• 제목/요약/키워드: coexistence state

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미국 동기관계연구의 최근동향 - 기본인식과 접근방법- (Current States of Sibling Researches in America)

  • 박영애
    • 가정과삶의질연구
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    • 제8권2호
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    • pp.147-162
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    • 1990
  • The purpose of this review is to establish a groundwork for building a more comprehensive conceptual framework within which various aspects of sibling relations and factor related to sibling behaviors con be explained and integrated. Descriptions of the trends and shifts in sibling studies are made in terms of their themes, variables, basic perceptions and general approaches, and analyzes of current state of sibling researches are made with relation to the conceptual aspects of the studies, namely, their standpoints on the issues of sibling variations, the sources of variations, and basic units of analysis, their reliance or emphasis on different methods, and their interests in the mediation processes. It is recognized that research variables have been successively differentiated and used in diversified manners and family ecology and systems theory viewpoints have been incorporated into the understanding of sibling relations. A triad in its full meaning, rather than a dyad or a partial trial, is proposed as a unit of analysis in order for the researchers to be able to examine and describe the true interactional aspects of family relations involving sibling relations. The concepts of coexistence and interaction are proposed as key concepts os that the inconsistencies in findings, differing viewpoints, contradicting conceptions , and contrasting approaches can be interpreted and integrated into a unified system of theories on siblings. The coexistence of similarities and differences in reality. the inevitability of interaction between individual variables and environmental variables and between within-family environmental factors and our-of-family environmental factors, and the need for the joint use of intrafamilial and extrafamilial approach are acknowledged. Attention is also drawn to the mechanism characteristics and the directionality of the mediating processes of mediating variables between a variable and its effects.

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NMR for magnetite

  • Lee, Soonchil
    • 한국자기공명학회논문지
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    • 제22권4호
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    • pp.101-106
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    • 2018
  • Magnetite is the oldest magnet material known to mankind. It is getting attention again from solid state physics researchers now a days because it is one of the most strongly correlated electron systems. Spin, charge, and orbital orders are interplaying with lattice and involved in the Verwey transition where magnetization, conductivity, and structure changes suddenly. The peculiar ordering states above and below the transition temperature mainly originate from the coexistence of $Fe^{2+}$ and $Fe^{3+}$ ions in the B site of the inverse spinel structure. In particular, the state of the charge and orbital order was the oldest and most intriguing problem. NMR has made significant contribution to the investigation of this question. A. Abragam stated that there is no doubt that NMR is a very powerful tool for the study of ferromagnetic and antiferromagnetic materials. In this mini-review, a short history of NMR investigation of magnetite is presented, providing a support to Abragam's claim.

SWR as Tool for Determination of the Surface Magnetic Anisotropy Energy Constant

  • Maksymowicz, L.J.;Lubecka, M.;Jablonski, R.
    • Journal of Magnetics
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    • 제3권4호
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    • pp.105-111
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    • 1998
  • The low energy excitations of spin waves (SWR) in thin films can be used for determination of the surface anisotropy constant and the nonhomogeneities of magnetization in the close-to-surface layer. The dispersion relation in SWR is sensitive on the geometry of experiment. We report on temperature dependence of surface magnetic anisotropy energy constant in magnetic semiconductor thin films of$ CdCr_{2-2x}In_{2x}Se_4$ at spin glass state. Samples were deposited by rf sputtering technique on Corning glass substrate in controlled temperature conditions. Coexistence of the infinite ferromagnetic network (IFN) and finite spin slusters (FSC) in spin glass state (SG) is know phenomena. Some behavior typical for long range magnetic ordering is expected in samples at SG state. The spin wave resonance experiment (microwave spectrometer at X-band) with excited surface modes was applied to describe the energy state of surface spins. We determined the surface magnetic anisotropy energy constant versus temperature using the surface inhomogeneities model of magnetic thin films. It was found that two components contribute to the surface magnetic anisotropy energy. One originates from the exchange interaction term due to the lack of translation symmetry for surface spin as well as from the originates from the exchange interaction term due to the lack of translation symmetry for surface spin as well as from the stray field of the surface roughness. The second one comes from the demagnetizing field of close-to surface layer with grad M. Both term linearly decrease when temperature is increased from 5 to 123 K, but dominant contribution is from the first component.

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다문화사회와 지구.지방적 시민성: 일본의 다문화공생 개념과 관련하여 (Multiculturalism and Glocal Citizenship: In Reference to Japanese Concept of 'Multicultural Coexistence')

  • 최병두
    • 한국지역지리학회지
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    • 제17권2호
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    • pp.181-203
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    • 2011
  • 다문화사회로의 전환은 국민국가에 근거한 국가적 시민성의 개념에서 벗어나 새로운 시민성에 관한 논의를 요구하고 있다. 시민성은 개인이나 공동체 간의 관련성으로 정의되며, 또한 정체성의 개념과 상호 관련적인 것으로 이해된다. 뿐만 아니라 시민성의 개념에는 다양한 공간적 요소들, 즉 위치/이동, 장소 및 공적/사적 공간, 경계/영토, 흐름/네트워크, 층위/규모 등이 포함되어 있으며, 특히 지방적, 국가적, 지구적 층위의 다규모성을 내재하고 있다. 다문화 사회로 전환하고 있는 일본에서도 시민성에 관한 논의가 새롭게 전개되고 있다. 특히 외국인 이주자의 국가-영토적 시민성을 철저히 통제하고자 하는 중앙정부와는 달리, 지역사회 생활공간에서 이들의 복지서비스 지원과 권리 보장을 담당하는 지방정부와 지역사회단체들의 역할을 강조하기 위하여 국지적 시민성의 개념이 강조되고 있다. 그러나 이 개념은 국지적 시민성을 실질적인 것으로 간주하고 국가적 형식적 시민성 및 지구적 보편적 시민성으로부터 분리시키는 문제를 안고 있다. 이 문제의 해소를 위해, 지방적, 국가적, 지구적 시민성이 상호관련적으로 연계된 다규모적 지구 지방적 시민성의 개념을 제시한다. 지구 지방적 시민성의 개념은 학문적으로 보편성과 특수성을 변증법적으로 포용하는 세계시민주의의 새로운 견해를 가능하게 하며, 또한 현실적으로 일본의 다문화공생 정책과 담론 그리고 국지적 시민성에 관한 논의에 내재된 문제들을 해소하기 위한 방안이 될 수 있다.

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Effect of Cholesterol on the Phase Change of Lipid Membranes by Antimicrobial Peptides

  • Choi, Hyungkeun;Kim, Chul
    • Bulletin of the Korean Chemical Society
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    • 제35권5호
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    • pp.1317-1322
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    • 2014
  • Membrane disruption by an antimicrobial peptide (AMP) was investigated by measuring the $^2H$ solid-state nuclear magnetic resonance spectra of 1-palmitoyl-$d_{31}$-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC_$d_{31}$) in mixtures of POPC_$d_{31}$/cholesterol and either magainin 2 or aurein 3.3 deposited on thin cover-glass plates. The line shapes of the experimental $^2H$ solid-state nuclear magnetic resonance (SSNMR) spectra were best simulated by assuming the coexistence of a mosaic spread of bilayers containing pore structures and a fasttumbling isotropic phase or a hexagonal phase. Within a few days of incubation in a hydration chamber, an isotropic phase and a pore structure were induced by magainin 2, while in case of aurein 3.3 only an isotopic phase was induced in the presence of a bilayer phase. After an incubation period of over 100 days, alignment of the bilayers increased and the amount of the pore structure decreased in case of magainin 2. In contrast with magainin 2, aurein 3.3 induced a hexagonal phase at the peptide-to-lipid ratio of 1/20 and, interestingly, cholesterol was not found in the hexagonal phase induced by aurein 3.3. The experimental results indicate that magainin 2 is more effective in disrupting lipid bilayers containing cholesterol than aurein 3.3.

Magnetic Semiconductors Thin Films-Unidirectional Anisotropy

  • Lubecka, M.;Maksymowicz, L.J.;Szymczak, R.;Powroznik, W.
    • Journal of Magnetics
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    • 제4권1호
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    • pp.33-37
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    • 1999
  • Unidirectional magnetic anisotropy field ($H_an$) was investigated for thin films of $CdCr{2-2x}In_{2X}Se_4 (0$\leq$x$\leq$0.2). This anisotropy originates from the microscopic anisotropic Dzyaloshinskii-Moriya (DM) interaction which arise from the spin-orbit scattering of the conduction electrons by the nonmagnetic impurities. This interaction maintains the remanent magnetization in the direction of the initial applied field. Then the single easy direction of the magnetization is parallel to the direction of the magnetic field. The anisotropy produced by field cooling is unidirectional I.e. the spins system deeps some memory of the cooling field direction. The chalcogenide spinel of$ CdCr_{2-2x}In){2X}Se_4$belongs to the class of the magnetic semiconductors. The magnetic disordered state is obtained when ferromagnetic structure is diluted by In. Then we have the mixed phase characterised by coexistence the magnetic long range ordering (IFN-infinite ferromagnetic network) and the spin glass order (Fc-finite clusters). The total magnetic anisotropy energy depends on the state of magnetic ordering. In our study we concentrated on the magnetic state with reentrant transition and spin glass state. The polycrystalline $ CdCr_{2-2x}In){2X}Se_4$ thin films were obtained by rf sputtering technique. We applied the ferromagnetic resonance (FMR) and M-H loop techniques for determining the temperature composition dependencies of Han. From the experimental data, we have found that Han decreases almost linearly when temperature is increased and in the low temperature is about three times bigger at SG state with comparison to the state with REE.

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도농공존거점공간으로의 폐교 활용방안 및 활성화 요인 분석 (Analysis of Closed School Utilization and Activation Factors as Urban-Rural Base Space)

  • 구희동;배승종;김대식
    • 농촌계획
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    • 제28권3호
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    • pp.95-109
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    • 2022
  • This study attempted to suggest the factors that facilities that aim to exchange urban-rural coexistence base spaces with urban-rural areas should have. In order to derive factors, 15 literatures preceded by similar studies were investigated, and systematic classification was attempted. Finally, the factors for activating urban and rural base facilities were organized into 3 categories, 9 sectors, and 30 activation factors. The three major categories consisted of resources and facilities, content and programs, operational status. As a result of the AHP survey, in the survey area, which is a categories, resources and facilities composed of hardware factors originally possessed by the facility showed the highest score of 48.9. In the sectors, the convenience of facility use was 25.7 points, and the rich state of tangible and intangible resources was 13.3 points in order. In the sectors, income from paid experience programs at facilities was 8.3 points, physical accessibility to facilities was 8.2 points, and the type of areas where the facilities were located was 7.7 points in order. It showed high importance in the order of resources and facilities composed of hardware factors, content and programs composed of software factors, and manpower and operation composed of humanware factors. In general, it was shown that the physical factors of the place when using urban and rural base facilities were judged as the main factors.

An NMR Study on the Phase Change of Lipid Membranes by an Antimicrobial Peptide, Protegrin-1

  • Kim, Chul
    • Bulletin of the Korean Chemical Society
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    • 제31권2호
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    • pp.372-378
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    • 2010
  • Membrane disruption by an antimicrobial peptide, protegrin-1 (PG-1), was investigated by measuring the $^2H$ solid-state nuclear magnetic resonance (SSNMR) spectra of 1-palmitoyl-$d_{31}$-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC_$d_{31}$) in the mixture of PG-1 and POPC_$d_{31}$ lipids deposited on thin cover-glass plates. The experimental line shapes of anisotropic $^2H$ SSNMR spectra measured at various peptide-to-lipid (P/L) ratios were simulated reasonably by assuming the mosaic spread of bilayers containing pore structures or the coexistence of the mosaic spread of bilayers and a fast-tumbling isotropic phase. Within a few days of incubation in the hydration chamber, the pores were formed by the peptide in the POPC_$d_{31}$ and POPC_$d_{31}$/cholesterol membranes. However, the formation of the pores was not clear in the POPC_$d_{31}$/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylglycerol (POPG) membrane. Over a hundred days after hydration, a rapidly rotating isotropic phase increased in the POPC_$d_{31}$ and the POPC_$d_{31}$/cholesterol membranes with the higher P/L ratios, but no isotropic phase appeared in the POPC_$d_{31}$/POPG membrane. Cholesterol added in the POPC bilayer acted as a stabilizer of the pore structure and suppressed the formation of a fast-tumbling isotropic phase.

Numerical result of complex quick time behavior of viscoelastic fluids in flow domains with traction boundaries

  • Kwon, Young-Don
    • Korea-Australia Rheology Journal
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    • 제19권4호
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    • pp.211-219
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    • 2007
  • Here we demonstrate complex transient behavior of viscoelastic liquid described numerically with the Leonov model in straight and contraction channel flow domains. Finite element and implicit Euler time integration methods are employed for spatial discretization and time marching. In order to stabilize the computational procedure, the tensor-logarithmic formulation of the constitutive equation with SUPG and DEVSS algorithms is implemented. For completeness of numerical formulation, the so called traction boundaries are assigned for flow inlet and outlet boundaries. At the inlet, finite traction force in the flow direction with stress free condition is allocated whereas the traction free boundary is assigned at the outlet. The numerical result has illustrated severe forward-backward fluctuations of overall flow rate in inertial straight channel flow ultimately followed by steady state of forward flow. When the flow reversal occurs, the flow patterns exhibit quite complicated time variation of streamlines. In the inertialess flow, it takes much more time to reach the steady state in the contraction flow than in the straight pipe flow. Even in the inertialess case during startup contraction flow, quite distinctly altering flow patterns with the lapse of time have been observed such as appearing and vanishing of lip vortices, coexistence of multiple vortices at the contraction comer and their merging into one.

Preparation and Field-Induced Electrical Properties of Perovskite Relaxor Ferroelectrics

  • Fan, Huiqing;Peng, Biaolin;Zhang, Qi
    • Transactions on Electrical and Electronic Materials
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    • 제16권1호
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    • pp.1-4
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    • 2015
  • (111)-oriented and random oriented $Pb_{0.8}Ba_{0.2}ZrO_3$ (PBZ) perovskite relaxor ferroelectric thin films were fabricated on Pt(111)/$TiO_x$/$SiO_2$/Si substrate by sol-gel method. Nano-scaled antiferroelectric and ferroelectric two-phase coexisted in both (111)-oriented and random oriented PBZ thin film. High dielectric tunability (${\eta}=75%$, E = 560 kV/cm) and figure-of-merit (FOM ~ 236) at room temperature was obtained in (111)-oriented thin film. Meanwhile, giant electrocaloric effect (ECE) (${\Delta}T=45.3K$ and ${\Delta}S=46.9JK^{-1}kg^{-1}$ at $598kVcm^{-1}$) at room temperature (290 K), rather than at its Curie temperature (408 K), was observed in random oriented $Pb_{0.8}Ba_{0.2}ZrO_3$ (PBZ) thin film, which makes it a promising material for the application to cooling systems near room temperature. The giant ECE as well as high dielectric tunability are attributed to the coexistence of AFE and FE phases and field-induced nano-scaled AFE to FE phase transition.