The development of separation method of radioactive tritium is imperative for treating tritiumcontaminated water originating from nuclear facilities. Polymer electrolyte membrane electrolysis technology represents a promising alternative to conventional alkaline electrolysis for tritium enrichment. Nevertheless, there has been limited research conducted thus far on the composition of membrane electrode assemblies (MEAs) specifically optimized for tritium separation, as well as the methods used for their fabrication. In this study, we conducted an investigation aimed at optimizing MEAs specifically tailored for tritium separation. Our approach involved the systematic variation of MEA components, including the anode, cathode, porous transport layer, and electrode formation method. The water electrolysis efficiency and the H/D separation factor in deuterated water (1%) were evaluated with respect to both the preparation method and the composition of the MEA. To assess the long-term stability of the MEAs, changes in cell voltage, resistance, and the active electrode area were analyzed using impedance analysis and cyclic voltammetry. Furthermore, we examined H/D separation factor both before and after degradation. The results showed that MEAs with different anode/cathode configurations and electrode formation methods improved the electrolysis efficiency compared to commercial MEAs. In addition, the degree of change in the resistance value was also different depending on the electrode formation method, indicating that the electrode formation method has a significant impact on the stability of the electrolysis system. Therefore, the study showed that the efficiency and long-term stability of the water electrolzer can be improved by optimizing the MEA fabrication method.

For decontamination and quantification of trace amount of tritium in water, an efficient separation technology capable of enriching tritium in water is required. Electrolysis is a key technology for tritium enichment as it has a high H/T and D/T separation factors. To separate tritium, it is important to develop a proton exchange membrane (PEM) electrolyzer having high hydrogen isotope separation factor as well as high electrolyzer cell efficiency. However, there has not been sufficient research on the separation factor and cell efficiency according to the composition and manufacturing method of the membrane electrode assembly (MEA) Therefore, it is necessary to study the optimal composition and manufacturing method of the MEA in PEM electrolyzer. In this study, the H/D separation factor and water electrolysis cell efficiency of PEM electrolyzer were analyzed by changing the anode and cathode materials and electrode deposition method of the MEA. After the water electrolysis experiment using deionized water, the D/H ratio in water and hydrogen gas was measured using a cavity ring down spectrometer and a mass spectrometer, respectively, and the separation factor was calculated. To calculate the cell efficiency of water electrolysis, a polarization curves were obtained by measuring the voltage changes while increasing the current density. As a result of the study, the water electrolyzer cell efficiency of the MEA fabricated with different anode/cathode configurations and electrode formation methods was higher than that of commercial MEA. On the other hand, the difference in H/D separation factor was not significant depending on the MEA fabrication methods. Therefore, using a cell with high cell efficiency when the separation factor is the same will help construct a more efficient water electrolysis system by lowering the voltage required for water electrolysis.

Cymbidium ‘Aroma Pink’는 국립원예특작과학원에서 2017년 도에 육성한 신품종으로, 2000년에 C. Lucky Rainbow ‘Lapin Hot’과 C. eburneum을 인공교배하여 개발된 품종이다. 교배 후 기내파종과 하우스 순화를 통해 120개의 실생묘를 얻었고, 그 중 화색, 엽형, 꽃대 및 생육특성 등을 고려하여 3계통을 1차 선발하였고, 2011년부터 2016년까지 특성 검정을 통하여 품종의 안정성과 균일성을 확인하였다. 그 결과, 최종적으로 ‘00-1174-100’한 계통을 선발하였고 ‘원교 F1-62’로 계통명을 부 여한 후, ‘Aroma Pink’로 명명하였다. ‘Aroma Pink’ 품종은 백 색 바탕에 꽃받침 일부가 연한 분홍색, 순판 가운데가 노란색 을 띄며 화형은 꽃잎과 꽃받침이 약간 안쪽으로 오므라드는 안 아피기 형태이며 꽃의 길이와 폭은 6.1cm, 5.2cm로 작은 편이다. 전체적으로 동그란 화형과 중형종 크기는 모본인 C. Lucky Rainbow ‘Lapin Hot’과 유사하나 진한 적색 순판 대신 부본의 노란색 순판과 화색을 닮아 강렬한 느낌보다는 전체적으로 화 사한 느낌을 준다. 꽃대는 평균 2.9개 발생하고 화서당 꽃 수 가 6.5개로 적은 편에 속하지만, 부본인 C. eburneum 원종의 향기를 가지고 있다. 또한 직립한 꽃대에 늘어짐이 적은 잎을 가져 전체적으로 안정적인 형태를 이루며 개화시기는 3월경으 로 만생종에 속한다. 한편 고온에 의해 화색이 탁해질 수 있 으나, 전반적으로 재배 관리가 용이한 편이다.

The periodic occurrence of biological population is affected by several biological and environmental factors and ancient literature survey offers insight into ecological process related to the cyclicity. The periodic occurrence of a Lepidopteran species, the pine caterpillar (Dendrolimus spectabilis), was estimated based on ancient literature survey. The pine caterpillar was one of the most injurious defoliators of pine trees in northeast Asia, especially Korea during 1960s and 1970s. Outbreaks of this species have long history in Korea. Since about 900 years ago, damages of pine forest by this species and its control were recorded both in History of Corea dynasty which cover 475 years (918-1392) of the history of the Corea Dynasty and in the Annals of Joseon Dynasty (Joseon Wangjo Shillok) which cover 472 years (1392-1863) of the history of the Joseon Dynasty, respectively. At least over 20 and 30 occurrences of pine caterpillar were recorded during Corea dynasty and Joseon Dynasty, respectively. These results showed that the pine caterpillar had been one of the most severe forest pests during Corea and Joseon Dynasty. Our result showed that the ancient literature survey is useful to understand the long-term periodic occurrence of the pine caterpillar.

In the current study, a total of 102 common Todarodes pacificus squid caught in the East Sea were investigated for parasitological research. The results revealed that 33 (32.35%) out of 102 squid were infected by Nybelinia surmenicola, the mean intensity was 5.58 parasites per squid, and the maximum abundance was 11. Morphological analysis using a field emission scanning electron microscope showed the characteristic features of N. surmenicola. Molecular identification based on the 28S rRNA gene confirmed the isolated parasite as N. surmenicola, while phylogenetic analysis revealed that N. surmenicola isolated in this study was clustered with N. surmenicola isolated from Japan. This is the first report of phylogenetic characterization of N. surmenicola isolated from Korea.

경주 방사성폐기물 처분시설은 향후 80만 포장물을 처분할 계획이며 다양한 처분방식 및 관리형태를 가진 복합계가 될 것 이다. 본 논문에서는 전체부지 처분용량(80만 포장물) 처분시설의 단계별 개발에 따른 영향을 평가하기 위하여 처분시설 종 합개발계획(안)에 따른 예비안전성평가를 수행하였다. 각 시나리오에 대한 안전성평가결과 처분시설의 성능목표치를 만족 하였다. 다만, 전체처분시설의 안전성 평가결과에 중준위 방사성폐기물로 인하여 1단계 동굴 처분시설이 가장 크게 영향을 미치므로 처분시설의 안전성 향상을 위하여 처분방사능량제한 설정 등 관리방안이 필요하다. Safety Case 단계별 구축을 통 하여 중·저준위 방사성폐기물 처분시설 종합개발 과정에서 인지된 불확실성을 저감하여 안전성을 증진 시킬 수 있을 것으 로 판단된다.

The squid Todarodes pacificus is a commercially important fishery species in East Asia. As East Asians consume raw or lightly cooked squids, there has been growing concern about parasitic infections associated with squid consumption. In the current study, five squids caught in the East Sea were sampled for parasitological research from the biggest fishery market in Seoul, Republic of Korea. They were dissected and examined for parasites using a light microscope. Proteocephalus sp. was isolated and identified using field emission scanning electron microscopy, PCR, and sequencing. Given that Proteocephalus spp. can be affected by water temperature and geographical characteristics, further research on Proteocephalus spp. with respect to changes in water temperature in the East Sea is important.

Oxalic acid has a nematicidal activity against the root-knot nematode Meloidogyne incognita. High producer of oxalic acid was isolated, and then named as Aspergillus niger F22. Oxalic acid production was investigated under various temperatures from 20 – 33oC and rotational speeds in 5 L jar fermenters. Yield of oxalic acid increased with decreasing temperature. The highest yield was obtained at 23oC, showing the yield of oxalic acid of 8.7 g/L, whereas oxalic acid production was least at 33oC. At 20oC, the yield was lower than that of 23oC. At a rotational speed of 300 rpm, serious oxygen depletion was present from 48 - 72 h, resulting in low productivity of 26.2 mg /L·h. When a rotational speed was set at 600 rpm, dissolved oxygen tension was over 40% and oxalic acid production increased up to approximately 55%. Viscosity during the culture differed with temperatures. Viscosity increased with the increment of temperatures. When A. niger F22 was cultured at 23oC, viscosity was 810 cP, which was favorable for oxalic acid production.