• Korean Journal of Soil Science and Fertilizer
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• v.26 no.3
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• pp.151-154
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• 1993

The magnitute of CEC of the reaction product which was produced by the treatment of the natural zeolite power(CEC : 67me/100g) with 3N-NaOH at $80^{\circ}C$ for 30 hours was determined to be about 260me/100g, which was the highest value in all reaction products. By the NaOH-treatment the contents of major clay minerals in natural zeolite was shown to be decreased and it is apparent that new phillipsite was synthesized. Furthermore it is interesting that the phillipsite contents was increased with longer reaction time and higher temperature. After 30 hours treatment the dorminant clay mineral in the reaction product was found to be phillipsite.

• Journal of the Korean Chemical Society
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• v.24 no.4
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• pp.322-328
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• 1980

1,3,5,7-Tetranitro-1,3,5,7-tetraazacyclooctane (homocyclonite) is prepared simultaneously with 1,3,5-trinitro-1,3,5-triazacyclohexane (cyclonite) by nitrolysis of hexamethylenetetramine. The purpose of our study was to detect the existence of intermediate, 1,5-endomethylene-3,7-dinitro-1,3,5,7-tetraazacyclooctane (DPT), by liquid chromatography based on the reaction mechanism, to derive the theoretical equation which is determinated by the ratio of total methylene group vs. amino N, for the proper quantity of paraformaldehyde added in the reaction and to obtain the optimum condition for maximum yield and purity by comparing the experimental results with the theoretical equation.

• Journal of the Korean Chemical Society
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• v.29 no.4
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• pp.441-447
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• 1985

Several benzanilides were prepared by acylation of anilines with substituted benzoyl chlorides. While 2-chlorobenzanilides were photocyclized, 2-methylbenzanilide and 2'-methylbenzanilide were cleaved to give photo-Fries type products. 2-Nitrobenzanilide and 2'-nitrobenzanilide were inert in the above conditions due to lowering energy of the excited state by the nitro group. N, N-dibenzoylaniline and N, N-di-(2-chlorobenzoyl) aniline gave photo-Fries type reaction products effectively. In the benzanilide photo-Fries type reaction the excited singlet state was believed to be involved, since no oxygen effect was observed on the reaction rate. Quantum yield for 2-methylbenzanilide is higher in nonpolar and less viscous solvents than in polar and viscous solvents. The solvent cage radical pair is suggested in the photo-Fries type reaction of benzanilides.

• Journal of Life Science
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• v.22 no.11
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• pp.1451-1455
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• 2012

The study was conducted to investigate the effect of Maillard reaction products (MRPs) on enzymatic browning of crown daisy (Chrysanthmum coronarium var. spatiosum). The MRPs prepared by heating various amino acid and sugar at $90^{\circ}C$ caused a strong inhibitory effect on crown daisy polyphenol oxidase (PPO, ${\sigma}$-diphenol oxygen oxidoreductase, EC 1.10.3.1). As the reaction time of the solution containing glycine and glucose increased at $90^{\circ}C$, the production of MRPs was increased, whereas the amounts of glycine and glucose were decreased. Accordingly, the inhibitory effect of crown daisy PPO activity by MRPs was increased as the amounts of synthesized MRPs were increased. The MRPs synthesized from the various amino acids and sugars significantly reduced the PPO activity, particularly MRPs prepared by glutamine and xylose. The Michealis-Menten constant value ($K_m$) of crown daisy PPO with catechol as a substrate was 22.0 mM, and MRPs were a noncompetitive inhibitor against crown daisy PPO.

• Korean Chemical Engineering Research
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• v.54 no.5
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• pp.698-705
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• 2016

Butyl acetate is produced from acetic acid and butanol via an esterification reaction in reactive distillation (RD). The product, butyl acetate, has been used as an internal entrainer until now. In this case, butyl acetate and water are removed at the top of column and separated into two different phases (organic and aqueous phases) after condensation, and butyl acetate rich organic phase is refluxed into the RD. This method makes butyl acetate remain high at the reactive zone, leading to lower equilibrium conversion and product yield. We introduced an extraneous entrainer to solve the problem. The extraneous entrainer forms a new azeotrope with water. The proposed process provides lower concentration of butyl acetate in the reactive zone than conventional RD processes using an internal entrainer. We compared the yield and production rate of butyl acetate between the proposed and conventional processes through pilot-scale experiments. Experimental and simulation results showed that the proposed process was more efficient than conventional process using internal entrainer.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.139-140
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• 2003

광화학 스모그를 야기하는 오존은 질소산화물과 VOC에 의한 다단계 광화학반응에 의하여 생성된다. 1990년대 초부터 자동차 보급률이 높아지면서, 수도권 지역을 중심으로 고농도 오존 현상이 관찰되었으며 최근에는 지방 주요 도시로 확산되고 있다. 오존은 광화학반응에 의해서 생성되는 제2차 대기오염물질이면서도 반응성이 높아서 다른 화학종의 산화에 지대한 영향을 미치며 일단 생성된 후에도 쉽게 파괴될 수 있다는 점에서 황산화물과 질소산화물과 같은 제2차 대기오염물질과 구별된다. (중략)

• Bulletin of Food Technology
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• v.7 no.3
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• pp.99-104
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• 1994

• Journal of the Korean GEO-environmental Society
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• v.13 no.2
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• pp.75-81
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• 2012

Because N-Nitrosodimethylamine(NDMA) is well-known as a potential carcinogen, extensive research has addressed its treatment by ultraviolet(UV) and its degradation pathway. However, the detailed mechanism by which NDMA is photolyzed to form oxidized products, i.e., ${NO_2}^-$ and ${NO_3}^-$, is still not understood. This study reveals a key reactive species during the photolysis of NDMA. The study on a key reactive species was indirectly performed with the formation of nitrogen oxidized products and reactions between methanol and an unknown reactive species formed during the photolysis of NDMA. The peroxynitrite($ONOO^-$) generated by the direct UV photolysis of NDMA would be identified as a key reactive species in oxidizing nitrogen intermediates to ${NO_2}^-$and ${NO_3}^-$.

• Journal of the Korean Applied Science and Technology
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• v.29 no.3
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• pp.429-434
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• 2012

A kind of Antihistamines, Azelastine HCl which known as modern H1-blockers, was synthesized by four step process using phthalic anhydride, 4-chlorophenylacetic acid, hydrazine 2HCl. The first step was the reaction of removing carboxyl group and hydroxyl group and the second step was saponification of 3-(4-chlorobenzylidene)phthalide. The third step was the nucleophilic addition reactions of primary amines and the fourth step was addition reaction of N-methyl-1-aza-bicyclo[3,2,0]heptane to 4-(4-chlorobenzyl)-1-(2H)phthalazinone. As a result, product was analyzed by FT-IR and $^1H$-NMR and could be obtained with a yield of 80%.

• Journal of the Korean Chemical Society
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• v.27 no.2
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• pp.142-149
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• 1983

Reaction of thianthrene cation radical perchlorate (1) with cumene (4), p-chlorocumene (2), and p-nitrocumene (3) hydroperoxides in acetonitrile at room temperature afforded, inter alia, thianthrene as a common product and 5-(4'-hydroxyphenyl) thianthrenium perchlorate (5) for 4, 5-(5'-chloro-2'-hydroxyphenyl) thianthrenium perchlorate (7) and 5-acetonylthianthrenium perchlorate (6) for 2 and 6 for 3, respectively. Stoichiometry of these reactions showed that 2 moles of 1 gave rise to 1mole of thianthrene and 1 mole of thianthrenium salt (or salts). Nucleophilic reactivity to 1 was found to be in the order of phenol > > p-chlorophenol ${\sim}$ acetone > > p-nitrophenol. Apart from acid-catalyzed heterolytic decomposition of hydroperoxides, small amount of homolytic decomposition products were found from 3 and 4.