Nuclear power plants use ion exchange resins to purify liquid radioactive waste generated while operating nuclear power plants. In the case of PHWR, ion exchange resins are used in heavy water and dehydration systems, liquid waste treatment systems, and heavy water washing systems, and the used ion exchange resins are stored in waste resin storage tanks. The C-14 radioactivity concentration in the waste resin currently stored at the Wolseong Nuclear Power Plant is 4.6×106 Bq/g, exceeding the low-level limit, and if all is disposed of, it is 1.48×1015 Bq, exceeding the total limit of 3.04×1014 Bq of C-14 in the first stage disposal facility. Therefore, disposal is not possible at domestic low/medium-level disposal facilities. In addition, since the heavy water reactor waste resin mixture is stored at a ratio of about 20% activated carbon and zeolite mixture and about 80% waste resin, mixture extraction and separation technology and C-14 desorption and adsorption technology are required. Accordingly, research and development has been conducted domestically on methods to treat heavy water waste resin, but the waste resin mixture separation method is complex and inefficient, and there are limitations in applying it to the field due to the scale of the equipment being large compared to the field work space. Therefore, we would like to introduce a resin treatment technology that complements the problems of previous research. Previously, the waste resin mixture was extracted from the upper manhole and inspection hole of the storage tank, but in order to improve limitations such as worker safety, cost, and increased work time, the SRHS, which was planned at the time of nuclear power plant design, is utilized. In addition, by capturing high-purity 14CO2 in a liquid state in a high-pressure container, it ensures safety for long-term storage and is easy to handle when necessary, maximizing management efficiency. In addition, the modularization of the waste resin separation and withdrawal process from the storage tank, C-14 desorption and monitoring process, high-concentration 14CO2 capture and storage process, and 14CO2 adsorption process enables separation of each process, making it applicable to narrow work spaces. When this technology is used to treat waste resin mixtures in PHWR, it is expected to demonstrate its value as customized, high-efficiency equipment that can secure field applicability and safety and reflect the diverse needs of consumers according to changes in the working environment.

Non-destructive estimation of leaf area is a more efficient and convenient method than leaf excision. Thus, several models predicting leaf area have been developed for various horticultural crops. However, there are limited studies on estimating the leaf area of strawberry plants. In this study, we predicted the leaf areas via nonlinear regression analysis using the leaf lengths and widths of three-compound leaves in five domestic strawberry cultivars (‘Arihyang’, ‘Jukhyang’, ‘Keumsil’, ‘Maehyang’, and ‘Seollhyang’). The coefficient of determination (R2) between the actual and estimated leaf areas varied from 0.923 to 0.973. The R2 value varied for each cultivar; thus, leaf area estimation models must be developed for each cultivar. The leaf areas of the three cultivars ‘Jukhyang’, ‘Seolhyang’, and ‘Maehyang’ could be non-destructively predicted using the model developed in this study, as they had R2 values over 0.96. The cultivars ‘Arihyang’ and ‘Geumsil’ had slightly low R2 values, 0.938 and 0.923, respectively. The leaf area estimation model for each cultivar was coded in Python and is provided in this manuscript. The estimation models developed in this study could be used extensively in other strawberry-related studies.

프리지아 ‘Sunny Gold’는 농촌진흥청 국립원예특작과학원 에서 2010년 노랑색 반겹꽃 프리지아 육성계통 ‘036010’을 모본으로 진노란색 홑꽃 ‘Golden Flame’을 부본으로 교배하여 획득한 종자로부터 2011년 진노란색 겹꽃의 향기가 강한 프리지아 계통을 선발하여 품종화 하였다. 2011년부터 2016년까지 개화 생육특성검을 수행하였으며 핵심수요자의 기호도 평가를 통해 선발되어 2017년 ‘Sunny Gold’ 로 명명되었다. ‘Sunny Gold’는 RHS color chart YO17B의 노란색 겹꽃 프리지아 품종으로 화폭은 6.7cm로 대조품종 ‘Golden Flame’ 6.1cm에 비해 크고, 분지수는 6.5로 다수확성 품종이다. 초장이 101.9cm로 초세가 강하다. ‘Sunny Gold’의 소화수 및 소화장은 각각 13.0개, 9.3cm이며 개화소요일수는 137.7일이다. 이 품종의 절화수명은 약 9일이며 자구번식력은 5.3배로 대조 품종 ‘Golden Flame’ 4.3배에 비해 우수하다. 전자코를 이용한 PCA분석결과 PC1과 PC2는 각각 99.3%와 0.6%로 전체 변이량의 99.9%를 반영하고 있다. Rader plot 분석결과 총 6개 센서에서 모두 ‘Sunny Gold’의 센서값이 향기가 강한 상용품종 ‘Yvonne’의 값에 비해 높게 나타나 ‘Sunny Gold’의 향기가 더 강한 것으로 나타났다.

Amniotic membrane stem cells are considered as a good alternative to embryonic stem cells, but their use in clinical studies is still not common. Here, exosomes from canine amniotic membrane mesenchymal stem cells (cAmMSCexo) were used for dog sperm cryopreservation. Upon cryopreserved straws using cryoprotectant containing 0, 0.5, 1, or 2 μg/mL of cAmMSC-exo were thawed, motility and membrane integrity were analyzed. However, results showed no significant differences between the groups. We concluded that cAmMSC-exo with lower than 2 µg/mL have no effects on sperm cryopreservation, and further studies to get higher concentrations of cAmMSC-exo should be conducted for clinical application.

This study focused on challenges faced by early childhood English teachers in Korea against the backdrop of the local rise of English education for young learners. A mixed-method was used to collect data, including open-ended survey questionnaires and interviews. Six teachers from 250 early childhood English teachers were selected for this study based on the length of teaching experience. A number of challenges emerged from the analysis of the survey, including classroom management, mixed-level class, motivation, teaching methodology, parents involvement, restrained English education in the context of Korea, the teacher’s level of English, lack of assessment and materials which fit early childhood language learners, and balancing between interest and learning. Nine distinct themes were found based on calculated frequency. They were cross-tabulated by two groups of teachers depending on whether teachers had less or more than three years of teaching experience. Results showed challenges and difficulties faced by teachers with lengthy teaching experience. Findings of this study suggest a way to build teacher education programs to support the challenges identified by teachers.

Photosynthetic characteristics and growth responses of Phalaenopsis Queen Beer ‘Mantefon’ orchid were determined in plants exposed to variable carbon dioxide (CO2) concentrations at 2-, 24-, and 36-weeks age (i.e., corresponding to juvenile, young, and mature vegetative growth stages, respectively). Plants were grown at 400 (control), 800, or 1,600 μmol･mol-1 CO2 for 6 hours during the nighttime for 32 weeks. Phalaenopsis ‘Mantefon’ in 2- and 24-week-old plants grown at 1,600 μmol･mol-1 CO2 had increased leaf number and net CO2 uptake compared with the plants grown at 400 μmol･mol-1 CO2. In 36-week-old of Phalaenopsis ‘Mantefon’, leaf number was significantly greater in plant grown at 800 and 1,600 μmol･mol-1 conditions compared with plants grown at 400 μmol･mol-1 CO2. Leaves that emerged after the start of the CO2 treatment were initially longer in the plants grown at 1,600 μmol･mol-1 CO2 than at 400 μmol·mol-1 C O2, but the final leaf length was shortest in the plants grown at 1,600 μmol･mol-1 CO2 condition. Plants showed crassulancean acid metabolism characteristic of nighttime CO2 uptake regardless plant growth stages. We found that growers may be able to promote leaf growth with increasing leaf number and reducing time to leaf initiation in the 36-week-old (i.e., mature stage) plants with 800 – 1,600 μmol·mol-1 CO2 and 2- and 24-week-old (i.e., juvenile and young stages) plants with 1,600 μmol·mol-1 C O2 for Phalaenopsis ‘Mantefon’.