• Title/Summary/Keyword: Channel forming

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Dependence of Flat Fluorescent Lamp (FFL) Efficiency on Channel Number and Channel Length (채널 개수 및 길이에 따른 면광원 램프의 효율 비교에 관한 연구)

  • Hur, Jeong-Wook
    • Journal of the Semiconductor & Display Technology
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    • v.8 no.2
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    • pp.43-47
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    • 2009
  • Glass forming technology is used to form channels of external electrode flat fluorescent lamps (FFL). The efficiency of FFL depends on the number and the length of the channels. Five FFLs with same size ($300\;mm{\times}80\;mm$), different channel number, and different channel length were fabricated. The electrical and optical characteristics of 5 FFLs were evaluated. It was found that the FFL with one channel with its channel length of 1,110 mm and channel width of 7 mm corner width was shown to have the highest efficiency at room temperature operation.

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Cloning of a pore-forming subunit of ATP-sensitive potassium channel from Clonorchis sinensis

  • Hwang, Seung-Young;Han, Hye-Jin;Kim, So-Hee;Park, Sae-Gwang;Seog, Dae-Hyun;Kim, Na-Ri;Han, Jin;Chung, Joon-Yong;Kho, Weon-Gyu
    • Parasites, Hosts and Diseases
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    • v.41 no.2
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    • pp.129-133
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    • 2003
  • A complete cDNA sequence encoding a pore-forming subunit (Kir6.2) of ATP-senstive potassium channel in the adult worm, Clonorchis sinensis, termed CsKir6.2, was isolated from an adult CDNA library. The cDNA contained a single open-reading frame of 333 amino acids, which has a structural motif (a GFG-motif) of the putative pore-forming loop of the Kir6.2. Peculiarly, the Cskir6.2 shows a lack-sequence structure, which deleted 57 amino acids were deleted from its N-terminus. The predicted amino acid sequence revealed a highly conserved sequence as other known other Kir6.2 subunits. The mRNA was weekly expressed in the adult worm.

Springback Control in the Forming Processes for High-Strength Steel Sheets (고강도 강판 성형 공정의 스프링백 제어)

  • Yang WooYul;Lee SeungYeol;Keum YoungTag;Hwang JinYoung;Yoon ChiSang;Shin ChirlSoo;Cho WonSuk
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.08a
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    • pp.35-40
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    • 2003
  • In order to develope springback control technology for high-strength steel sheets, some studies have been conducted: dome stretching test, stepped s-rail forming and springback measurement, and optimally shaped initial blank design. First, to find out the formability of TRIP60, dome stretching test was performed. Next the stepped s-rail die, which was designed to form a channel type panel with large twist and wall curl, was manufactured and used to know the effect of controlling forming variables, such as blank holding force and flange amount on the springback. Furthermore, new measurement method of the springback was introduced to define wall curl and twist in geometrically complex panels. Finally, the optimally shaped initial blank was employed to verify one of the best ways to control the springback in channel type, high strength sheet panels.

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Ab Initio Study of Mechanism of Forming Germanic Bis-Heterocyclic Compound between Dimethyl-Germylene Carbene (Me2Ge=C:) and Acetone

  • Lu, Xiuhui;Che, Xin;Lian, Zhenxia;Li, Yongqing
    • Bulletin of the Korean Chemical Society
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    • v.32 no.1
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    • pp.89-94
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    • 2011
  • The mechanism of the cycloaddition reaction of forming germanic bis-heterocyclic compound between singlet dimethylgermylene carbene and acetone has been investigated with CCSD(T)//B3LYP/6-$31G^*$ method. From the potential energy profile, it can be predicted that, this reaction has one dominant channel. The presented rule of this dominant channel is that the two reactants firstly form a four-membered ring carbene (RC4) through the [2+2] cycloaddition reaction. Due to $sp^2$ hybridization of carbene C atom in RC4, RC4 further combines with acetone to form a reactant complexe (RC5). Due to the further $sp^3$ hybridization of carbene C atom in RC4, RC5 isomerizes to a germanic bisheterocyclic compound (P6) via the transition state (TS5).

Heating and Cooling Channel Design of Cross-Shaped Die for Warm Forming of Magnesium Alloy Sheet (Mg 온간성형을 위한 십자형상 금형의 가열/냉각 채널 설계)

  • Choi, S.C.;Ko, D.S.;Kim, H.Y.;Kim, H.J.;Hong, S.M.;Ryu, S.Y.;Shin, Y.S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2008.05a
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    • pp.370-373
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    • 2008
  • It is known that the temperatures of die, punch, holder and punch pad need to be kept different to get better formability in Mg sheet forming processes. Heating and cooling channels are usually equipped in each tool to assign different temperature. This study focused on the optimal design of the heating and cooling channels for a cross-shaped deep drawing die set. While the die and blankholder were heated to and kept at $250^{\circ}C$ by using heat cartridges, the punch and punch pad were kept at much lower temperature than that of the die and blankholder by water circulating through cooling channels. All the approaches were done by numerical analyses, aiming to maximize the cup height and to minimize the punch corner radius without any failure.

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Detection of Noise Sources in a Cavitation Tunnel by using Beam-Forming Method (빔형성 기법을 이용한 공동수조 내부의 소음원 탐지)

  • 이정학;서종수
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.05a
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    • pp.749-754
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    • 2003
  • In this paper, we introduce the measurement of the underwater noise with 32channel hydrophone array of Samsung CAvitation Tunnel (SCAT) and the detection technique of noise sources by using the beam-forming method. Measurement and way signal Processing under fluid flow are essential works for the underwater acoustics, especially for the detection of noise sources. As the acoustic impedance of the water is relatively high and the tunnel is an enclosed system, we have to consider the interaction between tunnel and water together with the reflection of noise in the beam-forming technique. Also, for a hydrophone array system that is fixed on one side of tunnel wall as done in SCAT is liable to suffer from some limitations in the detection of the noise sources with the array, we discuss these limitations particularly on the frequency range and spacing of noise sources.

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Tolaasin Forms Various Types of Ion Channels in Lipid Bilayer

  • Cho, Kwang-Hyun;Kim, Young-Kee
    • Proceedings of the Korean Biophysical Society Conference
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    • 1998.06a
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    • pp.34-34
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    • 1998
  • Tolaasin is a channel forming bacterial toxin produced by Pseudomonas tolaasii and causes a brown blotch disease on cultivated oyster mushrooms. When tolaasin molecules form channels in the membranes of mushroom cells, they destroy cellular membrane structure, known as 'colloid osmotic lysis'. In order to understand the molecular mechanisms forming membrane channels by tolaasin molecules, we have investigated the electrophysiological characteristics of tolaasin-induced channels in lipid bilayer.(omitted)

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Numerical Study of Heat Transfer Enhancement on Microchannel Plate Heat Exchanger with Channel Shape (채널 형상에 따른 마이크로채널 판형 열교환기 열전달 성능 향상에 관한 수치 연구)

  • Jeon, Seung-Won;Kim, Yoon-Ho;Lee, Kyu-Jung
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.1888-1893
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    • 2007
  • In this study, the microchannel plated heat exchanger were numerically studied for the enhancement of heat transfer in the channel configuration. Unit cold and hot fluid region with the microchannel were modeled and periodic boundary condition at the side wall was applied to continuously repeating geometry. The material of micro-structured plate is STS304 and working fluid is water. Triangular obstacles were placed in micro channel to enhance heat transfer. The performance of microchannel plated heat exchangers were numerically investigated with various obstacle configuration and Reynolds number under the parallel and counter flows. Heat transfer rate has increased about 18% compared with straight channel, but pressure drop also increased about 3.5 times. The main factor of increasing of pressure drop and heat transfer rate is considered that the momentum was lost to collide against obstacles, generation of secondary flow and boundary layer separation, wake and vortex forming phenomena.

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Flow Analysis of Reverse Flow in a Channel with High Angle of Attack (받음각이 큰 평판 채널 내의 역류 유동 해석)

  • Choi, Seung;Sohn, Chang-Hyun
    • Journal of the Korean Society of Visualization
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    • v.5 no.1
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    • pp.37-42
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    • 2007
  • Reverse flow occurs in a channel when there is an obstruction at the entry. However it has been shown recently that reverse flow can be realized without an obstruction, by staggering the sides of the channel and placing it at an angle of attack to the oncoming flow. In this study the latter flow is computationally investigated. Studies have been carried out for different widths (gap between the two walls forming the channel), and at an angle of attack of 30. The results have captured all the essential features of this complex phenomenon and show the time dependent pumping mechanism which leads to the occurrence of reverse flow.