• Polymer(Korea)
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• v.36 no.2
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• pp.177-181
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• 2012

This study presents the preparation of double emulsions in a poly(dimethylsiloxane) (PDMS)-based microfluidic device. To improve the wettability of hydrophilic continuous phase onto a hydrophobic PDMS microchannel, the surface was modified with 3-(trimethoxysilyl) propyl methacrylate (TPM) and then sequentially reacted with acrylic acid monomer solution, which produced selective covalent bonding between acrylic acids and methacrylate groups. For the proof of selective surface modification, tolonium chloride solution was used to identify the modified region and we confirmed that the approach was successfully performed. When water containing 0.5% w/w sodium dodecyl sulfate and 1% w/w Span80 with hexadecane were loaded into the selectively modified microfluidic channels, we can produce stable double emulsion. Based on the spreading coefficients, we predict the morphology of double emulsions. Our proposed method efficiently produces monodisperse double emulsions having 48.5 ${\mu}m$(CV:1.6%) core and 65.1 ${\mu}m$ (CV:1.6%) shell. Furthermore, the multiple emulsions having different numbers of core were easily prepared by simple control of flow rates.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.867-873
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• 2023

In this study, for the purpose of standardized quality control of a cold medicine, we simultaneous analyzed four main chemical components of a cold medicine: acetaminophen, caffeine, methyl paraben, and propyl paraben. The sample was subjected to quantitative analysis using high performance liquid chromatography (HPLC), after pretreatment of four components. The experiment was carried out by using Isocratic elution at wavelength of 270nm. Acetonitrile and water (H₂O) were used as a mobile phase at a flow rate of 1.0mL/min in a commercial C18 reversed-phase column. A volume of 10uL cold medicine were injected into the column with column oven temperature at 35℃. As a result of the experiment, the values of Resolution were 4.983, 1.596, 5.519, and 1.678 respectively-well over Rs >1.5, which indicates that the separation of four components were efficient. In addition, value of symmetry factor of the components was 1.056, 1.069, 1.032, and 1.133 respectively, to show its symmetrical stability. The calibration curve of all four components exhibits good linearity with R² >0.9995 to 0.9999. Furthermore, the limit of detection(LOD) were between 0.0118 to 1.5973 mg/mL, while the limit of quantification (LOQ) were between 0.0353 to 4.7919 ㎍/mL with the recovery rate of 79.6% ~ 120.5%. The results of this study showed an efficient quality evaluation of a simultaneous analysis method for cold medicine components.

• Magazine of the Korea Concrete Institute
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• v.6 no.6
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• pp.151-158
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• 1994

In this work, in order to inrprove the flexural strength of hardened portlarid cerncrit paste, mix ing water was reduced to water ccrnent ratio of 0.1 aid water soluble polymer such as hydroxy propyl methyl cellulose was adclelri to the paste to obtain a better dispersion. The paste was kneaded by the twin roll mill for cornpact and homogeneous mixing. The high strength mechanism of the hardened cement paste may be due to the removal of macropores larger than 100${\mu}m$, the reduction of capillary pores acting as the passage of crack propagation, the increase of Young's moculus with iticrease of unhytlratcci cenxxnt ard the incicasc of fracture toughnevs with the crack toughening mechanism (grain bridging, polymer fibril bridging and fritional inter-locking).

• Food Science of Animal Resources
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• v.20 no.3
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• pp.199-206
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• 2000

축육 생산시 주요 부산물인 돼지 심장근으로부터 항산화제(0.02% propyl gallate, 0.2% asxorbic acid, 0.2% sodium tripolyphosphate) 첨가 세척액(25 mM phosphate buffer, pH 6.0)에 의해 제조된 surimi(5% protein 0.6 M NaCl, 25 mM phosphate buffer, pH 6.0)를 alginate(0.4%), calcium carbonate(0.075%) 및 lactate(0.6%) 등의 첨가에 의해 AC surimi 로 조제한 다음, CMC 또는 MC를 일정수준 (0.5%, 1.0%) 첨가하여 surimi 의 pH, 겔의 보수력과 조리 손실을 비롯하여 겔읨 루성을 비교 검톻였다. CMC 첨가시 pH는 0.2 단위씩 감소하는 경향을 보인데 비해 MC 첨가시에는 뚜렷한 변화를 보이지는 않았다. 조리 손실에 대한 영향을 살펴 본 결과 CMC와 MC 첨가구에서 0.5% CMC 첨가구를 제외하고서는 나머지 세 처리구에서 감소하는 경향이었고, 특히 MC 첨가시에는 대조구에 비해 뚜렷한 감소 경향을 나타내었으나(p<0.05) 첨가수준에 따른 차이는 나타나지 않았다 CMC나 MC의 첨가는 보수력에 대해서는 거의 영향을 미치지 않은 것으로 나타났고, 물성에 대한 측정 결과에서 CMC 첨가시에는 겔의 강도. 경도 및 탄성등은 약간 증가하였으나 유의적인 차이를 나타내지는 않았고 (P<0.05), MC 첨가시에는 뚜렷한 차이를 나타내지 않았으며, 겔 응집성에 대해서는 CMC와 MC 첨가에 의해 서로 다른 경향을 나타내었다.

• Bulletin of the Korean Chemical Society
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• v.16 no.6
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• pp.524-528
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• 1995

The reaction of [IrCl(cod)]2 with ppol ligand, Ph2PCH2CH2CH2P(Ph)CH2CH2CH=CH2, in ethanol gives an iridium complex, whose structure is converted from an ionic form, [Ir(cod)(ppol)]Cl·2C2H5OH (1),in polar solvents (ethanol, methanol and acetonitrile), to a molecular form, [IrCl(cod)(ppol)], in non-polar solvents (benzene and toluene). The cationic complexes, [Ir(cod)(ppol)]AsF6·1/2C2H5OH and [Ir(cod)(ppol)]PF6·1/2CH3CN, were prepared to compare with the ionic form by 31P NMR spectroscopy. When carbon monoxide is introduced to 1, cod is replaced by CO to give the 5-coordinated complex, [IrCl(CO)(ppol)]. Hydrogenation of 1-octene was not successful in the presence of 1. In order to verify the reason for 1 not behaving as a good catalyst for hydrogenation, electrophilic reactions with HCl, I2 and HBF4·etherate were performed, which yielded the oxidative addition product, [IrHCl2(ppol)], the substitution product, [IrI(cod)(ppol)], and another cationic product, [Ir(cod)(ppol)]BF4, respectively. Thus, the iridium complex is not sufficiently basic to activate hydrogen atoms or the olefin of the ppol ligand.

• Korean Journal of Food Science and Technology
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• v.24 no.3
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• pp.272-278
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• 1992

Takju, a Korean traditional wine, was prepared by using nuruk and Koji which were inoculated with Aspergillus kawachii and Aspergillus shirousamii. Those chemical composition such as alcohols and organic acids were determined with gas chromatography to investigate the variation of its content by the fermentation. Alcohol such as methyl, ethyl, n-propyl, i-butyl, i-amyl alcohol were detected in the most takju mash samples. Alcohol contents in the groups fermented with KNR and SNR were slightly higher than KKR, SKR groups. Lactic acid were concentrated and organic acids such as pyruvic, oxalic, malonic, succinic, maleic, malic, ${\alpha}-keto$ glutaric acid were also detected in the most samples. The pH was lowest in the KKR group. The total acid content was slightly decreased at the later fermentation and was highest in KKR. The content of minerals were highest in the WNR and BNR groups. Throughout fermentation the content of potassium and magnesium varied greatly with the tested groups.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.6 no.1
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• pp.41-46
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• 2000

The level of plasticizer such as diethyl phthalate (DEP), di-n-propyl phthalate (DprP), di-n-butyl phthalate (DBP), di-n-pentyl phthalate (DPP), butylbenzyl phthalate (BBP), di-(2-ethylhexyl) phthalate (DEHP), dicyclohexyl phthalate (DCHP) and di-(2-ethylhexyl) adipate (DEHA) was determined in disposable sanitary gloves. Samples of disposable sanitary gloves were taken at retail shops, and their overall extractions in carbon tetrachloride were measured, after establishment of soxhlet appratus in 6 hours. All of 8 samples of disposable sanitary gloves at retail shops were polyethylene (PE). All of the manufactures was voluntarily labelled their boxes of gloves in line Korea Food Code. The level of phthalate esters and DEHA in all of 8 samples were not exceed the detection limit. The detection limits of DEP, DprP, DBP, DPP, BBP, DEHP, DCHP and DEHA were 1.8, 1.9, 1.3, 1.1, 0.9, 0.7, 2.1 and 0.8 mg/L, respectively.

• Journal of Life Science
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• v.18 no.12
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• pp.1712-1717
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• 2008

Volatile flavor compounds of onions were analyzed and compared during storage at $0.5^{\circ}C$, which harvested in 6 regions, such as Muan, Buan, Andong and 3 regions of Changnyeong (Yueo, Jangma and Seongsan). A total of 45 compounds were detected in samples by solid phase microextraction (SPME)/GC/MSD, consisting mainly of sulfur-containing compounds (21), aldehydes (13), ketones (2) and miscellaneous compounds (9). The sulfur-containing compounds were major compounds with ranges of $66.9{\sim}86.9%$ of total volatiles in 0 day of storage as regardless of harvested regions. Three regions (Yueo, Seongsan and Muan) had high amounts of over 4,043 ng/g in 0 day of storage, whereas 2 regions (Muan and Yueo) only had amounts of over 2,400 ng/g after 60 days of storage. Five sulfur-containing compounds known as having antioxidant activity (2,4-, 2,5-dimetylthiophene, 2-vinyl-1,3-dithiane, 5-methoxy thiazole and 3,5-diethyl-1,2,4-trithiolane and isomer) were the high levels in 3 regions (Yueo, Seongsan and Muan) during 60 day of storage. These 3 regions had also the highest amounts in 5 sulfur-containing compounds known as having anticarcinogenic activity ((Z)-, (E)-methyl propenyl disulfide, (Z)-, (E)-propenyl propyl disulfide, and di-2-propenyl disulfide) and kept same trend after 60 days of storage.

• Journal of Microbiology and Biotechnology
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• v.18 no.3
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• pp.465-471
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• 2008

Highly active, stable, and magnetically separable immobilized enzymes were developed using carboxymethyl cellulose (CMC) and diethylaminoethyl cellulose DEAE-C; hereafter designated "DEAE" as supporting materials. Iron oxide nanoparticles penetrated the micropores of the supporting materials, rendering them magnetically separable. Lipase (LP) was immobilized on the surface of the supporting materials by using cross-linked enzyme aggregation (CLEA) by glutaraldehyde. The activity of enzyme aggregates coated on DEAE was approximately 2 times higher than that of enzyme aggregates coated on CMC. This is explained by the fact that enzyme aggregates with amine residues are more efficient than those with carboxyl residues. After a 96-h enantioselective ibuprofen esterification reaction, 6% ibuprofen propyl ester was produced from the racemic mixture of ibuprofen by using DEAE-LP, and 2.8% using CMC-LP.

• Textile Coloration and Finishing
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• v.6 no.4
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• pp.1-8
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• 1994

To improve the antimicrobial activity and crease resistance of Korean traditional Hansan ramie fabrics, partially saponified polyethylene(PPS) was used as a softening water repellent agent and 3-(trimethoxysilyl)propyl dimethyl octadecyl ammonium chloride(QAC) as a antimicrobial agent. The antimicrobial activity was effective by treatments of PPS, QAC and PPS/QAC for shake flask test. For the halo test, PPS/QAC showed good antimicrobial activity. It was found that the desirable composition of H$_{2}$O/PPS/QAC is 98/1/1 for improving the antimicrobial activity and crease resistance of the fabrics.