• Title/Summary/Keyword: ordered structure

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A Molecular Dynamics Simulation on the Self-assembly of ABC Triblok Copolymers. 2. Effects of Block Sequence

  • Jo, Won-Ho;Ko, Min-Jae;Kim, Seung-Hyun
    • Fibers and Polymers
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    • v.3 no.1
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    • pp.8-13
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    • 2002
  • The effect of block sequence on the self-assembly of ABC-type triblock copolymers in the ordered state is investigated using an isothermal-isobaric molecular dynamics simulation. The block sequence has an important effect ,on the ]norphology of ABC triblock copolymers. Different morphologies are observed depending on the block sequence as well as the block composition. The triblock copolymers with the volume fraction of 1 : 1 : 1 ($f_A$=$f_B$=$f_C$= 0.33) show the three phase and four layered lamellar structures irrespective of the block sequence. The $A_{32}$$B_{16}$$C_{32}$triblock copolymer with $f_B$=0.2 shows a morphology In which cylinders of midblock B are formed at the interface between A and C lamellae, whereas the morphology of triblock copolymer $B_{16}$$C_{32}$ $A_{32}$ and $C_{32}$ $A_{32}$ $B_{16}$ show a cylindrical core-shell structure and a lamellar type morphology, respectively. The $A_{20}$$B_{40}$$C_{20}$the triblock copolymer with the block B as a major component shows a tricontinuous structure, whereas both $B_{40}$$C_{20}$$A_{20}$ and $C_{20}$$A_{20}$$B_{40}$ triblock coolymers exhibit the lamellar structures. When the block B has larger volrome fraction with $f_B$=0.75, the matrix is composed of block B, and other two blocks A and C form spherical domains.

Analysis on the Car Ownership Structure Considering Household Car Ownership Pattern (가구별 차량보유패턴을 고려한 차량 보유구조 분석)

  • Lee, Jeong Hun;Jung, Hun Young
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.4
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    • pp.667-675
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    • 2016
  • The goal of this study is to be used as baseline data for transportation demand management. At the present time the number of registered car and householding car is increasing, so there is a need to analyze the car ownership pattern through household car hold status. Also, it is necessary to analyze the factor of increasing car. The research is proceeded with classifying as the household which is holding private cars or holding passenger cars and non passenger cars based on the result of the research of the household travel survey data. The result of this study is shown as follows. According to car ownership pattern, there are more households holding passenger cars only when they are holding less than 2 cars. Otherwise there are more households holding passenger car and non passenger car when they are holding more than 3 cars. Using the Ordered Logit Model, there are more differences in factors affects holding cars by variables of housing type and household properties.

Nano-structure and Magnetic Properties of FePd Superlattice Thin Film (FePd 인공격자박막의 나노구조 및 자기적 특성)

  • Kang, J.G.;Chung, I.S.;Koo, J.W.;Koh, J.H.;Koo, S.M.;Nam, S.M.;Ha, J.G.
    • Journal of the Korean Magnetics Society
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    • v.18 no.5
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    • pp.190-194
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    • 2008
  • Epitaxial $L1_0$ FePd (001) thin films were successfully manufactured by sputtering deposition method. The structure and magnetic properties of FePd thin films were characterized as a function of Fe compositions. It was found that the long-range ordering parameter had a maximum for the stoichiometric composition, whereas the magnetic anisotropy had a maximum as the Fe content is decreased to slightly above the stoichiometric composition. This indicates that the stoichiometry is directly contributed to the chemical ordering and the magnetic anisotropy. These results imply that nonstoichiometric FePd compositions, with a slight excess of Pd, may in fact be preferred for applications that require high magnetic anisotropy.

A Series of 3D Lanthanide Complexes Containing (La(III), Sm(III) and Gd(III)) Metal-organic Frameworks: Synthesis, Structure, Characterization and Their Luminescent Properties

  • Zhang, Huai-Min;Yang, Hao;Wu, Lan-Zhi;Song, Shuang;Yang, Li-Rong
    • Bulletin of the Korean Chemical Society
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    • v.33 no.11
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    • pp.3777-3787
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    • 2012
  • Three kinds of 3D isomorphous and isostructural coordination polymers, namely, $\{[Ln_2(PDA)_3(H_2O)_3]{\cdot}0.25H_2O\}_{\infty}$ (Ln = La(1), Sm(2), and Gd(3)) ($PDA^{2-}$ = pyridine-2,6-dicarboxylate anion) have been synthesized under hydrothermal conditions and characterized by elemental analyses, IR spectroscopy, thermal analyses and single crystal X-ray diffraction. In these MOFs, Ln(III) centers adopt eight-coordinated and nine-coordinated with the $N_1O_7$ and $N_2O_7$ donor sets to construct distorted trianglar dodecahedron geometry and tricapped trigonal prism configurations, respectively. Based on the building block of tetranuclear homometallic $Ln_4C_4O_8$ unit (16-membered ring), 1-3 are connected into highly ordered 2D sheets via O-C-O linkers and further constructed into 3D architectures through hydrogen bonds. Crystallographic parameters suggest that the lanthanide contraction effect exist in these coordination polymers. Luminescent properties of the lanthanide-based MOFs (metal-organic frameworks) have been measured at room temperature, which reveal that they presenting ionselective characters toward certain metals, such as $Mg^{2+}$, $Cd^{2+}$ and $Pb^{2+}$ ions.

An Analysis on Preference of Interior Coordination Elements for Urban Small Housing - Focused on Gold-Generation(Gold Miss, Gold Mr.) - (도시형 소형주택의 실내코디네이션 요소 선호 분석 - 골드세대(골드미스, 골드미스터) 수요자를 중심으로 -)

  • Kim, So-Hee;Han, Young-Ho
    • Korean Institute of Interior Design Journal
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    • v.21 no.5
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    • pp.264-271
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    • 2012
  • As changed population structure variously, population decrease is one of the important problem in present urbanization. It resulted decline of the medium-large size housings that increasing of 1-2 person household need the variety of small housing with housing type. This study was researched the Gold-Generation on theme by Gold Miss, Gold Mr. who preferring urban small housings that it analyzed survey of Gold generation who be wanted urban small housing by interior coordination elements. Data to be analyzed that first, Gold Mr. and Miss are preferred two bedroom applied by spatial structure coordination. Especially it is based on the separation between livingroom and bedroom with duplex type which is bathroom formed single unit type(shower/toilet/basin). In interior coordination of spatial elements, Gold Mr. considered the form of kitchen with huge ㄷ type instead of Gold Miss are preferred alpha room or alpha space to use powder room or dress room. Second, In Preference of interior coordination elements, Gold Mr. and Miss are preferred bed-clothes and curtains by fabrics, lighting are hanging and spot lighting, accessories are carpet with rug and porcelains. Color are preferred bright scheme both white and ivory, however preference of furniture is different from Gold Mr. and Gold Miss that Gold Mr. are ordered desk, sofa and shelves but Gold Miss are preferred sofa, bed, and dressing table. It showed between Gold Mr. and Gold Miss are equal needs or differences. It expects the basic research for understanding the interior coordination elements for preference in urban small housing as focused on Gold generation(Gold Miss, Gold Mr.) that they will be applied the interior space on urban small housing.

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Identification of Nuclear Factors that UV-crosslink to Rev-responsive Element RNA (UV조사에 의해 Rev-responsive element RNA와 결합하는 핵단백질인자의 확인)

  • 박희성;남용석
    • Journal of Life Science
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    • v.7 no.3
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    • pp.161-166
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    • 1997
  • HIV-1 Rev protein plays an important role in regulating the expression of viral structural proteins. It allows the nuclear export and accumulation of unspliced and partially spliced viral mRNA in the cytoplasm. The Rev-responsive element RNA, present in the env gene, forms a higly ordered RNA secondary structure and is required for the Rev-mediated mRNA export. For this process to complete factor(s) are strongly suggested. From our experiments of electrophoretic mobility shift, UV-crosslinking and SDS/PAGE, RRE RNA was found to be recognized to several nuclear factors such as 36/37, 56, 41. 76, 150 kD proteins in the order of reactivity. Among them, 36/37 and 56 kD proteins are more reactive upon a brief UV treatment (5 min) and more persistent in the presence of high amount of nonspecific competitor, heparin. Certain nuclear protein9s) seemed to recognize the RRE RNA structure in competition with Rev to gel mobility shift assay.

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Crystal Structures and Electrochemical Properties of LiNi1-xMgxO2 (0≤x≤0.1) for Cathode Materials of Secondary Lithium Batteries (리튬 이차전지의 양극 활물질 LiNi1-xMgxO2 (0≤x≤0.1)의 결정구조 및 전기화학적 특성)

  • Kim, Deok-Hyeong;Jeong, Yeon Uk
    • Korean Journal of Metals and Materials
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    • v.48 no.3
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    • pp.262-267
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    • 2010
  • $LiNi_{1-x}Mg_xO_2$(x=0, 0.025, 0.05, 0.075, 0.1) samples were synthesized by the solid-state reaction method. The crystal structure was analyzed by X-ray powder diffraction and Rietveld refinement. $LiNi_{1-x}Mg_xO_2$samples give single phases of hexagonal layered structures with a space group of R-3m. The calculated cation-anion distances and angles from the Rietveld refinement were changed with Mg contents in $LiNi_{1-x}Mg_xO_2$. The thicknesses of $NiO_2$ slabs were increased and the distances between the $NiO_2$ slabs were decreased with the increase in Mg contents in the samples. The electrical conductivities of sintered $LiNi_{1-x}Mg_xO_2$ samples were around $10^{-2}$ S/cm at room temperature. The electrochemical performances of $LiNi_{1-x}Mg_xO_2$were evaluated by coin cell test. Compared to $LiNiO_2$, $LiNi_{0.95}Mg_{0.05}O_2$ exhibited improved high-rate capability and cyclability due to the well-ordered layered structure by doping of Mg ion.

An Algorithm For Approximating The Performance of Multi-mode Network System Using Algebraic Property of System States (시스템 상태의 대수적 성질을 이용한 다중모드 네트워크 시스템 성능 근사계산 알고리즘)

  • Oh, Dae-Ho
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.12
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    • pp.127-137
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    • 2009
  • A practical algorithm of generating most probable states in decreasing order of probability of the network system state is suggested for approximating the performance of multi-mode network system using algebraic structure of the system states. Most complex system having network structure with multi-mode unit state is difficult to evaluate the performance or reliability due to exponentially increasing size of state space. Hence not an exact computing method but an approximated one is reasonable approach to solve the problem. To achieve the goal we should enumerate the network system states in order as a pre-processing step. In this paper, we suggest an improved algorithm of generating most probable multi-mode states to get the ordered system states efficiently. The method is compared with the previous algorithms in respective to memory requirement and empirical computing time. From the experiment proposed method has some advantages with regard to the criterion of algorithm performance. We investigate the advantages and disadvantage by illustrating experiment examples.

Structure and Arterial Relaxing Activity of Substance P-related Peptides and Substance P analogs (Substance P-related peptide들과 유도체의 구조 및 혈관이완 활성)

  • KIM Eun Jung;KIM Chan-Hee;GO Hye-Jin;KIM In Hae;AN Sang Hyun;SOHN Hee-Young;PARK Hee Yeon;YOON Ho Dong;CHANG Young-Chae;HONG Yong-Ki;PARK Nam Gyu
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.38 no.3
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    • pp.143-147
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    • 2005
  • Relationship between structure and biological activity was performed using the five substance P-related peptides (SPRPs) [mammalian-SP (M-SP), cod-SP (C-SP), trout-SP (T-SP), lungfish-SP (L-SP) and Ranakinin] and four SP analogs [[$His^5$]-SP (5H-SP), [$Gly^5$]-SP (5G-SP), ($Ile^8$)-SP (8I-SP) and ($Trp^8$)-Ranakinin (8W-Ranakinin)]. The circular dichroism (CD) spectra showed that all of the peptides took an unordered structure in buffer solution and artificial liposomes. However, 8W-Ranakinin undergoes conformational changes by being transferred into neutral and acidic liposomes from an unordered structure to more ordered structure. The arterial relaxing effect of the peptides was also studied with guinea-pig aorta (GPA), As a result of the studies, L-SP was about 14-fold more potant than M-SP. The order of potency compared to $EC_{50}$ value was $L-SP{\gg}M-SP>5G-SP{\ge}8I-SP>5H-SP>T-SP$, C-SP, Ranakinin, 8W-Ranakinin.

Microstructure and Morphology of Carbide Precipitates in $Ni_3Al$ and TiAl ($Ni_3Al$과 TiAl 중에 석출한 탄화물의 미세구조와 형태)

  • Han, Chang-Suk;Koo, Kyung-Wan;Kim, Jang-Woo
    • Journal of the Korean Society for Heat Treatment
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    • v.19 no.1
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    • pp.10-19
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    • 2006
  • Microstructure and morphology of precipitates in $Ni_3Al$- and TiAl-based intermetallics containing carbon have been investigated in terms of transmission electron microscopy(TEM). In an $L1_2$-ordered $Ni_3Al$ alloy with 4 mol.% of chromium and 0.2~3.0 mol.% of carbon, fine octahedral precipitates of $M_{23}C_6$ type carbide were formed in the matrix by aging at temperatures around 973 K after solution annealing at 1423 K. TEM examination revealed that the $M_{23}C_6$ phase and the matrix lattices have a cube-cube orientation relationship and keep partial atomic matching at the {111} interface. After prolonged aging or by aging at higher temperatures, the $M_{23}C_6$ precipitates then adopt a rod-like morphology elongated parallel to the <100> directions. In the $L1_0$-ordered TiAl containing 0.1~2.0 mol.% carbon, TEM observations revealed that needle-like precipitates, which lie only in one direction parallel to the [001] axis of the $L1_0$ matrix, appear in the matrix and preferentially at dislocations. Selected area electron diffraction(SAED) patterns analyses have shown that the needle-shaped precipitate is $Ti_3AlC$ of perovskite type. The orientation relationship between the $Ti_3AlC$ and the $L1_0$ matrix is found to be $(001)_{Ti3AlC}//(001)_{L10\;matrix}$ and $[010]_{Ti3AlC}//[010]_{L10\;matrix}$. By aging at higher temperatures or for longer period at 1073 K, plate-like precipitates of $Ti_2AlC$ with a hexagonal structure are formed on the {111} planes of the $L1_0$ matrix. The orientation relationship between the $Ti_2AlC$ and the $L1_0$ matrix is $(0001)_{Ti2AlC}//(111)_{L10\;matrix}$ and $_{Ti2AlC}//_{L10\;matrix}$.