• Title/Summary/Keyword: bilayer structure

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Effects of Lipid Composition on the Properties of Phospholipid Liposomal Membranes (리포솜 지질막의 성질에 미치는 지질 조성의 영향)

  • Kim, Min;Han, Suk-Kyu;Kim, Chong-Kook
    • YAKHAK HOEJI
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    • v.38 no.2
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    • pp.131-139
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    • 1994
  • Calcein-encapsulated small unilamellar vesicles of various lipid composition were prepared using the sonication technique, and their stabilities at $20^{\circ}C$ were examined by measuring calcein leakage from the liposomes. The fluidity of these liposomal bilayers was also investigated by measuring the fluorescence polarization of DPH labelled into the liposomes. The results showed that liposomes made of PC mixtures with different acyl chain length were very stable, which may be due to the formation of interdigitated bilayer structure. The addition of cholesterol further stabilized these PC liposomes. However, addition of cholesterol reduced the encapsulation efficiences of liposomes. The fluidity of the liposomes was significantly decreased by cholesterol in the liquid crystalline state, but not changed in the gel state. These results suggest that the enhanced stability of PC mixture liposomes may be ascribed to the formation of stable interdigitated bilayer structure. In membrane-mimetic and drug-delivery studies, vesicles made of mixtures of various phospholipids are recommended instead of addition of cholesterol to the phospholipid.

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Growth and properties of LCMO/YBCO heterostructure

  • Kumar, Manish;Lee, Hyun Hwi
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.151.1-151.1
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    • 2016
  • Complex oxide heterointerfaces have been extensively explored in the past due to the novel phenomenon emerging at such interfaces that differ from their individual bulk counterparts. The integration of a ferromagnetic (FM) material with the superconducting (SC) material leading to proximity effect is one of the commonly studied phenomenon in these heterostructures. In continuation, we have stabilized the FM layer La0.7Ca0.3MnO3 (LCMO) on SC material YBa2Cu3O7-${\delta}$ (YBCO) using pulsed laser deposition technique and explored the structural, magnetic, electrical and magneto-transport properties of this heterostructure. ${\Phi}$-scan measurements confirm the epitaxial nature of LCMO/YBCO heterostructure grown on single crystalline SrTiO3 substrate. The FM transition of LCMO and SC transition of YBCO are observed in the magnetization measurements of the bilayer structure. Through electrical measurements, we understood that the proximity effect leads to lowering of the SC transition of YBCO. The role of interface in the bilayer structure is also realized through electrical transport measurements.

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XRD study of the layered structure compounds [Zn${(H_2O)}_6$] (${(C_{n}H_{2n+1}SO_3)}_2$ (층상구조인 [Zn${(H_2O)}_6$ (${(C_{n}H_{2n+1}SO_3)}_2$ 화합물에 대한 X-선 회절 연구)

  • 박용준;박양순;이종규;박성훈;전태현;허영덕
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.10 no.4
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    • pp.318-323
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    • 2000
  • The intercalated compounds of alkylsulfonates into hydrated zinc were synthesized. From the high temperature powder X-ray diffraction (HTXRD), FT-IR, and molecular size, the temperature dependence of orientation for the intercalated alkylsulfonates were determined. In the temperatures range 1, alkylsulfonates were intercalated into hexa aqua zinc layer with the bilayer structure of $32.9^{\circ}$angle for ${Zn(H_2O_4]^{2+}[C_nH_{2n+1}SO_3]_2\;^-$. In the temperatures range 2, alkylsulfonates were intercalated into tetra aqua zinc layer with the bilayer structure of $55.2^{\circ}$angle for ${Zn(C_nH_{2n+1}SO_3)_2$. In the temperatures range 3, alkylsulfonates were directly bonded to zinc ion with the bilayer structure of $76.5^{\circ}$angle for ${Zn(C_nH_{2n+1}SO_3)_2$.

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Strength and Reliability of Porous Ceramics Measured by Sphere Indentation on Bilayer Structure

  • Ha, Jang-Hoon;Kim, Jong-Ho;Kim, Do-Kyung
    • Journal of the Korean Ceramic Society
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    • v.41 no.7
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    • pp.503-507
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    • 2004
  • The importance of porous ceramics has been increasingly recognized and adequate strength of porous ceramics is now required for structural applications. Porosities of porous ceramics act as flaws in inner volume and outer surface which result in severe strength degradation. The effect of pore structure, however, on strength and reliability of porous ceramics has not been clearly understood. We investigate the relationship between pore structure and mechanical properties using a sphere indentation on bilayer structure, porous ceramic top layer with soft polymer substrate. Porous alumina and silica were prepared to characterize the isolated pore structure and interconnected pore structure, respectively. The porous ceramic with 1mm thickness were bonded to soft polycarbonate substrate and then fracture strengths were estimated from critical loads for radial cracking of porous ceramics during sphere indentation from top surface. This simple and reproducible technique provides Weibull modulus of strength of porous ceramics with different pore structure. It shows that the porous ceramics with isolated pore structure have higher strength and higher Weibull modulus as well, than those with interconnected pore structure even with the same porosity.

Synthesis and Characterization of Intercalation Compounds of Alkylsulfonate into Hydrated and Dehydrated Zinc (수화된 아연과 탈수된 아연에 알킬술폰이 층간 삽입된 화합물의 합성과 구조)

  • Huh, Young Duk;Park, Sung Hun;Jun, Tae Hyun;Park, Yong Jun;Park, Yang Sun
    • Analytical Science and Technology
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    • v.13 no.3
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    • pp.338-345
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    • 2000
  • The intercalated compounds of alkylsulfonate into hydrated and dehydrated zinc were synthesized. From the XRD, FT-IR, TGA, elemental analysis data, and the molecular size, the orientation of the intercalated alkylsulfonates was determined. For the hydrated compounds, alkylsulfonates were intercalated into hexaqua zinc layer with the bilayer structure of $32.9^{\circ}$ angle of inclination. For the dehydrated compounds, alkylsulfonates were directly bonded to zinc ion with the bilayer structure of $51.4^{\circ}$ angle of inclination.

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Structural change of cobalt dodecanesulfate (Cobalt dodecanesulfate의 구조변화)

  • 허영덕;권석순;김지현
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.14 no.2
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    • pp.63-67
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    • 2004
  • The layered structure of cobalt dodecanesulfate was synthesized. A phase transition takes place at various temperature ranges and results in a drastic change of the layer distance. A monolayer structure of cobalt dodecanesulfate at room temperature transformed to a bilayer structure as a dehydrated form at high temperature.

Synthesis and structure of ($C_6CH_2NH_3)_2CUCl_4and \;(NH_3C_6C_4C_2H_4C_6NH_3)CUCl_4$ (($C_6CH_2NH_3)_2CUCl_4와 \;(NH_3C_6C_4C_2H_4C_6NH_3)CUCl_4$의 합성과 구조)

  • 김지현;권석순;현준원;허영덕
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.14 no.4
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    • pp.135-139
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    • 2004
  • The layered organic-inorganic hybrid compounds($C_6H_5CH_2NH_3)_2CuCl_4$ and ($NH_3C_6/H_4C_2H_4_6/H_4NH_3)CuCl_4$ have been directly synthesized. From the X-ray diffraction data and the organic guest size, the orientation of the intercalated organic amine was determined. The inorganic sheets consist of $CuCl_4^{2-}$layers of comer-sharing octahedra copper chloride. The protonated organic amine was intercalated into the $CuCl_4^{2-}$layers with bilayer structure for ($C_6H_5CH_2NH_3)_2CuCl_4$ and monolayer structure for ($NH_3C_6/H_4C_2H_4_6/H_4NH_3)CuCl_4$.

Finite Element Method (FEM) Study on Space Charge Effects in Organic Light Emitting Diodes (OLED)

  • Kim, Kwang-Sik;Hwang, Young-Wook;Won, Tae-Young
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.12 no.4
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    • pp.467-472
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    • 2012
  • In this paper, we present a finite element method (FEM) study on the space charge effects in organic light emitting diodes. The physical model covers all the key physical processes in OLEDs, namely charge injection, transport and recombination, exciton diffusion, transfer and decay as well as light coupling, and thin-film-optics. The exciton model includes generation, diffusion, and energy transfer as well as annihilation. We assumed that the light emission originates from oscillation which thus is embodied as exciton in a stack of multilayer. We discuss the accumulation of charges at internal interfaces and their signature in the transient response as well as the electric field distribution. We also report our investigation on the influence of the insertion of the emission layer (EML) in the bilayer structure.

Thermal behavior of the layered structure of decanesulfonate intercalated into the hydrated nickel compound (데칸술폰이 삽입된 니켈 화합물의 층상 구조의 열적 성질)

  • 허영덕;전태현;박용준
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.9 no.6
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    • pp.580-584
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    • 1999
  • The synthesis and characterization of intercalated compound of decansulfonate into hydrated nickel is presented. The compound shows a layered structure as determined by high temperature powder X-ray diffraction (HTXRD). The layer distance of the product is increased from 24.7 $\AA$ to 30.5 $\AA$ by increasing the temperature which is in turn accomplished by changing the structure of the intercalated nickel compound. From the X-ray diffraction data and the decanesulfonate size, the orientation of the decanesulfonate onto the nickel layer is determined. The molecular axis of the decanesulfonate with bilayer structure is tilted to the perpendicular of the nickel layer.

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