• 제목/요약/키워드: Micro-leakage

검색결과 153건 처리시간 0.071초

오일시일의 동적거동에 관한 실험적 연구 (Experimental Study on the Dynamic Behaviour of Oil Seals)

  • 김청균;심우전
    • Tribology and Lubricants
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    • 제11권3호
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    • pp.54-58
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    • 1995
  • This paper deals with an experimental study on the dynamic behaviour of rubber oil seals when the interferences between the shaft and the seal lip as well as the dynamic eccentricities are present. The micro-separation of the sealing gap was observed with the aid of an image processing apparatus. The temperature of the seal lip edge, friction torque and the dynamic sealing gap profile are experimentally investigated for the initial interference and the shaft eccentricity. The data was simultaneously measured under the operation conditions. Experimental results show that, as the shaft speed is increased, the leakage of sealed fluids is increasing for a certain range of shaft speeds. The test data indicates that the shaft eccentricity clearly produces the gap separation between the shaft and the seal lip which is unable to follow the radial displacement of shaft as the shaft speed increases.

가로등 전용 누전 개폐기의 차단효과에 대한 고찰 (Characteristics of Street Lamp Controller with Earth Leakage Contactor)

  • 이성재;신재식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.283-283
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    • 2010
  • Smart street light controller is a product with advance micro controller base for energy saving in conventional street lighting systems. Intelligent Street light controller are specially developed for automation and energy saving in conventional street light systems and lighting systems. It is so designed that it operates on sunrise & sun set timings according to longitude of particular location with facilitate to set month wise civil twilight timings to cope up with all seasons. Dimming (Power down) mode selection switch on/off at fixed times with relay or contactor. Night dimming, staggering and intelligent control reduces burn hours and increases the lifetime of lamps with about 30% and low annual operating cost type base are among the most inexpensive wireless technologies available. Low initial costs As PLC wireless, there is no need to establish cable connection.

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MEMS 무선 기울기 센서를 이용한 노출 배관 응력 추정 (Stress estimation of exposed gas pipeline using MEMS wireless tilt sensor)

  • 김택근;강인구;신동훈;정태용;남진현;임시형
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2009년도 하계학술발표대회 논문집
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    • pp.404-408
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    • 2009
  • Gas pipelines in bridges, roads and subway construction sections can undergo abrupt stress and vibration changes. To protect human life from any gas leakage accidents induced by the abrupt stress and vibration, the gas pipeline system needs to be continuously monitored. The estimation method of pipeline stress using MEMS wireless tilt sensor has been developed and its validity has been evaluated using a lab test bench.

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유비쿼터스 기반의 주택 자동화용 디지털 분전반 개발 (Development of the Ubiquitous-based Intelligent Digital Switchgear Panel for Home Automation)

  • 고윤석;김호용;윤석열
    • 전기학회논문지
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    • 제57권5호
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    • pp.741-747
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    • 2008
  • This paper proposes a new concept of IDSP(Intelligent Digital Switchgear Panel) which can solve the problem of the safety, the reliability and the convenience to correspond to the requirement of the general electric customer or electric power company under the ubiquitous-based home automation environments. By analyzing their requirement functions, a 32-bit micro processor is adopted as main controller to support the designed functions efficiently. The DSP-based single phase power management device is utilized to collect the electric power information and the ethernet convertor to communicate through internet among the IDSPs and the remote computer system. In the proposed IDSP, the several functions are implemented such as the earth leakage level display and waveform transmission, the electric fee display, the voltage management, the load management and the load control function. Finally, the prototype of the IDSP is made experimently based on the designed results, and then the effectiveness is verified by testing its basic functions.

과도응답 해석에 의한 전자레인지 도어 프레임의 비틀림 변형 평가 (Evaluation of Twisting Deformation of the Door Frame of a Microwave Oven by Transient Response Analysis)

  • 구진영;이부윤
    • 대한기계학회논문집A
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    • 제29권9호
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    • pp.1282-1288
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    • 2005
  • This research has been motivated by the need to minimize possible leakage of microwave when one opens the door during operation of the microwave oven. An explicit finite element program is used to analyze the transient response the door of the oven under door-opening condition. Operation of the micro switch which plays an important role to hun off the power is simulated on the basis of the response of the latch. Using the results of the analysis, twisting deformation of the door frame is defined and evaluated.

Effects of Cavity Configuration on Bond Strength and Microleakage of Composite Restoration.

  • Choi, S.M.;Choi, K.K.;Park, S.J.
    • 대한치과보존학회:학술대회논문집
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    • 대한치과보존학회 2001년도 추계학술대회(제116회) 및 13회 Workshop 제3회 한ㆍ일 치과보존학회 공동학술대회 초록집
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    • pp.584.1-584
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    • 2001
  • The purpose of this study was to evaluate the effects of various cavity configuration on bond strength and micro leakage of composite restoration. The specimens were prepared as followed; For control group(C=1), bovine teeth were wet-ground to expose flat dentin surface and in experimental groups, cylindrical cavities, same all2mm deep and 6mm in diameter(C=2.3), 4mm(C=3.0), and 3mm(C=3.7) were prepared.(omitted)

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The comparison of microleakage on intracoronal restoration after non-vital bleaching

  • Jung, Jae-Eun;Lee, Hee-Joo;Hur, Bock
    • 대한치과보존학회:학술대회논문집
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    • 대한치과보존학회 2001년도 추계학술대회(제116회) 및 13회 Workshop 제3회 한ㆍ일 치과보존학회 공동학술대회 초록집
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    • pp.584.2-584
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    • 2001
  • The purpose of the present study were to evaluate microleakage of a fourth generation dentin-bonding agent following a walking bleaching treatment, to determine the effect of temporary postbleaching dressing with calcium hydroxide on microleakage and to investigate the effect of delayed intracoronal restoration on micro leakage. Forty extracted non-carious incisors were selected and conventional root canal treatment was performed. The teeth were randomly divided into 4 groups of 10 specimens each.(omitted)

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High resolution 5" full color field emission displays with new aging technique

  • Kim, J.M.;Hong, J.P.;Park, N.S.;Ryu, Y.S.;Jung, J.E.;Hong S.S.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 1998년도 제14회 학술발표회 논문개요집
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    • pp.23-23
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    • 1998
  • High resolution field emission dispplay(FED) devices of 5 inch diagonal in size are fully developped for the applications of near-future flat ppanel dispplays. Under the unique gate-switching drive scheme electron trajectory pprofiles are simulated and tested by considering leakage effects of each ppixel. Uniquely-pprinted sppacer with high asppect ratio are fabricated on real ITO glass for high vacuum ppackaging. In addition new gas aging scheme of stabilizing field emitting array are extensively investigated during the sealing and exhausting pprocess in order to pprevent oxidation effects on the micro tipp. Finally fulll color images of 64 gray scale will be demonstrated.

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표면조직 가공한 유압부품면에서의 윤활특성 (Lubrication Characteristics of Surface Textured Hydraulic Machine Components)

  • 이준오;박태조
    • 드라이브 ㆍ 컨트롤
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    • 제9권4호
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    • pp.26-31
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    • 2012
  • Friction reduction between sliding hydraulic machine components is required to improve efficiency and reliability of hydraulic machineries. It is recently reported that surface texturing on sliding bearing surfaces can reduce the friction force highly. In this paper, numerical analysis is carried out to investigate the effect of dimple numbers and inlet boundary pressures on the lubrication characteristics of a parallel sliding bearing using a commercial computational fluid dynamics (CFD) code, FLUENT. The results show that the pressure distribution, load capacity, dimensionless friction force and leakage with dimple number and their locations, and inlet pressures. The overall lubrication characteristics are highly affected by dimple numbers and boundary pressure. The numerical method adopted and results can be used in design of efficient hydraulic machine components.

배전용 폴리머애자의 현장열화 특성평가 (Characterization of Field-Aged Polymer Insulators for Distribution Power Systems)

  • 이병성;김찬영;한재홍
    • 한국전기전자재료학회논문지
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    • 제13권10호
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    • pp.847-858
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    • 2000
  • The aging characteristics of 2 kinds of 3 years field-aged distribution polymer insulators which were dismounted from 5 regions have been investigated by electrical test and material characterization. Although the tan $\delta$of specimens prepared from weathershed was increased with surface aging, the tan $\delta$and leakage current of real products had no difference between virgin and dismounted ones. Due to the aging, all dismounted polymer insulators had micro-cracks on the surface of weathershed and only the products of manufacturer B showed the reduction of OIT(oxidation induction time). But, there were no differences between virgin and dismounted products in contact angle and chemical structure. Therefore, it can be considered that the aging is only limited on the surface of dismounted polymer insulators and that NMR technique are very useful to evaluate the aging of polymer materials.

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