• Bulletin of the Korean Chemical Society
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• v.28 no.10
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• pp.1787-1791
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• 2007

Several hydroxylated cinnamic acid derivatives were prepared from the corresponding acids and amino acid residues, and their hypocholesterolemic activities were evaluated in high cholesterol-fed mice. The presence of the double bond in hydroxylated cinnamide derivatives decreases cholesterol-lowering activities and the number of free phenolic hydroxy groups affect greatly the activities. 3,4-Dihydroxy hydrocinnamides obtained from amino acid derivatives containing a hydrophobic side chain such as alanine, valine, phenylalanine, and isoleucine exhibited potent cholesterol-lowering activities.

• YAKHAK HOEJI
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• v.42 no.3
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• pp.257-264
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• 1998

5-Methylthebaine was obtained by treating thebaine with n-butyllithium and methylfluorosulfonate. Hetero Diels-Alder reaction of thebaine and 5-methylthebaine with trifluoroacet aldehyde afforded 14-${\beta}$-(triflu-oro-2-hydroxyethyl)codeine (2) and 14-${\beta}$-(trifluoro-2-hydroxyethyl)-5-methylcodeinone (9). 6-${\alpha}$-OH compound (4) was obtained by employing $CeCl_2$ and $NaBH_4$. After synthesized a derivative substituted for 3-OH (5), using boron tribromied, We synthesized a new derivative that make double bond in C-7, C-8 into epoxode (6), (10). Through inspecting an influence on structure-activity and analgetic action, we are going to examine which opiold acceptor has a selectivity.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.55-60
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• 2001

Influencing factors on flexural toughness of ring-type fiber reinforced concrete(RSFRC) are investigated. An experiment proceeding ASTM C 78 is peformed to make a comparison between ring-type fibers and double-hook type fibers. Most specimen with ring type fibers have failed by the cone type failure, while discrete hook type fibers have failed by fiber pullout. For the hook-type fiber reinforced concrete(SFRC), the first crack load increases, as the fiber mixing volume increases. Aspect ratio(fiber length/fiber diameter) is critical for hook type fibers, so the flexural toughness increases significantly, as the length of fiber increases. However, for the ring type, the toughness indices Increase as the number of fibers in the specimen increases. Since there is no bond problem between the ring fiber and the concrete matrix, the aspect ratio does not affect the performance of the composite material with the newly developed steel fibers. Influencing factors with respect to flexural toughness RSFRC were observed to be ring diameter, diameter of steel fiber and fiber content.

• Journal of Photoscience
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• v.10 no.2
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• pp.181-184
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• 2003

Photochemical reactions of some organic molecules on titanium dioxide were investigated in methanol. A methanolic solution of trans-cinnamic acid and titanium dioxide was irradiated with 300 nm UV lamps for 24 h to afford methyl cinnamate. In the case of trans-cinnamamide, the major product was found to be 3-phenylpropionamide, i.e., a saturation product of ethylenic double bond. However, irradiation of urocanic acid, caffeic acid, ethyl cinnamate, trans-chalcone, trans-cinnamonitrile, trans-stilbene or trans, trans-1,4-diphenyl-1,3-butadiene on titanium dioxide under the same conditions did not give any noticeable products. Meanwhile, when irradiated some aromatic aldehydes, such as trans-cinnamaldehyde, l-naphthaldehyde, and 2-naphthaldehyde in methanol, vicinal diols and alcohols derived from the diols were produced. On the other hand, irradiation of 9-anthraldehyde and titanium dioxide in methanol afforded only alcohols, in which diol was not observed.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.3
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• pp.83-90
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• 2004

Plasma/catalyst combined reactor was designed to overcome the limits of plasma and catalyst technologies. Optimum reductant and catalyst was selected from screening test. Experiments about the concentrations of reactant and $H_2O$ and the effect of temperature were carried out. Hydrocarbons with double bond such as propylene and so on were more reactive than any other reductants in plasma/catalyst condition. Photocatalyst, especially hombikat >$TiO_2$ with the largest surface area among the catalysts tested, showed the highest DeNOx efficiency in plasma/catalyst reaction. As the concentration of $H_2O$ increased, the removal of NO was enhanced. The increased concentration of >$O_2$ promoted the reaction of NO which was oxidized to$NO_2$.

• Journal of the Korean Graphic Arts Communication Society
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• v.16 no.3
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• pp.61-80
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• 1998

To investigate in influence of photosensitizer used with benzophenone(BP) in the curing rate and physical properties of UV curable hard coating on plastic, we prepared UV curable clear and pigmented coatings with DEA, DMA, NPM and TEA as photosensitizer, respectively. The curing rate calculated from the decrease of the absorbance of acrylic double bond measured by FT-IR spectroscopy increased s follows; DEA>DMA>NPM>TEA. this order could be explained by the reactivity of diethylamino group of DEA and the ease of formation of activated complex between BP and photosensitizer during the curing process. In UV curable pigmented coatings, the order of curing rate increased as follows; DEA>DMA>TEA>NPM. It was found that the curing rate of the pigmented coating can be increased by light scattering of TiO$_2$. The hardness of coating film cured by photosensitization of DEA and DMA is higher than other photosensitizers due to the crosslinking reaction of DEA and DMA radical bound to polymer backbone.

• Journal of the Korean Applied Science and Technology
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• v.9 no.2
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• pp.119-126
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• 1992

The kinetics of the hydrolysis of indolylacrylophenone derivatives(IA) was investigated by ultraviolet spectrophotometry in 30% dioxane-$H_2O$ at 25$^{\circ}C$ Rate equations were obtained over a wide pH range. On the basis of rate equation, general base catalysis and Hammett's plot, the mechanism of hydrolysis to the (IA) were proposed: Below pH 3.0, the hydrolysis of (IA) was proportional to hydronium ion concentration, between pH 4.0${\sim}$9.0 neutral water molecule and hydroxide ion were added to carbon-carbon double bond and over pH 10.0 hydrolysis of (IA) was proportional to hydroxide ion concentration.

• Archives of Pharmacal Research
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• v.26 no.3
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• pp.207-209
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• 2003

A new unsaturated hydroxy acid was isolated from the stem bark extract of Albizzia julibrissin through repeated silica gel and Sephadex LH-20 column chromatography. The chemical structure of the new acid was determined as (E)-4-hydroxy-dodec-2-enedioic acid on the basis of several spectral data including 2D-NMR. The stereochemical feature of the double bond was determined to be E on the basis of the coupling pattern of related proton signals in the $^1H-NMR$ and COSY experiments.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.772-775
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• 2006

Cinnamate polymers are well known photoreactive polymers due to [2+2] cycloaddition reaction of cinnamate side group. In this work, we have found that the cinnamate side groups could be also reacted by thermal energy, and this reaction is presumed to attribute to the radical reaction of carbon double bond in the cinnamate groups. Contrary to the photocycloaddition reaction of the cinnamate side groups, the thermal reaction of cinnamate side group was closely related to the flexibility of polymer backbone. The difference of the mechanism between the photocycloaddition reaction and thermal crosslinking reaction was confirmed by $^1H-NMR$$ and $^{13}C-NMR$ analysis of the model compound.

• Archives of Pharmacal Research
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• v.21 no.3
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• pp.338-343
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• 1998

$2^1$-Fluorohexopyranosyl nucleosides 1a and 1b which contained a bioisosteric double bond and a fluorine were synthesized in 12 steps, starting from D-galactose. During diethylaminosulfur trifluoride (DAST) fluorination, retention of stereochemistry was observed through the participation of methoxy or chloro group at the 6-posiition of the purine base. The final nucleosides 1a and 1b were found to be inactive against HIV-1 and HSV-1,2.