acid and acetic acid was presented. Optical and scanning electron microscopy (SEM) was used to examine the effect of aggressive solutions on the microstructure and mechanical properties of mortar. The chemical resistance of mortar prisms and two types of concrete were tested according to the Koch-Steinegger method. As the condition for resistance in aggressive solution is that flexural strength of mortar prisms is no less than 70 % compared to referent prisms cured in water it can be concluded that mortar and concrete made with CEM III/B in this investigation are resistant to all treated acids.
{"title":"Resistance of CEM III/B based materials to acid attack","authors":"K. Jankovic, D. Bojović, M. Stojanović, L. Lončar","doi":"10.5937/GRMK1402029J","DOIUrl":"https://doi.org/10.5937/GRMK1402029J","url":null,"abstract":"Cement based materials in the agricultural and other industrial structures are exposed to acid attack. That is the reason why the service life of structure depends on the durability of mortar or concrete elements in aggressive environment. Resistance to corrosion caused by sulphate, nitrate, carbamide, lactic acid and acetic acid was presented. Optical and scanning electron microscopy (SEM) was used to examine the effect of aggressive solutions on the microstructure and mechanical properties of mortar. The chemical resistance of mortar prisms and two types of concrete were tested according to the Koch-Steinegger method. As the condition for resistance in aggressive solution is that flexural strength of mortar prisms is no less than 70 % compared to referent prisms cured in water it can be concluded that mortar and concrete made with CEM III/B in this investigation are resistant to all treated acids.","PeriodicalId":40707,"journal":{"name":"Gradevnski Materijiali I Konstrukcije-Building Materials and Structures","volume":"57 1","pages":"29-37"},"PeriodicalIF":0.4,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71225010","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}
Creep test involves deformation of material with time under a constant stress. Hence, for proper conducting of the creep test it is highly important to maintain, i.e. constant control the stress applied to a specimen. Namely, impact of the compression on the extent of deformation is distinctively non-linear; therefore the stress level or eventual variations of stress over time largely affect the increment of time-dependent components of deformation. Therefore, it is necessary to ensure that variations of stress are kept within limits of ±1% during the creep test the duration of which sometimes may last for several years. This paper presents structure of the dead-weight creep apparatus for maintaining constant stress over long time interval (day, week or year) with a capacity of 750kN and 1500kN, as well as for measuring of force and deformations at creep test. The creep tests have been conducted on marl specimens in duration of up to one year. The creep test results are presented for the uniaxially compressed prismatic specimens of dimensions 15x15x40cm and biaxially compressed plate models of dimensions 60x60x10cm, with circular opening at centre.
{"title":"Testing of creep phenomena on soft rock","authors":"Z. Tomanović","doi":"10.5937/GRMK1403021T","DOIUrl":"https://doi.org/10.5937/GRMK1403021T","url":null,"abstract":"Creep test involves deformation of material with time under a constant stress. Hence, for proper conducting of the creep test it is highly important to maintain, i.e. constant control the stress applied to a specimen. Namely, impact of the compression on the extent of deformation is distinctively non-linear; therefore the stress level or eventual variations of stress over time largely affect the increment of time-dependent components of deformation. Therefore, it is necessary to ensure that variations of stress are kept within limits of ±1% during the creep test the duration of which sometimes may last for several years. This paper presents structure of the dead-weight creep apparatus for maintaining constant stress over long time interval (day, week or year) with a capacity of 750kN and 1500kN, as well as for measuring of force and deformations at creep test. The creep tests have been conducted on marl specimens in duration of up to one year. The creep test results are presented for the uniaxially compressed prismatic specimens of dimensions 15x15x40cm and biaxially compressed plate models of dimensions 60x60x10cm, with circular opening at centre.","PeriodicalId":40707,"journal":{"name":"Gradevnski Materijiali I Konstrukcije-Building Materials and Structures","volume":"57 1","pages":"21-41"},"PeriodicalIF":0.4,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71225087","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}
This paper statistically investigates the testing results of compressive strength and density of control concrete specimens tested in the Laboratory for materials, Faculty of Civil Engineering, University of Belgrade, during 2012. The total number of 4420 concrete specimens were tested, which were sampled on different locations - either on concrete production site (concrete plant), or concrete placement location (construction site). To be exact, these samples were made of concrete which was produced on 15 concrete plants, i.e. placed in at 50 different reinforced concrete structures, built during 2012 by 22 different contractors. It is a known fact that the achieved values of concrete compressive strength are very important, both for quality and durability assessment of concrete inside the structural elements, as well as for calculation of their load-bearing capacity limit. Together with the compressive strength testing results, the data concerning requested (designed) concrete class, matching between the designed and the achieved concrete quality, concrete density values and frequency of execution of concrete works during 2012 were analyzed.
{"title":"Statistical analysis of concrete quality testing results","authors":"D. Jevtić, D. Zakić, A. Savić, Aleksandar Radević","doi":"10.5937/GRMK1401045J","DOIUrl":"https://doi.org/10.5937/GRMK1401045J","url":null,"abstract":"This paper statistically investigates the testing results of compressive strength and density of control concrete specimens tested in the Laboratory for materials, Faculty of Civil Engineering, University of Belgrade, during 2012. The total number of 4420 concrete specimens were tested, which were sampled on different locations - either on concrete production site (concrete plant), or concrete placement location (construction site). To be exact, these samples were made of concrete which was produced on 15 concrete plants, i.e. placed in at 50 different reinforced concrete structures, built during 2012 by 22 different contractors. It is a known fact that the achieved values of concrete compressive strength are very important, both for quality and durability assessment of concrete inside the structural elements, as well as for calculation of their load-bearing capacity limit. Together with the compressive strength testing results, the data concerning requested (designed) concrete class, matching between the designed and the achieved concrete quality, concrete density values and frequency of execution of concrete works during 2012 were analyzed.","PeriodicalId":40707,"journal":{"name":"Gradevnski Materijiali I Konstrukcije-Building Materials and Structures","volume":"57 1","pages":"45-52"},"PeriodicalIF":0.4,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71224938","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}
Von Karman theory has been used for the description of the post-buckling behaviour of a thin- walled panel with imperfections and residual stresses. Using Hamilton's principle in incremental form the problem of free vibration has been established. Examples of buckling of a column, frame and a slender web loaded in compression emphasizing different types of support are presented. An influence of the mode of the geometrical imperfection is shown and an approximate solution taking into account the residual stresses is found. Theoretical and numerical results are compared with the results from a laboratory experiment. .
{"title":"Stability and vibration in civil engineering","authors":"J. Ravinger","doi":"10.5937/GRMK1402003R","DOIUrl":"https://doi.org/10.5937/GRMK1402003R","url":null,"abstract":"Von Karman theory has been used for the description of the post-buckling behaviour of a thin- walled panel with imperfections and residual stresses. Using Hamilton's principle in incremental form the problem of free vibration has been established. Examples of buckling of a column, frame and a slender web loaded in compression emphasizing different types of support are presented. An influence of the mode of the geometrical imperfection is shown and an approximate solution taking into account the residual stresses is found. Theoretical and numerical results are compared with the results from a laboratory experiment. .","PeriodicalId":40707,"journal":{"name":"Gradevnski Materijiali I Konstrukcije-Building Materials and Structures","volume":"57 1","pages":"3-17"},"PeriodicalIF":0.4,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71224973","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}
Bridge flutter phenomenon presents an important criterion of instability, which should be considered in the bridge design phase. This paper presents different bridge flutter methods which can be used to solve the flutter problem. Most commonly used frequency-domain approach is based on the formulation of aero elastic forces with frequency dependent coefficients called flutter derivatives. The critical wind speed, as the main critical condition for the onset of flutter is obtained based on these aero elastic forces. Aero elastic forces can be also expressed in the time-domain, using so-called indicial functions. These functions are usually determined from the corresponding flutter derivatives. In situations when fluid-memory effects tend to become small the quasi-steady theory can be used as an approximation of aero elastic forces. A numerical example related to the typical bridge cross-section follows presented approaches. .
{"title":"Frequency- and time-domain methods related to flutter instability problem","authors":"A. Šarkić, Miloš Jočković, S. Brčić","doi":"10.5937/GRMK1402039S","DOIUrl":"https://doi.org/10.5937/GRMK1402039S","url":null,"abstract":"Bridge flutter phenomenon presents an important criterion of instability, which should be considered in the bridge design phase. This paper presents different bridge flutter methods which can be used to solve the flutter problem. Most commonly used frequency-domain approach is based on the formulation of aero elastic forces with frequency dependent coefficients called flutter derivatives. The critical wind speed, as the main critical condition for the onset of flutter is obtained based on these aero elastic forces. Aero elastic forces can be also expressed in the time-domain, using so-called indicial functions. These functions are usually determined from the corresponding flutter derivatives. In situations when fluid-memory effects tend to become small the quasi-steady theory can be used as an approximation of aero elastic forces. A numerical example related to the typical bridge cross-section follows presented approaches. .","PeriodicalId":40707,"journal":{"name":"Gradevnski Materijiali I Konstrukcije-Building Materials and Structures","volume":"57 1","pages":"39-56"},"PeriodicalIF":0.4,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71225026","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 purpose of the paper is to share the experience in application of Eurocode 8. Following the existing framework of the European standard two engineering development of two specific topics are proposed. First deals with modelling the seismic action aiming to take into account spatial variability of the seismic action. It is proven that the inclusion of rotational components may influence the action effects and the results provide unsafe design. Evaluation is carried out through response spectrum method. The second topic studies the use of performance based seismic design as a tool to prove the need for seismic strengthening and verification of the benefit. Both target and actual capacity spectra are compared to make assessment of the lateral resistance of existing and strengthened structure. Insufficient elastic stiffness and insufficient yield strength are considered as the most typical situations frequently met in the design practice and which can be settled by seismic strengthening. Discussions and conclusions concerning the philosophy of the assessment procedure are presented.
{"title":"Eurocode 8: Use of advantageous formulations for improved and safe design","authors":"Z. Bonev, Stanislav Dospevski","doi":"10.5937/GRMK1403003B","DOIUrl":"https://doi.org/10.5937/GRMK1403003B","url":null,"abstract":"The purpose of the paper is to share the experience in application of Eurocode 8. Following the existing framework of the European standard two engineering development of two specific topics are proposed. First deals with modelling the seismic action aiming to take into account spatial variability of the seismic action. It is proven that the inclusion of rotational components may influence the action effects and the results provide unsafe design. Evaluation is carried out through response spectrum method. The second topic studies the use of performance based seismic design as a tool to prove the need for seismic strengthening and verification of the benefit. Both target and actual capacity spectra are compared to make assessment of the lateral resistance of existing and strengthened structure. Insufficient elastic stiffness and insufficient yield strength are considered as the most typical situations frequently met in the design practice and which can be settled by seismic strengthening. Discussions and conclusions concerning the philosophy of the assessment procedure are presented.","PeriodicalId":40707,"journal":{"name":"Gradevnski Materijiali I Konstrukcije-Building Materials and Structures","volume":"57 1","pages":"3-20"},"PeriodicalIF":0.4,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71225076","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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