• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.1
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• pp.40-45
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• 2006

Electrical insulation is one of the most important parts in a high voltage apparatus. Traditionally mineral oils and synthetic esters have been widely used as dielectric coolants for power transformers. Recently, researchers are interested in the environmentally friendly vegetable oil from the environmental viewpoint. This paper reports on the synthesis and characterization of soybean based ester oils. Two different types of soybean based transformer oils, named as methyl ester and isopropyl ester were synthesized. The synthesis of these esters was achieved by transesterification reactions between soybean oil and alcohol in the presence of catalyst. The GC and NMR spectroscopic analysis of the esters have been performed. It was observed that isopropyl ester has better thermal resistance than methyl ester by TGA. Also, two esters have a good breakdown voltage and electrical resistance.

• 제어로봇시스템학회:학술대회논문집
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• 1999.10a
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• pp.248-251
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• 1999

The optimal reaction conditions are determined for a PET process, which consists of transesteriflcation, prepolymerization and polycondensation reactors in series. Based on the simulation results of the reactor system, we scrutinize the cause and effect between the reaction conditions and the final properties of the polymer product. We then select the process variables with significant influence on the properties of polymer as control variables and calculate the optimal reaction conditions by iterative dynamic programming (IDP) algorithm with constraints. A new reaction scheme incorporating reactions for by-products as well as three main reactions is considered in the constrained IDP method.