Sebastian Valencia , Andres Mendiburu , Luis Bravo , Prashant Khare , Cesar Celis
{"title":"Flow-field analysis and performance assessment of rotating detonation engines under different number of discrete inlet nozzles","authors":"Sebastian Valencia , Andres Mendiburu , Luis Bravo , Prashant Khare , Cesar Celis","doi":"10.1016/j.jaecs.2024.100296","DOIUrl":"10.1016/j.jaecs.2024.100296","url":null,"abstract":"<div><div>This study explores in depth rotating detonation engines (RDEs) fueled by premixed stoichiometric hydrogen/air mixtures through two-dimensional numerical simulations including a detailed chemical kinetic mechanism. To model the spatial reactant non-uniformities observed in practical RDE combustors, the referred simulations incorporate different numbers of discrete inlet nozzles. The primary focus here is to analyze the influence of reactant non-uniformities on detonation combustion dynamics in RDEs. By systematically varying the number of reactant injection nozzles (from 15 to 240), while maintaining a constant total injection area, the study delves into how this variation influences the behavior of rotating detonation waves (RDWs) and the associated overall flow field structure. The numerical results obtained here reveal significant effects of the number of inlets employed on both RDE stability (self-sustaining detonation wave) and performance. RDE configurations with a lower number of inlets exhibit a detonation front with chaotic behavior (pressure oscillations) due to an increased amount of unburned gas ahead of the detonation wave. This chaotic behavior can lead to the flame extinguishing or decreasing in intensity, ultimately diminishing the engine's overall performance. Conversely, RDE configurations with a higher number of inlets feature smoother detonation propagations without chaotic transients, leading to more stable and reliable performance metrics. This study uses high-fidelity numerical techniques such as adaptive mesh refinement (AMR) and the PeleC compressible reacting flow solver. This comprehensive approach enables a thorough evaluation of critical RDE characteristics including detonation velocity, fuel mass flow rate, impulse, thrust, and reverse pressure waves under varying reactant injection conditions. The insights derived from the numerical simulations carried out here enhance the understanding of the fundamental processes governing the performance of RDE concepts.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"20 ","pages":"Article 100296"},"PeriodicalIF":5.0,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416231","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}
R. Bellini , C. Rodriguez , I.K. Karathanassis , L. Pickett , M. Gavaises , E. Geber
{"title":"Modelling of wall-bounded cavitating flow and spray mixing in multi-component environments using the PC-SAFT equation of state","authors":"R. Bellini , C. Rodriguez , I.K. Karathanassis , L. Pickett , M. Gavaises , E. Geber","doi":"10.1016/j.jaecs.2024.100295","DOIUrl":"10.1016/j.jaecs.2024.100295","url":null,"abstract":"<div><div>This work introduces a numerical multiphase model for multi-component mixtures, utilizing tabulated data for physical and transport properties across a spectrum of conditions from near-vacuum pressures to supercritical states. The property data are derived using Perturbed Chain Statistical Associating Fluid Theory (PC-SAFT), vapor-liquid equilibrium (VLE) calculations, entropy scaling methodologies, and Group Contribution (GC) methods. These techniques accurately reflect the thermodynamic behaviors of real fluids, avoiding the empirical estimation of Equation of State (EoS) input parameters. Implemented in OpenFOAM, the fluid dynamics solver is designed to address the three-dimensional Navier-Stokes equations for multi-component mixtures. The methodology integrates operator splitting to manage hyperbolic and parabolic steps distinctively. Hyperbolic terms are solved using the HLLC (Harten-Lax-van Leer-Contact) solver with temporal integration performed via a third-order Strong-Stability-Preserving Runge–Kutta (SSP-RK3) method. Viscous stress tensor contributions in the momentum equation are handled through an implicit velocity correction equation, while parabolic terms in the energy equation are explicitly solved. The simulation efficiency is further enhanced by adaptive Local Time Stepping and the Immersed Boundary (IB) method, which addresses interactions between the fluid and solid boundaries. Turbulence is resolved using the Wall Adaptive Large Eddy (WALE) model. Applied to high-pressure diesel fuel spray injections into non-reacting (nitrogen) gas environments, the model has been validated against Engine Combustion Network (ECN) data for the Spray-C configuration, featuring a fully cavitating multi-hole orifice. Results demonstrate that the model achieves accurate predictions across a broad range of tested conditions without the need for tuning or calibration parameters.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"20 ","pages":"Article 100295"},"PeriodicalIF":5.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416236","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":"Including detailed chemistry features in the modeling of emerging low-temperature reactive flows: A review on the application to diluted and MILD combustion systems","authors":"Giancarlo Sorrentino , Giovanni Battista Ariemma , Federica Ferraro , Benoit Fiorina","doi":"10.1016/j.jaecs.2024.100291","DOIUrl":"10.1016/j.jaecs.2024.100291","url":null,"abstract":"<div><div>Developing and optimizing new reactive systems with carbon-neutral fuels like biofuels, e-fuel, hydrogen, or ammonia is crucial for sustainable energy. This requires advanced technologies capable of fuel flexibility, high efficiency, and minimal pollutant emissions. However, these energy carriers still produce pollutants, especially NOx. To address this, engineers aim to lower combustion process temperatures by adopting different strategies such as burned gas recirculation, staging or increasing the air-to-fuel ratio. Yet, lean flames, though effective at emission reduction, are prone to instability and extinction, posing safety and mechanical risks. Emerging technologies like MILD Combustion, based on burned gas recirculation and reactant dilutions offer interesting solutions. The review article begins by synthesizing experimental studies and numerical simulations of MILD turbulent combustion. It then explores fundamental phenomena specific to diluted combustion (where MILD regimes are included as sub-sets), including autoignition and flame propagation. Using high-fidelity simulations and advanced experiments, it examines flow and mixing roles in reactive zones stabilization. Moving forward, the review paper addresses the inclusion of detailed chemical properties in modeling turbulent combustion systems. Scientific challenges revolve around modeling the intricate interactions between combustion chemistry and flow turbulence while maintaining computational efficiency compatible with industrial constraints. To address this, various simplified chemistry methods – such as reduced, tabulated, or optimized chemistry – have been developed. Additionally, turbulence/chemistry coupling modeling remains unresolved in simulations, with three main routes – geometrical, statistical, or reactor-based approaches – available for turbulent combustion modeling. The state-of-the-art in simplified chemistry and turbulent combustion modeling for low-temperature regimes is then focused on capturing MILD regimes, where there is a crucial impact of dilution by burnt gases, heat transfer, and turbulence mixing on the chemical flame structure. Recent advancements enabled by machine learning and deep learning algorithms are also highlighted. Lastly, the article underscores the critical need for data to validate models, emphasizing the importance of scale-bridging experiments.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"20 ","pages":"Article 100291"},"PeriodicalIF":5.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416110","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":"Recent progresses in research on liquid ammonia spray and combustion: A review","authors":"Zhenhua An, Jiangkuan Xing, Ryoichi Kurose","doi":"10.1016/j.jaecs.2024.100293","DOIUrl":"10.1016/j.jaecs.2024.100293","url":null,"abstract":"<div><div>As climate change intensifies, the global push for de-carbonization highlights the urgent need for carbon-free fuels. Ammonia (NH<sub>3</sub>), with zero carbon emissions and a notable ability as a hydrogen carrier (17.8 % by weight), has emerged as a promising candidate for a net-zero economy. Over the past decade, substantial research has been devoted to the combustion of gaseous ammonia. However, liquid ammonia has several key advantages over gaseous ammonia, including high energy density, cost efficiency, system simplicity, and a high octane number. Despite these benefits, challenges such as high NOx emissions, low combustion stability, significant latent heat, and susceptibility to flash boiling necessitate further exploration. This article comprehensively reviews the current state of research on liquid ammonia as a fuel, covering experimental and numerical efforts regarding fundamental fuel properties, spray characteristics, flame stabilization, combustion performance, and emissions. By systematically summarizing the recent advancements in liquid ammonia spraying and combustion, this review aims to serve as a cornerstone for future experimental and numerical studies and industrial applications, providing a reference for the research and utilization of liquid ammonia combustion.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"20 ","pages":"Article 100293"},"PeriodicalIF":5.0,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416237","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":"An entrained flow biomass gasification technology with the fluidized bed concept for low-carbon fuel production","authors":"Keigo Matsumoto","doi":"10.1016/j.jaecs.2024.100292","DOIUrl":"10.1016/j.jaecs.2024.100292","url":null,"abstract":"<div><div>For accomplishing the vision of building of a net-emission zero society, low-carbon fuels such as e-fuel, Sustainable Aviation Fuel (SAF), and chemical products generation, plays a significant role. Especially, among the low carbon fuels, SAF is the most crucial. Ammonia and electric aircraft are under way as alternatives to fossil-derived jet fuel (kerosene). However, none of these have yet found their way to commercialization. Among the SAF production technology, biomass gasification and Fischer-Tropsch (FT) synthesis technology are one of the lowest CO<sub>2</sub> emission processes, according to Life Cycle Assessment (LCA) analysis. However, at present there are some issues about biomass grinding, tar, ash treatment, gas purification and wastewater. We, at Mitsubishi Heavy Industries (MHI) R&D laboratory have developed entrained bed gasification, adopting the fluidized bed concept in which biomass particles are recirculated in the gasifier without fluidizer. Principally desired outcomes of this development was to reduce the grinding power, simplify the structure by using atmospheric pressure process, and lower tar concentration while maintain suitable temperature to prevent ash from melting inside gasifier. Empirical and actual results showed that the developed gasifier can obtain high carbon conversion ratio and low tar as compared to the traditional gasification processes for low-carbon fuel production and produce reliably stable syngas for low-carbon fuel synthesis with single gasifier. Based on the pilot plant operation results, effectiveness of moderate (1223 – 1323 K) temperature gasification with this concept has been demonstrated too. As a conclusion, development needs and expectation of gasification technology for contributing to carbon neutral society are mentioned.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"20 ","pages":"Article 100292"},"PeriodicalIF":5.0,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416224","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":"Progress in spontaneous ignition of hydrogen during high-pressure leakage with the considerations of pipeline storage and delivery","authors":"Xin-Yi Liu, Z.Y. Sun, Yao Yi","doi":"10.1016/j.jaecs.2024.100290","DOIUrl":"10.1016/j.jaecs.2024.100290","url":null,"abstract":"<div><div>High-pressure pipeline storage presents a promising method for widespread and efficient hydrogen transfer. However, challenges arise in mitigating pressurized hydrogen leakage due to hydrogen embrittlement issues associated with conventional pipeline materials. Experimental findings indicate that pressurized hydrogen is prone to spontaneous combustion, even at relief pressures as low as approximately 2 MPa - well below the permissible pipeline pressure in most countries. Despite this, there remains a lack of consensus regarding the mechanism of spontaneous ignition from high-pressure hydrogen leakage, and current research in this area is deemed insufficient. This study aims to analyze and discuss the presumed mechanisms of spontaneous ignition comparatively, review the progress in the study of spontaneous ignition of hydrogen in high-pressure leakage based on diffusion ignition theory, and statistically compare and discuss the influences of significant factors existing in pipelines (e.g., macro size factors and internal structure) and/or pipe failures (e.g., rupture factors) on spontaneous ignition. It is hoped that this article will provide scholars involved in the development of hydrogen energy and the theories of spontaneous combustion with a systematic understanding of these phenomena.</div></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"20 ","pages":"Article 100290"},"PeriodicalIF":5.0,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319733","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":"Influence of injector configuration on secondary wave formation and propagation in a rotating detonation combustor","authors":"Michael Ullman, Venkat Raman","doi":"10.1016/j.jaecs.2024.100289","DOIUrl":"10.1016/j.jaecs.2024.100289","url":null,"abstract":"<div><p>Numerous studies of rotating detonation engines (RDEs) have noted the appearance of weaker secondary waves which travel with or counter to the primary wave system. These secondary waves can affect the speed, strength, multiplicity, and directional preference of the primary wave system, all of which have implications for engine performance and operability. As such, understanding the formation and stabilization of different wave modes is critical for developing practical RDE systems. To this end, the present work uses an adaptive mesh refinement framework to simulate two-dimensional unwrapped RDEs at high spatial resolution. Four injection configurations are considered, including a simplified continuous injection boundary, as well as three discrete injection setups with varying injector diameter and spacing. In the discrete injection cases, the effects of mass flow rate and near-wave grid resolution are also investigated. Continuous injection is found to produce a single wave, while discrete injection yields increasing numbers of co- and counter-propagating waves when the number of injectors or the reactant flow rate increases. The generation of secondary waves is linked to acoustic reflections associated with wave passage over the discrete injectors, as well as successive “micro-explosions” that occur when a reaction zone recouples to a shock wave traversing a reactant jet. These secondary waves can then coalesce in the presence of fresh reactants, providing a mechanism for new primary waves to form and the directional preference of the wave system to switch. The diameter and spacing of the injectors directly impact the sustained propagation of the primary waves, as well as the availability of reactants needed to form a strong counter-propagating wave system. The unsteadiness induced by the different injection schemes is manifested in conditional statistics for heat release and heat release rate, which show enhanced deflagrative combustion in discrete injection configurations.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"20 ","pages":"Article 100289"},"PeriodicalIF":5.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666352X2400044X/pdfft?md5=4837dd052aab2f7a604d2cd642df3b2d&pid=1-s2.0-S2666352X2400044X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142272807","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":"Liquid-fueled high-performance burner utilizing a coarse porous matrix","authors":"Daiki Matsugi , Shoma Kawamura , Takuya Yamazaki , Yuji Nakamura","doi":"10.1016/j.jaecs.2024.100287","DOIUrl":"10.1016/j.jaecs.2024.100287","url":null,"abstract":"<div><p>In this study, a kerosene-fueled premixed burner system with a thick and large pore-sized (“coarse”) porous matrix was developed to achieve less-soot stable premixed combustion with variable combustion loads, i.e., turn-down ratio, TDR, defined as the ratio between the maximum and minimum loads. The present burner system mainly consists of the thick and coarse porous matrix made by packed ceramic balls of 8 mm-diameter, which acts as a vaporizer, mixer, and flame holder. The liquid fuel is fed into the porous matrix along with air. As the air and vaporized fuel are supplied toward the top-end (surface) of the porous matrix, a premixed flame is formed at this surface. Benefits of the adopted porous matrix include reduced wettability of the liquid fuel to pores of the porous matrix, which prevents its direct supply to the flame, promotes vaporization and mixing, and functions as a flame holder, allowing the flame to be sustained within the porous matrix. Combustion experiments were then carried out under various equivalence ratios (<em>φ</em>) between 0.47 and 1.34, and temperature measurement was conducted to evaluate the vaporization capability within the porous matrix. The experimental results confirmed that the quasi-steady and stable premixed combustion across the entire surface of the porous matrix throughout the burning event was successfully achieved under all <em>φ</em> values considered in this study. A simplified (one-dimensional) analytical model was developed to examine achievable range of TDR. It was found that the expected achievable TDR was higher than the value for the conventional spray combustion technology (∼ 6). Thus, the present burner system with a thick and coarse porous matrix was effective for attaining stable premixed combustion and a high TDR.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"20 ","pages":"Article 100287"},"PeriodicalIF":5.0,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666352X24000426/pdfft?md5=a4b50d4190acb54bf8bc2d82adc235d8&pid=1-s2.0-S2666352X24000426-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142097624","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":"Perspective article: Mitigating social and economic impact of wildfires","authors":"Louis A.(Lou) Gritzo","doi":"10.1016/j.jaecs.2024.100285","DOIUrl":"10.1016/j.jaecs.2024.100285","url":null,"abstract":"<div><p>Wildfires are a natural part of the earth's ecosystem. Over time, the social and economic consequences have significantly increased as development in or near forested areas (i.e. the wildland/urban interface or WUI) has continued, resulting in more value and lives exposed to wildfire events, and due to increasingly large wildfire prone regions and extended seasons caused by changes in the climate. The most significant events are, by some measures, hardly ‘wildland fires’, they are more massive conflagrations affecting communities of burning homes and businesses. The total area around the world that can reasonably be regarded in ‘high fire risk’ is beyond the level of controlled burns, forest thinning, or one-by-one implementation of defensible spaces around structures and homes. Current policies are not effective at the scale of the problem. Better capabilities are needed to provide key decisionmakers including land use planners, building code officials, and wildland managers the right tools to manage this risk. A well designed and governed public private partnership is required. The combustion research community will be at the core of the development that can make it successful, but they will need to band together to bring their numerous individual skills to the table together.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"20 ","pages":"Article 100285"},"PeriodicalIF":5.0,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666352X24000402/pdfft?md5=697165f5ff4f9cf493ee62a0b043a720&pid=1-s2.0-S2666352X24000402-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142097625","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":"Meeting the challenge of mitigating Li-ion battery fires for aviation","authors":"Paul Papas","doi":"10.1016/j.jaecs.2024.100286","DOIUrl":"10.1016/j.jaecs.2024.100286","url":null,"abstract":"<div><p>The aviation industry faces a pressing challenge in reducing its environmental footprint, especially with the projected growth in global passenger traffic. Electrification and more-electric aircraft, particularly through Lithium-ion Battery (LiB) systems, offers a promising pathway to reduce emissions but introduces significant safety concerns, particularly regarding thermal runaway (TR) events. This prospective paper examines the unique challenges posed by aviation environments for developing safe LiB systems. It discusses multifaceted mitigation approaches, integrating fire containment structures with advanced thermal management and fire protection technologies. Various cooling technologies and fire suppression agents are explored for their effectiveness in extinguishing LiB fires and mitigating thermal runaway propagation. Integrated LiB suppression systems are proposed to combine fire containment, suppression, and thermal management functionalities for achieving the demanding specific energy density levels that will be required. Scaling safe LiB pack solutions for commercial aviation requires coordinated efforts among regulators, original equipment manufacturers (OEMs), engineers, and researchers to establish standardized design criteria, develop validated modeling tools, and establish rigorous certification testing requirements. In conclusion, addressing the safety concerns of large LiB packs in aircraft applications requires a holistic, integrated approach. This paper provides insights into current research, identifies key challenges, and outlines future directions for advancing LiB safety in aviation.</p></div>","PeriodicalId":100104,"journal":{"name":"Applications in Energy and Combustion Science","volume":"20 ","pages":"Article 100286"},"PeriodicalIF":5.0,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666352X24000414/pdfft?md5=25ea528ad709b1dd6f2277a438eae6f5&pid=1-s2.0-S2666352X24000414-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142137070","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}