Biogeotechnics最新文献

{"title":"Proposing a new sustainable approach for sand improvement using biologically-derived calcium phosphate cement","authors":"Sivakumar Gowthaman ,&nbsp;Yuta Kumamoto ,&nbsp;Kazunori Nakashima ,&nbsp;Chikara Takano ,&nbsp;Satoru Kawasaki","doi":"10.1016/j.bgtech.2024.100135","DOIUrl":"10.1016/j.bgtech.2024.100135","url":null,"abstract":"<div><div>Bio-mediated soil improvement methods keep on gaining the attention of geotechnical engineers and researchers globally due to their nature-based elegance and eco-friendliness. Most prevalent bio-mediated soil improvement methods include microbially induced carbonate precipitation (MICP) and enzyme-induced carbonate precipitation (EICP). During their processes, the bacteria/free urease hydrolyzes the urea into ammonium and carbonic acid, which is accompanied by a considerable increase of alkalinity (about pH 9.0). The major problem associated with the above techniques is the release of gaseous ammonia that is extremely detrimental. Therefore, this study aims to propose a new sustainable approach involving lactic acid bacteria to facilitate the calcium phosphate mineralization for the strengthening of sand matrix. The major objectives of this investigation are: (i) to evaluate the urease activity of the lactic acid bacteria under different temperatures, pH conditions and additions of metal ions, (ii) to assess the treated sand matrix, (iii) to perform cost analysis. The outcomes indicated that <em>Limosilactobacillus</em> sp. could effectively facilitate the urea hydrolysis, hence increasing the pH from acidic to neutral and providing a desirable environment for the calcium phosphate to mineralize within the voids of the sand. The addition of 0.01 % Ni²⁺ in culture media was found to enhance the urease activity by 38.8 % and compressive strength over 40 %. A combined formation of amorphous- and whisker-like precipitates could bridge a larger area at particle-particle contact points, thereby faciliating a strong force-network in sand matrix. The mineralized calcium phosphate compound was found to be brushite. The cost herein for producing 1 L treatment solution was estimated to be about 2.5-folds and 11.8-folds lower compared to that of MICP and EICP treatment solutions, respectively. Moreover, since the treatment pH could potentially be regulated between acidic-neural range, it would greatly control the release of gaseous ammonia. With several environmental and economical benefits, the study has disclosed a new sustainable direction for sand improvement via the use of lactic acid bacteria.</div></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"3 4","pages":"Article 100135"},"PeriodicalIF":0.0,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145230044","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}

{"title":"Effect of humic acid on soil solidification by enzyme induced carbonate precipitation","authors":"Meiqi Chen ,&nbsp;Aoi Ichinohe ,&nbsp;Kazunori Nakashima ,&nbsp;Chikara Takano ,&nbsp;Sivakumar Gowthaman ,&nbsp;Lutfian R. Daryono ,&nbsp;Satoru Kawasaki","doi":"10.1016/j.bgtech.2024.100133","DOIUrl":"10.1016/j.bgtech.2024.100133","url":null,"abstract":"<div><div>Enzyme induced carbonate precipitation (EICP) is a promising technique in the field of biocementation due to its efficiency and controllability. Although many studies have proved its reliability in different environment, little attention has been paid to the influence of humic substances on the EICP. Humic substances cover most of the surface soil across the world land with vegetation, which varies according to the density of vegetation and climate. To understand the compatibility of this technique to distinct problematic soils, it is important to figure out how humic substances could affect the carbonate precipitation process induced by urease enzyme. Therefore, this study aims to investigate the effects of humic acid (HA), one type of humic substance, on the soil solidification through EICP. For this purpose, HA was added to natural soil with varying addition amounts (0%, 1%, 2%, 4%, 8%, 16%) in soil column solidification tests. The results found that the cementation effectiveness was enhanced by a small amount of HA addition (&lt;4%), while an addition up to 8% greatly inhibited the formation of calcium carbonate. At the same time, soil samples were buffered by HA in a weak acidic condition, thus preventing the emission of undesirable by-product ammonia in the ureolysis process. Therefore, this study makes a contribution to research on enzymatic biocementation by demonstrating the effects of HA on the cementation effectiveness of EICP technique.</div></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"3 4","pages":"Article 100133"},"PeriodicalIF":0.0,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145229888","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}

{"title":"Development characteristics and quantitative analysis of cracks in root-soil complex during different growth periods under dry-wet cycles","authors":"Zhengjun Mao ,&nbsp;Xu Ma ,&nbsp;Mimi Geng ,&nbsp;Munan Wang ,&nbsp;Guangsheng Gao ,&nbsp;Yanshan Tian","doi":"10.1016/j.bgtech.2024.100121","DOIUrl":"10.1016/j.bgtech.2024.100121","url":null,"abstract":"<div><div>Repeated wet swelling and dry shrinkage of soil leads to the gradual occurrence of cracks and the formation of a complex fracture network. In order to study the development characteristics and quantitative analysis of cracks in root-soil complex in different growth periods under dry-wet cycles, the alfalfa root-loess complex was investigated during different growth periods under different dry-wet cycles, and a dry-wet cycle experiment was conducted. The crack rate, relative area, average width, total length, and the cracks fractal dimension in the root-soil complex were extracted; the crack development characteristics of plain soil were analyzed under the PG-DWC (dry-wet cycle caused by plant water management during plant growth period), as well as the crack development characteristics of root-soil complex under PG-DWC and EC-DWC (the dry-wet cycles caused by extreme natural conditions such as continuous rain); the effects of plant roots and dry-wet cycles on soil cracks were discussed. The results showed that the average crack width, crack rate, relative crack area, and total crack length of the alfalfa root-loess complex were higher than those of the plain soil during PG-DWC. The result indicated that compared with plain soil during PG-DWC, the presence of plant roots in alfalfa root-soil complex in the same growth period promoted the cracks development to some extent. The alfalfa root-soil complex crack parameters during different growth periods were relatively stable during PG-DWC (0 dry-wet cycle). During EC-DWC (1, 3, and 5 dry-wet cycles), the alfalfa root-loess complex crack parameters increased with the number of dry-wet cycles during different growth periods. Unlike PG-DWC, the EC-DWC accelerated crack development, and the degree of crack development increased with the number of dry-wet cycles. The existence of plant roots promoted crack development and expansion in the root-soil complex to a certain extent, and the dry-wet cycle certainly promoted crack development and expansion in the root-soil complex. This result contradicts the improvement in the root-soil complex's macro-mechanical properties during plant growth, due to differences in the mechanical properties of roots and soil. The research results will provide reference for the root soil complex crack development law and the design of slope protection by vegetation.</div></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"3 1","pages":"Article 100121"},"PeriodicalIF":0.0,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141839789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved methods, properties, applications and prospects of microbial induced carbonate precipitation (MICP) treated soil: A review","authors":"Xuanshuo Zhang ,&nbsp;Hongyu Wang ,&nbsp;Ya Wang ,&nbsp;Jinghui Wang ,&nbsp;Jing Cao ,&nbsp;Gang Zhang","doi":"10.1016/j.bgtech.2024.100123","DOIUrl":"10.1016/j.bgtech.2024.100123","url":null,"abstract":"<div><div>Soil improvement is one of the most important issues in geotechnical engineering practice. The wide application of traditional improvement techniques (cement/chemical materials) are limited due to damage ecological environment and intensify carbon emissions. However, the use of microbially induced calcium carbonate precipitation (MICP) to obtain bio-cement is a novel technique with the potential to induce soil stability, providing a low-carbon, environment-friendly, and sustainable integrated solution for some geotechnical engineering problems in the environment. This paper presents a comprehensive review of the latest progress in soil improvement based on the MICP strategy. It systematically summarizes and overviews the mineralization mechanism, influencing factors, improved methods, engineering characteristics, and current field application status of the MICP. Additionally, it also explores the limitations and correspondingly proposes prospective applications via the MICP approach for soil improvement. This review indicates that the utilization of different environmental calcium-based wastes in MICP and combination of materials and MICP are conducive to meeting engineering and market demand. Furthermore, we recommend and encourage global collaborative study and practice with a view to commercializing MICP technique in the future. The current review purports to provide insights for engineers and interdisciplinary researchers, and guidance for future engineering applications.</div></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"3 1","pages":"Article 100123"},"PeriodicalIF":0.0,"publicationDate":"2024-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141853611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biogenic construction: The new era of civil engineering","authors":"Hanlong Liu","doi":"10.1016/j.bgtech.2024.100130","DOIUrl":"10.1016/j.bgtech.2024.100130","url":null,"abstract":"<div><div>With the increasing demand for buildings and infrastructures and the mounting challenges associated with the current construction technologies such as high emission, high pollution, and high energy consumption, the civil engineering profession is at the crossroad for a transformation or upgrading before it can be put into tasks for these challenges. Inspired by the concept of harmonious coexistence between humans and nature, a new concept, biogenic construction, for civil engineering is proposed in this paper. The definition of biogenic construction is given. The framework and four components of biogenic construction are established. These include microbial construction, plant construction, animal construction, and bioinspired construction. Examples of each component are given. A new construction system for creating a more eco-friendly, healthier, and more sustainable environment for future civil engineering developments is also proposed.</div></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"3 1","pages":"Article 100130"},"PeriodicalIF":0.0,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141842243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on migration and diffusion law of MICP solution in fractured loess","authors":"Xiaojun Liu ,&nbsp;Chaofan Pan ,&nbsp;Lin Feng","doi":"10.1016/j.bgtech.2024.100122","DOIUrl":"10.1016/j.bgtech.2024.100122","url":null,"abstract":"<div><div>In this paper, according to the migration and diffusion law of MICP solution in fracture-pore medium, the migration and diffusion equation of MICP solution in loess fracture-pore medium was derived first. Then, the migration and diffusion test was carried out by using the self-made Mdevice. In the model, the apertures of the fracture of 0.5 mm, 1.0 mm and 1.5 mm were selected, and the calcium ion concentrations at different points were measured by atomic absorption method, to obtain the distribution map of calcium ion concentration. According to the test results, the migration speed of calcium ions in the direction along the fracture is less than the diffusion speed of the wet peak, and the vertical fracture direction is faster than the diffusion speed of the wet peak. The distribution range of calcium ion concentration increases first and then decreases with the increase in fracture opening. COMSOL was used to compile the mathematical equation, and the whole process of MICP solution migration and diffusion was numerically simulated. The numerical calculation results are basically consistent with the experimental results, and the derived mathematical equation is reasonable.</div></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"3 4","pages":"Article 100122"},"PeriodicalIF":0.0,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141841813","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}

{"title":"Influence of grass plantation on the rainfall-induced instability of gentle loose fill slope","authors":"Pei Tai ,&nbsp;Fan Wu ,&nbsp;Bohan Bai ,&nbsp;Zhaofeng Li ,&nbsp;Rui Chen ,&nbsp;Lulu Zhang","doi":"10.1016/j.bgtech.2024.100101","DOIUrl":"10.1016/j.bgtech.2024.100101","url":null,"abstract":"<div><p>The understanding of rainfall-induced landslides on gentle, loose-fill slopes is limited in comparison to steep slopes. Hence, two physical model tests were conducted on silty sand slopes under continuous rainfall: one on a bare slope and the other on a slope planted with ryegrass. The slope angle of 25° is much lower than the internal friction angle of slope material (34.3°), which makes the model test fall well into the category of gentle slope. For the initially unsaturated bare slope, a rainfall event with return period of 18 years could trigger a rapid and retrogressive global sliding, which differs from previous findings that gentle slopes would only experience shallow failure. A sudden increase in pore-water pressure was simultaneously observed, which might be generated by the wetting-induced collapse of unsaturated loose soil. On the other hand, the stability of the slope with grass plantation was significantly enhanced, and it was able to withstand rainfall event more severe than those with a return period of 100 years, with only minimal deformation. The results suggest that the gain in shear strength due to ryegrass roots surpasses the additional sliding force caused by the increased water retention capability. Additionally, it is found that the abrupt change in pore pressure was no longer indicative of slope failure in the case of the grass-reinforced slope.</p></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"2 4","pages":"Article 100101"},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2949929124000330/pdfft?md5=e559eef248da6ada511b94e9ec23f693&pid=1-s2.0-S2949929124000330-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141691018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of grassland vegetation roots on soil infiltration rate in Xiazangtan super large scale landslide distribution area in the upper reaches of the Yellow River, China","authors":"Peihao Zhang ,&nbsp;Guangyan Xing ,&nbsp;Xiasong Hu ,&nbsp;Changyi Liu ,&nbsp;Xilai Li ,&nbsp;Jimei Zhao ,&nbsp;Jiangtao Fu ,&nbsp;Haijing Lu ,&nbsp;Huatan Li ,&nbsp;Zhe Zhou ,&nbsp;Lei Yue ,&nbsp;Yabin Liu ,&nbsp;Guorong Li ,&nbsp;Haili Zhu","doi":"10.1016/j.bgtech.2024.100104","DOIUrl":"10.1016/j.bgtech.2024.100104","url":null,"abstract":"<div><p>In order to study the infiltration characteristics of grassland soil in the super large scale landslides distribution area in the upper reaches of the Yellow River, this study selected the Xiazangtan super large scale distribution area in Jianzha County as the study area. Through experiments and numerical simulations, plant roots characteristics, soil physical properties and infiltration characteristics of naturally grazed grassland and enclosed grassland with different slope directions were compared and analyzed, and the influence of rainfall on seepage field and stability of the two grassland slopes were discussed. The results show that the highest soil moisture infiltration capacity (FIR) is found on the shady slope of the enclosed grassland (2.25), followed by the sunny slope of the enclosed grassland (1.23) and the shady slope of the naturally grazed grassland (−0.87). Correlation analysis show that soil water content, root dry weight density, total soil porosity, number of forks and root length are positively correlated with infiltration rate (<em>P</em>＜0.05), whereas soil dry density is negatively correlated with infiltration rate (<em>P</em>＜0.05). The results of stepwise regression analyses show that soil water content, total soil porosity, root length and number of forks are the main factors affecting soil infiltration capacity. And the ability of roots to increase soil infiltration by improving soil properties is higher than the effect of roots itself. After 60 min of simulated rainfall, the safety factors of the shady slopes of naturally grazed grassland and enclosed grassland are reduced by 29.56% and 19.63%, respectively, comparing to those before rainfall. Therefore, in this study, the roots play a crucial role in regulating soil infiltration and enhance slope stability by increasing soil water content, soil total porosity and shear strength while decreasing soil dry density. The results of this study provide theoretical evidence and practical guidance for the effective prevention and control of secondary geological disasters such as soil erosion and shallow landslide on the slope of river banks in the study area by using plant ecological measures.</p></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"2 4","pages":"Article 100104"},"PeriodicalIF":0.0,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2949929124000366/pdfft?md5=32eff534fe5d0bbb5e86dc6c67130180&pid=1-s2.0-S2949929124000366-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141953117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Porosity and bedding controls on bio-induced carbonate precipitation and mechanical properties of shale and dolomitic rocks: EICP vs MICP","authors":"Mary C. Ngoma ,&nbsp;Oladoyin Kolawole","doi":"10.1016/j.bgtech.2024.100102","DOIUrl":"10.1016/j.bgtech.2024.100102","url":null,"abstract":"<div><p>Biocementation is an emerging field within geotechnical engineering that focuses on harnessing microbiological activity to enhance the mechanical properties and behavior of rocks. It often relies on microbial-induced carbonate precipitation (MICP) or enzyme-induced carbonate precipitation (EICP) which utilizes biomineralization by promoting the generation of calcium carbonate (CaCO₃) within the pores of geomaterials (rock and soil). However, there is still a lack of knowledge about the effect of porosity and bedding on biocementation in rocks from a mechanistic view. This experimental study investigated the impact of porosity and bedding orientations on the mechanical response of rocks due to biocementations, using two distinct biocementation strategies (MICP and EICP) and characteristically low porosity but interbedded rocks (shale) and more porous but non-bedded (dolostone) rocks. We first conducted biocementation treatments (MICP and EICP) of rock samples over a distinct period and temperature. Subsequently, the rock strength (uniaxial compressive strength, <em>UCS</em>) was measured. Finally, we analyzed the pre- and post-treatment changes in the rock samples to better understand the effect of MICP and EICP biocementations on the mechanical response of the rock samples. The results indicate that biocementations in dolostones can improve the rock mechanical integrity (EICP: +58% <em>UCS</em>; MICP: +25% <em>UCS</em>). In shales, biocementations can either slightly improve (EICP: +1% <em>UCS</em>) or weaken the rock mechanical integrity (MICP: −39% <em>UCS</em>)<em>.</em> Further, results suggest that the major controlling mechanisms of biogeomechanical alterations due to MICP and EICP in rocks can be attributed to the inherent porosity, biocementation type, and bedding orientations, and in few cases the mechanisms can be swelling, osmotic suction, or pore pressurization. The findings in this study provide novel insights into the mechanical responses of rocks due to MICP and EICP biocementations.</p></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"2 4","pages":"Article 100102"},"PeriodicalIF":0.0,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2949929124000342/pdfft?md5=1b0d98ae6537e922cb84f6483aae4130&pid=1-s2.0-S2949929124000342-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141953119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discrete element simulations to predict the response of bio-cemented sands","authors":"Pu Yang ,&nbsp;Edward Kavazanjian ,&nbsp;Narayanan Neithalath","doi":"10.1016/j.bgtech.2024.100119","DOIUrl":"10.1016/j.bgtech.2024.100119","url":null,"abstract":"<div><div>Discrete element method (DEM)-based numerical models in the YADE environment are used to simulate the constitutive response of uncemented and bio-cemented sands to investigate the influence of boundary conditions, loading and testing conditions, and material types. Both the classical DEM model and the pore scale finite volume (PFV)-coupled DEM model are used to simulate the response of saturated uncemented and lightly cemented sands with a rigid wall boundary under both drained and undrained triaxial compression. A DEM model with flexible boundaries created using particle facet (PFacet) elements is used to simulate undrained triaxial compression of moderately cemented sands, including the influence of confining stress. The PFacet-based model is used to predict the transition from barreling failure to shear banding when the confining stress or the cementation degree increases. The classical DEM model with cohesive bonds of uniform strength is also used to successfully simulate the uniaxial compression response of a sand with an extremely high degree of cementation. Finally, this paper presents a particle-packing model consisting of multiple solid phases for cemented sands based on the understanding that not all particle types will have the same cohesive properties. This multiple solid-phase model is a refinement of the classical DEM model that represents the particle physics more realistically, especially for heterogeneous systems. A preliminary parametric study is carried out considering varying cohesive properties and volume fractions for the different solid phases.</div></div>","PeriodicalId":100175,"journal":{"name":"Biogeotechnics","volume":"3 4","pages":"Article 100119"},"PeriodicalIF":0.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141415304","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}