• Title/Summary/Keyword: hydrogen bonds

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Deterioration Mechanism of Paper According to Sizing and Beating (II) -Influences of Beating- (사이징과 고해에 따른 종이의 열화기구(제2보) -고해의 영향-)

  • 김봉용
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.31 no.2
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    • pp.58-63
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    • 1999
  • Three kinds of papers were prepared from different beating degree of pulps. Physical and optical properties were examined to elucidate the deterioration mechanism of paper according to beating degrees. Changes of double folds, elongation, water retention value, DP, K/S value and visible, UV region light absorption spectra of those papers treated by UV light were studied. Double folds and brightness were decreased more rapidly by UV treatment with increasing of beating degree. The light absorption rates of pulps in visible and UV region were also increased with change of beating level. The formation of new hydrogen bonds and higher light absorption rate of pulps according to beating induced to absorb and interact with much UV light. These phenomena maybe brought about to accelerate paper deteriortion by UV treatment both optical and physical properties.

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The Effects of Post-annealing on Laser CVD SiON Films (Laser CVD SiON막의 막 형성 후 열처리 의존성)

  • Kim, C.D.;Kim, I.S.;Koh, J.H.;Lee, S.K.;Sung, Y.K.
    • Proceedings of the KIEE Conference
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    • 1997.11a
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    • pp.336-338
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    • 1997
  • The anneal behavior of ArF excimer Laser CVD SiON films has been studied using FT-IR absorption spectroscopy. The anneal temperature range was $400{\sim}800^{\circ}C$ Abundant hydrogen effusion from thes layers was observed as anneal temperature increased. The coexistence of both Si-H am N-H bonds offers the possibility for cross linking am evidence for the occurrence of cross lingking was found in the IR spectrum. The electrical properties were also obtained that tire films have low leakage currents am good TZDB properties.

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A Study on Graphene Oxide and Carboxylated Styrene-Butadiene Rubber(XSBR) Nanocomposites (그래핀 옥사이드/카르복실화한 스티렌-부타디엔 고무 나노 복합체에 관한 연구)

  • Jang, Sun Ho;Xu, Li Xiang;Cho, Ur Ryong
    • Journal of the Semiconductor & Display Technology
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    • v.16 no.1
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    • pp.52-58
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    • 2017
  • Graphene oxide (GO)/carboxylated styrene-butadiene rubber (XSBR) nanocomposites with various contents of GO were prepared by a latex compounding method. It has been confirmed that the functional groups of GO and the hydrogen bonds between GO and XSBR are existed. It can be seen that the scorch time ($t_{s2}$), which is the measurement of incipient vulcanization of rubber, showed a delay after the addition of GO. Field emission scanning electron microscopy was employed to confirm the uniform dispersion of filler in the matrix. Indeed, with increasing fillers loading, the torque, tensile strength, thermal stability and crosslink density of obtained nanocomposites were improved. These results were correlated to the better dispersion of fillers through the rubber matrix.

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Functional Analysis of Protein Chip Plate Using Silane Carboxylate Surface (실란 카르복실 표면을 사용한 단백질 칩 기판의 기능 분석)

  • 김지현;송예신;윤미영;피재호
    • Journal of the Korean institute of surface engineering
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    • v.37 no.4
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    • pp.215-219
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    • 2004
  • We fabricated protein chip plates coated with silane carboxylate. The silane compound was immobilized by hydrogen bond and/or other chemical bonds on the surface of the plate. The plates were then prepared by binding $Ni^{2+}$ to surfaces terminated with silane carboxylate groups. The carboxylic acid surface was generated by chemical oxidation of the terminal double-bond functions of the silane-deposited layer. The $Ni^{2+}$ ions on the surface reacted readily to His-tagged proteins. A significant increase in His-tagged protein adsorption was achieved on the surface terminated with silane carboxylate with longer alkyl chain, suggesting better availability of these protein chip plates for proteomic studies.

The Crystal and Molecular Structure of 1-(Hexahydro-1H-azepin-1-yl)-3-(p-tolylsulfonyl) Urea: Tolazamide ($C_{14}H_{21}N_3O_3S$)

  • Koo, Chung-Hoe;Suh, Jung-Sun;Yeon, Young-Hee;Watanabe, Tokunosuke
    • Archives of Pharmacal Research
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    • v.11 no.1
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    • pp.74-79
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    • 1988
  • Crystals of tolazamide, $C_{14}H_{21}N_3O_3S$, are triclinic space group $P{\bar{1}}$ with cell dimensions of a = 6.355 (2), b = 9.223 (2), c = 13.510 (3) A, ${\alpha}\;=\;101.04\;(8),\;{\beta}=92.80(5),\;{\gamma}\;=\;85.72\;(6)^{\circ}$ and Z = 2. Intensities were collected on an automated four-circle diffractometer using graphite-monochromated Cu K ${\alpha}$ radiations. The structure was solved by direct method and refined by full-matrix least-squares to an R factor of 0.058 for 1184 observed reflections. The molecules are dimerized by the $N-H{\cdots}O$ hydrogen bonds. There are only van der Waals interactions between these molecular dimers.

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Analysis of the Structure-stability Relationship of Cold-adapted Lipase PsLip1 from Homology Modeling

  • Choo, Dong-Won
    • Genomics & Informatics
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    • v.9 no.2
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    • pp.79-84
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    • 2011
  • Two initial models of cold-adapted lipase PsLip1 have been constructed, based on homology with the bacterial lipases Chromobacterium viscosum (CvLip) and Pseudomonas cepacia (PcLip), whose X-ray structures have been solved and refined to high resolution. The mature polypeptide chains of these lipases have 84% similarity. The models of Mod1 and Mod2 have been compared with the tertiary structures of CvLip and PcLip, respectively, and analyzed in terms of stabilizing interactions. Several structural aspects that are believed to contribute to protein stability have been compared: the number of conserved salt bridges, aromatic interactions, hydrogen bonds, helix capping, and disulfide bridges. The 3-dimensional structural model of PsLip1 has been constructed in order to elucidate the structural reasons for the decreased thermostability of the enzyme in comparison with its mesophilic counterparts.

Construction of a 2D Co(II) Coordination Polymer with (4,4)-Connected Topology: Synthesis, Crystal Structure, and Surface Photo-electric Property

  • Li, Jia-Ming
    • Bulletin of the Korean Chemical Society
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    • v.35 no.4
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    • pp.1177-1181
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    • 2014
  • A 2D grid-like (4, 4)-connected topology coordination polymer, $[Co(BTA)_2(H_2O)_2]_n$ (1), where HBTA = 2-(1H-benzotriazol-1-yl)acetic acid, has been synthesized by hydrothermal method and characterized by single crystal X-ray diffraction, IR spectroscopy, elemental analysis and surface photovoltage spectroscopy (SPS). X-ray diffraction analyses indicated that 1 displays octahedral metal centers with secondary building units (SBUs) [$Co(BTA)_2(H_2O)_2$] bridged by the $BTA^-$ ligands. In the crystal, the 2D supramolecular architecture is further supported by $O-H{\cdots}O$, $O-H{\cdots}N$, $C-H{\cdots}O$ hydrogen bonds and ${\pi}{\cdots}{\pi}$ stacking interactions. The SPS of polymer 1 indicates that there are positive response bands in the range of 300-600 nm showing photo-electric conversion properties. There are good relationships between SPS and UV-Vis spectra.

Crystal Structure and Characterization of a New Eight Coordinated Cadmium Complex

  • Hakimi, Mohammad;Moeini, Keyvan;Mardani, Zahra;Khorrami, Farzaneh
    • Journal of the Korean Chemical Society
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    • v.57 no.3
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    • pp.352-356
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    • 2013
  • In this work, a new cadmium complex $[Cd(L)(CH_3COO)_2].2H_2O$ (1) with the ligand L, N,N'-bis(2-pyridinecarboxalidene)-1,2-cyclohexanediamine was prepared and identified by elemental analysis, FT-IR, Raman, $^1H$ NMR spectroscopy and single-crystal X-ray diffraction. The cadmium atom in the crystal structure of 1 has distorted triangular dodecahedral geometry by coordination of the four nitrogen atoms of L and four oxygen atoms of the two acetate ions. Two water molecules are also incorporated in the crystal network. The $O-H{\cdots}O$ hydrogen bonds present in the crystal structure of 1. In this work, three structural surveys including coordination numbers of the cadmium atom, coordination modes of L and resonance in pyridine-2-ylmethanimine-based compounds are presented.

The Crystal Structure of Tris(ethylenediamine)nickel(II)Chromate, $[Ni(C_2N_2H_8)_3]\cdotCrO_4$ ($[Ni(C_2N_2H_8)_3]\cdotCrO_4$의 결정구조)

  • Kim, Se-Hwan;Kim, Seung-Bin;Nam, Gung-Hae
    • Korean Journal of Crystallography
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    • v.6 no.2
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    • pp.75-79
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    • 1995
  • The crystal structure of Tris(ethylenediamine)nickel(II)Chromate has been determined by X-ray crystallography. Crystal data : a=9.027(2)Å, c=9.751(5)Å이며, Z=2, V=687.9(2)Å3, Dc=1.714gcm-3, μ=21.635-1. The intensity were collected with Mo-Kα radiation (λ=0.7107Å) on an automatic four-circle diffractometer with a graphite monochromator. The structure was solved by Patterson method and refined by full matrix least-square methods using unit weights. The final R and S values were R=0.029, Rw=032, Rall=0.049 andS=0.018 for 342 observed reflections. The chromate ions are located at position of point of point symmetry 32 and their oxygens are sixfold disodered in an unusual way. Extensive strong hydrogen bonds between complex cations and chromatic anions are found in axial and equatorial directions.

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The Crystal Structure of Tolfenamic Acid $(C_{14}H_{12}ClNO_2)$, an Antiinflammatory Fenamate

  • Kim, Yang-Bae;Chung, Uoo-Tae;Park, Il-Yeong
    • Archives of Pharmacal Research
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    • v.19 no.2
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    • pp.160-162
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    • 1996
  • The structural analysis of tolfenamic acid, 2-[(3-chloro-2-methylphenyl)-amino]benzoic acid, was performed by single crystal X-ray diffraction technique. The compound was recrystallized from a mixture of ether and toluene in triclinic, space group $P2_1/c, \;with\; \partial=3.914(1), \; b=22.\; 020(2), \; c=14.271(1)\;{\AA}, \beta.=94.68(1)^{\circ}, $ and Z=4. The calculated density is $1.418 g/cm^3$. The structure was solved by the direct method and refined by full matrix least-squares procedure to the final R value of 0.039 for 1773 independent reflections. In the molecule, carboxyl group at the anthranilic acid is coplanar to the phenyl ring. The dihedral angle between the two aromatic rings of the molecule is $44.2^{\circ}$ The molecules are dirnerized through the intermolecular hydrogen bonds at the carboxyl group in the crystal.

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