This paper presents the assessment of masonry wall defects in residential buildings in Lithuania. The created model is based on a multi-attribute evaluation of wall defects in residential buildings in Lithuania, the determination of their optimality criterion values calculated according to Laplace’o rule. The developed defect assessment algorithm has advantages to be used by repair contractors and people or companies performing building maintenance. First, the model allows planning the course of repair works properly. When carrying out repair work in a building with recurring defects that mainly occur at the building site, proper workflow and its planning are essential. The proposed model could be applied further to a building owner to select the most damaged walls. A background and a description of the proposed model are provided, and several key findings from the data analyses are presented.
{"title":"ASSESSMENT OF DEFECTS IN MASONRY WALLS FOR THE RESIDENTIAL BUILDINGS IN LITHUANIA","authors":"Lukas Gritėnas, J. Tamošaitienė","doi":"10.3846/est.2021.18457","DOIUrl":"https://doi.org/10.3846/est.2021.18457","url":null,"abstract":"This paper presents the assessment of masonry wall defects in residential buildings in Lithuania. The created model is based on a multi-attribute evaluation of wall defects in residential buildings in Lithuania, the determination of their optimality criterion values calculated according to Laplace’o rule. The developed defect assessment algorithm has advantages to be used by repair contractors and people or companies performing building maintenance. First, the model allows planning the course of repair works properly. When carrying out repair work in a building with recurring defects that mainly occur at the building site, proper workflow and its planning are essential. The proposed model could be applied further to a building owner to select the most damaged walls. A background and a description of the proposed model are provided, and several key findings from the data analyses are presented.","PeriodicalId":11839,"journal":{"name":"Engineering Structures and Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47048127","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}
Cable-stayed bridges are known as one of the most effective and graceful forms of bridges. The main problem in the design of cable-stayed steel bridges is their deformability, especially under asymmetrical loads. Stabilization of the initial form of cable-stayed bridges can be achieved by selecting the appropriate cross-sectional area of the cables and their pre-stressing, as well as by increasing the cross-sectional height of the stiffness beam. However, a greater effect can be achieved by applying new forms of such bridges. Solutions for such bridges with an atypical arrangement of cables and additional pylons are already applied in practice. The article discusses an innovative pre-tensioned intersecting cable steel bridge structure system. The behavior of this bridge system under permanent and temporary loads is analyzed. Based on the performed numerical experiment, the efficiency of the innovative cable-stayed steel bridge system was determined. This newly designed bridge system is more effective in terms of stress and displacement distribution than a classic cable-stayed bridge system.
{"title":"BEHAVIOR OF PRE-STRESSED INTERSECTING CABLE STEEL BRIDGE","authors":"P. Dabrila","doi":"10.3846/est.2021.18402","DOIUrl":"https://doi.org/10.3846/est.2021.18402","url":null,"abstract":"Cable-stayed bridges are known as one of the most effective and graceful forms of bridges. The main problem in the design of cable-stayed steel bridges is their deformability, especially under asymmetrical loads. Stabilization of the initial form of cable-stayed bridges can be achieved by selecting the appropriate cross-sectional area of the cables and their pre-stressing, as well as by increasing the cross-sectional height of the stiffness beam. However, a greater effect can be achieved by applying new forms of such bridges. Solutions for such bridges with an atypical arrangement of cables and additional pylons are already applied in practice. The article discusses an innovative pre-tensioned intersecting cable steel bridge structure system. The behavior of this bridge system under permanent and temporary loads is analyzed. Based on the performed numerical experiment, the efficiency of the innovative cable-stayed steel bridge system was determined. This newly designed bridge system is more effective in terms of stress and displacement distribution than a classic cable-stayed bridge system.","PeriodicalId":11839,"journal":{"name":"Engineering Structures and Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47281767","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}
In the present paper, a new concept of favorable probability is proposed first, and a simplified approach for multi-criteria decision-making is developed on basis of probability theory. It assumes that all the performance indexes of all alternatives can be divided into beneficial and unbeneficial types in the multi-criteria decision-making, and each performance index of all alternative makes its contribution to a partial favorable probability in positively or negatively correlative manners linearly upon its type of beneficial or unbeneficial; the partial favorable probability of each performance index with the same physical meaning is normalized in the alternative group; the product of all partial favorable probability of an alternative makes the total favorable probability of the alternative. As a consequence, all the alternatives can be ranked according to their total favorable probability comparatively in the multi-criteria decision-making. As application examples of the new method, the quantitative assessment of multi-criteria selection for effective dwelling house walls, project managers and contractor for construction works are given in detail, satisfied results are obtained.
{"title":"A SIMPLE APPROACH FOR MULTI-CRITERIA DECISION-MAKING ON BASIS OF PROBABILITY THEORY","authors":"M. Zheng, H. Teng, Yi Wang","doi":"10.3846/est.2021.18404","DOIUrl":"https://doi.org/10.3846/est.2021.18404","url":null,"abstract":"In the present paper, a new concept of favorable probability is proposed first, and a simplified approach for multi-criteria decision-making is developed on basis of probability theory. It assumes that all the performance indexes of all alternatives can be divided into beneficial and unbeneficial types in the multi-criteria decision-making, and each performance index of all alternative makes its contribution to a partial favorable probability in positively or negatively correlative manners linearly upon its type of beneficial or unbeneficial; the partial favorable probability of each performance index with the same physical meaning is normalized in the alternative group; the product of all partial favorable probability of an alternative makes the total favorable probability of the alternative. As a consequence, all the alternatives can be ranked according to their total favorable probability comparatively in the multi-criteria decision-making. As application examples of the new method, the quantitative assessment of multi-criteria selection for effective dwelling house walls, project managers and contractor for construction works are given in detail, satisfied results are obtained.","PeriodicalId":11839,"journal":{"name":"Engineering Structures and Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44317024","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 article consists of 3 parts. String analyzes with symmetrical loading, combined parametric analyzes of string structure with symmetrical loading and combined string structure analyzes with asymmetrical loading. Through various parameters, the influence of different parameters of the string on its behavior is revealed. The influence of prestressing in the combined string structure is also released. To assess the correctness of the results, an experimental study was carried out in the laboratory, after the structure was designed from steel elements.
{"title":"ANALYSIS FOR SYMMETRICAL AND ASYMMETRICAL LOADING OF A SINGLE-SPAN COMBINED STRING STEEL STRUCTURE","authors":"Edmundas Beivydas Edmundas Beivydas","doi":"10.3846/est.2022.18403","DOIUrl":"https://doi.org/10.3846/est.2022.18403","url":null,"abstract":"The article consists of 3 parts. String analyzes with symmetrical loading, combined parametric analyzes of string structure with symmetrical loading and combined string structure analyzes with asymmetrical loading. Through various parameters, the influence of different parameters of the string on its behavior is revealed. The influence of prestressing in the combined string structure is also released. To assess the correctness of the results, an experimental study was carried out in the laboratory, after the structure was designed from steel elements.","PeriodicalId":11839,"journal":{"name":"Engineering Structures and Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46740002","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 describes some of the experiments carried out at the Chair of Steel and Timber Construction to reinforce steel with adhesively bonded CFRP lamellas. The first topic deals with the repair of cracks in steel structures exposed to fatigue. The aim was to extend the remaining service life of these components by means of adhesively bonded CFRP lamellas and then to compare the results obtained with established methods for repairing cracks. In order to improve the informative value of the investigations, several test parameters such as adhesive candidates, temperature, creep effects, degrees of prestressing, load levels and the position of the reinforcement measures were varied. The second set of topics examined the extent to which a typical steel beam-to-column connection can be reinforced with the help of adhesively bonded CFRP lamellas.
{"title":"EXPERIMENTAL INVESTIGATIONS ON INNOVATIVE CRACK REPAIR METHODS AND REINFORCING STEEL STRUCTURES WITH ADHESIVLY BONDED CFRP – LAMELLAS","authors":"Florian Sternsdorff, Y. Ciupack, H. Pasternak","doi":"10.3846/est.2021.15036","DOIUrl":"https://doi.org/10.3846/est.2021.15036","url":null,"abstract":"The paper describes some of the experiments carried out at the Chair of Steel and Timber Construction to reinforce steel with adhesively bonded CFRP lamellas.\u0000The first topic deals with the repair of cracks in steel structures exposed to fatigue. The aim was to extend the remaining service life of these components by means of adhesively bonded CFRP lamellas and then to compare the results obtained with established methods for repairing cracks. In order to improve the informative value of the investigations, several test parameters such as adhesive candidates, temperature, creep effects, degrees of prestressing, load levels and the position of the reinforcement measures were varied.\u0000The second set of topics examined the extent to which a typical steel beam-to-column connection can be reinforced with the help of adhesively bonded CFRP lamellas.","PeriodicalId":11839,"journal":{"name":"Engineering Structures and Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43211104","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}
A techno-economic analysis is performed for a solar farm with a 35 MWe installed capacity using bifacial solar panels and compared with standard monofacial solar panels at the same installed capacity level. The bifacial panel usage gain from total panel efficiency is identified from 4-year measurements to be within a range of 7.9–16.8% depending on monthly yield. A Monte Carlo simulation is carried out to forecast electricity prices under uncertainty. In terms of Net Present Value, it is found that the bifacial farm yields 12.6% higher values than the monofacial options under reference assumptions. An incremental internal rate of return (IRR) analysis is carried out yielding an IRR for the bifacial panels of 44% under various scenarios. The sensitivity analysis reveals that results are highly sensitive to discount rate and lifetime, and less sensitive to electricity prices. SWOT analysis performed to compare the bifacial with the monofacial panel and evaluate panels according to internal and external factors. The study was concluded with a summary of the technical specifications based on the test results. The results were used to identify that 12.2% added net present value corresponding to $186.7 – $214.5 per unit MW (under various electricity price trajectories) can be used as a reference for assessing the benefit for usage of bifacial PV for 35 MW type medium-size projects. In summary, it is suggested that bifacial solar PV with its outstanding techno-economic results can be the driving force of the growing solar PV market.
{"title":"TECHNO-ECONOMIC COMPARISON OF BIFACIAL VS MONOFACIAL SOLAR PANELS","authors":"Gürkan Kumbaroglu, M. E. Çamlibel, Cem Avcı","doi":"10.3846/est.2021.17181","DOIUrl":"https://doi.org/10.3846/est.2021.17181","url":null,"abstract":"A techno-economic analysis is performed for a solar farm with a 35 MWe installed capacity using bifacial solar panels and compared with standard monofacial solar panels at the same installed capacity level. The bifacial panel usage gain from total panel efficiency is identified from 4-year measurements to be within a range of 7.9–16.8% depending on monthly yield. A Monte Carlo simulation is carried out to forecast electricity prices under uncertainty. In terms of Net Present Value, it is found that the bifacial farm yields 12.6% higher values than the monofacial options under reference assumptions. An incremental internal rate of return (IRR) analysis is carried out yielding an IRR for the bifacial panels of 44% under various scenarios. The sensitivity analysis reveals that results are highly sensitive to discount rate and lifetime, and less sensitive to electricity prices. SWOT analysis performed to compare the bifacial with the monofacial panel and evaluate panels according to internal and external factors. The study was concluded with a summary of the technical specifications based on the test results. The results were used to identify that 12.2% added net present value corresponding to $186.7 – $214.5 per unit MW (under various electricity price trajectories) can be used as a reference for assessing the benefit for usage of bifacial PV for 35 MW type medium-size projects. In summary, it is suggested that bifacial solar PV with its outstanding techno-economic results can be the driving force of the growing solar PV market.","PeriodicalId":11839,"journal":{"name":"Engineering Structures and Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44367370","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 stiffness analysis of the simple supported hybrid bisteel I-section beam subjected by uniformly distributed load is considered in this paper. The hybrid bisteel I-section beam presents a composition of high-strength steel inclusions for the flanges in the region of maximum stresses and of low-strength steel for remaining volume of the beam. The explicit analytical model for evaluation of stiffness of the beams mentioned is presented. The geometrical linear approach and elastic plastic material model have been assumed. The application of high-strength steel inclusion in case perfectly elastic state of the hybrid bisteel I-section beam, increase the deflection insignificantly (up to 10%). While strain hardening effect reduces the deflection by about 4 times compared to the perfect plasticity. The verification of the theoretical analysis has been performed by the FEM. After simple transformations, the proposed model can be easily applied to the evaluation of stiffness of otherwise loaded and supported hybrid bisteel I-section beams.
{"title":"THE INVESTIGATION OF STIFFNESS OF HYBRID BISTEEL I-SECTION BEAMS","authors":"A. Jaras","doi":"10.3846/EST.2020.15120","DOIUrl":"https://doi.org/10.3846/EST.2020.15120","url":null,"abstract":"The stiffness analysis of the simple supported hybrid bisteel I-section beam subjected by uniformly distributed load is considered in this paper. The hybrid bisteel I-section beam presents a composition of high-strength steel inclusions for the flanges in the region of maximum stresses and of low-strength steel for remaining volume of the beam. The explicit analytical model for evaluation of stiffness of the beams mentioned is presented. The geometrical linear approach and elastic plastic material model have been assumed. The application of high-strength steel inclusion in case perfectly elastic state of the hybrid bisteel I-section beam, increase the deflection insignificantly (up to 10%). While strain hardening effect reduces the deflection by about 4 times compared to the perfect plasticity. The verification of the theoretical analysis has been performed by the FEM. After simple transformations, the proposed model can be easily applied to the evaluation of stiffness of otherwise loaded and supported hybrid bisteel I-section beams.","PeriodicalId":11839,"journal":{"name":"Engineering Structures and Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48319898","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}
Suspension bridges are characterized by exceptional architectural expressions and excellent technical and economic properties. However, despite all advantages, suspension bridges have a few negative features. Suspension bridges with flexible cables share excessive deformation caused by the displacement of kinematic origin. In order to increase the stiffness of suspension bridges, an innovative structural solution refers to rigid cables used instead of the flexible ones. The paper describes a methodology for calculating an asymmetric single-pylon suspension bridge with rigid cables considering installation features. Also, the article presents the numerical simulation of the bridge and determines the accuracy of the proposed methodology.
{"title":"THE SIMPLIFIED ANALYSIS OF THE ASYMMETRIC SINGLE-PYLON SUSPENSION BRIDGE WITH RIGID CABLES","authors":"Tatjana Grigorjeva, A. Paeglitis","doi":"10.3846/EST.2020.13737","DOIUrl":"https://doi.org/10.3846/EST.2020.13737","url":null,"abstract":"Suspension bridges are characterized by exceptional architectural expressions and excellent technical and economic properties. However, despite all advantages, suspension bridges have a few negative features. Suspension bridges with flexible cables share excessive deformation caused by the displacement of kinematic origin. In order to increase the stiffness of suspension bridges, an innovative structural solution refers to rigid cables used instead of the flexible ones. The paper describes a methodology for calculating an asymmetric single-pylon suspension bridge with rigid cables considering installation features. Also, the article presents the numerical simulation of the bridge and determines the accuracy of the proposed methodology.","PeriodicalId":11839,"journal":{"name":"Engineering Structures and Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48913478","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}
Loreta Kanapeckiene, L. Tupėnaitė, G. Jucienė, I. Geipele
Development of real estate has the potential to advance sustainability. This is particularly important in residential sector as it plays a crucial role in the lives of habitats and directly influences their welfare. As populations grow and cities expand, the demand for real estate increases and construction volumes rise. Assurance of sustainability in the residential projects becomes a new concern of real estate developers and construction companies. This article aims to analyse in more detail the concept of a sustainable residential construction and the evaluation criteria. In the first part the concept of sustainable development and its dimensions in residential construction are analysed. The second part describes the research methodology. In the third part, the research methodology is applied to the evaluation of five residential construction projects in Vilnius, Lithuania. The fourth part describes the possibilities of using wooden construction to improve the sustainability of residential construction projects.
{"title":"SUSTAINABILITY ASSESSMENT OF THE RESIDENTIAL CONSTRUCTION PROJECTS IN LITHUANIA","authors":"Loreta Kanapeckiene, L. Tupėnaitė, G. Jucienė, I. Geipele","doi":"10.3846/EST.2020.14933","DOIUrl":"https://doi.org/10.3846/EST.2020.14933","url":null,"abstract":"Development of real estate has the potential to advance sustainability. This is particularly important in residential sector as it plays a crucial role in the lives of habitats and directly influences their welfare. As populations grow and cities expand, the demand for real estate increases and construction volumes rise. Assurance of sustainability in the residential projects becomes a new concern of real estate developers and construction companies.\u0000This article aims to analyse in more detail the concept of a sustainable residential construction and the evaluation criteria. In the first part the concept of sustainable development and its dimensions in residential construction are analysed. The second part describes the research methodology. In the third part, the research methodology is applied to the evaluation of five residential construction projects in Vilnius, Lithuania. The fourth part describes the possibilities of using wooden construction to improve the sustainability of residential construction projects.","PeriodicalId":11839,"journal":{"name":"Engineering Structures and Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43356472","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}
For industrial buildings and logistics centres truck lifts are usually used. Therefore, there are special requirements for flatness tolerance of ground floor. The ground floor settlements differences in selected distances are limited. The article reviews the behaviour of soils and the importance of the actual behaviour assessment of soils during the design of floor slab on elastic subgrade. Particular attention is given to the behaviour of floor slab areas above pile foundations that support the building’s columns. Calculation results show the impact of subgrade stiffness on the behaviour of the floor slab, especially in areas above pile foundations, where the stiffness of subgrade is much higher. The article presents a solution for achieving the required level of settlements’ differences in areas where pile foundations for the building’s columns under the ground slab are used. The paper proposes an efficient engineering method to reduce ground slab settlements differences. The results of performed calculations confirm the efficiency of presented method.
{"title":"THE ENGINEERING METHOD FOR UNIFYING GROUND FLOOR SLAB SETTLEMENTS","authors":"Kestutis Urbonas, D. Sližytė, A. Šapalas","doi":"10.3846/EST.2020.14555","DOIUrl":"https://doi.org/10.3846/EST.2020.14555","url":null,"abstract":"For industrial buildings and logistics centres truck lifts are usually used. Therefore, there are special requirements for flatness tolerance of ground floor. The ground floor settlements differences in selected distances are limited. The article reviews the behaviour of soils and the importance of the actual behaviour assessment of soils during the design of floor slab on elastic subgrade. Particular attention is given to the behaviour of floor slab areas above pile foundations that support the building’s columns. Calculation results show the impact of subgrade stiffness on the behaviour of the floor slab, especially in areas above pile foundations, where the stiffness of subgrade is much higher. The article presents a solution for achieving the required level of settlements’ differences in areas where pile foundations for the building’s columns under the ground slab are used. The paper proposes an efficient engineering method to reduce ground slab settlements differences. The results of performed calculations confirm the efficiency of presented method.","PeriodicalId":11839,"journal":{"name":"Engineering Structures and Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49241793","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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