• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.5
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• pp.695-701
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• 2015

This study was conducted to evaluate the effects of drying and extraction methods on antioxidant activity and total phenol content of Gnaphalium affine D. DON (GA). Hot-air, shade-drying, and freeze-drying were used for drying, after which magnetic stirring and ultrasonification were applied. Extracting solvents were water, 80% ethanol, and 80% methanol. Total phenol content was highest in 80% ethanol extract of freeze-dried and stirred GA. Total flavonoid content was highest in 80% methanol extract of freeze-dried and stirred GA. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was higher in 80% methanol and 80% ethanol extracts than in water extract. 2,2-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity was highest in 80% ethanol extract of shade-dried and ultrasonicated GA. Reducing power was generally higher in 80% methanol extract than in 80% ethanol and water extracts of GA. Total phenol and total flavonoid contents were highly correlated with DPPH radical scavenging activity and reducing power, respectively. This result implies that the antioxidant activity of GA can be attributed to phenol compounds such as flavonoids. Conclusively, phenol compounds such as flavonoids are responsible for the antioxidant activity of GA, and there was no significant effect of drying and stirring conditions on antioxidant activity of 80% ethanol. Meanwhile, DPPH radical scavenging activity of water extract and reducing power of 80% methanol extract were higher in hot-air and shade-dried GAs than in freeze-dried GA.

• Bulletin of the Korean Chemical Society
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• v.30 no.9
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• pp.2032-2038
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• 2009

The amount of phenol and NaOH for the colorimetric determination of ammonia in Korean standard methods (KSM) is found to be highly excessive compared to the standard methods of several other countries. The absorbance of indophenol formed by the Berthelot reaction for ammonia analysis was measured under the various reaction conditions classified in experiment groups 1, 2, 3, 4 and KSM and American standards methods (ASM), and the relationships between the absorbance of indophenol and concentration of ammonia were compared. The amount of phenol can be reduced to 10 g (current 25 g in KSM) and NaOH can be reduced to 1.76 g (current 11 g in KSM) for the preparation of 200 mL phenate solution, and the absorbance sensitivity increased. The concentration of the phenol and NaOH correlatively affect the pH of the solution, which is a critical variable in achieving the maximum sensitivity and rapid and stable color development.

• Journal of Photoscience
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• v.10 no.3
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• pp.231-236
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• 2003

TiO$_2$ has been used as photocatalyst since two and half decades ago. The efficiency in its photocatalytic reactions has been improved by increasing the surface area of the photocatalyst by supporting fine TiO$_2$ particles on some porous materials. In this work, heteropolytungstic acid (HPA) - encapsulated into the titanium exchanged SBA-15 mesoporous materials (TiSBA-15) were prepared and characterized. Also their photocatalytic effects on decomposition of phenol were investigated and the photodecomposition rates of the phenol were observed to be increased by 2.5 8 fold, as compared to those observed in the presence of HPA-encapsulated SBA-15 or TiSBA-15 without HPA.

• Archives of Pharmacal Research
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• v.14 no.3
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• pp.249-254
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• 1991

Activated carbons from rice-straw can be used as an adsorbents for the purification of water were prepared and evaluated. The adsorptive capacities of activated carbons were measured by iodine, potassium permangante, phenol and metals. It was observed by electron microscope (SEM) and IR spectrum that organic components in the rice-straw and its carbonization product were disappeared. Slit-shaped and porousstructures were formed by activation. There was no relationship between temperature and adsorption of iodine but adsorption of potassium permanganate increased as temperature rose. The adsorption of the phenol was greater than 99%. The adsorption data of phenol at $25^\circ{C}$ obeyed the Freundlich's isotherm. Various metals except sodium were not removed by activated carbon.

• International Journal of Advanced Culture Technology
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• v.3 no.1
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• pp.86-89
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• 2015

Sugar cane, renewable fiber resources, were used for roof tile production. Urea formaldehyde, phenol formaldehyde and isocyanate resin were used as binders in this study. Roof tile specimens with 400 mm wide, 400 mm long and 5 mm thick were prepared by compression molding. Physical and mechanical properties of the specimens were analyzed by water absorption, thickness swelling, thermal conductivity, density, modulus of rupture and modulus of elasticity. From the results, water absorption at 1 and 24 hours was 19-47 % and 38-57 %, respectively. Thickness swell at 24 hours was 15-29%. Thermal conductivity was 0.016, 0.017 and 0.019 W/m.K when using isocyanate, urea formaldehyde and phenol formaldehyde, respectively. Density of the specimens was 770-860 kg/m3. Modulus of rapture was 255-280 MPa. Modulus of elasticity was 5.1-7.6 GPa. Physical and mechanical properties of the specimens indicated that they would be applied for roof tile and construction.

• Journal of Food Hygiene and Safety
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• v.29 no.1
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• pp.21-25
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• 2014

Formaldehyde and phenol used in the production of melamine-wares may be intended to come into foodstuffs. So this study investigated the migration of formaldehyde and phenol from 222 articles Articles were cups(14), bowls(75), plates(85), spoons(10), chopsticks(4), food trays(8), rice paddles(4), spatulas(9) and scoops(12). The food stimulants were 4% acetic acid, 20% ethanol, distilled water and n-heptane. Korea regulation (Standards and specifications for food utensils, containers and package) specifies migration limits for formaldehyde and phenol in food stimulants. Formaldehyde and phenol are restricted by 4 mg/L, 5 mg/L respectively. In all cases the migration of formaldehyde and phenol were below the limit set in Korea regulation. The level of formaldehyde and phenol migrated to food simulants were in the range of N.D~2.949 mg/L, N.D~0.078 mg/L respectively. These migration results of formaldehyde and phenol will provide a scientific basis for the safety management of melamine-wares.

• Journal of Haehwa Medicine
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• v.23 no.1
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• pp.105-114
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• 2014

Objectives : In this study, the antioxidant activities of the 80% ethanol and hot water extracts of Euphorbia supina Rafinesque were investigated. Methods : We measured total phenol contents, flavonoid contents, 2,2-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging assay. The production of reactive oxygen species was measured in LPS-induced RAW 264.7 cells using flow cytometry system. Results : The content of phenol in the hot water extract was $65.529{\pm}0.462mg/g$ and $126.932{\pm}1.894mg/g$ in the 80% ethanol extract, and that of flavonoid in the hot water extract was $16.063{\pm}0.471mg/g$ and $29.159{\pm}1.963mg/g$ in the ethanol extract. The 80% ethanol extract also showed higher DPPH and ABTS radical scavenging activities ($90.8{\pm}1.0%$ and $92.5{\pm}0.7%$) than the hot water extract ($81.5{\pm}0.5%$ and $91.5{\pm}0.2%$). The production of reactive oxygen species(ROS) was reduced dose-dependently by 80% ethanol and hot water extract at concentration of 1, 10 and $100{\mu}g/m{\ell}$ of RAW 264.7 cells. Conclusion : According to these results, the 80% ethanol extract of Euphorbia supina Rafinesque has a good anti-oxidative effects than the hot water extract. Thus, the 80% ethanol extract of Euphorbia supina Rafinesque may serve as useful natural antioxidants.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1993.05a
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• pp.33-41
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• 1993

The objectives of this experiment performed were to determine the potential using of solar radiation to destroy organic contaminants in water by photolysis and to develop the process and improve its performance. We used lab, scale of recirculation photoreactor with 30, 50, 80ppm initial concentration of TCE and Ti $O_2$ anatase, respectively. Adsorption constant, reaction constant were obtained and compared using the Langmuir-Hinshelwood kinetics equation. Ti $O_2$ anatase demonstrated the highest conversion ratio co TCE among Ti $O_2$ anatase, ZnO and F $e_2$ $O_3$ in this experiment. It was shown that in case of two component system, TCE+ phenol, as the concentration of phenol increased in the feed solution, TCE decomposition rate decreased.

• Journal of Korean Society of Water and Wastewater
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• v.14 no.1
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• pp.54-61
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• 2000

Recently, our circumstances are threatened by an accident that leakage of under ground storage tank and illegal dumping of synthetic organic compounds at chemical plants and many treatment methods, Activated carbon adsorption, Ozonization, Membrane filtration and Photocatalystic oxidation, are developed to remove such a synthetic organic compounds. And it has reported that Activated carbon adsorption have a great removal efficiency to nondegradable matters and organic compounds which have a high molecular weight. Comparing with other adsorbents, Activated carbon adsorption have a worse efficiency when ad desorption speed is low. Thus improved type of adsorbents was invented and one of those is Activated Carbon Filter. The purpose of this study was getting information about adsorption characteristic phenol which can be applied Activated Carbon Fiber and Granular Activated Carbon. In detail, With comparing removal characteristics of phenol in the presence Humic Acid using Activated Carbon Fiber(ACF) and Granular Activated. Carbon(GAC), it is to certify an effective application of Activated Carbon Fiber. At the range of this study, Batch test, Isotherm adsorption test and Factorial analysis, following conclusion were obtained from the results of this study. Batch test was carried to know time of adsorption equilibrium. In this study about time of adsorption equilibrium by ACF was faster than GAC's, for developed micropore of ACF. From the result of phenol adsorption test, High removal rate of adsorption is shown at pH 5. The result of lsotherm adsorption test, it has represented that the Freundlich's isotherm is most suitable one in others, that a ACF's adsorption capacity is more excellent than GAC's. Adsorption of phenol exiting humic acid is decreased getting raised humic acid concentration. Since ACF's micropore is developed at this time, an effect of high molecular humic acid is lower. Factorial analysis was carried to know about Main effect which was injection dosage of adsorbent in the range of this study.

• Membrane Journal
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• v.8 no.4
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• pp.228-234
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• 1998

Among various water contaminents, organic compounds like phenol are difficult to be removed or destroyed by conventional methods under the unusual discharge conditions. The separation of phenol from aqueous solution has been carried out by several methods recently: absorption by an activated carbon, solvent extraction and liquid membrane technology. The liquid membrane based on water-oil emulsification has been tested as an alternative technology of the conventional technology. In this work, tri-n-butyl phosphate(TBP) and liquid polymers were examined as a liquid membrane in the supported liquid membrane(SLM). The feed concentration of phenol was varied and various types of liquid membranes were used to examine their effects on separation of phenol. It was found that TBP, polypropylene glycol 4000(PPG 4000) and polybutytene glycol 500(PBG 500) were proper carriers because mass transfer rates through them were much higher than or similar to that through methyl isobutyl ketone(MIBK) which was used as a conventional solvent in a solvent extraction process.