MgO based nanocomposite powder including ferromagnetic iron particle dispersions, which can be available for the magnetic and catalytic applications, was fabricated by the spray pyrolysis process using ultra-sonic atomizer and reduction processes. Liquid source was prepared from iron (Fe)-nitrate, as a source of Fe nano-dispersion, and magnesium (Mg)-nitrate, as a source of MgO materials, with pure water solvent. After the chamber were heated to given temperatures (500~), the mist of liquid droplets generated by ultrasonic atomizer carried into the chamber by a carrier gas of air, and the ist was decomposed into Fe-oxide and MgO nano-powder. The obtained powders were reduced by hydrogen atmosphere at 600~. The reduction behavior was investigated by thermal gravity and hygrometry. After reduction, the aggregated sub-micron Fe/MgO powders were obtained, and each aggregated powder composed of nano-sized Fe/MgO materials. By the difference of the chamber temperature, the particle size of Fe and MgO was changed in a few 10 nm levels. Also, the nano-porous Fe-MgO sub-micron powders were obtained. Through this preparation process and the evaluation of phase and microstructure, it was concluded that the Fe/MgO nanocomposite powders with high surface area and the higher coercive force were successfully fabricated.
이 시험은 도입남양재 원목에 부착 또는 서식하는 유해병해충의 방제를 목적으로 실시하는 해수수침소독에 있어 농약의 소요량기준을 설정함을 목표로 실시한 것으로써 결과를 요약하면 다음과 같다. 1. 우리나라에 도입되는 남양재 원목의 평균 길이는 11.12m이었으며 직경은 69.55cm이었다. 2. 원목의 전재적에 대한 부상재적은 평균 이었다. 3. 원목의 전재적에 대한 부상표면적의 비의 값은 2.3356( 신뢰수준)이었다. 4. 원목의 전재종 대 부상표면적에 대한 표본추출오차는 1본선내 원목간의 오차(0.2087)가 10본선간의 오차(0.2952)보다 적었다. 5. 원목 당 농약의 적정소요량은 수동식살포기를 이용하는 경우 0.368cc, 그리고 동력분무기를 이용하는 경우는 0.295cc이었다. 6. 예를 들어 남양재 원목 을 도입하여 동력분무기로 해수수침소독을 실시하는 경우 농약소요량은 다음과 같이 계산된다. .