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Ha, Dong-Myeong;Lee, Sung-Jin
- Journal of the Korean Institute of Gas
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- v.13 no.5
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- pp.20-25
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- 2009
Low explosion limits of flammable liquid mixtures can be calculated with the appropriate use of the fundamental laws of Raoult, Dalton, Le Chatelier and activity coefficient models. In this paper, Raoult's law, van Laar equation and Wilson equation are shown to be applicable for the prediction of the lower explosion limits for ethylacetate+ethanol and ethanol+toluene systems. The calculated values based on Raoult's law were found to be better than those based on van Laar and Wilson equations.
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Zhoh, Choon-Koo;Kim, Kyung-Rae;Kim, Joo-Chan
- Journal of the Society of Cosmetic Scientists of Korea
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- v.33 no.4
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- pp.269-273
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- 2007
We studied anti-microbial and anti-oxidant activities of bio-active components in stem of Juniperus chinensis L. and leaf of Abies koreana Wilson. Those plants of needle leaf tree family were reported to contain anti-cancer compounds. The anti-bacterial activity was tested by Broth dilution method against Escherichia coli and Staphylococcus aureus. As results, Juniperus chinensis L. and Abies koreana Wilson extracts showed 17.0% and 8.5% higher anti-bacterial activity than methyl paraben, respectively. The free radical scavenging activity of Juniperus chinensis L. and Abies koreana Wilson extracts showed 45 % and 44 % at 5,000 ppm. We measured polyphenol (catechin equivalent) and flavonoids quantity. The Juniperus chinensis L. extract contained 312 mg/g of polyphenol and 105 mg/g of flavonoids. The Abies koreana Wilson extract contained 280 mg/g of polyphenol and 103.8 mg/g of flavonoids. The cytotoxicity of extracts was measured by neutral red assay. Extracts did not affect the viability of CCK-986sk cells up to a concentration of 1,250 ppm. In conclusion, these data suggest that extracts of needle leaf trees would be usefull as antiseptic agents and anti-oxidants for cosmetic products.
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Yu, Seong-Jae;Myung, Pyung-Keun;Kwon, Byung-Mok;Sung, Nack-Do
- Applied Biological Chemistry
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- v.43 no.2
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- pp.95-99
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- 2000
A series of hetero ring (X) substitued chalcone derivatives with farnesyl protein transferase (FPTase) inhibition activities $(pI_{50})$ values determined in vitro is analyzed by modified Free-Wilson (F-W) and Hansch method for quantitative structure activity relationship (QSARs). On the basis of F-W analysis on the FPTase inhibitory activity of a training set of the compounds, none of the (X)-substituents were not contribute the activity. But the net charge of ${\alpha}$ carbon atom is contribute the activity than that of ${\beta}$ carbon atom. And the relative orders of the (Y)-substituents on the activity are ortho>meta>para-substituents. According to Hansch approach, the activities would depend largely on the optimal, $(R_{opt.}=-0.35)$ resonance effect with ortho substituted $(I_o>0)$ electron donating group (R<0) and STERIMOL parameter, $B_1$ constant. The inhibition activity between hetro ring substituents have been a proportioned with each others and none substituent(H), 45 showed the highest FPTase inhibition $(pI_{50}=4.30)$ activity.
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Do, Jeong-Yun;Kim, Doo-Kie
- Journal of the Korea institute for structural maintenance and inspection
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- v.19 no.5
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- pp.92-103
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- 2015
Box-Wilson experimental design method, known as central composite design, is the design of any information-gathering exercises where variation is present. This method was devised to gather as much data as possible in spite of the low design cost. This method was employed to model the effect of mixing factors on several performances of 60 MPa high strength self compacting concrete and to numerically calculate the optimal mix proportion. The nonlinear relations between factors and responses of HSSCC were approximated in the form of second order polynomial equation. In order to characterize five performances like compressive strength, passing ability, segregation resistance, manufacturing cost and density depending on five factors like water-binder ratio, cement content, fine aggregate percentage, fly ash content and superplasticizer content, the experiments were made at the total 52 experimental points composed of 32 factorial points, 10 axial points and 10 center points. The study results showed that Box-Wilson experimental design was really effective in designing the experiments and analyzing the relation between factor and response.
https://doi.org/10.11112/jksmi.2015.19.5.092 인용 PDF KSCI