A 3-D Steady-State Analysis of Thermal Behavior in EHV GIS Busbar

Jin Lei,Jian-ying Zhong,Shi-jin Wu,Zhen Wang,Yu-jing Guo,Xin-yan Qin 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.3

Busbar has been used as electric conductor within extra high voltage (EHV) gas insulated switchgear (GIS), which makes EHV GIS higher security, smaller size and lower cost. However, the main fault of GIS is overheating of busbar connection parts, circuit breaker and isolating switch contact parts, which has been already restricting development of GIS to a large extent. In this study, a coupled magneto-flow-thermal analysis is used to investigate the thermal properties of GIS busbar in steady-state. A three-dimensional (3-D) finite element model (FEM) is built to calculate multiphysics fields including electromagnetic field, flow field and thermal field in steady-state. The influences of current on the magnetic flux density, flow velocity and heat distribution has been investigated. Temperature differences of inner wall and outer wall are investigated for busbar tank and conducting rod. Considering the end effect in the busbar, temperature rise difference is compared between end sections and the middle section. In order to obtain better heat dissipation effect, diameters of conductor and tank are optimized based on temperature rise simulation results. Temperature rise tests have been done to validate the 3-D simulation model, which is observed a good correlation with the simulation results. This study provides technical support for optimized structure of the EHV GIS busbar.

A 3-D Steady-State Analysis of Thermal Behavior in EHV GIS Busbar

Lei, Jin,Zhong, Jian-ying,Wu, Shi-jin,Wang, Zhen,Guo, Yu-jing,Qin, Xin-yan The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.3

Busbar has been used as electric conductor within extra high voltage (EHV) gas insulated switchgear (GIS), which makes EHV GIS higher security, smaller size and lower cost. However, the main fault of GIS is overheating of busbar connection parts, circuit breaker and isolating switch contact parts, which has been already restricting development of GIS to a large extent. In this study, a coupled magneto-flow-thermal analysis is used to investigate the thermal properties of GIS busbar in steady-state. A three-dimensional (3-D) finite element model (FEM) is built to calculate multiphysics fields including electromagnetic field, flow field and thermal field in steady-state. The influences of current on the magnetic flux density, flow velocity and heat distribution has been investigated. Temperature differences of inner wall and outer wall are investigated for busbar tank and conducting rod. Considering the end effect in the busbar, temperature rise difference is compared between end sections and the middle section. In order to obtain better heat dissipation effect, diameters of conductor and tank are optimized based on temperature rise simulation results. Temperature rise tests have been done to validate the 3-D simulation model, which is observed a good correlation with the simulation results. This study provides technical support for optimized structure of the EHV GIS busbar.

Understanding the Evolution of Cooperation in Distributed Systems

Lei Jin,Xin Jin 한국산학기술학회 2014 SmartCR Vol.4 No.3

The success of distributed systems such as grids and P2P networks lies in cooperation for local resource sharing. The lack of any centralized coordinator and the selfish behaviors of individual machines, however, raise a problem for such cooperation, leaving the prescribed protocol vulnerable to strategic manipulation. The most significant recent advances in distributed systems have therefore been to apply game theory and other branches in economics to model incentives for cooperation, as the first step towards robust protocol design. In this paper, we aim to provide an analytical framework to investigate the evolution of cooperation in distributed systems.

Albumin-to-Fibrinogen Ratio as an Independent Prognostic Parameter in Untreated Chronic Lymphocytic Leukemia: A Retrospective Study of 191 Cases

Yi-Xin Zou,Jia Qiao,Hua-Yuan Zhu,Rui-Nan Lu,Yi Xia,Lei Cao,Wei Wu,Hui Jin,Wen-Jie Liu,Jin-Hua Liang,Jia-Zhu Wu,Li Wang,Lei Fan,Wei Xu,Jian-Yong Li 대한암학회 2019 Cancer Research and Treatment Vol.51 No.2

Purpose Chronic lymphocytic leukemia (CLL) is one of the most frequent type of B-cell chronic lymphoproliferative disorders and chronic inflammation takes part in the development of CLL. However, there has been no valid immune biomarker to predict the prognosis of untreated CLL patients. Materials and Methods In this retrospective study, we analyzed the clinical correlations and prognostic value of albumin-to-fibrinogen ratio (AFR) detected at diagnosis in 191 CLL patients. Results The cut-off value of AFR was 9.7 calculated by X-tile. Patients who were more than 65 years old were often accompanied by low level of AFR (p < 0.001). Survival analysis showed that patients with low level of AFR had shorter overall survival (OS) than patients with high level of AFR (p < 0.001). Multivariate analysis illustrated that AFR had a negative impact on OS (p=0.003) and was independent of parameters involved in CLL international prognostic index and other prognostic markers such as CD38 and ZAP-70. Conclusion These data provide a comprehensive view of AFR and shows that AFR at diagnosis is an adverse prognostic factor in untreated CLL patients.

Experimental Study on Interfacial Shear Performance of RC Beams Added to Existing RC Columns

Xin-Ling Wang,Lei-Lei Jin,Ke Li,Jun-Tao Zhu 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.11

The primary objectives of this study were to experimentally investigate the shear characteristicsof the interface between an existing RC column and a reinforced concrete (RC) beam added to the existing RC column, and to propose a formula for estimating the shear capacity of the beam-column interface. The major test variables consisted of concrete strength, added steel reinforcement ratio and shear span to depth ratio. Failure characteristics, displacements at the loading point, slips of the beam-column interface, and shear capacities of the beam-column interface were analyzed. Test results indicate that both the shear capacity of the beam-column interface and the corresponding interfacial slip increased with a decrease in shear span to depth ratio. In addition, as concrete strength grew, the shear capacity of the beam-column interface increased, but the interfacial slip corresponding to the interfacial shear capacity remained almost unchanged. Moreover, both the shear capacity of the beam-column interface and the corresponding interfacial slip increased with an increase in the longitudinal steel reinforcement ratio of the added RC beam. A formula for predicting the shear capacity of the beam-column interface was developed. The test results validate the proposed formula and provide important guidance for the design of the RC beam added to the existing RC column.

Effect of antibiotics and synbiotic on growth performance, nutrient digestibility, and faecal microbial shedding in growing-finishing pigs

Lei, Xin Jian,Zhang, Wan Lin,Cheong, Jin Young,Lee, Sang In,Kim, In Ho Informa UK (TaylorFrancis) 2018 Journal of applied animal research Vol.46 No.1

Probing the nature of high‐<i>z</i> short GRB 090426 with its early optical and X‐ray afterglows

Xin, Li‐,Ping,Liang, En‐,Wei,Wei, Jian‐,Yan,Zhang, Bing,Lv, Hou‐,Jun,Zheng, Wei‐,Kang,Urata, Yuji,Im, Myungshin,Wang, Jing,Qiu, Yu‐,Lei,Deng, Jin‐,Song,Huang, Blackwell Publishing Ltd 2011 MONTHLY NOTICES- ROYAL ASTRONOMICAL SOCIETY Vol.410 No.1

<P><B>ABSTRACT</B></P><P>GRB 090426 is a short‐duration burst detected by <I>Swift</I> (<IMG src='/wiley-blackwell_img/equation/MNR_17419_mu1.gif' alt ='inline image'/> s in the observer frame and <IMG src='/wiley-blackwell_img/equation/MNR_17419_mu2.gif' alt ='inline image'/> s in the burst frame at <I>z</I>= 2.609). Its host galaxy properties and some gamma‐ray‐related correlations are analogous to those seen in long‐duration gamma‐ray bursts (GRBs), which are believed to be of a massive star origin (so‐called Type II GRBs). We present the results of its early optical observations with the 0.8‐m Tsinghua University–National Astronomical Observatory of China Telescope (TNT) at Xinglong Observatory and the 1‐m LOAO telescope at Mt Lemmon Optical Astronomy Observatory in Arizona. Our well‐sampled optical afterglow light curve covers from <IMG src='/wiley-blackwell_img/equation/MNR_17419_mu3.gif' alt ='inline image'/> to 10<SUP>4</SUP> s after the GRB trigger. It shows two shallow decay episodes that are likely due to energy injection, which end at <IMG src='/wiley-blackwell_img/equation/MNR_17419_mu4.gif' alt ='inline image'/> and 7100 s, respectively. The decay slopes after the injection phases are consistent with each other (<IMG src='/wiley-blackwell_img/equation/MNR_17419_mu5.gif' alt ='inline image'/>). The X‐ray afterglow light curve appears to trace the optical, although the second energy‐injection phase was missed due to visibility constraints introduced by the <I>Swift</I> orbit. The X‐ray spectral index is <IMG src='/wiley-blackwell_img/equation/MNR_17419_mu6.gif' alt ='inline image'/> without temporal evolution. Its decay slope is consistent with the prediction of the forward shock model. Both X‐ray and optical emission are consistent with being in the same spectral regime above the cooling frequency (<IMG src='/wiley-blackwell_img/equation/MNR_17419_mu7.gif' alt ='inline image'/>). The fact that <IMG src='/wiley-blackwell_img/equation/MNR_17419_mu8.gif' alt ='inline image'/> is below the optical band from the very early epoch of the observation provides a constraint on the burst environment, which is similar to that seen in classical long‐duration GRBs. We therefore suggest that death of a massive star is the possible progenitor of this short burst.</P>

Effect of humidity on mechanical properties of dissolving microneedles for transdermal drug delivery

Qi Lei Wang,Jia Wei Ren,Bo Zhi Chen,Xuan Jin,Can Yang Zhang,Xin Dong Guo 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.59 No.-

Dissolving microneedles (DMNs) prepared from soluble polymers has been being widely investigated as a safe and effective transdermal delivery system for drug and vaccine. Limited by the materials, the air humidity would probably affect the mechanical property of DMNs, which is essential for the effective needle insertions and drug delivery. In this study, four kinds DMNs prepared by polyvinyl alcohol, sodium hyaluronate (HA), chitosan and gelatin are studied on the mechanical strength and insertion ability under varying humidity conditions. Based on these investigations, we hope to provide the effective time of DMNs to ensure a successful insertion and drug delivery.

A Hyper-cross-linked Polynaphthalene Semiconductor with Excellent Visible-Light Photocatalytic Performance in the Degradation of Organic Dyes

Zhang, Lei,Huang, Xin-Hua,Hu, Jin-Song,Song, Jian,Kim, Il American Chemical Society 2017 Langmuir Vol.33 No.8

<P>Hyper-cross-linked polynaphthalene nanoparticles (PNNs) capable of catalyzing the degradation of organic pollutants upon exposure to visible light have been developed. The nascent and metal-free PNNs with a porous structure, high specific surface area, and narrow bandgap are chemically and thermally stable in the catalytic system, which make it promising as a kind of excellent photocatalytic material compared to conventional photocatalysts. The photo catalytic activity of the as-obtained PNNs exhibits remarkable photocatalytic perforniance for the degradation of rhodamine B (RhB) and methyl blue (MB) under the irradiation of visible light. The easy preparation,, high catalytic activity, and recyclability of the PNNs open new opportunities in the visible-light promoted degradation of organic pollutants.</P>

Enhanced photoluminescence from KCl flux assisted Eu3+ doped CaTiO3 red phosphor for temperature sensing

Xiuying Tian,Lei Li,Mengyuan Wei,Changyan Ji,Zhi Huang,Xin Liu,Jin Wen,Yangxi Peng 한양대학교 세라믹연구소 2021 Journal of Ceramic Processing Research Vol.22 No.5

CaTiO3: Eu3+ red phosphors with high thermal stability and temperature sensitivity were synthesized by KCl flux assisted solidphase reaction method and they had orthorhombic perovskite phase. CaTiO3:15%Eu3+ had the irregular particle structure,with mean particle size of about 1.58 μm, while CaTiO3:15%Eu3+ +6%KCl also had the irregular particle structure, with meanparticle size of about 2.25 μm. When Eu3+ ion concentration was 15mol%, concentration quenching phenomenon took place,which could be explained by electric dipole-dipole interaction due to the critical Eu3+- Eu3+ distance of ~ 8.93 Å. We found thatKCl flux could increase the particle size and crystallinity, which was beneficial to luminescence property. Based on the PLspectra excited at 398 nm, the color coordinates of CaTiO3:15%Eu3+ were (0.5911, 0.4008) and the color purity was 97.7%,while the color coordinates of sample CaTiO3:15%Eu3++ 6%KCl were (0.6042, 0.3895) and the color purity was 98.4%. Therelative intensity IR1 and IR2 at 423 K is 87. 29% and 83. 22%, indicating the sample had high thermal stability. Based on TCLsFIR, Sr of CaTiO3:15%Eu3+ is 2322.67/T^2. CaTiO3:Eu3+ red phosphor was expected to be a promising inorganic material forpossible applications in temperature sensing.