• 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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    • 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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Measurement of Adhesion (접착력의 측정)

  • Kim, Sung-Ryong;Lee, Ho-Young
    • Journal of Adhesion and Interface
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    • v.4 no.3
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    • pp.21-32
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    • 2003
  • Various methods for adhesion measurement, which are related to previously published paper [J. of Soc. of Adhe. and Inter, 3,4 (2002)], are reviewed. At first, the prerequisite for the ideal adhesion strength measurement is considered, and three categories of methods for adhesion measurement, such as mechanical, non-mechanical methods and miscellaneous methods, are introduced.

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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.

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 adhesion strength of electroless plated deposits on Alumina substrate (Alumina substrate 상의 무전해 도금층의 밀착력에 관한 연구)

  • 조용균;안균영;박용수
    • Journal of the Korean institute of surface engineering
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    • v.24 no.4
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    • pp.187-195
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    • 1991
  • Adhesion strength of electroless-plated Ni, Ni-P and Cu deposites on alumina substrate has been studied. Grain boundary spaces produced on the substrate surface by etching treatment provided anchoring sites for enhancing the adhesion strength. Adhesion strengths of Ni-P and Ni deposit were higher than that of Cu deposit, because of higher initial nucleation rates than the latter. The electroless-plated Ni-P and Ni underlayer improved the adhesion strength of the Cu deposit. In could be attributed to the enhanced adhesion between the substrate and those underlayers as well as the satisfactory adhesion between Cu deposits and those underlayers. Heat treatment was also conducted in order to enhance the adhesion strength of Cu layer. The strength was enhanced by about 19% when the treatment was conducted at $150^{\circ}C$ for 2 hours. The enhancement was attributed to relief of internal stress and release of hydrogen.

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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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    • 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.

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.

Adhesion between Rubber Compound and Copper-Film-Coated Steel Plate Prepared by Vacuum Sputtering and Substitution Plating Methods (진공증착법과 치환도금법으로 제조한 구리박막 피복철판과 배합고무의 접착)

  • Moon, Kyung-Ho;Han, Min-Hyun;Seo, Gon
    • Journal of Adhesion and Interface
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    • v.4 no.3
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    • pp.1-8
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    • 2003
  • Adhesion between rubber compound and copper-film-coated steel plate (abbreviated hereafter as copper film plate) with different thicknesses of copper film was investigated. Two different methods were employed for the preparation of the copper film plates: a substitution plating of preelectroplated zinc with copper ion and a vacuum sputtering of copper on steel plate. Adhesion strength of the copper film plates with rubber compounds was largely dependent upon the thickness of copper film, regardless of their preparation methods. The copper film plates with thinner thickness than 75 nm showed high adhesion comparable to brass, while those with thicker copper film showed poor adhesion due to excessive growth of copper sulfide at adhesion interface.

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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.