Signal processing method based on energy ratio for detecting leakage of SG using EVFM

Xu Wei,Xu Ke-Jun,Yan Xiao-Xue,Yu Xin-Long,Wu Jian-Ping,Xiong Wei 한국원자력학회 2020 Nuclear Engineering and Technology Vol.52 No.8

In the sodium-cooled fast reactor, the steam generator is a heat exchange device between sodium and water, which may cause leakage, resulting in a sodium-water reaction accident, which in turn affects the safe operation of the entire nuclear reactor. To this end, the electromagnetic vortex flowmeter is used to detect leakage of the steam generator and its signal processing method is studied in this paper. The hydraulic experiment was carried out by using water instead of liquid sodium, and the sensor output signal of the electromagnetic vortex flowmeter under different gas injection volumes was collected. The bubble noise signal is reflected by the base line of the sensor output signal. According to the relationship between the proportion of the bubble noise signal in the sensor output signal and the gas injection volume, a signal processing method based on the energy ratio calculation is proposed to detect whether the water contains bubbles. The gas injection experiment of liquid sodium was conducted to verify the effectiveness of the signal processing method in the detection of bubbles in sodium, and the minimum detectable leak rate of water in the steam generator was detected to be 0.2 g/s.

A numerical study on nonlinear stability of higher-order sandwich beams with cellular core and nanocomposite face sheets

Ke Ding,Hu Jia,Jun Xu,Yi Liu,Haneen M. Al-Tamimi,Mohamed Amine Khadimallah 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.83 No.4

In this research, a numerical study has been provided for examining the nonlinear stability behaviors of sandwich beams having a cellular core and two face sheets made of nanocomposites. The nonlinear stability behaviors of the sandwich beam having geometrically perfect/imperfect shapes have been studied when it is subjected to a compressive buckling load. The nanocomposite face sheets are made of epoxy reinforced by graphene oxide powders (GOPs). Also, the core has the shape of a honeycomb with regular configuration. Using finite element method based on a higher-order deformation beam element, the system of equations of motions have been solved to derive the stability curves. Several parameters such as face sheet thickness, core wall thickness, graphene oxide amount and boundary conditions have remarkable influences on stability curves of geometrically perfect/imperfect sandwich beams.

Buckling Analysis of Columns Ended by Rotation-stiffness Spring Hinges

Ke Cao,Yao-Jie Guo,Jun Xu 한국강구조학회 2016 International Journal of Steel Structures Vol.16 No.1

Stabilities of compressed columns ended by spring hinges with particular rotation stiffness was a basic theory for more complex structures’ researches and engineering, however investigations on calculation approaches for these columns were rarely reported. This paper focus on buckling analysis on these spring hinge ended columns, and the derivation of the columns’ effective length factor equation were presented. Meanwhile a practical design formula to predicate the effective length factors was proposed and further validated to be highly accurate. Furthermore impacts of ideal-ends column method, which ignoring real ends’ rotation stiffness, were investigated. Finally conditions making ideal-ends column method accurate enough in practice were put forward and the practical condition equations were proposed.

Signal processing method of bubble detection in sodium flow based on inverse Fourier transform to calculate energy ratio

Xu, Wei,Xu, Ke-Jun,Yu, Xin-Long,Huang, Ya,Wu, Wen-Kai Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.9

Electromagnetic vortex flowmeter is a new type of instrument for detecting leakage of steam generator, and the signal processing method based on the envelope to calculate energy ratio can effectively detect bubbles in sodium flow. The signal processing method is not affected by changes in the amplitude of the sensor output signal, which is caused by changes in magnetic field strength and other factors. However, the detection sensitivity of the electromagnetic vortex flowmeter is reduced. To this end, a signal processing method based on inverse Fourier transform to calculate energy ratio is proposed. According to the difference between the frequency band of the bubble noise signal and the flow signal, only the amplitude in the frequency band of the flow signal is retained in the frequency domain, and then the flow signal is obtained by the inverse Fourier transform method, thereby calculating the energy ratio. Using this method to process the experimental data, the results show that it can detect 0.1 g/s leak rate of water in the steam generator, and its performance is significantly better than that of the signal processing method based on the envelope to calculate energy ratio.

Stability Analysis of Closely Star-battened Member of Transmission Tower

Han Jun-ke,Zhang Chun-lei,Li Zhen-bao,Wang Xu-ming 한국강구조학회 2017 International Journal of Steel Structures Vol.17 No.3

Stability of the closely star-battened member of a power transmission tower were researched in this paper, a theoretical analysis was conducted for the buckling mode of the closely star-battened member by different plate batten arrangements. The analytical method of the buckling capacity on the closely star-battened member was proposed here considering an arrangement type of the plate batten and they are compared with the results of a full-scale test. The conclusions are follows: the flexuraltorsional buckling did not happened for the closely star-battened member; the flexural buckling need to be calculated only after the strength reduction factor was considered; the stability-bearing capacity of the closely star-battened member of the line-shape type batten is slightly less than that of the cross-shape type batten; the stability-bearing capacity of the closely star-battened member can be improved when the number of bolts in the plate batten increases in a suitable extent; and the stability-bearing capacity calculated and test results agree well with each other when the stability-bearing capacity analytical method of the closely star-battened member was used to analyze the full-scale test tower. The experimental results show the calculation method is reasonable.

Human Telomerase Gene and High-Risk Human Papillomavirus Infection are Related to Cervical Intraepithelial Neoplasia

Zhao, Xu-Ye,Cui, Yongm,Jiang, Shu-Fang,Liu, Ke-Jun,Han, Hai-Qiong,Liu, Xiao-Su,Li, Yali Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.2

Our aims were to evaluate the clinical performance of human telomerase RNA gene component (hTERC gene) amplification assay with high-risk human papillomavirus (HR-HPV) DNA test of Hybrid Capture 2 DNA test (HC2), for the detection of high grade cervical precancerous lesions and cancer (CIN 2+). In addition, the association shown between hTERC gene amplification and HPV DNA test positive in women with and without cervical neoplasia was assessed. There were 92 women who underwent cytology, HR-HPV DNA test, hTERC gene amplification test, colposcopy and biopsy. We compared the clinical performance of hTERC gene test along with HR-HPV DNA test of women with colposcopy and routine screening. The samples were histology-confirmed high-grade cervical intraepithelial neoplasia (CIN 2) or worse (CIN2+) as the positive criterion. The test of hTERC gene showed the hTERC gene amplification positivity increased with the severity of histological abnormality and cytological abnormality. The test of hTERC gene showed higher specificity than HR-HPV DNA test for high-grade lesions (84.4% versus 50%) and also higher positive predictive value (90.4% versus 76.5%). Our results predicted that hTERC gene amplification demonstrated more specific performance for predicting the risk of progression and offer a strong potential as a tool for triage in cervical cancer screening, with the limited sensitive as HR-HPV DNA test.

X-Ray Repair Cross-Complementing Group 1(XRCC1) Genetic Polymorphisms and Thyroid Carcinoma Risk: a Meta-Analysis

Qian, Ke,Liu, Kui-Jie,Xu, Feng,Chen, Xian-Yu,Chen, Gan-Nong,Yi, Wen-Jun,Zhou, En-Xiang,Tang, Zhong-Hua Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.12

A number of studies have been conducted to explore the association of XRCC1 polymorphisms with thyroid cancer risk, but the results have been inconsistent. Thus we performed the present meta-analysis to clarify this issue based on all of the evidence available to date. Relevant studies were retrieved by searching PubMed and statistical analysis conducted using Stata software. Nine studies were included in this meta-analysis (1,620 cases and 3,557 controls). There were 6 studies (932 cases and 2,270 controls) of the Arg194Trp polymorphism, 7 studies (1432 cases and 3356 controls) of the Arg280His polymorphism and 9 studies (1,620 cases and 3,557 controls) for the Arg399Gln polymorphism. No association of XRCC1 Arg194Trp, Arg280His and Arg399Gln polymorphism with thyroid cancer risk was observed in the overall analysis. However, subgroup analysis revealed: 1) an elevated risk in aa vs AA analysis (OR=2.03, 95%CI= 1.24-3.31) and recessive genetic model analysis (OR=1.93, 95%CI= 1.20-3.08) in the larger sample size trials for XRCC1 Arg194Trp polymorphism; 2) a decreased thyroid cancer risk on subgroup analysis based on ethnicity in Aa vs AA analysis (OR=0.84, 95%CI= 0.72-0.98) and in a dominant genetic model (OR=0.84, 95%CI= 0.72-0.97) in Caucasian populations for the XRCC1 Arg399Gln polymorphism; 3) a decreased thyroid cancer risk on subgroup analysis based on design type in Aa vs AA analysis (OR=0.72, 95% CI= 0.54-0.97) among the PCC trials for the Arg399Gln polymorphism. Our results suggest that the XRCC1 Arg399Gln polymorphism may be associated with decreased thyroid cancer risk among Caucasians and XRCC1 Arg194Trp may be associated with a tendency for increased thyroid cancer risk in the two larger sample size trials.

Insufficient radiofrequency ablation-induced autophagy contributes to the rapid progression of residual hepatocellular carcinoma through the HIF-1α/BNIP3 signaling pathway

( Wen-lei Xu ),( Shao-hong Wang ),( Wen-bing Sun ),( Jun Gao ),( Xue-mei Ding ),( Jian Kong ),( Li Xu ),( Shan Ke ) 생화학분자생물학회(구 한국생화학분자생물학회) 2019 BMB Reports Vol.52 No.4

Currently speaking, it is noted that radiofrequency ablation (RFA) has been the most widely used treatment for hepatocellular carcinoma (HCC) occurring in patients. However, accumulating evidence has demonstrated that the incidence of insufficient RFA (IRFA) may result in the identified rapid progression of residual HCC in the patient, which can greatly hinder the effectiveness and patient reported benefits of utilizing this technique. Although many efforts have been proposed, the underlying mechanisms triggering the rapid progression of residual HCC after IRFA have not yet been fully clarified through current research literature reviews. It was shown in this study that cell proliferation, migration and invasion of residual HepG2 and SMMC7721 cells were significantly increased after the IRFA was simulated in vitro. In other words, it is noted that IRFA could do this by enhancing the image of autophagy of the residual HCC cell via the HIF-1 α/BNIP3 pathway. Consequently, the down-regulation of BNIP3 may result in the inhibition of the residual HCC cell progression and autophagy after IRFA. Our present study results suggest that IRFA could promote residual HCC cell progression in vitro by enhancing autophagy via the HIF-1 α/BNIP3 pathway. For this reason, it is noted that the targeting of the BNIP3 may be useful in preventing the rapid growth and metastasis of residual HCC after IRFA. [BMB Reports 2019; 52(4): 277-282]

Prescribed Performance-tangent Barrier Lyapunov Function for Adaptive Neural Backstepping Control of Variable Stiffness Actuator with Input and Output Constraints

Yu Xia,Jun-Yang Li,Yan-Kui Song,Jia-Xu Wang,Yan-Feng Han,Ke Xiao 제어·로봇·시스템학회 2023 International Journal of Control, Automation, and Vol.21 No.3

Due to the complexity of modeling and the strong transmission coupling, the rich background of rigid actuator control has not been transferred to variable stiffness actuator (VSA). Therefore, most model-based control techniques developed for VSA require feedback linearization first. Alternatively, VSA can use non-model-based control techniques such as PD control, but it does not show strong robustness under disturbances. This paper is concerned with designing a novel adaptive neural network backstepping control scheme without using feedback linearization for a special VSA with saturation inputs, output constraints, and disturbances. Firstly, for ensuring the VSA with lower tracking error and higher security, the prescribed performance-tangent barrier Lyapunov function (PP-TBLF) is introduced to handle the prescribed output performance constraints. Subsequently, the Chebyshev neural network and the Nussbaum-type function are exploited to approximate the unknown nonlinearities and unknown gains. Meanwhile, the inverse hyperbolic sine function tracking differentiator is utilized to solve the “explosion of complexity” caused by the differentiation of virtual inputs and also approximate the complex partial derivatives caused by the auxiliary control signals. Finally, the stability of the whole scheme is proved by the Lyapunov criterion. The simulation results illustrate the raised control scheme’s feasibility and show a better closed-loop behavior relative to that obtained using a classic PD controller.

Transducer analysis and signal processing of PMSF with embedded bluff body

Yan, Xiao-Xue,Xu, Ke-Jun,Xu, Wei,Yu, Xin-Long,Wu, Jian-Ping Korean Nuclear Society 2020 Nuclear Engineering and Technology Vol.52 No.2

Permanent magnet sodium flowmeter (PMSF) have been used to measure the sodium flow in fast breeder reactors. Due to the effects of irradiation, thermal cycling, time lapse, etc., the magnetic flux density of the PMSF will decrease after being used in the reactor for a period of time. Therefore, it must be calibrated regularly. But some flowmeters that immersed in sodium cannot be removed for an off-line calibration, so the on-line calibration is required. However, the best online calibration accuracy of PMSF using cross-correlation analysis method was 2.0-level without considering the repeatability. In order to further improve this work, the operational principle of the transducer in PMSF is analyzed and the design principle of the transducer is proposed. The transducers were tested on the sodium flow loop to collect the experimental data. The signal characteristics are analyzed from the time and frequency domains, respectively. The cross-correlation analysis method based on biased estimation is adopted to obtain the flow rate. The verification experimental results showed that the measurement accuracy is 1.0-level when the flow velocity is above 0.5 m/s, and the measurement accuracy is 3.0-level when the flow velocity is in the range of 0.2 m/s to 0.5 m/s.