• 상하수도학회지
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• 제19권1호
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• pp.98-105
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• 2005

The effects of chlorination on the elimination of three estrogenic chemicals such as $17{\beta}$-estradiol (E2), nonylphenol (NP) and bis-phenol A (BPA) were investigated using yeast two-hybrid assay (YTA), estrogen receptor competition assay (ER-CA), and high-performance liquid chromatography/mass spectrometer (LC/MS). Results of YTA, ECA and the analysis of LC/MS indicated that the estrogenic activity of above mentioned three endocrine disruptors were significantly reduced as the result of chlorination. The decrease in estrogenic activity paralleled with decrease in estrogenic chemicals under the influence of free chlorine. One common characteristic of estrogenic chemicals is the presence of a phenolic ring. Considering that a phenolic ring is likely to undergo some sort of transformation in aqueous chlorination solution, the above mentioned results may be applied to the rest of the other estrogenic chemicals in natural waters.

• 약학회지
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• 제43권6호
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• pp.762-770
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• 1999

A series of vitamin-containing Pt(II) complexes of the type [Pt (FMN) (L)] (FMN=flavin mononucleotide, L=ethylenediamine, 1,3-propanediamine, 1,4-bu-tanediamine) was synthesizd and characterized by IR, electronic absorption, elemental analysis and FAB=Mass. The coordination sites of FMN to Pt(II) ions were determined to be N(5) and O(6) with resultant chelate ring formation. Theses compounds have much better water solubility (30-35 mg/ml) than cisplatin (1 mg/ml). The anticancer activity of this vitamin-containing Pt(II) series was investigated by MTT assay against mouse and human leukemia cell lines in vitro. Among these compounds, FMN (1,4-butanediamine) Pt(II) having seven-membered ring structure as amine ligand showed moderate anticancer activity.

• Bulletin of the Korean Chemical Society
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• 제22권8호
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• pp.842-846
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• 2001

Solvolyses of N-methyl-N-phenylcarbamoyl chlorides in aqueous binary mixtures of acetone, ethanol, methanol and in water, D2O, and 50% D2O-CH3OD are investigated at 25.0 $^{\circ}C.$ The Grunwald-Winstein plots of first-ord er rate constants for N-methyl-N-phenylcarbamoyl chlorides with YCl (based on 2-adamantyl chloride) show a dispersion phenomenon. The ring parameter (I) has been shown to give considerable improvement when it is added as an hI term to the original Grunwald-Winstein and extended Grunwald-Winstein correlations for the solvolyses of N-methyl-N-phenylcarbamoyl chlorides. This study has shown that the magnitude of l, m and h values associated with a change of solvent composition is able to predict the dissociative SN2 transition state. The kinetic solvent isotope effects determined in deuterated water are consistent with the proposed mechanism of the general base catalyzed and/or a dissociative SN2 mechanism channel for N-methyl-N-phenylcarbamoyl chlorides solvolyses.

• Bulletin of the Korean Chemical Society
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• 제24권6호
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• pp.731-732
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• 2003

Mutagen X (MX), 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone is one of the most potent directing acting mutagen ever tested in SAL TA100 assay. Although MX analogues have been synthesized, tested for mutagenicity and modeled by structure-activity relationship (SAR) methods, the mechanism of interaction of these compounds with DNA to produce their remarkable mutagenic potency remains unresolved. MX exists as an equilibrium mixture of both ring and open form in water. This equilibrium is very fast for Ames test. Because the mixture is not separable by experimental methods, it is not clear which one is really responsible for the observed mutagenicity. There have been many debates that which one is really responsible for the observed mutagenicity. We used ab initio methods for the MX analogues. It seems both ring and open form could react with DNA bases as electrophiles. However, every open form has consistently lower LUMO energy than corresponding ring form. It is reasonable to assume that the major reaction will go through via open form for MX analogues. This suggest that the open form is more likely really mutagenic.

• 대한안전경영과학회지
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• 제2권4호
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• pp.197-208
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• 2000

ABS sensor ring has been manufactured by powder metallurgy (P/M) method using 400 series ferrite stainless steel. The results are following. It is supposedly sufficient to use for control computer due to good experimental results of magnetic characteristics. Compared with sensor ring made by iron, 400 series ferrite stainless steel has shown a good corrosion resistance without an addition surface treatment. Thus the decreasing production process has been obtained. As a result mechanical characteristics of hardness and tensile test, 400 series ferrite stainless steel shown a good endurance when it is combined to constant velocity joint(C/V), and has a good hardness properties endurable to sand and pebble impact. The products before sintering are much more corrodible in the condition of spray test of salt water and ammonia than humidity and nitrogen condition.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 춘계학술대회논문집
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• pp.119-124
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• 1999

Quantitative evaluation of the tribological conditions at the tool-workpiece interface in metal forming is usually accomplished by the ring-compressinon. test This paper describes an experimental investigation into shear friction factor under cold and hot forming conditions according to materials and lubricants using the ring compression test. Six different materials and five different lubricants were applied in the experiments. calibration curves with the friction coefficient were obtained using FEM analysis and verified by the verified by the experimental results. The influence of materials and lubricants level on friction are discussed. In the ring compression test the shear friction factor has a different from steels and aluminum water base graphite lubricants on cold working conditions and hot working conditions.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.312-315
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• 2008

The flow structure behind circular and elliptical type rings embedded in a cross-flow was investigated experimentally using two-frame particle image velocimetry (PIV). The experiments were performed in a circulating water channel with a test section of 0.35m height ${\times}$ 0.3m width ${\times}$ 1.1m length. PIV measurements were carried out with varying the Reynolds number in the range of 4.5 ${\times}$ $10^2$ - 4.5 ${\times}$ $10^3$. In the present study, turbulent flow structures in the stream-wise direction and span-wise direction were investigated. The mean velocity field distribution was obtained by statistical-averaging instantaneous velocity fields. The spatial distributions of turbulent statistics such as turbulent intensities and turbulent kinetic energy were also investigated.

• 전기학회논문지
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• 제57권9호
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• pp.1589-1593
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• 2008

The condition of a high voltage motor was monitored with the motor performance monitor (MPM) at the motor control center. The MPM detected defects in the rotor bar and end ring and input power according to motor and load conditions. The assessment of the condition of a coal pulverizer motor indicated it was clearly in good condition in terms of the rotor bars, over voltage, and motor performance. However, the side bands at frequency, 56.48 Hz indicated existence of rotor end-ring fault. The large torque ripple indicated abnormal operating conditions. After visual inspection, it has been observed that an impeller blade of the circulating water pump was broken off causing the irregular torque pattern.

• 대한안전경영과학회지
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• 제5권1호
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• pp.129-141
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• 2003

In this thesis, using the 400 series ferrite stainless steel such as 434LD$_2$ which are furter excellent then the existing ferric products in mechanical characteristics, and experiment has been conducted on corrosion resistance of sensor ring. The results are following. 1. The products before sintering are much more corrodible in the condition of spray test of salt water and ammonia than humidity and nitrogen condition. 2. 434LD$_2$ ferrite stainless steel has shown a good corrosion resistance without an addition surface treatment. thus the decreasing production process has been obtained. 3. As hardness value of $H_{RB}$ 80 and tensile test, 434LD$_2$ ferrite stainless steel with show a good endurance when it is combined to constant velocity joint (c/v joint), and has a good hardness properties endurable to sand and pebble impact.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 추계 학술논문 발표대회
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• pp.124-125
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• 2017

In this study, the spalling properties of Polypropylene reinforced concrete were evaluated by the restrained ring-type test. As a result of the experiment with the fiber mixture ratio set at 0, 0.15 vol.%, The PP fiber reinforced specimen showed lower water vapor pressure as a whole than the Plain specimen, but the restraint stress was measured to be higher. This is thought to be due to the fact that higher thermal stresses were applied in the PP fiber reinforced test specimen.