• Conservation Science in Museum
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• v.16
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• pp.96-113
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• 2015

High-barrier films are used to store cultural heritage objects in a safe environment sealed from oxygen and moisture. One of the high-barrier films use populary E manufactured by Japanese company M from the 1990's. However, this product has stayed in wide use, due to dearth of research on related subjects - including studies comparing it with other similar products-, in spite of the fact that high price information about its characteristics and environmental conditions is largely lacking. This study examines the characteristics of a number of high-barrier films with the goal to establish environmental standards for safer conservation of cultural heritage objects. E by the Japanese manufacturer M is compared with four other films; an electronics packaging films by a Korean firm, a film specially produced for the purposes of experiment in this study and a zipper bag-type film. Experiments were performed to compare the properties and gas blocking ability of the films by looking at their cross-section and measuring the thickness, tensile strength, elongation, absorbance of UV and visible light, yellowing and the permeability for oxygen and vapor. Based on these experiments, there are observed changes under different environmental conditions and depending on the length of use through temparature and humidification reproucing test. The results showed that while the high-barrier film by the Korean manufacturer was suitable for use as a packaging material for cultural heritage objects, the zipper bag-type film (P) was ill-adapted for this purpose. Based on the experiments reproducing the real-world environment, the length of useful life was also determined for each.

• Korean journal of food and cookery science
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• v.28 no.6
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• pp.805-811
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• 2012

This study was carried out in order to optimize the manufacturing condition of fried garlic flakes as well as to investigate the physicochemical properties of the flakes. Fried garlic flake samples were prepared as follows: garlic was sliced by a thickness of 1.5 mm, 2.0 mm, 2.5 mm, which were measured by a thickness gage. The samples were fried in vegetable oil under different temperatures of $140{\sim}150^{\circ}C$, $160{\sim}170^{\circ}C$ and $180{\sim}185^{\circ}C$. The compression strength depending on the height (h) was measured in order to find the thickness effect by the rheometer (force control: 50 N, h: 3.25 mm). Moreover, the sample with 1.5 mm thickness showed crisp phenomena of the split compared with the crush shape of the 2.0 mm and 2.5 mm thick samples. The result of strength for time dependence showed a sample with a thickness of 1.5 mm, which was measured 5~9 times more than the 2.0 mm and 2.5 mm thick samples. We thought the reason that the 1.5 mm sample had less response power equivalent to compression force than the other samples. Alliin has been found to affect the immune responses in the blood, it is a derivative of the amino acid cysteine and is also quite heat stable. The LC system with a UV detection at 210 nm consists of a separation on a Zorbax TMS column and isocratic elution with water and ACN as a mobile phase. The alliin contents of raw and fried garlic flake under $140{\sim}150^{\circ}C$, $160{\sim}170^{\circ}C$ and $180{\sim}185^{\circ}C$ were 18.10 mg/mL, 14.0 mg/mL, 11.6 mg/mL and 11.1 mg/mL, respectively. The decrement of alliin content under different temperature was a small quantity hence, we confirmed that the increasing manufacturing temperature was not affected by the alliin content. Examining for the particle structure of fried garlic flakes by a polarization microscope, the color of the sample treated at $160{\sim}170^{\circ}C$ was pure yellow. Furder, the fiber shaped particle, which has an effect on the tough texture, almost did not appear compared to the different temperature conditions. Finally, the sensory test for the preference of fried garlic flake under different conditions was carried out and the scores for various sensory characteristics were surveyed. According to the physicochemical measurements and sensory evaluation, we confirmed that the optimum manufacturing condition of fried garlic flake was 1.5 mm thick at a temperature of $160{\sim}170^{\circ}C$.

• Korean Journal of Materials Research
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• v.23 no.12
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• pp.672-679
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• 2013

$Fe_4[Fe(CN)_6]_3$ coated on a mica or $TiO_2$/mica surface as infrared reflective blue pigment was prepared by a hydrothermal method. $Fe_4[Fe(CN)_6]_3$, used as coloring agent, was uniformly coated on mica or $TiO_2$/mica under the optimized condition of a 1.2 : 1 weight ratio between iron(III) chloride hexahydrate and potassium ferrocyanidetrihydrate at the initial pH level of 4.5 at $70^{\circ}C$. The infrared (IR)-reflective pigments were characterized by SEM, Zeta-potenial, FT-IR, and UV-VIS NIR spectrophotometry. Especially the CIE color coordinate and total solar reflectance(TSR) properties of the pigments were investigated in relation to variation of the coating and coated substrate thicknesses. Isolation-heat paint was prepared with 20 wt% blue pigments fully dispersed in acryl-urethane resin and several additives to coat the film uniformly. The films were also measured with CIE color coordinate, TSR, and the surface temperature was recorded by an isolation-heat measuring system. The pigments and films of $Fe_4[Fe(CN)_6]_3$ coated on mica and $TiO_2$/mica showed high TSR values compared with the TSR value of $Fe_4[Fe(CN)_6]_3$ itself. According to the increase of TSR value, the property of isolation-heat is effective. To realize the optimal blue color, we applied the the pigment to $TiO_2$ coated mica(TM(b)) which has blueish interference color. The pigment of $Fe_4[Fe(CN)_6]_3$ coated on TM(b) shows a strong blue color compared with that of $Fe_4[Fe(CN)_6]_3$ coated on $TiO_2$/Mmca(TM(w)), which has a whitish interference color.

• Journal of Soil and Groundwater Environment
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• v.20 no.4
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• pp.1-7
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• 2015

The degradation of off-flavors which is 2-Methylisoborneol (2-MIB) and geosmin by means of ultrasound (US) and pulsed ultraviolet (PUV) irradiation and its combination with catalyst (wire mesh, wire mesh coated TiO₂, and TiO₂) and additive (H₂O₂) were investigated via water system. A combination treatment of TiO₂ and H₂O₂ heterogeneity with US (24 kHz) and PUV (6000 W) has shown improved results in destroying 2-MIB and geosmin, which may be attributed to chain reactions by the enhanced formation of hydroxyl radicals (·OH) through H₂O₂ dissociation and reactive oxide ions of TiO₂ addition. Rapid degradation of off-flavors occurred within 2 min under PUV process with H₂O₂ 100 mg/L (81.5% for 2- MIB; 79.3% for geosmin) and TiO₂ 100 mg/L (83.7% for 2-MIB; 79.8% for geosmin), while compared with H2O2 100 mg/L (58.4% for 2-MIB; 58.0% for geosmin) and TiO₂ 100 mg/L (59.2% for 2-MIB; 38.5% for geosmin) within 5 min under US process. Surprisingly, the emphasis was given on the comparison with the same injected energies between PUV and US on degradation efficiency. Based on the injected energy comparison, the US provided better degradation performance under equal input power of 200 kJ with H₂O₂ 100 mg/L, while compared with H₂O₂ 100 mg/L under PUV process. Our findings suggest that US can be more effective compared to PUV for the degradation of off-flavors in aspect of energy consumptions.

• Horticultural Science & Technology
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• v.28 no.4
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• pp.685-690
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• 2010

Rubiadin, a major compound of noni ($Morinda$ $citrifolia$) adventitious root, is highly valued in pharmaceutical industry due to hepatoprotective activity. To dissect rubiadin's effective extraction condition, extraction process of noni adventitious roots was performed with different solvent types, ratio of water to methanol (water, 20, 40, 60, 80, and 100% of methanol), extraction time, and extraction method. In contrast, we also developed a reverse- phase HPLC assay method to determine rubiadin from noni adventitious roots. The HPLC assay of rubiadin was performed by C-18 column using a gradient solvent system of methanol and water with UV detector at 280 nm. The extraction efficiency of different types of solvents were increased in order of methanol (0.08%) > ethanol (0.05%) > acetonitrile (0.03%) > acetone (0.02%) and methylene chloride (0.02%). The results of rubiadin extraction using different solvents showed that 1 hour of ultrasonic extraction was effective in order of 60% methanol (0.21%) > 80% methanol (0.13%) > 100% methanol (0.07%), 40% methanol (0.07%) and 2 hours of reflux extraction was effective in order of 60% methanol (0.21%) > 40% methanol (0.17%) > 80% methanol (0.14%). To compare the extraction efficiency of rubiadin according to the extraction methods and time for high rubiadin content, the extracts of rubiadin in noni adventitious roots were isolated with the methods of ultrasonic extraction, shaking extraction and reflux extraction. Rubiadin extracted from the methods of ultrasonic waves and shaking displayed the highest contents at 8 and 24 hours, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.224-232
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• 2008

The health benefits associated with tea consumption have resulted in the wide inclusion of green tea extracts in botanical dietary supplements, which are widely consumed as adjuvants for complementary and alternative medicines. Tea contains polyphenols such as catechins or flavan-3-ols including (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin gallate (EGCG), as well as the alkaloid, caffeine. The contents of catechins and caffeine in green tea are considered as a standard of quality evaluation of green tea. Therefor, the purpose of this study was to investigate the most suitable HPLC condition for simultaneous determination of catechins and caffeine in green tea extracts. The efficient HPLC analytical condition of catechins and caffeine contained green tea extracts was developed. The gradient elution employed a $250\;mm\;{\times}\;4.6\;mm$ i.d. YMC-pak ODS-AM 303 column. The gradient system was used two mobile phases. A gradient elution was performed with mobile phase A, consisting of 0.1% aqueous phosphoric acid, and mobile phase B, comprising 100% MeOH, and delivered at a flow rate of 1 mL/min as follows: $0{\sim}25\;min$, 80% A; $26{\sim}50\;min$, $80{\sim}70%$ A; 51 min, 80% A. $51{\sim}55\;min$, 80% A. The UV detection wavelength was set at 280 nm. The limit of detection (LOD) for catechins and caffeine standards were under 50 ng/mL.

• Korean Journal of Materials Research
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• v.30 no.8
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• pp.383-392
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• 2020

In this paper, AgCl/Ag₃PO₄/diatomite photocatalyst is successfully synthesized by microemulsion method and anion in situ substitution method. X-ray diffraction (XRD), photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), and ultraviolet-visible spectroscopy (UV-Vis) are used to study the structural and physicochemical characteristics of the AgCl/Ag₃PO₄/diatomite composite. Using rhodamine B (RhB) as a simulated pollutant, the photocatalytic activity and stability of the AgCl/Ag₃PO₄/diatomite composite under visible light are evaluated. In the AgCl/Ag₃PO₄/diatomite visible light system, RhB is nearly 100 % degraded within 15 minutes. And, after five cycles of operation, the photocatalytic activity of AgCl/Ag₃PO₄/diatomite remains at 95 % of the original level, much higher than that of pure Ag₃PO₄ (40 %). In addition, the mechanism of enhanced catalytic performance is discussed. The high photocatalytic performance of AgCl/Ag₃PO₄/diatomite composites can be attributed to the synergistic effect of Ag₃PO₄, diatomite and AgCl nanoparticles. Free radical trapping experiments are used to show that holes and oxygen are the main active species. This material can quickly react with dye molecules adsorbed on the surface of diatomite to degrade RhB dye to CO₂ and H₂O. Even more remarkably, AgCl/Ag₃PO₄/diatomite can maintain above 95 % photo-degradation activity after five cycles.

• Journal of the Korean Applied Science and Technology
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• v.27 no.4
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• pp.559-567
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• 2010

In this study, the antioxidative effect, cellular protective effect and inhibitory effect on tyrosinase of Cosmos bipinnatus extracts were investigated. The ethyl acetate fraction of Cosmos bipinnatus flower extract ($11.48\;{\mu}g$/mL) showed more excellent free radical (1,1-diphenyl-2-picrylhydrazyl radical, DPPH) scavenging activity (FSC50) than those of leaf and stem extracts ($17.45\;{\mu}g$/mL). Reactive oxygen species (ROS) scavenging activity (OSC50) of Cosmos bipinnatus extracts on ROS generated in $Fe^{3+}$-EDTA/H2O2 system were investigated using the luminol-dependent chemiluminescence assay. The ethyl acetate fraction of Cosmos bipinnatus flower extract ($0.56\;{\mu}g$/mL) showed 3 times more excellent ROS scavenging activity than L-ascorbic acid ($1.50\;{\mu}g$/mL). The protective effects of the ethyl acetate fractions of extracts from different parts of Cosmos bipinnatus on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The ethyl acetate fractions of leaf and stem extract and flower extracts suppressed photohemolysis in a concentration dependent manner ($10\sim50\;{\mu}g$/mL). The inhibitory effect of ethyl acetate fraction of Cosmos bipinnatus flower extract ($62.75\;{\mu}g$/mL) on tyrosinase was investigated to assess the whitening efficacy. The ethyl acetate fraction of Cosmos bipinnatus flower extract showed 3.5 times higher tyrosinase inhibitory effect than arbutin ($226.88\;{\mu}g$/mL) known as an effective whitening agent. These results indicate that fractions of Cosmos bipinnatus extracts can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging $^1O2$ and other ROS, and protect cellular membranes against ROS. Fractions of Cosmos bipinnatus extracts can be applicable to new functional cosmetics for antioxidant and whitening.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.3
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• pp.213-217
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• 2001

In order to develop a new separation technology, supercritical fluid extraction process was used to produce high purity pigments and fatty acids from seaweed (Undaria pinnatifida). Supercritical carbon dioxide was used as a solvent and ethanol as an entrainer. The sample was treated by a frozen drier and experiments were conducted with a semi-batch flow system at various operating conditions (pressure range, $10.3\~17.2$ MPa; temperature range, $30\~45^{\circ}C$: particle size, $500\~1,000{\mu}m$ extraction time, 60 min). Characteristics of the recovered pigment (chlorophyll a) and fatty acids were determined by UV-spectrophotometry and gas chromatography, respectively. The highest extraction efficiency for fatty acids and pigments was achieved at 12.4 MPa, $35^{\circ}C$, $500{\mu}m$of seaweed size.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.2
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• pp.61-67
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• 2007

In this study, the antioxidative effects of Equisetum arvense extracts were investigated. The free radical (1,1 diphenyl-2-picrylhydrazyl, DPPH) scavenging activity ($FSC_{50}$) of extract/fractions of Equisetum arvense was in the order: 50 % ethanol extract ($182.04{\mu}g/mL$) < ethylacetate fraction ($54.50{\mu}g/mL$) < deglycosylated flavonoid aglycone fraction ($14.13{\mu}g/mL$). Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of some Equisetum arvense extracts on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system were investigated using the luminol- dependent chemiluminescence assay. The order of ROS scavenging activity was deglycosylated flavonoid aglycone fraction ($OSC_{50}$, $3.54{\mu}g/mL$) < 50 % ethanol extract ($0.80{\mu}g/mL$) < ethylacetate fraction ($0.006{\mu}g/mL$). Ethylacetate fraction showed the most prominent scavenging activity. The protective effects of extract/fractions of Equisetum arvense on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The ethanol extract (50%) suppressed photohemolysis in a concentration dependent manner, particularly deglycosylated aglycone extract exhibited the most prominent celluar protective effect ($\tau_{50}$, 161.10 min at $10{\mu}g/mL$). These results indicate that extract/fractions of Equisetum arvense can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS.