• Title/Summary/Keyword: 탈결합

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Electronic Structure and Chemical Bonding of La7Os4C9 (La7Os4C9의 전자구조와 화학결합)

  • Kang, Dae-Bok
    • Journal of the Korean Chemical Society
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    • v.53 no.3
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    • pp.266-271
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    • 2009
  • In the recently synthesized rare earth transition metal carbide $La_7O_{s4}C_9$ one finds one-dimensional organometallic $[O_{s4}C_9]^{21-}$ polymers embedded in a $La^{3+}$ ionic matrix. The electronic structure of the polymeric $[O_{s4}C_9]^{21-}$ chain was investigated by density of states (DOS) and crystal orbital overlap population (COOP), using the extended Huckel algorithm. A fragment molecular orbital analysis is used to study the bonding characteristics of the $C_2$ units in $La_7O_{s4}C_9$ containing $C_2$ units and single C atoms as well. The title compound contains partially filled Os and carbon bands leading to metallic conductivity. As the observed distances already indicated, the calculations show extensive Os-C interactions. The C-C bond distance in the diatomic $C_2$ units ($d_{C-C}$=131 pm) in the solid is significantly increased relative to $${C_2}^{2-}$$ or acetylene, because antibonding $1{\pi}_g$ orbitals are partially filled by the Os-$C_2(1\;{\pi}_g)$ bonding contribution found at and below the Fermi level.

A Study on the Architectural Environment as a Combination of Performance and Event (퍼포먼스.이벤트의 결합체로서 건축환경연구)

  • 김주미
    • Archives of design research
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    • v.14
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    • pp.121-138
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    • 1996
  • The purpose of this study is to develop a new architectural language and design strategies that would anticipate and incorporate new historical situations and new paradigms to understand the world. It consists of four sections as follows: First, it presents a new interpretation of space, human body, and movement that we find in modern art and tries to combine that new artistic insight with environmental design to provide a theoretical basis for performance-event architecture. Second, it conceives of architectural environment as a combination of space, movement, and probabilistic situations rather than a mere conglomeration of material. It also perceives the environment as a stage for performance and the act of designing as a performance. Third, in this context, man is conceived of as an organic system that responds to, interacts with, and adapts himself to his environment through self-regulation. By the same token, architecture should be a dynamic system that undergoes a constant transformation in its attempt to accommodate human actions and behaviors as he copes with the contemporary philosophy characterized by the principle of uncertainty, fast-changing society, and the new developments in technology. Fourth, the relativistic and organic view-point that constitutes the background for all this is radically different from the causalistic and mechanistic view that characterized the forms and functions of modernistic design. The present study places a great emphases on dematerialistic conception of environment and puts forth a disprogramming method that would accommodate interchangeability in the passage of time and the intertextuality of form and function. In the event, performance-event architecture is a strategy based on the systems world-view that would enable the recovery of man's autonomy and the reconception of his environment as an object of art.

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A Framework of Interpretating (de)Centralized Landscape : an Interaction of Power, Subjectivity, and Performativity ((탈)중심화 경관의 해석을 위한 틀 : 권력, 주체성, 수행성)

  • Park, Kyu-Taeg;Ha, Yong-Sam;Bae, Yoon-Gi
    • Journal of the Korean association of regional geographers
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    • v.16 no.4
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    • pp.355-368
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    • 2010
  • This study is to make a framework of newly interpretating the dynamic change of regional or local landscape rapidly occurred after the establishment of the nation state and capitalistic system. The basic concepts of making an interpretative framework are power, subjectivity, and performativity. The framework of closely interrelating the three concepts developed in the near future will be applied to the interpretation of variety of (de)centralized landscapes in regions or locals. A centralized political power under the nation state has destroyed or marginalized the historically developed landscapes, traditional culture, and subjects' values in regions or locals by the political implementation of the nation state, the establishment of national identity, a centralized economic development, and so on. The landscapes produced by the political power of the nation state can take a role as a cause of conflicts in regions or locals in terms of a historical perspective. Landscapes are being made by various subjects, and the produced landscapes also positively or negatively will influence the emotion, cognition, and behavior of the subjects particularly in a performative perspective. The dynamics interrelation between subjects and landscapes has been disguised or marginalized by reason/rationality, totality/collectivity, the separation between reason and emotion mainly made by modernism, the nation state, a capitalistic system. The interrelation between landscapes and subjects is especially emphasized on people's resistibility and creativity. Lastly, landscape is not a concept given as a priori or (re)presented objectively. It is not also a material or an object independently existed from a subject's emotion and cognition. It should be interpreted through a performative relation with subjects. Performativity will take an active role of combining the materiality of landscape, power, and subjectivity. It is also important to understand the active role of landscapes.

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Effective Chrome Removal Process from Shaving Dust (피혁분의 효율적인 탈 크롬 방법에 관한 연구)

  • Yun, Sun-Gyu;Park, Sung-Ha;Lee, Sang-Seob;Na, Jung-Won;Ko, Myung-Han
    • Applied Chemistry for Engineering
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    • v.10 no.8
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    • pp.1104-1108
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    • 1999
  • In this study it was focused that if the chrome could be removed in the shaving dust, the reusable protein resource could be recycled from the shaving dust. As the chrome forms a Cr-collagenate by cross linking of collagen in the shaving dust, the dust was steeped for swelling and plumping by $Ca(OH)_2$ solution and then chromium in dust was resolved out by $H_2SO_4$ solution in the first stage process. In the second stage one, dust was swelled and plumped by NaOH solution and then the chromium in dust was oxygenated to a hexavalent chrome, which has high solubility in $H_2O_2$ solution. And then the chromium was removed byt he steeping of $H_2SO_4$ solution as the last process. The first stage process was consisted of the sequential steeping of 3%-$Ca(OH)_2$ and $0.8%-H_2SO_4$. In the second stage the total chrome was effectively removed by the sequential steeping of 0.1%-NaOH, $3%-H_2O_2$ and $1%-H_2SO_4$. In the completely dechromated dust, the humidity was measured as 10.68% and the crude protein was contained by 79.81%. Steeping solutions were reused 3 times for chrome removal process, the chrome was entirely removed in shaving dust.

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Effects of Electrical Stimulation on the Mast Cell of Skin in Rats (전기자극이 흰쥐의 피부 비만세포에 미치는 영향)

  • Lee Jae-Hyoung;Jekal Seung-Joo;Park Seung-Teack
    • The Journal of Korean Physical Therapy
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    • v.11 no.3
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    • pp.81-87
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    • 1999
  • The purpose of this study was to determine the effect of electrical stimulation on the number of MCs and percent of degranulated MCs in rat skin. Twelve male Sprague-Dawley rats were divided into two group; electrical stimulation group (n=6) and control group (n=6). Each animals hair on the back was removed. The electrical stimulation group received an positive rectangular pulsed electrical stimulation, while the control group was given the same treatment without electricity. The biopsy specimens were fixed in formalin, embedded in paraffin and stained with toluidine blue-nuclear fast red and alcian blue-safranin O. respectively. The MCs were counted using a light microscope and computerized image analysis system and calculated as the density and the percent. A t-test showed a significantly higher density of MCs in the electrical stimulated rats than control rats(p<0.05), and the percent of degranulated MCs in the electrical stimulated rats was higher than in the control rats (p<0.05) in toluidine blue stained sections. The density of MCs was significantly higher in the electrical stimulated rats than the control rats in alcian blue-safranin O Stained sections (P<0.01). An analysis of variance showed that the densities of CTMCs was significantly lower than the densities of MMCs and mixed MCs in electrical stimulated rat in alcian blue-safranin O Stained sections (p<0.05). These results suggest that the electrical stimulation may have potential for increasing the number of MCs and lead to degranulate the MCs in rat skin.

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Space Structure Character of Hangeul Typography (한글 타이포그래피의 공간 구조적 특성)

  • Kim, Young-Kook;Park, Seong-Hyeon
    • The Journal of the Korea Contents Association
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    • v.8 no.3
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    • pp.86-96
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    • 2008
  • General development basis of letter system is recognized by formative value in terms of its function and structure. principle of clustered writing is the most significant feature of Hangeul typography as considered that it is based on function and formativeness. Thus, not only by changes with its form but also by its characteristic syllable combination, space structure is made as consonants and vowels are combined in single letter, then the combination develop into word, sentence, paragraph to make second, third space structure character. This character has significant impact on readability that is core function of typography. With this property, space structure character is regarded as very important component of Hangeul typography. First, space structure character of Hangeul typography is reviewed by relating it to visual perception of gestalt psychology and compared square-framed letter and framed latter By applying square-framed letter and framed latter in same sentence, legibility and readability were studied. Researcher has found that space structure character of Hangeul typography has significant impact on its function, and in terms of future design, it is very critical not only for design but also for communication environment as space structure formativeness of Hangeul typography interact with communication that is basic concept.

The Regulation Mechanisms of Kinesin Motor Proteins (Kinesin 모터 단백질의 조절 기전)

  • Park, Sang Jun;Seog, Joung-Su;Moon, Il Soo;Seog, Dae-Hyun
    • Journal of Life Science
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    • v.27 no.7
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    • pp.840-848
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    • 2017
  • Proper intracellular transport is essential for normal cell function. Intracellular transport is mediated by microtubule-dependent molecular motor proteins, as well as kinesin and cytoplasmic dynein, which move their cargo along long, microtubule tracks in cells. Kinesins are ATP-dependent plus-end-directed motor proteins in the intracellular transport of organelles, vesicles, RNA complexes, and protein complexes. The mislocalization of these different types of cargo has been linked to cell dysfunction and degeneration. The cargo transport of kinesins can be described by the following steps: binding to the appropriate cargo and/or adaptor proteins, activation of the kinesin's motility and movement along the microtubule, and the release of the cargo at the correct destination. Recently, several studies have revealed the mechanisms for the regulation of kinesin motor activity, including cargo loading and unloading. Intracellular cargo transport is also modulated by adaptor proteins, which link the kinesins to their cargo. The regulatory proteins, which include protein kinases and phosphatases, regulate kinesin motor activity directly through the phosphorylation or dephosphorylation of kinesins and indirectly through the modification of adaptor proteins, such as c-Jun NH-terminal kinase-interacting proteins, or of the microtubule network. These findings lay the groundwork for understanding how kinesins are differentially engaged in intracellular cargo transport. In addition, understanding the regulatory mechanisms of each kinesin is an area of key interest within cell biology and neurophysiology. In this study, we reviewed kinesins' regulation proteins and discuss how their regulation affects cargo recognition and transport.

Theoretical Studies on the Structure and Aromaticity of 1H-Indene and Mono-sila-1H-Indene (1H-Indene과 Mono-sila-1H-Indene의 구조와 방향족성에 대한 이론적 연구)

  • Ghiasi, Reza;Monnajemi, Majid
    • Journal of the Korean Chemical Society
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    • v.50 no.4
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    • pp.281-290
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    • 2006
  • The electronic structure and properties of the 1H-indene and mono-sila-1H-indene series have been investigated using basis set of 6-31G(d, p) and hybrid density functional theory. Basic measures of aromatic character derived from structure, molecular orbitals, a variety of magnetic criteria (magnetic isotropic and anisotropic susceptibilities) are considered. Energetic criteria suggest that In(Si7) enjoy conspicuous stabilization. However, by magnetic susceptibility isotropic this system are among the least aromatic of the family: Within their isomer series, In(Si4) is the most aromatic using this criteria. Natural bond orbital (NBO) analysis method was performed for the investigation of the relative stability and the nature of the 8-9 bonds in 1H-indene and mono-sila-1H-indene compounds. The results explained that how the p character of natural atomic hybrid orbital on X8 and X9 (central bond) is increased by the substitution of the C8 and C9 by Si. Actually, the results suggested that in these compounds, the X8-X9 bond lengths are closely controlled by the p character of these hybrid orbitals and also by the nature of C-Si bonds. The magnitude of the molecular stabilization energy associated to delocalization from X8-X9 and to * X8-X9 bond orbital were also quantitatively determined. Molecular orbital (MO) analysis further reveal that all structure has three delocalized MOs and two delocalized MOs and therefore exhibit the aromaticity.

Numerical Modeling of Hydrogen Embrittlement-induced Ductile Fracture Using a Gurson-Cohesive Model (GCM) and Hydrogen Diffusion (Gurson-Cohesive Model(GCM)과 수소 확산 모델을 결합한 수소 취화 파괴 해석 기법)

  • Jihyuk Park;Nam-Su Huh;Kyoungsoo Park
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.37 no.4
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    • pp.267-274
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    • 2024
  • Hydrogen embrittlement fracture poses a challenge in ensuring the structural integrity of materials exposed to hydrogen-rich environments. This study advances our comprehension of hydrogen-induced fracture through an integrated numerical modeling approach. In addition, it employs a ductile fracture model named the Gurson-cohesive model (GCM) and hydrogen diffusion analysis. GCM is employed as a fracture model that combines the Gurson model to illustrate the continuum damage evolution and the cohesive zone model to describe crack surface discontinuity and softening behavior. Moreover, porosity and stress triaxiality are considered as crack initiation criteria . A hydrogen diffusion analysis is also integrated with the GCM to account for hydrogen enhanced decohesion (HEDE) mechanisms and their subsequent impacts on crack initiation and propagation. This framework considers the influence of hydrogen on the softening behavior of the traction-separation relationship on the discontinuous crack surface. Parametric studies explore the sensitivity to diffusion properties and hydrogen-induced fracture properties. By combining numerical models of hydrogen diffusion and the ductile fracture model, this study provides an understanding of hydrogen-induced fracture and thereby contributes significantly to the ongoing efforts to design materials that are resilient to hydrogen embrittlement in practical engineering applications.

3D-QSAR Analyses on the Inhibition Activity of 4-Hydroxybenzyl alcohol Analogues Against Tyrosinase (4-Hydroxybenzyl alcohol 유도체들의 Tyrosinase 활성 저해에 대한 3D-QSAR 분석)

  • Kim, Sang Jin;Sung, Nack Do
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.39 no.4
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    • pp.329-335
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    • 2013
  • Three-dimensional quantitative structure-activity relationships (3D-QSARs) models between the substituents with changing groups ($R_1$ & $R_2$) of 4-hydroxybenzyl alcohol (4-HBA) derivatives as substrate molecule and their inhibitory activities against tyrosinase were derived and discussed quantitatively. The optimized CoMSIA FF model showed the best predictability and fitness ($r^2$ = 0.858 & $q^2$ = 0.951). The contour maps of the optimized CoMSIA FF model showed that, the inhibitory activities of the analogues against tyrosinase were expected to increase when hydrophobic (Hy) favor, negative charge (E) favor, steric (S) disfavor and hydrogen bond donor (HD) disfavor groups were substituted at the $R_2$ position. When the hydrogen bond donor (HD) favor groups were substituted at the $R_1$ position, it is predicted that the substituents will be able to increase the inhibitory activity.