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        검색결과 5

        1.
        2010.12 KCI 등재 서비스 종료(열람 제한)
        The application of metal caps has been continuously increased as real life are extended. Metal caps is usually made of aluminum and polyethylene(PE) as packing. Since metal caps contain 75% aluminum on a weight basis, metal caps may be a valuable source when these were properly recovered. The recovery methods of metal caps have mechanical peeling and incineration. However these are either hard to apply in some case or environmentally unacceptable. So in this investigation, recovery method of aluminum from metal caps was investigated using pyrolysis. The result shows that pyrolysis temperature and pyrolysis time was 450℃ and 120min. respectively. Also 100% of aluminum was recovered from metal caps. Heat content of recovered oil was high enough to use as a fuel representing 7,425.0, 7,793.1, 7,583.2, 7,726.2(cal/g). Heavy metal contens in the oil were under regulatory limit indicating.
        2.
        2000.10 KCI 등재 서비스 종료(열람 제한)
        On the basis of theory of Bratsch's electronegativity equalization, the electronegativity equalization, the group electronegativities and the group partial charges for cationic and amphoteric surfactants could be calculated using Pauling's electronegativity parameters. From calculated output, we have investigated relationships between CMC(critical micelle concentration) and partial charge and group electronegativity of hydrophilic and hydrophobic groups, structural stability of micelle for cationic and amphoteric surfactants. As a result, CMC depends upon partial charge and electronegativity of hydrophilic and hydrophobic groups for surfactants. In case of cationic surfactant, as the increment of carbon number in hydrophilic group, partial charge of hydrophilic group is increased, but CMC and electronegativity of hydrophilic group is decreased. With increasing the carbon number of hydrophilic group for cationic surfactant, its partial charge is increased, but CMC and its electronegativity are decreased. With increasing the carbon number of hydrophobic group for cationic and amphoteric surfactant, its partial charge is increased, but CMC and its electronegativity are decreased
        3.
        1999.02 KCI 등재 서비스 종료(열람 제한)
        Silicone oil has organic and inorganic properties, and its skeleton is polysiloxane bonding that silicon is bonded hydrogen or organic group. Silicone compounds are very smooth and lubricant properties by low surface tension, low temperature dependence, and nonadhesive properties. Because of these properties, silicone compounds are used as many parts of chemicals, softener, smooth and libricant agents, water-repellent agent, and defoaming agent, etc. Emulsion was prepared with the inversion emulsification method which adopted the agent-in-oil method dissolving the polyoxyethylene(7) tridecyl ether(HLB 12.2) into methoxy terminated poly(dimethyl-co-methyl amino) siloxane and hydroxy terminated poly(dimethylco-methyl amino) siloxane in water. At this time, processed emulsion was almost microemulsion. When ratio of emulsifier increases, emulsion is stable bacuause microemulsion is solubilized by emulsion drop size and zeta-potential are decreased. But, when amount of electrolyte is increase, emulsion became unstable because emulsion drop size is increased.
        5.
        1995.08 KCI 등재 서비스 종료(열람 제한)
        In order to study on the long-term change of water quality, water analysis was conducted at 16 sites surrounding the Kumho river system for 11 times from September 1990 to August 1993. Analytical items for the study of water quality are as follows; water temperature, pH, COD, BOD, DO, SS, electrical conductivity, NH_3-N, NO_2^- -N, NO_3^- -N, PO_4^3- -P, total-P, hardness, oil and grease, ABS, phenol, zinc, chromium, cadmium, manganese, iron, lead and color. The long-term change of water quality in the Kumho river for the period studied was found that the values of water temperature, electrical conductivity, phenol, NO_2^- -N and NH_3-N were increasing and those of COD, BOD, SS, oil and grease, ABS, NO_3 -N, PO_4^3- -P, copper, zinc, chromium, cadmium, manganese and lead were decreasing, while those of pH, hardness, iron and manganese were steady.