Rapid Prototyping Journal最新文献

{"title":"Investigations on friction stir spot welding to overcome bed size limits of material extrusion (MEX) 3D printers","authors":"Vivek Kumar Tiwary, Arunkumar Padmakumar, Vinayak R. Malik","doi":"10.1108/rpj-01-2023-0030","DOIUrl":"https://doi.org/10.1108/rpj-01-2023-0030","url":null,"abstract":"Purpose Material extrusion (MEX) 3D printers suffer from an intrinsic limitation of small size of the prints due to its restricted bed dimension. On the other hand, friction stir spot welding (FSSW) is gaining wide interest from automobile, airplane, off-road equipment manufacturers and even consumer electronics. This paper aims to explore the possibility of FSSW on Acrylonitrile Butadiene Styrene/Polylactic acid 3D-printed components to overcome the bed size limitation of MEX 3D printers. Design/methodology/approach Four different tool geometries (tapered cylindrical pin with/without concavity, pinless with/without concavity) were used to produce the joints. Three critical process parameters related to FSSW (tool rotational speed, plunge depth and dwell time) and two related to 3D printing (material combination and infill percentages) were investigated and optimized using the Taguchi L27 design of experiments. The influence of each welding parameter on the shear strength was evaluated by analysis of variance. Findings Results revealed that the infill percentage, a 3D printing parameter, had the maximum effect on the joint strength. The joints displayed pull nugget, cross nugget and substrate failure morphologies. The outcome resulted in the joint efficiency reaching up to 100.3%, better than that obtained by other competitive processes for 3D-printed thermoplastics. The results, when applied to weld a UAV wing, showed good strength and integrity. Further, grafting the joints with nylon micro-particles was also investigated, resulting in a detrimental effect on the strength. Originality/value To the best of the authors’ knowledge, this is the first study to demonstrate that the welding of dissimilar 3D-printed thermoplastics with/without microparticles is possible by FSSW, whilst the process parameters have a considerable consequence on the bond strength.","PeriodicalId":20981,"journal":{"name":"Rapid Prototyping Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135476949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Non-destructive evaluation of melt-extruded part quality using <i>in situ</i> data","authors":"Veera Harsha Vardhan Jilludimudi, Daniel Zhou, Eric Rubstov, Alexander Gonzalez, Will Daknis, Erin Gunn, David Prawel","doi":"10.1108/rpj-04-2023-0122","DOIUrl":"https://doi.org/10.1108/rpj-04-2023-0122","url":null,"abstract":"Purpose This study aims to collect real-time, in situ data from polymer melt extrusion (ME) 3D printing and use only the collected data to non-destructively identify printed parts that contain defects. Design/methodology/approach A set of sensors was created to collect real-time, in situ data from polymer ME 3D printing. A variance analysis was completed to identify an “acceptable” range for filament diameter on a popular desktop 3D printer. These data were used as the basis of a quality evaluation process to non-destructively identify spatial regions of printed parts in multi-part builds that contain defects. Findings Anomalous parts were correctly identified non-destructively using only in situ collected data. Research limitations/implications This methodology was developed by varying the filament diameter, one of the most common reasons for print failure in ME. Numerous other printing parameters are known to create faults in melt extruded parts, and this methodology can be extended to analyze other parameters. Originality/value To the best of the authors’ knowledge, this is the first report of a non-destructive evaluation of 3D-printed part quality using only in situ data in ME. The value is in improving part quality and reliability in ME, thereby reducing 3D printing part errors, plastic waste and the associated cost of time and material.","PeriodicalId":20981,"journal":{"name":"Rapid Prototyping Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135476831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Static load-carrying behavior and material properties of additively manufactured gears (PBF-LB/M, 16MnCr5)","authors":"Markus Brummer, Karl Jakob Raddatz, Matthias Moritz Schmitt, Georg Schlick, Thomas Tobie, Rüdiger Daub, Karsten Stahl","doi":"10.1108/rpj-02-2023-0035","DOIUrl":"https://doi.org/10.1108/rpj-02-2023-0035","url":null,"abstract":"Purpose Numerous metals can be processed using the additive manufacturing process laser-based powder bed fusion of metals (PBF-LB/M, ISO/ASTM 52900). The main advantages of additive manufacturing technologies are the high degree of design freedom and the cost-effective implementation of lightweight structures. This could be profitable for gears with increased power density, combining reduced mass with considerable material strength. Current research on additively manufactured gears is focused on developing lightweight structures but is seldom accompanied by simulations and even less by mechanical testing. There has been very little research into the mechanical and material properties of additively manufactured gears. The purpose of this study is to investigate the behavior of lightweight structures in additively manufactured gears under static loads. Design/methodology/approach This research identifies the static load-carrying capacity of helical gears with different lightweight structures produced by PBF-LB/M with the case hardening steel 16MnCr5. A static gear loading test rig with a maximum torque at the pinion of T 1 = 1200 Nm is used. Further focus is set on analyzing material properties such as the relative density, microstructure, hardness depth profile and chemical composition. Findings All additively manufactured gear variants show no failure or plastic deformation at the maximum test load. The shaft hub connection, the lightweight hub designs and the gearing itself are stable and intact regarding their form and function. The identified material characteristics are comparable to conventionally manufactured gears (wrought and machined), but also some particularities were observed. Originality/value This research demonstrates the mechanical strength of lightweight structures in gears. Future research needs to consider the dynamic load-carrying capacity of additively manufactured gears.","PeriodicalId":20981,"journal":{"name":"Rapid Prototyping Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135587270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of additively manufactured flexible wing model","authors":"Rossana Fernandes, Benyang Hu, Zhichao Wang, Zheng Zhang, Ali Y. Tamijani","doi":"10.1108/rpj-03-2023-0112","DOIUrl":"https://doi.org/10.1108/rpj-03-2023-0112","url":null,"abstract":"Purpose This paper aims to assess the feasibility of additively manufactured wind tunnel models. The additively manufactured model was used to validate a computational framework allowing the evaluation of the performance of five wing models. Design/methodology/approach An optimized fighter wing was additively manufactured and tested in a low-speed wind tunnel to obtain the aerodynamic coefficients and deflections at different speeds and angles of attack. The flexible wing model with optimized curvilinear spars and ribs was used to validate a finite element framework that was used to study the aeroelastic performance of five wing models. As a computationally efficient optimization method, homogenization-based topology optimization was used to generate four different lattice internal structures for the wing in this study. The efficiency of the spline-based optimization used for the spar-rib model and the lattice-based optimization used for the other four wings were compared. Findings The aerodynamic loads and displacements obtained experimentally and computationally were in good agreement, proving that additive manufacture can be used to create complex accurate models. The study also shows the efficiency of the homogenization-based topology optimization framework in generating designs with superior stiffness. Originality/value To the best of the authors’ knowledge, this is the first time a wing model with curvilinear spars and ribs was additively manufactured as a single piece and tested in a wind tunnel. This research also demonstrates the efficiency of homogenization-based topology optimization in generating enhanced models of different complexity.","PeriodicalId":20981,"journal":{"name":"Rapid Prototyping Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134884037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Additively manufactured medical bone screws: an initial study to investigate the impact of lattice-based Voronoi structure on implant primary stability","authors":"Chiara Bregoli, Jacopo Fiocchi, Carlo Alberto Biffi, Ausonio Tuissi","doi":"10.1108/rpj-10-2022-0363","DOIUrl":"https://doi.org/10.1108/rpj-10-2022-0363","url":null,"abstract":"Purpose The present study investigates the mechanical properties of three types of Ti6Al4V ELI bone screws realized using the laser powder bed fusion (LPBF) process: a fully threaded screw and two groups containing differently arranged sectors made of lattice-based Voronoi (LBV) structure in a longitudinal and transversal position, respectively. This study aims to explore the potentialities related to the introduction of LBV structure and assess its impact on the implant’s primary stability and mechanical performance. Design/methodology/approach The optimized bone screw designs were realized using the LPBF process. The quality and integrity of the specimens were assessed by scanning electron microscopy and micro-computed tomography. Primary stability was experimentally verified by the insertion and removal of the screws in standard polyurethane foam blocks. Finally, torsional tests were carried out to compare and assess the mechanical strength of the different designs. Findings The introduction of the LBV structure decreases the elastic modulus of the implant. Longitudinal LBV type screws demonstrated the lowest insertion torque (associated with lower bone damage) while still displaying promising torsional strength and removal force compared with full-thread screws. The use of LBV structure can promote improved functional performances with respect to the reference thread, enabling the use of lattice structures in the biomedical sector. Originality/value The paper fulfils an identified interest in designing customized implants with improved primary stability and promising features for secondary stability.","PeriodicalId":20981,"journal":{"name":"Rapid Prototyping Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134903909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Explainable deep neural network for in-plain defect detection during additive manufacturing","authors":"Deepak Kumar, Yongxin Liu, Houbing Song, Sirish Namilae","doi":"10.1108/rpj-05-2023-0157","DOIUrl":"https://doi.org/10.1108/rpj-05-2023-0157","url":null,"abstract":"Purpose The purpose of this study is to develop a deep learning framework for additive manufacturing (AM), that can detect different defect types without being trained on specific defect data sets and can be applied for real-time process control. Design/methodology/approach This study develops an explainable artificial intelligence (AI) framework, a zero-bias deep neural network (DNN) model for real-time defect detection during the AM process. In this method, the last dense layer of the DNN is replaced by two consecutive parts, a regular dense layer denoted (L1) for dimensional reduction, and a similarity matching layer (L2) for equal weight and non-biased cosine similarity matching. Grayscale images of 3D printed samples acquired during printing were used as the input to the zero-bias DNN. Findings This study demonstrates that the approach is capable of successfully detecting multiple types of defects such as cracks, stringing and warping with high accuracy without any prior training on defective data sets, with an accuracy of 99.5%. Practical implications Once the model is set up, the computational time for anomaly detection is lower than the speed of image acquisition indicating the potential for real-time process control. It can also be used to minimize manual processing in AI-enabled AM. Originality/value To the best of the authors’ knowledge, this is the first study to use zero-bias DNN, an explainable AI approach for defect detection in AM.","PeriodicalId":20981,"journal":{"name":"Rapid Prototyping Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134884036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid prototyping of 3d printed micropillars using fused filament fabrication technique for biomedical applications","authors":"Shamima Khatoon, Gufran Ahmad","doi":"10.1108/rpj-03-2023-0096","DOIUrl":"https://doi.org/10.1108/rpj-03-2023-0096","url":null,"abstract":"Purpose The hygroscopic properties of 3D-printed filaments and moisture absorption itself during the process result in dimensional inaccuracy, particularly for nozzle movement along the x-axis and for micro-scale features. In view of that, this study aims to analyze in depth the dimensional errors and deviations of the fused filament fabrication (FFF)/fused deposition modeling (FDM) 3D-printed micropillars (MPs) from the reference values. A detailed analysis into the variability in printed dimensions below 1 mm in width without any deformations in the printed shape of the designed features, for challenging filaments like polymethyl methacrylate (PMMA) has been done. The study also explores whether the printed shape retains the designed structure. Design/methodology/approach A reference model for MPs of width 800 µm and height 2,000 µm is selected to generate a g-code model after pre-processing of slicing and meshing parameters for 3D printing of micro-scale structure with defined boundaries. Three SETs, SET-A, SET-B and SET-C, for nozzle diameter of 0.2 mm, 0.25 mm and 0.3 mm, respectively, have been prepared. The SETs containing the MPs were fabricated with the spacing (S) of 2,000 µm, 3,200 µm and 4,000 µm along the print head x-axis. The MPs were measured by taking three consecutive measurements (top, bottom and middle) for the width and one for the height. Findings The prominent highlight of this study is the successful FFF/FDM 3D printing of thin features (<1mm) without any deformation. The mathematical analysis of the variance of the optical microscopy measurements concluded that printed dimensions for micropillar widths did not vary significantly, retaining more than 65% of the recording within the first standard deviation (SD) (±1 s). The minimum value of SD is obtained from the samples of SET-B, that is, 31.96 µm and 35.865 µm, for height and width, respectively. The %RE for SET-B samples is 5.09% for S = 2,000µm, 3.86% for S = 3,200µm and 1.09% for S = 4,000µm. The error percentage is so small that it could be easily compensated by redesigning. Research limitations/implications The study does not cover other 3D printing techniques of additive manufacturing like stereolithography, digital light processing and material jetting. Practical implications The presented study can be potentially implemented for the rapid prototyping of microfluidics mixer, bioseparator and lab-on-chip devices, both for membrane-free bioseparation based on microfiltration, plasma extraction from whole blood, size-selection trapping of unwanted blood cells, and also for membrane-based plasma extraction that requires supporting microstructures. Our developed process may prove to be far more economical than the other existing techniques for such applications. Originality/value For the first time, this work presents a comprehensive analysis of the fabrication of micropillars using FDM/FFF 3D printing and PMMA in filament form. The primary focus of the study is to min","PeriodicalId":20981,"journal":{"name":"Rapid Prototyping Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136263385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and characterization of composite materials with multi-walled carbon nanotubes and graphene nanoplatelets for powder bed fusion","authors":"Ana C. Lopes, Álvaro M. Sampaio, António J. Pontes","doi":"10.1108/rpj-04-2023-0142","DOIUrl":"https://doi.org/10.1108/rpj-04-2023-0142","url":null,"abstract":"Purpose With the technological progress, high-performance materials are emerging in the market of additive manufacturing to comply with the advanced requirements demanded for technical applications. In selective laser sintering (SLS), innovative powder materials integrating conductive reinforcements are attracting much interest within academic and industrial communities as promising alternatives to common engineering thermoplastics. However, the practical implementation of functional materials is limited by the extensive list of conditions required for a successful laser-sintering process, related to the morphology, powder size and shape, heat resistance, melt viscosity and others. The purpose of this study is to explore composite materials of polyamide 12 (PA12) incorporating multi-walled carbon nanotubes (MWCNT) and graphene nanoplatelets (GNP), aiming to understand their suitability for advanced SLS applications. Design/methodology/approach PA12-MWCNT and PA12-GNP materials were blended through a pre-optimized process of mechanical mixing with various percentages of reinforcement between 0.50 wt.% and 3.00 wt.% and processed by SLS with appropriate volume energy density. Several test specimens were produced and characterized with regard to processability, thermal, mechanical, electrical and morphological properties. Finally, a comparative analysis of the performance of both carbon-based materials was performed. Findings The results of this research demonstrated easier processability and higher tensile strength and impact resistance for composites incorporating MWCNT but higher tensile elastic modulus, compressive strength and microstructural homogeneity for GNP-based materials. Despite the decrease in mechanical properties, valuable results of electrical conductivity were obtained with both carbon solutions until 10 –6 S/cm. Originality/value The carbon-based composites developed in this research allow for the expansion of the applicability of laser-sintered parts to advanced fields, including electronics-related industries that require functional materials capable of protecting sensitive devices against electrostatic discharge.","PeriodicalId":20981,"journal":{"name":"Rapid Prototyping Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135109545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of copper interlayer on the interface characteristics of stainless steel–aluminium transitional structure in wire arc directed energy deposition","authors":"Amrit Raj Paul, Manidipto Mukherjee, Mohit Kumar Sahu","doi":"10.1108/rpj-03-2023-0089","DOIUrl":"https://doi.org/10.1108/rpj-03-2023-0089","url":null,"abstract":"Purpose The purpose of this study is to investigate the deposition of SS–Al transitional wall using the wire arc directed energy deposition (WA-DED) process with a Cu interlayer. This study also aims to analyse the metallographic properties of the SS–Cu and Al–Cu interfaces and their mechanical properties. Design/methodology/approach The study used transitional deposition of SS–Al material over each other by incorporating Cu as interlayer between the two. The scanning electron microscope analysis, energy dispersive X-ray analysis, X-ray diffractometer analysis, tensile testing and micro-hardness measurement were performed to investigate the interface characteristics and mechanical properties of the SS–Al transitional wall. Findings The study discovered that the WA-DED process with a Cu interlayer worked well for the deposition of SS–Al transitional walls. The formation of solid solutions of Fe–Cu and Fe–Si was observed at the SS–Cu interface rather than intermetallic compounds (IMCs), according to the metallographic analysis. On the other hand, three different IMCs were formed at the Al–Cu interface, namely, Al–Cu, Al 2 Cu and Al 4 Cu 9 . The study also observed the formation of a lamellar structure of Al and Al 2 Cu at the hypereutectic phase. The mechanical testing revealed that the Al–Cu interface failed without significant deformation, i.e. < 4.73%, indicating the brittleness of the interface. Originality/value The study identified the formation of HCP–Fe at the SS–Cu interface, which has not been previously reported in additive manufacturing literature. Furthermore, the study observed the formation of a lamellar structure of Al and Al2Cu phase at the hypereutectic phase, which has not been previously reported in SS–Al transitional wall deposition.","PeriodicalId":20981,"journal":{"name":"Rapid Prototyping Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135824549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring innovation system dynamics: event history analysis of the evolution of the South African additive manufacturing industry","authors":"Michelle McClelland, Sara Grobbelaar, N. Sacks","doi":"10.1108/rpj-04-2023-0143","DOIUrl":"https://doi.org/10.1108/rpj-04-2023-0143","url":null,"abstract":"\u0000Purpose\u0000This paper aims to explore the growth of the South African additive manufacturing (AM) industry over the past 31 years through the lens of the innovation system (IS) perspective, examining the actor dynamics and mechanisms that facilitated or hindered the industry’s development.\u0000\u0000\u0000Design/methodology/approach\u0000The study used a case study research approach, analysing semi-structured interviews with eight South African AM experts and documentary evidence. The IS framework and the realist evaluation perspective were used, using a context-intervention-mechanism-outcome (CIMO)-based event history analysis (EHA) framework to explore the actor dynamics and mechanisms of the case study.\u0000\u0000\u0000Findings\u0000The study used a case study research approach, analysing semi-structured interviews with eight South African AM experts and documentary evidence. The IS framework and the realist evaluation perspective were used, using a CIMO-based EHA framework to explore the actor dynamics and mechanisms of the case study.\u0000\u0000\u0000Originality/value\u0000This paper contributes to the South African AM industry literature by providing an overview of the industry events over the past three decades and analysing the industry through the IS framework. The study is among the first to analyse the development of the South African AM industry, presenting innovation scholars and managers with valuable decision-making support by providing insights into the innovation activities performed during each stage of the industry’s development, who performed them, the sequence in which they were performed and the outcomes they delivered.\u0000","PeriodicalId":20981,"journal":{"name":"Rapid Prototyping Journal","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2023-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44537190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}