Pub Date : 2024-01-31DOI: 10.3390/infrastructures9020024
Mehran Vahedi Nikbakht, M. Gheibi, Hassan Montazeri, Reza Yeganeh Khaksar, R. Moezzi, Amir Vadiee
Construction projects, especially those for commercial purposes, require thorough planning and control to ensure success within predetermined budgets and timelines. This research, conducted in Mashhad, Iran, employs the analytic hierarchy process (AHP) and VIKOR methods to identify and rank factors influencing delays in high-rise projects. The study, based on a sample of 40 projects, emphasizes the comprehensive nature of our research method. The scale for features in project selection includes societal importance (with different applications including cultural hubs, affordable housing initiatives, and urban renewal for social equity), size (less and more than 20 units in residential projects), and diversity (mixed-use development, inclusive infrastructure, and cultural and recreational spaces), contributing to a comprehensive analysis of construction delays. Expert project managers and engineers provided insights through two questionnaires, and their responses underwent thorough analysis. Our findings not only underscore the significance of factors contributing to project success but also rank their impact on the likelihood of delays. The study reveals that the negative effects of these factors on cost, time, and project quality vary. Time emerges as the most influential parameter, with approximately six times more impact on cost and nine times more on quality. Contractor financial weakness, delays in allocating financial and credit resources, insufficient project resource allocation, contractor technical and executive weakness, and a lack of proper implementation and project control are identified as the most important factors contributing to delays.
{"title":"Identification and Ranking of Factors Affecting the Delay Risk of High-Rise Construction Projects Using AHP and VIKOR Methods","authors":"Mehran Vahedi Nikbakht, M. Gheibi, Hassan Montazeri, Reza Yeganeh Khaksar, R. Moezzi, Amir Vadiee","doi":"10.3390/infrastructures9020024","DOIUrl":"https://doi.org/10.3390/infrastructures9020024","url":null,"abstract":"Construction projects, especially those for commercial purposes, require thorough planning and control to ensure success within predetermined budgets and timelines. This research, conducted in Mashhad, Iran, employs the analytic hierarchy process (AHP) and VIKOR methods to identify and rank factors influencing delays in high-rise projects. The study, based on a sample of 40 projects, emphasizes the comprehensive nature of our research method. The scale for features in project selection includes societal importance (with different applications including cultural hubs, affordable housing initiatives, and urban renewal for social equity), size (less and more than 20 units in residential projects), and diversity (mixed-use development, inclusive infrastructure, and cultural and recreational spaces), contributing to a comprehensive analysis of construction delays. Expert project managers and engineers provided insights through two questionnaires, and their responses underwent thorough analysis. Our findings not only underscore the significance of factors contributing to project success but also rank their impact on the likelihood of delays. The study reveals that the negative effects of these factors on cost, time, and project quality vary. Time emerges as the most influential parameter, with approximately six times more impact on cost and nine times more on quality. Contractor financial weakness, delays in allocating financial and credit resources, insufficient project resource allocation, contractor technical and executive weakness, and a lack of proper implementation and project control are identified as the most important factors contributing to delays.","PeriodicalId":502683,"journal":{"name":"Infrastructures","volume":"545 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140471137","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 : 2024-01-31DOI: 10.3390/infrastructures9020025
Z. Al-Saffar, Heja Ghazi Mohamed Hasan, Salam Ridha Oleiwi Aletba
This research addresses the significant challenge posed by early water damage in highway asphalt pavement, a critical concern affecting pavement service performance. To counteract this issue, the utilization of anti-stripping agents in asphalt is explored as a highly effective technical intervention. In this investigation, a carefully selected amine-free additive was employed to modify the asphalt binder. A comprehensive array of physical and rheological tests, covering aspects such as storage stability, penetration, softening point, ductility, elastic recovery, rolling thin-film oven, retained penetration, the ductility of residue, and rotational viscometer assessments, were conducted to examine the multifaceted impact of the anti-stripping agent on the asphalt binder. Additionally, we assessed the asphalt mixture’s sensitivity to moisture through Marshall stability tests after conditioning for 40 min and 24 h, followed by an enhanced immersion test and moisture susceptibility measurement. The results reveal a nuanced interplay of chemical and physical mechanisms influencing the behavior of the asphalt binder. Notably, the incorporation of an anti-stripping agent at a concentration of 0.25–0.5% (by weight of asphalt binder) led to a substantial improvement in the tensile strength ratio (TSR) to 94.9%, a noteworthy enhancement compared to the 80.6% observed with virgin asphalt mixture. Furthermore, the retained stability index (RSI) exhibited a remarkable increase to 98.1%, surpassing the 87.6% recorded for virgin asphalt. This study not only provides crucial insights into the intricate dynamics of asphalt binder performance but also emphasizes the pivotal role of anti-stripping agents in augmenting the structural integrity and resilience of asphalt pavement.
{"title":"Exploring the Efficacy of Amine-Free Anti-Stripping Agent in Improving Asphalt Characteristics","authors":"Z. Al-Saffar, Heja Ghazi Mohamed Hasan, Salam Ridha Oleiwi Aletba","doi":"10.3390/infrastructures9020025","DOIUrl":"https://doi.org/10.3390/infrastructures9020025","url":null,"abstract":"This research addresses the significant challenge posed by early water damage in highway asphalt pavement, a critical concern affecting pavement service performance. To counteract this issue, the utilization of anti-stripping agents in asphalt is explored as a highly effective technical intervention. In this investigation, a carefully selected amine-free additive was employed to modify the asphalt binder. A comprehensive array of physical and rheological tests, covering aspects such as storage stability, penetration, softening point, ductility, elastic recovery, rolling thin-film oven, retained penetration, the ductility of residue, and rotational viscometer assessments, were conducted to examine the multifaceted impact of the anti-stripping agent on the asphalt binder. Additionally, we assessed the asphalt mixture’s sensitivity to moisture through Marshall stability tests after conditioning for 40 min and 24 h, followed by an enhanced immersion test and moisture susceptibility measurement. The results reveal a nuanced interplay of chemical and physical mechanisms influencing the behavior of the asphalt binder. Notably, the incorporation of an anti-stripping agent at a concentration of 0.25–0.5% (by weight of asphalt binder) led to a substantial improvement in the tensile strength ratio (TSR) to 94.9%, a noteworthy enhancement compared to the 80.6% observed with virgin asphalt mixture. Furthermore, the retained stability index (RSI) exhibited a remarkable increase to 98.1%, surpassing the 87.6% recorded for virgin asphalt. This study not only provides crucial insights into the intricate dynamics of asphalt binder performance but also emphasizes the pivotal role of anti-stripping agents in augmenting the structural integrity and resilience of asphalt pavement.","PeriodicalId":502683,"journal":{"name":"Infrastructures","volume":"527 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140476822","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 : 2024-01-30DOI: 10.3390/infrastructures9020023
Can Tang, Xinchao Hou, Yanjie Xu, Feng Jin
A rock-filled concrete (RFC) dam is an original dam construction technology invented in China nearly 20 years ago. The technology has been continuously improved and innovated upon, and the accumulated rich practical experience gradually formed a complete dam design and construction technology. Seismic design is a key design area for RFC dams that still requires more investigation; therefore, this article attempts to address some questions in this area. In the article, the seismic design for a curved gravity dam, currently under construction, is compared for RFC and conventional vibrating concrete (CVC) dam alternatives based on American design documents. The conclusions drawn from investigations include the following: The displacement and stress distributions in both the CVC and RFC alternatives are similar, but the maximum computed values for the RFC dam model are slightly smaller than those for the CVC one, while the sliding resistance of both dam alternatives can meet the requirements of the specifications. Regarding the nonlinear seismic analysis results, the extent of damage in the RFC dam model is significantly reduced when compared with the CVC model, which can be explained by the higher cracking resistance of RFC. In general, the seismic performance of the investigated dam made of RFC appears to be better than that of CVC.
{"title":"Seismic Behavior of Rock-Filled Concrete Dam Compared with Conventional Vibrating Concrete Dam Using Finite Element Method","authors":"Can Tang, Xinchao Hou, Yanjie Xu, Feng Jin","doi":"10.3390/infrastructures9020023","DOIUrl":"https://doi.org/10.3390/infrastructures9020023","url":null,"abstract":"A rock-filled concrete (RFC) dam is an original dam construction technology invented in China nearly 20 years ago. The technology has been continuously improved and innovated upon, and the accumulated rich practical experience gradually formed a complete dam design and construction technology. Seismic design is a key design area for RFC dams that still requires more investigation; therefore, this article attempts to address some questions in this area. In the article, the seismic design for a curved gravity dam, currently under construction, is compared for RFC and conventional vibrating concrete (CVC) dam alternatives based on American design documents. The conclusions drawn from investigations include the following: The displacement and stress distributions in both the CVC and RFC alternatives are similar, but the maximum computed values for the RFC dam model are slightly smaller than those for the CVC one, while the sliding resistance of both dam alternatives can meet the requirements of the specifications. Regarding the nonlinear seismic analysis results, the extent of damage in the RFC dam model is significantly reduced when compared with the CVC model, which can be explained by the higher cracking resistance of RFC. In general, the seismic performance of the investigated dam made of RFC appears to be better than that of CVC.","PeriodicalId":502683,"journal":{"name":"Infrastructures","volume":"138 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140485001","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 : 2024-01-30DOI: 10.3390/infrastructures9020022
Julián Pulecio-Díaz, M. Sol-Sánchez, F. Moreno-Navarro
Roller-compacted concrete (RCC) pavements have been the subject of studies focused on their increasing deterioration over time due to the influence of vehicular loading and ambient factors in humidity and temperature conditions ranging from medium to low (40% relative humidity and 25 °C temperature). Therefore, it is necessary to understand how they behave under various relative humidity and temperature conditions since these parameters vary in each geographic region. In this context, this research focused on analyzing the effect of drying shrinkage on RCC pavements under the influence of vehicular loading using a computational model calibrated with data obtained under typical ambient conditions. For this purpose, laboratory experiments were performed, numerical modeling was used, and the results for RCC pavements were validated using statistical analysis. The results revealed validated models providing moisture content and drying shrinkage curves. These results also underline the importance of considering ambient effects when calculating pavement stresses as a response variable in structural designs. In particular, these effects are highlighted as they can generate changes in pavement stresses of up to 10%, emphasizing the relevance of the models proposed in this study as they consider this phenomenon when predicting the performance and durability of RCC pavements.
{"title":"Effects of Relative Humidity and Temperature on the Drying Shrinkage of Roller-Compacted Concrete Pavements","authors":"Julián Pulecio-Díaz, M. Sol-Sánchez, F. Moreno-Navarro","doi":"10.3390/infrastructures9020022","DOIUrl":"https://doi.org/10.3390/infrastructures9020022","url":null,"abstract":"Roller-compacted concrete (RCC) pavements have been the subject of studies focused on their increasing deterioration over time due to the influence of vehicular loading and ambient factors in humidity and temperature conditions ranging from medium to low (40% relative humidity and 25 °C temperature). Therefore, it is necessary to understand how they behave under various relative humidity and temperature conditions since these parameters vary in each geographic region. In this context, this research focused on analyzing the effect of drying shrinkage on RCC pavements under the influence of vehicular loading using a computational model calibrated with data obtained under typical ambient conditions. For this purpose, laboratory experiments were performed, numerical modeling was used, and the results for RCC pavements were validated using statistical analysis. The results revealed validated models providing moisture content and drying shrinkage curves. These results also underline the importance of considering ambient effects when calculating pavement stresses as a response variable in structural designs. In particular, these effects are highlighted as they can generate changes in pavement stresses of up to 10%, emphasizing the relevance of the models proposed in this study as they consider this phenomenon when predicting the performance and durability of RCC pavements.","PeriodicalId":502683,"journal":{"name":"Infrastructures","volume":"210 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140485496","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 : 2024-01-27DOI: 10.3390/infrastructures9020021
Greg White
Airport pavements have always evolved to keep pace with the demands of new aircraft. As aircraft weights and tyre pressures increase, stronger, new pavements are designed and existing pavements are rehabilitated or upgraded. The narrow-body commercial jet aircraft, including the A320 and B737 families, are examples of aircraft that have retained the same number of wheels, with the same wheel spacing and the same wingspan, but have increased in weight and tyre pressure by approximately 50%. This places significant demand on airport pavements that were designed for the lighter variants but now face the introduction of the newer, heavier and more demanding variants. This research quantified the impact of the new A320 and B737 narrow-body aircraft variants on rigid and flexible regional airport pavements, where these are the critical aircraft, as well as demonstrating the importance of understanding the operational weight limitations of these aircraft, which is often well below the published maximum weight. Within the context of the pavements considered, the additional pavement thickness required for the heaviest aircraft variants, compared to the lightest variants, was 51%. Based on four examples from real regional airports in Australia, it was found that the additional embodied carbon associated with these new aircraft variants was 2.1–85.3 kg·eCO2/m2 of pavement, while the additional financial cost was AUD 6–219/m2 of pavement. It was concluded that airport pavement thickness designers must challenge the weight of the design aircraft and not take the simple and conservative approach of adopting the maximum weight of the heaviest variant within each aircraft family. By doing so, significant additional pavement thickness will be constructed for no practical benefit, creating an environmental (embodied carbon) and economic (financial cost) burden.
{"title":"Analysis of the Impact of New Generation Narrow-Body Aircraft on Flexible and Rigid Regional Airport Pavements","authors":"Greg White","doi":"10.3390/infrastructures9020021","DOIUrl":"https://doi.org/10.3390/infrastructures9020021","url":null,"abstract":"Airport pavements have always evolved to keep pace with the demands of new aircraft. As aircraft weights and tyre pressures increase, stronger, new pavements are designed and existing pavements are rehabilitated or upgraded. The narrow-body commercial jet aircraft, including the A320 and B737 families, are examples of aircraft that have retained the same number of wheels, with the same wheel spacing and the same wingspan, but have increased in weight and tyre pressure by approximately 50%. This places significant demand on airport pavements that were designed for the lighter variants but now face the introduction of the newer, heavier and more demanding variants. This research quantified the impact of the new A320 and B737 narrow-body aircraft variants on rigid and flexible regional airport pavements, where these are the critical aircraft, as well as demonstrating the importance of understanding the operational weight limitations of these aircraft, which is often well below the published maximum weight. Within the context of the pavements considered, the additional pavement thickness required for the heaviest aircraft variants, compared to the lightest variants, was 51%. Based on four examples from real regional airports in Australia, it was found that the additional embodied carbon associated with these new aircraft variants was 2.1–85.3 kg·eCO2/m2 of pavement, while the additional financial cost was AUD 6–219/m2 of pavement. It was concluded that airport pavement thickness designers must challenge the weight of the design aircraft and not take the simple and conservative approach of adopting the maximum weight of the heaviest variant within each aircraft family. By doing so, significant additional pavement thickness will be constructed for no practical benefit, creating an environmental (embodied carbon) and economic (financial cost) burden.","PeriodicalId":502683,"journal":{"name":"Infrastructures","volume":"40 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140492307","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 : 2024-01-15DOI: 10.3390/infrastructures9010014
Lama Ayad, H. Imine, C. Lantieri, Francesca De Crescenzio
Cyclists are at a higher risk of being involved in accidents. To this end, a safer environment for cyclists should be pursued so that they can feel safe while riding their bicycles. Focusing on safety risks that cyclists may face is the main key to preserving safe mobility, reducing accidents, and improving their level of safety during their travel. Identifying and assessing risk factors, as well as informing cyclists about them may lead to an efficient and integrated transportation system. Therefore, the purpose of this research is to introduce a risk index that can be adapted to different road areas in order to measure the degree of how risky these areas are for biking. Cyclists’ behavior and demographics were integrated into the risk index calculation. The methodology followed to obtain the risk index composed of four phases: risk factor identification, risk factor weighting, risk index formulation, and risk index validation. Nineteen risk factors are categorized into four major groups: facility features, infrastructure features, cyclist behavior, and weather and traffic conditions.
{"title":"Pedal towards Safety: The Development and Evaluation of a Risk Index for Cyclists","authors":"Lama Ayad, H. Imine, C. Lantieri, Francesca De Crescenzio","doi":"10.3390/infrastructures9010014","DOIUrl":"https://doi.org/10.3390/infrastructures9010014","url":null,"abstract":"Cyclists are at a higher risk of being involved in accidents. To this end, a safer environment for cyclists should be pursued so that they can feel safe while riding their bicycles. Focusing on safety risks that cyclists may face is the main key to preserving safe mobility, reducing accidents, and improving their level of safety during their travel. Identifying and assessing risk factors, as well as informing cyclists about them may lead to an efficient and integrated transportation system. Therefore, the purpose of this research is to introduce a risk index that can be adapted to different road areas in order to measure the degree of how risky these areas are for biking. Cyclists’ behavior and demographics were integrated into the risk index calculation. The methodology followed to obtain the risk index composed of four phases: risk factor identification, risk factor weighting, risk index formulation, and risk index validation. Nineteen risk factors are categorized into four major groups: facility features, infrastructure features, cyclist behavior, and weather and traffic conditions.","PeriodicalId":502683,"journal":{"name":"Infrastructures","volume":"26 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139529300","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 : 2024-01-12DOI: 10.3390/infrastructures9010013
Wadslin Frenelus, Hui Peng, Jingyu Zhang
The stability of deep soft rock tunnels under seepage conditions is of particular concern. Aiming at thoroughly discussing seepage actions and their consequences on the support schemes of such structures, the host rocks of the Weilai Tunnel situated in the Guangxi province of China are used as the research subject. Emphasis is placed on adequately examining the seepage conditions, stresses, displacements and plastic zone radii along the surrounding rocks of such tunnels, taking into consideration the Mogi–Coulomb strength criterion and the elastic-plastic theory. Explicitly, this article proposes analytical solutions for stresses, displacements and plastic radii around deep tunnels in soft rocks under seepage conditions by considering the aforesaid criterion and nonlinear elastoplastic approaches. Subsequently, based on the strain-softening model, the coupled actions of seepage and softening on the rocks surrounding the tunnel are studied. In order to investigate the effects of relevant influencing factors on tunnel stability, parametric studies are thoroughly examined. According to the results, it is revealed that the support scheme of deep soft rock tunnels must be of the highest resistance possible to better decrease the plastic zone and the tangential stress along the host rocks. Moreover, throughout the surrounding rocks, the dissemination of pore water pressure is strongly affected by the uneven permeability coefficient under anisotropic seepage states. The combined effects of softening and seepage are very dangerous for the surrounding rocks of deep-buried tunnels. It is also shown that the seepage pressure substantially affects the plastic radii and tunnel displacements. Under high seepage pressure, the surface displacements of the tunnel are excessive, easily exceeding 400 mm. To better guarantee the reasonable longevity of such tunnels, the long-term monitoring of their support structures with reliable remote sensors is strongly recommended.
{"title":"Seepage Actions and Their Consequences on the Support Scheme of Deep-Buried Tunnels Constructed in Soft Rock Strata","authors":"Wadslin Frenelus, Hui Peng, Jingyu Zhang","doi":"10.3390/infrastructures9010013","DOIUrl":"https://doi.org/10.3390/infrastructures9010013","url":null,"abstract":"The stability of deep soft rock tunnels under seepage conditions is of particular concern. Aiming at thoroughly discussing seepage actions and their consequences on the support schemes of such structures, the host rocks of the Weilai Tunnel situated in the Guangxi province of China are used as the research subject. Emphasis is placed on adequately examining the seepage conditions, stresses, displacements and plastic zone radii along the surrounding rocks of such tunnels, taking into consideration the Mogi–Coulomb strength criterion and the elastic-plastic theory. Explicitly, this article proposes analytical solutions for stresses, displacements and plastic radii around deep tunnels in soft rocks under seepage conditions by considering the aforesaid criterion and nonlinear elastoplastic approaches. Subsequently, based on the strain-softening model, the coupled actions of seepage and softening on the rocks surrounding the tunnel are studied. In order to investigate the effects of relevant influencing factors on tunnel stability, parametric studies are thoroughly examined. According to the results, it is revealed that the support scheme of deep soft rock tunnels must be of the highest resistance possible to better decrease the plastic zone and the tangential stress along the host rocks. Moreover, throughout the surrounding rocks, the dissemination of pore water pressure is strongly affected by the uneven permeability coefficient under anisotropic seepage states. The combined effects of softening and seepage are very dangerous for the surrounding rocks of deep-buried tunnels. It is also shown that the seepage pressure substantially affects the plastic radii and tunnel displacements. Under high seepage pressure, the surface displacements of the tunnel are excessive, easily exceeding 400 mm. To better guarantee the reasonable longevity of such tunnels, the long-term monitoring of their support structures with reliable remote sensors is strongly recommended.","PeriodicalId":502683,"journal":{"name":"Infrastructures","volume":"35 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139532096","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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