Determination of Dimensional Profile and Heat Input of Welded Joint with Average Temperature

Jiangchao Wang 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.4

With the proposal of the average temperature concept, the target of this study is to determine the appropriate dimensional profile and heat input for butt welded joints. Meanwhile, inherent deformation as the cause of welding distortion was examined to confirm the dimensional profile and heat input of welded joints for reliable welding experiments. First, butt welding experiment and measurement of out-of-plane welding distortion were conducted. The effect of length and width of welded joint on longitudinal shrinkage force was numerically considered and examined with a series of thermal elastic plastic finite element computations, where the mechanism of this behavior was clarified with average temperature. The case of heat input increasing was also examined with average temperature, which can be considered as the identical heat input for plate width decreasing. Moreover, the difference between theoretical and computational approaches to evaluate longitudinal shrinkage force was perfectly clarified with the concept of average temperature, and dimensional profile and heat input of butt welded joints were suggested.

Computational analysis of welding radial deformation of typical pressure cylindrical shell with ring stiffener

Zhou Hong,Shen Chaonan,Wang Jiangchao 대한조선학회 2022 International Journal of Naval Architecture and Oc Vol.14 No.1

We report on the evaluation of the radial deformation caused by the welding process on a typical pressure cylindrical shell with ring stiffeners. Welding experiments on butt and fillet welding were conducted beforehand, and temperature-dependent material properties were considered. The out-ofplane welding distortion and residual stress were measured using a three-coordinate measuring machine and X-ray diffraction, respectively. Effective thermal elastic plastic FE analysis based on parallel computation technology was performed to examine the mechanical behaviors. Computed results were validated by comparison with experimental measurements. Welding inherent deformations of the examined butt and fillet joints were then evaluated by integrating computed plastic strains. The elastic FE analysis, with welding inherent deformation as mechanical loading, was employed to examine the dimensional variation of the considered pressure cylindrical shell. The influence of ring stiffener on welding radial deformation was also discussed. Moreover, the application of welding sequence modification and inverse deformation was numerically examined with the proposed elastic FE analysis to reduce the welding radial deformation and enhance the fabrication accuracy.

Effects of dietary fibers, micronutrients, and phytonutrients on gut microbiome: a review

Beane Kaleigh E.,Redding Mersady C.,Wang Xiaofan,Pan Jeong Hoon,Le Brandy,Cicalo Cara,Jeon Suwon,Kim Young Jun,Lee Jin Hyup,Shin Eui-Cheol,Li Ying,Zhao Jiangchao,Kim Jae Kyeom 한국응용생명화학회 2021 Applied Biological Chemistry (Appl Biol Chem) Vol.64 No.2

The human gastrointestinal tract harbors a magnitude of bacteria, which are collectively known as the gut microbiome. Research has demonstrated that the gut microbiome significantly impacts the health of its host and alters the host’s risk for various chronic diseases. Many factors, such as diet, could potentially be manipulated to alter the host gut microbiome and induce subsequent preventative and/or therapeutic effects. It has been established that diet partakes in the regulation and maintenance of the gut microbiome; however, specific crosstalk between the microbiome, gut, and host has not been clearly elucidated in relation to diet. In this review of the scientific literature, we outline current knowledge of the differential effects of major plant-derived dietary constituents (fiber, phytochemicals, vitamins, and minerals) on the diversity and composition of the gut microbiome.

Hardness prediction based on microstructure evolution and residual stress evaluation during high tensile thick plate butt welding

Zhou, Hong,Zhang, Qingya,Yi, Bin,Wang, Jiangchao The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.-

Two High Tensile Strength Steel (EH47) plates with thickness of 70 mm were butt-welded together by multi-pass Submerged Arc Welding (SAW), also the hardness and welding residual stress were investigated experimentally. Based on Thermal-Elastic-Plastic Finite Element (TEP FE) computation, the thermal cycles during entire welding process were obtained, and the HAZ hardness of multi-pass butt welded joint was computed by the hardenability algorithm with considering microstructure evolution. Good agreement of HAZ hardness between the measurement and computational result is observed. The evolution of each phase was drawn to clarify the influence mechanism of thermal cycle on HAZ hardness. Welding residual stress was predicted with considering mechanical response, which was dominantly determined by last cap welds through analyzing its formation process.

Hardness prediction based on microstructure evolution and residual stress evaluation during high tensile thick plate butt welding

Zhou, Hong,Zhang, Qingya,Yi, Bin,Wang, Jiangchao The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.1

Two High Tensile Strength Steel (EH47) plates with thickness of 70 mm were butt-welded together by multi-pass Submerged Arc Welding (SAW), also the hardness and welding residual stress were investigated experimentally. Based on Thermal-Elastic-Plastic Finite Element (TEP FE) computation, the thermal cycles during entire welding process were obtained, and the HAZ hardness of multi-pass butt welded joint was computed by the hardenability algorithm with considering microstructure evolution. Good agreement of HAZ hardness between the measurement and computational result is observed. The evolution of each phase was drawn to clarify the influence mechanism of thermal cycle on HAZ hardness. Welding residual stress was predicted with considering mechanical response, which was dominantly determined by last cap welds through analyzing its formation process.

Glutamate attenuates lipopolysaccharide induced intestinal barrier injury by regulating corticotropin-releasing factor pathway in weaned pigs

Guo Junjie,Liang Tianzeng,Chen Huifu,Li Xiangen,Ren Xiaorui,Wang Xiuying,Xiao Kan,Zhao Jiangchao,Zhu Huiling,Liu Yulan 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.8

Objective: The purpose of this study was to evaluate the protection of glutamate (GLU) against the impairment in intestinal barrier function induced by lipopolysaccharide (LPS) stress in weaned pigs. Methods: Twenty-four weaned pigs were divided into four treatments containing: i) nonchallenged control, ii) LPS-challenged control, iii) LPS+1.0% GLU, and iv) LPS+2.0% GLU. On day 28, pigs were treated with LPS or saline. Blood samples were collected at 0, 2, and 4 h post-injection. After blood samples collection at 4 h, all pigs were slaughtered, and spleen, mesenteric lymph nodes, liver and intestinal samples were obtained. Results: Dietary GLU supplementation inhibited the LPS-induced oxidative stress in pigs, as demonstrated by reduced malondialdehyde level and increased glutathione level in jejunum. Diets supplemented with GLU enhanced villus height, villus height/crypt depth and claudin-1 expression, attenuated intestinal histology and ultrastructure impairment induced by LPS. Moreover, GLU supplementation reversed intestinal intraepithelial lymphocyte number decrease and mast cell number increase induced by LPS stress. GLU reduced serum cortisol concentration at 4 h after LPS stress and downregulated the mRNA expression of intestinal corticotropin-releasing factor signal (corticotrophin-releasing factor [CRF], CRF receptor 1 [CRFR1], glucocorticoid receptor, tryptase, nerve growth factor, tyrosine kinase receptor A), and prevented mast cell activation. GLU upregulated the mRNA expression of intestinal transforming growth factor β. Conclusion: These findings indicate that GLU attenuates LPS-induced intestinal mucosal barrier injury, which is associated with modulating CRF signaling pathway. Objective: The purpose of this study was to evaluate the protection of glutamate (GLU) against the impairment in intestinal barrier function induced by lipopolysaccharide (LPS) stress in weaned pigs.Methods: Twenty-four weaned pigs were divided into four treatments containing: i) non-challenged control, ii) LPS-challenged control, iii) LPS+1.0% GLU, and iv) LPS+2.0% GLU. On day 28, pigs were treated with LPS or saline. Blood samples were collected at 0, 2, and 4 h post-injection. After blood samples collection at 4 h, all pigs were slaughtered, and spleen, mesenteric lymph nodes, liver and intestinal samples were obtained.Results: Dietary GLU supplementation inhibited the LPS-induced oxidative stress in pigs, as demonstrated by reduced malondialdehyde level and increased glutathione level in jejunum. Diets supplemented with GLU enhanced villus height, villus height/crypt depth and claudin-1 expression, attenuated intestinal histology and ultrastructure impairment induced by LPS. Moreover, GLU supplementation reversed intestinal intraepithelial lymphocyte number decrease and mast cell number increase induced by LPS stress. GLU reduced serum cortisol concentration at 4 h after LPS stress and downregulated the mRNA expression of intestinal corticotropin-releasing factor signal (corticotrophin-releasing factor [<i>CRF</i>], CRF receptor 1 [<i>CRFR1</i>], glucocorticoid receptor, tryptase, nerve growth factor, tyrosine kinase receptor A), and prevented mast cell activation. GLU upregulated the mRNA expression of intestinal transforming growth factor β.Conclusion: These findings indicate that GLU attenuates LPS-induced intestinal mucosal barrier injury, which is associated with modulating CRF signaling pathway.