• Title/Summary/Keyword: adhesion

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A study of adhesion characteristics progress for electric car (전동차의 점착특성 향상에 관한 연구)

  • Kim, Gil-Dong;Han, Young-Jae;Park, Hyun-Jun;Lee, Sa-Young
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.1436-1438
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    • 2000
  • It is one of the most effective methods for improving the performance of electric railway vehicles to make better the wheel-rail adhesion characteristics. To study adhesion characteristic is to develop the equivalent reduction machine to experiment on the adhesion system. The experiment system makes it possible to change the wheel-rail adhesion force with various adhesion parameters, and therewith to test the adhesion control system with the reduction machine in a laboratory. In this paper, for improving adhesion performance shows actually control methods.

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Modern State of Models for Fundamental Adhesion - A Review Extended Abstract

  • Possart, Wulff
    • Journal of Adhesion and Interface
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    • v.3 no.1
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    • pp.43-51
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    • 2002
  • Advanced adhesive technologies and demanding applications of adhesive joints can no longer be developed successfully by the traditional "trial and error" approach. Appropriate technical solutions require reference to a reliable basis of well-established scientific knowledge about the elementary mechanisms of adhesion (i.e. the 'fundamental adhesion') as they are responsible for the capability of the compound w transmit mechanical force between the adhesive and the substrate surface (i.e. the 'practical adhesion'). Adhesion mechanisms also influence the formation of polymer structure in the adhesive and the resulting macromolecular dynamics in the interphase that is formed in the adhesive near to the substrate. These manifold molecular factors rule the macroscopic behaviour of an adhesive bond line in terms of mechanical and other physical properties as well as in terms of durability. This paper reviews the level of refinement that understanding of fundamental adhesion has achieved up to now.

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A Study on Deducting Adhesion Characteristic of Urban Train (전동차 점착특성 추정에 관한 연구)

  • Kim, Gil-Dong;Lee, Han-Min;Oh, Seh-Chan;Lee, Chang-Mu;Park, Sung-Hyuk
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.659-664
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    • 2006
  • It is one of the most effective method for improving the performance of electric railway vehicles to make better the wheel-rail adhesion characteristics. To study adhesion characteristic is to develop the equivalent reduction machine to experiment on the adhesion system. The experiment system makes it possible to change the wheel-rail adhesion force with various adhesion parameters, and therewith to test the adhesion control system with the reduction machine in a laboratory. In this paper for improving adhesion performance show actually control methods.

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Influence of Deposition Conditions on the Adhesion of Sputter-deposited MoS$_2$-Ti Films

  • Kim, Sun-Kyu;Yongliang Li
    • Journal of the Korean institute of surface engineering
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    • v.37 no.1
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    • pp.1-4
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    • 2004
  • MoS$_2$-Ti films were deposited on SKD-11 tool steel substrate by a D.C. magnetron sputtering system. The influence of deposition parameters on the adhesion of the films was investigated by the scratch test. Crosssection morphology was evaluated using FE-SEM. The plasma etching played an important role on the adhesion of the films. The appropriate etching conditions roughened the surface, resulting In the improved adhesion of the film. The adhesion of the film increased with the interlayer thickness up to 110 nm and then decreased slightly with further increasing of interlayer thickness. The adhesion was highest at a bias voltage of -50 V. Further increase of the bias voltage decreased the film adhesion.

Nanotribological characteristics of silicon surfaces modified by IBAD (IBAD로 표면개질된 실리콘표면의 나노 트라이볼로지적 특성)

  • 윤의성;박지현;양승호;공호성;장경영
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2001.06a
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    • pp.127-134
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    • 2001
  • Nano adhesion and friction between a Sj$_3$N$_4$ AFM tip and thin silver films were 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 ranges of normal load. Thin silver films deposited by IBAD (ion beam assisted deposition) on Si-wafer (100) and Si-wafer of different surface roughness were used. Results showed that nano adhesion and friction decreased as the surface roughness increased. When the Si surfaces were coated by pure silver, the adhesion and friction decreased. But the adhesion and friction were not affected by the thickness of IBAD silver coating. As the normal force increased, the adhesion forces of bare Si-wafer and IBAD silver coating film remained constant, but the friction forces increased linearly. Test results suggested that the friction was mainly governed by the adhesion as long as the normal load was low.

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Irregular Failures at Metal/polymer Interfaces

  • Lee, Ho-Young
    • Journal of the Korean institute of surface engineering
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    • v.36 no.4
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    • pp.347-355
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    • 2003
  • Roughening of metal surfaces frequently enhances the adhesion strength of metals to polymers by mechanical interlocking. When a failure occurs at a roughened metal/polymer interface, the failure prone to be cohesive. In a previous work, an adhesion study on a roughened metal (oxidized copper-based leadframe)/polymer (Epoxy Molding Compound, EMC) interface was carried out, and the correlation between adhesion strength and failure path was investigated. In the present work, an attempt to interpret the failure path was made under the assumption that microvoids are formed in the EMC as well as near the roots of the CuO needles during compression-molding process. A simple adhesion model developed from the theory of fiber reinforcement of composite materials was introduced to explain the adhesion behavior of the oxidized copper-based leadframe/EMC interface and failure path. It is believed that this adhesion model can be used to explain the adhesion behavior of other similarly roughened metal/polymer interfaces.

Determination of Optimal Adhesion Conditions for FDM Type 3D Printer Using Machine Learning

  • Woo Young Lee;Jong-Hyeok Yu;Kug Weon Kim
    • Journal of Practical Engineering Education
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    • v.15 no.2
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    • pp.419-427
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    • 2023
  • In this study, optimal adhesion conditions to alleviate defects caused by heat shrinkage with FDM type 3D printers with machine learning are researched. Machine learning is one of the "statistical methods of extracting the law from data" and can be classified as supervised learning, unsupervised learning and reinforcement learning. Among them, a function model for adhesion between the bed and the output is presented using supervised learning specialized for optimization, which can be expected to reduce output defects with FDM type 3D printers by deriving conditions for optimum adhesion between the bed and the output. Machine learning codes prepared using Python generate a function model that predicts the effect of operating variables on adhesion using data obtained through adhesion testing. The adhesion prediction data and verification data have been shown to be very consistent, and the potential of this method is explained by conclusions.

Expression of Intercellular Adhesion Molecule-1 and E-Selectin in Gastric Cancer and Their Clinical Significance

  • Jung, Woo-Chul;Jang, You-Jin;Kim, Jong-Han;Park, Sung-Soo;Park, Seong-Heum;Kim, Seung-Joo;Mok, Young-Jae;Kim, Chong-Suk
    • Journal of Gastric Cancer
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    • v.12 no.3
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    • pp.140-148
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    • 2012
  • Purpose: Among cell adhesion molecules, serum levels of intercellular adhesion molecule-1 and E-selectin are known to be correlated with the metastatic potential of gastric cancer. In the present study, the authors investigated the expression of intercellular adhesion molecule-1 and E-selectin in gastric cancer tissues and cultured gastric cancer cells, and examined their clinical value in gastric cancer. Materials and Methods: The protein was extracted from gastric cancer tissues and cultured gastric cancer cells (MKN-28 and Kato-III) and the expression of intercellular adhesion molecule-1 and E-selectin was examined by western blotting. The clinical significance of intercellular adhesion molecule-1 and E-selectin was explored, using immunohistochemical staining of specimens from 157 gastric cancer patients. Results: In western blot analysis, the expressions of intercellular adhesion molecule-1 in gastric cancer tissues and cultured gastric cancer cells were increased, however, E-selectin in gastric cancer tissues and cells were not increased. Among 157 gastric cancer patients, 79 patients (50%) were intercellular adhesion molecule-1 positive and had larger tumor size, an increased depth of tumor invasion, lymph node metastasis and perineural invasion. The intercellular adhesion molecule-1 positive group showed a higher incidence of tumor recurrence (40.5%), and a poorer 3-year survival than the negative group (54.9 vs. 85.9%, respectively). Conclusions: Intercellular adhesion molecule-1 is overexpressed in gastric cancer tissues and cultured gastric cancer cells, whereas E-selectin is not overexpressed. Increased expression of intercellular adhesion molecule-1 in gastric cancer could be related to the aggressive nature of the tumor, and has a poor prognostic effect on gastric cancer.

Characteristics of the Adhesion Layer for the Flexible Organic Light Emitting Diodes (플렉시블 OLED 소자 제작을 위한 접합층 특성 연구)

  • Cheol-Hee Moon
    • Journal of Adhesion and Interface
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    • v.24 no.3
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    • pp.86-94
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    • 2023
  • To fabricate all-solution-processed flexible Organic Light-Emitting Diodes (OLEDs), we demonstrated a bonding technology using a polyethyleneimine (PEI) as an adhesion layer between the two substrates. As the adhesion layer requires not only a high adhesion strength, but also a high current density, we have tried to find out the optimum condition which meets the two requirements at the same time by changing experimental factors such as PEI concentration, thickness of the layer and by mixing some additives into the PEI. The adhesion strength and the electrical current density were investigated by tensile tests and electron only device (EOD) experiments, respectively. The results showed that at higher PEI concentration the adhesion strength showed higher value, but the electrical current through the PEI layer decreased rapidly due to the increased PEI layer thickness. We added Sorbitol and PolyEthyleneGlycohol (PEG) into the 0.1 wt% PEI solution to enhance the adhesion and electrical properties. With the addition of the 0.5 wt% PEG into the 0.1 wt% PEI solution, the device showed an electrical current density of 900 mA/cm2 and a good adhesion characteristic also. These data demonstrated the possibility of fabricating all-solution-processed OLEDs using two-substrate bonding technology with the PEI layer as an adhesion layer.

Nano Adhesion and Friction of $DDPO_4$ and $ODPO_4$ SAM Coatings ($DDPO_4$$ODPO_4$SAM 코팅의 나노 응착 및 마찰 특성 연구)

  • ;;;Andrei Ya Grigoriev
    • Tribology and Lubricants
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    • v.18 no.4
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    • pp.267-272
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    • 2002
  • Nano adhesion between SPM(scanning probe microscope) tips and DDPO$_4$(octadecylphosphoric acid ester.) and ODPO$_4$(octadecylphosphoric acid ester) 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 with the applied normal load. DDPO$_4$ and ODPO$_4$ SAM were formed on Ti and TiOx surfaces. Ti and TiOx were coated on the Si wafer by ion sputtering. Adhesion and friction of DDPO$_4$ and ODPO$_4$ SAM surfaces were compared with those of OTS(octadecyltrichlorosilane) SAM and DLC surfaces. DDPO$_4$ and ODPO$_4$ SAM converted the Ti and TiOx surfaces to be hydrophobic. When the surface was hydrophobic, the adhesion and friction forces were found lower than those of bare surfaces. Work of adhesion was also discussed to explain how the surface was converted into hydrophobic Results also showed that tribological characteristics of DDPO$_4$ and ODPO$_4$ SAM had good properties in the adhesion, friction, wetting angle and work of adhesion. DDPO$_4$ and ODPO$_4$ SAM could be one of the candidates for the bio-MEMS elements.