Novelty detection methods for online health monitoring and post data analysis of turbopumps

Hu Lei,Hu Niaoqing,Zhang Xinpeng,Gu Fengshou,Gao Ming 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.7

As novelty detection works when only normal data are available, it is of considerable promise for health monitoring in cases lacking fault samples and prior knowledge. We present two novelty detection methods for health monitoring of turbopumps in large-scale liquidpropellant rocket engines. The first method is the adaptive Gaussian threshold model. This method is designed to monitor the vibration of the turbopumps online because it has minimal computational complexity and is easy for implementation in real time. The second method is the one-class support vector machine (OCSVM) which is developed for post analysis of historical vibration signals. Via post analysis the method not only confirms the online monitoring results but also provides diagnostic results so that faults from sensors are separated from those actually from the turbopumps. Both of these two methods are validated to be efficient for health monitoring of the turbopumps.

Efficient hydrolysis of cellulose over a magnetic lignin-derived solid acid catalyst in 1-butyl-3-methylimidazolium chloride

Lei Hu,Zhen Wu,Jiaxing Xu,Shouyong Zhou,Guodong Tang 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.4

A green and efficient strategy for the hydrolysis of cellulose was developed by using a magnetic lignin-derived solid acid catalyst (MLC-SO3H) in the presence of ionic liquid 1-butyl-3-methylimidazolium chloride ([BMIM]Cl). The results indicated that reaction temperature, reaction time, catalyst loading and water content have a big influence on the yield of total reducing sugars (TRS). By optimizing these reaction parameters, 69.3% TRS yield was observed at 140 oC for 150 min with the addition of 40 wt% MLC-SO3H and 1 wt% water. More importantly, MLC-SO3H could be easily separated from the reaction mixture with an external magnet and could be repeatedly used five times without an obvious loss of catalytic activity, demonstrating that it possessed excellent recyclability. Furthermore, a plausible mechanism involving three consecutive processes of dissolution, adsorption and catalysis for the hydrolysis of cellulose in [BMIM]Cl over a catalyst of MLC-SO3H was also proposed.

Melatonin Attenuates Noise Stress-induced Gastrointestinal Motility Disorder and Gastric Stress Ulcer: Role of Gastrointestinal Hormones and Oxidative Stress in Rats

( Lei Zhang ),( Ji T Gong ),( Hu Q Zhang ),( Quan H Song ),( Guang H Xu ),( Lei Cai ),( Xiao D Tang ),( Hai F Zhang ),( Fang E Liu ),( Zhan S Jia ),( Hong W Zhang ) 대한소화기기능성질환·운동학회 2015 Journal of Neurogastroenterology and Motility (JNM Vol.21 No.2

Background/Aims There are increasing evidences for gastrointestinal motility disorder (GIMD) and gastric stress ulcer induced by noise stress. The present study was to investigate the reversed effect of melatonin on GIMD and gastric stress ulcer induced by noise stress and potential mechanism. Methods Noise stress was induced on rats, and melatonin (15 mg/kg) was administered to rats by intraperitoneal injection. Differences were assessed in gastric residual rate (GRR), small intestine propulsion rate (SPR), Guth injury score, cortisol, gastrointestinal hormones (calcitonin-gene-related peptide and motilin) and oxidative stress markers (superoxide dismutase and malondialde hyde) in blood plasma as well as gastric mucosa homogenate with or without melatonin. The pathological examination of gastric mucosa was also performed. Results The GRR and SPR were improved by noise stress compared with control (P < 0.05). The pathological examination and Guth injury score revealed gastric stress ulcer. Moreover, the levels of cortisol, motilin and malondialdehyde in blood plasma and malondialdehyde in gastric mucosa homogenate were increased by noise stress (P < 0.05). CGRP and superoxide dismutase activity in both of blood plasma and gastric mucosa homogenate were significantly decreased (P< 0.05). Furthermore, melatonin reversed changes in GRR, SPR, pathological examination, Guth injury score, cortisol, motilin, CGRP, superoxide dismutase activity and malondialdehyde (P < 0.05). Conclusions Melatonin is effective in reversing the GIMD and gastric stress ulcer induced by noise stress. The underlying mechanism may be involved in oxidative stress and gastrointestinal hormones. (J Neurogastroenterol Motil 2015;21:189-199)

Selective transformation of biomass-derived 5-hydroxymethylfurfural into 2,5-dihydroxymethylfuran via catalytic transfer hydrogenation over magnetic zirconium hydroxides

Lei Hu,Mei Yang,Ning Xu,Jiaxing Xu,Shouyong Zhou,Xiao-Zhong Chu,Yijiang Zhao 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.1

An economical and effective approach for the selective transformation of biomass-derived 5-hydroxymethylfurfural (HMF) into 2,5-dihydroxymethylfuran (DHMF) was developed by catalytic transfer hydrogenation over various magnetic zirconium hydroxides (MZHs). As expected, MZH with a moderate Zr/Fe molar ratio of 2 displayed the highest catalytic activity, resulting in 98.4% HMF conversion and 89.6% DHMF yield at 150 oC for 5 h in the presence of 2-butanol that simultaneously acted as the hydrogen donor and reaction solvent, which was ascribed to its appropriate specific surface area, pore size and acid-base content. Moreover, a plausible reaction mechanism for the catalytic transfer hydrogenation of HMF into DHMF over MHZ(Zr/Fe=2) was also proposed, in which the basic hydroxyl groups with the aid of acidic zirconium metal centers were considered to be responsible for the pivotal hydride transfer via a six-membered ring structure.

A novel recyclable nano-adsorbent for enhanced oil recovery with efficient removal of Ca2+ and Cr6+ from oilfield wastewater

Lei He,Yong Dai,Zhe Wang,Lutao Yang,Luxia Zhang,Pengpeng Hu,Yutian Lei,Hong Mo,Haomiao Zhu,Jun Zhang 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.8

Oilfield wastewater has a significantly negative influence on the recovery efficiency due to its hypersalinity. Therefore, magnetic graphene oxide (GO) modified with ethylene diamine tetraacetic acid (EDTA) and grafted bypolyethylene glycol (PEG) nano-adsorbent was prepared to remove the Ca2+ and Cr6+ in Jidong Oilfield wastewaterspecifically. It was noteworthy that PEG-g-EDTA/Fe3O4/GO nano-adsorbent had excellent adsorption performance,with removal ratios up to 71.6% for Ca2+ and 42.7% for Cr6+ at 30 min. After the fifth recycling run, the nano-adsorbentstill remained with high removal ratios (69.3% for Ca2+ and 30.5% for Cr6+) and high reuse rates (89.4% for Ca2+and 95.2% for Cr6+), indicating that the nano-adsorbent had outstanding adsorption-desorption efficacy and high reusability. The adsorption test results demonstrated that the total salinity of the treated oilfield wastewater decreased byabout 5,000 ppm, and the displacement efficiency further increased by 12.5% by chemical flooding compared with theuntreated wastewater. Therefore, PEG-g-EDTA/Fe3O4/GO nano-adsorbent is an adsorbent with excellent potentialwhich can effectively remove Ca2+ and Cr6+ in oilfield wastewater to enhance oil recovery (EOR).

The Input-output’s Control Strategy of the Fashion Company

Lei Jiang,Shouzhong Hu,Bingqiang Tian 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.1

This paper deals with the problems of control strategy of the fashion company. The input-output model is founded based on the singular stochastic dynamic Leontief input-output model. A new mathematic method is applied to study the singular systems without converting them into general linear systems. The parameter uncertainties are considered and are assumed to be time-invariant and Markovian jumping. A new stability criterion for singular system is given to ensure the robust stability of singular input-output model in terms of linear matrix inequality. Finally, the corresponding computer control algorithm is provided.

A Novel Kinetic Analysis of Crystallization of Polypropylene (PP) in Dynamically-vulcanized PP/Ethylene-propylene-diene Rubber (EPDM) Blends Using an In-situ Measurement Technique

Lei Hu,Bin Yang,Yan-Li Deng,Fei-Xue Lu,Ru Xia,Zheng-Zhi Zheng,Ji-Bin Miao,Jia-Sheng Qian,Chuan-Ru Zhang,Peng Chen,Yu-Chuan Zhang 한국고분자학회 2017 폴리머 Vol.41 No.4

The effects of cooling medium temperatures and plastic/rubber ratios on solidification and crystallization kinetics of dynamically-vulcanized polypropylene/ethylene-propylene-diene rubber (PP/EPDM) blends were investigated with the aid of an in-situ measurement technique. The cooling medium temperature heavily influenced the solidification kinetics primarily due to a combination of latent heat liberated from the molten polymer and the heat transferred away via the metallic wall during the cooling period. Interestingly, the parameter C in three-parameter model was not only affected by the material properties, but also by the cooling condition, different from the previous literature. The crystallization kinetics analysis indicated that the effect of EPDM in the blends consisted of both nucleation-promoting effect (low EPDM loading) and steric effect (higher EPDM loading). The present kinetic analysis may be helpful to further studies on improving the product performances for industrial applications.

Energy-saving Methods in the Operation of Virtual Networks Based on Divided Time Slices

HU Ying,ZHUANG Lei,HU Yu-xiang,MA Ding 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.7

Reducing energy consumption has also become an important way to reduce expenditures and increase revenue for ISP. For solving the problem of dynamically changing network-flow of virtual network in runtime, we first analyze relations and differences between virtual network and IP network on energy-saving issues. We secondly model the makeup of energy consumption in virtual network, and determine the object of energy-saving in virtual network at. Finally we propose the solutions to this energy-saving problem. The solutions can be described as follows: (1) based on the historical data of daily network-flow, we divide one day into two time slices, and one is called idle time slice, the other is called busy time slice; (2) we design the dynamic switch-off algorithm and run it at the beginning of idle time slice, and we use former algorithms to be started at the beginning of busy time slice; (3) in the dynamic switch-off algorithm we determine the method to select virtual networks and the method to remap; (4) we apply roulette wheel to select virtual networks, in the selection method we consider both current influences on energy-saving and influences in the future. Simulation results show that the dynamic switch-off algorithm can effectively select virtual networks, and the whole solution performs well in energy aware virtual network in runtime.

Transcriptome reveals genes involving in black skin color formation of ducks

Lei Wang,Hehe Liu,Bo Hu,Jiwei Hu,Hengyong Xu,Hua He,Chunchun Han,Bo Kang,Lili Bai,Rongping Zhang,Jiwen Wang,Shengqiang Hu,Liang Li 한국유전학회 2021 Genes & Genomics Vol.43 No.2

Background Skin color is colorful for birds, which has been reported to be associated with multi-biological functions, such as crypsis, camoufage, social signaling and mate choice, but little is known about its underlying molecular mechanism. Objective Studies on the major genes afecting the black skin color of ducks. Methods For this purpose, Silver ammonia staining and RNA-seq analysis were carried out to identify the diferences in tissue morphology and gene expressions between black and yellow skin ducks. Results The silver ammonia dyes slice results showed that in the development of black duck, the content of melanin in black skin gradually increased and then decreased, and the content of melanin in yellow and black skin was signifcantly diferent. Through transcriptome, a total of 102 and 84 diferentially expressed genes (DEGs) were identifed in beak skin and web skin, respectively. These DEGs were enriched in melanin biosynthesis and play a critical role in melanogenesis pathway. Co-expression analysis showed that EDNRB2 was the only gene associated with black skin color in DEGs, which was also consistent with qRT-PCR. Conclusions The melanin synthesis pathway dominated by EDNRB2 up-regulated the amount of melanin synthesis, leading to the formation of black skin in ducks.

Chemical Composition, Antioxidant and Cytoprotective Activities of Lotus Receptacle

Weicheng Hu,Gongcheng Wang,Ting Shen,Yuning Wang,Boran Hu,Xinfeng Wang,Lei Wu,Pengxia Li,Lilian Ji 한국원예학회 2015 Horticulture, Environment, and Biotechnology Vol.56 No.5

The nutritional composition (ash, protein, fat, crude fiber, and carbohydrate) and antioxidant activity of lotus receptacles (LRs) were studied. The LRs contained 88.25% carbohydrates, 22.90% crude fiber, 5.79% crude ash, 0.77% crude protein content, and 5.19% crude lipid on a dry weight basis. The ethanolic extract of lotus receptacle (ELR) exerted strong scavenging effects on 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical, hydroxyl radical (•OH), superoxide anion (O2-), and hydrogen peroxide (H2O2), as well as high reducing power. ELR pretreatment effectively elevated cell viability and decreased malondialdehyde (MDA) levels in H2O2-treated RAW 264.7 cells. Additionally, ELR had high phenolic and flavonoid contents with values of 318.15 mg gallic acid equivalent/g and 239.06 mg rutin equivalent/g, respectively. Moreover, the bioactivity-guided study of ELR resulted in the isolation and identification of quercetin-3-O-β-D-glucopyranoside (QOG), a dietary flavonoid. QOG exhibited strong DPPH free radical scavenging activity, with an IC50 value of 24.26 μM; docking studies revealed that QOC formed one hydrogen bond with LYS263 in the active site, suggesting it is, in part, responsible for the free activity of LR.