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        검색결과 93

        66.
        2010.06 KCI 등재 서비스 종료(열람 제한)
        Mesoporous silica was prepared from hydrothermal synthesis using gel mixture of tetraethylorthosilcate (TEOS) as silica source and cetyltrimethylammonium bromide (CTMABr) as a surfactant. In the optimum synthesis cause, molar ratio of template and silica changed. The surface and structure properties of mesoporous silica were determined by XRD, SEM, TEM and BET. Also, surface potential of mesoporous silica was measured using zeta potential. N2 adsorption isotherm characteristics, including the specific surface area (SBET), total pore volume (VT), and average pore diameter (DBJH), were determined by BET. As a result, SBET of 100 m² /g~1500 m² /g was determined from the N2 adsorption isotherm. Also, the average pore diameter was 2 nm∼4 nm. Mesoporous silica's surface potential of minus charge was determined from zeta potential.
        68.
        2009.12 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to develop an organic control of powdery mildews of cucumber by using mayonnaise in green house. The treatment of 0.1~2% mayonnaise resulted in 8.3%~99.2% control efficiencies against powdery mildew of cucumber. 0.5% mayonnaise treatment resulted control values over 97% in disease. It did not adversely affected the photosynthesis of foliages. Although one application of mayonnaise to the foliage was not practically effective enough, two or three application of mayonnaise to the foliage at the 0.5% concentration resulted in excellent control against powdery mildews. This treatment could provide protection for 10~14 days after application. Among the type of mayonnaise, general mayonnaise revealed 97.5% control value, but mayonnaise containing low oil content revealed 39.3%~97.5% control values on powdery mildews at the 0.5% concentration. Therefore, oil content in mayonnaise played a essential material to control powdery mildew. Results indicated that mayonnaise could be used as organic control of powdery mildews of cucumber. This control might be environmentfriendly as well as cost-effective.
        71.
        2007.06 KCI 등재 서비스 종료(열람 제한)
        Mesoporous silicas for heavy metals adsorption were prepared by co-condensation of surfactant as a template and Ludox HS-40 as a silica precursor. Various mesoporous silicas with the introduction of chelating ligands (mercaptopropyl and aminopropyl groups) were synthesized to remove heavy metal ions from aqueous solutions. The surface modification was conducted with a co-condensation process using the sequential or simultaneous addition of mesoporous silica and high concentration of the organosilane(3-mercaptopropyltrimethoxysilane and 3-aminopropyltriethoxysilane). These materials have been characterized by elemental analysis, XRD, SEM and TEM analysis. Adsorbents synthesized with 3-mercaptopropyltrimethoxysilane and 3-aminopropyltriethoxysilane shows a high loading capacity for Hg(II), Pb(II) , Cd(II) and anion Cr(VI). Especially the one synthesized with a mercaptopropyl function has the highest adsorption capacity for Hg(II) and Cd(II).
        72.
        2007.06 KCI 등재 서비스 종료(열람 제한)
        In this study, N doped TiO2 (TiO-N) thin film was prepared by DC magnetron sputtering method to show the photocatalytic activity in a visible range. Various gases (Ar, O2 and N2) were used and Ti target was impressed by 1.2 kW-5.8 kW power range. The hysteresis of TiO-N thin film as a function of discharge voltage wasn't observed in 1.2 and 2.9kW of applied power. Cross sections and surfaces of thin films by FE-SEM were tiny and dense particle sizes of both films with normal cylindrical structures. XRD pattern of TiO2 and TiO-N thin films was appeared by only anatase peak. Red shift in UV-Vis adsorption spectra was investigated TiO-N thin film. Photoactivity was evaluated by removal rate measurement of suncion yellow among reactive dyes. The photodegradation rate of TiO2 thin film on visible radiation was shown little efficiency but TiO-N was about 18%.
        73.
        2006.04 KCI 등재 서비스 종료(열람 제한)
        Adsorption characteristics of benzene by zeolite were investigated using irradiating microwave. Experimental apparatus was applied to a U-type fix-bed column equipped with microwave system. Zeolite, itself, seems to be inappropriated to remove benzene because of a hygroscopic property. Microwave irradiation to zeolite, however, brings about decreasing H2O adsorption and increasing benzene adsorption. This causes that the dipole material such as H2O was vibrated and heated by irradiation of microwave and desorbed from zeolite. And then, benzene starts to be absorbed by zeolite. In this study, the results showed that the selective adsorption of benzene was occurred by the microwave irradiation and the adsorption capacity of benzene was increased by increasing microwave energy. As a results, it was found that the zeolite could be used to adsorb benzene with microwave and this method make it feasible simultaneously to adsorb and desorb benzene.
        74.
        2005.12 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study was to offer the opportunity of contact with the nature to elementary school student by the creative educational space. We proposed educational space considering of the effects of environmental education, which transform plan into the system of nature image and effective space to ecological education space. The elementary school space is designed to be flexible in accommodating different time and events. It should be expected thin this design as following points: It will be improved environmental quality in elementary school, changed into the sustainable and environment-friendly green school as well. It will be energetic school as a living space for rest and ecological education. it will be improved the image of school and opened to the public. Through the elementary school space created by this plan, elementary school student will have more opportunity of contact with the nature.
        75.
        2004.06 KCI 등재 서비스 종료(열람 제한)
        The feasibility and efficiency of the hydrogen peroxide produced by an electrolysis cell reactor was investigated. From regulating voltages for the given reaction time, the concentration of the hydrogen peroxide was gradually increased with increasing voltages. Optimal voltage range was found to be 10~15 V. The concentration of hydrogen peroxide was much higher with oxygen gas than without oxygen gas in the cathodic chamber. But there was a little difference in the generating rate of hydrogen peroxide regardless of the presence of nitrogen gas. Under given conditions, the maximum value of ICE(Instantaneous Current Efficiency) was about 38%, and then current density was 74 mA/cm2. The specific energy consumption was 0.694[㎾h/kg-H2O2]. Since Esp (Specific Energy Consumption)was very little value, It did not demand high energy in this system. Using the hydrogen peroxide gained in the experiment, Fenton's reaction was conducted and the removal of nitrobenzene, 3-chlorophenol and dye wastewater was studied. This results were very similar to the Fenton's reaction by using commercial hydrogen peroxide.
        76.
        2003.10 KCI 등재 서비스 종료(열람 제한)
        The aim of this study is, firstly, to find out what kinds of inorganic species are produced in the photocatalytic oxidation of ammonium-nitrogen containing water and, secondly, to seek the influence of anion for the photocatalytic oxidation of ammonium contained compounds. The photoenergy above 3 eV(λ<415 nm) was effectively absorbed by TiO2 and TiO2/polymer was used to be oxidized NH4-N in wastewater to NO3-N. Existing the anion as Cl-, the rate of photocatalytic oxidation decreased regardless of other condition. This result showed that the chloride ions reduced the rate of oxidation by scavenging oxidizing radical species as OH- and OCl-. Some of the added ion might have blocked the active sites of the catalyst surface, thus deactivated the catalyst.
        77.
        2003.09 KCI 등재 서비스 종료(열람 제한)
        The high speed elimination process of suspended solid was investigated to treat the pulp waste water by using surface modified magnetite particle and magnetic power. The effects of the various aluminum salts such as Al(NO3)3·9H2O, AlCl3·6H2O, Al2(SO4)3·13~14 on the COD, BOD and suspended solid were systematically studied. It has been found that the 2.0 wt% of Al was most effective for the modification of Fe3O4 powder and then best for the treatment of pulp waste water. Optimum quantity of modified magnetite in this study was 12 wt%, and aging time was found to be 12 hours. Comparing with the conventional process, the required time for SS removal was drastically decreased. BOB and COD were also effectively removed when applied to the pulp wastewater.
        80.
        1999.08 KCI 등재 서비스 종료(열람 제한)
        Dye wastewater was treated by using an electrochemical oxidation process. Various combinations of electrodes such as carbon, Al and Fe were investigated. In this study, electrode material, electrolyte concentration, electrode distance, current density, and pH value were found to have significant effect on both pollutant removal efficiency and current efficiency in electrochemical oxidation process. After electrolysis for 40min with carbon/Al, it was observed that COD, T-N, NH4+ -N and color of treated wastewater were reduced from 580㎎/ℓ to 145㎎/ℓ, 67.2㎎/ℓ to 26.8㎎/ℓ, 46.8㎎/ℓ to 1.4㎎/ℓ, and 4200 Pt-Co units to 336 Pt-Co units, respectively. The optimal conditions of the electrooxidation process to treat the wastewater for this study were found to be such as : current density ; 16.67mA/㎠, electrode distance ; 2.5cm, pH value ; 5.0 and carbon/Al electrode.
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