• 제목/요약/키워드: interface energy

검색결과 1,778건 처리시간 0.028초

산소 플라즈마 처리에 의한 반도전-절연 실리콘 고무의 접착 특성 (Adhesion Characteristics of Semiconductive and Insulating Silicone Rubber by Oxygen Plasma Treatment)

  • 이기택;허창수
    • 한국전기전자재료학회논문지
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    • 제19권2호
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    • pp.153-157
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    • 2006
  • In this work, the effects of plasma treatment on surface properties of semiconductive silicone rubber were investigated in terms of X-ray photoelectron spectroscopy (XPS) and contact angles, The adhesion characteristics of semiconductive-insulating interface layer of silicone rubber were studied by measuring the T-peel strengths, The results of the chemical analysis showed that C-H bonds were broken due to plasma discharge and Silica-like bonds(SiOx, x=3${\~}$4) increased, It is thought that semiconductive silicone rubber surfaces treated with plasma discharge led to an increase in oxygen-containing functional groups, resulting in improving the degree of adhesion of the semiconductive-insulating interface layer of silicone rubber. However, the oxygen plama for 20 minute produces a damaged oxidized semiconductive silicone rubber layer, which acts as a weak layer producing a decrease in T-peel strength, These results are probably due to the modifications of surface functional groups or polar component of surface free energy of the semiconductive silicone rubber.

Fabrication of interface-controlled Josephson junctions using Sr$_2$AlTaO$_6$ insulating layers

  • Kim, Jun-Ho;Choi, Chi-Hong;Sung, Gun-Yong
    • 한국초전도학회:학술대회논문집
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    • 한국초전도학회 2000년도 High Temperature Superconductivity Vol.X
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    • pp.165-168
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    • 2000
  • We fabricated ramp-edge Josephson junctions with barriers formed by interface treatments instead of epitaxially grown barrier layers. A low-dielectric Sr$_2$AlTaO$_6$(SAT) layer was used as an ion-milling mask as well as an insulating layer for the ramp-edge junctions. An ion-milled YBa$_2$Cu$_3$O$_{7-x}$ (YBCO)-edge surface was not exposed to solvent through all fabrication procedures. The barriers were produced by structural modification at the edge of the YBCO base electrode using high energy ion-beam treatment prior to deposition of the YBCO counter electrode. We investigated the effects of high energy ion-beam treatment, annealing, and counter electrode deposition temperature on the characteristics of the interface-controlled Josephson junctions. The junction parameters such as T$_c$, I$_c$c, R$_n$ were measured and discussed in relation to the barrier layer depending on the process parameters.

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유한요소 시뮬레이션을 통한 저온 분사 코팅의 계면 접합에 대한 연구 (Finite Element Simulation of Interface Bonding in Kinetic Sprayed Coatings)

  • 배규열;강기철;윤상훈;이창희
    • Journal of Welding and Joining
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    • 제26권6호
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    • pp.74-80
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    • 2008
  • A finite element modeling approach has been described for the simulation and analysis of the micron-scaled solid particle impact behavior in kinetic spraying process, using an explicit code (ABAQUS 6.7-2). High-strain-rate plastic deformation and interface bonding features of the copper, nickel, aluminum, and titanium were investigated via FEM in conjunction with the Johnson-Cook plasticity model. Different aspects of adiabatic shear instabilities of the materials were characterized as a concept of thermal boost-up zone (TBZ), and also discussed based upon energy balance concept with respect to relative recovery energy (RRE) for the purpose of optimizing the bonding process.

Vibration-based damage monitoring of harbor caisson structure with damaged foundation-structure interface

  • Lee, So-Young;Nguyen, Khac-Duy;Huynh, Thanh-Canh;Kim, Jeong-Tae;Yi, Jin-Hak;Han, Sang-Hun
    • Smart Structures and Systems
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    • 제10권6호
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    • pp.517-546
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    • 2012
  • In this paper, vibration-based methods to monitor damage in foundation-structure interface of harbor caisson structure are presented. The following approaches are implemented to achieve the objective. Firstly, vibration-based damage monitoring methods utilizing a variety of vibration features are selected for harbor caisson structure. Autoregressive (AR) model for time-series analysis and power spectral density (PSD) for frequency-domain analysis are selected to detect the change in the caisson structure. Also, the changes in modal parameters such as natural frequency and mode shape are examined for damage monitoring in the structure. Secondly, the feasibility of damage monitoring methods is experimentally examined on an un-submerged lab-scaled mono-caisson. Finally, numerical analysis of un-submerged mono-caisson, submerged mono-caisson and un-submerged interlocked multiple-caissons are carried out to examine the effect of boundary-dependent parameters on the damage monitoring of harbor caisson structures.

경량화용 CFRP 단일 모자형 부재와 CFRP 이중 모자형 부재의 계면수 변화에 따른 정적압궤특성 (The Static Collapse Characteristics of CFRP Single and Double Hat Shaped Section Members according to the Interface Number for Lightweight)

  • 황우채;차천석;양인영
    • 한국안전학회지
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    • 제27권6호
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    • pp.20-25
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    • 2012
  • Currently, the most important purpose in designing automobile is environment-friendly and safety performance aspect. CFRP(Carbon Fiber Reinforced Plastics) of the advanced composite materials as structure materials for vehicles, has a wide application in lightweight structural materials of air planes, ships and automobiles because of high strength and stiffness. In this study, experimental investigations are carried out for CFRP single and double hat shaped section member in order to study the effect of various stacking condition. They were cured by heating to the appropriate curing temperature($130^{\circ}C$) by means of a heater at the vacuum bag of the autoclave. The stacking conditions were selected to investigate the effect of the interface numbers. The CFRP single and double hat shaped section members which manufactured from unidirectional prepreg sheets were made of 8ply. The static collapse tests performed and the collapse mode and energy absorption capability were analyzed according to interface number.

원자층 증착법을 이용한 열전 소재 연구 동향 (Recent progress on Performance Improvements of Thermoelectric Materials using Atomic Layer Deposition)

  • 이승혁;박태주;김성근
    • 한국분말재료학회지
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    • 제29권1호
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    • pp.56-62
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    • 2022
  • Atomic layer deposition (ALD) is a promising technology for the uniform deposition of thin films. ALD is based on a self-limiting mechanism, which can effectively deposit thin films on the surfaces of powders of various sizes. Numerous studies are underway to improve the performance of thermoelectric materials by forming core-shell structures in which various materials are deposited on the powder surface using ALD. Thermoelectric materials are especially relevant as clean energy storage materials due to their ability to interconvert between thermal and electrical energy by the Seebeck and Peltier effects. Herein, we introduce a surface and interface modification strategy based on ALD to control the performance of thermoelectric materials. We also discuss the properties of the interface between various deposition materials and thermoelectric materials.

강-콘크리트 계면의 계면상수 결정 : 부착 및 비부착 슬립실험 (Determination of Steel-Concrete Interface Parameters : Bonded and Unbonded Slip Tests)

  • 이타;주영태;이용학
    • 콘크리트학회논문집
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    • 제21권6호
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    • pp.773-780
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    • 2009
  • 강-콘크리트 계면거동의 성질을 정의하는 계면변수를 파악하고, 구성모델의 성격을 정의하는 구성변수의 물리적 특성 파악과 값의 크기를 결정하기 위해 강-콘크리트 계면에 대한 거동실험을 수행하였다. 구성변수는 포괄적인 적용을 목적으로 부착계면 뿐만 아니라 비부착계면의 거동까지 포함하기 위해 최근에 Mohr-Coulomb 파괴규준에 근거하여 제안된 구성모델을 기준하여 결정하였으며, 구속압을 받는 계면의 취성으로부터 연성까지의 파괴거동 성질을 고려하기 위해 낮은 구속압 및 중간크기의 구속압을 포함하는 네 종류의 구속압을 고려하였다. 실험 결과에 대한 분석을 통해 최대평균전단응력과 잔류응력 및 모드 II 파괴에너지 방출률과 구속압 간의 관계는 각 경우가 선형적 관계에 있음을 확인하였다. 이 논문에서 얻어진 실험 결과에 근거하여 이어지는 후속 논문에서는 해석적 방법에 의한 계면상수 값의 결정과 결정된 계면상수 값을 이용한 계면유한요소해석을 수행하여 계면상수 값의 적절성을 검증하였다.

Advances in Li-ion Batteries

  • Lee, Se-Hee
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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    • pp.51.2-51.2
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    • 2010
  • Efficient and durable electrical energy storage is one of the major factors limiting the wide-spread adoption of renewable energy. Since lithium-ion batteries (LIBs) were first commercialized in the early 1990s, LIBs have emerged as an important energy storage device for portable electronics. LIBs are very desirable because of their high energy storage per volume and per mass. However, LIBs with high energy and power as well as higher stability are needed for their use in a variety of energy storage applications such as MEMS devices, PDA, plug-in hybrids, all-electric vehicles and large scale utility systems. In this talk, I will discuss present energy perspective, especially energy storage and its role in renewable energy. After that I will discuss the recent advances in nanostructured materials and interface engineering that have led to the achievement of improved Li-ion batteries. Finally I will talk aboutcritical issues that need to be addressed to obtain further improvements in Li-ion batteries.

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MOLECULAR ORIENTATIONS OF INTRAMOLECULAR CHARGE TRANSFER AROMATIC MOLECULES IN THE ORGANIZED MEDIA

  • Shin, Dong Myung
    • Journal of Photoscience
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    • 제1권1호
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    • pp.53-59
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    • 1994
  • Molecular orientation and polarity of solubilization site of dipolar azobenzenes solubilized in micellar solutions are discussed. The polarity of solubilization was estimated by using Taft $\pi$$^*$ scale with linear solvation energy relationship, $\Delta$E=$\Delta$E$_0$ + S($\pi$$^*$ + d$\delta$)+a$\alpha$ + b$\beta$. Hydrogen bonding effects were taken into account for the estimation of micropolarity. The polarity that azobenzenes experienced in the miceliar solutions was close to water which represented that the azobenzenes were mostly solubilized at the interface. For the orientations of azobenzenes were concerned, the nitro group of NPNOH faced the interface and the hydroxy group of NPNO$^-$ located at the interfacial area.

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비정질 칼코게나이드 반도체 박막 경계면의 전기적 특성 (Electrical characteristics of the this film interface of amorphous chalcogenide semiconductor)

  • 박창엽
    • 전기의세계
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    • 제29권2호
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    • pp.111-117
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    • 1980
  • Contacts formed by vacuum evaporation of As-Te-Si-Ge chalcogenide glass onto Al metal (99.9999%) are studied by measuring paralle capacitance C(V), Cp(w), resistance R(V), Rp(w), and I-V characteristics. The fact that contact metal alloying produced high-resistance region is confirmed from the measurements of parallel capacitance and resistance. From the I-V characteristics in the pre-switcing region, it is found that electronic conduction and sitching occurs in the vicinity of metal-amorphous semiconductor interface. From the experimental obsevations, it is concuded that the current flow in the thin film is space-charge limited current (SCLC) due to the tunneling of electrons through the energy barriers.

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