• Title/Summary/Keyword: Channel Junction

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Flume Experiments on Channel Morphology at a Tributary Junction (하천 합류점의 하도형상에 관한 수로실험)

  • Taeho Kim
    • Journal of the Korean Geographical Society
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    • v.33 no.3
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    • pp.355-364
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    • 1998
  • Flume experiments are conducted to describe the channel morphology at a tributary junction and to examine the influence of channel arrangements and hydrologic conditions on the channel morphology. When flow momenta of two tributaries are equal, a receiving stream tends to align with an axis bisecting junction angle. It causes lateral migration of a receiving stream according to an initial channel arrangement. As a result, the post-fonfluent channel morphology varies with plan geometry of a confluence such as symmetry, transition and asymmetry. Bed scour is the most notable morphology within a junction site. Its shape is characterized by steep walls which are primarily influenced by junction angle. Key control of scour dimension is also junction angle. Although the principle of accordant junction has been undoubtedly accepted, discordance is commonly developed at model and natural stream confluences. Unit discharge ratio of confluent streams is the most crucial factor because both discharge and sediment concentration ratios have an effect on discordance at a junction.

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Effect of Ginseng Saponin on Gap Junction Channel Reconstituted with Connexin 32

  • Hong, Eun-Jung;Huh, Keun;Rhee, Seung-Keun
    • Archives of Pharmacal Research
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    • v.19 no.4
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    • pp.264-268
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    • 1996
  • Panax-ginseng saponin has been known to exert various pharmacological effects on cellular metabolism. This study was performed to determine the effect of ginseng saponin on gap junction channel-mediated intercellular communication, using an established in vitro system of reconstituted gap junction channels. Gap junction channels are a specialized plasma membrane fraction, which are permeable to relatively large water-soluble molecules. The sucrose permeable property of reconstituted gap junction channels was completely inhibited with 0.1 % (w/v) of ginseng saponin. We also compared the effect of ginseng saponin with that of Triton X-100, a nonionic detergent, on the same system. Triton X-100 showed significantly different effect on sucrose-permeability of gap junction channel from that was affected by ginseng saponin. The structures of liposomes containing gap junction channels was significantly destroyed by Triton X-100.

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Numerical Study on the Droplet Flows in a Cross-Junction Channel Using the Lattice Boltzmann Method (Lattice Boltzmann 법을 이용한 Cross-Junction 채널 내의 droplet 유동에 관한 수치해석적 연구)

  • Park, Jae-Hyoun;Suh, Young-Kweon
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2006.11a
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    • pp.407-410
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    • 2006
  • This study describes a simulation of two-dimensional bubble forming and motion by the Lattice Boltzmann Method with the phase field equation. The free energy model is used to treat the interfacial force and deformation of binary fluids system, drawn into a T-junction the micro channel. A numerical simulation of a binary flow in a cross-junction channel is carried out by using the parallel computation method. The aim in this investigation is to examine the applicability of LBM to numerical analysis of binary fluid separation and motion in the micro channel.

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The Variation of Channel Bed by Location of Pier near 90° Channel Junction (90° 합류부를 지닌 수로에서 교각 위치에 따른 하상변동)

  • Choi, Gye-Woon;Kim, Young-Kyu;Kim, Gee-Hyoung
    • Journal of Korea Water Resources Association
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    • v.37 no.9
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    • pp.781-787
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    • 2004
  • The variation of channel bed which shows the complex hydraulic characteristics at channel junction was investigated by variation of discharge ratio and location of pier. As discharge ratio increase, the depth and width of erosion region become bigger to point of 63% of channel width in case of 1:0.5 discharge ratio. It was observed that the maximum scour depth at the point of 0.5 times of the channel width in the channel junction as 2.5 times bigger than straight channel. It means that the maximum scour depth at the channel junction is 2 times greater than by experimental formulas which are widely used in practical engineering, location of pier should be determined when it is installed in channel junction.

Mechanism for Gating of Gap Junction Channel. (간극결합채널의 개폐기전)

  • 오승훈
    • Journal of Life Science
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    • v.14 no.5
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    • pp.882-890
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    • 2004
  • Gap junction is a membrane structure facilitating the direct transmission of several ions and small molecules between two cells. It is also called an 'intercellular channel' to distinguish it from other well-known cellular channels (e.g. sodium and potassium channels). Gap junction channels are not passive conduits, rather the ion channels modulated by several stimuli including pH, calcium ion, voltage, and a chemical modification (mainly known as phosphorylation). Among them, the effects of voltage on the gating of gap junction channels have been well studied. Gap junction channels are more sensitive to the transjunctional potential ($V_j$) between two cells rather than the membrane potential($V_m$) between inside and outside the cell. In this review, I will summarize the general properties of gap junction channel and discuss the gating mechanism for the gap channels.

A Study on the Hydraulic Characteristics of River Junctions Using FLDWAV Model (FLDWAV 모형을 이용한 하천합류부에서의 수리학적 특성 연구)

  • Cho, Hyeon-Kyeong
    • Journal of the Korean Society of Industry Convergence
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    • v.10 no.4
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    • pp.275-283
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    • 2007
  • This study aims at the calculation of a variation of flow characteristics of main channel for tributary inflow in river junction. So this study was analyzed the variation of flow depth and velocity in main channel for a change of inflow degree. For this purpose, FLDWAV model are carried out for variations of $30^{\circ}$, $60^{\circ}$ and $90^{\circ}$ tributary inflow at junction. Results show that velocity ratio(V1/V3) increases and flow depth ratio(H1/H3) decreases for discharge ratio(Q1/Q3) of upstream and downstream when degree increases in junction. And FLDWAV model was applied at a real river junctions. Selected area is a junction of Gumho river and Sin stream. Results show that pattern is similar to a virtual channel.

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Comparison of Drain-Induced-Barrier-Lowering (DIBL) Effect by Different Drain Engineering

  • Choi, Byoung-Seon;Choi, Pyung-Ho;Choi, Byoung-Deog
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.342-343
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    • 2012
  • We studied the Drain-Induced-Barrier-Lowering (DIBL) effect by different drain engineering. One other drain engineering is symmetric source-drain n-channel MOSFETs (SSD NMOSs), the other drain engineering is asymmetric source-drain n-channel MOSFETs (ASD NMOSs). Devices were fabricated using state of art 40 nm dynamic-random-access-memory (DRAM) technology. These devices have different modes which are deep drain junction mode in SSD NMOSs and shallow drain junction mode in ASD NMOSs. The shallow drain junction mode means that drain is only Lightly-Doped-Drain (LDD). The deep drain junction mode means that drain have same process with source. The threshold voltage gap between low drain voltage ($V_D$=0.05V) and high drain voltage ($V_D$=3V) is 0.088V in shallow drain junction mode and 0.615V in deep drain junction mode at $0.16{\mu}m$ of gate length. The DIBL coefficients are 26.5 mV/V in shallow drain junction mode and 205.7 mV/V in deep drain junction mode. These experimental results present that DIBL effect is higher in deep drain junction mode than shallow drain junction mode. These results are caused that ASD NMOSs have low drain doping level and low lateral electric field.

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The Analysis of Hydraulic Characteristics at Channel Junctions through Hydraulic Model Tests (수리모형실험을 통한 합류부에서의 수리학적 특성분석)

  • Choi, Gye-Woon;Park, Young-Suop;Han, Man-Shin;Kim, Young-Gyu
    • Journal of Korea Water Resources Association
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    • v.37 no.10
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    • pp.881-888
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    • 2004
  • In this study, the hydraulic characteristics at junction are studied through the variation of approaching angle, discharge in the upstream channel and the discharge ratio between the main channel and the tributary. The maximum velocity as well as the position of the maximum velocity is included in the hydraulic characteristics. The maximum velocity is increased by increasing of approaching angle, discharge in the upstream channel and the discharge ratio between the main channel and the tributary. The length from the channel junction to the point of maximum velocity is increasing by increasing of approaching angle, discharge in the upstream channel and the discharge ratio between the main channel and the tributary.

Effect of Bundle Junction Face and Misalignment on the Pressure Drops Across a Randomly Loaded and Aligned 12 Bundles in Candu Fuel Channel

  • H. C. Suk;K. S. Sim;C. H. Chung;Lee, Y. O.
    • Nuclear Engineering and Technology
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    • v.28 no.3
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    • pp.280-289
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    • 1996
  • The pressure drop of twelve fuel bundle string in the CANDU-6 fuel channel is equal to the sum of the eleven junction pressure losses, the bundle string entrance and exit pressure losses, the skin friction pressure loss, and other appendage pressure losses, where the junction loss is dependent on the bundle end faces and angular alignments of the junctions. The results of the single junction pressure drop tests in a short rig show that the most probable pressure drop of the eleven junctions was analytically equal to the eleven times of average pressure drop of all the possible single junction pressure drops, and also that the largest and smallest junction pressure drops across the eleven junctions probably occurred only with BA and BB type junctions, respectively, where A and B denote the bundle end sides with an end-plates on which a company monogram is stamped and unstamped, respectively.

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Design and Fabrication of Buried Channel Polycrystalline Silicon Thin Film Transistor (Buried Channel 다결정 실리콘 박막 트랜지스터의 설계 및 제작)

  • 박철민;강지훈;유준석;한민구
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.35D no.12
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    • pp.53-58
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    • 1998
  • A buried channel poly-Si TFT (BCTFT) for application of high performance integrated circuits has been proposed and fabricated. BCTFT has unique features, such as the moderately-doped buried channel and counter-doped body region for conductivity modulation, and the fourth terminal entitled back bias for preventing kink effect. The n-type and p-type BCTFT exhibits superior performance to conventional poly-Si TFT in ON-current and field effect mobility due to moderate doping at the buried channel. The OFF-state leakage current is not increased because the carrier drift is suppressed by the p-n junction depletion between the moderately-doped buried channel and the counter-doped body region.

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