• 제목/요약/키워드: stack effect

검색결과 325건 처리시간 0.03초

연료전지 분리판의 스프링백 저감에 관한 연구 (A Study on the Reduction of Springback for the Separator Plate of MCFC)

  • 김정현;이상욱
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2006년도 춘계학술대회 논문집
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    • pp.345-348
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    • 2006
  • The focus of this study is placed on the reduction of springback in the separator plate which is one of main components of the MCFC stack. Firstly, the current design (round punch and die) is accessed using FEM to find out how much it springs back after the forming operation. In this study, the two kinds of modified designs are proposed in order to reduce the amount of springback. With the linear punch in the first modified design the amount of springback rather increased. In the second modified design of die with holes, the amount of springback decreased drastically due to the effect of compression at the die corner.

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TIPS Anthracene Derivatives for Solution Process OTFT Materials : Large $\pi$-stacking area and Easy Crystallizability

  • Park, Jong-Won;Chung, Dae-Sung;Park, Jong-Hwa;Kim, Yun-Hi;Shim, Hong-Ku;Park, Chan-Eon;Kwon, Soon-Ki
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.98-100
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    • 2008
  • A series of new channel materials using triisopropylsilylethynyl anthracene(TIPSAN) derivatives are synthesized by well known reaction. The TIPSAN derivatives exhibit an excellent field-effect mobility with hole mobility as high as 0.1 cm2V-1s-1 by solution-process and slip stack structure of core and end groups with short $\pi-\pi$ stacking distance of $3.525{\sim}3.485\;{\AA}$ by single crystal structures.

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Formaldehyde 가스 흡입에 의한 마우스의 급성독성 및 소핵 유발성에 관한 연구

  • 김충용;김균;심점순;김용화;노정구
    • Toxicological Research
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    • 제7권1호
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    • pp.61-71
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    • 1991
  • The acute and genetic effect of formaldehyde on mice through inhalation route was studied. The Riley's chamber with one stack of cage was used for the exposure and the micronucleus test was performed under unprecedently maximum exposure concentration. LC50's of formaldehyde in mice by whole body exposure for 4 hours were 105.5 ppm with 95% confidence interval of 72.6 ppm and 143.2 ppm for male, and 159.2 ppm with 95% confidence interval of 116.5 ppm and 272.7 ppm for female. Cinicial symptoms by acute exposure were salivation, lacrimation, and abnormal respiration.

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친환경 디젤엔진용 차세대 피에조 인젝터의 구동성능 해석 (Analysis of the Driving Performance in Piezo Injector for Clean Diesel Engine)

  • 이진욱;강건용;민경덕
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2006년도 전기학술대회논문집
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    • pp.33-34
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    • 2006
  • In this study, a prototype piezo-driven Injector. as a new method driven by piezoelectric energy, has been designed and fabricated based on the concept of inverse piezo-electric effect to overcome the major drawbacks of conventional solenoid-driven injector with a fixed and slow control of injection rate. The effects of an electric control between the solenoid valve and piezo-ceramic stack for injector needle's driving on the dynamic characteristics were usually investigated. We found that this piezo-electric actuator has the main advantage to drastically reducing the time of injector nozzle opening, as well to exert higher force output levels.

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초고층 건물의 제연영향요소에 따른 수직피난공간 압력분포 시뮬레이션 (A Study on the Pressure Difference of Smoke Control Influence Factor in the Super High-rise Building)

  • 최승혁;이동윤;전현도;박진철
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2009년도 하계학술발표대회 논문집
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    • pp.130-135
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    • 2009
  • These days, the super high-rise buildings construction plans are increased in Korea. But the stack effect in the super high-rise building interrupts the smoke control system's operation because of pressure difference, so it is more dangerous than the general building when firing. Therefore it needs to study about the pressure difference in the super high-rise buildings. We research the smoke control influence factor in the super high-rise building. Reflecting the influence factor, the simulation is practiced the case by case.

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초고밀도 디스크 드라이브를 위한 저밀도 작동 환경에서 서보 트랙 기록 방법에 대한 연구 (Servo Track Writing for Ultra-High TPI Disk Drive in Low Density Medium Condition)

  • 한윤식;김철순;강성우
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 춘계학술대회논문집
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    • pp.736-741
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    • 2004
  • In high-capacity disk drives with ever-growing track density, the allowable level of position error signal (PES) is becoming smaller and smaller. In order to achieve the high TPI disk drive, it is necessary to improve the writing accuracy during the STW(servo track writing) process through the reduction of TMR sources. Among the main contributors of the NRRO(Non-Repeatable Run-out) PES, the disk vibration and the HSA(head-stack assembly) vibration is considered to be one of the most significant factors. Also the most contributors of RRO(Repeatable Run- out) come from the contributors of NRRO which is written-in at the time of STW(servo track writing) process. In this paper, the experimental test result shows that the effect of NRRO on servo written-in RRO effectively can be reduced through a STW process under low dense medium condition such as semi-vacuum.

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건축화재시 피난대책에 관한 연구 -고층건물의 제연을 중심으로- (A Study on the Smoke Proof Measure of High Rise Buildings.)

  • 이영재;이근영
    • 한국화재소방학회논문지
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    • 제4권1호
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    • pp.3-12
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    • 1990
  • This study is to Present the air Pressurization system of staircase as a way to decrease the injury of human life which is suffocated by smoke when the fire break out in building. 1) The best among an air pressurization system of stairshaft Is multiple air Injection system established to be situated an air injection point in each layer. 2) If the air pressurization system is also applied to the elevator accessory room to use commonly, it can prevent from the smoke spreading and pollution inside building caused by stack effect of elevator shaft. 3) For the reasonable and safe escape and air pressurization system must be carried out from the project of basic shape of building under the close cooperation with architect and fire protection expert.

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국내의 연기제어 관련 소방법과 건축법의 변천과정에 관한 연구 (A Study on the Historical Comparative of Smoke Control for Fire Safety Law and Building Law)

  • 김혜원;진승현;권영진
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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    • pp.97-98
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    • 2017
  • These days the buildings are getting higher, bigger, and in a deep. According to that, it was the Large-Scale casuality by smoke from Daeyeongak Hotel fire in 1971 to Uijeongbu apartment fire in 2015, and the law of smoke control has consistently changed. but the analysis for improving the law isn't working. Therefore on this study, it conducts the analysis of historical comparative about smoke control and it will present the basic data for improving the law of smoke control and in-depth analysis.

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공동주택에 대한 Shaft Box형 이중외피의 적용에 관한 연구 (A Study on Application of Shaft-box Type Double Skin to Apartment Building)

  • 노지웅
    • KIEAE Journal
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    • 제13권1호
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    • pp.75-81
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    • 2013
  • The balcony of our apartment building consists of unique construction similar to double skin. It is announced broadly that double skin is very effective system in improvement of natural ventilation and indoor thermal environment, and outdoor sound protection. So, for the improvement of indoor climate and energy saving, many peoples studied about environmental performance of our balcony construction. This study focus on shaft box facade, special form of box window construction. It consists of a system of box window with continuous vertical shafts that extend over a number of stories to create a stack effect. Proto-type was decided by analyzing various types of exiting apartments. Shaft box type balcony was created by setting up shaft space at a part of balcony. Air flow and contribution of air temperature were simulated, performance of shaft box type balcony was compared with existing balcony. Finally, we confirmed that shaft box type balcony has many possibility for improvement of indoor environment.

Nondestmctive Evaluation of Cracks in Metal Plates by using SQUID Gradiometer

  • 황윤석;김진태;이순걸;박용기
    • Progress in Superconductivity
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    • 제3권2호
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    • pp.159-162
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    • 2002
  • We have detected cracks inside multi-layer metal sheets with nondestructive evaluation system consisting of SQUID gradiometer. Double D-shape coil was carefully designed with computer simulation for spatial distribution of magnetic field. It was aligned and placed in between SQUID and metal sheets in order to reduce the field effect to SQUID and to maximize eddy current in the sheets. The metal plate in bottom of the metal stack contained artificial cracks which were scanned by an X-Y scanning system. The information of crack position and size could be estimated by analysis of SQUID signal. Details of the results will be discussed .

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