Separation of high heat generating-radioactive isotopes from spent nuclear fuel is an important issue because it can reduce the final disposal area. As one of the technologies that can selectively separate only high heat generating-radioactive isotopes without dissolving spent fuel, the methods using molten salt have recently attracted attention. Although studies on chemical changes of Sr oxides in molten salts have been reported, they have limitation in that alternative oxide reagents rather than oxide fuel were used. In this study, the separation behaviors of Sr from simulated oxide fuel using various molten salts were investigated. A powder type containing 95.7wt% of U and 0.123wt% of Sr was used as the simulated oxide fuel. LiCl, LiCl-CaCl2, MgCl2, LiCl-KCl-MgCl2 and NaCl-MgCl2 were used as molten chloride salts. The separation of Sr from the simulated oxide fuel was conducted by loading it in porous alumina basket and immersing it in a salt. The concentration of Sr in the salt was measured by ICP analysis after sampling the salt outside the basket using dip-stick technique. The separation efficiencies of Sr from simulated oxide fuel using the salts were compared. Furthermore, the causes of their separation efficiency were systematically investigated.

Buckwheat is well-known as a healthy crop with excellent nutritional and functional superiority mainly because of a high content of flavonoid compounds, specifically, rutin. However, buckwheat-based food products are known to have the reduced levels of rutin by rutin-degrading enzymes that generate quercetin during processing. However, since quercetin has a bitter taste, it may have a negative impact on consumer preferences, consequently retarding the utilization of buckwheat flour to a variety of buckwheat processed foods. Thus, this study was carried out to investigate the levels of rutin and quercetin in the milling fractions of buckwheat flours and also to monitor their changes by a variety of thermal treatments. Native buckwheat was separated into three fractions by sieving with 40 and 100 mesh screens which were designated as >40 M, 40-100 M, and 100 M<, respectively. The levels of rutin were the highest in the 40-100 M milling fraction, followed by <100 M and >40 M. Also, buckwheat flours were subjected to several thermal treatments including steaming and autoclaving. The contents of rutin and quercetin in the resulting buckwheat samples were analyzed by HPLC and the correlations between the flavonoid compounds and thermal treatments were investigated. The addition of water to buckwheat flour in making buckwheat products significantly decreased the levels of rutin while the quercetin content increased. However, the thermal treatments of buckwheat flours distinctly reduced the rutin loss and quercetin was hardly detected. Therefore, this study contributes to enhancing the health functionalities of buckwheat by reducing rutin loss, probably extending use of buckwheat flour to a variety of processed food products.

Phosphorus is an essential and irreplaceable element for all living organisms and its resource is limited. Significant amount of used phosphorus is collected in sewage treatment plant as sludge. Sludge ash after incineration contains about 10% of phosphorus in dry mass basis, which is comparable to phosphate rocks, and it is an important source of phosphorus recovery. Acid and alkali were used to leach phosphorus from sludge ash and compared for their leaching kinetics and performance. Phosphorus leaching by NaOH was fast and 0.2 N and 2 N NaOH leached 49% and 56% of the total phosphorus in the sludge ash at the L/S ratio of 100. Phosphorus leaching by sulphuric acid and hydrochloric were very fast and most of the phosphorus was leached in 5 minutes. In case of sulphuric acid 95% of the total phosphorus in the sludge ash was leached by 0.2 N at the L/S ratio of 100 and 93% was leached by 1 N at the L/S ratio of 10. 1 N hydrochloric acid leached 99% of the total phosphorus at the L/S ratio of 10. The results showed acids were more effective than alkali for phosphorus leaching from sludge ash and hydrochloric acid leached more phosphorus than sulphuric acid.

Soybean has around 20% oil in total seed compound. Fatty acid concentration of soybean oil is about 12% palmitic acid, 4% stearic acid, 23% oleic acid (ω-9), 54% linoleic acid(ω-6) 54% and 8% linolenic acid(ω-3). To improve oxidative stability and quality of oil, the breeding programs mainly focused on reducing saturated fatty acids, increasing oleic acid and reducing linolenic acid in soybean oil. In plant oil, an essential fatty acid omega-3 fatty acid is in the form of α-linolenic acid (ALA) therefore, increasing ALA in soybean oil became one of the breeding goals for human health. In our research group, we have two breeding programs for concentration of ALA in soybean oil. Wild soybeans have almost twice ALA than that in cultivated soybeans. Introgression of alleles from wild soybean to cultivated soybean may lead to the increase of ALA in soybean seed oil for various applications. We developed several backcross populations by elite cultivars x wild soybean to select high ALA with good agronomic traits. In the case of low linolenic acid program, we developed an EMS (ethyl methane sulfonate) mutation population to select low ALA concentration line and found a mutant line with low ALA in seed oil. The scheme for developing high ALA concentration from wild soybean and molecular characterization for low ALA line will be discussed.