The purpose of the study was to find an effect of medium chain triglyceride (MCT)diet on the serum lipids and lipoprotein of Sprague-Dawley rats when the were fed with cholesterol. All experiment-groups were fed with different diet such as soybean oil, shortening,MCT and MCT mixed with oil respectively. After fed to each group, the levels of serum lipids and lipoprotein among fed rats were examined and the data from the experiment were compared with a control group. The results obtained from the study are as follows : (1) The average boby weight gain in MCT diet and soybean oil diet groups were lighter than that of the control group, while the food efficiency ratio in each experimental diet group was almost same as than in the control group. (2) Total cholesterol levels in serum of all experimental diet groups were lower than that of the control group except the level in shortening diet group. Especially, the levels of total cholesterol in MCT diet and soybean oil diet groups were significantly lower than that of the control group. (3) VLDL, LDL-cholesterol levels of all experimental groups were almost same except the case of the MCT diet and soybean oil diet group which was significantly low. (4) The ratio of VLDL, LDL-cholesterol to HDL-cholesterol, so called, atherogenic index in serum of MCT and soybean oil diet groups were significantly lower than that of the control group. (5) The ratio of total cholesterol to phospholipids in serum of MCT diet group was decreased, because total cholesterol levels were decreased more than phospolipid levels. (6) The ratio of the serum VLDL, LDL to HDL in MCT diet group. in MCT and soybean oil mixed diet group, and in soybean diet group was decreased. In other wards, it means that the decrease of the serum VLDL, LDL in each group and the increase of the serum HDL.

종래의 thyristor chopper는 reactor가 필수 불가결하여, reactor의 내부저항에 의한 에너지 손실을 피할 수 없다. 본 연구에서는 main thyristor를 commutation하기 위해, commutation capacitor에 충전된 전압을 main thyristor에 역으로 가하여 main thyristor을 commutation하였다. 그 결과 다음과 같은 결론을 얻었다. i) 종래의 thyristor chopper에 필수불가결한 모든 reactor를 제거하여 chopping 작용을 가능케 할 수 있었다. ii) Commutation capacitor에 의해 부하를 통과하지 않고 허비되는 에너지의 67%를 회수할 수 있었다. iii) 본 thyristor chopper의 turn off time은 T=RC ln2에 의해 계산된다

A SCR static breaker was studied on the Resistive and inductive load, then on the overload break circuit using operational Amplifier. In this paper, the principal circuit required for forced commutation was voltage commutation by the introduction of a parallel Capacitor. The results obtained are follows; 1. In thecondition that the tima constant of R-C circuit is larger than the turn off time of SCR, the breaker has low transient phenomena and no recovery vol age. 2. By using OP Amplifier on the load circuit, overcurrent trip point will be able to adjust to the wide range of over current. 3. In the over current qrcuit, the power loss was reduced remarkably.