SAE International Journal of Fuels and Lubricants最新文献

{"title":"Blending Carbon Intensity for Ethanol in Gasoline","authors":"Terrence Higgins, Nigel Clark, Tammy Klein, David McKain","doi":"10.4271/04-17-02-0010","DOIUrl":"https://doi.org/10.4271/04-17-02-0010","url":null,"abstract":"<div>Greenhouse gas emissions reduction from the light-duty transportation fleet is urgent and should address both electric and conventional powertrain technologies. Internal combustion engines will continue to be employed for vehicle propulsion and fleet turnover is slow, encouraging reduction of carbon content in gasoline. Currently ethanol, a renewable fuel, is blended at the 10% level into petroleum to produce finished market gasoline. Ethanol enables a less carbon-intensive petroleum blendstock composition, providing for additional reduction, but this is often overlooked in studies. Carbon intensity, as a ratio of CO₂ mass to heat released upon combustion, is a measure of well-to-wheels greenhouse gas production. The well-to-wheels carbon intensity of ethanol does not include its chemical carbon content because it arises from a renewable source, but does consider all upstream farming, production, and transportation carbon impacts. The well-to-wheels carbon intensity of the petroleum fraction includes the chemically bound carbon, as well as production and transportation impact. Carbon intensity modeling results for ethanol vary widely, primarily due to differences in land-use change assessment. The GREET model has gained wide acceptance and provides a present-day carbon intensity for pure ethanol that is 43% lower than for petroleum gasoline. Ethanol exhibits a high blending octane number so that the petroleum component has a lower octane rating than required for purely petroleum gasoline. Fuel trends and modeling suggest that a 10% (by volume) ethanol addition enables a 9% reduction of aromatics, which have a high carbon intensity. If the carbon reduction benefits of the aromatic reduction are assigned to the agency of the ethanol, the blending carbon intensity of ethanol is 56% lower than for petroleum gasoline. Increase in ethanol blending therefore offers substantial immediate climate change reduction.</div>","PeriodicalId":21365,"journal":{"name":"SAE International Journal of Fuels and Lubricants","volume":"27 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136317095","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 Study of High-Pressure Reacting and Non-reacting Sprays for Various Gasoline Blends","authors":"Ankith Ullal, Bastian Lehnert, Shengrong Zhu, Stephan Révidat, Mark Shirley, Kyoung Pyo Ha, Michael Wensing, Johannes Ullrich","doi":"10.4271/04-17-02-0009","DOIUrl":"https://doi.org/10.4271/04-17-02-0009","url":null,"abstract":"<div>Research into efficient internal combustion (IC) engines need to continue as the majority of vehicles will still be powered by IC or hybrid powertrains in the foreseeable future. Recently, lean-burn gasoline compression ignition (GCI) with high-pressure direct injection has been receiving considerable attention among the research community due to its ability to improve thermal efficiency and reduce emissions. To maximize GCI benefits in engine efficiency and emissions tradeoff, co-optimization of the combustion system and fuel formation is required. Thus, it is essential to study the spray characteristics of different fuels under engine-like operating conditions. In this work, high-pressure spray characteristics are experimentally studied for three blends of gasoline, namely, Naphtha, E30, and research octane number (RON) 98. A single-hole custom-built injector was used to inject fuel into a constant volume chamber with injection pressure varying from 40 MPa to 100 MPa. The chamber pressure was varied from 4 MPa to 7 MPa. The spray parameters measured were liquid and vapor penetration, liquid and vapor spray plume angle, and spray and flame luminosity area for reacting and non-reacting sprays. The measurement techniques used were shadowgraphy, Schlieren method, and flame luminosity area measurement. Liquid penetration followed the fuel density pattern and was shortest for Naphtha, followed by RON 98 and E30. The increase in injection pressure did not significantly affect liquid penetration, but improved atomization as well as reduced soot intensity. In addition, vapor penetration was increased on account of higher injection velocity and vaporized mass. The higher chamber pressure drastically reduced liquid and vapor penetration on account of increased drag. Compared to non-reacting sprays, vapor penetration and spray plume angle for reacting sprays deviated according to the fuel type. Ignition of the fuel increased vapor penetration and spray plume angle due to the expansion of hot gases. Naphtha ignited the earliest on account of its low RON and high volatility. It had the highest deviation from the corresponding non-reacting case for vapor penetration. RON 98 fuel only showed a slight increase in vapor plume angle indicating the start of reaction, whereas E30 did not show any deviation.</div>","PeriodicalId":21365,"journal":{"name":"SAE International Journal of Fuels and Lubricants","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135149208","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":"Reviewers","authors":"Nadir Yilmaz","doi":"10.4271/04-16-03-0021","DOIUrl":"https://doi.org/10.4271/04-16-03-0021","url":null,"abstract":"<div>Reviewers</div>","PeriodicalId":21365,"journal":{"name":"SAE International Journal of Fuels and Lubricants","volume":"2674 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135143173","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":"100 Years of Corrosion Testing—Is It Time to Move beyond the ASTM D130? The Wire Corrosion and Conductive Deposit Tests","authors":"Gregory J. Hunt, Lindsey Choo, Timothy Newcomb","doi":"10.4271/04-17-01-0002","DOIUrl":"https://doi.org/10.4271/04-17-01-0002","url":null,"abstract":"&lt;div&gt;The ASTM D130 was first issued in 1922 as a tentative standard for the detection of corrosive sulfur in gasoline. A clean copper strip was immersed in a sample of gasoline for three hours at 50°C with any corrosion or discoloration taken to indicate the presence of corrosive sulfur. Since that time, the method has undergone many revisions and has been applied to many petroleum products. Today, the ASTM D130 standard is the leading method used to determine the corrosiveness of various fuels, lubricants, and other hydrocarbon-based solutions to copper. The end-of-test strips are ranked using the ASTM Copper Strip Corrosion Standard Adjunct, a colored reproduction of copper strips characteristic of various degrees of sulfur-induced tarnish and corrosion, first introduced in 1954. This pragmatic approach to assessing potential corrosion concerns with copper hardware has served various industries well for a century.&lt;/div&gt; &lt;div&gt;Driveline lubricants have always been required to protect hardware, and transmission fluid specifications have always included a version of the copper corrosion strip test to assure this. In conventional transmissions, copper and its alloys are present in the form of mechanical parts such as bushings, bearings, and washers. Corrosion of these parts, while detrimental, does not typically result in immediate failure. However, the incorporation of electronics and electric motors has resulted in new failure modes which can have immediate and devastating consequences. Designing a lubricant to protect new electrified hardware requires an understanding of corrosion that occurs under actual operating temperatures, as well as potential damage from corrosion products. While the ASTM D130 provides general insight regarding the susceptibility of the hardware to corrode, the information is typically gleaned at elevated temperatures, and no information is gathered about the impact of corrosion products. The ASTM D130 is simply not sufficiently specific to adequately assess the risk of these new failure modes that may occur within electric drive units (EDUs). Newer methods, in particular, the wire corrosion test (WCT) and conductive deposit test (CDT), have been created to fill these gaps.&lt;/div&gt; &lt;div&gt;In this article, we provide the history of the creation and evolution of the ASTM D130 standard, which is important in understanding both its significance and limitations. We then assess the corrosion characteristics of five lubricants using both the ASTM D130 strip method and the WCT method. We contrast these results, which demonstrate the greater understanding gleaned from the WCT. We then assess the five lubricants with the CDT, which provides insight into whether the corrosion products might endanger the system. We conclude that both the WCT and CDT are needed to provide a holistic understanding of corrosion in electrified hardware necessary to minimize the risk of corrosion-related failure modes. We anticipate that the WCT and CDT will e","PeriodicalId":21365,"journal":{"name":"SAE International Journal of Fuels and Lubricants","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136098942","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":"Performance of a Diesel Engine Run with Kerosene–Rapeseed Oil Blends\u0000 Doped with Ignition Promoters","authors":"A. Cherepanova, D. Ukhanov, Evgeniy Savel’ev, V. Sapunov","doi":"10.4271/04-17-02-0008","DOIUrl":"https://doi.org/10.4271/04-17-02-0008","url":null,"abstract":"The use of straight vegetable oil in diesel engines leads to undesirable\u0000 consequences due to the peculiar physicochemical properties of vegetable oils.\u0000 In this regard, the use of pure and unmodified vegetable oils requires their\u0000 obligatory dilution with petroleum fuels, usually diesel fuel. However, blends\u0000 of diesel fuel with vegetable oil have a significantly higher density and\u0000 viscosity than pure diesel fuels. Therefore, in this article, it was proposed to\u0000 use blends of vegetable oil with aviation kerosene since kerosene has lower\u0000 density and viscosity compared to diesel fuel. In addition, kerosene is less\u0000 prone to coking of injectors, has a higher calorific value, and has a lighter\u0000 hydrocarbon composition, which makes starting the engine easier. Within the\u0000 framework of the study, engine tests of a full-size four-cylinder diesel engine,\u0000 MMZ D-245.12.C, were carried out at maximum load in the range of crankshaft\u0000 speeds from minimum (1000 min−1) to nominal (2400 min−1).\u0000 Various blends of kerosene with rapeseed oil with an oil content of 10 to 50% by\u0000 volume have been tested. Ignition promoters were introduced into the fuel blends\u0000 to improve their combustion. Commercial ethylhexyl nitrate was used as an\u0000 ignition promoter. In addition, experimental additives were investigated, which\u0000 are the FAMEs of vegetable oils oxidized to various concentrations of peroxide\u0000 compounds. It has been shown that blends of kerosene and rapeseed oil doped with\u0000 ignition promoters can be successfully used in diesel engines. The engine showed\u0000 the maximum power and the lowest level of smoke emissions when running on a\u0000 blend of kerosene and rapeseed oil with the addition of oxidized FAME of olive\u0000 oil with a peroxide content of 1.1 g OOH/100 g.","PeriodicalId":21365,"journal":{"name":"SAE International Journal of Fuels and Lubricants","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48465019","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":"In Situ Assessment of Oil Quality Sensor Performance in Engine\u0000 Lubricant Flow","authors":"Cameron Schepner, Adam Smith, David Schafer, A. Anilkumar","doi":"10.4271/04-17-02-0007","DOIUrl":"https://doi.org/10.4271/04-17-02-0007","url":null,"abstract":"Assessing the functional quality of an engine lubricant through real-time sensing\u0000 could pave the way for development of comprehensive engine health monitoring\u0000 systems. In this study, a permittivity-based, commercial off-the-shelf (COTS)\u0000 oil quality sensor was implemented in the lubricant flow of a diesel engine\u0000 after detailed evaluation on a benchtop test facility. The sensor was mounted on\u0000 the oil filter housing of the engine in the post-filter oil flow, and its\u0000 implementation required no modifications to the engine block. Simultaneously,\u0000 the lubricant flow was visualized by incorporating a novel test cell in the oil\u0000 flow path. Both the sensor assembly and the flow visualization cell were fully\u0000 characterized on the benchtop facility prior to implementation on the engine. In\u0000 these experiments, fresh and used samples of the engine’s recommended oil were\u0000 tested, and the sensor’s oil quality measurements showed noticeable differences\u0000 between the engine and benchtop studies, a feature attributable to the observed\u0000 presence of aeration intrinsic to the engine oil flow. These results prove that\u0000 the adaptation of permittivity-based sensors for effective real-time engine\u0000 lubricant quality monitoring will require comparative assessment of oil quality\u0000 measurements in aerated and nonaerated flow fields.","PeriodicalId":21365,"journal":{"name":"SAE International Journal of Fuels and Lubricants","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48683994","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 Study on Distribution Characteristics and Leakage\u0000 Detection of Hydrogen Release from Hydrogen Supply System of Fuel Cell\u0000 Truck","authors":"Shu Liu, R. He","doi":"10.4271/04-17-01-0006","DOIUrl":"https://doi.org/10.4271/04-17-01-0006","url":null,"abstract":"The hydrogen supply system of a fuel cell truck is in a semi-enclosed space where\u0000 hydrogen is easy to accumulate if a hydrogen leak occurs. The acquisition of\u0000 hydrogen dispersion behavior data is essential to support the detection of\u0000 hydrogen release. The purpose of this article is to present the characteristics\u0000 of hydrogen concentration distribution and delay time of hydrogen leakage\u0000 detection under different leakage parameters. The experiments have been\u0000 performed in a hydrogen storage cabin with six hydrogen sensors arranged on the\u0000 roof to measure hydrogen concentration. During the tests, hydrogen was released\u0000 into the test cabin through standard leaks. Two different release rates (80\u0000 NL/min and 450 NL/min), three different release positions, and six release\u0000 directions are investigated to analyze the effects on the distribution of\u0000 hydrogen concentration and leakage detection delay time. This article presents\u0000 both the experimental facility and results. The experimental results can help\u0000 optimize the placement of hydrogen sensors and the design of a hydrogen leakage\u0000 detection system.","PeriodicalId":21365,"journal":{"name":"SAE International Journal of Fuels and Lubricants","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47794811","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":"Research on the Tribological Properties of Layered Kaolin Lubricant\u0000 Additives","authors":"Yuqin Zhu, Li Zhang, Jian Chang, Xinming Wang, Wei Chai, Shaoze Song","doi":"10.4271/04-17-01-0005","DOIUrl":"https://doi.org/10.4271/04-17-01-0005","url":null,"abstract":"Lubricant additives are the main means to improve the performance of lubricants.\u0000 In this article, green and inexpensive layered kaolin were selected as lubricant\u0000 additives, and the effects of the type of modifier, concentration, particle size\u0000 of kaolin additives, and working temperatures on the tribological performance of\u0000 lubricants were investigated. The results showed that the Span80 modifier can\u0000 effectively improve the dispersibility and friction reduction effects of kaolin\u0000 oil samples. Compared with kaolin oil samples without the modifier, the modified\u0000 kaolin oil can reduce the friction coefficient by 40.9% and the wear spot\u0000 diameter of the steel balls by 43.8%. The layered kaolin additive can\u0000 significantly reduce the friction coefficient and wear of steel balls in\u0000 lubrication, and the friction coefficient showed a trend of decreasing and then\u0000 increasing with increasing kaolin additive concentration and particle size. The\u0000 optimal added concentration and particle size of kaolin are 5 wt% and 2 μm,\u0000 respectively, which can reduce the friction coefficient by 41.9% and 65.63% and\u0000 the wear spot diameter by 12.31% and 50.72%, respectively, compared with the\u0000 base oil. At five temperatures, compared with the base oil, the kaolin oil\u0000 samples all showed better friction reduction and anti-wear properties. The micro\u0000 and nano size of the kaolin additive, the layered structure, and the chemically\u0000 reactive film generated on the surface are the main reasons for its good\u0000 lubrication performance.","PeriodicalId":21365,"journal":{"name":"SAE International Journal of Fuels and Lubricants","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46279470","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":"Numerical Validation and Optical Study of Injection of Different Oxymethylene Ether Fuels for Heavy-Duty Application","authors":"K. Gaukel, D. Pélerin, Patrick Dworschak, M. Härtl, M. Jaensch","doi":"10.4271/04-17-01-0004","DOIUrl":"https://doi.org/10.4271/04-17-01-0004","url":null,"abstract":"A reliable toolchain for the validation and evaluation of numerical spray break-up simulation for the potentially carbon-neutral fuels polyoxymethylene dimethylether (POMDME, or short OME) is developed and presented. The numerical investigation is based on three-dimensional computational fluid dynamics (3D-CFD) with the commercial code STAR-CD v2019.1 using a Reynolds-averaged Navier-Stokes (RANS) equations approach. Fuel properties of the representatives OME1 and OME3 are implemented into the software and with that the fuels are investigated numerically. For validation purposes, optical experimental results in a heated spray chamber with inert nitrogen-pressurized atmosphere are presented. The measurement data are based on Mie scattering of the liquid phase and Schlieren imaging of the vapor phase. Solely experimental results are shown for OME1b and OME3–6 to assess if the knowledge from the numerical modeling with OME1 and OME3 can also be transferred to the corresponding multicomponent fuels. While the results for a match between OME3 and OME3–6 are close, the measurement for OME1b exceeds the result of OME1 in the liquid penetration significantly. This is explained by the molecular structure of the low-volatile additive in OME1b based on long-chained polyglycol ethers. For the numerically modeled operating conditions, the fuel injection rate with the corresponding fuel is measured. Two atomization and spray break-up approaches are investigated in simulation, based on Reitz-Diwakar (RD) models and a combination using Huh’s atomization and the Kelvin-Helmholtz Rayleigh-Taylor (KHRT) spray break-up models. A holistic parameter study in a single operating point with the fuel OME1 helps to determine the sensitivities of the models. Adjustments to the spray momentum by a variation of the parameter for the nozzle hole diameter are used to get results closely aligned with measurement data. The transfer of the calibrated RD model to a validation study with OME3 at different operating conditions matches well to measurement with no further adjustments necessary.","PeriodicalId":21365,"journal":{"name":"SAE International Journal of Fuels and Lubricants","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41871312","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":"Hybrid Electric Vehicle Engine Operation and Engine Oil Degradation: A Research Approach","authors":"David Growney, Arndt Joedicke, Megan Williams, Mathew P Robin, R. Mainwaring, M. Davies","doi":"10.4271/04-17-01-0001","DOIUrl":"https://doi.org/10.4271/04-17-01-0001","url":null,"abstract":"Hybrid electric vehicles (xHEV) are a critical enabler to fulfil the most recent CO and fuel economy requirements in key markets like North America, China, and Europe [1, 2]. Different levels of hybridization exist; the main differentiator is the power of the electric system and battery capacity. Increased electrical power enables the vehicle to run more often in electric mode and recuperate energy from braking, which enhances the saving potential [3]. Mild (MHEV) and plug-in hybrid vehicles (PHEV) impose different duty cycles on the engine compared to a conventional powertrain, potentially altering the degradation mechanisms of the lubricant, and challenging the basis on which the lubricant should be condemned [4]. The biggest concerns are water and fuel dilution [5], which promote corrosion and can form emulsions [6]. This may result in so-called white sludge formation (a thick and creamy emulsion) which can deposit inside the engine on colder surfaces, potentially blocking pipes and breather hoses [6]. White sludge deposits on the oil filler cap can become visible to the vehicle operator and may be a reason for concern. Many original equipment manufacturers (OEMs), and their customers, need advice in defining the important oil parameters for the oil to be fit for purpose. If oil and additive companies are to respond to these challenges, an increased awareness and understanding of oil degradation in modern vehicle platforms is required. In this work, we have investigated the operating conditions in different hybrid vehicles and their impact on the engine oil. First, a chassis dynamometer (CD dyno) test program was conducted to understand how three different concepts influence engine operation, specifically the engine oil temperature and the number of stop/start events. Second, engine dyno testing was designed to replicate a worst-case scenario, extrapolating some of the observations from CD testing, to investigate the effect of an extreme drive cycle on the engine oil degradation and contamination. Finally, an analysis of the chemical and physical properties of these engine test drain oils, and the resulting impact on wear protection and engine cleanliness, was undertaken to understand the risks associated with worst-case scenario xHEV operation.","PeriodicalId":21365,"journal":{"name":"SAE International Journal of Fuels and Lubricants","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45081262","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}