• Title/Summary/Keyword: Phase diagram

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Rich Phase Separation Behavior of Biomolecules

  • Shin, Yongdae
    • Molecules and Cells
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    • v.45 no.1
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    • pp.6-15
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    • 2022
  • Phase separation is a thermodynamic process leading to the formation of compositionally distinct phases. For the past few years, numerous works have shown that biomolecular phase separation serves as biogenesis mechanisms of diverse intracellular condensates, and aberrant phase transitions are associated with disease states such as neurodegenerative diseases and cancers. Condensates exhibit rich phase behaviors including multiphase internal structuring, noise buffering, and compositional tunability. Recent studies have begun to uncover how a network of intermolecular interactions can give rise to various biophysical features of condensates. Here, we review phase behaviors of biomolecules, particularly with regard to regular solution models of binary and ternary mixtures. We discuss how these theoretical frameworks explain many aspects of the assembly, composition, and miscibility of diverse biomolecular phases, and highlight how a model-based approach can help elucidate the detailed thermodynamic principle for multicomponent intracellular phase separation.

Crystal Structure Analysis of Uranium Oxides (산화우라늄의 결정구조 분석)

  • 김정석;최용남;이창희;김시향;이영우
    • Journal of the Korean Ceramic Society
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    • v.38 no.11
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    • pp.967-972
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    • 2001
  • The crystal and defect structures of U $O_{x}$(x=2.0, 2.03, 2.14, 2.19, 2.20 and 2.26) were analysed by rietveld refinement and the results were compared to the U-O phase diagram. Neutron diffraction data were collected in the temperature range of RT~100$0^{\circ}C$. The specimens of x=2.14, 2.19, and 2.20 consisted of two phase: $UO_{2+x}$(Fm3m, a≒5.4$\AA$) and $U_4$$O_{9}$(I43d, a≒21.8$\AA$). The proportion of the $UO_{2+x}$(Fm3m) phase increased with increasing the temperature. The variation of the proportion of the two phases with temperature in the U $O_{2.2}$ and U $O_{2.18}$ samples showed some deviation from the expected values from the phase diagram especially at the high temperature range. The phase transitions ${\gamma}$longrightarrow$\beta$longrightarrow$\alpha$ of $U_4$$O_{9}$ were discussed in relation with the phase separation.eparation.ion.

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Microstructures and Electrochemical Properties of Si-M (M : Cr, Ni) as Alloy Anode for Li Secondary Batteries (리튬이차전지용 Si-M (M : Cr, Ni) 합금 음극의 미세구조와 전기화학적 특성)

  • Lee, Sung-Hyun;Sung, Jewook;Kim, Sung-Soo
    • Journal of the Korean Electrochemical Society
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    • v.18 no.2
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    • pp.68-74
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    • 2015
  • To compare the microstructure and electrochemical properties between two binary alloys (Cr-Si, Ni-Si), two composition of binary alloys with the same capacity were selected using phase-diagram and prepared by matrix-stabilization method to suppress the volume expansion of Si by inactive-matrix. Master alloys were made by Arc-melting followed by fine structured ribbon sample preparation by Rapid Solidification Process (RSP, Melt-spinning method) under the same conditions. Also powder samples were produced by wet grinding for X-Ray Diffraction (XRD) and electrochemical measurements. As predicted from the phase diagram, only active-Si and inactive-matrix ($CrSi_2$, $NiSi_2$) were detected. The results of Scanning Electron Microscope (SEM) and Transmission Electron Microscopy - Energy Dispersive X-ray Spectroscopy (TEM-EDS) show that Cr-Si alloy has finer microstructure than Ni-Si alloy, which was also predictable through phase diagram. The electrochemical properties related to microstructure were evaluated by coin type full- and half-cells. Separately, self-designed test-cells were used to measure the volume expansion of Si during reaction. Volume expansion of Cr-Si alloy electrode with finer microstructure was suppressed significantly and improved in cycle capability, in comparison Ni-Si alloy with coarse microstructure. From these, we could infer the correlation of microstructure, volume expansion and electrochemical degradation and these properties might be predicted by phase diagram.

An Implementation Scheme for the Detection System of RFID Defective Tags Using LabVIEW OOP

  • Jung, Deok-Gil;Jung, Min-Po;Cho, Hyuk-Gyu;Lho, Young-Uhg
    • Journal of information and communication convergence engineering
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    • v.9 no.1
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    • pp.21-26
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    • 2011
  • In this paper, we suggest the object-oriented methodology for the design and implementation scheme for the program development in the application of control and instrumentation such as the detection system of RFID defective tags which needs the embedded programming. We apply the design methodology of UML in the system design phase, and suggest the implementation scheme of LabVIEW programs using LVOOP(LabVIEW Object Oriented Programming)in which make it possible to write the object-oriented programming. We design the class diagram and the sequence diagram using UML, and write the classes of LVOOP from the designed class diagram and the main VI from the sequence diagram, respectively. We show that it is possible to develop the embedded programs such as the RFID application through the implementation example of the detection system of RFID defective tags in this paper. And, we obtain the advantages based on the object-oriented design and implementation using the LVOOP approach such as the development of LabVIEW programs by adding the classes and the concept of object of the object-oriented language to LabVIEW.

Coordinated Intra-Limb Relationships and Control in Gait Development Via the Angle-Angle Diagram (보행 시 연령에 따른 하지 관절 내 운동학적 협응과 제어)

  • Lee, Kyung-Ok
    • Korean Journal of Applied Biomechanics
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    • v.14 no.3
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    • pp.17-35
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    • 2004
  • The purpose of this study is to explain developmental process of gait via angle-angle diagram to understand how coordinated relationships and control change with age. Twenty four female children, from one to five years of age were the test subjects for this study, and their results were compared to a control group consisting of twenty one adult females. The Vicon 370 CCD camera, VCR, video timer, monitor, and audio visual mixer was utilized to graph the gait cycle for all test subjects. Both coordinated Intra-limb relationships, and range of motion and timing according to quadrant were explained through the angle angle diagram. Movement in the sagittal plane showed both coordinated relationships and control earlier than movement in the coronal or transverse plane. In the sagittal plane, hip and Knee coordinated relationships developed first (from one year of age.) Coordinated relationships in the Knee and ankle and hip and ankle developed next, respectively. Both hip and ankle and knee and ankle development were inhibited by the inability of children to completely perform plantar flexion during the swing and initial double limb support phases. Children appeared to compensate for this by extending at their hip joint more than adults during the third phase, final double limb support. In many cases the angle angle diagram for children had a similar shape as adult's angle angle diagram. This shows that children can coordinate their movements at an early age. However, the magnitudes and timing of children's angle angle diagrams still varied greatly from adults, even at five years of age. This indicates that even at this age, children still do not possess full control of their movements.

Design and Implementation of A Conceptual Class Diagram Elicitation System (개념클래스 다이어그램 도출 시스템의 설계 및 구현)

  • Park, Ga-Young;Lee, Yong-Hun;Lee, Sang-Bum
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.1
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    • pp.420-426
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    • 2011
  • In this paper, we introduce a system which helps to draw a conceptual class diagram from the problem description by combining various class diagram deriving methods. Generally, problem description is a kind of statements including user requirements in the early development phase. The system developer can derive a conceptual class diagram from this document, which playes an important role during the object-oriented software development. Until now, it is not easy for the novice to elicit classes because it requires good experience and intuition. In addition, there are also some difficulties of finding valid conceptual classes by hand when the size of system becomes larger. Therefore, we develop a system to solve these problems so that the developer is able to construct the conceptual class diagram easily.

Recent trends in studies of biomolecular phase separation

  • Kim, Chan-Geun;Hwang, Da-Eun;Kumar, Rajeev;Chung, Min;Eom, Yu-Gon;Kim, Hyunji;Koo, Da-Hyun;Choi, Jeong-Mo
    • BMB Reports
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    • v.55 no.8
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    • pp.363-369
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    • 2022
  • Biomolecular phase separation has recently attracted broad interest, due to its role in the spatiotemporal compartmentalization of living cells. It governs the formation, regulation, and dissociation of biomolecular condensates, which play multiple roles in vivo, from activating specific biochemical reactions to organizing chromatin. Interestingly, biomolecular phase separation seems to be a mainly passive process, which can be explained by relatively simple physical principles and reproduced in vitro with a minimal set of components. This Mini review focuses on our current understanding of the fundamental principles of biomolecular phase separation and the recent progress in the research on this topic.

A simplified phase diagram in the ternary system $Y_2O_3-Ta(Nb)_2O_5-ZrO_2$ ($Y_2O_3-Ta(Nb)_2O_5-ZrO_2$ 삼성분계 상태도)

  • 이득용;김대준;장주웅;이명현
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.7 no.3
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    • pp.377-383
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    • 1997
  • Yttria-stabilized TZP alloyed with pentavalent oxides $(Ta_2O_5,\;Nb_2O_5)$ were fabricated by the conventional sintering method at $1500^{\circ}C$ in air to construct the simplified ternary phase diagram. The phase stability of tetragonal -$ZrO_2$ from the quasi-binary system $ZrO_2-YTa(Nb)O_4$, which do not transform to monoclinic-$ZrO_2$ even for a wide range of grain size and annealing temperature, was investigated to determine composition region of the non-transformable $t-ZrO_2$ solid solution$(NT_{ss})$. Phase stability of $NT_{ss}$ was probably due to the enhanced stability of $_YTa(Nb)O4$ having the tetragonal fergusonite structure. It was experimentally found that mixtures having $NT_{ss}$ alloyed with $T_{ss}$ by weight%% showed both excellent phase stability of $t-ZrO_2$ and fracture toughness even though the calculated composition of the mixture /was located outside $NT_{ss}$ composition region.

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Study of Thermally Induced Phase Separation of Polyvinylidene Fluoride-Silica Mixture for the Preparation of Porous Polymeric Membrane (다공성 분리막 제조를 위한 폴리플루오르화비닐리덴-실리카 혼합물의 열유도상분리 연구)

  • Kim, Se Jong;Lee, Jeong Woo;Nam, Sang Yong
    • Membrane Journal
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    • v.27 no.2
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    • pp.189-198
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    • 2017
  • In this study, we used thermally induced phase separation (TIPS) to produce water treatment membrane and poly(vinylidene fluoride) (PVDF), silica with excellent mechanical properties and chemical resistance to evaluate characterization of the membrane. The diluents used for the characterization were dioctyl phthalate (DOP) and dibutyl phthalate (DBP). We observed the crystallization temperature, cloud point and SEM images to see the manufacture conditions according to the ratio of PVDF and silica. The crystallization temperature and cloud point increased with the contents of silica. Through the phase diagram drawn from these results, the conditions for the preparation of the membrane confirmed.

Thermodynamic Comparison of Silicon Carbide CVD Process between CH3SiCl3-H2 and C3H8-SiCl4-H2 Systems (탄화규소 CVD 공정에서 CH3SiCl3-H2과 C3H8-SiCl4-H2계의 열역학적 비교)

  • Choi, Kyoon;Kim, Jun-Woo
    • Korean Journal of Metals and Materials
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    • v.50 no.8
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    • pp.569-573
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    • 2012
  • In order to understand the difference in SiC deposition between the $CH_3SiCl_3-H_2$ and $C_3H_8-SiCl_4-H_2$ systems, we calculate the phase stability among ${\beta}$-SiC, graphite and silicon. We constructed the phase-diagram of ${\beta}$-SiC over graphite and silicon via computational thermodynamic calculation considering pressure (P), temperature (T) and gas composition (C) as variables. Both P-T-C diagrams showed a very steep phase boundary between the SiC+C and SiC region perpendicular to the H/Si axis, and also showed an SiC+Si region with a H/Si value of up to 6700 in the $C_3H_8-SiCl_4-H_2$, and 5000 in the $CH_3SiCl_3-H_2$ system. This difference in phase boundaries is explained by the ratio of Cl to Si, which is 4 for the $C_3H_8-SiCl_4-H_2$ system and 3 for the $C_3H_8-SiCl_4-H_2$ system. Because the C/Si ratio is fixed at 1 in the $CH_3SiCl_3-H_2$ system while it can be variable in the $C_3H_8-SiCl_4-H_2$ system, the functionally graded material is applicable for better mechanical bonding during SiC coating on graphite substrate in the $C_3H_8-SiCl_4-H_2$ system.