A. Jemcov, Joseph Gonzales, J. Maruszewski, Ryan Kelly
A novel non-iterative (explicit) formulation of generalized wall functions that applies to equilibrium and non-equilibrium boundary layer flows was proposed. The proposed formulation uses a set of variables that are more useful for computational fluid dynamics codes as they allow for calculating wall shear stress without an iterative procedure. In addition, an explicit form of the formulation was provided that applies to wall models with and without pressure gradients. The new variable transformation casts the generalizedwall function into a new form that simplifies the implementation and evaluation of wall-shear stress in computational codes.
{"title":"Non-iterative wall model formula for non-equilibrium boundary layer flows","authors":"A. Jemcov, Joseph Gonzales, J. Maruszewski, Ryan Kelly","doi":"10.5937/fme2201223j","DOIUrl":"https://doi.org/10.5937/fme2201223j","url":null,"abstract":"A novel non-iterative (explicit) formulation of generalized wall functions that applies to equilibrium and non-equilibrium boundary layer flows was proposed. The proposed formulation uses a set of variables that are more useful for computational fluid dynamics codes as they allow for calculating wall shear stress without an iterative procedure. In addition, an explicit form of the formulation was provided that applies to wall models with and without pressure gradients. The new variable transformation casts the generalizedwall function into a new form that simplifies the implementation and evaluation of wall-shear stress in computational codes.","PeriodicalId":12218,"journal":{"name":"FME Transactions","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89226136","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}
G. Globočki-Lakić, B. Sredanović, G. Jotić, S. Gotovac
This paper analyses the influence of machining strategies and cutting parameters on the milling of aluminium complex geometry parts. In the first experimental phase, parts were machined with a combination of two roughing strategies and three finishing strategies, with recommended machining parameters. The machining time, machining surface roughness, and the surface geometric accuracy were measured. In the second phase, a new sample was machined with corrected cutting parameters using the best strategy adopted from the first phase. The results have shown that the selection of machining strategy and cutting parameters significantly affects the productivity, quality, and accuracy when machining complex geometry parts.
{"title":"A comparative analysis of milling strategies of complex geometry surfaces","authors":"G. Globočki-Lakić, B. Sredanović, G. Jotić, S. Gotovac","doi":"10.5937/fme2204623g","DOIUrl":"https://doi.org/10.5937/fme2204623g","url":null,"abstract":"This paper analyses the influence of machining strategies and cutting parameters on the milling of aluminium complex geometry parts. In the first experimental phase, parts were machined with a combination of two roughing strategies and three finishing strategies, with recommended machining parameters. The machining time, machining surface roughness, and the surface geometric accuracy were measured. In the second phase, a new sample was machined with corrected cutting parameters using the best strategy adopted from the first phase. The results have shown that the selection of machining strategy and cutting parameters significantly affects the productivity, quality, and accuracy when machining complex geometry parts.","PeriodicalId":12218,"journal":{"name":"FME Transactions","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75827058","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}
The unstretched flame speed of the premixed propane-methanol/ air flames has been studied experimentally in a constant volume combustion chamber with central ignition. The experiments were done at atmospheric pressure and stoichiometric air/fuel ratio. Various blending ratios of methanol (0%, 20%, 40%, 60%, 80%, 100%) by volume, and different elevated initial temperatures (348 K, 373 K, and 398 K) were used in this study. In general, the results indicated that the unstretched flame speed increased with increasing both methanol blending ratio and initial temperature. For M60 the increment value of unstretched flame speed at Ti=398K was about 9% compared with that of pure propane and by elevating the initial temperature for the same blend ratio (M60) from 348 K to 398 K the increment value was about 8.8%. It is also noticed that Markstein length decreased with increasing both initial temperature and blending ratio, which is indicate that flame instability increased with increasing these parameters.
{"title":"Effect of propane-methanol blending ratio on the stretched and unstretched flame speeds at elevated initial temperatures","authors":"A. Abdulraheem, Adel A. M. Saleh, H. Shahad","doi":"10.5937/fme2201121a","DOIUrl":"https://doi.org/10.5937/fme2201121a","url":null,"abstract":"The unstretched flame speed of the premixed propane-methanol/ air flames has been studied experimentally in a constant volume combustion chamber with central ignition. The experiments were done at atmospheric pressure and stoichiometric air/fuel ratio. Various blending ratios of methanol (0%, 20%, 40%, 60%, 80%, 100%) by volume, and different elevated initial temperatures (348 K, 373 K, and 398 K) were used in this study. In general, the results indicated that the unstretched flame speed increased with increasing both methanol blending ratio and initial temperature. For M60 the increment value of unstretched flame speed at Ti=398K was about 9% compared with that of pure propane and by elevating the initial temperature for the same blend ratio (M60) from 348 K to 398 K the increment value was about 8.8%. It is also noticed that Markstein length decreased with increasing both initial temperature and blending ratio, which is indicate that flame instability increased with increasing these parameters.","PeriodicalId":12218,"journal":{"name":"FME Transactions","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78233124","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}
This article presents the results of an experimental investigation of different nanoforms of graphene used as a nano additive in engine lubricating oil. The experiments were carried out on a pin-on-disc tribometer at the Department of Internal Combustion Engines and Propulsions at Széchenyi István University. The paper introduces the experimental equipment and the experimental method and presents the research findings. The paper concludes that fullerene can decrease friction by 7% on average when used as a nano additive in engine lubricating oil. Furthermore, fullerene did not present a sedimentation problem when used as an additive up to 0.25 wt% in lubricant instead of graphene and multiwalled carbon nanotubes. The paper attempts to explain the friction decreasing effect and the possible roles of carbon nano additives in tribological systems.
{"title":"Experimental investigation of the friction modifying effects of different nanoforms of graphene additives in engine lubricating oil","authors":"C. Tóth-Nagy, A. Szabó","doi":"10.5937/fme2201248t","DOIUrl":"https://doi.org/10.5937/fme2201248t","url":null,"abstract":"This article presents the results of an experimental investigation of different nanoforms of graphene used as a nano additive in engine lubricating oil. The experiments were carried out on a pin-on-disc tribometer at the Department of Internal Combustion Engines and Propulsions at Széchenyi István University. The paper introduces the experimental equipment and the experimental method and presents the research findings. The paper concludes that fullerene can decrease friction by 7% on average when used as a nano additive in engine lubricating oil. Furthermore, fullerene did not present a sedimentation problem when used as an additive up to 0.25 wt% in lubricant instead of graphene and multiwalled carbon nanotubes. The paper attempts to explain the friction decreasing effect and the possible roles of carbon nano additives in tribological systems.","PeriodicalId":12218,"journal":{"name":"FME Transactions","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77427663","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}
In this study, machinability tests were carried out to investigate the effects of control factors (cutting tool geometry, cutting speed, and feed rate) on the surface roughness (Ra), deviation from dimensional accuracy (Da_dev), roundness error (Re) in drilling CFRP/Ti6Al4V mixed metallic stack and to determine the optimum levels of drilling parameters. The effects of each control factor and their interactions on three quality characteristics were analyzed, and their levels were single-objectively optimized for each component material by the Taguchi method. The material has components (CFRP and Ti6Al4V) with essentially different properties (mechanical, physical, machinability). Single-objective optimization has limited usability as the drilling must be performed in one through both layers. Therefore, in an additional step, the optimum levels of the control factors were determined by optimizing multi-objective with the Additive Ratio Assessment (ARAS) method. Higher Ra, Da_dev, and Re values were obtained on the CFRP component compared to the Ti6Al4V component. The CFRP/Ti6Al4V stack should be drilled with a nano fire coated carbide drill (T3) at medium cutting speed and high feed rate to achieve minimum Ra, Da_dev, and Re values in one go.
{"title":"Evaluation and multi-criteria optimization of surface roughness, deviation from dimensional accuracy and roundness error in drilling CFRP/Ti6Al4 stacks","authors":"A. Motorcu, E. Ekici","doi":"10.5937/fme2203441m","DOIUrl":"https://doi.org/10.5937/fme2203441m","url":null,"abstract":"In this study, machinability tests were carried out to investigate the effects of control factors (cutting tool geometry, cutting speed, and feed rate) on the surface roughness (Ra), deviation from dimensional accuracy (Da_dev), roundness error (Re) in drilling CFRP/Ti6Al4V mixed metallic stack and to determine the optimum levels of drilling parameters. The effects of each control factor and their interactions on three quality characteristics were analyzed, and their levels were single-objectively optimized for each component material by the Taguchi method. The material has components (CFRP and Ti6Al4V) with essentially different properties (mechanical, physical, machinability). Single-objective optimization has limited usability as the drilling must be performed in one through both layers. Therefore, in an additional step, the optimum levels of the control factors were determined by optimizing multi-objective with the Additive Ratio Assessment (ARAS) method. Higher Ra, Da_dev, and Re values were obtained on the CFRP component compared to the Ti6Al4V component. The CFRP/Ti6Al4V stack should be drilled with a nano fire coated carbide drill (T3) at medium cutting speed and high feed rate to achieve minimum Ra, Da_dev, and Re values in one go.","PeriodicalId":12218,"journal":{"name":"FME Transactions","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83148827","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}
Different brake pad materials are produced, each with their unique composition in the recent past, yet performing the same task and claiming to be better than others. The article provides references for different automotive brake pads subjected to various operating conditions. The present investigation develops an analytical approach for estimating COF and contact radius for different disc-brake pads, which can be used to design an efficient automotive brake pad-disc system under the given load and rotational speed. The coefficient of friction at the pad-disc interface is investigated considering Greenwood Williamson (GW) model and developed novel friction test rig. A MATLAB program along with FFT was developed to simulate the surface topography of the contact interface during the braking process aiding the estimation of contact radius. Surface topography of tested brake pads has been analyzed using an infinite-focus-microscope to verify contact radius. At last, the reference is verified by an experimental investigation using a developed test rig and considering operating parameters.
{"title":"Investigation of coefficient of friction at the interface of automobile brake pads using Greenwood-Williamson contact model and novel test rig","authors":"Mrunal P. Kshirsagar, H. Khairnar","doi":"10.5937/fme2203561k","DOIUrl":"https://doi.org/10.5937/fme2203561k","url":null,"abstract":"Different brake pad materials are produced, each with their unique composition in the recent past, yet performing the same task and claiming to be better than others. The article provides references for different automotive brake pads subjected to various operating conditions. The present investigation develops an analytical approach for estimating COF and contact radius for different disc-brake pads, which can be used to design an efficient automotive brake pad-disc system under the given load and rotational speed. The coefficient of friction at the pad-disc interface is investigated considering Greenwood Williamson (GW) model and developed novel friction test rig. A MATLAB program along with FFT was developed to simulate the surface topography of the contact interface during the braking process aiding the estimation of contact radius. Surface topography of tested brake pads has been analyzed using an infinite-focus-microscope to verify contact radius. At last, the reference is verified by an experimental investigation using a developed test rig and considering operating parameters.","PeriodicalId":12218,"journal":{"name":"FME Transactions","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80911641","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}
A. Balyasnikov, A. Gritsenko, V. Shepelev, B. Kaliyev, N. Kostyuchenkov, O. Fadina
Type Diagnosing and detecting malfunctions in internal combustion engines (ICE) is not an easy task due to their complex design. Timely and high-quality ICE monitoring allows performance to be maintained and prevents breakdowns. Vibration and acoustic analysis is a powerful and informative tool for detecting faults even at an early stage. This article considers a method for determining the main malfunctions of the valvetrain (VT) (tightness of the "valve-seat" interface, thermal gap in the valve drive, valve opening and closing phases) by measuring and analyzing vibroacoustic pulses caused by the operation of individual engine elements. The maximum amplitude and the moment of vibration impulses are used as signal parameters. For the reference signal of the piston, the top dead center (TDC) of the cylinder under study, a vibration pulse from the impact of the piston on an elastic tip placed in the combustion chamber is taken. This technique makes it possible to exclude the external influences and inaccuracies associated with a change in the geometry ICE elements.
{"title":"The development of methodological techniques and an algorithm for diagnosing modern intake systems for internal combustion engines","authors":"A. Balyasnikov, A. Gritsenko, V. Shepelev, B. Kaliyev, N. Kostyuchenkov, O. Fadina","doi":"10.5937/fme2201302b","DOIUrl":"https://doi.org/10.5937/fme2201302b","url":null,"abstract":"Type Diagnosing and detecting malfunctions in internal combustion engines (ICE) is not an easy task due to their complex design. Timely and high-quality ICE monitoring allows performance to be maintained and prevents breakdowns. Vibration and acoustic analysis is a powerful and informative tool for detecting faults even at an early stage. This article considers a method for determining the main malfunctions of the valvetrain (VT) (tightness of the \"valve-seat\" interface, thermal gap in the valve drive, valve opening and closing phases) by measuring and analyzing vibroacoustic pulses caused by the operation of individual engine elements. The maximum amplitude and the moment of vibration impulses are used as signal parameters. For the reference signal of the piston, the top dead center (TDC) of the cylinder under study, a vibration pulse from the impact of the piston on an elastic tip placed in the combustion chamber is taken. This technique makes it possible to exclude the external influences and inaccuracies associated with a change in the geometry ICE elements.","PeriodicalId":12218,"journal":{"name":"FME Transactions","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90277685","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}
J. Dinis-Carvalho, Mónica F. J. R. Monteiro, Helena Macedo
Continuous Improvement (CI) is a principle being adopted in many organizations around the world. It is present in relevant excellence models such as the Toyota Way, Shingo Model, and Lean Thinking. CI was implemented some years ago in a Public Company (Lipor) based in Porto, dedicated to municipal waste treatment, but the Covid-19 pandemic created some important challenges. The forced adoption of new technologies associated with I4.0 required important changes in the existing CI routines. This paper aims to assess the influence of gender, education, age group, and time in the company on adopting new technologies used in their IC routines. This study, based on employees' perceptions through questionnaires, shows that the CI system had, in general, a positive impact on their work and overall performance. Regarding the effect of forced teleworking caused by COVID-19 on office workers, this study shows that age, gender, education, and years in the company have an impact on the effective adoption of new technologies associated with digital transformation and Industry 4.0. The study also shows that those technologies effectively allow routines and culture of CI to be maintained when workers are forced to work remotely.
{"title":"Influence of gender, education, age group and time in the company on the adoption of new technologies and their impact on continuous Improvement","authors":"J. Dinis-Carvalho, Mónica F. J. R. Monteiro, Helena Macedo","doi":"10.5937/fme2204635d","DOIUrl":"https://doi.org/10.5937/fme2204635d","url":null,"abstract":"Continuous Improvement (CI) is a principle being adopted in many organizations around the world. It is present in relevant excellence models such as the Toyota Way, Shingo Model, and Lean Thinking. CI was implemented some years ago in a Public Company (Lipor) based in Porto, dedicated to municipal waste treatment, but the Covid-19 pandemic created some important challenges. The forced adoption of new technologies associated with I4.0 required important changes in the existing CI routines. This paper aims to assess the influence of gender, education, age group, and time in the company on adopting new technologies used in their IC routines. This study, based on employees' perceptions through questionnaires, shows that the CI system had, in general, a positive impact on their work and overall performance. Regarding the effect of forced teleworking caused by COVID-19 on office workers, this study shows that age, gender, education, and years in the company have an impact on the effective adoption of new technologies associated with digital transformation and Industry 4.0. The study also shows that those technologies effectively allow routines and culture of CI to be maintained when workers are forced to work remotely.","PeriodicalId":12218,"journal":{"name":"FME Transactions","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83925163","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}
This paper proposes the PSO-FOPID controller, which is a Fractional Order Proportional-Integral-Derivative (FOPID) controller tuned using particle swarm optimization with spreading factor algorithm for height position control of a scissor mechanism platform. The tuning process of five control gains in the FOPID controller is technically challenging to achieve high position accuracy. In this study, this problem is addressed through the offline tuning method by using particle swarm optimization with the spreading factor algorithm to reduce the complexity in tuning the control gains. From the experimental study, it is found that the proposed controller can eliminate the steady-state error under the two input references with approximately 1.5% and 0.9% reductions of the overshoot and undershoot in the height position response as compared to its promising performances in simulations. It is envisaged that the PSOFOPID controller can be useful in designing effective height position control of a non-linear platform.
{"title":"Design, simulation and experiment of PSO-FOPID controller for height position control of a scissor mechanism platform","authors":"N. Norsahperi, S. Ahmad, S. Toha, M. Mutalib","doi":"10.5937/fme2201046n","DOIUrl":"https://doi.org/10.5937/fme2201046n","url":null,"abstract":"This paper proposes the PSO-FOPID controller, which is a Fractional Order Proportional-Integral-Derivative (FOPID) controller tuned using particle swarm optimization with spreading factor algorithm for height position control of a scissor mechanism platform. The tuning process of five control gains in the FOPID controller is technically challenging to achieve high position accuracy. In this study, this problem is addressed through the offline tuning method by using particle swarm optimization with the spreading factor algorithm to reduce the complexity in tuning the control gains. From the experimental study, it is found that the proposed controller can eliminate the steady-state error under the two input references with approximately 1.5% and 0.9% reductions of the overshoot and undershoot in the height position response as compared to its promising performances in simulations. It is envisaged that the PSOFOPID controller can be useful in designing effective height position control of a non-linear platform.","PeriodicalId":12218,"journal":{"name":"FME Transactions","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88941045","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}
Nikola Slavković, S. Zivanovic, Nikola Vorkapić, Z. Dimić
This paper presents an approach for developing the programming and offline simulation systems for low-cost industrial robots in the MatLab/Simulink environment. The approach is presented in the example of a virtual model of a 4-axis robot with hybrid kinematics intended for manipulation tasks. The industrial robot with hybrid kinematics consists of the well-known 5R planar parallel mechanism to which two serial axes have been added. The programming system developed in a MatLab environment involves generating G-code programs based on given pick and place points. The virtual model included in the simulation system is configured in the Simulink environment based on the CAD model of the robot and its kinematic structure. The kinematic model and the inverse kinematic problem have to be included in the virtual model to realize the motion of the virtual robot. The system of programming and simulation has been verified through several examples that include object manipulation to perform various tasks.
{"title":"Development of the programming and simulation system of 4-axis robot with hybrid kinematic","authors":"Nikola Slavković, S. Zivanovic, Nikola Vorkapić, Z. Dimić","doi":"10.5937/fme2203403s","DOIUrl":"https://doi.org/10.5937/fme2203403s","url":null,"abstract":"This paper presents an approach for developing the programming and offline simulation systems for low-cost industrial robots in the MatLab/Simulink environment. The approach is presented in the example of a virtual model of a 4-axis robot with hybrid kinematics intended for manipulation tasks. The industrial robot with hybrid kinematics consists of the well-known 5R planar parallel mechanism to which two serial axes have been added. The programming system developed in a MatLab environment involves generating G-code programs based on given pick and place points. The virtual model included in the simulation system is configured in the Simulink environment based on the CAD model of the robot and its kinematic structure. The kinematic model and the inverse kinematic problem have to be included in the virtual model to realize the motion of the virtual robot. The system of programming and simulation has been verified through several examples that include object manipulation to perform various tasks.","PeriodicalId":12218,"journal":{"name":"FME Transactions","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74996498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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