• Food Science and Biotechnology
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• v.17 no.3
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• pp.501-507
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• 2008

The quantitative structure-activity relationships (QSAR) study of antioxidative anthocyanidins and their glycosides were evaluated using 4 different assays of Trolox equivalent antioxidant capacity (TEAC), superoxide radical ($O_2^{{\cdot}-}$), hydrogen peroxide ($H_2O_2$), and peroxynitrite radical ($ONOO^-$) scavenging with TSAR software. Four models were developed with significant predictive values ($r^2$ and p value), which indicated that the antioxidant activities were mainly governed by the 3-dimensional structural energy (torsional energy), constitutional properties (the number of hydroxyl and methyl groups), and electrostatic properties (heat of formation, and dipole, quadrupole, and octupole components). This QSAR approach could contribute to a better understanding of structural properties of anthocyanidins and their glycosides that are responsible for their antioxidant activities. It might also be useful in predicting the antioxidant activities of other anthocyanins.

• Journal of the Korean Chemical Society
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• v.24 no.1
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• pp.73-79
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• 1980

N-Vinylurea(VU) was radically copolymerized with vinyl acetate (VAc). VU-vinyl alcohol (VA) copolymer, which is a water-soluble polymer with pendent urea and hydroxyl groups, was synthesized by the methanolysis of the VU-VAc copolymer.VU shows vinyl polymerization, and this result is in agreement with that of Nozakura, et al. Huggins constant for the aqueous solution of the VU-VA copolymer containing more than about 30 mole percent of VU was observed to be a high value.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.31-32
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• 2003

The fixation of reactive dyes onto cotton fabrics by means of dry heat treatment was examined in terms of water regain in fabrics. Dye liquors were applied to fabrics by ink-jet printer. The fixation strongly depended on water regain. At certain level of water regain the fixation showed stepwise increase. After this point the fixation reached to saturated value. The observed results were interpreted by the aggregation behavior of dyes and reactivity of hydroxyl group of cellulose depending on the amount of the surrounding water molecules. Urea molecules played a role of water at low water regain to increase the fixation.

• Textile Coloration and Finishing
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• v.11 no.6
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• pp.36-42
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• 1999

The antimicrobial activities of the copolymer of N,N'-dimethyl- N,N'-diallyl ammonium chloride(DMDAAC) and diallyl amino(DA) were investigated. The copolymer of DMDAAC and DA was prepared by free radical Polymerization through an intra-intermolecular propagation mechanism ie, cyclopolymerization. The copolymer was, then, reacted with cyanuric chloride for reactivity with hydroxyl group of cellulose. Cotton fabrics were finished by synthesized polymer, and their antimicrobial activities and fastness to launderings were tested. Dichlorotriazinyl DMDAAC-DA copolymer has MIC value of 1ppm against S. aureus and 10ppm against K pneumoniae. The antimicrobial fastness of the finished cotton to launderings were good enough to show colony reduction above 70% against S. aureus and K pneumoniae after 50 repeated laundering in anionic commercial detergent. Optimum treatment concentrations of the polymer were 0.5% in cold pad-batch method, and 0.1% in pad-dry method.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.9
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• pp.576-581
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• 2014

This study used the heat conductive silicone rubber sample of 0.95 mm thickness to research the properties of current by changing voltage. When the 1, 10, 30, 60, and 90 minute have passed, the running current has been measured through the applied voltage range of 200 V~800 V on setting temperature of $110^{\circ}C{\sim}170^{\circ}C$. As the temperature increased in applied voltage of 800 V, so did the current value according to time in proportion to the increasing temperature. In an analysis of FT-IR (fourier transform infrared) spectrum, the hydroxyl radicals group(O-H) was created by effects of the hydrogen that methyl group is eliminated by addition of the cross-linking agent peroxide.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.886-891
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• 2018

Colloid silica using as abrasive for polishing sapphire has been extensively studied, which mechanism has also been deeply discussed. However, by the requirement of application enlargement and cost reduction, some new problems appear such as silica service life time, particle diameter mixing, etc. In this paper, several influences of colloid silica usage on sapphire CMP are examined. Results show particle diameter and concentration, pH value, service life time, particle diameter mixing heavily influence removal rate. Further analysis discloses there are two main effect aspects which are quantity of hydroxyl group, contact area for abrasive density stacking between abrasive and sapphire. Based on the discussions, a dynamic process of sapphire polishing is proposed.

• Journal of the Microelectronics and Packaging Society
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• v.26 no.2
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• pp.23-29
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• 2019

Thermally expandable microsphere and aerogel composite was prepared by chemical compositization. Microsphere can produce synergies with aerogel, especially an enhancement of mechanical property. Through condensation between sulfonated microsphere and hydrolyzed silica sol, chemically-connected composite aerogel could be prepared. The presence of hydroxyl group on the sulfonated microsphere was observed, which was the prime functional group of reaction with hydrolyzed silica sol. Silica aerogel-coated microsphere was confirmed through microstructure analysis. The presence of silicon-carbon absorption band and peaks from composite aerogel was observed, which proved the chemical bonding between them. A relatively low thermal conductivity value of $0.063W/m{\cdot}K$ was obtained.

• Journal of Microbiology and Biotechnology
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• v.31 no.1
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• pp.33-42
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• 2021

Due to the potential of antioxidants to scavenge free radicals in human body, it is important to be able to prepare antioxidant peptides that meet the industrial requirements for cosmetics and food. Here, we determined in vivo/in vitro activities of antioxidant peptide from P. fucata (PFAOP) prepared by bio-fermentation method. The antioxidant property test results showed the DPPH, hydroxyl, superoxide radical-scavenging, and cellular antioxidant activity. EC50 values of PFAOPs were 0.018 ± 0.005, 0.126 ± 0.008, 0.168 ± 0.005, and 0.105 ± 0.005 mg/ml, respectively, exhibiting higher antioxidant activities than glutathione (p < 0.05). Moreover, anti-proliferation and cytotoxicity activity results illustrated PFAOP has a potent anti-proliferative activity against HepG2, Caco-2, and MCF-7 carcinoma cells with no cytotoxicity. Moreover, the protocols we developed in this work demonstrated several excellent advantages in PFAOP preparation compared to enzymatic hydrolysis or chemical synthesis methods and provide a theoretical foundation for higher-value application of marine-derived functional peptides.

• Food Science of Animal Resources
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• v.34 no.4
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• pp.533-542
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• 2014

This study was performed to investigate the effects of lemon balm (Melissa officinalis L.) on various quality and antioxidant activity of hamburger patties. Lemon balm extract (LBE) showed the highest amount of total polyphenol (801.00 mg TAE/g DW) and flavonoids (65.05 mg RA/g DW). The $IC_{50}$ value of DPPH hydroxyl scavenging of LBE was $132{\mu}g/mL$. The hamburger patties were prepared by 0% (N), 0.1% (L1), 0.5% (L2), and 1.0% (L3) of the lemon balm powder. The addition of lemon balm powder increased the chewiness value, but did not affect the hardness, cohesiveness, and springiness values. Lemon balm powder had positive effects on sensory evaluation of patties. The pH of all patties decreased with longer storage period. 2-Thiobarbituric acid value, volatile basic nitrogen content, and the total microbial counts of hamburger patties in the L3 group were lower, compared to those of the normal (N group). In conclusion, the L3 group had significantly delayed lipid peroxidation compared to other treatment groups. However, the addition of lemon balm powder into patties showed no significantly influence on proximate composition, calorie contents, water holding capacity and cooking loss of patties. Therefore, lemon balm might be a useful natural antioxidant additive in meat products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.8
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• pp.965-971
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• 2008

The antioxidant activities of hot water and ethanol extracts from fresh, steamed and black garlic were compared. The levels of phenolic compounds of extracts from fresh, steamed and black garlic were $0.81{\sim}0.99\;mg$/100 g and their contents were not significantly different. The contents of flavonoids in ethanol extracts, $0.96{\pm}0.05{\sim}1.06{\pm}0.09\;mg$/100 g, was higher than hot water extracts. DPPH radical scavenging activity was higher in ethanol extract. Although the highest level was $69.40{\pm}0.13%$ in concentration of 10 mg/mL from black garlic ethanol extract, ethanol extracts showed $50.55{\pm}1.40%$ in concentration of 15 mg/mL. Reducing power was significantly higher in black garlic extract and higher in the order of black garlic> fresh garlic> steamed garlic in ethanol extract. Hydroxyl radical scavenging activity was higher in ethanol extract, showing over 60% in concentration of 5 mg/mL. In oil emulsion, TBA value was significantly lower in hot water extracts from black garlic, however ethanol extracts were not significantly different. TBA value of ethanol extract were $1.49{\pm}0.08{\sim}2.11{\pm}0.16\;MA\;mg/kg$ and $1.33{\pm}0.18{\sim}1.62{\pm}0.19\;MA\;mg/kg$ from steamed and black garlic, respectively. Antioxidant activity to the linoleic acid was $72.71{\pm}2.17{\sim}88.74{\pm}3.70%$ in 1-day storage, but its level was increased at 4-day storage to $86.67{\pm}3.76{\sim}92.50{\pm}0.87%$.