Effects of Ubiquitin-conjugating Enzyme 2C on Invasion, Proliferation and Cell Cycling of Lung Cancer Cells

Tang, Xiao-Kui,Wang, Ke-Jian,Tang, Yu-Kui,Chen, Li Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.7

The aims of this study were to investigate the influence of ubiquitin- conjugating enzyme E2C (UBE2C) on biological behavior of lung cancer cells. Using MTT, flow cytometry and invasion assays, we detected UBE2C expression and evaluated its biological properties in these cells, including effects on proliferation, the cell cycle profile and invasive capability. Compared with control cells, the UBE2C transfected cells demonstrated increased cellular proliferation (p<0.05). UBE2C transfected cells also had a lower percentage in G1 phase and a higher percentage in S phase (p<0.05). Importantly, the UBE2C transfected cells had a notable enhancement of cell numbers penetrating the basement membrane compared with the control group (p<0.05). Ectopic up-regulation UBE2C promoted the growth of lung cancer cells in vivo. Furthermore, we found UBE2C increased the expression of cyclin D1 and MMP-2. These results show UBE2C may represent a potential therapeutic target for lung cancer.

Equivalent static wind loads analysis of tall television towers considering terrain factors of hilltops based on force measurement experiment

Shi-Tang Ke,Hao Wang,Yao-Jun Ge,Lin Zhao,Shuyang Cao 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.63 No.4

Wind field in mountainous regions demonstrates unique distribution characteristic as compared with the wind field of the flat area, wind load and wind effect are the key considerations in structural design of television towers situated in mountainous regions. The television tower to be constructed is located at the top of Xiushan Mountain in Nanjing, China. In order to investigate the impact of terrain factors of hilltops on wind loads, firstly a wind tunnel test was performed for the mountainous area within 800m from the television tower. Then the tower basal forces such as bending moments and shear strength were obtained based on high frequency force balance (HFFB) test. Based on the experiments, the improved method for determining the load combinations was applied to extract the response distribution patterns of foundation internal force and peak acceleration of the tower top, then the equivalent static wind loads were computed under different wind angles, load conditions and equivalent goals. The impact of terrain factors, damping ratio and equivalent goals on the wind load distribution of a television tower was discussed. Finally the equivalent static wind loads of the television tower under the 5 most adverse wind angles and 5 most adverse load conditions were computed. The experimental method, computations and research findings provide important references for the anti-wind design of high-rise structure built on hilltops.

A study on the working mechanism of internal pressure of super-large cooling towers based on two-way coupling between wind and rain

Shi-Tang Ke,Wenlin Yu,Yao-Jun Ge 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.70 No.4

In the current code design, the use of a uniform internal pressure coefficient of cooling towers as internal suction cannot reflect the 3D characteristics of flow field inside the tower body with different ventilation rate of shutters. Moreover, extreme weather such as heavy rain also has a direct impact on aerodynamic force on the internal surface and changes the turbulence effect of pulsating wind. In this study, the world\'s tallest cooling tower under construction, which stands 210m, is taken as the research object. The algorithm for two-way coupling between wind and rain is adopted. Simulation of wind field and raindrops is performed iteratively using continuous phase and discrete phase models, respectively, under the general principles of computational fluid dynamics (CFD). Firstly, the rule of influence of 9 combinations of wind speed and rainfall intensity on the volume of wind-driven rain, additional action force of raindrops and equivalent internal pressure coefficient of the tower body is analyzed. The combination of wind velocity and rainfall intensity that is most unfavorable to the cooling tower in terms of distribution of internal pressure coefficient is identified. On this basis, the wind/rain loads, distribution of aerodynamic force and working mechanism of internal pressures of the cooling tower under the most unfavorable working condition are compared between the four ventilation rates of shutters (0%, 15%, 30% and 100%). The results show that the amount of raindrops captured by the internal surface of the tower decreases as the wind velocity increases, and increases along with the rainfall intensity and ventilation rate of the shutters. The maximum value of rain-induced pressure coefficient is 0.013. The research findings lay the basis for determining the precise values of internal surface loads of cooling tower under extreme weather conditions.

Wind-sand coupling movement induced by strong typhoon and its influences on aerodynamic force distribution of the wind turbine

Shi-Tang Ke,Yifan Dong,Rongkuan Zhu,Tongguang Wang 한국풍공학회 2020 Wind and Structures, An International Journal (WAS Vol.30 No.4

The strong turbulence characteristic of typhoon not only will significantly change flow field characteristics surrounding the large-scale wind turbine and aerodynamic force distribution on surface, but also may cause morphological evolution of coast dune and thereby form sand storms. A 5MW horizontal-axis wind turbine in a wind power plant of southeastern coastal areas in China was chosen to investigate the distribution law of additional loads caused by wind-sand coupling movement of coast dune at landing of strong typhoons. Firstly, a mesoscale Weather Research and Forecasting (WRF) mode was introduced in for high spatial resolution simulation of typhoon “Megi”. Wind speed profile on the boundary layer of typhoon was gained through fitting based on nonlinear least squares and then it was integrated into the user-defined function (UDF) as an entry condition of small-scaled CFD numerical simulation. On this basis, a synchronous iterative modeling of wind field and sand particle combination was carried out by using a continuous phase and discrete phase. Influencing laws of typhoon and normal wind on moving characteristics of sand particles, equivalent pressure distribution mode of structural surface and characteristics of lift resistance coefficient were compared. Results demonstrated that: Compared with normal wind, mesoscale typhoon intensifies the 3D aerodynamic distribution mode on structural surface of wind turbine significantly. Different from wind loads, sand loads mainly impact on 30° ranges at two sides of the lower windward region on the tower. The ratio between sand loads and wind load reaches 3.937% and the maximum sand pressure coefficient is 0.09. The coupling impact effect of strong typhoon and large sand particles is more significant, in which the resistance coefficient of tower is increased by 9.80% to the maximum extent. The maximum resistance coefficient in typhoon field is 13.79% higher than that in the normal wind field.

United Electromagnetic Characteristics and Online Monitoring Method of Static Air-gap Eccentricity of Turbo-Generator

Tang, Gui-Ji,Ke, Meng-Qiang,He, Yu-Ling,Wang, Fa-Lin The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.6

The purpose of this paper is to investigate the united Electromagnetic characteristics for the effective monitoring on the static air-gap eccentricity (SAGE) of turbo-generator. Different from other studies, this paper not only studies on the unbalanced magnetic pull (UMP) and the vibration characteristics of the stator and the rotor, but also investigates the harmonic features of the magnetic flux density and the circulating current inside the parallel branches (CCPB). The theoretical calculation, together with the finite-element-method (FEM) simulation and the experiment verification, is taken for a SDF-9 type non-salient generator. It is shown that, when SAGE occurs, apparent double-frequency UMP and vibrations will be produced both on the stator and the rotor, while the CCPB will have an obvious increment at the $1^{st}$ harmonic component. In addition, the amplitude of the magnetic flux density will be of cosine distribution in the circumferential position of the air-gap, while in normal condition it is a constant. Moreover, the pass-band amplitude, together with the $1^{st}$ harmonic of the magnetic flux density, will be enlarged as well. These united electromagnetic characteristics can be used as the diagnosis and monitoring criterion for SAGE.

Effects of Turbulent Dispersion on Water Droplet Impingement Based on Statistics Method

Ke Peng,Tang Xing,Lu Yi,Yang Hui Yun 한국항공우주학회 2018 International Journal of Aeronautical and Space Sc Vol.19 No.2

Researchonthewaterdropletmotionandimpactonsurfaceisthebasisofaircrafticingpredictionanddesignoficeprotection system. First, a new computational method based on statistical theory was developed in the Euler–Lagrange framework to calculatethelocalwaterimpingementcoefficientonthesurface,whichcouldbeusedtostudytheeffectofturbulentdispersion onthewaterdropletmotionandimpingementcharacteristics.Second,basedontheRANSmodelfortheairflowfield,taking engineconesurfacewithorwithoutslotasexamples,theinfluenceofturbulentdispersiononthewaterimpingementcoefficient on the surface was comparatively analyzed with the discrete random walk model. For the cone without film slot, turbulence causes a little impact on water droplet impingement. However, for the slotted cone, water droplet collection calculation must consider the effect of turbulence due to the stronger turbulence induced by the jet air. Further studies show that the effect is enhanced with the decrease of water droplet diameter. Finally, discussion about turbulent effects was proposed. This researchabout theinfluence ofturbulentdispersionwillbehelpfultoimprovetheaccuracy ofthewaterdropletimpingement calculation for some complex geometries.

Optimal Sizing and Energy Management of Hybrid Energy Storage System for High-Speed Railway Traction Substation

Tang Sida,Huang Xiaohong,Li Qunzhan,Yang Naiqi,Liao Qinyu,Sun Ke 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.3

Traction power fl uctuations have economic and environmental eff ects on high-speed railway system (HSRS). The combination of energy storage system (ESS) and HSRS shows a promising potential for utilization of regenerative braking energy and peak shaving and valley fi lling. This paper studies a hybrid energy storage system (HESS) for traction substation (TS) which integrates super-capacitor (SC) and vanadium redox battery (VRB). According to the characteristics of the traction load under actual operating conditions, an energy management strategy with fi xed-period control (FPC) is proposed, which fully leverages the periodicity and regularity of HSRS operation. To achieve the optimal size, economic feasibility is selected as the optimization objective, which is fully assessed in terms of Net Present Value (NPV). The optimization constraints are formulated in which the Discrete Fourier Transform (DFT) is performed for power allocation between SC and VRB. Besides, an improved mutation-based particle swarm optimization (IMBPSO) is proposed to effi ciently solve the optimization and enhance convergence performance. Finally, combined with the measured traction load data, the eff ectiveness of the FPC energy management strategy is verifi ed and the optimal scale of the HESS is provided.

Room-temperature tensile strength and thermal shock behavior of spark plasma sintered W-K-TiC alloys

Ke Shi,Bo Huang,Bo He,Ye Xiao,Xiaoliang Yang,Youyun Lian,Xiang Liu,Jun Tang 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.1

W-K-TiC alloys with different titanium carbide concentrations (0.05, 0.1, 0.25, 0.5, 1, 2) wt.% werefabricated through Mechanical Alloying and Spark Plasma Sintering. The effects of the addition of nanoscaledTiC particles on the relative density, Vickers micro-hardness, microstructure, crystal information,thermal shock resistance, and tensile strength were investigated. It is revealed that the doped TiC nanoparticleslocated at the grain boundaries. The relative density and Vickers micro-hardness of W-K-TiCalloys was enhanced with TiC addition and the highest Vickers micro-hardness is 731.55. As the TiCaddition increased from 0.05 to 2 wt%, the room-temperature tensile strength raised from 141 to353 MPa. The grain size of the W-K-TiC alloys decreased sharply from 2.56 mm to 330 nm with theenhanced TiC doping. The resistance to thermal shock damage of W-K-TiC alloys was improved slightlywith the increased TiC addition

IGBT Open-Circuit Fault Diagnosis for 3-Phase 4-Wire 3-Level Active Power Filters based on Voltage Error Correlation

Ke Wang,Yi Tang,Xiao Zhang,Yang Wang,Chuan-Jin Zhang,Hui Zhang 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.5

A novel open-circuit fault diagnosis method for 3-phase 4-wire 3-level active power filters based on voltage error correlation is proposed in this paper. This method is based on observing the output pole voltage error of the active power filter through two kinds of algorithms. One algorithm is a voltage error analytical algorithm, which derives four output voltage error analytic expressions through the pulse state, current value and dc bus voltage, respectively, assuming that all of the IGBTs of a certain phase come to an OC fault. The other algorithm is a current circuit equation algorithm, which calculates the real-time output voltage error through basic circuit theory. A correlation is introduced to measure the similarity of the output voltage errors between the two algorithms, and OC faults are located by the maximum of the correlations. A FPGA has been chosen to implement the proposed method due to its fast prototyping. Simulation and experimental results are presented to show the performance of the proposed OC fault diagnosis method.

Zero-Current Phenomena Analysis of the Single IGBT Open Circuit Faults in Two-Level and Three-Level SVGs

Ke Wang,Hong-Lu Zhao,Yi Tang,Xiao Zhang,Chuan-Jin Zhang 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.2

The fact that the reliability of IGBTs has become a more and more significant aspect of power converters has resulted in an increase in the research on the open circuit (OC) fault location of IGBTs. When an OC fault occurs, a zero-current phenomena exists and frequently appears, which can be found in a lot of the existing literature. In fact, fault variables have a very high correlation with the zero-current interval. In some cases, zero-current interval actually decides the most significant fault feature. However, very few of the previous studies really explain or prove the zero-current phenomena of the fault current. In this paper, the zero-current phenomena is explained and verified through mathematical derivation, based on two-level and three-level NPC static var generators (SVGs). Mathematical models of single OC fault are deduced and it is concluded that a zero-current interval with a certain length follows the OC faults for both two-level and NPC three-level SVGs. Both inductive and capacitive reactive power situations are considered. The unbalanced load situation is discussed. In addition, simulation and experimental results are presented to verify the correctness of the theoretical analysis.