• 제목/요약/키워드: Separation Behavior

검색결과 657건 처리시간 0.029초

Rich Phase Separation Behavior of Biomolecules

  • Shin, Yongdae
    • Molecules and Cells
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    • 제45권1호
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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.

폭발볼트의 구속환경에 따른 분리메커니즘 연구 (Study of Separation Mechanism According to the Constraint Condition of Explosive Bolts)

  • 정동희;이영우
    • 한국추진공학회지
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    • 제20권2호
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    • pp.67-74
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    • 2016
  • 폭발볼트는 고폭약를 사용하는 분리장치의 하나로서 폭발볼트의 내부에서 형성되는 폭압 및 충격파에 의해 분리된다. 이러한 메커니즘을 갖는 폭발볼트는 분리시 생성되는 충격파 및 파편형성 최소화되도록 설계되어야 할 것이다. 본 연구에서는 폭발볼트 및 볼트를 구속하는 구속물과의 거리(Air gap)을 변수로 두어 분리시험을 수행하였다. 이때 Air gap 따른 분리유무 및 분리 형상을 확인 하였고, 가속도 센서를 이용하여 구속물의 전달되는 Pyro-shock를 측정하였다. 또한 ANSYS Autodyn 프로그램을 이용하여 폭발볼트의 분리거동을 해석하였다. 실험 및 해석으로부터 폭발볼트와 구속물 사이의 Air gap 크기에 따른 폭발볼트의 분리거동에 미치는 영향을 확인하였고 특정 볼트에 한해서 최적의 폭발볼트의 구속환경을 설정하였다.

Effects of Surface Modification with Amino Terminated Polydimethylsiloxane(ATP) on the Corrosion Protection of Epoxy Coating

  • Shon, MinYoung
    • Corrosion Science and Technology
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    • 제8권3호
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    • pp.103-109
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    • 2009
  • An epoxy coating was designed to give a hydrophobic property on its surface by modifying it with three types of Amino Terminated Polydimethylsiloxane (ATP), and then effects of the modification on the structure, surface hydrophobic tendency, water transport behavior and hence corrosion protectiveness of the modified epoxy coating were examined using FT-IR spectroscopy, hydrothermal cyclic test, and impedance test. The surface of epoxy coating was changed from hydrophilic to hydrophobic property due primarily to a phase separation tendency between epoxy and modifier by the modification. The phase separation tendency is more appreciable when modified by ATP with higher molecular weight ATP at higher content. Water transport behavior of the modified epoxy coating decreased more in that with higher hydrophobic surface property. The resistance to localized corrosion of the modified epoxy coated carbon steel was well agreed with its water transport behavior and hydrophobic tendency.

강-콘크리트 계면파괴에 관한 비선형 유한요소해석 (Nonlinear Finite Element Analysis of Considering Interface Behaviors between Steel and Concrete)

  • 주영태;이용학
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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    • pp.105-108
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    • 2004
  • In general, the nonlinear behavior of composite structures composing of steel and concrete is analyzed on the basis of the assumption of the perfect bond actions in steel-concrete interface in which the interface slip or separation is not allowed. The assumption is based on the fact that the full interface bond behavior is provided with the mechanical connectors of studs. However, since the number and spacing of the studs are determined by the stress resultants calculated in the interface area, the interface analysis is required to evaluate the stress resultants. This paper describes the nonlinear steel-concrete interface behavior considering the two interface failure mechanisms of slip and separation. Elastoplastic constitutive relation is developed. thru the formulation framework using the two energy dissipation mechanisms. As the result, the steel plate push-out tests sandwitched between concrete blocks are analyzed and compared with the test results with which the good agreements are observed.

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의복 처분행동의 결정요인과 효과 (Exploring the Determinants of Clothing Disposition Behavior and their Effect)

  • 안수경
    • 한국의류학회지
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    • 제40권5호
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    • pp.879-893
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    • 2016
  • This study explores the determinants of clothing disposition and examines their effect on the dimensions of clothing disposition behavior. The data of 316 women were collected nationwide using an online self-administered questionnaire. This study initially identified five types of disposition behavior as revising, permanent separation, giving away, selling, and donating to charity. Exploratory and confirmative factor analysis identified the underlying determinants of clothing disposition as self-concept, reusability, economic factor, social environment, affective association, storage, fashionableness, and a sense of belongingness. Structural equation modeling was conducted to examine the relationships between variables. The results demonstrated that six out of eight determinants significantly affected clothing disposition behavior. The effects of social environment and a sense of belongingness were relatively strong determinants that influenced the four types of disposition behaviors. However, self-concept and affective association did not influence the disposition behaviors. A series of one-way MANOVA was conducted to determine the effect of the eight demographic variables on the four modes of clothing disposition. Giving away, permanent separation, and donating to charity differed significantly in the groups of three demographic variables such as age, monthly income, and marital status. This study empirically elucidates what criteria consumers use when confronted with unused clothing and how the determinants of clothing disposition influence the modes of clothing disposition behavior. This study provides a framework for clothing disposition behavior and its determinants as well as suggests a new approach to clothing disposition behavior and improvements in marketing decisions.

상분리 조절에 의한 PVDF막의 구조 변화 (Structural Changes of PVDF Membranes by Phase Separation Control)

  • 이세민;김성수
    • Korean Chemical Engineering Research
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    • 제54권1호
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    • pp.57-63
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    • 2016
  • Polyvinylidene fluoride (PVDF) 평막 제조를 위하여 PVDF의 용매와 희석제로서 n-methyl-2-pyrrolidone (NMP)와 dibutyl-phthlate (DBP)를 각각 사용하여 열유도 상분리(thermally induced phase separation, TIPS)와 비용매유도 상분리(nonsolvent induced phase separation, NIPS)를 동시에 유도하였다. NMP와 DBP를 PVDF와 용융 혼합할 경우 TIPS 공정에서의 결정화 온도가 낮아졌고 NIPS 공정에서의 불안정 영역이 확대되었다. 용매와 희석제의 비율에 따라 상분리 메카니즘이 변화하였고 이에 따라 다양한 구조의 막이 형성됨을 확인하였다. 또한 dope 용액과 비용매의 접촉여부에 따라 지배적인 상분리 거동이 결정되었다. 열전달이 물질전달에 비하여 빠르게 이루어지므로 막의 표면은 NIPS에 의하여 지배를 받고 막의 내부는 TIPS에 의한 구조가 형성되었다. 또한 dope 용액의 급냉온도에 따라 상분리 메카니즘 및 상분리 속도가 변화하여 다양한 구조를 형성하였다.

식물세포배양으로부터 파클리탁셀 및 이의 반합성 전구체 10-디아세틸파클리탁셀의 분리 양상 (Separation Behavior of Paclitaxel and Its Semi-synthetic Precursor 10-Deacetylpaclitaxel from Plant Cell Cultures)

  • 이충기;김진현
    • Korean Chemical Engineering Research
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    • 제54권1호
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    • pp.89-93
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    • 2016
  • 본 연구에서는 식물세포배양으로부터 항암물질 파클리탁셀 및 이의 반합성 전구체 10-디아세틸파클리탁셀의 분리 양상을 조사하였다. 식물세포인 바이오매스를 이용한 분리/정제 공정인 용매를 이용한 바이오매스 추출, 액-액 추출, 흡착제 처리, 헥산 침전, 분별 침전을 순차적으로 수행한 결과, 흡착제 처리 공정에서 10-디아세틸파클리탁셀는 파클리탁셀로부터 가장 효과적으로 분리됨을 알 수 있었다. 파클리탁셀 및 10-디아세틸파클리탁셀 분리에 적합한 흡착제 종류, 건조시료/흡착제 비율, 흡착제 처리 온도는 각각 실로퓨트, 1:1.5(w/w), $20^{\circ}C$ 이었다. 최적의 흡착제 처리 조건에서 10-디아세틸파클리탁셀은 74.1% 분리/회수 가능하였다.

신뢰성 있는 파이로테크닉 분리 너트 설계를 위한 진동 시 볼트 풀림 해석 (Bolt Loosening Analysis under Transverse Vibration for Design of Reliable Pyrotechnic Separation Nut)

  • 최재영;우정민;강다훈;김정호;조진연;장승교;양희원
    • 한국항공우주학회지
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    • 제46권12호
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    • pp.1004-1011
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    • 2018
  • 최근 우수한 충격 저감 효과로 인해 파이로테크닉 분리 장치의 한 종류인 저충격 파이로 테크닉 분리 너트에 많은 관심이 주어지고 있다. 하지만 파이로테크닉 분리 너트의 경우 일반 너트 대신 분할 너트가 사용되기 때문에 볼트 풀림 거동에 대한 연구가 충분히 이루어지지 않은 측면이 있다. 이에 본 연구에서는 Junker 진동시험을 준거삼아 볼트 풀림 해석을 수행하였다. 해석은 크게 두 단계로 이루어져 있다. 첫 번째 단계는 체결토크를 이용하여 볼트를 분리너트에 체결하는 과정이고, 두 번째 단계는 횡 방향 가진을 통해 볼트가 풀리는 과정이다. 이러한 과정을 통해 볼트 풀림 거동을 얻을 수 있었다. 또한 신뢰성 있는 파이로테크닉 분리 너트의 설계를 위해 체결부 틈새가 볼트 풀림 거동에 미치는 영향을 고찰하였다.

태양광 모듈 표면 온도 제어에 따른 백시트 박리 거동 (Peeling Behavior of Backsheet according to Surface Temperature of Photovoltaic Module)

  • 김정훈;이준규;안영수;여정구;이진석;강기환;조철희
    • 한국재료학회지
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    • 제29권11호
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    • pp.703-708
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    • 2019
  • In this study, we investigate the relationship between the peeling behavior of the backsheet of a photovoltaic(PV) module and its surface temperature in order facilitate removal of the backsheet from the PV module. At low temperatures, the backsheet does not peel off whereas, at high temperatures, part of the backsheet remains on the surface of the PV module after the peeling process. The backsheet material remaining on the surface of the PV module is confirmed by X-ray diffraction(XRD) analysis to be poly-ethylene(PE). Differential scanning calorimetry(DSC) is also performed to investigate the interfacial characteristics of the layers of the PV module. In particular, DSC provides the melting temperature($T_m$) of laminated ethylene vinyl acetate(EVA) and of the backsheet on the PV module. It is found that the backsheet does not peel off below the $T_m$ of ethylene of EVA, while the PE layer of the backsheet remains on the surface of the PV module above the $T_m$ of the PE. Thus, the backsheet is best removed at a temperature between the $T_m$ of ethylene and that of PE layer.