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      • KCI등재

        Differences in Functional Fitness Among Older Adults With and Without Risk of Falling

        Yanan Zhao,Pak-Kwong Chung 한국간호과학회 2016 Asian Nursing Research Vol.10 No.1

        Purpose: This study aimed to identify the differences in functional fitness between older adults who were at risk of falling and those who were not. Methods: A total of 104 older adults aged 65-74 years were recruited from a local community senior center. They were independent older adults without a history of falls in the preceding 12 months. Falling risk status was assessed using the Fall Risk Test. Five dimensions of functional fitness with seven testing parameters (i.e., 30-second chair stand test, 30-second arm curl test, 2-minute step test, chair sit and reach test, back scratch test, 8-foot up and go test, and body mass index) were evaluated by the Senior Fitness Test. Results: Only 78 participants completed all the tests, of which 48 participants were identified with risk of falling, and 30 participants were free from risk of falling. Results from multivariate analysis of variance found significant differences on the combined outcome variables, especially in the 8-foot up and go test, 2-minute step test, and 30-second arm curl test. Results from discriminant analysis found a significant discriminant function among all the seven testing parameters, where the 8-foot up and go test, and the 2-minute step test contributed most. Conclusions: Older adults who are at the early stage of risk of falling tend to have lower functional fitness capacities, especially in agility and dynamic balance, aerobic endurance as well as in a combined relationship among all the testing parameters.

      • KCI등재

        Cuprum Metal-Organic-Framework and Polyacrylonitrile-Derived Cu-N-C Electrocatalyst for Application in Zinc-Air Batteries

        Yajun Zhao,Jintao Chen,Xiaorui Li,Jiaqing Zhang,Yanan Li,Yajun Zhao,Liye Cao,Xiaoshi Jin 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2020 NANO Vol.15 No.02

        Cu-N-C electrocatalyst was successfully prepared with Cu-BTC and polyacrylonitrile as templates by electrospinning and in-situ growth method. The effect of various N-doped content on the electrochemical performance of the catalyst were investigated and the Cu-N-C-0.25 exhibited the best OER/ORRcatalytic activities. When it was applied to the cathode of the zinc-air batteries, the power density of Cu-N-C-0.25 was 209.1 mW cm -2, which exceeded that of the commercial Pt/C + IrO2 hybrid catalyst (157 mW cm -2). The excellent electrochemical performance may be attributed to large number of active sites and high specific surface area on Cu-N-C electrocatalyst. It will be a promising alternative to precious metal catalysts containing Pt, Ir or Ru and their oxides.

      • KCI등재

        Quantitative evaluation of through-thickness rectangular notch in metal plates based on lamb waves

        Na Zhao,Bin Wu,Xiucheng Liu,Keqin Ding,Yanan Hu,Mahmoud Bayat 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.71 No.6

        Lamb wave technology is a promising technology in the field of structural health monitoring and can be applied in the detection and monitoring of defects in plate structures. Based on the reconstruction algorithm for the probabilistic inspection of damage (RAPID), a Lamb-based detection and evaluation method of through-thickness rectangular notches in metal plates was proposed in this study. The influences of through-thickness rectangular notch length and the angle between sensing path and notch length direction on signals were further explored through simulations and experiments. Then a damage index calculation method which focuses on both phase and amplitude difference between detected signals and baseline signals was proposed. Based on the damage index difference between two vertically crossed sensing paths which pass through the notch in a sensor network, the notch direction identification method was proposed. In addition, the notch length was determined based on the damage index distribution along sensing paths. The experimental results showed that the image reconstructed with the proposed method could reflect the information for the evaluation of notches.

      • KCI등재

        Preparation and Characterization of Sulfated TiO2/zeolite Composite Catalysts with Enhanced Photocatalytic Activity

        Yuan Zhao,JingXiu Li,Ling Wang,Yanan Hao,Lin Yang,Pingting He,JianJun Xue 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.10

        Sulfated TiO2 nanoparticles were successfully immobilized on zeolite through improving hydrolysis-deposition method. Microstructure, crystallization, surface state and surface area of composite catalysts were characterized by SEM, XRD, FTIR spectra, XPS and BET and the photocatalytic activity was evaluated by degradation of methyl orange under UV irradiation. We optimized these factors (SO4 -2) ions, calcination temperature and loading amount of sulfated TiO2) on photocatalytic activity and crystallization of composite photocatalysts. The results indicated that the SO4 -2 ) ions are successfully immobilized on the surface of TiO2, and sulfated TiO2/zeolite show the highest photocatalytic activity for methyl orange at the [SO4 -2]/[Ti4+] molar rate of 1:1, calcination temperature of 600 ℃ for 2 h, and sulfated TiO2 loading amount of 40%, respectively.

      • KCI등재

        Temperature dependent defence of Nicotiana tabacum against Cucumber mosaic virus and recovery occurs with the formation of dark green islands

        Feifei Zhao,Yanan Li,Li-juan Chen,Lisha Zhu,Han Ren,Honghui Lin,Dehui Xi 한국식물학회 2016 Journal of Plant Biology Vol.59 No.3

        Temperature is an important environmental factor controlling plant growth, development, and immune response. However, the role of temperature in plant disease resistance is still elusive. In the present study, the potential effects of temperature on the interaction between Nicotiana tabacum and Cucumber mosaic virus (CMV) were investigated. Our results indicated that N. tabacum plants displayed severe symptoms at early stage of post inoculation at high temperature (HT, 28°C), associated with higher viral replication level, more serious stress damages. By contrast, low temperature (LT, 18°C) effectively delayed the replication of CMV compared with elevated temperatures. Additionally, quantitative real-time PCR analyses revealed that lower temperatures (≤ 24°C) promote salicylic acid (SA) dependent responses, whereas higher temperatures (> 24°C) activate the genes expression of jasmonic acid (JA) pathway. Interestingly, the dark green islands (DGIs) appeared much earlier in CMV-inoculated plants grown at HT compared with those at LT and the accumulation of virus small interfering RNAs in plants were significantly up-regulated under elevated temperatures at early stage of post inoculation. Taken together, these results indicated that temperature changes had important effects on plant defence response, and different temperatures could induce different immune pathways of N. tabacum against CMV infection.

      • KCI등재

        Variable Impedance Control of Cable Actuated Continuum Manipulators

        Guangping He,Yanan Fan,Tingting Su,Lei Zhao,Quanliang Zhao 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.7

        Continuum manipulators are a class of special compliant robots that have important potential applications in the field of human-machine interactive operations, or work in cluttered and constrained environments. In these application scenarios, the most popular operation tasks are those with coupling force-position constraints. To simultaneously stabilize the desired operation force and the position of the manipulator, variable impedance control issues of the cable driven continuum manipulators are investigated in this paper. On the basis of constructing a novelLyapunov function, a variable impedance control law is presented and the stability of the closed-loop system has also been analyzed. Then the operation space variable impedance control for a single segment cable driven continuum manipulator is realized by the aid of a pseudo-rigid-body model. Some numerical simulations also demonstrate the stability of the variable impedance control system.

      • KCI등재

        Multilayer-Structured Poly-Vanadium Acid/Polyaniline Composite: Synthesis and Properties for Humidity Sensing

        Li Li,Yanan Guo,Chao Zhao,Liyuan Song 한국고분자학회 2018 Macromolecular Research Vol.26 No.7

        A high-performance humidity sensor based on multilayer-structured poly-vanadium acid/polyaniline (V/PANI) composite was reported in this paper. Two-layer-structured V/PANI composite was fabricated by dip-coating poly-vanadium acid and electrochemically polymerizing PANI onto the interdigitated gold electrode in sequence, and then the process could be repeated to prepare the second two-layer-structured V/PANI composite. The crystalline phase properties and structural characteristics of the poly-vanadium acid, PANI, and V/PANI composite were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy, and UV-visible spectroscopy, respectively. The morphological characteristics of the first two-layer-structured V/PANI composite and multilayer-structured V/PANI composite were characterized by scanning electron microscopy. Additionally, sensors based on the multilayer-structured V/PANI composite showed good humidity sensing properties. For instance, its impedance changed linearly for approximately four orders of magnitude in a wide range of 11-97% RH. Furthermore, it displayed small hysteresis (∼5%RH), fast response (t90% of 8 s and 12 s for adsorption and desorption processes, respectively), good stability. The possible sensing mechanism was analyzed by considering the special multilayer structure and using complex impedance spectra and the corresponding equivalent circuit of the sensor. The measurement results highlight the multilayer-structured V/PANI composite film is a candidate material for constructing humidity sensors.

      • KCI등재

        Morphology characterization of micro-gap oil film of tilting pad hydrostatic bearing under extreme working conditions

        Xiaodong Yu,Yanan Feng,Yan Zhao,Dianbin Huang,Jianhua Jiao 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.12

        Taking the hydrostatic support of the tiltable oil pad double rectangular cavity as the object, the fluid-thermal-solid coupling deformation analysis of the friction pair is carried out, and the three-dimensional morphology of the micro-gap oil film is obtained. An oil film thickness test device is built to verify the rationality of the numerical simulation method. It is found that the elastic deformations of rotational workbench and base under extreme loads are both concave deformations, the thermal deformations are both convex deformations, and the maximum thermal deformation is mainly concentrated on the outer oil sealing edge. The deformation of the downstream side oil sealing edge is higher than that of the reverse side oil sealing edge. The minimum oil film thickness is the minimum distance between the downstream side oil sealing edge and the lower surface of the hydrostatic guideway of the rotational workbench, where tribological failure is prone to occur.

      • KCI등재

        Feasibility Study on Long-Term Continuous Ethanol Production from Cassava Supernatant by Immobilized Yeast Cells in Packed Bed Reactor

        Liu Qingguo,Zhao Nan,Zou Yanan,Ying Hanjie,Dong Liu,Chen Yong 한국미생물·생명공학회 2020 Journal of microbiology and biotechnology Vol.30 No.8

        In this study, yeast cell immobilization was carried out in a packed bed reactor (PBR) to investigate the effects of the volumetric capacity of carriers as well as the different fermentation modes on fuel ethanol production. An optimal volumetric capacity of 10 g/l was found to obtain a high cell concentration. The productivity of immobilized cell fermentation was 16% higher than that of suspended-cell fermentation in batch and it reached a higher value of 4.28 g/l/h in repeated batches. Additionally, using this method, the ethanol yield (95.88%) was found to be higher than that of other tested methods due to low concentrations of residual sugars and free cells. Continuous ethanol production using four bioreactors showed a higher productivity (9.57 g/l/h) and yield (96.96%) with an ethanol concentration of 104.65 g/l obtained from 219.42 g/l of initial total sugar at a dilution rate of 0.092 h-1. Furthermore, we reversed the substrate-feed flow directions in the in-series bioreactors to keep the cells at their highest activity and to extend the length of continuous fermentation. Our study demonstrates an effective method of ethanol production with a new immobilized approach, and that by switching the flow directions, traditional continuous fermentation can be greatly improved, which could have practical and broad implications in industrial applications.

      • KCI등재

        Public Key Encryption with Equality Test for Heterogeneous Systems in Cloud Computing

        ( Rashad Elhabob ),( Yanan Zhao ),( Iva Sella ),( Hu Xiong ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.9

        Cloud computing provides a broad range of services like operating systems, hardware, software and resources. Availability of these services encourages data owners to outsource their intensive computations and massive data to the cloud. However, considering the untrusted nature of cloud server, it is essential to encrypt the data before outsourcing it to the cloud. Unfortunately, this leads to a challenge when it comes to providing search functionality for encrypted data located in the cloud. To address this challenge, this paper presents a public key encryption with equality test for heterogeneous systems (PKE-ET-HS). The PKE-ET-HS scheme simulates certificateless public encryption with equality test (CLE-ET) with the identity-based encryption with equality test (IBE-ET). This scheme provides the authorized cloud server the right to actuate the equivalence of two messages having their encryptions performed under heterogeneous systems. Basing on the random oracle model, we construct the security of our proposed scheme under the bilinear Diffie-Hellman (BDH) assumption. Eventually, we evaluate the size of storage, computation complexities, and properties with other related works and illustrations indicate good performance from our scheme.

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