• 지질공학
• /
• 제14권4호
• /
• pp.401-416
• /
• 2004

이 연구에서는 물과 산성용액을 이용한 동결${\cdot}$융해실험을 통하여 강원도 횡성군에서 채취된 셰일의 물리적 특성변화를 측정하였다. 실험에 적용된 동결${\cdot}$융해 온도 범위는 $-20{\pm}2^{\circ}C\~15{\pm}2^{\circ}C$ 이고 시료는 12시간 동안 동결한 후 물속에서 8시간 동안 융해시켰다. 이 후 시료를 진공 챔버에서 4시간동안 수침하여 완전히 포화시켰으며, 이러한 일련의 과정을 1 cycle로 설정하였다. 본 연구에서는 매 5 cycle마다 시료의 흡수율, 탄성파 속도, 쇼어 경도, 슬래이크 내구성시험, 일축압축시험 등을 실시하였다. 동결${\cdot}$융해 실험의 반복횟수가 증가될수록 시료의 물성은 변화하였다. 일축압축강도는 물을 이용한 실험에서는 매cycle마다 0.40MPa정도 감소하였고 산성용액을 이용한 실험에서는 0.48Mra정도 감소하였으며, 탄성계수 역시 물에서 0.21Gpa, 산성용액에서 0.30GPa 감소하였다. 흡수율의 경우는 물에서 $0.29\%$, 산성용액에서 $0.37\%$ 증가되었다. 이러한 결과는 산성용액에서의 풍화속도가 물에서의 풍화속도보다 빠름을 지시한다. 그러나 탄성파속도, 쇼어경도와 슬레이크 내구성 시험에서는 물과 산성용액에 따른 차이가 거의 나타나지 않았다. 동결${\cdot}$융해 실험 결과와 연구지 역의 동절기 기간의 기온분포를 고려해 볼 때 실제 1년이 동결-응해 실험 약 $6\~12\;cycle$에 해당될 것으로 추정된다.

• Corrosion Science and Technology
• /
• 제4권6호
• /
• pp.242-249
• /
• 2005

A lot of parts in FGD (Flue Gas Desulfurization) systems of fossil-fuel power plants show the environments in which are highly changeable and extremely acidic corrosive medium according to time and locations, e.g. in duct works, coolers and re-heaters etc. These conditions are formed when system materials are immersed in fluid that flows on them or when exhausted gas is condensed into thin layered acidic medium to contact materials of the system walls and roofs. These environments make troublesome corrosion and air pollution problems that are occurred from the leakage of the condensed solution. To cathodically protect the metallic structures in extremely acidic fluid, the properties of the protective coatings on the metal surface were very important, and epoxy Novolac coating was applied in this work. On the base of acid immersion tests, hot sulfuric acid decreased the hardness of the coatings and reduced greatly the content of $Na_2O$, $Al_2O_3$, and $SiO_2$ among the main components of the coating. A special kind of CP(Cathodic Protection) system has been developed and tested in a real scale of the FGD facility. Applied coating for this CP system was peeled off and cracked in some parts of the facility. However, the exposed metal surface to extremely acidic fluid by the failure of the coatings was successfully protected by the new CP system.

• 한국식품영양학회지
• /
• 제8권2호
• /
• pp.110-115
• /
• 1995

This study was devised to observe the inhibitory effects of ethanol treatment precipitate (crude acidic polysaccharide) from Korean red ginseng on a lipolytic action of Toxohormone-L which has been known as lipolytic and anorexigenic factors. Toxohormone-L was obtained by partial purification of the ascites fluid from mice which had been inoculated with sarcoma-180. The yields of crude acidic polysaccharide from Korean red ginseng was 63.5%. In vitro, at the concentration of 500rg /ml, the inhibition rate of lipolysis by the crude acidic polysaccharide of Korean red ginseng was 38.8% and the total inhibitory activity per gram of ginseng material was 4,928 nit. In vivo, the red ginseng polysaccharide(40mg/ml in saline soon.) 16ul/g of body weight was injected to the sarcoma-180 bearing mice once In 3 days until death. The effects against the extension of life span was little but body weight gain of sarcoma-180 bearing mice decreased significantly by administration of Korean red ginseng polysaccharide compared to those of the control group.

• Journal of Ginseng Research
• /
• 제14권1호
• /
• pp.67-73
• /
• 1990

Toxohormone-L is a lipolytlc factor, found in ascites fluid of sarcoma 180-bearing mice and of patients with hepatoma. A substance that inhibited the lipolytic action of Toxohormone-L was isolated from Korean red ginseng powder. This substance had a pectin-like a-1,4-polygalacturonan backbone with some acetoxyl groups, and so was an acidic polysaccharide. Acidic polysaccharide was found to inhibit significantly toxohormone-L-induced lipolysis at its concentration of 10$\mu\textrm{g}$/ml.

• 한국식품영양학회지
• /
• 제3권1호
• /
• pp.9-12
• /
• 1990

Toxohormone-L is a lipolytic factor, found in ascites fluid of sarcoma 180-bearing mice and of patients with hepatoma. A substance that inhibited the lipolytic action of toxohormone-L was isolated from white ginseng powder. This substance was an acidic polysaccharides It inhibited toxohormone-L-induced lipolysis in a dose dependent manner at concentrations higher than 100g/ml.

• 한국식품영양학회지
• /
• 제4권2호
• /
• pp.149-154
• /
• 1991

This study was devised to observe the inhibitory effect of 7 kinds of the acidic polysaccharide fraction(PGI, PGa, PG3, PGa, PGs, PG6 and PG7) from Korean white ginseng on a lipolytic action of Toxohormone-L. Toxohormone-L is a lipolytic factor, found in ascites fluid of .sarcoma -180 bearing mice and of patients with hepatoma. A substace that inhibited the lipolytic action of Toxohormone-L was isolated from white ginseng powder. This substance was an acidic polysaccharides. In vitro test showed that the inhibitory effect of PGs fraction of the lipolysis by Toxohormone-L was highest percent among other treatments at concentration of 50, 10, 200, 500 and 1,000 Ug/ml of reaction mixture. And total inhibitory activity(units) of PGI and PG4 was highest among other treatments at the same concentration and that of 10 Ug/ml.

• 한국식품영양학회지
• /
• 제5권1호
• /
• pp.7-12
• /
• 1992

This study was devised to observe the inhibitory effect of 7 kinds PG(PG1, PG2, PG3, PG4, PG5, PG6 and PG7) and of 5 kinds PG4(PG41, PG42, PG43, PG44 and PG45) of the acidic polysaccharide fraction from Korean red ginseng on a lipolytic action of Toxohormone-L. Toxohormone-L is a lipolytic factor, found in ascites fluid. of sarcoma-180 bearing mice and of patients with hepatoma. A substance that inhibited the lipolytic action of toxohormone-L was isolated from red ginseng powder. This substance was an acidic polysaccharides In vitro test showed that the inhibitory effect of PG4 and PG43 fraction of the lipolysis by Toxohormone-L was highest percent among other treatments at concentration of 50, 100, 200, 500 and 1,000ug/ml of reaction mixture. And total inhibitory activity(units) of PG1 and PG4, and PG4 s was highest among other treatments at the same concentration.

• 한국식품영양학회지
• /
• 제3권2호
• /
• pp.133-140
• /
• 1990

Toxohormone-L is a lipolytic factor, found in ascites fluid of sarcoma 180-bearing mice and of patients with hepatoma A substance that inhibited the lipolytic action of Toxohormoue-L was isolated and purified from Korean red ginseng powder. This substance had a pectin-like $\alpha$-1,4-polygalacturonan backbone with some acetoxyl groups, and so was an acidic polysaccharide It inhibited Toxohormone-L Induced liploysis in a dose dependent manner at concentrations higher than 10 Ug/ml. Purified acidic Polysaccharide yield(PG4-3 and PG4-4 fraction) was about 0.03%. And also pectic acid that inhibited the lipolytic action of Toxohormone-L.

• Journal of Ginseng Research
• /
• 제14권1호
• /
• pp.10-13
• /
• 1990

Effect of an acidic polysaccharide fraction In Korean white and red ginseng on lipolytic action of Toxohormone-L was studied. Crude acidic polysaccharide fraction was extracted from main and lateral root of Korean white and red ginseng separately and purified several times. Inhibitory effect of crude polysaccharide fraction was determined by unit (1 unit is loft inhibition rate per Is sample). Yields of purified crude polysaccharide fraction of main and lateral root of red ginseng were 2.9 and 2.2 times higher than those of white ginseng, respectively. Inhibitory effects of main root of white and red ginseng, 11.hen final reaction concentrations of sample were 50, 100, 200, 500 $\mu$g/ml, were 37.2가 and 23.7% higher than those of lateral root of white and red ginseng. Inhibitory effect of main root of red ginseng was 2.3 times higher than that of white ginseng.

• Archives of Pharmacal Research
• /
• 제18권3호
• /
• pp.141-145
• /
• 1995

Omeprazole, a proton pump inhibitor, was given intravenously (iv), orally (po), intraperitoneally (ip), hepatoportalvenously (pv), and intrarectally (ir) to rats at a dose of 72mg/kg in order to investigate the bioavailability of the drug, The extent of bioavailabilities of omeprazole administered through pv, ip, po, and ir routes were 88.5, 79.4, 40,8, and 38.7%, respectively. Pharmacokinetic analysis in this study and literatures (Regardh et al., 1985 : Watanabe et al., 1994) implied significant dose-dependency in hepatic first-pass metabolism, clearance and distribution, and acidic degradation in gastric fluid. The high bioavailability from the pv administration (88.5%) means that only 11.5% of dose was extracted by the first-pass metabolism through the liver at this dose (72 mg/kg). The low bioavailability from the oral administration (40.8%) in spite of minor hepatic first-pass extraction indicates low transport of the drug from GI lumen to portal vein. From the literature (Pilbrant and Cederberg, 1985), acidic degradation in gastric fluid was considered to be the major cause of the low transport. Thus, enteric coating of oral preparations would enhance the oral bioavailability substantially. The bioavailability of the drug from the rectal route, in which acidic degradation and hepatic first-pass metabolism may not occur, was low (38.7%) but comparable to that from the oral route (40.8 %) indicating poor transport across the rectal membrane. In this case, addition of an appropriate absorption enhancer would improve the bioavailability. Rectal route seems to be an possible alternative to the conventional oral route for omeprazole administration.