Torsional Vibration Analysis of Hydro-Generator Set Considered Electromagnetic and Hydraulic Vibration Resources Coupling

Zhiqiang Song,Yunhe Liu,Pengcheng Guo,Jianjun Feng 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.7

The torsional vibration characteristics of the hydro-generator set considering the electromagnetic and hydraulic vibration resources coupling are studied. The moment of rotation consists of water flow driving and magnetic torques caused by the air gap magnetic field in the generator rotor in the case of ignoring the mechanical friction. A coupling torque vibration model of hydro-generator shaft system was established. The model considered the coupling action of hydraulic and electromagnetic excitations, as well as the elastic effect of rotor spiders. The influences of the rotor moment inertia, rotor stiffness, and mass of turbine water added into the torsional natural vibration of the unit shaft system were studied. The effect of hydraulic excitation frequency on torsional vibration response was also investigated. The frequency response curves of shaft torque, torsional vibration angle, and electromagnetic torque were presented. The electromagnetic and hydraulic coupling resonance was studied when hydraulic excitation frequency was equal to zero and first-order frequencies. The excitation electric current and internal active power angle on torsional vibration was further analyzed. This study provides an analysis model and method considering the coupling of electromagnetic and hydraulic vibration resources for design and stable operation of water turbine generator sets.

Multiple frequency vibration of the micro lubricating gap geometry between cylinder block and valve plate in an axial piston pump

Zhiqiang Zhang,Yuanyuan Chen,Jianli Song,Kunshan Jin,Haibo Zhou 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.11

Refined models of the forces in the cylinder block/valve plate system along Z axis and the moments around X and Y axes were built, considering the pressure ripple due to the piston reciprocating motions (PRM) and pressure variations in the wedge film (PVF) and the chambers (PVC) caused by the silencing slots. The multi-frequency vibration models of the gap geometry owing to the forces and moments are proposed. The dynamic mechanical balance equations are presented. The frequency spectra of the test gap thickness show the vibration amplitudes at the first three frequencies are larger than those of the other frequencies. PVF and PVC have obvious influences on the gap at the second frequency, and PRM exerts an impact at the third. The moment fluctuations around X and Y axes, bending stiffness of the shaft, and the rough surfaces contact could affect the vibration amplitude of the wedge gap geometry.

Two-level multiblock statistical monitoring for plant-wide processes

Zhiqiang Ge,Zhihuan Song 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.6

Due to the complexity of plant-wide processes, many of the current multivariate statistical process monitoring techniques are lacking in interpretation of the detected fault, and fault identification also becomes difficult. A new two-level multiblock independent component analysis and principal component analysis (MBICA-PCA) method is proposed in this paper. Different from the conventional method, the new approach can incorporate block information into the high level for global process monitoring. Through the new method, the process monitoring task can be greatly reduced and the interpretation for the process can be made more quickly. When a fault is detected, a two-step fault identification method is proposed. The responsible sub-block is first identified by contribution plots, which is followed by fault reconstruction in the corresponding sub-block for advanced fault identification. A case study of the Tennessee Eastman (TE) process evaluates the feasibility and efficiency of the proposed method.

Antioxidative Activity and Irritation Test of a Complex Herbal Bath Extracted from Korean Traditional Plants

Zhiqiang Chang,Young-Hoan Kim,Jae-Chan Song,Nam-Woo Kim,In-Seon Lee,Sam-Pin Lee,Jong-Choon Kim,Seung-Chun Park 한국독성학회 2005 Toxicological Research Vol.21 No.1

The purpose of this study is to evaluate the free radical scavenging ability and xanthine oxidase inhibitory activity of a complex herbal bath consisted of Artemisiae argyi folium, Angelicae sinensis radix, Ligustici wallichii radix and Angelicae tuhuo radix, and its potential irritation response were also tested for safety use in the rabbits. For antioxidative activity, the 1,1-diphenyl-2- picrylhydrazyl (DPPH) radical scavenging activity of the complex herbal bath were examined at five different concentrations (0, 250, 500, 1000 and 2000 μg/ml). The concentration of the complex herbal bath required for scavenging DPPH free radical by 50% was 897.2 ㎍/ml. In the inhibition of xanthine oxidase (XO) activity, the concentration of the complex herbal bath required for 50% of inhibition was 221.4 ㎍/ml. In the skin irritation study in rabbit, all animals survived for the duration of the study and the examined skin exhibited no edema, erythema, and eschar formation. In the ocular irritation study in rabbit, after application of the sample to eyes, all of the eyes were normal. In summary, the complex herbal bath has potent antioxidant effects against the DPPH radical and XO and was considered to be a non-irritation bath for safety use.

Effect of Antrodia camphorata polysaccharides on letrozole-induced polycystic ovary syndrome (PCOS) model rats

Zhiqiang Liu,Chaojie Chong,Zhewen Dong,Yaqi Wu,Wanying Li,Haokun Chen,Shumei Zhong,Junyang Liu,Qi Qi Pang,Jia-Le Song,Yanyuan Zhou 한국식품영양과학회 2021 한국식품영양과학회 학술대회발표집 Vol.2021 No.10

To investigate the effect of ACP on letrozole-induced PCOS rats. All rats were divided into normal groups, PCOS group, metformin group and ACP group. The body weight (BW) was recorded every three days, and the final body weight as well as ovarian weight were recorded. Serum levels of TC, TG, HDL-C, LDL-C and E2, T, FSH and LH were measured by ELISA assay, and the LH/FSH ratio was calculated. The results showed that ACP decreased the BW and the ratio of ovarian to BW. Compared with the normal group, the serum levels of T, LH, LH/FSH, TG, TC, LDL-C increased, and the levels of FSH, E2, HDL-C decreased in PCOS group. ACP effectively improves the serum levels of FSH, LH/FSH, TG, TC, LDL-C and other related factors. The results of H&E staining of ovarian tissues showed that the ACP group showed different degrees of improvement in the reduced number of corpus luteum, thinning of granulosa cell layer, follicular capsular dilatation and follicular atresia. ACP not only reduces BW and the ratio of ovarian to BW, but also it can elevate the level of FSH and reduce LH/FSH, TG, TC and HDL-C levels. Furthermore, ACP can protect ovarian tissue to some extent.

[P8-265] Antioxidant and Anticancer Activities of Methanolic Extract of Trollius chinensis Bunge

Jiale Song,Zhiqiang Liu,Zhijun Wang,Weiming Fang,Zhenquan Yang,Kun-Young Park 한국식품영양과학회 2010 한국식품영양과학회 학술대회발표집 Vol.2010 No.10

Antioxidative Activity and Irritation Test of a Complex Herbal Bath Extracted from Korean Traditional Plants

Chang Zhiqiang,Kim Young-Hoan,Song Jae-Chan,Kim Nam-Woo,Lee In-Seon,Lee Sam-Pin,Kim Jong-Choon,Park Seung-Chun Korean Society of ToxicologyKorea Environmental Mu 2005 Toxicological Research Vol.21 No.1

The purpose of this study is to evaluate the free radical scavenging ability and xanthine oxidase inhibitory activity of a complex herbal bath consisted of Artemisiae argyi folium, Angelicae sinensis radix, Ligustici wallichii radix and Angelicae tuhuo radix, and its potential irritation response were also tested for safety use in the rabbits. For antioxidative activity, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of the complex herbal bath were examined at five different concentrations (0, 250, 500, 1000 and 2000 ㎍/ml). The concentration of the complex herbal bath required for scavenging DPPH free radical by 50% was 897.2 ㎍/ml. In the inhibition of xanthine oxidase (XO) activity, the concentration of the complex herbal bath required for 50% of inhibition was 221.4 ㎍/ml. In the skin irritation study in rabbit, all animals survived for the duration of the study and the examined skin exhibited no edema, erythema, and eschar formation. In the ocular irritation study in rabbit, after application of the sample to eyes, all of the eyes were normal. In summary, the complex herbal bath has potent antioxidant effects against the DPPH radical and XO and was considered to be a non-irritation bath for safety use.

Effect of Homogenization Temperature on Microstructure and Mechanical Properties of Low-Carbon High-Boron Cast Steel

Fu Hanguang,Song Xuding,Lei Yongping,Jiang Zhiqiang,Xing Jiandong,Yang Jun,Wang Jinhua 대한금속·재료학회 2009 METALS AND MATERIALS International Vol.15 No.3

The effects of quenching treatment on the microstructure, hardness, impact toughness, and wear resistance of low-carbon high-boron cast steel (LCHBS) containing 0.15-0.3 %C, 1.4-1.8 %B, 0.3-0.8 %Si, 0.8-1.2 %Mn, 0.5-0.8%Cr, 0.3-0.6%Ni, and 0.3-0.6%Mo have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), and via an electron probe microanalyzer (EPMA), X-ray diffraction (XRD) analysis, impact tester, hardness tester, and wear tester. The as-cast matrix of LCHBS consists of pearlite and ferrite. There is 8-10 vol.% Fe2(B, C) type borocarbides in the matrix. The micro-hardness of Fe2(B, C) is 1430-1480 Hv. Fe2(B,C) shows no obvious change and the matrix completely transforms into lath martensite upon quenching at 900 °C to 1100 °C. The microhardness of the matrix and the macrohardness of the LCHBS sample show a slight increase with an increase of homogenization temperature. When the homogenization temperature exceeds 1050 °C, no distinct change in the hardness is observed. The change of homogenization temperature has no apparent effect on the impact toughness of LCHBS. The mass losses of LCHBS increase distinctly when the wear load increases. The homogenization temperature is less than 1000 °C and the wear rate of LCHBS decreases with an increase of temperature. The wear rate does not display any obvious change after exceeding a homogenization temperature of 1000 °C. The effects of quenching treatment on the microstructure, hardness, impact toughness, and wear resistance of low-carbon high-boron cast steel (LCHBS) containing 0.15-0.3 %C, 1.4-1.8 %B, 0.3-0.8 %Si, 0.8-1.2 %Mn, 0.5-0.8%Cr, 0.3-0.6%Ni, and 0.3-0.6%Mo have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), and via an electron probe microanalyzer (EPMA), X-ray diffraction (XRD) analysis, impact tester, hardness tester, and wear tester. The as-cast matrix of LCHBS consists of pearlite and ferrite. There is 8-10 vol.% Fe2(B, C) type borocarbides in the matrix. The micro-hardness of Fe2(B, C) is 1430-1480 Hv. Fe2(B,C) shows no obvious change and the matrix completely transforms into lath martensite upon quenching at 900 °C to 1100 °C. The microhardness of the matrix and the macrohardness of the LCHBS sample show a slight increase with an increase of homogenization temperature. When the homogenization temperature exceeds 1050 °C, no distinct change in the hardness is observed. The change of homogenization temperature has no apparent effect on the impact toughness of LCHBS. The mass losses of LCHBS increase distinctly when the wear load increases. The homogenization temperature is less than 1000 °C and the wear rate of LCHBS decreases with an increase of temperature. The wear rate does not display any obvious change after exceeding a homogenization temperature of 1000 °C.

Application of advanced spectral-ratio radon background correction in the UAV-borne gamma-ray spectrometry

Xia Jigen,Song Baolin,Gu Yi,Li Zhiqiang,Xu Jie,Ge Liangquan,Zhang Qingxian,Zeng Guoqiang,Liu Qiushi,Yang Xiaofeng 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.8

The influence of the atmospheric radon background on the airborne gamma spectrum can seriously affect researchers’ judgement of ground radiation information. However, due to load and endurance, unmanned aerial vehicle (UAV)-borne gamma-ray spectrometry is difficulty installing upward-looking detectors to monitor atmospheric radon background. In this paper, an advanced spectral-ratio method was used to correct the atmospheric radon background for a UAV-borne gamma-ray spectrometry in Inner Mongolia, China. By correcting atmospheric radon background, the ratio of the average count rate of U window in the anomalous radon zone (S5) to that in other survey zone decreased from 1.91 to 1.03, and the average uranium content in S5 decreased from 4.65 mg/kg to 3.37 mg/kg. The results show that the advanced spectral-ratio method efficiently eliminated the influence of the atmospheric radon background on the UAV-borne gamma-ray spectrometry to accurately obtain ground radiation information in uranium exploration. It can also be used for uranium tailings monitoring, and environmental radiation background surveys

MiR-186 Inhibited Migration of NSCLC via Targeting cdc42 and Effecting EMT Process

Ying Dong,Xintian Jin,Zhiqiang Sun,Yueming Zhao,Xianjing Song 한국분자세포생물학회 2017 Molecules and cells Vol.40 No.3

In this study, qRT-PCR was employed to identify that miR-186 expression level in NSCLC tissues are highly associated with lymph node metastasis. In addition, through the application of western blotting, luciferase assay and qRT-PCR, it was found that miR-186 targeted 3UTR of cdc42 mRNA and down-regulated cdc42 protein level in a post-transcriptional manner. Transwell assay indicated that cdc42 partially reversed the effect of miR-186 mimics. Besides, miR-186 was proved to regulate EMT by influencing biomarkers of this process and cell adhesion ability. Thus, miR-186 is a potential target for NSCLC therapy. miR-186 is proposed to be one of tumor-suppressors and may serve as a therapeutic target in NSCLC treatment.