• 한국응용과학기술학회지
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• 제8권1호
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• pp.45-49
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• 1991

The synthesis of urocanic acid which was started D-fructose, and its alkyl esters, urocanic ethyl ester and urocanic isobutyl ester, were prepared by esterificated. Urocanic ethyl ester and urocanic isobutyl ester were insoluble in water and soluble most organic solvents (ethanol, benzene, toluene, pyridine, THF, DMF) which adds to their practical applicability, and absorb ultraviolet light of greater wavelength than the free acid and there by are more effective for shielding sensitive materials, including the humanbody, from the chemically most effective portion of the solar ultraviolet spectrum.

• 한국염색가공학회지
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• 제15권4호
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• pp.17-23
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• 2003

Fourier transform infrared spectroscopy(FT-IR) was used to characterize the intermolecular ester crosslinkages in cotton cellulose. The FT-IR data show that the band of the ester carbonyl group can be separated from overlapping carboxyl/carbonyl band by converting carboxyl group to carboxylate. When esterification occurs between a polycarboxylic acid and cotton cellulose, the carbonyl groups retained in the cotton exist in three forms; ester, carboxyl, and carboxylate anion. The FT-IR data were also correlated to the durable press rating result obtained. The appearance of BTCA-finished durable press silk/cotton fabrics were improved.

• Fibers and Polymers
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• 제2권2호
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• pp.81-85
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• 2001

The effects of rate of phase separation to ester interchange reactions and the repulsive pair interaction energy on the phase behavior in a phase-separated immiscible polyester blend are investigated using a Monte Carlo simulation method. The time evolution of structure factor and the degree of randomness are monitored as a function of homogenization time. When the phase separation is dominant over ester interchange reactions, the domain size slowly increases with homogenization time. However, when the pair interaction becomes less repulsive, the domain size does not significantly change with homogenization time. On the other hand, when ester interchange reactions are dominant over the phase separation, the homogenization proceeds without a change in the domain size. The higher the extent of phase separation, the lower the increasing rate of the DR. However, when the phase separation is sufficiently dominant, the effect of the extent of phase separation on the increasing rate of the degree of randomness become less significant.

• 대한화학회지
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• 제35권6호
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• pp.725-729
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• 1991

한국 서해 상낙월도에서 채집한 연체 동물인 Bullacta exarata로부터 통상적인 9-hexadecenoic acid ethyl ester 이외에 불포화된 all-cis-5,8,11,14-eicosatetraenoic(arachidonic), 7,10,13-hexadecatrienoic, 10,13-octadecadienoic acid ethyl ester 및 상당량의 glyceryl ether인 chimyl alcohol이 검출되었다.

• 동아시아식생활학회지
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• 제3권1호
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• pp.67-71
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• 1993

This study ws prepared to evaluate sensory characteristics about appearance, color, texture and overall acceptability of rice extrudate with added glycerin fatty acid ester by balance incomplete block design. According to evaluated mean of adjusted treatments, appearance and color were represented maximum value in rice extrudate with added 3.0% and 1.0% glycerin fatty acid ester respectively. Extrudate with added 1.5% emulsifier revealed best texture and overall acceptability among whole treatments. On the results of this research about sensory characteristics, extrudate with added 1.5% glycerin fatty acid ester was considered excellent because of highest score of texture and overall acceptability, and predominent score of appearance and color.

• Archives of Pharmacal Research
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• 제13권3호
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• pp.240-245
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• 1990

Asymmetric 2, 6-dimethyl-4-aryl-1, 4-dihydropyridine-3, 5-dicarboxylate with [N-(3, 4-methylenedioxybenzyl)-N-methyl] aminoethyl group as the ester moiety and related 1, 4-dihydropyridine derivatives were prepared and tested for the effects on vascular smooth muscles. 2-6-dimethyl-4-(3'-nitrophenyl)1-4-dihydropyridine-3, 5-dicarboxylic acid 3-[N-(3', 4-methylenedioxybenzyl-N-methyl] aminoethyl ester 5-methyl ester (11) and 2, 6-dimethyl-4-(3'-nitrophenyl)-1, 4-dihydropyridine-3, 5-icarboxylic acid 3-[N-2', 3'-methylenedioxybenzyl)-N-methyl] aminoethyl ester 5-ethyl ester (150 showed potent vasodilating activities $IC_{50}$($10_{-8}M$) was 2, 6 and 2.7 for 11 and 15, compared with 3.5 for nicardipine.

• 설비공학논문집
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• 제14권4호
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• pp.285-292
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• 2002

The vapor pressure and miscibility measurement apparatus was developed and used to obtain data for refrigerant/oil mixture. The vapor pressure and miscibility data for R-404A/32 ISO VG polyol ester (POE) oil mixture and R-404A/46 ISO VG polyol ester oil mixture are obtained over the temperature range from -20 to $60^{\circ}$ with at $10^{\circ}$ intervals and the oil concentration range from 0 to 70 wt%. Using the experimental data, an empirical model was developed to predict the temperature vapor pressure-concentration relations for R-404A/46 ISO VG polyol ester oil mixtures at equilibrium. In the R-404A/32 ISO VG polyol ester oil mixture, the average root-mean-square deviation between measured data and calculated results from the empirical model is 1.24% and in the R-404A/46 ISO VG polyol ester oil mixture, that is 1.37%. Miscibility for R-404A/32 ISO VG polyol ester oil mixture was observed all over the experimental conditions. Immiscibility for R-404A/So1est 46 oil mixture was observed at the low oil concentrations (20~30 wt%) over the high experimental temperature range (50~$60^{\circ}$).

• Composites Research
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• 제27권1호
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• pp.19-24
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• 2014

본 연구에서 아마/비닐에스테르(Flax/vinyl ester)를 적용한 친환경 구조물 설계를 위한 선행 연구로서 아마/비닐 에스테르 자연 섬유 복합재료의 기계적 물성치를 분석하였다. 시편 제작을 위해 VARTM 제작 공법이 적용되었다. 참고문헌에서 제시한 자연 섬유 복합재료의 물성치와 본 연구에서 제작된 시편의 물성치를 비교하였다. 이 결과를 바탕으로 아마/비닐 에스테르 복합재료가 친환경 구조물에 적용하는 것이 유리함을 확인하였다.

• Archives of Pharmacal Research
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• 제27권3호
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• pp.300-304
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• 2004

Five caffeic acid derivatives; methyl ester of caffeoylglycolic acid (1), dimethyl ester of caffeoyltartaric acid (2), dimethyl ester of caffeoyltartronic acid (3), monomethyl ester of caffeoyltartronic acid (4), methyl ester of caffeic acid (5), and some other secondary metabolites including; quercetin, quercetin 3-O-$\beta$-D-glucuronide methyl ester, kaempferol, 3,5,7,4'-O-tetramethylkaempferol, $\beta$-sitosterol glucoside, 2$\alpha$-hydroxyursolic acid and 2,24-dihydroxyursolic acid, have been isolated and characterized. All the isolated compounds were characterized with the help of NMR spectroscopy and mass spectrometry. Structure of compound 3 was also confirmed by a single X-ray crystallographic technique. Isolates were evaluated for anti-oxidant activities and most of the tested compounds were found to be potent in DPPH free radical scavenging ($IC_{50}{\;}={\;}4.56-14.17{\;}{\mu\textrm{g}}/mL$) and superoxide anion scavenging ($IC_{50}{\;}={\;}0.58-7.39{\;}{\mu\textrm{g}}/mL$) assays.

• Tribology and Lubricants
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• 제15권1호
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• pp.8-16
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• 1999

The electrorheological (ER) behavior of suspensions in silicone oil of phosphoric ester cellulose powder (average particle size : 18$\pm$1 ${\mu}{\textrm}{m}$) was investigated on the elevated temperature up to 10$0^{\circ}C$. For development of anhydrous ER fluids using at wide temperature range, it should be researched to how the effect of temperature on the ER activities. As a first step, the anhydrous ER suspensions mixing with the phosphoric ester cellulose particles which were made from the phosphoric ester reaction of cellulose were measured. As increasing the temperature, not only the analysis of electrical properties such as dielectric constant current density and electrical conductivity but also the rheological properties of ER fluids were studied. From the experimental results, the temperature had a large influence to the ER properties of anhydrous ER fluids. The current density, conductivity and elecoorheological effect ($\tau$$_{A}$$\tau$$_{0}$) of phosphoric ester cellulose ER fluids were proportional to the temperature with power law. And the shear stress of them was closely related with the square of dielectric constant mismatch parameter ($\beta$$^2$) under constant shear rate and electric field.d.