Journal of Advanced Joining Processes最新文献

{"title":"Effects of laminate stacking sequence on the strength properties of aluminum alloy–carbon fiber-reinforced plastic dissimilar single-lap adhesive joints","authors":"Kazuhiro kusukawa","doi":"10.1016/j.jajp.2024.100239","DOIUrl":"10.1016/j.jajp.2024.100239","url":null,"abstract":"<div><p>Here, two single-lap adhesive joints (SLJs) of dissimilar materials were subjected to static and cyclic loading tests. A2017 aluminum alloy was used as an adherend for one, and carbon fiber reinforced plastic (CFRP) was used as the adherend for the other. Four types of orthogonal laminated CFRPs with different laminate stacking sequences were used as adherends to investigate the effect of adherend stiffness on the strength properties of the joints. Furthermore, the results of the finite element analysis of the dissimilar SLJs revealed that when the tensile load was applied to them, the out-of-plane deformation asymmetry increased with increasing difference in stiffness between both adherends. This asymmetry affected the peel and shear stress distributions. Furthermore, the experiments revealed that the static tensile strength of the SLJs increased with increasing stiffness of the CFRP adherend. Additionally, fracture simulation using cohesive-zone modeling (CZM) revealed that the SLJs with higher CFRP stiffness exhibited higher strength, qualitatively agreeing with the experimental results. CZM analysis and adhesion strain measurements during the tests indicated that failure occurred at the A2017 adherend–adhesive interface. In contrast, no differences were observed between the fatigue strengths of the different types of adherends in the short-life region, with a number of cycles to failure (N_f) being ≤ 2 × 10⁵. However, in the long-life region, beyond N_f = 2 × 10⁵, the SLJ bearing the unidirectional CFRP adherend exhibited lower fatigue strength than the others. The anodizing process on A2017 was found to improve fatigue strength by a factor of two or more.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"10 ","pages":"Article 100239"},"PeriodicalIF":3.8,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666330924000554/pdfft?md5=fc35686a8b4ac80f50530c5b1ef9a771&pid=1-s2.0-S2666330924000554-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141842298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Disclosing connection links between microstructure and mechanical performance in pulsating current gas tungsten arc welding of Hastelloy B-2 superalloy","authors":"Mehdi Khalasi Dezfuli ,&nbsp;Ali Heidary Moghadam ,&nbsp;Mehdi Ghobeiti Hasab ,&nbsp;Rouholah Ashiri","doi":"10.1016/j.jajp.2024.100237","DOIUrl":"https://doi.org/10.1016/j.jajp.2024.100237","url":null,"abstract":"<div><p>In this study, welding a Ni-Mo-based superalloy (Hastelloy B-2) was examined in order to characterize the microstructure and mechanical performance of joints along with assessing the effects of current intensity on the microstructure and mechanical responses of different weld zones. The gas tungsten arc welding (GTAW) process was used to weld the samples using ERNiCrMo-2 filler metal. The pulsed current GTAW process was used to weld the superalloy sheets of thickness of 1 mm with background current (I_b) of 20 A and 40 A and peak current (I_p) of 80 A and 60 A. Tensile and Vickers microhardness tests were conducted to evaluate the effect of pulsed current on mechanical properties of the welds along with chemistry and microstructure characterizations. Finally, the fracture surfaces after the tensile test were studied using SEM fractography analysis. The results indicated that increasing I_b and decreasing I_p led to low heat input and high cooling rate resulting in a high thermal gradient. This caused microstructure transition from the columnar dendrites to the coaxial ones in the weld zone; molten metal convection in the fusion zone led to fine grains in the weld zone during welding time. Moreover, a significant decrease in the amount of molybdenum carbides at the interdendritic regions of the weld metal was observed under these conditions. The tensile strength of the weld metal was higher than that of the base metal resulting in the fracture of all welds from the base metal. Additionally, the microhardness results indicated a significant increase for the weld metal compared to both heat-affected zone (HAZ) and base metal. The higher mechanical properties of the weld metal is attributed to the increase in background current and decrease in peak current leading to a fine grain microstructure. Fractography following the tensile test showed a completely ductile fracture.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"10 ","pages":"Article 100237"},"PeriodicalIF":3.8,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666330924000530/pdfft?md5=b8f5e1a7f4a5a0f82392aba7f95844d3&pid=1-s2.0-S2666330924000530-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141480959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of stacking-fault energy on dynamic recrystallization, textural evolution, and strengthening mechanism of Fe−Mn based twinning-induced plasticity (TWIP) steels during friction-stir welding","authors":"Hyo-Nam Choi ,&nbsp;Jeong-Won Choi ,&nbsp;Heon Kang ,&nbsp;Hidetoshi Fujii ,&nbsp;Seung-Joon Lee","doi":"10.1016/j.jajp.2024.100236","DOIUrl":"https://doi.org/10.1016/j.jajp.2024.100236","url":null,"abstract":"<div><p>This study aims to elucidate the effect of stacking fault energy (SFE) on the microstructural evolution and related hardening mechanisms of Fe−18Mn−0.6C−(0 and 1.5)Al and Fe−30Mn−3Al−3Si (wt.%) twinning−induced plasticity (TWIP) steels during friction stir welding (FSW) using a high−resolution electron backscattered diffractometer. With increasing SFE, the intensities of the Goss, CuT, and Brass components increased via active dynamic recrystallization (DRX) accompanied by twinning. The 30Mn weld, which had the highest SFE, exhibited the highest recrystallization fraction (94.8 %) and an increasing rate of hardness (40.9 %). This is because a higher SFE can enhance dislocation mobility, leading to an active rate of continuous DRX as well as discontinuous DRX. Consequently, the refinement of the recrystallized grains effectively assisted the hardening of the 30Mn weld after FSW. Hence, we concluded that SFE should be considered to improve the properties of TWIP steels after FSW.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"10 ","pages":"Article 100236"},"PeriodicalIF":3.8,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666330924000529/pdfft?md5=e6671d015e66fa13f220e57320998bdb&pid=1-s2.0-S2666330924000529-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141543691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Replacing non-renewable lubricants with vegetables oils in threaded joints","authors":"Dario Croccolo ,&nbsp;Massimiliano De Agostinis ,&nbsp;Stefano Fini ,&nbsp;Mattia Mele ,&nbsp;Sayed Nassar ,&nbsp;Giorgio Olmi ,&nbsp;Chiara Scapecchi ,&nbsp;Muhammad Yasir Khan ,&nbsp;Muhammad Hassaan Bin Tariq","doi":"10.1016/j.jajp.2024.100234","DOIUrl":"https://doi.org/10.1016/j.jajp.2024.100234","url":null,"abstract":"<div><p>Lubrication is essential to ensure the proper performance of threaded joints subjected to multiple tightenings. Previous research has investigated the effectiveness of various mineral and synthetic lubricants, but no studies have been conducted on those derived from renewable sources. In this study, the performances of sesame, sunflower, coconut, and castor oil are compared to traditional VG46 oil and MoS<span><math><msub><mrow></mrow><mn>2</mn></msub></math></span> grease. First, the rheological properties of the oils have been characterized. Then, tightening tests have been carried out to measure the coefficients of friction at the underhead and thread. The results demonstrate that vegetable oils outperform mineral VG46, especially in terms of repeatability. In particular, fractionated coconut oil exhibits exceptionally low coefficients of friction, which are not influenced by the tightening speed, unlike all other tested lubricants.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"10 ","pages":"Article 100234"},"PeriodicalIF":3.8,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666330924000505/pdfft?md5=0fe4881aa94d22efd195a455d7a99e71&pid=1-s2.0-S2666330924000505-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141479437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal and spatial determination of solidification rate during pulsed laser beam welding of hot-crack susceptible aluminum alloys by means of high-speed synchrotron X-ray imaging","authors":"M. Seibold ,&nbsp;K. Schricker ,&nbsp;L. Schmidt ,&nbsp;D. Diegel ,&nbsp;H. Friedmann ,&nbsp;P. Hellwig ,&nbsp;F. Fröhlich ,&nbsp;F. Nagel ,&nbsp;P. Kallage ,&nbsp;A. Rack ,&nbsp;H. Requardt ,&nbsp;Y. Chen ,&nbsp;J.P. Bergmann","doi":"10.1016/j.jajp.2024.100235","DOIUrl":"10.1016/j.jajp.2024.100235","url":null,"abstract":"<div><p>Pulsed laser beam welding is primarily used to join thin-walled components. The use of 6xxx group aluminum alloys is characterized by good mechanical properties but these alloys are prone to hot cracking during solidification, i.e., requirements regarding strength and tightness, as increasingly important for electromobility related applications, cannot be fulfilled. The solidification rate has been identified as dominant factor in pulsed conduction welding which can be adjusted by the pulse shape, i.e., by varying the beam power over time for a single pulse.</p><p>Pulse shapes with different, linear ramp-down slopes were studied to describe the interaction between beam power and resulting solidification rate for spot welds. Based on rotationally symmetric conditions of the spot welds, the solidification rate can be measured in radial and vertical directions. The welding process of EN AW 6082 alloy was examined by in situ high-speed synchrotron X-ray imaging at the European Synchrotron Radiation Facility (ESRF) for this reason. Frame rates up to 120,000 Hz and subsequent image analysis allowed in-depth analysis of the solidification processes, their dependence on different spatial directions, and the resulting effects on hot crack formation.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"10 ","pages":"Article 100235"},"PeriodicalIF":3.8,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666330924000517/pdfft?md5=671fe0d549916cdad86564cd55cbc805&pid=1-s2.0-S2666330924000517-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141401503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rotary friction welding applied to Cu11.8Al0.45Be shape memory alloy","authors":"A.A.de Albuquerque ,&nbsp;H. Louche ,&nbsp;D.F.de Oliveira ,&nbsp;I.C.A. Brito","doi":"10.1016/j.jajp.2024.100233","DOIUrl":"https://doi.org/10.1016/j.jajp.2024.100233","url":null,"abstract":"<div><p>The feasibility of welding a CuAlBe SMA by continuous drive friction welding was evaluated. The metallurgical state (annealed/quenched) before welding and frictional pressure (5 and 10 MPa) were varied and their effects on joint quality were analyzed. Static tensile tests, microhardness, thermal analysis by DSC, and optical microscopy were carried out to characterize the welded joint. The results indicated joints of excellent thermomechanical quality. The welding zones are well-defined, narrow, and have a very refined microstructure compared to the base metal. The phase transition temperatures along the welded assemblies were not changed when welding was performed on the quenched samples, except in the welding zone of the sample welded with 10 MPa. Maximum tensile strength was obtained by using maximum friction pressure during welding of the annealed alloy (quenching after welding). To fill the gap in bibliographical research in this field of study, this work innovatively presents the possibility of welding Cu-based SMAs by rotary friction, including the welding of quenched parts without the need for subsequent heat treatments and without compromising the shape memory effect.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"10 ","pages":"Article 100233"},"PeriodicalIF":4.1,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666330924000499/pdfft?md5=02c3b41a224ce56ef8cf188c0b1cc15d&pid=1-s2.0-S2666330924000499-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141333146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation on submerged friction stir welding of AZ31B magnesium alloy under the influence of rotation speed","authors":"Kishan Fuse ,&nbsp;Kiran Wakchaure ,&nbsp;Vishvesh Badheka ,&nbsp;Vivek Patel","doi":"10.1016/j.jajp.2024.100232","DOIUrl":"https://doi.org/10.1016/j.jajp.2024.100232","url":null,"abstract":"<div><p>In this study, submerged friction stir welding (SFSW) was performed to weld 6 mm thick AZ31B Mg alloy plates, aiming to explore the impact of rotation speed on microstructure and tensile behavior. The water medium was used to submerge the samples. The SFSW was conducted at three different speeds (815, 960, and 1200 rpm), to assess the impact of rotation speed on SFSWed joint performance. As the rotation speed increased from 815 to 960 rpm, tensile strength increased plateauing over a range of the rotation speed. However, a significant drop in tensile strength occurred at 1200 rpm due to the formation of void defects. The SZ exhibits a size and width increment in the lower part with increasing rotation speed. The hardness of the stir zone (SZ) gradually rose with increasing rotation speed from 815 to 960 rpm. Fracture locations were observed in the thermal-mechanically affected zone (TMAZ) adjacent to the SZ at a rotation speed of 815 rpm, and in the heat-affected zone (HAZ) adjacent to the TMAZ at a rotation speed of 960 rpm. The joint welded at 1200 rpm fractured within the SZ. This study offers valuable insights into the welding and joining field, particularly regarding their mechanical characteristics.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"10 ","pages":"Article 100232"},"PeriodicalIF":4.1,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666330924000487/pdfft?md5=727bc0e32442b8924646b246cfe9ce1a&pid=1-s2.0-S2666330924000487-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141326224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Machine learning-based weld porosity detection using frequency analysis of arc sound in the pulsed gas tungsten arc welding process","authors":"Seungbeom Jang ,&nbsp;Wonjoo Lee ,&nbsp;Yuhyeong Jeong ,&nbsp;Yunfeng Wang ,&nbsp;Chanhee Won ,&nbsp;Jangwook Lee ,&nbsp;Jonghun Yoon","doi":"10.1016/j.jajp.2024.100231","DOIUrl":"https://doi.org/10.1016/j.jajp.2024.100231","url":null,"abstract":"<div><p>Automatic welding equipment has replaced human welders in the nuclear industry for safety issues and uniform and high welding quality. However, automatic welding equipment cannot predict porosity defects. So, the weldment must be inspected by non-destructive testing. This inspection was a costly and time-consuming process, and it applies to each weldment even if it welded same material. To improve the welding efficiency, a weld porosity detection system of the same weld material with different material thicknesses was needed. This paper proposed a machine-learned porosity detection system for 3.0 mm plates with welding arc sound data from the pulsed gas tungsten arc welding (P-GTAW) process of 1.6 mm plates. Ensemble-Empirical Mode Decomposition (EEMD) was used to divide the arc sound signal according to the pulse period of P-GTAW. Fast Fourier transform (FFT) was used to convert the arc sound into frequencies for features extraction according to porosity. The validity of these weld frequency features was confirmed through k-fold cross-validation across various machine learning techniques, with evaluation of F-1 scores against experimental weld sounds.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"10 ","pages":"Article 100231"},"PeriodicalIF":4.1,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666330924000475/pdfft?md5=aa20a67e4b54d518290f96b1d5b30986&pid=1-s2.0-S2666330924000475-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141326223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An experimental study on the quality of hardfacing layer through resistance seam welding","authors":"Minh-Tan Nguyen,&nbsp;Van-Nhat Nguyen,&nbsp;Van-The Than,&nbsp;Thi-Thao Ngo","doi":"10.1016/j.jajp.2024.100230","DOIUrl":"https://doi.org/10.1016/j.jajp.2024.100230","url":null,"abstract":"<div><p>Shaft-shaped parts work normally in wear-resistant conditions. Over time, the shaft might experience wear and fail to maintain the required size, affecting its workability and efficacy. This study examines the hardfacing layer quality of a restored steel shaft obtained through resistance welding. The researchers of this study designed nine welding conditions according to Taguchi's experimental matrix and applied each to experimentally weld steel shaft samples. A recovery welding machine system, which includes a resistance seam welding machine combined with a designed fixture, was used to weld the samples. The experimental results revealed that the welding layers’ surface is flat and has no surface defects. Meanwhile, the hardfacing layer and the retorted shaft surface have good cohesion, as observed through macrostructure photography. The hardness and wear resistance of the hardfacing layer were relatively high and closely resembled those of a new high-frequency quenched steel shaft. The influence level and the relationship of the welding parameters on hardness and wear resistance were also considered in this study. In addition, this study proposes the appropriate welding conditions for obtaining the highest hardness and the smallest worn metal weight. The findings presented in this study offer valuable insights for mechanical manufacturers engaged in the reconditioning process of shafts, aiding in time and cost savings.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"9 ","pages":"Article 100230"},"PeriodicalIF":4.1,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666330924000463/pdfft?md5=b318b4667c92487b229bacdfee58f024&pid=1-s2.0-S2666330924000463-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141243931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimentally-guided finite element modeling on global tensile responses of AA6061-T6 aluminum alloy joints by laser welding","authors":"Jie Sheng ,&nbsp;Fanrong Kong ,&nbsp;Wei Tong","doi":"10.1016/j.jajp.2024.100229","DOIUrl":"https://doi.org/10.1016/j.jajp.2024.100229","url":null,"abstract":"<div><p>There are still some technical issues involved in laser welding of aluminum alloys, such as porosity, cracking, deformation, and so forth. In this study, AA6061-T6 sheets of 2.54 mm in thickness were welded by a disk laser in the bead-on-plate with two different welding parameter sets. Full penetration depths were achieved with decent surface appearances for both cases. The digital image correlation method was successfully applied in experiments to identify material model parameters of tensile welded specimens from various weldment regions. The identified parameters were utilized to numerically simulate the uniaxial tensile tests of laser-welded specimens. The effect of welded joint geometry on global tensile responses was investigated in experimentally-guided finite element modeling. With the help of X-ray computed microtomography, internal defects of the welded bead were detected and used as an input variable in the simulations. Strain development was observed through experimental and numerical data. The results showed that axial deformation was initiated at the top surface of welded metals. The considerable axial deformation occurred at the bottom surface (weld root) of the welded joint just before failure. The numerical results indicated that the geometry of welded joints greatly affected tensile responses. The results also concluded that the diameter of a single void significantly influenced tensile responses compared to its distributed location and the total volume of multiple voids with smaller sizes. Compared between the two sets of welding parameter sets used in this study, the welded joints of this particular AA6061-T6 material with the first parameter set of 2.40 kW laser power and 1.27 m/min traveling speed employed could give better tensile properties and be verified by both experimental and numerical results.</p></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"9 ","pages":"Article 100229"},"PeriodicalIF":4.1,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666330924000451/pdfft?md5=1c789b10c1aa9caaa4e30af38506c673&pid=1-s2.0-S2666330924000451-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141095588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}