• Title/Summary/Keyword: Interface resistance

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Effects of Slip for Interface on Behavior and Capacity in Hybrid Structure (합성구조체의 경계면 슬립이 거동과 성능에 미치는 영향)

  • 정연주;정광회;김병석
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.385-390
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    • 2001
  • This paper presents a nonlinear analysis technique with slip, the effects of slip modulus and composite action by shear connector on behavior and capacity in composite structure of sandwich system. As a results of this study, it proved that the slip modulus, in case of shear behavior, seldom influence load-resistance capacity such as yield and ultimate load, but in case of flexural behavior, it appropriately influence load-resistance capacity because of stress redistribution by slip. In case of flexural behavior, analysis result for perfect-composite results in over-estimation and perfect-slip results in under-estimation on behavior and capacity. Therefore, it is desirable to model steel-concrete interface with partial-composite. The effects of slip on behavior and capacity are less in case of positive composite than loosely composite, and it proved that composite action by shear connector improve the load-resistance capacity of this system.

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Shear strength of connections between open and closed steel-concrete composite sandwich structures

  • Kim, Woo-Bum;Choi, Byong Jeong
    • Steel and Composite Structures
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    • v.11 no.2
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    • pp.169-181
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    • 2011
  • The behavior of connections between open sandwich slabs and double steel skin composite walls in steel plate-concrete(SC) structure is investigated by a series of experimental programs to identify the roles of components in the transfer of forces. Such connections are supposed to transfer shear by the action of friction on the interface between the steel surface and the concrete surface, as well as the shear resistance of the bottom steel plate attached to the wall. Experimental observation showed that shear transfer in slabs subjected to shear in short spans is explained by direct force transfer via diagonal struts and indirect force transfer via truss actions. Shear resistance at the interface is enhanced by the shear capacity of the shear plate as well as friction caused by the compressive force along the wall plate. Shear friction resistance along the wall plate was deduced from experimental observation. Finally, the appropriate design strength of the connection is proposed for a practical design purpose.

Mitigating Antibiotic Resistance at the Livestock-Environment Interface: A Review

  • Ma, Zhengxin;Lee, Shinyoung;Jeong, K. Casey
    • Journal of Microbiology and Biotechnology
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    • v.29 no.11
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    • pp.1683-1692
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    • 2019
  • The rise of antimicrobial resistance (AR) is a major threat to global health. The food animal industry contributes to the increasing occurrence of AR. Multiple factors can affect the occurrence and dissemination of AR in the animal industry, including antibiotic use and farm management. Many studies have focused on how the use of antibiotics in food-producing animals has led to the development of AR. However, a few effective mitigating strategies for AR have been developed in food-producing animals, especially those exposed to the environment. The aim of this review is to summarize potential strategies applicable for mitigating AR at the environment-livestock interface.

Reappearance of the Electrical Poor Contact in Connectors by Fretting Wear (프렛팅 마모에 의한 커넥터 단자의 접촉불량 재현)

  • Kim, Seong-Woo;Jung, Won-Wook;Wei, Shin-Hwan;Kim, Hyung-Min;Park, Sung-Bae;Lee, Dong-Hun
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1361-1366
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    • 2008
  • Failure mechanism of the poor contact is analyzed on the basis of used connectors and this poor contact of connectors is reappeared by the new forced fretting wear method. As the result of failure analysis and reappearance, fretting wear and corrosion of the contact interface causes the contact resistance degradation and the poor contact of connectors. The amount of degradation depends on the fretting stroke. Changes in contact resistance of static contacts are likely to be small and gradual, while motions of contact interface may result in larger and discontinuous changes in resistance and voltage. This voltage drop by fretting motions is large enough to cause the distortion of sensor signal and mis-working of electric components.

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Controlled Plasma Treatment for Edge Contacts of Graphene (그래핀의 엣지 접합 (Edge Contact)을 위한 플라즈마 처리 연구)

  • Yue, Dewu;Ra, Chang-Ho;Liu, Xiaochi;Daeyeong, Daeyeong;Yu, Won-Jong
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2014.11a
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    • pp.293-293
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    • 2014
  • The applicability of graphene has been demonstrated in the electronic fields. But, high performance of graphene is limited by the contact resistance (Rc) at the metal-graphene interface. Recently, Rc was found to be improved by forming edge-contacted graphene via theoretical simulation. Based on the differences between the surface and edge contacts at the M-G interface, we demonstrate "edge-contacted" graphene through the use of a controlled plasma processing technique that generates the edge structure of the bond and significantly reduces the contact resistance. The contact resistance attained by using pre-plasma processing was of $270{\Omega}{\cdot}{\mu}m$. Mechanisms of pre-plasma process leading to low Rc was revealed by SEM and Raman spectroscopy. In the end, controlled pre-plasma processing enabled to fabricate CVD-graphene field effect transistors with an enhanced adhesion and improved carrier mobility.

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Conducting and interface characterization of carbonate-type organic electrolytes containing EMImBF4 as an additive against activated carbon electrode

  • Kim, Mingyeong;Kim, Kyungmin;Kim, Seok
    • Carbon letters
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    • v.16 no.1
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    • pp.51-56
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    • 2015
  • Carbonate-type organic electrolytes were prepared using propylene carbonate (PC) and dimethyl carbonate (DMC) as a solvent, quaternary ammonium salts, and by adding different contents of 1-ethyl-3-methyl imidazolium tetrafluoroborate ($EMImBF_4$). Cyclic voltammetry and linear sweep voltammetry were performed to analyze conducting behaviors. The surface characterizations were analyzed by scanning electron microscopy method and X-ray photoelectron spectroscopy. From the experimental results, increasing the $EMImBF_4$ content increased the ionic conductivity and reduced bulk resistance and interfacial resistance. In particular, after adding 15 vol% $EMImBF_4$ in 0.2 M $SBPBF_4$ PC/DMC electrolyte, the organic electrolyte showed superior capacitance and interfacial resistance. However, when $EMImBF_4$ content exceeded 15 vol%, the capacitance was saturated and the voltage range decreased.

Study on Heat Resistance Anaerobic Adhesive Which Expands When Post Cured

  • Zhai, Haichao;Li, Yinbai;Lin, Xinsong
    • Journal of Adhesion and Interface
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    • v.3 no.1
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    • pp.9-12
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    • 2002
  • In this paper, N,N-m-phenyenedimaleimide (m-PDM), Polyamide Resin (PI) and Metallic dimethacrylate etc. influencing the heat resistance of anaerobic adhesive has been studied, an anaerobic adhesive composition capable of post-cure expansion and $230^{\circ}C$ temperature resistance comprising a multifunctional methacrylate and m-PDM capable of effectuating expansion upon post-cure has been developed. A homogeneous mixture of a monomer and m-PDM are subjected to a first cure heat stage (Room Temperature) wherein a rigid partially-cured plastic is formed and a post-cure heat stage ($150^{\circ}C$) to effectuate permanent expansion of cured adhesive composition.

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Investigation on Contact Resistance of Amorphous Indium Gallium Zinc Oxide Thin Film Transistors with Various Electrodes by Transmission Line Method

  • Lee, Sang Yeol
    • Transactions on Electrical and Electronic Materials
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    • v.16 no.3
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    • pp.139-141
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    • 2015
  • Contact resistance of interface between the channel layers and various S/D electrodes was investigated by transmission line method. Different electrodes such as Ti/Au, a-IZO, and multilayer of a-IGZO/Ag/a-IGZO were compared in terms of contact resistance, using the transmission line model. The a-IGZO TFTs with a-IGZO/Ag/a-IGZO of S/D electrodes showed good performance and low contact resistance due to the homo-junction with channel layer.

A study on innovation resistance of voice user interface - With emphasis on mobile intelligent personal assistance service - (음성 사용자 인터페이스에 대한 사용자 혁신저항 요인 연구 - 모바일 지능형 개인비서 서비스 중심으로 -)

  • He, jie;Zhao, zi-han
    • Proceedings of the Korea Contents Association Conference
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    • 2017.05a
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    • pp.467-468
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    • 2017
  • 본 연구에서는 모바일 지능형 개인비서 서비스의 음성 사용자 인터페이스(Voice User Interface, VUI) 사용에 있어서 혁신저항요인을 연구한다.

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