It has been known that as oxide layer (ZrO2) forms on the nuclear fuel cladding during irradiation in nuclear power plants, the corrosion kinetics are influenced by various parameters such as chemical environments. One of those environments, crud deposition driven by coolant chemistry has an adverse effect on the formation of oxide (ZrO2) and leads to increase thickness of the layer. In this study, crud formation was performed through loop experiment equipment on the surface of intentionally-made oxide layer (ZrO2) on cladding tubes and then the composition and characteristics of cruds were examined for the investigation of nuclear power plant environment. As a result, various cruds in composition and microstructure were formed depending on the exquisite methods and conditions such as metal ion concentration.

Nanopowders provide better details for micro features and surface finish in powder injection molding processes. However, the small size of such powders induces processing challenges, such as low solid loading, high feedstock viscosity, difficulty in debinding, and distinctive sintering behavior. Therefore, the optimization of process conditions for nanopowder injection molding is essential, and it should be carefully performed. In this study, the powder injection molding process for Fe nanopowder has been optimized. The feedstock has been formulated using commercially available Fe nanopowder and a wax-based binder system. The optimal solid loading has been determined from the critical solid loading, measured by a torque rheometer. The homogeneously mixed feedstock is injected as a cylindrical green body, and solvent and thermal debinding conditions are determined by observing the weight change of the sample. The influence of the sintering temperature and holding time on the density has also been investigated. Thereafter, the Vickers hardness and grain size of the sintered samples have been measured to optimize the sintering conditions.

Mutagenesis approach in combination with whole genome sequencing has become an import role in genetic and molecular biological study and breeding of crop plants. In this study, we screened the fast neutron M4 10,000 soybean mutant plants based on morphological phenotypes of agronomically important traits and characterized the mutant of interest using resequencing. Fast neutron radiation has been known to be a very effective mutagen to cause large deletion in genome. The screened mutant showed abnormal phenotypes in plant heights, seed sizes, color of leaves, number of leaves, maturity and number of branches etc. Among them, the mutant displaying short plant height and bush type of growth habit was selected for identification of the altered genomic regions. Analysis of deletion sites of genome in interesting soybean mutant was performed using next generation sequencer Illumina Hi-seq. Mutant sequence reads generated by paired-end shotgun library were mapped on a draft soybean reference soybean (G. max cv. Williams 82). The paired-end DNA sequences of 21.6 Gb produced by Illumina Hi-seq produced 21 fold sequence depth. Among the predicted deletion sites, total 3 deletion regions confirmed by PCR. Glyma03g02390 gene and Glyma03g03560 gene were involved in the deletion regions. Glyma03g02390 gene was related to AMP binding, catalytic activity, cofactor binding and metabolic process of cell growth and Glyma03g03560 gene was concerned to oxygen binding, defense response to bacterium, and especially process of indole acetic acid (IAA) biosynthesis. These genes detected in this mutant will be studied about their molecular function in stunted phenotype.

“Ilyeop” (Perilla frutescens (L.) Britton), a new cultivar for leaf vegetable, was developed from a cross between Ipdeulkkae1 and YCPL187 at the National Yeongnam Agricultural Experiment Station, RDA, in 2001. For the cultivation of leaf vegetable perilla, the plants are grown with a spacing of 10 × 5 cm between rows and plants and all branches are removed to harvest uniform leaves from main stem, indicating that the amount of the next harvesting leaf is a important characteristic for the growth of the plant. “Ilyeop” grows vigorously and yields high quality leaf with higher amount of the next harvesting leaves composed with a check cultivar, “Ipdeulkkae1”. “Ilyeop” has five days of earlier seed maturity (Oct. 24) than that of “Ipdeulkkae1” under natural condition, less chance of frost damage is expected. The flowering date of “Ilyeop” is same with that of “Ipdeulkkae1” in winter cultivation with night break treatment.

“Bora” is a new perilla (Perilla frutescens (L.) Britton) cultivar developed from a cross between Ipdeulkkae1 and YCPL199 at National Yeongnam Agricultural Experiment Station, RDA, in 2001. Purple backside leaf color is one of the most important characteristics for the high quality perilla leaf. “Bora” has purple backside leaf color in all climate condition, while a check variety, Ipdeulkkae1 has too light color during summer season or in high temperature condition. “Bora” matures at October 18th and has 79 cm of the stem length, shorter than that of Ipdeulkkae1. Although leaf yield is 11% less than that of a check variety Ipdeulkkae1, the harvested leaf number of “Bora” is similar with that of Ipdeulkkae1. The cultivar is appropriable in all area of Korea for the leaf harvesting cultivation whereas it is restricted to southern part of Korea South Gyeongsang and South Jeola provinces, for the seed harvesting cultivation.

‘Namcheondeulkkae’ was developed as a new vegetable perilla variety using the pure line selection from Milyang local strains at the National Yeongnam Agricultural Experiment Station (NYAES), Rural Development Administration in 1998. The advanced and regio