Wavelet Transform-based Identification of Vibration Fault Signals in Rotating Machinery

Yaping Zhao 대한전자공학회 2023 IEIE Transactions on Smart Processing & Computing Vol.12 No.4

The study of fault identification of vibration signals from rotating machinery is essential for enhancing industrial production safety. A method combining a capsule network and frequency-slicing wavelet transform is proposed to improve the fault identification accuracy, considering the problem that the original vibration signal of rotating machinery carries multiple noises. The capsule network learning model was also optimized using a dynamic weighting method based on the channel attention mechanism, considering the variable operating conditions of rotating machinery. The dynamic weighting algorithm based on the channel attention mechanism used in the study achieved the highest fault recognition rates, with 99.65%, 99.25%, and 99.90% on sensor 1, sensor 2, and feature fusion data, respectively. Hence, the proposed model for fault identification in rotating machinery vibration signals is superior to other models.

Insulated Interlayer for Efficient and Photostable Electron-Transport-Layer-Free Perovskite Solar Cells

Zhao, Pengjun,Han, Manhyung,Yin, Wenping,Zhao, Xing,Kim, Seul Gi,Yan, Yaping,Kim, Minwoo,Song, Young Jae,Park, Nam Gyu,Jung, Hyun Suk American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.12

<P>Currently, the most efficient perovskite solar cells (PSCs) mainly use planar and mesoporous titanium dioxide (TiO<SUB>2</SUB>) as an electron-transport layer (ETL). However, because of its intrinsic photocatalytic properties, TiO<SUB>2</SUB> can decompose perovskite absorber and lead to poor stability under solar illumination (ultraviolet light). Herein, a simplified architectural ETL-free PSC with enhanced efficiency and outstanding photostability is produced by the facile deposition of a bathocuproine (BCP) interlayer. Power conversion efficiency of the ETL-free PSC improves from 15.56 to 19.07% after inserting the BCP layer, which is the highest efficiency reported for PSCs involving an ETL-free architecture, versus 19.03% for the n-i-p full device using TiO<SUB>2</SUB> as an ETL. The BCP interlayer has been demonstrated to have several positive effects on the photovoltaic performances of devices, such as “modulation doping” of the perovskite layer, modification of FTO surface work function, and enhancing the charge-transfer efficiency between FTO and perovskite. Moreover, the BCP-based ETL-free devices exhibit outstanding photostability: the unencapsulated BCP-based ETL-free PSCs retain over 90% of their initial efficiencies after 1000 h of storage in air and maintain 92.2% after 450 h of exposure to full solar irradiation (without a UV filter), compared to only 14.1% in the n-i-p full cells under the same condition.</P> [FIG OMISSION]</BR>

Antioxidant and Anti-hyperglycemic Activity of Polysaccharide Isolated from Dendrobium chrysotoxum Lindl

Zhao, Yaping,Son, Young-Ok,Kim, So-Soon,Jang, Yong-Suk,Lee, Jeong-Chae Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.5

Although polysaccharide is believed to play an important role in the medicinal effect of Dendrobium chrysotoxum Lindl (DCL), its role as an antioxidant and in anti-hyperglycemic induction was not reported. In this study, polysaccharide with molecular weight of approximately 150 kDa, herein named DCLP, was isolated from the stem of DCL, and its antioxidative, hypoglycemic and immune stimulating effects were evaluated using various in vitro and in vivo assay systems. DCLP inhibited hydroxyl radicals ($^{\cdot}$OH)-mediated deoxyribose degradation by scavenging hydroxyl radicals directly as well as by chelating iron ions. DCLP also showed dose-dependent scavenging activity on superoxide anions ($O_2^{{\cdot}-}$) and offered significant protection (p < 0.001) against glucose oxidase-mediated cytotoxicity in Jurkat cells. DCLP had immune stimulating effects, as evidenced by the DCLP-mediated increases in the level of DNA synthesis, viability, and cytokine secretion in mouse lymphocytes. Moreover, oral administration of DCLP produced a significant reduction in blood glucose level in alloxan-induced diabetic mice. These findings suggest that DCLP has a potential utility in treating patients who require enhanced antioxidation, immune function and/or hypoglycemic activity.

Effects of Antioxidant Tempol on Systematic Inflammation and Endothelial Apoptosis in Emphysematous Rats Exposed to Intermittent Hypoxia

Haiyan Zhao,Yaping Zhao,Xin Li,Leiqian Xu,Fangxin Jiang,Wanju Hou,Lixia Dong,Jie Cao 연세대학교의과대학 2018 Yonsei medical journal Vol.59 No.9

Purpose: Obstructive sleep apnea and chronic obstructive pulmonary disease are independent risk factors of cardiovascular disease(CVD), and their coexistence is known as overlap syndrome (OS). Endothelial dysfunction is the initial stage of CVD; however,underlying mechanisms linking OS and CVD are not well understood. The aim of this study was to explore whether OS canlead to more severe inflammation and endothelial apoptosis by promoting endothelial dysfunction, and to assess the interventioneffects of antioxidant tempol. Materials and Methods: Male Wistar rats (n=66) were exposed to normal oxygen [normal control (NC) group], intermittent hypoxia(IH group), cigarette smoke (CH group), as well as cigarette smoke and IH (OS group). Tempol intervention was assessed inOS group treated with tempol (OST group) or NaCl (OSN group). After an 8-week challenge, lung tissues, serum, and fresh bloodwere harvested for analysis of endothelial markers and apoptosis. Results: The levels of intracellular adhesion molecule-1, vascular cellular adhesion molecule-1, and apoptosis in circulating epithelialcells were the highest in OS group and the lowest in NC group. These levels were all greater in IH group than in CH group,and were lower in OST group than in OS and OSN groups (all p<0.001). Conclusion: Synergistic effects of IH with cigarette smoke-induced emphysema produce a greater inflammatory status and endothelialapoptosis. OS-related inflammation and endothelial cell apoptosis may play important roles in promoting cardiovasculardysfunction, and antioxidant tempol could achieve a partial protective effect.

Synthesis of Novel Poly(N,N-diethylacrylamide-co-acrylic acid) (P(DEA-co-AA)) Microgels as Carrier of Horseradish Peroxidase Immobilization for Pollution Treatment

Yaping Zhang,Jian Fang,Tonghuan Liu,Qiang Wang,Jihua Zhao,Weiguo Shen 한국고분자학회 2012 Macromolecular Research Vol.20 No.5

A series of temperature-sensitive N,N-diethylacrylamide-co-acrylic acid microgels were synthesized by modified surfactant-free emulsion polymerization method and characterized by Fourier transform infrared spectroscopy,turbidimetric method, scanning electron microscopy (SEM), and dynamic light scattering (DLS) measurements. The SEM images showed that the as-synthesized microgels were monodispersed as spherical particles and the average size increased from 200 to 800 nm with the mole fraction of acrylic acid (AA) increasing from 0 to 0.40. Turbidimetric analysis and DLS investigation indicated that the volume phase transition temperature and the swelling ratio of the microgels had an upward trend that was associated with the higher incorporation of AA. Furthermore,horseradish peroxidase (HRP) was successfully immobilized on the microgel with the greatest swelling ratio (the mole fraction of AA equal to 0.40) to obtain an enzyme-microgel complex for the treatment of wastewater polluted by phenolic compounds. The immobilized HRP achieved a high removal efficiency of >96% toward phenol and was more thermostable and more easily stored and reused compared with free HRP.

Experimental Study on the Seismic Mechanism of Full-scale Specimens of Superimposed Slab Shear Walls with Innovative Construction Details

Hongkang Zhao,Yaping Dai,Jun Yang,Youzhen Fang,Chengjie Mi,Lingchen Yang,Guojian Li 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.6

The seismic performance of precast reinforced concrete structures has long been a source ofconcern that impedes their use in seismic regions and high-rise buildings. To further optimizethe reinforcement configuration and enhance the seismic performance of the superimposedslab shear wall structures, this research proposed a superimposed slab shear wall withinnovative construction details. Five innovative superimposed slab shear walls and one cast-inplaceconcrete shear wall were designed and tested under low cycle lateral load. The effect ofaxial compression was considered during tests and analyses as well. In this paper, the seismicperformance, including failure mode, hysteretic behavior, load-bearing capacity, lateralstiffness degradation, energy dissipation, and seismic ductility was investigated and analyzed. The experimental results showed that five innovative superimposed slab shear walls and onecast-in-place concrete shear wall exhibited a similar failure mode of flexural-shear failure, anda large area of concrete was damaged and crushed at the shear wall corner. However, the areaof crushing concrete in the cast-in-place concrete shear wall was relatively small. And the areaof crushing concrete in the superimposed slab shear walls increased with the axial compressionratio. For the superimposed slab shear walls, the development of concrete cracks decreasedgradually with the enlargement in the axial compression ratio, while the length of the cracksincreased in this respect. The results indicated that innovative superimposed slab shear wallshad a higher strength capacity and lower lateral-resistant stiffness than the cast-in-placeconcrete shear wall. With the enlargement in the axial compression ratio, the peak strengthcapacity of the superimposed slab shear wall increased obviously, while it degraded rapidlyafter the peak load. It is suggested that the contribution of axial compression to the shear resistcapacity of the inclined section should not be considered in practical design. Meanwhile, theductility coefficients of the six specimens were larger than 2.2, which was in accordance withthe seismic requirements. This investigation could provide effective experimental data forfuture structural seismic performance evaluations and applications of precast superimposedslab shear wall structures.

Quantitative Simulation Severe Asian Dust Storm on 9-11 April 2006

Linna Zhao,Jianhua Sun,Yaping Shao 한국기상학회 2006 한국기상학회 학술대회 논문집 Vol.2006 No.-

Corporate social responsibility disclosure and catering to investor sentiment in China

Sun, Weizhang,Zhao, Chunguang,Wang, Yaping,Cho, Charles H. Emerald (MCB UP ) 2018 MANAGEMENT DECISION Vol.56 No.9

Manufacturing Principle and Meshing Limit Line of Toroidal Surface Enveloping Cylindrical Worm Drive with Arc-Toothed Worm

Xinyue Zhu,Yaping Zhao,Yifei Chi,Gongfa Li,Xinyuan Chen 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.23 No.3

The main purpose of this article is to determine the processing parameters of the worm and establish the theory of the meshing limit line of toroidal surface enveloping cylindrical worm drive with the arc-toothed worm. Based on this condition that the instantaneous contact line is a planar curve during grinding the worm blank, it can be deduced that its torsion is equal to zero, then the formulae which determine the installing position of the grinding wheel are acquired. Following this, the equations of the tooth surfaces and the meshing limit function are all obtained. According to the geometric construction and elimination method, the meshing limit points are determined by iteratively solving the corresponding nonlinear equation in its solution domain. In addition, the result of the numerical case demonstrates that the worm helicoid is divided into two parts by the meshing limit line, which makes the working length of the worm cannot reach half of its total thread length. And by adjusting the design parameters of the worm pair and the processing parameters of the worm, the meshing limit line cannot be eliminated and its position on the surfaces of the worm and the worm gear has no notable change.

Effect of activated persulfate on the properties of contaminated soil and degradation behavior of PAHs

Yamin Hong,Xiupeng Yue,Yaping Zhang,Kai Shen,Wentao Jiao,Lei Zhao,Beibei Li 대한환경공학회 2023 Environmental Engineering Research Vol.28 No.3

Sulfate radical-based advanced oxidation processes have been applied in the remediation of polycyclic aromatic hydrocarbons (PAHs) contaminated soil, during which sulfate can be activated in different ways. In this work, effects of four different ways (FeSO4, NaOH, H2O2, and Heat) activated sodium persulfate (PS) on PAHs removal and soil physicochemical properties (pH, organic matter, functional groups, surface morphology, and partial heavy metal elements) were compared, and the influencing factors and mechanism of soil PAHs removal by thermally activated PS were also studied. The results showed that at the dosage of 3% of persulfate, the removal efficiency of PAHs followed the sequences of Heat (91.4%) > FeSO4 (86.6%) > H2O2 (86.2%) > NaOH (72.9%). However, thermal activation decreased the soil pH and organic matter content more significantly than other treatments. The reaction tended to reach equilibrium at 6 h when the dosage of persulfate was 3% and the activation temperature was 60 °C, and the reaction obeyed pseudo-first-order kinetics. Through quenching experiments, it was found that the free radicals playing a dominant role in the oxidation process were sulfate radicals. Compared with pH, liquid to soil (L/S ratio) and the temperature had more significant impacts on the degradation efficiency of PAHs.