• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2003.10a
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• pp.83-88
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• 2003

• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.181-185
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• 2005

The flash point is one of the most important combustible properties used to determine the potential for fire and explosion hazards of industrial material. An accurate knowledge of the flash point is important in developing appropriate preventive and control measures in industrial fire protection. The flash points for the n-butanol+n-propionic acid and n-propanol+n-propionic acid systems were measured by using Tag open-cup apparatus(ASTM D 1310-86). The experimental data were compared with the values calculated by the laws of Raoult and van Laar equation. The calculated values based on the van Laar equation were found to be better than those based on the Raoult's law.

• Korean Chemical Engineering Research
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• v.59 no.4
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• pp.644-651
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• 2021

Alkyl amines are widely used in various industries. Nowadays these are also used in CO₂ capture technology because amines react with CO₂ and remove it from the flue gas. To make the amines more compatible towards this technology, physico chemical properties may be altered by mixing with other solvents. In the present report, we measured the refractive properties of pure diisopropylamine (DIPA) (1) + isomeric butanol (2) at 298.15 K to 308.15 K. The 𝚫n values were positive for DIPA + n-butanol or sec-butanol or isobutanol or tert-butanol mixtures. The measured data was correlated with Redlich-Kister equation. The excess molar volume data were predicted from refractive index data using Nakata and Sakurai model. The experimental data were also predicted by various correlations, and the prediction capability of these correlations was reported through standard deviation. Further, the deviation in refractive index (𝚫n) data was interpreted by the consideration of specific molecular interactions between DIPA and isomeric butanol.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.10
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• pp.1338-1345
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• 2012

This study investigated the antioxidant activities, whitening effects, and antimicrobial activities of fractions from Pleurospermum kamtschaticumin extract. Total polyphenolic contents of fractions from Pleurospermum kamtschaticumin extract were 116.44~382.73 mg/g GAE (gallic acid equivalent), with the highest value in the ethyl acetate fraction. Fractions of Pleurospermum kamtschaticumin showed the highest DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity ($IC_{50}$=0.04 mg/mL) and ABTS radical scavenging activity (98.86% at 0.5 mg/mL), which was similar to ascorbic acid. Further, reducing power and FRAP activity were significantly high in the ethyl acetate and n-butanol fractions. The ethyl acetate and n-butanol fractions showed significantly high SOD-like activities (1 mg/mL, 86.93%, and 78.23%, respectively) compared to other fractions. Tyrosinase inhibition activities of the n-butanol fraction and 80% ethanol extract were 43.52% and 41.64%, respectively. Antimicrobial activity against Escherichia coli was only observed in the chloroform fraction (16.7 mm in 0.5 mg/disc). These results suggest that fractions from Pleurospermum kamtschaticumin extract show comparatively high antioxidant activity and thus could be used as a food additive or cosmeceutical ingredient.

• Membrane Journal
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• v.10 no.1
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• pp.30-38
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• 2000

Prediction method of permeation flux and sorption characteristics in pervaporation through a polydimethylsiloxane(PDMS) memrane was suggested. The amount of sorption and permeation flux of chloroform, toluene, methanol and n-butanol were calculated with this method and compared with this method and compared with experimetal data. The calculated values of permeation flux and the amount of sorption of good solvents, that is, toluene and chloroform were well agreed with the experimental data. The lower the density of PDMS membrane is, the more permeation flux and sorption quantity were increased. However, the experimental data of poor solvents, that is, methanol and n-butanol were no so well agreed with the calculated values. It is shown that the prediction method suggested in this study may be used without experimetnal for the prediction of permeation flux and sorption quantity of the good solvent on PDMS membrane.

• KSBB Journal
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• v.30 no.6
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• pp.302-306
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• 2015

In this work, the antioxidant activity and total phenolic compound content of 6 fractions of Smallanthus sonchifolius, Agrimonia pilosa, and Lithospermum erythrorhizon extract were investigated. The highest total phenolic compound contents of each plant extracts were obtained from n-butanol ($13.75{\pm}0.21%$) and methylene chloride ($12.89{\pm}1.10%$) fractions (S. sonchifolius), ethyl acetate ($19.69{\pm}1.02%$) and water ($18.72{\pm}0.76%$) fractions (A. pilosa), and n-butanol ($36.26{\pm}1.26%$) and ethyl acetate ($17.66{\pm}0.94%$) fractions (L. erythrorhizon), respectively. As a result of DPPH radical scavenging activity in 10 mg/mL condition, the highest activity were obtained from n-butanol fraction of S. sonchifolius (81.06%), ethyl acetate fraction of A. pilosa (86.32%), and n-butanol fraction of L. erythrorhizon (82.6%), respectively. Also, the highest reducing power was obtained same fractions as well as DPPH adical scavenging activity. Overall, antioxidant activity has relatively closely connected with contents of total phenolic compounds in S. sonchifolius and L. erythrorhizon extracts.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.631-638
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• 2015

In Korea, yam with thermal treatment is widely used to produce tea and beverage, which appeals to all age groups. To better understand the antioxidative activity of thermal treatment yam (Dioscorea batatas $D_{ECNE.}$), n-butanol and ethyl acetate extracts were evaluated with different antioxidant testing system. Their antioxidant activities, including ABTS [2,2' -azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, and ferric reducing antioxidant power as well as total phenol contents were assessed in vitro. Results showed ethyl acetate extract ($51.63{\pm}2.51mg\;CAE/g$) possessed similar total phenol content compared with n-butanol extract ($53.93{\pm}1.00mg\;CAE/g$). Ethyl acetate extract also exhibited similarly stronger antioxidant activity compared with n-butanol extract apart from ABTS radical scavenging activity assay.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.599-606
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• 2015

This study aimed at evaluating the antioxidant activity of raw yam (Dioscorea batatas $D_{ECNE.}$) extracted by n-butanol and ethyl acetate. The antioxidant activities, including ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, reducing power, and ferric reducing antioxidant power as well as total phenol contents were studied in vitro. Results showed ethyl acetate extract ($111.88{\pm}0.66mg\;CAE/g$) possessed higher total phenol content than n-butanol extract ($78.68{\pm}0.58mg\;CAE/g$). Ethyl acetate extract exhibited stronger antioxidant activity compared with n-butanol extract apart from reducing power assay.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1640-1648
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• 2009

This study was carried out to investigate the antioxidant activity of bamboo (Sasa borealis) leaf extract by measuring electron donating ability, superoxide dismutase (SOD)-like activity, reducing power, and lipid peroxidation inhibitory activity. Two crude extracts by water or 70% EtOH and five fractions of n-hexane, chloroform, ethyl acetate, n-butanol, and aqueous from the crude extract of 70% EtOH were prepared for this study. The crude extracts of water and 70% EtOH yielded 8.5% and 11.4%, respectively and the yields of n-hexane, chloroform, ethyl acetate, n-butanol, and aqueous fractions were 5.1% to 0.6%. Total polyphenol contents of the water and the 70% EtOH crude extracts were not significantly different; however, their total flavonoid contents were significantly greater in the 70% EtOH than in the water crude extract. Total polyphenol contents were the highest in chloroform fraction followed by ethyl acetate and n-butanol fractions and total flavonoid contents were the highest in ethyl acetate fraction followed by chloroform and n-hexane fractions. The two crude extracts as well as the five fractions showed election donating ability, SOD-like ability, reducing power, and lipid peroxidation inhibitory activity. Most of the antioxidant activities of each crude extract or fractions increased proportionally with the concentration. These results indicate that bamboo (Sasa borealis) leaf extracts show antioxidant activities due to its substantial content of polyphenol including flavonoid. Thus, it could be concluded that crude extracts by water or 70% EtOH and the fractions from the 70% EtOH extract, especially chloroform, ethyl acetate and n-butanol, would be useful as natural antioxidant substances.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.708-715
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• 2016

This study examined the effects of an extract of Dendropanax morbifera on blood pressure, Angiotensin II, Angiotensin Converting Enzyme, Aldosterone, and lipid levels of spontaneously hypertensive rats. The groups were as follows: Control group, Hypertension control group, Water extract treated group, Ethanol extract treated group, n- hexane fraction treated group, Ethyl acetate fraction treated group, n- butanol fraction treated group, and Water fraction treated group. The blood pressure, and Angiotensin II, and Angiotensin Converting Enzyme, and Aldosterone levels were lower in the Ethyl acetate fraction treated group than in the hypertension control group. The change in blood pressure was lower in the Water extract treated group, Ethyl acetate fraction treated group, Ethanol extract treated group, n- hexane fraction treated group, and n- butanol fraction treated group than the hypertension control group. The concentration of Angiotensin II was lower in the Ethyl acetate fraction treated group, Ethanol extract treated group, n- hexane fraction treated group, and n- butanol fraction treated group than the hypertension control group(p<0.05). The level of Angiotensin Converting Enzyme was lower in the Ethyl acetate fraction treated group, Ethanol extract treated group, n- hexane fraction treated group, and n- butanol fraction treated group than the hypertension control group. The concentration of Aldosterone was lower in the Ethyl acetate fraction treated group, and n- butanol fraction treated group than the hypertension control group(p<0.05). In addition, the concentration lower in the Water extract treated group, Ethanol extract treated group, n- hexane fraction treated group than the hypertension control group. Overall, the effect of the Dendropanax morbifera extracts might be useful as anti-hypertensive, and functional food agents.