• 한국지하수토양환경학회지:지하수토양환경
• /
• 제9권3호
• /
• pp.20-26
• /
• 2004

2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD)로 오염된 토양의 현장 광분해 정화 과정에서 가장 중요한 이동 메커니즘인 지표에서의 증발 및 광분해에 의한 유기 용매의 이류 상방향 이동에 대한 수식화와 모델 개발을 수행하였다. 각 유체 분포에 대한 다상 유동 효과, 구동력으로서의 중력, k-S-p 관계의 정확한 묘사를 위한 van Genutchen 방정식을 포함한 유한요소법 기반의 수치 모델을 제안하였다. 실험실 규모의 비포화 토양 컬럼 내 용매 이동에 중요한 영향을 미치는 인자들을 조사하기 위하여 수행한 계산의 결과들을 제시하였다. 중력은 고투수성 토양의 유체 분포와 증발에 상당한 영향을 미쳤다. 토양의 종류 또한 증발 과정 중 유체 포화도 분포에 큰 영향을 미친다. 용매의 이류 이동량은 증발량이 증가할수록 초기 물 포화도가 감소할수록 증가하였다. 본 연구에서 수행한 시뮬레이션은 개발된 모델이 토양 환경 내에서 유기 용매의 이류 이동에 영향을 미치는 다양한 인자들의 영향을 분석하는데 유용함을 보여준다.

• 한국식품영양학회지
• /
• 제20권2호
• /
• pp.134-142
• /
• 2007

This study was performed to determine the antioxidative and cytotoxic effects of Elaeagnus multiflora by examining its scavenging effects on the 1,1-diphenyl-2-picryl-hydrazyl(DPPH) radical, the inhibition of lipid peroxidation, and its inhibitory effects on cancer cell proliferation in HeLa cells, MCF-7 cells, and SNU-638 cells by MTT assay. Here, dried samples were extracted in ehtanol at room temperature and fractionated into five different solvent types: hexane, dichloromethane, ethylacetate, butanol, and aqueous partition layers. The hexane(62.92${\pm}$2.45%) and dichloromethane(65.25${\pm}$4.74%) fractions of Elaeagnus multiflora's flesh, and the aqueous(94.65${\pm}$0.02%) and ethylacetate(93.83${\pm}$0.02%) fractions of Elaeagnus multiflora's seeds, inhibited DPPH radical production. The DPPH radical scavenging effects of the flesh and seed were different according to solvent fractions. The inhibition of lipid peroxidation by the flesh and seed extracts were 76.11${\pm}$3.66 and 69.57${\pm}$2.27, respectively, for hexane and 67.57${\pm}$2.43 and 62.09${\pm}$0.90, respectively, for the dichloromethane fraction. Among the various partition layers of Elaeagnus multiflora's flesh, hexane and dichloromethane showed the strong cytotoxicities on all the cancer cell lines used in the study. Also all the fractions of Elaeagnus multiflora's seed exhibited significant effects on the inhibition of cancer cell growth(hexane > dichloromethane > ethylacetate > butanol > aqueous partition layers). These results indicate that the haxane and dichloromethane partition layers of Elaeagnus multiflora's flesh and seed extracts have possible antioxidative and anticancer capacities. Although further studies are needed, the present work suggests that Elaeagnus multiflora may be an antioxidative and chemopreventive agent.

• 센서학회지
• /
• 제15권5호
• /
• pp.371-377
• /
• 2006

Nano porous, transparent silica aerogels monoliths were prepared under ambient drying (1 atm, $270^{\circ}C$) condition by the combination of sol-gel process and surface modification with subsequent heat treatment. Three kinds of solvent, n-hexane, n-heptane and xylene, were selected in the point view of low surface tension and vapor pressure in order to restrain a formation of cracks during drying. Crack-free silica aerogels with over 93 % of porosity and below $0.14g/cm^3$ of density were obtained by solvent exchange and surface modification under atmosphere condition. Optimum solvent was confirmed n-heptane among these solvents through estimation of FT-IR, TGA, BET and SEM. Modified silica aerogel exhibited a higher porosity and pore size compare to unmodified aerogels. Hydrophobicity was also controled by C-H and H-OH bonding state in the gel structure and heat treatment over $400^{\circ}C$ effects to the hydrophobicity due to oxidation of C-H radicals.

• 한국전기전자재료학회논문지
• /
• 제25권6호
• /
• pp.426-430
• /
• 2012

The properties of green sheet were investigated in order to understanding an effects of organic solvent mixture ratio for solid oxide fuel cells fabrication. The purpose of this work is to optimize the slurry condition using the design of experiment to improve green sheet properties. The elongation increased with increasing amount of binder and solvent. With increasing amount of solvent, the air permeability increased but the tensile strength decreased. The best properties of the green sheet appeared amount of the binder 17 wt%, solvent 35 wt% and powder 48 wt%. The optimum condition of green and sintered density for solid oxide fuel cells fabrication was obtained in the sample pressured at 800 $kgf/cm^2$.

• 생약학회지
• /
• 제30권3호
• /
• pp.275-279
• /
• 1999

The solvent extracts from Aloe arborescens and Aloe vera were randomly screened for inhibitory effects on the growth of tumor cell lines. In case of Aloe vera extracts, butyl alcohol extract and ethyl alcohol extract showed antitumor activity at $100\;{\mu}g/ml$ on lung cell lines(A427, Sk-mes-1, Calu-3 and 3LL). In Aloe arborescens extracts, butyl alcohol extract and ethyl alcohol extract exerted high activity at $100\;{\mu}g/ml$ on breast cell line(Hs-578T) and lung cell line(Sk-mes-1), respectively. The solvent extracts from Aloe vera exerted antitumor activity broadly on various tumor cell lines. In contract, the solvent extracts from Aloe arborescens exerted specific antitumoricity on a few tumor cell lines.

• 한국염색가공학회지
• /
• 제26권3호
• /
• pp.209-217
• /
• 2014

Detergency and soil redeposition of wool fabric in drycleaning solvents, i.e. petroleum solvent, perchloroethylene (PCE), decamethylcyclopentasiloxane($D_5$), with commercial detergents were studied. The detergency of wool soiled cloth in drycleaning solvents without detergents were the order of PCE > petroleum solvent > $D_5$. When commercial detergents were added to the system, the detergency were greatly improved. When 1.0% water was added to solvents/commercial detergents system, the detergency of petroleum solvent and PCE improved whereas that of $D_5$ decreased. The soil redeposition prevention effects of solvents were the same order of detergency, i.e. PCE > petroleum solvent > $D_5$. When commercial detergents were added to the system, the soil redeposition changed depending on solvents and detergents. The soil redeposition in $D_5$ became higher with a commercial detergent, therefore it is important to develop appropriate detergents for $D_5$. Three silicone surfactants were tested for detergency and soil redeposition in $D_5$ to find candidate surfactants for drycleaning detergent formulations. Silicone surfactant PEG/PPG-19/19 Dimethicone was found to be the best surfactant for $D_5$ drycleaning detergents.

• 한국염색가공학회지
• /
• 제24권2호
• /
• pp.138-144
• /
• 2012

Detergency and soil redeposition of wool fabric in 8 nonionic surfactants (Span 20, 40, 60, 80/Tween 20, 40, 60, 80) and 4 solvents (water, petroleum, perchloroethylene(PCE), decamethylcyclopentasiloxane($D_5$)) were studied. Detergency of wool fabric in water was very low with and without surfactants due to the low wetting and difficulty in penetration of water into the fabric. Lipophilic surfactants improved the detergency of wool fabric in petroleum solvent and PCE. The detergency of wool fabric in $D_5$ was similar to that in petroleum solvent without surfactants. When water was solubilized, Span 20 addition to petroleum solvent and PCE increased the detergency of wool fabric. The detergency for $D_5$ was improved with solubilized water, however, it was lowered when the surfactants were added to the system. Therefore, it is important to formulate appropriate detergents which have good solubility and affinity to silicone for $D_5$ charge system. Hydrophilic surfactants were effective for water and lipophilic surfactants were effective for petroleum solvent and PCE in soil redeposition prevention of wool fabric. The soil redeposition prevention effects are not found in $D_5$ with both Span 20 and Tween 20. The same tendency of results in soil redeposition of wool fabric is observed when water is solubilized.

• Bulletin of the Korean Chemical Society
• /
• 제17권11호
• /
• pp.1056-1061
• /
• 1996

Solvolysis rates of 1-(4-methoxyphenyl)-l-phenyl-2,2,2-trifiuoroethyl chloride (1) and 1-(4-methoxyphenyl)-1-phenylethyl chloride (2) were measured in a variety of aqueous binary solvents, and the solvent effect was treated with the Grunwald-Winstein equation. The solvent effect on the solvolysis of 1 failed to give a single linear correlations using the ordinary Y or YCl, but exhibited the wide split pattern which could not be related to the solvent nucleophilicity. The improved correlations with YBnCl and extended dual-parameter treatment, log (k/k0)=mYCl+hI (mΔYΔ), were observed for the solvolysis of 1. These results suggest that the incipient cationic charge in the solvolysis of 1 is delocalized strongly into the aryl-rings in the transition state. While the solvent effect on the solvolysis of 2 is better correlated with Y or YCl than YBnCl but the linearity is not satisfactory. The correlation is comparably improved by the use of the extended Grunwald-Winstein equation, log (k/k0)=0.81YCl+0.26NOTs (R=0.994, SD=±0.12), indicating the cationic charge of reaction center of 2 was localized mostly in the transition state.

• 대한수의학회지
• /
• 제46권4호
• /
• pp.323-326
• /
• 2006

Suaeda (S.) asparagoides $M_{IQ}$, one of the halophyte groups, has been used as a folk remedy for digestive disturbances in Korea. However, its pharmacological activity on gastrointestinal motility has not been reported yet. In this study, the effects of this halophyte extracts with various solvent fractions (ethanol, hexane, chloroform, ethyl acetate, butanol, and water) on mice ileal spontaneous motility was examined. All solvent fractions at the concentration of $100{\mu}g/ml$ showed inhibitory actions on spontaneous motility of ileum with the potency order of water > 70% ethanol > hexane ${\gg}$ chloroform ${\geq}$ butanol ${\geq}$ ethyl acetate, respectively. In addition, the water fraction of extracts from S. asparagoides $M_{IQ}$ (WFSA) dose-dependently ($1-100{\mu}g/ml$) inhibited the amplitude of spontaneous phasic contraction and area under the contractile curve (AUC). The inhibitory effect of water fraction at the concentration of $10{\mu}g/ml$ was not affected by tetrodotoxin (TTX), $Na^+$ channel blocker ($1{\mu}M$), and $N^w$-nitro-L-arginine Methyl Ester (L-NAME), nitric oxide synthase inhibitor ($100{\mu}M$). However, cyclopiazonic acid (CPA, $10{\mu}M$), inhibitor of sarcoplasmic reticulum $Ca^{2+}$-ATPase, almost blocked the inhibitory effects of WFSA ($10{\mu}g/ml$) on the spontaneous phasic contraction of mouse ileum. But, CPA did not inhibit the lowering basal tone effects of WFSA. The result of this study showed that various extracts of S. asparagoides $M_{IQ}$ induce inhibitory effects on spontaneous contraction of mice ileal segments. More over, the polar solvent fractions were shown to be more potent than non-polar solvent fractions. The effects of S. asparagoides $M_{IQ}$ extracts are not mediated by nerve or nitric oxide. The inhibitory effects of WFSA at least partially mediated by sarcoplasmic reticulum $Ca^{2+}$-ATPase. However, further study is required to determine the exact pharmacological mechanisms of this halophyte on its gastrointestinal motility inhibitory effects.

• 생약학회지
• /
• 제32권3호통권126호
• /
• pp.175-180
• /
• 2001

Solvent extracts of 17 plants collected in Cheju Island were investigated for their biological properties related to cosmeceuticals such as tyrosinase and hyaluronidase inhibition and also radical scavenging effects. The chloroform fraction of Phytolacca esculenta root exhibited strong inhibition against tyrosinase activity. No fraction showed significant hyaluronidase inhibition. Some solvent extracts of plants such as Achyranthes japonica and Artemisia princeps showed considerable radical scavenging activities.