• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1785-1787
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• 2000

This paper present the result of the investigation, the electric properties of insulators due to non-soluble contamination. In general, the humidity and the amount of soluble salts such as NaCl, $MgCl_2$ are the most dominant factor. Though the non-soluble do not distribute on conductivity of contaminant layer, that has the hygroscopic property. For this study, we make a mini-fog chamber with transparent acryl and the kaoline was used for non-soluble contaminant. The kaoline was applied with sprayer to get the specific ESDD and NSDD value, then the specimen was dried and installed horizontally. And to measure the leakage current a DAS system was developed with LabView. With the result, we could know the influence of non-soluble content and the relationship between NSDD and ESDD.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.691-695
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• 2000

This paper present the result of the investigation, the electric properties of insulators due to non-soluble contamination. In general, the humidity and the amount of soluble salts such as NaCl, MgCl$_2$are the most dominant factor. Though the non-soluble do not distribute on conductivity of contaminant layer, that has the hygroscopic property. For this study, we make a mini-fog chamber with transparent acryl and the kaoline was used for non-soluble contaminant. The kaoline was applied with sprayer to get the specific ESDD and NSDD value, then the specimen was dried and installed horizontally. And to measure the leakage current a DAS system was developed with LabView. With the result, we could know the influence of non-soluble content and the relationship between NSDD and ESDD.

• 한국잡초학회지
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• 제17권2호
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• pp.135-138
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• 1997

Sulfonylureas are highly active herbicides which can be applied at very low rate(10-50g/ha) to control broadleaf weeds. The nature of this category of compound is, however, very unstable toward hydrolysis. Therefore, the preparation of these compounds as liquid formulation was not possible. Most of the current formulations of sulfonylurea are in dry forms such as water dispersible granule or wettable powder. Even in these dry forms, the active ingredients also encounter significant chemical decomposition. This study involves the preparation of the sulfonylurea salts by reacting the parent compound with base such as sodium hydroxide. The salt becomes stable toward hydrolysis and it turns soluble when diluted with water. This discovery makes the preparation for liquid formulation or soluble granule of sulfonylurea possible. The stoichiometry of base added to the neutral sulfonylurea is controlled quite precisely. The base has to be added enough to quench the acidic impurities in the technical material and to convert the active ingredient into salt. However, the base should not be overused to cause further saponification of the sulfonylurea salts. The chemical nature of these compounds is presented and the chemical reaction is described. New soluble liquid formulation and solid granule formulation of sulfonylurea are suggested.

• 한국토양비료학회지
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• 제49권3호
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• pp.265-270
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• 2016

Accumulated Phosphate can be released by ligand exchange reaction of organic acids. The objective of this study was to evaluate effects of the organic acids on the availability of phosphate and the growth of crop in phosphate and salts accumulated soil. Soil samples were collected from farmer's plastic film house. Available phosphate and electrical conductivity of soil were $3,005mg\;kg^{-1}$ and $16.63mg\;kg^{-1}$ which were 6 and 8 times higher than the optimum range of soil for crop growth, respectively. Corns were cultivated in pots for 2 months. Treatments were no treatment (control), phosphate fertilizer (P), citric acid (CA) 1, 5, 10 mM, and oxalic acid (OA) 1, 5, 10 mM. Water soluble phosphorus, available phosphate, corn growth and uptake were determined after cultivation. Results showed that organic acids increased water soluble phosphorus and available phosphate. For the level of 10 mM, the order of effectiveness of organic acids for water soluble P was citric acid (44%) > oxalic acid (32%). Height and dry weight of corns were increased significantly by the treatment of citric acid 1 and 5 mM. Also, corn absorbed more phosphorus, nitrogen, potassium, calcium and magnesium in the treatment of citric acid 1 mM than these of other treatments. Even though phosphate availability of soil was enhanced by addition of citric acid 10 mM, the growth of corns decreased because high concentration of citric acid caused salt damage by increasement of electrical conductivity. Thus, the citric acid of 1 mM has the potential to improve the availability of phosphate and the healthy growth of corns.

• Asian-Australasian Journal of Animal Sciences
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• 제18권2호
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• pp.282-295
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• 2005

The processing of dietary lipids can be distinguished in several sequential steps, including their emulsification, hydrolysis and micellization, before they are absorbed by the enterocytes. Emulsification of lipids starts in the stomach and is mediated by physical forces and favoured by the partial lipolysis of the dietary lipids due to the activity of gastric lipase. The process of lipid digestion continues in the duodenum where pancreatic triacylglycerol lipase (PTL) releases 50 to 70% of dietary fatty acids. Bile salts at low concentrations stimulate PTL activity, but higher concentrations inhibit PTL activity. Pancreatic triacylglycerol lipase activity is regulated by colipase, that interacts with bile salts and PTL and can release bile salt mediated PTL inhibition. Without colipase, PTL is unable to hydrolyse fatty acids from dietary triacylglycerols, resulting in fat malabsorption with severe consequences on bioavailability of dietary lipids and fat-soluble vitamins. Furthermore, carboxyl ester lipase, a pancreatic enzyme that is bile salt-stimulated and displays wide substrate reactivities, is involved in lipid digestion. The products of lipolysis are removed from the water-oil interface by incorporation into mixed micelles that are formed spontaneously by the interaction of bile salts. Monoacylglycerols and phospholipids enhance the ability of bile salts to form mixed micelles. Formation of mixed micelles is necessary to move the non-polar lipids across the unstirred water layer adjacent to the mucosal cells, thereby facilitating absorption.

• Journal of Dairy Science and Biotechnology
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• 제22권1호
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• pp.13-25
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• 2004

담즙산은 cholesterol의 대사산물로 체내에서 cholesterol을 제거하는 주경로로서, 체내 cholesterol 대사를 조절하는 중요한 수단이다. 최근에 복합담즙산 분해활력이 높은 L. acidophilus에 의한 혈중 cholesterol 저하효과에 관한 많은 연구들이 보고되고 있으며, 이것은 복합담즙산의 분해로 생성되는 유리 담즙산의 분 배출 증가와 장내 cholesterol 흡수에 필요한 복합 micelle 형성의 방해에 의한 것으로 알려져 있다. 즉, 유리 담즙산은 장내에서 복합담즙산보다 용해성이 낮아서 흡수되지 않고 분으로 배출되기 쉬워, 간에서는 분으로 배출된 양만큼의 부족한 복합담즙산을 보충하기 위해 cholesterol을 이용하여 새로운 복합담즙산을 생성하기 때문에 결국은 체내의 혈중 cholesterol 수준을 감소시키는 것으로 생각된다. 또한 담즙으로 분비되는 복합담즙산은 소장내에서 cholesterol의 용해 흡수에 도움을 주지만 유리 담즙산은 cholesterol 용해성이 낮기 때문에, 장내 cholesterol 흡수에 영향을 미치는 것으로 생각된다.

• Journal of Nutrition and Health
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• 제15권1호
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• pp.9-14
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• 1982

The present paper describes a colorimetric method of determining the free and total unsaturated fatty acids in animal tissues. The procedure is based in three steps on the following principles : First step is that the tissue homogenates are extracted in chilled acetone in order to eliminate the interfering substance, such as phospholipids, sulfatides and proteins. At next step, after centrifugation acetone layer is decanted and evaporated to dryness. Then the extract is shaken with heptane to solve in the solvent. That the characteristic nature of copper salts of unsaturated fatty acids are freely soluble in heptane and those of saturated acids are not is the bases of separating one from another. Thus unsaturated fatty acids can be isolated in heptane as their salts from saturated acids and other lipid mixture by shaking with copper reagent. Finally the yellowish brown color developed by adding color reagent (0.2% sodium diethyldithiocarbamate in n-butanol solution) which reacts with the copper salts of the acids and produces the color is measured colorimetrically.

• 한국응용과학기술학회지
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• 제20권4호
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• pp.372-376
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• 2003

Water-soluble cutting fluids are used for processing of aluminium materials. This short article describes properties of new additives of water-soluble cutting fluids for aluminium materials. Various Diels-Alder adducts of unsaturated fatty acids with acrylic acid of maleic anhydride were prepared by thermal reactions. Triethanolamine salts of Diels-Alder adducts of dehydrated castor oil fatty acids with acrylic acid or maleic anhydride showed excellent anti-corrosion property of aluminium materals. These thermal adducts showed anti-rust property for cast-iron chips, too.

• 한국환경과학회지
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• 제24권6호
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• pp.785-792
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• 2015

This study investigates weekday/weekend characteristics of $PM_{10}$ concentration and chemical composition of water-soluble ions in Busan in the spring of 2013. Contribution rate of water-soluble ions to PM10 concentration in weekday/weekend were 41.5% and 38.5%, respectively. Contribution rate of SO_4{^{2-}}$ to total ion mass in weekday/weekend were 30.4% and 33.8%, respectively. Contribution rate of total inorganic water-soluble ions in PM10 in weekday/weekend were 42.2% and 39.1% (mean 41.4%), respectively. $[NO_3{^-}/SO_4{^{2-}}]$ ratio in weekday/weekend were 1.01 and 0.97(mean 0.99), respectively, which indicated that weekday ratio was higher. Contribution rate of sea salts and $Cl^-/Na^+$ ratio in PM10 in weekday/weekend were 8.1% and 7.6%, 0.37% and 0.41%, respectively. This research will help understand chemical composition of water-soluble ions during the weekday/weekend and will be able to measure the contribution level of artificial anthropogenic source on urban air.

• 멤브레인
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• 제12권3호
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• pp.151-157
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• 2002

본 연구는 하수를 공업용수로 재이용하기 위한 분리막 시스템 적용에 관한 연구이다. 정밀여과와 역삼투시스템으로 구성된 bench scale 실험장치를 이용하여 하수처리장 현장에서 실험을 수행한 결과, 정밀여과 시스템은 이온성분은 제거할 수 없었으나 SS를 70% 이상 처리할 수 있어 처리수는 직접냉각수로 재이용이 가능하였다. 그리고 역삼투 시스템은 SS는 물론 이온성분도 95% 이상 제거할 수 있어 처리수는 간접냉각수 및 제품세척수로 사용이 가능하였다. $100 m^3$/일 용량의 pilot Plant를 제작하기 위해서는 정밀여과 모듈은 20개, 역삼투 모듈은 12개가 필요하였다.