Volume 7: Industrial and Cogeneration; Manufacturing Materials and Metallurgy; Microturbines, Turbochargers, and Small Turbomachines; Oil & Gas Applications最新文献

{"title":"Towards Fast Prediction of Flame Stability and Emissions of mGT Combustion Chambers: a Chemical Reactor Network Approach","authors":"Matteo Savarese, J. Bompas, W. De Paepe, A. Parente","doi":"10.1115/gt2022-81963","DOIUrl":"https://doi.org/10.1115/gt2022-81963","url":null,"abstract":"\u0000 Hydrogen as energy carrier, in combination with dry, low-NOx micro gas turbines (mGTs), is receiving increasing attention, since it can represent an attractive solution for a low-carbon, highly efficient and decentralized energy restitution system. However, accommodating hydrogen-enriched fuel blends in already existing combustion technologies is not an easy task, due to the increased reactivity of this fuel and the higher associated NOx emission. In this framework, reliable numerical models are needed to assist the industry towards the re-design of existing combustion assets. In particular, predicting thermal efficiency and pollutant emissions is of crucial importance for assessing the performances of a given system, since energy production facilities will have to cope with more stringent regulations. Alternative, physics-based modeling tools, such as Chemical Reactor Networks (CRNs), can represent an appealing solution for fast and reliable predictions of overall combustion efficiency and pollutants emissions. This tool allows to represent complex reactive flow fields as a series of idealized reactor models, thus drastically reducing the computational cost of the simulations. For this reason, detailed kinetic schemes can be employed. Detailed chemistry is crucial for reliable pollutants predictions, especially for NOx and CO, since the formation of those chemical species follows complex chemical pathways. The use of CRNs is quite frequent in literature, especially for performing parametric studies for gas turbines applications. The design of an equivalent CRN for a given combustor is based on the manual observation of the main flow-field features, which can be obtained from experiments or CFD data. The aim of this paper is to construct a highly simplified CRN of a typical mGT, Turbec T100 combustor, in order to perform design exploration studies. The effect of the main operating parameters, such as equivalence ratio, air inlet temperature and fuel composition was studied. Moreover, part load conditions were also simulated. Results highlighted that hydrogen addition does not systematically leads to increased pollutants emissions, since due to its higher reactivity, it offers the possibility to operate in leaner conditions, with respect to natural gas. The obtained results aim at providing useful guidelines for further experimental or detailed numerical design explorations for identified interesting conditions.","PeriodicalId":301910,"journal":{"name":"Volume 7: Industrial and Cogeneration; Manufacturing Materials and Metallurgy; Microturbines, Turbochargers, and Small Turbomachines; Oil & Gas Applications","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122049567","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":"Abradable Seal Test Rig for Quantifying Abradable Material Performance During Labyrinth Seal Rubs in Centrifugal Compressors: Design and Test Results","authors":"Kelsi M. Katcher, Thomas Revak, Aaron M. Rimpel, Jeffrey Ratay, K. Brun","doi":"10.1115/gt2022-81797","DOIUrl":"https://doi.org/10.1115/gt2022-81797","url":null,"abstract":"\u0000 In centrifugal compressors, the shaft seal clearance is critical to equipment efficiency and performance. Applications employing very small seal clearances must rely on abradable materials in the stator (housing) to prevent damage to rotating components in the case of rubs. An interaction (or rub) between the rotating seal geometry and stationary seal material can occur while traversing critical speeds or during upset conditions or transients outside the normal, designed operating range of the compressor such as thermal transients or excessive vibrations. The standard abradable seal material for compressor applications is mica-filled PTFE, but alternative materials are required in applications with elevated temperatures, elevated pressures, or harsh environments where chemical resistance is necessary. The behavior of these various abradable materials during a rub event is not well understood and needs to be further quantified to allow for proper material selection for each compressor design.\u0000 In order to determine suitable alternative materials, a rub simulation test rig was developed to quantify the material wear characteristics and thermal stability of various seal samples. The test rig was designed with a 7.24-inch (184-mm) diameter rotating section with representative labyrinth seal teeth. The rotating shaft was coupled with a variable speed motor capable of operating up to 24,000 rpm, allowing for surface speeds up to 754 ft/s. A 180-degree abradable seal section was mounted concentric to the rotating shaft, which may be forced into the rotating seal teeth by a linear actuator to simulate the rub. The test rig was designed to accommodate various interaction rates, initially considering 0.1 and 1 mil/s (2.54 and 25.4 μm/s) to simulate a rub caused by thermal growth and a rub caused by vibration or bow, respectively. Furthermore, the test rig was equipped with an ambient heater and pressure enclosure to evaluate seal materials at elevated temperatures and with various gas compositions. This paper presents the design and capabilities of the abradable seal test rig as well as the initial rub test results for Fluorosint 500.","PeriodicalId":301910,"journal":{"name":"Volume 7: Industrial and Cogeneration; Manufacturing Materials and Metallurgy; Microturbines, Turbochargers, and Small Turbomachines; Oil & Gas Applications","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117184446","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":"Experimental Hydraulic Performance Study of a Primary Surface Recuperator With Cross-Wavy Microchannels for Portable Microturbines","authors":"Haiyang Li, Z. Zou, Yiming Chen, Huanyu Li, Chao Fu","doi":"10.1115/gt2022-80808","DOIUrl":"https://doi.org/10.1115/gt2022-80808","url":null,"abstract":"\u0000 Portable microturbines with high power and energy densities are attractive candidates for mobile power sources. Due to the limitations of compressor pressure ratio and turbine inlet temperature, a compact and lightweight recuperator is the mandatory component of this type of microturbines to achieve high thermal efficiency. Typically, microchannels with thin wall thickness are used for heat transfer enhancement. However, the reduction in channel size may significantly increase the pressure drop of both fluids. Owing to the lack of existing experimental data for ultra-compact microchannel recuperators of portable microturbines, the hydraulic performance of a newly-designed primary surface recuperator with cross-wavy microchannels (CW-PSR) was experimentally studied. The 50 μm-thick heat transfer plates were used for the CW-PSR core, in which the hydraulic diameters of gas and air channels are 848.8 μm and 598.6 μm, respectively. Hence, the surface compactness of the CW-PSR prototype is about 2428 m2/m3. We tested the hydraulic performance of the CW-PSR both under hot and cold conditions with Reynolds numbers ranging from 320 to 980. The experimental results show that the pressure drops on both sides increase with increasing mass flow rate, while the hot conditions with high inlet temperature result in larger pressure drops. Besides, it was confirmed that the friction pressure drop in the heat transfer region accounts for more than 60% of the total pressure drop. Finally, a new correlation of friction factors for cross-wavy microchannels was obtained based on experimental results.","PeriodicalId":301910,"journal":{"name":"Volume 7: Industrial and Cogeneration; Manufacturing Materials and Metallurgy; Microturbines, Turbochargers, and Small Turbomachines; Oil & Gas Applications","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133377134","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":"Creep Analysis and Microstructural Evaluation of a Novel Additively Manufactured Nickel-Base Superalloy (ABD®-900AM)","authors":"Alex Bridges, J. Shingledecker, J. Clark, D. Crudden","doi":"10.1115/gt2022-82512","DOIUrl":"https://doi.org/10.1115/gt2022-82512","url":null,"abstract":"\u0000 Nickel-base superalloys containing 30 to 50% gamma prime (γ′) volume fraction are typically used in hot section components (e.g. guide vanes or blades) for power generating gas turbines, and suitable time dependent properties are required for long-term elevated temperature operation. Additive manufacturing (AM) has recently been used to develop complex hot-section parts utilizing innovative designs with enhanced cooling features which improve efficiencies by reducing cooling air consumption.\u0000 To further explore the opportunity to improve time-dependent AM superalloys, this paper focuses on a fundamental creep study and characterization of a novel nickel-base superalloy (ABD®-900AM) that was manufactured using a laser-based powder bed fusion AM process. The material was subjected to a sub-solvus solution anneal and multi-step aging heat-treatment to produce a bi-modal distribution with ∼35% volume fraction of gamma prime without post-processing hot isostatic pressing (HIP). Microstructural characterization was carried out for the as-built and fully heat-treated structures, and a creep-rupture test program was conducted to study the resultant creep properties. Activation energies and stress exponents in addition to rupture strength and deformation resistance, were compared to traditionally cast IN939 and IN738 materials. After testing, specimens were evaluated using a variety of microscopy tools to determine location and features associated with creep damage.\u0000 The optimized chemistry for ABD®-900AM was printed crack free and fully dense in contrast to studies on similar alloys where significant process development and post-build heat-treatments were required. High-temperature mechanical properties in the heat-treated material showed some decrease in creep strength when compared to traditional casting. This strength and rupture life debit was dependent on build orientation, but a considerable increase in creep ductility was observed due to differences in the microstructure when compared with similar AM alloys. Analysis of creep data showed differences in creep mechanisms compared to traditional cast alloys. The relationship between microstructure and creep mechanisms is discussed, and ongoing work to further improve rupture strength through heat-treatment optimization will be highlighted.","PeriodicalId":301910,"journal":{"name":"Volume 7: Industrial and Cogeneration; Manufacturing Materials and Metallurgy; Microturbines, Turbochargers, and Small Turbomachines; Oil & Gas Applications","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131764768","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":"Statistical Rule Extraction for Gas Turbine Trip Prediction","authors":"G. Bechini, E. Losi, L. Manservigi, G. Pagliarini, G. Sciavicco, Eduard Ionel Stan, M. Venturini","doi":"10.1115/gt2022-82915","DOIUrl":"https://doi.org/10.1115/gt2022-82915","url":null,"abstract":"\u0000 Gas turbine trip is an operational event that arises when undesirable operating conditions are approached or exceeded, and predicting its onset is a largely unexplored area. The application of novel artificial intelligence methods to this problem is interesting both from the computer science and the engineering point of view, and the results may be relevant in both the academia and the industry. In this paper we consider data gathered from a fleet of Siemens industrial gas turbines in operation that include several thermodynamic variables observed during a long period of operation. To assess the possibility of predicting trip events, we first apply a new, systematic statistical analysis to identify the most important variables, then we use a novel machine learning technique known as temporal decision tree, which differ from canonical decision tree because it allows a native treatment of the temporal component, and has an elegant logical interpretation that eases the post-hoc validation of the results. Finally, we use the learned models to extract statistical rules. As a result, we are able to select the 5 most informative variables, build a predictive model with an average accuracy of 73%, and extract several rules. To our knowledge, this is the first attempt to use such an approach not only in the gas turbine field, but also in the whole industry domain.","PeriodicalId":301910,"journal":{"name":"Volume 7: Industrial and Cogeneration; Manufacturing Materials and Metallurgy; Microturbines, Turbochargers, and Small Turbomachines; Oil & Gas Applications","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130030389","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":"Multilayered Fibre-Matrix Interphases Derived From the Electrophoretic Deposition of Ceramic Nano-Powders","authors":"T. Robertson, Xiao Huang, R. Kearsey","doi":"10.1115/gt2022-81166","DOIUrl":"https://doi.org/10.1115/gt2022-81166","url":null,"abstract":"\u0000 A significant challenge within the manufacturing of Ceramic Matrix Composites (CMCs) is the creation of the fibre-matrix interphase which enables the damage tolerant behavior of CMCs. Chemical vapour deposition (CVD) has been a highly successful approach for fabricating fibre-matrix interphases; however, CVD requires capital intensive facilities and hazardous precursors. This work examines electrophoretic deposition (EPD) as an alternative route for the production of fibre-matrix interphases. Four multilayered fibre-matrix interphases (SiC/Al2O3, BN/ZrO2, ZrC/85wt%Al2O3-15wt%ZrO2, and SiC/Si3N4/SiC) were produced through multi-staged electrophoretic deposition of ceramic nano-powders upon SiC fibre bundles. A 25-2 factorial design of experiments is utilized to explore the effect of different levels of the following variables: electric field strength, duration, surfactant, solids loading and binder. Following deposition of the fibre-matrix interphase the fibre bundles are thinly coated with a SiC matrix through a reactive melt infiltration technique. The resultant microcomposites are then subjected to tensile loading until failure to determine which coating and deposition combination are the most likely to yield favorable tensile properties. Additional microscopy is performed to determine the uniformity and thickness of the coatings. The results are then examined to evaluate the suitability of electrophoretic deposition as a production technique for fibre-matrix interphase coatings in CMCs.","PeriodicalId":301910,"journal":{"name":"Volume 7: Industrial and Cogeneration; Manufacturing Materials and Metallurgy; Microturbines, Turbochargers, and Small Turbomachines; Oil & Gas Applications","volume":"179 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122351758","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":"Recrystallization of René N4 and N5","authors":"H. van Esch, Stijn Pietersen, Alex Bridges, J. Scheibel, R. Zuber, W. Greaves","doi":"10.1115/gt2022-81438","DOIUrl":"https://doi.org/10.1115/gt2022-81438","url":null,"abstract":"\u0000 Recrystallization of equiaxed, directionally solidified and single crystal cast nickel base superalloys can occur during some of the manufacturing and repair processes. While equiaxed, and to a lesser extent, directionally solidified cast nickel-based superalloys have grain boundary strengthening this is nonexistent for single crystal superalloys. Therefore, it is especially important to avoid or limit recrystallization during manufacture and repair of these nickel base single crystal gas turbine components.\u0000 This study performed by TEServices, EPRI, MD&A and Sulzer concerns the effect of recrystallization when compressive stresses are introduced during manufacturing and repair processes (grit cleaning and shot peening) when followed by (full solution, partial solution and stress relieve) heat treatments. The objective of this paper is to obtain a better understanding the recrystallization behavior of two single crystal superalloys, René N4 and N5, during the repair processes (grit cleaning, shot peening and heat treatments) and determine how to minimize the depth of recrystallization. The impact of recrystallization on mechanical strength (stress rupture and fatigue) on René N4 material was limitedly tested.\u0000 This study concludes that for both single crystal alloys, René N4 and N5, the less compressive stresses that are introduced during manufacturing and repair, and the lower temperature of exposure during follow up heat treatments, results in a lower recrystallization layer depth.","PeriodicalId":301910,"journal":{"name":"Volume 7: Industrial and Cogeneration; Manufacturing Materials and Metallurgy; Microturbines, Turbochargers, and Small Turbomachines; Oil & Gas Applications","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114487607","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":"Compression Applications for Carbon Reduction","authors":"R. Kurz, Matt Lubomirsky, Greg McLorg","doi":"10.1115/gt2022-80080","DOIUrl":"https://doi.org/10.1115/gt2022-80080","url":null,"abstract":"\u0000 A In the context of carbon reduction efforts, discussions evolve around hydrogen compression, as well as compression requirements related to CO2 capture, transportation and sequestration. In this paper, compression requirements for these applications are discussed.\u0000 The use and creation of hydrogen imposes specific questions on the use of centrifugal compressors. These questions involve the requirement to compress hydrogen for significant pressure ratios, and the impact of transporting hydrogen in pipelines, or by other means. Part of the discussion is also the location of blue hydrogen production versus green hydrogen production, based on the fact that transport of CO2 or natural gas requires less energy than the transport of hydrogen.\u0000 Further, carbon sequestration by capturing, transporting and sequestering CO2 from the exhaust of fossil fired power plants, from the generation of blue hydrogen, or the generation of Ammonia is discussed. Compression duties include the compression from capture pressure to pipeline pressure, the boost compression as part of the pipeline transport, and the compression required to sequester the CO2. Issues addressed in this part include the relative effort required based on the CO2 concentration in the exhaust, and methods to compress CO2 and CO2 mixtures from close to atmospheric pressure to pipeline pressure.\u0000 In this discussion, the option of transporting hydrogen to a power plant versus transporting natural gas to said power plant, and transporting captured CO2 back to a sequestration site, is evaluated, and the conclusion is supported with data.","PeriodicalId":301910,"journal":{"name":"Volume 7: Industrial and Cogeneration; Manufacturing Materials and Metallurgy; Microturbines, Turbochargers, and Small Turbomachines; Oil & Gas Applications","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126116713","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":"Design and Development of a Fast Response Torque Meter for Unsteady Flows in Turbocharger Applications","authors":"Aakeen Parikh, Gunin Singh, C. Noon, H. Flora, R. Martinez-Botas","doi":"10.1115/gt2022-81976","DOIUrl":"https://doi.org/10.1115/gt2022-81976","url":null,"abstract":"\u0000 A high-speed torque meter has been designed and tested for turbocharger applications in order to assess the effect of unsteady boundary conditions. The torque meter is designed using the shaft-twist method by measuring the change in relative angle between the two ends of the drive shaft. Two encoder wheels are mounted on either end of the shaft and a high-speed FPGA measures the variation of time between edges from optical switches. The angular twist in the shaft is calibrated against a reference torque transducer over a range of torque values. The torque meter is installed on an existing compressor rig testing facility at Imperial College London equipped with a pulse generator capable of producing different pulse frequencies and amplitudes. To test the response to unsteady conditions, a centrifugal compressor is driven under a pulsating backpressure while torque is measured at the drive shaft. The torque measurement is compared against static pressure measurements corresponding to the pulsating conditions. Twelve combinations of frequency and pulse amplitudes have been tested. Due to its simple construction and development, the authors believe that where high-speed measurement equipment is already in place, effective torque measurements of this kind can be added with a low cost to help explore unsteady performance in turbomachinery.","PeriodicalId":301910,"journal":{"name":"Volume 7: Industrial and Cogeneration; Manufacturing Materials and Metallurgy; Microturbines, Turbochargers, and Small Turbomachines; Oil & Gas Applications","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116940046","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":"The Development of Turboexpander-Generators for Gas Pressure Letdown Part 3: Design Validation","authors":"O. Najeeb, Rasish Khatri, L. Zheng, Jeremy Liu","doi":"10.1115/gt2022-82293","DOIUrl":"https://doi.org/10.1115/gt2022-82293","url":null,"abstract":"\u0000 This paper is a follow-up to GT2021-60125 (“Design and Analysis”) and GT2021-60317 (“Economic Analysis”), which collectively covered the design, analysis, and economics of innovative Turboexpander Generators (TEG) used in pressure letdown (PLD) applications. This paper describes the testing data of a family of TEGs, 280 kW and 125 kW, for natural gas pressure letdown applications. The TEGs are supported by active magnetic bearings (AMB). Machine design for the two TEGs is very similar for ease of manufacturing and control system design, with wheel design being the primary difference. A comprehensive controls analysis and AMB closed-loop dynamics study were presented earlier. This paper compares predicted and measured transfer functions along with the pre and post brush seals installation data. Drop testing results on the touchdown bearing are shown along with the full-speed touch-down events. Active front-end variable speed drive (VSD) design is presented along with the power generation results. Finally, measured force vs deflection data is presented for a tolerance ring, used as the resilient element for the touchdown bearings.","PeriodicalId":301910,"journal":{"name":"Volume 7: Industrial and Cogeneration; Manufacturing Materials and Metallurgy; Microturbines, Turbochargers, and Small Turbomachines; Oil & Gas Applications","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123956616","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}