A procedure for minimizing the environmental burden and maximizing the efficiency of storage sites used for the final disposal of spent fuel has been proposed. In this procedure, fission products (highly mobile and producing heat) are collected, and uranium and TRU-RE (transuranium-rare earth) oxide are independently stored. The possibility and applicability of radiation measurement for monitoring the nuclear materials effectively throughout the process has been simulated and evaluated. For the simulation, the properties of the chemical processes were analyzed, the major radiation emitters were determined, and the production of nuclear materials by chemical reactions were evaluated. In each process, the content of nuclear material was changed by up to 20% to represent abnormal conditions. The results showed that the plutonium peak was matched with the change in the TRU content and the measured signal was changed linearly with respect to the content change of the plutonium. From the neutron measurement, a linear response of the TRU content variation was obtained. In addition, a logic diagram was developed for the nuclear monitoring. The integration of radiation detections is recommended for monitoring the process effectively and efficiently.
Polyploidization, or genome doubling, has a significant impact on plant speciation and adaptation, and it is commonly used in agriculture to improve crop traits. In this study, we investigated the induction of polyploidy in three wild Allium species native to Korea: A. senescens and A. spirale Willd. and A. taquetii, using colchicine treatments tailored to meet specific experimental requirements. By avoiding tissue culture methods, we developed a more accessible, cost-effective, and scalable approach to polyploidization. Our research demonstrated that polyploid Allium plants exhibit distinct phenotypic changes, such as reduced growth rates and increased stomatal size. Flow cytometry and chromosome counting confirmed the successful induction of polyploidy, with clear peaks indicating double DNA content and stable chromosome numbers in polyploid plants. The presence of B chromosomes in A. spirale Willd. following polyploidization suggest interesting genetic dynamics. Despite the initial growth lags, polyploid plants may offer enhanced photosynthetic efficiency and resilience under optimal conditions. This study highlights the potential of polyploidization to improve ornamental traits in Allium species, thereby contributing to the diversification and sustainability of ornamental plant offerings. Future research should focus on the long-term performance and ecological adaptability of polyploid Allium species to fully harness their horticultural potential.
Mocis frugalis (Fabricius, 1775), the sugarcane looper, was collected in Byeonsanbando National Park in South Korea for the first time. This species is known as a major crop pest, especially to sugarcane at tropical and subtropical regions. Due to climate change and the subtropicalization of the southern part of the Korean Peninsula, some tropical and subtropical crops are cultivated in Korea, including sugarcane. Besides, Oryza sativa L. and Zea mays L., which of main crops in Korea, are known as host plants of M. frugalis in the Oriental region. Even if unclear of domestic settlement, precision monitoring will be necessary.
The genus Trichophysetis is one of the taxa that has recently undergone frequent changes in its taxonomic position. Only four species have been recorded in Korea, including synonymized Hendecasis species. Recent studies on the taxonomic classification of Trichophysetis have not addressed any species inhabiting Korea. Therefore, it is necessary to conduct a renewed morphological analysis of Korean species. In this study, we compare and analyze four Korean Trichophysetis species with one newly recorded species.
The genus Trichophysetis is one of the taxa that has recently undergone frequent changes in its taxonomic position. Only four species have been recorded in Korea, including synonymized Hendecasis species. Recent studies on the taxonomic classification of Trichophysetis have not addressed any species inhabiting Korea. Therefore, it is necessary to conduct a renewed morphological analysis of Korean species. In this study, we compare and analyze four Korean Trichophysetis species with one newly recorded species.
실감형 콘텐츠 관련 연구가 활발히 진행되고 있다. AR을 중심으로 한 실감형 콘텐츠의 발전은 스마트 폰을 이용하여 실세계에 3D 가상 콘텐츠를 추가하는 것을 넘어, 대형 건축물에 Projection Mapping을 하는 Media Facade 콘텐츠로 발전되었다. 최근 Projection Mapping을 이용한 Media Facade를 활용한 광고 콘텐츠의 수요가 증가하면서 Projection Mapping콘텐츠에 대한 교육과 시스템개발이 요구 되고 있다. Projection Mapping을 처음 배우는 교육생의 경우, 투사할 사물 및 건축물을 만드는 것부터 큰 어려움으로 작용된다. 사물 및 건축물을 구축하기 위해서는 그만한 자원과 재원이 요구되며, 한번 만들고 나면 다시 자원 을 활용하여 바꾸기 쉽지 않다. 본 논문에서는 Projection Mapping 교육을 위한 Unity 3D Engine 기반 Projection Mapping Simulation을 제안한다. 제안된 Projection Mapping Simulation는 Unity 3D Engine을 기반하였기 때문에 무료로 교육생들이 사용이 가능하며, 다양한 3D Object File를 활용하여 사물 및 건축물을 나타내고 조작할 수 있다. 또한, Projection Mapping에 쓰이는 영상을 Video 뿐 아니라, 실시간 3D Rendering으로 사용할 수도 있다. 본 논문에서 제안한 Projection Mapping Simulation는 교육생들에게 공간과 사 물 및 건축물의 이해를 돋기 위한 실험의 장이 될 것이며, Projection Mapping 콘텐츠 연구 자들에게는 여러 Projection Mapping 기법을 실험 및 연구할 수 있는 장이 되길 희망한다.
This study explores the perceptions of Chinese engineering-major students towards their English learning experience after taking a mandatory English composition course in an EMI college. The investigation centers on first-year students’ perceptions of transitioning to EMI, with a focus on how the composition course has assisted students’ transition as a primary language support. Data were collected through a metaphor elicitation technique in which students expressed their perceptions of English learning, complemented by a thematic analysis of 86 reflection essays on the composition class. An analysis of the 334 metaphors identified students’ enhanced confidence in English, the importance of the English-using environment, positive views of learning communities, and increased agency in the learning process. It also revealed that many students were stressed and unaware of learning strategies, therefore suggesting institutional-level language support. One implication is to promote the culture of the learning community. The findings can be particularly useful for programs that are implementing language support for non-English major students.
In South Korea, the replacement of steam generators began with Kori Unit 1 in 1995, and to date, 20 steam generators have been replaced and are currently stored in intermediate storage facilities. In the future, additional decommissioned steam generators may arise due to measures like the extension of the lifespan of nuclear power plants. In Korea, technological development for dismantling steam generators is underway, and there is no track record of actual dismantling. Although the replaced decommissioned steam generators are stored in intermediate facilities, for site recycling purposes, steam generators, which have relatively lower radiation doses compared to reactor heads and other primary equipment, should be prioritized for dismantling. While there are various specifications for steam generators, those dismantled and stored domestically are of the Recirculation Type. They can be classified into three types: the Westinghouse type WH-51 used in Kori Unit 1, the Fra-51B used in Han-ul Units 1 and 2, and the OPR-1000 used in Han-ul Units 3 and 4. The quantity of U-Tubes varies depending on the specification, but the radiation is concentrated in the primary side components, the U-Tube and Chamber. Since the parts related to the secondary side are not contaminated, they can be disposed of independently after classification. To dismantle a steam generator, it is of utmost importance to first create a scenario regarding where and how the dismantling will take place. Through the analysis of the advantages and disadvantages of each scenario, the optimal timing, location, and cutting method for dismantling should be researched. Furthermore, based on those findings, the best scenario should be derived through an analysis of worker radiation exposure and dismantling costs. To achieve this, a 3D simulation software developed by Cyclelife Digital Solutions under the French EDF was utilized to conduct simulations based on different dismantling schedules and methods. As a result, the optimal scenario for dismantling the steam generator was derived.
Derived Concentration Guideline Levels (DCGLs), which represent the residual radioactivity concentration limits, serve as the pivotal criteria for decontamination during decommissioning of nuclear power plants and are essential for license termination. The analysis of radionuclides in various media to check site-specific and radionuclide-specific DCGLs is a resource-intensive and time-consuming processes, and there are some radionuclides that are hard to analyze. In the decommissioning of the Rancho Seco nuclear power plant in the United States, a conservative approach was adopted. Potentially highly contaminated areas on the site were identified by collecting and analyzing soil samples, and radionuclides exceeding the Minimum Detectable Concentration (MDC) were selected as the potential Radionuclide of Concern (ROC), and surrogate DCGLs for hard-to-detect radionuclides were applied to soil samples. For soil samples in the Rancho Seco nuclear power plant, Cs-137 contributed more than 90% of the total radioactivity. DCGLs of the ROC were obtained using the scaling factors through analysis of Cs- 137 for a large amount of soil samples. In Korea, the scaling factor methodology has not been applied to the decommissioning of commercial nuclear power plants. An initial investigation was undertaken to assess the viability of implementing Surrogate Derived Concentration Guideline Levels (DCGLs) in the dismantling of Kori Unit 1, drawing insights from the U.S. nuclear power plant decommissioning experiences. To do this approach, the concentration ratio of radionuclides of interest to key radionuclide in contaminated soil should be known and consistent. But related information is not available at this time. So Surrogate DCGL for representative C-14, Fe-55, Ni-59, Ni-63, and Sr-90 was obtained using the scaling factors applied to radioactive waste data, specifically Decontaminated Aqueous Waste (DAW) and Spent Resin. In order to develop a reliable surrogate DCGLs the Kori Unit 1 site, it is important to analyze the radionuclides in the soil for the Kori Unit 1 decommissioning site to obtain consistent concentration ratio of the radionuclides of concern to the key radionuclides. When a the suitable DCGL is developed, it can be used for FSS planning and prior decision-making ensuring the safe and effective decommissioning of Kori Unit 1 and similar nuclear power plants.
Nuclear safety, security, and safeguards (nuclear 3S) are essential components for establishing robust nuclear environments. Nuclear safety is to protect public and environments from radioactive contamination, which can be caused in accidents. Nuclear security is to protect nuclear facilities from terrorism or sabotage, which related to physical a ttacks or insider threats. And nuclear safeguards is to protect nuclear materials from extortion by a state with a purpose of weaponizing activities. When a new nuclear facility is introduced, it is possible to save abundant amount of resources by considering nuclear 3S in an early stage (design phases). Initially, the international atomic energy agency (IAEA) recommended safeguards-by-design (SBD) approach. The concept of SBD gradually expands to nuclear 3S-by-design (3SBD). Though there are differences in purpose and target subject, each nuclear ‘S’ is closely related with others. When introducing a certain technology or equipment in order to enhance one ‘S’, another ‘S’ also get affected. The effect can be synergies or conflicts. For instance, confidential information in nuclear security is required for a safeguards activity. On the contrary, inspection equipment for safeguards can be used for security. Pyroprocessing is a technology for managing used nuclear fuels. As pyroprocessing is a backend fuel cycle technology, a sensitive nuclear technology, safeguards has taken a large portion of nuclear 3S research in an effort to achieve international credibility and nuclear transparency. As mentioned, there are both synergies and conflicts in integrating nuclear 3S. In this study, we investigate potential challenges in applying nuclear 3S integration to pyroprocessing by addressing synergies and conflicts. This approach will suggest required supplementary methods to build the reliable pyroprocessing environment.
아메리카동애등에 유충은 유기성폐기물을 먹이원으로 하며 그 분해산물인 동애등에분은 비료원료로 활용 가능하다. 그러나 농가에서 나오는 분변토는 염분함량이 높아 단독으로 사용하면 토양에 염류집적의 우려가 있다. 이에 산업곤충인 동애등에 분변토의 염분을 낮춰 퇴비로 활용하고자 옥수수(미백2호)에 5처리(무처리, 동애등에분, 동애등에분:흰점박이꽃무지분(2:8), 동애등에분:퇴비(2:8), 퇴비)로 비료를시용하였다. 옥수수 생 육은 초장, 간장, 웅수장, 착수고를 조사하였고 종실은 이삭중, 이삭장, 착립이삭장, 이삭폭 등을 조사하였다. 처리구별 옥수수 수량(kg/10a)은 무처리구 702.8kg, 동애등에분처리구 835.6kg. 동애등에분:흰점박이꽃무지분 (2:8) 처리구 723.7kg, 동애등에분:퇴비(2:8) 처리구 862.3kg, 퇴비 처리구 803.7kg으로 조사되었다. 동애등에 분변 토를 시판퇴비와 혼합하여 퇴비로 활용하면 옥수수 생산을 증진시키는데 효과적이나 장기적인 실험을 통해 토양과 작물에 미치는 영향을 모니터링해야 될 것으로 판단된다.
아메리카동애등에(H. illucens)는 음식물 폐기물 등 유기성 폐자원을 효율적으로 처리할 수 있는 능력을 가지 고 있어 전세계적으로 주목받고 있는 환경정화 곤충이다. 하지만 유기성 폐자원을 처리 시 가장 큰 문제는 아메리 카동애등에가 먹이인 유기성 폐자원을 소화시킬 때 발생되는 악취이다. 국내에서 현재 아메리카동애등에를 사육하고 있는 농가는 223호로 조사되고 있지만 이중 악취발생 저감장치 등을 설치한 농가는 10%가 안되는 것으 로 생각된다. 따라서 국내에서 동애등에 먹이로 가장 많이 사용되는 습식사료를 먹이로 사용하였을 때 농가 사육 장 안에서 발생되는 복합악취와 지정악취 22종에 대하여 분석하였다. 그 결과, 복합악취는 249배였으며, 지정악 취는 22종 중 7종(암모니아, 메틸메르캅탄, 트라이메틸아민, 아세트알데하이드, 프로피온알데하이드, 뷰틸알 데하이드, i-발레르알데하이드)가 검출되었다. 이중 가장 높은 농도를 나타낸 악취물질은 암모니아로 98.4ppm 이 분석되었다. 또한, 아메리카동애등에를 사육 시 가장 많이 발생되는 암모니아의 발생시기는 사육초기인 1~4 령보다 5령 이후 전생육기 중의 대부분을 발생시키는 것으로 조사되었다. 이러한 결과는 암모니아 저감을 위한 적정시기를 설정하는데 도움이 될 것으로 생각된다.