• Title/Summary/Keyword: structural rearrangement

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Synthesis of Nanocrystalline Ceria Powders for SOFC Electrolyte (SOFC 전해질 제조를 위한 나노결정 세리아 분말의 합성)

  • Kim, Jin-Soo;Kwon, Byeong-Wan;Park, Jun-Sung
    • 한국신재생에너지학회:학술대회논문집
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    • 2005.11a
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    • pp.656-659
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    • 2005
  • Nanocrystalline ceria powders were prepared by hydrothermal treatment of cerium(IV) ammonium nitrate solution without a precipitating agent. A systematic investigation of the effect of hydrothermal temperature and react ion time on the physical properties of the product powders was carried out. When the hydrothermal temperature was increased, the product ceria powders exhibited larger crystallite size with higher yield. Increasing reaction time produced more crystalline ceria powders attributed to further hydrothermal reactions and structural rearrangement. The physical properties of ceria powders can be control led by adjusting the hydrothermal conditions.

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Structural and Molar Mass Characterization of Commercial Aliphatic Hyperbranched Polyesters

  • Zager, Ema;Huskic, Miroslav;Zigon, Majda
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.114-115
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    • 2006
  • We investigated the effects of annealing on the rearrangement of H-bonding structure and its influence on the thermal and rheological properties of $2^{nd}\;and\;4^{th}$ pseudo-generation aliphatic hyperbranched (HB) polyesters based on 2,2-bis(methylol)propionic acid. During annealing of amorphous HB polyesters, the structure becomes more ordered as a consequence of multiple H-bonds formation between linear sequences. Structure ordering is more pronounced for the lower pseudo-generation HB polyester with low molar mass, low degree of branching and incompletely reacted core hydroxyl groups which greatly increases the possibility for multiple H-bond interactions.

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INFLUENCE OF HUMIC SUBSTANCE (HS) ADSORPTIVE FRACTIONATION ON PYRENE PARTITIONING TO DISSOLVED AND MINERAL-ASSOCIATED HS

  • Hur, Jin;Schlautman, Mark A.
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2003.09a
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    • pp.123-127
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    • 2003
  • Changes in pyrene partitioning due to mineral surface adsorptive fractionation processes of humic substances (HS) were examined in model environmental systems. For purified Aldrich humic acid(PAHA), carbon-normalized pyrene binding coefficients ( $K_{oc}$ ) for the residual (i.e., nonadsorbed and dissolved) PAHA components were different from the original dissolved PAHA $K_{oc}$ , value prior to contact with mineral suspensions. A positive correlation between the extent of pyrene binding and weight-average molecular weight (M $W_{w}$) of residual PAHA components was observed, which appeared to be unaffected by the specific mineral adsorbents use and fractionation mechanisms. A similar positive correlation was not observed with the adsorbed PAHA components, suggesting that conformational changes occurred for the mineral-associated components upon adsorption. Nonlinear pyrene sorption to mineral-associated PAHA was observed, and the degree of nonlinearity is hypothesized to be dependent on adsorptive fractionation effects and/or structural rearrangement of the adsorbed PAHA components.s.

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CRYSTAL STRUCTURE OF AN UNCLEAVED $\alpha_1$-ANTITRYPSIN WITH SEVEN STABILIZING MUTATIONS AT 2.7 $\{AA}$ RESOLUTION

  • Ryu, Seong-Eon;Park, Hee-Jeong;Kwon, Ki-Sun;Lee, Kee-Nyung;Yu, Myung-Hee
    • Proceedings of the Korean Biophysical Society Conference
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    • 1996.07a
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    • pp.4-4
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    • 1996
  • $\alpha$$_1$-arantitrypsin, a member of the serpin (serine protease inhibitor) family, undergoes a large structural rearrangement upon the cleavage and insertion of the reactive site loop. This conformational change is driven by the metastability of the native serpin structures and has an important role in the regulation of the inhibitory-serpin function. (omitted)

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Investigation of adsorption structure for methionine on Ge(100)

  • Yang, Se-Na;Yun, Yeong-Sang;Park, Seon-Min;Hwang, Han-Na;Hwang, Chan-Guk;Kim, Se-Hun;Lee, Han-Gil
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.369-369
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    • 2010
  • Adsorption and ordering of methionine molecules on Ge(100) surface have been studied using high resolution photoemission spectroscopy and low-energy electron diffraction (LEED) to investigate the adsorption structure as a function of coverage. Analysis of C 1s, S 2p, N 1s, and O 1s core levels reveals quite different according to methionine coverage. We found that the relative population of the two types of thiolates induces a structural change in the ordering from $2\;{\times}\;1$ to $1\;{\times}\;1$. Such an unusual evolution of the methionine adsorption on the Ge(100) surface is discussed in relation to chemical reactions and possible molecular rearrangement on the surface.

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New optimum distribution of lateral strength of shear-type buildings for uniform damage

  • Donaire-Avila, Jesus;Lucchini, Andrea;Benavent-Climent, Amadeo;Mollaioli, Fabrizio
    • Structural Engineering and Mechanics
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    • v.76 no.3
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    • pp.279-291
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    • 2020
  • The seismic design of conventional frame structures is meant to enhance plastic deformations at beam ends and prevent yielding in columns. To this end, columns are made stronger than beams. Yet yielding in columns cannot be avoided with the column-to-beam strength ratios (about 1.3) prescribed by seismic codes. Preventing plastic deformations in columns calls for ratios close to 4, which is not feasible for economic reasons. Furthermore, material properties and the rearrangement of geometric shapes inevitably make the distribution of damage among stories uneven. Damage in the i-th story can be characterized as the accumulated plastic strain energy (Wpi) normalized by the product of the story shear force (Qyi) and drift (δyi) at yielding. Past studies showed that the distribution of the plastic strain energy dissipation demand, Wpi/ΣWpj, can be evaluated from the deviation of Qyi with respect to an "optimum value" that would make the ratio Wpi/(Qyiδyi) -i.e. the damage- equal in all stories. This paper investigates how the soil type and ductility demand affect the optimum lateral strength distribution. New optimum lateral strength distributions are put forth and compared with others proposed in the literature.

Typology as Form Generating Process in Contemporary Architecture (현대건축 형태생성 과정으로써의 유형학적 특성)

  • Kim, Jong-Myeong;Kim, Dong-Jin
    • Korean Institute of Interior Design Journal
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    • v.23 no.5
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    • pp.3-13
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    • 2014
  • Typology in Contemporary Architecture wants to escape from the classical typology that has the problems about specific program of structuralism, typical repeatation of customary form. As visible and non-visible things are appeared in contemporary architecture through the analysis of the inner system involving development process of changing itself, typology of contemporary is utilized at a tool of form generation in the process of architect. And it notes that the structural properties of the building system. The form of contemporary architecture has the new connecting strucure not reduced to existing ones. It carries out generative access as a device in order to solve the complexity of society. From this perspective, we analyze the process of projects of contemporary architects that can be typological strategy not representation of post geometric form but a tool of form generation in architectural process. As a result, we can find four characteristics of typology as a tool of form generation; 'interference and mix of program', 'continous slabs', 'rearrangement through relationship setting', 'transformation of multi-layers'. These are expanding to the process that reflect history and context or infer from morphology. Therefore, typology as architectural process of form generation overcomes morphological typology of classical typology and suggests that the different architectural approach having potential possibility.

Cytogenetic Analysis of Four Hosta Species Native to Korea

  • Kim, Hyun-Hee;Park, Young-Wook;Yoon, Pyung-Sub;Choi, Hae-Woon;Bang, Jae-Wook
    • Korean Journal of Medicinal Crop Science
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    • v.12 no.5
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    • pp.397-400
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    • 2004
  • The chromosome numbers and karyotypes were investigated in four Korean native species of the genus Hosta. The chromosome complements were diploid of 2n=60 in H. japonica var. lancifolia Nakai and H. capitata Nakai, aneuploid of 2n=59 in H. minor (Bak.) Nakai, and modified triploid of 2n=92 in H. longipes (Fr. et Sav.) Matsumura. All the species carried four sets of distinctly large chromosomes of which the chromosome types were telocentrics or subtelocentrics with $4.4{\sim}7.2\;{\mu}m$ in length. The other chromosomes were meta-, submeta, subtelo-, or telocentric types and showed gradual length degradation in the range of $1.0{\sim}3.0\;{\mu}m$. The satellites appeared vestigially in a pair or a triplet set of chromosomes which depends on the species. New chromosome number and karyotype in H. longipes were the first report in this species. The structural rearrangement was suggested to explain the modified triploid composition of 2n=92.

Effect of Cyclic Drying-Wetting on Compressive Strength of Decomposed Granite Soils (습윤-건조 반복작용으로 인한 화강풍화토의 압축강도 특성 변화 연구)

  • Yoo, Chung-Sik
    • Journal of the Korean Geosynthetics Society
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    • v.10 no.4
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    • pp.19-28
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    • 2011
  • This paper presents the results of an investigation into the effect of cyclic wetting-drying on the compressive strength characteristics of decomposed granite soils. A series of plane strain compression (PSC) tests were performed on test specimens with varying fine contents under different wetting-drying cycles to investigate the change in compressive strength under the process of wetting-drying cycles. The effect of wetting-drying cycles on the structural particle rearrangement at a micro-scale level was also examined using scanning electron microscope (SEM) tests. It was shown that the soil containing larger fines showed more significant decrease in compressive strength compared with the soils with less fines. Also found was that the wetting-drying cycle did not have significant effect on the particle arrangement.

A Study for the Improvement of Top End Piece Structural Strength (상단고정체의 구조강도 개선을 위한 연구)

  • Song, Kee-Nam;Sohn, Dong-Seong
    • Nuclear Engineering and Technology
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    • v.21 no.3
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    • pp.186-192
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    • 1989
  • As a part of the design of the top end piece(TEP) for the 14$\times$14 reload fuel, various models of top end piece structure were analysed, using the ANSYS code, under fuel assembly shipping and handling load conditions. The 3-dimensional isoparametric elements were used in each model. By rearrangement of slots and holes on the adapter plate, without violating the design requirements, and also by changing the enclosure attachment method used on the adapter plate from pin joints to through-weld, the load carving capacity of the adapter plate was greatly strengthened. These concepts were adopted for the design of the 14$\times$14 reload fuel.

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