Habenaria radiata, commonly known as the Egret Flower, is a critically endangered terrestrial orchid facing rapid population decline due to overharvesting in Korea. Asymbiotic seed propagation offers a promising conservation method for this rare species. This study investigates the effects of different nutrient media on the germination and plantlet development of immature seeds of H. radiata, with the goal of establishing optimal propagation conditions. Among four media types, with the highest germination rate (75.6%) observed on OBTSG medium, followed by 1/2 MS, OMM, and OSGM. Protocorm development varied across media, with OBTSG and OMM supporting the most robust growth. A two-step culture method involving OBTSG for germination followed by OMM for plantlet development proved most effective, achieving an 84.4% survival rate. These findings highlight the importance of media composition and transitioning for successful propagation. The results provide a practical protocol for in vitro propagation, contributing to both in situ and ex situ conservation efforts aimed at preserving H. radiata and other endangered terrestrial orchids.

Seeds of some barberry species have embryo with physiological dormancy that requires a cold stratification for germination. Berberis amurensis Rupr. is a native species of Japan, Korea, the Russian far east, and parts of China. This specific plant is important for its edible fruits and rhizomes with high medicine value. This study aimed to determine the effect of stratification on germination and physiological change of B. amurensis. Seeds were placed on sterilized sand medium moistened with distilled water in 9 cm diameter petri dishes and stored at 4 and 25˚C for 0, 15, 30, 45 and 60 days. Each treatment had 40 seeds per replica, and three repetitions per treatment. Immediately after stratification, total phenolics contents (TPC) was analyzed and seeds incubated at 15/6˚C for 12 weeks. Warm stratification had a significant effect on seed forcing for germination than cold stratification treatment. At 25˚C for 60 days, stratified seed showed highest germination percentage (25.7±4.3%) and germination started in 14 days of the stored period. Whereas TPC was significantly decreased with increasing stored period. Contrastively, cold stratification had no effect on the germination ability. In the same way germination percentage of non-stratified seeds were also zero. The results confirmed that B. amurensis seeds were in a dormant state and warm stratification increased the germination ability by breaking of dormancy.

When decommissioning a nuclear power plant, the structure must be made to a disposable size. In general, the cutting process is essential when dismantling a nuclear power plant. Mainly, thermal cutting method is used to cutting metal structures. The aerosols generated during thermal cutting have a size distribution of less than 1 μm. The contaminated structures are able to generate radioactive aerosols in the decommissioning. Radioactive aerosols of 1 μm or less are deposited in the respiratory tract by workers’ breathing, causing the possibility of internal exposure. Therefore, workers must be protected from the risk of exposure to radioactive aerosols. Prior knowledge of aerosols generated during metal cutting is important to ensure worker safety. In this study, the physical and chemical properties of the aerosol were evaluated by measuring the number and mass concentrations of aerosols generated when cutting SUS304 and SA508 using the laser cutting method. High-resolution aerosol measuring equipment (HR-ELPI+, DEKATI) was used to measure the concentration of aerosols. The HR-ELPI+ is an impactor-type aerosol measuring equipment that measures the aerosol number concentration distribution in the aerodynamic diameter range of 6 nm to 10 um in real-time. And analyze the mass concentration of the aerosol according to the diameter range through the impactor. ICP-MS was used for elemental mass concentration analysis in the aerosol. Analytical elements were Fe, Cr, Ni and Mn. For the evaluation of physical and chemical properties, the MMAD of each element and CMAD were calculated in the aerosol distribution. Under the same cutting conditions, it was confirmed that the number concentration of aerosols generated from both materials had a uni-modal distribution with a peak around 0.1 um. CMAD was calculated to be 0.072 um for both SUS304 and SA508. The trend of the CMAD calculation results is the same even when the cutting conditions are changed. In the case of MMAD, it was confirmed that SUS304 had an MMAD of around 0.1 μm in size for only Fe, Cr and Mn. And SA508, Fe, Cr, Ni and Mn were all confirmed to have MMAD around 0.1 μm in size. The results of this study show that a lot of aerosols in the range of less than 1 μm, especially around 0.1 μm in size, are generated when metal is cut using laser cutting. Therefore, in order to protect the internal exposure of workers to laser metal cutting when decommissioning NPPs, it is necessary to protect from nano-sized aerosols beyond micron size.

There are a lot of types of wild vegetables such as Colocasia esculenta (L.) Schott stem in Korea. However, the consumption of these wild vegetables is restricted because their storage decreased dramatically after harvest. To maintain original quality of vegetables, pre-treatments such as blanching and drying are important. But conditions for these treatments were still not optimized for many vegetables including Colocasia esculenta (L.) Schott stem. Thus, the objective of this study was to set up an optimal pre-treatment method for freezing storage. Colocasia esculenta (L.) Schott stems were peeled and cut equally (10 cm) for sample preparation. Dried samples (D) were dried at 90℃ for 3 h. Blanched samples (B) were blanched in hot water at 100℃ for 2 min. Blanched and dried samples (BD) were blanched and dried as same protocol. Physicochemical properties were analyzed to evaluate the quality including texture, moisture content, total color difference and viable cell count. Raw sample had 6.85 kg/cm 3 of hardness and 78.75 of chewiness whereas B was 6.83 kg/cm 3 of hardness and 7.8 of chewiness. B had the similar value compared to raw samples. Moisture content of raw sample was 94.4% and that of B was 94.1%, though there were not any significant differences between them. ΔE value of B showed lower value than those of the others. Viable cell counts and total coliforms were not detected after treatment, while raw sample had 5.39 log CFU/g of viable cell count without total coliform. Therefore, pre-treatments are essential for microbial safety of samples. All results considered, it is supposed that blanching is the optimal pre-treatment to sustain its original quality of Colocasia esculenta (L.) Schott stems before freezing.