Integrated Protection Unit Design for Power Networks

Zhan-feng Fan,Sheng-ming Ge,Z Q Bo,Lin Wang,Feng-quan Zhou,Xing Liu,Guo-bing Song 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.4

This paper presents an hardware design solution for integrated protection of distribution systems (Network Protection Unit) by combining transient polarity comparison technique, which is based on the detection and processing of fault generated transient current signals. The integrated protection relays installed at each substation of a distribution network are communicated with the Network Protection Unit through specially designed Packet Transport Network (PTN) for fast and reliable transmission of transient polarity current signals. The relay detects the faulted generated super-imposed current signals. The transient polarity identification algorithm is then applied to the super-imposed signals to identify the polarity of the signal detected. The Network Protection Unit can collect all the transient polarity current signals under its protection area. Then The direction of a fault is determined by comparison of the polarity of the signals derived from all the line sections connected to the substation. The actual faulted section is identified by the Network Protection Unit through comparing the directional information from various stations. Simulation results presented in the paper demonstrate the feasibility of the scheme.

Performance of Hepatitis B Core-Related Antigen Versus Hepatitis B Surface Antigen and Hepatitis B Virus DNA in Predicting HBeAg-positive and HBeAg-negative Chronic Hepatitis

Zhan-qing Zhang,Yan-bing Wang,,Wei Lu,,Dan-ping Liu,,Bi-sheng Shi,,Xiao-nan Zhang,,Dan Huang,,Xiu-fen Li,,Xin-lan Zhou,,Rong-rong Ding, 대한진단검사의학회 2019 Annals of Laboratory Medicine Vol.39 No.1

Background: We examined changes in hepatitis B core-related antigen (HBcrAg) during the four sequential phases of chronic hepatitis B virus (HBV) infection: hepatitis B e antigen (HBeAg)-positive chronic infection (EPCI) and hepatitis (EPCH), followed by HBeAg-negative chronic infection (ENCI) and hepatitis (ENCH). We compared the performance of serum HBcrAg, hepatitis B surface antigen (HBsAg), and HBV DNA in predicting EPCH and ENCH.

Performance Analysis of Packet Transport Network Communication for Integrated Wide-Area Protection

Sheng-ming Ge,Z Q Bo,Lin Wang,Zhan-feng Fan,Xing Liu,Feng-quan Zhou 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.3

As a new protection, wide-area protection enables protective relaying, and automatic control based on electric power system network communications and comprehensive judgment of multi-point information, which plays an increasingly important role in the secure and stable operation of electric power system. Interaction of wide-area information relies on communication network featuring high reliability and low time delay. On the other hand, most service of power transformation station is gradually towards IP and data oriented, along with the development of smart grid. This paper aims to introduce the wide-area protection technology supported by Packet Transport Network (PTN) communication technology, with analyzing the QoS (Quality of Service) network assurance architecture of PTN network, which establishes three planes, including transport plane, management plane, and control plane, based on ASON (Automatically Switched Optical Network) technology. After demonstrating the QoS assurance system of PTN from traffic control and transmission route, this paper introduces PTN networking test. Based on detailed parameters in the test results, the transmission performance of PTN on time delay, protection, and time synchronization of various electric power communication services are analyzed, with showing that PTN can fully meet the requirements of electric power communication.

Case Study of the Effect of Rainfall Infiltration on a Tunnel Underlying the Roadbed Slope with Weak Inter-Layer

Sheng-yuan Fan,Zhan-ping Song,Yu-wei Zhang,Nai-fei Liu 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.5

It is a common type of tunnel under-cross the roadbed slope with weak inter-layer. Rainfall infiltration will cause soil softening, matric suction and strength reduction, which seriously threaten the safety of slope and tunnel. This paper presents a case where a tunnel underlying the roadbed slope with weak inter-layer in Guiyang 1# line, China. The seepage calculation model in MIDAS GTS/NX software, considering hydraulic permeability coefficient characteristiccurve and soil-water characteristic curve, was used to analyze the stress and deformation of the roadbed slope and tunnel. The results reveal that rainfall infiltration has great influence on the deformation of roadbed slope with weak inter-layer and the force of internal tunnel. Slope displacement increases rapidly in the early stage and decreases in the late stage, but the absolute value of displacement increases continuously and the slope safety factor decreases gradually, which makes the slope in a dangerous state. The force of tunnel lining increases in the early stage and decreases with the recovery of soil strength after rainfall. The control effects of anchor cable and anti-slide pile reinforcement on slope sliding and tunnel stress were studied. And the anchor cable reinforcement measure is more effective on reducing slope slip and tunnel lining structure internal force.

Let-7c Inhibits NSCLC Cell Proliferation by Targeting HOXA1

Zhan, Min,Qu, Qiang,Wang, Guo,Liu, Ying-Zi,Tan, Sheng-Lan,Lou, Xiao-Ya,Yu, Jing,Zhou, Hong-Hao Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.1

Objective: The aim of the present study was to explore mechanisms by which let-7c suppresses NSCLC cell proliferation. Methods: The expression level of let-7c was quantified by qRT-PCR. A549 and H1299 cells were transfected with let-7c mimics to restore the expression of let-7c. The effects of let-7c were then assessed by cell proliferation, colony formation and cell cycle assay. Mouse experiments were used to confirm the effect of let-7c on tumorigenicity in vivo. Luciferase reporter assays and Western blotting were performed to identify target genes for let-7c. Results: HOXA1 was identified as a novel target of let-7c. MTS, colony formation and flow cytometry assays demonstrated that forced expression of let-7c inhibited NSCLC cell proliferation by inducing G1 arrest in vitro, consistent with inhibitory effects induced by knockdown of HOXA1. Mouse experiments demonstrated that let-7c expression suppressed tumorigenesis. Furthermore, we found that let-7c could regulate the expression of HOXA1 downstream effectors CCND1, CDC25A and CDK2. Conclusions: Collectively, these results demonstrate let-7c inhibits NSCLC cell proliferation and tumorigenesis by partial direct targeting of the HOXA1 pathway, which suggests that restoration of let-7c expression may thus offer a potential therapeutic intervention strategy for NSCLC.

Quasi-nanocrystalline ZrB2 powder synthesized by saltassisted combustion and its formation mechanism

Faqi Zhan,Ru Bai,Xiao Liu,Ke Xu,Hua Zhang,Min Zhu,Yuehong Zheng,Shipeng Xu,Jie Sheng,Peiqing La 한양대학교 청정에너지연구소 2024 Journal of Ceramic Processing Research Vol.25 No.4

Nanoscale ceramic powders are very important for sintering densification and deviceization. A new salt-assisted combustionsynthesis process was used to prepare pure quasi-nanocrystalline zirconium diboride (ZrB2) powder on a large scale. TheZrO2-B2O3-Mg system with single NaCl salt and NaCl-KCl mixed salts as diluents was adopted to prepare ZrB2 powders. The results show that high-purity ZrB2 quasi-nanocrystalline powder with average size of ~105 nm and purity of 99.24% wasobtained by adding molten salts diluent. The impurity mainly existed in the form of Mg0.2Zr0.8O1.8 phase and Mg3B2O6 phase. The effects of diluent content and type on the adiabatic temperature, powder purity, particle size and microstructure of thesystem were studied. This work will provide theoretical basis and technical support for large-scale preparation of boride nanoceramicpowders.

Traditional medicine for post-viral olfactory dysfunction: A systematic review

Zou, Xiang-yun,Liu, Xue-han,Lu, Chun-li,Jin, Xin-yan,He, Bai-xiang,Liao, Yi-lei,Liu, Ting,Dai, Yi-dan,Qi, Shi-hao,Sheng, Zhu-jun,Yan, Zhan-feng,Yang, Guo-Yan,Stub, Trine,Liu Jian-Ping 한국한의학연구원 2024 Integrative Medicine Research Vol.13 No.2

Background: Post-viral olfactory dysfunction (PVOD) is the common symptoms of long COVID, lacking of effective treatments. Traditional Chinese medicine (TCM) is claimed to be effective in treating olfactory dysfunction, but the evidence has not yet been critically appraised. We conducted a systematic review to evaluate the effectiveness and safety of TCM for PVOD. Methods: We searched eight databases to identified clinical controlled studies about TCM for PVOD. The Cochrane risk of bias tools and GRADE were used to evaluate the quality of evidence. Risk ratio (RR), mean differences (MD), and 95 % confidence interval (CI), were used for effect estimation and RevMan 5.4.1 was used for data analysis. Results: Six randomized controlled trials (RCTs) (545 participants), two non-randomized controlled trials (non-RCTs) (112 participants), and one retrospective cohort study (30 participants) were included. The overall quality of included studies was low. Acupuncture (n = 8) and acupoint injection (n = 3) were the mainly used TCM therapies. Five RCTs showed a better effect in TCM group. Four trials used acupuncture, and three trials used acupoint injection. The results of two non-RCTs and one cohort study were not statistically significant. Two trials reported mild to moderate adverse events (pain and brief syncope caused by acupuncture or acupoint injection). Conclusions: Limited evidence focus on acupuncture and acupoint injection for PVOD and suggests that acupuncture and acupoint injection may be effective in improving PVOD. More well-designed trials should focus on acupuncture to confirm the benefit. Protocol registration: The protocol of this review was registered at PROSPERO: CRD42022366776.

In-plane Vibration Analysis of Rotating Cantilever Curved Beams

Guang Hui Zhang,Zhan Sheng Liu,Hong Hee Yoo 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5

Equations of motion of rotating cantilever curved beams are derived based on a dynamic modeling method developed in this paper. The Kane’s method is employed to derive the equations of motion. Different from the classical linear modeling method which employs two cylindrical deformation variables, the present modeling method employs a non-cylindrical variable along with a cylindrical variable to describe the elastic deformation. The derived equations (governing the stretching and the bending motions) are coupled but linear. So they can be directly used for the vibration analysis. The coupling effect between the stretching and the bending motions which could not be considered in the conventional modeling method is considered in this modeling method. The natural frequencies of the rotating curved beams versus the rotating speed are calculated for various radii of curvature and hub radius ratios.

In-plane vibration analysis of cantilevered circular arc beams undergoing rotational motion

Guang Hui Zhang,Zhan Sheng Liu,Hong Hee Yoo 대한기계학회 2008 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.22 No.1

Equations of motion of cantilevered circular arc beams undergoing rotational motion are derived based on a dynamic modeling method developed in this paper. Kane’s method is employed to derive the equations of motion. Different from the classical linear modeling method which employs two cylindrical deformation variables, the present modeling method employs a non-cylindrical variable along with a cylindrical variable to describe the elastic deformation. The derived equations (governing the stretching and the bending motions) are coupled but linear, so they can be directly used for vibration analysis. The coupling effect between the stretching and the bending motions, which could not be considered in the conventional modeling method, is considered in this modeling method. The effects of rotational speed, arc angle, and hub radius ratio on the natural frequencies of the rotating circular arc beam are investigated through numerical analysis.

miR-340 Reverses Cisplatin Resistance of Hepatocellular Carcinoma Cell Lines by Targeting Nrf2-dependent Antioxidant Pathway

Shi, Liang,Chen, Zhan-Guo,Wu, Li-li,Zheng, Jian-Jian,Yang, Jian-Rong,Chen, Xiao-Fei,Chen, Zeng-Qiang,Liu, Cun-Li,Chi, Sheng-Ying,Zheng, Jia-Ying,Huang, Hai-Xia,Lin, Xiang-Yang,Zheng, Fang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.23

Many chemotherapeutic agents have been successfully used to treat hepatocellular carcinoma (HCC); however, the development of chemoresistance in liver cancer cells usually results in a relapse and worsening of prognosis. It has been demonstrated that DNA methylation and histone modification play crucial roles in chemotherapy resistance. Currently, extensive research has shown that there is another potential mechanism of gene expression control, which is mediated through the function of short noncoding RNAs, especially for microRNAs (miRNAs), but little is known about their roles in cancer cell drug resistance. In present study, by taking advantage of miRNA effects on the resistance of human hepatocellular carcinoma cells line to cisplatin, it has been demonstrated that miR-340 were significantly downregulated whereas Nrf2 was upregulated in HepG2/CDDP (cisplatin) cells, compared with parental HepG2 cells. Bioinformatics analysis and luciferase assays of Nrf2-3'-untranslated region-based reporter constructor indicated that Nrf2 was the direct target gene of miR-340, miR-340 mimics suppressing Nrf2-dependent antioxidant pathway and enhancing the sensitivity of HepG2/CDDP cells to cisplatin. Interestingly, transfection with miR-340 mimics combined with miR-340 inhibitors reactivated the Nrf2 related pathway and restored the resistance of HepG2/CDDP cells to CDDP. Collectively, the results first suggested that lower expression of miR-340 is involved in the development of CDDP resistance in hepatocellular carcinoma cell line, at least partly due to regulating Nrf2-dependent antioxidant pathway.