This study was performed to select the optimum combinations of a cropping system by using kenaf and four forage crops on the reclaimed land, Saemangum, in Korea. First, kenaf was cultivated for 168 days from May to mid October, and then, four forage crops, such as barley, Italian ryegrass (IRG), rye, and triticale, were cultivated from late October to May next year. The agronomic performances and physiochemical analyses of kenaf and four forage crops were investigated. The kenaf yield on the reclaimed land was 2.4 t/10a compared to the upland field’s yield of 3.25 t/10a. The germination percentage of IRG was the highest in the solution of 0.3% NaCl in comparison with the other forage crops. The agronomic performances of forage crops were estimated twice during the vegetative period. A significant difference in dry weight was observed in barley at 30 days of sowing. On second investigation at 160 days of sowing, the highest plant height was found in rye and the dry weight of IRG was the lowest. At harvest time, rye showed a significant difference in the plant height of 159.8 cm and fresh weight was the highest in IRG. At this time, there was a big difference in the dry weight of rye and IRG compared to barley and triticale. With respect to the K+/Na+ ratio, rye showed the highest increase in the K+/Na+ ratio over the other crops when cultivated on the reclaimed land. With respect to the effect of the kenaf extract on the four winter crops, the extract from kenaf reduced the germination of IRG by 81.7%. With respect to the silage quality estimation, there was no increase in barley in terms of total digestible nutrient (TDN). Taken together, IRG would be useful for the silage and rye would be useful for green manure on the reclaimed land after cultivating kenaf.

Extensive studies have been conducted on thermal conductivity of bentonite buffer materials, as it affects the safety performance of barriers engineered to contain high-level radioactive waste. Bentonite is composed of several minerals, and studies have shown that the difference in the thermal conductivity of bentonites is due to the variation in their mineral composition. However, the specific reasons contributing to the difference, especially with regard to the thermal conductivity of bentonites with similar mineral composition, have not been elucidated. Therefore, in this study, bentonites with significantly different thermal conductivities, but of similar mineral compositions, are investigated. Most bentonites contain more than 60% of montmorillonite. Therefore, it is believed that the exchangeable cations of montmorillonite could affect the thermal conductivity of bentonites. The effect of bentonite type was comparatively analyzed and was verified through the effective medium model for thermal conductivity. Our results show that Ca-type bentonites have a higher thermal conductivity than Na-type bentonites.

항공 및 지리 공간 기술은 연구자 및 농업관련 실무자들이 더욱더 쉽게 접근할 수 있게 되었으며, 이러한 기술은 농업과 임업에 있어 현재 병해충 관리의 변화에 중추적인 역할을 할 수 있다. 지난 20년 동안 위성, 유무인항공기, 스펙트럼 센서들, 정보 시스템 및 자동화 현장 장비들의 기술들은 병해충을 감지하고, 특정 지점에 대한 병해충을 방제하는데 사용되어져 왔다. 빅 데이터 기반한 인공 지능과 함께 항공 및 지리 정보 기술의 가용 함에도 불구하고 이러한 기술을 사과 IPM에 적용하는 것은 아직 실현되지 않았다. 본 논문은 사과연구소에서 수행한 사례 연구를 통해 사과 IPM 개선에 활용할 수 있는 항공 및 지리 정보기술의 발전과 한계에 대해 논하고자 한다.

The Korea Atomic Energy Research Institute (KAERI) has developed geological repository systems for the disposal of high-level wastes and spent nuclear fuels (SNFs) in South Korea. The purpose of the most recently developed system, the improved KAERI Reference Disposal System Plus (KRS+), is to dispose of all SNFs in Korea with improved disposal area efficiency. In this paper, a system-level safety assessment model for the KRS+ is presented with long-term assessment results. A system-level model is used to evaluate the overall performance of the disposal system rather than simulating a single component. Because a repository site in Korea has yet to be selected, a conceptual model is used to describe the proposed disposal system. Some uncertain parameters are incorporated into the model for the future site selection process. These parameters include options for a fractured pathway in a geosphere, parameters for radionuclide migration, and repository design dimensions. Two types of SNF, PULS7 from a pressurized water reactor and Canada Deuterium Uranium from a heavy water reactor, were selected as a reference inventory considering the future cumulative stock of SNFs in Korea. The highest peak radiological dose to a representative public was estimated to be 8.19×10-4 mSv‧yr-1, primarily from 129I. The proposed KRS+ design is expected to have a high safety margin that is on the order of two times lower than the dose limit criterion of 0.1 mSv‧yr-1.