• Title/Summary/Keyword: Surface ordering

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Effect of Heat Treatment on Microstructures and Magnetic Properties of Rapidly Solidified Fe-6.5wt % Si sheet (급속응고된 Fe-6.5wt% Si 강판의 미세조직과 자기적 특성에 미치는 열처리의 영향)

  • Hwang, D.H.;Lee, K.H.;Lee, T.H.;Koo, J.M.
    • Journal of the Korean Society for Heat Treatment
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    • v.8 no.2
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    • pp.149-154
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    • 1995
  • The alloying of 6.5wt % Silicon in iron decreases the magnetization and the anisotropy and minimizes the iron loss noticeably. But it is very difficult to make thin sheets because of its poor ductility which is due to an ordering reaction (body centered cubic to CsCI type crystal structure). However the ordering reaction can be suppressed by rapid solidification method. The cooling rate of rapidly solidified Fe-6.5wt % Si alloy is about $10^3K/s$ and rapidly solidified structure are fine structure, cellular structure, dendrite and equiaxed grain from surface. The precipitates of $DO_3$ Phase emerges on $B_2$ matrix and the coercive force was 0.51 Oe (50cycle, 15KGauss) in Fe-6.5wt% Si alloy which was processed by heat treatment of $1150^{\circ}C$ for 1hr in high vacuum.

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A Study on the Orientational properties of Phospholipid Monolayers (지질단분자막의 배향 특성에 관한 연구)

  • Lee, Kyung-Sup;Kwon, Young-Soo
    • Proceedings of the KIEE Conference
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    • 1995.07c
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    • pp.1217-1219
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    • 1995
  • The organization of phospholipid monolayers on a water surface was investigated by means of Maxwell-Displacement-Current(MDC)-Measuring technique. The phase transition from the gaseous phase to the gaseous-fluid phase which accompanies the polar ordering of lipid molecules was detected by the technique in the range of immeasurable low surface pressure and the molcular-area which gives the onset of the transition was determined for lipid monolayers. The vertical component of dipole moment of lipid membranes was determined from the charge flowing the rough the circuit, and we measured differential themal analysis of sample.

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NON-COPLANAR MAGNETIC RECONNECTION AS A MAGNETIC TWIST ORIGIN

  • CHAE JONGCHUL
    • Journal of The Korean Astronomical Society
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    • v.32 no.2
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    • pp.137-147
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    • 1999
  • Recent studies show the importance of understanding three-dimensional magnetic reconnect ion on the solar surface. For this purpose, I consider non-coplanar magnetic reconnection, a simple case of three-dimensional reconnect ion driven by a collision of two straight flux tubes which are not on the same plane initially. The relative angle e between the two tubes characterizes such reconnection, and can be regarded as a measure of magnetic shear. The observable characteristics of non-coplanar reconnection are compared between the two cases of small and large angles. An important feature of the non-coplanar reconnect ion is that magnetic twist can be produced via the re-ordering of field lines. This is a consequence of the conversion of mutual helicity into self helicities by reconnection. It is shown that the principle of energy conservation when combined with the production of magnetic twist puts a low limit on the relative angle between two flux tubes for reconnect ion to occur. I provide several observations supporting the magnetic twist generation by reconnection, and discuss its physical implications for the origin of magnetic twist on the solar surface and the problem of coronal heating.

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Odd-Even Effects of the Anchoring Strength for Nematic Liquid Crystal on Rubbed Polyimide LB Surfaces (러빙처리된 폴리이미드막 LB막에 있어서 네마틱액정의 결합강도의 홀수짝수 효과)

  • Seo, Dae-Shik
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1453-1455
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    • 1996
  • The odd-even effect of the alkyl chain length of rubbed polyimide Langmuir-Blodgett (LB) surfaces on the extrapolation length of 5CB has been successfully evaluated for the first time by measuring polar anchoring strength. The extrapolation length of 5CB for rubbed PI-LB surfaces with even-numbers is small compared with odd-numbers for alkyl chain lengths of greater than 7 carbons. The extrapolation length of 5CB on rubbed PI-LB surfaces with odd-numbers increases gradually as the temperature increases but tends to diverge near the clearing temperature (Tc=$35.3^{\circ}C$). The extrapolation length diverges because of rapidly decreasing surface order near $T_c$. We suggest that the polar anchoring strength on rubbed PI-LB surfaces with even-number is strong because of relatively high surface ordering caused by more crystalline surfaces. Finally, we conclude that the odd-even effects of the polar anchoring strength in NLCs are strongly related to the character of the polymer and observed clearly for long alkyl chain lengths.

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Water-Repellent Macroporous Carbon Nanotube/Elastomer Nanocomposites by Self-Organized Aqueous Droplets

  • Lim, Bo-Kyung;Lee, Sun-Hwa;Park, Ji-Sun;Kim, Sang-Ouk
    • Macromolecular Research
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    • v.17 no.9
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    • pp.666-671
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    • 2009
  • Water repellent elastomeric surfaces were fabricated successfully on SBS/MWNT nanocomposites films using the breath figure method and subsequent thermal treatment. The uniformly dispersed CNTs were found to play significant roles in tuning the size and ordering of the macroporous morphology at the nanocomposite surface as well as enhancing the mechanical properties of nanocomposites. In particular, the CNTs dispersed in a nanocomposite solution retarded the coarsening process of aqueous droplets during the breath figure process and decreased the pore size in the finally fabricated film. The water contact angle measurement showed that the double-scale structure comprised of self-organized macropores and surface the roughness induced by a thermal treatment produced a highly water-repellent nanocomposite surface.

Differential Effects of Local Anesthetics on Rate of Rotational Mobility between Hydrocarbon Interior and Surface Region of Model Membrane Outer Monolayer

  • Chung, In-Kyo;Cha, Seong-Kweon;Chung, Yong-Za;Kim, Bong-Sun;Choi, Chang-Hwa;Cho, Goon-Jae;Jang, Hye-Ock;Yun, Il
    • The Korean Journal of Physiology and Pharmacology
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    • v.4 no.1
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    • pp.41-46
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    • 2000
  • Using fluorescence polarization of 12-(9-anthroyloxy)stearic acid (12-AS) and 2-(9-anthroyloxy)stearic acid (2-AS), we evaluated the differential effects of local anesthetics on differential rotational rate between the surface (in carbon number 2 and its surroundings including the head group) and the hydrocarbon interior (in carbon number 12 and its surroundings) of the outer monolayer of the total lipid fraction liposome extracted from synaptosomal plasma membrane vesicles. The anisotropy (r) values for the hydrocarbon interior and the surface region of the liposome outer monolayer were $0.078{\pm}0.001$ and $0.114{\pm}0.001,$ respectively. This means that the rate of rotational mobility in the hydrocarbon interior is faster than that of the surface region. In a dose-dependent manner, the local anesthetics decreased the anisotropy of 12-AS in the hydrocarbon interior of the liposome outer monolayer but increased the anisotropy of 2-AS in the surface region of the monolayer. These results indicate that local anesthetics have significant disordering effects on the hydrocarbon interior but have significant ordering effects on the surface region of the liposome outer monolayer.

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Effects of Local Anesthetics on the Rate of Rotational Mobility of Phospholipid Liposomes

  • Chung, In-Kyo;Kim, Dae-Gyeong;Chung, Yong-Za;Kim, Bong-Sun;Choi, Chang-Hwa;Cho, Goon-Jae;Jang, Hye-Ock;Yun, Il
    • BMB Reports
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    • v.33 no.3
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    • pp.279-284
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    • 2000
  • Using fluorescence probes, 2-(9-anthroyloxy) stearic acid (2- AS) and 12-(9-anthroyloxy) stearic acid (12-AS), we determined the differential effects of local anesthetics (tetracaine-HCI, bupivacaine-HCI, lidocaine-HCI, prilocaine-HCI and procaine-HCI) on the differential rotational rate between the surface (in carbon number 2 and its surroundings including the head group) and the hydrocarbon interior (in carbon number 12 and its surroundings) of the outer monolayer of the total phospholipid fraction liposome that is extracted from synaptosomal plasma membrane vesicles. The anisotropy (r) values for the hydrocarbon interior and the surface region of the liposome outer monolayer were$0.051{\pm}0.001$ and $0.096{\pm}0.001,$ respectively. This means that the rate of rotational mobility in the hydrocarbon interior is faster than that of the surface region. Local anesthetics in a dosedependent manner decreased the anisotropy of 12-AS in the hydrocarbon interior of the liposome outer monolayer, but increased the anisotropy of 2-AS in the surface region of the monolayer. These results indicate that local anesthetics have significant disordering effects on the hydrocarbon interior, but have significant ordering effects on the surface region of the liposome outer monolayer.

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Runoff Analysis by the Geomorphoclimatic Linear Reservoir Model (지형기후학적 선형저수지 모델에 의한 유출해석)

  • 조홍제
    • Water for future
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    • v.18 no.2
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    • pp.143-152
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    • 1985
  • A method is suggested for the reappearance of a surface runoff hudorgraph of a river basin by linking the hydrologic response of a catchment represented by the instantaneous unit hydrograph(IUH) with the Horton's empirical gemorphologic laws. The geomorphologic theory of the IUH developed by G. Itrube et al. and the geomorphoclimatic theory of the IUH developed by Bras et al. are used to derive the new hydrologic response function in consideration of geomorphologic parameters and climatic characteristics by applying to Sukekawa's rainfall-runoff model. The derived response function was tested for on some observed hydrographs in a natural watershed and showed promising, and by considering a drainage basin as m(1∼4) identical linear reservoir in series, it was founded that the model(m=2) is most applicable to predict hydrologic response regardless of the size of basins. A modelization algorithm of a basin using Sthahler's ordering scheme of drainage network will give good result in analysis of the surface runoff huydrograph by the method of this study.

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Magnetization Behavior of Ultra-thin FexCo1-x Alloy on Cr (100) Surface

  • Hossain, M.B.;Kim, C.G.;Chun, B.S.;Kim, W.;Hwang, C.Y.
    • Proceedings of the Korean Magnestics Society Conference
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    • 2013.05a
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    • pp.15-16
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    • 2013
  • Magnetization behavior of ultra thin $Fe_xCo_{1-x}$ alloy (where x varies from 0 to 100) has been investigated as functions of composition on Cr (100) substrate by using in situ surface magneto optical Kerr effect (SMOKE). It's always show in plane uniaxial magnetic anisotropy at room temperature (RT) & Low temperature (LT). It is observed that composition dependent coercive force maximum at about 30 at % Co and 70 at % Co atomic ratio and minimum near equiatomic site. The relative magnetic moments as composition variation also show magnetization collapse near equiatomic site. The magnetization behaviors of Fe-Co alloy on Cr (100) due to composition varies are supported the order-disordering as well as structural stability bcc (ferromagnetic)/fcc (anti-ferromagnetic) phase stability magnetism.

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Interface and Crystallinity of 1,4,5,8,9,11-Hexaazatriphenylene-hexanitrile thin films between an Organic and Transparent Conductive Oxide layers

  • Lee, Hyeon-Hwi;Lee, Jeong-Hwan;Kim, Jang-Ju;Kim, Hyo-Jeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.248-248
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    • 2016
  • We have investigated the crystallinity, preferential ordering, and interfacial stability of 1,4,5,8,9,11-hexaazatriphenylene-hexanitrile (HATCN) thin film interconnected with organic/inorganic multilayer. At the region close to the organic-organic interface, HATCN formed low crystalline order with substantial amorphous phase. As film growth continued, HATCN stacked with high crystalline phase. After a sputtering deposition of the indium zinc oxide (IZO) layer on top of HATCN/organic layer, the volume fraction of preferentially ordered HATCN crystals increased without any structural deterioration. In addition, the HATCN surface was kept quite stable by preserving the sharp interface between HATCN and sputtering deposited IZO layers.

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