Influence of Carbon Fiber on Corrosion Behavior of Carbon Steel in Simulated Concrete Pore Solutions

( Yuming Tang ),( Yuchao Dun ),( Guodong Zhang ),( Xuhui Zhao ),( Yu Zuo ) 한국부식방식학회(구 한국부식학회) 2017 Corrosion Science and Technology Vol.16 No.4

Galvanic current measurement, polarization curves, electrochemical impedance spectroscopy and weight loss test were used to study the corrosion behavior of carbon steel before and after carbon fibers coupling to the carbon steel in simulated concrete pore solutions, and the film composition on the steel surface was analyzed using XPS method. The results indicate that passive film on steel surface had excellent protective property in pore solutions with different pH values (13.3, 12.5 and 11.6). After coupling with carbon fibers the area ratio of carbon steel to carbon fiber was 12.31), charge transfer resistance Rct of the steel surface decreased and the Fe3+/Fe2+ value in passive film decreased. As a result, stability of the film decreased and the corrosion rate of steel increased. Decreasing of the area ratio of steel to carbon fiber from 12.3 to 6.15 resulted in the decrease in Rct and the increase in corrosion rate. Especially in the pore solution with pH 11.6, the coupling leads the carbon steel to corrode easily.

Gate driver for parallel connection SiC MOSFETs with over-current protection and dynamic current balancing scheme

Zhang, Yimeng,Song, Qingwen,Tang, Xiaoyan,Zhang, Yuming The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.1

In this paper, a SiC MOSFETs gate driver for parallel connections is proposed and implemented. The proposed design enhances the reliability of parallel-connected SiC MOSFETs in high-frequency applications. High-speed over-current protections are applied for both over-voltage and under-voltage situations. In addition, a dynamic balancing current sharing scheme for SiC MOSFETs is proposed for high-speed parallel applications by current feedback and switching delay time compensation. With the proposed design, parallel-connected SiC MOSFETs can work at an operation frequency of 1 MHz with over-current protections. In addition, with the dynamic current balancing scheme, the operation temperature decreases from 115 to 86.9 ℃, while the temperature difference for paralleled devices drops from 25.8 to 1.8 ℃.

Analysis of Clostridium Cluster I Community Diversity in Pit Mud Used in Manufacture of Chinese Luzhou-flavor Liquor

Maoke Liu,Ke Zhao,Yuming Tang,Daoqun Ren,Wanchun Yao,Xinhui Tian,Xinyu Zhang,Bin Yi,Bo Deng 한국식품과학회 2015 Food Science and Biotechnology Vol.24 No.3

Chinese Luzhou-flavor liquor is prepared using distillation of mixed, fermented grains, such as sorghum and rice. Fermentation occurs in cellars lined with pit mud containing microbes. The identity and community diversity of bacteria in pit mud of fermentation cellars contributes to the aromatic compounds of the liquor. In order to determine the contribution of genus Clostridium to this fermentation, the community diversity of Clostridium cluster I in pit mud of different cellar ages (1, 50, 100, and 400 years) was investigated based on denaturing gradient gel electrophoresis followed by 16S rRNA sequencing. Differences in the community structure within pit mud depended on wall and bottom layer cellar locations. A better understanding of the role of Clostridium in Luzhou-flavor liquor manufacture will be useful.

Toll-like receptor 4/nuclear factor-kappa B pathway is involved in radicular pain by encouraging spinal microglia activation and inflammatory response in a rat model of lumbar disc herniation

( Lirong Zhu ),( Yangliang Huang ),( Yuming Hu ),( Qian Tang ),( Yi Zhong ) 대한통증학회 2021 The Korean Journal of Pain Vol.34 No.1

Background: Lumbar disc herniation (LDH) is a common cause of radicular pain, but the mechanism is not clear. In this study, we investigated the engagement of toll-like receptor 4 (TLR4) and the nuclear factor-kappa B (NF-κB) in radicular pain and its possible mechanisms. Methods: An LDH model was induced by autologous nucleus pulposus (NP) implantation, which was obtained from coccygeal vertebra, then relocated in the lumbar 4/5 spinal nerve roots of rats. Mechanical and thermal pain behaviors were assessed by using von Frey filaments and hotplate test respectively. The protein level of TLR4 and phosphorylated-p65 (p-p65) was evaluated by western blotting analysis and immunofluorescence staining. Spinal microglia activation was evaluated by immunofluorescence staining of specific relevant markers. The expression of proand anti-inflammatory cytokines in the spinal dorsal horn was measured by enzyme linked immunosorbent assay. Results: Spinal expression of TLR4 and p-NF-κB (p-p65) was significantly increased after NP implantation, lasting up to 14 days. TLR4 was mainly expressed in spinal microglia, but not astrocytes or neurons. TLR4 antagonist TAK242 decreased spinal expression of p-p65. TAK242 or NF-κB inhibitor pyrrolidinedithiocarbamic acid alleviated mechanical and thermal pain behaviors, inhibited spinal microglia activation, moderated spinal inflammatory response manifested by decreasing interleukin (IL)- 1β, IL-6, tumor necrosis factor-α expression and increasing IL-10 expression in the spinal dorsal horn. Conclusions: The study revealed that TLR4/NF-κB pathway participated in radicular pain by encouraging spinal microglia activation and inflammatory response.

Dexamethasone enhances glucose uptake by SGLT1 and GLUT1 and boosts ATP generation through the PPP-TCA cycle in bovine neutrophils

Xinbo Wang,Mingyu Tang,Yuming Zhang,Yansong Li,Jingdong Mao,Qinghua Deng,Shusen Li,Zhenwei Jia,Liyin Du 대한수의학회 2022 Journal of Veterinary Science Vol.23 No.5

Background: Clinical dexamethasone (DEX) treatment or stress in bovines results in extensive physiological changes with prominent hyperglycemia and neutrophils dysfunction. Objectives: To elucidate the effects of DEX treatment in vivo on cellular energy status and the underlying mechanism in circulating neutrophils. Methods: We selected eight-month-old male bovines and injected DEX for 3 consecutive days (1 time/d). The levels of glucose, total protein (TP), total cholesterol (TC), and the proinflammatory cytokines interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α in blood were examined, and we then detected glycogen and adenosine triphosphate (ATP) content, phosphofructosekinase-1 (PFK1) and glucose-6-phosphate dehydrogenase (G6PDH) activity, glucose transporter (GLUT)1, GLUT4, sodium/glucose cotransporter (SGLT)1 and citrate synthase (CS) protein expression and autophagy levels in circulating neutrophils. Results: DEX injection markedly increased blood glucose, TP and TC levels, the Ca2+/P5+ ratio and the neutrophil/lymphocyte ratio and significantly decreased blood IL-1β, IL-6 and TNF-α levels. Particularly in neutrophils, DEX injection inhibited p65-NFκB activation and elevated glycogen and ATP contents and SGLT1, GLUT1 and GR expression while inhibiting PFK1 activity, enhancing G6PDH activity and CS expression and lowering cell autophagy levels. Conclusions: DEX induced neutrophils glucose uptake by enhancing SGLT1 and GLUT1 expression and the transformation of energy metabolism from glycolysis to pentose phosphate pathway (PPP)-tricarboxylic acid (TCA) cycle. This finding gives us a new perspective on deeper understanding of clinical anti-inflammatory effects of DEX on bovine.

Gear fault diagnosis under variable conditions with intrinsic time-scale decomposition-singular value decomposition and support vector machine

Zhanqiang Xing,Jianfeng Qu,Yi Chai,Qiu Tang,Yuming Zhou 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.2

The gear vibration signal is nonlinear and non-stationary, gear fault diagnosis under variable conditions has always been unsatisfactory. To solve this problem, an intelligent fault diagnosis method based on Intrinsic time-scale decomposition (ITD)-Singular value decomposition (SVD) and Support vector machine (SVM) is proposed in this paper. The ITD method is adopted to decompose the vibration signal of gearbox into several Proper rotation components (PRCs). Subsequently, the singular value decomposition is proposed to obtain the singular value vectors of the proper rotation components and improve the robustness of feature extraction under variable conditions. Finally, the Support vector machine is applied to classify the fault type of gear. According to the experimental results, the performance of ITD-SVD exceeds those of the time-frequency analysis methods with EMD and WPT combined with SVD for feature extraction, and the classifier of SVM outperforms those for K-nearest neighbors (K-NN) and Back propagation (BP). Moreover, the proposed approach can accurately diagnose and identify different fault types of gear under variable conditions.

Novel modulation method for torque ripple suppression of brushless DC motors based on SIMO DC-DC converter

Sun, Shikai,Guo, Hui,Zhang, Yimeng,Jia, Yupeng,Lv, Hongliang,Song, Qingwen,Tang, Xiaoyan,Zhang, Yuming The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.3

In this paper, a novel modulation method is proposed for the torque ripple suppression of a brushless DC motor (BLDCM) during both the commutation period and the speed regulation period. The main sources of torque ripple are the imbalance current during commutation and the PWM during speed regulation. A single-inductor multiple-output (SIMO) Buck DC-DC converter is adopted to generate input voltage for the inverter driver of a BLDCM. During the commutation period, the input voltage of an inverter can be adjusted to four times the back electromotive force (EMF), which suppresses the torque ripple caused by imbalance commutation current. Meanwhile, by changing the output voltage of a SIMO DC-DC, the speed of a BLDCM can be regulated without PWM on the inverter switches, which also suppresses the torque ripple. A control algorithm is applied on a Field Programmable Gate Array (FPGA), and the proposed BLDCM drive prototype is fabricated and tested. Measurement results show that with the proposed speed regulation strategy, the torque ripple is suppressed from 33.3% to 20.1%, and that with the proposed suppression strategy in commutation, the torque ripple is suppressed further to 5.3%.