• Title/Summary/Keyword: JKR model

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Nanoscale Vibro-Contact Analysis of AFM Tip on Polymer Surface (폴리머 표면측정을 위한 AFM 팁의 나노스케일 접촉-진동 해석)

  • Lee, Soo-Il
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.2 s.245
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    • pp.135-140
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    • 2006
  • In tapping mode atomic force microscopy (TM-AFM), the vibro-contact response of a resonating tip is used to measure the nanoscale topology and other properties of a sample surface. However, the nonlinear tipsurface interactions can affect the tip response and destabilize the tapping mode control. Especially it is difficult to obtain a good scanned image of high adhesion surfaces such as polymers and biomolecules using conventional tapping mode control. In this study, theoretical and experimental investigations are made on the nonlinear dynamics and control of TM-AFM. Also we report the surface adhesion is an additional important parameter to determine the control stability of TM-AFM. In addition, we proved that it was adequate to use Johnson-Kendall-Roberts (JKR) contact model to obtain a reasonable tapping response in AFM for the soft and high adhesion samples.

An Experimental Study on the Nano-adhesion of Octadecyltrichlorosilane SAM on the Si Surface (OTS SAM의 미소 응착 특성에 관한 실험적 연구)

  • 윤의성;박지현;양승호;한흥구;공호성
    • Tribology and Lubricants
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    • v.17 no.4
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    • pp.276-282
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    • 2001
  • Nano adhesion between SPM (scanning probe microscope) tips and 075 (octadecyltrichlorosilane) SAM (self-assembled monolayer) was experimentally studied. Tests were performed to measure the nano adhesion and friction in both AFM(atomic force microscope) and LFM(lateral force microscope) modes in various conditions of relative humidity. OTS SAM was formed on Si-wafer (100) surfaces, and Si$_3$N$_4$ tips of different radius of curvature were used. When the surface was hydrophobic, the adhesion and friction forces were found lower than those of bare Si-wafer. Results also showed that micro-adhesion force increased as the relative humidity and the tip radius of curvature increased. The main parameter for affecting the micro-adhesion was found absorbed humidity on the contact surface. These results were discussed with the JKR model and a capillary force caused by absorbed water.

Prediction of PTO Power Requirements according to Surface energy during Rotary Tillage using DEM-MBD Coupling Model (이산요소법-다물체동역학 연성해석 모델을 활용한 로타리 경운작업 시 표면 에너지에 따른 PTO 소요동력 예측)

  • Bo Min Bae;Dae Wi Jung;Jang Hyeon An;Se O Choi;Sang Hyeon Lee;Si Won Sung;Yeon Soo Kim;Yong Joo Kim
    • Journal of Drive and Control
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    • v.21 no.2
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    • pp.44-52
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    • 2024
  • In this study, we predicted PTO power requirements based on torque predicted by the discrete element method and the multi-body dynamics coupling method. Six different scenarios were simulated to predict PTO power requirements in different soil conditions. The first scenario was a tillage operation on cohesionless soil, and the field was modeled using the Hertz-Mindlin contact model. In the second through sixth scenarios, tillage operations were performed on viscous soils, and the field was represented by the Hertz-Mindlin + JKR model for cohesion. To check the influence of surface energy, a parameter to reproduce cohesion, on the power requirement, a simple regression analysis was performed. The significance and appropriateness of the regression model were checked and found to be acceptable. The study findings are expected to be used in design optimization studies of agricultural machinery by predicting power requirements using the discrete element method and the multi-body dynamics coupling method and analyzing the effect of soil cohesion on the power requirement.

A Study on the Art Management and Cultural Activities in China from the K-Wave Case

  • Jia Ning LI;Su SHUAI;Zhang FAN
    • Journal of Koreanology Reviews
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    • v.2 no.1
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    • pp.27-31
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    • 2023
  • The purpose of this paper is to study the relationship between Art management and Cultural activities in China from the K-wave case. Research design, data, and methodology: This study used the method of the cases study survey, with the K-wave case in as the survey objects, 3 valid survey sample case were collected in this paper. Results: The two dimensions of art management and cultural activities differently influences from the K-wave, and the influence of availability on customer satisfaction is not significant. Conclusion: The results of this study will provide useful reference for the Art management and Cultural activities in China from the K-wave case. And improve the development of art management and cultural activities in China by improving the K-wave of service quality. Art management can shape urban commercial space in a beneficial way, create a good consumption atmosphere, and enhance the attractiveness and competitiveness of the city. The introduction of art elements into urban commercial space can create a strong cultural atmosphere, so that the city presents a smart look. Art management has a positive impact on K-Wave production and operation activities, which can promote the shaping of art commercial space, the promotion of urban cultural atmosphere.