• Polymer(Korea)
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• v.27 no.5
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• pp.464-469
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• 2003

In this work, the fragrant oil release behavior of poly($\varepsilon$-caprolactone) (PCL) microcapsules containing SiO$_2$ was investigated. The SiO$_2$ was chemically treated in 10, 20, and 30 wt% hydrochloric acid and sodium hydroxide. The acid and base values were determined by Boehm's titration technique and $N_2$/77 K adsorption isotherm characteristics, the specific surface area and total pore volume were studied by BET. The PCL microcapsules containing SiO$_2$ and fragrant oil were prepared by oil-in-water (o/w) emulsion solvent evaporation method. The shape and surface of PCL microcapsules were observed using image analyzer and scanning electron microscope (SEM). The fragrant oil release behavior of PCL microcapsules was characterized using UV/vis. spectra. The average diameters of PCL microcapsules were decreased from 35 to 21 $\mu$m with increasing stirring rate. It was found that in the case of acidic treatment the fragrant oil adsorption capacity and release rate were increased due to the increase of specific surface area and acid value. In the case of basic treatment, the fragrant oil adsorption capacity and release rate were decreased due to the decrease of sp ecific surface area and the increase of acid-base interactions between SiO$_2$-NaOH and fragrant oil with increasing base value of SiO$_2$.

• Korean Journal of Food Science and Technology
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• v.40 no.5
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• pp.510-515
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• 2008

Microwave energy was applied to the extraction of functional catechins from grape seed. The solvent, absolute ethanol, reached the boiling point when exposed for less than 3 min microwave treatment at 100 W. The effects of independent variables in microwave-assisted extraction (MAE), including microwave power (0-160W, $X_1$), ethanol concentration (0-100%, $X_2$) and extraction time (1-5 min, $X_3$), were investigated on each response variable ($Y_n$), and the contents of catechin and its derivatives were determined via response surface methodology, thereby allowing us to predict their optimal extraction conditions. The predicted maximal values of (+)-catechin, procyanidin $B_2$, (-)-epicatechin, and (-)-epicatechin gallate were 137.99, 72.78, 222.38, and 9.59 mg%, respectively, under different MAE conditions. The predicted extraction conditions for maximum catechin responses were as follows: 104.10 W of microwave power, 45.35% of EtOH, and 4.89 min of extraction time for (+)-catechin (137.99 mg%), 133.16 W, 46.16% and 4.49 min for procyanidin $B_2$ (72.78 mg%), 136.00 W, 41.37% and 4.39 min for (-)-epicatechin (222.38 mg%), 143.20 W, 37.51% and 1.88 min for (-)-epicatechin gallate (9.59 mg%), respectively. The contents of (+)-catechin, procyanidin 1B2 and (-)-epicatechin in MAE were similarly influenced by three independent variables, whereas (-)-epicatechin gallate was influenced less profoundly by ethanol concentration and extraction time.

• Journal of the Microelectronics and Packaging Society
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• v.23 no.3
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• pp.51-56
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• 2016

To fabricate a copper (Cu)-based fine conductive filler having antioxidation property, submicron silver (Ag)-coated Cu particles were fabricated and their antioxidation property was evaluated. After synthesizing the Cu particles of $0.705{\mu}m$ in average diameter by a wet-reduction process, Ag-coated Cu particles were fabricated by successive Ag plating using ethylene grycol solvent. Main process parameters in the Ag plating were the concentration of reductant (ascorbic acid), the injection rate of Ag precursor solution, and the stirring rate in mixed solution. Thus, Ag plating characteristics and the formation of separate fine pure Ag phase were observed with different combinations of process parameters. As a result, formation of the separate pure Ag phase and aggregation between Ag-coated Cu particles could be suppressed by optimization of the process parameters. The Ag-coated Cu particles which were fabricated using optimal conditions showed slight aggregation, but excellent antioxidation property. For example, the particles indicated the weight gain not exceeding 0.1% until $225^{\circ}C$ when they were heated in air at the rate of $10^{\circ}C/min$ and no weight gain until 75 min when they were heated in air at $150^{\circ}C$.

• Membrane Journal
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• v.34 no.1
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• pp.79-86
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• 2024

The flat sheet membrane, one of the representative forms of polymeric membranes, is widely used from material research in laboratories to commercial membrane production due to its ease of fabrication. Porous polymeric flat sheet membranes used in microfiltration and ultrafiltration are mainly fabricated through phase separation processes, utilizing non-solvent-induced and vapor-induced phase separation methods. However, due to the nature of phase separation processes, variations between samples can easily occur depending on the surrounding environment and the experimenter, making it difficult to ensure reproducibility. Therefore, for scaling up and ensuring reproducibility of developed membrane fabrication technologies, there is a need for a controlled environment continuous large-area production device, such as a roll-to-roll manufacturing system. This research compared the changes in membrane characteristics due to differences in manufacturing environments when scaling up laboratory-scale fabrication technologies to roll-to-roll processes using knife and slot die coaters. By optimizing the continuous manufacturing process factors, uniformity of the membrane was ensured during large-area production.

• Korean journal of food and cookery science
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• v.27 no.3
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• pp.21-28
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• 2011

In this study, we analyzed flower tea activity against oral bacteria. Lagerstroemia indica, Paeonia suffruticosa and Hemerocallis fulva showed high extract yields. Bellis perennis, Punica granatum and Cercis chinensis showed the high rates of yield by ethanol extraction. Extract yield seemed to be related to the characteristics of the specimens rather than to the solvent. Streptococcus mutans, Streptococcus obrinus, Porphyromonas gingivalis and Prevotella intermedia were used to investigate extracts activity against bacteria; the former two cause dental caries and the latter two cause halitosis. Cornus officinalis, L. indica, P. granatum and P.s uffruticosa showed high antibacterial activities against S. mutans. In specimens extracted with ethanol, P. suffruticosa, Camellia sinensis, Camellia japonica L. and Rosa hybrida showed high antibacterial activities. L. indica, P. granatum and C. officinalis showed high antibacterial activities against S. sobrinus. C. officinalis, P. granatum, L. indica and P. suffruticosa showed high activities for specimens extracted with ethanol. The results show that the warm extracts of C. officinalis, L. indica and P. granatum may be effective to prevent dental caries. In particular, the ethanol-based extracts of C. officinalis, P. suffruticosa and C. sinensis were effective to prevent dental caries and thus may be highly marketable. Chrysanthemum zawadskii, R. hybrida, P. granatum, C. japonica L. and Zinnia elegans showed high antibacterial activity against P.gingivalis. R. hybrida showed the highest ethanol extract activity, followed by P. suffruticosa, P. granatum, C. japonica L. and L. indica. R. hybrida, P. granatum, C. morifolium and C. japonica showed high activity against Pr.intermedia in the order named. C. zawadskii, P. granatum, L. indica, C. japonica and A. princeps showed high ethanol extract activity. Thus, the warm extracts of R. hybrida, P. granatum and C. japonica may be helpful to reduce halitosis. In addition, the ethanol-based extracts of P. granatum, C. japonica and L. indica are expected to be highly marketable as mouthwashes.

• Korean Journal of Food Science and Technology
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• v.40 no.5
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• pp.497-502
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• 2008

The volatile components in Gamdongchotmoo kimchi, unfermented and fermented for 3 or 25 days, were extracted via solvent-assisted flavor evaporation (SAFE), and then analyzed via gas chromatography/mass spectrometry (GCMS). A total of 57 components, including 14 S-containing compounds, 22 terpene hydrocarbons, 13 aliphatic hydrocarbons, 4 alcohols, and 4 miscellaneous components, were detected in Gamdongchotmoo kimchi. Among them, the S-compounds were quantitatively dominant. The aroma-active compounds were also determined via gas chromatography-olfactometry (GC-O), using aroma extract dilution analysis (AEDA). A total of 16 aroma-active compounds were detected via GC-O. The most intense aroma-active compounds in Gamdongchotmoo kimchi included 4-isothiocyanato-1-butene ($Log_3$ FD factor 7, rancid), an unknown($Log_3$ FD factor 7, spicy) and another unknown ($Log_3$ FD factor 7, seasoning-like). In addition, other aroma-active compounds, including dimethyldisulfide ($Log_3$ FD factor 6, rotten onion-like/sulfury), 2-vinyl-[4H]-1,3-dithiin ($Log_3$ FD factor 5, spicy/garlic-like), and an unknown ($Log_3$ FD factor 5, rancid/cheese-like) might be crucial to the flavor characteristics of Gamdongchotmoo kimchi.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.7
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• pp.983-992
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• 2015

This study investigated the quality characteristics and biological activities, such as antioxidant, whitening, anti-diabetes, and anti-inflammatory activities, of yellow garlic, by simplify processing time and manufacturing process compared with black garlic. Extracts were prepared various ratios of water and ethanol solvent [water : ethanol (v/v)=100:0, 70:30, 50:50, 30:70, 0:100] from yellow garlic. Alliin content of yellow garlic showed no difference compared with fresh garlic, whereas S-allyl cysteine content of yellow garlic was higher than that of fresh garlic. Alliin content of yellow garlic extracts increased in an ethanol concentration-dependent manner. Total phenol and flavonoid contents were highest in 100% ethanol extract. DPPH and ABTS radical scavenging abilities did not show significant differences among 0~70% ethanol extracts, whereas 100% ethanol extract showed the highest contents of 93.45% and 91.46%, respectively. Tyrosinase and ${\alpha}$-glucosidase inhibitory activities were also highest in 100% ethanol extract, but did not show significant differences among the extract solvents. Water and ethanol extracts from yellow garlic showed anti-inflammatory effects by modulating production of NO and cytokines at a concentration of $100{\mu}g/mL$. We suggest that yellow garlic has antioxidant, whitening, anti-diabetes, and anti-inflammatory activities and can be used as a functional material similar to black garlic.

• Polymer(Korea)
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• v.27 no.1
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• pp.9-16
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• 2003

Ipriflavone (IP) stimulates proliferation and differentiation of osteoblast and also enhances calcitonin secretion in the presence of estrogen. Poly(lactide-co-glycolide) (PLCA) due to its controllable biodegradability and relatively good biocompatibility is one of the most significant candidates for the study of drug controlled release system. In this study, IP-loaded PLGA microspheres (MSs) was prepared by using conventional O/W solvent evaporation method. The size of MSs was in the range of 5~200 $mu extrm{m}$. The morphology of MSs was characterized by SEM. And, in vitro release amounts of IP were analyzed by HPLC. The highest encapsulation efficiency were obtained by using gelatin and polyvinyl alcohol (PVA) as emulsifiers. The morphology, size distribution, and in vitro release pattern of MSs were changed by several preparation parameters such as molecular weights (8, 20, 33 and 90 kg/mol), polymer concentrations (2.5, 5, 10 and 20%), emulsifier types (PVA, gelatin and Tween 80), initial drug loading amount (5, 10, 20 and 30%) and stirring speed (250, 500 and 1000 rpm). The release of IP in vitro was more prolonged over 30 days, with close to zero-order pattern by controlling the preparation parameters. The physicochemical properties of IP-loaded PLGA MSs were investigated by XRD and DSC.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.590-595
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• 1995

To examine the characteristics of antioxidative compounds from Capsella bursa-pastoris, ethanol extracts were separated into five organic solvent fractions; hexane(Fr.H), diethyl ether (Fr.E), ethyl acetate(Fr.EA), butanol (Fr.B), and water(Fr.D) fractions. Fr.B showed the greatest electron donating ability and inhibitory effect on lipid peroxidation. Whereas Fr.E had the most excellent activity in the superoxide radical scavenging activity by xanthine/xanthine oxidase-cytochrome c reduction system. The inhibitory effect of each fraction on xanthine oxidase was also measured. Fr.E had the strongest inhibitory effect on xanthine oxidase and $IC_{50}$ was $5.65\;{\mu}g$. The results indicate that the superoxide radical scavenging activity of Fr.E is caused by the inhibitory effect on radical generating system of xanthine oxidase. Also the order of inhibitory effect on xanthine oxidase was Fr.B

• Membrane Journal
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• v.13 no.3
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• pp.162-173
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• 2003

The pseudo n-type polyaniline was prepared by doping of camphorsulfonic acid(CSA) and dodecylbenzenesulfonic acid(DBSA) as the dopants in solvent of N-methyl-2-pyrrolidinone(NMP). The dopants in polymer structure was qualitatively analyzed using FT-IR. The influence on electrochemical properties with dopant concentration of PANI film were investigated. The electrochemical characteristics of the n-type PANI electrode that coated on ITO were evaluated by cyclic voltammetry(CV) and AC impedance method. The prepared PANI were confirmed as n-type PANI from FT-IR and CV. The charge transfer resistance of film on PANI/CSA electrode were measured as 1.14{\sim}1.09k{\mu}$by AC impedance. The charge transfer resistance of PANI/DBSA electrode decreased with increasing the mole ratio of DBSA as 27.73{\sim}8.37 k{\mu}$. The double layer capacitance of PANI/CSA electrode was showed almost constant value as $13.47{\sim}14.59 {\mu}F$ and that of PANI/DBSA electrode increased with increasing mole ratio of DBSA from 0.49 to $1.20 {\mu}F$.