3D contact analysis of conjugate spur gears by a complete mating process

James Shih-Shyn Wu,Shu-Ling Xu,Yi-Tsung Lin,Wei-Hung Chen,Yuan-Lung Lai 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.12

Instead of applying fixed boundary conditions to constrain and simplify material behavior in 2D models, the point and line contact of tooth surfaces are substituted by a face-contact model of teeth in this study. The inaccurate prediction of load, deformation, and stress in 3D contacts are solved. Most research uses one pair to three pairs of meshing teeth to simulate the mating process. However, describing the entire process of three contact zones during each mating pair is insufficient. By implementing a combined 3D face contact and finite element method, the contact stress analyses between two spur gear teeth are conducted in 11 different contact positions during a full mating process. The proposed approach provides a complete and effective solution to the contact problem in a quasi-dynamic manner. This model not only determines the load-sharing prediction but also verifies the applied boundary conditions.

Simulation of an X-ray Fresnel Zone Plate with Nonideal Factors

Chen, Jie,Fan, Quanping,Wang, Junhua,Yuan, Dengpeng,Wei, Lai,Zhang, Qiangqiang,Liao, Junsheng,Xu, Min Optical Society of Korea 2020 Current Optics and Photonics Vol.4 No.1

Fresnel zone plates have been widely used in many applications, such as x-ray telescopes, microfluorescence, and microimaging. To obtain an x-ray Fresnel zone plate, many fabrication methods, such as electron-beam etching, ion-beam etching and chemical etching, have been developed. Fresnel zone plates fabricated by these methods will inevitably lead to some nonideal factors, which have an impact on the focusing characteristics of the zone plate. In this paper, the influences of these nonideal factors on the focusing characteristics of the zone plate are studied systematically, by numerical simulations based on scalar diffraction theory. The influence of the thickness of a Fresnel zone plate on the absolute focusing efficiency is calculated for a given incident x-ray's wavelength. The diffraction efficiency and size of the focal spot are calculated for different incline angles of the groove. The simulations of zone plates without struts, with regular struts, and with random struts are carried out, to study the effects of struts on the focusing characteristics of a zone plate. When a Fresnel zone plate is used to focus an ultrashort x-ray pulse, the effect of zone-plate structure on the final pulse duration is also discussed.

Simulation of an X-ray Fresnel Zone Plate with Nonideal Factors

Jie Chen,Quanping Fan,Junhua Wang,Dengpeng Yuan,Lai Wei,Qiangqiang Zhang,Junsheng Liao,Min Xu 한국광학회 2020 Current Optics and Photonics Vol.4 No.1

Fresnel zone plates have been widely used in many applications, such as x-ray telescopes, microfluorescence, and microimaging. To obtain an x-ray Fresnel zone plate, many fabrication methods, such as electron-beam etching, ion-beam etching and chemical etching, have been developed. Fresnel zone plates fabricated by these methods will inevitably lead to some nonideal factors, which have an impact on the focusing characteristics of the zone plate. In this paper, the influences of these nonideal factors on the focusing characteristics of the zone plate are studied systematically, by numerical simulations based on scalar diffraction theory. The influence of the thickness of a Fresnel zone plate on the absolute focusing efficiency is calculated for a given incident x-ray’s wavelength. The diffraction efficiency and size of the focal spot are calculated for different incline angles of the groove. The simulations of zone plates without struts, with regular struts, and with random struts are carried out, to study the effects of struts on the focusing characteristics of a zone plate. When a Fresnel zone plate is used to focus an ultrashort x-ray pulse, the effect of zone-plate structure on the final pulse duration is also discussed.

Stable Cu-Co/C carbon-based composites for efficiency catalytic degradation of Orange II by PMS: Effect factors, application potential analysis, and mechanism

Xiaodan Huang,Caihua Liu,Zhiyong Zhang,V. Vasanthakumar,Huiying Ai,Lei Xu,Ming-Lai Fu,Baoling Yuan 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.126 No.-

Carbon-based metallic catalysts (CMCs) have emerged as efficient materials for removing water contaminants,but preparing CMCs with high efficiency and stability remains a great challenge. In this study, weprepared a bimetallic composite of Cu-Co/C catalyst via a gelation and calcination method to degradeOrange II by activating peroxymonosulfate (PMS). The characterization results demonstrated that thespecific surface area and pore size of Cu-Co/C catalysts were 1.675 m2/g and 6.313 nm, respectively,which can provide larger catalytic active sites for boosting PMS activation. Moreover, the effects of differentfactors on Orange II degradation efficiency, cyclic experiments, and possible application in realwater bodies were investigated. The Cu-Co/C catalyst can effectively activate PMS, and 50 mg/L ofOrange II was almost completely removed within 15 min. Additionally, the Cu-Co/C catalyst exhibitedhigh degradation efficiency for other organic dye pollutants. The radical quenching experiments indicatedthat the main active species for Cu-Co/C catalyzed degradation of Orange II were SO4and singlet oxygen(1O2). The catalyst demonstrated good stability and performance in real water bodies. We believe thatthis study will promote the application of carbon-based bimetallic catalysts in the environmental remediationprocess that utilize SO4based advanced oxidation.

Effects of co-ion initial concentration ratio on removal of Pb2+ from aqueous solution by modified sugarcane bagasse

Jing Zhu,Jun-xia Yu,Jia-dong Chen,Jie-sen Zhang,Jia-qi Tang,Yuan-lai Xu,Yue-fei Zhang,Ru-an Chi 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.6

A modified sugarcane bagasse (SCB) fixed bed column was used to remove Pb2+ from aqueous solution. To determine the optimal condition for Pb2+ separation, Ca2+ was chosen as the model interfering ion, and effects of Ca2+ and Pb2+ initial concentration ratio (C0 Ca : C0 Pb) on the adsorption of Pb2+ were investigated. Results showed that adsorption amount ratio of Ca2+ and Pb2+ (qe Ca : qe Pb) had a good linear relationship with C0 Ca : C0 Pb. Mass ratio of Pb2+ absorbed on the modified SCB was higher than 95% at C0 Ca : C0 Pb<1.95, illustrating that Pb2+ could be selectively removed from aqueous solution. To verify that, simulated waste water containing co-ions of K+, Na+, Cd2+ and Ca2+ was treated, and results showed that the equilibrium amount of Pb2+, K+, Na+, Cd2+ and Ca2+ adsorbed was 134.14, 0.083, 0.058, 1.28, and 1.28mg g−1, respectively, demonstrating that the modified SCB could be used to remove Pb2+ from aqueous solution in the investigated range.

Artificial Intelligence in the Prediction of Gastrointestinal Stromal Tumors on Endoscopic Ultrasonography Images: Development, Validation and Comparison with Endosonographers

Lu Yi,Wu Jiachuan,Hu Minhui,Zhong Qinghua,Er Limian,Shi Huihui,Cheng Weihui,Chen Ke,Liu Yuan,Qiu Bingfeng,Xu Qiancheng,Lai Guangshun,Wang Yufeng,Luo Yuxuan,Mu Jinbao,Zhang Wenjie,Zhi Min,Sun Jiachen 거트앤리버 소화기연관학회협의회 2023 Gut and Liver Vol.17 No.6

Background/Aims: The accuracy of endosonographers in diagnosing gastric subepithelial lesions (SELs) using endoscopic ultrasonography (EUS) is influenced by experience and subjectivity. Artificial intelligence (AI) has achieved remarkable development in this field. This study aimed to develop an AI-based EUS diagnostic model for the diagnosis of SELs, and evaluated its efficacy with external validation. Methods: We developed the EUS-AI model with ResNeSt50 using EUS images from two hospitals to predict the histopathology of the gastric SELs originating from muscularis propria. The diagnostic performance of the model was also validated using EUS images obtained from four other hospitals. Results: A total of 2,057 images from 367 patients (375 SELs) were chosen to build the models, and 914 images from 106 patients (108 SELs) were chosen for external validation. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the model for differentiating gastrointestinal stromal tumors (GISTs) and non-GISTs in the external validation sets by images were 82.01%, 68.22%, 86.77%, 59.86%, and 78.12%, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in the external validation set by tumors were 83.75%, 71.43%, 89.33%, 60.61%, and 80.56%, respectively. The EUS-AI model showed better performance (especially specificity) than some endosonographers. The model helped improve the sensitivity, specificity, and accuracy of certain endosonographers. Conclusions: We developed an EUS-AI model to classify gastric SELs originating from muscularis propria into GISTs and non-GISTs with good accuracy. The model may help improve the diagnostic performance of endosonographers. Further work is required to develop a multi-modal EUS-AI system.