• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.4
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• pp.693-699
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• 2010

General transformer's life is known as paper insulation' life. If a transformer is degraded by these aging factors, it is known that electrical, mechanical and chemical characteristics for transformer's oil-paper are changed. When the kraft paper is aged, the cellulose polymer chains break down into shorter lengths. It causes decrease in both tensile strength and degree of polymerization of paper insulation. The paper breakdown is accompanied by an increase in the content of furanic compounds within the dielectric liquid. In this paper it is aimed at analysis on correlation between aging characteristics for insulating diagnosis of thermally aged paper. For investigating the accelerated aging process of oil-paper samples accelerating aging cell was manufactured for estimating variation of paper insulation during 500 hours at $140^{\circ}C$ temperature. To derive the results, it was performed analysis such as tensile strength(TS), depolymerization(DP), dielectric strength(DS), relative permittivity, water content(WC) and furan compound(FC) for aged paper. Also for analyzing correlation between insulating degradation characteristics, we used linear regression method. As as results of linear regression analysis, there was a close correlation between TS and DP. WC, FC. But dielectric strength was a weak correlation with aging time.

• Bulletin of the Korean Chemical Society
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• v.35 no.7
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• pp.2097-2108
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• 2014

Chemical feature based quantitative pharmacophore models were generated using the HypoGen module implemented in DS2.5. The best hypothesis, Hypo1, which was characterized by the highest correlation coefficient (0.96), the highest cost difference (61.60) and the lowest RMSD (0.74), consisted of one hydrogen bond acceptor, one hydrogen bond donor, one hydrophobic and one ring aromatic. The reliability of Hypo1 was validated on the basis of cost analysis, test set, Fischer's randomization method and GH test method. The validated Hypo1 was used as a 3D search query to identify novel inhibitors. The screened molecules were further refined by employing ADMET, docking studies and visual inspection. Three compounds with novel scaffolds were selected as the most promising candidates for the designing of Mcl-1 antagonists. Finally, a 10 ns molecular dynamics simulation was carried out on the complex of receptor and the retrieved ligand to demonstrate that the binding mode was stable during the MD simulation.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.152-152
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• 2013

Mechanism of energy conversion from chemical to electrical during exothermic catalytic reactions at the metal surfaces has been a fascinating and crucial subject in heterogeneous catalysis. A metal-semiconductor Schottky nanodiode is novel device for direct detection of chemically induced hot electrons which have sufficient energy to surmount the Schottky barrier. We measured a continuous chemicurrent during the hydrogen oxidation under of 760 Torr of O2 and 6 Torr of H2 by using Pt/Si and Pt/TiO2 nanodiodes at reaction temperatures and compared the chemicurrent with the reaction turnover rate. The thermoelectric current was measured by carrying out an experiment under O2 condition for elimination of the background current. Gas chromatograph and source meter were used for measurement of the chemical turnover rate and the chemicurrent, respectively. The correlation between the chemicurrent and the chemical turnover rate under hydrogen oxidation implies how hot electrons generated on the metal surface affect hydrogen oxidation.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.8
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• pp.807-812
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• 2005

This study is to investigate the correlation of pore structures of Zeolite 5As modified with acid and their adsorption capacity of toluene vapor using the dynamic adsorption method. The experimental results showed that the modification with acid allowed more micropores and enlarged the existing pores. Toluene vapor was mainly adsorbed on the surface of pores over $15\;{\AA}$ in diameter. The equilibrium adsorption capacity of toluene vapor of the modified Zeolite 5As was in the range of $15{\sim}70\;mg/g$ and the equilibrium adsorption capacity was increased to f times than that of the Zeolite 5A. The correlation between the total cumulative surface area and the equilibrium adsorption capacity was hard to say linear. The correlation in diameter between the cumulative surface area in the range of over $15\;{\AA}$ and the equilibrium adsorption capacity gate the highest correlation factor of 0.997.

• Korean journal of food and cookery science
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• v.21 no.1 s.85
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• pp.103-109
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• 2005

In order to investigate the correlation of the physical chemical characteristics of Kimchi with its sourness and overall acceptability, the pH, the reducing sugar content, the total microbial counts and the lactic acid bacterial counts of Kimchi were examined during fermentation at $5^{\circ}C$, $10^{\circ}C$ and $20^{\circ}C$. In regard to pH, the pH of the fermentation at $10^{\circ}C$ and $20^{\circ}C$ was nearly in inverse proportion to the sourness, whereas the pH at $5^{\circ}C$ fermentation was in less than inverse proportion to the sourness. For the correlation of the reducing sugar and the sourness, sourness and the reducing sugar showed an inverse proportion until the acidity reached $0.8\%\~1.0\%$. The reducing sugar content at $10^{\circ}C$ and $20^{\circ}C$ was nearly similar for the highest overall acceptability, whereas the reducing sugar content at $5^{\circ}C$ was higher than the reducing sugar content at $10^{\circ}C$ and $20^{\circ}C$. In the case of the total microbial count, the total microbial count and the sourness of Kimchi fermented at $5^{\circ}C$did not show the highest values at the same point, but the highest values of the total microbial count and the sourness of Kimchi fermented at $10^{\circ}C$ and $20^{\circ}C$ were the same at a point. Also, at a point for the best overall acceptability, the total microbial count at $10^{\circ}C$ fermentation was the highest, whereas those at $5^{\circ}C$ and $20^{\circ}C$ fermentation were similar. In case of the lactic acid bacterial count, the lactic acid bacterial count and the sourness at $5^{\circ}C$ fermentation did not show the highest value at the same point, but that at $10^{\circ}C$ and $20^{\circ}C$ fermentation did. For the correlation of the physical chemical characteristics with sourness, the sourness of Kimchi fermented at $5^{\circ}C$ showed a very significant correlation with acidity and it also showed a positive correlation with pH and the total microbial count, but these were not significant differences($\alpha$=$0.5\%$). At $10^{\circ}C$ and $20^{\circ}C$ fermentation, the sourness showed very significant correlation with all the physical chemical characteristics.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.2107-2109
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• 2010

• Bulletin of the Korean Chemical Society
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• v.35 no.5
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• pp.1413-1416
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• 2014

A novel topological index (TG Index) has been introduced. The graphical matrix representation of the TG index includes the use of directed subgraphs for the first time in graph theory literature. The application of the TG index on certain properties of polyenes yielded very well correlation data.

• Bulletin of the Korean Chemical Society
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• v.29 no.8
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• pp.1624-1626
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• 2008

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.12 no.6
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• pp.323-328
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• 2002

The model of the shortest chemical bonds is applied for the classification of acentric simple and binary Mo(VI) and W(VI) oxides. It is shown that on the plane of the shortest chemical bonds the compounds are located into the rosette of three intersected ellipses. The correlation between the optical nonlinearity and combination of the bond lengths is discussed.

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2233-2236
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• 2011

We evaluate quantum-mechanical velocity autocorrelation functions from classical molecular dynamics simulations using quantum correction approaches. We apply recently developed approaches to supercritical argon and liquid neon. The results show that the methods provide a solution more efficient than previous methods to investigate quantum-mechanical dynamic behavior in condensed phases. Our numerical results are found to be in excellent agreement with the previous quantum-mechanical results.