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        44.
        2001.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Curing reaction was carried out with the acrylic resin (ACR) [n-butyl acrylate/atyrene/2-hydroxyethyl methacrylate/acetoacetoxyethyl methacrylate (AAEM)] synthesized before and a curing agent, hexamethoxymethylmelamine (HMMM). With rotational rheometer, the effect of catalysts on curing rate of acrylic resin/melamine was examined. Among the four catalysts used, p-toluene sulfonic acid showed the highest reactivity, and the optimum amount of catalyst was 0.5 phr. It was observed that in the ACR/HMMM curing reaction, gelation point was lowered with the increasing the amount of AAEM and HMMM in the ACR.
        4,000원
        45.
        2000.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The consequence analysis for the unconfined vapor cloud explosion(UVCE) accident by the continuous release of butane vapor was performed and effects of process parameters on consequences were analyzed in standard conditions. For the case of continuous release(87.8 kg/s) of butane vapor at 8 m elevated height in the debutanizing process of tile naphtha cracking plant operating at 877 kPa & 346.75 K, we found that combustion ranges of dispersed vapor estimated by HMP model were 11.2~120.2 m and overpressures estimated by TNT equivalency model at 200 m were about 37.35~55.1 kPa. Also, overpressures estimated by Model UVCE I based on advective travel time to XLFL were smaller than those estimated by Model UVCE IIbased on real travel time between XUFL and XLFL. At the same time, damage intensities at 200 m and effect ranges by overpressure could be predicted. Furthermore, simulation results showed that effects of operating pressures on consequences were larger than those of operating temperatures and results of accidents were increased with increasing operating pressures. At this time, sensitivities of overpressures for UVCE accident by the continuous release were about 5 kPa/atm.
        4,200원
        46.
        2000.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Quater polymer(MBHA) containing two types of acrylic functional group, acetoacetoxyethyl methacrylate(AAM) and 2-hydroxyethyl acrylate was prepared. Then, the MBHA was blended with polyisocyanate type Desmodur IL as a curing agent. Thereafter the mixture was cured at room temperature to get high solid acrylic/polyisocyanate. The MBHA was synthesized at 150℃ for 6 hours typically, and the final conversion reached 87-88%. Lowering Tg and increasing AAM amount in the MBHA resulted in high value of conversion. There was no difference in conversion with the variations of OH values. From the results of physical property tests, MIHS coating was proved to be a good automotive top-coating material.
        4,000원
        47.
        2000.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The selective catalytic reduction(SCR) of nitric oxide by ethane in the presence of oxygen was investigated on Cu-ZSM-5, Co-ZSM-5 and Ga-ZSM-5 catalysts over a range of 400, 450 and 500℃. The catalysts were prepared by ion-exchange method. The composition of the reactant gases were 1000 ppm of NO, 1000 ppm of C2H6 and 2.5% of O2, and the reaction was conducted in a fixed-bed reactor at 1 atm. For the 20wt% Co-ZSM-5(50) catalyst, the NO conversion reached up to 100%, while the C2H6 conversion and the CO selectivity were about 50% and 25%, respectively, at 450℃. For the 20wt% Cu-ZSM-5(50) catalyst, the NO conversion and the C2H6 conversion were about 80% and 100%, respectively, but there was no CO produced. The metal ion-exchanged ZSM-5 catalysts exhibited a tendency to increase the NO conversion with the Si/Al ratio of the ZSM-5, that is, NO conversion was inversely proportional to the acidity of the catalysts. But, the effect of the acidity on NO conversion was not so large. From the XRD results of the catalysts before and after SCR reaction it was found that there was no structural change.
        4,000원
        48.
        1991.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        식엽성 삼림해충인 오리나무잎벌레와 사철나무알락명나방, 회양목명나방에 대한 곤충병원성 선충, Steinernema carpocapsae와 Heterorhabditis bacteriophora의 살충력을 알아보기 위하여 실내 검정한 결과 선충의 조유, 농도, 기주에 따라 차이는 있었으나 높은 치사력을 보았다. 오리나무잎벌레인 경우 S.carpocapsae를 유충 한 마리당 25~100마리/ml 농도로 엽상에 처리했을 때 1령충 85.04.1~100%, 2령충 80.05.8~100%, 3령충 65.010.8~100%의 치사율을 보였으며, H. bacteriophora 10~40마리/ml 처리에서는 1령충 82.56.9~100%, 2령충 77.54.7~100%의 치사율을 나타내었다. 사철나무 알락명나방은 유충 gs마리당 S. carpocapsae 5~80마리/ml 처리에서 98.91.1~100%, H. bacteriophora 2~40마리/ml 처리에서는 26.75.1~74.56.2%의 치사율을 나타내었으며, 회양목명나방은 유충한마리당 S. carpocapsae 20~80마리/ml 처리구에서 97.81.5~100%, H. bacteriophora 10~40마리/ml 처리구에서 92.06.2~98.91.1%의 살충력을 보였다.
        4,000원
        49.
        2000.08 KCI 등재 서비스 종료(열람 제한)
        To improve CO2 permselectivity, a modified silica membrane was prepared by chemical vapor deposition with tetraethoxysilane(TEOS)-ethanol-water, and TEOS-ethanol-water-HCI solution at 300-600℃. The silica was effectively deposited in the mesopores of a γ-alumina film coated on a porous α-alumina tube by evacuating the reactants through the porous wall. In this membrane, CO2 interacts, to some extent, with the pore wall, and CO2/N2 selectivity then exceeds the value of the Knudsen diffusion mechanism, while the membrane derived from TEOS alone has no CO2 selectivity. The silica membrane prepared from TEOS-ethanol-water-HC1 solution showed that CO2 permeance was 2.5×10-7㏖/s-1. m-2. Pa-1 at 30℃ and CO2/N2 selectivity was approximately 3. The CO2 permeance and selectivity was improved by enlarging the surface diffusion with modification of chemical affinity of the silica pores.
        50.
        1999.04 KCI 등재 서비스 종료(열람 제한)
        For effective CO2 separation using pore size controlled membrane, silica was deposited in the mesopores of a γ-alumina film by chemical vapor deposition of tetraethoxysilane (TEOS) and phenyl-substituted ethoxysilanes at 773-873K. The membranes prepared with phenyl-substituted ethoxysilanes were calcined to remove the phenyl group and control the pore size. The gas permselectivity of prepared membranes was evaluated by using H2, CO2, N2, CH4 and C3H8 single component and a mixture of CO2 and N2. The membranes produced using TEOS contained micropores having permselectivity only to hydrogen, but the phenyl-substituted ethoxysilane derived membranes possessed micropores which are recognizable molecules of CO2, N2 and CH4. In the diphenyldiethoxysilane-derived membrane, the CO2 permeance and selectivity of CO2/CH4 were 10-6 ㎥(STP)·m-2·s-1·kPa-1 and 11, respectively. Therefore, the use of phenyl-substituted ethoxysilane was effective in controlling micropore size for CO2 separation.
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