Constitutive modeling for path-dependent behavior and its influence on twist springback

Liao, Juan,Xue, Xin,Lee, Myoung-Gyu,Barlat, Fré,dé,ric,Vincze, Gabriela,Pereira, Antó,nio B. Elsevier 2017 International journal of plasticity Vol.93 No.-

<P><B>Abstract</B></P> <P>The aim of this study is to investigate the path-dependent elastic-plastic behavior of dual-phase steel and its influence on the prediction of twist springback in the channel forming process. The anisotropic hardening responses of the sheet material for non-proportional loading, as well as the degradation of the elastic modulus in uniaxial and biaxial tension are investigated. A recently proposed distortional plasticity model combined with a dislocation density-based hardening approach was adopted to describe the flow behavior of the material. The results indicate that the present model simultaneously reproduces all of the experimentally observed features for both load reversal and changes of the principal strain axis. This constitutive description is employed in the finite element analysis of the forming of two channels with obvious twist springback characteristics. The complex strain path changes during the forming process are then analyzed using a proposed indicator. Finally, the relevance of the load changes and the stress distribution in the channel regarding twist springback predictions are discussed. The influence of loading path-dependent elastic modulus degradation for the prediction of twist springback is also assessed based on two different application geometries.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The enhanced HAH model captures DP500's plastic flow behavior at various strain path changes. </LI> <LI> Hardening model affects twist springback prediction in sheet forming. </LI> <LI> A proposed indicator represents well the complex loading path history. </LI> <LI> The influence of strain path changes other than pure load reversal is assessed. </LI> <LI> Path-dependent elastic behavior and its influence on twist springback are studied. </LI> </UL> </P>

Energy efficiency characteristic analysis of tri‑coil PT symmetric MC‑WPT systems

Zhi-Juan Liao,Qi-Wei Zhu,Wen Ren,Chen-Yang Xia,Xu Liu 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.9

The parity-time (PT) symmetric magnetic coupling wireless power transfer (MC-WPT) system has received a great deal of attention since it was proposed. Its transmission efficiency has been greatly improved when compared with previous research. The operational amplifier (OA) is a typical construction method for PT symmetric MC-WPT systems. On this basis, to achieve a higher transmission efficiency and a longer effective power transmission distance at the same time, this paper constructs an OA-based tri-coil PT symmetric MC-WPT system. The analytical expressions of its singularity, PT symmetric state, and PT symmetric broken state are obtained. Then a complete set of parameter design criteria for the tri-coil PT symmetric system is derived. The transmission efficiency and resonant frequency of two-coil and tri-coil system are simulated on MATLAB software, and the simulation results are consistent with the theoretical analysis results. Finally, an experimental device is constructed to further verify the correctness of the theory. This paper demonstrates that the effective power transmission distance of the tri-coil PT symmetric MC-WPT system is more than twice that of the two-coil PT symmetric MC-WPT system, which can achieve a good balance between transmission efficiency and transmission distance.

Realistic FDTD Simulations of Plasmonic Properties on Ag Columnar Thin Films as SERS Biosensor

Yan-Juan Liao,Jing-Nan Huang,Jia-Yang Guo,Shao-Ji Jiang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.10

Noble metal sculptured thin films are of great interest during last decade as excellent surfaceenhanced Raman scattering (SERS) substrates due to remarkable plasmonic properties in the visible and near-infrared range. In this work, Ag columnar thin films (Ag-CTFs) have been prepared by the glancing angle deposition technique. Finite-difference time-domain simulations has been utilized to study plasmonic properties of Ag-CTFs with a more accurate model based on binary scanning electron microscope (SEM) images by taking account of the shape irregularities, size distributions and random arrangement. The calculated absorption spectra based on the model of binarized SEM images show the best agreement with the measured spectra compared with models of periodic array with a regular shape. The near-field plasmonic properties are simulated based on the verified model. The distributions of electric field enhancement and hot spots are confirmed to be spectral and polarization dependent. There are multiple resonance peaks from visible to near-infrared and multiple eigenmodes coexist at the same wavelength and electric field enhancement are mainly excited by the polarized light vertical to the gap orientation. The electric field enhancement is found to distribute unevenly in the films with surface-localized feature. The equations to calculate the simulation SERS enhancement factor (EF) and total number of hot spots (tHN) are modified according to the above discussions. The experimental SERS EFs are on the order of 107 – 108 , which indicates the high sensitivity of the films and the simulation SERS EFs and tHNs show good agreement with the experimental EFs. It is found that the SERS performance of Ag-CTFs is decided by both the cross-section structural characteristics and film thickness, which affect the electric filed enhancement and number of adsorbed molecules, respectively. Our work could be helpful in understanding the SERS mechanism and useful to the optimization of metal sculptured thin films for designing SERS biosensor.

Augmenter of Liver Regeneration Alleviates Renal Hypoxia-Reoxygenation Injury by Regulating Mitochondrial Dynamics in Renal Tubular Epithelial Cells

Xiao-hui Liao,Rui-ting Long,Jun-bo Peng,Li-li Huang,Gui-ping Jiang,Yue-juan Liao,Hang Sun,Yu-dong Hu 한국분자세포생물학회 2019 Molecules and cells Vol.42 No.12

Mitochondria are highly dynamic organelles that constantly undergo fission and fusion processes that closely related to their function. Disruption of mitochondrial dynamics has been demonstrated in acute kidney injury (AKI), which could eventually result in cell injury and death. Previously, we reported that augmenter of liver regeneration (ALR) alleviates renal tubular epithelial cell injury. Here, we gained further insights into whether the renoprotective roles of ALR are associated with mitochondrial dynamics. Changes in mitochondrial dynamics were examined in experimental models of renal ischemia-reperfusion (IR). In a model of hypoxia-reoxygenation (HR) injury in vitro, dynamin-related protein 1 (Drp1) and mitochondrial fission process protein 1 (MTFP1), two key proteins of mitochondrial fission, were downregulated in the Lv-ALR + HR group. ALR overexpression additionally had an impact on phosphorylation of Drp1 Ser637 during AKI. The inner membrane fusion protein, Optic Atrophy 1 (OPA1), was significantly increased whereas levels of outer membrane fusion proteins Mitofusin-1 and -2 (Mfn1, Mfn2) were not affected in the Lv-ALR + HR group, compared with the control group. Furthermore, the mTOR/4E-BP1 signaling pathway was highly activated in the Lv-ALR + HR group. ALR overexpression led to suppression of HR-induced apoptosis. Our collective findings indicate that ALR gene transfection alleviates mitochondrial injury, possibly through inhibiting fission and promoting fusion of the mitochondrial inner membrane, both of which contribute to reduction of HK-2 cell apoptosis. Additionally, fission processes are potentially mediated by promoting tubular cell survival through activating the mTOR/4E-BP1 signaling pathway.

A New Practical System for Evaluating the Pharmacological Properties of Uricase as a Potential Drug for Hyperuricemia

Juan Feng,Xiang Li,Xiaolan Yang,Chun Zhang,Yonghua Yuan,Jun Pu,Yunsheng Zhao,Yanling Xie,Huidong Yuan,Youquan Bu,Fei Liao 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.11

The use of uricase-deficient mammals to screen formulations of engineered uricases as potential drugs for hyperuricemia involves heavy costs and presents a technical bottleneck. Herein, a new practical system was investigated to evaluate the pharmacological significance of a bacterial uricase based on its ability to eliminate uric acid in plasma in vitro, its pharmacokinetics in vivo in healthy rats, and the modeled pharmacodynamics in vivo. This uricase, before and after modification with the monomethyl ether of poly(ethylene glycol)-5000, effectively eliminated uric acid in vitro in rabbit plasma, but its action was susceptible to xanthine inhibition. After intravenous injection of the modified uricase without purification, a bi-exponential model fit well to uricase activities in vivo in the plasma of healthy rats; the half-life of the modified uricase was estimated without interference from the unmodified uricase leftover in the sample and was nearly 100-fold longer than that of the unmodified uricase. Using a model of the elimination of uric acid in vivo taking into account of uricase pharmacokinetics and xanthine inhibition, modeled pharmacodynamics supported that the half-life of uricase and its susceptibility to xanthine are crucial for the pharmacological significance of uricase. Hence,this practical system is desirable for doing preliminary screening of formulations of engineered uricases as potential drugs for hyperuricemia.

Preparation and properties of the green-emitting phosphors NaCa0.98-xMgxPO4:

Bo Yue,Juan Gu,Guangfu Yin,Zhongbing Huang,Xiaoming Liao,Yadong Yao,Yunqing Kang,Panli You 한국물리학회 2010 Current Applied Physics Vol.10 No.4

In this study, a series of the green-emitting phosphors NaCa0.98-xMgxPO4:Eu2þ 0:02 was prepared through high temperature solid-state reaction. The structure and spectroscopic properties of these samples were characterized by XRD, FT-IR, reflectance spectra and photoluminescence (PL) spectra, respectively. The effect of Mg2+ co-doping concentration on the PL intensity of as-prepared samples was also investigated. The enhanced intensities of excitation and emission band of Eu2+ and a slight red-shift of the emission peak were observed due to Mg2+ co-doping. When the x value is 0.08, the phosphors possessed the maximum emission intensity monitored at 360 nm and the emission spectrum shows a single band centered at about 500 nm. The obtained phosphors had strong absorption in near-UV zone (350–400 nm), which can match the emission of near-UV light-emitting diodes. The prepared material is potential green phosphors for white LEDs.

Pseudomyogenic Hemangioendothelioma in a 30-Year-Old Man: A Rare Case Report

( Chao-yu Liao ),( Chao-kuei Juan ),( Chi-shun Yang ),( Yi-ju Chen ) 대한피부과학회 2019 Annals of Dermatology Vol.31 No.5

A Method of Springback Prediction and Tool Shape Compensation for Multi-curvature Sheet Metal Bending

Chi Zhou,Juan Liao,Yin Zhu,Zhenjiao Chen 한국소성가공학회 2010 기타자료 Vol.2010 No.6

Advanced High Strength Steels (AHSS) are used increasingly in automobile structure parts to reduce the vehicle weight while keeping the safety standard. But their high values of the ratio of strength to Young’s modulus cause more springback problems. A method of calculating the compensated tool shape for complex bending shapes is proposed in this paper. The method is composed of 3 steps: firstly the cross-section profile of a part was discretized into points and their corresponding curvatures; then an analytic algorithm based on plastic bending theory is applied to calculate the compensated curvatures of each point; finally, a numerical algorithm based on differential geometry is used to construct the tool shape according to the compensated curvatures of each point. A wave-shaped AHSS part with three different curvatures had been used to evaluate this method. The experimental results showed that the max curvature variance between the actual bending parts and desired shape is less than 4%, which is satisfying for most engineering applications.

Efficacy of Taxane-Based Regimens in a First-line Setting for Recurrent and/or Metastatic Chinese Patients with Esophageal Cancer

Jiang, Chang,Liao, Fang-Xin,Rong, Yu-Ming,Yang, Qiong,Yin, Chen-Xi,He, Wen-Zhuo,Cai, Xiu-Yu,Guo, Gui-Fang,Qiu, Hui-Juan,Chen, Xu-Xian,Zhang, Bei,Xia, Liang-Ping Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.13

Objective: To compare the efficacy of taxane-based regimens in the first line setting retrospectively in Chinese patients with recurrent and/or metastatic esophageal cancer. Methods: We analyzed 102 recurrent and/or metastatic esophageal cancer patients who received taxanes-based regimens in a first-line setting from January 2009 to December 2013. Sixteen (15.7%) patients were administered Nab-PTX based chemotherapy and 86 patients (84.3%) received paclitaxel (PTX) or docetaxel (DTX) based chemotherapy. Patients in the PTX/DTX group could be further divided into TP (71 patients) and TPF (15 patients) groups. Results: The objective response rate (ORR) of all patients was 20.6%, and the disease control rate (DCR) was 67.6%. The median overall survival (OS) was 10.5 months (95% CI 10.1-16.4) and the median progression-free survival (PFS) was 6.04 months (95% CI 5.09-7.91). The DCR was higher in the TPF group than the TP group (93.3% vs. 59.1%; p = 0.015 ). There were no significant differences in ORR, OS, and PFS among Nab-PTX, TPF and TP groups. Conclusions: The three regimens of Nab-PTX based, TP and TPF proved active in a first line setting of Chinese patients with recurrent and/or metastatic esophageal cancer, and should thus be regarded as alternative treatments.

High Performance Spatial and Temporal Error-Concealment Algorithms for Block-Based Video Coding Techniques

Ching-Ting Hsu,Mei-Juan Chen,Wen-Wei Liao,Shen-Yi Lo 한국전자통신연구원 2005 ETRI Journal Vol.27 No.1

A compressed video bitstream is sensitive to errors that may severely degrade the reconstructed images even when the bit error rate is small. One approach to combat the impact of such errors is the use of error concealment at the decoder without increasing the bit rate or changing the encoder. For spatial-error concealment, we propose a method featuring edge continuity and texture preservation as well as low computation to reconstruct more visually acceptable images. Aiming at temporal error concealment, we propose a two-step algorithm based on block matching principles in which the assumption of smooth and uniform motion for some adjacent blocks is adopted. As simulation results show, the proposed spatial and temporal methods provide better reconstruction quality for damaged images than other methods.