• Title/Summary/Keyword: kind of adhesive

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Microstructure of the biological attachment devices in the ladybug Harmonia axyridis (Coleoptera: Coccinellidae)

  • Moon, Myung-Jin;Kim, Hyo-Jeong;Kim, Hoon;Park, Jong-Gu
    • Animal cells and systems
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    • v.16 no.6
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    • pp.479-487
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    • 2012
  • Biological attachment device is optimized in insect legs for attachment onto the variety of natural substrate. We have studied the microstructural characteristics of the tarsal appendages in the ladybug Harmonia axyridis using scanning electron microscopy to reveal the attachment system of their legs. The attachment devices are composed of claws and adhesive pads. The claws are connected with pretarsal segment, and their apical diverged hooks are developed to hold rough substrates. In contrast, the adhesive pads have an adhesive function onto smooth surface. The pads are interspersed at the ventral part of each tarsomere, and are composed of two kinds of hairy setae. The discoid tip seta (DtS) has a spoon-shaped endplate usually with a rounded concave structure, whereas the pointed tip seta (PtS) has a pointed tip, usually with a hooked endplate. While the PtS is broadly localized concentrically on the marginal area of both the proximal and distal pads, the DtS can be seen at the central areas of each adhesive pad except for the hind legs. Our findings demonstrate the presence of the direction-dependence pattern of the fibrillar system as well as a functional modification of the tenent setae to achieve proper contact with almost any kind of substrates.

The Stress Analysis of Dissimilar Materials in Brazed Interface by BEM (이종재 브레이징 접합계면의 응력해석)

  • 오환섭;김시현;김성재
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.769-772
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    • 1997
  • In this study, By employing two dimensional(2-D) Boundary Element Method(BEM) stress analysis was carried to investigate stress distributions on the brazing joint of a Hardmetal and a HSS. Two model was proposed to analyze stress singularity in brazed interface. The stress results from the BEM were considered influence of the kind of materials , thickness of filled metal and length of vertical brazing adhesive. From those obtained results , the peak point of stress was founded in the lower part of two interface was made by brazing. As the thickness and length changed, the maximum stress tended to change in the peak point.

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Stress intensity factors in adhesive bonded orthotropic structures (두직교이방성 평판을 접착한 구조물의 응력화대변수)

  • ;;Hong, C. S.
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.5 no.3
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    • pp.217-222
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    • 1981
  • The stress analysis of two-orthotropic layer, adhesively bonded structures is considered. An orthotropic plate has a through-crack of finite length and is adhesively bounded by a sound orthotropic plate. The problem is resuced to a pair of Fredholm integral equations ofthe second kind. Using a numerical integration scheme to evaluate the intgrals, The integral equations are reduced to a system of algebraic equations. By solving these equations some numerical results for stress intensity factors are presented for various crack lengths.

The effect of solvent evaporation of dentin adhesive on bonding efficacy (상아질 접착제의 용매 증발이 접착 효율에 미치는 영향)

  • Cho, Min-Woo;Kim, Ji-Yeon;Kim, Duck-Su;Choi, Kyoung-Kyu
    • Restorative Dentistry and Endodontics
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    • v.35 no.5
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    • pp.321-334
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    • 2010
  • Objectives: The purpose of this study is to evaluate bonding efficacy by means of measuring the effect of remained solvent on Degree of conversion(DC) and ${\mu}TBS$ and FE-SEM examination. Materials and Methods: Two 2-step total etching adhesives and two single-step self etching adhesives were used in this study. First, volume weight loss of 4 dentin adhesives were measured using weighting machine in process of time in normal conditions and calculate degree of evaporation (DE). Reaction/reference intensity ratio were measured using micro-Raman spectroscopy and calculate DC according to DE. Then 2 experimental groups were prepared according to air-drying methods (under, over) and control group was prepared to manufacturer's instruction. Total 12 groups were evaluated by means of micro tensile bond strength and FE-SEM examination. Results: Degree of evaporation (DE) was increased as time elapsed but different features were observed according to the kind of solvents. Acetone based adhesive showed higher DE than ethanol and butanol based adhesive. Degree of conversion (DC) was increased according to DE except for $S^3$ bond. In ${\mu}TBS$ evaluation, bond strength was increased by additional air-drying. Large gaps and droplets were observed in acetone based adhesives by FE-SEM pictures. Conclusions: Additional air-drying is recommended for single-step self etching adhesive but careful consideration is required for 2-step total etching adhesive because of oxygen inhibition layer. Evaporation method is carefully chose and applied according to the solvent type.

접착형 박막 측온게이지식 열류센서의 개발에 관한 연구

  • 한응교;박두원;최규철;노병옥;이명호
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1991.11a
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    • pp.80-86
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    • 1991
  • In this study an the development of the heat flux sensor with thermocouple, the heat-treated adhesive type film nickel gauge(Ni-Gauge) for measuring temperature was used. and this Ni-Gauge is not only comparable for platinum gauge(Pt-Gauge) in linearity, but also economically cheap. And from this viewpoint. numerical analysis is essential to investigate charateristics of sensor, since this analysis is capable of simulating precise boudary condition and practical conditions and so on. By the way. there are many types of heat flux sensor. of which adhesive type flux sensor is common, in the study this type of heat flux sensor was chogen. and analysis of the sensor is considered as a kind of open cavity figure. performed by SIMPLER algorithm. As a result. through temperature distributial of the sensor by numerical analysis in steady and unsteady state, the dracteristics of the acdhesive type heat flux sensor(lst heat flux sensor) acooodinge to heat flux, that is, outvoltage, sensitivity. and responsibilty could be evaluated. in addition, time of improved heat flux sensor(2nd heat flux sensor) could be predicted fran the reflectian of proper operating temperature(l50 $^{\circ}C$)of theNi-Gauge.

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The U.S. Courts' Attitudes towards the Validity of Consumer Arbitrations (소비자중재합의의 효력에 관한 미국 법원의 태도와 함의)

  • Kang, Yong-Chan;Park, Won-Hyung
    • Journal of Arbitration Studies
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    • v.21 no.1
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    • pp.73-86
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    • 2011
  • Today's arbitrations see themselves as the most effective scheme for dispute resolution in a variety of transactional context. While some kind of ADR system was already introduced in Korea as of 2007 with revision of the Consumer Basic Law, consumers' needs in dispute resolution remain unmet. Recently one consumer arbitration case divides the U.S. Supreme Court. Of course, the result of the case is expected to affect tens of millions of arbitration agreements in the States which has the most developed scheme in consumer arbitrations. While Arbitration clauses in adhesion contracts are not automatically held to be substantively unconscionable, Class action waivers are one of the most controversial issues in consumer arbitration. In this study, with the theoretical background of consumer arbitrations general, and contractual defenses against adhesive contracts, reviewed are U.S. federal courts' attitudes toward certain consumer arbitration agreements including the class arbitration waiver. Moreover, several issues in AT&T case are examined for practical implications for consumer dispute resolution. All of these are expected to initiate further research to find some guidelines for the proper status and operation of consumer arbitration here in Korea.

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Flexural behaviour of steel plate-masonry composite beams

  • Jing, Deng-Hu;Cao, Shuang-Yin;Shi, Lei
    • Steel and Composite Structures
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    • v.13 no.2
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    • pp.123-137
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    • 2012
  • Steel plate-masonry composite structure is a newly-developed type of structural technique applicable to existing masonry buildings by which the load-bearing walls can be removed for large spaces. This kind of structure has been used in practice for its several advantages, but experimental investigation on its elements is nearly unavailable in existing literature. This paper presents an experimental study on the flexural behaviour of four steel plate-masonry composite beams loaded by four-point bending. Test results indicate that failure of the tested beams always starts from the local buckling of steel plate, and that the tested beams can satisfy the requirement of service limit state. In addition, the assumption of plane section is still remained for steel plate prior to local buckling or steel yielding. By comparative analyses, it was also verified that the working performance of the beam is influenced by the cross-section of steel plate, which can be efficiently enhanced by epoxy adhesive rather than cement mortar or nothing at all. Besides, it was also found that the contribution of the encased masonry to the flexural capacity of the composite beam cannot be ignored when the beam is injected with epoxy adhesive.

Synthesis, Curing and Properties of Silicone-Epoxies

  • Huang, Wei;Yuan, Youxue;Yu, Yunzhao
    • Journal of Adhesion and Interface
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    • v.7 no.4
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    • pp.39-44
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    • 2006
  • A new kind of silicone-epoxy composite is reported in this research. The silicone-epoxy resin was synthesized by the hydrosilylation of tetramethycyclotetrasiloxane and 4-vinyl-1-cyclohexene 1,2-epoxy with a high reaction yield. It was found that the obtained silicone-epoxy resin shows a high reactive activity to the aluminum complex-silanol catalyst. The resin could be cured under the catalysis of $(Al(acac)_3/Ph_2Si(OH)_2$ at a concentration below 0.1 wt% to give a hard cured resin showing excellent optical clarity, UV resistance and thermal stability. It was also found that the Si-H groups facilitated the curing reaction and the silicone-epoxy resin bearing Si-H group could be cured effectively even if $Ph_2Si(OH)_2h$ was absent. Moreover, the UV resistance and thermal stability were improved significantly by the introduction of Si-H groups. This is possibly due to the reductive property of Si-H groups which can annihilate radical and peroxide effectively. This kind of silicone-containing epoxy composite might have very promising applications as optical resin, optical adhesive and encapsulation materials for electronic devices.

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Actual Condition of Remodeling in Apartment Unit - Grasp of Remodeling elements by Specialists' In-depth Interviews - (아파트 단위주거의 리모델링 실태 - 실무자 심층면접에 의한 리모델링 요소 현황 파악 -)

  • Choi, Yoon-Jung;Shim, Hyun-Suk;Jeong, Youn-Hong
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2007.05a
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    • pp.81-84
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    • 2007
  • The purpose of this study was to grasp actual condition of remodeling elements by specialists' in-depth interviews. The interview has been conducted to interior designer who have a wide experience of apartment remodeling. In-depth interview is a kind of qualitative method in which attention to reply of responses with open-access between interviewer and respondents. According to the results, remodeling elements were generally the renovation of balcony into the livingroom or children room, removal a doorsill, installation of storage furniture, change of lighting fixtures in the all rooms and change equipments of bathroom. Finishing materials were usual used normal wallpaper and normal or low emitting adhesive on ceiling and wall, tempered-flooring on floor, and ceramic tiles on bottom and wall of bath and entrance.

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Formation of Ti-0 Biomedical Film on Ti6A14V Alloy by DC Glow Plasma Oxidizing

  • Zheng, C.L.;Cui, F.Z.;Xu, Z.
    • Journal of Korean Vacuum Science & Technology
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    • v.6 no.1
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    • pp.16-21
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    • 2002
  • Ti-0 film is a kind of biocompatible surface materials. In this paper, a new method, glow discharge plasma oxidizing, has been used in synthesizing Ti-O gradient films on Ti6A14V substrates. The effects of ion bombardment and process parameters on the structures of titanium oxide layers have been investigated. The results demonstrate that DC glow plasma oxidizing is more efficient in preparation of dense, hard, and high adhesive Ti-O biomedical films on titanium and its alloys. Samples treated by this method show higher hardness values than by others. Especially, in the condition of hollow cathode discharge, the ion bombardment enhances ionization of oxygen, promotes the oxygen permeation and facilitates the formation of the oxide of low valence states of titanium.

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