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        검색결과 12

        2.
        2021.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Observations of line of sight (LOS) Doppler velocity and non-thermal line width in the o -limb solar corona are often used for investigating the Alfven wave signatures in the corona. In this study, we compare LOS Doppler velocities and non-thermal line widths obtained simultaneously from two di erent instruments, Coronal Multichannel Polarimeter (CoMP) and Hinode/EUV Imaging Spectrometer (EIS), on various o -limb coronal regions: aring and quiescent active regions, equatorial quiet region, and polar prominence and plume regions observed in 2012{2014. CoMP provides the polarization at the Fe xiii 10747 A coronal forbidden lines which allows their spectral line intensity, LOS Doppler velocity, and line width to be measured with a low spectral resolution of 1.2 A in 2-D o limb corona between 1.05 and 1.40 RSun, while Hinode/EIS gives us the EUV spectral information with a high spectral resolution (0.025 A) in a limited eld of view raster scan. In order to compare them, we make pseudo raster scan CoMP maps using information of each EIS scan slit time and position. We compare the CoMP and EIS spectroscopic maps by visual inspection, and examine their pixel to pixel correlations and percentages of pixel numbers satisfying the condition that the di erences between CoMP and EIS spectroscopic quantities are within the EIS measurement accuracy: 3 kms􀀀1 for LOS Doppler velocity and 9 kms􀀀1 for non-thermal width. The main results are summarized as follows. By comparing CoMP and EIS Doppler velocity distributions, we nd that they are consistent with each other overall in the active regions and equatorial quiet region (0.25  CC  0.7), while they are partially similar to each other in the overlying loops of prominences and near the bottom of the polar plume (0.02  CC  0.18). CoMP Doppler velocities are consistent with the EIS ones within the EIS measurement accuracy in most regions ( 87% of pixels) except for the polar region (45% of pixels). We nd that CoMP and EIS non-thermal width distributions are similar overall in the active regions (0.06  CC  0.61), while they seem to be di erent in the others (􀀀0:1  CC  0.00). CoMP non-thermal widths are similar to EIS ones within the EIS measurement accuracy in a quiescent active region (79% of pixels), while they do not match in the other regions ( 61% of pixels); the CoMP observations tend to underestimate the widths by about 20% to 40% compared to the EIS ones. Our results demonstrate that CoMP observations can provide reliable 2-D LOS Doppler velocity distributions on active regions and might provide their non-thermal width distributions.
        4,300원
        8.
        2017.04 서비스 종료(열람 제한)
        Visual inspection has generally been applied to examine the coating deterioration. However, it was difficult to evaluate an anti-corrosion performance of paint film. In this study, thus, to quantitatively evaluate an anti-corrosion performance of paint film under various corrosion enviornent, change in the impedance paint coating was evauated using EIS (Electrochemical Impedance Spectroscopy).
        9.
        2017.01 KCI 등재 서비스 종료(열람 제한)
        NaCl과 LiNO2의 첨가량에 따른 콘크리트에 매립된 철근의 부식거동을 전기화학적 임피던스 분광법을 이용하여 고찰하였다. 부식 가속 방법중 하나인 건습반복법을 이용하여 단기간 내에 부식현상을 촉진하였으며, 측정된 임피던스 값을 통해 등가회로를 제안할 수 있었다. NaCl 1.2 kg/m3이 첨가된 콘크리트에 매립된 철근의 부동태 피막이 빠르게 파괴되는 것을 확인할 수 있었으며, 염화물 첨가량 대비 0.6M의 LiNO2를 첨가한 경우 부식진행속도가 크게 저하하는 것을 확인할 수 있었다. 또한 염화물 첨가량 대비 1.2M의 LiNO2를 첨가한 경우 부동태 피 막이 부식가속시간이 지나도 파괴되지 않고 성능이 유지되는 것을 확인할 수 있었다.
        10.
        2017.01 KCI 등재 서비스 종료(열람 제한)
        Visual inspection has generally been applied to examine the coating deterioration. However, it was difficult to evaluate an anti-corrosion performance of paint film. In this study, thus, to quantitatively evaluate an anti-corrosion performance of paint film under various corrosion enviornent, change in the impedance paint coating was evauated using EIS (Electrochemical Impedance Spectroscopy).
        11.
        2016.04 서비스 종료(열람 제한)
        In this study, Corrosion behavior in mortar was observed by the passage of time by using EIS method. As a result of EIS experiment, equivalent circuit and changes of Impedance parameter could be observed. In addition, it was confirmed that impedance of rebar in mortar and corrosion rate according to the amount of NaCl were different.
        12.
        2016.04 서비스 종료(열람 제한)
        In this study, degradation due to the durability of the coating to reduce the check for to determine the deterioration of the durability coating was in parallel to outdoor exposure test and the salt spray test on the marine environment. weatherability paint coating was electrochemical measured using EIS (Electrochemical Impedance Spectroscopy) to evaluate durability. The purpose of the study was to compare the reduced durability of the paint coating.