NEW RESEARCH AND DEVELOPMENT IN VIBRATION UTILIZATION ENGINEERING

Wen Bangchun,Li Yinong,Yan Shirong,Ma Zhiguo,Han Qinkai,Zhang Hong 한국소음진동공학회 1997 한국소음진동공학회 국제학술대회논문집 Vol.1997 No.1

Modeling of the polycrystalline cutting of austenitic stainless steel based on dislocation density theory and study of burr formation mechanism

Jiaxin Wen,Lin He,Tao Zhou,Pengfei Tian,Tian Zhou,Zhiguo Feng 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.6

The presence of burrs in mechanical processing can negatively affect surface integrity and dimensional accuracy and even lead to part scrapping. Grain size also has a significant impact on material properties and subsequently generate different processing effects. However, only few studies have explored the effect of grain size on machined surface integrity and burr formation. To fill this gap, this study develops a model based on dislocation density and incorporates this model into ABAQUS using subroutines to investigate polycrystalline cutting modeling and the burr formation mechanism. In addition, the plastic flow and deformation process of grains are observed using a newly developed 2D polycrystalline model, which is later compared with traditional Johnson-Cook constitutive models. The simulated cutting force value, chip morphology, and experimental results are also compared to preliminarily validate the feasibility of the developed model. The experimental results remain consistent across different simulated cutting speeds and depths. The height and width of the exit burr slightly decrease along with increasing cutting speed. Meanwhile, increasing the cutting depth significantly increases the burr width and height. The lateral burrs observed in the experiment can also be reproduced using a 3D polycrystalline model. The lateral burr size increases along with cutting depth and speed. The effect of grain size on cutting force and burr formation is eventually explored, and results show that increasing the grain size reduces the cutting force but increases the burr size. This study provides a new concept for burr control and surface integrity improvement.

New Research and Development in Vibration Utilization Engineering

Bang Chun Wen,Yi Nong Li,Shirong Yan,Zhiguo Ma,Qinkai Han,Hong Zhang 대한기계학회 1997 Asia-Pacific Vibration Conference Vol.1 No.1

Effects of Pyridoxine on Growth Performance and Plasma Aminotransferases and Homocysteine of White Pekin Ducks

Xie, Ming,Tang, Jing,Wen, Zhiguo,Huang, Wei,Hou, Shuisheng Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.12

A dose-response experiment with seven supplemental pyridoxine levels (0, 0.66, 1.32, 1.98, 2.64, 3.30, and 3.96 mg/kg) was conducted to investigate the effects of pyridoxine on growth performance and plasma aminotransferases and homocysteine of White Pekin ducks and to estimate pyridoxine requirement for these birds. A total of 336 one-day-old male White Pekin ducks were divided to 7 experimental treatments and each treatment contained 8 replicate pens with 6 birds per pen. Ducks were reared in raised wire-floor pens from hatch to 28 d of age. At 28 d of age, the weight gain, feed intake, feed/gain, and the aspartate aminotransferase, alanine aminotransferase, and homocysteine in plasma of ducks from each pen were all measured. In our study, the pyridoxine deficiency of ducks was characterized by growth depression, decreasing plasma aspartate aminotransferase activity and increasing plasma homocysteine. The ducks fed vitamin $B_6$-deficient basal diets had the worst weight gain and feed/gain among all birds and this growth depression was alleviated (p<0.05) when pyridoxine was supplemented to basal diets. On the other hand, plasma aspartate aminotransferase and homocysteine may be the sensitive indicators for vitamin $B_6$ status of ducks. The ducks fed basal diets had much lower aspartate aminotransferase activity and higher homocysteine level in plasma compared with other birds fed pyridoxine-supplemented diets (p<0.05). According to quadratic regression, the supplemental pyridoxine requirements of Pekin ducks from hatch to 28 days of age was 2.44 mg/kg for feed/gain and 2.08 mg/kg for plasma aspartate aminotransferase and the corresponding total requirements of this vitamin for these two criteria were 4.37 and 4.01 mg/kg when the pyridoxine concentration of basal diets was included, respectively. All data suggested that pyridoxine deficiency could cause growth retardation in ducks and the deficiency of this vitamin could be indicated by decreasing plasma aspartate aminotransferase activity and increasing plasma homocysteine.

Severe choline deficiency induces alternative splicing aberrance in optimized duck primary hepatocyte cultures

Zhao Lulu,Cai Hongying,Wu Yongbao,Tian Changfu,Wen Zhiguo,Yang Peilong 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.11

Objective: Choline deficiency, one main trigger for nonalcoholic fatty liver disease (NAFLD), is closely related to lipid metabolism disorder. Previous study in a choline-deficient model has largely focused on gene expression rather than gene structure, especially sparse are studies regarding to alternative splicing (AS). In modern life science research, primary hepatocytes culture technology facilitates such studies, which can accurately imitate liver activity in vitro and show unique superiority. Whereas limitations to traditional hepatocytes culture technology exist in terms of efficiency and operability. This study pursued an optimization culture method for duck primary hepatocytes to explore AS in choline-deficient model. Methods: We performed an optimization culture method for duck primary hepatocytes with multi-step digestion procedure from Pekin duck embryos. Subsequently a NAFLD model was constructed with choline-free medium. RNA-seq and further analysis by rMATS were performed to identify AS events alterations in choline-deficency duck primary hepatocytes. Results: The results showed E13 (embryonic day 13) to E15 is suitable to obtain hepatocytes, and the viability reached over 95% by trypan blue exclusion assay. Primary hepatocyte retained their biological function as well identified by Periodic Acid-Schiff staining method and Glucose-6-phosphate dehydrogenase activity assay, respectively. Meanwhile, genes of alb and afp and specific protein of albumin were detected to verify cultured hepatocytes. Immunofluorescence was used to evaluate purity of hepatocytes, presenting up to 90%. On this base, choline-deficient model was constructed and displayed significantly increase of intracellular triglyceride and cholesterol as reported previously. Intriguingly, our data suggested that AS events in choline-deficient model were implicated in pivotal biological processes as an aberrant transcriptional regulator, of which 16 genes were involved in lipid metabolism and highly enriched in glycerophospholipid metabolism. Conclusion: An effective and rapid protocol for obtaining duck primary hepatocytes was established, by which our findings manifested choline deficiency could induce the accumulation of lipid and result in aberrant AS events in hepatocytes, providing a novel insight into various AS in the metabolism role of choline. Objective: Choline deficiency, one main trigger for nonalcoholic fatty liver disease (NAFLD), is closely related to lipid metabolism disorder. Previous study in a choline-deficient model has largely focused on gene expression rather than gene structure, especially sparse are studies regarding to alternative splicing (AS). In modern life science research, primary hepatocytes culture technology facilitates such studies, which can accurately imitate liver activity <i>in vitro</i> and show unique superiority. Whereas limitations to traditional hepatocytes culture technology exist in terms of efficiency and operability. This study pursued an optimization culture method for duck primary hepatocytes to explore AS in choline-deficient model.Methods: We performed an optimization culture method for duck primary hepatocytes with multi-step digestion procedure from Pekin duck embryos. Subsequently a NAFLD model was constructed with choline-free medium. RNA-seq and further analysis by rMATS were performed to identify AS events alterations in choline-deficency duck primary hepatocytes.Results: The results showed E13 (embryonic day 13) to E15 is suitable to obtain hepatocytes, and the viability reached over 95% by trypan blue exclusion assay. Primary hepatocyte retained their biological function as well identified by Periodic Acid-Schiff staining method and Glucose-6-phosphate dehydrogenase activity assay, respectively. Meanwhile, genes of <i>alb</i> and <i>afp</i> and specific protein of albumin were detected to verify cultured hepatocytes. Immunofluorescence was used to evaluate purity of hepatocytes, presenting up to 90%. On this base, choline-deficient model was constructed and displayed significantly increase of intracellular triglyceride and cholesterol as reported previously. Intriguingly, our data suggested that AS events in choline-deficient model were implicated in pivotal biological processes as an aberrant transcriptional regulator, of which 16 genes were involved in lipid metabolism and highly enriched in glycerophospholipid metabolism.Conclusion: An effective and rapid protocol for obtaining duck primary hepatocytes was established, by which our findings manifested choline deficiency could induce the accumulation of lipid and result in aberrant AS events in hepatocytes, providing a novel insight into various AS in the metabolism role of choline.