The 300 concrete silo systems installed and operated at the site of Wolsong nuclear power plant (NPP) have been storing CANDU spent nuclear fuel (SNF) under dry conditions since 1992. The dry storage system must be operated safely until SNF is delivered to an interim storage facility or final repository located outside the NPP in accordance with the SNF management policy of the country. The silo dry storage system consists of a concrete structure, liner steel plate in the inner cavity, and fuel basket. Because the components of the silo system are exposed to high energy radiation owing to the high radioactivity of SNF inside, the effects of irradiation during long-term storage must be analyzed. To this end, material specimens of each component were manufactured and subjected to irradiation and strength tests, and mechanical characteristics before and after irradiation were examined. Notably, the mechanical characteristics of the main components of the silo system were affected by irradiation during the storage of spent fuel. The test results will be used to evaluate the long-term behavior of silo systems in the future.
This study investigated the surface tension and foaming properties of the hot-water extracts of pumpkin leaf and chickpea, as well as the effects of the plant hot-water extracts on white pan bread baking. Propylene glycol alginate (PGA), a synthetic emulsifier widely used in bakery, was used as a control. Pumpkin leaf water extract showed lower surface tension and comparable foaming capacity, compared with chickpea water extract and PGA solution when total solid 0.15% (w/w). Chickpea water extract showed the highest foam stability when total solid 0.15% (w/w). The dough was found to have a weak gel structure, and its viscoelastic properties were not significantly influenced by adding 0.05% or 0.15% (w/w) (based on total solid content) plant water extracts or PGA. The specific volume of the bread increased, and the baking loss was reduced by adding the two plant water extracts of total solid 0.15% (w/w). The hardness and chewiness of the bread crumb were reduced to a level comparable to the crumb containing 0.05% (w/w) PGA. The results showed that the pumpkin leaf water extract could be an effective natural emulsifier with a high phenolic content for bakery products.
Nuclear Forensics is recognized as a essential component in the nuclear non-proliferation verification sector by the international community. It is being advanced under the leadership of the IAEA, the U.S., and the EU. Both the U.S.’s Lawrence Livermore National Laboratory (LLNL) and the international collaborative organization, the Nuclear Forensics International Technical Working Group (ITWG), have proposed to establish a relationship between the production timing and radiochronometry of nuclear materials or samples to utilize in the field of nuclear forensics. Radiochronometry of nuclear materials is calculated based on the Bateman equation, incorporating factors with uncertainties derived from tests, experiments, and analyses. The results from the nuclear activity radiochronometry also encompass uncertainties, affecting their reliability. This study examined the mathematical uncertainty calculations related to the results of nuclear activity radiochronometry, focusing on calculation methods, contribution rates per factor, and sensitivities. Uncertainty factors for the Bateman equation-based radiochronometry were observed in the decay constants for each nuclide type and the uncertainty in the radioactive ratio of the tracer nuclide. The sensitivity for each factor revealed that the uncertainty in the radioactive ratio of the signature nuclide contributed more significantly than the uncertainty in decay constants for each nuclide type. Each factor displayed a distinct sensitivity curve relative to the radioactive ratio. As it approaches a radioactive equilibrium, the sensitivity tends to increase infinitely, indicating a corresponding trend of infinite increase in uncertainty. Because the time and curve shape to reach radioactive equilibrium vary depending on the signature nuclide, it’s essential to choose an appropriate signature nuclide based on the anticipated period and analysis requirements for nuclear activity radiochronometry. However, radiochronometry using mathematical methods is limited to the relationship between parent and daughter nuclides, presenting the potential for underestimation of uncertainty factors like decay constants. Future research will need to focus on uncertainty calculation methods through computational simulations, especially using the Monte Carlo method, to overcome the limitations of mathematical approaches and potential underestimations.
본 연구는 관상가치가 있는 자생 참두메부추와 갯부추를 절화소재로 이용하고자 수행되었다. 실험은 절화가 수확된 직후, gibberellic acid(GA3) 50, 75, 100mg·L-1, silver thiosulfate(STS) 0.1, 0.3, 0.5mM, 8-hydroxyquinoline sulfate(8-HQS) 25, 50, 100mg·L-1, 그리고 시중에 판매되 고 있는 Chrysal 8mL·L-1, Floralife 10mL·L-1의 보존용액 에 처리되었다. 참두메부추의 절화수명 연장에는 Chrysal 보 존용액 처리가 가장 효과적이었으며 다음으로 75mg·L-1 GA3 처리가 효과적이었다. 한편 8-HQS와 STS는 참두메부추의 절화수명을 단축하고 줄기가 갈변하는 등의 부정적인 영향을 끼쳤다. Chrysal과 더불어 Floralife 보존용액 처리는 절화 참두메부추의 상대 생체중변화율을 높이는데 효과가 있었다. 반면 갯부추는 100mg·L-1 GA3 처리에서 절화수명이 유일하 게 7일까지 연장되었다. GA3 보존용액 처리를 제외한 다른 처리에서 갯부추의 절화수명은 증류수인 대조구보다 비슷하 거나 약간 높은 수준이었다. 절화 갯부추의 수분흡수율은 실 험 초반 100mg·L-1 8-HQS 처리에서, 상대 생체중변화율은 Chrysal 보존용액 처리에서 가장 높게 조사되었으나 두 처 리 모두 절화수명이 유의하게 연장되지 않았다. 갯부추는 100mg·L-1 GA3 처리에서 절화수명을 비롯한 절화품질이 가 장 우수하였다.
This study was conducted at the National Institute of Animal Science (NIAS) from 2010 to 2017 to develop a late-maturing variety with high productivity for cultivation in the southern region of South Korea. The new variety of Italian ryegrass, ‘IR901’, was a late-maturing variety, and its heading date was 22 May, 17 days later than that of the control variety ‘Kowinearly’. ‘IR901’ had a flag leaf width of 11.2 mm, flag leaf length of 31.8 cm, and plant length of 103 cm on its heading date. The combined average dry matter yield of ‘IR901’ in all three adaptability evaluation regions (Cheonan, Pyeongchang and Haenam) was 7,747 kg/ha, which was similar to that of the ‘Kowinearly’ variety (7,734 kg/ ha). However, the average dry matter yield over three years in Cheonan and Pyeongchang was 82% and 96%, respectively, compared to that of the control, which was most likely because of the poor cold tolerance of ‘IR901’. By contrast, in Haenam, in the southern region, the average dry matter yield of ‘IR901’ was 19% higher than that of the ‘Kowinearly’ variety. The proportions of crude protein (CP), total digestible nutrients (TDN), acid detergent fiber (ADF), and neutral detergent fiber (NDF) in ‘IR901’ were 8.6%, 59.7%, 36.9%, and 54.8%, respectively; the proportions were 0.2% lower, the same, the same, and 2.5% lower than those in the ‘Kowinearly’ variety. The determined in vitro dry matter digestibility (IVDMD) of ‘IR901’ was 72.2% higher than that of ‘Kowinearly’ (67.2). In general, of the two varieties, the forage quality of ‘IR901’ was marginally superior to that of ‘Kowinearly’.
Inflammation is a protective mechanism against pathogens, but if maintained continuously, it destroys tissue structures. Aggregatibacter actinomycetemcomitans is a gram-negative, facultative anaerobic bacterium often found in severe periodontitis. A. actinomycetemcomitans invades epithelial cells and triggers inflammatory response in the immune cells. In this study, we investigated the effect of water-soluble rosehip extract on A. actinomycetemcomitansinduced inflammatory responses. A human monocytic cell line (THP-1) was differentiated to macrophages by phorbol 12-mystristate 13-acetate treatment. The cytotoxic effect of extract was determined using the 3-(4,5-dimethylthiazol-2- yl)-2,5-diphenyltetrazolium bromide assay. The effects of extract on bacterial growth were examined by measuring the optical densities using a spectrophotometer. THP-1-derived macrophages were infected A. actinomycetemcomitans after extract treatment, and culture supernatants were analyzed for cytokine production using enzyme-linked immunosorbent assay. Protein expression was measured by western blotting. Extract was not toxic to THP-1- derived macrophages. A. actinomycetemcomitans growth was inhibited by 1% extract. The extract suppressed A. actinomycetemcomitans-induced tumor necrosis factor-α, interleukin (IL)-1β, and IL-8 production. It also decreased mitogen-activated protein kinase (MAP kinase) and nuclear factor-κB (NF-κB) phosphorylation. Moreover, the extract inhibited the expression of inflammasome components, including nucleotide-binding oligomerization domain-like receptor pyrin domain-containing protein 3, Absent in Melanoma 2, and apoptosis associated speck-like protein containing a CARD. And cysteine-aspartic proteases-1 and IL-1β expression were decreased by the extract. In summary, extract suppressed A. actinomycetemcomitans growth and decreased inflammatory cytokine production by inhibiting activation of MAP kinase, NF-κB, and inflammasome signaling. Rosehip extract could be effective in the treatment of periodontal inflammation induced by A. actinomycetemcomitans infection.