A 2D axisymmetric numerical analysis was performed to study the characteristics of charge process inside solar thermal storage tank. The porosity and heat transfer coefficient of filler material as well as inlet velocity of heat transfer fluid are selected as simulation parameters. The porosity is varied as 0.2, 0.5, and 0.8 to account for the effect of filler granule geometry. Two levels of the heat transfer coefficient is adopted to assess the heat transfer between heat transfer fluid and filler material. The inlet velocity is varied as 0.00278, 0.0278, and 0.278m/s. As both of the porosity and the heat transfer coefficient increase, the discrepancy of the temperature distributions between the filler and heat transfer fluid decreases. As the inlet velocity increases, the penetration depth of the heat transfer fluid increases proportionally.
A 2D axisymmetric numerical analysis was performed to study the characteristics of charge process inside solar thermal storage tank. The interfacial area density and inertial resistance of filler material are selected as simulation parameters. The interfacial area density is varied as 800, 2000, and 4000 1/m. The inertial resistance is varied as 1, 3, and 5 1/m. When the interfacial area density increases from 800 to 4000 1/m, the discrepancy of the temperature distributions between the filler and heat transfer fluid decreases. As inertial resistance increases from 1 to 5, both of the temperature and fluid flow pattern changes considerably.
PTMSP에 20 wt% PMMH dendrimer와 10, 20, 30, 40 wt% NaY zeolite를 가하여 PTMSP-PMMH-NaY zeolite 복합막을 제조하였다. 복합막의 물리화학적 특성을 FT-IR, TGA, SEM을 사용하여 조사하였고, H2와 N2 기체에 대한 투과도와 선택도 성질을 고찰하였다. PTMSP-PMMH-NaY zeolite 복합막의 투과도는 zeolite 함량이 증가함에 따라 증가하였고, 수소와 질소의 투과도는 각각 3,950~592,000 barrer와 1,550~143,000 barrer를 보였다. 질소에 대한 수소의 선택도는 0~30 wt%에서는 뚜렷한 차이가 나타나지 않았고, 30~40 wt%에서는 2.2~4.2 범위로 증가하는 경향을 보였다.
Studies were carried to evaluated the influence of storage method by temperatures and fillers on yield and quality of seed rhizome in turmeric. Seed rhizome was stored at styrofoam box filled with rice hull and sand (3:1) or vermiculite for 30, 60 and 90 days at different temperatures (5, 10 and 15℃. compared to traditional method (rhizome only). Parameters were obtained for weight loss, cold injury, percentage of decayed in stored rhizome during storage periods. Also, the germination, growth pattern and yield from stored rhizome has been investigated. It was confirmed that storage of turmeric in stored with filled with vermiculite helps in prevention of rhizomes from microbial and fungal attack. The storage of rhizomes in styrofoam box without any filler at low temperature below 10℃. is not advocated due to heavy losses weight and decayed in management of postharvest for turmeric rhizome. Germination percentage, growth pattern and yield was maximum for rhizomes stored at styrofoam box filled with vermiculite for 90 days at 15℃. The paper outlines a brief attempt to assess the efficacy of non-chemical methods including optimal storage method (temperature and filler) of control of decay and moisture losses during storage of turmeric.
콘크리트 구조물의 FRP를 이용한 보수보강 시 유기계 접착제인 에폭시 수지를 활용한 부착 공법이 일반적으로 사용되고 있으나 터널이나 하수박스 같은 습기가 많은 지역에서는 부착력이 발현되지 못하여 구조물의 보강 및 내구성에 문제가 있는 것으로 나타나고 있다. 이에 본 연구에서는 시멘트계 충진제를 사용하여 습윤 상태에서 콘크리트 구조물을 보강하고자 하였다. 먼저, 각각의 부착력을 알기 위하여 직접 부착실험을 실험을 통해 무기계 충진제가 습윤상태에서도 KS F 4716 규정에 만족함을 알 수 있었다. 반면, 에폭시 접착제는 포화율 100%에서 부착강도가 0.73, 14일 0.84로 습윤 상태에서의 부착성능에 문제점을 나타내었다. 또한 2차 실험으로 진행된 충진제 두께별 GFRP보강 보의 휨 강도측정에서는 충진제 두께가 10mm, 20mm, 30mmd일 때 각각 113%, 66%, 75%의 보강효과를 보였다. 이에 따라 충진제의 두께가 10mm일 때 안정적인 부착성능을 발휘하는 것을 알 수 있었다.