• Title/Summary/Keyword: Actual Peeling Area

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A New Perspective on the Advanced Microblade Cutting Method for Reliable Adhesion Measurement of Composite Electrodes

  • Song, Jihun;Shin, Dong Ok;Byun, Seoungwoo;Roh, Youngjoon;Bak, Cheol;Song, Juhye;Choi, Jaecheol;Lee, Hongkyung;Kwon, Tae-Soon;Lee, Young-Gi;Ryou, Myung-Hyun;Lee, Yong Min
    • Journal of Electrochemical Science and Technology
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    • v.13 no.2
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    • pp.227-236
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    • 2022
  • The microblade cutting method, so-called SAICAS, is widely used to quantify the adhesion of battery composite electrodes at different depths. However, as the electrode thickness or loading increases, the reliability of adhesion values measured by the conventional method is being called into question more frequently. Thus, herein, a few underestimated parameters, such as friction, deformation energy, side-area effect, and actual peeing area, are carefully revisited with ultrathick composite electrodes of 135 ㎛ (6 mAh cm-2). Among them, the existence of side areas and the change in actual peeling area are found to have a significant influence on measured horizontal forces. Thus, especially for ultrahigh electrodes, we can devise a new SAICAS measurement standard: 1) the side-area should be precut and 2) the same actual peeling area must be secured for obtaining reliable adhesion at different depths. This guideline will practically help design more robust composite electrodes for high-energy-density batteries.

Concrete Crack Detection Inside Finishing Materials Using Lock-in Thermography (위상 잠금 열화상 기법을 이용한 콘크리트 마감재 내부 균열 검출)

  • Myung-Hun Lee;Ukyong Woo;Hajin Choi;Jong-Chan Kim
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.6
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    • pp.30-38
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    • 2023
  • As the number of old buildings subject to safety inspection increases, the burden on designated institutions and management entities that are responsible for safety management is increasing. Accordingly, when selecting buildings subject to safety inspection, appropriate safety inspection standards and appropriate technology are essential. The current safety inspection standards for old buildings give low scores when it is difficult to confirm damage such as cracks in structural members due to finishing materials. This causes the evaluation results to be underestimated regardless of the actual safety status of the structure, resulting in an increase in the number of aging buildings subject to safety inspection. Accordingly, this study proposed a thermal imaging technique, a non-destructive and non-contact inspection, to detect cracks inside finishing materials. A concrete specimen was produced to observe cracks inside the finishing material using a thermal imaging camera, and thermal image data was measured by exciting a heat source on the concrete surface and cracked area. As a result of the measurement, it was confirmed that it was possible to observe cracks inside the finishing material with a width of 0.3mm, 0.5mm, and 0.7mm, but it was difficult to determine the cracks due to uneven temperature distribution due to surface peeling and peeling of the wallpaper. Accordingly, as a result of performing data analysis by deriving the amplitude and phase difference of the thermal image data, clear crack measurement was possible for 0.5mm and 0.7mm cracks. Based on this study, we hope to increase the efficiency of field application and analysis through the development of technology using big data-based deep learning in the diagnosis of internal crack damage in finishing materials.