• Journal of the Korean Applied Science and Technology
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• v.4 no.1
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• pp.67-71
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• 1987

The transesterification reaction between diethanolamine and methyl methacrylate was kinetically investigated in the presence of various metal acetate catalysts at $120^{\circ}C$. The amount of reacted methyl methacrylate was measured by gas chromatography and liquid chromatography, and the reaction rate also measured from the amount of reaction products and reactants under each catalyst. The transesterification reaction was carried out in the first order with respect to the concentration of diethanolamine and methyl methacrylate, respectively. The over-all order is 2nd. The apparent rate constant was found to obey first-order kinetics with respect to the concentration of catalyst. The maximum reaction rate was appeared at the range of 1.4 to 1.6 of electronegativity of metal ions and instability constant of metal acetates.

• Korean Journal of Food Science and Technology
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• v.15 no.2
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• pp.195-201
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• 1983

Lipids isolated from three barley samples were identified and quantitated by column, thin layer and gas liquid chromatographic techniques. These lipids were shown to consist of 69.3-73.1% neutral lipids, 9.6-16.5% glycolipids, and 14.2-17.9% phospholipids. Among the neutral lipids, triglycerides were predominant (54.2 to 55.7%) with smaller amounts of 1,2-diglycerides, 1,3-diglycerides, free sterols, free fatty acids, steryl esters, and three unknown being present. Among the glycolipids, digalactosyl diglycerides (31.3 to 33.2%) and monogalactosyl diglycerides (26.2 to 29.6%) were the most abundant. Esterified steryl glycosides, steryl glycosides, cerebrosides, sulfolipids, and an unknown component were present as minor components. Of the phosopholipids, phosphatidyl cholines and serines, lysophosphatidyl cholines, and phosphatidyl ethanolamines were the major components, comprising over 80% of this class. The major fatty acids in the total and the three lipid classes were palmitic, oleic, linoleic and linolenic acids. However, the neutral lipids fraction contained more oleic acid than other lipid fractions, and the phospholipids fraction contained more palmitic acid than the other lipid fractions.

• Korean Journal of Food Science and Technology
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• v.18 no.2
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• pp.153-157
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• 1986

Changes in lipid components of Gae-bul, Urechis unicinctus, during hot-air drying ($40^{\circ}C$, 7 hrs) were studied. Raw sample contained 1.3% total lipid (TL) which consisted of 35.1% neutral lipid (NL), 18.0% glycolipid (GL) and 46.9% phospholipid (PL), and dried sample contained 5.3% TL which consisted of 51.8% NL, 20.5%GL and 27.7% PL. There were about 40% decrease in PL content and a slight increase in NL content during drying. The NL of raw sample mainly consists of triglyceride (TG, 39.8%), free sterol (FS, 39.6%), free fatty acid (FFA, 12.2%). and also identified diglyceride (DG), monoglyceride and esterified sterol and hydrocarbon in less quantify. The percent of TG and FS decreased, while that of FFA and DG increased during drying. And main components in the PL were phosphatidyl choline (PC,45.6%), phosphatidyl ethanolamine (PE,34.8%), and followed by phosphatidyl serine (PS) and an unknown substance. In the components of PL, PE, PS and PC decreased slightly in order during drying. And major fatty acids of raw and dried samples were generally 16:0, 18: 1, 18:3, and 20:5. The content of the polyenoic acid such as 20:5 decreased. while the saturated acid increased slightly during drying.

• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.582-587
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• 2022

Biphasic solvents are attracting attention as energy-reducing solvents for capturing CO₂ from flue gas in combustion process. In this study, considering diethylenetriamine (DETA) and diethylethanolamine (DEEA) mixed solvents, one of the biphasic solvents by blending of two types of amines, the CO₂ absorption rates of DETA and DEEA was measured by wetted wall column. The effects of DETA and DEEA concentrations and operating temperature on the overall mass transfer coefficient were investigated. As a result, the overall mass transfer coefficient was proportional to the DETA concentration. However, in the case of the DEEA concentration, the effect was small and when the concentration was exceeded, the overall mass transfer coefficient decreased. The DETA aqueous solution showed little change in the overall mass transfer coefficient with the operating temperature, whereas the DEEA aqueous solution increased the overall mass transfer coefficient with the operating temperature. As a result of obtaining the observed reaction rate constant under the pseudo-first-order reaction assumption, it was found that the observed reaction rate constant in DETA aqueous solution was proportional to the DETA concentration, but DEEA did not fit the pseudo-first-order reaction assumption.

• Journal of the Korean Applied Science and Technology
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• v.3 no.2
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• pp.41-47
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• 1986

The transesterification reaction between diethanolamine and methyl-methacrylate was kinetically investigated in the presence of various metal acetate catalysts at $120^{\circ}C$. The quantity of methylmethacrylate reacted in the reaction flask was measured by gas chromatography and liquid chromatography, and the reaction rate was investigated by measuring of the quantity of products and reactnts under various catalysts. The transesterification reaction was carried out in the first order reaction kinetics with respect to the concentration of diethanolamine and methylmethacrylate, respectively. The apparent rate constant was found to obey first-order kinetics with respect to the concentration of catalyst. The linear relationship was shown between apparent rate constant and reciprocal absolute temperature, and by the Arrhenius plot, the activation energy has been calculated as 11.08 Kcal with zinc acetate catalyst, 17.99 Kcal without catalyst. The maximum reaction rate was appeared at the range of 1.4 to 1.6 of electronegativity of metal ions and instability constant of metal acetates.

• Korean Journal of Food Science and Technology
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• v.13 no.2
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• pp.142-145
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• 1981

A modified hydroxamate method was developed for determination of fat content in milk. Fat globules in milk were destroyed by adding ethanol and diethyl ether, and a homogeneous reaction system was obtained. The homogenate was reacted with hydroxylamine, milk fat formed ferric hydroxamate chelates which had red-purple color, and the ferric hydroxamate chelates was analyzed colorimetrically. This method was simpler than original hydroxamate method and comparable with the Babcock method in accuracy.

• Polymer(Korea)
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• v.28 no.6
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• pp.502-508
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• 2004

Cationic liposomes for cancer treatment have been developed in the field of chemotharpy. It was well combined on the surface of anionic tumor cell membrane by electrostatic interaction. Thus, the object of this study was to prepare the cationic liposomes capable of forming an ionic complex with the anionic cell membrane. To prepare the cationic liposomes, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE) as a cationic lipid material and polyethylenimine (PEI) as a cationic polymer were synthesized. Ionic property on the surface of liposomes was determined by the zeta potential. The adsorption characteristics of plasma protein for liposome in bovine serum were determined by the particle size and turbidity change. To estimate the stability of liposome in buffered solution, the change of particle size was measured at room temperature for seven days. The cationic liposomes were absorbed a large amount of plasma protein in bovine serum because plasma protein having anionic charge was fixed on the surface of cationic liposomes. This result indicate that the modification on the surface of liposomes using cationic polyethylenimine enhances the protein adsorption in bovine serum. Additionaly, cationic liposomes showed good stability in buffered solution for seven days.

• Journal of the Korean Chemical Society
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• v.44 no.6
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• pp.507-512
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• 2000

A new copper(II) complex, Cu(dpb)(NO$_3$)$_2$(H$_2$O) (dpb=2,2'-dipyridylbenzylamine) (1) was synthesized from the reaction of Cu(NO$_3$)$_2$·3H$_2$O and dpb in ethanol solution followed by recrystallization in acetonitrile. The structure of 1 was determined by X-ray diffraction methods. The single crystal structure was characterized as follows: space group P2$_1$/c, Z=4, a=12.501(9)$\AA$, b=9.231(10)$\AA$, c=17.119(6)$\AA$, $\alpha$=90$^{\circ}$, $\beta$=107.33(4)$^{\circ}$, $\gamma$=90$^{\circ}$, V=1885.8(2)$\AA^3$, R$_1$=0.0647, $_{w}R$_2$$=0.1866 for 3258 reflections. Compound was a typical paramagnetic copper(II) complex coordinated by 2,2'-dipyridylamine derivative ligand, which was confirmed by EPR, NMR, UV/VIS, and IR spectroscopy.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.1
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• pp.72-81
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• 2024

In this study, DEIPA was used for enhancing cementitious performance of bottom ash replaced cement. By applying the partial or no-known crystal structure method to X-ray diffraction data, the amounts of amorphous bottom ash and calcium silicate hydrate(C-S-H) could be separated and quantified. In the sample without DEIPA, the bottom ash hardly reacted, resulting in low compressive strength. However, the addition of DEIPA not only altered the hydration behavior of the cement but also enhanced the pozzolanic reaction between bottom ash and calcium hydroxide, leading to the generation of additional C-S-H. This resulted in high compressive strength not only in the early stages but also in the later stages. Therefore, with the addition of DEIPA during the pulverization of the bottom ash, the reactivity of the bottom ash was significantly improved. Hence, there is potential in the development of bottom ash replacement cement.

• Applied Biological Chemistry
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• v.35 no.3
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• pp.146-151
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• 1992

To investigate changes in fatty acid and lipid composition of maturing perilla (Perilla frutescens var. japonica Hara) seeds, Suweon 10 and Jeju varieties were subjected to lipid analysis. The results were summarized as follows; As perilla seeds matured, content of glycolipid and phospholipid decreased. Glycolipid and phospholipid of mature seed were 25.4% and 4.5% of total lipids in Suweon 10 and those from Jeju were 44.5%, 4.0%, respectively. Cerebroside, galatosyl diglyceride and monogalatosyl diglyceride were major constitutents of ether-extractable glycolipids in developing perilla seeds. Monogalatosyl diglyceride, the richest constitutent in the early stage of seed development, decreased rapidly as seeds matured. In ether-extractable glycolipid of mature Suweon 10 seeds, content of linolenic acid was 51.1% which was higher than 19.4% of oleic acid of total acids. However, in Jeju variety, content of oleic acid was 31% which was higher than 18.6% of linolenic acid. Phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl glycerol and lysophosphatidyl inositol were major constituents of phospholipids. Content of phosphatidyl glycerol in developing seeds showed irregular changes in Jeju but in Suweon 10, it decreased after rapid increase in the early stage of seed development. Olieic acid ranges $28.7{\sim}35.2%$, linolenic acid $8.2{\sim}11.2%$, linoleic acid $16.4{\sim}32.5%$ and Palmitic acid $22.7{\sim}29.9%$ of total fatty acids in methanol-ertractible phospholipid of mature perilla seeds.