• Bulletin of the Korean Chemical Society
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• 제22권11호
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• pp.1248-1254
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• 2001

The conformations and energies of p-tert-butylcalix[4]crown-6-ether (1) and its alkyl ammonium complexes have been calculated by ab initio HF/6-31G quantum mechanics method. The cone conformation was found to be most stable for free host 1. We hav e determined the binding site of these host-guest complexes focusing on the crown-6-ether or p-tert-butylcalix[4]arene pocket of the cone conformation of host molecule 1. The primary binding site of host 1 for the recognition of alkyl ammonium guests was confirmed to be the central part of the crown moiety of cone conformation. The complexation energy calculations revealed that the ammonium cation without alkyl group showed the highest complexation efficiency when combined with host 1, that is in satisfactory agreement with the experimental results.

• Bulletin of the Korean Chemical Society
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• 제12권6호
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• pp.629-632
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• 1991

The rate constants for the formation and dissociation of nickel(II) and cobalt(II) complexes with mandelate have been determined by the pressure-jump relaxation study. The forward and reverse rate constants for the mandelate complex formation reactions were obtained to be $k_f=3.60{\times}10^4\;M^{-1}s^{-1}$ and $k_r=1.73{\times}10^2\;s^{-1}$ for the nickel(II), and $k_f=1.75{\times}10^5\;M^{-1}s{-1}$ and $2.33{\times}10^3\;s^{-1}$ for the cobalt(II) in aqueous solution of zero ionic strength ($(\mu{\to}0)\;at\;25^{\circ}C$. The results were interpreted by the use of the multistep complex formation mechanism. The rate constants evaluated for each individual steps in the multistep mechanism draw a conclusion that the rate of the reaction would be controlled by the chelate ring closure step in concert with the solvent exchange step in the nickel(II) complexation, while solely by the chelate ring closure step for the cobalt(II) complex.

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3448-3450
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• 2012

• 대한화학회지
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• 제50권6호
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• pp.515-517
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• 2006

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.1018-1018
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• 2005

• Macromolecular Research
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• 제13권5호
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• pp.460-462
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• 2005

• Bulletin of the Korean Chemical Society
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• 제30권6호
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• pp.1401-1404
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• 2009

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2018년도 추계학술논문요약집
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• pp.588-589
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• 2018

• Bulletin of the Korean Chemical Society
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• 제33권3호
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• pp.790-794
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• 2012

Trace metal ions such as $Cd^{2+}$, $Ni^{2+}$, and $Zn^{2+}$ in a highly saline sample were subjected to on-line complexation with 4-(2-thiazolylazo) resorcinol (TAR) dissolved in a background electrolyte (BGE) under transient isotachophoresis (TITP) conditions. A long plug of the saline sample, containing the trace metal ions but devoid of TAR, was injected into a coated capillary filled with a BGE composed of 150 mM 2-(cyclohexylamino) ethanesulfonic acid (CHES) and 110 mM triethylamine (TEA) at pH 9.7. Since the electrophoretic mobility of TAR fell between the mobilities of the anionic leading electrolyte ($Cl^-$ in the sample) and the anionic terminating background electrolyte ($CHES^-$), a highly concentrated zone of TAR from the BGE was formed at the rear of the sample matrix and then the metal cations toward the cathode were swept by isotachophoretically assisted on-line complexation (IAOC) between the metal ions and the isotachophoretically stacked TAR. As a result, anionic metal-TAR complexes were formed efficiently, which satisfy the TITP conditions between $Cl^-$ and $CHES^-$. The enrichment factors of metal ions including $Cd^{2+}$ were up to 780-fold compared to a conventional CZE mode using absorbance detection. The detection limits were 17 nM, 15 nM, and 27 nM for $Ni^{2+}$, $Zn^{2+}$, and $Cd^{2+}$ in a 250 mM NaCl matrix, respectively. Our method was successfully applied to the analysis of urine samples without desalting.

• 한국실내디자인학회논문집
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• 제20권1호
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• pp.199-207
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• 2011

After the development of printing technology since the 15th century and the rise of citizen consciousness in the 18th century, the library has taken a public concept. And after the 20th century, its role as a public library for the public was stressed, and as its spatial composition became miniaturized and specialized, its function changed from stacking and reading to various kinds including culture and service and is getting more complex beside the function of a library. Thereupon, this study aims to figure out the limitations of public libraries' opening years shown in advanced researches and understand the current status of spatial composition by complexation with the subjects of five public libraries opened after the end of December, 2006 in order to examine their tendencies of complexation and the characteristics of spatial composition by the complexation of public libraries. As a result, the present public libraries have at leaser more than two spaces with complex functions. According to the result of analysis on the types, locational relations between spaces showed the mixed type the most. In the types of building allocation, the building integrated type had a higher percentage than the separated type. About the types of entrance, the one common door type was fewer than the two separate door type. In the analysis on the types of the interior line of flow, the common type was similar to the dispersed type, and it is thought to be resulted from spatial composition rather than the preplanned line of flow.