• Title/Summary/Keyword: Adhesion Characteristic

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Expression of Adhesion Molecule in Inflammatory Gingival Tissue (염증성 치은조직에서 Cell Adhesion Molecule의 발현에 관한 연구)

  • Park, Kyung-Geun;Kim, Eun-Chul;You, Hyung-Keun;Shin, Hyung-Shik
    • Journal of Periodontal and Implant Science
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    • v.26 no.3
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    • pp.655-668
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    • 1996
  • The change in vascular adhesion molecule expression and number of infiltrating leukocytes were investigated irnmunohistochemically in clinically healthy and inflammed gingiva. Monoclonal antibodies to ICAM-1, VCAM-1 and E-cadherin were used to identify positive vessels and leukocyte within gingival biopsies. 10 healthy gingiva and 30 inflammed gingiva was resected by clinical crown lengthening and modified Widman flap operation, respectively. Leukocyte entry into tissues at sites of inflammation is controlled by the interaction between adhesion molecule and endothelium. Because of rapid and severe destructive periodontal disease that is remarkable leukocyte adhesion deficiency, it is very important to unerdstand the mechanism of host defence against periodontal disease. The purpose of this investigation was the characterization of the presence and distribution of the adhesion molecule(ICAM-1, VCAM-1 and Evcadherin) in inflammatory gingival tissues compared to clinically healthy gingiva. The results were as followed; 1. ICAM-1 was distributed on basal layer, endothelium and mononuclear cells 10 healthy gingiva but inflammed gingiva was observed stronger stain than healthy gingiva. 2. Rare expression was observed in both group but few positive VCAM-1 cells were investigated in inflammatory gingival tissues 3. E-cadherin was expressed in only epithelium and reduced expression was observed in inflammatory gingival tissues. ICAM-1, VCAM-1 showed more expression in inflammatory tissues compared to healthy gingiva. Conversely, E-cadherin revealed a opposite result. These finding demonstrate a characteristic distribution and degree of adhesion molecule in healthy and inflammatory gingival tissues. But it is suggested that more detail study be progressive associated with leukocyte adhesion molecule to determine characterization of periodontal disease.

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A study on the improvement of coating film characteristic in arc spraying by using the inert gas (아크용사시 불활성가스에 의한 피막밀착강도 향상에 관한 연구)

  • 김영식;여욱종
    • Journal of Welding and Joining
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    • v.5 no.2
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    • pp.17-26
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    • 1987
  • In this study, the experiments were carried out for the purpose of establishment of the arc sparing method which reducing oxides or oxide film by using the inert gas as the carrier gas of atomizing particles. Main results obtained are as follows; 1. Oxides and oxide film which lower the adhesion strength are largely reduced by using the inert gas as the carrier gas of atomizing particles, and adhesion strength of coating film are improved. 2. The coating film characteristics appear to be no difference between the inert gas arc spraying in air environment and that in argon gas environment. 3. Inert gas arc spraying using argon as the carrie gas has higher reduction rate of composition element in coating film than compressed air spraying does.

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Adhesion Estimation and Modeling on Traction Characteristic of Vehicle (차량 견인특성모델링 및 점착력 추정)

  • Byun, Yeun-Sub;Kim, Min-Soo;Mok, Jei-Kyun;Kim, Young-Chol
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1765_1766
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    • 2009
  • In this paper, we propose the mathematical model for the vehicle system and the observer for adhesion force. To model the dynamic properties of vehicle system, we have considered two fundamental parts. The first part is the motion equations for vehicle based on Newton's second law. The second part is the torque dynamics of the traction motor. These parts are affected by outer conditions such as adhesive coefficient, running resistance and gradient resistance. The each parts are presented by the numerical formula. From two equations, we get the observer on adhesion force. Simulation results show that the proposed observer have the good performance compared with the normal observer.

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Development of the Measurement System for Evaluating Mechanical Properties of Nano-diamond Coated Film (나노 다이아몬드 코팅박막의 기계적 특성 평가를 위한 계측시스템의 개발)

  • Kweon, Hyun Kyu;Lee, So Jin;Kweon, Yong Min
    • Journal of the Semiconductor & Display Technology
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    • v.18 no.1
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    • pp.25-31
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    • 2019
  • In this study, a new adhesion evaluating equipment and data processing methods were developed to overcome some limitations of existing evaluating equipment. Nano-diamond coated tool is a specimen of experiment. When applying frictional force and shear force on the specimen by a rotating polishing pad, delamination occurs at a moment. During each experiment, the vibration, load, and torque is obtained by accelerometer, loadcell and torque s+ kpensor. Frictional force and coefficient of friction are obtained by calculating torque and load. Based on FFT transformation, acceleration is processed and analyzed. As a result, the moment of delamination and the load at that time can be detected by the new developed equipment and measurement system. Finally, we call this load as an Adhesion force.

Adhesion Characteristics of Polymer Material Treated by Atmospheric Pressure Plasma (상압 플라즈마 표면처리에 의한 고분자 재질의 접착특성 변화)

  • Seo, Seung-Ho;Chang, Sung-Hwan;Yoo, Yeoung-Een;Chung, Jae-Dong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.5
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    • pp.445-450
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    • 2011
  • We studied the adhesion characteristics of polymer films (PC, PET, EVA) treated by atmospheric pressure plasma. The process parameters were the frequency, gas flow, and treatment time; we studied the effects of these parameters on the adhesion characteristics of the polymer materials. We used de-ionized water and diiodomethane as the polar and nonpolar solvents, respectively, for measuring the contact angles, and subsequently calculated the surface free energy of each polymer film. The adhesion characteristics were studied by carrying out a $180^{\circ}$ peel-off test. The polymer films treated with plasma developed a hydrophilic surface, which led to increased surface free energy and improved adhesion properties. From the results for contact angle, surface free energy, and adhesion strength, we obtained the optimal plasma-treatment conditions.

The Flexible Characteristic of Reversible and Robust Nanohair Fastener

  • Park, Seung-Ho;Yoon, Young-Seok;Lee, Dong-Woo;Lee, Dong-Ik;You, Kyoung-Hwan;Pang, Chang-Hyun;Suh, Kahp-Yang
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.432-432
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    • 2011
  • Dry adhesion caused by Nanoscale contact comes up to important scientific issue. Herein, we introduce bendable nanohairy locking fastener system with high shear strength and mechanically flexible backing. The polymeric patches like velcro are composed of an array of straight nanohairs with 100 nm diameter and $1{\mu}m$ height. To fabricate high aspect vertical nanohairs, we used UV molding method with appropriately flexible and rigid polyurethane acrylate material on PET substrate. Two identical nanohairy patches are easily merged and locked each other induced by van der Waals force. Because nanohairs can be arrayed with high density ${\sim}4{\times}10^8/cm^2$, we can obtain high shear adhesion force on flat surface (~22 N/$cm^2$). Furthermore, we can obtian nanohairy locking system with maximum shear adhesion ~48 N/$cm^2$ of curved surface due to flexibility of PET substrate. We confirm the tendency that shear adhesion force increases, as radius of curvature increases.

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Study on Early Adhesive Characteristic of Chip Seals Using a Surface Energy Approach (표면 에너지 원리를 이용한 칩실 포장의 초기 점착력 특성 연구)

  • Im, Jeong Hyuk
    • International Journal of Highway Engineering
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    • v.17 no.6
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    • pp.47-54
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    • 2015
  • PURPOSES : The objective of this study is to evaluate the early adhesive characteristic of asphalt emulsions, including polymer-modified emulsions, for chip seals using the surface energy concept, the bitumen bond strength (BBS) test, and the Vialit test. METHODS : Two general methods, the BBS test and Vialit test, were applied to investigate the bond strength and the aggregate loss, respectively. A new theory, the surface free energy (SFE) theory, was used to evaluate the adhesive characteristic between the emulsion and the aggregate. Based on the theory, the contact angles were measured, and then the surface energy components were calculated. Using those components, the work of adhesion (Wa) was calculated for each emulsion. To ensure reliable results, all the tests were performed under the same conditions, i.e., at $25^{\circ}C$ for 240 minutes of curing time. For the materials, three emulsions (CRS-2, CRS-2L, and CRS-2P) and one aggregate type (granite) were employed. RESULTS AND CONCLUSIONS : Under the same conditions, the modified emulsions showed better adhesive characteristics and curing behaviors than the unmodified emulsions. In addition, there was no significant difference between the various modified emulsions. One of the important findings is that the analysis by Wa presents more sensitive results than other methods. The results of the Wa showed that the CRS-2P emulsion has the best adhesive characteristics. Consequently, the use of modified emulsions for chip seals could prevent aggregate loss and allow open traffic earlier.

A Study on Formative and Aesthetic Characteristics of the Costume of Dance Sports (댄스 스포츠 의상의 조형성과 미적 특성에 관한 연구)

  • Kim, Mi-Young
    • The Research Journal of the Costume Culture
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    • v.14 no.6
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    • pp.1042-1055
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    • 2006
  • The purpose of this study is to consider the formative characteristics of dance sports from such points of view as shapes, colors, material and decorations, and to examine artistic characteristics that are expressed through those elements. As a result, this study shows five artistic characteristics as follows; First, rhythmic characteristic is expressed with repeat of lines that is formed by pleats, shirring or gather, with duplication of ruffle's wave, with gradation of colors, with Moire-effect that is generated with overlap of see-through material, with glossy material that reflects lights to a great extent, with fringe. Second, bodily characteristic emphasizes the beauty of human bodies through direct or indirect body exposure by way of cut-and-open, see-throughness or close adhesion. Third, decorative characteristic is shown with beads, fringe, ruffle, embroidery, shirring, binding, or feather. Fourth, the beauty of female body is manifested to express eroticism, which is culminated by body exposure, body consciousness, use of illuminating or see-through material or colorful trimming. Finally, elegant characteristic is revealed through feminity, sophistication, and harmony that are expressed with black and white colors, see-through material, or bead trimmings.

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A Study on the Effective Stress of RC Beams in Applying the Adhesion Reinforced and the External Post-Tensioning Method (RC보의 부착보강공법과 외부강선보강공법의 유효응력에 관한 연구)

  • Park, Yong-Gul;Choi, Jung-Youl;Choi, Jun-Hyeok
    • Journal of the Korean Society for Railway
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    • v.10 no.2 s.39
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    • pp.186-194
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    • 2007
  • This study was performed to compare the load-carrying capacities of the reinforced concrete structure between the carbon fiber adhesion reinforcement method and the external post-tensioning method and further estimate the effective stress of the reinforced material by analyzing the experimental reinforcing effect of each method and the behavior resulting from each method. As a result, it was found out that the effective stress of the carbon fiber reinforcement according to the carbon fiber adhesion reinforcement method had an unexpected value, and also, bearing of the stress was found to be far from sharing thereof. That is to say, while the carbon fiber was bearing the whole stress to some limits, it got to be momentarily ruptured as soon as it went beyond such limits. On the other hand, the external post-tensioning method has the advantage of inducing an initial effective stress by introducing a strain, and thus, it was found that behavior or bearing of the stress was also found to be a solid behavior of the steel wire. This method was also found to be more efficient and excellent than the carbon fiber adhesion reinforcement method in the reinforcing effect or securing the effective stress. Accordingly, we were to discuss the effective stress as comparatively examined, focusing on deriving of the more enhanced reinforcing effect on the basis of the experiment to which the field characteristic is added.

Soil Stress Analysis Using Discrete Element Method for Plate-Sinkage Tests (DEM 모델을 이용한 평판재하시험의 토양 수직응력 해석)

  • Jang, Gichan;Lee, Soojin;Lee, Kyu-Jin
    • Korean Journal of Computational Design and Engineering
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    • v.20 no.3
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    • pp.230-237
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    • 2015
  • Soil deformation on the off-load ground is significantly affected by soil conditions, such as soil type, water content, and etc. Thus, the soil characteristics should be estimated for predicting vehicle movements on the off-load conditions. The plate-sinkage test, a widely-used experimental test for predicting the wheel-soil interaction, provides the soil characteristic parameters from the relationship between soil stress and plate sinkage. In this study, soil stress under the plate-sinkage situation is calculated by the DEM (Discrete Element Method) model. We developed a virtual soil bin with DEM to obtain the vertical reaction forces under the plate pressing the soil surface. Also parametric studies to investigate effects of DEM model parameters, such as, particle density, Young's modulus, dynamic friction, rolling friction, and adhesion, on the characteristic soil parameters were performed.