Injection rate characteristics of biodesel fuels according to the blending ratio was described in this work. The injection rate measuring system based on the Bosch's method was utilized to measure and compare the fuel injection rate characteristics. Three different types of biodiesel which were derived from seed, unpolished-rice, and soybean were blended with the diesel fuel in 20% and 40% of volumetric ratio. The fuel properties, injection mass, and injection rate characteristics were obtained and compared in various injection conditions. It is expected that this observations provide important insights into the effect of fuel properties on the biodiesel fuel injection rate performance in a CI engine

수경재배의 폐암면 처리문제를 해결하고 수입의존도가 높은 육묘용 상토 자재의 개발로 육묘산엽의 발전에 기여하고자 폐암면의 혼합비율을 달리한 플러그용 육묘상토를 조성하여 메리골드의 생육에 대한 효과를 조사하였다. 시판 육묘상토를 대조구로 하고, 시판 육묘상토에 이용되는 코코피트 대신에 폐암면을 10, 30, 50%로 혼합하여 혼합상토를 조제하여 50공 트레이에 파종하고 생육조사를 실시하였다. 메리골드의 발아율은 처리구간에 유의한 차이를 나타내지 않았다. 초장, 엽수, 경경, 엽면적과 지상부 및 지하부의 건물중 및 생체중은 시판상토와 폐암면 50% 혼합 처리구에서 양호하였다. 그러나 폐암면 30 및 10% 혼합처리구에서는 시판상토에 비해서 생육이 낮았는데 그 결과에 대해서는 정확한 원인을 밝힐 수 없었다. 본 실험에서는 폐암면을 플러그용 육묘상토의 자재로서 충분히 활용할 수 있다는 가능성을 보여 주었으며, 폐암면의 적정한 혼합비율에 대해서는 계속적인 실험이 필요한 것으로 생각되었다.

In this study, the fiber blending ratio and strain rate effect on the tensile behavior of hybrid fiber reinforced cement composite was evaluated. Hooked steel fiber and polyvinyl alcohol fiber were used for reinforcing fiber. The fiber blending ratio of HSF+PVA were 1.5+0.5, 1.0+1.0 and 0.5+1.5vol.%. As a results, the tensile strength, strain capacity and fracture toughness of the hooked steel fiber reinforced cement composites were improved by the increase of the bond strength of the fiber and the matrix according to increase of strain rate. However, the tensile stress sharply decreased after the peak stress because of the decrease in the number of straightened pull-out fibers by micro cracks in the matrix around hooked steel fiber. On the other hand, PVA fiber showed cut-off fracture at strain rate 10-6/s with multiple cracks. However, at the strain rate 101/s, the multiple cracks and strain capacity were decreased because of the pull-out fracture of PVA fiber. The HSF1.5PVA0.5 shown the highest tensile strength because the PVA fiber suppressed the micro cracks in the matrix around the hooked steel fiber and improved the pull-out resistance of hooked steel fiber. Thus, DIF of strain capacity and fracture toughness of HSF1.5PVA were greatly improved. In addition, the synergistic response of fracture toughness was positive because the tensile stress was slowly decreased after the peak stress by improvement of the pull-out resistance of hooked steel fiber at strain rate 101/s