• Title/Summary/Keyword: Korean inclination

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Experimental Study on Spreading Flame over Slanted Polyethylene Insulated Electrical Wire with AC Electric Field (전기장이 인가된 상태에서 폴리에틸렌으로 피복된 기울어진 전선을 통해 전파하는 화염에 대한 실험적 연구)

  • Lim, Seungjae;Kim, Minkuk;Park, Jeong;Chung, Sukho;Fujita, Osamu
    • 한국연소학회:학술대회논문집
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    • 2014.11a
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    • pp.187-190
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    • 2014
  • An experimental study on downwardly and upwardly spreading flames over slanted electrical wire, which is insulated by Polyethylene(PE), was conducted with applied AC electric field. The result showed that downwardly and upwardly spreading flames with angle of inclination leaned toward burnt side and unburned side, respectively. With applied AC electric fields, size of downwardly spreading flame decreased slightly and that of upwardly spreading flame increased significantly. Flame spread rate showed various trends in terms of inclination, applied voltage and frequency.

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Experimental Study on Effect of AC Electric Field on Upwardly Spreading Flame over Polyethylene insulated Electrical Wire (폴리에틸렌으로 피복된 전선을 통해 위로 전파하는 화염에 대한 교류전기장 효과에 대한 실험적 연구)

  • Lim, Seungjae;Kim, Minkuk;Park, Jeong;Chung, Sukho;Fujita, Osamu
    • 한국연소학회:학술대회논문집
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    • 2014.11a
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    • pp.363-365
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    • 2014
  • An experimental study on effect of AC electric field on upwardly spreading flame over electrical wire, which is insulated by Polyethylene(PE), was conducted. The result showed that upwardly spreading flame leaned toward unburned side with angle of inclination. With applied electric field, size of upwardly spreading flame increased significantly. Flame spread rate showed various trends with inclination, applied voltage and frequency.

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An Experimental Study on the Heat Transfer Characteristics in Miniature Heat Pipes with Screen Wick (스크린 윅을 삽입한 소형 히트파이프에서 열전달 특성에 관한 실험적 연구)

  • Park, K.H.;Lee, K.W.;Ko, Y.K.;Lee, K.J.;Chun, W.P.
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.572-578
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    • 2001
  • This study is to research the heat transfer characteristics in copper-water heat pipes with screen wick, #100. Recently, the semiconductor capacity of an electronic unit has been larger, on the contrary, its size is smaller than before. As a result, a high-performance cooling system is needed. Experimental variables are inclination angle and temperature of cooling water. The distilled water was used for the working fluid. At a inclination angle ${-6}^{\circ}$, #100 2layer screen mesh is shown the best heat transfer performance.

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A Numerical Study on the Mixed Convection in Open-Ended Inclined Channels (양 끝이 개방된 경사진 채널 내에서의 혼합대류에 관한 수치적 연구)

  • Piao Ri-Long;Bae Dae-Seok
    • Journal of Advanced Marine Engineering and Technology
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    • v.29 no.1
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    • pp.78-85
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    • 2005
  • A numerical calculation is performed to study the effects of buoyancy force on the heat transfer characteristics of laminar forced convection flow in inclined parallel plates with the upper part cooled and the lower Part heated uniformly. Numerical results are presented for the Reynolds number ranges from $4.0\times10^{-3}$ to $1.13\times10^{-1}$. the angle of inclination, $\theta$. from 0 to 90 degree and Pr of the high viscosity fluid is 909. It is found that the flow pattern of mixed convection in inclined parallel Plates can be classified into four patterns which affected by Reynolds number and the angle of inclination.

A Study on the Capillary Limitation in Copper-Water Heat Pipes with Screen Wicks (스크린 윅을 삽입한 동-물 히트파이프에서 모세관 한계에 관한 연구)

  • 박기호;이기우;노승용;이석호;유성연
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.12
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    • pp.1023-1030
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    • 2002
  • This paper is to research the heat transfer characteristic performance of the copper-water heat pipe with the screen wicks. Recently, the semiconductor capacity of an electronic unit has been larger, on the contrary, its size has been much smaller. As a result, a high-performance cooling system is needed. Experimental variables are inclination angles, temperatures of cooling water and the mesh number of screen wicks. The distilled water was used for the working fluid. At the inclination angle $6^{\circ}$ in top heat mode, the two layers of the 100-mesh screen wick showed the best heat transfer performance. The thermal resistance of the two layers with the 100-mesh screen was 0.7~$0.8^{\circ}C$/W.

Clearance Depth Control of Non-explosive Demining System (비폭파식 지뢰제거 시스템의 작업 깊이 제어)

  • Jeong, Hae-Kwan;Choi, Hyun-Do;Kim, Sang-Do;Kwak, Yoon-Keun
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.749-754
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    • 2004
  • Up to now, non-explosive demining system adaptable to a mobile robot has been developed. This system has much smaller platform and consists of non-explosive mechanism. Brief experiment indoors showed thai developed demining system can remove landmines well. But, out of doors, some problems are detected i.e. Inclination of overall system causes a suspension of rake rotation. In this research, a study on performance improvement of developed non-explosive demining system is mainly discussed. To compensate the inclination of the system, mechanical sensor composed of shaft and spring is used. This sensor gives a signal to a leadscrew motor and controls a rotating direction. From an experiment, it is confirmed that the mechanical sensor as stated is a good solution of the inclination of the system.

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Flow Characteristics in the Converging Mini-Channels (좁아지는 유로에서의 유동 특성)

  • Karng, Sarng-Woo;Kim, Jin-Ho;Lee, Yoon-Pyo
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.1623-1628
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    • 2004
  • Recently mini-channels or micro-channels are widely used for cooling the high density power electronic devices. Especially, the channels are used in small and high efficient equipments such as heat pipes and heat exchangers. Interfacial velocities between liquid and gas phases are very important in mini or micro-channels. In this paper, an experiment and a numerical analysis on the interfacial velocities were performed. In the experiment, the interfacial velocities which were measured by the high-speed CCD camera were about $26{\sim}33$ cm/s and the velocities increased as the inclination angle did. In the numerical experiment, CFD-ACE+, a commercial program, was used, the velocities had similar values with experimental results. As the inclination angle and the contact angle increased, the interfacial velocities did because of the surface tension which causes to move the interface. The effect of inclination angle was larger in the converging channels than in straight channels.

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Experimental Study on Film Boiling Heat Transfer of Spray Cooling for Inclined heat transfer Surface (경사면에서의 분무냉각 막비등 열전달에 관한 실험적 연구)

  • Kim, Yeung-Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.22 no.1
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    • pp.33-39
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    • 2010
  • The film boiling heat transfer was experimentally investigated for the water sprays impacting on an inclined hot surface. Full cone spray nozzles were employed for the spray cooling experiment, and experiments were made for different inclination angles of $\theta=0^{\circ}$, $15^{\circ}$, $30^{\circ}$ and $45^{\circ}$. The experimental results show that, in the downstream region of the inclined hot surface, increasing the inclination angle increases the local heat flux slowly because of increasing the number of rebound droplets. However, the inclination angle of heat transfer surface had no remarkable effect on the local heat flux of spray cooling under the present test conditions.

A Study on the Spray Cooling Characteristics according to the Angle of Hot Heat Transfer Surface (고온 열전달면의 각도에 따른 분무냉각 특성에 관한 연구)

  • Yoon, D.H.;Oh, C.;Yoon, S.H.
    • Journal of Advanced Marine Engineering and Technology
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    • v.26 no.3
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    • pp.320-327
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    • 2002
  • An experimental study of heat transfer from hot flat surface to water sprays was conducted in high temperature region. Heat transfer measurements for hot flat surface were made by 4 sheathed C-A thermocouples. Droplets volume flux were also measured-independently at a position in spray field. The test conditions included variations in droplets volume flux, subcooling of cooling water of $1.565\times10^{-3} to 14.089\times10^{-3}m^3/m^2s and 80 to $20^{\circ}C$ respectively. The effects of inclination angle on heat transfer were investigated and changes in inclination angle of hot flat surface affected heat transfer coefficients of high temperature region.

Brassinosteroid-like Activity of Monoglyceride Analogues (Monoglyceride 관련물질의 Brassinosteroid-like 생물활성)

  • Park, Jong-Dae;Park, Keun-Hyung
    • Applied Biological Chemistry
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    • v.40 no.4
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    • pp.357-360
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    • 1997
  • The biological activity of monoglycerides, diglycerides, triglycerides and free fatty acids were investigated by the rice inclination test that is specific bioassay for brassinosteroids. The experimental results revealed that some diglycerides, triglycerides and free fatty acids as well as monoglycerides showed positive response. ${\alpha}-Monoolein$ and diolein as active principles showed higher activity than indole-3-acetic acid at the same concentration. From the results, it can be confirmed that the active principles are related to olein which especially have a high activity.

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