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Hot Deformation Characteristics and Processing Map Analysis of Pre-Forged AZ80 Magnesium Alloy
Shi‑quan Huang,Ming Lu,Sheng‑lan Luo,Hai‑lin He,You‑ping Yi 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5
The hot deformation behavior of pre-forged AZ80 magnesium alloy is investigated by the isothermal compression tests attemperatures of 523–683 K and strain rates of 0.0001–0.1 s−1, and analyzed by the processing maps for guiding isothermaldie forging. Flow localization and even cracking occurs at low temperatures and high strain rates, where shear deformationdegree shows a positive correlation with the ��( ̇�� ) value. Two stability regions with high efficiency is found out by theprocessing maps. At common stability region with high temperatures and low strain rates, peak power dissipation efficiencydoes not represent optimum deformation condition as reported in other materials. A Z parameter criterion is introduced forparameters optimization. javascript:void(0); a new stability domain of 523–590 K and 0.0001–0.01 s−1 is observed, which istypical for fine microstructure composed of equiaxed clean α-Mg grains and big particles both about 1 μm (573 K/0.01 s−1).Super plasticity is speculated to occur at that condition.
Quan, Fu-Shi,Jeong, Kyung Hwan,Lee, Gi-Ja Elsevier 2018 Micron Vol.110 No.-
<P><B>Abstract</B></P> <P>Tubular epithelial cells (TECs) play an important pathophysiological role in the promotion of renal fibrosis. Quantitative analysis of the mechanical changes in TECs may be helpful in evaluating novel pharmacological strategies. Atomic force microscopy (AFM) is a common nanotechnology tool used for imaging and measuring interaction forces in biological systems. In this study, we used AFM to study ultrastructural and mechanical changes in TECs mediated by the renin-angiotensin-aldosterone system. We quantitatively analyzed changes in the mechanical properties of TECs using three extrinsic factors, namely, chemical fixation, angiotensin II (AT II), and aldosterone (AD). Fixed TECs were 11 times stiffer at the cell body and 3 times stiffer at the cell–cell junction compared to live TECs. After stimulation with AT II, live TECs were four times stiffer at the junctional area than at the cell body, while fixed TECs after AT II stimulation were approximately two times stiffer at the both cell body and cell–cell junction compared to fixed unstimulated TECs. Fixed TECs also reflected changes in the mechanical properties of TECs at the cell body region after AD stimulation. Together, our results suggest that cell stiffness at the cell body region may serve as an effective index for evaluating drugs and stimulation, regardless of whether the cells are live or fixed at the time of analysis. In addition, studying the changes to the intrinsic mechanical property of TECs after application of external stimuli may be useful for investigating pathophysiologic mechanisms and effective therapeutic strategies for renal injury.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We quantitatively analyzed the ultrastructure and mechanical changes in TECs. </LI> <LI> Three extrinsic factors including chemical fixation, AT II and AD treatments were used. </LI> <LI> The mechanical changes in fixed cells after stimuli can reflect those of live cells in cell body region. </LI> <LI> Cell stiffness at cell body region can be utilized as effective index for the evaluation of stimulation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Quan, Yan-Shi,Naruse, Kenji,Kim, Baek-Chul,Kim, Hong-Rye,Han, Rang-Xun,Choi, Su-Min,Park, Chang-Sik,Jin, Dong-Il The Korean Society of Animal Reproduction 2007 Reproductive & developmental biology Vol.31 No.4
Insulin, transferrin and selenium (ITS) complex is reported to improve in vitro development of oocytes and embryos. This study was carried out to investigate the effects of ITS during in vitro culture (IVC) of porcine parthenogenetic and nuclear transfer (NT) embryos on subsequent developmental capacity in vitro. The electrically activated oocytes were cultured in Porcine Zygote Medium (PZM-3) with various concentrations (0, 0.1, 0.5, and 1.0%) of ITS for 7 days. Also, the electrically activated reconstructed embryos were cultured in PZM-3 with various concentrations (0, 0.1, 0.5, and 1.0%) of ITS for 6 days. Addition of ITS to culture medium did not affect development of porcine parthenogenetic embryos in vitro. To test the effect of ITS on the in vitro development of porcine NT embryos, factorial experiments were also performed for in vitro maturation (IVM) medium (TCM-199) with or without 1% ITS and culture medium (PZM-3) with or without 0.5% ITS. Addition of 0.5% ITS to culture medium increased (p<0.05) the proportion of NT blastocysts compared with non-treated group. In contrast, addition of 1% ITS to culture medium was ineffective or had a detrimental effect. Also, addition of ITS only to maturation medium increased (p<0.05) the percentage of NT blastocysts formation compared with the control group. In conclusion, addition of ITS to IVM or IVC medium could improve subsequent blastocyst development of porcine NT embryos.
Quan, Yan Shi,Naruse, Kenji,Choi, Su-Min,Kim, Myung-Youn,Han, Rong-Xun,Park, Chang-Sik,Jin, Dong-Il The Korean Society of Animal Reproduction 2008 Reproductive & developmental biology Vol.32 No.4
Interspecies somatic cell nuclear transfer (iSCNT) is a valuable tool for studying the interactions between an oocyte and somatic nucleus. The object of this study was to investigate the developmental competence of in vitro-matured porcine oocytes after transfer of the somatic cell nuclei of 2 different species (goat and rabbit). Porcine cumulus oocytes were obtained from the follicles of ovaries and matured in TCM-199. The reconstructed embryos were electrically fused with 2 DC pulses of 1.1kV/cm for $30{\mu}s$ 0.3M mannitol medium. The activated cloned embryos were cultured in porcine zygote medium-3 (PZM-3), mSOF or RDH medium for 7 days. The blastocyst formation rate of the embryos reconstructed from goat or rabbit fetal fibroblasts was significantly lower than that of the embryos reconstructed from porcine fetal fibroblast cells. However, a significantly higher number of embryos reconstructed from goat or rabbit fetal fibroblasts cultured in mSOF or RDH, respectively, developed to the morular stage than those cultured in PZM-3. These results suggest that goat and bovine fetal fibroblasts were less efficacious than porcine-porcine cloned embryos and that culture condition could be an important factor in iSCNT. The lower developmental potential of goat-porcine and porcine-bovine cloned embryos may be due to incompatibility between the porcine oocyte cytoplasm and goat and bovine somatic nuclei.
Quan, Shi-Li,Kang, Soon-Gon,Qiu, Zhi-Cheng,Chen, Si-Chong,Yang, Ke-Ke,Wang, Yu-Zhong,Chin, In-Joo American Scientific Publishers 2011 Journal of nanoscience and nanotechnology Vol.11 No.2
<P>PPDO was successfully electrospun into continuous, ultrafine fibers by using DMSO as solvent for the first time. The concentration of PPDO in DMSO and the electrospinning temperature were optimized. PPDO/LAP nanocomposites were also electrospun in DMSO. At 70 degrees C, ultrafine PPDO fibers were obtained from 35 wt% solution and the PPDO/LAP nanocomposite fibers were yielded from 55 wt% solution. Electrospun fibers of the PPDO/LAP nanocomposites showed higher degree of crystallinity due to the presence of embedded nanoparticles.</P>
Simulation of 7050 Wrought Aluminum Alloy Wheel Die Forging and its Defects Analysis based on DEFORM
HUANG Shi-Quan,YI You-Ping,ZHANG Yu-Xun 한국소성가공학회 2010 기타자료 Vol.2010 No.6
Defects such as folding, intercrystalline cracking and flow lines outcrop are very likely to occur in the forging of aluminum alloy. Moreover, it is difficult to achieve the optimal set of process parameters just by trial and error within an industrial environment. In producing 7050 wrought aluminum alloy wheel, a rigid-plastic finite element method (FEM) analysis has been performed to optimize die forging process. Processing parameters were analyzed, focusing on the effects of punch speed, friction factor and temperature. Meanwhile, mechanism as well as the evolution with respect to the defects of the wrought wheel was studied in details. From an analysis of the results, isothermal die forging was proposed for producing 7050 aluminum alloy wheel with good mechanical properties. Finally, verification experiment was carried out on hydropress.
Yan Shi Quan,Kenji Naruse,Baek Chul Kim,Hong Rye Kim,Rong Xun Han,Su Min Choi,Chang Sik Park,Dong Il Jin 한국동물생명공학회(구 한국동물번식학회) 2007 Reproductive & developmental biology Vol.31 No.4
Insulin, transferrin and selenium (ITS) complex is reported to improve in vitro development of oocytes and embryos. This study was carried out to investigate the effects of ITS during in vitro culture (IVC) of porcine parthenogenetic and nuclear transfer (NT) embryos on subsequent developmental capacity in vitro. The electrically activated oocytes were cultured in Porcine Zygote Medium (PZM-3) with various concentrations (0, 0.1, 0.5, and 1.0%) of ITS for 7 days. Also, the electrically activated reconstructed embryos were cultured in PZM-3 with various concentrations (0, 0.1, 0.5, and 1.0%) of ITS for 6 days. Addition of ITS to culture medium did not affect development of porcine parthenogenetic embryos in vitro. To test the effect of ITS on the in vitro development of porcine NT embryos, factorial experiments were also performed for in vitro maturation (IVM) medium (TCM-199) with or without 1% ITS and culture medium (PZM-3) with or without 0.5% ITS. Addition of 0.5% ITS to culture medium increased (p<0.05) the proportion of NT blastocysts compared with non-treated group. In contrast, addition of 1% ITS to culture medium was ineffective or had a detrimental effect. Also, addition of ITS only to maturation medium increased (p<0.05) the percentage of NT blastocysts formation compared with the control group. In conclusion, addition of ITS to IVM or IVC medium could improve subsequent blastocyst development of porcine NT embryos.
Yan Shi Quan,Kenji Naruse,Su Min Choi,Myung Youn Kim,Rong Xun Han,Chang Sik Park,Dong Il Jin 한국동물생명공학회(구 한국동물번식학회) 2008 Reproductive & developmental biology Vol.32 No.4
Interspecies somatic cell nuclear transfer (iSCNT) is a valuable tool for studying the interactions between an oocyte and somatic nucleus. The object of this study was to investigate the developmental competence of in vitro‐matured porcine oocytes after transfer of the somatic cell nuclei of 2 different species (goat and rabbit). Porcine cumulus oocytes were obtained from the follicles of ovaries and matured in TCM‐199. The reconstructed embryos were electrically fused with 2 DC pulses of 1.1 kV/cm for 30 μs in 0.3 M mannitol medium. The activated cloned embryos were cultured in porcine zygote medium‐3 (PZM‐3), mSOF or RDH medium for 7 days. The blastocyst formation rate of the embryos reconstructed from goat or rabbit fetal fibroblasts was significantly lower than that of the embryos reconstructed from porcine fetal fibroblast cells. However, a significantly higher number of embryos reconstructed from goat or rabbit fetal fibroblasts cultured in mSOF or RDH, respectively, developed to the morular stage than those cultured in PZM‐3. These results suggest that goat and bovine fetal fibroblasts were less efficacious than porcine‐porcine cloned embryos and that culture condition could be an important factor in iSCNT. The lower developmental potential of goat‐porcine and porcine‐bovine cloned embryos may be due to incompatibility between the porcine oocyte cytoplasm and goat and bovine somatic nuclei.