• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.3
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• pp.327-332
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• 2012

In other to promote the utilization of native Gwangyang Rubus coreanus Miq. as an antioxidant material in functional food, its general composition, free sugars, vitamin C, vitamin E, and anthocyanin content were examined. Free sugars were mainly $2.83{\pm}0.01%$ glucose and $3.49{\pm}0.17%$ fructose. Native Gwangyang Rubus coreanus Miq. included higher vitamin C (0.04 g/100 g) and E (0.04 g/100 g) contents than other Rubus coreanus Miq. Anthocyanin was detected to be 2.41 g/100 g. Two extracts from native Gwangyang Rubus coreanus Miq., hot water extract (RCW) and 80% ethanol extract (RCE), were prepared by reflux, filter, and freeze-dry. The phenolic compound levels of RCW and RCE were 5.99% and 6.20%, respectively. In DPPH- and ABTS-radical scavenging activities, and lipid peroxidation formation inhibitory activity, RCE exhibited relatively high activities when compared to RCW (89.29% vs. 65.04%, 47.65% vs. 30.22%, 23.27% vs. 3.6%, respectively). Based upon these results, it is suggested that RCE from native Gwangyang Rubus coreanus Miq. possesses the antioxidant potentials for radical scavenging and anti-lipid peroxidation activities.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.575-581
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• 2020

A colorless antistatic agent was prepared for use in antistatic films for liquid crystal displays (LCDs) requiring low surface resistance and high transmittance. Among various lithium-fluoro compounds and quaternary ammonium salts, antistatic materials were selected based on their electrical conductivity, and antistatic agents were prepared to measure the surface resistance. As a result, the material with high conductivity showed a relatively low surface resistance, i.e., relatively good antistatic performance. Based on the antistatic materials selected, the formulation ratio for producing the best antistatic agent was established through the experimental design method and the effects of each factor were analyzed. The higher the use of lithium- fluoro compounds as antistatic materials, the higher the ratio of oligomer use with multi-functional groups, and the smaller the surface resistance. The quaternary ammonium salts increased the antistatic performance of the lithium-fluoro compounds, but the effects of the amount used were not relatively large. After manufacturing the antistatic PET film, the properties of the antistatic film showed low surface resistance values (<10⁹ Ω/sq.), high permeability (>92%), low haze (<0.5%), and high whiteness (L^⁎>95). In addition, the antistatic film reliability was found to be excellent by showing a stable surface-resistance change rate of less than 10%, even under high temperature and high humidity conditions.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.6
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• pp.155-162
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• 2012

When RC (Reinforced Concrete) structures are exposed to sea water, steel corrosion can occur and this leads a degradation of structural performance. Referring the electro-deposition system with sea water from the 1st step research, durability and structural performance are evaluated in coated steel and RC members containing it in the 2nd research. In the durability performance test, Half Cell Potential test is performed and the coated steel is evaluated to have the high resistance to corrosion, which shows only 35% of corrosion velocity in normal (bare) steel. In the structural performance test, tensile strength, adhesive strength, and flexural/shear in RC member are performed. For the electro-deposit coated steel, increasing ratios of 3.2% and 8.8% are evaluated in the test of tensile strength and adhesive strength, respectively. For the structural test in RC member, there is no big difference between RC members with coated and non-coated steel in ultimate load and failure pattern It is evaluated that the chemical compound with $CaCO_3$ and $Mg(OH)_2$ from electro-deposition causes slightly increased structural performance. The electro-deposit coated steel can be more widely applied after performance verification from several tests like fatigue, resistance to impact, and long term-submerging test.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.6
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• pp.683-688
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• 2007

Total polyphenolic compounds, DPPH radical scavenging activity, superoxide dismutase (SOD), vitamin A, C, E, flavonoid and anthocyanin of Rubus coreanus Miquel during maturation were investigated to expand the utilization of Rubus coreanus Miquel as functional food material. Physiological activities of unripened, middle-ripened and ripened fruit of Rubus coreanus Miquel were examined. The ripened fruit included higher contents of total polyphenolic compound compared with those of the other sample groups, unripened and middle-ripened fruit. SOD of unripened, middle-ripened and ripened fruit were 59.15, 80.05 and 95.03%, respectively. Scavenging concentration ($SC_{50}$) of unripened and middle-ripened fruit for 0.4 mM DPPH (1,1-diphenyl 2-picryl hydrazyl) was 2.3 mg/mL by weight, but only 1.6 mg/mL for ripened fruit. The vitamin A content of the Rubus coreanus Miquel was found to be lower as the fruit ripened; however, vitamin E showed the reverse pattern. In addition Rubus coreanus Miquel is a fruit which has a high vitamin C content regardless of maturity. The flavonoid contents of Rubus coreanus Miquel were in order of ripened fruit ($49{\mu}m/mg$)>middle-ripened fruit ($16.4{\mu}m/mg)$>unripened fruit ($15.4{\mu}m/mg$). Also, the contents of anthocyanin in ripened fruit were $394.50{\mu}m/mg$, which were higher than those of middle-ripened ($12.43{\mu}m/mg)$ and unripened fruit ($7.89{\mu}m/mg$).

• Analytical Science and Technology
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• v.15 no.4
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• pp.329-334
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• 2002

Tributyl phosphate(TBP) is used in solvent extraction process for radioactive waste. This compound may be degraded to dibutyl phosphate($DBP^-$), monobutyl phosphate($MBP^{2-}$) and ${PO_4}^{3-}$ by radioactive material. Amount of $DBP^-$ and $MBP^{2-}$ in TBP must be monitored because they production of these compounds means degradation of which leads to a decrease in the extraction yield. Retention behavior for $DBP^-$, $MBP^{2-}$, $F^-$, $Cl^-$, ${NO_2}^-$, ${NO_3}^-$, ${SO_4}^{2-}$ and ${PO_4}^{3-}$ are studied with AS4A-SC(Dionex) analytical column and $Na_2CO_3$/NaOH eluent by Ion chromatography. Optimum condition for these anions is 2 mM $Na_2CO_3$/1 mM NaOH eluent. All anions by this condition is well separated within 15min. Dynamic range is $10{\mu}g/mL$ - $100{\mu}g/mL$ for DBP and $5{\mu}g/mL$ - $50{\mu}g/mL$ for $MBP^{2-}$, respectively. The Detection limit for AS4A-SC are $1{\mu}g/mL$ for $DBP^-$ and $0.5{\mu}g/mL$ for $MBP^{2-}$ in this system with a $25{\mu}L$ sample loop.

• Analytical Science and Technology
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• v.9 no.4
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• pp.382-391
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• 1996

In this study, 12 different chemical species of fine ceramic($BaTiO_3$) were synthesized as the standard materials for the fast and accurate measurements of X-ray fluorescence spectrometry. Samples were diluted to sixteen times with the filling compound ($Li_2B_4O_7+LiBO_2$) in order to remove the matrix effect, and to get the convenient storage and homogeneity of ingredients. The matrix effects among the ingredients were corrected by the empirical coefficient method based on the Lucas-Tooth and Price model. The standard curve on 12 standard materials containing 15 elements were obtained by using X-ray fluorescence spectrometry at three different laboratories. The correlation factors of BaO, PbO, SrO, $Fe_2O_3$, $La_2O_3$, $SnO_2$, ZnO, $ZrO_2$, CaO indicated the relati vely good agreement over 0.995 among the three different laboratories. $SiO_2$ and $Al_2O_3$ showed the poor linearity because of their low fluorescence intensities.

• Journal of the Korean Society of Radiology
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• v.14 no.2
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• pp.149-155
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• 2020

Most of radiation protection clothing is made of lead with excellent radiation shielding because it has excellent process ability and economic efficiency and has a high atomic number. However, lead is classified as a hazardous heavy metal, and there is a risk of lead poisoning. Recently, research to replace lead has been actively conducted. In this study, a research on a shielding sheet with improved physical properties while maintaining the radiation shielding ability equivalent to that of conventional materials by mixing two materials that are harmless to the human body, such as BaSO₄ and Bi₂O₃, and a silicone material binder Was performed. For comparison evaluation with the existing lead shielding sheet, the shielding rate was evaluated using a 40 degree shielding sheet having the highest porosity. As a result, it was analyzed that the shielding rate was superior to 9 % or more at the same thickness. In addition, as a result of studies to improve the physical properties of the shielding sheet, it was analyzed that the shielding sheet mixed with BaSO₄/nylon/Bi₂O₃ was the best.

• 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.

• Applied Chemistry for Engineering
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• v.20 no.6
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• pp.653-657
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• 2009

Nitrous oxide is a typical greenhouse gas which is produced from various organic or fossil fuel combustion processes as well as chemicals producing plants. $N_2O$ has a global worming potential of 310 times that of $CO_2$ on per molecule basis, and also acts as an ozone depleting material in the stratosphere. However, its removal is not easy for its chemical stability characteristics. Most SCR processes with several effective reducing agents generally require the operation temperature higher than $450^{\circ}C$, and the catalytic conversion becomes decreased significantly when NOx is present in the stream. Present experiments have been performed to obtain basic design data of actual application concerning the effects of $SO_2$ and $NH_3$ on the interim and long term activities of $N_2O$ reduction with CO over the mixed metal oxide (MMO) catalyst derived from a hydrotalcite-like compound precursor. The MMO catalysts used in the experiments, have shown prominent activities displaying full conversions of $N_2O$ near $200^{\circ}C$ when CO is introduced. The presence of $SO_2$ is considered to show no critical behavior as can be met in the $NH_3$ SCR DeNOx systems and the effect of $NH_3$ is considered to play as mere an impurity to share the active sites of the catalysts.

• Korean journal of food and cookery science
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• v.20 no.2
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• pp.204-210
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• 2004

This study was performed to provide basic physiological activities data to predict the usefulness of olive leaves as a food material. Total flavonoid and total phenol contents of 80% ethanol extract of olive leaf were 5.81% and 14.8%, respectively. Total flavonoid and total phenol contents were markedly higher in butanol and ethyl acetate fractions than in hexane, chloroform, and water fractions (p＜0.05). Oleuropein in olive leaf was the major phenolic compound. The oleuropein contents of 80% ethanol extract, butanol and ethyl acetate fractions of olive leaf were 102.11${\pm}$0.02, 173.35${\pm}$0.03 and 152.71${\pm}$0.03 mg/100g, respectively. The 80% ethanol extract, butanol and ethyl acetate fractions of olive leaf showed a growth inhibitory effect to Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Salmonella enteritidis, whereas antimicrobial activities of hexane and chloroform fractions were not observed. The inhibitory activity to ACE was determined to be very weekly positive in 80% ethanol extract and all fractions of olive leaf. The nitrite-scavenging ability of 80% ethanol extract, butanol and ethyl acetate fractions of olive leaf were 72.8%, 76.0% and 75.4%, respectively. Significant evidence was detected that the butanol and ethyl acetate fractions showed higher activity than that of hexane, chloroform, and water fractions (p＜0.05).