Influence of Diffuser Vane Number on Energy Loss of Multistage Centrifugal Pump

Tian Xin Wu,Deng Hao Wu,Ting Zhang,Hai Ming Huang,Yue Zhong Wu,Jie Gang Mou 한국유체기계학회 2021 International journal of fluid machinery and syste Vol.14 No.4

As a key component of a multistage pump, the diffuser affects the efficiency of the multistage centrifugal pump. However, the loss mechanism inside the diffuser and links between the loss mechanism and vane numbers of diffuser were still not fully understood. In order to investigate the influence of the number of diffuser vane on the energy loss characteristics of multistage centrifugal pump, this paper analyzes the energy loss characteristics of pump with different number of diffuser vane by utilizing entropy production theory. The results show that under the design condition, when the number of diffuser vane increases to 11, the head is increased by 1.2m and the efficiency is increased by 3%. At the same time, with the increase of the number of diffuser vane, the backflow and eddy phenomena are gradually weakened, flow stream is more stable, the entropy production rate is significantly reduced, but the intensity of pressure pulsation in the diffuser is increased slightly.

Fotemustine, Teniposide and Dexamethasone in Treating Patients with CNS Lymphoma

Wu, Jing-Jing,Wang, Xin-Hua,Li, Ling,Li, Xin,Zhang, Lei,Sun, Zhen-Chang,Fu, Xiao-Rui,Ma, Wang,Chang, Yu,Zhang, Xu-Dong,Han, Li-Juan,Zhang, Ming-Zhi Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.11

Purpose: We developed and evaluated a regimen including fotemustine, teniposide and dexamethasone (FTD) for treating patients with central nervous system (CNS) lymphoma based on pharmacokinetic properties of individual agents and in combination. Patients and Methods: In a comparison study, 8 patients with primary CNS lymphoma (PCNSL) and 8 with secondary CNS lymphoma (SCNSL) were treated with FTD (comprising fotemustine 100 mg/m2, 1h infusion, day 1; teniposide 60 mg/m2, >0.5 h infusion, on day 2, 3, 4; dexamethasone 40 mg, 1h infusion, on day 1, 2, 3, 4 and 5; and methotrexate 12 mg, cytosine arabinoside 50 mg plus dexamethasone 5 mg intrathecally, on day 2 and 7). Cycles were repeated every 3 weeks. After response assessment, patients received whole brain radiotherapy. Results: Of the 8 PCNSL patients, 4 (50%) achieved CR and 3 (38%) PR, an overall response rate of 88%. Four patients (50%) were in continuing remission at the end of this study after a median follow-up of 30 months (range 10 to 56 months). Of the 8 SCNSL patients the overall response rate was 63% (CR+PR: 38%+25%). All responses were achievable with predictable toxicity mainly reflecting reversible myelosuppression. Conclusion: This study suggests that FTD could be an effective treatment for CNS lymphoma, and is worthy of further evaluation.

Color stability and degradation kinetics of anthocyanins in mulberry stirred yoghurt fermented by different starter cultures

Xin Cheng,Jinpeng Zhu,Zhijie Chen,Zhihao Wu,Fuqiang Zhang,Cai-e Wu,Gong-Jian Fan 한국식품과학회 2023 Food Science and Biotechnology Vol.32 No.10

To evaluate the storage stability of anthocyanin in stirred yoghurt, mulberry juice and different starter cultures (S) were added into milk to investigate the color stability and degradation kinetics of anthocyanin. The result showed that the redness value decreased, while the brightness value increased, and the anthocyanin content decreased significantly from 1.47 ~ 1.86 to 1.01 ~ 1.19 mg/g. The degradation kinetics followed a first-order reaction. Principal component analysis showed that S2 and S6 were correlated with anthocyanins, S8 and S4 were correlated with a*. At the later stage, S4, S8 were correlated with a*, while S2, S4, S6 were correlated with anthocyanins. At 28th day, the anthocyanin content of S4 was 1.14 mg/g, which was not the highest, but the total score was the highest. Therefore, S4 was the best choice when the storage period is 28 days. This study provided technical support for the selection of a better starter for stirring yoghurt.

Leakage detection for hydraulic IGV system in gas turbine compressor with recursive ridge regression estimation

Xin Wu,Yibing Liu 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.10

The failure of the hydraulic Inlet guide vane (IGV) system needs to be avoided in the gas turbine compressor, since the IGV system is critical for the function and efficiency of the gas turbine and its fault can even cause the gas turbine to jump off the power grid. This paper investigates the detection of external and internal leakages, whose levels can be represented through corresponding leakage coefficients, at the cylinder in the hydraulic IGV system. Based on the dynamic model, we propose the recursive ridge regression parameter estimation method to detect and isolate different leakage coefficients under varying load. The developed algorithm is verified through experiments in a hydraulic IGV emulator. Based on experimental results, the proposed scheme can estimate leakage coefficients with good performance.

수력발전기술의 신개발과 조력발전 프로젝트 제안

Wu-Xin Yun 한국수자원학회 2003 한국수자원학회논문집 Vol.36 No.1

시화 조력발전소용으로는 벌브식 수차발전기가 가장 경제적인 수차형식이다. 본 고에서는, 하얼빈 전기기기 제작(주)의 수력발전 기기 설계를 포함한 전반적인 사항을 제안한다. 예비적으로 시화 조력발전소에 적용 가능한 벌브형 수차발전기에 대한 주요 인자와 일반적인 사항을 기술하고자 한다.

Effect of meridional shape on performance of axial-flow fan

Xin Chen,Linlin Cao,Peng Yan,Peng Wu,Dazhuan Wu 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.11

In this study, the effect of impeller meridional shape on the performance of axial-flow fan is investigated by CFD method. Three axialflow fan impellers with different meridional shapes are designed. The blade angle, blade stacking condition and other structure factors of the impellers are all remained consistent. The performance curves of the three impellers are calculated and compared. In almost all the interested flowrate range, the impeller W3 with an inverted-isosceles-trapezoid meridional shape and the longer blade camber achieves both the higher pressure rise and the higher efficiency than the other two impellers. A two-stage axial-flow fan designed on basis of W3 is manufactured and tested. Test results show good agreement with the calculated performance curves. Further, analyses of the CFD results are conducted to reveal the reasons for the different performance. A newly-defined Local Euler head (LEH) is introduced to represent the distribution of the major Euler work in the axial-flow fan. And the LEH distributions in the three impellers are obtained. W3 achieves the highest LEH at blade Trailing edge (TE), because it could perform the most Euler work to the fluid with the longest blade camber. Then losses in the impellers are analyzed by means of the entropy generation. Among the losses in impeller, the tip leakage loss and endwall friction loss are dominated at design flowrate. The generation condition of the tip leakage loss shows significant differences among the three impellers. And the whole power loss in impeller of W3 is slightly higher than those of the other two models. However, the power loss difference among the three impellers is negligible. And due to the highest shaft power, the efficiency loss of W3 is the lowest of all.

Surge detection methods using empirical mode decomposition and continuous wavelet transform for a centrifugal compressor

Xin Wu,Yibing Liu,Rui Liu,Li Zhao 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.4

The occurrence of surge in a centrifugal compressor results in large oscillations in pressure and flow. To avoid damaging the compressor because of surge, we develop several surge detection methods in this study. Considering the incipient surge phenomenon, the Empirical mode decomposition (EMD) and the Morlet Continuous wavelet transform (CWT) methods are selected. Both methods are validated through experimental data collected from surge tests conducted on the three-stage Ingersoll-Rand Centac centrifugal compressor at Toyota Motor Manufacturing in Kentucky, USA. For incipient surge detection, the EMD-based method can determine the threshold 1 sec earlier than the Morlet CWT-based method. Therefore, the EMD method can be used to implement the incipient surge detection scheme on the tested centrifugal compressor for safety considerations.

Passive Ranging Based on Planar Homography in a Monocular Vision System

( Xin-mei Wu ),( Fang-li Guan ),( Ai-jun Xu ) 한국정보처리학회 2020 Journal of information processing systems Vol.16 No.1

Passive ranging is a critical part of machine vision measurement. Most of passive ranging methods based on machine vision use binocular technology which need strict hardware conditions and lack of universality. To measure the distance of an object placed on horizontal plane, we present a passive ranging method based on monocular vision system by smartphone. Experimental results show that given the same abscissas, the ordinatesis of the image points linearly related to their actual imaging angles. According to this principle, we first establish a depth extraction model by assuming a linear function and substituting the actual imaging angles and ordinates of the special conjugate points into the linear function. The vertical distance of the target object to the optical axis is then calculated according to imaging principle of camera, and the passive ranging can be derived by depth and vertical distance to the optical axis of target object. Experimental results show that ranging by this method has a higher accuracy compare with others based on binocular vision system. The mean relative error of the depth measurement is 0.937% when the distance is within 3 m. When it is 3-10 m, the mean relative error is 1.71%. Compared with other methods based on monocular vision system, the method does not need to calibrate before ranging and avoids the error caused by data fitting.

Angiostrongylus cantonensis: Scanning Electron Microscopic Observations on the Cuticle of Moulting Larvae

Xin Zeng,Jie Wei,Feng Wu,Feng Fung,Xiaoying Wu,Xi Sun,Huanqing Zheng,Zhiyue Lv,Zhongdao Wu 대한기생충학열대의학회 2013 The Korean Journal of Parasitology Vol.51 No.6

UHRF2 mRNA Expression is Low in Malignant Glioma but Silencing Inhibits the Growth of U251 Glioma Cells in vitro

Wu, Ting-Feng,Zhang, Wei,Su, Zuo-Peng,Chen, San-Song,Chen, Gui-Lin,Wei, Yong-Xin,Sun, Ting,Xie, Xue-Shun,Li, Bin,Zhou, You-Xin,Du, Zi-Wei Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.10

UHRF2 is a member of the ubiquitin plant homeo domain RING finger family, which has been proven to be frequently up-regulated in colorectal cancer cells and play a role as an oncogene in breast cancer cells. However, the role of UHRF2 in glioma cells remains unclear. In this study, we performed real-time quantitative PCR on 32 pathologically confirmed glioma samples (grade I, 4 cases; grade II, 11 cases; grade III, 10 cases; and grade IV, 7 cases; according to the 2007 WHO classification system) and four glioma cell lines (A172, U251, U373, and U87). The expression of UHRF2 mRNA was significantly lower in the grade III and grade IV groups compared with the noncancerous brain tissue group, whereas its expression was high in A172, U251, and U373 glioma cell lines. An in vitro assay was performed to investigate the functions of UHRF2. Using a lentivirus-based RNA interference (RNAi) approach, we down-regulated UHRF2 expression in the U251 glioma cell line. This down-regulation led to the inhibition of cell proliferation, an increase in cell apoptosis, and a change of cell cycle distribution, in which S stage cells decreased and G2/M stage cells increased. Our results suggest that UHRF2 may be closely related to tumorigenesis and the development of gliomas.