In this study, the expression of genes related to fruit ripening was investigated using realtime PCR. The study aimed to determine the effective conditions of calcium compounds (Calcium citrate, calcium chloride, calcium nitrate, GH-Ca, OS-Ca) and chitosan treatment to extend the shelf-life in the ‘Kumhong’ nectarine and ‘Madoka’ peach fruits. In this study, in the ‘Kumhong’ and ‘Madoka’ fruits, the expression of genes related to cell wall degradation, pectin lyase (PL), polygalacturonase (PG), and pectin methylesterase (PME), was inhibited by calcium, chitosan, or a mixture (Chitosan+CaCl2) treatment. In ‘Madoka’ peach, although the expression of the PG gene was suppressed at pre-harvest Ca and chitosan treatment, the expression of the PL gene was induced at pre- and post-harvest Ca and chitosan treatment compared to the control. The spray of calcium, chitosan itself, or a mixture (Chitosan+ CaCl2) on the trees at the ripening stage and harvested fruits can extend the shelf-life by suppressing the expression of cell wall degrading enzymes genes (PL, PG, PME) in ‘Kumhong’ nectarine and ‘Madoka’ peach tree. These results provide valuable information for the development of technology for the extension of the shelf-life of peach and nectarine fruits.
There are many types of foam molding methods. The most commonly used methods are the pressure foaming method, in which foam resin is mixed with a foaming agent at high temperature and high pressure, and the normal pressure foaming method, which foams at high temperature without pressure. The polymer resins used for foaming have different viscosities. For foaming under normal pressure, they need to be designed and analyzed for optimal foaming conditions, to obtain resins with low melt-viscosity or a narrow optimal viscosity range. This study investigated how changes in viscosity, molding temperature, and cross-link foaming conditions affected the characteristics of the molded foam, prepared by blending rubber polymer with biodegradable resin. The morphologies of cross sections and the cell structures of the normal pressure foam were investigated by SEM analysis. Properties were also studied according to cross-link/foaming conditions and torque. Also, the correlation between foaming characteristics was studied by analyzing tensile strength and elongation, which are mechanical properties of foaming composites.
영농형 태양광 발전은 농경지에서 작물을 생산함과 동시에 식물이 요구하는 광포화점 이상의 광을 이용하여 전기를 생산 하는 시스템이다. 새로운 농가 소득원의 개발을 위하여 포도 원에 태양광 패널을 설치하고 수체의 생육과 과실 발육 특성 을 평가하여 영농형 태양광의 활용성을 탐색하고 향후 재배기 술을 개발하는 데 필요한 정보를 제공하고자 연구를 진행하였 다. 152 × 68 × 3.5cm 크기의 구조물에 영농형 150Wp (36cell) 모듈을 포도나무 재식열에 따라 배치하고, 과원의 환경과 식물 생육을 분석하였다. 무처리에는 겨울철 풍속이 0.4-0.6m·s-1 에 도달하였으나, 시설 설치구에서는 0.01-0.02m·s-1에 머 물렀다. 삽수 수피의 탄수화물함량은 시설 설치구에서 183- 184m·g-1으로 무처리구(181-198mg·g-1)에 비해 큰 차이가 없으며 삽수의 발아율도 큰 차이가 없었다. 잎의 엽록소의 함 량은 처리구에서 높게 나타났다. 수확후 과실의 특성으로는 과립중, 과방중, 당도, 과피색의 차이는 없었다. 다만 시설구 에서 숙기가 5-7일정도 늦어졌으며, 변색기의 착색에는 약 간 차이가 있었다. 영농형 태양광 패널을 설치한 과원에서 포 도나무와 과실의 발육은 유의차가 없었고, 설치구에서 착색 이 지연되었다. 이러한 결과는 향후 포도원에서 영농형 태양 광 시설을 설치하여 포도를 생산하는 기술 개발에 필요한 정 보로 활용될 수 있을 것이다.