The bio reactors with high efficiency using ejector are widely used in gas-liquid system, This is also due to the high efficiency in gas dispersion resulting in high mass transfer rate and low power requirements. Thus, the new liquid fertilizer manufacturing equipment composed with aeration tank, cycling tank and circulation pump using an ejector was developed. The aim of this study is to investigate the effect of an ejector on the liquid fertilizer manufacturing equipment and to design the optimal ejector for actual application using CFD analysis and experimental method. The results show that the suction air mass flow rate is increased, as the diameter of driving ejector nozzle is smaller and the position of nozzle is toward the exit of an ejector.

The hydrofoil-tip mixer can be used to create the desired material by mixing the two materials in various industries, especially in the waste water and sewage water treatment. The purpose of this study is to clarify flow characteristics induced by 3 types impellers in a mixing tank by CFD. In this study, flat plate, hydrofoil and hydrofoil-tip type impellers are used and the rotating speeds of impellers are 25, 35, 45 rpm. The results in present study show that hydrofoil-tip type is the most proper impeller for mixing in the waster water treatment tank and reducing required power of rotating impeller. This results can be used for the design of the mixing tank in the waste water treatment system.

The purpose of this study is to investigate the actual field application of the airless paint spraying pump driven by the hydraulic power unit under high pressure condition. The velocity and the pressure distributions are obtained using the turbulent k-ε model. The flow characteristics under design condition of spraying pump was numerically conducted by commercial fluid dynamic code(CFX ver. 13). The numerical analysis was performed by transient technique according to the variation of stroke times, which is changing from 0 to 1 seconds by interval of 0.01. Turbulence model, k-ω SST was selected to quaranty more accurate prediction of oil flow. The ICEM-CFD 13 and CFXMesher, reliable grid generation software were also adapted to secure high quality grid necessary for the reliable analysis. According to the simulation results, the flow rate was supplied to the paint spraying pump is 5l/min. These results are in good agreement with design results and could be applied to the design of the high viscosity paint spraying pump.

목적: 조도가 눈의 굴절력과 동공크기에 미치는 영향을 알아보고자 하였다. 방법: 안질환과 안과 수술경력이 없고 양안 교정시력이 1.0 이상인 평균 20세의 남녀 30명(남자 11명, 여자 19명)을 대상으로 조도 100Lux, 300Lux, 500Lux, 800Lux, 1,000Lux에서 각각 눈의 굴절력과 동공의 크기를 측정하여 보였다. 결과: 우안의 평균 구면 굴절력 변화는 500~800Lux 에서 S=0.03±0.24D, 좌안의 평균 구면 굴절력 변화는 100~300Lux에서 S+0.08±0.24D, 우안의 평균 원주 굴절력 변화는 500~800 Lux에서 C+0.02D, 좌안의 평균 원주 굴절력 변화는 500~800Lux에서 C+0.10D의 변화를 보였다. 또한, 조도에 따른 동공의 크기는 100Lux에서는 6.02㎜, 300Lux에서는 6.04㎜, 500Lux에서는 5.75㎜, 800Lux에서는 4.01㎜, 1,000Lux에서는 3.64㎜로 나타났다. 결론: 조도에 따른 눈의 굴절력 변화는 유의한 차이는 보이지 않았지만, 조도변화의 일부구간에서 구면 및 원주굴절력이 다소 감소하는 경향을 보이는 것으로 나타났다. 또한, 동공크기의 변화는 500Lux부터 동공의 크기가 통계적으로 유의하게 작아짐을 알 수 있었다. 따라서, 이에 대한 검안실 조도의 적절한 기준이 필요할 것으로 사료된다.

The European Economic Community four plate test(EEC 4-plate test, FPT, EU) has been used for monitoring antimicrobial drug residues in meat by Local Veterinary Service Center in Korea. This study was performed to evaluate sensitivity and group specificity of some antimicrobial drugs in FPT and to compare FPT with Charm II test. The minimal detectable levels of targeted antimicrobial drugs tested with standard solutions were 0.025-1.0 ppm for 7 beta-lactams, 0.5-1.0 ppm for 4 aminoglycosides, 0.05-0.5 ppm for 5 macrolides, 0.05-0.25 ppm for 3 tetracyclines and 0.25-1.0 ppm for 6 sulfonamides. In identification of the families, five families of antimicrobial drugs were identified. In this case, beta-lactams, aminoglycosides, macrolides, tetracyclines and sulfonamides could be detectable. In comparison of FPT and Charm II test, the results of FPT were not accord with those of Charm II test having the group specificity of seven families of antimicrobial drugs in meat samples except some families like tetracyclines.