• Title/Summary/Keyword: surfaces characteristics

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Wear Characteristics of Dental Prosthesis (치과보철물 재료의 마멸특성)

  • Choi, Won-Sik;Kim, Won-Ku
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.7 no.3
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    • pp.110-114
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    • 2008
  • In this study, to examine the friction coefficient and wear amount of dental prosthesis, pin-on-disk type wear test were at room temperature. Vickers hardness and fracture toughness measurement of dental materials were preformed. Microscopic observations on worn surfaces of specimens were conducted by SEM. The friction coefficient of dental material was investigated according to weight and slinging velocity. dental material have investigated composed to nature teeth.

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The discharge characteristics and ICP-AES analysis of insulators by surface deterioration (애자 표면열화에 의한 방전특성과 ICP-AES 분석)

  • Shong, Kil-Mok;Kim, Young-Seok;Jung, Jin-Soo
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.1408_1409
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    • 2009
  • It's described the discharge characteristics and ICP-AES analysis of insulators by surface deterioration in this paper. For the assessment of insulators, there are applied the conductivity of dusts, contact angle measurement of the insulator surfaces and the ingredient analysis in each area. Through the analysis of pollutants attached to insulators inside the tunnel, the cleaning cycle is discussed. As the results, it would be expected to the electrical safety.

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Dynamic Surface In-plane Switching Property using the Ferroelectric Liquid Crystal on the surface

  • Choi, Sang-Ho;Choi, Su-Seok;Shin, Hyun-Ho;Chung, In-Jae
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.868-871
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    • 2006
  • In-plane switching characteristics of PI rubbed ITO sandwich cell with low molecule FLC (ferroelectric liquid crystal) surface was investigated. FLC on the surface is governed by the applying frequency and surface condition. By controlling the Ps (spontaneous polarization) direction of dual FLC surfaces, switching characteristics are improved without change of cell structure.

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Aerodynamic Analysis of Smart UAV with CFD (CFD를 이용한 스마트 문인기의 공력특성 분석)

  • Kim C. W.;Chung J. D.;Lee J. Y.
    • 한국전산유체공학회:학술대회논문집
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    • 2004.10a
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    • pp.105-109
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    • 2004
  • CFD simulation for Smart-UAV(TR-E2Sl) is performed to analyze its aerodynamic characteristics. Base geometry and several cases, decided by control surfaces being deflected, are simulated. To obtain the better lift characteristics, the elevator should be deflected between 10o and 20o with the incidence angle of the wing 1o.

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Fretting Wear Characteristics of Nuclear Fuel Rod Material (핵연료봉재의 프레팅 마멸 특성)

  • 김태형;조광희;김석삼
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1996.04b
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    • pp.25-29
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    • 1996
  • The fretting wear characteristics for Zircaloy-4 tube used as fuel rod in the nuclear power plant have been investigated. The fretting wear tester was designed and manufactured for this experiment. This study was focused on main factors of fretting wear, cycle, slip amplitude and normal load. The worn surfaces were observed by SEM.

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Wear Characteristics of Plastic Pinion Against Steel Gear (플라스틱기어의 마멸특성에 관한 고찰)

  • 김충현;김영민;안효석;정태형
    • Tribology and Lubricants
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    • v.16 no.5
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    • pp.324-331
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    • 2000
  • Wear characteristics of Plastic and Nylon pinions against steel gear were studied to gain a better understanding of their tribological behaviors. Wear tests were conducted with power circulating gear test rig under dry contact conditions. Specific wear rates were measured as a function of applied load and the number of revolution. The worn teeth surfaces were examined with a profile projector and a camera. Nylon pinion showed lower specific wear rates than acetal pinion, but suffered teeth breakage under high load per unit tooth width. The dominant wear mechanisms found were adhesion and abrasion.

Heat Transfer Characteristics of Radiation-Mixed Convection in a Three-Dimensional PCB Channel (3차원 PCB 채널내에서의 복사-혼합대류 열전달 특성)

  • Lee, J.H.;Park, K.W.;Pak, H.Y.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.8 no.4
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    • pp.561-575
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    • 1996
  • The interaction of turbulent mixed convection and surface radiation in a three-dimensional channel with the heated blocks is analyzed numerically. Two blocks are maintained at high temperature and the other bottom and horizontal walls are insulated. S-4 method is employed to calculate the effect of the radiative heat transfer. The low Reynolds number k-$\varepsilon$ model proposed by Launder and Sharma is used to estimate the turbulent influence on the heat transfer enhancement. From above modeling, the effects of various channel specifications on the flow and heat transfer characteristics are investigated. The variables used for the present study are Reynolds number, block spacing, the channel height spacing for block and the emissivity. Average Nusselt numbers along the block surfaces are correlated and presented in terms of Reynolds number, emissivity and dimensionless geometric parameters. For the range of conditions in this study, average Nusselt numbers along the block surfaces are strongly influenced by the Reynolds numbers and channel height spacing for block but weakly influenced by the block spacing and the emissivity of the adiabatic walls.

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