• Title/Summary/Keyword: contact effect

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Preparation of Organic Peltier using Fullerene/Polyaniline (Fullerene과 Polyaniline을 이용한 유기 Peltier소자의 개발)

  • Lee, Chae-Jung;Kim, Joo-Yong
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.343-345
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    • 2007
  • Temperature difference between two plates occurs when a current is passed though two semi-conductors that are connected each other at two junctions. The current drives a transfer of heat from one junction to the other. In this study, the thermoelectric module based on th "Peltier effect" was made by combing fullerene and polyaniline. Continuous temperature measurements on both surfaces were performed at room temperature($25.4^{\circ}C$) by an infrared non-contact thermometer. The results showed that cool ing effect of $2.2^{\circ}C$ was attained by 30 seconds, after which the effect was continuously vanished mainly due to electro decomposition.

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A Study on the Surface Roughness Variation of Spur Gear Teeth as a function of the Surface Treatment (표면처리에 따른 평기어 치의 표면거칠기 변화에 관한 연구)

  • 유장열;이성철;권오관;정태형
    • Tribology and Lubricants
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    • v.7 no.2
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    • pp.67-74
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    • 1991
  • The contact characteristics of gear tooth surface were studied by using the gear test rig of power circulation type. The effect of surface treatment conditions and revolutions on the tooth surface roughness parameters, and the relations between the lubrication conditions and tooth surface conditions, in spur gear sets wear considered. The result show that heat treatment of gear have an important effect upon fatigue strength and tooth surface conditions, and surface asperities undergo a circulating process of creation and destruction because of the influnce of plastic deformation. And surface roughness conditions at the tooth tips accompany a great deal of variation in running-in stage. According to the lubrication analysis and the study the tooth surface have a greater effect on surface demage than lubrication conditions, in mixed-lubrication condition.

Surface Treatment Effect on Electrical Characteristics of Ink-Jet Printed Pentacene OTFTs Employing Suspended Source/Drain Electrode

  • Park, Young-Hwan;Kim, Yong-Hoon;Kang, Jung-Won;Oh, Myung-Hwan;Han, Jeong-In
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1312-1314
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    • 2007
  • The effect of gate insulator surface treatment on electrical characteristics of bottom contact (BC) and suspended source/drain (SSD) organic thinfilm transistors (OTFTs) was studied. Triisopropylsilylethynyl pentacene was used as an active material and was printed by ink-jet printing method. In case of the BC OTFTs, threshold voltage was shifted from positive to near zero, and the fieldeffect mobility was increased when the gate insulator surface was treated with hexamethyldisilazane. However, in case of SSD OTFT, threshold voltage shift was not observed and the field-effect mobility was decreased.

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Temperature Dependent Mdbility Characteristics of InSb Thin Film (홀센서 InSb 박막 이동도의 온도의존성)

  • 이우선;조준호;최권우;김남오;김형곤;김상용;서용진
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.582-585
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    • 2001
  • InSb temperature dependent hall effect of multilayerd structures were investigated. According to variation of magnetic field measured hall coefficient, Hall mobility, carrier density and hall voltage. For the measurement of electrical properties of hall device, evaperated InSb thin film fabricated with series and parallel multilayers. We found that the XRD analysis of InSb thin film showed good properties at 200$^{\circ}C$, 60 minutes. Resistance of ohmic contact increased linearly due to increasing current. Some of device fabrication technique and analysis of Hall effect were discussed.

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A Possible Sunlight Effect on the Aging Characteristics of Silicone Rubber used for Outdoor Insulation (태양광 모의 열화에 의한 옥외용 실리콘 고무의 열화특성에 관한 연구)

  • Lim, C.R.;Lee, J.H.;Kim, J.T.;Koo, J.Y.;Park, W.K.
    • Proceedings of the KIEE Conference
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    • 1998.07d
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    • pp.1276-1278
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    • 1998
  • In this paper, aging characteristics of silicone rubber used for outdoor insulation have been investigated with regards to sunlight effect. For this purpose, silicone rubbers were aged under the artificial sunlight by use of xenon arc lamp(1500W) and various tests were performed such as tracking, breakdown, contact angle, stress, strain. And then, in order to elucidate the changes of material, analysis have been followed as follows; FT-IR, SEM and EDS. Regarding the effect of the sunlight, it was obs that the surface of test samples are severely da with decreased hydrophobicity, tracking resistan breakdown strength.

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A Study on Glass-Infiltrated Alumina and Spinel Composite I. Effect of Microstructure and Glass Content on Contant Damage and Strength (유리침윤 알루미나 및 스핀넬 복합체에 관한 연구 I. 미세구조 및 유리함량이 접촉손상 및 강동에 미치는 영향)

  • 정연길;최성철
    • Journal of the Korean Ceramic Society
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    • v.35 no.7
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    • pp.671-678
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    • 1998
  • Hertzian indentation tests with sphere indenters were used to study the mechanical properties of glass-in-filtrated alumina and spinel composites and evaluated the effect of preform microstructure and evaluated the effect of preform microstructure and glass con-tents on contanct damage and strength. The spinel composite showed more brittle behavior than the alumina composite which is verified from indentation stress-strain curve cone cracks and quasi-plastic deformation developed at subsurface. Failure originated from either cone cracks(brittle mode) or deformation zone(quasi-plastic mode) above critical load for cracking(Pc) and yield ({{{{ {P }_{Y } }}) with the brittle mode more dominant in the spinels and the quasi-plastic mode more dominant in the aluminas. Even though brittle mode was dominant in the spinel composites the strength degradation from accumulation of damage above these critical loads was conspicuously small suggesting that the glass-infiltrated composites should be highly damage tolerant to the blunt contacts.

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Electrical Properties of CuPc Field-effect Transistor (CuPc를 이용한 전계효과트랜지스터의 전기적 특성)

  • Lee, Ho-Shik;Park, Yong-Pil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.410-411
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    • 2008
  • Organic field-effect transistors (OFETs) are of interest for use in widely area electronic applications. We fabricated a copper phthalocyanine (CuPc) based field-effect transistor with different metal electrode. The CuPc FET device was made a top-contact type and the substrate temperature was room temperature. The source and drain electrodes were used an Au and Al materials. The CuPc thickness was 40nm, and the channel length was $50{\mu}m$, channel width was 3mm. We observed a typical current-voltage (I-V) characteristics in CuPc FET with different electrode materials.

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Antimicrobial Hydrogel Contact Lens Containing Alginate

  • Lee, Hyun-Mee;Kim, Jong-Ki;Cho, Tae-Sub
    • Bulletin of the Korean Chemical Society
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    • v.32 no.12
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    • pp.4239-4243
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    • 2011
  • Biocompatible hydrogels from 2-hydroxyethyl methacrylate (HEMA) monomer containing various amount of alginate in the presence and absence of hydrophilic methacrylic acid (MAA) were synthesized in order for biomedical application. The antimicrobial effect and interaction with proteins for hydrogels were investigated in this study. MAA was introduced because it was expected to increase the amount of water content in the polymer which is an important factor for biocompatibility, and alginate was expected to enhance the antimicrobial activity. The antimicrobial effect against S. aureus and E. coli increased for all hydrogels as the amount of alginate and MAA contained. Presence of MAA further enhances the antimicrobial effect. Amount of adsorption of bovine serum albumin (BSA) increased with increasing concentration of alginate whether MAA was present or not. Contrarily, the amount of lysozyme was not affected with increasing alginate concentration in the absence of MAA, while it decreased in the presence of MAA.

Temperature Effect on Pavement Types of Bimodal Tram Dedicated Lane (바이모달 트램 전용선로 포장 형태에 따른 온도의 영향)

  • Park, Young-Kon;Yoon, Hee-Taek;Mok, Jai-Kyun;Kim, Ryang-Gyun
    • Proceedings of the KSR Conference
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    • 2010.06a
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    • pp.2107-2112
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    • 2010
  • To analyze the effect of temperature on pavement types of dedicated lane, we have performed a temperature monitoring for pavements which were constructed in test track for Bimodal Tram. These pavements classified into four types; natural and artificial lawn, concrete and asphalt. Dedicated lane composed of natural and artificial lawn has a complex structure with concrete slab in contact surface of tires, and with 1m natural or artificial lawn in the middle part of lane. From monitoring results for pavements, dedicated lane with natural lawn shows lower temperature value compared with other dedicated lanes, and it is expected to decrease the heat island effect of conventional road if constructed.

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Sheet Metal Forming Analysis with Planar Anisotropic Materials using a Modified Membrane Element considering Bending Effect (굽힘이 고려된 개량박막요소를 이용한 평면이방 박판금속 성형해석)

  • Choi, Tae-Hoon;Huh, Hoon
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1997.03a
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    • pp.183-187
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    • 1997
  • A membrane element is regarded as more preferable rather than other elements in the sense of its computing efficiency and the merit with respect to contact treatment. However, it cannot consider the bending effect during the deformation. Moreover, due to the characteristics of rolling process, sheet metal has anisotropy with respect to the direction in the plane. To take the bending effect into account, a modified membrane element was introduced and improved to consider planar anisotropic characteristics with the aid of Hill's quadratic criterion.

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