• Title/Summary/Keyword: Variation of Thickness

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Effect of Variation of Membrane Thickness on the Activity of $Ca^{2+}$-activated $K^+$ Channel in Planar Lipid Bilayers

  • Seo, Hyoung-Sik;Ryu, Pan-Dong
    • Proceedings of the Korean Biophysical Society Conference
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    • 1999.06a
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    • pp.56-56
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    • 1999
  • Change of membrane property can affect the activity of membrane proteins. In this work, we investigated the single channel properties of large conductance $Ca^{2+}$-activated $K^{+}$(BK) channels in planar lipid bilayers of different thickness. First, we recorded the activity of single BK channels from rat skeletal muscle incorporated into the control bilayer, then increased the bilayer thickness by perfusing the recording solution with the one saturated with n-pentane, or reduced the thickness by adding diheptanoylphosphatidylcholine (di$C_{7:0}$PC) to the recording soluton.(omitted)

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Electrical and thermal characteristics of PRAM with thickness of phase change thin film (상변화 박막의 두께에 따른 상변화 메모리의 전류 및 열 특성)

  • Choi, Hong-Kyw;Kim, Hong-Seung;Lee, Seong-Hwan;Jang, Nak-Won
    • Journal of Advanced Marine Engineering and Technology
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    • v.32 no.1
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    • pp.162-168
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    • 2008
  • In this paper, we analyzed the heat transfer phenomenon and the reset current variation of PRAM device with thickness of phase change material using the 3-D finite element analysis tool. From the simulation, Joule's heat was generated at the contact surface of phase change material and bottom electrode of PRAM. As the thickness of phase change material was decreased, the reset current was highly increased. In case thickness of phase change material thin film was $200\;{\AA}$, heat increased through top electrode and reset current caused by phase transition highly increased. And as thermal conductivity of top electrode decreased, temperature of unit memory cell was increased.

Efforts of Specimen Sizes on Crack Opening Displacement (COD) for Submerged Arc Weldments of Fine Grained Steel (미세립강 잠호 용접부의 COD에 미치는 시편 크기의 영향)

  • 윤중근;김대훈;김문일
    • Journal of Welding and Joining
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    • v.1 no.2
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    • pp.53-60
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    • 1983
  • COD test based on fracture mechanics concept was used in this study to evaluate the fracture toughness quantitatively. Effects of specimen sizes on critical COD value for ABS EH 36 steel and its submerged arc weldments, and the variation of critical COD value depending on metallurgical/mechanical heterogeneities caused by weld thermal cycles were investigated. Experiment was performed by using specimens made from base metal and submerged arc weldments according to BS 5762. Obtained results are summarized as follows; 1) Critical COD value for base metal decreases with increasing thickness of specimen. On hand, as the reduction ratio of critical COD decreases with increasing specimen thickness, critical COD value becomes constant above a thickness of specimen. 2) Critical COD value for weldment decreases with increasing thickness of specimen and was also affected by metallurgical states of base metal. 3) Size effects for weldment was greater at the hardened region. 4) Critical COD value was affected by microstructural change due to weld thermal cycles in weldments; that is, accicular ferrite formation is favorable for increasing of COD value.

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Optimization of Heat Insulation System for a Household Refrigerator (가정용 냉장고의 단열 최적화)

  • 박진구
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.2
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    • pp.95-102
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    • 2003
  • Optimization for the insulation thickness and external shape of a household refrigerator is peformed in order to minimize thermal load through the insulation wall. The one dimensional conduction heat transfer model is adopted to calculate thermal load. Calculus of variation is employed to optimize the thickness and shape of refrigerator or freezer. The uniform distribution of an insulation thickness and cubed external shape make thermal load minimize. Finally, by using both of the computational and experimental method, the thermal load is minimized for a refrigerator/freezer. It is shown that there exists optimal thickness of insulation walls and external shape for given the external cabinet dimensions and freezer and refrigerator internal volumes, Also, the analytical results are well agreed with the experimental results.

A Study on Thickness Variation of ABS Sheet in Vacuum Forming Process (진공성형시 발생하는 ABS 시트의 두께 변화량에 관한 연구)

  • 양화준;최재원;이석희;장태식;이일엽
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.663-666
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    • 2002
  • Originally, the thermoforming method has been developed to produce the plastic parts which have simple geometric characteristics such as door trims and wrapping materials within the short time. But the thermoformed parts have non-uniform thickness distributions over the surface according to the material characteristics, set-up angle and geometry of the parts. But, only few analysis methods have been developed so far, due to the difficulties of the selection of important factors, and contribution of each factor in the simulation. So, to guarantee the dimensional accuracy and mechanical properties of crucial points in the thermoformed parts, it is necessary to develop the thickness prediction method. This research suggests a new approaching methodology to predict the thermoformed parts by modulating the control points of the NURBS curve. The newly developed method makes it possible not only to choose the suitable thickness of polymer sheets but also to induce data modification for vacuum forming.

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지지부 위치와 벽면 두께변화에 따른 구형 인공위성 추진제 탱크의 강도해석

  • 한근조;전언찬;김중완;안성찬;심재준
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.528-532
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    • 1997
  • The structure of satellite was of six parts of control system, power system, thermal control system, remote measurement command system, propellant system and thrust system. In these parts, propellant system consists of propellant tank and thrust device. What we want to perform is optimum design to minimaize the weight of propellant tank. In order to design optimal propellant tank, several parameters should be adopted form the tank geometry like the relative location of the lug and variation of the wall thickness. So the analysis was executed by finite element analysis for finding optimal design parameters. The structure was devided into 3 parts, the initial thickness zone, the transitional zone, and the weak zone,whose effects on the pressure vessel strength was investigated. Finally the optimal lug location and the three zone thickness were obtained and the weight was compared with the uniform thickness vessel.

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NUMERICAL SIMULATION OF THE EFFECTS OF RESIN SUPPLY TEMPERATURE ON OPTICAL FIBER COATING THICKNESS (피복재 공급온도가 광섬유 피복두께에 미치는 영향에 대한 전산유동해석)

  • Choi, J.S.;Kwak, H.S.;Kim, K.
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.96-99
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    • 2011
  • Fiber coatings are essential in optical fiber manufacturing, since they provide the protective layers from the surface damages and the adequate fiber strength. Flow and temperature fields of coating liquid in a fiber coating applicator are numerically investigated by using a commercial CFD software. The main focus of this computational study is on the thermal effects by viscous dissipation and the effects of coating supply temperature on the final fiber coating thickness. The numerical results reveal that the thermal effects play a major role in the high-speed optical fiber coating process and give substantial influences on the determination of coating thickness. Changing the supply temperature of coating liquid is found to relieve the radial variation of coating liquid viscosity in the coating die and it can be an effective way to control the fiber coating thickness.

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A Study on the Fatigue Crack Propagation Behavior by the Variation of Heat Treatment Temperature and Thickness in Mild Steel (연강의 열처리 온도와 두께 변화에 따른 피로균열성장거동에 관한 연구)

  • 오환교
    • Journal of the Korean Society of Safety
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    • v.15 no.3
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    • pp.40-44
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    • 2000
  • The fatigue and tensile test were carried out with Mild steel using the Dump Frame of commercial car. The specimens were heat-treated at $810^{\circ}C$ and $930^{\circ}C$ and worked 4.5, 6.0, 8.0mm thickness in order to look over the mechanical properties and fatigue life by heat treatment and thickness from the tensile test result, the yield strength of the heat treated specimens was increased about 35% more than that of the non-heat treated specimen. The fatigue life of non-heated specimen was decreased 15% but that of heat treated specimens at $870^{\circ}C$ and $930^{\circ}C$ were decreased 16.38% and 13.16% respectably according to increasing the thickness from 4.5 to 8.0mm.

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Characteristic Analysis of the Asymmetric Coupled microstrip Lines with finite Metalization Thickness in the Multilayered Structure (다층구조에서 도체 두께를 고려한 비대칭 결합선로의 특성해석)

  • 윤남일;홍익표;박한규
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.3A
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    • pp.424-429
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    • 2000
  • In this paper, the characteristics of the asymmetric coupled microstrip(ACM) lines with finite metalization thickness are investigated using the quasi-static analysis in the multilayered structure. By mode-matching method as the quasi-static analysis. the characteristic impedances and effective dielectric constants in ACM lines are obtained as a function of metalization thickness. The numerical results show that the propagation characteristics of ACM lines in the single and multilayered structure will be changed by the variation of metalization thickness.

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Thickness Effects of Coupling Agent on Residual Bending Stress in $Polyimide/SiO_2$ Joints ($Polyimide/SiO_2$ 접합체에서 잔류굽힘응력에 미치는 Coupling Agent 두께의 영향)

  • Kong, Do-Il;Park, Chan-Eon;Hong, Seung-Taek;Yang, Hoon-Chul;Kim, Ki-Tae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.23 no.7 s.166
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    • pp.1085-1093
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    • 1999
  • Thickness effects of coupling agent on residual bending stress were investigated in $Polyimide/SiO_2$ joints during thermal cycling. Thickness and peel strength of $\gamma$-APS coupling agent were measured and correlated with solution concentration and residual bending stress. The variation of residual bending stress with temperature was also measured for various thicknesses of the coupling agent. Finite element results were compared with experimental data for residual bending stress in $Polyimide/SiO_2$ joints.